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Sample records for radiation induced radicals

  1. Decay and microwave power saturation features to determine the radiation-induced radicals of sorbic acid and potassium sorbate

    Science.gov (United States)

    Tuner, Hasan

    2017-12-01

    Gamma irradiated sorbic acid (SA) and its potassium salt (KSA) were present complex unresolved Electron Paramagnetic Resonance (EPR) spectra. Spectroscopic features and possible structures of the radiation-induced radicals were determined using spectrum simulation calculations according to the microwave power saturations, room and high-temperatures decay findings. It is found that while the radicals decayed in time some of the radicals transferred to another type of radical. The spectrum simulations of SA and KSA were carried out on different spectra recorded in different conditions. Although, most of the radiation-induced radicals of SA and KSA have the similar chemical structures different EPR spectroscopic features were observed. It has been determined that there are three and four different radical species best describe the experimental spectra of SA and KSA, respectively. If the decay rates of the radiation-induced radicals are different, using the information derived from the decay findings present significant information about the spectroscopic features of the existing radicals.

  2. EPR spectral investigation of radiation-induced radicals of gallic acid

    Energy Technology Data Exchange (ETDEWEB)

    Tuner, Hasan [Balikesir University, Department of Physics, Faculty of Art and Science, Balikesir (Turkey)

    2017-11-15

    In the present work, spectroscopic features of the radiation-induced radicals of gallic acid compounds were investigated using electron paramagnetic resonance (EPR) spectroscopy. While un-irradiated samples presented no EPR signal, irradiated samples exhibited an EPR spectrum consisting of an intense resonance line at the center and weak lines on both sides. Detailed microwave saturation investigations were carried out to determine the origin of the experimental EPR lines. It is concluded that the two side lines of the triplet satellite originate from forbidden ''spin-flip'' transitions. The spectroscopic and structural features of the radiation-induced radicals were determined using EPR spectrum fittings. The experimental EPR spectra of the two gallic acid compounds were consistent with the calculated EPR spectroscopic features of the proposed radicals. It is concluded that the most probable radicals are the cyclohexadienyl-type, O(OH){sub 2}C{sub 6}H{sub 2}COOH radicals for both compounds. (orig.)

  3. Ultraviolet radiation and nanoparticle induced intracellular free radicals generation measured in human keratinocytes by electron paramagnetic resonance spectroscopy.

    Science.gov (United States)

    Rancan, F; Nazemi, B; Rautenberg, S; Ryll, M; Hadam, S; Gao, Q; Hackbarth, S; Haag, S F; Graf, C; Rühl, E; Blume-Peytavi, U; Lademann, J; Vogt, A; Meinke, M C

    2014-05-01

    Several nanoparticle-based formulations used in cosmetics and dermatology are exposed to sunlight once applied to the skin. Therefore, it is important to study possible synergistic effects of nanoparticles and ultraviolet radiation. Electron paramagnetic resonance spectroscopy (EPR) was used to detect intracellular free radicals induced by ultraviolet B (UVB) radiation and amorphous silica nanoparticle and to evaluate the influence of nanoparticle surface chemistry on particle cytotoxicity toward HaCaT cells. Uncoated titanium dioxide nanoparticles served as positive control. In addition, particle intracellular uptake, viability, and induction of interleukin-6 were measured. We found that photo-activated titanium dioxide particles induced a significant amount of intracellular free radicals. On the contrary, no intracellular free radicals were generated by the investigated silica nanoparticles in the dark as well as under UVB radiation. However, under UVB exposure, the non-functionalized silica nanoparticles altered the release of IL-6. At the same concentrations, the amino-functionalized silica nanoparticles had no influence on UVB-induced IL-6 release. EPR spectroscopy is a useful technique to measure nanoparticle-induced intracellular free radicals. Non-toxic concentrations of silica particles enhanced the toxicity of UVB radiation. This synergistic effect was not mediated by particle-generated free radicals and correlated with particle surface charge and intracellular distribution. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Comparison of free radicals formation induced by cold atmospheric plasma, ultrasound, and ionizing radiation.

    Science.gov (United States)

    Rehman, Mati Ur; Jawaid, Paras; Uchiyama, Hidefumi; Kondo, Takashi

    2016-09-01

    Plasma medicine is increasingly recognized interdisciplinary field combining engineering, physics, biochemistry and life sciences. Plasma is classified into two categories based on the temperature applied, namely "thermal" and "non-thermal" (i.e., cold atmospheric plasma). Non-thermal or cold atmospheric plasma (CAP) is produced by applying high voltage electric field at low pressures and power. The chemical effects of cold atmospheric plasma in aqueous solution are attributed to high voltage discharge and gas flow, which is transported rapidly on the liquid surface. The argon-cold atmospheric plasma (Ar-CAP) induces efficient reactive oxygen species (ROS) in aqueous solutions without thermal decomposition. Their formation has been confirmed by electron paramagnetic resonance (EPR) spin trapping, which is reviewed here. The similarities and differences between the plasma chemistry, sonochemistry, and radiation chemistry are explained. Further, the evidence for free radical formation in the liquid phase and their role in the biological effects induced by cold atmospheric plasma, ultrasound and ionizing radiation are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Preventive efficacy of hydroalcoholic extract of Cymbopogon citratus against radiation-induced DNA damage on V79 cells and free radical scavenging ability against radicals generated in vitro.

    Science.gov (United States)

    Rao, B S S; Shanbhoge, R; Rao, B N; Adiga, S K; Upadhya, D; Aithal, B K; Kumar, M R S

    2009-04-01

    This study presents the findings of free radical scavenging and antigenotoxic effect of hydroalcoholic extract of Cymbopogon citratus (CCE). The CCE at a concentration of 60 microg/mL resulted in a significant scavenging ability of 2,2-diphenyl-2-picryl hydrazyl (DPPH; (85%), 2,2-azinobis (3-ethyl benzothiazoline-6-sulphonic acid) (ABTS; 77%), hydroxyl (70%), superoxide (76%), nitric oxide (78%) free radicals generated using in vitro and also a moderate anti-lipid peroxidative effect (57%). Further, the radiation-induced antigenotoxic potential of CCE was assessed in Chinese hamster lung fibroblast cells (V79) using micronucleus assay. The CCE resulted in a dose-dependent decrease in the yield of radiation-induced micronuclei, with a maximum effect at 125 microg/mL CCE for 1 h before 2 Gy of radiation. Similarly, there was a significant (P < 0.05-0.0001) decrease in percentage of micronuclei when V79 cells were treated with optimal dose of CCE (125 microg/mL) before exposure to different doses of gamma radiation, that is, 0.5-4 Gy, compared with radiation alone groups. The results of the micronucleus study indicated antigenotoxic effect demonstrating the radioprotective potential of CCE and, which may partly due to its and antioxidant capacity as it presented its ability to scavenge various free radicals in vitro and anti-lipid peroxidative potential.

  6. Arbutin, an intracellular hydroxyl radical scavenger, protects radiation-induced apoptosis in human lymphoma U937 cells.

    Science.gov (United States)

    Wu, Li-Hua; Li, Peng; Zhao, Qing-Li; Piao, Jin-Lan; Jiao, Yu-Fei; Kadowaki, Makoto; Kondo, Takashi

    2014-11-01

    Ionizing radiation (IR) can generate reactive oxygen species (ROS). Excessive ROS have the potential to damage cellular macromolecules including DNA, proteins, and lipids and eventually lead to cell death. In this study, we evaluated the potential of arbutin, a drug chosen from a series of traditional herbal medicine by measuring intracellular hydroxyl radical scavenging ability in X-irradiated U937 cells. Arbutin (hydroquinone-β-D-glucopyranoside), a naturally occurring glucoside of hydroquinone, has been traditionally used to treat pigmentary disorders. However, there are no reports describing the effect of arbutin on IR-induced apoptosis. We confirmed that arbutin can protect cells from apoptosis induced by X-irradiation. The combination of arbutin and X-irradiation could reduce intracellular hydroxyl radical production and prevent mitochondrial membrane potential loss. It also could down-regulate the expression of phospho-JNK, phospho-p38 in whole cell lysate and activate Bax in mitochondria. Arbutin also inhibits cytochrome C release from mitochondria to cytosol. To verify the role of JNK in X-irradiation-induced apoptosis, the cells were pretreated with a JNK inhibitor, and found that JNK inhibitor could reduce apoptosis induced by X-irradiation. Taken together, our data indicate that arbutin plays an anti-apoptotic role via decreasing intracellular hydroxyl radical production, inhibition of Bax-mitochondria pathway and activation of the JNK/p38 MAPK pathway.

  7. Triphala, an ayurvedic rasayana drug, protects mice against radiation-induced lethality by free-radical scavenging.

    Science.gov (United States)

    Jagetia, Ganesh Chandra; Malagi, Krishna J; Baliga, Manjeshwar Shrinath; Venkatesh, Ponemone; Veruva, Rosi Reddy

    2004-12-01

    The effects of 10 mg/kg of triphala extract (TE) was studied on radiation-induced sickness and mortality in mice exposed to 7-12 Gray (Gy) of gamma-irradiation. Treatment of mice with triphala once daily for 5 consecutive days before irradiation delayed the onset of mortality and reduced the symptoms of radiation sickness when compared with the non-drug double distilled water treated irradiated controls (DDW). Triphala provided protection against both gastrointestinal and hemopoetic death. However, animals of both the TE + irradiation and DDW + irradiation groups did not survive up to 30 days post-irradiation beyond 11 Gy irradiation. The LD50/30 was found to be 8.6 Gy for the DDW + irradiation group and 9.9 Gy for TE + irradiation group. The administration of triphala resulted in an increase in the radiation tolerance by 1.4 Gy, and the dose reduction factor was found to be 1.15. To understand the mechanism of action of triphala, the free radical scavenging activity of the drug was evaluated. Triphala was found to scavenge (.)OH, O(2) (.) 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonate) diammonium salt (ABTS)(.+) and NO(.) radicals in a dose dependent manner.

  8. Radiation-induced polymerisation of 2,3-dihydrofuran: free-radical or cationic mechanism?

    Science.gov (United States)

    Janovský, Igor; Naumov, Sergej; Knolle, Wolfgang; Mehnert, Reiner

    2005-02-01

    Concentrated (10 mol%) solutions of 2,3-dihydrofuran in CFCl 2CF 2Cl matrix were irradiated at 77 K and several intermediates (dimer radical cation, dihydrofuryl radical, and polymer radicals) were observed by low-temperature EPR spectroscopy. The irradiated solutions yielded after melting a polymeric product, which was characterised by IR spectroscopy and gel permeation chromatography. The polydisperse polymer is assumed to be formed mainly by a cationic process initiated by a dimer carbocation. The free-radical mechanism via the dihydrofuryl radical leads to low molecular weight oligomers only. Quantum chemical calculations support the interpretation of the experimental results.

  9. Synchrotron radiation structure analyses of the light-induced radical pair of a hexaarylbiimidazolyl derivative. Origin of the spin-multiplicity change

    CERN Document Server

    Kawano, M; Matsubara, K; Imabayashi, H; Mitsumi, M; Toriumi, K; Ohashi, Y

    2002-01-01

    In situ synchrotron radiation structure analyses of a light-induced radical pair from o-Cl-HABI were performed by using an X-ray vacuum camera at 23-70K at the BL02B1 station of SPring-8. The combined results of X-ray analysis with theoretical calculation, IR, and UV-vis spectroscopy reveal that a slight conformational change of the radical pair causes the drastic spin-multiplicity change during 2-140K. (author)

  10. Matrix-isolation studies on the radiation-induced chemistry in H₂O/CO₂ systems: reactions of oxygen atoms and formation of HOCO radical.

    Science.gov (United States)

    Ryazantsev, Sergey V; Feldman, Vladimir I

    2015-03-19

    The radiation-induced transformations occurring upon X-ray irradiation of solid CO2/H2O/Ng systems (Ng = Ar, Kr, Xe) at 8-10 K and subsequent annealing up to 45 K were studied by Fourier transform infrared spectroscopy. The infrared (IR) spectra of deposited matrices revealed the presence of isolated monomers, dimers, and intermolecular H2O···CO2 complexes. Irradiation resulted in effective decomposition of matrix-isolated carbon dioxide and water yielding CO molecules and OH radicals, respectively. Annealing of the irradiated samples led to formation of O3, HO2, and a number of xenon hydrides of HXeY type (in the case of xenon matrices). The formation of these species was used for monitoring of the postirradiation thermally induced chemical reactions involving O and H atoms generated by radiolysis. It was shown that the radiolysis of CO2 in noble-gas matrices produced high yields of stabilized oxygen atoms. In all cases, the temperatures at which O atoms become mobile and react are lower than those of H atoms. Dynamics and reactivity of oxygen atoms was found to be independent of the precursor nature. In addition, the formation of HOCO radicals was observed in all the noble-gas matrices at remarkably low temperatures. The IR spectra of HOCO and DOCO were first characterized in krypton and xenon matrices. It was concluded that the formation of HOCO was mainly due to the radiation-induced evolution of the weakly bound H2O···CO2 complexes. This result indicates the significance of weak intermolecular interactions in the radiation-induced chemical processes in inert low-temperature media.

  11. Oxidative stress and enzymatic scavenging of superoxide radicals induced by solar UV-B radiation in Ulva canopies from southern Spain

    Directory of Open Access Journals (Sweden)

    Kai Bischof

    2003-09-01

    Full Text Available The generation of reactive oxygen species (ROS and scavenging of the superoxide radical by superoxide dismutase (SOD was studied in mat-like canopies of the green macroalga Ulva rotundata Bliding in a tidal brine pond system in southern Spain. Artificial canopies were covered with different cut-off filters, generating different radiation conditions. ROS and SOD were assessed after three days of exposure. ROS induced lipid peroxidation depended on the position of individual thalli within the canopy and on radiation conditions. Samples exposed to the full solar spectrum were most affected, whereas samples either exposed to photosynthetically active radiation (PAR alone or UV radiation without PAR exhibited fewer peroxidation products. The activity of SOD appeared to be controlled by the impinging UV-A and UV-B radiation and also increased in response to oxidative stress. The results provide evidence for additive effects of high PAR and UV-B under field conditions and support the previously proposed hypothesis that UV-B effects are mediated by an inhibition of the xanthophyll cycle, which increases ROS production and, consequently, causes oxidative damage to components of the photosynthetic machinery, such as proteins and pigments.

  12. Radiation-induced radicals in different polymorphic modifications of D-mannitol: Structure, conformations and dosimetric implications

    Science.gov (United States)

    Sosulin, Ilya S.; Shiryaeva, Ekaterina S.; Feldman, Vladimir I.

    2015-12-01

    The structure and conformation of radicals produced by X-ray irradiation of three polymorphic forms of D-mannitol were investigated using EPR spectroscopy. In all the cases, primary species were identified as radicals resulting from hydrogen abstraction from position 3 or 4 of the mannitol molecule. It was found that molecular packing in crystals of different polymorphic modifications had noticeable effect on the conformation of radicals observed after irradiation at room temperature and the dehydration of the primary radicals occurring at 400 K. The radicals trapped in stable modifications (β- and δ-forms) were found to be very stable at room temperature. Relatively high radical yields and remarkable stability of radicals suggest that D-mannitol can be used as an EPR dosimeter or irradiation marker.

  13. Lipid peroxidation induced by phenylbutazone radicals.

    Science.gov (United States)

    Miura, Toshiaki; Muraoka, Sanae; Fujimoto, Yukio

    2002-04-19

    Lipid peroxidation was investigated to evaluate the deleterious effect on tissues by phenylbutazone (PB). PB induced lipid peroxidation of microsomes in the presence of horseradish peroxidase and hydrogen peroxide (HRP-H2O2). The lipid peroxidation was completely inhibited by catalase but not by superoxide dismutase. Mannitol and dimethylsulfoxide had no effect. These results indicated no paticipation of superoxide and hydroxyl radical in the lipid peroxidation. Reduced glutathione (GSH) efficiently inhibited the lipid peroxidation. PB radicals emitted electron spin resonance (ESR) signals during the reaction of PB with HRP-H2O2. Microsomes and arachidonic acid strongly diminished the ESR signals, indicating that PB radicals directly react with unsaturated lipids of microsomes to cause thiobarbituric acid reactive substances. GSH sharply diminished the ESR signals of PB radicals, suggesting that GSH scavenges PB radicals to inhibit lipid peroxidation. Also, 2-methyl-2-nitrosopropan strongly inhibited lipid peroxidation. R-Phycoerythrin, a peroxyl radical detector substance, was decomposed by PB with HRP-H2O2. These results suggest that lipid peroxidation of microsomes is induced by PB radicals or peroxyl radicals, or both.

  14. Study on radiation-induced radicals giving rise to stable EPR signal suitable for the detection of irradiation in L-sorbose-containing fruits

    Directory of Open Access Journals (Sweden)

    Guzik Grzegorz P.

    2016-12-01

    Full Text Available The stable and complex EPR signals produced by the action of ionizing radiation on crystalline L-sorbose (C6H12O6 separated from rowan berries (Sorbus aucuparia were studied. Isothermal heating of the samples at the temperature close to the melting point of L-sorbose (140°C results in the modification and simplification of the EPR signal involved. In the EPR signal of heated L-sorbose, the isotropic quartet was distinguished. In the differential spectrum obtained by subtraction of normalized spectra of unheated and heated L-sorbose, the isotropic doublet was identified in addition. The DFT fitting offers the probable assignment of the EPR signals to specific radical structures.

  15. Radiation-induced leiomyosarcoma of the oropharynx

    Directory of Open Access Journals (Sweden)

    Maier Wolfgang

    2006-08-01

    Full Text Available Abstract Leiomyosarcoma is a malignant mesenchymal tumor originating from smooth muscle cells, which most frequently develops in the myometrium and in the gastro-intestinal tract. Reviewing the international literature, radiation-induced sarcoma arise in 0.035 to 0.2 % of all irradiated patients. Especially in the head and neck region, radiation-induced leiomyosarcoma is an extremely rare lesion. The authors report a case of a radiation-induced leiomyosarcoma of the tonsillar region of the oropharynx in a 51-year-old male patient, who had undergone radiation therapy of this region 38 years before. The lesion was treated by radical surgery. Diagnostic steps, histological presentation and therapy are described in detail and the literature concerning radiation induced malignancies in general as well as radiation induced leiomyosarcoma in particular is reviewed. The highlights of this case are an extremely uncommon location and a rare pathological entity of radiation induced malignancies.

  16. Characterization of 60 Co y-radiation induced radical products of antipyrine by means of high performance liquid chromatography, mass spectrometry, capillary zone electrophoresis, micellar electrokinetic capillary chromatography and nuclear magnetic resonance spectrometry

    NARCIS (Netherlands)

    Coolen, S.A.J.; Everaerts, F.M.; Huf, F.A.

    1997-01-01

    Monitoring the amount of oxidative damage, caused by free radicals, is a major problem in free radical and aging research. Antipyrine is proposed as an exogenous marker for the biomolecular monitoring of oxidative stress. In this paper the characterization of the 60Co γ-radiation products of

  17. Direct observation of elementary radical events: low- and high-energy radiation femtochemistry in solutions

    Energy Technology Data Exchange (ETDEWEB)

    Brozek-Pluska, Beata [Institute of Applied Radiation Chemistry, Technical University of Lodz, 15 Wroblewskiego Street, 93-590 Lodz (Poland); Gliger, David; Hallou, Abdeslem [Laboratoire d' Optique Appliquee, CNRS UMR 7639, Ecole Polytechnique-ENS Techniques Avancees, 91761 Palaiseau Cedex (France); Malka, Victor; Gauduel, Yann A. [Laboratoire d' Optique Appliquee, CNRS UMR 7639, Ecole Polytechnique-ENS Techniques Avancees, 91761 Palaiseau Cedex (France)]. E-mail: yann.gauduel@ensta.fr

    2005-02-01

    The fundamental importance of understanding the primary effects of ionizing radiations in liquid phase and solutions is emphasized in fields such as electron transfer reactions, radical chemistry and radiobiology. With the advent of ultrashort optical pulses and powerful laser systems (TW lasers), ultrafast spectroscopic investigations might conjecture the direct observation of primary events induced by low-energy (photons) and high-energy (relativistic electrons) radiations. The different points discussed in this paper concern the investigation of short-time solvent caging effects on elementary radical reactions in homogeneous liquid phase and nascent spurs.

  18. Detecting free radicals in sunscreens exposed to UVA radiation using chemiluminescence.

    Science.gov (United States)

    Millington, Keith R; Osmond, Megan J; McCall, Maxine J

    2014-04-05

    One of the current concerns with the application of nanoparticles in sunscreens, and in particular nano-TiO2 and ZnO, is their potential to photogenerate free radicals and reactive oxygen species (ROS) when they absorb ultraviolet wavelengths from sunlight. Free radicals and ROS are known to be associated with UV-induced skin damage and oxidative stress, from which sunscreens are expected to offer significant protection. Here we describe a simple method, based on chemiluminescence emission, for detecting free radicals generated in commercial sunscreens alone, and when applied to various substrates, following exposure to UVA (320-400nm) radiation. This photo-induced chemiluminescence (PICL) technique could be used to optimise sunscreen formulations so as to minimise free radical photogeneration during exposure to sunlight. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  19. Resonance Raman Spectroscopy of Free Radicals Produced by Ionizing Radiation

    DEFF Research Database (Denmark)

    Wilbrandt, Robert Walter

    1984-01-01

    Applications of time-resolved resonance Raman spectroscopy to the study of short-lived free radicals produced by ionizing radiation are briefly reviewed. Potential advantages and limitations of this technique are discussed in the light of given examples. The reduction of p-nitrobenzylchloride and......Applications of time-resolved resonance Raman spectroscopy to the study of short-lived free radicals produced by ionizing radiation are briefly reviewed. Potential advantages and limitations of this technique are discussed in the light of given examples. The reduction of p......-nitrobenzylchloride and subsequent formation of the p-nitrobenzyl radical and the reaction of p-nitrotoluene with O– are studied by resonance Raman and optical absorption spectroscopy....

  20. Hydroxyl radical induced degradation of salicylates in aerated aqueous solution

    Science.gov (United States)

    Szabó, László; Tóth, Tünde; Homlok, Renáta; Rácz, Gergely; Takács, Erzsébet; Wojnárovits, László

    2014-04-01

    Ionizing radiation induced degradation of acetylsalicylic acid, its hydrolysis product salicylic acid and a salicylic acid derivative 5-sulpho-salicylic acid, was investigated in dilute aqueous solutions by UV-vis spectrophotometry, HPLC separation and diode-array or MS/MS detection, chemical oxygen demand, total organic carbon content and by Vibrio fischeri toxicity measurements. Hydroxyl radicals were shown to degrade these molecules readily, and first degradation products were hydroxylated derivatives in all cases. Due to the by-products, among them hydrogen peroxide, the toxicity first increased and then decreased with the absorbed dose. With prolonged irradiation complete mineralization was achieved.

  1. Chemical and radiation-chemical radical reactions in lignocellulose materials

    Science.gov (United States)

    Kuzina, Svetlana I.; Shilova, Irina A.; Mikhailov, Al'fa I.

    2011-09-01

    Chemical and radiation-chemical radical reactions in lignocellulose materials were explored by 3-cm and 2-mm ESR spectroscopy. Background (intrinsic) singlet signals at g=2.003 from wood pulp and lignin and those arising during reaction of lignocellulose materials with acids and chlorine were attributed to radicals with conjugated CC bonds. The 2-mm ESR signal with 3D anisotropy of g-factor from o-semiquinone radical ions formed in reaction of lignin with NaOH was recorded for the first time. The singlet signals derived from cellulose γ-irradiated at 77 K and marked out during post-thermal reactions were assigned to radicals with conjugated bonds. In wetted cellulose, a triplet signal with αβH≅2.7 mT and imposed quadruplet structure (0.5-0.7 mT) from three γ-protons was detected at 300 K and attributed to С 4-radicals. The triplet signals derived from С 2- and С 3-radicals in pyranose cycles of cellulose exhibited higher values of αβH (3.0-3.2 mT) and lower thermal stability (up to 250 K). In radiolyzed cotton pulp, detected were ESR signals derived from formyl radicals formed upon rupture of the С 5С 6 bond in pyranose cycles. Heating up irradiated samples under О 2 was accompanied by formation of peroxide radicals. Photoinduced recombination of trapped electrons with С 1-radicals was found to proceed as a chain reaction with a kinetic length of about 25 units. Photolysis ( λ≥360 nm) of radiolyzed cellulose enhanced the disclosure of pyranose cycles and, as a result, the evolution of CO 2 by a factor of 2-2.5.

  2. Free Radicals Generated by Ionizing Radiation Signal Nuclear Translocation of p53

    Science.gov (United States)

    Martinez, J. D.; Pennington, M. E.; Craven, M. T.; Warters, R. L.

    1997-01-01

    The p53 tumor suppressor is a transcription factor that regulates several pathways, which function collectively to maintain the integrity of the genome. Nuclear localization is critical for wild-type function. However, the signals that regulate subcellular localization of p53 have not been identified. Here, we examine the effect of ionizing radiation on the subcellular localization of p53 in two cell lines in which p63 is normally sequestered in the cytoplasm and found that ionizing radiation caused a biphasic translocation response. p53 entered the nucleus 1-2 hours postirradiation (early response), subsequently emerged from the nucleus, and then again entered the nucleus 12-24 hours after the cells had been irradiated (delayed response). These changes in subcellular localization could be completely blocked by the free radical scavenger, WR1065. By comparison, two DNA-damaging agents that do not generate free radicals, mitomycin C and doxorubicin, caused translocation only after 12-24 h of exposure to the drugs, and this effect could not be inhibited by WR1065. Hence, although all three DNA-damaging agents induced relocalization of p53 to the nucleus, only the translocation caused by radiation was sensitive to free radical scavenging. We suggest that the free radicals generated by ionizing radiation can signal p53 translocation to the nucleus.

  3. The effect of near-infrared MLS laser radiation on cell membrane structure and radical generation.

    Science.gov (United States)

    Kujawa, Jolanta; Pasternak, Kamila; Zavodnik, Ilya; Irzmański, Robert; Wróbel, Dominika; Bryszewska, Maria

    2014-09-01

    The therapeutic effects of low-power laser radiation of different wavelengths and light doses are well known, but the biochemical mechanism of the interaction of laser light with living cells is not fully understood. We have investigated the effect of MLS (Multiwave Locked System) laser near-infrared irradiation on cell membrane structure, functional properties, and free radical generation using human red blood cells and breast cancer MCF-4 cells. The cells were irradiated with low-intensity MLS near-infrared (simultaneously 808 nm, continuous emission and 905 nm, pulse emission, pulse-wave frequency, 1,000 or 2,000 Hz) laser light at light doses from 0 to 15 J (average power density 212.5 mW/cm(2), spot size was 3.18 cm(2)) at 22 °C, the activity membrane bound acetylcholinesterase, cell stability, anti-oxidative activity, and free radical generation were the parameters used in characterizing the structural and functional changes of the cell. Near-infrared low-intensity laser radiation changed the acetylcholinesterase activity of the red blood cell membrane in a dose-dependent manner: There was a considerable increase of maximal enzymatic rate and Michaelis constant due to changes in the membrane structure. Integral parameters such as erythrocyte stability, membrane lipid peroxidation, or methemoglobin levels remained unchanged. Anti-oxidative capacity of the red blood cells increased after MLS laser irradiation. This irradiation induced a time-dependent increase in free radical generation in MCF-4 cells. Low-intensity near-infrared MLS laser radiation induces free radical generation and changes enzymatic and anti-oxidative activities of cellular components. Free radical generation may be the mechanism of the biomodulative effect of laser radiation.

  4. Obtention of zinc polymethacrylate via free radicals induced by gamma radiation; Obtencion del polimetacrilato de zinc via radicales libres inducidos por radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Urena N, F.; Flores E, J. [Departamento de Fisica, Instituto Nacional de Investigaciones Nucleares, C.P. 52045 Estado de Mexico (Mexico)

    2000-07-01

    The objective of this work was to synthesise the monomer of zinc methacrylate and subsequently to carry out the polymerization reaction with the purpose to obtain the compound desired, the zinc polymethacrylate. For this it was used a gamma radiation source, {sup 60} Co, as initiator of the polymerization reaction. (Author)

  5. Studying mechanism of radical reactions: From radiation to nitroxides as research tools

    Science.gov (United States)

    Maimon, Eric; Samuni, Uri; Goldstein, Sara

    2018-02-01

    Radicals are part of the chemistry of life, and ionizing radiation chemistry serves as an indispensable research tool for elucidation of the mechanism(s) underlying their reactions. The ever-increasing understanding of their involvement in diverse physiological and pathological processes has expanded the search for compounds that can diminish radical-induced damage. This review surveys the areas of research focusing on radical reactions and particularly with stable cyclic nitroxide radicals, which demonstrate unique antioxidative activities. Unlike common antioxidants that are progressively depleted under oxidative stress and yield secondary radicals, nitroxides are efficient radical scavengers yielding in most cases their respective oxoammonium cations, which are readily reduced back in the tissue to the nitroxide thus continuously being recycled. Nitroxides, which not only protect enzymes, cells, and laboratory animals from diverse kinds of biological injury, but also modify the catalytic activity of heme enzymes, could be utilized in chemical and biological systems serving as a research tool for elucidating mechanisms underlying complex chemical and biochemical processes.

  6. 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

  7. 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.

  8. Free radical scavenging alleviates the biomechanical impairment of gamma radiation sterilized bone tissue.

    Science.gov (United States)

    Akkus, Ozan; Belaney, Ryan M; Das, Prasenjit

    2005-07-01

    Terminal sterilization of bone allografts by gamma radiation is often essential prior to their clinical use to minimize the risk of infection and disease transmission. While gamma radiation has efficacy superior to other sterilization methods it also impairs the material properties of bone allografts, which may result in premature clinical failure of the allograft. The mechanisms by which gamma radiation sterilization damages bone tissue are not well known although there is evidence that the damage is induced via free radical attack on the collagen. In the light of the existing literature, it was hypothesized that gamma radiation induced biochemical damage to bone's collagen that can be reduced by scavenging for the free radicals generated during the ionizing radiation. It was also hypothesized that this lessening of the extent of biochemical degradation of collagen will be accompanied by alleviation in the extent of biomechanical impairment secondary to gamma radiation sterilization. Standardized tensile test specimens machined from human femoral cortical bone and specimens were assigned to four treatment groups: control, scavenger treated-control, irradiated and scavenger treated-irradiated. Thiourea was selected as the free radical scavenger and it was applied in aqueous form at the concentration of 1.5 M. Monotonic and cyclic mechanical tests were conducted to evaluate the mechanical performance of the treatment groups and the biochemical integrity of collagen molecules were assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The native mechanical properties of bone tissue did not change by thiourea treatment only. The effect of thiourea treatment on mechanical properties of irradiated specimens were such that the post-yield energy, the fracture energy and the fatigue life of thiourea treated-irradiated treatment group were 1.9-fold, 3.3-fold and 4.7-fold greater than those of the irradiated treatment group, respectively. However, the

  9. Radiation Induced Genomic Instability

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, William F.

    2011-03-01

    Radiation induced genomic instability can be observed in the progeny of irradiated cells multiple generations after irradiation of parental cells. The phenotype is well established both in vivo (Morgan 2003) and in vitro (Morgan 2003), and may be critical in radiation carcinogenesis (Little 2000, Huang et al. 2003). Instability can be induced by both the deposition of energy in irradiated cells as well as by signals transmitted by irradiated (targeted) cells to non-irradiated (non-targeted) cells (Kadhim et al. 1992, Lorimore et al. 1998). Thus both targeted and non-targeted cells can pass on the legacy of radiation to their progeny. However the radiation induced events and cellular processes that respond to both targeted and non-targeted radiation effects that lead to the unstable phenotype remain elusive. The cell system we have used to study radiation induced genomic instability utilizes human hamster GM10115 cells. These cells have a single copy of human chromosome 4 in a background of hamster chromosomes. Instability is evaluated in the clonal progeny of irradiated cells and a clone is considered unstable if it contains three or more metaphase sub-populations involving unique rearrangements of the human chromosome (Marder and Morgan 1993). Many of these unstable clones have been maintained in culture for many years and have been extensively characterized. As initially described by Clutton et al., (Clutton et al. 1996) many of our unstable clones exhibit persistently elevated levels of reactive oxygen species (Limoli et al. 2003), which appear to be due dysfunctional mitochondria (Kim et al. 2006, Kim et al. 2006). Interestingly, but perhaps not surprisingly, our unstable clones do not demonstrate a “mutator phenotype” (Limoli et al. 1997), but they do continue to rearrange their genomes for many years. The limiting factor with this system is the target – the human chromosome. While some clones demonstrate amplification of this chromosome and thus lend

  10. Radiation induced microbial pesticide

    Energy Technology Data Exchange (ETDEWEB)

    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)

  11. Nitroxyl radicals remarkably enhanced the superoxide anion radical-induced chemiluminescence of Cypridina luciferin analogues.

    Science.gov (United States)

    Takeshita, Keizo; Okazaki, Shoko; Itoda, Akiko

    2013-07-16

    Measuring the superoxide anion radical (superoxide) with high sensitivity is necessary to clarify the mechanisms of diseases for the development of methods for their prophylaxes, diagnoses, and therapies. The chemiluminescence technique using Cypridina luciferin analogues such as MCLA and CLA is currently the most sensitive method available. Using large concentrations of these reagents, however, leads to increases in background levels due to spontaneous luminescence of the reagent, which is a limitation of this method. This study demonstrated that the superoxide-induced chemiluminescence of MCLA or CLA was markedly enhanced by adding a cyclic nitroxyl radical to the reaction medium. When MCLA was measured spectrophotometrically, the nitroxyl radical was shown to increase the reaction rate of superoxide and MCLA without altering their stoichiometry, whereas consumption of the nitroxyl radical was negligible, as determined by electron paramagnetic resonance (EPR) spectroscopy. These observations indicate that the nitroxyl radical catalytically enhanced the reaction between superoxide and MCLA, resulting in an enhancement in superoxide-dependent MCLA chemiluminescence. This method is applicable to biological systems such as superoxide-generation by neutrophils. The inclusion of the cyclic nitroxyl radical in a sample solution contributed to reductions in the concentration of the chemiluminescence reagent, thereby decreasing background levels. The catalytic mechanism was also discussed.

  12. Hydroxyl radical induced degradation of ibuprofen

    Energy Technology Data Exchange (ETDEWEB)

    Illés, Erzsébet, E-mail: erzsebet.illes@chem.u-szeged.hu [Institute of Chemistry, Research Group of Environmental Chemistry, University of Szeged, Szeged (Hungary); Institute of Isotopes, Centre for Energy Research, Hungarian Academy of Sciences, Budapest (Hungary); Takács, Erzsébet [Institute of Isotopes, Centre for Energy Research, Hungarian Academy of Sciences, Budapest (Hungary); Dombi, András [Institute of Chemistry, Research Group of Environmental Chemistry, University of Szeged, Szeged (Hungary); Gajda-Schrantz, Krisztina [Institute of Chemistry, Research Group of Environmental Chemistry, University of Szeged, Szeged (Hungary); Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged (Hungary); EMPA, Laboratory for High Performance Ceramics, Duebendorf (Switzerland); Rácz, Gergely; Gonter, Katalin; Wojnárovits, László [Institute of Isotopes, Centre for Energy Research, Hungarian Academy of Sciences, Budapest (Hungary)

    2013-03-01

    Pulse radiolysis experiments were used to characterize the intermediates formed from ibuprofen during electron beam irradiation in a solution of 0.1 mmol dm{sup −3}. For end product characterization {sup 60}Co γ-irradiation was used and the samples were evaluated either by taking their UV–vis spectra or by HPLC with UV or MS detection. The reactions of {sup ·}OH resulted in hydroxycyclohexadienyl type radical intermediates. The intermediates produced in further reactions hydroxylated the derivatives of ibuprofen as final products. The hydrated electron attacked the carboxyl group. Ibuprofen degradation is more efficient under oxidative conditions than under reductive conditions. The ecotoxicity of the solution was monitored by Daphnia magna standard microbiotest and Vibrio fischeri luminescent bacteria test. The toxic effect of the aerated ibuprofen solution first increased upon irradiation indicating a higher toxicity of the first degradation products, then decreased with increasing absorbed dose. Highlights: ► In hydroxyl radical attack on the ring mainly hydroxylated products form ► The hydrated electron attacks the carboxyl group. ► Oxidative conditions are more effective in ibuprofen decomposition than reductive. ► Ecotoxicity of ibuprofen solution first increases then decreases with irradiation.

  13. NADH Induces the Generation of Superoxide Radicals in Leaf Peroxisomes.

    Science.gov (United States)

    Del Río, L A; Fernández, V M; Rupérez, F L; Sandalio, L M; Palma, J M

    1989-03-01

    In peroxisomes isolated from pea leaves (Pisum sativum L.) the production of superoxide free radicals (O(2) (-)) by xanthine and NADH was investigated. In peroxisomal membranes, 100 micromolar NADH induced the production of O(2) (-) radicals. In the soluble fractions of peroxisomes, no generation of O(2) (-) radicals was observed by incubation with either NADH or xanthine, although xanthine oxidase was found located predominantly in the matrix of peroxisomes. The failure of xanthine to induce superoxide generation was probably due to the inability to fully suppress the endogenous Mn-superoxide dismutase activity by inhibitors which were inactive against xanthine oxidase. The generation of superoxide radicals in leaf peroxisomes together with the recently described production of these oxygen radicals in glyoxysomes (LM Sandalio, VM Fernández, FL Rupérez, LA del Río [1988] Plant Physiol 87: 1-4) suggests that O(2) (-) generation could be a common metabolic property of peroxisomes and further supports the existence of active oxygen-related rôles for peroxisomes in cellular metabolism.

  14. Radiation-induced degradation of DNA bases

    Science.gov (United States)

    Douki, T.; Delatour, T.; Martini, R.; Cadet, J.

    1999-01-01

    Radio-induced degradation of DNA involves radical processes. A series of lesions among the major bases degradation products 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 four bases are degraded in high yield. Direct effect has been mimicked by photo-induced electron abstraction from the bases producing their radical cation. Quantification of the modified bases showed that guanine is the preferential target. This can be explained by its lower oxidation potential and charge transfer phenomena. La décomposition radio-induite de l'ADN fait intervenir des processus radicalaires. Une série de lésions choisies parmi les produits majeurs de dégradation des bases a été mesurée dans de l'ADN isolé exposé au rayonnement en solution aqueuse aérée. Les modifications sont alors dues aux radicaux hydroxyles produits par la radiolyse de l'eau (effet indirect) et les quatre bases sont efficacement dégradées. L'arrachement d'électrons aux bases par photosensibilisation pour produire leur radical cation, a été utilisé comme modèle de l'effet direct. La quantification des bases modifiées montre que la guanine est préférentiellement dégradée. Cette observation peut s'expliquer par le plus faible potentiel d'oxydation de cette base ainsi que par les phénomènes de transfert de charge vers les guanines.

  15. Radiation-induced cardiovascular effects

    Science.gov (United States)

    Tapio, Soile

    Recent epidemiological studies indicate that exposure to ionising radiation enhances the risk of cardiovascular mortality and morbidity in a moderate but significant manner. Our goal is to identify molecular mechanisms involved in the pathogenesis of radiation-induced cardiovascular disease using cellular and mouse models. Two radiation targets are studied in detail: the vascular endothelium that plays a pivotal role in the regulation of cardiac function, and the myocardium, in particular damage to the cardiac mitochondria. Ionising radiation causes immediate and persistent alterations in several biological pathways in the endothelium in a dose- and dose-rate dependent manner. High acute and cumulative doses result in rapid, non-transient remodelling of the endothelial cytoskeleton, as well as increased lipid peroxidation and protein oxidation of the heart tissue, independent of whether exposure is local or total body. Proteomic and functional changes are observed in lipid metabolism, glycolysis, mitochondrial function (respiration, ROS production etc.), oxidative stress, cellular adhesion, and cellular structure. The transcriptional regulators Akt and PPAR alpha seem to play a central role in the radiation-response of the endothelium and myocardium, respectively. We have recently started co-operation with GSI in Darmstadt to study the effect of heavy ions on the endothelium. Our research will facilitate the identification of biomarkers associated with adverse cardiac effects of ionising radiation and may lead to the development of countermeasures against radiation-induced cardiac damage.

  16. Radiation-induced hemorrhagic cystitis.

    Science.gov (United States)

    Alesawi, Anwar M; El-Hakim, Assaad; Zorn, Kevin C; Saad, Fred

    2014-09-01

    To better understand the mechanism of radiation-induced hemorrhagic cystitis and the advantages and disadvantages of available treatment options for bladder hemorrhage as well as preventive measures. There have been several attempts recently to manage hemorrhagic cystitis with hyperbaric oxygen therapy, transurethral coagulation using Greenlight potassium-titanyl-phosphate laser and other different treatment modalities, but we still need more investigation on larger cohort studies. Hemorrhagic cystitis is an uncommon urological problem. It is most often caused by radiation therapy and cyclophosphamide, but can be associated with other contributing factors. Technological advances in radiation therapy have resulted in greater treatment efficacy, with significant reduction in side-effects such as hemorrhagic cystitis. Higher dose radiation treatment, however, is more often associated with problematic hemorrhagic cystitis. Treatment of hemorrhagic cystitis is multifactorial and can range from simple bladder irrigation to cystectomy with urinary diversion.

  17. Pulsed radiation studies of carotenoid radicals and excited states

    Energy Technology Data Exchange (ETDEWEB)

    Burke, M

    2001-04-01

    The one-electron reduction potentials of the radical cations of five dietary carotenoids, in aqueous micellar environments, have been obtained from a pulse radiolysis study of electron transfer between the carotenoids and tryptophan radical cations as a function of pH, and lie in the range 980 to 1060 mV. The decays of the carotenoid radical cations suggest a distribution of exponential lifetimes. The radicals persist for up to about one second, depending on the medium and may re-orientate within a biological environment to react with other biomolecules, such as tyrosine, cysteine or ascorbic acid, which was indeed confirmed. Spectral information of carotenoid pigmented liposomes has been collected, subsequently pulse radiolysis was used to generate the radical cations of {beta}-carotene, zeaxanthin and lutein, in unilamellar vesicles of dipalmitoyl phosphatidyl choline. The rate constants for the 'repair' of these carotenoid radical cations by water-soluble vitamin C were found to be similar ({approx}1 x 10{sup 7} M{sup -1}s{sup -1}) for {beta}-carotene and zeaxanthin and somewhat lower ({approx}0.5 x 10{sup 7} M{sup -1}s{sup -1}) for lutein. The results are discussed in terms of the microenvironment of the carotenoids and suggest that for {beta}-carotene, a hydrocarbon carotenoid, the radical cation is able to interact with a water-soluble species even though the parent hydrocarbon carotenoid is probably entirely in the non-polar region of the liposome. Studies investigating the ability of ingested lycopene to protect human lymphoid cells against singlet oxygen and nitrogen dioxide radical mediated cell damage have shown that a high lycopene diet is beneficial in protecting human cells against reactive oxygen species. Triplet states of carotenoids were produced in benzene solvent and their triplet lifetimes were found to depend on the concentration of the parent molecule. The rate constants obtained for ground state quenching correlate with the number

  18. Radiation-induced chromosomal instability

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-03-01

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

  19. At the crossroad of photochemistry and radiation chemistry: formation of hydroxyl radicals in diluted aqueous solutions exposed to ultraviolet radiation.

    Science.gov (United States)

    Tomanová, Kateřina; Precek, Martin; Múčka, Viliam; Vyšín, Luděk; Juha, Libor; Čuba, Václav

    2017-11-08

    Formation yields of ˙OH radicals were precisely determined in aqueous solutions of coumarin-3-carboxylic acid and ferrous sulfate (i.e., Fricke dosimeter) exposed to 253.7 nm radiation delivered from a continuous source. Quantum yield of ˙OH radicals was determined as ∼0.08, i.e., roughly one out of twelve photons, efficiently absorbed in UV-illuminated solutions, produced one ˙OH radical. Energetically, a water molecule should undergo a correlated action of at least two 4.9 eV photons delivering enough energy for direct H-OH dissociation (5.0-5.4 eV). We suggest a mechanism based on an interaction of two water molecules, both in long-living triplet states. An intermolecular transfer of excitation energy provided a sufficient amount of energy for the dissociation of one water molecule into ˙OH and H˙ radicals. In an aqueous solution of phospholipids, quantum yields of hydroperoxides formed under these irradiation conditions decreased with total effectively absorbed energy (i.e. a dose), similar to the radiation chemical yields obtained during an exposure to ionizing radiation, such as gamma rays from radionuclide sources. Under 253.7 nm irradiation, one ˙OH radical causes a peroxidation of 34 phospholipid molecules. This implicates chain mechanism of the reaction.

  20. The importance of radiation chemistry to radiation and free radical biology (The 2008 Silvanus Thompson Memorial Lecture).

    Science.gov (United States)

    Wardman, P

    2009-02-01

    Biological effects of radiation are manifest over timescales extending to years. However, many chemical events are complete in milliseconds; after this time, adding oxygen to irradiated hypoxic cells no longer enhances radiosensitivity. This does not mean that damage pathways cannot be modified; the potential gain from chemical modulation of early events is as large as any associated with later pathways, and the prognostic importance of variations in levels of small molecules active in fast free radical pathways is as important as any associated with genetic make-up. Reactive oxygen species are much invoked in the wider context, but are frequently undefined and seldom measured unambiguously. Radiation chemistry has much to offer to both radiation and free radical biology. An appreciation of the interlinked parameters of time, spatial distribution and yield is well developed, as are methods to generate specific radicals in known concentrations and to monitor their reactions directly. Intense clinical interest in the 1980s in hypoxic cell radiosensitizers, developed from radiation chemical studies, has waned, but the goal of eliminating hypoxic radioresistance remains attractive. Nitric oxide may be more important than oxygen in determining hypoxic radiosensitivity, and radiation chemistry provides the tools to understand the mechanisms and the limitations of in vitro models. Imaging hypoxia in tumours relies heavily on free radical chemistry and radiolysis methods to understand the mechanistic basis for diagnostic agents. Quantitation of the chemical reactivity of free radicals is a cornerstone of radiation chemistry via the language, concepts and mathematics of chemical kinetics, which are equally applicable to understanding the molecular pathways in radiobiology.

  1. Radiation-Induced Oral Mucositis

    Directory of Open Access Journals (Sweden)

    Osama Muhammad Maria

    2017-05-01

    Full Text Available Radiation-induced oral mucositis (RIOM is a major dose-limiting toxicity in head and neck cancer patients. It is a normal tissue injury caused by radiation/radiotherapy (RT, which has marked adverse effects on patient quality of life and cancer therapy continuity. It is a challenge for radiation oncologists since it leads to cancer therapy interruption, poor local tumor control, and changes in dose fractionation. RIOM occurs in 100% of altered fractionation radiotherapy head and neck cancer patients. In the United Sates, its economic cost was estimated to reach 17,000.00 USD per patient with head and neck cancers. This review will discuss RIOM definition, epidemiology, impact and side effects, pathogenesis, scoring scales, diagnosis, differential diagnosis, prevention, and treatment.

  2. Radical surgery in patients with residual disease after (chemo)radiation for cervical cancer

    NARCIS (Netherlands)

    Boers, Aniek; Arts, Henriette J. G.; Klip, Harry; Nijhuis, Esther R.; Pras, Elisabeth; Hollema, Harry; Wisman, G. Bea A.; Nijman, Hans W.; Mourits, Marian J. E.; Reyners, Anna K. L.; de Bock, Geertruida H.; Thomas, Gillian; van der Zee, Ate G. J.

    Objective: The aim of this study was to determine possible impact of routinely scheduled biopsies and more radical surgery for residual central disease in locally advanced cervical cancer after (chemo) radiation. Methods/Materials: Data were analyzed of a consecutive series of cervical cancer

  3. Applications of Fast, Facile, Radiation-Free Radical Polymerization Techniques Enabled by Room Temperature Alkylborane Chemistry.

    Science.gov (United States)

    Ahn, Dongchan; Wier, Kevin A; Mitchell, Timothy P; Olney, Patricia A

    2015-11-04

    Fast, robust, and scalable techniques for covalent materials assembly are shown to be enabled by variants of a simple mixing-induced free radical initiation scheme broadly termed room-temperature alkylborane (RTA) chemistry. Unique process versatility, speed of reaction, high conversion, and structural control at ambient conditions occur by exploiting air-stable alkylborane-amine complexes that rapidly initiate upon mixing with common amine-reactive decomplexing agents such as carboxylic acid compounds. Three diverse application examples are presented, illustrating facile ambient routes to covalent assembly varying in length scale: (1) copolymers with controllable pressure-sensitive adhesive properties, (2) hydrophilically modified silicone microparticles from heterophase reactions, and (3) UV-free inkjet printable materials suitable for thick-textured patterning and printing, all conducted in open air with no radiation or atmospheric control. These examples demonstrate that this simple "bucket chemistry" can create intriguing degrees of freedom for polymerization, cross-linking and covalent macromolecular assembly with controllable structure and properties, suggesting further opportunities for both fundamental mechanistic investigation and application to a range of old and new materials assembly problems across length scales.

  4. Radical radiation therapy for oligometastatic breast cancer: Results of a prospective phase II trial.

    Science.gov (United States)

    Trovo, Marco; Furlan, Carlo; Polesel, Jerry; Fiorica, Francesco; Arcangeli, Stefano; Giaj-Levra, Niccolò; Alongi, Filippo; Del Conte, Alessandro; Militello, Loredana; Muraro, Elena; Martorelli, Debora; Spazzapan, Simon; Berretta, Massimiliano

    2017-09-21

    We conducted a prospective phase II multicentric trial to determine if radical radiation therapy to all metastatic sites might improve the progression-free survival (PFS) in oligometastatic breast cancer patients. Secondary endpoints were local control (LC), overall survival (OS) and toxicity. Inclusion criteria were the following: oligometastatic breast cancer with ≤5 metastatic sites, FDG-PET/CT staging, no brain metastases, primary tumor controlled. Radiotherapy could be delivered using stereotactic body radiotherapy (SBRT) technique or fractionated intensity modulated radiotherapy (IMRT). SBRT consisted of 30-45Gy in 3 fractions, while IMRT was delivered to a total dose of 60Gy in 25 fractions. We hypothesized that radical radiation therapy could increase the PFS from 30% (according to the published literature) to 50% at two years. 54 Patients with 92 metastatic lesions were enrolled. Forty-four were treated with SBRT, and 10 with IMRT. Forty-eight (89%) patients received a form of systemic therapy concomitantly to radiation therapy. Sites of metastatic disease were the following: bones 60 lesions, lymph nodes 23 lesions, lung 4 lesions, liver 5 lesions. After a median follow-up of 30months (range, 6-55months), 1- and 2-year PFS was 75% and 53%, respectively. Two-year LC and OS were 97% and 95%, respectively. Radiation therapy was well tolerated, and no Grade ≥3 toxicity was documented. Grade 2 toxicity were pain and fatigue in 2 cases. Patients with oligometastatic breast cancer treated with radical radiotherapy to all metastatic sites may achieve long-term progression-free survival, without significant treatment-related toxicity. While waiting for data from randomized trials, the use of radical radiation therapy to all metastatic sites in patients with oligometastatic breast cancer should be considered a valuable option, and its recommendation should be individualized. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Differential effects of radical scavengers on X-ray-induced mutation and cytotoxicity in human cells

    Energy Technology Data Exchange (ETDEWEB)

    Corn, B.W.; Liber, H.L.; Little, J.B.

    1987-01-01

    The cytotoxic and mutagenic effects of X irradiation on a human lymphoblast cell line were examined in the presence of two radioprotective agents which modulate damage to DNA. The cells were treated with X rays alone or in the presence of either dimethyl sulfoxide or cysteamine. Surviving fraction and mutation to trifluorothymidine resistance (tk locus) and to 6-thioguanine resistance (hgprt locus) were measured. Survival was enhanced when the cells were irradiated in the presence of dimethyl sulfoxide; the D0 rose from 58 to 107 rad. However, at both genetic loci the induced mutant fractions were identical in the presence or absence of dimethyl sulfoxide. Survival was enhanced to a greater degree when the cells were irradiated in the presence of cysteamine; the D0 rose from 58 to 200 rad. Cysteamine also protected the cells from X-ray-induced mutation; the frequencies of X-ray-induced mutation at both the tk and hgprt loci were reduced by 50-75%. No protective effects were observed unless dimethyl sulfoxide or cysteamine was present during irradiation. These findings are discussed in terms of the hypothesis that, unlike for cell killing, radiation-induced mutagenesis in human lymphoblast cells is not mediated by the actions of aqueous free radicals, but rather by the direct effects of ionizing radiation.

  6. Effect of propofol on in vitro lipid peroxidation induced by different free radical generating systems: a comparison with vitamin E.

    Science.gov (United States)

    Hans, P; Deby, C; Deby-Dupont, G; Vrijens, B; Albert, A; Lamy, M

    1996-04-01

    Propofol has been reported to have antioxidant properties and to inhibit lipid peroxidation. In this study, we examined the ability of propofol to inhibit lipid peroxidation induced by three free radical systems (hydroxyl, ferryl, and oxo-ferryl radicals), and we compared the effect of propofol with that of vitamin E, an endogenous antioxidant. Lipid peroxidation was induced by exposing a linoleic acid emulsion to either water gamma radiation, a ferrous iron-ascorbate solution, or human hemoglobin, generating the hydroxyl, ferryl, and oxo-ferryl radicals, respectively. Each experiment was performed in triplicate with and without propofol or vitamin E at concentrations between 10(-5) and 10(-4) M. Lipid peroxidation was quantified by gas chromatography measurement of the pentane released (nmoles) from lipid decomposition. In each condition, a significant dose-response relationship was found between the release of pentane and the concentration of either propofol or vitamin E. The antioxidant activities of both agents were similar but significantly higher against the hydroxyl than the ferryl and oxo-ferryl radicals. The study suggests that propofol could be beneficial as an anesthetic or sedative drug in patients presenting pathologies associated with free radical reactions.

  7. Antihistamines block radiation-induced taste aversions.

    Science.gov (United States)

    Levy, C J; Carroll, M E; Smith, J C; Hofer, K G

    1974-12-13

    When rats are treated with an antihistamine prior to being given sublethal doses of ionizing radiation, the formation of a conditioned saccharin aversion is completely inhibited. A profound aversion could be conditioned with histamine diphosphate as the aversive stimulus. The increase in histamine production after radiation exposure represents the physiological basis of radiation-induced taste aversions.

  8. Volatility of secondary organic aerosol during OH radical induced ageing

    Directory of Open Access Journals (Sweden)

    K. Salo

    2011-11-01

    Full Text Available The aim of this study was to investigate oxidation of SOA formed from ozonolysis of α-pinene and limonene by hydroxyl radicals. This paper focuses on changes of particle volatility, using a Volatility Tandem DMA (VTDMA set-up, in order to explain and elucidate the mechanism behind atmospheric ageing of the organic aerosol. The experiments were conducted at the AIDA chamber facility of Karlsruhe Institute of Technology (KIT in Karlsruhe and at the SAPHIR chamber of Forchungzentrum Jülich (FZJ in Jülich. A fresh SOA was produced from ozonolysis of α-pinene or limonene and then aged by enhanced OH exposure. As an OH radical source in the AIDA-chamber the ozonolysis of tetramethylethylene (TME was used while in the SAPHIR-chamber the OH was produced by natural light photochemistry. A general feature is that SOA produced from ozonolysis of α-pinene and limonene initially was rather volatile and becomes less volatile with time in the ozonolysis part of the experiment. Inducing OH chemistry or adding a new portion of precursors made the SOA more volatile due to addition of new semi-volatile material to the aged aerosol. The effect of OH chemistry was less pronounced in high concentration and low temperature experiments when lower relative amounts of semi-volatile material were available in the gas phase. Conclusions drawn from the changes in volatility were confirmed by comparison with the measured and modelled chemical composition of the aerosol phase. Three quantified products from the α-pinene oxidation; pinonic acid, pinic acid and methylbutanetricarboxylic acid (MBTCA were used to probe the processes influencing aerosol volatility. A major conclusion from the work is that the OH induced ageing can be attributed to gas phase oxidation of products produced in the primary SOA formation process and that there was no indication on significant bulk or surface reactions. The presented results, thus, strongly emphasise

  9. Radiation-induced leukemias in ankylosing spondylitis

    Energy Technology Data Exchange (ETDEWEB)

    Toolis, F. (Royal Infirmary, Edinburgh, UK); Potter, B.; Allan, N.C.; Langlands, A.O.

    1981-10-01

    Three cases of leukemia occurred in patients with ankylosing spondylitis treated by radiotherapy. In each case, the leukemic process exhibited bizarre features suggesting that radiation is likely to induce atypical forms of leukemia possessing unusual attributes not shared by spontaneously developing leukemia. The likely distinctive aspects of radiation-induced leukemia are discussed.

  10. Radiation Induced Bystander Effect in vivo

    OpenAIRE

    Chai, Yunfei; Hei K. Tom

    2009-01-01

    Radiation-induced bystander effect is defined as the induction of biological effects in cells that are not directly traversed by radiation, but merely in the presence of cells that are. Although radiation induced bystander effects have been well defined in a variety of in vitro models using a range of endpoints including clonogenic survival, mutations, neoplastic transformation, apoptosis, micronucleus, chromosomal aberrations and DNA double strand breaks, the mechanism(s) as well as the pres...

  11. Radiotherapy after radical prostatectomy: treatment recommendations differ between urologists and radiation oncologists.

    Directory of Open Access Journals (Sweden)

    Luke T Lavallée

    Full Text Available PURPOSE: There is no consensus on optimal use of radiotherapy following radical prostatectomy. The purpose of this study was to describe opinions of urologists and radiation oncologists regarding adjuvant and salvage radiotherapy following radical prostatectomy. METHODS: Urologists and genitourinary radiation oncologists were solicited to participate in an online survey. Respondent characteristics included demographics, training, practice setting, patient volume/experience, and access to radiotherapy. Participant practice patterns and attitudes towards use of adjuvant and salvage radiotherapy in standardized clinical scenarios were assessed. RESULTS: One hundred and forty-six staff physicians participated in the survey (104 urologists and 42 genitourinary radiation oncologists. Overall, high Gleason score (Gleason 7 vs. 6, RR 1.37 95% CI 1.19-1.56, p<0.0001 and Gleason 8-10 vs. 6, RR 1.56 95% CI 1.37-1.78, p<0.0001, positive surgical margin (RR 1.43 95% CI 1.26-1.62, p<0.0001, and extraprostatic tumour extension (RR 1.16 95% CI 1.05-1.28, p<0.002 conferred an increased probability of recommending adjuvant radiotherapy. Radiation oncologists were more likely to recommend adjuvant radiotherapy across all clinical scenarios (RR 1.48, 95% CI 1.39, 1.60, p <0.001. Major differences were found for patients with Gleason 6 and isolated positive surgical margin (radiotherapy selected by 21% of urologists vs. 70% of radiation oncologists, and patients with extraprostatic extension and negative surgical margins (radiotherapy selected by 18% of urologist vs. 57% of radiation oncologists. CONCLUSIONS: Urologists and radiation oncologists frequently disagree about recommendation for post-prostatectomy adjuvant radiotherapy. Since clinical equipoise exists between adjuvant versus early salvage post-operative radiotherapy, support of clinical trials comparing these approaches is strongly encouraged.

  12. Radiation induced oxidative damage modification by cholesterol in liposomal membrane

    Science.gov (United States)

    Pandey, B. N.; Mishra, K. P.

    1999-05-01

    Ionizing radiation induced structural and chemical alterations in egg lecithin liposomal membrane have been studied by measurements of lipid peroxides, conjugated diene and fluorescence polarization. Predominantly unilamellar phospholipid vesicles prepared by sonication procedure were subjected to radiation doses of γ-rays from Co-60 in aerated, buffered aqueous suspensions. The oxidative damage in irradiated lipid molecules of liposomes has been determined spectrophotometrically by diene conjugate formation and thiobarbituric acid reactive (TBAR) method as a function of radiation dose. A correlation was found between the radiation dose applied (0.1-1 kGy) and the consequent lipid oxidation. The damage produced in irradiated liposomal membrane was measured by 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence decay and polarization. The observed decrease in DPH fluorescence and increase in polarization was found dependent on the radiation dose suggesting alterations in rigidity or organizational order in phospholipid bilayer after irradiation. Furthermore, irradiated liposome vesicles composed of cholesterol showed marked reduction in observed radiation mediated peroxide formation and significantly affected the DPH fluorescence parameters. The magnitude of these modifying effects were found dependent on the mole fraction of cholesterol. It is concluded that modulation of structural order in unilamellar vesicle membrane by variations in basic molecular components controlled the magnitude of lipid peroxidation and diene conjugate formation. These observations contribute to our understanding of mechanism of radical reaction mediated damage caused by ionizing radiation in phospholipid membrane.

  13. Radiation induced oxidative damage modification by cholesterol in liposomal membrane

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, B.N. [Radiation Biology and Biochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai (India); Mishra, K.P. [Radiation Biology and Biochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai (India)

    1999-05-01

    Ionizing radiation induced structural and chemical alterations in egg lecithin liposomal membrane have been studied by measurements of lipid peroxides, conjugated diene and fluorescence polarization. Predominantly unilamellar phospholipid vesicles prepared by sonication procedure were subjected to radiation doses of {gamma}-rays from Co-60 in aerated, buffered aqueous suspensions. The oxidative damage in irradiated lipid molecules of liposomes has been determined spectrophotometrically by diene conjugate formation and thiobarbituric acid reactive (TBAR) method as a function of radiation dose. A correlation was found between the radiation dose applied (0.1-1 kGy) and the consequent lipid oxidation. The damage produced in irradiated liposomal membrane was measured by 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence decay and polarization. The observed decrease in DPH fluorescence and increase in polarization was found dependent on the radiation dose suggesting alterations in rigidity or organizational order in phospholipid bilayer after irradiation. Furthermore, irradiated liposome vesicles composed of cholesterol showed marked reduction in observed radiation mediated peroxide formation and significantly affected the DPH fluorescence parameters. The magnitude of these modifying effects were found dependent on the mole fraction of cholesterol. It is concluded that modulation of structural order in unilamellar vesicle membrane by variations in basic molecular components controlled the magnitude of lipid peroxidation and diene conjugate formation. These observations contribute to our understanding of mechanism of radical reaction mediated damage caused by ionizing radiation in phospholipid membrane.

  14. Effect of radiation quality on radical formation in ion-irradiated solid alanine

    Energy Technology Data Exchange (ETDEWEB)

    Koizumi, Hitoshi; Ichikawa, Tsuneki; Yoshida, Hiroshi [Hokkaido Univ., Sapporo (Japan); Namba, Hideki; Taguchi, Mitsumasa; Kojima, Takuji

    1997-03-01

    Radical formation in solid alanine irradiated with H{sup +} and He{sup +} ions of 0.5-3.0 MeV and with heavy ions of hundreds of MeV was examined by the ESR method. Radical yield is constant below a critical fluence, and the yield decreases above the fluence. The critical fluence for the H{sup +} and He{sup +} ions is about 10{sup 12} ions cm{sup -2}, while the critical fluence for the heavy ions is 10{sup 10}-10{sup 11} ions cm{sup -2}. G-value of the radical formation (radicals per 100 eV absorbed dose) is obtained from the constant yield at the low fluences. The G-value depends on the radiation quality. This dependence is ascribed to the difference of local dose in the ion tracks. The fluence-yield curves were simulated with a model assuming cylindrical shape of ion tracks and dose-yield relationship for {gamma}-irradiation. This model well explains the fluence-yield curves for the ion irradiations. (author)

  15. Radiation-Induced Vaccination to Breast Cancer

    Science.gov (United States)

    2015-10-01

    Award Number: W81XWH-11-1-0531 TITLE: Radiation-Induced Vaccination to Breast Cancer PRINCIPAL INVESTIGATOR: William H. McBride CONTRACTING...FORM TO THE ABOVE ADDRESS. 1. REPORT DATE 2. REPORT TYPE Annual 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Radiation-Induced Vaccination to...determine abscopal responses that are hypothesized to be due to RT- induced vaccination . RT was started 10 days after the first and 3rd dose of

  16. Photo-induced free radicals on a simulated Martian surface

    Science.gov (United States)

    Tseng, S.-S.; Chang, S.

    1974-01-01

    Results of an electron spin resonance study of free radicals in the ultraviolet irradiation of a simulated Martian surface suggest that the ultraviolet photolysis of CO or CO2, or a mixture of both, adsorbed on silica gel at minus 170 C involves the formation of OH radicals and possibly of H atoms as the primary process, followed by the formation of CO2H radicals. It is concluded that the photochemical synthesis of organic compounds could occur on Mars if the siliceous surface dust contains enough silanol groups and/or adsorbed H2O in the form of bound water.

  17. Controlled/living radical polymerization of methyl methacrylate using γ-radiation as an initiation source

    Science.gov (United States)

    Zhou, Ying; Zhu, Jian; Zhu, Xiulin; Cheng, Zhenping

    2006-04-01

    A controlled/living radical polymerization, initiated by γ-radiation and followed by a post-polymerization process, of methyl methacrylate (MMA) was carried out in the presence of 2-cyanoprop-2-yl 1-dithionaphthalate. The polymerization showed first-order kinetics. The molecular weights of the corresponding polymers increased linearly with conversion. The molecular weight distributions ( M/M) of the polymers decreased with the conversion (minimal M/M value: 1.09). The polymers were characterized by 1H NMR and gel-permeation chromatograph. Chain-extension reaction was also successfully carried out to obtain higher molecular weight PMMA with narrow molecular weight distribution.

  18. Lipid radicals cause light-induced retinal degeneration.

    Science.gov (United States)

    Enoki, Masataka; Shinto, Saki; Matsuoka, Yuta; Otsuka, Ayasa; Kaidzu, Sachiko; Tanito, Masaki; Shibata, Takahiro; Uchida, Koji; Ohira, Akihiro; Yamato, Mayumi; Yamada, Ken-Ichi

    2017-10-03

    Age-related macular degeneration (AMD) is the leading cause of blindness worldwide. Although the cause of AMD remains unknown, lipid peroxidation (LPO) end-products are critical molecules for its development. Herein, we report the imaging of lipid radicals, which are key factors in the LPO reaction, and therapeutic information using animal models.

  19. Free radicals induced by sunlight in different spectral regions - in vivo versus ex vivo study.

    Science.gov (United States)

    Lohan, Silke B; Müller, Robert; Albrecht, Stephanie; Mink, Kathrin; Tscherch, Kathrin; Ismaeel, Fakher; Lademann, Jürgen; Rohn, Sascha; Meinke, Martina C

    2016-05-01

    Sunlight represents an exogenous factor stimulating formation of free radicals which can induce cell damage. To assess the effect of the different spectral solar regions on the development of free radicals in skin, in vivo electron paramagnetic resonance (EPR) investigations with human volunteers and ex vivo studies on excised human and porcine skin were carried out. For all skin probes, the ultraviolet (UV) spectral region stimulates the most intensive radical formation, followed by the visible (VIS) and the near infrared (NIR) regions. A comparison between the different skin models shows that for UV light, the fastest and highest production of free radicals could be detected in vivo, followed by excised porcine and human skin. The same distribution pattern was found for the VIS/NIR spectral regions, whereby the differences in radical formation between in vivo and ex vivo were less pronounced. An analysis of lipid composition in vivo before and after exposure to UV light clearly showed modifications in several skin lipid components; a decrease of ceramide subclass [AP2] and an increase of ceramide subclass [NP2], sodium cholesterol sulphate and squalene (SQ) were detectable. In contrast, VIS/NIR irradiation led to an increase of ceramides [AP2] and SCS, and a decrease of SQ. These results, which are largely comparable for the different skin models investigated in vivo and ex vivo, indicate that radiation exposure in different spectral regions strongly influences radical production in skin and also results in changes in skin lipid composition, which is essential for barrier function. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. 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.

