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Sample records for radiation induced production

  1. Radiation-induced tritium labelling and product analysis

    Energy Technology Data Exchange (ETDEWEB)

    Peng, C.T. (California Univ., San Francisco, CA (United States). Dept. of Pharmaceutical Chemistry)

    1993-05-01

    By-products formed in radiation-induced tritium labelling are identified by co-chromatography with authentic samples or by structure prediction using a quantitative structure-retention index relationship. The by-products, formed from labelling of steroids, polynuclear aromatic hydrocarbons, 7-membered heterocyclic ring structures, 1,4-benzodiazepines, 1-haloalkanes, etc. with activated tritium and adsorbed tritium, are shown to be specifically labelled and anticipated products from known chemical reactions. From analyses of the by-products, one can conclude that the hydrogen abstraction by tritium atoms and the substitution by tritium ions are the mechanisms of labelling. Classification of the tritium labelling methods, on the basis of the type of tritium reagent, clearly shows the active role played by tritium atoms and ions in radiation-induced methods. (author).

  2. Radiation-induced volatile hydrocarbon production in platelets

    International Nuclear Information System (INIS)

    Radha, E.; Vaishnav, Y.N.; Kumar, K.S.; Weiss, J.F.

    1989-01-01

    Generation of volatile hydrocarbons (ethane, pentane) as a measure of lipid peroxidation was followed in preparations from platelet-rich plasma irradiated in vitro. The hydrocarbons in the headspace of sealed vials containing irradiated and nonirradiated washed platelets, platelet-rich plasma, or platelet-poor plasma increased with time. The major hydrocarbon, pentane, increased linearly and significantly with increasing log radiation dose, suggesting that reactive oxygen species induced by ionizing radiation result in lipid peroxidation. Measurements of lipid peroxidation products may give an indication of suboptimal quality of stored and/or irradiated platelets

  3. Formation and properties of radiation-induced defects and radiolysis products in lithium orthosilicate

    Energy Technology Data Exchange (ETDEWEB)

    Tiliks, J.E.; Kizane, G.K.; Supe, A.A.; Abramenkovs, A.A.; Tiliks, J.J. (Latvian Univ., Riga (Latvia)); Vasiljev, V.G. (Acad. A.A. Bochvar Inst. of Inorganic Materials, Moscow (USSR))

    1991-12-01

    Formation and properties of radiation-induced defects and radiolysis products in polycrystalline powders and ceramic pellets of Li{sub 4}SiO{sub 4} were studied under the effect of various types of ionizing irradiation ({gamma} quants, accelerated electrons, reactor irradiation), humidity, temperature, impurities in the samples, etc. The content of radiation defects and radiolysis products poorly depends on irradiation type, dose rate, admixture elements. The concentration of defects highly depends on the temperature of irradiation, humidity, granural size. Empirical dependence of radiolysis degree {alpha} on the dose was found: {alpha}=5x10{sup -2}xD{sup 0.5} for {gamma} and electron irradiation (T{sub rad}=300-350 K) and {alpha}=5x10{sup -3}xD{sup 0.5} for reactor radiation (T{sub rad}=700-800 K); {alpha} - matrix dissociation degree (in %); D - dose (in MGy). Colloidal lithium and silicon, lithium and silicon oxides, and O{sub 2} are the final products of radiolysis. Radiation-induced defects change tritium thermo-extraction parameters, deteriorate mechanical, thermo-physical and electric properties of ceramics. (orig.).

  4. Carboplatin enhances the production and persistence of radiation-induced DNA single-strand breaks

    International Nuclear Information System (INIS)

    Yang, L.; Douple, E.B.; O'Hara, J.A.; Wang, H.J.

    1995-01-01

    Fluorometric analysis of DNA unwinding and alkaline elution were used to investigate the production and persistence of DNA single-strand breaks (SSBs) in Chinese hamster V79 and xrs-5 cells treated with the chemotherapeutic agent carboplatin in combination with radiation. Carboplatin was administered to cells before irradiation in hypoxic conditions, or the drug was added immediately after irradiation during the postirradiation recovery period in air. The results of DNA unwinding studies suggest that carboplatin enhances the production of radiation-induced SSBs in hypoxic V79 cells and xrs-5 cells by a factor of 1.86 and 1.83, respectively, when combined with radiation compared to the SSBs produced by irradiation alone. Carboplatin alone did not produce a measureable number of SSBs. Alkaline elution profiles also indicated that the rate of elution of SSBs was higher in cells treated with the carboplatin is present after irradiation and during the postirradiation recovery period, the rejoining of radiation-induced SSBs by a factor of 1.46 in V79 cells with 20 Gy irradiation and by a factor of 2.02 in xrs-5 cells with 20 Gy irradiation. When carboplatin is present after irradiation and during the postirradiation recovery period, the rejoining of radiation-induced SSBs is inhibited during this postirradiation incubation period (radiopotentiation) with a relative inhibition factor at 1 h postirradiation of 1.25 in V79 cells and 1.15 in xrs-5 cells. An increased production and persistence of SSBs resulting from the interaction of carboplatin with radiation may be an important step in the mechanism responsible for the potentiated cell killing previously from studies in animal tumors and in cultured cells. 31 refs., 7 figs

  5. Interaction of alpha radiation with thermally-induced defects in silicon

    International Nuclear Information System (INIS)

    Ali, Akbar; Majid, Abdul

    2008-01-01

    The interaction of radiation-induced defects created by energetic alpha particles and thermally-induced defects in silicon has been studied using a Deep Level Transient Spectroscopy (DLTS) technique. Two thermally-induced defects at energy positions E c -0.48 eV and E c -0.25 eV and three radiation-induced defects E2, E3 and E5 have been observed. The concentration of both of the thermally-induced defects has been observed to increase on irradiation. It has been noted that production rates of the radiation-induced defects are suppressed in the presence of thermally-induced defects. A significant difference in annealing characteristics of thermally-induced defects in the presence of radiation-induced defects has been observed compared to the characteristics measured in pre-irradiated samples

  6. Generation of volatile hydrocarbons as a measure of radiation-induced lipid peroxidation in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Dobbs, C R; Kumar, K S; Weiss, J F; Catravas, G N [Armed Forces Radiobiology Research Inst., Bethesda, MD (USA)

    1981-04-01

    Using gas chromatography techniques, pentane production from microsomes could be detected at gamma radiation doses as low as 50 Gy, but definite increases were observed only with the addition of the peroxidation promoter ADP-Fe. There was a small but linear increase in pentane production, and presumably lipid peroxidation, when nonirradiated microsomes alone were incubated. The addition of ADP-Fe induced a further production of pentane which was linear with incubation time. Radiation alone (700 and 2000 Gy) also induced pentane production, but the highest levels were observed with the combination of ADP-Fe and radiation. In microsomes irradiated with 700 Gy, the rate of pentane production was greatest during the first 100 min post-irradiation. In comparing radiation-induced pentane generation to the enzymatic-induced system, it was seen that pentane production was much greater in the latter system.

  7. Radiation-induced genomic instability and bystander effects: related inflammatory-type responses to radiation-induced stress and injury? A review.

    Science.gov (United States)

    Lorimore, S A; Wright, E G

    2003-01-01

    To review studies of radiation responses in the haemopoietic system in the context of radiation-induced genomic instability, bystander effects and inflammatory-type processes. There is considerable evidence that cells that themselves are not exposed to ionizing radiation but are the progeny of cells irradiated many cell divisions previously may express a high frequency of gene mutations, chromosomal aberrations and cell death. These effects are collectively known as radiation-induced genomic instability. A second untargeted effect results in non-irradiated cells exhibiting responses typically associated with direct radiation exposure but occurs as a consequence of contact with irradiated cells or by receiving soluble signals from irradiated cells. These effects are collectively known as radiation-induced bystander effects. Reported effects include increases or decreases in damage-inducible and stress-related proteins; increases or decreases in reactive oxygen species, cell death or cell proliferation, and induction of mutations and chromosome aberrations. This array of responses is reminiscent of effects mediated by cytokines and other similar regulatory factors that may involve, but do not necessarily require, gap junction-mediated transfer, have multiple inducers and a variety of context-dependent consequences in different cell systems. That chromosomal instability in haemopoietic cells can be induced by an indirect bystander-type mechanism both in vitro and in vivo provides a potential link between these two untargeted effects and there are radiation responses in vivo consistent with the microenvironment contributing secondary cell damage as a consequence of an inflammatory-type response to radiation-induced injury. Intercellular signalling, production of cytokines and free radicals are features of inflammatory responses that have the potential for both bystander-mediated and persisting damage as well as for conferring a predisposition to malignancy. The

  8. Radiation-induced apoptosis

    International Nuclear Information System (INIS)

    Ohyama, Harumi

    1995-01-01

    Apoptosis is an active process of gene-directed cellular self-destruction that can be induced in many cell types via numerous physiological and pathological stimuli. We found that interphasedeath of thymocytes is a typical apoptosis showing the characteristic features of apoptosis including cell shrinkage, chromatin condensation and DNA degradation. Moderate dose of radiation induces extensive apoptosis in rapidly proliferating cell population such as the epithelium of intestinal crypt. Recent reports indicate that the ultimate form of radiation-induced mitotic death in several cells is also apoptosis. One of the hallmarks of apoptosis is the enzymatic internucleosomal degradation of chromatin DNA. We identified an endonuclease responsible for the radiation-induced DNA degradation in rat thymocytes. The death-sparing effects of interrupting RNA and protein synthesis suggested a cell genetic program for apoptosis. Apoptosis of thymocytes initiated by DNA damage, such as radiation and radio mimetic substance, absolutely requires the protein of p53 cancer suppresser gene. The cell death induced by glucocorticoid, or aging, has no such requirement. Expression of oncogene bcl-2 rescues cells from the apoptosis. Massive apoptosis in radiosensitive cells induced by higher dose radiation may be fatal. It is suggested that selective apoptotic elimination of cells would play an important role for protection against carcinogenesis and malformation through removal of cells with unrepaired radiation-induced DNA damages. Data to evaluate the significance of apoptosis in the radiation risk are still poor. Further research should be done in order to clarify the roles of the cell death on the acute and late effects of irradiation. (author)

  9. Characterization of radiation-induced products of thymidine 3'-monophosphate and thymidylyl (3'→5') thymidine by high-performance liquid chromatography and laser-desorption fourier-transform mass spectrometry

    International Nuclear Information System (INIS)

    Yoshida, H.; Hettich, R.L.

    1994-01-01

    High-performance liquid chromatography (HPLC) and laser-desorption Fourier-transform mass spectrometry (LD FTMS) have been applied for direct measurements of radiation-induced products of nucleic acid constituents containing thymidine. Laser desorption FTMS could be used for the direct detection (neither hydrolyzed nor derivatized) of X-ray-induced decomposition products of aqueous thymidine monophosphate. After these initial experiments, a variety of hydrogenated and hydroxylated thymine standards were acquired and examined by FTMS to assist in the identification of unknown radiation-induced decomposition products of thymine-containing nucleotides and dinucleotides. To extend these studies to dinucleotides, the radiation-induced products generated by the gamma radiolysis of thymidylyl (3'→5') thymidine (TpT) were isolated by reverse-phase HPLC and identified by LD FTMS. Thymine and thymidine 3'-monophosphate were observed as the major products in this case. Several of the minor products of the HPLC profile were pooled in a single fraction and characterized simultaneously by LD FTMS. The resulting mass spectra indicated the presence of hydroxy-5,6-dihydothymidine monophosphate, 5,6-dihydrothymidine monophosphate and thymidine monophosphate, thymine glycol, hydroxy-5,6-dihydrothymine, 5-hydroxy-methyl-uracil and 5,6-dihydrothymine. The combination of HPLC purification and LD FTMS structural characterization provides a useful tool for the direct measurement of radiation-induced products of nucleotides and dinucleotides. 28 refs., 6 figs., 2 tabs

  10. Cell cycle arrest induced by radiation

    International Nuclear Information System (INIS)

    Okaichi, Yasuo; Matsumoto, Hideki; Ohnishi, Takeo

    1994-01-01

    It is known that various chemical reactions, such as cell cycle arrest, DNA repair and cell killing, can occur within the cells when exposed to ionizing radiation and ultraviolet radiation. Thus protein dynamics involved in such chemical reactions has received considerable attention. In this article, cell cycle regulation is first discussed in terms of the G2/M-phase and the G1/S-phase. Then, radiation-induced cell cycle arrest is reviewed. Cell cycle regulation mechanism involved in the G2 arrest, which is well known to occur when exposed to radiation, has recently been investigated using yeasts. In addition, recent study has yielded a noticeable finding that the G1 arrest can occur with intracellular accumulation of p53 product following ionization radiation. p53 is also shown to play an extremely important role in both DNA repair and cell killing due to DNA damage. Studies on the role of genes in protein groups induced by radiation will hold promise for the elucidation of cell cycle mechanism. (N.K.) 57 refs

  11. Better flocculants by radiation induced polymerization

    International Nuclear Information System (INIS)

    Laizier, J.; Gaussens, G.

    1978-01-01

    The use of radiation induced polymerization should theoritically allow to prepare better flocculants. The testings of several products prepared by such a process shows that better properties are indeed obtained: better efficiencies, lower amounts needed, better overall properties [fr

  12. Radiation-Induced Differentiation in Human Lung Fibroblast

    International Nuclear Information System (INIS)

    Park, Sa-Rah; Ahn, Ji-Yeon; Han, Young-Soo; Shim, Jie-Young; Yun, Yeon-Sook; Song, Jie-Young

    2007-01-01

    One of the most common tumors in many countries is lung cancer and patients with lung cancer may take radiotherapy. Although radiotherapy may have its own advantages, it can also induce serious problems such as acute radiation pneumonitis and pulmonary fibrosis. Pulmonary fibrosis is characterized by excessive production of α-SMA and accumulation of extracellular matrix (ECM) such as collagen and fibronectin. There has been a great amount of research about fibrosis but the exact mechanism causing the reaction is not elucidated especially in radiation-induced fibrosis. Until now it has been known that several factors such as transforming growth factor (TGF-β), tumor necrosis factor (TNF), interleukin (IL)-1, IL-6, platelet-derived growth factor (PDGF) and fibroblast growth factor (FGF) are related to fibrosis. Among them TGF-β with Smad signaling is known to be the main stream and other signaling molecules such as MAPK, ERK and JNK (3) also participates in the process. In addition to those above factors, it is thought that more diverse and complicate mechanisms may involve in the radiationinduced fibrosis. Therefore, to investigate the underlying mechanisms in radiation induced fibrosis, first of all, we confirmed whether radiation induces trans differentiation in human normal lung fibroblasts. Here, we suggest that not only TGF-β but also radiation can induce trans differentiation in human lung fibroblast WI-38 and IMR-90

  13. Binding of radiation-induced phenylalanine radicals to DNA

    International Nuclear Information System (INIS)

    Schans, G.P. van der; Rijn, C.J.S. van; Bleichrodt, J.F.

    1975-11-01

    When an aqueous solution of double-stranded DNA of bacteriophage PM2 containing phenylalanine and saturated with N 2 O is irradiated with γ-rays, radiation-induced phenylalanine radicals are bound covalently. Under the conditions used about 25 phenylalanine molecules may be bound per lethal hit. Also for single-stranded PM2 DNA, most of the phenylalanine radicals bound are non-lethal. Evidence is presented that in double-stranded DNA an appreciable fraction of the single-strand breaks is induced by phenylalanine radicals. Radiation products of phenylalanine and the phenylalanine bound to the DNA decrease the sensitivity of the DNA to the induction of single-strand breaks. There are indications that the high efficiency of protection by radiation products of phenylalanine is due to their positive charge, which will result in a relatively high concentration of these compounds in the vicinity of the negatively charged DNA molecules

  14. The dominant allele Aft induces a shift from flavonol to anthocyanin production in response to UV-B radiation in tomato fruit.

    Science.gov (United States)

    Catola, Stefano; Castagna, Antonella; Santin, Marco; Calvenzani, Valentina; Petroni, Katia; Mazzucato, Andrea; Ranieri, Annamaria

    2017-08-01

    The introgression of the A ft allele into domesticated tomato induced a shift from flavonol to anthocyanin production in response to UV-B radiation, while the hp - 1 allele negatively influenced the response of flavonoid biosynthesis to UV-B. Introgression of the dominant allele Anthocyanin fruit (Aft) from Solanum chilense induces anthocyanin accumulation in the peel of tomato (Solanum lycopersicum L.) fruit. UV-B radiation can influence plant secondary metabolism regulating the expression of several genes, among which those involved in flavonoid biosynthesis. Here, we investigated whether post-harvest UV-B treatment could up-regulate flavonoid production in tomato fruits and whether the Aft allele could affect flavonoid biosynthesis under UV-B radiation. Mature green fruits of an anthocyanin-rich tomato mutant line (SA206) and of its wild-type reference, cv. Roma, were daily subjected to post-harvest UV-B treatment until full ripening. Up-regulation of CHS and CHI transcription by UV-B treatment induced flavonoid accumulation in the peel of cv. Roma. Conversely, UV-B decreased the total flavonoid content and CHS transcript levels in the SA206 peel. SA206 being a double mutant containing also hp-1 allele, we investigated also the behavior of hp-1 fruit. The decreased peel flavonoid accumulation and gene transcription in response to UV-B suggest that hp-1 allele is involved in the marked down-regulation of the flavonoid biosynthesis observed in SA206 fruit. Interestingly, in SA206, UV-B radiation promoted the synthesis of delphinidin, petunidin, and malvidin by increasing F3'5'H and DFR transcription, but it decreased rutin production, suggesting a switch from flavonols to anthocyanins. Finally, although UV-B radiation does not reach the inner fruit tissues, it down-regulated flavonoid biosynthesis in the flesh of both genotypes. This study provides, for the first time, evidence that the presence of the functional Aft allele, under UV-B radiation, redirects

  15. Radiation-induced valvular heart disease.

    Science.gov (United States)

    Gujral, Dorothy M; Lloyd, Guy; Bhattacharyya, Sanjeev

    2016-02-15

    Radiation to the mediastinum is a key component of treatment with curative intent for a range of cancers including Hodgkin's lymphoma and breast cancer. Exposure to radiation is associated with a risk of radiation-induced heart valve damage characterised by valve fibrosis and calcification. There is a latent interval of 10-20 years between radiation exposure and development of clinically significant heart valve disease. Risk is related to radiation dose received, interval from exposure and use of concomitant chemotherapy. Long-term outlook and the risk of valve surgery are related to the effects of radiation on mediastinal structures including pulmonary fibrosis and pericardial constriction. Dose prediction models to predict the risk of heart valve disease in the future and newer radiation techniques to reduce the radiation dose to the heart are being developed. Surveillance strategies for this cohort of cancer survivors at risk of developing significant heart valve complications are required. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  16. Enhancement of chemically induced reactive oxygen species production and DNA damage in human SH-SY5Y neuroblastoma cells by 872 MHz radiofrequency radiation

    Energy Technology Data Exchange (ETDEWEB)

    Luukkonen, Jukka [Department of Environmental Science, University of Kuopio, Bioteknia 2, P.O. Box 1627, FI-70211 Kuopio (Finland)], E-mail: Jukka.Luukkonen@uku.fi; Hakulinen, Pasi; Maeki-Paakkanen, Jorma [Department of Environmental Health, National Public Health Institute, P.O. Box 95, FI-70701 Kuopio (Finland); Juutilainen, Jukka; Naarala, Jonne [Department of Environmental Science, University of Kuopio, Bioteknia 2, P.O. Box 1627, FI-70211 Kuopio (Finland)

    2009-03-09

    The objective of the study was to investigate effects of 872 MHz radiofrequency (RF) radiation on intracellular reactive oxygen species (ROS) production and DNA damage at a relatively high SAR value (5 W/kg). The experiments also involved combined exposure to RF radiation and menadione, a chemical inducing intracellular ROS production and DNA damage. The production of ROS was measured using the fluorescent probe dichlorofluorescein and DNA damage was evaluated by the Comet assay. Human SH-SY5Y neuroblastoma cells were exposed to RF radiation for 1 h with or without menadione. Control cultures were sham exposed. Both continuous waves (CW) and a pulsed signal similar to that used in global system for mobile communications (GSM) mobile phones were used. Exposure to the CW RF radiation increased DNA breakage (p < 0.01) in comparison to the cells exposed only to menadione. Comparison of the same groups also showed that ROS level was higher in cells exposed to CW RF radiation at 30 and 60 min after the end of exposure (p < 0.05 and p < 0.01, respectively). No effects of the GSM signal were seen on either ROS production or DNA damage. The results of the present study suggest that 872 MHz CW RF radiation at 5 W/kg might enhance chemically induced ROS production and thus cause secondary DNA damage. However, there is no known mechanism that would explain such effects from CW RF radiation but not from GSM modulated RF radiation at identical SAR.

  17. Enhancement of chemically induced reactive oxygen species production and DNA damage in human SH-SY5Y neuroblastoma cells by 872 MHz radiofrequency radiation

    International Nuclear Information System (INIS)

    Luukkonen, Jukka; Hakulinen, Pasi; Maeki-Paakkanen, Jorma; Juutilainen, Jukka; Naarala, Jonne

    2009-01-01

    The objective of the study was to investigate effects of 872 MHz radiofrequency (RF) radiation on intracellular reactive oxygen species (ROS) production and DNA damage at a relatively high SAR value (5 W/kg). The experiments also involved combined exposure to RF radiation and menadione, a chemical inducing intracellular ROS production and DNA damage. The production of ROS was measured using the fluorescent probe dichlorofluorescein and DNA damage was evaluated by the Comet assay. Human SH-SY5Y neuroblastoma cells were exposed to RF radiation for 1 h with or without menadione. Control cultures were sham exposed. Both continuous waves (CW) and a pulsed signal similar to that used in global system for mobile communications (GSM) mobile phones were used. Exposure to the CW RF radiation increased DNA breakage (p < 0.01) in comparison to the cells exposed only to menadione. Comparison of the same groups also showed that ROS level was higher in cells exposed to CW RF radiation at 30 and 60 min after the end of exposure (p < 0.05 and p < 0.01, respectively). No effects of the GSM signal were seen on either ROS production or DNA damage. The results of the present study suggest that 872 MHz CW RF radiation at 5 W/kg might enhance chemically induced ROS production and thus cause secondary DNA damage. However, there is no known mechanism that would explain such effects from CW RF radiation but not from GSM modulated RF radiation at identical SAR

  18. Radiation-induced loss of unsaturation in 1,2-polybutadiene

    International Nuclear Information System (INIS)

    Golub, M.A.; Cormia, R.D.

    1982-01-01

    The radiation induced loss of unsaturation and methyl production in 1,2-polybutadiene (VB) was studied using IR spectroscopy. It was found that G(-1,2), which depends on the initial vinyl content, decreased from approximately 550 for VB with 98.5% 1,2 initially, to approximately 270 for VB with 85% 1,2 initially. G(-trans-1,4) ranged from approximately 21 for VB with 14% trans-1,4 to nearly zero for VB with less than 1% trans-1,4 initially. Methyl production was found to equal one methyl group formed for every 4-5 vinyl units consumed in the radiation-cyclized VB, in contrast to one methyl formed for every two vinyls reacted during cationic cyclization to give monocyclic structures. The IR spectra of gamma-irradiated VB were very similar to the spectra of UV-irradiated or thermally-treated VB at the same residual vinyl contents. It is suggested that the radiation-induced cyclization of VB occurs by a nonionic, nonradical 'energy chain' mechanism, which apparently holds for the cyclization of VB, whether induced by gamma-rays, UV radiation, or heat

  19. Radiation method of sulfide compound transformation in petroleum products

    International Nuclear Information System (INIS)

    Nadirov, N.K.; Zajkina, R.F.; Zajkin, Yu.A.; Mamonova, T.B.; Bakirova, S.F.

    1997-01-01

    Processes of sulphuric compounds transformation for petroleum and heavy residuals under radiation and thermal treatment action are studied. It is shown that sulphuric compounds are concentrated in heavy fractions as a result of radiation processing. Heavy petroleum products irradiation provokes considerable decrease in the content of mercaptans, disulphides and sulphides, which transfer to sulphoxides and sulphones appearing during radiation-induced oxidation process. (author)

  20. Cataracts induced by microwave and ionizing radiation

    International Nuclear Information System (INIS)

    Lipman, R.M.; Tripathi, B.J.; Tripathi, R.C.

    1988-01-01

    Microwaves most commonly cause anterior and/or posterior subcapsular lenticular opacities in experimental animals and, as shown in epidemiologic studies and case reports, in human subjects. The formation of cataracts seems to be related directly to the power of the microwave and the duration of exposure. The mechanism of cataractogenesis includes deformation of heat-labile enzymes, such as glutathione peroxide, that ordinarily protect lens cell proteins and membrane lipids from oxidative damage. Oxidation of protein sulfhydryl groups and the formation of high-molecular-weight aggregates cause local variations in the orderly structure of the lens cells. An alternative mechanism is thermoelastic expansion through which pressure waves in the aqueous humor cause direct physical damage to the lens cells. Cataracts induced by ionizing radiation (e.g., X-rays and gamma rays) usually are observed in the posterior region of the lens, often in the form of a posterior subcapsular cataract. Increasing the dose of ionizing radiation causes increasing opacification of the lens, which appears after a decreasing latency period. Like cataract formation by microwaves, cataractogenesis induced by ionizing radiation is associated with damage to the lens cell membrane. Another possible mechanism is damage to lens cell DNA, with decreases in the production of protective enzymes and in sulfur-sulfur bond formation, and with altered protein concentrations. Until further definitive conclusions about the mechanisms of microwaves and ionizing radiation induced cataracts are reached, and alternative protective measures are found, one can only recommend mechanical shielding from these radiations to minimize the possibility of development of radiation-induced cataracts. 74 references

  1. Natural products as radiation response modifiers

    International Nuclear Information System (INIS)

    Colin Seymour; Carmel Mothersill

    2007-01-01

    Complete text of publication follows. Protection of cells and organisms against low doses of radiation is a complex issue which must be considered at the level of cells, tissues and organisms. 'Protection' at one level, for example, prevention of cell death, may be adverse at another level, if it allows a damaged cell to survive and form a malignant tumour. Conversely, death of a cell carrying damage can be protective for the organism if it eliminates a damaged cell. Thus, it is important to understand the mechanisms involved in protection against radiation damage at several hierarchical levels. The use of natural products as radiation response modifiers is very attractive. Many of these compounds are readily available and their function and pharmacology is well understood. Some derive from venoms or natural defenses and are currently used in medicine, others include vitamins, antioxidants or cofactors, which are tried and tested nutritional supplements. Radiation effects may be targeted or untargeted. Radiation may interact directly within a cell causing a direct DNA lesion or it may elicit a bystander response from the irradiated cell. A bystander effect is produced when the irradiated cell apparently exhibits no damage from the radiation, but passes on a biochemical signal which induces neighbouring cells to apoptose or undergo a number of other responses usually associated with irradiation such as mutation induction, transformation, induction of ROS responses etc.. Effects induced in progeny of non-targeted cells in receipt of bystander signals include genetic instability, mini and microsatellite mutations and carcinogenesis. A key characteristic of these non targeted effects is that they occur at very low acute doses (of the order of 5mGy) and saturate so that effective prevention requires an agent which can effectively shut off the mechanism. While the mechanism is not fully known, it is thought to involve signals from irradiated cells communicating via

  2. Production and partial characterization of alkaline protease from bacillus subtilis mutant induced by gamma radiation

    International Nuclear Information System (INIS)

    Ibrahim, H.M.M.; Bashandy, A.S.

    2010-01-01

    Fourteen bacterial isolates belonging to B.subtilis were locally isolated from soil and screened for alkaline protease production. Only one strain, the highly potent one, was selected as alkaline protease producer and subjected to further studies to optimize its production. Alkaline protease production was maximum at 35 degree C after 72 h of incubation and at ph 10.0. molasses as a carbon source and combination of peptone and yeast extract as a nitrogen source enhanced greatly alkaline protease production. The mutant strain induced by gamma radiation showed higher alkaline protease production by 1.97 fold as compared with the parent strain. The alkaline protease enzyme was active at 40 degree C and ph 10. It was compatible with many commercial detergents and showed high stability (84 %) of its original activity with Ariel detergent. Moreover, alkaline protease enhanced the washing performance, and retained 95 % of its activity in the formulated dry powder.

  3. Radiation induced peroxidation in model lipid systems

    International Nuclear Information System (INIS)

    Dahlan, K.Z.B.H.M.

    1981-08-01

    In the studies of radiation induced lipid peroxidation, lecithin-liposomes and aqueous micellar solutions of sodium linoleate (or linoleic acid) have been used as models of lipid membrane systems. The liposomes and aqueous linoleate micelles were irradiated in the presence of O 2 and N 2 O/O 2 (80/20 v/v). The peroxidation was initiated using gamma radiation from 60 Co radiation source and was monitored by measuring the increase in absorbance of conjugated diene at 232 nm and by the thiobarbituric acid (TBA) test. The oxidation products were also identified by GLC and GLC-MS analysis. (author)

  4. Radiation-induced thermoacoustic imaging

    International Nuclear Information System (INIS)

    Bowen, T.

    1984-01-01

    This invention provides a new technique for obtaining information non-invasively on the composition and structures of a material or body by detecting radiation-induced thermoacoustic image features. This is accomplished by utilizing the acoustic wave generated by sudden thermal stress. The sudden thermal stress is induced by a pulse of radiation which deposits energy causing a rapid, but very small, rise of temperature (typically, ΔT approximately 10sup(-6) - 10sup(-5) deg C). The radiation may be ionizing radiation, such as high energy electrons, photons (x-rays), neutrons, or other charged particles or it may be non-ionizing radiation, such as R.F. and microwave electromagnetic radiation and ultrasonic radiation. The choice of radiation depends on the nature of the body to be imaged and the type of information desired

  5. Radiation-induced nitration of organic compounds in aqueous solutions

    International Nuclear Information System (INIS)

    Ershov, B.G.; Gordeev, A.V.; Bykov, G.L.

    2009-01-01

    Radiation-induced nitration of organic compounds in aqueous solutions was studied. It was found that γ-irradiation of solutions containing acetic and nitric acid and/or their salts gives nitromethane. Dependences of the product yield on the absorbed dose and the contents of components were established. The mechanism of radiation nitration involving radicals is discussed. (author)

  6. Injection profiles with radiation induced copolymers

    International Nuclear Information System (INIS)

    Knight, B.L.; Rhudy, J.S.; Gogarty, W.B.

    1976-01-01

    The injectivity profile of a heterogeneous formation and/or vertical conformance is improved by injecting an aqueous solution into the formation, the solution containing a polymer obtained as a product of radiation-induced polymerization of acrylamide and/or methacrylamide and acrylic acid, methacrylic acid, and/or alkali metal salts thereof. The polymerization is preferably carried out in a 10 to 60 percent aqueous solution with gamma radiation; the aqueous monomer solution preferably contains 25 to 99 percent acrylamide and 1 to 75 percent sodium acrylate. Immiscible, miscible, or miscible-like displacing processes can be used in conjunction with this invention. 20 claims

  7. Radiation-induced centers in inorganic glasses

    International Nuclear Information System (INIS)

    Brekhovskikh, S.M.; Tyul'nin, V.A.

    1988-01-01

    The nature, structure and formation mechanisms of radiation-induced colour centers, EPR, luminescence, generated ionizing radiation in nonorganic oxide glasses are considered. Experimental material covering both fundamental aspects of radiation physics and glass chemistry, and aspects intimately connected with the creation of new materials with the given radiation-spectral characteristics, with possibilities to prepare radiation-stable and radiation-sensitive glasses is systematized and generalized. Considerable attention is paid to the detection of radiation-induced center binding with composition, glass structures redox conditions for their synthesis. Some new possibilities of practical application of glasses with radiation-induced centers, in particular, to record optical information are reflected in the paper

  8. ROS Mediates Radiation-Induced Differentiation in Human Lung Fibroblast

    International Nuclear Information System (INIS)

    Park, Sa Rah; Ahn, Ji Yeon; Kim, Mi Hyeung; Lim, Min Jin; Yun, Yeon Sook; Song, Jie Young

    2009-01-01

    One of the most common tumors worldwide is lung cancer and the number of patients with lung cancer received radiotherapy is increasing rapidly. Although radiotherapy may have lots of advantages, it can also induce serious adverse effects such as acute radiation pneumonitis and pulmonary fibrosis. Pulmonary fibrosis is characterized by excessive production of smooth muscle actin-alpha (a-SMA) and accumulation of extracellular matrix (ECM) such as collagen and fibronectin. There has been a great amount of research about fibrosis but the exact mechanism causing the reaction is not elucidated especially in radiation-induced fibrosis. Until now it has been known that several factors such as transforming growth factor (TGF-b), tumor necrosis factor (TNF), IL-6, platelet-derived growth factor (PDGF) and reactive oxygen species are related to fibrosis. It is also reported that reactive oxygen species (ROS) can be induced by radiation and can act as a second messenger in various signaling pathways. Therefore we focused on the role of ROS in radiation induced fibrosis. Here, we suggest that irradiation generate ROS mainly through NOX4, result in differentiation of lung fibroblast into myofibroblast

  9. Study of radiation induced structural changes in nitrile rubber

    International Nuclear Information System (INIS)

    Cardona, F.; Hill, D.J.T.; Pomery, P.J.; Whittaker, A.K.

    1996-01-01

    Full text: Copolymers of butadiene (BD) and acrylonitrile (AN) (NBR rubber), have become important commercial material. NBR rubbers are part of a larger classification of products often referred to as special-purpose rubbers. Oil resistance is the most important property of nitrile rubbers, and refer to the ability of the vulcanised product to retain its original physical properties such as modulus, tensile strength, abrasion resistance and dimensions, while in contact with oils and fuels. Despite these reported advantages very few studies have been conducted on the radiation yields and structural changes in nitrile rubbers during exposure to high energy radiation. In this study we are investigating the stability against gamma and UV radiation, to different doses in vacuum, of butadiene, acrylonitrile and NBR copolymers with different composition ratio BD/AN. The mechanism of radiation induced structural changes is being investigated using experimental techniques such as ESR, NMR (Solid-state), FT-IR, RAMAN and UV spectroscopy. Also is being investigated the effect of irradiation on the mechanical properties of stressed and unstressed samples by TGA, DSC, DMA, Instron and Creep Test measurements. So far the main effect have been a marked radiation-induced loss of unsaturation in the butadiene units, cis to trans isomerization and formation of crosslink structures (intermolecular and intramolecular). One of the main challenges in the studies of NBR polymers is to observe directly the crosslinks produces by the radiation induced chemical reactions. IR spectroscopy is unsuitable because of the low molar absorbity of the peaks related to intermolecular crosslinking and the overlapping of the peaks (1630-1670 cm-1) related to intramolecular crosslinking (cyclization), with conjugated and nonconjugated (-C=C-; -C=N-) double bonds. A. K. Whittaker has shown that crosslink structures in PBD can be detected and measured directly using solid-state 13 C NMR. This technique

  10. Application of controlled radiation-induced degradation in polymers: less exploited aspect of radiation processing of polymers

    International Nuclear Information System (INIS)

    Haji Saeid, M.; Guven, O.

    2007-01-01

    Industrial use of ionizing radiation treatment has been most successful in applications related to polymeric materials. The polymer, plastics and rubber industries have benefited from the unique advantages of ionizing radiation since its inception as an industrial tool to modify their properties and manufacture novel materials with value addition to the end product. The established and emerging applications of electron beam processing of polymers are based on the well known ultimate effects of ionizing radiation on polymers namely, crosslinking, curing, grafting and chain scissioning. Radiation-induced crosslinking dominates most applications, whereas the chain scissioning effect is much less explored and currently limited to radiation-induced degradation of Teflon, cellulose and polypropylene. The controlling of radiation-induced degradation for achieving a target average molecular weight or distribution has been evaluated for some polysaccharides, biopolymers and waste inner tubes whereas mitigation of the degradative effects of radiation has been analyzed from the point of view of using certain stabilizers, copolymers and annealing at an appropriate temperature. Several new or highly specialized techniques such as positron annihilation lifetime spectroscopy. Rutherford backscattering, elastic recoil detection analysis and solid waste NMR spectroscopy and gas chromatography-mass spectroscopy have been applied to the study or radiation-induced degradation. New information has been collected on the morphological changes associated with radiation-induced degradation processes, including chain scission, oxidation and free volume alteration. The IAEA coordinated research project (CRP) on Controlling of Degradation Effects in Radiation Processing of Polymers dealt with the role and importance of using ionizing radiation in controlling properties of natural and synthetic polymers through its degradative effect. This paper provides a summary of most important results

  11. Radiation-induced camptocormia and dropped head syndrome. Review and case report of radiation-induced movement disorders

    International Nuclear Information System (INIS)

    Seidel, Clemens; Kuhnt, Thomas; Kortmann, Rolf-Dieter; Hering, Kathrin

    2015-01-01

    In recent years, camptocormia and dropped head syndrome (DHS) have gained attention as particular forms of movement disorders. Camptocormia presents with involuntary forward flexion of the thoracolumbar spine that typically increases during walking or standing and may severely impede walking ability. DHS is characterized by weakness of the neck extensors and a consecutive inability to extend the neck; in severe cases the head is fixed in a ''chin to chest position.'' Many diseases may underlie these conditions, and there have been some reports about radiation-induced camptocormia and DHS. A PubMed search with the keywords ''camptocormia,'' ''dropped head syndrome,'' ''radiation-induced myopathy,'' ''radiation-induced neuropathy,'' and ''radiation-induced movement disorder'' was carried out to better characterize radiation-induced movement disorders and the radiation techniques involved. In addition, the case of a patient developing camptocormia 23 years after radiation therapy of a non-Hodgkin's lymphoma of the abdomen is described. In total, nine case series of radiation-induced DHS (n = 45 patients) and - including our case - three case reports (n = 3 patients) about radiogenic camptocormia were retrieved. Most cases (40/45 patients) occurred less than 15 years after radiotherapy involving extended fields for Hodgkin's disease. The use of wide radiation fields including many spinal segments with paraspinal muscles may lead to radiation-induced movement disorders. If paraspinal muscles and the thoracolumbar spine are involved, the clinical presentation can be that of camptocormia. DHS may result if there is involvement of the cervical spine. To prevent these disorders, sparing of the spine and paraspinal muscles is desirable. (orig.) [de

  12. Radiation induced degradation of dyes-An overview

    International Nuclear Information System (INIS)

    Rauf, M.A.; Ashraf, S. Salman

    2009-01-01

    Synthetic dyes are a major part of our life. Products ranging from clothes to leather accessories to furniture all depend on extensive use of organic dyes. An unfortunate side effect of extensive use of these chemicals is that huge amounts of these potentially carcinogenic compounds enter our water supplies. Various advanced oxidation processes (AOPs) including the use of high-energy radiation have been developed to degrade these compounds. In this review, dye decoloration and degradation as a result of its exposure to high energy radiation such as gamma radiation and pulsed electron beam are discussed in detail. The role of various transient species such as ·H, ·OH and e aq - are taken into account as reported by various researchers. Literature citations in this area show that e aq - is very effective in decolorization but is less active in the further degradation of the products formed. The degradation of the dyes is initiated exclusively by ·OH attack on electron-rich sites of the dye molecules. Additionally, various parameters that affect the efficiency of radiation induced degradation of dyes, such as effect of radiation dose, oxygen, pH, hydrogen peroxide, added ions and dye classes are also reviewed and summarized. Lastly, pilot plant application of radiation for wastewater treatment is briefly discussed.

  13. On the mechanisms of the radiation-induced degradation of cellulosic substances

    Science.gov (United States)

    Tissot, Chanel; Grdanovska, Slavica; Barkatt, Aaron; Silverman, Joseph; Al-Sheikhly, Mohamad

    2013-03-01

    Much interest has been generated in utilizing ionizing radiation for the production of bio-fuels from cellulosic plant materials. It is well known that exposure of cellulose to ionizing radiation causes significant breakdown of the polysaccharide. Radiation-induced degradation of cellulose may reduce or replace ecologically hazardous chemical steps in addition to reducing the number of processing stages and decreasing energy consumption.

  14. Extracellular adenosine production by ecto-5′-nucleotidase (CD73) enhances radiation-induced lung fibrosis

    Science.gov (United States)

    Wirsdörfer, Florian; de Leve, Simone; Cappuccini, Federica; Eldh, Therese; Meyer, Alina V.; Gau, Eva; Thompson, Linda F.; Chen, Ning-Yuan; Karmouty-Quintana, Harry; Fischer, Ute; Kasper, Michael; Klein, Diana; Ritchey, Jerry W.; Blackburn, Michael R.; Westendorf, Astrid M.; Stuschke, Martin; Jendrossek, Verena

    2016-01-01

    Radiation-induced pulmonary fibrosis is a severe side effect of thoracic irradiation, but its pathogenesis remains poorly understood and no effective treatment is available. In this study, we investigated the role of the extracellular adenosine as generated by the ecto-5'-nucleotidase CD73 in fibrosis development after thoracic irradiation. Exposure of wild-type C57BL/6 mice to a single dose (15 Gray) of whole thorax irradiation triggered a progressive increase in CD73 activity in the lung between 3 and 30 weeks post-irradiation. In parallel, adenosine levels in bronchoalveolar lavage fluid (BALF) were increased by approximately three-fold. Histological evidence of lung fibrosis was observed by 25 weeks after irradiation. Conversely, CD73-deficient mice failed to accumulate adenosine in BALF and exhibited significantly less radiation-induced lung fibrosis (P<0.010). Furthermore, treatment of wild-type mice with pegylated adenosine deaminase (PEG-ADA) or CD73 antibodies also significantly reduced radiation-induced lung fibrosis. Taken together, our findings demonstrate that CD73 potentiates radiation-induced lung fibrosis, suggesting that existing pharmacological strategies for modulating adenosine may be effective in limiting lung toxicities associated with the treatment of thoracic malignancies. PMID:26921334

  15. Radiation-induced desulfurization of Arabian crude oil and straight-run diesel

    International Nuclear Information System (INIS)

    Basfar, A.A.; Mohamed, K.A.

    2011-01-01

    Radiation-induced desulfurization of four types of Arabian crude oils (heavy, medium, light and extra light) and straight-run diesel (SRD) was investigated over the range of 10-200 kGy. Results show that gamma radiation processing at absorbed doses up to 200 kGy without further treatment is not sufficient for desulfurization. However, the combination of gamma-irradiation with other physical/chemical processes (i.e. L/L extraction, adsorption and oxidation) may be capable of removing considerable levels of sulfur compounds in the investigated products. Currently, this approach of combined radiation/physical/chemical processes is under investigation. The findings of these attempts will be reported in the future. - Highlights: → Irradiation effect on desulfurization in Arabian crude oils and straight-run diesel was investigated. → No noticeable changes in sulfur content after irradiation up to 200 kGy were observed. → Stricter regulations on sulfur levels in fuels motivate search for improved desulfurization processes. → Limited investigations on radiation-induced desulfurization of oil products are conducted.

  16. Contribution of radiation-induced, nitric oxide-mediated bystander effect to radiation-induced adaptive response.

    Science.gov (United States)

    Matsumoto, H.; Ohnishi, T.

    There has been a recent upsurge of interest in radiation-induced adaptive response and bystander effect which are specific modes in stress response to low-dose low-dose rate radiation Recently we found that the accumulation of inducible nitric oxide NO synthase iNOS in wt p53 cells was induced by chronic irradiation with gamma rays followed by acute irradiation with X-rays but not by each one resulting in an increase in nitrite concentrations of medium It is suggested that the accumulation of iNOS may be due to the depression of acute irradiation-induced p53 functions by pre-chronic irradiation In addition we found that the radiosensitivity of wt p53 cells against acute irradiation with X-rays was reduced after chronic irradiation with gamma rays This reduction of radiosensitivity of wt p53 cells was nearly completely suppressed by the addition of NO scavenger carboxy-PTIO to the medium This reduction of radiosensitivity of wt p53 cells is just radiation-induced adaptive response suggesting that NO-mediated bystander effect may considerably contribute to adaptive response induced by radiation

  17. Radiological-morphological synopsis of radiation-induced lung fibrosis

    International Nuclear Information System (INIS)

    Bublitz, G.

    1977-01-01

    As delayed radiation damage after treatment of bronchial carcinoma and mamma carcinoma, fibroses occur as a reaction of the tissues. They have become a clinical-functional syndrome because of their uniform clinicaL-radiological symptomatology and pathophysiology. Pulmonary fibrosis as delayed radiation damage has a special importance with its two different radiation effects on connective tissue: a) on existing structures, b) delayed alterations of the connective tissue. As seen from experiments on lungs of men and rats, radiation-induced alterations can be measured by testing the different solubilities of the collagen types. In addition to the pathologically disordered collagen production, 9 weeks after the irradiation the radiation fibrosis leads to an isolated increase of insoluble collagen corresponding to the formation of metabolism-resistant fibrils. (MG) [de

  18. Radiation-induced instability of human genome

    International Nuclear Information System (INIS)

    Ryabchenko, N.N.; Demina, Eh.A.

    2014-01-01

    A brief review is dedicated to the phenomenon of radiation-induced genomic instability where the increased level of genomic changes in the offspring of irradiated cells is characteristic. Particular attention is paid to the problems of genomic instability induced by the low-dose radiation, role of the bystander effect in formation of radiation-induced instability, and its relationship with individual radiosensitivity. We believe that in accordance with the paradigm of modern radiobiology the increased human individual radiosensitivity can be formed due to the genome instability onset and is a significant risk factor for radiation-induced cancer

  19. Natural Products Garlic Oil and Vitamin E, Control Radiation Induced Disorders of Lipid and Carbohydrate Metabolism in Rats

    International Nuclear Information System (INIS)

    Ragab, E.A.; Ashry, O.M.

    2004-01-01

    Increased level of lipid peroxides in various tissues of irraiated animals, may play a crucial role in determining the pathogenesis of radiation exposure. Many of the damaging effects of ionizing radiation are mediated by reactive free radicals. The efficacy of oral treatment of rats with garlic oil (100 mg/kg body weight) for ten days and intraperitoneal administration of vitamin E (100mg/kg body wt.) two hours before whole body gamma irradiation (7Gy), was examine on certain biochemical parameters. The data obtained revealed that, radiation exposure caused increase in serum malondialdehyde level (indicating lipid peroxiation accompanied by increase in serum total lipid, trigacylglycerol, cholesterol an low density lipoprotein with significant decrease in high density lipoprotein. Radiation exposure also induced significant elevation in serum glucose level, liver glycogen and liver glucose 6-phosphatase activity level. Administration of the natural product (garlic oil) and /or vitamin E ameliorates the radiation inuced disturbances in lipid and carbohydrate metabolism. The study confirmed the beneficial role of the used antioxidative agents as recommended radioprotectors due to their ability of scavenging free radicals produced by ionizing radiation or oxidative stress

  20. Modulating factors in the expression of radiation-induced oncogenic transformation

    International Nuclear Information System (INIS)

    Hall, E.J.; Hei, T.K.

    1990-01-01

    Many assays for oncogenic transformation have been developed ranging from those in established rodent cell lines where morphological alteration is scored, to those in human cells growing in nude mice where tumor invasiveness is scored. In general, systems that are most quantitaive are also the least relevant in terms of human carcinogenesis and human risk estimation. The development of cell culture systems has made it possible to assess at the cellular level the oncogenic potential of a variety of chemical, physical and viral agents. Cell culture systems afford the opportunity to identify factors and conditions that may prevent or enhance cellular transformation by radiation and chemicals. Permissive and protective factors in radiation-induced transformation include thyroid hormone and the tumor promoter TPA that increase the transformation incidence for a given dose of radiation, and retinoids, selenium, vitamin E, and 5-aminobenzamide that inhibit the expression of transformation. Densely ionizing α-particles, similar to those emitted by radon daughters, are highly effective in inducing transformations and appear to interact in a supra-additive fashion with asbestos fibers. The activation of a known dominant oncogene has not yet been demonstrated in radiation-induced oncogenic transformation. The most likely mechanism for radiation activation of an oncogene would be via the production of a chromosomal translocation. Radiation also efficiently induces deletions and may thus lead to the loss of a suppressor gene

  1. Radiation-induced heart injury

    International Nuclear Information System (INIS)

    Suzuki, Yoshihiko; Niibe, Hideo

    1975-01-01

    In order to identify radiation-induced heart injury and to differentiate it from heart disease, an attempt was made to clarify post-irradiation heart injury by investigating the histological changes which occur during the internal between the irradiation and the time of demonstrable histological changes. A study was made of 83 autopsies in which most of the primary neoplasms were breast cancers, lung cancers and mediastinal tumors. In 43 of these autopsies the heart had been irradiated. Sixty eight dd-strain mice were also used for microautoradiographic study. Histological changes in the heart were observed in 27 of the 43 cases receiving irradiation. The limit of the tolerance dose to the heart for indicating histological changes was 1220 ret in humans. The latent period without histological changes was 2.7 months after initiation of radiation therapy. Greater heart injury was observed after re-irradiation or after the combined therapy of radiation and chemotherapy especially mitomycin (MMC). The histological findings after treatment with MMC were similar to those of radiation-induced heart injury. Results of the study indicate that the damage is secondary to radiation-induced changes of the vascula connective tissue. (Evans, G.)

  2. Modulation of radiation induced DNA damage by natural products in hemopoietic tissue of mice

    International Nuclear Information System (INIS)

    Jayakumar, S.; Bhilwade, H.N.; Chaubey, R.C.

    2014-01-01

    Ionizing radiation is known to induce oxidative stress through generation of ROS leading to a variety of DNA lesions. However, the most dangerous DNA lesions which are responsible for the origin of lethal effects, mutagenesis, genomic instability and carcinogenesis are the DSBs. During recent years efforts are being made to identify phytochemicals, antioxidants or neutraxeuticals which can reduce harmful effect of radiation during accidental exposure or prevent normal tissue injury during radiotherapy. In the present study, we have investigated the radioprotective role of curcumin, a dietary antioxidant, taurine, malabaricone-C, and umbelliferone, for their radioprotective properties in hemopoietic cells of mice. Groups of mice-were fed 1% of curcumin in diet for three weeks. Similarly other groups of mice were injected i.p. with 50 mg/kg body weight of taurine for five consecutive days. After the completion of the treatment mice pre-treated with curcumin and taurine were exposed to 3 Gy of gamma rays. Malabaricone-C was tested for its radiomodulation potential in vitro, in spleenocytes of mouse. Spleenocytes were isolated and treated with different concentrations (0.5-25 ìM) of malabaricone-C. Immediately after irradiation, alkaline comet assay were performed using standard procedures. Twenty four post radiation exposure mice were sacrificed for micronucleus test. Results of these studies showed significant reduction in DNA damage by curcumin. The micronucleus data showed marginal increase in the frequency of micronucleated erythrocytes in curcumin fed group as compared to the controls. Mice receiving curcumin for 3 weeks in diet followed by gamma radiation (3 Gy), showed approximately 50% reduction in the frequency of micro nucleated polychromatic erythrocytes. Pre-treatment of mice with taurine significantly (p < 0.01) reduced the frequency of gamma rays induced mn-PCEs in bone marrow tissue. Malabaricone-C at 1.5 ìM concentration showed very good protection

  3. Radiation induced degradation of DNA in photodynamic therapy of cancer

    International Nuclear Information System (INIS)

    Ion, Rodica; Scarlat, F.; Niculescu, V.I.R.; Scarlat, Fl.; Gunaydin, Keriman

    2001-01-01

    DNA is a critical cellular target for oxidative processes induced by physical and chemical stresses. It is known that the direct effect of ionizing radiation on DNA results mainly in base ionization and may lead to mutation, carcinogenesis and cell death. The degradation of DNA induced by laser and ionizing radiation (electron and photon beam) is analyzed in this paper. The ionizing radiation degradation of DNA is a radical process. A series of lesions among the major base degradation product has been measured in isolated DNA exposed to gamma radiation in aerated aqueous solution. Degradation can be accounted for by the formation of hydroxyl radicals upon radiolysis of water (indirect effect). The production of DNA damage by ionizing radiation involves two mechanisms, direct and indirect effects. Direct effect leads to ionization and excitation of DNA molecules, while indirect effect is due to the interaction of reactive species, in particular of OH radicals produced by water radiolysis, with targets in DNA. The relative contribution of the two mechanisms in damaging DNA depends on the type of radiation. Single strand breaks and base damage seem to be mainly produced by the attack of hydroxyl radicals on DNA, whereas double strand breaks result predominantly of direct energy deposition. The four bases are degraded in high yield. Direct effect has been mimicked by photo-induced electron abstraction from the bases producing their radical cation. The base damage may also occur from the formation of radical cation of purine and pyrimidine components. When DNA is irradiated in solution, single strand breaks are mainly due to the abstraction of an H atom from the 4 ' position of 2 ' -deoxyribose by the attack of OH radicals produced by water radiolysis. Quantification of the modified bases showed the guanine is the preferential target. Ionizing radiation induces several types of DNA modifications, including chain breaks, DNA-protein cross-links, oxidized DNA bases

  4. Radiation-induced gene expression in human subcutaneous fibroblasts is predictive of radiation-induced fibrosis

    DEFF Research Database (Denmark)

    Rødningen, Olaug Kristin; Børresen-Dale, Anne-Lise; Alsner, Jan

    2008-01-01

    BACKGROUND AND PURPOSE: Breast cancer patients show a large variation in normal tissue reactions after ionizing radiation (IR) therapy. One of the most common long-term adverse effects of ionizing radiotherapy is radiation-induced fibrosis (RIF), and several attempts have been made over the last...... years to develop predictive assays for RIF. Our aim was to identify basal and radiation-induced transcriptional profiles in fibroblasts from breast cancer patients that might be related to the individual risk of RIF in these patients. MATERIALS AND METHODS: Fibroblast cell lines from 31 individuals......-treated fibroblasts. Transcriptional differences in basal and radiation-induced gene expression profiles were investigated using 15K cDNA microarrays, and results analyzed by both SAM and PAM. RESULTS: Sixty differentially expressed genes were identified by applying SAM on 10 patients with the highest risk of RIF...

  5. 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)

  6. Stimulation of respiration in rat thymocytes induced by ionizing radiation

    International Nuclear Information System (INIS)

    Gudz, T.I.; Pandelova, I.G.; Novgorodov, S.A.

    1994-01-01

    The effect of X irradiation on the respiration of rat thymocytes was studied. An increase in the rate of O 2 uptake was observed 1 h after cells were irradiated with doses of 6-10 Gy. The radiation-induced increase in respiration could be blocked by oligomycin, an inhibitor of mitochondrial ATP synthase, suggesting control by increased cytoplasmic ATP turnover. The stimulation of respiration was not associated with changes in the activity of mitochondrial electron transfer enzymes or permeability of the inner membrane. Several inhibitors of processes which used ATP were screened for their effects on the basal respiration rate and on the radiation response. In irradiated thymocytes, an enhancement of inhibition of respiration by ouabain, La 3+ and cycloheximide was observed. These results indicate that the radiation-induced stimulation of respiration is due to changes in ion homeostasis and protein synthesis. The effect of X irradiation was shown to be independent of the redox status of nonprotein thiols and was not associated with detectable changes in some products of lipid peroxidation. The radiation-induced decrease in activity of superoxide dismutase suggests free radical involvement in deleterious effects of radiation. 43 refs., 2 figs., 3 tabs

  7. Physiological bases and treatment to the radiation-induced emetic reflex

    International Nuclear Information System (INIS)

    Mulen Napoles, Barbara M.; Torres Babie, Priscilla; Ropero Toirac, Ramon de J.

    2002-01-01

    In the course of the specific oncologic treatment, there are frequent complications such as nausea and vomiting. The radiation-induced emetic reflex depends on various factors: primary site of radiation, administered dose, fractioning, irradiated volume, the sensory and psychic characteristics of the patient as well as the chemotherapy association. It is known that the afferent path to the so-called center of vomiting is determined by chemical mediators, protuberance receptors of the intracranial pressure and the unleashing chemoreceptor zone. In radiation-induced emesis, the exact mechanism is yet to be determined but it is known that radiation stimulates the production of chemical mediators and serotonin released by enterochromaffin cells that act upon the center of vomiting and vagal nucleus. Most of patients who are exposed to irradiation of their upper and middle hemibody as well as all the patients exposed to whole-body irradiation present with nausea and vomiting. The therapeutical anti-emetic recommendations are based on the neurochemical control of vomiting and the emetogenic effect of radiotherapy. 5HT3 receptor-antagonists are evaluated as effective agents in the control of radiation-induced emesis

  8. Radiation-induced pneumothorax

    International Nuclear Information System (INIS)

    Epstein, D.M.; Littman, P.; Gefter, W.B.; Miller, W.T.; Raney, R.B. Jr.

    1983-01-01

    Pneumothorax is an uncommon complication of radiation therapy to the chest. The proposed pathogenesis is radiation-induced fibrosis promoting subpleural bleb formation that ruptures resulting in pneumothorax. We report on two young patients with primary sarcomas without pulmonary metastases who developed spontaneous pneumothorax after irradiation. Neither patient had antecedent radiographic evidence of pulmonary fibrosis

  9. Radiation induced sarcomas of bone following therapeutic radiation

    International Nuclear Information System (INIS)

    Kim, J.H.; Chu, F.C.H.; Woodward, H.Q.; Huvos, A.

    1983-01-01

    Because of new therapeutic trends of multi-modality and the importance of late effects, we have updated our series of radiation induced bone sarcomas seen at Memorial Sloan-Kettering Cancer Center over the past four decades. A total of 37 cases of bone sarcoma arising from normal bone in the irradiated field was analyzed. The median for latent period from irradiation to diagnosis of bone sarcoma was 11 years with a minimum latent period of four years. The median radiation dose for the bone sarcoma was 6000 rad in 6 weeks with a minimum total radiation dose of 3000 rad in 3 weeks. We have found nine patients who developed bone sarcomas in the radiation field after successful treatment of Hodgkin's disease. Criteria for radiation induced bone sarcomas and the magnitude of the risk of bone sarcomas are briefly discussed

  10. Radiation-induced oxidative chemical changes in dehydrated egg products

    International Nuclear Information System (INIS)

    Katusin-Rasem, B.; Mihaljevic, B.; Razem, D.

    1992-01-01

    Radiation-induced buildup of lipid hydroperoxides (LOOH) and destruction of carotenoids were followed in whole egg powder and egg yolk powder as functions of dose, dose rate, and the presence of oxygen. In the absence of air the formation of LOOH was limited by the available oxygen, while destruction of carotenoids progressed linearly with dose; neither process depended on the dose rate. In the presence of air, the accumulation of LOOH and the destruction of carotenoids were strongly coupled and inversely proportional to the dose rate. The induction dose of 2.5 kGy was observed in air in both whole egg powder and egg yolk powder, independent of the dose rate. The practical consequence is that radiation decontamination can be carried out in the presence of air at the highest available dose rate by a dose not exceeding 2.5 kGy to avoid extensive degradation. This dose is adequate for a 10(3) reduction factor of Salmonella and well within the threshold dose of 3 kGy for organoleptic changes

  11. Radiation-induced bone neoplasma in facial cranium

    Energy Technology Data Exchange (ETDEWEB)

    Zomer-Drozda, J; Buraczewska-Lipinska, H; Buraczewski, J [Instytut Onkologii, Warsaw (Poland)

    1976-01-01

    Radiation-induced bone neoplasms in the region of facial cranium account for about 40% of all radiation-induced tumours of bones, although the number of cases with lesions irradiated in this area is proportionally much lower than the number of cases treated with radiotherapy in other parts of the body. Four personal cases of radiation-induced tumours with complicated course are reported. Attention is called to the value of radiological investigations in the diagnosis of bone diseases and in differential diagnosis of radiation-induced tumours of bones.

  12. Regulation of radiation-induced protein kinase Cδ activation in radiation-induced apoptosis differs between radiosensitive and radioresistant mouse thymic lymphoma cell lines

    International Nuclear Information System (INIS)

    Nakajima, Tetsuo; Yukawa, Osami; Tsuji, Hideo; Ohyama, Harumi; Wang, Bing; Tatsumi, Kouichi; Hayata, Isamu; Hama-Inaba, Hiroko

    2006-01-01

    Protein kinase Cδ (PKCδ) has an important role in radiation-induced apoptosis. The expression and function of PKCδ in radiation-induced apoptosis were assessed in a radiation-sensitive mouse thymic lymphoma cell line, 3SBH5, and its radioresistant variant, XR223. Rottlerin, a PKCδ-specific inhibitor, completely abolished radiation-induced apoptosis in 3SBH5. Radiation-induced PKCδ activation correlated with the degradation of PKCδ, indicating that PKCδ activation through degradation is involved in radiation-induced apoptosis in radiosensitive 3SBH5. In radioresistant XR223, radiation-induced PKCδ activation was lower than that in radiosensitive 3SBH5. Cytosol PKCδ levels in 3SBH5 decreased markedly after irradiation, while those in XR223 did not. There was no apparent change after irradiation in the membrane fractions of either cell type. In addition, basal cytosol PKCδ levels in XR223 were higher than those in 3SBH5. These results suggest that the radioresistance in XR223 to radiation-induced apoptosis is due to a difference in the regulation of radiation-induced PKCδ activation compared to that of 3SBH5. On the other hand, Atm -/- mouse thymic lymphoma cells were more radioresistant to radiation-induced apoptosis than wild-type mouse thymic lymphoma cells. Irradiated wild-type cells, but not Atm -/- cells, had decreased PKCδ levels, indicating that the Atm protein is involved in radiation-induced apoptosis through the induction of PKCδ degradation. The decreased Atm protein levels induced by treatment with Atm small interfering RNA had no effect on radiation-induced apoptosis in 3SBH5 cells. These results suggest that the regulation of radiation-induced PKCδ activation, which is distinct from the Atm-mediated cascade, determines radiation sensitivity in radiosensitive 3SBH5 cells

  13. 3 cases of radiation-induced sarcoma

    International Nuclear Information System (INIS)

    Shiba, Keiichiro; Fukuma, Hisatoshi; Beppu, Yasuo; Hirota, Teruyuki; Shinohara, Norio.

    1982-01-01

    Criteria for the diagnosis of radiation-induced sarcoma have been previously described. All cases must have a history of irradiation and the second neoplasm must have arisen in the area of the radiation field. A latent period of several years must have elapsed after irradiation before clinical evidence of a second malignant neoplasm. Most important thing is that, all suspected cases must have been proved histologically. We have experienced 3 cases of radiation-induced sarcoma, they were 42-years-old man who developed an osteosarcoma of the lumbar spine at the field of postoperative irradiation for seminoma 7 years previously, 69-years-old woman who developed a malignant fibrous histiocytoma of the buttock at the field of radical radiation for uterine carcinoma 7 years previously and 59-years-old woman who developed an extraskeletal osteosarcoma of the abdominal wall at the field of postoperative irradiation for uterine sarcoma 7 years previously. The last case is very rare and only 8 cases of radiation-induced extraskeletal osteosarcoma have been reported. Since there has been a definite trend in the treatment of cancer toward employing radiation for more favorable cases, in addition to technical improvements in the administration of radiotherapy and more modern equipment, survival data may have been altered considerably in many malignant tumors. Accordingly, more radiation-induced tumors may be encountered in the future. The clinical presentation and histopathology of these radiation-induced sarcomas are presented with a review of the literature. (author)

  14. Ultraviolet radiation directly induces pigment production by cultured human melanocytes

    International Nuclear Information System (INIS)

    Friedmann, P.S.; Gilchrest, B.A.

    1987-01-01

    In humans the major stimulus for cutaneous pigmentation is ultraviolet radiation (UVR). Little is known about the mechanism underlying this response, in part because of the complexity of interactions in whole epidermis. Using a recently developed culture system, human melanocytes were exposed daily to a physiologic range of UVR doses from a solar simulator. Responses were determined 24 hours after the last exposure. There was a dose-related increase in melanin content per cell and uptake of 14 C-DOPA, accompanied by growth inhibition. Cells from donors of different racial origin gave proportionately similar increases in melanin, although there were approximately tenfold differences in basal values. Light and electron microscopy revealed UVR-stimulated increases in dendricity as well as melanosome number and degree of melanization, analogous to the well-recognized melanocyte changes following sun exposure of intact skin. Similar responses were seen with Cloudman S91 melanoma cells, although this murine cell line required lower UVR dosages and fewer exposures for maximal stimulation. These data establish that UVR is capable of directly stimulating melanogenesis. Because cyclic AMP elevation has been associated in some settings with increased pigment production by cultured melanocytes, preliminary experiments were conducted to see if the effects of UVR were mediated by cAMP. Both alpha-MSH and isobutylmethylxanthine (IBMX), as positive controls, caused a fourfold increase in cAMP level in human melanocytes and/or S91 cells, but following a dose of UVR sufficient to stimulate pigment production there was no change in cAMP level up to 4 hours after exposure. Thus, it appears that the UVR-induced melanogenesis is mediated by cAMP-independent mechanisms

  15. Product analysis for polyethylene degradation by radiation and thermal ageing

    International Nuclear Information System (INIS)

    Sugimoto, Masaki; Shimada, Akihiko; Kudoh, Hisaaki; Tamura, Kiyotoshi; Seguchi, Tadao

    2013-01-01

    The oxidation products in crosslinked polyethylene for cable insulation formed during thermal and radiation ageing were analyzed by FTIR-ATR. The products were composed of carboxylic acid, carboxylic ester, and carboxylic anhydride for all ageing conditions. The relative yields of carboxylic ester and carboxylic anhydride increased with an increase of temperature for radiation and thermal ageing. The carboxylic acid was the primary oxidation product and the ester and anhydride were secondary products formed by the thermally induced reactions of the carboxylic acids. The carboxylic acid could be produced by chain scission at any temperature followed by the oxidation of the free radicals formed in the polyethylene. The results of the analysis led to formulation of a new oxidation mechanism which was different from the chain reactions via peroxy radicals and peroxides. - Highlights: ► Products analysis of polyethylene degradation by radiation and thermal ageing. ► Components of carbonyl compounds produced in polyethylene by thermal and radiation oxidation were determined by FTIR. ► Carbonyl compounds comprised carboxylic acid, carboxylic ester, and carboxylic anhydride. ► Carboxylic acid was the primary oxidation product of chain scission at any oxidation temperature. ► Carboxylic ester and carboxylic anhydride are secondary products formed from carboxylic acid at higher temperature.

  16. Immobilization of yeast cells by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Fujimura, T.; Kaetsu, I.

    1982-01-01

    Radiation-induced polymerization method was applied to the immobilization of yeast cells. The effects of irradiation, cooling and monomer, which are neccessary for polymerization, were recovered completely by subsequent aerobical incubation of yeast cells. The ethanol productive in immobilized yeast cells increased with the increase of aerobical incubation period. The growth of yeast cells in immobilized yeast cells was indicated. The maximum ethanol productivity in immobilized yeast cell system was around three times as much as that in free yeast cell system. (orig.)

  17. Radiation-induced O-glycoside bond scission in carbohydrates

    International Nuclear Information System (INIS)

    Kisel', R.M.

    2005-01-01

    Regularities in formation of products resulting from O-glycoside bond cleavage on radiolysis of aqueous solutions of (-methyl-D-glucopyranoside (I), 3-O-methylglucopyranose (II), maltose and lactose were studied. Oxygen and quinones were shown to inhibit radiation-induced homolytic destruction processes taking place in glycosides. The data obtained in this study enabled the authors to demonstrate an important role played by fragmentation reaction of C-2 radicals generated from the starting substances in formation of final radiolysis products. (authors)

  18. Radiation-induced radical ions in calcium sulfite

    Science.gov (United States)

    Bogushevich, S. E.

    2006-07-01

    We have used EPR to study the effect of γ radiation on calcium sulfite. We have observed and identified the radiation-induced radical ions SO 2 - (iso) with g = 2.0055 and SO 2 - (orth-1) with g1 = 2.0093, g2 = 2.0051, g3 = 2.0020, identical to the initial and thermally induced SO 2 - respectively, SO 3 - (iso) with g = 2.0031 and SO 3 - (axial) with g⊥ = 2.0040, g∥ = 2.0023, identical to mechanically induced SO 3 - . We have established the participation of radiation-induced radical ions SO 3 - in formation of post-radiation SO 2 - .

  19. 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)

  20. Radiation-induced camptocormia and dropped head syndrome. Review and case report of radiation-induced movement disorders

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, Clemens; Kuhnt, Thomas; Kortmann, Rolf-Dieter; Hering, Kathrin [Leipzig University, Department of Radiotherapy and Radiation Oncology, Leipzig (Germany)

    2015-10-15

    In recent years, camptocormia and dropped head syndrome (DHS) have gained attention as particular forms of movement disorders. Camptocormia presents with involuntary forward flexion of the thoracolumbar spine that typically increases during walking or standing and may severely impede walking ability. DHS is characterized by weakness of the neck extensors and a consecutive inability to extend the neck; in severe cases the head is fixed in a ''chin to chest position.'' Many diseases may underlie these conditions, and there have been some reports about radiation-induced camptocormia and DHS. A PubMed search with the keywords ''camptocormia,'' ''dropped head syndrome,'' ''radiation-induced myopathy,'' ''radiation-induced neuropathy,'' and ''radiation-induced movement disorder'' was carried out to better characterize radiation-induced movement disorders and the radiation techniques involved. In addition, the case of a patient developing camptocormia 23 years after radiation therapy of a non-Hodgkin's lymphoma of the abdomen is described. In total, nine case series of radiation-induced DHS (n = 45 patients) and - including our case - three case reports (n = 3 patients) about radiogenic camptocormia were retrieved. Most cases (40/45 patients) occurred less than 15 years after radiotherapy involving extended fields for Hodgkin's disease. The use of wide radiation fields including many spinal segments with paraspinal muscles may lead to radiation-induced movement disorders. If paraspinal muscles and the thoracolumbar spine are involved, the clinical presentation can be that of camptocormia. DHS may result if there is involvement of the cervical spine. To prevent these disorders, sparing of the spine and paraspinal muscles is desirable. (orig.) [German] In den letzten Jahren haben Bewegungsstoerungen von Wirbelsaeule und paraspinaler Muskulatur in

  1. Protective effect of esculentoside A on radiation-induced dermatitis and fibrosis

    International Nuclear Information System (INIS)

    Xiao Zhenyu; Su Ying; Yang Shanmin; Yin Liangjie; Wang Wei; Yi Yanghua; Fenton, Bruce M.; Zhang Lurong; Okunieff, Paul

    2006-01-01

    Purpose: To investigate the effect of esculentoside A (EsA) on radiation-induced cutaneous and fibrovascular toxicity and its possible molecular mechanisms, both in vivo and in vitro. Methods and Materials: Mice received drug intervention 18 hours before 30 Gy to the right hind leg. Alterations in several cytokines expressed in skin tissue 2 days after irradiation were determined by ELISA. Early skin toxicity was evaluated 3 to 4 weeks after irradiation by skin scoring, and both tissue contraction and expression of TGF-β1 were determined for soft-tissue fibrosis 3 months after irradiation. In vitro, the effect of EsA on radiation-induced nitric oxide (NO) and cytokine production in different cell types was measured by application of 2, 4, and 8 Gy. Results: In vivo, EsA reduced levels of IL-1α, MCP-1, VEGF, and TGF-β1 in cutaneous tissue and reduced soft-tissue toxicity. In vitro, EsA inhibited the IL-1α ordinarily produced after 4 Gy in A431 cells. In Raw264.7 cells, EsA reduced levels of IL-1α, IL-1β, and NO production costimulated by radiation and lipopolysaccharide (LPS). In L-929 cells, EsA inhibited VEGF, TNF, and MCP-1 production at 2, 4, and 8 Gy. Conclusions: Esculentoside A protects soft tissues against radiation toxicity through inhibiting the production of several proinflammatory cytokines and inflammatory mediators in epithelial cells, macrophages, fibroblasts, and skin tissue

  2. Radiation-induced circumscribed superficial morphea after brachytherapy for endometrial adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Apoorva Trivedi, BS

    2017-12-01

    Full Text Available Radiation-induced morphea (RIM is a rare and underrecognized complication of radiation therapy that most commonly occurs in women after treatment for breast cancer. Although not fully understood, RIM is hypothesized to arise from an increase in cytokines that stimulate collagen production and extracellular matrix formation. Most documented cases of RIM occur 1 year after radiation therapy and are localized to areas that were treated for breast cancer. We report on a case of a female patient with stage IB endometrial adenocarcinoma who was treated with 24 Gray of adjuvant brachytherapy. The patient developed a diffuse morpheaform, pruritic eruption only at distant sites from the brachytherapy treatment field. Although treatment for RIM is generally unsatisfactory, our patient experienced improvement in the pruritus and a regression of the lesions while applying topical 0.1% tacrolimus ointment and 0.1% triamcinolone creme. An early diagnosis of RIM can prevent extensive workup, guide treatment, and improve quality of life for patients. Keywords: radiation-induced morphea, postirradiation morphea

  3. Use of radiation-induced polymers in cement slurries

    International Nuclear Information System (INIS)

    Knight, B.L.; Rhudy, J.S.; Gogarty, W.B.

