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Sample records for cells radiation quality

  1. Glioblastoma stem cells: radiobiological response to ionising radiations of different qualities.

    Science.gov (United States)

    Pecchia, I; Dini, V; Ricci-Vitiani, L; Biffoni, M; Balduzzi, M; Fratini, E; Belli, M; Campa, A; Esposito, G; Cirrone, G; Romano, F; Stancampiano, C; Pelacchi, F; Pallini, R; Tabocchini, M A

    2015-09-01

    Glioblastoma multiforme (GBM) is the most common and malignant primary brain tumour, with very poor prognosis. The high recurrence rate and failure of conventional treatments are expected to be related to the presence of radio-resistant cancer stem cells (CSCs) inside the tumour mass. CSCs can both self-renew and differentiate into the heterogeneous lineages of cancer cells. Recent evidence showed a higher effectiveness of C-ions and protons in inactivating CSCs, suggesting a potential advantage of Hadrontherapy compared with conventional radiotherapy for GBM treatment. To investigate the mechanisms involved in the molecular and cellular responses of CSCs to ionising radiations, two GBM stem cell (GSC) lines, named lines 1 and 83, which were derived from patients with different clinical outcomes and having different metabolic profiles (as shown by NMR spectroscopy), were irradiated with (137)Cs photons and with protons or C-ions of 62 MeV u(-1) in the dose range of 5-40 Gy. The biological effects investigated were: cell death, cell cycle progression, and DNA damage induction and repair. Preliminary results show a different response to ionising radiation between the two GSC lines for the different end points investigated. Further experiments are in progress to consolidate the data and to get more insights on the influence of radiation quality.

  2. Effects of the ionizing radiations, freezing and thawing duration on chicken liver cells quality

    Science.gov (United States)

    Duarte, R. C.; Araújo, M. M.; Salum, D. C.; Marchioni, E.; Villavicencio, A. L. C. H.

    2009-07-01

    All food storage processes modify the food. Irradiation reduces and could stop cell division, avoid infestation, reduce contamination and delay food decomposition. The cold chain is a succession of steps which maintains the food at low temperature. Defrosted food shall never be frozen again, the best way being to consume it quickly then avoiding multiplication and acceleration of microbial growth, which causes decay and nutrients damage. The Comet Assay indicates DNA damage and can then be used to control the overall quality of the food and in a certain extent to evaluate the damage caused by irradiation and storage on liver chicken cells. In this work, different thawing temperatures and radiation doses were checked to establish a "DNA damage index" by using the Comet Assay. Samples were irradiated in a 60Co irradiator with 1.5, 3.0 and 4.5 kGy radiation doses. Our results showed that no intact cells were detected in frozen samples: however, irradiated liver samples in natura showed some intact cells depending on the applied radiation doses.

  3. Effects of the ionizing radiations, freezing and thawing duration on chicken liver cells quality

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, R.C. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Av. Professor Lineu Prestes 2242 Zip code, 05508-000 Cidade Universitaria Sao Paulo, SP-Brazil (Brazil)], E-mail: renatocduarte@yahoo.com.br; Araujo, M.M.; Salum, D.C. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Av. Professor Lineu Prestes 2242 Zip code, 05508-000 Cidade Universitaria Sao Paulo, SP-Brazil (Brazil); Marchioni, E. [IPHC-UMR 7178-Faculte de Pharmacie, 74 route du Rhin, 67400 Illkirch (France); Villavicencio, A.L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Av. Professor Lineu Prestes 2242 Zip code, 05508-000 Cidade Universitaria Sao Paulo, SP-Brazil (Brazil)], E-mail: villavic@ipen.br

    2009-07-15

    All food storage processes modify the food. Irradiation reduces and could stop cell division, avoid infestation, reduce contamination and delay food decomposition. The cold chain is a succession of steps which maintains the food at low temperature. Defrosted food shall never be frozen again, the best way being to consume it quickly then avoiding multiplication and acceleration of microbial growth, which causes decay and nutrients damage. The Comet Assay indicates DNA damage and can then be used to control the overall quality of the food and in a certain extent to evaluate the damage caused by irradiation and storage on liver chicken cells. In this work, different thawing temperatures and radiation doses were checked to establish a 'DNA damage index' by using the Comet Assay. Samples were irradiated in a {sup 60}Co irradiator with 1.5, 3.0 and 4.5 kGy radiation doses. Our results showed that no intact cells were detected in frozen samples: however, irradiated liver samples in natura showed some intact cells depending on the applied radiation doses.

  4. Dependence of Early and Late Chromosomal Aberrations on Radiation Quality and Cell Types

    Science.gov (United States)

    Lu, Tao; Zhang, Ye; Krieger, Stephanie; Yeshitla, Samrawit; Goss, Rosalin; Bowler, Deborah; Kadhim, Munira; Wilson, Bobby; Rohde, Larry; Wu, Honglu

    2017-01-01

    Exposure to radiation induces different types of DNA damage, increases mutation and chromosome aberration rates, and increases cellular transformation in vitro and in vivo. The susceptibility of cells to radiation depends on genetic background and growth condition of cells, as well as types of radiation. Mammalian cells of different tissue types and with different genetic background are known to have different survival rate and different mutation rate after cytogenetic insults. Genomic instability, induced by various genetic, metabolic, and environmental factors including radiation, is the driving force of tumorigenesis. Accurate measurements of the relative biological effectiveness (RBE) is important for estimating radiation-related risks. To further understand genomic instability induced by charged particles and their RBE, we exposed human lymphocytes ex vivo, human fibroblast AG1522, human mammary epithelial cells (CH184B5F5/M10), and bone marrow cells isolated from CBA/CaH(CBA) and C57BL/6 (C57) mice to high energy protons and Fe ions. Normal human fibroblasts AG1522 have apparently normal DNA damage response and repair mechanisms, while mammary epithelial cells (M10) are deficient in the repair of DNA DSBs. Mouse strain CBA is radio-sensitive while C57 is radio-resistant. Metaphase chromosomes at different cell divisions after radiation exposure were collected and chromosome aberrations were analyzed as RBE for different cell lines exposed to different radiations at various time points up to one month post irradiation.

  5. The indirect effect of radiation reduces the repair fidelity of NHEJ as verified in repair deficient CHO cell lines exposed to different radiation qualities and potassium bromate

    Energy Technology Data Exchange (ETDEWEB)

    Bajinskis, Ainars, E-mail: ainars.bajinskis@gmt.su.se [Centre for Radiation Protection Research, Department of Genetics, Microbiology and Toxicology, Stockholm University, S-10691 Stockholm (Sweden); Olsson, Gunilla; Harms-Ringdahl, Mats [Centre for Radiation Protection Research, Department of Genetics, Microbiology and Toxicology, Stockholm University, S-10691 Stockholm (Sweden)

    2012-03-01

    The complexity of DNA lesions induced by ionizing radiation is mainly dependent on radiation quality, where the indirect action of radiation may contribute to different extent depending on the type of radiation under study. The effect of indirect action of radiation can be investigated by using agents that induce oxidative DNA damage or by applying free radical scavengers. The aim of this study was to investigate the role of the indirect effect of radiation for the repair fidelity of non-homologous end-joining (NHEJ), homologous recombination repair (HRR) and base excision repair (BER) when DNA damage of different complexity was induced by gamma radiation, alpha particles or from base damages (8-oxo-dG) induced by potassium bromate (KBrO{sub 3}). CHO cells lines deficient in XRCC3 (HRR) irs1SF, XRCC7 (NHEJ) V3-3 and XRCC1 (BER) EM9 were irradiated in the absence or presence of the free radical scavenger dimethyl sulfoxide (DMSO). The endpoints investigated included rate of cell proliferation by the DRAG assay, clonogenic cell survival and the level of primary DNA damage by the comet assay. The results revealed that the indirect effect of low-LET radiation significantly reduced the repair fidelity of both NHEJ and HRR pathways. For high-LET radiation the indirect effect of radiation also significantly reduced the repair fidelity for the repair deficient cell lines. The results suggest further that the repair fidelity of the error prone NHEJ repair pathway is more impaired by the indirect effect of high-LET radiation relative to the other repair pathways studied. The response to bromate observed for the two DSB repair deficient cell lines strongly support earlier studies that bromate induces complex DNA damages. The significantly reduced repair fidelity of irs1SF and V3-3 suggests that NHEJ as well as HRR are needed for the repair, and that complex DSBs are formed after bromate exposure.

  6. M-BAND Study of Radiation-Induced Chromosome Aberrations in Human Epithelial Cells: Radiation Quality and Dose Rate Effects

    Science.gov (United States)

    Hada, Megumi; Cucinotta, Francis; Wu, Honglu

    2009-01-01

    The advantage of the multicolor banding in situ hybridization (mBAND) technique is its ability to identify both inter- (translocation to unpainted chromosomes) and intra- (inversions and deletions within a single painted chromosome) chromosome aberrations simultaneously. To study the detailed rearrangement of low- and high-LET radiation induced chromosome aberrations in human epithelial cells (CH184B5F5/M10) in vitro, we performed a series of experiments with Cs-137 gamma rays of both low and high dose rates, neutrons of low dose rate and 600 MeV/u Fe ions of high dose rate, with chromosome 3 painted with multi-binding colors. We also compared the chromosome aberrations in both 2- and 3-dimensional cell cultures. Results of these experiments revealed the highest chromosome aberration frequencies after low dose rate neutron exposures. However, detailed analysis of the radiation induced inversions revealed that all three radiation types induced a low incidence of simple inversions. Most of the inversions in gamma-ray irradiated samples were accompanied by other types of intra-chromosomal aberrations but few inversions were accompanied by inter-chromosomal aberrations. In contrast, neutrons and Fe ions induced a significant fraction of inversions that involved complex rearrangements of both inter- and intrachromosomal exchanges. The location of the breaks involved in chromosome exchanges was analyzed along the painted chromosome. The breakpoint distribution was found to be randomly localized on chromosome 3 after neutron or Fe ion exposure, whereas non-random distribution with clustering breakpoints was observed after -ray exposure. Our comparison of chromosome aberration yields between 2- and 3-dimensional cell cultures indicated a significant difference for gamma exposures, but not for Fe ion exposures. These experimental results indicated that the track structure of the radiation and the cellular/chromosome structure can both affect radiation-induced chromosome

  7. Cell Radiation Experiment System

    Science.gov (United States)

    Morrison, Dennis R.

    2010-01-01

    The cell radiation experiment system (CRES) is a perfused-cell culture apparatus, within which cells from humans or other animals can (1) be maintained in homeostasis while (2) being exposed to ionizing radiation during controlled intervals and (3) being monitored to determine the effects of radiation and the repair of radiation damage. The CRES can be used, for example, to determine effects of drug, radiation, and combined drug and radiation treatments on both normal and tumor cells. The CRES can also be used to analyze the effects of radiosensitive or radioprotectant drugs on cells subjected to radiation. The knowledge gained by use of the CRES is expected to contribute to the development of better cancer treatments and of better protection for astronauts, medical-equipment operators, and nuclear-power-plant workers, and others exposed frequently to ionizing radiation.

  8. DSB repair model for mammalian cells in early S and G1 phases of the cell cycle: application to damage induced by ionizing radiation of different quality.

    Science.gov (United States)

    Taleei, Reza; Girard, Peter M; Nikjoo, Hooshang

    2015-02-01

    The purpose of this work is to test the hypothesis that kinetics of double strand breaks (DSB) repair is governed by complexity of DSB. To test the hypothesis we used our recent published mechanistic mathematical model of DSB repair for DSB induced by selected protons, deuterons, and helium ions of different energies representing radiations of different qualities. In light of recent advances in experimental and computational techniques, the most appropriate method to study cellular responses in radiation therapy, and exposures to low doses of ionizing radiations is using mechanistic approaches. To this end, we proposed a 'bottom-up' approach to study cellular response that starts with the DNA damage. Monte Carlo track structure method was employed to simulate initial damage induced in the genomic DNA by direct and indirect effects. Among the different types of DNA damage, DSB are known to be induced in simple and complex forms. The DSB repair model in G1 and early S phases of the cell cycle was employed to calculate the repair kinetics. The model considers the repair of simple and complex DSB, and the DSB produced in the heterochromatin. The inverse sampling method was used to calculate the repair kinetics for each individual DSB. The overall repair kinetics for 500 DSB induced by single tracks of the radiation under test were compared with experimental results. The results show that the model is capable of predicting the repair kinetics for the DSB induced by radiations of different qualities within an accepted range of uncertainty.

  9. Solar cell radiation handbook

    Science.gov (United States)

    Tada, H. Y.; Carter, J. R., Jr.; Anspaugh, B. E.; Downing, R. G.

    1982-01-01

    The handbook to predict the degradation of solar cell electrical performance in any given space radiation environment is presented. Solar cell theory, cell manufacturing and how they are modeled mathematically are described. The interaction of energetic charged particles radiation with solar cells is discussed and the concept of 1 MeV equivalent electron fluence is introduced. The space radiation environment is described and methods of calculating equivalent fluences for the space environment are developed. A computer program was written to perform the equivalent fluence calculations and a FORTRAN listing of the program is included. Data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence are presented.

  10. A Biodosimeter for Multiparametric Determination of Radiation Dose, Radiation Quality, and Radiation Risk

    Science.gov (United States)

    Richmond, Robert; Cruz, Angela; Jansen, Heather; Bors, Karen

    2003-01-01

    Predicting risk of human cancer following exposure of an individual or a population to ionizing radiation is challenging. To an approximation, this is because uncertainties of uniform absorption of dose and the uniform processing of dose-related damage at the cellular level within a complex set of biological variables degrade the confidence of predicting the delayed expression of cancer as a relatively rare event. Cellular biodosimeters that simultaneously report: 1) the quantity of absorbed dose after exposure to ionizing radiation, 2) the quality of radiation delivering that dose, and 3) the risk of developing cancer by the cells absorbing that dose would therefore be useful. An approach to such a multiparametric biodosimeter will be reported. This is the demonstration of a dose responsive field effect of enhanced expression of keratin 18 (K18) in cultures of human mammary epithelial cells irradiated with cesium-1 37 gamma-rays. Dose response of enhanced K18 expression was experimentally extended over a range of 30 to 90 cGy for cells evaluated at mid-log phase. K18 has been reported to be a marker for tumor staging and for apoptosis, and thereby serves as an example of a potential marker for cancer risk, where the reality of such predictive value would require additional experimental development. Since observed radiogenic increase in expression of K18 is a field effect, ie., chronically present in all cells of the irradiated population, it may be hypothesized that K18 expression in specific cells absorbing particulate irradiation, such as the high-LET-producing atomic nuclei of space radiation, will report on both the single-cell distributions of those particles amongst cells within the exposed population, and that the relatively high dose per cell delivered by densely ionizing tracks of those intersecting particles will lead to cell-specific high-expression levels of K18, thereby providing analytical end points that may be used to resolve both the quantity and

  11. Quality of Life (QOL) Analysis of a Randomized Radiation Dose Escalation Non-Small Cell Lung Cancer (NSCLC) Study: Radiation Therapy Oncology Group (RTOG) Trial 0617

    Science.gov (United States)

    Movsas, Benjamin; Hu, Chen; Sloan, Jeffrey; Bradley, Jeffrey; Komaki, Ritsuko; Masters, Gregory; Kavadi, Vivek; Narayan, Samir; Michalski, Jeff; Johnson, Douglas W.; Koprowski, Christopher; Curran, Walter J.; Garces, Yolanda I.; Gaur, Rakesh; Wynn, Raymond B.; Schallenkamp, John; Gelblum, Daphna Y.; MacRae, Robert M; Paulus, Rebecca; Choy, Hak

    2015-01-01

    Importance A recent randomized radiation dose escalation trial in unresectable stage III NSCLC showed a lower survival in the high-dose arm (74Gy vs. 60Gy) with concurrent chemotherapy. Quality of life (QOL), an important secondary endpoint, is presented here. Objective The primary QOL hypothesis predicted a clinically meaningful decline (CMD) in QOL via the Functional Assessment of Cancer Therapy-Lung Cancer Subscale (FACT-LCS) in the high-dose RT-arm at 3 months. Design RTOG 0617 was a randomized phase III study (conducted from Nov 2007 to Nov 2011) in stage III NSCLC using a 2×2 factorial design and stratified by histology, PET staging, performance status and radiation technique (3D-conformal RT [3DCRT] vs. intensity-modulated radiation [IMRT]). Setting 185 institutions in the USA and Canada. Participants Of 424 eligible stage III NSCLC patients randomized, 360 (85%) consented to QOL, of whom 313 (88%) completed baseline QOL assessments. Intervention for Clinical Trials 74Gy vs. 60Gy with concurrent and consolidation carboplatin/paclitaxel +/− cetuximab. Main Outcomes and Measures QOL was collected prospectively via FACT-Trial Outcome Index (FACT-TOI), equaling Physical-Well-Being (PWB) + Functional-Well-Being (FWB) + Lung Cancer Subscale (LCS). Data are presented at baseline & 3 and 12 months via minimal clinically meaningful changes of >=2 points for PWB, FWB or LCS or >=5 points for TOI. Results Patient demographics and baseline QOL scores were comparable between the 74Gy and 60Gy arms. Two-hundred-nineteen (72%) of living patients who completed QOL at baseline did so at 3 months and 137 (57%) of living patients did so at 12 months. Significantly more patients on 74Gy arm had clinically meaningful decline in FACT-LCS at 3 months than on the 60Gy arm (45% vs. 30%, p=0.02). At 12 months, fewer patients who received IMRT (vs 3DCRT) had clinically meaningful decline in FACT-LCS (21% vs 46%, p=0.003). Baseline FACT-TOI was associated with overall survival in

  12. Effect of radiation quality on mutagenic joining of enzymatically-induced DNA double-strand breaks in previously irradiated human cells.

    Science.gov (United States)

    Li, Zhentian; Wang, Huichen; Wang, Ya; Murnane, John P; Dynan, William S

    2014-11-01

    Previous work has shown that high charge and energy particle irradiation of human cells evokes a mutagenic repair phenotype, defined by increased mutagenic repair of new double-strand breaks that are introduced enzymatically, days or weeks after the initial irradiation. The effect was seen originally with 600 MeV/u (56)Fe particles, which have a linear energy transfer (LET) value of 174 keV/μm, but not with X rays or γ rays (LET ≤ 2 keV/μm). To better define the radiation quality dependence of the phenomenon, we tested two ions with intermediate LET values, 1,000 MeV/u (48)Ti (LET = 108 keV/μm) and 300 MeV/u (28)Si (LET = 69 keV/μm). These experiments used a previously validated assay, where a rare-cutting nuclease introduces double-strand breaks in two reporter transgene cassettes, which are located on different chromosomes. Deletions of a block of sequence in one of the cassettes, or translocations between cassettes, are measured independently using a multicolor fluorescence assay. The results showed that (48)Ti was a potent, but transient, inducer of mutagenic repair, based on increased frequency of nuclease-induced translocations. The (48)Ti ions did not affect the frequency of nuclease-induced deletions. The (28)Si ions had no measurable effect on either endpoint. There was a close correlation between the induction of the mutagenic repair phenomenon and the frequency of micronuclei in the targeted population (R(2) = 0.74), whereas there was no apparent correlation with radiation-induced cell inactivation. Together, these results better define the radiation quality dependence of the mutagenic repair phenomenon and establish its correlation, or lack of correlation, with other endpoints.

  13. [The application of total quality management (TQM) in quality management of radiation therapy].

    Science.gov (United States)

    Jiang, Rui-yao; Fu, Shen; Li, Bin

    2009-03-01

    The strategies and methods of the total quality management (TQM) need to applied in quality management of radiation therapy. We should improve the level of quality control and quality assurance in radiation therapy. By establishing quality control system in radiation therapy, standardization of radiation therapy workflow, strengthening quality control of devices and physical technique and paying attention to safety protection and staff training.

  14. Cell Phone RF Radiation

    Science.gov (United States)

    Abdul-Razzaq, Wathiq

    2015-01-01

    In a recent article in "Physics Today," Meredith and Redish emphasized the need to make introductory physics courses beneficial for life sciences majors. In this study, a lab activity is proposed to measure the intensity of electromagnetic waves emitted by cell phones and connect these measurements to various standards, biological…

  15. Radiation quality factor of spherical antennas with material cores

    DEFF Research Database (Denmark)

    Hansen, Troels Vejle; Kim, Oleksiy S.; Breinbjerg, Olav

    2011-01-01

    This paper gives a description of the radiation quality factor and resonances of spherical antennas with material cores. Conditions for cavity and radiating resonances are given, and a theoretical description of the radiation quality factor, as well as simple expressions describing the relative...

  16. 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.

  17. Space radiation effects on plant and mammalian cells

    Science.gov (United States)

    Arena, C.; De Micco, V.; Macaeva, E.; Quintens, R.

    2014-11-01

    The study of the effects of ionizing radiation on organisms is related to different research aims. The current review emphasizes the studies on the effects of different doses of sparsely and densely ionizing radiation on living organisms, with the final purpose of highlighting specific and common effects of space radiation in mammals and plants. This topic is extremely relevant in the context of radiation protection from space environment. The response of different organisms to ionizing radiation depends on the radiation quality/dose and/or the intrinsic characteristics of the living system. Macromolecules, in particular DNA, are the critical targets of radiation, even if there is a strong difference between damages encountered by plant and mammalian cells. The differences in structure and metabolism between the two cell types are responsible for the higher resistance of the plant cell compared with its animal counterpart. In this review, we report some recent findings from studies performed in Space or on Earth, simulating space-like levels of radiation with ground-based facilities, to understand the effect of ionizing radiation on mammalian and plant cells. In particular, our attention is focused on genetic alterations and repair mechanisms in mammalian cells and on structures and mechanisms conferring radioresistance to plant cells.

  18. Cell-cycle radiation response: Role of intracellular factors

    Science.gov (United States)

    Blakely, E.; Chang, P.; Lommel, L.; Bjornstad, K.; Dixon, M.; Tobias, C.; Kumar, K.; Blakely, W. F.

    We have been studying variations of radiosensitivity and endogenous cellular factors during the course of progression through the human and hamster cell cycle. After exposure to low-LET radiations, the most radiosensitive cell stages are mitosis and the G1/S interface. The increased activity of a specific antioxidant enzyme such as superoxide dismutase in G1-phase, and the variations of endogenous thiols during cell division are thought to be intracellular factors of importance to the radiation survival response. These factors may contribute to modifying the age-dependent yield of lesions or more likely, to the efficiency of the repair processes. These molecular factors have been implicated in our cellular measurements of the larger values for the radiobiological oxygen effect late in the cycle compared to earlier cell ages. Low-LET radiation also delays progression through S phase which may allow more time for repair and hence contribute to radioresistance in late-S-phase. The cytoplasmic and intranuclear milieu of the cell appears to have less significant effects on lesions produced by high-LET radiation compared to those made by low-LET radiation. High-LET radiation fails to slow progression through S phase, and there is much less repair of lesions evident at all cell ages; however, high-LET particles cause a more profound block in G2 phase than that observed after low-LET radiation. Hazards posed by the interaction of damage from sequential doses of radiations of different qualities have been evaluated and are shown to lead to a cell-cycle-dependent enhancement of radiobiological effects. A summary comparison of various cell-cycle-dependent endpoints measured with low-or high-LET radiations is given and includes a discussion of the possible additional effects introduced by microgravity.

  19. Radiation Enhances Regulatory T Cell Representation

    Energy Technology Data Exchange (ETDEWEB)

    Kachikwu, Evelyn L.; Iwamoto, Keisuke S.; Liao, Yu-Pei; DeMarco, John J.; Agazaryan, Nzhde [Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Economou, James S. [Department of Surgical Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); McBride, William H. [Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Schaue, Doerthe, E-mail: dschaue@mednet.ucla.edu [Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States)

    2011-11-15

    Purpose: Immunotherapy could be a useful adjunct to standard cytotoxic therapies such as radiation in patients with micrometastatic disease, although successful integration of immunotherapy into treatment protocols will require further understanding of how standard therapies affect the generation of antitumor immune responses. This study was undertaken to evaluate the impact of radiation therapy (RT) on immunosuppressive T regulatory (Treg) cells. Methods and Materials: Treg cells were identified as a CD4{sup +}CD25{sup hi}Foxp3{sup +} lymphocyte subset, and their fate was followed in a murine TRAMP C1 model of prostate cancer in mice with and without RT. Results: CD4{sup +}CD25{sup hi}Foxp3{sup +} Treg cells increased in immune organs after local leg or whole-body radiation. A large part, but not all, of this increase after leg-only irradiation could be ascribed to radiation scatter and Treg cells being intrinsically more radiation resistant than other lymphocyte subpopulations, resulting in their selection. Their functional activity on a per-cell basis was not affected by radiation exposure. Similar findings were made with mice receiving local RT to murine prostate tumors growing in the leg. The importance of the Treg cell population in the response to RT was shown by systemic elimination of Treg cells, which greatly enhanced radiation-induced tumor regression. Conclusions: We conclude that Treg cells are more resistant to radiation than other lymphocytes, resulting in their preferential increase. Treg cells may form an important homeostatic mechanism for tissues injured by radiation, and in a tumor context, they may assist in immune evasion during therapy. Targeting this population may allow enhancement of radiotherapeutic benefit through immune modulation.

  20. The myth of cell phone radiation

    CERN Document Server

    Natarajan, Vasant

    2012-01-01

    We discuss the purported link between cell phone radiation and cancer. We show that it is inconsistent with the photoelectric effect, and that epidemiological studies of any link have no scientific basis.

  1. High Radiation Resistance IMM Solar Cell

    Science.gov (United States)

    Pan, Noren

    2015-01-01

    Due to high launch costs, weight reduction is a key driver for the development of new solar cell technologies suitable for space applications. This project is developing a unique triple-junction inverted metamorphic multijunction (IMM) technology that enables the manufacture of very lightweight, low-cost InGaAsP-based multijunction solar cells. This IMM technology consists of indium (In) and phosphorous (P) solar cell active materials, which are designed to improve the radiation-resistant properties of the triple-junction solar cell while maintaining high efficiency. The intrinsic radiation hardness of InP materials makes them of great interest for building solar cells suitable for deployment in harsh radiation environments, such as medium Earth orbit and missions to the outer planets. NASA Glenn's recently developed epitaxial lift-off (ELO) process also will be applied to this new structure, which will enable the fabrication of the IMM structure without the substrate.

  2. 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.

  3. Sound quality prediction for engine-radiated noise

    Science.gov (United States)

    Liu, Hai; Zhang, Junhong; Guo, Peng; Bi, Fengrong; Yu, Hanzhengnan; Ni, Guangjian

    2015-05-01

    Diesel engine-radiated noise quality prediction is an important topic because engine noise has a significant impact on the overall vehicle noise. Sound quality prediction is based on subjective and objective evaluation of engine noise. The integrated satisfaction index (ISI) is proposed as a criterion for differentiate noise quality in the subjective evaluation, and five psychoacoustic parameters are selected for characterizing and analyzing the noise quality of the diesel engine objectively. The combination of support vector machines (SVM) and genetic algorithm (GA) is proposed in order to establish a model for predicting the diesel engine-radiated noise quality for all operation conditions. The performance of the GA-SVM model is compared with the BP neural network model, and the results show that the mean relative error of the GA-SVM model is smaller than the BP neural network model. The importance rank of the sound quality metrics to the ISI is indicated by the non-parametric correlation analysis. This study suggests that the GA-SVM model is very useful for accurately predicting the diesel engine-radiated noise quality.

  4. Breast cancer stem cells and radiation

    Science.gov (United States)

    Phillips, Tiffany Marie

    2007-12-01

    The present studies explore the response of breast cancer stem cells (BCSC's) to radiation and the implications for clinical cancer treatment. Current cancer therapy eliminates bulky tumor mass but may fail to eradicate a critical tumor initiating cell population termed "cancer stem cells". These cells are potentially responsible for tumor formation, metastasis, and recurrence. Recently cancer stem cells have been prospectively identified in various malignancies, including breast cancer. The breast cancer stem cell has been identified by the surface markers CD44+/CD24 -(low). In vitro mammosphere cultures allow for the enrichment of the cancer stem cell population and were utilized in order to study differential characteristics of BCSC's. Initial studies found that BCSC's display increased radiation resistance as compared to other non-stem tumor cells. This resistance was accompanied by decreased H2AX phosphorylation, decreased reactive oxygen species formation, and increased phosphorylation of the checkpoint protein Chk1. These studies suggest differential DNA damage and repair within the BCSC population. Studies then examined the consequences of fractionated radiation on the BCSC population and found a two-fold increase in BCSC's following 5 x 3Gy. This observation begins to tie cancer stem cell self-renewal to the clinical stem cell phenomenon of accelerated repopulation. Accelerated repopulation is observed when treatment gaps increase between sequential fractions of radiotherapy and may be due to cancer stem cell symmetric self-renewal. The balance between asymmetric and symmetric stem cell division is vital for proper maintenance; deregulation is likely linked to cancer initiation and progression. The developmental Notch-1 pathway was found to regulate BCSC division. Over-expressing the constitutively active Notch-1-ICD in MCF7 cells produced an increase in the BCSC population. Additionally, radiation was observed to increase the expression of the Notch-1

  5. Radiation Dosimetry for Quality Control of Food Preservation and Disinfestation

    DEFF Research Database (Denmark)

    McLaughlin, W.L.; Miller, Arne; Uribe, R.M.

    1983-01-01

    In the use of x and gamma rays and scanned electron beams to extend the shelf life of food by delay of sprouting and ripening, killing of microbes, and control of insect population, quality assurance is provided by standardized radiation dosimetry. By strategic placement of calibrated dosimeters...

  6. Quality Characteristics of Dried Bananas Produced with Infrared Radiation Technology

    Science.gov (United States)

    Browning of fruits during drying is a major quality concern. The enzyme polyphenol oxidase has been found to be the main cause of browning in bananas. Infrared radiation (IR) drying could be used to minimize enzymatic browning hence eliminating the need for pre-treatments. This study was to inves...

  7. [Influence of Detector Radiation Damage on CR Mammography Quality Control].

    Science.gov (United States)

    Moriwaki, Atsumi; Ishii, Mie; Terazono, Shiho; Arao, Keiko; Ishii, Rie; Sanada, Taizo; Yoshida, Akira

    2016-05-01

    Recently, radiation damage to the detector apparatus employed in computed radiography (CR) mammography has become problematic. The CR system and the imaging plate (IP) applied to quality control (QC) program were also used in clinical mammography in our hospital, and the IP to which radiation damage has occurred was used for approximately 5 years (approximately 13,000 exposures). We considered using previously acquired QC image data, which is stored in a server, to investigate the influence of radiation damage to an IP. The mammography unit employed in this study was a phase contrast mammography (PCM) Mermaid (KONICA MINOLTA) system. The QC image was made newly, and it was output in the film, and thereafter the optical density of the step-phantom image was measured. An input (digital value)-output (optical density) conversion curve was plotted using the obtained data. The digital values were then converted to optical density values using a reference optical density vs. digital value curve. When a high radiation dose was applied directly, radiation damage occurred at a position on the IP where no object was present. Daily QC for mammography is conducted using an American College of Radiology (ACR) accreditation phantom and acrylic disc, and an environmental background density measurement is performed as one of the management indexes. In this study, the radiation damage sustained by the acrylic disc was shown to differ from that of the background. Thus, it was revealed that QC results are influenced by radiation damage.

  8. Atypical radiation response of SCID cells

    Science.gov (United States)

    Chawapun, Nisa

    Murine SCID (severe combined immune deficiency) cells are well known for their defect in DNA double-strand break repair and in variable(diversity)joining [V(D)J] recombination due to a mutation in a catalytic subunit of DNA-dependent protein kinase (DNA-PKcs). As a consequence, scid cells are hypersensitive to ionizing radiation. The present study showed that asynchronous populations of scid cells were about two-fold more sensitive than Balb/c with respect to cell killing and the defect in scid cells was corrected by complementation with human chromosome 8. Analysis of the survival of synchronized populations as a function of the cell cycle revealed that while scid cells were hypersensitive in all cell cycle phases compared to wild-type cells, this hypersensitivity is even more pronounced in G1 phase. The hypersensitivity reduced as the cells progressed into S phase suggested that homologous recombination repair plays a role. The results imply that there are at least two pathways for the repair of DSB DNA, consistent with a model previously proposed by others. The scid cells were also more sensitive to UVC light (254 nm) killing as compared to wild type cells by clonogenic survival. Using a host cell reactivation (HCR) assay to study the nucleotide excision repair (NER) which is the major repair pathway for UV-photoproducts, the results showed that NER in scid cells was not as efficient as CB- 17. This suggests that DNA-PK is involved in NER as well as non-homologous end-joining (NHEJ) DSB repair which is responsible for ionizing radiation sensitivity in scid cells. Repair in scid cells was not totally absent as shown by low dose rate sparing of cell killing after exposure to 137Cs γ-rays at dose rate of 0.6 cGy/h, 1.36 cGy/h, 6 cGy/h as compared to high dose rate at 171 cGy/min, although this phenomenon could be explained partly by proliferation. However, for radiation induced transformation, no significant dose rate effect was seen. A plot of transformation

  9. Quality management system in the CIEMAT Radiation Dosimetry Service.

    Science.gov (United States)

    Martín, R; Navarro, T; Romero, A M; López, M A

    2011-03-01

    This paper describes the activities realised by the CIEMAT Radiation Dosimetry Service (SDR) for the implementation of a quality management system (QMS) in order to achieve compliance with the requirements of ISO/IEC 17025 and to apply for the accreditation for testing measurements of radiation dose. SDR has decided the accreditation of the service as a whole and not for each of its component laboratories. This makes it necessary to design a QMS common to all, thus ensuring alignment and compliance with standard requirements, and simplifying routine works as possible.

  10. Baseline Surface Radiation Network (BSRN) quality control of solar radiation data on the Gangneung-Wonju National University radiation station

    Science.gov (United States)

    Zo, Il-Sung; Jee, Joon-Bum; Kim, Bu-Yo; Lee, Kyu-Tae

    2017-02-01

    Gangneung-Wonju National University (GWNU) radiation station has been collecting data on global, direct, and diffuse solar radiation since 2011. We conducted a quality control (QC) assessment of GWNU data collected between 2012 and 2014, using procedures outlined by the Baseline Surface Radiation Network (BSRN). The QC process involved the comparison of observations, the correction of observational equipment, the examination of physically possible limits, and the comparative testing of observations and model calculations. Furthermore, we performed a shading check of the observational environment around the GWNU solar station. For each solar radiation element (observed every minute), we performed a QC check and investigated any flagged problems. 98.31% of the data were classified as good quality, while the remaining 1.69% were flagged as bad quality based on the shading check and comparison tests. We then compared the good-quality data to the global solar radiation data observed at the Gangwon Regional Office of Meteorology (GROM). After performing this comparison, the determination coefficient (R2; 0.98) and standard deviation (SD; 0.92 MJ m-2) increased compared to those computed before the QC check (0.97 and 1.09 MJ m-2). Even considering the geographical differences and weather effects between the two stations, these results are statistically significant. However, we also confirmed that the quality of the GROM data deteriorated in relation to weather conditions because of poor maintenance. Hence, we conclude that good-quality observational data rely on the maintenance of both observational equipment and the surrounding environment under optimal conditions.

  11. Effect of gamma radiation on honey quality control

    Science.gov (United States)

    Bera, A.; Almeida-Muradian, L. B.; Sabato, S. F.

    2009-07-01

    Honey is one of the most complex substances produced by bees, mainly from the nectar of flowers. Gamma radiation is a technique that can be used to decrease the number of microbiological problems associated with food and increase the shelf life of certain products. The objective of this study was to verify the effect of gamma radiation with source of cobalto-60 (10 kGy) on some parameters used in honey quality control. Seven samples of pure honey were obtained from local markets in Sao Paulo, Brazil, in 2007. The methods used are in accordance with Brazilian Regulations. The physicochemical parameters analyzed were: moisture, HMF, free acidity, pH, sugars and ash. The results showed that gamma radiation, in the dose mentioned above, did not cause significant physicochemical alterations.

  12. Effect of gamma radiation on honey quality control

    Energy Technology Data Exchange (ETDEWEB)

    Bera, A. [Radiation Technology Center, IPEN-CNEN/SP, A. Lineu Prestes, 2242, 05508-000 Sao Paulo (Brazil)], E-mail: berale@usp.br; Almeida-Muradian, L.B. [Av. Prof. Lineu Prestes, 580-Cidade Universitaria, Sao Paulo (Brazil); Sabato, S.F. [Radiation Technology Center, IPEN-CNEN/SP, A. Lineu Prestes, 2242, 05508-000 Sao Paulo (Brazil)], E-mail: sfsabato@ipen.br

    2009-07-15

    Honey is one of the most complex substances produced by bees, mainly from the nectar of flowers. Gamma radiation is a technique that can be used to decrease the number of microbiological problems associated with food and increase the shelf life of certain products. The objective of this study was to verify the effect of gamma radiation with source of cobalto-60 (10 kGy) on some parameters used in honey quality control. Seven samples of pure honey were obtained from local markets in Sao Paulo, Brazil, in 2007. The methods used are in accordance with Brazilian Regulations. The physicochemical parameters analyzed were: moisture, HMF, free acidity, pH, sugars and ash. The results showed that gamma radiation, in the dose mentioned above, did not cause significant physicochemical alterations.

  13. Quality assurance of environmental gamma radiation monitoring in Slovenia.

    Science.gov (United States)

    Stuhec, M; Zorko, B; Mitić, D; Miljanić, S; Ranogajec-Komor, M

    2006-01-01

    Environmental gamma radiation monitoring established in Slovenia consists of a network of multifunctional gamma monitors (MFMs) based on pairs of Geiger-Müller counters and a network of measuring sites with high-sensitive thermoluminiscence dosemeters. The measuring points are evenly spread across Slovenia, located at the meteorological stations and more densely on additional locations around the Krsko NPP. The MFM network has a 2-fold function with one sensor used for the purpose of early warning system in near surroundings of the NPP and the other, more sensitive, for natural radiation monitoring. The paper summarises activities to establish quality assurance of the environmental gamma radiation measurements in Slovenia, with a critical view of the results in comparison with the international standards and recommendations. While the results of linearity and energy dependence tests were satisfying, on-field intercomparison showed that the inherent signal of one of the monitors (MFM) has to be taken into account in the range of environmental background radiation.

  14. Modeling cell dynamics under mobile phone radiation.

    Science.gov (United States)

    Minelli, Tullio Antonio; Balduzzo, Maurizio; Milone, Francesco Ferro; Nofrate, Valentina

    2007-04-01

    Perturbations by pulse-modulated microwave radiation from GSM mobile phones on neuron cell membrane gating and calcium oscillations have been suggested as a possible mechanism underlying activation of brain states and electroencephalographic epiphenomena. As the employ of UMTS phones seems to reveal other symptoms, a unified phenomenological framework is needed. In order to explain possible effects of mobile phone radiation on cell oscillations, GSM and UMTS low-frequency envelopes have been detected, recorded and used as input in cell models. Dynamical systems endowed with contiguous regular and chaotic regimes suitable to produce stochastic resonance can both account for the perturbation of the neuro-electrical activity and even for the low intensity of the signal perceived by high sensitive subjects. Neuron models of this kind can be employed as a reductionist hint for the mentioned phenomenology. The Hindmarsh-Rose model exhibits frequency enhancement and regularization phenomena induced by weak GSM and UMTS. More realistic simulations of cell membrane gating and calcium oscillations have been performed with the help of an adaptation of the Chay-Keizer dynamical system. This scheme can explain the suspected subjective sensitivity to mobile phone signals under the thermal threshold, in terms of cell calcium regularity mechanisms. Concerning the two kinds of emission, the stronger occupation of the ELF band of last generation UMTS phones is compensated by lower power emitted.

  15. Ionizing Radiation in Glioblastoma Initiating Cells

    Directory of Open Access Journals (Sweden)

    Maricruz eRivera

    2013-04-01

    Full Text Available Glioblastoma is the most common primary malignant brain tumor in adults with a median survival of 12-15 months with treatment consisting of surgical resection followed by ionizing radiation (IR and chemotherapy. Even aggressive treatment is often palliative due to near universal recurrence. Therapeutic resistance has been linked to a subpopulation of GBM cells with stem-cell like properties termed glioblastoma initiating cells (GICs. Recent efforts have focused on elucidating resistance mechanisms activated in GICs in response to IR. Among these, GICs preferentially activate the DNA damage response (DDR to result in a faster rate of double-strand break (DSB repair induced by IR as compared to the bulk tumor cells. IR also activates NOTCH and the hepatic growth factor (HGF receptor, c-MET, signaling cascades that play critical roles in promoting proliferation, invasion, and resistance to apoptosis. These pathways are preferentially activated in GICs and represent targets for pharmacologic intervention. While IR provides the benefit of improved survival, it paradoxically promotes selection of more malignant cellular phenotypes of glioblastoma. As reviewed here, finding effective combinations of radiation and molecular inhibitors to target GICs and non-GICs is essential for the development of more effective therapies.

  16. Radiation Quality Effects on Transcriptome Profiles in 3-d Cultures After Particle Irradiation

    Science.gov (United States)

    Patel, Z. S.; Kidane, Y. H.; Huff, J. L.

    2014-01-01

    In this work, we evaluate the differential effects of low- and high-LET radiation on 3-D organotypic cultures in order to investigate radiation quality impacts on gene expression and cellular responses. Reducing uncertainties in current risk models requires new knowledge on the fundamental differences in biological responses (the so-called radiation quality effects) triggered by heavy ion particle radiation versus low-LET radiation associated with Earth-based exposures. We are utilizing novel 3-D organotypic human tissue models that provide a format for study of human cells within a realistic tissue framework, thereby bridging the gap between 2-D monolayer culture and animal models for risk extrapolation to humans. To identify biological pathway signatures unique to heavy ion particle exposure, functional gene set enrichment analysis (GSEA) was used with whole transcriptome profiling. GSEA has been used extensively as a method to garner biological information in a variety of model systems but has not been commonly used to analyze radiation effects. It is a powerful approach for assessing the functional significance of radiation quality-dependent changes from datasets where the changes are subtle but broad, and where single gene based analysis using rankings of fold-change may not reveal important biological information. We identified 45 statistically significant gene sets at 0.05 q-value cutoff, including 14 gene sets common to gamma and titanium irradiation, 19 gene sets specific to gamma irradiation, and 12 titanium-specific gene sets. Common gene sets largely align with DNA damage, cell cycle, early immune response, and inflammatory cytokine pathway activation. The top gene set enriched for the gamma- and titanium-irradiated samples involved KRAS pathway activation and genes activated in TNF-treated cells, respectively. Another difference noted for the high-LET samples was an apparent enrichment in gene sets involved in cycle cycle/mitotic control. It is

  17. Cancer stem cells, cancer cell plasticity and radiation therapy.

    Science.gov (United States)

    Vlashi, Erina; Pajonk, Frank

    2015-04-01

    Since the first prospective identification of cancer stem cells in solid cancers the cancer stem cell hypothesis has reemerged as a research topic of increasing interest. It postulates that solid cancers are organized hierarchically with a small number of cancer stem cells driving tumor growth, repopulation after injury and metastasis. They give rise to differentiated progeny, which lack these features. The model predicts that for any therapy to provide cure, all cancer stem cells have to be eliminated while the survival of differentiated progeny is less critical. In this review we discuss recent reports challenging the idea of a unidirectional differentiation of cancer cells. These reports provide evidence supporting the idea that non-stem cancer cells exhibit a remarkable degree of plasticity that allows them to re-acquire cancer stem cell traits, especially in the context of radiation therapy. We summarize conditions under which differentiation is reversed and discuss the current knowledge of the underlying mechanisms.

  18. Cell/Tissue Culture Radiation Exposure Facility Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a Cell/Tissue Culture Radiation Exposure Facility (CTC-REF) to enable radiobiologists to investigate the real-time radiation effects on...

  19. 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

  20. Tumourigenicity and radiation resistance of mesenchymal stem cells

    DEFF Research Database (Denmark)

    D'Andrea, Filippo Peder; Horsman, Michael Robert; Kassem, Moustapha

    2012-01-01

    Background. Cancer stem cells are believed to be more radiation resistant than differentiated tumour cells of the same origin. It is not known, however, whether normal nontransformed adult stem cells share the same radioresistance as their cancerous counterpart. Material and methods....... Nontumourigenic (TERT4) and tumourigenic (TRET20) cell lines, from an immortalised mesenchymal stem cell line, were grown in culture prior to irradiation and gene expression analysis. Radiation resistance was measured using a clonogenic assay. Differences in gene expression between the two cell lines, both under...... the intercellular matrix. These results also indicate that cancer stem cells are more radiation resistant than stem cells of the same origin....

  1. Radiation dose reduction without degrading image quality during computed tomography examinations: Dosimetry and quality control study

    Directory of Open Access Journals (Sweden)

    George Felix Acquah

    2014-08-01

    Full Text Available Purpose: Computed tomography (CT, is an X-ray procedure that generates high quality cross-sectional images of the body, and by comparison to other radiological diagnosis, is responsible for higher doses to patients. This work studies the doses and image qualities produced from the default primary scanning factors of a Siemens CT machine and afterwards came up with scanning protocols that allow radiologists to obtain the necessary diagnostic information while reducing radiation doses to as low as reasonably achievable. Methods: Approximately 1000 CT scans from mostly common examinations; head, thorax, abdomen and pelvis routines were selected and analyzed for their image quality and radiation doses over a two year interval. Dose measurements were performed for the same routines using Computed Tomography Dose Index (CTDI phantoms, RTI barracuda system with electrometer, and CT dose Profiler detector to evaluate the doses delivered during these CT procedures. Subsequently, image quality checks were performed using the CT Catphan 600 and anthropomorphic phantoms. CTDI and Dose Length Product (DLP values were calculated for each scan. From analyzing these measurements, the appropriate machine scanning parameters were adjusted to reduce radiation does while at the same time providing good image quality.Results: Doses to patients using the default head sequence protocol had an average CTDIvol value of 65.45 mGy and a range of 7.10-16.80 mGy for thorax, abdomen and pelvis examinations whiles the new protocol had an average CTDIvol of 58.32 mGy for the head and a range of 3.83-15.24 mGy for the truck region. The DLP value for default head scans decreased from an average of 2279.85 mGy.cm to 874.53 mGy.cm with the new protocol. Tube potentials (KV and tube current-time (mAs had an effect on spatial resolution and low contrast detectability as well as doses. Conclusion: From the new protocols, lower values of KV and mAs together with other factors were

  2. Development of quality assurance procedures for production of sealed radiation source

    CERN Document Server

    Nam, J H; Cho, W K; Han, H S; Hong, S B; Kim, K H; Kim, S D; Lee, Y G; Lim, N J

    2001-01-01

    The quality assurance procedures for sealed radiation sources production using HANARO and RIPF have been developed. The detailed quality assurance procedures are essential to manage the whole work process effectively and ensure the quality of the produced sealed sources. Through applying this quality assurance procedures to the entire production works of the sealed radiation sources, it is expected that the quality of the products, the safety of the works and the satisfaction of the customers will be increased.

  3. Radiation dose and image quality for paediatric interventional cardiology

    Energy Technology Data Exchange (ETDEWEB)

    Vano, E [Radiology Department, Medicine School, Complutense University and San Carlos University Hospital, 28040 Madrid (Spain); Ubeda, C [Clinical Sciences Department, Faculty of the Science of Health, Tarapaca University, 18 de Septiembre 2222, Arica (Chile); Leyton, F [Institute of Public Health of Chile, Marathon 1000, Nunoa, Santiago (Chile); Miranda, P [Hemodynamic Department, Cardiovascular Service, Luis Calvo Mackenna Hospital, Avenida Antonio Varas 360, Providencia, Santiago (Chile)], E-mail: eliseov@med.ucm.es

    2008-08-07

    Radiation dose and image quality for paediatric protocols in a biplane x-ray system used for interventional cardiology have been evaluated. Entrance surface air kerma (ESAK) and image quality using a test object and polymethyl methacrylate (PMMA) phantoms have been measured for the typical paediatric patient thicknesses (4-20 cm of PMMA). Images from fluoroscopy (low, medium and high) and cine modes have been archived in digital imaging and communications in medicine (DICOM) format. Signal-to-noise ratio (SNR), figure of merit (FOM), contrast (CO), contrast-to-noise ratio (CNR) and high contrast spatial resolution (HCSR) have been computed from the images. Data on dose transferred to the DICOM header have been used to test the values of the dosimetric display at the interventional reference point. ESAK for fluoroscopy modes ranges from 0.15 to 36.60 {mu}Gy/frame when moving from 4 to 20 cm PMMA. For cine, these values range from 2.80 to 161.10 {mu}Gy/frame. SNR, FOM, CO, CNR and HCSR are improved for high fluoroscopy and cine modes and maintained roughly constant for the different thicknesses. Cumulative dose at the interventional reference point resulted 25-45% higher than the skin dose for the vertical C-arm (depending of the phantom thickness). ESAK and numerical image quality parameters allow the verification of the proper setting of the x-ray system. Knowing the increases in dose per frame when increasing phantom thicknesses together with the image quality parameters will help cardiologists in the good management of patient dose and allow them to select the best imaging acquisition mode during clinical procedures.

  4. Radiation dose and image quality for paediatric interventional cardiology

    Science.gov (United States)

    Vano, E.; Ubeda, C.; Leyton, F.; Miranda, P.

    2008-08-01

    Radiation dose and image quality for paediatric protocols in a biplane x-ray system used for interventional cardiology have been evaluated. Entrance surface air kerma (ESAK) and image quality using a test object and polymethyl methacrylate (PMMA) phantoms have been measured for the typical paediatric patient thicknesses (4-20 cm of PMMA). Images from fluoroscopy (low, medium and high) and cine modes have been archived in digital imaging and communications in medicine (DICOM) format. Signal-to-noise ratio (SNR), figure of merit (FOM), contrast (CO), contrast-to-noise ratio (CNR) and high contrast spatial resolution (HCSR) have been computed from the images. Data on dose transferred to the DICOM header have been used to test the values of the dosimetric display at the interventional reference point. ESAK for fluoroscopy modes ranges from 0.15 to 36.60 µGy/frame when moving from 4 to 20 cm PMMA. For cine, these values range from 2.80 to 161.10 µGy/frame. SNR, FOM, CO, CNR and HCSR are improved for high fluoroscopy and cine modes and maintained roughly constant for the different thicknesses. Cumulative dose at the interventional reference point resulted 25-45% higher than the skin dose for the vertical C-arm (depending of the phantom thickness). ESAK and numerical image quality parameters allow the verification of the proper setting of the x-ray system. Knowing the increases in dose per frame when increasing phantom thicknesses together with the image quality parameters will help cardiologists in the good management of patient dose and allow them to select the best imaging acquisition mode during clinical procedures.

  5. Cone beam computed tomography radiation dose and image quality assessments.

    Science.gov (United States)

    Lofthag-Hansen, Sara

    2010-01-01

    Diagnostic radiology has undergone profound changes in the last 30 years. New technologies are available to the dental field, cone beam computed tomography (CBCT) as one of the most important. CBCT is a catch-all term for a technology comprising a variety of machines differing in many respects: patient positioning, volume size (FOV), radiation quality, image capturing and reconstruction, image resolution and radiation dose. When new technology is introduced one must make sure that diagnostic accuracy is better or at least as good as the one it can be expected to replace. The CBCT brand tested was two versions of Accuitomo (Morita, Japan): 3D Accuitomo with an image intensifier as detector, FOV 3 cm x 4 cm and 3D Accuitomo FPD with a flat panel detector, FOVs 4 cm x 4 cm and 6 cm x 6 cm. The 3D Accuitomo was compared with intra-oral radiography for endodontic diagnosis in 35 patients with 46 teeth analyzed, of which 41 were endodontically treated. Three observers assessed the images by consensus. The result showed that CBCT imaging was superior with a higher number of teeth diagnosed with periapical lesions (42 vs 32 teeth). When evaluating 3D Accuitomo examinations in the posterior mandible in 30 patients, visibility of marginal bone crest and mandibular canal, important anatomic structures for implant planning, was high with good observer agreement among seven observers. Radiographic techniques have to be evaluated concerning radiation dose, which requires well-defined and easy-to-use methods. Two methods: CT dose index (CTDI), prevailing method for CT units, and dose-area product (DAP) were evaluated for calculating effective dose (E) for both units. An asymmetric dose distribution was revealed when a clinical situation was simulated. Hence, the CTDI method was not applicable for these units with small FOVs. Based on DAP values from 90 patient examinations effective dose was estimated for three diagnostic tasks: implant planning in posterior mandible and

  6. Objective assessment of image quality VI: imaging in radiation therapy

    Science.gov (United States)

    Barrett, Harrison H.; Kupinski, Matthew A.; Müeller, Stefan; Halpern, Howard J.; Morris, John C., III; Dwyer, Roisin

    2013-11-01

    Earlier work on objective assessment of image quality (OAIQ) focused largely on estimation or classification tasks in which the desired outcome of imaging is accurate diagnosis. This paper develops a general framework for assessing imaging quality on the basis of therapeutic outcomes rather than diagnostic performance. By analogy to receiver operating characteristic (ROC) curves and their variants as used in diagnostic OAIQ, the method proposed here utilizes the therapy operating characteristic or TOC curves, which are plots of the probability of tumor control versus the probability of normal-tissue complications as the overall dose level of a radiotherapy treatment is varied. The proposed figure of merit is the area under the TOC curve, denoted AUTOC. This paper reviews an earlier exposition of the theory of TOC and AUTOC, which was specific to the assessment of image-segmentation algorithms, and extends it to other applications of imaging in external-beam radiation treatment as well as in treatment with internal radioactive sources. For each application, a methodology for computing the TOC is presented. A key difference between ROC and TOC is that the latter can be defined for a single patient rather than a population of patients.

  7. Occurrence of BOOP outside radiation field after radiation therapy for small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hamanishi, Tohru; Oida, Kazukiyo [Tenri Hospital, Nara (Japan); Morimatu, Takafumi (and others)

    2001-09-01

    We report a case of bronchiolitis obliterans organizing pneumonia (BOOP) that occurred outside the radiation field after radiation therapy for small cell lung cancer. A 74-year-old woman received chemotherapy and a total of 60 Gy of radiation therapy to the right hilum and mediastinum for small cell carcinoma of the suprahilar area of the right lung. Radiation pneumonitis developed within the radiation port 3 months after the completion of radiation therapy. She complained of cough and was admitted 7 months after completion of the radiation therapy. Chest radiography and computed tomography demonstrated peripheral alveolar opacities outside the radiation field on the side contralateral to that receiving the radiation therapy. Bronchoalveolar lavage showed that the total cell count was increased, with a markedly increased percentage of lymphocytes. Transbronchial lung biopsy revealed a histologic pattern consistent with BOOP. Treatment with corticosteroids resulted in rapid improvement of the symptoms and complete resolution of the radiographic abnormalities of the left lung. Although some cases of BOOP following radiation therapy for breast cancer have been reported, none of BOOP after radiation therapy for lung cancer have appeared in the literature. (author)

  8. Quality cell therapy manufacturing by design.

    Science.gov (United States)

    Lipsitz, Yonatan Y; Timmins, Nicholas E; Zandstra, Peter W

    2016-04-01

    Transplantation of live cells as therapeutic agents is poised to offer new treatment options for a wide range of acute and chronic diseases. However, the biological complexity of cells has hampered the translation of laboratory-scale experiments into industrial processes for reliable, cost-effective manufacturing of cell-based therapies. We argue here that a solution to this challenge is to design cell manufacturing processes according to quality-by-design (QbD) principles. QbD integrates scientific knowledge and risk analysis into manufacturing process development and is already being adopted by the biopharmaceutical industry. Many opportunities to incorporate QbD into cell therapy manufacturing exist, although further technology development is required for full implementation. Linking measurable molecular and cellular characteristics of a cell population to final product quality through QbD is a crucial step in realizing the potential for cell therapies to transform healthcare.

  9. 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

  10. Study of radiation effects on mammalian cells in vitro

    Science.gov (United States)

    Sinclair, W. K.

    1968-01-01

    Radiation effect on single cells and cell populations of Chinese hamster lung tissue is studied in vitro. The rate and position as the cell progresses through the generation cycle shows division delay, changes in some biochemical processes in the cell, chromosomal changes, colony size changes, and loss of reproductive capacity.

  11. Radiation sensitivity of Merkel cell carcinoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, J.H.; Ramsay, J.R.; Birrell, G.W. [Queensland Institute of Medical Research (Australia)] [and others

    1995-07-30

    Merkel cell carcinoma (MCC), being a small cell carcinoma, would be expected to be sensitive to radiation. Clinical analysis of patients at our center, especially those with macroscopic disease, would suggest the response is quite variable. We have recently established a number of MCC cell lines from patients prior to radiotherapy, and for the first time are in a position to determine their sensitivity under controlled conditions. Some of the MCC lines grew as suspension cultures and could not be single cell cloned; therefore, it was not possible to use clonogenic survival for all cell lines. A tetrazolium based (MTT) assay was used for these lines, to estimate cell growth after {gamma} irradiation. Control experiments were conducted on lymphoblastoid cell lines (LCL) and the adherent MCC line, MCC13, to demonstrate that the two assays were comparable under the conditions used. We have examined cell lines from MCC, small cell lung cancer (SCLC), malignant melanomas, Epstein Barr virus (EBV) transformed lymphocytes (LCL), and skin fibroblasts for their sensitivity to {gamma} irradiation using both clonogenic cell survival and MTT assays. The results show that the tumor cell lines have a range of sensitivities, with melanoma being more resistant (surviving fraction at 2 Gy (SF2) 0.57 and 0.56) than the small cell carcinoma lines, MCC (SF2 range 0.21-0.45, mean SF2 0.30, n = 8) and SCLC (SF2 0.31). Fibroblasts were the most sensitive (SF2 0.13-0.20, mean 0.16, n = 5). The MTT assay, when compared to clonogenic assay for the MCC13 adherent line and the LCL, gave comparable results under the conditions used. Both assays gave a range of SF2 values for the MCC cell lines, suggesting that these cancers would give a heterogeneous response in vivo. The results with the two derivative clones of MCC14 (SF2 for MCC14/1 0.38, MCC14/2 0.45) would further suggest that some of them may develop resistance during clonogenic evolution. 25 refs., 3 figs., 1 tab.

  12. DNA repair and radiation sensitivity in mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Chen, D.J.C.; Stackhouse, M. [Los Alamos National Lab., NM (United States); Chen, D.S. [Rochester Univ., NY (United States). Dept. of Radiation Oncology

    1993-02-01

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

  13. DNA repair and radiation sensitivity in mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Chen, D.J.C.; Stackhouse, M. (Los Alamos National Lab., NM (United States)); Chen, D.S. (Rochester Univ., NY (United States). Dept. of Radiation Oncology)

    1993-01-01

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

  14. Thermal radiosensitization in radiation-sensitive mutant mouse leukemic cells

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Toshikazu (Hiroshima Univ. (Japan). School of Dentistry)

    1994-06-01

    This study investigated thermal, radiation, and combined thermal radiation sensitization of mouse leukemic cells, L5178Y, and radiation-sensitive mutant cells, LX830. Radiation sensitivity (D[sub 0]) values were 0.41 Gy for LX830 and 1.39 Gy for L5178Y, with the ratio of D[sub 0] values in LX830 to in L5178Y being 3.4. Thus, LX830 was more radiosensitive than L5178Y. LX830 showed no shouldered survival curves. Although sublethal damage (SLD) repair was seen to the almost same degree in both LX830 and L5178Y, potential lethal damage (PLD) repair was scarcely observed in LX830. Both cell lines were similar in thermal sensitivity (T[sub 0]). Eosine staining suggested that cell killing due to hyperthermia had occurred in the interphase in both LX830 and L5178Y. L5178Y showed thermal sensitivity low in the G1 phase and high in the S phase; on the contrary, LX830 showed it high in the G1 phase and low in the S phase. Thermal radiosensitization was similar in both cell lines, although there was a great difference in radiation sensitivity between the cell lines. The difference in radiation sensitivity (D[sub 0]) between L5178Y and LX830 became small when radiation was given at the time of the maximum thermal resistance. This seemed to contribute to a decrease in radiation sensitivity in LX830. It can be concluded that thermal radiosensitization depends on thermal sensitivity and that radiation sensitivity decreases in radiation-sensitive cells when exposed to irradiation at the time of thermal resistance. (N.K.).

  15. Losartan sensitizes selectively prostate cancer cell to ionizing radiation.

    Science.gov (United States)

    Yazdannejat, H; Hosseinimehr, S J; Ghasemi, A; Pourfallah, T A; Rafiei, A

    2016-01-11

    Losartan is an angiotensin II receptor (AT-II-R) blocker that is widely used by human for blood pressure regulation. Also, it has antitumor property. In this study, we investigated the radiosensitizing effect of losartan on cellular toxicity induced by ionizing radiation on prostate cancer and non-malignant fibroblast cells. Human prostate cancer (DU-145) and human non-malignant fibroblast cells (HFFF2) were treated with losartan at different concentrations (0.5, 1, 10, 50 and 100 µM) and then these cells were exposed to ionizing radiation. The cell proliferation was determined using MTT assay. Our results showed that losartan exhibited antitumor effect on prostate cancer cells; it was reduced cell survival to 66% at concentration 1 µM. Losartan showed an additive killing effect in combination with ionizing radiation on prostate cancer cell. The cell proliferation was reduced to 54% in the prostate cancer cells treated with losartan at concentration 1 µM in combination with ionizing radiation. Losartan did not exhibit any toxicity on HFFF2 cell. This result shows a promising effect of losartan on enhancement of therapeutic effect of ionizing radiation in patients during therapy.

  16. F-value as a chromosomal fingerprint of the quality of radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Masao S. [Kyoto Univ. (Japan). Radiation Biology Center

    1999-12-01

    Since the first proposal by Brenner and Sachs (Radiation Res. 140, 134-142, 1994), the F-value, the ratio of inter- to intra-chromosomal interchanges, as a biomarker for the quality of radiation has been a matter of repeated discussion. Controversies seem to stem from the selection of data which are heterogeneous in terms of chromosome scoring criteria and dose range. In the context of the critical evaluation of the validity of the F-value, the cytogenetic data obtained in our laboratory from the in vitro irradiation of human peripheral blood lymphocytes have been re-assessed for the F-value. The results were consistent with the original contention that the densely ionizing radiations showed lower F-value. The differential F-value was more pronounced in the low-dose range and disappeared with the increase of the dose, or more precisely with the number of charged particles passing through the cell nucleus. The range or charged particles also plays a role, which makes the F-value of neutrons insensitive to their energy due to a wide variation of the kinetic energy of recoil protons. (author)

  17. Open Cell Conducting Foams for High Synchrotron Radiation Beam Liners

    CERN Document Server

    Petracca, Stefania

    2014-01-01

    The possible use of open-cell conductive foams in high synchrotron radiation particle accelerator beam liners is considered. Available materials and modeling tools are reviewed, potential pros and cons are discussed, and preliminary conclusions are drawn.

  18. Effects of stratospheric radiations on human glioblastoma cells.

    Science.gov (United States)

    Cerù, Maria Paola; Amicarelli, Fernanda; Cristiano, Loredana; Colafarina, Sabrina; Aimola, Pierpaolo; Falone, Stefano; Cinque, Benedetta; Ursini, Ornella; Moscardelli, Roberto; Ragni, Pietro

    2005-01-01

    The aim of this work was to evaluate the effect of stratospheric radiations on neural tumour cells. ADF human glioblastoma cells were hosted on a stratospheric balloon within the 2002 biological experiment campaign of the Italian Space Agency. The flight at an average height of 37 km lasted about 24 hrs. Cell morphology, number and viability, cell cycle and apoptosis, some antioxidant enzymes and proteins involved in cell cycle regulation, DNA repair and gene expression were studied. Stratospheric radiations caused a significant decrease in cell number, as well as a block of proliferation, but not apoptosis or necrosis. Radiations also induced activation and induction of some antioxidant enzymes, increase in DNA repair-related proteins (p53 and Proliferating Cell Nuclear Antigen) and variations of the transcription factors Peroxisome Proliferator-Activated Receptors. Morphologically, test cells exhibited more electron dense cytoplasm and less condensed chromatin than controls and modification of their surfaces. Our results indicate that glioblastoma cells, exposed to continuous stratospheric radiations for 24 hrs, show activation of cell cycle check point, decrease of cell number, variations of Peroxisome Proliferator-Activated Receptors and increase of Reactive Oxygen Species-scavenging enzymes.

  19. Classical Radiation Reaction in Particle-In-Cell Simulations

    CERN Document Server

    Vranic, Marija; Fonseca, Ricardo A; Silva, Luis O

    2015-01-01

    Under the presence of ultra high intensity lasers or other intense electromagnetic fields the motion of particles in the ultrarelativistic regime can be severely affected by radiation reaction. The standard particle-in-cell (PIC) algorithms do not include radiation reaction effects. Even though this is a well known mechanism, there is not yet a definite algorithm nor a standard technique to include radiation reaction in PIC codes. We have compared several models for the calculation of the radiation reaction force, with the goal of implementing an algorithm for classical radiation reaction in the Osiris framework, a state-of-the-art PIC code. The results of the different models are compared with standard analytical results, and the relevance/advantages of each model are discussed. Numerical issues relevant to PIC codes such as resolution requirements, application of radiation reaction to macro particles and computational cost are also addressed. The Landau and Lifshitz reduced model is chosen for implementatio...

  20. Radiation-Induced Notch Signaling in Breast Cancer Stem Cells

    Energy Technology Data Exchange (ETDEWEB)

    Lagadec, Chann [Department of Radiation Oncology, David Geffen School of Medicine at University of California, Los Angeles (UCLA), Los Angeles, California (United States); Vlashi, Erina [Department of Radiation Oncology, David Geffen School of Medicine at University of California, Los Angeles (UCLA), Los Angeles, California (United States); Jonsson Comprehensive Cancer Center at UCLA, Los Angeles, California (United States); Alhiyari, Yazeed; Phillips, Tiffany M.; Bochkur Dratver, Milana [Department of Radiation Oncology, David Geffen School of Medicine at University of California, Los Angeles (UCLA), Los Angeles, California (United States); Pajonk, Frank, E-mail: fpajonk@mednet.ucla.edu [Department of Radiation Oncology, David Geffen School of Medicine at University of California, Los Angeles (UCLA), Los Angeles, California (United States); Jonsson Comprehensive Cancer Center at UCLA, Los Angeles, California (United States)

    2013-11-01

    Purpose: To explore patterns of Notch receptor and ligand expression in response to radiation that could be crucial in defining optimal dosing schemes for γ-secretase inhibitors if combined with radiation. Methods and Materials: Using MCF-7 and T47D breast cancer cell lines, we used real-time reverse transcription–polymerase chain reaction to study the Notch pathway in response to radiation. Results: We show that Notch receptor and ligand expression during the first 48 hours after irradiation followed a complex radiation dose–dependent pattern and was most pronounced in mammospheres, enriched for breast cancer stem cells. Additionally, radiation activated the Notch pathway. Treatment with a γ-secretase inhibitor prevented radiation-induced Notch family gene expression and led to a significant reduction in the size of the breast cancer stem cell pool. Conclusions: Our results indicate that, if combined with radiation, γ-secretase inhibitors may prevent up-regulation of Notch receptor and ligand family members and thus reduce the number of surviving breast cancer stem cells.

  1. Patient Specification Quality Assurance for Glioblastoma Multiforme Brain Tumors Treated with Intensity Modulated Radiation Therapy

    OpenAIRE

    Al-Mohammed, H. I.

    2011-01-01

    The aim of this study was to evaluate the significance of performing patient specification quality assurance for patients diagnosed with glioblastoma multiforme treated with intensity modulated radiation therapy. The study evaluated ten intensity modulated radiation therapy treatment plans using 10 MV beams, a total dose of 60 Gy (2 Gy/fraction, five fractions a week for a total of six weeks treatment). For the quality assurance protocol we used a two-dimensional ionization-chamber array (2D-...

  2. Radiation related basic cancer research : research for radiation induced tumor cell killing

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Hoon; Hong, Seok Il; Cho, Kyung Ja; Kim, Byung Gi; Lee, Kee Ho; Nam, Myung Jin

    1999-04-01

    The radioresistant clones was established from human U251 glioblastoma cell line through intermittently exposed to 3 Gy gamma-radiation for six months. Treatment of SNU-16 cells with various doses of radiation, TNF alpha and PMA resulted in a decrease in cell viability. The results prove that cell death of SNU16 is a apoptosis mediated by caspase-3. We have examined the expression of bcl-2 and c-myc in cervical cancer specimens and cervical intraepithelial neoplasia (CIN) to determine the role of coexpression of bcl-3 and c-myc during progression into cervical cancer. The frequent alterations in FHIT expression in many cervical carcinomas and their cell lines suggest that FHIT gene alterations are pla a role in cervical tumorigenesis. According to these correlation between the viability and apoptosis of RD cells, the proper range of the dosage for the investigation of differentiation potency in RD cells was assessed as 1 to 3Gy.