  1. Hydrogen-rich PBS protects cultured human cells from ionizing radiation-induced cellular damage

    Directory of Open Access Journals (Sweden)

    Qian Liren

    2010-01-01

    Full Text Available Hydroxyl radicals play an important role in ionizing radiation-induced cellular damage, while hydrogen can selectively reduce hydroxyl radicals in vitro. This study was designed to test the hypothesis that hydrogen-rich PBS may be an effective radioprotective agent in vitro. Compared to cells pretreated without hydrogen, we demonstrated that treating cells with hydrogen-rich PBS before irradiation could significantly inhibit IR-induced apoptosis, increase viability of human intestinal crypt cells, significantly increase endogenous antioxidant, and decrease malondialdehyde and 8-hydroxydeoxyguanosine concentrations of human lymphocyte AHH-1 cells. It is concluded that hydrogen has a potential as an effective and safe radioprotective agent.

  2. Numerical analysis of quantitative measurement of hydroxyl radical concentration using laser-induced fluorescence in flame

    Science.gov (United States)

    Shuang, Chen; Tie, Su; Yao-Bang, Zheng; Li, Chen; Ting-Xu, Liu; Ren-Bing, Li; Fu-Rong, Yang

    2016-06-01

    The aim of the present work is to quantitatively measure the hydroxyl radical concentration by using LIF (laser-induced fluorescence) in flame. The detailed physical models of spectral absorption lineshape broadening, collisional transition and quenching at elevated pressure are built. The fine energy level structure of the OH molecule is illustrated to understand the process with laser-induced fluorescence emission and others in the case without radiation, which include collisional quenching, rotational energy transfer (RET), and vibrational energy transfer (VET). Based on these, some numerical results are achieved by simulations in order to evaluate the fluorescence yield at elevated pressure. These results are useful for understanding the real physical processes in OH-LIF technique and finding a way to calibrate the signal for quantitative measurement of OH concentration in a practical combustor. Project supported by the National Natural Science Foundation of China (Grant No. 11272338) and the Fund from the Science and Technology on Scramjet Key Laboratory, China (Grant No. STSKFKT2013004).

  3. 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

  4. Protective effects of Korean mistletoe lectin on radical-induced oxidative stress.

    Science.gov (United States)

    Kim, Boh Kyung; Choi, Mi Jin; Park, Kun Young; Cho, Eun Ju

    2010-01-01

    The radical scavenging effects and protective activities against oxidative stress of Korean mistletoe (Viscum album coloratum) lectin were investigated in vitro and with a cellular system using LLC-PK(1) renal epithelial cells. The Korean mistletoe lectin (KML) showed 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity with an IC(50) value of 42.6 microg/ml. It also exerted nitric oxide (NO), superoxide anion (O(2)(-)), and hydroxyl radical scavenging activities in concentration-dependent manners. These results suggest that KML is a promising antioxidant by scavenging free radicals. Furthermore, under the LLC-PK(1) cellular model, the cells showed declines in viability and increases in lipid peroxidation through oxidative stress induced by sodium nitroprusside (SNP) and pyrogallol, generators of NO and O(2)(-), respectively. However, KML significantly and dose-dependently inhibited cell cytotoxicity and lipid peroxidation. In addition, 3-morpholinosydnonimnie (SIN-1), a generator of peroxynitrite (ONOO(-)) formed by simultaneously releases of NO and O(2)(-), caused cytotoxicity, lipid peroxidation, and NO overproduction in the LLC-PK(1) cells while KML ameliorated ONOO(-)-induced oxidative damage. Furthermore, overexpressions of cyclooxygenase-2 and inducible NO synthase induced by SIN-1 were observed, but KML down-regulated the expression levels of both genes. KML also reduced SIN-1-induced nuclear factor kappa B expression and the phosphorylation of inhibitor kappa B alpha in LLC-PK(1) cells. These results indicate that KML has protective activities against oxidative damage induced by free radicals.

  5. Protective effect of saponins from Argania spinosa against free radical-induced oxidative haemolysis.

    Science.gov (United States)

    Amzal, H; Alaoui, K; Tok, S; Errachidi, A; Charof, R; Cherrah, Y; Benjouad, A

    2008-07-01

    Saponins from Argania spinosa at a non-haemolytic concentration diminish by 53.2% erythrocyte haemolysis induced by free radicals. 2 mM aspirin and acetaminophen diminish by 75% and 68% , respectively, erythrocyte haemolysis induced by free radicals, while 0.3 microM vitamin E shows no significant antioxidant activity. Interestingly, a combination of 1 mg/l of A. spinosa saponins and vitamin E at 0.3 microM resulted in a 68% level of protection against free radical-induced erythrocyte haemolysis, which may suggest that A. spinosa saponins enhance the antioxidant effect of vitamin E. In contrast, no synergic effect was observed for acetaminophen (2 mM) when in combination with vitamin E (0.3 microM). These results demonstrate the antioxidant properties of saponins from A. spinosa and their ability to potentate the antioxidant effect of vitamin E.

  6. 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.

  7. 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.

  8. Free radical scavengers in mercuric chloride-induced acute renal failure in the rat.

    Science.gov (United States)

    Paller, M S

    1985-04-01

    Oxygen free radicals have recently been found to mediate cell injury after ischemia in the kidney. We sought to determine whether oxygen free radicals mediate damage in mercuric chloride (HgCl2)-induced acute renal failure, a toxic model of acute renal failure. Neither superoxide dismutase nor allopurinol, which scavenges or inhibits production of superoxide radical, respectively, provided protection against renal dysfunction after HgCl2. Similarly, the hydroxyl radical scavengers tryptophan, N-acetyl-tryptophan, and ascorbic acid were unable to protect against HgCl2. However, dimethylthiourea and dimethyl sulfoxide, both hydroxyl radical scavengers, were beneficial. Dimethylthiourea completely prevented the rise in plasma creatinine concentration after HgCL2. In control rats plasma creatinine concentration rose from 0.4 mg/dl to 3.2 +/- 0.8, 5.1 +/- 1.0, and 6.1 +/- 1.6 mg/dl at 24, 48, and 72 hours after HgCl2. Dimethylthiourea-treated rats had plasma creatinine concentration less than 0.5 mg/dl at all times. Furthermore, a mixture of HgCl2 and equimolar amounts of dimethylthiourea was less toxic than HgCl2 alone. Dimethyl sulfoxide attenuated the HgCl2-induced rise in creatinine concentration: 1.3 +/- 0.2, 3.2 +/- 0.3, and 3.1 +/- 0.2 mg/dl at 24, 48, and 72 hours after HgCl2. Measurement of kidney malondialdehyde content after HgCl2 provided no evidence for oxygen free radical-mediated lipid peroxidation. We conclude that there is no convincing role for oxygen free radicals in the pathogenesis of HgCl2-induced acute renal failure. The ability of dimethylthiourea and dimethyl sulfoxide to protect against HgCl2-induced renal dysfunction may be related to their ability to form complexes with Hg2+.

  9. Strong correlation between levels of tropospheric hydroxyl radicals and solar ultraviolet radiation.

    Science.gov (United States)

    Rohrer, Franz; Berresheim, Harald

    2006-07-13

    The most important chemical cleaning agent of the atmosphere is the hydroxyl radical, OH. It determines the oxidizing power of the atmosphere, and thereby controls the removal of nearly all gaseous atmospheric pollutants. The atmospheric supply of OH is limited, however, and could be overcome by consumption due to increasing pollution and climate change, with detrimental feedback effects. To date, the high variability of OH concentrations has prevented the use of local observations to monitor possible trends in the concentration of this species. Here we present and analyse long-term measurements of atmospheric OH concentrations, which were taken between 1999 and 2003 at the Meteorological Observatory Hohenpeissenberg in southern Germany. We find that the concentration of OH can be described by a surprisingly linear dependence on solar ultraviolet radiation throughout the measurement period, despite the fact that OH concentrations are influenced by thousands of reactants. A detailed numerical model of atmospheric reactions and measured trace gas concentrations indicates that the observed correlation results from compensations between individual processes affecting OH, but that a full understanding of these interactions may not be possible on the basis of our current knowledge of atmospheric chemistry. As a consequence of the stable relationship between OH concentrations and ultraviolet radiation that we observe, we infer that there is no long-term trend in the level of OH in the Hohenpeissenberg data set.

  10. Hypochlorite and superoxide radicals can act synergistically to induce fragmentation of hyaluronan and chondroitin sulphates

    DEFF Research Database (Denmark)

    Rees, Martin D; Hawkins, Clare Louise; Davies, Michael Jonathan

    2004-01-01

    -N*-C(O)-R'], polymer-derived carbon-centred radicals and site-specific strand scission. In the present study, we have shown that exposure of glycosaminoglycan chloramides to O2*- also promotes chloramide decomposition and glycosaminoglycan fragmentation. These processes are inhibited by superoxide dismutase, metal ion...... provided evidence for both O2*- and polymer-derived carbon-centred radicals as intermediates. The results obtained are consistent with a mechanism involving one-electron reduction of the chloramides to yield polymer-derived amidyl radicals, which subsequently undergo intramolecular hydrogen atom...... abstraction reactions to give carbon-centred radicals. The latter undergo fragmentation reactions in a site-specific manner. This synergistic damage to glycosaminoglycans induced by HOCl and O2*- may be of significance at sites of inflammation where both oxidants are generated concurrently....

  11. Amelioration of ionizing radiation induced lipid peroxidation in mouse liver by Moringa oleifera Lam. leaf extract.

    Science.gov (United States)

    Sinha, Mahuya; Das, Dipesh Kr; Datta, Sanjukta; Ghosh, Santinath; Dey, Sanjit

    2012-03-01

    Protective effect of Moringa oleifera leaf extract (MoLE) against radiation-induced lipid peroxidation has been investigated. Swiss albino mice, selected from an inbred colony, were administered with MoLE (300 mg/kg body wt) for 15 days before exposing to a single dose of 5 Gy 60Co-gamma radiation. After treatments, animals were necropsied at different post irradiation intervals (days 1, 7 and 15) and hepatic lipid peroxidation and reduced glutathione (GSH) contents were estimated to observe the relative changes due to irradiation and its possible amelioration by MoLE. It was observed that, MoLE treatment restored GSH in liver and prevented radiation induced augmentation in hepatic lipid peroxidation. Phytochemical analysis showed that MoLE possess various phytochemicals such as ascorbic acid, phenolics (catechin, epicatechin, ferulic acid, ellagic acid, myricetin) etc., which may play the key role in prevention of hepatic lipid peroxidation by scavenging radiation induced free radicals.

  12. 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.

  13. EPR persistence measurements of UV-induced melanin free radicals in whole skin

    Energy Technology Data Exchange (ETDEWEB)

    Collins, B.; Poehler, T.O. [Johns Hopkins Univ., Baltimore, MD (United States); Bryden, W.A. [Johns Hopkins Univ., Laurel, MD (United States). Applied Physics Lab.

    1995-09-01

    Electron paramagnetic resonance is used to detect the formation of free radicals caused by exposure to ultraviolet radiation in chemically untreated rabbit skin. A fast jump in EPR signal level, occurring over a few seconds, is observed immediately after a skin sample is exposed to UV. This is followed by a slower increase toward an elevated steady-state signal over a period of hours as the skin is continuously exposed to a UV light source. Upon cessation of UV light exposure, EPR signal levels undergo an abrupt drop followed by a slower decay toward natural levels. Elevated free radical concentrations following UV exposure are found to persist for several hours in whole skin. These results are consistent with time resolved EPR measurements of photoinduced radicals in various natural melanins. (Author).

  14. 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)

  15. Role of Oxidative Damage in Radiation-Induced Bone Loss

    Science.gov (United States)

    Schreurs, Ann-Sofie; Alwood, Joshua S.; Limoli, Charles L.; Globus, Ruth K.

    2014-01-01

    During prolonged spaceflight, astronauts are exposed to both microgravity and space radiation, and are at risk for increased skeletal fragility due to bone loss. Evidence from rodent experiments demonstrates that both microgravity and ionizing radiation can cause bone loss due to increased bone-resorbing osteoclasts and decreased bone-forming osteoblasts, although the underlying molecular mechanisms for these changes are not fully understood. We hypothesized that excess reactive oxidative species (ROS), produced by conditions that simulate spaceflight, alter the tight balance between osteoclast and osteoblast activities, leading to accelerated skeletal remodeling and culminating in bone loss. To test this, we used the MCAT mouse model; these transgenic mice over-express the human catalase gene targeted to mitochondria, the major organelle contributing free radicals. Catalase is an anti-oxidant that converts reactive species, hydrogen peroxide into water and oxygen. This animal model was selected as it displays extended lifespan, reduced cardiovascular disease and reduced central nervous system radio-sensitivity, consistent with elevated anti-oxidant activity conferred by the transgene. We reasoned that mice overexpressing catalase in mitochondria of osteoblast and osteoclast lineage cells would be protected from the bone loss caused by simulated spaceflight. Over-expression of human catalase localized to mitochondria caused various skeletal phenotypic changes compared to WT mice; this includes greater bone length, decreased cortical bone area and moment of inertia, and indications of altered microarchitecture. These findings indicate mitochondrial ROS are important for normal bone-remodeling and skeletal integrity. Catalase over-expression did not fully protect skeletal tissue from structural decrements caused by simulated spaceflight; however there was significant protection in terms of cellular oxidative damage (MDA levels) to the skeletal tissue. Furthermore, we

  16. Synthesis of block copolymers by combination of atom transfer radical polymerization and visible light-induced free radical promoted cationic polymerization.

    Science.gov (United States)

    Kahveci, Muhammet U; Acik, Gokhan; Yagci, Yusuf

    2012-02-27

    A new synthetic approach for the preparation of block copolymers by mechanistic transformation from atom transfer radical polymerization (ATRP) to visible light-induced free radical promoted cationic polymerization is described. A series of halide end-functionalized polystyrenes with different molecular weights synthesized by ATRP were utilized as macro-coinitiators in dimanganese decacarbonyl [Mn(2) (CO)(10) ] mediated free radical promoted cationic photopolymerization of cyclohexene oxide or isobutyl vinyl ether. Precursor polymers and corresponding block copolymers were characterized by spectral, chromatographic, and thermal analyses. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Radiation-induced myocardial perfusion abnormalities in breast cancer patients following external beam radiation therapy

    Directory of Open Access Journals (Sweden)

    Mohammad Eftekhari

    2015-01-01

    Full Text Available Objective(s: Radiation therapy for breast cancer can induce myocardial capillary injury and increase cardiovascular morbidity and mortality. A prospective cohort was conducted to study the prevalence of myocardial perfusion abnormalities following radiation therapy of left-sided breast cancer patients as compared to those with right–sided cancer. Methods: To minimize potential confounding factors, only those patients with low 10-year risk of coronary artery disease (based on Framingham risk scoring were included. All patients were initially treated by modified radical mastectomy and then were managed by postoperative 3D Conformal Radiation Therapy (CRT to the surgical bed with an additional 1-cm margin, delivered by 46-50 Gy (in 2 Gy daily fractions over a 5-week course. The same dose-adjusted chemotherapy regimen (including anthracyclines, cyclophosphamide and taxol was given to all patients. Six months after radiation therapy, all patients underwent cardiac SPECT for the evaluation of myocardial perfusion. Results: A total of 71 patients with a mean age of 45.3±7.2 years [35 patients with leftsided breast cancer (exposed and 36 patients with right-sided cancer (controls] were enrolled. Dose-volume histogram (DVH [showing the percentage of the heart exposed to >50% of radiation] was significantly higher in patients with left-sided breast cancer. Visual interpretation detected perfusion abnormalities in 42.9% of cases and 16.7% of controls (P=0.02, Odds ratio=1.46. In semiquantitative segmental analysis, only apical (28.6% versus 8.3%, P=0.03 and anterolateral (17.1% versus 2.8%, P=0.049 walls showed significantly reduced myocardial perfusion in the exposed group. Summed Stress Score (SSS of>3 was observed in twelve cases (34.3%, while in five of the controls (13.9%,(Odds ratio=1.3. There was no significant difference between the groups regarding left ventricular ejection fraction. Conclusion: The risk of radiation induced myocardial

  18. Interference Phenomena in Medium Induced Radiation

    CERN Document Server

    Casalderrey-Solana, Jorge

    2011-01-01

    We consider the interference pattern for the medium-induced gluon radiation produced by a color singlet quark-antiquark antenna embedded in a QCD medium with size $L$ and `jet quenching' parameter $\\hat q$. Within the BDMPS-Z regime, we demonstrate that, for a dipole opening angle $\\theta_{q\\bar q} \\gg\\theta_c\\equiv {2}/{\\sqrt{\\hat q L^3}}$, the interference between the medium--induced gluon emissions by the quark and the antiquark is suppressed with respect to the direct emissions. This is so since direct emissions are delocalized throughout the medium and thus yield contributions proportional to $L$ while interference occurs only between emissions at early times, when both sources remain coherent. Thus, for $\\tqq \\gg\\theta_c$, the medium-induced radiation is the sum of the two spectra individually produced by the quark and the antiquark, without coherence effects like angular ordering. For $\\tqq \\ll\\theta_c$, the medium--induced radiation vanishes.

  19. Antioxidative effects of Kimchi under different fermentation stage on radical-induced oxidative stress.

    Science.gov (United States)

    Kim, Boh Kyung; Choi, Ji Myung; Kang, Soon Ah; Park, Kun Young; Cho, Eun Ju

    2014-12-01

    Kimchi is a traditional Korean fermented vegetable containing several ingredients. We investigated the protective activity of methanol extract of kimchi under different fermentation stages against oxidative damage. Fresh kimchi (Fresh), optimally ripened kimchi (OptR), and over ripened kimchi (OvR) were fermented until the pH reached pH 5.6, pH 4.3, and pH 3.8, respectively. The radical scavenging activity and protective activity from oxidative stress of kimchi during fermentation were investigated under in vitro and cellular systems using LLC-PK1 cells. Kimchi exhibited strong radical scavenging activities against 1,1-diphenyl-2-picrylhydrazyl, nitric oxide, superoxide anion, and hydroxyl radical. In addition, the free radical generators led to loss of cell viability and elevated lipid peroxidation, while treatment with kimchi resulted in significantly increased cell viability and decreased lipid peroxidation. Furthermore, the protective effect against oxidative stress was related to regulation of cyclooxygenase-2, inducible nitric oxide synthase, nuclear factor-κB p65, and IκB expression. In particular, OvR showed the strongest protective effect from cellular oxidative stress among other kimchi. The current study indicated that kimchi, particularly OptR and OvR, played a protective role against free radical-induced oxidative stress. These findings suggest that kimchi is a promising functional food with an antioxidative effect and fermentation of kimchi led to elevation of antioxidative activity.

  20. NADH induces the generation of superoxide radicals in leaf peroxisomes. [Pisum sativum L

    Energy Technology Data Exchange (ETDEWEB)

    del Rio, L.A.; Sandalio, L.M.; Palma, J.M. (Unidad de Bioquimica Vegetal, Granada (Spain)); Fernandez, V.M.; Ruperez, F.L. (Instituto de Catalisis, Madrid (Spain))

    1989-03-01

    In peroxisomes isolated from pea leaves (Pisum sativum L.) the production of superoxide free radicals (O{sub 2}{sup {minus}}) by xanthine and NADH was investigated. In peroxisomal membranes, 100 micromolar NADH induced the production of O{sub 2}{sup {minus}} radicals. In the soluble fractions of peroxisomes, no generation of O{sub 2}{sup {minus}} radicals was observed by incubation with either NADH or xanthine, although xanthine oxidase was found located predominantly in the matrix of peroxisomes. The failure of xanthine to induce superoxide generation was probably due to the inability to fully suppress the endogenous Mn-superoxide dismutase activity by inhibitors which were inactive against xanthine oxidase. The generation of superoxide radicals in leaf peroxisomes together with the recently described production of these oxygen radicals in glyoxysomes suggests that O{sub 2}{sup {minus}} generation could be a common metabolic property of peroxisomes and further supports the existence of active oxygen-related roles for peroxisomes in cellular metabolism.

  1. 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...

  2. Effect of preoperative chemotherapy and radiation therapy during and after radical operation for esophageal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Nakamichi, Sonoko; Fujino, Yuji; Taenaka, Nobuyuki; Yoshiya, Ikuto; Murata, Atsuo [Osaka Univ., Suita (Japan). Hospital

    1997-10-01

    The effect of preoperative chemotherapy and radiation therapy (CR therapy) on peri- and postoperative circulatory and respiratory status was studied retrospectively. Forty-two patients of esophageal cancer who had radical operation were included in this study. Twelve patients had CR therapy before operation (group CR) and 30 patients without CR (group N). During the operation there was more bleeding in group CR than in group N, necessitating more intraoperative blood transfusion in group CR. Body weight of group CR increased more than that of group N from the 1st to the 4th postoperative day. AaDo{sub 2} also increased in group CR on the 1st postoperative day, which was thought to reflect an increase in water in the lungs. Diuretics required during the postoperative period did not show difference between both groups. Plasma IL-6 level was lower in group CR than in group N, although there was no statistical significance. No patients died in both groups. In conclusion, postoperative body weight and AaDo{sub 2} in group CR increased more than those in group N. (author)

  3. Radiation induced fracture of the scapula

    Energy Technology Data Exchange (ETDEWEB)

    Riggs, J.H. III; Schultz, G.D.; Hanes, S.A. (Los Angeles College of Chiropractic, Whittier, CA (USA))

    1990-10-01

    A case of radiation induced osteonecrosis resulting in a fracture of the scapula in a 76-yr-old female patient with a history of breast carcinoma is presented. Diagnostic imaging, laboratory recommendations and clinical findings are discussed along with an algorithm for the safe management of patients with a history of cancer and musculoskeletal complaints. This case demonstrates the necessity of a thorough investigation of musculoskeletal complaints in patients with previous bone-seeking carcinomas.

  4. Study of chemical and radiation induced carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Chmura, A.

    1995-11-01

    The study of chemical and radiation induced carcinogenesis has up to now based many of its results on the detection of genetic aberrations using the fluorescent in situ hybridization (FISH) technique. FISH is time consuming and this tends to hinder its use for looking at large numbers of samples. We are currently developing new technological advances which will increase the speed, clarity and functionality of the FISH technique. These advances include multi-labeled probes, amplification techniques, and separation techniques.

  5. Heat pump processes induced by laser radiation

    Science.gov (United States)

    Garbuny, M.; Henningsen, T.

    1980-01-01

    A carbon dioxide laser system was constructed for the demonstration of heat pump processes induced by laser radiation. The system consisted of a frequency doubling stage, a gas reaction cell with its vacuum and high purity gas supply system, and provisions to measure the temperature changes by pressure, or alternatively, by density changes. The theoretical considerations for the choice of designs and components are dicussed.

  6. Coumestan inhibits radical-induced oxidation of DNA: is hydroxyl a necessary functional group?

    Science.gov (United States)

    Xi, Gao-Lei; Liu, Zai-Qun

    2014-06-18

    Coumestan is a natural tetracycle with a C═C bond shared by a coumarin moiety and a benzofuran moiety. In addition to the function of the hydroxyl group on the antioxidant activity of coumestan, it is worth exploring the influence of the oxygen-abundant scaffold on the antioxidant activity as well. In this work, seven coumestans containing electron-withdrawing and electron-donating groups were synthesized to evaluate the abilities to trap 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS(•+)), 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), and galvinoxyl radical, respectively, and to inhibit the oxidations of DNA mediated by (•)OH, Cu(2+)/glutathione (GSH), and 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH), respectively. It was found that all of the coumestans used herein can quench the aforementioned radicals and can inhibit (•)OH-, Cu(2+)/GSH-, and AAPH-induced oxidations of DNA. In particular, substituent-free coumestan exhibits higher ability to quench DPPH and to inhibit AAPH-induced oxidation of DNA than Trolox. In addition, nonsubstituted coumestan shows a similar ability to inhibit (•)OH- and Cu(2+)/GSH-induced oxidations of DNA relative to that of Trolox. The antioxidant effectiveness of the coumestan can be attributed to the lactone in the coumarin moiety and, therefore, a hydroxyl group may not be a necessary functional group for coumestan to be an antioxidant.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kandasamy, S.B.; Hunt, W.A.; Harris, A.H. (Armed Forces Radiobiology Research Institute, Bethesda, MD (USA))

    1991-05-01

    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.

  8. Separation of photo-induced radical pair in cryptochrome to a functionally critical distance

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Domratcheva, Tatiana; Schulten, Klaus

    2014-01-01

    Cryptochrome is a blue light receptor that acts as a sensor for the geomagnetic field and assists many animals in long-range navigation. The magnetoreceptor function arises from light-induced formation of a radical pair through electron transfer between a flavin cofactor (FAD) and a triad...... of tryptophan residues. Here, this electron transfer is investigated by quantum chemical and classical molecular dynamics calculations. The results reveal how sequential electron transfer, assisted by rearrangement of polar side groups in the cryptochrome interior, can yield a FAD-Trp radical pair state...... with the FAD and Trp partners separated beyond a critical distance. The large radical pair separation reached establishes cryptochrome's sensitivity to the geomagnetic field through weakening of distance-dependent exchange and dipole-dipole interactions. It is estimated that the key secondary electron transfer...

  9. Impact of induced levels of specific free radicals and malondialdehyde on chicken semen quality and fertility.

    Science.gov (United States)

    Rui, Bruno R; Shibuya, Fábio Y; Kawaoku, Allison J T; Losano, João D A; Angrimani, Daniel S R; Dalmazzo, Andressa; Nichi, Marcilio; Pereira, Ricardo J G

    2017-03-01

    Over the past decades, scientists endeavored to comprehend oxidative stress in poultry spermatozoa and its relationship with fertilizing ability, lipid peroxidation (LPO), free-radical scavenging systems, and antioxidant therapy. Although considerable progress has been made, further improvement is needed in understanding how specific reactive oxygen species (ROS) and malondialdehyde (MDA, a toxic byproduct of LPO) disrupt organelles in avian spermatozoon. Hence, this study examined functional changes in chicken spermatozoa after incubation with different ROS, and their implications for the fertility. First, semen samples from 14 roosters were individually diluted and aliquoted into five equal parts: control, superoxide anion, hydrogen peroxide (H2O2), hydroxyl radicals, and MDA. After incubation with these molecules, aliquots were analyzed for motility, plasma membrane and acrosome integrity, mitochondrial activity, and LPO and DNA damage. Hydrogen peroxide was more detrimental for sperm motility than hydroxyl radicals, whereas the superoxide anion and MDA exhibited no differences compared with controls. In turn, plasma membrane and acrosome integrity, mitochondrial activity, LPO and DNA integrity rates were only affected by hydroxyl radicals. Thereafter, semen aliquots were incubated under the same conditions and used for artificial insemination. In accordance to our in vitro observations, H2O2 and hydroxyl radicals sharply reduced egg fertility, whereas superoxide anion and MDA only induced slight declines. Thus, chicken sperm function was severely impaired by H2O2 and hydroxyl radicals, but their mechanisms of action seemingly comprise different pathways. Further analysis regarding susceptibility of spermatozoon organelles to specific radicals in other poultry will help us to understand the development of interspecific differences in scavenging systems and to outline more oriented antioxidant approaches. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Hydroxyl radical-induced degradation of fenuron in pulse and gamma radiolysis: kinetics and product analysis.

    Science.gov (United States)

    Kovács, Krisztina; Mile, Viktoria; Csay, Tamás; Takács, Erzsébet; Wojnárovits, László

    2014-11-01

    Radiolytic reactions of phenylureas were studied in detail with fenuron model compound in dilute aqueous solutions using pulse radiolysis for detection of the intermediates, gamma radiolysis with UV-Vis and HPLC-MS techniques for analysis of the final products. The kinetics of oxidation was followed by COD, TOC and toxicity measurements. During radiolysis of aerated solutions hydroxyl radical ((•)OH), eaq (-), H(•) and O2 (•-)/HO2 (•) reactive intermediates are produced, the degradation of solute takes place practically entirely through (•)OH reactions. Therefore, the product distribution is similar to the distributions reported in other advanced oxidation processes with (•)OH as main reactant. (•)OH mainly reacts with the aromatic ring, forming cyclohexadienyl radical as an intermediate. This radical in pulse radiolysis has a wide absorption band in the 310-390 nm wavelength range with a maximum at 350 nm. Cyclohexadienyl radical reacts with dissolved O2 with a rate coefficient of ∼ 4 × 10(8) mol(-1) dm(3) s(-1) forming peroxy radical. The latter may eliminate HO2 (•) giving phenols or undergoes fragmentation. The one-electron oxidant (•)OH on average induces more than two-electron oxidations. The toxicity first increases with absorbed dose, then decreases. This increase is partly due to phenols formed during the first degradation period.

  11. VEGF secretion during hypoxia depends on free radicals-induced Fyn kinase activity in mast cells

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Roman, Jonathan; Ibarra-Sanchez, Alfredo; Lamas, Monica [Departamento de Farmacobiologia, Centro de Investigacion y de Estudios Avanzados del IPN (Cinvestav, IPN) (Mexico); Gonzalez Espinosa, Claudia, E-mail: cgonzal@cinvestav.mx [Departamento de Farmacobiologia, Centro de Investigacion y de Estudios Avanzados del IPN (Cinvestav, IPN) (Mexico)

    2010-10-15

    Research highlights: {yields} Bone marrow-derived mast cells (BMMCs) secrete functional VEGF but do not degranulate after Cobalt chloride-induced hypoxia. {yields} CoCl{sub 2}-induced VEGF secretion in mast cells occurs by a Ca{sup 2+}-insensitive but brefeldin A and Tetanus toxin-sensitive mechanism. {yields} Trolox and N-acetylcysteine inhibit hypoxia-induced VEGF secretion but only Trolox inhibits Fc{epsilon}RI-dependent anaphylactic degranulation in mast cells. {yields} Src family kinase Fyn activation after free radical production is necessary for hypoxia-induced VEGF secretion in mast cells. -- Abstract: Mast cells (MC) have an important role in pathologic conditions such as asthma and chronic obstructive pulmonary disease (COPD), where hypoxia conduce to deleterious inflammatory response. MC contribute to hypoxia-induced angiogenesis producing factors such as vascular endothelial growth factor (VEGF), but the mechanisms behind the control of hypoxia-induced VEGF secretion in this cell type is poorly understood. We used the hypoxia-mimicking agent cobalt chloride (CoCl{sub 2}) to analyze VEGF secretion in murine bone marrow-derived mast cells (BMMCs). We found that CoCl{sub 2} promotes a sustained production of functional VEGF, able to induce proliferation of endothelial cells in vitro. CoCl{sub 2}-induced VEGF secretion was independent of calcium rise but dependent on tetanus toxin-sensitive vesicle-associated membrane proteins (VAMPs). VEGF exocytosis required free radicals formation and the activation of Src family kinases. Interestingly, an important deficiency on CoCl{sub 2}-induced VEGF secretion was observed in Fyn kinase-deficient BMMCs. Moreover, Fyn kinase was activated by CoCl{sub 2} in WT cells and this activation was prevented by treatment with antioxidants such as Trolox and N-acetylcysteine. Our results show that BMMCs are able to release VEGF under hypoxic conditions through a tetanus toxin-sensitive mechanism, promoted by free radicals

  12. Quantitative measurement of hydroxyl radical induced DNA double-strand breaks and the effect of N-acetyl-L-cysteine.

    Science.gov (United States)

    Su, Meihong; Yang, Yao; Yang, Guoliang

    2006-07-24

    Reactive oxygen species, such as hydroxyl or superoxide radicals, can be generated by exogenous agents as well as from normal cellular metabolism. Those radicals are known to induce various lesions in DNA, including strand breaks and base modifications. These lesions have been implicated in a variety of diseases such as cancer, arteriosclerosis, arthritis, neurodegenerative disorders and others. To assess these oxidative DNA damages and to evaluate the effects of the antioxidant N-acetyl-L-cysteine (NAC), atomic force microscopy (AFM) was used to image DNA molecules exposed to hydroxyl radicals generated via Fenton chemistry. AFM images showed that the circular DNA molecules became linear after incubation with hydroxyl radicals, indicating the development of double-strand breaks. The occurrence of the double-strand breaks was found to depend on the concentration of the hydroxyl radicals and the duration of the reaction. Under the conditions of the experiments, NAC was found to exacerbate the free radical-induced DNA damage.

  13. Hormonal changes after localized prostate cancer treatment. Comparison between external beam radiation therapy and radical prostatectomy.

    Science.gov (United States)

    Planas, J; Celma, A; Placer, J; Maldonado, X; Trilla, E; Salvador, C; Lorente, D; Regis, L; Cuadras, M; Carles, J; Morote, J

    2016-11-01

    To determine the influence of radical prostatectomy (RP) and external beam radiation therapy (EBRT) on the hypothalamic pituitary axis of 120 men with clinically localized prostate cancer treated with RP or EBRT exclusively. 120 patients with localized prostate cancer were enrolled. Ninety two patients underwent RP and 28 patients EBRT exclusively. We measured serum levels of luteinizing hormone, follicle stimulating hormone (FSH), total testosterone (T), free testosterone, and estradiol at baseline and at 3 and 12 months after treatment completion. Patients undergoing RP were younger and presented a higher prostate volume (64.3 vs. 71.1 years, p<0.0001 and 55.1 vs. 36.5 g, p<0.0001; respectively). No differences regarding serum hormonal levels were found at baseline. Luteinizing hormone and FSH levels were significantly higher in those patients treated with EBRT at three months (luteinizing hormone 8,54 vs. 4,76 U/l, FSH 22,96 vs. 8,18 U/l, p<0,0001) while T and free testosterone levels were significantly lower (T 360,3 vs. 414,83ng/dl, p 0,039; free testosterone 5,94 vs. 7,5pg/ml, p 0,018). At 12 months FSH levels remained significantly higher in patients treated with EBRT compared to patients treated with RP (21,01 vs. 8,51 U/l, p<0,001) while T levels remained significantly lower (339,89 vs. 402,39ng/dl, p 0,03). Prostate cancer treatment influences the hypothalamic pituitary axis. This influence seems to be more important when patients with prostate cancer are treated with EBRT rather than RP. More studies are needed to elucidate the role that prostate may play as an endocrine organ. Copyright © 2016 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. Analysis of loco-regional failures in head and neck cancer after radical radiation therapy.

    Science.gov (United States)

    De Felice, Francesca; Thomas, Christopher; Barrington, Sally; Pathmanathan, Angela; Lei, Mary; Urbano, Teresa Guerrero

    2015-11-01

    To investigate the anatomical distribution of loco-regional treatment failures (LRF) in patients with head and neck squamous cell carcinoma (HNSCC) in relation to clinical target volume (CTV) delineation. 56 patients with LRF were retrospectively identified. Patients were previously treated with radical intensity modulated radiotherapy (IMRT) +/- chemotherapy. Target volumes include gross tumour volume (GTV), its volumetric expansion of 10mm (GTV-HD), CTV high dose (CTV-HD) delineated by anatomic expansion from GTV and CTV low dose (CTV-LD) defined to receive a prophylactic dose. LRF were evaluated by PET-CT or CT scan. We analysed the association between sites of LRF and target volumes and dosimetry, using image co-registration. Based on percentage of volume that received 95% of prescribed dose, LRF were classified as in-field, marginal or out-field. Median interval time from end of treatment to LRF was 186days. 65 (95.6%) LRF were classified as in-field. Considering primary target volumes, 40 (58.8%) LRF occurred inside GTV, 13 (19.1%) in GTV-HD and 7 (10.3%) in CTV-HD. The overall 1-year and 2-year post-failure survival (PFS) was 45.8% and 24.2%, respectively. Post radiation LRF managed with salvage surgery had a significantly higher median PFS when compared with palliative treatments (p=0.003). The majority of LRF occurred within GTV/GTV-HD, suggesting it is safe to reduce the CTV to a volumetric expansion. Given the low incidence of geographical misses, future studies should be directed towards dose escalation of high-risk volumes. Potential reduction of RT-related toxicity with volumetric expansion could facilitate salvage surgery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Radiation-induced esophagitis in lung cancer

    Directory of Open Access Journals (Sweden)

    Baker S

    2016-10-01

    Full Text Available Sarah Baker, Alysa Fairchild Department of Radiation Oncology, Cross Cancer Institute, University of Alberta, Edmonton, AB, Canada Abstract: Radiation-induced esophagitis is the most common local acute toxicity of radiotherapy (RT delivered for the curative or palliative intent treatment of lung cancer. Although concurrent chemotherapy and higher RT dose are associated with increased esophagitis risk, advancements in RT techniques as well as adherence to esophageal dosimetric constraints may reduce the incidence and severity. Mild acute esophagitis symptoms are generally self-limited, and supportive management options include analgesics, acid suppression, diet modification, treatment for candidiasis, and maintenance of adequate nutrition. Esophageal stricture is the most common late sequela from esophageal irradiation and can be addressed with endoscopic dilatation. Approaches to prevent or mitigate these toxicities are also discussed. Keywords: non–small cell lung cancer, acute, late, toxicity, stricture

  16. ACE inhibition attenuates radiation-induced cardiopulmonary damage

    NARCIS (Netherlands)

    van der Veen, Sonja J.; Ghobadi, Ghazaleh; de Boer, Rudolf A; Faber, Hette; Cannon, Megan V; Nagle, Peter W; Brandenburg, Sytze; Langendijk, Johannes A; van Luijk, Peter; Coppes, Robert P

    BACKGROUND AND PURPOSE: In thoracic irradiation, the maximum radiation dose is restricted by the risk of radiation-induced cardiopulmonary damage and dysfunction limiting tumor control. We showed that radiation-induced sub-clinical cardiac damage and lung damage in rats mutually interact and that

  17. Radiation induced erosion of autoelectron emitter surface

    CERN Document Server

    Mazilova, T I; Ksenofontov, V A

    2001-01-01

    The peculiarities of erosion of the needle-shaped autoemitter surface under the effect of the helium ions bombardment are studied. The analysis of the radiation-induced formation of the surface atomic roughness testifies to the nondynamic character of shifting the surface atoms by the ions energies below the threshold of the Frenkel stable pairs formation and cathode sputtering. The quasistatic mechanism of the surface erosion due to the atoms shift into the low-coordination positions by releasing the energy of the helium internodal atoms formation is discussed

  18. Radiation-induced esophagitis in lung cancer

    Science.gov (United States)

    Baker, Sarah; Fairchild, Alysa

    2016-01-01

    Radiation-induced esophagitis is the most common local acute toxicity of radiotherapy (RT) delivered for the curative or palliative intent treatment of lung cancer. Although concurrent chemotherapy and higher RT dose are associated with increased esophagitis risk, advancements in RT techniques as well as adherence to esophageal dosimetric constraints may reduce the incidence and severity. Mild acute esophagitis symptoms are generally self-limited, and supportive management options include analgesics, acid suppression, diet modification, treatment for candidiasis, and maintenance of adequate nutrition. Esophageal stricture is the most common late sequela from esophageal irradiation and can be addressed with endoscopic dilatation. Approaches to prevent or mitigate these toxicities are also discussed. PMID:28210168

  19. Influence of Cocoa Flavanols and Procyanidins on Free Radical-induced Human Erythrocyte Hemolysis

    Directory of Open Access Journals (Sweden)

    Qin Yan Zhu

    2005-01-01

    Full Text Available Cocoa can be a rich source of antioxidants including the flavan-3-ols, epicatechin and catechin, and their oligomers (procyanidins. While these flavonoids have been reported to reduce the rate of free radical-induced erythrocyte hemolysis in experimental animal models, little is known about their effect on human erythrocyte hemolysis. The major objective of this work was to study the effect of a flavonoid-rich cocoa beverage on the resistance of human erythrocytes to oxidative stress. A second objective was to assess the effects of select purified cocoa flavonoids, epicatechin, catechin, the procyanidin Dimer B2 and one of its major metabolites, 3ʹ-O-methyl epicatechin, on free radical-induced erythrocyte hemolysis in vitro. Peripheral blood was obtained from 8 healthy subjects before and 1, 2, 4 and 8 h after consuming a flavonoid-rich cocoa beverage that provided 0.25 g/kg body weight (BW, 0.375 or 0.50 g/kg BW of cocoa. Plasma flavanol and dimer concentrations were determined for each subject. Erythrocyte hemolysis was evaluated using a controlled peroxidation reaction. Epicatechin, catechin, 3ʹ-O-methyl epicatechin and (--epicatechin-(4β > 8epicatechin (Dimer B2 were detected in the plasma within 1 h after the consumption of the beverage. The susceptibility of erythrocytes to hemolysis was reduced significantly following the consumption of the beverages. The duration of the lag time, which reflects the capacity of cells to buffer free radicals, was increased. Consistent with the above, the purified flavonoids, epicatechin, catechin, Dimer B2 and the metabolite 3ʹ-O-methyl epicatechin, exhibited dose-dependent protection against AAPH-induced erythrocyte hemolysis at concentrations ranging from 2.5 to 20 μM. Erythrocytes from subjects consuming flavonoid-rich cocoa show reduced susceptibility to free radical-induced hemolysis (p < 0.05.

  20. γ-radiation induced corrosion of copper in bentonite-water systems under anaerobic conditions

    Science.gov (United States)

    Karin Norrfors, K.; Björkbacka, Åsa; Kessler, Amanda; Wold, Susanna; Jonsson, Mats

    2018-03-01

    In this work we have experimentally studied the impact of bentonite clay on the process of radiation-induced copper corrosion in anoxic water. The motivation for this is to further develop our understanding of radiation-driven processes occurring in deep geological repositories for spent nuclear fuel where copper canisters containing the spent nuclear fuel will be embedded in compacted bentonite. Experiments on radiation-induced corrosion in the presence and absence of bentonite were performed along with experiments elucidating the impact irradiation on the Cu2+ adsorption capacity of bentonite. The experiments presented in this work show that the presence of bentonite clay has no or very little effect on the magnitude of radiation-induced corrosion of copper in anoxic aqueous systems. The absence of a protective effect similar to that observed for radiation-induced dissolution of UO2 is attributed to differences in the corrosion mechanism. This provides further support for the previously proposed mechanism where the hydroxyl radical is the key radiolytic oxidant responsible for the corrosion of copper. The radiation effect on the bentonite sorption capacity of Cu2+ (reduced capacity) is in line with what has previously been reported for other cations. The reduced cation sorption capacity is partly attributed to a loss of Al-OH sites upon irradiation.

  1. Measurements of the OH radical in forested environments by laser-induced fluorescence

    Science.gov (United States)

    Bottorff, B.; Lew, M.; Stevens, P. S.

    2016-12-01

    The hydroxyl radical (OH) is one of the most important oxidants in the atmosphere. The OH radical initiates the oxidation of volatile organic compounds (VOCs) which in the presence of nitrogen oxides (NOx) can lead to the production of ozone and secondary organic aerosols. Recent studies have shown discrepancies between measured and modeled OH concentrations, especially in forested, low-NOx environments. Therefore, additional measurements of OH radical concentrations in these environments are needed to provide a better understanding of the impact of BVOC emissions on the chemistry of the troposphere. In this study, measurements of OH were made using the Laser-Induced Fluorescence-Fluorescence Assay by Gas Ecpansion (LIF-FAGE) technique during two field campaigns: the Indiana Radical Reactivity and Ozone Production Intercomparison (IRRONIC) in Bloomington, Indiana during July 2015 and the Program for Research on Oxidants Photochemistry and Transport - Atmospheric Measurements of Oxidants in Summer (PROPHET-AMOS) in Pellston, Michigan during July 2016. Both campaigns were conducted in forested environments characterized by high isoprene emissions and low NOx mixing ratios. Ambient OH measurements from both campaigns, including measurements of unknown interferences, will be discussed and compared to modeled predictions.

  2. Radar detection of radiation-induced ionization in air

    Science.gov (United States)

    Gopalsami, Nachappa; Heifetz, Alexander; Chien, Hual-Te; Liao, Shaolin; Koehl, Eugene R.; Raptis, Apostolos C.

    2015-07-21

    A millimeter wave measurement system has been developed for remote detection of airborne nuclear radiation, based on electromagnetic scattering from radiation-induced ionization in air. Specifically, methods of monitoring radiation-induced ionization of air have been investigated, and the ionized air has been identified as a source of millimeter wave radar reflection, which can be utilized to determine the size and strength of a radiation source.

  3. Predictors of urinary and rectal toxicity after external conformed radiation therapy in prostate cancer: Correlation between clinical, tumour and dosimetric parameters and radical and postoperative radiation therapy.

    Science.gov (United States)

    Martínez-Arribas, C M; González-San Segundo, C; Cuesta-Álvaro, P; Calvo-Manuel, F A

    2017-06-15

    To determine rectal and urinary toxicity after external beam radiation therapy (EBRT), assessing the results of patients who undergo radical or postoperative therapy for prostate cancer (pancreatic cancer) and their correlation with potential risk factors. A total of 333 patients were treated with EBRT. Of these, 285 underwent radical therapy and 48 underwent postoperative therapy (39 cases of rescue and 9 of adjuvant therapy). We collected clinical, tumour and dosimetric variable to correlate with toxicity parameters. We developed decision trees based on the degree of statistical significance. The rate of severe acute toxicity, both urinary and rectal, was 5.4% and 1.5%, respectively. The rate of chronic toxicity was 4.5% and 2.7%, respectively. Twenty-seven patients presented haematuria, and 9 presented haemorrhagic rectitis. Twenty-five patients (7.5%) presented permanent limiting sequela. The patients with lower urinary tract symptoms prior to the radiation therapy presented poorer tolerance, with greater acute bladder toxicity (P=0.041). In terms of acute rectal toxicity, 63% of the patients with mean rectal doses >45Gy and anticoagulant/antiplatelet therapy developed mild toxicity compared with 37% of the patients with mean rectal doses <45 Gy and without anticoagulant therapy. We were unable to establish predictors of chronic toxicity in the multivariate analysis. The long-term sequelae were greater in the patients who underwent urological operations prior to the radiation therapy and who were undergoing anticoagulant therapy. The tolerance to EBRT was good, and severe toxicity was uncommon. Baseline urinary symptoms constitute the predictor that most influenced the acute urinary toxicity. Rectal toxicity is related to the mean rectal dose and with anticoagulant/antiplatelet therapy. There were no significant differences in severe toxicity between radical versus postoperative radiation therapy. Copyright © 2017 AEU. Publicado por Elsevier España, S

  4. In vivo generation of hydroxyl radicals and MPTP-induced dopaminergic toxicity in the basal ganglia.

    Science.gov (United States)

    Chiueh, C C; Wu, R M; Mohanakumar, K P; Sternberger, L M; Krishna, G; Obata, T; Murphy, D L

    1994-11-17

    The in vivo generation of .OH free radicals in specific brain regions can be measured by intracerebral microdialysis perfusion of salicylate, avoiding many of the pitfalls inherent in systemic administration of salicylate. Direct infusion of salicylate into the brain can minimize the hepatic hydroxylation of salicylate and its contribution to brain levels of 2,5-DHBA. Levels of 2,5-DHBA detected in the brain dialysate may reflect the .OH adduct plus some enzymatic hydroxylation of salicylate in the brain. After minimizing the contribution of enzyme and/or blood-borne 2,5-DHBA, the present data demonstrate the validity of the use of 2,3-DHBA and apparently 2,5-DHBA as indices of .OH formation in the brain. Therefore, intracranial microdialysis of salicylic acid and measurement of 2,3-DHBA appears to be a useful .OH trapping procedure for monitoring the time course of .OH generation in the extracellular fluid of the brain. These results indicate that nonenzymatic and/or enzymatic oxidation of the dopamine released by MPTP analogues in the extracellular fluid may play a key role in the generation of .OH free radicals in the iron-rich basal ganglia. Moreover, a site-specific generation of cytotoxic .OH free radicals and quinone/semiquinone radicals in the striatum may cause the observed lipid peroxidation, calcium overload, and retrograde degeneration of nigrostriatal neurons. This free-radical-induced nigral injury can be suppressed by antioxidants (i.e., U-78517F, DMSO, and deprenyl) and possibly hypothermia as well. In the future, this in vivo detection of .OH generation may be useful in answering some of the fundamental questions concerning the relevance of oxidants and antioxidants in neurodegenerative disorders during aging. It could also pave the way for the research and development of novel neuroprotective antioxidants and strategies for the early or preventive treatment of neurodegenerative disorders, such as Parkinson's disease (Wu et al., this issue

  5. Hydroxyl radical induced oxidation of theophylline in water: a kinetic and mechanistic study.

    Science.gov (United States)

    Sunil Paul, M M; Aravind, U K; Pramod, G; Saha, A; Aravindakumar, C T

    2014-08-14

    Oxidative destruction and mineralization of emerging organic pollutants by hydroxyl radicals (˙OH) is a well established area of research. The possibility of generating hazardous by-products in the case of ˙OH reaction demands extensive investigations on the degradation mechanism. A combination of pulse radiolysis and steady state photolysis (H2O2/UV photolysis) followed by high resolution mass spectrometric (HRMS) analysis have been employed to explicate the kinetic and mechanistic features of the destruction of theophylline, a model pharmaceutical compound and an identified pollutant, by ˙OH in the present study. The oxidative destruction of this molecule, for intermediate product studies, was initially achieved by H2O2/UV photolysis. The transient absorption spectrum corresponding to the reaction of ˙OH with theophylline at pH 6, primarily caused by the generation of (T8-OH)˙, was characterised by an absorption band at 330 nm (k2 = (8.22 ± 0.03) × 10(9) dm(3) mol(-1) s(-1)). A significantly different spectrum (λmax: 340 nm) was observed at highly alkaline pH (10.2) due to the deprotonation of this radical (pKa∼ 10.0). Specific one electron oxidants such as sulphate radical anions (SO4˙(-)) and azide radicals (N3˙) produce the deprotonated form (T(-H)˙) of the radical cation (T˙(+)) of theophylline (pKa 3.1) with k2 values of (7.51 ± 0.04) × 10(9) dm(3) mol(-1) s(-1) and (7.61 ± 0.02) × 10(9) dm(3) mol(-1) s(-1) respectively. Conversely, oxide radicals (O˙(-)) react with theophylline via a hydrogen abstraction protocol with a rather slow k2 value of (1.95 ± 0.02) × 10(9) dm(3) mol(-1) s(-1). The transient spectral studies were complemented by the end product profile acquired by HRMS analysis. Various transformation products of theophylline induced by ˙OH were identified by this technique which include derivatives of uric acids (i, iv & v) and xanthines (ii, iii & vi). Further breakdown of the early formed product due to ˙OH attack leads to

  6. Antioxidant Activity of Caffeic Acid against Iron-Induced Free Radical Generation--A Chemical Approach.

    Science.gov (United States)

    Genaro-Mattos, Thiago C; Maurício, Ângelo Q; Rettori, Daniel; Alonso, Antonio; Hermes-Lima, Marcelo

    2015-01-01

    Caffeic acid (CA) is a phenolic compound widely found in coffee beans with known beneficial effects in vivo. Many studies showed that CA has anti-inflammatory, anti-mutagenic, antibacterial and anti-carcinogenic properties, which could be linked to its antioxidant activity. Taking in consideration the reported in vitro antioxidant mechanism of other polyphenols, our working hypothesis was that the CA antioxidant activity could be related to its metal-chelating property. With that in mind, we sought to investigate the chemical antioxidant mechanism of CA against in vitro iron-induced oxidative damage under different assay conditions. CA was able to prevent hydroxyl radical formation promoted by the classical Fenton reaction, as determined by 2-deoxyribose (2-DR) oxidative degradation and DMPO hydroxylation. In addition to its ability to prevent hydroxyl radical formation, CA had a great inhibition of membrane lipid peroxidation. In the lipid peroxidation assays CA acted as both metal-chelator and as hydrogen donor, preventing the deleterious action promoted by lipid-derived peroxyl and alkoxyl radicals. Our results indicate that the observed antioxidant effects were mostly due to the formation of iron-CA complexes, which are able to prevent 2-DR oxidation and DMPO hydroxylation. Noteworthy, the formation of iron-CA complexes and prevention of oxidative damage was directly related to the pH of the medium, showing better antioxidant activity at higher pH values. Moreover, in the presence of lipid membranes the antioxidant potency of CA was much higher, indicating its enhanced effectiveness in a hydrophobic environment. Overall, our results show that CA acts as an antioxidant through an iron chelating mechanism, preventing the formation of free hydroxyl radicals and, therefore, inhibiting Fenton-induced oxidative damage. The chemical properties of CA described here--in association with its reported signaling effects--could be an explanation to its beneficial effects

  7. Antioxidant Activity of Caffeic Acid against Iron-Induced Free Radical Generation—A Chemical Approach

    Science.gov (United States)

    Genaro-Mattos, Thiago C.; Maurício, Ângelo Q.; Rettori, Daniel; Alonso, Antonio; Hermes-Lima, Marcelo

    2015-01-01

    Caffeic acid (CA) is a phenolic compound widely found in coffee beans with known beneficial effects in vivo. Many studies showed that CA has anti-inflammatory, anti-mutagenic, antibacterial and anti-carcinogenic properties, which could be linked to its antioxidant activity. Taking in consideration the reported in vitro antioxidant mechanism of other polyphenols, our working hypothesis was that the CA antioxidant activity could be related to its metal-chelating property. With that in mind, we sought to investigate the chemical antioxidant mechanism of CA against in vitro iron-induced oxidative damage under different assay conditions. CA was able to prevent hydroxyl radical formation promoted by the classical Fenton reaction, as determined by 2-deoxyribose (2-DR) oxidative degradation and DMPO hydroxylation. In addition to its ability to prevent hydroxyl radical formation, CA had a great inhibition of membrane lipid peroxidation. In the lipid peroxidation assays CA acted as both metal-chelator and as hydrogen donor, preventing the deleterious action promoted by lipid-derived peroxyl and alkoxyl radicals. Our results indicate that the observed antioxidant effects were mostly due to the formation of iron-CA complexes, which are able to prevent 2-DR oxidation and DMPO hydroxylation. Noteworthy, the formation of iron-CA complexes and prevention of oxidative damage was directly related to the pH of the medium, showing better antioxidant activity at higher pH values. Moreover, in the presence of lipid membranes the antioxidant potency of CA was much higher, indicating its enhanced effectiveness in a hydrophobic environment. Overall, our results show that CA acts as an antioxidant through an iron chelating mechanism, preventing the formation of free hydroxyl radicals and, therefore, inhibiting Fenton-induced oxidative damage. The chemical properties of CA described here—in association with its reported signaling effects—could be an explanation to its beneficial effects

  8. Antioxidant Activity of Caffeic Acid against Iron-Induced Free Radical Generation--A Chemical Approach.

    Directory of Open Access Journals (Sweden)

    Thiago C Genaro-Mattos

    Full Text Available Caffeic acid (CA is a phenolic compound widely found in coffee beans with known beneficial effects in vivo. Many studies showed that CA has anti-inflammatory, anti-mutagenic, antibacterial and anti-carcinogenic properties, which could be linked to its antioxidant activity. Taking in consideration the reported in vitro antioxidant mechanism of other polyphenols, our working hypothesis was that the CA antioxidant activity could be related to its metal-chelating property. With that in mind, we sought to investigate the chemical antioxidant mechanism of CA against in vitro iron-induced oxidative damage under different assay conditions. CA was able to prevent hydroxyl radical formation promoted by the classical Fenton reaction, as determined by 2-deoxyribose (2-DR oxidative degradation and DMPO hydroxylation. In addition to its ability to prevent hydroxyl radical formation, CA had a great inhibition of membrane lipid peroxidation. In the lipid peroxidation assays CA acted as both metal-chelator and as hydrogen donor, preventing the deleterious action promoted by lipid-derived peroxyl and alkoxyl radicals. Our results indicate that the observed antioxidant effects were mostly due to the formation of iron-CA complexes, which are able to prevent 2-DR oxidation and DMPO hydroxylation. Noteworthy, the formation of iron-CA complexes and prevention of oxidative damage was directly related to the pH of the medium, showing better antioxidant activity at higher pH values. Moreover, in the presence of lipid membranes the antioxidant potency of CA was much higher, indicating its enhanced effectiveness in a hydrophobic environment. Overall, our results show that CA acts as an antioxidant through an iron chelating mechanism, preventing the formation of free hydroxyl radicals and, therefore, inhibiting Fenton-induced oxidative damage. The chemical properties of CA described here--in association with its reported signaling effects--could be an explanation to its

  9. Operative treatment of radiation-induced fistulae

    Energy Technology Data Exchange (ETDEWEB)

    Balslev, I.; Harling, H.

    1987-01-01

    Out of 136 patients with radiation-induced intestinal complications, 45 had fistulae. Twenty-eight patients had rectovaginal fistulae while the remainder had a total of 13 different types of fistulae. Thirty-seven patients were treated operatively and eight were treated conservatively. Thirty-three patients were submitted to operation for rectal fistulae. Of these, 28 were treated by defunctioning colostomy, three were treated by Hartmann's method and resection and primary anastomosis was carried out in two patients. In the course of the period of observation, 35% of the patients developed new radiation damage. The frequency in the basic material without fistulae was 21% (0.05

  10. A case of radiation induced cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ozawa, Kazuyoshi; Tsuchikawa, Kohzo; Sato, Akira; Kato, Joji (Nippon Dental Univ., Niigata (Japan). School of Dentistry at Niigata)

    1994-06-01

    A case of carcinoma on the right buccal mucosa is presented. The case was suspected to have been induced by irradiation therapy for a carcinoma on the left buccal mucosa. An external radiotherapy, 6-MeV Linac, had been done for the carcinoma on the left buccal mucosa in a 55-year-old female, with single lateral direction from the left to the right in 1977. In 1985, a papillary lesion on the right buccal mucosa was detected, and histological examination revealed a papilloma without atypism. In 1991, as an ulcer on the right upper buccal fold as well as three papillary lesions in the central portion of the right buccal mucosa were found, the patient was referred to our clinic. Microscopical findings were consistent with the early invasive carcinomas. A surgical excision of these whole lesions and skin graft were completed. The criteria of this case for the suspicion of radiation-induced carcinoma were as follows. There was a long latent period of 14 years. The previous dose of irradiation, 60 Gy, was sufficient. The right buccal mucosa was involved in the radiation field. A severe scar on the left cheek resulted from the previous irradiation. Anatomically, there is no evidence of the secondary carcinoma on the right buccal mucosa with the primary carcinoma on the left buccal mucosa. No evidence for recurrence of the tumors on both sides of buccal mucosa has been detected so far. Further observations will be necessary to detect other tumors in the irradiated field later on. (author).

  11. A Novel High-Throughput Approach to Measure Hydroxyl Radicals Induced by Airborne Particulate Matter

    Directory of Open Access Journals (Sweden)

    Yeongkwon Son

    2015-10-01

    Full Text Available Oxidative stress is one of the key mechanisms linking ambient particulate matter (PM exposure with various adverse health effects. The oxidative potential of PM has been used to characterize the ability of PM induced oxidative stress. Hydroxyl radical (•OH is the most destructive radical produced by PM. However, there is currently no high-throughput approach which can rapidly measure PM-induced •OH for a large number of samples with an automated system. This study evaluated four existing molecular probes (disodium terephthalate, 3′-p-(aminophenylfluorescein, coumarin-3-carboxylic acid, and sodium benzoate for their applicability to measure •OH induced by PM in a high-throughput cell-free system using fluorescence techniques, based on both our experiments and on an assessment of the physicochemical properties of the probes reported in the literature. Disodium terephthalate (TPT was the most applicable molecular probe to measure •OH induced by PM, due to its high solubility, high stability of the corresponding fluorescent product (i.e., 2-hydroxyterephthalic acid, high yield compared with the other molecular probes, and stable fluorescence intensity in a wide range of pH environments. TPT was applied in a high-throughput format to measure PM (NIST 1648a-induced •OH, in phosphate buffered saline. The formed fluorescent product was measured at designated time points up to 2 h. The fluorescent product of TPT had a detection limit of 17.59 nM. The soluble fraction of PM contributed approximately 76.9% of the •OH induced by total PM, and the soluble metal ions of PM contributed 57.4% of the overall •OH formation. This study provides a promising cost-effective high-throughput method to measure •OH induced by PM on a routine basis.

  12. Effect of γ-radiation on free radicals formation, structural changes and functional properties of wheat starch.

    Science.gov (United States)

    Atrous, Hager; Benbettaieb, Nasreddine; Hosni, Faouzi; Danthine, Sabine; Blecker, Christophe; Attia, Hamadi; Ghorbel, Dorra

    2015-09-01

    Wheat starch was treated by different γ-radiation doses (3, 5, 10, 20, 35 and 50 kGy). The effects of γ-radiation on structural, thermal, physicochemical, morphological and rheological properties of wheat starch were studied. The presence of free radicals after γ-radiation treatment, which number decreased with time was confirmed. Structural analysis revealed decreases in the intensities of the O-H and C-H stretches and glycosidic linkages indicating the depolymerization of amylose and probably amylopectin into shorter chain molecules, but showed that γ-radiation treatment did not affect the crystalline structure. Differential scanning calorimetric (DSC) thermograms showed the absence of significant differences in the gelatinization temperatures, as well as the corresponding transition enthalpies since the DSC parameters are related to the crystalline ordering within the granules. Apparent amylose content decreased linearly with increasing irradiation dose leading to an increase in water solubility index. An increase in the swelling power was observed after irradiation treatment until 20 kGy, followed by a rapid decrease at higher doses. Microscopic observations showed that the effect of γ-radiation was more visible on starch pastes than on starch granules. Rheological properties of the starch pastes decreased with increasing irradiation dose as a result of glycosidic bond cleavage. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Clinical Outcomes of Image Guided Adaptive Hypofractionated Weekly Radiation Therapy for Bladder Cancer in Patients Unsuitable for Radical Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Hafeez, Shaista, E-mail: shaista.hafeez@icr.ac.uk [The Institute of Cancer Research, London (United Kingdom); The Royal Marsden NHS Foundation Trust, Sutton, Surrey (United Kingdom); McDonald, Fiona; Lalondrelle, Susan [The Royal Marsden NHS Foundation Trust, Sutton, Surrey (United Kingdom); McNair, Helen; Warren-Oseni, Karole; Jones, Kelly [The Institute of Cancer Research, London (United Kingdom); The Royal Marsden NHS Foundation Trust, Sutton, Surrey (United Kingdom); Harris, Victoria [The Royal Marsden NHS Foundation Trust, Sutton, Surrey (United Kingdom); Taylor, Helen; Khoo, Vincent [The Royal Marsden NHS Foundation Trust, London (United Kingdom); Thomas, Karen [The Royal Marsden NHS Foundation Trust, Sutton, Surrey (United Kingdom); Hansen, Vibeke; Dearnaley, David; Horwich, Alan; Huddart, Robert [The Institute of Cancer Research, London (United Kingdom); The Royal Marsden NHS Foundation Trust, Sutton, Surrey (United Kingdom)

    2017-05-01

    Purpose and Objectives: We report on the clinical outcomes of a phase 2 study assessing image guided hypofractionated weekly radiation therapy in bladder cancer patients unsuitable for radical treatment. Methods and Materials: Fifty-five patients with T2-T4aNx-2M0-1 bladder cancer not suitable for cystectomy or daily radiation therapy treatment were recruited. A “plan of the day” radiation therapy approach was used, treating the whole (empty) bladder to 36 Gy in 6 weekly fractions. Acute toxicity was assessed weekly during radiation therapy, at 6 and 12 weeks using the Common Terminology Criteria for Adverse Events version 3.0. Late toxicity was assessed at 6 months and 12 months using Radiation Therapy Oncology Group grading. Cystoscopy was used to assess local control at 3 months. Cumulative incidence function was used to determine local progression at 1 at 2 years. Death without local progression was treated as a competing risk. Overall survival was estimated using the Kaplan-Meier method. Results: Median age was 86 years (range, 68-97 years). Eighty-seven percent of patients completed their prescribed course of radiation therapy. Genitourinary and gastrointestinal grade 3 acute toxicity was seen in 18% (10/55) and 4% (2/55) of patients, respectively. No grade 4 genitourinary or gastrointestinal toxicity was seen. Grade ≥3 late toxicity (any) at 6 and 12 months was seen in 6.5% (2/31) and 4.3% (1/23) of patients, respectively. Local control after radiation therapy was 92% of assessed patients (60% total population). Cumulative incidence of local progression at 1 year and 2 years for all patients was 7% (95% confidence interval [CI] 2%-17%) and 17% (95% CI 8%-29%), respectively. Overall survival at 1 year was 63% (95% CI 48%-74%). Conclusion: Hypofractionated radiation therapy delivered weekly with a plan of the day approach offers good local control with acceptable toxicity in a patient population not suitable for radical bladder treatment.

  14. [Influence of monkshood root-peony root combination on inflamation-induced agents and free radicals].

    Science.gov (United States)

    Qin, L; Peng, X; Zhang, S H; Wang, L; Liu, F

    2000-06-01

    To find out the effect of monkshood root and peony root on inflammation-induced agents and free radicals when used separately and in combination. Two drugs were made into decoctions separately and in combination, i.p., qd, for 7 d, red blood cell SOD and serum LPO were analysed and the anti-inflammatory actions were observed. In an experimental rat model with inflamed paw edema induced by carrageenin or formaldehyde and in a mouse model with ear swelling induced by xylene, the anti-inflammatory effect appeared stronger when the two drugs were used in combination, especially in comparison with the use of monkshood root alone. The exudation of blood capillaries and the contents of inflammation medium PGE2 were lowered; The activity of SOD extracted from rat or mouse red blood cells was enhanced, and the serum LPO, which was high in level when monkshood root was used alone, could be declined when the two drugs were used in combination. The drug combination is more effective in inhibiting inflammation and scavenging free radicals.

  15. 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.

  16. The Effects of Small amounts of Methanol on the Ionizing Radiation Induced Polymerization and Photopolymerization of Styrene.

    Science.gov (United States)

    Tang, Fuh-Wei

    1990-08-01

    The mechanisms whereby ionizing radiation produce the species which initiate neutral free radical and ionic polymerization are investigated. Of particular interest is the remarkable enhancement effect on radiation induced polymerization of styrene by small concentrations of methanol. The approach is to compare the effects of methanol on the steady state polymerization of styrene induced by two different initiation methods: (1) gamma ray; (2) ultraviolet light (UV). In addition to these steady state reaction studies, microsecond pulse radiolysis with 6 MeV electrons is used to study the transient aspects of styrene polymerization and especially, the effect of methanol on the intiation step. The results for photopolymerization initiated with wavelengths above 280 nm, and therefore dominated by free radical polymerization, show that methanol has no sensitizing effect. This leads to eliminate the interaction between methanol and free radical in the initiation stage of a polymerization. By means of studies with different alcohols and an analysis of the dimer and trimer yield, a proton donor mechanism is successfully established for the enhancement effect of methanol on the radiation induced polymerization of styrene. The role of methanol is explained to serve as a rapid proton donor to the anion radical converting the latter to a neutral propagating free radical. The resulting methoxide anion then neutralizes the cation radical converting it to an additional neutral propagating free radical. Trace amounts of methanol (less than 0.05 M) in system with 2-3 mM water is found to have a desensitizing effect because of a quenching influence of methanol on propagating free ionic species; this effect is not observed in the water saturated (35 mM water) system or even at higher concentrations of methanol in the system with 3 mM water. In pulse radiolysis, a quantitative agreement between steady state polymerization and pulse radiolysis is for the first time obtained in the

  17. In situ AFM investigation of electrochemically induced surface-initiated atom-transfer radical polymerization.

    Science.gov (United States)

    Li, Bin; Yu, Bo; Zhou, Feng

    2013-02-12

    Electrochemically induced surface-initiated atom-transfer radical polymerization is traced by in situ AFM technology for the first time, which allows visualization of the polymer growth process. It affords a fundamental insight into the surface morphology and growth mechanism simultaneously. Using this technique, the polymerization kinetics of two model monomers were studied, namely the anionic 3-sulfopropyl methacrylate potassium salt (SPMA) and the cationic 2-(metharyloyloxy)ethyltrimethylammonium chloride (METAC). The growth of METAC is significantly improved by screening the ammonium cations by the addition of ionic liquid electrolyte in aqueous solution. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. 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 ...

  19. Ion beam induced luminescence: Relevance to radiation induced bystander effects

    Science.gov (United States)

    Ahmad, S. B.; McNeill, F. E.; Byun, S. H.; Prestwich, W. V.; Seymour, C.; Mothersill, C. E.