    1976-01-01

    Water loss from cement slurries is reduced by incorporating within a cement slurry a polymer obtained as a product of radiation-induced polymerization of acrylamide and/or methacrylamide and acrylic acid, methacrylic acid, and/or alkali metal salts thereof. The polymerization is preferably carried out in 10-60 percent aqueous monomer solution with gamma radiation. The aqueous monomer solution preferably contains 25-99 percent acrylamide and 75-1 percent sodium acrylate. The polymer can be present in concentration of about 0.001 to about 3.0 weight percent, based on the aqueous phase of the slurry

  4. Radiation processed polysaccharide products

    International Nuclear Information System (INIS)

    Nguyen, Quoc Hien

    2007-01-01

    Radiation crosslinking, degradation and grafting techniques for modification of polymeric materials including natural polysaccharides have been providing many unique products. In this communication, typical products from radiation processed polysaccharides particularly plant growth promoter from alginate, plant protector and elicitor from chitosan, super water absorbent containing starch, hydrogel sheet containing carrageenan/CM-chitosan as burn wound dressing, metal ion adsorbent from partially deacetylated chitin were described. The procedures for producing those above products were also outlined. Future development works on radiation processing of polysaccharides were briefly presented. (author)

  5. Radiation-induced myelopathy

    Energy Technology Data Exchange (ETDEWEB)

    Gaenshirt, H [Heidelberg Univ. (F.R. Germany). Neurologische Klinik

    1975-10-01

    12 cases of radiation-induced myelopathy after /sup 60/Co teletherapy are reported on. Among these were 10 thoracal lesions, one cerviothoracal lesion, and one lesion of the medulla oblongata. In 9 cases, Hodgkin's disease had been the primary disease, tow patients had been irradiated because of suspected vertebral metastases of cancer of the breast, and one patient had suffered from a glomus tumour of the petrous bone. The spinal doses had exceeded the tolerance doses recommended in the relevant literature. There was no close correlation between the radiation dose and the course of the disease. The latency periods between the end of the radiotherapy and the onset of the neurological symptons varied from 6 to 16 mouths and were very constant in 7 cases with 6 to 9 months. The segmental height of the lesion corresponded to the level of irradiation. The presenting symptons of radiation-induced myelopathy are buruing dysaesthesias and Brown-Sequard's paralysis which may develop into transverse lesion of the cord with paraplegia still accompanied by dissociated perception disorders. The disease developed intermittently. Disturbances of the bladder function are frequent. The fluid is normal in most cases. Myelographic examinations were made in 8 cases. 3 cases developed into stationary cases exhibiting. Brown-Sequard syndrome, while 9 patients developed transverse lesion of the cord with paraplegia. 3 patients have died; antopsy findings are given for two of these. In the pathogenesis of radiation-induced myelopathy, the vascular factor is assumed to be of decisive importance.

  6. GSK-3β Inhibition Attenuates LPS-Induced Death but Aggravates Radiation-Induced Death via Down-Regulation of IL-6

    Directory of Open Access Journals (Sweden)

    Bailong Li

    2013-12-01

    Full Text Available Background: Exposure of high dose ionizing radiation is lethal. Signal pathways involved in radiation biology reaction still remain illdefined. Lipopolysaccharides (LPS, the ligands of Toll-like receptor 4(TLR4, could elicit strong immune responses. Glycogen synthase kinase-3β(GSK-3β promotes the production of inflammatory molecules and cell migration. Inhibition of GSK-3β provides protection against inflammation in animal models. The aim of the study was to investigate role of GSK-3β in LPS shock and ionizing radiation. Methods: WT or IL-6-/-mice or cells were pretreated with SB216763, a GSK-3β inhibitor, and survival of the mice was determined. Cell viability was assayed by Cell Counting Kit. Apoptosis was assayed by Annexin V-PI double staining. Serum concentrations of IL-6 and TNF-α were determined by ELISA. Results: SB216763 attenuated LPS induced mice or cell death but aggravated radiation induced mice or cell death. SB216763 reduced IL-6, but not TNF-α levels in vivo. IL-6-/- mice were more resistant to LPS-induced death but less resistant to radiation-induced death than wild type mice. Conclusions: Inhibition of GSK-3β conferred resistance to LPS shock but fostered death induced by ionizing radiation. Inhibition of GSK-3β was effective by reducing IL-6.

  7. Radiation induced effects in the developing central nervous system

    International Nuclear Information System (INIS)

    Gisone, P.; Dubner, D.; Michelin, S.C.; Perez, M.R. Del

    1997-01-01

    The embryo and the human foetus are particularly sensitive to ionizing radiation and this sensitivity presents various qualitative and quantitative functional changes during intra-uterine development. Apart from radiation induced carcinogenesis, the most serious consequence of prenatal exposure in human beings is severe mental retardation. The principal data on radiation effects on human beings in the development of the central nervous system come form epidemiological studies carried out in individuals exposed in utero during the atomic explosion at Hiroshima and Nagasaki. These observations demonstrate the existence of a time of maximum radiosensitivity between the weeks 8 and 15 of the gestational period, a period in which the proliferation and neuronal migration takes place. Determination of the characteristics of dose-response relationship and the possible existence of a threshold dose of radiation effects on the development of the central nervous system is relevant to radiation protection against low dose radiation and the establishment of dose limits for occupational exposure and the public. Studies were conducted on the generation of nitrous-oxide and its relation with the production of active species of oxygen in brains of exposed rats in utero exposed to doses of up to 1 Gy during their maximum radiosensitivity. The possible role of the mechanism of radiation induced damage in the development of the central nervous system is discussed

  8. Bystander effects in UV-induced genomic instability: Antioxidants inhibit delayed mutagenesis induced by ultraviolet A and B radiation

    Directory of Open Access Journals (Sweden)

    Dahle Jostein

    2005-01-01

    Full Text Available Abstract Background Genomic instability is characteristic of many types of human cancer. Recently, we reported that ultraviolet radiation induced elevated mutation rates and chromosomal instability for many cell generations after ultraviolet irradiation. The increased mutation rates of unstable cells may allow them to accumulate aberrations that subsequently lead to cancer. Ultraviolet A radiation, which primarily acts by oxidative stress, and ultraviolet B radiation, which initially acts by absorption in DNA and direct damage to DNA, both produced genomically unstable cell clones. In this study, we have determined the effect of antioxidants on induction of delayed mutations by ultraviolet radiation. Delayed mutations are indicative of genomic instability. Methods Delayed mutations in the hypoxanthine phosphoribosyl transferase (hprt gene were detected by incubating the cells in medium selectively killing hprt mutants for 8 days after irradiation, followed by a 5 day period in normal medium before determining mutation frequencies. Results The UVB-induced delayed hprt mutations were strongly inhibited by the antioxidants catalase, reduced glutathione and superoxide dismutase, while only reduced glutathione had a significant effect on UVA-induced delayed mutations. Treatment with antioxidants had only minor effects on early mutation frequenies, except that reduced glutathione decreased the UVB-induced early mutation frequency by 24 %. Incubation with reduced glutathione was shown to significantly increase the intracellular amount of reduced glutathione. Conclusion The strong effects of these antioxidants indicate that genomic instability, which is induced by the fundamentally different ultraviolet A and ultraviolet B radiation, is mediated by reactive oxygen species, including hydrogen peroxide and downstream products. However, cells take up neither catalase nor SOD, while incubation with glutathione resulted in increased intracellular levels of

  9. Radiation-induced polymerization and radiation effect on polymers

    International Nuclear Information System (INIS)

    Seguchi, Tadao

    1977-12-01

    The processes of radiation-induced polymerization of monomers and also radiation effects on polymers have been studied by instrumental analyses of electron spin resonance (ESR), nuclear magnetic resonance (NMR) and electron microscopy. In radiation-induced polymerization, graft-copolymerization and absorbed state polymerization were taken up. For graft-copolymerization, monomers such as methylmethacrylate and butadiene were made to react with irradiated polyethylene, and behaviors of the initiating radicals and propagating radicals were followed under the reaction by ESR. For absorbed state polymerization, acrylonitrile/zeolite and methylmethacrylate/zeolite were chosen. Absorbed monomers were irradiated at 77 0 K and polymerized at room temperature. Active species and the concentrations were measured by ESR and the yields of polymer were observed by NMR. In radiation effect on polymers, polyvinylfluoride, polyvinylidenfluoride and polytetrafluoroethylene were taken up. Active species trapped in the polymer matrixes were identified and decay and reactivity of the species were also studied. On the basis of information from the electron microscopy and x-ray analysis, radiation effects on these polymers are described. In polytetrafluoroethylene produced by radiation polymerization, the relation between morphology and polymerization conditions and also the process of crystallization during polymerization were studied. (auth.)

  10. Study on radiation-inducible genes

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sang Yong; Kim, Dong Ho; Joe, Min Ho; Park, Hae Jun; Song, Hyu Npa

    2012-01-15

    Radiation-inducible genes of E. coli, which is a model strain for bacterial study, and Salmonella, which is a typical strain for pathogenic bacteria were compared through omic analysis. Heat shock response genes and prophage genes were induced by radiation in Salmonella, not in E. coli. Among prophage genes tested, STM2628 showed the highest activation by radiation, and approximately 1 kb promoter region was turned out to be necessary for radiation response. To screen an artificial promoter showing activation by 2 Gy, the high-throughput screening method using fluorescent MUG substrate was established. The use of bacteria as anticancer agents has attracted interest. In this study, we tried to develop tumor targeting bacteria in which the radiation-inducible promoter activate a transgene encoding a cytotoxic protein. To do this, a tumor-targeting hfq Salmonella mutant strain was constructed, and we found that its virulence decreased. For outward secretion of anticancer protein produced inside bacteria, the signal peptide of SspH1 was determined and the signal peptide was proven to be able to secrete an anticancer protein. Tumor xenograft mouse model was secured, which can be used for efficiency evaluation of bacterial tumor therapy.

  11. Study on radiation-inducible genes

    International Nuclear Information System (INIS)

    Lim, Sang Yong; Kim, Dong Ho; Joe, Min Ho; Park, Hae Jun; Song, Hyu Npa

    2012-01-01

    Radiation-inducible genes of E. coli, which is a model strain for bacterial study, and Salmonella, which is a typical strain for pathogenic bacteria were compared through omic analysis. Heat shock response genes and prophage genes were induced by radiation in Salmonella, not in E. coli. Among prophage genes tested, STM2628 showed the highest activation by radiation, and approximately 1 kb promoter region was turned out to be necessary for radiation response. To screen an artificial promoter showing activation by 2 Gy, the high-throughput screening method using fluorescent MUG substrate was established. The use of bacteria as anticancer agents has attracted interest. In this study, we tried to develop tumor targeting bacteria in which the radiation-inducible promoter activate a transgene encoding a cytotoxic protein. To do this, a tumor-targeting hfq Salmonella mutant strain was constructed, and we found that its virulence decreased. For outward secretion of anticancer protein produced inside bacteria, the signal peptide of SspH1 was determined and the signal peptide was proven to be able to secrete an anticancer protein. Tumor xenograft mouse model was secured, which can be used for efficiency evaluation of bacterial tumor therapy

  12. Radiation-induced cancers in man

    International Nuclear Information System (INIS)

    Hirose, Fumio

    1978-01-01

    Radiation-induced cancers in man were divided into three groups, a group in which cancers occurred after atomic bomb exposure, a group in which cancers occurred in radiologists and other medical specialists, and a group in which cancers occurred after exposure to diagnostic radiation, and they were summarized. In atomic bomb survivors leukemia, thyroid cancer, salivary gland cancer, lung cancer, and breast cancer occurred so frequently. In addition to them, mortality ratios by malignant lymphoma, stomach cancer, esophageal cancer, and by cancer of urinary tract were increased. The incidence of leukemia was decreased in those who treated radiation owing to the development of the protection of occupational exposure, and the incidence of radiation-induced cancers was decreased in patients owing to the improvement of therapy. However, a new problem has arisen as to the occurrence of cancers after medical exposure, such as various histological types of cancers after the treatment of skin diseases on the head, and breast cancer after the treatment of pneumothorax. Dose-to-effect relation, hereditary factors, effect of age, immunological influences and endocrine actions were also studied in each radiation-induced cancer. (Ichikawa, K.)

  13. Radiation-induced cancers in man

    Energy Technology Data Exchange (ETDEWEB)

    Hirose, F [Hiroshima Univ. (Japan). Research Inst. for Nuclear Medicine and Biology

    1978-07-01

    Radiation-induced cancers in man were divided into three groups, a group in which cancers occurred after atomic bomb exposure, a group in which cancers occurred in radiologists and other medical specialists, and a group in which cancers occurred after exposure to diagnostic radiation, and they were summarized. In atomic bomb survivors leukemia, thyroid cancer, salivary gland cancer, lung cancer, and breast cancer occurred so frequently. In addition to them, mortality ratios by malignant lymphoma, stomach cancer, esophageal cancer, and by cancer of urinary tract were increased. The incidence of leukemia was decreased in those who treated radiation owing to the development of the protection of occupational exposure, and the incidence of radiation-induced cancers was decreased in patients owing to the improvement of therapy. However, a new problem has arisen as to the occurrence of cancers after medical exposure, such as various histological types of cancers after the treatment of skin diseases on the head, and breast cancer after the treatment of pneumothorax. Dose-to-effect relation, hereditary factors, effect of age, immunological influences and endocrine actions were also studied in each radiation-induced cancer.

  14. Radiation-induced brain injury: A review

    Directory of Open Access Journals (Sweden)

    Michael eRobbins

    2012-07-01

    Full Text Available Approximately 100,000 primary and metastatic brain tumor patients/year in the US survive long enough (> 6 months to experience radiation-induced brain injury. Prior to 1970, the human brain was thought to be highly radioresistant; the acute CNS syndrome occurs after single doses > 30 Gy; white matter necrosis occurs at fractionated doses > 60 Gy. Although white matter necrosis is uncommon with modern techniques, functional deficits, including progressive impairments in memory, attention, and executive function have become important, because they have profound effects on quality of life. Preclinical studies have provided valuable insights into the pathogenesis of radiation-induced cognitive impairment. Given its central role in memory and neurogenesis, the majority of these studies have focused on the hippocampus. Irradiating pediatric and young adult rodent brains leads to several hippocampal changes including neuroinflammation and a marked reduction in neurogenesis. These data have been interpreted to suggest that shielding the hippocampus will prevent clinical radiation-induced cognitive impairment. However, this interpretation may be overly simplistic. Studies using older rodents, that more closely match the adult human brain tumor population, indicate that, unlike pediatric and young adult rats, older rats fail to show a radiation-induced decrease in neurogenesis or a loss of mature neurons. Nevertheless, older rats still exhibit cognitive impairment. This occurs in the absence of demyelination and/or white matter necrosis similar to what is observed clinically, suggesting that more subtle molecular, cellular and/or microanatomic modifications are involved in this radiation-induced brain injury. Given that radiation-induced cognitive impairment likely reflects damage to both hippocampal- and non-hippocampal-dependent domains, there is a critical need to investigate the microanatomic and functional effects of radiation in various brain

  15. Ionizing radiation induced malignancies in man

    International Nuclear Information System (INIS)

    Dutrillaux, B.

    1997-01-01

    Using data on gene and chromosome alterations in human cancers, it is proposed that most radiation induced cancers are a consequence of recessive mutations of tumor suppressor genes. This explains the long delay between radiation exposure and the cancer onset. As a consequence, radiation induced cancers belong to groups of tumors where no specific translocations (forming or activating oncogenes) but multiple unbalanced chromosome rearrangements (deletions unmasking recessive mutations) exist. This explains why osteosarcomas, malignant fibrous histiocytoma, chondrosarcomas are frequently induced, but not liposarcoma, Ewing sarcomas and rhabdomyosarcomas, among others. A single exception confirms this rule: papillary thyroid cancer, frequently induced in exposed children, in which structural rearrangements frequently form a RET/PTC3 fusion gene. This fusion gene is the results of the inversion of a short segment of chromosome 10, and it is assumed that such rearrangement (small para-centric inversion) can easily occur after exposure to radiations, at contrast with translocations between to genes belonging to different chromosomes. (author)

  16. The effects of radioprotective agents on the radiation-induced DNA single strand breaks

    International Nuclear Information System (INIS)

    Rhiu, Sung Ryul; Ko, Kyung Hwan; Jung, In Yong; Cho, Chul Ku; Kim, Tae Hwan; Park, Woo Wiun; Kim, Sung Ho; Ji, Young Hoon; Kim, Kyung Jung; Bang, Hio Chang; Jung, Young Suk; Choi, Moon Sik

    1992-04-01

    With the increased use of atomic energy in science, industry, medicine and public power production, the probability of nuclear accidents certainly appears to be on the increase. Therefore, early medical diagnosis and first-aid are needed urgently to establish an efficient treatment. We carried out the studies of radiation protector such as DDC, MEA, WR-2721 and variety of decontaminator with a view to establishing the protective measure and diagnostic standards for safety of worker and neighbors living around the radiation area in case of occurring the accidental contamination. In this experiment, we examined radiation-induced DNA single strand breaks as one of the study on molecular biology of the response of cells to radiation because an understanding of the radiation-induced damage in molecular level would add to our knowledge of radiation protection and treatment. (Author)

  17. Three cases of radiation-induced cancer in oral regions

    International Nuclear Information System (INIS)

    Kawamura, Hiroshi; Shinoki, Kunihiko; Endo, Yoshitaka; Fujita, Yasushi; Hayashi, Susumu

    1985-01-01

    Three cases of radiation-induced cancer in the oral regions were reported with relation to radiation therapy. One was the general radiation-induced cancer following radiotherapy for the hemangioma. The other two cases, which belonged in the B-1 group of Sakai and his coworker's diagnostic criteria for radiation-induced cancer, were those occurring after radiotherapy for the malignant tumors. Due to the relatively high dosage exposure by the patient in the radiotherapy it is necessary to look out the latency of the radiation-induced cancer. After radiotherapy, careful and periodical observation is important for immediate treatment in an early stage for the radiation-induced cancer to have a favorable prognosis. In addition careful observation of the changes after radiotherapy helps in discovering the precancerous lesions from the therapy. For the radiation-induced cancer, surgical treatment would be the best, however, radiation therapy is also effective in certain cases. (author)

  18. Vanguards of paradigm shift in radiation biology. Radiation-induced adaptive and bystander responses

    International Nuclear Information System (INIS)

    Matsumoto, Hideki; Hamada, Nobuyuki; Kobayashi, Yasuhiko; Takahashi, Akihisa; Ohnishi, Takeo

    2007-01-01

    The risks of exposure to low dose ionizing radiation (below 100 mSv) are estimated by extrapolating from data obtained after exposure to high dose radiation, using a linear no-threshold model (LNT model). However, the validity of using this dose-response model is controversial because evidence accumulated over the past decade has indicated that living organisms, including humans, respond differently to low dose/low dose-rate radiation than they do to high dose/high dose-rate radiation. In other words, there are accumulated findings which cannot be explained by the classical ''target theory'' of radiation biology. The radioadaptive response, radiation-induced bystander effects, low-dose radio-hypersensitivity, and genomic instability are specifically observed in response to low dose/low dose-rate radiation, and the mechanisms underlying these responses often involve biochemical/molecular signals that respond to targeted and non-targeted events. Recently, correlations between the radioadaptive and bystander responses have been increasingly reported. The present review focuses on the latter two phenomena by summarizing observations supporting their existence, and discussing the linkage between them from the aspect of production of reactive oxygen and nitrogen species. (author)

  19. The nature and principles of the radiation-induced cancerogenesis

    International Nuclear Information System (INIS)

    Lips'ka, A.YI.; Serkyiz, Ya.Yi.

    2004-01-01

    The paper represents the analysis of the authors and literary data concerning the nature and principles of the radiation-induced neoplasms. The mechanisms of the radiation-induced cancerogenesis development are not clear understood. The experimental data altogether do not allow developing the mathematical model of the radiation-induced cancerogenesis at the molecular level. This model has to take into account all necessary indices including radiation factor and the state of the organism. The general principles of the radiation-induced cancerogenesis have been formulated in the present review. It is possible to use these principles in order to predict and calculate the risks of the radiation-induced neoplasms

  20. Radiation-induced linking reactions in polyethylene

    International Nuclear Information System (INIS)

    Zoepfl, F.J.

    1983-01-01

    Three types of measurements are reported relating to chemical reactions in polyethylene induced by ionizing radiation: 1) viscometric and low-angle laser light scattering measurements to determine the effect of a radical scavenger on the yield of links; 2) calorimetric measurements to determine the effect of radiation-induced linking on the melting behavior of polyethylene; and 3) high-resolution solution carbon 13 nuclear magnetic resonance (NMR) spectrometry measurements to determine the nature of the links and the method of their formation. The NMR results present the first direct detection of radiation-induced long-chain branching (Y links) in polyethylene, and place an apparent upper limit on the yield of H-shaped crosslinks that are formed when polyethylene is irradiated to low absorbed doses. The effect of radiation-induced linking on the melting behavior of polyethylene was examined using differential scanning calorimetry (DSC). It was found that radiation-induced links do not change the heat of fusion of polythylene crystals, but decrease the melt entropy and increase the fold surface free energy per unit area of the crystals. The carbon 13 NMR results demonstrate that long-chain branches (Y links) are formed much more frequently than H-shaped crosslinks at low absorbed doses. The Y links are produced by reactions of alkyl free radicals with terminal vinyl groups in polyethylene

  1. 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.)

  2. Mechanisms of radiation-induced normal tissue toxicity and implications for future clinical trials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Ho; Jenrow, Kenneth A.; Brown, Stephen L. [Dept.of Radiation Oncology, Henry Ford Health System, Detroit (United States)

    2014-09-15

    To summarize current knowledge regarding mechanisms of radiation-induced normal tissue injury and medical countermeasures available to reduce its severity. Advances in radiation delivery using megavoltage and intensity-modulated radiation therapy have permitted delivery of higher doses of radiation to well-defined tumor target tissues. Injury to critical normal tissues and organs, however, poses substantial risks in the curative treatment of cancers, especially when radiation is administered in combination with chemotherapy. The principal pathogenesis is initiated by depletion of tissue stem cells and progenitor cells and damage to vascular endothelial microvessels. Emerging concepts of radiation-induced normal tissue toxicity suggest that the recovery and repopulation of stromal stem cells remain chronically impaired by long-lived free radicals, reactive oxygen species, and pro-inflammatory cytokines/chemokines resulting in progressive damage after radiation exposure. Better understanding the mechanisms mediating interactions among excessive generation of reactive oxygen species, production of pro-inflammatory cytokines and activated macrophages, and role of bone marrow-derived progenitor and stem cells may provide novel insight on the pathogenesis of radiation-induced injury of tissues. Further understanding the molecular signaling pathways of cytokines and chemokines would reveal novel targets for protecting or mitigating radiation injury of tissues and organs.

  3. Mechanisms of radiation-induced normal tissue toxicity and implications for future clinical trials

    International Nuclear Information System (INIS)

    Kim, Jae Ho; Jenrow, Kenneth A.; Brown, Stephen L.

    2014-01-01

    To summarize current knowledge regarding mechanisms of radiation-induced normal tissue injury and medical countermeasures available to reduce its severity. Advances in radiation delivery using megavoltage and intensity-modulated radiation therapy have permitted delivery of higher doses of radiation to well-defined tumor target tissues. Injury to critical normal tissues and organs, however, poses substantial risks in the curative treatment of cancers, especially when radiation is administered in combination with chemotherapy. The principal pathogenesis is initiated by depletion of tissue stem cells and progenitor cells and damage to vascular endothelial microvessels. Emerging concepts of radiation-induced normal tissue toxicity suggest that the recovery and repopulation of stromal stem cells remain chronically impaired by long-lived free radicals, reactive oxygen species, and pro-inflammatory cytokines/chemokines resulting in progressive damage after radiation exposure. Better understanding the mechanisms mediating interactions among excessive generation of reactive oxygen species, production of pro-inflammatory cytokines and activated macrophages, and role of bone marrow-derived progenitor and stem cells may provide novel insight on the pathogenesis of radiation-induced injury of tissues. Further understanding the molecular signaling pathways of cytokines and chemokines would reveal novel targets for protecting or mitigating radiation injury of tissues and organs.

  4. Determination of proton-induced production cross sections and production rates of {sup 129}I from Te

    Energy Technology Data Exchange (ETDEWEB)

    Schnabel, C.; Lopez-Guitierrez, J.M.; Suter, M. [Eidgenoessische Technische Hochschule, Zurich (Switzerland); Synal, H.A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Gloris, M.; Leya, I.; Michel, R. [Hannover Univ. (Germany); Herpers, U. [Koeln Univ. (Germany)

    1997-09-01

    In order to model the production of {sup 129}I in meteoroids, proton-induced production cross sections in the medium range of {sup 129}I from Te as well as production from meteoroid simulation experiments have been determined. {sup 129}I is a very important cosmogenic nuclide to study the constancy of cosmic radiation on long time scales. (author) 2 figs., 2 refs.

  5. Radiation-induced segregation in Cu-Au alloys

    International Nuclear Information System (INIS)

    Hashimoto, T.; Rehn, L.E.; Okamoto, P.R.

    1987-01-01

    Radiation-induced segregation in a Cu-lat.% Au alloy was investigated using in-situ Rutherford backscattering spectrometry. Irradiation with 1.8-MeV helium produced nonequilibrium gold atom depletion in the near surface region. The amount of segregation was measured as a function of dose, dose rate, and temperature. Segregation was observed in the temperature range between about 300 and 500 0 C. For a calculated dose rate of 3.9 x 10/sup -5/ dpa/s, the radiation-induced segregation rate peaked near 400 0 C. Theoretical analysis based on the Johnson-Lam model predicted that the amount of segregation would be directly proportional to dose at the early stage of irradiation, would deviate from linearity with a continuously decreasing slope of intermediate doses, and finally approach a constant value after high doses. The analysis also predicted that the segregation rate would vary as the - 1/4th power of the dose rate at constant dose in the low temperature region. These predictions were all verified experimentally. A procedure for extracting relative defect production efficiencies from similar measurements is discussed

  6. Does occupational exposure to ionizing radiation induce adaptation

    International Nuclear Information System (INIS)

    Djurovic, B.; Selakovic, V.; Radjen, S.; Radakovic, S.; Spasic-Jokic, V.

    2008-01-01

    Full text: Even the most of personnel occupationally exposed (OE) to ionizing radiation (IR) is exposed to very low doses (LD), some harmful effects can be noticed. IR can affect the cell structure in two ways: directly and indirectly-inducing radiolysis of water and production of reactive oxygen species (ROS) similar to endogenously induced. In the low- LET exposure almost 70 % of absorbed energy is spent for ROS production. Over-production of ROS can cause oxidative stress. DNA is the main target of induced ROS. It is also experimentally showed that many important cell protective mechanisms, such is adaptation, are dependent of ROS concentration produced by low doses. The aim of this paper is to investigate if occupational exposure to LD induce over-production of ROS, and influence the activity of protective enzymes and radiosensitivity as well as induce adaptation. Our subjects were medical workers occupationally exposed to IR (44) and not-exposed (33), matched in gender, age, habits-dietary, alcohol consumption, smoking. Occupational exposure was calculated on the basis of individual TL-dose records. Besides the standard medical examination, micronucleus test, superoxide production and lipid peroxidation index, expressed as malonaldehyde (MDA) production, were performed by standard procedures as well as measurements of activity of the superoxide dismutase (SOD) and glutathione (GSH). Half of each sample were put in a sterile plastic test-tube placed in a plexiglas container 15 x 15 cm, and irradiated by 60 Co source of γ-ray at room temperature. Employed radiation dose was 2 Gy, dose-rate 0.45 Gy/min and distance from the source 74 cm. All blood samples were frozen at -70 C degrees, and kept till analyses which were performed at the same time. Our results confirm: significantly higher incidence of micronuclei in OE (.31±10 vs 17±8, p=0.00) with significant increase after irradiation in each group and lack of differences in radiosensitivity between groups

  7. Disinfestation of agricultural products with electron beams and their radiation tolerance

    International Nuclear Information System (INIS)

    Hayashi, Toru

    1996-01-01

    Some agricultural products contaminated with insect pests are fumigated with methyl bromide for quarantine purposes. However, the use of methyl bromide is preferably restricted because of its ozone depleting effect. Therefore, establishing alternative quarantine techniques is highly desirable; one such technique is exposure to ionizing radiation. Few data are available on the effects of radiation on insect pests other than fruit flies and stored-product insects and on the radiation tolerance of host commodities. Radiation technology as an alternative to methyl bromide fumigation will be used to inactivate not only insects but also mites, spider mites, thrips, nematodes, scales, mealybugs and thrips contaminating fruits, grains, cut flowers, vegetables, timbers, seedlings and seeds. In order to collect data on the effects of irradiation on pests and host commodities, IAEA and FAO have conducted an international project, 'FAO/IAEA Coordinated Research Programme on Irradiation as a Quarantine Treatment of Mites, Nematodes and Insects other than Fruit Fly' since 1992. The project determines the minimum doses necessary to inactivate pests and the maximum doses host commodities tolerate. All pests except nematodes can be inactivated at doses 400Gy or lower. Various varieties of cut flowers and herbs are tolerant to 400Gy of radiation, although some flowers and herbs such as chrysanthemum, rose, lily, calla, anthurium, sweet pea, iris, dill, basil and arugula are intolerant to 200Gy of radiation. Japanese research project on treatment of cut flowers with electron beams carried out mainly by Yokohama Plant Protection Station greatly contributes to these conclusions. Aqueous solution (2%) of sucrose, glucose, fructose or maltose prevents radiation-induced detrimental effects of radiation on chrysanthemums. Sugars reduce radiation-induced physiological deterioration of chrysanthemums. (author)

  8. Mutation effects of kojic acid production strain induced by synchrotron radiation of soft X-rays and kinetics of the fermentation

    International Nuclear Information System (INIS)

    Chen Liang; Jiang Shiping; Wan Libiao; Ma Xiaodong; Li Meifang

    2006-01-01

    The irradiation effect on Aspergillus oryzae spores was studied by 0.54 keV X-rays (about the K shell absorption edge of oxygen) from the synchrotron facility at NSRL. A high production mutant for kojic acid was obtained from the spores irradiated by soft X-rays, which accumulated 27.79 g kojic acid per L in 500 mL shake-flask fermentation for 10 days using glucose as carbon source, and has increased about 56% of production than that of the original (17.81 g/L). Also the fermentation conditions were studied with different carbon sources and nitrogen sources. The results showed that the mutant induced by the X-rays of synchrotron radiation would be of potential for high kojic acid production. (authors)

  9. Regulation of radiation-induced apoptosis by early growth response-1 gene in solid tumors

    International Nuclear Information System (INIS)

    Ahmed, M.

    2003-01-01

    Ionizing radiation exposure is associated with activation of certain immediate-early genes that function as transcription factors. These include members of jun or fos and early growth response (EGR) gene families. In particular, the functional role of EGR-1 in radiation-induced signaling is pivotal since the promoter of EGR-1 contains radiation-inducible CArG DNA sequences. The Egr-1 gene belongs to a family of Egr genes that includes EGR-2, EGR-3, EGR-4, EGR-α and the tumor suppressor, Wilms' tumor gene product, WT1. The Egr-1 gene product, EGR-1, is a nuclear protein that contains three zinc fingers of the C 2 H 2 subtype. The EGR-1 GC-rich consensus target sequence, 5'-GCGT/GGGGCG-3' or 5'-TCCT/ACCTCCTCC-3', has been identified in the promoter regions of transcription factors, growth factors, receptors, cell cycle regulators and pro-apoptotic genes. The gene targets mediated by Egr-1 in response to ionizing radiation include TNF-α , p53, Rb and Bax, all these are effectors of apoptosis. Based on these targets, Egr-1 is a pivotal gene that initiates early signal transduction events in response to ionizing radiation leading to either growth arrest or cell death in tumor cells. There are two potential application of Egr-1 gene in therapy of cancer. First, the Egr-1 promoter contains information for appropriate spatial and temporal expression in-vivo that can be regulated by ionizing radiation to control transcription of genes that have pro-apoptotic and suicidal function. Secondly, EGR-1 protein can eliminate 'induced-radiation resistance' by inhibiting the functions of radiation-induced pro-survival genes (NFκB activity and bcl-2 expression) and activate pro-apoptotic genes (such as bax) to confer a significant radio-sensitizing effect. Together, the reported findings from my laboratory demonstrate clearly that EGR-1 is an early central gene that confers radiation sensitivity and its pro-apoptotic functions are synergized by abrogation of induced radiation

  10. Radiation-induced brain injury: A review

    Energy Technology Data Exchange (ETDEWEB)

    Greene-Schloesser, Dana; Robbins, Mike E.; Peiffer, Ann M.; Shaw, Edward G. [Department of Radiation Oncology, Wake Forest School of Medicine,, Winston-Salem, NC (United States); Brain Tumor Center of Excellence, Wake Forest School of Medicine,, Winston-Salem, NC (United States); Wheeler, Kenneth T. [Brain Tumor Center of Excellence, Wake Forest School of Medicine,, Winston-Salem, NC (United States); Department of Radiology, Wake Forest School of Medicine,, Winston-Salem, NC (United States); Chan, Michael D., E-mail: mrobbins@wakehealth.edu [Department of Radiation Oncology, Wake Forest School of Medicine,, Winston-Salem, NC (United States); Brain Tumor Center of Excellence, Wake Forest School of Medicine,, Winston-Salem, NC (United States)

    2012-07-19

    Approximately 100,000 primary and metastatic brain tumor patients/year in the US survive long enough (>6 months) to experience radiation-induced brain injury. Prior to 1970, the human brain was thought to be highly radioresistant; the acute CNS syndrome occurs after single doses >30 Gy; white matter necrosis occurs at fractionated doses >60 Gy. Although white matter necrosis is uncommon with modern techniques, functional deficits, including progressive impairments in memory, attention, and executive function have become important, because they have profound effects on quality of life. Preclinical studies have provided valuable insights into the pathogenesis of radiation-induced cognitive impairment. Given its central role in memory and neurogenesis, the majority of these studies have focused on the hippocampus. Irradiating pediatric and young adult rodent brains leads to several hippocampal changes including neuroinflammation and a marked reduction in neurogenesis. These data have been interpreted to suggest that shielding the hippocampus will prevent clinical radiation-induced cognitive impairment. However, this interpretation may be overly simplistic. Studies using older rodents, that more closely match the adult human brain tumor population, indicate that, unlike pediatric and young adult rats, older rats fail to show a radiation-induced decrease in neurogenesis or a loss of mature neurons. Nevertheless, older rats still exhibit cognitive impairment. This occurs in the absence of demyelination and/or white matter necrosis similar to what is observed clinically, suggesting that more subtle molecular, cellular and/or microanatomic modifications are involved in this radiation-induced brain injury. Given that radiation-induced cognitive impairment likely reflects damage to both hippocampal- and non-hippocampal-dependent domains, there is a critical need to investigate the microanatomic and functional effects of radiation in various brain regions as well as their

  11. Radiation-induced brain injury: A review

    International Nuclear Information System (INIS)

    Greene-Schloesser, Dana; Robbins, Mike E.; Peiffer, Ann M.; Shaw, Edward G.; Wheeler, Kenneth T.; Chan, Michael D.

    2012-01-01

    Approximately 100,000 primary and metastatic brain tumor patients/year in the US survive long enough (>6 months) to experience radiation-induced brain injury. Prior to 1970, the human brain was thought to be highly radioresistant; the acute CNS syndrome occurs after single doses >30 Gy; white matter necrosis occurs at fractionated doses >60 Gy. Although white matter necrosis is uncommon with modern techniques, functional deficits, including progressive impairments in memory, attention, and executive function have become important, because they have profound effects on quality of life. Preclinical studies have provided valuable insights into the pathogenesis of radiation-induced cognitive impairment. Given its central role in memory and neurogenesis, the majority of these studies have focused on the hippocampus. Irradiating pediatric and young adult rodent brains leads to several hippocampal changes including neuroinflammation and a marked reduction in neurogenesis. These data have been interpreted to suggest that shielding the hippocampus will prevent clinical radiation-induced cognitive impairment. However, this interpretation may be overly simplistic. Studies using older rodents, that more closely match the adult human brain tumor population, indicate that, unlike pediatric and young adult rats, older rats fail to show a radiation-induced decrease in neurogenesis or a loss of mature neurons. Nevertheless, older rats still exhibit cognitive impairment. This occurs in the absence of demyelination and/or white matter necrosis similar to what is observed clinically, suggesting that more subtle molecular, cellular and/or microanatomic modifications are involved in this radiation-induced brain injury. Given that radiation-induced cognitive impairment likely reflects damage to both hippocampal- and non-hippocampal-dependent domains, there is a critical need to investigate the microanatomic and functional effects of radiation in various brain regions as well as their

  12. Delayed Radiation-Induced Vasculitic Leukoencephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, Philipp J. [Departments of Pathology and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut (United States); Faculty of Medicine, University of Heidelberg, Heidelberg (Germany); Park, Henry S. [Departments of Pathology and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut (United States); Knisely, Jonathan P.S. [Department of Radiation Medicine, North Shore University Hospital, Manhasset, New York (United States); Chiang, Veronica L. [Departments of Pathology and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut (United States); Vortmeyer, Alexander O., E-mail: alexander.vortmeyer@yale.edu [Departments of Pathology and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut (United States)

    2012-05-01

    Purpose: Recently, single-fraction, high-dosed focused radiation therapy such as that administered by Gamma Knife radiosurgery has been used increasingly for the treatment of metastatic brain cancer. Radiation therapy to the brain can cause delayed leukoencephalopathy, which carries its own significant morbidity and mortality. While radiosurgery-induced leukoencephalopathy is known to be clinically different from that following fractionated radiation, pathological differences are not well characterized. In this study, we aimed to integrate novel radiographic and histopathologic observations to gain a conceptual understanding of radiosurgery-induced leukoencephalopathy. Methods and Materials: We examined resected tissues of 10 patients treated at Yale New Haven Hospital between January 1, 2009, and June 30, 2010, for brain metastases that had been previously treated with Gamma Knife radiosurgery, who subsequently required surgical management of a symptomatic regrowing lesion. None of the patients showed pathological evidence of tumor recurrence. Clinical and magnetic resonance imaging data for each of the 10 patients were then studied retrospectively. Results: We provide evidence to show that radiosurgery-induced leukoencephalopathy may present as an advancing process that extends beyond the original high-dose radiation field. Neuropathologic examination of the resected tissue revealed traditionally known leukoencephalopathic changes including demyelination, coagulation necrosis, and vascular sclerosis. Unexpectedly, small and medium-sized vessels revealed transmural T-cell infiltration indicative of active vasculitis. Conclusions: We propose that the presence of a vasculitic component in association with radiation-induced leukoencephalopathy may facilitate the progressive nature of the condition. It may also explain the resemblance of delayed leukoencephalopathy with recurring tumor on virtually all imaging modalities used for posttreatment follow-up.

  13. Computer modelling of radiation-induced bystander effect

    International Nuclear Information System (INIS)

    Khvostunov, Igor K.; Nikjoo, Hooshang

    2002-01-01

    Radiation-induced genomic instability and bystander effects are now well established consequences of exposure of living cells to ionising radiation. It has been observed that cells not directly hit by radiation tracks may still exhibit radiation effects. We present a quantitative modelling of the radiation-induced bystander effect based on a diffusion model of spreading the bystander signal. The model assumes the bystander factor to be a protein of low molecular weight, given out by the hit cell, diffusing in the medium and reacting with non-hit cells. The model calculations successfully predict the results of cell survival in an irradiated conditioned medium. The model predicts the shape of dose-effect relationship for cell survival and oncogenic transformation induced by broad-beam and micro-beam irradiation by alpha-particles. (author)

  14. Formation of radiation-induced defects and their influence on tritium extraction from lithium silicates in out-of-pile experiments

    International Nuclear Information System (INIS)

    Abramenkovs, A.A.; Tiliks, J.E.

    1991-01-01

    Formation and properties of radiation-induced defects and radiolysis products in lithium silicates irradiated in nuclear reactor till absorbed doses 1000 MGy were studied. Radiation-induced defects (RD) and radiolysis products (RP) were qualitatively and quantitatively determinated by methods of chemical scavengers (MHS), electron-spin resonance (ESR) and optical spectroscopy. Colloidal silicon and lithium, lithium and silicon oxides, oxygen, silicon and lithium peroxides are the final products of the lithium silicates radiolysis at absorbed energy doses D abs = 1000 MGy. The concentration of radiation defects and products of radiolysis strongly depend on the temperature of irradiation, humidity, granural size. The thermostimulated extraction of tritiated water (95-98% of the released tritium is in chemical form of water) from lithium silicates ceramics proceeds according to two independent mechanisms: a) chemidesorption of surface localized tritiated water (the first order chemical reaction); b) formation of the tritium water molecules limited by triton diffusion to the near-surface layer of grains. It has been found that the concentration of radiation-induced defects considerably affects the tritium localization and releasing processes from lithium silicates. (orig.)

  15. Study on production of useful metabolites by development of advanced cell culture techniques using radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Byung Yeoup; Kim, Jinhong; Lee, Seung Sik; Bai, Hyounwoo; An, Byung Chull; Lee, Eun Mi; Lee, Jae Taek; Kim, Mi Ja

    2010-12-15

    The purpose of this project is improvement of investigation, materialization and evaluation techniques on effectiveness for functional natural compounds throughout development of tissue/cell culture techniques for mass production of useful metabolites using radiation. Research scope includes Development of a technique for radiation tissue and cell culture, Database construction for radiation response in plants and radiation effects, Construction of general-purpose national based techniques of cell culture technique using radiation. Main results are as follow: Isolation and identification of radiation induced basI gene; Determination of stresses sensitivities by transformating basI gene into arabidopsis; Isolation and identification of radiation induced chaperon proteins (PaAhpC and yPrxII) from Pseudomonas and yeast, and structural and functional analysis of the proteins; Determination of oxidative and heat resistance by transformating PaAhpC; Isolation and identification of maysin and its derivatives from centipedgrass; Investigation of enhancement technique for improving maysin and its derivatives production using radiation; Investigation of removing undesirable color in maysin and its derivatives using radiation; Determination of the effect of radiation on physiological functions of centipedgrass extracts; Identification of H{sub 2}O{sub 2} removing enzyme in radiation irradiated plant (Spinach); Determination of the effects of centipedgrass extracts on anti-obesity and anti-cancer activities.

  16. Study on production of useful metabolites by development of advanced cell culture techniques using radiation

    International Nuclear Information System (INIS)

    Chung, Byung Yeoup; Kim, Jinhong; Lee, Seung Sik; Bai, Hyounwoo; An, Byung Chull; Lee, Eun Mi; Lee, Jae Taek; Kim, Mi Ja

    2010-12-01

    The purpose of this project is improvement of investigation, materialization and evaluation techniques on effectiveness for functional natural compounds throughout development of tissue/cell culture techniques for mass production of useful metabolites using radiation. Research scope includes Development of a technique for radiation tissue and cell culture, Database construction for radiation response in plants and radiation effects, Construction of general-purpose national based techniques of cell culture technique using radiation. Main results are as follow: Isolation and identification of radiation induced basI gene; Determination of stresses sensitivities by transformating basI gene into arabidopsis; Isolation and identification of radiation induced chaperon proteins (PaAhpC and yPrxII) from Pseudomonas and yeast, and structural and functional analysis of the proteins; Determination of oxidative and heat resistance by transformating PaAhpC; Isolation and identification of maysin and its derivatives from centipedgrass; Investigation of enhancement technique for improving maysin and its derivatives production using radiation; Investigation of removing undesirable color in maysin and its derivatives using radiation; Determination of the effect of radiation on physiological functions of centipedgrass extracts; Identification of H 2 O 2 removing enzyme in radiation irradiated plant (Spinach); Determination of the effects of centipedgrass extracts on anti-obesity and anti-cancer activities

  17. Radiation-induced chromosomal instability

    International Nuclear Information System (INIS)

    Ritter, S.

    1999-01-01

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

  18. Ionizing radiation-induced metabolic oxidative stress and prolonged cell injury

    Science.gov (United States)

    Azzam, Edouard I.; Jay-Gerin, Jean-Paul; Pain, Debkumar

    2013-01-01

    Cellular exposure to ionizing radiation leads to oxidizing events that alter atomic structure through direct interactions of radiation with target macromolecules or via products of water radiolysis. Further, the oxidative damage may spread from the targeted to neighboring, non-targeted bystander cells through redox-modulated intercellular communication mechanisms. To cope with the induced stress and the changes in the redox environment, organisms elicit transient responses at the molecular, cellular and tissue levels to counteract toxic effects of radiation. Metabolic pathways are induced during and shortly after the exposure. Depending on radiation dose, dose-rate and quality, these protective mechanisms may or may not be sufficient to cope with the stress. When the harmful effects exceed those of homeostatic biochemical processes, induced biological changes persist and may be propagated to progeny cells. Physiological levels of reactive oxygen and nitrogen species play critical roles in many cellular functions. In irradiated cells, levels of these reactive species may be increased due to perturbations in oxidative metabolism and chronic inflammatory responses, thereby contributing to the long-term effects of exposure to ionizing radiation on genomic stability. Here, in addition to immediate biological effects of water radiolysis on DNA damage, we also discuss the role of mitochondria in the delayed outcomes of ionization radiation. Defects in mitochondrial functions lead to accelerated aging and numerous pathological conditions. Different types of radiation vary in their linear energy transfer (LET) properties, and we discuss their effects on various aspects of mitochondrial physiology. These include short and long-term in vitro and in vivo effects on mitochondrial DNA, mitochondrial protein import and metabolic and antioxidant enzymes. PMID:22182453

  19. Role of neurotensin in radiation-induced hypothermia in rats

    International Nuclear Information System (INIS)

    Kandasamy, S.B.; Hunt, W.A.; Harris, A.H.

    1991-01-01

    The role of neurotensin in radiation-induced hypothermia was examined. Intracerebroventricular (ICV) administration of neurotensin produced dose-dependent hypothermia. Histamine appears to mediate neurotensin-induced hypothermia because the mast cell stabilizer disodium cromoglycate and antihistamines blocked the hypothermic effects of neurotensin. An ICV pretreatment with neurotensin antibody attenuated neurotensin-induced hypothermia, but did not attenuate radiation-induced hypothermia, suggesting that radiation-induced hypothermia was not mediated by neurotensin

  20. Relationship between radiation induced activation of DNA repair genes and radiation induced apoptosis in human cell line A431

    International Nuclear Information System (INIS)

    Bom, Hee Seung; Min, Jung Jun; Kim, Kyung Keun; Choi, Keun Hee

    2000-01-01

    The purpose of this study was to evaluate the relationship between radiation-induced acivation of DNA repair genes and radiation induced apoptosis in A431 cell line. Five and 25 Gys of gamma radiation were given to A431 cells by a Cs-137 cell irradiator. Apoptosis was evaluated by flow cytometry using annexin V-fluorescein isothiocyanate and propidium iodide staining. The expression of DNA repair genes was evaluated by both Northern and Western blot analyses. The number of apoptotic cells increased with the increased radiation dose. It increased most significantly at 12 hours after irradiation. Expression of p53, p21, and ℎRAD50 reached the highest level at 12 hours after 5 Gy irradiation. In response to 25 Gy irradiation, ℎRAD50 and p21 were expressed maximally at 12 hours, but p53 and GADD45 genes showed the highest expression level after 12 hours. Induction of apoptosis and DNA repair by ionizing radiation were closely correlated. The peak time of inducing apoptosis and DNA repair was 12 hours in this study model. ℎRAD50, a recently discovered DNA repair gene, was also associated with radiation-induced apoptosis.=20

  1. The relevance of cytokines in the radiation-induced lung reaction. Experimental basis and clinical significance

    International Nuclear Information System (INIS)

    Ruebe, C.E.; Ruebe, C.; Rodemann, H.P.

    2004-01-01

    Methods: published data on radiation-induced cytokine expression from experimental and clinical studies are reviewed. Results and conclusion: the major pro-inflammatory cytokines in the radiation response of the lung include tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1), and interleukin-6 (IL-6). Transforming growth factor-β (TGF-β) appears to be of particular importance in the development of lung fibrosis. First approaches with radioprotective agents and gene therapy to modify radiation-induced cytokine expression have been investigated for prevention of late effects of irradiation lung damage in animal experiments. Preliminary data of clinical studies suggest that elevated plasma TGF-β-levels during radiotherapy may predict the development of symptomatic radiation pneumonitis. The biological impacts of endogenous radiation-induced cytokine production by tumor cells in respect of tumor behavior, potential damage to normal tissue, and clinical status of the host still need to be determined more precisely. (orig.)

  2. Study on radiation-inducible genes

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sang Yong; Kim, Dong Ho; Joe, Min Ho; Song, Hyu Npa

    2012-01-15

    Transcription of previously identified radiation-inducible genes, uscA and cyoA, was examined responding to radiation. The putative promoter regions of both genes were cloned into pRS415 vector containing lacZ, and the core promoter region necessary for radiation response were determined through promoter deletion method. To investigate the role of uscA, which is assumed to be small RNA related with radiation response, a deletion mutant strain of uscA was constructed. However, uscA deletion did not affect bacterial survival against radiation exposure. The use of bacteria as anticancer agents has attracted interest. In this study, we tried to develop tumor targeting bacteria in which the radiation-inducible promoter activate a transgene encoding a cytotoxic protein. For outward secretion of anticancer protein produced inside bacteria, the N-terminal 140 amino acid of SspH1 was found to function as a secretion signal peptide. To create an attenuated tumor-targeting bacteria, Salmonella ptsI mutant strain was constructed, and we found that its virulence decreased. Finally, the tumor-targeting ability of ptsI mutant was verified by the use of in-vivo imaging analysis.

  3. Study on radiation-inducible genes

    International Nuclear Information System (INIS)

    Lim, Sang Yong; Kim, Dong Ho; Joe, Min Ho; Song, Hyu Npa

    2012-01-01

    Transcription of previously identified radiation-inducible genes, uscA and cyoA, was examined responding to radiation. The putative promoter regions of both genes were cloned into pRS415 vector containing lacZ, and the core promoter region necessary for radiation response were determined through promoter deletion method. To investigate the role of uscA, which is assumed to be small RNA related with radiation response, a deletion mutant strain of uscA was constructed. However, uscA deletion did not affect bacterial survival against radiation exposure. The use of bacteria as anticancer agents has attracted interest. In this study, we tried to develop tumor targeting bacteria in which the radiation-inducible promoter activate a transgene encoding a cytotoxic protein. For outward secretion of anticancer protein produced inside bacteria, the N-terminal 140 amino acid of SspH1 was found to function as a secretion signal peptide. To create an attenuated tumor-targeting bacteria, Salmonella ptsI mutant strain was constructed, and we found that its virulence decreased. Finally, the tumor-targeting ability of ptsI mutant was verified by the use of in-vivo imaging analysis

  4. Role of endothelium in radiation-induced normal tissue damages

    International Nuclear Information System (INIS)

    Milliat, F.

    2007-05-01

    More than half of cancers are treated with radiation therapy alone or in combination with surgery and/or chemotherapy. The goal of radiation therapy is to deliver enough ionising radiation to destroy cancer cells without exceeding the level that the surrounding healthy cells can tolerate. Unfortunately, radiation-induced normal tissue injury is still a dose limiting factor in the treatment of cancer with radiotherapy. The knowledge of normal tissue radiobiology is needed to determine molecular mechanisms involved in normal tissue pathogenic pathways in order to identify therapeutic targets and develop strategies to prevent and /or reduce side effects of radiation therapy. The endothelium is known to play a critical role in radiation-induced injury. Our work shows that endothelial cells promote vascular smooth muscle cell proliferation, migration and fibro-genic phenotype after irradiation. Moreover, we demonstrate for the first time the importance of PAI-1 in radiation-induced normal tissue damage suggesting that PAI-1 may represent a molecular target to limit injury following radiotherapy. We describe a new role for the TGF-b/Smad pathway in the pathogenesis of radiation-induced damages. TGF-b/Smad pathway is involved in the fibro-genic phenotype of VSMC induced by irradiated EC as well as in the radiation-induced PAI-1 expression in endothelial cells. (author)

  5. Radiation Induced Crosslinking of Polyethylene in the Presence of Bifunctional Vinyl Monomers

    DEFF Research Database (Denmark)

    Joshi, M. S.; Singer, Klaus Albert Julius; Silverman, J.

    1977-01-01

    Several reports have been published showing that the radiation induced grafting of bifunctional vinyl monomers to low density polyethylene results in a product with an unusually high density of crosslinks. The same grafting reactions are shown to reduce the incipient gel dose by more than a factor...... of fifty. This paper is concerned with the apparent crosslinking produced by the radiation grafting of two monomers to polyethylene: acrylic acid and acrylonitrile....

  6. Radiation sterilization of medical products

    International Nuclear Information System (INIS)

    Khurshid, S.J.; Hussain, A.M.

    1989-01-01

    Radiation sterilization is the best method of sterilization, essentially for single use medical and surgical products. Pakistan has established a commercial gamma irradiation plant for this purpose. This article overviews the advantages and benefits of radiation sterilization to stimulate the interest of industrialists and the users in this technology. This technology can give a better medical care in the country and the growing demand can only be met by bulk sterilization. The radiation sterilized medical products can also compete well with the products sterilized by other methods in the international market, gamma sterilization is accepted internationally and if adopted it can boost our export of medical products. (author)

  7. Heavy-ion radiation induced bystander effect in mice

    Science.gov (United States)

    Liang, Shujian; Sun, Yeqing; Zhang, Meng; Wang, Wei; Cui, Changna

    2012-07-01

    Radiation-induced bystander effect is defined as the induction of damage in neighboring non-hit cells by signals released from directly-irradiated cells. Recently, Low dose of high LET radiation induced bystander effects in vivo have been reported more and more. It has been indicated that radiation induced bystander effect was localized not only in bystander tissues but also in distant organs. Genomic, epigenetic, metabolomics and proteomics play significant roles in regulating heavy-ion radiation stress responses in mice. To identify the molecular mechanism that underlies bystander effects of heavy-ion radiation, the male mice head were exposed to 2000mGy dose of 12C heavy-ion radiation and the distant organ liver was detected on 1h, 6h, 12h and 24h after radiation, respectively. MSAP was used to monitor the level of polymorphic DNA methylation changes. The results show that heavy-ion irradiate mouse head can induce liver DNA methylation changes significantly. The percent of DNA methylation changes are time-dependent and highest at 6h after radiation. We also prove that the hypo-methylation changes on 1h and 6h after irradiation. But the expression level of DNA methyltransferase DNMT3a is not changed. UPLC/Synapt HDMS G2 was employed to detect the proteomics of bystander liver 1h after irradiation. 64 proteins are found significantly different between treatment and control group. GO process show that six of 64 which were unique in irradiation group are associated with apoptosis and DNA damage response. The results suggest that mice head exposed to heavy-ion radiation can induce damage and methylation pattern changed in distant organ liver. Moreover, our findings are important to understand the molecular mechanism of radiation induced bystander effects in vivo.

  8. A study of radiation-induced cerebral vascular injury in nasopharyngeal carcinoma patients with radiation-induced temporal lobe necrosis.

    Directory of Open Access Journals (Sweden)

    Jianhong Ye

    Full Text Available To investigate radiation-induced carotid and cerebral vascular injury and its relationship with radiation-induced temporal lobe necrosis in nasopharyngeal carcinoma (NPC patients.Fifty eight NPC patients with radiation-induced temporal lobe necrosis (TLN were recruited in the study. Duplex ultrasonography was used to scan bilateral carotid arterials to evaluate the intima-media thickness (IMT and occurrence of plaque formation. Flow velocities of bilateral middle cerebral arteries (MCAs, internal carotid arteries (ICAs and basal artery (BA were estimated through Transcranial Color Doppler (TCD. The results were compared with data from 33 patients who were free from radiation-induced temporal lobe necrosis after radiotherapy and 29 healthy individuals.Significant differences in IMT, occurrence of plaques of ICAs and flow velocities of both MCAs and ICAs were found between patients after radiotherapy and healthy individuals (p<0.05. IMT had positive correlation with post radiation interval (p = 0.049. Compared with results from patients without radiation-induced TLN, the mean IMT was significantly thicker in patients with TLN (p<0.001. Plaques were more common in patients with TLN than patients without TLN (p = 0.038. In addition, flow velocities of MCAs and ICAs in patients with TLN were much faster (p<0.001, p<0.001. Among patients with unilateral TLN, flow velocity of MCAs was significantly different between ipsilateral and contralateral sides to the lesion (p = 0.001.Thickening of IMT, occurrence of plaque formation and hemodynamic abnormality are more common in patients after radiotherapy, especially in those with TLN, compared with healthy individuals.

  9. Radiation-induced genomic instability and bystander effects: inter-related inflammatory-type non-targeted effects of exposure to ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Wright, E.G. (Molecular and Cellular Pathology Laboratories, Division of Pathology and Neuroscience, Ninewells Hospital and Medical School, Dundee, Scotland (United Kingdom))

    2008-12-15

    The dogma that genetic alterations are restricted to directly irradiated cells has been challenged by observations in which effects of ionizing radiation, characteristically associated with the consequences of energy deposition in the cell nucleus, arise in non-irradiated cells. These, so called, untargeted effects are demonstrated in cells that are the descendants of irradiated cells (radiation-induced genomic instability) or in cells that have communicated with neighbouring irradiated cells (radiation-induced bystander effects). There are also reports of long-range signals in vivo, known as clastogenic factors, with the capacity to induce damage in unirradiated cells. Clastogenic factors may be related to the inflammatory responses that have been implicated in some of the pathological consequences of radiation exposures. The phenotypic expression of untargeted effects reflects a balance between the type of signals produced and the responses of cell populations to such signals, both of which may be significantly influenced by cell type and genotype. There is accumulating evidence that untargeted effects in vitro involve inter-cellular signalling, production of cytokines and free radical generation. These are also features of inflammatory responses in vivo that are known to have the potential for both bystander-mediated and persisting damage as well as for conferring a predisposition to malignancy. At present it is far from clear how untargeted effects contribute to overall cellular radiation responses and in vivo consequences but it is possible that the various untargeted effects may reflect inter-related aspects of a non-specific inflammatory-type response to radiation-induced stress and injury and be involved in a variety of the pathological consequences of radiation exposures. (orig.)

  10. Radiation-induced genomic instability and bystander effects: inter-related inflammatory-type non-targeted effects of exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Wright, E.G.

    2008-01-01

    The dogma that genetic alterations are restricted to directly irradiated cells has been challenged by observations in which effects of ionizing radiation, characteristically associated with the consequences of energy deposition in the cell nucleus, arise in non-irradiated cells. These, so called, untargeted effects are demonstrated in cells that are the descendants of irradiated cells (radiation-induced genomic instability) or in cells that have communicated with neighbouring irradiated cells (radiation-induced bystander effects). There are also reports of long-range signals in vivo, known as clastogenic factors, with the capacity to induce damage in unirradiated cells. Clastogenic factors may be related to the inflammatory responses that have been implicated in some of the pathological consequences of radiation exposures. The phenotypic expression of untargeted effects reflects a balance between the type of signals produced and the responses of cell populations to such signals, both of which may be significantly influenced by cell type and genotype. There is accumulating evidence that untargeted effects in vitro involve inter-cellular signalling, production of cytokines and free radical generation. These are also features of inflammatory responses in vivo that are known to have the potential for both bystander-mediated and persisting damage as well as for conferring a predisposition to malignancy. At present it is far from clear how untargeted effects contribute to overall cellular radiation responses and in vivo consequences but it is possible that the various untargeted effects may reflect inter-related aspects of a non-specific inflammatory-type response to radiation-induced stress and injury and be involved in a variety of the pathological consequences of radiation exposures. (orig.)

  11. Radiation-induced heart injury. Radiopathological study

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Y; Niibe, H [Gunma Univ., Maebashi (Japan). School of Medicine

    1975-11-01

    In order to identify radiation-induced heart injury and to differentiate it from heart disease, an attempt was made to clarify post-irradiation heart injury by investigating the histological changes which occur during the interval between the irradiation and the time of demonstrable histological changes. A study was made of 83 autopsies in which most of the primary neoplasms were breast cancers, lung cancers and mediastinal tumors. In 43 of these autopsies the heart had been irradiated. Sixty eight dd-strain mice were also used for microautoradiographic study. Histological changes in the heart were observed in 27 of the 43 cases receiving irradiation. The limit of the tolerance dose to the heart for indicating histological changes was 1220 ret in humans. The latent period without histological changes was 2.7 months after initiation of radiation therapy. Greater heart injury was observed after re-irradiation or after the combined therapy of radiation and chemotherapy especially mitomycin (MMC). The histological findings after treatment with MMC were similar to those of radiation-induced heart injury. Results of the study indicate that the damage is secondary to radiation-induced changes of the vascula connective tissue.

  12. Effect of radiation on the long term productivity of a plant based CELSS

    International Nuclear Information System (INIS)

    Thompson, B.G.; Lake, B.H.

    1987-01-01

    Mutations occur at a higher rate in space than under terrestrial conditions, primarily due to an increase in radiation levels. These mutations may effect the productivity of plants found in a controlled ecological life support system (CELSS). Computer simulations of plants with different ploidies, modes of reproduction, lethality thresholds, viability thresholds and susceptibilities to radiation induced mutations were performed under space normal and solar flare conditions. These simulations identified plant characteristics that would enable plants to retain high productivities over time in a CELSS

  13. Radiation-induced degradation of pollutants

    International Nuclear Information System (INIS)

    Proksch, E.

    1988-01-01

    This article outlines the fundamentals of radiation-induced degradation of noxious substances in drinking water and waste water and discusses the relevant literature. Radiation methods present a number of advantages and disadvantages, which should carefully be considered in each case. In many cases, there seems to be merit in combining the radiation method with other techniques, as e.g. ozone treatement and biodegradation. 30 refs., 3 figs. (Author)

  14. Basic molecular biology in radiation-induced carcinogenesis

    International Nuclear Information System (INIS)

    Rytoemaa, T.

    1992-01-01

    The tumour suppressor gene p53 is 'guardian of the genome'. If a DNA molecule (each chromosome has one DNA molecule) is damaged by an external factor, such as ionizing radiation, the protein product of the p53 gene stops the cell's proliferative activity until the damage is repaired. If the repair fails, the p53 gene product normally triggers programmed death of the cell. P53 gene itself is commonly damaged by radiation (or by another DNA-damaging factor). The altered gene product fails to control the integrity of the genome, and it also prevents the guardian action of the protein which is produced by the intact allele (each cell has two p53 genes). Under these circumstances any subsequent damage to DNA, induced e.g. by a chemical, is easily 'fixed'. Potentially critical sites for an additional DNA damage are the proto-oncogens (when damaged these genes are called oncogens), which commonly act as components of the regulatory network in a cell. Permanent malfunction of the signal network may then lead to uncontrolled cell growth, resulting in a malignant clone (=cancer). This simplified molecular model seems to be the common mechanism in many (or most) human cancers. (orig.)

  15. Pyruvate metabolism: A therapeutic opportunity in radiation-induced skin injury

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Hyun; Kang, Jeong Wook [Department of Radiation Oncology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Lee, Dong Won [Department of Plastic Surgery, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Oh, Sang Ho [Department of Dermatology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Lee, Yun-Sil [College of Pharmacy & Division of Life and Pharmaceutical Sciences, Ewah Womans University, Seoul 120-750 (Korea, Republic of); Lee, Eun-Jung [Department of Radiation Oncology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Cho, Jaeho, E-mail: jjhmd@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of)

    2015-05-08

    Ionizing radiation is used to treat a range of cancers. Despite recent technological progress, radiation therapy can damage the skin at the administration site. The specific molecular mechanisms involved in this effect have not been fully characterized. In this study, the effects of pyruvate, on radiation-induced skin injury were investigated, including the role of the pyruvate dehydrogenase kinase 2 (PDK2) signaling pathway. Next generation sequencing (NGS) identified a wide range of gene expression differences between the control and irradiated mice, including reduced expression of PDK2. This was confirmed using Q-PCR. Cell culture studies demonstrated that PDK2 overexpression and a high cellular pyruvate concentration inhibited radiation-induced cytokine expression. Immunohistochemical studies demonstrated radiation-induced skin thickening and gene expression changes. Oral pyruvate treatment markedly downregulated radiation-induced changes in skin thickness and inflammatory cytokine expression. These findings indicated that regulation of the pyruvate metabolic pathway could provide an effective approach to the control of radiation-induced skin damage. - Highlights: • The effects of radiation on skin thickness in mice. • Next generation sequencing revealed that radiation inhibited pyruvate dehydrogenase kinase 2 expression. • PDK2 inhibited irradiation-induced cytokine gene expression. • Oral pyruvate treatment markedly downregulated radiation-induced changes in skin thickness.

  16. Processing of oil products using complex radiation-thermal treatment and radiation oxonolysis

    International Nuclear Information System (INIS)

    Zaikin, Yu.A.; Zaikina, R.F.

    2002-01-01

    Most of industrial radiation facilities afford an opportunity to produce a considerable amount of reactive ozone-containing gaseous mixtures parallel to the basic production that causes no detriment to the output of the main designed product. The synergetic action of the ozone-containing mixtures and ionizing radiation is of a special interest for industrial application since it can be efficiently used in a wide range of technologies, in particular, for stimulation of chemical conversion in hydrocarbons accompanied by intensive oxidizing processes. In this paper the effect of simultaneous radiation-thermal processing and radiation oxonolysis on hydrocarbon chemical conversion, and subsequent alterations in composition and properties of oil products were studied on the example of high-viscous oil (Karazhanbas field, Kazakhstan) subjected to irradiation by 2 MeV electrons combined with radiation ozonization in the bubbling mode. It was stated that application of the bubbling mode for radiation-induced ozonization of high-viscous oil leads to decrease in the yields of engine fuels in average by 8-10 % compared with those obtained in the conditions when radiation-thermal cracking was applied without bubbling. In the latter case mean yields of the wide gas-oil fraction with boiling start temperature of 350 deg. C, that included gasoline, kerosene, and diesel fuel, were about 76-80 %. Decrease in the gasoline yields does not lead to noticeable alterations in hydrocarbon contents of the gasoline fraction (boiling beginning bellow 175 deg. C) compared with gasoline produced be radiation-thermal cracking, in both cases it meets requirements for high quality standards. However, essential difference was observed in properties of heavy residua of oil processing (oil fractions with T boil >350 deg. C), i.e. the fractions that contained high concentrations of asphaltenes and pitches. Application of radiation oxonolysis diminishes concentrations of high-molecular aromatic

  17. Genetic modification to induce CXCR2 overexpression in mesenchymal stem cells enhances treatment benefits in radiation-induced oral mucositis.

    Science.gov (United States)

    Shen, Zongshan; Wang, Jiancheng; Huang, Qiting; Shi, Yue; Wei, Zhewei; Zhang, Xiaoran; Qiu, Yuan; Zhang, Min; Wang, Yi; Qin, Wei; Huang, Shuheng; Huang, Yinong; Liu, Xin; Xia, Kai; Zhang, Xinchun; Lin, Zhengmei

    2018-02-14

    Radiation-induced oral mucositis affects patient quality of life and reduces tolerance to cancer therapy. Unfortunately, traditional treatments are insufficient for the treatment of mucositis and might elicit severe side effects. Due to their immunomodulatory and anti-inflammatory properties, the transplantation of mesenchymal stem cells (MSCs) is a potential therapeutic strategy for mucositis. However, systemically infused MSCs rarely reach inflamed sites, impacting their clinical efficacy. Previous studies have demonstrated that chemokine axes play an important role in MSC targeting. By systematically evaluating the expression patterns of chemokines in radiation/chemical-induced oral mucositis, we found that CXCL2 was highly expressed, whereas cultured MSCs negligibly express the CXCL2 receptor CXCR2. Thus, we explored the potential therapeutic benefits of the transplantation of CXCR 2 -overexpressing MSCs (MSCs CXCR2 ) for mucositis treatment. Indeed, MSCs CXCR2 exhibited enhanced targeting ability to the inflamed mucosa in radiation/chemical-induced oral mucositis mouse models. Furthermore, we found that MSC CXCR2 transplantation accelerated ulcer healing by suppressing the production of pro-inflammatory chemokines and radiogenic reactive oxygen species (ROS). Altogether, these findings indicate that CXCR2 overexpression in MSCs accelerates ulcer healing, providing new insights into cell-based therapy for radiation/chemical-induced oral mucositis.

  18. The effects of herbs on the radiation-induced apoptosis in intestinal crypt cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Ho; An, Mi Ra; Nah, Seung Yeol; Lee, Jong Hwan; Kim, Jae Ha; Shin, Dong Ho [Chonnam National Univ., Gwangju (Korea, Republic of); Jo, Sung Kee [KAERI, Daejeon (Korea, Republic of); Jang, Jong Sik [Sangju National Univ., Sangju (Korea, Republic of)

    2001-03-15

    This study was performed to determine the effect of several herbs on radiation-induced apoptosis in jejunal crypt cells. Longyanrou(Euphoris logana), Suanzaoren(Zizyphus vulgaris), Yuanzhi(Polygala tenuifolia), Rensan(Panax ginseng), Fuling(Poria cocos), Muxiang(Saussurea lappa), Chuanxiong(Cnidium offcinale), Baishaoyao(Paeonia lactifolia), Shengma(Cimicifuga heracleifolia), Chaihu(Bupleurum falcatum) and Dongchongxiacao(Paecilomyces japonica) reduced the frequency of radiation-induced apoptosis(p<0.05). Although the mechanisms of this effect remain to be elucidated, these results indicated that Longyanrou, Suanzaoren, Yuanzhi, Rensan, Fuling, Muxiang, Chuanxiong, Baishaoyao, Shengma, Chaihu and Dongchongxiacao might be useful inhibitors of apoptosis, especially since these are relative nontoxic natural products.

  19. Protective effects of L-selenomethionine on space radiation induced changes in gene expression.

    Science.gov (United States)

    Stewart, J; Ko, Y-H; Kennedy, A R

    2007-06-01

    Ionizing radiation can produce adverse biological effects in astronauts during space travel. Of particular concern are the types of radiation from highly energetic, heavy, charged particles known as HZE particles. The aims of our studies are to characterize HZE particle radiation induced biological effects and evaluate the effects of L-selenomethionine (SeM) on these adverse biological effects. In this study, microarray technology was used to measure HZE radiation induced changes in gene expression, as well as to evaluate modulation of these changes by SeM. Human thyroid epithelial cells (HTori-3) were irradiated (1 GeV/n iron ions) in the presence or in the absence of 5 microM SeM. At 6 h post-irradiation, all cells were harvested for RNA isolation. Gene Chip U133Av2 from Affymetrix was used for the analysis of gene expression, and ANOVA and EASE were used for a determination of the genes and biological processes whose differential expression is statistically significant. Results of this microarray study indicate that exposure to small doses of radiation from HZE particles, 10 and 20 cGy from iron ions, induces statistically significant differential expression of 196 and 610 genes, respectively. In the presence of SeM, differential expression of 77 out of 196 genes (exposure to 10 cGy) and 336 out of 610 genes (exposure to 20 cGy) is abolished. In the presence or in the absence of SeM, radiation from HZE particles induces differential expression of genes whose products have roles in the induction of G1/S arrest during the mitotic cell cycle, as well as heat shock proteins. Some of the genes, whose expressions were affected by radiation from HZE particles and were unchanged in irradiated cells treated with SeM, have been shown to have altered expression levels in cancer cells. The conclusions of this report are that radiation from HZE particles can induce differential expression of many genes, some of which are known to play roles in the same processes that have

  20. The alteration of chromatin domains during damage repair induced by ionizing radiation

    International Nuclear Information System (INIS)

    Cress, A.E.; Olson, K.M.; Olson, G.B.

