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  1. 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.

  2. 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

  3. Black Hoof Medicinal Mushroom Phellinus linteus (Agaricomycetes) Extracts Protect Against Radiation-Induced Hematopoietic Abnormality in Mice.

    Science.gov (United States)

    Huang, Shu-Ming; Chen, Jen-Yin; Chen, Chin-Chu; Su, Chih-Chung; Hu, Miao-Lin

    2016-01-01

    We investigated the effects of Phellinus linteus extracts (PLEs) against radiation damage in mice. First, BALB/c mice were irradiated once with γ-rays at 4, 5, 6, or 8 Gy and allowed to recover for 20 days. Results reveal that 8-Gy radiation caused death in 100% of mice on day 13, and 6-Gy radiation caused death in 86.7% of mice (13/15) at the end of the experiment, whereas 4- and 5-Gy radiation did not result in any death. We then used 5-Gy γ-ray radiation to examine the protective effects of PLEs. Mice were orally administered a PLE (500, 1000, and 1500 mg/kg) daily for 2 weeks before radiation and for 6 weeks after radiation. γ-Ray radiation significantly decreased body weight starting from week 2 after radiation. Supplementation with a median and high dose of PLE significantly restored body weights starting at weeks 5 and 3, respectively. The radiation-protective agent WR2721 (200 mg/kg intraperitoneally) restored body weights starting at week 4. White blood cells, platelets, red blood cells, and hemoglobin were significantly decreased by radiation, and PLEs (primarily at high doses) and WR2721 significantly prevented hematologic abnormality. These results suggest that PLE has potential as a radioprotective agent. PMID:27649604

  4. Radiation-induced chromosomal instability

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    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.)

  5. Radiation-induced pneumothorax

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

    1983-01-01

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

  6. Radiation-induced pneumothorax

    International Nuclear Information System (INIS)

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

  7. Radiation Induced Fermion Resonance

    OpenAIRE

    Esposito, S.; M. W. Evans; Recami, E.

    1998-01-01

    The Dirac equation is solved for two novel terms which describe the interaction energy between the half integral spin of a fermion and the classical, circularly polarized, electromagnetic field. A simple experiment is suggested to test the new terms and the existence of radiation induced fermion resonance.

  8. Radiation induced oral mucositis

    OpenAIRE

    P S Satheesh Kumar; Anita Balan; Arun Sankar; Tinky Bose

    2009-01-01

    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 concer...

  9. Radiation induced pesticidal microbes

    International Nuclear Information System (INIS)

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

  10. [Radiation-induced cancers].

    Science.gov (United States)

    Dutrillaux, B

    1998-01-01

    The induction of malignant diseases is one of the most concerning late effects of ionising radiation. A large amount of information has been collected form atomic bomb survivors, patients after therapeutic irradiation, occupational follow-up and accidentally exposed populations. Major uncertainties persist in the (very) low dose range i.e., population and workers radioprotection. A review of the biological mechanisms leading to cancer strongly suggests that the vast majority of radiation-induced malignancies arise as a consequence of recessive mutations of tumour-suppressor genes. These mutations can be unveiled by ageing, this process being possibly furthered by constitutional or acquired genomic instability. The individual risk is likely to be very low, probably because of the usual dose level. However, the magnitude of medical exposure and the reliance of our societies on nuclear industry are so high that irreproachable decision-making processes and standards for practice are inescapable. PMID:9868399

  11. 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.

  12. 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

  13. Two pediatric cases of high dose radiation-induced meningiomas

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    Nagai, Miho [National Yokosuka Hospital, Kanagawa (Japan); Nagashima, Goro; Fujimoto, Tsukasa; Aoyagi, Masaru; Takasato, Yoshio

    2001-10-01

    There have been many reports of low dose radiation-induced meningiomas, and the number of reports of high dose radiation-induced meningiomas has been increasing recently. In this report, we present two cases of pediatric radiation-induced meningiomas, one 14 years after 36 Gy of radiation therapy for medulloblastoma and the other 8 years after 20 Gy of local radiation therapy for germinoma. Both patients underwent surgical removal of the meningiomas. The case of medulloblastoma was later revealed to be basal cell phacomatosis syndrome. Basal cell phacomatosis syndrome is a disease that occurs as a result of abnormality of chromosome 9. We speculate that the occurrence of radiation-induced meningioma may have been related to the basic genetic vulnerability of the patients. (author)

  14. Radiation induced nano structures

    International Nuclear Information System (INIS)

    Full text: Nanometer-size silicon clusters have been attracting much attention due to their technological importance, in particular, as promising building blocks for nano electronic and nano photonic systems. Particularly, silicon wires are of great of interest since they have potential for use in one-dimensional quantum wire high-speed field effect transistors and light-emitting devices with extremely low power consumption. Carbon and metal nano structures are studied very intensely due to wide possible applications. Radiation material sciences have been dealing with sub-micron objects for a long time. Under interaction of high energy particles and ionizing radiation with solids by elastic and inelastic mechanisms, at first point defects are created, then they form clusters, column defects, disordered regions (amorphous colloids) and finally precipitates of another crystal phase in the matrix. Such irradiation induced evolution of structure defects and phase transformations was observed by X-diffraction techniques in dielectric crystals of quartz and corundum, which exist in and crystal modifications. If there is no polymorphism, like in alkali halide crystals, then due to radiolysis halogen atoms are evaporated from the surface that results in non-stoichiometry or accumulated in the pores formed by metal vacancies in the sub-surface layer. Nano-pores are created by intensive high energy particles irradiation at first chaotically and then they are ordered and in part filled by inert gas. It is well-known mechanism of radiation induced swelling and embrittlement of metals and alloys, which is undesirable for construction materials for nuclear reactors. Possible solution of this problem may come from nano-structured materials, where there is neither swelling nor embrittlement at gas absorption due to very low density of the structure, while strength keeps high. This review considers experimental observations of radiation induced nano-inclusions in insulating

  15. Radiation induced diarrhoea - literature review

    International Nuclear Information System (INIS)

    Radiation-induced diarrhoea is an acute side effect of radiotherapy treatment to the pelvic area, experienced by nearly all patients. This paper will explore the patho-physiological rationale of diarrhoea, the causes of radiation-induced diarrhoea, the factors that influence the severity and occurrence, and the treatment of diarrhoea in relation to the radiotherapy setting, by analysing the current literature and will conclude by outlining future directions in this field. Copyright (2004) Australian Institute of Radiography

  16. Radiation-induced intestinal inflammation

    Institute of Scientific and Technical Information of China (English)

    Meritxell Mollà; Julián Panés

    2007-01-01

    Radiation induces an important inflammatory response in the irradiated organs, characterized by leukocyte infiltration and vascular changes that are the main limiting factor in the application of this therapeutic modality for the treatment of cancer. Recently, a considerable investigative effort has been directed at determining the molecular mechanisms by which radiation induces leukocyte recruitment, in order to create strategies to prevent intestinal inflammatory damage. In these review, we consider current available evidence on the factors governing the process of leukocyte recruitment in irradiated organs, mainly derived from experimental studies, with special attention to adhesion molecules, and their value as therapeutic targets.

  17. 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.

  18. 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.

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

    International Nuclear Information System (INIS)

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

  20. Study of microflora status of radiation-induced peripheral blood T cell and its subgroup changes

    International Nuclear Information System (INIS)

    Objective: To observe the differences of the radiation-induced peripheral blood T cell and its subgroup changes between SPF and CV rats after nasopharyngeal radiation with gradient doses and explore the microflora factors in the pathogenesis of abnormal radiation-induced immunity status. Methods: 8 from each SPF and CV rats were chosen for oropharyngeal bacteria cultivation and determination and the spleen organ coefficients. The rest were irradiated with 6MX linear accelerator in the nasopharyngeal fields at dose of 0, 10, 20, 30 Gy, 5 in each group. 24 ∼ 36 h later, blood T lymphocytes and their subgroups were detected by FCM. Results: The bacteria of CV rats were pathogen mostly and the one from SPF rats was Proteus mirabilis uniquely. Spleen organ coefficients between two groups showed no statistical difference. CD+3, CD+4 lymphocytes and the ratio of CD+4/ CD+8 of CV rats decreased dramatically after radiation is in close relation with radiation doses while The CD+8 lymphocyte increased a bit. The CD+3, CD+4, CD+8 lymphocytes and the ratio of CD+4/ CD+8 of SPF rats remained in a stable level. Conclusions: There exists the difference of radiation-induced injuries of immune system in relation with different microflora status. Micro-flora plays an important role in the radiation-induced immune system abnormity. (authors)

  1. Radiatively induced Quark and Lepton Mass Model

    CERN Document Server

    Nomura, Takaaki

    2016-01-01

    We propose a radiatively induced quark and lepton mass model in the first and second generation with extra $U(1)$ gauge symmetry and vector-like fermions. Then we analyze the allowed regions which simultaneously satisfy the FCNCs for the quark sector, LFVs including $\\mu-e$ conversion, the quark mass and mixing, and the lepton mass and mixing. Also we estimate the typical value for the $(g-2)_\\mu$ in our model.

  2. Radiatively induced quark and lepton mass model

    Science.gov (United States)

    Nomura, Takaaki; Okada, Hiroshi

    2016-10-01

    We propose a radiatively induced quark and lepton mass model in the first and second generation with extra U (1) gauge symmetry and vector-like fermions. Then we analyze the allowed regions which simultaneously satisfy the FCNCs for the quark sector, LFVs including μ- e conversion, the quark mass and mixing, and the lepton mass and mixing. Also we estimate the typical value for the (g - 2) μ in our model.

  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

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    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. Radiation-Induced Breast Cancer Incidence and Mortality from Digital Mammography Screening: A Modeling Study

    Science.gov (United States)

    Miglioretti, Diana L.; Lange, Jane; van den Broek, Jeroen J.; Lee, Christoph I.; van Ravesteyn, Nicolien T.; Ritley, Dominique; Kerlikowske, Karla; Fenton, Joshua J.; Melnikow, Joy; de Koning, Harry J.; Hubbard, Rebecca A.

    2016-01-01

    Background Estimates of radiation-induced breast cancer risk from mammography screening have not previously considered dose exposure variation or diagnostic work-up after abnormal screening. Objective To estimate distributions of radiation-induced breast cancer incidence and mortality from digital mammography screening, considering exposure from screening and diagnostic mammography and dose variation across women. Design Two simulation-modeling approaches using common data on screening mammography from the Breast Cancer Surveillance Consortium and radiation dose from mammography from the Digital Mammographic Imaging Screening Trial. Setting U.S. population. Patients Women aged 40–74 years. Interventions Annual or biennial digital mammography screening from age 40, 45, or 50 until 74. Measurements Lifetime breast cancer deaths averted (benefits) and radiation-induced breast cancer incidence and mortality per 100,000 women screened (harms). Results On average, annual screening of 100,000 women aged 40 to 74 years was projected to induce 125 breast cancers (95% confidence interval [CI]=88–178) leading to 16 deaths (95% CI=11–23) relative to 968 breast cancer deaths averted by early detection from screening. Women exposed at the 95th percentile were projected to develop 246 radiation-induced breast cancers leading to 32 deaths per 100,000 women. Women with large breasts requiring extra views for complete breast examination (8% of population) were projected to have higher radiation-induced breast cancer incidence and mortality (266 cancers, 35 deaths per 100,000 women), compared to women with small or average breasts (113 cancers, 15 deaths per 100,000 women). Biennial screening starting at age 50 reduced risk of radiation-induced cancers 5-fold. Limitations We were unable to estimate years of life lost from radiation-induced breast cancer. Conclusions Radiation-induced breast cancer incidence and mortality from digital mammography screening are impacted by dose

  6. Radiation-induced brachial plexopathy: MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wouter van Es, H. [Department of Radiology, University Hospital Utrecht, Heidelberglaan 100, 3584 CX Utrecht (Netherlands); Engelen, A.M. [Department of Radiation Therapy, University Hospital Utrecht, Utrecht (Netherlands); Witkamp, T.D. [Department of Radiology, University Hospital Utrecht, Heidelberglaan 100, 3584 CX Utrecht (Netherlands); Ramos, L.M.P. [Department of Radiology, University Hospital Utrecht, Heidelberglaan 100, 3584 CX Utrecht (Netherlands); Feldberg, M.A.M. [Department of Radiology, University Hospital Utrecht, Heidelberglaan 100, 3584 CX Utrecht (Netherlands)

    1997-05-01

    Objective. To describe the MR imaging appearance of radiation-induced brachial plexopathy. Design. MR imaging was performed in two patients with the clinical diagnosis of radiation-induced brachial plexopathy and in one with surgically proven radiation fibrosis of the brachial plexus. Patients. Three patients who had had radiation therapy to the axilla and supraclavicular region (two with breast carcinoma and one with Hodgkin`s lymphoma) presented with symptoms in the arm and hand. To exclude metastases or tumor recurrence MR imaging was performed. Results and conclusion. In one patient, fibrosis showing low signal intensity was found, while in two patients high signal intensity fibrosis surrounding the brachial plexus was found on the T2-weighted images. In one case gadolinium enhancement of the fibrosis was seen 21 years after radiation therapy. It is concluded that radiation-induced brachial plexopathy can have different MR imaging appearances. We found that radiation fibrosis can have both low or high signal intensities on T2-weighted images, and that fibrosis can enhance even 21 years after radiation therapy. (orig.). With 3 figs.

  7. Radiation induced glioblastoma. A case report

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    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)

  8. A case of radiation-induced glioma

    International Nuclear Information System (INIS)

    A case of malignant cerebellar glioma developing 25 years after radiotherapy for pineal tumor is described. The patient is a 40-year-old male, who was admitted to our department with complaints of dizziness and gait disturbance. neurological examinations revealed symptoms involving the left cerebellar hemisphere and cerebellar vermis. CT scan and MRI demonstrated a circularly enhanced tumor which was located in the left cerebellar hemisphere extending to the vermis. The tumor was diagnosed as malignant glioma. In view of the former radiotherapy, this glioma was suspected to have been induced by radiation. The situation conformed to Walker's criteria for radiation-induced tumor. With the patient under general anesthesia, the tumor was subtotally removed by means of suboccipitel craniectomy. Histopathologically, the tumor was diagnosed as astrocytoma, grade 3. Most radiation-induced gliomas are malignant. There seems to be no significant correlation between the radiation dose; the latent period widely varies, ranging from several years to more than 20 years. Even if the radiation dose is small, there still exists the risk that radiation might induce a tumor. It was concluded that the possibility of radiation-induced tumor should be kept in mind whenever radiation therapy is carried out for brain tumors. (author)

  9. Radiation-induced sensitisation of stainless steels

    International Nuclear Information System (INIS)

    The book contains the proceedings of a symposium on radiation-induced sensitization of stainless steels, which took place at Berkeley, United Kingdom, 1986. The purpose of the symposium was to examine the mechanism leading to inter-granular corrosion of 20%Cr/25% Ni/Nb stainless steel cladding of AGR fuel following irradiation. Nine papers are presented, of which three are theoretical, two papers are based upon corrosion studies of 20%Cr/25%Ni/Nb steel, and the remaining are concerned with compositional redistribution and its measurement. (U.K.)

  10. 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.

  11. Complicated biallelic inactivation of Pten in radiation-induced mouse thymic lymphomas

    International Nuclear Information System (INIS)

    Inactivation of the phosphatase and tensin homolog gene (Pten) occurs via multiple tissue-dependent mechanisms including epigenetic silencing, point mutations, insertions, and deletions. Although frequent loss of heterozygosity around the Pten locus and plausible involvement of epigenetic silencing have been reported in radiation-induced thymic lymphomas, the proportion of lymphomas with inactivated Pten and the spectrum of causal aberrations have not been extensively characterized. Here, we assessed the mode of Pten inactivation by comprehensive analysis of the expression and alteration of Pten in 23 radiation-induced thymic lymphomas developed in B6C3F1 mice. We found no evidence for methylation-associated silencing of Pten; rather, complex structural abnormalities comprised of missense and nonsense mutations, 1- and 3-bp insertions, and focal deletions were identified in 8 of 23 lymphomas (35%). Sequencing of deletion breakpoints suggested that aberrant V(D)J recombination and microhomology-mediated rearrangement were responsible for the focal deletions. Seven of the 8 lymphomas had biallelic alterations, and 4 of them did not express Pten protein. These Pten aberrations coincided with downstream Akt phosphorylation. In conclusion, we demonstrate that Pten inactivation is frequently biallelic and is caused by a variety of structural abnormalities (rather than by epigenetic silencing) and is involved in radiation-induced lymphomagenesis.

  12. Radiation-induced doping of conducting polymers

    International Nuclear Information System (INIS)

    Conducting polymers have the potential form many applications in electronics. The various patterns of doped regions of conducting polymers should be generated for the applications. Doping of conducting polymers is achieved by contact of the polymer with dopant or electrochemically. By these methods, doping occurs in the entire area exposed to the dopant. It is necessary to combine these doping techniques with lithography for achieving the patterned doping. Radiation-induced doping effects of conducting polymers have been reported. The doping is performed by irradiation of polymers in an atmosphere of gases, which do not react without irradiation, such as CH3Br, SF6, and N2O. If only the irradiated area was doped, patterned doping could be achieved without using lithography technique. We have elucidated the mechanism of the radiation-induced doping. The electrical conductivity was increased by irradiation the gas near the polymer film without irradiating the film itself. This result indicates that dopants were generated upon irradiation in the gas phase and the dopants react with the polymer. Hence, the pattern of doping is blurred by this method. We then developed another method of radiation-induced doping. Solid dopant precursor was coated on the polymer, and irradiation was performed. Figure 1 shows the results for poly(3-octylhitophene)(P3OT) by this method. A film of poly(3-octylthiophene) was prepared by spin coating from a solution of tetrahydrofuran on a quartz plate. The thickness of the film was approximately 100 nm. The polymer film was dried overnight at 80 degree C in a vacuum, and Au electrodes were evaporated on the films for electrical conductivity measurements. Saturated solution of 1,2,5,6,9,10-hexabromocyclododecane (HBCD) in 1-bromopropane was dropped on the film and dried at room temperature in a vacuum. The film was put in a vacuum chamber, which has a 0.2-mm-thick Be window. X rays entered through the Be window, and the films were irradiated

  13. Triptolide Mitigates Radiation-Induced Pulmonary Fibrosis.

    Science.gov (United States)

    Yang, Shanmin; Zhang, Mei; Chen, Chun; Cao, Yongbin; Tian, Yeping; Guo, Yangsong; Zhang, Bingrong; Wang, Xiaohui; Yin, Liangjie; Zhang, Zhenhuan; O'Dell, Walter; Okunieff, Paul; Zhang, Lurong

    2015-11-01

    Triptolide (TPL) may mitigate radiation-induced late pulmonary side effects through its inhibition of global pro-inflammatory cytokines. In this study, we evaluated the effect of TPL in C57BL/6 mice, the animals were exposed to radiation with vehicle (15 Gy), radiation with TPL (0.25 mg/kg i.v., twice weekly for 1, 2 and 3 months), radiation and celecoxib (CLX) (30 mg/kg) and sham irradiation. Cultured supernatant of irradiated RAW 264.7 and MLE-15 cells and lung lysate in different groups were enzyme-linked immunosorbent assays at 33 h. Respiratory rate, pulmonary compliance and pulmonary density were measured at 5 months in all groups. The groups exposed to radiation with vehicle and radiation with TPL exhibited significant differences in respiratory rate and pulmonary compliance (480 ± 75/min vs. 378 ± 76/min; 0.6 ± 0.1 ml/cm H2O/p kg vs. 0.9 ± 0.2 ml/cm H2O/p kg). Seventeen cytokines were significantly reduced in the lung lysate of the radiation exposure with TPL group at 5 months compared to that of the radiation with vehicle group, including profibrotic cytokines implicated in pulmonary fibrosis, such as IL-1β, TGF- β1 and IL-13. The radiation exposure with TPL mice exhibited a 41% reduction of pulmonary density and a 25% reduction of hydroxyproline in the lung, compared to that of radiation with vehicle mice. The trichrome-stained area of fibrotic foci and pathological scaling in sections of the mice treated with radiation and TPL mice were significantly less than those of the radiation with vehicle-treated group. In addition, the radiation with TPL-treated mice exhibited a trend of improved survival rate compared to that of the radiation with vehicle-treated mice at 5 months (83% vs. 53%). Three radiation-induced profibrotic cytokines in the radiation with vehicle-treated group were significantly reduced by TPL treatment, and this partly contributed to the trend of improved survival rate and pulmonary density and function and the decreased severity of

  14. Radiation-induced valvular heart disease.

    Science.gov (United States)

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

    2016-02-15

    Radiation to the mediastinum is a key component of treatment with curative intent for a range of cancers including Hodgkin's lymphoma and breast cancer. Exposure to radiation is associated with a risk of radiation-induced heart valve damage characterised by valve fibrosis and calcification. There is a latent interval of 10-20 years between radiation exposure and development of clinically significant heart valve disease. Risk is related to radiation dose received, interval from exposure and use of concomitant chemotherapy. Long-term outlook and the risk of valve surgery are related to the effects of radiation on mediastinal structures including pulmonary fibrosis and pericardial constriction. Dose prediction models to predict the risk of heart valve disease in the future and newer radiation techniques to reduce the radiation dose to the heart are being developed. Surveillance strategies for this cohort of cancer survivors at risk of developing significant heart valve complications are required.

  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. Radiation-Induced Esophagitis Exacerbated by Everolimus

    Directory of Open Access Journals (Sweden)

    Yuji Miura

    2013-06-01

    Full Text Available Background: Everolimus, a potent mammalian target of rapamycin (mTOR inhibitor, has shown anticancer activity against various types of cancer, including renal cell carcinoma (RCC; however, little information is available on the efficacy and safety of the combination of everolimus and radiotherapy. We report a case of radiation-induced esophagitis that might have been exacerbated by the sequential administration of everolimus. Case Presentation: A 63-year-old Japanese man with RCC complained of back pain, and magnetic resonance imaging revealed vertebral metastases. He received radiotherapy (30 Gy/10 fractions to the T6-10 vertebrae. Everolimus was administered immediately after the completion of radiotherapy. One week later, he complained of dysphagia, nausea and vomiting. An endoscopic examination of the esophagus showed erosive esophagitis in the middle to lower portions of his thoracic esophagus, corresponding to the irradiation field. Conclusion: Clinicians should be aware that everolimus might lead to the unexpected exacerbation of radiation toxicities.

  17. Radiation-induced grafting onto wool

    International Nuclear Information System (INIS)

    Radiation-induced grafting tests were done on single wool fibres. Different vinyl monomers were used for this purpose and they were grafted in twenty different solvents which were selected for their swelling effiency and solvent parameters. The tests were done once with and once without the addition of water. The presence of water causes the polymer uptake to increase considerably. Formic acid/methanol and methanol were found to be the most suitable solvent systems, as they have the highest hydrogen-bond interaction effiency. The moisture uptake of wool depends on the hydrophily and hydrophoby of the grafted polymers. The single-fibre tests serve as a basis for analogous grafting tests on wool fabrics. The permanent- press was improved by graftng with hydrophoric polymers and polymers with a high glass-transition temperature

  18. Gamma-radiation-induced grafting onto wool

    International Nuclear Information System (INIS)

    Radiation-induced grafting studies have been carried out on loose wool fibres. Different vinyl monomers were used and they were grafted in different solvents which were selected on the basis of their swelling efficiency and solubility parameters. The treatments were performed once with and once without the addition of water. The presence of water caused the polymer uptake to increase considerably. Formic acid/methanol and methanol accelerate the grafting process best, since they have the highest hydrogen-bond interaction efficiency. The moisture uptake of grafted wool decreases. X-ray and differential scanning calorimetry tests show unambiguously that grafting occurs in different morphological areas, depending on the type of polymer. The single fibre studies served as basis for analogous tests on wool fabrics (Part II). (author)

  19. Radiation-induced electron migration along DNA

    International Nuclear Information System (INIS)

    Radiation-induced electron migration along DNA is a mechanism by which randomly produced stochastic energy deposition events can lead to nonrandom types of damage along DNA manifested distal to the sites of the initial energy deposition. Electron migration along DNA is significantly influenced by the DNA base sequence and DNA conformation. Migration along 7 base pairs in oligonucleotides containing guanine bases was observed for oligonucleotides irradiated in solution which compares to average migration distances of 6 to 10 bases for Escherichia coli DNA irradiated in solution and 5.5 base pairs for Escherichia coli DNA irradiated in cells. Evidence also suggests that electron migration can occur preferentially in the 5' to 3' direction along DNA. Our continued efforts will provide information regarding the contribution of electron transfer along DNA to formation of locally multiply damaged sites created in DNA by exposure to ionizing radiation

  20. Radiation-induced damage to DNA

    International Nuclear Information System (INIS)

    This short survey focuses on the main radiation-induced base lesions that have been identified within cellular DNA. For this purpose, sensitive assays that are aimed at measuring a few modifications per 107 normal bases were set-up. In that respect high performance liquid chromatography - tandem mass spectrometry (CLHP-MS/MS) was found to be able to single out the formation of 9 oxidized nucleosides and two modified nucleo-bases out of the 70 oxidative base lesions that have been identified in model systems. As a striking result, it was found that in the DNA of γ-irradiated human monocytes, the formamide-pyrimidine derivative of guanine is produced in a higher yield than the ubiquitous 8-oxo-7,8-dihydro-guanine damage, both arising from the same radical precursor. However, relatively high doses of ionizing radiation (> 20 Gy) have to be applied in order to detect an increase in the level of the damage. This is due to the low efficiency for both low and high LET radiations to generate oxidative damage to DNA on one hand and the occurrence of artifactual oxidation of the overwhelming normal bases during DNA extraction on the other hand. Interestingly, a modified comet assays that involves the combined use of the alkaline single gel electrophoretic technique and DNA repair N-glycosylases has allowed the detection of three main types of radiation-induced damage within the dose range 0.3 Gy -10 Gy. It appears that the total of frank DNA strand breaks and alkali-labile sites is similar to the sum of oxidized pyrimidine bases and modified purine bases that are recognized by the endonuclease Ill protein and the formamide-pyrimidine DNA N-glycosylase respectively. (author)

  1. Radiation induced thyroid neoplasms 1920 to 1987: A vanishing problem

    Energy Technology Data Exchange (ETDEWEB)

    Mehta, M.P.; Goetowski, P.G.; Kinsella, T.J.

    1989-06-01

    Radiation for benign diseases has been implicated as an etiologic factor in thyroid cancer. From 1930-60, over 2 million children may have been exposed to therapeutic radiation and it is estimated that up to 7% may develop thyroid cancer after a 5-40 year latency. Thyroid stimulating hormone, secondary to radioinduced hypothyroidism, has been implicated as causative in animals. Such data has led to expensive screening programs in high risk patients. Because of a decline in irradiation for benign diseases in children over the last 2 decades, we questioned whether the incidence of radiation induced thyroid neoplasms (RITN) was also decreasing. Twenty-six of 227 patients (11%) with thyroid malignancies seen at our institution from 1974-87 had a history of previous head and neck irradiation. These included 13 papillary, 3 follicular, and 7 mixed carcinomas as well as 2 lymphomas and 1 synovial cell sarcoma. None of these 26 patients had abnormal thyroid function tests at presentation. Mean latency from irradiation to the diagnosis of thyroid cancer was 25.4 years (6-55 year range). Compared to the reported increasing incidence of RITN from 1940-70, there appears to be a significant decrease since 1970. Based on our analysis, the use of expensive screening programs in high risk populations may no longer be warranted. Additionally, the routine use of thyroid replacement in previously irradiated chemically hypothyroid patients is not recommended.30 references.

  2. Radiation-induced apoptosis and developmental disturbance of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Inouye, Minoru [Nagoya Univ. (Japan). Research Inst. of Environmental Medicine

    1995-03-01

    The developing mammalian brain is highly susceptible to ionizing radiation. A significant increase in small head size and mental retardation has been noted in prenatally exposed survivors of the atomic bombing, with the highest risk in those exposed during 8-15 weeks after fertilization. This stage corresponds to day 13 of pregnancy for mice and day 15 for rats in terms of brain development. The initial damage produced by radiation at this stage is cell death in the ventricular zone (VZ) of the brain mantle, the radiosensitive germinal cell population. During histogenesis of the cerebellum the external granular layer (EGL) is also radiosensitive. Although extensive cell death results in microcephaly and histological abnormlity, both VZ and EGL have an ability to recover from a considerable cell loss and form the normal structure of the central nervous system. The number of cell deaths to induce tissue abnormalities in adult brain rises in the range of 15-25% of the germinal cell population; and the threshold doses are about 0.3 Gy for cerebral defects and 1 Gy for cerebellar anomalies in both mice and rats. A similar threshold level is suggested in human cases in induction of mental retardation. Radiation-induced cell death in the VZ and EGL has been revealed as apoptosis, by the nuclear and cytoplasmic condensation, transglutaminase activation, required macromolecular synthesis, and internucleosomal DNA cleavage. Apoptosis of the germinal cell is assumed to eliminate acquired genetic damage. Once an abnormality in DNA has been induced and fixed in a germinal cell, it would be greatly amplified during future proliferation. These cells would commit suicide when injured for replacement by healthy cells, rather than undertake DNA repair. In fact they show very slow repair of cellular damage. Thus the high sensitivity of undifferentiated neural cells to the lethal effect of radiation may constitute a biological defense mechanism. (author) 69 refs.

  3. Radiation-induced cancer in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, Shoji; Sekizuka, Eiichi [National Saitama Hospital, Wako (Japan); Yamashita, Hisao [Keio Cancer Center, Tokyo (Japan); Takami, Akira [Yamawaki Coll., Tokyo (Japan); Kubo, Atsushi [Keio Univ., Tokyo (Japan). School of Medicine

    2001-12-01

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

  4. Radiation induced mutations for breeding of sorghum

    International Nuclear Information System (INIS)

    Several sorghum cultivars of Mali were irradiated with different doses of gamma rays and compared with the Caudatum types. Radio-sensitivity studies suggested that the local types were less sensitive to radiation than the introduced types. Whereas the local varieties survived dose of 300 Gy, in Caudatum types, seed germination and growth were significantly reduced at 200 Gy. Several agronomically important mutants were obtained among the progeny of the local types. Some of the mutants were shorter and had improved panicle characteristics. Radiation-induced variation was observed in several characters such as plant height, resistance to lodging, plant architecture, drought tolerance, panicle length and compactness, seed size and color, seed quality (viterous or floury) and protein content, glume color and structure, flowering data (early and late maturity), and tillering capacity. One mutant was drought tolerant. Promising mutants were selected and are presently under evaluation in the National List Trials to confirm their potential and future release. Selected variants have been also crossed with local types to obtain promising material. (author). 8 refs, 2 tabs

  5. Ionizing radiation induces stemness in cancer cells.

    Directory of Open Access Journals (Sweden)

    Laura Ghisolfi

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

  6. Retroviruses in radiation-induced lymphomas

    International Nuclear Information System (INIS)

    The nucleotide sequence of RadLV/VL3(T+L+), the thymotropic and leukemogenic entity of the in-vitro propagated radiation leukemia virus complex (RadLV/VL3), is that of a recombinant retrovirus. The gag, pol and most of the env gene are very similar to the homologous regions of Akv MuLV. The 3' end of the env gene and the LTR appear to have derived from a xenotropic MuLV. However, the LTR has acquired a feature shared by other lymphomagenic MuLVs. This feature consists in sequence rearrangements resulting in the generation of presumed enhancer elements. RadLV/VL3(T+L+)-specific proviral sequences were found adjacent to the c-myc gene in several virus-induced thymic lymphomas of the rat, suggesting that the enhancer elements might play a role in lymphomagenesis. However, it was found that the presence of a provirus at a specific DNA site can lead to an in-vitro growth advantage and to clonal cell selection independently of a lymphomagenic process. The authors conclude from this observation that clonal appearance of an integrated provirus in cultured radiogenic lymphoma cells does not necessarily reflect a viral induction of radiation-induced leukemogenesis. (author)

  7. Simplified experimental technique to extract the acoustic radiation induced static strain in solids

    Science.gov (United States)

    Thimmavajjula Narasimha, Karthik; Kannan, Elankumaran; Balasubramaniam, Krishnan

    2007-09-01

    A simplified experimental technique to measure the acoustic radiation induced static strain during the longitudinal acoustic wave propagation in solids is proposed. Experiments have been carried out to extract the static displacement (dc) component without resorting to electronic filters, as in the case of previously reported experimental measurements. This prevents the influence of the filter time response characteristics on the measurement. The dependence of the static displacement amplitude on the square of the fundamental amplitude of the input wave, its being independent of the burst width of the tone burst, and its abnormal variation at low input amplitudes are reported.

  8. Hazard of the radiation induced thyroid cancer

    International Nuclear Information System (INIS)

    The level of thyroid cancer in Belarus before Chernobyl accident was low and made in different age and sex groups 0,03-2,5 (male) and 0,1-3,9 (female) per 100000 correspondingly. Different risk factors, which can influence the thyroid cancer development, are being taken into account. They are the factors of environment (strong external irradiation, long-time irradiation for medical purposes or in result of disaster), endo gen factors (hormonal, reproductive, genetic predisposition), some medicinal preparations and other. The protective effect of vegetable and fish consumption was found out. Among the factors of thyroid cancer development one of the most important is radiation. There is a point of view, which assumes that one of the reasons of thyroid cancer cases increase among the population of developed countries is increase of radiation induced thyroid cancer. The results of first research testify the influence of radiation factor on thyroid cancer development. During the period 1920 -1960 in the USA X-ray therapy was applied for the treatment of different good-quality diseases. Thyroid got in the zone of irradiation during the complex treatment with using of radiation. The results of the research of 1970 revealed that 70% of children with thyroid cancer were exposed to radiation in children's age. The subsequent researches of by-effects from the side of a thyroid at beam therapy of various diseases alongside with the results of the estimation of consequences of inhabitants of Hiroshima and Nagasaki irradiation owing to nuclear bombardment have shown the influence of irradiation of a thyroid on cancer development. High quantity of radio-epidemiological researches was directed to the studying of the consequences of thyroid external irradiation at young age. In all carried out researches the quantity of observed thyroid cancer cases among irradiated people has exceeded number of expected. The influence of thyroid internal irradiation by I-131 at young age was

  9. Delayed Radiation-Induced Vasculitic Leukoencephalopathy

    International Nuclear Information System (INIS)

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

  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. Rosiglitazone attenuates pulmonary fibrosis and radiation-induced intestinal damage

    International Nuclear Information System (INIS)

    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

  12. 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

  13. Clarithromycin Attenuates Radiation-Induced Lung Injury in Mice

    OpenAIRE

    Lee, Seung Jun; Yi, Chin-ok; Heo, Rok Won; Song, Dae Hyun; Cho, Yu Ji; Jeong, Yi Yeong; Kang, Ki Mun; Roh, Gu Seob; Lee, Jong Deog

    2015-01-01

    Radiation-induced lung injury (RILI) is a common and unavoidable complication of thoracic radiotherapy. The current study was conducted to evaluate the ability of clarithromycin (CLA) to prevent radiation-induced pneumonitis, oxidative stress, and lung fibrosis in an animal model. C57BL/6J mice were assigned to control, irradiation only, irradiation plus CLA, and CLA only groups. Test mice received single thoracic exposures to radiation and/or oral CLA (100 mg/kg/day). Histopathologic finding...

  14. Physical mechanisms of radiation induced creep in metals

    International Nuclear Information System (INIS)

    Analysis of available experimental data has been conducted. It enables to correlate reliably the character of evolution of dislocation structure of irradiated materials with different stages of radiation induced creep. This provides reliable basis for the general conclusions concerning the character of some parametric dependences of deformation rate of these materials. Analysis of different modern theoretical models enables to evaluate regions of their applicability and their relative significance for radiation induced creep description. 20 refs.; 2 figs.; 1 tab

  15. 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...... with variable risk of RIF (grouped into five classes from low to high risk) were irradiated with two different schemes: 1x3.5Gy with RNA isolated 2 and 24h after irradiation, and a fractionated scheme with 3x3.5Gy in intervals of 24h with RNA isolated 2h after the last dose. RNA was also isolated from non...... and the four patients with the lowest risk of RIF after the fractionated scheme. The genes were associated with known functions in processes like apoptosis, extracellular matrix remodelling/cell adhesion, proliferation and ROS scavenging. A minimum set of 18 genes were identified that could differentiate high...

  16. Clinical and dosimetric factors of radiation-induced esophageal injury: Radiation-induced esophageal toxicity

    Institute of Scientific and Technical Information of China (English)

    Wen-Bo Qiao; Yan-Hui Zhao; Yan-Bin Zhao; Rui-Zhi Wang

    2005-01-01

    AIM: To analyze the clinical and dosimetric predictive factors for radiation-induced esophageal injury in patients with non-small-cell lung cancer (NSCLC) during threedimensional conformal radiotherapy (3D-CRT). METHODS: We retrospectively analyzed 208 consecutive patients (146 men and 62 women) with NSCLC treated with 3D-CRT. The median age of the patients was 64 years (range 35-87 years). The clinical and treatment parameters including gender, age, performance status, sequential chemotherapy, concurrent chemotherapy, presence of carinal or subcarinal lymph nodes, pretreatment weight loss, mean dose to the entire esophagus, maximal point dose to the esophagus, and percentage of volume of esophagus receiving >55 Gy were studied. Clinical and dosimetric factors for radiation-induced acute and late grade 3-5 esophageal injury were analyzed according to Radiation Therapy Oncology Group (RTOG) criteria.RESULTS: Twenty-five (12%) of the two hundred and eight patients developed acute or late grade 3-5 esophageal injury. Among them, nine patients had both acute and late grade 3-5 esophageal injury, two died of late esophageal perforation. Concurrent chemotherapy and maximal point dose to the esophagus ≥60 Gy were significantly associated with the risk of grade 3-5 esophageal injury. Fifty-four (26%) of the two hundred and eight patients received concurrent chemotherapy. Among them, 25 (46%) developed grade 3-5 esophageal injury (P = 0.0001<0.01). However, nograde 3-5 esophageal injury occurred in patients who received a maximal point dose to the esophagus <60 Gy (P= 0.0001<0.01).CONCLUSION: Concurrent chemotherapy and the maximal esophageal point dose ≥60 Gy are significantly associated with the risk of grade 3-5 esophageal injury in patients with NSCLC treated with 3D-CRT.

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

    International Nuclear Information System (INIS)

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

  18. Radiation-Induced Cancer. Proceedings of a Symposium on Radiation-Induced Cancer

    International Nuclear Information System (INIS)

    The link between radiation and cancer was recognized soon after the discovery of X-rays and natural radioactivity. In the early years after the discovery of ionizing radiations some of the pioneering workers suffered severely from the damaging effects of radiation exposure. These incidents,- generally due to ignorance of the biological consequences of radiation exposure, were instrumental in starting investigations on the subject. Gradually precise information became available on the nature of radiation-induced damage and on the repair phenomena. This information has been advanced by recent progress in molecular biology, cellular biology, cytogenetics, biochemistry, virology, immunology and related disciplines. Contributions of these disciplines to radiation biology and cancer research has resulted in the use of radiation to solve various problems of human health including cancer. At the same time, with knowledge of the effects of radiations on cells and on various organisms including man, it has become possible to state the level of radiation dose that is not an apparent health hazard (i. e. the maximum permissible dose). This work has been vitally important in programs dealing with the occupational safety of personnel working with radiations. Although the present safety standards and devices are generally recognized as adequate, they must be re-evaluated from time to time in the light of the latest findings in radiobiology and other related disciplines. The Symposium on Radiation-Induced Cancer, organized by the International Atomic Energy Agency in collaboration with the World Health Organization, permitted discussion and evaluation of the present understanding of the nature of late biological effects of radiations including cancer, and development of protective as well as curative measures against cancer. Much attention was given to the comparative analysis of the effects of radiation, particularly at low dose levels, on man and experimental mammals. Emphasis

  19. Radiation-induced brain disorders in patients with pituitary tumours

    International Nuclear Information System (INIS)

    Radiation-induced brain disorders (RIBD) are uncommon and they are grave sequelae of conventional radiotherapy. In the present report, we describe the clinical spectrum of RIBD in 11 patients who received post-surgery conventional megavoltage irradiation for residual pituitary tumours. Of these 11 patients (nine men, two women), seven had been treated for non-functioning pituitary tumours and four for somatotropinomas. At the time of irradiation the age of these patients ranged from 30 to 59 years (mean, 39.4 ± 8.3; median, 36) with a follow-up period of 696 months (mean, 18.3 ± 26.4; median, 11). The dose of radiation ranged from 45 to 90 Gy (mean, 51.3 ± 13.4; median, 45), which was given in 1530 fractions (mean, 18.6 ± 5.0; median, 15) with 2.8 ± 0.3 Gy (median, 3) per fraction. The biological effective dose calculated for late complications in these patients ranged from 78.7 to 180 Gy (mean, 99.1 ± 27.5; median, 90). The lag time between tumour irradiation and the onset of symptoms ranged from 6 to 168 months (mean, 46.3 ± 57.0; median, 57). The clinical spectrum of RIBD included new-onset visual abnormalities in five, cerebral radionecrosis in the form of altered sensorium in four, generalized seizures in four, cognitive dysfunction in five, dementia in three and motor deficits in two patients. Magnetic resonance imaging (MRI)/CT of the brain was suggestive of radionecrosis in eight, cerebral oedema in three, cerebral atrophy in two and second neoplasia in one patient. Associated hormone deficiencies at presentation were hypogonadism in eight, hypoadrenalism in six, hypothyroidism in four and diabetes insipidus in one patient. Autopsy in two patients showed primitive neuroectodermal tumour (PNET) and brainstem radionecrosis in one, and a cystic lesion in the left frontal lobe following radionecrosis in the other. We conclude that RIBD have distinctive but varying clinical and radiological presentations. Diabetes insipidus and PNET as a second neoplastic

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-01-01

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

  1. Hedgehog signaling and radiation induced liver injury: a delicate balance.

    Science.gov (United States)

    Kabarriti, Rafi; Guha, Chandan

    2014-07-01

    Radiation-induced liver disease (RILD) is a major limitation of radiation therapy (RT) for the treatment of liver cancer. Emerging data indicate that hedgehog (Hh) signaling plays a central role in liver fibrosis and regeneration after liver injury. Here, we review the potential role of Hh signaling in RILD and propose the temporary use of Hh inhibition during liver RT to radiosensitize HCC tumor cells and inhibit their progression, while blocking the initiation of the radiation-induced fibrotic response in the surrounding normal liver. PMID:26202634

  2. Chemoprevention of Radiation Induced Rat Mammary Neoplasms

    Science.gov (United States)

    Huso, David L.

    1999-01-01

    microcancers, arresting preneoplastic lesions, or correcting abnormal environments which predispose to high risk of malignant transformation.

  3. Evening Primrose Oil Attenuates Certain Radiation Induced Functional and structural Disorders in Female Rats

    Directory of Open Access Journals (Sweden)

    Fatma, L.R. and Rezk R. G

    2004-09-01

    Full Text Available The aim of the present study was to evaluate the modulator role of evening primrose oil (EPO on the radiation induced changes in certain biochemical and histological abnormalities. Female rats were exposed to 5 Gy whole body -irradiation delivered as single dose. EPO was orally administrated to rats (9 ml/100g b.wt 7 days before irradiation exposure. Animals were sacrificed 1 day (oestrus stage, 6 days (one estrus cycle and 12 days (two estrus cycle after irradiation. The results obtained revealed that treatment with EPO diminished the increase in total cholesterol, urea and creatinine levels in plasma in comparison with the levels recorded in the plasma of irradiated rats. Significant amelioration of the radiation induced changes in RBC,s WBC,s count and the haemoglobin concentration, calcium level, FSH and LH hormones were also recorded in the plasma of EPO treated and irradiated rats. Histological observations of photomicrograph of kidney and ovary sections showed that irsaoiaun resulted in irradiation induced ruptured, dilated, haemorrhage glomerulei dissolution of the majority of primary follicles, and atrophy in ovary size. All these changes were obviously improved in animals supplied with EPO. It could be concluded that EPO could be useful adjunct for maintaining the integrity of biochemical functions and restoring the original histological architecture of kidney and ovary after irradiation.

  4. Induction of Excess Centrosomes in Neural Progenitor Cells during the Development of Radiation-Induced Microcephaly.

    Directory of Open Access Journals (Sweden)

    Mikio Shimada

    Full Text Available The embryonic brain is one of the tissues most vulnerable to ionizing radiation. In this study, we showed that ionizing radiation induces apoptosis in the neural progenitors of the mouse cerebral cortex, and that the surviving progenitor cells subsequently develop a considerable amount of supernumerary centrosomes. When mouse embryos at Day 13.5 were exposed to γ-rays, brains sizes were reduced markedly in a dose-dependent manner, and these size reductions persisted until birth. Immunostaining with caspase-3 antibodies showed that apoptosis occurred in 35% and 40% of neural progenitor cells at 4 h after exposure to 1 and 2 Gy, respectively, and this was accompanied by a disruption of the apical layer in which mitotic spindles were positioned in unirradiated mice. At 24 h after 1 Gy irradiation, the apoptotic cells were completely eliminated and proliferation was restored to a level similar to that of unirradiated cells, but numerous spindles were localized outside the apical layer. Similarly, abnormal cytokinesis, which included multipolar division and centrosome clustering, was observed in 19% and 24% of the surviving neural progenitor cells at 48 h after irradiation with 1 and 2 Gy, respectively. Because these cytokinesis aberrations derived from excess centrosomes result in growth delay and mitotic catastrophe-mediated cell elimination, our findings suggest that, in addition to apoptosis at an early stage of radiation exposure, radiation-induced centrosome overduplication could contribute to the depletion of neural progenitors and thereby lead to microcephaly.

  5. Radiographic and CT features of radiation-induced organizing pneumonia syndrome after breast-conserving therapy

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate radiographic and computed tomography features of radiation-induced organizing pneumonia syndrome after breast-conserving surgery. The appearances and distribution of lung parenchymal abnormalities were retrospectively analyzed on chest radiographs (n=12) and computed tomography scan images (n=10) of 12 women (range 37-78 years, mean 55.8 years) with radiation-induced organizing pneumonia syndrome after breast-conserving surgery. The principal radiographic feature was an airspace filling pattern in all patients that involved the middle and lower lung zones in 10 of the 12 patients. Multi-focal lesions manifesting airspace consolidation surrounded by ground-glass opacities were the predominant CT finding in all 10 of these patients. The main lesion was predominantly located in the lung periphery in nine patients and contiguously extended to the central portion of the lung in seven patients. Frequent ancillary findings were airway dilation within the consolidation and lobar volume loss in nine and eight patients, respectively. All had solitary (6/10) or multifocal (4/10) distant lung opacities, mostly consistent with the finding of ground-glass opacities (9/10). Migration of the lung disease was observed in ten patients on subsequent radiographs. The cardinal radiologic feature of this syndrome is airspace consolidation surrounded by ground-glass opacification with airway dilation and volume loss, involving primarily the irradiated, subpleural area, along with distant opacities. (author)

  6. Radiation-induced xerostomia: pathophysiology, clinical course and supportive treatment.

    Science.gov (United States)

    Guchelaar, H J; Vermes, A; Meerwaldt, J H

    1997-07-01

    Xerostomia, or oral dryness, is one of the most common complaints experienced by patients who have had radiotherapy of the oral cavity and neck region. The hallmarks of radiation-induced damage are acinar atrophy and chronic inflammation of the salivary glands. The early response, resulting in atrophy of the secretory cells without inflammation might be due to radiation-induced apoptosis. In contrast, the late response with inflammation could be a result of radiation-induced necrosis. The subjective complaint of a dry mouth appears to be poorly correlated with objective findings of salivary gland dysfunction. Xerostomia, with secondary symptoms of increased dental caries, difficulty in chewing, swallowing and speaking, and an increased incidence of oral candidiasis, can have a significant effect on the quality of life. At present there is no causal treatment for radiation-induced xerostomia. Temporary symptomatic relief can be offered by moistening agents and saliva substitutes, and is the only option for patients without residual salivary function. In patients with residual salivary function, oral administration of pilocarpine 5-10 mg three times a day is effective in increasing salivary flow and improving the symptoms of xerostomia, and this therapy should be considered as the treatment of choice. Effectiveness of sialogogue treatment requires residual salivary function, which emphasizes the potential benefit from sparing normal tissue during irradiation. The hypothesis concerning the existence of early apoptotic and late necrotic effects of irradiation on the salivary glands theoretically offers a way of achieving this goal.

  7. Acoustic radiation-induced static strains in solids

    Science.gov (United States)

    Cantrell, John H.; Yost, William T.; Li, Peter

    1987-01-01

    The controversy surrounding the magnitude of the radiation-induced static strain accompanying acoustic wave propagation in solids is resolved by a consideration of the associated Boussinesq radiation stress. Experimental verification of the results is presented for waves propagating along the pure mode directions of crystalline silicon.

  8. Use of probiotics for prevention of radiation-induced diarrhea

    Institute of Scientific and Technical Information of China (English)

    P Delia; G Sansotta; V Donate; P Frosina; G Messina; C De Renzis; G Famularo

    2007-01-01

    AIM: To investigate the efficacy of a high-potency probiotic preparation on prevention of radiation-induced diarrhea in cancer patients.METHODS: This was a double-blind, placebo-controlled trial. Four hundred and ninety patients who underwent adjuvant postoperative radiation therapy after surgery for sigmoid, rectal, or cervical cancer were assigned to either the high-potency probiotic preparation VSL#3 (one sachet t.i.d.,) or placebo starting from the first day of radiation therapy. Efficacy endpoints were incidence and severity of radiation-induced diarrhea, daily number of bowel movements, and the time from the start of the study to the use of loperamide as rescue medication.RESULTS: More placebo patients had radiation-induced diarrhea than VSL#3 patients (124 of 239 patients, 51.8%, and 77 of 243 patients, 31.6%; P < 0.001) and more patients given placebo suffered grade 3 or 4 diarrhea compared with VSL#3 recipients (55.4% and 1.4%, P < 0.001). Daily bowel movements were 14.7 ± 6 and 5.1 ± 3 among placebo and VSL#3 recipients (P < 0.05), and the mean time to the use of loperamide was 86 ± 6 h for placebo patients and 122 ± 8 h for VSL#3 patients (P < 0.001).CONCLUSION: Probiotic lactic acid-producing bacteria are an easy, safe, and feasible approach to protect cancer patients against the risk of radiation-induced diarrhea.

  9. QUANTIFYING LOCAL RADIATION-INDUCED LUNG DAMAGE FROM COMPUTED TOMOGRAPHY

    NARCIS (Netherlands)

    Ghobadi, Ghazaleh; Hogeweg, Laurens E.; Faber, Hette; Tukker, Wim G. J.; Schippers, Jacobus M.; Brandenburg, Sytze; Langendijk, Johannes A.; Coppes, Robert P.; van Luijk, Peter

    2010-01-01

    Purpose: Optimal implementation of new radiotherapy techniques requires accurate predictive models for normal tissue complications. Since clinically used dose distributions are nonuniform, local tissue damage needs to be measured and related to local tissue dose. In lung, radiation-induced damage re

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

    International Nuclear Information System (INIS)

    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)

  11. Report of board IV: Radiation damages and radiation induced diseases

    International Nuclear Information System (INIS)

    Board IV (radiation damage and radiation-induced diseases) worked on the effects of ionizing radiation on living organisms and studies the radiation damage it entailed. Investigations with cells or model systems serve to recognize certain causal relationships in an organism out of the diversity of reactions encountered. (orig./AK)

  12. 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

  13. The progress in research on the mechanism, prevention and treatment of radiation-induced lung injury

    International Nuclear Information System (INIS)

    During radiotherapy of chest tumor,many patients often develop radiation-induced lung injury (including radiation induced interstitial pneumonia or pulmonary fibrosis), which significantly affects their quality of life. Therefore, it is very important to study the mechanism, prevention, and treatment of radiation-induced lung injury. Herein a review of recent research advances in radiation-induced lung injury is made, in order to provide theoretical basis for further research. (authors)

  14. Unusual progression and subsequent improvement in cystic lung disease in a child with radiation-induced lung injury

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Michael S. [Monroe Carell Jr. Children' s Hospital at Vanderbilt, Department of Pediatrics, Nashville, TN (United States); Chadha, Ashley D. [Vanderbilt University School of Medicine, Division of Pulmonary Medicine, Department of Pediatrics, Nashville, TN (United States); Carroll, Clinton M.; Borinstein, Scott C. [Vanderbilt University School of Medicine, Division of Hematology and Oncology, Department of Pediatrics, Nashville, TN (United States); Young, Lisa R. [Vanderbilt University School of Medicine, Division of Pulmonary Medicine, Department of Pediatrics, Nashville, TN (United States); Vanderbilt University School of Medicine, Division of Allergy, Pulmonary and Critical Care, Department of Medicine, Nashville, TN (United States); Vanderbilt University School of Medicine, Division of Pulmonary Medicine, Nashville, TN (United States)

    2015-07-15

    Radiation-induced lung disease is a known complication of therapeutic lung irradiation, but the features have not been well described in children. We report the clinical, radiologic and histologic features of interstitial lung disease (ILD) in a 4-year-old child who had previously received lung irradiation as part of successful treatment for metastatic Wilms tumor. Her radiologic abnormalities and clinical symptoms developed in an indolent manner. Clinical improvement gradually occurred with corticosteroid therapy. However, the observed radiologic progression from interstitial and reticulonodular opacities to diffuse cystic lung disease, with subsequent improvement, is striking and has not been previously described in children. (orig.)

  15. Unusual progression and subsequent improvement in cystic lung disease in a child with radiation-induced lung injury

    International Nuclear Information System (INIS)

    Radiation-induced lung disease is a known complication of therapeutic lung irradiation, but the features have not been well described in children. We report the clinical, radiologic and histologic features of interstitial lung disease (ILD) in a 4-year-old child who had previously received lung irradiation as part of successful treatment for metastatic Wilms tumor. Her radiologic abnormalities and clinical symptoms developed in an indolent manner. Clinical improvement gradually occurred with corticosteroid therapy. However, the observed radiologic progression from interstitial and reticulonodular opacities to diffuse cystic lung disease, with subsequent improvement, is striking and has not been previously described in children. (orig.)

  16. Depleted uranium and radiation - induced lung cancer and leukaemia

    International Nuclear Information System (INIS)

    Reports of leukaemias and other cancers among servicemen who took part in the 1991 Gulf war or in the more recent operations in the Balkans are of continuing interest, as is the possibility, however slight, that depleted uranium (DU) is one of the causative factors. This commentary includes the results of a UK epidemiological study on the mortality of Gulf war veterans and , although not containing information on DU exposure, gives data on overall levels of mortality and therefore carries more weight than anecdotal reports. Also included are brief summaries on radiation-induced lung cancer in uranium workers as well as radiation-induced leukaemia in Japanese atomic bomb survivors and patients ankylosing spondylitis treated using x-rays. This commentary concludes with a critique of Iraqi cancer statistics as well as giving information on environmental contamination in Kosovo and the use of DU ammunition. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-06-01

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

  18. Caffeine Markedly Enhanced Radiation-Induced Bystander Effects

    Institute of Scientific and Technical Information of China (English)

    JIANG Erkang; WU Lijun

    2009-01-01

    A bstract In this paper it is shown that incubation with 2 mM caffeine enhanced significantly the MN (micronucleus) formation in both the 1 cGy a-particle irradiated and non-irradiated by- stander regions. Moreover, caffeine treatment made the non-irradiated bystander cells more sensi- tive 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 a-particle radiation-induced damage in ir- radiated and non-irradiated bystander regions, and therefore it is important to investigate the relationship between the radiosensitizer and radiation-induced bystander effects (RIBE).

  19. Radiation-induced hemorrhagic duodenitis associated with sorafenib treatment.

    Science.gov (United States)

    Yanai, Shunichi; Nakamura, Shotaro; Ooho, Aritsune; Nakamura, Shigeo; Esaki, Motohiro; Azuma, Koichi; Kitazono, Takanari; Matsumoto, Takayuki

    2015-06-01

    Sorafenib, an oral inhibitor of multiple tyrosine kinase receptors, has been widely used as a standard medical treatment for advanced hepatocellular carcinoma (HCC). Here, we report a 66-year-old male patient who developed gastrointestinal bleeding due to radiation-induced hemorrhagic duodenitis associated with sorafenib treatment. We started oral administration of sorafenib because of the recurrence of HCC with lung metastases. The patient had been treated by radiotherapy for para-aortic lymph node metastases from HCC 4 months before the bleeding. Esophagogastroduodenoscopy (EGD) revealed edematous reddish mucosa with friability and telangiectasia in the second portion of the duodenum. Computed tomography and capsule endoscopy revealed that the hemorrhagic lesions were located in the distal duodenum. After discontinuation of sorafenib, the bleeding disappeared and a follow-up EGD confirmed improvement of duodenitis. Based on these findings, the diagnosis of radiation-induced hemorrhagic duodenitis associated with sorafenib was made. PMID:25832768

  20. A new view of radiation-induced cancer

    OpenAIRE

    Shuryak, I.; Sachs, R K; Brenner, D J

    2010-01-01

    Biologically motivated mathematical models are important for understanding the mechanisms of radiation-induced carcinogenesis. Existing models fall into two categories: (1) short-term formalisms, which focus on the processes taking place during and shortly after irradiation (effects of dose, radiation quality, dose rate and fractionation), and (2) long-term formalisms, which track background cancer risks throughout the entire lifetime (effects of age at exposure and time since exposure) but m...

  1. Radiation-induced defect formation in chalcogenide glasses

    Energy Technology Data Exchange (ETDEWEB)

    Shpotyuk, O.I.; Filipecki, J. [Physics Institute of Pedagogical University of Czestochowa, Al. Armii Krajowej 13/15, Czestochowa 42201 (Poland); Kozdras, A. [Physics Laboratory of Opole Technical University, 75 ul. Ozimska, Opole, PL-45370 (Poland); Kavetskyy, T.S. [Lviv Scientific Research Institute of Materials of Scientific Research Company ' Carat' , Stryjska Str. 202, Lviv, UA-79031 (Ukraine)

    2003-10-01

    The modified model of native and radiation-induced microvoid-type positron traps in vitreous chalcogenide semiconductors is developed to explain compositional features of positron annihilation lifetime measurements in stoichiometric As{sub 2}S{sub 3}-GeS{sub 2} and non-stoichiometric As{sub 2}S{sub 3}-Ge{sub 2}S{sub 3} chalcogenide glasses before and after {gamma}-irradiation.

  2. Radiation-induced morphea of the breast: a case report

    Directory of Open Access Journals (Sweden)

    Cheah Nellie LC

    2008-04-01

    Full Text Available Abstract Radiation-induced morphea (RIM of the breast is a rare complication of radiotherapy. It is disfiguring, painful and defeats the purpose of achieving a good cosmesis in breast-conservation surgery. This report describes a severe case of RIM in a breast cancer patient together with photographic illustrations of the serial changes over time and histopathology slides. A review of the literature is provided.

  3. 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...

  4. Radiation-induced myeloid leukemia in murine models

    OpenAIRE

    Rivina, Leena; Davoren, Michael; Schiestl, Robert H.

    2014-01-01

    The use of radiation therapy is a cornerstone of modern cancer treatment. The number of patients that undergo radiation as a part of their therapy regimen is only increasing every year, but this does not come without cost. As this number increases, so too does the incidence of secondary, radiation-induced neoplasias, creating a need for therapeutic agents targeted specifically towards incidence reduction and treatment of these cancers. Development and efficacy testing of these agents requires...