    2012-10-01

    The aim of this work is quantify the light emitted as a result of charged particle interaction in materials which may be of relevance to radiation induced "bystander effects" studies. We have developed a system which employs single photon counting to measure the light emitted from samples irradiated under vacuum by a charged particle beam. The system uses a fast photomultiplier tube with a peak cathode response at 420 nm. It has been tested in a proof-of-principle experiment using polystyrene targets. Light output, as a result of irradiation, was measured. The luminescence yield appears to have a non-linear behavior with the incident ion fluence: it rises exponentially to an asymptotic value. The target was irradiated with beam energies varying from 1 to 2 MeV and showed saturation at or before an incident fluence rate of 3 × 1013 H+/cm2 s. The average saturation value for the photon output was found to be 40 × 106 cps. Some measurements were performed using filters to study the emission at specific wavelengths. In the case of filtered light measurements, the photon output was found to saturate at 28 × 103, 10 × 106, and 35 × 106 cps for wavelengths of 280 ± 5 nm, 320 ± 5 nm and 340 ± 5 nm respectively. The light output reaches a maximum value because of damage induced in the polymer. Our measurements indicate a "damage cross section" of the order of 10-14 cm2. The average radiant intensity was found to increase at wavelengths of 280 and 320 nm when the proton energy was increased. This was not found to occur at 340 nm. In conclusion, the light emission at specific wavelengths was found to depend upon the incident proton fluence and the proton energy. The wavelengths of the emitted light measured in this study have significance for the understanding of radiation induced bystander effects.

  20. Treatment of radiation-induced cystitis with hyperbaric oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, J.P.; Boland, F.P.; Mori, H.; Gallagher, M.; Brereton, H.; Preate, D.L.; Neville, E.C.

    1985-08-01

    The effects of hyperbaric oxygen on radiation cystitis have been documented in 3 patients with radiation-induced hemorrhagic cystitis refractory to conventional therapy. Cessation of gross hematuria and reversal of cystoscopic bladder changes were seen in response to a series of hyperbaric oxygen treatments of 2 atmosphere absolute pressure for 2 hours. To our knowledge this is the first report of cystoscopically documented healing of radiation-induced bladder injury.

  1. Antioxidant activity of capsaicin on radiation-induced oxidation of murine hepatic mitochondrial membrane preparation

    Directory of Open Access Journals (Sweden)

    Gangabhagirathi R

    2015-06-01

    Full Text Available Ramachandran Gangabhagirathi,1 Ravi Joshi,2 1Bioorganic Division, 2Radiation and Photochemistry Division, Bhabha Atomic Research Center, Trombay, Mumbai, India Abstract: Capsaicin is the major capsaicinoid in chili peppers and is widely used as a spice. It is also used for topical applications in cases of peripheral neuropathy. The present study deals with its role in modulation of gamma radiation-induced damages of the biochemical constituents of rat liver mitochondrial membrane (RLM preparation. The extent of lipid hydroperoxide formation, depletion in protein thiols, and formation of protein carbonyls have been biochemically assessed in the presence of varying concentrations of capsaicin in RLM. Decrease in the activities of the important antioxidant enzyme superoxide dismutase, which is involved in the scavenging of free radicals, and the mitochondrial marker enzyme succinate dehydrogenase have been also looked into. Capsaicin has been found to efficiently inhibit radiation-induced biochemical alterations, namely lipid peroxidation and protein oxidation. It also significantly prevented radiation-induced loss in the activity of antioxidant enzyme and the important endogenous antioxidant glutathione. The study suggests that capsaicin can act as an antioxidant and radioprotector in physiological systems. Keywords: capsaicin, gamma radiation, radioprotection, lipid peroxidation, protein oxidation, enzyme activity

  2. Investigation of potential interferences in the detection of atmospheric ROx radicals by laser-induced fluorescence under dark conditions

    Science.gov (United States)

    Fuchs, Hendrik; Tan, Zhaofeng; Hofzumahaus, Andreas; Broch, Sebastian; Dorn, Hans-Peter; Holland, Frank; Künstler, Christopher; Gomm, Sebastian; Rohrer, Franz; Schrade, Stephanie; Tillmann, Ralf; Wahner, Andreas

    2016-04-01

    Direct detection of highly reactive, atmospheric hydroxyl radicals (OH) is widely accomplished by laser-induced fluorescence (LIF) instruments. The technique is also suitable for the indirect measurement of HO2 and RO2 peroxy radicals by chemical conversion to OH. It requires sampling of ambient air into a low-pressure cell, where OH fluorescence is detected after excitation by 308 nm laser radiation. Although the residence time of air inside the fluorescence cell is typically only on the order of milliseconds, there is potential that additional OH is internally produced, which would artificially increase the measured OH concentration. Here, we present experimental studies investigating potential interferences in the detection of OH and peroxy radicals for the LIF instruments of Forschungszentrum Jülich for nighttime conditions. For laboratory experiments, the inlet of the instrument was over flowed by excess synthetic air containing one or more reactants. In order to distinguish between OH produced by reactions upstream of the inlet and artificial signals produced inside the instrument, a chemical titration for OH was applied. Additional experiments were performed in the simulation chamber SAPHIR where simultaneous measurements by an open-path differential optical absorption spectrometer (DOAS) served as reference for OH to quantify potential artifacts in the LIF instrument. Experiments included the investigation of potential interferences related to the nitrate radical (NO3, N2O5), related to the ozonolysis of alkenes (ethene, propene, 1-butene, 2,3-dimethyl-2-butene, α-pinene, limonene, isoprene), and the laser photolysis of acetone. Experiments studying the laser photolysis of acetone yield OH signals in the fluorescence cell, which are equivalent to 0.05 × 106 cm-3 OH for a mixing ratio of 5 ppbv acetone. Under most atmospheric conditions, this interference is negligible. No significant interferences were found for atmospheric concentrations of reactants

  3. Direct evidence of iNOS-mediated in vivo free radical production and protein oxidation in acetone-induced ketosis

    Science.gov (United States)

    Stadler, Krisztian; Bonini, Marcelo G.; Dallas, Shannon; Duma, Danielle; Mason, Ronald P.; Kadiiska, Maria B.

    2008-01-01

    Diabetic patients frequently encounter ketosis that is characterized by the breakdown of lipids with the consequent accumulation of ketone bodies. Several studies have demonstrated that reactive species are likely to induce tissue damage in diabetes, but the role of the ketone bodies in the process has not been fully investigated. In this study, electron paramagnetic resonance (EPR) spectroscopy combined with novel spin-trapping and immunological techniques has been used to investigate in vivo free radical formation in a murine model of acetone-induced ketosis. A six-line EPR spectrum consistent with the α-(4-pyridyl-1-oxide)-N-t-butylnitrone radical adduct of a carbon-centered lipid-derived radical was detected in the liver extracts. To investigate the possible enzymatic source of these radicals, inducible nitric oxide synthase (iNOS) and NADPH oxidase knockout mice were used. Free radical production was unchanged in the NADPH oxidase knockout but much decreased in the iNOS knockout mice, suggesting a role for iNOS in free radical production. Longer-term exposure to acetone revealed iNOS overexpression in the liver together with protein radical formation, which was detected by confocal microscopy and a novel immunospin-trapping method. Immunohistochemical analysis revealed enhanced lipid peroxidation and protein oxidation as a consequence of persistent free radical generation after 21 days of acetone treatment in control and NADPH oxidase knockout but not in iNOS knockout mice. Taken together, our data demonstrate that acetone administration, a model of ketosis, can lead to protein oxidation and lipid peroxidation through a free radical-dependent mechanism driven mainly by iNOS overexpression. PMID:18559982

  4. UVA-induced reset of hydroxyl radical ultradian rhythm improves temporal lipid production in Chlorella vulgaris.

    Science.gov (United States)

    Balan, Ranjini; Suraishkumar, G K

    2014-01-01

    We report for the first time that the endogenous, pseudo-steady-state, specific intracellular levels of the hydroxyl radical (si-OH) oscillate in an ultradian fashion (model system: the microalga, Chlorella vulgaris), and also characterize the various rhythm parameters. The ultradian rhythm in the endogenous levels of the si-OH occurred with an approximately 6 h period in the daily cycle of light and darkness. Further, we expected that the rhythm reset to a shorter period could rapidly switch the cellular redox states that could favor lipid accumulation. We reset the endogenous rhythm through entrainment with UVA radiation, and generated two new ultradian rhythms with periods of approximately 2.97 h and 3.8 h in the light phase and dark phase, respectively. The reset increased the window of maximum lipid accumulation from 6 h to 12 h concomitant with the onset of the ultradian rhythms. Further, the saturated fatty acid content increased approximately to 80% of total lipid content, corresponding to the peak maxima of the hydroxyl radical levels in the reset rhythm. © 2014 American Institute of Chemical Engineers.

  5. 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.

  6. Radiation-induced synthesis of poly(acrylic acid) nanogels

    Science.gov (United States)

    Matusiak, Malgorzata; Kadlubowski, Slawomir; Ulanski, Piotr

    2018-01-01

    Nanogel is a two-component system of a diameter in the range of tens of nanometers, consisting of an intramolecularly crosslinked polymer chain and solvent, typically water, filling the space between segments of the macromolecule. Microgels are bigger than nanogels and their size range is between 100 nm to 100 μm. One of the methods used for synthesizing nanogels is linking the segments of a single macromolecule with the use of ionizing radiation, by intramolecular recombination of radiation-generated polymer radicals. The main advantage of this technique is absence of monomers, catalysts, surfactants or crosslinking agents. This method is an interesting alternative way of synthesizing polymeric carriers for biomedical applications. The aim of the study was radiation synthesis and characterization of poly(acrylic acid) - PAA - nanogels and microgels. The physico-chemical properties were described by determination of weight-average molecular weight and dimensions (radius of gyration, hydrodynamic radius) of the nanogels and microgels. Influence of polymer concentration and dose on these parameters was analyzed. Adjusting the PAA concentration and absorbed dose, one can control the molecular weight and dimensions of nanogels. The solutions of PAA were irradiated with two sources of ionizing radiation: γ-source and electron accelerator. The former method yields mainly microgels due to prevailing intermolecular crosslinking, while the latter promotes intramolecular recombination of PAA-derived radicals and in consequence formation of nanogels. In the future radiation-synthesized PAA nanogels, after functionalization, will be tested as carriers for delivering radionuclides to the tumor cells.

  7. Sub-lethal antibiotic treatment leads to multidrug resistance via radical-induced mutagenesis

    Science.gov (United States)

    Kohanski, Michael A.; DePristo, Mark A.; Collins, James J.

    2010-01-01

    Summary Antibiotic resistance arises through mechanisms such as selection of naturally occurring resistant mutants and horizontal gene transfer. Recently, oxidative stress has been implicated as one of the mechanisms whereby bactericidal antibiotics kill bacteria. Here we show that sub-lethal levels of bactericidal antibiotics induce mutagenesis, resulting in heterogeneous increases in the minimum inhibitory concentration for a range of antibiotics, irrespective of the drug target. This increase in mutagenesis correlates with an increase in ROS, and is prevented by the ROS scavenger thiourea and by anaerobic conditions, indicating that sub-lethal concentrations of antibiotics induce mutagenesis by stimulating the production of ROS. We demonstrate that these effects can lead to mutant strains that are sensitive to the applied antibiotic but resistant to other antibiotics. This work establishes a radical-based molecular mechanism whereby sub-lethal levels of antibiotics can lead to multidrug resistance, which has important implications for the widespread use and misuse of antibiotics. PMID:20159551

  8. Decrease in radiation-induced biological effects due to prior radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Akihisa; Ohnishi, Ken; Ohnishi, Takeo [Nara Medical Univ., Nara (Japan)

    2002-07-01

    We are constantly exposed to environmental radiation. ICRP recommends annual limitations of radiation exposure of 1 and 50 mSv for the general public and for radiation workers, respectively. Initially, there were doubts about different limitations between the two groups based on radiation sensitivity. Regarding the dose/effect relationship, two discrepant hypotheses are the linear no-threshold theory and non-linear with threshold theory, which form the basis of the current radiation protection programs. The radioadaptive response fully occurs near the range of natural radiation and radiation-related working area. This response is a biological defense mechanism in which low dose and low dose-rate irradiation elicits cellular resistance to the genotoxic effects of subsequent irradiation. However, its molecular mechanism remains largely unknown. This article reviews the trends in research and our recent findings on decreases in radiation-induced biological effects due to prior radiation exposure.

  9. Radiation-Induced Amorphization of Crystalline Ice

    Science.gov (United States)

    Fama, M.; Loeffler, M. J.; Raut, U.; Baragiola, R. A.

    2009-01-01

    We study radiation-induced amorphization of crystalline ice, ana lyzing the resu lts of three decades of experiments with a variety of projectiles, irradiation energy, and ice temperature, finding a similar trend of increasing resistance of amorphization with temperature and inconsistencies in results from different laboratories. We discuss the temperature dependence of amorphization in terms of the 'thermal spike' model. We then discuss the common use of the 1.65 micrometer infrared absorption band of water as a measure of degree of crystallinity, an increasingly common procedure to analyze remote sensing data of astronomical icy bodies. The discussion is based on new, high quality near-infrared refl ectance absorption spectra measured between 1.4 and 2.2 micrometers for amorphous and crystalline ices irradiated with 225 keV protons at 80 K. We found that, after irradiation with 10(exp 15) protons per square centimeter, crystalline ice films thinner than the ion range become fully amorphous, and that the infrared absorption spectra show no significant changes upon further irradiation. The complete amorphization suggests that crystalline ice observed in the outer Solar System, including trans-neptunian objects, may results from heat from internal sources or from the impact of icy meteorites or comets.

  10. Coherent Cherenkov radiation from cosmic-ray-induced air showers.

    Science.gov (United States)

    de Vries, K D; van den Berg, A M; Scholten, O; Werner, K

    2011-08-05

    Very energetic cosmic rays entering the atmosphere of Earth will create a plasma cloud moving with almost the speed of light. The magnetic field of Earth induces an electric current in this cloud which is responsible for the emission of coherent electromagnetic radiation. We propose to search for a new effect: Because of the index of refraction of air, this radiation is collimated in a Cherenkov cone. To express the difference from usual Cherenkov radiation, i.e., the emission from a fast-moving electric charge, we call this magnetically induced Cherenkov radiation. We indicate its signature and possible experimental verification.

  11. 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.

  12. 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.

  13. Nicaraven attenuates radiation-induced injury in hematopoietic stem/progenitor cells in mice.

    Directory of Open Access Journals (Sweden)

    Miho Kawakatsu

    Full Text Available Nicaraven, a chemically synthesized hydroxyl radical-specific scavenger, has been demonstrated to protect against ischemia-reperfusion injury in various organs. We investigated whether nicaraven can attenuate radiation-induced injury in hematopoietic stem/progenitor cells, which is the conmen complication of radiotherapy and one of the major causes of death in sub-acute phase after accidental exposure to high dose radiation. C57BL/6 mice were exposed to 1 Gy γ-ray radiation daily for 5 days in succession (a total of 5 Gy, and given nicaraven or a placebo after each exposure. The mice were sacrificed 2 days after the last radiation treatment, and the protective effects and relevant mechanisms of nicaraven in hematopoietic stem/progenitor cells with radiation-induced damage were investigated by ex vivo examination. We found that post-radiation administration of nicaraven significantly increased the number, improved the colony-forming capacity, and decreased the DNA damage of hematopoietic stem/progenitor cells. The urinary levels of 8-oxo-2'-deoxyguanosine, a marker of DNA oxidation, were significantly lower in mice that were given nicaraven compared with those that received a placebo treatment, although the levels of intracellular and mitochondrial reactive oxygen species in the bone marrow cells did not differ significantly between the two groups. Interestingly, compared with the placebo treatment, the administration of nicaraven significantly decreased the levels of the inflammatory cytokines IL-6 and TNF-α in the plasma of mice. Our data suggest that nicaraven effectively diminished the effects of radiation-induced injury in hematopoietic stem/progenitor cells, which is likely associated with the anti-oxidative and anti-inflammatory properties of this compound.

  14. 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

  15. 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.

  16. 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)

  17. Stress-induced colouration and crosslinking of polymeric materials by mechanochemical formation of triphenylimidazolyl radicals.

    Science.gov (United States)

    Verstraeten, F; Göstl, R; Sijbesma, R P

    2016-06-30

    Under mechanical stress, the hexaarylbiimidazole (HABI) motif can cleave to triphenylimidazolyl radicals when incorporated into a polymer matrix. The mechanically produced coloured radicals can initiate secondary radical reactions yielding polymer networks. Thus, the HABI mechanophore combines optical reporting of bond scission and reinforcement of polymers in a single molecular moiety.

  18. Lippia graveolens photochemopreventive effect against UVB radiation-induced skin carcinogenesis.

    Science.gov (United States)

    García-Bores, A M; Espinosa-González, A M; Reyna-Campos, A; Cruz-Toscano, S; Benítez-Flores, J C; Hernández-Delgado, C T; Flores-Maya, S; Urzúa-Meza, M; Peñalosa-Castro, I; Céspedes-Acuña, C L; Avila-Acevedo, J G

    2017-02-01

    Lippia graveolens HBK (Mexican oregano) is a species that is regularly used as a condiment in Mexican cuisine. In traditional medicine, it is used for the treatment of respiratory and digestive illnesses, headaches, rheumatism and inflammation-related disorders. The main chemical components reported in this species include the following: terpenoids, iridoids and flavonoids. The aim of this study was to determine the potential photochemopreventive effect of the methanolic extract of Lippia graveolens (MELG) against ultraviolet B (UVB)-induced skin cancer in SKH-1 mice. The phenolic content, radical scavenger activity, penetration and genotoxicity of the MELG were also evaluated. The MELG exhibited scavenging activity against 1,1-diphenyl-2-picrylhydrazyl, superoxide and hydroxyl radicals, and it did not exhibit genotoxic activity in the micronucleus test. In addition, the MELG absorbed UVB (280nm) electromagnetic radiation. The main components detected in the plant extract were naringenin and galangin, and pinocembrin was also isolated and identified through spectroscopic analysis. The MELG demonstrated a photoprotective effect against UVB-induced cell death in Escherichia coli. In chronic challenge experiments, the MELG protected against UVB-induced skin cancer in SKH-1 mice. The MELG penetrated the skin of mice. Topical administration of the MELG protected against chronic UVB-induced damage in mouse SKH-1 skin. Our results suggest that the MELG has photochemopreventive activity and may potentially prevent photo-tumorigenesis. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Adjuvant Radiation Therapy Following Radical Prostatectomy for Pathologic T3 or Margin-positive Prostate Cancer: Are the EAU Guidelines Correct?

    NARCIS (Netherlands)

    Kamphuis, Guido M.; Sodha, Hiren S.; de Reijke, Theo M.

    2011-01-01

    Objective: To present a critical review of the published data as to whether adjuvant radiation therapy (RT) is the preferred first line of management for pathologic T3 or margin-positive prostate cancer (PCa) after radical prostatectomy (RP), which has level 1B evidence in the European Association

  20. Free Radical Pathology of the Body in the Long-Term Period under Combined Exposure to Gamma Radiation and Emotional Stress in the Experiment

    Science.gov (United States)

    Ilderbayeva, Gulzhan O.; Suleymeneva, Dametken M.; Ilderbayev, ?ralbek Z.; Argynbekova, Ainur S.; Berekenova, Gulnar A.; Syzdykaeva, Sayrangul M.; Kabdykanov, Symbat K.

    2016-01-01

    We have studied the intensity of free radical and antioxidant processes in organs (liver, spleen, thymus, lymph nodes of the small intestine, and adrenal glands) and cells (lymphocytes) in the long-term period after combined exposure to a sublethal dose of ?-radiation (6 Gy) and emotional stress. Combined exposure was followed by accumulation of…

  1. Radiation-induced biomarkers for the detection and assessment of absorbed radiation doses

    Directory of Open Access Journals (Sweden)

    Sudha Rana

    2010-01-01

    Full Text Available Radiation incident involving living organisms is an uncommon but a very serious situation. The first step in medical management including triage is high-throughput assessment of the radiation dose received. Radiation exposure levels can be assessed from viability of cells, cellular organelles such as chromosome and different intermediate metabolites. Oxidative damages by ionizing radiation result in carcinogenesis, lowering of the immune response and, ultimately, damage to the hematopoietic system, gastrointestinal system and central nervous system. Biodosimetry is based on the measurement of the radiation-induced changes, which can correlate them with the absorbed dose. Radiation biomarkers such as chromosome aberration are most widely used. Serum enzymes such as serum amylase and diamine oxidase are the most promising biodosimeters. The level of gene expression and protein are also good biomarkers of radiation.

  2. Vascular leakage induced by exposure to arsenic via increased production of NO, hydroxyl radical and peroxynitrite.

    Science.gov (United States)

    Chen, Shih-Chieh; Chen, Wei-Chi

    2008-04-01

    Previous studies have shown that in situ exposure to arsenic induced increased vascular leakage. However, the underlying mechanism remains unclear. Reactive nitrogen and oxygen species such as nitric oxide (NO) and hydroxyl radical (OH(-)) are known to affect vascular permeability. Therefore, the goal of our present studies is to investigate the functional impact of the generation of NO or OH(-) on arsenic-induced vascular leakage. Vascular permeability changes were evaluated by means of Evans blue (EB) assay. Rats were anesthetized and intravenously injected with EB. Permeability changes were induced in back skin by intradermal injections of sodium arsenite mixed with NOS inhibitor: N(omega)-Nitro-L-arginine methyl ester (L-NAME) or aminoguanidine (AG) and OH(-) scavenger: 1,3 Dimethyl-2 thiourea (DMTU). Experiments were also performed to determine whether DMTU mixed with L-NAME would further inhibit arsenic-induced vascular leakage as compared with attenuation effects by either DMTU or L-NAME. One hour after administration, EB accumulated in the skin was extracted and quantified. Both L-NAME (0.02, 0.1 and 0.5 micromol/site) and DMTU (0.05, 0.2 and 1.2 micromol/site) inhibited the increase in vascular leakage induced by arsenite. However, only high dose (1 micromol/site) of AG significantly attenuated arsenite-induced vascular leakage. In contrast, neither D-NAME (0.02, 0.1 and 0.5 micromol/site) nor AG (0.04 and 0.2 micromol/site) attenuated increased vascular leakage by arsenic. DMTU mixed with L-NAME caused no further inhibition of arsenic-induced vascular leakage by either DMTU or L-NAME. The techniques of India ink and immunostaining were used to demonstrate both vascular labeling and nitrotyrosine staining in tissue treated with arsenic. L-NAME apparently reduced the density of leaky vessels and the levels of peroxynitrite staining induced by arsenite. These results suggest that NO, OH(-) and peroxynitrite play a role in increased vascular permeability

  3. Hyperbaric oxygen: Primary treatment of radiation-induced hemorrhagic cystitis

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, J.P.; Neville, E.C.

    1989-07-01

    Of 8 patients with symptoms of advanced cystitis due to pelvic radiation treated with hyperbaric oxygen 7 are persistently improved during followup. All 6 patients treated for gross hematuria requiring hospitalization have been free of symptoms for an average of 24 months (range 6 to 43 months). One patient treated for stress incontinence currently is dry despite little change in bladder capacity, implying salutary effect from hyperbaric oxygen on the sphincter mechanism. One patient with radiation-induced prostatitis failed to respond. This experience suggests that hyperbaric oxygen should be considered the primary treatment for patients with symptomatic radiation-induced hemorrhagic cystitis.

  4. Prediction of biochemical recurrence after radical prostatectomy. New tool for selecting candidates for adjuvant radiation therapy.

    Science.gov (United States)

    Herranz-Amo, F; Molina-Escudero, R; Ogaya-Pinies, G; Ramírez-Martín, D; Verdú-Tartajo, F; Hernández-Fernández, C

    2016-03-01

    To design a risk summation to select patients for adjuvant radiation therapy after prostatectomy. A retrospective study was conducted on 629 patients with localised prostate cancer (pN0-pNx) who were treated with prostatectomy and with a prostate-specific antigen (PSA) value 0.4ng/mL. A multivariate Cox regression analysis was performed. A score (0-2) was assigned according to the hazard ratio of the significant variables. The score summation defined the risk summation. A total of 19.7% of the patients were pT3, 24.2% had a Gleason score ≥ 8, and 26.3% had positive surgical margins. The median follow-up was 82 months. Some 26.6% of the patients experienced biochemical recurrence. The identified prognostic variables independent of biochemical recurrence were a Gleason score =7 (4+3) (HR, 2.01; P=.008), a Gleason score ≥ 8 (HR, 3.07; P 50% survival free of biochemical recurrence at 5 and 8 years. In contrast, the patients with a risk summation ≥ 3 had <44% survival free of biochemical recurrence. The patients with a risk summation ≤ 2 did not benefit from adjuvant radiation therapy, while the patients with a risk summation ≥ 3 might benefit from adjuvant radiation therapy. Copyright © 2015 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  5. Radiation-induced defects, energy storage and release in nitrogen solids

    Science.gov (United States)

    Savchenko, E.; Khyzhniy, I.; Uyutnov, S.; Bludov, M.; Barabashov, A.; Gumenchuk, G.; Bondybey, V.

    2017-02-01

    New trends in the study of radiation effects in nitrogen solids with a focus on the defect-induced processes are presented. An electron beam of subthreshold energy was used to generate radiation defects via electronic subsystem. Experimental techniques developed enabled us to detect neutral and charged defects of both signs. Defect production and desorption were monitored using optical and current emission spectroscopy: cathodoluminescence CL, thermally stimulated luminescence TSL and exoelectron emission TSEE along with the detection of postdesorption. Our results show stabilization and accumulation of radiation defects - ionic centres of both signs (N4 +, N3 +, N3 -), trapped electrons and radicals (N, N3). The neutralization reactions: N4 ++e-→N4 *→N2 *(a‘1Σu -)+N2 *(a‘1Σu -) +ΔE 1 →N2 +N2 +2hν+ΔE 2 and N3 ++e-→N*(2D)+N2(1Σg +)+ΔE 3→N(4S)+N2(1Σg +)+h γ+ΔE 3 are shown to be the basis of defect production and anomalous low-temperature post-desorption ALTpD. The part played by pre-existing and radiation-induced defects in energy storage is discussed.

  6. Radiation-induced leiomyosarcoma of the posterior neck region.

    Science.gov (United States)

    Santos Gorjón, Pablo; Gil Melcón, María; Muñoz Herrera, Angel M; Franco Calvo, Fernando

    2013-01-01

    Leiomyosarcomas are mesenchymal malignant tumours that appear in smooth muscle cells. Their most frequent locations are the uterus and gastrointestinal tract. Their occurrence in head and neck is considered exceptional. We present a patient with a posterior neck region leiomyosarcoma who had received radiation for a nasopharyngeal carcinoma 20 years earlier. The incidence ratio of these tumours in radiated patients (therefore considered radiation-induced) ranges from 0,035 to 0,2%. Radiation-induced sarcomas are difficult to diagnose due to the induration and fibrosis in the radiated area and the non-specific symptoms that they present. Their prognosis is very poor. Copyright © 2011 Elsevier España, S.L. All rights reserved.

  7. 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

  8. Electronic structure of light-induced lophyl radical derived from a novel hexaarylbiimidazole with pi-conjugated chromophore.

    Science.gov (United States)

    Kikuchi, Azusa; Iyoda, Tomokazu; Abe, Jiro

    2002-07-21

    A novel photochromic hexaarylbiimidazole with a bithienyl group as an extended pi-conjugation unit was synthesized and the light-induced lophyl radical was found to be stabilized due to the delocalization of an unpaired electron, and to strongly absorb near-infrared light.

  9. Probing cardiac metabolism by hyperpolarized 13C MR using an exclusively endogenous substrate mixture and photo-induced nonpersistent radicals

    DEFF Research Database (Denmark)

    Bastiaansen, Jessica A M; Yoshihara, Hikari A I; Capozzi, Andrea

    2018-01-01

    To probe the cardiac metabolism of carbohydrates and short chain fatty acids simultaneously in vivo following the injection of a hyperpolarized 13 C-labeled substrate mixture prepared using photo-induced nonpersistent radicals. Droplets of mixed [1-13 C]pyruvic and [1-13 C]butyric acids were frozen...

  10. Formation and Stabilization of Environmentally Persistent Free Radicals Induced by the Interaction of Anthracene with Fe(III)-Modified Clays.

    Science.gov (United States)

    Jia, Hanzhong; Nulaji, Gulimire; Gao, Hongwei; Wang, Fu; Zhu, Yunqing; Wang, Chuanyi

    2016-06-21

    Environmentally persistent free radicals (EPFRs) are occasionally detected in Superfund sites but the formation of EPFRs induced by polycyclic aromatic hydrocarbons (PAHs) is not well understood. In the present work, the formation of EPFRs on anthracene-contaminated clay minerals was quantitatively monitored via electron paramagnetic resonance (EPR) spectroscopy, and surface/interface-related environmental influential factors were systematically explored. The obtained results suggest that EPFRs are more readily formed on anthracene-contaminated Fe(III)-montmorillonite than in other tested systems. Depending on the reaction condition, more than one type of organic radicals including anthracene-based radical cations with g-factors of 2.0028-2.0030 and oxygenic carbon-centered radicals featured by g-factors of 2.0032-2.0038 were identified. The formed EPFRs are stabilized by their interaction with interlayer surfaces, and such surface-bound EPFRs exhibit slow decay with 1/e-lifetime of 38.46 days. Transformation pathway and possible mechanism are proposed on the basis of experimental results and quantum mechanical simulations. Overall, the formation of EPFRs involves single-electron-transfer from anthracene to Fe(III) initially, followed by H2O addition on formed aromatic radical cation. Because of their potential exposure in soil and atmosphere, such clay surface-associated EPFRs might induce more serious toxicity than PAHs and exerts significant impacts on human health.

  11. Radiation-Induced Heart Disease: Pathologic Abnormalities and Putative Mechanisms

    Directory of Open Access Journals (Sweden)

    Neil K Taunk

    2015-02-01

    Full Text Available Breast cancer is a common diagnosis in women. Breast radiation has become a critical in managing patients who receive breast conserving surgery, or have certain high-risk features after mastectomy. Most patients have an excellent prognosis, therefore understanding the late effects of radiation to the chest is important. Radiation induced heart disease (RIHD comprises a spectrum of cardiac pathology including myocardial fibrosis and cardiomyopathy, coronary artery disease, valvular disease, pericardial disease, and arrhythmias. Tissue fibrosis is a common mediator in RIHD. Multiple pathways converge with both acute and chronic cellular, molecular, and genetic changes to result in fibrosis. In this article, we review the pathophysiology of cardiac disease related to radiation therapy to the chest. Our understanding of these mechanisms has improved substantially, but much work remains to further refine radiation delivery techniques and develop therapeutics to battle late effects of radiation.

  12. Protective effect of aqueous extract from Spirulina platensis against cell death induced by free radicals

    Science.gov (United States)

    2010-01-01

    Background Spirulina is a commercial alga well known to contain various antioxidants, especially phycocyanin. Apart from being sold as a nutraceutical, Spirulina is incorporated as a functional ingredient in food products and beverages. Most of the previous reports on antioxidant activity of Spirulina were based on chemical rather than cell-based assays. The primary objective of this study was to assess the antioxidant activity of aqueous extract from Spirulina based on its protective effect against cell death induced by free radicals. Methods The antioxidant activity of the cold water extract from food-grade Spirulina platensis was assessed using both chemical and cell-based assays. In the cell-based assay, mouse fibroblast cells (3T3) cells were incubated for 1 h in medium containing aqueous extract of Spirulina or vitamin C (positive control) at 25, 125 and 250 μg/mL before the addition of 50 μM 1,1-diphenyl-2-picrylhydrazyl (DPPH) or 3-ethylbenzothiazoline-6-sulfonic acid (ABTS). The cells were incubated for another 24 h before being assessed for cell death due to apoptosis using the Cell Death Detection ELISA Kit. Spectrophotometric assays based on DPPH and ABTS were also used to assess the antioxidant activity of the extract compared to vitamin C and vitamin E (positive controls). Results Spirulina extract did not cause cytotoxic effect on 3T3 cells within the range of concentrations tested (0 - 250 μg/mL). The extract reduced significantly (p Spirulina has a protective effect against apoptotic cell death due to free radicals. The potential application of incorporating Spirulina into food products and beverages to enhance their antioxidant capacity is worth exploring. PMID:20858231

  13. Protective effect of aqueous extract from Spirulina platensis against cell death induced by free radicals

    Directory of Open Access Journals (Sweden)

    Radhakrishnan Ammu

    2010-09-01

    Full Text Available Abstract Background Spirulina is a commercial alga well known to contain various antioxidants, especially phycocyanin. Apart from being sold as a nutraceutical, Spirulina is incorporated as a functional ingredient in food products and beverages. Most of the previous reports on antioxidant activity of Spirulina were based on chemical rather than cell-based assays. The primary objective of this study was to assess the antioxidant activity of aqueous extract from Spirulina based on its protective effect against cell death induced by free radicals. Methods The antioxidant activity of the cold water extract from food-grade Spirulina platensis was assessed using both chemical and cell-based assays. In the cell-based assay, mouse fibroblast cells (3T3 cells were incubated for 1 h in medium containing aqueous extract of Spirulina or vitamin C (positive control at 25, 125 and 250 μg/mL before the addition of 50 μM 1,1-diphenyl-2-picrylhydrazyl (DPPH or 3-ethylbenzothiazoline-6-sulfonic acid (ABTS. The cells were incubated for another 24 h before being assessed for cell death due to apoptosis using the Cell Death Detection ELISA Kit. Spectrophotometric assays based on DPPH and ABTS were also used to assess the antioxidant activity of the extract compared to vitamin C and vitamin E (positive controls. Results Spirulina extract did not cause cytotoxic effect on 3T3 cells within the range of concentrations tested (0 - 250 μg/mL. The extract reduced significantly (p Conclusions The results showed that aqueous extract of Spirulina has a protective effect against apoptotic cell death due to free radicals. The potential application of incorporating Spirulina into food products and beverages to enhance their antioxidant capacity is worth exploring.

  14. Protective effect of aqueous extract from Spirulina platensis against cell death induced by free radicals.

    Science.gov (United States)

    Chu, Wan-Loy; Lim, Yen-Wei; Radhakrishnan, Ammu Kutty; Lim, Phaik-Eem

    2010-09-21

    Spirulina is a commercial alga well known to contain various antioxidants, especially phycocyanin. Apart from being sold as a nutraceutical, Spirulina is incorporated as a functional ingredient in food products and beverages. Most of the previous reports on antioxidant activity of Spirulina were based on chemical rather than cell-based assays. The primary objective of this study was to assess the antioxidant activity of aqueous extract from Spirulina based on its protective effect against cell death induced by free radicals. The antioxidant activity of the cold water extract from food-grade Spirulina platensis was assessed using both chemical and cell-based assays. In the cell-based assay, mouse fibroblast cells (3T3) cells were incubated for 1 h in medium containing aqueous extract of Spirulina or vitamin C (positive control) at 25, 125 and 250 μg/mL before the addition of 50 μM 1,1-diphenyl-2-picrylhydrazyl (DPPH) or 3-ethylbenzothiazoline-6-sulfonic acid (ABTS). The cells were incubated for another 24 h before being assessed for cell death due to apoptosis using the Cell Death Detection ELISA Kit. Spectrophotometric assays based on DPPH and ABTS were also used to assess the antioxidant activity of the extract compared to vitamin C and vitamin E (positive controls). Spirulina extract did not cause cytotoxic effect on 3T3 cells within the range of concentrations tested (0 - 250 μg/mL). The extract reduced significantly (p Spirulina has a protective effect against apoptotic cell death due to free radicals. The potential application of incorporating Spirulina into food products and beverages to enhance their antioxidant capacity is worth exploring.

  15. Optical imaging of radiation-induced metabolic changes in radiation-sensitive and resistant cancer cells

    Science.gov (United States)

    Alhallak, Kinan; Jenkins, Samir V.; Lee, David E.; Greene, Nicholas P.; Quinn, Kyle P.; Griffin, Robert J.; Dings, Ruud P. M.; Rajaram, Narasimhan

    2017-06-01

    Radiation resistance remains a significant problem for cancer patients, especially due to the time required to definitively determine treatment outcome. For fractionated radiation therapy, nearly 7 to 8 weeks can elapse before a tumor is deemed to be radiation-resistant. We used the optical redox ratio of FAD/(FAD+NADH) to identify early metabolic changes in radiation-resistant lung cancer cells. These radiation-resistant human A549 lung cancer cells were developed by exposing the parental A549 cells to repeated doses of radiation (2 Gy). Although there were no significant differences in the optical redox ratio between the parental and resistant cell lines prior to radiation, there was a significant decrease in the optical redox ratio of the radiation-resistant cells 24 h after a single radiation exposure (p=0.01). This change in the redox ratio was indicative of increased catabolism of glucose in the resistant cells after radiation and was associated with significantly greater protein content of hypoxia-inducible factor 1 (HIF-1α), a key promoter of glycolytic metabolism. Our results demonstrate that the optical redox ratio could provide a rapid method of determining radiation resistance status based on early metabolic changes in cancer cells.

  16. Inactivation of alpha1-antiproteinase induced by phenylbutazone: participation of peroxyl radicals and hydroperoxide.

    Science.gov (United States)

    Muraoka, Sanae; Miura, Toshiaki

    2006-09-01

    To clarify the action of a side-effect of phenylbutazone, we investigated the inactivation of alpha(1)-antiproteinase induced by phenylbutazone in the presence of horseradish peroxidase (HRP) and H(2)O(2) (HRP-H(2)O(2)). The activity of alpha(1)-antiproteinase was rapidly lost during the interaction of phenylbutazone with HRP-H(2)O(2) under aerobic conditions. Phenylbutazone showed a marked spectral change under aerobic conditions but not under anaerobic conditions. Spin trap agents were very effective in inhibiting alpha(1)-antiproteinase inactivation induced by phenylbutazone. Oxidation of phenylbutazone was stopped by catalase, but the inactivation reaction of alpha(1)-antiproteinase proceeded even after removal of H(2)O(2) in the reaction mixture. Formation of the peroxidative product from phenylbutazone was detected by iodometric assay. These results indicate that both peroxyl radicals and the peroxidative product of phenylbutazone participated in the inactivation of alpha(1)-antiproteinase. Other anti-inflammatory drugs did not inactivate alpha(1)-antiproteinase during interaction with HRP-H(2)O(2). Inactivation of alpha(1)-antiproteinase may contribute to serious side effects of phenylbutazone.

  17. Prophylactic role of melatonin against radiation induced damage in mouse cerebellum with special reference to Purkinje cells

    Energy Technology Data Exchange (ETDEWEB)

    Sisodia, Rashmi; Kumari, Seema; Verma, Rajesh Kumar; Bhatia, A L [Neurobiology Laboratory, Department of Zoology, University of Rajasthan, Jaipur 302004 (India)

    2006-06-15

    Melatonin, a hormone with a proven antioxidative efficacy, crosses all morphophysiological barriers, including the blood-brain barrier, and distributes throughout the cell. The present study is an attempt to investigate the prophylactic influence of a chronic low level of melatonin against an acute radiation induced oxidative stress in the cerebellum of Swiss albino mice, with special reference to Purkinje cells. After 15 days of treatment the mice were sacrificed at various intervals from 1 to 30 days. Biochemical parameters included lipid peroxidation (LPO) and glutathione (GSH) levels as the endpoints. The quantitative study included alterations in number and volume of Purkinje cells. Swiss albino mice were orally administered a very low dose of melatonin (0.25 mg/mouse/day) for 15 consecutive days before single exposure to 4 Gy gamma radiation. Melatonin checked the augmented levels of LPO, by approximately 55%, by day 30 day post-exposure. Radiation induced depleted levels of GSH could be raised by 68.9% by day 30 post-exposure. Radiation exposure resulted in a reduction of the volume of Purkinje cells and their total number. The administration of melatonin significantly protected against the radiation induced decreases in Purkinje cell volume and number. Results indicate the antioxidative properties of melatonin resulting in its prophylactic property against radiation induced biochemical and cellular alterations in the cerebellum. The findings support the idea that melatonin may be used as an anti-irradiation drug due to its potent free radical scavenging and antioxidative efficacy.

  18. Radiation recall dermatitis induced by trastuzumab

    Directory of Open Access Journals (Sweden)

    Emre Kaynak

    2014-12-01

    Full Text Available Radiation recall phenomenon is an acute, egzematous reaction that develops throughout a previously irradiated area, precipitated by the administration of docetaxel, doxorubicin, gemcitabine and paclitaxel. We report a 52-year-old woman with breast cancer who received locoregional radiotherapy followed by trastuzumab monotherapy. Three day after the first cycle of trastuzumab monotherapy, dermatitis developed in the previously irradiated skin.

  19. RADIATION INDUCED VULCANIZATION OF RUBBER LATEX

    Science.gov (United States)

    Mesrobian, R.B.; Ballantine, D.S.; Metz, D.J.

    1964-04-28

    A method of vulcanizing rubber latex by exposing a mixture containing rubber latex and from about 15 to about 21.3 wt% of 2,5-dichlorostyrene to about 1.1 megarads of gamma radiation while maintaining the temperature of the mixture at a temperature ranging between from about 56 to about 59 deg C is described. (AEC)

  20. Prevention Of Radiation Induced Hematological Alterations By ...

    African Journals Online (AJOL)

    The modulatory influence of Rosmarinus officinalis (rosemary) leaves extract was investigated in Swiss albino mice at a dose of 3 Gy gamma radiation. For this purpose, adult Swiss albino mice were irradiated with 3 Gy gamma rays in the presence (experimental) or absence (control) of rosemary (1000 mg/kg body wt.).

  1. Revisiting scaling properties of medium-induced gluon radiation

    CERN Document Server

    Arleo, Francois; Sami, Taklit

    2011-01-01

    Discussing the general case of a hard partonic production process, we show that the notion of parton energy loss is not always sufficient to fully address medium-induced gluon radiation. The broader notion of gluon radiation associated to a hard process has to be used, in particular when initial and final state radiation amplitudes interfere, making the medium-induced radiated energy different from the energy loss of any well-identified parton. Our arguments are first presented in an abelian QED model, and then applied to large-xF quarkonium hadroproduction. In this case, we show that the medium-induced radiated energy is qualitatively similar (but not identical) to the radiative energy loss of an "asymptotic massive parton" undergoing transverse momentum broadening when travelling through the nucleus. In particular, it scales as the incoming parton energy, which suggests to reconsider gluon radiation as a possible explanation of large-xF quarkonium suppression in p-A collisions. We expect a similar effect in...

  2. Adjuvant radiation therapy is associated with better oncological outcome compared with salvage radiation therapy in patients with pN1 prostate cancer treated with radical prostatectomy.

    Science.gov (United States)

    Tilki, Derya; Preisser, Felix; Tennstedt, Pierre; Tober, Patrick; Mandel, Philipp; Schlomm, Thorsten; Steuber, Thomas; Huland, Hartwig; Schwarz, Rudolf; Petersen, Cordula; Graefen, Markus; Ahyai, Sascha

    2017-05-01

    To analyse the comparative effectiveness of no treatment (NT) or salvage radiation therapy (sRT) at biochemical recurrence (BCR) vs adjuvant radiation therapy (aRT) in patients with lymph node (LN)-positive prostate cancer (PCa) after radical prostatectomy (RP). A total of 773 patients with LN-positive PCa at RP, with or without additional radiation therapy (RT), in the period 2005-2013, were retrospectively analysed. Cox regression analysis was used to assess factors influencing BCR and metastasis-free survival (MFS). Propensity score-matched analyses were performed. The median follow-up for the entire patient group was 33.8 months. Four-year BCR-free and MFS rates were 43.3% and 86.6%, respectively, for all patients. In multivariate analysis, NT/sRT (n = 505) was an independent risk factor for BCR and metastasis compared with aRT (n = 213). The superiority of aRT was confirmed after propensity score matching. The 4-year MFS in the matched cohort was 82.5% vs 91.8% for the NT/sRT and aRT groups, respectively (P = 0.02). Early sRT (pre-RT prostate-specific antigen [PSA] ≤0.5 ng/mL) compared with sRT at PSA >0.5 ng/mL was significantly associated with a lower risk of metastasis. Patients with LN-positive PCa who received aRT had a significantly better oncological outcome than patients with NT/sRT, independent of tumour characteristics. Patients with early sRT had higher rates of response and better MFS than patients with pre-RT PSA >0.5 ng/mL. © 2016 The Authors BJU International © 2016 BJU International Published by John Wiley & Sons Ltd.

  3. Dietary Supplement Attenuates Radiation-Induced Osteoclastogenic and Oxidative Stress-Related Responses and Protects Adult Mice from Radiation-Induced Bone Loss

    Science.gov (United States)

    Globus, Ruth; Schreurs, Ann-Sofie; Tahimic, Candice; Shirazi-Fard, Yasaman; Alwood, Joshua; Shahnazari, Mohammed; Halloran, Bernard

    2015-01-01

    Our central hypothesis is that oxidative stress plays a key role in cell dysfunction and progressive bone loss caused by radiation exposure during spaceflight. In animal studies, excess free radical formation is associated with pathological changes in bone structure, enhanced bone resorption, reduced bone formation and decreased bone mineral density, which can lead to skeletal fragility. We previously reported that exposure to low or high-LET radiation rapidly increases expression levels of pro-osteoclastogenic and oxidative stress-related genes in bone and marrow, followed by pathological changes in skeletal structure. To screen various antioxidants for radioprotective effects on bone, 4 month old, male C57Bl6/J mice were treated with a dietary antioxidant cocktail, injectable alpha-lipoic acid, or a dried plum-enriched diet (DP). Mice were then exposed to 2Gy 137Cs total body radiation and one day later marrow cells were collected and the relevant genes analyzed for expression levels. Of the candidates tested, DP was most effective in reducing bone resorption-related gene expression. Microcomputed tomography revealed that DP also prevented the radiation-induced deterioration of skeletal microarchitecture, as indicated by percent bone volume, trabecular spacing and trabecular number. DP had similar protective effects on skeletal structure after sequential exposure to protons (0.5 Gy, 150MeV/n) and 56Fe 0.5Gy, 600 MeV/n). When cultured ex vivo under osteogenic conditions, bone marrow-derived cells from DP-fed animals exhibited increased colony numbers compared to control diet-fed animals. These findings suggest that DP exerted pro-osteogenic effects apart from previously identified anti-resorptive actions, which may contribute to radioprotection of skeletal tissue. In conclusion, a diet enriched in certain types of antioxidants and polyphenols such as DP may be useful as an intervention to protect tissues from degenerative effects of ionizing radiation.

  4. Applications of EPR in radiation research

    CERN Document Server

    Lund, Anders

    2014-01-01

    Applications of EPR in Radiation Research is a multi-author contributed volume presented in eight themes: I. Elementary radiation processes (in situ and low temperature radiolysis, quantum solids); II: Solid state radiation chemistry (crystalline, amorphous and heterogeneous systems); III: Biochemistry, biophysics and biology applications (radicals in biomaterials, spin trapping, free-radical-induced DNA damage); IV: Materials science (polymeric and electronic materials, materials for treatment of nuclear waste, irradiated food); V: Radiation metrology (EPR-dosimetry, retrospective and medical

  5. Novel Radiomitigator for Radiation-Induced Bone Loss

    Science.gov (United States)

    Schreurs, A-S; Shirazi-fard, Y.; Terada, M.; Alwood, J. S.; Steczina, S.; Medina, C.; Tahimic, C. G. T.; Globus, R. K.

    2016-01-01

    Radiation-induced bone loss can occur with radiotherapy patients, accidental radiation exposure and during long-term spaceflight. Bone loss due to radiation is due to an early increase in oxidative stress, inflammation and bone resorption, resulting in an imbalance in bone remodeling. Furthermore, exposure to high-Linear Energy Transfer (LET) radiation will impair the bone forming progenitors and reduce bone formation. Radiation can be classified as high-LET or low-LET based on the amount of energy released. Dried Plum (DP) diet prevents bone loss in mice exposed to total body irradiation with both low-LET and high-LET radiation. DP prevents the early radiation-induced bone resorption, but furthermore, we show that DP protects the bone forming osteoblast progenitors from high-LET radiation. These results provide insight that DP re-balances the bone remodeling by preventing resorption and protecting the bone formation capacity. This data is important considering that most of the current osteoporosis treatments only block the bone resorption but do not protect bone formation. In addition, DP seems to act on both the oxidative stress and inflammation pathways. Finally, we have preliminary data showing the potential of DP to be radio-protective at a systemic effect and could possible protect other tissues at risk of total body-irradiation such as skin, brain and heart.

  6. Superoxide radicals can act synergistically with hypochlorite to induce damage to proteins

    DEFF Research Database (Denmark)

    Hawkins, Clare Louise; Rees, Martin D; Davies, Michael Jonathan

    2002-01-01

    Activated phagocytes generate both superoxide radicals via a respiratory burst, and HOCl via the concurrent release of the haem enzyme myeloperoxidase. Amine and amide functions on proteins and carbohydrates are major targets for HOCl, generating chloramines (RNHCl) and chloramides (RC(O)NClR'), ......Activated phagocytes generate both superoxide radicals via a respiratory burst, and HOCl via the concurrent release of the haem enzyme myeloperoxidase. Amine and amide functions on proteins and carbohydrates are major targets for HOCl, generating chloramines (RNHCl) and chloramides (RC......(O)NClR'), which can accumulate to high concentrations (>100 microM). Here we show that superoxide radicals catalyse the decomposition of chloramines and chloramides to reactive nitrogen-centred radicals, and increase the extent of protein fragmentation compared to that observed with either superoxide radicals...... or HOCl, alone. This synergistic action may be of significance at sites of inflammation, where both superoxide radicals and chloramines/chloramides are formed simultaneously....

  7. Radiation-induced defects in magnesium lactate as ESR dosimeter

    CERN Document Server

    Hassan, G M; Takaki, S

    1999-01-01

    Magnesium lactate (Mg-lactate: (CH sub 3 CH(OH)COO) sub 2 Mg), magnesium lactate doped with lithium lactate (Mg(Li)-lactate) and nominal pure lithium lactate (CH sub 3 CH(OH)COOLi) doped with Mg-lactate (Li(Mg)-lactate) were irradiated by gamma-rays to study radicals for materials of radiation dosimeter with electron spin resonance (ESR). Quartet spectra were ascribed to lactate radicals in Mg-lactate and Li(Mg)-lactate with the spectroscopic splitting factors (g-factor) of 2.0032+-0.004 and 2.0029+-0.004 and the intensity ratio of 1:3:3:1 due to the hyperfine coupling constants of (A/g beta) of 1.92+-0.06 and 1.82+-0.06 mT, respectively. The response to gamma-ray dose and the thermal stability as well as the effect of UV-illumination have been studied to establish this material as an ESR dosimeter. The number of free radicals per 100 eV (G-value) was obtained to be 1.15+-0.32, 1.35+-0.35, 0.46+-0.14 and 0.78+-0.24 for Mg-lactate, Mg(Li)-lactate, Li-lactate and Lie(Mg)-lactate, respectively. Thermoluminescenc...

  8. Cytoprotective Mechanisms Mediated by Polyphenols from Chilean Native Berries against Free Radical-Induced Damage on AGS Cells

    Science.gov (United States)

    Theoduloz, Cristina; López-Alarcón, Camilo; Dorta, Eva

    2017-01-01

    The prevalence of cytoprotective mechanisms induced by polyphenols such as activation of intracellular antioxidant responses (ICM) and direct free radical scavenging was investigated in native Chilean species of strawberries, raspberries, and currants. Human gastric epithelial cells were co- and preincubated with polyphenolic-enriched extracts (PEEs) from Chilean raspberries (Rubus geoides), strawberries (Fragaria chiloensis ssp. chiloensis f. chiloensis), and currants (Ribes magellanicum) and challenged with peroxyl and hydroxyl radicals. Cellular protection was determined in terms of cell viability, glyoxalase I and glutathione s-transferases activities, and carboxymethyl lysine (CML) and malondialdehyde levels. Our results indicate that cytoprotection induced by ICM was the prevalent mechanism for Rubus geoides and F. chiloensis. This agreed with increased levels of glyoxalase I and glutathione S-transferase activities in cells preincubated with PEEs. ORAC index indicated that F. chiloensis was the most efficient peroxyl radical scavenger. Moreover, ICM mediated by F. chiloensis was effective in protecting cells from CML accumulation in contrast to the protective effects induced by free radical scavenging. Our results indicate that although both polyphenol-mediated mechanisms can exert protective effects, ICM was the most prevalent in AGS cells. These results suggest a potential use of these native berries as functional food. PMID:28553436

  9. Cytoprotective Mechanisms Mediated by Polyphenols from Chilean Native Berries against Free Radical-Induced Damage on AGS Cells

    Directory of Open Access Journals (Sweden)

    Felipe Ávila

    2017-01-01

    Full Text Available The prevalence of cytoprotective mechanisms induced by polyphenols such as activation of intracellular antioxidant responses (ICM and direct free radical scavenging was investigated in native Chilean species of strawberries, raspberries, and currants. Human gastric epithelial cells were co- and preincubated with polyphenolic-enriched extracts (PEEs from Chilean raspberries (Rubus geoides, strawberries (Fragaria chiloensis ssp. chiloensis f. chiloensis, and currants (Ribes magellanicum and challenged with peroxyl and hydroxyl radicals. Cellular protection was determined in terms of cell viability, glyoxalase I and glutathione s-transferases activities, and carboxymethyl lysine (CML and malondialdehyde levels. Our results indicate that cytoprotection induced by ICM was the prevalent mechanism for Rubus geoides and F. chiloensis. This agreed with increased levels of glyoxalase I and glutathione S-transferase activities in cells preincubated with PEEs. ORAC index indicated that F. chiloensis was the most efficient peroxyl radical scavenger. Moreover, ICM mediated by F. chiloensis was effective in protecting cells from CML accumulation in contrast to the protective effects induced by free radical scavenging. Our results indicate that although both polyphenol-mediated mechanisms can exert protective effects, ICM was the most prevalent in AGS cells. These results suggest a potential use of these native berries as functional food.

  10. Protein oxidative modifications during electrospray ionization: solution phase electrochemistry or corona discharge-induced radical attack?

    Science.gov (United States)

    Boys, Brian L; Kuprowski, Mark C; Noël, James J; Konermann, Lars

    2009-05-15

    The exposure of solution-phase proteins to reactive oxygen species (ROS) causes oxidative modifications, giving rise to the formation of covalent +16 Da adducts. Electrospray ionization (ESI) mass spectrometry (MS) is the most widely used method for monitoring the extent of these modifications. Unfortunately, protein oxidation can also take place as an experimental artifact during ESI, such that it may be difficult to assess the actual level of oxidation in bulk solution. Previous work has demonstrated that ESI-induced oxidation is highly prevalent when operating at strongly elevated capillary voltage V(0) (e.g., +8 kV) and with oxygen nebulizer gas in the presence of a clearly visible corona discharge. Protein oxidation under these conditions is commonly attributed to OH radicals generated in the plasma of the discharge. On the other hand, charge balancing oxidation reactions are known to take place at the metal/liquid interface of the emitter. Previous studies have not systematically explored whether such electrochemical processes could be responsible for the formation of oxidative +16 Da adducts instead of (or in combination with) plasma-generated ROS. Using hemoglobin as a model system, this work illustrates the occurrence of extensive protein oxidation even under typical operating conditions (e.g., V(0) = 3.5 kV, N(2) nebulizer gas). Surprisingly, measurements of the current flowing in the ESI circuit demonstrate that a weak corona discharge persists for these relatively gentle settings. On the basis of comparative experiments with nebulizer gases of different dielectric strength, it is concluded that ROS generated under discharge conditions are solely responsible for ESI-induced protein oxidation. This result is corroborated through off-line electrolysis experiments designed to mimic the electrochemical processes taking place during ESI. Our findings highlight the necessity of using easily oxidizable internal standards in biophysical or biomedical ESI

  11. Oxygen radicals induce human endothelial cells to express GMP-140 and bind neutrophils.

    Science.gov (United States)

    Patel, K D; Zimmerman, G A; Prescott, S M; McEver, R P; McIntyre, T M

    1991-02-01

    The initial step in extravasation of neutrophils (polymorphonuclear leukocytes [PMNs]) to the extravascular space is adherence to the endothelium. We examined the effect of oxidants on this process by treating human endothelial cells with H2O2, t-butylhydroperoxide, or menadione. This resulted in a surface adhesive for PMN between 1 and 4 h after exposure. The oxidants needed to be present only for a brief period at the initiation of the assay. Adhesion was an endothelial cell-dependent process that did not require an active response from the PMN. The adhesive molecule was not platelet-activating factor, which mediates PMN adherence when endothelial cells are briefly exposed to higher concentrations of H2O2 (Lewis, M. S., R. E. Whatley, P. Cain, T. M. McIntyre, S. M. Prescott, and G. A. Zimmerman. 1988. J. Clin. Invest. 82:2045-2055), nor was it ELAM-1, an adhesive glycoprotein induced by cytokines. Oxidant-induced adhesion did not require protein synthesis, was inhibited by antioxidants, and, when peroxides were the oxidants, was inhibited by intracellular iron chelators. Granule membrane protein-140 (GMP-140) is a membrane-associated glycoprotein that can be translocated from its intracellular storage pool to the surface of endothelial cells where it acts as a ligand for PMN adhesion (Geng, J.-G., M. P. Bevilacqua, K. L. Moore, T. M. McIntyre, S. M. Prescott, J. M. Kim, G. A. Bliss, G. A. Zimmerman, and R. P. McEver. 1990. Nature (Lond). 343:757-760). We found that endothelial cells exposed to oxidants expressed GMP-140 on their surface, and that an mAb against GMP-140 or solubilized GMP-140 completely blocked PMN adherence to oxidant-treated endothelial cells. Thus, exposure of endothelial cells to oxygen radicals induces the prolonged expression of GMP-140 on the cell surface, which results in enhanced PMN adherence.

  12. 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

  13. Radiation recall dermatitis induced by trastuzumab.

    Science.gov (United States)

    Moon, Dochang; Koo, Ja Seung; Suh, Chang-Ok; Yoon, Chang Yun; Bae, Jaehyun; Lee, Soohyeon

    2016-01-01

    We report a case of radiation recall dermatitis caused by trastuzumab. A 55-year-old woman with metastatic breast cancer received palliative first-line trastuzumab/paclitaxel and a salvage partial mastectomy with lymph node dissection was subsequently performed. In spite of the palliative setting, the pathology report indicated that no residual carcinoma was present, and then she underwent locoregional radiotherapy to ensure a definitive response. After radiotherapy, she has maintained trastuzumab monotherapy. Nine days after the fifth cycle of trastuzumab monotherapy, dermatitis in previously irradiated skin developed, with fever. Radiation recall dermatitis triggered by trastuzumab is extremely rare. A high fever developed abruptly with a skin rash. This may be the first case of this sort to be reported.

  14. Radiation-induced malignant fibrous histiocytoma of the maxilla.

    Science.gov (United States)

    Satomi, Takafumi; Watanabe, Masato; Kaneko, Tadayoshi; Matsubayashi, Jun; Nagao, Toshitaka; Chiba, Hiroshige

    2011-07-01

    Malignant fibrous histiocytoma (MFH) originates from primitive mesenchymal cells and has the capacity for dual histiocytic and fibroblastic differentiation. We report on an MFH of the left maxilla that developed in a 79-year old woman 20 years after surgery and radiation for squamous cell carcinoma (SCC). Postoperative radiotherapy with 70 Gy was administered for a primary neoplasm of SCC of the left maxilla to a localized field through two lateral ports. This secondary neoplasm arose at the site of tumor resection (partial maxillectomy) within the irradiated field, and was resected. The development of sarcomas is a recognized complication of radiation therapy. The final diagnosis after the operation was MFH. The patient died of tumor recurrence at the skull base and within the cranium, 19 months after the operation. Radiation-induced sarcoma is well known, but radiation-induced MFH is relatively rare in the head and neck region. The details of this case are presented with a review of literature.

  15. Radiosensitivities of parabens and characterization of the radical species induced in this class of antimicrobial agents after gamma irradiation

    Science.gov (United States)

    Üstündaǧ, Ilknur; Korkmaz, Özden

    Radiosensitivities of methyl, ethyl, propyl and butyl parabens and sodium salts of methyl and propyl parabens (hereafter, MP, EP, PP, BP, SMP and SPP, respectively) were investigated by monitoring, through electron spin resonance (ESR) spectroscopy, the evolution under different experimental conditions of characteristic features of the radicalic species produced upon irradiation by gamma radiation. While ESR spectra of the studied parabens consisted of the sum of broad and narrow resonance lines of different microwave saturation and thermal characteristics, those of sodium salts appeared to consist of the sum of two overlapping narrow resonance lines. Radical species presented different room and high-temperature decay characteristics, depending on the extent of the cage effect created by the lattice networks on these species. A model based on the presence of two radical species presenting different spectroscopic and kinetic features described best the experimental data collected for parabens and their sodium salts. Radiation yields of the studied parabens towards gamma radiation were calculated to be low (G≤10-2), providing the opportunity of using these antimicrobial agents in food, cosmetics and drugs to be sterilized by radiation without much loss from their antimicrobial activities.

  16. Radiation-induced edge effects in deep submicron CMOS transistors

    CERN Document Server

    Faccio, F

    2005-01-01

    The study of the TID response of transistors and isolation test structures in a 130 nm commercial CMOS technology has demonstrated its increased radiation tolerance with respect to older technology nodes. While the thin gate oxide of the transistors is extremely tolerant to dose, charge trapping at the edge of the transistor still leads to leakage currents and, for the narrow channel transistors, to significant threshold voltage shift-an effect that we call Radiation Induced Narrow Channel Effect (RINCE).

  17. Radiation-induced apoptosis in microvascular endothelial cells.

    OpenAIRE

    Langley, R. E.; Bump, E A; Quartuccio, S. G.; Medeiros, D; Braunhut, S. J.

    1997-01-01

    The response of the microvasculature to ionizing radiation is thought to be an important factor in the overall response of both normal tissues and tumours. It has recently been reported that basic fibroblast growth factor (bFGF), a potent mitogen for endothelial cells, protects large vessel endothelial cells from radiation-induced apoptosis in vitro. Microvessel cells are phenotypically distinct from large vessel cells. We studied the apoptotic response of confluent monolayers of capillary en...

  18. Intravesical ozone therapy for progressive radiation-induced hematuria.

    Science.gov (United States)

    Clavo, Bernardino; Gutiérrez, Dominga; Martín, Dionisio; Suárez, Gerardo; Hernández, María A; Robaina, Francisco

    2005-06-01

    Progressive radiation-induced cystitis can become a serious clinical problem the therapeutic solution of which is limited and almost invariably aggressive. Ozone therapy is a nonconventional therapy that has been reported to offer benefits in late-onset wound healing and ischemic disorders. This report describes a patient with progressive radiation-induced hematuria from standard conservative treatment that was further treated with ozone therapy. Ozone therapy was achieved by intravesical instillation of ozonized bi-distilled water over a period of 30 minutes, three sessions per week during the first weeks. Later, ozone therapy sessions were decreased and involved ozonized water or direct intravesicular instillation of ozone at 20-25 microg/mL. Hematuria was successfully controlled by intravesical application of ozone therapy. The successes achieved with this technique suggest that intravesicular instillation of ozonized bi-distilled water or ozone merits further investigation with a view to its application to counter this radiation-induced side-effect.

  19. Blue light induces mitochondrial DNA damage and free radical production in epithelial cells.

    Science.gov (United States)

    Godley, Bernard F; Shamsi, Farrukh A; Liang, Fong-Qi; Jarrett, Stuart G; Davies, Sallyanne; Boulton, Mike

    2005-06-03

    Exposure of biological chromophores to ultraviolet radiation can lead to photochemical damage. However, the role of visible light, particularly in the blue region of the spectrum, has been largely ignored. To test the hypothesis that blue light is toxic to non-pigmented epithelial cells, confluent cultures of human primary retinal epithelial cells were exposed to visible light (390-550 nm at 2.8 milliwatts/cm2) for up to 6 h. A small loss of mitochondrial respiratory activity was observed at 6 h compared with dark-maintained cells, and this loss became greater with increasing time. To investigate the mechanism of cell loss, the damage to mitochondrial and nuclear genes was assessed using the quantitative PCR. Light exposure significantly damaged mitochondrial DNA at 3 h (0.7 lesion/10 kb DNA) compared with dark-maintained controls. However, by 6 h of light exposure, the number of lesions was decreased in the surviving cells, indicating DNA repair. Isolated mitochondria exposed to light generated singlet oxygen, superoxide anion, and the hydroxyl radical. Antioxidants confirmed the superoxide anion to be the primary species responsible for the mitochondrial DNA lesions. The effect of lipofuscin, a photoinducible intracellular generator of reactive oxygen intermediates, was investigated for comparison. Exposure of lipofuscin-containing cells to visible light caused an increase in both mitochondrial and nuclear DNA lesions compared with non-pigmented cells. We conclude that visible light can cause cell dysfunction through the action of reactive oxygen species on DNA and that this may contribute to cellular aging, age-related pathologies, and tumorigenesis.

  20. 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.

  1. Chronic radiation-induced dermatitis: challenges and solutions

    Directory of Open Access Journals (Sweden)

    Spałek M

    2016-12-01

    Full Text Available Mateusz Spałek Department of Radiotherapy I, The Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw, Poland Abstract: Chronic radiation dermatitis is a late side effect of skin irradiation, which may deteriorate patients’ quality of life. There is a lack of precise data about its incidence; however, several risk factors may predispose to the development of this condition. It includes radiotherapy dose, fractionation, technique, concurrent systemic therapy, comorbidities, and personal and genetic factors. Chronic radiation dermatitis is mostly caused by the imbalance of proinflammatory and profibrotic cytokines. Clinical manifestation includes changes in skin appearance, wounds, ulcerations, necrosis, fibrosis, and secondary cancers. The most severe complication of irradiation is extensive radiation-induced fibrosis (RIF. RIF can manifest in many ways, such as skin induration and retraction, lymphedema or restriction of joint motion. Diagnosis of chronic radiation dermatitis is usually made by clinical examination. In case of unclear clinical manifestation, a biopsy and histopathological examination are recommended to exclude secondary malignancy. The most effective prophylaxis of chronic radiation dermatitis is the use of proper radiation therapy techniques to avoid unnecessary irradiation of healthy skin. Treatment of chronic radiation dermatitis is demanding. The majority of the interventions are based only on clinical practice. Telangiectasia may be treated with pulse dye laser therapy. Chronic postirradiation wounds need special dressings. In case of necrosis or severe ulceration, surgical intervention may be considered. Management of RIF should be complex. Available methods are rehabilitative care, pharmacotherapy, hyperbaric oxygen therapy, and laser therapy. Future challenges include the assessment of late skin toxicity in modern irradiation techniques. Special attention should be paid on genomics and

  2. 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.

  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. Environmentally persistent free radicals induce airway hyperresponsiveness in neonatal rat lungs

    Directory of Open Access Journals (Sweden)

    Lominiki Slawo

    2011-03-01

    Full Text Available Abstract Background Increased asthma risk/exacerbation in children and infants is associated with exposure to elevated levels of ultrafine particulate matter (PM. The presence of a newly realized class of pollutants, environmentally persistent free radicals (EPFRs, in PM from combustion sources suggests a potentially unrecognized risk factor for the development and/or exacerbation of asthma. Methods Neonatal rats (7-days of age were exposed to EPFR-containing combustion generated ultrafine particles (CGUFP, non-EPFR containing CGUFP, or air for 20 minutes per day for one week. Pulmonary function was assessed in exposed rats and age matched controls. Lavage fluid was isolated and assayed for cellularity and cytokines and in vivo indicators of oxidative stress. Pulmonary histopathology and characterization of differential protein expression in lung homogenates was also performed. Results Neonates exposed to EPFR-containing CGUFP developed significant pulmonary inflammation, and airway hyperreactivity. This correlated with increased levels of oxidative stress in the lungs. Using differential two-dimensional electrophoresis, we identified 16 differentially expressed proteins between control and CGUFP exposed groups. In the rats exposed to EPFR-containing CGUFP; peroxiredoxin-6, cofilin1, and annexin A8 were upregulated. Conclusions Exposure of neonates to EPFR-containing CGUFP induced pulmonary oxidative stress and lung dysfunction. This correlated with alterations in the expression of various proteins associated with the response to oxidative stress and the regulation of glucocorticoid receptor translocation in T lymphocytes.

