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Sample records for 0-50 rad range

  1. Ceric and ferrous dosimeters show precision for 50-5000 rad range

    Science.gov (United States)

    Frigerio, N. A.; Henry, V. D.

    1968-01-01

    Ammonium thiocyanate, added to the usual ferrous sulfate dosimeter solution, yielded a very stable, precise and temperature-independent system eight times as sensitive as the classical Fricke system in the 50 to 5000 rad range. The ceric dosimeters, promising for use in mixed radiation fields, respond nearly independently of LET.

  2. 28 CFR 0.50 - General functions.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false General functions. 0.50 Section 0.50 Judicial Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE Civil Rights... thereon, and initiating action appropriate thereto. (d) Coordination within the Department of Justice...

  3. Consequences of embedding Ti4+ 3d0 centers in Pr0.50Ca0.50MnO3 : Phase competition in Pr0.50Ca0.50Mn1-xTixO3

    Science.gov (United States)

    García-Muñoz, J. L.; Frontera, C.; Beran, P.; Bellido, N.; Hernández-Velasco, J.; Ritter, C.

    2010-01-01

    We have studied the structural and magnetic phase coexistence/competition derived from the partial random substitution of 3d0 nonmagnetic Ti4+ ions for Mn in Pr0.50Ca0.50MnO3 , and their evolution with the doping level in Pr0.50Ca0.50Mn1-xTixO3 ( x=0 , 0.01, 0.03, and 0.05) manganites. Combining high-resolution synchrotron, neutron powder-diffraction, and muon techniques we describe with great detail the coexistence of two different structural phases below ≈240K (charge-order transition temperature, TCO ) with different cell distortion, antiferromagnetic order, and strain characteristics. The evolution of all these features with Ti substitution level is thoroughly described. Ti4+ (3d0) ions do not favor the stabilization of ferromagnetic/metallic (FM/M) islands/regions in the antiferromagnetic/insulating (AFM/I) orbital-ordered matrix. The absence of short- and long-range ferromagnetism in zero field has been confirmed by different techniques. The proportion of microdomains exhibiting pseudo-(CE)-type magnetic order (CE: charge exchange) increases with the Ti content at expenses of the CE-type regions. Differences in the stability of competing phases against magnetic field have been found by neutron-diffraction measurements under application of external fields. The phase coexistence exhibits strong anisotropic strain effects that have been thoroughly analyzed as a function of the Ti content x . We have found very remarkable changes in the strain characteristics of the AFM segregated phases on going from 1% to 5% Ti. Large anisotropic strains develop mainly in the minority phase of the material. The magnitude of strains is discussed in comparison with anisotropic strain values recently determined in the case of substitutions (such as Co) that favor FM/M domains.

  4. Dielectric and Pyroelectric Properties of (Pb0.50Sr0.50)TiO3 Ceramics

    Institute of Scientific and Technical Information of China (English)

    JIANG Yan-Ping; TANG Xin-Gui; LIU Qiu-Xiang; ZHOU Yi-Chun; CHANWONG Lai-Wa

    2008-01-01

    @@ Lead strontium titanate (Pb0.50Sr0.50)TiO3 (PST) ceramics are prepared by the traditional ceramic processing. The dielectric constants and dielectric loss have been investigated in a temperature range from 25℃ to 300℃. The maximum dielectric constants for unpoled and poled samples are 9924 and 9683, respectively. The temperatures of phase transition for unpoled and poled samples are observed at 153℃ and 157℃, respectively. The phase-transition temperatures for unpoled and poled samples are not equal, which results from the polarization state of the domains. The remnant polarization and the coercive electric field are 18 μC/cm2 and 6 k V/cm, respectively, from polarization-electric field (P- E) hysteresis loop. The temperature dependence of pyroelectric coefficients of the PST ceramics is measured by a dynamic technique. The dielectric constant and loss tan 5 of the poled PST ceramics are 813 and 0.010, respectively. The pyroelectric coefficients and figure of merit are 294 μC/cm2 K and 13.6 × 10-6 Pa-0.5, respectively, at room temperature 25℃ and frequency 100 Hz.

  5. Demystifying the RAD fad.

    Science.gov (United States)

    Puritz, Jonathan B; Matz, Mikhail V; Toonen, Robert J; Weber, Jesse N; Bolnick, Daniel I; Bird, Christopher E

    2014-12-01

    We are writing in response to the population and phylogenomics meeting review by Andrews & Luikart (2014) entitled 'Recent novel approaches for population genomics data analysis'. Restriction-site-associated DNA (RAD) sequencing has become a powerful and useful approach in molecular ecology, with several different published methods now available to molecular ecologists, none of which can be considered the best option in all situations. A&L report that the original RAD protocol of Miller et al. (2007) and Baird et al. (2008) is superior to all other RAD variants because putative PCR duplicates can be identified (see Baxter et al. 2011), thereby reducing the impact of PCR artefacts on allele frequency estimates (Andrews & Luikart 2014). In response, we (i) challenge the assertion that the original RAD protocol minimizes the impact of PCR artefacts relative to that of other RAD protocols, (ii) present additional biases in RADseq that are at least as important as PCR artefacts in selecting a RAD protocol and (iii) highlight the strengths and weaknesses of four different approaches to RADseq which are a representative sample of all RAD variants: the original RAD protocol (mbRAD, Miller et al. 2007; Baird et al. 2008), double digest RAD (ddRAD, Peterson et al. 2012), ezRAD (Toonen et al. 2013) and 2bRAD (Wang et al. 2012). With an understanding of the strengths and weaknesses of different RAD protocols, researchers can make a more informed decision when selecting a RAD protocol.

  6. Influence of strain on an epitaxial ferroelectric (Ba0.50Sr0.50)TiO3 nanodot under different electrical boundary conditions

    Science.gov (United States)

    Bin-Omran, S.

    2017-02-01

    A first-principles-derived effective Hamiltonian approach is used to reveal the temperature-versus-misfit strain phase diagram of an epitaxial (Ba0.50Sr0.50)TiO3 dot under different electrical boundary conditions. The results indicate that the electrical polarization and toroidal moment are highly sensitive to the applied strain and/or electrical boundary conditions, resulting in a wide variety of phases that are not found in a free-standing BST dot and in bulk. The calculations indicate that within a narrow range of surface charge screening an intermediate phase in which the polarization and toroidal moment coexist. The dependences of the electrical polarization, toroidal moment and dielectric permittivity on the misfit strain and electrical boundary conditions at room temperature are also investigated and compared with the available theoretical predictions and experimental measurements.

  7. RadLex

    Data.gov (United States)

    U.S. Department of Health & Human Services — RadLex is a controlled terminology for radiology and serves as a single unified source of radiology terms for radiology practice, education, and research. RadLex is...

  8. RadWorks Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For the first two years of the project (FY12-13), the RadWorks project has consisted of two top-level elements. The first element involved the prototype and...

  9. Reach Address Database (RAD)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Reach Address Database (RAD) stores the reach address of each Water Program feature that has been linked to the underlying surface water features (streams,...

  10. From first-order magneto-elastic to magneto-structural transition in (Mn,Fe)1.95P0.50Si0.50 compounds

    NARCIS (Netherlands)

    Dung, N. H.; Zhang, L.; Ou, Z. Q.; Brück, E.

    2011-01-01

    We report on structural, magnetic, and magnetocaloric properties of MnxFe1.95−xP0.50Si0.50 (x ≥ 1.10) compounds. With increasing the Mn:Fe ratio, a first-order magneto-elastic transition gradually changes into a first-order magneto-structural transition via a second-order magnetic transition. The st

  11. Role of Pr cations and the low temperature transition in Pr{sub 0.50}Sr{sub 0.50}CoO{sub 3}: A comparison to Pr{sub 0.50}Ca{sub 0.50}CoO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Padilla-Pantoja, J., E-mail: jpadilla@icmab.es [Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus univ. de Bellaterra, E-08193 Bellaterra (Spain); Barón-González, A.J. [Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus univ. de Bellaterra, E-08193 Bellaterra (Spain); Grupo Física de Materiales, Universidad Pedagógica y Tecnológica de Colombia, Tunja (Colombia); Bozzo, B. [Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus univ. de Bellaterra, E-08193 Bellaterra (Spain); Blasco, J. [Instituto de Ciencia de Materiales de Aragón, CSIC-Univ. de Zaragoza, 50009 Zaragoza (Spain); Ritter, C. [Institute Laue Langevin, BP 156, 38042 Grenoble Cedex 9 (France); Herrero-Martín, J. [ALBA Synchrotron Light Source, 08290 Cerdanyola del Vallès, Barcelona (Spain); García-Muñoz, J.L. [Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus univ. de Bellaterra, E-08193 Bellaterra (Spain)

    2014-12-15

    The low temperature properties of Pr{sub 0.50}Sr{sub 0.50}CoO{sub 3} are studied in comparison to Pr{sub 0.50}Ca{sub 0.50}CoO{sub 3}, which is known to exhibit a Pr{sup 3+}/Pr{sup 4+} valence shift below T{sub MI}∼80 K. The evolution of the Pr–O network strongly differs in the Sr and Ca compounds, but both have in common a prominent and sudden contraction of some Pr–O bonds. The structural phase transition that accompanies the so-called magnetocrystalline anisotropy transition at T{sub S}∼120 K in Pr{sub 0.50}Sr{sub 0.50}CoO{sub 3} brings about a notable contraction of some Pr–O{sub 2} bonds. The observations give support to the active participation of Pr-4f electrons at the intriguing magnetostructural transition (T{sub S}) in Pr{sub 0.50}Sr{sub 0.50}CoO{sub 3}. In addition, we have confirmed that (in absence of praseodymium) the magnetostructural transition is suppressed in (Nd{sub 2/3}La{sub 1/3}){sub 0.50}Sr{sub 0.50}CoO{sub 3}, a perovskite with the same average cationic size at the A-site than Pr{sub 0.50}Sr{sub 0.50}CoO{sub 3}.

  12. Meiotic functions of RAD18

    NARCIS (Netherlands)

    A. Inagaki (Akiko); E. Sleddens-Linkels (Esther); E. Wassenaar (Evelyne); M.P. Ooms (Marja); W.A. van Cappellen (Gert); J.H.J. Hoeijmakers (Jan); J. Seibler (Jost); T.F. Vogt (Thomas F.); M.K. Shin (Myung K.); J.A. Grootegoed (Anton); W.M. Baarends (Willy)

    2011-01-01

    textabstractRAD18 is an ubiquitin ligase that is involved in replication damage bypass and DNA double-strand break (DSB) repair processes in mitotic cells. Here, we investigated the testicular phenotype of Rad18-knockdown mice to determine the function of RAD18 in meiosis, and in particular, in the

  13. Laser-Assisted Synthesis of Mn0.50Zn0.50Fe2O4 Nanomaterial: Characterization and In Vitro Inhibition Activity towards Bacillus subtilis Biofilm

    Directory of Open Access Journals (Sweden)

    Shaukat Ali Shahid

    2015-01-01

    Full Text Available There is growing interest in the development of novel nanomaterials with potential antimicrobial activity and lesser toxicity. In the current research work, Mn0.5Zn0.5Fe2O4 nanoparticles were synthesized via a novel coprecipitation cum laser ablation technique yielding fine spinal structured material. The synthesized nanomaterial was structurally characterized by X-ray diffraction technique which confirmed the formation and the crystalline nature of Mn0.50Zn0.50Fe2O4 nanomaterial. The crystallite size determined by Debye-Scherrer’s formula was found to be ~12 nm. The formation of nanoparticles was evidenced by scanning electron microscopy. Energy dispersive X-ray analysis (EDXA was performed for elemental analysis. The synthesized nanomaterial was interestingly found to be an effective antimicrobial agent and inhibited the growth of Bacillus subtilis biofilm formation. The 5 µg of Mn0.5Zn0.5Fe2O4 nanomaterial dissolved in 1 mL of DMSO showed excellent biofilm inhibitory activity 91.23% ± 1.87 against Bacillus subtilis.

  14. Homologous Pairing Activities of Two Rice RAD51 Proteins, RAD51A1 and RAD51A2

    Science.gov (United States)

    Ikawa, Shukuko; Mimida, Naozumi; Shimizu, Takeshi; Toki, Seiichi; Ichikawa, Hiroaki; Shibata, Takehiko; Kurumizaka, Hitoshi

    2013-01-01

    In higher eukaryotes, RAD51 functions as an essential protein in homologous recombination and recombinational repair of DNA double strand breaks. During these processes, RAD51 catalyzes homologous pairing between single-stranded DNA and double-stranded DNA. Japonica cultivars of rice (Oryza sativa) encode two RAD51 proteins, RAD51A1 and RAD51A2, whereas only one RAD51 exists in yeast and mammals. However, the functional differences between RAD51A1 and RAD51A2 have not been elucidated, because their biochemical properties have not been characterized. In the present study, we purified RAD51A1 and RAD51A2, and found that RAD51A2 robustly promotes homologous pairing in vitro. RAD51A1 also possesses homologous-pairing activity, but it is only about 10% of the RAD51A2 activity. Both RAD51A1 and RAD51A2 bind to ssDNA and dsDNA, and their DNA binding strictly requires ATP, which modulates the polymer formation activities of RAD51A1 and RAD51A2. These findings suggest that although both RAD51A1 and RAD51A2 have the potential to catalyze homologous pairing, RAD51A2 may be the major recombinase in rice. PMID:24124491

  15. Extreme Temperature, Rad-Hard Power Management ASIC Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ridgetop Group will design a rad-hard Application Specific Integrated Circuit (ASIC) for spacecraft power management that is functional over a temperature range of...

  16. Rad52 and Rad59 exhibit both overlapping and distinct functions

    DEFF Research Database (Denmark)

    Feng, Qi; Düring, Louis; Antúnez de Mayolo, Adriana

    2007-01-01

    annealing of complementary single-stranded DNA in vitro, but only Rad52 interacts with replication protein A and the Rad51 recombinase. We have studied the functional overlap between Rad52 and Rad59 in living cells using chimeras of the two proteins and site-directed mutagenesis. We find that Rad52 and Rad...

  17. Regulation of Rad51 promoter

    Science.gov (United States)

    Hine, Christopher M; Li, Hongjie; Xie, Li; Mao, Zhiyong; Seluanov, Andrei; Gorbunova, Vera

    2014-01-01

    The DNA double-strand break repair and homologous recombination protein Rad51 is overexpressed in the majority of human cancers. This correlates with therapy resistance and decreased patient survival. We previously showed that constructs containing Rad51 promoter fused to a reporter gene are, on average, 850-fold more active in cancer cells than in normal cells. It is not well understood what factors and sequences regulate the Rad51 promoter and cause its high activity in cancerous cells. Here we characterized regulatory regions and examined genetic requirements for oncogenic stimulation of the Rad51 promoter. We identified specific regions responsible for up- and downregulation of the Rad51 promoter in cancerous cells. Furthermore, we show that Rad51 expression is positively regulated by EGR1 transcription factor. We then modeled the malignant transformation process by expressing a set of oncoproteins in normal human fibroblasts. Expression of different combinations of SV40 large T antigen, oncogenic Ras and SV40 small T antigen resulted in step-wise increase in Rad51 promoter activity, with all the 3 oncoproteins together leading to a 47-fold increase in expression. Cumulatively, these results suggest that Rad51 promoter is regulated by multiple factors, and that its expression is gradually activated as cells progress toward malignancy. PMID:24781030

  18. Meiotic functions of RAD18.

    Science.gov (United States)

    Inagaki, Akiko; Sleddens-Linkels, Esther; Wassenaar, Evelyne; Ooms, Marja; van Cappellen, Wiggert A; Hoeijmakers, Jan H J; Seibler, Jost; Vogt, Thomas F; Shin, Myung K; Grootegoed, J Anton; Baarends, Willy M

    2011-08-15

    RAD18 is an ubiquitin ligase that is involved in replication damage bypass and DNA double-strand break (DSB) repair processes in mitotic cells. Here, we investigated the testicular phenotype of Rad18-knockdown mice to determine the function of RAD18 in meiosis, and in particular, in the repair of meiotic DSBs induced by the meiosis-specific topoisomerase-like enzyme SPO11. We found that RAD18 is recruited to a specific subfraction of persistent meiotic DSBs. In addition, RAD18 is recruited to the chromatin of the XY chromosome pair, which forms the transcriptionally silent XY body. At the XY body, RAD18 mediates the chromatin association of its interaction partners, the ubiquitin-conjugating enzymes HR6A and HR6B. Moreover, RAD18 was found to regulate the level of dimethylation of histone H3 at Lys4 and maintain meiotic sex chromosome inactivation, in a manner similar to that previously observed for HR6B. Finally, we show that RAD18 and HR6B have a role in the efficient repair of a small subset of meiotic DSBs.

  19. Utilization of Rad51C promoter for transcriptional targeting of cancer cells

    Science.gov (United States)

    Li, Zhen; Jiang, Ying; Tian, Xiao; Seluanov, Andrei; Gorbunova, Vera; Mao, Zhiyong

    2014-01-01

    Cancer therapy that specifically targets malignant cells with minimal or no toxicity to normal tissue has been a long-standing goal of cancer research. Rad51 expression is elevated in a wide range of cancers and Rad51 promoter has been used to transcriptionally target tumor cells, however, a large size of Rad51 promoter limits its application for gene therapy. To identify novel tumor-specific promoters, we examined expression levels of Rad51 paralogs, Rad51B, Rad51C, and Rad51D as well as Rad52 in a panel of normal and tumor cell lines. We found that Rad51C is significantly overexpressed in cancer cells. The expression was up-regulated by approximately 6-fold at the mRNA level and 9-fold at the protein level. Interestingly, the 2064 bp long Rad51C promoter fragment was approximately 300-fold higher in cancer cells than in normal cells. A construct containing Rad51C promoter driving diphtheria toxin A efficiently killed several types of cancer cells with very mild effect to normal cells. These results underscore the potential of targeting the homologous recombination pathway in cancer cells and provide a proof of principle that the Rad51C promoter fragment can be used to transcriptionally target cancer cells. PMID:24742710

  20. Rad Pole Cam Development

    Energy Technology Data Exchange (ETDEWEB)

    Heckendorn, F. M.; Odell, D. M. C; Harpring, L. J.; Peterson, K. D.

    2005-10-05

    The RadPoleCam was developed to provide Department Of Energy (DOE) first responders the capability to assess the radiological and visual condition of remote or inaccessible locations. Real time gamma isotopic identification is provided to the first responder in the form of audio feedback (i.e. spoken through head phones) from a gamma detector mounted on a collapsible pole that can extend from 1 to 9 meters (6 to 29 feet). Simultaneously, selectable direct and side looking visual images are provided from the 5cm (2in) diameter, waterproof probe tip. The lightweight, self contained, ruggedized, system will provide a rapidly deployable field system for visual and radiological search and assessment of confined spaces and extended reach locations.