  5. Rabbit model of radiation-induced lung injury

    Institute of Scientific and Technical Information of China (English)

    Zhen-Zong Du; Hua Ren; Jian-Fei Song; Li-Fei Zhang; Feng Lin; Hai-Yong Wang

    2013-01-01

    Objective:To explore the feasibility of establishing an animal model of chronic radiation-induced lung injury.Methods:Twenty-eightNewZealand white rabbits were randomly divided into3 groups(the right lung irradiation group, the whole lung irradiation group and the control group).Animal model of radiation-induced lung injury was established by high-does radiotherapy in the irradiation groups, then all rabbits underwentCT and pathological examinations at1,2,4,8,12,16 weeks, respectively after radiation.Results:Within4 weeks of irradiation, some rabbits in the right lung irradiation group and whole lung irradiation group died. CT and pathological examinations all showed acute radiation pneumonitis.At8-12 weeks after irradiation,CT scanning showed ground glass samples signs, patchy shadows and fibrotic stripes. Pathological examination showed the fibrosis pulmonary alveolar wall thickened obviously. Conclusions:The clinical animal model of chronic radiation-induced lung injury which corresponds to practical conditions in clinic can be successfully established.

  6. Clarithromycin Attenuates Radiation-Induced Lung Injury in Mice.

    Directory of Open Access Journals (Sweden)

    Seung Jun Lee

    Full Text Available Radiation-induced lung injury (RILI is a common and unavoidable complication of thoracic radiotherapy. The current study was conducted to evaluate the ability of clarithromycin (CLA to prevent radiation-induced pneumonitis, oxidative stress, and lung fibrosis in an animal model. C57BL/6J mice were assigned to control, irradiation only, irradiation plus CLA, and CLA only groups. Test mice received single thoracic exposures to radiation and/or oral CLA (100 mg/kg/day. Histopathologic findings and markers of inflammation, fibrosis, and oxidative stress were compared by group. On a microscopic level, CLA inhibited macrophage influx, alveolar fibrosis, parenchymal collapse, consolidation, and epithelial cell changes. The concentration of collagen in lung tissue was lower in irradiation plus CLA mice. Radiation-induced expression of tumor necrosis factor (TNF-α, TNF receptor 1, acetylated nuclear factor kappa B, cyclooxygenase 2, vascular cell adhesion molecule 1, and matrix metallopeptidase 9 were also attenuated by CLA. Expression levels of nuclear factor erythroid 2-related factor 2 and heme oxygenase 1, transforming growth factor-β1, connective tissue growth factor, and type I collagen in radiation-treated lungs were also attenuated by CLA. These findings indicate that CLA ameliorates the deleterious effects of thoracic irradiation in mice by reducing pulmonary inflammation, oxidative damage, and fibrosis.

  7. Clarithromycin Attenuates Radiation-Induced Lung Injury in Mice.

    Science.gov (United States)

    Lee, Seung Jun; Yi, Chin-ok; Heo, Rok Won; Song, Dae Hyun; Cho, Yu Ji; Jeong, Yi Yeong; Kang, Ki Mun; Roh, Gu Seob; Lee, Jong Deog

    2015-01-01

    Radiation-induced lung injury (RILI) is a common and unavoidable complication of thoracic radiotherapy. The current study was conducted to evaluate the ability of clarithromycin (CLA) to prevent radiation-induced pneumonitis, oxidative stress, and lung fibrosis in an animal model. C57BL/6J mice were assigned to control, irradiation only, irradiation plus CLA, and CLA only groups. Test mice received single thoracic exposures to radiation and/or oral CLA (100 mg/kg/day). Histopathologic findings and markers of inflammation, fibrosis, and oxidative stress were compared by group. On a microscopic level, CLA inhibited macrophage influx, alveolar fibrosis, parenchymal collapse, consolidation, and epithelial cell changes. The concentration of collagen in lung tissue was lower in irradiation plus CLA mice. Radiation-induced expression of tumor necrosis factor (TNF)-α, TNF receptor 1, acetylated nuclear factor kappa B, cyclooxygenase 2, vascular cell adhesion molecule 1, and matrix metallopeptidase 9 were also attenuated by CLA. Expression levels of nuclear factor erythroid 2-related factor 2 and heme oxygenase 1, transforming growth factor-β1, connective tissue growth factor, and type I collagen in radiation-treated lungs were also attenuated by CLA. These findings indicate that CLA ameliorates the deleterious effects of thoracic irradiation in mice by reducing pulmonary inflammation, oxidative damage, and fibrosis. PMID:26114656

  8. Diagnosis and operative treatment of radiation-induced brachial plexopathy

    Institute of Scientific and Technical Information of China (English)

    路来金; 宫旭; 刘志刚; 王东生; 张志新

    2002-01-01

    Objective: To explore the diagnosis and operative treatment of radiation-induced brachial plexopathy. Methods: Nine cases of radiation-induced brachial plexopathy were divided into two groups, 4 cases undergoing neurolysis of brachial plexus as Group A and 5 cases undergoing transfer of myocutaneous flaps after neurolysis as Group B. In Group B, 4 cases were treated with latissimus dorsi myocutaneous flaps (about 20 cm×20 cm) and 1 case with pectoralis major myocutaneous flap (about 8 cm×6 cm). Results: All the 9 cases of radiation-induced brachial plexopathy were followed up for a period of 2 to 5 years, with an average of 2.3 years. As far as pain relief and function recovery were concerned, the results of Group B were better than those of Group A.Conclusions: Based on the results of Group B in the series, we suggest that the procedure of covering the wounds with transferred myocutaneous flaps after neurolysis of the brachial plexus should be performed to those advanced patients. The procedure may improve the blood supply of the fibrotic brachial plexus by reestablishing a good nerve bed.

  9. The role of Fas in radiation induced apoptosis in vivo

    International Nuclear Information System (INIS)

    It has been recognized that interaction of the Fas: Fas ligand plays an important role in radiation-induced apoptosis. The purpose of this study was to investigate the role of Fas mutation in radiation-induced apoptosis in vivo. Mice with mutations in Fas, MRL/Mpj Faslpr, and its normal control, MRL/Mpj, were used in this study. Eight-week old male mice were given whole body radiation. After irradiation, the mice were killed and their spleens were collected at different time intervals. Tissue samples were stained with hematoxylin-eosin and the numbers of apoptotic cells were scored. Regulating molecules of apoptosis including p53, Bcl-2, Bax, Bcl-XL, and Bcl-Xs were also analyzed by Western blotting. At 25 Gy irradiation, the level of apoptosis reached the peak value at 8 hr after radiation and recovered to the normal value at 24 hr after radiation in MRL/Mpj mice. In contrast, the peak apoptosis level appeared at 4 hr after radiation in MRL/Mpj-Faslpr mice. At 8 hr after radiation, the levels of apoptosis in MRL/Mpj mice and MRL/Mpj-Faslpr mice were 52.3 ± 7.8% and 8.0 ± 8.6%, respectively (ρ L, and Bcl-Xs, increased in MRL/Mpj mice in response to radiation; p53 with a peak level of 3-fold at 8 h, Bcl-XL with a peak level of 3.3-fold at 12 h, and Bcl-Xs with a peak level of 3-fold at 12 h after 25 Gy radiation. Bcl-2 and Bax did not show significant change in MRL/Mpj mice. However in MRL/Mpj-Faslpr mice, the expression levels of p53, Bcl-2, Bax, Bcl-XL, and Bcl-Xs showed no significant change. The level of radiation-induced apoptosis was lower in Fas mutated mice, lpr, than in control mice. This seemed to be related to the lack of radiation-induced p53 activation in the lpr mice. This result suggests that Fas plays an important role in radiation-induced apoptosis in vivo

  10. 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

  11. p53-dependent apoptosis suppresses radiation-induced teratogenesis

    International Nuclear Information System (INIS)

    About half of human conceptions are estimated not to be implanted in the uterus, resulting in unrecognizable spontaneous abortions. Experimental studies with mice have established that irradiation during the preimplantation period of the embryo induces a high incidence of prenatal deaths but virtually no malformations. This suggests that some mechanism is screening out the damaged fetuses. In order to elucidate the mechanisms of tissue repair of radiation-induced teratogenic injury, we compared the incidences of radiation-induced malformations and abortions in p53 null (p53-/-) and wild-type (p53+/+) mice. After X-irradiation with 2 Gy on day 9.5 of gestation, p53-/- mice showed a 70% incidence of anomalies and a 7% incidence of deaths, whereas p53+/+ mice had a 20% incidence of anomalies and a 60% incidence of deaths. Similar results were obtained after irradiation on day 3.5 of gestation. This reciprocal relationship of radiosensitivity to anomalies and to embryonic or fetal lethality supports the notion that the p53 gene protects embryos and fetuses against the teratogenic effects of radiation by eliminating cells that have been badly damaged. In fact, after X-irradiation, the frequency of dying cells by apoptosis was greatly increased in tissues of the p53+/+ fetuses but not at all in those of the p53-/- fetuses. Mammals are protected from radiation-induced injury by two mechanisms, p53-dependent apoptotic tissue repair in addition to well known DNA repair. Therefore, there are threshold doses below which there is no induction of teratogenic and carcinogenic effects after exposure to low-level radiation. (author)

  12. Measurements of prompt radiation induced conductivity of Kapton.

    Energy Technology Data Exchange (ETDEWEB)

    Preston, Eric F. (ITT Corporation, Colorado Springs, CO); Zarick, Thomas Andrew; Sheridan, Timothy J.; Hartman, E. Frederick; Stringer, Thomas Arthur (ITT Corporation, Colorado Springs, CO)

    2010-10-01

    We performed measurements of the prompt radiation induced conductivity in thin samples of Kapton (polyimide) at the Little Mountain Medusa LINAC facility in Ogden, UT. Three mil samples were irradiated with a 0.5 {mu}s pulse of 20 MeV electrons, yielding dose rates of 1E9 to 1E10 rad/s. We applied variable potentials up to 2 kV across the samples and measured the prompt conduction current. Analysis rendered prompt conductivity coefficients between 6E-17 and 2E-16 mhos/m per rad/s, depending on the dose rate and the pulse width.

  13. Sensitization of radiation-induced cell death by genistein

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Rim; Kim, In Gyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-03-15

    A number of epidemiological studies as well as biological experiments, showed that genistein, one of the isoflavone, prevents prostate cancer occurrence. In this study, we showed that genistein inhibited the cell proliferation of human promyeoltic leukemia HL-60 cells and induced G2/M phase arrest. In addition, combination of genistein treatment and {gamma}-irradiation displayed synergistic effect in apoptotic cell death of HL-60 cells. This means that the repair of genistein-induced DNA damage was hindered by {gamma}-irradiation and thus cell death was increased. In conclusion, genistein is one of the important chemicals that sensitize radiation-induced cell death.

  14. Inducible HSP70 Protects Radiation-Induced Salivary Gland Damage

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hae-June; Lee, Yoon-Jin; Kwon, Hee-Choong; Lee, Su-Jae; Bae, Sang-Woo; Lee, Yun-Sil [Korea Institute of Radiological Medical Sciences, Seoul (Korea, Republic of); Kim, Sung-Ho [Chonnam National University, Gwangju (Korea, Republic of)

    2006-07-01

    Irradiation (IR) delivered to the head and neck is a common treatment for malignancies. Salivary glands in the irradiation field are severely damaged, and consequently this resulted in marked salivary hypofunction. While the exact mechanism of salivary gland damage remains enigmatic, fluid secreting acinar cells are lost, and saliva output is dramatically reduced. Previously we have reported that inducible heat shock protein 70 (HSP70i) induced radioresistance in vitro. Moreover, HSP70i localized to salivary glands by gene transfer has great potential for the treatment of salivary gland. Herein, we investigated whether HSP70 can use as radio protective molecules for radiation-induced salivary gland damage in vivo.

  15. Transient radiation-induced absorption in laser materials

    Science.gov (United States)

    Brannon, Paul J.

    1994-06-01

    Transient radiation-induced absorption losses in laser materials have been measured using a pulsed nuclear reactor. Reactor pulse widths of 70 to 90 microsecond(s) and absorbed doses of 1 to 7.5 krad have been used. Transmission recovery times and peak absorption coefficients are given. Materials tested include LiNbO3, GSGG, silica substrates, and filter glasses used in the laser cavity. The filter glasses are tested at discrete wavelengths in the range 440 - 750 nm. Lithium niobate, MgO-doped LiNbO3, GSGG, and the silica substrates are tested at 1061 nm.

  16. Transient radiation-induced absorption in laser materials

    Energy Technology Data Exchange (ETDEWEB)

    Brannon, P.J.

    1994-12-31

    Transient radiation-induced absorption losses in laser materials have been measured using a pulsed nuclear reactor. Reactor pulse widths of 70 to 90 {mu}s and absorbed doses of 1 to 7.5 krad have been used. Transmission recovery times and peak absorption coefficients are given. Materials tested include LiNbO{sub 3}, GSGG, silica substrates, and filter glasses used in the laser cavity. The filter glasses are tested at discrete wavelengths in the range 440--750 nm. Lithium niobate , MgO doped LiNbO{sub 3}, GSGG, and the silica substrates are tested at 1061 nm.

  17. Pathology and biology of radiation-induced cardiac disease

    Science.gov (United States)

    Tapio, Soile

    2016-01-01

    Heart disease is the leading global cause of death. The risk for this disease is significantly increased in populations exposed to ionizing radiation, but the mechanisms are not fully elucidated yet. This review aims to gather and discuss the latest data about pathological and biological consequences in the radiation-exposed heart in a comprehensive manner. A better understanding of the molecular and cellular mechanisms underlying radiation-induced damage in heart tissue and cardiac vasculature will provide novel targets for therapeutic interventions. These may be valuable for individuals clinically or occupationally exposed to varying doses of ionizing radiation. PMID:27422929

  18. Radiation-induced cationic curing of vinyl ethers

    International Nuclear Information System (INIS)

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

  19. The thermal stability of radiation-induced defects in illite

    Science.gov (United States)

    Riegler, T.; Allard, T.; Beaufort, D.; Cantin, J.-L.; von Bardeleben, H. J.

    2016-01-01

    High-purity illite specimens from the Mesoproterozoic unconformity-related uranium deposits of Kiggavik, Thelon basin, Nunavut (Canada), and Shea Creek (Athabasca basin, Saskatchewan, Canada) have been studied using electron paramagnetic resonance spectroscopy to determine the thermal stability of the main radiation-induced defects and question the potential of using illite as a natural dosimeter. The observed spectra are complex as they can show in the same region several contributions: (1) an unstable native defect, (2) the main stable defect named Ai by reference to a previous study (Morichon et al. in Phys Chem Minerals 35:339-346, 2008), (3) a signal at g = 2.063 assigned to a new defect, not yet fully characterized, named Ai2 center and (4) impurities such as vanadyl complex or divalent manganese. Isochronal heating shows that the new signal corresponds to a stable species. Isothermal heating experiments at 400 and 450 °C provide values of half-life extrapolated at room temperature and activation energy of 1.9-29,109 years and 1.3-1.4 eV, respectively, corresponding to the Ai center. These parameters allow the use of stable radiation-induced defects as a record of radioactivity down to the Paleoproterozoic period.

  20. Radiation induced effects in the developing central nervous system

    International Nuclear Information System (INIS)

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

  1. Neurolysis and myocutaneous flap for radiation induced brachial plexus neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Hirachi, Kazuhiko; Minami, Akio; Kato, Hiroyuki; Nishio, Yasuhiko [Hokkaido Univ., Sapporo (Japan). School of Medicine; Ohnishi, Nobuki

    1998-11-01

    Surgical treatment for radiation induced brachial plexus neuropathy is difficult. We followed 9 patients of radiation induced brachial plexus neuropathy who were surgically treated with neurolysis and myocutaneous flap coverage. Their ages ranged from 29 to 72 years old. Their diagnoses were breast cancer in 6 patients, lingual cancer in 1, thyroid cancer in 1 and malignant lymphoma in 1. Total dose of radiation ranged from 44 to 240 Gy. Interval from radiation therapy to our surgery ranged from 1 to 18 years (mean 6.7 years). Chief complaints were dysesthesia in 9 patients, motor weakness in 7 patients and dullach in scar formation of radiated skin in 7 patients. Preoperative neural functions were slight palsy in 1, moderate palsy in 5 and complete palsy in 3. In surgical treatment, neurolysis of the brachial plexus was done and it was covered by latissimus dorsi myocutaneous flap. We evaluated about dysesthesia and motor recovery after treatment for neuropathy. Follow up periods ranged from 1 to 11 years (average in 5 years). Dysesthesia improved in 6 patients and got worse in 3 patients. Motor weakness recovered in only 2 patients and got worse in 7 patients. From our results, intolerable dysesthesia which was first complaint of these patients improved. But motor function had not recovered. Our treatment was thought to be effective for extraneural factor like an compression neuropathy by scar formation and poor vascularity. But it was not effective for intraneural damage by radiation therapy. (author)

  2. Radiation-induced segregation in Cu-Au alloys

    International Nuclear Information System (INIS)

    Radiation-induced segregation in a Cu-1 at. % Au alloy was investigated using in situ Rutherford Backscattering Spectrometry. Irradiation with 1.8-MeV He produced nonequilibrium Au atom depletion in the near surface region. The amount of segregation was measured as a function of dose, dose rate and temperature. Segregation was observed between 300 and 5000C. For a calculated dose rate of 3.9 x 10-5 dpa/s, the radiation-induced segregation rate peaked near 4000C. Theoretical analysis based on the Johnson-Lam model predicted that the amount of segregation would be directly proportional to dose at the early stage of irradiation, would deviate from linearity with a continuously decreasing slope at intermediate doses, and finally approach a constant value after high doses. The analysis also predicted that the segregation rate would vary as the -1/4th power of the dose rate at constant dose in the low temperature region. These predictions were all verified experimentally. A procedure for extracting relative defect production efficiencies from similar measurements is discussed

  3. Sensitivity to Radiation-Induced Cancer in Hemochromatosis

    Energy Technology Data Exchange (ETDEWEB)

    Bull. Richard J.; Anderson, Larry E.

    2000-06-01

    The objectives of this pilot project using HFE-knockout homozygotes and heterozygotes are to (1) determine whether the knock-out mice have greater sensitivity to radiation-induced cancer of the colon, liver and breast, (2) establish the dependence of this sensitivity on the accumulation of iron, (3) determine the extent to which cell replication and apoptosis occur in these target tissues with varying iron load, and (4) correlate the increases in sensitivity with changes in insulin-related signaling in tumors and normal tissue from each target organ. Three experimental designs will be used in the pilot project. The sequence of experiments is designed to first explore the influence of iron load on the response and demonstrate that HFE knockout mice are more sensitive than the wild type to radiation-induced cancer in one or more of three target tissues (liver, colon and breast). The dose response relationships with a broader set of radiation doses will be explored in the second experiment. The final experiment is designed to explore the extent to which heterozygotes display the increased susceptibility to cancer induction and to independently assess the importance of iron load to the initiation versus promotion of tumors.

  4. Characterization of radiation-induced emesis in the ferret

    Energy Technology Data Exchange (ETDEWEB)

    King, G.L.

    1988-06-01

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

  5. Characterization of radiation-induced emesis in the ferret

    Energy Technology Data Exchange (ETDEWEB)

    King, G.L.

    1988-01-01

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

  6. Ionizing Radiation Induces HMGB1 Cytoplasmic Translocation and Extracellular Release

    Institute of Scientific and Technical Information of China (English)

    Lili Wang; Li He; Guoqiang Bao; Xin He; Saijun Fan; Haichao Wang

    2016-01-01

    Objective A nucleosomal protein,HMGBI,can be secreted by activated immune cells or passively released by dying cells,thereby amplifying rigorous inflammatory responses.In this study we aimed to test the possibility that radiation similarly induces cytoplasmic HMGB1 translocation and release.Methods Human skin fibroblast (GM0639) and bronchial epithelial (16HBE) cells and rats were exposed to X-ray radiation,and HMGB1 translocation and release were then assessed by immunocytochemistry and immunoassay,respectively.Results At a wide dose range(4.0-12.0 Gy),X-ray radiation induced a dramatic cytoplasmic HMGB1 translocation,and triggered a time-and dose-dependent HMGB1 release both in vitro and in vivo.The radiation-mediated HMGB1 release was also associated with noticeable chromosomal DNA damage and loss of cell viability.Conclusions Radiation induces HMGB1 cytoplasmic translocation and extracellular release through active secretion and passive leakage processes.

  7. UV-radiation-induced degradation of fluorinated polyimide films

    Science.gov (United States)

    Chang, Li-Hsin; Saha, Naresh C.

    1994-12-01

    Fully cured fluorinated polyimide (FPI) films with low dielectric constants ( less than or equal to 3.0) have been found to be chemically altered when exposed to UV radiation during a process integration study. This chemical modification is manifested in the loss of film thickness after it is subjected to UV radiation followed by photoresist stripping. The UV-radiation-induced surface modifications of the FPI film have been characterized by X-ray photoelectron spectroscopy (XPS). The XPS data show the presence of C=O and COO(-) sites in the FPI molecule following UV exposure. Under prolonged UV exposure in a stepper, the FPI film acts as a positive working photoresist. However, a 2 kA plasma enhanced chemically vapor-deposited oxide mask and/or a typical 12 kA photoresist mask effectively shields the FPI from UV-radiation-induced degradation. The effects of FPI on UV radiation present during other normal wafer processing steps such as plasma deposition and reactive ion-etching were also studied and found to be negligible.

  8. Radiation-induced genomic instability in Caenorhabditis elegans.

    Science.gov (United States)

    Huumonen, Katriina; Immonen, Hanna-Kaisa; Baverstock, Keith; Hiltunen, Mikko; Korkalainen, Merja; Lahtinen, Tapani; Parviainen, Juha; Viluksela, Matti; Wong, Garry; Naarala, Jonne; Juutilainen, Jukka

    2012-10-01

    Radiation-induced genomic instability has been well documented, particularly in vitro. However, the understanding of its mechanisms and their consequences in vivo is still limited. In this study, Caenorhabditis elegans (C. elegans; strain CB665) nematodes were exposed to X-rays at doses of 0.1, 1, 3 or 10Gy. The endpoints were measured several generations after exposure and included mutations in the movement-related gene unc-58, alterations in gene expression analysed with oligoarrays containing the entire C. elegans genome, and micro-satellite mutations measured by capillary electrophoresis. The progeny of the irradiated nematodes showed an increased mutation frequency in the unc-58 gene, with a maximum response observed at 1Gy. Significant differences were also found in gene expression between the irradiated (1Gy) and non-irradiated nematode lines. Differences in gene expression did not show clear clustering into certain gene categories, suggesting that the instability might be a chaotic process rather than a result of changes in the function of few specific genes such as, e.g., those responsible for DNA repair. Increased heterogeneity in gene expression, which has previously been described in irradiated cultured human lymphocytes, was also observed in the present study in C. elegans, the coefficient of variation of gene expression being higher in the progeny of irradiated nematodes than in control nematodes. To the best of our knowledge, this is the first publication reporting radiation-induced genomic instability in C. elegans.

  9. The redox homeostasis system in radiation-induced genome instability

    International Nuclear Information System (INIS)

    The participation of the redox homeostasis system in the formation of the radiation-induced genome instability and new data of literature, that give a direct evidence the presence of this instability in vivo, is considered. The O2- radical, H2O2 and NO radical role as signal molecules, that trigger the cascade of active responses to change of redox status of the cells, are discussed. The reactive oxygen species (ROS) reorganize the membrane physico-chemical system of cell metabolism regulation. The data about changes in ROS generation system, including NO, that lead to genome instability after ionizing irradiation even in low doses, are analyzed. It is noted, that the radiation-induced genome instability and ROS production increase may be observed both in direct irradiated cells and their progeny and in the cells, that are not find oneself in ionization tracks, and their progeny. There evidences that the genome instability of irradiated cell progeny is maintained by the increases ROS production

  10. Radiation-induced electron migration in nucleic acids

    International Nuclear Information System (INIS)

    Radiation-induced electron migration along DNA is a mechanism by which randomly produced stochastic energy deposition events can lead to non-random types of damage along DNA manifested distal to the sites of the initial energy deposition. Radiation-induced electron migration in nucleic acids has been examined using oligonucleotides containing 5-bromouracil (5-BrU). Interaction of 5-BrU with solvated electrons results in release of bromide ions and formation of uracil-5-yl radicals. Monitoring either bromide ion release or uracil formation provides an opportunity to study electron migration processes in model nucleic acid systems. Using this approach we have discovered that electron migration along oligonucleotides is significantly influenced by the base sequence and strandedness. Migration along 7 base pairs in oligonucleotides containing guanine bases was observed for oligonucleotides irradiated in solution, which compares with mean migration distances of 6-10 bp for Escherichia coli DNA irradiated in solution and 5.5 bp for E. coli DNA irradiated in cells. Evidence also suggests that electron migration can occur preferentially in the 5' to 3' direction along a double-stranded oligonucleotide containing a region of purine bases adjacent to the 5-BrU moiety. Our continued efforts will provide information regarding the contribution of electron transfer along DNA to formation of locally multiply damaged sites created in DNA by exposure to ionizing radiation. (Author)

  11. Radiation-induced apoptosis in undifferentiated cells of the developing brain as a biological defense mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Inouye, Minioru [Nagoya Univ. (Japan). Research Inst. of Environmental Medicine; Tamaru, Masao

    1994-12-31

    Undifferentiated neural (UN) cells of the developing mammalian brain are highly sensitive to the lethal effects of ionizing radiation. Nuclear and cytoplasmic condensation, transglutaminase activation, and internucleosomal DNA cleavage reveal radiation-induced cell death in the ventricular zone of the cerebral mantle and external granular layer of the cerebellum to be due to apoptosis. A statistically significant increase of cell mortality can be induced by 0.03 Gy X-irradiation, and the mortality increases linearly with increasing doses. It is not changed by split doses, probably because of the very slow repair of cellular damage and a lack of adaptive response. Although extensive apoptosis in the UN cell population results in microcephaly and mental retardation, it possesses the ability to recover from a considerable cell loss and to form the normal structure of the central nervous system. The number of cell deaths needed to induce tissue adnormalities in the adult murine brain rises in the range of 15-25% of the germinal cell population; with the threshold doses at about 0.3 Gy for cerebral anomalies and 1 Gy for cerebellar abnormalities. Threshold level is similarly suggested in prenatally exposed A-bomb survivors. High radiosensitivity of UN cells is assumed to be a manifestation of the ability of the cell to commit suicide when injured. Repeated replication of DNA and extensive gene expression are required in future proliferation and differentiation. Once an abnormality in DNA was induced and fixed in the UN cell, it would be greatly amplified and prove a danger in producing malformations and tumors. These cells would thus commit suicide for the benefit of the individual to eliminate their acquired genetic abnormalities rather than make DNA repair. UN cells in the developing brain are highly radiosensitive and readily involved in apoptosis. Paradoxically, however, this may be to protect individuals against teratogenesis and tumorigenesis. (J.P.N.).

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

    Science.gov (United States)

    Matsumoto, H.; Ohnishi, T.

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

  13. Radiatively induced breaking of conformal symmetry in a superpotential

    Science.gov (United States)

    Arbuzov, A. B.; Cirilo-Lombardo, D. J.

    2016-07-01

    Radiatively induced symmetry breaking is considered for a toy model with one scalar and one fermion field unified in a superfield. It is shown that the classical quartic self-interaction of the superfield possesses a quantum infrared singularity. Application of the Coleman-Weinberg mechanism for effective potential leads to the appearance of condensates and masses for both scalar and fermion components. That induces a spontaneous breaking of the initial classical symmetries: the supersymmetry and the conformal one. The energy scales for the scalar and fermion condensates appear to be of the same order, while the renormalization scale is many orders of magnitude higher. A possibility to relate the considered toy model to conformal symmetry breaking in the Standard Model is discussed.

  14. Radiatively Induced Breaking of Conformal Symmetry in a Superpotential

    CERN Document Server

    Arbuzov, A B

    2015-01-01

    Radiatively induced symmetry breaking is considered for a toy model with one scalar and one fermion field unified in a superfield. It is shown that the classical quartic self-interaction of the superfield possesses a quantum infrared singularity. Application of the Coleman-Weinberg mechanism for effective potential leads to the appearance of condensates and masses for both scalar and fermion components. That induces a spontaneous breaking of the initial classical symmetries: the supersymmetry and the conformal one. The energy scales for the scalar and fermion condensates appear to be of the same order, while the renormalization scale is many orders of magnitude higher. A possibility to relate the considered toy model to conformal symmetry breaking in the Standard Model is discussed.

  15. Binding of radiation-induced phenylalanine radicals to DNA

    International Nuclear Information System (INIS)

    When an aqueous solution of double-stranded DNA of bacteriophage PM2 containing phenylalanine and saturated with N2O is irradiated with γ-rays, radiation-induced phenylalanine radicals are bound covalently. Under the conditions used about 25 phenylalanine molecules may be bound per lethal hit. Also for single-stranded PM2 DNA, most of the phenylalanine radicals bound are non-lethal. Evidence is presented that in double-stranded DNA an appreciable fraction of the single-strand breaks is induced by phenylalanine radicals. Radiation products of phenylalanine and the phenylalanine bound to the DNA decrease the sensitivity of the DNA to the induction of single-strand breaks. There are indications that the high efficiency of protection by radiation products of phenylalanine is due to their positive charge, which will result in a relatively high concentration of these compounds in the vicinity of the negatively charged DNA molecules

  16. Radiation-induced pulsed conductivity of CsBr crystals

    CERN Document Server

    Aduev, B P; Shvajko, V N

    2001-01-01

    The radiation-induced conductivity of the CsBr crystals by excitation through the picosecond electron beams (0.2 MeV, 50 ps, 0.1-10 kA/cm sup 2) are studied. The time resolution of the measurement methodology is approx 150 ps. It is shown that the service life of the conductivity zone electrons is limited by the biomolecular recombination with auto localized holes (V sub k -centers). The inertia of the conductivity current pulse growth is determined. The model, according to which the Auger recombination of the valence zone electrons and the upper skeleton zone holes significantly contributes to the conductivity zone electrons generation, is used for explaining this effect

  17. Radiation-induced radicals in hydrated magnesium sulfate

    International Nuclear Information System (INIS)

    Radiation-induced free radicals in hydrated magnesium sulfate, which are thought to be present on the surface of Europa, one of the Jovian moons, have been studied by electron spin resonance (ESR). ESR signals of both atomic hydrogen (H·) at g = 2.0023 and sulfite radical (SO3−·) at g = 2.0029 are observed in epsomite (MgSO4·7H2O) and in quenched samples of magnesium sulfate solutions, after gamma-ray irradiation at 77 K. Atomic hydrogen disappears at temperatures above 90 K. The sulfite radical starts to decay above 190 K in the quenched sample of 10% magnesium sulfate solution, whereas in epsomite, it is stable even at 260 K. The sulfite radical accumulates at low ambient temperatures, and is a promising candidate for estimating the age of hydrated magnesium sulfate, especially in extraterrestrial environments.

  18. HSP25 Protects Radiation-Induced Salivary Gland Damage

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hae June; Lee, Yoon Jin; Kwon, Hee Choong; Lee, Su Jae; Bae, Sang Woo; Lee, Yun Sil [Korea Institute of Radiological Medical Sciences, Seoul (Korea, Republic of); Kim, Sung Ho [Chonnam National Univ., Gwangju (Korea, Republic of)

    2005-07-01

    Irradiation (IR) is a central treatment modality administered for head and neck malignancies. A significant consequence of this IR treatment is irreversible damage to salivary gland in the IR field. While the exact mechanism of salivary gland damage remains enigmatic, fluid secreting acinar cells are lost, and saliva output is dramatically reduced. Previously we have reported that heat shock protein 25 (HSP25) induced radioresistance in vitro. HSP25 interferes negatively with apoptosis through several pathways which involve its direct interaction with cytochrome c, protein kinase c delta or Akt. And localized gene transfer to salivary glands has great potential for the treatment of salivary gland. Herein, we investigated whether HSP25 can use as radio protective molecules for radiation-induced salivary gland damage in vivo.

  19. Factors that modify risks of radiation-induced cancer

    International Nuclear Information System (INIS)

    The collective influence of biologic and physical factors that modify risks of radiation-induced cancer introduces uncertainties sufficient to deny precision of estimates of human cancer risk that can be calculated for low-dose radiation in exposed populations. The important biologic characteristics include the tissue sites and cell types, baseline cancer incidence, minimum latent period, time-to-tumor recognition, and the influence of individual host (age and sex) and competing etiologic influences. Physical factors include radiation dose, dose rate, and radiation quality. Statistical factors include time-response projection models, risk coefficients, and dose-response relationships. Other modifying factors include other carcinogens, and other biological sources (hormonal status, immune status, hereditary factors)

  20. 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).

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

    Directory of Open Access Journals (Sweden)

    Khan Mubeen

    2009-01-01

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

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

    International Nuclear Information System (INIS)

    The radiation-induced decomposition of 4-chloroaniline (4-ClA) was studied under steady-state conditions using aqueous solutions saturated with air, pure oxygen, N2O, argon and argon in the presence of t-Butanol. Using HPLC-method, the initial G-values of the substrate degradation as well as of a number of radiolytic products were determined. The formation of aminophenols, chlorophenols, aniline and phenol in addition to chloride, ammonia, formaldehyde and mixture of aldehydes as well as carboxylic acids was studied as a function of absorbed dose. Based on the experimental data, probable reaction mechanisms for the degradation of 4-ClA by γ-rays and the formation of the identified products are presented

  3. Probabilistic methodology for estimating radiation-induced cancer risk

    International Nuclear Information System (INIS)

    The RICRAC computer code was developed at Oak Ridge National Laboratory to provide a versatile and convenient methodology for radiation risk assessment. The code allows as input essentially any dose pattern commonly encountered in risk assessments for either acute or chronic exposures, and it includes consideration of the age structure of the exposed population. Results produced by the analysis include the probability of one or more radiation-induced cancer deaths in a specified population, expected numbers of deaths, and expected years of life lost as a result of premature fatalities. These calculatons include consideration of competing risks of death from all other causes. The program also generates a probability frequency distribution of the expected number of cancers in any specified cohort resulting from a given radiation dose. The methods may be applied to any specified population and dose scenario

  4. Radiation induced crystallinity damage in poly(L-lactic acid)

    CERN Document Server

    Kantoglu, O

    2002-01-01

    The radiation-induced crystallinity damage in poly(L-lactic acid) (PLLA) in the presence of air and in vacuum, is studied. From the heat of fusion enthalpy values of gamma irradiated samples, some changes on the thermal properties were determined. To identify these changes, first the glass transition temperature (T sub g) of L-lactic acid polymers irradiated to various doses in air and vacuum have been investigated and it is found that it is independent of irradiation atmosphere and dose. The fraction of damaged units of PLLA per unit of absorbed energy has been measured. For this purpose, SAXS and differential scanning calorimetry methods were used, and the radiation yield of number of damaged units (G(-u)) is found to be 0.74 and 0.58 for PLLA samples irradiated in vacuum and air, respectively.

  5. Factors that modify risks of radiation-induced cancer

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J.I.

    1988-11-01

    The collective influence of biologic and physical factors that modify risks of radiation-induced cancer introduces uncertainties sufficient to deny precision of estimates of human cancer risk that can be calculated for low-dose radiation in exposed populations. The important biologic characteristics include the tissue sites and cell types, baseline cancer incidence, minimum latent period, time-to-tumor recognition, and the influence of individual host (age and sex) and competing etiologic influences. Physical factors include radiation dose, dose rate, and radiation quality. Statistical factors include time-response projection models, risk coefficients, and dose-response relationships. Other modifying factors include other carcinogens, and other biological sources (hormonal status, immune status, hereditary factors).

  6. 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

    used an array of countermeasures (Antioxidant diets and injections) to prevent the radiation-induced bone loss, although these did not prevent bone loss, analysis is ongoing to determine if these countermeasure protected radiation-induced damage to other tissues.

  7. Genetic analysis of radiation-induced mouse thymic lymphomas

    International Nuclear Information System (INIS)

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

  8. 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.).

  9. 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

  10. Radiation-induced meningioma: a distinct molecular genetic pattern?

    Science.gov (United States)

    Shoshan, Y; Chernova, O; Juen, S S; Somerville, R P; Israel, Z; Barnett, G H; Cowell, J K

    2000-07-01

    Radiation-induced meningiomas arise after low-dose irradiation treatment of certain medical conditions and are recognized as clinically separate from sporadic meningioma. These tumors are often aggressive or malignant, they are likely to be multiple, and they have a high recurrence rate following treatment compared with sporadic meningiomas. To understand the molecular mechanism by which radiation-induced meningioma (RIM) arise, we compared genetic changes in 7 RIM and 8 sporadic meningioma (SM) samples. The presence of mutations in the 17 exons of the neurofibromatosis type 2 (NF2) gene, which has been shown to be inactivated in sporadic meningiomas, was analyzed in RIM and SM using single-strand conformation polymorphism (SSCP) and DNA sequencing. In contrast to SM, which showed NF2 mutations in 50% of specimens, no mutations were found in RIM. In addition, Western blot analysis of schwannomin/merlin protein, the NF2 gene product, demonstrated protein levels comparable to normal brain in 4/4 RIM tumor samples analyzed. Loss of heterozygosity (LOH) of genomic regions, which were reported for SM, was also analyzed in all cases of RIM using 22 polymorphic DNA markers. Allele losses were found on chromosomes 1p (4/7), 9p (2/7), 19q (2/7), 22q (2/7), and 18q (1/7). From these observations we conclude that unlike sporadic meningiomas, NF2 gene inactivation and chromosome 22q deletions are far less frequent in RIM, and their role in meningioma development following low dose irradiation is less significant. Other chromosomal lesions, especially loss of 1p, possibly induced by irradiation, may be more important in the development of these tumors. PMID:10901233

  11. Radiation induces aerobic glycolysis through reactive oxygen species

    International Nuclear Information System (INIS)

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

  12. Radiation induced corrosion of copper for spent nuclear fuel storage

    International Nuclear Information System (INIS)

    The long term safety of repositories for radioactive waste is one of the main concerns for countries utilizing nuclear power. The integrity of engineered and natural barriers in such repositories must be carefully evaluated in order to minimize the release of radionuclides to the biosphere. One of the most developed concepts of long term storage of spent nuclear fuel is the Swedish KBS-3 method. According to this method, the spent fuel will be sealed inside copper canisters surrounded by bentonite clay and placed 500 m down in stable bedrock. Despite the importance of the process of radiation induced corrosion of copper, relatively few studies have been reported. In this work the effect of the total gamma dose on radiation induced corrosion of copper in anoxic pure water has been studied experimentally. Copper samples submerged in water were exposed to a series of total doses using three different dose rates. Unirradiated samples were used as reference samples throughout. The copper surfaces were examined qualitatively using IRAS and XPS and quantitatively using cathodic reduction. The concentration of copper in solution after irradiation was measured using ICP-AES. The influence of aqueous radiation chemistry on the corrosion process was evaluated based on numerical simulations. The experiments show that the dissolution as well as the oxide layer thickness increase upon radiation. Interestingly, the evaluation using numerical simulations indicates that aqueous radiation chemistry is not the only process driving the corrosion of copper in these systems. - Highlights: • Copper cubes were exposed to gamma radiation in anoxic pure water. • The dissolution of copper increases with increasing absorbed total dose. • The oxide layer formed consists mainly of cuprite. • Numerical simulations of the irradiation experiments were performed. • There is a large discrepancy between numerical simulations and experimental results

  13. [Radiation-induced cancers: state of the art in 1997].

    Science.gov (United States)

    Cosset, J M

    1997-01-01

    Scientists now have available a large amount of data dealing with radiation-induced neoplasms. These data went back to anecdotal observations which were made in the very first years of utilization of X-rays and radioactive elements. In fact, it is essentially the strict follow-up of the Japanese populations irradiated by the Hiroshima and Nagasaki bombing which allowed a more precise evaluation of the carcinogenicity of ionizing radiations. Further refinements came from therapeutical irradiations: it is now possible to study large cohorts of patients given well-known doses in well-defined volumes and followed for more than 20 years. Last but not least, a significant increase in the incidence and mortality of thyroid cancer has been detected in children contaminated by iodine radioisotopes after the Tchernobyl accident. Recently, some data suggested the emergence of "clusters" of leukemias close to some nuclear facilities, but this question remains highly polemical, both in France and in the UK. Other questions are still waiting for a precise answer; of course, the extrapolation of our available data to very low doses delivered at very low dose rates, but also the carcinogenic risk at high doses. For these "high" doses (about 30 to 70 Gy), a competition between mutagenesis and cell killing was expected, so that these dose levels were expected to be less carcinogenic than lower (a few sieverts) doses. Actually, recent data suggest that the carcinogenic risk goes on increasing up to relatively important doses. In addition, carcinogenic factors, such as tabacco, anticancer chemotherapy and individual susceptibility, are found more and more to be closely intricated with ionizing radiation in the genesis of a given cancer. Even if a number of questions are still pending, the already available data allow specialists, both in medicine and radioprotection, to edict strict rules which can be reasonably expected to have significantly reduced the risk of radiation-induced

  14. Molecular genetic analysis of regions of the murine genome associated with radiation-induced mutations

    International Nuclear Information System (INIS)

    The authors are exploiting the large array of radiation-induced mutations to develop both detailed molecular and functional maps of selected small model regions (as opposed to specific genes) within the mouse genome. Through the integrated use of recombinant DNA technology and classical genetic and cytogenetic analysis, they hope to relate the structure and function of these regions to the study of both normal and abnormal mammalian development. Over the years, the germ-line mutagenesis program has generated a valuable array of induced mutations at several specific loci scattered throughout the murine genome. Many of these mutations are multilocus deletions of chromosomal DNA. Genetic analysis of these types of lesions has detected passenger mutations of wide-ranging effect and severity, and has generated gross functional maps of entire chromosomal regions. They have initiated a program to expand the molecular analysis of these types of deletion mutations. This program exploits the deletion mutations and other chromosomal rearrangements to obtain molecular clones of wild-type DNA that map to regions absent in mutants carrying the deletions. These clones will then be used to correlate the resultant molecular/physical map of the chromosomal region with the genetic/functional map in both mutant and wild-type individuals. Such correlations are essential to a strategy for identifying as many of the genes as possible in a particular region of the genome and for ascertaining their role(s) in the normal development of the mouse

  15. 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.

  16. 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

  17. Industrialization of radiation-induced emulsion polymerization - technological process and its advantages

    International Nuclear Information System (INIS)

    A technological process for industrialization of radiation induced emulsion polymerization was introduced briefly. A batch process rather than a continuous one was adopted in the industrial-scale production. The advantages of radiation induced emulsion polymerization were described in comparison with chemical initiated process. (author)

  18. 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

  19. Influence of radiation induced defect clusters on silicon particle detectors

    International Nuclear Information System (INIS)

    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=1035 cm-2s-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 Φeq=1016 cm-2. The radiation induced bulk damage in silicon sensors will lead to a severe degradation of the performance during their operational time. This work focusses on the improvement of the radiation tolerance of silicon materials (Float Zone, Magnetic Czochralski, epitaxial silicon) based on the evaluation of radiation induced defects in the silicon lattice using the Deep Level Transient Spectroscopy and the Thermally Stimulated Current methods. It reveals the outstanding role of extended defects (clusters) on the degradation of sensor properties after hadron irradiation in contrast to previous works that treated effects as caused by point defects. It has been found that two cluster related defects are responsible for the main generation of leakage current, the E5 defects with a level in the band gap at EC-0.460 eV and E205a at EC-0.395 eV where EC is the energy of the edge of the conduction band. The E5 defect can be assigned to the tri-vacancy (V3) defect. Furthermore, isochronal annealing experiments have shown that the V3 defect exhibits a bistability, as does the leakage current. In oxygen rich material the

  20. Safety consequences of the release of radiation induced stored energy

    International Nuclear Information System (INIS)

    Due to the disposal of HLW in a salt formation gamma energy will be deposited in the rock salt. Most of this energy will be converted into heat, whilst a small part will create defects in the salt crystals. Energy is stored in the damaged crystals. Due to uncertainties in the models and differences in the disposal concepts the estimated values for the stored energy range from 10 to 1000 J/g in the most heavily damaged crystals close to the waste containers. The amount of radiation damage decays exponentially with increasing distance from the containers and at distances larger than 0.2 m the stored energy can be neglected. Given the uncertainties in the model predictions and in the possible release mechanism an instantaneous release of stored energy cannot be excluded completely. Therefore the thermo-mechanical consequences of a postulated instantaneous release of an extremely high amount of radiation induced stored energy have been estimated. These estimations are based on the quasi-static solutions for line and point sources. To account for the dynamic effects and the occurrence of fractures an amplification factor has been derived from mining experience with explosives. A validation of this amplification factor has been given using post experimental observations of two nuclear explosions in a salt formation. For some typical disposal concepts in rock salt the extent of the fractured zone has been estimated. It appeared that the radial extent of the fractured zone is limited to 5 m. Given the much larger distance between the individual boreholes and the distance between the boreholes and the boundary of the salt formation (more than 100 m), the probability of a release of radiation induced stored energy creating a pathway for the nuclides from the containers to the groundwater, is extremely low. The radiological consequences of a groundwater intrusion scenario induced by this very unprobable pathway are bounded by the 'standard' groundwater intrusion

  1. Radiation-induced defects in clay minerals: A review

    Energy Technology Data Exchange (ETDEWEB)

    Allard, Th., E-mail: thierry.allard@impmc.upmc.fr [IMPMC, UMR CNRS 7590, Universite Pierre et Marie Curie, Universite Denis Diderot, IRD, IPGP, Case 115, 4 Place Jussieu, 75005 Paris (France); Balan, E.; Calas, G.; Fourdrin, C.; Morichon, E.; Sorieul, S. [IMPMC, UMR CNRS 7590, Universite Pierre et Marie Curie, Universite Denis Diderot, IRD, IPGP, Case 115, 4 Place Jussieu, 75005 Paris (France)

    2012-04-15

    Extensive information has been collected on radiation effects on clay minerals over the last 35 years, providing a wealth of information on environmental and geological processes. The fields of applications include the reconstruction of past radioelement migrations, the dating of clay minerals or the evolution of the physico-chemical properties under irradiation. The investigation of several clay minerals, namely kaolinite, dickite, montmorillonite, illite and sudoite, by Electron Paramagnetic Resonance Spectroscopy has shown the presence of defects produced by natural or artificial radiations. These defects consist mostly of electron holes located on oxygen atoms of the structure. The various radiation-induced defects are differentiated through their nature and their thermal stability. Most of them are associated with a {pi} orbital on a Si-O bond. The most abundant defect in clay minerals is oriented perpendicular to the silicate layer. Thermal annealing indicates this defect in kaolinite (A-center) to be stable over geological periods at ambient temperature. Besides, electron or heavy ion irradiation easily leads to an amorphization in smectites, depending on the type of interlayer cation. The amorphization dose exhibits a bell-shaped variation as a function of temperature, with a decreasing part that indicates the influence of thermal dehydroxylation. Two main applications of the knowledge of radiation-induced defects in clay minerals are derived: (i) The use of defects as tracers of past radioactivity. In geological systems where the age of the clay can be constrained, ancient migrations of radioelements can be reconstructed in natural analogues of high level nuclear waste repositories. When the dose rate may be assumed constant over time, the paleodose is used to date clay populations, an approach applied to fault gouges or laterites of the Amazon basin. (ii) The influence of irradiation over physico-chemical properties of clay minerals. An environmental

  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. Protective Role of L- Carnitine and Zinc against γ-Radiation induced Cardiac and testicular Disorders in Albino Rats

    International Nuclear Information System (INIS)

    L-Carnitine is a dipeptide amino acid necessary for fat metabolism, it provides energy by transporting long-chain fatty acids to mitochondria to act as a fuel and it is considered a powerful antioxidant. In addition, zinc is an essential mineral which helps to increase the secretion of male sex hormones and raises the sperm count, so its combination with L-carnitine is useful for the fertility process. The present study aims to evaluate the potency of L-carnitine and zinc as radio- protective and curative agent pre and after exposure to γ-radiation through biochemical, histological, morphological abnormalities of sperms and DNA damage in the sperms induced by γ-irradiation by comet assay. Animals received L-carnitine (LC) and zinc (Zn) orally at the dose 9.45 mg/100 gm body wt./day for successive 20 days and then exposed to whole body gamma radiation at the dose 4 Gy (1 Gy for 4 days, day after day) on the 7th day from treatment with antioxidant. Histological examinations of heart and testis tissues showed that administration of LC and Zn have attenuated radiation induced damage and improved tissues architecture. Moreover, the observed amelioration in the tissues was accompanied by a remarkable decrease of their lipid peroxide levels (malondialdehyde (MDA)), together with an increase in glutathione peroxidase (GSHPx) and superoxide dismutase (SOD) activities. Hormonal determinations of serum testosterone (T), follicular stimulating hormone (FSH) and luteinizing hormone (LH) which carried out for fertility assessment showed that whole body γ-irradiation of rats induced significant decrease in serum testosterone while FSH and LH were significantly increased as compared with control group. On the other hand, irradiation caused significant elevation in the total number of abnormal head, and / or tail of sperms in comparison to the control rats. The comet assay showed that exposure to γ-radiation induced DNA damage of sperms (tail moment values).

  4. Clinical manifestations and radiological features may contribute to the early diagnosis of radiation-induced sarcoma after breast cancer

    International Nuclear Information System (INIS)

    Aim: To describe the clinical manifestations and radiological features contributing to the early diagnosis of radiation-induced sarcoma (RIS) after radiotherapy for breast cancer. Materials and methods: This retrospective analysis included four typical cases of RIS diagnosed at Affiliated Hospital of Academy of Military Medical Sciences between 1980 and 2013. Patient and imaging characteristics, treatment modalities, and outcomes were extracted from patients' medical records. Two pathologists reviewed all histological slides. Results: All four cases were misdiagnosed and treated for several months as cases of breast cancer relapse. CT using the bone-window setting and three-dimensional reconstructions clearly displayed bone tumours of RIS in three cases. Skin alterations were observed in all cases. At the time of RIS diagnosis, three patients were free of breast cancer. In one patient with bilateral breast cancer and lung metastasis, chemotherapy resulted in complete remission of the metastasis, but RIS progression. No RIS in this series responded to chemotherapy or endocrine therapy. Conclusions: Abnormalities appearing in the radiation field long after RT should alert clinicians to the potential development of RIS. Careful physical examination and follow-up imaging studies are necessary. The presence of skin alterations, bone tumours at CT or radiography, and poor response to anti-cancer drugs may contribute to the early detection of RIS. Biopsy should be performed immediately when RIS is suspected. - Highlights: • Abnormalities in the radiation field should alert to the development of RIS. • Skin alterations and bone tumors on images may contribute to the early detection. • Biopsy should be performed immediately when Radiation-induced sarcoma is suspected

  5. Modification of synthetic fibers by radiation-induced grafting

    International Nuclear Information System (INIS)

    The present report describes studies to modify properties of synthetic fibers by radiation-induced grafting technique. This technique was employed since it is considered to be generally applicable to the grafting of a radically polymerizable monomer onto fiber. Three synthetic fibers were used mainly in the present studies; (1) polyester fiber which is ranked as the first in the amount of production in the synthetic fibers at present and is expected to increase in its importance in the future, (2) poly (vinyl chloride) fiber which is inexpensive and fire-retardant, and (3) polyethylene fiber which is not yet used in apparel at present. In order to perform the grafting, the following two methods were studied; one is to graft monomer uniformly in the fiber preventing homopolymerization of the monomer outside of the fiber, and the other to graft monomer only on the fiber surface. Using these methods, the following experiments were carried out and fairly good results as expected were obtained. (1) In the case of polyester fiber it was intended to make this more hydrophilic and fire-retardant. (2) Concerning to poly(vinyl chloride) fiber experiments were carried out to make the fiber more hydrophilic and simultaneously more heat-resistant. (3) In the case of polyethylene fiber, target was fire-retardance and heat-resistance. (author)

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

    International Nuclear Information System (INIS)

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

  7. Processability improvement of polyolefins through radiation-induced branching

    Science.gov (United States)

    Cheng, Song; Phillips, Ed; Parks, Lewis

    2010-03-01

    Radiation-induced long-chain branching for the purpose of improving melt strength and hence the processability of polypropylene (PP) and polyethylene (PE) is reviewed. Long-chain branching without significant gel content can be created by low dose irradiation of PP or PE under different atmospheres, with or without multifunctional branching promoters. The creation of long-chain branching generally leads to improvement of melt strength, which in turn may be translated into processability improvement for specific applications in which melt strength plays an important role. In this paper, the changes of the melt flow rate and the melt strength of the irradiated polymer and the relationship between long-chain branching and melt strength are reviewed. The effects of the atmosphere and the branching promoter on long-chain branching vs. degradation are discussed. The benefits of improved melt strength on the processability, e.g., sag resistance and strain hardening, are illustrated. The implications on practical polymer processing applications such as foams and films are also discussed.

  8. Contribution to the study of radiation induced bone tissue cancer

    International Nuclear Information System (INIS)

    In this work four original observations of more or less long-delayed cancers induced by ionizing radiations are compared with 34 other cases in the literature, after which an attempt is made to establish a general and prognostic synthesis of the results; the indications to emerge are as follows: - Ionizing radiation-induced cancers are very rare, especially when compared with the extensive therapeutic use made of X-rays; - The probability of radio-cancer formation, though no figures are given in the many papers consulted, seems nevertheless to be higher in cases of benign lesion irradiation; - Induced cancers have been observed after treatments with all types of radiation, whether or not the lesion is tumoral or cancerous, whatever the patient's age at the time of irradiations; - As a general rule these neoplasms appear after a variable latency period but usually from the 6th post-radiotherapy year onwards, with a greater frequency range between 6 and 12 years; - These induced cancers are generally epitheliomas or sarcomas, the latter being noticeably more predominant than in the case of spontaneous cancers. Leukoses may also be observed

  9. Amifostine (WR2721) Drug Controls Radiation Induced Damage in Rats

    International Nuclear Information System (INIS)

    Amifostine is a pro-drug in which selectivity is largely determined by the preferential formation and uptake of its cytoprotective metabolite, WR-1065, in normal tissues as a result of differences in membrane-bound alkaline phosphatase activity. Animals were categorized into four groups as follows: control group, WR-2721-intraperitoneally injected group at a dose of 100 mg/ kg, 1.5 Gy gamma-irradiated groups for 5 days (day post day) receiving final dose up to 7.5 Gy and WR-2721 injected group at 30 minutes before exposing to every fractionated dose of gamma-irradiation. Animals were sacrificed after 7 and 16 days after the final exposure to gamma-irradiation. The results obtained showed increased levels of plasma creatinine, plasma urea, plasma total protein, alanine and aspartate aminotransferases (ALT and AST), alkaline phosphatase (ALP), total bilirubin and gamma glutamyle transferase (gamma GT) and decreased levels of Albumin/ Globulin ratio (NG) in irradiated animal group compared with the control one. Administration of Amifostine before radiation exposure has significantly improved the radiation-induced changes in all these tested parameters. It could be concluded that application of Amifostine may minimize radiation damage and attenuate the side effects resulted from radiotherapy exposure

  10. Radiation-induced tumours of the head and neck

    Energy Technology Data Exchange (ETDEWEB)

    Laan, B.F.A.M. van der; Baris, G.; Gregor, R.T.; Hilgers, F.J.M.; Balm, A.J.M. [Nederlands Kanker Inst. `Antoni van Leeuwenhoekhuis`, Amsterdam (Netherlands)

    1995-04-01

    In order to study the induction of malignancy in normal tissues due to ionizing radiation, we reviewed the files of 2500 patients with a tumour of the head and neck treated at the Netherlands Cancer Institute (Antoni van Leeuwenhoek Ziekenhuis), Amsterdam, from 1977 to 1993. We then checked whether or not these patients had been previously irradiated. Patients with a thyroid carcinoma or skin cancer were excluded from the study, since it is generally known that previous irradiation is a risk factor in these tumours. Eighteen patients were found to have a malignancy within a previous irradiated area (0.70 per cent). The mean interval between radiation and diagnosis of the head and neck tumour was 36.5 years. There were five soft tissue sarcomas, nine squamous cell carcinomas and four salivary gland tumours. Fourteen patients were operated upon whereas four received palliative treatment only. The median survival of the total group was 3.5 years. Particularly in young patients, because of the better cancer therapy and prolonged survival, one must be aware of the increased risk of radiation-induced tumours. (author).

  11. Radiation-induced defect formation in lithium sulfate crystals

    International Nuclear Information System (INIS)

    The study on the crystalline water effect on the radiation-induced processes is carried out in the Li2SO4 · H2O monocrystal samples, grown from the saturated water solution through the method of the solvent isothermal evaporation. The highly-pure source material was purified through the preliminary recrystallization. The Li2SO4 · H2O monocrystals dehydration was accomplished at 600 deg C during one hour. The powder-like samples were obtained after thermal treatment. The irradiation was conducted by the URS-55a X-ray apparatus (Cu-anticathode, U = 35 kV, I 10 mA). Measurements of the thermo-induced luminescence (TIL) curves were performed by the standard methods. The predominant peak of the recombination luminescence has the maximum in the area of 95 K. The luminescence in the area of 95 K is connected with the defects decomposition in the crystalline water subsystem. The products of the water molecules radiolysis significantly effect the recombination processes in the sulfate subsystem

  12. 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.

  13. Advance in clinical research of radiation-induced heart disease

    International Nuclear Information System (INIS)

    Radiation-induced heart disease (RIHD) is one of common late side effects derived by thoracic radiotherapy. RIHD is often subclinical and there is an extremely long clinical latent period between radiation therapy and the first clinical presentation of radiation injury, and it did not cause clinical attention for a long time. Until the 1990s, epidemiologic investigations demonstrate that thoracic cancer radiotherapy increased rates of cardiac mortality, RIHD has partly offset the survival benefit provided by adjuvant RT. Radiotherapy techniques has undergone many improvements over the last decades, these improvements decreased both the volume and dose of radiation delivered to the heart, seem to have decreased the incidence of RIHD. Nonetheless, recent studies indicate that the problem of RIHD may persist. For instance, patients with Hodgkin's Disease, lung cancer, and esophageal may still receive either a high dose of radiation to a small part of the heart or a lower dose to the whole heart in radiotherapy. Therefore, long-term cardiac followup of these patients is essential. This article briefly review the clinical presentations, influence factors, prevention and managements, diagnosis and study advances of RIHD. (authors)

  14. Radiation-induced bystander effects in vivo are sex specific

    Energy Technology Data Exchange (ETDEWEB)

    Koturbash, Igor; Kutanzi, Kristy; Hendrickson, Karl; Rodriguez-Juarez, Rocio; Kogosov, Dmitry [Department of Biological Sciences, University of Lethbridge, Alberta T1K 3M4 (Canada); Kovalchuk, Olga [Department of Biological Sciences, University of Lethbridge, Alberta T1K 3M4 (Canada)], E-mail: olga.kovalchuk@uleth.ca

    2008-07-03

    Ionizing radiation (IR) effects span beyond the area of direct exposure and can be observed in neighboring and distant naive cells and organs. This phenomenon is termed a 'bystander effect'. IR effects in directly exposed tissue in vivo are epigenetically mediated and distinct in males and females. Yet, IR-induced bystander effects have never been explored in a sex-specificity domain. We used an in vivo mouse model, whereby the bystander effects are studied in spleen of male and female animals subjected to head exposure when the rest of the body is protected by a medical-grade lead shield. We analyzed the induction of DNA damage and alterations in global DNA methylation. Molecular parameters were correlated with cellular proliferation and apoptosis levels. The changes observed in bystander organs are compared to the changes in unexposed animals and animals exposed to predicted and measured scatter doses. We have found the selective induction of DNA damage levels, global DNA methylation, cell proliferation and apoptosis in exposed and bystander spleen tissue of male and female mice. Sex differences were significantly diminished in animals subjected to a surgical removal of gonads. These data constitute the first evidence of sex differences in radiation-induced bystander effects in mouse spleen in vivo. We show the role of sex hormones in spleen bystander responses and discuss implications of the observed changes.