  3. Radiation tolerance of boron doped dendritic web silicon solar cells

    Science.gov (United States)

    Rohatgi, A.

    1980-01-01

    The potential of dendritic web silicon for giving radiation hard solar cells is compared with the float zone silicon material. Solar cells with n(+)-p-P(+) structure and approximately 15% (AMl) efficiency were subjected to 1 MeV electron irradiation. Radiation tolerance of web cell efficiency was found to be at least as good as that of the float zone silicon cell. A study of the annealing behavior of radiation-induced defects via deep level transient spectroscopy revealed that E sub v + 0.31 eV defect, attributed to boron-oxygen-vacancy complex, is responsible for the reverse annealing of the irradiated cells in the temperature range of 150 to 350 C.

  4. Radiative efficiency of lead iodide based perovskite solar cells

    Science.gov (United States)

    Tvingstedt, Kristofer; Malinkiewicz, Olga; Baumann, Andreas; Deibel, Carsten; Snaith, Henry J.; Dyakonov, Vladimir; Bolink, Henk J.

    2014-08-01

    The maximum efficiency of any solar cell can be evaluated in terms of its corresponding ability to emit light. We herein determine the important figure of merit of radiative efficiency for Methylammonium Lead Iodide perovskite solar cells and, to put in context, relate it to an organic photovoltaic (OPV) model device. We evaluate the reciprocity relation between electroluminescence and photovoltaic quantum efficiency and conclude that the emission from the perovskite devices is dominated by a sharp band-to-band transition that has a radiative efficiency much higher than that of an average OPV device. As a consequence, the perovskite have the benefit of retaining an open circuit voltage ~0.14 V closer to its radiative limit than the OPV cell. Additionally, and in contrast to OPVs, we show that the photoluminescence of the perovskite solar cell is substantially quenched under short circuit conditions in accordance with how an ideal photovoltaic cell should operate.

  5. Model of cell response to {\\alpha}-particle radiation

    CERN Document Server

    Liu, Longjian

    2012-01-01

    Starting from a general equation for organism (or cell system) growth and attributing additional cell death rate (besides the natural rate) to therapy, we derive an equation for cell response to {\\alpha} radiation. Different from previous models that are based on statistical theory, the present model connects the consequence of radiation with the growth process of a biosystem and each variable or parameter has meaning regarding the cell evolving process. We apply this equation to model the dose response for {\\alpha}-particle radiation. It interprets the results of both high and low linear energy transfer (LET) radiations. When LET is high, the additional death rate is a constant, which implies that the localized cells are damaged immediately and the additional death rate is proportional to the number of cells present. While at low LET, the additional death rate includes a constant term and a linear term of radiation dose, implying that the damage to some cell nuclei has a time accumulating effect. This model ...

  6. Roles of ionizing radiation in cell transformation

    Energy Technology Data Exchange (ETDEWEB)

    Tobias, C.A.; Albright, N.W.; Yang, T.C.

    1983-07-01

    Earlier the authors described a repair misrepair model (RMR-I) which is applicable for radiations of low LET, e.g., x rays and gamma rays. RMR-II was described later. Here is introduced a mathematical modification of the RMR model, RMR-III, which is intended to describe lethal effects caused by heavily ionizing tracks. 31 references, 4 figures.

  7. Solar cell nanotechnology for improved efficiency and radiation hardness

    Science.gov (United States)

    Fedoseyev, Alexander I.; Turowski, Marek; Shao, Qinghui; Balandin, Alexander A.

    2006-08-01

    Space electronic equipment, and NASA future exploration missions in particular, require improvements in solar cell efficiency and radiation hardness. Novel nano-engineered materials and quantum-dot array based photovoltaic devices promise to deliver more efficient, lightweight solar cells and arrays which will be of high value to long term space missions. In this paper, we describe issues related to the development of the quantum-dot based solar cells and comprehensive software tools for simulation of the nanostructure-based photovoltaic cells. Some experimental results used for the model validation are also reviewed. The novel modeling and simulation tools for the quantum-dot-based nanostructures help to better understand and predict behavior of the nano-devices and novel materials in space environment, assess technologies, devices, and materials for new electronic systems as well as to better evaluate the performance and radiation response of the devices at an early design stage. The overall objective is to investigate and design new photovoltaic structures based on quantum dots (QDs) with improved efficiency and radiation hardness. The inherently radiation tolerant quantum dots of variable sizes maximize absorption of different light wavelengths, i.e., create a "multicolor" cell, which improves photovoltaic efficiency and diminishes the radiation-induced degradation. The QD models described here are being integrated into the advanced photonic-electronic device simulator NanoTCAD, which can be useful for the optimization of QD superlattices as well as for the development and exploring of new solar cell designs.

  8. Drying characteristics and quality of bananas under infrared radiation heating

    Science.gov (United States)

    Hot air (HA) drying of banana has low drying efficiency and results in undesirable product quality. The objectives of this research were to investigate the feasibility of infrared (IR) heating to improve banana drying rate, evaluate quality of the dried product, and establish models for predicting d...

  9. Mammalian cells exposed to ionizing radiation: structural and biochemical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Sabanero, M.; Flores V, L. L. [Universidad de Guanajuato, Departamento de Biologia, DCNE, Noria Alta s/n, 36250 Guanajuato, Gto. (Mexico); Azorin V, J. C.; Vallejo, M. A.; Cordova F, T.; Sosa A, M. [Universidad de Guanajuato, Departamento de Ingenieria Fisica, DCI, Loma del Bosque 103, Col. Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Castruita D, J. P. [Universidad de Guadalajara, Departamento de Ecologia, CUCBA, Las Agujas, 45100 Zapopan, Jalisco (Mexico); Barbosa S, G., E-mail: myrna.sabanero@gmail.com [Universidad de Guanajuato, Departamento de Ciencias Medicas, DCS, 20 de Enero No. 929, Col. Obregon, 37000 Leon, Guanajuato (Mexico)

    2015-10-15

    Acute or chronic exposure to ionizing radiation is a factor that may be hazardous to health. It has been reported that exposure to low doses of radiation (less than 50 mSv / year) and subsequently exposure to high doses have greater effects in people. However, it is unknown molecular and biochemical level alteration. This study, analyzes the susceptibility of a biological system (HeLa Atcc CCL-2 human cervix cancer cell line) to ionizing radiation (6 and 60 mSv/ 90). Our evaluate multiple variables such as: total protein profile, mitochondrial metabolic activity (XTT assay), cell viability (Trypan blue exclusion assay), cytoskeleton (actin micro filaments), nuclei (D API), genomic DNA. The results indicate, that cells exposed to ionizing radiation structurally show alterations in nuclear phenotype and aneuploidy, further disruption in the tight junctions and consequently on the distribution of actin micro filaments. Similar alterations were observed in cells treated with a genotoxic agent (200μM H{sub 2}O{sub 2}/1 h). In conclusion, this multi-criteria assessment enables precise comparisons of the effects of radiation between any biological systems. However, it is necessary to determine stress markers for integration of the effects of ionizing radiation. (Author)

  10. Interaction of Ionizing Radiation, Genetically Active Chemicals, and Radiofrequency Radiation in Human and Rodent Cells

    Science.gov (United States)

    1990-12-01

    Martin L. Meltz, Ph.D. Patricia K. Holahan , Ph.D. Steven T. Smith, Ph.D. James J. Kerbacher, Ph.D. Victor Ciaravino, Ph.D. Department of Radiology PO...Chemicals, and Radiofrequency Radiation in Human and Rodent Cells 12 PERSONAL AUTHOR(S) Meltz. Martin L.; Holahan Patricia K.; Smith Steven Kerbacher...Potentiation of SCE Induction and Cell Killing by Adriamycin in CHO Cells (Ciaravino and Holahan , in preparation), showed that Adriamycin exposure at 410C

  11. Cone Penetrometer Load Cell Temperature and Radiation Testing Results

    Energy Technology Data Exchange (ETDEWEB)

    Follett, Jordan R.

    2013-08-28

    This report summarizes testing activities performed at the Pacific Northwest National Laboratory to verify the cone penetrometer load cell can withstand the tank conditions present in 241-AN-101 and 241-AN-106. The tests demonstrated the load cell device will operate under the elevated temperature and radiation levels expected to be encountered during tank farm deployment of the device.

  12. The regulatory effects of radiation and histone deacetylase inhibitor on liver cancer cell cycle

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung Ho; Choi, Hyung Seok; Jang, Dong Gun; Lee, Hong Je; Yang, Seoung Oh [Dept. Nuclear Medicine, Dongnam Institute of Radiological and Medicine Sciences Cancer Center, Busan (Korea, Republic of)

    2013-11-15

    Radiation has been an effective tool for treating cancer for a long time. Radiation therapy induces DNA damage within cancer cells and destroys their ability to reproduce. Radiation therapy is often combined with other treatments, like surgery and chemotherapy. Here, we describe the effects of radiation and histone deacetylase inhibitor, Trichostain A, on cell cycle regulation in hepatoma cells. Results demonstrate that the treatment of radiation TSA induces cell cycle arrest, thereby stimulating cell death in hepatoma cells. In addition, since different cells or tissues have different reactivity to radiation and TSA, these results might be an indicator for the combination therapy with radiation and drugs in diverse cancers.

  13. Image quality and radiation dose in cardiac imaging

    NARCIS (Netherlands)

    Dijk, van Joris David

    2016-01-01

    Coronary artery disease is a major cause of death accounting for 8% of all deaths in the Netherlands. This disease can be detected in an early stage by cardiac imaging. However, this detection comes at the price of a relatively high radiation dose which is potentially harmful for the patient. Despit

  14. Radiation safety and quality in diagnostic x-ray imaging 2001; Saeteilyturvallisuus ja laatu roentgendiagnostiikassa 2001

    Energy Technology Data Exchange (ETDEWEB)

    Servomaa, A.; Parviainen, T. (eds.)

    2001-05-01

    The obligations of the medical exposure directive (97/43/Euratom) for hospitals dominate the current activities in radiation protection in medical radiology. The directive gives special emphasis to radiation exposure of children, to examinations with high radiation doses and to radiation exposure in health screening programmes. The most important examinations with high doses are radiological interventions, where even acute skin effects are possible, and the computed tomography where the number of CT examinations makes only about 5% from the total number of x-ray examinations but the collective effective dose about 40% from the combined collective effective dose of all x-ray examinations. In the research projects financed by the European Commission, radiation exposures to paediatric patients have been measured in radiography, fluoroscopy and CT, and various dose assessment methods have been compared to develop a method for national follow-up of patients' radiation dose. The newest research project is focused on dosimetry and quality assurance in interventional radiology and digital imaging. Other actual topics are the development of radiation protection regulations and quality systems, education and training programmes, and clinical audits. This report deals with new radiation protection guides and recommendations and the education and training of radiological staff in radiation protection. One important topic is the development of national follow-up method of radiation exposure to patients and comparison of various dose assessment methods. Quality assurance in health care and in paediatric radiology, and the acceptance test and quality assurance measurements of radiological equipment are also described. (orig.)

  15. 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.

  16. 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.

  17. Coniferyl Aldehyde Ameliorates Radiation Intestine Injury via Endothelial Cell Survival

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Ye Ji; Jung, Myung Gu; Lee, Yoonjin; Lee, Haejune [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Lee, Yunsil [Ewha Woman' s Univ., Seoul (Korea, Republic of); Ko, Younggyu [Korea Univ., Seoul (Korea, Republic of)

    2014-05-15

    Cancer treatments related gastrointestinal toxicity has also been recognized as a significant economic burden. Especially, extensive apoptosis of microvascular endothelial cell of the lamina propria is the primary lesion initiating intestinal radiation damage after abdominal radiation therapy. Coniferyl aldehyde (CA) is phenolic compounds isolated from cork stoppers, and one of the major pyrolysis products of lignin. Shi H. was support for the empirical use of CA as a medicinal food for cardiovascular diseases. CA has positive effect in broad way but there is no consequence in radiation induced intestine damage. Here, we investigate effect of CA on small intestine after abdominal IR to mice in this study. In this study, CA increased the survival rate in C3H mice against 13.5 Gy abdominal IR. We found CA protects small intestine via preventing endothelial cell apoptosis and enhancing their angiogenic activity. CA also showed protective effect on crypt cell survival. Endothelial cell survival may affect crypt cell protection against IR. From this data, we concluded that CA is effective for protection against abdominal radiation injury. CA could ameliorate side-effect of radiation therapy.

  18. Proton irradiation of stem cells: Radiation damage and chemical radioprotection

    Science.gov (United States)

    Riley, R. C.; Montour, J. L.; Gurney, C. W.

    1972-01-01

    Effects of high energy protons on erythropoietic stem cells and radioprotection by chemicals were investigated in NASA Space Radiation Effects Laboratory. The effects of a parallel beam of 600 MeV protons. The fluence, when converted to dose, were referenced to the synchrocyclotron beam monitors which were then used to administer radiation exposures. Mice were given graded doses to 300 rads to determine dose-response curve. Other mice received saline, AET, or 5-hydroxytryptamine 10 to 15 minutes before exposure.

  19. Development of materials for fuel cell application by radiation technology

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, Chang Kyu; Lee, Min Ku; Park, Junju; Lee, Gyoungja; Lee, Byung Cheol; Shin, Junhwa; Nho, Youngchang; Kang, Philhyun; Sohn, Joon Yong; Rang, Uhm Young

    2012-06-15

    The development of the single cell of SOFC with low operation temperature at and below 650 .deg. C(above 400 mW/cm{sup 2}) Ο The development of fabrication method for the single cell of solid oxide fuel cell (SOFC) by dip-coating of nanoparticles such as NiO, YSZ, Ag, and Ag/C, etc. Ο The optimization of the preparation and performance of SOFC by using nanoparticles. Ο The preparation of samples for SOFC with large dimension. The development of fluoropolymer-based fuel cell membranes with crosslinked structure by radiation grafting technique Ο The development of fuel cell membranes with low methanol permeability via the introduction of novel monomers (e. g. vinylbenzyl chloride and vinylether chloride) by radiation grafting technique Ο The development of hydrocarbon fuel cell membrane by radiation crosslinking technique Ο The structure analysis and the evaluations of the property, performance, and radiation effect of the prepared membranes Ο The optimization of the preparation and performance of DMFC fuel cell membrane via the structure-property analysis (power: above 130 mW/cm{sup 2}/50 cm{sup 2} at 5M methanol) Ο The preparation of samples for MEA stack assembly.

  20. Influence on cell proliferation of background radiation or exposure to very low, chronic gamma radiation. [Paramecium tetraurelia; Synechococcus lividus

    Energy Technology Data Exchange (ETDEWEB)

    Planel, H.; Soleilhavoup, J.P.; Tixador, R.; Richoilley, G.; Conter, A.; Croute, F.; Caratero, C.; Gaubin, Y.

    1987-05-01

    Investigations carried out on the protozoan Paramecium tetraurelia and the cyanobacteria Synechococcus lividus, which were shielded against background radiation or exposed to very low doses of gamma radiation, demonstrated that radiation can stimulate the proliferation of these two single-cell organisms. Radiation hormesis depends on internal factors (age of starting cells) and external factors (lighting conditions). The stimulatory effect occurred only in a limited range of doses and disappeared for dose rates higher than 50 mGy/y.

  1. Ionizing radiation and mitogenetic radiation: two links of the same energetic chain in a biological cell.

    Science.gov (United States)

    Goraczko, W

    2000-03-01

    Present research demonstrates that the excitation of living systems by high energy/low doses of ionizing radiation (IR) initiates prolonged secondary ultraviolet (UV) range emission that influences biota. When doses of this energy are too high, the process of energy or radiation absorption by the cells causes negative changes (i.e. negative mutations or death). When these doses are sufficiently low, vital processes inside the cells are stimulated and can create positive changes. This paper proposes a common denomination for mechanisms of UV and ionizing radiation when interacting with living cells, underlying both its mitogenetic effect and radiation hormesis. Data from radon exposure in chronically exposed nuclear workers, acutely exposed Hiroshima and Nagasaki victims and observers of atmospheric nuclear explosions, combined with animal results, present irrefutable evidence that low doses of IR are beneficial. As a conclusion the author postulates the possibility of new methods of therapy regarding the use of IR and mitogenetic radiation. This paper has been written to encourage debate regarding possible future benefits that may be derived from low level doses of IR exposure in the general population.

  2. In vitro cell culture lethal dose submitted to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Carolina S.; Rogero, Sizue O.; Rogero, Jose Roberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: carolina_sm@hotmail.com; Ikeda, Tamiko I.; Cruz, Aurea S. [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil)

    2009-07-01

    The present study was designed to evaluate the in vitro effect of gamma radiation in cell culture of mouse connective tissue exposed to different doses of gamma radiation and under several conditions. The cell viability was analyzed by neutral red uptake methodology. This assay was developed for establish a methodology to be used in the future in the study of resveratrol radioprotection. Resveratrol (3,4',5- trihydroxystilbene), a phenolic phytoalexin that occurs naturally in some spermatophytes, such as grapevines, in response to injury as fungal infections and exposure to ultraviolet light. In the wines this compound is found at high levels and is considered one of the highest antioxidant constituents. The intense antioxidant potential of resveratrol provides many pharmacological activities including cardioprotection, chemoprevention and anti-tumor effects. Our results demonstrated that {sup 60}Co gamma radiation lethal dose (LD50) on NCTC clone 929 cells was about 340Gy. (author)

  3. Distribution of Chromosome Breakpoints in Human Epithelial Cells Exposed to Low- and High-LET Radiations

    Science.gov (United States)

    Hada, Megumi; Cucinotta, Francis; Wu, Honglu

    2009-01-01

    The advantage of the multicolor banding in situ hybridization (mBAND) technique is not only its ability to identify simultaneously both inter- and intrachromosome exchanges, but also the ability to measure the breakpoint location along the length of the chromosome in a precision that is unmatched with other traditional banding techniques. Breakpoints on specific regions of a chromosome have been known to associate with specific cancers. The breakpoint distribution in cells after low- and high-LET radiation exposures will also provide the data for biophysical modeling of the chromatin structure, as well as the data for the modeling the formation of radiation-induced chromosome aberrations. In a series of experiments, we studied low- and high-LET radiation-induced chromosome aberrations using the mBAND technique with chromosome 3 painted in 23 different colored bands. Human epithelial cells (CH1 84B5F5/M10) were exposed in vitro to Cs- 137 rays at both low and high dose rates, secondary neutrons with a broad energy spectrum at a low dose rate and 600 MeV/u Fe ions at a high dose rate. The data of both inter- and intrachromosome aberrations involving the painted chromosome have been reported previously. Here we present data of the location of the chromosome breaks along the length of chromosome 3 in the cells after exposures to each of the four radiation scenarios. In comparison to the expected breakpoint distribution based on the length of the bands, the observed distribution appeared to be non-random for both the low- and high-LET radiations. In particular, hot spots towards both ends of the chromosome were found after low-LET irradiations of either low or high dose rates. For both high-LET radiation types (Fe ions and neutrons), the breakpoint distributions were similar, and were much smoother than that for low-LET radiation. The dependence of the breakpoint distribution on the radiation quality requires further investigations.

  4. Effect of Deep Space Radiation on Human Hematopoietic Cells

    Science.gov (United States)

    Kalota, Anna; Bennett, Paula; Swider, Cezary R.; Sutherland, Betsy M.; Gewirtz, Alan M.

    Astronaut flight crews on long-term missions in deep space will be exposed to a unique radiation environment as a result of exposure to galactic cosmic rays (GCR) and solar particle events (SPE). This environment consists predominantly of high energy protons, helium and high charge, high energy (HZE) atomic nuclei from iron predominantly, but all other elements as well. The effect of such particles, alone, or in combination, on human hematopoietic stem and progenitor cells (HSPC) has not been well studied but is clearly of interest since blood forming cells are known to be sensitive to radiation, and irreversible damage to these cells could quickly compromise a mission due to loss of marrow function. To better understand the effects of GCR and SPE on human stem/progenitor cell function, we have exposed partially purified CD34+ normal human marrow cells to protons, radioactive Fe, and Ti, alone, and in combination at varying doses up to 70cGy, and down to 1, 2, and 4 particle hits per nucleus. We then examined the effects of these radiations on HSPC function, as assessed by the ability to form CFU-GEMM, and LTCIC colonies in semi-solid culture medium. At the highest doses (50 and 70cGy), all radiation types tested significantly diminished the ability of CD34+ cells to form such colonies. The number of CFU-GEMM in irradiated samples was 70-90

  5. Effect of radiofrequency radiation in cultured mammalian cells: A review.

    Science.gov (United States)

    Manna, Debashri; Ghosh, Rita

    2016-01-01

    The use of mobile phone related technologies will continue to increase in the foreseeable future worldwide. This has drawn attention to the probable interaction of radiofrequency electromagnetic radiation with different biological targets. Studies have been conducted on various organisms to evaluate the alleged ill-effect on health. We have therefore attempted to review those work limited to in vitro cultured cells where irradiation conditions were well controlled. Different investigators have studied varied endpoints like DNA damage, cell cycle arrest, reactive oxygen species (ROS) formation, cellular morphology and viability to weigh the genotoxic effect of such radiation by utilizing different frequencies and dose rates under various irradiation conditions that include continuous or pulsed exposures and also amplitude- or frequency-modulated waves. Cells adapt to change in their intra and extracellular environment from different chemical and physical stimuli through organized alterations in gene or protein expression that result in the induction of stress responses. Many studies have focused on such effects for risk estimations. Though the effects of microwave radiation on cells are often not pronounced, some investigators have therefore combined radiofrequency radiation with other physical or chemical agents to observe whether the effects of such agents were augmented or not. Such reports in cultured cellular systems have also included in this review. The findings from different workers have revealed that, effects were dependent on cell type and the endpoint selection. However, contradictory findings were also observed in same cell types with same assay, in such cases the specific absorption rate (SAR) values were significant.

  6. Materials That Enhance Efficiency and Radiation Resistance of Solar Cells

    Science.gov (United States)

    Sun, Xiadong; Wang, Haorong

    2012-01-01

    A thin layer (approximately 10 microns) of a novel "transparent" fluorescent material is applied to existing solar cells or modules to effectively block and convert UV light, or other lower solar response waveband of solar radiation, to visible or IR light that can be more efficiently used by solar cells for additional photocurrent. Meanwhile, the layer of fluorescent coating material remains fully "transparent" to the visible and IR waveband of solar radiation, resulting in a net gain of solar cell efficiency. This innovation alters the effective solar spectral power distribution to which an existing cell gets exposed, and matches the maximum photovoltaic (PV) response of existing cells. By shifting a low PV response waveband (e.g., UV) of solar radiation to a high PV response waveband (e.g. Vis-Near IR) with novel fluorescent materials that are transparent to other solar-cell sensitive wavebands, electrical output from solar cells will be enhanced. This approach enhances the efficiency of solar cells by converting UV and high-energy particles in space that would otherwise be wasted to visible/IR light. This innovation is a generic technique that can be readily implemented to significantly increase efficiencies of both space and terrestrial solar cells, without incurring much cost, thus bringing a broad base of economical, social, and environmental benefits. The key to this approach is that the "fluorescent" material must be very efficient, and cannot block or attenuate the "desirable" and unconverted" waveband of solar radiation (e.g. Vis-NIR) from reaching the cells. Some nano-phosphors and novel organometallic complex materials have been identified that enhance the energy efficiency on some state-of-the-art commercial silicon and thin-film-based solar cells by over 6%.

  7. Radiation protection of patients and quality controls in teleradiology

    Energy Technology Data Exchange (ETDEWEB)

    Vermiglio, G.; Testagrossa, B.; Sansotta, C.; Tripepi, M.G. [Messina Univ., Dept. of Protezionistica Ambientale, Sanitaria, Sociale ed Industriale (Italy)

    2006-07-01

    Nowadays, it is well-known that tele-radiology represents the new frontier of radiodiagnostic imaging. In this case, the continuous broadening of transmission bands and the more sophisticated procedures of information packaging constitute a no negligible inducement. Moreover, standards used to convert analogical signals into the digital ones, necessary to transfer via ether radiological images and information, involve a more limited loss of information. Nevertheless, unlike the common images, in case of the X-ray diagnostic images it must take into account that the EURATOM Council Directives give the health physicist all the procedures to be followed for checking the status of X-ray equipments. In particular, the EURATOM Council Directives provide minimum criteria of acceptance for parameters that characterised the correct working of the radiological equipments and the guide lines for standardised execution of X-ray images, in order to obtain high quality information. In addiction, for maintaining such level it is necessary to adopt adequate programs of Quality Assurance. Naturally, the high quality of radiological images must be conserved after the transmission of information. So, in order to evaluate the amount of losses that can be introduced after transferring the X-ray images from source to user, the authors have carried out specific procedures in order to evaluate the quality level of the images after transmission and to compare them with the correspondent ones acquired at the equipment console. To this aim, the AAs have identified all the parameters able to verify the quality level of the images and measured the values obtained for the directly acquired images and the transferred ones. They have also considered different kinds of transmission protocols to define suitable procedures of remote quality controls. (authors)

  8. [Gamma-radiation action on cells of algae Euglena gracilis].

    Science.gov (United States)

    Glinkova, E; Zhuchkina, N I; Koltovoĭ, N A; Koltovaia, N A

    2012-01-01

    Considering the potentials of algae Euglena to constitute a part of biological systems of human life support, effects of low radiation doses on algal cells and radiosensitivity dependence on their genotype were studied. In experiments with gamma-irradiation (60Co) of Euglena gracilis, the highest radioresistance was demonstrated by strain Z. OFL; the chloroplasts lacking Z-derived strain showed hypersensitivity to radiation. E. bacillaris and derived chlorophyll-lacking strains W3 and W10 had intermediate radiosensitivity. Irradiation with the doses of up to 10 Gy produced a hormetic effect in the stock strains. Cells death was observed only after irradiation by doses above 100 Gy. The stimulating effect was exerted both on radioresistance and growth rate. Dyes made possible rapid evaluation of the proportion of living and dead cells. Comparison of two survival tests showed that the classic medium inoculation overestimates cell deaths as it disregards the living non-proliferating cells.

  9. Neoplastic cell transformation by high-LET radiation - Molecular mechanisms

    Science.gov (United States)

    Yang, Tracy Chui-Hsu; Craise, Laurie M.; Tobias, Cornelius A.; Mei, Man-Tong

    1989-01-01

    Quantitative data were collected on dose-response curves of cultured mouse-embryo cells (C3H10T1/2) irradiated with heavy ions of various charges and energies. Results suggests that two breaks formed on DNA within 80 A may cause cell transformation and that two DNA breaks formed within 20 A may be lethal. From results of experiments with restriction enzymes which produce DNA damages at specific sites, it was found that DNA double strand breaks are important primary lesions for radiogenic cell transformation and that blunt-ended double-strand breaks can form lethal as well as transformational damages due to misrepair or incomplete repair in the cell. The RBE-LET relationship for high-LET radiation is similar to that for HGPRT locus mutation, chromosomal deletion, and cell transformation, indicating that common lesions may be involved in these radiation effects.

  10. Combination Effect of Nimotuzumab with Radiation in Colorectal Cancer Cells

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hye Kyung; Kim, Mi Sook; Jeong, Jae Hoon [Korea Institute of Radiologicaland Medical Sciences, Seoul (Korea, Republic of)

    2010-11-15

    To investigate the radiosensitizing effect of the selective epidermal growth factor receptor (EGFR) inhibitor nimotuzumab in human colorectal cancer cell lines. Four human colorectal cancer cell lines, HCT-8, LoVo, WiDr, and HCT-116 were treated with nimotuzumab and/or radiation. The effects on cell proliferation, viability, and cell cycle progression were measured by MTT, clonogenic survival assay, flow cytometry, and Western blot. An immunoblot analysis revealed that EGFR phosphorylation was inhibited by nimotuzumab in colorectal cancer cell lines. Under these experimental conditions, pre-treatment with nimotuzumab increased radiosensitivity of colorectal cancer cell lines, except for cell line HCT-116. However, cell proliferation or cell cycle progression was not affected by the addition of nimotuzumab, irrespective of irradiation. Nimotuzumab enhanced the radiosensitivity of colorectal cancer cells in vitro by inhibiting EGFR-mediated cell survival signaling. This study provided a rationale for the clinical application of the selective EGFR inhibitor, nimotuzumab in combination with radiation in colorectal cancer cells.

  11. Accounting for radiation quality in heavy ion therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kellerer, A.M. [LMU, Muenchen (Germany). Radiobiological Inst.]|[Gesellschaft fuer Strahlen- und Umweltforschung, Muenchen (Germany). Inst. fuer Nuklearbiologie

    1997-09-01

    This introductory contribution outlines the need for models and their use in radiotherapy dose planning. The linear-quadratic dose relation is now predominantly used in therapy dose planning. In Section I it is linked to the earlier quantitative scheme for conventional radiotherapy. In Section II two major approaches are presented in a form that makes them comparable; the section can be read by itself, if this comparison alone is of interest. Models for therapy planning are tools, largely of empirical character; they do not need to elucidate unknown mechanisms of radiation action. The emphasis is, therefore, on the computational scheme, not on its interpretation. (orig.)

  12. Reducing radiation to patients and improving image quality in a real-world nuclear cardiology laboratory.

    Science.gov (United States)

    Bloom, Stephen A; Meyers, Karen

    2017-03-22

    In part because of aging equipment and reduced reimbursement for imaging services in the last several years, nuclear cardiologists who remain in private practice face challenges in maintaining high quality and in reducing radiation exposure to patients. We review patient-centered approaches and affordable software solutions employed in our practice combined with supine-prone myocardial perfusion imaging to achieve increased interpretive confidence with reduced radiation exposure to patients.

  13. Dosimetric systems developed in Brazil for the radiation processes quality control

    Energy Technology Data Exchange (ETDEWEB)

    Galante, Ana Maria Sisti; Campos, Leticia Lucente, E-mail: sgalante@ipen.b, E-mail: lcrodri@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    In order to apply new technologies to the industrial processing of materials aiming economy, efficiency, speed and high quality, ionizing radiation has been used in medicine, archaeology, chemistry, food preservation and other areas. For this reason, the dosimetry area looks for improve current dosimeters and develop new materials for application on quality control of these processes. In Brazil, the research in the dosimetry area occurs with great speed providing many different dosimetric systems. The chemical dosimetry is the most used technique in routine dosimetry, which requires fast and accurate responses. This technique involves determination of absorbed dose by measuring chemical changes radiation induced in the materials. Different dosimetric systems were developed at IPEN for application on radiation process quality and all of them present excellent results; the low cost of these materials allows a more effective dose control, therefore, a larger area or volume can be monitored. (author).

  14. Ionizing radiation treatment to improve postharvest life and maintain quality of fresh guava fruit

    Science.gov (United States)

    Singh, S. P.; Pal, R. K.

    2009-02-01

    We investigated the potential of ionizing radiation for improving physiological responses, quality, and storage time of fresh guava fruit. Ionizing radiation treatment suppressed the respiration and ethylene production rates and thus retarded the process of fruit ripening during storage. Irradiation treatment also retarded the physical and biochemical changes associated with ripening such as firmness, titratable acidity, soluble solids content, and vitamin C during storage, but for doses higher than 0.25 kGy the vitamin C content decreased. The positive effects of ionizing radiation treatment on delayed fruit ripening and other quality attributes diminished during 22 days of storage at 10 °C. Thus, a combination of ionizing radiation with low-temperature storage (10 °C) did not have much synergistic effect on storage life and quality of guava fruit. In conclusion, ionizing radiation treatment of guava fruit with 0.25 kGy dose increased the postharvest life by 3-4 days, maintained fruit quality, and reduced the decay incidence. The optimal dose (0.25 kGy) for postharvest life extension of guava fruit may be exploited to provide phytosanitary security against many insect pests including fruit flies.

  15. Ionizing radiation treatment to improve postharvest life and maintain quality of fresh guava fruit

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.P. [Handling and Storage Laboratory, Division of Postharvest Technology, Indian Agricultural Research Institute (IARI), Pusa, New Delhi 110 012 (India)], E-mail: sukhvinder.singh@curtin.edu.au; Pal, R.K. [Handling and Storage Laboratory, Division of Postharvest Technology, Indian Agricultural Research Institute (IARI), Pusa, New Delhi 110 012 (India)

    2009-02-15

    We investigated the potential of ionizing radiation for improving physiological responses, quality, and storage time of fresh guava fruit. Ionizing radiation treatment suppressed the respiration and ethylene production rates and thus retarded the process of fruit ripening during storage. Irradiation treatment also retarded the physical and biochemical changes associated with ripening such as firmness, titratable acidity, soluble solids content, and vitamin C during storage, but for doses higher than 0.25 kGy the vitamin C content decreased. The positive effects of ionizing radiation treatment on delayed fruit ripening and other quality attributes diminished during 22 days of storage at 10 deg. C. Thus, a combination of ionizing radiation with low-temperature storage (10 deg. C) did not have much synergistic effect on storage life and quality of guava fruit. In conclusion, ionizing radiation treatment of guava fruit with 0.25 kGy dose increased the postharvest life by 3-4 days, maintained fruit quality, and reduced the decay incidence. The optimal dose (0.25 kGy) for postharvest life extension of guava fruit may be exploited to provide phytosanitary security against many insect pests including fruit flies.

  16. Radiation exposure and image quality in x-Ray diagnostic radiology physical principles and clinical applications

    CERN Document Server

    Aichinger, Horst; Joite-Barfuß, Sigrid; Säbel, Manfred

    2012-01-01

    The largest contribution to radiation exposure to the population as a whole arises from diagnostic X-rays. Protecting the patient from radiation is a major aim of modern health policy, and an understanding of the relationship between radiation dose and image quality is of pivotal importance in optimising medical diagnostic radiology. In this volume the data provided for exploring these concerns are partly based on X-ray spectra, measured on diagnostic X-ray tube assemblies, and are supplemented by the results of measurements on phantoms and simulation calculations.

  17. A framework for quality improvement and patient safety education in radiation oncology residency programs.

    Science.gov (United States)

    Yeung, Anamaria; Greenwalt, Julie

    2015-01-01

    In training future radiation oncologists, we must begin to focus on training future QI specialists. Our patients are demanding better quality and safer care, and accrediting bodies are requiring it. We must equip radiation oncology trainees to be leaders in this new world. To that end, a QI/PS educational program should contain 2 components: a didactic portion focused on teaching basic QI tools as well as an overview of the quality and safety goals of the institution, and an experiential component, ideally a resident-led QI project mentored by an expert faculty member and that is linked to the department's and institution's goals.

  18. Clinical characteristics and changes in living quality of patients with radiation encephalopathy induced by radiation therapy for treating nasopharyngeal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Yamei Tang; Yi Li; Fusheng Zhang; Yunlin Liu; Haihong Zhou; Jianhong Ye; Yigang Xing

    2007-01-01

    BACKGROUND: Radiation encephalopathy (RE) caused by radiation therapy of nasopharyngeal carcinoma severely influences patients' quality of life (QOL). The factors, which influence such patients' QOL, have not been confirmed.OBJECTIVE: To observe the clinical and imageological characteristics of patients with radiation therapy of nasopharyngeal carcinoma-induced RE and the changes in QOL, and analyze QOL influencing factors.DESIGN: Retrospective case analysis.SETTING: Department of Neurology, the Second Affiliated Hospital of Sun Yat-sen University.PARTICIPANTS: Eighty-nine inpatients or outpatients with RE induced by radiation therapy of nasopharyngeal carcinoma admitted to Sun Yat-sen University Cancer Center and Department of Neurology,the Second Affiliated Hospital of Sun Yat-sen University from March 1994 to August 2004 were involved in this experiment. They all met the diagnosis criteria of RE from MERRITT'S neurology (10th edition).Thirty-three involved patients were randomly chosen as RE group. Another 34 concurrent inpatients or outpatients with nasopharyngeal carcinoma who received radiation therapy but without RE were chosen as control group. Informed consents of detected items were obtained from all the involved subjects.Quality of Life Questionnaire abbreviated version (WHOQOL-BREF) was used for on-the-spot evaluation.High points of WHOQOL-BREF indicated better QOL. The Late Effects on Normal Tissues - Subjective,Objective, Management and Analytic (LENT-SOMA) scale for evaluating radiation injury was used to evaluate headache and neurologic disorder of patients with RE induced by radiation therapy of nasopharyngeal carcinoma. The evaluation was graded into 5 degrees. High degrees indicted severer clinical therapy ending to onset), initial symptoms, common symptoms, imageological characteristics, QOL and other software.MAIN OUTCOME MEASURES: QOL and clinical characteristics of patients with RE induced by radiation therapy of nasopharyngeal carcinoma as

  19. Psychology and quality of life in cancer patients on radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jong Chul; Chung, Woong Ki [Chonnam National University Hospital, Gwangju (Korea, Republic of)

    2004-12-15

    The object of this study is to investigate sociodemographic and clinical characteristics, psychology, self-esteem and quality of life in cancer patients on radiation therapy and to provide useful information for therapeutic approach to cancer patients on radiation therapy. The subjects were 36 patients who had been treated with radiation therapy and 20 normal people. Sociodemographic information and clinical characteristics of cancer patients on radiation therapy were investigated, and symptom checklist-90-revised, Rosenberg Self-esteem Scale for self esteem, World Health Organization Quality of Life Assessment Instrument for quality of life were administered to subjects. And Spearman's correlation analysis was used among these. The tendency of somatization, depression, anxiety and hostility in cancer group were significantly higher than normal group. Self esteem and quality of life in cancer group were significantly lower than normal group. No significant difference was found in comparison of psychology, self esteem and quality of life according to sociodemographic variables. Among clinical characteristics, in the presence of metastasis in cancer patients, the scores of anxiety, phobia and paranoid ideation were higher. In patients with pain, the score of somatization was higher. And in case of weight loss, the score of somatization was higher. The higher score of depression, anxiety and hostility were significantly associated with lower self-esteem. And higher score of somatization, depression, anxiety and hostility were significantly associated with lower quality of life. Understanding and management of psychological symptoms, such as somatization, depression, anxiety, and hostility, and pain control are necessary to improve quality of life in cancer patients on radiation therapy.

  20. NASA's high efficiency and radiation damage solar cell program

    Science.gov (United States)

    Randolph, L. P.

    1980-01-01

    The conversion efficiency and the life expectancy of solar cells and arrays were evaluated for space applications. Efforts were made to improve the understanding of the conversion of electromagnetic radiation to useful forms of energy. A broad range of advanced concepts were evaluated.

  1. TH-E-19A-01: Quality and Safety in Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Ford, E [University of Washington, Seattle, WA (United States); Ezzell, G [Mayo Clinic Arizona, Phoenix, AZ (United States); Miller, B [Henry Ford Health System, Clinton Township, MI (United States); Yorke, E [Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    2014-06-15

    Clinical radiotherapy data clearly demonstrate the link between the quality and safety of radiation treatments and the outcome for patients. The medical physicist plays an essential role in this process. To ensure the highest quality treatments, the medical physicist must understand and employ modern quality improvement techniques. This extends well beyond the duties traditionally associated with prescriptive QA measures. This session will review the current best practices for improving quality and safety in radiation therapy. General elements of quality management will be reviewed including: what makes a good quality management structure, the use of prospective risk analysis such as FMEA, and the use of incident learning. All of these practices are recommended in society-level documents and are incorporated into the new Practice Accreditation program developed by ASTRO. To be effective, however, these techniques must be practical in a resource-limited environment. This session will therefore focus on practical tools such as the newly-released radiation oncology incident learning system, RO-ILS, supported by AAPM and ASTRO. With these general constructs in mind, a case study will be presented of quality management in an SBRT service. An example FMEA risk assessment will be presented along with incident learning examples including root cause analysis. As the physicist's role as “quality officer” continues to evolve it will be essential to understand and employ the most effective techniques for quality improvement. This session will provide a concrete overview of the fundamentals in quality and safety. Learning Objectives: Recognize the essential elements of a good quality management system in radiotherapy. Understand the value of incident learning and the AAPM/ASTRO ROILS incident learning system. Appreciate failure mode and effects analysis as a risk assessment tool and its use in resource-limited environments. Understand the fundamental principles of good

  2. Radiation induction of multiaberrant cells in Allium cepa L.

    Energy Technology Data Exchange (ETDEWEB)

    Kutsokon, N.K.; Rashydov, N.M.; Grodzinsky, D.M.

    2008-07-01

    'Rogue' cells determined by human geneticists as the cells with many chromosome aberrations. The main enigma of this phenomenon is its levels are unexpected higher in many studies. Frequently, these cells emergence in human are linked with radiation or viruses. 'Rogue' cells supposed to be very important in mutagenesis, oncogenesis and even in evolution process. We use plant assay (Allium cepa L.) to analyze the induction of cells with many chromosome aberration of different types. Cytogenetic damage of gamma-irradiation as frequency of multiaberrant cells in the root tip cells of Allium was determined. The empiric numbers of cells with many aberrations were compared with those expected in theoretical distributions (Poisson, geometric and Pascal). The frequency of multiaberrant cells in root tip cells was increased up to 83,33 +- 10,76 % under gamma-irradiation in various doses. Gamma-irradiation induced more multiaberrant cells in A. cepa meristems than expected in theoretical distributions. We supposed dependency of chromosome aberrations origin in the same cell after irradiation. The data obtained elucidate that under gamma-irradiation accumulation of aberrations in aberrant cells are not random, the appearance of one aberration in cell induced the appearance of others in the same cell. (author)

  3. Stored electromagnetic energy and quality factor of radiating structures

    Science.gov (United States)

    Capek, Miloslav; Jelinek, Lukas; Vandenbosch, Guy A. E.

    2016-04-01

    This paper deals with the old yet unsolved problem of defining and evaluating the stored electromagnetic energy-a quantity essential for calculating the quality factor, which reflects the intrinsic bandwidth of the considered electromagnetic system. A novel paradigm is proposed to determine the stored energy in the time domain leading to the method, which exhibits positive semi-definiteness and coordinate independence, i.e. two key properties actually not met by the contemporary approaches. The proposed technique is compared with an up-to-date frequency domain method that is extensively used in practice. Both concepts are discussed and compared on the basis of examples of varying complexity.

  4. Workshop on measurement quality assurance for ionizing radiation: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Heath, J.A.; Swinth, K.L. [comps.

    1993-12-31

    This workshop was held to review the status of secondary level calibration accreditation programs, review related measurement accreditation programs, document lessons learned, and to present changes in programs due to new national priorities involving radioactivity measurements. Contents include: fundamentals of measurement quality assurance (MQA), standards for MQA programs; perspectives and policies; complete MQA programs; future MQA programs; QA/QC programs--radioactivity; QA/QC programs--dosimetry; laboratory procedures for QA/QC; in-house control of reference dosimetry laboratories; in-house controls of radioactivity laboratories; and poster session. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  5. Towards microbiological quality assurance in radiation sterilization processing: simulation of the radiation inactivation process

    Energy Technology Data Exchange (ETDEWEB)

    Fitch, F.R.; Dwyer, J. (Manchester Univ. (UK). Inst. of Science and Technology); Doolan, P.T. (Becton Dickinson and Co., Parasmus, NJ (USA)); Dwyer, V.M. (York Univ. (UK). Dept. of Physics); Halls, N.A. (Becton Dickinson and Co., Dun Laoghaire (Ireland)); Tallentire, A. (Manchester Univ. (UK). Dept. of Pharmacy)

    1985-03-01

    A method is developed for computer simulation of the inactivation of microorganisms on items by irradiation. It is shown that in a population of items subjected to increasing doses of radiation the proportion contaminated approaches the appropriate Limiting Case, outlined in a previous paper, as numbers of organisms are decreased by inactivation. The behaviour of populations of items having different proportions of 'spikes' (high bioburden levels) is considered.

  6. Quality keeping and upgrading technique on delivery of raw fodder and so forth by using radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Ryoei; Tanaka, Osamu; Uegaki, Ryuichi; Ando, Sada; Akiyama, Fumiaki; Yamada, Akio [National Grassland Research Inst., Nishinasuno, Tochigi (Japan)

    1998-02-01

    As most of aerobic bacteria, anaerobic spore bacteria, molds and yeasts died owing to 8 to 16 kGy of {gamma}-ray irradiation, it was found that butyric acid fermentation and aerobic putrefaction in silage did not form. As the lactobacilli bringing good fermentation quality died as well at such radiation dose, on a case of a mixed silage using the dregs, in which lactic acid was present, quality of its fermentation was good. And, many informations on changes in fatty quality and yeast activity in the silage formed by irradiation could also be obtained. As the dregs had a large difference in physical and chemical components, quality after preparation of the silage was not uniform. Materials suitable for {gamma}-ray irradiation and radiation dose suitable for each material was found to be clarified. (G.K.)

  7. Classical radiation reaction in particle-in-cell simulations

    Science.gov (United States)

    Vranic, M.; Martins, J. L.; Fonseca, R. A.; Silva, L. O.

    2016-07-01

    Under the presence of ultra high intensity lasers or other intense electromagnetic fields the motion of particles in the ultrarelativistic regime can be severely affected by radiation reaction. The standard particle-in-cell (PIC) algorithms do not include radiation reaction effects. Even though this is a well known mechanism, there is not yet a definite algorithm nor a standard technique to include radiation reaction in PIC codes. We have compared several models for the calculation of the radiation reaction force, with the goal of implementing an algorithm for classical radiation reaction in the Osiris framework, a state-of-the-art PIC code. The results of the different models are compared with standard analytical results, and the relevance/advantages of each model are discussed. Numerical issues relevant to PIC codes such as resolution requirements, application of radiation reaction to macro particles and computational cost are also addressed. For parameters of interest where the classical description of the electron motion is applicable, all the models considered are shown to give comparable results. The Landau and Lifshitz reduced model is chosen for implementation as one of the candidates with the minimal overhead and no additional memory requirements.

  8. On the potential impact of the newly proposed quality factors on space radiation protection

    Science.gov (United States)

    Wilson, John W.; Townsend, Lawrence W.; Cucinotta, Francis A.

    1987-01-01

    The recently proposed changes in the defined quality factor hold great potential for easing some of the protection requirements from electrons and protons in the near-Earth environment. At the same time, the high Linear Energy Transfer (LET) components play an even more important role which must be further evaluated. Several recommendations are made which need to be addressed before these new quality factors can be implemented into space radiation potection practice.

  9. Thalidomide effect in endothelial cell of acute radiation proctitis

    Institute of Scientific and Technical Information of China (English)

    Ki-Tae Kim; Hiun-Suk Chae; Jin-Soo Kim; Hyung-Keun Kim; Young-Seok Cho; Whang Choi; Kyu-Yong Choi; Sang-Young Rho; Suk-Jin Kang

    2008-01-01

    AIM: To determine whether thalidomide prevents microvascular injury in acute radiation proctitis in white rats. METHODS: Fourteen female Wistar rats were used:six in the radiation group,six in the thalidomide group,and two in normal controls.The radiation and thalidomide groups were irradiated at the pelvic area using a single 30 Gy exposure.The thalidomide (150 mg/kg) was injected into the peritoneum for 7 d from the day of irradiation.All animals were sacrificed and the rectums were removed on day 8 after irradiation.The microvessels of resected specimens were immunohistochemically stained with thrombomodulin (TM),yon Willebrand Factor (vWF),and vascular endothelial growth factor (VEGF).RESULTS: The microscopic scores did not differ significantly between the radiation and thalidomide groups,but both were higher than in the control group.Expression of TM was significantly lower in the endothelial cells (EC) of the radiation group than in the control and thalidomide groups (P < 0.001).The number of capillaries expressing vWF in the EC was higher in the radiation group (15.3 ± 6.8) than in the control group (3.7 ± 1.7),and the number of capillaries expressing vWF was attenuated by thalidomide (10.8 ± 3.5,P < 0.001).The intensity of VEGF expression in capillaries was greater in the radiation group than in the control group and was also attenuated by thalidomide (P = 0.003).CONCLUSION: The mechanisms of acute radiationinduced proctitis in the rats are related to endothelial cell injury of microvessel,which may be attenuated with thalidomide.

  10. Phototherapy appliances, their ultraviolet radiation and quality assurance of phototherapy; Terveydenhuollon laadunhallinta. Valohoitolaitteet, niiden UV- saeteily ja valohoitojen laadunvarmistus

    Energy Technology Data Exchange (ETDEWEB)

    Huurto, L.; Leszczynski, K.; Visuri, R.; Ylianttila, L.; Jokela, K. [Radiation and Nuclear Safety Authority, Helsinki (Finland)

    1998-12-31

    Artificial UV radiation (UVR) is used in the treatment of psoriasis and other skin diseases. Long term phototherapy is associated to increased risk of squamous cell carcinoma. This report gives a short review of biological effects of UVR and technical aspects of phototherapy units. The phototherapy units used in Finnish Central hospitals are described and the measured UVR dose rates of these units are presented. In addition, the UVR meters used in hospitals are described and the calibration factors are given for UVR dose rate measurements: Finally, recommendations are given for the quality assurance of photo-therapy units as well as for assessing UVR doses of patients. (orig.) 88 refs.

  11. Phototherapy appliances, their ultraviolet radiation and quality assurance of phototherapy. Terveydenhuollon laadunhallinta. Valohoitolaitteet, niiden UV- saeteily ja valohoitojen laadunvarmistus

    Energy Technology Data Exchange (ETDEWEB)

    Huurto, L.; Leszczynski, K.; Visuri, R.; Ylianttila, L.; Jokela, K. (Radiation and Nuclear Safety Authority, Helsinki (Finland))

    1998-01-01

    Artificial UV radiation (UVR) is used in the treatment of psoriasis and other skin diseases. Long term phototherapy is associated to increased risk of squamous cell carcinoma. This report gives a short review of biological effects of UVR and technical aspects of phototherapy units. The phototherapy units used in Finnish Central hospitals are described and the measured UVR dose rates of these units are presented. In addition, the UVR meters used in hospitals are described and the calibration factors are given for UVR dose rate measurements: Finally, recommendations are given for the quality assurance of photo-therapy units as well as for assessing UVR doses of patients. (orig.) 88 refs.

  12. Solar radiation trend across China in recent decades: a revisit with quality-controlled data

    Directory of Open Access Journals (Sweden)

    W.-J. Tang

    2011-01-01

    Full Text Available Solar radiation is one of the most important factors affecting climate and environment, and its long-term variation is of much concern in climate change studies. In the light of the limited number of radiation stations with reliable long-term time series observations, this paper presents a new evaluation of the long-term variation of surface solar radiation over China by combining quality-controlled observed data and two radiation models. One is the ANN-based (Artificial Neutral Network model and the other is a physical model. The two models produce radiation trends comparable to the observed ones at a few validation stations possessing reliable and continuous data. Then, the trend estimate is extended by the ANN-based model to all 96 radiation stations and furthermore extended by the physical model to all 716 China Meteorological Administration (CMA routine stations. The new trend estimate is different from previous ones in two aspects. First, the magnitude of solar radiation over China decreased by about −0.23 W m−2 yr−1 between 1961 and 2000, which is greatly less in magnitude than trend slopes estimated in previous studies (ranging over −0.41 ~ −0.52 W m−2 yr−1. Second, the "From Dimming to Brightening" transition in China during the late 1980s ~ the early 1990s was addressed in previous studies, but this study indicates the solar radiation reached a stable level since the 1990s and the transition is not noticeable. These differences indicate the importance of data-quality control and analysis approaches. Finally, an obvious transition from brightening to dimming around 1978 is found over the Tibetan Plateau, where aerosol loads are very low, indicating that the importance of cloud changes in altering solar radiation may be comparable to that of the aerosol changes.

  13. Effect of ionizing radiation on some quality attributes of nutraceutically valued lotus seeds.

    Science.gov (United States)

    Bhat, Rajeev; Karim, A A

    2009-01-01

    Radiation processing has been employed successfully for value addition of food and agricultural products. Preliminary studies were undertaken to evaluate the changes induced by ionizing radiation (up to 30 kGy), in the form of gamma irradiation and electron beam irradiation, on some quality attributes and nutritive values of nutraceutically valued lotus seeds. Significant loss in seed firmness was recorded between control and irradiated seeds, irrespective of radiation source. Similarly, the specific viscosity of irradiated lotus seeds decreased significantly up to a dose of 7.5 kGy. Starch increased after exposure to gamma or electron beam irradiation, whereas the total phenolic contents were decreased. Gamma irradiation revealed an enhancement in protein, while the electron beam showed a decrease. Partial oxidation of the seeds during radiation treatments might have occurred as evidenced from the decomposition profiles (thermogravimetry) during heating. It is evident that ionizing radiation brought about significant and variable changes in the quality and nutritive values of lotus seed. Further exploration of this technology for safety and quality is warranted.

  14. Photoluminescence in large fluence radiation irradiated space silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hisamatsu, Tadashi; Kawasaki, Osamu; Matsuda, Sumio [National Space Development Agency of Japan, Tsukuba, Ibaraki (Japan). Tsukuba Space Center; Tsukamoto, Kazuyoshi

    1997-03-01

    Photoluminescence spectroscopy measurements were carried out for silicon 50{mu}m BSFR space solar cells irradiated with 1MeV electrons with a fluence exceeding 1 x 10{sup 16} e/cm{sup 2} and 10MeV protons with a fluence exceeding 1 x 10{sup 13} p/cm{sup 2}. The results were compared with the previous result performed in a relative low fluence region, and the radiation-induced defects which cause anomalous degradation of the cell performance in such large fluence regions were discussed. As far as we know, this is the first report which presents the PL measurement results at 4.2K of the large fluence radiation irradiated silicon solar cells. (author)

  15. Enhancement of radiation response in human hepatocarcinoma cells by Metformin

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Ho; Kim, Won Woo; Kim, Joon; Jung, Won Gyun [Division of heavy ion clinical research, Korea University, Seoul (Korea, Republic of); Jeong, Jae Hoon; Jeong, Youn Kyoung; Kim, Mi Sook [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2012-11-15

    Metformin (1, 1-dimethylbiguanide hydrochloride), the most widely used drug to treat type 2 diabetic patients under benefit good tolerability profile and low cost, has sparked keen interest as potential anticancer agent. Preclinical studies showed that the primary mechanism of action of metformin is through its ability to activate AMP-activated protein kinase (AMPK). Metformin inhibits complex 1 in the mitochondrial electron transport chain, leading to an increase in the AMP-to-ATP ratio, then, phospholylated AMPK increase energy generation or suppress energy consumption and then, inhibits cell growth. However, important caveat in direct action theory of metformin is that millimorlar range, effective dose for inhibition tumor cell growth in vitro, cannot be achieved in patients. This is probably because metformin enter cells through the organic cation transporters OCT1 and OCT2, which is lowly expressed in human cells except liver and adipose cells. dependent pathway rather than through direct effects of the tumor cells. We analyzed combination effect of metformin and radiation focusing to HCC cell lines, which theoretically express high organic cation transporters, producing high centration of metformin in tumor cells. The purpose of this study is to investigate whether metformin had anti-tumor effects when combined with radiation as radiosensitizer in HCC. The results showed that metformin increased radiosensitizing efficacy in HCC cells , as well as in Huh7 xenograft mouse models. Interestingly, metformin effectively sensitizes IR-induced apoptosis in HCC through upregulation of cleaved PARP and caspase3 and increase synergically on DNA damage response with combined treatment.HCC, suggesting potential usefulness of combined therapy of metformin together with radiation for HCC cancer therapy.

  16. Transmission of clonal chromosomal abnormalities in human hematopoietic stem and progenitor cells surviving radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Kraft, Daniela, E-mail: d.kraft@gsi.de [GSI Helmholtz Center for Heavy Ion Research, Department of Biophysics, Planckstr. 1, 64291 Darmstadt (Germany); Institute for Transfusion Medicine und Immunohematology, DRK-Blutspendedienst Baden-Wuerttemberg—Hessen, Johann Wolfgang Goethe-University Hospital, Sandhofstrasse 1, 60528 Frankfurt (Germany); Ritter, Sylvia, E-mail: s.ritter@gsi.de [GSI Helmholtz Center for Heavy Ion Research, Department of Biophysics, Planckstr. 1, 64291 Darmstadt (Germany); Durante, Marco, E-mail: m.durante@gsi.de [GSI Helmholtz Center for Heavy Ion Research, Department of Biophysics, Planckstr. 1, 64291 Darmstadt (Germany); Institute for Condensed Matter Physics, Physics Department, Technical University Darmstadt, Hochschulstraße 6-8, 64289 Darmstadt (Germany); Seifried, Erhard, E-mail: e.seifried@blutspende.de [Institute for Transfusion Medicine und Immunohematology, DRK-Blutspendedienst Baden-Wuerttemberg—Hessen, Johann Wolfgang Goethe-University Hospital, Sandhofstrasse 1, 60528 Frankfurt (Germany); Fournier, Claudia, E-mail: c.fournier@gsi.de [GSI Helmholtz Center for Heavy Ion Research, Department of Biophysics, Planckstr. 1, 64291 Darmstadt (Germany); Tonn, Torsten, E-mail: t.tonn@blutspende.de [Institute for Transfusion Medicine und Immunohematology, DRK-Blutspendedienst Baden-Wuerttemberg—Hessen, Johann Wolfgang Goethe-University Hospital, Sandhofstrasse 1, 60528 Frankfurt (Germany); Technische Universität Dresden, Med. Fakultät Carl Gustav Carus, Institute for Transfusion Medicine Dresden, German Red Cross Blood Donation Service North-East, Blasewitzer Straße 68/70, 01307 Dresden (Germany)

    2015-07-15

    Highlights: • Radiation induced formation and transmission of chromosomal aberrations were assessed. • Cytogenetic analysis was performed in human CD34+ HSPC by mFISH. • We report transmission of stable aberrations in irradiated, clonally expanded HSPC. • Unstable aberrations in clonally expanded HSPC occur independently of irradiation. • Carbon ions and X-rays bear a similar risk for propagation of cytogenetic changes. - Abstract: In radiation-induced acute myeloid leukemia (rAML), clonal chromosomal abnormalities are often observed in bone marrow cells of patients, suggesting that their formation is crucial in the development of the disease. Since rAML is considered to originate from hematopoietic stem and progenitor cells (HSPC), we investigated the frequency and spectrum of radiation-induced chromosomal abnormalities in human CD34{sup +} cells. We then measured stable chromosomal abnormalities, a possible biomarker of leukemia risk, in clonally expanded cell populations which were grown for 14 days in a 3D-matrix (CFU-assay). We compared two radiation qualities used in radiotherapy, sparsely ionizing X-rays and densely ionizing carbon ions (29 and 60–85 keV/μm, doses between 0.5 and 4 Gy). Only a negligible number of de novo arising, unstable aberrations (≤0.05 aberrations/cell, 97% breaks) were measured in the descendants of irradiated HSPC. However, stable aberrations were detected in colonies formed by irradiated HSPC. All cells of the affected colonies exhibited one or more identical aberrations, indicating their clonal origin. The majority of the clonal rearrangements (92%) were simple exchanges such as translocations (77%) and pericentric inversions (15%), which are known to contribute to the development of rAML. Carbon ions were more efficient in inducing cell killing (maximum of ∼30–35% apoptotic cells for 2 Gy carbon ions compared to ∼25% for X-rays) and chromosomal aberrations in the first cell-cycle after exposure (∼70% and

  17. Radiation quality and ion-beam therapy: understanding the users' needs.

    Science.gov (United States)

    Magrin, G; Mayer, R; Verona, C; Grevillot, Loïc

    2015-09-01

    Ion-beam therapy faces a growing demand of tools able to map radiation quality within the irradiated volume. Although analytical computations and simulations provide useful estimations of dose and radiation quality, the direct measure of those parameters would improve ion-beam therapy in particular when deep-seated tumours are irradiated, tissue composition and density are variable or organs at risk are near the tumour. Several ion-beam therapy facilities are studying detectors and procedures for measuring the radiation quality on a microdosimetric as well as a nanodosimetric scale. Simplicity and miniaturisation of the devices are essential for measurements first in phantoms and thereafter during therapy, particularly for intra-cavity detectors. MedAustron is studying solid-state detectors based on a single crystal chemical vapour deposition diamond. In collaboration with Italian National Institute for Nuclear Physics (INFN), Tor Vergata and Legnaro; INFN-microdosimetry and track structure project; Austrian Institute of Technology, Vienna; and Italian National agency for new technologies, energy and sustainable economic development, Rome, prototypes have been developed to characterise radiation quality in sizes equivalent to one micrometre of biological tissue.

  18. Mechanisms of Ionizing Radiation-Induced Cell Death in Primary Lung Cells

    Science.gov (United States)

    2013-03-05

    journal of radiation biology:epublished ahead of print 35. Coggle JE, Lambert BE, Moores SR. 1986. Radiation effects in the lung. Environmental health...caspases and mitochondria. Cell Death Differ 8:829-40 46. Dimri GP, Lee X, Basile G, Acosta M, Scott G, et al. 1995. A biomarker that identifies senescent

  19. Temporal Dependence of Chromosomal Aberration on Radiation Quality and Cellular Genetic Background

    Science.gov (United States)

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

    2017-01-01

    Radiation induced cancer risks are driven by genetic instability. It is not well understood how different radiation sources induce genetic instability in cells with different genetic background. Here we report our studies on genetic instability, particularly chromosome instability using fluorescence in situ hybridization (FISH), in human primary lymphocytes, normal human fibroblasts, and transformed human mammary epithelial cells in a temporal manner after exposure to high energy protons and Fe ions. The chromosome spread was prepared 48 hours, 1 week, 2 week, and 1 month after radiation exposure. Chromosome aberrations were analyzed with whole chromosome specific probes (chr. 3 and chr. 6). After exposure to protons and Fe ions of similar cumulative energy (??), Fe ions induced more chromosomal aberrations at early time point (48 hours) in all three types of cells. Over time (after 1 month), more chromosome aberrations were observed in cells exposed to Fe ions than in the same type of cells exposed to protons. While the mammary epithelial cells have higher intrinsic genetic instability and higher rate of initial chromosome aberrations than the fibroblasts, the fibroblasts retained more chromosomal aberration after long term cell culture (1 month) in comparison to their initial frequency of chromosome aberration. In lymphocytes, the chromosome aberration frequency at 1 month after exposure to Fe ions was close to unexposed background, and the chromosome aberration frequency at 1 month after exposure to proton was much higher. In addition to human cells, mouse bone marrow cells isolated from strains CBA/CaH and C57BL/6 were irradiated with proton or Fe ions and were analyzed for chromosome aberration at different time points. Cells from CBA mice showed similar frequency of chromosome aberration at early and late time points, while cells from C57 mice showed very different chromosome aberration rate at early and late time points. Our results suggest that relative

  20. Strain-related differences and radiation quality effects on mouse leukocytes: gamma-rays and protons (with and without aluminum shielding).

    Science.gov (United States)

    Gridley, Daila S; Pecaut, Michael J; Green, Lora M; Sanchez, Martha C; Kadhim, Munira A

    2011-01-01

    Increasing evidence indicates that radiation-induced genomic instability plays an important role in the development of cancer. However, radiation quality and genetic background can influence the outcome. The goal of this study was to quantify radiation-induced changes in lymphocyte populations in mouse strains known to differ in susceptibility to genomic instability (C57BL/6, resistant; CBA/Ca, susceptible). The effects of whole-body exposure to γ-rays and protons, with and without aluminum shielding, were compared. Total radiation doses of 0, 0.1, 0.5, and 2.0 Gy were delivered and subsets of mice from each group were euthanized on days 1 and 30 after exposure for spleen and bone marrow analyses. In the spleen on day 1, lymphocyte counts were decreased (pshielded protons. Some strain- and radiation-dependent differences were also noted in percentages of specific lymphocyte populations (T, B, NK) and the CD4:CD8 ratio. In bone marrow, percentages of stem/progenitor cells (CD34(+), Ly-6A/E(+), CD34(+)Ly-6A/E(+)) were generally highest 1 day after 2 Gy irradiation, regardless of strain and radiation type. Based on dUTP incorporation, bone marrow cells from C57 mice had consistently higher levels of DNA damage on day 30 after irradiation with doses less than 2 Gy, regardless of quality. Annexin V binding supported the conclusion that C57 bone marrow cells were more susceptible to radiation-induced apoptosis. Overall, the data indicate that leukocytes of CBA mice are less sensitive to the effects of high-linear energy transfer radiation (shielded protons) than C57 mice, a phenomenon consistent with increased possibility for genomic instability and progression to a malignant cell phenotype after sublethal damage.

  1. From DNA radiation damage to cell death: theoretical approaches.

    Science.gov (United States)

    Ballarini, Francesca

    2010-10-05

    Some representative models of radiation-induced cell death, which is a crucial endpoint in radiobiology, were reviewed. The basic assumptions were identified, their consequences on predicted cell survival were analyzed, and the advantages and drawbacks of each approach were outlined. In addition to "historical" approaches such as the Target Theory, the Linear-Quadratic model, the Theory of Dual Radiation Action and Katz' model, the more recent Local Effect Model was discussed, focusing on its application in Carbon-ion hadrontherapy. Furthermore, a mechanistic model developed at the University of Pavia and based on the relationship between cell inactivation and chromosome aberrations was presented, together with recent results; the good agreement between model predictions and literature experimental data on different radiation types (photons, protons, alpha particles, and Carbon ions) supported the idea that asymmetric chromosome aberrations like dicentrics and rings play a fundamental role for cell death. Basing on these results, a reinterpretation of the TDRA was also proposed, identifying the TDRA "sublesions" and "lesions" as clustered DNA double-strand breaks and (lethal) chromosome aberrations, respectively.

  2. From DNA Radiation Damage to Cell Death: Theoretical Approaches

    Directory of Open Access Journals (Sweden)

    Francesca Ballarini

    2010-01-01

    Full Text Available Some representative models of radiation-induced cell death, which is a crucial endpoint in radiobiology, were reviewed. The basic assumptions were identified, their consequences on predicted cell survival were analyzed, and the advantages and drawbacks of each approach were outlined. In addition to “historical” approaches such as the Target Theory, the Linear-Quadratic model, the Theory of Dual Radiation Action and Katz' model, the more recent Local Effect Model was discussed, focusing on its application in Carbon-ion hadrontherapy. Furthermore, a mechanistic model developed at the University of Pavia and based on the relationship between cell inactivation and chromosome aberrations was presented, together with recent results; the good agreement between model predictions and literature experimental data on different radiation types (photons, protons, alpha particles, and Carbon ions supported the idea that asymmetric chromosome aberrations like dicentrics and rings play a fundamental role for cell death. Basing on these results, a reinterpretation of the TDRA was also proposed, identifying the TDRA “sublesions” and “lesions” as clustered DNA double-strand breaks and (lethal chromosome aberrations, respectively.

  3. The quality of radiation care: the results of focus group interviews and concept mapping to explore the patient's perspective.

    NARCIS (Netherlands)

    Nijman, J.L.; Sixma, H.; Triest, B. van; Keus, R.B.; Hendriks, M.

    2012-01-01

    Background and purpose: In this study, we explore the quality aspects of radiation care from the patient’s perspective in order to develop a draft Consumer Quality Index (CQI) Radiation Care instrument. Materials and methods: Four focus group discussions with (former) cancer patients were held to ex

  4. Quality assurance in military medical research and medical radiation accident management.

    Science.gov (United States)

    Hotz, Mark E; Meineke, Viktor

    2012-08-01

    The provision of quality radiation-related medical diagnostic and therapeutic treatments cannot occur without the presence of robust quality assurance and standardization programs. Medical laboratory services are essential in patient treatment and must be able to meet the needs of all patients and the clinical personnel responsible for the medical care of these patients. Clinical personnel involved in patient care must embody the quality assurance process in daily work to ensure program sustainability. In conformance with the German Federal Government's concept for modern departmental research, the international standard ISO 9001, one of the relevant standards of the International Organization for Standardization (ISO), is applied in quality assurance in military medical research. By its holistic approach, this internationally accepted standard provides an excellent basis for establishing a modern quality management system in line with international standards. Furthermore, this standard can serve as a sound basis for the further development of an already established quality management system when additional standards shall apply, as for instance in reference laboratories or medical laboratories. Besides quality assurance, a military medical facility must manage additional risk events in the context of early recognition/detection of health risks of military personnel on deployment in order to be able to take appropriate preventive and protective measures; for instance, with medical radiation accident management. The international standard ISO 31000:2009 can serve as a guideline for establishing risk management. Clear organizational structures and defined work processes are required when individual laboratory units seek accreditation according to specific laboratory standards. Furthermore, international efforts to develop health laboratory standards must be reinforced that support sustainable quality assurance, as in the exchange and comparison of test results within

  5. Radiation response of mesenchymal stem cells derived from bone marrow and human pluripotent stem cells

    OpenAIRE

    Islam, Mohammad S; Stemig, Melissa E.; Takahashi, Yutaka; Hui, Susanta K.