  1. RadFlexPro Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Our proposed multilayered, flexible, graded Z radiation shielding, RadFlexPro, provides radiation protection for astronauts in EVA for NASA's future space missions....

  2. Thickness dependent structural, magnetic and magneto-transport properties of epitaxial Nd{sub 0.50}Sr{sub 0.50}MnO{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Pawan, E-mail: p.kumar@krmangalam.edu.in [School of Basic and Applied Sciences, K. R. Mangalam University, Sohna Road, Gurgaon, Haryana 122103 (India); Singh, Hari Krishna, E-mail: hks65@nplindia.org [CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012 (India)

    2016-05-06

    We report the thickness-dependent structural, magnetic and magneto-transport properties in epitaxial Nd{sub 0.50}Sr{sub 0.50}MnO{sub 3} thin films (10 to 300nm) prepared by DC magnetron sputtering technique on single crystalline (001) oriented substrate LaAlO{sub 3}. X-ray diffraction pattern reveals the epitaxial growth of all the films and the out-of-plane lattice parameter of films were found to increase with thickness. As thickness of the film increases the paramagnetic insulator (PMI) to ferromagnetic metal (FMM) transition temperature (T{sub C}), charge ordered transition temperature (T{sub CO}) and magnetic moment were found to increase with a strong bifurcation in ZFC-FC magnetization. The asymmetry in the coercivity seen in field dependent magnetization loops (M-H loops) suggests the presence of exchange bias (EB) effect. While temperature dependent resistivity of films show the semiconducting nature for thickness 10-200nm in temperature range from 5-300K, the film of thickness 300nm shows the insulator to metal transition with transition temperature (T{sub IM}) at 175K. Temperature dependent low field magnetoresistance (LFMR) measured at 4kOe found to decrease with thickness and for high field magnetoresistance (HFMR) at 40kOe and 60kOe also show similar dependence and a crossover at intermediate temperature range in the magnitude of MR between 10nm and 200nm films at constant field. Colossal increase in magnetoresistance observed for 10nm film at low temperature.

  3. Long Term RadNet Quality Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — This RadNet Quality Data Asset includes all data since initiation and when ERAMS was expanded to become RadNet, name changed to reflect new mission. This includes...

  4. RadNet Databases and Reports

    Science.gov (United States)

    EPA’s RadNet data are available for viewing in a searchable database or as PDF reports. Historical and current RadNet monitoring data are used to estimate long-term trends in environmental radiation levels.

  5. RadTown USA: Basic Information

    Science.gov (United States)

    ... Burbs Countryside Waterfront Downtown Did you know? RadTown Games Educational Materials Bring RadTown into the classroom with lesson ... click! Area Navigation Home Burbs Countryside Waterfront Downtown Educational Materials RadTown A to Z Games Link to Us Glossary Subscribe to Listserv News ...

  6. Inferring phylogenies from RAD sequence data.

    Directory of Open Access Journals (Sweden)

    Benjamin E R Rubin

    Full Text Available Reduced-representation genome sequencing represents a new source of data for systematics, and its potential utility in interspecific phylogeny reconstruction has not yet been explored. One approach that seems especially promising is the use of inexpensive short-read technologies (e.g., Illumina, SOLiD to sequence restriction-site associated DNA (RAD--the regions of the genome that flank the recognition sites of restriction enzymes. In this study, we simulated the collection of RAD sequences from sequenced genomes of different taxa (Drosophila, mammals, and yeasts and developed a proof-of-concept workflow to test whether informative data could be extracted and used to accurately reconstruct "known" phylogenies of species within each group. The workflow consists of three basic steps: first, sequences are clustered by similarity to estimate orthology; second, clusters are filtered by taxonomic coverage; and third, they are aligned and concatenated for "total evidence" phylogenetic analysis. We evaluated the performance of clustering and filtering parameters by comparing the resulting topologies with well-supported reference trees and we were able to identify conditions under which the reference tree was inferred with high support. For Drosophila, whole genome alignments allowed us to directly evaluate which parameters most consistently recovered orthologous sequences. For the parameter ranges explored, we recovered the best results at the low ends of sequence similarity and taxonomic representation of loci; these generated the largest supermatrices with the highest proportion of missing data. Applications of the method to mammals and yeasts were less successful, which we suggest may be due partly to their much deeper evolutionary divergence times compared to Drosophila (crown ages of approximately 100 and 300 versus 60 Mya, respectively. RAD sequences thus appear to hold promise for reconstructing phylogenetic relationships in younger clades in

  7. Inferring phylogenies from RAD sequence data.

    Science.gov (United States)

    Rubin, Benjamin E R; Ree, Richard H; Moreau, Corrie S

    2012-01-01

    Reduced-representation genome sequencing represents a new source of data for systematics, and its potential utility in interspecific phylogeny reconstruction has not yet been explored. One approach that seems especially promising is the use of inexpensive short-read technologies (e.g., Illumina, SOLiD) to sequence restriction-site associated DNA (RAD)--the regions of the genome that flank the recognition sites of restriction enzymes. In this study, we simulated the collection of RAD sequences from sequenced genomes of different taxa (Drosophila, mammals, and yeasts) and developed a proof-of-concept workflow to test whether informative data could be extracted and used to accurately reconstruct "known" phylogenies of species within each group. The workflow consists of three basic steps: first, sequences are clustered by similarity to estimate orthology; second, clusters are filtered by taxonomic coverage; and third, they are aligned and concatenated for "total evidence" phylogenetic analysis. We evaluated the performance of clustering and filtering parameters by comparing the resulting topologies with well-supported reference trees and we were able to identify conditions under which the reference tree was inferred with high support. For Drosophila, whole genome alignments allowed us to directly evaluate which parameters most consistently recovered orthologous sequences. For the parameter ranges explored, we recovered the best results at the low ends of sequence similarity and taxonomic representation of loci; these generated the largest supermatrices with the highest proportion of missing data. Applications of the method to mammals and yeasts were less successful, which we suggest may be due partly to their much deeper evolutionary divergence times compared to Drosophila (crown ages of approximately 100 and 300 versus 60 Mya, respectively). RAD sequences thus appear to hold promise for reconstructing phylogenetic relationships in younger clades in which sufficient

  8. Rare adipose disorders (RADs) masquerading as obesity

    Institute of Scientific and Technical Information of China (English)

    Karen L HERBST

    2012-01-01

    Rare adipose disorders (RADs) including multiple symmetric lipomatosis (MSL),lipedema and Dercum's disease (DD) may be misdiagnosed as obesity.Lifestyle changes,such as reduced caloric intake and increased physical activity are standard care for obesity.Although lifestyle changes and bariatric surgery work effectively for the obesity component of RADs,these treatments do not routinely reduce the abnormal subcutaneous adipose tissue (SAT) of RADs.RAD SAT likely results from the growth of a brown stem cell population with secondary lymphatic dysfunction in MSL,or by primary vascular and lymphatic dysfunction in lipedema and DD.People with RADs do not lose SAT from caloric limitation and increased energy expenditure alone.In order to improve recognition of RADs apart from obesity,the diagnostic criteria,histology and pathophysiology of RADs are presented and contrasted to familial partial lipodystrophies,acquired partial lipodystrophies and obesity with which they may be confused.Treatment recommendations focus on evidencebased data and include lymphatic decongestive therapy,medications and supplements that support loss of RAD SAT.Associated RAD conditions including depression,anxiety and pain will improve as healthcare providers learn to identify and adopt alternative treatment regimens for the abnormal SAT component of RADs.Effective dietary and exercise regimens are needed in RAD populations to improve quality of life and construct advanced treatment regimens for future generations.

  9. Purification of Rad1 protein from Saccharomyces cerevisiae and further characterization of the Rad1/Rad10 endonuclease complex.

    Science.gov (United States)

    Tomkinson, A E; Bardwell, A J; Tappe, N; Ramos, W; Friedberg, E C

    1994-05-03

    The yeast recombination and repair proteins Rad1 and Rad10 associate with a 1:1 stoichiometry to form a stable complex with a relative molecular mass of 190 kDa. This complex, which has previously been shown to degrade single-stranded DNA endonucleolytically, also cleaves supercoiled duplex DNA molecules. In this reaction, supercoiled (form I) molecules are rapidly converted to nicked, relaxed (form II) molecules, presumably as a result of nicking at transient single-stranded regions in the supercoiled DNA. At high enzyme concentrations, there is a slow conversion of the form II molecules to linear (form III) molecules. The Rad1/Rad10 endonuclease does not preferentially cleave UV-irradiated DNA and has no detectable exonuclease activity. The nuclease activity of the Rad1/Rad10 complex is consistent with the predicted roles of the RAD1 and RAD10 genes of Saccharomyces cerevisiae in both the incision events of nucleotide excision repair and the removal of nonhomologous 3' single strands during intrachromosomal recombination between repeated sequences. In these pathways, the specificity and reactivity of the Rad1/Rad10 endonuclease will probably be modulated by further protein-protein interactions.

  10. Preparation structure and dielectric behaviour of the system Sr1-LaTi1-FeO3( ≤ 0.50)

    Indian Academy of Sciences (India)

    Om Parkash; Devendra Kumar; C C Christopher

    2003-10-01

    Formation of solid solution has been explored in the valence compensated perovskite oxide system Sr1-LaTi1-FeO3 ( ≤ 0.50). XRD studies indicate the formation of solid solution for the whole range investigated. All the compositions synthesised have cubic structure similar to undoped SrTiO3. Study of dielectric behaviour of these materials show that orientational polarisation and space charge polarisation contribute significantly to it.

  11. Rad51 Paralogs Remodel Pre-synaptic Rad51 Filaments to Stimulate Homologous Recombination

    OpenAIRE

    Taylor, MRG; Špírek, M; Chaurasiya, KR; Ward, JD; Carzaniga, R.; Yu, X; Egelman, EH; Collinson, LM; Rueda, D.; Krejci, L; Boulton, SJ

    2015-01-01

    Summary Repair of DNA double strand breaks by homologous recombination (HR) is initiated by Rad51 filament nucleation on single-stranded DNA (ssDNA), which catalyzes strand exchange with homologous duplex DNA. BRCA2 and the Rad51 paralogs are tumor suppressors and critical mediators of Rad51. To gain insight into Rad51 paralog function, we investigated a heterodimeric Rad51 paralog complex, RFS-1/RIP-1, and uncovered the molecular basis by which Rad51 paralogs promote HR. Unlike BRCA2, which ...

  12. Roles of XRCC2, RAD51B and RAD51D in RAD51-independent SSA recombination.

    Directory of Open Access Journals (Sweden)

    Heïdi Serra

    2013-11-01

    Full Text Available The repair of DNA double-strand breaks by recombination is key to the maintenance of genome integrity in all living organisms. Recombination can however generate mutations and chromosomal rearrangements, making the regulation and the choice of specific pathways of great importance. In addition to end-joining through non-homologous recombination pathways, DNA breaks are repaired by two homology-dependent pathways that can be distinguished by their dependence or not on strand invasion catalysed by the RAD51 recombinase. Working with the plant Arabidopsis thaliana, we present here an unexpected role in recombination for the Arabidopsis RAD51 paralogues XRCC2, RAD51B and RAD51D in the RAD51-independent single-strand annealing pathway. The roles of these proteins are seen in spontaneous and in DSB-induced recombination at a tandem direct repeat recombination tester locus, both of which are unaffected by the absence of RAD51. Individual roles of these proteins are suggested by the strikingly different severities of the phenotypes of the individual mutants, with the xrcc2 mutant being the most affected, and this is confirmed by epistasis analyses using multiple knockouts. Notwithstanding their clearly established importance for RAD51-dependent homologous recombination, XRCC2, RAD51B and RAD51D thus also participate in Single-Strand Annealing recombination.

  13. Role of crystalline precipitates on the mechanical properties of (Cu{sub 0.50}Zr{sub 0.50}){sub 100-x}Al{sub x} (x = 4, 5, 7) bulk metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Castellero, A., E-mail: alberto.castellero@unito.it [Dipartimento di Chimica IFM and NIS, Universita di Torino, Via P. Giuria 9, I-10125 Torino (Italy); Baser, T.A. [Dipartimento di Chimica IFM and NIS, Universita di Torino, Via P. Giuria 9, I-10125 Torino (Italy); EMPA - Swiss Federal Laboratories for Materials Testing and Research, Duebendorf (Switzerland); Das, J. [IFW Dresden, Institut fuer Komplexe Materialien, Helmholtzstr. 20, D-01069 Dresden (Germany); Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur 721 302, West Bengal (India); Matteis, P. [DISMIC - Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Torino (Italy); Eckert, J. [IFW Dresden, Institut fuer Komplexe Materialien, Helmholtzstr. 20, D-01069 Dresden (Germany); TU Dresden, Institut fuer Werkstoffwissenschaft, D-01062 Dresden (Germany); Battezzati, L.; Baricco, M. [Dipartimento di Chimica IFM and NIS, Universita di Torino, Via P. Giuria 9, I-10125 Torino (Italy)

    2011-06-15

    Research highlights: > The glass formation reproducibility of (Cu{sub 0.50}Zr{sub 0.50}){sub 100-x}Al{sub x} (x = 4,5,7) was investigated. > X-ray amorphous Cu{sub 48}Zr{sub 48}Al{sub 4} samples contain up to 20% of B2-CuZr crystals. > Fracture strain scales directly with the amount of the B2-CuZr crystalline phase. > Spread in literature values of fracture strain for these alloys is likely due to the presence of undetected crystals. > Mechanical properties reliability can be improved by sample surface finishing. - Abstract: The mechanical behaviour upon compression of (Cu{sub 0.50}Zr{sub 0.50}){sub 100-x}Al{sub x} (x = 4, 5, 7) rods with 2 and 3 mm diameter was systematically studied and compared with the literature data. Fully amorphous bulk metallic glasses (x = 5, 7) show little permanent deformation and reproducible yield stress values. The remarkable fracture strain, observed for some apparently X-ray diffraction amorphous samples (x = 4), was found to be due to significant amounts (at least 20%) of the B2-CuZr crystalline phase. The effect of possible flaws on the external surface of the rods was evaluated by mechanical testing of either as cast and machined samples.

  14. Physical mapping and cloning of RAD56

    DEFF Research Database (Denmark)

    Mathiasen, David P; Gallina, Irene; Germann, Susanne Manuela

    2013-01-01

    Here we report the physical mapping of the rad56-1 mutation to the NAT3 gene, which encodes the catalytic subunit of the NatB N-terminal acetyltransferase in Saccharomyces cerevisiae. Mutation of RAD56 causes sensitivity to X-rays, methyl methanesulfonate, zeocin, camptothecin and hydroxyurea, bu...

  15. Physical mapping and cloning of RAD56

    DEFF Research Database (Denmark)

    Mathiasen, David P; Gallina, Irene; Germann, Susanne Manuela

    2013-01-01

    Here we report the physical mapping of the rad56-1 mutation to the NAT3 gene, which encodes the catalytic subunit of the NatB N-terminal acetyltransferase in Saccharomyces cerevisiae. Mutation of RAD56 causes sensitivity to X-rays, methyl methanesulfonate, zeocin, camptothecin and hydroxyurea, bu...

  16. RAD51AP2, a novel vertebrate- and meiotic-specific protein, sharesa conserved RAD51-interacting C-terminal domain with RAD51AP1/PIR51

    Energy Technology Data Exchange (ETDEWEB)

    Kovalenko, Oleg V.; Wiese, Claudia; Schild, David

    2006-07-25

    Many interacting proteins regulate and/or assist the activities of RAD51, a recombinase which plays a critical role in both DNA repair and meiotic recombination. Yeast two-hybrid screening of a human testis cDNA library revealed a new protein, RAD51AP2 (RAD51 Associated Protein 2), that interacts strongly with RAD51. A full-length cDNA clone predicts a novel vertebrate specific protein of 1159 residues, and the RAD51AP2 transcript was observed only in meiotic tissue (i.e. adult testis and fetal ovary), suggesting a meiotic-specific function for RAD51AP2. In HEK293 cells the interaction of RAD51 with an ectopically-expressed recombinant large fragment of RAD51AP2 requires the C-terminal 57 residues of RAD51AP2. This RAD51-binding region shows 81% homology to the C-terminus of RAD51AP1/PIR51, an otherwise totally unrelated RAD51-binding partner that is ubiquitously expressed. Analyses using truncations and point mutations in both RAD51AP1 and RAD51AP2 demonstrate that these proteins use the same structural motif for RAD51 binding. RAD54 shares some homology with this RAD51-binding motif, but this homologous region plays only an accessory role to the adjacent main RAD51-interacting region, which has been narrowed here to 40 amino acids. A novel protein, RAD51AP2, has been discovered that interacts with RAD51 through a C-terminal motif also present in RAD51AP1.

  17. Rad51 Paralogs Remodel Pre-synaptic Rad51 Filaments to Stimulate Homologous Recombination.

    Science.gov (United States)

    Taylor, Martin R G; Špírek, Mário; Chaurasiya, Kathy R; Ward, Jordan D; Carzaniga, Raffaella; Yu, Xiong; Egelman, Edward H; Collinson, Lucy M; Rueda, David; Krejci, Lumir; Boulton, Simon J

    2015-07-16

    Repair of DNA double strand breaks by homologous recombination (HR) is initiated by Rad51 filament nucleation on single-stranded DNA (ssDNA), which catalyzes strand exchange with homologous duplex DNA. BRCA2 and the Rad51 paralogs are tumor suppressors and critical mediators of Rad51. To gain insight into Rad51 paralog function, we investigated a heterodimeric Rad51 paralog complex, RFS-1/RIP-1, and uncovered the molecular basis by which Rad51 paralogs promote HR. Unlike BRCA2, which nucleates RAD-51-ssDNA filaments, RFS-1/RIP-1 binds and remodels pre-synaptic filaments to a stabilized, "open," and flexible conformation, in which the ssDNA is more accessible to nuclease digestion and RAD-51 dissociation rate is reduced. Walker box mutations in RFS-1, which abolish filament remodeling, fail to stimulate RAD-51 strand exchange activity, demonstrating that remodeling is essential for RFS-1/RIP-1 function. We propose that Rad51 paralogs stimulate HR by remodeling the Rad51 filament, priming it for strand exchange with the template duplex. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Rad51 Promoter-Targeted Gene Therapy Is Effective for In Vivo Visualization and Treatment of Cancer

    Science.gov (United States)

    Hine, Christopher M; Seluanov, Andrei; Gorbunova, Vera

    2012-01-01

    Rad51 protein is overexpressed in a wide range of human cancers. Our previous in vitro studies demonstrated that a construct comprised Rad51 promoter driving expression of the diphtheria toxin A gene (pRad51-diphtheria toxin A (DTA)) destroys a variety of human cancer cell lines, with minimal to no toxicity to normal human cells. Here we delivered Rad51 promoter-based constructs in vivo using linear polyethylenimine nanoparticles, in vivo jetPEI, to visualize and treat tumors in mice with HeLa xenografts. For tumor detection, we used pRad51-Luc, a construct containing the firefly luciferase under the Rad51 promoter, administered by intraperitoneal (IP) injection. Tumors were detected with an in vivo bioluminescent camera. All mice with cancer displayed strong bioluminescence, while mice without cancer displayed no detectable bioluminescence. Treatment with pRad51-DTA/jetPEI decreased tumor mass of subcutaneous (SC) and IP tumors by sixfold and fourfold, respectively, along with the strong reduction of malignant ascites. Fifty percent of the mice with SC tumors were cancer-free after six pRad51-DTA/jetPEI injections, and for the mice with IP tumors, mean survival time increased by 90% compared to control mice. This study demonstrates the clinical potential of pRad51-based constructs delivered by nanoparticles for the diagnostics and treatment of a wide range of cancers. PMID:22008909

  19. A chemical compound that stimulates the human homologous recombination protein RAD51

    OpenAIRE

    Jayathilaka, Krishanthi; Sheridan, Sean D.; Bold, Tyler D.; Bochenska, Katarzyna; Logan, Hillary L.; Weichselbaum, Ralph. R.; Bishop, Douglas K.; Connell, Philip P.