  15. 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)

  16. Effect of Radiation-Induced Amorphization on Smectite Dissolution

    International Nuclear Information System (INIS)

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

  17. Radiation-induced degradation of polysaccharide sodium alginate

    International Nuclear Information System (INIS)

    The radiation-induced degradation of sodium alginate by 60Co γ-rays was investigated in air at ambient temperature, and the change in their molecular weights was measured by multi-angle laser light scattering detector equipped with gel permeation chromatography (MALLS/GPC). The molecular weight of sodium alginate decreases with the increase of absorbed dose in the range of 0-60 kGy at the dose rate of 80 Gy/ min. The dispersion of molecular weight distribution of sodium alginate becomes narrow along with the absorbed dose. The weight-average molecular weight (Mw) changes from 321596.5 to 10024 when the absorbed dose increases from o kGy to 60 kGy. It is found that the degraded sodium alginate with molecular weight peak of 6000 is 83.22% of cumulative weight fraction. Anyway, the sodium alginate may have comprehensive application in the fields of agriculture, medicine and cosmetology as it can be absorbed well by biological tissue, if its weight-average molecular weight is below 10000. It is also found that new components will be contained in the products of sodium alginate degraded by irradiation. The further study dealing with the checking the biological safety and purification shall be performed. (authors)

  18. Submandibular salivary gland transfer prevents radiation-induced xerostomia

    International Nuclear Information System (INIS)

    Background: Xerostomia is a significant morbidity of radiation therapy in the management of head and neck cancers. We hypothesized that the surgical transfer of one submandibular salivary gland to submental space, outside the proposed radiation field, prior to starting radiation treatment, would prevent xerostomia. Methods: We are conducting a prospective clinical trial where the submandibular gland is transferred as part of the surgical intervention. The patients are followed clinically, with salivary flow studies and University of Washington quality of life questionnaire. Results: We report early results of 16 patients who have undergone this procedure. Seven patients have finished and 2 patients are currently undergoing radiation treatment. In 2 patients, no postoperative radiation treatment was indicated. Two patients are waiting to start radiation treatment and 2 patients refused treatment after surgery. The surgical transfer was abandoned in 1 patient. All of the transferred salivary glands were positioned outside the proposed radiation fields and were functional. The patients did not complain of any xerostomia and developed only minimal oral mucositis. There were no surgical complications. Conclusions: Surgical transfer of a submandibular salivary gland to the submental space (outside the radiation field) preserves its function and prevents the development of radiation-induced xerostomia

  19. Pilocarpine and carbacholine in treatment of radiation-induced xerostomia

    International Nuclear Information System (INIS)

    Twenty-four patients with radiation-related xerostomia were treated with oral pilocarpine solution 6 mg t.i.d., and after a 4-week drug-free period 16 of these patients were treated with carbacholine 2 mg tablets t.i.d. Basal and stimulated whole saliva flow rates were measured before commencing the drug treatment, and after 1 and 12 weeks on treatment. On a subjective linear scale both pilocarpine (p=0.01) and carbacholine (p=0.02) improved mouth moistness. Only 2 of the 8 patients with no basal or stimulated saliva flow reported some subjective benefit from the drug treatment, whereas all 8 patients with less severe xerostomia improved (p=0.007). However, the salivary flow rates measured 12 h after the last drug dose did not improve with either drug. Both drugs were generally well tolerated. It is concluded that both drugs may be useful in the treatment of radiation-induced xerostomia among patients with residual salivary function. (author). 6 refs., tabs

  20. Gamma radiation induced changes in nuclear waste glass containing Eu

    Science.gov (United States)

    Mohapatra, M.; Kadam, R. M.; Mishra, R. K.; Kaushik, C. P.; Tomar, B. S.; Godbole, S. V.

    2011-10-01

    Gamma radiation induced changes were investigated in sodium-barium borosilicate glasses containing Eu. The glass composition was similar to that of nuclear waste glasses used for vitrifying Trombay research reactor nuclear waste at Bhabha Atomic Research Centre, India. Photoluminescence (PL) and electron paramagnetic resonance (EPR) techniques were used to study the speciation of the rare earth (RE) ion in the matrix before and after gamma irradiation. Judd-Ofelt ( J- O) analyses of the emission spectra were done before and after irradiation. The spin counting technique was employed to quantify the number of defect centres formed in the glass at the highest gamma dose studied. PL data suggested the stabilisation of the trivalent RE ion in the borosilicate glass matrix both before and after irradiation. It was also observed that, the RE ion distributes itself in two different environments in the irradiated glass. From the EPR data it was observed that, boron oxygen hole centre based radicals are the predominant defect centres produced in the glass after irradiation along with small amount of E’ centres. From the spin counting studies the concentration of defect centres in the glass was calculated to be 350 ppm at 900 kGy. This indicated the fact that bulk of the glass remained unaffected after gamma irradiation up to 900 kGy.

  1. 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

    2016-04-01

    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.

  2. Radiation-induced hypoxia may perpetuate late normal tissue injury

    International Nuclear Information System (INIS)

    Purpose: The purpose of this study was to determine whether or not hypoxia develops in rat lung tissue after radiation. Methods and Materials: Fisher-344 rats were irradiated to the right hemithorax using a single dose of 28 Gy. Pulmonary function was assessed by measuring the changes in respiratory rate every 2 weeks, for 6 months after irradiation. The hypoxia marker was administered 3 h before euthanasia. The tissues were harvested at 6 weeks and 6 months after irradiation and processed for immunohistochemistry. Results: A moderate hypoxia was detected in the rat lungs at 6 weeks after irradiation, before the onset of functional or histopathologic changes. The more severe hypoxia, that developed at the later time points (6 months) after irradiation, was associated with a significant increase in macrophage activity, collagen deposition, lung fibrosis, and elevation in the respiratory rate. Immunohistochemistry studies revealed an increase in TGF-β, VEGF, and CD-31 endothelial cell marker, suggesting a hypoxia-mediated activation of the profibrinogenic and proangiogenic pathways. Conclusion: A new paradigm of radiation-induced lung injury should consider postradiation hypoxia to be an important contributing factor mediating a continuous production of a number of inflammatory and fibrogenic cytokines

  3. Radiation-induced chromosomal instability in human mammary epithelial cells

    Science.gov (United States)

    Durante, M.; Grossi, G. F.; Yang, T. C.

    1996-01-01

    Karyotypes of human cells surviving X- and alpha-irradiation have been studied. Human mammary epithelial cells of the immortal, non-tumorigenic cell line H184B5 F5-1 M/10 were irradiated and surviving clones isolated and expanded in culture. Cytogenetic analysis was performed using dedicated software with an image analyzer. We have found that both high- and low-LET radiation induced chromosomal instability in long-term cultures, but with different characteristics. Complex chromosomal rearrangements were observed after X-rays, while chromosome loss predominated after alpha-particles. Deletions were observed in both cases. In clones derived from cells exposed to alpha-particles, some cells showed extensive chromosome breaking and double minutes. Genomic instability was correlated to delayed reproductive death and neoplastic transformation. These results indicate that chromosomal instability is a radiation-quality-dependent effect which could determine late genetic effects, and should therefore be carefully considered in the evaluation of risk for space missions.

  4. Radiation induced modification of polyurethane for biomedical applications

    International Nuclear Information System (INIS)

    The polyether urethane WH8 was modified by radiation induced grafting Biocompatibility was achieved using hydrophil or hydrophil made monomers. Grafting of the monomers HEMA, GMA, GOMA and AAm onto the polyether urethane was performed by means of preswelling technique. By variation of preswelling time and irradiation dose different degrees of grafting were obtained. The grafted products were characterized by IR-Spectroscopy and the deepness of grafting was determined for the systems WH8-g-HEMA, WH8-g-GMA and WH8-g-AAm. Mechanical properties of the basis polymer and the grafted samples were measured by tension-extension experiments in the dry and waterswelled state. To the systems WH8-g-GMA and WH8-g-AAm hydrophil groups as the diol and the sulfonic group were attached by chemical reactions. The content of water of modified samples was determined and rose with increasing degree of grafting. To characterize the surface the contact angle against water (THETAsub(H2O)) and octane (THETAsub(octane)THETAsub(H2O)) was determined and therefrom the free boundary surface energy (#betta#sw) between the polymer and water. Increasing the degree of grafting adsorption of albumine rises strongly with all systems. Cell culture tests and biocompatibility tests were positive with one exception. The influence of the samples on the intravasal curdling system was determined by measuring recalcification time after incubation in human plasm. (SPI)

  5. Radiation-induced chromosome damage in astronauts' lymphocytes.

    Science.gov (United States)

    Testard, I; Ricoul, M; Hoffschir, F; Flury-Herard, A; Dutrillaux, B; Fedorenko, B; Gerasimenko, V; Sabatier, L

    1996-10-01

    The increased number of manned space missions has made it important to estimate the biological risks encountered by astronauts. As they are exposed to cosmic rays, especially ions with high linear energy transfer (LET), it is necessary to estimate the doses they receive. The most sensitive biological dosimetry used is based on the quantification of radiation-induced chromosome damage to human lymphocytes. After the space missions ANTARES (1992) and ALTAIR (1993), we performed cytogenetic analysis of blood samples from seven astronauts who had spent from 2 weeks to 6 months in space. After 2 or 3 weeks, the X-ray equivalent dose was found to be below the cytogenetic detection level of 20 mGy. After 6 months, the biological dose greatly varied among the astronauts, from 95 to 455 mGy equivalent dose. These doses are in the same range as those estimated by physical dosimetry (90 mGy absorbed dose and 180 mSv equivalent dose). Some blood cells exhibited the same cytogenetic pattern as the 'rogue cells' occasionally observed in controls, but with a higher frequency. We suggest that rogue cells might result from irradiation with high-LET particles of cosmic origin. However, the responsibility of such cells for the long-term effects of cosmic irradiation remains unknown and must be investigated. PMID:8862451

  6. 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.

  7. Autophagy promotes radiation-induced senescence but inhibits bystander effects in human breast cancer cells.

    Science.gov (United States)

    Huang, Yao-Huei; Yang, Pei-Ming; Chuah, Qiu-Yu; Lee, Yi-Jang; Hsieh, Yi-Fen; Peng, Chih-Wen; Chiu, Shu-Jun

    2014-07-01

    Ionizing radiation induces cellular senescence to suppress cancer cell proliferation. However, it also induces deleterious bystander effects in the unirradiated neighboring cells through the release of senescence-associated secretory phenotypes (SASPs) that promote tumor progression. Although autophagy has been reported to promote senescence, its role is still unclear. We previously showed that radiation induces senescence in PTTG1-depleted cancer cells. In this study, we found that autophagy was required for the radiation-induced senescence in PTTG1-depleted breast cancer cells. Inhibition of autophagy caused the cells to switch from radiation-induced senescence to apoptosis. Senescent cancer cells exerted bystander effects by promoting the invasion and migration of unirradiated cells through the release of CSF2 and the subsequently activation of the JAK2-STAT3 and AKT pathways. However, the radiation-induced bystander effects were correlated with the inhibition of endogenous autophagy in bystander cells, which also resulted from the activation of the CSF2-JAK2 pathway. The induction of autophagy by rapamycin reduced the radiation-induced bystander effects. This study reveals, for the first time, the dual role of autophagy in radiation-induced senescence and bystander effects.

  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. Transient radiation-induced absorption in the materials for a GSGG laser

    Science.gov (United States)

    Brannon, P. J.

    1993-11-01

    Materials used in the optical elements of a 1,061 m GSGG (gadolinium scandium gallium garnet) laser have been tested for transient radiation-induced absorption. The transient radiation-induced absorption in KK1, Schott S7005 and S7010, and M382 glasses have been determined for discrete wavelengths in the range 440-750 nm. Also, the transient radiation-induced absorption in 'pure' and MgO doped LiNbO3 has been measured at 1,061 nm. Mathematical expressions composed of exponentials are fitted to the data.

  10. Transient radiation-induced absorption in the materials for a GSGG laser

    Energy Technology Data Exchange (ETDEWEB)

    Brannon, P.J.

    1993-11-01

    Materials used in the optical elements of a 1,061 m GSGG (gadolinium scandium gallium garnet) laser have been tested for transient radiation-induced absorption. The transient radiation-induced absorption in KK1, Schott S7005 and S7010, and M382 glasses have been determined for discrete wavelengths in the range 440--750 nm. Also, the transient radiation-induced absorption in {open_quotes}pure{close_quotes} and MgO doped LiNbO{sub 3} has been measured at 1,061 nm. Mathematical expressions composed of exponentials are fitted to the data.

  11. Effects of helium and hydrogen on radiation-induced microstructural changes in austenitic stainless steel

    International Nuclear Information System (INIS)

    Microstructural changes in austenitic stainless steel by helium, hydrogen, and iron ion irradiation were investigated with transmission electron microscopy. Typical radiation-induced changes, such as the formation of Frank loops in the matrix and radiation-induced segregation (RIS) or depletion at grain boundaries, were observed after ion irradiation. The helium ion irradiation led to the formation of cavities both at grain boundaries and in the matrix, as well as the development of smaller Frank loops. The hydrogen ion irradiation generated stronger RIS behavior at the grain boundaries compared to irradiation with helium and iron ions. The effects of helium and hydrogen on radiation-induced microstructural changes were discussed

  12. Micronuclei: sensitivity for the detection of radiation induced damage

    International Nuclear Information System (INIS)

    The in vitro cytokinesis-block (CB) micronucleus (MN) assay for human peripheral blood has been used extensively for the assessment of chromosomal damage induced by ionizing radiation and chemicals and considered a suitable biological dosimeter for estimating in vivo whole body exposures, particularly in the case of large scale radiation accidents. One of the major drawbacks of the MN assay is its reduced sensitivity for the detection of damage induced by low doses of low LET radiation, due to the high variability among the spontaneous MN frequencies. It is suggested that age, smoking habit and sex are the main confounding factors that contribute to the observed variability. Previous work in our laboratory, shows a significant positive correlation of the spontaneous and radiation induced MN frequencies with age and smoking habit, the latter being the strongest confounder. These findings led to in vitro studies of the dose-response relationships for smoking and non smoking donors evaluated separately, using 60Co γ rays. The objectives of the present work are: 1-To increase the amount of data of the dose-response relationships, using γ rays from a 60Co source, for smoking and non smoking donors, in order to find, if applicable, a correction factor for the calibration curve that takes into account the smoking habit of the individual in the case of accidental overexposure dose assessment, particularly in the low dose range. 2-To establish general conclusions on the current state of the technique. The sample for smoking and non smoking calibration curves was enlarged in the range of 0Gy to 2Gy. The fitting of both curves, performed up to the 2Gy dose, resulted in a linear quadratic model. MN distribution among bi nucleated cells was found to be over dispersed with respect to Poisson distribution, the average ratio of variance to mean being 1.13 for non smokers and 1.17 for smokers. Each fitted calibration curve, for smoking and non smoking donors, fell within the 95

  13. Dosimetric Analysis of Radiation-induced Gastric Bleeding

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Mary, E-mail: maryfeng@umich.edu [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Normolle, Daniel [Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Pan, Charlie C. [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Dawson, Laura A. [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada); Amarnath, Sudha [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Ensminger, William D. [Department of Internal Medicine, Division of Hematology Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Lawrence, Theodore S.; Ten Haken, Randall K. [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)

    2012-09-01

    Purpose: Radiation-induced gastric bleeding has been poorly understood. In this study, we described dosimetric predictors for gastric bleeding after fractionated radiation therapy. Methods and Materials: The records of 139 sequential patients treated with 3-dimensional conformal radiation therapy (3D-CRT) for intrahepatic malignancies were reviewed. Median follow-up was 7.4 months. The parameters of a Lyman normal tissue complication probability (NTCP) model for the occurrence of {>=}grade 3 gastric bleed, adjusted for cirrhosis, were fitted to the data. The principle of maximum likelihood was used to estimate parameters for NTCP models. Results: Sixteen of 116 evaluable patients (14%) developed gastric bleeds at a median time of 4.0 months (mean, 6.5 months; range, 2.1-28.3 months) following completion of RT. The median and mean maximum doses to the stomach were 61 and 63 Gy (range, 46-86 Gy), respectively, after biocorrection of each part of the 3D dose distributions to equivalent 2-Gy daily fractions. The Lyman NTCP model with parameters adjusted for cirrhosis predicted gastric bleed. Best-fit Lyman NTCP model parameters were n=0.10 and m=0.21 and with TD{sub 50} (normal) = 56 Gy and TD{sub 50} (cirrhosis) = 22 Gy. The low n value is consistent with the importance of maximum dose; a lower TD{sub 50} value for the cirrhosis patients points out their greater sensitivity. Conclusions: This study demonstrates that the Lyman NTCP model has utility for predicting gastric bleeding and that the presence of cirrhosis greatly increases this risk. These findings should facilitate the design of future clinical trials involving high-dose upper abdominal radiation.

  14. 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.)

  15. Synthesis of EVA/MWNT nanocomposites by radiation induced crosslinking

    International Nuclear Information System (INIS)

    Full text: EVA is widely used as an insulating material for high voltage cables and in the footwear and toy industries due to its high flexibility and chemical inertness. The nano-composites of EVA with MWNT are of the special interest because incorporation of suitable amount of MWNT in EVA matrix is expected to significantly enhance EVA's thermal and mechanical properties, and open a new domain of applications. The modification of EVA by using high-energy radiation and with particulate filler has been widely practiced; however, there is not much information available on the radiation processing of EVA nanocomposites. To understand the effect of radiation and of MWNT addition on the physico-mechanical characteristics of EVA, different compositions of ethylene vinyl acetate (EVA)/multiple walled carbon nanotube (MWNT) nanocomposites were prepared by mixing in Brabender and subjected to different doses of gamma radiation. The efficiency of radiation vulcanization was analyzed by gel-content, Charlesby-Pinner parameter and crosslinking density measurements. Gamma radiation induced crosslinking was found to increase with MWNT fraction in EVA/MWNT nanocomposites (Po/qo range: 1.15-0.98). These results ruled out the possibility of a significant neutralization of single ionization spurs by MWNT addition. The polymer-filler interaction parameter determined from Kraus plot indicated good interaction between EVA and MWNTs. Storage modulus changed from 7 x 107 Pa to 1.8 x 108 Pa with incorporation of 5% (wt/wt) MWNT while density increased from 0.78 g/cc to 0.80 g/cc

  16. Curcumin Attenuates Gamma Radiation Induced Intestinal Damage in Rats

    International Nuclear Information System (INIS)

    Small Intestine exhibits numerous morphological and functional alterations during radiation exposure. Oxidative stress, a factor implicated in the intestinal injury may contribute towards some of these alterations. The present work was designed to evaluate the efficacy of curcumin, a yellow pigment of turmeric on y-radiation-induced oxidative damage in the small intestine by measuring alterations in the level of thiobarbituric acid reactive substances (TSARS), serotonin metabolism, catecholamine levels, and monoamine oxidase (MAO) activity in parallel to changes in the architecture of intestinal tissues. In addition, monoamine level, MAO activity and TSARS level were determined in the serum. Curcumin was supplemented orally via gavages, to rats at a dose of (45 mg/ Kg body wt/ day) for 2 weeks pre-irradiation and the last supplementation was 30 min pre exposure to 6.5 Gy gamma radiations (applied as one shot dose). Animals were sacrificed on the 7th day after irradiation. The results demonstrated that, whole body exposure of rats to ionizing radiation has induced oxidative damage in small intestine obvious by significant increases of TSARS content, MAO activity and 5-hydroxy indole acetic acid (5-HIAA) and by significant decreases of serotonin (5-HT), dopamine (DA), norepinephrine (NE) and epinephrine (EPI) levels. In parallel histopathological studies of the small intestine of irradiated rats through light microscopic showed significant decrease in the number of villi, villus height, mixed sub mucosa layer with more fibres and fibroblasts. Intestinal damage was in parallel to significant alterations of serum MAO activity, TBARS, 5-HT, DA, NE and EPI levels. Administration of curcumin before irradiation has significantly improved the levels of monoamines in small intestine and serum of irradiated rats, which was associated with significant amelioration in MAO activity and TBARS contents

  17. Analysis of radiation-induced genome alterations in Vigna unguiculata

    Directory of Open Access Journals (Sweden)

    van der Vyver C

    2011-09-01

    Full Text Available Christell van der Vyver1, B Juan Vorster2, Karl J Kunert3, Christopher A Cullis41Institute for Plant Biotechnology, Department of Genetics, University of Stellenbosch, Stellenbosch, South Africa; 2Department of Plant Production and Soil Science, and 3Department of Plant Science, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa; 4Case Western Reserve University, Department of Biology, Cleveland, OH, USAAbstract: Seeds from an inbred Vigna unguiculata (cowpea cultivar were gamma-irradiated with a dose of 180 Gy in order to identify and characterize possible mutations. Three techniques, ie, random amplified polymorphic DNA, microsatellites, and representational difference analysis, were used to characterize possible DNA variation among the mutants and nonirradiated control plants both immediately after irradiation and in subsequent generations. A large portion of putative radiation-induced genome changes had significant similarities to chloroplast sequences. The frequency of mutation at three of these isolated polymorphic regions with chloroplast similarity was further determined by polymerase chain reaction screening using a large number of individual parental, M1, and M2 plants. Analysis of these sequences indicated that the rate at which various regions of the genome is mutated in irradiation experiments differs significantly and also that mutations have variable “repair” rates. Furthermore, regions of the nuclear DNA derived from the chloroplast genome are highly susceptible to modification by radiation treatment. Overall, data have provided detailed information on the effects of gamma irradiation on the cowpea genome and about the ability of the plant to repair these genome changes in subsequent plant generations.Keywords: mutation breeding, gamma radiation, genetic mutations, cowpea, representational difference analysis

  18. Radiation induced degradation of PAHs in water solution

    International Nuclear Information System (INIS)

    By combustion of coal in the caloric electrical plants, steel industry etc. in addition to NOx, SO2/SO3 (acid rain precursors) a number of rather toxic polycyclic aromatic hydrocarbons, such as diphenyloxide, fluorene, fluoranthene, naphthalene, anthracene, benzo(a)pyrene etc. are formed. They are emitted with the flue gases into the atmosphere and by rain and snow they can be brought to the ground water. These substances are carcinogenic, even in very small concentration, namely from 3 x 10-2 (diphenyloxide) to 1 x 10-6 (benz(a)pyrene) mg/m3 flue gas. Moreover, these pollutants are strongly involved in the ozone depletion of the atmosphere. The present dissertation deals with the degradation of PAHs by ozonolysis, γ-ray treatment and combined γ-ray-ozone treatment in light alkaline aqueous solution. In order to establish the optimal conditions for radiation-induced degradation, studies on individual representative compounds of this group were carried out under various conditions - in aqueous, aerated media (formation of peroxyl radicals) as well as in such saturated with N2O (conversion of eaq- into OH). Diphenyloxide (DPO), Fluorene (FLU) and Fluoranthene (FA) were taken as models for this group of compounds. The yields of the major degradation products were determined by means of internal standards using HPLC. Fast kinetic measurements were carried out by pulsradiolysis. Summing up it can be stated that DPO, FLU and FA as well as the resulting toxic products can be completely decomposed. The best pathway is a combined treatment of radiation and ozone, followed by a radiation processing in the presence of air. The involved reaction mechanisms in the step-by-step degradation are rather complicated. Based on the obtained results are postulated probable reaction mechanisms for illustration and for better understanding of the manifold processes. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Sakurai, Tomoyasu; Nishio, Masamichi; Kagami, Yoshikazu; Murakami, Yoshitaka; Narimatsu, Naoto; Kanemoto, Toshitaka (National Hospital of Sapporo (Japan))

    1984-09-01

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

  20. 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...

  1. Radiation-Induced Dislocation and Growth Behavior of Zirconium and Zirconium Alloys - A Review

    International Nuclear Information System (INIS)

    Zirconium and zirconium alloys are widely used as nuclear reactor core materials such as fuel cladding and guide tubes because they have excellent corrosion- and radiation-resistant properties. In the reactor core, zirconium alloys are subjected to high-energy neutron fluence, causing radiation-induced dislocation and growth. To discern a possible correlation between radiation-induced dislocation and growth, characteristics of dislocation and growth in zirconium and its alloys are examined. The radiation-induced dislocation including and dislocation loops is reviewed in various temperature and fluence ranges, and their growth behavior is examined in the same way. To further a fundamental understanding, radiation-induced growth prediction models are briefly reviewed. This research will assist in the design of zirconium based components as well as the safety analysis of various reactor conditions, in both research and commercial reactors

  2. Radiation induced structural and functional modification of haemoglobin.

    Science.gov (United States)

    Suchomlinov, B F; Savich, A V; Starikovich, L S; Dudok, E P

    1985-06-01

    An abnormality in the primary structure of dog haemoglobin was observed 1-20 days after their whole body irradiation with 190 keV X-rays (4.0 Gy). It consisted in a substitution of tryptophane residue in position 15 of the beta-chain for serine. The percentage of abnormal beta-chains in different time intervals after irradiation was determined. The structural changes have functional impact: an increasing haemoglobin affinity to oxygen. This could be explained on the basis of changes in the tertiary structure of haemoglobin, which may result from the substitution Trp 15----Ser15 in the beta-chain which may influence the haeme ability to bind oxygen. PMID:3896922

  3. Irreversible photo- and radiation-induced effects in amorphous films of arsenic trisulfide

    International Nuclear Information System (INIS)

    It is found that irreversible photo- and radiation-induced effects in virgin As2S3 thin films are accompined by the similar changes of their optical properties. The process of homopolar chemical bond breaking in the thin layer alongside with the creation of the differently charged diamagnetic defects associated with the non-equilibrium breaking of chemical bonds is proper in radiation induced effects, only

  4. Curcumin Attenuates Radiation-Induced Inflammation and Fibrosis in Rat Lungs

    OpenAIRE

    Cho, Yu Ji; Yi, Chin Ok; Jeon, Byeong Tak; Jeong, Yi Yeong; Kang, Gi Mun; Lee, Jung Eun; Roh, Gu Seob; Lee, Jong Deog

    2013-01-01

    A beneficial radioprotective agent has been used to treat the radiation-induced lung injury. This study was performed to investigate whether curcumin, which is known to have anti-inflammatory and antioxidant properties, could ameliorate radiation-induced pulmonary inflammation and fibrosis in irradiated lungs. Rats were given daily doses of intragastric curcumin (200 mg/kg) prior to a single irradiation and for 8 weeks after radiation. Histopathologic findings demonstrated that macrophage acc...

  5. Naringin abrogated radiation induced oxidative stress through modulation of redox regulated cellular signaling system

    International Nuclear Information System (INIS)

    Ionizing radiation is widely used as major diagnostic and therapeutic applications. However, the deleterious effects of ionizing radiation are due to generation of reactive oxygen species. The amounts of ionizing radiation that can be given to treat malignant tumours are often limited by toxicity in the surrounding normal tissues and organs. The aim of this study was to investigate the role of Naringin (NG), a natural flavonoid, present in many plant parts against radiation induced oxidative stress with an evidence based exploration of the mechanism involved. Isolated murine splenocyte were irradiated with γ radiation (6 Gy) along with/without different concentrations of NG (50 and 100 μM). Biochemical, immunoblot, flow cytometry and immunofluorescence study was subject to be performed to observe its molecular mechanisms of action. Pretreatment with NG significantly prevented the radiation induced intracellular ROS generation, therefore prevented cellular TBARS formation and development of cellular nitrite. NG showed the significant reduction in nuclear DNA damage with respect to irradiated splenocyte through inhibition of DNA-PKcs and p-γH2AX. It recovered radiation induced reduced cell viability through modulation of redox regulated cell signaling system. It resulted in significant inhibition of radiation induced G1/S phase cell cycle arrest mediated by modulation of p53 dependent p21/WAF1 expression followed by Cyclin E and CDK2 expression. NG was involved in blocking radiation induced p38 function; reversed radiation mediated differential stress response through inhibition of NF-κB pathway. It prevented p-IKKα/β, p-IκBα, p-p65, COX2 expression. It also reversed the radiation induced p38/NF-κB guided inflammatory development. Thus it down regulated radiation induced CRP, MCP-1, and iNOS2 gene expression. This novel role of naringin provides a basis for therapeutic applications in future against radiation induced molecular and cellular functional

  6. 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

  7. Radiation-Induced Topological Disorder in Irradiated Network Structures

    International Nuclear Information System (INIS)

    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

  8. Single-Dose Radiation-Induced Oral Mucositis Mouse Model

    Science.gov (United States)

    Maria, Osama Muhammad; Syme, Alasdair; Eliopoulos, Nicoletta; Muanza, Thierry

    2016-01-01

    The generation of a self-resolved radiation-induced oral mucositis (RIOM) mouse model using the highest possibly tolerable single ionizing radiation (RT) dose was needed in order to study RIOM management solutions. We used 10-week-old male BALB/c mice with average weight of 23 g for model production. Mice were treated with an orthovoltage X-ray irradiator to induce the RIOM ulceration at the intermolar eminence of the animal tongue. General anesthesia was injected intraperitoneally for proper animal immobilization during the procedure. Ten days after irradiation, a single RT dose of 10, 15, 18, 20, and 25 Gy generated a RIOM ulcer at the intermolar eminence (posterior upper tongue surface) with mean ulcer floor (posterior epithelium) heights of 190, 150, 25, 10, and 10 μm, respectively, compared to 200 μm in non-irradiated animals. The mean RIOM ulcer size % of the total epithelialized upper surface of the animal tongue was RT dose dependent. At day 10, the ulcer size % was 2, 5, 27, and 31% for 15, 18, 20, and 25 Gy RT, respectively. The mean relative surface area of the total epithelialized upper surface of the tongue was RT dose dependent, since it was significantly decreased to 97, 95, 88, and 38% with 15, 18, 20, and 25 Gy doses, respectively, at day 10 after RT. Subcutaneous injection of 1 mL of 0.9% saline/6 h for 24 h yielded a 100% survival only with 18 Gy self-resolved RIOM, which had 5.6 ± 0.3 days ulcer duration. In conclusion, we have generated a 100% survival self-resolved single-dose RIOM male mouse model with long enough duration for application in RIOM management research. Oral mucositis ulceration was radiation dose dependent. Sufficient hydration of animals after radiation exposure significantly improved their survival. PMID:27446800

  9. 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.

  10. Molecular biology methods in assessing radiation-induced hereditary risks in humans

    Energy Technology Data Exchange (ETDEWEB)

    Kiuru, A. [University of Helsinki, Department of Biosciences, Division of Genetics, Helsinki (Finland)

    2004-12-01

    Effort to predict the genetic consequences for humans of exposure to ionising radiation has been one of the most important issues of human genetics over the past 60 years. To date, there has been little experimental knowledge on the genetic risks of human exposure to ionising radiation. Radiation-induced deleterious hereditary effects have not been detected in human populations - not even among the offspring of atomic bomb survivors in Hiroshima and Nagasaki. This does not mean deleterious hereditary effects do not exist in humans, but rather that they are small and/or difficult to detect because the normal incidence of inherited abnormalities is quite high in the human population. Thus, assessment of radiation-induced hereditary risks in humans has been based on the common knowledge of human heredity and on animal experiments. However, recent data have suggested that hyper-variable tandem repeat minisatellite loci provide a useful and sensitive experimental approach for monitoring radiation-induced germline mutations in humans. In order to investigate the feasibility of the minisatellite mutation screening system in assessing radiation-induced hereditary risks in humans, we examined the amount of hereditary minisatellite mutations among the offspring of Estonian Chernobyl cleanup workers. The men studied received a median radiation dose of 109 mSv while working on the cleanup activities after the Chernobyl accident. We compared the minisatellite mutation rates of 155 children born to 147 Estonian Chernobyl cleanup workers after the accident to those of their 148 siblings born prior to it. In addition, 44 Estonian families, where the father had not been exposed to radiation, composed an additional control group. In all of these families, the paternity of the children was ascertained by using 5 minisatellite loci (APOB, HRAS, MCOB19, MCT118, and YNZ-22) in PCR-based analyses. Other 8 minisatellite loci (B6.7, CEB1, CEB15, CEB25, CEB36, MS1, MS31, and MS32) were used

  11. Dose-Related Effects of Acetylsalicylic acid (ASA) on Gamma Radiation-Induced Teratogenicity in Pregnant Albino Rats

    International Nuclear Information System (INIS)

    Reviews of acetylsalicylic acid (ASA), a widely used nonsteroidal anti- inflammatory drug, has consistently suggested a possible association between prenatal ASA ingestion and adverse effects in the pregnant mothers and their developing fetuses. The objective of the current study was to comprehensively define the effect of relatively low and high doses of ASA (25 mg/kg body wt. and 200 mg/kg body wt. respectively) on gestating rats and their possible impact on the irradiated ones. Therefore 36 pregnant rats were randomly divided into 6 equal groups. Three rat groups were daily orally gavaged from the 7th to the 18th gestational days with: distilled water (Group 1), 25 mg/kg body wt. ASA (Group 2) and 200 mg/kg body wt. ASA (Group 3). The other three groups similarly received the same previous treatments besides 2 Gy whole body gamma irradiation of each, to serve as: Group 4 (distilled water + irradiation), Group 5 (25 mg/kg body wt. ASA + irradiation) and Group 6 (200 mg/kg body wt. ASA + irradiation). All rat groups were sacrificed on the 20th day of pregnancy and the uterine contents were examined. The lower ASA dose (25 mg/kg body wt.) treated group (Group 2) displayed healthy mothers and fetuses whereas that of the higher dose (200 mg/kg body wt.) (Group 3) despite not showing significant maternal or fetal mortalities, yet the intrauterine contents presented fetal developmental disorders including stunted growth and resorption together with some head and limb anomalies including plagiocephaly, marked acampsia and acrocontracture. Meanwhile, results have unexpectedly shown a radioprotective role of the lower ASA dose (25 mg/kg. body wt.) (Group 5) to pregnant rats and their fetuses as inspected by its efficacy in retrieving the radiation induced maternal weight loss together with its noticeable ameliorating effects on the intrauterine lethality of the affected fetuses and their externally detected abnormalities in addition toits effectiveness in retaining some

  12. The Possible Protective Role of Foeniculum vulgare Mill. Against Radiation-Induced Certain Biochemical Changes in Albino Rats

    International Nuclear Information System (INIS)

    This study was conducted to evaluate the modulating efficacy of prolonged oral administration of Foeniculum vulgare Mill. essential oil (FEO) against gamma irradiation-induced biochemical changes in male rats. Essential oil of Foeniculum vulgare Mill. was orally administrated at dose level of 250 mg/kg body wt/day for 21 days before irradiation and 7 days post exposure (6.5 Gy single dose). Rats exposed to ionizing radiation exhibited a potential elevation of serum aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities, bilirubin, urea and creatinine levels, lipid abnormalities, and an increase in tissue lipid peroxidation (LPO) and metallothioneins (MTs). On the other hand, noticeable drop in liver and kidney glutathione content and serum total protein, albumin and testosterone levels were recorded. Tissue organs displayed some changes in trace element concentrations, which may be due to the radiation ability to induce oxidative stress. The data obtained from rats treated with fennel oil before and after whole body gamma irradiation revealed significant modulation in the biochemical tested parameters and profound improvement in the activity of antioxidant status, glutathione and metallothioneins. The treatment of irradiated rats with fennel oil also appeared to be effective in minimizing the radiation-induced increase in lipid peroxidation as well as changes in essential trace elements in some tissue organs. In addition to its containing many chemical antioxidant constituents such as polyphenols, fennel was found to contain detectable concentrations of essential trace elements (Zn, Cu, Fe, Se, Mg, Mn and Ca) which may be involved in multiple biological processes as constituents of enzymes system including superoxide dismutase (Cu, Zn, Mn, SODs), oxide reductase, glutathione (GSP, GSH, GST), metallothionein MTs, etc. Overall, it could be concluded that Foeniculum vulgare Mill. essential oil exerts beneficial protective role against radiation-induced

  13. Image-based modeling of radiation-induced foci

    Science.gov (United States)

    Costes, Sylvain; Cucinotta, Francis A.; Ponomarev, Artem; Barcellos-Hoff, Mary Helen; Chen, James; Chou, William; Gascard, Philippe

    Several proteins involved in the response to DNA double strand breaks (DSB) form microscopically visible nuclear domains, or foci, after exposure to ionizing radiation. Radiation-induced foci (RIF) are believed to be located where DNA damage occurs. To test this assumption, we used Monte Carlo simulations to predict the spatial distribution of DSB in human nuclei exposed to high or low-LET radiation. We then compared these predictions to the distribution patterns of three DNA damage sensing proteins, i.e. 53BP1, phosphorylated ATM and γH2AX in human mammary epithelial. The probability to induce DSB can be derived from DNA fragment data measured experimentally by pulsed-field gel electrophoresis. We first used this probability in Monte Carlo simulations to predict DSB locations in synthetic nuclei geometrically described by a complete set of human chromosomes, taking into account microscope optics from real experiments. Simulations showed a very good agreement for high-LET, predicting 0.7 foci/µm along the path of a 1 GeV/amu Fe particle against measurement of 0.69 to 0.82 foci/µm for various RIF 5 min following exposure (LET 150 keV/µm). On the other hand, discrepancies were shown in foci frequency for low-LET, with measurements 20One drawback using a theoretical model for the nucleus is that it assumes a simplistic and static pattern for DNA densities. However DNA damage pattern is highly correlated to DNA density pattern (i.e. the more DNA, the more likely to have a break). Therefore, we generalized our Monte Carlo approach to real microscope images, assuming pixel intensity of DAPI in the nucleus was directly proportional to the amount of DNA in that pixel. With such approach we could predict DNA damage pattern in real images on a per nucleus basis. Since energy is randomly deposited along high-LET particle paths, RIF along these paths should also be randomly distributed. As expected, simulations produced DNA-weighted random (Poisson) distributions. In

  14. Radiation-induced oral mucositis in mice: strain differences.

    Science.gov (United States)

    Dörr, W; Spekl, K; Martin, M

    2002-08-01

    The present study was initiated to investigate strain differences in oral mucosal radiosensitivity in mice with regard to induction of clinically manifest ulceration. Mouse ventral tongue epithelium was used as an established animal model for radiobiological studies of radiation-induced mucositis. Mice from two different strains, C3H/Neu (n = 40) from the Dresden colony, and B6D2F1 (n = 50) from the Harlan/Winkelmann UK colony were subjected to irradiation of tongue mucosa. Graded single doses were applied to a 3 x 3 mm2 test field in the centre of the lower tongue with 25 kV X-rays in order to generate full dose-effect curves for acute mucosal ulceration, as a clinically relevant reaction. For both groups, dose-effect curves were computed by logit analysis; comparison of the curves was by maximum-likelihood chi2 test. In addition, the time course of ulceration, i.e. latent time and individual ulcer duration, was analysed. In both mouse strains, a well-defined dose effect was observed. The ED50 values, i.e. the doses at which ulceration is expected in 50% of the animals irradiated, and their standard deviation sigma, calculated by logit analysis, can be used to describe radiosensitivity. The ED50 was 11.0 +/- 3.4 Gy (95% confidence interval (7.2; 15.4), P for dose dependence: 0.014) and 13.4 +/- 3.6 Gy (95% confidence interval (10.6; 16.1), P for dose dependence: 0.0002) in C3H and BDF1 mice, respectively. Hence, oral mucosa in BDF1 mice was found to be marginally more radioresistant (P = 0.1). The latent time to ulceration, i.e. the time between irradiation and first diagnosis of ulcer, was 11.6 +/- 0.2 days (mean +/- SEM, n = 18) in C3H mice and 5.6 +/- 0.1 days (n = 27) in BDF1 mice (P = 0.0001). Both were independent of dose (PC3H = 0.94, PBDF1 = 0.33) and hence were calculated for all responding animals of the respective strain. Ulcer duration was 2.8 +/- 0.2 days and 2.4 +/- 0.1 days in C3H and B6 mice, respectively, and was also independent of dose (PC3H = 0

  15. 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.

  16. 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.

  17. Radiation-Induced Liver Damage: Correlation of Histopathology with Hepatobiliary Magnetic Resonance Imaging, a Feasibility Study

    International Nuclear Information System (INIS)

    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

  18. The effects of polaprezinc on radiation-induced taste alterations

    International Nuclear Information System (INIS)

    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)

  19. 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)

  20. Hormonal relations of radiation-induced tumors of Arabidopsis thaliana

    International Nuclear Information System (INIS)

    When gamma-irradiated Arabidopsis seed was germinated, tumors appeared on hypocotyls and apical meristems of the resulting plants. Several tumors have been cultured on hormone free medium for over two years since excision from the plants. The tumor lines display a range of phenotypes suggestive of abnormal hormone balance. To determine whether hormone overproduction or hypersensitivity is involved in tumorigenesis, we are measuring hormone levels in the tumor lines and characterizing their response to exogenously supplied growth regulators. Growth of two tumor lines is stimulated by either NAA or BAP, one is stimulated by NAA only, two by BAP only, and one is stimulated by neither. Growth of all lines tested thus far is inhibited by gibberellic acid, ethephon and ACC. The tumor lines appear more sensitive to ACC than normal callus tissue. Most tumors studied to date appear unlikely to have arisen due to increased hormone sensitivity. Experiments are in progress to determine auxin and cytokinin levels in the tumor lines

  1. Establishment of an animal model for radiation-induced vomiting in rats using pica

    International Nuclear Information System (INIS)

    We investigated whether radiation-induced pica, a behavior characterized by the eating of a non-food substance, such as kaolin, can be used as an index of radiation-induced vomiting in rats. Since there was an individual difference in the susceptibility to pica, we selected rats that actually ate kaolin following X-ray irradiation, and used them for the experiment. The total-body irradiation (TBI) increased kaolin consumption in a dose-dependent manner (sham, 0.05±0.03 (SEM) g; 2 Gy, 0.38±0.11 g; 4 Gy, 1.54±0.28 g; 8 Gy, 3.55±0.67 g), and the increased kaolin consumption after 4 Gy of TBI was inhibited by a pretreatment with the serotonin 5-HT3 receptor antagonist ondansetron (2 mg/kg, i.p.) (saline, 1.49±0.33 g; ondansetron, 0.75±0.11 g). Furthermore, 4 Gy of abdominal irradiation was more effective to induce pica than that of head irradiation (abdomen: 0.37±0.05 g, head: 0.06±0.01 g). These findings suggested that peripheral serotonergic pathway is predominantly involved in the development of radiation-induced pica in rats and that the radiation-induced pica could be useful as a behavioral index for the severity of radiation-induced vomiting in rats. (author)

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

    Science.gov (United States)

    Yoo, Hyun; Kang, Jeong Wook; Lee, Dong Won; Oh, Sang Ho; Lee, Yun-Sil; Lee, Eun-Jung; Cho, Jaeho

    2015-05-01

    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. PMID:25797627

  3. Strain difference in jejunal crypt cell susceptibility to radiation-induced apoptosis.

    Science.gov (United States)

    Weil, M M; Stephens, L C; Amos, C I; Ruifrok, A C; Mason, K A

    1996-11-01

    Levels of radiation-induced jejunal crypt cell apoptosis were compared in C57BL/6J, C3Hf/Kam and C3H/HeJ mice. Apoptosis levels were consistently lower in the C3H strains than in C57BL/6J. Although other explanations are possible, the strain difference is most likely to have a genetic basis, and in fact a preliminary analysis of the F2 progeny of C3H/HeJ and C57BL/6J mice indicates that more than one gene is involved. Both C3H strains also had lower levels of radiation-induced thymocyte apoptosis than C57BL/6J mice. Jejunal crypt cell apoptosis levels did not co-segregate with thymocyte apoptosis levels in the F2 progeny of C57BL/6J and C3H/HeJ mice. These results imply that the genes responsible for the difference in radiation-induced thymocyte apoptosis levels between these two strains are not the same as those responsible for the strain difference in radiation-induced jejunal crypt cell apoptosis levels. The experiments reported here identify strain-specific differences in levels of radiation-induced crypt cell apoptosis and are a first step towards identifying genetic polymorphisms that influence sensitivity of the small intestine to damage from ionizing radiation.

  4. 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.

  5. Search for the lowest irradiation dose from literatures on radiation-induced breast cancer

    International Nuclear Information System (INIS)

    A survey of past case reports concerning radiation-induced breast cancer was carried out in order to find the lowest irradiation dose. The search of literature published since 1951 revealed 10 cases of radiation-induced breast cancer. Only 5 cases had precise descriptions of the irradiation dose. The lowest irradiation dose was estimated at 1470 rads in the case of external X-ray irradiation for tuberous angioma. All of cases of radiation-induced breast cancer had received radiation for the treatment of nonmalignant tumors, such as pulmonary tuberculosis, mastitis, and tuberous angioma. There also were three statistical studies. The first concerned atomic bomb survivors, the second, pulmoanry tuberculous patients subjected to frequent fluoroscopies, and the third, patients of acute post partum mastitis. These statistical studies had revealed a significant increase in the incidence of breast cancer in the irradiated group, but there was little information about the lowest irradiation dose. It was noticed that radiation-induced breast cancer was more numerous in the upper inner quadrant of the breast. Most histopathological findings of radiation-induced breast cancer involved duct cell carcinoma. The latent period was about 15 years. (Evans, J.)

  6. Chinese prescription Shenlingbaizhu extract prevents radiation-induced small intestinal injury in mice

    International Nuclear Information System (INIS)

    Objective: to investigate the therapeutic effect of traditional Chinese prescription Shenlingbaizhu Extract on radiation-induced intestinal injury in mice. Methods: Proliferation improvement of irradiated intestinal epithelial cells (IEC-6) was tested by MTT assay in vitro. The preventive effect of the prescription was also tested in vivo. Mice were treated with Shenlingbaizhu by intragastric administration immediately after receiving local irradiation to the abdomen at a dose of 10 Gy (60Co γ-ray). The body mass, diarrhea and survival were recorded. The pathological changes in the jejunum of mice were stained by HE and observed. Results: Shenlingbaizhu Extract could significantly promote the proliferation of irradiated intestinal epithelial cells in vitro. Shenlingbaizhu Extract treatment reduced the diarrhea of irradiated mice, improved the intestinal structural recovery and increased the mice survival. Conclusion: Traditional Chinese prescription Shenlingbaizhu Extract shows significant protective effect on radiation-induced intestinal injury in mice, providing data for clinical treatment of radiation-induced intestinal injury. (authors)

  7. Changes in peroxidases associated with radiation-induced sprout inhibition in garlic (Allium sativum L. )

    Energy Technology Data Exchange (ETDEWEB)

    Croci, C.A.; Curvetto, N.R.; Orioli, G.A. (Universidad Nacional del Sur, Bahia Blanca (Argentina)); Arguello, J.A. (Universidad Nacional de Cordoba (Argentina). Dept. de Biologia Aplicada)

    1991-02-01

    The effects of an acute dose of {gamma}-rays (10 Gy) to post-dormant garlic cloves on inner sprout growth and changes in peroxidases and soluble proteins were evaluated up to 100 days of storage in darkness at 19+-1{sup 0}C and 42+-2% relative humidity. Radiation-induced inhibition of sprout growth became evident after 25 days of treatment and was synchronous with a marked increase in peroxidase activity. Thin-layer isoelectric focusing revealed that radiation induced an increase in the number of anodic peroxidase isoenzymes at 100 days, suggesting modifications in the vascularization process. Neither the soluble protein content nor the protein pattern were affected by irradiation. These results are discussed in terms of a possible mediating effect of peroxidase on radiation-induced sprout inhibition in garlic. (author).

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

    International Nuclear Information System (INIS)

    Effect of radiation-induced physical ageing is investigated by differential scanning calorimetry method in AsxSe100-x (10 ≤ x ≤ 42) and AsxS100-x (30 ≤ x ≤ 42) glasses. Obtained results are compared with conventional physical ageing at normal conditions. Significant radiation-induced physical ageing is recorded for glassy AsxS100-x within 30 ≤ x xSe100-x glasses from the same compositional interval do not show any measurable changes in DSC curves after γ-irradiation. Observed difference in radiation-induced physical ageing in arsenic-sulfide/selenide glasses is explained by a greater lifetime of γ-induced excitations within sulfur-based network in comparison with selenium-based one.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-11-15

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

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

    International Nuclear Information System (INIS)

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

  11. Changes in peroxidases associated with radiation-induced sprout inhibition in garlic (Allium sativum L.)

    International Nuclear Information System (INIS)

    The effects of an acute dose of γ-rays (10 Gy) to post-dormant garlic cloves on inner sprout growth and changes in peroxidases and soluble proteins were evaluated up to 100 days of storage in darkness at 19±10C and 42±2% relative humidity. Radiation-induced inhibition of sprout growth became evident after 25 days of treatment and was synchronous with a marked increase in peroxidase activity. Thin-layer isoelectric focusing revealed that radiation induced an increase in the number of anodic peroxidase isoenzymes at 100 days, suggesting modifications in the vascularization process. Neither the soluble protein content nor the protein pattern were affected by irradiation. These results are discussed in terms of a possible mediating effect of peroxidase on radiation-induced sprout inhibition in garlic. (author)

  12. Quantitative analysis of radiation-induced changes in sperm morphology

    International Nuclear Information System (INIS)

    When developing spermatogenic cells are exposed to radiation, chemical carcinogens or mutagens, the transformation in the morphology of the mature sperm can be used to determine the severity of the exposure. In this study five groups of mice with three mice per group received testicular doses of X irradiation at dosage levels ranging from 0 rad to 120 rad. A random sample of 100 mature sperm per mouse was analyzed five weeks later for the quantitative morphologic transformation as a function of dosage level. The cells were stained with gallocyanin chrome alum (GCA) so that only the DNA in the sperm head was visible. The ACUity quantitative microscopy system at Lawrence Livermore National Laboratory was used to scan the sperm at a sampling density of 16 points per linear micrometer and with 256 brightness levels per point. The contour of each cell was extracted using conventional thresholding techniques on the high-contrast images. For each contour a variety of shape features was then computed to characterize the morphology of that cell. Using the control group and the distribution of their shape features to establish the variability of a normal sperm population, the 95% limits on normal morphology were established. Using only four shape features, a doubling dose of approximately 39 rad was determined. That is, at 39 rad exposure the percentage of abnormal cells was twice that occurring in the control population. This compared to a doubling dose of approximately 70 rad obtained from a concurrent visual procedure

  13. Radiation-induced amorphization of rare-earth titanate pyrochlores

    Science.gov (United States)

    Lian, Jie; Chen, Jian; Wang, L. M.; Ewing, Rodney C.; Farmer, J. Matt; Boatner, Lynn A.; Helean, K. B.

    2003-10-01

    Single crystals of the entire series of A2Ti2O7 (A=Sm to Lu, and Y) pyrochlore compounds were irradiated by 1-MeV Kr+ ions at temperatures from 293 to 1073 K, and the microstructure evolution, as a function of increasing radiation fluence, was characterized using in situ transmission electron microscopy (TEM). The critical amorphization temperature, Tc, generally increases from ˜480 to ˜1120 K with increasing A-site cation size (e.g., 0.977 Å for Lu3+ to 1.079 Å for Sm3+). An abnormally high susceptibility to ion beam damage was found for Gd2Ti2O7 (with the highest Tc of ˜1120 K). Factors influencing the response of titanate pyrochlores to ion irradiation-induced amorphization are discussed in terms of cation radius ratio, defect formation, and the tendency to undergo an order-disorder transition to the defect-fluorite structure. The resistance of the pyrochlore structure to ion beam-induced amorphization is not only affected by the relative sizes of the A- and B-site cations, but also the cation electronic configuration and the structural disorder. Pyrochlore compositions that have larger structural deviations from the ideal fluorite structure, as evidenced by the smaller 48f oxygen positional parameter, x, are more sensitive to ion beam-induced amorphization.

  14. Predictive Factors of Radiation-Induced Lung Toxicity in Lung Cancer Patients: A Retrospective Study

    Directory of Open Access Journals (Sweden)

    Maher Soliman

    2016-07-01

    Full Text Available Background: Radiation-induced lung toxicity is an important dose-limiting toxicity in lung cancer radiotherapy, for which there are no generally accepted predictive factors. This study seeks to identify risk factors associated with the development of severe radiation-induced lung toxicity using clinical and dosimetric parameters. Methods: We reviewed the medical records of 54 patients with histologically proven stage III non-small cell lung cancer treated with three dimensional-conformal radiotherapy at Alexandria Main University Hospital between January 2008 and December 2011. The original treatment plans for those patients were restored and imported to a treatment planning system. Lung dose–volume histograms and various dosimetric parameters were calculated. Univariate and multivariate logistic regression analyses were performed. Results: The following grades of radiation-induced lung toxicity were observed in patients - grade 0: 17 (31.5%, grade 1: 5 (9.3%, grade 2: 13 (24.1%, grade 3: 15 (27.8%, and grade 5: 4 (7.4%. A total of 19 (35.2% patients developed grade ≥3 and were considered to have an event. Univariate analysis showed that age, presence of chronic obstructive pulmonary disease and location of the primary tumor had significant associations with severe radiation-induced lung toxicity. Other dosimetric variables such as tumor side, histology, forced expiratory volume in 1 s, smoking, and gender showed no significant correlations with severe radiation-induced lung toxicity. Multivariate analysis showed that the presence of chronic obstructive pulmonary disease (P=0.001 and location of the primary tumor (P=0.010 were the only predictive factors for severe radiation-induced lung toxicity. Conclusion: This study demonstrates that patients with chronic obstructive pulmonary disease and lower lung lobe tumors have a high risk of severe radiationinduced lung toxicity when treated with combined chemoradiotherapy. These easily obtained

  15. Gamma radiation-induced blue shift of resonance peaks of Bragg gratings in pure silica fibres

    Science.gov (United States)

    Faustov, A. V.; Gusarov, A. I.; Mégret, P.; Wuilpart, M.; Kinet, D.; Zhukov, A. V.; Novikov, S. G.; Svetukhin, V. V.; Fotiadi, A. A.

    2016-02-01

    We report the first observation of a significant gamma radiation-induced blue shift of the reflection/transmission peak of fibre Bragg gratings inscribed into pure-silica core fibres via multiphoton absorption of femtosecond pulses. At a total dose of ~100 kGy, the shift is ~20 pm. The observed effect is attributable to the ionising radiation-induced decrease in the density of the silica glass when the rate of colour centre formation is slow. We present results of experimental measurements that provide the key parameters of the dynamics of the gratings for remote dosimetry and temperature sensing.

  16. Detection of radiation-induced hydrocarbons in baked sponged cake prepared with irradiated liquid egg

    Science.gov (United States)

    Schulzki, G.; Spiegelberg, A.; Bögl, K. W.; Schreiber, G. A.

    1995-02-01

    For identification of irradiated food, radiation-induced volatile hydrocarbons (HC) are determined by gas chromatography in the non-polar fraction of fat. However, in complex food matrices the detection is often disturbed by fat-associated compounds. On-line coupling of high performance liquid chromatography (LC) and gas chromatography (GC) is very efficient to remove such compounds from the HC fraction. The high sensitivity of this fast and efficient technique is demonstrated by the example of detection of radiation-induced HC in fat isolated from baked sponge cake which had been prepared with irradiated liquid egg.

  17. 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.

  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. Radiological and functional assessment of radiation-induced lung injury in the rat

    NARCIS (Netherlands)

    Vujaskovic, Z; Down, JD; van t'Veld, AA; Mooyaart, EL; Meertens, H; Piers, DA; Szabo, BG; Konings, AWT

    1998-01-01

    The purpose of this study is to develop an experimental model to measure localized radiation-induced lung injury using multiple end-points including breathing frequency, high-resolution computed tomography (CT), and radionuclide perfusion. The rats were anaesthetized and the right lung irradiated wi

  20. Radiation-induced sterility for pupal and adult stages of the malaria moquito Anopheles arabiensis

    OpenAIRE

    Helinski, M.E.H.; Parker, A.G.; Knols, B.G.J.

    2006-01-01

    Background - In the context of the Sterile Insect Technique (SIT), radiation-induced sterility in the malaria mosquito Anopheles arabiensis Patton (Diptera: Culicidae) was studied. Male mosquitoes were exposed to gamma rays in the pupal or adult stage and dose-sterility curves were determined. Methods - Pupae were irradiated shortly before emergence (at 22-26 hrs of age), and adults

  1. Factors modifying radiation induced stimulation in plants: pre-irradiation seed moisture content

    International Nuclear Information System (INIS)

    The effect of moisture content of seeds at the time of irradiation in relation to radiation-induced stimulation was investigated on rice. The optimum moisture content was 8% for stimulation measured as seedling height. It is concluded that seed moisture at the time of irradiation plays an important role in the expression of stimulation and its reproducibility. (orig.)

  2. Radiation-induced conductivity and high-temperature Q changes in quartz resonators

    International Nuclear Information System (INIS)

    While high temperature electrolysis has proven beneficial as a technique to remove interstitial impurities from quartz, reliable indices to measure the efficacy of such a processing step are still under development. The present work is directed toward providing such an index. Two techniques have been investigated - one involves measurement of the radiation induced conductivity in quartz along the optic axis, and the second involves measurement of high temperature Q changes. Both effects originate when impurity charge compensators are released from their traps, in the first case resulting in ionic conduction and in the second case resulting in increased acoustic losses. Radiation induced conductivity measurements have been carried out with a 200 kV, 14 mA x-ray machine producing 5 rads/s. With electric fields of the order of 104 V/cm, the noise level in the current measuring system is equivalent to an ionic current generated by quartz impurities in the 1 ppB range. The accuracy of the high temperature ( 300 to 8000K) Q-1 measurement technique will be determined. A number of resonators constructed of quartz material of different impurity contents have been tested and both the radiation induced conductivity and the high temperature Q-1 results compared with earlier radiation induced frequency and resonator resistance changes. 10 figures

  3. Radiation damage to the heart enhances early radiation-induced lung function loss

    NARCIS (Netherlands)

    van Luijk, P; Novakova-Jiresova, A; Faber, H; Schippers, JM; Kampinga, HH; Meertens, H; Coppes, RP

    2005-01-01

    In many thoracic cancers, the radiation dose that can safely be delivered to the target volume is limited by the tolerance dose of the surrounding lung tissue. It has been hypothesized that irradiation of the heart may be an additional risk factor for the development of early radiation-induced lung

  4. Radiation induced renal arterial stenosis detected by color duplex ultrasonography: case report

    Institute of Scientific and Technical Information of China (English)

    Jing Gao; Byong K Park; Arnold Alday

    2005-01-01

    Renal artery stenosis as a complication from radiation therapy is not common, but it is life threatening and needs to be corrected urgently in order to prevent renal failure even losing kidney. The diagnostic criteria of renal artery stenosis in the adults by color duplex ultrasonography have been established, which may play an important role in screening radiation induced renal artery stenosis.