    1995-01-01

    Several groups previously have reported the ability of chromatin structure to influence the production of damage induced by ionizing radiation. The authors' interest has been to determine whether chromatin structural alterations exist after ionizing radiation during a repair interval. The earlier work investigated this question using biochemical techniques. The crosslinking of nuclear structural proteins to DNA after ionizing radiation was observed. In addition, they found that the chromatin structure in vitro as measured by sucrose density gradient sedimentation, was altered after ionizing radiation. These observations added to earlier studies in which digital imaging techniques showed an alteration in feulgen-positive DNA after irradiation prompted the present study. The object of this study was to detect whether the higher order structure of DNA into chromatin domains within interphase human cells was altered in interphase cells in response to a radiation induced damage. The present study takes advantage of the advances in the detection of chromatin domains in situ using DNA specific dyes and digital image processing of established human T and B cell lines

  1. 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.

  2. Basic reactions induced by radiation

    International Nuclear Information System (INIS)

    Charlesby, A.

    1980-01-01

    This paper summarises some of the basic reactions resulting from exposure to high energy radiation. In the initial stages energy is absorbed, but not necessarily at random, giving radical and ion species which may then react to promote the final chemical change. However, it is possible to intervene at intermediate stages to modify or reduce the radiation effect. Under certain conditions enhanced reactions are also possible. Several expressions are given to calculate radiation yield in terms of energy absorbed. Some analogies between radiation-induced reactions in polymers, and those studied in radiobiology are outlined. (author)

  3. Radiation-induced desulfurization of Arabian crude oil and straight-run diesel

    Science.gov (United States)

    Basfar, A. A.; Mohamed, K. A.

    2011-11-01

    Radiation-induced desulfurization of four types of Arabian crude oils (heavy, medium, light and extra light) and straight-run diesel (SRD) was investigated over the range of 10-200 kGy. Results show that gamma radiation processing at absorbed doses up to 200 kGy without further treatment is not sufficient for desulfurization. However, the combination of gamma-irradiation with other physical/chemical processes (i.e. L/L extraction, adsorption and oxidation) may be capable of removing considerable levels of sulfur compounds in the investigated products. Currently, this approach of combined radiation/physical/chemical processes is under investigation. The findings of these attempts will be reported in the future.

  4. Radiation-Induced Alopecia after Endovascular Embolization under Fluoroscopy

    Directory of Open Access Journals (Sweden)

    Vipawee Ounsakul

    2016-01-01

    Full Text Available Radiation-induced alopecia after fluoroscopically guided procedures is becoming more common due to an increasing use of endovascular procedures. It is characterized by geometric shapes of nonscarring alopecia related to the area of radiation. We report a case of a 46-year-old man presenting with asymptomatic, sharply demarcated rectangular, nonscarring alopecic patch on the occipital scalp following cerebral angiography with fistula embolization under fluoroscopy. His presentations were compatible with radiation-induced alopecia. Herein, we also report a novel scalp dermoscopic finding of blue-grey dots in a target pattern around yellow dots and follicles, which we detected in the lesion of radiation-induced alopecia.

  5. Radiation-induced neuropathies: collateral damage of improved cancer prognosis

    International Nuclear Information System (INIS)

    Pradat, Pierre-Francois; Maisonobe, Thierry; Psimaras, Dimitri; Lenglet, Timothee; Porcher, Raphael; Lefaix, J.L.; Delenian, S.

    2012-01-01

    Because of the improvement of cancer prognosis, long-term damages of treatments become a medical and public health problem. Among the iatrogenic complications, neurological impairment is crucial to consider since motor disability and pain have a considerable impact on quality of life of long cancer survivors. However, radiation-induced neuropathies have not been the focus of great attention. The objective of this paper is to provide an updated review about the radiation-induced lesions of the peripheral nerve system. Radiation-induced neuropathies are characterized by their heterogeneity in both symptoms and disease course. Signs and symptoms depend on the affected structures of the peripheral nerve system (nerve roots, nerve plexus or nerve trunks). Early-onset complications are often transient and late complications are usually progressive and associated with a poor prognosis. The most frequent and well known is delayed radiation-induced brachial plexopathy, which may follow breast cancer irradiation. Radiation-induced lumbosacral radiculoplexopathy is characterized by pure or predominant lower motor neuron signs. They can be misdiagnosed, confused with amyotrophic lateral sclerosis (ALS) or with leptomeningeal metastases since nodular MRI enhancement of the nerve roots of the cauda equina and increased cerebrospinal fluid protein content can be observed. In the absence of specific markers of the link with radiotherapy, the diagnosis of post-radiation neuropathy may be difficult. Recently, a posteriori conformal radiotherapy with 3D dosimetric reconstitution has been developed to link a precise anatomical site to unexpected excess irradiation. The importance of early diagnosis of radiation-induced neuropathies is underscored by the emergence of new disease-modifying treatments. Although the pathophysiology is not fully understood, it is already possible to target radiation-induced fibrosis but also associated factors such as ischemia, oxidative stress and

  6. Radiation induced mitotic delay and stimulation of growth

    International Nuclear Information System (INIS)

    Feldmann, A.

    1974-01-01

    The mechanisms responsible for the radiation induced mitotic delay and stimulation of growth are discussed in connection with the results of studies in Lemna minor and Lepidium sativum. The action of temperature seems to be of major importance. As many authors suggest that various chemical agents and slight intoxications also affect mitosis in a way similar to that induced by ionizing radiation, the radiation induced stimulation has lost its specific character and approaches might be found for further investigations of this phenomenon. (MG) [de

  7. Radiation-induced apoptosis in F9 teratocarcinoma cells

    International Nuclear Information System (INIS)

    Langley, R.E.; Palayoor, S.T.; Coleman, C.N.; Bump, E.A.

    1994-01-01

    We have found that F9 murine teratocarcinoma cells undergo morphological changes and internucleosomal DNA fragmentation characteristic of apoptosis after exposure to ionizing radiation. We studied the time course, radiation dose-response, and the effects of protein and RNA synthesis inhibitors on this process. The response is dose dependent in the range 2-12 Gy. Internucleosomal DNA fragmentation can be detected as early as 6 h postirradiation and is maximal by 48 h. Cycloheximide, a protein synthesis inhibitor, and 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole, an RNA synthesis inhibitor, both induced internucleosomal DNA fragmentation in the unirradiated cells and enhanced radiation-induced DNA fragmentation. F9 cells can be induced to differentiate into cells resembling endoderm with retinoic acid. After irradiation, differentiated F9 cells exhibit less DNA fragmentation than stem cells. This indicates that ionizing radiation can induce apoptosis in non-lymphoid tumours. We suggest that embryonic tumour cells may be particularly susceptible to agents that induce apoptosis. (Author)

  8. Radiation-induced apoptosis in F9 teratocarcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Langley, R E; Palayoor, S T; Coleman, C N; Bump, E A [Joint Center for Radiation Therapy and Dana Farber Cancer Inst., Boston (United States)

    1994-05-01

    We have found that F9 murine teratocarcinoma cells undergo morphological changes and internucleosomal DNA fragmentation characteristic of apoptosis after exposure to ionizing radiation. We studied the time course, radiation dose-response, and the effects of protein and RNA synthesis inhibitors on this process. The response is dose dependent in the range 2-12 Gy. Internucleosomal DNA fragmentation can be detected as early as 6 h postirradiation and is maximal by 48 h. Cycloheximide, a protein synthesis inhibitor, and 5,6-dichloro-1-[beta]-D-ribofuranosylbenzimidazole, an RNA synthesis inhibitor, both induced internucleosomal DNA fragmentation in the unirradiated cells and enhanced radiation-induced DNA fragmentation. F9 cells can be induced to differentiate into cells resembling endoderm with retinoic acid. After irradiation, differentiated F9 cells exhibit less DNA fragmentation than stem cells. This indicates that ionizing radiation can induce apoptosis in non-lymphoid tumours. We suggest that embryonic tumour cells may be particularly susceptible to agents that induce apoptosis. (Author).

  9. Radiation induced crosslinking of polytetrafluoroethylene

    International Nuclear Information System (INIS)

    Oshima, Akihiro; Tabata, Yoneho; Ikeda, Shigetoshi; Otsuhata, Kazushige; Kudoh, Hisaaki; Seguchi, Tadao.

    1995-01-01

    The Irradiation temperature effect on polytetrafluoroethylene (PTFE) from room temperature to 380degC was investigated by tensile test and thermal analysis. The behavior of tensile properties and changes of crystallinity on irradiation indicated the formation of a network structure in PTFE by radiation induced crosslinking in inert gas in the molten state just above the melting temperature of PTFE (327degC). The crosslinked PTFE showed a much improved radiation resistance in an atmospheric radiation field. (author)

  10. Effect of ozone oxidative preconditioning in preventing early radiation-induced lung injury in rats

    Energy Technology Data Exchange (ETDEWEB)

    Bakkal, B.H. [Department of Radiation Oncology, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey); Gultekin, F.A. [Department of General Surgery, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey); Guven, B. [Department of Biochemistry, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey); Turkcu, U.O. [Mugla School of Health Sciences, Mugla Sitki Kocman University, Mugla (Turkey); Bektas, S. [Department of Pathology, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey); Can, M. [Department of Biochemistry, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey)

    2013-09-27

    Ionizing radiation causes its biological effects mainly through oxidative damage induced by reactive oxygen species. Previous studies showed that ozone oxidative preconditioning attenuated pathophysiological events mediated by reactive oxygen species. As inhalation of ozone induces lung injury, the aim of this study was to examine whether ozone oxidative preconditioning potentiates or attenuates the effects of irradiation on the lung. Rats were subjected to total body irradiation, with or without treatment with ozone oxidative preconditioning (0.72 mg/kg). Serum proinflammatory cytokine levels, oxidative damage markers, and histopathological analysis were compared at 6 and 72 h after total body irradiation. Irradiation significantly increased lung malondialdehyde levels as an end-product of lipoperoxidation. Irradiation also significantly decreased lung superoxide dismutase activity, which is an indicator of the generation of oxidative stress and an early protective response to oxidative damage. Ozone oxidative preconditioning plus irradiation significantly decreased malondialdehyde levels and increased the activity of superoxide dismutase, which might indicate protection of the lung from radiation-induced lung injury. Serum tumor necrosis factor alpha and interleukin-1 beta levels, which increased significantly following total body irradiation, were decreased with ozone oxidative preconditioning. Moreover, ozone oxidative preconditioning was able to ameliorate radiation-induced lung injury assessed by histopathological evaluation. In conclusion, ozone oxidative preconditioning, repeated low-dose intraperitoneal administration of ozone, did not exacerbate radiation-induced lung injury, and, on the contrary, it provided protection against radiation-induced lung damage.

  11. Effect of ozone oxidative preconditioning in preventing early radiation-induced lung injury in rats

    International Nuclear Information System (INIS)

    Bakkal, B.H.; Gultekin, F.A.; Guven, B.; Turkcu, U.O.; Bektas, S.; Can, M.

    2013-01-01

    Ionizing radiation causes its biological effects mainly through oxidative damage induced by reactive oxygen species. Previous studies showed that ozone oxidative preconditioning attenuated pathophysiological events mediated by reactive oxygen species. As inhalation of ozone induces lung injury, the aim of this study was to examine whether ozone oxidative preconditioning potentiates or attenuates the effects of irradiation on the lung. Rats were subjected to total body irradiation, with or without treatment with ozone oxidative preconditioning (0.72 mg/kg). Serum proinflammatory cytokine levels, oxidative damage markers, and histopathological analysis were compared at 6 and 72 h after total body irradiation. Irradiation significantly increased lung malondialdehyde levels as an end-product of lipoperoxidation. Irradiation also significantly decreased lung superoxide dismutase activity, which is an indicator of the generation of oxidative stress and an early protective response to oxidative damage. Ozone oxidative preconditioning plus irradiation significantly decreased malondialdehyde levels and increased the activity of superoxide dismutase, which might indicate protection of the lung from radiation-induced lung injury. Serum tumor necrosis factor alpha and interleukin-1 beta levels, which increased significantly following total body irradiation, were decreased with ozone oxidative preconditioning. Moreover, ozone oxidative preconditioning was able to ameliorate radiation-induced lung injury assessed by histopathological evaluation. In conclusion, ozone oxidative preconditioning, repeated low-dose intraperitoneal administration of ozone, did not exacerbate radiation-induced lung injury, and, on the contrary, it provided protection against radiation-induced lung damage

  12. Study of radiation-induced chromosomal aberrations

    International Nuclear Information System (INIS)

    Wolfring, E.

    2004-06-01

    A method for determining chromosomal aberrations was established for the purpose of examining the relative biological effectiveness (RBE) of photon radiation with respect to mammary epithelium cells. Cells were exposed to 25 kV X-radiation and to 200 kV X-radiation for comparison and the resulting concentrations of chromosomal aberrations were compared. The RBE M value for radiation-induced fragmentation was found to be 4.2 ± 2.4, while the RBE M value for radiation-induced generation of dicentric chromosomes was found to be 0.5 ± 0.5. In addition to the evaluation of chromosomal aberrations the number of cell cycles undergone by the cells was monitored by means of BrDU staining. As expected, the proportion of cells which underwent more than one cell cycle following exposure to 5 Gy was very low in both cases, amounting to 1.9% (25 kV) and 3.2 (200 kV). Non-radiated cells yielded control values of 26.0% and 12.6%, suggesting variations in external conditions from day to day

  13. Control of radiation-induced diarrhea with cholestyramine

    International Nuclear Information System (INIS)

    Heusinkveld, R.S.; Manning, M.R.; Aristizabal, S.A.

    1978-01-01

    Cholestyramine is a non-absorbable ion-exchange resin which specifically binds bile salts. We have treated seven patients with acute or chronic radiation-induced diarrhea that was refractory to the usual methods of control with cholestyramine. In each case, the diarrhea was controlled with cholestyramine. This observation supports previous experimental work with animals which indicated that bile salts contribute to the genesis of radiation-induced diarrhea. Cholestyramine is well-tolerated, but should not be administered with certain oral medications. The results of this small series are preliminary, but point the way toward a more extensive clinical trial to define the usefulness of cholestyramine in the treatment of refractory acute or chronic radiation-induced diarrhea

  14. Involvement of prostaglandins and histamine in radiation-induced temperature responses in rats

    International Nuclear Information System (INIS)

    Kandasamy, S.B.; Hunt, W.A.

    1990-01-01

    Exposure of rats to 1-15 Gy of gamma radiation induced hyperthermia, whereas exposure to 20-150 Gy produced hypothermia. Since radiation exposure induced the release of prostaglandins (PGs) and histamine, the role of PGs and histamine in radiation-induced temperature changes was examined. Radiation-induced hyper- and hypothermia were antagonized by pretreatment with indomethacin, a cyclooxygenase inhibitor. Intracerebroventricular administration of PGE2 and PGD2 induced hyper- and hypothermia, respectively. Administration of SC-19220, a specific PGE2 antagonist, attenuated PGE2- and radiation-induced hyperthermia, but it did not antagonize PGD2- or radiation-induced hypothermia. Consistent with an apparent role of histamine in hypothermia, administration of disodium cromoglycate (a mast cell stabilizer), mepyramine (H1-receptor antagonist), or cimetidine (H2-receptor antagonist) attenuated PGD2- and radiation-induced hypothermia. These results suggest that radiation-induced hyperthermia is mediated via PGE2 and that radiation-induced hypothermia is mediated by another PG, possibly PGD2, via histamine

  15. Molecular epidemiology of radiation-induced carcinogenesis

    International Nuclear Information System (INIS)

    Trosko, J.E.

    1996-01-01

    The role of ionizing radiation in carcinogenesis is discussed. Every cell contains proto-oncogenes, which if damaged may lead to cell transformation. Every cell also contains tumor suppressor genes, which guard against transformation. Thus, transformation would seem to require a double injury to the DNA in a cell. Ionizing radiation is known to be a relatively weak mutagen, but a good clastogen (inducer of chromosome breaks, deletions and rearrangements). Ionizing radiation may therefore be a 'promoter' of cancer, i.e. a stimulant of the clonal expansion of transformed cells, if it kills enough cells to induce compensatory hyperplasia - i.e. rapid growth of cells. Ionizing radiation may be a 'progressor', if it deactivates tumor suppressor genes tending to suppress the growth of existing clones of transformed cells resulting from any of numerous causes. It may therefore be an oversimplification to say that radiation causes cancer; rather, it seems to be a weak initiator, an indirect promoter, and a late-stage progressor. 2 figs

  16. Radiation-induced tumors of the nervous system

    International Nuclear Information System (INIS)

    Bernstein, M.; Laperriere, N.

    1991-01-01

    Therapeutic and nontherapeutic ionizing radiation has long been recognized as a putative carcinogenic agent, but the evidence that radiation causes tumors is circumstantial at worst and statistically significant at best. There are no distinct histological, biochemical, cytogenetic, or clinical criteria that can be used to determine if an individual tumor was caused directly by previous irradiation of the anatomic area. Additional supportive evidence for radiation-induced tumors includes a position correlation between radiation dose and tumor incidence (usually in the low dose range) and experimental induction of the same neoplasm in appropriate animal models. even if these criteria are fulfilled, coincidental development of a second tumor can never be discounted in an individual patient, particularly if there is an underlying diathesis to develop multiple tumors of different histology, such as in Recklinghausen's disease, or if there is an strong family history for the development of neoplastic disease. In this paper, the authors critically evaluate the available evidence to support the hypothesis that radiation induces tumors in the nervous system. The current concepts of radiation carcinogenesis are discussed and are followed by a discussion of animal data and clinical experience in humans. Finally, a brief discussion on treatment of radiation-induced nervous system tumors is presented

  17. [Radiation-induced bystander effect: the important part of ionizing radiation response. Potential clinical implications].

    Science.gov (United States)

    Wideł, Maria; Przybyszewski, Waldemar; Rzeszowska-Wolny, Joanna

    2009-08-18

    It has long been a central radiobiological dogma that the damaging effects of ionizing radiation, such as cell death, cytogenetic changes, apoptosis, mutagenesis, and carcinogenesis, are the results of the direct ionization of cell structures, particularly DNA, or indirect damage via water radiolysis products. However, several years ago attention turned to a third mechanism of radiation, termed the "bystander effect" or "radiation-induced bystander effect" (RIBE). This is induced by agents and signals emitted by directly irradiated cells and manifests as a lowering of survival, cytogenetic damage, apoptosis enhancement, and biochemical changes in neighboring non-irradiated cells. The bystander effect is mainly observed in in vitro experiments using very low doses of alpha particles (range; mGy, cGy), but also after conventional irradiation (X-rays, gamma rays) at low as well as conventional doses. The mechanisms responsible for the bystander effect are complex and still poorly understood. It is believed that molecular signals released from irradiated cells induce different signaling ways in non-irradiated neighboring cells, leading to the observed events. The molecular signals may be transmitted through gap junction intercellular communication and through a medium transfer mechanism. The nature of these transmitted factors are diverse, and still not definitely established. It seems that RIBE may have important clinical implications for health risk associated with radiation exposure. Potentially, this effect may have important implications in the creation of whole-body or localized side effects in tissues beyond the irradiation field and also in low-dose radiological and radioisotope diagnostics. Factors emitted by irradiated cells may result in the risk of genetic instability, mutations, and second primary cancer induction. They might also have their own part in inducing and extending post-radiation side effects in normal tissue. The bystander effect may be a

  18. Radiation-induced bystander effect: The important part of ionizing radiation response. Potential clinical implications

    Directory of Open Access Journals (Sweden)

    Maria Wideł

    2009-08-01

    Full Text Available It has long been a central radiobiological dogma that the damaging effects of ionizing radiation, such as cell death, cytogenetic changes, apoptosis, mutagenesis, and carcinogenesis, are the results of the direct ionization of cell structures, particularly DNA, or indirect damage via water radiolysis products. However, several years ago attention turned to a third mechanism of radiation, termed the “bystander effect” or “radiation-induced bystander effect” (RIBE. This is induced by agents and signals emitted by directly irradiated cells and manifests as a lowering of survival, cytogenetic damage, apoptosis enhancement, and biochemical changes in neighboring non-irradiated cells. The bystander effect is mainly observed in in vitro experiments using very low doses of alpha particles (range; mGy, cGy, but also after conventional irradiation (X-rays, gamma rays at low as well as conventional doses. The mechanisms responsible for the bystander effect are complex and still poorly understood. It is believed that molecular signals released from irradiated cells induce different signaling ways in non-irradiated neighboring cells, leading to the observed events. The molecular signals may be transmitted through gap junction intercellular communication and through a medium transfer mechanism. The nature of these transmitted factors are diverse, and still not defi nitely established. It seems that RIBE may have important clinical implications for health risk associated with radiation exposure. Potentially, this effectmay have important implications in the creation of whole-body or localized side effects in tissues beyond the irradiation fi eld and also in low-dose radiological and radioisotope diagnostics. Factors emitted by irradiated cells may result in the risk of genetic instability, mutations, and second primary cancer induction. They might also have their own part in inducing and extending post-radiation side effects in normal tissue. The

  19. Characterization of radiation-induced Apoptosis in rodent cell lines

    International Nuclear Information System (INIS)

    Guo, Min; Chen, Changhu; Ling, C.C.

    1997-01-01

    For REC:myc(ch1), Rat1 and Rat1:myc b cells, we determined the events in the development of radiation-induced apoptosis to be in the following order: cell division followed by chromatin condensation, membrane blebbing, loss of adhesion and the uptake of vital dye. Experimental data which were obtained using 4 He ions of well defined energies and which compared the dependence of apoptosis and clonogenic survival on 4 He range strongly suggested that in our cells both apoptosis and loss of clonogenic survival resulted from radiation damage to the cell nucleus. Corroboratory evidence was that BrdU incorporation sensitized these cells to radiation-induced apoptosis. Comparing the dose response for apoptosis and the clonogenic survival curves for Rat1 and Rat1:myc b cells, we concluded that radiation-induced cell inactivation as assayed by clonogenic survival, and that a modified linear-quadratic model, proposed previously, modeled such a contribution effectively. In the same context, the selective increase in radiation-induced apoptosis. Comparing the dose response for apoptosis and the clonogenic survival curves for Rat1 and Rat1:myc b cells, we concluded that radiation-induced apoptosis contributed to the overall radiation-induced cell inactivation as assayed by clonogenic survival, and that a modified linear-quadratic model, proposed previously, modeled such a contribution effectively. In the same context, the selective increase in radiation-induced apoptosis during late S and G 2 phases reduced the relative radioresistance observed for clonogenic survival during late S and G 2 phases. 30 refs., 8 figs

  20. Radiation-induced damage of membranes

    International Nuclear Information System (INIS)

    Yonei, Shuji

    1977-01-01

    An outline of membranous structure was stated, and radiation-induced damage of membranes were surveyed. By irradiation, permeability of membranes, especially passive transportation mechanism, was damaged, and glycoprotein in the surface layers of cells and the surface layer structures were changed. The intramembranous damage was induced by decrease of electrophoresis of nuclear mambranes and a quantitative change of cytochrome P450 of microsomal membranes of the liver, and peroxidation of membranous lipid and SH substitute damage of membranous protein were mentioned as the mechanism of membranous damage. Recovery of membranous damage depends on radiation dose and temperature, and membranous damage participates largely in proliferation death. (tsunoda, M.)

  1. Protection against radiation-induced performance decrement in mice

    International Nuclear Information System (INIS)

    Mukherjee, S.K.; Pant, Kanchan; Goel, H.C.; Jain, Viney

    1997-01-01

    Recognizing that there is lack of information on the effects of low-level ionizing radiations and the modifying role of radioprotectors, an attempt has been made in this study to explore the relationship between impairment of spatial learning and low level of radiation exposure. A radial arm maze was utilised to evaluate radiation-induced behavioural alterations and performance decrement in mice. Immediately after whole body exposure to gamma radiation (absorbed dose, 1 Gy) significant perturbations in the learned behaviour of the animals were observed. The regular control movement became irregular and the food consumption time was reduced appreciably (40%). Recovery took place in four days. If diltiazem (7 mg/kg b.w.), a Ca 2+ channel blocker and a radioprotector, was administered i.p. 20-30 min prior to irradiation, radiation-induced behavioural abnormalities were reduced. Mechanisms underlying protection by diltiazem against radiation-induced performance decrement observed in the present study need to be investigated. (author). 23 refs., 2 figs

  2. Radiation-Induced Second Cancer Risk Estimates From Radionuclide Therapy

    Science.gov (United States)

    Bednarz, Bryan; Besemer, Abigail

    2017-09-01

    The use of radionuclide therapy in the clinical setting is expected to increase significantly over the next decade. There is an important need to understand the radiation-induced second cancer risk associated with these procedures. In this study the radiation-induced cancer risk in five radionuclide therapy patients was investigated. These patients underwent serial SPECT imaging scans following injection as part of a clinical trial testing the efficacy of a 131Iodine-labeled radiopharmaceutical. Using these datasets the committed absorbed doses to multiple sensitive structures were calculated using RAPID, which is a novel Monte Carlo-based 3D dosimetry platform developed for personalized dosimetry. The excess relative risk (ERR) for radiation-induced cancer in these structures was then derived from these dose estimates following the recommendations set forth in the BEIR VII report. The radiation-induced leukemia ERR was highest among all sites considered reaching a maximum value of approximately 4.5. The radiation-induced cancer risk in the kidneys, liver and spleen ranged between 0.3 and 1.3. The lifetime attributable risks (LARs) were also calculated, which ranged from 30 to 1700 cancers per 100,000 persons and were highest for leukemia and the liver for both males and females followed by radiation-induced spleen and kidney cancer. The risks associated with radionuclide therapy are similar to the risk associated with external beam radiation therapy.

  3. Production of plastified wood with stronger static bending strength means of polymerization induced by gamma radiation

    International Nuclear Information System (INIS)

    Silva Filho, Elias

    1999-01-01

    The use of gamma radiation to obtain wood-polymer composites is one of the applications of radiation that presents the most commercial interest. The process, denominated radiopolymerization, comprises the impregnation of monomers into the completely dried wood followed by exposure to gamma radiation to induce polymerization of the impregnated monomers. I this context, the present work aimed the application of this process to seven kinds of wood existing in the brazilian forests. The considered monomer is styrene and the gamma source is Cobalt-60. The obtained wood-polystyrene composites were found to have stronger static bending strength. (author)

  4. Role of urea in controlling radiation-induced changes in some amino acids level and protein end products in blood serum of rats

    International Nuclear Information System (INIS)

    El-Kashef, H.S.; Saada, H.N.

    1991-01-01

    In previous studies (Helen Saada, 1982), urea could successfully act as a good radio-protector. It helps the recovery from changes induced by gamma irradiation in soluble protein contents, and percentage of protein fractions as well as some enzymatic activity. In the present study, it has been found that urea acts also as adequate radioprotector against radiation induced changes in the level of free and tied amino acids, glucosamine,free ammonia and urea concentration in the blood serum of white rats. The radioprotective role of urea was very clear on the first day after irradiation as manifested by the levels of free amino acids and protein end products (urea and ammonia). While in the case of tied amino acids, the action of urea as a radioprotector could be noticed lately, on the third post-irradiation day. The recovery from radiation hazards depended not only on the time lapse after irradiation but also on the chemical structure of the molecule which presents or constitutes the biological matter.2 tab.,1 fig

  5. Detection of mitochondrial DNA deletions in human cells induced by ionizing radiation

    International Nuclear Information System (INIS)

    Liu, Qing-Jie; Feng, Jiang-Bin; Lu, Xue; Li, Yu-Wen; Chen, De-Qing

    2008-01-01

    Full text: Purpose: To screen the novel mitochondrial DNA (mt DNA) deletions induced by ionizing radiation, and analyze the several kinds of mt DNA deletions, known as 3895 bp, 889 bp, 7436 bp or 4934 bp deletions. Methods: Long-range PCR with two pairs of primers, which could amplify the whole human mitochondrial genome, was used to analyze the lymphoblastoid cell line before and after exposed to 10 Gy 60 Co γ-rays. The limited condition PCR was used to certify the possible mt DNA deletion showed by long-range PCR. The PCR products were purified, cloned, sequenced and the sequence result were BLASTed. Regular PCR or nest-PCR were used to analyze the 3895 bp, 889 bp, 7436 bp or 4934 bp deletions before and after radiation exposure. The final PCR products were purified, sequenced and BALSTed on standard human mitochondrial genome sequence database. Results: (1) The predicted bands of mt DNA were observed on the control cell lines, and the possible mt DNA deletions were also detected on the irradiated cell lines. The deletions were certified by the limited condition PCR. The sequence BLAST results of the cloned PCR products showed that two kinds of deletions, 7455 bp deletion (nt 475-7929 in heavy strand) and 9225 bp deletion (nt 7714-369 in heavy strand), which were between two 8 bp direct repeats. Further bioinformatics analysis showed that the two deletions were novel deletions. (2) The 889 bp and 3895 bp deletion were not detected for the cell line samples not exposed to 60 Co γ-rays. The 889 bp and 3895 bp deletions were detected on samples exposed to 10 Gy 60 Co γ-rays. The BALST results showed that the 889 bp and 3895 deletions flanked nt 11688 bp-12576, nt 548 bp-4443, respectively. The 7436 bp deletion levels were not changed much before and after irradiation. (3) The 4934 bp deletions had the same pattern as 7436 bp deletion, but it could induced by radiation. Conclusions: Ionizing radiation could induce the human lymphoblastoid two novel mt DNA

  6. Radiation induced changes in the airway - anaesthetic implications ...

    African Journals Online (AJOL)

    Radiation induced changes in the airway - anaesthetic implications: case report. Mallika Balakrishnan, Renju Kuriakose, Rachel Cherian Koshy. Abstract. Radiation induces a variety of changes in the airway that can potentially lead to difficult intubation. Osteoradionecrosis (ORN) of the mandible, a severe consequence of ...

  7. Poor outcome in radiation-induced constrictive pericarditis

    International Nuclear Information System (INIS)

    Karram, T.; Rinkevitch, D.; Markiewicz, W.

    1993-01-01

    The purpose was to compare the outcome of patients with radiation-induced constrictive pericarditis versus patients with constiction due to another etiology. Twenty patients with constrictive pericarditis were seen during 1975-1986 at a single medical center. Six had radiation-induced constrictive pericarditis (Group A). The etiology was idiopathic in ten subjects and secondary to carcinomatous encasement, chronic renal failure, purulent infection and tuberculosis in one patient each (Group B, N = 14). Meang age was 53.4 ± 15.5 years. Extensive pericardiectomy was performed in 3/6 Group A and 13/14 Group B patients. All Group A patients died, 4 weeks - 11 years post-diagnosis (median = 10 months). Two Group A patients died suddenly, one died post-operatively of respiratory failure, another of pneumonia and two of recurrent carcinoma. Thirteen Group B patients are alive (median follow-up = 72 months). The only death in this group was due to metastatic cancer. The poor outcome with radiation-induced constriction is probably multi-factorial. Poor surgical outcome is to be expected in patients with evidence of recurrent tumor, high-dose irradiation, pulmonary fibrosis or associated radiation-induced myocardinal, valvular or coronary damage

  8. Poor outcome in radiation-induced constrictive pericarditis

    Energy Technology Data Exchange (ETDEWEB)

    Karram, T.; Rinkevitch, D.; Markiewicz, W. (Technion Medical School, Haifa (Israel))

    1993-01-15

    The purpose was to compare the outcome of patients with radiation-induced constrictive pericarditis versus patients with constiction due to another etiology. Twenty patients with constrictive pericarditis were seen during 1975-1986 at a single medical center. Six had radiation-induced constrictive pericarditis (Group A). The etiology was idiopathic in ten subjects and secondary to carcinomatous encasement, chronic renal failure, purulent infection and tuberculosis in one patient each (Group B, N = 14). Meang age was 53.4 [+-] 15.5 years. Extensive pericardiectomy was performed in 3/6 Group A and 13/14 Group B patients. All Group A patients died, 4 weeks - 11 years post-diagnosis (median = 10 months). Two Group A patients died suddenly, one died post-operatively of respiratory failure, another of pneumonia and two of recurrent carcinoma. Thirteen Group B patients are alive (median follow-up = 72 months). The only death in this group was due to metastatic cancer. The poor outcome with radiation-induced constriction is probably multi-factorial. Poor surgical outcome is to be expected in patients with evidence of recurrent tumor, high-dose irradiation, pulmonary fibrosis or associated radiation-induced myocardinal, valvular or coronary damage.

  9. Radiation induced pesticidal microbes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Yup; Lee, Y. K.; Kim, J. S.; Kim, J. K.; Lee, S. J.; Lim, D. S

    2001-01-01

    To isolate pesticidal microbes against plant pathogenic fungi, 4 strains of bacteria(K1. K3, K4, YS1) were isolated from mushroom compost and hot spring. K4, K1, K3, YS1 strain showed wide antifungal spectrum and high antifungal activities against 12 kinds of fungi. Specific proteins and the specific transcribed genes were found from the YS1 and its radiation-induced mutants. And knock-out mutants of antifungal activity were derived by transposon mutagenesis. From these knock-out mutants, the antifungal activity related genes and its modification by gamma-ray radiation are going to be studied. These results suggested that radiation could be an useful tool for the induction of functional mutants.

  10. Radiation induced pesticidal microbes

    International Nuclear Information System (INIS)

    Kim, Ki Yup; Lee, Y. K.; Kim, J. S.; Kim, J. K.; Lee, S. J.; Lim, D. S.

    2001-01-01

    To isolate pesticidal microbes against plant pathogenic fungi, 4 strains of bacteria(K1. K3, K4, YS1) were isolated from mushroom compost and hot spring. K4, K1, K3, YS1 strain showed wide antifungal spectrum and high antifungal activities against 12 kinds of fungi. Specific proteins and the specific transcribed genes were found from the YS1 and its radiation-induced mutants. And knock-out mutants of antifungal activity were derived by transposon mutagenesis. From these knock-out mutants, the antifungal activity related genes and its modification by gamma-ray radiation are going to be studied. These results suggested that radiation could be an useful tool for the induction of functional mutants

  11. Decontamination method and device for radiation contaminated product

    International Nuclear Information System (INIS)

    Morikawa, Kenji; Ohinata, Hiroshi; Omata, Kazuo; Sato, Toshihiko; Nakajima, Yoshihiko; Ichikawa, Seigo.

    1996-01-01

    In the present invention, radiation contaminated products generated during shot peening are decontaminated by a chelating agent, and the chelating agent is removed from the radiation contaminated products. Then the temperature of the radiation contaminated products is elevated by hot blowing at a temperature higher than a boiling point of the solvent. Then, a solvent is added to the radiation contaminated products and the solvent is evaporated abruptly. The solution of the chelating agent remained while being deposited thereto is removed by evaporation to remove it from the radiation contaminated products together with the solvent. With such procedures, all of the decontamination steps can be completed in one device without requiring a large space or not moving the radiation contaminated products on every step. (T.M.)

  12. Effect of radiation-induced amorphization on smectite dissolution.

    Science.gov (United States)

    Fourdrin, C; Allard, T; Monnet, I; Menguy, N; Benedetti, M; Calas, G

    2010-04-01

    Effects of radiation-induced amorphization of smectite were investigated using artificial irradiation. Beams of 925 MeV Xenon ions with radiation dose reaching 73 MGy were used to simulate the effects generated by alpha recoil nuclei or fission products in the context of high level nuclear waste repository. Amorphization was controlled by X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. An important coalescence of the smectite sheets was observed which lead to a loss of interparticle porosity. The amorphization is revealed by a loss of long-range structure and accompanied by dehydroxylation. The dissolution rate far-from-equilibrium shows that the amount of silica in solution is two times larger in the amorphous sample than in the reference clay, a value which may be enhanced by orders of magnitude when considering the relative surface area of the samples. Irradiation-induced amorphization thus facilitates dissolution of the clay-derived material. This has to be taken into account for the safety assessment of high level nuclear waste repository, particularly in a scenario of leakage of the waste package which would deliver alpha emitters able to amorphize smectite after a limited period of time.

  13. Use of capillary GC-MS for identification of radiation-induced DNA base damage: Implications for base-excision repair of DNA

    International Nuclear Information System (INIS)

    Dizdaroglu, M.

    1985-01-01

    Application of GC-MS to characterization of radiation-induced base products of DNA and DNa base-amino acid crosslinks is presented. Samples of γ-irradiated DNa were hydrolyzed with formic acid, trimethylsilylated and subjected to GC-MS analysis using a fused silica capillary column. Hydrolysis conditions suitable for the simultaneous analysis of the radiation-induced products of all four DNA bases in a single run were determined. The trimethylsilyl derivatives of these products had excellent GC-properties and easily interpretable mass spectra. The complementary use of t-butyldimetylsilyl derivatives was also demonstrated. Moreover, the usefulness of this method for identification of radiation-induced DNA base-amino acid crosslinks was shown using γ-irradiated mixtures of thymine and tyrosine or phenylalanine. Because of the excellent resolving power of capillary GC and the instant and highly sensitive identification by MS, GC-MS is suggested as a suitable technique for identification of altered bases removed from DNA by base-excision repair enzymes

  14. Peculiarities of radiation induced craniopharyngioma

    Energy Technology Data Exchange (ETDEWEB)

    Sataev, N.M. (Uzbekskij Nauchno-Issledovatel' skij Inst. Onkologii i Radiologii, Tashkent (USSR))

    1982-03-01

    Due to intracranial implantation of a radiosource in rabbit brain craniopharyngioma appeared. Its specific feature is grandular differentiation of embryonal epithelium of residuals of hypophysical (craniopharyngial) passage and the presence of focuses of blood vessel tumor degeneration of hemangioma type in its stroma. It is suggested that radiation craniopharyngioma is developed along the way of epigenetic changes of cellular elements of embryonal epithelium induced by radiation.

  15. Peculiarities of radiation induced craniopharyngioma

    International Nuclear Information System (INIS)

    Sataev, N.M.

    1982-01-01

    Due to intracranial implantation of a radiosource in rabbit brain craniopharyngioma appeared. Its specific feature is grandular differentiation of embryonal epithelium of residuals of hypophysical (craniopharyngial) passage and the presence of focuses of blood vessel tumor degeneration of hemangioma type in its stroma. It is suggested that radiation craniopharyngioma is developed along the way of epigenetic changes of cellular elements of embryonal epithelium induced by radiation

  16. Radiation-Induced Upregulation of Gene Expression From Adenoviral Vectors Mediated by DNA Damage Repair and Regulation

    International Nuclear Information System (INIS)

    Nokisalmi, Petri; Rajecki, Maria; Pesonen, Sari; Escutenaire, Sophie; Soliymani, Rabah; Tenhunen, Mikko; Ahtiainen, Laura; Hemminki, Akseli

    2012-01-01

    Purpose: In the present study, we evaluated the combination of replication-deficient adenoviruses and radiotherapy in vitro. The purpose of the present study was to analyze the mechanism of radiation-mediated upregulation of adenoviral transgene expression. Methods and Materials: Adenoviral transgene expression (luciferase or green fluorescent protein) was studied with and without radiation in three cell lines: breast cancer M4A4-LM3, prostate cancer PC-3MM2, and lung cancer LNM35/enhanced green fluorescent protein. The effect of the radiation dose, modification of the viral capsid, and five different transgene promoters were studied. The cellular responses were studied using mass spectrometry and immunofluorescence analysis. Double strand break repair was modulated by inhibitors of heat shock protein 90, topoisomerase-I, and DNA protein kinase, and transgene expression was measured. Results: We found that a wide range of radiation doses increased adenoviral transgene expression regardless of the cell line, transgene, promoter, or viral capsid modification. Treatment with adenovirus, radiation, and double strand break repair inhibitors resulted in persistence of double strand breaks and subsequent increases in adenovirus transgene expression. Conclusions: Radiation-induced enhancement of adenoviral transgene expression is linked to DNA damage recognition and repair. Radiation induces a global cellular response that results in increased production of RNA and proteins, including adenoviral transgene products. This study provides a mechanistic rationale for combining radiation with adenoviral gene delivery.

  17. Radiation and desiccation response motif mediates radiation induced gene expression in D. radiodurans

    International Nuclear Information System (INIS)

    Anaganti, Narasimha; Basu, Bhakti; Apte, Shree Kumar

    2015-01-01

    Deinococcus radiodurans is an extremophile that withstands lethal doses of several DNA damaging agents such as gamma irradiation, UV rays, desiccation and chemical mutagens. The organism responds to DNA damage by inducing expression of several DNA repair genes. At least 25 radiation inducible gene promoters harbour a 17 bp palindromic sequence known as radiation and desiccation response motif (RDRM) implicated in gamma radiation inducible gene expression. However, mechanistic details of gamma radiation-responsive up-regulation in gene expression remain enigmatic. The promoters of highly radiation induced genes ddrB (DR0070), gyrB (DR0906), gyrA (DR1913), a hypothetical gene (DR1143) and recA (DR2338) from D. radiodurans were cloned in a green fluorescence protein (GFP)-based promoter probe shuttle vector pKG and their promoter activity was assessed in both E. coli as well as in D. radiodurans. The gyrA, gyrB and DR1143 gene promoters were active in E. coli although ddrB and recA promoters showed very weak activity. In D. radiodurans, all the five promoters were induced several fold following 6 kGy gamma irradiation. Highest induction was observed for ddrB promoter (25 fold), followed by DR1143 promoter (15 fold). The induction in the activity of gyrB, gyrA and recA promoters was 5, 3 and 2 fold, respectively. To assess the role of RDRM, the 17 bp palindromic sequence was deleted from these promoters. The promoters devoid of RDRM sequence displayed increase in the basal expression activity, but the radiation-responsive induction in promoter activity was completely lost. The substitution of two conserved bases of RDRM sequence yielded decreased radiation induction of PDR0070 promoter. Deletion of 5 bases from 5'-end of PDR0070 RDRM increased basal promoter activity, but radiation induction was completely abolished. Replacement of RDRM with non specific sequence of PDR0070 resulted in loss of basal expression and radiation induction. The results demonstrate that

  18. Protective effect of flax seed oil against radiation induced hematological alterations in mammals

    International Nuclear Information System (INIS)

    Sharma, Jyoti; Singh, Ritu; Goyal, P.K.; Singh, Seema

    2014-01-01

    Human beings are exposed to ionizing and non ionizing radiation from natural as well as manmade sources. Ionizing radiations are one of the predominant exogenous factors that have deleterious consequences to human life. Exposure to ionizing radiations damages the hematopoietic, gastrointestinal or central nervous systems, depending on radiation dose. Hence, there is an urgent need to prevent such deleterious effects caused due to ionizing radiations. Chemical protection involves the use of synthetic and natural products against planned radiation exposure. Medicinal plants are rich in antioxidants and their chemical constituents may be the potential source for radioprotective agents. Linum usitatissimum plant (family: Linaceae), source of flaxseed oil (FSO), is well known for its anticarcinogenic, antidiabetic, cardioprotector, antiulcer properties owing to the presence of various phytochemicals. The present study has been focused to find out the preventive action of flaxseed oil against radiation induced hematological and biochemical lesions in mammals. For this purpose, FSO (50μL/animal/day) was orally administered to Swiss albino mice for five days, prior to 6 Gy gamma radiation exposure. The animals were sacrificed on 1 st , 3 rd , 7 th , 15 th and 30 th day after irradiation. Radiation treated control group exhibited significant reduction in erythrocytes count, hemoglobin content, hematocrit value and total WBC count in peripheral blood. In contrast, pretreatment with FSO significantly increased all these blood constituents. Further, the antioxidant parameters such as reduced glutathione, catalase, and superoxide dismutase showed a significant elevation in FSO pretreated group which were reduced in irradiated control group. Similarly, radiation induced increase lipid peroxidation in blood was significantly inhibited after FSO treatment. The present results indicate that the flaxseed oil has the ability to debilitate the radiation induced adverse alterations in

  19. ESR Study Applied To Thermal Stability Of Radiation-Induced Species Of Solid Ketoprofen

    International Nuclear Information System (INIS)

    Maltar-Strmecki, N.; Katusin-Razem, B.; Razem, D.

    2015-01-01

    Ketoprofen [2-(3-benzoylphenyl) propionic acid] is a non-steroidal anti-inflammatory drug. It has been widely used in human and veterinary medicine. Radiation processing of drugs and its ingredients is recognized as a safe and effective method among the existing technologies for sterilization and protocols that can be found in ISO 11137-1. Radiosterilization of drugs or other medical products by a suitable dose of ionizing radiation conducted in an appropriate environment ensures sterile conditions by destroying or removing vegetative and sporulating microbes from the ingredients or environment. In earlier studies the effects of gamma radiation was evaluated by selected physico-chemical methods and the observations showed that solid ketoprofen is relatively stable toward ionizing irradiation and that radiosterilization might be a suitable method for the sterilization of solid ketoprofen. The studies reported in this work were undertaken to analyse thermal stability of free radicals by accelerated aging method with a view to the determination of shelf-life. The expiration date (shelf-life) of a product is based on evaluation of both, thermal stability of free radicals, as well as on the time evolution of stable radiolysis products. Namely, storage time is determined by the time required by any degradation product in the dosage form to achieve a sufficient level to represent a risk to the patient. This work shows that ESR spectroscopy provides means for determination of thermal stability of radicals induced by gamma-irradiation in solid drugs. Therefore, despite the complex mixture of individual free radicals induced by gamma-irradiation in solid ketoprofen, the overall lifetime of free radicals could be determined by using isothermal and isochronal annealing. This study shows that radicals induced by gamma-irradiation in solid ketoprofen are stable for at least about 6 months. (author).

  20. Clustered DNA damages induced in isolated DNA and in human cells by low doses of ionizing radiation

    Science.gov (United States)

    Sutherland, B. M.; Bennett, P. V.; Sidorkina, O.; Laval, J.; Lowenstein, D. I. (Principal Investigator)

    2000-01-01

    Clustered DNA damages-two or more closely spaced damages (strand breaks, abasic sites, or oxidized bases) on opposing strands-are suspects as critical lesions producing lethal and mutagenic effects of ionizing radiation. However, as a result of the lack of methods for measuring damage clusters induced by ionizing radiation in genomic DNA, neither the frequencies of their production by physiological doses of radiation, nor their repairability, nor their biological effects are known. On the basis of methods that we developed for quantitating damages in large DNAs, we have devised and validated a way of measuring ionizing radiation-induced clustered lesions in genomic DNA, including DNA from human cells. DNA is treated with an endonuclease that induces a single-strand cleavage at an oxidized base or abasic site. If there are two closely spaced damages on opposing strands, such cleavage will reduce the size of the DNA on a nondenaturing gel. We show that ionizing radiation does induce clustered DNA damages containing abasic sites, oxidized purines, or oxidized pyrimidines. Further, the frequency of each of these cluster classes is comparable to that of frank double-strand breaks; among all complex damages induced by ionizing radiation, double-strand breaks are only about 20%, with other clustered damage constituting some 80%. We also show that even low doses (0.1-1 Gy) of high linear energy transfer ionizing radiation induce clustered damages in human cells.

  1. Radioprotective effects of melatonin on radiation-induced cataract

    International Nuclear Information System (INIS)

    Karslioglu, Ie.; Ertekin, M.V.; Taysi, S.; Kocer, Ie.; Sezen, O.; Koc, M.; Bakan, N.; Gepdiremen, A.

    2005-01-01

    One of the mechanisms proposed to explain lens opacification is the oxidation of crystallins, either by radiation or reactive oxygen species (ROS). It has been shown that melatonin has both an anti-peroxidative effect on several tissues and a scavenger effect on ROS. The purpose of this study was to determine the antioxidant role of melatonin (5 mg/kg/day) against radiation-induced cataract in the lens after total-cranium irradiation of rats with a single dose of 5 Gy. Sprague-Dawley rats were divided into four groups. Control group received neither melatonin nor irradiation. Irradiated rats (IR) and melatonin+irradiated rats (IR+Mel) groups were exposed to total cranium irradiation of 5 Gy in a single dose by using a cobalt-60 teletherapy unit. IR+Mel and melatonin (Mel) groups were administered 5 mg/kg melatonin daily by intraperitoneal injections during ten days. Chylack's cataract classification was used in this study. At the end of the 10 th day, the rats were killed and their eyes were enucleated to measure the antioxidant enzymes i.e. the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and lipid peroxidation level (malondialdehyde (MDA)). Irradiation significantly increased the MDA level, as an end product of lipid peroxidation, and also significantly decreased SOD and GSH-Px activity, emphasizing the generation of increased oxidative stress. Rats injected with melatonin only did not cause cataract formation. Melatonin supplementation with irradiation significantly increased the activity of SOD and GSH-Px enzymes and significantly decreased the MDA level. Total cranium irradiation of 5 Gy in a single dose enhanced cataract formation, and melatonin supplementation protected the lenses from radiation-induced cataract formation. Our results suggest that supplementing cancer patients with adjuvant therapy of melatonin may reduce patients suffering from toxic therapeutic regimens such as chemotherapy and/or radiotherapy and may provide

  2. Radiation-induced brain damage in children

    International Nuclear Information System (INIS)

    Oi, Shizuo; Kokunai, Takashi; Ijichi, Akihiro; Matsumoto, Satoshi; Raimondi, A.J.

    1990-01-01

    The nature and sequence of the radiation-induced changes in the brain were studied postmortem in 34 children with glioma, 22 of whom underwent central nervous system radiation therapy. Twenty received whole-brain or whole-neuroaxis radiation at a total mean dosage of 4063 cGy. Brain tissue alternations were analyzed histologically by means of various staining methods, including immunohistochemical techniques. The histological features of irradiated brains were compared with those of non-irradiated brains. Microscopic findings included demyelination (seven cases), focal necrosis (six cases), cortical atrophy (four cases), endothelial proliferation (four cases), and telangiectatic vascular proliferation with vascular thickening and oozing of a thick fluid (one case). Such findings were rare in non-irradiated patients. Demyelination was observed earliest in a patient who died 5 months after radiation therapy and was more common after 9 months. Focal necrosis was first observed 9 months post-irradiation but was more advanced and extensive after 1 year. Calcified foci were found only after 60 months. Various vascular changes such as vascular thickening and thrombosis suggested ischemic insult to the brain as a late effect of radiation injury. The results of this study suggest that the immature brain may be more sensitive to radiation than is the adult brain, and that the manifestations of radiation-induced injury depend on the time elapsed after irradiation. (author)

  3. Radiation-induced xerostomia in a patient with nasopharyngeal ...

    African Journals Online (AJOL)

    OBJECTIVE: This study reports a case of radiation-induced xerstomia in a patient with nasopharyngeal cancer, to emphasize the need for prompt oral care to prevent untoward effects of xerostomia and to improve patients' quality of life. CASE REPORT: A 60 year old man diagnosed of radiation-induced xerostomia, after 6 ...

  4. 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

  5. Effectiveness of the herbal medicine daikenchuto for radiation-induced enteritis.

    Science.gov (United States)

    Takeda, Takashi; Kamiura, Shouji; Kimura, Tadashi

    2008-07-01

    Radiation-induced enteritis is a serious clinical problem for which there is currently no recommended standard management. Daikenchuto (DKT) is a Japanese herbal medicine that has been used to treat adhesive bowel obstruction in Japan. This report describes a patient with radiation-induced enteritis whose clinical symptoms were much improved by treatment with DKT. The patient was administered DKT, a traditional Japanese herbal formula, orally (2.5 g 3 times daily). Abdominal distention was evaluated objectively with computed tomography. Gastrointestinal symptoms associated with radiation-induced enteritis were controlled successfully with DKT treatment. DKT treatment may be useful for the management of radiation-induced enteritis.

  6. Radiation chemically induced telomerization of ethylene with selected telogens

    International Nuclear Information System (INIS)

    Wachtendunk, H.J. von.

    1975-01-01

    The suitability of different compounds for the use as telogenes in the telomerization of ethylene has been studied. In all cases the reactions are initiated by the γ-radiation of a 60 Co-source. Temperature programed gas chromatography has proved to be an adequate method of analysis. In the teleomerization process with ethylene also methane tri carboxylic acid tri-ethylene ester (MTE), ortho-formic acid tri-ethylene ester (o-ASE), formic acid, bromium cyane, chlorine cyane and dicyane have been used. The telomerization of MTE and ethylene has been performed successfully with a high yield. The dependence of the reaction on temperature, pressure, radiation dose has been studied as well as the influence of a solvent (acetonitrile). In the attempt to telomerize ortho-formic acid tri-ethylene ester only high molecular weight solid product could be isolated. No interpretable results could be obtained for the telomerization of formic acid with ethylene. In the case of the radiation induced telomerization of chlorine cyane or di-cyane with ethylene in the gas phase, no reaction products could be found. No telomerization between di-cyane and ethylene has been observed even when palladium (II)-cyanide is used as a catalyst of after cocatalys is with triphenyl-phosphile in acetonitrile. (orig./HK) [de

  7. Kinetics of radiation-induced segregation in ternary alloys

    International Nuclear Information System (INIS)

    Lam, N.O.; Kumar, A.; Wiedersich, H.

    1982-01-01

    Model calculations of radiation-induced segregation in ternary alloys have been performed, using a simple theory. The theoretical model describes the coupling between the fluxes of radiation-induced defects and alloying elements in an alloy A-B-C by partitioning the defect fluxes into those occurring via A-, B-, and C-atoms, and the atom fluxes into those taking place via vacancies and interstitials. The defect and atom fluxes can be expressed in terms of concentrations and concentration gradients of all the species present. With reasonable simplifications, the radiation-induced segregation problem can be cast into a system of four coupled partial-differential equations, which can be solved numerically for appropriate initial and boundary conditions. Model calculations have been performed for ternary solid solutions intended to be representative of Fe-Cr-Ni and Ni-Al-Si alloys under various irradiation conditions. The dependence of segregation on both the alloy properties and the irradiation variables, e.g., temperature and displacement rate, was calculated. The sample calculations are in good qualitative agreement with the general trends of radiation-induced segregation observed experimentally

  8. Seven cases of radiation-induced cutaneous squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Sugita, Kazunari; Yamamoto, Osamu; Suenaga, Yoshinori [Univ. of Occupational and Environmental Health, Kitakyushu, Fukuoka (Japan). School of Medicine

    2000-09-01

    We report 7 cases of radiation-induced skin cancer. The diagnosis was based on the history of radiotherapy for benign skin diseases (5 cases) and of occupational exposures to medical doctors (2 cases). All cases were squamous cell carcinomas which arose from chronic radiodermatitis. The estimated latent period of these tumors ranged from 6 to 64 years, with an average of 29.9 years. After surgical treatments of the lesions, no local recurrences were observed in all cases. Benign skin diseases had sometimes been treated with low-energy radiation before the 1960s. Considering the estimated latent period, the peak time point of developing risk of radiation-induced skin cancer by such treatment has been already passed, however, the danger of it should not be ignored in future. In association with multiplicity of radiation usage, occupational exposure of radiation may develop the risk of occurrence of skin cancer in future. Therefore, we should recognize that radiation-induced skin cancer is not in the past. In the cases of chronic skin diseases showing warty keratotic growth, erosion and ulcer, we should include chronic radio-dermatitis in the differential diagnosis. It is necessary to recall all patients about the history of radiotherapy or radiation exposure. Rapid histopathological examination is mandatory because of the suspicion of radiation-induced skin cancer. (author)

  9. Seven cases of radiation-induced cutaneous squamous cell carcinoma

    International Nuclear Information System (INIS)

    Sugita, Kazunari; Yamamoto, Osamu; Suenaga, Yoshinori

    2000-01-01

    We report 7 cases of radiation-induced skin cancer. The diagnosis was based on the history of radiotherapy for benign skin diseases (5 cases) and of occupational exposures to medical doctors (2 cases). All cases were squamous cell carcinomas which arose from chronic radiodermatitis. The estimated latent period of these tumors ranged from 6 to 64 years, with an average of 29.9 years. After surgical treatments of the lesions, no local recurrences were observed in all cases. Benign skin diseases had sometimes been treated with low-energy radiation before the 1960s. Considering the estimated latent period, the peak time point of developing risk of radiation-induced skin cancer by such treatment has been already passed, however, the danger of it should not be ignored in future. In association with multiplicity of radiation usage, occupational exposure of radiation may develop the risk of occurrence of skin cancer in future. Therefore, we should recognize that radiation-induced skin cancer is not in the past. In the cases of chronic skin diseases showing warty keratotic growth, erosion and ulcer, we should include chronic radio-dermatitis in the differential diagnosis. It is necessary to recall all patients about the history of radiotherapy or radiation exposure. Rapid histopathological examination is mandatory because of the suspicion of radiation-induced skin cancer. (author)

  10. Membrane phospholipids and radiation-induced death of mammalian cells

    International Nuclear Information System (INIS)

    Wolters, H.

    1987-01-01

    Radiation-induced cell killing is generally believed to be a consequence of residual DNA damage or damage that is mis-repaired. However, besides this DNA damage, damage to other molecules or structures of the cell may be involved in the killing. Especially membranes have been suggested as a determinant in cellular radiosensitivity. In this thesis experiments are described, dealing with the possible involvement of membranes in radiation-induced killing of mammalian cells. A general treatise of membrane structure is followed by information concerning deleterious effects of radiation on membranes. Consequences of damage to structure and function of membranes are reviewed. Thereafter evidence relating to the possible involvement of membranes in radiation-induced cell killing is presented. (Auth.)

  11. Gamma radiation effects in packaging for sterilization of health products and their constituents paper and plastic film

    Science.gov (United States)

    B. G. Porto, Karina Meschini; Napolitano, Celia Marina; Borrely, Sueli Ivone

    2018-01-01

    The integrity of materials containing packaging (natural or synthetic polymers) is essential to keep the aseptic condition of commercialized products (health care products, food and pharmaceuticals). The objective of this paper was to study gamma radiation effects (25 kGy, 40 kGy and 50 kGy) on the main properties of paper and multilayer films (polyester and polyethylene). Paper and multilayer films are components of packaging (pouches) for radiation sterilization containing medical equipment or products. Paper was the more radiation sensitive among the studied materials and radiation effects were more pronounced at brightness, pH, tearing resistance, bursting strength and tensile strength. Concerning plastic film, no pinholes were induced by radiation and the effects on the tensile strength were not significant. Although the seal strength packaging (pouches) decreased according to increasing dose, the sealing integrity was preserved.

  12. Radiation-induced alternative transcripts as detected in total and polysome-bound mRNA.

    Science.gov (United States)

    Wahba, Amy; Ryan, Michael C; Shankavaram, Uma T; Camphausen, Kevin; Tofilon, Philip J

    2018-01-02

    Alternative splicing is a critical event in the posttranscriptional regulation of gene expression. To investigate whether this process influences radiation-induced gene expression we defined the effects of ionizing radiation on the generation of alternative transcripts in total cellular mRNA (the transcriptome) and polysome-bound mRNA (the translatome) of the human glioblastoma stem-like cell line NSC11. For these studies, RNA-Seq profiles from control and irradiated cells were compared using the program SpliceSeq to identify transcripts and splice variations induced by radiation. As compared to the transcriptome (total RNA) of untreated cells, the radiation-induced transcriptome contained 92 splice events suggesting that radiation induced alternative splicing. As compared to the translatome (polysome-bound RNA) of untreated cells, the radiation-induced translatome contained 280 splice events of which only 24 were overlapping with the radiation-induced transcriptome. These results suggest that radiation not only modifies alternative splicing of precursor mRNA, but also results in the selective association of existing mRNA isoforms with polysomes. Comparison of radiation-induced alternative transcripts to radiation-induced gene expression in total RNA revealed little overlap (about 3%). In contrast, in the radiation-induced translatome, about 38% of the induced alternative transcripts corresponded to genes whose expression level was affected in the translatome. This study suggests that whereas radiation induces alternate splicing, the alternative transcripts present at the time of irradiation may play a role in the radiation-induced translational control of gene expression and thus cellular radioresponse.

  13. Non-targeted bystander effects induced by ionizing radiation

    International Nuclear Information System (INIS)

    Morgan, William F.; Sowa, Marianne B.

    2007-01-01

    Radiation-induced bystander effects refer to those responses occurring in cells that were not subject to energy deposition events following ionizing radiation. These bystander cells may have been neighbors of irradiated cells, or physically separated but subject to soluble secreted signals from irradiated cells. Bystander effects have been observed in vitro and in vivo and for various radiation qualities. In tribute to an old friend and colleague, Anthony V. Carrano, who would have said 'well what are the critical questions that should be addressed, and so what?', we review the evidence for non-targeted radiation-induced bystander effects with emphasis on prevailing questions in this rapidly developing research field, and the potential significance of bystander effects in evaluating the detrimental health effects of radiation exposure

  14. Radiation-induced hondrosarcoma - a clinical case from our practice

    International Nuclear Information System (INIS)

    Marinova, L.; Georgiev, R.; Mihaylova, I.

    2013-01-01

    We present a clinical case of radiation - induced occipital extracerebral chondrosarcoma in 36 years old young man. The patient had undergone two brain operations 8 years ago due to oligodendroglioma in the left temporo - parietal area. These surgical interventions were partial and subtotal tumor extirpation, followed by local radiotherapy to the brain to a total dose of 56Gy. The necessity of immunohistochemistry (IHH) analysis for pathologic differential diagnosis in high grade brain and peripheral tumors was discussed. In this particular case a precise differential diagnosis between peripheral chondrosarcoma and Ewing sarcoma/pPNET is needed. important risk factors for the development of radiation-induced brain tumors and chondrosarcoma, extremely rarely diagnosed, was discussed. A very accurate precising of the treatment radiation dose is needed in young patients with malignant brain tumors, not only in the surrounding healthy brain tissues, but also in other tissues, such as skin, subcutaneous layer and bone. The exceeding of the radiation dose in the bone above 45-50 Gy, increases the risk of radiation - induced sarcoma with latent period over 8 years. Key words: Hondrosarcoma. Radiotherapy. Radiation-induced Sarcoma. Complex Treatment. Immunohistochemistry

  15. Bile acids in radiation-induced diarrhea

    International Nuclear Information System (INIS)

    Arlow, F.L.; Dekovich, A.A.; Priest, R.J.; Beher, W.T.

    1987-01-01

    Radiation-induced bowel disease manifested by debilitating diarrhea is an unfortunate consequence of therapeutic irradiation for pelvic malignancies. Although the mechanism for this diarrhea is not well understood, many believe it is the result of damage to small bowel mucosa and subsequent bile acid malabsorption. Excess amounts of bile acids, especially the dihydroxy components, are known to induce water and electrolyte secretion and increase bowel motility. We have directly measured individual and total bile acids in the stool samples of 11 patients with radiation-induced diarrhea and have found bile acids elevated two to six times normal in eight of them. Our patients with diarrhea and increased bile acids in their stools had prompt improvement when given cholestyramine. They had fewer stools and returned to a more normal life-style

  16. Ionizing radiation induces stemness in cancer cells.

    Directory of Open Access Journals (Sweden)

    Laura Ghisolfi

    Full Text Available The cancer stem cell (CSC model posits the presence of a small number of CSCs in the heterogeneous cancer cell population that are ultimately responsible for tumor initiation, as well as cancer recurrence and metastasis. CSCs have been isolated from a variety of human cancers and are able to generate a hierarchical and heterogeneous cancer cell population. CSCs are also resistant to conventional chemo- and radio-therapies. Here we report that ionizing radiation can induce stem cell-like properties in heterogeneous cancer cells. Exposure of non-stem cancer cells to ionizing radiation enhanced spherogenesis, and this was accompanied by upregulation of the pluripotency genes Sox2 and Oct3/4. Knockdown of Sox2 or Oct3/4 inhibited radiation-induced spherogenesis and increased cellular sensitivity to radiation. These data demonstrate that ionizing radiation can activate stemness pathways in heterogeneous cancer cells, resulting in the enrichment of a CSC subpopulation with higher resistance to radiotherapy.

  17. Specitic gene alterations in radiation-induced tumorigenesis

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Joo Mee; Kang, Chang Mo; Lee, Seung Sook; Cho, Chul Koo; Bae, Sang Woo; Lee, Su Jae; Lee, Yun Sil [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2004-07-01

    To identify a set of genes involved in the development of radiation-induced tumorigenesis, we used DNA microarrays consisting of 1,176 mouse genes and compared expression profiles of radioresistant cells, designated NIH3T3-R1 and -R4. These cells were tumorigenic in a nude mouse grafting system, as compared to the parental NIH3T3 cells. Expressions of MDM2, CDK6 and CDC25B were found to increase more than 3-fold. Entactin protein levels were downregulated in NIH3T3-R1 and -R4 cells. Changes in expression genes were confirmed by reverse transcription-PCR or western blotting. When these genes were transfected to NIH3T3 cells, the CDC25B and MDM2 overexpressing NIH3T3 cells showed radioresistance, while 2 CDK6 overexpressing cells did not. In the case of entactin overexpressing NIH3T3-R1 or R-4 cells were still radioresistant. Furthermore, the CDC25B and MDM2 overexpressing cells grafted to nude mice, were tumorigenic. NIH3T3-R1 and R4 cells showed increased radiation-induced apoptosis, accompanied by faster growth rate, rather than and earlier radiation-induced G2/M phase arrest, suggesting that the radioresistance of NIH3T3-R1 and R4 cells was due to faster growth rate, rather than induction of apoptosis. In the case of MDM2 and CDC25B overexpressing cells, similar phenomena, such as increased apoptosis and faster growth rate, were shown. The above results, therefore, demonstrate involvement of CDC25B and MDM2 overexpression in radiation-induced tumorigenesis and provide novel targets for detection of radiation-induced carcinogenesis.

  18. Radiation-induced degradation of 4-chloroaniline in aqueous solution

    International Nuclear Information System (INIS)

    Sanchez, M.; Wolfger, H.; Getoff, N.

    2002-01-01

    The radiation-induced decomposition of 4-chloroaniline (4-ClA) was studied under steady-state conditions using aqueous solutions saturated with air, pure oxygen, N 2 O, argon and argon in the presence of t-Butanol. Using HPLC-method, the initial G-values of the substrate degradation as well as of a number of radiolytic products were determined. The formation of aminophenols, chlorophenols, aniline and phenol in addition to chloride, ammonia, formaldehyde and mixture of aldehydes as well as carboxylic acids was studied as a function of absorbed dose. Based on the experimental data, probable reaction mechanisms for the degradation of 4-ClA by γ-rays and the formation of the identified products are presented

  19. Induced Compton-scattering effects in radiation-transport approximations

    International Nuclear Information System (INIS)

    Gibson, D.R. Jr.

    1982-02-01

    The method of characteristics is used to solve radiation transport problems with induced Compton scattering effects included. The methods used to date have only addressed problems in which either induced Compton scattering is ignored, or problems in which linear scattering is ignored. Also, problems which include both induced Compton scattering and spatial effects have not been considered previously. The introduction of induced scattering into the radiation transport equation results in a quadratic nonlinearity. Methods are developed to solve problems in which both linear and nonlinear Compton scattering are important. Solutions to scattering problems are found for a variety of initial photon energy distributions

  20. Evaluation of edaravone against radiation-induced oral mucositis in mice.

    Science.gov (United States)

    Nakajima, Noriko; Watanabe, Shinichi; Kiyoi, Takeshi; Tanaka, Akihiro; Suemaru, Katsuya; Araki, Hiroaki

    2015-03-01

    Oral mucositis induced by radiotherapy for cancers of the head and neck reduce the quality of life of patients. However, effective therapeutic agents are lacking. Symptomatic treatment involves local anesthesia and analgesia. We focused on the antioxidant effects of edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one; Radicut(®)). Oral mucositis was induced on the tongue tips of mice using a single dose of X-rays (20 Gy). To evaluate the protective effect of edaravone (30 and 300 mg/kg), administration was carried out 30 min before irradiation. Survival, oral mucositis score, myeloperoxidase activity, and levels of 2-Thiobarbituric acid reactive substances were measured, and all were improved compared with those of control mice. A significant difference was not found in terms of survival due to edaravone. Histopathologic findings also highlighted the beneficial features of edaravone. Edaravone reduced the production of reactive oxygen species. These findings suggest that the protective effect of edaravone against radiation-induced oral mucositis is through an antioxidant effect. Copyright © 2015 Japanese Pharmacological Society. Production and hosting by Elsevier B.V. All rights reserved.

  1. Simulating Space Radiation-Induced Breast Tumor Incidence Using Automata.

    Science.gov (United States)

    Heuskin, A C; Osseiran, A I; Tang, J; Costes, S V

    2016-07-01

    Estimating cancer risk from space radiation has been an ongoing challenge for decades primarily because most of the reported epidemiological data on radiation-induced risks are derived from studies of atomic bomb survivors who were exposed to an acute dose of gamma rays instead of chronic high-LET cosmic radiation. In this study, we introduce a formalism using cellular automata to model the long-term effects of ionizing radiation in human breast for different radiation qualities. We first validated and tuned parameters for an automata-based two-stage clonal expansion model simulating the age dependence of spontaneous breast cancer incidence in an unexposed U.S. We then tested the impact of radiation perturbation in the model by modifying parameters to reflect both targeted and nontargeted radiation effects. Targeted effects (TE) reflect the immediate impact of radiation on a cell's DNA with classic end points being gene mutations and cell death. They are well known and are directly derived from experimental data. In contrast, nontargeted effects (NTE) are persistent and affect both damaged and undamaged cells, are nonlinear with dose and are not well characterized in the literature. In this study, we introduced TE in our model and compared predictions against epidemiologic data of the atomic bomb survivor cohort. TE alone are not sufficient for inducing enough cancer. NTE independent of dose and lasting ∼100 days postirradiation need to be added to accurately predict dose dependence of breast cancer induced by gamma rays. Finally, by integrating experimental relative biological effectiveness (RBE) for TE and keeping NTE (i.e., radiation-induced genomic instability) constant with dose and LET, the model predicts that RBE for breast cancer induced by cosmic radiation would be maximum at 220 keV/μm. This approach lays the groundwork for further investigation into the impact of chronic low-dose exposure, inter-individual variation and more complex space radiation

  2. Construction of radiation - induced metastasis model in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Kuk; Jang, Su Jin; Kang, Sung Wook; Kim, Jae Sung; Hwang, Sang Gu; Kang, Joo Hyun [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2011-05-15

    In treatment of cancer, distant metastases are important limiting factor because an estimated 50% of all cancer patients will develop metastases, and the metastases are major causing of cancer treatment failure. Recently a few reports indicated {gamma}-radiation induced an increase of invasiveness of several cancer cells. In this study, we had tried to show the possibility that radiation could also induce metastasis in vivo system. To prove our hypothesis, we constructed primary tumor by using C6-TL transfectant cell line expressing HSV1-tk and firefly luciferase (fLuc), and then {gamma}-radiation was treated to xenografts locally. Treatment of {gamma}-radiation to primary C6-TL xenografts of mice reduced size of xenografts and elongated survival of mice than those of mock control mice. But we also show that {gamma}-radiation treatment was followed by the growth of dormant metastases in various organs including lung and intestine after 2-4 weeks of {gamma}-radiation treatment. When bioluminescence imaging indicated growth of tumor in organs in mice, we sacrificed the mice and repeat acquired bioluminescence imaging after repeatedly. These images presented tumor growth locations exactly in organs. Because metastatic tumor candidates have morphology of foci, biopsies were performed for histological analysis or PCR analysis to confirm metastases. In most foci, histological analysis indicated several features of typical cancer tissue and PCR analysis showed present of fLuc gene in metastases. Detection of fLuc gene in metastases indicated these foci were originated from primary C6-TL xenografts, and the results suggest that {gamma}-radiation could promote metastasis in vivo as well as in vitro system. Although we need to understand changes of intracellular signaling or physiological phenomena of the radiation-induced metastasis yet, these results also imply that {gamma}-radiation treatment only to cancer patients need to pay attention carefully, and development of new

  3. Immunohistochemical study of p53 overexpression in radiation-induced colon cancers

    International Nuclear Information System (INIS)

    Minami, Kazunori; Hayashi, Nobuyuki; Mokarim, A.; Matsuzaki, Sumihiro; Ito, Masahiro; Sekine, Ichiro.