  5. Formation of fluorescent polydopamine dots from hydroxyl radical-induced degradation of polydopamine nanoparticles.

    Science.gov (United States)

    Lin, Jia-Hui; Yu, Cheng-Ju; Yang, Ya-Chun; Tseng, Wei-Lung

    2015-06-21

    This study describes the synthesis of fluorescent polydopamine dots (PDs) through hydroxyl radical-induced degradation of polydopamine nanoparticles. The decomposition of polydopamine nanoparticles to fluorescent PDs was confirmed using transmission electron microscopy and dark-field microscopy. The analysis of PDs by using laser desorption/ionization time-of-flight mass spectrometry revealed that the PDs consisted of dopamine, 5,6-dihydroxyindole, and trihydroxyindole units. Oligomerization and self-assembly of these units produced a broad adsorption band, resulting in an excitation-wavelength-dependent emission behavior. The maximal fluorescence of PDs appeared at 440 nm with a quantum yield of 1.2%. The coordination between the catechol groups of PDs and ferric ions (Fe(3+)) quenched the fluorescence of PDs; the limit of detection at a signal-to-noise ratio of 3 for Fe(3+) was determined to be 0.3 μM. The presence of pyrophosphate switched on the fluorescence of the PD-Fe(3+) complexes. Compared to the other reported methods for sensing Fe(3+), PDs provided simple, low-cost, and reusable detection of Fe(3+).

  6. Laser-induced fluorescence and dispersed fluorescence spectroscopy of jet-cooled 1-phenylpropargyl radical.

    Science.gov (United States)

    Reilly, Neil J; Nakajima, Masakazu; Gibson, Bligh A; Schmidt, Timothy W; Kable, Scott H

    2009-04-14

    The D(1)((2)A("))-D(0)((2)A(")) electronic transition of the resonance-stabilized 1-phenylpropargyl radical, produced in a jet-cooled discharge of 3-phenyl-1-propyne, has been investigated in detail by laser-induced fluorescence excitation and dispersed single vibronic level fluorescence (SVLF) spectroscopy.The transition is dominated by the origin band at 21,007 cm(-1), with weaker Franck-Condon activity observed in a(') fundamentals and even overtones and combinations of a(") symmetry. Ab initio and density functional theory calculations of the D(0) and D(1) geometries and frequencies were performed to support and guide the experimental assignments throughout. Analysis of SVLF spectra from 16 D(1) vibronic levels has led to the assignment of 15 fundamental frequencies in the excited state and 19 fundamental frequencies in the ground state; assignments for many more normal modes not probed directly by fluorescence spectroscopy are also suggested. Duschinsky mixing, in which the excited state normal modes are rotated with respect to the ground state modes, is prevalent throughout, in vibrations of both a(') and a(") symmetry.

  7. Visible light-induced OH radicals in Ga2O3: an EPR study.

    Science.gov (United States)

    Tzitrinovich, Zeev; Lipovsky, Anat; Gedanken, Aharon; Lubart, Rachel

    2013-08-21

    Reactive oxygen species (ROS) were found to exist in water suspensions of several metal oxide nanoparticles (NPs), such as CuO, TiO2 and ZnO. Visible light irradiation enhanced the capability of TiO2 and ZnO NPs to generate ROS, thus increasing their antibacterial effects. Because of the possible toxic effects on the host tissue it is desired to find nano-metal oxides which do not produce ROS under room light, but only upon a strong external stimulus. Using the technique of electron-spin resonance (ESR) coupled with spin trapping, we examined the ability of Ga2O3 submicron-particle suspensions in water to produce reactive oxygen species with and without visible light irradiation. We found that in contrast to ZnO and TiO2 NPs, no ROS are produced by Ga2O3 under room light. Nevertheless blue light induced hydroxyl radical formation in Ga2O3. This finding might suggest that NPs of Ga2O3 could be used safely for infected skin sterilization.

  8. Effects of gamma-ray-induced free radicals on the metal content and ...

    Indian Academy of Sciences (India)

    MTs are involved in metal homeostasis and heavy metal detoxification, and are efficient scavengers of free radicals. This article describes zinc release from human MT-1 and modification of its amino acid composition when subjected to free radicals generated during gamma ray radiolysis. The effect of gamma ray radiolysis ...

  9. Chemoprevention of Radiation Induced Rat Mammary Neoplasms

    Science.gov (United States)

    Huso, David L.

    1999-01-01

    Radiations encountered in space include protons and heavy ions such as iron as well as their secondaries. The relative biological effect (RBE) of these ions is not known, particularly at the doses and dose-rates expected for planetary missions. Neutrons, are not particularly relevant to space travel, but have been found experimentally to have an increase in their RBE with decreasing dose. If a similar trend of increasing RBE with decreasing dose is present for heavy ions and protons during irradiation in space, the small doses received during space travel could potentially have substantial carcinogenic risk. Clearly more investigation of the effects of heavy ions and protons is needed before accurate risk assessment for prolonged travel in space can be done. One means to mitigate the increased risk of cancer due to radiation exposure in space is by developing effective countermeasures that can reduce the incidence of tumor development. Tamoxifen has recently been shown to be an effective chemopreventive agent in both animal models and humans for the prevention of mammary tumors. Tamoxifen is a unique drug, with a highly specific mechanism of action affecting a specific radiation-sensitive population of epithelial cells in the mammary gland. In human studies, the annual incidence of a primary tumor in the contralateral breast of women with previous breast cancer is about 8 per 1000, making them an exceedingly high-risk group for the development of breast cancer. In this high risk group, treated with tamoxifen, daily, for 2 years, the incidence of a new primary tumor in the contralateral breast was approximately one third of that noted in the non-tamoxifen treatment group. Tamoxifen antagonizes the action of estrogen by competing for the nuclear receptor complex thereby altering the association of the receptor complex and nuclear binding sites. Its effects in reducing the development of breast cancer could be accomplished by controlling clinically undetectable

  10. H- - H Collision Induced Radiative Transitions

    Science.gov (United States)

    Dadonova, A. V.; Devdariani, A. Z.

    2012-12-01

    Exchange interaction leads to the formation of gerade and ungerade states of temporary molecules (quasimolecules) formed during the H- +H slow collisions. The work deals with the radiation produced by optical transitions between those states. The main characteristics involved in the description of optical transitions in quasimolecules, i.e., energy terms, an optical dipole transition moments, have been calculated in the frame of zero-range potentials model. The main feature of calculations is that the results can be expressed analytically in closed forms via the Lambert W function.

  11. Case report of radiation-induced rectal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Karaki, Y.; Nagase, T.; Hokari, I.; Hasegawa, A.; Tazawa, K. (Toyama Medical and Pharmaceutical Univ. (Japan). Faculty of Medicine)

    1982-09-01

    A 70-year-old woman who had been treated by irradiation of unknown dose for cervical carcinoma of uterus 27 years before, was admitted in our hospital. Barium enema and romanoscope with rectal biopsy revealed rectal carcinoma with narrow recto-sigmoidal segment and procto-ilela fistula. Sections from resected specimen showed mucinous adenocarcinoma of the rectum with severe disorganization around the cancer lesion such as fibrosis, ulcer and vascular degeneration as a possible effect of previous irradiation. Radiation-induced carcinomas of the large intestine previously reported in the literatures were reviewed and the problems of the criteria of so-called radiation induced malignancy were discussed.

  12. Radiation-induced endometriosis in Macaca mulatta

    Energy Technology Data Exchange (ETDEWEB)

    Fanton, J.W.; Golden, J.G. (USAF School of Aerospace Medicine, Brooks AFB, TX (USA))

    1991-05-01

    Female rhesus monkeys received whole-body doses of ionizing radiation in the form of single-energy protons, mixed-energy protons, X rays, and electrons. Endometriosis developed in 53% of the monkeys during a 17-year period after exposure. Incidence rates for endometriosis related to radiation type were: single-energy protons, 54%; mixed-energy protons, 73%; X rays, 71%; and electrons, 57%. The incidence of endometriosis in nonirradiated control monkeys was 26%. Monkeys exposed to single-energy protons, mixed-energy protons, and X rays developed endometriosis at a significantly higher rate than control monkeys (chi 2, P less than 0.05). Severity of endometriosis was staged as massive, moderate, and minimal. The incidence of these stages were 65, 16, and 19%, respectively. Observations of clinical disease included weight loss in 43% of the monkeys, anorexia in 35%, space-occupying masses detected by abdominal palpation in 55%, abnormal ovarian/uterine anatomy on rectal examination in 89%, and radiographic evidence of abdominal masses in 38%. Pathological lesions were endometrial cyst formation in 69% of the monkeys, adhesions of the colon in 66%, urinary bladder in 50%, ovaries in 86%, and ureters in 44%, focal nodules of endometrial tissue throughout the omentum in 59%, and metastasis in 9%. Clinical management of endometriosis consisted of debulking surgery and bilateral salpingo-oophorectomy combined in some cases with total abdominal hysterectomy. Postoperative survival rates at 1 and 5 years for monkeys recovering from surgery were 48 and 36%, respectively.

  13. Possible Radiation Sensitisation by Trastuzumab Leading to Radiation-Induced Myelitis.

    Science.gov (United States)

    Law, Alastair B; Evans, Tamasin; Hayward, Richard L; Higgins, Geoffrey S; Murray, Katherine L; Summers, David; Kunkler, Ian H

    2009-01-01

    SUMMARY: BACKGROUND: Trastuzumab is used as adjuvant treatment in patients with HER2-positive breast cancers and has been shown to reduce the chance of recurrence by up to 50%. However, experience with it given with radiotherapy is limited and there is in vitro evidence of a radiosensiti-sation effect. We describe the first case of trastuzumab-associated radiation-induced myelitis. CASE REPORT: This patient received a calculated dose of 28 Gy to the spinal cord when receiving adjuvant radiotherapy to the chest wall and supraclavicular and axillary lymph nodes. This is well below the accepted radiation tolerance of the spinal cord (50-60 Gy) but she developed radiation-induced myelitis of her spinal cord with characteristic magnetic resonance imaging changes. We postulate that trastuzu-mab given concurrently with radiation may have acted as a radiosensitiser and that normal repair mechanisms in the acute stage were affected by trastuzumab blockage of epidermal growth factor receptors, resulting in demy-elination at a lower dose of radiation than normally seen. CONCLUSIONS: Concomitant radiotherapy and adjuvant trastuzumab treatment should be given with caution and consideration made of delaying trastuzumab until after radiotherapy has been completed. As longer-term data become available for patients who received trastuzumab and radiation, it will become clearer whether there is a significant interaction on organs such as the heart and spinal cord in the radiation field.

  14. Radiation induced effects in segmented poly(siloxaneurethaneureas) based on aliphatic and aromatic diisocyanates

    Energy Technology Data Exchange (ETDEWEB)

    Przybytniak, Grazyna [Institute of Nuclear Chemistry and Technology, ul. Dorodna 16, 03-195 Warsaw (Poland)], E-mail: przybyt@ichtj.waw.pl; Kornacka, Ewa [Institute of Nuclear Chemistry and Technology, ul. Dorodna 16, 03-195 Warsaw (Poland); Kozakiewicz, Janusz; Przybylski, Jaroslaw [Industrial Chemistry Research Institute, ul. Rydygiera 8, 01-793 Warsaw (Poland)

    2007-12-15

    Poly(siloxaneurethaneureas) (PSURURs) prepared from aromatic and aliphatic isocyanates were investigated upon exposure to ionising radiation. Radicals are formed both in siloxane and urethane segments. In comparison with aliphatic analogues it was found that in aromatic PSURURs: (1) concentration of all radicals is lower, (2) relative concentration of methylene radicals formed in siloxane units is higher, (3) the radiation yield of H{sub 2} is more than three times smaller and (4) it seems that efficiency of cross-linking is less significant.

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

    Energy Technology Data Exchange (ETDEWEB)

    Umatani, Katsunori; Satoh, Takeo; Yoshino, Kunitoshi; Takagi, Tadashi; Fujii, Takashi; Hatta, Chihiro; Maetani, Chikahide; Lu, Bo (Osaka Prefectural Center for Adult Diseases (Japan))

    1989-08-01

    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).

  16. Number of metastatic lymph nodes as determinant of outcome after salvage radical prostatectomy for radiation-recurrent prostate cancer.

    Science.gov (United States)

    Gugliemetti, G; Sukhu, R; Conca Baenas, M A; Meeks, J; Sjoberg, D D; Eastham, J A; Scardino, P T; Touijer, K

    2016-09-01

    Presence of lymph node metástasis (LNM) at salvage radical prostatectomy (sRP) is associated with poor outcome. Predictors of outcome in this context remain undetermined. ThE objective was to assess the role of number of positive lymph node on outcome of patients with LNM after sRP and for radio-recurrent prostate cancer. We analyzed data from a consecutive cohort of 215 men treated with sRP at a single institution. We used univariate Cox proportional hazard regression models for biochemical recurrence (BCR) and metastatic outcomes, with prostate-specific antigen, Gleason score, extraprostatic extension, seminal vesicle invasion, time between radiation therapy and sRP, and number of positive nodes as predictors. Of the 47 patients with LNM, 37 developed BCR, 11 developed distant metastasis and 4 died with a median follow-up of 2.3 years for survivors. The risk of metastases increased with higher pre-operative PSA levels (HR 1.19 per 1ng/ml; 95% CI: 1.06-1.34; P=.003). The remaining predictors did not reach conventional levels of significance. However, removal of 3 or more positive lymph nodes demonstrated a positive association, as expected, with metastatic disease (HR 3.44; 95% CI: 0.91-13.05; P=.069) compared to one or 2 positive nodes. Similarly, the presence of extraprostatic extension, seminal vesicle invasion and Gleason grade greater than 7 also demonstrated a positive association with higher risk of metástasis, with hazard ratios of 3.97 (95% CI: 0.50, 31.4; P=.2), 3.72 (95% CI: 0.80-17.26; P=.1), and 1.45 (95% CI: 0.44-4.76; P=.5), respectively. In patients with LNM after sRP for radio-recurrent prostate cancer, the risk of distant metástasis is likely to be influenced by the number of positive nodes (3 or more), high preoperative PSA, Gleason grade and advanced pathologic stage. These results are consistent with the findings of number of nodes (1 to 2 vs. 3 or more nodes positive) as a prognostic indicator after primary radical prostatectomy and

  17. Radiation-induced degassing of cryopumps

    Energy Technology Data Exchange (ETDEWEB)

    Graham, W.G.; Ruby, L.

    1978-06-01

    The pressure-gauge response of the system to the TRIGA pulses is shown. With an unloaded cryopump, an apparent pressure pulse is produced which is only slightly longer than the reactor pulse itself. In separate experiments, it was found that a similarly appearing pulse is produced by a completely sealed-off vacuum gauge. With a deuterium-loaded cryopump, a very much larger pressure pulse was produced, which had a long exponential tail, characteristic of a re-pumpdown of the system. The pumping speed, as computed from the exponential, is about half that observed previously when the cryopump was subjected to D/sub 2/-gas pulses, in the absense of radiation. Additional experiments were run with the core of the reactor retracted somewhat into the pool, in order to change the mix of gamma rays, thermal neutrons, and fast neutrons so as to preferentially depress the latter.

  18. 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

  19. Site reactivity in the free radicals induced damage to leucine residues: a theoretical study.

    Science.gov (United States)

    Medina, M E; Galano, A; Alvarez-Idaboy, J R

    2015-02-21

    Several recent computational studies have tried to explain the observed selectivity in radical damage to proteins. In this work we use Density Functional Theory and Transition State Theory including tunnelling corrections, reaction path degeneracy, the effect of diffusion, and the role of free radicals to get further insights into this important topic. The reaction between a leucine derivative and free radicals of biological significance, in aqueous and lipid media, has been investigated. Both thermochemical and kinetic analyses, in both hydrophilic and hydrophobic environments, have been carried out. DPPH, ˙OOH, ˙OOCH3, ˙OOCH2Cl, ˙OOCHCl2 and ˙OOCHCH2 radicals do not react with the target molecule. The reactions are proposed to be kinetically controlled. The leucine gamma site was the most reactive for the reactions with ˙N3, ˙OOCCl3, ˙OCH3, ˙OCH2Cl, and ˙OCHCl2 radicals, with rate constants equal to 1.97 × 10(5), 3.24 × 10(4), 6.68 × 10(5), 5.98 × 10(6) and 8.87 × 10(8) M(-1) s(-1), respectively, in aqueous solution. The ˙Cl, ˙OH and ˙OCCl3 radicals react with leucine at the beta, gamma, and delta positions at rates close to the diffusion limit with the alpha position which is the slowest path and the most thermodynamically favored. The presented results confirm that the Bell-Evans-Polanyi principle does not apply for the reactions between amino acid residues and free radicals. Regarding the influence of the environment on the reactivity of the studied series of free radicals towards leucine residues, it is concluded that hydrophilic media slightly lower the reactivity of the studied radicals, compared to hydrophobic ones, albeit the trends in reactivity are very similar.

  20. Ion-Induced Radiation Damage in Biomolecular Systems

    Science.gov (United States)

    Schlathölter, Thomas

    The interaction of keV ions with building blocks of DNA and proteins is of fundamental interest to proton and heavy ion therapy. During the last decade, ion-induced ionization and fragmentation was studied for isolated biomolecules, biomolecular clusters, nanosolvated isolated biomolecules and solid thin biomolecular films. This article gives a brief overview over the research on biomolecular mechanisms underlying ion-induced radiation damage with a focus on the different target systems.

  1. Radiation Induced Immune Response in Prostate Cancer

    Science.gov (United States)

    2014-12-01

    dependent cell- mediated phagocytosis ( ADCP ). This research will allow us to characterize antigens and antibodies intended for clinical trials in patients...Moreover, TIP1 is inducible in nearly all mouse models of cancer resulting in opsonization and activation of ADCC and ADCP . Antibodies that we...antibody-dependent cell-mediated phagocytosis ( ADCP ). ScFv antibodies Overall Project Summary Subtask 1.1 Binding of antibodies to irradiated

  2. Roles of oxygen radicals and elastase in citric acid-induced airway constriction of guinea-pigs

    OpenAIRE

    Lai, Y -L; Chiou, W -Y; Lu, F. J.; Chiang, L. Y

    1999-01-01

    Antioxidants attenuate noncholinergic airway constriction. To further investigate the relationship between tachykinin-mediated airway constriction and oxygen radicals, we explored citric acid-induced bronchial constriction in 48 young Hartley strain guinea-pigs, divided into six groups: control; citric acid; hexa(sulphobutyl)fullerenes+citric acid; hexa(sulphobutyl)fullerenes+phosphoramidon+citric acid; dimethylthiourea (DMTU)+citric acid; and DMTU+phosphoramidon+citric acid. Hexa(sulphobutyl...

  3. An Ethanol Extract Derived from Bonnemaisonia hamifera Scavenges Ultraviolet B (UVB Radiation-Induced Reactive Oxygen Species and Attenuates UVB-Induced Cell Damage in Human Keratinocytes

    Directory of Open Access Journals (Sweden)

    Nam Ho Lee

    2012-12-01

    Full Text Available The present study investigated the photoprotective properties of an ethanol extract derived from the red alga Bonnemaisonia hamifera against ultraviolet B (UVB-induced cell damage in human HaCaT keratinocytes. The Bonnemaisonia hamifera ethanol extract (BHE scavenged the superoxide anion generated by the xanthine/xanthine oxidase system and the hydroxyl radical generated by the Fenton reaction (FeSO4 + H2O2, both of which were detected by using electron spin resonance spectrometry. In addition, BHE exhibited scavenging activity against the 1,1-diphenyl-2-picrylhydrazyl radical and intracellular reactive oxygen species (ROS that were induced by either hydrogen peroxide or UVB radiation. BHE reduced UVB-induced apoptosis, as shown by decreased apoptotic body formation and DNA fragmentation. BHE also attenuated DNA damage and the elevated levels of 8-isoprostane and protein carbonyls resulting from UVB-mediated oxidative stress. Furthermore, BHE absorbed electromagnetic radiation in the UVB range (280–320 nm. These results suggest that BHE protects human HaCaT keratinocytes against UVB-induced oxidative damage by scavenging ROS and absorbing UVB photons, thereby reducing injury to cellular components.

  4. Synthesis of a Novel Nitronyl Nitroxide Radical and Determination of its Protective Effects Against Infrasound-Induced Injury.

    Science.gov (United States)

    Wang, Haibo; Wang, Jin; Yang, Qi; Zhang, Xinwei; Gao, Peng; Xu, Shenglong; Sun, XiaoLi; Wang, YuKun

    2015-07-01

    Infrasound causes functional disorders and structural injury to the central nervous system. However, few anti-infrasound drugs exist, and they are inefficient. Nitronyl nitroxide radicals have been reported to be good antioxidants that act as superoxide dismutase mimics and directly react with reactive oxygen species, such as ·OH, H2O2, and O 2 (∙) -. Our previous research showed that the nitronyl nitroxide radical L-NNNBP has good protective effects against β-amyloid deposition and memory deficits in an AD rat model of APP/PS1. The objective of the present study was to find a new group of anti-infrasound drugs and determine the underlying pharmacological actions of nitronyl nitroxide radicals against infrasound-induced neuronal impairment in vivo. We synthesized a new stable nitronyl nitroxide radical, NRbt, and characterized its crystal structure. The results of the anti-oxidative damage effects of NRbt and the positive control drug tempol showed that they could significantly increase the SOD activity, CAT activity and GSH level and decrease the MDA level in rat hippocampi compared with infrasound exposure without pretreatment. Moreover, the ability of NRbt to regulate the activity or level of these biochemical markers was better than that of tempol. Our results showed that both NRbt and tempol significantly protected against the learning and memory impairments induced by infrasound exposure in a Morris water maze, but there were no significant differences in the path length or escape latency between the rats in the tempol group and the three NRbt groups (P > 0.05). In addition, the infrasound-induced neuronal apoptosis in rat hippocampi was significantly suppressed by NRbt and tempol. The results demonstrated that compared with the infrasound exposure group, the expression of Bcl-2 was up-regulated and the expressions of Bax and caspase-3 were down-regulated in rats pretreated with NRbt (40 mg/kg) or tempol (40 mg/kg). These results showed that the newly

  5. Radiation-induced DNA damage and chromatin structure

    Science.gov (United States)

    Rydberg, B.; Chatterjee, A. (Principal Investigator)

    2001-01-01

    DNA lesions induced by ionizing radiation in cells are clustered and not randomly distributed. For low linear energy transfer (LET) radiation this clustering occurs mainly on the small scales of DNA molecules and nucleosomes. For example, experimental evidence suggests that both strands of DNA on the nucleosomal surface can be damaged in single events and that this damage occurs with a 10-bp modulation because of protection by histones. For high LET radiation, clustering also occurs on a larger scale and depends on chromatin organization. A particularly significant clustering occurs when an ionizing particle traverses the 30 nm chromatin fiber with generation of heavily damaged DNA regions with an average size of about 2 kbp. On an even larger scale, high LET radiation can produce several DNA double-strand breaks in closer proximity than expected from randomness. It is suggested that this increases the probability of misrejoining of DNA ends and generation of lethal chromosome aberrations.

  6. Radiation Induced Hypoplasia of the Mandible and Retarded Tooth Development

    Directory of Open Access Journals (Sweden)

    Monica Tuteja

    2010-01-01

    Full Text Available Few cases of radiation-induced damage to the teeth and jaws, have been reported in the literature. Radiation therapy plays an important role in the treatment of patients affected with head and neck cancer. In spite of its recognized benefits in the treatment of malignant tumors, radiation therapy has several side-effects in the head and neck region. This paper highlights a case report where hypoplasia of the mandible, trismus and stunted permanent teeth roots were observed in an 18-year-old patient who was diagnosed with parameningeal rhabdomyosarcoma—embryonal type group III at the age of 5 years. He had received radiation therapy of 50 Gy to the nasopharynx for about 1 year and was reviewed for a period of 11 years. Full mouth periapical radiographs and panoramic radiograph revealed hypoplasia of the mandible and generalized hypoplasia of the roots of the permanent teeth.

  7. The impact of locally multiply damaged sites (LMDS) induced by ionizing radiation in mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Averbeck, D.; Boucher, D. [Institut Curie-Section de Recherche, UMR2027 CNRS, LCR-V28 du CEA, Centre Universitaire, 91405 Orsay Cedex (France)

    2006-07-01

    into DNA strand-breaks we were able to show that uncontrolled oxidation of DNA during cell lysis and DNA extraction gives rise to artificial DSB. If one avoids this oxidation by adding an antioxidant and/or an iron chelating agent (to inhibit possible Fenton reactions and the formation of OH radicals) before cell-lysis, the amount of LMDS decreases to very low, nearly insignificant levels. This holds for mammalian cells after low LET and high LET radiation (Ar+ ions). The induction of LMDS turned out to be neither dose- nor dose-rate dependent. Furthermore, we demonstrate that additional DSB, i.e. 'LMDS' can be detected by PFGE and enzymatic treatment when adding H{sub 2}O{sub 2} during cell-lysis. Thus, it is clear that the actual method used for the detection of these lesions induced in living cells is inadequate and that there is at present no firm experimental evidence for the presence of LMDS composed of oxidative damage after low or high LET irradiation in mammalian cells that can be related to radiation responses. At present, other possible approaches are tested that might allow a better definition of complex radiation-induced lesions in mammalian cells such as complex DSB. (authors)

  8. Effect of radiation-induced modification in fluoroelastomer

    Energy Technology Data Exchange (ETDEWEB)

    Zen, Heloisa Augusto; Lugao, Ademar Benevolo, E-mail: helozen@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Polymers exposed to ionizing irradiation, even at low doses, often undergo structural changes accompanied by molecular crosslinking and chain scission (degradation) reactions. The general effect of the radiation on polymers is determined by the ratio of crosslinking to chain scission events. This ratio depends on parameters such as chemical structure, physical state, radicals stability and mobility, irradiation rate and irradiation atmosphere. The radiation process is a large used technique to promote modification in their structures to apply them in different areas and is well known for its merits and potential in modifying the chemical and the physical properties of polymeric materials without cause drastic changes in their inherent properties, depend on the dose irradiated. In this study was used fluoroelastomer with 70% - fluor that having excellent thermal, chemical and mechanical properties. Vulcanized and non-vulcanized samples of this material were submitted to gamma radiation under air atmosphere in order to observe the effect of atmosphere in the polymer matrix. The irradiated doses were 5, 10 and 20kGy, at room temperature. The characterization was made by scanning electron microscope (SEM), infrared spectroscopy using attenuate reflectance (ATR-IR) and X-ray diffraction. The results demonstrated which was expected, the degradation reactions were observed. (author)

  9. Blackbody-induced radiative dissociation of cationic SF 6 clusters

    DEFF Research Database (Denmark)

    Toker, Jonathan; Rahinov, I.; Schwalm, D.

    2012-01-01

    The stability of cationic SF5+(SF6)n−1 clusters was investigated by measuring their blackbody-induced radiative dissociation (BIRD) rates. The clusters were produced in a supersonic expansion ion source and stored in an electrostatic ion-beam trap at room temperature, where their abundances...... and stability of SF6-based clusters....

  10. Radiation-induced femoral head necrosis | Abdulkareem | Nigerian ...

    African Journals Online (AJOL)

    There are very few cases of radiation-induced femoral head necrosis described in the literature, therefore, this case will add new knowledge and highlights important aspects in the diagnosis and management of this uncommon condition. Our patient was 74 years old and presented with left hip and groin pain for 8 months, ...

  11. Coherent Cherenkov Radiation from Cosmic-Ray-Induced Air Showers

    NARCIS (Netherlands)

    de Vries, K. D.; van den Berg, A. M.; Scholten, O.; Werner, K.

    2011-01-01

    Very energetic cosmic rays entering the atmosphere of Earth will create a plasma cloud moving with almost the speed of light. The magnetic field of Earth induces an electric current in this cloud which is responsible for the emission of coherent electromagnetic radiation. We propose to search for a

  12. Hyperbaric oxygen therapy for refractory radiation-induced hemorrhagic cystitis.

    Science.gov (United States)

    Ribeiro de Oliveira, Tiago M; Carmelo Romão, António J; Gamito Guerreiro, Francisco M; Matos Lopes, Tomé M

    2015-10-01

    To analyze the efficacy of hyperbaric oxygen for the treatment of radiation-induced hemorrhagic cystitis and to identify factors associated with successful treatment. Clinical records from 176 patients with refractory radiation-induced hemorrhagic cystitis treated at the Portuguese Navy Center for Underwater and Hyperbaric Medicine, during a 15-year period, were retrospectively analyzed. Evolution of macroscopic hematuria was used to analyze treatment efficacy and correlated with other external variables. From a total of 176 treated patients, 23.9% evidenced other radiation-induced soft tissue lesions. After an average on 37 sessions, 89.8% of patients showed resolution of hematuria, with only 1.7% of adverse events. In our sample, hematuria resolution after treatment with hyperbaric oxygen was statistically associated to the need for transfusion therapy (P = 0.026) and the number of sessions of hyperbaric oxygen (P = 0.042). No relationship was found with the remaining variables. Refractory radiation-induced hemorrhagic cystitis can be successfully and safely treated with hyperbaric oxygen. Treatment effectiveness seems to be correlated with the need for transfusion therapy and the number of sessions performed. © 2015 The Japanese Urological Association.

  13. Radiation-induced vascular lesions of the skin: an overview

    NARCIS (Netherlands)

    Flucke, U.E.; Requena, L.; Mentzel, T.

    2013-01-01

    Radiation-induced cutaneous vascular neoplasms occur infrequently and comprise benign, so-called atypical vascular lesions (AVL) and angiosarcomas (AS), often being high-grade malignant tumors. Both arise most frequently within previously irradiated skin in breast-conserving-treated mammary cancer

  14. 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.

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

    African Journals Online (AJOL)

    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 radiotherapy for head and neck malignancies can cause a reduction of the 'mandibular space' and alteration of the morphometric measurements, viz.

  16. Mechanism of hydrogen peroxide-induced Cu,Zn-superoxide dismutase-centered radical formation as explored by immuno-spin trapping: the role of copper- and carbonate radical anion-mediated oxidations.

    Science.gov (United States)

    Ramirez, Dario C; Gomez Mejiba, Sandra E; Mason, Ronald P

    2005-01-15

    We have reinvestigated the biochemistry of H2O2-induced Cu,Zn-superoxide dismutase (SOD1)-centered radicals, detecting them by immuno-spin trapping. These radicals are involved in H2O2-induced structural and functional damage to SOD1, and their mechanism of generation depends on copper and/or (bi)carbonate (i.e., CO2, CO3(-2), or HCO3-). First, in the absence of DTPA and (bi)carbonate, Cu(II) was partially released and rebound at His, Cys, and Tyr residues in SOD1 with the generation of protein-copper-bound oxidants outside the SOD1 active site by reaction with excess H2O2. These species produced immuno-spin trapping-detectable SOD1-centered radicals associated with H2O2-induced active site ( approximately 5 and approximately 10 kDa fragments) and non-active site (smearing between 3 and 16 kDa) copper-dependent backbone oxidations and subsequent fragmentation of SOD1. Second, in the presence of DTPA, which inhibits H2O2-induced SOD1 non-active site fragmentation, (bi)carbonate scavenged the enzyme-bound oxidant at the SOD1 active site to produce the carbonate radical anion, CO3*-, thus protecting against active site SOD1 fragmentation. CO3*- diffuses and produces side chain oxidations forming DMPO-trappable radical sites outside the enzyme active site. Both mechanisms for generating immuno-spin trapping-detectable SOD1-centered radicals were susceptible to inhibition by cyanide and enhanced at high pH values. In addition, (bi)carbonate enhanced H2O2-induced SOD1 turnover as demonstrated by an enhancement in oxygen evolution and SOD1 inactivation. These results help clarify the free radical chemistry involved in the functional and structural oxidative damage to SOD1 by H2O2 with the intermediacy of copper- and CO3*--mediated oxidations.

  17. Mechanisms of radiation-induced gene responses

    Energy Technology Data Exchange (ETDEWEB)

    Woloschak, G.E.; Paunesku, T.

    1996-10-01

    In the process of identifying genes differentially expressed in cells exposed ultraviolet radiation, we have identified a transcript having a 26-bp region that is highly conserved in a variety of species including Bacillus circulans, yeast, pumpkin, Drosophila, mouse, and man. When the 5` region (flanking region or UTR) of a gene, the sequence is predominantly in +/+ orientation with respect to the coding DNA strand; while in the coding region and the 3` region (UTR), the sequence is most frequently in the +/-orientation with respect to the coding DNA strand. In two genes, the element is split into two parts; however, in most cases, it is found only once but with a minimum of 11 consecutive nucleotides precisely depicting the original sequence. The element is found in a large number of different genes with diverse functions (from human ras p21 to B. circulans chitonase). Gel shift assays demonstrated the presence of a protein in HeLa cell extracts that binds to the sense and antisense single-stranded consensus oligomers, as well as to the double- stranded oligonucleotide. When double-stranded oligomer was used, the size shift demonstrated as additional protein-oligomer complex larger than the one bound to either sense or antisense single-stranded consensus oligomers alone. It is speculated either that this element binds to protein(s) important in maintaining DNA is a single-stranded orientation for transcription or, alternatively that this element is important in the transcription-coupled DNA repair process.

  18. Functional properties of nisin-carbohydrate conjugates formed by radiation induced Maillard reaction

    Science.gov (United States)

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

    2012-12-01

    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.

  19. 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 PURPOSE: To investigate radiation-induced carotid and cerebral vascular injury and its relationship with radiation-induced temporal lobe necrosis in nasopharyngeal carcinoma (NPC patients. METHODS AND MATERIALS: 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. RESULTS: 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. CONCLUSION: 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.

  20. Consumption of peptide-included and free tryptophan induced by peroxyl radicals: A kinetic study.

    Science.gov (United States)

    Fuentes, E; López-Alarcón, C

    2014-10-01

    It is well-known that tryptophan residues are efficiently oxidized by peroxyl radicals, generating kynurenine, and N-formyl kynurenine as well as hydroperoxide derivatives as products. In the present work we studied the kinetic of such reaction employing free and peptide-included tryptophan. Two azocompounds were used to produce peroxyl radicals: AAPH (2,2'-Azobis(2-methylpropionamidine) dihydrochloride) and ABCVA (4,4'-Azobis(4-cyanovaleric acid)), which generate cationic and anionic peroxyl radicals, respectively. Tryptophan consumption was assessed by fluorescence spectroscopy and the reactions were carried out in phosphate buffer (75mM, pH 7.4) at 45°C. Only a slight effect of the peroxyl radical charge was evidenced on the consumption of free tryptophan and the dipeptide Gly-Trp. Employing AAPH as peroxyl radical source, at low free tryptophan concentrations (1-10µM) near 0.3 mol of tryptophan were consumed per each mol of peroxyl radicals introduced into the system. However, at high free tryptophan concentrations (100µM-1mM) such stoichiometry increased in a tryptophan concentration-way. At 1mM three moles of tryptophan were consumed per mol of AAPH-derived peroxyl radicals, evidencing the presence of chain reactions. A similar behavior was observed when di and tri-peptides (Gly-Trp, Trp-Gly, Gly-Trp-Gly, Trp-Ala, Ala-Trp-Ala) were studied. Nonetheless, at low initial concentration (5µM), the initial consumption rate of tryptophan included in the peptides was two times higher than free tryptophan. In contrast, at high concentration (1mM) free and peptide-included tryptophan showed similar initial consumption rates. These results could be explained considering a disproportionation process of tryptophanyl radicals at low free tryptophan concentrations, a process that would be inhibited when tryptophan is included in peptides. Copyright © 2014. Published by Elsevier Inc.

  1. 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)

  2. Radical Prostatectomy Versus Radiation and Androgen Deprivation Therapy for Clinically Localized Prostate Cancer: How Good Is the Evidence?

    Energy Technology Data Exchange (ETDEWEB)

    Roach, Mack, E-mail: mroach@radonc.ucsf.edu [Department of Radiation Oncology, University of California San Francisco, San Francisco, California (United States); Ceron Lizarraga, Tania L. [Department of Radiation Oncology, University of California San Francisco, San Francisco, California (United States); Lazar, Ann A. [Department of Radiation Oncology, University of California San Francisco, San Francisco, California (United States); Division of Oral Epidemiology and Dental Public Health, Division of Biostatistics, University of California San Francisco, San Francisco, California (United States)

    2015-12-01

    Purpose: The optimal treatment of clinically localized prostate cancer is controversial. Most studies focus on biochemical (PSA) failure when comparing radical prostatectomy (RP) with radiation therapy (RT), but this endpoint has not been validated as predictive of overall survival (OS) or cause-specific survival (CSS). We analyzed the available literature to determine whether reliable conclusions could be made concerning the effectiveness of RP compared with RT with or without androgen deprivation therapy (ADT), assuming current treatment standards. Methods: Articles published between February 29, 2004, and March 1, 2015, that compared OS and CSS after RP or RT with or without ADT were included. Because the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system emphasis is on randomized controlled clinical trials, a reliability score (RS) was explored to further understand the issues associated with the study quality of observational studies, including appropriateness of treatment, source of data, clinical characteristics, and comorbidity. Lower RS values indicated lower reliability. Results: Fourteen studies were identified, and 13 were completely evaluable. Thirteen of the 14 studies (93%) were observational studies with low-quality evidence. The median RS was 12 (range, 5-18); the median difference in 10-year OS and CSS favored RP over RT: 10% and 4%, respectively. In studies with a RS ≤12 (average RS 9) the 10-year OS and CSS median differences were 17% and 6%, respectively. For studies with a RS >12 (average RS 15.5), the 10-year OS and CSS median differences were 5.5% and 1%, respectively. Thus, we observed an association between low RS and a higher percentage difference in OS and CSS. Conclusions: Reliable evidence that RP provides a superior CSS to RT with ADT is lacking. The most reliable studies suggest that the differences in 10-year CSS between RP and RT are small, possibly <1%.

  3. Oh where OH where is Oh? Measuring the Elusive Hydroxyl Radical in the Atmosphere Using Laser-Induced Fluorescence

    Science.gov (United States)

    Stevens, Philip S.

    2016-06-01

    The hydroxyl radical (OH) plays a central role in the chemistry of the atmosphere. In addition to controlling the lifetimes of many trace gases important to issues of global climate change and stratospheric ozone depletion, the OH radical initiates the oxidation of carbon monoxide and volatile organic compounds which in the presence of nitrogen oxides can lead to the production of ground-level ozone and secondary organic aerosols, the primary components of photochemical smog. Accurate measurements of OH radical concentrations in the atmosphere can provide critical tests of our understanding of atmospheric chemistry and ground-level ozone production in urban and rural areas. Because of its high reactivity, mixing ratios of OH in the atmosphere are extremely low (typically less than 0.1 parts per trillion) and its chemical lifetime very short (less than 1 second). As a result, measurements of OH present a serious analytical challenge, especially on the timescale necessary to test our understanding of the fast photochemistry of the atmosphere. This presentation will describe the Indiana University laser-induced fluorescence instrument for the sensitive detection of OH radicals in the atmosphere, including recent results from several measurement campaigns in both urban and rural environments.

  4. RNA decomposition by pyrite-induced radicals and possible role of lipids during the emergence of life

    Science.gov (United States)

    Cohn, Corey A.; Borda, Michael J.; Schoonen, Martin A.

    2004-09-01

    Generation of radical species (e.g., hydroxyl radical rad OH) by silicates is well documented, and it has been shown that these radicals can readily destroy biomolecules. While quartz and asbestos have received considerable attention, pyrite (FeS 2), the most abundant iron sulfide, has received almost no attention in this context. Batch experiments were performed to determine the effects of pyrite-induced rad OH on RNA in the presence and absence of lipids. The effect of the presence of lipids on RNA stability was evaluated by coating pyrite as well as encapsulating RNA in bilayer-vesicles. Rapid degradation of RNA was observed in the presence of pyrite, whereas significantly slower RNA decomposition was observed in experiments in the presence of lipids, regardless of whether the lipids were coating the pyrite or encapsulating the RNA. Given the presence of pyrite on early Earth, its reaction with water may have formed hydroxyl radicals ( rad OH), which could have limited the stability of prebiotic biomolecules critical to the emergence and evolution of life. The lipid-mediated reduction of RNA decomposition suggests a possible protective mechanism that could have been a prerequisite for the origin of life.

  5. Radical kinetics and characterization of the free radicals in gamma irradiated red pepper

    Energy Technology Data Exchange (ETDEWEB)

    Korkmaz, M. E-mail: polat@hacettepe.edu.tr; Polat, M

    2001-12-01

    Kinetic behaviors and characterization of the natural and {gamma}-induced radicals in irradiated red pepper have been investigated by electron spin resonance (ESR) spectroscopy to explore the possibility of using this technique in detecting irradiated red pepper and to evaluate the eventual dosimetric features of this widely used food. Unirradiated samples exhibited a single resonance line centered at g=2.0050{+-}0.0005. Photo-exposure of the samples was found to increase the signal intensity. An increase in temperature created a drastic decrease in the concentration of natural radicals responsible for the single resonance line. Irradiation was observed to induce increases in the intensity of single resonance line (signal I) and a radiation specific doublet and/or triplet (signal II) also centered at g=2.0050 but detectable only at high spectrometer gains. The intensities of both signals increased with increasing radiation dose. The signals I and II were found to decay with different rates depending on the temperature. The results of a fitting procedure applied to the experimental signal decay curves and those obtained from room temperature spectra simulation calculations were used together to determine radical species and their spectral characteristics giving rise to the observed experimental spectra. Four radical species, three carbohydrate and one semiquinone radical assigned as radicals A, B, C and D, respectively, were found to best explain the experimental results. All the radicals show large g and hyperfine splitting anisotropies varying between g=2.0028-2.0062 and 1.07-2.58 mT, respectively. The half lives of the radicals were found to depend strongly on temperature. The activation energy calculated using temperature dependent half-life data were the highest for radical A (33.68 kcal/mol) and smallest for radical C (11.83 kcal/mol)

  6. Design Methodologies and to Combat Radiation Induced Corruption in FPGAs and SoCs Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Traditional radiation hardened by process (RHBP) and radiation hardened by design (RHBD) techniques have seen success in mitigating the effects of radiation induced...

  7. Jatropha curcas leaf and bark fractions protect against ultraviolet radiation-B induced DNA damage in human peripheral blood lymphocytes.

    Science.gov (United States)

    Sundari, J; Selvaraj, R; Rajendra Prasad, N; Elumalai, R

    2013-11-01

    The present study is conducted to investigate the antioxidant potential of Jatropha curcas root bark extract (RB4 fraction) and leaf extract (L1 fraction), and to study their effects on UVB-radiation-induced DNA damage in cultured human blood lymphocytes. In this study, J. curcas showed strong antioxidant property in different free radical scavenging systems. Both the fractions effectively scavenged hydroxyl (OH), superoxide anion (O₂(·-)), 1,1-diphenyl-2-picrylhydrazyl (DPPH·) and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid radical cation (ABTS(·+)) in a concentration-dependent manner. The IC₅₀ (Inhibitory Concentration 50) values of J. curcas fractions were compared to standard ascorbic acid used in this study. The antioxidant potential of a compound was directly proportional to the photoprotective effect. In this study, human peripheral blood lymphocytes (HPBL) were exposed to UVB-radiation and there was an increase in comet attributes (% tail DNA, tail length, tail movement and Olive tail moment). Jatropha curcas RB4 fraction and L1 fraction treatment before UVB-irradiation significantly decreased the % tail DNA, tail length, tail moment and Olive tail moment in irradiated HPBL. These results suggested that J. curcas exhibited strong antioxidant property and RB4 and L1 fractions protected UVB-radiation-induced DNA damage in HPBL. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. 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.

  9. Multivariate analysis of the prognostic factors of squamous cell cervical cancer treated by radical hysterectomy or combined radiation therapy; Carcinoma espinocelular do colo uterino submetido a cirurgia radical isolada ou em combinacao com radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, Francisco Ricardo Gualda; Kowalski, Luiz Paulo; Abrao, Fauzer Simao [Fundacao Antonio Prudente, Sao Paulo, SP (Brazil). Hospital A.C. Camargo; Franco, Eduardo Luiz [McGill Univ., Montreal, PQ (Canada). Dept. of Oncology; Zeferino, Luiz Carlos [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Medicina; Brentani, Maria Mitzi [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina

    1996-04-01

    Six hundred and nine cases of invasive squamous cell carcinoma of the cervix uteri in a retrospective analysis (1953-1982) at the A.C. Camargo Hospital, Antonio Prudente Foundation, Sao Paulo, Brazil. The patients were submitted to radical surgery and radiation therapy, individually or in combination. A multivariate analysis of the different variables were performed according to the Cox`s regression method. The variables of prognosis value, in decreasing order of importance, were: the decade of patient`s admission, the modality of therapy employed, the presence of residual tumor in the surgical specimens and the clinical stage of the disease. Other variables like ethnic group, age of first menstrual flux, menopause, number of pregnancy, kind of delivery, number and kind of abortion, were found to be of no prognostic importance. The decade of admission was of independent prognostic significance. The presence of residual tumor in the surgical specimens was more important than lymph nodes spreading, but the overall survival was affected by the increase in the number of positive lymph nodes. Patient`s age was a weak prognostic factor accounting for a reduction in the survival time among cases with age upper to 45 years old. Radiation therapy sterilizes a considerable number of lymph nodes but not all of them in every patient. There are a specific group of patients where the radical surgery is necessary in order to carry a complete debulking of the disease. (author) 82 refs., 10 figs.

  10. Comparison of free radical formation induced by baicalein and pentamethyl-hydroxychromane in human promyelocytic leukemia cells using electron spin resonance

    Directory of Open Access Journals (Sweden)

    Yung-Kai Huang

    2014-09-01

    Full Text Available Baicalein and pentamethyl-hydroxychromane (PMC have been investigated for use as antioxidants. However, antioxidants may stimulate free radical formation under certain conditions. The aim of our study was to determine whether PMC and baicalein exhibit both pro-oxidant and antioxidant activities in human promyelocytic leukemia (HL-60 cells. In this study, electron spin resonance spectrometry was used to investigate the effects of baicalein and PMC on free radical formation. In HL-60 cells, baicalein and PMC produced hydroxyl and phenoxyl radicals, respectively, but each inhibited radical formation by the other. The PMC pro-oxidant activity required H2O2, whereas baicalein produced hydroxyl radicals during the cell resting state only. The antioxidant effect of baicalein on PMC-induced oxidative stress in HL-60 cells may involve myeloperoxidase inhibition, which produces the myeloperoxidase-protein radical. Our investigation of the antioxidant effects of baicalein on arachidonic acid (AA-induced oxidative stress in HL-60 cells showed that the baicalein-phenoxyl radical was the primary product, and that either carbon-centered or acyl radicals were the secondary products. However, the antioxidant effects of PMC on AA-induced oxidative stress produced only nonradical products. In conclusion, we showed that baicalein displayed both pro-oxidant and antioxidant activities in HL-60 cells. PMC exhibited no pro-oxidant activity during the cells' resting state but produced the PMC-phenoxyl radical in the presence of H2O2.The reaction of baicalein with AA in HL-60 cells produced baicalein-derived phenoxyl radicals that may initiate various pro-oxidative reactions. However, PMC does not produce radicals when it acts as an antioxidant. Thus, PMC is more beneficial as an antioxidant than baicalein.

  11. 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

  12. Challenges and Opportunities in Radiation-induced Hemorrhagic Cystitis

    Science.gov (United States)

    Zwaans, Bernadette M.M.; Nicolai, Heinz G.; Chancellor, Michael B.; Lamb, Laura E.

    2016-01-01

    As diagnosis and treatment of cancer is improving, medical and social issues related to cancer survivorship are becoming more prevalent. Hemorrhagic cystitis (HC), a rare but serious disease that may affect patients after pelvic radiation or systemic chemotherapy, has significant unmet medical needs. Although no definitive treatment is currently available, various interventions are employed for HC. Effects of nonsurgical treatments for HC are of modest success and studies aiming to control radiation-induced bladder symptoms are lacking. In this review, we present current and advanced therapeutic strategies for HC to help cancer survivors deal with long-term urologic health issues. PMID:27601964

  13. Planck's Radiation Law: Thermal Excitations of Vacuum Induced Fluctuations

    Directory of Open Access Journals (Sweden)

    Ogiba F.

    2015-04-01

    Full Text Available The second Planck’s radiation law is derived considering that “resonators” induced by the vacuum absorb thermal excitations as additional fluctuations. The maximum energy transfer, as required by the maximum entropy equilibrium, occurs when the frequencies of these two kind of vibrations are equal. The motion resembles that of the coherent states of the quantum oscillator, as originally pointed by Schrödinger [1]. The resulting variance, due to random phases, coincides with that used by Einstein to reproduce the first Planck’s radiation law from his thermal fluctuation equation [2].

  14. Radiation induced changes in alpha toxin of Staphylococcus aureus 3750

    Energy Technology Data Exchange (ETDEWEB)

    Sherekar, S.V.; Bhushan, B.; Gore, M.S. (Bhabha Atomic Research Centre, Bombay (India). Biochemistry and Food Technology Div.)

    1981-06-01

    Influence of ..gamma..-radiation and heat on haemolytic activity of purified alpha toxin from staphylococcus aureus 3750 cells was studied. Heat treatment at 60deg C for 1 min resulted in 99% inactivation of alpha toxin, while exposure to ..gamma..-radiation caused linear decline in activity, 40 krad causing 50% inactivation. Urea treatment reversed the heat induced inactivation but did not reactivate the irradiated toxin. However, the irradiated toxin retained its antigenicity, thus indicating its potential for the preparation of toxoid against alpha toxin.

  15. Radiation-induced volatile hydrocarbon production in platelets

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. Radiation-induced inhibition of RNA synthesis in Tetrahymena pyriformis.

    Science.gov (United States)

    Ernst, S G; Rustad, R C; Oleinick, N L

    1975-07-01

    Radiation-induced disturbances in RNA synthesis were investigated in exponentially growing Tetrahymena. Sub-lethal doses of gamma-radiation lead to a transient, dose-dependent decrease in the rate of total RNA synthesis measured by 3H-uridine incorporation, without an alteration of 3H-uridine uptake by the cells. The rate of 3H-uridine incorporation decreases exponentially with dose. In contrast, the duration of inhibition of RNA synthesis is linearly dependent on dose. Target-theory calculations suggest that the sensitive molecule has a molecular weight of about 2 X 10(7) Daltons.

  17. Radiation induced decomposition of a refractory cefathiamidine intermediate.

    Science.gov (United States)

    Bao, Qiburi; Chen, Lujun; Wang, Jianlong

    2014-12-01

    Diisopropylthiourea (DPT), an intermediate of a widely used cephalosporin, has been found to be one of the most refractory components in cephalosporin synthesis wastewater. This compound cannot be completely removed by conventional biological processes due to its antimicrobial property. Ionizing radiation has been applied in the decomposition of refractory pollutants in recent years and has proved effective. Therefore, the decomposition of DPT by γ-irradiation was studied. The compound was irradiated at the dose of 150-2000 Gy before a change of concentration and UV absorption of the solutions was detected. Furthermore, the decomposition kinetics and radiation yield (G-value) of DPT was investigated. The results of radiation experiments on DPT-containing aqueous showed that the DPT can be effectively degraded by γ-radiation. DPT concentration decreased with increasing absorbed doses. G-values of radiolytic decomposition for DPT (20 mg/L) were 1.04 and 0.47 for absorbed doses of 150 and 2000 Gy, respectively. The initial concentration and pH of the solutions affected the degradation. As the concentration of substrate increased, the decomposition was reduced. The decrease of removal rate and radiation efficacy under alkaline condition suggested that lower pH values benefit the γ-induced degradation. UV absorption from 190 to 250 nm decreased after radiation while that from 250 to 300 nm increased, indicating the formation of by-products. Copyright © 2014. Published by Elsevier B.V.

  18. RNAi Screen for NRF2 Inducers Identifies Targets That Rescue Primary Lung Epithelial Cells from Cigarette Smoke Induced Radical Stress.

    Directory of Open Access Journals (Sweden)

    Frances-Rose Schumacher

    Full Text Available Chronic Obstructive Pulmonary Disease (COPD is a highly prevalent condition characterized by inflammation and progressive obstruction of the airways. At present, there is no treatment that suppresses the chronic inflammation of the disease, and COPD patients often succumb to the condition. Excessive oxidative stress caused by smoke inhalation is a major driving force of the disease. The transcription factor NRF2 is a critical player in the battle against oxidative stress and its function is impaired in COPD. Increasing NRF2 activity may therefore be a viable therapeutic option for COPD treatment. We show that down regulation of KEAP1, a NRF2 inhibitor, protects primary human lung epithelial cells from cigarette-smoke-extract (CSE induced cell death in an established in vitro model of radical stress. To identify new potential drug targets with a similar effect, we performed a siRNA screen of the 'druggable' genome using a NRF2 transcriptional reporter cell line. This screen identified multiple genes that when down regulated increased NRF2 transcriptional activity and provided a survival benefit in the in vitro model. Our results suggest that inhibiting components of the ubiquitin-proteasome system will have the strongest effects on NRF2 transcriptional activity by increasing NRF2 levels. We also find that down regulation of the small GTPase Rab28 or the Estrogen Receptor ESRRA provide a survival benefit. Rab28 knockdown increased NRF2 protein levels, indicating that Rab28 may regulate NRF2 proteolysis. Conversely ESRRA down regulation increased NRF2 transcriptional activity without affecting NRF2 levels, suggesting a proteasome-independent mechanism.

  19. Countermeasures for Space Radiation Induced Malignancies and Acute Biological Effects

    Science.gov (United States)

    Kennedy, Ann

    The hypothesis being evaluated in this research program is that control of radiation induced oxidative stress will reduce the risk of radiation induced adverse biological effects occurring as a result of exposure to the types of radiation encountered during space travel. As part of this grant work, we have evaluated the protective effects of several antioxidants and dietary supplements and observed that a mixture of antioxidants (AOX), containing L-selenomethionine, N-acetyl cysteine (NAC), ascorbic acid, vitamin E succinate, and alpha-lipoic acid, is highly effective at reducing space radiation induced oxidative stress in both in vivo and in vitro systems, space radiation induced cytotoxicity and malignant transformation in vitro [1-7]. In studies designed to determine whether the AOX formulation could affect radiation induced mortality [8], it was observed that the AOX dietary supplement increased the 30-day survival of ICR male mice following exposure to a potentially lethal dose (8 Gy) of X-rays when given prior to or after animal irradiation. Pretreatment of animals with antioxidants resulted in significantly higher total white blood cell and neutrophil counts in peripheral blood at 4 and 24 hours following exposure to doses of 1 Gy and 8 Gy. Antioxidant treatment also resulted in increased bone marrow cell counts following irradiation, and prevented peripheral lymphopenia following 1 Gy irradiation. Supplementation with antioxidants in irradiated animals resulted in several gene expression changes: the antioxidant treatment was associated with increased Bcl-2, and decreased Bax, caspase-9 and TGF-β1 mRNA expression in the bone marrow following irradiation. These results suggest that modulation of apoptosis may be mechanistically involved in hematopoietic system radioprotection by antioxidants. Maintenance of the antioxidant diet was associated with improved recovery of the bone marrow following sub-lethal or potentially lethal irradiation. Taken together

  20. Radiation-induced transformations of isolated CH3CN molecules in noble gas matrices

    Science.gov (United States)

    Kameneva, Svetlana V.; Volosatova, Anastasia D.; Feldman, Vladimir I.

    2017-12-01

    The transformations of isolated CH3CN molecules in various solid noble-gas matrices (Ne, Ar, Kr, and Xe) under the action of X-ray irradiation at 5 K were investigated by FTIR spectroscopy. The main products are CH3NC, CH2CNH and CH2NCH molecular isomers as well as CH2CN and CH2NC radicals. The matrix has a strong effect on the distribution of reaction channels. In particular, the highest relative yield of keteneimine (CH2CNH) was found in Ne matrix, whereas the formation of CH3NC predominates in xenon. It was explained by differences in the matrix ionization energy (IE) resulting in different distributions of hot ionic reactions. The reactions of neutral excited states are mainly involved in Xe matrix with low IE, while the isomerization of the primary acetonitrile positive ions may be quite effective in Ne and Ar. Annealing of the irradiated samples results in mobilization of trapped hydrogen atoms followed by their reactions with radicals to yield parent molecule and its isomers. The scheme of the radiation-induced processes and its implications for the acetonitrile chemistry in cosmic ices are discussed.

  1. OH-radical induced degradation of hydroxybenzoic- and hydroxycinnamic acids and formation of aromatic products-A gamma radiolysis study

    Energy Technology Data Exchange (ETDEWEB)

    Krimmel, Birgit; Swoboda, Friederike [University of Vienna, Department of Nutritional Sciences, Section Radiation Biology (Austria); Solar, Sonja, E-mail: sonja.solar@univie.ac.a [University of Vienna, Department of Nutritional Sciences, Section Radiation Biology (Austria); Reznicek, Gottfried [Department of Pharmacognosy, Althanstrasse 14, A-1090 Vienna (Austria)

    2010-12-15

    The OH-radical induced degradation of hydroxybenzoic acids (HBA), hydroxycinnamic acids (HCiA) and methoxylated derivatives, as well as of chlorogenic acid and rosmarinic acid was studied by gamma radiolysis in aerated aqueous solutions. Primary aromatic products resulting from an OH-radical attachment to the ring (hydroxylation), to the position occupied by the methoxyl group (replacement -OCH{sub 3} by -OH) as well as to the propenoic acid side chain of the cinnamic acids (benzaldehyde formations) were analysed by HPLC-UV and LC-ESI-MS. A comparison of the extent of these processes is given for 3,4-dihydroxybenzoic acid, vanillic acid, isovanillic acid, syringic acid, cinnamic acid, 4-hydroxycinnamic acid, caffeic acid, ferulic acid, isoferulic acid, chlorogenic acid, and rosmarinic acid. For all cinnamic acids and derivatives benzaldehydes were significant oxidation products. With the release of caffeic acid from chlorogenic acid the cleavage of a phenolic glycoside could be demonstrated. Reaction mechanisms are discussed.

  2. Radiation-Induced Prompt Photocurrents in Microelectronics Physics

    CERN Document Server

    Dodd, P E; Buller, D L; Doyle, B L; Vizkelethy, G; Walsh, D S

    2003-01-01

    The effects of photocurrents in nuclear weapons induced by proximal nuclear detonations are well known and remain a serious hostile environment threat for the US stockpile. This report describes the final results of an LDRD study of the physical phenomena underlying prompt photocurrents in microelectronic devices and circuits. The goals of this project were to obtain an improved understanding of these phenomena, and to incorporate improved models of photocurrent effects into simulation codes to assist designers in meeting hostile radiation requirements with minimum build and test cycles. We have also developed a new capability on the ion microbeam accelerator in Sandia's Ion Beam Materials Research Laboratory (the Transient Radiation Microscope, or TRM) to supply ionizing radiation in selected micro-regions of a device. The dose rates achieved in this new facility approach those possible with conventional large-scale dose-rate sources at Sandia such as HERMES III and Saturn. It is now possible to test the phy...

  3. Nonallergenic urushiol derivatives inhibit the oxidation of unilamellar vesicles and of rat plasma induced by various radical generators.

    Science.gov (United States)

    Kim, Jin Young; Cho, Jeong-Yong; Ma, Young Kyu; Lee, Yu Geon; Moon, Jae-Hak

    2014-06-01

    Urushiols consist of an o-dihydroxybenzene (catechol) structure and an alkyl chain of 15 or 17 carbons in the 3-position of a benzene ring and are allergens found in the family Anacardiaceae. We synthesized various veratrole (1,2-dimethoxybenzene)-type and catechol-type urushiol derivatives that contained alkyl chains of various carbon atom lengths, including -H, -C1H3, -C5H11, -C10H21, -C15H31, and -C20H41, and investigated their contact hypersensitivities and antioxidative activities. 3-Decylcatechol and 3-pentadecylcatechol displayed contact hypersensitivity, but the other compounds did not induce an allergic reaction, when the ears of rats were sensitized by treatment with the compounds every day for 20 days. Catechol-type urushiol derivatives (CTUDs) exerted very high radical-scavenging activity on the 1,1-diphenyl-2-picrylhydrazyl radical and inhibited lipid peroxidation in a methyl linoleate solution induced by 2,2'-azobis(2,4-dimethylvaleronitrile) (AMVN). However, veratrole-type urushiol derivatives did not scavenge or inhibit lipid peroxidation. CTUDs also acted as effective inhibitors of lipid peroxidation of the egg yolk phosphatidylcholine large unilamellar vesicle (PC LUV) liposome system induced by various radical generators such as AMVN, 2,2'-azobis(2-amidino-propane) dihydrochloride, and copper ions, although their efficiencies differed slightly. In addition, CTUDs suppressed formation of cholesteryl ester hydroperoxides in rat blood plasma induced with copper ions. CTUDs containing more than five carbon atoms in the alkyl chain showed excellent lipophilicity in a n-octanol/water partition experiment. These compounds also exhibited high affinities to the liposome membrane using the ultrafiltration method of the PC LUV liposome system. Therefore, CTUDs seem to act as efficient antioxidative compounds against membranous lipid peroxidation owing to their localization in the phospholipid bilayer. These results suggest that nonallergenic CTUDs act as

  4. Effects of Arbutin on Radiation-Induced Micronuclei in Mice Bone Marrow Cells and Its Definite Dose Reduction Factor.

    Science.gov (United States)

    Nadi, Saba; Monfared, Ali Shabestani; Mozdarani, Hossein; Mahmodzade, Aziz; Pouramir, Mahdi

    2016-05-01

    Interactions of free radicals from ionizing radiation with DNA can induce DNA damage and lead to mutagenesis and carsinogenesis. With respect to radiation damage to human, it is important to protect humans from side effects induced by ionizing radiation. In the present study, the effects of arbutin were investigated by using the micronucleus test for anti-clastogenic activity, to calculate the ratio of polychromatic erythrocyte to polychromatic erythrocyte plus normochromatic erythrocyte (PCE/PCE+NCE) in order to show cell proliferation activity. Arbutin (50, 100, and 200 mg/kg) was intraperitoneally (ip)administered to NMRI mice two hours before gamma radiation at 2 and 4 gray (Gy). The frequency of micronuclei in 1000 PCEs (MnPCEs) and the ratio of PCE/PCE+NCE were calculated for each sample. Data were statistically evaluated using one-way ANOVA, Tukey HSD test, and t-test. The findings indicated that gamma radiation at 2 and 4 Gy extremely increased the frequencies of MnPCE (Parbutin before irradiation significantly reduced the frequencies of MnPCEs and increased the ratio of PCE/PCE+NCE in mice bone marrow compared to the non-drug-treated irradiated control (Parbutin had no toxicity effect on bone marrow cells. The calculated dose reduction factor (DRF) showed DRF=1.93 for 2Gy and DRF=2.22 for 4 Gy. Our results demonstrated that arbutin gives significant protection to rat bone against the clastogenic and cytotoxic effects of gamma irradiation.

  5. Caffeine Markedly Enhanced Radiation-Induced Bystander Effects

    Science.gov (United States)

    Jiang, Erkang; Wu, Lijun

    2009-04-01

    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).

  6. Radical Radiation Therapy After Lung-Sparing Surgery for Malignant Pleural Mesothelioma: Survival, Pattern of Failure, and Prognostic Factors

    Energy Technology Data Exchange (ETDEWEB)

    Minatel, Emilio [Department of Radiation Oncology, Centro di Riferimento Oncologico of Aviano, Aviano (Italy); Trovo, Marco, E-mail: marcotrovo33@hotmail.com [Department of Radiation Oncology, Centro di Riferimento Oncologico of Aviano, Aviano (Italy); Bearz, Alessandra [Department of Medical Oncology, Centro di Riferimento Oncologico of Aviano, Aviano (Italy); Di Maso, Matteo [Unit of Epidemiology and Biostatistics, Centro di Riferimento Oncologico of Aviano, Aviano (Italy); Baresic, Tania [Department of Nuclear Medicine, Centro di Riferimento Oncologico of Aviano, Aviano (Italy); Drigo, Annalisa; Barresi, Loredana [Department of Medical Physics, Centro di Riferimento Oncologico of Aviano, Aviano (Italy); Furlan, Carlo [Department of Radiation Oncology, Centro di Riferimento Oncologico of Aviano, Aviano (Italy); Del Conte, Alessandro [Department of Medical Oncology, Pordenone General Hospital, Pordenone (Italy); Bruschi, Gioia [Department of Pneumology, Pordenone General Hospital, Pordenone (Italy); Fontana, Paolo [Department of Thoracic Surgery, Mestre General Hospital, Mestre (Italy); Pagan, Vittore [Department of Surgery, Centro di Riferimento Oncologico of Aviano, Aviano (Italy); Franchin, Giovanni [Department of Radiation Oncology, Centro di Riferimento Oncologico of Aviano, Aviano (Italy)

    2015-11-01

    Purpose: To prospectively assess the survival, patterns of failure, and prognostic factors in a large cohort of patients with malignant pleural mesothelioma who had undergone a novel trimodal therapeutic approach, including lung-sparing surgery, chemotherapy, and subsequent treatment with high doses of intensity modulated radiation therapy (IMRT) to the whole hemithorax. Methods and Materials: The analysis was conducted on the data from 69 patients. Of the 69 patients, 35 underwent extended pleurectomy/decortication (P/D), with resection of the entire pleura, along with portions of the pericardium and diaphragm and 34, partial pleurectomy, defined as partial removal of parietal or visceral pleura for diagnostic purposes, leaving gross tumor behind in all cases. All patients received cisplatin/pemetrexed chemotherapy. Postoperative IMRT was delivered to the entire hemithorax, excluding the intact lung. The IMRT dose was 50 Gy in 25 fractions. Any fluorodeoxyglucose-avid areas or regions of particular concern for residual disease were given a simultaneous boost to 60 Gy. Results: The median follow-up duration was 19 months. No difference was seen in overall survival and locoregional control between the extended P/D group and the partial pleurectomy group. The 2-year overall survival was 65% and 58% in the extended P/D and partial pleurectomy groups, respectively (P=.94). Locoregional control at 2 years was 65% and 64% in the extended P/D and partial pleurectomy groups, respectively (P=.75). The predominant pattern of failure was distant: 19 patients (27.5%) developed distant metastases as the first site of relapse. Gross residual disease after surgery was significantly associated with overall survival (hazard ratio 3.45). One fatal pneumonitis was reported; 14 cases (20%) of grade 2 to 3 pneumonitis were documented. Conclusions: Radical IMRT after lung-sparing surgery and chemotherapy for malignant pleural mesothelioma leads to promising survival results and

  7. Radical Radiation Therapy After Lung-Sparing Surgery for Malignant Pleural Mesothelioma: Survival, Pattern of Failure, and Prognostic Factors.