    2008-01-01

    RAD51 and other members of the RecA family of strand exchange proteins assemble on ssDNA to form presynaptic filaments, which carry out the central steps of homologous recombination. A microplate-based assay was developed for high-throughput measurement of hRAD51 filament formation on ssDNA. With this method, a 10,000 compound library was screened, leading to the identification of a small molecule (RS-1) that enhances hRAD51 binding in a wide range of biochemical conditions. Salt titration ex...

  20. Outcomes of US BI-RADS 4A, 4B, and 4C Lesions

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jae Wang; Ko, Eun Young; Han, Boo Kyung; Shin, Jung Hee; Kang, Seok Seon; Hahn, Soo Yeon [Samsung Medical Center, Sungkyunkwan University College of Medicine, Seoul (Korea, Republic of)

    2009-12-15

    The aim of our study was to evaluate the outcomes of sonographic (US) BIRADS category 4 lesions according to subcategories 4A, 4B, and 4C and palpability. We retrospectively reviewed the pathology results of 512 US BI-RADS category 4 lesions in 460 patients after ultrasound-guided percutaneous biopsy (n = 435) and surgical biopsy (n = 77). We analyzed the results according to subcategories 4A, 4B, 4C, and palpability, and compared outcomes of five breast radiologists. In BI-RADS 4A lesions (n = 302), biopsy results indicated 48 malignancies(15.9%). In BI-RADS 4B lesions (n = 113), biopsy revealed 69 malignancies (61.1%). Among BI-RADS 4C lesions (n = 97), 87 lesions were malignancies (89.7 %). Palpability had no correlation with the rate of malignancy in BI-RADS category 4 lesions, and the rate of malignancy for category 4A ranged widely from 8.1% - 26.4%. The outcomes of US BI-RADS category 4 lesions according to subcategories varied widely between radiologists, especially for 4A lesions. The US finding itself warrants a BI-RADS 4 subcategory. In category 4 lesions, the malignant rate was the same between palpable and nonpalpable lesions

  1. Use of the Rad51 promoter for targeted anti-cancer therapy

    Science.gov (United States)

    Hine, Christopher M.; Seluanov, Andrei; Gorbunova, Vera

    2008-01-01

    Rad51 protein, involved in homologous recombination, is overexpressed in a variety of tumors, and its expression is correlated with a poor prognosis. Here we propose to exploit the overexpression of Rad51 in cancer cells to design a Rad51 promoter-based anticancer therapy. On average, Rad51 mRNA and protein levels are increased in cancer cells four- and sixfold, respectively. Serendipitously, we discovered that when the Rad51 ORF is replaced with another ORF, the difference in promoter activity between normal and cancer cells increases to an average of 840-fold with a maximum difference of 12,500-fold. This dramatic difference in activity has high therapeutic potential. We demonstrate that the fusion of Rad51 promoter to diphtheria toxin A (DTA) gene kills a variety of cancer cell types, including breast cancer, fibrosarcoma, and cervical cancer cells, with minimal effect on normal breast epithelial cells and normal fibroblasts. Our results suggest that therapies based on the Rad51 promoter will be highly tumor specific and open new avenues for targeting a broad range of cancers. PMID:19106292

  2. Synergistic interactions between RAD5, RAD16, and RAD54, three partially homologous yeast DNA repair genes each in a different repair pathway

    Energy Technology Data Exchange (ETDEWEB)

    Glassner, B.J. [Univ. of California, Berkeley, CA (United States); Mortimer, R.K. [Univ. of California, Berkeley, CA (United States)]|[Lawrence Berkeley Laboratory, Berkeley, CA (United States)

    1994-07-01

    Considerable homology has recently been noted between the proteins encoded by the RAD5, RAD16 and RAD54 genes of Saccharomyces cerevisiae. These genes are members of the RAD6, RAD3 and RAD50 epistasis groups, respectively, which correspond to the three major DNA repair pathways in yeast. These proteins also share homology with other eucaryotic proteins, including those encoded by SNF2 and MO1 of yeast, brahma and lodestar of Drosophila and the human ERCC6 gene. The homology shares features with known helicases, suggesting a newly identified helicase subfamily. We have constructed a series of congenic single-, double- and triple-deletion mutants involving RAD5, RAD16 and RAD54 to examine the interactions between these genes. Each deletion mutation alone has only a moderate effect on survival after exposure to UV radiation. Each pairwise-double mutant exhibits marked synergism. The triple-deletion mutant displays further synergism. These results confirm the assignment of the RAD54 gene to the RAD50 epistasis group and suggest that the RAD16 gene plays a larger role in DNA repair after exposure to UV radiation than has been suggested previously. Additionally, the proteins encoded by RAD5, RAD16, and RAD54 may compete for the same substrate after damage induced by UV radiation, possibly at an early step in their respective pathways. 49 refs., 6 figs., 2 tabs.

  3. Isolation and characterization of yeast DNA repair genes. II. Isolation of plasmids that complement the mutations rad50-1, rad51-1, rad54-3, and rad55-3

    Energy Technology Data Exchange (ETDEWEB)

    Calderon, I.L.; Contopoulou, C.R.; Mortimer, R.K.

    1983-01-01

    Plasmids that complement the yeast mutations rad50-1, rad51-1, rad54-3, and rad55-3 were obtained by transforming strains that carried a leu2 marker and the particular rad mutation, with YEp 13 plasmids containing near random yeast DNA inserts. Integration of these plasmids or of fragments of these plasmids was accomplished. Genetic studies using the integrants established the presence of the genes RAD50, RAD54 and RAD55 in the respective plasmids. However, a BamHI subclone of the rad50-1 complementing plasmid failed to integrate at the RAD50 locus, indicating that no homology exists between this fragment and the RAD50 gene. A BamHI fragment for the RAD54 plasmid was shown to be internal to the RAD54 gene: its integration within a wild type copy of RAD54 causes the cell to become Rad/sup -/; its excision is X-ray inducible and restores the Rad/sup -/ phenotype. Since cells bearing a disrupted copy of RAD54 are able to survive, the author concludes that this is not essential.

  4. Nanoscale Ferroelectric Switchable Polarization and Leakage Current Behavior in (Ba0.50Sr0.50(Ti0.80Sn0.20O3 Thin Films Prepared Using Chemical Solution Deposition

    Directory of Open Access Journals (Sweden)

    Venkata Sreenivas Puli

    2015-01-01

    Full Text Available Nanoscale switchable ferroelectric (Ba0.50Sr0.50(Ti0.80Sn0.20O3-BSTS polycrystalline thin films with a perovskite structure were prepared on Pt/TiOx/SiO2/Si substrate by chemical solution deposition. X-ray diffraction (XRD spectra indicate that a cubic perovskite crystalline structure and Raman spectra revealed that a tetragonal perovskite crystalline structure is present in the thin films. Sr2+ and Sn4+ cosubstituted film exhibited the lowest leakage current density. Piezoresponse Force Microscopy (PFM technique has been employed to acquire out-of-plane (OPP piezoresponse images and local piezoelectric hysteresis loop in polycrystalline BSTS films. PFM phase and amplitude images reveal nanoscale ferroelectric switching behavior at room temperature. Square patterns with dark and bright contrasts were written by local poling and reversible nature of the piezoresponse behavior was established. Local piezoelectric butterfly amplitude and phase hysteresis loops display ferroelectric nature at nanoscale level. The significance of this paper is to present ferroelectric/piezoelectric nature in present BSTS films at nanoscale level and corroborating ferroelectric behavior by utilizing Raman spectroscopy. Thus, further optimizing physical and electrical properties, BSTS films might be useful for practical applications which include nonvolatile ferroelectric memories, data-storage media, piezoelectric actuators, and electric energy storage capacitors.

  5. RadNet Air Quality (Deployable) Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — RadNet Deployable Monitoring is designed to collect radiological and meteorological information and data asset needed to establish the impact of radiation levels on...

  6. ezRAD: a simplified method for genomic genotyping in non-model organisms

    Directory of Open Access Journals (Sweden)

    Robert J. Toonen

    2013-11-01

    Full Text Available Here, we introduce ezRAD, a novel strategy for restriction site–associated DNA (RAD that requires little technical expertise or investment in laboratory equipment, and demonstrate its utility for ten non-model organisms across a wide taxonomic range. ezRAD differs from other RAD methods primarily through its use of standard Illumina TruSeq library preparation kits, which makes it possible for any laboratory to send out to a commercial genomic core facility for library preparation and next-generation sequencing with virtually no additional investment beyond the cost of the service itself. This simplification opens RADseq to any lab with the ability to extract DNA and perform a restriction digest. ezRAD also differs from others in its flexibility to use any restriction enzyme (or combination of enzymes that cuts frequently enough to generate fragments of the desired size range, without requiring the purchase of separate adapters for each enzyme or a sonication step, which can further decrease the cost involved in choosing optimal enzymes for particular species and research questions. We apply this method across a wide taxonomic diversity of non-model organisms to demonstrate the utility and flexibility of our approach. The simplicity of ezRAD makes it particularly useful for the discovery of single nucleotide polymorphisms and targeted amplicon sequencing in natural populations of non-model organisms that have been historically understudied because of lack of genomic information.

  7. ezRAD: a simplified method for genomic genotyping in non-model organisms.

    Science.gov (United States)

    Toonen, Robert J; Puritz, Jonathan B; Forsman, Zac H; Whitney, Jonathan L; Fernandez-Silva, Iria; Andrews, Kimberly R; Bird, Christopher E

    2013-01-01

    Here, we introduce ezRAD, a novel strategy for restriction site-associated DNA (RAD) that requires little technical expertise or investment in laboratory equipment, and demonstrate its utility for ten non-model organisms across a wide taxonomic range. ezRAD differs from other RAD methods primarily through its use of standard Illumina TruSeq library preparation kits, which makes it possible for any laboratory to send out to a commercial genomic core facility for library preparation and next-generation sequencing with virtually no additional investment beyond the cost of the service itself. This simplification opens RADseq to any lab with the ability to extract DNA and perform a restriction digest. ezRAD also differs from others in its flexibility to use any restriction enzyme (or combination of enzymes) that cuts frequently enough to generate fragments of the desired size range, without requiring the purchase of separate adapters for each enzyme or a sonication step, which can further decrease the cost involved in choosing optimal enzymes for particular species and research questions. We apply this method across a wide taxonomic diversity of non-model organisms to demonstrate the utility and flexibility of our approach. The simplicity of ezRAD makes it particularly useful for the discovery of single nucleotide polymorphisms and targeted amplicon sequencing in natural populations of non-model organisms that have been historically understudied because of lack of genomic information.

  8. Analysis list: Rad23b [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Rad23b Pluripotent stem cell + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Rad2...3b.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Rad23b.5.tsv http://dbarchive.biosc...iencedbc.jp/kyushu-u/mm9/target/Rad23b.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Rad23b.Plu

  9. Synthesis and structure of (Rb0.50Ba0.25)[UO2(CH3COO)3

    Science.gov (United States)

    Serezhkina, L. B.; Peresypkina, E. V.; Virovets, A. V.; Klepov, V. V.

    2010-03-01

    A new compound (Rb0.50Ba0.25)[UO2(CH3COO)3] is synthesized and its crystal structure is studied by X-ray diffraction. The compound crystallizes in the form of yellow plates belonging to the cubic crystal system. The unit cell parameter a = 17.0367(1) Å, V = 4944.89(5) Å3, space group I bar 4 3 d, Z = 16, and R = 0.0182. The coordination polyhedron of the uranium atom is a hexagonal bipyramid with oxygen atoms of three acetate groups and the uranyl group in the vertices. The crystal chemical formula of the uranium-containing group is AB {3/01}( A = UO{2/2+}, B 01 = CH3COO-). The oxygen atoms of the acetate groups that enter the coordination polyhedron of uranium are bound to barium and rubidium atoms.

  10. Arabidopsis RAD51, RAD51C and XRCC3 proteins form a complex and facilitate RAD51 localization on chromosomes for meiotic recombination.

    Directory of Open Access Journals (Sweden)

    Hang Su

    2017-05-01

    Full Text Available Meiotic recombination is required for proper homologous chromosome segregation in plants and other eukaryotes. The eukaryotic RAD51 gene family has seven ancient paralogs with important roles in mitotic and meiotic recombination. Mutations in mammalian RAD51 homologs RAD51C and XRCC3 lead to embryonic lethality. In the model plant Arabidopsis thaliana, RAD51C and XRCC3 homologs are not essential for vegetative development but are each required for somatic and meiotic recombination, but the mechanism of RAD51C and XRCC3 in meiotic recombination is unclear. The non-lethal Arabidopsis rad51c and xrcc3 null mutants provide an opportunity to study their meiotic functions. Here, we show that AtRAD51C and AtXRCC3 are components of the RAD51-dependent meiotic recombination pathway and required for normal AtRAD51 localization on meiotic chromosomes. In addition, AtRAD51C interacts with both AtRAD51 and AtXRCC3 in vitro and in vivo, suggesting that these proteins form a complex (es. Comparison of AtRAD51 foci in meiocytes from atrad51, atrad51c, and atxrcc3 single, double and triple heterozygous mutants further supports an interaction between AtRAD51C and AtXRCC3 that enhances AtRAD51 localization. Moreover, atrad51c-/+ atxrcc3-/+ double and atrad51-/+ atrad51c-/+ atxrcc3-/+ triple heterozygous mutants have defects in meiotic recombination, suggesting the role of the AtRAD51C-AtXRCC3 complex in meiotic recombination is in part AtRAD51-dependent. Together, our results support a model in which direct interactions between the RAD51C-XRCC3 complex and RAD51 facilitate RAD51 localization on meiotic chromosomes and RAD51-dependent meiotic recombination. Finally, we hypothesize that maintenance of RAD51 function facilitated by the RAD51C-XRCC3 complex could be highly conserved in eukaryotes.

  11. Differential contributions of mammalian Rad54 paralogs to recombination, DNA damage repair, and meiosis.

    NARCIS (Netherlands)

    J. Wesoly (Joanna); S. Agarwal (Sheba); S. Sigurdsson (Stefan); W. Bussen (Wendy); S. Komen (Stephen); J. Qin (Jian); H. van Steeg (Harry); J. van Benthem (Jan); E. Wassenaar (Evelyne); W.M. Baarends (Willy); M. Ghazvini (Mehrnaz); A. Tafel (Agnieszka); H. Heath (Helen); N.J. Galjart (Niels); J. Essers (Jeroen); J.A. Grootegoed (Anton); N. Arnheim (Norman); O.Y. Bezzubova (Olga); J-M. Buerstedde; P. Sung (Patrick); R. Kanaar (Roland)

    2006-01-01

    textabstractHomologous recombination is a versatile DNA damage repair pathway requiring Rad51 and Rad54. Here we show that a mammalian Rad54 paralog, Rad54B, displays physical and functional interactions with Rad51 and DNA that are similar to those of Rad54. While ablation of Rad54 in mouse embryoni

  12. Contribution of Germline Mutations in the RAD51B, RAD51C, and RAD51D Genes to Ovarian Cancer in the Population

    DEFF Research Database (Denmark)

    Song, Honglin; Dicks, Ed; Ramus, Susan J;

    2015-01-01

    PURPOSE: The aim of this study was to estimate the contribution of deleterious mutations in the RAD51B, RAD51C, and RAD51D genes to invasive epithelial ovarian cancer (EOC) in the population and in a screening trial of individuals at high risk of ovarian cancer. PATIENTS AND METHODS: The coding s...

  13. Homologous and homeologous intermolecular gene conversion are not differentially affected by mutations in the DNA damage or the mismatch repair genes RAD1, RAD50, RAD51, RAD52, RAD54, PMS1 and MSH2

    Energy Technology Data Exchange (ETDEWEB)

    Porter, G.; Westmoreland, J.; Priebe, S. [National Institute of Environmental Health Sciences, Research Triangle Park, NC (United States)] [and others

    1996-06-01

    Mismatch repair (MMR) genes or genes involved in both DNA damage repair and homologous recombination might affect homeologous vs. homologous recombination differentially. Spontaneous mitotic gene conversion between a chromosome and a homologous or homeologous donor sequence (14% diverged) on a single copy plasmid was examined in wild-type Saccharomyces cerevisiae strains and in MMR or DNA damage repair mutants. Homologous recombination in rad51, rad52 and rad54 mutants was considerably reduced, while there was little effect of rad1, rad50, pms1 and msh2 null mutations. DNA divergence resulted in no differential effect on recombination rates in the wild type or the mutants; there was only a five- to 10-fold reduction in homeologous relative to homologous recombination regardless of background. Since DNA divergence is known to affect recombination in some systems, we propose that differences in the role of MMR depends on the mode of recombination and/or the level of divergence. Based on analysis of the recombination breakpoints, there is a minimum of three homologous bases required at a recombination junction. A comparison of Rad{sup +} vs. rad52 strains revealed that while all conversion tracts are continuous, elimination of RAD52 leads to the appearance of a novel class of very short conversion tracts. 67 refs., 5 figs., 4 tabs.