    1998-01-01

    The expressions of p53 and proliferating cell nuclear antigen (PCNA) were studied immunohistochemically from paraffin sections of 7 cases (9 lesions) of radiation-induced colon cancer and 42 cases of spontaneous colon cancer. Age distribution of radiation-induced and spontaneous colon cancer were 68.1 years (range, 56 to 77 years) and 67.4 years (range, 31 to 85 years), respectively. Among the radiation-induced colon cancers, there were 3 lesions of mucinous carcinoma (33%), a much higher than found for spontaneous mucinous cancer. Immunohistochemically, p53 protein expression was detected in 7/9 (78%) of radiation-induced cancers and in 23/42 (55%) of spontaneous colon cancers. χ 2 analysis found no significant differences between radiation-induced and spontaneous colon cancers in age distribution or p53-positive staining for frequency, histopathology, or Dukes'' classification. In radiation colitis around the cancers including aberrant crypts, spotted p53 staining and abnormal and scattered PCNA-positive staining were observed. In histologically normal cells, p53 staining was almost absent and PCNA-positive staining was regularly observed in the lower half of the crypt. In radiation colitis including aberrant glands, cellular proliferation increased and spotted p53 expression was observed. This study suggests that radiation colitis and aberrant glands might possess malignant potential and deeply associate with carcinogenesis of radiation-induced colon cancer. (author)

  4. Microfabricated electrochemical sensor for the detection of radiation-induced DNA damage

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.; Rivas, G.; Ozsoz, M.; Grant, D.H.; Cai, X.; Parrado, C. [New Mexico State Univ., Las Cruces, NM (United States)

    1997-04-01

    An electrochemical biosensor protocol for the detection of radiation-induced DNA damage is described. The procedure employs a dsDNA-coated screen-printed electrode and relies on changes in the guanine-DNA oxidation signal upon exposure to ultraviolet radiation. The decreased signal is ascribed primarily to conformational changes in the DNA and to the photoconversion of the guanine-DNA moiety to a nonelectroactive monomeric base product. Factors influencing the response of these microfabricated DNA sensors, such as irradiation time, wavelength, and distance, are explored, and future prospects are discussed. Similar results are given for the use of bare strip electrodes in connection with irradiated DNA solutions. 8 refs., 4 figs.

  5. A report on radiation-induced gliomas

    International Nuclear Information System (INIS)

    Salvati, M.; Artico, M.; Caruso, R.; Rocchi, G.; Orlando, E.R.; Nucci, F.

    1991-01-01

    Radiation-induced gliomas are uncommon, with only 73 cases on record to date. The disease that most frequently occasioned radiation therapy has been acute lymphoblastic leukemia (ALL). Three more cases are added here, two after irradiation for ALL and one after irradiation for tinea capitis. In a review of the relevant literature, the authors stress the possibility that the ALL-glioma and the retinoblastoma-glioma links point to syndromes in their own right that may occur without radiation therapy.56 references

  6. Epigenetic Analysis of Heavy-ion Radiation Induced Bystander Effects in Mice

    Science.gov (United States)

    Zhang, Meng; Sun, Yeqing; Cui, Changna; Xue, Bei

    Abstract: Radiation-induced bystander effect was defined as the induction of damage in neighboring non-hit cells by signals released from directly-irradiated cells. Recently, low dose of high LET radiation induced bystander effects in vivo have been reported more and more. It has been indicated that radiation induced bystander effect was localized not only in bystander tissues but also in distant organs. Genomic, epigenetic and proteomics plays significant roles in regulating heavy-ion radiation stress responses in mice. To identify the molecular mechanism that underlies bystander effects of heavy-ion radiation, the male Balb/c and C57BL mice were exposed head-only to 40, 200, 2000mGy dose of (12) C heavy-ion radiation, while the rest of the animal body was shielded. Directly radiation organ ear and the distant organ liver were detected on 1h, 6h, 12h and 24h after radiation, respectively. Methylation-sensitive amplification polymorphism (MSAP) was used to monitor the level of polymorphic genomic DNA methylation changed with dose and time effects. The results show that heavy-ion irradiated mouse head could induce genomic DNA methylation changes significantly in both the directly radiation organ ear and the distant organ liver. The percent of DNA methylation changes were time-dependent and tissue-specific. Demethylation polymorphism rate was highest separately at 1 h in 200 mGy and 6 h in 2000 mGy after irradiation. The global DNA methylation changes tended to occur in the CG sites. The results illustrated that genomic methylation changes of heavy ion radiation-induced bystander effect in liver could be obvious 1 h after radiation and achieved the maximum at 6 h, while the changes could recover gradually at 12 h. The results suggest that mice head exposed to heavy-ion radiation can induce damage and methylation pattern changed in both directly radiation organ ear and distant organ liver. Moreover, our findings are important to understand the molecular mechanism of

  7. Radiation-induced conductivity of polynaphthoyl benzimidazole

    Energy Technology Data Exchange (ETDEWEB)

    Tiutnev, A P; Berlin, A M; Saenko, V S; Rusanov, A L; Korshak, V V

    1985-01-01

    The nonstationary radiation-induced conductivity of polynaphthoyl benzimidazole, synthesized by single-stage high-temperature catalytic polycondensation, is investigated experimentally. It is shown that the radiation-induced conductivity of this material is characterized by an anomalous (non-Gaussian) transfer of excess charge carriers. The activation energy of the delayed component (0.1 ms after pulse termination) is determined to be 0.12 eV; the volt-ampere characteristic of this component is nonlinear, with the coefficient of nonlinearity increasing with the intensity of the external electric field. Experimental results are interpreted on the basis of the phenomenological theory of jump conductivity proposed by Zviagin. 15 references.

  8. Ubiquitin-dependent system controls radiation induced apoptosis

    International Nuclear Information System (INIS)

    Delic, J.; Magdelenat, H.; Glaisner, S.; Magdelenat, H.; Maciorowski, Z.

    1997-01-01

    The selective proteolytic pathway, dependent upon 'N-end rule' protein recognition/ubiquitination and on the subsequent proteasome dependent processing of ubiquitin conjugates, operates in apoptosis induced by γ-irradiation. The proteasome inhibitor peptide aldehyde, MG132, efficiently induced apoptosis and was also able (at doses lower than those required for apoptosis induction) to potentiate apoptosis induced by DNA damage. Its specificity is suggested by the induction of the ubiquitin (UbB and UbC) and E1 (ubiquitin activating enzyme) genes and by an altered ubiquitination pattern. More selectively, a di-peptide competitor of the 'N-end rule' of ubiquitin dependent protein processing inhibited radiation induced apoptosis. This inhibition is also followed by an altered ubiquitination pattern and by activation of Poly (ADP-ribose) polymerase (PARP). These data strongly suggest that early apoptosis radiation induced events are controlled by ubiquitin-dependent proteolytic processing. (author)

  9. Radiation-induced cancer in Japan

    International Nuclear Information System (INIS)

    Yamashita, Shoji; Sekizuka, Eiichi; Yamashita, Hisao; Takami, Akira; Kubo, Atsushi

    2001-01-01

    Results of two questionnaire surveys on radiation-induced malignant tumors conducted in 1977 and 1984 in Japan are briefly summarized. A total of 234 universities and general hospitals (139 in 1977, and 95 in 1984) responded and provided data from 1945 to 1977 and from 1978 to 1984. The number of patients with benign disease who developed secondary malignant tumors following radiation therapy was 150 in the first survey (1977) and 86 in the second survey (1984). The underlying benign diseases of these patients included tuberculous lymphadenitis, skin disease, hemangioma, and thyroid disease, and the most frequent radiation-induced malignant tumors in these patients were malignant tumors of the pharynx (80), cancer of the larynx (26), malignant tumors of the thyroid gland (22), cancer of the esophagus (219), and skin cancer (21). In patients with head and neck diseases the highest correlation between underlying benign disease and radiation-induced malignant tumors was between cervical tuberculous lymphadenitis and tumors of the pharynx (67 patients), followed by cancer of the larynx (19), and malignant tumors of the thyroid gland (11). There were also correlations between thyroid disease and malignant tumors of the thyroid gland (8 patients), hemangioma and skin cancer (7), and skin disease and skin cancer (8). The ratio of the observed values to predicted values (O/E ratio) in these patients was highest for cancer of the pharynx (118), followed by cancer of the parotid gland (42), skin cancer (31), cancer of the esophagus (22), malignant tumors of the thyroid gland (21), and cancer of the larynx (16). The number of patients with malignant tumors who developed secondary malignant tumors following radiation therapy was 140 in 1977 and 108 in 1984, and the underlying malignant tumors in these patients included tumors of the uterus (106), breast (32), and head and neck (80). The most frequent secondary malignant tumors were soft tissue tumors, followed by leukemia, and

  10. Radiation induced liver disease: A clinical update

    International Nuclear Information System (INIS)

    Benson, R.; Madan, R.; Chander, S.; Kilambi, R.

    2016-01-01

    Radiation-induced liver disease (RILD) or radiation hepatitis is a sub-acute form of liver injury due to radiation. It is one of the most dreaded complications of radiation which prevents radiation dose escalation and re irradiation for hepatobiliary or upper gastrointestinal malignancies. This complication should be kept in mind whenever a patient is planned for irradiation of these malignancies. Although, incidence of RILD is decreasing due to better knowledge of liver tolerance, improved investigation modalities and modern radiation delivery techniques, treatment options are still limited. In this review article, we have focussed on pathophysiology, risk factors, prevention and management of RILD

  11. Radiation-induced meningiomas in pediatric patients

    International Nuclear Information System (INIS)

    Moss, S.D.; Rockswold, G.L.; Chou, S.N.; Yock, D.; Berger, M.S.

    1988-01-01

    Radiation-induced meningiomas rarely have latency periods short enough from the time of irradiation to the clinical presentation of the tumor to present in the pediatric patient. Three cases of radiation-induced intracranial meningiomas in pediatric patients are presented. The first involved a meningioma of the right frontal region in a 10-year-old boy 6 years after the resection and irradiation of a 4th ventricular medulloblastoma. Review of our pediatric tumor cases produced a second case of a left temporal fossa meningioma presenting in a 15-year-old boy with a history of irradiation for retinoblastoma at age 3 years and a third case of a right frontoparietal meningioma in a 15-year-old girl after irradiation for acute lymphoblastic leukemia. Only three cases of meningiomas presenting in the pediatric age group after radiation therapy to the head were detected in our review of the literature

  12. 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

  13. Radiation induced oral mucositis

    Directory of Open Access Journals (Sweden)

    P S Satheesh Kumar

    2009-01-01

    Full Text Available Patients receiving radiotherapy or chemotherapy will receive some degree of oral mucositis The incidence of oral mucositis was especially high in patients: (i With primary tumors in the oral cavity, oropharynx, or nasopharynx; (ii who also received concomitant chemotherapy; (iii who received a total dose over 5,000 cGy; and (iv who were treated with altered fractionation radiation schedules. Radiation-induced oral mucositis affects the quality of life of the patients and the family concerned. The present day management of oral mucositis is mostly palliative and or supportive care. The newer guidelines are suggesting Palifermin, which is the first active mucositis drug as well as Amifostine, for radiation protection and cryotherapy. The current management should focus more on palliative measures, such as pain management, nutritional support, and maintenance, of good oral hygiene

  14. Induced Compton scattering effects in radiation transport approximations

    International Nuclear Information System (INIS)

    Gibson, D.R. Jr.

    1982-01-01

    In this thesis the method of characteristics is used to solve radiation transport problems with induced Compton scattering effects included. The methods used to date have only addressed problems in which either induced Compton scattering is ignored, or problems in which linear scattering is ignored. Also, problems which include both induced Compton scattering and spatial effects have not been considered previously. The introduction of induced scattering into the radiation transport equation results in a quadratic nonlinearity. Methods are developed to solve problems in which both linear and nonlinear Compton scattering are important. Solutions to scattering problems are found for a variety of initial photon energy distributions

  15. Radiation-induced pseudotumor following therapy for soft tissue sarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Lacey F.; Kransdorf, Mark J. [Mayo Clinic, Department of Radiology, Jacksonville, FL (United States); Buskirk, Steven J. [Mayo Clinic, Department of Radiation Oncology, Jacksonville, FL (United States); O' Connor, Mary I. [Mayo Clinic, Department of Orthopedic Surgery, Jacksonville, FL (United States); Menke, David M. [Mayo Clinic, Department of Pathology, Jacksonville, FL (United States)

    2009-06-15

    The purpose of this study was to describe the prevalence and imaging appearance of radiation induced pseudotumors in patients following radiation therapy for extremity soft tissue sarcomas. We retrospectively reviewed the serial magnetic resonance (MR) images of 24 patients following radiation therapy for extremity soft tissue sarcomas. A total of 208 exams were reviewed (mean, 8.7 exams per patient) and included all available studies following the start of radiation therapy. Exams were analyzed for the identification of focal signal abnormalities within the surgical bed suggesting local tumor recurrence. Histopathologic correlation was available in nine patients suspected of having local tumor recurrence. Additional information recorded included patient demographics, tumor type and location, radiation type, and dose. The study group consisted of 12 men and 12 women, having an average age of 63 years (range, 39-88 years). Primary tumors were malignant fibrous histiocytoma (n = 13), leiomyosarcoma (n = 6), liposarcoma (n = 3), synovial sarcoma (n = 1), and extraskeletal chondrosarcoma (n = 1). All lesions were high-grade sarcomas, except for two myxoid liposarcomas. Average patient radiation dose was 5,658 cGy (range, 4,500-8,040 cGy). Average follow-up time was 63 months (range, 3-204 months). Focal signal abnormalities suggesting local recurrence were seen in nine (38%) patients. Three of the nine patients with these signal abnormalities were surgically proven to have radiation-induced pseudotumor. The pseudotumors developed between 11 and 61 months following the initiation of radiation therapy (mean, 38 months), with an average radiation dose of 5,527 cGy (range, 5,040-6,500 cGy). MR imaging demonstrated a relatively ill-defined ovoid focus of abnormal signal and intense heterogeneous enhancement with little or no associated mass effect. MR imaging of radiation-induced pseudotumor typically demonstrates a relatively ill-defined ovoid mass-like focus of intense

  16. Radiation technology and feed production

    International Nuclear Information System (INIS)

    Ershov, B.G.

    1986-01-01

    The use of radiation technology to prepare feeds and feed additions for cattle of non-feed vegetable blends is considered.Physicochemical foundations of radiation-chemical processes, possibilities of the use of various radiation devices are given. Data on practical realization of the technology are presented and prospects of its introduction to solve the tasks put forward by the USSR program on feed production are analyzed

  17. Photochemically induced carbon dioxide production as a mechanism for carbon loss from plant litter in arid ecosystems

    Science.gov (United States)

    Brandt, L. A.; Bohnet, C.; King, J. Y.

    2009-06-01

    We investigated the potential for abiotic mineralization to carbon dioxide (CO2) via photodegradation to account for carbon (C) loss from plant litter under conditions typical of arid ecosystems. We exposed five species of grass and oak litter collected from arid and mesic sites to a factorial design of ultraviolet (UV) radiation (UV pass, UV block), and sterilization under dry conditions in the laboratory. UV pass treatments produced 10 times the amount of CO2 produced in UV block treatments. CO2 production rates were unaffected by litter chemistry or sterilization. We also exposed litter to natural solar radiation outdoors on clear, sunny days close to the summer solstice at midlatitudes and found that UV radiation (280-400 nm) accounted for 55% of photochemically induced CO2 production, while shortwave visible radiation (400-500 nm) accounted for 45% of CO2 production. Rates of photochemically induced CO2 production on a per-unit-mass basis decreased with litter density, indicating that rates depend on litter surface area. We found no evidence for leaching, methane production, or facilitation of microbial decomposition as alternative mechanisms for significant photochemically induced C loss from litter. We conclude that abiotic mineralization to CO2 is the primary mechanism by which C is lost from litter during photodegradation. We estimate that CO2 production via photodegradation could be between 1 and 4 g C m-2 a-1 in arid ecosystems in the southwestern United States. Taken together with low levels of litter production in arid systems, photochemical mineralization to CO2 could account for a significant proportion of annual carbon loss from litter in arid ecosystems.

  18. Previous 60-Co radiation from Paratrygon aiereba mucus induces the production of highly responsive antibodies and a better immune response in mice

    Energy Technology Data Exchange (ETDEWEB)

    Thomazi, Gabriela Ortega Coelho; Alves, Glaucie Jussilane; Turíbio, Thompson de Oliveira; Rocha, André Moreira; Aires, Raquel da Silva; Jácome, Larissa Barros Silvestre; Spencer, Patrick Jack, E-mail: gabiortegacoelho@usp.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil). Centro de Biotecnologia; Costa, Andrea da; Rodrigues, Jaqueline Pollizeli; Galisteo Júnior, Andrés Jimenez; Andrade Júnior, Heitor Franco de, E-mail: hfandrad@usp.br, E-mail: raquelaires@itpacporto.com.br [Universidade de São Paulo (USP), São Paulo, SP (Brazil). Laboratório de Protozoologia; Seibert, Carla Simone, E-mail: seibertcs@uft.edu.br [Universidade Federal do Tocantins (UFT), Porto Nacional, TO (Brazil)

    2017-07-01

    Wounds from stinging freshwater stingrays are painful, difficult to heal and cause extensive necrosis and systemic phenomena. The treatment is symptomatic, of low efficiency and there is no therapy, which causes more suffering to the injured. This study aimed to evaluate the immune response induced by the native or irradiated by 60-Co gamma from Paratrygon aiereba mucus. IPEN’s Committee on Ethics in the Use of Animals (n.º126/2013) and lanes captured under license from the Chico Mendes Institute for Biodiversity Conservation (n.º6781-1/2014) approved this research. For the assays, sera from Swiss mice previously immunized against native or irradiated mucus were used. The proliferation of splenic B cells in response to mucus was evaluated by the In Vitro Induced Antibody Production method and serum and splenic cytokines were also quantified. Our data demonstrate that the irradiated mucus of P. aiereba induces greater production of antibodies and more immunological memory in the mice. Spleen cells from animals immunized against irradiated mucus produced IFN-γ, TNF-α and IL-10, and serum TNF-α (immunized group against irradiated mucus) and IL-6 and IL-17 (immunized group against native mucus). The results corroborate the use of ionizing radiation, with production of highly responsive antibodies and better immune response, besides proving that Paratrygon aiereba mucus is capable of stimulating cellular and humoral adaptive immune response, contributing to the continuity of associated investigations. (author)

  19. Previous 60-Co radiation from Paratrygon aiereba mucus induces the production of highly responsive antibodies and a better immune response in mice

    International Nuclear Information System (INIS)

    Thomazi, Gabriela Ortega Coelho; Alves, Glaucie Jussilane; Turíbio, Thompson de Oliveira; Rocha, André Moreira; Aires, Raquel da Silva; Jácome, Larissa Barros Silvestre; Spencer, Patrick Jack

    2017-01-01

    Wounds from stinging freshwater stingrays are painful, difficult to heal and cause extensive necrosis and systemic phenomena. The treatment is symptomatic, of low efficiency and there is no therapy, which causes more suffering to the injured. This study aimed to evaluate the immune response induced by the native or irradiated by 60-Co gamma from Paratrygon aiereba mucus. IPEN’s Committee on Ethics in the Use of Animals (n.º126/2013) and lanes captured under license from the Chico Mendes Institute for Biodiversity Conservation (n.º6781-1/2014) approved this research. For the assays, sera from Swiss mice previously immunized against native or irradiated mucus were used. The proliferation of splenic B cells in response to mucus was evaluated by the In Vitro Induced Antibody Production method and serum and splenic cytokines were also quantified. Our data demonstrate that the irradiated mucus of P. aiereba induces greater production of antibodies and more immunological memory in the mice. Spleen cells from animals immunized against irradiated mucus produced IFN-γ, TNF-α and IL-10, and serum TNF-α (immunized group against irradiated mucus) and IL-6 and IL-17 (immunized group against native mucus). The results corroborate the use of ionizing radiation, with production of highly responsive antibodies and better immune response, besides proving that Paratrygon aiereba mucus is capable of stimulating cellular and humoral adaptive immune response, contributing to the continuity of associated investigations. (author)

  20. Mechanistic issues for modeling radiation-induced segregation

    International Nuclear Information System (INIS)

    Simonen, E.P.; Bruemmer, S.M.

    1993-03-01

    Model calculations of radiation-induced chromium depletion and radiation-induced nickel enrichment at grain boundaries are compared to measured depletions and enrichments. The model is calibrated to fit chromium depletion in commercial purity 304 stainless steel irradiated in boiling water reactor (BWR) environments. Predicted chromium depletion profiles and the dose dependence of chromium concentration at grain boundaries are in accord with measured trends. Evaluation of chromium and nickel profiles in three neutron, and two ion, irradiation environments reveal significant inconsistencies between measurements and predictions

  1. Umbelliferone suppresses radiation induced DNA damage and apoptosis in hematopoietic cells of mice

    International Nuclear Information System (INIS)

    Jayakumar, S.; Bhilwade, H.N.; Chaubey, R.C.

    2012-01-01

    Radiotherapy is one of the major modes of treatment for different types of cancers. But the success of radiotherapy is limited by injury to the normal cells. Protection of the normal cells from radiation damage by radioprotectors can increase therapeutic efficiency. These radioprotectors can also be used during nuclear emergency situations. Umbelliferone (UMB) is a wide spread natural product of the coumarin family. It occurs in many plants from the Apiaceae family. In the present study radioprotective effect of UMB was investigated in vitro and in vivo. Anti genotoxic effect of Umbelliferone was tested by treating the splenic lymphocytes with various doses of UMB (6.5 μM - 50 μM) prior to radiation (6Gy) exposure. After the radiation exposure, extent of DNA damage was assessed by comet assay at 5 mm and two hours after radiation exposure. At both the time points, it was observed that the pretreatment of UMB reduced the radiation induced DNA damage to a significant extent in comparison to radiation control. UMB pretreatment also significantly reduced the radiation induced apoptosis enumerated by propidium iodide staining assay. Results of clonogenic survival assay using intestinal cell line showed that pretreatment with UMB significantly protected against radiation induced loss of colony forming units. To assess the anti genotoxic role of umbelliferone in vivo two different doses of UMB (20 mg/Kg and 40 mg/Kg of body weight) were injected into Swiss mice or with vehicle and exposed to radiation. Thirty minutes after the radiation comet assay was performed in peripheral leukocytes. Frequency of micro nucleated erythrocytes was scored in bone marrow cells. It was observed that UMB alone did not cause any significant increase in DNA damage in comparison to control. Animals which are exposed to radiation alone showed significant increase in DNA damage and micronuclei frequency. But animals treated with UMB prior to the radiation exposure showed significant decrease

  2. 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)

  3. Mechanisms of radiation-induced neoplastic cell transformation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, T.C.H.; Tobias, C.A.

    1984-04-01

    Studies with cultured mammalian cells demonstrated clearly that radiation can transform cells directly and can enhance the cell transformation by oncogenic DNA viruses. In general, high-LET heavy-ion radiation can be more effective than X and gamma rays in inducing neoplastic cell transformation. Various experimental results indicate that radiation-induced DNA damage, most likely double-strand breaks, is important for both the initiation of cell transformation and for the enhancement of viral transformation. Some of the transformation and enhancement lesions can be repaired properly in the cell, and the amount of irrepairable lesions produced by a given dose depends on the quality of radiation. An inhibition of repair processes with chemical agents can increase the transformation frequency of cells exposed to radiation and/or oncogenic viruses, suggesting that repair mechanisms may play an important role in the radiation transformation. The progression of radiation-transformed cells appears to be a long and complicated process that can be modulated by some nonmutagenic chemical agents, e.g., DMSO. Normal cells can inhibit the expression of transforming properties of tumorigenic cells through an as yet unknown mechanism. The progression and expression of transformation may involve some epigenetic changes in the irradiated cells. 38 references, 15 figures, 1 table.

  4. Mechanisms of radiation-induced neoplastic cell transformation

    International Nuclear Information System (INIS)

    Yang, T.C.H.; Tobias, C.A.

    1984-04-01

    Studies with cultured mammalian cells demonstrated clearly that radiation can transform cells directly and can enhance the cell transformation by oncogenic DNA viruses. In general, high-LET heavy-ion radiation can be more effective than X and gamma rays in inducing neoplastic cell transformation. Various experimental results indicate that radiation-induced DNA damage, most likely double-strand breaks, is important for both the initiation of cell transformation and for the enhancement of viral transformation. Some of the transformation and enhancement lesions can be repaired properly in the cell, and the amount of irrepairable lesions produced by a given dose depends on the quality of radiation. An inhibition of repair processes with chemical agents can increase the transformation frequency of cells exposed to radiation and/or oncogenic viruses, suggesting that repair mechanisms may play an important role in the radiation transformation. The progression of radiation-transformed cells appears to be a long and complicated process that can be modulated by some nonmutagenic chemical agents, e.g., DMSO. Normal cells can inhibit the expression of transforming properties of tumorigenic cells through an as yet unknown mechanism. The progression and expression of transformation may involve some epigenetic changes in the irradiated cells. 38 references, 15 figures, 1 table

  5. Radiation induced glioblastoma. A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Naoki; Kayama, Takamasa; Sakurada, Kaori; Saino, Makoto; Kuroki, Akira [Yamagata Univ. (Japan). School of Medicine

    2000-05-01

    We report a surgical case of a 54-year-old woman with a radiation induced glioblastoma. At the age of 34, the patient was diagnosed to have a non-functioning pituitary adenoma. It was partially removed followed by 50 Gy focal irradiation with a 5 x 5 cm lateral opposed field. Twenty years later, she suffered from rapidly increasing symptoms such as aphasia and right hemiparesis. MRI showed a large mass lesion in the left temporal lobe as well as small mass lesions in the brain stem and the right medial temporal lobe. These lesions situated within the irradiated field. Magnetic resonance spectroscopy revealed relatively high lactate signal and decreased N-acetyl aspartate, choline, creatine and phosphocreatine signals. Increased lactate signal meant anaerobic metabolism that suggested the existence of a rapidly growing malignant tumor. Thus, we planned surgical removal of the left temporal lesion with the diagnosis of a radiation induced malignant glioma. The histological examination revealed a glioblastoma with radiation necrosis. MIB-1 staining index was 65%. Postoperatively, her symptoms improved, but she died from pneumonia 1 month after the surgery. A autopsy was obtained. The lesion of the left temporal lobe was found to have continuity to the lesion in the midbrain, the pons and the right temporal lobe as well. High MIB-1 staining index suggested that a radiation induced glioblastoma had high proliferative potential comparing with a de novo and secondary glioblastoma. (author)

  6. Indomethacin attenuation of radiation-induced hyperthermia does not modify radiation-induced motor hypoactivity

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, J.L.; Kandasamy, S.B.; Harris, A.H.; Davis, H.D.; Landauer, M.R. [Armed Forces Radiobiology Research Inst., Bethesda, MD (United States)

    1996-09-01

    Exposure of rats to 5-10 Gy of ionizing radiation produces hyperthermia and reduces motor activity. Previous studies suggested that radiation-induced hyperthermia results from a relatively direct action on the brain and is mediated by prostaglandins. To test the hypothesis that hypoactivity may be, in part, a thermoregulatory response to this elevation in body temperature, adult male rats were given indomethacin (0.0, 0.5, 1.0, and 3.0 mg/kg, intraperitoneally), a blocker of prostaglandin synthesis, and were either irradiated (LINAC 18.6 MeV (nominal) high-energy electrons, 10 Gy at 10 Gy/min, 2.8 {mu}sec pulses at 2 Hz) or sham-irradiated. The locomotor activity of all rats was then measured for 30 min in a photocell monitor for distance traveled and number of vertical movements. Rectal temperatures of irradiated rats administered vehicle only were elevated by 0.9{+-}0.2degC at the beginning and the end of the activity session. Although indomethacin, at the two higher doses tested, attenuated the hyperthermia in irradiated rats by 52-75%, it did not attenuate radiation-induced reductions in motor activity. These results indicate that motor hypoactivity after exposure to 10 Gy of high-energy electrons is not due to elevated body temperature or to the increased synthesis of prostaglandins. (author)

  7. Indomethacin attenuation of radiation-induced hyperthermia does not modify radiation-induced motor hypoactivity

    International Nuclear Information System (INIS)

    Ferguson, J.L.; Kandasamy, S.B.; Harris, A.H.; Davis, H.D.; Landauer, M.R.

    1996-01-01

    Exposure of rats to 5-10 Gy of ionizing radiation produces hyperthermia and reduces motor activity. Previous studies suggested that radiation-induced hyperthermia results from a relatively direct action on the brain and is mediated by prostaglandins. To test the hypothesis that hypoactivity may be, in part, a thermoregulatory response to this elevation in body temperature, adult male rats were given indomethacin (0.0, 0.5, 1.0, and 3.0 mg/kg, intraperitoneally), a blocker of prostaglandin synthesis, and were either irradiated (LINAC 18.6 MeV (nominal) high-energy electrons, 10 Gy at 10 Gy/min, 2.8 μsec pulses at 2 Hz) or sham-irradiated. The locomotor activity of all rats was then measured for 30 min in a photocell monitor for distance traveled and number of vertical movements. Rectal temperatures of irradiated rats administered vehicle only were elevated by 0.9±0.2degC at the beginning and the end of the activity session. Although indomethacin, at the two higher doses tested, attenuated the hyperthermia in irradiated rats by 52-75%, it did not attenuate radiation-induced reductions in motor activity. These results indicate that motor hypoactivity after exposure to 10 Gy of high-energy electrons is not due to elevated body temperature or to the increased synthesis of prostaglandins. (author)

  8. Radiation induces aerobic glycolysis through reactive oxygen species

    International Nuclear Information System (INIS)

    Zhong, Jim; Rajaram, Narasimhan; Brizel, David M.; Frees, Amy E.; Ramanujam, Nirmala; Batinic-Haberle, Ines; Dewhirst, Mark W.

    2013-01-01

    Background and purpose: Although radiation induced reoxygenation has been thought to increase radiosensitivity, we have shown that its associated oxidative stress can have radioprotective effects, including stabilization of the transcription factor hypoxia inducible factor 1 (HIF-1). HIF-1 is known to regulate many of the glycolytic enzymes, thereby promoting aerobic glycolysis, which is known to promote treatment resistance. Thus, we hypothesized that reoxygenation after radiation would increase glycolysis. We previously showed that blockade of oxidative stress using a superoxide dismutase (SOD) mimic during reoxygenation can downregulate HIF-1 activity. Here we tested whether concurrent use of this drug with radiotherapy would reduce the switch to a glycolytic phenotype. Materials and methods: 40 mice with skin fold window chambers implanted with 4T1 mammary carcinomas were randomized into (1) no treatment, (2) radiation alone, (3) SOD mimic alone, and (4) SOD mimic with concurrent radiation. All mice were imaged on the ninth day following tumor implantation (30 h following radiation treatment) following injection of a fluorescent glucose analog, 2-[N-(7-nitrobenz-2-oxa-1,3-diaxol-4-yl)amino]-2-deoxyglucose (2-NBDG). Hemoglobin saturation was measured by using hyperspectral imaging to quantify oxygenation state. Results: Mice treated with radiation showed significantly higher 2-NBDG fluorescence compared to controls (p = 0.007). Hemoglobin saturation analysis demonstrated reoxygenation following radiation, coinciding with the observed increase in glycolysis. The concurrent use of the SOD mimic with radiation demonstrated a significant reduction in 2-NBDG fluorescence compared to effects seen after radiation alone, while having no effect on reoxygenation. Conclusions: Radiation induces an increase in tumor glucose demand approximately 30 h following therapy during reoxygenation. The use of an SOD mimic can prevent the increase in aerobic glycolysis when used

  9. Radiation-induced amorphization of intermetallic compounds: A molecular-dynamics study of CuTi and Cu4Ti3

    International Nuclear Information System (INIS)

    Lam, N.Q.; Okamoto, P.R.; Sabochick, M.J.

    1991-06-01

    In the present paper, important results of our recent computer simulation of radiation-induced amorphization in the ordered compounds CuTi and Cu 4 Ti 3 are summarized. The energetic, structural, thermodynamic and mechanical responses of these intermetallics during chemical disordering, point-defect production and heating were simulated, using molecular dynamics and embedded-atom potentials. From the atomistic details obtained, the critical role of radiation-induced structural disorder in driving the crystalline-to-amorphous phase transformation is discussed. 25 refs., 4 figs

  10. Radiation-induced mucositis pain in laryngeal cancer

    International Nuclear Information System (INIS)

    Takahashi, Atsuhito; Shoji, Kazuhiko; Iki, Takehiro; Mizuta, Masanobu; Matsubara, Mami

    2009-01-01

    Radiation therapy in those with head and neck malignancies often triggers painful mucositis poorly controlled by nonsteroidal antiinflammatory drugs (NSAIDs). To better understand how radiation-induced pain develops over time, we studied the numerical rating scale (NRS 0-5) pain scores from 32 persons undergoing radiation therapy of 60-72 Gy for newly diagnosed laryngeal cancer. The degree of mucositis was evaluated using Common Terminology Criteria for Adverse Events version3.0 (CTCAE v3.0). We divided the 32 into a conventional fractionation (CF) group of 14 and a hyperfractionation (HF) group of 18, and further divided laryngeal cancer into a small-field group of 23 and a large-field group of 9. The mucositis pain course was similar in CF and HF, but mucositis pain was severer in the HF group, which also required more NSAIDs. Those in the large-field group had severer pain and mucositis and required more NSAIDs than those in the small-field group. We therefore concluded that small/large-field radiation therapy, rather fractionation type, was related to the incidence of radiation-induced mucositis pain. (author)

  11. Radiation-induced soft-tissue and bone sarcoma

    International Nuclear Information System (INIS)

    Kim, J.H.; Chu, F.C.; Woodard, H.Q.; Melamed, R.; Huvos, A.; Cantin, J.

    1978-01-01

    From the records of Memorial Hospital of the past 50 years, 47 cases with an established diagnosis of radiation-induced sarcoma were identified and divided into two groups: the first included 20 cases of soft-tissue sarcoma arising from irradiated tissues, and the second comprised 27 cases of bone sarcoma arising from normal bones in the irradiated field. Medians for the latent periods from irradiation to diagnosis of bone and soft-tissue sarcoma were 11 and 12, years, respectively. In bone sarcomas, the latent period was longer after larger radiation doses and children appeared to be more susceptible to cancer induction than adults. Criteria for establishing the diagnosis of radiation-induced sarcoma and the magnitude of the risk of bone sarcoma are discussed

  12. Radiation-induced ηe-modes

    International Nuclear Information System (INIS)

    Shukla, P.K.; Yu, M.Y.

    1990-01-01

    Impurity radiation in a plasma can cause not only static instabilities, but also dynamic instabilities related to the drift and acoustic waves. Radiative instabilities are of much interest because they are associated with relatively high frequency and short wavelength fluctuations, which have been suspected to be responsible for anomalous electron energy transport in tokamak edge plasmas. In this paper, we consider radiation-induced η e instabilities, taking into account electrostatic effects as well as density and temperature inhomogeneities. Also included are the effects of finite gyroradius and dissipation. It is found that the latter can cause strong linear coupling between the modes of interest. The resulting instabilities can have larger growth rates than the static radiative instability. Analytical expressions for the growth rates and instability regimes are given for the limiting cases of practical interest. In particular, it is shown that the η e -mode can couple to both radiation and dissipation to cause resistive instabilities. The parameter regimes of the original radiative as well as the dissipative modes are thereby broadened and shifted because of the interaction. (author) 3 refs

  13. Modification of radiation-induced DNA lesions by oxygen

    International Nuclear Information System (INIS)

    Meyn, R.E.; Jenkins, W.T.

    1984-01-01

    The efficiency of DNA strand break production by radiation under aerated and hypoxic conditions was determined in CHO cells using the technique of alkaline elution. The resulting oxygen enhancement ratio was surprisingly high, 7.8. When the pH of the elution was increased from 12.1, the normally used pH, to 12.8, a substantial increase in the strand breaks produced in the hypoxic cells was observed, resulting in an OER of 4.8. This difference in susceptibility of DNA strand break detection as a function of pH suggested a difference in the type of lesions produced in DNA when irradiated under aerated and hypoxic conditions. Further experiments to examine the DNA-protein crosslinks produced by radiation suggested that the apparent lower level of strand breaks in hypoxic cells may be due to a higher level of DNA-protein crosslinks produced under hypoxic conditions. Thus, oxygen may not only act by modifying the quantity of radiation-induced DNA lesions but may also cause qualitative changes. If the different types of DNA lesions have different contributions to lethality, the OER for cell survival may represent a complex composite of these changes at the molecular level

  14. Radiation-emitting Electronic Product Codes

    Data.gov (United States)

    U.S. Department of Health & Human Services — This database contains product names and associated information developed by the Center for all products, both medical and non-medical, which emit radiation. It...

  15. UV radiation induced stress does not affect DMSP synthesis in the marine prymnesiophyte Emiliania huxleyi

    NARCIS (Netherlands)

    van Rijssel, M; Buma, A.G.J.

    2002-01-01

    A possible coupling between UV radiation (UVR; 280 to 400 nm) induced stress and the production of dimethylsulfoniopropionate (DMSP), the precursor of the climate-regulating gas dimethylsulfide (DMS), was investigated in the marine prymnesiophyte Emiliania huxleyi. To this end, axenic cultures of E.

  16. Radiation induced diffusion as a method to protect surface

    International Nuclear Information System (INIS)

    Baumvol, I.J.R.

    1980-01-01

    Radiation induced diffusion forms a coating adeherent and without interface on the surface of metalic substrates. This coating improves the behaviour of metal to corrosion and abrasion. The effect of radiation induced diffusion of tin and calcium on pure iron surface is described and analyzed in this work. (author) [pt

  17. Radiation-induced cancer

    International Nuclear Information System (INIS)

    Dutrillaux, B.; CEA Fontenay-aux-Roses, 92

    1998-01-01

    The induction of malignant diseases is one of the most concerning late effects of ionising radiation. A large amount of information has been collected form atomic bomb survivors, patients after therapeutic irradiation, occupational follow-up and accidentally exposed populations. Major uncertainties persist in the (very) low range i.e, population and workers radioprotection. A review of the biological mechanisms leading to cancer strongly suggests that the vast majority of radiation-induced malignancies arise as a consequence of recessive mutations can be unveiled by ageing, this process being possibly furthered by constitutional or acquired genomic instability. The individual risk is likely to be very low, probably because of the usual dose level. However, the magnitude of medical exposure and the reliance of our societies on nuclear industry are so high that irreproachable decision-making processes and standards for practice are inescapable. (author)

  18. Methylglyoxal-bis(guanylhydrazone), a polyamine analogue, sensitized γ-radiation-induced cell death in HL-60 leukemia cells Sensitizing effect of MGBG on γ-radiation-induced cell death.

    Science.gov (United States)

    Kim, Jin Sik; Lee, Jin; Chung, Hai Won; Choi, Han; Paik, Sang Gi; Kim, In Gyu

    2006-09-01

    Methylglyoxal-bis(guanylhydrazone) (MGBG), a polyamine analogue, has been known to inhibit the biosynthesis of polyamines, which are important in cell proliferation. We showed that MGBG treatment significantly affected γ-radiation-induced cell cycle transition (G(1)/G(0)→S→G(2)/M) and thus γ-radiation-induced cell death. As determined by micronuclei and comet assay, we showed that it sensitized the cytotoxic effect induced by γ-radiation. One of the reasons is that polyamine depletion by MGBG treatment did not effectively protect against the chemical (OH) or physical damage to DNA caused by γ-radiation. Through in vitro experiment, we confirmed that DNA strand breaks induced by γ-radiation was prevented more effectively in the presence of polyamines (spermine and spermidine) than in the absence of polyamines. MGBG also blocks the cell cycle transition caused by γ-radiation (G(2) arrest), which helps protect cells by allowing time for DNA repair before entry into mitosis or apoptosis, via the down regulation of cyclin D1, which mediates the transition from G(1) to S phase of cell cycle, and ataxia telangiectasia mutated, which is involved in the DNA sensing, repair and cell cycle check point. Therefore, the abrogation of G(2) arrest sensitizes cells to the effect of γ-radiation. As a result, γ-radiation-induced cell death increased by about 2.5-3.0-fold in cells treated with MGBG. However, exogenous spermidine supplement partially relieved this γ-radiation-induced cytotoxicity and cell death. These findings suggest a potentially therapeutic strategy for increasing the cytotoxic efficacy of γ-radiation.

  19. Evidence for Radiation-Induced Disseminated Intravascular Coagulation as a Major Cause of Radiation-Induced Death in Ferrets

    Energy Technology Data Exchange (ETDEWEB)

    Krigsfeld, Gabriel S.; Savage, Alexandria R.; Billings, Paul C.; Lin, Liyong; Kennedy, Ann R., E-mail: akennedy@mail.med.upenn.edu

    2014-03-15

    Purpose: The studies reported here were performed as part of a program in space radiation biology in which proton radiation like that present in solar particle events, as well as conventional gamma radiation, were being evaluated in terms of the ability to affect hemostasis. Methods and Materials: Ferrets were exposed to 0 to 2 Gy of whole-body proton or gamma radiation and monitored for 30 days. Blood was analyzed for blood cell counts, platelet clumping, thromboelastometry, and fibrin clot formation. Results: The lethal dose of radiation to 50% of the population (LD{sub 50}) of the ferrets was established at ∼1.5 Gy, with 100% mortality at 2 Gy. Hypocoagulability was present as early as day 7 postirradiation, with animals unable to generate a stable clot and exhibiting signs of platelet aggregation, thrombocytopenia, and fibrin clots in blood vessels of organs. Platelet counts were at normal levels during the early time points postirradiation when coagulopathies were present and becoming progressively more severe; platelet counts were greatly reduced at the time of the white blood cell nadir of 13 days. Conclusions: Data presented here provide evidence that death at the LD{sub 50} in ferrets is most likely due to disseminated intravascular coagulation (DIC). These data question the current hypothesis that death at relatively low doses of radiation is due solely to the cell-killing effects of hematopoietic cells. The recognition that radiation-induced DIC is the most likely mechanism of death in ferrets raises the question of whether DIC is a contributing mechanism to radiation-induced death at relatively low doses in large mammals.

  20. A case of radiation-induced osteosarcoma of the maxilla

    International Nuclear Information System (INIS)

    Tanaka, Rie; Asato, Ryo; Tanaka, Shinzo; Hiratsuka, Yasuyuki; Ito, Juichi

    2003-01-01

    Radiation-induced osteosarcoma in the head and neck region is very rare. A 68-year-old female, who had been treated with radiation for malignant lymphoma of the right maxillary sinus, presented with right cheek swelling. Imaging examinations demonstrated a huge mass occupying the right nasal cavity and paranasal sinuses. Total maxillectomy was performed, and the tumor was histologically diagnosed as osteosarcoma. Diagnosis and treatment for radiation-induced osteosarcoma in the head and neck is discussed. (author)

  1. A case of radiation-induced osteosarcoma of the maxilla

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Rie [Shimada City Hospital, Shizuoka (Japan); Asato, Ryo; Tanaka, Shinzo; Hiratsuka, Yasuyuki; Ito, Juichi [Kyoto Univ. (Japan). Faculty of Medicine

    2003-02-01

    Radiation-induced osteosarcoma in the head and neck region is very rare. A 68-year-old female, who had been treated with radiation for malignant lymphoma of the right maxillary sinus, presented with right cheek swelling. Imaging examinations demonstrated a huge mass occupying the right nasal cavity and paranasal sinuses. Total maxillectomy was performed, and the tumor was histologically diagnosed as osteosarcoma. Diagnosis and treatment for radiation-induced osteosarcoma in the head and neck is discussed. (author)

  2. [The occupational radiation-induced cataract in five industrial radiographers].

    Science.gov (United States)

    Benzarti Mezni, A; Loukil, I; Hriz, N; Kallel, K; Mlaiki, N; Ben Jemaâ, A

    2012-04-01

    The industrial uses of ionizing radiation in Tunisia are expanding, especially in industry and most particularly in the nondestructive testing of welds. Thus workers operating in the non-destructive testing of welds may develop a radiation-induced cataract varying in time to onset depending on the dose. To describe the characteristics of the radiation-induced cataract in patients exposed to ionizing radiation, determine the risk factors of radiation-induced cataracts. This was an anamnestic, clinical, and environmental study of five cases of radiation-induced cataract in workers employed in non-destructive testing of welds. This series of five cases had a mean age of 30.2 years and 5.53 years of work experience, ranging from 14 months to 15 years. All the patients were male and industrial radiographers specialized in nondestructive testing of welds. The average duration of exposure to ionizing radiation was 5.53 years. None of the patients had worn protective gear such as eye goggles. The ophthalmic check-up for the five special industrial radiographers showed punctuate opacities in three cases, punctiform opacities in one eye in one case, and phacosclerosis with bilateral lens multiple crystalline stromal opacities in a case of micro-lens opacities in both eyes with opalescence of both eyes in one case. These cataracts had been declared as occupational diseases. The value of a specialized ophthalmologic surveillance among these workers and the early diagnosis of lens opacities must be emphasized. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  3. Radiation-induced recurrent intestinal pseudo-obstruction

    International Nuclear Information System (INIS)

    Conklin, J.L.; Anuras, S.

    1981-01-01

    The syndrome of intestinal pseudo-obstruction is a complex of signs and symptoms of intestinal obstruction without evidence of mechanical obstruction of the intestinal lumen. A patient with radiation-induced intestinal pseudoobstruction is described. The patient is a 74-year old woman with a history of chronic diarrhea, recurrent episodes of crampy abdominal pain, nausea and vomiting since receiving a 13,000 rad radiation dose to the pelvis in 1954. She has been hospitalized on many occasions for symptoms and signs of bowel obstruction. Upper gastrointestinal contrast roentgenograms with small bowel follow-through done during these episodes revealed multiple dilated loops of small bowel with no obstructing lesion. Barium enemas revealed no obstructing lesion. Each episode resolved with conservative therapy. Other secondary causes for intestinal pseudo-obstruction were ruled out in our patient. She gave no history of familial gastrointestinal disorders. Although postirradiation motility abnormalities have been demonstrated experimentally this is the first report of radiation induced intestinal pseudo-obstruction

  4. Degradation Mechanism of Poly(Ether-Urethane) Estane Induced by High Energy Radiation (III) : Radiolytic Gases and Water Soluble Products

    International Nuclear Information System (INIS)

    Dannoux, A.

    2006-01-01

    higher than 5 MGy, the H 2 formation and O 2 consumption decrease, whereas CO 2 and CO radiolytic yields increase, which suggests a shift in the oxidative degradation mechanism. Moreover, other minor radiolytic gases have been identified and their concentrations increase with the dose. The weight loss versus leaching time and dose has been measured. For doses higher than 5 MGy, the weight loss increases drastically and approaches about 25% for 15 leaching days. The extractible fraction is composed of oligomers. These products are mainly issued from the degradation of PTMG soft segments. From these results, a degradation mechanism of poly(ether-urethane) induced by high energy radiation under oxygen is proposed

  5. Radiation-induced caries as the late effect of radiation therapy in the head and neck region

    Directory of Open Access Journals (Sweden)

    Katarzyna Dobroś

    2015-10-01

    Full Text Available Overall improvement in the nationwide system of medical services has consequently boosted the number of successfully treated patients who suffer from head and neck cancer. It is essential to effectively prevent development of radiation-induced caries as the late effect of radiation therapy. Incidence and severity of radiation-induced changes within the teeth individually vary depending on the patient’s age, actual radiation dose, size of radiation exposure field, patient’s general condition and additional risk factors. Inadequately managed treatment of caries may lead to loss of teeth, as well as prove instrumental in tangibly diminishing individual quality of life in patients. Furthermore, the need to have the teeth deemed unyielding or unsuitable for the application of conservative methods of treatment duly extracted is fraught for a patient with an extra hazard of developing osteoradionecrosis (ORN, while also increasing all attendant therapeutic expenditures. The present paper aims to offer some practical insights into currently available methods of preventing likely development of radiation-induced caries.

  6. Electromagnetic radiation properties of foods and agricultural products

    International Nuclear Information System (INIS)

    Mohsenin, N.N.

    1984-01-01

    In this book, the author examines the effects of the various regions of the electromagnetic radiation spectrum on foods and agricultural products. Among the regions of the electromagnetic radiation spectrum covered are high-energy beta and neutron particles, gamma-rays and X-rays, to lower-energy visible, near infrared, infrared, microwave and low-energy radiowaves and electric currents. Dr. Mohsenin applies these electromagnetic phenomena to food products such as fruits, vegetables, seeds, dairy products, meat and processed foods. Contents: Some Basic Concepts of Electromagnetic Radiation. Basic Instruments for Measurement of Optical Properties. Applications of Radiation in the Visible Spectrum. Color and its Measurement. Sorting for Color and Appearance. Near-Infrared and Infrared Radiation Applications. Applications of High-Energy Radiation. Related Concepts of Microwaves, Radiowaves, and Electric Currents. Measurement of Electrical Properties of Foods and Agricultural Products. Applications of Electrical Properties. Appendix, Cited References. Subject Index

  7. Computer simulation of radiation-induced nanostructure formation in amorphous materials

    International Nuclear Information System (INIS)

    Li, K.-D.; Perez-Bergquist, Alejandro; Wang, Lumin

    2009-01-01

    In this study, 3D simulations based on a theoretical model were developed to investigate radiation-induced nanostructure formation in amorphous materials. Model variables include vacancy production and recombination rates, ion sputtering effects, and redeposition of sputtered atoms. In addition, a phase field model was developed to predict vacancy diffusion as a function of free energies of mixing and interfacial energies. The distribution profile of the vacancy production rate along the depth of an irradiated matrix was considered as a near Gaussian approximation according to Monte-Carlo TRIM code calculations. Dynamic processes responsible for nanostructure evolution were simulated by updating the vacancy concentration profile over time. Simulated morphologies include cellular nanoholes, nanowalls, nanovoids, and nanofibers, with the resultant morphology dependant upon the incident ion species and ion fluence. These simulated morphologies are consistent with experimental observations achieved under comparable experimental conditions. Our model provides a distinct numerical approach to accurately predicting morphological results for ion-irradiation-induced nanostructures.

  8. Diseases induced by ionising radiation

    International Nuclear Information System (INIS)

    1984-11-01

    An interim report is presented by the Industrial Injuries Advisory Council in accordance with Section 141 of the Social Security Act 1975 on the question whether the terms of prescription for occupational diseases induced by ionising radiation should be amended to cover a wider range of conditions. A lack of persuasive statistical data has prevented reliable estimates of health risks of radiation workers in the UK to be made. However the report gives details of the progress made so far and the difficulties encountered. (U.K.)

  9. Radiation-induced cancers of the head and neck, (3)

    International Nuclear Information System (INIS)

    Umatani, Katsunori; Satoh, Takeo; Yoshino, Kunitoshi; Takagi, Tadashi; Fujii, Takashi; Hatta, Chihiro; Maetani, Chikahide; Lu, Bo

    1989-01-01

    This paper discusses twenty patients with radiation-induced cancers of the head and neck treated in the Department of Otorhinolaryngology, the Center for Adult Diseases, Osaka, from January 1979 to December 1985. The most common site of radiation-induced cancers was the hypopharynx and cervical esophagus (70%). We found synchronous double cancers in 2 out of the 20 patients (10%). One patient had hypopharyngeal cancer and thyroid cancer, and the other had oropharyngeal cancer and thyroid cancer. All of the laryngeal cancers were in the supraglottic area. Cancer of the hypopharynx and cervical esophagus occurred more frequently in females (1:3.7 males-females ratio). Half of the patients (10/20) had received irradiation for tuberculous cervical adenitis and 8 patients had been irradiated for malignant tumors. The averaged latent period in the patients who had irradiated for benign conditions was 37.4 years, and that for malignant diseases was 16.0 years. Therefore the latent period of the former was 2.3 times as long as that of the latter. The incidence of radiation-induced cancers in all the patients who had the cancer of the hypopharynx and cervical esophagus was 9% and that of the laryngeal cancer was 0.7%. The incidence of radiation-induced cancers in the hypopharynx and cervical esophagus remarkably differed from that in the larynx. However, it was suggested that the larynx was as resistant to radiation induction as the hypopharynx. Six of the 20 patients (30%) had radiation-induced thyroid tumors. Among them, the incidence of cancers was 33%. (author)

  10. Study on production of useful metabolites by development of advanced cell culture techniques using radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Byung Yeoup; Lee, Seung Sik; Bai, Hyounwoo; Singh, Sudhir; Lee, Eun Mi; Hong, Sung Hyun; Park, Chul Hong; Srilatha, B.; Kim, Mi Ja; Lee, Ohchul

    2012-01-15

    The purpose of this project is improvement of investigation, materialization and evaluation techniques on effectiveness for functional natural compounds throughout development of tissue/cell culture techniques for mass production of useful metabolites using radiation. Research scope includes Development of a technique for radiation tissue and cell culture, Database construction for radiation response in plants and radiation effects, Construction of general-purpose national based techniques of cell culture technique using radiation. Main results are as follow: Development of a technique for radiation tissue and cell culture for Erigeron breviscapus (Vant.) Hand. Mazz.; Identification and functional analysis of AtTDX (chaperone and peroxidase activities); Functional analysis of radiation(gamma ray, electron beam, and proton beam) induced chaperon protein activities (AtTDX); Determine the action mechanism of yPrx2; Development of transgenic plant with bas I gene from Arabidopsis; Development of transgenic plant with EoP gene from centipedegrass; Identification of radiation induced multi functional compounds from Aloe; Determination of the effects of radiation on removing undesirable color and physiological activities (Schizandra chinensis baillon, centipedegrass); Determine the action mechanism of transgenic plant with 2-Cys Prx for heat stress resistance; Determination of the effects of centipedegrass extracts on anti-cancer activities; Functional analysis of centipedegrass extracts (anti-virus effects)

  11. γ-radiation induced tetracycline removal in an aqueous solution

    International Nuclear Information System (INIS)

    Zhou Fei; Guo Zhaobing; Zhang Chaozhi; Lin Mingyue; Wu Menglong; Zhao Yongfu

    2012-01-01

    Degradation effect of tetracycline (TC) by γ-radiation was investigated in an aqueous solution. The effects of initial concentrations of TC, pH values, combining with H 2 O 2 or CH 3 OH on degradation of TC were studied. Results showed that TC can be effectively degradated by γ-irradiation in an aqueous solution. Degradation of TC could be remarkably improved both in acid solution and alkaline solution, especially when pH value was 9.0. In addition, H 2 O 2 could gently promote degradation of TC induced by γ-radiation. While, CH 3 OH markedly restrained degradation of TC induced by γ-radiation. The degradation mechanism of TC was supposed by results of quantum chemical calculations and LC-MS. Results proved that degradation of TC induced by γ-radiation was mainly ascribed to · OH oxidation. (authors)

  12. Dose-dependency and reversibility of radiation-induced injury in cardiac explant-derived cells of mice

    Science.gov (United States)

    Luo, Lan; Yan, Chen; Urata, Yoshishige; Hasan, Al Shaimaa; Goto, Shinji; Guo, Chang-Ying; Zhang, Shouhua; Li, Tao-Sheng

    2017-01-01

    We evaluated the dose-dependency and reversibility of radiation-induced injury in cardiac explant-derived cells (CDCs), a mixed cell population grown from heart tissues. Adult C57BL/6 mice were exposed to 0, 10, 50 and 250 mGy γ-rays for 7 days and atrial tissues were collected for experiments 24 hours after last exposure. The number of CDCs was significantly decreased by daily exposure to over 250 mGy. Interestingly, daily exposure to over 50 mGy significantly decreased the c-kit expression and telomerase activity, increased 53BP1 foci in the nuclei of CDCs. However, CD90 expression and growth factors production in CDCs were not significantly changed even after daily exposure to 250 mGy. We further evaluated the reversibility of radiation-induced injury in CDCs at 1 week and 3 weeks after a single exposure to 3 Gy γ-rays. The number and growth factors production of CDCs were soon recovered at 1 week. However, the increased expression of CD90 were retained at 1 week, but recovered at 3 weeks. Moreover, the decreased expression of c-kit, impaired telomerase activity, and increased 53BP1 foci were poorly recovered even at 3 weeks. These data may help us to find the most sensitive and reliable bio-parameter(s) for evaluating radiation-induced injury in CDCs. PMID:28098222

  13. Possible radioprotective effect of folic acid supplementation on low dose ionizing radiation-induced genomic instability in vitro.

    Science.gov (United States)

    Padula, Gisel; Ponzinibbio, María Virginia; Seoane, Analia I

    2016-08-01

    Ionizing radiation (IR) induces DNA damage through production of single and double-strand breaks and reactive oxygen species (ROS). Folic acid (FA) prevents radiation-induced DNA damage by modification of DNA synthesis and/or repair and as a radical scavenger. We hypothesized that in vitro supplementation with FA will decrease the sensitivity of cells to genetic damage induced by low dose of ionizing radiation. Annexin V, comet and micronucleus assays were performed in cultured CHO cells. After 7 days of pre-treatment with 0, 100, 200 or 300 nM FA, cultures were exposed to radiation (100 mSv). Two un-irradiated controls were executed (0 and 100 nM FA). Data were statistically analyzed with X2-test and linear regression analysis (P 0.05). We observed a significantly decreased frequency of apoptotic cells with the increasing FA concentration (P <0.05). The same trend was observed when analyzing DNA damage and chromosomal instability (P <0.05 for 300 nM). Only micronuclei frequencies showed significant differences for linear regression analysis (R2=94.04; P <0.01). Our results have demonstrated the radioprotective effect of folic acid supplementation on low dose ionizing radiation-induced genomic instability in vitro; folate status should be taken into account when studying the effect of low dose radiation in environmental or occupational exposure.

  14. Protective Effect of Anthocyanins from Lingonberry on Radiation-induced Damages

    Directory of Open Access Journals (Sweden)

    Shuang-Qi Tian

    2012-12-01

    Full Text Available There is a growing concern about the serious harm of radioactive materials, which are widely used in energy production, scientific research, medicine, industry and other areas. In recent years, owing to the great side effects of anti-radiation drugs, research on the radiation protectants has gradually expanded from the previous chemicals to the use of natural anti-radiation drugs and functional foods. Some reports have confirmed that anthocyanins are good antioxidants, which can effectively eliminate free radicals, but studies on the immunoregulatory and anti-radiation effects of anthocyanins from lingonberry (ALB are less reported. In this experiment, mice were given orally once daily for 14 consecutive days before exposure to 6 Gy of gamma-radiation and were sacrificed on the 7th day post-irradiation. The results showed that the selected dose of extract did not lead to acute toxicity in mice; while groups given anthocyanins orally were significantly better than radiation control group according to blood analysis; pretreatment of anthocyanins significantly (p < 0.05 enhanced the thymus and spleen indices and spleen cell survival compared to the irradiation control group. Pretreatment with anthocyanins before irradiation significantly reduced the numbers of micronuclei (MN in bone marrow polychromatic erythrocytes (PCEs. These findings indicate that anthocyanins have immunostimulatory potential against immunosuppression induced by the radiation.

  15. Involvement of inducible nitric oxide synthase in radiation-induced vascular endothelial damage

    International Nuclear Information System (INIS)

    Hong, Chang-Won; Lee, Joon-Ho; Kim, Suwan; Noh, Jae Myoung; Kim, Young-Mee; Pyo, Hongryull; Lee, Sunyoung

    2013-01-01

    The use of radiation therapy has been linked to an increased risk of cardiovascular disease. To understand the mechanisms underlying radiation-induced vascular dysfunction, we employed two models. First, we examined the effect of X-ray irradiation on vasodilation in rabbit carotid arteries. Carotid arterial rings were irradiated with 8 or 16 Gy using in vivo and ex vivo methods. We measured the effect of acetylcholine-induced relaxation after phenylephrine-induced contraction on the rings. In irradiated carotid arteries, vasodilation was significantly attenuated by both irradiation methods. The relaxation response was completely blocked by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, a potent inhibitor of soluble guanylate cyclase. Residual relaxation persisted after treatment with L-N ω -nitroarginine (L-NA), a non-specific inhibitor of nitric oxide synthase (NOS), but disappeared following the addition of aminoguanidine (AG), a selective inhibitor of inducible NOS (iNOS). The relaxation response was also affected by tetraethylammonium, an inhibitor of endothelium-derived hyperpolarizing factor activity. In the second model, we investigated the biochemical events of nitrosative stress in human umbilical-vein endothelial cells (HUVECs). We measured iNOS and nitrotyrosine expression in HUVECs exposed to a dose of 4 Gy. The expression of iNOS and nitrotyrosine was greater in irradiated HUVECs than in untreated controls. Pretreatment with AG, L-N 6 -(1-iminoethyl) lysine hydrochloride (a selective inhibitor of iNOS), and L-NA attenuated nitrosative stress. While a selective target of radiation-induced vascular endothelial damage was not definitely determined, these results suggest that NO generated from iNOS could contribute to vasorelaxation. These studies highlight a potential role of iNOS inhibitors in ameliorating radiation-induced vascular endothelial damage. (author)

  16. Increased radiosensitivity and radiation-induced apoptosis in SRC-3 knockout mice

    International Nuclear Information System (INIS)

    Jin Jie; Wang Yu; Xu Yang; Chen Shilei; Wang Junping; Ran Xinze; Su Yongping; Wang Jin

    2014-01-01

    Steroid receptor coactivator-3 (SRC-3), a multifunctional transcriptional coactivator, plays an important role in regulation of cell apoptosis in chemoresistant cancer cells. However, its role in radiation-induced apoptosis in hematopoietic cells is still unclear. In this study, we used SRC-3 knockout (SRC-3 -/- ) mice to assess the role of SRC-3 in radiation-induced hematopoietic injury in vivo. After a range of doses of irradiation, SRC-3 -/- mice exhibited lower counts of peripheral blood cells and bone marrow (BM) mononuclear cells and excessive BM depression, which resulted in a significantly higher mortality compared with wildtype mice. Moreover, BM mononuclear cells obtained from SRC-3 -/- mice showed a remarkable increase in radiation-induced apoptosis. Collectively, our data demonstrate that SRC-3 plays a role in radiation-induced apoptosis of BM hematopoietic cells. Regulation of SRC-3 might influence the radiosensitivity of hematopoietic cells, which highlights a potential therapeutic target for radiation-induced hematopoietic injury. (author)

  17. Radiation induced changes in the airway - anaesthetic implications

    African Journals Online (AJOL)

    Adele

    CASE REPORT. Southern African Journal of Anaesthesia & Analgesia - May 2004. 19. Radiation ... Summary: Radiation induces a variety of changes in the airway that can potentially lead to difficult intubation. ... Mask holding and ventilation is.

  18. Indirect detection of radiation sources through direct detection of radiolysis products

    Science.gov (United States)

    Farmer, Joseph C [Tracy, CA; Fischer, Larry E [Los Gatos, CA; Felter, Thomas E [Livermore, CA

    2010-04-20

    A system for indirectly detecting a radiation source by directly detecting radiolytic products. The radiation source emits radiation and the radiation produces the radiolytic products. A fluid is positioned to receive the radiation from the radiation source. When the fluid is irradiated, radiolytic products are produced. By directly detecting the radiolytic products, the radiation source is detected.

  19. Studies on protective effects of superoxide dismutase on radiation induced-chromosomal aberrations

    International Nuclear Information System (INIS)

    Zheng Siying; Jiang Jiagui; Lin Xingcheng

    1987-09-01

    This study demonstrates that radiation induced-chromosomal aberrations are not only due to the direct effect of radiation h it , but the indirect effect of free radical as well. Therefore, chromosome damage induced by radiation may be reduced by adding exogenous SOD into the radiation exposed lymphocyte culture to eliminate the superoxide free radical which damages DNA. On the other hand, however, the radiosensitivity of lymphocytes can be raised by adding SOD inhibitor (DDC) into the lymphocyte culture, which makes radiation induced-chromosomal damages more severely

  20. Toxic clinical hypoxic radiation sensitizers plus radiation-induced toxicity

    International Nuclear Information System (INIS)

    Richmond, R.C.

    1984-01-01

    The operational definition espoused twelve years ago that clinical hypoxic radiation sensitizers should be nontoxic interferes with the recognition and research of useful radiation sensitizers. Eight years ago the toxic antitumor drug cis-dichlorodiammineplatinum(II) was reported to be a hypoxic radiation sensitizer and the selective antitumor action of this drug was stressed as potentially creating tumor-targeted radiation sensitization. This rationale of oxidative antitumor drugs as toxic and targeted clinical sensitizers is useful, and has led to the study reported here. The antitumor drug cis-(1,1-cyclobutane-dicarboxylato)diammineplatinum(II), or JM-8, is being tested in clinical trials. Cells of S. typhimurium in PBS in the presence of 0.2mM JM-8 are found to be sensitized to irradiation under hypoxic, but not oxic, conditions. JM-8 is nontoxic to bacteria at this concentration, but upon irradiation the JM-8 solution becomes highly toxic. This radiation induced toxicity of JM-8 preferentially develops from hypoxic solution, and thus contributes to the rationale of hypoxic tumor cell destruction

  1. 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

  2. Carcinogenesis induced by low-dose radiation

    Directory of Open Access Journals (Sweden)

    Piotrowski Igor

    2017-11-01

    Full Text Available Although the effects of high dose radiation on human cells and tissues are relatively well defined, there is no consensus regarding the effects of low and very low radiation doses on the organism. Ionizing radiation has been shown to induce gene mutations and chromosome aberrations which are known to be involved in the process of carcinogenesis. The induction of secondary cancers is a challenging long-term side effect in oncologic patients treated with radiation. Medical sources of radiation like intensity modulated radiotherapy used in cancer treatment and computed tomography used in diagnostics, deliver very low doses of radiation to large volumes of healthy tissue, which might contribute to increased cancer rates in long surviving patients and in the general population. Research shows that because of the phenomena characteristic for low dose radiation the risk of cancer induction from exposure of healthy tissues to low dose radiation can be greater than the risk calculated from linear no-threshold model. Epidemiological data collected from radiation workers and atomic bomb survivors confirms that exposure to low dose radiation can contribute to increased cancer risk and also that the risk might correlate with the age at exposure.

  3. Selectivity of radiation-induced processes in hydrocarbons, related polymers and organized polymer systems

    International Nuclear Information System (INIS)

    Feldman, V.I.; Sukhov, F.F.; Zezin, A.A.; Orlov, A.Yu.

    1999-01-01

    Fundamental aspects of the selectivity of radiation-induced events in polymers and polymeric systems were considered: (1) The grounds of selectivity of the primary events were analyzed on the basis of the results of studies of model compounds (molecular aspect). Basic results were obtained for hydrocarbon molecules irradiated in low-temperature matrices. The effects of selective localization of the primary events on the radical formation were examined for several polymers irradiated at low and superlow temperatures (77 and 15 K). A remarkable correlation between the properties of prototype ionized molecules (radical cations) and selectivity of the primary bond rupture in the corresponding polymers were found for polyethylene, polystyrene and some other hydrocarbon polymers. The first direct indication of selective localization of primary events at conformational defects was obtained for oriented high-crystalline polyethylene irradiated at 15 K. The significance of dimeric ring association was proved for the radiation chemistry of polystyrene. Specific mechanisms of low-temperature radiation-induced degradation were also analyzed for polycarbonate and poly(alkylene terephthalates). (2) Specific features of the localization of primary radiation-induced events in microheterogeneous polymeric systems were investigated (microstructural aspect). It was found that the interphase processes played an important role in the radiation chemistry of such systems. The interphase electron migration may result in both positive and negative non-additive effects in the formation of radiolysis products. The effects of component diffusion and chemical reactions on the radiation-induced processes in microheterogeneous polymeric systems were studied with the example of polycarbonate - poly(alkylene terephthalate) blends. (3) The effects of restricted molecular motion on the development of the radiation-chemical processes in polymers were investigated (dynamic aspect). In particular, it

  4. Radiation-induced physical ageing in network arsenic-sulfide/selenide glasses

    International Nuclear Information System (INIS)

    Shpotyuk, M; Golovchak, R; Kozdras, A; Shpotyuk, O

    2010-01-01

    Effect of radiation-induced physical ageing is investigated by differential scanning calorimetry method in As x Se 100-x (10 ≤ x ≤ 42) and As x S 100-x (30 ≤ x ≤ 42) glasses. Obtained results are compared with conventional physical ageing at normal conditions. Significant radiation-induced physical ageing is recorded for glassy As x S 100-x within 30 ≤ x x Se 100-x glasses from the same compositional interval do not show any measurable changes in DSC curves after γ-irradiation. Observed difference in radiation-induced physical ageing in arsenic-sulfide/selenide glasses is explained by a greater lifetime of γ-induced excitations within sulfur-based network in comparison with selenium-based one.

  5. Suppression of radiation-induced in vitro carcinogenesis by ascorbic acid

    International Nuclear Information System (INIS)

    Tauchi, Hiroshi; Sawada, Shozo

    1993-01-01

    The effects of ascorbic acid on radiation-induced in vitro carcinogenesis have been reported using neoplastic transformation system of C3H 10T1/2 cells. In these reports, no suppressive effect on X-ray-induced transformation was observed with 6 weeks' administration of ascorbic acid (daily addition for 5 days per week) by Kennedy (1984), whereas apparent suppression was observed with daily addition for 7 days by Yasukawa et al (1989). We have tested the effects of ascorbic acid on 60 Co gamma-ray or 252 Cf fission neutron-induced transformation in Balb/c 3T3 cells. The transformation induced by both types of radiations was markedly suppressed when ascorbic acid was daily added to the medium during first 8 days of the post-irradiation period. If ascorbic acid was added for a total of 8 days but with a day's interruption in the middle, the suppression of transformation was decreased. These results suggest that continuous presence of ascorbic acid for a certain number of days is needed to suppress radiation-induced transformation. Since ascorbic acid also suppressed the promotion of radiation-induced transformation by TPA when both chemicals were added together into the medium, ascorbic acid might act on the promotion stage of transformation. Therefore, the effect of ascorbic acid on the distribution of protein kinase C activity was also investigated, and possible mechanisms of suppression of radiation-induced transformation by ascorbic acid will be discussed. (author)

  6. Ionizing radiation for sterilization of medical products and biological tissues

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S K; Raghevendrarao, M K [Bhabha Atomic Research Centre, Bombay (India). Library and Technical Information Section

    1975-10-01

    The article reviews the deliberations of the International Symposium on Ionizing Radiation for Sterilization of Medical Products and Biological Tissues which was held during 9-13 December 1974 under the auspices of the IAEA at the Bhabha Atomic Research Centre, Bombay. 42 papers were presented in the following broad subject areas: (1) Microbiological Control aspects of radiation sterilization, (2) Dosimetry aspects of radiation sterilization practices, (3) Effects of sterilizing radiation dose on the constituents of medical products, (4) Application of radiation sterilization of medical products of biological origin, (5) Technological aspects of radiation sterilization facilities, (6) Radiation sterilization of pharmaceutical substances, (7) Reports on current status of radiation sterilization of medical products in IAEA member states and (8) Working group discussion on the revision of the IAEA recommended code of practice for radiation sterilization of medical products.

  7. Radiation-induced segregation and phase stability in ferritic-martensitic alloy T 91

    Energy Technology Data Exchange (ETDEWEB)

    Wharry, Janelle P.; Jiao Zhijie; Shankar, Vani [University of Michigan, 2355 Bonisteel Blvd, Ann Arbor, MI 48109-2104 (United States); Busby, Jeremy T. [Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37831 (United States); Was, Gary S., E-mail: gsw@umich.edu [University of Michigan, 2355 Bonisteel Blvd, Ann Arbor, MI 48109-2104 (United States)

    2011-10-01

    Radiation-induced segregation in ferritic-martensitic alloy T 91 was studied to understand the behavior of solutes as a function of dose and temperature. Irradiations were conducted using 2 MeV protons to doses of 1, 3, 7 and 10 dpa at 400 deg. C. Radiation-induced segregation at prior austenite grain boundaries was measured, and various features of the irradiated microstructure were characterized, including grain boundary carbide coverage, the dislocation microstructure, radiation-induced precipitation and irradiation hardening. Results showed that Cr, Ni and Si segregate to prior austenite grain boundaries at low dose, but segregation ceases and redistribution occurs above 3 dpa. Grain boundary carbide coverage mirrors radiation-induced segregation. Irradiation induces formation of Ni-Si-Mn and Cu-rich precipitates that account for the majority of irradiation hardening. Radiation-induced segregation behavior is likely linked to the evolution of the precipitate and dislocation microstructures.