  5. A Prospective Cohort Study on Radiation-induced Hypothyroidism: Development of an NTCP Model

    International Nuclear Information System (INIS)

    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 measured during a median follow-up of 2.5 years. Hypothyroidism was defined as elevated serum TSH with decreased or normal free thyroxin (T4). A multivariate logistic regression model with bootstrapping was used to determine the most important prognostic variables for radiation-induced hypothyroidism. Results: Thirty-five patients (33%) developed primary hypothyroidism within 2 years after radiation therapy. An NTCP model based on 2 variables, including the mean thyroid gland dose and the thyroid gland volume, was most predictive for radiation-induced hypothyroidism. NTCP values increased with higher mean thyroid gland dose (odds ratio [OR]: 1.064/Gy) and decreased with higher thyroid gland volume (OR: 0.826/cm3). Model performance was good with an area under the curve (AUC) of 0.85. Conclusions: This is the first prospective study resulting in an NTCP model for radiation-induced hypothyroidism. The probability of hypothyroidism rises with increasing dose to the thyroid gland, whereas it reduces with increasing thyroid gland volume.

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

    DEFF Research Database (Denmark)

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

    1977-01-01

    Several reports have been published showing that the radiation induced grafting of bifunctional vinyl monomers to low density polyethylene results in a product with an unusually high density of crosslinks. The same grafting reactions are shown to reduce the incipient gel dose by more than a facto...

  7. Role of Rosemary leaves extract against radiation-induced hematological and biochemical alterations in mice

    Directory of Open Access Journals (Sweden)

    Acharya Garima S.

    2008-01-01

    Full Text Available The present paper is a study of the modulatory effect of Rosmarinus officinalis leaves extract on radiation-induced hematological and biochemical changes in Swiss albino mice. The dose reduction factor for the Rosemary extract against gamma rays was calculated 1.53 from LD50/30 values. The Rosemary extract was administered orally for 5 consecutive days prior to radiation exposure. The hematological and biochemical parameters were assessed from day 1 to 30 post-irradiation intervals. The total erythrocyte count, total leucocytes count, hemoglobin, and hematocrit values in the experimental group were found to be elevated as compared to the control group of mice. Furthermore, the Rosemary extract treatment enhanced reduced glutathione content in the liver and blood against radiation-induced depletion. Treatment with the plant extract brought a significant fall in the lipid peroxidation level, suggesting rosemary's role in protection against radiation-induced membrane and cellular damage. The results from the present study suggest a radio-protective effect of the Rosemary extract against radiation-induced hematological and biochemical alterations in mice.

  8. Radiation-induced apoptosis in relation to acute impairment of rat salivary gland function

    NARCIS (Netherlands)

    Paardekooper, GMRM; Cammelli, S; Zeilstra, LJW; Coppes, RP; Konings, AWT

    1998-01-01

    Purpose: To find an answer to the question: Are the acute radiation effects on salivary gland function, as seen in earlier studies, causally related to radiation-induced apoptosis? Materials and methods: Rat parotid and submandibular glands were X-irradiated with doses up to 25 Gy and morphological

  9. Radiation induced cell loss in rat submandibular gland and its relation to gland function

    NARCIS (Netherlands)

    Zeilstra, LJW; Vissink, A; Konings, AWT; Coppes, RP

    2000-01-01

    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 a

  10. THE ROLE OF SECRETORY GRANULES IN RADIATION-INDUCED DYSFUNCTION OF RAT SALIVARY-GLANDS

    NARCIS (Netherlands)

    PETER, B; VANWAARDE, MAWH; VISSINK, A; SGRAVENMADE, EJ; KONINGS, AWT

    1995-01-01

    To investigate the possible role of secretory granules in radiation-induced salivary gland dysfunction, rats were pretreated with isoproterenol (5 mg/kg intraperitoneally) to degranulate salivary gland acini, At maximal depletion, salivary glands were locally irradiated with a single dose of 15 Gy o

  11. RADIATION-INDUCED CELL-PROLIFERATION IN THE PAROTID AND SUBMANDIBULAR GLANDS OF THE RAT

    NARCIS (Netherlands)

    PETER, B; VANWAARDE, MAWH; VISSINK, A; SGRAVENMADE, EJ; KONINGS, AWT

    1994-01-01

    Repopulation of tissues with cells at damaged sites is an important feature in the recovery of radiation-induced tissue injury. To obtain insight into the regenerative process in salivary gland tissue, proliferative activity was measured as a function of time in the different epithelial cell compart

  12. Mechanism of radiation-induced diacylglycerol production in primary cultured rat hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Tetsuo; Yukawa, Osami [National Inst. of Radiological Sciences, Chiba (Japan)

    1999-06-01

    Protein kinase C (PKC) is known to be a key enzyme in radiation-induced signal transduction pathways. We have previously demonstrated that {gamma}-irradiation induces PKC activation and translocation from cytosol to membranes as a consequence of membrane lipid peroxidation in cultured rat hepatocytes (Int. J. Radiat. Biol. 70, 473-480, 1996). The present study was undertaken to investigate production of diacylglycerol, an endogenous activator of PKC, following {gamma}-irradiation of hepatocytes. Diacylglycerol content increased 3 min after irradiation, then decreased at 15 min and increased again at 30 min, indicating a biphasic pattern. This result implies participation of diacylglycerol in the radiation-induced activation of PKC in hepatocytes. In order to clarify the mechanism of the initial process of radiation-induced diacylglycerol production, the effects of reactive oxygens were investigated. Treatment of cells with hydroxyl radical, a major oxygen radical produced by radiation, induced diacylglycerol production without any change in the content of phosphatidylcholine, showing a peak at 1 min after treatment. No change in the diacylglycerol content was observed at that time by hydrogen peroxide treatment. Furthermore, the diacylglycerol production by hydroxyl radical was inhibited by pretreatment with neomycin sulfate, a phosphatidylinositol-specific phospholipase C (PI-PLC) inhibitor. These results suggest that radiation exerts PI-PLC activation through hydroxyl radical generation, followed by diacylglycerol production and PKC activation. (author)

  13. Radiation-induced medulloblastoma in an adult: A functional imaging study

    Directory of Open Access Journals (Sweden)

    Padma M

    2004-01-01

    Full Text Available We describe functional imaging findings using MRI, 1H-Magnetic resonance spectroscopy and positron emission tomography in a case of radiation-induced medulloblastoma following radiotherapy for pineal gland tumor. MRS showed a prominent choline peak; FDG, 11C-Met and 11C-Choline PET showed a minimal glucose, increased methionine and choline uptake.

  14. Further characterization of the reverse transcriptase associated with porcine (radiation-induced) retroviruses

    International Nuclear Information System (INIS)

    Differential centrifugation and affinity chromatography were used to purify the porcine, radiation-induced retrovirus, RNA-dependent DNA polymerase. The purified RDDP was taken differentiated from cellular DNA polymerase γ by its template specificity, chromatographic characteristics, and the optimum reaction conditions required for DNA synthesis

  15. 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.

  16. Neurogenic differentiation factor NeuroD confers protection against radiation-induced intestinal injury in mice.

    Science.gov (United States)

    Li, Ming; Du, Aonan; Xu, Jing; Ma, Yanchao; Cao, Han; Yang, Chao; Yang, Xiao-Dong; Xing, Chun-Gen; Chen, Ming; Zhu, Wei; Zhang, Shuyu; Cao, Jianping

    2016-01-01

    The gastrointestinal tract, especially the small intestine, is particularly sensitive to radiation, and is prone to radiation-induced injury as a result. Neurogenic differentiation factor (NeuroD) is an evolutionarily-conserved basic helix-loop-helix (bHLH) transcription factor. NeuroD contains a protein transduction domain (PTD), which allows it to be exogenously delivered across the membrane of mammalian cells, whereupon its transcription activity can be unleashed. Whether NeuroD has therapeutic effects for radiation-induced injury remains unclear. In the present study, we prepared a NeuroD-EGFP recombinant protein, and explored its protective effects on the survival and intestinal damage induced by ionizing radiation. Our results showed that NeuroD-EGFP could be transduced into small intestine epithelial cells and tissues. NeuroD-EGFP administration significantly increased overall survival of mice exposed to lethal total body irradiation (TBI). This recombinant NeuroD also reduced radiation-induced intestinal mucosal injury and apoptosis, and improved crypt survival. Expression profiling of NeuroD-EGFP-treated mice revealed upregulation of tissue inhibitor of metalloproteinase 1 (TIMP-1), a known inhibitor of apoptosis in mammalian cells. In conclusion, NeuroD confers protection against radiation-induced intestinal injury, and provides a novel therapeutic clinical option for the prevention of intestinal side effects of radiotherapy and the treatment of victims of incidental exposure. PMID:27436572

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

    International Nuclear Information System (INIS)

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

  18. A Nonhuman Primate Model of Human Radiation-Induced Venocclusive Liver Disease and Hepatocyte Injury

    International Nuclear Information System (INIS)

    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

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

    Directory of Open Access Journals (Sweden)

    B.H. Bakkal

    2013-09-01

    Full Text Available 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. Stem Cell Therapy to Reduce Radiation-Induced Normal Tissue Damage

    NARCIS (Netherlands)

    Coppes, Rob P.; van der Goot, Annemieke; Lombaert, Isabelle M. A.

    2009-01-01

    Normal tissue damage after radiotherapy is still a major problem in cancer treatment. Stem cell therapy may provide a means to reduce radiation-induced side effects and improve the quality of life of patients. This review discusses the current status in stem cell research with respect to their poten

  1. Stem cells and the repair of radiation-induced salivary gland damage

    NARCIS (Netherlands)

    Coppes, R. P.; Stokman, M. A.

    2011-01-01

    Hyposalivation underlying xerostomia after radiotherapy is still a major problem in the treatment of head and neck cancer. Stem cell therapy may provide a means to reduce radiation-induced hyposalivation and improve the quality of life of patients. This review discusses the current status in salivar

  2. TGF-beta, radiation-induced pulmonary Injury and lung cancer

    NARCIS (Netherlands)

    Vujaskovic, Z; Groen, HJM

    2000-01-01

    Purpose: To determine whether changes in TGF-beta plasma levels during radiation therapy may be useful in predicting radiation-induced pulmonary injury and tumour response in non-small-cell lung cancer (NSCLC) patients. Materials and methods: Plasma TGF-beta was investigated in 27 patients with stag

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

    International Nuclear Information System (INIS)

    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

  4. 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 measure

  5. A Prospective Cohort Study on Radiation-induced Hypothyroidism: Development of an NTCP Model

    Energy Technology Data Exchange (ETDEWEB)

    Boomsma, Marjolein J.; Bijl, Hendrik P.; Christianen, Miranda E.M.C.; Beetz, Ivo; Chouvalova, Olga; Steenbakkers, Roel J.H.M. [Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Laan, Bernard F.A.M. van der [Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Wolffenbuttel, Bruce H.R. [Department of Endocrinology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Oosting, Sjoukje F. [Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Schilstra, Cornelis [Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Langendijk, Johannes A., E-mail: j.a.langendijk@umcg.nl [Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands)

    2012-11-01

    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 measured during a median follow-up of 2.5 years. Hypothyroidism was defined as elevated serum TSH with decreased or normal free thyroxin (T4). A multivariate logistic regression model with bootstrapping was used to determine the most important prognostic variables for radiation-induced hypothyroidism. Results: Thirty-five patients (33%) developed primary hypothyroidism within 2 years after radiation therapy. An NTCP model based on 2 variables, including the mean thyroid gland dose and the thyroid gland volume, was most predictive for radiation-induced hypothyroidism. NTCP values increased with higher mean thyroid gland dose (odds ratio [OR]: 1.064/Gy) and decreased with higher thyroid gland volume (OR: 0.826/cm{sup 3}). Model performance was good with an area under the curve (AUC) of 0.85. Conclusions: This is the first prospective study resulting in an NTCP model for radiation-induced hypothyroidism. The probability of hypothyroidism rises with increasing dose to the thyroid gland, whereas it reduces with increasing thyroid gland volume.

  6. Radiation-induced hypothyroidism in head and neck cancer patients : A systematic review

    NARCIS (Netherlands)

    Boomsma, Marjolein J.; Bijl, Hendrik P.; Langendijk, Johannes A.

    2011-01-01

    Purpose: To review literature on the relationship between the dose distribution in the thyroid gland and the incidence of radiation-induced hypothyroidism in adults. Material and Methods: Articles were identified through a search in MEDLINE, EMBASE and the Cochrane Library. Approximately 2449 articl

  7. 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)

  8. Physiology of Hormone Autonomous Tissue Lines Derived From Radiation-Induced Tumors of Arabidopsis thaliana.

    Science.gov (United States)

    Campell, B R; Town, C D

    1991-11-01

    gamma-Radiation-induced tumors of Arabidopsis thaliana L. have been produced as a novel approach to isolation of genes that regulate plant development. Tumors excised from irradiated plants are hormone autonomous in culture and have been maintained on hormone-free medium for up to 4 years. Five tumor tissue lines having different morphologies and growth rates were analyzed for auxin, cytokinin, and 1-aminocyclopropane-1-carboxylic acid (ACC) content, ethylene production, and response to exogenous growth regulators. Normal tissues and two crown gall tissue lines were analyzed for comparison. Rosettes and whole seedlings each contained approximately 30 nanograms. (gram fresh weight)(-1) free indoleacetic acid (IAA), 150 nanograms. (gram fresh weight)(-1) ester-conjugated IAA, and 10 to 20 micrograms. (gram fresh weight)(-1) amide-conjugated IAA. The crown gall lines contained similar amounts of free and ester-conjugated IAA but less amide conjugates. Whereas three of the radiation-induced tumor lines had IAA profiles similar to normal tissues, one line had 10- to 100-fold more free IAA and three- to 10-fold less amide-conjugated IAA. The fifth line had normal free IAA levels but more conjugated IAA than control tissues. Whole seedlings contained approximately 2 nanograms. (gram fresh weight)(-1) of both zeatin riboside and isopentenyladenosine. The crown gall lines had 100- to 1000-fold higher levels of each cytokinin. In contrast, the three radiation-induced tumor lines analyzed contained cytokinin levels similar to the control tissue. The radiation-induced tumor tissues produced very little ethylene, although each contained relatively high levels of ACC. Normal callus contained similar amounts of ACC but produced several times more ethylene than the radiation-induced tumor lines. Each of the radiation-induced tumor tissues displayed a unique set of responses to exogenously supplied growth regulators. Only one tumor line showed the same response as normal callus to

  9. Physiology of Hormone Autonomous Tissue Lines Derived From Radiation-Induced Tumors of Arabidopsis thaliana 1

    Science.gov (United States)

    Campell, Bruce R.; Town, Christopher D.

    1991-01-01

    γ-Radiation-induced tumors of Arabidopsis thaliana L. have been produced as a novel approach to isolation of genes that regulate plant development. Tumors excised from irradiated plants are hormone autonomous in culture and have been maintained on hormone-free medium for up to 4 years. Five tumor tissue lines having different morphologies and growth rates were analyzed for auxin, cytokinin, and 1-aminocyclopropane-1-carboxylic acid (ACC) content, ethylene production, and response to exogenous growth regulators. Normal tissues and two crown gall tissue lines were analyzed for comparison. Rosettes and whole seedlings each contained approximately 30 nanograms· (gram fresh weight)−1 free indoleacetic acid (IAA), 150 nanograms· (gram fresh weight)−1 ester-conjugated IAA, and 10 to 20 micrograms· (gram fresh weight)−1 amide-conjugated IAA. The crown gall lines contained similar amounts of free and ester-conjugated IAA but less amide conjugates. Whereas three of the radiation-induced tumor lines had IAA profiles similar to normal tissues, one line had 10- to 100-fold more free IAA and three- to 10-fold less amide-conjugated IAA. The fifth line had normal free IAA levels but more conjugated IAA than control tissues. Whole seedlings contained approximately 2 nanograms· (gram fresh weight)−1 of both zeatin riboside and isopentenyladenosine. The crown gall lines had 100- to 1000-fold higher levels of each cytokinin. In contrast, the three radiation-induced tumor lines analyzed contained cytokinin levels similar to the control tissue. The radiation-induced tumor tissues produced very little ethylene, although each contained relatively high levels of ACC. Normal callus contained similar amounts of ACC but produced several times more ethylene than the radiation-induced tumor lines. Each of the radiation-induced tumor tissues displayed a unique set of responses to exogenously supplied growth regulators. Only one tumor line showed the same response as normal callus to

  10. [Radiation-induced damage of mitochondrial genome and its role in long-term effects of irradiation].

    Science.gov (United States)

    Berogovskaia, N N; Savich, A V

    1994-01-01

    The role of mt-genome mutations in radiation-induced carcinogenesis has been hypothesized. The data on radiation chemistry of nucleic acids has been used to evaluate mutagenic effect of carcinogenic doses of ionizing radiation. The assumptions about the ways of biological augmentation of primary radiation-induced lesions in mt-genome has been given. PMID:8069366

  11. 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

  12. Applications of Natural Radiation-Induced Paramagnetic Defects in Quartz to Exploration in Sedimentary Basins

    Institute of Scientific and Technical Information of China (English)

    Pan Y M; Botis S; Nokhrin S

    2006-01-01

    Quartz grains in contact with uranium-bearing minerals or fluids are characterized by natural radiation-induced paramagnetic defects (e. G. , oxygen vacancy centers, silicon vacancy centers, and peroxy radicals), which are amenable to study by electron paramagnetic resonance (EPR) spectroscopy.These natural radiation-induced paramagnetic defects, except for the oxygen vacancy centers, in quartz are concentrated in narrow bands penetrated by α particles: (1) in halos around U- and Th-bearing mineral inclusions and (2) in outer rims or along fractures. The second type of occurrence provides information about uranium mineralization or remobilization (I. E. , sources of uranium, timing of mineralization or remobilization, pathways of uranium-bearing fluids). It can also be used to evaluate sedimentary basins for potential of uranium mineralization. In particular, the peroxy radicals are stable up to 800℃and, therefore, are useful for evaluating metasedimentary rocks (e. G. , Paleoproterozoic metasedimentary sequences in the central zone of the North China craton). EPR study of the Changcheng Series can focus on quartz from the sediment-basement unconformity and faults to determine the presence and types of natural radiation-induced paramagnetic defects, with which to identify and prioritize uranium anomalies. Other potential applications of natural radiation-induced paramagnetic defects in quartz include uranium-bearing hydrocarbon deposits in sedimentary basins. For example, the Junggar, Ordos, and Tarim basins in northwestern China all contain important oil and natural gas fields and are well known for elevated uranium concentrations, including economic sandstone-hosted uranium deposits. Therefore,systematic studies on the distribution of natural radiation-induced paramagnetic defects in quartz from host sedimentary sequences are expected to provide information about the migration of oil and natural gas in those basins.

  13. A novel topical protectant for the prevention of β-radiation induced moist desquamation

    International Nuclear Information System (INIS)

    Full text: Effective therapies for the prevention of radiation-induced skin burns that could be readily deployed under a nuclear accident or nuclear terrorism scenario are urgently needed. In this report we describe the efficacy of a novel radioprotectant (DMZ911) in a model of b-radiation induced moist desquamation (MD) in pig skin. DMZ911 is a nitroxide-based topical cream that effectively delivers the nitroxide into viable skin cells. Stable nitroxide compounds have been shown to be effective against both X-ray and ?-ray-induced damage in vivo and in vitro. A pig skin model of β-radiation-induced MD was employed in this study. Exposure to 30 Gy was used to induce skin lesions involving >80% moist desquamation in prescribed test sites on flank skin of female Large White pigs. DMZ911 or placebo was applied to various test sites 2 hours prior to radiation exposure. Lesions were scored based on the area of the test site containing 50% MD (severe) as determined by clinical assessment using blinded observers. Treatment with DMZ911 resulted in a 31% net reduction in MD when compared to placebo treated sites following an 8-week study period. This reduction was observed whether all sites or only those with severe MD were considered. Skin damage (as indicated by MD) from radiation exposure was significantly reduced by 31% (p = 0.05) following pretreatment with the novel topical radioprotectant DMZ911. This observation suggests that skin lesion development from radiation-induced oxidative damage cascades may be successfully inhibited by treatment with DMZ911. This topical therapeutic agent represents a novel treatment for nuclear radiation induced skin injury. DMZ911 may have unique applications in radiation oncology, cosmetic and therapeutic UV, laser, glycolic and dermabrasion procedures

  14. Gene expression profiling of alpha-radiation-induced rat osteosarcomas: Identification of dys-regulated genes involved in radiation-induced tumorigenesis of bone

    Energy Technology Data Exchange (ETDEWEB)

    Daino, K.; Ugolin, N.; Altmeyer-Morel, S.; Guilly, M.N.; Chevillard, S. [Laboratoire de Cancerologie Experimentale, iRCM, DSV, CEA, Fontenay-aux-Roses (France)

    2009-07-01

    To better understand the molecular basis of radiation-induced osteosarcoma (OS), we performed global gene expression profiling of rat OS tumors induced by the bone-seeking alpha emitter {sup 238}Pu, and the expression profiles were compared with those of normal osteoblasts (OB). The expressions of 72 genes were significantly differentially expressed in the tumors related to OB. These included genes involved in the cell adhesion (e.g., Podxl, Col18a1, Cd93, Emcn and Vcl), differentiation, developmental processes (e.g., Hhex, Gata2, P2ry6, P2rx5, Cited2, Osmr and Igsf10), tumor suppressor function (e.g., Nme3, Blcap and Rrm1), Src tyrosine kinase signaling (e.g., Hck, Shf, Arhgap29, Cttn and Akap12), and Wnt/b-catenin signaling (e.g., Fzd6, Lzic, Dkk3 and Ctnna1) pathways. Expression changes of several genes were validated by quantitative real-time RT-PCR analysis. Notably, all of the identified genes involved in the Wnt/{beta}-catenin signaling pathway were known or proposed to be negative regulators of this pathway and were down-regulated in the tumors, suggesting the activation of {beta}-catenin in radiation-induced OS. By using immunohistochemical and immunoblot analyses, constitutive activation of the Wnt/{beta}-catenin signaling pathway in the tumors was confirmed by observing nuclear and/or cytoplasmic localization of {beta}-catenin and a decrease in its inactive (phosphorylated) form. Furthermore, we found a significant reduction in the levels of glycogen synthase kinase 3b (GSK-3b) protein in the tumors relative to OB. Taken together, these findings provide new insights into the molecular basis of radiation-induced OS. (authors)

  15. Urine - abnormal color

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003139.htm Urine - abnormal color To use the sharing features on this page, please enable JavaScript. The usual color of urine is straw-yellow. Abnormally colored urine ...

  16. Radiation-induced cytogenetic and hematologic effects on aquatic biota within the Chernobyl exclusion zone

    Energy Technology Data Exchange (ETDEWEB)

    Gudkov, Dmitri I.; Shevtsova, Natalia L.; Pomortseva, Natalia A.; Kaglyan, Alexander Ye. [Institute of Hydrobiology, Geroyev Stalingrada Ave. 12, UA-04210 Kiev (Ukraine); Dzyubenko, Elena V. [G. Skovoroda Pereyaslav-Khmelnitsk State Teacher Training University, Sukhomlinskogo Str. 30, UA-08401 Pereyaslav-Khmelnitsk (Ukraine); Rodionova, Natalia K. [R.E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology, Vasilkovskaya Str. 45, UA-04073 Kiev (Ukraine); Nazarov, Alexander B. [Chernobyl Specialized Enterprise, Radyanska Str. 70, UA-07270 Chernobyl (Ukraine)

    2014-07-01

    water bodies within the ChEZ repeatedly exceeds the level of spontaneous mutagenesis, inherent to the aquatic species (2.0-2.5%) and can be display of radiation-induced genetic instability. In fish dwelling in lakes of the ChEZ a considerable qualitative and quantitative changes in hematopoietic system were registered. In water bodies with high level of radioactive contamination the content of leucocytes in blood of fish was substantially below than their level in fish of the control reservoirs. At that the total amount of thrombocytes in fish from contaminated lakes was higher than control indexes. In blood of the perch from Glubokoye Lake the decreased content of oval forms of thrombocytes was determined. The erythrocytes of the crucian carp and perch from Glubokoye Lake were the most susceptible to pathological changes of both nucleus and cell wall. The total amount of cell abnormality in this water body was registered at following level: for the crucian carp 59.5 0/00, and for the perch 22.6 0/00, that considerably exceeds the indexes of violations for fish from control reservoirs (1.9-4.1 0/00). Among the studied fish of the ChEZ we have not detected individuals without cellular pathologies in peripheral blood. (authors)

  17. 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.

  18. Treatment of radiation-induced hemorrhagic gastritis with prednisolone: A case report

    Institute of Scientific and Technical Information of China (English)

    Lan Zhang; Xiao-Ying Xie; Yan Wang; Yan-Hong Wang; Yi Chen; Zheng-Gang Ren

    2012-01-01

    Radiation-induced gastritis is an infrequent cause of gastrointestinal bleeding.It is a serious complication arising from radiation therapy,and the standard treatment method has not been established.The initial injury is characteristically acute inflammation of gastric mucosa.We presented a 46-year-old male patient with hemorrhagic gastritis induced by external radiotherapy for metastatic retroperitoneal lymph node of hepatocellular carcinoma.The endoscopic examination showed diffuse edematous hyperemicmucosa with telangiectasias in the whole muscosa of the stomach and duodenal bulb.Mlultiple hemorrhagic patches with active oozing were found over the antrum.Anti-secretary therapy was initiated for hemostasis,but melena still occurred off and on.Finally,he was successfully treated by prednisolone therapy.We therefore strongly argue in favor of perdnisolone therapy to effectively treat patients with radiation-induced hemorrhagic gastritis.

  19. A case showing effective radiotherapy for a radiation-induced glioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Fukui, Kimiko; Inamura, Takanori; Nakamizo, Akira; Ikezaki, Kiyonobu; Inoha, Satoshi; Nakamura, Kazumasa; Matsuzaki, Akinobu; Fukui, Masashi [Kyushu Univ., Fukuoka (Japan). Graduate School of Medical Sciences

    2001-07-01

    Radiation-induced glioblastoma is usually resistant to all treatments. We report a case with radiation-induced glioblastoma, in which radiotherapy was remarkably effective. A 14-year-old female with a history of acute lymphoblastic leukemia, at the age of 7, underwent 15 Gy of radiotherapy to the whole brain. She was admitted to our department due to the development of headache and nausea. Magnetic resonance imaging showed an irregularly enhanced mass in the left frontal lobe. Partial removal of the mass was performed and histological examination showed it to be glioblastoma with a high MIB-1 index. The patient underwent 40 Gy of local radiotherapy and chemotherapy with ACNU and Interferon-{beta} for 2 years. The residual tumor disappeared after the radiotherapy, and her status is still ''complete remission'', 29 months after the onset. (author)

  20. Relation between measurable and principal characteristics of radiation-induced shape-change of graphite

    CERN Document Server

    Arjakov, M V; Panyukov, S V; Ivanov, O V; Pokrovskii, A S; Kharkov, D V

    2011-01-01

    On the basis of studies of radiation-induced shape-change of reactor graphite GR-280, through the series of measurements of samples with different orientation of cutting with respect to the direction of extrusion, a conclusion is made about the existence of polycrystal substructural elements - domains. Domains, like graphite as a whole, possess the property of transverse isotropy, but have different amplitudes of shape-change and random orientations of the axes of axial symmetry. The model of graphite, constructed on the basis of the concept of domains allowed to explain from a unified point of view most of existing experimental data. It is shown that the presence of the disoriented domain structure leads to the development of radiation-induced stresses and to the dependence of the shape-change on the size of graphite samples. We derive the relation between the shape-change of finite size samples and the actual shape-change of macro-graphite.

  1. Radiation-induced osteochondroma of the T4 vertebra causing spinal cord compression

    Energy Technology Data Exchange (ETDEWEB)

    Gorospe, Luis; Madrid-Muniz, Carmen; Royo, Aranzazu; Garcia-Raya, Pilar [Department of Radiology, La Paz University Hospital, Madrid (Spain); Alvarez-Ruiz, Fernando [Department of Neurosurgery, La Paz University Hospital, Madrid (Spain); Lopez-Barea, Fernando [Department of Pathology, La Paz University Hospital, Madrid (Spain)

    2002-04-01

    A case of a radiation-induced osteochondroma arising from the vertebral body of T4 in an 18-year-old man is reported. The patient presented with a history of progressive left lower extremity weakness. At 7 years of age, he had undergone resection of a cerebellar medulloblastoma and received adjunctive craniospinal irradiation and systemic chemotherapy. Both CT and MR imaging revealed an extradural mass contiguous with the posteroinferior endplate of the T4 vertebral body. This case indicates that radiation-induced osteochondroma should be considered in the differential diagnosis of patients with symptoms of myelopathy or nerve root compression and a history of radiation therapy involving the spine in childhood. (orig.)

  2. Radiation-induced increase in the release of amino acids by isolated, perfused skeletal muscle

    International Nuclear Information System (INIS)

    Local exposure of the hindquarter of the rat to 15Gy of gamma-radiation resulted, 4-6h after irradiation, in increased release of amino acids by the isolated, perfused hindquarter preparation, 70% of which is skeletal muscle. This increase in release involves not only alanine and glutamine, but also those amino acids not metabolized by muscle and, therefore, released in proportion to their occurrence in muscle proteins. Because metabolic parameters and content of energy-rich phosphate compounds in muscle remain unchanged, it is unlikely that general cellular damage is the underlying cause of the radiation-induced increase in amino acid release. The findings strongly favour the hypothesis that increased availability of amino acids results from enhanced protein break-down in skeletal muscle which has its onset shortly after irradiation. This radiation-induced disturbance in protein metabolism might be one of the pathogenetic factors in the aetiology of radiation myopathy. (author)

  3. Radiation-induced reactions of the lungs: Hormesis, guideline on radiation protection in medicine

    International Nuclear Information System (INIS)

    The proceedings contain almost all full papers presented at the 34th annual meeting of the Vereinigung Deutscher Strahlenschutzaerzte e.V., held in Dresden from May 3-5, 1993. There were three main topics selected for this meeting: radiation-induced reactions in the lungs, radiation hormesis, and the German regulatory guide for Radiation Protection in Medicine, as amended in mid-1993. The papers discuss the pathogenesis of radiation-induced lesions in the lungs, results of animal experiments applying partial and whole-lung irradiation, clinical experience and diagnostics, lung function impairment, and X-ray signs of the thorax after radiation exposure of the respiratory organ. The two papers discussing the effects of low doses of ionizing radiation, radiation hormesis and adaptive response in biological systems have been presented by experts in this matter which give a picture of the current scientific knowledge and of the items of controversy. (orig./MG)

  4. Radiation-induced transient attenuation of optical fibers at 800 and 1300 nm

    International Nuclear Information System (INIS)

    Radiation-induced absorption in optical fibers has been a subject of considerable interest throughout the world. As availability and applications of fibers have evolved from ''first window'' systems operating near 850 nm to ''second window'' systems near 1300 nm, interest in wavelength dependence of radiation effects in optical fibers has similarly evolved. The present work summarizes second-window, radiation-induced transient absorption measurements in optical fibers for times shorter than 5 μs. Comparisons to first window data for these fibers are also presented. Only high purity silica fibers with low-OH concentrations were used in the present study to avoid the large OH absorption band in this region. This paper also collects first window data on several high-OH optical fibers

  5. Identification of radiation induced dark current sources in pinned photodiode CMOS image sensors

    International Nuclear Information System (INIS)

    This paper presents an investigation of Total Ionizing Dose (TID) induced dark current sources in Pinned Photodiodes (PPD) CMOS Image Sensors based on pixel design variations. The influence of several layout parameters is studied. Only one parameter is changed at a time enabling the direct evaluation of its contribution to the observed device degradation. By this approach, the origin of radiation induced dark current in PPD is localized on the pixel layout. The PPD peripheral shallow trench isolation does not seem to play a role in the degradation. The PPD area and a transfer gate contribution independent of the pixel dimensions appear to be the main sources of the TID induced dark current increase. This study also demonstrates that applying a negative voltage on the transfer gate during integration strongly reduces the radiation induced dark current. (authors)

  6. A radiation-induced breast cancer following artificial pneumothorax therapy for pulmonary tuberculosis

    International Nuclear Information System (INIS)

    A case of radiation-induced breast cancer in a woman who had been fluoroscopied repeatedly for control of pneumothorax for pulmonary tuberculosis 35 years before is reported. The breast tissue presumably received about 136 rads or less in three and a half years. In Japan, both prospective and retrospective surveies following multiple fluoroscopies during artificial pneumothorax collaps therapy have failed to show an increase in the risk of subsequent development of primary breast cancer. The dose given to breast tissues in Japanese patients was generally far less than that in the MacKenzie's series. A radiation-induced breast cancer in Japanese literature has not yet been reported. It seems that the lesser doses may explain the reason of this fact. (auth.)

  7. Evaluating the role of mitochondrial DNA variation to the genetic predisposition to radiation-induced toxicity

    International Nuclear Information System (INIS)

    Background and purpose: Mitochondrial DNA common variants have been reported to be associated with the development of radiation-induced toxicity. Using a large cohort of patients, we aimed to validate these findings by investigating the potential role of common European mitochondrial DNA SNPs (mtSNPs) to the development of radio-toxicity. Material and methods: Overall acute and late toxicity data were assessed in a cohort of 606 prostate cancer patients by means of Standardized Total Average Toxicity (STAT) score. We carried out association tests between radiation toxicity and a selection of 15 mtSNPs (and the haplogroups defined by them). Results: Statistically significant association between mtSNPs and haplogroups with toxicity could not be validated in our Spanish cohort. Conclusions: The present study suggests that the mtDNA common variants analyzed are not associated with clinically relevant increases in risk of overall radiation-induced toxicity in prostate cancer patients

  8. [Radiation-Induced Radiculopathy with Paresis of the Neck and Autochthonous Back Muscles with Additional Myopathy].

    Science.gov (United States)

    Ellrichmann, G; Lukas, C; Adamietz, I A; Grunwald, C; Schneider-Gold, C; Gold, R

    2016-06-01

    Radiation-induced tissue damage is caused by ionizing radiation mainly affecting the skin, vascular, neuronal or muscle tissue. Early damages occur within weeks and months while late damages may occur months or even decades after radiation.Radiation-induced paresis of the spine or the trunk muscles with camptocormia or dropped-head syndrome are rare but have already been described as long-term sequelae after treatment of Hodgkin's lymphoma. The differential diagnosis includes limb-girdle muscular dystrophy, fascioscapulohumeral muscular dystrophy (FSHD) or lysosomal storage diseases (e. g. Acid Maltase Deficiency). We present the case of a patient with long lasting diagnostics over many months due to different inconclusive results. PMID:27391986

  9. Recombination of charge carriers on radiation-induced defects in silicon doped by transition metals impurities

    CERN Document Server

    Kazakevich, L A

    2003-01-01

    It has been studied the peculiarities of recombination of nonequilibrium charge carriers on radiation-induced defects in received according to Czochralski method p-silicon (p approx 3 - 20 Ohm centre dot cm), doped by one of the impurities of transition metals of the IV-th group of periodic table (titanium, zirconium, hafnium). Experimental results are obtained out of the analysis of temperature and injection dependence of the life time of charge carriers. The results are explained taking into consideration the influences of elastic stress fields created by the aggregates of transition metals atoms on space distribution over the crystal of oxygen and carbon background impurities as well as on the migration of movable radiation-induced defects during irradiation. (authors).

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

    International Nuclear Information System (INIS)

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

  11. Effect of microstructure on radiation induced segregation and depletion in ion irradiated SS316 steel

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Hyung Ha; Kwon, Sang Chul; Kwon, Jun Hyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-10-15

    Irradiation assisted stress corrosion cracking (IASCC), void swelling and irradiation induced hardening are caused by change of characteristics of material by neutron irradiation, stress state of material and environmental situation. It has been known that chemical compositions varies at grain boundary (GB) significantly with fluence level and the depletion of Cr element at GB has been considered as one of important factors causing material degradation, especially, IASCC in austenitic stainless steel. However, experimental results of IASCC under PWR condition were directly not connected with Cr depletion phenomenon by neutron irradiation. Because the mechanism of IASCC under PWR has not yet been clearly understood in spite of many energetic researches, fundamental researches about radiation induced segregation and depletion in irradiated austenitic stainless steels have been attracted again. In this work, an effect of residual microstructure on radiation induced segregation and depletion of alloy elements at GB was investigated in ion irradiated SS316 steel using transmission electron microscope (TEM) with energy dispersive spectrometer (EDS)

  12. Characteristics of the chrome-tanned sheep leather treated by radiation-induced graft of BA

    International Nuclear Information System (INIS)

    The characteristics of the chrome-tanned sheep leather treated by radiation-induced graft of BA is presented. Using the method of radiation-induced graft of BA instead of the chrome-retanning, the leather has been obviously improved not only in the surface, such as the brightness, fullness, uniformity of the thickness but also in the physical characteristics such as retaining of tensile strength, decreasing of water absorption after being immersed in water for 2h, and 24h, enhancement of tearing strength and stitch tear strength. Although the air permeability and water vapor permeability are a bit worse than the control, however is still in the range of the standard issued by Light Industry Ministry of China

  13. Morphogenesis of the radiation-induced mutant limb deformity (ld) of the common mouse

    International Nuclear Information System (INIS)

    Findings obtained in the thoracic and pelvic extremities of mice of the incest strain C57B1/10; i.e. animals homozygous with regard to the radiation-induced mutation 'limb deformity', are summarized and compared with the findings in non-deformed mice. Further, the deformities and their causes are discussed against the background of other findings. Conclusions may be drawn for the evaluation of the present findings. (orig./MG)

  14. 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.

  15. Reactive oxygen species perpetuate radiation-induced lung injury: causes and cures

    International Nuclear Information System (INIS)

    The risk of unacceptable radiation-induced lung injury remains a significant limiting factor in the current treatment of the tumors involving the thoracic region. Despite advances in normal tissue radiobiology, demonstrating that ionizing radiation triggers a cascade of genetic and molecular events that proceed during a latent period of pulmonary injury, the precise mechanisms underlying radiation-induced lung injury remain unclear. Based on our recent results, we propose a new paradigm of radiation-induced lung injury hypothesizing that hypoxia plays a central role in generating a non-healing wound response that perpetuates radiation lung injury through continuous generation of reactive oxygen species (ROS) and expression/activation of cytokines. Several lines of evidence from our group support this hypothesis. Using electron spin resonance (ESR) and spin trapping we have demonstrated the presence of ROS in rat lungs 13 weeks after irradiation. In a transgenic mouse model we have shown that overexpression of extracellular superoxide dismutase (EC-SOD), an important scavenger of ROS, ameliorates RT-induced lung injury. In addition, our data show that synthetic superoxide dismutase (SOD) mimetic compounds can be used to target ROS and reduce RT-induced lung damage. The findings noted above indicating a role for chronic ROS expression in the perpetuation of a wound healing response, suggest that long term SOD mimetic administration may be an effective therapeutic intervention. This strategy may reduce the risk of radiation-induced lung injury at standard radiation doses and may allow for higher doses of radiation to be delivered to selected tumors without increasing the risk of pulmonary complications

  16. The relevance of radiation induced bystander effects for low dose radiation carcinogenic risk

    International Nuclear Information System (INIS)

    Full text: Where epidemiology studies lack the ability to prescribe radiation doses, customise sample sizes and replicate findings, radiobiology experiments provide greater flexibility to control experimental conditions. This control simplifies the process of answering questions concerning carcinogenic risk after low dose radiation exposures. However, the flexibility requires critical evaluation of radiobiology findings to ensure that the right questions are being asked, the experimental conditions are relevant to human exposure scenarios and that the data are cautiously interpreted in the context of the experimental model. In particular, low dose radiobiology phenomena such as adaptive responses, genomic instability and bystander effects need to be investigated thoroughly, with continual reference to the way these phenomena might occur in the real world. Low dose radiation induced bystander effects are of interest since their occurrence in vivo could complicate the shape of the radiation dose-response curve in the low dose range for a number of biological endpoints with subsequent effects on radiation-induced cancer risk. Conversely, radiation-induced abscopal effects implicate biological consequences of radiation exposure outside irradiated volumes, and complicate the notion of effective dose calculations. Achieving a consensus on the boundaries that distinguish the radiobiology phenomena of bystander and abscopal effects will aid progress towards understanding their relevance to in vivo radiation exposures. A proposed framework for discussing bystander effects and abscopal effects in their appropriate context will be outlined, with a discussion on the future investigation of radiation-induced bystander effects. Such frameworks can assist the integration of results from experimental radiobiology to risk evaluation and management practice. This research was funded by the Low Dose Radiation Research Program, BioI. and Environ. Research, US Dept. of Energy, Grant DE

  17. Radiation induced early delayed changes in mice brain: a 1h MRS and behavioral evaluation study

    International Nuclear Information System (INIS)

    Radiation induced CNS injury can be classified as acute, early delayed and late delayed. Most of the studies suggest that acute injury is reversible whereas early delayed and late delayed injury is irreversible leading to metabolic and cognitive impairment. Extensive research has been carried out on cranial radiation induced early and late delayed changes, there are no reports on whole body radiation induced early and delayed changes. The present study was designed to observe early delayed effects of radiation during whole body radiation exposure. A total of 20 C57 male mice were divided in two groups of 10 animals each. One group was exposed to a dose of 5 Gy whole body radiation through Tele 60Co irradiation facility with source operating at 2.496 Gy/min, while other group served as sham irradiated control. Behavioral and MR spectroscopy was carried out 3 months post irradiation. Behavioral parameters such as locomotor activity and working memory were evaluated first then followed by MR spectroscopy at 7T animal MRI system. For MRS, voxel was localised in the cortex-hippocampus region of mouse brain. MR spectra were acquired using PRESS sequence, FID was processed using LC model for quantitation. The data showed impaired cognitive functions and altered metabolite levels during early delayed phase of whole body radiation induced injury. In behavioural experiments, there was a significant impairment in the cognitive as well as exploratory functions at 3 months post irradiation in irradiated group as compared to controls. MRS results explained changes in mI, glutamine and glx levels in irradiated animals compared to controls. Altered mI level has been found to be associated with reduced cognitive abilities in many brain disorders including MCI and Alzheimer's disease. The findings of this study suggest that whole body radiation exposure may have long lasting effect on the cognitive performance. (author)

  18. Radiation-induced defects in chalcogenide glasses characterized by combined optical spectroscopy, XPS and PALS methods

    International Nuclear Information System (INIS)

    Temperature-dependent optical absorption spectroscopy, high-resolution X-ray photoelectron spectroscopy and positron annihilation lifetimes spectroscopy are utilized to understand radiation-induced changes in Ge-Sb-S chalcogenide glasses. Theoretically predicted topological scheme of γ-induced coordination defect formation in stoichiometric Ge23.5Sb11.8S64.7 glass composition is supported by these measurements. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Radiation-induced effects in chalcogenide glasses: Topological mechanisms and application

    International Nuclear Information System (INIS)

    Structural transformations in vitreous As2S3-based chalcogenide semiconducting glasses induced by γ-irradiation have been considered on the basis of IR Fourier spectroscopy results as destruction-polymerization changes of the covalent chemical bonds, associated with specific coordination defects formation. The whole variety of these processes has been taken into account in order to construct the physically real variants of the radiation-induced structural changes

  20. Optical-spectroscopic signature of radiation-induced instability in glassy arsenic sulphides

    OpenAIRE

    Shpotyuk, Ya.; Polovynko, I.

    2012-01-01

    Optical changes caused by 60Co g-irradiation are studied in glassy-like As2S3. The observed long-wave shift in the range of fundamental optical absorption edge accompanied by increase in transmittance is explained as a manifestation of complicated nature of radiation-induced structural transformations associated with coordination topological defects and additional shrinkage input from natural physical ageing.

  1. Multidisciplinary approach to treatment of radiation-induced chest wall sarcoma.

    Science.gov (United States)

    Kara, H Volkan; Gandolfi, Brad M; Williams, Judson B; D'Amico, Thomas A; Zenn, Michael R

    2016-08-01

    Radiation-induced sarcoma (RIS) is a rare complication following therapeutic external irradiation for lung cancer patients. Patients with RIS may develop recurrence or metastasis of the previous disease and also at high risk for early chest wall complications following operation, which requires close follow-up and multidisciplinary approach. We present a challenging case of RIS with a multidisciplinary teamwork in the decision-making and successful management. PMID:25663293

  2. Role of Rosemary leaves extract against radiation-induced hematological and biochemical alterations in mice

    OpenAIRE

    Acharya Garima S.; Goyal Pradeep K.

    2008-01-01

    The present paper is a study of the modulatory effect of Rosmarinus officinalis leaves extract on radiation-induced hematological and biochemical changes in Swiss albino mice. The dose reduction factor for the Rosemary extract against gamma rays was calculated 1.53 from LD50/30 values. The Rosemary extract was administered orally for 5 consecutive days prior to radiation exposure. The hematological and biochemical parameters were assessed from day 1 to 30 post-irradiation intervals. The total...

  3. Effects of NOX1 on fibroblastic changes of endothelial cells in radiation-induced pulmonary fibrosis

    OpenAIRE

    Choi, Seo-hyun; KIM, MISEON; Lee, Hae-June; Kim, Eun-Ho; Kim, Chun-Ho; Lee, Yoon-Jin

    2016-01-01

    Lung fibrosis is a major complication in radiation-induced lung damage following thoracic radiotherapy, while the underlying mechanism has remained to be elucidated. The present study performed immunofluorescence and immunoblot assays on irradiated human pulmonary artery endothelial cells (HPAECs) with or without pre-treatment with VAS2870, a novel NADPH oxidase (NOX) inhibitor, or small hairpin (sh)RNA against NOX1, -2 or -4. VAS2870 reduced the cellular reactive oxygen species content induc...

  4. Radiation-induced effects in chalcogenide glasses: Topological mechanisms and application

    Energy Technology Data Exchange (ETDEWEB)

    Shpotyuk, O.I. E-mail: karat@ipm.lviv.ua

    2000-05-02

    Structural transformations in vitreous As{sub 2}S{sub 3}-based chalcogenide semiconducting glasses induced by {gamma}-irradiation have been considered on the basis of IR Fourier spectroscopy results as destruction-polymerization changes of the covalent chemical bonds, associated with specific coordination defects formation. The whole variety of these processes has been taken into account in order to construct the physically real variants of the radiation-induced structural changes.

  5. Tristetraprolin mediates radiation-induced TNF-α production in lung macrophages.

    Directory of Open Access Journals (Sweden)

    Dipankar Ray

    Full Text Available The efficacy of radiation therapy for lung cancer is limited by radiation-induced lung toxicity (RILT. Although tumor necrosis factor-alpha (TNF-α signaling plays a critical role in RILT, the molecular regulators of radiation-induced TNF-α production remain unknown. We investigated the role of a major TNF-α regulator, Tristetraprolin (TTP, in radiation-induced TNF-α production by macrophages. For in vitro studies we irradiated (4 Gy either a mouse lung macrophage cell line, MH-S or macrophages isolated from TTP knockout mice, and studied the effects of radiation on TTP and TNF-α levels. To study the in vivo relevance, mouse lungs were irradiated with a single dose (15 Gy and assessed at varying times for TTP alterations. Irradiation of MH-S cells caused TTP to undergo an inhibitory phosphorylation at Ser-178 and proteasome-mediated degradation, which resulted in increased TNF-α mRNA stabilization and secretion. Similarly, MH-S cells treated with TTP siRNA or macrophages isolated from ttp (-/- mice had higher basal levels of TNF-α, which was increased minimally after irradiation. Conversely, cells overexpressing TTP mutants defective in undergoing phosphorylation released significantly lower levels of TNF-α. Inhibition of p38, a known kinase for TTP, by either siRNA or a small molecule inhibitor abrogated radiation-induced TNF-α release by MH-S cells. Lung irradiation induced TTP(Ser178 phosphorylation and protein degradation and a simultaneous increase in TNF-α production in C57BL/6 mice starting 24 h post-radiation. In conclusion, irradiation of lung macrophages causes TTP inactivation via p38-mediated phosphorylation and proteasome-mediated degradation, leading to TNF-α production. These findings suggest that agents capable of blocking TTP phosphorylation or stabilizing TTP after irradiation could decrease RILT.

  6. Radiation-induced bystander effects: Are they good bad or both?

    International Nuclear Information System (INIS)

    The different contributions are as follow: the current events on the cellular responses to irradiation ( part one and two); From physico-chemistry to radiobiology: new knowledge (part one and two); Radiation-induced bystander effects: are they good bad or both; recognition of the multi visceral failure in the acute irradiation syndrome; integrated approach of the tissue carcinogenesis: differential effect sane tissue-tumoral tissue; differential diagnosis of thyroid cancers by the transcriptoma analysis. (N.C.)

  7. The Protective Effect of Amifostine on Radiation-Induced Proctitis: Systemic Versus Topical Application

    OpenAIRE

    Cem Uzal; Atakan Sezer; Ufuk Usta; Necdet Süt; Alaattin Özen; Mehmet Ali Yağcı

    2012-01-01

    Objective: The aim of the study was to evaluate the radioprotective efficacy of intrarectal administration of amifostine in radiation-induced proctitis compared to intraperitoneal administration.Materials and Methods: Thirty-two Sprague-Dawley rats were randomly divided into four groups: Control (CONT), irradiation alone (RT), intraperitoneal amifostine plus irradiation (IPAMI), and intrarectal amifostine plus irradiation (IRAMI). The rats in the RT, IPAMI and IRAMI groups were irradiated ind...

  8. The Protective Effect of Amifostine on Radiation-Induced Proctitis: Systemic Versus Topical Application

    OpenAIRE

    UZAL, Cem; ALAS, Ruşen Coşar; USTA, UFUK; Süt, Necdet; ÖZEN, Alaattin; Yağcı, Mehmet Ali

    2012-01-01

    Objective: The aim of the study was to evaluate the radioprotective efficacy of intrarectal administration of amifostine in radiation-induced proctitis compared to intraperitoneal administration. Materials and Methods: Thirty-two Sprague-Dawley rats were randomly divided into four groups: Control (CONT), irradiation alone (RT), intraperitoneal amifostine plus irradiation (IPAMI), and intrarectal amifostine plus irradiation (IRAMI). The rats in the RT, IPAMI and IRAMI groups were irr...

  9. Cytoprotective Efficacy of Amifostine Against Radiation- Induced Rectal Toxicity: Objective and Subjective Grading Scales for Radiomucositis

    OpenAIRE

    John R. Kouvaris; Kouloulias, Vassilis E.

    2008-01-01

    Curative radiation therapy of pelvic malignancies, frequently results in doselimitingtoxicities such as serous, mucoid, or more rarely, bloody diarrhea. Several studieshave evaluated the cytoprotective effects of amifostine in preventing rectal mucositisassociated with radiation treatment. We searched Medline for published comparativestudies that evaluated the use of amifostine to reduce radiation-induced toxicity associatedwith pelvic irradiation. In ten studies there was an evidence-based c...

  10. Prevention of radiation-induced liver and kiney toxicity: a role for amifostine

    OpenAIRE

    KALDIR, Mine Uğuzalp; Çaloğlu, Vuslat Yürüt; ALAS, Ruşen Coşar; ÇERMİK, Tevfik Fikret; Altaner, Şemsi; ESKİOCAK, Sevgi; Saynak, Mert; TOKATLI, Füsun; KOÇAK, Zafer; UZAL, Cem

    2007-01-01

    OBJECTIVES To investigate the protective effect of amifostine against radiation induced liver and kidney injury of rats, using scintigraphic and histopathologic parameters. METHODS Female Wistar Albino rats were randomly allocated to 3 groups: control, radiotherapy alone (RT), and amifostine+RT (n=10). Single-dose of 600 cGy X-ray was performed with a single field compromised liver and right kidney. Amifostine was administered intraperitoneally at a dose of 400 mg/kg, 30 minutes before irrad...

  11. Selenoprotein P Inhibits Radiation-Induced Late Reactive Oxygen Species Accumulation and Normal Cell Injury

    Energy Technology Data Exchange (ETDEWEB)

    Eckers, Jaimee C.; Kalen, Amanda L.; Xiao, Wusheng; Sarsour, Ehab H.; Goswami, Prabhat C., E-mail: prabhat-goswami@uiowa.edu

    2013-11-01

    Purpose: Radiation is a common mode of cancer therapy whose outcome is often limited because of normal tissue toxicity. We have shown previously that the accumulation of radiation-induced late reactive oxygen species (ROS) precedes cell death, suggesting that metabolic oxidative stress could regulate cellular radiation response. The purpose of this study was to investigate whether selenoprotein P (SEPP1), a major supplier of selenium to tissues and an antioxidant, regulates late ROS accumulation and toxicity in irradiated normal human fibroblasts (NHFs). Methods and Materials: Flow cytometry analysis of cell viability, cell cycle phase distribution, and dihydroethidium oxidation, along with clonogenic assays, were used to measure oxidative stress and toxicity. Human antioxidant mechanisms array and quantitative real-time polymerase chain reaction assays were used to measure gene expression during late ROS accumulation in irradiated NHFs. Sodium selenite addition and SEPP1 overexpression were used to determine the causality of SEPP1 regulating late ROS accumulation and toxicity in irradiated NHFs. Results: Irradiated NHFs showed late ROS accumulation (4.5-fold increase from control; P<.05) that occurs after activation of the cell cycle checkpoint pathways and precedes cell death. The mRNA levels of CuZn- and Mn-superoxide dismutase, catalase, peroxiredoxin 3, and thioredoxin reductase 1 increased approximately 2- to 3-fold, whereas mRNA levels of cold shock domain containing E1 and SEPP1 increased more than 6-fold (P<.05). The addition of sodium selenite before the radiation treatment suppressed toxicity (45%; P<.05). SEPP1 overexpression suppressed radiation-induced late ROS accumulation (35%; P<.05) and protected NHFs from radiation-induced toxicity (58%; P<.05). Conclusion: SEPP1 mitigates radiation-induced late ROS accumulation and normal cell injury.

  12. Radiation-induced breast cancer: the question of early breast cancer screening in Hodgkin's lymphoma survivors

    OpenAIRE

    Hilal, Talal; Rudy, David W.

    2016-01-01

    Chest irradiation is associated with numerous early and late complications that arise from ionizing radiation-induced damage to cellular structures within the field of therapy. In patients exposed to chest irradiation at an early age as part of the treatment of childhood cancer, specifically Hodgkin's lymphoma, the increased risk of breast cancer in the long run should be considered. A case of a 35-year-old woman who exposed to chest irradiation as part of the treatment of Hodgkin's lymphoma ...

  13. Spontaneous and radiation induced cell death in HeLa S3 human carcinoma

    International Nuclear Information System (INIS)

    Radiation biologists have classified radiation-induced cell death based on cell proliferative capacity to either mitotic or interphase death. Cytologists have revealed two morphologically and biochemically diverse forms of cell death, apoptosis and necrosis. While the knowledge of the former is already well exploited by radiologists, cell susceptibility to apoptosis and necrosis is still under investigation. We studied characteristics of spontaneous cell death, and dose dependence and time course of radiation-induced cell death of human uterine cervix epitheloid carcinoma HeLaS3 in culture. Cells were irradiated with 2-40 Gy of γ-rays. The effect on growth, viability, morphology and genomic DNA structure were followed 24-72 h after irradiation. Cell viability was evaluated by trypan-blue exclusion assay and cell morphology by in situ DNA staining with propidium iodide. Cell genomic DNA fragmentation pattern was determined by electrophoresis on 2% agarose gels. At all cell densities 25-35% cells were PI positive and their DNA was fragmented to a high molecular size (≥20 kbp), but the internucleosomal ladder was not observed. A significant decrease in viability to 33% was observed 72 h post 40 Gy irradiation. It corresponded to 55% of PI positive cells. A smear of smaller DNA fragments (0.1-1 kbp), 24 h after 10-20 Gy irradiation was considered as proof that the dominant form of radiation-induced cell death was necrosis. It was concluded that the dominant form of radiation-induced cell death in HeLaS3 population was necrosis and the radiation dose which caused 50% of cell death after 72 h (termed ND50) was between 30-40 Gy. (author)

  14. Radiation-induced meningioma in children: report of two cases and review of the literature

    International Nuclear Information System (INIS)

    Meningioma developed in two children who had received high-dose cranial radiation for malignant brain tumors. Meningioma as a radiation-induced neoplasm has received little notice in the radiologic literature. Thirty-three cases have been reported since 1953, primarily in the neurosurgical literature. The current cases differ from those previously reported in having a much shorter latency period between irradiation and the development of meningioma. (orig.)

  15. The role' of Fas/FasL in radiation induced apoptosis in vivo

    International Nuclear Information System (INIS)

    The interaction of the Fas: Fas ligand has been recognized to play an important role in radiation-induced apoptosis. The purpose of this study was to investigate the role of Fas and Fas ligand mutations, in radiation-induced apoptosis in vivo. Mice with a mutation in the Fas (C57BL6J-Faslpr) and its normal control (C57BU 6J) and the Fas ligand (C3H/HeJ-FasgId) and its normal control (C3H/HeJ), were used in this study. Eight-week old male mice were given whole body radiation. After irradiation, the mice were killed at various time intervals, and their spleens collected. Tissue sample was stained with hematoxylin-eosin, and the numbers of apoptotic cells scored. The regulating molecules of apoptosis including the p53, Bcl-2, Bax, Bcl-XL and Bcl-Xs genes were also analyzed by Western blotting. With 2.5 Gy and 10 Gy of irradiation, the levels of apoptosis were lower in the C57BL/6J-Faslpr and C3H/HeJ-Fasgld mice than in the control mice (p lpr or C3H/HeJ-Fasgld mice. The p53, Bcl-XL, Bcl-Xs and Bcl-2 showed no significant changes in the C57BL/6J-Faslpr, C3H/HeJ-Fasgld, C57BL/6J and C3H/HeJ mice. The levels of radiation-induced apoptosis were lower in the /pr and gld, than the control mice, which seemed to be related to the level of Bax activation due to the radiation in the /pr and gld mice, This result suggests that Fas/Fas L plays an important role in radiation-induced apoptosis in vivo

  16. Radiation-induced destruction peculiarities of hydroxyl containing amino acids in diluted aqueous solution

    International Nuclear Information System (INIS)

    Amino acids aqueous solution of alpha-alanine and beta-alanine, serine, threonine (concentration 5*10-4 M) were irradiated with dose rate 0.35 Gy/s in range 100-1100 Gy and analysed. Effectiveness of radiation-induced decomposition process depends on row of factors: concentration of amino acid aqueous solution, pH, oxygen presence and other acceptors

  17. The pathogenesis of radiation-induced lung cancer in the rat: Progress report

    International Nuclear Information System (INIS)

    To examine the pathogenesis of radiation-induced lung tumors following alpha irradiation, F344/N rats were exposed to aerosols of 239PuO2 and are being observed for 24 mo following exposure. Various histological and biochemical techniques are being combined in a serial sacrifice design study to examine the development of pulmonary neoplasia sequentially, from the earliest identifiable cellular alterations to the ultimate expression of neoplasms in the lung. (author)

  18. Vitamin D Deficiency Is Associated With the Severity of Radiation-Induced Proctitis in Cancer Patients

    International Nuclear Information System (INIS)

    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

  19. Consequences of PAI-1 specific deletion in endothelium on radiation-induced intestinal damage

    International Nuclear Information System (INIS)

    Radiation-induced injury to healthy tissues is a real public health problem, since they are one of the most limiting factors that restrict efficiency of radiation therapy. This problematic is also part of the French Cancer Plan 2014-2017, and involves clinical research. Concepts surrounding the development of radiation-induced damage have gradually evolved into a contemporary and integrated view of the pathogenesis, involving all compartments of target tissue. Among them, endothelium seems to be central in the sequence of interrelated events that lead to the development of radiation-induced damage, although there are rare concrete elements that support this concept. By using new transgenic mouse models, this PhD project provides a direct demonstration of an endothelium-dependent continuum in evolution of radiation-induced intestinal damage. Indeed, changes in the endothelial phenotype through targeted deletion of the gene SERPINE1, chosen because of its key role in the development of radiation enteritis, influences various parameters of the development of the disease. Thus, lack of PAI-1 secretion by endothelial cells significantly improves survival of the animals, and limits severity of early and late tissue damage after a localized small bowel irradiation. Furthermore, these mice partially KO for PAI-1 showed a decrease in the number of apoptotic intestinal stem cells in the hours following irradiation, a decrease in the macrophages infiltrate density one week after irradiation, and a change in the polarization of macrophages throughout the pathophysiological process. In an effort to protect healthy tissues from radiation therapy side effects, without hindering the cancer treatment, PAI-1 seems to be an obvious therapeutic target. Conceptually, this work represents the direct demonstration of the link between endothelium phenotype and radiation enteritis pathogenesis. (author)

  20. Serum amyloid P ameliorates radiation-induced oral mucositis and fibrosis

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    Murray Lynne A

    2010-07-01

    Full Text Available Abstract Purpose To evaluate the effect of the anti-fibrotic protein serum amyloid P (SAP on radiation-induced oral mucositis (OM and fibrosis in a hamster cheek-pouch model. Experimental Design Hamsters received a single dose of radiation (40 Gy to the left everted cheek pouch to induce significant OM. The protective therapeutic potential of SAP was evaluated using varying dosing regimens. The extent of OM was measured using a validated six-point scoring scheme ranging from 0 (normal tissue, no mucositis to 5 (complete ulceration. Fibrotic remodeling was also visualized histologically and quantified at later time points using collagen gene expression. Results SAP treatment attenuated the profile of radiation-induced oral mucositis by delaying the time of onset, reducing the peak value, and enhancing the resolution of injury. The peak mucositis score was reduced by approximately 0.5 grade in SAP-treated animals. The number of animal days with a score of ≥ 3 was reduced by 48% in the SAP-treated group, compared with the saline control group (P Conclusions SAP treatment significantly attenuated radiation-induced injury. In particular, SAP attenuated the severity of OM and inhibited pathogenic remodeling. This suggests that SAP may be a useful therapy for the palliation of side effects observed during treatment for head and neck cancer.