  14. Fission yeast Rad52 phosphorylation restrains error prone recombination pathways.

    Directory of Open Access Journals (Sweden)

    Angela Bellini

    Full Text Available Rad52 is a key protein in homologous recombination (HR, a DNA repair pathway dedicated to double strand breaks and recovery of blocked or collapsed replication forks. Rad52 allows Rad51 loading on single strand DNA, an event required for strand invasion and D-loop formation. In addition, Rad52 functions also in Rad51 independent pathways because of its ability to promote single strand annealing (SSA that leads to loss of genetic material and to promote D-loops formation that are cleaved by Mus81 endonuclease. We have previously reported that fission yeast Rad52 is phosphorylated in a Sty1 dependent manner upon oxidative stress and in cells where the early step of HR is impaired because of lack of Rad51. Here we show that Rad52 is also constitutively phosphorylated in mus81 null cells and that Sty1 partially impinges on such phosphorylation. As upon oxidative stress, the Rad52 phosphorylation in rad51 and mus81 null cells appears to be independent of Tel1, Rad3 and Cdc2. Most importantly, we show that mutating serine 365 to glycine (S365G in Rad52 leads to loss of the constitutive Rad52 phosphorylation observed in cells lacking Rad51 and to partial loss of Rad52 phosphorylation in cells lacking Mus81. Contrariwise, phosphorylation of Rad52-S365G protein is not affected upon oxidative stress. These results indicate that different Rad52 residues are phosphorylated in a Sty1 dependent manner in response to these distinct situations. Analysis of spontaneous HR at direct repeats shows that mutating serine 365 leads to an increase in spontaneous deletion-type recombinants issued from mitotic recombination that are Mus81 dependent. In addition, the recombination rate in the rad52-S365G mutant is further increased by hydroxyurea, a drug to which mutant cells are sensitive.

  15. Xe-bearing hydrocarbon ions: Observation of Xe.acetylene+rad and Xe.benzene+rad radical cations and calculations of their ground state structures

    Science.gov (United States)

    Cui, Zhong-hua; Attah, Isaac K.; Platt, Sean P.; Aziz, Saadullah G.; Kertesz, Miklos; El-Shall, M. S.

    2016-04-01

    This work reports evidence for novel types of Xe-bearing hydrocarbon radical cations. The Xe.acetylene+rad radical cation adduct is observed at nearly room temperature using the mass-selected drift cell technique. The irreversible addition of the Xe atom and the lack of back dissociation to HCCH+rad + Xe is consistent with the calculated binding energy of 0.85 eV to be contrasted with the metastable nature of the neutral Xe.acetylene adduct. The observed Xe.benzene+rad radical cation appears to be a weakly bound complex stabilized mainly by ion-induced dipole interaction consistent with a calculated binding energy in the range of 0.14-0.17 eV.

  16. Radiological information management system (RadIMS)

    Energy Technology Data Exchange (ETDEWEB)

    Oesterling, R.G.; Marko, S.A.; Tschaeche, A.N.

    1991-08-19

    Westinghouse Idaho Nuclear Company, Inc. (WINCO) is developing and implementing an information management system, known as RadIMS, to track and record personnel exposure to ionizing radiation. RadIMS has been designed to fulfill all the requirements of US Department of Energy (USDOE) Order 5480.11, Radiation Protection for Occupational Workers.'' This Order requires the contractor to maintain detailed radiation exposure records on all individuals who work at the facility. These records must be retrievable for the entire working life of the individual and be available to other USDOE contractors on request. To meet these general needs, RadIMS provides for retrieval of detailed, comprehensive individual exposure histories as well as the usual online interactions to accomplish day-today radiation protection operations. These two extremes of functionality require different approaches in the WINCO computing environment. The exposure histories include database text, paper, microfilm, and electronic bitmaps.

  17. Radiological information management system (RadIMS)

    Energy Technology Data Exchange (ETDEWEB)

    Oesterling, R.G.; Marko, S.A.; Tschaeche, A.N.

    1991-08-19

    Westinghouse Idaho Nuclear Company, Inc. (WINCO) is developing and implementing an information management system, known as RadIMS, to track and record personnel exposure to ionizing radiation. RadIMS has been designed to fulfill all the requirements of US Department of Energy (USDOE) Order 5480.11, ``Radiation Protection for Occupational Workers.`` This Order requires the contractor to maintain detailed radiation exposure records on all individuals who work at the facility. These records must be retrievable for the entire working life of the individual and be available to other USDOE contractors on request. To meet these general needs, RadIMS provides for retrieval of detailed, comprehensive individual exposure histories as well as the usual online interactions to accomplish day-today radiation protection operations. These two extremes of functionality require different approaches in the WINCO computing environment. The exposure histories include database text, paper, microfilm, and electronic bitmaps.

  18. Human Rad51 mediated DNA unwinding is facilitated by conditions that favour Rad51-dsDNA aggregation

    Directory of Open Access Journals (Sweden)

    Kulkarni Anagha

    2009-01-01

    Full Text Available Abstract Background Human Rad51 (RAD51, analogous to its bacterial homolog, RecA, binds and unwinds double stranded DNA (dsDNA in the presence of certain nucleotide cofactors. ATP hydrolysis is not required for this process, because even ATP non hydrolysable analogs like AMP-PNP and ATPγS, support DNA unwinding. Even ADP, the product of ATP hydrolysis, feebly supports DNA unwinding. Results We find that human Rad52 (RAD52 stimulates RAD51 mediated DNA unwinding in the presence of all Adenine nucleotide cofactors, (except in AMP and no nucleotide conditions that intrinsically fail to support unwinding reaction while enhancing aggregation of RAD51-dsDNA complexes in parallel. Interestingly, salt at low concentration can substitute the role of RAD52, in facilitating aggregation of RAD51-dsDNA complexes, that concomitantly also leads to better unwinding. Conclusion RAD52 itself being a highly aggregated protein perhaps acts as scaffold to bring together RAD51 and DNA molecules into large co-aggregates of RAD52-RAD51-DNA complexes to promote RAD51 mediated DNA unwinding reaction, when appropriate nucleotide cofactors are available, presumably through macromolecular crowding effects. Our work highlights the functional link between aggregation of protein-DNA complexes and DNA unwinding in RAD51 system.

  19. Evaluation of COTS Rad Detection Apps

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Eric [National Security Technologies, LLC. (NSTec), Mercury, NV (United States)

    2014-02-01

    Mobile applications are currently under distribution to smart phones utilizing the built-in charge coupled-device (CCD) camera as a radiation detector. The CCD detector has a very low but measurable gamma interaction cross section so the mechanism is feasible, especially for higher dose rate environments. Given that in a large release of radioactive material these ‘crowd sourced’ measurements will be put forth for consideration, a testing and evaluation of the accuracy and uncertainty of the Apps is a critical endeavor. Not only is the accuracy of the reported measurement of concern to the immediate user’s safety, a quantitative uncertainty is required for a government response such as the Federal Radiological Monitoring and Assessment Center (FRMAC) to accept the values for consideration in the determination of regions exceeding protective action guidelines. Already, prompted by the Fukushima nuclear material releases, several repositories of this crowd-sourced data have been created (http://japan.failedrobot.com, http://www.stubbytour.com/nuc/index_en.asp, and http://www.rdtn.org) although the question remains as to the reliability of measurements incorporated into these repositories. In cases of conflict between the real-time published crowd-sourced data and governmental protective actions prepared literature should be on-hand documenting why the difference, if any, exists. Four applications for iOS devices were obtained along with hardware to benchmark their performance. Gamma/X-Ray Detector by Stephan Hotto, Geiger Camera by Senscare, and RadioactivityCounter App by Hotray LTD are all the applications available for distribution within the US that utilize the CCD camera sensor for detection of radiation levels. The CellRad app under development by Idaho National Laboratory for the Android platform was evaluated. In addition, iRad Geiger with the associated hardware accessory was also benchmarked. Radiation fields were generated in a Cs-137 JL Shepherd

  20. The yeast recombinational repair protein Rad59 interacts with Rad52 and stimulates single-strand annealing.

    OpenAIRE

    Davis, A P; Symington, L. S.

    2001-01-01

    The yeast RAD52 gene is essential for homology-dependent repair of DNA double-strand breaks. In vitro, Rad52 binds to single- and double-stranded DNA and promotes annealing of complementary single-stranded DNA. Genetic studies indicate that the Rad52 and Rad59 proteins act in the same recombination pathway either as a complex or through overlapping functions. Here we demonstrate physical interaction between Rad52 and Rad59 using the yeast two-hybrid system and co-immunoprecipitation from yeas...

  1. Rad51-Rad52 mediated maintenance of centromeric chromatin in Candida albicans.

    Directory of Open Access Journals (Sweden)

    Sreyoshi Mitra

    2014-04-01

    Full Text Available Specification of the centromere location in most eukaryotes is not solely dependent on the DNA sequence. However, the non-genetic determinants of centromere identity are not clearly defined. While multiple mechanisms, individually or in concert, may specify centromeres epigenetically, most studies in this area are focused on a universal factor, a centromere-specific histone H3 variant CENP-A, often considered as the epigenetic determinant of centromere identity. In spite of variable timing of its loading at centromeres across species, a replication coupled early S phase deposition of CENP-A is found in most yeast centromeres. Centromeres are the earliest replicating chromosomal regions in a pathogenic budding yeast Candida albicans. Using a 2-dimensional agarose gel electrophoresis assay, we identify replication origins (ORI7-LI and ORI7-RI proximal to an early replicating centromere (CEN7 in C. albicans. We show that the replication forks stall at CEN7 in a kinetochore dependent manner and fork stalling is reduced in the absence of the homologous recombination (HR proteins Rad51 and Rad52. Deletion of ORI7-RI causes a significant reduction in the stalled fork signal and an increased loss rate of the altered chromosome 7. The HR proteins, Rad51 and Rad52, have been shown to play a role in fork restart. Confocal microscopy shows declustered kinetochores in rad51 and rad52 mutants, which are evidence of kinetochore disintegrity. CENP-ACaCse4 levels at centromeres, as determined by chromatin immunoprecipitation (ChIP experiments, are reduced in absence of Rad51/Rad52 resulting in disruption of the kinetochore structure. Moreover, western blot analysis reveals that delocalized CENP-A molecules in HR mutants degrade in a similar fashion as in other kinetochore mutants described before. Finally, co-immunoprecipitation assays indicate that Rad51 and Rad52 physically interact with CENP-ACaCse4 in vivo. Thus, the HR proteins Rad51 and Rad52

  2. TODRA, a lncRNA at the RAD51 Locus, Is Oppositely Regulated to RAD51, and Enhances RAD51-Dependent DSB (Double Strand Break) Repair.

    Science.gov (United States)

    Gazy, Inbal; Zeevi, David A; Renbaum, Paul; Zeligson, Sharon; Eini, Lital; Bashari, Dana; Smith, Yoav; Lahad, Amnon; Goldberg, Michal; Ginsberg, Doron; Levy-Lahad, Ephrat

    2015-01-01

    Expression of RAD51, a crucial player in homologous recombination (HR) and DNA double-strand break (DSB) repair, is dysregulated in human tumors, and can contribute to genomic instability and tumor progression. To further understand RAD51 regulation we functionally characterized a long non-coding (lnc) RNA, dubbed TODRA (Transcribed in the Opposite Direction of RAD51), transcribed 69bp upstream to RAD51, in the opposite direction. We demonstrate that TODRA is an expressed transcript and that the RAD51 promoter region is bidirectional, supporting TODRA expression (7-fold higher than RAD51 in this assay, p = 0.003). TODRA overexpression in HeLa cells induced expression of TPIP, a member of the TPTE family which includes PTEN. Similar to PTEN, we found that TPIP co-activates E2F1 induction of RAD51. Analysis of E2F1's effect on the bidirectional promoter showed that E2F1 binding to the same site that promotes RAD51 expression, results in downregulation of TODRA. Moreover, TODRA overexpression induces HR in a RAD51-dependent DSB repair assay, and increases formation of DNA damage-induced RAD51-positive foci. Importantly, gene expression in breast tumors supports our finding that E2F1 oppositely regulates RAD51 and TODRA: increased RAD51 expression, which is associated with an aggressive tumor phenotype (e.g. negative correlation with positive ER (r = -0.22, p = 0.02) and positive PR status (r = -0.27, pDSB repair in malignancy. Importantly, gene expression in breast tumors supports our finding that E2F1 oppositely regulates RAD51 and TODRA: increased RAD51 expression, which is associated with an aggressive tumor phenotype (e.g. negative correlation with positive ER (r = -0.22, p = 0.02) and positive PR status (r = -0.27, pDSB repair in malignancy.

  3. RadNet Air Data From Chicago, IL

    Science.gov (United States)

    This page presents radiation air monitoring and air filter analysis data for Chicago, IL from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  4. RadNet Air Data From Aurora, IL

    Science.gov (United States)

    This page presents radiation air monitoring and air filter analysis data for Aurora, IL from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  5. RadNet Air Data From Champaign, IL

    Science.gov (United States)

    This page presents radiation air monitoring and air filter analysis data for Champaign, ILfrom EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  6. RadNet Air Quality (Fixed Station) Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — RadNet is a national network of monitoring stations that regularly collect air for analysis of radioactivity. The RadNet network, which has stations in each State,...

  7. RadNet Air Data From Little Rock, AR

    Science.gov (United States)

    This page presents radiation air monitoring and air filter analysis data for Little Rock, AR from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  8. RadNet Air Data From Fort Worth, TX

    Science.gov (United States)

    This page presents radiation air monitoring and air filter analysis data for Fort Worth, TX from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  9. RadNet Air Data From Navajo Lake, NM

    Science.gov (United States)

    This page presents radiation air monitoring and air filter analysis data for Navajo Lake, NM from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  10. RadNet Air Data From San Diego, CA

    Science.gov (United States)

    This page presents radiation air monitoring and air filter analysis data for San Diego, CA from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  11. RadNet Air Data From Idaho Falls, ID

    Science.gov (United States)

    This page presents radiation air monitoring and air filter analysis data for Idaho Falls, ID from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  12. Promotion of Homologous Recombination and Genomic Stability byRAD51AP1 via RAD51 Recombinase Enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Wiese, Claudia; Dray, Eloise; Groesser, Torsten; San Filippo,Joseph; Shi, Idina; Collins, David W.; Tsai, Miaw-Sheue; Williams,Gareth; Rydberg, Bjorn; Sung, Patrick; Schild, David

    2007-04-11

    Homologous recombination (HR) repairs chromosome damage and is indispensable for tumor suppression in humans. RAD51 mediates the DNA strand pairing step in HR. RAD51AP1 (RAD51 Associated Protein 1) is a RAD51-interacting protein whose function has remained elusive. Knockdown of RAD51AP1 in human cells by RNA interference engenders sensitivity to different types of genotoxic stress. Moreover, RAD51AP1-depleted cells are impaired for the recombinational repair of a DNA double-strand break and exhibit chromatid breaks both spontaneously and upon DNA damaging treatment. Purified RAD51AP1 binds dsDNA and RAD51, and it greatly stimulates the RAD51-mediated D-loop reaction. Biochemical and cytological results show that RAD51AP1 functions at a step subsequent to the assembly of the RAD51-ssDNA nucleoprotein filament. Our findings provide the first evidence that RAD51AP1 helps maintain genomic integrity via RAD51 recombinase enhancement.

  13. HiRadMat: materials under scrutiny

    CERN Multimedia

    Anaïs Schaeffer

    2011-01-01

    CERN's new facility, HiRadMat (High Radiation to Materials), which is designed to test materials for the world's future particle accelerators, should be operational and welcoming its first experiments by the end of the year.   The HiRadMat facility, located in the TNC tunnel. The materials used in the LHC and its experiments are exposed to very high-energy particles. The LHC machine experts obviously didn't wait for the first collisions in the world's most powerful accelerator to put the materials through their paces - the equipment was validated following a series of stringent tests. And these tests will get even tougher now, with the arrival of HiRadMat. The tunnel that formerly housed the West Area Neutrino Facility (WANF) has been completely revamped to make way for CERN's latest facility, HiRadMat. Supported by the Radioprotection service, a team from the Engineering (EN) Department handled the dismantling operations from October 2009 to December 2010. "We could only work on disman...

  14. Ionizing radiation-induced foci formation of mammalian Rad51 and Rad54 depends on the Rad51 paralogs, but not on Rad52.

    NARCIS (Netherlands)

    Veelen, L.R. van; Essers, J.; Rakt, M.W.M.M. van de; Odijk, H.; Pastink, A.; Zdzienicka, M.Z.; Paulusma, C.C.; Kanaar, R.

    2005-01-01

    Homologous recombination is of major importance for the prevention of genomic instability during chromosome duplication and repair of DNA damage, especially double-strand breaks. Biochemical experiments have revealed that during the process of homologous recombination the RAD52 group proteins, inclu

  15. RAD51B in Familial Breast Cancer

    DEFF Research Database (Denmark)

    Pelttari, Liisa M; Khan, Sofia; Vuorela, Mikko

    2016-01-01

    Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predisposition......, particularly in the context of familial breast cancer in Finland. We sequenced the coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for identification of possible recurrent founder mutations. In addition, we studied the known rs999737, rs2588809, and rs1314913 SNPs and RAD......51B haplotypes in 44,791 breast cancer cases and 43,583 controls from 40 studies participating in the Breast Cancer Association Consortium (BCAC) that were genotyped on a custom chip (iCOGS). We identified one putatively pathogenic missense mutation c.541C>T among the Finnish cancer patients...

  16. Combined experimental and theoretical study on the differential elastic scattering cross sections for acetone by electron impact energy of 7.0-50 eV

    Science.gov (United States)

    Pastega, D. F.; Lange, E.; Ameixa, J.; Barbosa, A. S.; Blanco, F.; García, G.; Bettega, M. H. F.; Limão-Vieira, P.; Ferreira da Silva, F.

    2016-03-01

    We report elastic differential cross sections (DCSs) for electron interactions with acetone, C3H6O . The incident electron energy range was 7.0-50 eV, and the scattered electron angular range for the differential measurements varied from 10° to 120°. The calculated cross sections were obtained with two different methodologies, the Schwinger multichannel method with pseudopotentials (SMCPP), and the independent-atom method with screening-corrected additivity rule (IAM-SCAR). The present elastic DCSs have been found to agree well with the results of IAM-SCAR calculations above 20 eV, and also with the SMC calculations below 30 eV. Although some discrepancies were found for lower energies, the agreement between the SMCPP data and the DCSs obtained with the IAM-SCAR method improves, as expected, as the impact energy increases. Comparison with previous DCSs shows good agreement albeit the present data is extended down to lower electron impact energies. We find a low-lying π* shape resonance located at 2.6 eV, in agreement with recent results on electron collisions with acetone [M. G. P. Homem et al., Phys. Rev. A 92, 032711 (2015), 10.1103/PhysRevA.92.032711]. The presence of a σ* resonance is also discussed.