  8. The effects of cysteamine on the radiation-induced apoptosis

    International Nuclear Information System (INIS)

    Choi, Young Min; Cho, Heung Lae; Park, Chang Gyo; Lee, Hyung Sik; Hur, Won Joo

    2000-01-01

    To investigate the pathways of radiation induced apoptosis and the effect of cysteamine (β-mercaptoethylamine), as a radioprotector, on it. HL-60 cells were assigned to control, irradiated, and cysteamine (1 mM, 10 mM) pretreated groups. Irradiation was given in a single fraction of 10 Gy (6 MV x-ray) and cysteamine was administered 1 hour before irradiation. The activities of caspase-8 were measured in control and irradiated group to evaiuate its relation to the radiation induced apoptosis. To evaluate the role of cysteamine in radiation induced apoptosis, the number of viable cells, the expression and activity or caspase-3, and the expression of poly (ADP-ribose) polymerase (PARP) were measured and compared after irradiating the HL cells with cysteamine pretreatment or not. The intracellular caspase-8 activity, known to be related to the death receptor induced apoptosis, was not affected by irradiation( p>0.05). The number of viable cells began to decrease from 6 hours after irradiation (p>0.05), but the number of viable cells in 1 mM cysteamine pretreated group was not decreased after irradiation and was similar to those in the control group. In caspase-3 analyses, known as apoptosis executioner, its expression was not different but its activity was increased by irradialion(p>0.05). However, this increase of activity was suppressed by the pretreatment of 1 mM cysteamine. The cleavage of PARP, thought to be resulted from caspase-3 activation, occurred, after irradiation, which was attenuated by the pretreatment of 1 mM cysteamine. These results show that radiation induced apoptotic process is somewhat different from death receptor induced one and the pretreatment of 1 mM cysteamine has a tendency to decrease the radiation-induced apoptosis in HL-60 cells

  9. Radiation-induced mutagenicity and lethality in Ames tester strains of Salmonella

    International Nuclear Information System (INIS)

    Isildar, M.; Bakale, G.

    1984-01-01

    Mutation and killing induced by X radiation and 60 Co γ radiation were studied in six different histidine-requiring auxotrophs of Salmonella typhimurium. Strain TA100, which is sensitive to base-pair substitutions, and strains TA2637 and TA98, which are sensitive to frameshifts, carry the pKM101 plasmid and exhibit significantly higher radiation-induced mutations compared to their plasmidless parent strains TA1535, TA1537, and TA1538, respectively. Among the plasmid-containing strains, TA98 and TA2637 are much more sensitive to the mutagenic action of radiation than is TA100 based on a comparison with their respective spontaneous mutation rates; however, no uniformity was observed in the responses of the strains to the lethal action of ionizing radiation. The following conclusions are consistent with these observations: (1) the standard Ames Salmonella assay correctly identifies ionizing radiation as a mutagenic agent; (2) frameshift-sensitive parent strains are more sensitive to the mutagenic effects of ionizing radiation than is the only strain studied that is sensitive to base-pair substitutions; and (3) enhancement of mutagenesis and survival is related to plasmid-mediated repair of DNA damage induced by ionizing radiation and does not involve damage induced by Cerenkov-generated uv radiation which is negligible for our irradiation conditions

  10. Radiation-induced cerebrovascular disease in children

    International Nuclear Information System (INIS)

    Wright, T.L.; Bresnan, M.J.

    1976-01-01

    Radiation-induced internal carotid artery occlusion has not been well recognized previously as a cause of childhood cerebrovascular disease. A child who had received radiation as a neonate for a hemangioma involving the left orbit at the age of 6 years experienced a recurrent right-sided paresis, vascular headaches, and speech difficulties. Angiography showed a hypoplastic left carotid artery with occlusion of both the anterior and middle cerebral arteries. Collateral vessels bypassed the occluded-stenotic segments. Review of the literature showed two additional cases of large vessel occlusion in childhood associated with anastomatic telangiectatic vessel development following early radiation therapy of facial hemangioma

  11. Effects of hydroxylated benzaldehyde derivatives on radiation-induced reactions involving various organic radicals

    Science.gov (United States)

    Ksendzova, G. A.; Samovich, S. N.; Sorokin, V. L.; Shadyro, O. I.

    2018-05-01

    In the present paper, the effects of hydroxylated benzaldehyde derivatives and gossypol - the known natural occurring compound - on formation of decomposition products resulting from radiolysis of ethanol and hexane in deaerated and oxygenated solutions were studied. The obtained data enabled the authors to make conclusions about the effects produced by the structure of the compounds under study on their reactivity towards oxygen- and carbon-centered radicals. It has been found that 2,3-dihydroxybenzaldehyde, 4,6-di-tert-butyl-2,3-dihydroxybenzaldehyde and 4,6-di-tert-butyl-3-(1,3-dioxane-2-yl)-1,2-dihydroxybenzene are not inferior in efficiency to butylated hydroxytoluene - the industrial antioxidant - as regards suppression of the radiation-induced oxidation processes occurring in hexane. The derivatives of hydroxylated benzaldehydes were shown to have a significant influence on radiation-induced reactions involving α-hydroxyalkyl radicals.

  12. Radiation-induced nitric oxide mitigates tumor hypoxia and radioresistance in a murine SCCVII tumor model

    International Nuclear Information System (INIS)

    Nagane, Masaki; Yasui, Hironobu; Yamamori, Tohru; Zhao, Songji; Kuge, Yuji; Tamaki, Nagara; Kameya, Hiromi; Nakamura, Hideo; Fujii, Hirotada; Inanami, Osamu

    2013-01-01

    Highlights: •IR-induced NO increased tissue perfusion and pO 2 . •IR increased NO production in tumors without changes in the mRNA and protein levels of NOS isoforms. •NOS activity assay showed that IR upregulated eNOS activity in tumors. •IR-induced NO decreased tumor hypoxia and altered tumor radiosensitivity. -- Abstract: Tumor hypoxia, which occurs mainly as a result of inadequate tissue perfusion in solid tumors, is a well-known challenge for successful radiotherapy. Recent evidence suggests that ionizing radiation (IR) upregulates nitric oxide (NO) production and that IR-induced NO has the potential to increase intratumoral circulation. However, the kinetics of NO production and the responsible isoforms for NO synthase in tumors exposed to IR remain unclear. In this study, we aimed to elucidate the mechanism by which IR stimulates NO production in tumors and the effect of IR-induced NO on tumor radiosensitivity. Hoechst33342 perfusion assay and electron spin resonance oxymetry showed that IR increased tissue perfusion and pO 2 in tumor tissue. Immunohistochemical analysis using two different hypoxic probes showed that IR decreased hypoxic regions in tumors; treatment with a nitric oxide synthase (NOS) inhibitor, L-NAME, abrogated the effects of IR. Moreover, IR increased endothelial NOS (eNOS) activity without affecting its mRNA or protein expression levels in SCCVII-transplanted tumors. Tumor growth delay assay showed that L-NAME decreased the anti-tumor effect of fractionated radiation (10 Gy × 2). These results suggested that IR increased eNOS activity and subsequent tissue perfusion in tumors. Increases in intratumoral circulation simultaneously decreased tumor hypoxia. As a result, IR-induced NO increased tumor radiosensitivity. Our study provides a new insight into the NO-dependent mechanism for efficient fractionated radiotherapy

  13. Carcinomatous versus radiation-induced brachial plexus neuropathy in breast cancer

    International Nuclear Information System (INIS)

    Bagley, F.H.; Walsh, J.W.; Cady, B.; Salzman, F.A.; Oberfield, R.A.; Pazianos, A.G.

    1978-01-01

    A retrospective study was performed of 18 women in whom ipsilateral brachial plexus neuropathy developed after treatment for carcinoma of the breast. In the absence of metastatic tumor elsewhere, the only distinguishing feature between carcinomatous neuropathy and radiation-induced neuropathy was the symptom-free interval after mastectomy and radiation therapy. Women with an interval of less than a year have radiation-induced neuropathy. Brachial plexus exploration in difficult diagnostic situations will permit early treatment and avoid debilitating loss of function. Brachial plexus exploration for biopsy is safe and free of complications if performed carefully. Treatment of carcinomatous neuropathy is most likely to succeed if the tumor is hormonally sensitive, but radiotherapy may also be effective. Treatment of radiation-induced neuropathy remains largely ineffective

  14. Study on Production of Useful Metabolites by Development of Advanced Cell Culture Techniques Using Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Byung Yeoup; Kim, J. H.; Lee, S. S.; Shyamkumar, B.; An, B. C.; Moon, Y. R.; Lee, E. M.; Lee, M. H.

    2009-02-15

    The purpose of this project is improvement of investigation, materialization and evaluation techniques on effectiveness for functional natural compounds throughout development of tissue/cell culture techniques for mass production of useful metabolites using radiation. Research scope includes 1) Development of a technique for radiation tissue and cell culture, 2) Database construction for radiation response in plants and radiation effects, 3) Construction of general-purpose national based techniques of cell culture technique using radiation. Main results are as follow: Establishment of a tissue culture system (Rubus sp., Lithospermum erythrorhizon, and Rhodiola rosea); characterization of radiation activated gene expression from cultivated bokbunja (Rubus sp.) and Synechocystis sp., identification of gamma-ray induced color change in plants; identification of sensitivity to gamma-ray from Omija (Schisandra chinensis) extract; identification of the response of thylakoid proteins to gamma-ray in spinach and Arabidopsis; identification of gamma-ray induced gene relating to pigment metabolism; characterization of different NPQ changes to gamma-irradiated plants; verification of the effects of rare earth element including anti-bacterial and anti-fungal properties and as a growth enhancer; identification of changes in the growth of gamma-irradiated Synechocystis; and investigation of liquid cell culture conditions from Rhodiola rosea

  15. Study on Production of Useful Metabolites by Development of Advanced Cell Culture Techniques Using Radiation

    International Nuclear Information System (INIS)

    Chung, Byung Yeoup; Kim, J. H.; Lee, S. S.; Shyamkumar, B.; An, B. C.; Moon, Y. R.; Lee, E. M.; Lee, M. H.

    2009-02-01

    The purpose of this project is improvement of investigation, materialization and evaluation techniques on effectiveness for functional natural compounds throughout development of tissue/cell culture techniques for mass production of useful metabolites using radiation. Research scope includes 1) Development of a technique for radiation tissue and cell culture, 2) Database construction for radiation response in plants and radiation effects, 3) Construction of general-purpose national based techniques of cell culture technique using radiation. Main results are as follow: Establishment of a tissue culture system (Rubus sp., Lithospermum erythrorhizon, and Rhodiola rosea); characterization of radiation activated gene expression from cultivated bokbunja (Rubus sp.) and Synechocystis sp., identification of gamma-ray induced color change in plants; identification of sensitivity to gamma-ray from Omija (Schisandra chinensis) extract; identification of the response of thylakoid proteins to gamma-ray in spinach and Arabidopsis; identification of gamma-ray induced gene relating to pigment metabolism; characterization of different NPQ changes to gamma-irradiated plants; verification of the effects of rare earth element including anti-bacterial and anti-fungal properties and as a growth enhancer; identification of changes in the growth of gamma-irradiated Synechocystis; and investigation of liquid cell culture conditions from Rhodiola rosea

  16. Clinical effectiveness of Ancer 20 injection for prevention of radiation-induced oral mucositis

    International Nuclear Information System (INIS)

    Suzuki, Tsubura; Shimoyama, Tetsuo; Nasu, Daisuke; Kaneko, Takahiro; Horie, Norio

    2000-01-01

    Although radiotherapy is very useful for treatment of oral cancer, it can cause radiation-induced oral mucositis as a troublesome side effect. Ancer 20 injection is useful for enhancing macrophage function, and apart from its inductive effect on IL-3, it also enhances G-CSF production. Therefore, Ancer 20 injection might also prevent mucositis. This effect was tested by administering the drug to prevent oral mucositis during radiotherapy. Eleven patients (5 males and 6 females, aged 39 to 84 yr, mean 64.5 yr) with squamous cell carcinoma were examined. Radiation was applied externally with a linear accelerator up to a total dose of 20-70 Gy, mean 38.2 Gy. All patients received a small dose of cisplatin concomitantly. Ancer 20 injection 1 ml twice weekly was administered subcutaneously. There was almost no objective or subjective abnormality up to a dose of 30 Gy, and at doses higher than that, the symptoms were mild in comparison with general mucosal reactions. This showed that Ancer 20 injection is useful for prevention of radiation-induced oral mucositis during radiotherapy of oral cancer. (author)

  17. Radiation-induced apoptosis in different pH environments in vitro

    International Nuclear Information System (INIS)

    Lee, Hyung-Sik; Park, Heon J.; Lyons, John C.; Griffin, Robert J.; Auger, Elizabeth A.; Song, Chang W.

    1997-01-01

    Purpose: The effect of environmental pH on the radiation-induced apoptosis in tumor cells in vitro was investigated. Methods and Materials: Mammary adenocarcinoma cells of A/J mice (SCK cells) were irradiated with γ-rays using a 137 Cs irradiator and incubated in media of different pHs. After incubation at 37 deg. C for 24-120 h the extent of apoptosis was determined using agarose gel electrophoresis, TdT-mediated dUTP-biotin nick end labeling (TUNEL) staining, flow cytometry, and release of 3 H from 3 H-thymidine labeled cells. The clonogenicity of the cells irradiated in different pH medium was determined, and the progression of cells through the cell cycle after irradiation in different pHs was also determined with flow cytometry. Results: Irradiation with 2-12 Gy of γ-rays induced apoptosis in SCK cells in pH 7.5 medium within 48 h as judged from the results of four different assays mentioned. Radiation-induced apoptosis declined as the medium pH was lowered from 7.5 to 6.4. Specifically, the radiation-induced degradation of DNA including the early DNA breaks, as determined with the TUNEL method, progressively declined as the medium pH was lowered so that little DNA fragmentation occurred 48 h after irradiation with 12 Gy in pH 6.6 medium. When the cells were irradiated and incubated for 48 h in pH 6.6 medium and the medium was replaced with pH 7.5 medium, DNA fragmentation promptly occurred. DNA fragmentation also occurred even in pH 6.6 medium when the cells were irradiated and maintained in pH 7.5 medium for 8 h or longer post-irradiation before incubation in pH 6.6 medium. The radiation-induced G 2 arrest in pH 6.6 medium lasted markedly longer than that in pH 7.5 medium. Conclusion: Radiation-induced apoptosis in SCK cells in vitro is reversibly suppressed in an acidic environment. Taking the results of four different assays together, it was concluded that early step(s) in the apoptotic pathway, probably the DNA break or upstream of DNA break, is

  18. A review on radiation-induced nucleation and growth of colloidal metallic nanoparticles

    OpenAIRE

    Abedini, Alam; Daud, Abdul Razak; Abdul Hamid, Muhammad Azmi; Kamil Othman, Norinsan; Saion, Elias

    2013-01-01

    This review presents an introduction to the synthesis of metallic nanoparticles by radiation-induced method, especially gamma irradiation. This method offers some benefits over the conventional methods because it provides fully reduced and highly pure nanoparticles free from by-products or chemical reducing agents, and is capable of controlling the particle size and structure. The nucleation and growth mechanism of metallic nanoparticles are also discussed. The competition between nucleation ...

  19. Use of radiation-induced polymers as temporary or permanent diverting agent

    International Nuclear Information System (INIS)

    Knight, B.L.; Rhudy, J.S.; Gogarty, W.B.

    1975-01-01

    Temporary or permanent permeability reduction or plugging of porous medium to the flow of fluids is effected by treating, preferably by injecting under pressure into the pores, the porous medium with an aqueous solution containing a water-soluble polymer obtained as a product of radiation-induced polymerization of acrylamide and/or methacrylamide and acrylic acid, methacrylic acid, and/or alkali metal salts thereof. The polymer has sufficient properties to effect substantial permeability reduction of the porous medium. The polymerization is preferably carried out in 10 to 60 percent aqueous monomer solution with gamma radiation. A mixture of monomers, before radiation preferably contain 25 to 99 percent acrylamide and 75 to 1 percent sodium acrylate. Permeability can be restored by subsequently treating the porous medium with a chemical to break down the polymer, e.g., hydrazine hypochlorite solution, strong mineral acids, or bases. (U.S.)

  20. Low-dose radiation-induced endothelial cell retraction

    International Nuclear Information System (INIS)

    Kantak, S.S.; Onoda, J.M.; Diglio, C.A.; Harper Hospital, Detroit, MI

    1993-01-01

    The data presented here are representative of a series of studies designed to characterize low-dose radiation effects on pulmonary microvascular endothelium. Data suggest that post-irradiation lung injuries (e.g. oedema) may be induced with only a single fraction of therapeutic radiation, and thus microscopic oedema may initiate prior to the lethal effects of radiation on the microvascular endothelium, and much earlier than would be suggested by the time course for clinically-detectable oedema. (author)

  1. The Role of Warfarin Alone or in Combination with Certain Natural Products Against Blood Disorders Induced by Gamma Radiation in Experimental Animals

    International Nuclear Information System (INIS)

    Fahim, M.G.; Radwan, R.R.; Shaaban, E.A.; El-Denshary, E.S.

    2016-01-01

    The effect of warfarin against blood disorder induced by radiation and possible effect of certain natural products in modifying anticoagulant effect of warfarin in irradiated rats was investigated. Prothrombin time (PT), international normalized ratio (INR), partial thromboplastin time (PTT), thrombin time (TT), fibrinogen level and platelet count were evaluated. Furthermore, plasma level of malondialdehyde (MDA), reduced glutathione (GSH) and nitric oxide (NO) were determined. The obtained data showed that irradiation elevated Pt, INR, PTT, TT and fibrinogen level. Moreover, irradiation increased MDA and NO levels while, reduced GSH level. It was found that administration of garlic, fenugreek or green tea with warfarin for one week before irradiation resulted in elevation in PT and INR. Results suggest that patients on warfarin and exposed to radiation are specifically advised to avoid taking herbal medicines or to have their PT and INR measured within two weeks of starting the drug, to be on a safer side

  2. Pathophysiology of Radiation-Induced Dysphagia in Head and Neck Cancer.

    Science.gov (United States)

    King, Suzanne N; Dunlap, Neal E; Tennant, Paul A; Pitts, Teresa

    2016-06-01

    Oncologic treatments, such as curative radiotherapy and chemoradiation, for head and neck cancer can cause long-term swallowing impairments (dysphagia) that negatively impact quality of life. Radiation-induced dysphagia comprised a broad spectrum of structural, mechanical, and neurologic deficits. An understanding of the biomolecular effects of radiation on the time course of wound healing and underlying morphological tissue responses that precede radiation damage will improve options available for dysphagia treatment. The goal of this review is to discuss the pathophysiology of radiation-induced injury and elucidate areas that need further exploration.

  3. RhoA GTPase regulates radiation-induced alterations in endothelial cell adhesion and migration

    International Nuclear Information System (INIS)

    Rousseau, Matthieu; Gaugler, Marie-Hélène; Rodallec, Audrey; Bonnaud, Stéphanie; Paris, François; Corre, Isabelle

    2011-01-01

    Highlights: ► We explore the role of RhoA in endothelial cell response to ionizing radiation. ► RhoA is rapidly activated by single high-dose of radiation. ► Radiation leads to RhoA/ROCK-dependent actin cytoskeleton remodeling. ► Radiation-induced apoptosis does not require the RhoA/ROCK pathway. ► Radiation-induced alteration of endothelial adhesion and migration requires RhoA/ROCK. -- Abstract: Endothelial cells of the microvasculature are major target of ionizing radiation, responsible of the radiation-induced vascular early dysfunctions. Molecular signaling pathways involved in endothelial responses to ionizing radiation, despite being increasingly investigated, still need precise characterization. Small GTPase RhoA and its effector ROCK are crucial signaling molecules involved in many endothelial cellular functions. Recent studies identified implication of RhoA/ROCK in radiation-induced increase in endothelial permeability but other endothelial functions altered by radiation might also require RhoA proteins. Human microvascular endothelial cells HMEC-1, either treated with Y-27632 (inhibitor of ROCK) or invalidated for RhoA by RNA interference were exposed to 15 Gy. We showed a rapid radiation-induced activation of RhoA, leading to a deep reorganisation of actin cytoskeleton with rapid formation of stress fibers. Endothelial early apoptosis induced by ionizing radiation was not affected by Y-27632 pre-treatment or RhoA depletion. Endothelial adhesion to fibronectin and formation of focal adhesions increased in response to radiation in a RhoA/ROCK-dependent manner. Consistent with its pro-adhesive role, ionizing radiation also decreased endothelial cells migration and RhoA was required for this inhibition. These results highlight the role of RhoA GTPase in ionizing radiation-induced deregulation of essential endothelial functions linked to actin cytoskeleton.

  4. Radiation-induced osteosarcoma of the calvaria; Case report

    Energy Technology Data Exchange (ETDEWEB)

    Sugita, Yasuo; Shigemori, Minoru; Miyagi, Jun; Ochiai, Satoshi; Lee, Souichi; Watanabe, Toshinori; Abe, Hitoshi; Morimatsu, Minoru [Kurume Univ., Fukuoka (Japan). School of Medicine

    1992-01-01

    The authors report a case of radiation-induced calvarial osteosarcoma. A 58-year-old female received subtotal removal of the pituitary adenoma and 5000 rads postoperative irradiation. Seven years later, an osteoblastic osteosarcoma occurred in the frontotemporal region. She received total tumor removal and chemotherapy. However, computed tomography subsequently revealed multiple small lesions at the margin of the bone flap. A chest x-ray film demonstrated lung metastasis. Local recurrence and lung metastasis require careful attention in radiation-induced osteosarcoma patients. (author).

  5. Effect of dose on radiation-induced conductivity in polymers

    International Nuclear Information System (INIS)

    Tyutnev, A.P.; Saenko, V.S.; Pozhidaev, E.D.; Ikhsanov, R.Sh.

    2007-01-01

    Numerical simulation of radiation-induced conductivity in polymers upon long-term irradiation on the basis of the generalized Rose-Fowler-Vaisberg model, which allows for both dipolar carrier transport and generation of radiation traps during irradiation, was performed. The unusual properties of radiation-induced conductivity, such as the appearance of a maximum on current transients, the absence of a steady state, and a substantial difference between these curves for the first and subsequent irradiation, are rationalized in terms of the formation of free radicals, the major feature of radiolysis in the chemical aspect. This interpretation does not require the involvement of degradation or crosslinking processes, unlike other interpretations that appear in the literature. With the use of low-density polyethylene as an example, it was shown that radiation-induced conductivity both upon pulse and continuous irradiation can satisfactorily be described with the unified set of parameters of the generalized Rose-Fowler-Vaisberg model [ru

  6. Radiation-induced gene amplification in rodent and human cells

    International Nuclear Information System (INIS)

    Luecke-Huhle, C.; Gloss, B.; Herrlich, P.

    1990-01-01

    Ionizing and UV radiations induce amplification of SV40 DNA sequences integrated in the genome of Chinese hamster cells and increase amplification of the dihydrofolate reductase (DHFR) gene during methotrexate selection in human skin fibroblasts of a patient with ataxia telangiectasia. Various types of external (60-Co-γ-rays, 241-Am-α-particles, UV) or internal radiation (caused by the decay of 125 I incorporated into DNA in form of I-UdR) were applied. By cell fusion experiments it could be shown that SV40 gene amplification is mediated by one or several diffusible trans-acting factors induced or activated in a dose dependent manner by all types of radiation. One of these factors binds to a 10 bp sequence within the minimal origin of replication of SV40. In vivo competition with an excess of a synthetic oligonucleotide comprising this sequence blocks radiation-induced amplification. (author) 25 refs.; 8 figs

  7. Radiation-induced spindle cell sarcoma: A rare case report

    Directory of Open Access Journals (Sweden)

    Khan Mubeen

    2009-01-01

    Full Text Available Ionizing radiation has been known to induce malignant transformation in human beings. Radiation-induced sarcomas are a late sequel of radiation therapy. Most sarcomas have been reported to occur after exposure to a radiation dose of 55 Gray (Gy and above, with a dose ranging from 16 to 112 Gys. Spindle cell sarcomas, arising after radiotherapy given to treat the carcinoma of head and neck region is a very uncommon sequel. This is a rare case report of spindle cell sarcoma of left maxilla, in a 24-year-old male, occurring as a late complication of radiotherapy with Cobalt-60 given for the treatment of retinoblastoma of the left eye 21 years back.

  8. Radiation induced microbial pesticide

    International Nuclear Information System (INIS)

    Kim, Ki Yup; Lee, Young Keun; Kim, Jae Sung; Kim, Jin Kyu; Lee, Sang Jae

    2000-01-01

    To control plant pathogenic fungi, 4 strains of bacteria (K1, K3, K4, YS1) were isolated from mushroom compost and hot spring. K4, K1, K3, YS1 strain showed wide antifungal spectrum and high antifungal activities against 13 kinds of fungi. Mutants of K1 and YS1 strains were induced by gamma-ray radiation and showed promising antifungal activities. These wild type and mutants showed resistant against more than 27 kinds of commercial pesticides among 30 kinds of commercial pesticides test particularly, YS1-1006 mutant strain showed resistant against hydrogen oxide. And mutants had increased antifungal activity against Botryoshaeria dothidea. These results suggested that radiation could be an useful method for the induction of functional mutants. (author)

  9. Radiation-induced chondrosarcoma of the maxilla 7-year after combined chemoradiation for tonsillar lymphoma.

    Science.gov (United States)

    Mohammadianpanah, M; Gramizadeh, B; Omidvari, Sh; Mosalaei, A

    2004-01-01

    Radiation-induced sarcoma is a rare complication of radiation therapy. We report a case of radiation-induced chondrosarcoma of the maxilla. An 80-year-old Persian woman developed radiation-induced chondrosarcoma of the left maxilla 7 years after combined chemotherapy and external beam radiation therapy for the Ann Arbor stage IE malignant lymphoma of the right tonsil. She underwent suboptimal tumour resection and died due to extensive locoregional disease 8 months later. An English language literature search of Medline using the terms chondrosarcoma, radiation-induced sarcoma and maxilla revealed only one earlier reported case. We describe the clinical and pathological features of this case and review the literature on radiation-induced sarcomas.

  10. Radiation-induced chondrosarcoma of the maxilla 7-year after combined chemoradiation for tonsillar lymphoma

    Directory of Open Access Journals (Sweden)

    Mohammadianpanah M

    2004-07-01

    Full Text Available Radiation-induced sarcoma is a rare complication of radiation therapy. We report a case of radiation-induced chondrosarcoma of the maxilla. An 80-year-old Persian woman developed radiation-induced chondrosarcoma of the left maxilla 7 years after combined chemotherapy and external beam radiation therapy for the Ann Arbor stage IE malignant lymphoma of the right tonsil. She underwent suboptimal tumour resection and died due to extensive locoregional disease 8 months later. An English language literature search of Medline using the terms chondrosarcoma, radiation-induced sarcoma and maxilla revealed only one earlier reported case. We describe the clinical and pathological features of this case and review the literature on radiation-induced sarcomas.

  11. Radiation-induced physical ageing in network arsenic-sulfide/selenide glasses

    Energy Technology Data Exchange (ETDEWEB)

    Shpotyuk, M; Golovchak, R; Kozdras, A; Shpotyuk, O, E-mail: shpotyuk@novas.lviv.ua

    2010-11-15

    Effect of radiation-induced physical ageing is investigated by differential scanning calorimetry method in As{sub x}Se{sub 100-x} (10 {<=} x {<=} 42) and As{sub x}S{sub 100-x} (30 {<=} x {<=} 42) glasses. Obtained results are compared with conventional physical ageing at normal conditions. Significant radiation-induced physical ageing is recorded for glassy As{sub x}S{sub 100-x} within 30 {<=} x < 40 range, while As{sub x}Se{sub 100-x} glasses from the same compositional interval do not show any measurable changes in DSC curves after {gamma}-irradiation. Observed difference in radiation-induced physical ageing in arsenic-sulfide/selenide glasses is explained by a greater lifetime of {gamma}-induced excitations within sulfur-based network in comparison with selenium-based one.

  12. Functional properties of nisin–carbohydrate conjugates formed by radiation induced Maillard reaction

    International Nuclear Information System (INIS)

    Muppalla, Shobita R.; Sonavale, Rahul; Chawla, Surinder P.; Sharma, Arun

    2012-01-01

    Nisin–carbohydrate conjugates were prepared by irradiating nisin either with glucose or dextran. Increase in browning and formation of intermediate products was observed with a concomitant decrease in free amino and reducing sugar groups indicating occurrence of the Maillard reaction catalyzed by irradiation. Nisin–carbohydrate conjugates showed a broad spectrum antibacterial activity against Gram negative bacteria (Escherichia coli, Pseudomonas fluorescence) as well as Gram positive bacteria (Staphylococcus aureus, Bacillus cereus). Results of antioxidant assays, including that of DPPH radical-scavenging activity and reducing power, showed that the nisin–dextran conjugates possessed better antioxidant potential than nisin–glucose conjugate. These results suggested that it was possible to enhance the functional properties of nisin by preparing radiation induced conjugates suitable for application in food industry. - Highlights: ► Nisin–carbohydrate conjugates were prepared using radiation induced Maillard reaction. ► Conjugation of nisin with dextran/glucose resulted in improvement of antibacterial spectrum. ► Conjugates of nisin with dextran/glucose had significant radical scavenging activity.

  13. Detection of the Level of Reactive Oxygen Species Induced by Ionizing Radiation in Cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Kyu; Chung, Dong Min; Kim, Jin-Hong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    By definition, the direct effect is referred to interaction between photon and DNA molecule, whereas the indirect effect is mediated by the reactive oxygen species (ROS) generated by radiolysis and subsequent reaction. It has been reported that ROS produced after exposure to IR can react with cellular materials such as DNA, proteins, carbohydrates and lipids. ROS is free radicals such as the superoxide anion, hydroxyl radicals and the non-radical hydrogen peroxide. Cells generate ROS during aerobic metabolism. Excessive production of ROS can lead to oxidative stress, genetic alteration and even cell death. It has been reported that ROS plays a critical role in radiation-induced cell injury. Thus, it is of great interest to determine the radiation-induced ROS level. Many kinds of methods to detect the level of ROS have been developed so far. There were random changes of fluorescence intensity in the treatment after irradiation. This result meant that this protocol was not appropriate for determination of radiation-induced ROS. On the other hand, the fluorescence intensity was increased in a dose-dependent manner when the cells were treated with the DCFH-DA solution before irradiation. Conclusions can be drawn from the experimental results of this study. In order to properly measure the ROS level in the cells exposed to ionizing radiation, the cells should be treated with the DCFH-DA solution before irradiation.

  14. Inhibition of radiation-induced polyuria by histamine receptor antagonists

    Energy Technology Data Exchange (ETDEWEB)

    Donlon, M.A.; Melia, J.A.; Helgeson, E.A.; Wolfe, W.W.

    1986-03-01

    In previous studies the authors have demonstrated that gamma radiation results in polyuria, which is preceded by polydypsia. This suggests that the increased thirst elicited by radiation causes increased urinary volume (UV). Histamine, which is released following radiation exposure, also elicits drinking by nonirradiated rats when administered exogenously. In this study the authors have investigated both the role of water deprivation and the effect of histamine receptor antagonists (HRA) on radiation-induced polyuria. Sprague-Dawley rats were housed individually in metabolic cages. Water was allowed ad libitum except in deprivation experiments where water was removed for 24 hr immediately following radiation. Cimetidine (CIM), an H2 HRA, and dexbromopheniramine (DXB), an H1 HRA, were administered i.p. (16 and 1 mg/kg, respectively) 30 min prior to irradiation (950 rads from a cobalt source). UV was determined at 24-hr intervals for 3 days preceding irradiation and 24 hr postirradiation. UV in DXB treated rats was significantly reduced 24 hr postirradiation (CON = 427 +/- 54%; DXB = 247 +/- 39% of preirradiated CON) compared to postirradiation control values. CIM did not affect postirradiation UV. These data suggest that radiation-induced polyuria is caused by polydypsia which is, in part, mediated by histamine induced by an H1 receptor.

  15. Inhibition of radiation-induced polyuria by histamine receptor antagonists

    International Nuclear Information System (INIS)

    Donlon, M.A.; Melia, J.A.; Helgeson, E.A.; Wolfe, W.W.

    1986-01-01

    In previous studies the authors have demonstrated that gamma radiation results in polyuria, which is preceded by polydypsia. This suggests that the increased thirst elicited by radiation causes increased urinary volume (UV). Histamine, which is released following radiation exposure, also elicits drinking by nonirradiated rats when administered exogenously. In this study the authors have investigated both the role of water deprivation and the effect of histamine receptor antagonists (HRA) on radiation-induced polyuria. Sprague-Dawley rats were housed individually in metabolic cages. Water was allowed ad libitum except in deprivation experiments where water was removed for 24 hr immediately following radiation. Cimetidine (CIM), an H2 HRA, and dexbromopheniramine (DXB), an H1 HRA, were administered i.p. (16 and 1 mg/kg, respectively) 30 min prior to irradiation (950 rads from a cobalt source). UV was determined at 24-hr intervals for 3 days preceding irradiation and 24 hr postirradiation. UV in DXB treated rats was significantly reduced 24 hr postirradiation (CON = 427 +/- 54%; DXB = 247 +/- 39% of preirradiated CON) compared to postirradiation control values. CIM did not affect postirradiation UV. These data suggest that radiation-induced polyuria is caused by polydypsia which is, in part, mediated by histamine induced by an H1 receptor

  16. Current study on ionizing radiation-induced mitochondial DNA damage and mutations

    International Nuclear Information System (INIS)

    Zhou Xin; Wang Zhenhua; Zhang Hong

    2012-01-01

    Current advance in ionizing radiation-induced mitochondrial DNA damage and mutations is reviewed, in addition with the essential differences between mtDNA and nDNA damage and mutations. To extent the knowledge about radiation induced mitochondrial alterations, the researchers in Institute of Modern Physics, Chinese Academy of Sciences developed some technics such as real-time PCR, long-PCR for accurate quantification of radiation induced damage and mutations, and in-depth investigation about the functional changes of mitochondria based on mtDNA damage and mutations were also carried out. In conclusion, the important role of mitochondrial study in radiation biology is underlined, and further study on mitochondrial study associated with late effect and metabolism changes in radiation biology is pointed out. (authors)

  17. Pathophysiological Responses in Rat and Mouse Models of Radiation-Induced Brain Injury.

    Science.gov (United States)

    Yang, Lianhong; Yang, Jianhua; Li, Guoqian; Li, Yi; Wu, Rong; Cheng, Jinping; Tang, Yamei

    2017-03-01

    The brain is the major dose-limiting organ in patients undergoing radiotherapy for assorted conditions. Radiation-induced brain injury is common and mainly occurs in patients receiving radiotherapy for malignant head and neck tumors, arteriovenous malformations, or lung cancer-derived brain metastases. Nevertheless, the underlying mechanisms of radiation-induced brain injury are largely unknown. Although many treatment strategies are employed for affected individuals, the effects remain suboptimal. Accordingly, animal models are extremely important for elucidating pathogenic radiation-associated mechanisms and for developing more efficacious therapies. So far, models employing various animal species with different radiation dosages and fractions have been introduced to investigate the prevention, mechanisms, early detection, and management of radiation-induced brain injury. However, these models all have limitations, and none are widely accepted. This review summarizes the animal models currently set forth for studies of radiation-induced brain injury, especially rat and mouse, as well as radiation dosages, dose fractionation, and secondary pathophysiological responses.

  18. Cell kinetic studies on radiation induced leukemogenesis

    International Nuclear Information System (INIS)

    Nakao, Isamu; Suzuki, Gen; Imai, Yasufumi; Kawase, Yoshiko; Nose, Masako; Hirashima, Kunitake; Bessho, Masami

    1989-01-01

    The purpose of this study was threefold: (1) to determine the clonal origin of radiation-induced thymic lymphoma in mice with cellular mosaicism for phosphoglycerate kinase; (2) to determine the incidence and latent period of myeloid leukemia and thymic lymphoma induced by whole-body exposure to median doses (3.0 Gy or less) in RFM/MsNrs-2 mice; and (3) to examine the influence of human recombinant interleukin-2 (hrIL-2). Thymic lymphoma was of a single cell origin. The incidence of radiation-induced myeloid leukemia and thymic lymphoma in RFM mice increased in a dose dependent fashion. Mean latent periods of both myeloid leukemia and thymic lymphoma after irradiation became shorter in proportion to radiation doses. When hrIL-2 was injected to RFM mice receiving 3.0 Gy, mean survivals were shorter in thymoma-bearing mice than the control mice. This suggested that hrIL-2 shortens the promotion step of thymoma. Administration of hrIL-2 failed to alter the incidence of myeloid leukemia or the mean survival of mice having myeloid leukemia, indicating that the protocol of hrIL-2 administration was not so sufficient as to alter the myeloid leukemogenesis. (Namekawa, K)

  19. Image Guidance and Assessment of Radiation Induced Gene Therapy

    National Research Council Canada - National Science Library

    Pelizzari, Charles

    2004-01-01

    Image guidance and assessment techniques are being developed for combined radiation/gene therapy, which utilizes a radiation-inducible gene promoter to cause expression of tumor necrosis factor alpha...

  20. Immobilization of yeast cells on hydrogel carriers obtained by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Luzhao Xin; Carenza, M.; Kaetsu, Isao; Kumakura, Minoru; Yoshida, Masaru; Fujimura, Takashi

    1992-01-01

    Polymer hydrogels were obtained by radiation-induced copolymerization at -78 o C of aqueous solutions of acrylic and methacrylic esters. The matrices were characterized by equilibrium water content measurements, by optical microscopy observations and by scanning electron microscopy analysis. Yeast cells were immobilized on these hydrogels and the ethanol productivity by batch fermentation was determined. Matrix hydrophilicity and porosity were found to deeply influence the adhesion of yeast cells and, hence, the ethanol productivity. The latter as well as other physico-chemical properties were also affected by the presence of a crosslinking agent added in small amounts to the polymerizating mixture. (author)

  1. 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)

  2. Radiation-induced decomposition of anion exchange resins

    International Nuclear Information System (INIS)

    Baidak, Aliaksandr; LaVerne, Jay A.

    2010-01-01

    Radiation-induced degradation of the strongly basic anion exchange resin Amberlite TM IRA400 in NO 3 - , Cl - and OH - forms has been studied. The research focused on the formation of molecular hydrogen in the gamma-radiolysis of water slurries of these quaternary ammonium resins with varying water content. Extended studies with various electron scavengers (NO 3 - , N 2 O and O 2 ) prove an important role of e solv - in the formation of H 2 from these resins. An excess production of H 2 in these systems at about 85% water weight fraction was found to be due to trimethylamine, dimethylamine and other compounds that leach from the resin to the aqueous phase. Irradiations with 5 MeV 4 He ions were performed to simulate the effects of α-particles.

  3. 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

  4. Study on DNA damages induced by UV radiation

    International Nuclear Information System (INIS)

    Doan Hong Van; Dinh Ba Tuan; Tran Tuan Anh; Nguyen Thuy Ngan; Ta Bich Thuan; Vo Thi Thuong Lan; Tran Minh Quynh; Nguyen Thi Thom

    2015-01-01

    DNA damages in Escherichia coli (E. coli) exposed to UV radiation have been investigated. After 30 min of exposure to UV radiation of 5 mJ/cm"2, the growth of E. coli in LB broth medium was about only 10% in compared with non-irradiated one. This results suggested that the UV radiation caused the damages for E. coli genome resulted in reduction in its growth and survival, and those lesions can be somewhat recovered. For both solutions of plasmid DNAs and E. coli cells containing plasmid DNA, this dose also caused the breakage on single and double strands of DNA, shifted the morphology of DNA plasmid from supercoiled to circular and linear forms. The formation of pyrimidine dimers upon UV radiation significantly reduced when the DNA was irradiated in the presence of Ganoderma lucidum extract. Thus, studies on UV-induced DNA damage at molecular level are very essential to determine the UV radiation doses corresponding to the DNA damages, especially for creation and selection of useful radiation-induced mutants, as well as elucidation the protective effects of the specific compounds against UV light. (author)

  5. Radiation-induced Pulmonary Damage in Lung Cancer Patients

    International Nuclear Information System (INIS)

    Chung, Su Mi; Choi, Ihl Bohng; Kang, Mi Mun; Kim, In Ah; Shinn, Kyung Sub

    1993-01-01

    Purpose: A retrospective analysis was performed to evaluate the incidence of radiation induced lung damage after the radiation therapy for the patients with carcinoma of the lung. Method and Materials: Sixty-six patients with lung cancer (squamous cell carcinoma 27, adenocarcinoma 14, large cell carcinoma 2, small cell carcinoma 13, unknown 10) were treated with definitive, postoperative or palliative radiation therapy with or without chemotherapy between July 1987 and December 1991. There were 50 males and 16 females with median age of 63 years(range: 33-80 years). Total lung doses ranged from 500 to 6,660 cGy (median 3960 cGy) given in 2 to 38 fractions (median 20) over a range of 2 to 150 days (median 40 days) using 6 MV or 15 MV linear accelerator. To represent different fractionation schedules of equivalent biological effect, the estimated single dose(ED) model, ED=D·N-0.377·T-0.058 was used in which D was the lung dose in cGy, N was the number of fractions, and T was the overall treatment time in days. The range of ED was 370 to 1357. The endpoint was a visible increase in lung density within the irradiated volume on chest X-ray as observed independently by three diagnostic radiologists. Patients were grouped according to ED, treatment duration, treatment modality and age, and the percent incidence of pulmonary damage for each group was determined. Result: In 40 of 66 patients, radiation induced change was seen on chest radiographs between 11 days and 314 days after initiation of radiation therapy. The incidence of radiation pneumonitis was increased according to increased ED, which was statistically significant (p=0.001). Roentgenographic charges consistent with radiation pneumonitis were seen in 100% of patients receiving radiotherapy after lobectomy or pneumonectomy, which was not statistically significant. In 32 patients who also received chemotherapy, there was no difference in the incidence of radiation induced charge between the group with radiation

  6. Squalene Modulates Radiation-Induced Structural, Ultrastructural And Biochemical Changes In Cardiac Muscles Of Male Albino Rats

    International Nuclear Information System (INIS)

    REZK, R.G.; YACOUB, S.F.; ABDEL AZIZ, N.

    2009-01-01

    The failing heart represents an enormous clinical problem and is a major cause of death throughout the world. Hyperlipidemia and oxidative stress have been shown to contribute to heart failure. Squalene is a remarkable bioactive substance that belongs to a class of antioxidants called isoprenoids, which neutralize the harmful effect of excessive free radicals production in the body.The present study was designed to determine the possible protective effect of squalene against oxidative cardiac muscle damage induced by gamma irradiation.Rats were treated daily by gavage with 0.4 ml/kg squalene for 42 days before whole body gamma irradiation at a dose of 4 Gy and continued until animals were sacrificed 3 days post irradiation.Histological examination of cardiac muscles sections by using light and electron microscopes showed that exposure of rats to ionizing radiation has provoked a severe architecture damage such as necrotic nuclei, nuclei located at the periphery, alteration in chromatin distribution, ruptured cell and mitochondrial membranes, cristae of mitochondria disappeared, sticking mitochondria and ruptured myofibers. Structural and ultra-structural changes were associated with severe oxidative stress. Significant increase of lipid peroxidation products (malondialdehyde) (MDA) along with reduction in the activity of the antioxidant enzymes; superoxide dismutase (SOD) and catalse (CAT), and glutathione content (GSH), were recorded.Treatment of rats with squalene has significantly attenuated the radiation-induced oxidative damage and histopathological changes in cardiac muscle which was substantiated by a significant amelioration in the activity of plasma lactate dehydrogenase (LDH), creatine phosphokinase (CPK) and aspartate transaminase (AST). Furthermore, administration of squalene to rats has adjusted the radiation-induced increase in plasma triglycerides (TG), total cholesterol (TC) and low density lipoprotein-cholesterol (LDL-C). Based on these results, it

  7. Characterization of radiation-induced emesis in the ferret

    International Nuclear Information System (INIS)

    King, G.L.

    1988-01-01

    Forty-eight ferrets (Mustela putorius furo) were individually head-shielded and radiated with bilateral 60 Co gamma radiation at 100 cGy min-1 at doses ranging between 49 and 601 cGy. The emetic threshold was observed at 69 cGy, the ED50 was calculated at 77 cGy, and 100% incidence of emesis occurred at 201 cGy. With increasing doses of radiation, the latency to first emesis after radiation decreased dramatically, whereas the duration of the prodromal period increased. Two other sets of experiments suggest that dopaminergic mechanisms play a minor role in radiation-induced emesis in the ferret. Twenty-two animals were injected either intravenously or subcutaneously with 30 to 300 micrograms/kg of apomorphine. Fewer than 50% of the animals vomited to 300 micrograms/kg apomorphine; central dopaminergic receptor activation was apparent at all doses. Another eight animals received 1 mg/kg domperidone prior to either 201 (n = 4) or 401 (n = 4) cGy radiation and their emetic responses were compared with NaCl-injected-irradiated controls (n = 8). At 201 cGy, domperidone significantly reduced only the total time in emetic behavior. At 401 cGy, domperidone had no salutary effect on radiation-induced emesis. The emetic responses of the ferret to radiation and apomorphine are compared with these responses in other vomiting species

  8. Radiation-induced pemphigus vulgaris of the breast; Pemphigus vulgaire radio-induit du sein

    Energy Technology Data Exchange (ETDEWEB)

    Vigna-Taglianti, R.; Russi, E.G. [Department of radiotherapy, Santa Croce e Carle general hospital, Via M. Coppino, 12100 Cuneo (Italy); Denaro, N. [Oncology department, university of Messina, Via consolare Valeria no 1, 98100 Messina (Italy); Numico, G. [Department of medical oncology, U. Parini hospital, 11100 Aosta (Italy); Brizio, R. [Department of histopathology, Santa Croce e Carle general hospital, Via M. Coppino, 12100 Cuneo (Italy)

    2011-07-15

    Pemphigus vulgaris is a rare autoimmune muco-cutaneous bullous disease. Patients with a history of pemphigus vulgaris - who need radiotherapy - may show a long lasting bullous cutaneous manifestation, typical of pemphigus, within radiation fields. The literature describes fewer than 20 radio-induced cases. While systematic corticosteroid therapy has proven to be useful, topical treatment used in association with corticosteroid therapy is rarely described. To our knowledge the use of modern dressing products has never been described. We report our experience in a case in which modern dressing products were usefully associated to systemic therapy. (authors)

  9. Radiation induced estane polymer crosslinking

    International Nuclear Information System (INIS)

    Fletcher, M.; Foster, P.

    1997-01-01

    The exposure of polymeric materials to radiation has been known to induce the effects of crosslinking and degradation. The crosslinking phenomena comes about when two long chain polymers become linked together by a primary bond that extends the chain and increases the viscosity, molecular weight and the elastic modules of the polymer. This process has been observed in relatively short periods of time with fairly high doses of radiation, on the order of several megarads/hour. This paper address low dose exposure over long periods of time to determine what the radiation effects are on the polymeric binder material in PBX 9501. An experimental sample of binder material without explosives will be placed into a thermal and radiation field produced from a W-48 put mod 0. Another sample will be placed in a thermal environment without the radiation. The following is the test plan that was submitted to the Pantex process. The data presented here will be from the first few weeks of exposure and this test will be continued over the next few years. Subsequent data will hopefully be presented in the next compatibility and aging conference

  10. Products of radiation removal of lead from aqueous solutions

    International Nuclear Information System (INIS)

    Drtinova, Barbora; Pospisil, Milan

    2008-01-01

    Full text: Some metal ions, including Pb 2+ can be gradually reduced by primary reducing products of water radiolysis (solvated electrons e aq - and H radicals) to insoluble, easily separable metals. Conditions of water remediation using irradiation with accelerated electrons were studied. The solutions with initial concentration 100 mg/L of Pb(II) (originally nitrate) containing OH radical scavengers were irradiated under intensive agitation in sealed thin-glass ampoules by accelerated electrons (4.5 MeV) from a linear accelerator. Doses ranging from 0.5 to 60 kGy (dose rate of 0.5 kGy/s) determined by an alanine dosimeter were applied. Subsequent process of centrifugation (5000 revs per minute) was used for the separation of product- finely dispersed particles. The changes in metal concentration were determined with error ± 3% by means of atomic absorption spectroscopy with flame atomization. The solid products formed after the irradiation were analyzed by both thermogravimetry and differential thermal analysis. For the pre-irradiated systems were carried out calculations by using PHREEQC in order to determinate the speciation. Without addition of an OH radical scavenger the radiation-induced removal of lead did not occur. The influence of potassium formate HCOOK (1x10 -3 - 4x10 -2 mol/L) and 10% isopropanol as typical OH radical scavengers was individually studied. The lead can be completely removed from aqueous solutions (pH about 5-6) containing 1x10 - :2 mol/L of HCOOK already at the dose of 2.5 kGy. With increasing concentration of HCOOK (1x10 -3 - 4x10 -2 mol/L) increases the amount of Pb(HCOO) + form in the solution before irradiation. The radiation product is metallic lead at low concentration of HCOOK to PbCO 3 at higher concentration of the OH radical scavenger. In the system with isopropanol dominates the form Pb 2+ and the product of radiation reduction is then metallic lead

  11. [Induced thymus aging: radiation model and application perspective for low intensive laser radiation].

    Science.gov (United States)

    Sevost'ianova, N N; Trofimov, A V; Lin'kova, N S; Poliakova, V O; Kvetnoĭ, I M

    2010-01-01

    The influence of gamma-radiation on morphofunctional state of thymus is rather like as natural thymus aging. However gamma-radiation model of thymus aging widely used to investigate geroprotectors has many shortcomings and limitations. Gamma-radiation can induce irreversible changes in thymus very often. These changes are more intensive in comparison with changes, which can be observed at natural thymus aging. Low intensive laser radiation can not destroy structure of thymus and its effects are rather like as natural thymus aging in comparison with gamma-radiation effects. There are many parameters of low intensive laser radiation, which can be changed to improve morphofunctional thymus characteristics in aging model. Using low intensive laser radiation in thymus aging model can be very perspective for investigations of aging immune system.

  12. The involvement of calcium and MAP kinase signaling pathways in the production of radiation-induced bystander effects.

    LENUS (Irish Health Repository)

    Lyng, F M

    2006-04-01

    Much evidence now exists regarding radiation-induced bystander effects, but the mechanisms involved in the transduction of the signal are still unclear. The mitogen-activated protein kinase (MAPK) pathways have been linked to growth factor-mediated regulation of cellular events such as proliferation, senescence, differentiation and apoptosis. Activation of multiple MAPK pathways such as the ERK, JNK and p38 pathways have been shown to occur after exposure of cells to radiation and a variety of other toxic stresses. Previous studies have shown oxidative stress and calcium signaling to be important in radiation-induced bystander effects. The aim of the present study was to investigate MAPK signaling pathways in bystander cells exposed to irradiated cell conditioned medium (ICCM) and the role of oxidative metabolism and calcium signaling in the induction of bystander responses. Human keratinocytes (HPV-G cell line) were irradiated (0.005-5 Gy) using a cobalt-60 teletherapy unit. The medium was harvested 1 h postirradiation and transferred to recipient HPV-G cells. Phosphorylated forms of p38, JNK and ERK were studied by immunofluorescence 30 min-24 h after exposure to ICCM. Inhibitors of the ERK pathway (PD98059 and U0126), the JNK pathway (SP600125), and the p38 pathway (SB203580) were used to investigate whether bystander-induced cell death could be blocked. Cells were also incubated with ICCM in the presence of superoxide dismutase, catalase, EGTA, verapamil, nifedipine and thapsigargin to investigate whether bystander effects could be inhibited because of the known effects on calcium homeostasis. Activated forms of JNK and ERK proteins were observed after exposure to ICCM. Inhibition of the ERK pathway appeared to increase bystander-induced apoptosis, while inhibition of the JNK pathway appeared to decrease apoptosis. In addition, reactive oxygen species, such as superoxide and hydrogen peroxide, and calcium signaling were found to be important modulators of

  13. Radioprotective effect of Rapana thomasiana hemocyanin in gamma induced acute radiation syndrome

    International Nuclear Information System (INIS)

    Kindekov, Ivan; Vassilieva, Vladimir; Aljakova, Mitko; Mileva, Milka; Krastev, Dimo; Raynova, Yuliana; Idakieva, Krassimira; Doumanov, Lyuba

    2014-01-01

    The radioprotective effect of Rapana thomasiana hemocyanin (RtH) against radiation-induced injuries (stomach ulcers, survival time and endogenous haemopoiesis) and post-radiation recovery was investigated in male albino mice (C3H strain). Radiation course was in a dose of 7.5 Gy (LD 100/30 - dose that kills 100% of the mice at 30 days) from "1"3"7Cs with a dose of 2.05 Gy/ min. Radiation injuries were manifested by inducing 2 hematopoietic form of acute radiation syndrome. RtH was administered intraperitoneally in a single dose of 50, 100, 150 and 200 mg/kg body weight (b. w.) once a day for five consecutive days before irradiation. The results obtained showed that radiation exposure led to (1) 100% mortality rate, (2) ulceration in the stomach mucosa and (3) decrease formation of spleen colonies as a marker of endogenous haemopoiesis. Administration of RtH at a dose of 200 mg/kg provided better protection against radiation-induced stomach ulceration, mitigated the lethal effects of radiation exposure and recovered endogenous haemopoiesis versus irradiated but not supplemented mice. It could be expected that RtH will find a use in mitigating radiation induced injury and enhanced radiorecovery. Keywords: Rapana thomasiana hemocyanin; acute radiation syndrome; radioprotective effect; spleen colony assay; stomach ulcerations

  14. Radiation-induced chondrosarcomas: A case report with review of literature

    Directory of Open Access Journals (Sweden)

    Gupta G

    2010-01-01

    Full Text Available Radiation therapy has become an important component of various cancer treatments. The development of second malignancy as a result of radiation therapy is a well-known sinister complication. However, radiation-induced sarcomas (RIS are rare complications of radiation therapy. The timescale between completion of the radiotherapy and the development of a second malignancy, known as the latent period, can vary widely from as little as 5 years to 50 years later. Radiation-induced sarcomas per se are very rare and those with histomorphology of chondrosarcomas are even rarer. We report a rare case of RIS of left iliac bone in a 62-year-old lady after combined chemotherapy and external beam radiation therapy for cervical carcinoma (stage IIb. This case is being reported for its extreme rarity, vivid histology and clinical presentation.

  15. Gene alterations in radiation-induced F344 rat lung tumors

    International Nuclear Information System (INIS)

    Kelly, G.; Hahn, F.F.

    1994-01-01

    The p53 tumor suppressor gene is frequently altered in all major histopathologic types of human lung tumors. Reported p53 mutations include base substitutions, allelic loss, rearrangements, and deletions. Point mutations resulting in base substitutions are clustered within a highly conserved region of the gene encoding exons 508, and mutations in this region substantially extend the half-life of the p53 protein. In addition to its prominent importance in lung carcinogenesis, the p53 gene plays a critical role in the cellular response to genetic damage caused by radiation. Specifically, the protein product of p53 induces a pause or block at the G 1 to S boundary of the cell cycle following radiation-caused DNA damage. This G 1 block may allow the cell time to repair the damaged DNA prior to replication. Cells lacking a functional p53 protein fail to pause for repair and consequently accumulate mutations in the genome at an accelerated rate. p53 has also been implicated as a controlling factor in apoptosis or in programmed cell death induced by DNA-damaging agents, such as ionizing radiation. The p53 gene is mutated in approximately 50% of squamous cell carcinomas from uranium miners who inhaled high doses of radon daughters. The purpose of the present study was to determine if a similar percentage of squamous cell carcinomas with p53 mutations developed in the lungs of rats exposed to aerosols of 239 PuO 2

  16. Radiation technology of improved quality materials production

    International Nuclear Information System (INIS)

    Zajkin, Yu.A.; Nadirov, N.K.; Zajkina, R.F.

    1997-01-01

    The technology of materials production from metals and alloys with high operational properties is developed. The technology is based on use of radiation methods in powder metallurgy. Use of radiation processing allows to improve technological conditions of sintering. It is established, that in certain regimes the sintering temperature is decreasing from 1200 deg C up to 950 deg C in the result of radiation processing of stainless steel powders . According to the processing regimes it is possible load reduction by powder pressing on 15-20 % and sintering time in to 1,5 - 2 times . The radiation methods give possibility to produce high qualitative goods from cheap powder materials without use energy-intensive processes and prolonged processing of finished products

  17. Radioactivity in consumer products : radiation safety and regulatory appraisal

    International Nuclear Information System (INIS)

    Murthy, B.K.S.; Venkataraman, G.; Subrahmanym, P.

    1993-01-01

    Use of radioactive materials in consumer products is in vogue almost since the discovery of radioactivity. There has been a rapid growth in the use of radioactive material in various consumer products such as Ionization Chamber Smoke Detectors (ICSD), Static eliminators, etc. In addition, there are certain manufacturing processes wherein the Naturally Occurring Radioactive Material (NORM) get incorporated in the consumer products. Certain phosphatic fertilizers, titanium dioxide pigments, phospho gypsum plaster boards are some examples in this category. The manufacture and use of these products result in radiation dose to the public apart from radiation exposure to the personnel involved in the manufacturing process. Appropriate radiation control measures have to be taken in the design, manufacture and use of consumer products to ensure that the radiation doses to the public and the population at large do not exceed the relevant limits. While appropriate regulatory controls and surveillance are established for manufacture and use of certain products, these are still to be recognised and established in respect of certain other processes and products. The current status of radiation safety and regulatory control and the lack of these in respect of some products are discussed in this paper. (author). 5 refs

  18. Production and installation of equipments for radiation-induced graft polymerization in liquid phase and dipping techniques

    International Nuclear Information System (INIS)

    Seko, Noriaki; Kasai, Noboru; Tamada, Masao; Hasegawa, Shin; Katakai, Akio; Sugo, Takanobu

    2005-01-01

    Fibrous adsorbent which is synthesized by radiation induced graft polymerization on the trunk polymers such as polymer nonwoven fabrics and woven cloths exhibits an excellent selective adsorption against heavy metal ions and toxic gases at extremely low concentrations. Two equipments were installed to synthesize the metal-ion and gas adsorbents by means of the radiation-induced graft polymerization in the liquid phase and the dipping, respectively. In the reation chamber of the liquid phase reactor, the oxygen decreased to 100 ppm. The inside temperature was elevated at 80C. These characteristics satisfied the specification. The fabric transport can regulate the rate in the range from 1 to 10 m/min. The reactor for the dip grafting could reduce the inside oxygen to 100ppm and inside temperature could reach to 80C, also. The transport system is stable during the dip grafting reaction. The grafting of glycidyl methacrylate was carried out as a characteristic test. The degree of grafting was controlled in the range of 40-70%. The both equipments can graft the trunk polymer, 2000mm in maximum width and 1m in maximum diameter. This size is enough for confirmation practical scale synthesis. (author)

  19. Ionizing radiation induces mitochondrial reactive oxygen species production accompanied by upregulation of mitochondrial electron transport chain function and mitochondrial content under control of the cell cycle checkpoint.

    Science.gov (United States)

    Yamamori, Tohru; Yasui, Hironobu; Yamazumi, Masayuki; Wada, Yusuke; Nakamura, Yoshinari; Nakamura, Hideo; Inanami, Osamu

    2012-07-15

    Whereas ionizing radiation (Ir) instantaneously causes the formation of water radiolysis products that contain some reactive oxygen species (ROS), ROS are also suggested to be released from biological sources in irradiated cells. It is now becoming clear that these ROS generated secondarily after Ir have a variety of biological roles. Although mitochondria are assumed to be responsible for this Ir-induced ROS production, it remains to be elucidated how Ir triggers it. Therefore, we conducted this study to decipher the mechanism of Ir-induced mitochondrial ROS production. In human lung carcinoma A549 cells, Ir (10 Gy of X-rays) induced a time-dependent increase in the mitochondrial ROS level. Ir also increased mitochondrial membrane potential, mitochondrial respiration, and mitochondrial ATP production, suggesting upregulation of the mitochondrial electron transport chain (ETC) function after Ir. Although we found that Ir slightly enhanced mitochondrial ETC complex II activity, the complex II inhibitor 3-nitropropionic acid failed to reduce Ir-induced mitochondrial ROS production. Meanwhile, we observed that the mitochondrial mass and mitochondrial DNA level were upregulated after Ir, indicating that Ir increased the mitochondrial content of the cell. Because irradiated cells are known to undergo cell cycle arrest under control of the checkpoint mechanisms, we examined the relationships between cell cycle and mitochondrial content and cellular oxidative stress level. We found that the cells in the G2/M phase had a higher mitochondrial content and cellular oxidative stress level than cells in the G1 or S phase, regardless of whether the cells were irradiated. We also found that Ir-induced accumulation of the cells in the G2/M phase led to an increase in cells with a high mitochondrial content and cellular oxidative stress level. This suggested that Ir upregulated mitochondrial ETC function and mitochondrial content, resulting in mitochondrial ROS production, and that

  20. Radiation-Induced Esophagitis is Mitigated by Soy Isoflavones

    Directory of Open Access Journals (Sweden)

    Matthew D Fountain

    2016-11-01

    Full Text Available Introduction: Lung cancer patients receiving radiotherapy present with acute esophagitis and chronic fibrosis, as a result of radiation injury to esophageal tissues. We have shown that soy isoflavones alleviate pneumonitis and fibrosis caused by radiation toxicity to normal lung. The effect of soy isoflavones on esophagitis histopathological changes induced by radiation was investigated. Methods: C57BL/6 mice were treated with 10 Gy or 25 Gy single thoracic irradiation and soy isoflavones for up to 16 weeks. Damage to esophageal tissues was assessed by H&E, Masson’s Trichrome and Ki-67 staining at 1, 4, 10, 16 weeks after radiation. The effects on smooth muscle cells and leukocyte infiltration were determined by immunohistochemistry using anti-αSMA and anti-CD45 respectively. Results: Radiation caused thickening of esophageal tissue layers that was significantly reduced by soy isoflavones. Major radiation alterations included hypertrophy of basal cells in mucosal epithelium and damage to smooth muscle cells in muscularis mucosae as well as disruption of collagen fibers in lamina propria connective tissue with leukocyte infiltration. These effects were observed as early as one week after radiation and were more pronounced with a higher dose of 25 Gy. Soy isoflavones limited the extent of tissue damage induced by radiation both at 10 and 25 Gy.Conclusions: Soy isoflavones have a radioprotective effect on the esophagus, mitigating the early and late effects of radiation injury in several esophagus tissue layers. Soy could be administered with radiotherapy to decrease the incidence and severity of esophagitis in lung cancer patients receiving thoracic radiation therapy.

  1. Tissue culture regeneration and radiation induced mutagenesis in banana

    International Nuclear Information System (INIS)

    Kulkarni, V.M.; Ganapathi, T.R.

    2009-01-01

    Radiation induced mutagenesis is an important tool for banana genetic improvement. At BARC, protocols for shoo-tip multiplication of commercial banana varieties have been developed and transferred to user agencies for commercial production. Excellent embryogenic cell suspensions were established in banana cvs. Rasthali and Rajeli, and were maintained at low temperatures for long-term storage. Normal plantlets were successfully regenerated from these cell suspensions. The cell suspensions and shoot-tip cultures were gamma-irradiated for mutagenesis. The mutagenized populations were field screened and a few interesting mutants have been isolated. The existence of genetic variation was confirmed using DNA markers. Further evaluation of these mutants is in progress. (author)

  2. 'Like new': plastic wastes regeneration by radiation induced grafting

    International Nuclear Information System (INIS)

    Laizier, J.; Gaussens, G.; Lemaire, F.

    1978-01-01

    The reclaiming and the recycling of plastic wastes is made especially difficult when those wastes are a mixture of various plastics; this is due to the incompatibility of the polymers. The radiation induced grafting allows to overcome this incompatibility. Results are given which shows that, for various mixtures of reclaimed polyethylene, PVC and polystyrene, an improvement of the properties of the processed blends is obtained by grafting the mixtures of wastes by a suitable polymer; the obtained properties of those regenerated plastic blends are enough attractive from the technical point of view to open a market to those products with a reasonable economical value [fr

  3. Dose rate effectiveness in radiation-induced teratogenesis in mice

    International Nuclear Information System (INIS)

    Kato, F.; Ootsuyama, A.; Norimura, T.

    2000-01-01

    To investigate the role of p53 gene in tissue repair of teratogenic injury, we compared incidence of radiation-induced malformations in homozygous p53(-/-) mice, heterozygous p53(+/-) mice and wild-type p53(+/+) mice. After X-irradiation with 2 Gy at high dose rate on 9.5 days of gestation, p53(-/-) mice showed higher incidences of anomalies and higher resistance to prenatal deaths than p53(+/+) mice. This reciprocal relationship of radiosensitivity to anomalies and deaths supports the notion that embryos or fetuses have a p53-dependent 'guardian' that aborts cells bearing radiation-induced teratogenic DNA damage. In fact, after X-irradiation, the number of apoptotic cells was greatly increased in p53(+/+) fetuses but not in p53(-/-) fetuses. The same dose of γ-ray exposure at low dose rate on 9.5-10.5 day of gestation produced significant reduction of radiation-induced malformation in p53(+/+) and p53(+/-) mice, remained teratogenic for p53(-/-) mice. These results suggest that complete elimination of teratogenic damage from irradiated tissues requires the concerted cooperation of two mechanisms; proficient DNA repair and the p53-dependent apoptotic tissue repair. When concerted DNA repair and apoptosis functions efficiently, there is a threshold dose-rate for radiation-induced malformations. (author)

  4. Radiation-induced premature menopause: a misconception

    International Nuclear Information System (INIS)

    Madsen, Berit L.; Giudice, Linda; Donaldson, Sarah S.

    1995-01-01

    Purpose: To disprove the common view that women who have undergone irradiation to fields excluding the pelvis are at risk for radiation-induced premature menopause, we reviewed menstrual function and fertility among women treated with subtotal lymphoid irradiation for Hodgkin's Disease. Methods and Materials: Treatment and follow-up records of all women less than age 50 at the time of diagnosis of Stage I or II supradiaphragmatic Hodgkin's Disease, treated with subtotal lymphoid irradiation alone and enrolled in radiotherapy trials from 1967 to 1985, were reviewed. In addition, patients were surveyed regarding their menstrual status and fertility history. Results: Thirty-six women, aged 10 to 40 years, with normal menstrual function at the time of Hodgkin's diagnosis, were identified. Mean follow-up was 14 years, with a range of 1.25-22.75 years. The average radiation dose to mantle and paraaortic fields was 40-44 Gy; the calculated scatter radiation dose to the pelvis at the ovaries was 3.2 Gy. There were 38 pregnancies in 18 women; all offspring are normal. One of 36 women (2.7%) experienced premature menopause. The reported rate of premature menopause in women who have not undergone irradiation is 1-3%; not significantly different than the rate in our study. There is a syndrome whereby antibodies to several endocrine organs occur (including the ovary), which is associated with premature ovarian failure. This syndrome may be associated with prior radiation to the thyroid, such as that given by mantle-irradiation for Hodgkin's Disease. We report such a case. Conclusion: There is little risk of premature menopause in women treated with radiation fields that exclude the pelvis. Women with presumed radiation-induced premature menopause warrant an evaluation to exclude other causes of ovarian failure, such as autoimmune disorders

  5. Radiation-Induced Leukemia at Doses Relevant to Radiation Therapy: Modeling Mechanisms and Estimating Risks

    Science.gov (United States)

    Shuryak, Igor; Sachs, Rainer K.; Hlatky, Lynn; Mark P. Little; Hahnfeldt, Philip; Brenner, David J.

    2006-01-01

    Because many cancer patients are diagnosed earlier and live longer than in the past, second cancers induced by radiation therapy have become a clinically significant issue. An earlier biologically based model that was designed to estimate risks of high-dose radiation induced solid cancers included initiation of stem cells to a premalignant state, inactivation of stem cells at high radiation doses, and proliferation of stem cells during cellular repopulation after inactivation. This earlier model predicted the risks of solid tumors induced by radiation therapy but overestimated the corresponding leukemia risks. Methods: To extend the model to radiation-induced leukemias, we analyzed in addition to cellular initiation, inactivation, and proliferation a repopulation mechanism specific to the hematopoietic system: long-range migration through the blood stream of hematopoietic stem cells (HSCs) from distant locations. Parameters for the model were derived from HSC biologic data in the literature and from leukemia risks among atomic bomb survivors v^ ho were subjected to much lower radiation doses. Results: Proliferating HSCs that migrate from sites distant from the high-dose region include few preleukemic HSCs, thus decreasing the high-dose leukemia risk. The extended model for leukemia provides risk estimates that are consistent with epidemiologic data for leukemia risk associated with radiation therapy over a wide dose range. For example, when applied to an earlier case-control study of 110000 women undergoing radiotherapy for uterine cancer, the model predicted an excess relative risk (ERR) of 1.9 for leukemia among women who received a large inhomogeneous fractionated external beam dose to the bone marrow (mean = 14.9 Gy), consistent with the measured ERR (2.0, 95% confidence interval [CI] = 0.2 to 6.4; from 3.6 cases expected and 11 cases observed). As a corresponding example for brachytherapy, the predicted ERR of 0.80 among women who received an inhomogeneous low

  6. Effect of epicatechin against radiation-induced oral mucositis: in vitro and in vivo study.

    Directory of Open Access Journals (Sweden)

    Yoo Seob Shin

    Full Text Available PURPOSE: Radiation-induced oral mucositis limits the delivery of high-dose radiation to head and neck cancer. This study investigated the effectiveness of epicatechin (EC, a component of green tea extracts, on radiation-induced oral mucositis in vitro and in vivo. EXPERIMENTAL DESIGN: The effect of EC on radiation-induced cytotoxicity was analyzed in the human keratinocyte line HaCaT. Radiation-induced apoptosis, change in mitochondrial membrane potential (MMP, reactive oxygen species (ROS generation and changes in the signaling pathway were investigated. In vivo therapeutic effects of EC for oral mucositis were explored in a rat model. Rats were monitored by daily inspections of the oral cavity, amount of oral intake, weight change and survival rate. For histopathologic evaluation, hematoxylin-eosin staining and TUNEL staining were performed. RESULTS: EC significantly inhibited radiation-induced apoptosis, change of MMP, and intracellular ROS generation in HaCaT cells. EC treatment markedly attenuated the expression of p-JNK, p-38, and cleaved caspase-3 after irradiation in the HaCaT cells. Rats with radiation-induced oral mucositis showed decreased oral intake, weight and survival rate, but oral administration of EC significantly restored all three parameters. Histopathologic changes were significantly decreased in the EC-treated irradiated rats. TUNEL staining of rat oral mucosa revealed that EC treatment significantly decreased radiation-induced apoptotic cells. CONCLUSIONS: This study suggests that EC significantly inhibited radiation-induced apoptosis in keratinocytes and rat oral mucosa and may be a safe and effective candidate treatment for the prevention of radiation-induced mucositis.

  7. The influence of infrared radiation on short-term ultraviolet-radiation-induced injuries

    International Nuclear Information System (INIS)

    Kaidbey, K.H.; Witkowski, T.A.; Kligman, A.M.

    1982-01-01

    Because heat has been reported to influence adversely short- and long-term ultraviolet (UV)-radiation-induced skin damage in animals, we investigated the short-term effects of infrared radiation on sunburn and on phototoxic reactions to topical methoxsalen and anthracene in human volunteers. Prior heating of the skin caused suppression of the phototoxic response to methoxsalen as evidenced by an increase in the threshold erythema dose. Heat administered either before or after exposure to UV radiation had no detectable influence on sunburn erythema or on phototoxic reactions provoked by anthracene

  8. Investigation of the role of oncornavirus in radiation-induced osteosarcomas

    International Nuclear Information System (INIS)

    Frazier, M.E.; Park, J.F.; Jee, W.S.S.; Taylor, G.

    1975-01-01

    Viruses of the RNA tumor group are etiologic agents of spontaneously occurring neoplastic disease in a number of animal species. These oncornaviruses possess certain biochemical properties which permit them to be easily detected in infected cells, including RNA-instructed DNA polymerase (RIDP) and a closely associated 70S RNA genome in a cytoplasmic particulate fraction having a density of 1.15-1.20 g/ml. Tissues from three dogs with radiation-induced lung tumors and four dogs without tumors did not contain RIDP. However, RIDP was detected in materials prepared from five beagles with radiation-induced osteosarcomas. The presence of RIDP in these radiation-induced osteosarcomas can be considered indicative of retravirus or oncornavirus infection

  9. Radiation processing of polymer emulsion, (4). Radiation-induced emulsion polymerization of methyl methacrylate at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Makuuchi, Keizo; Katakai, Akio; Ito, Hiroshi; Hayakawa, Naohiro; Araki, Kunio (Japan Atomic Energy Research Inst., Takasaki, Gunma. Takasaki Radiation Chemistry Research Establishment)

    1983-06-01

    Methyl methacrylate was polymerized in emulsion by Co-60 ..gamma..-rays below 19 deg C in a batch reactor by using sodium lauryl sulfate as emulsifier. The conversion-time curves of the polymerization system showed two rate regions, i.e., a fact conversion rate in early stage, and a much slower rate in latter stage. The change in rate occurred at about 70 % conversion. The molecular weight of product polymer decreased with increasing conversion during the course of polymerization in latter stage, in contrast to the behavior in early stage. The distribution of the monomer in emulsion in latter stage was evaluated by nuclear magnetic resonance technique. The decrease of the molecular weight with conversion is due to the radiation-induced degradation of product polymer accelerated by the monomers absorbed in the polymer particles.