    2014-01-01

    Mesenchymal stem cells (MSCs) isolated from human pluripotent stem cells are comparable with bone marrow-derived MSCs in their function and immunophenotype. The purpose of this exploratory study was comparative evaluation of the radiation responses of mesenchymal stem cells derived from bone marrow- (BMMSCs) and from human embryonic stem cells (hESMSCs). BMMSCs and hESMSCs were irradiated at 0 Gy (control) to 16 Gy using a linear accelerator commonly used for cancer treatment. Cells were harv...

  6. Mammalian stem cells reprogramming in response to terahertz radiation.

    Directory of Open Access Journals (Sweden)

    Jonathan Bock

    Full Text Available We report that extended exposure to broad-spectrum terahertz radiation results in specific changes in cellular functions that are closely related to DNA-directed gene transcription. Our gene chip survey of gene expression shows that whereas 89% of the protein coding genes in mouse stem cells do not respond to the applied terahertz radiation, certain genes are activated, while other are repressed. RT-PCR experiments with selected gene probes corresponding to transcripts in the three groups of genes detail the gene specific effect. The response was not only gene specific but also irradiation conditions dependent. Our findings suggest that the applied terahertz irradiation accelerates cell differentiation toward adipose phenotype by activating the transcription factor peroxisome proliferator-activated receptor gamma (PPARG. Finally, our molecular dynamics computer simulations indicate that the local breathing dynamics of the PPARG promoter DNA coincides with the gene specific response to the THz radiation. We propose that THz radiation is a potential tool for cellular reprogramming.

  7. DNA Damage by Radiation in Tradescantia Leaf Cells

    Energy Technology Data Exchange (ETDEWEB)

    Han, Min; Hyun, Kyung Man; Ryu, Tae Ho; Kim, Jin Kyu [Korea Atomic Energy Research Institute, Advanced Radiation Technology Institute, Jeongeup (Korea, Republic of); Nili, Mohammad [Dawnesh Radiation Research Institute, Barcelona (Spain)

    2010-04-15

    The comet assay is currently used in different areas of biological sciences to detect DNA damage. The comet assay, due to its simplicity, sensitivity and need of a few cells, is ideal as a short-term genotoxicity test. The comet assay can theoretically be applied to every type of eukaryotic cell, including plant cells. Plants are very useful as monitors of genetic effects caused by pollution in the atmosphere, water and soil. Tradescantia tests are very useful tools for screening the mutagenic potential in the environment. Experiments were conducted to study the genotoxic effects of ionizing radiations on the genome integrity, particularly of Tradescantia. The increasingly frequent use of Tradescantia as a sensitive environmental bioindicator of genotoxic effects. This study was designed to assess the genotoxicity of ionizing radiation using Tradescnatia-comet assay. The development of comet assay has enabled investigators to detect DNA damage at the levels of cells. To adapt this assay to plant cells, nuclei were directly obtained from Tradescantia leaf samples. A significant dose-dependent increase in the average tail moment values over the negative control was observed. Recently the adaptation of this technique to plant cells opens new possibilities for studies in variety area. The future applications of the comet assay could impact some other important areas, certainly, one of the limiting factors to its utility is the imagination of the investigator.

  8. Studies on the control mechanism and the degenerative immune function of dendritic cells using radiation

    Energy Technology Data Exchange (ETDEWEB)

    Yee, Sung Tae; Kim, Jong Jin; Choi, Ji Na; Park, Jung Eun; Jeong, Young Ran [Sunchon National University, Sunchon (Korea, Republic of)

    2010-05-15

    Dendritic cells are actively used as cellular adjuvant in cancer immunotherapy. However, although DC immunotherapies primarily target the elderly population, little is known about the effect of aging on DC functions. Here, we compared the T-cell stimulation, cytokine production, and costimulatory molecule expression of spleen or bone marrow-derived CD11c{sup +} DCs of C57BL/6 mice. In the first year, we compared various function of dendritic cells isolated from young and gamma-irradiated 57BL/6 mice(5 weeks after {gamma}-radiation) for the development of aging models using radiation. In the second year, we also compared the function of spleen- and bone marrow-derived dendritic cells of young(2-3 months) and old(23-24 months) 57BL/6 mice. And we studied the differences of spleen- and bone marrow-derived dendritic cells of young and gamma-irradiated 57BL/6 mice(2, 4, 6 months after {gamma}-radiation) for the development of aging models in third year. And we obtained various differences between spleen- and bone marrow-derived dendritic cells of normal and old(23-24 months) or {gamma}-irradiated 57BL/6 mice. It is possible to use our results as age-associated model for modulation of the declined immunity and hematopoiesis for treatment of cancer, adult diseases and stress in aging. Such studies on the mechanism of aging model would further lead to new avenues for the development of functional foods which effect such as pathogenesis, inflammatory and autoimmune disorders. It will contributed to activation of related industry conforming quality and diversity of radiation industry. The techniques developed in our research may provide novel therapeutic modalities for age-associated immune dysfunctions

  9. NMR imaging of cell phone radiation absorption in brain tissue.

    Science.gov (United States)

    Gultekin, David H; Moeller, Lothar

    2013-01-02

    A method is described for measuring absorbed electromagnetic energy radiated from cell phone antennae into ex vivo brain tissue. NMR images the 3D thermal dynamics inside ex vivo bovine brain tissue and equivalent gel under exposure to power and irradiation time-varying radio frequency (RF) fields. The absorbed RF energy in brain tissue converts into Joule heat and affects the nuclear magnetic shielding and the Larmor precession. The resultant temperature increase is measured by the resonance frequency shift of hydrogen protons in brain tissue. This proposed application of NMR thermometry offers sufficient spatial and temporal resolution to characterize the hot spots from absorbed cell phone radiation in aqueous media and biological tissues. Specific absorption rate measurements averaged over 1 mg and 10 s in the brain tissue cover the total absorption volume. Reference measurements with fiber optic temperature sensors confirm the accuracy of the NMR thermometry.

  10. Patient Specification Quality Assurance for Glioblastoma Multiforme Brain Tumors Treated with Intensity Modulated Radiation Therapy

    Directory of Open Access Journals (Sweden)

    H. I. Al-Mohammed

    2011-01-01

    Full Text Available The aim of this study was to evaluate the significance of performing patient specification quality assurance for patients diagnosed with glioblastoma multiforme treated with intensity modulated radiation therapy. The study evaluated ten intensity modulated radiation therapy treatment plans using 10 MV beams, a total dose of 60 Gy (2 Gy/fraction, five fractions a week for a total of six weeks treatment. For the quality assurance protocol we used a two-dimensional ionization-chamber array (2D-ARRAY. The results showed a very good agreement between the measured dose and the pretreatment planned dose. All the plans passed >95% gamma criterion with pixels within 5% dose difference and 3 mm distance to agreement. We concluded that using the 2D-ARRAY ion chamber for intensity modulated radiation therapy is an important step for intensity modulated radiation therapy treatment plans, and this study has shown that our treatment planning for intensity modulated radiation therapy is accurately done.

  11. Discrimination of radiation quality through second harmonic out-of-phase cw-ESR detection.

    Science.gov (United States)

    Marrale, Maurizio; Longo, Anna; Brai, Maria; Barbon, Antonio; Brustolon, Marina

    2014-02-01

    The ability to discriminate the quality of ionizing radiation is important because the biological effects produced in tissue strongly depends on both absorbed dose and linear energy transfer (LET) of ionizing particles. Here we present an experimental electron spin resonance (ESR) analysis aimed at discriminating the effective LETs of various radiation beams (e.g., 19.3 MeV protons, (60)Co photons and thermal neutrons). The measurement of the intensities of the continuous wave spectrometer signal channel first harmonic in-phase and the second harmonic out-of-phase components are used to distinguish the radiation quality. A computational analysis, was carried out to evaluate the dependence of the first harmonic in-phase and second harmonic out-of-phase components on microwave power, modulation amplitude and relaxation times, and highlights that these components could be used to point out differences in the relaxation times. On the basis of this numerical analysis the experimental results are discussed. The methodology described in this study has the potential to provide information on radiation quality.

  12. NMR imaging of cell phone radiation absorption in brain tissue

    OpenAIRE

    Gultekin, David H.; Moeller, Lothar

    2012-01-01

    A method is described for measuring absorbed electromagnetic energy radiated from cell phone antennae into ex vivo brain tissue. NMR images the 3D thermal dynamics inside ex vivo bovine brain tissue and equivalent gel under exposure to power and irradiation time-varying radio frequency (RF) fields. The absorbed RF energy in brain tissue converts into Joule heat and affects the nuclear magnetic shielding and the Larmor precession. The resultant temperature increase is measured by the resonance...

  13. Tinnitus and cell phones: the role of electromagnetic radiofrequency radiation

    OpenAIRE

    Seyed Mohammad Javad Mortazavi; Seyed Ali Reza Mortazavi

    2016-01-01

    ABSTRACT INTRODUCTION: Tinnitus is a multifactorial condition and its prevalence has increased on the past decades. The worldwide progressive increase of the use of cell phones has exposed the peripheral auditory pathways to a higher dose of electromagnetic radiofrequency radiation (EMRFR). Some tinnitus patients report that the abusive use of mobiles, especially when repeated in the same ear, might worsen ipsilateral tinnitus. OBJECTIVE: The aim of this study was to evaluate the availabl...

  14. Set up and operation for medical radiation exposure quality control system of health promotion center

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Su; Kim, Jung Min [Korea University,Seoul (Korea, Republic of); Jung, Hae Kyoung [Dept. of Diagnostic Radiology, CHA Bundang Medical Center, CHA University, Sungnam (Korea, Republic of)

    2016-03-15

    In this study, standard model of medical radiation dosage quality control system will be suggested and the useful of this system in clinical field will be reviewed. Radiation dosage information of modalities are gathered from digital imaging and communications in medicine(DICOM) standard data(such as DICOM dose SR and DICOM header) and stored in database. One CT scan, two digital radiography modalities and two mammography modalities in one health promotion center in Seoul are used to derive clinical data for one month. After 1 months research with 703 CT scans, the study shows CT 357.9 mGy·cm in abdomen and pelvic CT, 572.4 mGy·cm in brain without CT, 55.9 mGy·cm in calcium score/heart CT, screening CT at 54 mGy·cm in chest screening CT(low dose screening CT scan), 284.99 mGy·cm in C-spine CT and 341.85 mGy·cm in L-spine CT as health promotion center reference level of each exam. And with 1955 digital radiography cases, it shows 274.0 mGy·cm{sup 2} and for mammography 6.09 mGy is shown based on 536 cases. The use of medical radiation shall comply with the principles of justification and optimization. This quality management of medical radiation exposure must be performed in order to follow the principle. And the procedure to reduce the radiation exposure of patients and staff can be achieved through this. The results of this study can be applied as a useful tool to perform the quality control of medical radiation exposure.

  15. Remarks on the radiation chemistry of radiation damage in cells. [X radiation, electrons

    Energy Technology Data Exchange (ETDEWEB)

    Powers, E.L.

    1975-01-01

    Several models of the actions of compounds that sensitize cells to x-irradiation are reviewed and commented on. The electron sequestration model is described in detail and typical experimental results upon which it is based are reviewed. The varieties of responses induced by a number of sensitizers and their antagonists are stressed; there is no single, simple chemical explanation that can account for all the results. However, the importance of the e/sup -//sub aq/ -- .OH relation is evident in all the experimental results with the compounds tested to date.

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

    CERN Document Server

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

    2010-01-01

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

  17. Data Quality Objectives Supporting the Environmental Direct Radiation Monitoring Program for the INL Site

    Energy Technology Data Exchange (ETDEWEB)

    Lundell, J. F. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Magnuson, S. O. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Scherbinske, P. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Case, M. J. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-07-01

    This document presents the development of the data quality objectives (DQOs) for the Idaho National Laboratory (INL) Environmental Direct Radiation Monitoring Program and follows the Environmental Protection Agency (EPA) DQO process (EPA 2006). This document also develops and presents the logic to determine the specific number of direct radiation monitoring locations around INL facilities on the desert west of Idaho Falls and in Idaho Falls, at locations bordering the INL Site, and in the surrounding regional area. The selection logic follows the guidance from the Department of Energy (DOE) (2015) for environmental surveillance of DOE facilities.

  18. Image quality vs. radiation dose for a flat-panel amorphous silicon detector: a phantom study.

    Science.gov (United States)

    Geijer, H; Beckman, K W; Andersson, T; Persliden, J

    2001-01-01

    The aim of this study was to investigate the image quality for a flat-panel amorphous silicon detector at various radiation dose settings and to compare the results with storage phosphor plates and a screen-film system. A CDRAD 2.0 contrast-detail phantom was imaged with a flat-panel detector (Philips Medical Systems, Eindhoven, The Netherlands) at three different dose levels with settings for intravenous urography. The same phantom was imaged with storage phosphor plates at a simulated system speed of 200 and a screen-film system with a system speed of 160. Entrance surface doses were recorded for all images. At each setting, three images were read by four independent observers. The flat-panel detector had equal image quality at less than half the radiation dose compared with storage phosphor plates. The difference was even larger when compared with film with the flat-panel detector having equal image quality at approximately one-fifth the dose. The flat-panel detector has a very favourable combination of image quality vs radiation dose compared with storage phosphor plates and screen film.

  19. Image quality vs radiation dose for a flat-panel amorphous silicon detector: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Geijer, H.; Andersson, T. [Dept. of Radiology, Oerebro Medical Centre Hospital (Sweden); Beckman, K.W.; Persliden, J. [Dept. of Medical Physics, Oerebro Medical Centre Hospital (Sweden)

    2001-09-01

    The aim of this study was to investigate the image quality for a flat-panel amorphous silicon detector at various radiation dose settings and to compare the results with storage phosphor plates and a screen-film system. A CDRAD 2.0 contrast-detail phantom was imaged with a flat-panel detector (Philips Medical Systems, Eindhoven, The Netherlands) at three different dose levels with settings for intravenous urography. The same phantom was imaged with storage phosphor plates at a simulated system speed of 200 and a screen-film system with a system speed of 160. Entrance surface doses were recorded for all images. At each setting, three images were read by four independent observers. The flat-panel detector had equal image quality at less than half the radiation dose compared with storage phosphor plates. The difference was even larger when compared with film with the flat-panel detector having equal image quality at approximately one-fifth the dose. The flat-panel detector has a very favourable combination of image quality vs radiation dose compared with storage phosphor plates and screen film. (orig.)

  20. Response of human HTB140 melanoma cells to conventional radiation and hadrons.

    Science.gov (United States)

    Ristić-Fira, A; Todorović, D; Zakula, J; Keta, O; Cirrone, P; Cuttone, G; Petrović, I

    2011-01-01

    Conventional radiotherapy with X- and gamma-rays is one of the common and effective treatments of cancer. High energy hadrons, i.e., charged particles like protons and (12)C ions, due to their specific physics and radiobiological advantages are increasingly used. In this study, effectiveness of different radiation types is evaluated on the radio-resistant human HTB140 melanoma cells. The cells were irradiated with gamma-rays, the 62 MeV protons at the Bragg peak and in the middle of the spread-out Bragg peak (SOBP), as well as with the 62 MeV/u (12)C ions. The doses ranged from 2 to 24 Gy. Cell survival and proliferation were assessed 7 days after irradiation, whereas apoptosis was evaluated after 48 h. The acquired results confirmed the high radio-resistance of cells, showing better effectiveness of protons than gamma-rays. The best efficiency was obtained with (12)C ions due to higher linear energy transfer. All analyzed radiation qualities reduced cell proliferation. The highest proliferation was detected for (12)C ions because of their large killing capacity followed by small induction of reparable lesions. This enabled unharmed cells to preserve proliferative activity. Irradiations with protons and (12)C ions revealed similar moderate pro-apoptotic ability that is in agreement with the level of cellular radio-resistance.

  1. Radiation-induced cisplatin resistance in two human cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Eichholtz-Wirth, H.; Stotzer, O. [GSF-Institute of Radiobiology and Cytometry, Neuherberg (Germany); Marx, K. [Medical Clin. III, University, Munich (Germany)

    1997-03-01

    Cisplatin resistance has been induced in human HT-29 and HeLa cells after low-dose fractionated {gamma}-irradiation. The drug resistance is modest and does not confer cross-resistance to irradiation. Alterations that were recently shown to correlate with radiation-induced cisplatin resistance in murine cells are not involved in the resistant HeLa-C3 cells. Scavengers, such as GSH or metallothioneins are unchanged and there is no alteration of the cGMP transduction pathway. Preliminary results in HeLa-C3 cells indicate that resistance is associated with differences of the apoptotic pathway, with enhancement of the p53 suppressor protein after cisplatin treatment but unchanged bcl-2 protein expression. (authors)

  2. Solar radiation trend across China in recent decades: a revisit with quality-controlled data

    Directory of Open Access Journals (Sweden)

    W.-J. Tang

    2010-08-01

    Full Text Available Solar radiation is one of the most important factors affecting climate and environment, and its long-term variation is of much concern in climate change studies. In the light of the limited number of radiation stations with reliable long-term time series observations, this paper presents a new evaluation of the long-term variation of surface solar radiation over China by combining quality-controlled observed data and two radiation models. One is the ANN-based (Artificial Neutral Network model and the other is a physical one. The two models produced radiation trends comparable to the observed ones at a few stations possessing reliable and continuous data. Then, the trend estimation is extended by the ANN-based model to all 96 radiation stations and furthermore extended by the physical model to all 716 China Meteorological Administration (CMA routine stations. The new estimate trend is different from previous ones in two aspects. First, the magnitude of solar radiation over China decreased by about −0.19 W m−2 yr−1 between 1961 and 2000, which is greatly less in magnitude than trends estimated in previous studies (ranging over −0.41 to −0.52 W m−2 yr−1. Second, the "From Dimming to Brightening" transition in China during the late 1980s and the early 1990s was addressed in previous studies, but this study indicates the solar radiation reached a stable level since the 1990s and the transition is not noticeable. These differences are attributed to inappropriate data and approaches in previous studies.

  3. Neoplastic human embryonic stem cells as a model of radiation resistance of human cancer stem cells.

    Science.gov (United States)

    Dingwall, Steve; Lee, Jung Bok; Guezguez, Borhane; Fiebig, Aline; McNicol, Jamie; Boreham, Douglas; Collins, Tony J; Bhatia, Mick

    2015-09-08

    Studies have implicated that a small sub-population of cells within a tumour, termed cancer stem cells (CSCs), have an enhanced capacity for tumour formation in multiple cancers and may be responsible for recurrence of the disease after treatment, including radiation. Although comparisons have been made between CSCs and bulk-tumour, the more important comparison with respect to therapy is between tumour-sustaining CSC versus normal stem cells that maintain the healthy tissue. However, the absence of normal known counterparts for many CSCs has made it difficult to compare the radiation responses of CSCs with the normal stem cells required for post-radiotherapy tissue regeneration and the maintenance of tissue homeostasis. Here we demonstrate that transformed human embryonic stem cells (t-hESCs), showing features of neoplastic progression produce tumours resistant to radiation relative to their normal counterpart upon injection into immune compromised mice. We reveal that t-hESCs have a reduced capacity for radiation induced cell death via apoptosis and exhibit altered cell cycle arrest relative to hESCs in vitro. t-hESCs have an increased expression of BclXL in comparison to their normal counterparts and re-sensitization of t-hESCs to radiation upon addition of BH3-only mimetic ABT737, suggesting that overexpression of BclXL underpins t-hESC radiation insensitivity. Using this novel discovery platform to investigate radiation resistance in human CSCs, our study indicates that chemotherapy targeting Bcl2-family members may prove to be an adjuvant to radiotherapy capable of targeting CSCs.

  4. Radiation safety and quality assurance in diagnostic x-ray imaging 1999; Saeteilyturvallisuus ja laadunvarmistus roentgendiagnostiikassa 1999

    Energy Technology Data Exchange (ETDEWEB)

    Servonmaa, A. [ed.

    1999-04-01

    In the European Union, the Directive 97/43/Euratom concerning the medical use of radiation brings many new tasks to radiation users. Quality assurance, patient dose measurement, staff training and clinical audit are among the most essential of these tasks. The Finnish radiation legislation has been modified to comply with the Directive. Much work is still required for practical implementation of these rules. This report deals with applications of the medical radiation Directive. Most applications are still at the planning stage, and clear guidance is lacking. However, the users have to know in time about these plans and future duties concerning them. Experience on quality assurance and clinical audit in hospitals are especially valuable in providing practical information on benefits and problems of these practices. Other radiation related topics, such as radiation risks, radioactivity in foods, and use of radiation in other European countries, are also included in the report. (orig.)

  5. Quality assurance in radiotherapy: from radiation physics to patient- and trial-oriented control procedures.

    Science.gov (United States)

    Bernier, J; Horiot, J C; Poortmans, P

    2002-03-01

    The stepwise process of the EORTC Quality Assurance Programme in Radiotherapy is described in function of two main criteria: the targets of the quality control procedures implemented, in Radiation Physics and clinical research, by the EORTC Radiotherapy Group and the development of both trial- and patient-oriented quality systems. This exhaustive program, which started in 1982, is characterised by three main periods. The first one was fully dedicated to pioneer steps in Radiation Physics measurements, on-site audits and inventories of human resources, staff workload and department infrastructure in institutions participating to EORTC trials. During the second period, which started in the late 1980s, a series of quality systems were implemented to test the compliance of the investigators to follow protocol guidelines, through the use of standard and uniform control procedures like the dummy runs, in order to tackle systematic errors in the participating institutions. Finally, the third period, which took place in the 1990s, was essentially patient-oriented, thanks to large scale individual case reviews, to check the validity of data recording and reporting processes and trace random errors throughout the radiotherapy treatments. Most of the results collected during these two decades allowed the implementation of well codified quality control procedures which, nowadays, can be used outside the field of clinical research, by national societies or bodies willing to improve treatment standards on a large scale.

  6. Key Performance Indicators in the Evaluation of the Quality of Radiation Safety Programs.

    Science.gov (United States)

    Schultz, Cheryl Culver; Shaffer, Sheila; Fink-Bennett, Darlene; Winokur, Kay

    2016-08-01

    Beaumont is a multiple hospital health care system with a centralized radiation safety department. The health system operates under a broad scope Nuclear Regulatory Commission license but also maintains several other limited use NRC licenses in off-site facilities and clinics. The hospital-based program is expansive including diagnostic radiology and nuclear medicine (molecular imaging), interventional radiology, a comprehensive cardiovascular program, multiple forms of radiation therapy (low dose rate brachytherapy, high dose rate brachytherapy, external beam radiotherapy, and gamma knife), and the Research Institute (including basic bench top, human and animal). Each year, in the annual report, data is analyzed and then tracked and trended. While any summary report will, by nature, include items such as the number of pieces of equipment, inspections performed, staff monitored and educated and other similar parameters, not all include an objective review of the quality and effectiveness of the program. Through objective numerical data Beaumont adopted seven key performance indicators. The assertion made is that key performance indicators can be used to establish benchmarks for evaluation and comparison of the effectiveness and quality of radiation safety programs. Based on over a decade of data collection, and adoption of key performance indicators, this paper demonstrates one way to establish objective benchmarking for radiation safety programs in the health care environment.

  7. International perspectives on quality assurance and new techniques in radiation medicine: outcomes of an IAEA conference.

    Science.gov (United States)

    Shortt, Ken; Davidsson, Lena; Hendry, Jolyon; Dondi, Maurizio; Andreo, Pedro

    2008-01-01

    The International Atomic Energy Agency organized an international conference called, "Quality Assurance and New Techniques in Radiation Medicine" (QANTRM). It dealt with quality assurance (QA) in all aspects of radiation medicine (diagnostic radiology, nuclear medicine, and radiotherapy) at the international level. Participants discussed QA issues pertaining to the implementation of new technologies and the need for education and staff training. The advantage of developing a comprehensive and harmonized approach to QA covering both the technical and the managerial issues was emphasized to ensure the optimization of benefits to patient safety and effectiveness. The necessary coupling between medical radiation imaging and radiotherapy was stressed, particularly for advanced technologies. However, the need for a more systematic approach to the adoption of advanced technologies was underscored by a report on failures in intensity-modulated radiotherapy dosimetry auditing tests in the United States, which could imply inadequate implementation of QA for these new technologies. A plenary session addressed the socioeconomic impact of introducing advanced technologies in resource-limited settings. How shall the dual gaps, one in access to basic medical services and the other in access to high-quality modern technology, be addressed?

  8. Alterations induced in Escherichia Coli cells by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kappke, J.; Schelin, H.R.; Paschuk, S.A.; Denyak, V.; Silva, E.R. da [Federal University of Technology of Parana (CPGEI/UTFPR), Curitiba, PR (Brazil)]. E-mails: jaquekap@yahoo.com.br; schelin@cpgei.cefetpr.br; sergei@utfpr.edu.br; Jesus, E.F.O. de; Lopes, R.T. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Instrumentacao Nuclear]. E-mails: ricardo@lin.ufrj.br; edgar@lin.ufrj.br; Carlin, N.; Toledo, E.S. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Fisica]. E-mail: nelson.carlin@dfn.if.usp.br

    2007-07-01

    Modifications occurred in Escherichia coli cells exposed to gamma radiation ({sup 60}Co source) were investigated. The irradiations were done at the LIN-COPPE laboratory of the UFRJ and the analysis at the Biology Department of the UTFPR. The E. coli cells were irradiated with 30, 60, 90, 120, 150, 180, 210, 240, 300, 480, 600 e 750 Gy doses. The samples were analyzed with Gram-stain, biochemical tests in EPM, MIO and Lysine Broth, Simmons Cytrate Medium and Rhamnose Broth, antibiogram and isolation of auxotrophic mutants. It was observed that for the received doses the E. coli did not show morphological alterations in the tests. Some E. Coli cells showed to be able to deaminade the L-tryptophan or they changed their sensibility for amoxillin and cephaloonine after the irradiation. The existence of aauxotrophic mutants after irradiation was also verified. (author)

  9. Kualitas Spermatozoa Mencit yang Terpapar Radiasi Sinar-X Secara Berulang (SPERMATOZOA QUALITY OF MICE EXPOSED TO X-RAYS RADIATION IN REPEATED

    Directory of Open Access Journals (Sweden)

    Ni Wayan Sudatri

    2015-05-01

    Full Text Available In radiology, X-ray has been used to diagnose disease and therapy. However, behind the technologybenefits provided by the radiation, the negative effects are often debated. The purpose of this study was toinvestigate the effects of repeated radiation on sperm quality mice (Mus musculus L. Thirty- two adultmale mice aged three months were divided into groups P1 (1x 200 rad, P2 (2x200 rad, P3 (3x200 rad andcontrol irradiated with x-rays according to the experimental design . Spermatozoa quality parametersobserved were : number of spermatozoa, motility, viability and morphology of spermatozoa. The results ofthe Post Hoc LSD tests for significant differences (P>0.05 between the control and treatment showed thatthe X-ray radiation exposure to 1x200 rad, 2x200 rad, and 3x200 rad decreases the motility, viability,normal morphology and number spermatozoa produced compared with controls. This is caused by exposureto X-ray radiation causes the formation of free radicals in the body that damage sperm cells mice. Exposureto X-ray radiation repeatedly lowered the quality of spermatozoa of mice.

  10. Response of hematopoietic stem cells to ionizing radiation; Reponse des cellules souches hematopoitiques aux radiations ionisantes

    Energy Technology Data Exchange (ETDEWEB)

    Simonnet, A

    2008-12-15

    Hematopoietic stem cells (HSCs) maintain blood and immune system throughout life and restore them after hematological injuries. Exposure of an organism to ionizing radiation (IR) causes rapid and acute myelosuppression and challenges the replenishment capacity of HSCs. Yet, the precise damages that are generated remain largely unexplored. To better understand these effects, phenotypic and functional changes in the stem/progenitor compartments of sublethally irradiated mice were monitored over a ten week period after radiation exposure. We report that shortly after sublethal IR-exposure, HSCs, defined by their repopulating ability, still segregate in the Hoechst dye excluding side population (SP); yet, their Sca-1 (S) and c-Kit (K) expression levels are increased and severely reduced, respectively, with a concurrent increase in the proportion of SP{sup SK} cells positive for established indicators of HSC presence: CD150{sup +} and CD105{sup +}. A great proportion of HSCs quickly but transiently enter the cell cycle to replenish the bone marrow of myelo-ablated mice. Ten weeks after, whereas bone marrow cellularity has recovered and hematopoietic homeostasis is restored, major phenotypic modifications can be observed within the Lin{sup -/low} Sca-1{sup +} c-Kit{sup +} (LSK) stem/progenitor compartment: CD150{sup +}/Flk2{sup -} and CD150{sup -}/Flk2{sup +} LSK cell frequencies are increased and dramatically reduced, respectively. CD150{sup +} LSK cells also show impaired reconstitution capacity, accrued number of {gamma}-H2AX foci and increased tendency to apoptosis. This demonstrates that the LSK compartment is not properly restored 10 weeks after sublethal exposure, and that long-term IR-induced injury to the bone marrow proceeds, at least partially, through direct damage to the stem cell pool. Thrombopoietin (TPO) has been shown to promote the survival of lethally irradiated mice when administrated quickly after exposure. We investigated the mechanisms underlying

  11. Radiation carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Fry, R.J.M.

    1976-01-01

    The risk of iatrogenic tumors with radiation therapy is so outweighed by the benefit of cure that estimates of risk have not been considered necessary. However, with the introduction of chemotherapy, combined therapy, and particle radiation therapy, the comparative risks should be examined. In the case of radiation, total dose, fractionation, dose rate, dose distribution, and radiation quality should be considered in the estimation of risk. The biological factors that must be considered include incidence of tumors, latent period, degree of malignancy, and multiplicity of tumors. The risk of radiation induction of tumors is influenced by the genotype, sex, and age of the patient, the tissues that will be exposed, and previous therapy. With chemotherapy the number of cells at risk is usually markedly higher than with radiation therapy. Clearly the problem of the estimation of comparative risks is complex. This paper presents the current views on the comparative risks and the importance of the various factors that influence the estimation of risk.

  12. Quality of Life and Its Related Factors of Radiation Therapy Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ryung Mi; Jung, Won Seok; Oh, Byeong Heon; Jo, Jun Young; Kim, Gi Chul; Choi, Tae Gyu [Dept. of Radiation Oncology, Kyunghee University Medical Center, Seoul (Korea, Republic of); Lee, Sok Goo [Dept. of Preventive Medicine, Chungnam National University College of Medicine, Daejeon (Korea, Republic of)

    2011-03-15

    The purpose of this master's thesis is to utilize basic data in order to improve the quality of life of cancer patients who received radiation therapy after analysing related factors that influence patient's quality of life and obtaining information about physical, mental problems of patients. By using a structured questionnaire about various characteristics and forms of support, I carried out a survey targeting 107 patients that experienced radiation therapy at a university hospital in the Daejeon metropolitan area from July 15 to August 15, 2010 and analysed the factors influencing quality of life. In case of pain due to disease, 65.15 and painless 81.87 showed a high grade quality of life. As body weight decreases, the quality of life become lower. When the grade of quality of life according to economic characteristics was compared, all items except treatment period showed a difference (P=0.000). When the score of social support, family support, medical support and self-esteem was low, the mark of quality of life showed respectively 61.71, 68.77, 71.31, and 69.39 on the basis of 128 points. When the score of support form was high, the mark of quality of life showed 90.47, 83.29, 90.40, and 90.36 (P<0.05). When analyzing the correlation between social support, family support, medical support and self-esteem and the degree of quality of life, social support was 0.768, family support 0.596, medical support 0.434, self-esteem 0.516. They indicated the correlation of meaningful quantity statistically (P<0.01). The factors that improved the quality of life were married state, having a job and painless status. As monthly income increases, the quality of life was also much improved (P<0.05). Among the factors related to quality of life, social support and medical support and higher self-esteem scores of the quality of life score increased 0.979 point, 0.508 points and 1.667 point, respectively. In conclusion, the quality of life of cancer patients that

  13. Improved image quality and radiation dose reduction in liver dynamic CT scan with the protocol change

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yu Jin; Cho, Pyong Kon [Radiological Science, Catholic University of Daegu, Daegu (Korea, Republic of)

    2015-06-15

    The purpose is reducing radiation dose while maintaining of image quality in liver dynamic CT(LDCT) scan, by protocols generally used and the tube voltage set at a low level protocol compared to the radiation dose and image quality. The target is body mass index, 18.5-24 patients out of 40 patients who underwent the ACT(abdominal CT). Group A(tube voltage : 120 kVp, SAFIRE strength 1) of 20 people among 40 people, to apply the general abdominal CT scan protocol, group B(tube voltage : 100 kVp, apply SAFIRE strength 0-5) was 20 people, set a lower tube voltage. Image quality evaluation was setting a region of interest(ROI) in the liver parenchyma, aorta, superior mesenteric artery (SMA), celiac trunk, visceral fat of arterial phase. In the ROI were compared by measuring the noise, signal to noise ratio(SNR), contrast to noise ratio(CNR), CT number. In addition, qualitative assessments to evaluate two people in the rich professional experience in Radiology by 0-3 points. We compared the total radiation dose, dose length product(DLP) and effective dose, volume computed tomography dose index(CTDIvol). The higher SAFIRE in the tube voltage 100 kVp, noise is reduced, CT number was increased. Thus, SNR and CNR was increased higher the SAFIRE step. Compared with the tube voltage 120 kVp, noise, SNR, CNR was most similar in SAFIRE strength 2 and 3. Qualitative assessment SAFIRE strength 2 is the most common SAFIRE strength 2 the most common qualitative assessment, if the tube voltage of 100 kVp when the quality of the images better evaluated was SAFIRE strength 1. Dose was reduced from 21.69%, in 100 kVp than 120 kVp. In the case of a relatively high BMI is not LDCT scan, When it is shipped from the factory tube voltage is set higher, unnecessary radiation exposure when considering the reality that is concerned, when according to the results of this study, set a lower tube voltage and adjust the SAFIRE strength to 1 or 2, the radiation without compromising image quality

  14. Gap Junction Communication and the Propagation of Bystander Effects Induced by Microbeam Irradiation in Human Fibroblast Cultures: The Impact of Radiation Quality

    Science.gov (United States)

    Autsavapromporn, Narongchai; Suzuki, Masao; Funayama, Tomoo; Usami, Noriko; Plante, Ianik; Yokota, Yuichiro; Mutou, Yasuko; Ikeda, Hiroko; Kobayashi, Katsumi; Kobayashi, Yasuhiko; Uchihori, Yukio; Hei, Tom K.; Azzam, Edouard I.; Murakami, Takeshi

    2014-01-01

    Understanding the mechanisms underlying the bystander effects of low doses/low fluences of low- or high-linear energy transfer (LET) radiation is relevant to radiotherapy and radiation protection. Here, we investigated the role of gap-junction intercellular communication (GJIC) in the propagation of stressful effects in confluent normal human fibroblast cultures wherein only 0.036–0.144% of cells in the population were traversed by primary radiation tracks. Confluent cells were exposed to graded doses from monochromatic 5.35 keV X ray (LET ~6 keV/μm), 18.3 MeV/u carbon ion (LET ~103 keV/μm), 13 MeV/u neon ion (LET ~380 keV/μm) or 11.5 MeV/u argon ion (LET ~1,260 keV/μm) microbeams in the presence or absence of 18-α-glycyrrhetinic acid (AGA), an inhibitor of GJIC. After 4 h incubation at 37°C, the cells were subcultured and assayed for micronucleus (MN) formation. Micronuclei were induced in a greater fraction of cells than expected based on the fraction of cells targeted by primary radiation, and the effect occurred in a dose-dependent manner with any of the radiation sources. Interestingly, MN formation for the heavy-ion microbeam irradiation in the absence of AGA was higher than in its presence at high mean absorbed doses. In contrast, there were no significant differences in cell cultures exposed to X-ray microbeam irradiation in presence or absence of AGA. This showed that the inhibition of GJIC depressed the enhancement of MN formation in bystander cells from cultures exposed to high-LET radiation but not low-LET radiation. Bystander cells recipient of growth medium harvested from 5.35 keV X-irradiated cultures experienced stress manifested in the form of excess micronucleus formation. Together, the results support the involvement of both junctional communication and secreted factor(s) in the propagation of radiation-induced stress to bystander cells. They highlight the important role of radiation quality and dose in the observed effects. PMID:23987132

  15. Radiation dose assessment of ACP hot cell in accident

    Energy Technology Data Exchange (ETDEWEB)

    Kook, D. H.; Jeong, W. M.; Koo, J. H.; Jeo, I. J.; Lee, E. P.; Ryu, K. S. [KAERI, Taejon (Korea, Republic of)

    2003-10-01

    The Advanced spent fuel Condition in Process(ACP) is under development for the effective management of spent fuel which had been generated in nuclear plants. The ACP needs a hot cell where most operations will be performed. To give priority to the environments safety, radiation doses evaluations for the radioactive nuclides in accident cases were preliminarily performed with the meteorological data around facility site. Fire accident prevails over several accidnets. Internal Dose and External Dose evaluation according to short dispersion data for that case show a safe margin for regulation limits and SAR limit of IMEF where this facility will be constructed.

  16. Designing a Broadband Pump for High-Quality Micro-Lasers via Modified Net Radiation Method

    Science.gov (United States)

    Nechayev, Sergey; Reusswig, Philip D.; Baldo, Marc A.; Rotschild, Carmel

    2016-12-01

    High-quality micro-lasers are key ingredients in non-linear optics, communication, sensing and low-threshold solar-pumped lasers. However, such micro-lasers exhibit negligible absorption of free-space broadband pump light. Recently, this limitation was lifted by cascade energy transfer, in which the absorption and quality factor are modulated with wavelength, enabling non-resonant pumping of high-quality micro-lasers and solar-pumped laser to operate at record low solar concentration. Here, we present a generic theoretical framework for modeling the absorption, emission and energy transfer of incoherent radiation between cascade sensitizer and laser gain media. Our model is based on linear equations of the modified net radiation method and is therefore robust, fast converging and has low complexity. We apply this formalism to compute the optimal parameters of low-threshold solar-pumped lasers. It is revealed that the interplay between the absorption and self-absorption of such lasers defines the optimal pump absorption below the maximal value, which is in contrast to conventional lasers for which full pump absorption is desired. Numerical results are compared to experimental data on a sensitized Nd3+:YAG cavity, and quantitative agreement with theoretical models is found. Our work modularizes the gain and sensitizing components and paves the way for the optimal design of broadband-pumped high-quality micro-lasers and efficient solar-pumped lasers.

  17. Ionizing radiation induces heritable disruption of epithelial cell interactions

    Science.gov (United States)

    Park, Catherine C.; Henshall-Powell, Rhonda L.; Erickson, Anna C.; Talhouk, Rabih; Parvin, Bahram; Bissell, Mina J.; Barcellos-Hoff, Mary Helen; Chatterjee, A. (Principal Investigator)

    2003-01-01

    Ionizing radiation (IR) is a known human breast carcinogen. Although the mutagenic capacity of IR is widely acknowledged as the basis for its action as a carcinogen, we and others have shown that IR can also induce growth factors and extracellular matrix remodeling. As a consequence, we have proposed that an additional factor contributing to IR carcinogenesis is the potential disruption of critical constraints that are imposed by normal cell interactions. To test this hypothesis, we asked whether IR affected the ability of nonmalignant human mammary epithelial cells (HMEC) to undergo tissue-specific morphogenesis in culture by using confocal microscopy and imaging bioinformatics. We found that irradiated single HMEC gave rise to colonies exhibiting decreased localization of E-cadherin, beta-catenin, and connexin-43, proteins necessary for the establishment of polarity and communication. Severely compromised acinar organization was manifested by the majority of irradiated HMEC progeny as quantified by image analysis. Disrupted cell-cell communication, aberrant cell-extracellular matrix interactions, and loss of tissue-specific architecture observed in the daughters of irradiated HMEC are characteristic of neoplastic progression. These data point to a heritable, nonmutational mechanism whereby IR compromises cell polarity and multicellular organization.

  18. Radiation dose to patients and image quality evaluation from coronary 256-slice computed tomographic angiography

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Liang-Kuang [Department of Radiology, Shin Kong Wu Ho-Su Memorial Hospital, Taiwan (China); College of Medicine, Fu Jen Catholic University, Taiwan (China); Department of Radiological Technology, Yuan Pei University, Taiwan (China); Wu, Tung-Hsin [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, 155 Li-Nong St., Section 2, Taipei 112, Taiwan (China); Yang, Ching-Ching [Department of Radiological Technology, Tzu Chi College of Technology, Hualien, Taiwan (China); Tsai, Chia-Jung [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, 155 Li-Nong St., Section 2, Taipei 112, Taiwan (China); Lee, Jason J.S., E-mail: jslee@ym.edu.t [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, 155 Li-Nong St., Section 2, Taipei 112, Taiwan (China)

    2010-07-21

    The aim of this study is to assess radiation dose and the corresponding image quality from suggested CT protocols which depends on different mean heart rate and high heart rate variability by using 256-slice CT. Fifty consecutive patients referred for a cardiac CT examination were included in this study. All coronary computed tomographic angiography (CCTA) examinations were performed on a 256-slice CT scanner with one of five different protocols: retrospective ECG-gating (RGH) with full dose exposure in all R-R intervals (protocol A), RGH of 30-80% pulsing window with tube current modulation (B), RGH of 78{+-}5% pulsing window with tube current modulation (C), prospective ECG-triggering (PGT) of 78% R-R interval with 5% padding window (D) and PGT of 78% R-R interval without padding window (E). Radiation dose parameters and image quality scoring were determined and compared. In this study, no significant differences were found in comparison on image quality of the five different protocols. Protocol A obtained the highest radiation dose comparing with those of protocols B, C, D and E by a factor of 1.6, 2.4, 2.5 and 4.3, respectively (p<0.001), which were ranged between 2.7 and 11.8 mSv. The PGT could significantly reduce radiation dose delivered to patients, as compared to the RGH. However, the use of PGT has limitations and is only good in assessing cases with lower mean heart rate and stable heart rate variability. With higher mean heart rate and high heart rate variability circumstances, the RGH within 30-80% of R-R interval pulsing window is suggested as a feasible technique for assessing diagnostic performance.

  19. Radiation safety and quality control assurance in X-ray diagnostics 1998; Saeteilyturvallisuus ja laadunvarmistus roentgendiagnostiikassa 1998

    Energy Technology Data Exchange (ETDEWEB)

    Servomaa, A. [ed.

    1998-03-01

    The report is based on a seminar course of lectures `Radiation safety and quality assurance in X-ray diagnostics 1998` organized by the Radiation and Nuclear Safety Authority (STUK) in Finland. The lectures included actual information on X-ray examinations: methods of quality assurance, methods of measuring and calculating patient doses, examination frequencies, patient doses, occupational doses, and radiation risks. Paediatric X-ray examinations and interventional procedures were the most specific topics. The new Council Directive 97/43/Euratom on medical exposure, and the European Guidelines on quality criteria for diagnostic radiographic images, were discussed in several lectures. Lectures on general radiation threats and preparedness, examples of radiation accidents, and emergency preparedness in hospitals were also included. (editor)

  20. SU-E-J-274: Responses of Medulloblastoma Cells to Radiation Dosimetric Parameters in Intensity-Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Park, J [Dept. of Pediatrics, Stanford University School of Medicine, Stanford, CA (United States); Molecular Imaging Program at Stanford, Stanford, CA (United States); Bio-X Program, Stanford, CA (United States); Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul (Korea, Republic of); Park, J [Proton Therapy Center, National Cancer Center, Goyang (Korea, Republic of); Rogalla, S; Contag, C [Dept. of Pediatrics, Stanford University School of Medicine, Stanford, CA (United States); Molecular Imaging Program at Stanford, Stanford, CA (United States); Bio-X Program, Stanford, CA (United States); Woo, D [Asan Institute for Life Sciences, Asan Medical Center, Seoul (Korea, Republic of); Lee, D [Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul (Korea, Republic of); Asan Institute for Life Sciences, Asan Medical Center, Seoul (Korea, Republic of); Park, H [Dept. of Radiation Oncology, Ajou University School of Medicine, Suwon (Korea, Republic of); Suh, T [Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul (Korea, Republic of); Dept. of Biomedical Engineering, The Catholic University of Korea, Seoul (Korea, Republic of)

    2015-06-15

    Purpose: To evaluate radiation responses of the medulloblastoma cell line Daoy in intensity-modulated radiation therapy (IMRT), quantitative variations to variable radiation dosimetic parameters were tracked by bioluminescent images (BLIs). Methods: The luciferase and green fluorescent protein positive Daoy cells were cultured on dishes. The medulloblastoma cells irradiated to different dose rate, interval of fractionated doses, field margin and misalignment, and dose uniformity in IMRT were monitored using bioluminescent images. The cultured cells were placed into a dedicated acrylic phantom to deliver intensity-modulated fluences and calculate accurate predicted dose distribution. The radiation with dose rate from 0.5 Gy/min to 15 Gy/min was irradiated by adjusting monitor unit per minute and source-to-surface distances. The intervals of fractionated dose delivery were changed considering the repair time of double strand breaks (DSB) revealed by straining of gamma-H2AX.The effect of non-uniform doses on the cells were visualized by registering dose distributions and BLIs. The viability according to dosimetric parameters was correlated with bioluminescent intensities for cross-check of radiation responses. Results: The DSB and cell responses due to the first fractionated dose delivery significantly affected final tumor control rather than other parameters. The missing tumor volumes due to the smaller field margin than the tumor periphery or field misalignment caused relapse of cell responses on BLIs. The dose rate and gradient had effect on initial responses but could not bring out the distinguishable killing effect on cancer cells. Conclusion: Visualized and quantified bioluminescent images were useful to correlate the dose distributions with spatial radiation effects on cells. This would derive the effective combination of dose delivery parameters and fractionation. Radiation responses in particular IMRT configuration could be reflected to image based-dose re-optimization.

  1. Adequate image quality with reduced radiation dose in prospectively triggered coronary CTA compared with retrospective techniques

    Energy Technology Data Exchange (ETDEWEB)

    Arnoldi, Elisabeth; Johnson, Thorsten R.; Rist, Carsten; Wintersperger, Bernd J.; Sommer, Wieland H.; Becker, Christoph R.; Reiser, Maximilian F.; Nikolaou, Konstantin [Ludwig-Maximilians University, Department of Clinical Radiology, University Hospitals Munich - Grosshadern Campus, Munich (Germany); Becker, Alexander [Ludwig-Maximilians University, Department of Medicine I, University Hospitals Munich - Grosshadern Campus, Munich (Germany)

    2009-09-15

    The goal of our study was to compare a prospective triggering (PT) CT technique with retrospectively gated (RG) CT techniques in coronary computed tomographic angiograms (CCTA) with respect to image quality and radiation dose. Sixty consecutive patients were enrolled. CCTAs using the RG technique were obtained with a dual-source 64-slice CT system in 40 patients, using ECG-triggered tube current modulation, with either a broad pulsing window at 30-80% of the RR interval (group RGb, 20 patients, heart rate > 70 bpm) or a small pulsing window at 70% (group RGs, 20 patients, heart rate < 70 bpm). The other 20 patients underwent CCTA using the PT technique on a 128-slice CT system (group PT, heart rate < 70 bpm). All images were evaluated by two observers for quality on a three-point scale, with 1 being excellent and 3 being insufficient. The effective radiation dose was calculated for each patient. The average image quality score was 1.5 {+-} 0.6 for PT, 1.35 {+-} 0.5 for RGs and 1.65 {+-} 0.5 for RGb. The mean effective dose for RGb was 9 {+-} 4 mSv, for RGs 7 {+-} 3 mSv and for PT 3 {+-} 1 mSv. This represents a 57% dose reduction for PT compared with RGs and a 67% dose reduction for PT compared with RGb. In conclusion, in selected patients CCTA with the PT technique offers adequate image quality with a significantly lower radiation dose compared with CCTA using RG techniques. (orig.)

  2. Optimization of dose radiation and image quality on computed tomography of thorax in adult women

    Energy Technology Data Exchange (ETDEWEB)

    Cruz Z, G. R.; Casian C, G. [Hospital Juarez de Mexico, Av. IPN No. 5160, 07760 Mexico D. F. (Mexico); Gaona, E.; Franco E, J. G.; Molina F, N., E-mail: gaen1310@correo.xoc.uam.mx [Universidad Autonoma Metropolitana, Unidad Xochimilco, Calz. del Hueso 1100, 04960 Mexico D. F. (Mexico)

    2015-10-15

    Full text: The objective of the study is the optimization of the dose (Dlp) and image quality in the exploration of adult women in studies of thorax with computed tomography (CT). The CT is a technique of exploration with high radiation doses to patients with an increase of the risk factors of developing cancer in the future, but X-rays are a very important medical diagnostic tool. We performed a retrospective survey of 50 female patients who had thorax tomography using the automatic protocol established by the manufacturer, a database of dose (Dlp), measures of patient A P and radiological parameters such as kV and m A was obtained. Subsequently, we carry out the prospective study with 30 patients with prescription of thorax tomography, scans were conducted with CT with reduced doses using manual techniques protocol of exploration while maintaining diagnostic image quality. The results show that the prospective study patients received doses lower than 30% on average. In general the dose patients were within the confidence interval of 95% of the levels of diagnostic reference (DRL) adopted by the European Community for CT and the most common value is 400 Dlp for thorax. Comparative image quality study was conducted using the protocol of the manufacturer and the manual protocol and image quality was diagnostic after dose reduction up to 30%. The reduction of radiation dose in female patients in studies of thorax CT helps to reduce risk factors of developing cancer later in life. A thorax tomography study includes the fibro-glandular tissue of the breast which is very sensitive to stochastic effects of radiation. (Author)

  3. Quality assurance in personal dosimetry of external radiation: present situation and future needs

    Energy Technology Data Exchange (ETDEWEB)

    Ma, N. [Malaysian Institue For Nuclear Technology Research (MINT), Bangi, Selangor (Malaysia)

    2006-07-01

    Whole body personal dosimetry is well established for the individual monitoring of radiation workers. High quality radiation dosimetry is essential for workers who rely upon personal dosemeters to record the amount of radiation to which they are exposed. The mandate has been given to the Personal Dosimetry, (secondary standard dosimetry laboratories) S.S.D.L., (Malaysian institute for nuclear energy research) M.I.N.T. to assure the individual monitoring for radiation workers in Malaysia. In 2005, the S.S.D.L;-M.I.N.T. supply, process and read out of personal dosemeters of nearly 13,000 dosimeters monthly, whereby. 12,000 are films and 1,000 are T.L.D.s. The objective of individual monitoring is not limited to the measurement of doses delivered to individuals, but it should demonstrate that limits of exposure have not been exceeded and that working conditions have not unexpectedly deteriorated. Dosimetry measurements are an important component of radiation protection programs and must be of high quality. The exposure of workers to radiation must be controlled and monitored in order to comply with regulatory requirements. S.S.D.L.-M.I.N.T; demonstrates that its performance is at an acceptable level by implementing overall system performance, as evidenced by the ISO 9001 certification of the Personal Dosimetry Service in 2002 and ISO/I.E.C. 17025 accreditation to the calibration laboratory in 2004. The certification and accreditation processes achieved the goal by formalizing the recognition of satisfactory performance, and providing evidence of this performance. Overall performances are assessed, personnel operating the system will be trained and are well qualified and all actions will be documented. The paper describes the overview of the Q.M.S. carried out at the S.S. D.L.-M.I.N.T.. During the implementation of Q.M.S. a few areas has been identified for future consideration. These include performance specification and type testing of dosemeters, which provide a

  4. Blood cell labelling. Theory and methods: radiation hazards.

    Science.gov (United States)

    Trott, N G; Akbari, R B

    1984-02-03

    The chief physical properties of the radionuclide In111 are outlined, and compared with those of three other radionuclides, Tc99m, I131 and Cr51 which have similar applications. It is pointed out that the gamma-rays of In111 are appreciably more penetrating in lead than those of Tc99m and the significance of this, both in the use of shielding on syringes and in the effectiveness of lead glass screens is discussed. Examples are given of the dosimetry for In111 labelled cells in humans and it is noted that the absorbed dose in the spleen per mCi (37 MBq) injected may be some 10 rad (0.1 Gy). The problems that have been noted of damage to cells arising from oxine labelling and now considered to be due to radiation damage are briefly reviewed.

  5. Improved postharvest quality in patagonian squash (Cucurbita moschata) coated with radiation depolymerized chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, Maria Alicia; Goitia, Maria Teresa [Laboratorio de Investigaciones Basicas Aplicadas en Quitina, Departamento de Quimica, Universidad Nacional del Sur. Avenida Alem 1253, B8000CPB Bahia Blanca (Argentina); Yossen, Mariana [Instituto de Desarrollo Tecnologico para la Industria Quimica (INTEC), CONICET-Universidad Nacional del Litoral, Ruta Nacional 168-Paraje ' El Pozo' , 3000 Santa Fe (Argentina); Cifone, Norma; Agullo, Enrique [Laboratorio de Investigaciones Basicas Aplicadas en Quitina, Departamento de Quimica, Universidad Nacional del Sur. Avenida Alem 1253, B8000CPB Bahia Blanca (Argentina); Andreucetti, Noemi, E-mail: andreuce@criba.edu.ar [Laboratorio de Radioisotopos, Departamento de Quimica, Universidad Nacional del Sur, Avenida Alem 1253, B8000CPB Bahia Blanca (Argentina)

    2011-12-15

    Different molecular weight chitosans were evaluated on the decay of coated Anquito squashes (Cucurbita moschata) as well as the maintenance of the fruit quality along five storage months. The original chitosan (Mw=391 kDa, 83% DD), was depolymerized by gamma radiation. Apart from chain scission, other chemical changes were not detected by FTIR or UV-vis analyses. The molecular weight characterization of chitosans was done by size exclusion chromatography with dual light scattering and concentration detection (SEC-MALLS-RI). The coating effectiveness was evaluated on the following parameters: fungal decay incidence, weight loss, firmness, total reducing sugar, soluble solid, flesh color, carotene content, pH and titratable acidity. No sign of fungal decay was observed in squashes coated with 122 and 56 kDa chitosans, which were also the most effective treatments in reducing the weight loss. The chitosan with Mw=122 kDa was also the best treatment considering firmness, internal aspect, sugar and carotene content. Then, radiation degraded chitosan was better in C. moschata preservation than the original chitosan. - Highlights: > Original Chitosan was radiation depolymerized producing chitosans with lower molecular weights. > Gamma-irradiated chitosans only exhibit chain scission. > SEC-MALLS-RI chromatography is a useful tool in molecular weight analysis. > Depolymerized chitosans were the best in maintaining the quality and the storage life of coated squashes.

  6. Silicon space solar cells: progression and radiation-resistance analysis

    Science.gov (United States)

    Rehman, Atteq ur; Lee, Sang Hee; Lee, Soo Hong

    2016-02-01

    In this paper, an overview of the solar cell technology based on silicon for applications in space is presented. First, the space environment and its effects on the basis of satellite orbits, such as geostationary earth orbit (GEO) and low earth orbit (LEO), are described. The space solar cell technology based on silicon-based materials, including thin-film silicon solar cells, for use in space was appraised. The evolution of the design for silicon solar cell for use in space, such as a backsurface field (BSF), selective doping, and both-side passivation, etc., is illustrated. This paper also describes the nature of radiation-induced defects and the models proposed for understanding the output power degradation in silicon space solar cells. The phenomenon of an anomalous increase in the short-circuit current ( I sc) in the fluence irradiation range from 2 × 1016 cm-2 to 5 × 1016 cm-2 is also described explicitly from the view point of the various presented models.

  7. Invasive oral cancer stem cells display resistance to ionising radiation.

    Science.gov (United States)

    Gemenetzidis, Emilios; Gammon, Luke; Biddle, Adrian; Emich, Helena; Mackenzie, Ian C

    2015-12-22

    There is a significant amount of evidence to suggest that human tumors are driven and maintained by a sub-population of cells, known as cancer stem cells (CSC). In the case of head and neck cancer, such cells have been characterised by high expression levels of CD44 cell surface glycoprotein, while we have previously shown the presence of two diverse oral CSC populations in vitro, with different capacities for cell migration and proliferation. Here, we examined the response of oral CSC populations to ionising radiation (IR), a front-line measure for the treatment of head and neck tumors. We show that oral CSC initially display resistance to IR-induced growth arrest as well as relative apoptotic resistance. We propose that this is a result of preferential activation of the DNA damagerepair pathway in oral CSC with increased activation of ATM and BRCA1, elevated levels of DNA repair proteins RAD52, XLF, and a significantly faster rate of DNA double-strand-breaks clearance 24 hours following IR. By visually identifying CSC sub-populations undergoing EMT, we show that EMT-CSC represent the majority of invasive cells, and are more radio-resistant than any other population in re-constructed 3D tissues. We provide evidence that IR is not sufficient to eliminate CSC in vitro, and that sensitization of CD44hi/ESAlow cells to IR, followed by secondary EMT blockade, could be critical in order to reduce primary tumor recurrence, but more importantly to be able to eradicate cells capable of invasion and distant metastasis.

  8. Quality Factor and Radiation Efficiency of Dual-Mode Self-Resonant Spherical Antennas With Lossy Magnetodielectric Cores

    DEFF Research Database (Denmark)

    Hansen, Troels Vejle; Kim, Oleksiy S.; Breinbjerg, Olav

    2014-01-01

    For spherical antennas consisting of a solid magnetodielectric lossy core with an impressed surface current density exciting a superposition of the ${\\rm TE}_{mn}$ and ${\\rm TM}_{mn}$ spherical modes, we analytically determine the radiation quality factor $Q$ and radiation efficiency $e$ . Also, we...

  9. Mechanisms of Low Dose Radiation-induced T helper Cell Function

    Energy Technology Data Exchange (ETDEWEB)

    Gridley, Daila S.

    2008-10-31

    photons. Over the course of this research, tissues other than spleens were archived and with funding obtained from other sources, including the Department of Radiation Medicine at the Loma Linda University Medical Center, some additional assays were performed. Furthermore, groups of additional mice were included that were pre-exposed to low-dose photons before irradiating with acute photons, protons, and simulated solar particle event (SPE) protons. Hence, the original support together with the additional funding for our research led to generation of much valuable information that was originally not anticipated. Some of the data has already resulted in published articles, manuscripts in review, and a number of presentations at scientific conferences and workshops. Difficulties in reliable and reproducible quantification of secreted cytokines using multi-plex technology delayed completion of this study for a period of time. However, final analyses of the remaining data are currently being performed and should result in additional publications and presentations in the near future. Some of the most notable conclusions, thus far, are briefly summarized below: - Distribution of leukocytes were dependent upon cell type, radiation quality, body compartment analyzed, and time after exposure. Low-dose protons tended to have less effect on numbers of major leukocyte populations and T cell subsets compared to low-dose photons. - The patterns of gene and cytokine expression in CD4+ T cells after protracted low-dose irradiation were significantly modified and highly dependent upon the total dose and time after exposure. - Patterns of gene and cytokine expression differed substantially among groups exposed to low-dose photons versus low-dose protons; differences were also noted among groups exposed to much higher doses of photons, protons, and simulated SPE protons. - Some measurements indicated that exposure to low-dose photon radiation, especially 0.01 Gy, significantly

  10. Quality of Intensity Modulated Radiation Therapy Treatment Plans Using a {sup 60}Co Magnetic Resonance Image Guidance Radiation Therapy System

    Energy Technology Data Exchange (ETDEWEB)

    Wooten, H. Omar, E-mail: hwooten@radonc.wustl.edu; Green, Olga; Yang, Min; DeWees, Todd; Kashani, Rojano; Olsen, Jeff; Michalski, Jeff; Yang, Deshan; Tanderup, Kari; Hu, Yanle; Li, H. Harold; Mutic, Sasa

    2015-07-15

    Purpose: This work describes a commercial treatment planning system, its technical features, and its capabilities for creating {sup 60}Co intensity modulated radiation therapy (IMRT) treatment plans for a magnetic resonance image guidance radiation therapy (MR-IGRT) system. Methods and Materials: The ViewRay treatment planning system (Oakwood Village, OH) was used to create {sup 60}Co IMRT treatment plans for 33 cancer patients with disease in the abdominal, pelvic, thorax, and head and neck regions using physician-specified patient-specific target coverage and organ at risk (OAR) objectives. Backup plans using a third-party linear accelerator (linac)-based planning system were also created. Plans were evaluated by attending physicians and approved for treatment. The {sup 60}Co and linac plans were compared by evaluating conformity numbers (CN) with 100% and 95% of prescription reference doses and heterogeneity indices (HI) for planning target volumes (PTVs) and maximum, mean, and dose-volume histogram (DVH) values for OARs. Results: All {sup 60}Co IMRT plans achieved PTV coverage and OAR sparing that were similar to linac plans. PTV conformity for {sup 60}Co was within <1% and 3% of linac plans for 100% and 95% prescription reference isodoses, respectively, and heterogeneity was on average 4% greater. Comparisons of OAR mean dose showed generally better sparing with linac plans in the low-dose range <20 Gy, but comparable sparing for organs with mean doses >20 Gy. The mean doses for all {sup 60}Co plan OARs were within clinical tolerances. Conclusions: A commercial {sup 60}Co MR-IGRT device can produce highly conformal IMRT treatment plans similar in quality to linac IMRT for a variety of disease sites. Additional work is in progress to evaluate the clinical benefit of other novel features of this MR-IGRT system.

  11. SU-E-T-581: On the Value of LET as a Radiation Quality Descriptor for RBE

    Energy Technology Data Exchange (ETDEWEB)

    Pater, P; Backstrom, G; Enger, S; Seuntjens, J; Naqa, I El [McGill University, Montreal, Quebec (Canada); Villegas, F; Ahnesjo, A [Uppsala University, Uppsala (Sweden)

    2015-06-15

    Purpose: To investigate the relationship between linear energy transfer (LET) and relative biological effectiveness (RBE) for protons and light ions, and the corresponding role of LET as a descriptor of radiation quality of hadron therapy. Methods: Monte Carlo (MC) proton and light ion (He, Li, C) tracks with LET < 30 eV nm{sup -1} were generated in an event-by-event mode. They were overlaid on a cell nucleus model containing 6×10{sup 9} nucleotide base pairs using an isotropic irradiation procedure that provides electronic equilibrium. Strand breaks (sbs) were scored in the DNA sugar-phosphate groups and further sub-classified into single or double sbs (ssbs or dsbs). Distributions of ssbs and dsbs for 2 Gy fractions were calculated to estimate RBE for the induction of initial dsbs with reference to {sup 60}Co. Additionally, sbs were classified based on their complexity (i.e. the number of sbs in each cluster). Results: An increase in LET for light ions of the same atomic number or a decrease in atomic number for ions of the same LET resulted in a lower kinetic energy of emitted secondary electrons. The clustering of DNA damage was more pronounced as reflected by the increase in proton RBE from ∼ 1.75 to 4 for LET values of 7 to 28 eV nm{sup -1}. A significant RBE decrease between protons, He, Li and C ions of the same LET was also noticed as function of the atomic number. Significant differences in ssbs and dsbs complexities were also seen for particles with the same LET, potentially supporting a clustering-based radiation quality descriptor. Conclusion: The LET-RBE relationships were simulated for proton and light ions and exhibited expected trends, including different RBEs for particles with the same LET but different atomic numbers. A complexity based radiation quality descriptor may allow better differentiation of RBE between radiation fields of similar LET. We would like to acknowledge support from the Fonds de recherche du Quebec Sante (FRQS), from the

  12. Effects of ionizing radiation on bone cell differentiation in an experimental murine bone cell model

    Science.gov (United States)

    Baumstark-Khan, Christa; Lau, Patrick; Hellweg, Christine; Reitz, Guenther

    During long-term space travel astronauts are exposed to a complex mixture of different radiation types under conditions of dramatically reduced weight-bearing activity. It has been validated that astronauts loose a considerable amount of bone mass at a rate up to one to two percent each month in space. Therapeutic doses of ionizing radiation cause bone damage and increase fracture risks after treatment for head-and-neck cancer and in pelvic irradiation. For low radiation doses, the possibility of a disturbed healing potential of bone was described. Radiation induced damage has been discussed to inflict mainly on immature and healing bone. Little is known about radiation effects on bone remodelling and even less on the combined action of microgravity and radiation. Bone remodelling is a life-long process performed by balanced action of cells from the osteoblast and osteoclast lineages. While osteoblasts differentiate either into bone-lining cells or into osteocytes and play a crucial role in bone matrix synthesis, osteoclasts are responsible for bone resorption. We hypothesize that the balance between bone matrix assembly by osteocytes and bone degradation by osteoclasts is modulated by microgravity as well as by ionizing radiation. To address this, a cell model consisting of murine cell lines with the potential to differentiate into bone-forming osteoblasts (OCT-1, MC3T3-E1 S24, and MC3T3-E1 S4) was used for studying radiation response after exposure to simulated components of cosmic radiation. Cells were exposed to graded doses of 150 kV X-rays, α particles (0.525 MeV/u, 160 keV/µm; PTB, Braunschweig, Germany) and accelerated heavy ions (75 MeV/u carbon, 29 keV/µm; 95 MeV/u argon, 230 keV/µm; GANIL, Caen, France). Cell survival was measured as colony forming ability; cell cycle progression was analyzed via fluorescence-activated cell scanning (FACS) by measurement of the content of propidium iodide-stained DNA, DNA damage was visualized by γH2AX

  13. Designing a Broadband Pump for High-Quality Micro-Lasers via Modified Net Radiation Method

    CERN Document Server

    Nechayev, Sergey; Baldo, Marc A; Rotschild, Carmel

    2016-01-01

    High-quality micro-lasers are key ingredients in non-linear optics, communication, sensing and low-threshold solar-pumped lasers. However, such micro-lasers exhibit negligible absorption of free-space broadband pump light. Recently, this limitation was lifted by cascade energy transfer, in which the absorption and quality factor are modulated with wavelength, enabling non-resonant pumping of high-quality micro-lasers and solar-pumped laser to operate at record low solar concentration. Here, we present a generic theoretical framework for modeling the absorption, emission and energy transfer of incoherent radiation between cascade sensitizer and laser gain media. Our model is based on linear equations of the modified net radiation method and is therefore robust, fast converging and has low complexity. We apply this formalism to compute the optimal parameters of low-threshold solar-pumped lasers. It is revealed that the interplay between the absorption and self-absorption of such lasers defines the optimal pump ...

  14. Effect of ionizing radiation on the physical biology of head and neck squamous cell carcinoma cells.

    Science.gov (United States)

    Baker-Groberg, Sandra M; Bornstein, Sophia; Zilberman-Rudenko, Jevgenia; Schmidt, Mark; Tormoen, Garth W; Kernan, Casey; Thomas, Charles R; Wong, Melissa H; Phillips, Kevin G; McCarty, Owen J T

    2015-09-01

    Head and neck squamous cell carcinoma (HNSCC) is the sixth leading cause of cancer worldwide. Although there are numerous treatment options for HNSCC, such as surgery, cytotoxic chemotherapy, molecularly targeted systemic therapeutics, and radiotherapy, overall survival has not significantly improved in the last 50 years. This suggests a need for a better understanding of how these cancer cells respond to current treatments in order to improve treatment paradigms. Ionizing radiation (IR) promotes cancer cell death through the creation of cytotoxic DNA lesions, including single strand breaks, base damage, crosslinks, and double strand breaks (DSBs). As unrepaired DSBs are the most cytotoxic DNA lesion, defining the downstream cellular responses to DSBs are critical for understanding the mechanisms of tumor cell responses to IR. The effects of experimental IR on HNSCC cells beyond DNA damage in vitro are ill-defined. Here we combined label-free, quantitative phase and fluorescent microscopy to define the effects of IR on the dry mass and volume of the HNSCC cell line, UM-SCC-22A. We quantified nuclear and cytoplasmic subcellular density alterations resulting from 8 Gy X-ray IR and correlated these signatures with DNA and γ-H2AX expression patterns. This study utilizes a synergistic imaging approach to study both biophysical and biochemical alterations in cells following radiation damage and will aid in future understanding of cellular responses to radiation therapy.

  15. Curcumin Sensitizes Hepatocellular Carcinoma Cells to Radiation via Suppression of Radiation-Induced NF-κB Activity

    Directory of Open Access Journals (Sweden)

    Fei-Ting Hsu

    2015-01-01

    Full Text Available The effects and possible underlying mechanism of curcumin combined with radiation in human hepatocellular carcinoma (HCC cells in vitro were evaluated. The effects of curcumin, radiation, and combination of both on cell viability, apoptosis, NF-κB activation, and expressions of NF-κB downstream effector proteins were investigated with 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT, NF-κB reporter gene, mitochondrial membrane potential (MMP, electrophoretic mobility shift (EMSA, and Western blot assays in Huh7-NF-κB-luc2, Hep3B, and HepG2 cells. Effect of I kappa B alpha mutant (IκBαM vector, a specific inhibitor of NF-κB activation, on radiation-induced loss of MMP was also evaluated. Results show that curcumin not only significantly enhances radiation-induced cytotoxicity and depletion of MMP but inhibits radiation-induced NF-κB activity and expressions of NF-κB downstream proteins in HCC cells. IκBαM vector also shows similar effects. In conclusion, we suggest that curcumin augments anticancer effects of radiation via the suppression of NF-κB activation.