  17. Co-expression with RadA and the characterization of stRad55B, a RadA paralog from the hyperthermophilic crenarchaea Sulfolobus tokodaii

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    ST0838 (designed stRad55B) is one of the four RadA paralogs (or Rad55 homologues) in the genome of the hyperthermophilic crenarchaeon Sulfolobus tokodaii. The gene is induced by UV irradiation, sug-gesting that it is involved in DNA recombinational repair in this organism. However, this protein could not be expressed normally in vitro. In this study, thermostable and soluble stRad55B was obtained by co-expression with S. tokodaii RadA (stRadA) in E. coli, and the enzymatic properties were examined. It was found that stRad55B bound ssDNA preferentially and had a very weak ATPase activity that was not stimulated by DNA. The recombinant protein inhibited the strand exchange activity promoted by stRadA, indicating that stRad55B might be an inhibitor to the homologous recombination in this ar-chaeon. The results will be helpful for further functional and interaction analysis of RadA paralogs and for the understanding of the mechanism of recombinational repair in archaea.

  18. Co-expression with RadA and the characterization of stRad55B, a RadA paralog from the hyperthermophilic crenarchaea Sulfolobus tokodaii

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    ST0838 (designed stRad55B) is one of the four RadA paralogs (or Rad55 homologues) in the genome of the hyperthermophilic crenarchaeon Sulfolobus tokodaii. The gene is induced by UV irradiation, suggesting that it is involved in DNA recombinational repair in this organism. However, this protein could not be expressed normally in vitro. In this study, thermostable and soluble stRad55B was obtained by co-expression with S. tokodaii RadA (stRadA) in E. coli, and the enzymatic properties were examined. It was found that stRad55B bound ssDNA preferentially and had a very weak ATPase activity that was not stimulated by DNA. The recombinant protein inhibited the strand exchange activity promoted by stRadA, indicating that stRad55B might be an inhibitor to the homologous recombination in this archaeon. The results will be helpful for further functional and interaction analysis of RadA paralogs and for the understanding of the mechanism of recombinational repair in archaea.

  19. Effect of Mn substitution on the microstructure and magnetic properties of Ni{sub 0.50-x}Zn{sub 0.50-x}Mn{sub 2x}Fe{sub 2}O{sub 4} ferrite prepared by the citrate-nitrate precursor method

    Energy Technology Data Exchange (ETDEWEB)

    Bueno, Alexandre R. [DCMM, Pontificia Universidade Catolica do Rio de Janeiro, Rua Marques de Sao Vicente 225, 22453-900, Rio de Janeiro, RJ (Brazil)], E-mail: arbueno@rdc.puc-rio.br; Gregori, Maria L. [IPqM, Instituto de Pesquisas da Marinha, Rua Ipiru, Praia da Bica, Ilha do Governador, 21931-090, Rio de Janeiro, RJ (Brazil); Nobrega, Maria C.S. [COPPE UFRJ PEMM, Universidade Federal do Rio de Janeiro, C.P. 68505, Ilha do Fundao 21945-970, Rio de Janeiro, RJ (Brazil)

    2007-10-15

    Ni{sub 0.50-x}Zn{sub 0.50-x}Mn{sub 2x}Fe{sub 2}O{sub 4} ferrites (with x values ranging from 0.00 to 0.15 in steps of 0.05) were synthesized by the nitrate-citrate precursor method. Their microstructure and magnetic properties were studied as a function of the Mn{sup 2+} content. Phase formation was characterized by the X-ray diffraction method (XRD), and the microstructure was examined by scanning electron microscopy (SEM). The density of sintered bodies was measured by the Archimedes method, while the magnetic properties were investigated by magnetic hysteresisgraphy. All the ferrite samples displayed the low-coercive forces (H{sub c}) characteristic of soft magnetic materials. The results indicated that Mn substitution increases induction magnetization (B{sub m}) and remanent magnetization (B{sub r}). The lattice parameter was found to increase with increasing Mn substitution. The addition of Mn enhanced the material's densification, resulting in a maximum density of 4.52 g cm{sup -3}. Efforts should be made to develop denser microstructures in order to improve the physical properties of Mn-substituted NiZn ferrites.

  20. Rad51 and Rad52 are involved in homologous recombination of replicating herpes simplex virus DNA.

    Directory of Open Access Journals (Sweden)

    Ka-Wei Tang

    Full Text Available Replication of herpes simplex virus 1 is coupled to recombination, but the molecular mechanisms underlying this process are poorly characterized. The role of Rad51 and Rad52 recombinases in viral recombination was examined in human fibroblast cells 1BR.3.N (wild type and in GM16097 with replication defects caused by mutations in DNA ligase I. Intermolecular recombination between viruses, tsS and tsK, harboring genetic markers gave rise to ∼17% recombinants in both cell lines. Knock-down of Rad51 and Rad52 by siRNA reduced production of recombinants to 11% and 5%, respectively, in wild type cells and to 3% and 5%, respectively, in GM16097 cells. The results indicate a specific role for Rad51 and Rad52 in recombination of replicating herpes simplex virus 1 DNA. Mixed infections using clinical isolates with restriction enzyme polymorphisms in the US4 and US7 genes revealed recombination frequencies of 0.7%/kbp in wild type cells and 4%/kbp in GM16097 cells. Finally, tandem repeats in the US7 gene remained stable upon serial passage, indicating a high fidelity of recombination in infected cells.

  1. RAD51B in Familial Breast Cancer

    Science.gov (United States)

    Pelttari, Liisa M.; Khan, Sofia; Vuorela, Mikko; Kiiski, Johanna I.; Vilske, Sara; Nevanlinna, Viivi; Ranta, Salla; Schleutker, Johanna; Winqvist, Robert; Kallioniemi, Anne; Dörk, Thilo; Bogdanova, Natalia V.; Figueroa, Jonine; Pharoah, Paul D. P.; Schmidt, Marjanka K.; Dunning, Alison M.; García-Closas, Montserrat; Bolla, Manjeet K.; Dennis, Joe; Michailidou, Kyriaki; Wang, Qin; Hopper, John L.; Southey, Melissa C.; Rosenberg, Efraim H.; Fasching, Peter A.; Beckmann, Matthias W.; Peto, Julian; dos-Santos-Silva, Isabel; Sawyer, Elinor J.; Tomlinson, Ian; Burwinkel, Barbara; Surowy, Harald; Guénel, Pascal; Truong, Thérèse; Bojesen, Stig E.; Nordestgaard, Børge G.; Benitez, Javier; González-Neira, Anna; Neuhausen, Susan L.; Anton-Culver, Hoda; Brenner, Hermann; Arndt, Volker; Meindl, Alfons; Schmutzler, Rita K.; Brauch, Hiltrud; Brüning, Thomas; Lindblom, Annika; Margolin, Sara; Mannermaa, Arto; Hartikainen, Jaana M.; Chenevix-Trench, Georgia; Van Dyck, Laurien; Janssen, Hilde; Chang-Claude, Jenny; Rudolph, Anja; Radice, Paolo; Peterlongo, Paolo; Hallberg, Emily; Olson, Janet E.; Giles, Graham G.; Milne, Roger L.; Haiman, Christopher A.; Schumacher, Fredrick; Simard, Jacques; Dumont, Martine; Kristensen, Vessela; Borresen-Dale, Anne-Lise; Zheng, Wei; Beeghly-Fadiel, Alicia; Grip, Mervi; Andrulis, Irene L.; Glendon, Gord; Devilee, Peter; Seynaeve, Caroline; Hooning, Maartje J.; Collée, Margriet; Cox, Angela; Cross, Simon S.; Shah, Mitul; Luben, Robert N.; Hamann, Ute; Torres, Diana; Jakubowska, Anna; Lubinski, Jan; Couch, Fergus J.; Yannoukakos, Drakoulis; Orr, Nick; Swerdlow, Anthony; Darabi, Hatef; Li, Jingmei; Czene, Kamila; Hall, Per; Easton, Douglas F.; Mattson, Johanna; Blomqvist, Carl; Aittomäki, Kristiina; Nevanlinna, Heli

    2016-01-01

    Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predisposition, particularly in the context of familial breast cancer in Finland. We sequenced the coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for identification of possible recurrent founder mutations. In addition, we studied the known rs999737, rs2588809, and rs1314913 SNPs and RAD51B haplotypes in 44,791 breast cancer cases and 43,583 controls from 40 studies participating in the Breast Cancer Association Consortium (BCAC) that were genotyped on a custom chip (iCOGS). We identified one putatively pathogenic missense mutation c.541C>T among the Finnish cancer patients and subsequently genotyped the mutation in additional breast cancer cases (n = 5259) and population controls (n = 3586) from Finland and Belarus. No significant association with breast cancer risk was seen in the meta-analysis of the Finnish datasets or in the large BCAC dataset. The association with previously identified risk variants rs999737, rs2588809, and rs1314913 was replicated among all breast cancer cases and also among familial cases in the BCAC dataset. The most significant association was observed for the haplotype carrying the risk-alleles of all the three SNPs both among all cases (odds ratio (OR): 1.15, 95% confidence interval (CI): 1.11–1.19, P = 8.88 x 10−16) and among familial cases (OR: 1.24, 95% CI: 1.16–1.32, P = 6.19 x 10−11), compared to the haplotype with the respective protective alleles. Our results suggest that loss-of-function mutations in RAD51B are rare, but common variation at the RAD51B region is significantly associated with familial breast cancer risk. PMID:27149063

  2. Silicon doping of semipolar (11 2 bar 2)Alx Ga1-x N (0.50 ≤ x ≤ 0.55)

    Science.gov (United States)

    Dinh, Duc V.; Pampili, Pietro; Parbrook, Peter J.

    2016-10-01

    The effect of silicon doping on the growth and properties of ∼ 1.0 μm-thick Alx Ga1-x N(0.50 ≤ x ≤ 0.55) layers grown on semipolar (11 2 bar 2) AlN templates by metalorganic vapour phase epitaxy was studied. The layers were grown with different disilane/group-III precursors ratios that varied from 2.8×10-5 to 3.4×10-4. The surface morphology of the Si-doped (11 2 bar 2) AlGaN layers showed undulations along [ 1 1 bar 00 ] AlGaN , AlN with a root-mean square roughness of about 4.0 nm within a scan range of 20 × 20 μm2 . Different photoluminescence peaks have been linked to negatively charged cation vacancies (VIII3-) and their complexes with impurities such as VIII3- - 3ON1+, (VIII complex)1-, and (VIII complex)2-. The optimised AlGaN:Si layer exhibited a carrier concentration of ∼1.2×1019 cm-3, a carrier mobility of 30.7 cm2/V s, and a resistivity of 0.018 Ω cm , as determined by Hall-effect measurements at room temperature. A correlation between the resistivity and luminescence emission intensities of AlGaN near-band-edge and impurity-related complexes was found.

  3. Regulation of the Saccharomyces cerevisiae DNA repair gene RAD16.

    Science.gov (United States)

    Bang, D D; Timmermans, V; Verhage, R; Zeeman, A M; van de Putte, P; Brouwer, J

    1995-05-25

    The RAD16 gene product has been shown to be essential for the repair of the silenced mating type loci [Bang et al. (1992) Nucleic Acids Res. 20, 3925-3931]. More recently we demonstrated that the RAD16 and RAD7 proteins are also required for repair of non-transcribed strands of active genes in Saccharomyces cerevisiae [Waters et al. (1993) Mol. Gen. Genet. 239, 28-32]. We have studied the regulation of the RAD16 gene and found that the RAD16 transcript levels increased up to 7-fold upon UV irradiation. Heat shock at 42 degrees C also results in elevated levels of RAD16 mRNA. In sporulating MAT alpha/MATa diploid cells RAD16 mRNA is also induced. The basal level of the RAD16 transcript is constant during the mitotic cell cycle. G1-arrested cells show normal induction of RAD16 mRNA upon UV irradiation demonstrating that the induction is not a secondary consequence of G2 cell cycle arrest following UV irradiation. However, in cells arrested in G1 the induction of RAD16 mRNA after UV irradiation is not followed by a rapid decline as occurs in normal growing cells suggesting that the down regulation of RAD16 transcription is dependent on progression into the cell cycle.

  4. Analysis list: RAD21 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available RAD21 Blood,Breast,Digestive tract,Liver,Neural,Pluripotent stem cell,Uterus + hg19 http:...//dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/RAD21.1.tsv http://dbarchive.biosciencedbc.jp/kyushu...-u/hg19/target/RAD21.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/RAD21.10.tsv http://dbarch...ive.biosciencedbc.jp/kyushu-u/hg19/colo/RAD21.Blood.tsv,http://dbarchive.bioscien...cedbc.jp/kyushu-u/hg19/colo/RAD21.Breast.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/RAD21.Digestive_tract.tsv,http:

  5. Analysis list: Rad21 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Rad21 Blood,Digestive tract,Embryonic fibroblast,Liver,Neural,Pluripotent stem cell...,Spleen + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Rad21.1.tsv http://dbarchive.bioscienced...bc.jp/kyushu-u/mm9/target/Rad21.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Rad21.10.tsv htt...p://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Rad21.Blood.tsv,http://dbarchive....biosciencedbc.jp/kyushu-u/mm9/colo/Rad21.Digestive_tract.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Rad2

  6. Regulation of RAD54- and RAD52-lacZ gene fusions in Saccharomyces cerevisiae in response to DNA damage

    Energy Technology Data Exchange (ETDEWEB)

    Cole, G.M.; Schild, D.; Lovett, S.T.; Mortimer, R.K.

    1987-03-01

    The RAD52 and RAD54 genes in the yeast Saccharomyces cerevisiae are involved in both DNA repair and DNA recombination. RAD54 has recently been shown to be inducible by X-rays, while RAD52 is not. To further investigate the regulation of these genes, we constructed gene fusions using 5' regions upstream of the RAD52 and RAD54 genes and a 3'-terminal fragment of the Escherichia coli beta-galactosidase gene. Yeast transformants with either an integrated or an autonomously replicating plasmid containing these fusions expressed beta-galactosidase activity constitutively. In addition, the RAD54 gene fusion was inducible in both haploid and diploid cells in response to the DNA-damaging agents X-rays, UV light, and methyl methanesulfonate, but not in response to heat shock. The RAD52-lacZ gene fusion showed little or no induction in response to X-ray or UV radiation nor methyl methanesulfonate. Typical induction levels for RAD54 in cells exposed to such agents were from 3- to 12-fold, in good agreement with previous mRNA analyses. When MATa cells were arrested in G1 with alpha-factor, RAD54 was still inducible after DNA damage, indicating that the observed induction is independent of the cell cycle. Using a yeast vector containing the EcoRI structural gene fused to the GAL1 promoter, we showed that double-strand breaks alone are sufficient in vivo for induction of RAD54.

  7. Piezoelectric, impedance, electric modulus and AC conductivity studies on (Bi0.5Na0.50.95Ba0.05TiO3 ceramic

    Directory of Open Access Journals (Sweden)

    Ansu K. Roy

    2013-06-01

    Full Text Available Lead-free piezoelectric perovskite ceramic (Bi0.5Na0.50.95Ba0.05TiO3 (BNT-BT0.05, prepared by conventional high temperature solid state reaction technique at 1160 °C/3h in air atmosphere, is investigated by impedance and modulus spectroscopy in a temperature range 35–400 °C, over a frequency range 100 Hz–1 MHz. The crystal structure, microstructure, and piezoelectric properties as well as the AC conductivity of the sample were studied. Powder X-ray diffraction pattern derived from the resulting data at the room temperature subjected to Rietveld refinements and Williamson-Hall plot analysis confirmed the formation of phase pure compound with monoclinic unit cells having a crystallite-size ~33.8 nm. Observed SEM micrograph showed a uniform distribution of grains inside the sample having an average grain size ~3 mm. Longitudinal piezoelectric charge coefficient of the sample poled under a DC electric field of ~ 2.5 kV/mm at 80 °C in a silicone oil bath was found to be equal to 95 pC/N. The frequency and temperature dependent electrical data analysed in the framework of AC conductivity, complex impedance as well as electric modulus formalisms showed negative temperature coefficient of resistance (NTCR character of the material and the dielectric relaxation in the material to be of non-Debye type. Double power law for the frequency-dependence of AC conductivity and Jump Relaxation Model (JRM were found to explain successfully the mechanism of charge transport in BNT-BT0.05.

  8. Nuclear localization of Rad51B is independent of BRCA2

    Energy Technology Data Exchange (ETDEWEB)

    Miller, K A; Hinz, J M; Yamada, A; Thompson, L H; Albala, J S

    2005-06-28

    Human Rad51 is critical for the maintenance of genome stability through its role in the repair of DNA double-strand breaks. Rad51B (Rad51L1/hRec2) is one of the five known paralogs of human Rad51 found in a multi-protein complex with three other Rad51 paralogs, Rad51C, Rad51D and Xrcc2. Examination of EGFP-Rad51B fusion protein in HeLa S3 cells and immunofluorescence in several human cell lines confirms the nuclear localization of Rad51B. This is the first report to detail putative interactions of a Rad51 paralog protein with BRCA2. Utilization of a BRCA2 mutant cell line, CAPAN-1 suggests that Rad51B localizes to the nucleus independent of BRCA2. Although both Rad51B and BRCA2 are clearly involved in the homologous recombinational repair pathway, Rad51B and BRCA2 do not appear to associate directly. Furthermore, mutations in the KKLK motif of Rad51B, amino acid residues 4-7, mislocalizes Rad51B to the cytoplasm suggesting that this is the nuclear localization signal for the Rad51B protein. Examination of wild-type EGFP-Rad51B fusion protein in mammalian cells deficient in Rad51C showed that Rad51B localizes to the nucleus independent of Rad51C; further suggesting that Rad51B, like Rad51C, contains its own nuclear localization signal.

  9. Inter-observer variability within BI-RADS and RANZCR mammographic density assessment schemes

    Science.gov (United States)

    Damases, Christine N.; Mello-Thoms, Claudia; McEntee, Mark F.

    2016-03-01

    This study compares variability associated with two visual mammographic density (MD) assessment methods using two separate samples of radiologists. The image test-set comprised of images obtained from 20 women (age 42-89 years). The images were assessed for their MD by twenty American Board of Radiology (ABR) examiners and twenty-six radiologists registered with the Royal Australian and New Zealand College of Radiologists (RANZCR). Images were assessed using the same technology and conditions, however the ABR radiologists used the BI-RADS and the RANZCR radiologists used the RANZCR breast density synoptic. Both scales use a 4-point assessment. The images were then grouped as low- and high-density; low including BIRADS 1 and 2 or RANZCR 1 and 2 and high including BI-RADS 3 and 4 or RANZCR 3 and 4. Four-point BI-RADS and RANZCR showed no or negligible correlation (ρ=-0.029 p<0.859). The average inter-observer agreement on the BI-RADS scale had a Kappa of 0.565; [95% CI = 0.519 - 0.610], and ranged between 0.328-0.669 while the inter-observer agreement using the RANZCR scale had a Kappa of 0.360; [95% CI = 0.308 - 0.412] and a range of 0.078-0.499. Our findings show a wider range of inter-observer variability among RANZCR registered radiologists than the ABR examiners.