  1. Modulation of radiation-induced hepato and pulmonary toxicity by pentoxiphyllin in rats

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the role of pentoxiphylline in modulating the deleterious effects of radiation induced liver and lung injuries. Mature female albino rats were categorized in the following groups: Normal control rats, pentoxifylline treated group for eight days, pentoxifylline treated group for 16 days, irradiated group exposed to fractionated 4 Gy at 2 Gy instalments, irradiated group exposed to fractionated 8 Gy at 2 Gy instalments, irradiated at fractionated dose (4 Gy) and treated with peritoxiphylline for 8 days, irradiated at fractionated dose (8 Gy) and treated with pentoxiphylline for 16 days. Examination of the liver showed that pentoxiphylline treatment has significantly improved the radiation-induced inflammation, dilatation and congestion of hepatic portal vein, atrophy and degenerative changes of hepatocytes, fibrosis of wall of bile ductules, decrease in PAS +ve material and increase in fibrous tissue. While, experimental investigations performed on the lung showed that treatment with pentoxiphylline had minimally improved the radiation-induced injury in lung tissue manifested by reduction of alveolar sacs, arteritis, fibrosis around bronchioles, emphysema, plethora, rupture of walls of bronchioles and arteries, thickening of alveolar septae, decrease in PAS +ve material and increase in fibrous tissue. The study showed that pentoxiphylline exerts a beneficial radio-modulative effect in liver but exerts a minimal radio modulator effect in lung following gamma irradiation in rats

  2. Loss of Matrix Metalloproteinase-13 Attenuates Murine Radiation-Induced Pulmonary Fibrosis

    International Nuclear Information System (INIS)

    Purpose: Pulmonary fibrosis is a disorder of the lungs with limited treatment options. Matrix metalloproteinases (MMPs) constitute a family of proteases that degrade extracellular matrix with roles in fibrosis. Here we studied the role of MMP13 in a radiation-induced lung fibrosis model using a MMP13 knockout mouse. Methods and Materials: We investigated the role of MMP13 in lung fibrosis by investigating the effects of MMP13 deficiency in C57Bl/6 mice after 20-Gy thoracic irradiation (6-MV Linac). The morphologic results in histology were correlated with qualitative and quantitative results of volume computed tomography (VCT), magnetic resonance imaging (MRI), and clinical outcome. Results: We found that MMP13 deficient mice developed less pulmonary fibrosis than their wildtype counterparts, showed attenuated acute pulmonary inflammation (days after irradiation), and a reduction of inflammation during the later fibrogenic phase (5-6 months after irradiation). The reduced fibrosis in MMP13 deficient mice was evident in histology with reduced thickening of alveolar septi and reduced remodeling of the lung architecture in good correlation with reduced features of lung fibrosis in qualitative and quantitative VCT and MRI studies. The partial resistance of MMP13-deficient mice to fibrosis was associated with a tendency towards a prolonged mouse survival. Conclusions: Our data indicate that MMP13 has a role in the development of radiation-induced pulmonary fibrosis. Further, our findings suggest that MMP13 constitutes a potential drug target to attenuate radiation-induced lung fibrosis.

  3. Expression of ICAM-1 in mice with radiation induced lung injury

    International Nuclear Information System (INIS)

    Objective: To observe the expression of intercellular adhesion molecule-1 (ICAM-1) in mice with radiation induced lung injury and to study the function of ICAM-1. Methods: The thoraces of C57BL/6 mice were exposed to either sham irradiation or single fraction of 12 Gy. Two groups were defined as received sham-irradiation (C group) and underwent irradiation (X group). Mice were sacrificed at hours 1, 24, 72 and weeks 1, 2, 4, 8, 16, 24 after irradiation. The lung tissues were removed and processed for definitive analysis, including HE and Masson staining, the hydroxyproline content, the immunohistochemistry and the real-time quantitative RT-PCR. Results: Compared with C group, there was a significant histological and pathologic change in X group. And there was a significantly elevated level of positive cell counts of ICAM-1 and inflammatory cells in X group (P<0.01). Similarly, there was a significantly elevated level of hydroxyproline in X group(P<0.05). Moreover, the results of real-time quantitative RT-PCR showed that the relative mRNA expression of cytokine ICAM-1 in X group was significantly higher than that of C group(P<0.01). Conclusions: As an important cytokine in radiation-induced lung injury, ICAM-1 can not only mediate the inflammation cells adherence and infiltration, but also be involved in radiation induced lung fibrosis. (authors)

  4. The effect of degree of deacetylation on the radiation induced degradation of chitosan

    International Nuclear Information System (INIS)

    Radiation-induced degradation of chitosan having different degree of deacetylation (DD) ratios was investigated. Chitosan samples were irradiated with gamma rays in air at ambient temperature in the solid state at a low dose rate. Change in their molecular weights was followed by size exclusion chromatography. Changes in their viscosity values as a function of dose, were also determined. Chains scission yields, G(S), and degradation rates were calculated. It was observed that the DD ratio was an important factor controlling the G(S) and degradation rate of chitosan. The change in the scission yield was attributed to the change in the crytallinity of the chitosan chains that was a result of a change in DD. - Highlights: • Radiation-induced degradation of chitosan described. • The influences of the DD on the radiation-induced degradation of chitosan were examined. • G(S) and degradation rate of chitosan were calculated by using molecular weights data obtained from size exclusion chromatography

  5. Radiation induced apoptosis and initial DNA damage are inversely related in locally advanced breast cancer patients

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    Rodriguez-Gallego Carlos

    2010-09-01

    Full Text Available Abstract Background DNA-damage assays, quantifying the initial number of DNA double-strand breaks induced by radiation, have been proposed as a predictive test for radiation-induced toxicity. Determination of radiation-induced apoptosis in peripheral blood lymphocytes by flow cytometry analysis has also been proposed as an approach for predicting normal tissue responses following radiotherapy. The aim of the present study was to explore the association between initial DNA damage, estimated by the number of double-strand breaks induced by a given radiation dose, and the radio-induced apoptosis rates observed. Methods Peripheral blood lymphocytes were taken from 26 consecutive patients with locally advanced breast carcinoma. Radiosensitivity of lymphocytes was quantified as the initial number of DNA double-strand breaks induced per Gy and per DNA unit (200 Mbp. Radio-induced apoptosis at 1, 2 and 8 Gy was measured by flow cytometry using annexin V/propidium iodide. Results Radiation-induced apoptosis increased in order to radiation dose and data fitted to a semi logarithmic mathematical model. A positive correlation was found among radio-induced apoptosis values at different radiation doses: 1, 2 and 8 Gy (p Conclusions An inverse association was observed for the first time between these variables, both considered as predictive factors to radiation toxicity.

  6. Effects of NOX1 on fibroblastic changes of endothelial cells in radiation-induced pulmonary fibrosis

    Science.gov (United States)

    CHOI, SEO-HYUN; KIM, MISEON; LEE, HAE-JUNE; KIM, EUN-HO; KIM, CHUN-HO; LEE, YOON-JIN

    2016-01-01

    Lung fibrosis is a major complication in radiation-induced lung damage following thoracic radiotherapy, while the underlying mechanism has remained to be elucidated. The present study performed immunofluorescence and immunoblot assays on irradiated human pulmonary artery endothelial cells (HPAECs) with or without pre-treatment with VAS2870, a novel NADPH oxidase (NOX) inhibitor, or small hairpin (sh)RNA against NOX1, -2 or -4. VAS2870 reduced the cellular reactive oxygen species content induced by 5 Gy radiation in HPAECs and inhibited phenotypic changes in fibrotic cells, including increased alpha smooth muscle actin and vimentin, and decreased CD31 and vascular endothelial cadherin expression. These fibrotic changes were significantly inhibited by treatment with NOX1 shRNA, but not by NOX2 or NOX4 shRNA. Next, the role of NOX1 in pulmonary fibrosis development was assessed in the lung tissues of C57BL/6J mice following thoracic irradiation using trichrome staining. Administration of an NOX1-specific inhibitor suppressed radiation-induced collagen deposition and fibroblastic changes in the endothelial cells (ECs) of these mice. The results suggested that radiation-induced pulmonary fibrosis may be efficiently reduced by specific inhibition of NOX1, an effect mediated by reduction of fibrotic changes of ECs. PMID:27053172

  7. The role of secretory granules in radiation-induced dysfunction of rat salivary glands

    Energy Technology Data Exchange (ETDEWEB)

    Peter, B.; Van Waarde, M.A.W.H.; Konings, A.W.T. [Univ. of Groningen (Netherlands); Vissink, A. [Univ. of Groningen (Netherlands)]|[Univ. Hospital, Groningen (Netherlands); `s-Gravenmade, E.J. [Univ. Hospital, Groningen (Netherlands)

    1995-02-01

    To investigate the possible role of secretory granules in radiation-induced salivary gland dysfunction, rats were pretreated with isoproterenol (5 mg/kg intraperitoneally) to degranulate salivary gland acini. At maximal depletion, salivary glands were locally irradiated with a single dose of 15 Gy of X rays. Parotid and submandibular/sublingual saliva samples were collected before and 1-10 days after irradiation. The lag phase, flow rate, concentrations of potassium and sodium, and amylase secretion were determined. Sham-treated, isoproterenol-treated and irradiated animals provided reference data. In the parotid gland, but not in the submandibular gland, protection against radiation-induced changes in flow rate and composition of saliva occurred after pretreatment with isoproterenol. Combining morphological data from a previous study with data from the current study, it is suggested that improvement of parotid gland function is attributed predominantly to a proliferative stimulus on acinar cells by isoproterenol and not to its degranulation effect. After pretreatment with isoproterenol, an earlier expression of radiation-induced acinar cell damage leading to death was observed, followed by a faster tissue recovery. Thus the proliferative stimulus on acinar cells may accelerate the unmasking of latent lethal damage, resulting in the earlier replacement of dead cells by new, functionally intact cells. 33 refs., 2 figs.

  8. Radiation-induced off-state leakage current in commercial power MOSFETs

    International Nuclear Information System (INIS)

    The total dose hardness of several commercial power MOSFET technologies is examined. After exposure to 20 krad(SiO2) most of the n- and p-channel devices examined in this work show substantial (2 to 6 orders of magnitude) increases in off-state leakage current. For the n-channel devices, the increase in radiation-induced leakage current follows standard behavior for moderately thick gate oxides, i.e., the increase in leakage current is dominated by large negative threshold voltage shifts, which cause the transistor to be partially on even when no bias is applied to the gate electrode. N-channel devices biased during irradiation show a significantly larger leakage current increase than grounded devices. The increase in leakage current for the p-channel devices, however, was unexpected. For the p-channel devices, it is shown using electrical characterization and simulation that the radiation-induced leakage current increase is related to an increase in the reverse bias leakage characteristics of the gated diode which is formed by the drain epitaxial layer and the body. This mechanism does not significantly contribute to radiation-induced leakage current in typical p-channel MOS transistors. The p-channel leakage current increase is nearly identical for both biased and grounded irradiations and therefore has serious implications for long duration missions since even devices which are usually powered off could show significant degradation and potentially fail.

  9. Effect of top electrode material on radiation-induced degradation of ferroelectric thin film structures

    Science.gov (United States)

    Brewer, Steven J.; Deng, Carmen Z.; Callaway, Connor P.; Paul, McKinley K.; Fisher, Kenzie J.; Guerrier, Jonathon E.; Rudy, Ryan Q.; Polcawich, Ronald G.; Jones, Jacob L.; Glaser, Evan R.; Cress, Cory D.; Bassiri-Gharb, Nazanin

    2016-07-01

    The effects of gamma irradiation on the dielectric and piezoelectric responses of Pb[Zr0.52Ti0.48]O3 (PZT) thin film stacks were investigated for structures with conductive oxide (IrO2) and metallic (Pt) top electrodes. The samples showed, generally, degradation of various key dielectric, ferroelectric, and electromechanical responses when exposed to 2.5 Mrad (Si) 60Co gamma radiation. However, the low-field, relative dielectric permittivity, ɛr, remained largely unaffected by irradiation in samples with both types of electrodes. Samples with Pt top electrodes showed substantial degradation of the remanent polarization and overall piezoelectric response, as well as pinching of the polarization hysteresis curves and creation of multiple peaks in the permittivity-electric field curves post irradiation. The samples with oxide electrodes, however, were largely impervious to the same radiation dose, with less than 5% change in any of the functional characteristics. The results suggest a radiation-induced change in the defect population or defect energy in PZT with metallic top electrodes, which substantially affects motion of internal interfaces such as domain walls. Additionally, the differences observed for stacks with different electrode materials implicate the ferroelectric-electrode interface as either the predominant source of radiation-induced effects (Pt electrodes) or the site of healing for radiation-induced defects (IrO2 electrodes).

  10. Radiation induced oral mucositis: a review of current literature on prevention and management.

    Science.gov (United States)

    Mallick, Supriya; Benson, Rony; Rath, G K

    2016-09-01

    Oral mucositis (OM) is a major limiting acute side effect of radiotherapy for head and neck cancer. The spectrum of problems associated with mucositis includes oral pain, odynophagia, reduced oral intake, and secondary infections. Incidence of mucositis is increased with addition of concurrent chemotherapy as well as altered fractionation schedules. This leads to treatment interruption and suboptimal disease control. Hence, prevention as well as timely management of OM is necessary for optimum tumor control. We reviewed the English literature with key words "Radiation induced mucositis, Mucositis, Oral Mucositis" to find relevant articles describing incidence, pathophysiology, prophylaxis, and treatment of oral mucositis. Prevention and treatment of OM is an active area of research. Maintenance of oral hygiene is an important part in prevention of OM. A battery of agents including normal saline and alkali (soda bicarbonate) mouth washes, low level laser therapy, and benzydamine (non-steroidal analgesic and anti-inflammatory) have effectiveness in the prevention and treatment of radiation induced oral mucositis. Chlorhexidine mouth gargles are recommended for prevention of chemotherapy induced oral mucositis but is not recommended for radiotherapy associated mucositis. Treatment of co-existing infection is also important and both topical (povidone iodine) and systemic anti fungals should be used judiciously. Radiation induced oral mucositis is a common problem limiting the efficacy of radiation by increasing treatment breaks. Adequate prophylaxis and treatment may limit the severity of radiation mucositis and improve compliance to radiation which may translate in better disease control and survival. PMID:26116012

  11. Early administration of IL-6RA does not prevent radiation-induced lung injury in mice

    International Nuclear Information System (INIS)

    Radiation pneumonia and subsequent radiation lung fibrosis are major dose-limiting complications for patients undergoing thoracic radiotherapy. Interleukin-6 (IL-6) is a pleiotropic cytokine and plays important roles in the regulation of immune response and inflammation. The purpose of this study was to investigate whether anti-IL-6 monoclonal receptor antibody (IL-6RA) could ameliorate radiation-induced lung injury in mice. BALB/cAnNCrj mice having received thoracic irradiation of 21 Gy were injected intraperitoneally with IL-6RA (MR16-1) or control rat IgG twice, immediately and seven days after irradiation. Enzyme-linked immunosorbent assay was used to examine the plasma level of IL-6 and serum amyloid A (SAA). Lung injury was assessed by histological staining with haematoxylin and eosin or Azan, measuring lung weight, and hydroxyproline. The mice treated with IL-6RA did not survive significantly longer than the rat IgG control. We observed marked up-regulation of IL-6 in mice treated with IL-6RA 150 days after irradiation, whereas IL-6RA temporarily suppressed early radiation-induced increase in the IL-6 release level. Histopathologic assessment showed no differences in lung section or lung weight between mice treated with IL-6RA and control. Our findings suggest that early treatment with IL-6RA after irradiation alone does not protect against radiation-induced lung injury

  12. Early administration of IL-6RA does not prevent radiation-induced lung injury in mice

    Directory of Open Access Journals (Sweden)

    Inoue Takehiro

    2010-04-01

    Full Text Available Abstract Background Radiation pneumonia and subsequent radiation lung fibrosis are major dose-limiting complications for patients undergoing thoracic radiotherapy. Interleukin-6 (IL-6 is a pleiotropic cytokine and plays important roles in the regulation of immune response and inflammation. The purpose of this study was to investigate whether anti-IL-6 monoclonal receptor antibody (IL-6RA could ameliorate radiation-induced lung injury in mice. Methods BALB/cAnNCrj mice having received thoracic irradiation of 21 Gy were injected intraperitoneally with IL-6RA (MR16-1 or control rat IgG twice, immediately and seven days after irradiation. Enzyme-linked immunosorbent assay was used to examine the plasma level of IL-6 and serum amyloid A (SAA. Lung injury was assessed by histological staining with haematoxylin and eosin or Azan, measuring lung weight, and hydroxyproline. Results The mice treated with IL-6RA did not survive significantly longer than the rat IgG control. We observed marked up-regulation of IL-6 in mice treated with IL-6RA 150 days after irradiation, whereas IL-6RA temporarily suppressed early radiation-induced increase in the IL-6 release level. Histopathologic assessment showed no differences in lung section or lung weight between mice treated with IL-6RA and control. Conclusions Our findings suggest that early treatment with IL-6RA after irradiation alone does not protect against radiation-induced lung injury.

  13. The effect of probiotics for preventing radiation-induced morphological changes in intestinal mucosa of rats.

    Science.gov (United States)

    Ki, Yongkan; Kim, Wontaek; Cho, Heunglae; Ahn, Kijung; Choi, Youngmin; Kim, Dongwon

    2014-10-01

    Radiation therapy is an important treatment modality for abdominal or pelvic cancer, but there is a common and serious complication such as radiation-induced enteritis. Probiotics is reported to have positive effects against radiation-induced enteropathy. In this study, morphological changes of bowel mucosa were analyzed in rats to presume the effect of probiotics on radiation-induced enteritis and its correlation with radiation dose. A total of 48 adult male Sprague-Dawley rats were randomly assigned to two groups and received a solution containing 1.0×10(8) colony-forming units of Lactiobacillus acidophilus or water once daily for 10 days. Each of two groups was divided into three subgroups and abdomino-pelvic area of each subgroup was irradiated with 10, 15, and 20 Gy, respectively on the seventh day of feeding the solutions. All rats were sacrificed 3 days after irradiation and the mucosal thickness and villus height of jejunum, ileum and colon were measured. The morphological parameters of the small intestine represented significant differences between two solution groups irradiated 10 or 15 Gy, except for villus height of jejunum in 15 Gy-subgroup (P=0.065). There was no significant morphometric difference between two groups irradiated with 20 Gy of radiation. Probiotics appear to be effective for the morphological shortening of small intestinal mucosa damaged by radiation less than or equal to 15 Gy. PMID:25368490

  14. Advances in dosimetry and biological predictors of radiation-induced esophagitis

    Science.gov (United States)

    Yu, Yang; Guan, Hui; Dong, Yuanli; Xing, Ligang; Li, Xiaolin

    2016-01-01

    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. PMID:26869804

  15. 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

  16. Simulation of nucleation kinetics of radiation-induced defect clusters in irradiated materials

    International Nuclear Information System (INIS)

    A numerical method for simulation kinetics of radiation-induced defect clusters in irradiated materials is developed. Calculations of nucleation kinetics of radiation-induced defect clusters under pulsed irradiation corresponding to continuous irradiation of the thermonuclear reactor first wall are carried out. It is shown that under pulsed irradiation the concentration of nucleated dislocation loops doesn't practically differ from the concentration of loops nucleated at the same doses under continuous irradiation. The average size of dislocation loops nucleated under cyclic irradiation (τ1=103 s, τ2=103 s) at radiation time τ=2x104 s is two times less than the average size of dislocation loops nucleated at the same time of continuous irradiation. Comparative analysis of nucleation kinetics of radiation-induced defect clusters is carried out for two models of linear dislocations: dislocations, being a ''continuous'' sink for point defects, and dislocations, being ''discrete'' sink for them. Account of microscopic processes occuring in dislocation nuclei (a model of ''discrete'' dislocation) is shown to lead to faster rates of nucleation and growth of dislocation loops, which values are similar to the values experimentally observed

  17. Leaf extract of Moringa oleifera prevents ionizing radiation-induced oxidative stress in mice.

    Science.gov (United States)

    Sinha, Mahuya; Das, Dipesh K; Bhattacharjee, Surajit; Majumdar, Subrata; Dey, Sanjit

    2011-10-01

    The present study evaluated the hepatoprotective effect of aqueous ethanolic Moringa oleifera leaf extract (MoLE) against radiation-induced oxidative stress, which is assessed in terms of inflammation and lipid peroxidation. Swiss albino mice were administered MoLE (300 mg/kg of body weight) for 15 consecutive days before exposing them to a single dose of 5 Gy of ⁶⁰Co γ-irradiation. Mice were sacrificed at 4 hours after irradiation. Liver was collected for immunoblotting and biochemical tests for the detection of markers of hepatic oxidative stress. Nuclear translocation of nuclear factor kappa B (NF-κB) and lipid peroxidation were augmented, whereas the superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), and ferric reducing antioxidant power (FRAP) values were decreased by radiation exposure. Translocation of NF-κB from cytoplasm to nucleus and lipid peroxidation were found to be inhibited, whereas increases in SOD, CAT, GSH, and FRAP were observed in the mice treated with MoLE prior to irradiation. Therefore pretreatment with MoLE protected against γ-radiation-induced liver damage. The protection may be attributed to the free radical scavenging activity of MoLE, through which it can ameliorate radiation-induced oxidative stress.

  18. Biological dosimetry: the potential use of radiation-induced apoptosis in human T-lymphocytes

    International Nuclear Information System (INIS)

    An assay for biological dosimetry based on the induction of apoptosis in human T-lymphocytes is described. Radiation-induced apoptosis was assessed by flow cytometric identification of cells displaying apoptosis-associated DNA condensation. CD4 and CD8 T-lymphocytes were analysed. They were recognized on the basis of their cell-surface antigens. Four parameters were measured for both cell types: cell size, granularity, antigen immunofluorescence and DNA content. Apoptosis was quantified as the fraction of CD4-, or CD8-positive cells with a characteristic reduction of cell size and DNA content. At doses below 1 Gy, levels of radiation-induced apoptosis increased for up to 5 days after irradiation. Optimal dose discrimination was observed 4 days after irradiation, at which time the dose-response curves were linear, with a slope of 8% ± 0.5% per 0.1 Gy. In controlled, dose-response experiments the lowest dose level at which the radiation-induced apoptosis frequency was still significantly above control was 0.05 Gy. After 5 days post-irradiation incubation, intra- and interdonor variations were measured and found to be similar; thus, apoptotic levels depend more on the dose than on the donor. The results demonstrate the potential of this assay as a biological dosimeter. (orig.)

  19. Lessons learned using different mouse models during space radiation-induced lung tumorigenesis experiments.

    Science.gov (United States)

    Wang, Jian; Zhang, Xiangming; Wang, Ping; Wang, Xiang; Farris, Alton B; Wang, Ya

    2016-06-01

    Unlike terrestrial ionizing radiation, space radiation, especially galactic cosmic rays (GCR), contains high energy charged (HZE) particles with high linear energy transfer (LET). Due to a lack of epidemiologic data for high-LET radiation exposure, it is highly uncertain how high the carcinogenesis risk is for astronauts following exposure to space radiation during space missions. Therefore, using mouse models is necessary to evaluate the risk of space radiation-induced tumorigenesis; however, which mouse model is better for these studies remains uncertain. Since lung tumorigenesis is the leading cause of cancer death among both men and women, and low-LET radiation exposure increases human lung carcinogenesis, evaluating space radiation-induced lung tumorigenesis is critical to enable safe Mars missions. Here, by comparing lung tumorigenesis obtained from different mouse strains, as well as miR-21 in lung tissue/tumors and serum, we believe that wild type mice with a low spontaneous tumorigenesis background are ideal for evaluating the risk of space radiation-induced lung tumorigenesis, and circulating miR-21 from such mice model might be used as a biomarker for predicting the risk.

  20. Lessons learned using different mouse models during space radiation-induced lung tumorigenesis experiments

    Science.gov (United States)

    Wang, Jian; Zhang, Xiangming; Wang, Ping; Wang, Xiang; Farris, Alton B.; Wang, Ya

    2016-06-01

    Unlike terrestrial ionizing radiation, space radiation, especially galactic cosmic rays (GCR), contains high energy charged (HZE) particles with high linear energy transfer (LET). Due to a lack of epidemiologic data for high-LET radiation exposure, it is highly uncertain how high the carcinogenesis risk is for astronauts following exposure to space radiation during space missions. Therefore, using mouse models is necessary to evaluate the risk of space radiation-induced tumorigenesis; however, which mouse model is better for these studies remains uncertain. Since lung tumorigenesis is the leading cause of cancer death among both men and women, and low-LET radiation exposure increases human lung carcinogenesis, evaluating space radiation-induced lung tumorigenesis is critical to enable safe Mars missions. Here, by comparing lung tumorigenesis obtained from different mouse strains, as well as miR-21 in lung tissue/tumors and serum, we believe that wild type mice with a low spontaneous tumorigenesis background are ideal for evaluating the risk of space radiation-induced lung tumorigenesis, and circulating miR-21 from such mice model might be used as a biomarker for predicting the risk.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-15

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

  2. GSN antibody pretreatment aggravates radiation-induced lung injury in mice

    International Nuclear Information System (INIS)

    Radiation-induced lung injury is one of the main dose limiting factors for thoracic radiation therapy. Gelsolin (GSN) is a widespread, multifunctional regulator of cellular structure and metabolism. In this work, the roles of GSN in radiation-induced lung injury in Balb/c mice were studied. The GSN levels in plasma reduced progressively in 72 hours after irradiation, and then increased gradually. GSN contents in the bronchoalveolar lavage (BAL) fluid increased after thoracic irradiation, whereas mRNA levels of GSN in the lung tissue decreased significantly within 24 hours after irradiation and then increased again. Mice were intravenously injected with 50 μg GSN antibody 0.5 hour before 20 Gy of thoracic irradiation. GSN antibody pretreatment increased lung inflammation, protein concentration in the BAL fluid and leukocytes infiltration in the irradiated mice. The activities of superoxidase dismutase (SOD) in the plasma and the BAL fluid in irradiated mice injected with GSN antibody were less than that of control groups, whereas the levels of malondialdehyde (MDA) increased. These results suggest that pretreatment of GSN antibody may aggravate radiation-induced pneumonitis. (authors)

  3. Combined inhibition of TGFβ and PDGF signaling attenuates radiation-induced pulmonary fibrosis

    Science.gov (United States)

    Dadrich, Monika; Nicolay, Nils H.; Flechsig, Paul; Bickelhaupt, Sebastian; Hoeltgen, Line; Roeder, Falk; Hauser, Kai; Tietz, Alexandra; Jenne, Jürgen; Lopez, Ramon; Roehrich, Manuel; Wirkner, Ute; Lahn, Michael; Huber, Peter E.

    2016-01-01

    ABSTRACT Background: Radiotherapy (RT) is a mainstay for the treatment of lung cancer, but the effective dose is often limited by the development of radiation-induced pneumonitis and pulmonary fibrosis. Transforming growth factor β (TGFβ) and platelet-derived growth factor (PDGF) play crucial roles in the development of these diseases, but the effects of dual growth factor inhibition on pulmonary fibrosis development remain unclear. Methods: C57BL/6 mice were treated with 20 Gy to the thorax to induce pulmonary fibrosis. PDGF receptor inhibitors SU9518 and SU14816 (imatinib) and TGFβ receptor inhibitor galunisertib were applied individually or in combinations after RT. Lung density and septal fibrosis were measured by high-resolution CT and MRI. Lung histology and gene expression analyses were performed and Osteopontin levels were studied. Results: Treatment with SU9518, SU14816 or galunisertib individually attenuated radiation-induced pulmonary inflammation and fibrosis and decreased radiological and histological signs of lung damage. Combining PDGF and TGFβ inhibitors showed to be feasible and safe in a mouse model, and dual inhibition significantly attenuated radiation-induced lung damage and extended mouse survival compared to blockage of either pathway alone. Gene expression analysis of irradiated lung tissue showed upregulation of PDGF and TGFβ-dependent signaling components by thoracic irradiation, and upregulation patterns show crosstalk between downstream mediators of the PDGF and TGFβ pathways. Conclusion: Combined small-molecule inhibition of PDGF and TGFβ signaling is a safe and effective treatment for radiation-induced pulmonary inflammation and fibrosis in mice and may offer a novel approach for treatment of fibrotic lung diseases in humans. Translational statement: RT is an effective treatment modality for cancer with limitations due to acute and chronic toxicities, where TGFβ and PDGF play a key role. Here, we show that a combined

  4. Regulatory mechanism of radiation-induced cancer cell death by the change of cell cycle

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Soo Jin; Jeong, Min Ho; Jang, Ji Yeon [College of Medicine, Donga Univ., Pusan (Korea, Republic of)

    2003-09-01

    In our previous study, we have shown the main cell death pattern induced by irradiation or protein tyrosine kinase (PTK) inhibitors in K562 human myelogenous leukemic cell line. Death of the cells treated with irradiation alone was characterized by mitotic catastrophe and typical radiation-induced apoptosis was accelerated by herbimycin A (HMA). Both types of cell death were inhibited by genistein. In this study, we investigated the effects of HMA and genistein on cell cycle regulation and its correlation with the alterations of radiation-induced cell death. K562 cells in exponential growth phase were used for this study. The cells were irradiated with 10 Gy using 6 MeV Linac (200-300 cGy/min). Immediately after irradiation, cells were treated with 250 nM of HMA or 25{mu}M of genistein. The distributions of cell cycle, the expressions of cell cycle-related protein, the activities of cyclin-dependent kinase, and the yield of senescence and differentiation were analyzed. X-irradiated cells were arrested in the G2 phase of the cell cycle but unlike the p53-positive cells, they were not able to sustain the cell cycle arrest. An accumulation of cells in G2 phase of first cell-cycle post-treatment and an increase of cyclin B1 were correlated with spontaneous, premature, chromosome condensation and mitotic catastrophe. HMA induced rapid G2 checkpoint abrogation and concomitant p53-independent G1 accumulation HMA-induced cell cycle modifications correlated with the increase of cdc2 kinase activity, the decrease of the expressions of cyclins E and A and of CDK2 kinase activity, and the enhancement of radiation-induced apoptosis. Genistein maintained cells that were arrested in the G2-phase, decreased the expressions of cyclin B1 and cdc25C and cdc2 kinase activity, increased the expression of p16, and sustained senescence and megakaryocytic differentiation. The effects of HMA and genistein on the radiation-induced cell death of K562 cells were closely related to the cell

  5. Computed tomographic findings of radiation-induced acute adrenal injury with associated radiation nephropathy: a case report

    International Nuclear Information System (INIS)

    Radiation nephropathy was first recognized in 1906. The kidney is a radiosensitive organ with a tolerance dose (5% complications in 5 years) of 20 Gray. The imaging findings of acute and chronic radiation induced renal injury are previously described. Radiation-induced adrenal injury, to our knowledge, has not been described in the literature. Unlike the kidneys and other upper abdominal organs, the adrenal glands are traditionally thought to be radio-resistant, protected from radiation-induced injury by proximity to adjacent organs and by the adrenal medulla which reportedly has increased radio-resistance. We present the computed tomographic imaging findings of a patient with acute radiation induced adrenal injury which resulted in adrenal insufficiency following radiotherapy of an adjacent thecal metastasis

  6. Forward current enhanced elimination of the radiation induced boron-oxygen complex in silicon n+-p diodes

    CERN Document Server

    Makarenko, L F; Yakushevich, H S; Moll, M; Pintilie, I

    2014-01-01

    Using forward current injection with densities in the range 15-30A/cm(2) we can effectively eliminate the radiation-induced boron-oxygen complex, which is the main compensating center in irradiated Si solar cells. It was found that for a given forward current density the elimination rate is decreasing with increasing irradiation dose. Additionally, some evidences have been obtained on the negative-U properties of the radiation-induced boron-oxygen complex.

  7. High-frequency detection of the formation and stabilization of a radiation-induced defect cluster in semiconductor structures

    Energy Technology Data Exchange (ETDEWEB)

    Puzanov, A. S.; Obolenskiy, S. V., E-mail: obolensk@rf.unn.ru; Kozlov, V. A.; Volkova, E. V.; Paveliev, D. G. [Lobachevsky Nizhny Novgorod State University (Russian Federation)

    2015-12-15

    The processes of the formation and stabilization of a radiation-induced defect cluster upon the arrival of a fast neutron to the space-charge region of a semiconductor diode are analyzed. The current pulse formed by secondary electrons is calculated and the spectrum of the signal generated by the diode (detector) under the action of an instantaneous neutron flux of the fission spectrum is determined. The possibility of experimental detection of the picosecond radiation-induced transition processes is discussed.

  8. Biographic radiation-induced defect formation as a method of red phosphorus activation in its reaction with arylalkenes

    International Nuclear Information System (INIS)

    Effect of preliminary irradiation on reaction ability of red phosphorus, prepared by radiation-induced polymerization of white phosphorus in benzene under 60Co radiation was studied. It was shown that red phosphorus containing radiation-induced defects of P-P-R type (R - fragments of benzene) in reactions with arylalkenes manifests a high reaction activity, which exceeds largely the reactive capability of industrially produced red phosphorus, and of white phosphorus in some cases

  9. Protection of DNA From Ionizing Radiation-Induced Lesions by Asiaticoside.

    Science.gov (United States)

    Joy, Jisha; Alarifi, Saud; Alsuhaibani, Entissar; Nair, Cherupally K Krishnan

    2015-01-01

    This study aims to investigate whether asiaticoside, a triterpene glycoside, can afford protection to DNA from alterations induced by gamma radiation under in vitro, ex vivo, and in vivo conditions. In vitro studies were done on plasmid pBR322 DNA, ex vivo studies were done on cellular DNA of human peripheral blood leukocytes, and in vivo investigations were conducted on cellular DNA of spleen and bone marrow cells of mice exposed to whole-body gamma radiation. The supercoiled form of the plasmid pBR322 DNA upon exposure to the radiation was converted into relaxed open circular form due to induction of strand breaks. Presence of asiaticoside along with the DNA during irradiation prevented the relaxation of the supercoiled form to the open circular form. When human peripheral blood leukocytes were exposed to gamma radiation, the cellular DNA suffered strand breaks as evidenced by the increased comet parameters in an alkaline comet assay. Asiaticoside, when present along with blood during irradiation ex vivo, prevented the strand breaks and the comet parameters were closer to that of the controls. Whole-body exposure of mice to gamma radiation resulted in a significant increase in comet parameters of DNA of bone marrow and spleen cells of mice as a result of radiation-induced strand breaks in DNA. Administration of asiaticoside prior to whole-body radiation exposure of the mice prevented this increase in radiation-induced increase in comet parameters, which could be the result of protection to DNA under in vivo conditions of radiation exposure. Thus, it can be concluded from the results that asiaticoside can offer protection to DNA from radiation-induced alterations under in vitro, ex vivo, and in vivo conditions.

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

    International Nuclear Information System (INIS)

    The use of radiation therapy has been linked to an increased risk of cardiovascular disease. To understand the mechanisms underlying radiation-induced vascular dysfunction, we employed two models. First, we examined the effect of X-ray irradiation on vasodilation in rabbit carotid arteries. Carotid arterial rings were irradiated with 8 or 16 Gy using in vivo and ex vivo methods. We measured the effect of acetylcholine-induced relaxation after phenylephrine-induced contraction on the rings. In irradiated carotid arteries, vasodilation was significantly attenuated by both irradiation methods. The relaxation response was completely blocked by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, a potent inhibitor of soluble guanylate cyclase. Residual relaxation persisted after treatment with L-Nω-nitroarginine (L-NA), a non-specific inhibitor of nitric oxide synthase (NOS), but disappeared following the addition of aminoguanidine (AG), a selective inhibitor of inducible NOS (iNOS). The relaxation response was also affected by tetraethylammonium, an inhibitor of endothelium-derived hyperpolarizing factor activity. In the second model, we investigated the biochemical events of nitrosative stress in human umbilical-vein endothelial cells (HUVECs). We measured iNOS and nitrotyrosine expression in HUVECs exposed to a dose of 4 Gy. The expression of iNOS and nitrotyrosine was greater in irradiated HUVECs than in untreated controls. Pretreatment with AG, L-N6-(1-iminoethyl) lysine hydrochloride (a selective inhibitor of iNOS), and L-NA attenuated nitrosative stress. While a selective target of radiation-induced vascular endothelial damage was not definitely determined, these results suggest that NO generated from iNOS could contribute to vasorelaxation. These studies highlight a potential role of iNOS inhibitors in ameliorating radiation-induced vascular endothelial damage. (author)

  11. An experimental study on prevention of radiation-induced lung damage

    International Nuclear Information System (INIS)

    Dextran sulphate (DS) has an inhibitory effect on platelet aggregation and fibrosis, as seen in various pathological conditions, both experimentally and clinically. DS also increases fibrinolytic activity in the blood. Described herein are the histopathologic changes seen in mice exposed to 2000R (18.8 Gy) or 4000 R (37.6 Gy) of 200 kv X ray to the right hemithorax and the effect of oral administration of DS on the pulmonary radiation-induced injury was investigated. A quantitative method employing lung hydroxyproline content was also done. The results obtaines are as follows. Mild edema in the alveolar spaces and interstitum and capillary thrombi, presumably due to direct endothelial damage of the blood vessels were the initial manifestations of the radiation-induced damage. In addition, there was an increase in leucocytes in the alveolar septa. Following these initial reactions, degeneration of Type II pneumocytes and increases in alveolar macrophages and/or foam cells in the alveolar lavage were evident. One month after the exposure to irradiation, degeneration of the bronchial epithelium became apparent. Three or 5 months after the irradiation, the lungs showed predominant fibrous changes and typical manifestations of radiation-induced injury. Higher doses of irradiation led to even more severe reactions. In the animals given higher doses, thrombosis was more severe and fibrous changes were present in the earlier experimental period. Oral administration of DS in doses of 0.83-8.3 mg/day decreased the formation of microthrombi. In the animals given 2000 R, frequency and severity of fibrous changes was lower in the DS-administered group than in the non-DS group. Hemorrhagic change within the lung was not enhanced when X-ray irradiation and oral DS were given in combination. (author)

  12. Folic acid deficiency increases chromosomal instability, chromosome 21 aneuploidy and sensitivity to radiation-induced micronuclei

    International Nuclear Information System (INIS)

    Folic acid deficiency can lead to uracil incorporation into DNA, hypomethylation of DNA, inefficient DNA repair and increase chromosome malsegregation and breakage. Because ionising radiation increases demand for efficient DNA repair and also causes chromosome breaks we hypothesised that folic acid deficiency may increase sensitivity to radiation-induced chromosome breakage. We tested this hypothesis by using the cytokinesis-block micronucleus assay in 10 day WIL2-NS cell cultures at four different folic acid concentrations (0.2, 2, 20, and 200 nM) that span the 'normal' physiological range in humans. The study showed a significant dose-dependent increase in frequency of binucleated cells with micronuclei and/or nucleoplasmic bridges with decreasing folic acid concentration (P < 0.0001, P = 0.028, respectively). These biomarkers of chromosomal instability were also increased in cells irradiated (1.5 Gy γ-rays) on day 9 relative to un-irradiated controls (P < 0.05). Folic acid deficiency and γ-irradiation were shown to have a significant interactive effect on frequency of cells containing micronuclei (two-way ANOVA, interaction P 0.0039) such that the frequency of radiation-induced micronucleated cells (i.e. after subtracting base-line frequency of un-irradiated controls) increased with decreasing folic acid concentration (P-trend < 0.0001). Aneuploidy of chromosome 21, apoptosis and necrosis were increased by folic acid deficiency but not by ionising radiation. The results of this study show that folate status has an important impact on chromosomal stability and is an important modifying factor of cellular sensitivity to radiation-induced genome damage

  13. Radiation-induced brain injury: low-hanging fruit for neuroregeneration.

    Science.gov (United States)

    Burns, Terry C; Awad, Ahmed J; Li, Matthew D; Grant, Gerald A

    2016-05-01

    Brain radiation is a fundamental tool in neurooncology to improve local tumor control, but it leads to profound and progressive impairments in cognitive function. Increased attention to quality of life in neurooncology has accelerated efforts to understand and ameliorate radiation-induced cognitive sequelae. Such progress has coincided with a new understanding of the role of CNS progenitor cell populations in normal cognition and in their potential utility for the treatment of neurological diseases. The irradiated brain exhibits a host of biochemical and cellular derangements, including loss of endogenous neurogenesis, demyelination, and ablation of endogenous oligodendrocyte progenitor cells. These changes, in combination with a state of chronic neuroinflammation, underlie impairments in memory, attention, executive function, and acquisition of motor and language skills. Animal models of radiation-induced brain injury have demonstrated a robust capacity of both neural stem cells and oligodendrocyte progenitor cells to restore cognitive function after brain irradiation, likely through a combination of cell replacement and trophic effects. Oligodendrocyte progenitor cells exhibit a remarkable capacity to migrate, integrate, and functionally remyelinate damaged white matter tracts in a variety of preclinical models. The authors here critically address the opportunities and challenges in translating regenerative cell therapies from rodents to humans. Although valiant attempts to translate neuroprotective therapies in recent decades have almost uniformly failed, the authors make the case that harnessing human radiation-induced brain injury as a scientific tool represents a unique opportunity to both successfully translate a neuroregenerative therapy and to acquire tools to facilitate future restorative therapies for human traumatic and degenerative diseases of the central nervous system. PMID:27132524

  14. Enhancing repair of radiation-induced strand breaks in cellular DNA as a radiotherapeutic potential

    International Nuclear Information System (INIS)

    Protection of mammalian organisms including man from deleterious effects of ionizing radiation is of paramount importance and development of effective approaches to combat radiation damages using non-toxic radioprotectors is of considerable interest for defence, nuclear industries, radiation accidents, space travels, etc., besides the protection of normal tissues during radiotherapy of tumours. Many synthetic as well as natural compounds have been investigated in the recent past for their efficacy to protect the biological systems from radiation induced damages. They include sulfhydryl compounds, antioxidants, plant extracts, immune-modulators, and other agents. However, the inherent toxicity of many of the synthetic agents at the effective radio-protective concentration warranted further search for safer and more effective radio-protectors. In this context, therapeutic radioprotectors which are effective on post irradiation administration are of special relevance. One of the property that can be applied while screening for such radiation protective therapeutics is their ability to enhance repair of radiation-induced lesions in cellular DNA in terms of cellular repair index based on the parameters of the DNA following comet assay. Post irradiation administration of some natural and synthetic agents have shown their potential to enhance repair of radiation-induced strand breaks in cellular DNA in mice. These include phytoceuticals such as gallic acid, sesamol etc., extracts of medicinal plants such as Andrographis panniculata, and a few synthetic compounds such as tocopherol-mono-glucoside. The talk will give an overview of the work on DNA repair enhancement by a few natural and synthetic agents. (author)

  15. Influence of age, sex and life style factors on the spontaneous and radiation induced micronuclei frequencies

    International Nuclear Information System (INIS)

    Several endpoints have been used for monitoring human populations for environmental or occupational exposure to genotoxic agents, particularly ionizing radiation. The cytokinesis-block micronucleus (MN) assay in peripheral lymphocytes is a reliable method for assessing radiation induced chromosomal damage (DNA breaks and mitotic spindle disturbances) and thus, a suitable dosimeter for estimating in vivo whole body exposures. To further define the use of this assay in biological dosimetry, a study to determine the influence of age, sex and life style factors (smoking habit) on the spontaneous and radiation induced MN frequencies was performed. The estimation of MN frequencies was analyzed in lymphocytes cultures from 50 healthy donors aged between 4 and 62 years. On the basis of their smoking habit they were divided into 2 groups. A fraction of the sample was irradiated in vitro with Y rays in the range of 0.35 Gy to 4 Gy. A statistically significant influence on the spontaneous MN frequency was observed (R2 = 0.59) when the variables age and smoking habit were analyzed and also a statistically significant influence on the radiation induced MN frequency was obtained (R2 = 0.96) when dose, age and smoking habit were studied. Sex did not influence MN variability significantly but there was a greater dispersion in the results for females when compared to males, possibly due to the loss of X chromosomes. The comparison of the data from smoking to non smoking donors supports the convenience to take into account the smoking habit for estimating in vivo whole body exposures to γ-rays for doses below 2 Gy. (author)

  16. Radiation-induced alterations of histone post-translational modification levels in lymphoblastoid cell lines

    International Nuclear Information System (INIS)

    Radiation-induced alterations in posttranslational histone modifications (PTMs) may affect the cellular response to radiation damage in the DNA. If not reverted appropriately, altered PTM patterns may cause long-term alterations in gene expression regulation and thus lead to cancer. It is therefore important to characterize radiation-induced alterations in PTM patterns and the factors affecting them. A lymphoblastoid cell line established from a normal donor was used to screen for alterations in methylation levels at H3K4, H3K9, H3K27, and H4K20, as well as acetylation at H3K9, H3K56, H4K5, and H4K16, by quantitative Western Blot analysis at 15 min, 1 h and 24 h after irradiation with 2 Gy and 10 Gy. The variability of alterations in acetylation marks was in addition investigated in a panel of lymphoblastoid cell lines with differing radiosensitivity established from lung cancer patients. The screening procedure demonstrated consistent hypomethylation at H3K4me3 and hypoacetylation at all acetylation marks tested. In the panel of lymphoblastoid cell lines, however, a high degree of inter-individual variability became apparent. Radiosensitive cell lines showed more pronounced and longer lasting H4K16 hypoacetylation than radioresistant lines, which correlates with higher levels of residual γ-H2AX foci after 24 h. So far, the factors affecting extent and duration of radiation-induced histone alterations are poorly defined. The present work hints at a high degree of inter-individual variability and a potential correlation of DNA damage repair capacity and alterations in PTM levels

  17. Radiation induced apoptosis and initial DNA damage are inversely related in locally advanced breast cancer patients

    International Nuclear Information System (INIS)

    DNA-damage assays, quantifying the initial number of DNA double-strand breaks induced by radiation, have been proposed as a predictive test for radiation-induced toxicity. Determination of radiation-induced apoptosis in peripheral blood lymphocytes by flow cytometry analysis has also been proposed as an approach for predicting normal tissue responses following radiotherapy. The aim of the present study was to explore the association between initial DNA damage, estimated by the number of double-strand breaks induced by a given radiation dose, and the radio-induced apoptosis rates observed. Peripheral blood lymphocytes were taken from 26 consecutive patients with locally advanced breast carcinoma. Radiosensitivity of lymphocytes was quantified as the initial number of DNA double-strand breaks induced per Gy and per DNA unit (200 Mbp). Radio-induced apoptosis at 1, 2 and 8 Gy was measured by flow cytometry using annexin V/propidium iodide. Radiation-induced apoptosis increased in order to radiation dose and data fitted to a semi logarithmic mathematical model. A positive correlation was found among radio-induced apoptosis values at different radiation doses: 1, 2 and 8 Gy (p < 0.0001 in all cases). Mean DSB/Gy/DNA unit obtained was 1.70 ± 0.83 (range 0.63-4.08; median, 1.46). A statistically significant inverse correlation was found between initial damage to DNA and radio-induced apoptosis at 1 Gy (p = 0.034). A trend toward 2 Gy (p = 0.057) and 8 Gy (p = 0.067) was observed after 24 hours of incubation. An inverse association was observed for the first time between these variables, both considered as predictive factors to radiation toxicity

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

    International Nuclear Information System (INIS)

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

  19. Development of radiation-inducible promoters for use in nitric oxide synthase gene therapy of cancer

    International Nuclear Information System (INIS)

    Full text: The free radical nitric oxide (NO) at nM concentrations performs multiple signaling roles that are essential for survival. These processes are regulated via the enzymes nNOS and eNOS, but another isoform, inducible nitric oxide synthase (iNOS) is capable of generating much higher concentrations (mM) over longer periods, resulting in the generation of very toxic species such as peroxynitrite. At high concentrations NO has many of the characteristics of an ideal anticancer molecule: it is cytotoxic (pro-apoptotic via peroxynitrite), it is a potent chemical radiosensitizer, it is anti-angiogenic and anti-metastatic. Thus, we see iNOS gene therapy as a strategy for targeting the generation of high concentrations of NO to tumours for therapeutic benefit. iNOS gene therapy should be used in combination with radiotherapy; so it is logical that the use of a radiation-inducible promoter should be part of the targeting strategy. We have tested several candidate promoters in vitro and in vivo. The WAF1 promoter has many of the properties desirable for therapeutic use including: rapid 3-4 fold induction at X-ray doses of 2 and 4Gy and no significant leakiness. WAF1 also has the advantage of being inducible by hypoxia and by the final product, NO. We have also tested the synthetic CArG promoter and demonstrated that, in addition to a high level of radiation inducibility, it is also inducible by NO. We have also been able to demonstrate potent radiosensitization (SER 2.0-2.5) in tumour cells in vitro and in vivo using iNOS gene transfer with constitutive or radiation-inducible promoters. We have also tested the use of iNOS gene therapy in combination with cisplatin and shown significant enhancement

  20. Radiation-induced lung damage in rats: The influence of fraction spacing on effect per fraction

    International Nuclear Information System (INIS)

    When the linear-quadratic model is used to predict fractionated treatments which are isoeffective, it is usually assumed that each (equal size) treatment fraction has an equal effect, independent of the time at which it was delivered during a course of treatment. Previous work has indicated that this assumption may not be valid in the context of radiation-induced lung damage in rats. Consequently the authors tested directly the validity of the assumption that each fraction has an equal effect, independent of the time it is delivered. An experiment was completed in which fractionated irradiation was given to whole thoraces of Sprague-Dawley rats. All treatment schedules consisted of eleven equal dose fractions in 36 days given as a split course, with some groups receiving the bulk of the doses early in the treatment schedule, before a 27-day gap, and others receiving most of the dose toward the end of the treatment schedule, after the time gap. To monitor the incidence of radiation-induced damage, breathing rate and lethality assays were used. The maximum differences in the LD50s and breathing rate ED50s for the different fractionation schedules were 4.0% and 7.7% respectively. The lethality data and breathing rate data were consistent with results expected from modelling using the linear-quadratic model with the inclusion of an overall time factor, but not the generalized linear-quadratic model which accounted for fraction spacing. For conventional daily fractionation, and within the range of experimental uncertainties, the results indicate that the effect of a treatment fraction does not depend on the time at which it is given (its position) in the treatment. The results indicate no need to extend isoeffect formulae to consider the effect of each fraction separately for radiation-induced lung damage. 21 refs., 6 figs., 3 tabs

  1. Summary of round robin measurements of radiation induced conductivity in Wesgo AL995 alumina

    Energy Technology Data Exchange (ETDEWEB)

    Zinkle, S.J. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    This existing data on radiation induced conductivity (RIC) measurements performed on the same heat of the IEA reference ceramic insulator are summarized. Six different sets of RIC measurements have been performed on Wesgo AL995 at dose rates between 10 Gy/s and 1 MGy/s. In general, good agreement was obtained between the different groups of researchers. The data indicate that the RIC at a test temperature of 400-500{degrees}C is approximately linear with ionizing dose rate up to {approximately}1000 Gy/s, and exhibits an approximately square root dependence on dose rate between 1 kGy/s and 1 MGy/s.

  2. Modification of radiation-induced oxidative damage in liposomal and microsomal membrane by eugenol

    Science.gov (United States)

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

    2006-03-01

    Radiation-induced membrane oxidative damage, and their modification by eugenol, a natural antioxidant, was investigated in liposomes and microsomes. Liposomes prepared with DPH showed decrease in fluorescence after γ-irradiation, which was prevented significantly by eugenol and correlated with magnitude of oxidation of phospholipids. Presence of eugenol resulted in substantial inhibition in MDA formation in irradiated liposomes/microsomes, which was less effective when added after irradiation. Similarly, the increase in phospholipase C activity observed after irradiation in microsomes was inhibited in samples pre-treated with eugenol. Results suggest association of radio- oxidative membrane damage with alterations in signaling molecules, and eugenol significantly prevented these membrane damaging events.

  3. Modification of radiation-induced oxidative damage in liposomal and microsomal membrane by eugenol

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, B.N. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Lathika, K.M. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Mishra, K.P. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)]. E-mail: kpm@magnum.barc.ernet.in

    2006-03-15

    Radiation-induced membrane oxidative damage, and their modification by eugenol, a natural antioxidant, was investigated in liposomes and microsomes. Liposomes prepared with DPH showed decrease in fluorescence after {gamma}-irradiation, which was prevented significantly by eugenol and correlated with magnitude of oxidation of phospholipids. Presence of eugenol resulted in substantial inhibition in MDA formation in irradiated liposomes/microsomes, which was less effective when added after irradiation. Similarly, the increase in phospholipase C activity observed after irradiation in microsomes was inhibited in samples pre-treated with eugenol. Results suggest association of radio- oxidative membrane damage with alterations in signaling molecules, and eugenol significantly prevented these membrane damaging events.

  4. Radiation-Induced Cataractogenesis: A Critical Literature Review for the Interventional Radiologist

    International Nuclear Information System (INIS)

    Extensive research supports an association between radiation exposure and cataractogenesis. New data suggests that radiation-induced cataracts may form stochastically, without a threshold and at low radiation doses. We first review data linking cataractogenesis with interventional work. We then analyze the lens dose typical of various procedures, factors modulating dose, and predicted annual dosages. We conclude by critically evaluating the literature describing techniques for lens protection, finding that leaded eyeglasses may offer inadequate protection and exploring the available data on alternative strategies for cataract prevention

  5. Ionizing radiation induced attachment reactions of nucleic acids and their components

    International Nuclear Information System (INIS)

    An extensive bibliographic review is given of experimental and theoretical data on radiation-induced attachment reactions of nucleic acids and their components. Mechanisms of these reactions are reviewed. The reactions with water, formate, and alcohols, with amines and other small molecules, and with radiation sensitizers and nucleic acid-nucleic acid reactions are discussed. Studies of the reaction mechanisms show that many of the reactions occur by radical-molecule reactions, but radical-radical reactions also occur. Radiation modifiers become attached to nucleic acids in vitro and in vivo and there are indications that attachment may be necessary for the action of some sensitizers. (U.S.)

  6. Finger reconstruction for the radiation-induced brachial plexus paralysis. A case report

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Ryuji; Ikuta, Yoshikazu; Ishida, Osamu; Takata, Haruhiko; Kimori, Kenji; Ochi, Mitsuo [Hiroshima Univ. (Japan). School of Medicine

    1996-01-01

    The patient is a 70-year-old woman. She received right mastectomy and irradiation (4000 rad) for breast cancer 17 years ago. She was referred with numbness of right fingers, muscle weakness and hypoaesthesia. X-ray photography revealed atrophy of the claviculus and the humerus and osteolysis. No recurrence or metastasis of the tumor was found on MRI and bone scintigraphy. She was diagnosed of radiation-induced brachial plexus paralysis. The finger reconstruction was performed and the function recovered. (H.O.)

  7. Radiation-induced meningiomas after BNCT in patients with malignant glioma.

    Science.gov (United States)

    Kageji, T; Sogabe, S; Mizobichi, Y; Nakajima, K; Shinji, N; Nakagawa, Y

    2015-12-01

    Of the 180 patients with malignant brain tumors whom we treated with boron neutron capture therapy (BNCT) since 1968, only one (0.56%) developed multiple radiation-induced meningiomas. The parasagittal meningioma that had received 42 Gy (w) for BNCT showed more rapid growth on Gd-enhanced MRI scans and more atypical features on histopathologic studies than the temporal convexity tumor that had received 20 Gy (w). Long-term follow up MRI studies are necessary in long-survivors of malignant brain tumors treated by BNCT. PMID:26122975

  8. [Radiation-induced changes in structural state of membranes of human blood cells].

    Science.gov (United States)

    Burlakova, E B; Atkarskaia, M V; Fatkullina, L D; Andreev, S G

    2014-01-01

    To evaluate radiation-induced changes in the structural state of the membranes, blood samples of healthy donors were subjected to gamma radiation in the range of small (1-10 cGy) and medium doses (50 cGy-2 Gy). After irradiation, the microviscosity of lipid membranes of red and white blood cells was measured by ESR spin probe method. At doses exceeding 1 cGy, statistically significant changes of the degree of spontaneous erythrocyte hemolysis and of the lymphocyte plasma membrane microviscosity were observed. Under identical irradiation conditions, the stability of lymphocyte membranes was less as compared to erythrocyte membranes.