  16. The Correlation between Cell Phone Use and Sleep Quality in Medical Students

    Directory of Open Access Journals (Sweden)

    Mohamad Reza Bayatiani

    2016-03-01

    Full Text Available Introduction The negative health effects of electromagnetic radiation and psychological dependence are among the major consequences of widespread cell phone use in the general population, especially among adolescents. In this study, the relationship between cell phone use and sleep quality parameters was evaluated. Materials and Methods The study sample consisted of 820 students (305 males and 515 females, recruited from Arak University of Medical Sciences, Arak, Iran. The participants completed Pittsburgh Sleep Quality Index (PSQI and Cell-phone Overuse Scale (COS; the validity of these questionnaires had been previously confirmed in the Iranian population. Information on demographic characteristics and variables associated with cell phone exposure, such as the frequency and duration of phone calls and number of messages was collected in a separate questionnaire. Results Data analysis showed that cell phone overuse was significantly correlated with sleep quality and its components. Moreover, the results indicated that the global PSQI score and some sleep components were significantly correlated with several variables related to cell phone use. Based on the findings, the mean PSQI score was significantly different among heavy and light cell phone users (P

  17. Effects of Chronic Low-Dose Radiation on Human Neural Progenitor Cells

    Science.gov (United States)

    Katsura, Mari; Cyou-Nakamine, Hiromasa; Zen, Qin; Zen, Yang; Nansai, Hiroko; Amagasa, Shota; Kanki, Yasuharu; Inoue, Tsuyoshi; Kaneki, Kiyomi; Taguchi, Akashi; Kobayashi, Mika; Kaji, Toshiyuki; Kodama, Tatsuhiko; Miyagawa, Kiyoshi; Wada, Youichiro; Akimitsu, Nobuyoshi; Sone, Hideko

    2016-01-01

    The effects of chronic low-dose radiation on human health have not been well established. Recent studies have revealed that neural progenitor cells are present not only in the fetal brain but also in the adult brain. Since immature cells are generally more radiosensitive, here we investigated the effects of chronic low-dose radiation on cultured human neural progenitor cells (hNPCs) derived from embryonic stem cells. Radiation at low doses of 31, 124 and 496 mGy per 72 h was administered to hNPCs. The effects were estimated by gene expression profiling with microarray analysis as well as morphological analysis. Gene expression was dose-dependently changed by radiation. By thirty-one mGy of radiation, inflammatory pathways involving interferon signaling and cell junctions were altered. DNA repair and cell adhesion molecules were affected by 124 mGy of radiation while DNA synthesis, apoptosis, metabolism, and neural differentiation were all affected by 496 mGy of radiation. These in vitro results suggest that 496 mGy radiation affects the development of neuronal progenitor cells while altered gene expression was observed at a radiation dose lower than 100 mGy. This study would contribute to the elucidation of the clinical and subclinical phenotypes of impaired neuronal development induced by chronic low-dose radiation.

  18. Effects of Chronic Low-Dose Radiation on Human Neural Progenitor Cells

    Science.gov (United States)

    Katsura, Mari; Cyou-Nakamine, Hiromasa; Zen, Qin; Zen, Yang; Nansai, Hiroko; Amagasa, Shota; Kanki, Yasuharu; Inoue, Tsuyoshi; Kaneki, Kiyomi; Taguchi, Akashi; Kobayashi, Mika; Kaji, Toshiyuki; Kodama, Tatsuhiko; Miyagawa, Kiyoshi; Wada, Youichiro; Akimitsu, Nobuyoshi; Sone, Hideko

    2016-01-01

    The effects of chronic low-dose radiation on human health have not been well established. Recent studies have revealed that neural progenitor cells are present not only in the fetal brain but also in the adult brain. Since immature cells are generally more radiosensitive, here we investigated the effects of chronic low-dose radiation on cultured human neural progenitor cells (hNPCs) derived from embryonic stem cells. Radiation at low doses of 31, 124 and 496 mGy per 72 h was administered to hNPCs. The effects were estimated by gene expression profiling with microarray analysis as well as morphological analysis. Gene expression was dose-dependently changed by radiation. By thirty-one mGy of radiation, inflammatory pathways involving interferon signaling and cell junctions were altered. DNA repair and cell adhesion molecules were affected by 124 mGy of radiation while DNA synthesis, apoptosis, metabolism, and neural differentiation were all affected by 496 mGy of radiation. These in vitro results suggest that 496 mGy radiation affects the development of neuronal progenitor cells while altered gene expression was observed at a radiation dose lower than 100 mGy. This study would contribute to the elucidation of the clinical and subclinical phenotypes of impaired neuronal development induced by chronic low-dose radiation. PMID:26795421

  19. Hydroxyurea and sickle cell anemia: effect on quality of life

    OpenAIRE

    Pegelow Charles H; Eckman James R; Swerdlow Paul; Waclawiw Myron A; Barton Franca B; Ballas Samir K; Koshy Mabel; Barton Bruce A; Bonds Duane R

    2006-01-01

    Abstract Background The Multicenter Study of Hydroxyurea (HU) in Sickle Cell Anemia (MSH) previously showed that daily oral HU reduces painful sickle cell (SS) crises by 50% in patients with moderate to severe disease. The morbidity associated with this disease is known to have serious negative impact on the overall quality of life(QOL) of affected individuals. Methods The data in this report were collected from the 299 patients enrolled in the MSH. Health quality of llife (HQOL) measures wer...

  20. Explicit and convex optimization of plan quality measures in intensity-modulated radiation therapy treatment planning

    CERN Document Server

    Engberg, Lovisa; Forsgren, Anders; Hårdemark, Björn

    2016-01-01

    Given the widespread agreement that doses-at-volume play important roles in quality assessment of radiation therapy treatment plans, planning objectives that correlate well with explicit dose-at-volume optimization are likely to correlate well with plan quality. In this study, planning objectives are formulated to explicitly either minimize or maximize convex approximations of dose-at-volume, namely, mean-tail-doses. This is in contrast to the conventionally used planning objectives, which are used to maximize clinical goal fulfilment by relating to deviations from dose-at-volume thresholds. Advantages of the proposed planning objectives are investigated through juxtaposition with conventional objectives in a computational study of two patient cases, each with three doses-at-volume to be minimized subject to PTV coverage. With proposed planning objectives, this is translated into minimizing three mean-tail-doses. Comparison with conventional objectives is carried out in the dose-at-volume domain and in the no...

  1. Radiation damage and repair in cells and cell components. Progress report, November 1, 1977--October 31, 1978. [Uv and x radiation, bacteriophages

    Energy Technology Data Exchange (ETDEWEB)

    Fluke, D.J.; Pollard, E.C.

    1978-01-01

    Progress is reported on the following research projects: coordinate induction of mutagenesis, radioresistance, and inhibition of post-radiation DNA degradation; radioinduced filamentation; action spectrum for induction of K12 lambda phage; effects of uv radiation on cells in the frozen state; dependence of mutagenesis on wavelength of uv; and w-reactivation of x-irradiated phage lambda. (HLW)

  2. Stereotactic body radiation therapy versus conventional radiation therapy in patients with early stage non-small cell lung cancer

    DEFF Research Database (Denmark)

    Jeppesen, Stefan Starup; Schytte, Tine; Jensen, Henrik R;

    2013-01-01

    Abstract Introduction. Stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) is now an accepted and patient friendly treatment, but still controversy exists about its comparability to conventional radiation therapy (RT). The purpose of this single...... and SBRT predicted improved prognosis. However, staging procedure, confirmation procedure of recurrence and technical improvements of radiation treatment is likely to influence outcomes. However, SBRT seems to be as efficient as conventional RT and is a more convenient treatment for the patients....

  3. Epicatechin stimulates mitochondrial activity and selectively sensitizes cancer cells to radiation.

    Directory of Open Access Journals (Sweden)

    Hosam A Elbaz

    Full Text Available Radiotherapy is the treatment of choice for solid tumors including pancreatic cancer, but the effectiveness of treatment is limited by radiation resistance. Resistance to chemotherapy or radiotherapy is associated with reduced mitochondrial respiration and drugs that stimulate mitochondrial respiration may decrease radiation resistance. The objectives of this study were to evaluate the potential of (--epicatechin to stimulate mitochondrial respiration in cancer cells and to selectively sensitize cancer cells to radiation. We investigated the natural compound (--epicatechin for effects on mitochondrial respiration and radiation resistance of pancreatic and glioblastoma cancer cells using a Clark type oxygen electrode, clonogenic survival assays, and Western blot analyses. (--Epicatechin stimulated mitochondrial respiration and oxygen consumption in Panc-1 cells. Human normal fibroblasts were not affected. (--Epicatechin sensitized Panc-1, U87, and MIA PaCa-2 cells with an average radiation enhancement factor (REF of 1.7, 1.5, and 1.2, respectively. (--Epicatechin did not sensitize normal fibroblast cells to ionizing radiation with a REF of 0.9, suggesting cancer cell selectivity. (--Epicatechin enhanced Chk2 phosphorylation and p21 induction when combined with radiation in cancer, but not normal, cells. Taken together, (--epicatechin radiosensitized cancer cells, but not normal cells, and may be a promising candidate for pancreatic cancer treatment when combined with radiation.

  4. Energy loss process analysis for radiation degradation and immediate recovery of amorphous silicon alloy solar cells

    Science.gov (United States)

    Sato, Shin-ichiro; Beernink, Kevin; Ohshima, Takeshi

    2015-06-01

    Performance degradation of a-Si/a-SiGe/a-SiGe triple-junction solar cells due to irradiation of silicon ions, electrons, and protons are investigated using an in-situ current-voltage measurement system. The performance recovery immediately after irradiation is also investigated. Significant recovery is always observed independent of radiation species and temperature. It is shown that the characteristic time, which is obtained by analyzing the short-circuit current annealing behavior, is an important parameter for practical applications in space. In addition, the radiation degradation mechanism is discussed by analyzing the energy loss process of incident particles (ionizing energy loss: IEL, and non-ionizing energy loss: NIEL) and their relative damage factors. It is determined that ionizing dose is the primarily parameter for electron degradation whereas displacement damage dose is the primarily parameter for proton degradation. This is because the ratio of NIEL to IEL in the case of electrons is small enough to be ignored the damage due to NIEL although the defect creation ratio of NIEL is much larger than that of IEL in the cases of both protons and electrons. The impact of “radiation quality effect” has to be considered to understand the degradation due to Si ion irradiation.

  5. Imaging and radiation effects of gold nanoparticles in tumour cells

    Science.gov (United States)

    McQuaid, Harold N.; Muir, Mark F.; Taggart, Laura E.; McMahon, Stephen J.; Coulter, Jonathan A.; Hyland, Wendy B.; Jain, Suneil; Butterworth, Karl T.; Schettino, Giuseppe; Prise, Kevin M.; Hirst, David G.; Botchway, Stanley W.; Currell, Fred J.

    2016-01-01

    Gold nanoparticle radiosensitization represents a novel technique in enhancement of ionising radiation dose and its effect on biological systems. Variation between theoretical predictions and experimental measurement is significant enough that the mechanism leading to an increase in cell killing and DNA damage is still not clear. We present the first experimental results that take into account both the measured biodistribution of gold nanoparticles at the cellular level and the range of the product electrons responsible for energy deposition. Combining synchrotron-generated monoenergetic X-rays, intracellular gold particle imaging and DNA damage assays, has enabled a DNA damage model to be generated that includes the production of intermediate electrons. We can therefore show for the first time good agreement between the prediction of biological outcomes from both the Local Effect Model and a DNA damage model with experimentally observed cell killing and DNA damage induction via the combination of X-rays and GNPs. However, the requirement of two distinct models as indicated by this mechanistic study, one for short-term DNA damage and another for cell survival, indicates that, at least for nanoparticle enhancement, it is not safe to equate the lethal lesions invoked in the local effect model with DNA damage events.

  6. Research on a laser ultrasound method for testing the quality of a nuclear radiation protection structure

    Science.gov (United States)

    Zhang, Kuanshuang; Zhou, Zhenggan; Ma, Liyin

    2017-02-01

    Laser ultrasonics has been investigated for inspecting the quality of a nuclear radiation protection structure. A possibility is proposed to improve the signal to noise ratio (SNR) of a laser ultrasonic inspection system. Then, a nuclear radiation protection structure composed of an AISI 1045 steel sheet connected with a lead alloy sheet by using an epoxy resin adhesive was manufactured with simulated defects. A non-contact laser ultrasonic inspection system, where the measured signals were filtered using a wavelet threshold de-noising method, was established to conduct a series of experiments. The proposed signal processing method can significantly improve the SNR of measured laser ultrasound signals on a rough solid surface. Compared with the SNR of original ultrasonic signals measured in transmission and reflection, the SNR of processed transmitted and reflected signals is improved by 13.8 and 16.6 dB, respectively. Moreover, laser ultrasonic C-scans based on the transmission and pulse-echo method can detect the simulated de-bonding defects, and the relative deviation between the measured sizes and design values is below 9%. Therefore, the laser ultrasonic method combined with effective signal processing can achieve the quantitative characterization of de-bonding defects in nuclear radiation protection structures.

  7. Does Quality of Radiation Therapy Predict Outcomes of Multicenter Cooperative Group Trials? A Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Fairchild, Alysa, E-mail: alysa.fairchild@albertahealthservices.ca [Department of Radiation Oncology, Cross Cancer Institute, Edmonton, Alberta (Canada); Straube, William [Advanced Technology Consortium, Imaged-Guided Therapy QA Center, St. Louis, Missouri (United States); Laurie, Fran [Quality Assurance Review Center, Lincoln, Rhode Island (United States); Followill, David [Radiological Physics Center, University of Texas MD Anderson Cancer Centre, Houston, Texas (United States)

    2013-10-01

    Central review of radiation therapy (RT) delivery within multicenter clinical trials was initiated in the early 1970s in the United States. Early quality assurance publications often focused on metrics related to process, logistics, and timing. Our objective was to review the available evidence supporting correlation of RT quality with clinical outcomes within cooperative group trials. A MEDLINE search was performed to identify multicenter studies that described central subjective assessment of RT protocol compliance (quality). Data abstracted included method of central review, definition of deviations, and clinical outcomes. Seventeen multicenter studies (1980-2012) were identified, plus one Patterns of Care Study. Disease sites were hematologic, head and neck, lung, breast, and pancreas. Between 0 and 97% of treatment plans received an overall grade of acceptable. In 7 trials, failure rates were significantly higher after inadequate versus adequate RT. Five of 9 and 2 of 5 trials reported significantly worse overall and progression-free survival after poor-quality RT, respectively. One reported a significant correlation, and 2 reported nonsignificant trends toward increased toxicity with noncompliant RT. Although more data are required, protocol-compliant RT may decrease failure rates and increase overall survival and likely contributes to the ability of collected data to answer the central trial question.

  8. The peer review system (PRS) for quality assurance and treatment improvement in radiation therapy

    Science.gov (United States)

    Le, Anh H. T.; Kapoor, Rishabh; Palta, Jatinder R.

    2012-02-01

    Peer reviews are needed across all disciplines of medicine to address complex medical challenges in disease care, medical safety, insurance coverage handling, and public safety. Radiation therapy utilizes technologically advanced imaging for treatment planning, often with excellent efficacy. Since planning data requirements are substantial, patients are at risk for repeat diagnostic procedures or suboptimal therapeutic intervention due to a lack of knowledge regarding previous treatments. The Peer Review System (PRS) will make this critical radiation therapy information readily available on demand via Web technology. The PRS system has been developed with current Web technology, .NET framework, and in-house DICOM library. With the advantages of Web server-client architecture, including IIS web server, SOAP Web Services and Silverlight for the client side, the patient data can be visualized through web browser and distributed across multiple locations by the local area network and Internet. This PRS will significantly improve the quality, safety, and accessibility, of treatment plans in cancer therapy. Furthermore, the secure Web-based PRS with DICOM-RT compliance will provide flexible utilities for organization, sorting, and retrieval of imaging studies and treatment plans to optimize the patient treatment and ultimately improve patient safety and treatment quality.

  9. Quality assurance for radon exposure chambers at the National Air and Radiation Environmental Laboratory, Montgomery, Alabama

    Energy Technology Data Exchange (ETDEWEB)

    Semler, M.O.; Sensintaffar, E.L. [National Air and Radiation Environmental Laboratory, Montgomery, AL (United States)

    1993-12-31

    The Office of Radiation and Indoor Air, U.S. Environmental Protection Agency (EPA), operates six radon exposure chambers in its two laboratories, the National Air and Radiation Environmental Laboratory (NAREL) in Montgomery, Alabama, and the Las Vegas Facility, Las Vegas, Nevada. These radon exposure chambers are used to calibrate and test portable radon measuring instruments, test commercial suppliers of radon measurement services through the Radon Measurement Proficiency Program, and expose passive measurement devices to known radon concentrations as part of a quality assurance plan for federal and state studies measuring indoor radon concentrations. Both laboratories participate in national and international intercomparisons for the measurement of radon and are presently working with the National Institute of Standards and Technology (NIST) to receive a certificate of traceability for radon measurements. NAREL has developed an estimate of the total error in its calibration of each chamber`s continuous monitors as part of an internal quality assurance program. This paper discusses the continuous monitors and their calibration for the three chambers located in Montgomery, Alabama, as well as the results of the authors intercomparisons and total error analysis.

  10. Global Harmonization of Quality Assurance Naming Conventions in Radiation Therapy Clinical Trials

    Energy Technology Data Exchange (ETDEWEB)

    Melidis, Christos, E-mail: christos.melidis@eortc.be [European Organization for the Research and Treatment of Cancer–Radiation Oncology Group (EORTC-ROG), Radiation Therapy Quality Assurance (RTQA), Brussels (Belgium); Bosch, Walther R. [Washington University, representing Advanced Technology Consortium, Radiation Oncology, St. Louis, Missouri (United States); Izewska, Joanna [Dosimetry Laboratory, International Atomic Energy Agency, Vienna (Austria); Fidarova, Elena; Zubizarreta, Eduardo [Applied Radiation Biology and Radiotherapy Section, International Atomic Energy Agency, Vienna (Austria); Ulin, Kenneth [Department of Radiation Oncology, University of Massachusetts Medical School, Representing Quality Assurance Review Center, Worcester, Massachusetts (United States); Ishikura, Satoshi [Department of Radiation Oncology, Juntendo University, Representing Japan Clinical Oncology Group, RTQA, Tokyo (Japan); Followill, David [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Representing Radiological Physics Center, RTQA, Houston, Texas (United States); Galvin, James [Department of Radiation Oncology, Thomas Jefferson University, Representing Radiation Therapy Oncology Group, RTQA, Philadelphia, Pennsylvania (United States); Haworth, Annette [Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, representing TransTasman Radiation Oncology Group (TROG) Cancer Research, Newcastle (Australia); Besuijen, Deidre [North West Cancer Centre, Representing TROG Cancer Research, Newcastle (Australia); Clark, Clark H. [Department of Medical Physics, St. Luke' s Cancer Centre, Royal Surrey County Hospital, Guildford, Surrey and National Physical Laboratory, Teddington, Middlesex, representing Radiation Therapy Trials Quality Assurance (RTTQA) (United Kingdom); Miles, Elizabeth; Aird, Edwin [Mount Vernon Cancer Centre, Northwood, Middlesex representing RTTQA (United Kingdom); and others

    2014-12-01

    Purpose: To review the various radiation therapy quality assurance (RTQA) procedures used by the Global Clinical Trials RTQA Harmonization Group (GHG) steering committee members and present the harmonized RTQA naming conventions by amalgamating procedures with similar objectives. Methods and Materials: A survey of the GHG steering committee members' RTQA procedures, their goals, and naming conventions was conducted. The RTQA procedures were classified as baseline, preaccrual, and prospective/retrospective data capture and analysis. After all the procedures were accumulated and described, extensive discussions took place to come to harmonized RTQA procedures and names. Results: The RTQA procedures implemented within a trial by the GHG steering committee members vary in quantity, timing, name, and compliance criteria. The procedures of each member are based on perceived chances of noncompliance, so that the quality of radiation therapy planning and treatment does not negatively influence the trial measured outcomes. A comparison of these procedures demonstrated similarities among the goals of the various methods, but the naming given to each differed. After thorough discussions, the GHG steering committee members amalgamated the 27 RTQA procedures to 10 harmonized ones with corresponding names: facility questionnaire, beam output audit, benchmark case, dummy run, complex treatment dosimetry check, virtual phantom, individual case review, review of patients' treatment records, and protocol compliance and dosimetry site visit. Conclusions: Harmonized RTQA harmonized naming conventions, which can be used in all future clinical trials involving radiation therapy, have been established. Harmonized procedures will facilitate future intergroup trial collaboration and help to ensure comparable RTQA between international trials, which enables meta-analyses and reduces RTQA workload for intergroup studies.

  11. Development and evaluation of polycrystalline cadmium telluride dosimeters for accurate quality assurance in radiation therapy

    Science.gov (United States)

    Oh, K.; Han, M.; Kim, K.; Heo, Y.; Moon, C.; Park, S.; Nam, S.

    2016-02-01

    For quality assurance in radiation therapy, several types of dosimeters are used such as ionization chambers, radiographic films, thermo-luminescent dosimeter (TLD), and semiconductor dosimeters. Among them, semiconductor dosimeters are particularly useful for in vivo dosimeters or high dose gradient area such as the penumbra region because they are more sensitive and smaller in size compared to typical dosimeters. In this study, we developed and evaluated Cadmium Telluride (CdTe) dosimeters, one of the most promising semiconductor dosimeters due to their high quantum efficiency and charge collection efficiency. Such CdTe dosimeters include single crystal form and polycrystalline form depending upon the fabrication process. Both types of CdTe dosimeters are commercially available, but only the polycrystalline form is suitable for radiation dosimeters, since it is less affected by volumetric effect and energy dependence. To develop and evaluate polycrystalline CdTe dosimeters, polycrystalline CdTe films were prepared by thermal evaporation. After that, CdTeO3 layer, thin oxide layer, was deposited on top of the CdTe film by RF sputtering to improve charge carrier transport properties and to reduce leakage current. Also, the CdTeO3 layer which acts as a passivation layer help the dosimeter to reduce their sensitivity changes with repeated use due to radiation damage. Finally, the top and bottom electrodes, In/Ti and Pt, were used to have Schottky contact. Subsequently, the electrical properties under high energy photon beams from linear accelerator (LINAC), such as response coincidence, dose linearity, dose rate dependence, reproducibility, and percentage depth dose, were measured to evaluate polycrystalline CdTe dosimeters. In addition, we compared the experimental data of the dosimeter fabricated in this study with those of the silicon diode dosimeter and Thimble ionization chamber which widely used in routine dosimetry system and dose measurements for radiation

  12. Effects of gamma radiation on Sporothrix schenckii yeast cells

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, Camila M. de Sousa; Martins, Estefania Mara Nascimento; Andrade, Antero S.R. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)], e-mail: cmsl@cdtn.br, e-mail: estefaniabio@yahoo.com.br, e-mail: antero@cdtn.br; Resende, Maria Aparecida de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Microbiologia], e-mail: maressend@mono.icb.ufmg.br

    2009-07-01

    Sporotrichosis is a subacute or chronic infection caused by the fungus Sporothrix schenckii. Zoonotic transmission can occur after scratches or bites of animals, mainly cats, rodents, and armadillos. Up to the moment, no approved vaccine was reported for S. schenckii or to any important pathogenic fungi infection in humans, indicating the need to expand the research in this field and to explore new alternatives. The aim of this study was to evaluate the effects of gamma radiation in the viability, metabolic activity and reproductive ability of S. schenckii yeast cells for further studies on the development of a vaccine for immunization of cats and dogs. The culture of S. schenckii, in solid medium, was irradiated at doses ranging from 1.0 to 9.0 kGy. After each dose the reproductive capacity, viability and protein synthesis were estimated. The results showed that a reduction of 6 log{sub 10} cycles in the number of colonies was achieved at 6.0 kGy and after 8.0 kGy no colonies could be recovered. The viability analysis indicated that yeast cells remained viable up to 9.0 kGy. The results of protein synthesis analysis showed that the yeast cells, irradiated up to 9.0 kGy, were able to synthesize proteins. Our preliminary results indicated that for the yeast cells of S. schenckii, it is possible to find an absorbed dose in which the pathogen loses its reproductive ability, while retaining its viability, a necessary condition for the development of a radioattenuated yeast vaccine. (author)

  13. SU-E-P-11: Comparison of Image Quality and Radiation Dose Between Different Scanner System in Routine Abdomen CT

    Energy Technology Data Exchange (ETDEWEB)

    Liao, S; Wang, Y; Weng, H [Chiayi Chang Gung Memorial Hospital of The C.G.M.F, Puzi City, Chiayi County, Taiwan (China)

    2015-06-15

    Purpose To evaluate image quality and radiation dose of routine abdomen computed tomography exam with the automatic current modulation technique (ATCM) performed in two different brand 64-slice CT scanners in our site. Materials and Methods A retrospective review of routine abdomen CT exam performed with two scanners; scanner A and scanner B in our site. To calculate standard deviation of the portal hepatic level with a region of interest of 12.5 mm x 12.5mm represented to the image noise. The radiation dose was obtained from CT DICOM image information. Using Computed tomography dose index volume (CTDIv) to represented CT radiation dose. The patient data in this study were with normal weight (about 65–75 Kg). Results The standard deviation of Scanner A was smaller than scanner B, the scanner A might with better image quality than scanner B. On the other hand, the radiation dose of scanner A was higher than scanner B(about higher 50–60%) with ATCM. Both of them, the radiation dose was under diagnostic reference level. Conclusion The ATCM systems in modern CT scanners can contribute a significant reduction in radiation dose to the patient. But the reduction by ATCM systems from different CT scanner manufacturers has slightly variation. Whatever CT scanner we use, it is necessary to find the acceptable threshold of image quality with the minimum possible radiation exposure to the patient in agreement with the ALARA principle.

  14. The different radiation response and radiation-induced bystander effects in colorectal carcinoma cells differing in p53 status

    Energy Technology Data Exchange (ETDEWEB)

    Widel, Maria, E-mail: maria.widel@polsl.pl [Biosystems Group, Institute of Automatic Control, Silesian University of Technology, 16 Akademicka Street, 44-100 Gliwice (Poland); Lalik, Anna; Krzywon, Aleksandra [Biosystems Group, Institute of Automatic Control, Silesian University of Technology, 16 Akademicka Street, 44-100 Gliwice (Poland); Poleszczuk, Jan [College of Inter-faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, 93 Zwirki i Wigury Street, 02-089 Warsaw (Poland); Department of Integrated Mathematical Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida (United States); Fujarewicz, Krzysztof; Rzeszowska-Wolny, Joanna [Biosystems Group, Institute of Automatic Control, Silesian University of Technology, 16 Akademicka Street, 44-100 Gliwice (Poland)

    2015-08-15

    Highlights: • We tested radiation response and bystander effect on HCT116p53+/+ and p53−/− cells. • The p53+/+ cells developed premature senescence in exposed and bystander neighbors. • Directly exposed and bystander p53−/− cells died profoundly through apoptosis. • Interleukins 6 and 8 were differently generated by both cell lines. • NFκB path was activated mainly in p53+/+ hit cells, in p53 −/− in bystanders only. - Abstract: Radiation-induced bystander effect, appearing as different biological changes in cells that are not directly exposed to ionizing radiation but are under the influence of molecular signals secreted by irradiated neighbors, have recently attracted considerable interest due to their possible implication for radiotherapy. However, various cells present diverse radiosensitivity and bystander responses that depend, inter alia, on genetic status including TP53, the gene controlling the cell cycle, DNA repair and apoptosis. Here we compared the ionizing radiation and bystander responses of human colorectal carcinoma HCT116 cells with wild type or knockout TP53 using a transwell co-culture system. The viability of exposed to X-rays (0–8 Gy) and bystander cells of both lines showed a roughly comparable decline with increasing dose. The frequency of micronuclei was also comparable at lower doses but at higher increased considerably, especially in bystander TP53-/- cells. Moreover, the TP53-/- cells showed a significantly elevated frequency of apoptosis, while TP53+/+ counterparts expressed high level of senescence. The cross-matched experiments where irradiated cells of one line were co-cultured with non-irradiated cells of opposite line show that both cell lines were also able to induce bystander effects in their counterparts, however different endpoints revealed with different strength. Potential mediators of bystander effects, IL-6 and IL-8, were also generated differently in both lines. The knockout cells secreted IL-6 at

  15. Survival Assessment of Mouse Preimplantation Embryos After Exposure to Cell Phone Radiation

    Science.gov (United States)

    Safian, Fereshteh; Khalili, Mohammad Ali; Khoradmehr, Arezoo; Anbari, Fatemeh; Soltani, Saeedeh; Halvaei, Iman

    2016-01-01

    Background: Using cellular phone has rapidly increased all over the world. Also, the concern on the possible health hazards of electromagnetic fields (EMF) induced from cell phones to reproduction has been growing in many countries. The aim of this study was to assess the consequences and effects of exposure to the cell phone radiation on the quality and survival rates of preimplantation embryos in mice. Methods: A total of 40 mice (20 females and 20 males), 6 weeks old and sexually mature BALB/c, were used for control and experimental groups. The ovary burses were removed and the zygotes were dissected in the morning after mating. Next, 2-cell embryos were divided into two groups of control (n=150) and experimental (n=150). EMF (900–1800 MHz) was used for four days in experimental group for 30 min/day in culture at 37°C in a CO 2 incubator. The quality of embryos was recorded daily and the fluorescent staining was used for identification of viable blastocysts. All data were compared by Student’s t-test and Mann-Whitney test (p<0.05). Results: The rate of embryo survival to the blastocysts stage was similar in both groups. However, the percentage of dead embryos at the 2-cell stage was significantly higher in EMF-exposed group compared with controls (p=0.03). Also, the loss of cell viability significantly increased in experimental blastocysts (p=0.002). Conclusion: The normal embryonic development up to the blastocyst stage indicates that EMF-exposure commonly did not have adverse effect on embryo development in mice. But, it caused loss of blastocysts cell viability. PMID:27478766

  16. Immobilization of microbial cell and yeast cell and its application to biomass conversion using radiation techniques

    Science.gov (United States)

    Kaetsu, Isao; Kumakura, Minoru; Fujimura, Takashi; Kasai, Noboru; Tamada, Masao

    The recent results of immobilization of cellulase-producing cells and ethanol-fermentation yeast by radiation were reported. The enzyme of cellulase produced by immobilized cells was used for saccharification of lignocellulosic wastes and immobilized yeast cells were used for fermentation reaction from glucose to ethanol. The wastes such as chaff and bagasse were treated by γ-ray or electron-beam irradiation in the presence of alkali and subsequent mechanical crushing, to form a fine powder less than 50 μm in diameter. On the other hand, Trichoderma reesei as a cellulase-producing microbial cell was immobilized on a fibrous carrier having a specific porous structure and cultured to produce cellulase. The enzymatic saccharification of the pretreated waste was carried out using the produced cellulase. The enhanced fermentation process to produce ethanol from glucose with the immobilized yeast by radiation was also studied. The ethanol productivity of immobilized growing yeast cells thus obtained was thirteen times that of free yeast cells in a 1:1 volume of liquid medium to immobilized yeast cells.

  17. Tumour microenvironment and radiation response in sarcomas originating from tumourigenic human mesenchymal stem cells

    DEFF Research Database (Denmark)

    D'Andrea, Filippo Peder; Safwat, Akmal Ahmed; Burns, Jorge S.;

    2012-01-01

    Background: Resistance to radiation therapy remains a serious impediment to cancer therapy. We previously reported heterogeneity for clonogenic survival when testing in vitro radiation resistance among single cell derived clones from a human mesenchymal cancer stem cell model (hMSC). Here we aimed...

  18. 324 Facility B-Cell quality process plan

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, J.L.

    1998-03-12

    This report documents the quality process plan for the restart of a hot cell in the B Plant, originally a bismuth phosphate processing facility, but later converted to a waste fractionation plant. B-Cell is currently being cleaned out and deactivated. TPA Milestone M-89-02 dictates that all mixed waste and equipment be removed from B-Cell by 5/31/1999. This report describes the major activities that remain for completion of the TPA milestone.

  19. Coronary computed tomography angiography using ultra-low-dose contrast media: radiation dose and image quality.

    Science.gov (United States)

    Komatsu, Sei; Kamata, Teruaki; Imai, Atsuko; Ohara, Tomoki; Takewa, Mitsuhiko; Ohe, Ryoko; Miyaji, Kazuaki; Yoshida, Junichi; Kodama, Kazuhisa

    2013-08-01

    To analyze the invasiveness and image quality of coronary CT angiography (CCTA) with 80 kV. We enrolled 181 patients with low body weight and low calcium level. Of these, 154 patients were randomly assigned to 1 of 3 groups: 280 HU/80 kV (n = 51); 350 HU/80 kV (n = 51); or 350 HU/120 kV (n = 52). The amount of contrast media (CM) was decided with a CT number-controlling system. Twenty-seven patients were excluded because of an invalid time density curve by timing bolus. The predicted amount of CM, volume CT dose index, dose-length product, effective dose, image noise, and 5-point image quality were measured. The amounts of CM for the 80 kV/280 HU, 80 kV/350 HU, and 120 kV/350 HU groups were 10 ± 4 mL, 15 ± 7 mL, and 30 ± 6 mL, respectively. Although image noise was greater at 80 than 120 kV, there was no significant difference in image quality between 80 kV/350 HU and 120 kV/350 HU (p = 0.390). There was no significant difference in image quality between 80 kV/280 HU and 80 kV/350 HU (4.4 ± 0.7 vs. 4.7 ± 0.4, p = 0.056). The amount of CM and effective dose was lower for 80 kV CCTA than for 120 kV CCTA. CCTA at 80 kV/280 HU may decrease the amount of CM and radiation dose necessary while maintaining image quality.

  20. Voice Quality After Treatment of Early Vocal Cord Cancer: A Randomized Trial Comparing Laser Surgery With Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Aaltonen, Leena-Maija, E-mail: leena-maija.aaltonen@hus.fi [Department of Otorhinolaryngology–Head and Neck Surgery, Helsinki University Central Hospital, and University of Helsinki, Helsinki (Finland); Rautiainen, Noora; Sellman, Jaana [Institute of Behavioural Sciences, University of Helsinki, Helsinki (Finland); Saarilahti, Kauko [Department of Oncology, Helsinki University Central Hospital, and University of Helsinki, Helsinki (Finland); Mäkitie, Antti; Rihkanen, Heikki [Department of Otorhinolaryngology–Head and Neck Surgery, Helsinki University Central Hospital, and University of Helsinki, Helsinki (Finland); Laranne, Jussi; Kleemola, Leenamaija [Department of Otorhinolaryngology–Head and Neck Surgery, Tampere University Hospital, and University of Tampere, Tampere (Finland); Wigren, Tuija [Department of Oncology, Tampere University Hospital, and University of Tampere, Tampere (Finland); Sala, Eeva [Department of Otorhinolaryngology–Head and Neck Surgery, Turku University Hospital, and University of Turku, Turku (Finland); Lindholm, Paula [Department of Oncology, Turku University Hospital, and University of Turku, Turku (Finland); Grenman, Reidar [Department of Otorhinolaryngology–Head and Neck Surgery, Turku University Hospital, and University of Turku, Turku (Finland); Joensuu, Heikki [Department of Oncology, Helsinki University Central Hospital, and University of Helsinki, Helsinki (Finland)

    2014-10-01

    Objective: Early laryngeal cancer is usually treated with either transoral laser surgery or radiation therapy. The quality of voice achieved with these treatments has not been compared in a randomized trial. Methods and Materials: Male patients with carcinoma limited to 1 mobile vocal cord (T1aN0M0) were randomly assigned to receive either laser surgery (n=32) or external beam radiation therapy (n=28). Surgery consisted of tumor excision with a CO{sub 2} laser with the patient under general anaesthesia. External beam radiation therapy to the larynx was delivered to a cumulative dose of 66 Gy in 2-Gy daily fractions over 6.5 weeks. Voice quality was assessed at baseline and 6 and 24 months after treatment. The main outcome measures were expert-rated voice quality on a grade, roughness, breathiness, asthenia, and strain (GRBAS) scale, videolaryngostroboscopic findings, and the patients' self-rated voice quality and its impact on activities of daily living. Results: Overall voice quality between the groups was rated similar, but voice was more breathy and the glottal gap was wider in patients treated with laser surgery than in those who received radiation therapy. Patients treated with radiation therapy reported less hoarseness-related inconvenience in daily living 2 years after treatment. Three patients in each group had local cancer recurrence within 2 years from randomization. Conclusions: Radiation therapy may be the treatment of choice for patients whose requirements for voice quality are demanding. Overall voice quality was similar in both treatment groups, however, indicating a need for careful consideration of patient-related factors in the choice of a treatment option.

  1. Resistance of colorectal cancer cells to radiation and 5-FU is associated with MELK expression

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seungho [Laboratory of Cell Biology, Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Ku, Ja-Lok, E-mail: kujalok@snu.ac.kr [Laboratory of Cell Biology, Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of)

    2011-08-26

    Highlights: {yields} MELK expression significantly increased when the cells are exposed to radiation or 5-FU. {yields} Suppression of MELK caused cell cycle changes and decrease in proliferation. {yields} Radiation or 5-FU treatment after MELK suppression by siRNA induced growth inhibition. -- Abstract: It was reported that the local recurrence would be caused by cancer stem cells acquiring chemo- and radio-resistance. Recently, one of the potential therapeutic targets for colorectal and other cancers has been identified, which is maternal embryonic leucine zipper kinase (MELK). MELK is known as an embryonic and neural stem cell marker, and associated with the cell survival, cell proliferation, and apoptosis. In this study, SNU-503, which is a rectal cancer cell line, was treated with radiation or 5-fluorouracil (5-FU), and elevation of the MELK expression level was observed. Furthermore, the cell line was pre-treated with small interfering RNA (siRNA) against MELK mRNA before treatment of radiation or 5-FU and its effects on cell cycle and proliferation were observed. We demonstrated that knockdown of MELK reduced the proliferation of cells with radiation or 5-FU treatment. In addition, MELK suppression caused changes in cell cycle. In conclusion, MELK could be associated with increased resistance of colorectal cancer cells against radiation and 5-FU.

  2. Radiation enteritis

    Science.gov (United States)

    Radiation enteropathy; Radiation-induced small bowel injury; Post-radiation enteritis ... Radiation therapy uses high-powered x-rays, particles, or radioactive seeds to kill cancer cells. The therapy ...

  3. Web-based tools for quality assurance and radiation protection in diagnostic radiology.

    Science.gov (United States)

    Moores, B M; Charnock, P; Ward, M

    2010-01-01

    Practical and philosophical aspects of radiation protection in diagnostic radiology have changed very little over the past 50 y even though patient doses have continued to rise significantly in this period. This rise has been driven by technological developments, such as multi-slice computed tomography, that have been able to improve diagnostic accuracy but not necessarily provide the same level of risk-benefit to all patients or groups of patients given the dose levels involved. Can practical radiation protection strategies hope to keep abreast of these ongoing developments? A project was started in 1992 in Liverpool that aimed to develop IT driven quality assurance (QA)/radiation protection software tools based upon a modular quality assurance dose data system. One of the modules involved the assessment of the patient entrance surface air kerma (ESAK) for an X-ray examination that was based upon the use of calibrated X-ray tube exposure factors to calculate ESAK as well as collecting appropriate patient details (age, sex, weight, thickness etc). The package also contained modules for logging all necessary equipment performance QA data. This paper will outline the experience gained with this system through its transition from a local application on a stand alone PC within the department to the current web-based approach. Advantages of a web-based approach to delivering such an application as well as centrally storing data originating on many hospital sites will be discussed together with the scientific support processes that can be developed with such a system. This will include local, national and international considerations. The advantages of importing radiographic examination details directly from other electronic storage systems such as a hospital's radiology information system will be presented together with practical outcomes already achieved. This will include the application of statistical techniques to the very large data sets generated. The development

  4. Chronic low-dose radiation protects cells from high-dose radiation via increase of AKT expression by NF-{sub k}B

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyung Sun; Seong, Ki Moon; Kim, Ji Young; Kim, Cha Soon; Yang, Kwang Hee; Nam, Seon Young [Radiation Effect Research Team, Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., LTD., Gyeongju (Korea, Republic of)

    2013-04-15

    Exposure to low-dose and low-dose rate of ionizing radiation is an important issue in radiation protection. Low-dose ionizing radiation has been observed to elicit distinctly different responses compared to high-dose radiation, in various biological systems including the reproductive, immune, and hematopoietic systems (Liu et al. 2006). Some data were reported that low-dose radiation could initiate beneficial effects by stimulating cell growth, DNA repair, activation of transcription factors and gene expression (Calabrese et al., 2004). Cells exposed to low-dose radiation can develop adaptive resistance to subsequent high-dose radiation induced DNA damage, gene mutation, and cell death. We previously reported that low-dose of ionizing radiation induced cell survival through the activation of AKT (protein kinase B, PKB) pathway (Park et al., 2009). AKT has been shown to be potently activated in response to a wide variety of growth factors and ionizing radiation. Cell survival against ionizing radiation seems to be associated with the activation of AKT pathway via phosphorylation of its downstream nuclear target molecules. In the present study, we examined the effects of chronic low-dose irradiation in human lung fibroblast cells. The aim was to explore the possibility of a low-dose radiation-induced adaptive cellular response against subsequent challenging high-dose irradiation. In the present study, we examined the regulatory mechanism responsible for cellular response induced by chronic low-dose of ionizing radiation in normal human cells. We found that the level of AKT protein was closely associated with cell survival. In addition, NF-{sub k}B activation by chronic low-dose radiation regulates AKT activation via gene expression and acinus expression. In conclusion, our data demonstrate that chronic low-dose radiation could inhibit the cell death induced by cytotoxic high-dose radiation through the modulation of the level of AKT and acinus proteins via NF-{sub k

  5. Cell proliferation kinetics and radiation response in 9L tumor spheroids

    Energy Technology Data Exchange (ETDEWEB)

    Sweigert, S.E.

    1984-05-01

    Cell kinetic parameters, including population doubling-time, cell cycle time, and growth fraction, were measured in 9L gliosarcoma spheroids. These parameters were studied as the spheroids grew from 50 ..mu..m to over 900 ..mu..m in diameter. Experiments relating the cell kinetic parameters to the radiation response of 9L spheroids were also carried out. The major findings were that the average cell cycle time (T/sub c/), is considerably longer in large spheroids than in exponentially-growing monolayers, the radiosensitivity of noncycling (but still viable) cells in spheroids is not significantly different from that of cycling spheroid cells, and the radiation-induced division delay is approximately twice as long in spheroid cells as in monolayer cells given equal radiation doses. The cell loss factor for spheroids of various sizes was calculated, by using the measured kinetic parameters in the basic equations for growth of a cell population. 157 references, 6 figures, 3 tables.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-12-15

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

  7. Experimental treatment of radiation pneumonitis with human umbilical cord mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    Rui Wang; Chang-zheng Zhu; Ping Qiao; Jian Liu; Qiang Zhao; Kui-jie Wang; Ting-bao Zhao

    2014-01-01

    Objective: To evaluate of the curative effect of human umbilical cord mesenchymal stem cells (hUC-MSCs) on rat acute radiation pneumonitis. Methods: Fourty rats were randomly divided into control group, radiation group, stem cell prevention group, stem cell treatment group and prednisone treatment group. All rats except those in the control group were radiated with X ray to establish the acute radiation pneumonitis damage model. The hUC-MSCs cultured in vitro was administrated to the rats of the prevention group via tail vein (1×106 cells/kg BW) 24 h before the radiation, while the same administration was performed in the rats of the treatment group 24 h after the radiation. After 24 h post the radiation, the rats in the radiation group were given 0.4 mL physiological saline, and those in the prednisone group were given 1 mg/kg prednisone. All rats were observed and executed 72 h after the radiation to detect lung histological changes. Results:After the administration of hUC-MSCs, the survival status of the rats in the prevention group and treatment group was obviously better than that in the control group. As shown by the histological staining, the morphology, proliferation activity and bronchial state of lung tissues were better in the prevention group and treatment group than in the control group. Conclusion: The hUC-MSCs have definite therapeutic effects on acute radiation pneumonitis in rats.

  8. Analysis of Genotoxic and Cytotoxic Responses Induced by Simulated Space Radiation Qualities by Use of Recombinant Bacteria Carrying a Dual-Function Dual-Reporter Construct

    Science.gov (United States)

    Baumstark-Khan, Christa; Hellweg, Christine; Zahoor, Ahmed; Testard, Isabelle; Reitz, Guenther

    Along with the long-term space exploration come various potential health risks due to unique physical factors of the space environment. Space radiation is one of the primary environmental hazards associated with space flight. In order to deal with space-related risk radiation exposure must be properly characterised and quantified, and biological effects of charged particles have to be analysed in ground based research, especially as astronauts are subjected to a differing radiation quality in space than they receive on Earth. For risk assessment, the mutagenic potential of the heavy ion component of the galactic cosmic radiation is of major concern for tumour induction as radiation late effects. The recombinant SWITCH test is based on TA1535 Salmonella typhimurium cells transformed with a dual-function dual-reporter vector harbouring (a) the genes for bioluminescence production from Photobacterium leiognathi under the control of a DNA-damage inducible promoter and (b) the gene for green fluorescent protein from the jellyfish Aequorea victoria under the control of a constitutive promoter. Suchlike genetically modified organism report on the presence of genotoxic conditions by dose dependent increase of bioluminescence induction and on the presence of cytotoxic conditions by dose dependent decrease in GFP fluorescence. By this, it is possible to analyse bacterial inactivation and mutation induction by ionizing radiation in parallel in the same cell within short time. Experiments with heavy ions have been performed with the SWITCH test at GANIL with the following accelerated heavy ions: 35 MeV/u (72 keV/µm) and 75 MeV/u (37 keV/µm) carbon, 95 MeV/u argon (377 keV/µm), 95 MeV/u neon (98 keV/µm), 75 MeV/u nickel (967 keV/µm) and 29 MeV/u lead (10238 keV/µm). The results obtained clearly show that the numbers of hits (particles per cm2 ) necessary to inactivate the bacteria (cytotoxicity) depend on LET. The higher the ionisation capacity of the accelerated ion, the

  9. Laser flow microphotometry for rapid analysis and sorting of mammalian cells. [X and gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Mullaney, P.F.; Steinkamp, J.A.; Crissman, H.A.; Cram, L.S.; Crowell, J.M.; Salzman, G.C.; Martin, J.C.; Price, B.

    1976-01-01

    Quantitative precision measurements can be made of the optical properties of individual mammalian cells using flow microphotometry. Suspended cells pass through a special flow chamber where they are lined up for exposure to blue light from an argon-ion laser. As each cell crosses the laser beam, it produces one or more optical pulses of a duration equal to cell transit time across the beam. These pulses are detected, amplified, and analyzed using the techniques of gamma ray spectroscopy. Quantitative DNA distributions made it possible to distinguish tumor cells from normal cells as well as to assay for radiation effects on tumor cells subjected to x and gamma radiation. (HLW)

  10. CLONING AND EXPRESSION OF A GENE MEDIATINGγ-RADIATION-INDUCED APOPTOSIS IN HL-60 CELLS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective To identify the member of the caspase family proteases involved in γ-radiation-induced apoptosis in HL-60 cells and to study the expression of the caspase gene in normal, apoptotic cells and in immortal tu mor cells. Methods By using degenerate oligonucleotide primers encoding the highly conserved peptides that were pre sent in all known caspases, we performed RT-PCR on poly(A)RNA from γ-radiation-induced apoptotic HL-60 cells. Caspase-3 mRNA in apoptotic HL-60 cells and in human tumor cell lines was analyzed by Northern blot. Results The amplified DNA fragment was identified with caspase-3 cDNA by cloning and sequencing. The Northern blot analysis of caspase-3 mRNA of different human tumor cell lines showed that the caspase-3 gene transcript was more highly ex pressed in leukemia cell lines and the SH-SY5Y cell line than in HeLa and MCF-7 cells. It was more highly expressed in the radiation-induced apoptotic HL-60 cells than in control HL-60 cells. Conclusion These results indicated that caspase-3 was involved in γ-radiation-induced apoptosis in HL-60 cells. The high level of expression of caspase-3 may aid efforts to understand the insensitivity of some tumor cells to radiation, their inherent ability to survive, and apop tosis.

  11. Association Between White Blood Cell Count Following Radiation Therapy With Radiation Pneumonitis in Non-Small Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Chad; Gomez, Daniel R. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Wang, Hongmei [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou (China); Levy, Lawrence B. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zhuang, Yan [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Xu, Ting; Nguyen, Quynh; Komaki, Ritsuko [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Liao, Zhongxing, E-mail: zliao@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2014-02-01

    Purpose: Radiation pneumonitis (RP) is an inflammatory response to radiation therapy (RT). We assessed the association between RP and white blood cell (WBC) count, an established metric of systemic inflammation, after RT for non-small cell lung cancer. Methods and Materials: We retrospectively analyzed 366 patients with non-small cell lung cancer who received ≥60 Gy as definitive therapy. The primary endpoint was whether WBC count after RT (defined as 2 weeks through 3 months after RT completion) was associated with grade ≥3 or grade ≥2 RP. Median lung volume receiving ≥20 Gy (V{sub 20}) was 31%, and post-RT WBC counts ranged from 1.7 to 21.2 × 10{sup 3} WBCs/μL. Odds ratios (ORs) associating clinical variables and post-RT WBC counts with RP were calculated via logistic regression. A recursive-partitioning algorithm was used to define optimal post-RT WBC count cut points. Results: Post-RT WBC counts were significantly higher in patients with grade ≥3 RP than without (P<.05). Optimal cut points for post-RT WBC count were found to be 7.4 and 8.0 × 10{sup 3}/μL for grade ≥3 and ≥2 RP, respectively. Univariate analysis revealed significant associations between post-RT WBC count and grade ≥3 (n=46, OR=2.6, 95% confidence interval [CI] 1.4‒4.9, P=.003) and grade ≥2 RP (n=164, OR=2.0, 95% CI 1.2‒3.4, P=.01). This association held in a stepwise multivariate regression. Of note, V{sub 20} was found to be significantly associated with grade ≥2 RP (OR=2.2, 95% CI 1.2‒3.4, P=.01) and trended toward significance for grade ≥3 RP (OR=1.9, 95% CI 1.0-3.5, P=.06). Conclusions: Post-RT WBC counts were significantly and independently associated with RP and have potential utility as a diagnostic or predictive marker for this toxicity.

  12. The modulation of radiation-induced cell death by genistein in K562 cells:Activation of thymidine kinase 1

    Institute of Scientific and Technical Information of China (English)

    Min Ho JEONG; Young Hee JIN; Eun Young KANG; Wol Soon JO; Hwan Tae PARK; Jae Dong LEE; Yeo Jin YOO; Soo Jin JEONG

    2004-01-01

    Ionizing radiation is one of the most effective tools in cancer therapy. In a previous study, we reported that protein tyrosine kinase (PTK) inhibitors modulate the radiation responses in the human chronic myelogenous leukemia (CML)cell line K562. The receptor tyrosine kinase inhibitor, genistein, delayed radiation-induced cell death, while non-recepter tyrosine kinase inhibitor, herbimycin A (HMA) enhances radiation-induced apoptosis. In this study, we focused on the modulation of radiation-induced cell death by genistein and performed PCR-select suppression subtractive hybridization(SSH) to understand its molecular mechanism. We identified human thymidine kinase 1 (TK1), which is cell cycle regulatory gene and confirmed expression of TK1 mRNA by Northern blot analysis. Expression of TK1 mRNA and TK 1enzymatic activity were parallel in their increase and decrease. TK1 is involved in G1-S phase transition of cell cycle progression. In cell cycle analysis, we showed that radiation induced G2 arrest in K562 cells but it was not able to sustain. However, the addition of genistein to irradiated cells sustained a prolonged G2 arrest up to 120 h. In addition,the expression of cell cycle-related proteins, cyclin A and cyclin B 1, provided the evidences of G1/S progression and G2-arrest, and their relationship with TK1 in cells treated with radiation and genistein. These results suggest that the activation of TK1 may be critical to modulate the radiation-induced cell death and cell cycle progression in irradiated K562 cells.

  13. Quality control methodology and implementation of X-radiation standards beams, mammography level, following the standard IEC 61267.

    Science.gov (United States)

    Corrêa, E L; Vivolo, V; Potiens, M P A

    2012-07-01

    This study presents the results of the establishment of a quality control program developed and applied for the X-ray system of the Calibration Laboratory of IPEN. The X-ray standard beams, mammography level, using molybdenum and aluminum as additional filtration were established after the application of this quality control and the spectrometry of these qualities was made. The reference ionization chamber has traceability to the PTB. The radiation qualities RQR-M, RQA-M, RQN-M and RQB-M, following the recommendations of the IEC 61267 and the IAEA TRS 457 were established.

  14. Chest CT using spectral filtration: radiation dose, image quality, and spectrum of clinical utility

    Energy Technology Data Exchange (ETDEWEB)

    Braun, Franziska M.; Johnson, Thorsten R.C.; Sommer, Wieland H.; Thierfelder, Kolja M.; Meinel, Felix G. [University Hospital Munich, Institute for Clinical Radiology, Munich (Germany)

    2015-06-01

    To determine the radiation dose, image quality, and clinical utility of non-enhanced chest CT with spectral filtration. We retrospectively analysed 25 non-contrast chest CT examinations acquired with spectral filtration (tin-filtered Sn100 kVp spectrum) compared to 25 examinations acquired without spectral filtration (120 kV). Radiation metrics were compared. Image noise was measured. Contrast-to-noise-ratio (CNR) and figure-of-merit (FOM) were calculated. Diagnostic confidence for the assessment of various thoracic pathologies was rated by two independent readers. Effective chest diameters were comparable between groups (P = 0.613). In spectral filtration CT, median CTDI{sub vol}, DLP, and size-specific dose estimate (SSDE) were reduced (0.46 vs. 4.3 mGy, 16 vs. 141 mGy*cm, and 0.65 vs. 5.9 mGy, all P < 0.001). Spectral filtration CT had higher image noise (21.3 vs. 13.2 HU, P < 0.001) and lower CNR (47.2 vs. 75.3, P < 0.001), but was more dose-efficient (FOM 10,659 vs. 2,231/mSv, P < 0.001). Diagnostic confidence for parenchymal lung disease and osseous pathologies was lower with spectral filtration CT, but no significant difference was found for pleural pathologies, pulmonary nodules, or pneumonia. Non-contrast chest CT using spectral filtration appears to be sufficient for the assessment of a considerable spectrum of thoracic pathologies, while providing superior dose efficiency, allowing for substantial radiation dose reduction. (orig.)

  15. Quality profile of litchi (Litchi chinensis) cultivars from India and effect of radiation processing

    Energy Technology Data Exchange (ETDEWEB)

    Hajare, Sachin N.; Saxena, Sudhanshu; Kumar, Sanjeev; Wadhawan, Surbhi; More, Varsha; Mishra, B.B.; Narayan Parte, Madan; Gautam, Satyendra [Food Technology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Sharma, Arun, E-mail: ksarun@barc.gov.i [Food Technology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2010-09-15

    Litchi (Litchi chinensis) is a non-climacteric tropical fruit. The fruit has a short shelf-life making its marketing difficult. Physical, biochemical, microbiological, and organoleptic properties of two major commercially grown Indian cultivars of litchi, 'Shahi' and 'China' were studied. The effect of gamma radiation processing and low temperature storage on the above parameters was evaluated to standardize the optimal process parameters for shelf-life extension of litchi. Physical and biochemical parameters analyzed included weight, moisture, pH, titratable acidity, texture, color, total and reducing sugar, total soluble solids, vitamin C, and flavonoid content. Weight, moisture content, and pH in the fresh fruit ranged between 21-26 g, 74-77%, and 3.7-4.4, respectively, whereas, total and reducing sugar ranged 10-15, and 10-13 g%, respectively. In 'Shahi' vitamin C content was found to be around 17-19 mg%, whereas, in 'China' it was 22-28 mg%. Flavonoid content was in the range of 26-34 {mu}g catechin equivalents/g of fresh fruit. Total surface and internal bacterial load was around 4 and 3 log cfu/g, respectively. Surface yeast-mold count (YMC) was {approx}3 log cfu/g whereas internal YMC was {approx}2 log cfu/g. Radiation treatment reduced microbial load in a dose dependent manner. Treatment at 0.5 kGy did not significantly affect the quality parameters of the fruit. Treated fruits retained the 'good' organoleptic rating during storage. Thus, radiation treatment (0.5 kGy) in combination with low temperature (4 {sup o}C) storage achieved a shelf-life of 28 days for litchi fruit.

  16. 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.

  17. Effect of PGE2 on radiation response of chinese hamster V79 cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Holahan, E.V.; Blakely, W.F.; Walden, T.L.

    1987-01-01

    Several recent investigations have reported that 16,16-dimethyl prostaglandin E2 (DiPGE2) can protect murine intestinal epithelial cells and hematopoietic stem cells (CFU-S) in vivo from ionizing radiation. It has been postulated that PGE2 may also increase radiation resistance in vitro by stimulating free-radical scavenging or repair systems for oxidative damage. This study reports on the effect of PGE2 in modifying radiation sensitivity in an in vitro mammalian cell line. Chinese hamster V79A03 cells were cultured. Exponentially growing cells were incubated before exposure to graded doses of 250-kVp X rays. Cells were assayed for variations in intracellular levels of cyclic 3',5'-adenosine monophosphate (cAMP), total protein, and glutathione (GSH), and radiation sensitivity was measured by cell survival before and after PGE2 treatment. An acute (2-hr) exposure induced a 25% increase in cAMP content with no significant change in intracellular GSH or protein and no effect on cell survival after exposure to radiation. Chronic exposure to PGE2 increased intracellular GSH, protein, and cAMP levels by 82%, 3%, and 74%, respectively. However, no increase in radiation resistance was apparent following chronic exposure to PGE2. The increased radiation resistance observed in vitro may be due to modifications such as localized tissue or organ-system hypoxia.

  18. Improved postharvest quality in patagonian squash ( Cucurbita moschata) coated with radiation depolymerized chitosan

    Science.gov (United States)

    Pugliese, Maria Alicia; Goitia, Maria Teresa; Yossen, Mariana; Cifone, Norma; Agulló, Enrique; Andreucetti, Noemi

    2011-12-01

    Different molecular weight chitosans were evaluated on the decay of coated Anquito squashes ( Cucurbita moschata) as well as the maintenance of the fruit quality along five storage months. The original chitosan (Mw=391 kDa, 83% DD), was depolymerized by gamma radiation. Apart from chain scission, other chemical changes were not detected by FTIR or UV-vis analyses. The molecular weight characterization of chitosans was done by size exclusion chromatography with dual light scattering and concentration detection (SEC-MALLS-RI). The coating effectiveness was evaluated on the following parameters: fungal decay incidence, weight loss, firmness, total reducing sugar, soluble solid, flesh color, carotene content, pH and titratable acidity. No sign of fungal decay was observed in squashes coated with 122 and 56 kDa chitosans, which were also the most effective treatments in reducing the weight loss. The chitosan with Mw=122 kDa was also the best treatment considering firmness, internal aspect, sugar and carotene content. Then, radiation degraded chitosan was better in C. moschata preservation than the original chitosan.

  19. National Survey of Radiation Dose and Image Quality in Adult CT Head Scans in Taiwan.

    Directory of Open Access Journals (Sweden)

    Chung-Jung Lin

    Full Text Available The purpose of the present study was to evaluate the influence of different variables on radiation dose and image quality based on a national database.Taiwan's Ministry of Health and Welfare requested all radiology departments to complete a questionnaire for each of their CT scanners. Information gathered included all scanning parameters for CT head scans. For the present analysis, CT machines were divided into three subgroups: single slice CT (Group A; multi-detector CT (MDCT with 2-64 slices (Group B; and MDCT with more than 64 slices (Group C. Correlations between computed tomography dose index (CTDI and signal-to-noise ratio (SNR with cumulated tube rotation number (CTW(n and cumulated tube rotation time (CTW(s, and sub group analyses of CTDI and SNR across the three groups were performed.CTDI values demonstrated a weak correlation (r = 0.33 with CTW(n in Group A. SNR values demonstrated a weak negative correlation (r = -0.46 with CTW(n in Group C. MDCT with higher slice numbers used more tube potential resulting in higher effective doses. There were both significantly lower CTDI and SNR values in helical mode than in axial mode in Group B, but not Group C.CTW(n and CTW(s did not influence radiation output. Helical mode is more often used in MDCT and results in both lower CTDI and SNR compared to axial mode in MDCT with less than 64 slices.

  20. Temperature coefficients and radiation induced DLTS spectra of MOCVD grown n(+)p InP solar cells

    Science.gov (United States)

    Walters, Robert J.; Statler, Richard L.; Summers, Geoffrey P.

    1991-01-01

    The effects of temperature and radiation on n(+)p InP solar cells and mesa diodes grown by metallorganic chemical vapor deposition (MOCVD) were studied. It was shown that MOCVD is capable of consistently producing good quality InP solar cells with Eff greater than 19 percent which display excellent radiation resistance due to minority carrier injection and thermal annealing. It was also shown that universal predictions of InP device performance based on measurements of a small group of test samples can be expected to be quite accurate, and that the degradation of an InP device due to any incident particle spectrum should be predictable from a measurement following a single low energy proton irradiation.

  1. Quality Management in Indian Higher Education System: Role of Internal Quality Assurance Cell (IQAC

    Directory of Open Access Journals (Sweden)

    V.S. Mangnale

    2011-11-01

    Full Text Available The primary objective of this research is to explore the perceptions of both the higher education institutions and students on the various quality deliverables in the Indian higher education system along with careful observation of the role of Internal Quality Assurance Cell (IQAC in sustaining quality delivery of education service. The research study reviewed the germane literature on higher education and quality management in higher education. Then, the researchers used two separate questionnaires to gather the opinions of 10 higher education institutions and 250 students on quality of education service delivery in the first quarter of this year from the Pune district of Maharashtra state. The collected data was analyzed with the support of Microsoft Excel software packages. The findings of the analysis confirmed that institutions were confidently provided academic activity reflecting their goals and objectives with highly qualified faculty through an eclectic approach with the support of research with ample focus on library and community services. Students also expressed different wavering perceptions on the academic activity, faculty communication skills, motivation and mentoring etc. Only 33 and 80% students uttered positively about the faculty subject knowledge and sports, and infrastructure facilities provided by the institution. In a nut shell, both institutions and students insisted for more constructive role from the Internal Quality Assurance Cell (IQAC in protecting the quality of higher education.

  2. Degradation of Akebono solar cell panels and variation of proton radiation belt

    Science.gov (United States)

    Ishikawa, H.; Miyake, W.; Matsuoka, A.

    2011-12-01

    We analyze long-term variation of electric current generated by Akebono solar cell panels (SCPI) and investigate how solar cell panels have been affected by space radiation. SCPI decreased slowly to about 7A in 2009 from 13A in 1989. The long-term decrease is probably due to various space radiations (Total Dose Effect). Therefore, we compare the decrease of solar cell output with solar proton flux measured by GOES satellites on GEO and with flux of trapped radiation from NASA's models (AP8 and AE8). We find a fair correlation between the decrease rate of solar cell output and trapped proton flux (above 10MeV) from the radiation model. However, we also find a few intervals of poor correlation, for an example, after a large geomagnetic storm occurred in March 1991, which suggests that stable proton radiation belt can be changed drastically for some special occasions.

  3. Telomerase antagonist imetelstat increases radiation sensitivity in esophageal squamous cell carcinoma.

    Science.gov (United States)

    Wu, Xuping; Zhang, Jing; Yang, Sijun; Kuang, Zhihui; Tan, Guolei; Yang, Gang; Wei, Qichun; Guo, Zhigang

    2017-01-13

    The morbidity and mortality of esophageal cancer is one of the highest around the world and the principal therapeutic method is radiation. Thus, searching for sensitizers with lower toxicity and higher efficiency to improve the efficacy of radiation therapy is critical essential. Our research group has previously reported that imetelstat, the thio-phosphoramidate oligonucleotide inhibitor of telomerase, can decrease cell proliferation and colony formation ability as well as increase DNA breaks induced by radiation in esophageal cancer cells. Further study in this project showed that imetelstat significantly sensitized esophageal cancer cells to radiation in vitro. Later study showed that imetelstat leads to increased cell apoptosis. We also measured the expression level of several DNA repair and apoptosis signaling proteins. pS345 CHK1, γ-H2AX, p53 and caspase3 expression were up-regulated in imetelstat treated cells, identifying these factors as molecular markers. Mouse in vivo model using imetelstat at clinically achievable concentrations and fractionated irradiation scheme yielded results demonstrating radiosensitization effect. Finally, TUNEL assay, caspase 3 and Ki67 staining in tumor tissue proved that imetelstat sensitized esophageal cancer to radiation in vivo through promoting cell apoptosis and inhibiting cell proliferation. Our study supported imetelstat increase radiation sensitivity of esophageal squamous cell carcinoma through inducing cell apoptosis and the specific inhibitor of telomerase might serve as a potential novel therapeutic tool for esophageal squamous cell carcinoma therapy.

  4. Mechanisms of Low Dose Radiation-induced T helper Cell Function

    Energy Technology Data Exchange (ETDEWEB)

    Gridley, Daila S.

    2008-10-31

    photons. Over the course of this research, tissues other than spleens were archived and with funding obtained from other sources, including the Department of Radiation Medicine at the Loma Linda University Medical Center, some additional assays were performed. Furthermore, groups of additional mice were included that were pre-exposed to low-dose photons before irradiating with acute photons, protons, and simulated solar particle event (SPE) protons. Hence, the original support together with the additional funding for our research led to generation of much valuable information that was originally not anticipated. Some of the data has already resulted in published articles, manuscripts in review, and a number of presentations at scientific conferences and workshops. Difficulties in reliable and reproducible quantification of secreted cytokines using multi-plex technology delayed completion of this study for a period of time. However, final analyses of the remaining data are currently being performed and should result in additional publications and presentations in the near future. Some of the most notable conclusions, thus far, are briefly summarized below: - Distribution of leukocytes were dependent upon cell type, radiation quality, body compartment analyzed, and time after exposure. Low-dose protons tended to have less effect on numbers of major leukocyte populations and T cell subsets compared to low-dose photons. - The patterns of gene and cytokine expression in CD4+ T cells after protracted low-dose irradiation were significantly modified and highly dependent upon the total dose and time after exposure. - Patterns of gene and cytokine expression differed substantially among groups exposed to low-dose photons versus low-dose protons; differences were also noted among groups exposed to much higher doses of photons, protons, and simulated SPE protons. - Some measurements indicated that exposure to low-dose photon radiation, especially 0.01 Gy, significantly

  5. Tinnitus and cell phones: the role of electromagnetic radiofrequency radiation

    Directory of Open Access Journals (Sweden)

    Luisa Nascimento Medeiros

    2016-02-01

    Full Text Available ABSTRACT INTRODUCTION: Tinnitus is a multifactorial condition and its prevalence has increased on the past decades. The worldwide progressive increase of the use of cell phones has exposed the peripheral auditory pathways to a higher dose of electromagnetic radiofrequency radiation (EMRFR. Some tinnitus patients report that the abusive use of mobiles, especially when repeated in the same ear, might worsen ipsilateral tinnitus. OBJECTIVE: The aim of this study was to evaluate the available evidence about the possible causal association between tinnitus and exposure to electromagnetic waves. METHODS: A literature review was performed searching for the following keywords: tinnitus, electromagnetic field, mobile phones, radio frequency, and electromagnetic hypersensitivity. We selected 165 articles that were considered clinically relevant in at least one of the subjects. RESULTS: EMRFR can penetrate exposed tissues and safety exposure levels have been established. These waves provoke proved thermogenic effects and potential biological and genotoxic effects. Some individuals are more sensitive to electromagnetic exposure (electrosensitivity, and thus, present earlier symptoms. There may be a common pathophysiology between this electrosensitivity and tinnitus. CONCLUSION: There are already reasonable evidences to suggest caution for using mobile phones to prevent auditory damage and the onset or worsening of tinnitus.