  10. A chemical compound that stimulates the human homologous recombination protein RAD51.

    Science.gov (United States)

    Jayathilaka, Krishanthi; Sheridan, Sean D; Bold, Tyler D; Bochenska, Katarzyna; Logan, Hillary L; Weichselbaum, Ralph R; Bishop, Douglas K; Connell, Philip P

    2008-10-14

    RAD51 and other members of the RecA family of strand exchange proteins assemble on ssDNA to form presynaptic filaments, which carry out the central steps of homologous recombination. A microplate-based assay was developed for high-throughput measurement of hRAD51 filament formation on ssDNA. With this method, a 10,000 compound library was screened, leading to the identification of a small molecule (RS-1) that enhances hRAD51 binding in a wide range of biochemical conditions. Salt titration experiments showed that RS-1 can enhance filament stability. Ultrastructural analysis of filaments formed on ssDNA showed that RS-1 can increase both protein-DNA complex lengths and the pitch of helical filament turns. RS-1 stimulated hRAD51-mediated homologous strand assimilation (D-loop) activity by at least 5- to 11-fold, depending on the condition. This D-loop stimulation occurred even in the presence of Ca(2+) or adenylyl-imidodiphosphate, indicating that the mechanism of stimulation was distinct from that conferred by Ca(2+) and/or inhibition of ATPase. No D-loop activity was observed in the absence of a nucleotide triphosphate cofactor, indicating that the compound does not substitute for this requirement. These results indicate that RS-1 enhances the homologous recombination activity of hRAD51 by promoting the formation of active presynaptic filaments. Cell survival assays in normal neonatal human dermal fibroblasts demonstrated that RS-1 promotes a dose-dependent resistance to the cross-linking chemotherapeutic drug cisplatin. Given that RAD51-dependent recombination is a major determinant of cisplatin resistance, RS-1 seems to function in vivo to stimulate homologous recombination repair proficiency. RS-1 has many potential applications in both research and medical settings.

  11. Synthesis and characterization particles of Ba{sub 0,50}Sr{sub 0,50}Co{sub 0,80}Fe{sub 0,20}O{sub 3} obtained by the citrate-EDTA technique; Sintese e caracterizacao de particulados de Ba{sub 0,50}Sr{sub 0,50}Co{sub 0,80}Fe{sub 0,20}O{sub 3} obtidos pela tecnica dos citratos-EDTA

    Energy Technology Data Exchange (ETDEWEB)

    Bonturim, E.; Vargas, R.A.; Andreoli, M.; Seo, E.S.M., E-mail: ebonturim@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (CCTM/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencia e Tecnologia de Materiais

    2010-07-01

    The Ba{sub (1-x)}Sr{sub (x)}Co{sub (1-y)}Fe{sub (y)}O{sub (3)} (BSCF) has been studied as a cathode material for Intermediate Temperature Solid Oxide Fuel Cell, due to its better ion and electron conduction. This work aims to study the synthesis of the compound obtained from the citrate-EDTA technique. Thermogravimetric analysis indicated the formation of the compound above 800 deg C. The materials calcined at temperatures of 700, 800 and 900 deg C for 5 h showed cubic pseudo-perovskite structure, according to the literature. By analysis of X-ray fluorescence were obtained powders with nominal chemical composition in the temperature range studied. The micrographs obtained by SEM and particle size distribution analysis showed the formation of particle with diameters below 1 micron. (author)

  12. Regulation of Rad51-Mediated Homologous Recombination by BRCA2, DSS1 and RAD52

    DEFF Research Database (Denmark)

    Rants, Louise Olthaver Juhl

    Homologous recombination (HR) provides a mechanism to restore integrity and maintain stability of the genetic material. HR is a major pathway for repair of DNA double-strand breaks (DSB), recovery of broken replication forks and generation of meiotic crossovers. The defining step in HR...... in governing the activity of Rad51 and to learn how other recombination-associated proteins such as DSS1 and RAD52 contribute to its regulation. We use the yeast-like fungus Ustilago maydis and the avian DT40 cell line as experimental systems since both have a well-conserved BRCA2-based recombinational repair...

  13. TODRA, a lncRNA at the RAD51 Locus, Is Oppositely Regulated to RAD51, and Enhances RAD51-Dependent DSB (Double Strand Break) Repair

    Science.gov (United States)

    Renbaum, Paul; Zeligson, Sharon; Eini, Lital; Bashari, Dana; Smith, Yoav; Lahad, Amnon; Goldberg, Michal; Ginsberg, Doron; Levy-Lahad, Ephrat

    2015-01-01

    Expression of RAD51, a crucial player in homologous recombination (HR) and DNA double-strand break (DSB) repair, is dysregulated in human tumors, and can contribute to genomic instability and tumor progression. To further understand RAD51 regulation we functionally characterized a long non-coding (lnc) RNA, dubbed TODRA (Transcribed in the Opposite Direction of RAD51), transcribed 69bp upstream to RAD51, in the opposite direction. We demonstrate that TODRA is an expressed transcript and that the RAD51 promoter region is bidirectional, supporting TODRA expression (7-fold higher than RAD51 in this assay, p = 0.003). TODRA overexpression in HeLa cells induced expression of TPIP, a member of the TPTE family which includes PTEN. Similar to PTEN, we found that TPIP co-activates E2F1 induction of RAD51. Analysis of E2F1's effect on the bidirectional promoter showed that E2F1 binding to the same site that promotes RAD51 expression, results in downregulation of TODRA. Moreover, TODRA overexpression induces HR in a RAD51-dependent DSB repair assay, and increases formation of DNA damage-induced RAD51-positive foci. Importantly, gene expression in breast tumors supports our finding that E2F1 oppositely regulates RAD51 and TODRA: increased RAD51 expression, which is associated with an aggressive tumor phenotype (e.g. negative correlation with positive ER (r = -0.22, p = 0.02) and positive PR status (r = -0.27, p<0.001); positive correlation with ki67 status (r = 0.36, p = 0.005) and HER2 amplification (r = 0.41, p = 0.001)), correlates as expected with lower TODRA and higher E2F1 expression. However, although E2F1 induction resulted in TPIP downregulation in cell lines, we find that TPIP expression in tumors is not reduced despite higher E2F1 expression, perhaps contributing to increased RAD51 expression. Our results identify TPIP as a novel E2F1 co-activator, suggest a similar role for other TPTEs, and indicate that the TODRA lncRNA affects RAD51 dysregulation and RAD51

  14. Environmental radon with RAD7 detector; Radon ambiental con detector RAD7

    Energy Technology Data Exchange (ETDEWEB)

    Lopez M, A.; Balcazar, M. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Fernandez G, I. M.; Capote F, E., E-mail: arturo.lopez@inin.gob.mx [Centro de Proteccion e Higiene de las Radiaciones, Carretera La Victoria II Km 2.5 e/ Monumental y Final, Guanabacoa, La Habana (Cuba)

    2016-09-15

    Experimental results of the radon detection with the equipment RAD7 are presented. The use of a solid state detector placed in a semi-spherical chamber with an electric field allows a high sensitivity of 0.4 cpm/P Ci/l. Radon detection is achieved by the spectroscopy of its decay products. In accordance with a table of errors for various ranges of counts and radon concentrations, reported by the manufacturer, an equation was obtained that allows establishing operation criteria of the equipment. For radon detection at ambient concentrations as low as 30 Bq m{sup -3}, is shown that short counts of 10 minutes are good enough to make decisions on radiation protection matter. In places where concentrations are close to 200 Bq m{sup -3}, counting intervals of the order of 0.5 hours will have an acceptable counting error of the order of 20%. The determination of radon in soil was, according to the expected, on the order of 10 kBq m{sup -3}, and was found that even with the recommended counting times of 5 minutes, there is a risk of increased humidity inside the detector above 20% Rh, with associated reduction of detection efficiency, if the desiccant is not used properly. The equipment was subjected to a radon exposure in air of 13, 373 Bq m{sup -3} ± 3.7%, contained within a controlled chamber, with a variation in temperature of (19-21) degrees Celsius and in the relative humidity of (5-7) %, the good stability of the chamber allows to propose calibration processes of these equipment s by assessing the concentration by means of a Ge (Hp) detector. (Author)

  15. Microstructural characterisation of near- α titanium alloy Ti-6Al-4Sn-4Zr-0.70Nb-0.50Mo-0.40Si

    Science.gov (United States)

    Ramachandra, C.; Singh, A. K.; Sarma, G. M. K.

    1993-06-01

    Microstructural stability in the near-α titanium alloy (alloy 834) containing Ti-6Al-4Sn-4Zr-0.70Nb-0.50Mo-0.40Si (in weight percent), in the β and (α + β) solution-treated and quenched conditions, has been investigated. The β transus for this alloy is approximately 1333 K. Solution treatment in the β phase field at 1353 K followed by quenching in water at room temperature resulted in the formation of α' martensite platelets with high dislocation density and stacking faults. Thin films of β are found to be sandwiched between interface phases, which, in turn, are sandwiched at the interplatelet boundaries of lath martensite. The interface phase is a subject of much controversy in the literature. Solution treatment at 1303 K in the (α + β) phase field followed by quenching in water at room temperature resulted in the near-equiaxed primary α and transformed β. Both the β and (α + β) solution-treated specimens were aged in the temperature range of 873 to 973 K. While aging the —treated specimen at 973 K, (α + β)-treated specimen, even at a lower temperature of 873 K for 24 hours, caused precipitation of suicides predominantly at the interplatelet boundaries of martensite laths. Electron diffraction analysis confirmed them to be hexagonal suicide S2 with a = 0.702 nm and c = 0.368 nm. The above difference in the precipitation could be attributed to the partitioning of a higher amount of β - stabilizing elements as well as silicide-forming elements to the transformed β in the (α + β) solution-treated condition. However, ordering of the α' phase was observed under all of the aging conditions studied. The ordered domains were due to the longer aging times, which cause local increases in the level of the α-stabilizing elements.

  16. Analysis list: Rad51 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Rad51 Blood,Gonad + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Rad51.1.tsv http:...//dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Rad51.5.tsv http://dbarchive.biosciencedbc.jp/k...yushu-u/mm9/target/Rad51.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Rad51.Blood.tsv,http://d...barchive.biosciencedbc.jp/kyushu-u/mm9/colo/Rad51.Gonad.tsv http://dbarchive.bios...ciencedbc.jp/kyushu-u/mm9/colo/Blood.gml,http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Gonad.gml ...

  17. Magnetic and electronic transitions in charge-ordered Nd 0.50Ca 0.47Ba 0.03MnO 3 manganite

    Science.gov (United States)

    Mavani, K. R.; Paulose, P. L.

    The ABO 3 type charge-ordered antiferromagnetic Nd 0.50Ca 0.50MnO 3 (NCMO) manganite is doped at A-site by 3%of Ba 2+ for Ca 2+. The resulting system, Nd 0.50Ca 0.47Ba 0.03MnO 3 (NCBMO), is studied for the effects of Ba doping on the magnetic and electronic properties. On application of magnetic field to NCBMO, strongly correlated successive sharp metamagnetic and electronic transitions are observed from antiferromagnetic-insulating to ferromagnetic-metallic state at 2.5 K. The critical magnetic field ( Hc) required for metamagnetism is found to reduce drastically from 15 T for undoped NCMO to 3 T for NCBMO. On increasing the temperature, the Hc of NCBMO passes through a minimum. This behavior of Hc of NCBMO contrasts to that of NCMO. The results are discussed in context of A-site cation disorder and size.

  18. RadCat 2.0 User Guide.

    Energy Technology Data Exchange (ETDEWEB)

    Osborn, Douglas.; Weiner, Ruth F.; Mills, George Scott; Hamp, Steve C.; O' Donnell, Brandon, M.; Orcutt, David J.; Heames, Terence J.; Hinojosa, Daniel

    2005-01-01

    This document provides a detailed discussion and a guide for the use of the RadCat 2.0 Graphical User Interface input file generator for the RADTRAN 5.5 code. The differences between RadCat 2.0 and RadCat 1.0 can be attributed to the differences between RADTRAN 5 and RADTRAN 5.5 as well as clarification for some of the input parameters. 3

  19. Variation in the RAD51 gene and familial breast cancer

    Science.gov (United States)

    Lose, Felicity; Lovelock, Paul; Chenevix-Trench, Georgia; Mann, Graham J; Pupo, Gulietta M; Spurdle, Amanda B

    2006-01-01

    Introduction Human RAD51 is a homologue of the Escherichia coli RecA protein and is known to function in recombinational repair of double-stranded DNA breaks. Mutations in the lower eukaryotic homologues of RAD51 result in a deficiency in the repair of double-stranded DNA breaks. Loss of RAD51 function would therefore be expected to result in an elevated mutation rate, leading to accumulation of DNA damage and, hence, to increased cancer risk. RAD51 interacts directly or indirectly with a number of proteins implicated in breast cancer, such as BRCA1 and BRCA2. Similar to BRCA1 mice, RAD51-/- mice are embryonic lethal. The RAD51 gene region has been shown to exhibit loss of heterozygosity in breast tumours, and deregulated RAD51 expression in breast cancer patients has also been reported. Few studies have investigated the role of coding region variation in the RAD51 gene in familial breast cancer, with only one coding region variant – exon 6 c.449G>A (p.R150Q) – reported to date. Methods All nine coding exons of the RAD51 gene were analysed for variation in 46 well-characterised, BRCA1/2-negative breast cancer families using denaturing high-performance liquid chromatography. Genotyping of the exon 6 p.R150Q variant was performed in an additional 66 families. Additionally, lymphoblastoid cell lines from breast cancer patients were subjected to single nucleotide primer extension analysis to assess RAD51 expression. Results No coding region variation was found, and all intronic variation detected was either found in unaffected controls or was unlikely to have functional consequences. Single nucleotide primer extension analysis did not reveal any allele-specific changes in RAD51 expression in all lymphoblastoid cell lines tested. Conclusion Our study indicates that RAD51 is not a major familial breast cancer predisposition gene. PMID:16762046

  20. Rad51 activates polyomavirus JC early transcription.

    Directory of Open Access Journals (Sweden)

    Martyn K White

    Full Text Available The human neurotropic polyomavirus JC (JCV causes the fatal CNS demyelinating disease progressive multifocal leukoencephalopathy (PML. JCV infection is very common and after primary infection, the virus is able to persist in an asymptomatic state. Rarely, and usually only under conditions of immune impairment, JCV re-emerges to actively replicate in the astrocytes and oligodendrocytes of the brain causing PML. The regulatory events involved in the reactivation of active viral replication in PML are not well understood but previous studies have implicated the transcription factor NF-κB acting at a well-characterized site in the JCV noncoding control region (NCCR. NF-κB in turn is regulated in a number of ways including activation by cytokines such as TNF-α, interactions with other transcription factors and epigenetic events involving protein acetylation--all of which can regulate the transcriptional activity of JCV. Active JCV infection is marked by the occurrence of rapid and extensive DNA damage in the host cell and the induction of the expression of cellular proteins involved in DNA repair including Rad51, a major component of the homologous recombination-directed double-strand break DNA repair machinery. Here we show that increased Rad51 expression activates the JCV early promoter. This activation is co-operative with the stimulation caused by NF-κB p65, abrogated by mutation of the NF-κB binding site or siRNA to NFκB p65 and enhanced by the histone deacetylase inhibitor sodium butyrate. These data indicate that the induction of Rad51 resulting from infection with JCV acts through NF-κB via its binding site to stimulate JCV early transcription. We suggest that this provides a novel positive feedback mechanism to enhance viral gene expression during the early stage of JCV infection.

  1. Rad52 SUMOylation affects the efficiency of the DNA repair

    DEFF Research Database (Denmark)

    Altmannova, Veronika; Eckert-Boulet, Nadine; Arneric, Milica

    2010-01-01

    Homologous recombination (HR) plays a vital role in DNA metabolic processes including meiosis, DNA repair, DNA replication and rDNA homeostasis. HR defects can lead to pathological outcomes, including genetic diseases and cancer. Recent studies suggest that the post-translational modification...... recombination mediator protein Rad52. Interestingly, Rad52 SUMOylation is enhanced by single-stranded DNA, and we show that SUMOylation of Rad52 also inhibits its DNA binding and annealing activities. The biochemical effects of SUMO modification in vitro are accompanied by a shorter duration of spontaneous Rad...... of recombination and DNA repair....

  2. Roles of C-Terminal Region of Yeast and Human Rad52 in Rad51-Nucleoprotein Filament Formation and ssDNA Annealing.

    Directory of Open Access Journals (Sweden)

    Nilesh V Khade

    Full Text Available Yeast Rad52 (yRad52 has two important functions at homologous DNA recombination (HR; annealing complementary single-strand DNA (ssDNA molecules and recruiting Rad51 recombinase onto ssDNA (recombination mediator activity. Its human homolog (hRAD52 has a lesser role in HR, and apparently lacks mediator activity. Here we show that yRad52 can load human Rad51 (hRAD51 onto ssDNA complexed with yeast RPA in vitro. This is biochemically equivalent to mediator activity because it depends on the C-terminal Rad51-binding region of yRad52 and on functional Rad52-RPA interaction. It has been reported that the N-terminal two thirds of both yRad52 and hRAD52 is essential for binding to and annealing ssDNA. Although a second DNA binding region has been found in the C-terminal region of yRad52, its role in ssDNA annealing is not clear. In this paper, we also show that the C-terminal region of yRad52, but not of hRAD52, is involved in ssDNA annealing. This suggests that the second DNA binding site is required for the efficient ssDNA annealing by yRad52. We propose an updated model of Rad52-mediated ssDNA annealing.

  3. Two DNA repair and recombination genes in Saccharomyces cerevisiae, RAD52 and RAD54, are induced during meiosis

    Energy Technology Data Exchange (ETDEWEB)

    Cole, G.M.; Mortimer, R.K. (Univ. of California, Berkeley (United States)); Schild, D. (Lawrence Berkeley Lab., CA (United States))

    1989-07-01

    The DNA repair and recombination genes of Saccharomyces cerevisiae, RAD52 and RAD54, were transcriptionally induced approximately 10- to 15-fold in sporulating MATa/{alpha} cells. Congenic MATa/a cells, which did not sporulate, did not show similar increases. Assays of {beta}-galactosidase activity in strains harboring either a RAD52- or RAD54-lacZ gene fusion indicated that this induction occurred at a time concomitant with a commitment to meiotic recombination, as measured by prototroph formation from his1 heteroalleles.

  4. Interrogation of the protein-protein interactions between human BRCA2 BRC repeats and RAD51 reveals atomistic determinants of affinity.