  10. Radiation-induced cationic curing of vinyl ethers

    International Nuclear Information System (INIS)

    Lapin, S.C.

    1992-01-01

    Recently there has been an increasing interest in nonacrylate radiation-curable coatings. Vinyl ethers are particularly reactive under cationic polymerization reaction conditions. The high efficiency of the photoacid initiators combined with the high reactivity of vinyl ether monomers makes this a potentially very useful system. This chapter discusses the preparation of vinyl ethers, introduces vinyl ether-functional monomers and oligomers, describes radiation-induced cationic polymerization of vinyl ethers, and discusses various coating systems. Throughout the chapter, an emphasis is placed on radiation-curable coating applications. 64 refs., 5 figs., 11 tabs

  11. Radiation-induced life-shortening and premature aging

    International Nuclear Information System (INIS)

    Walburg, H.E. Jr.

    1975-01-01

    Data from a number of studies on irradiated laboratory animals showed that almost none of the characteristic lesions associated with senescence that were studied adequately reflects a radiation effect analogous to premature aging. In fact, most of the age-related changes showed no effect of radiation at all, and many of those that did (for example, graying of hair, sterility, cataract formation) did not appear to be due to similar mechanisms. It is concluded that, in the light of more recent information, the hypothesis of radiation-induced premature aging requires reassessment. (80 references) (CH)

  12. Recovery from radiation induced changes in some protein end-products in the liver and blood serum of irradiated rats

    International Nuclear Information System (INIS)

    Elkashef, H.S.; Roushdy, H.M.; Saada, H.N.; Abdelsamie, M.A.

    1989-01-01

    When rats were subjected to whole body gamma-irradiation at the dose of 5.5 Gy it caused significant changes in the content of urea and creatine the serum at 7 and 14 days postirradiation. In the liver significant changes were observed in the content of urea, creatine and creatinine at all post-irradiation days except the third day for urea and seventh day for creatine. Ten days pre-irradiation of the rats a mixture of 5 mg testosterone propionate and 10 mg of vitamin E was intraperitoneally injected. The results indicated that this mixture could help in obtaining complete recovery for radiation induced changes in the content of urea in both liver and serum of irradiated protected rats. Also this mixture provided good protection and caused recovery from radiation induced changes in the liver creatine on the third and seventh days after irradiation. But for serum creatine, the recovery was observed only on the third post irradiation day. The applied radiation dose did not induce any significant changes in the level of serum creatinine, while a partial recovery was noticed for liver creatinine in irradiated protected rats. The recovery process seems to be related to the radiosensitivity of the animal tissue, with the chemical structure of the radioprotector substances and the estimated compounds as well as the post-irradiation time intervals.3 tab

  13. Radiation-induced apoptosis of neural precursors cell cultures: early modulation of the response mediated by reactive oxygen and nitrogen species (ROS/RNS)

    Energy Technology Data Exchange (ETDEWEB)

    Gisone, P.; Dubner, D.; Robello, E.; Michelin, S.; Perez, M. R.

    2004-07-01

    Apoptosis, the typical mode of radiation-induced cell death in developing Central Nervous System (CNS), is closely related with the oxidative status. Enhanced radiation-induced generation of ROS/RNS has been observed after exposures to low radiation doses leading to cellular amplification of signal transduction and further molecular and cellular radiation-responses. Moreover Nitric oxide (NO) and hydroxyl radical are implicated in dopaminergic neurotoxicity in different parading. This study is an attempt to address the participation of radiation-induced free radicals production, the contribution of endogenous NO generation, and the excitonic pathway, in the radiation-induced apoptosis of neural cortical precursors. Cortical cells obtained from at 17 gestational day (gd) were irradiated with doses from 0,2 Gy to 2 Gy at a dose-rate of 0.3 Gy/m. A significant decrease of Luminol-dependent Chemiluminescence was evident 30 m after irradiation reaching basal levels at 120 m follow for a tendency to increasing values Incubations with Superoxide Dismatuse (SOD) decreased significantly the chemiluminescence in irradiated samples NO content estimated by measuring the stable products NO{sub 2} and NO{sub 3} released to the culture medium in the same period, has shown a time-dependent accumulation from 1 h post-irradiation. the apoptosis, determined 24 h post-irradiation by flow cytometry, morphology and DNA fragmentation revealed a dose-effect relationship with significant differences from 0.4 Gy. The samples pre-treated with 10 mM of N-acetyl cysteine (NAC) a precursor of intracellular GSH synthesis, shown a significant decrease of the apoptosis. Apoptosis was significantly increased in irradiated cells after inhibition of nitric oxide synthase (NOS) byL-NAME. We conclude that ROS/RNS play a pivotal role in the early signaling pathways leading to a radiation-induced cell death. (Author) 40 refs.

  14. Radiation-induced apoptosis of neural precursors cell cultures: early modulation of the response mediated by reactive oxygen and nitrogen species (ROS/RNS)

    International Nuclear Information System (INIS)

    Gisone, P.; Dubner, D.; Robello, E.; Michelin, S.; Perez, M. R.

    2004-01-01

    Apoptosis, the typical mode of radiation-induced cell death in developing Central Nervous System (CNS), is closely related with the oxidative status. Enhanced radiation-induced generation of ROS/RNS has been observed after exposures to low radiation doses leading to cellular amplification of signal transduction and further molecular and cellular radiation-responses. Moreover Nitric oxide (NO) and hydroxyl radical are implicated in dopaminergic neurotoxicity in different parading. This study is an attempt to address the participation of radiation-induced free radicals production, the contribution of endogenous NO generation, and the excitonic pathway, in the radiation-induced apoptosis of neural cortical precursors. Cortical cells obtained from at 17 gestational day (gd) were irradiated with doses from 0,2 Gy to 2 Gy at a dose-rate of 0.3 Gy/m. A significant decrease of Luminol-dependent Chemiluminescence was evident 30 m after irradiation reaching basal levels at 120 m follow for a tendency to increasing values Incubations with Superoxide Dismatuse (SOD) decreased significantly the chemiluminescence in irradiated samples NO content estimated by measuring the stable products NO 2 and NO 3 released to the culture medium in the same period, has shown a time-dependent accumulation from 1 h post-irradiation. the apoptosis, determined 24 h post-irradiation by flow cytometry, morphology and DNA fragmentation revealed a dose-effect relationship with significant differences from 0.4 Gy. The samples pre-treated with 10 mM of N-acetyl cysteine (NAC) a precursor of intracellular GSH synthesis, shown a significant decrease of the apoptosis. Apoptosis was significantly increased in irradiated cells after inhibition of nitric oxide synthase (NOS) byL-NAME. We conclude that ROS/RNS play a pivotal role in the early signaling pathways leading to a radiation-induced cell death. (Author) 40 refs

  15. Radiation resistant modified polypropylene

    International Nuclear Information System (INIS)

    Bojarski, J.; Zimek, Z.

    1997-01-01

    Radiation technology for production of radiation resistant polypropylene for medical use has been presented. The method consists in radiation induced copolymerization of polypropylene with ethylene and addition of small amount of copolymer of polyethylene and vinyl acetate. The material of proposed composition has a very good mechanical properties and elevated radiation resistivity decided on possibility of radiosterilization of products made of this material and designed for medical use. 3 figs, 3 tabs

  16. Radiation-induced electron paramagnetic resonance signal and soybean isoflavones content

    International Nuclear Information System (INIS)

    Oliveira, Marcos R.R. de; Mandarino, José M.G.; Mastro, Nelida L. del

    2012-01-01

    Electron Paramagnetic Resonance (EPR) is a well-known spectroscopic technique that detects paramagnetic centers and can detect free radicals with high sensitivity. In food, free radicals can be generated by several commonly used industrial processes, such as radiosterilization or heat treatment. EPR spectroscopy is used to detect radioinduced free radicals in food. In this work the relation between EPR signal induced by gamma irradiation treatment and soybean isoflavones content was investigated. Present results did not show correlation between total isoflavones content and the EPR signal. Nevertheless, some isoflavone contents had a negative correlation with the radiation-induced EPR signal. - Highlights: ► Electron Paramagnetic Resonance (EPR) detects free radicals. ► Ionizing radiation as free radicals inducer. ► Total soybean isoflvones do not correlate with radiation-induced EPR intensity but a soybean glucosyl glucoside isoflavone does.

  17. Total-dose radiation-induced degradation of thin film ferroelectric capacitors

    International Nuclear Information System (INIS)

    Schwank, J.R.; Nasby, R.D.; Miller, S.L.; Rodgers, M.S.; Dressendorfer, P.V.

    1990-01-01

    Thin film PbZr y Ti 1-y O 3 (PZT) ferroelectric memories offer the potential for radiation-hardened, high-speed nonvolatile memories with good retention and fatigue properties. In this paper we explore in detail the radiation hardness of PZT ferroelectric capacitors. Ferroelectric capacitors were irradiated using x-ray and Co-60 sources to dose levels up to 16 Mrad(Si). The capacitors were characterized for their memory properties both before and after irradiation. The radiation hardness was process dependent. Three out of four processes resulted in capacitors that showed less than 30% radiation-induced degradation in retained polarization charge and remanent polarization after irradiating to 16 Mrad(Si). On the other hand, one of the processes showed significant radiation-induced degradation in retained polarization charge and remanent polarization at dose levels above 1 Mrad(Si). The decrease in retained polarization charge appears to be due to an alteration of the switching characteristics of the ferroelectric due to changes in the internal fields. The radiation-induced degradation is recoverable by a postirradiation biased anneal and can be prevented entirely if devices are cycled during irradiation. The authors have developed a model to simulate the observed degradation

  18. The response of human skin commensal bacteria as a reflection of UV radiation: UV-B decreases porphyrin production.

    Directory of Open Access Journals (Sweden)

    Yanhan Wang

    Full Text Available Recent global radiation fears reflect the urgent need for a new modality that can simply determine if people are in a radiation risk of developing cancer and other illnesses. Ultraviolet (UV radiation has been thought to be the major risk factor for most skin cancers. Although various biomarkers derived from the responses of human cells have been revealed, detection of these biomarkers is cumbersome, probably requires taking live human tissues, and varies significantly depending on human immune status. Here we hypothesize that the reaction of Propionibacterium acnes (P. acnes, a human resident skin commensal, to UV radiation can serve as early surrogate markers for radiation risk because the bacteria are immediately responsive to radiation. In addition, the bacteria can be readily accessible and exposed to the same field of radiation as human body. To test our hypothesis, P. acnes was exposed to UV-B radiation. The production of porphyrins in P. acnes was significantly reduced with increasing doses of UV-B. The porphyrin reduction can be detected in both P. acnes and human skin bacterial isolates. Exposure of UV-B to P. acnes- inoculated mice led to a significant decrease in porphyrin production in a single colony of P. acnes and simultaneously induced the formation of cyclobutane pyrimidine dimers (CPD in the epidermal layers of mouse skin. Mass spectrometric analysis via a linear trap quadrupole (LTQ-Orbitrap XL showed that five peptides including an internal peptide (THLPTGIVVSCQNER of a peptide chain release factor 2 (RF2 were oxidized by UV-B. Seven peptides including three internal peptides of 60 kDa chaperonin 1 were de-oxidized by UV-B. When compared to UV-B, gamma radiation also decreased the porphyrin production of P. acnes in a dose-dependent manner, but induced a different signature of protein oxidation/de-oxidation. We highlight that uncovering response of skin microbiome to radiation will facilitate the development of pre

  19. The response of human skin commensal bacteria as a reflection of UV radiation: UV-B decreases porphyrin production.

    Science.gov (United States)

    Wang, Yanhan; Zhu, Wenhong; Shu, Muya; Jiang, Yong; Gallo, Richard L; Liu, Yu-Tsueng; Huang, Chun-Ming

    2012-01-01

    Recent global radiation fears reflect the urgent need for a new modality that can simply determine if people are in a radiation risk of developing cancer and other illnesses. Ultraviolet (UV) radiation has been thought to be the major risk factor for most skin cancers. Although various biomarkers derived from the responses of human cells have been revealed, detection of these biomarkers is cumbersome, probably requires taking live human tissues, and varies significantly depending on human immune status. Here we hypothesize that the reaction of Propionibacterium acnes (P. acnes), a human resident skin commensal, to UV radiation can serve as early surrogate markers for radiation risk because the bacteria are immediately responsive to radiation. In addition, the bacteria can be readily accessible and exposed to the same field of radiation as human body. To test our hypothesis, P. acnes was exposed to UV-B radiation. The production of porphyrins in P. acnes was significantly reduced with increasing doses of UV-B. The porphyrin reduction can be detected in both P. acnes and human skin bacterial isolates. Exposure of UV-B to P. acnes- inoculated mice led to a significant decrease in porphyrin production in a single colony of P. acnes and simultaneously induced the formation of cyclobutane pyrimidine dimers (CPD) in the epidermal layers of mouse skin. Mass spectrometric analysis via a linear trap quadrupole (LTQ)-Orbitrap XL showed that five peptides including an internal peptide (THLPTGIVVSCQNER) of a peptide chain release factor 2 (RF2) were oxidized by UV-B. Seven peptides including three internal peptides of 60 kDa chaperonin 1 were de-oxidized by UV-B. When compared to UV-B, gamma radiation also decreased the porphyrin production of P. acnes in a dose-dependent manner, but induced a different signature of protein oxidation/de-oxidation. We highlight that uncovering response of skin microbiome to radiation will facilitate the development of pre-symptomatic diagnosis

  20. Effects of an Amifostine analogue on radiation induced lung inflammation and fibrosis

    International Nuclear Information System (INIS)

    Arora, Aastha; Bhuria, Vikas; Soni, Ravi; Singh, Saurabh; Hazari, Puja Panwar; Bhatt, Anant Narayan; Dwarakanath, B.S.; Pathak, Uma; Mathur, Shweta; Sandhir, Rajat

    2014-01-01

    Radiation-induced pulmonary toxicity causes significant morbidity and mortality in patients irradiated for thoracic malignancies as well as in victims of accidental radiation exposure. We have recently established the efficacy of an analogue of Amifostine (DRDE-30) in reducing the mortality of whole body irradiated mice. The widely used radioprotector Amifostine has been found to reduce the incidence of radiation induced pneumonitis during radiation therapy for non small cell lung carcinoma. In the present study, we investigated the potential of DRDE-30 in ameliorating the radiation induced lung damage. Intra-peritoneal administration of DRDE-30 at 220 mg/kg b.wt 30 min. prior to 13.5 Gy thoracic radiation enhanced the 24-month survival of C57BL/6 mice to 80% compared to 0% with radiation alone. Reduced protein content and cell number in the broncheo-alveolar lavage fluid suggested reduction in radiation induced vascular permeability in DRDE-30 treated mice. Higher levels of MnSOD and Catalase observed under these conditions indicated that strengthening of the anti-oxidant defense system by DRDE-30 could also contribute to the protection against radiation induced lung damage. Reduced levels of p-p38 observed under these conditions suggested down-regulation of the p38/MAP kinase pathway as one of the plausible mechanisms underlying anti-inflammatory effects of DRDE-30, while lower levels of Vimentin seen, indicated inhibition of epithelial to mesenchymal transition revealing its anti-fibrotic effect as well. Structural analysis with X-ray CT indicated comparable lung architecture in control and drug treated mice in terms of reduced opacity, which correlated well with the lung morphology (H and E staining) and reduced collagen deposition (trichrome staining). These results demonstrate the potential of DRDE-30 in reducing radiation induced pulmonary toxicity by attenuating the inflammatory and fibrotic responses. (author)

  1. 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.)

  2. Radiation defect production in quartz crystals with various structure perfectness degree; Radiatsionnoe defektoobrazovanie v kristallakh kvartsa s razlichnoj stepen`yu sovershenstva struktury

    Energy Technology Data Exchange (ETDEWEB)

    Khushvakov, O B

    1992-01-01

    Radiation defects production processes in pure and doped quartz crystals with various structure defectness, caused by preliminary irradiation with neutrons, protons, deuterons and {alpha}-particles, during various electron excitation densities were investigated. The distribution of colour centres along the thickness of irradiated quartz crystals was measured. It was supposed that colour centres are produced on account of inelastic energy losses as the result of collective decay of two or more interacting excitons. It was shown that in quartz crystals under the actions of protons with overthreshold energy 18 MeV and electrons with subthreshold energy 100 keV the same structure defects are formed. It was established that radiation defect production process has two stages. The first stage reveals radiation defects produced by preliminary irradiation. The second one reveals additional intrinsic defects formed under the action of gamma-rays and electrons. The probability dependence of defect production on neutron fluence and masses of incident particles was studied. It was supposed that the creation of additional defects in preliminary irradiated crystals is due to non-radiative decay of electron excitations near radiation-induced defects. It was shown that increase of impurity concentration leads to rate growth of accumulation of radiation induced defects. (A.A.D.) 15 refs. 4 figs.

  3. Radiation sterilization of some pharmaceutical preparations and medical products

    International Nuclear Information System (INIS)

    Tashmetov, M.Yu.; Makhkamov, Sh.M.; Urinov, Sh.S.; Turaev, A.S.; Sultanov, M.S.; Inagomov, Kh.S.

    2006-01-01

    Full text: In connection with intensive development of pharmacology and medical techniques, use of the products contacting to blood, with the internal environment of an organism, with wound surface, with mucous membranes and skin there were high requirements to sterility of pharmaceutical preparations and medical products. Traditional methods of sterilization (heat treatment, gas processing and processing the ferry) have some restrictions in application, and not insufficient degree of sterilization required for pharmaceutical preparations and medical products. Thermal processing can lead to degradation of structure (medicine), mechanical changes and loss of medical properties. Besides, it is impossible to carry out sterilization of many pharmaceutical preparations by a method of heat treatment. Sterilization of products in packing is very complicated, because sterilization temperature of packing and a product is different. Gas processing is basically applied to sterilization of medical products (syringes, bandage, cotton wools, etc.). However, the degree of sterility is low, because of rather low ability and heterogeneity of sterilizing substance. Sterilization in packing represents special difficulty and demands additional charges related with delivery of the purified gas from abroad. Last years alongside with known technological methods of sterilization of medical products and pharmaceutical preparations radiating methods of processing have found wide application. Use of electronic bunches with the moderate energy and various isotopes became a basis for formation and development of a new direction in the medicine, called by 'radiation sterilization'. The radiation technology is highly harmless and economic, not polluting substance and surrounding space. Unlike the specified traditional methods, radiating processing of products by the isotope 60 Co, radiating the gamma quantum, has unique opportunities - high penetrability in substance, providing uniformity of

  4. Radiation-induced-radioresistance: mechanisms and modification radioprotection

    International Nuclear Information System (INIS)

    Bala, Madhu

    2005-01-01

    Full text: The term radiation-induced-radioresistance (RIR) has been chosen to explain a particular class of resistance against lethal doses of radiation, which is transient and is induced by pre-exposure to low doses of radiation. This is a genetically governed phenomenon and is different from adaptation which in one of its several senses, refers to evolutionary transformation into new behavioural patterns. RIR is understood to be an evolutionarily conserved fundamental cellular defense mechanism. Small doses of radiation acting as stress stimuli evoke a concerted action of molecular pathways which help the organism to cope-up with the genotoxic effects of lethal doses of radiation given subsequently. Such molecular pathways are a complex interplay of genetic and biochemical entities and are increasingly becoming the focus of research world over. Most of our information on this subject has been gathered from prokaryotes, simpler eukaryotes, human cells and the epidemiological studies. A number of genes such as GADD 45, CDKN1A, PBP74, DIR1, DDR have been reported by to participate in RIR. However, till date, the mechanism of RIR remain poorly understood. In this deliberation some of our findings on mechanisms of RIR will be presented. Further, modification of RIR by a metabolic modifier, presently under clinical investigations for tumor radiotherapy, will also be presented

  5. Radiation-induced malignant tumours: a specific cytogenetic profile?

    International Nuclear Information System (INIS)

    Chauveinc, L.; Gaboriaux, G.; Dutrillaux, A. M.; Dutrillaux, B.; Chauveinc, L.; Ricoul, M.; Sabatier, L.; Dutrillaux, B.

    1997-01-01

    To date, there is no criterion enabling to determine the spontaneous or radio-induced origin of malignant tumour occurring in a previously irradiated patient. Biological studies are rare. The cytogenetic data which could be found in the literature for eleven radio-induced tumours suggest that aneuploidies and polyclonality are frequent events. We studied, by R-Banding cytogenetic technique, five patients with short-term cultures (3 cases), short and long-term cultures (1 case) and xeno-grafting on nude pattern a high rate of balanced translocations, numerous random break points and a polyclonal evolution (10 clones). All other tumours, including the xeno-grafting sarcoma, had a monoclonal profile with complex karyotypes, hypo-diploid formulas and many deletions. These results show that the mechanism of radiation-induced tumours frequently involves chromosomes losses and deletions. The most likely explanation is that these alterations unmask radiation induced recessive mutations of tumour suppressor genes. (authors)

  6. Hematological Changes Induced by Mercury Ions and Ionizing Radiation in Experimental Animals

    International Nuclear Information System (INIS)

    Kim, Jin-Kyu; Lee, Yun-Jong; Choi, Dae-Seong; Kim, Ji-Hyang; Cebulska-Wasilewska, Antonina

    2006-01-01

    Toxic metals such as lead, chromium, cadmium, mercury and arsenic are widely found in our environment. Humans are exposed to these metals from numerous sources, including contaminated air, water, soil and food. Mercury, one of the most diffused and hazardous organ specific environmental contaminants, exists in a wide variety of physical and chemical states, each of which has unique characteristics for a target organ specificity. Although reports indicate that mercury induces deleterious damage, little is known about its effects on living organisms. Ionizing radiation, an extensively used therapeutic modality in oncology, not only eradicates neoplastic cells but also generates inevitable side effects for normal tissues. Such biological effects are made through the production of reactive oxygen species which include a superoxide anion, a hydroxyl radical and a hydrogen peroxide. These reactive species may contribute to the radiation-induced cytotoxicity (e.g., chromosome aberrations, protein oxidation, and muscle injury) and to the metabolic and morphologic changes (e.g., increased muscle proteolysis and changes in the central nervous system) in animals and humans. In the present study, radioimmunoassay of the cortisol in the serum and the analysis of the hematological components and enzymes related to a tissue injury were carried out to evaluate the effects of mercury chloride in comparison with those of ionizing radiation

  7. Hematological Changes Induced by Mercury Ions and Ionizing Radiation in Experimental Animals

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin-Kyu; Lee, Yun-Jong; Choi, Dae-Seong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Kim, Ji-Hyang [Biotechnology Research Institute, Seoul (Korea, Republic of); Cebulska-Wasilewska, Antonina [The Henryk Niewodniczanski Institute of Nuclear Physics, Krakow (Poland)

    2006-07-01

    Toxic metals such as lead, chromium, cadmium, mercury and arsenic are widely found in our environment. Humans are exposed to these metals from numerous sources, including contaminated air, water, soil and food. Mercury, one of the most diffused and hazardous organ specific environmental contaminants, exists in a wide variety of physical and chemical states, each of which has unique characteristics for a target organ specificity. Although reports indicate that mercury induces deleterious damage, little is known about its effects on living organisms. Ionizing radiation, an extensively used therapeutic modality in oncology, not only eradicates neoplastic cells but also generates inevitable side effects for normal tissues. Such biological effects are made through the production of reactive oxygen species which include a superoxide anion, a hydroxyl radical and a hydrogen peroxide. These reactive species may contribute to the radiation-induced cytotoxicity (e.g., chromosome aberrations, protein oxidation, and muscle injury) and to the metabolic and morphologic changes (e.g., increased muscle proteolysis and changes in the central nervous system) in animals and humans. In the present study, radioimmunoassay of the cortisol in the serum and the analysis of the hematological components and enzymes related to a tissue injury were carried out to evaluate the effects of mercury chloride in comparison with those of ionizing radiation.

  8. Effects of ceramide inhibition on radiation-induced apoptosis in human leukemia MOLT-4 cells

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Eriko; Inanami, Osamu; Asanuma, Taketoshi; Kuwabara, Mikinori [Hokkaido Univ., Graduate School of Veterinary Medicine, Sapporo, Hokkaido (Japan)

    2006-03-15

    In the present study, using inhibitors of ceramide synthase (fumonisin B{sub 1}), ketosphinganine synthetase (L-cycloserine), acid sphingomyelinase (D609 and desipramine) and neutral sphingomyelinase (GW4869), the role of ceramide in X-ray-induced apoptosis was investigated in MOLT-4 cells. The diacylglycerol kinase (DGK) assay showed that the intracellular concentration of ceramide increased time-dependently after X irradiation of cells, and this radiation-induced accumulation of ceramide did not occur prior to the appearance of apoptotic cells. Treatment with D609 significantly inhibited radiation-induced apoptosis, but did not inhibit the increase of intracellular ceramide. Treatment with desipramine or GW4869 prevented neither radiation-induced apoptosis nor the induced increase of ceramide. On the other hand, fumonisin B{sub 1} and L-cycloserine had no effect on the radiation-induced induction of apoptosis, in spite of significant inhibition of the radiation-induced ceramide. From these results, it was suggested that the increase of the intracellular concentration of ceramide was not essential for radiation-induced apoptosis in MOLT-4 cells. (author)

  9. Effects of ceramide inhibition on radiation-induced apoptosis in human leukemia MOLT-4 cells

    International Nuclear Information System (INIS)

    Takahashi, Eriko; Inanami, Osamu; Asanuma, Taketoshi; Kuwabara, Mikinori

    2006-01-01

    In the present study, using inhibitors of ceramide synthase (fumonisin B 1 ), ketosphinganine synthetase (L-cycloserine), acid sphingomyelinase (D609 and desipramine) and neutral sphingomyelinase (GW4869), the role of ceramide in X-ray-induced apoptosis was investigated in MOLT-4 cells. The diacylglycerol kinase (DGK) assay showed that the intracellular concentration of ceramide increased time-dependently after X irradiation of cells, and this radiation-induced accumulation of ceramide did not occur prior to the appearance of apoptotic cells. Treatment with D609 significantly inhibited radiation-induced apoptosis, but did not inhibit the increase of intracellular ceramide. Treatment with desipramine or GW4869 prevented neither radiation-induced apoptosis nor the induced increase of ceramide. On the other hand, fumonisin B 1 and L-cycloserine had no effect on the radiation-induced induction of apoptosis, in spite of significant inhibition of the radiation-induced ceramide. From these results, it was suggested that the increase of the intracellular concentration of ceramide was not essential for radiation-induced apoptosis in MOLT-4 cells. (author)

  10. Reconstructed Solar-Induced Fluorescence: A Machine Learning Vegetation Product Based on MODIS Surface Reflectance to Reproduce GOME-2 Solar-Induced Fluorescence

    Science.gov (United States)

    Gentine, P.; Alemohammad, S. H.

    2018-04-01

    Solar-induced fluorescence (SIF) observations from space have resulted in major advancements in estimating gross primary productivity (GPP). However, current SIF observations remain spatially coarse, infrequent, and noisy. Here we develop a machine learning approach using surface reflectances from Moderate Resolution Imaging Spectroradiometer (MODIS) channels to reproduce SIF normalized by clear sky surface irradiance from the Global Ozone Monitoring Experiment-2 (GOME-2). The resulting product is a proxy for ecosystem photosynthetically active radiation absorbed by chlorophyll (fAPARCh). Multiplying this new product with a MODIS estimate of photosynthetically active radiation provides a new MODIS-only reconstruction of SIF called Reconstructed SIF (RSIF). RSIF exhibits much higher seasonal and interannual correlation than the original SIF when compared with eddy covariance estimates of GPP and two reference global GPP products, especially in dry and cold regions. RSIF also reproduces intense productivity regions such as the U.S. Corn Belt contrary to typical vegetation indices and similarly to SIF.

  11. Glycoalkaloids and phenolic compounds in gamma irradiated potatoes; a food irradiation study on radiation induced stress in vegetable products

    NARCIS (Netherlands)

    Bergers, W.W.A.

    1980-01-01

    Irradiation is a recent preservation method. With the aid of ionizing radiation microorganisms in food can be killed or specific physiological processes in vegetable products can be influenced.

    In order to study the effects of metabolic radiation stress on quantitative chemical changes in

  12. Helium production for 0.8-2.5 GeV proton induced spallation reactions, damage induced in metallic window materials

    International Nuclear Information System (INIS)

    Hilscher, D.; Herbach, C.-M.; Jahnke, U.; Tishchenko, V.; Enke, M.; Filges, D.; Goldenbaum, F.; Neef, R.-D.; Nuenighoff, K.; Paul, N.; Schaal, H.; Sterzenbach, G.; Letourneau, A.; Boehm, A.; Galin, J.; Lott, B.; Peghaire, A.; Pienkowski, L.

    2001-01-01

    Production cross-sections for neutrons and charged particles as well as excitation energy distributions in spallation reactions were measured recently by the NESSI-collaboration and have been employed to test different intra nuclear cascade models and the subsequent evaporation. The INCL/GEMINI code, which describes best the experimental data has been employed to calculate the damage cross-sections in Fe and Ta as well as the He/dpa ratio as a function of proton energy. For the same amount of neutron production in a typical target of a spallation neutron source the proton beam induced radiation damage in an Fe window is shown to decrease almost linearly with proton energy. For heavier materials such as Ta a similar decrease of the radiation damage is found only for energies above about 3 GeV

  13. Free radicals in wood induced by γ-radiation

    International Nuclear Information System (INIS)

    Xu Honglin; Zhang Wenhui

    1994-01-01

    The free radicals in wood induced by γ-radiation were studied by electron spin resonance. The fine structure of the ESR signal from sawdust samples irradiated could be resolved into various radicals. These free radicals have a very long lifetime. The major spectrum for the free radicals will exponentially increased along with the radiation dose according to Y 1-Exp(-α a D). The intensity of radiation radicals is dependent on tree species. The stronger the intensity of mechanic free radicals is, the stronger the intensity of radiation free radicals

  14. Adriamycin-radiation combinations: drug induced delayed gastrointestinal radiosensitivity

    International Nuclear Information System (INIS)

    Schenken, L.L.; Burholt, D.R.; Kovacs, C.J.

    1979-01-01

    The administration of Adriamycin (ADR) results in acute short-term reductions in cell production within the gastrointestinal mucosa. Interactions between ADR doses and radiation appear minimized as the inter-treatment time interval expands to five days. However, as the times between drug administration and abdominal radiation exposure are further lengthened (from 14 to 49 days), a progressively severe defect in post-irradiation mucosal cell production is noted. Although the mucosa appears abnormal histologically and crypt cell cellularity and cell production are normal, the proliferative response following radiation is reduced by as much as 50% if ADR is given 7 weeks prior to the radiation exposure. We postulate that this effect is a manifestation of latent damage to the stem cell compartment within the crypt or that secondary support systems such as mucosal vascularity have been compromised by ADR

  15. Laser radiation effect on radiation-induced defects in heavy ion tracks in dielectrics

    International Nuclear Information System (INIS)

    Egorov, A.N.; Zhiryakov, B.M.; Kushin, V.V.; Lyapidevskij, V.K.; Khokhlov, N.B.

    1988-01-01

    Possibility of laser radiation resonance effect on radiation-induced defects in heavy ion tracks in dielectric materials is investigated. Absorption spectra in infrared, visible and ultraviolet ranges for cellulose nitrate samples irradiated by 6 MeV/nucleon 58 Ni ions and reactor gamma radiation are measured. Absorption spectra for irradiated and reference samples are presented. Two absorption bands λ 1 =0.33 μm (E 1 =3.9 eV) and λ 2 =0.72 μm (E 2 =1.7 eV) are detected. Etching rate decrease in a track under laser radiation effect is noticed. 3 refs.; 1 fig

  16. Ionizing radiation for insect control in grain and grain products

    International Nuclear Information System (INIS)

    Tilton, E.W.; Brower, J.H.

    1987-01-01

    A technical review summarizes and discusses information on various aspects of the use of ionizing radiation for the control of insect infestation in grains and grain products. Topics include: the effects of ionizing radiation on insects infesting stored-grain products; the 2 main types of irradiators (electron accelerators; radioisotopes (e.g.: Co-60; Cs-137); dosimetry systems and methodology; variations in radiation resistance by stored-product pests; the proper selection of radiation dose; the effects of combining various treatments (temperature, infrared/microwave radiation, hypoxia, chemicals) with ionizing radiation; sublethal radiation for controlling bulk grain insects; the feeding capacity of irradiated insects; the susceptibility of insecticide-resistant insects to ionizing radiation; and the possible resistance of insects to ionizing radiation. Practical aspects of removing insects from irradiated grain also are discussed

  17. Effect of sulfhydryls on potentiation of radiation-induced cell lethality by substituted anthraquinones

    International Nuclear Information System (INIS)

    Kimler, B.F.

    1984-01-01

    The effects of various substituted anthraquinones (SAQ's) and Adriamycin (ADR) were investigated in cultured Chinese hamster V79 cells. These drugs cause a potentiation of radiation-induced cell lethality, albeit by different mechanisms. One possibility is that these components operate through the production of free radicals which then produce DNA strand breaks and crosslinks. If so, then one should be able to change the degree of cell kill by modifying sulfhydryl (SH) levels such that free radical processes are altered. Diamide, buthionine-S, R-sulfoximine, and N-ethylmaleimide (NEM) were used to reduce intracellular SH levels. Cysteamine and dithiotheitol were used to increase SH levels. In general, altered SH levels did not affect SAQ-induced cytotoxicity at low drug concentrations. When drug-tested cells were also irradiated, survival levels were generally those predicted from assuming purely additive interactions. On the other hand, survival after treatment with high concentrations of ADR and one other SAQ were decreased by concomitant treatment with NEM. Since altered SH levels do not produce changes in the potentiation of radiation-induced cell lethality by SAQs, it is concluded that free radicals are not involved in this potentiation. A free radical-mediated process may be involved in the cytotoxicity induced by ADR and other SAQs; however, it is not a simple process

  18. Anti-apoptotic peptides protect against radiation-induced cell death

    International Nuclear Information System (INIS)

    McConnell, Kevin W.; Muenzer, Jared T.; Chang, Kathy C.; Davis, Chris G.; McDunn, Jonathan E.; Coopersmith, Craig M.; Hilliard, Carolyn A.; Hotchkiss, Richard S.; Grigsby, Perry W.; Hunt, Clayton R.

    2007-01-01

    The risk of terrorist attacks utilizing either nuclear or radiological weapons has raised concerns about the current lack of effective radioprotectants. Here it is demonstrated that the BH4 peptide domain of the anti-apoptotic protein Bcl-xL can be delivered to cells by covalent attachment to the TAT peptide transduction domain (TAT-BH4) and provide protection in vitro and in vivo from radiation-induced apoptotic cell death. Isolated human lymphocytes treated with TAT-BH4 were protected against apoptosis following exposure to 15 Gy radiation. In mice exposed to 5 Gy radiation, TAT-BH4 treatment protected splenocytes and thymocytes from radiation-induced apoptotic cell death. Most importantly, in vivo radiation protection was observed in mice whether TAT-BH4 treatment was given prior to or after irradiation. Thus, by targeting steps within the apoptosis signaling pathway it is possible to develop post-exposure treatments to protect radio-sensitive tissues

  19. Attenuation of a radiation-induced conditioned taste aversion after the development of ethanol tolerance

    International Nuclear Information System (INIS)

    Hunt, W.A.; Rabin, B.M.

    1988-01-01

    An attempt to reduce a radiation-induced conditioned taste aversion (CTA) was undertaken by rendering animals tolerant to ethanol. Ethanol tolerance, developed over 5 days, was sufficient to block a radiation-induced taste aversion, as well as an ethanol-induced CTA. Several intermittent doses of ethanol, which did not induce tolerance but removed the novelty of the conditioning stimulus, blocked an ethanol-induced CTA but not the radiation-induced CTA. A CTA induced by doses of radiation up to 500 rads was attenuated. These data suggest that radioprotection developing in association with ethanol tolerance is a result of a physiological response to the chronic presence of ethanol not to the ethanol itself

  20. PAI-1-dependent endothelial cell death determines severity of radiation-induced intestinal injury.

    Directory of Open Access Journals (Sweden)

    Rym Abderrahmani

    Full Text Available Normal tissue toxicity still remains a dose-limiting factor in clinical radiation therapy. Recently, plasminogen activator inhibitor type 1 (SERPINE1/PAI-1 was reported as an essential mediator of late radiation-induced intestinal injury. However, it is not clear whether PAI-1 plays a role in acute radiation-induced intestinal damage and we hypothesized that PAI-1 may play a role in the endothelium radiosensitivity. In vivo, in a model of radiation enteropathy in PAI-1 -/- mice, apoptosis of radiosensitive compartments, epithelial and microvascular endothelium was quantified. In vitro, the role of PAI-1 in the radiation-induced endothelial cells (ECs death was investigated. The level of apoptotic ECs is lower in PAI-1 -/- compared with Wt mice after irradiation. This is associated with a conserved microvascular density and consequently with a better mucosal integrity in PAI-1 -/- mice. In vitro, irradiation rapidly stimulates PAI-1 expression in ECs and radiation sensitivity is increased in ECs that stably overexpress PAI-1, whereas PAI-1 knockdown increases EC survival after irradiation. Moreover, ECs prepared from PAI-1 -/- mice are more resistant to radiation-induced cell death than Wt ECs and this is associated with activation of the Akt pathway. This study demonstrates that PAI-1 plays a key role in radiation-induced EC death in the intestine and suggests that this contributes strongly to the progression of radiation-induced intestinal injury.

  1. Breast cancer induced by protracted radiation exposures

    International Nuclear Information System (INIS)

    Elkind, M.M.

    1997-01-01

    The experience at Hiroshima/Nagasaki demonstrated that breast cancer can be induced by single doses of ionizing radiation following latencies of 10-40 years. Several epidemiological studies, usually involving ancillary low-LET radiation to the breast, have demonstrated that breast cancer can be induced by protracted exposures, with similar latencies, and with similar dependencies on dose. Radiobiologically these results suggest that the target cells involved were deficient in repair of low-LET damage even when the protraction was over months to years. Since three-quarters of breast tumors originate in the ducts where their proliferation is controlled by menstrual-cycle timed estrogen/progesterone secretions, these cells periodically were in cycle. Thus, the two main elements of a conceptual model for radon-induced lung cancer -- kinetics and deficient repair -- are satisfied. The model indicates that breast cancer could be the cumulative effect of protracted small exposures, the risk from any one of which ordinarily would be quite small. (author)

  2. Radiation methods in dairy production and processing

    International Nuclear Information System (INIS)

    Ganguli, N.C.

    1975-01-01

    Various uses of radiotracers and radiation in dairy technology are described. In dairy production, radiotracers are used for studying: (1) rumen metabolism leading to protein synthesis (2) total body water, blood volume and sodium (3) minerals metabolism (4) relation between climatic stress and thyroid functioning of dairy animals (5) volume of milk in mammary glands (6) hormone level in dairy animals and (7) spermatozoa metabolism. In dairy processing, radiotracers are used for studying: (1) compositional analysis of milk and milk products and (2) efficiency of cleaning agents for cleaning dairy equipment. Ionizing radiation is used for: (1) preservation of milk and milk products and (2) sterilization of packaging materials. Radiation source has been used to monitor the over-run in ice-cream and the fill control for fluid in papar cartons. (M.G.B.)

  3. Radiation-induced void swelling in metals and alloys

    International Nuclear Information System (INIS)

    Zelinskij, V.F.; Neklyudov, I.M.; Ozhigov, L.S.; Reznichenko, Eh.A.; Rozhkov, V.V.; Chernyaeva, T.T.

    1979-01-01

    Main regularities in the development of radiation-induced void swelling are considered. Special attention is paid to consideration of a possibility to obtain information on material behaviour under conditions of reactor irradiation proceeding from the data of simulation experiments and to methods of rate control, for the processes which occur in material during irradiation and further annealing by the way of rationalized alloying, of thermomechanical treatment and programmed change of irradiation conditions under operation. Problems of initiation and growth of voids in irradiated materials are discussed as well as the ways to decrease the rate of radiation-induced void swelling

  4. Radiation-induced attenuation in integrated optical materials

    International Nuclear Information System (INIS)

    Evans, B.D.

    1989-01-01

    This paper reports that three materials commonly employed in opto-electronic integrated circuits evaluated for radiation-induced optical attenuation in the range 300 nm to 3000 nm. These include optically clear epoxy and crystalline lithium niobate after Co-60 exposure and crystalline tellurium dioxide after mixed gamma/fast-neutron exposure. In all these materials, however, induced loss was restricted to shorter wavelengths; attenuation induced at the telecommunications windows near 850, 1300 and 1550 nm was <0.1 dB/cm

  5. Second primary tumor and radiation induced neoplasma in the uterine cancer

    International Nuclear Information System (INIS)

    Sakurai, Tomoyasu; Nishio, Masamichi; Kagami, Yoshikazu; Murakami, Yoshitaka; Narimatsu, Naoto; Kanemoto, Toshitaka

    1984-01-01

    This report is concerned with multiple primary cancers developing in invasive uterine cancer. Second primary tumors were recorded 27 women with a total of 30 non-uterine cancer (exception of radiation-induced cancer). 17 patients of radiation-induced neoplasm were observed (Rectal cancer 4, soft part sarcoma 4, cancer of urinary bladder 3, bone tumor 3, uterin cancer 2 and cancer of Vulva 1). One case is 4 legions (corpus, sigma, thymoma and stomach), 2 cases are 3 lesions (uterine cervix, stomach and maxillay siuis: uterine cervix, thyroidal gland and radiation-induced soft part sarcoma). Only 5 of these 17 patients were known irradiated dose (50 Gy--55 Gy), however others unknown. The mean latent periods of 17 cases of radiation induced neoplasms are 19.4 years. 16 patients of late second cancers of the cervix appearing from 11 to 36 years (average 19.5 years) after initial radiotherapy were recorded. (author)

  6. Establishment of a Radiation-Induced Fibrosis Model in BALB/c Mice

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Seung Hee; Lee, Sang Wook; Moon, Soo Young; Oh, Jeong Yoon; Yang, Youn Joo; Park, Jin Hong [Dept. of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2010-11-15

    Although radiation-induced fibrosis is one of the common sequelae occurring after irradiation of skin and soft tissues, the treatment methods are not well standardized. This study aimed to establish the skin fibrosis mouse model by fractionated radiation for the further mechanism studies or testing the efficacy of therapeutic candidates. The right hind limbs of BALB/c mice received two fractions of 20 Gy using a therapeutic linear accelerator. Early skin damages were scored and tissue fibrosis was assessed by the measurement of a leg extension. Morphological changes were assessed by H and E staining and by Masson's Trichrome staining. TGF-{beta}1 expression from soft tissues was also detected by immunohistochemistry and PCR. Two fractions of 20 Gy irradiation were demonstrated as being enough to induce early skin damage effects such as erythema, mild skin dryness, dry and wet desquamation within several weeks of radiation. After 13 weeks of irradiation, the average radiation-induced leg contraction was 11.1 {+-} 6.2 mm. Morphologic changes in irradiated skin biopsies exhibited disorganized collagen and extracellular matrix fibers, as well as the accumulation of myofibroblasts compared to the non-irradiated skin. Moreover, TGF-{beta}1 expression in tissue was increased by radiation. These results show that two fractions of 20 Gy irradiation can induce skin fibrosis in BALB/c mice accompanied by other common characteristics of skin damages. This animal model can be a useful tool for studying skin fibrosis induced by radiation.

  7. Function and regulation of ATF 3 expression induced by ionizing radiation

    International Nuclear Information System (INIS)

    Fan, Feiyue; Wang, Yong; Du, Liqin; Zhan, Qimin

    2008-01-01

    Full text: Ionizing radiation results in a series of damages of mammalian cells as a genotoxic stress. There are some genes expressed after cells damaged, in which ATF 3, a member of ATF/CREB family of transcription factors, is one of them. In this report, we demonstrate that ATF 3 can be induced by ionizing radiation. The induction of ATF 3 protein requires normal status of p53 function in cells. There are some quantitative relationships between ATF 3 induction and dosages of radiation or time post-irradiation. In another word, ATF 3 expression induced by ionizing radiation present dose- and time-dependent. The regulation of ATF 3 expression refers to program of promoter and transcription. Radiation induces ATF 3 expression by activating the promoter and RNA transcription. In method of tetracycline-inducible system (tet-off), we have found that over-expression of ATF 3 protein brings caspase/PARP proteins into cleavage, which induces cell programmed death, and suppresses cell growth. Meanwhile, it was found that ATF 3 expression could slow down progression of cell from G 1 to S phase. It indicates ATF 3 protein might play a negative role in the control of cell cycle progression. It is very excited that expression of ATF 3 protein did not only suppress cell growth, but also demonstrated protecting effect of cell growth suppression resulting from ionizing radiation. It is suggested that ATF 3 protein might take part in the damage repair process of cells. (author)

  8. Comparison of gamma radiation - induced effects in two human prostate cancer cells

    International Nuclear Information System (INIS)

    Vucic, V.; Adzic, M.; Ruzdijic, S.; Radojcic, M.B. . E-mail address of corresponding author: vesnav@vin.bg.ac.yu; Vucic, V.)

    2005-01-01

    In this study, the effects of gamma radiation on two hormone refractory human prostate cancer cell lines, DU 145 and PC-3, were followed. It was shown that gamma radiation induced significant inhibition of cell proliferation and viability in dose dependent manner. Antiproliferative effects of radiation were similar in both cell lines, and more pronounced than cytotoxic effects. In addition to that, PC-3 cell line was more resistant to radiation -induced cytotoxicity. (author)

  9. A case of radiation-induced cancer of the hypopharynx

    International Nuclear Information System (INIS)

    Miyamoto, Kouji; Shimizu, Yukio; Yura, Jirou; Itoh, Yasufumi; Ikeda, Tsuneko; Outsubo, Toshio; Saitou, Hitoshi

    2001-01-01

    We report a case of radiation-induced cancer of the hypopharynx in a 65-year-old woman. The patient had received radiation treatment for Basedow's disease for several years starting at the age of 10 years. On June 26, 1993, she was examined at our hospital because of hoarseness and dysphagia. On July 22, right lobectomy was performed for suspected thyroid cancer. During this operation, endoscopy revealed hypopharyngeal cancer. Twenty-two days after surgery, total pharyngolaryngectomy and total esophagectomy were performed and a pharyngogastrostomy and a permanent tracheostomy were created. Histologic examination revealed moderately differentiated squamous cell cancer. This case was diagnosed as radiation-induced caner according to the diagnostic criteria of Sakai. (author)

  10. A case of radiation-induced cancer of the hypopharynx

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Kouji; Shimizu, Yukio; Yura, Jirou; Itoh, Yasufumi; Ikeda, Tsuneko [Matsunami General Hospital, Kasamatsu, Gifu (Japan); Outsubo, Toshio; Saitou, Hitoshi

    2001-06-01

    We report a case of radiation-induced cancer of the hypopharynx in a 65-year-old woman. The patient had received radiation treatment for Basedow's disease for several years starting at the age of 10 years. On June 26, 1993, she was examined at our hospital because of hoarseness and dysphagia. On July 22, right lobectomy was performed for suspected thyroid cancer. During this operation, endoscopy revealed hypopharyngeal cancer. Twenty-two days after surgery, total pharyngolaryngectomy and total esophagectomy were performed and a pharyngogastrostomy and a permanent tracheostomy were created. Histologic examination revealed moderately differentiated squamous cell cancer. This case was diagnosed as radiation-induced caner according to the diagnostic criteria of Sakai. (author)

  11. Occurrence and properties of antibodies against virus-associated transformation proteins in radiation-induced osteosarcomas in mice

    International Nuclear Information System (INIS)

    Hofherr, J.

    1983-01-01

    In this thesis it was looked if there is an immunresponse against such viral oncogene products in mice with radiation-induced osteosarcomas. Sera from mice with transplantable radiation-induced osteosacomas showed strong cytotoxicity against cells from a Moloney sarcoma virus-induced tumor and to a smaller extent also against FBJ osteosarcoma virus-transformed nonproducer cells. The cytotoxic activity was bound to the IgM fraction of the sera. Immunprecipitation of 35 S-methionine labelled virus- or radiation-transformed cells with cytotoxic sera showed on PAGE two proteins of molecular weights (m.w.) of about 50-55 kD. A protein of about 38 kD was expressed only in transformed cells whereas another protein of about 43 kD was seen in all cells except in uninfected muscle cells of adult mice. In order to further characterize the nature of these antigens immunprecipitates with unlabelled cells were tested in a protein kinase assay with gamma 32 P ATP and analysed on PAGE. Phosphorylation of proteins occured predominantly of more than 70 kD m.w., of about 68 kD, 50-55 kD and to a lesser extent also of about 32, 34 and 39 kD. The phosphorylation site of the proteins was at serine and threonine residues. These results indicate that mice with radiation-induced osteosarkomas develop antibodies against 'in vivo' and 'in vitro'-sarcoma virus transformed cells. (orig./MG) [de

  12. Radiation-Induced Bystander Response: Mechanism and Clinical Implications

    OpenAIRE

    Suzuki, Keiji; Yamashita, Shunichi

    2014-01-01

    Significance: Absorption of energy from ionizing radiation (IR) to the genetic material in the cell gives rise to damage to DNA in a dose-dependent manner. There are two types of DNA damage; by a high dose (causing acute or deterministic effects) and by a low dose (related to chronic or stochastic effects), both of which induce different health effects. Among radiation effects, acute cutaneous radiation syndrome results from cell killing as a consequence of high-dose exposure.

  13. Imaging Features that Discriminate between Foci Induced by High- and Low-LET Radiation in Human Fibroblasts

    International Nuclear Information System (INIS)

    Costes, Sylvain V.; Boissiere, Arnaud; Ravani, Shraddha; Romano, Raquel; Parvin, Bahram; Barcellos-Hoff, Mary Helen

    2006-01-01

    In this study, we investigated the formation of radiation-induced foci in normal human fibroblasts exposed to X rays or 130 keV/mum nitrogen ions using antibodies to phosphorylated protein kinase ataxia telangiectasia mutated (ATMp) and histone H2AX(gamma-H2AX). High-content automatic image analysis was used to quantify the immunofluorescence of radiation-induced foci. The size of radiation-induced foci increased for both proteins over a 2-h period after nitrogen-ion irradiation, while the size of radiation-induced foci did not change after exposure to low-LET radiation. The number of radiation-induced ATMp foci showed a more rapid rise and greater frequency after X-ray exposure and was resolved more rapidly such that the frequency of radiation-induced foci decreased by 90 percent compared to 60 percent after exposure to high-LET radiation 2 h after 30 cGy. In contrast, the kinetics of radiation-induced gamma-H2AX focus formation was similar for high- and low-LET radiation in that it reached a plateau early and remained constant for up to 2 h. High-resolution 3D images of radiation-induced gamma-H2AX foci and dosimetry computation suggest that multiple double-strand breaks from nitrogen ions are encompassed within large nuclear domains of 4.4 Mbp. Our work shows that the size and frequency of radiation-induced foci vary as a function of radiation quality, dose, time and protein target. Thus, even though double-strand breaks and radiation-induced foci are correlated, the dynamic nature of both contradicts their accepted equivalence for low doses of different radiation qualities

  14. MRI appearance of radiation-induced changes of normal cervical tissues

    International Nuclear Information System (INIS)

    Noemayr, A.; Lell, M.; Bautz, W.; Sweeney, R.; Lukas, P.

    2001-01-01

    Irradiation causes specific MRI changes in anatomic morphology and signal intensity. To avoid misinterpretation, it is important to consider the potential radiation changes of normal tissue in MRI. The aim of this study was to describe the detected radiation effects on normal cervical tissues in MRI. Pretreatment and posttreatment MRI of 52 patients with primary neck tumors were evaluated retrospectively. The MR imaging was performed before initiating radiotherapy and at the end of the treatment period. Patients underwent follow-up studies within 24 months after the end of irradiation. Edema was the main radiation-induced effect. It was detected in the epiglottis, larynx, pharynx wall, retro- and parapharyngeal space, salivary glands, muscles, and subcutaneous tissue. In some cases the bone marrow of the mandible showed edema, due to osteonecrosis. We additionally detected fluid accumulation in the mastoid cells. Radiation caused volume reduction of the parotid gland, thickening of the pharynx wall, and fatty degeneration of bone marrow. Magnetic resonance imaging is an excellent method of depicting radiation-induced changes of normal tissue. Especially T2-weighted sequences allow the detection of even slight edema. It is important to be aware of the most common radiation-induced changes in MRI and to take them into account when assessing an examination. (orig.)

  15. 3D ultrasound Nakagami imaging for radiation-induced vaginal fibrosis

    Science.gov (United States)

    Yang, Xiaofeng; Rossi, Peter; Shelton, Joseph; Bruner, Debrorah; Tridandapani, Srini; Liu, Tian

    2014-03-01

    Radiation-induced vaginal fibrosis is a debilitating side-effect affecting up to 80% of women receiving radiotherapy for their gynecological (GYN) malignancies. Despite the significant incidence and severity, little research has been conducted to identify the pathophysiologic changes of vaginal toxicity. In a previous study, we have demonstrated that ultrasound Nakagami shape and PDF parameters can be used to quantify radiation-induced vaginal toxicity. These Nakagami parameters are derived from the statistics of ultrasound backscattered signals to capture the physical properties (e.g., arrangement and distribution) of the biological tissues. In this paper, we propose to expand this Nakagami imaging concept from 2D to 3D to fully characterize radiation-induced changes to the vaginal wall within the radiation treatment field. A pilot study with 5 post-radiotherapy GYN patients was conducted using a clinical ultrasound scanner (6 MHz) with a mechanical stepper. A serial of 2D ultrasound images, with radio-frequency (RF) signals, were acquired at 1 mm step size. The 2D Nakagami shape and PDF parameters were calculated from the RF signal envelope with a sliding window, and then 3D Nakagami parameter images were generated from the parallel 2D images. This imaging method may be useful as we try to monitor radiation-induced vaginal injury, and address vaginal toxicities and sexual dysfunction in women after radiotherapy for GYN malignancies.

  16. Radiation induced structural changes in alpha-copper-zinc alloys

    International Nuclear Information System (INIS)

    Schuele, W.; Gieb, M.

    1991-01-01

    During irradiation of alpha-copper-zinc alloys with high energy electrons and protons a decrease of the electrical resistivity due to an increase of the degree of short range order is observed through radiation enhanced diffusion followed by an increase of the electrical resistivity through the formation of radiation induced interstitial clusters. The initial formation rate of interstitial clusters increases about linearly with the displacement rate for electron and proton irradiation. The largest initial formation rate is found between 60 and 130 0 C becoming negligibly small above 158 0 C and decreases drastically below 60 0 C. The dynamic steady state interstitial cluster concentration increases with decreasing irradiation temperature in the investigated temperature range between 158 and 40 0 C. Above 158 0 C the formation rate of interstitial clusters is negligibly small. Thus the transition temperature for radiation induced interstitial cluster formation is 158 0 C, depending mainly on the migration activation energy of vacancies. The radiation induced interstitial clusters are precipitates in those alloys in which the diffusion rate of the undersized component atoms via an interstitialcy diffusion mechanism is larger than that of the other atoms

  17. Reduction of radiation injury of fresh agricultural products by saccharide

    International Nuclear Information System (INIS)

    Todoroki, Setsuko; Hayashi, Toru

    1999-01-01

    Radiation exposure has been paid attention as an alternative technique of methylbromide to protect agricultural products against insects. However, it has been pointed out that radiation at a dose lower than 300-400 Gy necessary for insecticidal effects might produce damages in fresh agricultural products. To reduce such radiation damages, radiation sensitivities of various fresh products were determined to clarify whether sugar treatment is effective for reduction of damages. Further, the timing of the treatment and its influence on the metabolism of agricultural product were investigated. When sucrose was added to a cut flower of chrysanthemum via water before and during irradiation, the withering time of its leaves and flowers was earlier than that of the untreated product, whereas continuous administration of sucrose after radiation exposure caused to lengthen the flower's life and delay the leave's yellowing. Thus, it was indicated that continuous sugar supply after irradiation was effective for prevention of radiation damages. (M.N.)

  18. 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.)

  19. 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.)

  20. Radiation-Induced Breast Cancer Incidence and Mortality From Digital Mammography Screening: A Modeling Study.

    Science.gov (United States)

    Miglioretti, Diana L; Lange, Jane; van den Broek, Jeroen J; Lee, Christoph I; van Ravesteyn, Nicolien T; Ritley, Dominique; Kerlikowske, Karla; Fenton, Joshua J; Melnikow, Joy; de Koning, Harry J; Hubbard, Rebecca A

    2016-02-16

    Estimates of risk for radiation-induced breast cancer from mammography screening have not considered variation in dose exposure or diagnostic work-up after abnormal screening results. To estimate distributions of radiation-induced breast cancer incidence and mortality from digital mammography screening while considering exposure from screening and diagnostic mammography and dose variation among women. 2 simulation-modeling approaches. U.S. population. Women aged 40 to 74 years. Annual or biennial digital mammography screening from age 40, 45, or 50 years until age 74 years. Lifetime breast cancer deaths averted (benefits) and radiation-induced breast cancer incidence and mortality (harms) per 100,000 women screened. Annual screening of 100,000 women aged 40 to 74 years was projected to induce 125 breast cancer cases (95% CI, 88 to 178) leading to 16 deaths (CI, 11 to 23), relative to 968 breast cancer deaths averted by early detection from screening. Women exposed at the 95th percentile were projected to develop 246 cases of radiation-induced breast cancer leading to 32 deaths per 100,000 women. Women with large breasts requiring extra views for complete examination (8% of population) were projected to have greater radiation-induced breast cancer risk (266 cancer cases and 35 deaths per 100,000 women) than other women (113 cancer cases and 15 deaths per 100,000 women). Biennial screening starting at age 50 years reduced risk for radiation-induced cancer 5-fold. Life-years lost from radiation-induced breast cancer could not be estimated. Radiation-induced breast cancer incidence and mortality from digital mammography screening are affected by dose variability from screening, resultant diagnostic work-up, initiation age, and screening frequency. Women with large breasts may have a greater risk for radiation-induced breast cancer. Agency for Healthcare Research and Quality, U.S. Preventive Services Task Force, National Cancer Institute.

  1. Molecular analysis of radiation-induced experimental tumors in mice

    International Nuclear Information System (INIS)

    Niwa, O.; Muto, M.; Suzuki, F.

    1992-01-01

    Molecular analysis was made on mouse tumors induced by radiation and chemicals. Expression of oncogenes was studied in 12 types of 178 mouse tumors. Southern blotting was done on tumors in which overexpression of oncogenes was noted. Amplification of the myc oncogene was found in chemically induced sarcomas, but not those induced by radiations. Radiogenic thymomas were studied in detail. These thymomas were induced in two different ways. The first was thymomas induced by direct irradiation of F1 mice between C57BL/6NxC3H/He. Southern analysis of DNA revealed deletion of specific minisatellite bands in these tumors. DNA from directly induced thymomas induced focus formation when transfected into normal Golden hamster cells. The mouse K-ras oncogene was detected in these transformants. The second type of thymomas was induced by X-irradiation of thymectomized B10.thy1.2 mice in which normal thymus from congenic B10,thy1.1. mice was grafted. Thymomas of the donor origin was analysed by transfection and the transformants by DNA from those indirectly induced thymomas did not contain activated ras oncogenes. (author)

  2. Mutations induced by X-rays and UV radiation during the nuclear cycle in the yeast Schizosarccharomyces pombe

    International Nuclear Information System (INIS)

    Barale, R.; Rusciano, D.; Loprieno, N.

    1982-01-01

    The availability of a cell-division-cycle (cdc) mutant in the fission yeast S. pombe, wee 1-50, has made possible the production of a large population of G 1 nuclear-stage synchronized cells. During their development, yeast cells from the G 1 into the G 2 nuclear stages were treated with X-rays and UV radiation at various doses. The DNA pre-replicative and replicative phases were the most sensitive to both cell lethality and mutant induction with either X-rays or UV radiation. The trends of induced biological effects that were observed suggest that the induction of mutations is dependent on the number of unrepaired DNA lesions that reach the replicating fork or of those that occur at that time. The X-ray-induced mutations were earlier saturated, possibly because of the higher number of lethal lesions so induced. (orig.)

  3. 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

  4. Radiation hygiene of animal production in normal and emergency situations

    International Nuclear Information System (INIS)

    Stajicj, J.; Petrovicj, B.; Draganovicj, B.

    1977-01-01

    Radiation hazards imposed by contemporary development and peaceful and military uses of nuclear energy have implied the introduction of radiational control in animal production, and radiation-hygienic expertize of animal products and animal foodstuffs. Various treatments in scientific research, education and uses of relevant equipment, undertaken in right time, enabled our Veterinary services to start successfully to solve problems of radiation control and protection of animal production in normal and emergency situations. An important role in this context has the Section of Radiation Hygiene Yugoslav Veterinary Association, as an initiator of many activities that are intended to affirme Radiation Hygiene in the domain of scientific research and in the field of national defence and self-protection

  5. The process and promotion of radiation-induced cell death

    International Nuclear Information System (INIS)

    Sasaki, Hiroshi

    1998-01-01

    Radiation-induced cell death is divided into reproductive and interphase death, whose process can be revealed by time-lapse observations. Pedigree analyses of progenies derived from a surviving progenitor cell have shown that moribund cells appear in clusters among cells which are apparently undamaged (lethal sectoring). Sister cell fusion, which likely results from chromosome bridge, is the most frequently observed cell abnormality leading to reproductive death. While interphase death does not occur unless the dose exceeds 10 Gy for low LET radiation such as X-rays, high-LET radiation is very effective at inducing interphase death (RBE: ≅3 at 230 keV/μm). Expression or fixation of potentially lethal damage (PLD) is closely associated with cell cycle events and enhanced by inducing premature chromosome condensation (PCC) at a nonpermissive temperature in tsBN2 cells with a ts-defect in RCC1 protein (a regulator of chromatin condensation) which monitors the completion of DNA replication. Furthermore, higher-order structural changes in nuclear matrix such as induced by leptomycin B, an inhibitor of CRM1 (chromosome region maintenance) protein, also play an important role in the fixation of PLD. (author)

  6. A juvenile case of radiation-induced meningioma two years after radiation for craniopharyngioma

    International Nuclear Information System (INIS)

    Kano, Tomoaki; Zama, Akira; Ono, Nobuo; Nakamura, Tadashi; Tamura, Masaru; Ohe, Tihiro; Nakazato, Yoichi

    1994-01-01

    The patient was a 7-years-old boy who received radiation therapy of 50 Gy after total gross removal of a craniopharyngioma. After two years a follow up CT scan showed a new enhanced lesion in the right temporal tip within the previous irradiation field. Total removal of the tumor was performed and its histological examination showed it to be an atypical meningioma. This atypical meningioma satisfied Cahan's criteria. So we diagnosed this atypical meningioma as radiation-induced meningioma. Immunohistochemically this meningioma stained for Vimentin. An electron microscopical examination showed neither desmosome nor interdigitation. The score of Ki-67 and BrdU-L. I was very small. Compared with previously reported juvenile radiation-induced meningioma, the latency was very short. The patient received growth hormone (GH) replacement therapy. We suspected relation between GH replacement therapy and short latency. He was discharged without any new neurological deficits and we haven't detected tumor recurrence for two years. (author)

  7. A juvenile case of radiation-induced meningioma two years after radiation for craniopharyngioma

    Energy Technology Data Exchange (ETDEWEB)

    Kano, Tomoaki; Zama, Akira; Ono, Nobuo; Nakamura, Tadashi; Tamura, Masaru; Ohe, Tihiro; Nakazato, Yoichi (Gunma Univ., Maebashi (Japan). School of Medicine)

    1994-04-01

    The patient was a 7-years-old boy who received radiation therapy of 50 Gy after total gross removal of a craniopharyngioma. After two years a follow up CT scan showed a new enhanced lesion in the right temporal tip within the previous irradiation field. Total removal of the tumor was performed and its histological examination showed it to be an atypical meningioma. This atypical meningioma satisfied Cahan's criteria. So we diagnosed this atypical meningioma as radiation-induced meningioma. Immunohistochemically this meningioma stained for Vimentin. An electron microscopical examination showed neither desmosome nor interdigitation. The score of Ki-67 and BrdU-L. I was very small. Compared with previously reported juvenile radiation-induced meningioma, the latency was very short. The patient received growth hormone (GH) replacement therapy. We suspected relation between GH replacement therapy and short latency. He was discharged without any new neurological deficits and we haven't detected tumor recurrence for two years. (author).

  8. Estimated population exposure from nuclear power production and other radiation sources

    International Nuclear Information System (INIS)

    Pochin, E.E.

    1976-01-01

    Estimates are given of the total radiation dose from all forms of ionizing radiation resulting from nuclear power reduction. A power consumption of 1kW per head of population, derived entirely from nuclear energy, would increase the average radiation exposure of the whole population from 100mrem per year from natural sources (plus about 40mrem per year from medical procedures and other artificial causes) by about 6mrem per year. The genetically signifificant component of this increase would be about 4mrem per year. Available estimates of harm from radiation would indicate that this would give a risk per year per million of population of about 1 fatal induced malignancy, about the same number of malignancies fully treatable by operation, and, after many generations, about the same number of inherited defects, of greater or less severity, per year. Accidental injuries, particularly in constructional and mining work, would cause an estimated 1 fatality and 50 other accidents annually. Indications are given of the number of fatalities and accidents involved in equal power production by alternative methods, and of the value and limitations of such numerical comparisons in reaching decisions on the development of future power programmes

  9. Treatment of Radiation Induced Biological Changes by Bone Marrow Transplantation

    International Nuclear Information System (INIS)

    El-Missiry, M.A.; Shehata, G.; Roushdy, H.M; Fayed, Th.A.

    1999-01-01

    Preventing the propagation of radiation induced oxidative damage has been a subject of considerable investigations. The ultimate goal of the present study is to use bone marrow cells to ameliorate or to treat the radiation sickness. Transplantation of bone marrow cell has shown promising results in the present experimental radiation treatment. In this report, suspension of bone marrow cells was injected into rats 12 h. after exposure to 4.5 Gy whole body gamma irradiation. Significant results were recorded on the successful control of the radiation induced disorders in a number of biochemical parameters including certain enzymatic and nonenzymatic antioxidants (superoxide dismutase and glutathione) and certain parameters related to kidney function including creatinine, urea as well as Atpase Activity in blood serum, urine and kidney tissue

  10. Evaluation of edaravone against radiation-induced oral mucositis in mice

    Directory of Open Access Journals (Sweden)

    Noriko Nakajima

    2015-03-01

    Full Text Available Oral mucositis induced by radiotherapy for cancers of the head and neck reduce the quality of life of patients. However, effective therapeutic agents are lacking. Symptomatic treatment involves local anesthesia and analgesia. We focused on the antioxidant effects of edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one; Radicut®. Oral mucositis was induced on the tongue tips of mice using a single dose of X-rays (20 Gy. To evaluate the protective effect of edaravone (30 and 300 mg/kg, administration was carried out 30 min before irradiation. Survival, oral mucositis score, myeloperoxidase activity, and levels of 2-Thiobarbituric acid reactive substances were measured, and all were improved compared with those of control mice. A significant difference was not found in terms of survival due to edaravone. Histopathologic findings also highlighted the beneficial features of edaravone. Edaravone reduced the production of reactive oxygen species. These findings suggest that the protective effect of edaravone against radiation-induced oral mucositis is through an antioxidant effect.

  11. Effect of UV-C radiation on bioactive compounds of pineapple (Ananas comosus L. Merr.) by-products.

    Science.gov (United States)

    Freitas, Ana; Moldão-Martins, Margarida; Costa, Helena S; Albuquerque, Tânia G; Valente, Ana; Sanches-Silva, Ana

    2015-01-01

    The industrial processing of pineapple generates a high quantity of by-products. To reduce the environmental impact of these by-products and the inherent cost of their treatment, it is important to characterise and valorise these products, converting them into high added value products. Ultra-violet radiation is one of the main sustainable sanitation techniques for fruits. Since this radiation can induce plant stress which can promote the biosynthesis of bioactive compounds, it is important to evaluate its effect in fruits. The amounts of vitamins (C and E) and carotenoids (α-carotene, β-carotene, β-cryptoxanthin, lutein, lycopene, neoxanthin, violaxanthin and zeaxanthin) in pineapple by-products (core and rind) were analysed before and after treatment with UV radiation. All treated and untreated pineapple by-products contained β-carotene as the main carotenoid (rind, 2537-3225 µg; and core, 960-994 µg 100 g(-1) DW). Pineapple rind also contained lutein (288-297 µg 100 g(-1) DW) and α-carotene (89-126 µg 100 g(-1) DW). The results provide evidence of the potential of pineapple by-products as a source of bioactive compounds with antioxidant activity, which can be used by pharmaceutical, cosmetics and food industries. In addition, UV-C was shown to be a treatment that can add nutritional value to pineapple by-products. © 2014 Society of Chemical Industry.

  12. Caffeine Markedly Enhanced Radiation-Induced Bystander Effects

    International Nuclear Information System (INIS)

    Jiang Erkang; Wu Lijun

    2009-01-01

    In this paper it is shown that incubation with 2 mM caffeine enhanced significantly the MN (micronucleus) formation in both the 1 cGy α-particle irradiated and non-irradiated bystander regions. Moreover, caffeine treatment made the non-irradiated bystander cells more sensitive to damage signals. Treated by c-PTIO(2-(4-carboxy-phenyl)- 4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide), a nitric oxide (NO) scavenger, the MN frequencies were effectively inhibited, showing that nitric oxide might be very important in mediating the enhanced damage. These results indicated that caffeine enhanced the low dose α-particle radiation-induced damage in irradiated and non-irradiated bystander regions, and therefore it is important to investigate the relationship between the radiosensitizer and radiation-induced bystander effects (RIBE). (ion beam bioengineering)

  13. Non-radiation induced signals in TL dosimetry

    International Nuclear Information System (INIS)

    German, U.; Weinstein, M.

    2002-01-01

    One source of background signals, which are non-radiation related, is the reader system and it includes dark current, external contaminants and electronic spikes. These factors can induce signals equivalent to several hundredths of mSv. Mostly, the effects are minimised by proper design of the TLD reader, but some effects are dependent on proper operation of the system. The other main group of background signals originate in the TL crystal and is due to tribothermoluminescence, dirt, chemical reactions and stimulation by visible or UV light. These factors can have a significant contribution, equivalent to over several mSv, depending on whether the crystal is bare or protected by PTFE. Working in clean environments, monitoring continuously the glow curve and performing glow curve deconvolution are suggested to minimise non-radiation induced spurious signals. (author)

  14. Radiation-induced transmission spectral variations of Ce3+-doped heavy germanate glasses

    International Nuclear Information System (INIS)

    Yang Yunxia; Baccaro, S.; Cecilia, A.; Rao Jinhua; Zhang Junbiao; Xia Fang; Chen Guorong

    2005-01-01

    Radiation-induced transmission spectral variations of Ce 3+ -doped heavy germanate glasses used as scintillating materials are presented. Glass matrix contains mainly GeO 2 , BaO and Gd 2 O 3 with a density higher than 5 g/cm 3 . Glasses are melted in the different atmosphere. The transmission spectra of glasses before and after radiation treatments are measured and compared. Unlike exhibiting the monotonous deterioration effect on the glass matrix, radiation plays the radiation protection role, even making enhanced transmission of Ce 3+ -doped glasses, depending upon glass melting atmosphere and radiation dose. Radiation-induced reducing and oxidizing mechanism is proposed to explain phenomena

  15. Investigation of radiation-induced multilayered signalling response of the inflammatory pathway

    International Nuclear Information System (INIS)

    Babini, G.; Ugolini, M.; Morini, J.; Baiocco, G.; Ottolenghi, A.; Mariotti, L.; Tabarelli de Fatis, P.; Liotta, M.