  6. Health-related quality of life in sickle cell disease.

    Science.gov (United States)

    Panepinto, Julie A

    2008-07-01

    Advances in drug therapy, hematopoietic stem cell transplantation, and technology have improved the morbidity and survival for those with sickle cell disease. The effect of this modern therapy on the health-related quality of life (HRQL) of those with sickle cell disease is not known. HRQL provides an assessment of how an illness, its complications, and its treatment are experienced by a patient. This review will examine prior work in HRQL in sickle cell disease and the rationale for utilizing HRQL as an outcome to measure impact of treatment. In addition, issues to consider when reporting HRQL will be presented.

  7. Impact of the scout view orientation on the radiation exposure and image quality in thoracic and abdominal CT

    Energy Technology Data Exchange (ETDEWEB)

    Suntharalingam, S.; Wetter, A.; Guberina, N.; Theysohn, J.; Ringelstein, A.; Schlosser, T.; Forsting, M.; Nassenstein, K. [University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany)

    2016-11-15

    To assess the impact of the scout view orientation on radiation exposure and image quality in thoracoabdominal CT, when automated tube voltage selection (ATVS) and automated tube current modulation (ATCM) are used in combination with scan planning on a single scout view. Fifty patients underwent two thoracoabdominal CT examinations, one planned on an anteroposterior scout view, one planned on a lateral scout view. Both examinations included contrast-enhanced imaging of chest (CH) and abdomen (AB) and non-contrast-enhanced imaging of the liver (LI). For all examinations the same imaging protocol was used on the same dual-source CT scanner. The radiation exposure was recorded and objective as well as visual image quality was assessed for all examinations. The median dose-length product was significantly lower in scans planned on a lateral scout view (CH: 179 vs. 218 mGy*cm, LI: 148 vs. 178 mGy*cm, AB: 324 vs. 370 mGy*cm, p < 0.0001). Objective image quality was marginal lower in scans planned on a lateral scout view, whereas the visual image quality was rated as equal. At the tested radiation doses, the orientation of the scout view has a significant impact on the radiation exposure but no clinically relevant impact on the image quality. (orig.)

  8. Cell/Tissue Culture Radiation Exposure Facility Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the development of automated systems to improve radiobiology research capabilities at NASA Space Radiation Laboratory (NSRL) at Brookhaven National...

  9. Successful imiquimod treatment of multiple basal cell carcinomas after radiation therapy for Hodgkin's disease.

    Science.gov (United States)

    Beyeler, Mirjam; Urosevic, Mirjana; Pestalozzi, Bernhard; Dummer, Reinhard

    2005-01-01

    We present a case of a 55-year-old male patient who developed five basal cell carcinomas 23 years after radiation therapy of Hodgkin's disease. In 1980 he received radiation therapy twice. Due to relapses, he was treated with aggressive polychemotherapy and underwent autologous stem cell transplantation, which then led to complete remission. Until now he is in complete remission. However, multiple superficial basal cell carcinomas have developed on irradiation fields that have been successfully treated by imiquimod.

  10. Ionizing Radiation Promotes the Migratory and Invasive Potential of Lung Cancer Cells by Different Mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Jin Nyoung; Kang, Ga Young; Um, Hong Duck [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2008-05-15

    Although radiation therapy is a major therapeutic modality for cancer treatment, previous reports have suggested that ionizing radiation (IR) can promote the invasive and metastatic potential of cancer cells. It was consistently reported that IR can induce certain types of matrix metalloproteinases, which are critical to the degradation of extracellular matrix. Given that the motility of cancer cells is an additional requirement for their metastasis, this study investigated whether IR can also influence the migratory potential of cancer cells.

  11. Quality Research in Radiation Oncology Analysis of Clinical Performance Measures in the Management of Gastric Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, Karyn A., E-mail: goodmank@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Khalid, Najma [Quality Research in Radiation Oncology, American College of Radiology Clinical Research Center, Philadelphia, Pennsylvania (United States); Kachnic, Lisa A. [Department of Radiation Oncology, Boston University Medical Center, Boston, Massachusetts (United States); Minsky, Bruce D. [Department of Radiation Oncology, University of Texas MD, Anderson Cancer Center, Houston, Texas (United States); Crozier, Cheryl; Owen, Jean B. [Quality Research in Radiation Oncology, American College of Radiology Clinical Research Center, Philadelphia, Pennsylvania (United States); Devlin, Phillip M. [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women' s Hospital, Boston, Massachusetts (United States); Thomas, Charles R. [Department of Radiation Medicine, Knight Cancer Institute at the Oregon Health and Science University, Portland, Oregon (United States)

    2013-02-01

    Background: The specific aim was to determine national patterns of radiation therapy (RT) practice in patients treated for stage IB-IV (nonmetastatic) gastric cancer (GC). Methods and Materials: A national process survey of randomly selected US RT facilities was conducted which retrospectively assessed demographics, staging, geographic region, practice setting, and treatment by using on-site record review of eligible GC cases treated from 2005 to 2007. Three clinical performance measures (CPMs), (1) use of computed tomography (CT)-based treatment planning; (2) use of dose volume histograms (DVHs) to evaluate RT dose to the kidneys and liver; and (3) completion of RT within the prescribed time frame; and emerging quality indicators, (i) use of intensity modulated RT (IMRT); (ii) use of image-guided tools (IGRT) other than CT for RT target delineation; and (iii) use of preoperative RT, were assessed. Results: CPMs were computed for 250 eligible patients at 45 institutions (median age, 62 years; 66% male; 60% Caucasian). Using 2000 American Joint Committee on Cancer criteria, 13% of patients were stage I, 29% were stage II, 32% were stage IIIA, 10% were stage IIIB, and 12% were stage IV. Most patients (43%) were treated at academic centers, 32% were treated at large nonacademic centers, and 25% were treated at small to medium sized facilities. Almost all patients (99.5%) underwent CT-based planning, and 75% had DVHs to evaluate normal tissue doses to the kidneys and liver. Seventy percent of patients completed RT within the prescribed time frame. IMRT and IGRT were used in 22% and 17% of patients, respectively. IGRT techniques included positron emission tomography (n=20), magnetic resonance imaging (n=1), respiratory gating and 4-dimensional CT (n=22), and on-board imaging (n=10). Nineteen percent of patients received preoperative RT. Conclusions: This analysis of radiation practice patterns for treating nonmetastatic GC indicates widespread adoption of CT

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-01-15

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

  13. Th Cell Gene Expression and Function in Response to Low Dose and Acute Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Daila S. Gridley, PhD

    2012-03-30

    FINAL TECHNICAL REPORT Supported by the Low Dose Radiation Research Program, Office of Science U.S. Department of Energy Grant No. DE-FG02-07ER64345 Project ID: 0012965 Award Register#: ER64345 Project Manager: Noelle F. Metting, Sc.D. Phone: 301-903-8309 Division SC-23.2 noelle.metting@science.doe.gov Submitted March 2012 To: https://www.osti.gov/elink/241.3.jsp Title: Th Cell Gene Expression and Function in Response to Low Dose and Acute Radiation PI: Daila S. Gridley, Ph.D. Human low dose radiation data have been derived primarily from studies of space and airline flight personnel, nuclear plant workers and others exposed occupationally, as well as victims in the vicinity of atomic bomb explosions. The findings remain inconclusive due to population inconsistencies and complex interactions among total dose, dose rate, radiation quality and age at exposure. Thus, safe limits for low dose occupational irradiation are currently based on data obtained with doses far exceeding the levels expected for the general population and health risks have been largely extrapolated using the linear-nonthreshold dose-response model. The overall working hypothesis of the present study is that priming with low dose, low-linear energy transfer (LET) radiation can ameliorate the response to acute high-dose radiation exposure. We also propose that the efficacy of low-dose induced protection will be dependent upon the form and regimen of the high-dose exposure: photons versus protons versus simulated solar particle event protons (sSPE). The emphasis has been on gene expression and function of CD4+ T helper (Th) lymphocytes harvested from spleens of whole-body irradiated C57BL/6 mice, a strain that provides the genetic background for many genetically engineered strains. Evaluations of the responses of other selected cells, tissues such as skin, and organs such as lung, liver and brain were also initiated (partially funded by other sources). The long-term goal is to provide information

  14. Fractionated radiation exposure amplifies the radioresistant nature of prostate cancer cells

    Science.gov (United States)

    McDermott, N.; Meunier, A.; Mooney, B.; Nortey, G.; Hernandez, C.; Hurley, S.; Lynam-Lennon, N.; Barsoom, S. H.; Bowman, K. J.; Marples, B.; Jones, G. D. D.; Marignol, L.

    2016-01-01

    The risk of recurrence following radiation therapy remains high for a significant number of prostate cancer patients. The development of in vitro isogenic models of radioresistance through exposure to fractionated radiation is an increasingly used approach to investigate the mechanisms of radioresistance in cancer cells and help guide improvements in radiotherapy standards. We treated 22Rv1 prostate cancer cells with fractionated 2 Gy radiation to a cumulative total dose of 60 Gy. This process selected for 22Rv1-cells with increased clonogenic survival following subsequent radiation exposure but increased sensitivity to Docetaxel. This RR-22Rv1 cell line was enriched in S-phase cells, less susceptible to DNA damage, radiation-induced apoptosis and acquired enhanced migration potential, when compared to wild type and aged matched control 22Rv1 cells. The selection of radioresistant cancer cells during fractionated radiation therapy may have implications in the development and administration of future targeted therapy in conjunction with radiation therapy. PMID:27703211

  15. Glutathione depletion and carbon ion radiation potentiate clustered DNA lesions, cell death and prevent chromosomal changes in cancer cells progeny.

    Science.gov (United States)

    Hanot, Maïté; Boivin, Anthony; Malésys, Céline; Beuve, Michaël; Colliaux, Anthony; Foray, Nicolas; Douki, Thierry; Ardail, Dominique; Rodriguez-Lafrasse, Claire

    2012-01-01

    Poor local control and tumor escape are of major concern in head-and-neck cancers treated by conventional radiotherapy or hadrontherapy. Reduced glutathione (GSH) is suspected of playing an important role in mechanisms leading to radioresistance, and its depletion should enable oxidative stress insult, thereby modifying the nature of DNA lesions and the subsequent chromosomal changes that potentially lead to tumor escape.This study aimed to highlight the impact of a GSH-depletion strategy (dimethylfumarate, and L-buthionine sulfoximine association) combined with carbon ion or X-ray irradiation on types of DNA lesions (sparse or clustered) and the subsequent transmission of chromosomal changes to the progeny in a radioresistant cell line (SQ20B) expressing a high endogenous GSH content. Results are compared with those of a radiosensitive cell line (SCC61) displaying a low endogenous GSH level. DNA damage measurements (γH2AX/comet assay) demonstrated that a transient GSH depletion in resistant SQ20B cells potentiated the effects of irradiation by initially increasing sparse DNA breaks and oxidative lesions after X-ray irradiation, while carbon ion irradiation enhanced the complexity of clustered oxidative damage. Moreover, residual DNA double-strand breaks were measured whatever the radiation qualities. The nature of the initial DNA lesions and amount of residual DNA damage were similar to those observed in sensitive SCC61 cells after both types of irradiation. Misrepaired or unrepaired lesions may lead to chromosomal changes, estimated in cell progeny by the cytome assay. Both types of irradiation induced aberrations in nondepleted resistant SQ20B and sensitive SCC61 cells. The GSH-depletion strategy prevented the transmission of aberrations (complex rearrangements and chromosome break or loss) in radioresistant SQ20B only when associated with carbon ion irradiation. A GSH-depleting strategy combined with hadrontherapy may thus have considerable advantage in the

  16. Glutathione depletion and carbon ion radiation potentiate clustered DNA lesions, cell death and prevent chromosomal changes in cancer cells progeny.

    Directory of Open Access Journals (Sweden)

    Maïté Hanot

    Full Text Available Poor local control and tumor escape are of major concern in head-and-neck cancers treated by conventional radiotherapy or hadrontherapy. Reduced glutathione (GSH is suspected of playing an important role in mechanisms leading to radioresistance, and its depletion should enable oxidative stress insult, thereby modifying the nature of DNA lesions and the subsequent chromosomal changes that potentially lead to tumor escape.This study aimed to highlight the impact of a GSH-depletion strategy (dimethylfumarate, and L-buthionine sulfoximine association combined with carbon ion or X-ray irradiation on types of DNA lesions (sparse or clustered and the subsequent transmission of chromosomal changes to the progeny in a radioresistant cell line (SQ20B expressing a high endogenous GSH content. Results are compared with those of a radiosensitive cell line (SCC61 displaying a low endogenous GSH level. DNA damage measurements (γH2AX/comet assay demonstrated that a transient GSH depletion in resistant SQ20B cells potentiated the effects of irradiation by initially increasing sparse DNA breaks and oxidative lesions after X-ray irradiation, while carbon ion irradiation enhanced the complexity of clustered oxidative damage. Moreover, residual DNA double-strand breaks were measured whatever the radiation qualities. The nature of the initial DNA lesions and amount of residual DNA damage were similar to those observed in sensitive SCC61 cells after both types of irradiation. Misrepaired or unrepaired lesions may lead to chromosomal changes, estimated in cell progeny by the cytome assay. Both types of irradiation induced aberrations in nondepleted resistant SQ20B and sensitive SCC61 cells. The GSH-depletion strategy prevented the transmission of aberrations (complex rearrangements and chromosome break or loss in radioresistant SQ20B only when associated with carbon ion irradiation. A GSH-depleting strategy combined with hadrontherapy may thus have considerable

  17. Distal airway epithelial progenitor cells are radiosensitive to High-LET radiation

    Science.gov (United States)

    McConnell, Alicia M.; Konda, Bindu; Kirsch, David G.; Stripp, Barry R.

    2016-01-01

    Exposure to high-linear energy transfer (LET) radiation occurs in a variety of situations, including charged particle radiotherapy, radiological accidents, and space travel. However, the extent of normal tissue injury in the lungs following high-LET radiation exposure is unknown. Here we show that exposure to high-LET radiation led to a prolonged loss of in vitro colony forming ability by airway epithelial progenitor cells. Furthermore, exposure to high-LET radiation induced clonal expansion of a subset of progenitor cells in the distal airway epithelium. Clonal expansion following high-LET radiation exposure was correlated with elevated progenitor cell apoptosis, persistent γ-H2AX foci, and defects in mitotic progression of distal airway progenitors. We discovered that the effects of high-LET radiation exposure on progenitor cells occur in a p53-dependent manner. These data show that high-LET radiation depletes the distal airway progenitor pool by inducing cell death and loss of progenitor function, leading to clonal expansion. Importantly, high-LET radiation induces greater long-term damage to normal lung tissue than the relative equivalent dose of low-LET γ-rays, which has implications in therapeutic development and risk assessment. PMID:27659946

  18. Net radiative forcing and air quality responses to regional CO emission reductions

    Directory of Open Access Journals (Sweden)

    M. M. Fry

    2013-05-01

    Full Text Available Carbon monoxide (CO emissions influence global and regional air quality and global climate change by affecting atmospheric oxidants and secondary species. We simulate the influence of halving anthropogenic CO emissions globally and individually from 10 regions on surface and tropospheric ozone, methane, and aerosol concentrations using a global chemical transport model (MOZART-4 for the year 2005. Net radiative forcing (RF is then estimated using the GFDL (Geophysical Fluid Dynamics Laboratory standalone radiative transfer model. We estimate that halving global CO emissions decreases global annual average concentrations of surface ozone by 0.45 ppbv, tropospheric methane by 73 ppbv, and global annual net RF by 36.1 mW m−2, nearly equal to the sum of changes from the 10 regional reductions. Global annual net RF per unit change in emissions and the 100 yr global warming potential (GWP100 are estimated as −0.124 mW m−2 (Tg CO−1 and 1.34, respectively, for the global CO reduction, and ranging from −0.115 to −0.131 mW m−2 (Tg CO−1 and 1.26 to 1.44 across 10 regions, with the greatest sensitivities for regions in the tropics. The net RF distributions show widespread cooling corresponding to the O3 and CH4 decreases, and localized positive and negative net RFs due to changes in aerosols. The strongest annual net RF impacts occur within the tropics (28° S–28° N followed by the northern midlatitudes (28° N–60° N, independent of reduction region, while the greatest changes in surface CO and ozone concentrations occur within the reduction region. Some regional reductions strongly influence the air quality in other regions, such as East Asia, which has an impact on US surface ozone that is 93% of that from North America. Changes in the transport of CO and downwind ozone production clearly exceed the direct export of ozone from each reduction region. The small variation in CO GWPs among world regions suggests that future international

  19. Radiofrequency electromagnetic radiation from cell phone causes defective testicular function in male Wistar rats.

    Science.gov (United States)

    Oyewopo, A O; Olaniyi, S K; Oyewopo, C I; Jimoh, A T

    2017-03-06

    Cell phones have become an integral part of everyday life. As cell phone usage has become more widespread, concerns have increased regarding the harmful effects of radiofrequency electromagnetic radiation from these devices. The current study was undertaken to investigate the effects of the emitted radiation by cell phones on testicular histomorphometry and biochemical analyses. Adult male Wistar rats weighing 180-200 g were randomly allotted to control, group A (switched off mode exposure), group B (1-hr exposure), group C (2-hr exposure) and group D (3-hr exposure). The animals were exposed to radiofrequency electromagnetic radiation of cell phone for a period of 28 days. Histomorphometry, biochemical and histological investigations were carried out. The histomorphometric parameters showed no significant change (p electromagnetic radiation of cell phone leads to defective testicular function that is associated with increased oxidative stress and decreased gonadotropic hormonal profile.

  20. Automation and Intensity Modulated Radiation Therapy for Individualized High-Quality Tangent Breast Treatment Plans

    Energy Technology Data Exchange (ETDEWEB)

    Purdie, Thomas G., E-mail: Tom.Purdie@rmp.uhn.on.ca [Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Techna Institute, University Health Network, Toronto, Ontario (Canada); Dinniwell, Robert E.; Fyles, Anthony [Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Sharpe, Michael B. [Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Techna Institute, University Health Network, Toronto, Ontario (Canada)

    2014-11-01

    Purpose: To demonstrate the large-scale clinical implementation and performance of an automated treatment planning methodology for tangential breast intensity modulated radiation therapy (IMRT). Methods and Materials: Automated planning was used to prospectively plan tangential breast IMRT treatment for 1661 patients between June 2009 and November 2012. The automated planning method emulates the manual steps performed by the user during treatment planning, including anatomical segmentation, beam placement, optimization, dose calculation, and plan documentation. The user specifies clinical requirements of the plan to be generated through a user interface embedded in the planning system. The automated method uses heuristic algorithms to define and simplify the technical aspects of the treatment planning process. Results: Automated planning was used in 1661 of 1708 patients receiving tangential breast IMRT during the time interval studied. Therefore, automated planning was applicable in greater than 97% of cases. The time for treatment planning using the automated process is routinely 5 to 6 minutes on standard commercially available planning hardware. We have shown a consistent reduction in plan rejections from plan reviews through the standard quality control process or weekly quality review multidisciplinary breast rounds as we have automated the planning process for tangential breast IMRT. Clinical plan acceptance increased from 97.3% using our previous semiautomated inverse method to 98.9% using the fully automated method. Conclusions: Automation has become the routine standard method for treatment planning of tangential breast IMRT at our institution and is clinically feasible on a large scale. The method has wide clinical applicability and can add tremendous efficiency, standardization, and quality to the current treatment planning process. The use of automated methods can allow centers to more rapidly adopt IMRT and enhance access to the documented

  1. Mesenchymal stem cell therapy for acute radiation syndrome:Innovative medical approaches in military medicine

    Institute of Scientific and Technical Information of China (English)

    Erik B.Eaton Jr.; Timothy R.Varney

    2014-01-01

    After a radiological or nuclear event, acute radiation syndrome (ARS) will present complex medical challenges that could involve the treatment of hundreds to thousands of patients. Current medical doctrine is based on limited clinical data and remains inadequate. Efforts to develop medical innovations that address ARS complications are unlikely to be generated by the industry because of market uncertainties specific to this type of injury. A prospective strategy could be the integration of cellular therapy to meet the medical demands of ARS. The most clinically advanced cellular therapy to date is the administration of mesenchymal stem cells (MSCs). Results of currently published investigations describing MSC safety and efficacy in a variety of injury and disease models demonstrate the unique qualities of this reparative cell population in adapting to the specific requirements of the damaged tissue in which the cells integrate. This report puts forward a rationale for the further evaluation of MSC therapy to address the current unmet medical needs of ARS. We propose that the exploration of this novel therapy for the treatment of the multivariate complications of ARS could be of invaluable benefit to military medicine.

  2. Quantitative phase imaging for cell culture quality control.

    Science.gov (United States)

    Kastl, Lena; Isbach, Michael; Dirksen, Dieter; Schnekenburger, Jürgen; Kemper, Björn

    2017-03-06

    The potential of quantitative phase imaging (QPI) with digital holographic microscopy (DHM) for quantification of cell culture quality was explored. Label-free QPI of detached single cells in suspension was performed by Michelson interferometer-based self-interference DHM. Two pancreatic tumor cell lines were chosen as cellular model and analyzed for refractive index, volume, and dry mass under varying culture conditions. Firstly, adequate cell numbers for reliable statistics were identified. Then, to characterize the performance and reproducibility of the method, we compared results from independently repeated measurements and quantified the cellular response to osmolality changes of the cell culture medium. Finally, it was demonstrated that the evaluation of QPI images allows the extraction of absolute cell parameters which are related to cell layer confluence states. In summary, the results show that QPI enables label-free imaging cytometry, which provides novel complementary integral biophysical data sets for sophisticated quantification of cell culture quality with minimized sample preparation. © 2017 International Society for Advancement of Cytometry.

  3. Pharmacologically blocking p53-dependent apoptosis protects intestinal stem cells and mice from radiation.

    Science.gov (United States)

    Wang, Xinwei; Wei, Liang; Cramer, Julie M; Leibowitz, Brian J; Judge, Colleen; Epperly, Michael; Greenberger, Joel; Wang, Fengchao; Li, Linheng; Stelzner, Matthias G; Dunn, James C Y; Martin, Martin G; Lagasse, Eric; Zhang, Lin; Yu, Jian

    2015-04-10

    Exposure to high levels of ionizing radiation (IR) leads to debilitating and dose-limiting gastrointestinal (GI) toxicity. Using three-dimensional mouse crypt culture, we demonstrated that p53 target PUMA mediates radiation-induced apoptosis via a cell-intrinsic mechanism, and identified the GSK-3 inhibitor CHIR99021 as a potent radioprotector. CHIR99021 treatment improved Lgr5+ cell survival and crypt regeneration after radiation in culture and mice. CHIR99021 treatment specifically blocked apoptosis and PUMA induction and K120 acetylation of p53 mediated by acetyl-transferase Tip60, while it had no effect on p53 stabilization, phosphorylation or p21 induction. CHIR99021 also protected human intestinal cultures from radiation by PUMA but not p21 suppression. These results demonstrate that p53 posttranslational modifications play a key role in the pathological and apoptotic response of the intestinal stem cells to radiation and can be targeted pharmacologically.

  4. Clustered DNA damages induced in human hematopoietic cells by low doses of ionizing radiation

    Science.gov (United States)

    Sutherland, Betsy M.; Bennett, Paula V.; Cintron-Torres, Nela; Hada, Megumi; Trunk, John; Monteleone, Denise; Sutherland, John C.; Laval, Jacques; Stanislaus, Marisha; Gewirtz, Alan

    2002-01-01

    Ionizing radiation induces clusters of DNA damages--oxidized bases, abasic sites and strand breaks--on opposing strands within a few helical turns. Such damages have been postulated to be difficult to repair, as are double strand breaks (one type of cluster). We have shown that low doses of low and high linear energy transfer (LET) radiation induce such damage clusters in human cells. In human cells, DSB are about 30% of the total of complex damages, and the levels of DSBs and oxidized pyrimidine clusters are similar. The dose responses for cluster induction in cells can be described by a linear relationship, implying that even low doses of ionizing radiation can produce clustered damages. Studies are in progress to determine whether clusters can be produced by mechanisms other than ionizing radiation, as well as the levels of various cluster types formed by low and high LET radiation.

  5. Effect of radiation on prostacyclin (PGI2) production by cultured endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Eldor, A.; Vlodavsky, I.; Hyam, E.; Atzmon, R.; Fuks, Z.

    1983-02-01

    The effect of ionizing irradiation on the synthesis of prostacyclin (PGI2) by cultured bovine aortic endothelial cells was determined. PGI2 was measured in the culture medium by a radioimmunoassay for 6-Keto PGF1 alpha. Two phenomena were observed following irradiation: a) Cells which suffered an immediate radiation damage (1000-5000 rads) released high quantities of PGI2 to the culture medium. This was due to a de novo synthesis of PGI2 stimulated by radiation induced cellular damage, since pretreatment with aspirin of the endothelial cell monolayers resulted in a marked inhibition of PGI2 release following irradiation. b) Metabolically active cells which remained confluent and firmly attached to the culture dish following single, low and intermediate doses (200-1200 rads) radiation, exhibited a marked decrease in their capacity to synthesize PGI2 upon exposure to various stimuli of the arachidonic acid cascade. Similar results were observed with cells treated with fractionated radiation. The quantities of PGI2 produced by the endothelial cells decreased as a function of the dose of radiation and time interval between irradiation and subsequent stimulation. The effect of radiation on PGI2 production by the vascular endothelium may be relevant to the development of radiation induced capillary occlusions, and the enhancement of atherosclerotic lesions in large vessels.

  6. Organotypic culture in three dimensions prevents radiation-induced transformation in human lung epithelial cells

    Science.gov (United States)

    El-Ashmawy, Mariam; Coquelin, Melissa; Luitel, Krishna; Batten, Kimberly; Shay, Jerry W.

    2016-08-01

    The effects of radiation in two-dimensional (2D) cell culture conditions may not recapitulate tissue responses as modeled in three-dimensional (3D) organotypic culture. In this study, we determined if the frequency of radiation-induced transformation and cancer progression differed in 3D compared to 2D culture. Telomerase immortalized human bronchial epithelial cells (HBECs) with shTP53 and mutant KRas expression were exposed to various types of radiation (gamma, +H, 56Fe) in either 2D or 3D culture. After irradiation, 3D structures were dissociated and passaged as a monolayer followed by measurement of transformation, cell growth and expression analysis. Cells irradiated in 3D produced significantly fewer and smaller colonies in soft agar than their 2D-irradiated counterparts (gamma P = 0.0004 +H P = 0.049 56Fe P < 0.0001). The cell culture conditions did not affect cell killing, the ability of cells to survive in a colony formation assay, and proliferation rates after radiation—implying there was no selection against cells in or dissociated from 3D conditions. However, DNA damage repair and apoptosis markers were increased in 2D cells compared to 3D cells after radiation. Ideally, expanding the utility of 3D culture will allow for a better understanding of the biological consequences of radiation exposure.

  7. The impact of the International Atomic Energy Agency (IAEA) program on radiation and tissue banking in Uruguay: development of tissues quality control and quality management system in the National Multi-Tissue Bank of Uruguay.

    Science.gov (United States)

    Alvarez, I; Morales Pedraza, Jorge; Saldías, M C; Pérez Campos, H; Wodowóz, O; Acosta, María; Vicentino, W; Silva, W; Rodríguez, G; Machín, D; Alvarez, O

    2009-05-01

    BNOT was created and regulated in 1977 and started its operation in 1978 according to the Decree No. 86/1977. By the Decree 248/005 is transformed in the National Institute of Donation and Transplantation of Cells, Tissues and Organs (Instituto Nacional de Donación y Trasplante de Células, Tejidos y Organos--INDT). The organisation has been operating within the State University Medical School and the Public Health Secretary and it is the governmental organisation responsible for the regulation, policy and management of donation and transplantation in Uruguay. By the Decree 160/2006 is responsible for human cells and tissues regulation too. The participation of the INDT in the IAEA program facilitated the introduction of the radiation sterilisation technique for the first time in the country. The radiation sterilisation of tissues processed by INDT (ex BNOT), was initially carried out in the 60 Cobalt Industrial Plant in the National Atomic Energy Commission of Argentina and now is carried out in INDT, using a Gamma Cell 220 Excel, which was provided by the IAEA through the national project URU/7/005. The results of the implementation of tissues, quality control and quality management system, are showed.

  8. 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

  9. Radiation resistance of thin-film solar cells for space photovoltaic power

    Science.gov (United States)

    Woodyard, James R.; Landis, Geoffrey A.

    1991-01-01

    Copper indium diselenide, cadmium telluride, and amorphous silicon alloy solar cells have achieved noteworthy performance and are currently being studied for space power applications. Cadmium sulfide cells had been the subject of much effort but are no longer considered for space applications. A review is presented of what is known about the radiation degradation of thin film solar cells in space. Experimental cadmium telluride and amorphous silicon alloy cells are reviewed. Damage mechanisms and radiation induced defect generation and passivation in the amorphous silicon alloy cell are discussed in detail due to the greater amount of experimental data available.

  10. Evaluation of LiF:Mg,Ti (TLD-100 for Intraoperative Electron Radiation Therapy Quality Assurance.

    Directory of Open Access Journals (Sweden)

    Raffaele Liuzzi

    Full Text Available Purpose of the present work was to investigate thermoluminescent dosimeters (TLDs response to intraoperative electron radiation therapy (IOERT beams. In an IOERT treatment, a large single radiation dose is delivered with a high dose-per-pulse electron beam (2-12 cGy/pulse during surgery. To verify and to record the delivered dose, in vivo dosimetry is a mandatory procedure for quality assurance. The TLDs feature many advantages such as a small detector size and close tissue equivalence that make them attractive for IOERT as in vivo dosimeters.LiF:Mg,Ti dosimeters (TLD-100 were irradiated with different IOERT electron beam energies (5, 7 and 9 MeV and with a 6 MV conventional photon beam. For each energy, the TLDs were irradiated in the dose range of 0-10 Gy in step of 2 Gy. Regression analysis was performed to establish the response variation of thermoluminescent signals with dose and energy.The TLD-100 dose-response curves were obtained. In the dose range of 0-10 Gy, the calibration curve was confirmed to be linear for the conventional photon beam. In the same dose region, the quadratic model performs better than the linear model when high dose-per-pulse electron beams were used (F test; p<0.05.This study demonstrates that the TLD dose response, for doses ≤10 Gy, has a parabolic behavior in high dose-per-pulse electron beams. TLD-100 can be useful detectors for IOERT patient dosimetry if a proper calibration is provided.

  11. Evaluating Cell Processes, Quality, and Biomarkers in Pluripotent Stem Cells Using Video Bioinformatics.

    Science.gov (United States)

    Zahedi, Atena; On, Vincent; Lin, Sabrina C; Bays, Brett C; Omaiye, Esther; Bhanu, Bir; Talbot, Prue

    2016-01-01

    There is a foundational need for quality control tools in stem cell laboratories engaged in basic research, regenerative therapies, and toxicological studies. These tools require automated methods for evaluating cell processes and quality during in vitro passaging, expansion, maintenance, and differentiation. In this paper, an unbiased, automated high-content profiling toolkit, StemCellQC, is presented that non-invasively extracts information on cell quality and cellular processes from time-lapse phase-contrast videos. Twenty four (24) morphological and dynamic features were analyzed in healthy, unhealthy, and dying human embryonic stem cell (hESC) colonies to identify those features that were affected in each group. Multiple features differed in the healthy versus unhealthy/dying groups, and these features were linked to growth, motility, and death. Biomarkers were discovered that predicted cell processes before they were detectable by manual observation. StemCellQC distinguished healthy and unhealthy/dying hESC colonies with 96% accuracy by non-invasively measuring and tracking dynamic and morphological features over 48 hours. Changes in cellular processes can be monitored by StemCellQC and predictions can be made about the quality of pluripotent stem cell colonies. This toolkit reduced the time and resources required to track multiple pluripotent stem cell colonies and eliminated handling errors and false classifications due to human bias. StemCellQC provided both user-specified and classifier-determined analysis in cases where the affected features are not intuitive or anticipated. Video analysis algorithms allowed assessment of biological phenomena using automatic detection analysis, which can aid facilities where maintaining stem cell quality and/or monitoring changes in cellular processes are essential. In the future StemCellQC can be expanded to include other features, cell types, treatments, and differentiating cells.

  12. Air quality and radiative forcing impacts of anthropogenic volatile organic compound emissions from ten world regions

    Directory of Open Access Journals (Sweden)

    M. M. Fry

    2013-08-01

    Full Text Available Non-methane volatile organic compounds (NMVOCs influence air quality and global climate change through their effects on secondary air pollutants and climate forcers. Here we simulate the air quality and radiative forcing (RF impacts of changes in ozone, methane, and sulfate from halving anthropogenic NMVOC emissions globally and from 10 regions individually, using a global chemical transport model and a standalone radiative transfer model. Halving global NMVOC emissions decreases global annual average tropospheric methane and ozone by 36.6 ppbv and 3.3 Tg, respectively, and surface ozone by 0.67 ppbv. All regional reductions slow the production of PAN, resulting in regional to intercontinental PAN decreases and regional NOx increases. These NOx increases drive tropospheric ozone increases nearby or downwind of source regions in the Southern Hemisphere (South America, Southeast Asia, Africa, and Australia. Some regions' NMVOC emissions contribute importantly to air pollution in other regions, such as East Asia, Middle East, and Europe, whose impact on US surface ozone is 43%, 34%, and 34% of North America's impact. Global and regional NMVOC reductions produce widespread negative net RFs (cooling across both hemispheres from tropospheric ozone and methane decreases, and regional warming and cooling from changes in tropospheric ozone and sulfate (via several oxidation pathways. The total global net RF for NMVOCs is estimated as 0.0277 W m−2 (~1.8% of CO2 RF since the preindustrial. The 100 yr and 20 yr global warming potentials (GWP100, GWP20 are 2.36 and 5.83 for the global reduction, and 0.079 to 6.05 and −1.13 to 18.9 among the 10 regions. The NMVOC RF and GWP estimates are generally lower than previously modeled estimates, due to differences among models in ozone, methane, and sulfate sensitivities, and the climate forcings included in each estimate. Accounting for a~fuller set of RF contributions may change the relative magnitude of each

  13. Solar ultraviolet radiation from cancer induction to cancer prevention: solar ultraviolet radiation and cell biology.

    Science.gov (United States)

    Tuorkey, Muobarak J

    2015-09-01

    Although decades have elapsed, researchers still debate the benefits and hazards of solar ultraviolet radiation (UVR) exposure. On the one hand, humans derive most of their serum 25-hydroxycholecalciferol [25(OH)D3], which has potent anticancer activity, from solar UVB radiation. On the other hand, people are more aware of the risk of cancer incidence associated with harmful levels of solar UVR from daily sunlight exposure. Epidemiological data strongly implicate UV radiation exposure as a major cause of melanoma and other cancers, as UVR promotes mutations in oncogenes and tumor-suppressor genes. This review highlights the impact of the different mutagenic effects of solar UVR, along with the cellular and carcinogenic challenges with respect to sun exposure.

  14. Non-Destructive Detection and Separation of Radiation Damaged Cells in Miniaturized, Inexpensive Device Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There is a clear and well-identified need for rapid, efficient, non-destructive detection and isolation of radiation damaged cells. Available commercial technologies...

  15. Exosomes Derived from Squamous Head and Neck Cancer Promote Cell Survival after Ionizing Radiation.

    Science.gov (United States)

    Mutschelknaus, Lisa; Peters, Carsten; Winkler, Klaudia; Yentrapalli, Ramesh; Heider, Theresa; Atkinson, Michael John; Moertl, Simone

    2016-01-01

    Exosomes are nanometer-sized extracellular vesicles that are believed to function as intercellular communicators. Here, we report that exosomes are able to modify the radiation response of the head and neck cancer cell lines BHY and FaDu. Exosomes were isolated from the conditioned medium of irradiated as well as non-irradiated head and neck cancer cells by serial centrifugation. Quantification using NanoSight technology indicated an increased exosome release from irradiated compared to non-irradiated cells 24 hours after treatment. To test whether the released exosomes influence the radiation response of other cells the exosomes were transferred to non-irradiated and irradiated recipient cells. We found an enhanced uptake of exosomes isolated from both irradiated and non-irradiated cells by irradiated recipient cells compared to non-irradiated recipient cells. Functional analyses by exosome transfer indicated that all exosomes (from non-irradiated and irradiated donor cells) increase the proliferation of non-irradiated recipient cells and the survival of irradiated recipient cells. The survival-promoting effects are more pronounced when exosomes isolated from irradiated compared to non-irradiated donor cells are transferred. A possible mechanism for the increased survival after irradiation could be the increase in DNA double-strand break repair monitored at 6, 8 and 10 h after the transfer of exosomes isolated from irradiated cells. This is abrogated by the destabilization of the exosomes. Our results demonstrate that radiation influences both the abundance and action of exosomes on recipient cells. Exosomes transmit prosurvival effects by promoting the proliferation and radioresistance of head and neck cancer cells. Taken together, this study indicates a functional role of exosomes in the response of tumor cells to radiation exposure within a therapeutic dose range and encourages that exosomes are useful objects of study for a better understanding of tumor

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

    Institute of Scientific and Technical Information of China (English)

    张鸿源; 王兰金; 等

    1995-01-01

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

  17. Hypofractionated radiation therapy for the treatment of feline facial squamous cell carcinoma; Hypofractionated radiation therapy for the treatment of feline facial squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, S.C.S.; Corgozinho, K.B.; Holguin, P.G.; Ferreira, A.M.R., E-mail: simonecsc@gmail.co [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Carvalho, L.A.V. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil); Canary, P.C.; Reisner, M. [Hospital Universitario Clementino Fraga Filho (HUCFF/UFRJ), Rio de Janeiro, RJ (Brazil); Pereira, A.N.; Souza, H.J.M. [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil)

    2010-07-01

    The efficacy of hypofractionated radiation protocol for feline facial squamous cell carcinoma was evaluated. Hypofractionated radiation therapy was applied to five cats showing single or multiple facial squamous cell carcinomas, in a total of ten histologically confirmed neoplastic lesions. Of the lesions, two were staged as T{sub 1}, four as T{sub 2}, two as T{sub 3}, and two as T{sub 4}. The animals were submitted to four radiation fractions from 7.6 to 10 grays each, with one week intervals. The equipment was a linear accelerator with electrons beam. The cats were evaluated weekly during the treatment and 30 and 60 days after the end of the radiation therapy. In this study, 40% of the lesions had complete remission, 40% partial remission, and 20% did not respond to the treatment. Response rates were lower as compared to other protocols previously used. However, hypofractionated radiation protocol was considered safe for feline facial squamous cell carcinoma. (author)

  18. Pain management and quality of life in sickle cell disease.

    Science.gov (United States)

    Howard, Jo; Thomas, Veronica J; Rawle, Heather M

    2009-08-01

    Sickle cell disease (SCD) is the most common inherited disease worldwide and is responsible for a massive health burden. Its main clinical feature is severe pain that is unpredictable and recurrent, and this, in addition to the other acute and chronic features of SCD, may have a huge impact on the quality of life of both the patient and their families and carers. We consider medical and psychological methods of pain management in SCD, drawing on recently published UK Standards of Care, and also consider the effect of SCD on quality of life.

  19. Gamma evaluation combined with isocenter optimal matching in intensity modulated radiation therapy quality assurance

    Science.gov (United States)

    Bak, Jino; Choi, Jin Hwa; Park, Suk Won; Park, Kwangwoo; Park, Sungho

    2015-12-01

    Two-dimensional (2D) dose comparisons are widely performed by using a gamma evaluation with patient-specific intensity modulated radiation therapy quality assurance (IMRT QA) or dose delivery quality assurance (DQA). In this way, a pass/fail determination is made for a particular treatment plan. When gamma evaluation results are close to the failure criterion, the pass/fail decision may change applying a small shift to the center of the 2D dose distribution. In this study, we quantitatively evaluated the meaning of such a small relative shift in a 2D dose distribution comparison. In addition, we propose the use of a small shift for a pass/fail criterion in gamma analysis, where the concept of isocenter optimal matching (IOM) is applied to IMRT QA of 20 patients. Gamma evaluations were performed to compare two dose distributions, one with and the other without IOM. In-house software was developed in C++ in order to find IOM values including both translational and rotational shifts. Upon gamma evaluation failure, further investigation was initiated using IOM. In this way, three groups were categorized: group 1 for `pass' on gamma evaluation, group 21 for `fail' on the gamma evaluation and `pass' on the gamma the evaluation with IOM, and group 22 for `fail' on the both gamma evaluations and the IOM calculation. IOM results revealed that some failures could be considered as a `pass'. In group 21, 88.98% (fail) of the averaged gamma pass rate changed to 90.45% (pass) when IOM was applied. On average, a ratio of γ ≥ 1 was reduced by 11.06% in 20 patients. We propose that gamma evaluations that do not pass with a rate of 85% to 90% may be augmented with IOM to reveal a potential pass result.

  20. Longitudinal analysis of quality of life in patients receiving conformal radiation therapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Geinitz, Hans; Thamm, Reinhard; Scholz, Christian; Heinrich, Christine; Prause, Nina; Kerndl, Simone; Molls, Michael; Zimmermann, Frank B. [Dept. of Radiotherapy and Radiooncology, Technische Univ. Muenchen (Germany); Keller, Monika [Psychooncology Section, Dept. of Psychosomatic and General Clinical Medicine, Univ. Hospital, Heidelberg (Germany); Busch, Raymonde [Inst. of Medical Statistics and Epidemiology, Technische Univ. Muenchen (Germany)

    2010-01-15

    Purpose: To prospectively assess quality of life (QoL) in patients receiving conformal radiation therapy (CRT) for prostate cancer. Patients and Methods: 78 men with definitive CRT for prostate cancer were entered into the study. Patients were assessed before CRT, at 40 and 60 Gy, and 2, 12 and 24 months after the end of treatment. QoL was assessed using the EORTC Quality of Life Questionnaire C30 and the prostate module PR25. Changes in mean QoL scores with time of {>=} 10 points were considered clinically relevant. Results: Global QoL did not change statistically significant during CRT and was slightly above baseline levels during follow-up. CRT had a statistically significant negative short-term impact on role functioning, fatigue, and PR25 urinary symptoms. The scores recovered within 2 months to 1 year after CRT. Emotional functioning and social functioning scores slightly increased during and after CRT. Role functioning decreased by > 10 points at 60 Gy and urinary symptoms decreased by > 10 points at 40 and 60 Gy. All other differences were < 10 points. A high number of concomitant diseases and having no children were negative pretreatment predictors for long-term global QoL. Conclusion: Definitive CRT for prostate cancer does not compromise global QoL during therapy and up to 2 years after treatment. It has a limited negative effect on role functioning, urinary symptoms and, to a lesser extent, on fatigue with restitution within 2 months to 1 year after treatment. (orig.)

  1. The role of autophagy in sensitizing malignant glioma cells to radiation therapy

    Institute of Scientific and Technical Information of China (English)

    Wenzhuo Zhuang; Zhenghong Qin; Zhongqin Liang

    2009-01-01

    Malignant gliomas representthe majority of primary brain tumors.The current standard treatments for malignant gliomas include surgical resection,radiation therapy,and chemotherapy.Radiotherapy,a standard adjuvant therapy,confers some survival advantages,but resistance of the glioma cells to the efficacy of radiation limits the success of the treatment.The mechanisms underlying glioma cell radioresistance have remained elusive.Autophagy is a protein degradation system characterized by a prominent formation of double-membrane vesicles in the cytoplasm.Recent studies suggest that autophagy may be important in the regulation of cancer development and progression and in determining the response of tumor cells to anticancer therapy.Also,autophagy is a novel response of glioma cells to ionizing radiation.Autophagic cell death is considered programmed cell death type Ⅱ,whereas apoptosis is programmed cell death type Ⅰ.These two types of cell death are predominantly distinctive,but many studies demonstrate a cross-talk between them.Whether autophagy in cancer cells causes death or protects cells is controversial.The regulatory pathways of autophagy share several molecules.P13K/Akt/Mtor,DNA-PK,tumor suppressor genes, mitochondrial damage,and lysosome may play important roles in radiation-induced autophagy in glioma cells.Recently,a highly tumorigenic glioma tumor subpopulation,termed cancer stem cell or tumor-initiating cell,has been shown to promote therapeutic resistance.This review summarizes the main mediators associated with radiation-induced autophagy in malignant glioma cells and discusses the implications of the cancer stem cell hypothesis for the development of future therapies for brain tumors.

  2. Quality of Intensity Modulated Radiation Therapy Treatment Plans Using a (60)Co Magnetic Resonance Image Guidance Radiation Therapy System

    DEFF Research Database (Denmark)

    Wooten, H Omar; Green, Olga; Yang, Min

    2015-01-01

    PURPOSE: This work describes a commercial treatment planning system, its technical features, and its capabilities for creating (60)Co intensity modulated radiation therapy (IMRT) treatment plans for a magnetic resonance image guidance radiation therapy (MR-IGRT) system. METHODS AND MATERIALS......: The ViewRay treatment planning system (Oakwood Village, OH) was used to create (60)Co IMRT treatment plans for 33 cancer patients with disease in the abdominal, pelvic, thorax, and head and neck regions using physician-specified patient-specific target coverage and organ at risk (OAR) objectives. Backup......% prescription reference isodoses, respectively, and heterogeneity was on average 4% greater. Comparisons of OAR mean dose showed generally better sparing with linac plans in the low-dose range organs with mean doses >20 Gy. The mean doses for all (60)Co plan OARs were within...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

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

  4. Evaluation of quality of mango cultivar Tommy Atkins radiated with greater degree of maturity

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Josenilda M. da, E-mail: jmnilda@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Santos, Marilia C.G. dos; Maciel, Maria Ines S., E-mail: marines@ufrpe.br [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil); Villar, Heldio P., E-mail: hpvillar@cnen.gov.br [Escola Politecnica de Pernambuco, Recife, PE (Brazil)

    2011-07-01

    The effects of ionizing radiation at doses of 0.5 and 1.0 kGy were evaluated in mango cultivar Tommy Atkins when harvested at maturation stage showing yellow flesh and skin color more red than green, representing four degree of maturation at commercial scale. The fruits were stored for 21 days at 12 degree C and sensory evaluated after that period as its external appearance, internal appearance, acidic taste, sweet taste, mellow flavor, aroma, texture and succulence of the flesh, by a team of ten trained judges. Physic chemical analysis of the main characteristics of fruits quality were also performed in the pulp at the end of storage. The results of sensory analysis revealed that the doses used did not damaged the sensory characteristics of mango fruit and that they received a dose of 0.5 kGy showed higher acceptance for most sensory attributes evaluated. The physic chemical characteristics showed no significant differences between the doses, except the amount of ascorbic acid that decreased progressively with increasing doses. Application of this method is viable for mango cultivar Tommy Atkins when taken with a higher degree of maturity and was safe for the external market and sensory acceptable. (author)

  5. A framework for automated contour quality assurance in radiation therapy including adaptive techniques

    Science.gov (United States)

    Altman, M. B.; Kavanaugh, J. A.; Wooten, H. O.; Green, O. L.; DeWees, T. A.; Gay, H.; Thorstad, W. L.; Li, H.; Mutic, S.

    2015-07-01

    Contouring of targets and normal tissues is one of the largest sources of variability in radiation therapy treatment plans. Contours thus require a time intensive and error-prone quality assurance (QA) evaluation, limitations which also impair the facilitation of adaptive radiotherapy (ART). Here, an automated system for contour QA is developed using historical data (the ‘knowledge base’). A pilot study was performed with a knowledge base derived from 9 contours each from 29 head-and-neck treatment plans. Size, shape, relative position, and other clinically-relevant metrics and heuristically derived rules are determined. Metrics are extracted from input patient data and compared against rules determined from the knowledge base; a computer-learning component allows metrics to evolve with more input data, including patient specific data for ART. Nine additional plans containing 42 unique contouring errors were analyzed. 40/42 errors were detected as were 9 false positives. The results of this study imply knowledge-based contour QA could potentially enhance the safety and effectiveness of RT treatment plans as well as increase the efficiency of the treatment planning process, reducing labor and the cost of therapy for patients.

  6. Afatinib increases sensitivity to radiation in non-small cell lung cancer cells with acquired EGFR T790M mutation.

    Science.gov (United States)

    Zhang, Shirong; Zheng, Xiaoliang; Huang, Haixiu; Wu, Kan; Wang, Bing; Chen, Xufeng; Ma, Shenglin

    2015-03-20

    Afatinib is a second-generation of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor and has shown a significant clinical benefit in non-small cell lung cancer (NSCLC) patients with EGFR-activating mutations. However, the potential therapeutic effects of afatinib combining with other modalities, including ionizing radiation (IR), are not well understood. In this study, we developed a gefitinib-resistant cell subline (PC-9-GR) with a secondary EGFR mutation (T790M) from NSCLC PC-9 cells after chronic exposures to increasing doses of gefitinib. The presence of afatinib significantly increases the cell killing effect of radiation in PC-9-GR cells harboring acquired T790M, but not in H1975 cells with de novo T790M or in H460 cells that express wild-type EGFR. In PC-9-GR cells, afatinib remarkable blocks baseline of EGFR and ERK phosphorylations, and causes delay of IR-induced AKT phosphorylation. Afatinib treatment also leads to increased apoptosis and suppressed DNA damage repair in irradiated PC-9-GR cells, and enhanced tumor growth inhibition when combined with IR in PC-9-GR xenografts. Our findings suggest a potential therapeutic impact of afatinib as a radiation sensitizer in lung cancer cells harboring acquired T790M mutation, providing a rationale for a clinical trial with combination of afatinib and radiation in NSCLCs with EGFR T790M mutation.

  7. Quality management in radiation protection: Introduction of a quality management system at PSI, Switzerland; Qualitaetsmanagement im Strahlenschutz: Erfahrungen beim Aufbau eines Systems im PSI

    Energy Technology Data Exchange (ETDEWEB)

    Baehrle, H. [Paul Scherrer Inst., Villigen PSI (Switzerland). Abt. Strahlenhygiene

    1997-10-01

    The introduction of a Quality Management System for the radiation protection organization of the Paul-Scherrer-Institute at Villigen/Switzerland is substantiated and described. Hints are given for an effective procedure during the initiation phase. (orig.) [Deutsch] Die Einfuehrung eines Qualitaetsmanagementsystems fuer den Strahlenschutz am Paul-Scherrer-Institut in Villigen/CH wird begruendet und beschrieben. Dabei werden Tips fuer das erfolgreiche Vorgehen waehrend der Aufbauphase gegeben. (orig.)

  8. A mathematical model of radiation carcinogenesis with induction of genomic instability and cell death.

    Science.gov (United States)

    Ohtaki, M; Niwa, O

    2001-11-01

    We developed a mathematical model of carcinogenesis that incorporates genomic instability, a feature characterized by long-term destabilization of the genome in irradiated cells that leads to an increase in cancer risk in the exposed individuals at the cancer-prone age. This model also considers the induction of cell death, another important effect of radiation on cells. It is assumed that cell killing by radiation may occur at all stages of the carcinogenic process. The resulting model can explain not only the paradoxical relationship between low mutation rates and high cancer incidence but also the low-order dose-response relationship of cancer risk.

  9. Neurotoxicity of human neural cells induced by space radiation: in vitro risk assessment and countermeasure

    Science.gov (United States)

    Guida, P.; Vazquez, M.; Kim, A.

    As the duration of space missions increases the potential for neurological damage to astronauts resulting from exposure to radiation also increases To explore the cytotoxic effects of low and high LET radiation on cells of the central nervous system we utilized a model in vitro system consisting of a human neuronal progenitor cell line NT2 and its terminally differentiated derivative hNT neurons We found that exposure to numerous forms of ionizing radiation induced cell detachment necrosis and apoptosis in time dose and LET dependent manners From the slopes of the dose-response curves we calculated RBE values for each form of heavy ion radiation A sequential field of 1 GeV n protons and iron ions induced apoptosis to a greater extent than either ion alone and the time between hits was also an important determining factor In addition cycling neuronal progenitor cells underwent a dramatic G2 phase specific cell cycle delay within 6 hours following exposure to either low or high LET radiation The molecular effects of HZE radiation were also investigated with an emphasis on the cell stress response protein p53 Heavy ion radiation induced expression of p53 in a time and dose dependent manner in both neuronal progenitor and mature neuronal cells Furthermore several post-translational modifications to the p53 protein were detected 2 hours after exposure to gamma rays Experiments incorporating pifithrin- alpha a small molecule inhibitor of p53 suggest that induction of both apoptosis and the cell cycle delay in human NT2 cells is

  10. Radiation Dose-effects on Cell Cycle, Apoptosis, and Marker Expression of Ataxia Telangiectasia-Heterozygous Human Breast Epithelial Cells

    Science.gov (United States)

    Cruz, A.; Bors, K.; Jansen, H.; Richmond, R.

    2003-01-01

    Ataxia-telangiectasia (A-T) is a radiation-sensitive genetic condition. AT-heterozygous human mammary epithelial cells (HMEC) were irradiated using a Cs137 source in order to compare cell cycle, apoptosis, and marker expression responses across 3 radiation doses. No differences in cell cycle and apoptosis were found with any of the radiation doses used (30, 60, and 90 rads) compared with the unirradiated control (0 rad). At the same doses, however, differences were found in marker expression, such as keratin 18 (kl8), keratin 14 (k14), insulin-like growth factor I receptor (IGF-IR), and connexin 43 (cx43). This may indicate that radiation sensitivity in the heterozygous state may be initiated through signal transduction responses.

  11. Cell-permeable intrinsic cellular inhibitors of apoptosis protect and rescue intestinal epithelial cells from radiation-induced cell death.

    Science.gov (United States)

    Matsuzaki-Horibuchi, Shiori; Yasuda, Takeshi; Sakaguchi, Nagako; Yamaguchi, Yoshihiro; Akashi, Makoto

    2015-01-01

    One of the important mechanisms for gastrointestinal (GI) injury following high-dose radiation exposure is apoptosis of epithelial cells. X-linked inhibitor of apoptosis (XIAP) and cellular IAP2 (cIAP2) are intrinsic cellular inhibitors of apoptosis. In order to study the effects of exogenously added IAPs on apoptosis in intestinal epithelial cells, we constructed bacterial expression plasmids containing genes of XIAP (full-length, BIR2 domain and BIR3-RING domain with and without mutations of auto-ubiquitylation sites) and cIAP2 proteins fused to a protein-transduction domain (PTD) derived from HIV-1 Tat protein (TAT) and purified these cell-permeable recombinant proteins. When the TAT-conjugated IAPs were added to rat intestinal epithelial cells IEC6, these proteins were effectively delivered into the cells and inhibited apoptosis, even when added after irradiation. Our results suggest that PTD-mediated delivery of IAPs may have clinical potential, not only for radioprotection but also for rescuing the GI system from radiation injuries.

  12. Elucidation of changes in molecular signalling leading to increased cellular transformation in oncogenically progressed human bronchial epithelial cells exposed to radiations of increasing LET.

    Science.gov (United States)

    Ding, Liang-Hao; Park, Seongmi; Xie, Yang; Girard, Luc; Minna, John D; Story, Michael D

    2015-09-01

    The early transcriptional response and subsequent induction of anchorage-independent growth after exposure to particles of high Z and energy (HZE) as well as γ-rays were examined in human bronchial epithelial cells (HBEC3KT) immortalised without viral oncogenes and an isogenic variant cell line whose p53 expression was suppressed but that expressed an active mutant K-RAS(V12) (HBEC3KT-P53KRAS). Cell survival following irradiation showed that HBEC3KT-P53KRAS cells were more radioresistant than HBEC3KT cells irrespective of the radiation species. In addition, radiation enhanced the ability of the surviving HBEC3KT-P53RAS cells but not the surviving HBEC3KT cells to grow in anchorage-independent fashion (soft agar colony formation). HZE particle irradiation was far more efficient than γ-rays at rendering HBEC3KT-P53RAS cells permissive for soft agar growth. Gene expression profiles after radiation showed that the molecular response to radiation for HBEC3KT-P53RAS, similar to that for HBEC3KT cells, varies with radiation quality. Several pathways associated with anchorage independent growth, including the HIF-1α, mTOR, IGF-1, RhoA and ERK/MAPK pathways, were over-represented in the irradiated HBEC3KT-P53RAS cells compared to parental HBEC3KT cells. These results suggest that oncogenically progressed human lung epithelial cells are at greater risk for cellular transformation and carcinogenic risk after ionising radiation, but particularly so after HZE radiations. These results have implication for: (i) terrestrial radiation and suggests the possibility of enhanced carcinogenic risk from diagnostic CT screens used for early lung cancer detection; (ii) enhanced carcinogenic risk from heavy particles used in radiotherapy; and (iii) for space radiation, raising the possibility that astronauts harbouring epithelial regions of dysplasia or hyperplasia within the lung that contain oncogenic changes, may have a greater risk for lung cancers based upon their exposure to heavy

  13. Involvement of ERK-Nrf-2 signaling in ionizing radiation induced cell death in normal and tumor cells.

    Directory of Open Access Journals (Sweden)

    Raghavendra S Patwardhan

    Full Text Available Prolonged oxidative stress favors tumorigenic environment and inflammation. Oxidative stress may trigger redox adaptation mechanism(s in tumor cells but not normal cells. This may increase levels of intracellular antioxidants and establish a new redox homeostasis. Nrf-2, a master regulator of battery of antioxidant genes is constitutively activated in many tumor cells. Here we show that, murine T cell lymphoma EL-4 cells show constitutive and inducible radioresistance via activation of Nrf-2/ERK pathway. EL-4 cells contained lower levels of ROS than their normal counterpart murine splenic lymphocytes. In response to radiation, the thiol redox circuits, GSH and thioredoxin were modified in EL-4 cells. Pharmacological inhibitors of ERK and Nrf-2 significantly enhanced radiosensitivity and reduced clonogenic potential of EL-4 cells. Unirradiated lymphoma cells showed nuclear accumulation of Nrf-2, upregulation of its dependent genes and protein levels. Interestingly, MEK inhibitor abrogated its nuclear translocation suggesting role of ERK in basal and radiation induced Nrf-2 activation in tumor cells. Double knockdown of ERK and Nrf-2 resulted in higher sensitivity to radiation induced cell death as compared to individual knockdown cells. Importantly, NF-kB which is reported to be constitutively active in many tumors was not present at basal levels in EL-4 cells and its inhibition did not influence radiosensitivity of EL-4 cells. Thus our results reveal that, tumor cells which are subjected to heightened oxidative stress employ master regulator cellular redox homeostasis Nrf-2 for prevention of radiation induced cell death. Our study reveals the molecular basis of tumor radioresistance and highlights role of Nrf-2 and ERK.

  14. Optimal per cent by weight of elements in diagnostic quality radiation shielding materials.

    Science.gov (United States)

    Ashayer, Sahar; Askari, Mansur; Afarideh, Hossein

    2012-04-01

    By increasing the usage of radiation in all aspects of lives, the human body is becoming more exposed to ionising radiation. The purpose of this study is to find the optimal radiation shielding materials to protect humans from the radiation hazards of radiation. Some elements and compounds such as Ag, Bi, Pb, W, BaSO(4) were chosen on the basis of their attenuation coefficients and other characteristics to produce optimised radiation shielding compounds. Multi-objective non-dominated sorting genetic algorithm-II was used to optimise the weight fraction of the elements in compounds based on the dose equivalent rate, shield weight and cost. Consequently, sets of suitable compounds were obtained depending on various applications for energy 0.06 and 0.15 MeV. In addition, optimised lead free compounds were obtained. The results presented in a series of graphs should enable radiation shield designers to choose an appropriate combination according to their requirements.

  15. Durability Quality Research of Concrete Containing Solar PV Cells

    Directory of Open Access Journals (Sweden)

    Chao Sao-Jeng

    2015-01-01

    Full Text Available In this article we demonstrated the study results of durability quality of concrete containing waste solar PV cells. The study used alkali activator to improve the activity of alkali-activated materials in solar PV cells so as to replace Portland cement as binder in concrete. By using sodium hydroxide as an alkali-activator, a high-pH environment is generated to excite the binding characteristics of alkali-activated materials in solar PV cells, and thus develops better durability of the mixes. The conclusions were made on effect of this cement replacement. As a result, we identified the durability for those of 16 concrete specimens predefined and made to consider various possible control factors. The conclusions also depicted that all experiments but the drying shrinkage may be helpful with the suitable use of control factors as far as concerning the recycled solar PV cells for mixing in concrete. In other words, the durability quality of concrete may be partially unacceptable of containing solar PV cells.

  16. A simple model of space radiation damage in GaAs solar cells

    Science.gov (United States)

    Wilson, J. W.; Stith, J. J.; Stock, L. V.

    1983-01-01

    A simple model is derived for the radiation damage of shallow junction gallium arsenide (GaAs) solar cells. Reasonable agreement is found between the model and specific experimental studies of radiation effects with electron and proton beams. In particular, the extreme sensitivity of the cell to protons stopping near the cell junction is predicted by the model. The equivalent fluence concept is of questionable validity for monoenergetic proton beams. Angular factors are quite important in establishing the cell sensitivity to incident particle types and energies. A fluence of isotropic incidence 1 MeV electrons (assuming infinite backing) is equivalent to four times the fluence of normal incidence 1 MeV electrons. Spectral factors common to the space radiations are considered, and cover glass thickness required to minimize the initial damage for a typical cell configuration is calculated. Rough equivalence between the geosynchronous environment and an equivalent 1 MeV electron fluence (normal incidence) is established.

  17. Radiation-Sensitising Effects of Antennapedia Proteins (ANTP-SmacN7 on Tumour Cells

    Directory of Open Access Journals (Sweden)

    Li Qing Du

    2013-12-01

    Full Text Available The objective of this study was to investigate the underlying mechanisms behind the radiation-sensitising effects of the antennapedia proteins (ANTP-smacN7 fusion protein on tumour cells. ANTP-SmacN7 fusion proteins were synthesised, and the ability of this fusion protein to penetrate cells was observed. Effects of radiation on the expression of X-linked inhibitor of apoptosis protein (XIAP were detected by western blotting. The radiation-sensitising effects of ANTP-SmacN7 fusion proteins were observed by a clonogenic assay. The effects of drugs and radiation on tumour cell apoptosis were determined using Annexin V/FITC double staining. Changes in caspase-8, caspase-9 and caspase-3 were detected by western blot before and after ANTP-SmacN7 inhibition of XIAP. The ANTP-SmacN7 fusion protein could enter and accumulate in cells; in vitro XIAP expression of radiation-induced tumour cells was negatively correlated with tumour radiosensitivity. The ANTP-SmacN7 fusion protein promoted tumour cell apoptosis through the activation of caspase3. ANTP-SmacN7 fusion protein may reduce tumour cell radioresistance by inducing caspase3 activation.

  18. INHIBITION AND RADIATION SENSITIZING EFFECT OF INDOLEACETIC ACID COMBINED WITH HORSERADISH PEROXIDASE ON HELA CELLS

    Institute of Scientific and Technical Information of China (English)

    宋丽萍; 黄辰; 邱曙东; 王月英; 张健; 陈顺昌; 马军; 王全丽

    2004-01-01

    Objective To observe the inhibition and radiation-sensitizing effect of Indoleacetic acid (IAA) combined with horseradish peroxidase(HRP)on Hela cells. Methods Hela cells were cultured in vitro and classified into control group, drug group incubated with different doses of IAA(30, 60, 90μmol·L-1) plus 1.2μg·mL-1 HRP, radiation group (6MV-X, 4Gy ) and group of radiation plus IAA plus HRP(same dose as above). All the above were treated for 24-96 hours.The growth inhibition, radiation-sensitizing effect were observed with methyl thiazolyl tetrazolium (MTT) photocolorimetric assay and trypan blue dye assay. The-effect on cell proliferation cycle was determined by flow cytometry. Results The antiproliferation activities showed a significant time-effect and dose-effect relationship to some extent after Hela cells were treated with IAA combined with HRP. The group of radiation plus 60μmol·L-1 IAA plus 1.2μg·mL-1 HRP and radiation plus 90μmol·L-1 IAA plus 1.2μg·mL-1 HRP showed an obvious radiation sensitizing effect. After treatment with 90μmol·L-1 IAA plus 1.2μg·mL-1 HRP for 72 hours, the determination of cell cycle showed that the percentages of the cells on stages G2-M and S were all higher than those of the control group. For the group of radiation plus IAA combined with HRP, the percentages of the cells on stages G2-M were higher than those of the radiation group. Conclusion The above findings suggest that IAA combined with HRP has an inhibitive and killing effect on Hela cells. The effect was stronger during the cell cycles of G2-M and S. It also has a radiation sensitizing effect. Its mechanism might be that Hela cells were blocked on stages G2-M, and it presents a collaborative killing effect during miototic time.

  19. Radiation Therapy

    Science.gov (United States)

    Radiation therapy is a cancer treatment. It uses high doses of radiation to kill cancer cells and stop them from ... half of all cancer patients receive it. The radiation may be external, from special machines, or internal, ...

  20. High-Quality T2-Weighted 4-Dimensional Magnetic Resonance Imaging for Radiation Therapy Applications

    Energy Technology Data Exchange (ETDEWEB)

    Du, Dongsu [Department of Radiation Oncology, Washington University School of Medicine, Saint Louis, Missouri (United States); Caruthers, Shelton D. [Philips Healthcare, Cleveland, Ohio (United States); Glide-Hurst, Carri [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan (United States); Low, Daniel A. [Department of Radiation Oncology, University of California-Los Angeles, Los Angeles, California (United States); Li, H. Harold; Mutic, Sasa [Department of Radiation Oncology, Washington University School of Medicine, Saint Louis, Missouri (United States); Hu, Yanle, E-mail: Hu.Yanle@mayo.edu [Department of Radiation Oncology, Washington University School of Medicine, Saint Louis, Missouri (United States); Department of Radiation Oncology, Mayo Clinic in Arizona, Phoenix, Arizona (United States)

    2015-06-01

    Purpose: The purpose of this study was to improve triggering efficiency of the prospective respiratory amplitude-triggered 4-dimensional magnetic resonance imaging (4DMRI) method and to develop a 4DMRI imaging protocol that could offer T2 weighting for better tumor visualization, good spatial coverage and spatial resolution, and respiratory motion sampling within a reasonable amount of time for radiation therapy applications. Methods and Materials: The respiratory state splitting (RSS) and multi-shot acquisition (MSA) methods were analytically compared and validated in a simulation study by using the respiratory signals from 10 healthy human subjects. The RSS method was more effective in improving triggering efficiency. It was implemented in prospective respiratory amplitude-triggered 4DMRI. 4DMRI image datasets were acquired from 5 healthy human subjects. Liver motion was estimated using the acquired 4DMRI image datasets. Results: The simulation study showed the RSS method was more effective for improving triggering efficiency than the MSA method. The average reductions in 4DMRI acquisition times were 36% and 10% for the RSS and MSA methods, respectively. The human subject study showed that T2-weighted 4DMRI with 10 respiratory states, 60 slices at a spatial resolution of 1.5 × 1.5 × 3.0 mm{sup 3} could be acquired in 9 to 18 minutes, depending on the individual's breath pattern. Based on the acquired 4DMRI image datasets, the ranges of peak-to-peak liver displacements among 5 human subjects were 9.0 to 12.9 mm, 2.5 to 3.9 mm, and 0.5 to 2.3 mm in superior-inferior, anterior-posterior, and left-right directions, respectively. Conclusions: We demonstrated that with the RSS method, it was feasible to acquire high-quality T2-weighted 4DMRI within a reasonable amount of time for radiation therapy applications.

  1. Ionizing radiation induces tumor cell lysyl oxidase secretion

    DEFF Research Database (Denmark)

    Shen, Colette J; Sharma, Ashish; Vuong, Dinh-Van;

    2014-01-01

    BACKGROUND: Ionizing radiation (IR) is a mainstay of cancer therapy, but irradiation can at times also lead to stress responses, which counteract IR-induced cytotoxicity. IR also triggers cellular secretion of vascular endothelial growth factor, transforming growth factor beta and matrix...