    Directory of Open Access Journals (Sweden)

    Daniel J Cole

    2011-07-01

    Full Text Available The breast cancer suppressor BRCA2 controls the recombinase RAD51 in the reactions that mediate homologous DNA recombination, an essential cellular process required for the error-free repair of DNA double-stranded breaks. The primary mode of interaction between BRCA2 and RAD51 is through the BRC repeats, which are ∼35 residue peptide motifs that interact directly with RAD51 in vitro. Human BRCA2, like its mammalian orthologues, contains 8 BRC repeats whose sequence and spacing are evolutionarily conserved. Despite their sequence conservation, there is evidence that the different human BRC repeats have distinct capacities to bind RAD51. A previously published crystal structure reports the structural basis of the interaction between human BRC4 and the catalytic core domain of RAD51. However, no structural information is available regarding the binding of the remaining seven BRC repeats to RAD51, nor is it known why the BRC repeats show marked variation in binding affinity to RAD51 despite only subtle sequence variation. To address these issues, we have performed fluorescence polarisation assays to indirectly measure relative binding affinity, and applied computational simulations to interrogate the behaviour of the eight human BRC-RAD51 complexes, as well as a suite of BRC cancer-associated mutations. Our computational approaches encompass a range of techniques designed to link sequence variation with binding free energy. They include MM-PBSA and thermodynamic integration, which are based on classical force fields, and a recently developed approach to computing binding free energies from large-scale quantum mechanical first principles calculations with the linear-scaling density functional code onetep. Our findings not only reveal how sequence variation in the BRC repeats directly affects affinity with RAD51 and provide significant new insights into the control of RAD51 by human BRCA2, but also exemplify a palette of computational and

  5. Astaxanthin down-regulates Rad51 expression via inactivation of AKT kinase to enhance mitomycin C-induced cytotoxicity in human non-small cell lung cancer cells.

    Science.gov (United States)

    Ko, Jen-Chung; Chen, Jyh-Cheng; Wang, Tai-Jing; Zheng, Hao-Yu; Chen, Wen-Ching; Chang, Po-Yuan; Lin, Yun-Wei

    2016-04-01

    Astaxanthin has been demonstrated to exhibit a wide range of beneficial effects, including anti-inflammatory and anti-cancer properties. However, the molecular mechanism of astaxanthin-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells has not been identified. Rad51 plays a central role in homologous recombination, and studies show that chemo-resistant carcinomas exhibit high levels of Rad51 expression. In this study, astaxanthin treatment inhibited cell viability and proliferation of two NSCLC cells, A549 and H1703. Astaxanthin treatment (2.5-20 μM) decreased Rad51 expression and phospho-AKT(Ser473) protein level in a time and dose-dependent manner. Furthermore, expression of constitutively active AKT (AKT-CA) vector rescued the decreased Rad51 mRNA and protein levels in astaxanthin-treated NSCLC cells. Combined treatment with phosphatidylinositol 3-kinase (PI3K) inhibitors (LY294002 or wortmannin) further decreased the Rad51 expression in astaxanthin-exposed A549 and H1703 cells. Knockdown of Rad51 expression by transfection with si-Rad51 RNA or cotreatment with LY294002 further enhanced the cytotoxicity and cell growth inhibition of astaxanthin. Additionally, mitomycin C (MMC) as an anti-tumor antibiotic is widely used in clinical NSCLC chemotherapy. Combination of MMC and astaxanthin synergistically resulted in cytotoxicity and cell growth inhibition in NSCLC cells, accompanied with reduced phospho-AKT(Ser473) level and Rad51 expression. Overexpression of AKT-CA or Flag-tagged Rad51 reversed the astaxanthin and MMC-induced synergistic cytotoxicity. In contrast, pretreatment with LY294002 further decreased the cell viability in astaxanthin and MMC co-treated cells. In conclusion, astaxanthin enhances MMC-induced cytotoxicity by decreasing Rad51 expression and AKT activation. These findings may provide rationale to combine astaxanthin with MMC for the treatment of NSCLC.

  6. Reappearance from Obscurity: Mammalian Rad52 in Homologous Recombination

    Directory of Open Access Journals (Sweden)

    Kritika Hanamshet

    2016-09-01

    Full Text Available Homologous recombination (HR plays an important role in maintaining genomic integrity. It is responsible for repair of the most harmful DNA lesions, DNA double-strand breaks and inter-strand DNA cross-links. HR function is also essential for proper segregation of homologous chromosomes in meiosis, maintenance of telomeres, and resolving stalled replication forks. Defects in HR often lead to genetic diseases and cancer. Rad52 is one of the key HR proteins, which is evolutionarily conserved from yeast to humans. In yeast, Rad52 is important for most HR events; Rad52 mutations disrupt repair of DNA double-strand breaks and targeted DNA integration. Surprisingly, in mammals, Rad52 knockouts showed no significant DNA repair or recombination phenotype. However, recent work demonstrated that mutations in human RAD52 are synthetically lethal with mutations in several other HR proteins including BRCA1 and BRCA2. These new findings indicate an important backup role for Rad52, which complements the main HR mechanism in mammals. In this review, we focus on the Rad52 activities and functions in HR and the possibility of using human RAD52 as therapeutic target in BRCA1 and BRCA2-deficient familial breast cancer and ovarian cancer.

  7. RadNet Air Data From Salt Lake City, UT

    Science.gov (United States)

    This page presents radiation air monitoring and air filter analysis data for Salt Lake City, UT from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  8. Study on Performance of Empore~(TM) Technetium Rad Disks

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    EmporeTM Technetium Rad disks produced by 3M Company contain GD-1 sorbent loaded on particles that are embedded in an inert PTFE matrix. In this study, several experiments have been accomplished to evaluate the performance of EmporeTM Technetium Rad disks.

  9. Nap1 stimulates homologous recombination by RAD51 and RAD54 in higher-ordered chromatin containing histone H1.

    Science.gov (United States)

    Machida, Shinichi; Takaku, Motoki; Ikura, Masae; Sun, Jiying; Suzuki, Hidekazu; Kobayashi, Wataru; Kinomura, Aiko; Osakabe, Akihisa; Tachiwana, Hiroaki; Horikoshi, Yasunori; Fukuto, Atsuhiko; Matsuda, Ryo; Ura, Kiyoe; Tashiro, Satoshi; Ikura, Tsuyoshi; Kurumizaka, Hitoshi

    2014-05-06

    Homologous recombination plays essential roles in mitotic DNA double strand break (DSB) repair and meiotic genetic recombination. In eukaryotes, RAD51 promotes the central homologous-pairing step during homologous recombination, but is not sufficient to overcome the reaction barrier imposed by nucleosomes. RAD54, a member of the ATP-dependent nucleosome remodeling factor family, is required to promote the RAD51-mediated homologous pairing in nucleosomal DNA. In higher eukaryotes, most nucleosomes form higher-ordered chromatin containing the linker histone H1. However, the mechanism by which RAD51/RAD54-mediated homologous pairing occurs in higher-ordered chromatin has not been elucidated. In this study, we found that a histone chaperone, Nap1, accumulates on DSB sites in human cells, and DSB repair is substantially decreased in Nap1-knockdown cells. We determined that Nap1 binds to RAD54, enhances the RAD54-mediated nucleosome remodeling by evicting histone H1, and eventually stimulates the RAD51-mediated homologous pairing in higher-ordered chromatin containing histone H1.

  10. A Polar and Nucleotide-Dependent Mechanism of Action for RAD51 Paralogs in RAD51 Filament Remodeling.

    Science.gov (United States)

    Taylor, Martin R G; Špírek, Mário; Jian Ma, Chu; Carzaniga, Raffaella; Takaki, Tohru; Collinson, Lucy M; Greene, Eric C; Krejci, Lumir; Boulton, Simon J

    2016-12-01

    Central to homologous recombination in eukaryotes is the RAD51 recombinase, which forms helical nucleoprotein filaments on single-stranded DNA (ssDNA) and catalyzes strand invasion with homologous duplex DNA. Various regulatory proteins assist this reaction including the RAD51 paralogs. We recently discovered that a RAD51 paralog complex from C. elegans, RFS-1/RIP-1, functions predominantly downstream of filament assembly by binding and remodeling RAD-51-ssDNA filaments to a conformation more proficient for strand exchange. Here, we demonstrate that RFS-1/RIP-1 acts by shutting down RAD-51 dissociation from ssDNA. Using stopped-flow experiments, we show that RFS-1/RIP-1 confers this dramatic stabilization by capping the 5' end of RAD-51-ssDNA filaments. Filament end capping propagates a stabilizing effect with a 5'→3' polarity approximately 40 nucleotides along individual filaments. Finally, we discover that filament capping and stabilization are dependent on nucleotide binding, but not hydrolysis by RFS-1/RIP-1. These data define the mechanism of RAD51 filament remodeling by RAD51 paralogs. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Avaliação das propriedades do Ba0,50Sr0,50Co0,80Fe0,20O3-d para células a combustível de óxido sólido de temperatura intermediária obtido pelo método citratos-EDTA Evaluation of the properties of Ba0,50Sr0.50Co0.80Fe0.20O3-d obtained by the citrate-EDTA method for intermediate temperature solid oxide fuel cell

    OpenAIRE

    E. Bonturim; VARGAS, R.A.; Andreoli,M.; SEO, E.S.M.

    2013-01-01

    Ba0,50Sr0,50Co0,80Fe0,20O3-d (BSCF) apresenta propriedades físicas, químicas e microestruturais adequadas para compor o cátodo de uma célula a combustível de óxido sólido de temperatura intermediária (ITSOFC). Este trabalho tem por objetivo a síntese e a caracterização do BSCF obtido pelo método dos citrados-EDTA. Os resultados obtidos por difração de raios X (DRX) indicaram fases secundárias para o material calcinado a 700 e 800 ºC e fase única com estrutura cristalina do tipo perovskita par...

  12. Determination of radon concentration in water using RAD7 with RAD H{sub 2}O accessories

    Energy Technology Data Exchange (ETDEWEB)

    Malik, M. F. I. [Science and Engineering Research Centre (SERC), Universiti Sains Malaysia, Seri Ampangan Nibong Tebal 14300 Penang (Malaysia); Rabaiee, N. A.; Jaafar, M. S. [School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia)

    2015-04-24

    In the last decade, the radon issue has become one of the major problems of radiation protection. Radon exposure occurs when using water for showering, washing dishes, cooking and drinking water. RAD7 and Rad H20 accessories were used in order to measure radon concentration in water sample. In this study, four types of water were concerns which are reverse osmosis (drinking water), mineral water, tap water and well water. Reverse osmosis (drinking water) and mineral water were bought from the nearest supermarket while tap water and well water were taken from selected areas of Pulau Pinang and Kedah. Total 20 samples were taken with 5 samples for each type of water. The measured radon concentration ranged from 2.9±2.9 to 79.5±17 pCi/L, 2.9±2.9 to 67.8±16 pCi/L, 15.97±7 to 144.25±24 pCi/L and 374.89±37 to 6409.03±130 pCi/L in reverse osmosis (drinking water), mineral water, tap water and well water. Well water has the highest radon compared to others. It was due to their geological element such as granite. Results for all types of water are presented and compared with maximum contamination limit (MCL) recommended by United State Environmental Protection Agency (USEPA) which is 300pCi/L. Reverse osmosis water, mineral water and tap water were fall below MCL. However, well water was exceeded maximum level that was recommended. Thus, these findings were suggested that an action should be taken to reduce radon concentration level in well water as well as reduce a health risk towards the public.

  13. Aktsiisiseaduse muudatused 2006. aastal : aktsiisimäärad / Urmas Koidu

    Index Scriptorium Estoniae

    Koidu, Urmas

    2006-01-01

    2006. aastal jõustunud alkoholi-, tubaka- ja kütuseaktsiisi seaduse muudatustest. Lisatud tabelid: alkoholi aktsiisimäärad Eestis 2006-2008 ja ELi aktsiisi alammäärad (krooni); tubakatoodete aktsiisimäärad Eestis 2006-2008 ja ELi aktsiisi alammäärad; mootorikütuse aktsiisimäärad Eestis ja ELi alammäärad; kütteainete ja elektrienergia aktsiisimäärad Eestis ja ELi alammäärad

  14. Aktsiisiseaduse muudatused 2006. aastal : aktsiisimäärad / Urmas Koidu

    Index Scriptorium Estoniae

    Koidu, Urmas

    2006-01-01

    2006. aastal jõustunud alkoholi-, tubaka- ja kütuseaktsiisi seaduse muudatustest. Lisatud tabelid: alkoholi aktsiisimäärad Eestis 2006-2008 ja ELi aktsiisi alammäärad (krooni); tubakatoodete aktsiisimäärad Eestis 2006-2008 ja ELi aktsiisi alammäärad; mootorikütuse aktsiisimäärad Eestis ja ELi alammäärad; kütteainete ja elektrienergia aktsiisimäärad Eestis ja ELi alammäärad

  15. Roles of the checkpoint sensor clamp Rad9-Rad1-Hus1 (911)-complex and the clamp loaders Rad17-RFC and Ctf18-RFC in Schizosaccharomyces pombe telomere maintenance.

    Science.gov (United States)

    Khair, Lyne; Chang, Ya-Ting; Subramanian, Lakxmi; Russell, Paul; Nakamura, Toru M

    2010-06-01

    While telomeres must provide mechanisms to prevent DNA repair and DNA damage checkpoint factors from fusing chromosome ends and causing permanent cell cycle arrest, these factors associate with functional telomeres and play critical roles in the maintenance of telomeres. Previous studies have established that Tel1 (ATM) and Rad3 (ATR) kinases play redundant but essential roles for telomere maintenance in fission yeast. In addition, the Rad9-Rad1-Hus1 (911) and Rad17-RFC complexes work downstream of Rad3 (ATR) in fission yeast telomere maintenance. Here, we investigated how 911, Rad17-RFC and another RFC-like complex Ctf18-RFC contribute to telomere maintenance in fission yeast cells lacking Tel1 and carrying a novel hypomorphic allele of rad3 (DBD-rad3), generated by the fusion between the DNA binding domain (DBD) of the fission yeast telomere capping protein Pot1 and Rad3. Our investigations have uncovered a surprising redundancy for Rad9 and Hus1 in allowing Rad1 to contribute to telomere maintenance in DBD-rad3 tel1 cells. In addition, we found that Rad17-RFC and Ctf18-RFC carry out redundant telomere maintenance functions in DBD-rad3 tel1 cells. Since checkpoint sensor proteins are highly conserved, genetic redundancies uncovered here may be relevant to telomere maintenance and detection of DNA damage in other eukaryotes.

  16. The SRS2 suppressor of rad6 mutations of Saccharomyces cerevisiae acts by channeling DNA lesions into the RAD52 DNA repair pathway

    Energy Technology Data Exchange (ETDEWEB)

    Schiestl, R.H.; Prakash, S.; Prakash, L. (Univ. of Rochester School of Medicine, NY (USA))

    1990-04-01

    rad6 mutants of Saccharomyces cerevisiae are defective in the repair of damaged DNA, DNA damage induced mutagenesis, and sporulation. In order to identify genes that can substitute for RAD6 function, the authors have isolated genomic suppressors of the UV sensitivity of rad6 deletion (rad6{Delta}) mutations and show that they also suppress the {gamma}-ray sensitivity but not the UV mutagenesis or sporulation defects of rad6. The suppressors show semidominance for suppression of UV sensitivity and dominance for suppression of {gamma}-ray sensitivity. The six suppressor mutations they isolated are all alleles of the same locus and are also allelic to a previously described suppressor of the rad6-1 nonsense mutation, SRS2. They show that suppression of rad6{Delta} is dependent on the RAD52 recombinational repair pathway since suppression is not observed in the rad6{Delta} SRS2 strain containing an additional mutation in either the RAD51, RAD52, RAD54, RAD55 or RAD57 genes. Possible mechanisms by which SRS2 may channel unrepaired DNA lesions into the RAD52 DNA repair pathway are discussed.

  17. Avaliação das propriedades do Ba0,50Sr0,50Co0,80Fe0,20O3-d para células a combustível de óxido sólido de temperatura intermediária obtido pelo método citratos-EDTA Evaluation of the properties of Ba0,50Sr0.50Co0.80Fe0.20O3-d obtained by the citrate-EDTA method for intermediate temperature solid oxide fuel cell

    Directory of Open Access Journals (Sweden)

    E. Bonturim

    2013-03-01

    Full Text Available Ba0,50Sr0,50Co0,80Fe0,20O3-d (BSCF apresenta propriedades físicas, químicas e microestruturais adequadas para compor o cátodo de uma célula a combustível de óxido sólido de temperatura intermediária (ITSOFC. Este trabalho tem por objetivo a síntese e a caracterização do BSCF obtido pelo método dos citrados-EDTA. Os resultados obtidos por difração de raios X (DRX indicaram fases secundárias para o material calcinado a 700 e 800 ºC e fase única com estrutura cristalina do tipo perovskita para 900 ºC. As micrografias obtidas por microscopia eletrônica de varredura dos particulados evidenciou a formação de aglomerados de tamanho Ba0.50Sr0.50Co0.80Fe0.20O3-d (BSCF presents physical, chemical and microstructural properties suitable to form the cathode of Intermediate Temperature Solid Oxide Fuel Cell (ITSOFC. This work aims the synthesis and characterization of BSCF, obtained by the citrate-EDTA method. The X-ray diffraction results indicate secondary phases for the material calcined at 700 and 800 °C and single phase with perovskite crystalline structure at 900 °C. The SEM-FEG particles micrographs show the formation of < 20 µm clusters. The dilatometric analysis of pellets indicates the sintering temperature at ~ 1050 °C. XRD results of the sintered samples show perovskite single phase. The SEM micrographs confirmed the formation of higher porosity in the samples sintered at 1000 °C/1 h using powders calcined at 900 °C.

  18. Coronary Artery Disease - Reporting and Data System (CAD-RADS): An Expert Consensus Document of SCCT, ACR and NASCI: Endorsed by the ACC.

    Science.gov (United States)

    Cury, Ricardo C; Abbara, Suhny; Achenbach, Stephan; Agatston, Arthur; Berman, Daniel S; Budoff, Matthew J; Dill, Karen E; Jacobs, Jill E; Maroules, Christopher D; Rubin, Geoffrey D; Rybicki, Frank J; Schoepf, U Joseph; Shaw, Leslee J; Stillman, Arthur E; White, Charles S; Woodard, Pamela K; Leipsic, Jonathon A

    2016-09-01

    The intent of CAD-RADS - Coronary Artery Disease Reporting and Data System is to create a standardized method to communicate findings of coronary CT angiography (coronary CTA) in order to facilitate decision-making regarding further patient management. The suggested CAD-RADS classification is applied on a per-patient basis and represents the highest-grade coronary artery lesion documented by coronary CTA. It ranges from CAD-RADS 0 (Zero) for the complete absence of stenosis and plaque to CAD-RADS 5 for the presence of at least one totally occluded coronary artery and should always be interpreted in conjunction with the impression found in the report. Specific recommendations are provided for further management of patients with stable or acute chest pain based on the CAD-RADS classification. The main goal of CAD-RADS is to standardize reporting of coronary CTA results and to facilitate communication of test results to referring physicians along with suggestions for subsequent patient management. In addition, CAD-RADS will provide a framework of standardization that may benefit education, research, peer-review and quality assurance with the potential to ultimately result in improved quality of care.