    Science.gov (United States)

    Minatel, Emilio; Trovo, Marco; Bearz, Alessandra; Di Maso, Matteo; Baresic, Tania; Drigo, Annalisa; Barresi, Loredana; Furlan, Carlo; Del Conte, Alessandro; Bruschi, Gioia; Fontana, Paolo; Pagan, Vittore; Franchin, Giovanni

    2015-11-01

    To prospectively assess the survival, patterns of failure, and prognostic factors in a large cohort of patients with malignant pleural mesothelioma who had undergone a novel trimodal therapeutic approach, including lung-sparing surgery, chemotherapy, and subsequent treatment with high doses of intensity modulated radiation therapy (IMRT) to the whole hemithorax. The analysis was conducted on the data from 69 patients. Of the 69 patients, 35 underwent extended pleurectomy/decortication (P/D), with resection of the entire pleura, along with portions of the pericardium and diaphragm and 34, partial pleurectomy, defined as partial removal of parietal or visceral pleura for diagnostic purposes, leaving gross tumor behind in all cases. All patients received cisplatin/pemetrexed chemotherapy. Postoperative IMRT was delivered to the entire hemithorax, excluding the intact lung. The IMRT dose was 50 Gy in 25 fractions. Any fluorodeoxyglucose-avid areas or regions of particular concern for residual disease were given a simultaneous boost to 60 Gy. The median follow-up duration was 19 months. No difference was seen in overall survival and locoregional control between the extended P/D group and the partial pleurectomy group. The 2-year overall survival was 65% and 58% in the extended P/D and partial pleurectomy groups, respectively (P=.94). Locoregional control at 2 years was 65% and 64% in the extended P/D and partial pleurectomy groups, respectively (P=.75). The predominant pattern of failure was distant: 19 patients (27.5%) developed distant metastases as the first site of relapse. Gross residual disease after surgery was significantly associated with overall survival (hazard ratio 3.45). One fatal pneumonitis was reported; 14 cases (20%) of grade 2 to 3 pneumonitis were documented. Radical IMRT after lung-sparing surgery and chemotherapy for malignant pleural mesothelioma leads to promising survival results and acceptable toxicity rates. The similarity of survival between

  8. Radiation-Induced Immune Modulation in Prostate Cancer

    Science.gov (United States)

    2007-01-01

    or the expression of immunosuppressive cytokines and related molecules by DCs. To overcome this radiation-induced immunosuppression, we plan to...effects on the tumor microenvironment, such as up- regulating the expression of inflammatory mediators (e.g. COX2 and PGE2), heat shock proteins ...Economou. 1997. Genetic immunization for the melanoma antigen MART- 1/ Melan -A using recombinant adenovirus-transduced murine dendritic cells. Cancer Res

  9. Radiation-Induced Cardiovascular Disease: A Clinical Perspective

    Directory of Open Access Journals (Sweden)

    Syed Wamique Yusuf

    2017-10-01

    Full Text Available Cancer survival has improved dramatically, and this has led to the manifestation of late side effects of multimodality therapy. Radiation (RT to the thoracic malignancies results in unintentional irradiation of the cardiac chambers. RT-induced microvascular ischemia leads to disruption of capillary endothelial framework, and injury to differentiated myocytes results in deposition of collagen and fibrosis. Coexistence of risk factors of metabolic syndrome and preexisting atherosclerosis in addition to RT exposure results in accelerated occurrence of major coronary events. Hence, it becomes pertinent to understand the underlying pathophysiology and clinical manifestations of RT-induced cardiovascular disease to devise optimal preventive and surveillance strategies.

  10. Hyperbaric oxygen therapy for radiation-induced hemorrhagic cystitis

    Energy Technology Data Exchange (ETDEWEB)

    Miyazato, Tomonori; Yusa, Toshiko; Onaga, Tomohiro; Sugaya, Kimio; Koyama, Yuzo; Hatano, Tadashi; Ogawa, Yoshihide [Ryukyus Univ., Nishihara, Okinawa (Japan). Faculty of Medicine

    1998-05-01

    Radiation therapy has widely been used for cancers in the pelvis. Radiation cystitis, one of the late complications, presents often as hemorrhagic cystitis, which is refractory to the conventional therapy and may threaten the patient`s life. We used hyperbaric oxygen therapy on patients with radiation cystitis to test its potential benefit. Ten patients aged from 46 to 81 years with a mean of 62 years underwent one or more courses of hyperbaric oxygen therapy according to their symptoms, consisting of 20 sessions (3 to 5 sessions a week) at the Department of Hyperbaric Medicine, the University of the Ryukyus Hospital in the 9-year period from 1985 to 1994. They included 8 patients having a history of cervical cancer, one with external genital cancer and one with vaginal cancer. During the 75 min hyperbaric oxygen therapy patients received 100% oxygen at 2 absolute atmosphere pressure in the Multiplace Hyperbaric Chamber. Hematuria subsided and subjective symptoms including urinary frequency improved in seven patients. Cystoscopic findings including mucosal edema, redness, and capillary dilation were partially improved. The procedure subjectively and objectively palliated the 10 patients in a favorable manner. To date we have not armed any active procedure to control radiation-induced refractory hemorrhagic cystitis in terms of efficacy, invasiveness, and adverse effects. Therefore, in consideration of our clinical results, hyperbaric oxygen therapy appears to be useful for radiation cystitis. (author)

  11. Gas-Phase Intercluster Thiyl-Radical Induced C-H Bond Homolysis Selectively Forms Sugar C2-Radical Cations of Methyl D-Glucopyranoside: Isotopic Labeling Studies and Cleavage Reactions

    Science.gov (United States)

    Osburn, Sandra; Speciale, Gaetano; Williams, Spencer J.; O'Hair, Richard A. J.

    2017-07-01

    A suite of isotopologues of methyl D-glucopyranosides is used in conjunction with multistage mass spectrometry experiments to determine the radical site and cleavage reactions of sugar radical cations formed via a recently developed `bio-inspired' method. In the first stage of CID (MS2), collision-induced dissociation (CID) of a protonated noncovalent complex between the sugar and S-nitrosocysteamine, [H3NCH2CH2SNO + M]+, unleashes a thiyl radical via bond homolysis to give the noncovalent radical cation, [H3NCH2CH2S• + M]+. CID (MS3) of this radical cation complex results in dissociation of the noncovalent complex to generate the sugar radical cation. Replacement of all exchangeable OH and NH protons with deuterons reveals that the sugar radical cation is formed in a process involving abstraction of a hydrogen atom from a C-H bond of the sugar coupled with proton transfer to the sugar, to form [M - H• + D+]. Investigation of this process using individual C-D labeled sugars reveals that the main site of H/D abstraction is the C2 position, since only the C2-deuterium labeled sugar yields a dominant [M - D• + H+] product ion. The fragmentation reactions of the distonic sugar radical cation, [M - H•+ H+], were studied by another stage of CID (MS4). 13C-labeling studies revealed that a series of three related fragment ions each contain the C1-C3 atoms; these arise from cross-ring cleavage reactions of the sugar.

  12. 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

  13. Radiation induced esophageal adenocarcinoma in a woman previously treated for breast cancer and renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Raissouni Soundouss

    2012-08-01

    Full Text Available Abstract Background Secondary radiation-induced cancers are rare but well-documented as long-term side effects of radiation in large populations of breast cancer survivors. Multiple neoplasms are rare. We report a case of esophageal adenocarcinoma in a patient treated previously for breast cancer and clear cell carcinoma of the kidney. Case presentation A 56 year-old non smoking woman, with no alcohol intake and no familial history of cancer; followed in the National Institute of Oncology of Rabat Morocco since 1999 for breast carcinoma, presented on consultation on January 2011 with dysphagia. Breast cancer was treated with modified radical mastectomy, 6 courses of chemotherapy based on CMF regimen and radiotherapy to breast, inner mammary chain and to pelvis as castration. Less than a year later, a renal right mass was discovered incidentally. Enlarged nephrectomy realized and showed renal cell carcinoma. A local and metastatic breast cancer recurrence occurred in 2007. Patient had 2 lines of chemotherapy and 2 lines of hormonotherapy with Letrozole and Tamoxifen assuring a stable disease. On January 2011, the patient presented dysphagia. Oesogastric endoscopy showed middle esophagus stenosing mass. Biopsy revealed adenocarcinoma. No evidence of metastasis was noticed on computed tomography and breast disease was controlled. Palliative brachytherapy to esophagus was delivered. Patient presented dysphagia due to progressive disease 4 months later. Jejunostomy was proposed but the patient refused any treatment. She died on July 2011. Conclusion We present here a multiple neoplasm in a patient with no known family history of cancers. Esophageal carcinoma is most likely induced by radiation. However the presence of a third malignancy suggests the presence of genetic disorders.

  14. Influence of corticosteroids and vitamin E deficiency on onset of radiation-induced cataract

    Science.gov (United States)

    Junk, A. K.; Worgul, B. W.

    Cataracts characteristic of those arising from radiation exposure have been reported among the astronaut and cosmonaut corps. This being the case it is critical to appreciate how radiogenic cataracts relate to those arising from other exogenous causes such as therapeutics, which may, one day, have to be administered on an extended mission. Because they produce precisely the same clinical picture, corticosteroids are examples of a class of drugs that potentially can exacerbate damage to the lens from radiation. On the other hand, Vitamin E, a free radical scavenger, has been shown to ameliorate oxidative damage as caused by ionizing radiation and evidence is accumulating that it may constitute protection from radiogenic damage. An experimental study was conducted to understand if corticosteroids with, and in the absence of Vitamin E deficiency modulate the onset of cataract induced by ionizing radiation. The right eyes of seventy-two 28-day-old Brown-Norway rats were irradiated with 6 Gy of 240 kV X-rays, the shielded left eyes served as controls. Half of the animals were maintained on a Vitamin E free diet after irradiation, the others were kept on standard chow. Fifty per cent of the animals in each nutritional group received dexamethasone. The initial daily dose of 10 mg/kg body weight injected subcutaneously was reduced to 0.5 mg/kg over the course of six months. Cataract onset and development were followed by weekly slit-lamp exam. After six month the lenses were harvested for microscopic analyses. Irradiated eyes in all treatment subgroups showed early cataract onset [5 wks vs. 11 wks in controls ( p Corticosteroids accounted for accelerated cataract development in both irradiated ( p corticosteroids accelerate cataract formation. The surprising protective influence of Vitamin E deficiency may be the result of a stathmokinetic effect on mitosis - a possibility that is supported by lens epithelial histopathology in the regions of cell mitosis and

  15. Influence of Corticosteroids and Vitamin E Deficiency on Onset and Cytopathology of Radiation-Induced Cataract

    Science.gov (United States)

    Junk, A. K.; Worgul, B. V.

    Cataracts characteristic of those arising from radiation exposure have been reported among the astronaut and cosmonaut corps. This being the case it is critical to appreciate how radiogenic cataracts relate to those arising from other exogenous causes such as therapeutics, which may, one day, have to be administered on an extended mission. Because they produce precisely the same clinical picture, corticosteroids are examples of a class of drugs that potentially can exacerbate damage to the lens from radiation. On the other hand, Vitamin E, a free radical scavenger, has been shown to ameliorate oxidative damage as caused by ionizing radiation and evidence is accumulating that it may constitute protection from radiogenic damage. An experimental study was conducted to understand if corticosteroids with and in the absence of Vitamin E deficiency modulate the onset of cataract induced by ionizing radiation. The right eyes of 72 28-day-old Brown-Norway rats were irradiated with 6 Gy of 240 kV X-rays, the shielded left eyes served as controls. Half of the animals were maintained on a Vitamin E free diet after irradiation, the others were kept on regular chow. In each nutritional group 18 rats additionally received dexamethasone. The initial daily dose of 10 mg/kg body weight injected subcutaneously was reduced to 0.5 mg/kg over the course of 6 months. Cataract onset and development were followed by weekly slit-lamp exam. After 6 month the lenses were harvested for microscopic analyses. Irradiated eyes in all treatment subgroups showed early cataract onset [5 wks versus 11 wks in controls (pCorticosteroids accounted for accelerated cataract development in both irradiated (pcorticosteroids accelerate cataract formation. The surprising protective influence of Vitamin E deficiency may be the result of a stathmokinetic effect on mitosis - a possibility that is supported by lens epithelial histopathology in the regions of cell mitosis and differentiation.

  16. Ultraviolet radiation-induced murine tumors produced in the absence of ultraviolet radiation-induced systemic tumor immunosuppression.

    Science.gov (United States)

    Menzies, S W; Greenoak, G E; Reeve, V E; Gallagher, C H

    1991-06-01

    Using micro-UV-irradiation versus whole-dorsal irradiation for inducing cutaneous carcinomas in Skh:HRI mice and an assay for UV radiation (UVR)-induced systemic tumor immunosuppression, the dependence upon systemic immunosuppression for the growth of UVR-induced carcinomas was examined. Squamous cell carcinomas were produced by repeated microirradiation of 0.8-cm2 middorsal skin with xenon are solar-simulated UVR. These tumors were excised from tumor-bearing animals who 7 days later were inoculated ventrally with a cloned UVR-induced squamous cell carcinoma cell line, the T51/6. This cell line only grows in UVR-induced immunosuppressed Skh:HRI mice. In two separate experiments T51/6 inocula failed to grow significantly in the previously tumor-bearing animals (1 of 13) and in unirradiated mice (0 of 19), whereas it grew in 100% (15 of 15) of animals given a whole-dorsal subcarcinogenic UVR dose from a filtered fluorescent tube solar simulator. No sinecomitant immune response to the T51/6 was found in previously UVR-induced tumor-bearing animals. In contrast to whole-dorsal UVR-induced tumors, microirradiation-induced squamous cell carcinomas, whose original growth environment lacked UVR-induced systemic tumor immunosuppression, did not grow preferentially in mice given an immunosuppressive dose of UVR. However both the whole-dorsal and microirradiation-induced tumors were shown to be poorly antigenic, since they lacked preferential growth in athymic nude mice. These observations provide evidence that UVR-induced systemic tumor immunosuppression is not necessary for the production of UVR-induced tumors. However, it does cause a positive selection pressure during tumor formation, independent of the carcinogenic effect of UVR, which affects the transplantation biology of a tumor.

  17. Radiation-induced adaptive response in fish cell lines.

    Science.gov (United States)

    Ryan, Lorna A; Seymour, Colin B; O'Neill-Mehlenbacher, Alicia; Mothersill, Carmel E

    2008-04-01

    There is considerable interest at present in low-dose radiation effects in non-human species. In this study gamma radiation-induced adaptive response, a low-dose radiation effect, was examined in three fish cell lines, (CHSE-214 (Chinook salmon), RTG-2 (rainbow trout) and ZEB-2J (zebrafish)). Cell survival after exposure to direct radiation with or without a 0.1 Gy priming dose, was determined using the colony forming assay for each cell line. Additionally, the occurrence of a bystander effect was examined by measuring the effect of irradiated cell culture medium from the fish cell lines on unexposed reporter cells. A non-linear dose response was observed for all cell lines. ZEB-2J cells were very sensitive to low doses and a hyper-radiosensitive (HRS) response was observed for doses fish cell lines tested. Rather, it was found that pre-exposure of these cells to 0.1 Gy radiation sensitized the cells to subsequent high doses. In CHSE-214 cells, increased sensitivity to subsequent high doses of radiation was observed when the priming and challenge doses were separated by 4 h; however, this sensitizing effect was no longer present when the interval between doses was greater than 8 h. Additionally, a "protective" bystander response was observed in these cell lines; exposure to irradiated medium from fish cells caused increased cloning efficiency in unirradiated reporter cells. The data confirm previous conclusions for mammalian cells that the adaptive response and bystander effect are inversely correlated and contrary to expectations probably have different underlying mechanisms.

  18. Superoxide radical induces sclerotial differentiation in filamentous phytopathogenic fungi: a superoxide dismutase mimetics study.

    Science.gov (United States)

    Papapostolou, Ioannis; Georgiou, Christos D

    2010-03-01

    This study shows that the superoxide radical (O(2) *( -)), a direct indicator of oxidative stress, is involved in the differentiation of the phytopathogenic filamentous fungi Rhizoctonia solani, Sclerotinia sclerotiorum, Sclerotium rolfsii and Sclerotinia minor, shown by using superoxide dismutase (SOD) mimetics to decrease their sclerotial differentiation. The production rate of O(2) *(-) and SOD levels in these fungi, as expected, were significantly lowered by the SOD mimetics, with concomitant decrease of the indirect indicator of oxidative stress, lipid peroxidation.

  19. Modulation of Ionizing Radiation Induced Oxidative Imbalance by Semi-Fractionated Extract of Piper betle: An In Vitro and In Vivo Assessment

    Directory of Open Access Journals (Sweden)

    Savita Verma

    2010-01-01

    Full Text Available The study was planned to evaluate modulatory effect of aqueous extract of Piper betle leaf (PBL on ionizing radiation mediated oxidative stress leading to normal tissues damage during radiotherapy and other radiation exposures. The total polyphenols and flavonoids known as free radical scavenger (chelators were measured in the extract. To ascertain antioxidant potential of PBL extract, we studied free radical scavenging, metal chelation, reducing power, lipid peroxidation inhibition and ferric reducing antioxidant properties (FRAP using in vitro assays. Mice were exposed to varied radiation doses administered with the same extract prior to irradiation to confirm its oxidative stress minimizing efficacy by evaluating ferric reducing ability of plasma, reduced glutathione, lipid peroxidation and micro-nuclei frequency. PBL extract was effective in scavenging DPPH (up to 92% at 100 µg/ml and superoxide radicals (up to 95% at 80 µg/ml, chelated metal ions (up to 83% at 50 µg/ml and inhibited lipid peroxidation (up to 45.65% at 500 µg/ml in a dose dependant manner using in vitro model. Oral administration of PBL extract (225 mg/kg body weight 1 hr before irradiation in mice significantly enhanced (p < 0.01 radiation abated antioxidant potential of plasma and GSH level in all the observed organs. The treatment with extract effectively lowered the radiation induced lipid peroxidation at 24 hrs in all the selected organs with maximum inhibition in thymus (p < 0.01. After 48 hrs, lipid peroxidation was maximally inhibited in the group treated with the extract. Frequency of radiation induced micronucleated cells declined significantly (34.78%, p < 0.01 at 24 hrs post-irradiation interval by PBL extract administration. The results suggest that PBL extract has high antioxidant potential and relatively non-toxic and thus could be assertively used to mitigate radiotherapy inflicted normal tissues damage and also injuries caused by moderate doses of

  20. EPR characteristics of free radicals in DOPA-melanin-moxifloxacin complexes at ambient level of UVA radiation

    Science.gov (United States)

    Beberok, Artur; Zdybel, Magdalena; Pilawa, Barbara; Buszman, Ewa; Wrześniok, Dorota

    2014-01-01

    EPR studies pointed out that o-semiquinone free radicals with g-values 2.0038-2.0040 take part in moxifloxacin-melanin complex formation. The process contributed to increase in free radicals concentration in nonirradiated complexes. This effect was observed for the complexes with 1 × 10-4 M, 1 × 10-3 M and 4 × 10-3 M drug concentrations. UV irradiation contributed to decrease in free radicals concentration in DOPA-melanin complexes with moxifloxacin, besides the complexes with the drug concentration of 1 × 10-4 M. The strongest decrease was observed for DOPA-melanin-moxifloxacin complexes with the drug concentration of 1 × 10-3 M. Homogeneous broadening of EPR lines, strong dipolar interactions and slow spin-lattice relaxation processes characterized all the tested melanin samples.

  1. Enhanced antioxidant effect of caffeic acid phenethyl ester and Trolox in combination against radiation induced-oxidative stress.

    Science.gov (United States)

    Bai, Hua; Liu, Rui; Chen, Hong-Li; Zhang, Wei; Wang, Xin; Zhang, Xiao-Di; Li, Wen-Li; Hai, Chun-Xu

    2014-01-25

    Combinations of antioxidants are believed to be more effective than single antioxidant because when antioxidants are combined they support each other synergistically to create a magnified effect. Discovering the enhancer effects or synergies between bioactive components is valuable for resisting oxidative stress and improving health benefits. The aim of this study was to investigate a possible cooperation of natural antioxidant caffeic acid phenethyl ester (CAPE) with synthetic antioxidant Trolox in the model systems of chemical generation of free radicals, lipid peroxidation of microsomes and radiation-induced oxidative injury in L929 cells. Based on the intermolecular interaction between CAPE and Trolox, the present study shows a synergistic effect of CAPE and Trolox in combination on elimination of three different free radicals and inhibition of lipid peroxidation initiated by three different systems. CAPE and Trolox added simultaneously to the L929 cells exerted an enhanced preventive effect on the oxidative injury induced by radiation through decreasing ROS generation, protecting plasma membrane and increasing the ratios of reduced glutathione/oxidized glutathione and the expression of key antioxidant enzymes mediated by nuclear factor erythroid 2 p45-related factor 2 (Nrf2). Our results showed for the first time that administration of CAPE and Trolox in combination may exert synergistic antioxidant effects, and further indicate that CAPE and Trolox combination functions mainly through scavenging ROS directly, inhibiting lipid peroxidation and promoting redox cycle of GSH mediated by Nrf2-regulated glutathione peroxidase and glutathione reductase expression. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  2. Phenolic compounds isolated from Pilea microphylla prevent radiation-induced cellular DNA damage

    Directory of Open Access Journals (Sweden)

    Punit Bansal

    2011-12-01

    Full Text Available Six phenolic compounds namely, quercetin-3-O-rutinoside (1, 3-O-caffeoylquinic acid (2, luteolin-7-O-glucoside (3, apigenin-7-O-rutinoside (4, apigenin-7-O-β-d-glucopyranoside (5 and quercetin (6 were isolated from the whole plant of Pilea microphylla using conventional open-silica gel column chromatography and preparative HPLC. Further, these compounds were characterized by 1D, 2D NMR techniques and high-resolution LC–MS. Compounds 1–3 and 6 exhibited significant antioxidant potential in scavenging free radicals such as DPPH, ABTS and SOD with IC50 of 3.3–20.4 μmol/L. The same compounds also prevented lipid peroxidation with IC50 of 10.4–32.2 μmol/L. The compounds also significantly prevented the Fenton reagent-induced calf thymus DNA damage. Pre-treatment with compounds 1–3 and 6 in V79 cells attenuated radiation-induced formation of reactive oxygen species, lipid peroxidation, cytotoxicity and DNA damage, correlating the antioxidant activity of polyphenols with their radioprotective effects. Compounds 1, 3 and 6 significantly inhibited lipid peroxidation, presumably due to 3′,4′-catechol ortho-dihydroxy moiety in the B-ring, which has a strong affinity for phospholipid membranes. Oxidation of flavonoids, with catechol structure on B-ring, yields a fairly stable ortho-semiquinone radical by facilitating electron delocalization, which is involved in antioxidant mechanism. Hence, the flavonoid structure, number and location of hydroxyl groups together determine the antioxidant and radioprotection mechanism.

  3. Modifications induced by swift heavy ions on poly(hydroxybutyrate-hydroxyvalerate) (PHB/HV) and poly({epsilon}-caprolactone) (PCL). Part 2. Radicals characterization

    Energy Technology Data Exchange (ETDEWEB)

    Rouxhet, L.; Mestdagh, M.; Legras, R. E-mail: legras@poly.ucl.ac.be

    2000-12-01

    Modifications induced by different energetic heavy ions ({sub 40}Ar{sup 9+}, {sub 80}Kr{sup 15+}, {sub 129}Xe{sup 24+}, {sub 208}Pb{sup 53+} and {sub 208}Pb{sup 56+}) on poly({epsilon}-caprolactone) (PCL) and poly(hydroxybutyrate-hydroxyvalerate) (PHB/HV) have been investigated by electron spin resonance (ESR). Indeed, film irradiation by heavy ions leads to, among other phenomena, the formation of radicals in the ion tracks. Thanks to ESR, it is possible to detect these radicals and to identify them or at least to characterize them by following the evolution of the radical signal as a function of parameters, like temperature, or the kinetic of disappearance of the radical species at ambient temperature in vacuum or ambient atmosphere. This study confirmed the generation of radicals by the irradiation of PHB/HV samples with energetic heavy ions reported in the literature. The study on PCL was not pursued after a few preliminary studies, revealing the presence of an ESR signal in the non-irradiated sample. Electronic stopping power has a major influence on radical decrease at ambient temperature. The ion used for the irradiation did not modify very much the radical signal and the evolution of the radicalar signal intensity with temperature. Different reasoning and experiments revealed that the glass transition temperature is a key temperature above which irreversible recombinations of the most stable radicals take place. A simulation study indicated that the most stable radical produced was probably a tertiary radical formed by the stabilization of the secondary radical resulting from the abstraction of a highly mobile hydrogen adjacent to the carbonyl.

  4. Cigarette smoke-induced reduction in binding of the salivary translocator protein is not mediated by free radicals.

    Science.gov (United States)

    Nagler, R; Savulescu, D; Gavish, M

    2016-02-01

    Oral cancer is the most common malignancy of the head and neck and its main inducer is exposure to cigarette smoke (CS) in the presence of saliva. It is commonly accepted that CS contributes to the pathogenesis of oral cancer via reactive free radicals and volatile aldehydes. The 18 kDa translocator protein (TSPO) is an intracellular receptor involved in proliferation and apoptosis, and has been linked to various types of cancer. The presence of TSPO in human saliva has been linked to oral cancer, and its binding affinity to its ligand is reduced following exposure to CS. In the present study we wished to further investigate the mechanism behind the CS-induced reduction of TSPO binding by exploring the possible mediatory role of reactive oxygen species (ROS) and volatile aldehydes in this process. We first analyzed TSPO binding in control saliva and in saliva exposed to CS in the presence and absence of various antioxidants. These experiments found that TSPO binding ability was not reversed by any of the antioxidants added, suggesting that CS exerts its effect on TSPO via mechanisms that do not involve volatile aldehydes and free radicals tested. Next, we analyzed TSPO binding in saliva following addition of exogenous ROS in the form of H2O2. These experiments found that TSPO binding was enhanced due to the treatment, once again showing that the CS-induced TSPO binding reduction is not mediated by this common form of ROS. However, the previously reported CS-induced reduction in salivary TSPO binding together with the role of TSPO in cells and its link to cancer strongly suggest that TSPO has a critical role in the pathogenesis of CS-induced oral cancer. The importance of further elucidating the mechanisms behind it should be emphasized. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  5. Pedicle omental graft created by laparoscopic surgery for filling a radiation-induced ulcer in a woman with breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ida, Katsuya [Kosai General Hospital, Shizuoka (Japan)

    2002-06-01

    In patients with advanced or recurrent breast cancer, it is difficult to reconstruct chest wall ulcers due to postoperative irradiation, which is often infected. We present a laparoscopic technique for creating and mobilizing an omental flap. A 63-year-old woman diagnosed with parasternal lymph node metastases from left breast cancer 11 months after standard radical mastectomy underwent lymph node resection with radiation therapy. She developed ulceration of the irradiated chest wall 3 years and 10 months later. An omental flap obtained by laparoscopy was used to fill the space after the radiation-induced ulcer was resected and covered with a free skin graft. The skin graft adapted to the omentum. This laparoscopic procedure is more cosmetrically acceptable and less invasive than laparotomy in obtaining the omentum while yielding equivalent results in chest wall reconstruction. (author)

  6. Pharmacological Protection From Radiation {+-} Cisplatin-Induced Oral Mucositis

    Energy Technology Data Exchange (ETDEWEB)

    Cotrim, Ana P. [Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States); Yoshikawa, Masanobu [Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States); Department of Clinical Pharmacology, Tokai University School of Medicine, Kanagawa (Japan); Sunshine, Abraham N.; Zheng Changyu [Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States); Sowers, Anastasia L.; Thetford, Angela D.; Cook, John A.; Mitchell, James B. [Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); Baum, Bruce J., E-mail: bbaum@dir.nidcr.nih.gov [Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States)

    2012-07-15

    Purpose: To evaluate if two pharmacological agents, Tempol and D-methionine (D-met), are able to prevent oral mucositis in mice after exposure to ionizing radiation {+-} cisplatin. Methods and Materials: Female C3H mice, {approx}8 weeks old, were irradiated with five fractionated doses {+-} cisplatin to induce oral mucositis (lingual ulcers). Just before irradiation and chemotherapy, mice were treated, either alone or in combination, with different doses of Tempol (by intraperitoneal [ip] injection or topically, as an oral gel) and D-met (by gavage). Thereafter, mice were sacrificed and tongues were harvested and stained with a solution of Toluidine Blue. Ulcer size and tongue epithelial thickness were measured. Results: Significant lingual ulcers resulted from 5 Multiplication-Sign 8 Gy radiation fractions, which were enhanced with cisplatin treatment. D-met provided stereospecific partial protection from lingual ulceration after radiation. Tempol, via both routes of administration, provided nearly complete protection from lingual ulceration. D-met plus a suboptimal ip dose of Tempol also provided complete protection. Conclusions: Two fairly simple pharmacological treatments were able to markedly reduce chemoradiation-induced oral mucositis in mice. This proof of concept study suggests that Tempol, alone or in combination with D-met, may be a useful and convenient way to prevent the severe oral mucositis that results from head-and-neck cancer therapy.

  7. Radiation-induced volatile hydrocarbon production in platelets. Scientific report

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-01-01

    Thrombocytopenia plays an important role in the development of the post-irradiation hemorrhagic syndrome. Although destruction of platelet precursors in bone marrow is a major effect of high-dose radiation exposure, the effects of radiation on preformed platelets are unclear. The latter is also of concern with respect to blood-banking practices since platelets are often irradiated at doses in the range of 20-50 Gy before transfusions to prevent graft-versus-host disease. With increasing emphasis on allogenic and autologous bone-marrow transplantation, transfusions of irradiated platelets are likely to rise. 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.

  8. Gamma radiation induces hydrogen absorption by copper in water.

    Science.gov (United States)

    Lousada, Cláudio M; Soroka, Inna L; Yagodzinskyy, Yuriy; Tarakina, Nadezda V; Todoshchenko, Olga; Hänninen, Hannu; Korzhavyi, Pavel A; Jonsson, Mats

    2016-04-18

    One of the most intricate issues of nuclear power is the long-term safety of repositories for radioactive waste. These repositories can have an impact on future generations for a period of time orders of magnitude longer than any known civilization. Several countries have considered copper as an outer corrosion barrier for canisters containing spent nuclear fuel. Among the many processes that must be considered in the safety assessments, radiation induced processes constitute a key-component. Here we show that copper metal immersed in water uptakes considerable amounts of hydrogen when exposed to γ-radiation. Additionally we show that the amount of hydrogen absorbed by copper depends on the total dose of radiation. At a dose of 69 kGy the uptake of hydrogen by metallic copper is 7 orders of magnitude higher than when the absorption is driven by H2(g) at a pressure of 1 atm in a non-irradiated dry system. Moreover, irradiation of copper in water causes corrosion of the metal and the formation of a variety of surface cavities, nanoparticle deposits, and islands of needle-shaped crystals. Hence, radiation enhanced uptake of hydrogen by spent nuclear fuel encapsulating materials should be taken into account in the safety assessments of nuclear waste repositories.

  9. Ionizing radiation-induced copolymerization of 2-ethylhexyl acrylate and acrylic acid and ionomer formation

    Science.gov (United States)

    Weaver, Alia

    The ionizing radiation-induced polymerization of acrylate esters is a technique employed for the curing of such materials for a variety of adhesive, coating, ink, and lithographic applications. The work presented in this dissertation involves the synthesis of a copolymer composed of 2-ethylhexyl acrylate (2-EHA) and acrylic acid (AA) using pulsed electron beam and gamma irradiation. The structure and synthesis kinetics of this copolymer were investigated by 1H nuclear magnetic resonance (NMR), electron pulse radiolysis with kinetic spectroscopic detection (PR-KSD), and Fourier transform infrared spectroscopy (FTIR). The effects of total dose, dose rate, and acrylic acid content on the polymerization reaction were studied. The conversion of 2-EHA monomer into polymer at a given total dose was found to be enhanced at lower dose rates and higher concentrations of acrylic acid. The pulse radiolysis investigation of the polymerization of 2-EHA and AA was performed through studies of four different types of systems: (i) neat 2-EHA, (ii) 2-EHA/methanol (MeOH) solutions, (iii) mixtures of 2-EHA and AA, and (iv) 2-EHA/AA/MeOH solutions. The build-up of carbon-centered neutral 2-EHA free radicals in neat 2-EHA was found to obey a second order rate law with a rate coefficient of ((7 +/- 3) x 108)epsilon EHA·, whereas in 2-EHA/AA mixtures it was found to obey a pseudo-first order rate law with a rate coefficient of (1.5 +/- 0.3) x 10 10 mol-1 dm3 s-1. This phenomenon is suggested to originate in the increased H+ ion concentration in the presence of acrylic acid, which leads to a faster neutralization step of 2-EHA radical anions as they are transformed into neutral free radicals during the initiation step of the reaction. An investigation of the formation of ion-containing copolymers (known as ionomers) was performed using the radiation-synthesized poly(2-EHA-co-AA) and iron cations. Verification of successful incorporation of iron into the copolymer was identified by an

  10. Five year biochemical recurrence free survival for intermediate risk prostate cancer after radical prostatectomy, external beam radiation therapy or permanent seed implantation.

    Science.gov (United States)

    Vassil, Andrew D; Murphy, Erin S; Reddy, Chandana A; Angermeier, Kenneth W; Altman, Andrew; Chehade, Nabil; Ulchaker, James; Klein, Eric A; Ciezki, Jay P

    2010-11-01

    To compare biochemical recurrence-free survival (bRFS) for patients with intermediate-risk prostate cancer treated by retropubic radical prostatectomy (RRP), laparoscopic radical prostatectomy (LRP), external beam radiation therapy (RT), or permanent seed implantation (PI). Patients treated for intermediate-risk prostate cancer per National Comprehensive Cancer Network guidelines from 1996 to 2005 were studied. Variables potentially affecting bRFS were examined using univariate and multivariate Cox regression analysis. Five-year bRFS rates were calculated by actuarial methods; bRFS was calculated using Kaplan-Meier analysis. Nadir +2 definition of biochemical failure was used for RT and PI patients; a PSA ≥ 0.4 ng/mL was used for radical prostatectomy (RP) patients. Time to initiation of salvage therapy was compared for each treatment group using the Kruskal-Wallis test. Nine-hundred seventy-nine patients were analyzed with a median follow-up of 65 months. Five years bRFS rate was 82.8% for all patients (89.5% PI, 85.7% RT, 79.9% RRP, and 60.2% LRP). Patients treated by LRP had significantly worse bRFS than RT (P PI (P PSA tests per year (P PI, 47.8 RT; P PI, RT, or RRP appear to have improved 5-year bRFS and delayed salvage therapy compared with LRP. Copyright © 2010 Elsevier Inc. All rights reserved.

  11. Radiation damage to human erythrocytes. Relative contribution of hydroxyl and chloride radicals in N{sub 2}O-saturated buffers

    Energy Technology Data Exchange (ETDEWEB)

    Krokosz, Anita [Department of Molecular Biophysics, University of Lodz, Banacha 12/16, 90 237 Lodz (Poland)], E-mail: krokosz@biol.uni.lodz.pl; Komorowska, Magdalena A.; Szweda-Lewandowska, Zofia [Department of Molecular Biophysics, University of Lodz, Banacha 12/16, 90 237 Lodz (Poland)

    2008-06-15

    The erythrocyte suspensions in Na-phosphate buffered isotonic NaCl solution (PBS) or Na-phosphate isotonic buffer (PB) (hematocrit 1%) were irradiated with the dose of 400 Gy under N{sub 2}O. Erythrocytes were incubated in the medium in which the cells were irradiated or in fresh PBS. The level of damage to cells was estimated on the basis of the course of post-radiation hemolysis and hemoglobin (Hb) oxidation. The medium in which the cells were irradiated and incubated influenced the course of the post-radiation hemolysis and Hb oxidation as well as some other parameters. We discussed the contribution of hydroxyl and chloride radicals in the initiation of erythrocyte damage and oxygen modification of these processes.

  12. Radiation-induced cerebral meningioma: a recognizable entity

    Energy Technology Data Exchange (ETDEWEB)

    Rubinstein, A.B.; Shalit, M.N.; Cohen, M.L.; Zandbank, U.; Reichenthal, E.

    1984-11-01

    The authors retrospectively analyzed the clinical and histopathological findings in 201 patients with intracranial meningiomas operated on in the period 1978 to 1982. Forty-three of the patients (21.4%) had at some previous time received radiation treatment to their scalp, the majority for tinea capitis. The findings in these 43 irradiated patients were compared with those in the 158 non-irradiated patients. Several distinctive clinical and histological features were identified in the irradiated group, which suggest that radiation-induced meningiomas can be defined as a separate nosological subgroup. The use of irradiation in large numbers of children with tinea capitis in the era prior to the availability of griseofulvin may be responsible for a significantly increased incidence of intracranial meningiomas.

  13. Treatment of radiation- and chemotherapy-induced stomatitis

    Energy Technology Data Exchange (ETDEWEB)

    Carnel, S.B.; Blakeslee, D.B.; Oswald, S.G.; Barnes, M. (Fitzsimons Army Medical Center, Aurora, CO (USA))

    1990-04-01

    Severe stomatitis is a common problem encountered during either radiation therapy or chemotherapy. Most therapeutic regimens are empirical, with no scientific basis. The purpose of this study is to determine the efficacy of various topical solutions in the treatment of radiation- or chemotherapy-induced stomatitis. Eighteen patients were entered into a prospective double-blinded study to test several topical solutions: (1) viscous lidocaine with 1% cocaine; (2) dyclonine hydrochloride 1.0% (Dyclone); (3) kaolin-pectin solution, diphenhydramine plus saline (KBS); and (4) a placebo solution. Degree of pain relief, duration of relief, side effects, and palatability were evaluated. The results showed that Dyclone provided the most pain relief. Dyclone and viscous lidocaine with 1% cocaine provided the longest pain relief, which averaged 50 minutes This study provides objective data and defines useful guidelines for treatment of stomatitis.

  14. Acupuncture treatment of patients with radiation-induced xerostomia

    Energy Technology Data Exchange (ETDEWEB)

    Blom, M.; Dawidson, I.; Johnson, G.; Angmar-Maansson, B. [Karolinska Inst., Huddinge (Sweden). Dept. of Cardiology; Fernberg, J.-O. [Karolinska Hospital, Stockholm (Sweden). Dept. of General Oncology

    1996-05-01

    Xerostomia is a common and usually irreversible side effect in patients receiving radiation therapy (>50 Gy) for head and neck cancer. Of 38 patients with radiation-induced xerostomia, 20 in the experimental group were treated with classical acupuncture and 18 patients in the control group received superficial acupuncture as placebo. Within both groups the patients showed significantly increased salivary flow rates after the acupuncture treatment. In the experimental group 68% and in the control group 50% of the patients had increased salivary flow rates at the end of the observation period. Among those patients who had had all their salivary glands irradiated, 50% in both groups showed increased salivary flow rates (>20%) by the end of the observation period of 1 year. The study indicates that among the patients who had increased salivary flow rates already after the first 12 acupuncture sessions, the majority had high probability of continual improvement after the completion of acupuncture treatment. (Author).

  15. Free Radical Oxidation Induced by Iron Metabolism Disorder in Femoral and Pelvic Fractures and Potential for Its Correction

    Directory of Open Access Journals (Sweden)

    Y. P. Orlov

    2016-01-01

    Full Text Available Objective: To determine the pathogenic significance of iron ions in the activation of free radical oxidation in trau matic disease and valuate the efficacy of Desferal in the complex therapy of patients with femoral and pelvic fractions.Materials and methods. Iron metabolism and the intensity of free radical oxidation have been studed in 30 patients with traumas. The patients were randomized into two groups by gender, age and the severity of injury. Group I (n=15 included the injured patients who received the standard intensive therapy. Group II (n=15 included the patients who were treated with Desferal of 8 mg/kg twice daily in 12 hours along with the intensive therapy. The control group comprized of 10 healthy individuals of the same age. The concentration of total and free hemoglobine, serum iron, transferrin, total antioxidant activity of blood serum, the intensity of free radical oxida tion by the Fe2+induced chemiluminescence and hemostatic parameters were studied on admittance as well as on 3rd and 5th day of hospitalization. The parameters of sistemic hemodyamics were checked by integral rheovasog raphy. Statistical processing of data was carried out using Biostat and MS Excel software. The results were pre sented as a mean and standart deviation (M±δ. The Student’s (t and MannWhitney tests were used to prove the hypotheses. The critical level of significance was P=0.05.Results. It was determined that the disorders of iron metabolism in patients with traumatic disease were accompanied by intra and extravascular hemolysis, the excess off reduced iron ions catalizing the free radical oxidation, and failure of antioxidant system and disorders of hemostatic system and central hemodynamics. Desferal lowered the level of reduced iron in blood serum, diminished the intensity of free radical oxidation and eliminated the disorders in hemostasis and systemic hemodynamics.Conclusion. Data confirm the pathogenic role of iron ions in the

  16. Simvastatin attenuates radiation-induced salivary gland dysfunction in mice

    Directory of Open Access Journals (Sweden)

    Xu L

    2016-07-01

    Full Text Available Liping Xu,* Xi Yang,* Jiayan Chen, Xiaolin Ge, Qin Qin, Hongcheng Zhu, Chi Zhang, Xinchen Sun Department of Radiation Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, People’s Republic of China *These authors contributed equally to this work Objective: Statins are widely used lipid-lowering drugs, which have pleiotropic effects, such as anti-inflammation, and vascular protection. In our study, we investigated the radioprotective potential of simvastatin (SIM in a murine model of radiation-induced salivary gland dysfunction. Design: Ninety-six Institute of Cancer Research mice were randomly divided into four groups: solvent + sham irradiation (IR (Group I, SIM + sham IR (Group II, IR + solvent (Group III, and IR + SIM (Group IV. SIM (10 mg/kg body weight, three times per week was administered intraperitoneally 1 week prior to IR through to the end of the experiment. Saliva and submandibular gland tissues were obtained for biochemical, morphological (hematoxylin and eosin staining and Masson’s trichrome, and Western blot analysis at 8 hours, 24 hours, and 4 weeks after head and neck IR. Results: IR caused a significant reduction of salivary secretion and amylase activity but elevation of malondialdehyde. SIM remitted the reduction of saliva secretion and restored salivary amylase activity. The protective benefits of SIM may be attributed to scavenging malondialdehyde, remitting collagen deposition, and reducing and delaying the elevation of transforming growth factor β1 expression induced by radiation. Conclusion: SIM may be clinically useful to alleviate side effects of radiotherapy on salivary gland. Keywords: simvastatin, radiation protection, submandibular gland, transforming growth factor-β1, mice

  17. Interference effects in medium-induced gluon radiation

    CERN Document Server

    Casalderrey-Solana, Jorge

    2011-01-01

    As a step towards understanding the in-medium evolution of a hard jet, we consider the interference pattern for the medium induced gluon radiation produced by a color singlet quark-antiquark antenna embedded in a QCD medium with size L. We focus on the typical kinematics for medium-induced gluon radiation in the BDMPS-Z regime, that is, short formation times \\tau_f >\\theta_c = 2/\\sqrt{\\hat q L^3}, with \\hat q the `jet quenching' parameter. We demonstrate that, for a dipole opening angle \\theta_{q\\bar q} larger than \\theta_c, the interference between the medium-induced gluon emissions by the quark and the antiquark is parametrically suppressed with respect to the corresponding direct emissions. Physically, this is so since the direct emissions can be delocalized anywhere throughout the medium and thus yield contributions proportional to L. On the contrary, the interference occurs only between gluons emitted at very early times, within the characteristic time scales for quantum and color coherence between the t...

  18. Studies on chemical protectors against radiation, 33; Protective mechanisms of various compounds against skin injury induced by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Yushi; Kumazawa, Noriko; Suzuki, Makoto; Wang Cheng-Ming; Ohta, Setsuko; Shinoda, Masato (Hoshi Univ., Tokyo (Japan))

    1991-01-01

    The radiation protective mechanisms on skin injury induced by soft X-irradiation were investigated by use of various radiation protective agents such as sulfur compounds (MEA, MEG, thiourea), nucleic acid constitutional compounds (adenosine, inosine), antioxidative compounds (sesamol, ferulic acid, ascorbic acid), crude drugs (Rosae Fructus, Anemarrhenae Rhizoma, Trapae Fructus, Forsythiae Fructus, Aloe arborescens). Scavenge action of activated oxygen, inhibitory effect of lipid peroxidation, induction of antioxidative protein and protective effect against damage of deoxyribonucleic acid and superoxide dismutase by X-irradiation were evaluated as the radiation protective mechanisms, and relationship between these results and protective effect of skin injury induced by radiation was studied. (author).

  19. Metabolomic Analyses of Brain Tissue in Sepsis Induced by Cecal Ligation Reveal Specific Redox Alterations-Protective Effects of the Oxygen Radical Scavenger Edaravone

    DEFF Research Database (Denmark)

    Hara, Naomi; Chijiiwa, Miyuki; Yara, Miki

    2015-01-01

    at analyzing the preventive effect of the free radical scavenger edaravone on sepsis-induced brain alterations. Sepsis was induced by cecal ligation and puncture (CLP) and the mice were divided into three groups-CLP vehicle (CLPV), CLP and edaravone (MCI-186, 3-methyl-1-phenyl-2-pyrazolin-5-one) (CLPE...

  20. Galactic cosmic ray-induced radiation dose on terrestrial exoplanets.

    Science.gov (United States)

    Atri, Dimitra; Hariharan, B; Grießmeier, Jean-Mathias

    2013-10-01

    This past decade has seen tremendous advancements in the study of extrasolar planets. Observations are now made with increasing sophistication from both ground- and space-based instruments, and exoplanets are characterized with increasing precision. There is a class of particularly interesting exoplanets that reside in the habitable zone, which is defined as the area around a star where the planet is capable of supporting liquid water on its surface. Planetary systems around M dwarfs are considered to be prime candidates to search for life beyond the Solar System. Such planets are likely to be tidally locked and have close-in habitable zones. Theoretical calculations also suggest that close-in exoplanets are more likely to have weaker planetary magnetic fields, especially in the case of super-Earths. Such exoplanets are subjected to a high flux of galactic cosmic rays (GCRs) due to their weak magnetic moments. GCRs are energetic particles of astrophysical origin that strike the planetary atmosphere and produce secondary particles, including muons, which are highly penetrating. Some of these particles reach the planetary surface and contribute to the radiation dose. Along with the magnetic field, another factor governing the radiation dose is the depth of the planetary atmosphere. The higher the depth of the planetary atmosphere, the lower the flux of secondary particles will be on the surface. If the secondary particles are energetic enough, and their flux is sufficiently high, the radiation from muons can also impact the subsurface regions, such as in the case of Mars. If the radiation dose is too high, the chances of sustaining a long-term biosphere on the planet are very low. We have examined the dependence of the GCR-induced radiation dose on the strength of the planetary magnetic field and its atmospheric depth, and found that the latter is the decisive factor for the protection of a planetary biosphere.

  1. Antioxidative effects of Kimchi under different fermentation stage on radical-induced oxidative stress

    OpenAIRE

    Kim, Boh Kyung; Choi, Ji Myung; Kang, Soon Ah; Park, Kun Young; Cho, Eun Ju

    2014-01-01

    BACKGROUND/OBJECTIVES Kimchi is a traditional Korean fermented vegetable containing several ingredients. We investigated the protective activity of methanol extract of kimchi under different fermentation stages against oxidative damage. MATERIALS/METHODS Fresh kimchi (Fresh), optimally ripened kimchi (OptR), and over ripened kimchi (OvR) were fermented until the pH reached pH 5.6, pH 4.3, and pH 3.8, respectively. The radical scavenging activity and protective activity from oxidative stress o...

  2. Modern cataract surgery for radiation-induced cataracts in retinoblastoma.

    Science.gov (United States)

    Osman, Ihab M; Abouzeid, Hana; Balmer, Aubin; Gaillard, Marie-Claire; Othenin-Girard, Philippe; Pica, Alessia; Moeckli, Raphaël; Schorderet, Daniel F; Munier, Francis L

    2011-02-01

    Surgery of radiation-induced cataracts in children with retinoblastoma (RB) is a challenge as early intervention is weighted against the need to delay surgery until complete tumour control is obtained. This study analyses the safety and functional results of such surgery. In a retrospective, non-comparative, consecutive case series, we reviewed medical records of RB patients ≤ 14 y of age who underwent either external beam radiotherapy or plaque treatment and were operated for radiation-induced cataract between 1985 and 2008. In total, 21 eyes of 20 RB patients were included and 18 out of the 21 eyes had Reese-Ellsworth stage V or ABC classification group D/E RB. Median interval between last treatment for RB and cataract surgery was 21.5 months, range 3-164 months. Phacoaspiration was performed in 13 eyes (61%), extra-capsular cataract extraction in 8 (39%) and intraocular lens implantation in 19 eyes (90%). The majority of cases, 11/21 (52%), underwent posterior capsulorhexis or capsulotomy and 6/21 (28%) an anterior vitrectomy. Postoperative visual acuity was ≥ 20/200 in 13 eyes and < 20/200 in 5 eyes. Intraocular tumour recurrence was noted in three eyes. Mean postoperative follow up was 90 months ± 69 months. Modern cataract surgery, including clear cornea approach, lens aspiration with posterior capsulotomy, anterior vitrectomy and IOL implantation is a safe procedure for radiation-induced cataract as long as RB is controlled. The visual prognosis is limited by initial tumour involvement of the macula and by corneal complications of radiotherapy. We recommend a minimal interval of 9 months between completion of treatment of retinoblastoma and cataract surgery.

  3. Erythrocyte Stiffness during Morphological Remodeling Induced by Carbon Ion Radiation

    Science.gov (United States)

    Zhang, Baoping; Liu, Bin; Zhang, Hong; Wang, Jizeng

    2014-01-01

    The adverse effect induced by carbon ion radiation (CIR) is still an unavoidable hazard to the treatment object. Thus, evaluation of its adverse effects on the body is a critical problem with respect to radiation therapy. We aimed to investigate the change between the configuration and mechanical properties of erythrocytes induced by radiation and found differences in both the configuration and the mechanical properties with involving in morphological remodeling process. Syrian hamsters were subjected to whole-body irradiation with carbon ion beams (1, 2, 4, and 6 Gy) or X-rays (2, 4, 6, and 12 Gy) for 3, 14 and 28 days. Erythrocytes in peripheral blood and bone marrow were collected for cytomorphological analysis. The mechanical properties of the erythrocytes were determined using atomic force microscopy, and the expression of the cytoskeletal protein spectrin-α1 was analyzed via western blotting. The results showed that dynamic changes were evident in erythrocytes exposed to different doses of carbon ion beams compared with X-rays and the control (0 Gy). The magnitude of impairment of the cell number and cellular morphology manifested the subtle variation according to the irradiation dose. In particular, the differences in the size, shape and mechanical properties of the erythrocytes were well exhibited. Furthermore, immunoblot data showed that the expression of the cytoskeletal protein spectrin-α1 was changed after irradiation, and there was a common pattern among its substantive characteristics in the irradiated group. Based on these findings, the present study concluded that CIR could induce a change in mechanical properties during morphological remodeling of erythrocytes. According to the unique characteristics of the biomechanical categories, we deduce that changes in cytomorphology and mechanical properties can be measured to evaluate the adverse effects generated by tumor radiotherapy. Additionally, for the first time, the current study provides a new

  4. A model of radiatively induced quark and lepton mass model

    Science.gov (United States)

    Nomura, Takaaki

    2017-07-01

    We discuss a radiatively induced quark and lepton mass model in the rst and second generation introducing extra U(1) gauge symmetry, discrete Z 2 symmetry, vector-like fermions and exotic scalar elds. Then we analyze the allowed parameter regions which simultaneously satisfy the constraints of FCNCs for the quark sector and of LFVs including μ - e conversion, observed quark mass and mixing, and the lepton mass and mixing. In addition, the typical value for the (g - 2) μ in our model is presented. We also show extension of the model in which Majorana type neutrino masses are generated at the two loop level.

  5. Antioxidant Responses Induced by UVB Radiation in Deschampsia antarctica Desv.

    OpenAIRE

    K?hler, Hans; Contreras, Rodrigo A.; Pizarro, Marisol; Cort?s-Ant?quera, Rodrigo; Z??iga, Gustavo E.

    2017-01-01

    Deschampsia antarctica Desv. is one of two vascular plants that live in the Maritime Antarctic Territory and is exposed to high levels of ultraviolet-B (UVB) radiation. In this work, antioxidant physiology of D. antarctica was studied in response to UVB induced oxidative changes. Samples were collected from Antarctica and maintained in vitro culture during 2 years. Plants were sub-cultured in a hydroponic system and exposed to 21.4 kJ m-2 day-1, emulating summer Antarctic conditions. Results ...

  6. Radiation induced skin cancer the chest wall 30 years later from breast cancer operation

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Kouji; Togawa, Tamotsu; Hasegawa, Takeshi; Matsunami, Hidetoshi; Ikeda, Tsuneko [Matsunami General Hospital, Kasamatsu, Gifu (Japan); Matsuo, Youichi

    1998-10-01

    This paper describes the skin cancer on the frontal chest wall induced by postoperative irradiation 30 years later from mastectomy. The patients was a 62-year-old woman, who received mastectomy of the right breast cancer (invasive ductal carcinoma, comedo type) at 31 years old, and received the postoperative radiotherapy of total 11,628 rad over 38 times. On the first medical examination in author`s hospital, the patient had an ulcer of about 10 cm diameter and was diagnosed the radiation induced skin cancer (well differentiated squamous cell carcinoma) in the biopsy. Because of the general condition of the patient was extremely bad and the skin cancer had highly developed, the excision was thought to be impossible. The radiotherapy (16 Gy) and combined local chemotherapy by OK 432 and Bleomycin were performed. In spite of the short term treatment, these therapies were effective on the reduction of the tumor size and the hemostasis, and brought the patient the improvement of QOL. The general condition of the patient improved to be stable and she recovered enough to go out from the hospital for 6 months. After 10 months, she showed anorexia and dyspnea and died after about 1 year from the admission. The present case is extremely rare, and it is required the radical therapy like the excision of chest wall at early stage. (K.H.)

  7. Nicotinamide prevents ultraviolet radiation-induced cellular energy loss.

    Science.gov (United States)

    Park, Joohong; Halliday, Gary M; Surjana, Devita; Damian, Diona L

    2010-01-01

    UV radiation is carcinogenic by causing mutations in the skin and also by suppressing cutaneous antitumor immunity. We previously found nicotinamide (vitamin B3) to be highly effective at reducing UV-induced immunosuppression in human volunteers, with microarray studies on in vivo irradiated human skin suggesting that nicotinamide normalizes subsets of apoptosis, immune function and energy metabolism-related genes that are downregulated by UV exposure. Using human adult low calcium temperature keratinocytes, we further investigated nicotinamide's effects on cellular energy metabolism. We found that nicotinamide prevented UV-induced cellular ATP loss and protected against UV-induced glycolytic blockade. To determine whether nicotinamide alters the effects of UV-induced oxidative stress posttranslationally, we also measured UV-induced reactive oxygen species (ROS). Nicotinamide had no effect on ROS formation, and at the low UV doses used in these studies, equivalent to ambient daily sun exposure, there was no evidence of apoptosis. Hence, nicotinamide appears to exert its UV protective effects on the skin via its role in cellular energy pathways.

  8. Mitigating HZE Radiation-Induced Deficits in Marrow-Derived Mesenchymal Progenitor Cells and Skeletal Structure

    Science.gov (United States)

    Globus, Ruth K.; Schreurs, Ann-Sofie; Shirazi-Fard, Yasaman; Terada, Masahiro; Alwood, Joshua; Halloran, Bernard; Tahimic, Candice

    2016-01-01

    Future long-duration space exploration beyond the earths magnetosphere will increase human exposure to space radiation and associated risks to skeletal health. We hypothesize that oxidative stress resulting from radiation exposure causes progressive bone loss and dysfunction in associated tissue. In animal studies, increased free radical formation is associated with pathological changes in bone structure, enhanced bone resorption, reduced bone formation and decreased bone mineral density, which can lead to skeletal fragility.

  9. Radiation-induced heart disease in lung cancer radiotherapy

    Science.gov (United States)

    Ming, Xin; Feng, Yuanming; Yang, Chengwen; Wang, Wei; Wang, Ping; Deng, Jun

    2016-01-01

    Abstract Background: Radiation-induced heart disease (RIHD), which affects the patients’ prognosis with both acute and late side effects, has been published extensively in the radiotherapy of breast cancer, lymphoma and other benign diseases. Studies on RIHD in lung cancer radiotherapy, however, are less extensive and clear even though the patients with lung cancer are delivered with higher doses to the heart during radiation treatment. Methods: In this article, after extensive literature search and analysis, we reviewed the current evidence on RIHD in lung cancer patients after their radiation treatments and investigated the potential risk factors for RIHD as compared to other types of cancers. Result: Cardiac toxicity has been found highly relevant in lung cancer radiotherapy. So far, the crude incidence of cardiac complications in the lung cancer patients after radiotherapy has been up to 33%. Conclusion: The dose to the heart, the lobar location of tumor, the treatment modality, the history of heart and pulmonary disease and smoking were considered as potential risk factors for RIHD in lung cancer radiotherapy. As treatment techniques improve over the time with better prognosis for lung cancer survivors, an improved prediction model can be established to further reduce the cardiac toxicity in lung cancer radiotherapy. PMID:27741117

  10. UVB radiation induced effects on cells studied by FTIR spectroscopy

    CERN Document Server

    Di Giambattista, Lucia; Gaudenzi, S; Pozzi, D; Grandi, M; Morrone, S; Silvestri, I; Castellano, A Congiu; 10.1007/s00249-009-0446-9

    2010-01-01

    We have made a preliminary analysis of the results about the eVects on tumoral cell line (lymphoid T cell line Jurkat) induced by UVB radiation (dose of 310 mJ/cm^2) with and without a vegetable mixture. In the present study, we have used two techniques: Fourier transform infrared spectroscopy (FTIR) and flow cytometry. FTIR spectroscopy has the potential to provide the identiWcation of the vibrational modes of some of the major compounds (lipid, proteins and nucleic acids) without being invasive in the biomaterials. The second technique has allowed us to perform measurements of cytotoxicity and to assess the percentage of apoptosis. We already studied the induction of apoptotic process in the same cell line by UVB radiation; in particular, we looked for correspondences and correlations between FTIR spetroscopy and flow cytometry data finding three highly probable spectroscopic markers of apoptosis (Pozzi et al. in Radiat Res 168:698-705, 2007). In the present work, the results have shown significant changes ...

  11. Mitochondrial mutagenesis induced by tumor-specific radiation bystander effects.

    LENUS (Irish Health Repository)

    Gorman, Sheeona

    2012-02-01

    The radiation bystander effect is a cellular process whereby cells not directly exposed to radiation display cellular alterations similar to directly irradiated cells. Cellular targets including mitochondria have been postulated to play a significant role in this process. In this study, we utilized the Random Mutation Capture assay to quantify the levels of random mutations and deletions in the mitochondrial genome of bystander cells. A significant increase in the frequency of random mitochondrial mutations was found at 24 h in bystander cells exposed to conditioned media from irradiated tumor explants (p = 0.018). CG:TA mutations were the most abundant lesion induced. A transient increase in the frequency of random mitochondrial deletions was also detected in bystander cells exposed to conditioned media from tumor but not normal tissue at 24 h (p = 0.028). The increase in both point mutations and deletions was transient and not detected at 72 h. To further investigate mitochondrial dysfunction, mitochondrial membrane potential and reactive oxygen species were assessed in these bystander cells. There was a significant reduction in mitochondrial membrane potential and this was positively associated with the frequency of random point mutation and deletions in bystander cells treated with conditioned media from tumor tissue (r = 0.71, p = 0.02). This study has shown that mitochondrial genome alterations are an acute consequence of the radiation bystander effect secondary to mitochondrial dysfunction and suggests that this cannot be solely attributable to changes in ROS levels alone.

  12. Investigation of mutations induced by radiation and restriction endonucleases

    Science.gov (United States)

    Haworth, Kim E.

    The effects of gamma radiation and restriction endonuclease (RE) induced DNA double strand breaks (dsb) upon the mutation frequency and the surviving fraction of three Chinese hamster cell lines V79-4, CHO-K1 and an X-ray sensitive dsb repair deficient cell line xrs-5 were studied. The X-ray sensitive xrs-5 cell line was shown to be more sensitive to both the lethal and the mutagenic effects of gamma radiation having a substantially lower surviving fraction and a higher thymidine kinase (tk) mutation frequency per unit dose than the parental CHO-K1 cells. The frequency of induced hprt- mutations in the V79-4 cell line was comparable to the induced frequency of tk mutations in the CHO-K1 cells. The effect of blunt- and cohesive- ended dsb upon the surviving fraction and the induced mutation frequency was studied by porating different Chinese hamster cell lines (CHO-K1, V79-4 and xrs-5) with RE using Streptolysin O (SLO). The surviving fraction of the different cell lines was reduced with increasing concentrations of Pvu II. Increases in the concentration of Pvu II produced increases in the frequency of hypoxyanthine guanine phosphoribosyl transferase (hprt) mutations in the V79-4 cells and tk mutations in the CHO-K1 and xrs-5 cells. However, the xrs-5 cells were shown to be hypomutable to Pvu II compared with the parental CHO-K1 cells. EcoR1 was ineffective at inducing tk mutations in the CHO-Kl cells but was as effective as Pvu II at inducing hprt mutations in the V79-4 cells. None of the spontaneously induced V79-4 hprt- mutant cells were shown to have observable molecular deletions when analysed by PCR deletion screening. One third of the radiation induced hprt - mutants were shown to be deletions. However, too few mutant cells were analysed for any non-random distribution of deletions to be observed. Half of the hprt- mutants induced by SLO poration alone were shown to be due to deletions of oi\\e or more exons. The distribution of the DNA deletions in SLO hprt

  13. Analysis of free-radical scavenging of Yerba Mate (Ilex paraguriensis) using electron spin resonance and radical-induced DNA damage.

    Science.gov (United States)

    Leonard, Stephen S; Hogans, Vallie J; Coppes-Petricorena, Zulema; Peer, Cody J; Vining, Timothy A; Fleming, David W; Harris, Gabriel K

    2010-01-01

    Mate (MT) is a popular South American beverage that has been used as a traditional medicine for centuries, spurring recent interest in its nutraceutical properties. MT is prepared as an infusion of leaves from the Yerba Mate (llex paraguriensis) tree. MT has been reported to have antioxidant properties in vitro and in vivo, but these have not been fully characterized in terms of effects against specific radicals. Accordingly, we examined the antioxidant effects of an MT infusion against hydroxyl and superoxide radicals in both chemical and cell culture assays. MT infusions were prepared at 3.10 g/L in boiling water and diluted to experimental dilutions from this stock. Electron spin resonance (ESR) experiments indicated that MT scavenged hydroxyl radicals (produced via the Fenton reaction) and superoxide radicals (produced via the xanthine/xanthine oxidase enzymatic reaction) at all concentrations tested (P chemical and cell culture systems, as well as DNA-protective properties. These data further clarify the reported antioxidant effects of Yerba Mate infusions.

  14. Effect of Cynara Scolymus L. (Artichoke) Extraction on Hyperlipidemic Induced by Gamma Radiation in Male Rats

    OpenAIRE

    Amal A. A. Ammar and Tamer M. M. Saad

    2012-01-01

    Excessive free radicals are caused by unnatural environmental influences such as air pollution, radiation, cigarette smoke, factories, pesticides, food contaminants and a myriad of other factor that are part of our modern life. Hypercholesterolaemia is directly associated with an increased risk of coronary heart disease (CHD). ...

  15. Radiation-induced formation of 8-hydroxy-2'-deoxyguanosine and its prevention by scavengers

    DEFF Research Database (Denmark)

    Fischer-Nielsen, A; Jeding, I B; Loft, S

    1994-01-01

    measured 8-OHdG formation in calf thymus DNA exposed to ionizing radiation under conditions generating either hydroxyl radicals (OH.), superoxide anions (O2-) or both. Additionally, we investigated the relationship between the scavenger effect of the drug 5-aminosalicylic acid (5-ASA) and increasing OH...

  16. Radiation-induced bystander effects in cultured human stem cells.

    Directory of Open Access Journals (Sweden)

    Mykyta V Sokolov

    2010-12-01

    Full Text Available The radiation-induced "bystander effect" (RIBE was shown to occur in a number of experimental systems both in vitro and in vivo as a result of exposure to ionizing radiation (IR. RIBE manifests itself by intercellular communication from irradiated cells to non-irradiated cells which may cause DNA damage and eventual death in these bystander cells. It is known that human stem cells (hSC are ultimately involved in numerous crucial biological processes such as embryologic development; maintenance of normal homeostasis; aging; and aging-related pathologies such as cancerogenesis and other diseases. However, very little is known about radiation-induced bystander effect in hSC. To mechanistically interrogate RIBE responses and to gain novel insights into RIBE specifically in hSC compartment, both medium transfer and cell co-culture bystander protocols were employed.Human bone-marrow mesenchymal stem cells (hMSC and embryonic stem cells (hESC were irradiated with doses 0.2 Gy, 2 Gy and 10 Gy of X-rays, allowed to recover either for 1 hr or 24 hr. Then conditioned medium was collected and transferred to non-irradiated hSC for time course studies. In addition, irradiated hMSC were labeled with a vital CMRA dye and co-cultured with non-irradiated bystander hMSC. The medium transfer data showed no evidence for RIBE either in hMSC and hESC by the criteria of induction of DNA damage and for apoptotic cell death compared to non-irradiated cells (p>0.05. A lack of robust RIBE was also demonstrated in hMSC co-cultured with irradiated cells (p>0.05.These data indicate that hSC might not be susceptible to damaging effects of RIBE signaling compared to differentiated adult human somatic cells as shown previously. This finding could have profound implications in a field of radiation biology/oncology, in evaluating radiation risk of IR exposures, and for the safety and efficacy of hSC regenerative-based therapies.

  17. Radiation-Induced Bystander Effects in Cultured Human Stem Cells

    Science.gov (United States)

    Sokolov, Mykyta V.; Neumann, Ronald D.

    2010-01-01

    Background The radiation-induced “bystander effect” (RIBE) was shown to occur in a number of experimental systems both in vitro and in vivo as a result of exposure to ionizing radiation (IR). RIBE manifests itself by intercellular communication from irradiated cells to non-irradiated cells which may cause DNA damage and eventual death in these bystander cells. It is known that human stem cells (hSC) are ultimately involved in numerous crucial biological processes such as embryologic development; maintenance of normal homeostasis; aging; and aging-related pathologies such as cancerogenesis and other diseases. However, very little is known about radiation-induced bystander effect in hSC. To mechanistically interrogate RIBE responses and to gain novel insights into RIBE specifically in hSC compartment, both medium transfer and cell co-culture bystander protocols were employed. Methodology/Principal Findings Human bone-marrow mesenchymal stem cells (hMSC) and embryonic stem cells (hESC) were irradiated with doses 0.2 Gy, 2 Gy and 10 Gy of X-rays, allowed to recover either for 1 hr or 24 hr. Then conditioned medium was collected and transferred to non-irradiated hSC for time course studies. In addition, irradiated hMSC were labeled with a vital CMRA dye and co-cultured with non-irradiated bystander hMSC. The medium transfer data showed no evidence for RIBE either in hMSC and hESC by the criteria of induction of DNA damage and for apoptotic cell death compared to non-irradiated cells (p>0.05). A lack of robust RIBE was also demonstrated in hMSC co-cultured with irradiated cells (p>0.05). Conclusions/Significance These data indicate that hSC might not be susceptible to damaging effects of RIBE signaling compared to differentiated adult human somatic cells as shown previously. This finding could have profound implications in a field of radiation biology/oncology, in evaluating radiation risk of IR exposures, and for the safety and efficacy of hSC regenerative

  18. Isostructural metal-anion radical coordination polymers with tunable phosphorescent colors (deep blue, blue, yellow, and white) induced by terminal anions and metal cations.

    Science.gov (United States)

    Yong, Guoping; Li, Yingzhou; She, Wenlong; Zhang, Yiman

    2011-10-24

    Five phosphorescent metal-anion radical coordination polymers based on a new anion radical ligand generated by in situ deprotonation of a stable zwitterionic radical are described. The N,O,N-tripodal anion radical ligand links metal cations, which leads to five isostructural coordination polymers, [M(3)(bipo(-.))(4)(L)(2)](n) (M=Cd or Mn, Hbipo(-.)=2,3'-biimidazo[1,2-a]pyridin-2'-one, L=Cl(-), HCOO(-) or SCN(-)). The isostructural coordination polymers exhibit novel one-dimensional spirocycle-like structures. Three isostructural Cd(II) coordination polymers display unusual phosphorescent color changes (blue, yellow, and white) induced by terminal anions. Significantly, the Cd(II) coordination polymer with terminal Cl(-) possesses moderate quantum yield, and shows a bright white-light phosphorescence emission, which is independent of excitation wavelength and can even be excited by visible light. Upon adjusting the metal cation to Mn(II), two isostructural Mn(II) coordination polymers reveal deep-blue-light phosphorescence emissions that are independent of terminal anions. As radical-based coordination polymers, some of them show antiferromagnetic interactions between radical species or radical and metal center. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Space-radiation-induced Photon Luminescence of the Moon

    Science.gov (United States)

    Wilson, Thomas; Lee, Kerry

    2008-01-01

    We report on the results of a study of the photon luminescence of the Moon induced by Galactic Cosmic Rays (GCRs) and space radiation from the Sun, using the Monte Carlo program FLUKA. The model of the lunar surface is taken to be the chemical composition of soils found at various landing sites during the Apollo and Luna programs, averaged over all such sites to define a generic regolith for the present analysis. This then becomes the target that is bombarded by Galactic Cosmic Rays (GCRs) and Solar Energetic Particles (SEPs) above 1 keV in FLUKA to determine the photon fluence albedo produced by the Moon's surface when there is no sunlight and Earthshine. This is to be distinguished from the gamma-ray spectrum produced by the radioactive decay of radiogenic constituents lying in the surface and interior of the Moon. From the photon fluence we derive the spectrum which can be utilized to examine existing lunar spectral data and to design orbiting instrumentation for measuring various components of the space-radiation-induced photon luminescence present on the Moon.