  2. Survival and signaling changes in antigen presenting cell subsets after radiation

    Science.gov (United States)

    Parker, Jennifer Janell

    Radiation therapy is a widely used cancer treatment that has the potential to influence anti-tumor immune responses. Both myeloablative and non-myeloablative radiation are often used as part of preparatory regimens for hematopoetic stem cell transplantation, in combination with other chemotherapy or immuno-modulatory (e.g. Anti-thymocyte globulin (ATG)) therapies for both cytotoxic and immune modulatory purposes. However, the mechanisms responsible for the effect of radiation on antigen presenting cell (APC) responsiveness and radioresistance are poorly understood. The first studies described in this thesis were designed to identify and characterize early radiation-induced signaling changes in antigen presenting cells and to determine the effects of these signaling changes on APC receptor expression and function. The NFkappaB pathway in antigen presenting cells was chosen for study because it is activated by radiation in a wide range of other cell types and plays a vital role in the maintenance and regulation of the immune system. The effects of therapeutically relevant doses radiation (2 and 20 Gy) were compared at various timepoints in the human monocytic cell line (U937) using phospho-flow cytometry staining methods and cytometric analysis. These studies demonstrated that radiation-induced changes in the phosphorylation state of NFkappaB family members that were p53 independent. However, these changes were dependent upon activation of ATM in response to single or double-stranded breaks in DNA, as shown in experiments using an inhibitor of ATM and ATM siRNA knockdown U937 cells. In addition, studies examining the effect of radiation on co-stimulatory receptors with and without inhibition of the NFkappaB pathway via phospho-flow cytometry revealed that radiation-induced phosphorylation of NEMO promoted the activation and functional maturation of U937 cells. Furthermore, functional studies using both phospho-flow cytometry and/or mixed lymphocyte reactions to

  3. Impact of Asian aerosols on air quality over the United States: A perspective from aerosol-cloud-radiation coupling

    Science.gov (United States)

    Tao, Z.; Yu, H.; Chin, M.

    2013-12-01

    It has well been established, through satellite/ground observations, that dust and aerosols from various Asian sources can travel across the Pacific and reach North America (NA) at least on episode bases. Once reaching NA, these inflow aerosols would compete with local emissions to influence atmospheric composition and air quality over the United States (US). The previous studies, typically based on one or multiple satellite measurements in combination with global/regional model simulations, suggest that the impact of Asian dust/aerosols on US air quality tend to be small since most inflow aerosols stay aloft. On the other hand, aerosols affect many key meteorological processes that will ultimately channel down to impact air quality. Aerosols absorb and scatter solar radiation that change the atmospheric stability, thus temperature, wind, and planetary boundary layer structure that would directly alter air quality. Aerosols can serve as cloud condensation nuclei and ice nuclei to modify cloud properties and precipitation that would also affect aerosol removal and concentration. This indirect impact of Asian aerosol inflow on US air quality may be substantial and need to be investigated. This study employs the NASA Unified WRF (NU-WRF) to address the question from the aerosol-radiation-cloud interaction perspective. The simulation period was selected from April to June of 2010 during which the Asian dust continuously reached NA based on CALIPSO satellite observation. The preliminary results show that the directly-transported Asian aerosol increases surface PM2.5 concentration by less than 2 μg/m3 over the west coast areas of US, and the aerosol-radiation-cloud feedback has a profound effect on air quality over the central to eastern US. A more detailed analysis links this finding to a series of meteorological conditions modified by aerosol effects.

  4. Effect of ionizing radiation on transcription of colorectal cancer MDR1 gene of HCT-8 cells

    Institute of Scientific and Technical Information of China (English)

    Xiao-Feng Li; Lin Ma; Jing Lu; Li-Xia Kong; Xiao-Hua Long; Su-Huan Liao; Bao-Rong Chi

    2013-01-01

    Objective: To discuss effect of ionizing radiation on transcription of colorectal cancer multidrug resistance (MDR) 1 gene of HCT-8 cells. Methods: Total RNA was extracted by guanidine thiocyanate one-step method. Northern blot was applied to detect transcription level of MDR1 gene. The expression of P-gp protein was detected by flow cytometry. Results: The expression of MDR1 of normal colorectal cancer HCT-8 cells was low. It was increased by 8.35 times under stimulus with 2 Gy. When treated with low doses in advance, high expressed MDR was decreased significantly under 0.05, 0.1 Gy, which was 69.00%, 62.89% in 2 Gy group and 5.77 times, 5.25 times in sham irradiation group. No obvious difference was detected between (0.2+2) Gy group and 2 Gy group. Compared with sham irradiation group, the percentage of P-gp positive cells after radiation of a high 2 Gy dose was increased significantly (P<0.01). When treated with high radiation dose following low radiation dose (0.05 Gy, 0.1 Gy) in advance, the percentage of P-gp positive cells were also increased significantly. The percentage of P-gp positive cells were increased obviously in 0.2 Gy and 2 Gy groups. Compared with simple high radiation 2 Gy group, the percentage of P-gp positive cells was decreased significantly (P<0.05). Conclusions:Low radiation dose can reverse multidrug resistance of colorectal cancer cells caused by high radiation dose.

  5. ERp29 is a radiation-responsive gene in IEC-6 cell.

    Science.gov (United States)

    Zhang, Bo; Wang, Meng; Yang, Yuan; Wang, Yan; Pang, Xueli; Su, Yongping; Wang, Junping; Ai, Guoping; Zou, Zhongmin

    2008-11-01

    ERp29 is a resident protein of the endoplasmic reticulum (ER) lumen, which is thought to be involved in the folding of secretory proteins. In our previous work, it was found that, when treated with ionizing radiation (IR), the ERp29 expression was increased in mouse intestinal epithelia and cultured IEC-6 cells, which suggested that ERp29 might be a radiation-induced gene. The current work is to confirm the induction of ERp29 by IR and to analyze its role in irradiated IEC-6 cells. Our results showed that ERp29 expression was elevated by IR in IEC-6 cells at mRNA and protein levels in a time-dependent manner. IEC-6 cells with different exogenous ERp29 expression were obtained by transfection with sense and antisense expression vectors of ERp29 coding region. As ERp29 expression was inhibited, these cells exhibited more serious radiation injury and more sensitivity to IR-induced apoptosis. To further elucidate the induction of ERp29, we analyzed the XBP1 expression after IR. Results showed that the spliced form of XBP1 mRNA rapidly reached a peak at 3 hours after irradiation, which indicated that UPR sensor was involved in radiation and might be a reason to induce ERp29 expression. Our results demonstrate that ERp29 is a radiation associated protein and plays an important role in protecting cells from IR.

  6. Moon's Radiation Environment and Expected Performance of Solar Cells during Future Lunar Missions

    CERN Document Server

    Girish, T E

    2010-01-01

    Several lunar missions are planned ahead and there is an increasing demand for efficient photovoltaic power generation in the moon. The knowledge of solar cell operation in the lunar surface obtained during early seventies need to be updated considering current views on solar variability and emerging space solar cell technologies. In this paper some aspects of the solar cell performance expected under variable lunar radiation environment during future space missions to moon are addressed. We have calculated relative power expected from different types of solar cells under extreme solar proton irradiation conditions and high lunar daytime temperature. It is also estimated that 2-3 % of annual solar cell degradation is most probable during the future lunar missions. We have also discussed photovoltaic power generation in long term lunar bases emphasizing technological needs such as sunlight concentration, solar cell cooling and magnetic shielding of radiation for improving the efficiency of solar cells in the l...

  7. Rapamycin-mediated mTOR inhibition attenuates survivin and sensitizes glioblastoma cells to radiation therapy

    Institute of Scientific and Technical Information of China (English)

    Arunkumar Anandharaj; Senthilkumar Cinghu; Woo-Yoon Park

    2011-01-01

    Survivin, an antiapoptotic protein, is elevated in most malignancies and attributes to radiation resistance in tumors including glioblastoma multiforme. The downregulation of survivin could sensitize glioblastoma ceils to radiation therapy. In this study, we investigated the effect of rapamycin, an inhibitor of mammalian target of rapamycin (mTOR), in attenuating survivin and enhancing the therapeutic efficacy for glioblastoma cells, and elucidated the underlying mechanisms. Here we tested various concentrations of rapamycin (1-8 nM) in combination with radiation dose 4 Gy. Rapamycin effectively modulated the protein kinase B (Akt)/mTOR pathway by inhibiting the phosphorylation of Akt and mTOR proteins, and this inhibition was further enhanced by radiation. The expression level of survivin was decreased in rapamycin pre-treatment glioblastoma ceils followed by radiation; meanwhile, the phosphorylation of H2A histone family member X (H2AX) at serine-139 (γ-H2AX) was increased, p21 protein was also induce on radiation with rapamycin pre-treatment, which enhanced G1 arrest and the accumulation of cells at G0/subG1 phase. Furthermore, the clonogenic cell survival assay revealed a significant dose-dependent decrease in the surviving fraction for all three cell lines pre-treated with rapamycin. Our studies demonstrated that targeting survivin may be an effective approach for radiosensitization of malignant glioblastoma.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-02-15

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

  9. Heat-transfer-method-based cell culture quality assay through cell detection by surface imprinted polymers.

    Science.gov (United States)

    Eersels, Kasper; van Grinsven, Bart; Khorshid, Mehran; Somers, Veerle; Püttmann, Christiane; Stein, Christoph; Barth, Stefan; Diliën, Hanne; Bos, Gerard M J; Germeraad, Wilfred T V; Cleij, Thomas J; Thoelen, Ronald; De Ceuninck, Ward; Wagner, Patrick

    2015-02-17

    Previous work has indicated that surface imprinted polymers (SIPs) allow for highly specific cell detection through macromolecular cell imprints. The combination of SIPs with a heat-transfer-based read-out technique has led to the development of a selective, label-free, low-cost, and user-friendly cell detection assay. In this study, the breast cancer cell line ZR-75-1 is used to assess the potential of the platform for monitoring the quality of a cell culture in time. For this purpose, we show that the proposed methodology is able to discriminate between the original cell line (adherent growth, ZR-75-1a) and a descendant cell line (suspension growth, ZR-75-1s). Moreover, ZR-75-1a cells were cultured for a prolonged period of time and analyzed using the heat-transfer method (HTM) at regular time intervals. The results of these experiments demonstrate that the thermal resistance (Rth) signal decays after a certain number of cell culture passages. This can likely be attributed to a compromised quality of the cell culture due to cross-contamination with the ZR-75-1s cell line, a finding that was confirmed by classical STR DNA profiling. The cells do not express the same functional groups on their membrane, resulting in a weaker bond between cell and imprint, enabling cell removal by mechanical friction, provided by flushing the measuring chamber with buffer solution. These findings were further confirmed by HTM and illustrate that the biomimetic sensor platform can be used as an assay for monitoring the quality of cell cultures in time.

  10. Influence of radiation on the properties of solar cells

    OpenAIRE

    Zdravković Miloš R.; Vasić Aleksandra I.; Radosavljević Radovan Lj.; Vujisić Miloš Lj.; Osmokrović Predrag V.

    2011-01-01

    The wide substitution of conventional types of energy by solar energy lies in the rate of developing solar cell technology. Silicon is still the mostly used element for solar cell production, so efforts are directed to the improvement of physical properties of silicon structures. There are several trends in the development of solar cells, but mainly two directions are indicated: the improvement of the conventional solar cell characteristics based on semiconductor materials, and explorin...

  11. Genetic effects in somatic and germ cells, induced by ionizing radiations

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, B.; Benova, D.; Bajrakova, A.; Bulanova, M.; Vyglenov, A.; Rupova, I.; Georgieva, I. (Meditsinska Akademiya, Sofia (Bulgaria). Nauchen Inst. po Rentgenologiya i Radiobiologiya)

    1983-01-01

    Quantitative data are reported on injuries to hereditary structures in somatic and sex cells, induced by different types of ionizing radiation. The model systems used were human peripheral blood lymphocytes, in vitro irradiated with different doses: bone-marrow cells of mice and rats irradiated in vivo: mouse, rat, rabbit and hamster sex cells. To evaluate the dose-effect dependency after acute and chronic irradiation, the authors used mathematical models, describing the amount of chromosomal injuries. Attempt was made to estimate the somatic and genetic risk, following acute and chronic irradiation with different doses of ionizing radiations.

  12. Typical Cell Signaling Response to Ionizing Radiation:DNA Damage and Extranuclear Damage

    Institute of Scientific and Technical Information of China (English)

    Hui Yu

    2012-01-01

    To treat many types of cancer,ionizing radiation (IR) is primarily used as external-beam radiotherapy,brachytherapy,and targeted radionuclide therapy.Exposure of tumor cells to IR can induce DNA damage as well as generation of reactiveoxygen species (ROS) and reactive nitrogen species (RNS) which can cause non-DNA lesions or extracellular damage like lipid perioxidation.The initial radiation-induced cell responses to DNA damage and ROS like the proteolytic processing,as well as synthesis and releasing ligands (such as growth factors,cytokines,and hormone) can cause the delayed secondary responses in irradiated and unirradiated bystander cells through paracrine and autocrine pathways.

  13. 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

  14. The report of Task Group 100 of the AAPM: Application of risk analysis methods to radiation therapy quality management.

    Science.gov (United States)

    Huq, M Saiful; Fraass, Benedick A; Dunscombe, Peter B; Gibbons, John P; Ibbott, Geoffrey S; Mundt, Arno J; Mutic, Sasa; Palta, Jatinder R; Rath, Frank; Thomadsen, Bruce R; Williamson, Jeffrey F; Yorke, Ellen D

    2016-07-01

    The increasing complexity of modern radiation therapy planning and delivery challenges traditional prescriptive quality management (QM) methods, such as many of those included in guidelines published by organizations such as the AAPM, ASTRO, ACR, ESTRO, and IAEA. These prescriptive guidelines have traditionally focused on monitoring all aspects of the functional performance of radiotherapy (RT) equipment by comparing parameters against tolerances set at strict but achievable values. Many errors that occur in radiation oncology are not due to failures in devices and software; rather they are failures in workflow and process. A systematic understanding of the likelihood and clinical impact of possible failures throughout a course of radiotherapy is needed to direct limit QM resources efficiently to produce maximum safety and quality of patient care. Task Group 100 of the AAPM has taken a broad view of these issues and has developed a framework for designing QM activities, based on estimates of the probability of identified failures and their clinical outcome through the RT planning and delivery process. The Task Group has chosen a specific radiotherapy process required for "intensity modulated radiation therapy (IMRT)" as a case study. The goal of this work is to apply modern risk-based analysis techniques to this complex RT process in order to demonstrate to the RT community that such techniques may help identify more effective and efficient ways to enhance the safety and quality of our treatment processes. The task group generated by consensus an example quality management program strategy for the IMRT process performed at the institution of one of the authors. This report describes the methodology and nomenclature developed, presents the process maps, FMEAs, fault trees, and QM programs developed, and makes suggestions on how this information could be used in the clinic. The development and implementation of risk-assessment techniques will make radiation therapy

  15. Arachidonic metabolism and radiation toxicity in cultures of vascular endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Eldor, A.; Vlodavsky, I.; Fuks, Z.; Matzner, Y.; Rubin, D.B. (Hadassah Univ. Hospital, Jerusalem (Israel) Rush-Presbyterian-St. Luke' s Medical Center, Chicago, IL (USA))

    1989-06-01

    The authors conclude that the observed changes in eicosanoid production by vascular endothelial cells exposed to ionizing irradiation may be relevant to the pathogenesis of post-radiation injury in small and large blood vessels. Anomalies of PGI{sub 2} production may lead to thrombosis and accelerated arteriosclerosis which are observed in irradiated vessels. The generation of potent cells may greatly facilitate inflammation in irradiated vessels. The model of irradiated cultured endothelial cells may also be useful for the study of various methods and agents aimed at reducing the radiation induced damage to blood vessels. Evaluation of the capacity of cultured endothelial cells to produce eicosanoids may serve as an appropriate index for the metabolic damage induced by radiation. (author).

  16. Transformation of human mesenchymal stem cells in radiation carcinogenesis: long-term effect of ionizing radiation

    DEFF Research Database (Denmark)

    Christensen, Rikke; Alsner, Jan; Sørensen, Flemming Brandt;

    2008-01-01

    . A subclone of the cells irradiated with 2.5 Gy of gamma-rays formed tumors after implantation to severe combined immunodeficiency mice. During the process of transformation, the cells showed accelerated telomere shortening, increased levels of anaphase bridges and a shift from balanced to unbalanced...

  17. Image Quality and Radiation Exposure in Coronary CT Angiography According to Tube Voltage and Body Mass Index

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoon Kyung [Korea University Guro Hospital, Seoul (Korea, Republic of); Kim, Yoo Kyung [Ewha Womans University MokDong Hospital, Seoul (Korea, Republic of)

    2010-01-15

    To investigate the image quality and radiation dose of a coronary CT angiography (CCTA) according to tube voltage and body mass index (BMI). This study included 139 patients who underwent CCTA using a retrospective electrocardiography- gating technique. A total of 48 patients (BMI <2 5, group A) were examined with 100 kVp, 45 patients (BMI > 25, group B) with 120 kVp, and 46 patients (BMI < 25, group C) with 120 kVp. Attenuation and image noise of the aorta and coronary arteries was measured. Moreover, the image quality of 9 coronary segments was graded on a scale of 1-5, where grade 4 or 5 was considered to be diagnostic. Image quality parameters and radiation dose were compared using a t-test or Chi-squared test. Results: Vessel attenuation in group A was significantly higher than in groups B or C (group A, 592 {+-} 85 HU; group B, 437 {+-} 46 HU; group C, 469 {+-} 62 HU, p<0.001). Image noise was similar in group A and group B (23 {+-} 5 HU versus 22 {+-} 6 HU, p=0.427), but significantly higher in group A compared to group C (23 {+-} 5 HU versus 17 {+-} 4 HU, p<0.001). A significant difference was observed in the signal-to-noise ratio between the three groups (group A, 24 {+-} 6; group B, 19 {+-} 3; group C, 27 {+-} 5: p<0.05). Moreover, the contrast-to-noise ratio was significantly higher in group A than group B (group A 18 {+-} 5 versus group B 14 {+-} 3, p < 0.001) but not significantly different between group A and group C (group C 20 {+-} 4, p=0.127). The percentage of coronary segments with diagnostic image quality was 97.9% in group A, 96.0% in group B, and 99.0% in group C. The mean image quality score was 4.5 {+-} 0.5 in group A, 4.1 {+-} 0.4 in group B, and 4.2 {+-} 0,4 in group C (p<0.001). The effective radiation doses were 8.5 {+-} 0.8 mSv in group A, 14.3 {+-} 1.3 mSv in group B, and 14.9 {+-} 1.3 mSv in group C. A 42% reduction in mean effective radiation dose in group A was observed compared with groups B and C. In patients with BMI less than 25

  18. Embryo quality predictive models based on cumulus cells gene expression

    Directory of Open Access Journals (Sweden)

    Devjak R

    2016-06-01

    Full Text Available Since the introduction of in vitro fertilization (IVF in clinical practice of infertility treatment, the indicators for high quality embryos were investigated. Cumulus cells (CC have a specific gene expression profile according to the developmental potential of the oocyte they are surrounding, and therefore, specific gene expression could be used as a biomarker. The aim of our study was to combine more than one biomarker to observe improvement in prediction value of embryo development. In this study, 58 CC samples from 17 IVF patients were analyzed. This study was approved by the Republic of Slovenia National Medical Ethics Committee. Gene expression analysis [quantitative real time polymerase chain reaction (qPCR] for five genes, analyzed according to embryo quality level, was performed. Two prediction models were tested for embryo quality prediction: a binary logistic and a decision tree model. As the main outcome, gene expression levels for five genes were taken and the area under the curve (AUC for two prediction models were calculated. Among tested genes, AMHR2 and LIF showed significant expression difference between high quality and low quality embryos. These two genes were used for the construction of two prediction models: the binary logistic model yielded an AUC of 0.72 ± 0.08 and the decision tree model yielded an AUC of 0.73 ± 0.03. Two different prediction models yielded similar predictive power to differentiate high and low quality embryos. In terms of eventual clinical decision making, the decision tree model resulted in easy-to-interpret rules that are highly applicable in clinical practice.

  19. Mitigation of Unwanted Forward Narrow-band Radiation from PCBs with a Metamaterial Unit Cell

    DEFF Research Database (Denmark)

    Ruaro, Andrea; Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2013-01-01

    Mitigation of EMI from a PCB is obtained through the use of a metamaterial unit cell. The focus is on the reduction of narrow-band radiation in the forward hemisphere when the resonant element is etched on a layer located between the source of radiation and the ground plane. As opposed to previous...... publications in the literature, the aim of this work is the application of a filter to scattered radiation, generalizing the former characterizations based solely upon transmission lines’ insertion loss. The radiating area accounts for traces and components placed on the top layer of a PCB and is simulated via...... a patch antenna. The study exhibits how the radiation pattern and the electric field on the patch antenna change within and outside the resonance bandwidth of the parasitic element. An EMC assessment provides experimental verification of the operating principle....

  20. ENHANCEMENT OF RADIATION-INDUCED APOPTOSIS IN RAJI CELL LINE BY BC1-2 ANTISENSE OLIGODEOXYNUCLEOTIDE

    Institute of Scientific and Technical Information of China (English)

    HE Dong-mei; ZHANG Huan

    2005-01-01

    Objective: To investigate whether the Bc1-2 antisense oligonucleotide(ASODN) may enhance radiation-induced apoptosis in Raji cell line. Methods: Cell surviving fraction was determined using the trypan blue dye exclusion assay. The expression level of bc1-2 protein was assayed by immunofluorescence using fluoresce isothiocyanate label. Apoptosis was detected by Giemsa staining and flow cytomertric cell cycle analysis. Results: It was found that Bc1-2 ASODN combined with radiation had significantly reduced the number of viable cells (P<0.05). There was no difference on cell survival between mismatch Bc1-2 oligodeoxynucleotide/radiation combination and radiation-treated cells alone. Bc1-2 ASODN combined with radiation could significantly inhibit expression of Bc1-2 protein in Raji cells (P<0.05). Cells treated with Bc1-2 ASODN combined with radiation at 72 h displayed classic apoptotic changes. Apoptosis rates of Raji cells treated with Bc1-2 oligodeoxynucleotide/radiation combination and radiation-treated cells alone, respectively. Conclusion: Bc1-2 antisense oligonucleotide can enhance radiation-induced apoptosis in Raji cell line.

  1. Why are breast cancer stem cells resistant to radiation?

    Science.gov (United States)

    2013-03-01

    mammosphere formation assay. Xenograft Tumor Formation MDA-MB-231 CSC-like cells or non-stem cells (16104 cells in 0.1 ml of sterile 0.9% NaCl and 0.1 ml of...cells in 0.1 ml of sterile 0.9% NaClFig. 1. Characterization ofMDA-MB-231 andMDA-MB-453 cancer stem cell-like (CSC-like) and under the Oct-3/4 promoter...a nanoscale generation 3 dendrimer in an in vivo colorectal metastatic rat model. Nanomedicine: Nanotechnology , Biology, and Medicine, 7, 249-258

  2. Radiation signature on exposed cells: Relevance in dose estimation

    Institute of Scientific and Technical Information of China (English)

    Venkatachalam; Perumal; Tamizh; Selvan; Gnana; Sekaran; Venkateswarlu; Raavi; Safa; Abdul; Syed; Basheerudeen; Karthik; Kanagaraj; Amith; Roy; Chowdhury; Solomon; FD; Paul

    2015-01-01

    The radiation is considered as a double edged sword, as its beneficial and detrimental effects have been demonstrated. The potential benefits are being exploited to its maximum by adopting safe handling of radionuclide stipulated by the regulatory agencies. While the occupational workers are monitored by personnel monitoring devices, for general publics, it is not a regular practice. However, it can be achieved by using biomarkers with a potential for the radiation triage and medical management. An ideal biomarker to adopt in those situations should be rapid, specific, sensitive, reproducible, and able to categorize the nature of exposure and could provide a reliable dose estimation irrespective of the time of the exposures. Since cytogenetic markers shown to have many advantages relatively than other markers, the origins of various chromosomal abnormalities induced by ionizing radiations along with dose-response curves generated in the laboratory are presented. Current status of the gold standard dicentric chromosome assay, micronucleus assay, translocation measurement by fluorescence insitu hybridization and an emerging protein marker the g-H2 AX assay are discussed with our laboratory data. With the wide choice of methods, an appropriate assay can be employed based on the net.

  3. Radiation signature on exposed cells: Relevance in dose estimation.

    Science.gov (United States)

    Perumal, Venkatachalam; Gnana Sekaran, Tamizh Selvan; Raavi, Venkateswarlu; Basheerudeen, Safa Abdul Syed; Kanagaraj, Karthik; Chowdhury, Amith Roy; Paul, Solomon Fd

    2015-09-28

    The radiation is considered as a double edged sword, as its beneficial and detrimental effects have been demonstrated. The potential benefits are being exploited to its maximum by adopting safe handling of radionuclide stipulated by the regulatory agencies. While the occupational workers are monitored by personnel monitoring devices, for general publics, it is not a regular practice. However, it can be achieved by using biomarkers with a potential for the radiation triage and medical management. An ideal biomarker to adopt in those situations should be rapid, specific, sensitive, reproducible, and able to categorize the nature of exposure and could provide a reliable dose estimation irrespective of the time of the exposures. Since cytogenetic markers shown to have many advantages relatively than other markers, the origins of various chromosomal abnormalities induced by ionizing radiations along with dose-response curves generated in the laboratory are presented. Current status of the gold standard dicentric chromosome assay, micronucleus assay, translocation measurement by fluorescence in-situ hybridization and an emerging protein marker the γ-H2AX assay are discussed with our laboratory data. With the wide choice of methods, an appropriate assay can be employed based on the net.

  4. 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.

  5. Effect of Flavopiridol on Radiation-induced Apoptosis of Human Laryngeal and Lung Cancer Cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Suzy [The Catholic University of Korea College of Medicine, Seoul (Korea, Republic of); Kwon, Eun Kyung; Lee, B. S.; Lee, Seung Hee; Park, B. S.; Wu, Hong Gyun [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2007-12-15

    Purpose: To investigate the flavopiridol effect on radiation-induced apoptosis and expression of apoptosisrelated genes of human laryngeal and lung cancer cells. Materials and Methods: A human laryngeal cancer cell line, AMC-HN3 and a human lung cancer cell line, NCI-H460, were used in the study. The cells were divided into four groups according to the type of treatment: 1) control groups; 2) cells that were only irradiated; 3) cells treated only with flavopiridol; 4) cells treated with flavopiridol and radiation simultaneously. The cells were irradiated with 10 Gy of X-rays using a 4 MV linear accelerator. Flavopiridol was administered to the media at a concentration of 100 nM for 24 hours. We compared the fraction of apoptotic cells of each group 24 hours after the initiation of treatment. The fraction of apoptotic cells was detected by measurement of the sub-G1 fractions from a flow cytometric analysis. The expression of apoptosis-regulating genes, including cleaved caspase-3, cleaved PARP (poly (ADP-ribose) polymerase), p53, p21, cyclin D1, and phosphorylated Akt (protein kinase B) were analyzed by Western blotting. Results: The sub-G1 fraction of cells was significantly increased in the combination treatment group, as compared to cells exposed to radiation alone or flavopiridol alone. Western blotting also showed an increased expression of cleaved caspase-3 and cleaved PARP expression in cells of the combination treatment group, as compared with cells exposed to radiation alone or flavopiridol alone. Treatment with flavopiridol down regulated cyclin D1 expression of both cell lines but its effect on p53 and p21 expression was different according to each individual cell line. Flavopiridol did not affect the expression of phophorylated Akt in both cell lines. Conclusion: Treatment with flavopiridol increased radiation-induced apoptosis of both the human laryngeal and lung cancer cell lines. Flavopiridol effects on p53 and p21 expression were different according

  6. The influence of microwave radiation on the state of chromatin in human cells

    CERN Document Server

    Shckorbatov, Y G; Grabina, V A; Kolchigin, N N; Batrakov, D O; Kalashnikov, V V; Ivanchenko, D D; Bykov, V N

    2008-01-01

    Isolated human buccal epithelium cell were irradiated by microwaves at frequency f=35 GHz and surface power density E=30 mcW/cm2. The state of chromatin in human cells was determined by methodsof light and electron microscopy. The state of cell membranes was evaluated by the method of vital indigo carmine staining. The microwave-induced condensation of chromatin in human cells was revealed. Left side circulary polarized waves induced less effect than linearly polarized radiation. The linearly polarized electromagnetic waves induced cell membrane damage revealed by the increase of cell stainability. The data obtained are discussed in connection with the mechanisms of biologica effect of electromagnetic waves.

  7. Soft x rays as a tool to investigate radiation-sensitive sites in mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Brenner, D.J.; Zaider, M.

    1983-01-01

    It is now clear that the initial geometrical distribution of primary radiation products in irradiated biological matter is fundamental to the observed end point (cell killing, mutation induction, chromosome aberrations, etc.). In recent years much evidence has accumulated indicating that for all radiations, physical quantities averaged over cellular dimensions (micrometers) are not good predictors of biological effect, and that energy-deposition processes at the nanometer level are critical. Thus irradiation of cells with soft x rays whose secondary electrons have ranges of the order of nanometers is a unique tool for investigating different models for predicting the biological effects of radiation. We demonstrate techniques whereby the biological response of the cell and the physical details of the energy deposition processes may be separated or factorized, so that given the response of a cellular system to, say, soft x rays, the response of the cell to any other radiation may be predicted. The special advantages of soft x rays for eliciting this information and also information concerning the geometry of the radiation sensitive structures within the cell are discussed.

  8. Low-dose radiation employed in diagnostic imaging causes genetic effects in cultured cells

    Energy Technology Data Exchange (ETDEWEB)

    Ponzinibbio, Maria V.; Peral-Garcia, Pilar; Seoane, Analia (Inst. de Genetica Veterinaria, Univ. Nacional de La Plata CONICET, La Plata (Argentina)), e-mail: aseoane@fcv.unlp.edu.ar; Crudeli, Cintia (Agencia Nacional de Promocion Cientifica y Tecnologica, La Plata (Argentina))

    2010-11-15

    Background: Exposure to environmental, diagnostic, and occupational sources of radiation frequently involves low doses. Although these doses have no immediately noticeable impact on human health there is great interest in their long-term biological effects. Purpose: To assess immediate and time-delayed DNA damage in two cell lines exposed to low doses of ionizing radiation by using the comet assay and micronucleus test, and to compare these two techniques in the analysis of low-dose induced genotoxicity. Material and Methods: CHO and MRC-5 cells were exposed to 50 milliSievert (mSv) of ionizing radiation and assayed immediately after irradiation and at 16 or 12 passages post-irradiation, respectively. Comet assay and micronucleus test were employed. Results: The comet assay values observed in 50 mSv-treated cells were significantly higher than in the control group for both sample times and cell lines (P < 0.001). Micronuclei frequencies were higher in treated cells than in the control group (P < 0.01, CHO cells passage 16; P < 0.05, MRC-5 cells immediately after exposure; P < 0.01 MRC-5 cells passage 12). Correlation analysis between the two techniques was statistically significant (correlation coefficient 0.82, P < 0.05 and correlation coefficient 0.86, P < 0.05 for CHO and MRC-5 cells, respectively). Cells scored at passages 12 or 16 showed more damage than those scored immediately after exposure in both cell lines (no statistically significant differences). Conclusion: Cytomolecular and cytogenetic damage was observed in cells exposed to very low doses of X-rays and their progeny. A single low dose of ionizing radiation was sufficient to induce such response, indicating that mammalian cells are exquisitely sensitive to it. Comet and micronucleus assays are sensitive enough to assess this damage, although the former seems to be more efficient

  9. The radiation effects on the living cell; Les effets des rayonnements sur la cellule vivante

    Energy Technology Data Exchange (ETDEWEB)

    Sage, E.; Dutrillaux, B.; Soussi, Th. [Institut Curie, 75 - Paris (France)]|[Centre National de la Recherche Scientifique (CNRS), 75 - Paris (France); Boiteux, S.; Lopez, B. [CEA-CNRS/Fontenay-aux-Roses, 92 (France); Feunteun, J. [Institut Gustave Roussy, 94 - Villejuif (France)

    1999-06-01

    This publication is a presentation of particular points discussed during the colloquium of the 15-18 june 1999, for which scientific researches are performed at the CEA/CNRS. They deal with the radiobiology, for the radiation effects on living matter; with the DNA, for the knowledge and repair mechanisms on cells submitted to ionizing radiations; with the exposition to UV in correlation with neoplasms; with the P53 gene which is a tumour suppressor. (A.L.B.)

  10. The combined effect of fludarabine monophosphate and radiation on lymphatic cell lines in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Nitsche, M.; Rave-Fraenk, M.; Wolter, C.; Hess, C.F. [Gottingen Univ. Georg-August, Dept. of Radiation Oncology (Germany); Pradier, O. [Centre Hospitalier Universitaire, Dept. de Cancerologie, 29 - Brest (France)

    2006-11-15

    We could demonstrate a fludarabine-induced radiosensitization in two of four cell lines tested. We conclude, that fludarabine may play a role as radiosensitizer. The combined effect of low dose fludarabine and low dose radiation emphasizes the idea of possible multiple reapplication of radio chemotherapy in progressive lymphoma. Further investigations are warranted to identify the potential of this drug as a radiosensitizer in vivo and to elucidate the mechanism of interaction of the drug and radiation. (N.C.)

  11. On quality control procedures for solar radiation and meteorological measures, from subhourly to montly average time periods

    Science.gov (United States)

    Espinar, B.; Blanc, P.; Wald, L.; Hoyer-Klick, C.; Schroedter-Homscheidt, M.; Wanderer, T.

    2012-04-01

    Meteorological data measured by ground stations are often a key element in the development and validation of methods exploiting satellite images. These data are considered as a reference against which satellite-derived estimates are compared. Long-term radiation and meteorological measurements are available from a large number of measuring stations. However, close examination of the data often reveals a lack of quality, often for extended periods of time. This lack of quality has been the reason, in many cases, of the rejection of large amount of available data. The quality data must be checked before their use in order to guarantee the inputs for the methods used in modelling, monitoring, forecast, etc. To control their quality, data should be submitted to several conditions or tests. After this checking, data that are not flagged by any of the test is released as a plausible data. In this work, it has been performed a bibliographical research of quality control tests for the common meteorological variables (ambient temperature, relative humidity and wind speed) and for the usual solar radiometrical variables (horizontal global and diffuse components of the solar radiation and the beam normal component). The different tests have been grouped according to the variable and the average time period (sub-hourly, hourly, daily and monthly averages). The quality test may be classified as follows: • Range checks: test that verify values are within a specific range. There are two types of range checks, those based on extrema and those based on rare observations. • Step check: test aimed at detecting unrealistic jumps or stagnation in the time series. • Consistency checks: test that verify the relationship between two or more time series. The gathered quality tests are applicable for all latitudes as they have not been optimized regionally nor seasonably with the aim of being generic. They have been applied to ground measurements in several geographic locations, what

  12. Palliative Radiation Therapy for Symptomatic Control of Inoperable Renal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Anatoly Nikolaev

    2016-01-01

    Full Text Available Renal cell carcinoma (RCC is traditionally considered to be resistant to conventional low dose radiation therapy (RT. The emergence of image-guided stereotactic body radiation therapy (SBRT made it possible to deliver much higher doses of radiation. Recent clinical trials of SBRT for RCC showed improvement in local control rates and acceptable toxicity. Here we report a case of inoperable symptomatic RCC that was managed with SBRT. Strikingly, the presenting symptoms of gross hematuria and severe anemia were completely resolved following a course of SBRT. Thus, our case report highlights the potential benefit of this technique for patients with inoperable RCC.

  13. Effect of fractionation and rate of radiation dose on human leukemic cells, HL-60

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, J.G.; Song, C.W.; Kim, T.H.; Levitt, S.H.

    1985-03-01

    The capacity of HL-60 cells, human acute promyelocytic leukemic cells established in culture, to repair sublethal radiation damage was estimated from the response of the cells to fractionated irradiation or to a single irradiation at difference dose rates. After exposure of cells to a single dose of X rays at a dose rate of 78 rad/min, the survival curve was characterized by n = 2.5, D/sub q/ = 80 rad, and D/sub 0/ = 83.2 rad. Split-dose studies demonstrated that the cells were able to repair a substantial portion of sublethal radiation damage in 2 hr. The response of the cells to irradiation at different dose rates decreased with a decrease in the dose rates, which could be attributed to repair of sublethal radiation damage. The possibility that some of the malignant hemopoietic cells, if not all, may possess a substantial capacity to repair sublethal radiation damage should not be underestimated in planning total-body irradiation followed by bone marrow transplantation.

  14. Screen-film versus full-field digital mammography: Radiation dose and image quality in a large teaching hospital

    Directory of Open Access Journals (Sweden)

    Stantić Tomislav J.

    2013-01-01

    Full Text Available The objective of this paper is to measure the radiation dose and image quality in conventional screen-film mammography and full-field digital mammography in women referred to mammography examination. Participants underwent bilateral, two-view screen-film mammography or full-field digital mammography. The visibility of anatomical regions and overall clinical image quality was rated by experienced radiologists. Total of 387 women and 1548 mammograms were enrolled in the study. Image quality was assessed in terms of image quality score, whereas patient dose assessment was performed in terms of mean glandular dose. Average mean glandular dose for cranio-caudal projection was 1.5 mGy and 2.1 mGy in full-field digital mammography and screen-film mammography, respectively. For medio-lateral oblique projection, corresponding values were 2.3 and 2.1 mGy. Overall image quality criteria scoring was 0.82 and 0.99 for screen-film and digital systems, respectively. The scores were in the range from 0.11 to 1.0 for different anatomical structures. Overall, full-field digital mammography was superior both in terms of image quality and dose over the screen-film mammography. The results have indicated that phantom dose values can assist in setting the optimisation activities in mammography and for comparison between mammography units. To obtain accurate diagnostic information with an acceptable radiation dose to breast, it is necessary to periodically perform patient dose and image quality surveys in all mammography units.

  15. The TP53 dependence of radiation-induced chromosome instability in human lymphoblastoid cells

    Science.gov (United States)

    Schwartz, Jeffrey L.; Jordan, Robert; Evans, Helen H.; Lenarczyk, Marek; Liber, Howard

    2003-01-01

    The dose and TP53 dependence for the induction of chromosome instability were examined in cells of three human lymphoblastoid cell lines derived from WIL2 cells: TK6, a TP53-normal cell line, NH32, a TP53-knockout created from TK6, and WTK1, a WIL2-derived cell line that spontaneously developed a TP53 mutation. Cells of each cell line were exposed to (137)Cs gamma rays, and then surviving clones were isolated and expanded in culture for approximately 35 generations before the frequency and characteristics of the instability were analyzed. The presence of dicentric chromosomes, formed by end-to-end fusions, served as a marker of chromosomal instability. Unexposed TK6 cells had low levels of chromosomal instability (0.002 +/- 0.001 dicentrics/cell). Exposure of TK6 cells to doses as low as 5 cGy gamma rays increased chromosome instability levels nearly 10-fold to 0.019 +/- 0.008 dicentrics/cell. There was no further increase in instability levels beyond 5 cGy. In contrast to TK6 cells, unexposed cultures of WTK1 and NH32 cells had much higher levels of chromosome instability of 0.034 +/- 0.007 and 0.041 +/- 0.009, respectively, but showed little if any effect of radiation on levels of chromosome instability. The results suggest that radiation exposure alters the normal TP53-dependent cell cycle checkpoint controls that recognize alterations in telomere structure and activate apoptosis.

  16. Synergistic effect of phenformin in non-small cell lung cancer (NSCLC) ionizing radiation treatment.

    Science.gov (United States)

    Wang, Jia; Xia, Shi'an; Zhu, Zhizhen

    2015-03-01

    Biguanides, used for anti-diabetic drugs, bring more attention in cancer research for their beneficial effects. Phenformin is more potent than metformin. However its potential application as a anti-cancer regent is far behind metformin. In order to investigate any beneficial effect of combination of Phenformin and radiotherapy, non-small cell lung cancer cell lines A549 and H1299 were exposure under different dose of ionizing radiation with or without Phenformin. Results indicated Phenformin showed synergistic effect and could induce more cancer cell apoptosis and inhibition of tumor growth compared with ionizing radiation alone. Furthermore, this synergistic effect may be through different pathway according to cancer cell genotype background. Our results showed Phenformin induced AMPK activation in A549 but not H1299. However, Phenformin activated eIF2α in both cell lines. Our findings implicated Phenformin may be used as radiosensitizer for non-small cell lung cancer therapy.

  17. 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

  18. Radiation effects and radioprotection by Thai medicinal plants in mouse macrophage cell line

    Institute of Scientific and Technical Information of China (English)

    Cheeraratana Cheeramakara; Kriyaporn Songmueng; Wanyarat Nakosiri; Montri Chairojana; Arag Vitittheeranon; Nopchai Suthisai; Nongnuch Jangsawang; Channarong Sanghiran; Apichart Nontprasert

    2009-01-01

    Objective:To investigate the effects of radiation on growth-arrested (GA)and micronucleus-production (MP) rates,and the radioprotective properties of Thai medicinal plants in mouse macrophage cell line RAW264.7 in vitro.Methods:Mouse macrophage cell line (RAW264.7)was cultured in vitro.Various radiation expo-sures,growth-arrested rate assay,micronucleus production assay,and radioprotection by Thai medicinal plants were performed.Results:The results showed that GA and MP rates for γ-rays and UV were dose-dependent. The 50%-affected dose of γand UV radiation for the GA rate was 10 Gy and 159 microwatt/cm2 for 0.5 sec-onds,respectively.After X-ray exposure,there was no apparent effect on RAW264.7 cells,even with a forty-fold human diagnostic dose.Two exposures to γradiation at 20 Gy resulted in a significantly higher MP rate than 20 Gy single exposure or control (P <0.05).The Thai medicinal plants (Kamin-chun capsules,Curcu-ma longa Linn;Hed lingeu,Ganoderma lucidum;Ya Pakking capsule,Murdannia loriformis)could not pre-vent cell damage,but epigallocatechin gallate and L-cysteine could provide protection from 2 Gy γ-ray expo-sure.Conclusion:γradiation caused chromosomal damage during cell division and UV caused cell death, while X-ray radiation was safe.The radioprotective effects of Thai medicinal plants,Kamin-chun,Hed lingeu, and Ya Pakking,could not prevent cell damage in this study.

  19. Protection against radiation-induced damage of 6-propyl-2-thiouracil (PTU) in thyroid cells.

    Science.gov (United States)

    Perona, Marina; Dagrosa, María A; Pagotto, Romina; Casal, Mariana; Pignataro, Omar P; Pisarev, Mario A; Juvenal, Guillermo J

    2013-03-01

    Many epidemiologic studies have shown that the exposure to high external radiation doses increases thyroid neoplastic frequency, especially when given during childhood or adolescence. The use of radioprotective drugs may decrease the damage caused by radiation therapy and therefore could be useful to prevent the development of thyroid tumors. The aim of this study was to investigate the possible application of 6-propyl-2-thiouracil (PTU) as a radioprotector in the thyroid gland. Rat thyroid epithelial cells (FRTL-5) were exposed to different doses of γ irradiation with or without the addition of PTU, methimazole (MMI), reduced glutathione (GSH) and perchlorate (KClO4). Radiation response was analyzed by clonogenic survival assay. Cyclic AMP (cAMP) levels were measured by radioimmunoassay (RIA). Apoptosis was quantified by nuclear cell morphology and caspase 3 activity assays. Intracellular reactive oxygen species (ROS) levels were measured using the fluorescent dye 2',7'-dichlorofluorescein-diacetate. Catalase, superoxide dismutase and glutathione peroxidase activities were also determined. Pretreatment with PTU, MMI and GSH prior to irradiation significantly increased the surviving cell fraction (SF) at 2 Gy (P PTU treated cells in a dose and time-dependent manner. Cells incubated with agents that stimulate cAMP (forskolin and dibutyril cAMP) mimicked the effect of PTU on SF. Moreover, pretreatment with the inhibitor of protein kinase A, H-89, abolished the radioprotective effect of PTU. PTU treatment diminished radiation-induced apoptosis and protected cells against radiation-induced ROS elevation and suppression of the antioxidant enzyme's activity. PTU was found to radioprotect normal thyroid cells through cAMP elevation and reduction in both apoptosis and radiation-induced oxidative stress damage.

  20. The essential role of the Deinococcus radiodurans ssb gene in cell survival and radiation tolerance.

    Directory of Open Access Journals (Sweden)

    J Scott Lockhart

    Full Text Available Recent evidence has implicated single-stranded DNA-binding protein (SSB expression level as an important factor in microbial radiation resistance. The genome of the extremely radiation resistant bacterium Deinococcus radiodurans contains genes for two SSB homologs: the homodimeric, canonical Ssb, encoded by the gene ssb, and a novel pentameric protein encoded by the gene ddrB. ddrB is highly induced upon exposure to radiation, and deletions result in decreased radiation-resistance, suggesting an integral role of the protein in the extreme resistance exhibited by this organism. Although expression of ssb is also induced after irradiation, Ssb is thought to be involved primarily in replication. In this study, we demonstrate that Ssb in D. radiodurans is essential for cell survival. The lethality of an ssb deletion cannot be complemented by providing ddrB in trans. In addition, the radiation-sensitive phenotype conferred by a ddrB deletion is not alleviated by providing ssb in trans. By altering expression of the ssb gene, we also show that lower levels of transcription are required for optimal growth than are necessary for high radiation resistance. When expression is reduced to that of E. coli, ionizing radiation resistance is similarly reduced. UV resistance is also decreased under low ssb transcript levels where growth is unimpaired. These results indicate that the expression of ssb is a key component of both normal cellular metabolism as well as pathways responsible for the high radiation tolerance of D. radiodurans.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

    Monte Carlo calculations have shown that ionising radiations produce a specific type of clustered cell damage called locally multiply damaged sites or LMDS. These lesions consist of closely positioned single-strand breaks, (oxidative) base damage and DNA double-strand breaks (DSB) in between one helical turn of DNA. As specific markers of radiation-induced damage these lesions are likely to condition biological responses and are thus of great interest for radiation protection. Calculations indicate that there should be more LMDS induced by high than by low LET radiation, and they should be absent in un-irradiated cells. Processes like K-shell activation and local Auger electron emission can be expected to add complex DSB or LMDS, producing significant chromosomal damage. In the discussion of the specificity of ionising radiation in comparison to other genotoxic agents, many arguments have been put forward that these lesions should be particularly deleterious for living cells. Complex lesions of that type should represent big obstacles for DNA repair and give rise to high lethality. Moreover, cellular attempts to repair them could accentuate harm, leading to mutations, genetic instability and cancer. In vitro experiments with oligonucleotides containing an artificially introduced set of base damage and SSB in different combinations have shown that depending on the close positioning of the damage on DNA, repair enzymes, and even whole cell extracts, are unable to repair properly and may stimulate mis-repair. Pulsed field gel electrophoresis (PFGE) in conjunction with enzymatic treatments has been used to detect LMDS in mammalian cells after high and low LET radiation. In order to further define the importance of LMDS for radiation induced cellular responses, we studied the induction of LMDS as a function of radiation dose and dose rate in mammalian cells (CHO and MRC5) using {sup 137}Cs gamma-radiation. Using PFGE and specific glycosylases to convert oxidative damage

  2. Effects of Ionizing Radiation and Glutathione Precursor on Antioxidant Enzyme and Cell Survival in Yeast

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jinkyu; Roh, Changhyun; Ryu, Taeho; Park, Jiyoung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Nili, Michael A. [Oxiage Cosmeceutical Research Institute, Virginia (United States)

    2013-05-15

    Cells react to such an induced oxidative stress through scavenging the generated reactive oxygen species to reduce oxidative damage. Antioxidant enzymes such as glutathione peroxidase, catalase, and superoxide dismutase are immediately triggered for reactive oxygen species. N-acetyl-L-cysteine (NAC), a precursor of glutathione, is one of the antioxidants. The effect of NAC as an antioxidant and/or a cell rescue agent was investigated in the present study. Glutathione (GSH) is the most abundant intracellular thiol, which involves in antioxidant defense via direct interaction with ROS or via activities of detoxication enzymes like glutathione peroxidases (GPx). NAC flowed in the cell is converted to cysteine by deacetylation, that is supplied to the depleted GSH by oxidative stress. NAC prevents the depletion of GSH by radiation, increases the production of GSH, and improves enzymes activity such as GPx and alkaline phosphatase. Cell growth and survivorship and transcriptional level of glutathione gene are analyzed in two yeast strains exposed to combined treatment of NAC with gamma-rays. The effect of NAC on cell growth was measured during 72 hours. The cell growth was hampered by higher concentrations of NAC at stationary phase. NAC, however, didn't affect the cell division at the exponential phase. The survival of the cells decreased with radiation dose. The cell viability of the strain W303-1A was reduced significantly at the low dose (10 and 30 Gy). By comparison, the strain W303-1A was more sensitive to radiation with having a half lethal dose (LD{sub 50}) of about 20 Gy. The quantitative RT-PCR analysis showed that the transcriptional expression of antioxidant enzyme gene GPX1 increased after irradiation while the expression of the gene decreased by the combined treatment of NAC with 100 Gy radiation. The present study shows that NAC can directly scavenge ROS against oxidative stress in vivo. In conclusion, NAC can prevent radiation-induced oxidative

  3. Radiation dose and image quality in pediatric chest CT: effects of iterative reconstruction in normal weight and overweight children

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Haesung; Kim, Myung-Joon; Shin, Hyun Joo; Kim, Hyun Gi; Lee, Mi-Jung [Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, Severance Children' s Hospital, Seoul (Korea, Republic of); Yoon, Choon-Sik [Yonsei University College of Medicine, Department of Radiology, Gangnam Severance Hospital, Seoul (Korea, Republic of); Choi, Jiin [Yonsei University College of Medicine, Biostatistics Collaboration Unit, Seoul (Korea, Republic of)

    2015-03-01

    New CT reconstruction techniques may help reduce the burden of ionizing radiation. To quantify radiation dose reduction when performing pediatric chest CT using a low-dose protocol and 50% adaptive statistical iterative reconstruction (ASIR) compared with age/gender-matched chest CT using a conventional dose protocol and reconstructed with filtered back projection (control group) and to determine its effect on image quality in normal weight and overweight children. We retrospectively reviewed 40 pediatric chest CT (M:F = 21:19; range: 0.1-17 years) in both groups. Radiation dose was compared between the two groups using paired Student's t-test. Image quality including noise, sharpness, artifacts and diagnostic acceptability was subjectively assessed by three pediatric radiologists using a four-point scale (superior, average, suboptimal, unacceptable). Eight children in the ASIR group and seven in the control group were overweight. All radiation dose parameters were significantly lower in the ASIR group (P < 0.01) with a greater than 57% dose reduction in overweight children. Image noise was higher in the ASIR group in both normal weight and overweight children. Only one scan in the ASIR group (1/40, 2.5%) was rated as diagnostically suboptimal and there was no unacceptable study. In both normal weight and overweight children, the ASIR technique is associated with a greater than 57% mean dose reduction, without significantly impacting diagnostic image quality in pediatric chest CT examinations. However, CT scans in overweight children may have a greater noise level, even when using the ASIR technique. (orig.)

  4. Cell Recovery after Combined Action of Ionizing Radiation and Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Kyu; Roh, Chang Hyun; Ryu, Tae Ho [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Komarova, Ludmila N.; Petin, Vladislav G. [Medical Radiological Research Center, Obninsk (Russian Federation)

    2012-05-15

    Damage repair in malignant cells would be problematic in sterilization of microorganisms and treatment of cancer, as well. The inhibition of cell recovery and DNA single and double strand breaks repair by chemicals is expressed both as a deceleration of recovery rate and a lesser extent of recovery. Three possibilities are involved in the inhibition of cell recovery: (1) impairment of the recovery process itself, (2) increased irreversible damage, and (3) simultaneous exert of the two. There have been fee publications regarding these problems. The aim of this study was to determine which of these points are involved in the inhibition of cell recovery. In this study, a quantitative approach describing cell recovery from potentially lethal damage as a decrease in the effective dose was used

  5. Kelussia odoratissima potentiates cytotoxic effects of radiation in HeLa cancer cell line

    Directory of Open Access Journals (Sweden)

    Azar Hosseini

    2017-02-01

    Full Text Available Objective: Cervical cancer is the second most common cause of death from cancer in women throughout the world. The aim of this study was to evaluate the cytotoxic activity of Kelussia odoratissima (K. odoratissima extract associated with radiotherapy in cervical cancer cells (HeLa cell line.Materials and Methods: Different concentration of the extract (25-500µg/ml was tested in HeLa cell lines. Cell cytotoxicity of the extract and the effects of the extract on radiation (2Gy/min-induced damages were assessed by MTT assay. Apoptosis was assessed using flow cytometric analysis.Result: K. odoratissima decreased cell viability in HeLa cell line in a concentration and time-dependent manner. When compared to the control,K. odoratissima induced a sub-G1 peak in the flow cytometry histogram of treated cells, indicating that apoptotic cell death is involved in K. odoratissima-induced toxicity. It was also shown that K. odoratissima sensitizes cells to radiation-induced toxicity.Conclusion: Our result showed the extract increased the radiation effect. This observation may be related to the presence of active compounds such as phthalides and ferulic acid.

  6. Dose protraction studies with low- and high-LET radiations on neoplastic cell transformation in vitro

    Science.gov (United States)

    Yang, Tracy Chui-Hsu; Craise, Laurie M.; Tobias, Cornelius A.; Mei, Man-Tong

    1986-01-01

    The effects of the low- and high-LET radiation (by X-rays, Co-60, and heavy ions) on the transformation of neoplastic cells were studied using cultured C3H10T1/2 mouse embryo cells. The transformed colonies in the confluent cell monolayers were recognized as focuses composed of highly polar fibroblastic multilayered criss-cross arrays of densely stained cells. For the low-LET radiation, there was a decrease in cell killing and cell transformation frequency when cells were irradiated with fractionated doses and at a low dose rate, indicating that cultured mammalian cells can repair both subtransformation and potential transformation lesions. No sparing effect, however, was found for the high-LET radiation. An enhancement of cell transformation was observed for low-dose/rate argon (400 MeV/u; 120 keV/micron) and iron particles (600 MeV/u; 200 keV/micron). The molecular mechanism for this enhancement effect is not known.

  7. Effects of non-thermal mobile phone radiation on breast adenocarcinoma cells

    Directory of Open Access Journals (Sweden)

    Zen Fourie

    2011-09-01

    Full Text Available Mobile phone usage currently exceeds landline communication in Africa. The extent of this usage has raised concerns about the long-term health effects of the ongoing use of mobile phones. To assess the physiological effects of radiation from mobile phones in vitro, MCF-7 breast adenocarcinoma cells were exposed to 2W/kg non-thermal 900-MHz mobile phone radiation. The effects investigated were those on metabolic activity, cell morphology, cell cycle progression, phosphatidylserine (PS externalisation and the generation of reactive oxygen species and nitrogen species. Statistically insignificant increases in mitochondrial dehydrogenase activity were observed in irradiated cells when compared to controls. Fluorescent detection of F-actin demonstrated an increase in F-actin stress fibre formation in irradiated MCF-7 cells. Cell cycle progression revealed no statistically significant variation. A small increase in early and late apoptotic events in irradiated MCF-7 cells was observed. No statistically significant changes were observed in reactive oxygen and reactive nitrogen species generation. In addition, quantitative and qualitative analyses of cell cycle activity and nuclear and cytosolic changes, respectively, revealed no significant changes. In conclusion, exposure to 1 h of 900-MHz irradiation induced an increase in PS externalisation and an increase in the formation of F-actin stress fibres in MCF-7 cells. Data obtained from this study, and their correlation with other studies, provides intriguing links between radio frequency radiation and cellular events and warrant further investigation.

  8. 900 MHz radiation does not induce micronucleus formation in different cell types.

    Science.gov (United States)

    Hintzsche, Henning; Jastrow, Christian; Kleine-Ostmann, Thomas; Schrader, Thorsten; Stopper, Helga

    2012-07-01

    The exposure of the population to non-ionising electromagnetic radiation is still increasing, mainly due to mobile communication. Whether low-intensity electromagnetic fields can cause other effects apart from heating has been a subject of debate. One of the effects, which were proposed to be caused by mobile phone radiation, is the occurrence of mitotic disturbances. The aim of this study was to investigate possible consequences of these mitotic disturbances as manifest genomic damage, i.e. micronucleus induction. Cells were irradiated at a frequency of 900 MHz, which is located in one of the main frequency bands applied for mobile communication. Two cell types were used, HaCaT cells as human cells and A(L) cells (human-hamster hybrid cells), in which mitotic disturbances had been reported to occur. After different post-exposure incubation periods, cells were fixed and micronucleus frequencies were evaluated. Both cell types did not show any genomic damage after exposure. To adapt the protocol for the micronucleus test into the direction of the protocol for mitotic disturbances, the post-exposure incubation period was reduced and exposure time was extended to one cell cycle length. This did not result in any increase of the genomic damage. In conclusion, micronucleus induction was not observed as a consequence of exposure to non-ionising radiation, even though this agent was reported to cause mitotic disturbances under similar experimental conditions.

  9. Kelussia odoratissima potentiates cytotoxic effects of radiation in HeLa cancer cell line

    Science.gov (United States)

    Hosseini, Azar; Saeidi Javadi, Shima; Fani-Pakdel, Azar; Mousavi, Seyed Hadi

    2017-01-01

    Objective: Cervical cancer is the second most common cause of death from cancer in women throughout the world. The aim of this study was to evaluate the cytotoxic activity of Kelussia odoratissima (K. odoratissima) extract associated with radiotherapy in cervical cancer cells (HeLa cell line). Materials and Methods: Different concentration of the extract (25-500µg/ml) was tested in HeLa cell lines. Cell cytotoxicity of the extract and the effects of the extract on radiation (2Gy/min)-induced damages were assessed by MTT assay. Apoptosis was assessed using flow cytometric analysis. Result: K. odoratissima decreased cell viability in HeLa cell line in a concentration and time-dependent manner. When compared to the control, K. odoratissima induced a sub-G1 peak in the flow cytometry histogram of treated cells, indicating that apoptotic cell death is involved in K. odoratissima-induced toxicity. It was also shown that K. odoratissima sensitizes cells to radiation-induced toxicity. Conclusion: Our result showed the extract increased the radiation effect. This observation may be related to the presence of active compounds such as phthalides and ferulic acid.

  10. Radiation-induced cell inactivation as a cause for cancer promotion

    Science.gov (United States)

    Heidenreich, W. F.; Paretzke, H. G.

    In space research, estimates of health risks from high-LET radiation, as well as from mixed fields are needed. Features of several applications of the biologically based two step clonal expansion (TSCE) model on data with high-LET radiation, normally α-particles from radon and from Thorotrast, are reviewed. One conclusion is that radiation might not only influence the initiating event in carcinogenesis, but may also act as a promoter. A possible mechanism which gives a promoting action from cell inactivation is presented for the organs "lung", with a two-dimensional arrangement of the cells at risk, and for "liver" where the sensitive cells are distributed in all three dimensions. Inferences for dose-response curves at low doses and dose rates are drawn. For liver, the number and size of premalignant clones is estimated from the cancer data.

  11. Applications of Synchrotron Radiation Micro Beams in Cell Micro Biology and Medicine

    CERN Document Server

    Ide-Ektessabi, Ari

    2007-01-01

    This book demonstrates the applications of synchrotron radiation in certain aspects of cell microbiology, specifically non-destructive elemental analyses, chemical-state analyses and imaging (distribution) of the elements within a cell. The basics for understanding and applications of synchrotron radiation are also described to make the contents easier to be understood for a wide group of researchers in medical and biological sciences who might not be familiar with the physics of synchrotron radiation. The two main techniques that are discussed in this book are the x-ray fluorescence spectroscopy (XRF) and the x-ray fine structure analysis (XAFS). Application of these techniques in investigations of several important scientific fields, such as neurodegeneration and other diseases related to cell malfunctioning, are demonstrated in this book.

  12. The role of the EPA radiation quality assurance program in the measurement quality assurance accreditation program for radioassay laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Grady, T.M. [Environmental Monitoring Systems Laboratory, Las Vegas, NV (United States)

    1993-12-31

    As the nature and extent of radiological contamination becomes better documented and more public, radioanalytical laboratories are faced with a constantly expanding variety of new and difficult analytical requirements. Concurrent with those requirements is the responsibility to provide customers, regulatory officials, or the public with defensible data produced in an environment of verifiable, controlled quality. To meet that need, a quality assurance accreditation program for radioassay laboratories has been proposed by the American National Standards Institute (ANSI). The standard will provide the organizational framework and functional requirements needed to assure the quality of laboratory outputs. Under the proposed program, the U.S. Environmental Protection Agency`s (EPA`s) Laboratory Intercomparison Program plays a key role as a reference laboratory. The current and proposed roles of the EPA Intercomparison Program are discussed, as are the functional relationships between EPA, the accreditating organization, and the service and monitoring laboratories.

  13. Space experiment "Cellular Responses to Radiation in Space (CellRad)": Hardware and biological system tests.

    Science.gov (United States)

    Hellweg, Christine E; Dilruba, Shahana; Adrian, Astrid; Feles, Sebastian; Schmitz, Claudia; Berger, Thomas; Przybyla, Bartos; Briganti, Luca; Franz, Markus; Segerer, Jürgen; Spitta, Luis F; Henschenmacher, Bernd; Konda, Bikash; Diegeler, Sebastian; Baumstark-Khan, Christa; Panitz, Corinna; Reitz, Günther

    2015-11-01

    One factor contributing to the high uncertainty in radiation risk assessment for long-term space missions is the insufficient knowledge about possible interactions of radiation with other spaceflight environmental factors. Such factors, e.g. microgravity, have to be considered as possibly additive or even synergistic factors in cancerogenesis. Regarding the effects of microgravity on signal transduction, it cannot be excluded that microgravity alters the cellular response to cosmic radiation, which comprises a complex network of signaling pathways. The purpose of the experiment "Cellular Responses to Radiation in Space" (CellRad, formerly CERASP) is to study the effects of combined exposure to microgravity, radiation and general space flight conditions on mammalian cells, in particular Human Embryonic Kidney (HEK) cells that are stably transfected with different plasmids allowing monitoring of proliferation and the Nuclear Factor κB (NF-κB) pathway by means of fluorescent proteins. The cells will be seeded on ground in multiwell plate units (MPUs), transported to the ISS, and irradiated by an artificial radiation source after an adaptation period at 0 × g and 1 × g. After different incubation periods, the cells will be fixed by pumping a formaldehyde solution into the MPUs. Ground control samples will be treated in the same way. For implementation of CellRad in the Biolab on the International Space Station (ISS), tests of the hardware and the biological systems were performed. The sequence of different steps in MPU fabrication (cutting, drilling, cleaning, growth surface coating, and sterilization) was optimized in order to reach full biocompatibility. Different coatings of the foil used as growth surface revealed that coating with 0.1 mg/ml poly-D-lysine supports cell attachment better than collagen type I. The tests of prototype hardware (Science Model) proved its full functionality for automated medium change, irradiation and fixation of cells. Exposure of

  14. Identification of differentially expressed radiation-induced genes in cervix carcinoma cells using suppression subtractive hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jun Sang; Lee, Young Sook; Lee, Jeung Hoon; Lee, Woong Hee; Seo, Eun Young; Cho, Moon June [Chungnam National University, Daejeon (Korea, Republic of)

    2005-03-15

    A number of genes and their products are induced early or late following exposure of cells to ionizing radiation. These radiation-induced genes have various effects of irradiated cells and tissues. Suppression subtractive hybridization (SSH) based on PCR was used to identify the differentially expressed genes by radiation in cervix carcinoma cells. Total RNA and poly (A){sup +} mRNA were isolated from irradiated and non-irradiated HeLa cells. Forward-and reverse-subtracted cDNA libraries were constructed using SSH. Eighty-eight clones of each were used to randomly select differentially expressed genes using reverse Northern blotting (dot blot analysis). Northern blotting was used to verify the screened genes. Of the 176 clones, 10 genes in the forward-subtracted library and 9 genes in the reverse-subtracted library were identified as differentially expressed radiation-induced genes by PCR-select differential screening. Three clones from the forward-subtracted library were confirmed by Northern blotting, and showed increased expression in a dose-dependent manner, including a telomerase catalytic subunit and sodium channel-like protein gene, and an ESTs (expressed sequence tags) gene. We identified differentially expressed radiation-induced genes with low-abundance genes with SSH, but further characterization of theses genes are necessary to clarify the biological functions of them.

  15. On spatial distribution of proton radiation belt from solar cell degradation of Akebono satellite

    Science.gov (United States)

    Miyake, W.; Miyoshi, Y.; Matsuoka, A.

    2013-12-01

    Solar cells on any satellite degrade gradually due to severe space radiation environment. We found a fair correlation between the decrease rate of solar cell output current of Akebono satellite orbiting in the inner magnetosphere and trapped proton flux from AP8 model between 1989 and 1992. After 1993, presumably as a result of long-term degradation, variation of solar cell output seems more susceptible to other causes such as high temperature effect, and simple monthly averaged data show no significant relation between them. One of possible causes for the temperature variation of the solar cells is terrestrial heat radiation with changing orientation of solar cell panels towards the earth and another is solar radiation varied with eccentric earth's orbit around the sun. In order to remove the possible temperature effect, we sort the data expected to be least affected by the terrestrial heat radiation from the orbit conditions, and also analyze difference of the output current for a month from that for the same month in the previous year. The analysis method leads us to successfully track a continuous correlation between the decease rate of solar cell output and energetic trapped proton flux up to 1996. We also discuss the best-fitted spatial distribution of energetic protons from comparison with model calculations.

  16. In vitro cultured cells as probes for space radiation effects on biological systems

    Energy Technology Data Exchange (ETDEWEB)

    Meli, A.; Perrella, G.; Curcio, F.; Ambesi-Impiombato, F.S. [Dipartimento di Patologia e Medicina Sperimentale e Clinica, Universita di Udine, P.le S. Maria della Misericordia, 33100 Udine (Italy)

    1999-12-06

    Near future scenarios of long-term and far-reaching manned space missions, require more extensive knowledge of all possible biological consequences of space radiation, particularly in humans, on both a long-term and a short-term basis. In vitro cultured cells have significantly contributed to the tremendous advancement of biomedical research. It is therefore to be expected that simple biological systems such as cultured cells, will contribute to space biomedical sciences. Space represents a novel environment, to which life has not been previously exposed. Both microgravity and space radiation are the two relevant components of such an environment, but biological adaptive mechanisms and efficient countermeasures can significantly minimize microgravity effects. On the other hand, it is felt that space radiation risks may be more relevant and that defensive strategies can only stem from our deeper knowledge of biological effects and of cellular repair mechanisms. Cultured cells may play a key role in such studies. Particularly, thyroid cells may be relevant because of the exquisite sensitivity of the thyroid gland to radiation. In addition, a clone of differentiated, normal thyroid follicular cells (FRTL5 cells) is available in culture, which is well characterized and particularly fit for space research.

  17. 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.

  18. Mechanisms of Enhanced Cell Killing at Low Doses: Implications for Radiation Risk

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Peter J. Johnston; Dr. George D. Wilson

    2003-10-15

    We have shown that cell lethality actually measured after exposure to low-doses of low-LET radiation, is markedly enhanced relative to the cell lethality previously expected by extrapolation of the high-dose cell-killing response. Net cancer risk is a balance between cell transformation and cell kill and such enhanced lethality may more than compensate for transformation at low radiation doses over a least the first 10 cGy of low-LET exposure. This would lead to a non-linear, threshold, dose-risk relationship. Therefore our data imply the possibility that the adverse effects of small radiation doses (<10 cGy) could be overestimated in specific cases. It is now important to research the mechanisms underlying the phenomenon of low-dose hypersensitivity to cell killing, in order to determine whether this can be generalized to safely allow an increase in radiation exposure limits. This would have major cost-reduction implications for the whole EM program.