    2015-01-01

    Ionising radiation exposure of cells might induce the perturbation of cell functions and, in particular, the activation or inhibition of several important pathways. This perturbation can cause the deregulation of both intra- and extra-cellular signalling cascades (such as the inflammatory pathway) and alter not only the behaviour of directly exposed cells but also the neighbouring nonirradiated ones, through the so-called bystander effect. The aim of the present work was to investigate the complex nonlinear interactions between the inflammatory pathway and other strictly interlaced signalling pathways, such as Erk1/2 and Akt/PKB, focusing on the radiation-induced perturbation of such pathways in the dose range of 0 -2 Gy. The results show how radiation affects these interconnected pathways and how confounding factors, such as the change of culture medium, can hide radiation-induced perturbations. (authors)

  16. Effects of ongoing smoking on the development of radiation-induced pneumonitis in breast cancer and oesophagus cancer patients

    International Nuclear Information System (INIS)

    Johansson, S.; Franzen, L.; Henriksson, R.; Bjermer, L.

    1998-01-01

    Purpose: To investigate the influence of smoking on the development of radiation-induced pneumonitis in patients treated for breast and oesophagus cancer. Materials and methods: This is a retrospective study on 405 females diagnosed with primary unilateral breast cancer stages 1 and 2 and 201 oesophagus carcinoma patients. The possibilities in Sweden to obtain detailed information from different medical records were used to collect data on smoking habits, radiation treatment and spontaneously reported pneumonitis. Radiation-induced pneumonitis was defined as a combination of roentgenographic infiltrate in the lung field involving an irradiated area on the chest X-ray and clinical symptoms such as non-productive cough and dyspnoea. Results: Six breast cancer patients had spontaneously reported pneumonitis. Five of them were non-smokers (P=0.182) and the other was a former smoker. Eight of the oesophagus cancer patients had spontaneously reported radiation-induced clinical pneumonitis and they were all non-smokers (P=0.022), except one, who was a pipe smoker. None of the patients who were cigarette smokers were recorded as developing clinical pneumonitis after irradiation. Conclusion: These data could support the previous clinical observations and experimental studies that smoking depresses the frequency of radiation-induced pneumonitis. The present study as well as earlier observations could justify further studies concerning the possibility of an interaction of smoking with cancer treatment, both from the view of therapeutic failures and reduced adverse effects. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  17. Radiation protection programme for a radioisotope production facility

    International Nuclear Information System (INIS)

    Makgato, Thutu Nelson

    2015-02-01

    The present project reviews reactor based radioisotope production facilities. An overview of techniques and methodologies used as well as laboratory facilities necessary for the production process are discussed. Specific details of reactor based production and processing of more commonly used industrial and pharmaceutical radioisotopes are provided. Ultimately, based on facilities and techniques utilized as well as the associated hazard assessment, a proposed radiation protection programme is discussed. Elements of the radiation protection programme will also consider lessons from recent incidents and accidents encountered in radioisotope production facilities. (au)

  18. Influence of radiation-induced apoptosis on development brain in molecular regulation

    International Nuclear Information System (INIS)

    Gu Guixiong

    2000-01-01

    An outline of current status on the influence of radiation on the development brain was given. Some genes as immediate early gene, Bcl-2 family, p53, heat shock protein and AT gene play an important regulation role in ionizing radiation-induced development brain cells apoptosis. And such biological factor as nerve growth factor, interleukin-1, tumor necrosis factor, basic fibroblast growth factor, transforming growth factor and so on have a vital protection function against ionizing radiation-induced cells apoptosis

  19. Radiation-induced reactions in polydimethyl siloxanes

    International Nuclear Information System (INIS)

    Menhofer, H.

    1988-01-01

    The dissertation reports an investigation into the behaviour of polydimethyl soloxanes (PDMS) subject to the radiation field of a 60 Co-γ radiation source at different irradiation conditions. Several different analytical methods have been applied for the detection of chemical changes in the material and their effects on the polymeric segment mobility. Application of the ESR-spintrap technique identifies the primary radicals x CH 3 , -Si x , and -Si-CH 2 x , induced by the radiolysis of the PDMS. The individual rates of radical formation have been found to be strongly dependent on temperature. (orig./LU) [de

  20. [Seasonal changes in tumor necrosis factor production in hibernating animals in normal conditions and under the effects of electromagnetic and ionizing radiation].

    Science.gov (United States)

    Ogaĭ, V B; Novoselova, E G; Makar, V R; Kolaeva, S G

    2002-01-01

    Production of tumor necrosis factor (TNF) has been investigated in peritoneal macrophages and splenic T cells of Arctic Yakutian ground squirrel (Citellus Undulatus Pallas) upon in vitro action of electromagnetic and ionizing radiation during annual cycle. The significant activation of TNF production in the cells of awaken ground squirrels in winter and increasing level of the lymphokine production at spring-summer period has been indicated. The level of TNF production in splenic T cells was not changed during whole year. The electromagnetic radiation (EMR) of low intensity (8.15-18 GHz, 1 microW/cm2) induced an augmentation of both secretory and proliferative activity in TNF-producing cells. Ionizing radiation suppressed T cell proliferation, but the doses 2 and 5 Gy resulted in a significant stimulation of TNF production in T cells and macrophages.

  1. 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

  2. Thioredoxin mitigates radiation-induced hematopoietic stem cell injury in mice

    Directory of Open Access Journals (Sweden)

    Pasupathi Sundaramoorthy

    2017-11-01

    Full Text Available Abstract Background Radiation exposure poses a significant threat to public health. Hematopoietic injury is one of the major manifestations of acute radiation sickness. Protection and/or mitigation of hematopoietic stem cells (HSCs from radiation injury is an important goal in the development of medical countermeasure agents (MCM. We recently identified thioredoxin (TXN as a novel molecule that has marked protective and proliferative effects on HSCs. In the current study, we investigated the effectiveness of TXN in rescuing mice from a lethal dose of total body radiation (TBI and in enhancing hematopoietic reconstitution following a lethal dose of irradiation. Methods We used in-vivo and in-vitro methods to understand the biological and molecular mechanisms of TXN on radiation mitigation. BABL/c mice were used for the survival study and a flow cytometer was used to quantify the HSC population and cell senescence. A hematology analyzer was used for the peripheral blood cell count, including white blood cells (WBCs, red blood cells (RBCs, hemoglobin, and platelets. Colony forming unit (CFU assay was used to study the colongenic function of HSCs. Hematoxylin and eosin staining was used to determine the bone marrow cellularity. Senescence-associated β-galactosidase assay was used for cell senescence. Western blot analysis was used to evaluate the DNA damage and senescence protein expression. Immunofluorescence staining was used to measure the expression of γ-H2AX foci for DNA damage. Results We found that administration of TXN 24 h following irradiation significantly mitigates BALB/c mice from TBI-induced death: 70% of TXN-treated mice survived, whereas only 25% of saline-treated mice survived. TXN administration led to enhanced recovery of peripheral blood cell counts, bone marrow cellularity, and HSC population as measured by c-Kit+Sca-1+Lin– (KSL cells, SLAM + KSL cells and CFUs. TXN treatment reduced cell senescence and radiation-induced

  3. Application of radiation induced in vitro mutagenesis for the improvement of sugarcane

    International Nuclear Information System (INIS)

    Penna, Suprasanna; Patade, Vikas Y.; Vaidya, E.R.; Patil, V.D.

    2009-01-01

    Sugarcane varieties with improved tolerance to adverse environmental conditions are highly desirable, as unfavourable environmental factors are the major contributors that can reduce average productivity by 65% to 87%. In this study, we have employed in vitro cultures and radiation induced mutagenesis in three commercially used cultivars. Irradiated callus cultures were also selected for salt tolerance, and radiosensitivity in terms of growth rate and cell viability indicated stress effects. Several mutants with agronomically desirable traits have been isolated that are in field evaluation. (author)

  4. Search for the lowest irradiation dose from literatures on radiation-induced breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yoshizawa, Y; Kusama, T [Tokyo Univ. (Japan). Faculty of Medicine

    1975-12-01

    A survey of past case reports concerning radiation-induced breast cancer was carried out in order to find the lowest irradiation dose. The search of literature published since 1951 revealed 10 cases of radiation-induced breast cancer. Only 5 cases had precise descriptions of the irradiation dose. The lowest irradiation dose was estimated at 1470 rads in the case of external X-ray irradiation for tuberous angioma. All of cases of radiation-induced breast cancer had received radiation for the treatment of nonmalignant tumors, such as pulmonary tuberculosis, mastitis, and tuberous angioma. There also were three statistical studies. The first concerned atomic bomb survivors, the second, pulmoanry tuberculous patients subjected to frequent fluoroscopies, and the third, patients of acute post partum mastitis. These statistical studies had revealed a significant increase in the incidence of breast cancer in the irradiated group, but there was little information about the lowest irradiation dose. It was noticed that radiation-induced breast cancer was more numerous in the upper inner quadrant of the breast. Most histopathological findings of radiation-induced breast cancer involved duct cell carcinoma. The latent period was about 15 years.

  5. Visual sensations induced by Cherenkov radiation

    International Nuclear Information System (INIS)

    McNulty, P.J.; Pease, V.P.; Bond, V.P.

    1975-01-01

    Pulses of relativistic singly charged particles entering the eyeball induce a variety of visual phenomena by means of Cerenkov radiation generated during their passage through the vitreous. These phenomena are similar in appearance to many of the visual sensations experienced by Apollo astronauts exposed to the cosmic rays in deep space

  6. Challenges in Clinical Management of Radiation-Induced Illnesses in Exploration Spaceflight

    Science.gov (United States)

    Blue, Rebecca; Chancellor, Jeffery; Suresh, Rahul; Carnell, Lisa; Reyes, David; Nowadly, Craig; Antonsen, Erik

    2018-01-01

    Historical solar particle events (SPEs) provide context for some understanding of acute radiation exposure risk to astronauts traveling outside of low Earth orbit. Modeling of potential doses delivered to exploration crewmembers anticipates limited radiation-induced health impacts, including prodromal symptoms of nausea, emesis, and fatigue, but suggests that more severe clinical manifestations are unlikely. Recent large animal-model research in space-analogs closely mimicking SPEs has identified coagulopathic events independent of the hematopoietic sequelae of higher radiation doses, similar in manifestation to disseminated intravascular coagulation (DIC). We explored the challenges of clinical management of radiation-related clinical manifestations, using currently accepted modeling techniques and anticipated physiological sequelae, to identify medical capabilities needed to successfully manage SPE-induced radiation illnesses during exploration spaceflight.

  7. Radiation-induced mitotic and meiotic aneuploidy in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Parry, J M; Sharp, D; Tippins, R S; Parry, E M

    1979-06-01

    A number of genetic systems are described which in yeast may be used to monitor the induction of chromosome aneuploidy during both mitotic and meiotic cell division. Using these systems we have been able to demonstrate the induction of both monosomic and trisomic cells in mitotically dividing cells and disomic spores in meiotically dividing cells after both UV light and X-ray exposure. The frequency of UV-light-induced monosomic colonies were reduced by post-treatment with photoreactivity light and both UV-light- and X-ray-induced monosomic colonies were reduced by liquid holding post-treatment under non-nutrient conditions. Both responses indicate an involvement of DNA-repair mechanisms in the removal of lesions which may lead to monosomy in yeast. This was further confirmed by the response of an excision-defective yeast strain which showed considerably increased sensitivity to the induction of monosomic colonies by UV-light treatment at low doses. Yeast cultures irradiated at different stages of growth showed variation in their responses to both UV-light and X-rays, cells at the exponential phase of growth show maximum sensitivity to the induction of monosomic colonies at low doses whereas stationary phase cultures showed maximum induction of monosomic colonies at high does. The frequencies of X-ray-induced chromosome aneuploidy during meiosis leading to the production of disomic spores was shown to be dependent upon the stage of meiosis at which the yeast cells were exposed to radiation. Cells which had proceeded beyond the DNA synthetic stage of meiosis were shown to produce disomic spores at considerably lower radiation doses than those cells which had only recently been inoculated into sporulation medium. The results obtained suggest that the yeast sustem may be suitable for the study of sensitivities of the various stages of meiotic cell division to the induction of chromosome aneuploidy after radiation exposure.

  8. Radiation-induced optic neuropathy: A magnetic resonance imaging study

    International Nuclear Information System (INIS)

    Guy, J.; Mancuso, A.; Beck, R.; Moster, M.L.; Sedwick, L.A.; Quisling, R.G.; Rhoton, A.L. Jr.; Protzko, E.E.; Schiffman, J.

    1991-01-01

    Optic neuropathy induced by radiation is an infrequent cause of delayed visual loss that may at times be difficult to differentiate from compression of the visual pathways by recurrent neoplasm. The authors describe six patients with this disorder who experienced loss of vision 6 to 36 months after neurological surgery and radiation therapy. Of the six patients in the series, two had a pituitary adenoma and one each had a metastatic melanoma, multiple myeloma, craniopharyngioma, and lymphoepithelioma. Visual acuity in the affected eyes ranged from 20/25 to no light perception. Magnetic resonance (MR) imaging showed sellar and parasellar recurrence of both pituitary adenomas, but the intrinsic lesions of the optic nerves and optic chiasm induced by radiation were enhanced after gadolinium-diethylenetriaminepenta-acetic acid (DTPA) administration and were clearly distinguishable from the suprasellar compression of tumor. Repeated MR imaging showed spontaneous resolution of gadolinium-DTPA enhancement of the optic nerve in a patient who was initially suspected of harboring recurrence of a metastatic malignant melanoma as the cause of visual loss. The authors found the presumptive diagnosis of radiation-induced optic neuropathy facilitated by MR imaging with gadolinium-DTPA. This neuro-imaging procedure may help avert exploratory surgery in some patients with recurrent neoplasm in whom the etiology of visual loss is uncertain

  9. Factors that modify risks of radiation-induced cancer

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1988-11-01

    The collective influence of biologic and physical factors that modify risks of radiation-induced cancer introduces uncertainties sufficient to deny precision of estimates of human cancer risk that can be calculated for low-dose radiation in exposed populations. The important biologic characteristics include the tissue sites and cell types, baseline cancer incidence, minimum latent period, time-to-tumor recognition, and the influence of individual host (age and sex) and competing etiologic influences. Physical factors include radiation dose, dose rate, and radiation quality. Statistical factors include time-response projection models, risk coefficients, and dose-response relationships. Other modifying factors include other carcinogens, and other biological sources (hormonal status, immune status, hereditary factors)

  10. Radiation-induced creep and swelling

    International Nuclear Information System (INIS)

    Heald, P.T.

    1977-01-01

    The physical basis for radiation induced creep and swelling is reviewed. The interactions between the point defects and dislocations are recalled since these interactions are ultimately responsible for the observable deformation phenomena. Both the size misfit interaction and the induced inhomogeneity interaction are considered since the former gives rise to irradiation swelling while the latter, which depends on both internal and external stresses, results in irradiation creep. The defect kinetics leading to the deformation processes are discussed in terms of chemical rate theory. The rate equations for the spatially averaged interstitial and vacancy concentrations are expressed in terms of the microstructural sink strengths and the solution of these equations leads to general expressions for the deformation rates

  11. Modulation of radiation-induced apoptosis and G2/M block in murine T-lymphoma cells

    International Nuclear Information System (INIS)

    Palayoor, S.T.; Macklis, R.M.; Bump, E.A.; Coleman, C.N.

    1995-01-01

    Radiation-induced apoptosis in lymphocyte-derived cell lines is characterized by endonucleolytic cleavage of cellular DNA within hours after radiation exposure. We have studied this phenomenon qualitatively (DNA gel electrophoresis) and quantitatively (diphenylamine reagent assay) in murine EL4 T-lymphoma cells exposed to 137 Cs γ irradiation. Fragmentation was discernible within 18-24 h after exposure. It increased with time and dose and reached a plateau after 8 Gy of γ radiation. We studied the effect of several pharmacological agents on the radiation-induced G 2 /M block and DNA fragmentation. The agents which reduced the radiation-induced G 2 /M-phase arrest (caffeine, theobromine, theophylline and 2-aminopurine) enhanced the degree of DNA fragmentation at 24 h. In contrast, the agents which sustained the radiation-induced G 2 /M-phase arrest (TPA, DBcAMP, IBMX and 3-aminobenzamide) inhibited the DNA fragmentation at 24 h. These studies on EL4 lymphoma cells are consistent with the hypothesis that cells with radiation-induced genetic damage are eliminated by apoptosis subsequent to a G 2 /M block. Furthermore, it may be possible to modulate the process of radiation-induced apoptosis in lymphoma cells with pharmacological agents that modify the radiation-induced G 2 /M block, and to use this effect in the treatment of patients with malignant disease. 59 refs., 7 figs

  12. Radiation-induced relief of pain in an animal model with bone invasion from cancer

    International Nuclear Information System (INIS)

    Seong, J.; Kim, J.; Kim, K.H.; Kim, U.J.; Lee, B.W.

    2003-01-01

    In clinic, local radiation is effective for relief of pain from cancer invasion into the bones. This effect is usually observed before the regression of tumor occurs, which implies radiation-induced pain relief by mechanisms other than tumor irradication. In this study, possible mechanisms were explored in animal model system. To establish an animal model, syngeneic hepatocarcinoma, HCa-I was transplanted on femoral periosteum of C3H/HeJ male mice and bone-invasive tumor growth was identified through the histological analysis. Development of tumor-induced pain was assessed by von Frey filament test, acetone test, and radiant heat test. Animals were also irradiated for their tumors. Any change in pain was analyzed by above tests for the quantitative change and by immunohistochemical stain for the expression of molecules such as c-fos, substance P, and calcitonin gene-related peptide (CGRP) in lumbar spinal cord. Cancer invasion into the bone was started from 7th day after transplantation and became evident at day 14. Objective increase of pain in the ipsilateral thigh was observed at day 14 on von Frey filament test and acetone test, while there was no remarkable regression of the tumors. In this model system, local radiation of tumor resulted in decrease in objective pain on von Frey filament test and acetone test. In the immunohistochemical stain for lumbar spinal cord, the expression of substance P and CGRP but not c-fos increased in tumor-bearing animal compared to the control. The expression of these molecules decreased in animals given local radiation. In summary, an animal model system was established for objective pain from cancer invasion into the bones. Local radiation of tumor induced objective pain relief and this effect seems to be mediated not by tumor regression but through altered production of pain-related molecules

  13. Radiation-induced relief of pain in an animal model with bone invasion from cancer

    Energy Technology Data Exchange (ETDEWEB)

    Seong, J; Kim, J; Kim, K H; Kim, U J; Lee, B W [Yonsei University Medical College, (Korea, Republic of)

    2003-07-01

    In clinic, local radiation is effective for relief of pain from cancer invasion into the bones. This effect is usually observed before the regression of tumor occurs, which implies radiation-induced pain relief by mechanisms other than tumor irradication. In this study, possible mechanisms were explored in animal model system. To establish an animal model, syngeneic hepatocarcinoma, HCa-I was transplanted on femoral periosteum of C3H/HeJ male mice and bone-invasive tumor growth was identified through the histological analysis. Development of tumor-induced pain was assessed by von Frey filament test, acetone test, and radiant heat test. Animals were also irradiated for their tumors. Any change in pain was analyzed by above tests for the quantitative change and by immunohistochemical stain for the expression of molecules such as c-fos, substance P, and calcitonin gene-related peptide (CGRP) in lumbar spinal cord. Cancer invasion into the bone was started from 7th day after transplantation and became evident at day 14. Objective increase of pain in the ipsilateral thigh was observed at day 14 on von Frey filament test and acetone test, while there was no remarkable regression of the tumors. In this model system, local radiation of tumor resulted in decrease in objective pain on von Frey filament test and acetone test. In the immunohistochemical stain for lumbar spinal cord, the expression of substance P and CGRP but not c-fos increased in tumor-bearing animal compared to the control. The expression of these molecules decreased in animals given local radiation. In summary, an animal model system was established for objective pain from cancer invasion into the bones. Local radiation of tumor induced objective pain relief and this effect seems to be mediated not by tumor regression but through altered production of pain-related molecules.

  14. Radiation-Induced Bystander Response: Mechanism and Clinical Implications

    Science.gov (United States)

    Suzuki, Keiji; Yamashita, Shunichi

    2014-01-01

    Significance: Absorption of energy from ionizing radiation (IR) to the genetic material in the cell gives rise to damage to DNA in a dose-dependent manner. There are two types of DNA damage; by a high dose (causing acute or deterministic effects) and by a low dose (related to chronic or stochastic effects), both of which induce different health effects. Among radiation effects, acute cutaneous radiation syndrome results from cell killing as a consequence of high-dose exposure. Recent advances: Recent advances in radiation biology and oncology have demonstrated that bystander effects, which are emerged in cells that have never been exposed, but neighboring irradiated cells, are also involved in radiation effects. Bystander effects are now recognized as an indispensable component of tissue response related to deleterious effects of IR. Critical issues: Evidence has indicated that nonapoptotic premature senescence is commonly observed in various tissues and organs. Senesced cells were found to secrete various proteins, including cytokines, chemokines, and growth factors, most of which are equivalent to those identified as bystander factors. Secreted factors could trigger cell proliferation, angiogenesis, cell migration, inflammatory response, etc., which provide a tissue microenvironment assisting tissue repair and remodeling. Future directions: Understandings of the mechanisms and physiological relevance of radiation-induced bystander effects are quite essential for the beneficial control of wound healing and care. Further studies should extend our knowledge of the mechanisms of bystander effects and mode of cell death in response to IR. PMID:24761341

  15. Radiation induced chemical reaction of carbon monoxide and hydrogen mixture

    International Nuclear Information System (INIS)

    Sugimoto, Shun-ichi; Nishii, Masanobu

    1985-01-01

    Previous studies of radiation induced chemical reactions of CO-H 2 mixture have revealed that the yields of oxygen containing products were larger than those of hydrocarbons. In the present study, methane was added to CO-H 2 mixture in order to increase further the yields of the oxygen containing products. The yields of most products except a few products such as formaldehyde increased with the addition of small amount of methane. Especially, the yields of trioxane and tetraoxane gave the maximum values when CO-H 2 mixture containing 1 mol% methane was irradiated. When large amounts of methane were added to the mixture, the yields of aldehydes and carboxylic acids having more than two carbon atoms increased, whereas those of trioxane and tetraoxane decreased. From the study at reaction temperature over the range of 200 to 473 K, it was found that the yields of aldehydes and carboxylic acids showed maxima at 323 K. The studies on the effects of addition of cationic scavenger (NH 3 ) and radical scavenger (O 2 ) on the products yields were also carried out on the CO-H 2 -CH 4 mixture. (author)

  16. Radiation cured coatings for high performance products

    International Nuclear Information System (INIS)

    Parkins, J.C.; Teesdale, D.H.

    1984-01-01

    Development over the past ten years of radiation curable coating and lacquer systems and the means of curing them has led to new products in the packaging, flooring, furniture and other industries. Solventless lacquer systems formulated with acrylates and other resins enable high levels of durability, scuff resistance and gloss to be achieved. Ultra violet and electron beam radiation curing are used, the choice depending on the nature of the coating, the product and the scale of the operation. (author)

  17. A novel topical protectant for the prevention of β-radiation induced moist desquamation

    International Nuclear Information System (INIS)

    Ma, L.; Wilcock, S.; Rezvani, M.; Hsia, C.

    2003-01-01

    Full text: Effective therapies for the prevention of radiation-induced skin burns that could be readily deployed under a nuclear accident or nuclear terrorism scenario are urgently needed. In this report we describe the efficacy of a novel radioprotectant (DMZ911) in a model of b-radiation induced moist desquamation (MD) in pig skin. DMZ911 is a nitroxide-based topical cream that effectively delivers the nitroxide into viable skin cells. Stable nitroxide compounds have been shown to be effective against both X-ray and ?-ray-induced damage in vivo and in vitro. A pig skin model of β-radiation-induced MD was employed in this study. Exposure to 30 Gy was used to induce skin lesions involving >80% moist desquamation in prescribed test sites on flank skin of female Large White pigs. DMZ911 or placebo was applied to various test sites 2 hours prior to radiation exposure. Lesions were scored based on the area of the test site containing 50% MD (severe) as determined by clinical assessment using blinded observers. Treatment with DMZ911 resulted in a 31% net reduction in MD when compared to placebo treated sites following an 8-week study period. This reduction was observed whether all sites or only those with severe MD were considered. Skin damage (as indicated by MD) from radiation exposure was significantly reduced by 31% (p = 0.05) following pretreatment with the novel topical radioprotectant DMZ911. This observation suggests that skin lesion development from radiation-induced oxidative damage cascades may be successfully inhibited by treatment with DMZ911. This topical therapeutic agent represents a novel treatment for nuclear radiation induced skin injury. DMZ911 may have unique applications in radiation oncology, cosmetic and therapeutic UV, laser, glycolic and dermabrasion procedures

  18. Caspase-independent cell death mediated by apoptosis-inducing factor (AIF) nuclear translocation is involved in ionizing radiation induced HepG2 cell death

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hengwen [Department of Radiation, Cancer Center of Guangdong General Hospital (Guangdong Academy of Medical Science), Guangzhou, 510080, Guangdong (China); Yang, Shana; Li, Jianhua [Department of Physiology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China); Zhang, Yajie [Department of Pathology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China); Gao, Dongsheng [Department of Oncology, Guangdong Medical College Affiliated Pengpai Memorial Hospital, Hai Feng, 516400, Gungdong (China); Zhao, Shenting, E-mail: zhaoshenting@126.com [Department of Physiology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China)

    2016-03-25

    Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world. The aim of radiotherapy is to eradicate cancer cells with ionizing radiation. Except for the caspase-dependent mechanism, several lines of evidence demonstrated that caspase-independent mechanism is directly involved in the cell death responding to irradiation. For this reason, defining the contribution of caspase-independent molecular mechanisms represents the main goal in radiotherapy. In this study, we focused on the role of apoptosis-inducing factor (AIF), the caspase-independent molecular, in ionizing radiation induced hepatocellular carcinoma cell line (HepG2) cell death. We found that ionizing radiation has no function on AIF expression in HepG2 cells, but could induce AIF release from the mitochondria and translocate into nuclei. Inhibition of AIF could reduce ionizing radiation induced HepG2 cell death. These studies strongly support a direct relationship between AIF nuclear translocation and radiation induced cell death. What's more, AIF nuclear translocation is caspase-independent manner, but not caspase-dependent manner, in this process. These new findings add a further attractive point of investigation to better define the complex interplay between caspase-independent cell death and radiation therapy. - Highlights: • AIF nuclear translocation is involved in ionizing radiation induced hepatocellular carcinoma cell line HepG2 cell death. • AIF mediated cell death induced by ionizing radiation is caspase-independent. • Caspase-independent pathway is involved in ionzing radiation induced HepG2 cell death.

  19. Caspase-independent cell death mediated by apoptosis-inducing factor (AIF) nuclear translocation is involved in ionizing radiation induced HepG2 cell death

    International Nuclear Information System (INIS)

    Sun, Hengwen; Yang, Shana; Li, Jianhua; Zhang, Yajie; Gao, Dongsheng; Zhao, Shenting

    2016-01-01

    Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world. The aim of radiotherapy is to eradicate cancer cells with ionizing radiation. Except for the caspase-dependent mechanism, several lines of evidence demonstrated that caspase-independent mechanism is directly involved in the cell death responding to irradiation. For this reason, defining the contribution of caspase-independent molecular mechanisms represents the main goal in radiotherapy. In this study, we focused on the role of apoptosis-inducing factor (AIF), the caspase-independent molecular, in ionizing radiation induced hepatocellular carcinoma cell line (HepG2) cell death. We found that ionizing radiation has no function on AIF expression in HepG2 cells, but could induce AIF release from the mitochondria and translocate into nuclei. Inhibition of AIF could reduce ionizing radiation induced HepG2 cell death. These studies strongly support a direct relationship between AIF nuclear translocation and radiation induced cell death. What's more, AIF nuclear translocation is caspase-independent manner, but not caspase-dependent manner, in this process. These new findings add a further attractive point of investigation to better define the complex interplay between caspase-independent cell death and radiation therapy. - Highlights: • AIF nuclear translocation is involved in ionizing radiation induced hepatocellular carcinoma cell line HepG2 cell death. • AIF mediated cell death induced by ionizing radiation is caspase-independent. • Caspase-independent pathway is involved in ionzing radiation induced HepG2 cell death.

  20. Effects of phenobarbital on taste aversion induced by x-radiation

    International Nuclear Information System (INIS)

    Jolicoeur, F.B.; Wayner, M.J.; Rondeau, D.B.; Merkel, A.D.; Bassano, D.A.

    1979-01-01

    The effects of phenobarbital on taste aversion induced by x-radiation were examined. Rats were adapted to a 23 hr 50 min water deprivation schedule. On the Treatment Day animals were given a novel 0.125% Na saccharin solution during the 10 min drinking session and were then exposed to 100 rads of x-radiation. The saccharin solution was presented again on six subsequent Test Days. Phenobarbital in doses of 20, 40, 60 and 80 mg/kg was adminstered 15 min prior to drinking on the first Test Day. Results demonstrate the phenobarbital in all doses tested has a significant attenuating effect on radiation induced taste aversion

  1. Ability of radiation therapists to assess radiation-induced skin toxicity

    International Nuclear Information System (INIS)

    Acharya, Urvi; Cox, Jennifer; Rinks, Marianne; Gaur, Pankaj; Back, Michael

    2013-01-01

    Radiation therapy has seen enhancement of the radiation therapist (RT) role, with RTs and nurses performing duties that were traditionally in the radiation oncologist's (RO) domain. This study aimed to assess whether RTs can consistently grade radiation-induced skin toxicity and their concordance with the gradings given by ROs. Digital photographs of skin reactions were taken at weeks 1, 3 and 6 of radiotherapy on nine patients with breast cancer. The randomly ordered photographs were reviewed once by eight ROs and four RO registrars and on two occasions separated by 6 weeks by 17 RTs. All graded the skin toxicities using the revised Radiation Therapy Oncology Group system. No significant difference was seen between the median scores of the RTs at the first scoring session and the RO/Registrar group. The RTs at both measurement times showed greater inter-rater reliability than the RO/Registrars (W=0.6866, time 1 and 0.6981 time 2, vs. 0.6517), with the experienced RTs the most consistent (W=0.7078). The RTs also showed high intra-rater reliability (rho=0.8461, P<0.0010). These results from RTs with no specific preparation indicate that experienced RTs could assess breast cancer skin toxicity as part of their role.

  2. Understanding the role of p53 in adaptive response to radiation-induced germline mutations

    International Nuclear Information System (INIS)

    Langlois, N.L.; Quinn, J.S.; Somers, C.M.; Boreham, D.R.; Mitchel, R.E.J.

    2003-01-01

    Full text: Radiation-induced adaptive response is now a widely studied area of radiation biology. Studies have demonstrated reduced levels of radiation-induced biological damage when an 'adaptive dose' is given before a higher 'challenge dose' compared to when the challenge dose is given alone. It has been shown in some systems to be a result of inducible cellular repair systems. The adaptive response has been clearly demonstrated in many model systems, however its impact on heritable effects in the mammalian germline has never been studied. Expanded Simple Tandem Repeat (ESTR) loci have been used as markers demonstrating that induced heritable mutations in mice follow a dose-response relationship. Recent data in our laboratory show preliminary evidence of radiation-induced adaptive response suppressing germline mutations at ESTR loci in wild type mice. The frequency of heritable mutations was significantly reduced when a priming dose of 0.1 Gy was given 24 hours prior to a 1 Gy acute challenging dose. We are now conducting a follow-up study to attempt to understand the mechanism of this adaptive response. P53 is known to play a significant role in governing apoptosis, DNA repair and cancer induction. In order to determine what function p53 has in the adaptive response for heritable mutations, we have mated radiation treated Trp53+/- male mice (C57Bl) to untreated, normal females (C57Bl). Using DNA fingerprinting, we are investigating the rate of inherited radiation-induced mutations on pre- and post-meiotic radiation-treated gametocytes by examining mutation frequencies in offspring DNA. If p53 is integral in the mechanism of adaptive response, we should not see an adaptive response in radiation-induced heritable mutations in these mice. This research is significant in that it will provide insight to understanding the mechanism behind radiation-induced adaptive response in the mammalian germline

  3. Non-targeted and delayed effects of exposure to ionizing radiation: I. Radiation-induced genomic instability and bystander effects in vitro

    Science.gov (United States)

    Morgan, William F.

    2003-01-01

    A long-standing dogma in the radiation sciences is that energy from radiation must be deposited in the cell nucleus to elicit a biological effect. A number of non-targeted, delayed effects of ionizing radiation have been described that challenge this dogma and pose new challenges to evaluating potential hazards associated with radiation exposure. These effects include induced genomic instability and non-targeted bystander effects. The in vitro evidence for non-targeted effects in radiation biology will be reviewed, but the question as to how one extrapolates from these in vitro observations to the risk of radiation-induced adverse health effects such as cancer remains open.

  4. Radiation-induced cancer of the skin in man

    International Nuclear Information System (INIS)

    Kiyono, Kunihiro; Moriya, Kumiko; Kobayashi, Toshio

    1981-01-01

    Eight cases of radiation induced cancer of the skin observed at the Shinshu University during 30 years from 1951 to 1938 were reported. All of the tumors were squamous cell carcinomas; 7 out of 8 cases occurred in males. Primary conditions for which irradiation was given were 6 cases of benign disorders of various skin disease and 2 cases of spinal tuberculosis. The mean age at which these patients were first subjected to radiation therapy was 31 years. At the time when the diagnosis of skin cancer was established, the mean age was 47 years, with a range from 35 to 58 years. The latent period distributed between 9 and 28 years, with the average of 16.4 years. The estimated radiation doses sufficient to induce cancer of the skin was found to be some thousands R or more, the lowest irradiation dose being about 2,000 R. There was no close correlation between the radiation dose and the latent period, nor between the age of the patient at the time of irradiation and the latent period. The tumors usually occurred in the skin areas where extensive irradiation changes were shown, especially in ulcerative area. (author)

  5. Radiation-induced mutagenicity and lethality in Salmonella typhimurium

    International Nuclear Information System (INIS)

    Isildar, M.; Bakale, G.

    1983-01-01

    The mutagenic and lethal effects of ionizing radiation on histidine-deficient auxotrophs of Salmonella typhimurium were studied to improve the understanding of radiation damage to DNA. The auxotrophs were divided into two groups - one which is sensitive to base-pair substitutions and another sensitive to frameshifts. These groups were composed of parent-daughter pairs in which the chemical mutagenicity enhancing plasmid, pKM101, is absent in the parent strain and present in the daughter. Co-60 #betta#-radiation and 250 kV x-rays were used to irradiate the bacteria. Irradiation of the frameshift - sensitive strains which carry the pKm101 plasmid doubled the absolute number of induced revertants whereas irradiation of the base-pair substitution sensitive strain which also carries the pKm101 plasmid produced nearly no change in the number of induced revertants. A nearly negligible effect on the mutation rate was observed for all parent strains

  6. State-dependent interaction in the antihistamine-induced disruption of a radiation-induced conditioned taste aversion

    International Nuclear Information System (INIS)

    Rabin, B.M.; Hunt, W.A.; Lee, J.

    1982-01-01

    Two experiments were run to evaluate the possibility that injection of antihistamine can produce a state-dependent acquisition of a radiation-induced conditioned taste aversion. In the first experiment, pretreating rats with the antihistamine chlorpheniramine maleate prior to their initial exposure to sucrose and to low-level irradiation on the conditioning day did not prevent the acquisition of a taste aversion to sucrose when the antihistamine was also administered prior to a subsequent preference test. In the second experiment, rats were both conditioned and tested for a radiation-induced aversion in a drug-free state. Under these condtions, the rats continued to show an aversion to sucrose despite pretreating them with chlorpheniramine prior to irradiation. Since rats conditioned under the antihistamine do not show the radiation-induced conditioned taste aversion when tested for sucrose preference in a nondrug state, it would seem that pretreating rats with an antihistamine prior to conditioning affects only the retrieval of the previously learned response and not its acquisition

  7. UV-B Radiation Induces Root Bending Through the Flavonoid-Mediated Auxin Pathway in Arabidopsis.

    Science.gov (United States)

    Wan, Jinpeng; Zhang, Ping; Wang, Ruling; Sun, Liangliang; Wang, Wenying; Zhou, Huakun; Xu, Jin

    2018-01-01

    Ultraviolet (UV)-B radiation-induced root bending has been reported; however, the underlying mechanisms largely remain unclear. Here, we investigate whether and how auxin and flavonoids are involved in UV-B radiation-induced root bending in Arabidopsis using physiological, pharmacological, and genetic approaches. UV-B radiation modulated the direction of root growth by decreasing IAA biosynthesis and affecting auxin distribution in the root tips, where reduced auxin accumulation and asymmetric auxin distribution were observed. UV-B radiation increased the distribution of auxin on the nonradiated side of the root tips, promoting growth and causing root bending. Further analysis indicated that UV-B induced an asymmetric accumulation of flavonoids; this pathway is involved in modulating the accumulation and asymmetric distribution of auxin in root tips and the subsequent redirection of root growth by altering the distribution of auxin carriers in response to UV-B radiation. Taken together, our results indicate that UV-B radiation-induced root bending occurred through a flavonoid-mediated phototropic response to UV-B radiation.

  8. Radiation-induced erectile dysfunction: Recent advances and future directions

    Directory of Open Access Journals (Sweden)

    Javed Mahmood, PhD

    2016-07-01

    Full Text Available Prostate cancer is one of the most prevalent cancers and the second leading cause of cancer-related deaths in men in the United States. A large number of patients undergo radiation therapy (RT as a standard care of treatment; however, RT causes erectile dysfunction (radiation-induced erectile dysfunction; RiED because of late side effects after RT that significantly affects quality of life of prostate cancer patients. Within 5 years of RT, approximately 50% of patients could develop RiED. Based on the past and current research findings and number of publications from our group, the precise mechanism of RiED is under exploration in detail. Recent investigations have shown prostate RT induces significant morphologic arterial damage with aberrant alterations in internal pudendal arterial tone. Prostatic RT also reduces motor function in the cavernous nerve which may attribute to axonal degeneration may contributing to RiED. Furthermore, the advances in radiogenomics such as radiation induced somatic mutation identification, copy number variation and genome-wide association studies has significantly facilitated identification of biomarkers that could be used to monitoring radiation-induced late toxicity and damage to the nerves; thus, genomic- and proteomic-based biomarkers could greatly improve treatment and minimize arterial tissue and nerve damage. Further, advanced technologies such as proton beam therapy that precisely target tumor and significantly reduce off-target damage to vital organs and healthy tissues. In this review, we summarize recent advances in RiED research and novel treatment modalities for RiED. We also discuss the possible molecular mechanism involved in the development of RiED in prostate cancer patients. Further, we discuss various readily available methods as well as novel strategies such as stem cell therapies, shockwave therapy, nerve grafting with tissue engineering, and nutritional supplementations might be used to

  9. Effect of bFGF on radiation-induced apoptosis of vascular endothelial cells

    International Nuclear Information System (INIS)

    Gu Qingyang; Wang Dewen; Li Yuejuan; Peng Ruiyun; Dong Bo; Wang Zhaohai; Liu Jie; Deng Hua; Jiang Tao

    2003-01-01

    Objective: To study the effect of bFGF on radiation-induced apoptosis vascular endothelial cells. Methods: A cell line PAE (porcine aortic endothelial cells) and primary cultured HUVEC (human umbilical vein endothelial cells) were irradiated with 60 Co γ-rays to establish cell apoptosis models. Flow cytometry with annexin-V-FITC + PI labeling was used to evaluate cell apoptosis. Different amounts of bFGF were used to study their effects on radiation-induced endothelial cell apoptosis. Results and Conclusions: It is found that bFGF could inhibit radiation-induced endothelial cell apoptosis in a considerable degree

  10. Radiation-induced cell mutations as a function of dose rate

    International Nuclear Information System (INIS)

    Kiefer, J.

    1987-01-01

    A brief review of the data in the literature is presented and forms the background of the experimental data given by the author obtained with exponential long-term cultures of V79 hamster cells exposed over a period of up to 35 days to different dose rates of gamma radiation. The experimental results show that at a dose rate of 40 mGy/hour the number of induced mutations is reduced, - which is in agreement with literature data - , but a dose rate of less than 30 mGy/hour makes the induced mutations leap to a value clearly higher than those induced by acute irradiation. As in addition to the mutations recombination is a significant factor of the radiation risk, experiments with a heterozygotic yeast strain have been made, as there is to date no reliable mammalian cell system available for this kind of research. Long-term radiation exposure of the yeast cells over a period of six weeks drastically increased the rate of recombinations, to a value higher by a factor of about 4 than that induced by acute irradiation. (orig.) [de

  11. Origin of specific chromosome aberration in radiation-induced leukemia

    International Nuclear Information System (INIS)

    Ban, Nobuhiko; Kai, Michiaki; Masuno, Yoko

    2005-01-01

    The theme in the title is discussed from the four aspects of specific chromosome aberration (sAb) patterns in radiation-induced leukemia (RIL), possibility for radiation to induce the sAb in RIL, any evidence for participation of delayed aberration to form sAb and the proportion of such healthy humans as having the specifically rearranged genome. Data of sAb observed in leukemia of 25 A-bomb survivors and of 38 patients post radiotherapy of cancers give a rather common pattern. However, many inconsistent results are obtained for sAb in patients post radiotherapy, A-bomb survivors, residents living in radio-contaminated houses in Taipei, in vitro exposure, and Chernobyl residents. At present, any clear evidence is available neither for sAb derived from the delayed aberration nor for estimating the proportion with the specifically rearranged gene. As above, it is unlikely that radiation induces such a translocation abnormality as BCR-ABL specifically seen in leukemia, and this aspect will be important for studies on the genesis of RIL and its risk assessment. (S.I.)

  12. An integrated model for radiation induced cancer

    International Nuclear Information System (INIS)

    Hall, E.J.; Varma, M.

    1994-01-01

    Risk estimates for radiation induced cancer are based on epidemiological data, principally the Japanese A bomb survivors. These estimates for radiation are better known than for any other environmental pollutant, but they do not relate directly to exposure to low doses and low dose rate. Recent rapid advances in molecular genetics, coupled with steady gains in cellular biology, radiation physics and chemistry led to the notion that the time may not be far off when it may be possible to arrive at human cancer risk estimates entirely from laboratory data. Whether risk estimates based on laboratory data will ever replace estimates based on epidemiological studies is an open question. What is clear is that laboratory data can supplement the present risk estimates by providing information on the relative effectiveness of high LET radiations, the importance of dose rate and dose protraction, and by identifying subpopulations which are unusually sensitive or resistant to radiation carcinogenesis. (author)

  13. Appearance of radiation-induced lesions after radiotherapy for Hodgkin's disease of the mediastinum and lungs

    Energy Technology Data Exchange (ETDEWEB)

    Zomer-Drozda, J [Instytut Onkologii, Warsaw (Poland)

    1976-01-01

    The incidence of radiation-induced lesions of lung tissue adjacent to the mediastinum and covered by radiation was established on the basis of a retrospective analysis of radiograms of 245 patients treated at the Institute of Oncology in Warsaw in the years 1951-1968, who received radiotherapy to the mediastinal lymph nodes. The radiation-induced lesions were divided into 4 grades depending on their extent and intensity of pulmonary tissue damage. Criteria for classification of radiation-induced fibrosis into the above mentioned grades were established. The correlation between radiation-induced injury and the doses of X-rays applied to the mediastinal lymph nodes was analysed. The importance of radiation-induced changes in the mediastinum and lungs for the diagnosis of recurrences in the irradiated fields, in the marginal areas and granulomatous infiltrations in pulmonary tissue is discussed.

  14. In vivo study of the adaptive response induced by radiation of different types

    International Nuclear Information System (INIS)

    Klokov, D.Yu.; Zaichkina, S.I.; Rozanova, O.M.; Aptikaeva, G.F.; Akhmadieva, A.Kh.; Smirnova, E.N.; Surkenova, G.N.; Kuzin, A.M.

    2000-01-01

    Low doses of X- and gamma-rays are known to induce the adaptive response (AR), i.e. a reduction in the damage caused by subsequent high doses. Using micronucleus test, we investigated the in vivo induction of AR in mouse bone marrow cells by low doses of radiation of different types. In our experiments we used low-LET gamma-radiation, high-LET secondary radiation from 70 GeV protons and secondary biogenic radiation. The latter is a novel type of radiation discovered only recently. Secondary biogenic radiation is known to be induced in biological objects after exposure to radiation and thought to be responsible for stimulating and protecting effects in cells in response to external irradiation. To expose mice to the secondary biogenic radiation, animals were housed in plastic cages containing gamma-irradiated oat seeds as bedding and food for 2 weeks before challenging with a high dose (1.5 Gy at a dose rate of 1 Gy/min) of 60 Co gamma-radiation. It was found that the yield of cytogenetic damage in mice exposed to both secondary biogenic and gamma-radiation was significantly reduced as compared to that in animals exposed to the challenge dose alone, i.e. the AR was induced. Pretreatment of animals with a low dose of gamma-radiation (0.1 Gy at a dose rate of 0.125 Gy/min) also induced the AR. In contrast, preliminary exposure of mice to a low dose (0.09 Gy at a dose rate of 1 Gy/min) of secondary radiation from 70 GeV protons induced no AR, suggesting that triggering the cascade of events leading to the AR induction depends on the DNA single-strand to double- strand breaks ratio. The precise mechanisms underlying the AR are of great importance since the phenomenon of AR can be used for medical benefits and in assessment of risks for carcinogens. But they have not been elucidated well at present. Taken together, our results suggest the crucial role of particular types of initial DNA lesions and the secondary biogenic radiation induced in cells in response to external

  15. Study on radiation-induced polymerization of vinyl monomers adsorbed on inorganic substances. II. Radiation-induced polymerization of methyl methacrylate adsorbed on several inorganic substances

    International Nuclear Information System (INIS)

    Fukano, K.; Kageyama, E.

    1975-01-01

    The radiation-induced polymerization of methyl methacrylate (MMA) adsorbed on such inorganic substances as silica gel, white carbon, silicic acid anhydride, zeolite, and activated alumina was carried out to compare with the case of styrene. The rate of radiation-induced polymerization adsorbed on inorganic substances was high compared with that of radiation-induced bulk state polymerization, as was the case with styrene. Inorganic substrates which contain aluminum as a component element are more likely to be grafted than those which consist of SiO 2 alone, as with styrene. The molecular weight distribution of unextractable polymer and extractable polymer differs, depending on the type of inorganic substance. Experiments by a preirradiation method were carried out in case of silica gel, white carbon, and silicic acid anhydride. GPC spectra of the polymer obtained were different from those of polymer formed by the simultaneous irradiation method. It appears that all the unextractable polymer is grafted to the inorganic surface with chemical bond

  16. The split-sting trait in Apis mellifera induced by cobalt 60 gamma radiation

    International Nuclear Information System (INIS)

    Silva, Vera Lucia Maciel

    1993-01-01

    The Split-Sting (SS) trait in honey bees, induced by gamma radiation, was discovered by Soares (1975). Bees with this trait are unable to sting, because the parts that compose the sting are separated. Many studies have been done in order to understand this new mutation. We studied the effect of gamma radiation on induction of the SS trait in feral bee strains. The doses were applied to the phase of larvae of queens with 5 days old. The following results were obtained: all doses of radiation induced the SS trait. There was an increase in the percentage of queens with SS with an increase in radiation dose; the SS trait induced by radiation is probably phenocopy; SS bees were observed in nature; increase of the rate mortality and malformation with an increase in radiation dose. (author)

  17. International Activities in Radiation-Induced Carcinogenesis. Survey Paper

    Energy Technology Data Exchange (ETDEWEB)

    Komarov, E. [World Health Organization, Geneva (Switzerland)

    1969-11-15

    During the past 10 years special attention has been paid to the problem of late effects of radiation and in particular to radiation-induced carcinogenesis and leukaemogenesis. In the UNSCEAR report of 1958-1962 this.problem was mentioned as being of considerable importance from the point of view of estimation of risk to the population from environmental radiation. In 1964 a special report was prepared by UNSCEAR on radiation- induced carcinogenesis. In the ICRP publication No. 8, a chapter dealing with assessment of somatic risks discussed the problem of leukaemia and other neoplasms and particularly stressed the problem of thyroid carcinoma-and bone sarcoma. WHO panels of experts discussed the problem in 1960-1966 and made some recommendations for international activity in this field. In spite of the amount of scientific attention that has been given in recent years to experimental radiobiology in animals and lower forms, it has become abundantly clear that information directly applicable to humans is woefully inadequate and that there is a desperate need for carefully collected data from man on which to base public health planning and day to day work in radiation protection. This has long been recognized in the technical program of WHO in the emphasis given to the practical importance of epidemiology in human radiobiology and the degree to which it depends upon international collaboration.

  18. Radiation induced mutations for plant selection

    International Nuclear Information System (INIS)

    Brunner, H.

    1994-01-01

    The successful use of plant breeding for improving crops requires the existence of genetic variation of useful traits. Unfortunately, the desired variation is often lacking. However, radiation can be used to induce mutations and thereby generate genetic variation from which desired mutants may be selected. Mutation induction has become a proven way of creating variation within a crop variety. It offers the possibility of inducing desired attributes that either cannot be expressed in nature or have been lost during evolution. More than 1700 mutant cultivars of crop plants with significantly improved attributes such as increased yield, improved quality, disease and stress resistance, have been released worldwide in the last thirty years. The Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture has contributed to these achievements through the promotion of research and development in mutation breeding techniques using nuclear and related biotechnological methods and the provision of in plant breeding is then transferred to Member States of the IAEA and the FAO through training in mutation breeding methods and the provision of technical advice. Moreover, radiation treatment services are provided to foster applications of nuclear techniques in crop improvement programmes of member states and more specifically to render direct support to plant breeders by efficient generation of mutations. Plant materials are standardized prior to radiation exposure to warrant reproducibility of the induced effects within practical limits and a radiosensitivity test is implemented to affirm useful doses for applied objectives of a request. This review deals with irradiation methods applied at the IAEA laboratories for the efficient induction of mutations in seeds, vegetative propagules and tissue and cell cultures and the establishment of genetically variable populations upon which selection of desired traits can be based. 3 tabs., 18 refs. (author)

  19. Dosimetric aspects of radiation processing of food and allied products

    International Nuclear Information System (INIS)

    Sharma, G.; Bhat, R.M.; Bhatt, B.C.

    2010-01-01

    Full text: Gamma radiation processing in the last 4-5 decades is continuously gaining importance in processing of a wide variety of products, as it can modify physical, chemical and biological properties of the materials, including food and allied products on industrial scale due its inherent qualities like ease of processing in finally packaged form, eco-friendly nature and other obvious reasons over conventional means of processing. Food and allied products are either from agricultural produce or animal origin; they get easily contaminated from soil during harvesting, handling, processing, environment conditions, storage and transport from various types of micro-organisms including pathogens. In many countries it is mandatory to bring down the population of micro-organisms to an acceptable level and complete elimination of pathogens before such products are accepted for human or animal consumption. Processing of food and allied products by radiation has its own challenges due to wider public acceptance of irradiated food, a wide range, 0.25-50kGy, of absorbed dose requirements for different category of such products and purposes, use of a variety of packaging materials in different shapes and sizes and because of its perishable nature. More than 50 countries including India in the world have accepted radiation processing of food and allied products by radiation. Dosimetry is an important aspect of radiation processing, whether it is food or allied product. Uniformity in dose delivered to these products depends on several factors such as product carrier to source frame alignment, product carrier and product/tote box design, product loading pattern, attenuation due to product thickness, product bulk density that varies from 0.1-1.0 kg/l and the plant design whether during processing product overlaps the source or otherwise. In this presentation dosimetric aspects of radiation processing of food and allied products and problems associated with dosimetry of such

  20. Induced radioactivity of materials by stray radiation fields at an electron accelerator

    CERN Document Server

    Rokni, S H; Gwise, T; Liu, J C; Roesler, S

    2002-01-01

    Samples of soil, water, aluminum, copper and iron were irradiated in the stray radiation field generated by the interaction of a 28.5 GeV electron beam in a copper-dump in the Beam Dump East facility at the Stanford Linear Accelerator Center. The specific activity induced in the samples was measured by gamma spectroscopy and other techniques. In addition, the isotope production in the samples was calculated with detailed Monte Carlo simulations using the FLUKA code. The calculated activities are compared to the experimental values and differences are discussed.

  1. Radiation induced color in topaz crystals

    International Nuclear Information System (INIS)

    Castagnet, A.C.; Rocca, H.C.C.; Rostilato, M.E.C.M.

    1989-08-01

    The presence of defects and impurities in the crystal lattice alters the eletric field distribution within the crystal, allowing the electrons to occupy energy levels in the forbbiden band. Ionizing radiation supply the required energy to permit the electrons originaly bound to lattice atoms, to occupy effectively those intermediate levels, forming color centers. Dependig upon the nature and energy of the radiation, it is possible to produce defects in regions of the crystal, generating color centers. Based on these premises, a technique to induce color in originally colorless topaz, by using the IEA-R1 nuclear reactor, was developed at Engineering and Industrial Application Department (TE). Samples were irradiated inside iron capsules coated with cadmium foils. The iron, and principaly the cadmium, absorb the thermal neutrons that could activate crystal impurities generating long-lived radioisotopes. The epithermal neutrons that overpass the iron and cadmium barriers interact with the crystal atoms, causing lattice defects which give rise to color center, by subsequent ionization processes. The procedure used at TE induces permanent blue color, in natural colorless topaz. (author) [pt

  2. Photoprotection beyond ultraviolet radiation--effective sun protection has to include protection against infrared A radiation-induced skin damage.

    Science.gov (United States)

    Schroeder, P; Calles, C; Benesova, T; Macaluso, F; Krutmann, J

    2010-01-01

    Solar radiation is well known to damage human skin, for example by causing premature skin ageing (i.e. photoageing). We have recently learned that this damage does not result from ultraviolet (UV) radiation alone, but also from longer wavelengths, in particular near-infrared radiation (IRA radiation, 760-1,440 nm). IRA radiation accounts for more than one third of the solar energy that reaches human skin. While infrared radiation of longer wavelengths (IRB and IRC) does not penetrate deeply into the skin, more than 65% of the shorter wavelength (IRA) reaches the dermis. IRA radiation has been demonstrated to alter the collagen equilibrium of the dermal extracellular matrix in at least two ways: (a) by leading to an increased expression of the collagen-degrading enzyme matrix metalloproteinase 1, and (b) by decreasing the de novo synthesis of the collagen itself. IRA radiation exposure therefore induces similar biological effects to UV radiation, but the underlying mechanisms are substantially different, specifically, the cellular response to IRA irradiation involves the mitochondrial electron transport chain. Effective sun protection requires specific strategies to prevent IRA radiation-induced skin damage. 2010 S. Karger AG, Basel.

  3. Radiation induced ionic polymerisation and grafting of vinyl monomers

    International Nuclear Information System (INIS)

    Stannett, V.T.

    1981-01-01

    Some special aspects of the radiation induced ionic polymerisation and grafting of vinyl monomers will be described. In particular the effects of solvents on the cationic polymerisation of the vinyl ethers will be discussed in detail. The unequivocal free ion nature of the polymerisation makes such information of considerable general interest. Estimates of the propagation rate constants with free cation polymerisation in solvents of different dielectric constants and solvation powers will be presented. Finally, some observations on the radiation induced graft polymerisation of ethyl vinyl ether to poly(vinyl chloride) and to polypropylene will be presented. (author)

  4. The application of microbeam in the research on radiation-induced bystander effects

    International Nuclear Information System (INIS)

    Xiong Jie; Han Ling

    2002-01-01

    There has been more and more attention to the phenomenon known as radiation-induced bystander effects, which will have a tremendous effect on the research in low -dose radiation biological effects. However, due to the stochastic nature of energy deposition and the random position of tracts, direct evidence for bystander effects and exact results of single particle interacts with a cell cannot be provided by using conventional broad-field irradiation. The availability of microbeam, especially the single particle microbeam in the world, whereby individual cells or precise location of cells can be irradiated with either a single or an exact number of particles provides a useful tool for the research on radiation-induced bystander effects. The author describes the radiation -induced bystander effect and the application of microbeam in the research on it

  5. Radiation-induced structural changes, (2)

    International Nuclear Information System (INIS)

    Ogasawara, M.; Matsuyama, T.

    1992-11-01

    This seminar is aimed at understanding both the physical and chemical aspects of the structural changes of materials induced by photons or ionizing radiation. The seminar was held on December 19th, 1991 and from February 13 to 14th, 1992 in this institute. The most active areas of the material science, in addition to the previous subjects, such as organic superconductors, silicon-based polymers, and fullerenes were included in this seminar. (J.P.N.)

  6. MiR-21 is involved in radiation-induced bystander effects

    Science.gov (United States)

    Xu, Shuai; Ding, Nan; Pei, Hailong; Hu, Wentao; Wei, Wenjun; Zhang, Xurui; Zhou, Guangming; Wang, Jufang

    2014-01-01

    Radiation-induced bystander effects are well-established phenomena, in which DNA damage responses are induced not only in the directly irradiated cells but also in the non-irradiated bystander cells through intercellular signal transmission. Recent studies hint that bystander effects are possibly mediated via small non-coding RNAs, especially microRNAs. Thus, more details about the roles of microRNA in bystander effects are urgently needed to be elucidated. Here we demonstrated that bystander effects were induced in human fetal lung MRC-5 fibroblasts through medium-mediated way by different types of radiation. We identified a set of differentially expressed microRNAs in the cell culture medium after irradiation, among which the up-regulation of miR-21 was further verified with qRT-PCR. In addition, we found significant upregulation of miR-21 in both directly irradiated cells and bystander cells, which was confirmed by the expression of miR-21 precursor and its target genes. Transfection of miR-21 mimics into non-irradiated MRC-5 cells caused bystander-like effects. Taken together, our data reveals that miR-21 is involved in radiation-induced bystander effects. Elucidation of such a miRNA-mediated bystander effect is of utmost importance in understanding the biological processes related to ionizing radiation and cell-to-cell communication. PMID:25483031

  7. Radiation-induced DNA damage as a function of DNA hydration

    International Nuclear Information System (INIS)

    Swarts, S.G.; Miao, L.; Wheeler, K.T.; Sevilla, M.D.; Becker, D.

    1995-01-01

    Radiation-induced DNA damage is produced from the sum of the radicals generated by the direct ionization of the DNA (direct effect) and by the reactions of the DNA with free radicals formed in the surrounding environment (indirect effect). The indirect effect has been believed to be the predominant contributor to radiation-induced intracellular DNA damage, mainly as the result of reactions of bulk water radicals (e.g., OH·) with DNA. However, recent evidence suggests that DNA damage, derived from the irradiation of water molecules that are tightly bound in the hydration layer, may occur as the result of the transfer of electron-loss centers (e.g. holes) and electrons from these water molecules to the DNA. Since this mechanism for damaging DNA more closely parallels that of the direct effect, the irradiation of these tightly bound water molecules may contribute to a quasi-direct effect. These water molecules comprise a large fraction of the water surrounding intracellular DNA and could account for a significant proportion of intracellular radiation-induced DNA damage. Consequently, the authors have attempted to characterize this quasi-direct effect to determine: (1) the extent of the DNA hydration layer that is involved with this effect, and (2) what influence this effect has on the types and quantities of radiation-induced DNA damage

  8. A mutant of a mutant of a mutant of a ...: Irradiation of progressive radiation-induced mutants in a mutation-breeding programme with Chrysanthenum morifolium RAM

    International Nuclear Information System (INIS)

    Broertjes, C.; Koene, P.; Veen, J.W.H. van.

    1980-01-01

    Radiation-induced sports in Chrysanthemum morifolium RAM. have been reported for several years. It has become an everyday practice to produce flower-colour mutants from outstanding cross-breeding products, even before they are distributed for the commercial production of cut flowers. One of the most successful and recent examples is that of cv. Horim, of which hundreds of mutants were produced by successive use of radiation-induced mutants in the mutation-breeding programme. Over about 4 years a variety of flower-colour mutants was obtained, not only largely including the outstanding characteristics of the original cultivar but sometimes even with an appreciable improvement in quality and yield. It is expected that the latter types, the Miros group, will soon completely supersede the spontaneous or raditation-induced Horim sports and mutants and take over the leading position of the Horim group in the production of all-year-round (AYR) cut-flowers. (orig.)

  9. Lessons learned using different mouse models during space radiation-induced lung tumorigenesis experiments

    Science.gov (United States)

    Wang, Jian; Zhang, Xiangming; Wang, Ping; Wang, Xiang; Farris, Alton B.; Wang, Ya

    2016-06-01

    Unlike terrestrial ionizing radiation, space radiation, especially galactic cosmic rays (GCR), contains high energy charged (HZE) particles with high linear energy transfer (LET). Due to a lack of epidemiologic data for high-LET radiation exposure, it is highly uncertain how high the carcinogenesis risk is for astronauts following exposure to space radiation during space missions. Therefore, using mouse models is necessary to evaluate the risk of space radiation-induced tumorigenesis; however, which mouse model is better for these studies remains uncertain. Since lung tumorigenesis is the leading cause of cancer death among both men and women, and low-LET radiation exposure increases human lung carcinogenesis, evaluating space radiation-induced lung tumorigenesis is critical to enable safe Mars missions. Here, by comparing lung tumorigenesis obtained from different mouse strains, as well as miR-21 in lung tissue/tumors and serum, we believe that wild type mice with a low spontaneous tumorigenesis background are ideal for evaluating the risk of space radiation-induced lung tumorigenesis, and circulating miR-21 from such mice model might be used as a biomarker for predicting the risk.

  10. The protective effects of vitamin C on hepatotoxicity induced by radiation

    International Nuclear Information System (INIS)

    Ahn, Ki Jung; Park, Sung Kwang; Cho, Heung Lae; Kang, Ki Mun; Chai, Gyu Young; Chung, Duck Wha; Kang, Jin Soon

    2004-01-01

    This study was carried out to determine the protective effects of vitamin C on the hepatotoxicity induced by radiation. The Spraque Dawley rats were randomly divided into 3 groups; the control group, the radiation exposed group, and the radiation and vitamin C-treated group. SOD activity catalase, malondialdehyde and liver enzymes were analyzed to assess the antioxidant effects of vitamin C. The increased level of malondialdehyde and the decreased catalase activity that were induced by radiation were improved after vitamin C but were was no statistical significance among three groups. The superoxide dismutase activity of the liver was increased by vitamin C, but there were no statistically significant differences between the vitamin C-treated group and the non vitamin C-treated group. The level of liver enzymes in sera such as glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, lactate dehyrogenase and alkaline phosphatase were remarkably elevated by radiation. The levels of those enzymes were decreased in the vitamin C-treated group and statistical significance was noted for the GPT level (ρ < 0.01). On the electromicrographic findings, the hepatic cell destruction was considerably decreased in the vitamin C-treated group. Vitamin C is thought to be an effective antioxidant against the hepatotoxicity induced by radiation

  11. Imaging Features that Discriminate between Foci Induced by High-and Low-LET Radiation in Human Fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Costes, Sylvain V.; Boissiere, Arnaud; Ravani, Shraddha; Romano,Raquel; Parvin, Bahram; Barcellos-Hoff, Mary Helen

    2006-10-08

    In this study, we investigated the formation ofradiation-induced foci in normal human fibroblasts exposed to X rays or130 keV/mum nitrogen ions using antibodies to phosphorylated proteinkinase ataxia telangiectasia mutated (ATMp) and histone H2AX(gamma-H2AX). High-content automatic image analysis was used to quantifythe immunofluorescence of radiation-induced foci. The size ofradiation-induced foci increased for both proteins over a 2-h periodafter nitrogen-ion irradiation, while the size of radiation-induced focidid not change after exposure to low-LET radiation. The number ofradiation-induced ATMp foci showed a more rapid rise and greaterfrequency after X-ray exposure and was resolved more rapidly such thatthe frequency of radiation-induced foci decreased by 90 percent comparedto 60 percent after exposure to high-LET radiation 2 h after 30 cGy. Incontrast, the kinetics of radiation-induced gamma-H2AX focus formationwas similar for high- and low-LET radiation in that it reached a plateauearly and remained constant for up to 2 h. High-resolution 3D images ofradiation-induced gamma-H2AX foci and dosimetry computation suggest thatmultiple double-strand breaks from nitrogen ions are encompassed withinlarge nuclear domains of 4.4 Mbp. Our work shows that the size andfrequency of radiation-induced foci vary as a function of radiationquality, dose, time and protein target. Thus, even though double-strandbreaks and radiation-induced foci are correlated, the dynamic nature ofboth contradicts their accepted equivalence for low doses of differentradiation qualities.

  12. Formation and accumulation of radiation-induced defects and radiolysis products in modified lithium orthosilicate pebbles with additions of titanium dioxide

    Science.gov (United States)

    Zarins, Arturs; Valtenbergs, Oskars; Kizane, Gunta; Supe, Arnis; Knitter, Regina; Kolb, Matthias H. H.; Leys, Oliver; Baumane, Larisa; Conka, Davis

    2016-03-01

    Lithium orthosilicate (Li4SiO4) pebbles with 2.5 wt.% excess of silicon dioxide (SiO2) are the European Union's designated reference tritium breeding ceramics for the Helium Cooled Pebble Bed (HCPB) Test Blanket Module (TBM). However, the latest irradiation experiments showed that the reference Li4SiO4 pebbles may crack and form fragments under operation conditions as expected in the HCPB TBM. Therefore, it has been suggested to change the chemical composition of the reference Li4SiO4 pebbles and to add titanium dioxide (TiO2), to obtain lithium metatitanate (Li2TiO3) as a second phase. The aim of this research was to investigate the formation and accumulation of radiation-induced defects (RD) and radiolysis products (RP) in the modified Li4SiO4 pebbles with different contents of TiO2 for the first time, in order to estimate and compare radiation stability. The reference and the modified Li4SiO4 pebbles were irradiated with accelerated electrons (E = 5 MeV) up to 5000 MGy absorbed dose at 300-990 K in a dry argon atmosphere. By using electron spin resonance (ESR) spectroscopy it was determined that in the modified Li4SiO4 pebbles, several paramagnetic RD and RP are formed and accumulated, like, E' centres (SiO33-/TiO33-), HC2 centres (SiO43-/TiO3-) etc. On the basis of the obtained results, it is concluded that the modified Li4SiO4 pebbles with TiO2 additions have comparable radiation stability with the reference pebbles.

  13. A schedule to demonstrate radiation-induced sister chromatid exchanges in human lymphocytes

    International Nuclear Information System (INIS)

    Chaudhuri, J.P.

    1982-01-01

    The reciprocal interchange between the chromatids of a chromosome, termed sister chromatid exchange (SCE), is considered to be one of the most sensitive and accurate cytogenetic parameters and respond to toxic chemicals at very low doses. But the response of SCE to ionizing radiation is very poor. Human lymphocytes fail to give SCE response when irradiated at G 0 . Probably the primary lesions induced at G 0 do not remain available long enough to find expression as SCEs. Based on this assumption a schedule was developed using caffeine to demonstrate radiation induced SCEs. Following this schedule a dose-dependent increase in the frequency of radiation induced SCEs has been observed. (orig.)

  14. Omega-3 Polyunsaturated Fatty Acids Attenuate Radiation-induced Oxidative Stress and Organ Dysfunctions in Rats

    International Nuclear Information System (INIS)

    Abdel Aziz, N.; Yacoub, S.F.

    2013-01-01

    The Aim of the present study was to determine the possible protective effect of omega-3 polyunsaturated fatty acids (omega-3 PUFA) against radiation-induced oxidative stress associated with organ dysfunctions. Omega-3 PUFA was administered by oral gavages to male albino rats at a dose of 0.4 g/ kg body wt daily for 4 weeks before whole body γ-irradiation with 4Gy. Significant increase of serum lipid peroxidation end product as malondialdehyde (MDA) along with the reduction in blood glutathione (GSH) content, superoxide dismutase (SOD) and glutathione peroxidase (GPX) enzyme activities were recorded on 3rd and 8th days post-irradiation. Oxidative stress was associated with a significant increase in lactate dehydrogenase (LDH) and creatine phosphokinase (CPK) enzyme activities, markers of heart damage, significant increases in uric acid, urea and creatinine levels, markers of kidney damage, significant increases of alkaline phosphatase (ALP) and transaminases (ALT and AST) activities, markers of liver damage. Moreover significant increases in total cholesterol and triglycerides levels were recorded. Omega-3 PUFA administration pre-irradiation significantly attenuated the radiation-induced oxidative stress and organ dysfunctions tested in this study. It could be concluded that oral supplementation of omega-3 PUFA before irradiation may afford protection against radiation-induced oxidative stress and might preserve the integrity of tissue functions of the organs under investigations.

  15. Radiation-induced mutation at minisatellite loci

    International Nuclear Information System (INIS)

    Dubrova, Y.E.; Nesterov, V.N.; Krouchinsky, N.G.

    1997-01-01

    We are studying the radiation-induced increase of mutation rate in minisatellite loci in mice and humans. Minisatellite mutations were scored by multilocus DNA fingerprint analysis in the progeny of γ-irradiated and non-irradiated mice. The frequency of mutation in offspring of irradiated males was 1.7 higher that in the control group. Germline mutation at human minisatellite loci was studied among children born in heavily polluted areas of the Mogilev district of Belarus after the Chernobyl accident and in a control population. The frequency of mutation assayed both by DNA fingerprinting and by eight single locus probes was found to be two times higher in the exposed families than in the control group. Furthermore, mutation rate was correlated with the parental radiation dose for chronic exposure 137 Cs, consistent with radiation-induction of germline mutation. The potential use of minisatellites in monitoring germline mutation in humans will be discussed

  16. Activating PTEN by COX-2 inhibitors antagonizes radiation-induced AKT activation contributing to radiosensitization

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Zhen [Central Laboratory, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081 (China); Department of Oral & Maxillofacial Surgery, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081 (China); Gan, Ye-Hua, E-mail: kqyehuagan@bjmu.edu.cn [Central Laboratory, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081 (China); Department of Oral & Maxillofacial Surgery, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081 (China)

    2015-05-01

    Radiotherapy is still one of the most effective nonsurgical treatments for many tumors. However, radioresistance remains a major impediment to radiotherapy. Although COX-2 inhibitors can induce radiosensitization, the underlying mechanism is not fully understood. In this study, we showed that COX-2 selective inhibitor celecoxib enhanced the radiation-induced inhibition of cell proliferation and apoptosis in HeLa and SACC-83 cells. Treatment with celecoxib alone dephosphorylated phosphatase and tensin homolog deleted on chromosome ten (PTEN), promoted PTEN membrane translocation or activation, and correspondingly dephosphorylated or inactivated protein kinase B (AKT). By contrast, treatment with radiation alone increased PTEN phosphorylation, inhibited PTEN membrane translocation and correspondingly activated AKT in the two cell lines. However, treatment with celecoxib or another COX-2 selective inhibitor (valdecoxib) completely blocked radiation-induced increase of PTEN phosphorylation, rescued radiation-induced decrease in PTEN membrane translocation, and correspondingly inactivated AKT. Moreover, celecoxib could also upregulate PTEN protein expression by downregulating Sp1 expression, thereby leading to the activation of PTEN transcription. Our results suggested that COX-2 inhibitors could enhance radiosensitization at least partially by activating PTEN to antagonize radiation-induced AKT activation. - Highlights: • COX-2 inhibitor, celecoxib, could enhance radiosensitization. • Radiation induced PTEN inactivation (phosphorylation) and AKT activation. • COX-2 inhibitor induced PTEN expression and activation, and inactivated AKT. • COX-2 inhibitor enhanced radiosensitization through activating PTEN.