  20. Estimating radiation risk induced by CT screening for Korean population

    Science.gov (United States)

    Yang, Won Seok; Yang, Hye Jeong; Min, Byung In

    2017-02-01

    The purposes of this study are to estimate the radiation risks induced by chest/abdomen computed tomography (CT) screening for healthcare and to determine the cancer risk level of the Korean population compared to other populations. We used an ImPACT CT Patient Dosimetry Calculator to compute the organ effective dose induced by CT screening (chest, low-dose chest, abdomen/pelvis, and chest/abdomen/pelvis CT). A risk model was applied using principles based on the BEIR VII Report in order to estimate the lifetime attributable risk (LAR) using the Korean Life Table 2010. In addition, several countries including Hong Kong, the United States (U.S.), and the United Kingdom, were selected for comparison. Herein, each population exposed radiation dose of 100 mSv was classified according to country, gender and age. For each CT screening the total organ effective dose calculated by ImPACT was 6.2, 1.5, 5.2 and 11.4 mSv, respectively. In the case of Korean female LAR, it was similar to Hong Kong female but lower than those of U.S. and U.K. females, except for those in their twenties. The LAR of Korean males was the highest for all types of CT screening. However, the difference of the risk level was negligible because of the quite low value.

  1. Sestrin2 protects the myocardium against radiation-induced damage

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Yue-Can; Chi, Feng; Xing, Rui; Gao, Song; Chen, Jia-Jia; Duan, Qiong-Yu; Sun, Yu-Nan; Niu, Nan; Tang, Mei-Yue; Wu, Rong [Shengjing Hospital of China Medical University, Department of Medical Oncology, Cancer Center, Shenyang (China); Zeng, Jing [University of Washington School of Medicine, Department of Radiation Oncology, Seattle, WA (United States); Wang, Hong-Mei [Nanfang Hospital of Southern Medical University, Department of Radiation Oncology, Guangzhou (China)

    2016-05-15

    The purpose of this study was to investigate the role of Sestrin2 in response to radiation-induced injury to the heart and on the cardiomyopathy development in the mouse. Mice with genetic deletion of the Sestrin2 (Sestrin2 knockout mice [Sestrin2 KO]) and treatment with irradiation (22 or 15 Gy) were used as independent approaches to determine the role of Sestrin2. Echocardiography (before and after isoproterenol challenge) and left ventricular (LV) catheterization were performed to evaluate changes in LV dimensions and function. Masson's trichrome was used to assess myocardial fibrosis. Immunohistochemistry and Western blot were used to detect the capillary density. After 22 or 15 Gy irradiation, the LV ejection fraction (EF) was impaired in wt mice at 1 week and 4 months after irradiation when compared with sham irradiation. Compared to wt mice, Sestrin2 KO mice had significant reduction in reduced LVEF at 1 week and 4 months after irradiation. A significant increase in LV end-diastolic pressure and myocardial fibrosis and a significant decrease in capillary density were observed in irradiation-wt mice, as well as in irradiation-Sestrin2 KO mice. Sestrin2 involved in the regulation of cardiomyopathy (such as myocardial fibrosis) after irradiation. Overexpression of Sestrin2 might be useful in limiting radiation-induced myocardial injury. (orig.)

  2. Radiation-Induced Correlation between Molecules Nearby Metallic Antenna Array

    Directory of Open Access Journals (Sweden)

    Yoshiki Osaka

    2015-01-01

    Full Text Available We theoretically investigate optical absorption of molecules embedded nearby metallic antennas by using discrete dipole approximation method. It is found that the spectral peak of the absorption is shifted due to the radiation-induced correlation between the molecules. The most distinguishing feature of our work is to show that the shift is largely enhanced even when the individual molecules couple with localized surface plasmons near the different antennas. Specifically, we first consider the case that two sets of dimeric gold blocks with a spacing of a few nanometers are arranged and reveal that the intensity and spectral peak of the optical absorption strongly depend on the position of the molecules. In addition, when the dimeric blocks and the molecules are periodically arranged, the peak shift is found to increase up to ~1.2 meV (300 GHz. Because the radiation-induced correlation is essential for collective photon emission, our result implies the possibility of plasmon-assisted superfluorescence in designed antenna-molecule complex systems.

  3. Radiation-induced thyroid cancer after radiotherapy for childhood cancer

    Energy Technology Data Exchange (ETDEWEB)

    Jiravova, M. [Department of Nuclear Medicine and Endocrinology, Faculty Hospital Motol, Uk, Prague (Czech Republic)

    2012-07-01

    Full text of the publication follows: The thyroid gland in children is among the most sensitive organs to the carcinogenic effects of ionizing radiation, and very young children are at especially high risk. Due to extreme sensitivity of the thyroid gland in children, there is a risk of radiation - induced thyroid cancer even when the thyroid gland is outside the irradiated field. Increased incidence of thyroid cancer has been noted following radiotherapy not only for childhood Hodgkin disease (majority of observed patients), but also for non-Hodgkin lymphoma, neuroblastoma, Wilms tumor, acute lymphocytic leukemia and tumors of the central nervous system also. Radiation-induced tumors begin to appear 5-10 years after irradiation and excess risk persists for decades, perhaps for the remainder of life. The incidence of thyroid cancer is two- to threefold higher among females than males. Most of the thyroid cancers that occur in association with irradiation are of the papillary type, for which the cure rate is high if tumors are detected early. Our Department in co-operation with Department of Children Hematology and Oncology Charles University Second Faculty of Medicine and Faculty Hospital Motol monitors patients after therapy for cancer in childhood for the long term period. The monitoring is focused on detection of thyroid disorders that occur as last consequences of oncology therapy, especially early detection of nodular changes in thyroid gland and thyroid carcinogenesis. The survey presents two patients observed in our department that were diagnosed with the papillary thyroid carcinoma which occurred 15 and more years after radiotherapy for childhood cancer. After total thyroidectomy they underwent therapy with radioiodine. After radiotherapy it is necessary to pursue a long-term following and assure interdisciplinary co-operation which enables early detection of last consequences of radiotherapy, especially the most serious ones as secondary carcinogenesis

  4. Hydroxyl-radical-induced degradative oxidation of beta-lactam antibiotics in water: absolute rate constant measurements.

    Science.gov (United States)

    Dail, Michelle K; Mezyk, Stephen P

    2010-08-19

    The beta-lactam antibiotics are some of the most prevalent pharmaceutical contaminants currently being detected in aquatic environments. Because the presence of any trace level of antibiotic in water may adversely affect aquatic ecosystems and contribute to the production of antibiotic-resistant bacteria, active removal by additional water treatments, such as using advanced oxidation and reduction processes (AO/RPs), may be required. However, to ensure that any AOP treatment process occurs efficiently and quantitatively, a full understanding of the kinetics and mechanisms of all of the chemical reactions involved under the conditions of use is necessary. In this study, we report on our kinetic measurements for the hydroxyl-radical-induced oxidation of 11 beta-lactam antibiotics obtained using electron pulse radiolysis techniques. For the 5-member ring species, an average reaction rate constant of (7.9 +/- 0.8) x 10(9) M(-1) s(-1) was obtained, slightly faster than for the analogous 6-member ring containing antibiotics, (6.6 +/- 1.2) x 10(9) M(-1) s(-1). The consistency of these rate constants for each group infers a common reaction mechanism, consisting of the partitioning of the hydroxyl radical between addition to peripheral aromatic rings and reaction with the central double-ring core of these antibiotics.

  5. Supplementary data for the mechanism for cleavage of three typical glucosidic bonds induced by hydroxyl free radical

    Directory of Open Access Journals (Sweden)

    Yujie Dai

    2017-12-01

    Full Text Available The data presented in this article are related to the research article entitled “The mechanism for cleavage of three typical glucosidic bonds induced by hydroxyl free radical” (Dai et al., 2017 [1]. This article includes the structures of three kinds of disaccharides such as maltose, fructose and cellobiose, the diagrammatic sketch of the hydrogen abstraction reaction of the disaccharides by hydroxyl radical, the structure of the transition states for pyran ring opening of moiety A and cleavage of α(1→2 glycosidic bond starting from the hydrogen abstraction of C6–H in moiety A of sucrose, the transition state structure for cleavage of α(1→2 glycosidic bond starting from the hydrogen abstraction of C1′-H in moiety B of sucrose, the transition state structure, sketch for the reaction process and relative energy change of the reaction pathway for direct cleavage of α(1→4 glycosidic bond starting from hydrogen abstraction of C6′–H of moiety B of maltose.

  6. Aircraft-borne, laser-induced fluorescence instrument for the in situ detection of hydroxyl and hydroperoxyl radicals

    Science.gov (United States)

    Wennberg, P. O.; Cohen, R. C.; Hazen, N. L.; Lapson, L. B.; Allen, N. T.; Hanisco, T. F.; Oliver, J. F.; Lanham, N. W.; Demusz, J. N.; Anderson, J. G.

    1994-01-01

    The odd-hydrogen radicals OH and HO2 are central to most of the gas-phase chemical transformations that occur in the atmosphere. Of particular interest is the role that these species play in controlling the concentration of stratospheric ozone. This paper describes an instrument that measures both of these species at volume mixing ratios below one part in 10(exp 14) in the upper troposphere and lower stratosphere. The hydroxyl radical (OH) is measured by laser induced fluorescence at 309 nm. Tunable UV light is used to pump OH to the first electric state near 282 nm. the laser light is produced by a high-repetition rate pulsed dye-laser powered with all solid-state pump lasers. HO2 is measured as OH after gas-phase titration with nitric oxide. Measurements aboard a NASA ER-2 aircraft demonstrate the capability of this instrument to perform reliably with very high signal-to-noise ratios (greater than 30) achieved in short integration times (less than 20 sec).

  7. Reversible-Deactivation Radical Polymerization of Methyl Methacrylate Induced by Photochemical Reduction of Various Copper Catalysts

    Directory of Open Access Journals (Sweden)

    Jaroslav Mosnáček

    2014-11-01

    Full Text Available Photochemically mediated reversible-deactivation radical polymerization of methyl methacrylate was successfully performed using 50–400 ppm of various copper compounds such as CuSO4·5H2O, copper acetate, copper triflate and copper acetylacetonate as catalysts. The copper catalysts were reduced in situ by irradiation at wavelengths of 366–546 nm, without using any additional reducing agent. Bromopropionitrile was used as an initiator. The effects of various solvents and the concentration and structure of ligands were investigated. Well-defined polymers were obtained when at least 100 or 200 ppm of any catalyst complexed with excess tris(2-pyridylmethylamine as a ligand was used in dimethyl sulfoxide as a solvent.

  8. 3-Hydroxylysine, a potential marker for studying radical-induced protein oxidation

    DEFF Research Database (Denmark)

    Morin, B; Bubb, W A; Davies, Michael Jonathan

    1998-01-01

    albumin (BSA) and human low-density lipoprotein (LDL)] and diseased human tissues (atherosclerotic plaques and lens cataractous proteins). This work was aimed at investigating oxidized lysine as a sensitive marker for protein oxidation, as such residues are present on protein surfaces, and are therefore...... hydroxylysines are however useful markers, with HPLC analysis of 9-fluorenylmethyl chloroformate (FMOC) derivatives providing a sensitive and accurate method for quantitative measurement. Hydroxylysines have been detected in the hydrolysates of peptides (Gly-Lys-Gly and Lys-Val-Ile-Leu-Phe) and proteins (BSA...... with globular proteins such as BSA. Hydroxylysines, and particularly 3-hydroxylysine, may therefore be sensitive and useful markers of radical-mediated protein oxidation in biological systems....

  9. Radiation therapy after radical prostatectomy for prostate cancer: evaluation of complications and influence of radiation timing on outcomes in a large, population-based cohort.

    Directory of Open Access Journals (Sweden)

    Sarah E Hegarty

    Full Text Available To evaluate the influence of timing of salvage and adjuvant radiation therapy on outcomes after prostatectomy for prostate cancer.Using the Surveillance, Epidemiology, and End Results-Medicare linked database, we identified prostate cancer patients diagnosed during 1995-2007 who had one or more adverse pathological features after prostatectomy. The final cohort of 6,137 eligible patients included men who received prostatectomy alone (n = 4,509 or with adjuvant (n = 894 or salvage (n = 734 radiation therapy. Primary outcomes were genitourinary, gastrointestinal, and erectile dysfunction events and survival after treatment(s.Radiation therapy after prostatectomy was associated with higher rates of gastrointestinal and genitourinary events, but not erectile dysfunction. In adjusted models, earlier treatment with adjuvant radiation therapy was not associated with increased rates of genitourinary or erectile dysfunction events compared to delayed salvage radiation therapy. Early adjuvant radiation therapy was associated with lower rates of gastrointestinal events that salvage radiation therapy, with hazard ratios of 0.80 (95% CI, 0.67-0.95 for procedure-defined and 0.70 (95% CI, 0.59, 0.83 for diagnosis-defined events. There was no significant difference between ART and non-ART groups (SRT or RP alone for overall survival (HR = 1.13 95% CI = (0.96, 1.34 p = 0.148.Radiation therapy after prostatectomy is associated with increased rates of gastrointestinal and genitourinary events. However, earlier radiation therapy is not associated with higher rates of gastrointestinal, genitourinary or sexual events. These findings oppose the conventional belief that delaying radiation therapy reduces the risk of radiation-related complications.

  10. The influence of oxygen on radiation-induced structural and functional changes in glyceraldehyde-3-phosphate dehydrogenase and lactate dehydrogenase

    Science.gov (United States)

    Rodacka, Aleksandra; Serafin, Eligiusz; Bubinski, Michal; Krokosz, Anita; Puchala, Mieczyslaw

    2012-07-01

    Proteins are major targets for oxidative damage due to their abundance in cells and high reactivity with free radicals. In the present study we examined the influence of oxygen on radiation-induced inactivation and structural changes of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and lactate dehydrogenase (LDH). We chose these two enzymes because they occur at high concentrations and participate in the most important processes in organisms; furthermore, they show considerable similarity in their structure. Protein solutions were irradiated with X-rays in doses ranging from 0.1 to 0.7 kGy, in air and N2O. The much higher radiation inactivation of GAPDH as compared to LDH is correlated with substantially greater structural changes in this protein, mainly involving the loss of free thiol groups (-SH). Of lesser importance in the differentiation of the radiosensitivity of the studied enzymes are tryptophan residues. Molecular oxygen, present during irradiation, increased to a significantly greater extent the inactivation and structural changes of GAPDH than that of LDH. The results suggest that the greater effect of oxygen on GAPDH is due to the higher efficiency of the superoxide radical, the higher amount of hydroperoxides generated, and the higher degree of unfolding of this protein.

  11. Radiation-induced bystander effect in healthy G{sub 0} human lymphocytes: Biological and clinical significance

    Energy Technology Data Exchange (ETDEWEB)

    Belloni, Paola; Latini, Paolo [Department of Agrobiology and Agrochemistry, University of Tuscia, Via San Camillo De Lellis, I-01100 Viterbo (Italy); Palitti, Fabrizio, E-mail: palitti@unitus.it [Department of Agrobiology and Agrochemistry, University of Tuscia, Via San Camillo De Lellis, I-01100 Viterbo (Italy)

    2011-08-01

    To study the bystander effects, G{sub 0} human peripheral blood lymphocytes were X-irradiated with 0.1, 0.5 and 3 Gy. After 24 h, cell-free conditioned media from irradiated cultures were transferred to unexposed lymphocytes. Following 48 h of medium transfer, viability, induction of apoptosis, telomere shortening, reactive oxygen species (ROS) levels and micronuclei (after stimulation) were analyzed. A statistically significant decrement in cell viability, concomitant with the loss of mitochondrial membrane potential, telomere shortening, increases in hydrogen peroxide (H{sub 2}O{sub 2}) and superoxide anion (O{sub 2}{sup -}) with depletion of intracellular glutathione (GSH) level, and higher frequencies of micronuclei, were observed in bystander lymphocytes incubated with medium from 0.5 and 3 Gy irradiated samples, compared to lymphocytes unexposed. Furthermore, no statistically significant difference between the response to 0.5 and 3 Gy of irradiation in bystander lymphocytes, was found. However, when lymphocytes were irradiated with 0.1 Gy, no bystander effect with regard to viability, apoptosis, telomere length, and micronuclei was observed, although a high production of ROS level persisted. Radiation in the presence of the radical scavenger dimethyl sulfoxide (DMSO) suppressed oxidative stress induced by 3 Gy of X-rays with the effective elimination of bystander effects, suggesting a correlation between ROS and bystander signal formation in irradiated cells. The data propose that bystander effect might be mostly due to the reactions of radiation induced free radicals on DNA, with the existence of a threshold at which the bystander signal is not operative (0.1 Gy dose of X-rays). Our results may have clinical implications for health risk associated with radiation exposure.

  12. Dried Plum Protects From Radiation-Induced Bone Loss by Attenuating Pro-Osteoclastic and Oxidative Stress Responses

    Science.gov (United States)

    Globus, Ruth

    2015-01-01

    Future space explorations beyond the earths magnetosphere will increase human exposure to space radiation and associated risks to skeletal health. We hypothesize that oxidative stress resulting from radiation exposure plays a major role in progressive bone loss and dysfunction in associated tissue. In animal studies, increased free radical formation is associated with pathological changes in bone structure, enhanced bone resorption, reduced bone formation and decreased bone mineral density, which can lead to skeletal fragility. Our long-term goals are to define the mechanisms and risk of bone loss in the spaceflight environment and to facilitate the development of effective countermeasures. We had previously reported that exposure to low or high-LET radiation correlates with an acute increase in the expression of pro-osteoclastic and oxidative stress genes in bone during the early response to radiation followed by pathological changes in skeletal structure. We then conducted systematic screening for potential countermeasures against bone loss where we tested the ability of various antioxidants to mitigate the radiation-induced increase in expression of these markers. For the screen, 16-week old C57Bl6J mice were treated with a dietary antioxidant cocktail, injectable DHLA or a dried plum-enriched diet (DP). Mice were then exposed to 2Gy 137Cs radiation and one day later, marrow cells were collected and the relevant genes analyzed for expression levels. Among the candidate countermeasures tested, DP was most effective in reducing the expression of genes associated with bone loss. Furthermore, analysis of skeletal structure by microcomputed tomography (microCT) revealed that DP also prevents the radiation-induced deterioration in skeletal microarchitecture as indicated by parameters such as percent bone volume (BVTV), trabecular spacing and trabecular number. We also found that DP has similar protective effects on skeletal structure in a follow-up study using 1 Gy of

  13. Intercomparison of OH Radical Measurements by Long-Path Absorption and Laser Induced Fluorescence in the Atmosphere Simulation Chamber SAPHIR

    Science.gov (United States)

    Dorn, H.-P.; Brauers, T.; Greif, J.; Häseler, R.; Hofzumahaus, A.; Holland, F.; Rupp, L.

    2003-04-01

    A striking advantage of the SAPHIR chamber is the availability of two spectroscopic detection instruments for OH radicals: Laser-Induced Fluorescence Spectroscopy (LIF) and Long-Path Differential Optical Laser Absorption Spectroscopy (DOAS). Both instruments have already been compared in 1994 during the field measurement campaign POPCORN. They agreed well with a correlation coefficient of r=0.90 and a weighted linear fit with a slope of 1.09 +- 0.12. However, OH measurements in the simulation chamber differ significantly from measurements in ambient air. While DOAS measures OH as an integral value along the central longitudinal axis of SAPHIR, LIF samples the air locally and close (2 cm) to the floor of the chamber. Thus, the LIF measurements might be possibly affected by local concentration gradients caused by insufficient mixing of the chamber air or by deposition to the wall. On the other hand, if turbulent mixing of the chamber air is weak and high concentrations of ozone are used in experiments, the DOAS instrument might be subject to artificial formation of OH radicals in the air volume which is illuminated by the detection laser. This interference results from laser induced photolysis of ozone and the subsequent reaction of water vapor with the excited oxygen atoms formed. Thus it is of decisive importance to compare OH measurements from both instruments in order to investigate potential disturbing effects due to the specific sampling properties of both instruments within SAPHIR. We report on OH measurements accomplished simultaneously with both instruments using different trace gas compositions and experimental conditions.

  14. Robot Assisted Radical Prostatectomy in A Patient with Previous Abdominoperineal Resection and Pelvic External Beam Radiation Therapy.

    Science.gov (United States)

    Cem, Basatac; Haluk, Akpinar

    2017-12-26

    Though previous major abdominal surgery and pelvic irradiation may be a significant drawback of subsequent laparoscopic procedure, technological advances such as better visualization and more controlled finer movementsof robotic arms allowing better dissection in robotic-assisted laparoscopic surgery may reduce some of these challenges. However, limited data are available on the effect and safety of robotic surgery in these patients. The aim of this case report is to present efficacy and safety of robot assisted radical prostatectomy in a patient who has rectal and concurrent prostate cancer with the history of abdominoperineal resection, pelvic irradiation and adjuvantchemotherapy.

  15. Modulation of radiation-induced changes in the xanthine oxidoreductase system in the livers of mice by its inhibitors.

    Science.gov (United States)

    Srivastava, M; Chandra, D; Kale, R K

    2002-03-01

    The xanthine oxidoreductase (XOD) system, which consists of xanthine dehydrogenase (XDH) and xanthine oxidase (XO), is one of the major sources of free radicals in biological systems. The XOD system is present predominantly in the normal tissues as XDH. In damaged tissues, XDH is converted into XO, the form that generates free radicals. Therefore, the XO form of the XOD system is expected to be found mainly in radiolytically damaged tissue. In this case, XO may catalyze the generation of free radicals and potentiate the effect of radiation. Inhibition of the XOD system is likely to attenuate the detrimental effects of ionizing radiation. We have examined this possibility using allopurinol and folic acid, which are known inhibitors of the XOD system. Swiss albino mice (7-8 weeks old) were given single doses of allopurinol and folic acid (12.5-50 mg/kg) intraperitoneally and irradiated with different doses of gamma radiation at a dose rate of 0.023 Gy/s. The XO and XDH activities as well as peroxidative damage and lactate dehydrogenase (LDH) were determined in the liver. An enhancement of the activity of XO and a simultaneous decrease in the activity of XDH were observed at doses above 3 Gy. The decrease in the ratio XDH/XO and the unchanged total activity (XDH + XO) suggested the conversion of XDH into XO. The enhanced activity of XO may potentiate radiation damage. The increased levels of peroxidative damage and the specific activity of LDH in the livers of irradiated mice supported this possibility. Allopurinol and folic acid inhibited the activities of XDH and XO, decreased their ratio (XDH/XO), and lowered the levels of peroxidative damage and the specific activity of LDH. These results suggested that allopurinol and folic acid have the ability to inhibit the radiation-induced changes in the activities of XDH and XO and to attenuate the detrimental effect of this conversion, as is evident from the diminished levels of peroxidative damage and the decreased

  16. Radiation-induced vulvar angiokeratoma along with other late radiation toxicities after carcinoma cervix: A rare case report

    Directory of Open Access Journals (Sweden)

    Virendra Bhandari

    2016-01-01

    Full Text Available Angiokeratoma including vulvar angiokeratoma is a very rare complication of radiation. Exact incidence is still unknown, we report a case that developed radiation-induced angiokeratoma of skin in the vulvar region along with other late radiation sequelae in the form of bone fracture, new bone formation, bone marrow widening, muscle hypertrophy, and subcutaneous fibrosis, 18 years after radiotherapy to the pelvic region for the treatment of carcinoma cervix. All these late radiation sequel are rare to be seen in a single patient, and none of the case reports could be found in the world literature.

  17. Radiation chemistry comes before radiation biology.

    Science.gov (United States)

    O'Neill, Peter; Wardman, Peter

    2009-01-01

    This article seeks to illustrate some contributions of radiation chemistry to radiobiology and related science, and to draw attention to examples where radiation chemistry is central to our knowledge of specific aspects. Radiation chemistry is a mature branch of radiation science which is continually evolving and finding wider applications. This is particularly apparent in the study of the roles of free radicals in biology generally, and radiation biology specifically. The chemical viewpoint helps unite the spatial and temporal insight coming from radiation physics with the diversity of biological responses. While historically, the main application of radiation chemistry of relevance to radiation biology has been investigations of the free-radical processes leading to radiation-induced DNA damage and its chemical characterization, two features of radiation chemistry point to its wider importance. First, its emphasis on quantification and characterization at the molecular level helps provide links between DNA damage, biochemical repair processes, and mutagenicity and radiosensitivity. Second, its central pillar of chemical kinetics aids understanding of the roles of 'reactive oxygen species' in cell signalling and diverse biological effects more generally, and application of radiation chemistry in the development of drugs to enhance radiotherapy and as hypoxia-specific cytotoxins or diagnostic agents. The illustrations of the broader applications of radiation chemistry in this article focus on their relevance to radiation biology and demonstrate the importance of synergy in the radiation sciences. The past contributions of radiation chemistry to radiation biology are evident, but there remains considerable potential to help advance future biological understanding using the knowledge and techniques of radiation chemistry.

  18. Counteracting effects on free radicals and histological alterations induced by a fraction with casearins

    Directory of Open Access Journals (Sweden)

    ÉVERTON JOSÉ FERREIRA DE ARAÚJO

    2015-09-01

    Full Text Available ABSTRACTCasearia sylvestris Swartz is a medicinal plant widely distributed in Brazil. It has anti-inflammatory, antiulcer and antitumor activities and is popularly used to treat snakebites, wounds, diarrhea, flu and chest colds. Its leaves are rich in oxygenated tricyclic cis-clerodane diterpenes, particulary casearins. Herein, we evaluated the antioxidant activities of a fraction with casearins (FC isolated from C. sylvestrisand histological changes on the central nervous system and livers of Mus musculus mice. Firstly, in vitro studies (0.9, 1.8, 3.6, 5.4 and 7.2 μg/mL revealed EC50 values of 3.7, 6.4 and 0.16 µg/mL for nitrite, hydroxyl radical and TBARS levels, respectively. Secondly, FC (2.5, 5, 10 and 25 mg/kg/day was intraperitoneally administered to Swiss mice for 7 consecutive days. Nitrite levels in the hippocampus (26.2, 27.3, 30.2 and 26.6 µM and striatum (26.3, 25.4, 34.3 and 27.5 µM increased in all treated animals (P < 0.05. Lower doses dropped reduced glutathione, catalase and TBARS levels in the hippocampus and striatum. With the exception of this reduction in TBARS formation, FC displayed only in vitro antioxidant activity. Animals exhibited histological alterations suggestive of neurotoxicity and hepatotoxicity, indicating the need for precaution regarding the consumption of medicinal formulations based on Casearia sylvestris.

  19. Electrocautery-induced cavernous nerve injury in rats that mimics radical prostatectomy in humans.

    Science.gov (United States)

    Song, Lu-Jie; Zhu, Jian-Qiang; Xie, Min-Kai; Wang, Yong-Chuan; Li, Hong-Bin; Cui, Zhi-Qiang; Lu, Hong-Kai; Xu, Yue-Min

    2014-07-01

    To investigate the early and delayed effects of cavernous nerve electrocautery injury (CNEI) in a rat model, with the expectation that this model could be used to test rehabilitation therapies for erectile dysfunction (ED) after radical prostatectomy (RP). In all, 30 male Sprague-Dawley rats were randomly divided equally into two groups (15 per group). The control group received CNs exposure surgery only and the experimental group received bilateral CNEI. At 1, 4 and 16 weeks after surgery (five rats at each time point), the ratio of maximal intracavernosal pressure (ICP) to mean arterial pressure (MAP) was measured in the two groups. Neurofilament expression in the dorsal penile nerves was assessed by immunofluorescent staining and Masson's trichrome staining was used to assess the smooth muscle to collagen ratio in both groups. At the 1-week follow-up, the mean ICP/MAP was significantly lower in the CNEI group compared with the control group, at 9.94% vs 70.06% (P 0.05). The smooth muscle to collagen ratio in the CNEI group was significantly lower than in the control group at the 4- and 16-week follow-ups (P corpus cavernosum. This may provide a basis for studying potential preventative measures or treatment strategies to ameliorate ED caused by CNEI during RP. © 2013 The Authors. BJU International © 2013 BJU International.

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

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, Matthieu; Gaugler, Marie-Helene; Rodallec, Audrey; Bonnaud, Stephanie; Paris, Francois [Inserm UMR U892, Centre de Recherche en Cancerologie Nantes-Angers CRCNA, Institut de Recherche Therapeutique IRT-UN, Universite de Nantes, 8 Quai Moncousu, BP 70721, F-44007 (France); Corre, Isabelle, E-mail: icorre@nantes.inserm.fr [Inserm UMR U892, Centre de Recherche en Cancerologie Nantes-Angers CRCNA, Institut de Recherche Therapeutique IRT-UN, Universite de Nantes, 8 Quai Moncousu, BP 70721, F-44007 (France)

    2011-11-04

    Highlights: Black-Right-Pointing-Pointer We explore the role of RhoA in endothelial cell response to ionizing radiation. Black-Right-Pointing-Pointer RhoA is rapidly activated by single high-dose of radiation. Black-Right-Pointing-Pointer Radiation leads to RhoA/ROCK-dependent actin cytoskeleton remodeling. Black-Right-Pointing-Pointer Radiation-induced apoptosis does not require the RhoA/ROCK pathway. Black-Right-Pointing-Pointer 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

  1. Clinical and experimental studies on effects of chemotherapeutic agents on radiation-induced pulmonary damage

    Energy Technology Data Exchange (ETDEWEB)

    Wadasaki, Kouichi

    1988-12-01

    Clinical and experimental studies were undertaken to evaluate the effects of chemotherapeutic agents on radiation-induced pulmonary damage. In a clinical study, one hundred patients with lung cancer were retrospectively reviewed in terms of the development of radiation pneumonitis. In the patients treated with radiation and chemotherapy except for cisplatinum, radiation pneumonitis occurred more frequently and severely than patients with radiation alone. In an experimental study, male SD rats received 15 Gy radiation to the right lungs with or without injection of chemotherapeutic agents including cisplatinum, adriamycin or peplomycin. Histological changes and hydroxyproline contents of the lungs were evaluated at 2 or 5 months after treatment. Pulmonary damage was severer in rats with radiation and drugs than those with radiation alone. However, rats with cisplatinum had less damage than those with other drugs. In conclusion, radiation-induced pulmonary damage was enhanced by administration of several chemotherapeutic agents. However, cisplatinum seemed to enhance pulmonary damage less than other drugs. (author) 77 refs.

  2. 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

  3. Hydroxyl-radical-induced oxidation of cyclic dipeptides: Reactions of free peptide radicals and their peroxyl radicals. Analysis of end products and fast kinetic processes of transient species; Hydroxylradikal-induzierte Oxidation cyclischer Dipeptide: Reaktionen der freien Peptidradikale und ihrer Peroxylradikale. Analyse der Endprodukte und schnelle Kinetik der Transienten

    Energy Technology Data Exchange (ETDEWEB)

    Mieden, O.J.

    1989-12-31

    In the course of this study investigations were carried out into the reactions of hydroxyl radicals and hydrogen atoms with cyclic dipeptides as well as the subsequent reactions of peptide radicals and their peroxyl radicals in aqueous solution. The radiolysis products formed in the absence and presence of oxygen or transient metal complexes were characterized and determined on a quantitative basis. The linking of information from product analyses to the kinetic data for transient species obtained by time-resolving UV/VIS and conductivity measurements (pulse radiolysis) as well as computer-assisted simulations of individual events during the reaction permitted an evaluation of the mechanisms underlying the various processes and an identification of interim products with short life-times, which did or did not belong to the group of radicals. Through the characterization of key reactions of radicals and peroxyl radicals of this substance class a major advance has been made towards a better understanding of the role of radicals in the peptide compound and the mechanisms involved in indirect radiation effects on long-chain peptides and proteins. (orig.). [Deutsch] Im Rahmen dieser Arbeit wurden die Reaktionen von Hydroxyl-Radikalen und Wasserstoff-Atomen mit cyclischen Dipeptiden und die sich daran anschliessenden Reaktionen der Peptiradikale und ihrer Peroxylradikale in waessriger Loesung untersucht. Die Radiolyseprodukte in An- und Abwesenheit von Sauerstoff oder Uebergangsmetallkomplexen wurden charakterisiert und quantitativ bestimmt. Die Kombination der einander ergaenzenden Informationen aus der Produktanalyse und der kinetischen Verfolgung der Transienten durch zeitaufgeloeste UV/VIS- und Leitfaehigkeitsmessungen (Pulsradiolyse) und die rechnergestuetzte Simulation einzelner Teile des Reaktionsverlaufs ermoeglichen eine mechanistische Deutung der verschiedenen Prozesse und die Identifizierung der kurzlebigen radikalischen und nicht-radikalischen Zwischenprodukte

  4. 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.

  5. Exploring the limitations of the Hantzsch method used for quantification of hydroxyl radicals in systems of relevance for interfacial radiation chemistry

    Science.gov (United States)

    Yang, Miao; Soroka, Inna; Jonsson, Mats

    2017-01-01

    In the presence of Tris or methanol, hydroxyl radicals in systems of relevance for interfacial radiation chemistry can be quantified indirectly via the Hantzsch method by determining the amount of the scavenging product formaldehyde formed. In this work, the influence of the presence of H2O2 on the Hantzsch method using acetoacetanilide (AAA) as derivatization reagent is studied. The experiments show that the measured CH2O concentration deviates from the actual concentration in the presence of H2O2 and the deviation increases with increasing [H2O2]0/[CH2O]0. The deviation is negative, i.e., the measured formaldehyde concentration is lower than the actual concentration. This leads to an underestimation of the hydroxyl radical production in systems containing significant amount of H2O2. The main reason for the deviation is found to be three coupled equilibria involving H2O2, CH2O and the derivative produced in the Hantzsch method.

  6. Ionizing radiation induced cataract; Katarakt-Induktion durch ionisierende Strahlung

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, W.U. [Universitaetsklinikum Essen (Germany). Inst. fuer Medizinische Strahlenbiologie

    2013-07-01

    Until recently it was believed that the cataract (opacity of the eye lens) is a deterministic effect with a dose threshold of several Gray in dependence on the exposure conditions. Studies in Hiroshima and Nagasaki, in the vicinity of Chernobyl, of American radiologic technologists, astronauts, and patients after having received several computer tomographies of the head region, however, have shown that this assumption is not correct. It had been overlooked in the past that with decreasing dose the latency period is increasing. Therefore, the originally available studies were terminated too early. The more recent studies show that, in the case of a threshold existing at all, it is definitely below 0.8 Gy independently of an acute or a chronic exposure. All studies, however, include 0 Gy in the confidence interval, so that the absence of a dose threshold cannot be excluded. The German Commission on Radiological Protection (Strahlenschutzkommission, SSK) suggested therefore among others: targeted recording of the lens dose during activities which are known to be associated with possible significant lens exposure, examination of the lens should be included as appropriate in the medical monitoring of people occupationally exposed to radiation, if there is potentially high lens exposure, adoption of research strategies to develop a basic understanding of the mechanisms underlying radiation induced cataracts. The International Commission on Radiological Protection (ICRP) actually assumes a threshold dose of 0.5 Gy and, based on this assumption, has recommended in 2011 to reduce the dose limit for the eye lens from 150 mSv in a year to 20 mSv in a year for people occupationally exposed to ionising radiation. (orig.)

  7. Recovery of human lymphocytes damaged with. gamma. -radiation or enzymatically produced oxygen radicals: different effects of poly(ADP-ribosyl)polymerase inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Marini, M.; Zunica, G. (Ist. di Istologia ed Embriologia Generale, Bologna (Italy)); Tamba, M. (Consiglio Nazionale delle Ricerche, Bologna (Italy). Lab. di Fotochimica e Radiazioni d' Alta Energia); Cossarizza, A.; Monti, D.; Franceschi, C. (Ist. di Patologia Generale, Modena (Italy))

    1990-08-01

    Quiescent human lymphocytes were damaged in two different ways, both producing toxic oxygen radicals: xanthine oxidase plus hypoxanthine (XOD/HYP), or {gamma}-rays. Under conditions where DNA synthesis was reduced to 10-20% of control, inhibitors of poly(ADP-ribosyl)polymerase (ADPRP, an enzyme that becomes activated in the presence of DNA strand breaks) allowed lymphocytes to recover completely when the damage was caused by XOD/HYP, but they did not affect DNA synthesis of irradiated cells. However, a protective effect of ADPRP inhibitors was observed with irradiated lymphocytes receiving doses {ge}50Gy. Unscheduled DNA synthesis was significantly increased when lymphocytes were damaged by high radiation doses in the presence of ADPRP inhibitors. (author).

  8. Radiation induced defects and thermoluminescence mechanism in aluminum oxide

    Energy Technology Data Exchange (ETDEWEB)

    Atobe, K.; Kobayashi, T.; Awata, T. [Naruto Univ. of Education, Tokushima (Japan); Okada, M. [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst; Nakagawa, M. [Kagawa Univ., Faculty of Education, Takamatsu, Kagawa (Japan)

    2001-01-01

    The thermoluminescence of the irradiated aluminum oxides were measured to study the radiation induced defects and their behaviors. Neutron and {gamma}-ray irradiation were performed for a shingle crystal of the high purity aluminum oxide. The thermoluminescence glow curve and its activation energy were measured. The spectroscopy measurement on the thermoluminescence and the absorption are also carried out. The observed 430 and 340 nm peaks are discussed relating to the F{sup +} and F centers, respectively. Activation state of the F center transits to 3P state through 1P state by emitting phonons. Trapped electron on 3P state emits phonon of 2.9 eV (430 nm) during transition to the ground state. The above reaction can be written by the equation. F{sup +} + e {yields} (F){sup *} {yields} F + h{nu}(2.9 eV, 470 nm). (Katsuta, H.)

  9. Invertase immobilization onto radiation-induced graft copolymerized polyethylene pellets

    Science.gov (United States)

    de Queiroz, Alvaro Antonio Alencar; Vitolo, Michele; de Oliveira, Rômulo Cesar; Higa, Olga Zazuco

    1996-06-01

    The graft copolymer poly(ethylene-g-acrylic acid) (LDPE-g-AA) was prepared by radiation-induced graft copolymerization of acrylic acid onto low density polyethylene (LDPE) pellets, and characterized by infrared photoacoustic spectroscopy and scanning electron microscopy (SEM). The presence of the grafted poly(acrylic acid) (PAA) was established. Invertase was immobilized onto the graft polymer and the thermodynamic parameters of the soluble and immobilized enzyme were determined. The Michaelis constant, Km, and the maximum reaction velocity, Vmax, were determined for the free and the immobilized invertase. The Michaelis constant, Km was larger for the immobilized invertase than for the free enzyme, whereas Vmax was smaller for the immobilized invertase. The thermal stability of the immobilized invertase was higher than that of the free enzyme.

  10. Radiation-induced polymerization for the immobilization of penicillin acylase

    Energy Technology Data Exchange (ETDEWEB)

    Boccu, E.; Carenza, M.; Lora, S.; Palma, G.; Veronese, F.M.

    1987-06-01

    The immobilization of Escherichia coli penicillin acylase was investigated by radiation-induced polymerization of 2-hydroxyethyl methacrylate at low temperature. A leak-proof composite that does not swell in water was obtained by adding the cross-linking agent trimethylolpropane trimethacrylate to the monomer-aqueous enzyme mixture. Penicillin acylase, which was immobilized with greater than 70% yield, possessed a higher Km value toward the substrate 6-nitro-3-phenylacetamidobenzoic acid than the free enzyme form (Km = 1.7 X 10(-5) and 1 X 10(-5) M, respectively). The structural stability of immobilized penicillin acylase, as assessed by heat, guanidinium chloride, and pH denaturation profiles, was very similar to that of the free-enzyme form, thus suggesting that penicillin acylase was entrapped in its native state into aqueous free spaces of the polymer matrix.

  11. Radiation induced effects on mechanical properties of nanoporous gold foams

    Energy Technology Data Exchange (ETDEWEB)

    Caro, M., E-mail: magda@lanl.gov, E-mail: efu@pku.edu.cn; Fu, E. G., E-mail: magda@lanl.gov, E-mail: efu@pku.edu.cn; Wang, Y. Q.; Martinez, E.; Caro, A. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Mook, W. M.; Sheehan, C.; Baldwin, J. K. [Center for Integrated Nanotechnology, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-06-09

    It has recently been shown that due to a high surface-to-volume ratio, nanoporous materials display radiation tolerance. The abundance of surfaces, which are perfect sinks for defects, and the relation between ligament size, defect diffusion, and time combine to define a window of radiation resistance [Fu et al., Appl. Phys. Lett. 101, 191607 (2012)]. Outside this window, the dominant defect created by irradiation in Au nanofoams are stacking fault tetrahedra (SFT). Molecular dynamics computer simulations of nanopillars, taken as the elemental constituent of foams, predict that SFTs act as dislocation sources inducing softening, in contrast to the usual behavior in bulk materials, where defects are obstacles to dislocation motion, producing hardening. In this work we test that prediction and answer the question whether irradiation actually hardens or softens a nanofam. Ne ion irradiations of gold nanofoams were performed at room temperature for a total dose up to 4 dpa, and their mechanical behavior was measured by nanoindentation. We find that hardness increases after irradiation, a result that we analyze in terms of the role of SFTs on the deformation mode of foams.

  12. ARE EPIGENETIC MECHANISMS INVOLVED IN RADIATION-INDUCED BYSTANDER EFFECTS?

    Directory of Open Access Journals (Sweden)

    Carmel eMothersill

    2012-05-01

    Full Text Available The non-targeted effects of ionizing radiation including bystander effects and genomic instability are unique in that no classic mutagenic event occurs in the cell showing the effect. In the case of bystander effects, cells which were not in the field affected by the radiation show high levels of mutations, chromosome aberrations and membrane signaling changes leading to what is termed horizontal transmission of mutations and information which may be damaging while in the case of genomic instability, generations of cells derived from an irradiated progenitor appear normal but then lethal and non-lethal mutations appear in distant progeny. This is known as vertical transmission. In both situations high yields of non-clonal mutations leading to distant occurrence of mutation events both in space and time. This precludes a mutator phenotype or other conventional explanation and appear to indicate a generalized form of stress induced mutatgenesis which is well documented in bacteria. This review will discuss the phenomenology of what we term non-targeted effects, and will consider to what extent they challenge conventional ideas in genetics and epigenetics.

  13. Antioxidant Responses Induced by UVB Radiation in Deschampsia antarctica Desv.

    Directory of Open Access Journals (Sweden)

    Hans Köhler

    2017-05-01

    Full Text Available Deschampsia antarctica Desv. is one of two vascular plants that live in the Maritime Antarctic Territory and is exposed to high levels of ultraviolet-B (UVB radiation. In this work, antioxidant physiology of D. antarctica was studied in response to UVB induced oxidative changes. Samples were collected from Antarctica and maintained in vitro culture during 2 years. Plants were sub-cultured in a hydroponic system and exposed to 21.4 kJ m-2 day-1, emulating summer Antarctic conditions. Results showed rapid and significant increases in reactive oxygen species (ROS at 3 h, which rapidly decreased. No dramatic changes were observed in photosynthetic efficiency, chlorophyll content, and level of thiobarbituric acid reactive species (MDA. The enzymatic (superoxide dismutase, SOD and total peroxidases, POD and non-enzymatic antioxidant activity (total phenolic increased significantly in response to UVB treatment. These findings suggest that tolerance of D. antarctica to UVB radiation could be attributed to its ability to activate both enzymatic and non-enzymatic antioxidant systems.

  14. Chromatin Structure and Radiation-Induced Intrachromosome Exchange

    Science.gov (United States)

    Mangala; Zhang, Ye; Hada, Megumi; Cucinotta, Francis A.; Wu, Honglu

    2011-01-01

    We have recently investigated the location of breaks involved in intrachromosomal type exchange events, using the multicolor banding in situ hybridization (mBAND) technique for human chromosome 3. In human epithelial cells exposed to both low- and high-LET radiations in vitro, intrachromosome exchanges were found to occur preferentially between a break in the 3p21 and one in the 3q11. Exchanges were also observed between a break in 3p21 and one in 3q26, but few exchanges were observed between breaks in 3q11 and 3q26, even though the two regions were on the same arm of the chromosome. To explore the relationships between intrachromosome exchanges and chromatin structure, we used probes that hybridize the three regions of 3p21, 3q11 and 3q26, and measured the distance between two of the three regions in interphase cells. We further analyzed fragile sites on the chromosome that have been identified in various types of cancers. Our results demonstrated that the distribution of breaks involved in radiation-induced intrachromosome aberrations depends upon both the location of fragile sites and the folding of chromatins

  15. Development and Validation of Consensus Contouring Guidelines for Adjuvant Radiation Therapy for Bladder Cancer After Radical Cystectomy

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, Brian C. [Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Bosch, Walter R. [Washington University in St. Louis, St. Louis, Missouri (United States); Bahl, Amit [University Hospitals Bristol NHS Foundation Trust, Bristol (United Kingdom); Birtle, Alison J. [Royal Preston Hospital, Preston (United Kingdom); Breau, Rodney H. [University of Ottawa, Ottawa, Ontario (Canada); Challapalli, Amarnath [University Hospitals Bristol NHS Foundation Trust, Bristol (United Kingdom); Chang, Albert J. [University of California San Francisco, San Francisco, California (United States); Choudhury, Ananya [Department of Clinical Oncology, The Christie NHS Foundation Trust, Manchester (United Kingdom); The University of Manchester, Manchester Academic Heath Science Centre, Manchester (United Kingdom); Daneshmand, Sia [University of Southern California, Los Angeles, California (United States); El-Gayed, Ali [Saskatoon Cancer Centre, Saskatoon (Canada); Feldman, Adam [Massachusetts General Hospital, Boston, Massachusetts (United States); Finkelstein, Steven E. [Cancer Treatment Centers of America, Tulsa, Oklahoma (United States); Guzzo, Thomas J. [Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Hilman, Serena [University Hospitals Bristol NHS Foundation Trust, Bristol (United Kingdom); Jani, Ashesh [Emory University, Atlanta, Georgia (United States); Malkowicz, S. Bruce [Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Mantz, Constantine A. [21st Century Oncology, Scottsdale, Arizona (United States); 21st Century Oncology, Fort Myers, Florida (United States); Master, Viraj [Emory University, Atlanta, Georgia (United States); Mitra, Anita V. [University College London Hospital, London (United Kingdom); Murthy, Vedang [Tata Memorial Center, Mumbai (India); and others

    2016-09-01

    Purpose: To develop multi-institutional consensus clinical target volumes (CTVs) and organs at risk (OARs) for male and female bladder cancer patients undergoing adjuvant radiation therapy (RT) in clinical trials. Methods and Materials: We convened a multidisciplinary group of bladder cancer specialists from 15 centers and 5 countries. Six radiation oncologists and 7 urologists participated in the development of the initial contours. The group proposed initial language for the CTVs and OARs, and each radiation oncologist contoured them on computed tomography scans of a male and female cystectomy patient with input from ≥1 urologist. On the basis of the initial contouring, the group updated its CTV and OAR descriptions. The cystectomy bed, the area of greatest controversy, was contoured by another 6 radiation oncologists, and the cystectomy bed contouring language was again updated. To determine whether the revised language produced consistent contours, CTVs and OARs were redrawn by 6 additional radiation oncologists. We evaluated their contours for level of agreement using the Landis-Koch interpretation of the κ statistic. Results: The group proposed that patients at elevated risk for local-regional failure with negative margins should be treated to the pelvic nodes alone (internal/external iliac, distal common iliac, obturator, and presacral), whereas patients with positive margins should be treated to the pelvic nodes and cystectomy bed. Proposed OARs included the rectum, bowel space, bone marrow, and urinary diversion. Consensus language describing the CTVs and OARs was developed and externally validated. The revised instructions were found to produce consistent contours. Conclusions: Consensus descriptions of CTVs and OARs were successfully developed and can be used in clinical trials of adjuvant radiation therapy for bladder cancer.

  16. Bystander effects in radiation-induced genomic instability

    Science.gov (United States)

    Morgan, William F.; Hartmann, Andreas; Limoli, Charles L.; Nagar, Shruti; Ponnaiya, Brian

    2002-01-01

    Exposure of GM10115 hamster-human hybrid cells to X-rays can result in the induction of chromosomal instability in the progeny of surviving cells. This instability manifests as the dynamic production of novel sub-populations of cells with unique cytogenetic rearrangements involving the "marker" human chromosome. We have used the comet assay to investigate whether there was an elevated level of endogenous DNA breaks in chromosomally unstable clones that could provide a source for the chromosomal rearrangements and thus account for the persistent instability observed. Our results indicate no significant difference in comet tail measurement between non-irradiated and radiation-induced chromosomally unstable clones. Using two-color fluorescence in situ hybridization we also investigated whether recombinational events involving the interstitial telomere repeat-like sequences in GM10115 cells were involved at frequencies higher than random processes would otherwise predict. Nine of 11 clones demonstrated a significantly higher than expected involvement of these interstitial telomere repeat-like sequences at the recombination junction between the human and hamster chromosomes. Since elevated levels of endogenous breaks were not detected in unstable clones we propose that epigenetic or bystander effects (BSEs) lead to the activation of recombinational pathways that perpetuate the unstable phenotype. Specifically, we expand upon the hypothesis that radiation induces conditions and/or factors that stimulate the production of reactive oxygen species (ROS). These reactive intermediates then contribute to a chronic pro-oxidant environment that cycles over multiple generations, promoting chromosomal recombination and other phenotypes associated with genomic instability.

  17. Radiation-induced brachial plexus neuropathy in breast cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, N.K.; Pfeiffer, P.; Mondrup, K.; Rose, C. (Odense Univ. Hospital (Denmark). Dept. of Neurology Odense Univ. Hospital (Denmark). Dept. of Clinical Neurophysiology Odense Univ. Hospital (Denmark). Dept. of Oncology R)

    1990-01-01

    The incidence and latency period of radiation-induced brachial plexopathy (RBP) were assessed in 79 breast cancer patients by a neurological follow-up examination at least 60 months (range 67-130 months) after the primary treatment. All patients were treated primarily with simple mastectomy, axillary nodal sampling and radiotherapy (RT). Postoperatively, pre- and postmenopausal patients were randomly allocated chemotherapy for antiestrogen treatment. All patients were recurrence-free at time of examination. Clinically, 35% (25-47%) of the patients had RBP; 19% (11-29%) had definite RBP, i.e. were physically disabled, and 16% (9-26%) had probable RBP. Fifty percent (31-69%) had affection of the entire plexus, 18% (7-35%) of the upper trunk only, and 4% (1-18%) of the lower trunk. In 28% (14-48%) of cases assessment of a definite level was not possible. RBP was more common after radiotherapy and chemotherapy (42%) than after radiotherapy alone (26%) but the difference was not statistically significant (p = 0.10). The incidence of definite RBP was significantly higher in the younger age group (p = 0.02). This could be due to more extensive axillary surgery but also to the fact that chemotherapy was given to most premenopausal patients. In most patients with RBP the symptoms began during or immediately after radiotherapy, and were thus without significant latency. Chemotherapy might enhance the radiation-induced effect on nerve tissue, thus diminishing the latency period. Lymphedema was present in 22% (14-32%), especially in the older patients, and not associated with the development of RBP. In conclusion, the damaging effect of RT on peripheral nerve tissue was documented. Since no successful treatment is available, restricted use of RT to the brachial plexus is warranted, especially when administered concomitantly with cytotoxic therapy. (orig.).

  18. Protective effect of propolis on radiation-induced chromosomal damage on Chinese hamster ovary cells (CHO-K1)

    Energy Technology Data Exchange (ETDEWEB)

    Spigoti, Geyza; Bartolini, Paolo; Okazaki, Kayo [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: kokazaki@ipen.br; Tsutsumi, Shiguetoshi [Amazon Food Ltd., Tokyo (Japan)], e-mail: fwip5138@mb.infoweb.ne.jp

    2009-07-01

    In the last years, particular interest has been given to investigations concerning natural, effective and nontoxic compounds with radioprotective capacity in concert with increasing utilization of different types of ionizing radiation for various applications. Among them, propolis, a resinous mixture of substances collected by honey bees (Apis mellifera) has been considered promising since it presents several advantageous characteristics, i.e., antiinflammatory, anticarcinogenic, antimicrobial and free radical scavenging action. It is, therefore, a direct antioxidant that protects cells and organisms from the adverse effects of ionizing radiation. These relevant biological activities are mainly mediated by the flavonoids, present at relatively high concentrations in the propolis. Considering that the chemical composition and, consequently, the biological activity of propolis is variable according to the environmental plant ecology, the present study was conducted in order to evaluate the radioprotective capacity of Brazilian propolis, collected in the State of Rio Grande do Sul, against genotoxic damages induced by {sup 60}Co {gamma}-radiation in Chinese hamster ovary cells (CHO-K1). for this purpose, micronucleus induction was analyzed concerning irreparable damage, specifically related to DNA double-strand breaks, that are potentially carcinogenic. CHO-K1 cells were submitted to different concentrations of propolis (3 - 33 {mu}g/ml), 1 h before irradiation, with 1 Gy of {gamma} radiation (0.722 Gy/min). The data obtained showed a decreasing tendency in the quantity of radioinduced damage on cells previously treated with propolis. The radioprotective effect was more prominent at higher propolis concentration. The treatment with propolis alone did not induce genotoxic effects on CHO-K1 cells. Beside that, the treatment with propolis, associated or not with radiation, did not influence the kinetics of cellular proliferation. (author)

  19. Effects of Arbutin on Radiation-Induced Micronuclei in Mice Bone Marrow Cells and Its Definite Dose Reduction Factor

    Directory of Open Access Journals (Sweden)

    Saba Nadi

    2016-05-01

    Full Text Available Background: Interactions of free radicals from ionizing radiation with DNA can induce DNA damage and lead to mutagenesis and carsinogenesis. With respect to radiation damage to human, it is important to protect humans from side effects induced by ionizing radiation. In the present study,the effects of arbutin were investigated by using the micronucleus test for anti-clastogenic activity, to calculate the ratio of polychromatic erythrocyte to polychromatic erythrocyte plus normochromatic erythrocyte (PCE/PCE+NCE in order to show cell proliferation activity. Methods: Arbutin (50, 100, and 200 mg/kg was intraperitoneally (ipadministered to NMRI mice two hours before gamma radiation at 2 and 4 gray (Gy. The frequency of micronuclei in 1000 PCEs (MnPCEs and the ratio of PCE/PCE+NCE were calculated for each sample. Data were statistically evaluated using one-way ANOVA,Tukey HSD test, and t-test. Results: The findings indicated that gamma radiation at 2 and 4 Gy extremely increased the frequencies of MnPCE (P<0.001 while reducing PCE/PCE+NCE (P<0.001 compared to the control group. All three doses of arbutin before irradiation significantly reduced the frequencies of MnPCEs and increased the ratio of PCE/PCE+NCE in mice bone marrow compared to the non-drug-treated irradiated control (P<0.001. All three doses of arbutin had no toxicity effect on bone marrow cells. The calculated dose reduction factor (DRF showed DRF=1.93 for 2Gy and DRF=2.22 for 4 Gy. Conclusion: Our results demonstrated that arbutin gives significant protection to rat bone against the clastogenic and cytotoxic effects of gamma irradiation.

  20. Radiation quality dependence of signal transmission and bystander induced cell killing

    Science.gov (United States)

    Esposito, Giuseppe; Bertolotti, Alessia; Facoetti, Angelica; Grande, Sveva; Mariotti, Luca; Ottolenghi, Andrea; Ranza, Elena; Simone, Giustina; Sorrentino, Eugenio; Antonella Tabocchini, Maria

    Low dose radiobiological studies have shown effects, observable in cells that are in the vicinity of irradiated cells, which are due to the release by irradiated cells of several cellular mediators among which Reactive Oxygen and Nitrogen Species (ROS, NRS), and cytokines are likely to play a key role. Despite the large number in the literature of studies on bystander effects induced by ionizing radiation the results are still conflicting, and further studies are therefore needed on the possible underlying mechanisms. The dependence on radiation quality deserve particular attention because bystander mechanisms are probably more important with high-LET irradi-ations, where many cells are not hit (bystander). Moreover, due to the different patterns of energy deposition, the cellular response to low LET and high LET radiation can be different. Understanding whether these cells can contribute to the adverse effects of low radiation doses in a radiation quality-dependent fashion might have important implications in risk estimates for both cancer induction and non-cancer diseases. In this context, we addressed to the study of the bystander induced cell killing after incubation with "conditioned medium" from primary human fibroblasts irradiated with 0.1 and 0.5 Gy of α-particles or γ-rays. Medium transfer was performed after 1h incubation from irradiation. The results have confirmed a reduction in clonogenic survival after incubation with medium from α-irradiated cells, independently of the dose; similar results were obtained after γ-irradiation, although in this case a slight dose depen-dence could be envisaged. Interleukin-6 (IL-6) and Interleukin-8 (IL-8) levels were measured in the conditioned medium collected up to 20 hours after irradiation with α-particles and γ-rays in the dose-range of 0.1-1.0 Gy, in parallel with evaluation of their receptor expression in irradi-ated and bystander cells. Concerning IL-6, we observed the strongest modulation of its release

  1. Blue light induced free radicals from riboflavin in degradation of crystal violet by microbial viability evaluation.

    Science.gov (United States)

    Liang, Ji-Yuan; Yuann, Jeu-Ming P; Hsie, Zong-Jhe; Huang, Shiuh-Tsuen; Chen, Chiing-Chang

    2017-09-01

    Crystal violet (CV) is applied in daily use mainly as a commercial dye and antimicrobial agent. Waste water containing CV may affect aquatic ecosystems. Riboflavin, also known as vitamin B2, is non-toxic and an essential vitamin required for the functions of the human body. Riboflavin is photosensitive to UV and visible light in terms of generating reactive oxygen species. This study investigated the potential application of blue light on riboflavin, so as to come up with an effective way of degrading CV during its treatment. Photosensitivity of CV leading to degradation in the presence of riboflavin was investigated by light intensity, exposure time, and irradiation dosage. The degradation of CV during riboflavin photolysis treatment was studied by a UV/vis spectrometry and chromatography. The effects of CV degradation on microbial viability are relevant when considering the influences on the ecosystem. This study proved that riboflavin photochemical treatment with blue light degrades CV dye by ROS formation. The riboflavin photolysis-treated CV solution appeared to be transparent during conformational transformations of the CV that was rearranged by free radical species generated from riboflavin photolysis. After riboflavin photolysis, colony-forming units (CFUs) were determined for each CV solution. CFU preservation was 85.2% for the CV dissolved riboflavin solution treated with blue light irradiation at 2.0mW/cm2 for 120min. Degradation of CV by riboflavin photochemical procedures can greatly reduce antimicrobial ability and serve as an environmental friendly waste water treatment method. Our results presented here concerning riboflavin photolysis in degradation of CV provide a novel technique, and a simple and safe practice for environmental decontamination processes. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Hyperbaric Oxygen Therapy for Radiation-Induced Cystitis and Proctitis

    Energy Technology Data Exchange (ETDEWEB)

    Oliai, Caspian; Fisher, Brandon; Jani, Ashish; Wong, Michael; Poli, Jaganmohan; Brady, Luther W. [Department of Radiation Oncology, Drexel University College of Medicine, Philadelphia, Pennsylvania (United States); Komarnicky, Lydia T., E-mail: lydia.komarnicky-kocher@drexelmed.edu [Department of Radiation Oncology, Drexel University College of Medicine, Philadelphia, Pennsylvania (United States)

    2012-11-01

    Purpose: To provide a retrospective analysis of the efficacy of hyperbaric oxygen therapy (HBOT) for treating hemorrhagic cystitis (HC) and proctitis secondary to pelvic- and prostate-only radiotherapy. Methods and Materials: Nineteen patients were treated with HBOT for radiation-induced HC and proctitis. The median age at treatment was 66 years (range, 15-84 years). The range of external-beam radiation delivered was 50.0-75.6 Gy. Bleeding must have been refractory to other therapies. Patients received 100% oxygen at 2.0 atmospheres absolute pressure for 90-120 min per treatment in a monoplace chamber. Symptoms were retrospectively scored according to the Late Effects of Normal Tissues-Subjective, Objective, Management, Analytic (LENT-SOMA) scale to evaluate short-term efficacy. Recurrence of hematuria/hematochezia was used to assess long-term efficacy. Results: Four of the 19 patients were lost to follow-up. Fifteen patients were evaluated and received a mean of 29.8 dives: 11 developed HC and 4 proctitis. All patients experienced a reduction in their LENT-SOMA score. After completion of HBOT, the mean LENT-SOMA score was reduced from 0.78 to 0.20 in patients with HC and from 0.66 to 0.26 in patients with proctitis. Median follow-up was 39 months (range, 7-70 months). No cases of hematuria were refractory to HBOT. Complete resolution of hematuria was seen in 81% (n = 9) and partial response in 18% (n = 2). Recurrence of hematuria occurred in 36% (n = 4) after a median of 10 months. Complete resolution of hematochezia was seen in 50% (n = 2), partial response in 25% (n = 1), and refractory bleeding in 25% (n = 1). Conclusions: Hyperbaric oxygen therapy is appropriate for radiation-induced HC once less time-consuming therapies have failed to resolve the bleeding. In these conditions, HBOT is efficacious in the short and long term, with minimal side effects.

  3. Addition of Hyperoxic Component to Adaptation to Hypoxia Prevents Impairments Induced by Low Doses of Toxicants (Free Radical Oxidation and Proteins of HSP Family).

    Science.gov (United States)

    Sazontova, T G; Stryapko, N V; Arkhipenko, Yu V

    2016-01-01

    We studied the possibility of preventing disturbances caused by administration of low doses of toxicants by adaptation to interval hypoxia and hyperoxia. The preventive protective effect of adaptation to hypoxia-hyperoxia manifested in suppression of free radical oxidation, decrease in the levels of HIF-1α and inducible HOx-1, and improvement of tolerance to physical exercises.

  4. Radiation Induced Electrical Current and Voltage in Dielectric Structures

    Science.gov (United States)

    1974-11-22

    1968) Biophysik 4:302. The radiation shielding commninity has-’ext ve dose depth data for homo- geneous materials, and the radiation therapy field has...Bernard, M. (1968) Biophysik 4:302. The radiation shielding community has extensiv’e dose depth data for homo- geneous materials, and the radiation

  5. Prevention of ultraviolet radiation-induced immunosuppression by sunscreen in Candida albicans-induced delayed-type hypersensitivity

    OpenAIRE

    Chen, Quan; LI, RUNXIANG; Zhao, Xiaoxia; LIANG, BIHUA; MA, SHAOYIN; Li, Zhenjie; ZHU, HUILAN

    2016-01-01

    Ultraviolet (UV) radiation-induced immunosuppression leading to skin cancer has received increased attention in previous years. The present study aimed to investigate the immunoprotection offered by Anthelios sunscreen in a mouse model of Candida albicans-induced delayed-type hypersensitivity. Anthelios sunscreen was applied to the skin on the dorsal skin of BALB/c mice treated with a sub-erythema dose of solar-simulated radiation. Delayed-type hypersensitivity was induced by immunization wit...

  6. Pretreatment of low dose radiation reduces radiation-induced apoptosis in mouse lymphoma (EL4) cells.

    Science.gov (United States)

    Kim, J H; Hyun, S J; Yoon, M Y; Ji, Y H; Cho, C K; Yoo, S Y

    1997-06-01

    Induction of an adaptive response to ionizing radiation in mouse lymphoma (EL4) cells was studied by using cell survival fraction and apoptotic nucleosomal DNA fragmentation as biological end points. Cells in early log phase were pre-exposed to low dose of gamma-rays (0.01 Gy) 4 or 20 hrs prior to high dose gamma-ray (4, 8 and 12 Gy for cell survival fraction analysis; 8 Gy for DNA fragmentation analysis) irradiation. Then cell survival fractions and the extent of DNA fragmentation were measured. Significant adaptive response, increase in cell survival fraction and decrease in the extent of DNA fragmentation were induced when low and high dose gamma-ray irradiation time interval was 4 hr. Addition of protein or RNA synthesis inhibitor, cycloheximide or 5,6-dichloro-1-beta-d-ribofuranosylbenzimidazole (DRFB), respectively during adaptation period, the period from low dose gamma-ray irradiation to high dose gamma-ray irradiation, was able to inhibit the induction of adaptive response, which is the reduction of the extent DNA fragmentation in irradiated EL4 cells. These data suggest that the induction of adaptive response to ionizing radiation in EL4 cells required both protein and RNA synthesis.

  7. A Rare Case of Radiation-Induced Osteosarcoma of the Ethmoid Sinus

    Directory of Open Access Journals (Sweden)

    Musaed Alzahrani

    2011-01-01

    Full Text Available Radiation therapy has been recognized as a useful modality of treatment in head and neck malignant tumors. However, radiation over 10 Gy may predispose to secondary tumors. Radiation-induced osteosarcoma of the ethmoid sinus is unusual. These tumors may present long after radiation with epistaxis. Computed tomography, magnetic resonance imaging, and biopsy are the modalities of diagnosis. We report a case of radiation-induced osteosarcoma of the ethmoid sinus 9 years after initial exposure. We describe the clinical presentation, the radiological findings, and the management.

  8. The effect of radiation dose on the onset and progression of radiation-induced brain necrosis in the rat model.

    Science.gov (United States)

    Hartl, Brad A; Ma, Htet S W; Hansen, Katherine S; Perks, Julian; Kent, Michael S; Fragoso, Ruben C; Marcu, Laura

    2017-07-01

    To provide a comprehensive understanding of how the selection of radiation dose affects the temporal and spatial progression of radiation-induced necrosis in the rat model. Necrosis was induced with a single fraction of radiation exposure, at doses ranging between 20 and 60 Gy, to the right hemisphere of 8-week-old Fischer rats from a linear accelerator. The development and progression of necrosis in the rats was monitored and quantified every other week with T1- and T2-weighted gadolinium contrast-enhanced MRI studies. The time to onset of necrosis was found to be dose-dependent, but after the initial onset, the necrosis progression rate and total volume generated was constant across different doses ranging between 30 and 60 Gy. Radiation doses less than 30 Gy did not develop necrosis within 33 weeks after treatment, indicating a dose threshold existing between 20 and 30 Gy. The highest dose used in this study led to the shortest time to onset of radiation-induced necrosis, while producing comparable disease progression dynamics after the onset. Therefore, for the radiation-induced necrosis rat model using a linear accelerator, the most optimum results were generated from a dose of 60 Gy.

  9. A novel radiation-induced p53 mutation is not implicated in radiation resistance via a dominant-negative effect.

    Directory of Open Access Journals (Sweden)

    Yunguang Sun

    Full Text Available Understanding the mutations that confer radiation resistance is crucial to developing mechanisms to subvert this resistance. Here we describe the creation of a radiation resistant cell line and characterization of a novel p53 mutation. Treatment with 20 Gy radiation was used to induce mutations in the H460 lung cancer cell line; radiation resistance was confirmed by clonogenic assay. Limited sequencing was performed on the resistant cells created and compared to the parent cell line, leading to the identification of a novel mutation (del at the end of the DNA binding domain of p53. Levels of p53, phospho-p53, p21, total caspase 3 and cleaved caspase 3 in radiation resistant cells and the radiation susceptible (parent line were compared, all of which were found to be similar. These patterns held true after analysis of p53 overexpression in H460 cells; however, H1299 cells transfected with mutant p53 did not express p21, whereas those given WT p53 produced a significant amount, as expected. A luciferase assay demonstrated the inability of mutant p53 to bind its consensus elements. An MTS assay using H460 and H1299 cells transfected with WT or mutant p53 showed that the novel mutation did not improve cell survival. In summary, functional characterization of a radiation-induced p53 mutation in the H460 lung cancer cell line does not implicate it in the development of radiation resistance.