  19. Combined effect of heptaplatin and ionizing radiation on human squamous carcinoma cell lines.

    Science.gov (United States)

    Ryu, Mi-Ryeong; Paik, Soon-Young; Chung, Su-Mi

    2005-02-28

    Heptaplatin, cis-malonato [(4R,5R)-4,5-bis (amino-methyl)-2-isopropyl-1,3-dioxolane] platinum(II) (SKI-2053R, Sunpla) is a new platinum derivative with anti-tumor activity comparable to cisplatin on various cancer cell lines. Preclinical studies suggest that it is less nephrotoxic than cisplatin. This study was undertaken to examine the combined effect of heptaplatin and ionizing radiation on two established human squamous carcinoma cell lines (NCI-H520, SQ20B). The cytotoxic activity of heptaplatin was concentration-dependent in both cell lines. When low dose heptaplatin was combined with high dose ionizing radiation, there was an additive cytotoxic effect on NCI-H520 cells (P < 0.05), while a moderate dose of heptaplatin and a low dose of ionizing radiation had an additive cytotoxic effect on the growth of SQ20B cells (P < 0.05). FACS analysis and DAPI staining showed that their additive cytotoxic effects were correlated with the induction of apoptosis. Further studies are warranted using heptaplatin and ionizing radiation in squamous cell carcinoma as a substitute for cisplatin.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-15

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

  1. Cell damage from radiation-induced bystander effects for different cell densities simulated by a mathematical model via cellular automata

    Energy Technology Data Exchange (ETDEWEB)

    Meireles, Sincler P. de; Santos, Adriano M.; Grynberg, Suely Epsztein, E-mail: spm@cdtn.b, E-mail: amsantos@cdtn.b, E-mail: seg@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Nunes, Maria Eugenia S., E-mail: mariaeugenia@iceb.ufop.b [Universidade Federal de Ouro Preto (UFOP), MG (Brazil)

    2011-07-01

    During recent years, there has been a shift from an approach focused entirely on DNA as the main target of ionizing radiation to a vision that considers complex signaling pathways in cells and among cells within tissues. Several newly recognized responses were classified as the so-called non-target responses in which the biological effects are not directly related to the amount of energy deposited in the DNA of cells that were traversed by radiation. In 1992 the bystander effect was described referring to a series of responses such as death, chromosomal instability or other abnormalities that occur in non-irradiated cells that came into contact with irradiated cells or medium from irradiated cells. In this work, we have developed a mathematical model via cellular automata, to quantify cell death induced by the bystander effect. The model is based on experiments with irradiated cells conditioned medium which suggests that irradiated cells secrete molecules in the medium that are capable of damaging other cells. The computational model consists of two-dimensional cellular automata which is able to simulate the transmission of bystander signals via extrinsic route and via Gap junctions. The model has been validated by experimental results in the literature. The time evolution of the effect and the dose-response curves were obtained in good accordance to them. Simulations were conducted for different values of bystander and irradiated cell densities with constant dose. From this work, we have obtained a relationship between cell density and effect. (author)

  2. Metrology and quality of radiation therapy dosimetry of electron, photon and epithermal neutron beams

    Energy Technology Data Exchange (ETDEWEB)

    Kosunen, A

    1999-08-01

    In radiation therapy using electron and photon beams the dosimetry chain consists of several sequential phases starting by the realisation of the dose quantity in the Primary Standard Dosimetry Laboratory and ending to the calculation of the dose to a patient. A similar procedure can be described for the dosimetry of epithermal neutron beams in boron neutron capture therapy (BNCT). To achieve the required accuracy of the dose delivered to a patient the quality of all steps in the dosimetry procedure has to be considered. This work is focused on two items in the dosimetry chains: the determination of the dose in the reference conditions and the evaluation of the accuracy of dose calculation methods. The issues investigated and discussed in detail are: a)the calibration methods of plane parallel ionisation chambers used in electron beam dosimetry, (b) the specification of the critical dosimetric parameter i.e. the ratio of stopping powers for water to air, (S I ?){sup water} {sub air}, in photon beams, (c) the feasibility of the twin ionization chamber technique for dosimetry in epithermal neutron beams applied to BNCT and (d) the determination accuracy of the calculated dose distributions in phantoms in electron, photon, and epithermal neutron beams. The results demonstrate that up to a 3% improvement in the consistency of dose determinations in electron beams is achieved by the calibration of plane parallel ionisation chambers in high energy electron beams instead of calibrations in {sup 60}Co gamma beams. In photon beam dosimetry (S I ?){sup water} {sub air} can be determined with an accuracy of 0.2% using the percentage dose at the 10 cm depth, %dd(10), as a beam specifier. The use of %odd(10) requires the elimination of the electron contamination in the photon beam. By a twin ionisation chamber technique the gamma dose can be determined with uncertainty of 6% (1 standard deviation) and the total neutron dose with an uncertainty of 15 to 20% (1 standard deviation

  3. TU-G-BRD-02: Automated Systematic Quality Assurance Program for Radiation Oncology Information System Upgrades

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, B; Yi, B; Eley, J; Mutaf, Y; Rahman, S; D’Souza, W [University of Maryland School of Medicine, Baltimore, MD (United States)

    2015-06-15

    Purpose: To: (1) describe an independent, automated, systematic software-based protocol for verifying clinical data accuracy/integrity for mitigation of data corruption/loss risks following radiation oncology information system (ROIS) upgrades; and (2) report on application of this approach in an academic/community practice environment. Methods: We propose a robust approach to perform quality assurance on the ROIS after an upgrade, targeting four data sources: (1) ROIS relational database; (2) ROIS DICOM interface; (3) ROIS treatment machine data configuration; and (4) ROIS-generated clinical reports. We investigated the database schema for differences between pre-/post-upgrade states. Paired DICOM data streams for the same object (such as RT-Plan/Treatment Record) were compared between pre-/post-upgrade states for data corruption. We examined machine configuration and related commissioning data files for changes and corruption. ROIS-generated treatment appointment and treatment parameter reports were compared to ensure patient encounter and treatment plan accuracy. This protocol was supplemented by an end-to-end clinical workflow test to verify essential ROI functionality and integrity of components interfaced during patient care chain of activities. We describe the implementation of this protocol during a Varian ARIA system upgrade at our clinic. Results: We verified 1,638 data tables with 2.4 billion data records. For 222 under-treatment patients, 605 DICOM RT plans and 13,480 DICOM treatment records retrieved from the ROIS DICOM interface were compared, with no differences in fractions, doses delivered, or treatment parameters. We identified 82 new data tables and 78 amended/deleted tables consistent with the upgrade. Reports for 5,073 patient encounters over a 2-week horizon were compared and were identical to those before the upgrade. Content in 12,237 xml machine files was compared, with no differences identified. Conclusion: An independent QA

  4. Differential Sensitivity of Cells to Radiation Mediated by p53 Pulses

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Kyu; Kang, Mi Young; Kawala, Remigius A.; Ryu, Tae Ho; Kim, Jin-Hong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Exposure of cells to ionizing radiation activates protein genes related cell cycle arrest and cell death (apoptosis or autophagy). The tumor suppressor p53 participates not only in regulation of apoptosis, but also in autophagy mechanism. Apoptosis (type I cell death) is characterized by the activation of caspases and the formation of apoptotic bodies, and plays essential roles in all multicellular organisms. On the other hand, autophagy (type II cell death) is characterized by the presence of cytoplasmic engulfing vesicles, alias autophagosomes, and is a major intracellular pathway for degradation and recycling of proteins, ribosomes and entire organelles. The purpose of this study was to determine whether ionizing radiation treatment induces autophagy depending on the p53 expression levels. RKO (wild-type p53) and RKO E6 (null-type p53) cells were used to evaluate the effects of p53 on the sensitivity of cells to ionizing radiation. In the RKO E6 cells, the function of p53 was disabled with human papillomavirus E6 oncoprotein. These results indicated that p53 and p21 were required to block apoptosis and induce autophagy in RKO cells. The expression of p21 by a p53-dependent mechanism is required to develop autophagic properties after DNA damage. Results in this study suggest that the radioresistance of the RKO cells was associated with the increased p21 expression, resulting in autophagy induction. The tumor suppressor p53 could regulate radiosensitivity by inhibiting autophagy and activating apoptosis; the ionizing radiation-induced expression of p53 in the RKO cells regulated autophagy, suggesting the significance of the level of p53 in determining the radiosensitivity by regulating autophagy and apoptosis.

  5. REDD1 protects osteoblast cells from gamma radiation-induced premature senescence.

    Directory of Open Access Journals (Sweden)

    Xiang Hong Li

    Full Text Available Radiotherapy is commonly used for cancer treatment. However, it often results in side effects due to radiation damage in normal tissue, such as bone marrow (BM failure. Adult hematopoietic stem and progenitor cells (HSPC reside in BM next to the endosteal bone surface, which is lined primarily by hematopoietic niche osteoblastic cells. Osteoblasts are relatively more radiation-resistant than HSPCs, but the mechanisms are not well understood. In the present study, we demonstrated that the stress response gene REDD1 (regulated in development and DNA damage responses 1 was highly expressed in human osteoblast cell line (hFOB cells after γ irradiation. Knockdown of REDD1 with siRNA resulted in a decrease in hFOB cell numbers, whereas transfection of PCMV6-AC-GFP-REDD1 plasmid DNA into hFOB cells inhibited mammalian target of rapamycin (mTOR and p21 expression and protected these cells from radiation-induced premature senescence (PS. The PS in irradiated hFOB cells were characterized by significant inhibition of clonogenicity, activation of senescence biomarker SA-β-gal, and the senescence-associated cytokine secretory phenotype (SASP after 4 or 8 Gy irradiation. Immunoprecipitation assays demonstrated that the stress response proteins p53 and nuclear factor κ B (NFkB interacted with REDD1 in hFOB cells. Knockdown of NFkB or p53 gene dramatically suppressed REDD1 protein expression in these cells, indicating that REDD1 was regulated by both factors. Our data demonstrated that REDD1 is a protective factor in radiation-induced osteoblast cell premature senescence.

  6. Palmitoylethanolamide regulates development of intestinal radiation injury in a mast cell dependent manner

    Science.gov (United States)

    Wang, Junru; Zheng, Junying; Kulkarni, Ashwini; Wang, Wen; Garg, Sarita; Prather, Paul L.; Hauer-Jensen, Martin

    2014-01-01

    Background Mast cells and neuroimmune interactions regulate the severity of intestinal radiation mucositis, a dose-limiting toxicity during radiation therapy of abdominal malignancies. Aims Because endocannabinoids regulate intestinal inflammation, we investigated the effect of the cannabimimetic, palmitoylethanolamide (PEA), in a mast competent (+/+) and mast cell deficient (Ws/Ws) rat model. Methods Rats underwent localized, fractionated intestinal irradiation and received daily injections with vehicle or PEA from 1 day before until 2 weeks after radiation. Intestinal injury was assessed non-invasively by luminol bioluminescence, and, at 2 weeks, by histology, morphometry, and immunohistochemical analysis, gene expression analysis, and pathway analysis. Results Compared to +/+ rats, Ws/Ws rats sustained more intestinal structural injury (p=0.01), mucosal damage (p=0.02), neutrophil infiltration (p=0.0003), and collagen deposition (p=0.004). PEA reduced structural radiation injury (p=0.02), intestinal wall thickness (p=0.03), collagen deposition (p=0.03), and intestinal inflammation (p=0.02) in Ws/Ws rats, but not in +/+ rats. PEA inhibited mast cell-derived cellular immune response and anti-inflammatory IL-6 and IL-10 signaling, and activated the prothrombin pathway in +/+ rats. In contrast, while PEA suppressed non-mast cell derived immune responses, it increased anti-inflammatory IL-10 and IL-6 signaling and decreased activation of the prothrombin pathway in Ws/Ws rats. Conclusions These data demonstrate that the absence of mast cells exacerbate radiation enteropathy by mechanisms that likely involve the coagulation system, anti-inflammatory cytokine signaling, and the innate immune system; and that these mechanisms are regulated by PEA in a mast cell-dependent manner. The endocannabinoid system should be explored as target for mitigating intestinal radiation injury. PMID:24848354

  7. Delta-tocotrienol suppresses radiation-induced microRNA-30 and protects mice and human CD34+ cells from radiation injury.

    Directory of Open Access Journals (Sweden)

    Xiang Hong Li

    Full Text Available We reported that microRNA-30c (miR-30c plays a key role in radiation-induced human cell damage through an apoptotic pathway. Herein we further evaluated radiation-induced miR-30 expression and mechanisms of delta-tocotrienol (DT3, a radiation countermeasure candidate, for regulating miR-30 in a mouse model and human hematopoietic CD34+ cells. CD2F1 mice were exposed to 0 (control or 7-12.5 Gy total-body gamma-radiation, and CD34+ cells were irradiated with 0, 2 or 4 Gy of radiation. Single doses of DT3 (75 mg/kg, subcutaneous injection for mice or 2 μM for CD34+ cell culture were administrated 24 h before irradiation and animal survival was monitored for 30 days. Mouse bone marrow (BM, jejunum, kidney, liver and serum as well as CD34+ cells were collected at 1, 4, 8, 24, 48 or 72 h after irradiation to determine apoptotic markers, pro-inflammatory cytokines interleukin (IL-1β and IL-6, miR-30, and stress response protein expression. Our results showed that radiation-induced IL-1β release and cell damage are pathological states that lead to an early expression and secretion of miR-30b and miR-30c in mouse tissues and serum and in human CD34+ cells. DT3 suppressed IL-1β and miR-30 expression, protected against radiation-induced apoptosis in mouse and human cells, and increased survival of irradiated mice. Furthermore, an anti-IL-1β antibody downregulated radiation-induced NFκBp65 phosphorylation, inhibited miR-30 expression and protected CD34+ cells from radiation exposure. Knockdown of NFκBp65 by small interfering RNA (siRNA significantly suppressed radiation-induced miR-30 expression in CD34+ cells. Our data suggest that DT3 protects human and mouse cells from radiation damage may through suppression of IL-1β-induced NFκB/miR-30 signaling.

  8. Ionizing radiation - one of the most important link of the energetic chain in biological cell

    Energy Technology Data Exchange (ETDEWEB)

    Goraczko, W. [Technical Univ. Poznan, Radio- and Photochemistry Dept., Poznan (Poland)

    1999-09-01

    High (large) and low (small) doses of ionizing radiation consistently induce opposite physiologic effects in biological systems. The effects of low doses cannot be inferred by interpolation between the result from groups exposed to high doses and controls irradiated only by Natural Background Radiation. Stimulation ('bio-positive') effects by low-level doses of ionizing radiation are called radiation hormesis. It is still controversial idea, however it was found that some biological objects (yeast, seeds, animals) after gamma irradiation by low-level doses (10-50 times more NBR) can increase their development. The result of present researches demonstrate that the excitation of living system by gamma quanta (high energy) initiates prolonged secondary emission that influences biota and activates many important processes in biological systems. According to the excitation theory of bio-molecules the author suggests that gamma irradiation in low-level doses excites such molecules as DNA and proteins, and this being followed by a long-termed secondary coherent radiation. The spectral analysis of this secondary emission confirmed the contribution of the UV component to the total emission. The data obtaining by using SPC method (single photon counting) make possible a partial understanding of the radiation hormesis phenomenon and suggest closer relationship to UV emission from biological systems during mitotic processes. The experiments with humic acid (high doses) and glycine (low doses) confirm the author hypothesis that gamma-irradiated organic compounds are capable to emit secondary radiation. This secondary radiation probably plays very significant role in the intercellular communication inside the living systems. In conclusion the author proposed de-excitation processes in bio-molecules as a common denominator of UV and ionizing radiation interacting with living cells. Finally he refers to the Cerenkov radiation which is created inside the biological cells

  9. Role of tumour initiating cells in the radiation resistance of osteosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Klymenko, Olena

    2014-02-26

    In the present study we confirm that mouse osteosarcoma (MOS) cells lines possess a subset of cells with Tumour Initiating Cells (TICs) properties. We found that isolated TICs are not inherently radioresistant compared to non-TICs. On the other hand, we found that the fraction of TICs correlates well with the radiosensitivity of MOS cell lines measured using clonogenic cell survival assay. We conclude from our study that the TICs contribute to the tumour radiation response due to their interaction with their tumour surrounding environmental (niche).

  10. [Increase in the number of cancer stem cells after exposure to low-LET radiation].

    Science.gov (United States)

    Zamulaeva, I A; Matchuk, O N; Selivanova, E I; Andreev, V G; Lipunov, N M; Makarenko, S A; Zhavoronkov, L P; Saenko, A S

    2014-01-01

    Radioresistance of cancer stem cells (CSCs) is regarded as one of the possible causes of cancer recurrence after radiotherapy. Since the regularities and mechanisms of radiation effects on this population of cells have not been sufficiently studied, the aim of this work is to elucidate the changes in the CSC number after γ-irradiation in stable cultures of tumor cells in vitro and tumor tissue in vivo (in the course of radiation therapy of patients with cancers of the upper respiratory tract). CSCs were identified in the cell lines B16, MCF-7, HeLa by the ability to exclude the fluorescent dye Hoechst 33342 (SP method) 48-72 h after irradiation at the doses of 1-20 Gy and in biopsy material by immunophenotype CD44+CD24(-/low) before and 24 h after irradiation at the total dose of 10 Gy. The essential differences in the response of CSCs and other cancer cells were found after exposure to low-LET radiation. The absolute number of CSCs increased after a single exposure at the doses ranging from 1 to 5-10 Gy in different cell cultures, but a further dose increase maintained the current number of CSCs or decreased it. At the same time, the number of non CSCs significantly decreased with increasing doses of radiation exposure, as expected. Fractionated irradiation in vivo at a total dose of 10 Gy increased the relative amount of CSCs in most patients. The registered changes are an integral indicator of cell death, cell division delay immediately after irradiation, proliferation at a later time, possible dedifferentiation of non CSCs, etc. The exact contribution of each of them to the radiation-induced increase of the CSCs number is of considerable interest and requires further research.

  11. Nimotuzumab enhances radiation sensitivity of NSCLC H292 cells in vitro by blocking epidermal growth factor receptor nuclear translocation and inhibiting radiation-induced DNA damage repair

    Directory of Open Access Journals (Sweden)

    Teng K

    2015-04-01

    Full Text Available Kai Teng,1,2,* Yong Zhang,1,* Xiaoyan Hu,1 Yihui Ding,1 Rui Gong,1 Li Liu1,* 1Department of Thoracic Oncology, Cancer Center of Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People’s Republic of China; 2Department of Radiation Oncology, Hainan Cancer Hospital, Haikou, Hainan, People’s Republic of China *These authors contributed equally to this work Background: The epidermal growth factor receptor (EGFR signaling pathway plays a significant role in radiation resistance. There is evidence that EGFR nuclear translocation is associated with DNA double-strand breaks (DSB repair. Nimotuzumab has shown the effect of radiosensitization in various cancer cells, but little is known about the relationship between nimotuzumab and EGFR nuclear translocation in non-small cell lung cancer (NSCLC cell lines. In this study, we selected two NSCLC cell lines, namely, H292 (with high EGFR expression and H1975 (with low EGFR expression and explored the mechanisms underlying radiation sensitivity.Methods: MTT assay, clonogenic survival assay, and flow cytometry were performed separately to test cell viability, radiation sensitivity, cell cycle distribution, and apoptosis. Protein γ-H2AX, DNA-PK/p-DNA-PK, and EGFR/p-EGFR expression were further compared both in the cytoplasm and the nucleus with the western blot.Results: Nimotuzumab reduced the viability of H292 cells and sensitized H292 cells to ionizing radiation. The radiation sensitivity enhancement ratio (SER was 1.304 and 1.092 for H292 and H1975 cells, respectively. H292 cells after nimotuzumab administration were arrested at the G0/G1 phase in response to radiation. Apoptosis was without statistical significance in both cell lines. γ-H2AX formation in the combination group (nimotuzumab and radiation increased both in the cytoplasm and the nucleus along with the decreased expression of nuclear EGFR/p-EGFR and p-DNA-PK in H292 cells (P<0.05 that

  12. Photosynthetically Available Radiation, Aqua MODIS, NPP, 0.05 degrees, Global, Science Quality

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — MODIS measures photosynthetically available radiation that may be used to mode primary productivity. THIS IS AN EXPERIMENTAL PRODUCT: intended strictly for...

  13. Cancer stem cell overexpression of nicotinamide N-methyltransferase enhances cellular radiation resistance

    DEFF Research Database (Denmark)

    D’Andrea, Filippo P.; Safwat, Akmal; Kassem, Moustapha;

    2011-01-01

    BackgroundCancer stem cells are thought to be a radioresistant population and may be the seeds for recurrence after radiotherapy. Using tumorigenic clones of retroviral immortalized human mesenchymal stem cell with small differences in their phenotype, we investigated possible genetic expression...... that could explain cancer stem cell radiation resistance. MethodsTumorigenic mesenchymal cancer stem cell clones BB3 and CE8 were irradiated at varying doses and assayed for clonogenic surviving fraction. Altered gene expression before and after 2Gy was assessed by Affymetric exon chip analysis and further...... found the genes involved in cancer, proliferation, DNA repair and cell death. ConclusionsThe higher radiation resistance in clone CE8 is likely due to NNMT overexpression. The higher levels of NNMT could affect the cellular damage resistance through depletion of the accessible amounts of nicotinamide...

  14. Radiation enteropathy and leucocyte-endothelial cell reactions in a refined small bowel model

    Directory of Open Access Journals (Sweden)

    Osman Nadia

    2004-09-01

    Full Text Available Abstract Background Leucocyte recruitment and inflammation are key features of high dose radiation-induced tissue injury. The inflammatory response in the gut may be more pronounced following radiotherapy due to its high bacterial load in comparison to the response in other organs. We designed a model to enable us to study the effects of radiation on leucocyte-endothelium interactions and on intestinal microflora in the murine ileum. This model enables us to study specifically the local effects of radiation therapy. Method A midline laparotomy was performed in male C57/Bl6 mice and a five-centimetre segment of ileum is irradiated using the chamber. Leucocyte responses (rolling and adhesion were then analysed in ileal venules 2 – 48 hours after high dose irradiation, made possible by an inverted approach using intravital fluorescence microscopy. Furthermore, intestinal microflora, myeloperoxidase (MPO and cell histology were analysed. Results The highest and most reproducible increase in leucocyte rolling was exhibited 2 hours after high dose irradiation whereas leucocyte adhesion was greatest after 16 hours. Radiation reduced the intestinal microflora count compared to sham animals with a significant decrease in the aerobic count after 2 hours of radiation. Further, the total aerobic counts, Enterobacteriaceae and Lactobacillus decreased significantly after 16 hours. In the radiation groups, the bacterial count showed a progressive increase from 2 to 24 hours after radiation. Conclusion This study presents a refinement of a previous method of examining mechanisms of radiation enteropathy, and a new approach at investigating radiation induced leucocyte responses in the ileal microcirculation. Radiation induced maximum leucocyte rolling at 2 hours and adhesion peaked at 16 hours. It also reduces the microflora count, which then starts to increase steadily afterwards. This model may be instrumental in developing strategies against pathological

  15. Effects of Radiation on Proteasome Function in Prostate Cancer Cells

    Science.gov (United States)

    2009-02-01

    Transcription ribosomal protein L19, L24l L26, L27a, S13, S3a similar to 40S ribosomal protein SA ( p40 ) (34/67 kDa laminin receptor...mM ATP, 0.2% [vol/vol] Nonidet P-40 and 20% glycerol) were added to the cells, and the mixtures were vortexed for 1 minute. Beads and cell debris

  16. High Energy Electron Radiation Degradation of Gallium Arsenide Solar Cells.

    Science.gov (United States)

    1986-03-01

    relative spectral output of the Kratos source was determined. This procedure may be algebraically verified since the cell output current, i, is equal...A (cm2), then a unique voltage may be calculated for given values of 0 and C. Algebraically , this equation may be written as ~q A 77e ____ __ 8) C...position as necessary to achieve proper voltage. (d) Place solar cell on test block using plastic tweezers. (e) Start test program by typing " BASICA

  17. Physiological quality of rice seed submitted to gamma radiation; Qualidade fisiologica de sementes de arroz submetidas a radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Helen Lucia da Cruz; Tillmann, Maria Angela Andre; Meneghello, Geri Eduardo, E-mail: helenllc@gmail.co [Universidade Federal de Pelotas (UFPel), RS (Brazil). Programa de Pos-graduacao em Ciencia e Tecnologia de Sementes; Bobrowski, Vera Lucia [Universidade Federal de Pelotas (UFPel), RS (Brazil). Dept. de Genetica; Dode, Luciana Bicca [Universidade Catolica de Pelotas (UCPel), RS (Brazil)

    2009-08-15

    The objective of this research was to evaluate the effects of the gamma radiation ({sup 60}Co) on the physiological quality of rice seeds. The research was carried out through three tests; in the first test rice seeds were irradiated at dosages of 0; 1; 2.5 and 5Gy, while for the second and third tests the seeds were subjected to accelerated aging before being irradiated. For the second test the seeds were divided into wet and dry and both groups subjected to accelerated aging previous to irradiation at dosages of 0; 1; 2.5 and 5Gy. For the third test the seeds were dried after being subjected to accelerated aging, and then irradiated at dosages of 0, 10, 25 and 50Gy. To assess the physiological effects of the gamma radiation, all seeds were tested for germination and their germination speed index recorded. Seedling growth was graded through the measurement of the lengths of the first leaf and seminal root system and total seedling dry weight, across all tests. The enzymatic activity of acid phosphatase and alpha-amylase was measured on dry seeds from the second test. The results from all tests indicate that the applied gamma radiation dosages did not cause any changes to the physiological quality of rice seeds. (author)

  18. Low-power laser irradiation did not stimulate breast cancer cells following ionizing radiation

    Science.gov (United States)

    Silva, C. R.; Camargo, C. F. M.; Cabral, F. V.; Ribeiro, M. S.

    2016-03-01

    Cancer has become a public health problem worldwide. Radiotherapy may be a treatment to a number of types of cancer, frequently using gamma-radiation with sources such as 137Cs and 60Co, with varying doses, dose rates, and exposure times to obtain a better as a stimulant for cell proliferation and tissue healing process. However, its effects on cancer cells are not yet well elucidated. The purpose of this work was to evaluate the effects of the LPL on breast cancer cultures after ionizing radiation. The breast cancer-MDA-MB-231 cells were gamma irradiated by a 60Co source, with dose of 2.5 Gy. After 24h, cells were submitted to LPL irradiation using a red laser emitting at λ= 660 nm, with output power of 40 mW and exposure time of 30 s and 60 s. The plates were uniformly irradiated, with energy of 1.2 J and 2.4 J, respectively. Cell viability was analyzed using the exclusion method with trypan blue. Our results show that breast cancer cells submitted to LPL after ionizing radiation remained 95 % viable. No statistically significant differences were observed between laser and control untreated cells, (P > 0.05). These findings suggest that LPL did not influenced cancer cells viability.

  19. Cellular and molecular alterations in human epithelial cells transformed by high let radiation

    Science.gov (United States)

    Hei, T. K.; Piao, C. Q.; Sutter, T.; Willey, J. C.; Suzuki, K.

    An understanding of the radiobiological effects of high LET radiation is essential for human risk estimation and radiation protection. In the present study, we show that a single, 30 cGy dose of 150 keV/mum ^4He ions can malignantly transform human papillomavirus immortalized human bronchial epithelial [BEP2D] cells. Transformed cells produce progressively growing tumors in nude mice. The transformation frequency by the single dose of alpha particles is estimated to be approximately 4 x 10^-7. Based on the average cross-sectional area of BEP2D cells, it can be calculated that a mean traversal of 1.4 particles per cell is sufficient to induce tumorigenic conversion of these cells 3 to 4 months post-irradiation. Tumorigenic BEP2D cells overexpress mutated p53 tumor suppressor oncoproteins in addition to the cell cycle control gene cyclin D1 and D2. This model provides an opportunity to study the cellular and molecular changes at the various stages in radiation carcinogenesis involving human cells.

  20. A human esophageal epithelial cell model for study of radiation induced cancer and DNA repair

    Science.gov (United States)

    Huff, Janice; Patel, Zarana; Hada, Megumi; Cucinotta, Francis A.

    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. Development of squamous cell carcinoma of the esophagus is associated with radiation exposure, as revealed by the significant enhanced in incidence rates for this type of cancer in the survivors of the atomic bomb detonations in Japan. It is also associated with poor nutritional status and micronutrient deficiencies, which are also important issues for long duration spaceflight. The possible synergies between nutritional issues and radiation exposure are unknown. Here we present the results of 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 gamma-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.

  1. Reduction of radiation exposure and improvement of image quality with BMI-adapted prospective cardiac computed tomography and iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Hosch, Waldemar, E-mail: waldemar.hosch@med.uni-heidelberg.de [University of Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany); Stiller, Wolfram [University of Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany); Mueller, Dirk [Philips GmbH Healthcare Division, Hamburg (Germany); Gitsioudis, Gitsios [University of Heidelberg, Department of Cardiology, Heidelberg (Germany); Welzel, Johanna; Dadrich, Monika [University of Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany); Buss, Sebastian J.; Giannitsis, Evangelos [University of Heidelberg, Department of Cardiology, Heidelberg (Germany); Kauczor, Hans U. [University of Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany); Katus, Hugo A. [University of Heidelberg, Department of Cardiology, Heidelberg (Germany); Korosoglou, Grigorios, E-mail: gkorosoglou@hotmail.com [University of Heidelberg, Department of Cardiology, Heidelberg (Germany)

    2012-11-15

    Purpose: To assess the impact of body mass index (BMI)-adapted protocols and iterative reconstruction algorithms (iDose) on patient radiation exposure and image quality in patients undergoing prospective ECG-triggered 256-slice coronary computed tomography angiography (CCTA). Methods: Image quality and radiation exposure were systematically analyzed in 100 patients. 60 Patients underwent prospective ECG-triggered CCTA using a non-tailored protocol and served as a 'control' group (Group 1: 120 kV, 200 mA s). 40 Consecutive patients with suspected coronary artery disease (CAD) underwent prospective CCTA, using BMI-adapted tube voltage and standard (Group 2: 100/120 kV, 100-200 mA s) versus reduced tube current (Group 3: 100/120 kV, 75-150 mA s). Iterative reconstructions were provided with different iDose levels and were compared to filtered back projection (FBP) reconstructions. Image quality was assessed in consensus of 2 experienced observers and using a 5-grade scale (1 = best to 5 = worse), and signal- and contrast-to-noise ratios (SNR and CNR) were quantified. Results: CCTA was performed without adverse events in all patients (n = 100, heart rate of 47-87 bpm and BMI of 19-38 kg/m{sup 2}). Patients examined using the non-tailored protocol in Group 1 had the highest radiation exposure (3.2 {+-} 0.4 mSv), followed by Group 2 (1.7 {+-} 0.7 mSv) and Group 3 (1.2 {+-} 0.6 mSv) (radiation savings of 47% and 63%, respectively, p < 0.001). Iterative reconstructions provided increased SNR and CNR, particularly when higher iDose level 5 was applied with Multi-Frequency reconstruction (iDose5 MFR) (14.1 {+-} 4.6 versus 21.2 {+-} 7.3 for SNR and 12.0 {+-} 4.2 versus 18.1 {+-} 6.6 for CNR, for FBP versus iDose5 MFR, respectively, p < 0.001). The combination of BMI adaptation with iterative reconstruction reduced radiation exposure and simultaneously improved image quality (subjective image quality of 1.4 {+-} 0.4 versus 1.9 {+-} 0.5 for Group 2 reconstructed using

  2. A technique for multi-dimensional optimization of radiation dose, contrast dose, and image quality in CT imaging

    Science.gov (United States)

    Sahbaee, Pooyan; Abadi, Ehsan; Sanders, Jeremiah; Becchetti, Marc; Zhang, Yakun; Agasthya, Greeshma; Segars, Paul; Samei, Ehsan

    2016-03-01

    The purpose of this study was to substantiate the interdependency of image quality, radiation dose, and contrast material dose in CT towards the patient-specific optimization of the imaging protocols. The study deployed two phantom platforms. First, a variable sized phantom containing an iodinated insert was imaged on a representative CT scanner at multiple CTDI values. The contrast and noise were measured from the reconstructed images for each phantom diameter. Linearly related to iodine-concentration, contrast to noise ratio (CNR), was calculated for different iodine-concentration levels. Second, the analysis was extended to a recently developed suit of 58 virtual human models (5D-XCAT) with added contrast dynamics. Emulating a contrast-enhanced abdominal image procedure and targeting a peak-enhancement in aorta, each XCAT phantom was "imaged" using a CT simulation platform. 3D surfaces for each patient/size established the relationship between iodine-concentration, dose, and CNR. The Sensitivity of Ratio (SR), defined as ratio of change in iodine-concentration versus dose to yield a constant change in CNR was calculated and compared at high and low radiation dose for both phantom platforms. The results show that sensitivity of CNR to iodine concentration is larger at high radiation dose (up to 73%). The SR results were highly affected by radiation dose metric; CTDI or organ dose. Furthermore, results showed that the presence of contrast material could have a profound impact on optimization results (up to 45%).

  3. Postoperative Radiation Therapy for Non-Small Cell Lung Cancer and Thymic Malignancies

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Daniel R., E-mail: dgomez@mdanderson.org; Komaki, Ritsuko [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1840 Old Spanish Trail, Houston, TX 77054 (United States)

    2012-03-14

    For many thoracic malignancies, surgery, when feasible, is the preferred upfront modality for local control. However, adjuvant radiation plays an important role in minimizing the risk of locoregional recurrence. Tumors in the thoracic category include certain subgroups of non-small cell lung cancer (NSCLC) as well as thymic malignancies. The indications, radiation doses, and treatment fields vary amongst subtypes of thoracic tumors, as does the level of data supporting the use of radiation. For example, in the setting of NSCLC, postoperative radiation is typically reserved for close/positive margins or N2/N3 disease, although such diseases as superior sulcus tumors present unique cases in which the role of neoadjuvant vs. adjuvant treatment is still being elucidated. In contrast, for thymic malignancies, postoperative radiation therapy is often used for initially resected Masaoka stage III or higher disease, with its use for stage II disease remaining controversial. This review provides an overview of postoperative radiation therapy for thoracic tumors, with a separate focus on superior sulcus tumors and thymoma, including a discussion of acceptable radiation approaches and an assessment of the current controversies involved in its use.

  4. The Quality Control of Intensity Modulated Radiation Therapy (IMRT for ONCOR Siemens Linear Accelerators Using Film Dosimetry

    Directory of Open Access Journals (Sweden)

    Keyvan Jabbari

    2012-03-01

    Full Text Available Introduction Intensity Modulated Radiation Therapy (IMRT has made a significant progress in radiation therapy centers in recent years. In this method, each radiation beam is divided into many subfields that create a field with a modulated intensity. Considering the complexity of this method, the quality control for IMRT is a topic of interest for researchers. This article is about the various steps of planning and quality control of Siemens linear accelerators for IMRT, using film dosimetry. This article in addition to review of the techniques, discusses the details of experiments and possible sources of errors which are not mentioned in the protocols and other references. Materials and Methods This project was carried out in Isfahan Milad hospital which has two Siemens ONCOR linear accelerators. Both accelerators are equipped with Multi-Leaf Collimators (MLC which enables us to perform IMRT delivery in the step-and-shoot method. The quality control consists of various experiments related to the sections of radiation therapy. In these experiments, the accuracy of some components such as treatment planning system, imaging device (CT, MLC, control system of accelerator, and stability of the output are evaluated. The dose verification is performed using film dosimetry method. The films were KODAK-EDR2, which were calibrated before the experiments. One of the important steps is the comparison of the calculated dose with planning system and the measured dose in experiments. Results The results of the experiments in various steps have been acceptable according to the standard protocols. The calibration of MLC and evaluation of the leakage through the leaves of MLC was performed by using the film dosimetry and visual check. In comparison with calculated and measured dose, more that 80% of the points have to be in agreement within 3% of the value. In our experiments, between 85 and 90% of the points had such an agreement with IMRT delivery. Conclusion

  5. Ionizing Radiation Impacts on Cardiac Differentiation of Mouse Embryonic Stem Cells

    Science.gov (United States)

    Helm, Alexander; Arrizabalaga, Onetsine; Pignalosa, Diana; Schroeder, Insa S.; Durante, Marco

    2016-01-01

    Little is known about the effects of ionizing radiation on the earliest stages of embryonic development although it is well recognized that ionizing radiation is a natural part of our environment and further exposure may occur due to medical applications. The current study addresses this issue using D3 mouse embryonic stem cells as a model system. Cells were irradiated with either X-rays or carbon ions representing sparsely and densely ionizing radiation and their effect on the differentiation of D3 cells into spontaneously contracting cardiomyocytes through embryoid body (EB) formation was measured. This study is the first to demonstrate that ionizing radiation impairs the formation of beating cardiomyocytes with carbon ions being more detrimental than X-rays. However, after prolonged culture time, the number of beating EBs derived from carbon ion irradiated cells almost reached control levels indicating that the surviving cells are still capable of developing along the cardiac lineage although with considerable delay. Reduced EB size, failure to downregulate pluripotency markers, and impaired expression of cardiac markers were identified as the cause of compromised cardiomyocyte formation. Dysregulation of cardiac differentiation was accompanied by alterations in the expression of endodermal and ectodermal markers that were more severe after carbon ion irradiation than after exposure to X-rays. In conclusion, our data show that carbon ion irradiation profoundly affects differentiation and thus may pose a higher risk to the early embryo than X-rays. PMID:26506910

  6. MicroRNA-22 promotes cell survival upon UV radiation by repressing PTEN

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Guangyun [Department of Pathology and Laboratory Medicine, University of Tennessee Health Science Center, Memphis, TN (United States); Center for Adult Cancer Research, University of Tennessee Health Science Center, Memphis, TN (United States); Jilin Province Key Laboratory of Animal Embryo Engineering, Jilin University, Changchun (China); Shi, Yuling [Department of Pathology and Laboratory Medicine, University of Tennessee Health Science Center, Memphis, TN (United States); Center for Adult Cancer Research, University of Tennessee Health Science Center, Memphis, TN (United States); Wu, Zhao-Hui, E-mail: zwu6@uthsc.edu [Department of Pathology and Laboratory Medicine, University of Tennessee Health Science Center, Memphis, TN (United States); Center for Adult Cancer Research, University of Tennessee Health Science Center, Memphis, TN (United States)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer miR-22 is induced in cells treated with UV radiation. Black-Right-Pointing-Pointer ATM is required for miR-22 induction in response to UV. Black-Right-Pointing-Pointer miR-22 targets 3 Prime -UTR of PTEN to repress its expression in UV-treated cells. Black-Right-Pointing-Pointer Upregulated miR-22 inhibits apoptosis in cells exposed to UV. -- Abstract: DNA damage response upon UV radiation involves a complex network of cellular events required for maintaining the homeostasis and restoring genomic stability of the cells. As a new class of players involved in DNA damage response, the regulation and function of microRNAs in response to UV remain poorly understood. Here we show that UV radiation induces a significant increase of miR-22 expression, which appears to be dependent on the activation of DNA damage responding kinase ATM (ataxia telangiectasia mutated). Increased miR-22 expression may result from enhanced miR-22 maturation in cells exposed to UV. We further found that tumor suppressor gene phosphatase and tensin homolog (PTEN) expression was inversely correlated with miR-22 induction and UV-induced PTEN repression was attenuated by overexpression of a miR-22 inhibitor. Moreover, increased miR-22 expression significantly inhibited the activation of caspase signaling cascade, leading to enhanced cell survival upon UV radiation. Collectively, these results indicate that miR-22 is an important player in the cellular stress response upon UV radiation, which may promote cell survival via the repression of PTEN expression.

  7. Analysis of resveratrol and radiation effects in lung cancer cells by micronucleus assay

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Carolina S.; Santos, Dymes R.A.; Vieira, Daniel P.; Rogero, Sizue O.; Rogero, Jose R., E-mail: carolina_sm@hotmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Sakuraba, Roberto K.; Weltman, Eduardo [Hospital Israelita Albert Einstein, Sao Paulo, SP (Brazil); Cruz, Aurea S.; Santos, Rezolina P. [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil)

    2015-07-01

    Mucoepidermoid lung carcinoma is frequently manifested by obstructive trachea symptoms. Radiation and drugs combinations are commonly used in the lung cancer treatment. Currently there is a strong tendency to develop therapeutic strategies focused at the administration of high potential compounds to improve the ionizing radiation treatments, so as to increase the radiation effects on tumor cell while minimizing these effects to surrounding normal tissues. Resveratrol is a polyphenolic phytoalexin compound present in wines and several plants. This compound has a broad spectrum of biological activities such as antioxidant, anticarcinogenic, and induction of cell cycle arrest effects. Analysis of biological effects of ionizing radiation in the presence of resveratrol in different cell cultures has been the subject of many studies. To verify the genotoxic effects in cells exposed to ionizing radiation many methods have been proposed. The cytokinesis-block micronucleus technique is one of the preferred methods. The main of this study was to detect and quantify radioinduced DNA damage in mucoepidermoid lung carcinoma cells (NCI-H292) by cytokinesis-block micronucleus technique using cytocalasin-B. The cell culture was irradiated at a single fraction from a TrueBeam® linear accelerator (0, 0.8, 5, and 10 Gy), in the absence or presence of different resveratrol concentrations (0, 15, 30, and 60 μM). The results showed that resveratrol (15 and μM) induced significant increase frequency (p<0.05) of micronucleus formation in NCI-H292 cell culture non-irradiated and exposed at 5 Gy dose. Moreover, resveratrol (30 μM) induced micronucleus formation at 0.8 Gy dose. (author)

  8. Subcurative radiation significantly increases cell proliferation, invasion, and migration of primary glioblastoma multiforme in vivo

    Institute of Scientific and Technical Information of China (English)

    Adarsh Shankar; Robert A. Knight; Stephen Brown; Ali S. Arbab; Sanath Kumar; Asm Iskander; Nadimpalli RS Varma; Branislava Janic; Ana deCarvalho; Tom Mikkelsen; Joseph A. Frank; Meser M. Ali

    2014-01-01

    Tumor cellproliferation, infiltration, migration, and neovascularization are known causes of treatment resistance in glioblastoma multiforme (GBM). The purpose of this study was to determine the effect of radiation on the growth characteristics of primary human GBM developed in a nude rat. Primary GBM cells grown from explanted GBM tissues were implanted orthotopically in nude rats. Tumor growth was confirmed by magnetic resonance imaging on day 77 (baseline) after implantation. The rats underwent irradiation to a dose of 50 Gy delivered subcuratively on day 84 postimplantation (n= 8), or underwent no radiation (n= 8). Brain tissues were obtained on day 112 (nonirradiated) or day 133 (irradiated). Immunohistochemistry was performed to determine tumor cell proliferation (Ki-67) and to assess the expression of infiltration marker (matrix metalloproteinase-2, MMP-2) and cell migration marker (CD44). Tumor neovascularization was assessed by microvessel density using von-Willebrand factor (vWF) staining. Magnetic resonance imaging showed well-developed, infiltrative tumors in 11 weeks postimplantation. The proportion of Ki-67-positive cells in tumors undergoing radiation was (71 ± 15)%compared with (25 ± 12)%in the nonirradiated group (P=0.02). The number of MMP-2-positive areas and proportion of CD44-positive cells were also high in tumors receiving radiation, indicating great invasion and infiltration. Microvessel density analysis did not show a significant difference between nonirradiated and irradiated tumors. Taken together, we found that subcurative radiation significantly increased proliferation, invasion, and migration of primary GBM. Our study provides insights into possible mechanisms of treatment resistance fol owing radiation therapy for GBM.

  9. Mechanisms underlying cellular responses of cells from haemopoietic tissue to low dose/low LET radiation

    Energy Technology Data Exchange (ETDEWEB)

    Munira A Kadhim

    2010-03-05

    To accurately define the risks associated with human exposure to relevant environmental doses of low LET ionizing radiation, it is necessary to completely understand the biological effects at very low doses (i.e., less than 0.1 Gy), including the lowest possible dose, that of a single electron track traversal. At such low doses, a range of studies have shown responses in biological systems which are not related to the direct interaction of radiation tracks with DNA. The role of these “non-targeted” responses in critical tissues is poorly understood and little is known regarding the underlying mechanisms. Although critical for dosimetry and risk assessment, the role of individual genetic susceptibility in radiation risk is not satisfactorily defined at present. The aim of the proposed grant is to critically evaluate radiation-induced genomic instability and bystander responses in key stem cell populations from haemopoietic tissue. Using stem cells from two mouse strains (CBA/H and C57BL/6J) known to differ in their susceptibility to radiation effects, we plan to carefully dissect the role of genetic predisposition on two non-targeted radiation responses in these models; the bystander effect and genomic instability, which we believe are closely related. We will specifically focus on the effects of low doses of low LET radiation, down to doses approaching a single electron traversal. Using conventional X-ray and γ-ray sources, novel dish separation and targeted irradiation approaches, we will be able to assess the role of genetic variation under various bystander conditions at doses down to a few electron tracks. Irradiations will be carried out using facilities in routine operation for bystander targeted studies. Mechanistic studies of instability and the bystander response in different cell lineages will focus initially on the role of cytokines which have been shown to be involved in bystander signaling and the initiation of instability. These studies also aim

  10. Raman spectroscopy identifies radiation response in human non-small cell lung cancer xenografts

    Science.gov (United States)

    Harder, Samantha J.; Isabelle, Martin; Devorkin, Lindsay; Smazynski, Julian; Beckham, Wayne; Brolo, Alexandre G.; Lum, Julian J.; Jirasek, Andrew

    2016-02-01

    External beam radiation therapy is a standard form of treatment for numerous cancers. Despite this, there are no approved methods to account for patient specific radiation sensitivity. In this report, Raman spectroscopy (RS) was used to identify radiation-induced biochemical changes in human non-small cell lung cancer xenografts. Chemometric analysis revealed unique radiation-related Raman signatures that were specific to nucleic acid, lipid, protein and carbohydrate spectral features. Among these changes was a dramatic shift in the accumulation of glycogen spectral bands for doses of 5 or 15 Gy when compared to unirradiated tumours. When spatial mapping was applied in this analysis there was considerable variability as we found substantial intra- and inter-tumour heterogeneity in the distribution of glycogen and other RS spectral features. Collectively, these data provide unique insight into the biochemical response of tumours, irradiated in vivo, and demonstrate the utility of RS for detecting distinct radiobiological responses in human tumour xenografts.

  11. Mitochondria are involved in apoptosis induced by ultraviolet radiation in lepidopteran Spodoptera litura cell line

    Institute of Scientific and Technical Information of China (English)

    Shigang Shan; Kaiyu Liu; Jianxin Peng; Hanchao Yao; Yi Li; Huazhu Hong

    2009-01-01

    Mitochondria are involved in apoptosis of mammalian cells and even single-cell organisms, but mitochondria are not required in apoptosis in cultured Drosophila cells such as S2 and BG2 cell lines. It is not very clear whether mitochondria are involved in apoptosis in other insect cells such as lepidopteran cell lines. Thus, we determined to elucidate the role of mitochondria in apoptosis induced by ultraviolet radiation in Spodoptera litura (Lepidoptera: Noctuidae) cell line (SL-ZSU-1). The Western blot results suggested that cytochrome c in the ultraviolet-treated SL-1 cells was released from the mitochondria to cytosol as early as 4 h after the induction of ultraviolet radiation and increased in the cytosolic fractions in a time-dependent manner. Flow cytometric analysis of mitochondrial membrane potential (△Ψm) of SL-ZSU-1 cell treated with ultraviolet-C (UV-C) light indicated the decrease in mitochondrial membrane potential was dependent on the times of ultraviolet treatment. Both of them are different from apoptosis in cultured Drosophila melanogaster cell lines (S2 and BG2) and it appears evident mitochondria are involved in apoptosis of the studied lepidopteran cells.

  12. Multinucleated Giant Cancer Cells Produced in Response to Ionizing Radiation Retain Viability and Replicate Their Genome

    Science.gov (United States)

    Mirzayans, Razmik; Andrais, Bonnie; Scott, April; Wang, Ying W.; Kumar, Piyush; Murray, David

    2017-01-01

    Loss of wild-type p53 function is widely accepted to be permissive for the development of multinucleated giant cells. However, whether therapy-induced multinucleation is associated with cancer cell death or survival remains controversial. Herein, we demonstrate that exposure of p53-deficient or p21WAF1 (p21)-deficient solid tumor-derived cell lines to ionizing radiation (between 2 and 8 Gy) results in the development of multinucleated giant cells that remain adherent to the culture dish for long times post-irradiation. Somewhat surprisingly, single-cell observations revealed that virtually all multinucleated giant cells that remain adherent for the duration of the experiments (up to three weeks post-irradiation) retain viability and metabolize 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT), and the majority (>60%) exhibit DNA synthesis. We further report that treatment of multinucleated giant cells with pharmacological activators of apoptosis (e.g., sodium salicylate) triggers their demise. Our observations reinforce the notion that radiation-induced multinucleation may reflect a survival mechanism for p53/p21-deficient cancer cells. With respect to evaluating radiosensitivity, our observations underscore the importance of single-cell experimental approaches (e.g., single-cell MTT) as the creation of viable multinucleated giant cells complicates the interpretation of the experimental data obtained by commonly-used multi-well plate colorimetric assays. PMID:28208747

  13. Protein disulphide isomerase as a target for nanoparticle-mediated sensitisation of cancer cells to radiation

    Science.gov (United States)

    Taggart, L. E.; McMahon, S. J.; Butterworth, K. T.; Currell, F. J.; Schettino, G.; Prise, K. M.

    2016-05-01

    Radiation resistance and toxicity in normal tissues are limiting factors in the efficacy of radiotherapy. Gold nanoparticles (GNPs) have been shown to be effective at enhancing radiation-induced cell death, and were initially proposed to physically enhance the radiation dose deposited. However, biological responses of GNP radiosensitization based on physical assumptions alone are not predictive of radiosensitisation and therefore there is a fundamental research need to determine biological mechanisms of response to GNPs alone and in combination with ionising radiation. This study aimed to identify novel mechanisms of cancer cell radiosensitisation through the use of GNPs, focusing on their ability to induce cellular oxidative stress and disrupt mitochondrial function. Using N-acetyl-cysteine, we found mitochondrial oxidation to be a key event prior to radiation for the radiosensitisation of cancer cells and suggests the overall cellular effects of GNP radiosensitisation are a result of their interaction with protein disulphide isomerase (PDI). This investigation identifies PDI and mitochondrial oxidation as novel targets for radiosensitisation.

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

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Byung Yeoup; Kim, Jin Hong; Lee, Seung Sik; Kim, Jae Sung; An, Byung Chull; Moon, Yu Ran; Lee, Eun Mi; Lee, Min Hee; Lee, Jae Tack [KAERI, Daejeon (Korea, Republic of)

    2010-02-15

    The purpose of this project is improvement of investigation, materialization and evaluation techniques on effectiveness for functional natural compounds throughout development of tissue/cell culture techniques for mass production of useful metabolites using radiation. Research scope includes 1) Development of a technique for radiation tissue and cell culture, 2) Database construction for radiation response in plants and radiation effects, 3) Construction of general-purpose national based techniques of cell culture technique using radiation. Main results are as follow: mass culture of the adventitious roots of mountain ginseng (Panax ginseng C. A. Meyer) roots using rare earth elements in bioreactor: characterization of a transcription factor EoP gene from centipedegrass and the transcription regulation of LexA from Synechocystis sp PCC6803 and E. coli: identification of gamma-ray induced hydrogenase synthesis in hox gene transformed E. coli: transformation and the selection of the EoP transgene from Arabidopsis, rice and lettuce: Identification of the maysin and maysin derivatives in centipedegrass: characterization of gamma-ray induced color change in Taxus cuspidata: verification of the expression of antioxidant proteins (POD, APX and CAT) to gamma-ray in Arabidopsis: comparison of the response of the expression level to gamma-ray or H{sub 2}O{sub 2} in Arabidopsis; verification of the responses and effects to gamma-ray from plants (analysis of NPQ and ROS levels): the development method for rapidly enhancing maysin content of centipede grass; establishment of mass culture system for red beet

  15. Optical fiber detectors as in-vivo dosimetry method of quality assurance in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Plazas, M.C. [Universidad Nacional de Colombia, Bogota (Colombia). Physics Dept. Medical Physics Group; Justus, B.L.; Falkenstein, P.; Huston, A.L. [Naval Research Laboratory, Washington, DC (United States). Optical Sciences Div.; Ning, H.; Miller, R. [National Cancer Institute, Bethesda, MD (United States). Radiation Oncology Branch

    2004-07-01

    A new in-vivo dosimetry system has been under development for some time using radio luminescent phosphors. These phosphors are activated, metal ion doped glasses (Ex: Cu{sup 1{+-}} doped quartz fiber), have excellent optical transparency and offer several potential advantages for radiation dosimetry; including: small size, high sensitivity, linearity of dose response insensitivity to electromagnetic interference. The utility of these phosphors as a detection modality has been limited in real-time dosimetry applications due to the production of Cerenkov radiation in the carrier fiber, which produces a contaminant signal proportional to dose rate as well as the size of the radiation field. One possible method for eliminating this signal is using an electronic gating signal from the accelerator to delay data acquisition during the actual beam pulse, when Cerenkov radiation is produced. Due to the intrinsic properties of our particular scintillator, this method offers the best mechanism for eliminating Cerenkov noise, while retaining the ability to detect individual beam pulses. The dosimeter was tested using an external beam radiotherapy machine that provided pulses of 6 MeV x-rays. Gated detection was used to discriminate the signal collected during the radiation pulses, which included contributions from Cerenkov radiation and native fiber fluorescence, from the signal collected between the radiation pulses, which contained only the long-lived phosphorescence from the Cu{sup 1{+-}} doped fused quartz detector. Gated detection of the phosphorescence provided accurate, real-time dose measurements that were linear with absorbed dose, independent of dose rate and that were accurate for all field sizes studied. (author)

  16. Radiation dose optimization in pediatric temporal bone computed tomography: influence of tube tension on image contrast and image quality

    Energy Technology Data Exchange (ETDEWEB)

    Nauer, Claude Bertrand [University Hospital Berne, Institute of Diagnostic and Interventional Neuroradiology, Berne (Switzerland); Zentrales Roentgeninstitut, Kantonsspital Graubuenden, Chur (Switzerland); Zubler, Christoph; Weisstanner, Christian [University Hospital Berne, Institute of Diagnostic and Interventional Neuroradiology, Berne (Switzerland); Stieger, Christof [University Berne, Group for Artificial Hearing Research, ARTORG Center, Berne (Switzerland); Senn, Pascal [University Hospital Berne, Department of ENT, Head and Neck Surgery, Berne (Switzerland); Arnold, Andreas [University Berne, Group for Artificial Hearing Research, ARTORG Center, Berne (Switzerland); University Hospital Berne, Department of ENT, Head and Neck Surgery, Berne (Switzerland)

    2012-03-15

    The purpose of this experimental study was to investigate the effect of tube tension reduction on image contrast and image quality in pediatric temporal bone computed tomography (CT). Seven lamb heads with infant-equivalent sizes were scanned repeatedly, using four tube tensions from 140 to 80 kV while the CT-Dose Index (CTDI) was held constant. Scanning was repeated with four CTDI values from 30 to 3 mGy. Image contrast was calculated for the middle ear as the Hounsfield unit (HU) difference between bone and air and for the inner ear as the HU difference between bone and fluid. The influence of tube tension on high-contrast detail delineation was evaluated using a phantom. The subjective image quality of eight middle and inner ear structures was assessed using a 4-point scale (scores 1-2 = insufficient; scores 3-4 = sufficient). Middle and inner ear contrast showed a near linear increase with tube tension reduction (r = -0.94/-0.88) and was highest at 80 kV. Tube tension had no influence on spatial resolution. Subjective image quality analysis showed significantly better scoring at lower tube tensions, with highest image quality at 80 kV. However, image quality improvement was most relevant for low-dose scans. Image contrast in the temporal bone is significantly higher at low tube tensions, leading to a better subjective image quality. Highest contrast and best quality were found at 80 kV. This image quality improvement might be utilized to further reduce the radiation dose in pediatric low-dose CT protocols. (orig.)

  17. Effects of Radiation on Proteasome Function in Prostate Cancer Cells

    Science.gov (United States)

    2012-02-01

    vol/vol] Nonidet P - 40 and 20% glycerol) were added to the cells, and the mixtures were vortexed for 1 minute. Beads and cell debris were removed by...20 40 60 80 G1 S G2/M % o f t ot al p op ul at io n PC3 0 2 4 6 8 10 0.01 0.1 1 Non-stopped 0h 6h Dose (Gy) Su rv iv in g fr ac tio n Fig. 1...between 0 and 40 %, suggesting that proteasomes are far more dynamic than we initially thought. A major discovery in year 2 and 3 was the

  18. Radiative thermal escape in intermediate band solar cells

    Directory of Open Access Journals (Sweden)

    A. Luque

    2011-06-01

    Full Text Available To achieve high efficiency, the intermediate band (IB solar cell must generate photocurrent from sub-bandgap photons at a voltage higher than that of a single contributing sub-bandgap photon. To achieve the latter, it is necessary that the IB levels be properly isolated from the valence and conduction bands. We prove that this is not the case for IB cells formed with the confined levels of InAs quantum dots (QDs in GaAs grown so far due to the strong density of internal thermal photons at the transition energies involved. To counteract this, the QD must be smaller.

  19. Simulation of TGF-Beta Activation by Low-Dose HZE Radiation in a Cell Culture

    Science.gov (United States)

    Plante, Ianik; Cucinotta, Francis A.

    2009-01-01

    High charge (Z) and energy (E) (HZE) nuclei comprised in the galactic cosmic rays are main contributors to space radiation risk. They induce many lesions in living matter such as non-specific oxidative damage and the double-strand breaks (DSBs), which are considered key precursors of early and late effects of radiation. There is increasing evidence that cells respond collectively rather than individually to radiation, suggesting the importance of cell signaling1. The transforming growth factor (TGF ) is a signaling peptide that is expressed in nearly all cell type and regulates a large array of cellular processes2. TGF have been shown to mediate cellular response to DNA damage3 and to induce apoptosis in non-irradiated cells cocultured with irradiated cells4. TFG molecules are secreted by cells in an inactive complex known as the latency-associated peptide (LAP). TGF is released from the LAP by a conformational change triggered by proteases, thrombospondin-1, integrins, acidic conditions and .OH radical5. TGF then binds to cells receptors and activates a cascade of events mediated by Smad proteins6, which might interfere with the repair of DNA. Meanwhile, increasingly sophisticated Brownian Dynamics (BD) algorithms have appeared recently in the literature7 and can be applied to study the interaction of molecules with receptors. These BD computer models have contributed to the elucidation of signal transduction, ligand accumulation and autocrine loops in the epidermal growth factor (EGF) and its receptor (EFGR) system8. To investigate the possible roles of TGF in an irradiated cell culture, our Monte-Carlo simulation codes of the radiation track structure9 will be used to calculate the activation of TFG triggered by .OH produced by low doses of HZE ions. The TGF molecules will then be followed by a BD algorithm in a medium representative of a cell culture to estimate the number of activated receptors.

  20. Realization of radiobiological in vitro cell experiments at conventional X-ray tubes and unconventional radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Beyreuther, Elke

    2010-09-10

    More than hundred years after the discovery of X-rays different kinds of ionizing radiation are ubiquitous in medicine, applied to clinical diagnostics and cancer treatment as well. Irrespective of their nature, the widespread application of radiation implies its precise dosimetric characterization and detailed knowledge of the radiobiological effects induced in cancerous and normal tissue. Starting with in vitro cell irradiation experiments, which define basic parameters for the subsequent tissue and animal studies, the whole multi-stage process is completed by clinical trials that translate the results of fundamental research into clinical application. In this context, the present dissertation focuses on the establishment of radiobiological in vitro cell experiments at unconventional, but clinical relevant radiation qualities. In the first part of the present work the energy dependent biological effectiveness of photons was studied examining low-energy X-rays (≤ 50 keV), as used for mammography, and high-energy photons (≥ 20 MeV) as proposed for future radiotherapy. Cell irradiation experiments have been performed at conventional X-ray tubes providing low-energy photons and 200 kV reference radiation as well. In parallel, unconventional quasi-monochromatic channeling X-rays and high-energy bremsstrahlung available at the radiation source ELBE of the Forschungszentrum Dresden-Rossendorf were considered for radiobiological experimentation. For their precise dosimetric characterization dosimeters based on the thermally stimulated emission of exoelectrons and on radiochromic films were evaluated, whereas just the latter was found to be suitable for the determination of absolute doses and spatial dose distributions at cell position. Standard ionization chambers were deployed for the online control of cell irradiation experiments. Radiobiological effects were analyzed in human mammary epithelial cells on different subcellular levels revealing an increasing amount

  1. Influence of femtosecond laser radiation on cells of the transplantable tumour Krebs-2

    Science.gov (United States)

    Meshalkin, Yu P.; Popova, N. A.; Nikolin, V. P.; Kaledin, V. I.; Kirpichnikov, A. V.; Pestryakov, Efim V.

    2012-06-01

    The influence of femtosecond radiation of a titaniumsapphire laser on cells of the transplantable ascitic tumour Krebs-2 was studied. After in vitro irradiation by the pulsed fundamentalharmonic radiation with the wavelength 800 nm, pulse duration 30 fs, repetition rate 1 kHz, mean power 100 and 300 mW and exposure time 3 min, as well as by the second-harmonic radiation (40 nm, 50 fs, 120 mW), all cells were diffusely stained by the vital stain trypan blue, which may be an evidence of their death or abnormalities of membrane permeability. However, implantation of such cells to experimental animals led to formation of tumours at the transplantation site with the kinetics slightly different from the control one. In the group of mice to which the cells were inoculated after irradiation with second harmonic pulses of titanium-sapphire laser the inhibition of tumour growth was observed due to partial death of cells under the action of UV spectral components. To explain the mechanism of the observed phenomenon the possibility of pore formation (photoporation) in the cell membrane, described earlier in the papers on foreign DNA transfection into cells, is considered.

  2. Influence of femtosecond laser radiation on cells of the transplantable tumour Krebs-2

    Energy Technology Data Exchange (ETDEWEB)

    Meshalkin, Yu P; Popova, N A; Nikolin, V P; Kaledin, V I; Kirpichnikov, A V; Pestryakov, Efim V

    2012-06-30

    The influence of femtosecond radiation of a titaniumsapphire laser on cells of the transplantable ascitic tumour Krebs-2 was studied. After in vitro irradiation by the pulsed fundamentalharmonic radiation with the wavelength 800 nm, pulse duration 30 fs, repetition rate 1 kHz, mean power 100 and 300 mW and exposure time 3 min, as well as by the second-harmonic radiation (40 nm, 50 fs, 120 mW), all cells were diffusely stained by the vital stain trypan blue, which may be an evidence of their death or abnormalities of membrane permeability. However, implantation of such cells to experimental animals led to formation of tumours at the transplantation site with the kinetics slightly different from the control one. In the group of mice to which the cells were inoculated after irradiation with second harmonic pulses of titanium-sapphire laser the inhibition of tumour growth was observed due to partial death of cells under the action of UV spectral components. To explain the mechanism of the observed phenomenon the possibility of pore formation (photoporation) in the cell membrane, described earlier in the papers on foreign DNA transfection into cells, is considered.

  3. Isolation and characterization of human salivary gland cells for stem cell transplantation to reduce radiation-induced hyposalivation

    NARCIS (Netherlands)

    Feng, Jielin; van der Zwaag, Marianne; Stokman, Monique A.; van Os, Ronald; Coppes, Robert P.

    2009-01-01

    Background: Recently, we showed that transplantation of 100-300 c-Kit(+) stem cells isolated from cultured salispheres ameliorates radiation-damage in murine salivary glands. The aim of this study is to optimize and translate these findings from mice to man. Methods: Mouse and human non-malignant pa

  4. Mutual Radiation Impedance of Uncollapsed CMUT Cells with Different Radii

    CERN Document Server

    Ozgurluk, Alper; Atalar, Abdullah; Koymen, Hayrettin

    2015-01-01

    A polynomial approximation is proposed for the mutual acoustic impedance between uncollapsed capacitive micromachined ultrasonic transducer (CMUT) cells with different radii in an infinite rigid baffle. The resulting approximation is employed in simulating CMUTs with a circuit model. A very good agreement is obtained with the corresponding finite element simulation (FEM) result.

  5. Live-cell imaging to detect phosphatidylserine externalization in brain endothelial cells exposed to ionizing radiation: implications for the treatment of brain arteriovenous malformations.

    Science.gov (United States)

    Zhao, Zhenjun; Johnson, Michael S; Chen, Biyi; Grace, Michael; Ukath, Jaysree; Lee, Vivienne S; McRobb, Lucinda S; Sedger, Lisa M; Stoodley, Marcus A

    2016-06-01

    OBJECT Stereotactic radiosurgery (SRS) is an established intervention for brain arteriovenous malformations (AVMs). The processes of AVM vessel occlusion after SRS are poorly understood. To improve SRS efficacy, it is important to understand the cellular response of blood vessels to radiation. The molecular changes on the surface of AVM endothelial cells after irradiation may also be used for vascular targeting. This study investigates radiation-induced externalization of phosphatidylserine (PS) on endothelial cells using live-cell imaging. METHODS An immortalized cell line generated from mouse brain endothelium, bEnd.3 cells, was cultured and irradiated at different radiation doses using a linear accelerator. PS externalization in the cells was subsequently visualized using polarity-sensitive indicator of viability and apoptosis (pSIVA)-IANBD, a polarity-sensitive probe. Live-cell imaging was used to monitor PS externalization in real time. The effects of radiation on the cell cycle of bEnd.3 cells were also examined by flow cytometry. RESULTS Ionizing radiation effects are dose dependent. Reduction in the cell proliferation rate was observed after exposure to 5 Gy radiation, whereas higher radiation doses (15 Gy and 25 Gy) totally inhibited proliferation. In comparison with cells treated with sham radiation, the irradiated cells showed distinct pseudopodial elongation with little or no spreading of the cell body. The percentages of pSIVA-positive cells were significantly higher (p = 0.04) 24 hours after treatment in the cultures that received 25- and 15-Gy doses of radiation. This effect was sustained until the end of the experiment (3 days). Radiation at 5 Gy did not induce significant PS externalization compared with the sham-radiation controls at any time points (p > 0.15). Flow cytometric analysis data indicate that irradiation induced growth arrest of bEnd.3 cells, with cells accumulating in the G2 phase of the cell cycle. CONCLUSIONS Ionizing radiation

  6. PSA Solar furnace: A facility for testing PV cells under concentrated solar radiation

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Reche, J.; Canadas, I.; Sanchez, M.; Ballestrin, J.; Yebra, L.; Monterreal, R.; Rodriguez, J.; Garcia, G. [Concentration Solar Technologies, Plataforma Solar de Almeria-CIEMAT P.O. Box 22, Tabernas, E-04200 (Almeria) (Spain); Alonso, M.; Chenlo, F. [Photovoltaic Components and Systems, Renewable Energies Department-CIEMAT Avda. Complutense, 22, Madrid, E-28040 (Spain)

    2006-09-22

    The Plataforma Solar de Almeria (PSA), the largest centre for research, development and testing of concentration solar thermal technologies in Europe, has started to apply its knowledge, facilities and resources to development of the Concentration PV technology in an EU-funded project HiConPV. A facility for testing PV cells under solar radiation concentrated up to 2000x has recently been completed. The advantages of this facility are that, since it is illuminated by solar radiation, it is possible to obtain the appropriate cell spectral response directly, and the flash tests can be combined with prolonged PV-cell irradiation on large surfaces (up to 150cm{sup 2}), so the thermal response of the PV cell can be evaluated simultaneously. (author)

  7. Knowledge-based iterative model reconstruction: comparative image quality and radiation dose with a pediatric computed tomography phantom

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Young Jin; Choi, Young Hun [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Cheon, Jung-Eun; Kim, Woo Sun; Kim, In-One [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Ha, Seongmin [New York-Presbyterian Hospital and the Weill Cornell Medical College, Dalio Institute of Cardiovascular Imaging, New York, NY (United States)

    2016-03-15

    CT of pediatric phantoms can provide useful guidance to the optimization of knowledge-based iterative reconstruction CT. To compare radiation dose and image quality of CT images obtained at different radiation doses reconstructed with knowledge-based iterative reconstruction, hybrid iterative reconstruction and filtered back-projection. We scanned a 5-year anthropomorphic phantom at seven levels of radiation. We then reconstructed CT data with knowledge-based iterative reconstruction (iterative model reconstruction [IMR] levels 1, 2 and 3; Philips Healthcare, Andover, MA), hybrid iterative reconstruction (iDose{sup 4}, levels 3 and 7; Philips Healthcare, Andover, MA) and filtered back-projection. The noise, signal-to-noise ratio and contrast-to-noise ratio were calculated. We evaluated low-contrast resolutions and detectability by low-contrast targets and subjective and objective spatial resolutions by the line pairs and wire. With radiation at 100 peak kVp and 100 mAs (3.64 mSv), the relative doses ranged from 5% (0.19 mSv) to 150% (5.46 mSv). Lower noise and higher signal-to-noise, contrast-to-noise and objective spatial resolution were generally achieved in ascending order of filtered back-projection, iDose{sup 4} levels 3 and 7, and IMR levels 1, 2 and 3, at all radiation dose levels. Compared with filtered back-projection at 100% dose, similar noise levels were obtained on IMR level 2 images at 24% dose and iDose{sup 4} level 3 images at 50% dose, respectively. Regarding low-contrast resolution, low-contrast detectability and objective spatial resolution, IMR level 2 images at 24% dose showed comparable image quality with filtered back-projection at 100% dose. Subjective spatial resolution was not greatly affected by reconstruction algorithm. Reduced-dose IMR obtained at 0.92 mSv (24%) showed similar image quality to routine-dose filtered back-projection obtained at 3.64 mSv (100%), and half-dose iDose{sup 4} obtained at 1.81 mSv. (orig.)