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

    International Nuclear Information System (INIS)

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

  10. Dosimetric Predictors of Radiation-induced Acute Nausea and Vomiting in IMRT for Nasopharyngeal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Victor H.F., E-mail: vhflee@hku.hk [Department of Clinical Oncology, University of Hong Kong, Queen Mary Hospital (Hong Kong); Ng, Sherry C.Y.; Leung, T.W.; Au, Gordon K.H.; Kwong, Dora L.W. [Department of Clinical Oncology, University of Hong Kong, Queen Mary Hospital (Hong Kong)

    2012-09-01

    Purpose: We wanted to investigate dosimetric parameters that would predict radiation-induced acute nausea and vomiting in intensity-modulated radiation therapy (IMRT) for undifferentiated carcinoma of the nasopharynx (NPC). Methods and Materials: Forty-nine consecutive patients with newly diagnosed NPC were treated with IMRT alone in this prospective study. Patients receiving any form of chemotherapy were excluded. The dorsal vagal complex (DVC) as well as the left and right vestibules (VB-L and VB-R, respectively) were contoured on planning computed tomography images. A structure combining both the VB-L and the VB-R, named VB-T, was also generated. All structures were labeled organs at risk (OAR). A 3-mm three-dimensional margin was added to these structures and labeled DVC+3 mm, VB-L+3 mm, VB-R+3 mm, and VB-T+3 mm to account for physiological body motion and setup error. No weightings were given to these structures during optimization in treatment planning. Dosimetric parameters were recorded from dose-volume histograms. Statistical analysis of parameters' association with nausea and vomiting was performed using univariate and multivariate logistic regression. Results: Six patients (12.2%) reported Grade 1 nausea, and 8 patients (16.3%) reported Grade 2 nausea. Also, 4 patients (8.2%) complained of Grade 1 vomiting, and 4 patients (8.2%) experienced Grade 2 vomiting. No patients developed protracted nausea and vomiting after completion of IMRT. For radiation-induced acute nausea, V40 (percentage volume receiving at least 40Gy) to the VB-T and V40>=80% to the VB-T were predictors, using univariate analysis. On multivariate analysis, V40>=80% to the VB-T was the only predictor. There were no predictors of radiation-induced acute vomiting, as the number of events was too small for analysis. Conclusions: This is the first study demonstrating that a V40 to the VB-T is predictive of radiation-induced acute nausea. The vestibules should be labeled as sensitive OARs

  11. Radiation-induced defects in chalcogenide glasses characterized by combined optical spectroscopy, XPS and PALS methods

    Energy Technology Data Exchange (ETDEWEB)

    Shpotyuk, O. [Institute of Physics of Jan Dlugosz University, 13/15 al. Armii Krajowej, Czestochowa 42201 (Poland); Lehigh University, 5 East Packer Avenue, Bethlehem, PA 18015-3195 (United States); Lviv Institute of Materials of SRC ' ' Carat' ' , 202, Stryjska str., 79031 Lviv (Ukraine); Kovalskiy, A.; Jain, H. [Lehigh University, 5 East Packer Avenue, Bethlehem, PA 18015-3195 (United States); Golovchak, R. [Lehigh University, 5 East Packer Avenue, Bethlehem, PA 18015-3195 (United States); Lviv Institute of Materials of SRC ' ' Carat' ' , 202, Stryjska str., 79031 Lviv (Ukraine); Zurawska, A. [Opole University of Technology, 75, Ozimska str., Opole 45370 (Poland)

    2007-03-15

    Temperature-dependent optical absorption spectroscopy, high-resolution X-ray photoelectron spectroscopy and positron annihilation lifetimes spectroscopy are utilized to understand radiation-induced changes in Ge-Sb-S chalcogenide glasses. Theoretically predicted topological scheme of {gamma}-induced coordination defect formation in stoichiometric Ge{sub 23.5}Sb{sub 11.8}S{sub 64.7} glass composition is supported by these measurements. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. Radiation-induced defects formation in Bi-containing vitreous chalcogenides

    Energy Technology Data Exchange (ETDEWEB)

    Shpotyuk, O.; Vakiv, M.; Balitska, V.; Kovalskiy, A. [Institute of Materials, Lvov (Ukraine)

    1997-12-01

    Processes of formation and annihilation of coordination defects in As{sub 2}Se{sub 3}Bi{sub y} and (As{sub 2}Se{sub 3})(Bi{sub 2}Se{sub 3}){sub y} amorphous chalcogenide semiconductors induced by influence of Co{sup 60} gamma-irradiation are investigated by photoelectric spectroscopy method. It is obtained that radiation-induced changes of photoelectrical properties on bioconcentration of As{sub 2}Se{sub 3}Bi{sub y} glasses are characterized by anomalous concentration dependence. The nature of this effect is associated with diamagnetic coordination defects formation. (author). 19 refs, 3 figs.

  13. Transient radiation-induced absorption in materials for the DOI laser

    Science.gov (United States)

    Brannon, P. J.

    1994-11-01

    This is the final report on a series of experiments concerned with transient radiation-induced absorption in materials for a Cr,Nd:GSGG laser. Both the Sandia National Laboratories SPR III pulsed reactor and the Hermes III pulsed X-ray machine are used as radiation sources. The time dependence and the magnitude of the induced absorption in filter glasses and in doped and undoped LiNbO3 Q-switch materials have been measured. Gain has been observed in Cr,Nd:GSGG, the laser medium, when it is irradiated by X-rays.

  14. Transient radiation-induced absorption in materials for the DOI laser

    Energy Technology Data Exchange (ETDEWEB)

    Brannon, P.J.

    1995-01-01

    This is the final report on a series of experiments concerned with transient radiation-induced absorption in materials for a Cr,Nd:GSGG laser. Both the Sandia National Laboratories SPR III pulsed reactor and the Hermes III pulsed X-ray machine are used as radiation sources. The time dependence and the magnitude of the induced absorption in filter glasses and in doped and undoped LiNbO{sub 3} Q-switch materials have been measured. Gain has been observed in Cr,Nd:GSGG, the laser medium, when it is irradiated by X-rays.

  15. On the influence of dibenzyl-o-carborane on radiation-induced aging of polymethylmethacrylate

    International Nuclear Information System (INIS)

    Influence of dibenzyl-o-carborane additions in radiation resistance of polymethylmethacrylate (PMMA) subjected to gamma irradiation (60Co) by doses from 0 to 8.0 Mrad at dose rate of 0.7 Mrad/h was studied. It was ascertained that carborane manifests radioprotective properties during radiation-induced aging of PMMA prepared in its presence, it also inhibits thermal decomposition of the irradiated polymer. Influence of gamma radiation on PMMA, containing carborane additions as mechanical impurities, results in increase in the polymer thermal resistance, very likely at the expense of interaction between oxygen-containing groups of macromolecules and addition carborane fragments

  16. 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

  17. β-Arrestin-2 modulates radiation-induced intestinal crypt progenitor/stem cell injury.

    Science.gov (United States)

    Liu, Z; Tian, H; Jiang, J; Yang, Y; Tan, S; Lin, X; Liu, H; Wu, B

    2016-09-01

    Intestinal crypt progenitor/stem (ICPS) cell apoptosis and vascular endothelial cell apoptosis are responsible for the initiation and development of ionizing radiation (IR)-evoked gastrointestinal syndrome. The signaling mechanisms underlying IR-induced ICPS cell apoptosis remain largely unclear. Our findings provide evidence that β-arrestin-2 (βarr2)-mediated ICPS cell apoptosis is crucial for IR-stimulated intestinal injury. βArr2-deficient mice exhibited decreased ICPS cell and intestinal Lgr5(+) (leucine-rich repeat-containing G-protein-coupled receptor 5-positive) stem cell apoptosis, promoted crypt proliferation and reproduction, and protracted survival following lethal doses of radiation. Radioprotection in the ICPS cells isolated from βarr2-deficient mice depended on prolonged nuclear factor-κB (NF-κB) activation via direct interaction of βarr2 with IκBα and subsequent inhibition of p53-upregulated modulator of apoptosis (PUMA)-mediated mitochondrial dysfunction. Unexpectedly, βarr2 deficiency had little effect on IR-induced intestinal vascular endothelial cell apoptosis in mice. Consistently, βarr2 knockdown also provided significant radioresistance by manipulating NF-κB/PUMA signaling in Lgr5(+) cells in vitro. Collectively, these observations show that targeting the βarr2/NF-κB/PUMA novel pathway is a potential radiomitigator for limiting the damaging effect of radiotherapy on the gastrointestinal system. Significance statement: acute injury to the intestinal mucosa is a major dose-limiting complication of abdominal radiotherapy. The issue of whether the critical factor for the initiation of radiation-induced intestinal injury is intestinal stem cell apoptosis or endothelial cell apoptosis remains unresolved. βArrs have recently been found to be multifunctional adaptor of apoptosis. Here, we found that β-arrestin-2 (βarr2) deficiency was associated with decreased radiation-induced ICPS cell apoptosis, which prolonged survival in

  18. Hyperbaric oxygenation was effective in a case of radiation-induced optic neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Saitoh, Ayumi; Dake, Yoshinori; Amemiya, Tsugio [Nagasaki Univ. (Japan). School of Medicine

    1995-03-01

    A 68-year-old female underwent radiation treatment followed by surgical extirpation for olfactory neuroblastoma in the left ethmoidal sinus. Acute optic neuropathy developed 16 months later in her left eye. The visual acuity was reduced to finger counting at 30 cm. Treatment with systemic corticosteroid and hyperbaric oxygenation for 2 months resulted in improvement in fundus findings and improvement of visual acuity to 0.5. The findings show the potential effectiveness of hyperbaric oxygen therapy for radiation-induced optic neuropathy. (author).

  19. Effect of acoustic, deformation on radiation-induced luminescence of pyrolytic boron nitride

    CERN Document Server

    Kardashev, B K; Plaksin, O A; Stepanov, V A; Stepanov, P A; Chernov, V M

    2001-01-01

    The effect of the ultrasound oscillations with the frequency of approximately 100 kHz on the radiation-induced luminescence on the pyrolytic boron nitride, originating by the protons irradiation (the energy of 8 MeV, the flux of 1.6 x 10 sup 1 sup 2 p/cm s), is studied. The impact of the ultrasound oscillations manifests itself by high deformation amplitudes (approximately 10 sup - sup 4), when the nonlinear, amplitude-dependent ultrasound absorption is observed. The obtained data are explained by the change in the kinetics of recrystallization, induced by irradiation, whereby the disappearance (radiation annealing) of the small angle boundaries occurs

  20. The role' of Fas/FasL in radiation induced apoptosis in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Hee; Seong, Jin Sil [College of Medicine, Yonsei Univ., Seoul (Korea, Republic of)

    2003-09-01

    The interaction of the Fas: Fas ligand has been recognized to play an important role in radiation-induced apoptosis. The purpose of this study was to investigate the role of Fas and Fas ligand mutations, in radiation-induced apoptosis in vivo. Mice with a mutation in the Fas (C57BL6J-Fas{sup lpr}) and its normal control (C57BU 6J) and the Fas ligand (C3H/HeJ-Fas{sup gId}) and its normal control (C3H/HeJ), were used in this study. Eight-week old male mice were given whole body radiation. After irradiation, the mice were killed at various time intervals, and their spleens collected. Tissue sample was stained with hematoxylin-eosin, and the numbers of apoptotic cells scored. The regulating molecules of apoptosis including the p53, Bcl-2, Bax, Bcl-X{sup L} and Bcl-X{sup s} genes were also analyzed by Western blotting. With 2.5 Gy and 10 Gy of irradiation, the levels of apoptosis were lower in the C57BL/6J-Fas{sup lpr} and C3H/HeJ-Fas{sup gld} mice than in the control mice (p < 0.05). With the expression of apoptosis regulating molecules, the Bax was increased in both the C57BL/6J and C3H/HeJ mice in response to radiation; the peak levels of Bax in the C57BL/6J and C3H/HeJ were 3 and 3.3-fold higher after 8hr, respectively. However the Bax was not increased in either the C57BL/6J-Fas{sup lpr} or C3H/HeJ-Fas{sup gld} mice. The p53, Bcl-X{sup L}, Bcl-X{sub s} and Bcl-2 showed no significant changes in the C57BL/6J-Fas{sup lpr}, C3H/HeJ-Fas{sup gld}, C57BL/6J and C3H/HeJ mice. The levels of radiation-induced apoptosis were lower in the /pr and gld, than the control mice, which seemed to be related to the level of Bax activation due to the radiation in the /pr and gld mice, This result suggests that Fas/Fas L plays an important role in radiation-induced apoptosis in vivo.

  1. Mechanism of radiation-induced degradation of bisphenol-A polycarbonate

    OpenAIRE

    Rafael Navarro González; Roustam Aliev

    2001-01-01

    We report here a new approach to study the mechanism of radiation-induced degradation of polymeric materials based on the combined analysis of radiolytic gases, and pyrolytic products from preirradiated polymers by flash pyrolysis coupled to gas chromatography —Fourier transformed infrared spectroscopy— mass spectrometry with electron impact mode (GC-FTIR-MS). Bisphenol-A polycarbonate (PC) was studied in the dose range from 0.125 to 1.0 MGy. PC irradiation was accompanied by the preferential...

  2. Protective effect of zingerone, a dietary compound against radiation induced damage

    International Nuclear Information System (INIS)

    The radioprotective potential of phenolic alkanone, Zingerone (ZO) was investigated using human peripheral blood lymphocytes as well as Chinese hamster fibroblast (V79) cells growing in vitro and in vivo by using Swiss albino mice exposed to gamma radiation. In the in vivo studies, mice were administered with ZO (10-100 mg/kg b.wt), once daily for five consecutive days. One hour after the last administration of ZO on the fifth day, animals were whole body exposed to 10 Gy gamma radiations. The radioprotective potential was assessed using animal survival, haemopoietic stem cell survival (CFU) assay, mouse bone marrow micronucleus test, histological observations of intestinal and bone marrow damage. Effect of ZO pretreatment on radiation-induced changes in glutathione (GSH), glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT) and lipid peroxidation (LPx) levels was also analyzed. ZO treatment resulted increase in the LD50/30 by 1.8 Gy (dose reduction factor = 1.2). The number of spleen colonies after whole body irradiation of mice (4.5 or 7.5 Gy) was increased when ZO was administered 1 h prior to irradiation. The histological observations indicated a decline in the villus height and crypt number with an increase in goblet and dead cell population in the irradiated group, which was normalized by pretreatment with ZO. A significant (p < 0.001) reduction in micronucleated polychromatic, normochromatic erythrocytes, increased PCE/NCE ratio, increase in the GSH, GST, SOD, CAT and decreased LPx levels were observed in ZO by pretreated group when compared to the irradiated animals. Our in vitro and in vivo studies demonstrate the potential of ZO in mitigating radiation-induced cytotoxic, genotoxicity, apoptosis in cell culture and animal mortality, cytogenetic damage, intestinal and bone marrow protection in vivo. Radioprotective potential of ZO may be attributed to the inhibition radiation-induced decline in the endogenous antioxidant levels

  3. Protection of radiation-induced DNA damage in albino rats by Zingiber Montanum extract

    International Nuclear Information System (INIS)

    The tropical ginger, Zingiber montanum (J. König) A. Dietr, has potentials in scavenging free radicals and affording protection from radiation-induced chromosomal aberrations. The present investigation aims at determining antioxidant and radioprotective properties of the rhizome extract. Sulphur free radical, DPPH and superoxide scavenging assays were carried out for assessing antioxidant activities. Radiation-induced (500 cGy) DNA damage in pBR322 in vitro could be significantly reduced upto 71% (P < 0.05) by treatment with 60% ethanol extract (20 μg). Acute toxicity of the 60% ethanol extract was determined and suitable injectable dose was selected for intra-peritoneal administration in albino rats (Rattus norvegicus). The LD50 of extract calculated for 72 hrs was found to be 2.9 g/kg, and maximum tolerated dose (MTD) of rhizome extract was 1.3 g/kg. Rhizome extract (0.5 g/kg) in 60% ethanol was intra-peritoneally injected to albino rats and exposed to 100, 300 and 500 cGy. Radioprotective effect of the extract was determined by alkaline single cell comet assay. Significant reduction (P < 0.05) of comet DNA (68%) and length (61%)in rat bone marrow cells was observed at a radiation dose of 500 cGy. The results demonstrate that tropical ginger possess free radical scavenging properties and can protect bone marrow cells from radiation-induced DNA damages. The results on radiation induced DNA damage using plasmid pBR322 DNA obviously justify that the extract at a low dose can protect DNA from undergoing strand breakage due to gamma radiation exposure. Versatility of Zingiber montanum in different chemical assays in terms of its radical scavenging potential shows that this non-conventional food plant as a lot of potential in maintaining human health through dietary supplementation as nutraceutical. This candidate plant also can possibly be a promising candidate in clinical radiotherapy perhaps as a substitute of or the well-know radioprotector amifostine. (author)

  4. Radiation-Induced Cataractogenesis: A Critical Literature Review for the Interventional Radiologist

    Energy Technology Data Exchange (ETDEWEB)

    Seals, Kevin F., E-mail: KSeals@mednet.ucla.edu; Lee, Edward W., E-mail: EdwardLee@mednet.ucla.edu [David Geffen School of Medicine at UCLA, Division of Interventional Radiology, Department of Radiology, UCLA Medical Center (United States); Cagnon, Christopher H., E-mail: CCagnon@mednet.ucla.edu [University of California at Los Angeles, Department of Radiology (United States); Al-Hakim, Ramsey A., E-mail: RAlhakim@mednet.ucla.edu; Kee, Stephen T., E-mail: SKee@mednet.ucla.edu [David Geffen School of Medicine at UCLA, Division of Interventional Radiology, Department of Radiology, UCLA Medical Center (United States)

    2016-02-15

    Extensive research supports an association between radiation exposure and cataractogenesis. New data suggests that radiation-induced cataracts may form stochastically, without a threshold and at low radiation doses. We first review data linking cataractogenesis with interventional work. We then analyze the lens dose typical of various procedures, factors modulating dose, and predicted annual dosages. We conclude by critically evaluating the literature describing techniques for lens protection, finding that leaded eyeglasses may offer inadequate protection and exploring the available data on alternative strategies for cataract prevention.

  5. 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

  6. Down-regulation of ATM Protein Sensitizes Human Prostate Cancer Cells to Radiation-induced Apoptosis*

    OpenAIRE

    Truman, Jean-Philip; Gueven, Nuri; Lavin, Martin; Leibel, Steven; Kolesnick, Richard; Fuks, Zvi; Haimovitz-Friedman, Adriana

    2005-01-01

    Treatment with the protein kinase C activator 12-O tetradecanoylphorbol 12-acetate (TPA) enables radiation-resistant LNCaP human prostate cancer cells to undergo radiation-induced apoptosis, mediated via activation of the enzyme ceramide synthase (CS) and de novo synthesis of the sphingolipid ceramide (Garzotto, M., Haimovitz-Friedman, A., Liao, W. C., White-Jones, M., Huryk, R., Heston, D. W. W., Cardon-Cardo, C., Kolesnick, R., and Fuks, Z. (1999) Cancer Res. 59, 5194-5201). Here, we show t...

  7. Changes in plasma membrane state of thymocytes during spontaneous and radiation-induced leukemogenesis

    International Nuclear Information System (INIS)

    Changes in plasma membrane properties characteristic for malignant cells were reviewed. Investigations of spontaneous (in AKR mice) and radiation-induced (in C57Bl) leukemogenesis were carried out; changes in properties of Na+, K+ ATPase and alkaline phosphatase were characterized. On the basis of the results reported a pre-leukemic stage was distinguished, corresponding to the following features at the cellular level: increase in activity of alkaline phosphatase; decrease in relative activity of Na+, K+ ATPase; decrease in efficiency of the Na+ K+ pump; decrease in cAMP content. 473 refs. (author)

  8. Treatment of radiation-induced interstitial pneumonia in rats with compound anisodine on pathological study

    International Nuclear Information System (INIS)

    Interstitial pneumonia is a severe complication of radiation injury. In order to improve the therapeutic efficacy, we used compound anisodine (CA) to prevent and treat the radiation-induced pneumonia in rats. 45 Wistar rats were randomly divided into three groups: radiated group, CA-treated group, and control group. The thoraces of rats in the radiated group and CA-treated group received 30 Gy single exposure dose of 60Co γ-radiation. On 2 days before irradiation, the rats of CA-treated group were injected with CA subcutaneously once a day, until they were killed with other groups on days 15,30,50 after irradiation, respectively. The pathological morphology showed that the rats in the radiated group suffered from typical radiation-induced interstitial pneumonia, while the rats in the CA-treated group had only slight reactions in their lungs and recovered quickly. The experimental results indicate that in the early stage after radiation exposure, treatment and prevention of interstitial pneumonia in rats with CA is effective and CA can protect the lung tissues, prevent and relieve the radiation injury of lungs

  9. Ozone Therapy in the Management of Persistent Radiation-Induced Rectal Bleeding in Prostate Cancer Patients

    Directory of Open Access Journals (Sweden)

    Bernardino Clavo

    2015-01-01

    Full Text Available Introduction. Persistent radiation-induced proctitis and rectal bleeding are debilitating complications with limited therapeutic options. We present our experience with ozone therapy in the management of such refractory rectal bleeding. Methods. Patients (n=12 previously irradiated for prostate cancer with persistent or severe rectal bleeding without response to conventional treatment were enrolled to receive ozone therapy via rectal insufflations and/or topical application of ozonized-oil. Ten (83% patients had Grade 3 or Grade 4 toxicity. Median follow-up after ozone therapy was 104 months (range: 52–119. Results. Following ozone therapy, the median grade of toxicity improved from 3 to 1 (p<0.001 and the number of endoscopy treatments from 37 to 4 (p=0.032. Hemoglobin levels changed from 11.1 (7–14 g/dL to 13 (10–15 g/dL, before and after ozone therapy, respectively (p=0.008. Ozone therapy was well tolerated and no adverse effects were noted, except soft and temporary flatulence for some hours after each session. Conclusions. Ozone therapy was effective in radiation-induced rectal bleeding in prostate cancer patients without serious adverse events. It proved useful in the management of rectal bleeding and merits further evaluation.

  10. Overexpression of matrix metalloproteinase-12 (MMP-12) correlates with radiation-induced lung fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Myung Gu; Jeong, Ye Ji; Lee, Haejune [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Lee, Sujae [Hanyang Univ., Seoul (Korea, Republic of)

    2014-05-15

    MMPs are classified into five subgroups: collagenases (MMP-1, MMP-8, MMP-13), gelatinases (MMP-2, MMP-9), stromelysins (MMP-3, MMP-10, MMP-11), as well as metalloelastase (MMP-12), the membrane-type MMPs (MMP14, MMP15), and other MMPS (e. g., MMP-19, and MMP20). MMP-12 (matrix metalloproteinase12), also known as macrophage metalloelastase, was first identified as an elastolytic metalloproteinase secreted by inflammatory macrophages 30 years ago. MMP-12 degrades extracellular matrix (ECM) components to facilitate tissue remodeling. It can degrade elastin and other substrates, such as type IV collagen, fibronectin, laminin, gelatin, vitronectin, entactin, heparin, and chondroitin sulfates. In the lung, MMP-12 is identified in alveolar macrophages of cigarette smokers as an elastolytic MMP. Inactivation of the MMP-12 gene in knockout mice demonstrates a critical role of MMP-12 in smoking-induced chronic obstructive pulmonary disease (COPD). The aim of the present study was to investigate the effects of MMP-12 by radiation in lung, so we evaluate that MMP-12 expression pattern in normal lung tissue and cancer cell following radiation. Radiation induced lung injury most commonly occurs as a result of radiation therapy administered to treat cancer. The present study demonstrates that MMP-12 was highly increased in the lung damaged by radiation Thus, MMP-12 might be of potential relevance as a clinically diagnostic tool and sensitive biomarker for radiation induced lung injury and fibrosis.

  11. Mitigating the risk of radiation-induced cancers: limitations and paradigms in drug development

    International Nuclear Information System (INIS)

    The United States radiation medical countermeasures (MCM) programme for radiological and nuclear incidents has been focusing on developing mitigators for the acute radiation syndrome (ARS) and delayed effects of acute radiation exposure (DEARE), and biodosimetry technologies to provide radiation dose assessments for guiding treatment. Because a nuclear accident or terrorist incident could potentially expose a large number of people to low to moderate doses of ionising radiation, and thus increase their excess lifetime cancer risk, there is an interest in developing mitigators for this purpose. This article discusses the current status, issues, and challenges regarding development of mitigators against radiation-induced cancers. The challenges of developing mitigators for ARS include: the long latency between exposure and cancer manifestation, limitations of animal models, potential side effects of the mitigator itself, potential need for long-term use, the complexity of human trials to demonstrate effectiveness, and statistical power constraints for measuring health risks (and reduction of health risks after mitigation) following relatively low radiation doses (<0.75 Gy). Nevertheless, progress in the understanding of the molecular mechanisms resulting in radiation injury, along with parallel progress in dose assessment technologies, make this an opportune, if not critical, time to invest in research strategies that result in the development of agents to lower the risk of radiation-induced cancers for populations that survive a significant radiation exposure incident. (review)

  12. Influence of cigarette smoke and green tea on radiation-induced micronucleated polychromatic erythrocytes

    International Nuclear Information System (INIS)

    Objective: To observe the effects of cigarette smoke and green tea on radiation-induced bone marrow cell mutation, and to provide scientific information for prevention and treatment of radiation damage. Methods: There were 8 groups in the factorial experiment design with 3 factors at 2 levels. Mice were randomly divided into each group. There were 8 mice in each group. Mice in seven experimental groups were exposed to cigarette smoke, green tea, radiation or their mixtures respectively. One group was treated as the blank control group. The frequencies of micrnucleated polychromatic erythrocytes (MPCE) were scored by single blinded method. The data were analyzed with factorial experiments analysis of variance using SAS 8.0. Results: Analysis of variance showed that radiation, cigarette smoke and green tea were independently significant factors (P<0.01). Interactions between cigarette smoke and radiation or between green tea and radiation were statistically significant (P<0.01). Conclusion: Radiation and cigarette smoke can cause bone marrow cell mutations independently. There is synergistic effect between cigarette smoke and radiation. Green tea can inhibit radiation-induced cell mutation. (authors)

  13. The Development of Countermeasures for Space Radiation Induced Adverse Health Effects

    Science.gov (United States)

    Kennedy, Ann

    The Development of Countermeasures for Space Radiation Induced Adverse Health Effects Ann R. Kennedy Department of Radiation Oncology, University of Pennsylvania School of Medicine, 195 John Morgan Building, 3620 Hamilton Walk, Philadelphia, PA, United States 19104-6072 The development of countermeasures for radiation induced adverse health effects is a lengthy process, particularly when the countermeasure/drug has not yet been evaluated in human trials. One example of a drug developed from the bench to the clinic is the soybean-derived Bowman-Birk inhibitor (BBI), which has been developed as a countermeasure for radiation induced cancer. It was originally identified as a compound/drug that could prevent the radiation induced carcinogenic process in an in vitro assay system in 1975. The first observation that BBI could inhibit carcinogenesis in animals was in 1985. BBI received Investigational New Drug (IND) Status with the U.S. Food and Drug Administration (FDA) in 1992 (after several years of negotiation with the FDA about the potential IND status of the drug), and human trials began at that time. Phase I, II and III human trials utilizing BBI have been performed under several INDs with the FDA, and an ongoing Phase III trial will be ending in the very near future. Thus, the drug has been in development for 35 years at this point, and it is still not a prescription drug on the market which is available for human use. A somewhat less time-consuming process is to evaluate compounds that are on the GRAS (Generally Recognized as Safe) list. These compounds would include some over-the-counter medications, such as antioxidant vitamins utilized in human trials at the levels for which Recommended Dietary Allowances (RDAs) have been established. To determine whether GRAS substances are able to have beneficial effects on radiation induced adverse health effects, it is still likely to be a lengthy process involving many years to potentially decades of human trial work. The

  14. Radiation-induced genomic instability: Are epigenetic mechanisms the missing link?

    Energy Technology Data Exchange (ETDEWEB)

    Aypar, Umut; Morgan, William F.; Baulch, Janet E.

    2011-02-01

    Purpose: This review examines the evidence for the hypothesis that epigenetics are involved in the initiation and perpetuation of radiation-induced genomic instability (RIGI). Conclusion: In addition to the extensively studied targeted effects of radiation, it is now apparent that non-targeted delayed effects such as RIGI are also important post-irradiation outcomes. In RIGI, unirradiated progeny cells display phenotypic changes at delayed times after radiation of the parental cell. RIGI is thought to be important in the process of carcinogenesis, however, the mechanism by which this occurs remains to be elucidated. In the genomically unstable clones developed by Morgan and colleagues, radiation-induced mutations, double-strand breaks, or changes in mRNA levels alone could not account for the initiation or perpetuation of RIGI. Since changes in the DNA sequence could not fully explain the mechanism of RIGI, inherited epigenetic changes may be involved. Epigenetics are known to play an important role in many cellular processes and epigenetic aberrations can lead to carcinogenesis. Recent studies in the field of radiation biology suggest that the changes in methylation patterns may be involved in RIGI. Together these clues have led us to hypothesize that epigenetics may be the missing link in understanding the mechanism behind RIGI.

  15. Radiofrequency radiation-induced calcium ion efflux enhancement from human and other neuroblastoma cells in culture.

    Science.gov (United States)

    Dutta, S K; Ghosh, B; Blackman, C F

    1989-01-01

    To test the generality of radiofrequency radiation-induced changes in 45Ca2+ efflux from avian and feline brain tissues, human neuroblastoma cells were exposed to electromagnetic radiation at 147 MHz, amplitude-modulated (AM) at 16 Hz, at specific absorption rates (SAR) of 0.1, 0.05, 0.01, 0.005, 0.001, and 0.0005 W/kg. Significant 45Ca2+ efflux was obtained at SAR values of 0.05 and 0.005 W/kg. Enhanced efflux at 0.05 W/kg peaked at the 13-16 Hz and at the 57.5-60 Hz modulation ranges. A Chinese hamster-mouse hybrid neuroblastoma was also shown to exhibit enhanced radiation-induced 45Ca2+ efflux at an SAR of 0.05 W/kg, using 147 MHz, AM at 16 Hz. These results confirm that amplitude-modulated radiofrequency radiation can induce responses in cells of nervous tissue origin from widely different animal species, including humans. The results are also consistent with the reports of similar findings in avian and feline brain tissues and indicate the general nature of the phenomenon. PMID:2540756

  16. Radiation-induced effects in polarization-maintaining optical fibers for interferometric gyroscope

    Institute of Scientific and Technical Information of China (English)

    Xueqin Wang; Chunxi Zhang; Jing Jin; Ningfang Song

    2011-01-01

    @@ Radiation-induced attenuation (RIA) in four types of polarization-maintaining optical fibers for interferometric fiberoptic gyroscope (IFOG) at 1310 nm is measured.The measurements are conducted during and after steady-state γ-ray irradiation using a 60Co source in order to observe significantly different RIA behavior and recovery kinetics.Mechanisms involving dopants and manufacturing process are introduced to analyze the RIA discrepancy as well as to guide the choice and hardening of optical fibers during the design of IFOG.Medium-accuracy IFOG using Ge-F-codoped fiber and pure silica core fiber can survive in the space radiation environment.%Radiation-induced attenuation (RIA) in four types of polarization-maintaining optical fibers for interferometric fiberoptic gyroscope (IFOG) at 1310 nm is measured. The measurements are conducted during and after steady-state γ-ray irradiation using a 60Co source in order to observe significantly different RIA behavior and recovery kinetics. Mechanisms involving dopants and manufacturing process are introduced to analyze the RIA discrepancy as well as to guide the choice and hardening of optical fibers during the design of IFOG. Medium-accuracy IFOG using Ge-F-codoped fiber and pure silica core fiber can survive in the space radiation environment.

  17. A case of radiation-induced chronic constrictive pericarditis developing 16 years after irradiation

    International Nuclear Information System (INIS)

    We reported a 51-yr-old female with radiation-induced chronic constrictive pericarditis. At age 29, she had received mastectomy and postoperative irradiation because of left breast cancer. At age 45, she had syncope and was diagnosed with complete atrioventricular block and a pacemaker was implanted. At that time, pericardial thickening with effusion was noted. The following year, tricuspid regurgitation was noted. On catheter study, a dip and plateau pattern of the right ventricular pressure curve appeared. At age 50, tricuspid regurgitation worsened due to the lead wire of the pacemaker compressing the leaflet, and the pacemaker was reimplanted. However, the following year, she complained of general fatigue and dyspnea and was admitted to our hospital. On 67Ga study, diffuse accumulation in the cardiac region appeared. There was no perfusion defect detected in the myocardium, but right myocardial damage was suspected by thallium study. In 99mTc-HSA RI angiography, right atrium dilatation appeared and a pericardial halo around the ventricles was seen. She underwent pericardectomy, tricuspid replacement and pacemaker reimplanted, but she died. On autpsy, pericardial thickening and adhesion, right myocardial fibrosis, the fibrotic change of the bundle branches were seen. We reported a case of radiation-induced constrictive pericarditis. Radionuclide studies were useful in diagnosing and following the patient. (author)

  18. Modification of nylon-6 fibres by radiation-induced graft polymerisation of vinylbenzyl chloride

    International Nuclear Information System (INIS)

    Modification of nylon-6 fibres by radiation-induced graft copolymerisation (RIGP) of vinylbenzyl chloride (VBC) using the preirradiation method was investigated. A number of grafting parameters such as type of solvent, total dose, monomer concentrations, reaction temperature and reaction time were studied to obtain desired degree of grafting (DG). The DG was found to be a function of reaction parameters and achieved a maximum value of 130 wt% at 20 vol% VBC concentration in methanol, 300 kGy dose, 30 °C temperature and 3 h reaction time. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD) were employed to evaluate the chemical, morphological and structural changes that occurred in the grafted fibres, respectively. Thermogravimetric analysis (TGA) was also applied to determine the thermal stability, whereas differential scanning calorimeter (DSC) and universal mechanical tester were used to analyse respective thermal and mechanical properties of the grafted fibres. The results of these analyses provide strong evidence for successful grafting of VBC onto nylon-6, and the variation in the properties of the grafted fibres depends on DG. - Highlights: • Modification of nylon-6 fibres by radiation induced grafting of VBC in methanol. • Establishment of relations between DG and reaction parameters. • Evidence of VBC grafting was provided by FTIR, SEM, XRD, DSC and TGA. • The properties of VBC-grafted nylon-6 fibres depend on DG. • Amendable VBC-grafted nylon-6 fibres retain favourable properties

  19. Paradoxical relationship between Mn superoxide dismutase deficiency and radiation-induced cognitive defects.

    Directory of Open Access Journals (Sweden)

    Rikki Corniola

    Full Text Available Radiation therapy of the CNS, even at low doses, can lead to deficits in neurocognitive functions. Reduction in hippocampal neurogenesis is usually, but not always, associated with cognitive deficits resulting from radiation therapy. Generation of reactive oxygen species is considered the main cause of radiation-induced tissue injuries, and elevated levels of oxidative stress persist long after the initial cranial irradiation. Consequently, mutant mice with reduced levels of the mitochondrial antioxidant enzyme, Mn superoxide dismutase (MnSOD or Sod2, are expected to be more sensitive to radiation-induced changes in hippocampal neurogenesis and the related functions. In this study, we showed that MnSOD deficiency led to reduced generation of immature neurons in Sod2-/+ mice even though progenitor cell proliferation was not affected. Compared to irradiated Sod2+/+ mice, which showed cognitive defects and reduced differentiation of newborn cells towards the neuronal lineage, irradiated Sod2-/+ mice showed normal hippocampal-dependent cognitive functions and normal differentiation pattern for newborn neurons and astroglia. However, we also observed a disproportional decrease in newborn neurons in irradiated Sod2-/+ following behavioral studies, suggesting that MnSOD deficiency may render newborn neurons more sensitive to stress from behavioral trainings following cranial irradiation. A positive correlation between normal cognitive functions and normal dendritic spine densities in dentate granule cells was observed. The data suggest that maintenance of synaptic connections, via maintenance of dendritic spines, may be important for normal cognitive functions following cranial irradiation.

  20. Radiation-Induced Testicular Injury and Its Amelioration by Tinospora cordifolia (An Indian Medicinal Plant Extract

    Directory of Open Access Journals (Sweden)

    Priyanka Sharma

    2011-01-01

    Full Text Available The primary objective of this investigation is to determine the deleterious effects of sub lethal gamma radiation on testes and their possible inhibition by Tinospora cordifolia extract (TCE. For this purpose, one group of male Swiss albino mice was exposed to 7.5 Gy gamma radiation to serve as the irradiated control, while the other group received TCE (75 mg/kg b. wt./day orally for 5 consecutive days half an hr before irradiation to serve as experimental. Exposure of animals to 7.5 Gy gamma radiation resulted into significant decrease in body weight, tissue weight, testes- body weight ratio and tubular diameter up to 15 days of irradiation. Cent percent mortality was recorded by day 17th in irradiated control, whereas all animals survived in experimental group. TCE pretreatment rendered significant increase in body weight, tissue weight, testes- body weight ratio and tubular diameter at various intervals as compared to irradiated group. Radiation induced histological lesions in testicular architecture were observed more severe in irradiated control then the experimental. TCE administration before irradiation significantly ameliorated radiation induced elevation in lipid peroxidation and decline in glutathione concentration in testes. These observations indicate the radio- protective potential of Tinospora cordifolia root extract in testicular constituents against gamma irradiation in mice.

  1. Radiation-induced grafting of sweet sorghum stalk for copper(II) removal from aqueous solution

    International Nuclear Information System (INIS)

    Highlights: • Radiation-induced grafting was used to modify the stalk. • Cellulose, hemicellulose and lignin participated in grafting reaction. • Both the structure and composition of stalk had influence on grafting. • The sorption capacity of the grafted stalk increased about five times. -- Abstract: The influence of main components (cellulose, hemicellulose and lignin) of the sweet sorghum stalk on radiation-induced grafting reaction and adsorption of copper from aqueous solution was investigated. Sweet sorghum stalk was grafted with acrylic acid induced by γ-irradiation. The results showed that the grafted stalk contained 1.6 mmol/g carboxyl groups, and its maximal adsorption capacity was 13.32 mg/g. The cellulose, hemicellulose and lignin of the raw materials were confirmed to involve in grafting reaction through comparing the grafting yield and the structure of the grafted materials. Both the structure and the composition of the sweet sorghum stalk had influence on the grafting reaction and adsorption capacity. The adsorption capacity of the grafted sweet sorghum stalk increased about five times, and the adsorption isotherm of the grafted materials conformed to the Langmuir model. The main mechanism for copper adsorption involved in ion exchange

  2. Gymnemagenin-a triterpene saponin prevents γ-radiation induced cellular DNA damage

    International Nuclear Information System (INIS)

    Gymnema sylvestre an ethno-medicinally important plant was investigated for its protecting activity against radiation induced DNA damage. The major bioactive component present in Gymnema sylvestre such as gymnemic acid and gymnemagenin a triterpene saponin, were tested for its radioprotective effects against 60Co irradiation induced DNA damage in fish model using fresh water fish Pangasius sutchi. Fishes subjected to a dose of 133 Gy of gamma radiation and observed for eight days. The genotoxic assessment by micronucleus assay showed us that that the plant extract helped in reducing the frequency of micronucleated and binucleated erythrocytes compared to the irradiated control group. The genotoxic assessment by alkaline comet assay by single gel electrophoresis shows that pretreatment with the plant extract appreciably decreased the percentage of tail DNA towards the levels close to those of normal control group. The gradual increase in the level of the antioxidant enzymes: superoxide dismutase (SOD) and catalase (CAT) during the course of the experiment indicates that the antioxidant enzyme activities play an important role in protecting organisms against gamma radiation-induced cellular oxidative stress. In conclusion the leaf extracts of Gymnema sylvstre exerts its radio protective potential by suppressing the toxic assault of ROS generated by the ionizing radiation through its ability to boost the levels of antioxidant enzymes (CAT and SOD) due to the presence of its phytochemicals like gymnemgenenin- a Triterpene Saponin. (author)

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

    International Nuclear Information System (INIS)

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

  4. Prevention effects of Schisandra polysaccharide on radiation-induced immune system dysfunction.

    Science.gov (United States)

    Zhao, Lian-Mei; Jia, Yun-Long; Ma, Ming; Duan, Yu-Qing; Liu, Li-Hua

    2015-05-01

    In this study, we investigate the efficacy of SP (Schisandra polysaccharide) in prevention of radiation-induced immune dysfunction and discussed the underlying mechanisms with a Bal/bc mouse model. The data demonstrated that SP could reverse the decreases in the number of white blood cells and lymphocytes in peripheral blood. In addition, the immunoglobulin G (IgG) and complement C3 in blood serum were all decreased after radiation and SP could restore this radiation disorder. Furthermore, SP could reverse the deregulation of CD3(+)CD4(+) and CD3(+)CD8(+) T cell subsets in peripheral blood and thymus of mice after radiotherapy. We also performed terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) and Immunohistochemistry (IHC) to investigate the apoptosis and underlying mechanisms of SP in thymus. Data showed that radiation-induced apoptosis of thymocytes could be reversed by SP through inducing upregulation of Bcl-2 expression and downregulation of Fas and Bax levels. Furthermore, SP has no any side-effects on immunity of normal mice. In conclusion, our results indicated that SP could effectively prevent immune injury during radiotherapy by protecting the immune system. This valuable information should be of assistance in choosing a rational design for therapeutic interventions of prevention immune system damage in the radiation treatment.

  5. Protective effects of alpha lipoic acid on radiation-induced salivary gland injury in rats

    Science.gov (United States)

    Kim, Jin Hyun; Kim, Kyung Mi; Jung, Myeong Hee; Jung, Jung Hwa; Kang, Ki Mun; Jeong, Bae Kwon; Kim, Jin Pyeong; Park, Jung Je; Woo, Seung Hoon

    2016-01-01

    Purpose Radiation therapy is a treatment for patients with head and neck (HN) cancer. However, radiation exposure to the HN often induces salivary gland (SG) dysfunction. We investigated the effect of α-lipoic acid (ALA) on radiation-induced SG injury in rats. Results ALA preserved acinoductal integrity and acinar cell secretary function following irradiation. These results are related to the mechanisms by which ALA inhibits oxidative stress by inhibiting gp91 mRNA and 8-OHdG expression and apoptosis of acinar cells and ductal cells by inactivating MAPKs in the early period and expression of inflammation-related factors including NF-κB, IκB-α, and TGF-β1 and fibrosis in late irradiated SG. ALA effects began in the acute phase and persisted for at least 56 days after irradiation. Materials and Methods Rats were assigned to followings: control, ALA only (100 mg/kg, i.p.), irradiated, and ALA administered 24 h and 30 min prior to irradiation. The neck area including the SG was evenly irradiated with 2 Gy per minute (total dose, 18 Gy) using a photon 6-MV linear accelerator. Rats were killed at 4, 7, 28, and 56 days after radiation. Conclusions Our results show that ALA could be used to ameliorate radiation-induced SG injury in patients with HN cancer. PMID:27072584

  6. Protective effects of catecholomic acid derivatives on radiation-induced damage of rat liver mitochondria

    International Nuclear Information System (INIS)

    Objective: To evaluate the effects of catecholomic acid derivatives 9501, 9502 and 7601 (CBMIDA) against radiation-induced injury of rat liver mitochondria in vitro. Methods: The injury of rat liver mitochondria was induced by γ-irradiation in vitro. The contents of MDA were assayed by spectrophotometry of TBA. The absorption value at 520 nm was measured to detect swelling of mitochondria. The electron microscopic samples of mitochondria were prepared. Results: All 9501 (5 x 10-6 mol/L), 9502(10-5 mol/L), and 7601 (10-5 mol/L) significantly inhibited radiation-induced increase of MDA information.The swelling of mitochondria induced by irradiation was also prevented by 9501, 7601. The electron micrographs also showed that 9501 markedly reduced the pathological damage of mitochondria induced by γ-irradiation. The mechanisms of anti-oxidative action of catecholomic acid derivatives was discussed. Conclusion: Injurious effect of radiation on rat liver mitochondria can be prevented by catecholomic acid derivatives 9501, 9502 and 7601 (CBMIDA)

  7. Bio-mechanical and morphometric evaluation of late radiation-induced changes in the mouse rectum

    International Nuclear Information System (INIS)

    The overall aim of this thesis was to study the development of late radiation induced damage of the rectum and describe the histopathological and morphometric characteristics of the late injury. This required the design of a new, small probe for rectal measurements of cross-sectional area and distension pressure in mice. The impedance planimetric method was developed and validated in vitro and applied in in vivo studies of normal mice. The study of radiation induced damage of the rectum also required a new set-up for selective irradiation of a specific part of the rectum, shielding other organs. Mice were irradiated with varying single doses and followed with impedance planimetric measurements at regular intervals until death of the animals. In order to compare observed changes of the functional properties of the rectum following irradiation, a description of morphometric and morphologic characteristics by a stereolic technique was planned. A simplified stereological method has been applied to this study to describe late morphometric changes in the different intestinal layers after irradiation with varying single doses. (EG)

  8. Punica granatum peel extract protects against ionizing radiation-induced enteritis and leukocyte apoptosis in rats

    International Nuclear Information System (INIS)

    Radiation-induced enteritis is a well-recognized sequel of therapeutic irradiation. Therefore we examined the radioprotective properties of Punica granatum peel extract (PPE) on the oxidative damage in the ileum. Rats were exposed to a single whole-body X-ray irradiation of 800 cGy. Irradiated rats were pretreated orally with saline or PPE (50 mg/kg/day) for 10 days before irradiation and the following 10 days, while control rats received saline or PPE but no irradiation. Then plasma and ileum samples were obtained. Irradiation caused a decrease in glutathione and total antioxidant capacity, which was accompanied by increases in malondialdehyde levels, myeloperoxidase activity, collagen content of the tissue with a concomitant increase 8-hydroxy-2'-deoxyguanosine (an index of oxidative DNA damage). Similarly, pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) and lactate dehydrogenase were elevated in irradiated groups as compared to control. PPE treatment reversed all these biochemical indices, as well as histopathological alterations induced by irradiation. Furthermore, flow cytometric measurements revealed that leukocyte apoptosis and cell death were increased in irradiated animals, while PPE reversed these effects. PPE supplementation reduced oxidative damage in the ileal tissues, probably by a mechanism that is associated with the decreased production of reactive oxygen metabolites and enhancement of antioxidant mechanisms. Adjuvant therapy of PPE may have a potential to support a successful radiotherapy by protecting against radiation-induced enteritis. (author)

  9. The Protective Effect of Amifostine on Radiation-Induced Proctitis: Systemic Versus Topical Application

    Directory of Open Access Journals (Sweden)

    Cem Uzal

    2012-03-01

    Full Text Available Objective: The aim of the study was to evaluate the radioprotective efficacy of intrarectal administration of amifostine in radiation-induced proctitis compared to intraperitoneal administration.Materials and Methods: Thirty-two Sprague-Dawley rats were randomly divided into four groups: Control (CONT, irradiation alone (RT, intraperitoneal amifostine plus irradiation (IPAMI, and intrarectal amifostine plus irradiation (IRAMI. The rats in the RT, IPAMI and IRAMI groups were irradiated individually with a single dose of 17.5 Gy to the pelvis. Amifostine was administered by the intraperitoneal (200 mg/kg or intrarectal (2000 mg/kg route before irradiation. Histopathologic analysis of the rectum was performed 14 days after irradiation. Results: Significant radiation damage appeared in all histopathologic parameters and was reduced by amifostine. Pretreatment with IPAMI significantly reduced the inflammatory infiltrate in the lamina propria (p=0.021, cryptitis (p=0.002 and crypt abscess (p=0.015. However, the protective effect of IRAMI was significant for all parameters with equal or higher significance than IPAMI, including the eosinophil leucocytes count (p=0.02, and distortion of the crypts (p=0.008, and was also significant for regenerative/reparative atypia (p=0.013. Conclusion: Intrarectal high dose topical administration of amifostine is more effective in the prevention of radiation-induced proctitis compared to its intraperitoneal systemic administration.

  10. Experimental study on the inhibitory effect of MSCs on radiation-induced thymoma in mice

    Institute of Scientific and Technical Information of China (English)

    Wen-Long Zhang

    2016-01-01

    Objective:To study the inhibitory effect of MSCs on radiation-induced thymoma in mice. Methods:C57BL/6 mice were selected as the research objects, model group and MSCs group induced thymoma by radiation, and MSCs group received intravenous injection of mesenchymal stem cell for therapy. Six months after treatment, macroscopic morphology of thymus tissue, contents of T lymphocyte subsets as well as expression of tumor suppressor gene PTEN and proliferation marker molecule Ki-67 were detected.Results:(1) macroscopic morphology: thymus tissue weight of model group was significantly greater than that of control group and thymus tissue weight of MSCs group was lower than that of control group; (2) cells and molecules: compared with control group, contents of CD4-CD8-, CD4+CD8- and CD4-CD8+ T cells as well as expression of PTEN in thymus tissue of model group significantly decreased, and CD4+CD8+ T cell content as well as Ki-67 expression significantly increased; compared with model group, contents of CD4-CD8-, CD4+CD8- and CD4-CD8+ T cells as well as expression of PTEN in thymus tissue of MSCs group significantly increased, and CD4+CD8+ T cell content as well as Ki-67 expression significantly decreased.Conclusions:MSCs have inhibitory effect on radiation-induced thymoma in mice, manifested as promoting CD4+CD8- and CD4-CD8+ T cell maturation as well as inhibiting cell proliferation.

  11. Effects of gargle with Inchin-gorei-san for radiation-induced stomatitis

    International Nuclear Information System (INIS)

    One of the adverse effects of radiotherapy for oral cancer is radiation-induced stomatitis. To relieve this severe mucosal condition, we tried the use of gargling with Inchin-gorei-san solution. Eleven patients (gargle group) gargled daily with Inchin-gorei-san in combination with steroid ointment application. The Inchin-gorei-san solution was used at 7.5 g/l in distilled water. Seven patients (control group) received application of steroid ointment without using the gargle. The period until the appearance of pain ranged from 0 to 25 days (median, 12.9 days) in the gargle group and 5 to 17 days (median, 8.9 days) in the control group. The duration of pain in the gargle and control groups was 0 to 46 days and 10 to 43 days, respectively. The period until the appearance of stomatitis was 3 to 20 days (median, 11.6 days) in the gargle group and 3 to 17 days (median, 7.7 days) in the control group. The duration of stomatitis in the gargle and control groups was 5 to 17 days and 10 to 54 days, respectively. These findings suggest that gargling with Inchin-gorei-san is a useful treatment for radiation-induced oral stomatitis. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-11-15

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

  13. A case of radiation-induced skin cancer of the neck

    International Nuclear Information System (INIS)

    The authors discuss the case of radiation-induced skin cancer of the neck in a 76-year-old woman who had undergone irradiation of tubercular lymphadenitis of the cervix while in her low teens. Some fifty years later, a squamous cell carcinoma developed in the irradiated region and in due course deeply invaded the sternocleidomastoidous muscle. Thus, a radical neck dissection was performed and the tumor and the lymph tissue removed en bloc, after which reconstruction was accomplished by using a latissimus dorsi musculocutaneous flap. With regard to the lessons learned from treating this case, three points are considered important and are listed below. When treating radiation-induced skin cancer patients, the head and neck regions should be examined in detail for the presence of other tumors. The excision of the skin surrounding the tumor should be as wide as possible, so as to remove skin that may have been also over-subjected to irradiation. The remaining skin surrounding the defect left by the excision is atrophic and thin. (author)

  14. The role of sucralfate oral suspension in prevention of radiation induced mucositis

    Directory of Open Access Journals (Sweden)

    Hamid Emami

    2008-12-01

    Full Text Available

    • BACKGROUND: Mucositis is one of the most common complications of radiotherapy in head and neck cancers. The aim of this study was to evaluate sucralfate mouthwash in prevention of radiation induced mucositis.
    • METHODS: A clinical randomized trial performed on 52 patients with head and neck cancers in Sayyed-Al-Shohada Hospital of Isfahan University of Medical Sciences. These patients randomly assigned in 2 groups of 26 patients. Placebo and sucralfate was used for control and experimental patients respectiv ly, from the beginning of radiotherapy. Patients were visited weekly until the end of treatment. Grade of the mucositis was evaluated according to WHO grading scale.
    • RESULTS: Sucralfate significantly reduced the mean grade of mucositis in weeks one to four (with P-values of 0.02, 0.02, 0.001 and 0.004, respectively. Development of grade3 mucositis was also lower in sucralfate group (P-value = 0.0001. But, time interval between radiotherapy and appearance of mucositis was not statistically different in the two groups (P-value = 0.9
    • CONCLUSIONS: This study indicated that using oral suspension of sucralfate reduced the grade of radiation-induced mucositis, but did not prevent or delay it.
    • KEYWORDS: Mucositis, radiotherapy, sucralfate, head and neck cancers.

  15. Acupuncture for the prevention of radiation-induced xerostomia in patients with head and neck cancer

    Directory of Open Access Journals (Sweden)

    Fabio do Prado Florence Braga

    2011-04-01

    Full Text Available The aim of this study was to evaluate the effectiveness of acupuncture in minimizing the severity of radiation-induced xerostomia in patients with head and neck cancer. A total of 24 consecutive patients receiving > 5000 cGy radiotherapy (RT involving the major salivary glands bilaterally were assigned to either the preventive acupuncture group (PA, n = 12, treated with acupuncture before and during RT, or the control group (CT, n = 12, treated with RT and not receiving acupuncture. After RT completion, clinical response was assessed in all patients by syalometry, measuring the resting (RSFR and stimulated (SSFR salivary flow rates, and by the visual analogue scale (VAS regarding dry mouth-related symptoms. Statistical analyses were performed with repeated-measures using a mixed-effect modeling procedure and analysis of variance. An alpha level of 0.05 was accepted for statistical significance. Although all patients exhibited some degree of impairment in salivary gland functioning after RT, significant differences were found between the groups. Patients in the PA group showed improved salivary flow rates (RSFR, SSFR; p < 0.001 and decreased xerostomia-related symptoms (VAS, p < 0.05 compared with patients in the CT group. Although PA treatment did not prevent the oral sequelae of RT completely, it significantly minimized the severity of radiation-induced xerostomia. The results suggest that acupuncture focused in a preventive approach can be a useful therapy in the management of patients with head and neck cancer undergoing RT.

  16. Ionizing radiation induces immediate protein acetylation changes in human cardiac microvascular endothelial cells

    International Nuclear Information System (INIS)

    Reversible lysine acetylation is a highly regulated post-translational protein modification that is known to regulate several signaling pathways. However, little is known about the radiation-induced changes in the acetylome. In this study, we analyzed the acute post-translational acetylation changes in primary human cardiac microvascular endothelial cells 4 h after a gamma radiation dose of 2 Gy. The acetylated peptides were enriched using anti-acetyl conjugated agarose beads. A total of 54 proteins were found to be altered in their acetylation status, 23 of which were deacetylated and 31 acetylated. Pathway analyses showed three protein categories particularly affected by radiation-induced changes in the acetylation status: the proteins involved in the translation process, the proteins of stress response, and mitochondrial proteins. The activation of the canonical and non-canonical Wnt signaling pathways affecting actin cytoskeleton signaling and cell cycle progression was predicted. The protein expression levels of two nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases, sirtuin 1 and sirtuin 3, were significantly but transiently upregulated 4 but not 24 h after irradiation. The status of the p53 protein, a target of sirtuin 1, was found to be rapidly stabilized by acetylation after radiation exposure. These findings indicate that post-translational modification of proteins by acetylation and deacetylation is essentially affecting the radiation response of the endothelium. (author)

  17. Hepatocyte growth factor gene therapy prevents radiation-induced liver damage

    Institute of Scientific and Technical Information of China (English)

    Chau-Hua Chi; I-Li Liu; Wei-Yu Lo; Bor-Song Liaw; Yu-Shan Wang; Kwan-Hwa Chi

    2005-01-01

    AIM: To transfer human HGF gene into the liver of rats by direct electroporation as a means to prevent radiationinduced liver damage.METHODS: Rat whole liver irradiation model was accomplished by intra-operative approach. HGF plasmid was injected into liver and transferred by electroporation using a pulse generator. Control rats (n = 8) received electrogene therapy (EGT) vehicle plasmid and another 8rats received HGF-EGT 100 μg 48 h before WLIR.Expression of HGF in liver was examined by RT-PCR and ELISA methods. Apoptosis was determined by TUNEL assay. Histopathology was evaluated 10 wk after whole liver irradiation.RESULTS: Marked decrease of apoptotic cells and downregulation of transforming growth factor-beta 1 (TGF-β1)mRNA were observed in the HGF-EGT group 2 d after liver irradiation compared to control animals. Less evidence of radiation-induced liver damage was observed morphologically in liver specimen 10 wk after liver irradiation and longer median survival time was observed from HGF-EGT group (14 wk) compared to control rats (5 wk). (P = 0.031).CONCLUSION: For the first time it has been demonstrated that HGF-EGT would prevent liver from radiation-induced liver damage by preventing apoptosis and down-regulation of TGF-β1.

  18. Radiation induced grafting of N,N-dimethylacrylamide onto polyester film

    International Nuclear Information System (INIS)

    Radiation induced grafting of N,N-dimethylacrylamide onto polyester film has been studied by means of immersion method. Polyester film was immersed in the aqueous solution of N,N-dimethylacrylamide containing potassium ferricyanide as homo-polymerization inhibitor and chloroform as swelling and activation agent for polyester film, and was irradiated with gamma ray at a temperature between 00C and 500C. Radiation induced grafting of N,N-dimethylacrylamide onto polyester film by means of immersion method took place when small amount of chloroform was contained in the aqueous solution. The relation between grafting ratio and irradiation time t is shown as follows. G equals kt, where G: grafting ratio (%), t: irradiation time (hr), k: constant. Grafting ratio was constant for the grafting system where the aqueous solution was saturated with chloroform. The apparent activation energy was determined to be 10.6 kcal/mole between 00C and 400C for the mixture of N,N-dimethylacrylamide-chloroform-water. From the observation of X-ray diffraction pattern, cross-section microphotograph and differential scanning calorimetry, it was suggested that N,N-dimethylacrylamide was grafted in the amorphous region of polyester film and penetrated through the whole section of the film, and grafted N,N-dimethylacrylamide itself was in amorphous state. Water content of the N,N-dimethylacrylamide grafted polyester increased with increase of grafting ratio. S equals 0.22G, where s: swelling ratio, G: grafting ratio (%). (author)

  19. Lack of p53 function promotes radiation-induced mitotic catastrophe in mouse embryonic fibroblast cells

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    Phillips Stacia L

    2006-04-01

    Full Text Available Abstract Background We have demonstrated that in some human cancer cells both chronic mild heat and ionizing radiation exposures induce a transient block in S and G2 phases of the cell cycle. During this delay, cyclin B1 protein accumulates to supranormal levels, cyclin B1-dependent kinase is activated, and abrogation of the G2/M checkpoint control occurs resulting in mitotic catastrophe (MC. Results Using syngenic mouse embryonic fibroblasts (MEF with wild-type or mutant p53, we now show that, while both cell lines exhibit delays in S/G2 phase post-irradiation, the mutant p53 cells show elevated levels of cyclin B1 followed by MC, while the wild-type p53 cells present both a lower accumulation of cyclin B1 and a lower frequency of MC. Conclusion These results are in line with studies reporting the role of p53 as a post-transcriptional regulator of cyclin B1 protein and confirm that dysregulation of cyclin B1 promote radiation-induced MC. These findings might be exploited to design strategies to augment the yield of MC in tumor cells that are resistant to radiation-induced apoptosis.