  10. Free radical scavenging reverses fructose-induced salt-sensitive hypertension

    Directory of Open Access Journals (Sweden)

    Zenner ZP

    2017-12-01

    Full Text Available Zachary P Zenner, Kevin L Gordish, William H Beierwaltes Department of Internal Medicine, Hypertension and Vascular Research Division, Henry Ford Hospital, Detroit, MI, USA Abstract: We have previously reported that a moderate dietary supplementation of 20% fructose but not glucose leads to a salt-sensitive hypertension related to increased proximal sodium–hydrogen exchanger activity and increased renal sodium retention. We also found that while high salt increased renal nitric oxide formation, this was retarded in the presence of fructose intake. We hypothesized that at least part of the pathway leading to fructose-induced salt-sensitive hypertension could be due to fructose-induced formation of reactive oxygen species and inappropriate stimulation of renin secretion, all of which would contribute to an increase in blood pressure. We found that both 20% fructose intake and a high-salt diet stimulated 8-isoprostane excretion. The superoxide dismutase (SOD mimetic tempol significantly reduced this elevated excretion. Next, we placed rats on a high-salt diet (4% for 1 week in combination with normal rat chow or 20% fructose with or without chronic tempol administration. A fructose plus high-salt diet induced a rapid increase (15 mmHg in systolic blood pressure and reversed high salt suppression of plasma renin activity. Tempol treatment reversed the pressor response and restored high salt suppression of renin. We conclude that fructose-induced salt-sensitive hypertension is driven by increased renal reactive oxygen species formation associated with salt retention and an enhanced renin–angiotensin system. Keywords: reactive oxygen species, tempol, sodium, renin, oxidative stress

  11. Studies on the radiation induced apoptosis by morphological and biochemical analysis in A431 cells

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Keun Hee [Dong Shin College, Kwangju (Korea, Republic of); Bom, Hee Seung; Kim, Ji Yeul [College of Medicine, Chonnam National Univ., Kwangju (Korea, Republic of)

    1999-02-01

    We performed this study to evaluate the process of radiation induced apoptosis in A431 skin epithelial cancer cell line. Low to high dose radiation (0, 2, 5, 10, 25 Gy) was given to A431 cells by Cs-137 cell irradiator. Apoptosis was evaluated by cell morphology, dye exclusion test, and DNA laddering. Cell viability decreased as the radiation dose increased. Number of apoptotic bodies increased as radiation dose increased. It increased most significantly at 12 hours after irradiation. Lactate dehydrogenase activity in culture medium increased according to radiation dose and time after irradiation. DNA ladders could be identified in irradiated cells, but, it had no correlation with radiation dose or time after irradiation. Radiation-induced apoptosis which was the main course of cell death in A431 cells could be analyzed quantitatively by counting apoptotic bodies under microscope. Apoptosis increased as radiation dose increased.

  12. Low-level laser therapy in chemo- and radiation-induced mucositis: results of multicenter phase III studies

    Science.gov (United States)

    Bensadoun, Rene-Jean

    2001-04-01

    Low of middle energy irradiation with helium-neon laser (LLLT) appears to be a simple atraumatic technique for the prevention and treatment of mucositis of various origins. Preliminary findings obtained by Ciais et al prompted randomized multi-center, double-blind trials to evaluate LLLT for the prevention of a acute chemo- and radiation- induced stomatitis. Irradiation by LLLT corresponds to local application of a high photon density monochromatic light source. Activation of epithelial healing on LLL-treated surfaces, the most commonly recognized effect, has been confirmed by numerous in vitro studies, and is a function of cell type, wavelength, and energy dose. The mechanism of action at a molecular and enzymatic level is currently being studied (detoxification of free-radicals).

  13. DETECTION OF LOW DOSE RADIATION INDUCED DNA DAMAGE USING TEMPERATURE DIFFERENNTIAL FLUORESENCE ASSAY

    Science.gov (United States)

    A rapid and sensitive fluorescence assay for radiation-induced DNA damage is reported. Changes in temperature-induced strand separation in both calf thymus DNA and plasmid DNA (puc 19 plasmid from Escherichia coli) were measured after exposure to low doses of radiation. Exposures...

  14. DETECTION OF LOW DOSE RADIATION INDUCED DNA DAMAGE USING TEMPERATURE DIFFERENTIAL FLUORESCENCE ASSAY

    Science.gov (United States)

    A rapid and sensitive fluorescence assay for radiation-induced DNA damage is reported. Changes in temperature-induced strand separation in both calf thymus DNA and plasmid DNA (puc 19 plasmid from Escherichia coli) were measured after exposure to low doses of radiation. Exposur...

  15. Radiation-induced breast cancer incidence and mortality from digital mammography screening a modeling study

    NARCIS (Netherlands)

    D.L. Miglioretti (Diana); J. Lange (Jane); J.J. Van Den Broek (Jeroen J.); C.I. Lee (Christoph I.); N.T. van Ravesteyn (Nicolien); D. Ritley (Dominique); K. Kerlikowske (Karla); J.J. Fenton (Joshua J.); J. Melnikow (Joy); H.J. de Koning (Harry); R.A. Hubbard (Rebecca)

    2016-01-01

    textabstractBackground: 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. Objective: To estimate distributions of radiation-induced breast cancer incidence and

  16. Atorvastatin mitigates testicular injuries induced by ionizing radiation in mice.

    Science.gov (United States)

    Naeimi, Ramezan Ali; Talebpour Amiri, Fereshteh; Khalatbary, Ali Reza; Ghasemi, Arash; Zargari, Mehryar; Ghesemi, Maryam; Hosseinimehr, Seyed Jalal

    2017-09-01

    Radiotherapy in patients with pelvis malignancy causes testes irradiation and resulted in testicular damages. Atorvastatin (ATV) in the low-dose is considered as antioxidant and anti-inflammatory properties. This experimental study was investigated protective effects of ATV on irradiation-induced testicular injury. Sixty male balb/c mice were randomly divided into 6 groups: 1: control, 2: irradiated (IR), 3, 4 and 5: IR plus ATV (10, 20 and 50mg/kg), 6: only ATV (50mg/kg). The ATV treated groups were received ATV for 7days via oral gavage before IR. Irradiated groups exposed to 2Gy whole body X-ray on day 8. Biochemical, histological and immunohistological parameters were evaluated for radioprotective effect of ATV. In the ATV pretreatment in irradiated mice, MDA levels were significantly decreased compared with the IR group. The effect of all three doses of ATV caused reduced MDA level, but ATV to dose of 50mg/kg had more effect than other doses of ATV. Significant decrease in the concentration of testosterone was observed in only irradiated mice compared with the ATV plus irradiated. In addition, the histological examination showed Johnsen Score in the IR group was lower compared to ATV pretreated groups. ATV significantly reduced caspase-3 immunoreactivity induced by irradiation. The results from this study suggest that ATV at low dose has a protective effect against irradiation-induced testicular damage. This result provides a new indication of ATV for protection of testis during radiation therapy in treatment of cancer patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Effects of subdiaphragmatic vagotomy on the acquisition of a radiation-induced conditioned taste aversion

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-01-01

    The effect of subdiaphragmatic vagotomy on the acquisition of a radiation-induced taste aversion was examined to assess the importance of the vagus nerve in transmitting information on the peripheral toxicity of radiation to the brain. Vagotomy had no effect on taste aversion learning, consistent with reports using other toxins. The data support the involvement of a blood-borne factor in the acquisition of taste aversion induced by ionizing radiation.

  18. Theoretical and experimental radiation effectiveness of the free radical dosimeter alanine to irradiation with heavy charged particles

    DEFF Research Database (Denmark)

    Hansen, Jørgen-Walther; Olsen, K. J.

    1985-01-01

    -LET radiations of 60Co .gamma. rays, 4 and 16 MV X rays, and 6, 10, and 20 MeV electrons was compared with theoretical RE values derived from a model based on track structure theory of heavy charged particles. The ion beams covered a range in initial LET of 27-20,200 MeVcm2/g, and the experimental RE decreased...

  19. Apoptosis induced by ultraviolet radiation is enhanced by amplitude modulated radiofrequency radiation in mutant yeast cells.

    Science.gov (United States)

    Markkanen, Ari; Penttinen, Piia; Naarala, Jonne; Pelkonen, Jukka; Sihvonen, Ari-Pekka; Juutilainen, Jukka

    2004-02-01

    The aim of this study was to investigate whether radiofrequency (RF) electromagnetic field (EMF) exposure affects cell death processes of yeast cells. Saccharomyces cerevisiae yeast cells of the strains KFy417 (wild-type) and KFy437 (cdc48-mutant) were exposed to 900 or 872 MHz RF fields, with or without exposure to ultraviolet (UV) radiation, and incubated simultaneously with elevated temperature (+37 degrees C) to induce apoptosis in the cdc48-mutated strain. The RF exposure was carried out in a special waveguide exposure chamber where the temperature of the cell cultures can be precisely controlled. Apoptosis was analyzed using the annexin V-FITC method utilizing flow cytometry. Amplitude modulated (217 pulses per second) RF exposure significantly enhanced UV induced apoptosis in cdc48-mutated cells, but no effect was observed in cells exposed to unmodulated fields at identical time-average specfic absorption rates (SAR, 0.4 or 3.0 W/kg). The findings suggest that amplitude modulated RF fields, together with known damaging agents, can affect the cell death process in mutated yeast cells. Bioelectromagnetics 25:127-133, 2004. Copyright 2004 Wiley-Liss, Inc.

  20. Radiation induced oxidation of sulphydryl molecules in aqueous solutions. A comprehensive review

    Science.gov (United States)

    Lal, Manohar

    1994-06-01

    Radiation degradation studies of thiols in aqueous solutions under variety of conditions during the past more than three decades are reviewed. Radiolytic mechanism of γ-irradiated air free, air and N 2O-saturated solutions of cysteine, cysteamine, dithiothreitol, mercaptoethanol, glutathione and papain are high lighted. A large variety of thiols repair organic radicals by H atom transfer from SH group. The repair rate constants are found to be between 5 × 10 6M -1s -1 to 4.0 × 10 8M -1s -1. The data are tabulated. The rate constants of e -aq and ȮH radicals with variety of thiols evaluated by pulse radioanalysis and flash photolysis are found to be very high and are computed. Sulphur centered radicals e.g. RṠ;, RSSR ⨪ generated in the pulse radioanalysis of thiols are very important species. Their reactions with oxygen and other compounds are of relevance to radiation biology. The results, reaction mechanism, the repair rate constant, the rate constants of e -aq and ȮH radicals with thiols and the rate constants of sulphur centered radicals with oxygen and other compounds of biological interest can be of great use in the interpretation of the mechanism of the protection of cells, animals, DNA and other biological molecules and may well provide basic essential information for the understanding of radiation biology. The protection of biological target at chemical level is generally understood in terms of protecting compounds participating directly in the radiochemical event and reducing the damage to biological target. The damage to the biological target is repaired by the hydrogen transfer from the thiol. Biochemical and metabolic mechanisms are quite complex. There is no single mechanism which explains all the experimental observations on the metabolism of thiols. More work needs to be done in order to understand the metabolic aspect of the protection mechanism.

  1. Effects of melanin-induced free radicals on the isolated rat peritoneal mast cells

    Energy Technology Data Exchange (ETDEWEB)

    Ranadive, N.S.; Shirwadkar, S.; Persad, S.; Menon, I.A.

    1986-03-01

    Pheomelanin from human red hair (RHM) produces considerably more cellular damage in Ehrlich ascites carcinoma cells when subjected to radiations of wavelength 320-700 nm than eumelanin from black hair (BHM). Irradiation of RHM generated large amounts of superoxide while BHM did not produce detectable amounts of superoxide. The present investigations describe the effects of irradiation of mast cells in the presence of various natural and synthetic melanins. Irradiation of mast cells in the presence of RHM and red hair melanoprotein released large amounts of histamine while BHM and synthetic melanins prepared from dopa, cysteinyldopa, or a mixture of dopa and cysteinyldopa did not release histamine. The release of histamine at lower concentrations of RHM was not accompanied by the release of /sup 51/Cr from chromium-loaded cells, suggesting that this release was of noncytotoxic nature. On the other hand, the release of histamine at higher concentrations of RHM was due to cell lysis since both histamine and cytoplasmic marker /sup 51/Cr were released to the same extent. The release evoked by large concentration RHM was not inhibited by superoxide dismutase or catalase. This suggests that the cell lysis under these conditions was not due to H/sub 2/O/sub 2/ or O-2. The finding that mast cells release histamine when irradiated in the presence of RHM suggests that the immediate and late-phase reactions seen in sunburn may in part be due to the release of mediators from these cells.

  2. Radiation-Induced Topological Disorder in Irradiated Network Structures

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, Linn W.

    2002-12-21

    This report summarizes results of a research program investigating the fundamental principles underlying the phenomenon of topological disordering in a radiation environment. This phenomenon is known popularly as amorphization, but is more formally described as a process of radiation-induced structural arrangement that leads in crystals to loss of long-range translational and orientational correlations and in glasses to analogous alteration of connectivity topologies. The program focus has been on a set compound ceramic solids with directed bonding exhibiting structures that can be described as networks. Such solids include SiO2, Si3N4, SiC, which are of interest to applications in fusion energy production, nuclear waste storage, and device manufacture involving ion implantation or use in radiation fields. The principal investigative tools comprise a combination of experimental diffraction-based techniques, topological modeling, and molecular-dynamics simulations that have proven a rich source of information in the preceding support period. The results from the present support period fall into three task areas. The first comprises enumeration of the rigidity constraints applying to (1) more complex ceramic structures (such as rutile, corundum, spinel and olivine structures) that exhibit multiply polytopic coordination units or multiple modes of connecting such units, (2) elemental solids (such as graphite, silicon and diamond) for which a correct choice of polytope is necessary to achieve correct representation of the constraints, and (3) compounds (such as spinel and silicon carbide) that exhibit chemical disorder on one or several sublattices. With correct identification of the topological constraints, a unique correlation is shown to exist between constraint and amorphizability which demonstrates that amorphization occurs at a critical constraint loss. The second task involves the application of molecular dynamics (MD) methods to topologically-generated models

  3. Is brain copper deficiency in Alzheimer's, Lewy body, and Creutzfeldt Jakob diseases the common key for a free radical mechanism and oxidative stress-induced damage?

    Science.gov (United States)

    Deloncle, Roger; Guillard, Olivier

    2015-01-01

    In Alzheimer's (AD), Lewy body (LBD), and Creutzfeldt Jakob (CJD) diseases, similar pathological hallmarks have been described, one of which is brain deposition of abnormal protease-resistant proteins. For these pathologies, copper bound to proteins is able to protect against free radicals by reduction from cupric Cu++ to cupreous Cu+. We have previously demonstrated in bovine brain homogenate that free radicals produce proteinase K-resistant prion after manganese is substituted for copper. Since low brain copper levels have been described in transmissible spongiform encephalopathies, in substantia nigra in Parkinson's disease, and in various brain regions in AD, LBD, and CJD, a mechanism has been proposed that may underlie the neurodegenerative processes that occur when copper protection against free radicals is impaired. In peptide sequences, the alpha acid proton near the peptide bond is highly mobile and can be pulled out by free radicals. It will produce a trivalent α-carbon radical and induce a free radical chain process that will generate a D-amino acid configuration in the peptide sequence. Since only L-amino acids are physiologically present in mammalian (human) proteins, it may be supposed that only physiological L-peptides can be recycled by physiological enzymes such as proteases. If a D-amino acid is found in the peptide sequence subsequent to deficient copper protection against free radicals, it will not be recognized and might alter the proteasome L-amino acid recycling from brain peptides. In the brain, there will result an accumulation of abnormal protease-resistant proteins such as those observed in AD, LBD, and CJD.

  4. Atmospheric-pressure plasma jet induces apoptosis involving mitochondria via generation of free radicals.

    Directory of Open Access Journals (Sweden)

    Hak Jun Ahn

    Full Text Available The plasma jet has been proposed as a novel therapeutic method for anticancer treatment. However, its biological effects and mechanism of action remain elusive. Here, we investigated its cell death effects and underlying molecular mechanisms, using air and N₂ plasma jets from a micro nozzle array. Treatment with air or N₂ plasma jets caused apoptotic death in human cervical cancer HeLa cells, simultaneously with depolarization of mitochondrial membrane potential. In addition, the plasma jets were able to generate reactive oxygen species (ROS, which function as surrogate apoptotic signals by targeting the mitochondrial membrane potential. Antioxidants or caspase inhibitors ameliorated the apoptotic cell death induced by the air and N₂ plasma jets, suggesting that the plasma jet may generate ROS as a proapoptotic cue, thus initiating mitochondria-mediated apoptosis. Taken together, our data suggest the potential employment of plasma jets as a novel therapy for cancer.

  5. Long-term results of endosteal implants following radical oral cancer surgery with and without adjuvant radiation therapy.

    Science.gov (United States)

    Linsen, Sabine S; Martini, Markus; Stark, Helmut

    2012-04-01

    The aim of this study was to analyze the long-term survival of implants and implant-retained prostheses in patients after ablative surgery of oral cancer with or without adjunctive radiation therapy. Between 1997 and 2008, 66 patients who had undergone ablative tumor surgery in the oral cavity were treated with dental implants (n = 262). Thirty-four patients received radiation therapy in daily fractions of 2 Gy administered on 18 to 30 days. Implants were inserted in the maxilla (49; 18.7%) or mandible (213; 81.3%), in non-irradiated residual (65; 24.8%) or grafted bone (44; 16.8%) and in irradiated residual (15.6%) or grafted bone (39; 14.9%). Seventeen fixed protheses and 53 removable dentures (34 bar attachments, 9 telescopic and 10 ball retained dentures) were inserted. Mean follow-up after implant insertion was 47.99 (±34.31) months (range 12-140 months). The overall 1-, 5-, and 10-year survival rates of all implants were 96.6%, 96.6%, and 86.9%, respectively. Fourteen implants were lost in nine patients (5.3% of all implants); eight implants were primary losses, and five secondary losses because of an operation of tumor recurrence. There was no significantly lower implant survival for implants inserted into irradiated bone (p = .302), bone and/or soft-tissue grafts (p = .436), and maxilla or mandible (p = .563). All prosthetic restorations in patients without tumor recurrence could be maintained during the observation period. Implant survival is not significantly influenced by radiation therapy, grafts (bone and/or soft tissue), or location (maxilla or mandible). However, implants placed in irradiated bone exhibit a higher failure rate during the healing period than those placed in non-irradiated bone. No superstructure was particularly favorable. Osseointegrated implants can be used successfully in patients with prior history of ablative surgery with and without additional radiation therapy. © 2009 Wiley Periodicals, Inc.

  6. Patterns of failure after radical prostatectomy in prostate cancer - implications for radiation therapy planning after {sup 68}Ga-PSMA-PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Schiller, Kilian; Sauter, K.; Dewes, S. [Technical University of Munich (TUM), Department of Radiation Oncology, Munich (Germany); Eiber, M. [Technical University Munich (TUM), Department of Nuclear Medicine, Munich (Germany); David Geffen School of Medicine at UCLA, Department of Molecular and Medical Pharmacology, Los Angeles, CA (United States); Maurer, T.; Gschwend, J. [Technical University Munich (TUM), Department of Urology, Munich (Germany); Combs, S.E.; Habl, G. [Technical University of Munich (TUM), Department of Radiation Oncology, Munich (Germany); Institute of Innovative Radiotherapy (iRT), Helmholtz Zentrum Muenchen, Department of Radiation Sciences (DRS), Munich (Germany)

    2017-09-15

    Salvage radiotherapy (SRT) after radical prostatectomy (RPE) and lymphadenectomy (LAE) is the appropriate radiotherapy option for patients with persistent/ recurrent prostate cancer (PC). {sup 68}Ga-PSMA-PET imaging has been shown to accurately detect PC lesions in a primary setting as well as for local recurrence or for lymph node (LN) metastases. In this study we evaluated the patterns of recurrence after RPE in patients with PC, putting a highlight on the differentiation between sites that would have been covered by a standard radiation therapy (RT) field in consensus after the RTOG consensus and others that would have not. Thirty-one out of 83 patients (37%) with high-risk PC were the subject of our study. Information from {sup 68}Ga-PSMA-PET imaging was used to individualize treatment plans to include suspicious lesions as well as possibly boost sites with tracer uptake in LN or the prostate bed. For evaluation, {sup 68}Ga-PSMA-PET-positive LN were contoured in a patient dataset with a standard lymph drainage (RTOG consensus on CTV definition of pelvic lymph nodes) radiation field depicting color-coded nodes that would have been infield or outfield of that standard lymph drainage field and thereby visualizing typical patterns of failure of a ''blind'' radiation therapy after RPE and LAE. Compared to negative conventional imaging (CT/MRI), lesions suspicious for PC were detected in 27/31 cases (87.1%) by {sup 68}Ga-PSMA-PET imaging, which resulted in changes to the radiation concept. There were 16/31 patients (51.6%) that received a simultaneous integrated boost (SIB) to a subarea of the prostate bed (in only three cases this dose escalation would have been planned without the additional knowledge of {sup 68}Ga-PSMA-PET imaging) and 18/31 (58.1%) to uncommon (namely presacral, paravesical, pararectal, preacetabular and obturatoric) LN sites. Furthermore, 14 patients (45.2%) had a changed TNM staging result by means of {sup 68}Ga

  7. Reactions of nitroxide radicals in aqueous solutions exposed to non-thermal plasma: limitations of spin trapping of the plasma induced species

    Science.gov (United States)

    Gorbanev, Yury; Stehling, Nicola; O'Connell, Deborah; Chechik, Victor

    2016-10-01

    Low temperature (‘cold’) atmospheric pressure plasmas have gained much attention in recent years due to their biomedical effects achieved through the interactions of plasma-induced species with the biological substrate. Monitoring of the radical species in an aqueous biological milieu is usually performed via electron paramagnetic resonance (EPR) spectroscopy using various nitrone spin traps, which form persistent radical adducts with the short-lived radicals. However, the stability of these nitroxide radical adducts in the plasma-specific environment is not well known. In this work, chemical transformations of nitroxide radicals in aqueous solutions using a model nitroxide 4-oxo-TEMPO were studied using EPR and LC-MS. The kinetics of the nitroxide decay when the solution was exposed to plasma were assessed, and the reactive pathways proposed. The use of different scavengers enabled identification of the types of reactive species which cause the decay, indicating the predominant nitroxide group reduction in oxygen-free plasmas. The 2H adduct of the PBN spin trap (PBN-D) was shown to decay similarly to the model molecule 4-oxo-TEMPO. The decay of the spin adducts in plasma-treated solutions must be considered to avoid rendering the spin trapping results unreliable. In particular, the selectivity of the decay indicated the limitations of the PTIO/PTI nitroxide system in the detection of nitric oxide.

  8. 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.

  9. Radical radiotherapy of localised prostate cancer: the relationship between radiation dose and survival; La radiotherapie radicale de l`adenocarcinome de la prostate localise: relation entre la dose et la survie

    Energy Technology Data Exchange (ETDEWEB)

    Magrini, S.M.; Cellai, E.; Pertici, M.; Rossi, F.; Cappellini, M.; Biti, G.P. [University Hospital of Florence (Italy); Ponticelli, P.; Odantini, R. [S Donato Hospital, Arezzo (Italy)

    1998-07-01

    This retrospective study aims to define the effects of different radiation dose levels on survival, local control and toxicity in a series of 208 patients with localised prostate cancer consecutively treated with radical radiation therapy. The results of this retrospective analysis confirm the good results of small volume, high dose radiation therapy of prostatic cancer, even taking into account the possible biases due to the retrospective nature of the study, and the relevance of the PSA level at diagnosis to define the risk of local failure. (authors)

  10. Radiation induced redox reactions and fragmentation of constituent ions in ionic liquids. I. Anions.

    Energy Technology Data Exchange (ETDEWEB)

    Shkrob, I. A.; Marin, T.; Chemerisov, S.; Wishart, J. (Chemical Sciences and Engineering Division); (BNL); (Benedictine Univ.)

    2011-04-14

    Room temperature ionic liquids (IL) find increasing use for the replacement of organic solvents in practical applications, including their use in solar cells and electrolytes for metal deposition, and as extraction solvents for the reprocessing of spent nuclear fuel. The radiation stability of ILs is an important concern for some of these applications, as previous studies suggested extensive fragmentation of the constituent ions upon irradiation. In the present study, electron paramagnetic resonance (EPR) spectroscopy has been used to identify fragmentation pathways for constituent anions in ammonium, phosphonium, and imidazolium ILs. Many of these detrimental reactions are initiated by radiation-induced redox processes involving these anions. Scission of the oxidized anions is the main fragmentation pathway for the majority of the practically important anions; (internal) proton transfer involving the aliphatic arms of these anions is a competing reaction. For perfluorinated anions, fluoride loss following dissociative electron attachment to the anion can be even more prominent than this oxidative fragmentation. Bond scission in the anion was also observed for NO{sub 3}{sup -} and B(CN){sub 4}{sup -} anions and indirectly implicated for BF{sub 4}{sup -} and PF{sub 6}{sup -} anions. Among small anions, CF{sub 3}SO{sub 3}{sup -} and N(CN){sub 2}{sup -} are the most stable. Among larger anions, the derivatives of benzoate and imide anions were found to be relatively stable. This stability is due to suppression of the oxidative fragmentation. For benzoates, this is a consequence of the extensive sharing of unpaired electron density by the {pi}-system in the corresponding neutral radical; for the imides, this stability could be the consequence of N-N {sigma}{sup 2}{sigma}*{sup 1} bond formation involving the parent anion. While fragmentation does not occur for these 'exceptional' anions, H atom addition and electron attachment are prominent. Among the

  11. Silibinin attenuates radiation-induced intestinal fibrosis and reverses epithelial-to-mesenchymal transition.

    Science.gov (United States)

    Kim, Joong Sun; Han, Na-Kyung; Kim, Sung-Ho; Lee, Hae-June

    2017-09-19

    Radiotherapy is a common treatment for cancer patients, but its use is often restricted by the tolerance of normal tissue. As cancer patients live longer, delayed radiation effects on normal tissue have become a concern. Radiation-induced enteropathy, including inflammatory bowel disease and fibrosis, are major issues for long-term cancer survivors. To investigate whether silibinin attenuates delayed radiation-induced intestinal injury in mice, we focused on intestinal fibrotic changes. Silibinin improved delayed radiation injuries in mice in association with decreased collagen deposition within the intestines and deceased transforming growth factor (TGF)-β1 levels in the intestine and plasma. Treating mice bearing CT26 mouse colon cancer tumors with both silibinin and radiation stimulated tumor regression more than radiation alone. We also investigated the effect of silibinin on the radiation-induced epithelial-to-mesenchymal transition (EMT), the primary mechanism of fibrosis. We assessed changes in E-cadherin, N-cadherin, and α-smooth muscle actin expression, and demonstrated that silibinin attenuates radiation-induced EMT. Irradiating intestinal epithelial cells increased TGF-β1 levels, but silibinin suppressed TGF-β1 expression by inhibiting Smad2/3 phosphorylation. These results suggest silibinin has the potential to serve as a useful therapeutic agent in patients with radiation-induced intestinal fibrosis.

  12. Influence of free radicals signal from dental resins on the radio-induced signal in teeth in EPR retrospective dosimetry.

    Science.gov (United States)

    Levêque, Philippe; Desmet, Céline; Dos Santos-Goncalvez, Ana Maria; Beun, Sébastien; Leprince, Julian G; Leloup, Gaëtane; Gallez, Bernard

    2013-01-01

    In case of radiological accident, retrospective dosimetry is needed to reconstruct the absorbed dose of overexposed individuals not wearing personal dosimeters at the onset of the incident. In such a situation, emergency mass triage will be required. In this context, it has been shown that Electron Paramagnetic Resonance (EPR) spectroscopy would be a rapid and sensitive method, on the field deployable system, allowing dose evaluation of a great number of people in a short time period. This methodology uses tooth enamel as a natural dosimeter. Ionising radiations create stable free radicals in the enamel, in a dose dependent manner, which can be detected by EPR directly in the mouth with an appropriate resonator. Teeth are often subject to restorations, currently made of synthetic dimethacrylate-based photopolymerizable composites. It is known that some dental composites give an EPR signal which is likely to interfere with the dosimetric signal from the enamel. So far, no information was available about the occurrence of this signal in the various composites available on the market, the magnitude of the signal compared to the dosimetric signal, nor its evolution with time. In this study, we conducted a systematic characterization of the signal (intensity, kinetics, interference with dosimetric signal) on 19 most widely used composites for tooth restoration, and on 14 experimental resins made with the most characteristic monomers found in commercial composites. Although a strong EPR signal was observed in every material, a rapid decay of the signal was noted. Six months after the polymerization, the signal was negligible in most composites compared to a 3 Gy dosimetric signal in a tooth. In some cases, a stable atypical signal was observed, which was still interfering with the dosimetric signal.

  13. Larger Maximum Tumor Diameter at Radical Prostatectomy Is Associated With Increased Biochemical Failure, Metastasis, and Death From Prostate Cancer After Salvage Radiation for Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Skyler B.; Hamstra, Daniel A.; Jackson, William C.; Zhou, Jessica; Foster, Benjamin; Foster, Corey; Song, Yeohan; Li, Darren [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Palapattu, Ganesh S. [Department of Urology, University of Michigan, Ann Arbor, Michigan (United States); Kunju, Lakshmi; Mehra, Rohit [Department of Pathology, University of Michigan, Ann Arbor, Michigan (United States); Sandler, Howard [Cedars-Sinai Medical Center, Los Angeles, California (United States); Feng, Felix Y., E-mail: ffeng@med.umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)

    2013-10-01

    Purpose: To investigate the maximum tumor diameter (MTD) of the dominant prostate cancer nodule in the radical prostatectomy specimen as a prognostic factor for outcome in patients treated with salvage external beam radiation therapy (SRT) for a rising prostate-specific antigen (PSA) value after radical prostatectomy. Methods and Materials: From an institutional cohort of 575 patients treated with SRT, data on MTD were retrospectively collected. The impact of MTD on biochemical failure (BF), metastasis, and prostate cancer-specific mortality (PCSM) was assessed on univariate and multivariate analysis using Kaplan-Meier and Cox proportional hazards models. Results: In the 173 patients with MTD data available, median follow-up was 77 months (interquartile range, 47-104 months) after SRT, and median MTD was 18 mm (interquartile range, 13-22 mm). Increasing MTD correlated with increasing pT stage, Gleason score, presence of seminal vesicle invasion, and lymph node invasion. Receiver operating characteristic curve analysis identified MTD of >14 mm to be the optimal cut-point. On univariate analysis, MTD >14 mm was associated with an increased risk of BF (P=.02, hazard ratio [HR] 1.8, 95% confidence interval [CI] 1.2-2.8), metastasis (P=.002, HR 4.0, 95% CI 2.1-7.5), and PCSM (P=.02, HR 8.0, 95% CI 2.9-21.8). On multivariate analysis MTD >14 mm remained associated with increased BF (P=.02, HR 1.9, 95% CI 1.1-3.2), metastasis (P=.02, HR 3.4, 95% CI 1.2-9.2), and PCSM (P=.05, HR 9.7, 95% CI 1.0-92.4), independent of extracapsular extension, seminal vesicle invasion, positive surgical margins, pre-RT PSA value, Gleason score, and pre-RT PSA doubling time. Conclusions: For patients treated with SRT for a rising PSA value after prostatectomy, MTD at time of radical prostatectomy is independently associated with BF, metastasis, and PCSM. Maximum tumor diameter should be incorporated into clinical decision making and future clinical risk assessment tools for those patients

  14. Thermal annihilation of photo-induced radicals following dynamic nuclear polarization to produce transportable frozen hyperpolarized 13C-substrates

    Science.gov (United States)

    Capozzi, Andrea; Cheng, Tian; Boero, Giovanni; Roussel, Christophe; Comment, Arnaud

    2017-06-01

    Hyperpolarization via dynamic nuclear polarization (DNP) is pivotal for boosting magnetic resonance imaging (MRI) sensitivity and dissolution DNP can be used to perform in vivo real-time 13C MRI. The type of applications is however limited by the relatively fast decay time of the hyperpolarized spin state together with the constraint of having to polarize the 13C spins in a dedicated apparatus nearby but separated from the MRI magnet. We herein demonstrate that by polarizing 13C with photo-induced radicals, which can be subsequently annihilated using a thermalization process that maintains the sample temperature below its melting point, hyperpolarized 13C-substrates can be extracted from the DNP apparatus in the solid form, while maintaining the enhanced 13C polarization. The melting procedure necessary to transform the frozen solid into an injectable solution containing the hyperpolarized 13C-substrates can therefore be performed ex situ, up to several hours after extraction and storage of the polarized solid.

  15. UV-Induced Radical Photo-Polymerization: A Smart Tool for Preparing Polymer Electrolyte Membranes for Energy Storage Devices

    Directory of Open Access Journals (Sweden)

    Claudio Gerbaldi

    2012-06-01

    Full Text Available In the present work, the preparation and characterization of quasi-solid polymer electrolyte membranes based on methacrylic monomers and oligomers, with the addition of organic plasticizers and lithium salt, are described. Noticeable improvements in the mechanical properties by reinforcement with natural cellulose hand-sheets or nanoscale microfibrillated cellulose fibers are also demonstrated. The ionic conductivity of the various prepared membranes is very high, with average values approaching 10-3 S cm-1 at ambient temperature. The electrochemical stability window is wide (anodic breakdown voltages > 4.5 V vs. Li in all the cases along with good cyclability in lithium cells at ambient temperature. The galvanostatic cycling tests are conducted by constructing laboratory-scale lithium cells using LiFePO4 as cathode and lithium metal as anode with the selected polymer electrolyte membrane as the electrolyte separator. The results obtained demonstrate that UV induced radical photo-polymerization is a well suited method for an easy and rapid preparation of easy tunable quasi-solid polymer electrolyte membranes for energy storage devices.

  16. UV-Induced Radical Photo-Polymerization: A Smart Tool for Preparing Polymer Electrolyte Membranes for Energy Storage Devices

    Directory of Open Access Journals (Sweden)

    Claudio Gerbaldi

    2012-10-01

    Full Text Available In the present work, the preparation and characterization of quasi-solid polymer electrolyte membranes based on methacrylic monomers and oligomers, with the addition of organic plasticizers and lithium salt, are described. Noticeable improvements in the mechanical properties by reinforcement with natural cellulose hand-sheets or nanoscale microfibrillated cellulose fibers are also demonstrated. The ionic conductivity of the various prepared membranes is very high, with average values approaching 10-3 S cm-1 at ambient temperature. The electrochemical stability window is wide (anodic breakdown voltages > 4.5 V vs. Li in all the cases along with good cyclability in lithium cells at ambient temperature. The galvanostatic cycling tests are conducted by constructing laboratory-scale lithium cells using LiFePO4 as cathode and lithium metal as anode with the selected polymer electrolyte membrane as the electrolyte separator. The results obtained demonstrate that UV induced radical photo-polymerization is a well suited method for an easy and rapid preparation of easy tunable quasi-solid polymer electrolyte membranes for energy storage devices.

  17. Hybrid model of the radiation-induced bystander effect

    Energy Technology Data Exchange (ETDEWEB)

    Braga, Viviane V.B.; Faria, Fernando Pereira de; Grynberg, Suely Epsztein, E-mail: vitoriabraga06@gmail.com, E-mail: fernandopereirabh@gmail.com, E-mail: seg@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    The radiation-induced bystander effect (RIBE) refer to biological alterations in non-irradiated cells that occupy the same medium (culture or tissue) of irradiated cells. The biochemical mechanisms of the RIBE are not completely elucidated. However, several experiments indicate its existence. The objective of this work is to quantify the effect via stochastic and deterministic approaches. The hypotheses of the model are: a) one non-irradiated healthy cell interacts with signals that propagate through the medium. These signals are released by irradiated cells. At the time of interaction cell-signal, the cell can become damaged and signaling or damage and not signaling; b) Both types of damage cells repair with certain rate becoming health cells; c) The diffusion of signals obey the discrete diffusion equation with decay in two dimensions. d) The signal concentration released by irradiated cells depends on the dose in the low dose range (< 0.3 Gy) and saturates for higher dose values. As expected, the temporal analysis of the model as a function of the repair rate shows that the survival fraction decreases as the repair rate is reduced. The analysis of the extent of damage triggered by a signal concentration released by a single irradiated cell at time zero show that the damage grows with the maximum simulation time. The results show good agreement with the experimental data. The stochastic and deterministic methods used are in qualitative agreement, as expected. (author)

  18. Structural investigation of radiation-induced aggregates of ribonuclease

    Energy Technology Data Exchange (ETDEWEB)

    Hajos, Gy.; Delincee, H. (Bundesforschungsanstalt fuer Ernaehrung, Karlsruhe (Germany, F.R.))

    1983-10-01

    Following irradiation of bovine pancreatic ribonuclease in aqueous solution with /sup 60/Co ..gamma..-rays protein aggregates are formed. The nature of the bonds linking these radiation-induced aggregates together has been investigated by chromatographic and electrophoretic methods. Thin-layer gel filtration and polyacrylamide gel electrophoresis, both in the presence of sodium dodecyl sulphate, demonstrated the existence of covalent crosslinks between the aggregates. Non-covalent crosslinking also plays a role in the radiolysis of ribonuclease. Thin-layer gel filtration with and without 6 M urea and 2 per cent ..beta..-mercaptoethanol added to the gel, revealed that only part of the covalent bonds between the aggregates consisted of disulphide linkages. By separation of the reduced aggregates by thin-layer gel filtration and electrophoresis, both with SDS, this finding was substantiated. Densitometric measurements indicated for example that the percentage of covalently linked dimers held together by disulphide bridges amounted to about 40-45 per cent, whereas the remaining 55-60 per cent of the dimers must be linked by other covalent bonds. The existence of covalent crosslinks other than disulphide bonds was also confirmed by isoelectric focusing, definite differences being established between the proteolytic hydrolysates of the reduced aggregates and the reduced monomer of ..gamma..-irradiated ribonuclease.

  19. MRI findings in radiation-induced hepatic injuries

    Energy Technology Data Exchange (ETDEWEB)

    Suto, Yuji; Kato, Takashi; Yoshida, Kotaro; Sugihara, Shuji; Kamba, Masayuki; Ohta, Yoshio [Tottori Univ., Yonago (Japan). Faculty of Medicine

    1996-11-01

    To evaluate radiation-induced hepatic injuries (RIHI), magnetic resonance image (MRI) was conducted on 12 patients, to 6 months after radiotherapy on regions including the liver. T1-weighted and T2-weighted image (T1WI, T2WI), and gadopentetate dimeglumine (Gd-DTPA)-enhanced T1WI well obtained. Within 1 week, these MRI studies were repeated after chondroitin sulphate iron colloid (CSIC) administration. MRI findings and total irradiation doses were compared. Abnormalities were seen on one or more types of MRI in 7 patients. The total dose of irradiation was 40 or more Gy in these patients, and 40 or less Gy in those who showed no abnormal MR findings. Plain T2WI of the 7 cases showing MRI abnormalities demonstrated a slightly higher signal intensity (SI) in the irradiated areas in 2, an iso SI in 2, a slightly lower or lower SI in 3 cases. The irradiated and nonirradiated areas were clearly demarcated on Gd-DTPA-enhanced T1WI in 4 cases. Following CSIC administration, the irradiated areas became more marked in 3 cases. A clear demarcation between the 2 areas was obtained with double contrast MRI in the 7 cases. The present study indicates that MRI may be a useful noninvasive means of evaluating RIHI. (author)

  20. Radiation Sialadenitis Induced by High-dose Radioactive Iodine Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Shin Young; Lee, Jaetae [Kyungpook National University Hospital, Daegu (Korea, Republic of)

    2010-06-15

    Radioactive iodine ({sup 131}I) is accumulated in the thyroid tissue and plays an important role in the treatment of differentiated papillary and follicular cancers after thyroidectomy. Simultaneously, {sup 131}I is concentrated in the salivary glands and secreted into the saliva. Dose-related damage to the salivary parenchyma results from the {sup 131}I irradiation. Salivary gland swelling and pain, usually involving the parotid, can be seen. The symptoms may develop immediately after a therapeutic dose of {sup 131}I and/or months later and progress in intensity with time. In conjunction with the radiation sialadenitis, secondary complications reported include xerostomia, taste alterations, infection, increases in caries, facial nerve involvement, candidiasis, and neoplasia. Prevention of {sup 131}I sialadenitis may involve the use of sialogogic agents to hasten the transit time of the radioactive iodine through the salivary glands. However, studies are not available to delineate the efficacy of this approach. Treatment of the varied complications that may develop encompass numerous approaches and include gland massage, sialogogic agents, duct probing, antibiotics, mouthwashes, good oral hygiene, and adequate hydration. Recently interventional sialoendoscopy has been introduced an effective tool for the management of patients with {sup 131}I-induced sialadenitis that is unresponsive to medical treatment.

  1. Radiation-induced gene expression in the nematode Caenorhabditis elegans

    Science.gov (United States)

    Nelson, Gregory A.; Jones, Tamako A.; Chesnut, Aaron; Smith, Anna L.

    2002-01-01

    We used the nematode C. elegans to characterize the genotoxic and cytotoxic effects of ionizing radiation in a simple animal model emphasizing the unique effects of charged particle radiation. Here we demonstrate by RT-PCR differential display and whole genome microarray hybridization experiments that gamma rays, accelerated protons and iron ions at the same physical dose lead to unique transcription profiles. 599 of 17871 genes analyzed (3.4%) showed differential expression 3 hrs after exposure to 3 Gy of radiation. 193 were up-regulated, 406 were down-regulated and 90% were affected only by a single species of radiation. A novel statistical clustering technique identified the regulatory relationships between the radiation-modulated genes and showed that genes affected by each radiation species were associated with unique regulatory clusters. This suggests that independent homeostatic mechanisms are activated in response to radiation exposure as a function of track structure or ionization density.

  2. Acute effects of blood flow restriction on exercise-induced free radical production in young and healthy subjects.

    Science.gov (United States)

    Centner, Christoph; Zdzieblik, Denise; Dressler, Patrick; Fink, Bruno; Gollhofer, Albert; König, Daniel

    2018-02-16

    The main purpose of this study was to investigate the acute local and systemic effects of low-load resistance exercise (30% 1RM) with partial vascular occlusion on exercise-induced free radical production and to compare these effects with other established training methods. Fifteen young and healthy males (25 ± 3 years) performed the following four sessions in a counterbalanced order on separate days: low-load resistance exercise (LI: 30% 1RM), low-load resistance exercise with blood flow restriction (LIBR: 30% 1RM), high-load resistance exercise (HI: 80% 1RM) and an additional session without exercise but blood flow restriction only (BR). Blood samples were obtained 15 minutes prior to and immediately after exercise sessions from the right index finger and first toe. To analyze concentrations of reactive oxygen species (ROS), electron paramagnetic resonance (EPR) spectroscopy was used. Additionally, mitochondrial ROS production was measured by adding inhibitors of electron transport chain complex III. There was an increased systemic ROS generation after the LIBR session from 0.838 ± 0.096-0.901 ± 0.095 µmol/l/min. However, no local or systemic time × condition interaction was detected for ROS production. Regarding mitochondrial ROS production, results were not different between the conditions. Although the low-load resistance exercise session with partial vascular occlusion elicited systemic increases of ROS production, no significant changes were seen on a local level. We assume that this ROS concentration might not be high enough to induce cellular damage but is rather involved in muscle remodulation. However, this needs to be confirmed by future research.

  3. Moringa oleifera Lam. seed extract prevents fat diet induced oxidative stress in mice and protects liver cell-nuclei from hydroxyl radical mediated damage.

    Science.gov (United States)

    Das, Nilanjan; Ganguli, Debdutta; Dey, Sanjit

    2015-12-01

    High fat diet (HFD) prompts metabolic pattern inducing reactive oxygen species (ROS) production in mitochondria thereby triggering multitude of chronic disorders in human. Antioxidants from plant sources may be an imperative remedy against this disorder. However, it requires scientific validation. In this study, we explored if (i) Moringa oleifera seed extract (MoSE) can neutralize ROS generated in HFD fed mice; (ii) protect cell-nuclei damage developed by Fenton reaction in vitro. Swiss mice were fed with HFD to develop oxidative stress model (HFD group). Other groups were control, seed extract alone treated, and MoSE simultaneously (HS) treated. Treatment period was of 15 days. Antioxidant enzymes with tissue nitrite content (TNC) and lipid peroxidation (LPO) were estimated from liver homogenate. HS group showed significantly higher (P < 0.05) superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH) activity, and ferric reducing antioxidant power (FRAP) compared to only HFD fed group. Further, TNC and LPO decreased significantly (P < 0.05) in HS group compared to HFD fed group. MoSE also protected hepatocytes nuclei from the hydroxyl radicals generated by Fenton reaction. MoSE was found to be polyphenol rich with potent reducing power, free radicals and hydroxyl radicals scavenging activity. Thus, MoSE exhibited robust antioxidant prospective to neutralize ROS developed in HFD fed mice and also protected the nuclei damage from hydroxyl radicals. Hence, it can be used as herbal medication against HFD induced ROS mediated disorders.

  4. Subsequent radical fragmentation reactions of N, N-diethylamino-substituted azobenzene derivatives in a Fourier transform ion cyclotron resonance mass spectrometer using collision-induced dissociation and photodissociation.

    Science.gov (United States)

    Clemen, Martin; Grotemeyer, Jürgen

    2017-12-01

    The fragmentation behavior of N, N-diethylamino-substituted azobenzene derivatives is investigated by high-resolving mass spectrometry using a Fourier transform ion cyclotron resonance mass spectrometer. Former investigations by photodissociation as well as collision-induced dissociation experiments used to induce a loss of C 3 H 8 from the diethylamino group. The position of the additional proton in [M + H] + ions is important due to the sequences of radical fragmentation reactions. Two possibilities arise. First, a charge is located at the azo group leading to a methyl radical loss. The second possibility is that the charge has been located on the aniline nitrogen of the molecule resulting in an ethyl radical loss. Only o-ethyl red has shown the overall loss of C 3 H 8 in a two-step radical reaction mechanism. Nevertheless, p-ethyl red and ethyl yellow have shown systematic fragmentation reactions as well. Loss of C 3 H 8 has not been likely regarding both these molecules. All experimental findings together with quantum chemical calculations as well as kinetic calculations support the proposed fragmentation mechanisms of the three azo dyes.

  5. Nature of oxygen containing radicals in radiation chemistry and photochemistry of aqueous solutions. Annual progress report, September 1978--July 1979

    Energy Technology Data Exchange (ETDEWEB)

    Czapski, G

    1979-01-01

    The proposed research is a continuation of the work conducted under this contract and is outlined. During this year, the main emphasis will be given to study further the properties of HO/sub 2/ and O/sub 2//sup -/ and OH, mainly in their role in biological systems. We will continue to study and elucidate how O/sub 2//sup -/ reacts in biological systems. The toxicity of O/sub 2//sup -/ is quite well established, but the mechanism is still obscure. The Haber Weiss reaction most probably can not account for the toxicity of O/sub 2//sup -/ nor for the formation of singlet oxygen, nor of OH. We will study if reduction of Fe/sup 3 +/ complexes by O/sub 2//sup -/ in biological systems does catalyze the Haber Weiss reaction and if OH is formed in this mechanism. The role of oxygen, radiosensitizers in radiation damage of bacteriophages and cells will be further studied, as well as on E. Coli and Enzymes. We will try to elucidate the formation and role of OH, O/sub 2//sup -/ and O/sub 2/ in these systems as well as the relative contribution of endogenous and exogenous damage, and the role of direct and indirect radiation damage to cells. We intend also to study if SOD (super oxide dismutase) does react only with O/sub 2//sup -/ or also with biological peroxides (RO/sub 2/) and Hydroperoxides (RO/sub 2/H). Further studies of O/sub 2//sup -/ and O/sub 2/ with various cytochromes, and hemoglobins is planned.

  6. Harmonic Tracking of Acoustic Radiation Force Induced Displacements

    Science.gov (United States)

    Doherty, Joshua R.; Dahl, Jeremy J.; Trahey, Gregg E.

    2014-01-01

    Ultrasound-based elasticity imaging methods rely upon accurate estimates of tissue deformation to characterize the mechanical properties of soft tissues. These methods are corrupted by clutter, which can bias and/or increase variance in displacement estimates. Harmonic imaging methods are routinely used for clutter suppression and improved image quality in conventional B-mode ultrasound, but have not been utilized in ultrasound-based elasticity imaging methods. We introduce a novel, fully-sampled pulse inversion harmonic method for tracking tissue displacements that corrects the loss in temporal sampling frequency associated with conventional pulse inversion techniques. The method is implemented with Acoustic Radiation Force Impulse (ARFI) imaging to monitor the displacements induced by an impulsive acoustic radiation force excitation. Custom pulse sequences were implemented on a diagnostic ultrasound scanner to collect spatially-matched fundamental and harmonic information within a single acquisition. B-mode and ARFI images created from fundamental data collected at 4 MHz and 8 MHz are compared with 8 MHz harmonic images created using a bandpass filter approach and the fully sampled pulse inversion method. In homogeneous, tissue-mimicking phantoms, where no visible clutter was observed, there was little difference in the axial displacements, estimated jitter, and normalized cross-correlation among the fundamental and harmonic tracking methods. The similarity of the lower and higher frequency methods suggests that any improvement due to the increased frequency of the harmonic components is negligible. The harmonic tracking methods demonstrated a marked improvement in B-mode and ARFI image quality of in vivo carotid arteries. Improved feature detection and decreased variance in estimated displacements were observed in the arterial walls of harmonic ARFI images, especially in the pulse inversion harmonic ARFI images. Within the lumen, the harmonic tracking methods

  7. Harmonic tracking of acoustic radiation force-induced displacements.

    Science.gov (United States)

    Doherty, Joshua R; Dahl, Jeremy J; Trahey, Gregg E

    2013-11-01

    Ultrasound-based elasticity imaging methods rely upon accurate estimates of tissue deformation to characterize the mechanical properties of soft tissues. These methods are corrupted by clutter, which can bias and/or increase variance in displacement estimates. Harmonic imaging methods are routinely used for clutter suppression and improved image quality in conventional B-mode ultrasound, but have not been utilized in ultrasound-based elasticity imaging methods. We introduce a novel, fully-sampled pulse-inversion harmonic method for tracking tissue displacements that corrects the loss in temporal sampling frequency associated with conventional pulse-inversion techniques. The method is implemented with acoustic radiation force impulse (ARFI) imaging to monitor the displacements induced by an impulsive acoustic radiation force excitation. Custom pulse sequences were implemented on a diagnostic ultrasound scanner to collect spatially-matched fundamental and harmonic information within a single acquisition. B-mode and ARFI images created from fundamental data collected at 4 MHz and 8 MHz are compared with 8-MHz harmonic images created using a band-pass filter approach and the fully sampled pulse-inversion method. In homogeneous, tissue-mimicking phantoms, where no visible clutter was observed, there was little difference in the axial displacements, estimated jitter, and normalized cross-correlation among the fundamental and harmonic tracking methods. The similarity of the lower- and higher-frequency methods suggests that any improvement resulting from the increased frequency of the harmonic components is negligible. The harmonic tracking methods demonstrated a marked improvement in B-mode and ARFI image quality of in vivo carotid arteries. Improved feature detection and decreased variance in estimated displacements were observed in the arterial walls of harmonic ARFI images, especially in the pulse-inversion harmonic ARFI images. Within the lumen, the harmonic tracking

  8. Radiation induced membrane effects at the apoptotic cell death; Strahleninduzierte Membraneffekte beim apoptotischen Zelltod

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, H.A. [Inst. fuer Experimentelle Physik, Abt. Biophysik, Bremen Univ. (Germany); Ojeda, F. [Inst. de Fisica, Universidad Austral de Chile, Valdivia (Chile)

    1996-12-31

    Lymphocytes are rather sensitive towards radiation induced apoptosis. The hypothesis can be tried that the cellular membrane (or intracellular membranes) be the primary target for the radiation induced apoptosis. Chemically induced and radiation induced apoptosis follow, at least partially, common mechanistic patterns. It involves a fluidisation of the cellular membrane. Rigidisation of the membrane by incorporation of cholesterol interferes with the radiation induced apoptosis. (orig.) [Deutsch] Lymphozyten sind sehr empfindlich gegen die strahleninduzierte Apoptosis. Die Hypothese wird aufgestellt, dass die Zellmembran (oder intrazellulaere Membranen) Primaertarget der Strahlung zur Induktion der Apoptose ist. Die chemisch induzierte und die strahleninduzierte Apoptose haben, zumindest partiell, gemeinsame Mechanismenstraenge. Sie geht einher mit einer Fludisierung der Zellmembran. Rigidisierung der Zellmembran durch Einbau von Cholesterin interferiert mit der strahleninduzierten Apoptose. (orig.)

  9. A Nonhuman Primate Model of Human Radiation-Induced Venocclusive Liver Disease and Hepatocyte Injury

    Energy Technology Data Exchange (ETDEWEB)

    Yannam, Govardhana Rao [Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska (United States); Han, Bing [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Department of Hepatobiliary Surgery, First Affiliated Hospital of Xi' an Jiaotong University, Xi' an, Shaanxi (China); Setoyama, Kentaro [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Yamamoto, Toshiyuki [Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska (United States); Ito, Ryotaro; Brooks, Jenna M. [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Guzman-Lepe, Jorge [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Department of Pathology, Children' s Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Galambos, Csaba [Department of Pathology, Children' s Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Fong, Jason V. [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Deutsch, Melvin; Quader, Mubina A. [Department of Radiation Oncology, Children' s Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Yamanouchi, Kosho [Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, New York (United States); Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, New York (United States); Kabarriti, Rafi; Mehta, Keyur [Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, New York (United States); Soto-Gutierrez, Alejandro [Department of Pathology, Children' s Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); and others

    2014-02-01

    Background: Human liver has an unusual sensitivity to radiation that limits its use in cancer therapy or in preconditioning for hepatocyte transplantation. Because the characteristic veno-occlusive lesions of radiation-induced liver disease do not occur in rodents, there has been no experimental model to investigate the limits of safe radiation therapy or explore the pathogenesis of hepatic veno-occlusive disease. Methods and Materials: We performed a dose-escalation study in a primate, the cynomolgus monkey, using hypofractionated stereotactic body radiotherapy in 13 animals. Results: At doses ≥40 Gy, animals developed a systemic syndrome resembling human radiation-induced liver disease, consisting of decreased albumin, elevated alkaline phosphatase, loss of appetite, ascites, and normal bilirubin. Higher radiation doses were lethal, causing severe disease that required euthanasia approximately 10 weeks after radiation. Even at lower doses in which radiation-induced liver disease was mild or nonexistent, latent and significant injury to hepatocytes was demonstrated by asialoglycoprotein-mediated functional imaging. These monkeys developed hepatic failure with encephalopathy when they received parenteral nutrition containing high concentrations of glucose. Histologically, livers showed central obstruction via an unusual intimal swelling that progressed to central fibrosis. Conclusions: The cynomolgus monkey, as the first animal model of human veno-occlusive radiation-induced liver disease, provides a resource for characterizing the early changes and pathogenesis of venocclusion, for establishing nonlethal therapeutic dosages, and for examining experimental therapies to minimize radiation injury.

  10. Nature of oxygen containing radicals in radiation chemistry and photochemistry of aqueous solutions. Annual progress report, September 1979-July 1980

    Energy Technology Data Exchange (ETDEWEB)

    Czapski, G.

    1980-01-01

    During this year, emphasis will be given on the properties of HO/sub 2/ and O/sub 2//sup -/ and OH, mainly in their role in biological systems. We will continue to study and elucidate how O/sub 2//sup -/ reacts in biological systems. The toxicity of O/sub 2//sup -/ is quite well established but the mechanism is still obscure. One way O/sub 2//sup -/ is toxic is that OH is formed from O/sub 2//sup -/ through reduction of Fe/sup 3 +/, and subsequently the reaction of Fe/sup 2 +/ with H/sub 2/O/sub 2/ (Fenton reaction). This mechanism is sometimes called the Haber Weiss Reaction. We will study if reduction of Fe/sup 3 +/ complexes by O/sub 2//sup -/ in biological systems does catalyze the Haber Weiss reaction and if OH is formed in this mechanism. The role of oxygen, radiosensitizers in radiation damage of bacteriophages and cells will be further studied, as well as on E. coli and enzymes. Use of different mutants, such as ones with repair deficiencies, or others which are deficient in glutathione will help to elucidate the role of O/sub 2//sup -/ and O/sub 2/ toxicity. We will try to elucidate the formation and role of OH, O/sub 2//sup -/ and O/sub 2/ in these systems as well as the relative contribution of endogenous and exogenous damage, and the role of direct and indirect radiation damage to cells. As there is some doubt how and if SOD protects cells from irradiation as literature results show lots of conflict, we will try to clear this point, in studies with E. coli mutants, and adding SOD endogenously and exogenously. We also intend to study if SOD (super oxide dismutase) does react only with O/sub 2//sup -/ or also with biological peroxides (RO/sub 2/) and hydroperoxides (RO/sub 2/H). Further studies of O/sub 2//sup -/ and O/sub 2/ with various cytochromes, and hemoglobins is planned.

  11. Spinal Cord Glioblastoma Induced by Radiation Therapy of Nasopharyngeal Rhabdomyosarcoma with MRI Findings: Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Se Jin; Kim, In One [Dept. of Radiology, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2012-09-15

    Radiation-induced spinal cord gliomas are extremely rare. Since the first case was reported in 1980, only six additional cases have been reported.; The radiation-induced gliomas were related to the treatment of Hodgkin's lymphoma, thyroid cancer, and medullomyoblastoma, and to multiple chest fluoroscopic examinations in pulmonary tuberculosis patient. We report a case of radiation-induced spinal cord glioblastoma developed in a 17-year-old girl after a 13-year latency period following radiotherapy for nasopharyngeal rhabdomyosarcoma. MRI findings of our case are described.

  12. Radiation Recall Reaction Induced by Adjuvant Trastuzumab (Herceptin

    Directory of Open Access Journals (Sweden)

    Caroline Chung

    2009-01-01

    trastuzumab (Herceptin administration, there has been no published case of radiation recall reaction associated with trastuzumab. This case describes a clinical presentation consistent with a radiation recall reaction following administration of adjuvant trastuzumab after neoadjuvant FEC-D chemotherapy and locoregional radiotherapy for HER2-positive, locally advanced breast cancer in a premenopausal woman. Although the mechanism and etiology of radiation recall dermatitis remain unclear, this case raises further hypotheses regarding a possible drug dose-dependence and possible predisposing risk factor for the development of radiation recall reactions.

  13. Vacuum radiation induced by time dependent electric field

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bo, E-mail: zhangbolfrc@caep.cn [Department of High Energy Density Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China); Laboratory of Science and Technology on Plasma Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China); Zhang, Zhi-meng; Hong, Wei; He, Shu-Kai; Teng, Jian [Department of High Energy Density Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China); Laboratory of Science and Technology on Plasma Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China); Gu, Yu-qiu, E-mail: yqgu@caep.cn [Department of High Energy Density Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China); Laboratory of Science and Technology on Plasma Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China)

    2017-04-10

    Many predictions of new phenomena given by strong field quantum electrodynamics (SFQED) will be tested on next generation multi-petawatt laser facilities in the near future. These new phenomena are basis to understand physics in extremely strong electromagnetic fields therefore have attracted wide research interest. Here we discuss a new SFQED phenomenon that is named as vacuum radiation. In vacuum radiation, a virtual electron loop obtain energy from time dependent external electric field and radiate an entangled photon pair. Features of vacuum radiation in a locally time dependent electric field including spectrum, characteristic temperature, production rate and power are given.

  14. Vacuum radiation induced by time dependent electric field

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    2017-04-01

    Full Text Available Many predictions of new phenomena given by strong field quantum electrodynamics (SFQED will be tested on next generation multi-petawatt laser facilities in the near future. These new phenomena are basis to understand physics in extremely strong electromagnetic fields therefore have attracted wide research interest. Here we discuss a new SFQED phenomenon that is named as vacuum radiation. In vacuum radiation, a virtual electron loop obtain energy from time dependent external electric field and radiate an entangled photon pair. Features of vacuum radiation in a locally time dependent electric field including spectrum, characteristic temperature, production rate and power are given.

  15. Radiation-Induced Liver Damage: Correlation of Histopathology with Hepatobiliary Magnetic Resonance Imaging, a Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Seidensticker, Max, E-mail: max.seidensticker@med.ovgu.de [Universitätsklinik Magdeburg, Klinik für Radiologie und Nuklearmedizin (Germany); Burak, Miroslaw [Pomeranian Medical University, Department of Diagnostic Imaging and Interventional Radiology (Poland); Kalinski, Thomas [Universitätsklinik Magdeburg, Institut für Pathologie (Germany); Garlipp, Benjamin [Universitätsklinik Magdeburg, Klinik für Allgemein-, Viszeral- und Gefäßchirurgie (Germany); Koelble, Konrad [Philipps Universität Marburg, Fachbereich Medizin der, Abteilung für Neuropathologie (Germany); Wust, Peter [Charité Universitätsmedizin Berlin, Klinik für Radioonkologie und Strahlentherapie (Germany); Antweiler, Kai [Universitätsklinik Magdeburg, Institut für Biometrie und Medizinische Informatik (Germany); Seidensticker, Ricarda; Mohnike, Konrad; Pech, Maciej; Ricke, Jens [Universitätsklinik Magdeburg, Klinik für Radiologie und Nuklearmedizin (Germany)

    2015-02-15

    PurposeRadiotherapy of liver malignancies shows promising results (radioembolization, stereotactic irradiation, interstitial brachytherapy). Regardless of the route of application, a certain amount of nontumorous liver parenchyma will be collaterally damaged by radiation. The functional reserve may be significantly reduced with an impact on further treatment planning. Monitoring of radiation-induced liver damage by imaging is neither established nor validated. We performed an analysis to correlate the histopathological presence of radiation-induced liver damage with functional magnetic resonance imaging (MRI) utilizing hepatobiliary contrast media (Gd-BOPTA).MethodsPatients undergoing local high-dose-rate brachytherapy for whom a follow-up hepatobiliary MRI within 120 days after radiotherapy as well as an evaluable liver biopsy from radiation-exposed liver tissue within 7 days before MRI were retrospectively identified. Planning computed tomography (CT)/dosimetry was merged to the CT-documentation of the liver biopsy and to the MRI. Presence/absence of radiation-induced liver damage (histopathology) and Gd-BOPTA uptake (MRI) as well as the dose applied during brachytherapy at the site of tissue sampling was determined.ResultsFourteen biopsies from eight patients were evaluated. In all cases with histopathological evidence of radiation-induced liver damage (n = 11), no uptake of Gd-BOPTA was seen. In the remaining three, cases no radiation-induced liver damage but Gd-BOPTA uptake was seen. Presence of radiation-induced liver damage and absence of Gd-BOPTA uptake was correlated with a former high-dose exposition.ConclusionsAbsence of hepatobiliary MRI contrast media uptake in radiation-exposed liver parenchyma may indicate radiation-induced liver damage. Confirmatory studies are warranted.

  16. Synchrotron-Radiation Induced X-Ray Emission (SRIXE)

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Keith W.

    1999-09-01

    and increase in scientific use can be maintained for the synchrotron x-ray source. A short summary of the present state of the synchrotron radiation-induced x-ray emission (SRIXE) method is presented here. Basically, SRIXE experiments can include any that depend on the detection. of characteristic x-rays produced by the incident x-ray beam born the synchrotron source as they interact with a sample. Thus, experiments done to measure elemental composition, chemical state, crystal, structure, and other sample parameters can be considered in a discussion of SRIXE. It is also clear that the experimentalist may well wish to use a variety of complementary techniques for study of a given sample. For this reason, discussion of computed microtomography (CMT) and x-ray diffraction is included here. It is hoped that this present discussion will serve as a succinct introduction to the basic ideas of SRIXE for those not working in the field and possibly help to stimulate new types of work by those starting in the field as well as by experienced practitioners of the art. The topics covered include short descriptions of (1) the properties of synchrotron radiation, (2) a description of facilities used for its production, (3) collimated microprobe, (4) focused microprobes, (5) continuum and monoenergetic excitation, (6) detection limits, (7) quantitation, (8) applications of SRIXE, (9) computed microtomography (CMT), and (10)chemical speciation using x-ray absorption near-edge structure (XANES) and extended x-ray absorption fine structure (EXAFS). An effort has been made to cite a wide variety of work from different laboratories to show the vital nature of the field.

  17. 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.

  18. MRI of radiation-induced tumors of the head and neck in post-radiation nasopharyngeal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Abrigo, Jill M.; King, Ann D.; Wong, Jeffrey K.T.; Ahuja, Anil T. [The Chinese University of Hong Kong, Prince of Wales Hospital, Department of Diagnostic Radiology and Organ Imaging, Faculty of Medicine, Hong Kong S.A.R. (China); Leung, Sing Fai [The Chinese University of Hong Kong, Prince of Wales Hospital, Department of Clinical Oncology, Faculty of Medicine, Hong Kong S.A.R. (China); Vlantis, Alexander C.; Tong, Michael C.F. [The Chinese University of Hong Kong, Prince of Wales Hospital, Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine, Hong Kong S.A.R. (China); Tse, Gary M.K. [The Chinese University of Hong Kong, Prince of Wales Hospital, Department of Anatomical and Cellular Pathology, Faculty of Medicine, Hong Kong S.A.R. (China)

    2009-05-15

    The aim of this study was to document the sites and MRI features of radiation-induced tumors (RITs) in the head and neck following treatment for nasopharyngeal carcinoma (NPC). The MRI examinations and clinical records of 20 patients with 21 RITs were reviewed retrospectively. RITs developed 3-30 years after radiotherapy and included eleven squamous cell carcinomas, six sarcomas, two neuroendocrine carcinomas, one mucoepidermoid carcinoma and one meningioma. RITs arose in the maxillary region (9), oro/hypopharynx and oral cavity (5), external auditory canal (4), nasopharynx and sphenoid sinus (2) and brain (1). Radiation-induced carcinoma and sarcoma had MRI features that were useful to distinguish them from recurrent NPC. To improve early detection of RITs, the check areas on an MRI of a patient with previous NPC treated by radiation should always include the maxillary region, tongue, and external auditory canal/temporal bone. (orig.)

  19. Production of sulfate radical from peroxymonosulfate induced by a magnetically separable CuFe2O4 spinel in water: Efficiency, stability, and mechanism

    KAUST Repository

    Zhang, Tao

    2013-03-19

    A simple, nonhazardous, efficient and low energy-consuming process is desirable to generate powerful radicals from peroxymonosulfate (PMS) for recalcitrant pollutant removal. In this work, the production of radical species from PMS induced by a magnetic CuFe2O4 spinel was studied. Iopromide, a recalcitrant model pollutant, was used to investigate the efficiency of this process. CuFe2O4 showed higher activity and 30 times lower Cu2+ leaching (1.5 μg L-1 per 100 mg L-1) than a well-crystallized CuO at the same dosage. CuFe 2O4 maintained its activity and crystallinity during repeated batch experiments. In comparison, the activity of CuO declined significantly, which was ascribed to the deterioration in its degree of crystallinity. The efficiency of the PMS/CuFe2O4 was highest at neutral pH and decreased at acidic and alkaline pHs. Sulfate radical was the primary radical species responsible for the iopromide degradation. On the basis of the stoichiometry of oxalate degradation in the PMS/CuFe 2O4, the radical production yield from PMS was determined to be near 1 mol/mol. The PMS decomposition involved an inner-sphere complexation with the oxide\\'s surface Cu(II) sites. In situ characterization of the oxide surface with ATR-FTIR and Raman during the PMS decomposition suggested that surface Cu(II)-Cu(III)-Cu(II) redox cycle was responsible for the efficient sulfate radical generation from PMS. © 2013 American Chemical Society.