  8. Human salivary gland stem cells ameliorate hyposalivation of radiation-damaged rat salivary glands.

    Science.gov (United States)

    Jeong, Jaemin; Baek, Hyunjung; Kim, Yoon-Ju; Choi, Youngwook; Lee, Heekyung; Lee, Eunju; Kim, Eun Sook; Hah, Jeong Hun; Kwon, Tack-Kyun; Choi, Ik Joon; Kwon, Heechung

    2013-11-15

    Salivary function in mammals may be defective for various reasons, such as aging, Sjogren's syndrome or radiation therapy in head and neck cancer patients. Recently, tissue-specific stem cell therapy has attracted public attention as a next-generation therapeutic reagent. In the present study, we isolated tissue-specific stem cells from the human submandibular salivary gland (hSGSCs). To efficiently isolate and amplify hSGSCs in large amounts, we developed a culture system (lasting 4-5 weeks) without any selection. After five passages, we obtained adherent cells that expressed mesenchymal stem cell surface antigen markers, such as CD44, CD49f, CD90 and CD105, but not the hematopoietic stem cell markers, CD34 and CD45, and that were able to undergo adipogenic, osteogenic and chondrogenic differentiation. In addition, hSGSCs were differentiated into amylase-expressing cells by using a two-step differentiation method. Transplantation of hSGSCs to radiation-damaged rat salivary glands rescued hyposalivation and body weight loss, restored acinar and duct cell structure, and decreased the amount of apoptotic cells. These data suggest that the isolated hSGSCs, which may have characteristics of mesenchymal-like stem cells, could be used as a cell therapy agent for the damaged salivary gland.

  9. Enhancement of radiation cytotoxicity in breast-cancer cells by localized attachment of gold nanoparticles.

    Science.gov (United States)

    Kong, Tao; Zeng, Jie; Wang, Xiaoping; Yang, Xiaoyan; Yang, Jing; McQuarrie, Steve; McEwan, Alexander; Roa, Wilson; Chen, Jie; Xing, James Z

    2008-09-01

    Gold nanoparticles (GNPs) and modified GNPs having two kinds of functional molecules, cysteamine (AET) and thioglucose (Glu), are synthesized. Cell uptake and radiation cytotoxicity enhancement in a breast-cancer cell line (MCF-7) versus a nonmalignant breast-cell line (MCF-10A) are studied. Transmission electron microscopy (TEM) results show that cancer cells take up functional Glu-GNPs significantly more than naked GNPs. The TEM results also indicate that AET-capped GNPs are mostly bound to the MCF-7 cell membrane, while Glu-GNPs enter the cells and are distributed in the cytoplasm. After MCF-7 cell uptake of Glu-GNPs, or binding of AET-GNPs, the in vitro cytotoxicity effects are observed at 24, 48, and 72 hours. The results show that these functional GNPs have little or no toxicity to these cells. To validate the enhanced killing effect on cancer cells, various forms of radiation are applied such as 200 kVp X-rays and gamma-rays, to the cells, both with and without functional GNPs. By comparison with irradiation alone, the results show that GNPs significantly enhance cancer killing.

  10. Isolation and Characterization of Radiation-resistant Lung Cancer D6-R Cell Line

    Institute of Scientific and Technical Information of China (English)

    QI-CHUN WEI; LI SHEN; SHU ZHENG; YONG-LIANG ZHU

    2008-01-01

    To isolate an isogenic radioresistant cancer cell line after fractioned X-ray radiation and characterize the resistant cells. Methods D6 cells were exposed to repeated X-ray irradiation, and after a total dose of 5200 cGy in 8 fractions, a radioresistant monoclone D6-R was obtained. The radiosensitivity and drug sensitivity of the novel radioresistant D6-R cells, together with their parent D6 cells, were measured using clonogenic assay and MTT assay respectively. Cell cycle distribution was analyzed by flow cytometry. Fluorescence microscopy and flow cytometry were applied for apoptosis detection. Comet assay was used for the detection of DNA damage and repair. Results D6-R cells showed higher and broader initial shoulder (D=2.08 Gy, D=1.64 Gy, N=2.20) than the parent D6 ceils (D=1.84 Gy, D=0.34 Gy, N=1.20). They were 1.65-fold more radioresistant than D6 cells in terms of SF(63% vs 38%) and were more resistant to ADM (3.15-fold) and 5-FU (3.86-fold) as compared with the latter. It was found that D6-R cells had higher fractions of cells in S phase (53.4% vs 37.8%) and lower fractions of ceils in G(44.1% vs 57.2%) and G-M phase (2.5% vs 5%). There was no difference in radiation-induced apoptosis between D6-R and D6 cells. D6-R cells showed less initial DNA damage and increased capacity in DNA repair after irradiation, as compared with the parent cells. Conclusions D6-R cells have been isolated by exposing the parental D6 cells to repeated irradiation. The difference in cell cycle pattern together with the induction and repair of DNA damage might, at least partially, explain the mechanism of the radioresistance.

  11. 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.

  12. Gene expression profile of Jurkat cells exposed to high power terahertz radiation

    Science.gov (United States)

    Grundt, Jessica E.; Roth, Caleb C.; Rivest, Benjamin D.; Doroski, Michael L.; Payne, Jason; Ibey, Bennett L.; Wilmink, Gerald J.

    2011-03-01

    Terahertz (THz) radiation sources are now being used in a host of military, defense, and medical applications. Widespread employment of these applications has prompted concerns regarding the health effects associated with THz radiation. In this study, we examined the gene expression profile of mammalian cells exposed to THz radiation. We hypothesized that if THz radiation couples directly to cellular constituents, then exposed cells may express a specific gene expression profile indicative of ensuing damage. To test this hypothesis, Jurkat cells were irradiated with a molecular gas THz laser (2.52 THz, 636 mWcm-2, durations: 5, 10, 20, 30, 40, or 50 minutes). Viability was assessed 24 h post-exposure using MTT assays, and gene expression profiles were evaluated 4 h post-exposure using mRNA microarrays. Comparable analyses were also performed for hyperthermic positive controls (44°C for 40 minutes). We found that cellular temperatures increased by ~6 °C during THz exposures. We also found that cell death increased with exposure duration, and the median lethal dose (LD50) was calculated to be ~44 minutes. The microarray data showed that THz radiation induced the transcriptional activation of genes associated with cellular proliferation, differentiation, transcriptional activation, chaperone protein stabilization, and apoptosis. For most genes, we found that the magnitude of differential expression was comparable for both the THz and thermal exposure groups; however, several genes were specifically activated by the THz exposure. These results suggest that THz radiation may elicit effects that are not exclusively due to the temperature rise created during THz exposures (i.e. thermal effects). In future work, we plan to verify the results of our microarray experiments using qPCR techniques.

  13. CDC27 protein is involved in radiation response in squamous cell cervix carcinoma.

    Science.gov (United States)

    Rajkumar, T; Gopal, G; Selvaluxmi, G; Rajalekshmy, K R

    2005-10-01

    In the present study, an attempt was made to identify genes involved in radiation response in cervix carcinoma. Differential display technique was used to study the expression profiles of tumour biopsy samples obtained from patients, responding and not responding to treatment. The samples were obtained prior to radiotherapy and subsequent to treatment with Tele-radiation at 10 Gray (Gy). One of the differentially expressed cDNAs, when sequenced was identified to be CDC27. Immuno-histochemical analysis of pre- and post-treated tumour samples from fifteen patients showed the downregulation of expression of CDC27 protein in seven patients. Down-regulation was associated with poorer response to radiotherapy. Cervical cancer cell lines SiHa and C33A were irradiated and their nuclei were stained for expression of CDC27 and analyzed using fluorescent-activated cell sorting (FACS). Down-regulation of CDC27 protein in the irradiated SiHa cell line was associated with greater survival fraction, compared to the irradiated C33A cell line, which had only slight fall in the level of CDC27 protein. This is the first study to suggest a role for CDC27 in radiation response. However, a larger cohort is needed to further confirm the value of CDC27 protein as a predictive marker, for radiation response in cervix cancer.

  14. Effects of pre-radiation exposure to LLLT of normal and malignant cells

    NARCIS (Netherlands)

    A. Barasch; J. Raber-Durlacher; J.B. Epstein; J. Carroll

    2016-01-01

    Purpose: Low-level laser therapy (LLLT) efficacy for the prevention of cancer treatment-induced oral mucositis (OM) has been amply described. However, potential protection of malignant cells remains a legitimate concern for clinicians. We tested LLLT-induced protection from ionizing radiation killin

  15. Red blood cell glutathione levels in lung cancer patients treated by radiation and continuously infused carboplatin

    NARCIS (Netherlands)

    Groen, HJM; Meijer, C; DeVries, EGE; Mulder, NH

    1996-01-01

    Intrinsic resistance in non-small cell lung cancer (NSCLC) curtails the efficacy of chemotherapy and radiotherapy. Glutathione (GSH) may be one of the factors responsible for this phenomenon as it counteracts the cytotoxic effects of platinum containing drugs and radiation. GSH levels were studied i

  16. Th2-polarized CD4+ T cells and macrophages limit efficacy of radiation therapy

    OpenAIRE

    Shiao, Stephen L.; Ruffell, Brian; DeNardo, David G.; Faddegon, Bruce A; Park, Catherine C.; Coussens, Lisa M.

    2015-01-01

    Radiation therapy (RT) and chemotherapy (CTX) following surgery are mainstays of treatment for breast cancer (BC). While multiple studies have recently revealed the significance of immune cells as mediators of CTX response in BC, less is known regarding roles for leukocytes as mediating outcomes following RT. To address this, we utilized a syngeneic orthotopic murine model of mammary carcinogenesis to investigate if response to RT could be improved when select immune cells or immune-based pat...

  17. Concomitant treatment of F98 glioma cells with new liposomal platinum compounds and ionizing radiation

    OpenAIRE

    Charest, Gabriel; Paquette, Benoit; Fortin, David; Mathieu, David; Sanche, Léon

    2009-01-01

    Despite significant advances, the radiotherapy and chemotherapy protocols marginally improve the overall survival of patients with glioblastoma. Lipoplatin™, and Lipoxal™, the liposomal formulations of cisplatin and oxaliplatin respectively, were tested on the F98 glioma cells for their ability to improve the cell uptake and increase the synergic effect when combined with ionizing radiation. The cytotoxicity and synergic effect of platinum compounds were assessed by colony formation assay, wh...

  18. Development of a model system to study leukotriene-induced modification of radiation sensitivity in mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Walden, T.L. Jr.; Holahan, E.V. Jr.; Catravas, G.N.

    1986-01-01

    Leukotrienes (LT) are an important class of biological mediators for which no information exists concerning their synthesis following a radiation insult or on their ability to modify cellular response to a subsequent radiation exposure. Results are presented which illustrate that the Chinese hamster lung fibroblast cell line, V79A03, is useful as a model system to study the metabolic fate of leukotrienes and the effect of LT on radiation sensitivity of mammalian cells in vitro. (U.K.).

  19. Radiation Pneumonitis After Stereotactic Body Radiation Therapy for Early Stage Non-small Cell Lung Cancer%早期非小细胞肺癌立体定向放射治疗后的放射性肺炎

    Institute of Scientific and Technical Information of China (English)

    陈露; 赵娅琴; 许峰

    2014-01-01

    With the development of radiation technology, stereotactic body radiation therapy (SBRT) has been widely used in early stage non-small cell lung cancer (NSCLC). It is not only the standard therapy for medically inoperable early-stage NSCLC, but also one of the therapies for operable early-stage NSCLC. Radiation pneumonitis (RP) is one of the most common adverse effects atfer SBRT, it may reduce the patients’ quality of life, even cause treatment failure. hTerefore, in order to improve the patients’ quality of life and enhance local control rate of tumor, it is important to reduce the risk of RP. hTe unique fractionation schemes and the dose distribution of SBRT make it not only different from conventional fraction radiation therapy in treatment outcomes, but also in the incidence of radiation pneumonitis. hTis article reviews the applying of SBRT for early stage NSCLC, the incidence of radiation pneumonitis, radiological appearance atfer SBRT and predictive factors.%随着放疗技术的进步,立体定向放射治疗(stereotactic body radiation therapy, SBRT)在早期非小细胞肺癌(non-small cell lung cancer, NSCLC)中得到了广泛应用,其不仅是不可手术的早期NSCLC的标准治疗方法,也是可手术的早期NSCLC的治疗方法之一。放射性肺炎(radiation pneumonitis, RP)是SBRT治疗后最常见的并发症。SBRT独特的分割计划和剂量分布使其不仅在治疗效果上和常规分割放疗不同,而且治疗后引起的RP和常规分割放疗引起的RP也有所不同。RP的发生可降低患者的生活质量,甚至导致治疗失败。因此,降低RP的风险对提高患者的生活质量和肿瘤的控制率有重要意义。本文就SBRT在早期NSCLC治疗中应用、治疗后RP的发生率、影像学表现以及预测因素方面作一综述。

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Nonlinearity in MCF7 Cell Survival Following Exposure to Modulated 6 MV Radiation Fields

    Directory of Open Access Journals (Sweden)

    Laetitia Lacoste-Collin MD, PhD

    2015-10-01

    Full Text Available The study of cell survival following exposure to nonuniform radiation fields is taking on particular interest because of the increasing evidence of a nonlinear relationship at low doses. We conducted in vitro experiments using the MCF7 breast cancer cell line. A 2.4 × 2.4 cm2 square area of a T25 flask was irradiated by a Varian Novalis accelerator delivering 6 MV photons. Cell survival inside the irradiation field, in the dose gradient zone and in the peripheral zone, was determined using a clonogenic assay for different radiation doses at the isocenter. Increased cell survival was observed inside the irradiation area for doses of 2, 10, and 20 Gy when nonirradiated cells were present at the periphery, while the cells at the periphery showed decreased survival compared to controls. Increased survival was also observed at the edge of the dose gradient zone for cells receiving 0.02 to 0.01 Gy when compared with cells at the periphery of the same flask, whatever the isocenter dose. These data are the first to report cell survival in the dose gradient zone. Radiotherapists must be aware of this nonlinearity in dose response.

  2. Nonlinearity in MCF7 Cell Survival Following Exposure to Modulated 6 MV Radiation Fields

    Science.gov (United States)

    Castiella, Marion; Franceries, Xavier; Cassol, Emmanuelle; Vieillevigne, Laure; Pereda, Veronica; Bardies, Manuel; Courtade-Saïdi, Monique

    2015-01-01

    The study of cell survival following exposure to nonuniform radiation fields is taking on particular interest because of the increasing evidence of a nonlinear relationship at low doses. We conducted in vitro experiments using the MCF7 breast cancer cell line. A 2.4 × 2.4 cm2 square area of a T25 flask was irradiated by a Varian Novalis accelerator delivering 6 MV photons. Cell survival inside the irradiation field, in the dose gradient zone and in the peripheral zone, was determined using a clonogenic assay for different radiation doses at the isocenter. Increased cell survival was observed inside the irradiation area for doses of 2, 10, and 20 Gy when nonirradiated cells were present at the periphery, while the cells at the periphery showed decreased survival compared to controls. Increased survival was also observed at the edge of the dose gradient zone for cells receiving 0.02 to 0.01 Gy when compared with cells at the periphery of the same flask, whatever the isocenter dose. These data are the first to report cell survival in the dose gradient zone. Radiotherapists must be aware of this nonlinearity in dose response. PMID:26740805

  3. BIIB021, a novel Hsp90 inhibitor, sensitizes esophageal squamous cell carcinoma to radiation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin-Tong; Bao, Ci-Hang; Jia, Yi-Bin; Wang, Nana [Department of Radiation Oncology, Qilu Hospital of Shandong University, Jinan 250012 (China); Ma, Wei [Department of Radiation Oncology, Cancer Hospital, General Hospital of Ningxia Medical University, Yinchuan 750000 (China); Liu, Fang [Medical Imaging, Shandong Medical College, Jinan 250002 (China); Wang, Cong; Wang, Jian-Bo; Song, Qing-Xu [Department of Radiation Oncology, Qilu Hospital of Shandong University, Jinan 250012 (China); Cheng, Yu-Feng, E-mail: qlcyf1965@126.com [Department of Radiation Oncology, Qilu Hospital of Shandong University, Jinan 250012 (China)

    2014-10-03

    Highlights: • BIIB021 downregulated radioresistant proteins in ESCC cell lines. • BIIB021 increased radiation-induced apoptotic cells. • BIIB021 enhanced G{sub 2} arrest in ESCC cell lines. • BIIB021 is a good candidate for radiosensitizer in radiotherapy of ESCC patients. - Abstract: BIIB021 is a novel, orally available inhibitor of heat shock protein 90 (Hsp90) that is currently in phase I/II clinical trials. BIIB021 induces the apoptosis of various types of tumor cells in vitro and in vivo. The aim of this study is to investigate the effect of BIIB021 on the radiosensitivity of esophageal squamous cell carcinoma (ESCC). The results indicated that BIIB021 exhibited strong antitumor activity in ESCC cell lines, either as a single agent or in combination with radiation. BIIB021 significantly downregulated radioresistant proteins including EGFR, Akt, Raf-1 of ESCC cell lines, increased apoptotic cells and enhanced G{sub 2} arrest that is more radiosensitive cell cycle phase. These results suggest that this synthetic Hsp90 inhibitor simultaneously affects multiple pathways involved in tumor development and progression in the ESCC setting and may represent a better strategy for the treatment of ESCC patients, either as a monotherapy or a radiosensitizer.

  4. Original Research: Label-free detection for radiation-induced apoptosis in glioblastoma cells.

    Science.gov (United States)

    Qi, Dandan; Feng, Jingwen; Yang, Chengwen; Jin, Changrong; Sa, Yu; Feng, Yuanming

    2016-10-01

    Current flow cytometry (FCM) requires fluorescent dyes labeling cells which make the procedure costly and time consuming. This manuscript reports a feasibility study of detecting the cell apoptosis with a label-free method in glioblastoma cells. A human glioma cell line M059K was exposed to 8 Gy dose of radiation, which enables the cells to undergo radiation-induced apoptosis. The rates of apoptosis were studied at different time points post-irradiation with two different methods: FCM in combination with Annexin V-FITC/PI staining and a newly developed technique named polarization diffraction imaging flow cytometry. Totally 1000 diffraction images were acquired for each sample and the gray level co-occurrence matrix (GLCM) algorithm was used in morphological characterization of the apoptotic cells. Among the feature parameters extracted from each image pair, we found that the two GLCM parameters of angular second moment (ASM) and sum entropy (SumEnt) exhibit high sensitivities and consistencies as the apoptotic rates (Pa) measured with FCM method. In addition, no significant difference exists between Pa and ASM_S, Pa and SumEnt_S, respectively (P > 0.05). These results demonstrated that the new label-free method can detect cell apoptosis effectively. Cells can be directly used in the subsequent biochemical experiments as the structure and function of cells and biomolecules are well-preserved with this new method.

  5. Repair-dependent cell radiation survival and transformation: an integrated theory.

    Science.gov (United States)

    Sutherland, John C

    2014-09-07

    The repair-dependent model of cell radiation survival is extended to include radiation-induced transformations. The probability of transformation is presumed to scale with the number of potentially lethal damages that are repaired in a surviving cell or the interactions of such damages. The theory predicts that at doses corresponding to high survival, the transformation frequency is the sum of simple polynomial functions of dose; linear, quadratic, etc, essentially as described in widely used linear-quadratic expressions. At high doses, corresponding to low survival, the ratio of transformed to surviving cells asymptotically approaches an upper limit. The low dose fundamental- and high dose plateau domains are separated by a downwardly concave transition region. Published transformation data for mammalian cells show the high-dose plateaus predicted by the repair-dependent model for both ultraviolet and ionizing radiation. For the neoplastic transformation experiments that were analyzed, the data can be fit with only the repair-dependent quadratic function. At low doses, the transformation frequency is strictly quadratic, but becomes sigmodial over a wider range of doses. Inclusion of data from the transition region in a traditional linear-quadratic analysis of neoplastic transformation frequency data can exaggerate the magnitude of, or create the appearance of, a linear component. Quantitative analysis of survival and transformation data shows good agreement for ultraviolet radiation; the shapes of the transformation components can be predicted from survival data. For ionizing radiations, both neutrons and x-rays, survival data overestimate the transforming ability for low to moderate doses. The presumed cause of this difference is that, unlike UV photons, a single x-ray or neutron may generate more than one lethal damage in a cell, so the distribution of such damages in the population is not accurately described by Poisson statistics. However, the complete

  6. Evaluation of Late Effects of Heavy-Ion Radiation on Mesenchymal Stem Cells

    Science.gov (United States)

    Gonda, S.R.; Behravesh, E.; Huff, J.L.; Johnson, F.

    2005-01-01

    The overall objective of this recently funded study is to utilize well-characterized model test systems to assess the impact of pluripotent stem cell differentiation on biological effects associated with high-energy charged particle radiation. These stem cells, specifically mesenchymal stem cells (MSCs), have the potential for differentiation into bone, cartilage, fat, tendons, and other tissue types. The characterization of the regulation mechanisms of MSC differentiation to the osteoblastic lineage by transcription factors, such as Runx2/Cbfa1 and Osterix, and osteoinductive proteins such as members of the bone morphogenic protein family are well established. More importantly, for late biological effects, MSCs have been shown to contribute to tissue restructuring and repair after tissue injury. The complex regulation of and interactions between inflammation and repair determine the eventual outcome of the responses to tissue injury, for which MSCs play a crucial role. Additionally, MSCs have been shown to respond to reactive oxygen species, a secondary effector of radiation, by differentiating. With this, we hypothesized that differentiation of MSCs can alter or exacerbate the damage initiated by radiation, which can ultimately lead to late biological effects of misrepair/fibrosis which may ultimately lead to carcinogenesis. Currently, studies are underway to examine high-energy X-ray radiation at low and high doses, approximately 20 and 200 Rad, respectively, on cytogenetic damage and gene modulation of isolated MSCs. These cells, positive for MSC surface markers, were obtained from three persons. In vitro cell samples were harvested during cellular proliferation and after both cellular recovery and differentiation. Future work will use established in vitro models of increasing complexity to examine the value of traditional 2D tissue-culture techniques, and utilize 3D in vitro tissue culture techniques that can better assess late effects associated with

  7. Hydroxyurea and sickle cell anemia: effect on quality of life

    Directory of Open Access Journals (Sweden)

    Pegelow Charles H

    2006-08-01

    Full Text Available Abstract Background The Multicenter Study of Hydroxyurea (HU in Sickle Cell Anemia (MSH previously showed that daily oral HU reduces painful sickle cell (SS crises by 50% in patients with moderate to severe disease. The morbidity associated with this disease is known to have serious negative impact on the overall quality of life(QOL of affected individuals. Methods The data in this report were collected from the 299 patients enrolled in the MSH. Health quality of llife (HQOL measures were assessed in the MSH as a secondary endpoint to determine if the clinical benefit of HU could translate into a measurable benefit perceptible to the patients. HQOL was assessed with the Profile of Mood States, the Health Status Short Form 36 (SF-36, including 4-week pain recall, and the Ladder of Life, self-administered twice 2-weeks apart pre-treatment and every 6 months during the two-year, randomized, double-blind, treatment phase. The effects of factors including randomized treatment, age, gender, pre-treatment crises frequency, Hb-F level mean, daily pain from 4-week pre-treatment diaries, and 2-year Hb-F response level (low or high were investigated. Results Over two years of treatment, the benefit of HU treatment on QOL, other than pain scales, was limited to those patients taking HU who maintained a high HbF response, compared to those with low HbF response or on placebo. These restricted benefits occurred in social function, pain recall and general health perception. Stratification according to average daily pain prior to treatment showed that responders to HU whose average daily pain score was 5–9 (substantial pain achieved significant reduction in the tension scale compared to the placebo group and to non-responders. HU had no apparent effect on other QOL measures. Conclusion Treatment of SS with HU improves some aspects of QOL in adult patients who already suffer from moderate-to-severe SS.

  8. Hydroxyurea and sickle cell anemia: effect on quality of life

    Science.gov (United States)

    Ballas, Samir K; Barton, Franca B; Waclawiw, Myron A; Swerdlow, Paul; Eckman, James R; Pegelow, Charles H; Koshy, Mabel; Barton, Bruce A; Bonds, Duane R

    2006-01-01

    Background The Multicenter Study of Hydroxyurea (HU) in Sickle Cell Anemia (MSH) previously showed that daily oral HU reduces painful sickle cell (SS) crises by 50% in patients with moderate to severe disease. The morbidity associated with this disease is known to have serious negative impact on the overall quality of life(QOL) of affected individuals. Methods The data in this report were collected from the 299 patients enrolled in the MSH. Health quality of llife (HQOL) measures were assessed in the MSH as a secondary endpoint to determine if the clinical benefit of HU could translate into a measurable benefit perceptible to the patients. HQOL was assessed with the Profile of Mood States, the Health Status Short Form 36 (SF-36), including 4-week pain recall, and the Ladder of Life, self-administered twice 2-weeks apart pre-treatment and every 6 months during the two-year, randomized, double-blind, treatment phase. The effects of factors including randomized treatment, age, gender, pre-treatment crises frequency, Hb-F level mean, daily pain from 4-week pre-treatment diaries, and 2-year Hb-F response level (low or high) were investigated. Results Over two years of treatment, the benefit of HU treatment on QOL, other than pain scales, was limited to those patients taking HU who maintained a high HbF response, compared to those with low HbF response or on placebo. These restricted benefits occurred in social function, pain recall and general health perception. Stratification according to average daily pain prior to treatment showed that responders to HU whose average daily pain score was 5–9 (substantial pain) achieved significant reduction in the tension scale compared to the placebo group and to non-responders. HU had no apparent effect on other QOL measures. Conclusion Treatment of SS with HU improves some aspects of QOL in adult patients who already suffer from moderate-to-severe SS. PMID:16942629

  9. Surgery for two cases with markedly impaired QOL(Quality of Life) of radiation enterocolitis

    Energy Technology Data Exchange (ETDEWEB)

    Shiba, Tadaaki; Tanishima, Satoru; Sato, Masahiko; Yanagisawa, Terumasa; Yoshino, Masaaki; Takatsuka, Jun [Toho Univ., Tokyo (Japan). School of Medicine

    1996-10-01

    Two cases of radiation enterocolitis with markedly impaired QOL for a long period were reported. Case 1: A 61 years old female. She received 60 Gy irradiation post hysterectomy and ovariectomy due to uterine cancer at the age of 39 y. She suffered from fecal incontinence and anal pain at 58 y, was diagnosed to have radiation colitis. She was hospitalized due to neurosis, anal pain and hypertension at 59 y. She received nephrostomy due to hydronephrosis and ureterostenosis at 60 y, and colostomy and ileal conduit formation due to anal pain and dyschezia. Case 2: A 70 years old female who received 60 Gy irradiation post surgery similar to case 1 at the age of 61 y. She suffered from ileus, intestinal retention and hydronephrosis thereafter. She was hospitalized due to metastasis of the cancer to sacred bone, and received further 40 Gy radiation therapy at the age of 65 y. Up to the present, she received several operations such as ileostomy, nephrostomy and hemorrhoids excision. It is important for surgeons to understand the actual QOL of patients with radiation enterocolitis. (K.H.)

  10. Decreasing the radiation quality factor of magnetic dipole antennas by a magnetic-coated metal core

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Breinbjerg, Olav

    2010-01-01

    To achieve the Chu lower bound for the radiation Q, an electrically small magnetic dipole antenna should not store any magnetic energy internally to the minimum sphere enclosing the antenna. As shown in our previous works, the internal stored magnetic energy can be reduced, although not entirely...

  11. Ionizing radiation selectively reduces skin regulatory T cells and alters immune function.

    Directory of Open Access Journals (Sweden)

    Yu Zhou

    Full Text Available The skin serves multiple functions that are critical for life. The protection from pathogens is achieved by a complicated interaction between aggressive effectors and controlling functions that limit damage. Inhomogeneous radiation with limited penetration is used in certain types of therapeutics and is experienced with exposure to solar particle events outside the protection of the Earth's magnetic field. This study explores the effect of ionizing radiation on skin immune function. We demonstrate that radiation, both homogeneous and inhomogeneous, induces inflammation with resultant specific loss of regulatory T cells from the skin. This results in a hyper-responsive state with increased delayed type hypersensitivity in vivo and CD4+ T cell proliferation in vitro. The effects of inhomogeneous radiation to the skin of astronauts or as part of a therapeutic approach could result in an unexpected enhancement in skin immune function. The effects of this need to be considered in the design of radiation therapy protocols and in the development of countermeasures for extended space travel.

  12. Ionizing Radiation Selectively Reduces Skin Regulatory T Cells and Alters Immune Function

    Science.gov (United States)

    Zhou, Yu; Ni, Houping; Balint, Klara; Sanzari, Jenine K.; Dentchev, Tzvete; Diffenderfer, Eric S.; Wilson, Jolaine M.; Cengel, Keith A.; Weissman, Drew

    2014-01-01

    The skin serves multiple functions that are critical for life. The protection from pathogens is achieved by a complicated interaction between aggressive effectors and controlling functions that limit damage. Inhomogeneous radiation with limited penetration is used in certain types of therapeutics and is experienced with exposure to solar particle events outside the protection of the Earth’s magnetic field. This study explores the effect of ionizing radiation on skin immune function. We demonstrate that radiation, both homogeneous and inhomogeneous, induces inflammation with resultant specific loss of regulatory T cells from the skin. This results in a hyper-responsive state with increased delayed type hypersensitivity in vivo and CD4+ T cell proliferation in vitro. The effects of inhomogeneous radiation to the skin of astronauts or as part of a therapeutic approach could result in an unexpected enhancement in skin immune function. The effects of this need to be considered in the design of radiation therapy protocols and in the development of countermeasures for extended space travel. PMID:24959865

  13. Histamine prevents radiation-induced mesenchymal changes in breast cancer cells.

    Science.gov (United States)

    Galarza, Tamara E; Mohamad, Nora A; Táquez Delgado, Mónica A; Vedoya, Guadalupe M; Crescenti, Ernesto J; Bergoc, Rosa M; Martín, Gabriela A; Cricco, Graciela P

    2016-09-01

    Radiotherapy is a prime option for treatment of solid tumors including breast cancer though side effects are usually present. Experimental evidence shows an increase in invasiveness of several neoplastic cell types through conventional tumor irradiation. The induction of epithelial to mesenchymal transition is proposed as an underlying cause of metastasis triggered by gamma irradiation. Experiments were conducted to investigate the role of histamine on the ionizing radiation-induced epithelial to mesenchymal transition events in breast cancer cells with different invasive phenotype. We also evaluated the potential involvement of Src phosphorylation in the migratory capability of irradiated cells upon histamine treatment. MCF-7 and MDA-MB-231 mammary tumor cells were exposed to a single dose of 2Gy of gamma radiation and five days after irradiation mesenchymal-like phenotypic changes were observed by optical microscope. The expression and subcellular localization of E-cadherin, β-catenin, vimentin and Slug were determined by immunoblot and indirect immunofluorescence. There was a decrease in the epithelial marker E-cadherin expression and an increase in the mesenchymal marker vimentin after irradiation. E-cadherin and β-catenin were mainly localized in cytoplasm. Slug positive nuclei, matrix metalloproteinase-2 activity and cell migration and invasion were significantly increased. In addition, a significant enhancement in Src phosphorylation/activation could be determined by immunoblot in irradiated cells. MCF-7 and MDA-MB-231 cells also received 1 or 20μM histamine during 24h previous to be irradiated. Notably, pre-treatment of breast cancer cells with 20μM histamine prevented the mesenchymal changes induced by ionizing radiation and also reduced the migratory behavior of irradiated cells decreasing phospho-Src levels. Collectively, our results suggest that histamine may block events related to epithelial to mesenchymal transition in irradiated mammary cancer

  14. Suppression of DNA-dependent protein kinase sensitize cells to radiation without affecting DSB repair.

    Science.gov (United States)

    Gustafsson, Ann-Sofie; Abramenkovs, Andris; Stenerlöw, Bo

    2014-11-01

    Efficient and correct repair of DNA double-strand break (DSB) is critical for cell survival. Defects in the DNA repair may lead to cell death, genomic instability and development of cancer. The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) is an essential component of the non-homologous end joining (NHEJ) which is the major DSB repair pathway in mammalian cells. In the present study, by using siRNA against DNA-PKcs in four human cell lines, we examined how low levels of DNA-PKcs affected cellular response to ionizing radiation. Decrease of DNA-PKcs levels by 80-95%, induced by siRNA treatment, lead to extreme radiosensitivity, similar to that seen in cells completely lacking DNA-PKcs and low levels of DNA-PKcs promoted cell accumulation in G2/M phase after irradiation and blocked progression of mitosis. Surprisingly, low levels of DNA-PKcs did not affect the repair capacity and the removal of 53BP1 or γ-H2AX foci and rejoining of DSB appeared normal. This was in strong contrast to cells completely lacking DNA-PKcs and cells treated with the DNA-PKcs inhibitor NU7441, in which DSB repair were severely compromised. This suggests that there are different mechanisms by which loss of DNA-PKcs functions can sensitize cells to ionizing radiation. Further, foci of phosphorylated DNA-PKcs (T2609 and S2056) co-localized with DSB and this was independent of the amount of DNA-PKcs but foci of DNA-PKcs was only seen in siRNA-treated cells. Our study emphasizes on the critical role of DNA-PKcs for maintaining survival after radiation exposure which is uncoupled from its essential function in DSB repair. This could have implications for the development of therapeutic strategies aiming to radiosensitize tumors by affecting the DNA-PKcs function.

  15. Physics strategies for sparing neural stem cells during whole-brain radiation treatments

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, Neil; Chuang, Cynthia; Pouliot, Jean; Hwang, Andrew; Barani, Igor J. [Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94143-1708 (United States)

    2011-10-15

    Purpose: Currently, there are no successful long-term treatments or preventive strategies for radiation-induced cognitive impairments, and only a few possibilities have been suggested. One such approach involves reducing the dose to neural stem cell compartments (within and outside of the hippocampus) during whole-brain radiation treatments for brain metastases. This study investigates the fundamental physics issues associated with the sparing of neural stem cells during photon radiotherapy for brain metastases. Methods: Several factors influence the stem cell dose: intracranial scattering, collimator leakage, beam energy, and total number of beams. The relative importance of these factors is investigated through a set of radiation therapy plans, which are all variations of an initial 6 MV intensity-modulated radiation therapy (IMRT) plan designed to simultaneously deliver a whole-brain dose of 30 Gy and maximally reduce stem cell compartment dose. Additionally, an in-house leaf segmentation algorithm was developed that utilizes jaw motion to minimize the collimator leakage. Results: The plans are all normalized such that 50% of the PTV receives 30 Gy. For the initial 6 MV IMRT plan, 50% of the stem cells receive a dose greater than 6.3 Gy. Calculations indicate that 3.6 Gy of this dose originates from intracranial scattering. The jaw-tracking segmentation algorithm, used in conjunction with direct machine parameter optimization, reduces the 50% stem cell dose to 4.3 and 3.7 Gy for 6 and 10 MV treatment beams, respectively. Conclusions: Intracranial scattering alone is responsible for a large dose contribution to the stem cell compartment. It is, therefore, important to minimize other contributing factors, particularly the collimator leakage, to maximally reduce dose to these critical structures. The use of collimator jaw tracking in conjunction with modern collimators can minimize this leakage.

  16. Low-level red laser therapy alters effects of ultraviolet C radiation on Escherichia coli cells

    Directory of Open Access Journals (Sweden)

    K.S. Canuto

    2015-01-01

    Full Text Available Low-level lasers are used at low power densities and doses according to clinical protocols supplied with laser devices or based on professional practice. Although use of these lasers is increasing in many countries, the molecular mechanisms involved in effects of low-level lasers, mainly on DNA, are controversial. In this study, we evaluated the effects of low-level red lasers on survival, filamentation, and morphology of Escherichia coli cells that were exposed to ultraviolet C (UVC radiation. Exponential and stationary wild-type and uvrA-deficient E. coli cells were exposed to a low-level red laser and in sequence to UVC radiation. Bacterial survival was evaluated to determine the laser protection factor (ratio between the number of viable cells after exposure to the red laser and UVC and the number of viable cells after exposure to UVC. Bacterial filaments were counted to obtain the percentage of filamentation. Area-perimeter ratios were calculated for evaluation of cellular morphology. Experiments were carried out in duplicate and the results are reported as the means of three independent assays. Pre-exposure to a red laser protected wild-type and uvrA-deficient E. coli cells against the lethal effect of UVC radiation, and increased the percentage of filamentation and the area-perimeter ratio, depending on UVC fluence and physiological conditions in the cells. Therapeutic, low-level red laser radiation can induce DNA lesions at a sub-lethal level. Consequences to cells and tissues should be considered when clinical protocols based on this laser are carried out.

  17. Low-level red laser therapy alters effects of ultraviolet C radiation on Escherichia coli cells

    Energy Technology Data Exchange (ETDEWEB)

    Canuto, K.S.; Guimaraes, O.R.; Geller, M. [Centro Universitario Serra dos Orgaos, Teresopolis, RJ (Brazil). Centro de Ciencias da Saude; Sergio, L.P.S. [Instituto de Biologia Roberto Alcantara Gomes, Rio de Janeiro, RJ (Brazil). Departamento de Biofisica e Biometria; Paoli, F. [Universidade Federal de Juiz de Fora (UFJF), Juiz de Fora, MG (Brazil). Departamento de Morfologia; Fonseca, A.S., E-mail: adnfonseca@ig.com.br [Universidade Federal do Estado do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Departamento de Ciencias Fisiologicas

    2015-10-15

    Low-level lasers are used at low power densities and doses according to clinical protocols supplied with laser devices or based on professional practice. Although use of these lasers is increasing in many countries, the molecular mechanisms involved in effects of low-level lasers, mainly on DNA, are controversial. In this study, we evaluated the effects of low-level red lasers on survival, filamentation, and morphology of Escherichia coli cells that were exposed to ultraviolet C (UVC) radiation. Exponential and stationary wild-type and uvrA-deficient E. coli cells were exposed to a low-level red laser and in sequence to UVC radiation. Bacterial survival was evaluated to determine the laser protection factor (ratio between the number of viable cells after exposure to the red laser and UVC and the number of viable cells after exposure to UVC). Bacterial filaments were counted to obtain the percentage of filamentation. Area-perimeter ratios were calculated for evaluation of cellular morphology. Experiments were carried out in duplicate and the results are reported as the means of three independent assays. Pre-exposure to a red laser protected wild-type and uvrA-deficient E. coli cells against the lethal effect of UVC radiation, and increased the percentage of filamentation and the area-perimeter ratio, depending on UVC fluence and physiological conditions in the cells. Therapeutic, low-level red laser radiation can induce DNA lesions at a sub-lethal level. Consequences to cells and tissues should be considered when clinical protocols based on this laser are carried out. (author)

  18. Frequency and quality of radiation monitoring of construction workers at two gaseous diffusion plants.

    Science.gov (United States)

    Bingham, Eula; Ringen, Knut; Dement, John; Cameron, Wilfrid; McGowan, William; Welch, Laura; Quinn, Patricia

    2006-09-01

    Construction workers were and are considered temporary workers at many construction sites. Since World War II, large numbers of construction workers were employed at U.S. Department of Energy nuclear weapons sites for periods ranging from a few days to over 30 years. These workers performed tasks during new construction and maintenance, repair, renovation, and demolition of existing facilities. Such tasks may involve emergency situations, and may entail opportunities for significant radiation exposures. This paper provides data from interviews with more than 750 construction workers at two gaseous diffusion plants (GDPs) at Paducah, Kentucky, and Portsmouth, Ohio regarding radiation monitoring practices. The aim was to determine the extent to which workers believed they were monitored during tasks involving potential radiation exposures. The adequacy of monitoring practices is important for two reasons: (a) Protecting workers from exposures: Construction workers were employed by sub-contractors, and may frequently been excluded from safety and health programs provided to permanent employees; and (b) Supporting claims for compensation: The Energy Employees Occupational Illness Compensation Program Act (EEOICPA) requires dose reconstruction of radiation exposures for most workers who file a claim regarding cancer. The use of monitoring data for radiation to qualify a worker means that there should be valid and complete monitoring during the work time at the various nuclear plants or workers may be unfairly denied compensation. The worker interviews from Paducah and Portsmouth were considered especially useful because these sites were designated as Special Exposure Cohorts (SECs) and the workers did not have to have a dose reconstruction to qualify for compensation for most cancers. Therefore, their responses were less likely to be affected by compensation concerns. Interview questions included asking for information regarding whether monitoring was performed, how

  19. Radiosensitivity and capacity for radiation-induced sublethal damage repair of canine transitional cell carcinoma (TCC) cell lines.

    Science.gov (United States)

    Parfitt, S L; Milner, R J; Salute, M E; Hintenlang, D E; Farese, J P; Bacon, N J; Bova, F J; Rajon, D A; Lurie, D M

    2011-09-01

    Understanding the inherent radiosensitivity and repair capacity of canine transitional cell carcinoma (TCC) can aid in optimizing radiation protocols to treat this disease. The objective of this study was to evaluate the parameters surviving fraction at 2 Gy (SF(2) ), α/β ratio and capacity for sublethal damage repair (SLDR) in response to radiation. Dose-response and split-dose studies were performed using the clonogenic assay. The mean SF(2) for three established TCC cell lines was high at 0.61. All the three cell lines exhibited a low to moderate α/β ratio, with the mean being 3.27. Two cell lines exhibited statistically increased survival at 4 and 24 h in the dose-response assay. Overall, our results indicate that the cell lines are moderately radioresistant, have a high repair capacity and behave similarly to a late-responding normal tissue. These findings indicate that the radiation protocols utilizing higher doses with less fractionation may be more effective for treating TCC.

  20. Mitochondrial mutant cells are hypersensitive to ionizing radiation, phleomycin and mitomycin C

    Energy Technology Data Exchange (ETDEWEB)

    Kulkarni, Rohan; Reither, Adrian; Thomas, Robert A. [Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Suite 1370, Detroit, MI 48202 (United States); Tucker, James D., E-mail: jtucker@biology.biosci.wayne.edu [Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Suite 1370, Detroit, MI 48202 (United States)

    2009-04-26

    Mitochondrial DNA (mtDNA) is an important contributor to the ATP-generating oxidative phosphorylation complex. Single nucleotide mutations in mitochondrial genes involved in ATP synthesis result in a broad range of diseases. Leber optic atrophy and Leigh's syndrome are two such diseases arising from point mutations in the mitochondrial genome. Here, ionizing radiation, phleomycin and mitomycin C (MMC) were used to induce structural chromosomal aberrations in Leber's and Leigh's cells to investigate how these mitochondrial mutations affect the cell's DNA repair processes. Because of the energy deprivation that results from mitochondrial mutations, we hypothesized that these mutant cells would demonstrate hypersensitivity when exposed to oxidative and genotoxic stress and we also expected that these cells would not be able to repair nuclear DNA damage as efficiently as normal cells. As a consequence, these mutant cells are expected to show increased levels of DNA damage, longer cell cycle delays and increased levels of cell death. Following acute radiation exposure these mutant cells showed an increase in the number of chromosomal aberrations and decreased mitotic indices when compared with normal human lymphoblastoid cells with wild-type mtDNA. When exposed to phleomycin or MMC, the mitochondrial mutant cells again showed hypersensitivity and decreased mitotic indices compared to normal cells. These results suggest that Leber's and Leigh's cells have an impaired ability to cope with oxidative and genotoxic stress. These observations may help explain the role of ATP generation in understanding the enhanced sensitivity of mitochondrial mutant cells to cancer therapeutic agents and to adverse environmental exposure, suggesting that individuals with mtDNA mutations may be at a greater risk for cancer and other diseases that result from an accumulation of nuclear DNA damage.

  1. Radiation-induced emission from golden hamster embryo cells

    Science.gov (United States)

    Miyazaki, Tetsuo; Nagasaka, Shigeru; Maeda, Isao; Matsumoto, Takuro; Koyama, Shinji; Kodama, Seiji; Watanabe, Masami

    1996-06-01

    Emission from high-energy-electron-irradiated golden hamster embryo (GHE) cells has been studied over the temperature range 12-300 K both by a one-shot-single-photon-counting method and by photocurrent measurements with an oscilloscope. Emission from the irradiated phosphate buffered saline (PBS) also has been studied. The emission spectra from PBS at 12 and 77 K show a maximum around 330 and 380 nm, respectively, which are the same spectra as those from irradiated pure H 2O. The emission from irradiated GHE consists of the new band at 480 nm in addition to the emission from H 2O. The 480 nm emission is observed at the temperature range of 12-300 K, though the emission at 300 K is much lower than that at low temperature. The 480 nm emission is ascribed to the transition from excited organic substances in GHE cells. The intensity of 480 nm emission at 300 K increases linearly with increasing irradiation-dose in the range of 11-600 Gy.

  2. Depression of p53-independent Akt survival signals after high-LET radiation in mutated p53 cells

    Science.gov (United States)

    Ohnishi, Takeo; Takahashi, Akihisa; Nakagawa, Yosuke

    Although mutations and deletions in the p53 tumor suppressor gene lead to resistance to low linear energy transfer (LET) radiation, high-LET radiation efficiently induces cell lethality and apoptosis regardless of the p53 gene status. Recently, it has been suggested that the induction of p53-independent apoptosis takes place through the activation of Caspase-9 which results in the cleavage of Caspase-3 and poly (ADP-ribose) polymerase (PARP). This study was designed to examine if high-LET radiation depresses the activities of serine/threonine protein kinase B (PKB, also known as Akt) and Akt-related proteins. Human gingival cancer cells (Ca9-22 cells) harboring a mutated p53 (mp53) gene were irradiated with 2 Gy of X-rays or Fe-ion beams. The cellular contents of Akt-related proteins participating in cell survival signals were analyzed with Western blotting analysis 1 h, 2 h, 3 h and 6 h after irradiation. Cell cycle distributions after irradiation were assayed with flow cytometric analysis.Akt-related protein levels were decreased when cells were irradiated with high-LET radiation. High-LET radiation increased G _{2}/M phase arrests and suppressed the progression of the cell cycle much more efficiently when compared to low-LET radiation. These results suggest that high-LET radiation enhances apoptosis through the activation of Caspase-3 and Caspase-9, and depresses cell growth by suppressing Akt-related signals, even in the mp53 cells.

  3. Cardiovascular CT angiography in neonates and children: Image quality and potential for radiation dose reduction with iterative image reconstruction techniques

    Energy Technology Data Exchange (ETDEWEB)

    Tricarico, Francesco [Medical University of South Carolina, Ashley River Tower, Department of Radiology and Radiological Science, Charleston, SC (United States); Catholic University of the Sacred Heart, ' ' A. Gemelli' ' Hospital, Department of Bioimaging and Radiological Sciences, Rome (Italy); Hlavacek, Anthony M. [Medical University of South Carolina, Ashley River Tower, Department of Radiology and Radiological Science, Charleston, SC (United States); Children' s Hospital, Medical University of South Carolina, Division of Pediatric Cardiology, Charleston, SC (United States); Schoepf, U.J. [Medical University of South Carolina, Ashley River Tower, Department of Radiology and Radiological Science, Charleston, SC (United States); Children' s Hospital, Medical University of South Carolina, Division of Pediatric Cardiology, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States); Ebersberger, Ullrich [Medical University of South Carolina, Ashley River Tower, Department of Radiology and Radiological Science, Charleston, SC (United States); Heart Centre Munich-Bogenhausen, Department of Cardiology and Intensive Care Medicine, Munich (Germany); Nance, John W. [Medical University of South Carolina, Ashley River Tower, Department of Radiology and Radiological Science, Charleston, SC (United States); Johns Hopkins Hospital, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Vliegenthart, Rozemarijn [Medical University of South Carolina, Ashley River Tower, Department of Radiology and Radiological Science, Charleston, SC (United States); University Medical Centre Groningen/University of Groningen, Centre for Medical Imaging - North East Netherlands, Department of Radiology, Groningen (Netherlands); Cho, Young Jun [Medical University of South Carolina, Ashley River Tower, Department of Radiology and Radiological Science, Charleston, SC (United States); Konyang University School of Medicine, Department of Radiology, Daejeon (Korea, Republic of); Spears, J.R. [Medical University of South Carolina, Ashley River Tower, Department of Radiology and Radiological Science, Charleston, SC (United States); Secchi, Francesco [Medical University of South Carolina, Ashley River Tower, Department of Radiology and Radiological Science, Charleston, SC (United States); University of Milan School of Medicine IRCCS Policlinico San Donato, Department of Medical and Surgical Sciences, Radiology Unit, Milan (Italy); Savino, Giancarlo; Marano, Riccardo; Bonomo, Lorenzo [Catholic University of the Sacred Heart, ' ' A. Gemelli' ' Hospital, Department of Bioimaging and Radiological Sciences, Rome (Italy); Schoenberg, Stefan O. [University Medical Centre Mannheim, Medical Faculty Mannheim - Heidelberg University, Institute of Clinical Radiology and Nuclear Medicine, Mannheim (Germany); Apfaltrer, Paul [Medical University of South Carolina, Ashley River Tower, Department of Radiology and Radiological Science, Charleston, SC (United States); University Medical Centre Mannheim, Medical Faculty Mannheim - Heidelberg University, Institute of Clinical Radiology and Nuclear Medicine, Mannheim (Germany)

    2013-05-15

    To evaluate image quality (IQ) of low-radiation-dose paediatric cardiovascular CT angiography (CTA), comparing iterative reconstruction in image space (IRIS) and sinogram-affirmed iterative reconstruction (SAFIRE) with filtered back-projection (FBP) and estimate the potential for further dose reductions. Forty neonates and children underwent low radiation CTA with or without ECG synchronisation. Data were reconstructed with FBP, IRIS and SAFIRE. For ECG-synchronised studies, half-dose image acquisitions were simulated. Signal noise was measured and IQ graded. Effective dose (ED) was estimated. Mean absolute and relative image noise with IRIS and full-dose SAFIRE was lower than with FBP (P < 0.001), while SNR and CNR were higher (P < 0.001). Image noise was also lower and SNR and CNR higher in half-dose SAFIRE studies compared with full-and half-dose FBP studies (P < 0.001). IQ scores were higher for IRIS, full-dose SAFIRE and half-dose SAFIRE than for full-dose FBP and higher for half-dose SAFIRE than for half-dose FBP (P < 0.05). Median weight-specific ED was 0.3 mSv without and 1.36 mSv with ECG synchronisation. The estimated ED of half-dose SAFIRE studies was 0.68 mSv. IR improves image noise, SNR, CNR and subjective IQ compared with FBP in low-radiation-dose paediatric CTA and allows further dose reductions without compromising diagnostic IQ. (orig.)

  4. Effects of electron radiation on shielded space triple-junction GaAs solar cells

    Institute of Scientific and Technical Information of China (English)

    Gao Xin; Yang Sheng-Sheng; Xue Yu-Xiong; Li Kai; Li Dan-Ming; Wang Yi; Wang Yun-Fei; Feng Zhan-Zu

    2009-01-01

    The displacement damage dose methodology for analysing and modelling the performance of triple-junction InGaP_2/GaAs/Ge solar cells in an electron radiation environment is presented. Degradations at different electron energies are correlated with displacement damage dose (D_d). One particular electron radiation environment, relative to a geosynchronous earth orbit (GEO), is chosen to calculate the total D_d behind the different thicknesses coverglasses to predict the performance degradation at the end of the 15-year mission.

  5. [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.

  6. Physico-chemical studies of radiation effects in cells: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Powers, E.L.

    1987-03-01

    The career of Dr. E.L. Powers, a pioneer in the development of radiobiology, is reviewed. His initial research involved the effects of radiation and certain chemicals on Paramecium, associated ultrastructural studies on protozoan cells, responses of Rickettsia and bacteriophage to irradiation, and the development of techniques for studying bacterial spores. These efforts established the basic radiation biology of the spore and its importance in understanding the effects of free radicals, oxygen, and water. His recent research extended work on the dry spore to the very wet spore and to other selected chemical systems in aqueous suspension. 126 refs., 2 figs.

  7. Experimental and computer studies of the radiation effects in silicon solar cells

    Science.gov (United States)

    Leadon, R. E.; Naber, J. A.; Passenheim, B. C.

    1971-01-01

    A summary of selected experimental results obtained on lithium-diffused bulk silicon is presented. Particular emphasis is placed on the radiation-induced degradation and thermal annealing of minority carriers in bulk silicon because solar cell output is related to the minority carrier lifetime. The temperature dependence of the minority carrier lifetime indicates the density and energy levels of the recombination centers and provides clues to their identity. Electron spin resonance and infrared absorption techniques are used to investigate the introduction and anneal of three specific radiation induced defects, which are thought to contribute to the recombination process.

  8. Effect of radiation therapy on small-cell lung cancer is reduced by ubiquinone intake

    DEFF Research Database (Denmark)

    Lund, E L; Quistorff, B; Spang-Thomsen, M;

    1998-01-01

    The effect of oral ubiquinone (Q10) intake on the in vivo response of tumors to single dose radiotherapy was examined. The human small-cell lung cancer (SCLC) line CPH 054A, which is sensitive to relatively low doses of X-radiation, was grown as subcutaneous transplants in the flanks of nude nu...... radiation dose of 5 Gy, using a 300 kV therapeutic unit. The macroscopic growth pre- and posttreatment was analyzed according to a transformed Gompertz algorithm using the software program GROWTH. Treatment with Q10 or soy oil alone had no effect on tumor growth compared with untreated controls. Groups...

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

    Energy Technology Data Exchange (ETDEWEB)

    Brewen, J. G.; Preston, R. J.

    1977-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Brewen, J.G.; Preston, R.J.

    1978-01-01

    The induction of chromosome aberrations by low LET radiations was studied in peripheral lymphocytes and spermatogonial stem cells of the male marmoset. The data showed that there was not significant difference in the sensitivity of the lymphocytes whether they were irradiated in vitro or in vivo, but the frequency of heritable translocations recovered in the primary spermatocytes were considerably lower than that calculated to occur in the lymphocytes. The data are used to make estimates of human genetic risk from radiation based on limited interspecific comparisons.

  11. Abdominal CT during pregnancy: a phantom study on the effect of patient centring on conceptus radiation dose and image quality

    Energy Technology Data Exchange (ETDEWEB)

    Solomou, G.; Damilakis, J. [University of Crete, Faculty of Medicine, Department of Medical Physics, Heraklion, P.O. Box 2208, Crete (Greece); Papadakis, A.E. [University Hospital of Heraklion, Department of Medical Physics, Heraklion, P.O. Box 1352, Crete (Greece)

    2015-04-01

    To investigate the effect of patient centring on conceptus radiation dose and image quality in abdominal CT during pregnancy. Three anthropomorphic phantoms that represent a pregnant woman at the three trimesters of gestation were subjected to a routine abdominal CT. Examinations were performed with fixed mAs (mAs{sub f}) and with the automatic exposure control system (AEC) activated. The percent reduction between mAs{sub f} and modulated mAs (mAs{sub mod}) was calculated. Conceptus dose (D{sub c}) was measured using thermoluminescent dosimeters. To study the effect of misplacement of pregnant women on D{sub c}, each phantom was positioned at various locations relative to gantry isocentre. Image quality was evaluated on the basis of image noise, signal-to-noise ratio, and contrast-to-noise ratio. The maximum reduction between mAs{sub f} and mAs{sub mod} was 59.8 %, while the corresponding D{sub C} reduction was 59.3 %. D{sub C} was found to decrease by up to 25 % and 7.9 % for phantom locations below and above the isocentre, respectively. Image quality deteriorated when AEC was activated, and it was progressively improved from lower to higher than the isocentre locations. Centring errors do not result in an increase in D{sub c}. To maintain image quality, accurate centring is required. (orig.)

  12. The impact of pediatric-specific dose modulation curves on radiation dose and image quality in head computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Joana; Paulo, Graciano [Instituto Politecnico de Coimbra, ESTESC, DMIR, Coimbra (Portugal); Foley, Shane; Rainford, Louise [University College Dublin, School of Medicine and Medical Science, Health Science Centre, Dublin 4 (Ireland); McEntee, Mark F. [The University of Sydney, Faculty of Health Sciences, Cumberland Campus, Sydney (Australia)

    2015-11-15

    The volume of CT examinations has increased with resultant increases in collective dose values over the last decade. To analyze the impact of the tube current and voltage modulation for dose values and image quality of pediatric head CT examinations. Head CT examinations were performed on anthropomorphic phantoms and four pediatric age categories before and after the introduction of dedicated pediatric curves for tube voltage and current modulation. Local diagnostic reference levels were calculated. Visual grading characteristic image quality evaluation was performed by four pediatric neuroradiologists and image noise comparisons were performed. Pediatric-specific modulation curves demonstrated a 49% decrease in mean radiation dose for phantom examinations. The local diagnostic reference levels (CTDIvol) for clinical examinations decreased by 52%, 41%, 46% and 40% for newborn, 5-, 10- and 15-year-old patients, respectively. Visual grading characteristic image quality was maintained for the majority of age categorizations (area under the curve = 0.5) and image noise measurements did not change (P = 0.693). Pediatric-specific dose modulation curves resulted in an overall mean dose reduction of 45% with no significant differences in subjective or objective image quality findings. (orig.)

  13. Growth retardation of Paramecium and mouse cells by shielding them from background radiation.

    Science.gov (United States)

    Kawanishi, Masanobu; Okuyama, Katsuyuki; Shiraishi, Kazunori; Matsuda, Yatsuka; Taniguchi, Ryoichi; Shiomi, Nobuyuki; Yonezawa, Morio; Yagi, Takashi

    2012-01-01

    In the 1970s and 1980s, Planel et al. reported that the growth of paramecia was decreased by shielding them from background radiation. In the 1990s, Takizawa et al. found that mouse cells displayed a decreased growth rate under shielded conditions. The purpose of the present study was to confirm that growth is impaired in organisms that have been shielded from background radiation. Radioprotection was produced with a shielding chamber surrounded by a 15 cm thick iron wall and a 10 cm thick paraffin wall that reduced the γ ray and neutron levels in the chamber to 2% and 25% of the background levels, respectively. Although the growth of Paramecium tetraurelia was not impaired by short-term radioprotection (around 10 days), which disagreed with the findings of Planel et al., decreased growth was observed after long-term (40-50 days) radiation shielding. When mouse lymphoma L5178Y cells were incubated inside or outside of the shielding chamber for 7 days, the number of cells present on the 6th and 7th days under the shielding conditions was significantly lower than that present under the non-shielding conditions. These inhibitory effects on cell growth were abrogated by the addition of a ¹³⁷Cs γ-ray source disk to the chamber. Furthermore, no growth retardation was observed in XRCC4-deficient mouse M10 cells, which display impaired DNA double strand break repair.

  14. Determination of Invisible Environmental Pollution Due to Cell Phones EMF Radiation and projections for 2030

    Directory of Open Access Journals (Sweden)

    K Parandham Gowd

    2013-08-01

    Full Text Available In the last decades cell phones usage have altered the land scape of modern human beings in countless ways, in office, at home and on mobility. However, created the environmental electronic pollution due to electromagnetic fields. In spite of the recent studies indicating possible harmful impact of EMF pollution on several species, there is no long term data available on the environmental impacts of EMF pollution and how much power density is radiated in the environment due to cell phones. The aim of this research work is to experimentally measure the EMF radiated electronic pollution levels of cell phones in three different states such as on(sleep/idle mode, receive and transmit modes as an invisible environmental pollution. These measurements are carried out at the centre frequency of 1800 MHz and in the 300 MHz- 50 GHz frequency band. Another main aim is to carry out the projections of cell phones growth due to exponentially expanding mobile technology products, industrialization along with urbanization. Further to estimate the current (2013 EMF radiation pollution levels into environment and projections for 2030 due to cell phones.

  15. Asymptotic diffusion limit of cell temperature discretisation schemes for thermal radiation transport

    Energy Technology Data Exchange (ETDEWEB)

    Smedley-Stevenson, Richard P., E-mail: richard.smedley-stevenson@awe.co.uk [AWE PLC, Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom); Department of Earth Science and Engineering, Imperial College London, SW7 2AZ (United Kingdom); McClarren, Ryan G., E-mail: rmcclarren@ne.tamu.edu [Department of Nuclear Engineering, Texas A & M University, College Station, TX 77843-3133 (United States)

    2015-04-01

    This paper attempts to unify the asymptotic diffusion limit analysis of thermal radiation transport schemes, for a linear-discontinuous representation of the material temperature reconstructed from cell centred temperature unknowns, in a process known as ‘source tilting’. The asymptotic limits of both Monte Carlo (continuous in space) and deterministic approaches (based on linear-discontinuous finite elements) for solving the transport equation are investigated in slab geometry. The resulting discrete diffusion equations are found to have nonphysical terms that are proportional to any cell-edge discontinuity in the temperature representation. Based on this analysis it is possible to design accurate schemes for representing the material temperature, for coupling thermal radiation transport codes to a cell centred representation of internal energy favoured by ALE (arbitrary Lagrange–Eulerian) hydrodynamics schemes.

  16. Development of a quality assurance program for ionizing radiation secondary calibration laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Heaton, H.T. II; Taylor, A.R. Jr. [Center for Devices and Radiological Health, Rockville, MD (United States)

    1993-12-31

    For calibration laboratories, routine calibrations of instruments meeting stated accuracy goals are important. One method of achieving the accuracy goals is to establish and follow a quality assurance program designed to monitor all aspects of the calibration program and to provide the appropriate feedback mechanism if adjustments are needed. In the United States there are a number of organizations with laboratory accreditation programs. All existing accreditation programs require that the laboratory implement a quality assurance program with essentially the same elements in all of these programs. Collectively, these elements have been designated as a Measurement Quality Assurance (MQA) program. This paper will briefly discuss the interrelationship of the elements of an MQA program. Using the Center for Devices and Radiological Health (CDRH) X-ray Calibration Laboratory (XCL) as an example, it will focus on setting up a quality control program for the equipment in a Secondary Calibration Laboratory.

  17. Modulation of radiation-induced apoptosis and G{sub 2}/M block in murine T-lymphoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Palayoor, S.T.; Macklis, R.M.; Bump, E.A.; Coleman, C.N. [Harvard Medical School, Boston, MA (United States)

    1995-03-01

    Radiation-induced apoptosis in lymphocyte-derived cell lines is characterized by endonucleolytic cleavage of cellular DNA within hours after radiation exposure. We have studied this phenomenon qualitatively (DNA gel electrophoresis) and quantitatively (diphenylamine reagent assay) in murine EL4 T-lymphoma cells exposed to {sup 137}Cs {gamma} irradiation. Fragmentation was discernible within 18-24 h after exposure. It increased with time and dose and reached a plateau after 8 Gy of {gamma} radiation. We studied the effect of several pharmacological agents on the radiation-induced G{sub 2}/M block and DNA fragmentation. The agents which reduced the radiation-induced G{sub 2}/M-phase arrest (caffeine, theobromine, theophylline and 2-aminopurine) enhanced the degree of DNA fragmentation at 24 h. In contrast, the agents which sustained the radiation-induced G{sub 2}/M-phase arrest (TPA, DBcAMP, IBMX and 3-aminobenzamide) inhibited the DNA fragmentation at 24 h. These studies on EL4 lymphoma cells are consistent with the hypothesis that cells with radiation-induced genetic damage are eliminated by apoptosis subsequent to a G{sub 2}/M block. Furthermore, it may be possible to modulate the process of radiation-induced apoptosis in lymphoma cells with pharmacological agents that modify the radiation-induced G{sub 2}/M block, and to use this effect in the treatment of patients with malignant disease. 59 refs., 7 figs.

  18. Oral health-related quality of life of children and teens with sickle cell disease

    OpenAIRE

    2016-01-01

    ABSTRACT BACKGROUND: Children with sickle cell disease may have their quality of life affected by oral alterations. However, there is still little data on oral health-related quality of life in these children. The aim of this study was to investigate the influence of sickle cell disease, socioeconomic characteristics, and oral conditions on oral health-related quality of life of children and teens. METHOD: One hundred and six children and teens with sickle cell disease were compared to a ...

  19. Enhancement of radiation effect and increase of apoptosis in lung cancer cells by thio-glucose-bound gold nanoparticles at megavoltage radiation energies

    Energy Technology Data Exchange (ETDEWEB)

    Wang Cuihong; Li Xiaohong; Wang Yang; Liu Zhen [Qilu Hospital of Shandong University, Department of Radiation Therapy (China); Fu Lei [Shandong Cancer Hospital (China); Hu Likuan, E-mail: xqawc1120@126.com [Qilu Hospital of Shandong University, Department of Radiation Therapy (China)

    2013-05-15

    Gold nanoparticles (GNPs) (1-1,000 nm) modified by glucose have been considered to increase the toxicity of radiotherapy in human malignant cells. We report on the effect on lung-cancer cells, A549, of thio-glucose-bound gold nanoparticles (Glu-GNPs) with a size of 13 nm, combined with megavoltage (MV) X-ray. Viewed by transmission electron microscopy, Glu-GNPs were mainly distributed in the membrane-coated vesicles of A549 cells. The combination of Glu-GNPs with radiation resulted in a significant growth inhibition, compared with radiation alone (P < 0.05). Glu-GNPs enhanced radiation effect by increasing the ratio of A549 cells in the G2/M phase, and inducing more apoptosis. Furthermore, when combined with radiation, Glu-GNPs resulted in deregulation of Bcl-2 and upregulation of Bax and active caspase 3. Our results suggest that Glu-GNPs, as a new radiosensitizer, combined with radiation, can increase cytotoxicity on A549 cells not only by arresting the G2/M phase, but also by increasing apoptosis-probably via regulating the expression of Bcl-2 family of proteins and mitochondrial apoptotic pathway.

  20. Chemical chaperones reduce ionizing radiation-induced endoplasmic reticulum stress and cell death in IEC-6 cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Sang; Lee, Hae-June; Lee, Yoon-Jin [Division of Radiation Effects, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Jeong, Jae-Hoon [Division of Radiotherapy, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Kang, Seongman [Division of Life Sciences, Korea University, Seoul 136-701 (Korea, Republic of); Lim, Young-Bin, E-mail: yblim@kirams.re.kr [Division of Radiation Effects, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of)

    2014-07-25

    Highlights: • UPR activation precedes caspase activation in irradiated IEC-6 cells. • Chemical ER stress inducers radiosensitize IEC-6 cells. • siRNAs that targeted ER stress responses ameliorate IR-induced cell death. • Chemical chaperons prevent cell death in irradiated IEC-6 cells. - Abstract: Radiotherapy, which is one of the most effective approaches to the treatment of various cancers, plays an important role in malignant cell eradication in the pelvic area and abdomen. However, it also generates some degree of intestinal injury. Apoptosis in the intestinal epithelium is the primary pathological factor that initiates radiation-induced intestinal injury, but the mechanism by which ionizing radiation (IR) induces apoptosis in the intestinal epithelium is not clearly understood. Recently, IR has been shown to induce endoplasmic reticulum (ER) stress, thereby activating the unfolded protein response (UPR) signaling pathway in intestinal epithelial cells. However, the consequences of the IR-induced activation of the UPR signaling pathway on radiosensitivity in intestinal epithelial cells remain to be determined. In this study, we investigated the role of ER stress responses in IR-induced intestinal epithelial cell death. We show that chemical ER stress inducers, such as tunicamycin or thapsigargin, enhanced IR-induced caspase 3 activation and DNA fragmentation in intestinal epithelial cells. Knockdown of Xbp1 or Atf6 with small interfering RNA inhibited IR-induced caspase 3 activation. Treatment with chemical chaperones prevented ER stress and subsequent apoptosis in IR-exposed intestinal epithelial cells. Our results suggest a pro-apoptotic role of ER stress in IR-exposed intestinal epithelial cells. Furthermore, inhibiting ER stress may be an effective strategy to prevent IR-induced intestinal injury.

  1. Enhanced radiation response in radioresistant MCF-7 cells by targeting peroxiredoxin II

    Directory of Open Access Journals (Sweden)

    Diaz AJG

    2013-10-01

    Full Text Available Anthony Joseph Gomez Diaz,1 Daniel Tamae,2 Yun Yen,3 JianJian Li,4 Tieli Wang1 1Department of Chemistry and Biochemistry, California State University at Dominguez Hills, Carson, CA, 2Center of Excellence in Environmental Toxicology, Department of Pharmacology, University of Pennsylvania, Philadelphia, PA, 3Department of Clinical and Molecular Pharmacology, Beckman Research Institute of City of Hope National Medical Center, Duarte, CA, 4Department of Radiation Oncology, University of California Davis, Sacramento, CA, USA Abstract: In our previous study, we identified that a protein target, peroxiredoxin II (PrxII, is overexpressed in radioresistant MCF+FIR3 breast-cancer cells and found that its expression and function is associated with breast-cancer radiation sensitivity or resistance. Small interference RNA (siRNA targeting PrxII gene expression was able to sensitize MCF+FIR3 radioresistant breast-cancer cells to ionizing radiation. The major focus of this work was to investigate how the radiation response of MCF+FIR3 radioresistant cells was affected by the siRNA that inhibits PrxII gene expression. Our results, presented here, show that silencing PrxII gene expression increased cellular toxicit