  17. Bystander Effect Induced by UV Radiation; why should we be interested? 

    Directory of Open Access Journals (Sweden)

    Maria Widel

    2012-11-01

    Full Text Available The bystander effect, whose essence is an interaction of cells directly subjected to radiation with adjacent non-subjected cells, via molecular signals, is an important component of ionizing radiation action. However, knowledge of the bystander effect in the case of ultraviolet (UV radiation is quite limited. Reactive oxygen and nitrogen species generated by UV in exposed cells induce bystander effects in non-exposed cells, such as reduction in clonogenic cell survival and delayed cell death, oxidative DNA damage and gene mutations, induction of micronuclei, lipid peroxidation and apoptosis. Although the bystander effect after UV radiation has been recognized in cell culture systems, its occurrence in vivo has not been studied. However, solar UV radiation, which is the main source of UV in the environment, may induce in human dermal tissue an inflammatory response and immune suppression, events which can be considered as bystander effects of UV radiation. The oxidative damage to DNA, genomic instability and the inflammatory response may lead to carcinogenesis. UV radiation is considered one of the important etiologic factors for skin cancers, basal- and squamous-cell carcinomas and malignant melanoma. Based on the mechanisms of actions it seems that the UV-induced bystander effect can have some impact on skin damage (carcinogenesis?, and probably on cells of other tissues. The paper reviews the existing data about the UV-induced bystander effect and discusses a possible implication of this phenomenon for health risk. 

  18. Radiation-induced nondisjunction

    International Nuclear Information System (INIS)

    Uchida, I.A.

    1979-01-01

    The methodology and results of epidemiological studies of the effects of preconception diagnostic x-rays of the abdomen on chromosome segregation in humans are described. The vast majority of studies show the same positive, though not significant, trend to increased nondisjunction among the offspring of irradiated women. The results of the various studies, however, cannot be pooled because of differing methodologies used. Abnormal chromosome segregation during mitotic division has been inducted experimentally by the in vitro exposure of human lymphocytes to a low dose of 50 R gamma irradiation. First meiotic nondisjunction has been successfully induced by whole body exposure of female mice to a low dose of radiation. The question of time-related repair of the mechanism involved in chromosome segregation is raised

  19. Search for the lowest irradiation dose from literatures on radiation-induced cancer in uterus

    International Nuclear Information System (INIS)

    Yoshizawa, Yasuo; Kusama, Tomoko

    1975-01-01

    A survey of past case reports on radiation-induced cancer of the uterus was carried out with the main object of finding the lowest irradiation dose. Search of literature published since 1912 revealed 548 cases of radiation-induced cancer of the uterus. All of these cases of radiation-induced cancer had received radiation for the treatment of non-malignant disease. The primary gynecological conditions which were the object of radiation therapy were functional bleeding, endometrial hyperplasia, myoma, endometritis, and polyps. The lowest irradiation dose was estimated at 1000-1450 rad in the case of external X-ray irradiation, and 100 mg.hr for intrauterine radium therapy, which corresponds to 100-1000 rad. It was noted that were more cases of corpus cancer than cervical cancer. Histopathological findings of radiation-induced uterine cancer were carcinoma, sarcoma, and mixed mesodermal tumors. The latent period was distributed in the range of 1 to 40 years, with the average of 10.1 years. (auth.)

  20. Skin aspergillosis induced in the region of radiation ulcer

    International Nuclear Information System (INIS)

    Niimura, Yumiko; Nakauchi, Yohichi; Ushijima, Tsugako

    1980-01-01

    A case of skin aspergillosis in the region of radiation ulcer which was caused by Aspergillus fumigatus was reported. The patient was a 51 year-old man. This fungal infection was probably induced by a local factor, that is, chronic radiation ulcer. Histological findings suggested that Aspergillus fumigatus which increased saprophytically at the beginning possessed parasitic nature gradually, invaded into connective tissues in the deep layer of true skin, and made radiation ulcer more intractable. (Tsunoda, M.)

  1. 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)

  2. The Development of Countermeasures for Space Radiation Induced Adverse Health Effects

    Science.gov (United States)

    Kennedy, Ann

    The Development of Countermeasures for Space Radiation Induced Adverse Health Effects Ann R. Kennedy Department of Radiation Oncology, University of Pennsylvania School of Medicine, 195 John Morgan Building, 3620 Hamilton Walk, Philadelphia, PA, United States 19104-6072 The development of countermeasures for radiation induced adverse health effects is a lengthy process, particularly when the countermeasure/drug has not yet been evaluated in human trials. One example of a drug developed from the bench to the clinic is the soybean-derived Bowman-Birk inhibitor (BBI), which has been developed as a countermeasure for radiation induced cancer. It was originally identified as a compound/drug that could prevent the radiation induced carcinogenic process in an in vitro assay system in 1975. The first observation that BBI could inhibit carcinogenesis in animals was in 1985. BBI received Investigational New Drug (IND) Status with the U.S. Food and Drug Administration (FDA) in 1992 (after several years of negotiation with the FDA about the potential IND status of the drug), and human trials began at that time. Phase I, II and III human trials utilizing BBI have been performed under several INDs with the FDA, and an ongoing Phase III trial will be ending in the very near future. Thus, the drug has been in development for 35 years at this point, and it is still not a prescription drug on the market which is available for human use. A somewhat less time-consuming process is to evaluate compounds that are on the GRAS (Generally Recognized as Safe) list. These compounds would include some over-the-counter medications, such as antioxidant vitamins utilized in human trials at the levels for which Recommended Dietary Allowances (RDAs) have been established. To determine whether GRAS substances are able to have beneficial effects on radiation induced adverse health effects, it is still likely to be a lengthy process involving many years to potentially decades of human trial work. The

  3. Synergistic effects in radiation-induced particle ejection from solid surfaces

    International Nuclear Information System (INIS)

    Itoh, Noriaki

    1990-01-01

    A description is given on radiation-induced particle ejection from solid surfaces, emphasizing synergistic effects arising from multi-species particle irradiation and from irradiation under complex environments. First, it is pointed out that synergisms can be treated by introducing the effects of material modification on radiation-induced particle ejection. As examples of the effects of surface modification on the sputtering induced by elastic encounters, sputtering of alloys and chemical sputtering of graphite are briefly discussed. Then the particle ejection induced by electronic encounters is explained emphasizing the difference in the behaviors from materials to materials. The possible synergistic effects of electronic and elastic encounters are also described. Lastly, we point out the importance of understanding the elementary processes of material-particle interaction and of developing computer codes describing material behaviors under irradiation. (author)

  4. Subacute brain atrophy induced by radiation therapy to the malignant brain tumors

    International Nuclear Information System (INIS)

    Asai, Akio; Matsutani, Masao; Takakura, Kintomo.

    1987-01-01

    In order to analyze brain atrophy after radiation therapy to the brain tumors, we calculated a CSF-cranial volume ratio on CT scan as an index of brain atrophy, and estimated dementia-score by Hasegawa's method in 91 post-irradiated patients with malignant brain tumors. Radiation-induced brain atrophy was observed in 51 out of 91 patients (56 %) and dementia in 23 out of 47 patients (49 %). These two conditions were closely related, and observed significantly more often in aged and whole-brain-irradiated patients. As radiation-induced brain atrophy accompanied by dementia appeared 2 - 3 months after the completion of radiation therapy, it should be regarded as a subacute brain injury caused by radiation therapy. (author)

  5. Install and operate type radiation processing plant for marine products

    Energy Technology Data Exchange (ETDEWEB)

    Kohli, A.K. [BARC-BTIR Complex, Mumbai (India). Dept. of Atomic Energy. Board of Radiation and Isotope Technology

    2002-07-01

    Marine products can be carrier of several pathogens. Radiation processing is a very useful technique that is used to eliminate pathogens and also to extend shelf life of fresh fish. For marine products three processes are involved namely: radurization to pasteurize fresh chilled fish for extending shelf life; radicidation to sanitize frozen fishery products by elimination of pathogenic microorganisms and radiation disinfestations to eliminate insects from dehydrated fishery products. The paper brings out conceptual design of a compact radiation processing plant that can cater to all the three processes. The design is different from conveyor type of designs. The design is specially configured to maintain the temperature of frozen products and overdose ratio within limits specified. The throughput depends upon the source strength, type of product, the size of box and its configuration in which these could be arranged. The design has many features, which make it a very safe, convenient and economical method for processing of such items or for that matter all the food products, which are amenable for radiation processing. (author)

  6. Install and operate type radiation processing plant for marine products

    International Nuclear Information System (INIS)

    Kohli, A.K.

    2002-01-01

    Marine products can be carrier of several pathogens. Radiation processing is a very useful technique that is used to eliminate pathogens and also to extend shelf life of fresh fish. For marine products three processes are involved namely: radurization to pasteurize fresh chilled fish for extending shelf life; radicidation to sanitize frozen fishery products by elimination of pathogenic microorganisms and radiation disinfestations to eliminate insects from dehydrated fishery products. The paper brings out conceptual design of a compact radiation processing plant that can cater to all the three processes. The design is different from conveyor type of designs. The design is specially configured to maintain the temperature of frozen products and overdose ratio within limits specified. The throughput depends upon the source strength, type of product, the size of box and its configuration in which these could be arranged. The design has many features, which make it a very safe, convenient and economical method for processing of such items or for that matter all the food products, which are amenable for radiation processing. (author)

  7. Development of radiation-inducible promoters for use in nitric oxide synthase gene therapy of cancer

    International Nuclear Information System (INIS)

    Hirst, D.G.; Worthington, J.; Adams, C.; Robson, T.; Scott, S.D.

    2003-01-01

    Full text: The free radical nitric oxide (NO) at nM concentrations performs multiple signaling roles that are essential for survival. These processes are regulated via the enzymes nNOS and eNOS, but another isoform, inducible nitric oxide synthase (iNOS) is capable of generating much higher concentrations (mM) over longer periods, resulting in the generation of very toxic species such as peroxynitrite. At high concentrations NO has many of the characteristics of an ideal anticancer molecule: it is cytotoxic (pro-apoptotic via peroxynitrite), it is a potent chemical radiosensitizer, it is anti-angiogenic and anti-metastatic. Thus, we see iNOS gene therapy as a strategy for targeting the generation of high concentrations of NO to tumours for therapeutic benefit. iNOS gene therapy should be used in combination with radiotherapy; so it is logical that the use of a radiation-inducible promoter should be part of the targeting strategy. We have tested several candidate promoters in vitro and in vivo. The WAF1 promoter has many of the properties desirable for therapeutic use including: rapid 3-4 fold induction at X-ray doses of 2 and 4Gy and no significant leakiness. WAF1 also has the advantage of being inducible by hypoxia and by the final product, NO. We have also tested the synthetic CArG promoter and demonstrated that, in addition to a high level of radiation inducibility, it is also inducible by NO. We have also been able to demonstrate potent radiosensitization (SER 2.0-2.5) in tumour cells in vitro and in vivo using iNOS gene transfer with constitutive or radiation-inducible promoters. We have also tested the use of iNOS gene therapy in combination with cisplatin and shown significant enhancement

  8. A case of likely radiation-induced synchronous esophageal and skin carcinoma following post-operative radiation for breast cancer

    International Nuclear Information System (INIS)

    Kanogawa, Naoya; Shimada, Hideaki; Kainuma, Osamu; Cho, Akihiro; Yamamoto, Hiroshi; Itami, Makiko; Nagata, Matsuo

    2009-01-01

    A 71-year-old woman was admitted in January 2008 with on upper thoracic esophageal squamous cell carcinoma and a right chest wall skin tumor. When she was 32 years old, she had a radical mastectomy for right breast cancer and received postoperative radiation. Due to the presence of lung adhesions, trans-thoracic esophagectomy could not be done; thus, a blunt dissection was performed. She was discharged on the 19 th postoperative day. On pathology, a pT2N0M0 (pStage II) esophageal tumor was diagnosed. A resection of her skin tumor underwent 79 days after the esophageal surgery; on pathology, the skin tumor was diagnosed as a basal cell carcinoma. Since the esophageal tumor and the skin tumor occurred in the same area that had received radiation therapy, these tumors were diagnosed as being radiation-induced secondary tumors. In the English language medical literature, several reports of radiation-induced esophageal cancer occurring as a second cancer after radiotherapy for breast cancer have been published. Radiation-induced esophageal cancer rates may increase in Japan given the number of women who previously received radiotherapy for breast cancer. (author)

  9. Radiation-induced phase transformation in ferromagnetic perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Podsekin, A K; Dem' yanov, V V; Ivanova, V V; Venevtsev, Yu N [Nauchno-Issledovatel' skij Fiziko-Khimicheskij Inst., Moscow (USSR)

    1976-12-01

    An effect of neutron irradiation inducing a phase transition in ferromagnetic perovskite, Sr/sub 0.3/La/sub 0.7/MnO/sub 3/, has been discovered and studied. It is shown that a change in the Curie temperature is proportional to the dose of reactor irradiation. A decrease in the temperature of the phase transition with the concentration of radiation defects is accompanied by an increase in the electrical specific resistance and a change in the initial lattice parameters. It is shown that the radiation shift is due to at least two causes, viz. to an increase in the parameters of the elementary cell and the growth of the electrical specific resistance as a result of bounded electron states' forming on the radiation defects.

  10. Characterization of γ-radiation induced polymerization in ethyl methacrylate and methyl acrylate monomers solutions

    Science.gov (United States)

    Baccaro, Stefania; Casieri, Cinzia; Cemmi, Alessia; Chiarini, Marco; D'Aiuto, Virginia; Tortora, Mariagrazia

    2017-12-01

    The present work is focused on the γ-radiation induced polymerization of ethyl methacrylate (EMA) and methyl acrylate (MA) monomers mixture to obtain a co-polymer with specific features. The effect of the irradiation parameters (radiation absorbed dose, dose rate) and of the environmental atmosphere on the features of the final products was investigated. Attenuated Total Reflectance - Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Nuclear Magnetic Resonance high-resolution analyses of hydrogen and carbon nuclei (1H and 13C NMR) were applied to follow the γ-induced modifications by monitoring the co-polymerization process and allowed the irradiation parameters optimization. Diffusion-Ordered NMR (DOSY-NMR) data were used to evaluate the co-polymers polydispersity and polymerization degree. Since the last parameter is strongly influenced by the γ radiation and environmental conditions, a comparison among samples prepared and irradiated in air and under nitrogen atmosphere was carried out. In presence of oxygen, higher radiation was required to obtain a full solid co-polymer since a partial amount of energy released to the samples was involved in competitive processes, i.e. oxygen-containing free radicals formation and primary radicals recombination. Irrespectively to the environmental atmosphere, more homogeneous samples in term of polymerization degree dispersion was achieved at lower dose rates. At radiation absorbed doses higher than those needed for the formation of the co-polymer, while in case of samples irradiated in air heavy depolymerization was verified, a sensible increase of the samples stability was attained if the irradiation was performed under nitrogen atmosphere.

  11. Influence of radiation induced defect clusters on silicon particle detectors

    International Nuclear Information System (INIS)

    Junkes, Alexandra

    2011-10-01

    The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) addresses some of today's most fundamental questions of particle physics, like the existence of the Higgs boson and supersymmetry. Two large general-purpose experiments (ATLAS, CMS) are installed to detect the products of high energy protonproton and nucleon-nucleon collisions. Silicon detectors are largely employed in the innermost region, the tracking area of the experiments. The proven technology and large scale availability make them the favorite choice. Within the framework of the LHC upgrade to the high-luminosity LHC, the luminosity will be increased to L=10 35 cm -2 s -1 . In particular the pixel sensors in the innermost layers of the silicon trackers will be exposed to an extremely intense radiation field of mainly hadronic particles with fluences of up to Φ eq =10 16 cm -2 . The radiation induced bulk damage in silicon sensors will lead to a severe degradation of the performance during their operational time. This work focusses on the improvement of the radiation tolerance of silicon materials (Float Zone, Magnetic Czochralski, epitaxial silicon) based on the evaluation of radiation induced defects in the silicon lattice using the Deep Level Transient Spectroscopy and the Thermally Stimulated Current methods. It reveals the outstanding role of extended defects (clusters) on the degradation of sensor properties after hadron irradiation in contrast to previous works that treated effects as caused by point defects. It has been found that two cluster related defects are responsible for the main generation of leakage current, the E5 defects with a level in the band gap at E C -0.460 eV and E205a at E C -0.395 eV where E C is the energy of the edge of the conduction band. The E5 defect can be assigned to the tri-vacancy (V 3 ) defect. Furthermore, isochronal annealing experiments have shown that the V 3 defect exhibits a bistability, as does the leakage current. In oxygen

  12. Influence of radiation induced defect clusters on silicon particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Junkes, Alexandra

    2011-10-15

    The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) addresses some of today's most fundamental questions of particle physics, like the existence of the Higgs boson and supersymmetry. Two large general-purpose experiments (ATLAS, CMS) are installed to detect the products of high energy protonproton and nucleon-nucleon collisions. Silicon detectors are largely employed in the innermost region, the tracking area of the experiments. The proven technology and large scale availability make them the favorite choice. Within the framework of the LHC upgrade to the high-luminosity LHC, the luminosity will be increased to L=10{sup 35} cm{sup -2}s{sup -1}. In particular the pixel sensors in the innermost layers of the silicon trackers will be exposed to an extremely intense radiation field of mainly hadronic particles with fluences of up to {phi}{sub eq}=10{sup 16} cm{sup -2}. The radiation induced bulk damage in silicon sensors will lead to a severe degradation of the performance during their operational time. This work focusses on the improvement of the radiation tolerance of silicon materials (Float Zone, Magnetic Czochralski, epitaxial silicon) based on the evaluation of radiation induced defects in the silicon lattice using the Deep Level Transient Spectroscopy and the Thermally Stimulated Current methods. It reveals the outstanding role of extended defects (clusters) on the degradation of sensor properties after hadron irradiation in contrast to previous works that treated effects as caused by point defects. It has been found that two cluster related defects are responsible for the main generation of leakage current, the E5 defects with a level in the band gap at E{sub C}-0.460 eV and E205a at E{sub C}-0.395 eV where E{sub C} is the energy of the edge of the conduction band. The E5 defect can be assigned to the tri-vacancy (V{sub 3}) defect. Furthermore, isochronal annealing experiments have shown that the V{sub 3} defect

  13. Radiation induced sulfur dioxide removal

    International Nuclear Information System (INIS)

    Chmielewski, A.G.

    2000-01-01

    The biggest source of air pollution is the combustion of fossil fuels, were pollutants such as particulate, sulfur dioxide (SO 2 ), nitrogen oxides (NO x ), and volatile organic compounds (VOC) are emitted. Among these pollutants, sulfur dioxide plays the main role in acidification of the environment. The mechanism of sulfur dioxide transformation in the environment is partly photochemical. This is not direct photooxidation, however, but oxidation through formed radicals. Heterogenic reactions play an important role in this transformation as well; therefore, observations from environmental chemistry can be used in air pollution control engineering. One of the most promising technologies for desulfurization of the flue gases (and simultaneous denitrification) is radiation technology with an electron accelerator application. Contrary to the nitrogen oxides (NO x ) removal processes, which is based on pure radiation induced reactions, sulfur dioxide removal depends on two pathways: a thermochemical reaction in the presence of ammonia/water vapor and a radiation set of radiochemical reactions. The mechanism of these reactions and the consequent technological parameters of the process are discussed in this paper. The industrial application of this radiation technology is being implemented in an industrial pilot plant operated by INCT at EPS Kaweczyn. A full-scale industrial plant is currently in operation in China, and two others are under development in Japan and Poland. (author)

  14. Caffeine ameliorates radiation-induced skin reactions in mice but does not influence tumour radiation response

    Energy Technology Data Exchange (ETDEWEB)

    Hebbar, S.A.; Mitra, A.K.; George, K.C.; Verma, N.C. [Radiation Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai (India)]. E-mail: ncverma@apsara.barc.ernet.in

    2002-03-01

    Intramuscular administration of caffeine at a dose of 80 mg kg{sup -1} body weight to the gastrocnemius muscles of Swiss mice 5 min prior to local irradiation (35 Gy) of the leg delayed the progression of radiation-induced skin reactions in such animals. While 90% epilation with reddening of the skin was noted in animals treated with radiation alone, animals pretreated with caffeine suffered only partial hair loss with slight reddening of the skin on the 16th and 20th days post-irradiation. Beyond the 28th day, damage scores in irradiated feet for both the groups were similar (score 3) and remained unchanged until the 32nd day and then decreased and disappeared completely in both treatment groups by the 40th day after irradiation. In addition, the effect of caffeine on the radiation response of a mouse fibrosarcoma was investigated. Results showed that intratumoral administration of caffeine at a dose of 80 mg kg{sup -1} body weight 5 min prior to local exposure of tumours to 10 Gy of {sup 60}Co {gamma}-rays did not influence the response of tumours to radiation. The present study thus showed that although caffeine ameliorated radiation-induced skin reactions in the mouse leg, it did not affect the tumour radiation response, indicating its potential application in cancer radiotherapy. (author)

  15. Contribution to the study of radiation induced bone tissue cancer

    International Nuclear Information System (INIS)

    Bouet, Monique.

    1975-01-01

    In this work four original observations of more or less long-delayed cancers induced by ionizing radiations are compared with 34 other cases in the literature, after which an attempt is made to establish a general and prognostic synthesis of the results; the indications to emerge are as follows: - Ionizing radiation-induced cancers are very rare, especially when compared with the extensive therapeutic use made of X-rays; - The probability of radio-cancer formation, though no figures are given in the many papers consulted, seems nevertheless to be higher in cases of benign lesion irradiation; - Induced cancers have been observed after treatments with all types of radiation, whether or not the lesion is tumoral or cancerous, whatever the patient's age at the time of irradiations; - As a general rule these neoplasms appear after a variable latency period but usually from the 6th post-radiotherapy year onwards, with a greater frequency range between 6 and 12 years; - These induced cancers are generally epitheliomas or sarcomas, the latter being noticeably more predominant than in the case of spontaneous cancers. Leukoses may also be observed [fr

  16. Differential gene expression before and after ionizing radiation of subcutaneous fibroblasts identifies breast cancer patients resistant to radiation-induced fibrosis

    DEFF Research Database (Denmark)

    Alsner, Jan; Rødningen, Olaug K.; Overgaard, Jens

    2007-01-01

    BACKGROUND AND PURPOSE: Differentially gene expression between patients with either very low or very high risk of radiation-induced fibrosis (RIF) in patient-derived fibroblasts after irradiation has previously been reported. In the present study, we are investigating the robustness of radiation...... and changes in radiation-induced gene expression in fibroblasts. MATERIAL AND METHODS: Gene expression was analysed by quantitative real-time PCR before and after a fractionated scheme with 3x3.5Gy/3 days in fibroblasts derived from 26 patients with breast cancer treated with post-mastectomy radiotherapy....... RESULTS: Robust radiation-induced changes in gene expression were observed, with differential gene expression between low and high risk patients being most pronounced for the fold induction level ('after' value divided by 'before' value for each patient). When including patients with intermediate risk...

  17. Effect of salidroside on radiation-induced bone marrow adipogenesis

    International Nuclear Information System (INIS)

    Zhu Jincan; Chen Xiaoyu; Liu Chengcheng; Zhu Aizhen; Liu Shantao; Liu Gexiu

    2014-01-01

    Objective: To investigate the potential and underlying molecular mechanism of salidroside in ameliorating radiation-induced bone marrow adipogenesis and stimulating hematopoiesis. Methods: The female BALB/c mice aged 6-7 weeks were randomly divided into normal control group, radiation group and salidroside group. The radiation group and salidroside group were irradiated with 6.0 Gy of "6"0Co γ-rays. The salidroside group was intraperitoneally injected with 30 mg·kg"-"1·d"-"1 salidroside at 12 h and then every day until 8th d after radiation. The normal control group and radiation group were treated with equal volume of saline as control of salidroside. At 14 d after radiation, the mice weight, peripheral blood count, femur bone marrow histology, and the proportion of adipocyte area were measured, and the expressions of PPAR-γ and FABP4 were detected by q-PCR. Results: After irradiation, the numbers of white blood cells, hemoglobin and platelet in peripheral blood were reduced obviously, and the percentage of adipocyte area was increased significantly. Compared with mice in the radiation group, salidroside inhibited adipogenesis and reduced the proportion of adipocyte area (t = 13.31, P < 0.05) by reducing the expressions of PPAR-γ and FABP4 (t = 8.64, 13.19, P < 0.05). The number of white blood cells was partly recovered at 7 d after irradiation (t = 5.80, P < 0.05). Both white blood cells and hemoglobinin in peripheral blood of the salidroside group were higher than those in the radiation group at 14 d after irradiation. Conclusions: Salidroside could inhibit radiation-induced bone marrow adipogenesis and regulate bone marrow microenvironment, thereby promotes hematopoietic recovery in mice after radiation injury. (authors)

  18. Radiation-induced hypoxia may perpetuate late normal tissue injury

    International Nuclear Information System (INIS)

    Vujaskovic, Zeljko; Anscher, Mitchell S.; Feng, Q.-F.; Rabbani, Zahid N.; Amin, Khalid; Samulski, Thaddeus S.; Dewhirst, Mark W.; Haroon, Zishan A.

    2001-01-01

    Purpose: The purpose of this study was to determine whether or not hypoxia develops in rat lung tissue after radiation. Methods and Materials: Fisher-344 rats were irradiated to the right hemithorax using a single dose of 28 Gy. Pulmonary function was assessed by measuring the changes in respiratory rate every 2 weeks, for 6 months after irradiation. The hypoxia marker was administered 3 h before euthanasia. The tissues were harvested at 6 weeks and 6 months after irradiation and processed for immunohistochemistry. Results: A moderate hypoxia was detected in the rat lungs at 6 weeks after irradiation, before the onset of functional or histopathologic changes. The more severe hypoxia, that developed at the later time points (6 months) after irradiation, was associated with a significant increase in macrophage activity, collagen deposition, lung fibrosis, and elevation in the respiratory rate. Immunohistochemistry studies revealed an increase in TGF-β, VEGF, and CD-31 endothelial cell marker, suggesting a hypoxia-mediated activation of the profibrinogenic and proangiogenic pathways. Conclusion: A new paradigm of radiation-induced lung injury should consider postradiation hypoxia to be an important contributing factor mediating a continuous production of a number of inflammatory and fibrogenic cytokines

  19. Modification of radiation-induced murine thymic lymphoma incidence by curcumin

    International Nuclear Information System (INIS)

    Dange, P.S.; Yadav, H.D.; Kumar, Vimalesh; Bhilwade, H.N.; Pandey, B.N.; Sarma, H.D.

    2017-01-01

    Curcumin is a known antioxidant, preventing radiation damage including carcinogenesis. However, concentration and feeding schedule of curcumin in modification of radiation induced thymic lymphoma incidence in vivo model has not been studied. We report here modification of incidence of γ-radiation-induced thymic lymphoma in mice fed with different doses of curcumin (0.05 to 1 %) in diet. Results: Female Swiss mice (6-8 weeks) fed with normal diet and exposed to 3 Gy whole body "6"0Co γ-irradiation (WBI) showed 85 % incidence of thymic lymphoma (TL) at 120 days post-irradiation. A concentration of 1 % curcumin was found the most effective in TL incidence prevention than other fed concentrations. The TL incidence was remarkably reduced when curcumin was fed to the mice before than after the radiation exposure. These results suggest modification of TL incidence by curcumin in irradiated mice involving DNA damage and apoptotic death mechanisms

  20. Introduction of various amine groups onto polyethylene bead prepared by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Kim, M.S.; Choi, S.H.; Lee, K.P.

    2002-01-01

    Complete text of publication follows. Radiation-induced graft polymerization is a good method for modification of chemical and physical properties of polymeric materials because it can endow properties such as membrane quality, ion exchange, blood compatibility, dyeability, protein adsorption, and immobilization of bioactive materials. Polyethylene microbead is very useful material due to the following advantages; low price, simple purchase, high sensitivity, and simple analysis. On the other hand, the epoxy group of the glycidyl methacrylate (GMA) can easily be converted to the various functional groups such as amines, alcohols, phosphoric acid, sulfonic acid, and amino acid, etc. Cyclodextrin have been applied universally in various industries such as foods, cosmetics, pharmaceutical industry, analytical chemistry, and chemical industry. In order to obtain cyclodextrins, polyethylene microbead with the epoxy group were prepared by radiation-induced graft polymerization of GMA onto polyethylene microbead. The physical and chemical properties of the GMA-induced polyethylene microbeads were investigated by IR, thermal analysis (TGA/DSC), and SEM, respectively. Subsequently, the various amine groups such as diethylamine. diethylenetriamine, triethylamine, triethylenetetramine, and 1,6-hexanediamine were induced onto the epoxy group in polyethylene microbead. Finally, cyclodextrin glucanotransferase were immobilized onto polyethylene microbead with various amines under the various experimental conditions, such as pH, amin content, immobilization time, and etc. The activity of CGTase-immobilized polyethylene microbead was determined by Phenolphthein method. The production of the cyclodextrins from starch is in progress

  1. Modulation of radiation-induced apoptosis and G{sub 2}/M block in murine T-lymphoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Palayoor, S.T.; Macklis, R.M.; Bump, E.A.; Coleman, C.N. [Harvard Medical School, Boston, MA (United States)

    1995-03-01

    Radiation-induced apoptosis in lymphocyte-derived cell lines is characterized by endonucleolytic cleavage of cellular DNA within hours after radiation exposure. We have studied this phenomenon qualitatively (DNA gel electrophoresis) and quantitatively (diphenylamine reagent assay) in murine EL4 T-lymphoma cells exposed to {sup 137}Cs {gamma} irradiation. Fragmentation was discernible within 18-24 h after exposure. It increased with time and dose and reached a plateau after 8 Gy of {gamma} radiation. We studied the effect of several pharmacological agents on the radiation-induced G{sub 2}/M block and DNA fragmentation. The agents which reduced the radiation-induced G{sub 2}/M-phase arrest (caffeine, theobromine, theophylline and 2-aminopurine) enhanced the degree of DNA fragmentation at 24 h. In contrast, the agents which sustained the radiation-induced G{sub 2}/M-phase arrest (TPA, DBcAMP, IBMX and 3-aminobenzamide) inhibited the DNA fragmentation at 24 h. These studies on EL4 lymphoma cells are consistent with the hypothesis that cells with radiation-induced genetic damage are eliminated by apoptosis subsequent to a G{sub 2}/M block. Furthermore, it may be possible to modulate the process of radiation-induced apoptosis in lymphoma cells with pharmacological agents that modify the radiation-induced G{sub 2}/M block, and to use this effect in the treatment of patients with malignant disease. 59 refs., 7 figs.

  2. Induced radioactivity in Bevatron concrete radiation shielding blocks

    International Nuclear Information System (INIS)

    Moeller, G.C.; Donahue, R.J.

    1994-07-01

    The Bevatron accelerated protons up to 6.2 GeV and heavy ions up to 2.1 GeV/amu. It operated from 1954 to 1993. Radioactivity was induced in some concrete radiation shielding blocks by prompt radiation. Prompt radiation is primarily neutrons and protons that were generated by the Bevatron's primary beam interactions with targets and other materials. The goal was to identify the gamma-ray emitting nuclides (t 1/2 > 0.5 yr) that could be present in the concrete blocks and estimate the depth at which the maximum radioactivity presently occurs. It is shown that the majority of radioactivity was produced via thermal neutron capture by trace elements present in concrete. The depth of maximum thermal neutron flux, in theory, corresponds with the depth of maximum induced activity. To estimate the depth at which maximum activity occurs in the concrete blocks, the LAHET Code System was used to calculate the depth of maximum thermal neutron flux. The primary beam interactions that generate the neutrons are also modeled by the LAHET Code System

  3. Radiation-induced nondisjunction of oocytes of aged mice

    International Nuclear Information System (INIS)

    Uchida, I.A.; Freeman, C.P.V.

    1977-01-01

    It is stated that some human epidemiological studies suggest that there may be an association between chromosomal nondisjunction and pre-conception abdominal exposure to X-rays in women, and that this appears to increase with age. In order to test this, some experimental evidence was sought by studying second metaphase chromosomes of cultured oocytes of mice. It had previously been found that abnormal segregation was induced in young mice by exposing them to a low dose of whole body 137 Cs γ-radiation. The new studies confirmed that this radiosensitivity increases with age. The radiation dose was kept low to minimise chromosome breakage. The results indicated that abnormal segregation may be induced during first meiotic division by in vivo exposure of mouse ovaries to low radiation doses, and that this radiosensitivity appears to increase markedly with age. This supports a suggestion that the risk of producing trisomic off-spring in humans is increased with exposure of the abdomen to diagnostic X-rays, and that this increases with age. (U.K.)

  4. Leptin deficiency-induced obesity exacerbates ultraviolet B radiation-induced cyclooxygenase-2 expression and cell survival signals in ultraviolet B-irradiated mouse skin

    International Nuclear Information System (INIS)

    Sharma, Som D.; Katiyar, Santosh K.

    2010-01-01

    Obesity has been implicated in several inflammatory diseases and in different types of cancer. Chronic inflammation induced by exposure to ultraviolet (UV) radiation has been implicated in various skin diseases, including melanoma and nonmelanoma skin cancers. As the relationship between obesity and susceptibility to UV radiation-caused inflammation is not clearly understood, we assessed the role of obesity on UVB-induced inflammation, and mediators of this inflammatory response, using the genetically obese (leptin-deficient) mouse model. Leptin-deficient obese (ob/ob) mice and wild-type counterparts (C57/BL6 mice) were exposed to UVB radiation (120 mJ/cm 2 ) on alternate days for 1 month. The mice were then euthanized and skin samples collected for analysis of biomarkers of inflammatory responses using immunohistochemistry, western blotting, ELISA and real-time PCR. Here, we report that the levels of inflammatory responses were higher in the UVB-exposed skin of the ob/ob obese mice than those in the UVB-exposed skin of the wild-type non-obese mice. The levels of UVB-induced cyclooxygenase-2 expression, prostaglandin-E 2 production, proinflammatory cytokines (i.e., tumor necrosis factor-α, interleukin-1β, interleukin-6), and proliferating cell nuclear antigen and cell survival signals (phosphatidylinositol-3-kinase and p-Akt-Ser 473 ) were higher in the skin of the ob/ob obese mice than the those in skin of their wild-type non-obese counterparts. Compared with the wild-type non-obese mice, the leptin-deficient obese mice also exhibited greater activation of NF-κB/p65 and fewer apoptotic cells in the UVB-irradiated skin. Our study suggests for the first time that obesity in mice is associated with greater susceptibility to UVB-induced inflammatory responses and, therefore, obesity may increase susceptibility to UVB-induced inflammation-associated skin diseases, including the risk of skin cancer.

  5. Radiation-induced malignant tumors of skin and their histogenesis

    International Nuclear Information System (INIS)

    Li Guomin; Chen Yunchi; Yang Yejing

    1987-01-01

    Seven cases of radiation-induced malignant tumors and 60 cases of chronic radiation damage of skin are reported. Severe hyperplasia, false epitheliomatoid hyperpiasia and atypical proliferation of epithelia and atypical proliferation of fibrohistocytes were the main changes found in chronic radiation damage of skin. The development of malignant tumors from chronic radiation damage of skin can be divided into 4 periods: necrotic and degenerative change period, benign proliferative period, atypical proliferative period and malignant change period. The incidence of hyperplastic changes of skin is related to the time elapse after irradiation and the integrated dose of radiation. The longer the duration after irradiation and the larger the integrated dose are, the higher will be the incidence of hyperplastic changes

  6. A mathematical model for leukemogenesis of radiation-induced acute myeloid leukemia in C3H/He mice

    International Nuclear Information System (INIS)

    Kai, M.; Ban, N.

    2002-01-01

    We developed a mathematical model in leukemogenesis of acute myeloid leukemia(AML) in C3H/He mice irradiated. Our previous study indicated that the leukemogenesis of AML was associated with a deletion of chromosome 2 directly induced by acute radiation. We hypothesized that radiation-induced AML needs both inactivation of one allele of a causative gene directly induced by acute radiation and another mutational event at the other allele. We analyzed data using a two-stage stochastic model for carcinogenesis. Model fitting was based on the maximum likelihood method. Our model analysis suggested that a single exposure might induce the long-lasting delayed cell death of radiation-induced initiated cells, and that the incidence of AML may be determined through both radiation-induced initiation and persistent increase of delayed cell death of the initiated cell induced by radiation

  7. Factors determining radiation-induced mixing at interfaces

    International Nuclear Information System (INIS)

    Collins, R.

    1986-01-01

    A review is given of the principal mechanisms contributing to atomic mixing produced by ion beams at initially well-defined interfaces between solid phases. Their relative importance is discussed in the light of available experimental evidence, and a critical survey is given of current mathematical models. The case of a thin interior implant layer is included. Those aspects of surface sputtering of direct relevance to the construction of the mixing equations are examined. Mixing mechanisms considered are ballistic relocation, diffusion, radiation-induced segregation, and drifts induced by chemical affinities of the elements concerned, together with constraints on all these from packing (Kirkendall) effects. Ballistic terms are subdivided into direct-recoil and cascade contributions. A brief review is given of the established methods of modelling them by using relocation integral cross-sections, and also the limitations and advantages of their approximation by differential equations of Fokker-Planck (diffusion) type. Genuinely diffusive mechanisms involved are thermal and radiation-enhanced diffusion; the question of the most appropriate form of Fick's law to use in each case is considered. The packing effects may be modelled either as a lattice relaxation to be imposed following each radiation dose increment, or as a continuously computed reversed collective current of atoms. These two approaches are discussed. (author)

  8. Mechanisms of transient radiation-induced creep

    International Nuclear Information System (INIS)

    Pyatiletov, Yu.S.

    1981-01-01

    Radiation-induced creep at the transient stage is investigated for metals. The situation, when several possible creep mechanisms operate simultaneously is studied. Among them revealed are those which give the main contribution and determine thereby the creep behaviour. The time dependence of creep rate and its relation to the smelling rate is obtained. The results satisfactorily agree with the available experimental data [ru

  9. Cellular therapy to treat ionizing radiation-induced cutaneous radiation syndrome: 2 cases report

    International Nuclear Information System (INIS)

    Benderitter, M.; Chapel, A.; Trompier, F.; Clairand, I.; Bottolier-Depois, J.F.; Gourmelon, P.; Bey, E.; Lataillade, J.J.

    2008-01-01

    Full Text: Localized irradiation at high dose exposition could induce severe radiation burns characterized by the occurrence of unpredictable successive inflammatory waves leading to the extension in surface and depth of necrotic processes. The medical management of these severe radiation burns remains today a challenging issue unresolved by the classical therapeutical approach. For the first time, two victims (accident of Chile, 2006 and accident of Senegal, 2007) accidentally exposed to an iridium gammagraphy radioactive source experienced a new and innovative therapeutic strategy combining dosimetry-guided surgery lesion excision and injection of MSC. The clinical evolution was remarkable. The clinical transfer of this therapeutic option was possible based on the research perform in the Institute and the IRSN/Percy hospital cooperation. Our data suggested that cellular therapy based on Mesenchymal Stem Cell (MSC) injection could be used to repair numerous injured tissues. We have studied the potential use of human MSC (hMSC) in order to limit radiation-induced skin lesions. Our pre-clinical data suggest a possible use of hMSC for the treatment of the early phase of the cutaneous radiation syndrome. The understanding of the precise healing mechanisms of hMSC in animal model is under investigation. These results will be helpful to generalize this innovative therapy to the treatment of other radiological complications. (author)

  10. Social impacts induced by radiation risk in Fukushima prefecture

    International Nuclear Information System (INIS)

    Murayama, Takehiko

    2011-01-01

    An accident of Fukushima Daiichi nuclear power plant induced by an earthquake of M9.0 and subsequent tsunami gave various kinds of impacts around the plant. After reviewing arguments of local governments for low dose radiation risk, this paper analyzed social impacts by the risk in terms of a gap of emergency response between national and local governments, corruption of communities in various levels induced by plural statements for risk levels in low level radiation, and economic impacts for agricultural crops made in Fukushima prefecture. Afterwards, clues for improving the situation were discussed, which include understanding of characteristics of public perception, attitudes of experts and interactive risk communication. (author)

  11. Effect of stacking fault energy on the neutron radiation induced defect accumulation in stainless steels

    International Nuclear Information System (INIS)

    Li Xiaoqiang; Al Mazouzi Abderrahim

    2009-01-01

    Current knowledge highlights the radiation induced segregation (RIS) and the radiation hardening as the two main effects on irradiation assisted stress corrosion cracking (IASCC). Stacking fault energy is considered as a key parameter of materials, which can influence IASCC of stainless steels in nuclear light water reactor (LWR), because it plays an important role in every process of plastic deformation, work hardening and creep behaviour. The study of the impact of SFE variations on the plastic deformation and SCC behaviour of irradiated and unirradiated austenitic steels will contribute to the understanding of IASCC mechanism. The objectives of this work, as a task within the FP6-European Project PERFECT, are to investigate the influence of the SFE on IASCC susceptibility of stainless steels, to correlation n-irradiation induced defect production, accumulation and mechanical deformation behaviour with SFE by using the state of the art experimental tools such as transmission electron microscope (TEM), positron annihilation spectroscopy (PAS), slow strain rate tests (SSRT) in simulated LWR conditions

  12. Radiation-induced gastrointestinal toxicity. Pathophysiologie, approaches to treatment and prophylaxis

    International Nuclear Information System (INIS)

    Classen, J.; Belka, C.; Paulsen, F.; Budach, W.; Hoffmann, W.; Bamberg, M.

    1998-01-01

    Background: Gastrointestinal toxicity is frequently observed during radiotherapy of malignancies in the abdomen and pelvis. The proposed pathophysiology of radiation enteritis is complex and a variety of different treatment strategies have been suggested for the management of acute radiation-induced diarrhea. Material and methods: Data are presented from an extensive review of the current literature. Results: Radiation-induced diarrhea results from a variety of different pathophysiological mechanisms including malabsorption of bile salts and lactose, imbalances in local bacterial flora and changes in the intestinal patterns of motility. Up to date acute radiation diarrhea is predominantly treated symptomatically using opioide derivates (loperamide) or adsorbants of bile salts such as smectite. Clinical trials have been performed using L. acidophilus, smectite or sucralfate for diarrhea prophylaxis with moderate reduction of acute symptoms. Conclusions: Further evaluation of strategies for diarrhea prophylaxis is warranted. Due to the complex nature of radiation enteritis a multimodal approach taking into account alterations in intestinal motility patterns, malabsorption of bile salts and an imbalance of mucosal bacterial flora may offer new perspectives. (orig.) [de

  13. Status of radiation sterilization of healthcare products in China

    International Nuclear Information System (INIS)

    Zhu Nankang; Wang Chunlei; Teng Weifang

    2004-01-01

    This paper describes the status of 60 Co radiation facilities both in service and under construction in China and examines the future market for radiation sterilization of healthcare products. Policies for developing the industry of radiation sterilization are also put forward; these include implementation of appropriate quality systems, scale-up and merging of existing radiation facilities, development of electron beam radiation for sterilization purposes and increasing awareness of the technology of radiation sterilization

  14. Radiation treatment of foodstuffs

    International Nuclear Information System (INIS)

    Luther, T.; Huebner, G.

    1990-10-01

    In addition to fundamental demands on radiation and safety engineering of irradiation facilities, the necessity arises to optimize irradiation conditions by using facilities to capacity and thus reducing irradiation costs. The following subjects are dealt with in detail: rehabilitation of a pilot plant for radiation treatment of onions; examination of radiation resistance of components and equipment parts of food irradiation facilities; chemical dosimetry; relative measurement of the intensity of radioactive sources; thermo- and chemiluminescence to prove irradiation of foodstuffs; radiation induced sprout inhibition of potatoes; laboratory tests of delayed maturation of tomatoes; radiation treatment of strawberries; radiation treatment of forage; radiation induced sprout inhibition of acid-treated onions; radiation treatment of starch and potatoe products; radiation treatment of cosmetics; the universal radiation source UNI 88/26 for gamma irradiation facilities; microbiological aspects of food irradiation, and introduction of chicken irradiation on an industrial scale. (BBR) [de

  15. The Use of Membranes Prepared by Radiation - Induced Grafting in Waste Water Treatment

    International Nuclear Information System (INIS)

    El-Arnaouty, M.B.; Abdel Aal, S.E.; Dessouki, A.M.

    2000-01-01

    Membranes were prepared by the radiation-induced grafting of N-vinylpyrrolidone onto low density polyethylene and the possibility for their practical use in the removal of two dyes: Acid red 116(Erionyl red 2B) and blue reactive (Brilliant bright blue) was studied. The effect of the degree of grafting on the adsorption of these pollutants was investigated and showed maximum adsorption occurred at 394 % grafting. Radiation degradation of the dyes with a dose of ∼ 5 KGy was followed by adsorption of the residual concentration of the dyes by the membranes, which resulted in the complete removal of these pollutants as well as the radiolysis products present in the irradiated solutions. Also, characterization of the membranes before and after adsorption was carried out using thermogravimetric analysis and scanning electron microscopy

  16. Comparison and evaluation of gridded radiation products across northern Eurasia

    International Nuclear Information System (INIS)

    Troy, T J; Wood, E F

    2009-01-01

    Northern Eurasia is a region experiencing documented changes in temperature and large-scale streamflow, yet little attention has been focused on the large-scale energy budgets over the region. We compare station data and gridded radiation products from reanalysis and remote sensing to evaluate the radiative fluxes across northern Eurasia. On annual timescales, we find that the downward shortwave radiation products, with the exception of those of the NCEP/NCAR reanalysis, compare well with long-term station observations, but that this agreement breaks down with smaller timescales and for downward longwave and upward shortwave and longwave radiation. Of the six gridded products, the Surface Radiation Budget data set performs the best as compared to observations. Differences in radiative fluxes are on the order of 15-20 W m -2 on seasonal timescales, averaged across the region, with larger variations spatially and at smaller timescales. The resulting uncertainty in net radiation has implications for climate and hydrologic analyses that seek to understand changes in northern Eurasia climate and its hydrologic cycle.

  17. In vivo evaluation on organ degeneration using radiation technology

    International Nuclear Information System (INIS)

    Kim, Sung Ho; Moon, C. J.; Kim, S. R.

    2010-05-01

    The purpose of this study is to investigate the effect of developed product on skin and reproductive system of animal due to irradiation via in vivo test, and finally acquire fundamental data for evaluation of protective materials on degenerative damages. - Evaluate the effect of candidate materials on UV-induced skin damages · Test the effect of candidate materials to protect the skin from photodamage, the gross and microscopic changes in the skin of hairless mice and materials-treated mice exposed chronically to UV - Evaluate the effect of developed product (HemoHIM) on radiation-induced reproductive system (female) damages - Evaluate the effect of developed product (HemoHIM) on chemical-induced reproductive system (female) damages - Evaluate the effect of developed product (HemoHIM) on radiation-induced reproductive system (male) damages - Evaluate the effect of developed product (HemoHIM) on chemical-induced reproductive system (male) damages

  18. Bio-molecular alterations induced by a chemical or radiating stress in isolated human cells

    International Nuclear Information System (INIS)

    Gault, N.

    2004-01-01

    After having recalled some aspects of radiobiology (effects of ionizing radiations, molecular targets of radiations, cellular responses with respect to the radiation), the author discusses various aspects of radio-sensitivity: intrinsic radio-sensitivity of tumoral and normal cells, DNA injuries and in vitro radio-sensitivity, genes of susceptibility to ionizing radiations, clustered injuries. Then she reports investigations performed by infrared micro-spectroscopy: characterization of pathological lines, of biological processes, of oxidative injuries induced by xenobiotics, of injuries induced by ionizing radiations

  19. Kinetics of radiation-induced precipitation at the alloy surface

    Science.gov (United States)

    Lam, N. Q.; Nguyen, T.; Leaf, G. K.; Yip, S.

    1988-05-01

    Radiation-induced precipitation of a new phase at the surface of an alloy during irradiation at elevated temperatures was studied with the aid of a kinetic model of segregation. The preferential coupling of solute atoms with the defect fluxes gives rise to a strong solute enrichment at the surface, which, if surpassing the solute solubility limit, leads to the formation of a precipitate layer. The moving precipitate/matrix interface was accommodated by means of a mathematical scheme that transforms spatial coordinates into a reference frame in which the boundaries are immobile. Sample calculations were performed for precipitation of the γ'-Ni 3Si layer on Ni-Si alloys undergoing electron irradiation. The dependences of the precipitation kinetics on the defect-production rate, irradiation temperature, internal defect sink concentration and alloy composition were investigated systematically.

  20. Lovastatin attenuates ionizing radiation-induced normal tissue damage in vivo

    International Nuclear Information System (INIS)

    Ostrau, Christian; Huelsenbeck, Johannes; Herzog, Melanie; Schad, Arno; Torzewski, Michael; Lackner, Karl J.; Fritz, Gerhard

    2009-01-01

    Background and purpose: HMG-CoA-reductase inhibitors (statins) are widely used lipid-lowering drugs. Moreover, they have pleiotropic effects on cellular stress responses, proliferation and apoptosis in vitro. Here, we investigated whether lovastatin attenuates acute and subchronic ionizing radiation-induced normal tissue toxicity in vivo. Materials and methods: Four hours to 24 h after total body irradiation (6 Gy) of Balb/c mice, acute pro-inflammatory and pro-fibrotic responses were analyzed. To comprise subchronic radiation toxicity, mice were irradiated twice with 2.5 Gy and analyses were performed 3 weeks after the first radiation treatment. Molecular markers of inflammation and fibrosis as well as organ toxicities were measured. Results: Lovastatin attenuated IR-induced activation of NF-κB, mRNA expression of cell adhesion molecules and mRNA expression of pro-inflammatory and pro-fibrotic marker genes (i.e. TNFα, IL-6, TGFβ, CTGF, and type I and type III collagen) in a tissue- and time-dependent manner. γH2AX phosphorylation stimulated by IR was not affected by lovastatin, indicating that the statin has no major impact on the induction of DNA damage in vivo. Radiation-induced thrombopenia was significantly alleviated by lovastatin. Conclusions: Lovastatin inhibits both acute and subchronic IR-induced pro-inflammatory and pro-fibrotic responses and cell death in normal tissue in vivo. Therefore, lovastatin might be useful for selectively attenuating acute and subchronic normal tissue damage caused by radiotherapy.

  1. Molecular targets in radiation-induced blood-brain barrier disruption

    International Nuclear Information System (INIS)

    Nordal, Robert A.; Wong, C. Shun

    2005-01-01

    Disruption of the blood-brain barrier (BBB) is a key feature of radiation injury to the central nervous system. Studies suggest that endothelial cell apoptosis, gene expression changes, and alteration of the microenvironment are important in initiation and progression of injury. Although substantial effort has been directed at understanding the impact of radiation on endothelial cells and oligodendrocytes, growing evidence suggests that other cell types, including astrocytes, are important in responses that include induced gene expression and microenvironmental changes. Endothelial apoptosis is important in early BBB disruption. Hypoxia and oxidative stress in the later period that precedes tissue damage might lead to astrocytic responses that impact cell survival and cell interactions. Cell death, gene expression changes, and a toxic microenvironment can be viewed as interacting elements in a model of radiation-induced disruption of the BBB. These processes implicate particular genes and proteins as targets in potential strategies for neuroprotection

  2. Thermal hadron production by QCD Hawking radiation

    International Nuclear Information System (INIS)

    Satz, Helmut

    2007-01-01

    The QCD counterpart of Hawking radiation from black holes leads to thermal hadron production in high energy collisions, from e + e - annihilation to heavy ion interactions. This hadronic radiation is emitted at a universal temperature T≅(σ/2π) 1/2 , where the string tension σ measures the colour field at the event horizon of confinement. Moreover, the emitted radiation is thermal 'at birth'; since the event horizon prevents all information transfer, no memory has to be destroyed kinetically. (author)

  3. Lessons learned using different mouse models during space radiation-induced lung tumorigenesis experiments.

    Science.gov (United States)

    Wang, Jian; Zhang, Xiangming; Wang, Ping; Wang, Xiang; Farris, Alton B; Wang, Ya

    2016-06-01

    Unlike terrestrial ionizing radiation, space radiation, especially galactic cosmic rays (GCR), contains high energy charged (HZE) particles with high linear energy transfer (LET). Due to a lack of epidemiologic data for high-LET radiation exposure, it is highly uncertain how high the carcinogenesis risk is for astronauts following exposure to space radiation during space missions. Therefore, using mouse models is necessary to evaluate the risk of space radiation-induced tumorigenesis; however, which mouse model is better for these studies remains uncertain. Since lung tumorigenesis is the leading cause of cancer death among both men and women, and low-LET radiation exposure increases human lung carcinogenesis, evaluating space radiation-induced lung tumorigenesis is critical to enable safe Mars missions. Here, by comparing lung tumorigenesis obtained from different mouse strains, as well as miR-21 in lung tissue/tumors and serum, we believe that wild type mice with a low spontaneous tumorigenesis background are ideal for evaluating the risk of space radiation-induced lung tumorigenesis, and circulating miR-21 from such mice model might be used as a biomarker for predicting the risk. Copyright © 2016 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

  4. Radiation induced effects in the developing central nervous system; Effectos radioinducidos sobre el sistema nervioso central en desarrollo

    Energy Technology Data Exchange (ETDEWEB)

    Gisone, P; Dubner, D; Michelin, S C; Perez, M.R. Del [Autoridad Regulatoria Nuclear, Gerencia de Apoyo Cientifico, Buenos Aires (Argentina)

    1997-11-01

    The embryo and the human foetus are particularly sensitive to ionizing radiation and this sensitivity presents various qualitative and quantitative functional changes during intra-uterine development. Apart from radiation induced carcinogenesis, the most serious consequence of prenatal exposure in human beings is severe mental retardation. The principal data on radiation effects on human beings in the development of the central nervous system come form epidemiological studies carried out in individuals exposed in utero during the atomic explosion at Hiroshima and Nagasaki. These observations demonstrate the existence of a time of maximum radiosensitivity between the weeks 8 and 15 of the gestational period, a period in which the proliferation and neuronal migration takes place. Determination of the characteristics of dose-response relationship and the possible existence of a threshold dose of radiation effects on the development of the central nervous system is relevant to radiation protection against low dose radiation and the establishment of dose limits for occupational exposure and the public. Studies were conducted on the generation of nitrous-oxide and its relation with the production of active species of oxygen in brains of exposed rats in utero exposed to doses of up to 1 Gy during their maximum radiosensitivity. The possible role of the mechanism of radiation induced damage in the development of the central nervous system is discussed. 8 refs.

  5. Effect of Sucralfate on Radiation-induced Esophageal Changes in Rat

    International Nuclear Information System (INIS)

    Kang, Ki Mun; Chai, Gyu Young; Yoon, Sei Chul

    2001-01-01

    The study was designed to evaluate the response of sucralfate against the esophageal damage of rat by irradiation. Sixty Sprague-Dawley rats weighing 200-250 gm were divided into six groups including only sucralfate group, the group of 10 Gy or 20 Gy radiation alone, the groups of 10 Gy or 20 Gy radiation-sucralfate combination, and control. Each group was sacrificed at 3, 7, 14 and 28 days after irradiation. For evaluation of the radiation-induced esophageal lesions, there were examined the change of body weight, barium-esophagogram and histopathologic findings. Mean body weight gain was decreased in the groups with 10 Gy or 20 Gy radiation alone and 10 Gy or 20 Gy radiation-sucralfate combination as comparing with control (p=0.03, p=0.02, p=0.04, p=0.02), but there was no difference between the groups of 10 Gy or 20 Gy radiation alone and the groups of 10 Gy or 20 Gy radiation-sucralfate combination. In the 20 Gy and 20 Gy radiation alone groups, barium esophagograms showed diffuse narrowing and stiffness through the entire esophagus from 7 days after irradiation, but there was similar pattern of esophagograms between the groups of 10 Gy radiation-sucralfate combination and the control. Histopathologic lesion scores of 10 Gy and 20 Gy radiation groups were significantly higher than the control (p=0.03, p=0.008). In the 10 Gy radiation group, there were significantly higher lesion scores ar 3 and 7 days after irradiation as comparing with those in the group of radiation-sucralfate combination (p=0.04, p=0.03). These results suggest that sucralfate might be played as a role of protection from acute radiation-induced esophagitis within the limit of tolerable radiation doses

  6. Effect of Sucralfate on Radiation-induced Esophageal Changes in Rat

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Ki Mun; Chai, Gyu Young [Gyeongsang National Univ., Jinju (Korea, Republic of); Yoon, Sei Chul [The Catholic Univ. of Korea, Seoul (Korea, Republic of)

    2001-12-15

    The study was designed to evaluate the response of sucralfate against the esophageal damage of rat by irradiation. Sixty Sprague-Dawley rats weighing 200-250 gm were divided into six groups including only sucralfate group, the group of 10 Gy or 20 Gy radiation alone, the groups of 10 Gy or 20 Gy radiation-sucralfate combination, and control. Each group was sacrificed at 3, 7, 14 and 28 days after irradiation. For evaluation of the radiation-induced esophageal lesions, there were examined the change of body weight, barium-esophagogram and histopathologic findings. Mean body weight gain was decreased in the groups with 10 Gy or 20 Gy radiation alone and 10 Gy or 20 Gy radiation-sucralfate combination as comparing with control (p=0.03, p=0.02, p=0.04, p=0.02), but there was no difference between the groups of 10 Gy or 20 Gy radiation alone and the groups of 10 Gy or 20 Gy radiation-sucralfate combination. In the 20 Gy and 20 Gy radiation alone groups, barium esophagograms showed diffuse narrowing and stiffness through the entire esophagus from 7 days after irradiation, but there was similar pattern of esophagograms between the groups of 10 Gy radiation-sucralfate combination and the control. Histopathologic lesion scores of 10 Gy and 20 Gy radiation groups were significantly higher than the control (p=0.03, p=0.008). In the 10 Gy radiation group, there were significantly higher lesion scores ar 3 and 7 days after irradiation as comparing with those in the group of radiation-sucralfate combination (p=0.04, p=0.03). These results suggest that sucralfate might be played as a role of protection from acute radiation-induced esophagitis within the limit of tolerable radiation doses.

  7. Radiation-induced cancer of the esophagus after postoperative irradiation for breast cancer

    International Nuclear Information System (INIS)

    Ito, Ichiro; Miyaishi, Kazuo; Mitsuhashi, Norio; Ito, Jun; Inoue, Tomio

    1978-01-01

    Two cases of radiation-induced cancer of the esophagus after postoperative irradiation for breast cancer were reported. Latent period of case 1 (cervical esophagus) was 12 years, and case 2 (middle thoracic esophagus) was 16 years. Radiographically the lesions were both serrated, and histologically, case 1 was ''poorly differentiated'' and case 2 was ''moderately differentiated'' squamous cell carcinoma. Histological types of basic breast cancer were both papillotubular carcinomas. Previous irradiation doses were 4180 rads for case 1 and 1860 rads for case 2. The esophageal cancers were remarkably improved by radiation therapy. It should be emphasized that radiation therapy is useful for the radiation-induced cancer of the esophagus. (author)

  8. Inter-chromosomal heterogeneity in the formation of radiation induced chromosomal aberrations

    International Nuclear Information System (INIS)

    Natarajan, A.T.; Vermeulen, S.; Boei, J.J.W.A.

    1997-01-01

    It is generally assumed that radiation induced chromosomal lesions are distributed randomly and repaired randomly among the genome. Recent studies using fluorescent in situ hybridization (FISH) and chromosome specific DNA libraries indicate that some chromosomes are more sensitive for radiation induced aberration formation than others. Chromosome No. 4 in human and chromosome No. 8 in Chinese hamster have been found to involve more in exchange aberrations than others, when calculated on the basis of their DNA content. Painting with arm specific chromosome libraries indicate that the frequencies of radiation induced intra-chromosome exchanges (i.e., between the arms of a chromosome, such as centric rings and inversions) are far in excess than one would expect on the basis of the frequencies of observed inter-chromosomal exchanges. The possible factors leading to the observed heterogeneity will be discussed

  9. Novel features of radiation-induced segregation and radiation-induced precipitation in austenitic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Z., E-mail: zjiao@umich.edu [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Was, G.S. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States)

    2011-02-15

    Three stainless steel alloys, high-purity 304 (HP304), high-purity 304 with high Si (HP304 + Si) and commercial purity 304 (CP304), were irradiated with 2 MeV protons to a dose of 5 dpa at 360 deg. C and subsequently examined using atom probe tomography (APT) and scanning transmission electron microscopy-energy dispersive X-ray spectrometry (STEM-EDS). Several novel features of radiation-induced segregation and radiation-induced precipitation were observed. There is a significant variation in the composition of enriched and depleted elements in the grain boundary plane and along the dislocation loop core. Boron segregation to the grain boundary prior to irradiation is not affected by the irradiation. Phosphorus segregation is enhanced by irradiation. Carbon depletes at the grain boundary and may be affected by co-segregation with Cr. APT and STEM-EDS measurements are in excellent agreement for almost all the elements studied. The segregation behavior of elements at dislocations mirrors that at the grain boundary, but at a lower magnitude, except for Si. Ni/Si-rich clusters formed in irradiated HP304 + Si and CP304 are probably the precursors of {gamma}' or other Si- and Ni-rich phases. Copper depletion was observed at both the grain boundary and the dislocation loops. Regions adjacent to the depleted zones were sites for Cu cluster formation, which were also spatially correlated with Ni/Si-rich clusters.

  10. R and D activities on radiation induced mutation breeding

    International Nuclear Information System (INIS)

    Lapade, A.G.; Asencion, A.B.; Santos, I.S.; Grafia, A.O.; Veluz, AM.S.; Barrida, A.C.; Marbella, L.J.

    1996-01-01

    This paper summarizes the accomplishments, prospects and future plans of mutation breeding for crop improvement at the Philippine Nuclear Research Institute (PNRI). Mutation induction has become a proven way creating variation within a crop variety and inducing desired attributes that cannot be found in nature or have been lost during evolution. Several improved varieties with desirable traits were successfully developed through induced mutation breeding at our research institute. In rice, mutation breeding has resulted in the development of new varieties: (1) PARC 2, (2) Milagrosa mutant, (3) Bengawan mutant and (4) Azmil mutant. Mutation breeding in leguminous crops has led to the induction of an improved L 114 soybean mutant that is shorter that the original variety but yield about 40% more. Several PAEC mungbean varieties characterized with long pods that are non-shattering were also induced. In asexually propagated crops, an increase in yield and chlorophyll mutants were obtained in sweet potatos. Likewise, chlorophyll mutant which look-like 'ornamental bromeliads' and a mutant with reduced spines have been developed in pineapple Queen variety. At present, we have started a new project in mutation breeding in ornamentals. Tissue culture is being utilized in our mutation breeding program. In the near future, radiation induced mutagenesis coupled with in vitro culture techniques on protoplast culture and somatic hybridization will be integrated into our mutation breeding program to facilitate the production of new crop varieties. (author)

  11. The isolation and improvement of Aspergillus niger by radiation for higher production of citric acid

    International Nuclear Information System (INIS)

    Radziah A; Foziah Ali; Zainab H

    2000-01-01

    Local citric acid producer of fungal strain Aspergillus niger have been successfully isolated from stale bread and onion. The isolates, designated as SB 1 and NN I showed a potential performance for citric acid production of 49% and 52% yield respectively, in shake flask studies. The strain improvement on NN1 was carried out by radiation induced mutation by gamma rays at LD 5 0 of 1.28 kGy

  12. Identification of radiation-induced hydrocarbons in halibut, cod and prawns by on-line coupled LC-GC/MS technique

    International Nuclear Information System (INIS)

    Spiegelberg, A.; Schulzki, G.; Boegl, K.W.; Schreiber, G.A.

    1997-01-01

    Radiation-induced hydrocarbons were analysed in a fatty (halibut) and a lean fish (cod) as well as in a prawn species by on-line coupled liquid chromatography (LC) - gas chromatography (GC) combined with mass spectrometrical detection. In irradiated halibut which contains mainly saturated and monounsaturated fatty acids all expected radiolytic alkanes, alkenes and alkadienes could be detected. The yields of the C n-1 and C n-2:1 hydrocarbons were comparable with those found in irradiated lipids of land animals and plants. However, in cod and the prawn species which contain high levels of polyunsaturated fatty acids (PUFA), the C n-1 hydrocarbons were found in concentrations up to tenfold higher whereas the C n-2:1 products were again comparable to those of land animals and plants. The identification of radiation-induced hydrocarbons in fish lipids was achieved by transfer of the hydrocarbons from the LC column to the gas chromatographic column in fractions differing in the degree of unsaturation. For the first time radiation induced hydrocarbons with more than four double bonds generated from polyunsaturated fatty acids (20:4ω6 and 20:5ω3) could be identified. (orig.) [de

  13. Radiation induced nano structures

    International Nuclear Information System (INIS)

    Ibragimova, E.M.; Kalanov, M.U.; Khakimov, Z.

    2006-01-01

    Full text: Nanometer-size silicon clusters have been attracting much attention due to their technological importance, in particular, as promising building blocks for nano electronic and nano photonic systems. Particularly, silicon wires are of great of interest since they have potential for use in one-dimensional quantum wire high-speed field effect transistors and light-emitting devices with extremely low power consumption. Carbon and metal nano structures are studied very intensely due to wide possible applications. Radiation material sciences have been dealing with sub-micron objects for a long time. Under interaction of high energy particles and ionizing radiation with solids by elastic and inelastic mechanisms, at first point defects are created, then they form clusters, column defects, disordered regions (amorphous colloids) and finally precipitates of another crystal phase in the matrix. Such irradiation induced evolution of structure defects and phase transformations was observed by X-diffraction techniques in dielectric crystals of quartz and corundum, which exist in and crystal modifications. If there is no polymorphism, like in alkali halide crystals, then due to radiolysis halogen atoms are evaporated from the surface that results in non-stoichiometry or accumulated in the pores formed by metal vacancies in the sub-surface layer. Nano-pores are created by intensive high energy particles irradiation at first chaotically and then they are ordered and in part filled by inert gas. It is well-known mechanism of radiation induced swelling and embrittlement of metals and alloys, which is undesirable for construction materials for nuclear reactors. Possible solution of this problem may come from nano-structured materials, where there is neither swelling nor embrittlement at gas absorption due to very low density of the structure, while strength keeps high. This review considers experimental observations of radiation induced nano-inclusions in insulating

  14. Search for the lowest irradiation dose from literatures on radiation-induced cancer in gastrointestinal tract

    Energy Technology Data Exchange (ETDEWEB)

    Yoshizawa, Y; Kusama, T [Tokyo Univ. (Japan). Faculty of Medicine

    1976-05-01

    A survey of past case reports about radiation-induced cancer in the gastrointestinal tract was carried out with the main object of finding the lowest irradiation dose. Search of the literature published since 1923 revealed 80 cases of radiation-induced large intestine cancer and one case of stomach cancer. The cases of radiation-induced cancer in the large intestine had received radiation for the treatment of non-malignant conditions, fibroma, ovarial cyste, myoma, endometritis and duodenal ulcer. The lowest irradiation dose was estimated at 460 rads. Adenocarcinoma was the histopathological finding in all cases of radiation-induced cancer in the caecum, colon and rectum, and squamous cell carcinoma in the cases of anal cancer. The latent period ranged from 1 to 31 years, with the average of 13.6 years. There were some reports of statistical studies of radiation-induced stomach cancer. Three groups were the subjects of these studies. The first group was composed of atomic bomb survivors, the second of patients who had undergone radiation treatment for ankylosing spondilitis, and the third of duodenal ulcer patients subjected to radiation treatment for the purpose of suppressing gastric acid secretion. These statistical studies showed no significant increase of the incidence of stomach cancer in the irradiated groups.

  15. Search for the lowest irradiation dose from literatures on radiation-induced cancer in gastrointestinal tract

    International Nuclear Information System (INIS)

    Yoshizawa, Yasuo; Kusama, Tomoko

    1976-01-01

    A survey of past case reports about radiation-induced cancer in the gastrointestinal tract was carried out with the main object of finding the lowest irradiation dose. Search of the literature published since 1923 revealed 80 cases of radiation-induced large intestine cancer and one case of stomach cancer. The cases of radiation-induced cancer in the large intestine had received radiation for the treatment of non-malignant conditions, fibroma, ovarial cyste, myoma, endometritis and duodenal ulcer. The lowest irradiation dose was estimated at 460 rads. Adenocarcinoma was the histopathological finding in all cases of radiation-induced cancer in the caecum, colon and rectum, and squamous cell carcinoma in the cases of anal cancer. The latent period ranged from 1 to 31 years, with the average of 13.6 years. There were some reports of statistical studies of radiation-induced stomach cancer. Three groups were the subjects of these studies. The first group was composed of atomic bomb survivors, the second of patients who had undergone radiation treatment for ankylosing spondilitis, and the third of duodenal ulcer patients subjected to radiation treatment for the purpose of suppressing gastric acid secretion. These statistical studies showed no significant increase of the incidence of stomach cancer in the irradiated groups. (auth.)

  16. Radiation induced destruction of thebaine, papaverine and noscapine in methanol

    International Nuclear Information System (INIS)

    Kantoğlu, Ömer; Ergun, Ece

    2016-01-01

    The presence of methanol decreases the efficiency of radiation-induced decomposition of alkaloids in wastewater. Intermediate products were observed before the complete degradation of irradiated alkaloids. In order to identify the structure of the by-products and the formation pathway, thebaine, papaverine and noscapine solutions were prepared in pure methanol and irradiated using a 60 Co gamma cell at absorbed doses of 0, 1, 3, 5, 7, 10, 30, 50 and 80 kGy. The dose-dependent alkaloid degradation and by-product formation were monitored by ESI mass spectrometer. Molecular structures of the by-products and reaction pathways were proposed. Oxygenated and methoxy group containing organic compounds was observed in the mass spectra of irradiated alkaloids. At initial dose values oxygenated by-products were formed due to the presence of dissolved oxygen in solutions. After the consumption of dissolved oxygen with radicals, the main mechanism was addition of solvent radicals to alkaloid structure. However, it was determined that alkaloids and by-products were completely degraded at doses higher than 50 kGy. The G-value and degradation efficiency of alkaloids were also evaluated. - Highlights: • Oxygenated and methoxy group containing by-products were observed in the mass spectra. • The addition of methanol radiolysis products to alkaloid structure was suggested. • Intermediate products were decomposed at doses above 50 kGy. • The destruction efficiency and degradation G-value of alkaloids were calculated.

  17. Radiation decontamination of meat lyophilized products

    International Nuclear Information System (INIS)

    Owczarczyk, H.B.; Migdal, W.

    2002-01-01

    There is an increasing demand for powder soups and sauces compose with lyophilized products. Technology of lyophilization is not always accompanied by thermal treatment of raw materials. That is the reason the products lyophilization process does not ensure as good microbiological quality as is required. Degree of microbiological decontamination and organoleptic properties of lyophilized meat were investigated after radiation treatment. (author)

  18. Radiation-induced processes in the metallic powders after electron and gamma-radiation

    International Nuclear Information System (INIS)

    Zajkin, Yu.A.; Aliev, B.A.

    2001-01-01

    In the work the quantitative assessments for conditions both healing and growth of micropores in metal volume and surface layers have been made. Taking into account of these rules is important at a choice of radiation processing conditions for fine-disperse powders characterizing with increased porosity. Numerical evaluation shows, that under irradiation of a metals by electrons with energy 2 MeV and electron current density about 1 μA/cm 2 within 300-400 K temperature range the optimal doses for the micropores healing make up a several Mrad. Further increase of dose could lead to formation of pores in the crystal volume. Principal conclusions about radiation porosity development character of metallic particles surface layers one can make from analysis of the point defects distribution near surface and computing of radiation-induced diffusion coefficients

  19. Radiation-induced augmentation of the immune response

    International Nuclear Information System (INIS)

    Anderson, R.E.; Lefkovits, I.; Troup, G.M.

    1980-01-01

    Radiation-induced augmentation of the immune response has been shown to occur both in vivo and in vitro. Evidence is presented to implicate injury to an extremely radiosensitive T cell in the expression of this phenomenon. Experiments are outlined which could be employed to support or reflect this hypothesis

  20. Sucralfate protects intestinal epithelial cells from radiation-induced apoptosis in rats

    International Nuclear Information System (INIS)

    Matsuu-Matsuyama, Mutsumi; Shichijo, Kazuko; Okaichi, Kumio

    2006-01-01

    Radiotherapy for malignant pelvic disease is often followed by acute radiation colitis (ARC). It has been reported that sucralfate treatment has a protective effect against ARC, though the mechanisms of action are unknown. The effects of sucralfate on X-ray radiation-induced apoptosis was studied at 4 Gy in the colonic crypt cells of rats. Sucralfate enemas given prior to radiation resulted in the following: reduction in number of apoptotic colonic crypt cells; reduction in number of caspase-3 positive cells; decreases in p53 accumulation and p21 expression; decreases of Bax/Bcl-2 ratio. The protective effects of sucralfate against ARC may be partially due to the suppression of radiation-induced apoptosis by way of p53 in the colon and the protection of the colonic epithelial stem cell region. (author)