  20. Enhanced radiation-induced cell killing by Herbimycin A pre-treatment

    Science.gov (United States)

    Noguchi, Miho; Hirayama, Ryoichi; Druzhinin, Sergey; Okayasu, Ryuichi

    2009-12-01

    Herbimycin A (HA), as in Geldanamycin, binds to conserved pockets of heat shock protein 90 (Hsp90) and inhibits its chaperone functions. Hsp90 plays an integral role in cancer cell growth and survival, because it maintains the stability of several key proteins by its chaperone's activity. It is known that some of the proteins associated with radiation responses are functionally stabilized by Hsp90. In this study, we investigated the effect of HA on radiosensitivity in human cancer cells and the mechanism related to the sensitization. In order to gain a mechanistic insight of this sensitization, we examined repair of DNA double-strand breaks (DSBs) in irradiated human cancer cells pre-treated with HA, as unrepaired DSBs are thought to be the main cause of radiation-induced cell death. Cellular radiosensitivity was determined by clonogenic assay, and the DSB rejoining kinetics was examined by constant field gel electrophoresis. SQ-5, a lung squamous carcinoma cell line, showed synergistic increase in radiosensitivity when cells were pre-treated with HA. In addition, HA significantly inhibited repair of radiation-induced DSBs. These results suggest that the combination of HA and ionizing radiation may be a useful therapeutic strategy for treating certain cancer cells.

  1. Enhanced radiation-induced cell killing by Herbimycin A pre-treatment

    Energy Technology Data Exchange (ETDEWEB)

    Noguchi, Miho [Basic Radiation Research Group, Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakata-Shirane, Toukai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Hirayama, Ryoichi; Druzhinin, Sergey [Heavy-Ion Radiobiology Research Group, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555 (Japan); Okayasu, Ryuichi [Heavy-Ion Radiobiology Research Group, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555 (Japan)], E-mail: rokayasu@nirs.go.jp

    2009-12-15

    Herbimycin A (HA), as in Geldanamycin, binds to conserved pockets of heat shock protein 90 (Hsp90) and inhibits its chaperone functions. Hsp90 plays an integral role in cancer cell growth and survival, because it maintains the stability of several key proteins by its chaperone's activity. It is known that some of the proteins associated with radiation responses are functionally stabilized by Hsp90. In this study, we investigated the effect of HA on radiosensitivity in human cancer cells and the mechanism related to the sensitization. In order to gain a mechanistic insight of this sensitization, we examined repair of DNA double-strand breaks (DSBs) in irradiated human cancer cells pre-treated with HA, as unrepaired DSBs are thought to be the main cause of radiation-induced cell death. Cellular radiosensitivity was determined by clonogenic assay, and the DSB rejoining kinetics was examined by constant field gel electrophoresis. SQ-5, a lung squamous carcinoma cell line, showed synergistic increase in radiosensitivity when cells were pre-treated with HA. In addition, HA significantly inhibited repair of radiation-induced DSBs. These results suggest that the combination of HA and ionizing radiation may be a useful therapeutic strategy for treating certain cancer cells.

  2. Protection by polaprezinc against radiation-induced apoptosis in rat jejunal crypt cells

    International Nuclear Information System (INIS)

    Polaprezinc, an anti-ulcer drug, is a chelate compound consisting of zinc and L-carnosine. Polaprezinc has been shown to prevent gastric mucosal injury. The anti ulcer effects of polaprezinc have been ascribed to its antioxidative property. The effect of polaprezinc on ionizing radiation-induced apoptosis was studied in the jejunal epithelial crypt cells of rats. Seven-to eight week-old Wistar rats, which were treated with 100 mg/kg of polaprezinc orally 1 h before irradiation or 2% carboxymethyl cellulose sodium in controls, were exposed to whole body X-ray irradiation at 2 Gy. The number of apoptotic cells per jejunum crypt was counted in haematoxylin and eosin stained sections at 0-6 h after irradiation. TdT-mediated dUTP-biotin nick end-labeling (TUNEL) positive cells and immunopositive cells for active caspase-3 per crypt were also counted. Accumulation of p53, p21WAF1/CIP1 and Bax expression in the jejunum after irradiation were examined by Western blot analyses. Polaprezinc treatment given prior to radiation resulted in a significant reduction in numbers of apoptotic cells, TUNEL positive cells and active caspase-3 immunopositive cells in jejunal crypt cells. Polaprezinc treatment resulted in decreases of p53 accumulation, p21WAF1/CIP1 and Bax expression after irradiation. Polaprezinc has a protective effect against ionizing radiation induced apoptosis in rat jejunal crypt cells. (author)

  3. Protection by polaprezinc against radiation-induced apoptosis in rat jejunal crypt cells.

    Science.gov (United States)

    Matsuu-Matsuyama, Mutsumi; Shichijo, Kazuko; Okaichi, Kumio; Nakayama, Toshiyuki; Nakashima, Masahiro; Uemura, Takashi; Niino, Daisuke; Sekine, Ichiro

    2008-07-01

    Polaprezinc, an anti-ulcer drug, is a chelate compound consisting of zinc and L-carnosine. Polaprezinc has been shown to prevent gastric mucosal injury. The anti ulcer effects of polaprezinc have been ascribed to its antioxidative property. The effect of polaprezinc on ionizing radiation-induced apoptosis was studied in the jejunal epithelial crypt cells of rats. Seven-to eight week-old Wistar rats, which were treated with 100 mg/kg of polaprezinc orally 1h before irradiation or 2% carboxymethyl cellulose sodium in controls, were exposed to whole body X-ray irradiation at 2 Gy. The number of apoptotic cells per jejunum crypt was counted in haematoxylin and eosin stained sections at 0-6 h after irradiation. TUNEL positive cells and immunopositive cells for active caspase-3 per crypt were also counted. Accumulation of p53, p21(WAF1/CIP1) and Bax expression in the jejunum after irradiation were examined by Western blot analyses. Polaprezinc treatment given prior to radiation resulted in a significant reduction in numbers of apoptotic cells, TUNEL positive cells and active caspase-3 immunopositive cells in jejunal crypt cells. Polaprezinc treatment resulted in decreases of p53 accumulation, p21(WAF1/CIP1) and Bax expression after irradiation. Polaprezinc has a protective effect against ionizing radiation induced apoptosis in rat jejunal crypt cells. PMID:18413982

  4. Introduction of various amine groups onto polyethylene bead prepared by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Complete text of publication follows. Radiation-induced graft polymerization is a good method for modification of chemical and physical properties of polymeric materials because it can endow properties such as membrane quality, ion exchange, blood compatibility, dyeability, protein adsorption, and immobilization of bioactive materials. Polyethylene microbead is very useful material due to the following advantages; low price, simple purchase, high sensitivity, and simple analysis. On the other hand, the epoxy group of the glycidyl methacrylate (GMA) can easily be converted to the various functional groups such as amines, alcohols, phosphoric acid, sulfonic acid, and amino acid, etc. Cyclodextrin have been applied universally in various industries such as foods, cosmetics, pharmaceutical industry, analytical chemistry, and chemical industry. In order to obtain cyclodextrins, polyethylene microbead with the epoxy group were prepared by radiation-induced graft polymerization of GMA onto polyethylene microbead. The physical and chemical properties of the GMA-induced polyethylene microbeads were investigated by IR, thermal analysis (TGA/DSC), and SEM, respectively. Subsequently, the various amine groups such as diethylamine. diethylenetriamine, triethylamine, triethylenetetramine, and 1,6-hexanediamine were induced onto the epoxy group in polyethylene microbead. Finally, cyclodextrin glucanotransferase were immobilized onto polyethylene microbead with various amines under the various experimental conditions, such as pH, amin content, immobilization time, and etc. The activity of CGTase-immobilized polyethylene microbead was determined by Phenolphthein method. The production of the cyclodextrins from starch is in progress

  5. Antihistamines block radiation-induced increased intestinal blood flow in canines

    Energy Technology Data Exchange (ETDEWEB)

    Cockerham, L.G.; Doyle, T.F.; Donlon, M.A.; Gossett-Hagerman, C.J.

    1985-06-01

    Radiation-induced systemic hypotension is accompanied by increased intestinal blood flow (IBF) and an increased hematocrit (HCT) in dogs. Histamine infusion leads to increased IBF and intestinal edema with consequent secretion of fluid into the intestinal lumen. This study was performed to determine whether these effects could be diminished by prior administration of H1 and H2 histamine blockers. Dogs were given an iv infusion of mepyramine (0.5 mg/min) and cimetidine (0.25 mg/min) for 1 hr before and for 1 hr after radiation (H1 and H2 blockers, respectively). Mean systemic arterial blood pressure (MBP), IBF, and HCT were monitored for 2 hr. Systemic plasma histamine levels were determined simultaneously. Data obtained indicated that the H1 and H2 blockers, given simultaneously, were successful in blocking the increased IBF and the increased HCT seen after 100 Gy, whole-body, gamma radiation. However, the postradiation hypotension was only somewhat affected, with the MBP falling to a level 28% below the preradiation level. Plasma histamine levels reached a sharp peak, as much as 20% above baseline, at 4 min postradiation. These findings implicate histamine in the radiation-induced increase in IBF and HCT but not for the gradual decrease in postradiation blood pressure.

  6. Antihistamines block radiation-induced increased intestinal blood flow in canines

    Energy Technology Data Exchange (ETDEWEB)

    Cockerham, L.G.; Doyle, T.F.; Donlon, M.A.; Gossett-Hagerman, C.J.

    1985-01-01

    Radiation-induced systemic hypotension is accompanied by increased intestinal blood flow (IBF) and an increased hematocrit (HCT) in dogs. Histamine infusion leads to increased IBF and intestinal edema with consequent secretion of fluid into the intestinal lumen. This study was performed to determine whether these effects could be diminished by prior administration of H/sub 1/ and H/sub 2/ histamine blockers. Dogs were given an iv infusion of mepyramine (0.5 mg/min) and cimetidine (0.25 mg/min) for 1 hr before and for 1 hr after radiation (H sub 1 and H sub 2 blockers, respectively). Mean systemic arterial blood pressure (MBP), IBF, and HCT were monitored for 2 hr. Systematic plasma histamine levels were determined simultaneously. Data obtained indicated that the H sub 1 and H sub 2 blockers, given simultaneously, were successful in blocking the increased IBF and the increased HCT seen after 100 Gy, whole-body, gamma radiation. However, the postradiation hypotension was only somewhat affected, with the MBP falling to a level 28% below the preradiation level. Plasma histamine levels reached a sharp peak, as much as 20% above baseline, at 4 min postradiation. These findings implicate histamine in the radiation-induced increase in IBF and HCT but not for the gradual decrease in postradiation blood pressure. (Author)

  7. Increased Susceptibility of Radiation-Induced Intestinal Apoptosis in SMP30 KO Mice

    Directory of Open Access Journals (Sweden)

    Moon-Jung Goo

    2013-05-01

    Full Text Available Recently, senescence marker protein-30 (SMP30 knockout (KO mice have been reported to be susceptible to apoptosis, however, the role of SMP30 has not been characterized in the small intestine. The aim of the present study is to investigate the role of SMP30 in the process of spontaneous and γ-radiation-induced apoptosis in mouse small intestine. Eight-week-old male wild-type (WT mice and SMP30 KO mice were examined after exposure to 0, 1, 3, 5, and 9 Gy of γ-radiation. Apoptosis in the crypts of the small intestine increased in the 0 to 5 Gy radiated SMP30 KO and WT mice. Radiation-induced apoptosis and the BAX/Bcl-2 ratio in the SMP30 KO mice were significantly increased in comparison to each identically treated group of WT mice (p 0.05, indicating that increased apoptosis of crypt cells of SMP30 KO by irradiation can be associated with SMP30 depletion. These results suggested that SMP30 might be involved in overriding the apoptotic homeostatic mechanism in response to DNA damage.

  8. Lack of EGCG Effects on Radiation-Induced Apoptosis of Mice Splenocytes

    International Nuclear Information System (INIS)

    The modification of radiation-induced apoptosis by EGCG, known as antioxidants or oxidants, was studied in mice spleens irradiated with a lethal dose. Materials and Methods: Male C57BL/6 mice were divided into control, irradiation-only, and EGCG (100 mg/kg i.p. 1 h before irradiation) pretreatment groups. The mice were irradiated with a single whole-body dose of 7 Gy. The apoptosis in the spleens after irradiation of the lethal dose were analyzed by TUNEL assay. In addition, the expression levels of the Bax and Bcl-2 proteins were quantified using a Western blotting method. Results: The induction of apoptosis was detected in the splenic white pulp. The highest level of apoptosis was detected at 8 hours after irradiation. No significant difference was identified by the apoptotic index (53.9% vs. 52.1%, p=0.328) and relative Bax protein expression (0.86 vs. 0.81, p=0.335), between the irradiation-only and EGCG pretreatment group, respectively. However, a lower Bax/Bcl-2 ratio (1.64 vs. 0.97, p=0.037) and higher relative expression level of Bcl-2 protein (0.57 vs. 0.82, p=0.037) was measured in the EGCG pretreatment group. Conclusion: The EGCG pretreatment neither decreased the radiation-induced apoptosis in mice splenocytes, nor induced additional apoptosis

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

    International Nuclear Information System (INIS)

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

  10. Radiation-induced grafting of sweet sorghum stalk for copper(II) removal from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Jing; Hu, Jun [Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084 (China); Wang, Jianlong, E-mail: wangjl@mail.tsinghua.edu.cn [Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084 (China); Key Laboratory of Advanced Reactor Engineering and Safety, Ministry of Education, Tsinghua University, Beijing 100084 (China)

    2013-11-15

    Highlights: • Radiation-induced grafting was used to modify the stalk. • Cellulose, hemicellulose and lignin participated in grafting reaction. • Both the structure and composition of stalk had influence on grafting. • The sorption capacity of the grafted stalk increased about five times. -- Abstract: The influence of main components (cellulose, hemicellulose and lignin) of the sweet sorghum stalk on radiation-induced grafting reaction and adsorption of copper from aqueous solution was investigated. Sweet sorghum stalk was grafted with acrylic acid induced by γ-irradiation. The results showed that the grafted stalk contained 1.6 mmol/g carboxyl groups, and its maximal adsorption capacity was 13.32 mg/g. The cellulose, hemicellulose and lignin of the raw materials were confirmed to involve in grafting reaction through comparing the grafting yield and the structure of the grafted materials. Both the structure and the composition of the sweet sorghum stalk had influence on the grafting reaction and adsorption capacity. The adsorption capacity of the grafted sweet sorghum stalk increased about five times, and the adsorption isotherm of the grafted materials conformed to the Langmuir model. The main mechanism for copper adsorption involved in ion exchange.

  11. The role of alveolar epithelium in radiation-induced lung injury.

    Directory of Open Access Journals (Sweden)

    Celine Almeida

    Full Text Available Pneumonitis and fibrosis are major lung complications of irradiating thoracic malignancies. In the current study, we determined the effect of thoracic irradiation on the lungs of FVB/N mice. Survival data showed a dose-dependent increase in morbidity following thoracic irradiation with single (11-13 Gy and fractionated doses (24-36 Gy of (137Cs γ-rays. Histological examination showed a thickening of vessel walls, accumulation of inflammatory cells, collagen deposition, and regional fibrosis in the lungs 14 weeks after a single 12 Gy dose and a fractionated 30 Gy dose; this damage was also seen 5 months after a fractionated 24 Gy dose. After both single and fractionated doses, i] aquaporin-5 was markedly decreased, ii] E-cadherin was reduced and iii] prosurfactant Protein C (pro-SP-c, the number of pro-SP-c(+ cells and vimentin expression were increased in the lungs. Immunofluorescence analysis revealed co-localization of pro-SP-c and α-smooth muscle actin in the alveoli after a single dose of 12 Gy. These data suggest that, i] the FVB/N mouse strain is sensitive to thoracic radiation ii] aquaporin-5, E-cadherin, and pro-SP-c may serve as sensitive indicators of radiation-induced lung injury; and iii] the epithelial-to-mesenchymal transition may play an important role in the development of radiation-induced lung fibrosis.

  12. The effect of vitamin D prophylaxis on radiation induced pulmonary damage

    International Nuclear Information System (INIS)

    Vitamin D has a selective radio and chemosensitizing effect on tumor cells. In vitro and in vivo studies have shown that vitamin D inhibits collagen gel construction, induces type II pneumocyte proliferation and surfactant synthesis in the lungs, and decreases vascular permeability caused by radiation. The aim of this experimental study was to determine if vitamin D has a protective effect against radiation-induced pulmonary damage. Adult Wistar rats were divided into 4 groups. Group 1 was comprised of control animals. Group 2, which was administered 0.25 μg/kg/day of vitamin D3 for 8 weeks, was the vitamin D control group. Rats in groups 3 and 4 were given 20 Gy right hemithorax radiotherapy, and in addition group 4 was given vitamin D3 treatment, which began the day before the radiotherapy and continued for 8 weeks. At the 8th and the 12th weeks of the study 4 rats from each group were sacrificed. Right lungs were dissected for light and electron microscopic study. The electron microscopy examinations revealed statistically significant differences between group 3 and 4, and in group 4 there was less interstitial inflammation and collagen deposition, and the alveolar structure and the cells lining the alveolar walls were protected. These results confirm that vitamin D has a protective effect against radiation-induced pulmonary toxicity. These findings should be evaluated with further clinical studies. (author)

  13. A biological approach to the interspecies prediction of radiation-induced mortality risk

    International Nuclear Information System (INIS)

    Evolutionary explanations for why sexually reproducing organisms grow old suggest that the forces of natural selection affect the ages when diseases occur that are subject to a genetic influence (referred to here as intrinsic diseases). When extended to the population level for a species, this logic leads to the general prediction that age-specific death rates from intrinsic causes should begin to rise as the force of selection wanes once the characteristic age of sexual maturity is attained. Results consistent with these predictions have been found for laboratory mice, beagles, and humans where, after adjusting for differences in life span, it was demonstrated that these species share a common age pattern of mortality for intrinsic causes of death. In quantitative models used to predict radiation-induced mortality, risks are often expressed as multiples of those observed in a control population. A control population, however, is an aging population. As such, mortality risks related to exposure must be interpreted relative to the age-specific risk of death associated with aging. Given the previous success in making interspecies predictions of age-related mortality, the purpose of this study was to determine whether radiation-induced mortality observed in one species could also be predicted quantitatively from a model used to describe the mortality consequences of exposure to radiation in a different species. Mortality data for B6CF1 mice and beagles exposed to 60Co γ-rays for the duration of life were used for analysis

  14. Radiation-induced electrical degradation experiments in the Japan materials testing reactor

    Science.gov (United States)

    Farnum, Eugene H.; Shikama, Tatsuo; Narui, Minoru; Sagawa, Tsutomu; Scarborough, Kent

    1996-02-01

    An experiment to measure radiation-induced electrical degradation (RIED) in a sapphire sample and in three MgO-insulated cables was conducted at the JMTR light water reactor. The materials were irradiated at about 260°C to a fluence of 3 × 1024 n/m 2 ( E > 1 MeV) with an applied DC electric field between 100 kV/m and 500 kV/m. Even though the results for the sapphire sample are somewhat ambiguous because of an unexplained offset current of about 0.6 μA substantial degradation was not observed in the sapphire: instead, radiation-induced conductivity (RIC) seemed to decrease slightly during the experiment. Substantial increase in leakage current, that increased with applied electric field, occurred in the MgO-insulated cables. This increased conductivity disappeared when the reactor was shut down and sample temperature returned to ambient. However, the physical degradation apparently remained in the material while the reactor was off because restarting the irradiation brought the conductivity back to its previous, degraded, reactor-on value. This effect is different from the RIED effect reported by Hodgson but is similar to previous results reported by Shikama et al. Considerable data were taken to determine the sample temperature and leakage currents during the irradiation.

  15. Harnessing a radiation inducible promoter of Deinococcus radiodurans for enhanced precipitation of uranium.

    Science.gov (United States)

    Misra, Chitra Seetharam; Mukhopadhyaya, Rita; Apte, Shree Kumar

    2014-11-10

    Bioremediation is an attractive option for the treatment of radioactive waste. We provide a proof of principle for augmentation of uranium bioprecipitation using the radiation inducible promoter, Pssb from Deinococcus radiodurans. Recombinant cells of D. radiodurans carrying acid phosphatase gene, phoN under the regulation of Pssb when exposed to 7 kGy gamma radiation at two different dose rates of 56.8 Gy/min and 4 Gy/min, showed 8-9 fold increase in acid phosphatase activity. Highest whole cell PhoN activity was obtained after 2h in post irradiation recovery following 8 kGy of high dose rate radiation. Such cells showed faster removal of high concentrations of uranium than recombinant cells expressing PhoN under a radiation non-inducible deinococcal promoter, PgroESL and could precipitate uranium even after continuous exposure to 0.6 Gy/min gamma radiation for 10 days. Radiation induced recombinant D. radiodurans cells when lyophilized retained high levels of PhoN activity and precipitated uranium efficiently. These results highlight the importance of using a suitable promoter for removal of radionuclides from solution.

  16. Sorafenib Enhances Radiation-Induced Apoptosis in Hepatocellular Carcinoma by Inhibiting STAT3

    International Nuclear Information System (INIS)

    Purpose: Hepatocellular carcinoma (HCC) is one of the most common and lethal human malignancies. Lack of efficient therapy for advanced HCC is a pressing problem worldwide. This study aimed to determine the efficacy and mechanism of combined sorafenib and radiation therapy treatment for HCC. Methods and Materials: HCC cell lines (PLC5, Huh-7, Sk-Hep1, and Hep3B) were treated with sorafenib, radiation, or both, and apoptosis and signal transduction were analyzed. Results: All 4 HCC cell lines showed resistance to radiation-induced apoptosis; however, this resistance could be reversed in the presence of sorafenib. Inhibition of phospho-STAT3 was found in cells treated with sorafenib or sorafenib plus radiation and subsequently reduced the expression levels of STAT3-related proteins, Mcl-1, cyclin D1, and survivin. Silencing STAT3 by RNA interference overcame apoptotic resistance to radiation in HCC cells, and the ectopic expression of STAT3 in HCC cells abolished the radiosensitizing effect of sorafenib. Moreover, sorafenib plus radiation significantly suppressed PLC5 xenograft tumor growth. Conclusions: These results indicate that sorafenib sensitizes resistant HCC cells to radiation-induced apoptosis via downregulating phosphorylation of STAT3 in vitro and in vivo

  17. Radiation-induced crosslinking and post-processing of poly(L-lactic acid) composite

    Energy Technology Data Exchange (ETDEWEB)

    Nagasawa, Naotsugu, E-mail: nagasawa.naotsugu@jaea.go.j [Japan Atomic Energy Agency (JAEA), Quantum Beam Science Directorate, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Kasai, Noboru; Yagi, Toshiaki; Yoshii, Fumio; Tamada, Masao [Japan Atomic Energy Agency (JAEA), Quantum Beam Science Directorate, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

    2011-02-15

    Poly(L-lactic acid), PLLA, was irradiated using electron beams (EBs) in the presence of triallyl isocyanurate (TAIC) at 5% concentration as crosslinking agent. The crosslinked PLLA obtained has heat resistance, as demonstrated by retention of its original shape at glass transition temperature or even higher than 200 {sup o}C. As an application of this fact, crosslinked PLLA is applied in spectacle lens to prevent shape deformation of eyeglass frames in displaying and transporting. However, in this application to lens, it is not enough to improve the thermal deformation of PLLA under stress at 70 {sup o}C. Radiation-induced crosslinking of a PLLA/silicon dioxide (SiO{sub 2}) composite with TAIC and post-processing of the crosslinked PLLA composite by heating were further investigated from the viewpoint of thermal deformation. The PLLA materials have several advantages such as high heat resistance and transparency. It is therefore proved that the combination of radiation-induced crosslinking, composition of SiO{sub 2} and post-heating is beneficial for expanding the applications of PLLA.

  18. Radiation-induced destruction of hydroxyl-containing amino acids and dipeptides

    Science.gov (United States)

    Sladkova, А. А.; Sosnovskaya, А. А.; Edimecheva, I. P.; Shadyro, О. I.

    2012-12-01

    The yields of molecular products resulting from radiolysis of hydroxyl-containing amino acids and dipeptides under various conditions were determined. The possibility of a new radiation-induced destruction pathway has been shown for serine and threonine, as well as for the dipeptides having residues of these amino acids at the N-terminal part of the respective molecule. This process includes formation of N-centered radicals from the starting molecules followed by their decomposition with elimination of side substituents. On radiolysis, serine and threonine were also shown to undergo free-radical destruction to form acetaldehyde and acetone, respectively. A mechanism has been proposed including consecutive stages of fragmentation of α-hydroxyl-containing carbon-centered radicals with elimination of ammonia and decomposition of the secondary radicals with elimination of CO2. The yields of CO2 obtained on radiolysis of serine and threonine were significantly higher (except for solutions at pH 12) than those for alanine and valine, which have no hydroxyl groups in their structures. The obtained data indicate that the hydroxyl-containing amino acids occupy a special place among other amino acids as regards the variety of radiation-induced reactions which they may undergo due to their structural features.

  19. Protective role of garlic against gamma radiation induced histological and histochemical changes in rat liver

    International Nuclear Information System (INIS)

    The present work was planned to evaluate the radioprotective effect of garlic (Allium sativum) against the hazardous action of gamma radiation on liver of rat one and ten days post-exposure. Garlic was orally administered (100 mg/ kg body wt) to rats daily for two weeks before exposure to single dose whole body gamma-irradiation (5Gy). The results showed that exposure of rats to gamma- irradiation caused massive portal infiltration with inflammatory cells, dilatation of blood sinusoids, an increase in the number of Kupffer cells, vacuolation of some hepatocytes as well as pyknosis and karyolysis of hepatic nuclei in the liver tissue. Histochemical examination of liver one day post- irradiation illustrated weak to moderate glycogen particles. While, on ten days post-irradiation, a strong activity for glycogen was detected. The disturbance in carbohydrate metabolism is closely related to the radiation induced histological damage in the liver tissue. Administration of garlic for 2 weeks pre-irradiation reduced the radiation induced histopathological changes and showed marked protection against the tissue damaging effect of radiation. It could be concluded that treatment of rats with garlic before exposure to gamma-irradiation offered a noticeable radioprotective effect of the studied organ

  20. Tissue specific promoters improve the localization of radiation-inducible gene expression

    International Nuclear Information System (INIS)

    Purpose: Site-specific activation of gene expression can be achieved by the use of a promoter that is induced by physical agents such as x-rays. The purpose of the present study was to determine whether site-specific activation of gene therapy can also be achieved within the vascular endothelium by use of radiation-inducible promoters. We studied induction of promoter-reporter gene constructs using previously identified radiation-promoters from c-jun, c-fos, Egr-1, ICAM-1, ELAM-1 after transfection into in the vascular endothelium. Methods: The following radiation-inducible genetic constructs were created: The ELAM-1 promoter fragment was cloned into pOGH to obtain the pE-sel(-587 +35)GH reporter construct. The ICAM-1 promoter fragment (-1162/+1) was cloned upstream of the CAT coding region of the pCAT-plasmid (Promega) after removal of the SV40 promoter by Bgl2/Stu1 digestion to create the pBS-CAT plasmid. The 132 to +170 bp segment of the 5' untranslated region of the c-jun promoter was cloned to the CAT reporter gene to create the -132/+170 cjun-CAT. The Egr-1 promoter fragment (-425/+75) was cloned upstream of the CAT coding region to create the pE425-CAT plasmid. Tandem repeats of the AP-1 binding site were cloned upstream of the CAT coding region (3 xTRE-CAT). Tandem repeats of the Egr binding site (EBS) were cloned upstream of the CAT coding region (EBS-CAT). Human vascular endothelial cells from both large vessel and small vessel origin (HUVEC and HMEC), as well as human tumor cell lines were transfected with plasmids -132/+170 cjun-CAT, pE425-CAT, 3 xTRE-CAT, EBS-CAT, pE-sel-GH and pBS-CAT by use of liposomes. Humor tumor cell lines included SQ20B (squamous), RIT3 (sarcoma), and HL525 (leukemia). Each plasmid was cotransfected with a plasmid containing a CMV promoter linked to the LacZ gene (1 μg). Transfected cells were treated with mock irradiation or x-rays. Cell extracts were assayed for reporter gene expression. Results: Radiation-induced gene

  1. Chromosomal Abnormalities in ADHD

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2002-07-01

    Full Text Available The prevalence of fragile X syndrome, velocardiofacial syndrome (VCFS, and other cytogenetic abnormalities among 100 children (64 boys with combined type ADHD and normal intelligence was assessed at the NIMH and Georgetown University Medical Center.

  2. Chromosomal abnormalities and autism

    Directory of Open Access Journals (Sweden)

    Farida El-Baz

    2016-01-01

    Conclusion: Chromosomal abnormalities were not detected in the studied autistic children, and so the relation between the genetics and autism still needs further work up with different study methods and techniques.

  3. The suppression of radiation-induced NF-κB activity by dexamethasone correlates with increased cell death in vivo

    International Nuclear Information System (INIS)

    In this study, we show that dexamethasone treatment increases ionizing radiation-induced cell death by inducing the inhibitory κBα (IκBα) pathway in mice. The effect of dexamethasone on radiation-induced cell death was assessed by changes in total spleen cellularity and bone marrow colony-forming unit-granulocyte-macrophage (CFU-GM) contents after total body irradiation. While in vivo treatment of mice with dexamethasone alone (1 mg/kg/day, for 2 days) failed to elicit cell death in spleen cells, the combined treatment with dexamethasone (1 mg/kg/day, for 2 days) and γ-rays (1 or 5 Gy) caused a 50-80% reduction in total cellularity in spleen and CFU-GM contents in bone marrow. These results demonstrate that dexamethasone has a synergistic effect on radiation-induced cellular damages in vivo. Immunoblot analysis showed that dexamethasone treatment significantly increases IκBα expression in the spleens of irradiated mice. In addition, the dexamethasone treatment significantly reduced radiation-induced nuclear translocation of the nucleus factor-κB in the spleens of irradiated mice. These results indicate that dexamethasone treatment in vivo may increase radiation-induced cell damages by increasing IκBα expression in hematopoietic organs such as spleen and bone marrow

  4. Abnormal protein aggregationand neurodegenerativediseases

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Abnormal protein aggregation or amyloid is the major cause ofmany neurodegenerative disorders. The present review focuses on the correlation between sequence and structure features of proteins related to the diseases and abnormal protein aggregation. Recent progress has improved our knowledge on understand-ing the mechanism of amyloid formation. We suggest a nucleation model for ordered protein aggregation, which can also explain pathogenesis mechanisms of these neurodegenerative diseases in vivo.

  5. Anti-inflammatory effects of tanshinone IIA on radiation-induced microglia BV-2 cells inflammatory response

    DEFF Research Database (Denmark)

    Dong, Xiaorong; Dong, Jihua; Zhang, Ruiguang;

    2009-01-01

    AIM: The aim of this study was to explore the inhibitory effects of Tanshinone II(A) on the production of proinflammation cytokines in radiation-stimulated microglia. METHODS: Microglia cells were treated with 2, 4, 8, 16, and 32 Gy of irradiation or sham-irradiated in the presence or absence of 1.......0 microg/mL of Tanshinone II(A). The effects of Tanshinone II(A) on radiation-induced proinflammatory cytokines were evaluated by real-time polymerase chain reaction; the expression level of nuclear factor (NF-kappabeta) p65 in cytoplasm and nucleus was measured by Western blot. Immunofluorescence staining...... and confocal microscopy analysis were applied to detect the expression of gamma-H2AX and p65 postirradiation. RESULTS: Radiation-induced release of proinflammatory cytokines in BV-2 cells was detectable after irradiation. Tanshinone II(A) decreased the radiation-induced release of proinflammatory cytokines...

  6. Protection of radiation induced DNA and membrane damages by total triterpenes isolated from Ganoderma lucidum (Fr.) P. Karst.

    Science.gov (United States)

    Smina, T P; Maurya, D K; Devasagayam, T P A; Janardhanan, K K

    2015-05-25

    The total triterpenes isolated from the fruiting bodies of Ganoderma lucidum was examined for its potential to prevent γ-radiation induced membrane damage in rat liver mitochondria and microsomes. The effects of total triterpenes on γ-radiation-induced DNA strand breaks in pBR 322 plasmid DNA in vitro and human peripheral blood lymphocytes ex vivo were evaluated. The protective effect of total triterpenes against γ-radiation-induced micronuclei formations in mice bone marrow cells in vivo were also evaluated. The results indicated the significant effectiveness of Ganoderma triterpenes in protecting the DNA and membrane damages consequent to the hazardous effects of radiation. The findings suggest the potential use of Ganoderma triterpenes in radio therapy.

  7. Radiation-induced inflammatory markers of brain injury are modulated by PPARdelta activation in vitro and in vivo

    Science.gov (United States)

    Schnegg, Caroline Isabel

    As a result of improvements in cancer therapy and health care, the population of long-term cancer survivors is growing. For these approximately 12 million long-term cancer survivors, brain metastases are a significant risk. Fractionated partial or whole-brain irradiation (fWBI) is often required to treat both primary and metastatic brain cancer. Radiation-induced normal tissue injury, including progressive cognitive impairment, however, can significantly affect the well-being of the approximately 200,000 patients who receive these treatments each year. Recent reports indicate that radiation-induced brain injury is associated with chronic inflammatory and oxidative stress responses, as well as increased microglial activation in the brain. Anti-inflammatory drugs may, therefore, be a beneficial therapy to mitigate radiation-induced brain injury. We hypothesized that activation of peroxisomal proliferator activated receptor delta (PPARō) would prevent or ameliorate radiation-induced brain injury, including cognitive impairment, in part, by alleviating inflammatory responses in microglia. For our in vitro studies, we hypothesized that PPARō activation would prevent the radiation-induced inflammatory response in microglia following irradiation. Incubating BV-2 murine microglial cells with the (PPAR)ō agonist, L-165041, prevented the radiation-induced increase in: i) intracellular ROS generation, ii) Cox-2 and MCP-1 expression, and iii) IL-1β and TNF-α message levels. This occured, in part, through PPARō-mediated modulation of stress activated kinases and proinflammatory transcription factors. PPARō inhibited NF-κB via transrepression by physically interacting with the p65 subunit, and prevented activation of the PKCα/MEK1/2/ERK1/2/AP-1 pathway by inhibiting the radiation-induced increase in intracellular ROS generation. These data support the hypothesis that PPARō activation can modulate the radiation-induced oxidative stress and inflammatory responses in

  8. Side effects and opioid addiction in radiation-induced mucositis pain control in head and neck cancer

    International Nuclear Information System (INIS)

    Radiation therapy in head and neck malignancy may trigger mucositis poorly controlled by nonsteroidal antiinflammatory drugs (NSAIDs). Having already reported early opioid efficacy in radiation-induced mucositis pain in head and neck cancer, we discuss whether this resulted in severe side effects and opioid addiction. Of 11 persons (26.2%) with nausea, 3 could not tolerate opioid. Of 33 (78.6%) with constipation, all were controlled by purgatives. Seven had mild sleepiness. None had severe opioid side effects in radiation-induced mucositis pain treatment, but I showed opioid dependence after 128-days opioid administration. While opioid administration in radiation-induced mucositis pain may not cause addiction, lomg-term opioid use should be carefully monitored. (author)

  9. The Role of DNA Methylation Changes in Radiation-Induced Bystander Effects in cranial irradiated Mice

    Science.gov (United States)

    Zhang, Meng; Sun, Yeqing; Xue, Bei; Wang, Xinwen; Wang, Jiawen

    2016-07-01

    Heavy-ion radiation could lead to bystander effect in neighboring non-hit cells by signals released from directly-irradiated cells. The exact mechanisms of radiation-induced bystander effect in distant organ remain obscure, yet accumulating evidence points to the role of DNA methylation changes in bystander effect. To identify the molecular mechanism that underlies bystander effects of heavy-ion radiation, the male Balb/c and C57BL mice were cranial exposed to 40, 200, 2000mGy dose of carbon heavy-ion radiation, while the rest of the animal body was shielded. The γH2AX foci as the DNA damage biomarker in directly irradiation organ ear and the distant organ liver were detected on 0, 1, 2, 6, 12 and 24h after radiation, respectively. Methylation-sensitive amplifcation polymorphism (MSAP) was used to monitor the level of polymorphic genomic DNA methylation changed with dose and time effects. The results show that cranial irradiated mice could induce the γH2AX foci and genomic DNA methylation changes significantly in both the directly irradiation organ ear and the distant organ liver. The percent of DNA methylation changes were time-dependent and tissue-specific. Demethylation polymorphism rate were highest separately at 1 h in 200 mGy and 6 h in 2000 mGy after irradiation in ear. The global DNA methylation changes tended to occur in the CG sites. We also found that the numbers of γH2AX foci and the 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 radiation induced bystander effects in vivo. Keywords: Heavy-ion radiation; Bystander effect; DNA methylation; γH2

  10. The use of radiation-induced graft polymerization for modification of polymer track membranes

    International Nuclear Information System (INIS)

    Track membranes (TM) made of poly(ethylene terephtalate) (PET) and polypropylene (PP) films have a number of peculiarities as compared with other ones. They have high mechanical strength at a low thickness, narrow pore size distribution, low content of extractables. However, TM have some disadvantages such as low chemical resistance in alkaline media (PET TM), the low water flow rate due to the hydrophobic nature of their surface. The use of radiation-induced graft polymerization makes it possible to improve the basic characteristics of TM. In this communication our results on the modification of PET and PP TM are presented. The modified membranes were prepared by radiation-induced graft polymerization from the liquid phase. Three methods of grafting were used: (a) the direct method in argon atmosphere; (b) the pre-irradiation of TM in air followed by grafting in argon atmosphere; (c) pre-irradiation in vacuum followed by grafting in vacuum without contacting oxygen. The aim of the work was to investigate some properties of TM modified by grafted poly(methylvinyl pyridine) (PMVP) and poly(N-isopropylacrylamide) (PNIPAAM). It was shown that the modification of TM with hydrophilic polymer results in the growth of the water flow rate. In the past few years many works have been devoted to the synthesis of new polymers - the so-called 'intelligent' materials - such as PNIPAAM. However, it is very difficult to make thin membranes of this polymer. Recently, it has been proposed to manufacture composite membranes by grafting stimulus-responsive polymers onto TM. Following this principle, we prepared thermosensitive membranes by the radiation-induced graft polymerization of N-isopropylacrylamide (NIPAAM) onto PET TM. PET TM with the pore size of about 1 μm and pore density of 106 cm-2 were first inserted into a solution of NIPAAM containing inhibitor of homopolymerization (CuCl2) and then exposed to the γ-rays from a 60Co source. The transport properties of the grafted TM

  11. The use of radiation-induced graft polymerization for modification of polymer track membranes

    Science.gov (United States)

    Shtanko, N. I.; Kabanov, V. Ya.; Apel, P. Yu.; Yoshida, M.

    1999-05-01

    Track membranes (TM) made of poly(ethylene terephtalate) (PET) and polypropylene (PP) films have a number of peculiarities as compared with other ones. They have high mechanical strength at a low thickness, narrow pore size distribution, low content of extractables. However, TM have some disadvantages such as low chemical resistance in alkaline media (PET TM), the low water flow rate due to the hydrophobic nature of their surface. The use of radiation-induced graft polymerization makes it possible to improve the basic characteristics of TM. In this communication our results on the modification of PET and PP TM are presented. The modified membranes were prepared by radiation-induced graft polymerization from the liquid phase. Three methods of grafting were used: (a) the direct method in argon atmosphere; (b) the pre-irradiation of TM in air followed by grafting in argon atmosphere; (c) pre-irradiation in vacuum followed by grafting in vacuum without contacting oxygen. The aim of the work was to investigate some properties of TM modified by grafted poly(methylvinyl pyridine) (PMVP) and poly(N-isopropylacrylamide) (PNIPAAM). It was shown that the modification of TM with hydrophilic polymer results in the growth of the water flow rate. In the past few years many works have been devoted to the synthesis of new polymers - the so-called "intelligent" materials - such as PNIPAAM. However, it is very difficult to make thin membranes of this polymer. Recently, it has been proposed to manufacture composite membranes by grafting stimulus-responsive polymers onto TM. Following this principle, we prepared thermosensitive membranes by the radiation-induced graft polymerization of N-isopropylacrylamide (NIPAAM) onto PET TM. PET TM with the pore size of about 1 μm and pore density of 10 6 cm -2 were first inserted into a solution of NIPAAM containing inhibitor of homopolymerization (CuCl 2) and then exposed to the γ-rays from a 60Co source. The transport properties of the grafted

  12. Therapy and prophylaxis of acute and late radiation-induced sequelae of the esophagus

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, F.B.; Geinitz, H.; Feldmann, H.J. [Klinik und Poliklinik fuer Strahlentherapie und Radiologische Onkologie, Klinikum rechts der Isar, Muenchen (Germany)

    1998-11-01

    Background: Radiation-induced esophagitis is a frequent acute side effect in curative and palliative radiotherapy of thoracal and cervical tumors. Late reactions are rare but might be severe. Methods: A resarch for reports on prophylactic and supportive therapies of radiation-induced esophagitis was performed (Medline, Cancerlit, and others). Results: Nutrition must be ensured and symptomatic relief of sequelae is important, especially in the case of dysphagia. The latter can be improved by topic or systemic analgetics. If esophageal spasm occurs, calcium antagonists might help. In case of gastro-esophageal reflux proton pump inhibitors should be used. There is no effective prophylactic measure for radiation esophagitis. Late side effects with clinical relevance are rare in conventional radiotherapy. Chronic ulcera, fistula or stenosis may develop. Before any treatment, a tumor infiltration of the esophagus should be excluded by biopsy. This can lead more often to late complications than radiation therapy itself. Nutrition should be ensured by endoscopic dilation, stent-implantation, or endoscopic percutaneous gastrostomy. Local injection of steroids might be used to avoid an early restenosis. Conclusions: An intensive symptomatic therapy of acute esophagitis is reasonable. Effective prophylaxis do not exist. Late radiation induced sequelae is rare. Therefore, a tumor recurrenc e should be excluded in cases of dysphagia. Securing nutrition by PEG, stent, or port is well in the fore. (orig.) [Deutsch] Hintergrund: Die radiogene Oesophagitis ist eine haeufige akute Nebenwirkung bei kurativen wie palliativen Bestrahlungen thorakaler und zervikaler Tumoren. Spaete Gewebereaktionen sind selten, koennen aber schwerwiegend sein. Methode: Es wurde eine Literaturrecherche nach prophylaktischen und supportiven Therapien der radiogen verursachten Oesophagitis durchgefuehrt (Medline, Cancerlit und andere). Ergebnisse: Therapeutisch stehen die Sicherung der Ernaehrung und die

  13. Effectiveness of triclosan in the management of radiation-induced oral mucositis: A randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Satheeshkumar P

    2010-01-01

    Full Text Available Introduction: Oral care in cancer patients is an important aspect in the quality of life of patients undergoing cancer therpay. Mucositis, trismus, salivary gland dysfunction are the main complications of the cancer therapy, which lead to long-term comlications such as radiation caries, poor oral hygiene and osteoradionecrosis. A timely oral evaluation and intervention in these patients can reduce the severity of the potential complications. Triclosan is an antibacterial agent widely used in periodontal therapy, the effectiveness of triclosan in the management of radiation induced oral mucositis is evaluated here. Aims: 1 To determine the effectiveness of triclosan in the management of radiation-induced oral mucositis. 2 To compare the effectiveness of triclosan mouth rinse with conventional sodium bicarbonate mouth rinse. Materials and Methods: Twenty-four patients who underwent radiation therapy for oral cancer and subsequently developed oral mucositis were included in the study. They were randomly allocated into two groups on noticing grade I mucositis (erythema. The study group was advised to use triclosan mouthwash containing triclosan 0.03% W/V and sodium bicarbonate 2 mg mouth wash for the control group. A weekly follow-up evaluation of body weight, food intake, pain and grading of mucositis were made during the radiation treatment period and post radiation treatment period. Results: Both the groups were statistically identical. All the 24 patients in both the groups passed through grade 3 mucositis on the last day of radiotherapy. However, 10 patients in the control group and only one patient in the study group entered to grade 4 mucositis. A definite change was noticed in the severity of the mucositis, food intake and weight loss. The control group took more than 45 days to resolve while the study group took only less than 28 days. Discussion: The results of the study were evaluated and tried to formulate a hypothesis so as to explain

  14. Individual repair of radiation-induced DNA double-strand breaks in lymphocytes. Implications for radiation-induced dermatitis in breast cancer

    International Nuclear Information System (INIS)

    Purpose: Adjuvant 'whole breast radiotherapy' (WBRT) is the standard of care after breast conserving surgery in women with breast cancer. Throughout different cancer stages the addition of WBRT leads to significantly improved rates of freedom from local failure and overall survival. WBRT is generally well tolerated. A 5-10%-rate of severe acute or long-term side effects is commonly observed. For both radiation-mediated tumor-cell-elimination and induction of side effects, DNA-double-strand-breaks (DSB) presumably play the decisive role. The intensity of normal tissue reactions in radiotherapy can, in part, be attributed to the intrinsic DSB repair-capacity. In this study in vivo and in vitro experiments are carried through in order to assess DSB repair-kinetics in blood lymphocytes of women with breast cancer. These findings are to be correlated with the degree of radiation-induced normal tissue toxicity. Patients and Methods: Eighteen patients with breast cancer, in whom WBRT was indicated, were examined. A total WBRT dose of 50 Gy (single dose 2 Gy) with an additional boost-radiotherapy to the initial tumor-region to a total dose of 60-66 Gy was administered. DSB repair was determined by means of counting γ-H2AX foci in blood lymphocytes at predefined points in time, i.e. before and 0.5 h; 2.5 h; 5 h and 24 h after in vivo irradiation (1st fraction of WBRT) and before and 0.5 h; 2.5 h and 5 h after in vitro irradiation with increasing radiation doses in the range of 10 - 500 mGy. Acute normal tissue toxicity was scored on the basis of a modified RTOG-classification (main aspects were erythema and dry or moist skin desquamation). Results: DSB repair-halflife-times did not differ between patients with a higher or lower than average incidence of acute side effects. In patients with 'above average' side effects larger irradiation volumes were treated (volume surrounded by the 50%-isodose). Adjusted for these, no single patients showed elevated residual γ-H2AX foci

  15. Role of dual source CT perfusion imaging in the diagnosis of early radiation-induced lung injury%双源 CT灌注成像诊断早期放射性肺损伤的应用价值

    Institute of Scientific and Technical Information of China (English)

    潘利福; 邝平定

    2015-01-01

    Objective To examine the role of dual source CT perfusion imaging for early diagnosis of radiation -induced lung injury and to obtain scientific knowledge for early diagnosis of radiation induced lung injury .Method The level of dual source CT perfusion imaging perfusion values of the radiation-induced lung injury patients ( the experimental group , n=45 ) and that of the patients with no radiation-induced lung injury (the control group, n=45) was monitored.Meanwhile, the patients with radiation-induced lung injury were subjected to conventional CT examination .The sensitivity and accuracy of the two detection methods were then compared .Findings The values of lung tissue blood flow ( rrBF ) , relative blood volume ( rrBV) , relative blood capillary permeability ( chip) of the experimental group were significantly higher than those of the control group (P0.05).41 of the 45 patients of the experimental group were diagnosed as cases of radioactive lung injury.The diagnostic sensitivity and specificity were 91.1% and 97.78% respectively, which were significantly higher than those of the conventional CT technology (P<0.01).Conclusion Dual source CT perfusion imaging can display the changes after radiotherapy of lung hemodynamics and display early perfusion abnormalities in patients with radiation -induced lung injury.It can serve as an effective tool for early detection of radiation-induced lung injury .%目的:探讨双源CT灌注成像早期诊断放射性肺损伤的应用效果,为放射性肺损伤早期诊断提供依据。方法观察放射性肺损伤患者45例(观察组)和未发生放射性肺损伤患者45例(对照组)的双源CT灌注成像灌注值的水平,同时对放射性肺损伤患者采用常规的CT检查,比较两种检测方法的灵敏度和准确度。结果观察组肺组织相对血流量(rrBF)、相对血容量(rrBV)、相对毛细血管通透性(rrPS)均显著高于对照组(P<0.05);观察组45

  16. Amelioration of radiation-induced skin injury by adenovirus-mediated heme oxygenase-1 (HO-1) overexpression in rats

    International Nuclear Information System (INIS)

    Radiation-induced skin injury remains a serious concern for radiation therapy. Heme oxygenase-1 (HO-1), the rate-limiting enzyme in heme catabolism, has been reported to have potential antioxidant and anti-apoptotic properties. However, the role of HO-1 in radiation-induced skin damage remains unclear. This study aims to elucidate the effects of HO-1 on radiation-induced skin injury in rats. A control adenovirus (Ad-EGFP) and a recombinant adenovirus (Ad-HO1-EGFP) were constructed. Rats were irradiated to the buttock skin with a single dose of 45 Gy followed by a subcutaneous injection of PBS, 5 × 109 genomic copies of Ad-EGFP or Ad-HO1-EGFP (n = 8). After treatment, the skin MDA concentration, SOD activity and apoptosis were measured. The expression of antioxidant and pro-apoptotic genes was determined by RT-PCR and real-time PCR. Skin reactions were measured at regular intervals using the semi-quantitative skin injury score. Subcutaneous injection of Ad-HO1-EGFP infected both epidermal and dermal cells and could spread to the surrounding regions. Radiation exposure upregulated the transcription of the antioxidant enzyme genes, including SOD-1, GPx2 and endogenous HO-1. HO-1 overexpression decreased lipid peroxidation and inhibited the induction of ROS scavenging proteins. Moreover, HO-1 exerted an anti-apoptotic effect by suppressing FAS and FASL expression. Subcutaneous injection of Ad-HO1-EGFP demonstrated significant improvement in radiation-induced skin injury. The present study provides evidences for the protective role of HO-1 in alleviating radiation-induced skin damage in rats, which is helpful for the development of therapy for radiation-induced skin injury

  17. Measurement of 60CO gamma radiation induced attenuation in multimode step-index POF at 530 nm

    Directory of Open Access Journals (Sweden)

    Kovačević Milan S.

    2013-01-01

    Full Text Available As optical fibres are used ever more extensively in space applications, nuclear industry, medicine and high-energy physics experiments, it has become essential to investigate the influence of ionizing radiation on their characteristics. In this work, the radiation-induced attenuation at 530 nm is investigated experimentally in step-index multimode polymethyl-methacrylate plastic optical fibres exposed to low dose-rate gamma radiation. Cumulative doses ranged from 50 Gy to 500 Gy. The radiation induced attenuation has been empirically found to obey the power law RIA= aDb, where D is the total radiation dose and a and b are the constants determined by fitting.

  18. Chondrosarcoma arising within a radiation-induced osteochondroma several years following childhood total body irradiation: Case report

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Shuji [Kurume University Hospital, Department of Radiology, Fukuoka (Japan); Shen, Robert K. [Mayo Clinic, Department of Surgery, Rochester, MN (United States); Laack, Nadia N. [Mayo Clinic, Department of Radiation Oncology, Rochester, MN (United States); Inwards, Carrie Y. [Mayo Clinic, Department of Pathology, Rochester, MN (United States); Wenger, Doris E.; Amrami, Kimberly K. [Mayo Clinic, Department of Radiology, Rochester, MN (United States)

    2013-08-15

    Malignant degeneration arising in radiation-induced osteochondromas is extremely rare. We report a case of a 34-year-old man with a chondrosarcoma arising from an osteochondroma of the left posterior eighth rib that developed following total body irradiation received as part of the conditioning regimen prior to bone marrow transplantation at age 8. To our knowledge, this is only the fourth reported case of a chondrosarcoma arising within a radiation-induced osteochondroma and the first case occurring following childhood total body irradiation. (orig.)

  19. Use of radiation-induced degradation in controlling molecular weights of polysaccharides and conductivity of polyaniline blends

    International Nuclear Information System (INIS)

    Better understanding of chemistry of radiation-induced degradation is becoming of increasing importance on account of the utilization of polymeric materials in a variety of radiation environments as well as beneficial uses of degraded polymers. In this report degrading effects of radiation have been considered from the point of views of controlling the molecular weights of kappa- and iota-carrageenans and alginates on one hand and controlling the conductivity of polyaniline blends by doping via radiation induced HCl released from poly(vinyl chloride) on the other. (author)

  20. Trans-generational radiation-induced chromosomal instability in the female enhances the action of chemical mutagens

    Energy Technology Data Exchange (ETDEWEB)

    Camats, Nuria [Institut de Biotecnologia i Biomedicina (IBB), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Departament de Biologia Cel.lular, Fisiologia i Immunologia, Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Garcia, Francisca [Institut de Biotecnologia i Biomedicina (IBB), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Parrilla, Juan Jose [Servicio de Ginecologia y Obstetricia, Hospital Universitario Virgen de la Arrixaca, 30120 El Palmar, Murcia (Spain); Calaf, Joaquim [Servei de Ginecologia i Obstetricia, Hospital Universitari de la Santa Creu i Sant Pau, 08025 Barcelona (Spain); Martin, Miguel [Departament de Pediatria, d' Obstetricia i Ginecologia i de Medicina Preventiva, Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Caldes, Montserrat Garcia [Institut de Biotecnologia i Biomedicina (IBB), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Departament de Biologia Cel.lular, Fisiologia i Immunologia, Universitat Autonoma de Barcelona, 08193 Barcelona (Spain)], E-mail: Montserrat.Garcia.Caldes@uab.es

    2008-04-02

    Genomic instability can be produced by ionising radiation, so-called radiation-induced genomic instability, and chemical mutagens. Radiation-induced genomic instability occurs in both germinal and somatic cells and also in the offspring of irradiated individuals, and it is characterised by genetic changes including chromosomal rearrangements. The majority of studies of trans-generational, radiation-induced genomic instability have been described in the male germ line, whereas the authors who have chosen the female as a model are scarce. The aim of this work is to find out the radiation-induced effects in the foetal offspring of X-ray-treated female rats and, at the same time, the possible impact of this radiation-induced genomic instability on the action of a chemical mutagen. In order to achieve both goals, the quantity and quality of chromosomal damage were analysed. In order to detect trans-generational genomic instability, a total of 4806 metaphases from foetal tissues from the foetal offspring of X-irradiated female rats (5 Gy, acute dose) were analysed. The study's results showed that there is radiation-induced genomic instability: the number of aberrant metaphases and the breaks per total metaphases studied increased and were found to be statistically significant (p {<=} 0.05), with regard to the control group. In order to identify how this trans-generational, radiation-induced chromosomal instability could influence the chromosomal behaviour of the offspring of irradiated rat females in front of a chemical agent (aphidicolin), a total of 2481 metaphases were studied. The observed results showed that there is an enhancement of the action of the chemical agent: chromosomal breaks per aberrant metaphases show significant differences (p {<=} 0.05) in the X-ray- and aphidicolin-treated group as regards the aphidicolin-treated group. In conclusion, our findings indicate that there is trans-generational, radiation-induced chromosomal instability in the foetal

  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. Radiation-induced effects on some common storage edible seeds in India infested with surface microflora

    International Nuclear Information System (INIS)

    The present work describes radiation-induced effects on surface microorganisms on some stored seeds widely used in India. Co-60 gamma source at 25 degree sign C emitting gamma ray at 1173 and 1332 keV energy was used for irradiating the rice (Oryza sativa. Cv-2233 and Oryza sativa. Cv-Shankar) and pulse (Cicer arietinum. Cv-local) having >10% moisture content. Dose of gamma irradiation up to 6 kGy (0.12 kGy/h) was applied for exposing the seeds. Significant depletion of the fungal population on seeds was noted with irradiation at 1-2 kGy, while complete inhibition of the contaminating fungi was observed above 4 kGy. Though the germinating potential of the treated grains did not alter significantly, loss in membrane permeability of the exposed seeds was significant

  3. Graft polymerization using radiation-induced peroxides and application to textile dyeing

    Energy Technology Data Exchange (ETDEWEB)

    Enomoto, Ichiro, E-mail: enomoto.ichiro@iri-tokyo.j [Tokyo Metropolitan Industrial Technology Research Institute, KFC Bldg., 12F, 1-6-1, Yokoami, Sumida-ku, Tokyo 130-0015 (Japan); School of Engineering, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Katsumura, Yosuke [School of Engineering, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakata Shirane, Tokai-mura, Ibaraki 319-1195 (Japan); Kudo, Hisaaki [School of Engineering, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Soeda, Shin [Tokyo Metropolitan Industrial Technology Research Institute, KFC Bldg., 12F, 1-6-1, Yokoami, Sumida-ku, Tokyo 130-0015 (Japan)

    2011-02-15

    To improve the dyeing affinity of ultra high molecular weight polyethylene (UHMWPE) fiber, surface treatment by radiation-induced graft polymerization was performed. Methyl methacrylate (MMA), acrylic acid (AA) and styrene (St) were used as the monomers. The grafting yields as a function of storage time after irradiation were examined. Although the grafting yield of St after the sulfonation processing was quite low compared with those of MMA and AA, it was successfully dyed to a dark color with a cationic dye. Some acid dyes can dye the grafted fiber with AA. The acid dye is distributed to the amorphous domains of the AA grafted fiber. The dyeing concentration depended on the grafting yield, and the higher the grafting yield the darker the dye color.

  4. Theoretical epidemiology applied to health physics: estimation of the risk of radiation-induced breast cancer

    International Nuclear Information System (INIS)

    Indirect estimation of low-dose radiation hazards is possible using the multihit model of carcinogenesis. This model is based on cancer incidence data collected over many decades on tens of millions of people. Available data on human radiation effects can be introduced into the modeling process without the requirement that these data precisely define the model to be used. This reduction in the information demanded from the limited data on human radiation effects allows a more rational approach to estimation of low-dose radiation hazards and helps to focus attention on research directed towards understanding the process of carcinogenesis, rather than on repeating human or animal experiments that cannot provide sufficient data to resolve the low-dose estimation problem. Assessment of the risk of radiation-induced breast cancer provides an excellent example of the utility of multihit modeling procedures

  5. Three Cases of Radiation-Induced Hepatitis B Virus Reactivation after Hepatic Tomotherapy: Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Moon Kyoo; Hong, Seong Eon; Kim, Byung Ho; Choi, Jin Hyun [Kyung Hee University College of Medicine, Seoul (Korea, Republic of)

    2011-03-15

    Radiation-induced liver disease (RILD) has been characterized as a veno-occlusive disease with anicteric elevation of alkaline phosphatase (ALP). However, some RILD patients present with elevated transaminase levels rather than with anicteric elevation of ALP, and these findings are common in the Asia-Pacific region where hepatitis B virus (HBV) infection is associated with 70-90% of hepatocelluar carcinoma (HCC) cases. In addition, the development of RILD is more common in patients with hepatitis B virus-related HCC. These findings indicate that susceptibility to RILD might be different in HBV carriers and non-carriers, and moreover, RILD in patients with HBV-related HCC might be associated with another unique pathogenesis such as HBV reactivation. However, HBV reactivation after hepatic irradiation has been reported in only a few studies. This study reports three cases of HBV reactivation after hepatic tomotherapy for management of HCC.

  6. Investigation on the radiation induced conductivity of space-applied polyimide under cyclic electron irradiation

    Science.gov (United States)

    Yue, Long; Wu, Yiyong; Sun, Chengyue; Xiao, Jingdong; Shi, Yaping; Ma, Guoliang; He, Shiyu

    2012-11-01

    Radiation induced conductivity (RIC) is an important property of dielectric materials to evaluate the charge/discharge effect in orbit-service spacecraft. RIC of space-applied polyimide film was in situ measured and studied under continuous and cyclic electron irradiation in this paper. The results indicate that, for cyclic electron irradiation, there is a similar increasing-mode of RIC to those for continuous irradiation with the electron irradiation time. However, under the cyclic electron irradiation, the RIC of polyimide shows an obvious irradiation-history characteristic, namely preliminary irradiation dose effect (PIDE). In this case, the steady RIC value presents an "overshoot" behavior in the first few irradiation cycles and then decrease to a stable one as that under continuous irradiation. Prolonging the initial irradiation duration may avoid occurrence of overshoot phenomenon. The behaviors of irradiation-induced free radicals in polyimide could be applied to explain the RIC evolution processes.