  20. Radiation-induced unrepairable DSBs: their role in the late effects of radiation and possible applications to biodosimetry.

    Science.gov (United States)

    Noda, Asao

    2017-12-21

    Although the vast majority of DNA damage induced by radiation exposure disappears rapidly, some lesions remain in the cell nucleus in very small quantities for days to months. These lesions may cause a considerable threat to an organism and include certain types of DNA double-strand breaks (DSBs) called 'unrepairable DSBs'. Unrepairable DSBs are thought to cause persistent malfunctioning of cells and tissues or cause late effects of radiation, especially the induction of delayed cell death, mutation, senescence, or carcinogenesis. Moreover, the measurement of unrepairable DSBs could potentially be used for retrospective biodosimetry or for identifying individuals at greater risk for developing the adverse effects associated with radiotherapy or chemotherapy. This review summarizes the concept of unrepairable DSBs in the context of persistent repair foci formed at DSBs. © The Author(s) 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  1. An extract of Polygonum multiflorum protects against free radical damage induced by ultraviolet B irradiation of the skin

    Directory of Open Access Journals (Sweden)

    Hwang I.K.

    2006-01-01

    Full Text Available Over the last decades, the incidence of ultraviolet B (UVB-related skin problems has been increasing. Damages induced by UVB radiation are related to mutations that occur as a result of direct DNA damage and/or the production of reactive oxygen species. We investigated the anti-oxidant effects of a Polygonum multiflorum thumb extract against skin damage induced by UVB irradiation. Female SKH-1 hairless mice were divided into three groups: control (N = 7, distilled water- (N = 10, and P. multiflorum extract-treated (PM, N = 10 groups. The PM (10 g was extracted with 100 mL distilled water, cryo-dried and 9.8 g was obtained. The animals received a topical application of 500 µL distilled water or PM extract (1, 2, 4, 8, and 16%, w/v, dissolved in distilled water for 30 min after UVB irradiation (wavelength 280-320 nm, 300 mJ/cm²; 3 min of the dorsal kin for 14 days, and skin immunohistochemistry and Cu,Zn-superoxide dismutase (SOD1 activity were determined. SOD1 immunoreactivity, its protein levels and activities in the skin were significantly reduced by 70% in the distilled water-treated group after UVB irradiation compared to control. However, in the PM extract-treated groups, SOD1 immunoreactivity and its protein and activity levels increased in a dose-dependent manner (1-16%, w/v, PM extract compared to the distilled water-treated group. SOD1 protein levels and activities in the groups treated with 8 and 16%, w/v, PM extract recovered to 80-90% of the control group levels after UVB. These results suggest that PM extract strongly inhibits the destruction of SOD1 by UV radiation and probably contains anti-skin photoaging agents.

  2. An extract of Polygonum multiflorum protects against free radical damage induced by ultraviolet B irradiation of the skin

    Directory of Open Access Journals (Sweden)

    I.K. Hwang

    Full Text Available Over the last decades, the incidence of ultraviolet B (UVB-related skin problems has been increasing. Damages induced by UVB radiation are related to mutations that occur as a result of direct DNA damage and/or the production of reactive oxygen species. We investigated the anti-oxidant effects of a Polygonum multiflorum thumb extract against skin damage induced by UVB irradiation. Female SKH-1 hairless mice were divided into three groups: control (N = 7, distilled water- (N = 10, and P. multiflorum extract-treated (PM, N = 10 groups. The PM (10 g was extracted with 100 mL distilled water, cryo-dried and 9.8 g was obtained. The animals received a topical application of 500 µL distilled water or PM extract (1, 2, 4, 8, and 16%, w/v, dissolved in distilled water for 30 min after UVB irradiation (wavelength 280-320 nm, 300 mJ/cm²; 3 min of the dorsal kin for 14 days, and skin immunohistochemistry and Cu,Zn-superoxide dismutase (SOD1 activity were determined. SOD1 immunoreactivity, its protein levels and activities in the skin were significantly reduced by 70% in the distilled water-treated group after UVB irradiation compared to control. However, in the PM extract-treated groups, SOD1 immunoreactivity and its protein and activity levels increased in a dose-dependent manner (1-16%, w/v, PM extract compared to the distilled water-treated group. SOD1 protein levels and activities in the groups treated with 8 and 16%, w/v, PM extract recovered to 80-90% of the control group levels after UVB. These results suggest that PM extract strongly inhibits the destruction of SOD1 by UV radiation and probably contains anti-skin photoaging agents.

  3. Rosiglitazone attenuates pulmonary fibrosis and radiation-induced intestinal damage

    Energy Technology Data Exchange (ETDEWEB)

    Mangoni, M.; Gerini, C.; Sottili, M.; Cassani, S.; Stefania, G.; Biti, G. [Radiotherapy Unit, Clinical Physiopathology Department, University of Florence, Firenze (Italy); Castiglione, F. [Department of Human Pathology and Oncology, University of Florence, Firenze (Italy); Vanzi, E.; Bottoncetti, A.; Pupi, A. [Nuclear Medicine Unit, Clinical Physiopathology Department, University of Florence, Firenze (Italy)

    2011-10-15

    Full text of publication follows: Purpose.-The aim of the study was to evaluate radioprotective effect of rosiglitazone (RGZ) on a murine model of late pulmonary damage and of acute intestinal damage. Methods.- Lung fibrosis: C57 mice were treated with the radiomimetic agent bleomycin, with or without rosiglitazone (5 mg/kg/day). To obtain an independent qualitative and quantitative measure for lung fibrosis we used high resolution CT, performed twice a week during the entire observation period. Hounsfield Units (HU) of section slides from the upper and lower lung region were determined. On day 31 lungs were collected for histological analysis. Acute intestinal damage: mice underwent 12 Gy total body irradiation with or without rosiglitazone. Mice were sacrificed 24 or 72 h after total body irradiation and ileum and colon were collected. Results.- Lung fibrosis: after bleomycin treatment, mice showed typical CT features of lung fibrosis, including irregular septal thickening and patchy peripheral reticular abnormalities. Accordingly, HU lung density was dramatically increased. Rosiglitazone markedly attenuated the radiological signs of fibrosis and strongly inhibited HU lung density increase (60% inhibition at the end of the observation period). Histological analysis revealed that in bleomycin-treated mice, fibrosis involved 50-55% of pulmonary parenchyma and caused an alteration of the alveolar structures in 10% of parenchyma, while in rosiglitazone-treated mice, fibrosis involved only 20-25% of pulmonary parenchyma, without alterations of the alveolar structures. Acute intestinal damage: 24 h after 12 Gy of total body irradiation intestinal mucosa showed villi shortening, mucosal thickness and crypt necrotic changes. Rosiglitazone showed a histological improvement of tissue structure, with villi and crypts normalization and oedema reduction. Conclusion.- These results demonstrate that rosiglitazone displays a protective effect on pulmonary fibrosis and radiation-induced

  4. A comparative review of radiation-induced cancer risk models

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Hee; Kim, Ju Youl [FNC Technology Co., Ltd., Yongin (Korea, Republic of); Han, Seok Jung [Risk and Environmental Safety Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-06-15

    With the need for a domestic level 3 probabilistic safety assessment (PSA), it is essential to develop a Korea-specific code. Health effect assessments study radiation-induced impacts; in particular, long-term health effects are evaluated in terms of cancer risk. The objective of this study was to analyze the latest cancer risk models developed by foreign organizations and to compare the methodology of how they were developed. This paper also provides suggestions regarding the development of Korean cancer risk models. A review of cancer risk models was carried out targeting the latest models: the NUREG model (1993), the BEIR VII model (2006), the UNSCEAR model (2006), the ICRP 103 model (2007), and the U.S. EPA model (2011). The methodology of how each model was developed is explained, and the cancer sites, dose and dose rate effectiveness factor (DDREF) and mathematical models are also described in the sections presenting differences among the models. The NUREG model was developed by assuming that the risk was proportional to the risk coefficient and dose, while the BEIR VII, UNSCEAR, ICRP, and U.S. EPA models were derived from epidemiological data, principally from Japanese atomic bomb survivors. The risk coefficient does not consider individual characteristics, as the values were calculated in terms of population-averaged cancer risk per unit dose. However, the models derived by epidemiological data are a function of sex, exposure age, and attained age of the exposed individual. Moreover, the methodologies can be used to apply the latest epidemiological data. Therefore, methodologies using epidemiological data should be considered first for developing a Korean cancer risk model, and the cancer sites and DDREF should also be determined based on Korea-specific studies. This review can be used as a basis for developing a Korean cancer risk model in the future.

  5. Radiation-induced morphological changes in the vagina

    Energy Technology Data Exchange (ETDEWEB)

    Kirchheiner, K.; Fidarova, E.; Schmid, M.P.; Sturdza, A.; Kranz, A.; Poetter, R. [Medical Univ. of Vienna (Austria). Dept. of Radiation Oncology; Nout, R.A. [University Medical Center Leiden (Netherlands). Dept. of Clinical Oncology; Wiebe, E. [Alberta Univ., Cross Cancer Institute, Edmonton, AB (Canada). Dept. of Radiation Oncology; Polterauer, S. [Medical Univ. of Vienna (Austria). Dept. of General Gynecology and Gynecologic Oncology; Doerr, W. [Medical Univ. of Vienna (Austria). Dept. of Radiation Oncology; Medical Univ. of Vienna (Austria). Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology

    2012-11-15

    Background and purpose: Treatment-induced chronic vaginal changes after definitive radio(chemo)therapy for locally advanced cervical cancer patients are reported as one of the most distressing consequences of treatment, with major impact on quality of life. Although these vaginal changes are regularly documented during gynecological follow-up examinations, the classic radiation morbidity grading scales are not concise in their reporting. The aim of the study was therefore to identify and qualitatively describe, on the basis of vaginoscopies, morphological changes in the vagina after definitive radio(chemo)therapy and to establish a classification system for their detailed and reproducible documentation. Patients and methods: Vaginoscopy with photodocumentation was performed prospectively in 22 patients with locally advanced cervical cancer after definitive radio(chemo)therapy at 3-24 months after end of treatment. All patients were in complete remission and without severe grade 3/4 morbidity outside the vagina. Results: Five morphological parameters, which occurred consistently after treatment, were identified: mucosal pallor, telangiectasia, fragility of the vaginal wall, ulceration, and adhesions/occlusion. The symptoms in general were observed at different time points in individual patients; their quality was independent of the time of assessment. Based on the morphological findings, a comprehensive descriptive and semiquantitative scoring system was developed, which allows for classification of vaginal changes. A photographic atlas to illustrate the morphology of the alterations is presented. Conclusion: Vaginoscopy is an easily applicable, informative, and well-tolerated procedure for the objective assessment of morphological vaginal changes after radio(chemo)therapy and provides comprehensive and detailed information. This allows for precise classification of the severity of individual changes. (orig.)

  6. Radiation-induced morphological changes in the vagina.

    Science.gov (United States)

    Kirchheiner, K; Fidarova, E; Nout, R A; Schmid, M P; Sturdza, A; Wiebe, E; Kranz, A; Polterauer, S; Pötter, R; Dörr, W

    2012-11-01

    Treatment-induced chronic vaginal changes after definitive radio(chemo)therapy for locally advanced cervical cancer patients are reported as one of the most distressing consequences of treatment, with major impact on quality of life. Although these vaginal changes are regularly documented during gynecological follow-up examinations, the classic radiation morbidity grading scales are not concise in their reporting. The aim of the study was therefore to identify and qualitatively describe, on the basis of vaginoscopies, morphological changes in the vagina after definitive radio(chemo)therapy and to establish a classification system for their detailed and reproducible documentation. Vaginoscopy with photodocumentation was performed prospectively in 22 patients with locally advanced cervical cancer after definitive radio(chemo)therapy at 3-24 months after end of treatment. All patients were in complete remission and without severe grade 3/4 morbidity outside the vagina. Five morphological parameters, which occurred consistently after treatment, were identified: mucosal pallor, telangiectasia, fragility of the vaginal wall, ulceration, and adhesions/occlusion. The symptoms in general were observed at different time points in individual patients; their quality was independent of the time of assessment. Based on the morphological findings, a comprehensive descriptive and semiquantitative scoring system was developed, which allows for classification of vaginal changes. A photographic atlas to illustrate the morphology of the alterations is presented. Vaginoscopy is an easily applicable, informative, and well-tolerated procedure for the objective assessment of morphological vaginal changes after radio(chemo)therapy and provides comprehensive and detailed information. This allows for precise classification of the severity of individual changes.

  7. Assessment of DNA damage and oxidative stress induced by radiation in Eisenia fetida

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Tae Ho; Kim, Jin Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Nili, Mohammad [Dawnesh Radiation Research Institute, Barcelona (Spain)

    2012-04-15

    Exposure of eukaryotic cells to ionizing radiation results in the immediate formation of free radicals and the occurrence of oxidative cell damage. Recently International Commission on Radiological Protection (ICRP) requires the effect data of ionizing radiation on non-human biota for the radiological protection of the environment. Based on their radioecological properties and their important role in the soil ecosystem, earthworms have been identified by the ICRP as one of the reference animals and plants (RAPs) to be used in environmental radiation protection. The investigation shows that oxidative stress is closely related to the exposed dose of radiation in the environment. To evaluate oxidative stress by ionizing radiation in the earthworm, we performed several experiments. The comet assay is known as a measurement which is one of the best techniques in assessing the DNA damage by oxidative stress. The SOD is a key enzyme in protecting cells against oxidative stress. An increase in the level of antioxidant enzyme such as SOD indicated that the exposure to radiation caused stress responses. Glutathione oxidation is considered as a maker for detection of reactive oxygen species (ROS). The GSSG levels increased progressively with increased exposure dose of ionizing radiation, which suggested a dose-dependent ROS generation.

  8. Gamma radiation induced effects in floppy and rigid Ge-containing chalcogenide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ailavajhala, Mahesh S.; Mitkova, Maria [Department of Electrical Engineering, Boise State University, 1910 University Dr. Boise, Idaho 83725-2075 (United States); Gonzalez-Velo, Yago; Barnaby, Hugh; Kozicki, Michael N.; Holbert, Keith [School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287-9309 (United States); Poweleit, Christian [Department of Physics, Arizona State University, Tempe, Arizona 85287-1504 (United States); Butt, Darryl P. [Department of Material Science and Engineering, Boise State University, 1910 University Dr. Boise, Idaho 83725-2090 (United States)

    2014-01-28

    We explore the radiation induced effects in thin films from the Ge-Se to Ge-Te systems accompanied with silver radiation induced diffusion within these films, emphasizing two distinctive compositional representatives from both systems containing a high concentration of chalcogen or high concentration of Ge. The studies are conducted on blanket chalcogenide films or on device structures containing also a silver source. Data about the electrical conductivity as a function of the radiation dose were collected and discussed based on material characterization analysis. Raman Spectroscopy, X-ray Diffraction Spectroscopy, and Energy Dispersive X-ray Spectroscopy provided us with data about the structure, structural changes occurring as a result of radiation, molecular formations after Ag diffusion into the chalcogenide films, Ag lateral diffusion as a function of radiation and the level of oxidation of the studied films. Analysis of the electrical testing suggests application possibilities of the studied devices for radiation sensing for various conditions.

  9. 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.

  10. Mechanisms of Radiation Induced Effects in Carbon Nanotubes

    Science.gov (United States)

    2016-10-01

    understanding the fundamental radiation response of nanocarbon materials (CNTs and graphene ) and the nanoscale electronic devices comprising them. The...earmarked to replace conventional semiconductor devices in the near future. At the onset of the current program, carbon nanotube technology was...research agenda was highly impactful on understanding the fundamental radiation response of nanocarbon materials (CNTs and graphene ) and the nanoscale

  11. Radiation 98 incorporating the 19th AINSE radiation chemistry conference, the 16th AINSE radiation biology conference and the 7th meeting of the Society for Free Radical Research Australasia. Conference Handbook

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    Topics covered in this conference include: protein oxidation, antioxidants, radiation chemistry, radiolabelled compounds and their use, radiation effects, radiosensitivity, radiation monitoring. The booklet contains abstracts of papers presented at the conference; 64 of them considered to be in INIS scope have been separately indexed

  12. 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.

  13. Radiation-induced mechanical property changes in filled rubber.

    Science.gov (United States)

    Maiti, A; Weisgraber, T H; Gee, R H; Small, W; Alviso, C T; Chinn, S C; Maxwell, R S

    2011-06-01

    In a recent paper we exposed a filled elastomer to controlled radiation dosages and explored changes in its cross-link density and molecular weight distribution between network junctions [A. Maiti et al., Phys. Rev. E 83, 031802 (2011)]. Here we report mechanical response measurements when the material is exposed to radiation while being under finite nonzero strain. We observe interesting hysteretic behavior and material softening representative of the Mullins effect, and materials hardening due to radiation. The net magnitude of the elastic modulus depends upon the radiation dosage, strain level, and strain-cycling history of the material. Using the framework of Tobolsky's two-stage independent network theory we develop a model that can quantitatively interpret the observed elastic modulus and its radiation and strain dependence.

  14. Curative effect of Terminalia chebula extract on acetic acid-induced experimental colitis: role of antioxidants, free radicals and acute inflammatory marker.

    Science.gov (United States)

    Gautam, M K; Goel, Shalini; Ghatule, R R; Singh, A; Nath, G; Goel, R K

    2013-10-01

    The present study has evaluated the healing effects of extract of dried fruit pulp of Terminalia chebula (TCE) on acetic acid (AA)-induced colitis in rats. TCE (600 mg/kg) showed healing effects against AA-induced colonic damage score and weight when administered orally daily for 14 days. TCE was further studied for its effects on various physical (mucus/blood in stool and stool frequency, food and water intake and body weight changes), histology, antibacterial activity and free radicals (NO and LPO), antioxidants (SOD, CAT and GSH) and myeloperoxidase in colonic tissue. Intra-colonic AA administration increased colonic mucosal damage and inflammation, mucus/bloody diarrhoea, stool frequency, but decreased body weight which were reversed by TCE and sulfasalazine (SS, positive control) treatments. TCE showed antibacterial activity and both TCE and SS enhanced the antioxidants, but decreased free radicals and myeloperoxidase activities affected in acetic acid-induced colitis. TCE indicated the presence of active principles with proven antioxidants, anti-inflammatory, immunomodulatory, and free radical scavenging and healing properties. Thus, TCE seemed to be safe and effective in healing experimental colitis.

  15. Should regional ventilation function be considered during radiation treatment planning to prevent radiation-induced complications?

    Science.gov (United States)

    Lan, Fujun; Jeudy, Jean; Senan, Suresh; van Sornsen de Koste, J R; D'Souza, Warren; Tseng, Huan-Hsin; Zhou, Jinghao; Zhang, Hao

    2016-09-01

    -subvolume metrics were significant (P values ≤ 0.02) in predicting volume airway dilation. Likelihood ratio test showed that when combining dose-function and/or dose-subvolume metrics with dose-volume metrics, the achieved improvements of prediction accuracy on volume loss and airway dilation were significant (P values ≤ 0.04). The authors' results demonstrated that the inclusion of regional ventilation function improved accuracy in predicting RF. In particular, dose-subvolume metrics provided a promising method for preventing radiation-induced pulmonary complications.

  16. Reductions in Calcium Uptake Induced in Rat Brain Synaptosomes by Ionizing Radiation

    Science.gov (United States)

    1991-01-01

    located in the brain and heart using nimodipine and Reductions in Calcium Uptake Induced in Rat Brain Synapto- nifedipine (I1-13). Nimodipine binding...was also reduced by radiation exposure. Nimodipine binding to dihydropyridine (DHP) L-type calcium uptake after irradiation in wh31e-brain, cortical...resistant to the direct effects of MATERIALS AND METHODS ionizing radiation, exposure to ionizing radiation can have Materials. Bay K 8644 and nimodipine

  17. Free radical scavenging enzyme activity and related trace metals in clozapine-induced agranulocytosis: a pilot study.

    Science.gov (United States)

    Linday, L A; Pippenger, C E; Howard, A; Lieberman, J A

    1995-10-01

    We hypothesized that patients who had experienced clozapine-induced agranulocytosis would have abnormalities in their free radical scavenging enzyme activity (FRESA) and levels of related trace metals. We therefore measured FRESA profiles and related trace metals in four groups: post-clozapine agranulocytosis (POST CLOZ AGRAN) (N = 9); clozapine no agranulocytosis (CLOZ NO AGRAN) (N = 12); West Coast controls (WC CONTROLS) (N = 14); and Long Island Jewish Medical Center controls (LIJ CONTROLS) (N = 12). Glutathione peroxidase (GSH-Px, P1) levels in plasma were slowest in the POST CLOZ AGRAN group (34.3 +/- 6.9 IU/dl [standard deviation; SD]; p < 0.002); red blood cell glutathione peroxidase (GSH-Px, RBC) was highest in the WC CONTROLS (38.7 +/- 4.7 IU/g hemoglobin [Hgb]; p < 0.008); and selenium (SE) levels in plasma were lower in both the POST CLOZ AGRAN group (111.6 +/- 14.7 ng/ml) and the CLOZ NO AGRAN group(115.0 +/- 17.8) than in the WC CONTROLS (142.5 +/- 18.3; p < 0.0006). SE was also lower in the POST CLOZ AGRAN group than in the LIJ CONTROLS (129.1 +/- 21.6; p < 0.04). The presence of at least one of the following: (1) GSH-Px, P1 < 37.6 IU/dl; (2) GSH-Px, RBC < 31.0 IU/g Hgb; or (3) SE < 112.4 ng/ml, distinguished POST CLOZ AGRAN subjects from the WC CONTROLS, but not from the LIJ CONTROLS. Data from this cross-sectional pilot study suggest that abnormalities in the body's antioxidant defense system may be involved in the pathogenesis of clozapine-associated agranulocytosis. If confirmed in large-scale, prospective studies, these preliminary findings have potential clinical application in the screening and prophylaxis of clozapine agranulocytosis.

  18. TU-CD-303-02: Beyond Radiation Induced Double Strand Breaks - a New Horizon for Radiation Therapy Research

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S. [UNC School of Medicine (United States)

    2015-06-15

    Recent advances in cancer research have shed new light on the complex processes of how therapeutic radiation initiates changes at cellular, tissue, and system levels that may lead to clinical effects. These new advances may transform the way we use radiation to combat certain types of cancers. For the past two decades many technological advancements in radiation therapy have been largely based on the hypothesis that direct radiation-induced DNA double strand breaks cause cell death and thus tumor control and normal tissue damage. However, new insights have elucidated that in addition to causing cellular DNA damage, localized therapeutic radiation also initiates cascades of complex downstream biological responses in tissue that extend far beyond where therapeutic radiation dose is directly deposited. For instance, studies show that irradiated dying tumor cells release tumor antigens that can lead the immune system to a systemic anti-cancer attack throughout the body of cancer patient; targeted irradiation to solid tumor also increases the migration of tumor cells already in bloodstream, the seeds of potential metastasis. Some of the new insights may explain the long ago discovered but still unexplained non-localized radiation effects (bystander effect and abscopal effect) and the efficacy of spatially fractionated radiation therapy (microbeam radiation therapy and GRID therapy) where many “hot” and “cold” spots are intentionally created throughout the treatment volume. Better understanding of the mechanisms behind the non-localized radiation effects creates tremendous opportunities to develop new and integrated cancer treatment strategies that are based on radiotherapy, immunology, and chemotherapy. However, in the multidisciplinary effort to advance new radiobiology, there are also tremendous challenges including a lack of multidisciplinary researchers and imaging technologies for the microscopic radiation-induced responses. A better grasp of the essence of

  19. Radiation-induced Chondrosarcoma of the Bladder. Case Report and Review of Literature.

    Science.gov (United States)

    Sule, Norbert; Xu, B O; El Zein, Dima; Szigeti, Kinga; George, Saby; Kane, John M; Cheney, Richard

    2015-05-01

    Chondrosarcoma of the bladder is an extremely rare disease. Only five previously described cases are known in the medical literature. We present a chondrosarcoma developed 19 years after radiation treatment in a 73-year-old patient. A literature search of articles published from 1984 to 2014 was performed. This is the first reported case of post-radiation bladder chondrosarcoma. We compared the clinicopathological features of the previously reported cases and reviewed the medical literature of the bladder sarcomas and post-radiation sarcomas. The primary treatment for bladder mesenchymal neoplasms is surgical, preferably radical cystectomy with or without chemotherapy. Positive surgical margin is one of the most important factors negatively affecting disease-specific, recurrence-free and overall survival rates. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  20. ATM Mutations and the Development of Severe Radiation-Induced Morbidity Following Radiotherapy for Breast Cancer

    National Research Council Canada - National Science Library

    Rosenstein, Barry

    2003-01-01

    ... of this project are to (1) screen 50 breast cancer patients for a ATM mutations who developed radiation-induced grade 3/4 late subcutaneous tissue morbidity as defined by the RTOG/EORTC scoring scheme, (2...

  1. Radiation-Induced Processing of Hydrocarbons in Environments Relevant to Pluto

    National Research Council Canada - National Science Library

    Gallagher, Robert

    2001-01-01

    An understanding of the formation of the larger molecules in the outer solar system, by radiation induced processing of more primitive constituents, has implications relating to the evolution of the solar system...

  2. The protective effects of trace elements against side effects induced by ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hosseinimehr, Seyed Jaial [Dept. of Radiopharmacy, Faculty of Pharmacy, Pharmaceutical Sciences Research Center, Mazandaran University of Medical Sciences, Sari (Iran, Islamic Republic of)

    2015-06-15

    Trace elements play crucial role in the maintenance of genome stability in the cells. Many endogenous defense enzymes are containing trace elements such as superoxide dismutase and metalloproteins. These enzymes are contributing in the detoxification of reactive oxidative species (ROS) induced by ionizing radiation in the cells. Zinc, copper, manganese, and selenium are main trace elements that have protective roles against radiation-induced DNA damages. Trace elements in the free salt forms have protective effect against cell toxicity induced by oxidative stress, metal-complex are more active in the attenuation of ROS particularly through superoxide dismutase mimetic activity. Manganese-complexes in protection of normal cell against radiation without any protective effect on cancer cells are more interesting compounds in this topic. The aim of this paper to review the role of trace elements in protection cells against genotoxicity and side effects induced by ionizing radiation.

  3. Radiation induced cell loss in rat submandibular gland and its relation to gland function

    NARCIS (Netherlands)

    Zeilstra, LJW; Vissink, A; Konings, AWT; Coppes, RP

    Purpose: To understand early and late radiation-induced loss of function of the submandibular gland, changes in cell number were documented and correlated with data on gland function. Modulation of the radiation effect by sialogogues was used to investigate possible mechanisms of action. Materials

  4. Short and long term radiation induced cardiovascular disease in patients with cancer

    DEFF Research Database (Denmark)

    Nielsen, Kirsten Melgaard; Offersen, Birgitte Vrou; Nielsen, Hanne Melgaard

    2017-01-01

    Radiation-induced cardiovascular disease is well described as a late effect in cancer patients treated with radiation therapy. Advancements in surgery, radiotherapy, and chemotherapy have led to an increasing number of cancer survivors with resultant long-term side effects related to their cancer...

  5. Comparison of three rat strains for development of radiation-induced lung injury after hemithoracic irradiation

    NARCIS (Netherlands)

    van Eerde, MR; Kampinga, HH; Szabo, BG; Vujaskovic, Z

    The purpose of this study is to define differences in radiation sensitivity among rat strains using breathing frequency and lung perfusion as end points of radiation-induced lung injury. The results have confirmed previous findings in mice showing that-under stringently controlled iso-dose/volume

  6. A Prospective Cohort Study on Radiation-induced Hypothyroidism : Development of an NTCP Model

    NARCIS (Netherlands)

    Boomsma, Marjolein J.; Bijl, Hendrik P.; Christianen, Miranda E. M. C.; Beetz, Ivo; Chouvalova, Olga; Steenbakkers, Roel J. H. M.; van der Laan, Bernard F. A. M.; Wolffenbuttel, Bruce H. R.; Oosting, Sjoukje F.; Schilstra, Cornelis; Langendijk, Johannes A.

    2012-01-01

    Purpose: To establish a multivariate normal tissue complication probability (NTCP) model for radiation-induced hypothyroidism. Methods and Materials: The thyroid-stimulating hormone (TSH) level of 105 patients treated with (chemo-) radiation therapy for head-and-neck cancer was prospectively

  7. The sensitivity of laser induced fluorescence instruments at low pressure to RO2 radicals and the use of this detection method to determine the yield of HO2 during OH-initiated isoprene oxidation

    Science.gov (United States)

    Heard, D. E.; Whalley, L. K.; Blitz, M. A.; Seakins, P. W.

    2011-12-01

    Ambient measurements of HO2 have almost exclusively been made by chemical titration of HO2 to OH by NO and the subsequent detection of the OH radical using laser induced fluorescence (LIF) at low pressures (~ 1 Torr) (Heard and Pilling, 2003). Until recently it was assumed that higher peroxy radicals (RO2) could not act as an HO2 interference in LIF because although these species also react with NO to form an alkoxy radical (RO) at 1 Torr the subsequent reaction RO + O2 to give HO2 is too slow. Independent laboratory studies conducted at the University of Leeds, UK and at the Forschungzentrum, Julich, Germany (Fuchs et al., 2011), however, have revealed that alkene-derived RO2 radicals and longer chain alkane-derived RO2 (>C3) are able to rapidly convert to HO2 in the presence of NO in a LIF detection cell. The yield of HO2 from a range of different RO2 species has been determined in Leeds and in the most part these yields agree well with model predictions based on the Master Chemical Mechanism (http://mcm.leeds.ac.uk/MCM/). For ethene and isoprene derived RO2 species, the relative sensitivity was found to be close to 100% with respect to that for HO2. The sensitivity of different LIF instruments/LIF operating conditions to this interference has been found to be highly variable, however. Under the operating conditions employed during the 2008 OP3 campaign that took place in the Borneo rainforest, the University of Leeds ground-based LIF instrument was not sensitive to detection of these RO2 species. The high pumping capacity of the system coupled with poor mixing of NO into the ambient air-stream for the titration of HO2 to OH effectively minimised this potential interference. Using the ground-based LIF detection cell coupled to a flow-tube, experiments to determine the time-resolved yield of HO2 radicals during the OH-initiated oxidation of isoprene have been conducted. OH was generated by photolysis of t-butyl-hydro-peroxide by 254 nm radiation from a Hg lamp in

  8. 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

  9. Identification of novel senescence-associated genes in ionizing radiation-induced senescent carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Seon; Kim, Bong Cho; Han, Na Kyung; Hong, Mi Na; Park, Su Min; Yoo, Hee Jung [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Chu, In Sun [Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); Lee, Sun Hee [Dong-A University, Busan (Korea, Republic of)

    2009-05-15

    Cellular senescence is considered as a defense mechanism to prevent tumorigenesis. Ionizing radiation (IR) induces stress-induced premature senescence as well as apoptosis in various cancer cells. Senescent cells undergo functional and morphological changes including large and flattened cell shape, senescence-associated {beta}-galactosidase (SA-{beta}Gal) activity, and altered gene expressions. Even with the recent findings of several gene expression profiles and supporting functional data, it is obscure that mechanism of IR-induced premature senescence in cancer cells. We performed microarray analysis to identify the common regulated genes in ionizing radiation-induced prematurely senescent human carcinoma cell lines.

  10. Radiation-induced dedifferentiated chondrosarcoma with orbital invasion.

    Science.gov (United States)

    Davies, Brett W; Prescott, Christina R; Said, Sherif A; Campana, John; Attié-Castro, Flávia A; Velasco E Cruz, Antonio Augusto; Durairaj, Vikram D

    2014-01-01

    To report 2 interventional cases of dedifferentiated chondrosarcoma with orbital involvement after radiotherapy performed in childhood and to review the literature on chondrosarcoma in the orbit following radiation treatment. Retrospective analysis of medical records of 2 patients with chondrosarcoma of the orbits with review of the literature. The first patient developed chondrosarcoma of the orbital and maxillary sinus 36 years after external beam radiation therapy to the OS to treat retinoblastoma. The second patient developed a large orbital chondrosarcoma 35 years after external beam radiation therapy in the treatment of craniofacial fibrous dysplasia. These cases highlight the risk of secondary chondrosarcoma in patients following radiotherapy and the importance of lifetime monitoring.

  11. Determination of the yield of radiation-induced peroxidation of sodium linoleate in aqueous monomeric and micellar solutions.

    Science.gov (United States)

    Hauville, C; Rémita, S; Thérond, P; Rouscilles, A; Couturier, M; Jore, D; Gardès-Albert, M

    1998-11-01

    Peroxidation of polyunsaturated fatty acids such as linoleic acid in aqueous micellar solution proceeds through a free-radical chain mechanism and is accompanied by the formation of conjugated dienes, some in the form of hydroperoxides. In the course of an investigation of radiation-induced oxidation of aqueous sodium linoleate, we have measured three indexes of peroxidation-conjugated dienes, hydroperoxides and thiobarbituric acid-reactive substances-by means of absorption spectroscopy, high-pressure liquid chromatography and spectrofluorimetry, respectively. There are linear correlations between the amounts of conjugated dienes, hydroperoxides and thiobarbituric acid-reactive substances. The radiolytic yields have been determined from the radiation dose dependence of the three markers of peroxidation as a function of sodium linoleate concentration. The results obtained indicate a strong effect of the concentrations of oxygen and linoleate on the yields of the products. The yields at different lipid concentrations display a large increase in chain propagation length; this is discussed in terms of the effect of micellar size.

  12. 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

  13. Vitamin D Deficiency Is Associated With the Severity of Radiation-Induced Proctitis in Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Ghorbanzadeh-Moghaddam, Amir [Medical Student' s Research Center, Isfahan University of Medical Sciences, Isfahan (Iran, Islamic Republic of); Gholamrezaei, Ali, E-mail: Gholamrezaei@med.mui.ac.ir [Medical Student' s Research Center, Isfahan University of Medical Sciences, Isfahan (Iran, Islamic Republic of); Poursina Hakim Research Institution, Isfahan (Iran, Islamic Republic of); Hemati, Simin [Department of Radiotherapy Oncology, Isfahan University of Medical Sciences, Isfahan (Iran, Islamic Republic of)

    2015-07-01

    Purpose: Radiation-induced injury to normal tissues is a common complication of radiation therapy in cancer patients. Considering the role of vitamin D in mucosal barrier hemostasis and inflammatory responses, we investigated whether vitamin D deficiency is associated with the severity of radiation-induced acute proctitis in cancer patients. Methods and Materials: This prospective observational study was conducted in cancer patients referred for pelvic radiation therapy. Serum concentration of 25-hydroxyvitamin D was measured before radiation therapy. Vitamin D deficiency was defined as 25-hydroxyvitamin D concentrations of <35 nmol/L and <40 nmol/L in male and female patients, respectively, based on available normative data. Acute proctitis was assessed after 5 weeks of radiation therapy (total received radiation dose of 50 Gy) and graded from 0 to 4 using Radiation Therapy Oncology Group (RTOG) criteria. Results: Ninety-eight patients (57.1% male) with a mean age of 62.8 ± 9.1 years were studied. Vitamin D deficiency was found in 57 patients (58.1%). Symptoms of acute proctitis occurred in 72 patients (73.4%) after radiation therapy. RTOG grade was significantly higher in patients with vitamin D deficiency than in normal cases (median [interquartile range] of 2 [0.5-3] vs 1 [0-2], P=.037). Vitamin D deficiency was associated with RTOG grade of ≥2, independent of possible confounding factors; odds ratio (95% confidence interval) = 3.07 (1.27-7.50), P=.013. Conclusions: Vitamin D deficiency is associated with increased severity of radiation-induced acute proctitis. Investigating the underlying mechanisms of this association and evaluating the effectiveness of vitamin D therapy in preventing radiation-induced acute proctitis is warranted.

  14. Radiation-Induced Immune Modulation in Prostate Cancer

    National Research Council Canada - National Science Library

    McBride, William H

    2006-01-01

    ... into the generation of tumor-specific immunity so as to achieve the best therapeutic outcome from radiation therapy. From the conventional point of view radiotherapy is usually related to cell killing...

  15. Low dose ionizing radiation induced acoustic neuroma: A putative link?

    Directory of Open Access Journals (Sweden)

    Sachin A Borkar

    2012-01-01

    Full Text Available Although exposure to high dose ionizing radiation (following therapeutic radiotherapy has been incriminated in the pathogenesis of many brain tumors, exposure to chronic low dose ionizing radiation has not yet been shown to be associated with tumorigenesis. The authors report a case of a 50-year-old atomic reactor scientist who received a cumulative dose of 78.9 mSv over a 10-year period and was detected to have an acoustic neuroma another 15 years later. Although there is no proof that exposure to ionizing radiation was the cause for the development of the acoustic neuroma, this case highlights the need for extended follow-up periods following exposure to low dose ionizing radiation.

  16. The potential benefits of nicaraven to protect against radiation-induced injury in hematopoietic stem/progenitor cells with relative low dose exposures

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Haytham [Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523 (Japan); Department of Medical Physiology and Cell Biology, Qena Faculty of Medicine, South Valley University (Egypt); Galal, Omima [Department of Medical Physiology and Cell Biology, Qena Faculty of Medicine, South Valley University (Egypt); Urata, Yoshishige; Goto, Shinji; Guo, Chang-Ying; Luo, Lan [Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523 (Japan); Abdelrahim, Eman [Department of Medical Histology, Qena Faculty of Medicine, South Valley University (Egypt); Ono, Yusuke [Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523 (Japan); Mostafa, Emtethal [Department of Medical Physiology and Cell Biology, Qena Faculty of Medicine, South Valley University (Egypt); Li, Tao-Sheng, E-mail: litaoshe@nagasaki-u.ac.jp [Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523 (Japan)

    2014-09-26

    Highlights: • Nicaraven mitigated the radiation-induced reduction of c-kit{sup +} stem cells. • Nicaraven enhanced the function of hematopoietic stem/progenitor cells. • Complex mechanisms involved in the protection of nicaraven to radiation injury. - Abstract: Nicaraven, a hydroxyl radical-specific scavenger has been demonstrated to attenuate radiation injury in hematopoietic stem cells with 5 Gy γ-ray exposures. We explored the effect and related mechanisms of nicaraven for protecting radiation injury induced by sequential exposures to a relatively lower dose γ-ray. C57BL/6 mice were given nicaraven or placebo within 30 min before exposure to 50 mGy γ-ray daily for 30 days in sequences (cumulative dose of 1.5 Gy). Mice were victimized 24 h after the last radiation exposure, and the number, function and oxidative stress of hematopoietic stem cells were quantitatively estimated. We also compared the gene expression in these purified stem cells from mice received nicaraven and placebo treatment. Nicaraven increased the number of c-kit{sup +} stem/progenitor cells in bone marrow and peripheral blood, with a recovery rate around 60–90% of age-matched non-irradiated healthy mice. The potency of colony forming from hematopoietic stem/progenitor cells as indicator of function was completely protected with nicaraven treatment. Furthermore, nicaraven treatment changed the expression of many genes associated to DNA repair, inflammatory response, and immunomodulation in c-kit{sup +} stem/progenitor cells. Nicaraven effectively protected against damages of hematopoietic stem/progenitor cells induced by sequential exposures to a relatively low dose radiation, via complex mechanisms.

  17. [A case of prednisolone therapy for radiation-induced hemorrhagic cystitis].

    Science.gov (United States)

    Yanagi, Masato; Nishimura, Taiji; Kurita, Susumu; Lee, Chorsu; Kondo, Yukihiro; Yamazaki, Keiichi

    2011-05-01

    Hemorrhagic cystitis resulting from radiation to pelvic visceral malignant lesions often might be incurable and there have been no established definitive treatment. We experienced a case with severe radiation-induced hemorrhagic cystitis refractory to conventional therapy. The treatment with oral administration of prednisolone was performed and obtained a successful result. Gross hematuria disappeared in 2 weeks in this case. This experience suggested that oral administration of prednisolone could be considered the treatment for patients with radiation-induced hemorrhagic cystitis when usual treatments including transurethral electro-coagulation are unsuccessful.

  18. Hyperbaric oxygen therapy in the successful treatment of two cases of radiation-induced hemorrhagic cystitis

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, Akihito; Ohkubo, Yuhei; Takashima, Rikiya; Furugen, Nobuaki; Tochimoto, Masato; Tsuchiya, Akira (Tokyo Medical Coll. (Japan). Kasumigaura Hospital)

    1994-08-01

    Hemorrhagic cystitis resulting from radiation to pelvic visceral malignant lesions often might be incurable and there have been established no definitive treatment. We experienced 2 cases of radiation-induced severe hemorrhagic cystitis refractory to conventional therapy. The treatment with hyperbaric oxygen to control hematuria was performed and obtained successful results. Gross hematuria was disappeared and cystoscopic figure was remarkably improved. No remarkable side-effect was observed in both patients. This experience suggested that hyperbaric oxygen could be considered as the primary treatment for patient with radiation-induced hemorrhagic cystitis instead of usual treatment. (author).

  19. Low-Dose Bevacizumab Is Effective in Radiation-Induced Necrosis

    Directory of Open Access Journals (Sweden)

    Matheus Alessandretti

    2013-12-01

    Full Text Available Background: Radiation-induced necrosis is a complication of brain irradiation. Treatment options are limited. Methods: The response to treatment with low-dose bevacizumab in 2 patients with radiation-induced necrosis was reported. Results: Both patients with metastatic melanoma, aged 48 and 51 years, had significant symptomatic and radiological improvement with low-dose bevacizumab treatment. Doses as low as 5 mg/kg every 6 weeks and 7.5 mg/kg i.v. every 4 weeks were used and were highly effective. Conclusions: Low-dose bevacizumab is a solid option in the management of edema associated with radiation necrosis.

  20. Analysis behaviour of free radicals produced by ionizing radiations in human blood by EPR for biological dosimetry in patients; Analisis del comportamiento de los radicales libre en la radiolisis de la sangre por EPR para dosimetria biologia en pacientes

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza, O. O.; Almanza, A.; Plazas, M. M. C.

    2006-07-01

    In this work is analyzed the biological dosimetry of the free radicals produced by ionizing radiations in human blood obtained by EPR and the biological behaviour of samples In-Vitro, with Rh: O+, in tubes with EDTA (Acid Etilen Diamino Tetracetic) the samples was extracted of the main investigator, these samples were radiated with gammas of ''60Co of a Theratron 780 between plates of PMMA to a depth of Z{sub m}ax of 0.5 cm and between doses 1 to 25 Gy. In these results the behaviors of signal the free radicals presented a increasing a their intensity depending on applied dose, of equal way are results of the biologic dosimetry displayed in sanguineous populations like. White Globules, Red. Platelets etc, to being compared with Resonance Paramagnetic Electronic (EPR). The results show changes in sanguineous populations in high doses (D>10 Gy) in the case of lymphocytes, granulocitos, macusanita, plaquetas, hemoglobina, haematocrit with change similarly in medium and low doses (D>10Gy) in linfocites, platelets, granulocytes, monocytes and the haematocrit. A sanguineous sample without radiating analyzes by EPR giving the presence of signals with values of g=2.13 2,41 in blood. For the first certain value of g authors have associated it to free radicals like: globin (Fe(IV)=0) or Cu''+ incorporated to the ceruloplasmin molecule. (Author)

  1. The potential benefits of nicaraven to protect against radiation-induced injury in hematopoietic stem/progenitor cells with relative low dose exposures.

    Science.gov (United States)

    Ali, Haytham; Galal, Omima; Urata, Yoshishige; Goto, Shinji; Guo, Chang-Ying; Luo, Lan; Abdelrahim, Eman; Ono, Yusuke; Mostafa, Emtethal; Li, Tao-Sheng

    2014-09-26

    Nicaraven, a hydroxyl radical-specific scavenger has been demonstrated to attenuate radiation injury in hematopoietic stem cells with 5Gy γ-ray exposures. We explored the effect and related mechanisms of nicaraven for protecting radiation injury induced by sequential exposures to a relatively lower dose γ-ray. C57BL/6 mice were given nicaraven or placebo within 30min before exposure to 50mGy γ-ray daily for 30days in sequences (cumulative dose of 1.5Gy). Mice were victimized 24h after the last radiation exposure, and the number, function and oxidative stress of hematopoietic stem cells were quantitatively estimated. We also compared the gene expression in these purified stem cells from mice received nicaraven and placebo treatment. Nicaraven increased the number of c-kit(+) stem/progenitor cells in bone marrow and peripheral blood, with a recovery rate around 60-90% of age-matched non-irradiated healthy mice. The potency of colony forming from hematopoietic stem/progenitor cells as indicator of function was completely protected with nicaraven treatment. Furthermore, nicaraven treatment changed the expression of many genes associated to DNA repair, inflammatory response, and immunomodulation in c-kit(+) stem/progenitor cells. Nicaraven effectively protected against damages of hematopoietic stem/progenitor cells induced by sequential exposures to a relatively low dose radiation, via complex mechanisms. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Advances in dosimetry and biological predictors of radiation-induced esophagitis

    Directory of Open Access Journals (Sweden)

    Yu Y

    2016-01-01

    Full Text Available Yang Yu,1 Hui Guan,1 Yuanli Dong,1 Ligang Xing,2 Xiaolin Li2 1School of Medicine and Life Sciences, Shandong Academy of Medical Sciences, University of Jinan, Jinan, 2Department of Radiation Oncology, Shandong Cancer Hospital, Jinan, Shandong Province, People’s Republic of China Objective: To summarize the research progress about the dosimetry and biological predictors of radiation-induced esophagitis.Methods: We performed a systematic literature review addressing radiation esophagitis in the treatment of lung cancer published between January 2009 and May 2015 in the PubMed full-text database index systems.Results: Twenty-eight eligible documents were included in the final analysis. Many clinical factors were related to the risk of radiation esophagitis, such as elder patients, concurrent chemoradiotherapy, and the intense radiotherapy regimen (hyperfractionated radiotherapy or stereotactic body radiotherapy. The parameters including Dmax, Dmean, V20, V30, V50, and V55 may be valuable in predicting the occurrence of radiation esophagitis in patients receiving concurrent chemoradiotherapy. Genetic variants in inflammation-related genes are also associated with radiation-induced toxicity.Conclusion: Dosimetry and biological factors of radiation-induced esophagitis provide clinical information to decrease its occurrence and grade during radiotherapy. More prospective studies are warranted to confirm their prediction efficacy. Keywords: lung cancer, esophagitis, radiation injuries, predictors

  3. High-LET radiation-induce malignant and benign tumors in rat skin

    Energy Technology Data Exchange (ETDEWEB)

    Burns, F.J. [Institute of Environmental Medicine, New York University Medical Center, New York, NY (United States); Zhao, P.; Hiz, Z.; Chen, S.; Roy, N.

    1999-03-01

    In the multistage theory of carcinogenesis, cells progress to cancer through a series of mutations in cancer-relevant genes, and sometimes the intermediate stages become benign neoplastic lesions. Although cancer induction by low LET radiation is subject to repair or recovery in the sense that multiple exposures produce fewer cancers than the same single dose, this recovery is not seen following exposure to high LET radiation. Data are presented on squamous and basal cell carcinoma and fibroma induction in rat skin exposed to: 1. an electron beam (LET=0.34 kV/{mu}), 2. a neon ion beam (LET=30 kV/{mu} ) and 3. an argon ion beam (LET=125 kV/{mu}). Cancer yields were fitted by a LET-dependent quadratic equation, and equation parameters were estimated by regression analysis for each type of radiation. The results are consistent with the interpretation that carcinoma induction can be explained by a pathway involving 2 radiation-induced events, 1 radiation-induced mutation and 1 spontaneous mutation, while benign fibromas can be explained by a pathway involving 1 radiation-induced event and 1 radiation-induced mutation. (author)

  4. 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. 

  5. Bystander effect induced by UV radiation; why should we be interested?

    Science.gov (United States)

    Widel, Maria

    2012-11-14

    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. 

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

    Science.gov (United States)

    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

    2007-04-06

    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 15Gy radiation. In mice exposed to 5Gy 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.

  8. Effective formalin treatment of two cases of radiation-induced hemorrhagic colitis

    Energy Technology Data Exchange (ETDEWEB)

    Ietsugu, Kenichi; Kosugi, Mitsuyo; Nakashima, Hisayuki; Sakatoku, Mitsuaki; Bando, Hiroyuki; Sunohara, Tetsuyuki [Tonami General Hospital, Toyama (Japan)

    1999-02-01

    Radiation colitis sometimes shows uncontrollable bleeding. The treatment by 4 percent formalin solution was effective for two cases of radiation-induced hemorrhagic colitis. Case 1 was an 80-year-old female who had cloacogenic carcinoma, poorly-differentiated squamous cell carcinoma type. This was complicated by hemorrhagic proctitis 16 months after radiation therapy. Bleeding could not be controlled by steroid enema and endoscopic laser therapy. Formalin treatment was very effective for hemostasis. Case 2 was 47-year-old female who had breast cancer with multiple bone metastases. This was complicated by hemorrhagic colitis 15 months after radiation therapy of bone metastases of the lumbar spine and the sacrum. Three formalin treatments were needed for hemostasis, however, they were effective. The formalin treatment is a simple, effective and minimally invasive therapy for radiation-induced hemorrhagic colitis of the lower sigmoid colon and the rectum. (author)

  9. Management of late radiation-induced rectal injury after treatment of carcinoma of the uterus

    Energy Technology Data Exchange (ETDEWEB)

    Allen-Mersh, T.G.; Wilson, E.J.; Hope-Stone, H.F.; Mann, C.V.

    1987-06-01

    Sixty-one of 1418 (4.3 per cent) patients treated with radiation for carcinoma of the uterus from 1963 to 1983 had significant radiation-induced complications of the intestine develop which required a surgical opinion considering further management. Ninety-three per cent of these complications involved the rectum. Florid proctitis resolved within two years of onset in 33 per cent of the patients who were managed conservatively while 22 per cent of the patients died of disseminated disease within the same time period. Surgical treatment was eventually necessary in 39 per cent of the patients who were initially treated conservatively for radiation induced proctitis. Rectal excision with coloanal sleeve anastomosis produced a satisfactory result in eight of 11 patients with severe radiation injury involving the rectum. The incidence of radiation-induced and malignant rectovaginal fistula were similar (1 per cent), but disease-induced symptoms tended to occur earlier after primary treatment (a median of eight months) compared with radiation-induced symptoms (a median of 16 months).

  10. Adenosine kinase inhibition protects against cranial radiation-induced cognitive dysfunction

    Directory of Open Access Journals (Sweden)

    Munjal M Acharya

    2016-06-01

    Full Text Available Clinical radiation therapy for the treatment of CNS cancers leads to unintended and debilitating impairments in cognition. Radiation-induced cognitive dysfunction is long lasting, however, the underlying molecular and cellular mechanisms are still not well established. Since ionizing radiation causes microglial and astroglial activation, we hypothesized that maladaptive changes in astrocyte function might be implicated in radiation-induced cognitive dysfunction. Among other gliotransmitters, astrocytes control the availability of adenosine, an endogenous neuroprotectant and modulator of cognition, via metabolic clearance through adenosine kinase (ADK. Adult rats exposed to cranial irradiation (10 Gy showed significant declines in performance of hippocampal-dependent cognitive function tasks (novel place recognition, novel object recognition, and contextual fear conditioning 1 month after exposure to ionizing radiation using a clinically relevant regimen. Irradiated rats spent less time exploring a novel place or object. Cranial irradiation also led to reduction in freezing behavior compared to controls in the fear conditioning task. Importantly, immunohistochemical analyses of irradiated brains showed significant elevation of ADK immunoreactivity in the hippocampus that was related to astrogliosis and increased expression of glial fibrillary acidic protein (GFAP. Conversely, rats treated with the ADK inhibitor 5-iodotubercidin (5-ITU, 3.1 mg/kg, i.p., for 6 days prior to cranial irradiation showed significantly improved behavioral performance in all cognitive tasks 1 month post exposure. Treatment with 5-ITU attenuated radiation-induced astrogliosis and elevated ADK immunoreactivity in the hippocampus. These results confirm an astrocyte-mediated mechanism where preservation of extracellular adenosine can exert neuroprotection also against radiation-induced pathology. These innovative findings link radiation-induced changes in cognition and CNS

  11. Refining the American Urological Association and American Society for Radiation Oncology guideline for adjuvant radiotherapy after radical prostatectomy using the pathologic Gleason score

    Directory of Open Access Journals (Sweden)

    Wan Song

    2017-01-01

    Full Text Available Recently, it has been suggested that the guideline for adjuvant radiotherapy (ART following radical prostatectomy (RP sponsored by the American Urological Association and American Society for Radiation Oncology (AUA/ASTRO may result in a significant overtreatment. Thus, the objective of the present study was to refine the AUA/ASTRO guideline for ART in patients at risk for biochemical recurrence (BCR after RP. To this end, we reviewed our prospectively maintained database and selected 193 patients who met the AUA/ASTRO ART criteria. With a median follow-up of 24.0 months, BCR rate was 17.6% (34/193. When stratified by the Gleason score, BCR rate in men with Gleason score 6 was 6.8%. There was no significant association between BCR-free survival and surgical margin (P = 0.690 and pathologic stage (P = 0.353 in patients with the Gleason score 6. However, in patients with positive surgical margins (PSMs/pathologic stage ≥T3, there was a significant difference in BCR-free survival according to Gleason score (≤ 7 vs 8-10, P = 0.047. Multivariate Cox regression analysis demonstrated that pathologic stage ≥T3 (HR = 2.106; P= 0.018, PSMs (HR = 2.411; P= 0.003, and pathologic Gleason score 8-10 (HR = 4.715; P< 0.001 were independent predictors of BCR after RP. Therefore, in addition to pathologic stage ≥T3 and PSMs, Gleason score 8-10 predicts BCR after RP. In patients with Gleason score 6, observation rather than ART may be more appropriate regardless of stage and surgical margin status.

  12. Refining the American Urological Association and American Society for Radiation Oncology guideline for adjuvant radiotherapy after radical prostatectomy using the pathologic Gleason score.

    Science.gov (United States)

    Song, Wan; Kwon, Young Suk; Jeon, Seong Soo; Kim, Isaac Yi

    2017-01-01

    Recently, it has been suggested that the guideline for adjuvant radiotherapy (ART) following radical prostatectomy (RP) sponsored by the American Urological Association and American Society for Radiation Oncology (AUA/ASTRO) may result in a significant overtreatment. Thus, the objective of the present study was to refine the AUA/ASTRO guideline for ART in patients at risk for biochemical recurrence (BCR) after RP. To this end, we reviewed our prospectively maintained database and selected 193 patients who met the AUA/ASTRO ART criteria. With a median follow-up of 24.0 months, BCR rate was 17.6% (34/193). When stratified by the Gleason score, BCR rate in men with Gleason score 6 was 6.8%. There was no significant association between BCR-free survival and surgical margin (P = 0.690) and pathologic stage (P = 0.353) in patients with the Gleason score 6. However, in patients with positive surgical margins (PSMs)/pathologic stage ≥T3, there was a significant difference in BCR-free survival according to Gleason score (≤ 7 vs 8-10, P = 0.047). Multivariate Cox regression analysis demonstrated that pathologic stage ≥T3 (HR = 2.106; P= 0.018), PSMs (HR = 2.411; P= 0.003), and pathologic Gleason score 8-10 (HR = 4.715; PGleason score 8-10 predicts BCR after RP. In patients with Gleason score 6, observation rather than ART may be more appropriate regardless of stage and surgical margin status.

  13. 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

  14. Effect of mobile phone radiation on pentylenetetrazole-induced seizure threshold in mice

    Directory of Open Access Journals (Sweden)

    Ebrahim Kouchaki

    2016-07-01

    Full Text Available Objective(s: Scientific interest in potential mobile phone impact on human brain and performance has significantly increased in recent years. The present study was designed to evaluate the effects of mobile phone radiation on seizure threshold in mice. Materials and methods:BALB/c male mice were randomly divided into three groups: control, acute, and chronic mobile phone radiation for 30, 60, and 90 min with frequency 900 to 950 MHz and pulse of 217 Hz. The chronic group received 30 days of radiation, while the acute group received only once. The intravenous infusion of pentylenetetrazole (5 mg/ml was used to induce seizure signs. Results:  Although acute mobile radiation did not change seizure threshold, chronic radiation decreased the clonic and tonic seizure thresholds significantly. Conclusion: Our data suggests that thecontinued and prolonged contact with the mobile phone radiation might increase the risk of seizure attacks and should be limited.

  15. Temporary hyposalivation induced by radiation therapy in a child; Forbigaaende straaleindusert hyposalivasjon hos barnepasient

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, J.L. [Oslo Univ., Oslo (Norway); Langberg, C.W. [Ullevaal Sykehus, Oslo (Norway)

    1997-09-01

    This case report deals with the diagnosis and treatment of hyposalivation after radical radiation therapy and cytotoxic treatment of a metastasising nasopharyngeal carcinoma in an eight-year old girl. After cancer treatment the patient suffered from xerostomia, and pronounced hyposalivation was demonstrated. Frequent chewing of sugar-free gum and use of lozenges was recommended, and the patient was followed up for one year. During this time, the values for unstimulated whole saliva increased by a factor of five, and stimulated whole saliva values increased as well, but less so. Two years after cancer treatment, the patient no longer suffers from xerostomia. 13 refs., 2 figs.

  16. The effects of polaprezinc on radiation-induced taste alterations

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Katsumasa; Togao, Osamu [Kyushu Univ., Fukuoka (Japan). Graduate School of Medical Sciences; Shikama, Naoto (and others)

    2001-06-01

    The effects of polaprezinc (an insoluble zinc complex of L-carnosine) on taste abnormalities were investigated in 22 patients receiving radiation therapy to head and neck malignancies. The total doses to the tongue were 25.5-46.0 Gy (mean, 37.9 Gy). All patients received 75 mg of polaprezinc two times a day with an interval of 0-1,561 days (mean, 305.3 days) after the completion of radiation therapy. The duration of the drug administration was 25-353 days (mean, 96.9 days). Twenty patients (90.9%) were aware of an improvement of a partial or complete loss of taste. Polaprezinc is effective in improving loss of taste after radiation therapy. (author)

  17. Validation of genetic predictors of late radiation-induced morbidity in prostate cancer patients

    DEFF Research Database (Denmark)

    Schack, Line M H; Petersen, Stine E; Nielsen, Steffen

    2017-01-01

    in 96 patients (rs2788612, rs1800629, rs264663, rs2682585, rs2268363, rs1801516, rs13035033, rs7120482 and rs17779457). A validated gene expression profile predictive of resistance to radiation-induced skin fibrosis was tested in 42 patients. An RT-induced anorectal dysfunction score (RT-ARD) served...

  18. SU-G-TeP3-10: Radiation Induces Prompt Live-Cell Metabolic Fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Campos, D [University of Wisconsin Madison, Madison, WI (United States); Peeters, W; Bussink, J [Radboud University Medical Center, Nijmegen, GA (United States); Nickel, K [University of Wisconsin - Madison, Madison, Wisconsin (United States); Burkel, B; Kimple, R; Kogel, A van der; Eliceiri, K [University of Wisconsin - Madison, Madison, WI (United States); Kissick, M [University of Wisconsin, Madison, WI (United States)

    2016-06-15

    Purpose: To compare metabolic dynamics and HIF-1α expression following radiation between a cancerous cell line (UM-SCC-22B) and a normal, immortalized cell line, NOK (Normal Oral Keratinocyte). HIF-1 is a key factor in metabolism and radiosensitivity. A better understanding of how radiation affects the interplay of metabolism and HIF-1 might give a better understanding of the mechanisms responsible for radiosensitivity. Methods: Changes in cellular metabolism in response to radiation are tracked by fluorescence lifetime of NADH. Expression of HIF-1α was measured by immunofluorescence for both cell lines with and without irradiation. Radiation response is also monitored with additional treatment of a HIF-1α inhibitor (chrysin) as well as a radical scavenger (glutathione). Changes in oxygen consumption and respiratory capacity are also monitored using the Seahorse XF analyzer. Results: An increase in HIF-1α was found to be in response to radiation for the cancer cell line, but not the normal cell line. Radiation was found to shift metabolism toward glycolytic pathways in cancer cells as measured by oxygen consumption and respiratory capacity. Radiation response was found to be muted by addition of glutathione to cell media. HIF-1α inhibition similarly muted radiation response in cancer. Conclusion: The HIF-1 protein complex is a key regulator cellular metabolism through the regulation of glycolysis and glucose transport enzymes. Moreover, HIF-1 has shown radio-protective effects in tumor vascular endothelia, and has been implicated in metastatic aggression. Monitoring interplay between metabolism and the HIF-1 protein complex can give a more fundamental understanding of radiotherapy response.

  19. 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.

  20. Combined low initial DNA damage and high radiation-induced apoptosis confers clinical resistance to long-term toxicity in breast cancer patients treated with high-dose radiotherapy

    Directory of Open Access Journals (Sweden)

    Bordón Elisa

    2011-06-01

    Full Text Available Abstract Background Either higher levels of initial DNA damage or lower levels of radiation-induced apoptosis in peripheral blood lymphocytes have been associated to increased risk for develop late radiation-induced toxicity. It has been recently published that these two predictive tests are inversely related. The aim of the present study was to investigate the combined role of both tests in relation to clinical radiation-induced toxicity in a set of breast cancer patients treated with high dose hyperfractionated radical radiotherapy. Methods Peripheral blood lymphocytes were taken from 26 consecutive patients with locally advanced breast carcinoma treated with high-dose hyperfractioned radical radiotherapy. Acute and late cutaneous and subcutaneous toxicity was evaluated using the Radiation Therapy Oncology Group morbidity scoring schema. The mean follow-up of survivors (n = 13 was 197.23 months. Radiosensitivity of lymphocytes was quantified as the initial number of DNA double-strand breaks induced per Gy and per DNA unit (200 Mbp. Radiation-induced apoptosis (RIA at 1, 2 and 8 Gy was measured by flow cytometry using annexin V/propidium iodide. Results Mean DSB/Gy/DNA unit obtained was 1.70 ± 0.83 (range 0.63-4.08; median, 1.46. Radiation-induced apoptosis increased with radiation dose (median 12.36, 17.79 and 24.83 for 1, 2, and 8 Gy respectively. We observed that those "expected resistant patients" (DSB values lower than 1.78 DSB/Gy per 200 Mbp and RIA values over 9.58, 14.40 or 24.83 for 1, 2 and 8 Gy respectively were at low risk of suffer severe subcutaneous late toxicity (HR 0.223, 95%CI 0.073-0.678, P = 0.008; HR 0.206, 95%CI 0.063-0.677, P = 0.009; HR 0.239, 95%CI 0.062-0.929, P = 0.039, for RIA at 1, 2 and 8 Gy respectively in multivariate analysis. Conclusions A radiation-resistant profile is proposed, where those patients who presented lower levels of initial DNA damage and higher levels of radiation induced apoptosis were at low

  1. Growth hormone used to control intractable bleeding caused by radiation-induced gastritis.

    Science.gov (United States)

    Zhang, Liang; Xia, Wen-Jie; Zhang, Zheng-Sen; Lu, Xin-Liang

    2015-08-21

    Intractable bleeding caused by radiation-induced gastritis is rare. We describe a 69-year-old man with intractable hemorrhagic gastritis induced by postoperative radiotherapy for the treatment of esophageal carcinoma. Although anti-secretory therapy with or without octreotide was initiated for hemostasis over three months, melena still occurred off and on, and the patient required blood transfusions to maintain stable hemoglobin. Finally growth hormone was used in the treatment of hemorrhage for two weeks, and hemostasis was successfully achieved. This is the first report that growth hormone has been used to control intractable bleeding caused by radiation-induced gastritis.

  2. Protection of myocytes against free radical-induced damage by accelerated turnover of the glutathione redox cycle

    NARCIS (Netherlands)

    Le, C. T.; Hollaar, L.; van der Valk, E. J.; Franken, N. A.; van Ravels, F. J.; Wondergem, J.; van der Laarse, A.

    1995-01-01

    The primary defence mechanism of myocytes against peroxides and peroxide-derived peroxyl and alkoxyl radicals is the glutathione redox cycle. The purpose of the present study was to increase the turnover rate of this cycle by stimulating the glutathione peroxidase catalysed reaction (2GSH-->GSSG),

  3. Light-induced formation of hydroxyl radicals in fog waters determined by an authentic fog constituent, hydroxymethanesulfonate.

    Science.gov (United States)

    Zuo, Yuegang

    2003-04-01

    The determination of the photo-production rate of hydroxyl radical (OH) in atmospheric liquids is of fundamental importance to an understanding of atmospheric aquatic chemistry. Recently, several studies have been performed to examine the photo-chemical formation rate of OH in cloud and fog waters using a free radical quenching technique with addition of a relatively large concentration of organic compounds as an OH scavenger. The addition of free-radical scavenger chemicals may significantly alter the nature of the sample water and its OH production rate. In this paper, an authentic constituent, hydroxymethanesulfonate, is proposed as a free radical probe for the measurement of photo-chemical generation rate of OH in fog water. At 313 nm, an apparent quantum yield for the production of OH in a fog water was found to be 0.012+/-0.001, indicating that aqueous-phase photo-chemical processes could represent a significant and may be a dominant source of OH in atmospheric liquids.

  4. Manganese-induced hydroxyl radical formation in rat striatum is not attenuated by dopamine depletion or iron chelation in vivo

    NARCIS (Netherlands)

    W.N. Sloot (W.); J. Korf (Jakob); J.F. Koster (Johan); L.E.A. de Wit (Elly); J.-B.P. Gramsbergen (J. B P)

    1996-01-01

    textabstractThe present studies were aimed at investigating the possible roles of dopamine (DA) and iron in production of hydroxyl radicals (.OH) in rat striatum after Mn2+ intoxication. For this purpose, DA depletions were assessed concomitant with in vivo 2,3- and 2,5-dihydroxybenzoic acid (DHBA)

  5. Manganese-induced hydroxyl radical formation in rat striatum is not attenuated by dopamine depletion or iron chelation in vivo

    NARCIS (Netherlands)

    Sloot, WN; Korf, J; Koster, JF; DeWit, LEA; Gramsbergen, JBP

    The present studies were aimed at investigating the possible roles of dopamine (DA) and iron in production of hydroxyl radicals ((OH)-O-.) in rat striatum after Mn2+ intoxication. For this purpose, DA depletions were assessed concomitant with in vivo 2,3- and 2,5-dihydroxybenzoic acid (DHBA)

  6. Superior vena cava obstruction caused by radiation induced venous fibrosis

    NARCIS (Netherlands)

    Van Putten, JWG; Schlosser, NJJ; Vujaskovic, Z; Van der Leest, AHD; Groen, HJM

    Superior vena cava syndrome is most often caused by lung carcinoma. Two cases are described in whom venous obstruction in the superior mediastinum was caused by local vascular fibrosis due to radiotherapy five and seven years earlier. The development of radiation injury to greater vessels is

  7. Wheat Germ Oil Attenuates Gamma Radiation-Induced Skeletal ...

    African Journals Online (AJOL)

    Muscular strength is important in sport as well as in daily activities. Exposure to ionizing radiation is thought to increase oxidative stress and damage muscle tissue. Wheat germ oil is a natural unrefined vegetable oil. It is an excellent source of vitamin E, octacosanol, linoleic and linolenic essential fatty acids, which may be ...

  8. Modeling of chronic radiation-induced cystitis in mice

    Directory of Open Access Journals (Sweden)

    Bernadette M.M. Zwaans, PhD

    2016-10-01

    Conclusions: We developed an RC model that mimics the human pathology and functional changes. Furthermore, radiation exposure attenuates the urothelial integrity long-term, allowing for potential continuous irritability of the bladder wall from exposure to urine. Future studies will focus on the underlying molecular changes associated with this condition and investigate novel treatment strategies.

  9. Ion induced radiation damage on the molecular level

    NARCIS (Netherlands)

    Alvarado Chacon, Fresia

    2007-01-01

    Throughout our lives we are exposed to ionizing radiation from cosmic and environmental sources or from medical diagnostics and treatments. In conventional therapy of malignant tumors, photons or electrons are used. Nowadays we witness the introduction of proton and heavy ion