  7. Determination of radiation-induced damage in lymphocytes using the micronucleus and microgel electrophoresis 'Comet' assays

    International Nuclear Information System (INIS)

    DNA damage assays may be useful as rapid predictors of normal tissue radiosensitivity in clinical samples. We measured in vitro radiation-induced (2 Gy) damage to lymphocytes from cancer patients and normal healthy donors using both the micronucleus and microgel electrophoresis (Comet) assays simultaneously. For damage assessment, there was a good correlation (P < 0.001) between the mean comet lengths and the fraction of cells with comets. There was no correlation with initial damage, determined as the proportion of cells within a sample that formed comets, in comparison with the mean frequency of micronuclei per binucleate cell. However, there appeared to be an association between the determination of repair proficiency in the Comet assay and the mean frequency of micronuclei per binucleate cell in lymphocytes from cancer patients. (author)

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

    International Nuclear Information System (INIS)

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

  9. Prompt radiation-induced conductivity in polyurethane foam and glass microballoons

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, E. Frederick; Zarick, Thomas Andrew; Sheridan, Timothy J.; Preston, Eric F.

    2014-06-01

    We performed measurements and analyses of the prompt radiation-induced conductivity (RIC) in thin samples of polyurethane foam and glass microballoon foam at the Little Mountain Medusa LINAC facility in Ogden, UT. The RIC coefficient was non-linear with dose rate for polyurethane foam; however, typical values at 1E11 rad(si)/s dose rate was measured as 0.8E-11 mho/m/rad/s for 5 lb./cu ft. foam and 0.3E-11 mho/m/rad/s for 10 lb./cu ft. density polyurethane foam. For encapsulated glass microballoons (GMB) the RIC coefficient was approximately 1E-15 mho/m/rad/s and was not a strong function of dose rate.

  10. Excision repair of UV radiation-induced DNA damage in Caenorhabditis elegans

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, P.S.; Hevelone, J.; Dwarakanath, V.; Mitchell, D.L. (Texas Christian Univ., Fort Worth (USA))

    1989-06-01

    Radioimmunoassays were used to monitor the removal of antibody-binding sites associated with the two major UV radiation-induced DNA photoproducts (cyclobutane dimers and (6-4) photoproducts). Unlike with cultured human cells, where (6-4) photoproducts are removed more rapidly than cyclobutane dimers, the kinetics of repair were similar for both lesions. Repair capacity in wild type diminished throughout development. The radioimmunoassays were also employed to confirm the absence of photoreactivation in C. elegans. In addition, three radiation-sensitive mutants (rad-1, rad-2, rad-7) displayed normal repair capacities. An excision defect was much more pronounced in larvae than embryos in the fourth mutant tested (rad-3). This correlates with the hypersensitivity pattern of this mutant and suggests that DNA repair may be developmentally regulated in C. elegans. The mechanism of DNA repair in C. elegans as well as the relationship between the repair of specific photoproducts and UV radiation sensitivity during development are discussed.

  11. Radiation induced crosslinking effect on semi - interpenetrating polymer networks of poly(vinyl alcohol

    Directory of Open Access Journals (Sweden)

    2007-07-01

    Full Text Available Semi-IPNs with varying contents of poly(vinyl alcohol (PVA, poly acrylamide (PAM and crosslinker N,N’-methylene bis acrylamide (MBA were prepared by redox polymerization method. The structural and morphological properties were studied by Fourier transform infrared (FTIR spectroscopy, environmental scanning electron microscopy (ESEM and X-ray diffraction (XRD methods, respectively. It was found that the surface of the hydrogel is heterogeneous with separated domains. XRD result shows the semi-crystalline nature of the semi-IPNs. The prepared semi-IPNs of different compositions were subjected to gamma irradiation (2 to 250 kGy and the radiation induced effects on their strength of the semi-IPNs were studied by measuring the surface microhardness using a Vickers microhardness tester. Significant changes were observed in the Vickers microhardness, which were correlated with molecular architecture of the prepared semi-IPNs.

  12. Superabsorbent Prepared by Radiation Induced Graft Copolymerization of Acrylic Acid onto Cassava Starch. Chapter 18

    International Nuclear Information System (INIS)

    Superabsorbent was synthesized by radiation induced graft polymerization of acrylic acid onto cassava starch. Parameters such as the absorbed dose and the amount of monomer were investigated in order to determine the optimum conditions for the grafting polymerization. Water retention, germination percentage, and germination energy were also determined in order to evaluate the possibility of superabsorbent in agricultural applications, especially in arid regions. The graft copolymer was characterized by the Fourier transform infrared spectroscopy (FTIR). Results indicated that the sand mixed with 0.1% wt superabsorbent could absorb more water than the sand without superabsorbent. The germination energy of corn seeds mixed with 0.5% superabsorbent was obviously higher than those without superabsorbent. These experimental results showed that the superabsorbent has considerable effects on seed germination and the growth of young plants. (author)

  13. Radiation-induced vasculopathy implicated by depressed blood flow and metabolism in a pineal glioma

    Energy Technology Data Exchange (ETDEWEB)

    Mineura, K.; Sasajima, T.; Kowada, M. (Akita University Hospital (Japan). Neurosurgical Service); Saitoh, H. (Oodate Municipal Hospital (Japan). Dept. of Neurosurgery); Shishido, F. (Research Inst. of Brain and Blood Vessels, Akita (Japan))

    1993-08-01

    A case of radiation-induced vasculopathy of a pineal glioma was presented with haemodynamic and metabolic changes before and after radiotherapy. After radiation of 60 Gy with conventional fractionation (1.8-2.0 Gy daily, 5 days per week), regional blood flow, oxygen extraction fraction, metabolic rate of oxygen, kinetic metabolic rate of glucose and the rate constants (K2, K3) were markedly depressed (20% or greater) compared with the pre-irradiated study. 7 months after radiotherapy, the patient developed transient episodes of both right and left upper limb convulsion, terminating in generalized convulsion. When she developed status epilepticus, computed tomography showed extensive low density areas in the territory supplied by the right middle cerebral and the right posterior cerebral arteries. (author).

  14. Radiation-Induced Centers in Lead Silicate Glasses Irradiated by Stationary and Pulsed Electron Beams

    Science.gov (United States)

    Zhidkov, I. S.; Zatsepin, A. F.; Konev, S. F.; Cholakh, S. O.

    2015-08-01

    Radiation-induced centers formed in heavy flint glasses irradiated by electron beams are investigated by the methods of optical and EPR spectroscopy. It is revealed that stable and short-living optical absorption centers of close natures are formed under irradiation by fast electrons. A correlation is established between the stable optical absorption bands and the EPR signals interpreted as signals of the (Pb2+)/h+ hole centers. The shortliving color centers are formed due to short-term distortion of the O-Pb bonds, and the stable centers are formed due to the spatial separation, thermalization, and subsequent stabilization of excited electrons and holes in tails of the localized states. Irradiation by electron beams leads to a change in the spectral characteristics of the fundamental absorption edge and, in particular, of the Urbach energy that determines the degree of structural disorder.

  15. Genetic basis of strain variation in levels of radiation-induced apoptosis of thymocytes.

    Science.gov (United States)

    Weil, M M; Amos, C I; Mason, K A; Stephens, L C

    1996-12-01

    Levels of radiation-induced apoptosis of thymocytes were compared in C57BL/6J and C3Hf/Kam mice. For up to 8 h after irradiation, levels of apoptosis were higher in the C57BL/6J strain for all doses assayed. The heritability of the strain difference in the extent of apoptosis resulting from irradiation was investigated using a breeding study. Analysis of the F1 and F2 intercross progeny of these two strains provided strong evidence for a maternal effect but little evidence of sex linkage. The results indicate that in this strain combination the level of apoptosis of thymocytes after irradiation is a heritable trait that is likely to be controlled by few genes. These genes should be detectable in a mapping study.

  16. Nuclear dynamics of radiation-induced foci in euchromatin and heterochromatin

    Energy Technology Data Exchange (ETDEWEB)

    Chiolo, Irene; Georgescu, Walter; Tang, Jonathan; Costes, Sylvain V.

    2013-09-03

    Repair of double strand breaks (DSBs) is essential for cell survival and genome integrity. While much is known about the molecular mechanisms involved in DSB repair and checkpoint activation, the roles of nuclear dynamics of radiation-induced foci (RIF) in DNA repair are just beginning to emerge. Here, we summarize results from recent studies that point to distinct features of these dynamics in two different chromatin environments: heterochromatin and euchromatin. We also discuss how nuclear architecture and chromatin components might control these dynamics, and the need of novel quantification methods for a better description and interpretation of these phenomena. These studies are expected to provide new biomarkers for radiation risk and new strategies for cancer detection and treatment.

  17. Radiation-induced femoral neck fracture in patients cured of cervical carcinoma

    International Nuclear Information System (INIS)

    In the years 1948-1967 8275 patients with cervical carcinoma in various grades of progression were treated at the Institute of Oncology in Warsaw by radiotherapy from external fields. Five-year survival without signs of recurrence was obtained in 4204 cases, 3863 of them were irradiated from external fields with X-rays under conventional conditions, while 341 received Co60 radiotherapy. In 43 patients treated with X-rays and radium and regarded as cured radiological evidence of femoral neck fracture was obtained. These patients account for 1.1% of all cured patients. In the group treated with Co60 radiation in only 1 case femoral neck fracture was observed (0.3%). In the group of cured patients with femoral neck fracture the method of irradiation from external fields, the age, clinical course, radiological appearance of radiation-induced changes and the method of fracture management were analysed. (author)

  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. Radiation-induced grafting of dimethylaminoethylmethacrylate onto PE/PP nonwoven fabric

    Energy Technology Data Exchange (ETDEWEB)

    Kavakli, Pinar Akkas [Hacettepe University, Department of Chemistry, Beytepe, 06532 Ankara (Turkey)], E-mail: pinar@hacettepe.edu.tr; Kavakli, Cengiz [General Directorate of Ankara Customs and Customs Enforcement, Ankara Central Laboratory, Ankara (Turkey); Seko, Noriaki; Tamada, Masao [Japan Atomic Energy Agency, Quantum Beam Science Directorate, 1233 Watanuki, Takasaki, Gunma (Japan); Gueven, Olgun [Hacettepe University, Department of Chemistry, Beytepe, 06532 Ankara (Turkey)

    2007-12-15

    A new adsorbent was prepared by radiation-induced graft polymerization of dimethylaminoethylmethacrylate (DMAEMA) onto polyethylene/polypropylene (PE/PP) nonwoven fabric. The trunk polymer was irradiated by electron beam at a voltage of 2 MeV and a current of 3 mA in nitrogen atmosphere at dry-ice temperature to different doses. The degree of grafting was determined as a function of irradiation dose, monomer concentration, temperature and reaction time. Grafting conditions were optimized and about 150% grafted samples were used for further experiments. DMAEMA grafted polymer was later protonated in acid solution to prepare specialty adsorbent for the removal of phosphate. Adsorption experiments were performed in column mode for removal of phosphate. It was shown that 2000 bed volumes of phosphate-free water can be produced from 100 ppb phosphate (as P) solution at high space velocity.

  20. Maintenance of radiation-induced intestinal fibrosis: Cellular and molecular features

    Institute of Scientific and Technical Information of China (English)

    Valérie Haydont; Marie-Catherine Vozenin-Brotons

    2007-01-01

    Recent advances in cell and molecular radiobiology clearly showed that tissue response to radiation injury cannot be restricted to a simple cell-killing process, but depends upon continuous and integrated pathogenic processes, involving cell differentiation and crosstalk between the various cellular components of the tissue within the extracellular matrix. Thus, the prior concept of primary cell target in which a single-cell type (whatever it's epithelial or endothelial cells) dictates the whole tissue response to radiation injury has to be replaced by the occurrence of coordinated multicellular response that may either lead to tissue recovery or to sequel development. In this context, the present review will focus on the maintenance of the radiation-induced wound healing and fibrogenic signals triggered by and through the microenvironment toward the mesencnymal cell compartment, and will highlight how sequential and sustained modifications in cell phenotypes will in cascade modify cell-to-cell interactions and tissue composition.

  1. The Use of Membranes Prepared by Radiation - Induced Grafting in Waste Water Treatment

    International Nuclear Information System (INIS)

    Membranes were prepared by the radiation-induced grafting of N-vinylpyrrolidone onto low density polyethylene and the possibility for their practical use in the removal of two dyes: Acid red 116(Erionyl red 2B) and blue reactive (Brilliant bright blue) was studied. The effect of the degree of grafting on the adsorption of these pollutants was investigated and showed maximum adsorption occurred at 394 % grafting. Radiation degradation of the dyes with a dose of ∼ 5 KGy was followed by adsorption of the residual concentration of the dyes by the membranes, which resulted in the complete removal of these pollutants as well as the radiolysis products present in the irradiated solutions. Also, characterization of the membranes before and after adsorption was carried out using thermogravimetric analysis and scanning electron microscopy

  2. Two-stage cell shrinkage and the OER for radiation-induced apoptosis of rat thymocytes

    International Nuclear Information System (INIS)

    Suspensions of rat thymocytes were given 0.09-100 Gy using 60Co γ-rays. The radiation-induced changes in the thermocytes were examined from minutes to hours post-irradiation using electron microscopy, agarose gel electrophoresis, staining and Coulter Counter sizing. Sizing by Coulter Counter showed, for the first time, that thermocytes which undergo apoptosis shrink in two distinct stages, first by a sudden decrease from an original volume of 99 μm3 to a volume of 76 μm3, followed by a gradual decrease to 57 μm3 over the space of a few hours. The oxygen enhancement ratio for apoptosis was measured to be about 3.5, similar to the value for reproductive death for many mammalian cells. (author)

  3. The mechanism of radiation-induced segregation in ferritic–martensitic alloys

    International Nuclear Information System (INIS)

    The mechanism of radiation-induced segregation in Fe–Cr alloys was modeled using the inverse Kirkendall mechanism and compared to experimental measurements over a range of temperatures, bulk Cr compositions, and irradiation dose. The model showed that over a large temperature range chromium was enriched at sinks by interstitial migration, and at very high temperatures it was depleted by diffusing opposite to the vacancy flux. Experimental results and model predictions were in good qualitative and quantitative agreement with regard to the temperature dependence of segregation and the crossover from Cr enrichment to Cr depletion. The inverse Kirkendall mechanism was also in agreement with experimental findings that observed a decreasing amount of Cr enrichment with increasing bulk Cr composition. The effects of solute drag were modeled within the inverse Kirkendall framework, but were unable to account for either the crossover from Cr enrichment to Cr depletion or the magnitudes of segregation measured in experiments

  4. Nuclear dynamics of radiation-induced foci in euchromatin and heterochromatin

    Energy Technology Data Exchange (ETDEWEB)

    Chiolo, Irene; Tang, Jonathan; Georgescu, Walter; Costes, Sylvain V.

    2013-10-01

    Repair of double strand breaks (DSBs) is essential for cell survival and genome integrity. While much is known about the molecular mechanisms involved in DSB repair and checkpoint activation, the roles of nuclear dynamics of radiation-induced foci (RIF) in DNA repair are just beginning to emerge. Here, we summarize results from recent studies that point to distinct features of these dynamics in two different chromatin environments: heterochromatin and euchromatin. We also discuss how nuclear architecture and chromatin components might control these dynamics, and the need of novel quantification methods for a better description and interpretation of these phenomena. These studies are expected to provide new biomarkers for radiation risk and new strategies for cancer detection and treatment.

  5. Radiation induced damage and recovery in poly(3-hexyl thiophene) based polymer solar cells.

    Science.gov (United States)

    Li, Gang; Yang, Yang; Devine, R A B; Mayberry, Clay

    2008-10-22

    Polymer solar cells have been characterized during and after x-ray irradiation. The open circuit voltage, dark current and power conversion efficiency show degradation consistent with the generation of defect states in the polymer semiconductor. The polymer solar cell device remained functional with exposure to a considerable dose (500 krad (SiO(2))) and showed clear signs of recovery upon removal of the irradiation source (degraded from 4.1% to 2.2% and recovered to 2.9%). Mobility-relaxation time variation, derived from J-V measurement, clearly demonstrates that radiation induced defect generation mechanisms in the organic semiconductor are active and need to be further studied. Optical transmission results ruled out the possibility of reduced light absorption and/or polymer crystallinity. The results suggest that organic solar cells are sufficiently radiation tolerant to be useful for space applications. PMID:21832674

  6. Cytoprotective Efficacy of Amifostine Against Radiation- Induced Rectal Toxicity: Objective and Subjective Grading Scales for Radiomucositis

    Directory of Open Access Journals (Sweden)

    John R. Kouvaris

    2008-04-01

    Full Text Available Curative radiation therapy of pelvic malignancies, frequently results in doselimitingtoxicities such as serous, mucoid, or more rarely, bloody diarrhea. Several studieshave evaluated the cytoprotective effects of amifostine in preventing rectal mucositisassociated with radiation treatment. We searched Medline for published comparativestudies that evaluated the use of amifostine to reduce radiation-induced toxicity associatedwith pelvic irradiation. In ten studies there was an evidence-based cytoprotection (P less than 0.05by amifostine. Although results are variable, current evidence suggests that amifostine mayhave a radioprotective effect in the rectal mucosa, particularly when administeredintrarectally. Significant improvements were seen in both symptomatic and objective(rectosigmoidoscopy end points. There is a need to conduct well-designed clinical trialswith sufficient numbers of participants to confirm these findings together with a costbenefitstudy. Objective measurements using rectosigmoidoscopy are superior tosubjective measures such as WHO or RTOG/EORTC toxicity grading scales.

  7. Radiation induced F1 sterility in Lepidoptera for area-wide control

    International Nuclear Information System (INIS)

    Very high doses of ionizing radiation are required to induce sterility in Lepidoptera, but fully sterilizing doses are detrimental to the reproductive competitiveness of the insects and so irradiated males are much less able to compete for mates. It appears, however, that inherited sterility can be induced in all Lepidoptera species by means of radiation doses that induce only low levels of sterility in irradiated individuals. In this way the detrimental effects of irradiation on reproductive performance can be largely avoided, and the irradiated males are able to compete for females with their wild counterparts. This is the basis of radiation induced F1 sterility for genetic pest control. These proceedings include thirteen papers on different aspects of F1 sterility, with emphasis on laboratory experiments to determine the dose of gamma radiation required for inherited sterility. The individual papers have been indexed separately. Refs, figs and tabs

  8. Grape Seed Oil Extract Protects Against Radiation-Induced Oxidative Damage in Rats Eyes

    International Nuclear Information System (INIS)

    The present study was carried out to investigate the beneficial effects of grape seed oil on radiation-induced oxidative stress in the irradiated rat eyes. The rats were divided into three groups; control group that received distilled water, irradiated group (R) that exposed to gamma radiation as a single dose of 6.4 Gy and irradiated + grape seed oil group (R+GSO) that administered grape seed oil for seven consecutive days then exposed to the same single gamma radiation dose followed by grape seed oil for seven additional days. Histopathological results revealed protective effect of grape seed oil on the eye tissues of rat. The results lead to the conclusion that administration of GSO prior to radiation exposure may be a promising attempt in attenuating the extent of oxidative damage accompanying radiotherapy

  9. Characterization of Network Structure of Polyacrylamide Based Hydrogels Prepared By Radiation Induced Polymerization

    International Nuclear Information System (INIS)

    In this study network structure of polyacrylamide based hydrogels prepared by radiation induced polymerization has been investigated. Polyacrylamide based hydrogels in the rod form were prepared by copolymerization of acrylamide(AAm) with hydroxyl ethyl methacrylate(HEMA) and methyl acrylamide(MAAm) in the presence of cross-linking agent and water by gamma rays at ambient temperature. Molecular weight between cross-links and effective cross-link density of hydrogels were calculated from swelling as well as shear modulus data obtained from compression tests. The results have shown that simple compression analyses can be used for the determination of effective cross-link density of hydrogels without any need to some polymer-solvent based parameters as in the case of swelling based determinations. Diffusion of water into hydrogels was examined by analyzing water absorption kinetics and the effect of network, structure on the diffusion type and coefficient was discussed

  10. Internal photoradiation effect. Radiation-induced luminescence and its influence on radiation processes

    International Nuclear Information System (INIS)

    Effect of radiation-induced luminescence on stabilization and reactions of intermediate charged particles in polymers in course of radiolysis is experimentally and theoretically investigated. The subjects of inquiry are polystyrene and polyvinyl alcohol films. Irradiation was carried out by 60Co γ-quanta in liquid nitrogen up to 5-10 kGy, the dose rate being approximately 5 Gy/s. It is stated that polymer luminescence results in decrease of concentration of stabilized charged particles, determines inequality of their distribution with respect to polymer volume and causes photochemical reactions. Contribution of photoradiation processes to radiation changes of material properties is defined by molecule properties, irradiation conditions, form and size of irradiated sample

  11. A case of buccal mucosal and maxillary tumor seemed to be radiation induced cancer

    International Nuclear Information System (INIS)

    A case of radiation-induced cancer was reported. A 46-year-old man developed buccal mucosal and maxillary cancer (squamous cell carcinoma) 19 years after external radiation therapy for buccal papilloma. Previous irradiation was 60Co, 186.5 Gy. Latent period was 19 years, but 7 years after the irradiation osteomyelitis arose in the mandible. X-ray films of the mandible revealed an osteolytic and osteosclerotic lesion. Conservative treatment of the osteomyelitis was not so effective. Partital resection of the mandible and resection of buccal scar tissue combined with reconstructive surgery of the cheek using a pectoralis major myocutaneous flap were performed in September, 1984. The histological examination of the resected specimen showed squamous cell carcinoma and the ultrastructural study on this case was further performed. In spite of wide excision and intra-arterial chemotherapy combined with irradiation, the patient died of the carcinoma in October, 1986. (author)

  12. A Human Espophageal Epithelial Cell Model for Study of Radiation Induced Cancer and DNA Damage Repair

    Science.gov (United States)

    Huff, Janice L.; Patel, Zarana S.; Hada, Megumi; Cucinotta, Francis A.

    2008-01-01

    For cancer risk assessment in astronauts and for countermeasure development, it is essential to understand the molecular mechanisms of radiation carcinogenesis and how these mechanisms are influenced by exposure to the types of radiation found in space. We are developing an in vitro model system for the study of radiation-induced initiation and progression of esophageal carcinoma, a type of cancer found to have a significant enhancement in incidence in the survivors of the atomic bomb detonations in Japan. Here we present the results of our preliminary characterization of both normal and hTERT immortalized esophageal epithelial cells grown in 2-dimensional culture. We analyzed DNA repair capacity by measuring the kinetics of formation and loss of - H2AX foci following radiation exposure. Additionally, we analyzed induction of chromosomal aberrations using 3-color fluorescence in situ hybridization (FISH). Data were generated using both low LET (gamma rays) and high LET ions (1000 MeV/nucleon iron).

  13. Pilot study of ice-ball cryotherapy for radiation-induced oral mucositis

    International Nuclear Information System (INIS)

    Oral mucositis caused by radiotherapy is intractable and may worsen the patient's nutritional condition and interrupt treatment. To reduce the incidence and severity of oral mucositis induced by cancer therapy and promote early improvement of its symptoms, we devised cryotherapy by ice balls using Elase (fibrinolysin and deoxyribonuclease, combined). The therapeutic effect of ice-ball cryotherapy was evaluated in 10 patients with carcinoma of the oral cavity and pharynx who were undergoing radiotherapy. Cryotherapy was continued from the development of oral mucositis until its disappearance. The severity of various symptoms of mucositis were reduced by cryotherapy. Healing required 3 to 16 days (median, 7 days) after the end of radiotherapy. Radiotherapy was not interrupted in any cases. This preliminary report suggests that ice-ball cryotherapy is an effective treatment for radiation-induced oral mucositis. (author)

  14. Pilot study of ice-ball cryotherapy for radiation-induced oral mucositis

    Energy Technology Data Exchange (ETDEWEB)

    Ohyama, Waichiro; Ebihara, Satoshi [National Cancer Center Hospital, Tokyo (Japan)

    1996-02-01

    Oral mucositis caused by radiotherapy is intractable and may worsen the patient`s nutritional condition and interrupt treatment. To reduce the incidence and severity of oral mucositis induced by cancer therapy and promote early improvement of its symptoms, we devised cryotherapy by ice balls using Elase (fibrinolysin and deoxyribonuclease, combined). The therapeutic effect of ice-ball cryotherapy was evaluated in 10 patients with carcinoma of the oral cavity and pharynx who were undergoing radiotherapy. Cryotherapy was continued from the development of oral mucositis until its disappearance. The severity of various symptoms of mucositis were reduced by cryotherapy. Healing required 3 to 16 days (median, 7 days) after the end of radiotherapy. Radiotherapy was not interrupted in any cases. This preliminary report suggests that ice-ball cryotherapy is an effective treatment for radiation-induced oral mucositis. (author).

  15. Model studies of radiation induced oxidation and reduction processes in DNA

    International Nuclear Information System (INIS)

    The papers presented in this thesis represent the major part of a systematic study of primary and secondary radiation induced damages in DNA. The magnetic resonance techniques EPR, ENDOR and FSE have been the experimental methods used. The study of radical formation in isolated DNA components under different environmental conditions demonstrates certain characteristics of the DNA components which are important in the study of DNA. It has been clearly demonstrated that the electrostatic environment, in particular the hydrogen bond pattern, is a vital factor for the secondary reaction scheme. Even radicals which are found in all related systems seem to be formed by different reaction pathways, depending upon the specific matrix. 92 refs., 2 figs., 6 tabs

  16. Advances of imaging on differential diagnosis between recurrence of glioma and radiation-induced brain injury

    International Nuclear Information System (INIS)

    Differentiating recurrence of glioma from radiation-induced brain injury is a central challenge in neuro-oncology. The 2 very different outcomes after brain tumor treatment often appear similar on traditional imaging studies. They may even manifest with similar clinical symptoms. Distinguishing treatment injury from tumor recurrence is crucial for diagnosis and treatment planning. In this article, we reviewed the latest developments and key findings from research studies exploring the efficacy of structural and functional imaging modalities in differentiating treatment injury from tumor recurrence with DWI, MRS, DCE-MR, DSC-MR, PET, and SPECT. And we discussed the advantages and disadvantages of each approach to provide useful information for making proper diagnosis and treatment planning. (authors)

  17. Adequacy of relative and absolute risk models for lifetime risk estimate of radiation-induced cancer

    International Nuclear Information System (INIS)

    This report examines the applicability of the relative (multiplicative) and absolute (additive) models in predicting lifetime risk of radiation-induced cancer. A review of the epidemiologic literature, and a discussion of the mathematical models of carcinogenesis and their relationship to these models of lifetime risk, are included. Based on the available data, the relative risk model for the estimation of lifetime risk is preferred for non-sex-specific epithelial tumours. However, because of lack of knowledge concerning other determinants of radiation risk and of background incidence rates, considerable uncertainty in modelling lifetime risk still exists. Therefore, it is essential that follow-up of exposed cohorts be continued so that population-based estimates of lifetime risk are available

  18. A Case of Radiation-Induced Multifocal Laryngeal Angiosarcoma Presenting as a Diagnostic Dilemma

    Directory of Open Access Journals (Sweden)

    Jayme R. Dowdall

    2012-01-01

    Full Text Available Head and neck sarcomas are relatively rare tumors, with angiosarcomas representing a small subset. Angiosarcoma is a malignant endothelial neoplasm characterized by atypical, multilayered, or solid endothelial proliferation with vasoformative architecture. The global incidence of irradiation-associated sarcoma is estimated as between 0.03% and 0.08%. Here we reported the case of an elderly woman previously treated with radiation more than 20 years ago for an unknown primary of head and neck. This interesting case presented as a diagnostic challenge, and multiple biopsies were required to eventually establish the diagnosis of laryngeal angiosarcoma. We additionally have confirmation from our prior radiation records that the patient did, in fact, receive a substantial dose of radiation to the site previously. To our knowledge, this case represents the first report of a documented radiation-induced multifocal laryngeal angiosarcoma.

  19. Measurements of the Radiation Induced Conductivity of Insulating Polymeric Materials for the James Webb Space Telescope

    Science.gov (United States)

    Corbridge, J.; Dennison, J. R.; Hodges, J.; Hoffmann, R. C.; Abbott, J.; Hunt, A.; Spaulding, R.

    2006-10-01

    We report on initial measurements of Radiation Induced Conductivity (RIC) for twelve thin film polymer materials that are used in the cabling of the James Webb Space Telescope. Results will be used to model possible detrimental arching due to space craft charging effects. RIC occurs when incident ionizing radiation deposits energy in a material and excites electrons into the conduction band of insulators. RIC is determined using a constant voltage test method as the difference in the equilibrium sample conductivity under no incident radiation and sample conductivity under an incident flux. An accelerator beam at the Idaho Accelerator Center provides the 2-5 MeV incident flux over a range of 10^2 to 10^+1 rad/sec. Measurements are made for a range of applied voltages and radiation dose rates.

  20. Experimental study of radiation induced electromotive force effects on mineral insulated cables

    Science.gov (United States)

    Van Nieuwenhove, R.; Vermeeren, L.

    2003-11-01

    Measurements of radiation induced electromotive force (RIEMF) effects on mineral insulated cables in a pure gamma field and in a combined neutron and gamma field are presented and compared to model calculations. The effect of materials in the immediate surroundings of the cable, as predicted by the model calculations, is clearly demonstrated. In a fission reactor environment, delayed current contributions due to the neutron activation and subsequent beta emission in base materials as well as in impurities such as Mn are clearly observed and are well reproduced by model calculations. The prediction of the gamma induced current component was severely complicated by its strong sensitivity to the detailed geometry and the spectrum and the directivity of the gamma field. Although the RIEMF effect on MI cables can therefore in general not be completely eliminated, some guidelines are provided to minimize them.

  1. Radiation-induced genome instability: the phenomenon, molecular mechanisms, pathogenetic significance

    International Nuclear Information System (INIS)

    Data on the radiation-induced genome instability as a special state of progeny of cells irradiated in vitro as well as after a whole body exposure to ionizing radiation, that make these cells considerably different from normal, unirradiated ones, were considered. This state present a number of cytogenetic, molecular-biological, cytological and biochemical manifestations untypical for normal cells. This state is controlled by the mechanisms of regulation of checkpoints of cell cycle, and apoptosis, that is under gene p53 control. The proof has been found that this state transfers from irradiated maternal cells to their surviving progeny by the epigenetic mechanisms and would exist until the cells restore the original state of response on the DNA damage

  2. Modulation of radiation induced alteration in the antioxidant status of mice by naringin

    International Nuclear Information System (INIS)

    The alteration of antioxidant status and lipid peroxidation by naringin, a citrus flavoglycoside, was investigated in Swiss albino mice treated with 2 mg/kg b. wt. naringin before exposure to 0.5, 1, 2, 3, and 4 Gy gamma radiation. Lipid peroxidation, glutathione, glutathione peroxidase, catalase and superoxide dismutase were determined in the liver and small intestine of mice treated or not with naringin at 0.5, 1, 2, 4 and 8 h post-irradiation. Whole-body irradiation of mice caused a dose dependent elevation in the lipid peroxidation while a dose dependent depletion was observed for glutathione, glutathione peroxidase, superoxide dismutase and catalase in both liver as well as small intestine. The study demonstrates that naringin protects mouse liver and intestine against the radiation-induced damage by elevating the antioxidant status and reducing the lipid peroxidation

  3. Propagating self-sustained annealing of radiation-induced interstitial complexes

    Science.gov (United States)

    Bokov, P. M.; Selyshchev, P. A.

    2016-02-01

    A propagating self-sustained annealing of radiation induced defects as a result of thermal-concentration instability is studied. The defects that are considered in the model are complexes. Each of them consists of one atom of impunity and of one interstitial atom. Crystal with defects has extra energy which is transformed into heat during defect annealing. Simulation of the auto-wave of annealing has been performed. The front and the speed of the auto-wave have been obtained. It is shown that annealing occurs in a narrow region of time and space. There are two kinds of such annealing behaviour. In the first case the speed of the auto-wave oscillates near its constant mean value and the front of temperature oscillates in a complex way. In the second case the speed of propagation is constant and fronts of temperature and concentration look like sigmoid functions.

  4. Sigmoid exclusion: a new technique in the management of radiation-induced fistula

    International Nuclear Information System (INIS)

    Colovesical and colovaginal fistulas following irradiation for pelvic malignancy represent a formidable surgical problem. Although complex surgical procedures to close the fistulas and restore continence have been described, often a defunctioning colostomy with an associated urinary conduit is the only feasible option. Three patients who have successfully undergone an original procedure (sigmoid exclusion) are presented. Sigmoid exclusion restores continence but avoids a permanent stoma. The involved sigmoid colon was isolated on its mesentery ensuring that the area incorporating the fistulas was not disrupted. The ends of the isolated sigmoid colon were closed and bowel continuity then restored by a colorectal or colo-anal anastomosis. Following closure of a temporary colostomy the patients were continent with no ill effects or sepsis from the excluded colon. This procedure has the dual advantage of restoring continence yet avoiding both an urinary conduit and a permanent colostomy, and represents a useful advance in the surgical management of radiation induced colonic fistulas. (author)

  5. Super absorbent Prepared by Radiation Induced Graft Copolymerization of Acrylic Acid onto Cassava Starch

    International Nuclear Information System (INIS)

    Full text: Super absorbent was synthesized by radiation-induced graft polymerization of acrylic acid onto cassava starch. Parameters such as the absorbed dose and the amount of monomer were investigated in order to determine the optimum conditions for the grafting polymerization. Water retention, germination percentage and germination energy were determined in order to evaluate the possibility of super absorbent in agricultural applications, especially in arid regions. The graft copolymer was characterized by FTIR. Results indicated that the sand mixed with 0.1%wt super absorbent can absorb more water than the sand without super absorbent. The germination energy of corn seeds mixed with 0.5% super absorbent was obviously higher than those without super absorbent. These experimental results showed that the super absorbent has considerable effect on seed germination and the growth of young plants. Keywords: Super absorbent, Radiation, Acrylic acid, Cassava starch

  6. Effect of radiation-induced substrate defects on microstrip gas chamber gain behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Pallares, A.; Brom, J.M.; Bergdolt, A.M.; Coffin, J.; Eberle, H.; Sigward, M.H. [Institute de Recherches Subatomiques, 67 - Strasbourg (France); Fontaine, J.C. [Universite de Haute Alsace, GRPHE, 61 rue Albert Camus, 68093 Mulhouse Cedex (France); Barthe, S.; Schunck, J.P. [Laboratoire PHASE (UPR 292 du CNRS), 23 rue du Loess, BP 28, 67037 Strasbourg Cedex 2 (France)

    1998-08-01

    The aim of this work was to quantify the influence of radiation-induced substrate defects on microstrip gas chamber (MSGC) gain behaviour. The first part of this paper focuses on radiation effects on a typical MSGC substrate: Desag D263 glass. Defect generation was studied for Desag D263 with pure silica (Suprasil 1) as a reference. We studied the evolution of defect concentration with respect to accumulated doses up to 480 kGy. Annealing studies of defects in Desag D263 were also performed. In the second part, the radiation sensitivity of Desag D263 glass has been linked to the behaviour of the detector under irradiation. Comparative gain measurements were taken before and after substrate irradiation at 10 and 80 kGy the minimal dose received during LHC operation and the dose for which defect density is maximum (respectively). (orig.) 26 refs.

  7. Radiation induced DNA double-strand breaks in radiology; Strahleninduzierte DNA-Doppelstrangbrueche in der Radiologie

    Energy Technology Data Exchange (ETDEWEB)

    Kuefner, M.A. [Dornbirn Hospital (Austria). Dept. of Radiology; Brand, M.; Engert, C.; Uder, M. [Erlangen University Hospital (Germany). Dept. of Radiology; Schwab, S.A. [Radiologis, Oberasbach (Germany)

    2015-10-15

    Shortly after the discovery of X-rays, their damaging effect on biological tissues was observed. The determination of radiation exposure in diagnostic and interventional radiology is usually based on physical measurements or mathematical algorithms with standardized dose simulations. γ-H2AX immunofluorescence microscopy is a reliable and sensitive method for the quantification of radiation induced DNA double-strand breaks (DSB) in blood lymphocytes. The detectable amount of these DNA damages correlates well with the dose received. However, the biological radiation damage depends not only on dose but also on other individual factors like radiation sensitivity and DNA repair capacity. Iodinated contrast agents can enhance the x-ray induced DNA damage level. After their induction DSB are quickly repaired. A protective effect of antioxidants has been postulated in experimental studies. This review explains the principle of the γ-H2AX technique and provides an overview on studies evaluating DSB in radiologic examinations.

  8. Radiatively induced flavour violation in the general two-Higgs doublet model with Yukawa alignment

    International Nuclear Information System (INIS)

    The most general two-Higgs doublet model contains new sources of flavour violation that are usually in conflict with the experimental constraints. One possibility to suppress the exotic contribution to the flavour changing neutral currents consists on imposing the alignment of the Yukawa couplings. This condition presumably holds at a high-energy scale and is spoiled by the radiative corrections. We compute in this Letter the size of the radiatively induced flavour violating Higgs couplings at the electroweak scale. These also yield the absolute lower bound on the size of the exotic contributions to the flavour changing neutral currents in any two-Higgs doublet model, barring cancellations and the existence of discrete symmetries. We show that these contributions are well below the experimental bounds in large regions of the parameter space.

  9. Radiation-Inducible Caspase-8 Gene Therapy for Malignant Brain Tumors

    International Nuclear Information System (INIS)

    Purpose: Patients with malignant gliomas have a poor prognosis. To explore a novel and more effective approach for the treatment of patients with malignant gliomas, we designed a strategy that combines caspase-8 (CSP8) gene therapy and radiation treatment (RT). In addition, the specificity of the combined therapy was investigated to decrease the unpleasant effects experienced by the surrounding normal tissue. Methods and Materials: We constructed the plasmid pEGR-green fluorescence protein that included the radiation-inducible early growth response gene-1 (Egr-1) promoter and evaluated its characteristics. The pEGR-CSP8 was constructed and included the Egr-1 promoter and CSP8 complementary DNA. Assays that evaluated the apoptosis inducibility and cytotoxicity caused by CSP8 gene therapy combined with RT were performed using U251 and U87 glioma cells. The pEGR-CSP8 was transfected into the subcutaneous U251 glioma cells of nude mice by means of in vivo electroporation. The in vivo effects of CSP8 gene therapy combined with RT were evaluated. Results: The Egr-1 promoter yielded a better response with fractionated RT than with single-dose RT. In the assay of apoptosis inducibility and cytotoxicity, pEGR-CSP8 showed response for RT. The pEGR-CSP8 combined with RT is capable of inducing cell death effectively. In mice treated with pEGR-CSP8 and RT, apoptotic cells were detected in pathologic sections, and a significant difference was observed in tumor volumes. Conclusions: Our results indicate that radiation-inducible gene therapy may have great potential because this can be spatially or temporally controlled by exogenous RT and is safe and specific

  10. Nigella sativa oil Ameliorates ionizing Radiation induced cellular injury in Male Albino Rats

    International Nuclear Information System (INIS)

    Nigella sativa (NS), commonly known as black seed, is a plant spices in which thymoquinone is the main active ingredient isolated from the black seeds. The seeds of Nigella sativa are used in herbal medicine all over the world for the treatment and prevention of a number of diseases. The aim of this study was focused on investigating the possible protective effect of NS against gamma radiation induced nephrotoxicity and inflammatory changes in male albino rats. Twenty four albino rats were divided into four equal groups as follows: control group, irradiated group (animals subjected to whole body gamma irradiation at a dose of 6 Gy), treated group (rats treated with 0.2 ml/kg, i.p., NS oil for 4 weeks), and treated irradiated group (animals treated with 0.2 mL/kg, i.p., NS oil for 4 weeks then exposed to whole body gamma irradiation at a dose of 6 Gy). The obtained results revealed that the administration of Nigella sativa oil to irradiated rats significantly ameliorated the changes induced in kidney antioxidant system; catalase and glutathione peroxidase activities as well as reduced glutathione concentration. Also, NS oil restored the kidney function indices (urea and creatinine) near normal level when compared with their equivalent values in irradiated rats. In addition, the changes in serum tumor necrosis factor alpha (TNF-α), Interleukin-1β (IL-1β) and Interleukin-6 (IL-6) activities were markedly improved compared to the corresponding values of irradiated group. The histopathological results showed distinctive pattern of ischemic renal injury in irradiated group, while in treated- irradiated group the renal tissues showed relatively well-preserved architecture with or without focal degeneration. In conclusion, NS acts in the kidney as a potent scavenger of free radicals to prevent or ameliorates the toxic effects of gamma irradiation as shown in the biochemical and histopathological study and also NS oil might provide substantial protection against

  11. Protective Role of Clove Against Radiation-Induced Oxidative Stress in Rats

    International Nuclear Information System (INIS)

    Antioxidants in food play an important role in preventing the generation of reactive oxygen species (ROS). Clove is widely used in Egypt as a spice which is a potent scavenger of a variety of free radicals. Clove (Syzygium aromaticum, Eugenia aromaticum or Eugenia caryophyllata) is the aromatic dried flower buds of a tree in the family Myrtaceae. The aim of this study was to investigate the radioprotective effect of cloves against oxidative stress and tissue injury, in animals, induced by gamma irradiation. Rats were subjected to two doses of gamma radiation (2 and 4 Gy). Four weeks before irradiation animals received cloves in basal diets. In liver and serum of irradiated animals, thiobarbituric acid reactive substances (TBARS) showed a significant increase associated to a marked decrease in glutathione (GSH) and catalase (CAT). The level of total lipids, cholesterol, triglycerides (TG) and low density lipoprotein-cholesterol (LDL-C) as well as aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) showed significant increase in the serum of irradiated rats. On the other hand, the level of high density lipoprotein-cholesterol (HDL-C), total protein, albumin and total globulins showed significant decrease. Rats fed on a basal diet containing cloves during a period of 4 weeks before irradiation showed significant improvement in the oxidant/antioxidant status denoted by a significant reduction in TBARS level associated with significant increase in GSH and CAT. Moreover, the radiation-induced changes in lipids, proteins and enzyme activities were significantly ameliorated. It could be concluded that cloves possibly protect against radiation-induced oxidative stress and tissue damage

  12. Modulation of modeled microgravity on radiation-induced bystander effects in Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ting [Key Laboratory of Ion Beam Bio-engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China); Sun, Qiao [Space Molecular Biological Lab, China Academy of Space Technology, Beijing 100086 (China); Xu, Wei; Li, Fanghua [Key Laboratory of Ion Beam Bio-engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China); Li, Huasheng; Lu, Jinying [Space Molecular Biological Lab, China Academy of Space Technology, Beijing 100086 (China); Wu, Lijun; Wu, Yuejin [Key Laboratory of Ion Beam Bio-engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China); Liu, Min [Space Molecular Biological Lab, China Academy of Space Technology, Beijing 100086 (China); Bian, Po [Key Laboratory of Ion Beam Bio-engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China)

    2015-03-15

    Highlights: • The effects of microgravity on the radiation-induced bystander effects (RIBE) were definitely demonstrated. • The effects of microgravity on RIBE might be divergent for different biological events. • The microgravity mainly modified the generation or transport of bystander signals at early stage. - Abstract: Both space radiation and microgravity have been demonstrated to have inevitable impact on living organisms during space flights and should be considered as important factors for estimating the potential health risk for astronauts. Therefore, the question whether radiation effects could be modulated by microgravity is an important aspect in such risk evaluation. Space particles at low dose and fluence rate, directly affect only a fraction of cells in the whole organism, which implement radiation-induced bystander effects (RIBE) in cellular response to space radiation exposure. The fact that all of the RIBE experiments are carried out in a normal gravity condition bring forward the need for evidence regarding the effect of microgravity on RIBE. In the present study, a two-dimensional rotation clinostat was adopted to demonstrate RIBE in microgravity conditions, in which the RIBE was assayed using an experimental system of root-localized irradiation of Arabidopsis thaliana (A. thaliana) plants. The results showed that the modeled microgravity inhibited significantly the RIBE-mediated up-regulation of expression of the AtRAD54 and AtRAD51 genes, generation of reactive oxygen species (ROS) and transcriptional activation of multicopy P35S:GUS, but made no difference to the induction of homologous recombination by RIBE, showing divergent responses of RIBE to the microgravity conditions. The time course of interaction between the modeled microgravity and RIBE was further investigated, and the results showed that the microgravity mainly modulated the processes of the generation or translocation of the bystander signal(s) in roots.

  13. Protective Effects of 5-Androstendiol (5-AED) on Radiation-induced Intestinal Injury

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joong Sun; Lee, Seung Sook; Jang, Won Suk; Lee, Sun Joo; Park, Sun Hoo; Kim, MinSook; Cho, Soo Youn [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Moon, Chang Jong; Kim, Sung Ho [Chonnam National University College of Veterinary Medicine, Gwangju (Korea, Republic of)

    2010-11-15

    We examined the radioprotective effects of 5-androstendiol (5-AED), a natural hormone produced in the reticularis of the adrenal cortex, as a result of intestinal damage in gamma-irradiated C3H/HeN mice. Thirty mice (C3H/HeN) were divided into three groups; 1) non-irradiated control group, 2) irradiated group, and 3) 5-AED-treated group prior to irradiation. Next, 5-AED (50 mg/kg per body weight) was subcutaneously injected 24 hours before irradiation. The mice were whole-body irradiated with 10 Gy for the histological examination of jejunal crypt survival and the determination of the villus morphology including crypt depth, crypt size, number of villi, villus height, and length of basal lamina, as well as 5 Gy for the detection of apoptosis. The 5-AED pre-treated group significantly increased the survival of the jejunal crypt, compared to irradiation controls (p<0.05 vs. irradiation controls at 3.5 days after 10 Gy). The evaluation of morphological changes revealed that the administration of 5-AED reduced the radiation-induced intestinal damages such as villus shortening and increased length of the basal lamina of enterocytes (p<0.05 vs irradiation controls on 3.5 day after 10 Gy, respectively). The administration of 5-AED decreased the radiation-induced apoptosis in the intestinal crypt, with no significant difference between the vehicle and 5-AED at 12 hours after 5 Gy. The results of this study suggest that the administration of 5-AED has a protective effect on intestinal damage induced by {gamma}-irradiation. In turn, these results suggest that 5-AED could be a useful candidate for radioprotection against intestinal mucosal injury following irradiation.

  14. Dragon's blood and its extracts attenuate radiation-induced oxidative stress in mice.

    Science.gov (United States)

    Ran, Yuanyuan; Wang, Ran; Gao, Qian; Jia, Qiutian; Hasan, Murtaza; Awan, Muhammad Umer Farooq; Tang, Bo; Zhou, Rui; Dong, Yiming; Wang, Xiao; Li, Qiang; Ma, Hong; Deng, Yulin; Qing, Hong

    2014-07-01

    Dragon's blood (DB) possesses great medicinal values due to the presence of several phenolic compounds. This study was designed to investigate the effects of DB and its extracts (DBEs) on oxidative stress in mice exposed to whole body (60)Co-γ irradiation (4 Gy). DB and DBEs were intragastrically administered to mice for 5 d prior to radiation. The antioxidant activities, including malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels in liver and spleen were measured using kits. Furthermore, DB and DBE effects were determined by organ indices and histology of liver and spleen. Our results indicated that the DB and DBE-treated groups showed a significant decrease (P < 0.05) in levels of MDA in liver and spleen compared with the irradiation-only group. Moreover, the activity of SOD, CAT and the level of GSH in liver and spleen tissue were enhanced significantly (P < 0.05) in the DB and DBE groups. DB and DBE also had a significant effect on the recovery of thymus indices. The histological observations of groups having treatment with DB and DBE indicated significant reduction in the radiation-induced damage to the liver and spleen, together with improvement in the morphology of the liver and spleen. These results suggest that DB and DBE treatment prevents radiation-induced oxidative stress injury and restores antioxidant status and histopathological changes in the liver and spleen, but there is need for further study to explore the precise molecular mechanism and strategy for optimal practical application of DB and DBE.

  15. Bone marrow stromal cell transplantation mitigates radiation-induced gastrointestinal syndrome in mice.

    Directory of Open Access Journals (Sweden)

    Subhrajit Saha

    Full Text Available BACKGROUND: Nuclear accidents and terrorism presents a serious threat for mass casualty. While bone-marrow transplantation might mitigate hematopoietic syndrome, currently there are no approved medical countermeasures to alleviate radiation-induced gastrointestinal syndrome (RIGS, resulting from direct cytocidal effects on intestinal stem cells (ISC and crypt stromal cells. We examined whether bone marrow-derived adherent stromal cell transplantation (BMSCT could restitute irradiated intestinal stem cells niche and mitigate radiation-induced gastrointestinal syndrome. METHODOLOGY/PRINCIPAL FINDINGS: Autologous bone marrow was cultured in mesenchymal basal medium and adherent cells were harvested for transplantation to C57Bl6 mice, 24 and 72 hours after lethal whole body irradiation (10.4 Gy or abdominal irradiation (16-20 Gy in a single fraction. Mesenchymal, endothelial and myeloid population were characterized by flow cytometry. Intestinal crypt regeneration and absorptive function was assessed by histopathology and xylose absorption assay, respectively. In contrast to 100% mortality in irradiated controls, BMSCT mitigated RIGS and rescued mice from radiation lethality after 18 Gy of abdominal irradiation or 10.4 Gy whole body irradiation with 100% survival (p<0.0007 and p<0.0009 respectively beyond 25 days. Transplantation of enriched myeloid and non-myeloid fractions failed to improve survival. BMASCT induced ISC regeneration, restitution of the ISC niche and xylose absorption. Serum levels of intestinal radioprotective factors, such as, R-Spondin1, KGF, PDGF and FGF2, and anti-inflammatory cytokines were elevated, while inflammatory cytokines were down regulated. CONCLUSION/SIGNIFICANCE: Mitigation of lethal intestinal injury, following high doses of irradiation, can be achieved by intravenous transplantation of marrow-derived stromal cells, including mesenchymal, endothelial and macrophage cell population. BMASCT increases blood levels of

  16. The radiation-induced fibroatrophic process: therapeutic perspective via the antioxidant pathway.

    Science.gov (United States)

    Delanian, Sylvie; Lefaix, Jean-Louis

    2004-11-01

    The radiation-induced fibroatrophic process (RIF) constitutes a late, local and unavoidable sequela to high-dose radiotherapy, traditionally considered irreversible. Today, this process is partly reversible, thanks to recent progress in understanding the physiopathology of the lesions it causes and the results of recent clinical trials using antioxidant therapy. This review includes a synthetic description of the static and dynamic features of the RIF process, as reflected by its clinical, instrumental and histopathological characteristics, and by its cellular and molecular regulation. Schematically, three successive clinical and histopathological phases can be distinguished: a pre-fibrotic aspecific inflammatory phase, a constitutive fibrotic cellular phase, and a matrix densification and remodelling phase, possibly ending in terminal tissular necrosis. The respective roles of the chief actors in the RIF process are defined, as well as their development with time. A fibroblastic stromal hypothesis is suggested revolving around a 'gravitational effect' exerted by the couple ROS (reactive oxygen species)--fibroblasts, and partly mediated by TGF-beta1. A variety of strategies have been tested for the management of RIF. In the light of the mechanisms described, a curative procedure has been proposed via the antioxidant pathway. In particular, it was showed that superoxide dismutase and combined pentoxifylline-tocopherol treatment enables the process of established radiation-induced fibroatrophy to be greatly reduced or even reversed, both in clinical practice and animal experiments. The efficacy of combined pentoxifylline-tocopherol treatment in superficial RIF was confirmed in a randomised clinical trial, and then in successful phase II trials especially in uterine fibroatrophy and osteoradionecrosis. It is of critical importance to evaluate these new management approaches in larger clinical trials and to improve the recording of results for better outcome analysis

  17. Wheat Germ Oil Attenuates Gamma Radiation- Induced Skeletal Muscles Damage in Rats

    International Nuclear Information System (INIS)

    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 beneficial in neutralizing the free oxygen radicals. The present study was designed to investigate the efficacy of wheat germ oil, on radiation-induced oxidative damage in rats skeletal muscle. Wheat germ oil was supplemented orally via gavages to rats at a dose of 54 mg/ kg body weight/day for 14 successive days pre- and 7 post-exposure to 5 Gy (one shot dose) of whole body gamma irradiation. Animals were sacrificed 7, 14 and 21 days post radiation exposure. The results revealed that whole body gamma-irradiation of rats induces oxidative stress in skeletal muscles obvious by significant elevation in the level of thiobarbituric acid reactive substances (TBARS) associated with significant decreases in the content of reduced glutathione (GSE1), as well as decreases in superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities. Irradiated rats showed, also, significant decreases in creatine phosphokinase (CPK), glutamate dehydrogenase (GDH) and glucose-6-phosphate dehydrogenase (G-6-PD) activities. Furthermore, total iron, total copper and total calcium levels were significantly increased in skeletal muscles of irradiated rats group compared to control group. Wheat germ oil treated-irradiated rats showed significantly less sever damage and remarkable improvement in all the measured parameters, compared to irradiated rats. It could be concluded that wheat germ oil by attenuating radiation induced oxidative stress might play a role in maintaining skeletal muscle integrity

  18. Radiation-induced oesophagitis in lung cancer patients. Is susceptibility for neutropenia a risk factor?

    Energy Technology Data Exchange (ETDEWEB)

    Ruysscher, D. de [MAASTRO Clinic, Maastricht (Netherlands). Dept. of Radiation Oncology; Meerbeeck, J. van [Ghent Univ. Hospital (Belgium). Dept. of Respiratory Medicine; Vandecasteele, K. [Ghent Univ. Hospital (BE). Dept. of Radiation Oncology] (and others)

    2012-07-15

    Background: Radiation-induced oesophagitis is a major side effect of concurrent chemotherapy and radiotherapy. A strong association between neutropenia and oesophagitis was previously shown, but external validation and further elucidation of the possible mechanisms are lacking. Methods and patients: A total of 119 patients were included at two institutions. The concurrent group comprised 34 SCLC patients treated with concurrent carboplatin and etoposide, and concurrent chest irradiation, and 36 NSCLC patients with concurrent cisplatin and etoposide, and concurrent radiotherapy, while the sequential group comprised 49 NSCLC patients received sequential cisplatin and gemcitabine, and radiotherapy. Results: Severe neutropenia was very frequent during concurrent chemoradiation (grade: 4 41.4%) and during induction chemotherapy in sequentially treated patients (grade 4: 30.6%), but not during radiotherapy (only 4% grade 1). In the concurrent group, the odds ratios of grade 3 oesophagitis vs. neutropenia were the following: grade 2 vs. grade 0/1: 5.60 (95% CI 1.55-20.26), p = 0.009; grade 3 vs. grade 0/1: 10.40 (95% CI 3.19-33.95); p = 0.0001; grade 4 vs. grade 0/1: 12.60 (95% CI 4.36-36.43); p < 0.00001. There was no correlation between the occurrence of neutropenia during induction chemotherapy and acute oesophagitis during or after radiotherapy alone. In the univariate analysis, total radiation dose (p < 0.001), overall treatment time of radiotherapy (p < 0.001), mean oesophageal dose (p = 0.038) and neutropenia (p < 0.001) were significantly associated with the development of oesophagitis. In a multivariate analysis, only neutropenia remained significant (p = 0.023). Conclusion: We confirm that neutropenia is independently correlated with oesophagitis in concurrent chemoradiation, but that the susceptibility for chemotherapy-induced neutropenia is not associated with radiation-induced oesophagitis. Further studies focusing on the underlying mechanisms are thus

  19. HGF Gene Modification in Mesenchymal Stem Cells Reduces Radiation-Induced Intestinal Injury by Modulating Immunity.

    Directory of Open Access Journals (Sweden)

    Hua Wang

    Full Text Available Effective therapeutic strategies to address intestinal complications after radiation exposure are currently lacking. Mesenchymal stem cells (MSCs, which display the ability to repair the injured intestine, have been considered as delivery vehicles for repair genes. In this study, we evaluated the therapeutic effect of hepatocyte growth factor (HGF-gene-modified MSCs on radiation-induced intestinal injury (RIII.Female 6- to 8-week-old mice were radiated locally at the abdomen with a single 13-Gy dose of radiation and then treated with saline control, Ad-HGF or Ad-Null-modified MSCs therapy. The transient engraftment of human MSCs was detected via real-time PCR and immunostaining. The therapeutic effects of non- and HGF-modified MSCs were evaluated via FACS to determine the lymphocyte immunophenotypes; via ELISA to measure cytokine expression; via immunostaining to determine tight junction protein expression; via PCNA staining to examine intestinal epithelial cell proliferation; and via TUNEL staining to detect intestinal epithelial cell apoptosis.The histopathological recovery of the radiation-injured intestine was significantly enhanced following non- or HGF-modified MSCs treatment. Importantly, the radiation-induced immunophenotypic disorders of the mesenteric lymph nodes and Peyer's patches were attenuated in both MSCs-treated groups. Treatment with HGF-modified MSCs reduced the expression and secretion of inflammatory cytokines, including tumor necrosis factor alpha (TNF-α and interferon-gamma (IFN-γ, increased the expression of the anti-inflammatory cytokine IL-10 and the tight junction protein ZO-1, and promoted the proliferation and reduced the apoptosis of intestinal epithelial cells.Treatment of RIII with HGF-gene-modified MSCs reduces local inflammation and promotes the recovery of small intestinal histopathology in a mouse model. These findings might provide an effective therapeutic strategy for RIII.

  20. p21 is Responsible for Ionizing Radiation-induced Bypass of Mitosis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xu Rui; LIU Yong Ai; SUN Fang; LI He; LEI Su Wen; WANG Ju Fang

    2016-01-01

    Objective To explore the role of p21 in ionizing radiation-induced changes in protein levels during the G2/M transition and long-term G2 arrest. Methods Protein expression levels were assessed by western blot in the human uveal melanoma 92-1 cells after treatment with ionizing radiation. Depletion of p21 was carried out by employing the siRNA technique. Cell cycle distribution was determined by flow cytometry combined with histone H3 phosphorylation at Ser28, an M-phase marker. Senescence was assessed by senescence-associated-β-galactosidase (SA-β-gal) staining combined with Ki67 staining, a cell proliferation marker. Results Accompanying increased p21, the protein levels of G2/M transition genes declined significantly in 92-1 cells irradiated with 5 Gy of X-rays. Furthermore, these irradiated cells were blocked at the G2 phase followed by cellular senescence. Depletion of p21 rescued radiation-induced G2 arrest as demonstrated by the upregulation of G2/M transition kinases, as well as the high expression of histone H3 phosphorylated at Ser28. Knockdown of p21 resulted in entry into mitosis of irradiated 92-1 cells. However, cells with serious DNA damage failed to undergo cytokinesis, leading to the accumulation of multinucleated cells. Conclusion Our results indicated that p21 was responsible for the downregulation of G2/M transition regulatory proteins and the bypass of mitosis induced by irradiation. Downregulation of p21 by siRNA resulted in G2-arrested cells entering into mitosis with serious DNA damage. This is the first report on elucidating the role of p21 in the bypass of mitosis.