  19. Mongoose: Creation of a Rad-Hard MIPS R3000

    Science.gov (United States)

    Lincoln, Dan; Smith, Brian

    1993-01-01

    This paper describes the development of a 32 Bit, full MIPS R3000 code-compatible Rad-Hard CPU, code named Mongoose. Mongoose progressed from contract award, through the design cycle, to operational silicon in 12 months to meet a space mission for NASA. The goal was the creation of a fully static device capable of operation to the maximum Mil-883 derated speed, worst-case post-rad exposure with full operational integrity. This included consideration of features for functional enhancements relating to mission compatibility and removal of commercial practices not supported by Rad-Hard technology. 'Mongoose' developed from an evolution of LSI Logic's MIPS-I embedded processor, LR33000, code named Cobra, to its Rad-Hard 'equivalent', Mongoose. The term 'equivalent' is used to infer that the core of the processor is functionally identical, allowing the same use and optimizations of the MIPS-I Instruction Set software tool suite for compilation, software program trace, etc. This activity was started in September of 1991 under a contract from NASA-Goddard Space Flight Center (GSFC)-Flight Data Systems. The approach affected a teaming of NASA-GSFC for program development, LSI Logic for system and ASIC design coupled with the Rad-Hard process technology, and Harris (GASD) for Rad-Hard microprocessor design expertise. The program culminated with the generation of Rad-Hard Mongoose prototypes one year later.

  20. Rad54 protein promotes branch migration of Holliday junctions.

    Science.gov (United States)

    Bugreev, Dmitry V; Mazina, Olga M; Mazin, Alexander V

    2006-08-03

    Homologous recombination has a crucial function in the repair of DNA double-strand breaks and in faithful chromosome segregation. The mechanism of homologous recombination involves the search for homology and invasion of the ends of a broken DNA molecule into homologous duplex DNA to form a cross-stranded structure, a Holliday junction (HJ). A HJ is able to undergo branch migration along DNA, generating increasing or decreasing lengths of heteroduplex. In both prokaryotes and eukaryotes, the physical evidence for HJs, the key intermediate in homologous recombination, was provided by electron microscopy. In bacteria there are specialized enzymes that promote branch migration of HJs. However, in eukaryotes the identity of homologous recombination branch-migration protein(s) has remained elusive. Here we show that Rad54, a Swi2/Snf2 protein, binds HJ-like structures with high specificity and promotes their bidirectional branch migration in an ATPase-dependent manner. The activity seemed to be conserved in human and yeast Rad54 orthologues. In vitro, Rad54 has been shown to stimulate DNA pairing of Rad51, a key homologous recombination protein. However, genetic data indicate that Rad54 protein might also act at later stages of homologous recombination, after Rad51 (ref. 13). Novel DNA branch-migration activity is fully consistent with this late homologous recombination function of Rad54 protein.

  1. Evolution of RAD- and DIV-Like Genes in Plants

    Directory of Open Access Journals (Sweden)

    Ao Gao

    2017-09-01

    Full Text Available Developmental genetic studies of Antirrhinum majus demonstrated that two transcription factors from the MYB gene family, RADIALIS (RAD and DIVIRICATA (DIV, interact through antagonism to regulate floral dorsoventral asymmetry. Interestingly, similar antagonistic interaction found among proteins of FSM1 (RAD-like and MYBI (DIV-like in Solanum lycopersicum is involved in fruit development. Here, we report the reconstruction of the phylogeny of I-box-like and R-R-type clades, where RAD- and DIV-like genes belong, respectively. We also examined the homology of these antagonistic MYB proteins using these phylogenies. The results show that there are likely three paralogs of RAD-/I-box-like genes, RAD1, RAD2, and RAD3, which originated in the common ancestor of the core eudicots. In contrast, R-R-type sequences fall into two major clades, RR1 and RR2, the result of gene duplication in the common ancestor of both monocots and dicots. RR1 was divided into clades RR1A, RR1B, and RR1C, while RR2 was divided into clades RR2A/DIV1, RR2B/DIV2, and RR2C/DIV3. We demonstrate that among similar antagonistic interactions in An. Majus and So. lycopersicum, RAD-like genes originate from the RAD2 clade, while DIV-like genes originate from distantly related paralogs of the R-R-type lineage. The phylogenetic analyses of these two MYB clades lay the foundation for future comparative studies including testing the evolution of the antagonistic relationship of proteins.

  2. Liquid rad waste system improvement at YGN 5 and 6

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B. S.; Kang, Y. H.; Shin, Y. H. [Korea Power Engineering Company Inc. (KOPEC), Yonggin, Kyunggido(Korea, Republic of)

    1999-07-01

    The performance of the rad waste system is measured in terms of the generation of waste volumes, the release of radioactive materials to the environment and the occupational radiation exposure to workers. Based on our design and operating experience from PWR plants, various design goals for the liquid rad waste system were developed to improve system performance. As a result of feasibility studies for an improved liquid rad waste system, a design concept was developed to meet the basic design goals, which have been incorporated into the YGN 5 and 6 system. As a result, the performance of the system will be significantly improved. (author)

  3. The Martian surface radiation environment – a comparison of models and MSL/RAD measurements

    Directory of Open Access Journals (Sweden)

    Matthiä Daniel

    2016-01-01

    Full Text Available Context: The Radiation Assessment Detector (RAD on the Mars Science Laboratory (MSL has been measuring the radiation environment on the surface of Mars since August 6th 2012. MSL-RAD is the first instrument to provide detailed information about charged and neutral particle spectra and dose rates on the Martian surface, and one of the primary objectives of the RAD investigation is to help improve and validate current radiation transport models. Aims: Applying different numerical transport models with boundary conditions derived from the MSL-RAD environment the goal of this work was to both provide predictions for the particle spectra and the radiation exposure on the Martian surface complementing the RAD sensitive range and, at the same time, validate the results with the experimental data, where applicable. Such validated models can be used to predict dose rates for future manned missions as well as for performing shield optimization studies. Methods: Several particle transport models (GEANT4, PHITS, HZETRN/OLTARIS were used to predict the particle flux and the corresponding radiation environment caused by galactic cosmic radiation on Mars. From the calculated particle spectra the dose rates on the surface are estimated. Results: Calculations of particle spectra and dose rates induced by galactic cosmic radiation on the Martian surface are presented. Although good agreement is found in many cases for the different transport codes, GEANT4, PHITS, and HZETRN/OLTARIS, some models still show large, sometimes order of magnitude discrepancies in certain particle spectra. We have found that RAD data is helping to make better choices of input parameters and physical models. Elements of these validated models can be applied to more detailed studies on how the radiation environment is influenced by solar modulation, Martian atmosphere and soil, and changes due to the Martian seasonal pressure cycle. By extending the range of the calculated particle

  4. Role of dissolved oxygen reduction in improvement inhibition performance of ascorbic acid during copper corrosion in 0.50 mol/L sulphuric acid

    Institute of Scientific and Technical Information of China (English)

    Mohammed; A.Amin

    2010-01-01

    The kinetics of dissolved O_2 reduction and hydrogen evolution reactions on copper surface was studied in naturally aerated and air and O_2-saturated 0.50 mol/L H_2SO_4 solutions using polarization measurements combined with the rotating disc electrode (RDE).The Koutecky-Levich plot indicated that the dissolved O_2 reduction at the copper electrode was an apparent four-electron process.A correlation between the presence of dissolved O_2 and the formation of Cu_2O,confirmed from XRD,was discussed. Ascorbi...

  5. RAD/COMM ''Cricket'' Test Report

    CERN Document Server

    Chiaro, P J

    2002-01-01

    A series of tests were performed at Oak Ridge National Laboratory (ORNL) to evaluate and characterize the radiological response of a ''Cricket'' radiation detection system. The ''Cricket'' is manufactured by RAD/COMM Systems Corp., which is located in Ontario, Canada. The system is designed to detect radioactive material that may be contained in scrap metal. The Cricket's detection unit is mounted to the base of a grappler and monitors material, while the grappler's tines hold the material. It can also be used to scan material in an attempt to isolate radioactive material if an alarm occurs. Testing was performed at the Environmental Effects Laboratory located at ORNL and operated by the Engineering Science and Technology Division. Tests performed included the following: (1) Background stability, (2) Energy response using sup 2 sup 4 sup 1 Am, sup 1 sup 3 sup 7 Cs, and sup 6 sup 0 Co, (3) Surface uniformity, (4) Angular dependence, (5) Alarm actuation, (6) Alarm threshold vs. background, (7) Shielding, (8) Re...

  6. RadNet-Air Near Real Time Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — RadNet-Air is a national network of air monitoring stations that regularly collect air samples for near real time analysis of radioactivity. The data is transmitted...

  7. RadNet (Environmental Radiation Ambient Monitoring System)

    Data.gov (United States)

    U.S. Environmental Protection Agency — RadNet, formerly Environmental Radiation Ambient Monitoring System (ERAMS), is a national network of monitoring stations that regularly collect air, precipitation,...

  8. Mre11-Rad50 complex crystals suggest molecular calisthenics

    NARCIS (Netherlands)

    C. Wyman (Claire); J.H.G. Lebbink (Joyce); R. Kanaar (Roland)

    2011-01-01

    textabstractRecently published crystal structures of different Mre11 and Rad50 complexes show the arrangement of these proteins and imply dramatic ligand-induced rearrangements with important functional consequences.

  9. RadNet Real-Time Monitoring Spectrometry Data Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The RadNet Real-Time Monitoring Spectrometry Data Inventory contains measured data used to identify and measure specific radioactive materials in the atmosphere at...

  10. An Overview of the Reliability and Availability Data System (RADS)

    Energy Technology Data Exchange (ETDEWEB)

    T. E. Wierman; K. J. Kvarfordt; S. A. Eide; D. M. Rasmuson

    2005-09-01

    The Reliability and Availability Data System (RADS) is a database and analysis code, developed by the Idaho National Engineering and Environmental Laboratory (INEEL) for the U.S. Nuclear Regulatory Commission (USNRC). The code is designed to estimate industry and plant-specific reliability and availability parameters for selected components in risk-important systems and initiating events for use in risk-informed applications. The RADS tool contains data and information based on actual operating experience from U.S. commercial nuclear power plants. The data contained in RADS is kept up-to-date by loading the most current quarter's Equipment Performance and Information Exchange (EPIX) data and by yearly lods of initiating event data from licensee event reports (LERS). The reliability parameters estimated by RADS are (1) probability of failure on demand, (2) failure rate during operation (used to calculate failure to run probability) and (3) time trends in reliability parameters.

  11. A comparative study between RadViz and Star Coordinates.

    Science.gov (United States)

    Rubio-Sánchez, Manuel; Raya, Laura; Díaz, Francisco; Sanchez, Alberto

    2016-01-01

    RadViz and star coordinates are two of the most popular projection-based multivariate visualization techniques that arrange variables in radial layouts. Formally, the main difference between them consists of a nonlinear normalization step inherent in RadViz. In this paper we show that, although RadViz can be useful when analyzing sparse data, in general this design choice limits its applicability and introduces several drawbacks for exploratory data analysis. In particular, we observe that the normalization step introduces nonlinear distortions, can encumber outlier detection, prevents associating the plots with useful linear mappings, and impedes estimating original data attributes accurately. In addition, users have greater flexibility when choosing different layouts and views of the data in star coordinates. Therefore, we suggest that analysts and researchers should carefully consider whether RadViz's normalization step is beneficial regarding the data sets' characteristics and analysis tasks.

  12. Role of the Saccharomyces cerevisiae Rad51 paralogs in sister chromatid recombination.

    Science.gov (United States)

    Mozlin, Amy M; Fung, Cindy W; Symington, Lorraine S

    2008-01-01

    Rad51 requires a number of other proteins, including the Rad51 paralogs, for efficient recombination in vivo. Current evidence suggests that the yeast Rad51 paralogs, Rad55 and Rad57, are important in formation or stabilization of the Rad51 nucleoprotein filament. To gain further insights into the function of the Rad51 paralogs, reporters were designed to measure spontaneous or double-strand break (DSB)-induced sister or nonsister recombination. Spontaneous sister chromatid recombination (SCR) was reduced 6000-fold in the rad57 mutant, significantly more than in the rad51 mutant. Although the DSB-induced recombination defect of rad57 was suppressed by overexpression of Rad51, elevated temperature, or expression of both mating-type alleles, the rad57 defect in spontaneous SCR was not strongly suppressed by these same factors. In addition, the UV sensitivity of the rad57 mutant was not strongly suppressed by MAT heterozygosity, even though Rad51 foci were restored under these conditions. This lack of suppression suggests that Rad55 and Rad57 have different roles in the recombinational repair of stalled replication forks compared with DSB repair. Furthermore, these data suggest that most spontaneous SCR initiates from single-stranded gaps formed at stalled replication forks rather than DSBs.

  13. Compensatory role for Rad52 during recombinational repair in Ustilago maydis

    DEFF Research Database (Denmark)

    Kojic, Milorad; Mao, Ninghui; Zhou, Qingwen

    2008-01-01

    in spontaneous mutator activity, allelic recombination or meiosis. GFP-Rad51 foci were formed in rad52 cells following DNA damage, but were initially less intense than normal suggesting a possible role for Rad52 in formation of the Rad51 nucleoprotein filament. A search for interacting genes that confer...

  14. Rec2 Interplay with both Brh2 and Rad51 Balances Recombinational Repair in Ustilago maydis

    DEFF Research Database (Denmark)

    Kojic, M.; Zhou, Q.; Lisby, M.;

    2006-01-01

    Rec2 is the single Rad51 paralog in Ustilago maydis. Here, we find that Rec2 is required for radiation-induced Rad51 nuclear focus formation but that Rec2 foci form independently of Rad51 and Brh2. Brh2 foci also form in the absence of Rad51 and Rec2. By coprecipitation from cleared extracts...

  15. Isolation, characterisation and expression patterns of a RAD51 ortholog from Pleurotus ostreatus

    NARCIS (Netherlands)

    Mikosch, T.S.P.; Sonnenberg, A.S.M.; Griensven, van L.J.L.D.

    2002-01-01

    AB: Using degenerated primers for conserved regions of RecA homologs we have isolated a gene from Pleurotus ostreatus that shows characteristic features of RAD51 homologs. The encoded amino acid sequence of P. ostreatus RAD51 (PoRAD51) shows greatest sequence similarities with RAD51 from Coprinus

  16. Isolation, characterisation and expression patterns of a RAD51 ortholog from Pleurotus ostreatus

    NARCIS (Netherlands)

    Mikosch, T.S.P.; Sonnenberg, A.S.M.; Griensven, van L.J.L.D.

    2002-01-01

    AB: Using degenerated primers for conserved regions of RecA homologs we have isolated a gene from Pleurotus ostreatus that shows characteristic features of RAD51 homologs. The encoded amino acid sequence of P. ostreatus RAD51 (PoRAD51) shows greatest sequence similarities with RAD51 from Coprinus ci

  17. Extracting BI-RADS Features from Portuguese Clinical Texts

    OpenAIRE

    Nassif, Houssam; Cunha, Filipe; Moreira, Inês C.; Cruz-Correia, Ricardo; Sousa, Eliana; Page, David; Burnside, Elizabeth; Dutra, Inês

    2012-01-01

    In this work we build the first BI-RADS parser for Portuguese free texts, modeled after existing approaches to extract BI-RADS features from English medical records. Our concept finder uses a semantic grammar based on the BIRADS lexicon and on iterative transferred expert knowledge. We compare the performance of our algorithm to manual annotation by a specialist in mammography. Our results show that our parser’s performance is comparable to the manual method.

  18. Extracting BI-RADS Features from Portuguese Clinical Texts

    OpenAIRE

    Nassif, Houssam; Cunha, Filipe; Moreira, Inês C; Cruz-Correia, Ricardo; Sousa, Eliana; Page, David; Burnside, Elizabeth; Dutra, Inês

    2012-01-01

    In this work we build the first BI-RADS parser for Portuguese free texts, modeled after existing approaches to extract BI-RADS features from English medical records. Our concept finder uses a semantic grammar based on the BIRADS lexicon and on iterative transferred expert knowledge. We compare the performance of our algorithm to manual annotation by a specialist in mammography. Our results show that our parser’s performance is comparable to the manual method.

  19. Structured reporting platform improves CAD-RADS assessment.

    Science.gov (United States)

    Szilveszter, Bálint; Kolossváry, Márton; Karády, Júlia; Jermendy, Ádám L; Károlyi, Mihály; Panajotu, Alexisz; Bagyura, Zsolt; Vecsey-Nagy, Milán; Cury, Ricardo C; Leipsic, Jonathon A; Merkely, Béla; Maurovich-Horvat, Pál

    2017-09-18

    Structured reporting in cardiac imaging is strongly encouraged to improve quality through consistency. The Coronary Artery Disease - Reporting and Data System (CAD-RADS) was recently introduced to facilitate interdisciplinary communication of coronary CT angiography (CTA) results. We aimed to assess the agreement between manual and automated CAD-RADS classification using a structured reporting platform. Five readers prospectively interpreted 500 coronary CT angiographies using a structured reporting platform that automatically calculates the CAD-RADS score based on stenosis and plaque parameters manually entered by the reader. In addition, all readers manually assessed CAD-RADS blinded to the automatically derived results, which was used as the reference standard. We evaluated factors influencing reader performance including CAD-RADS training, clinical load, time of the day and level of expertise. Total agreement between manual and automated classification was 80.2%. Agreement in stenosis categories was 86.7%, whereas the agreement in modifiers was 95.8% for "N", 96.8% for "S", 95.6% for "V" and 99.4% for "G". Agreement for V improved after CAD-RADS training (p = 0.047). Time of the day and clinical load did not influence reader performance (p > 0.05 both). Less experienced readers had a higher total agreement as compared to more experienced readers (87.0% vs 78.0%, respectively; p = 0.011). Even though automated CAD-RADS classification uses data filled in by the readers, it outperforms manual classification by preventing human errors. Structured reporting platforms with automated calculation of the CAD-RADS score might improve data quality and support standardization of clinical decision making. Copyright © 2017. Published by Elsevier Inc.

  20. RADTRAN 6/RadCat 6 user guide.

    Energy Technology Data Exchange (ETDEWEB)

    Weiner, Ruth F.; Hinojosa, Daniel; Heames, Terence John; Farnum, Cathy Ottinger; Kalinina, Elena Arkadievna

    2013-09-01

    This document provides a detailed discussion and a guide for the use of the RadCat 6.0 Graphical User Interface input file generator for the RADTRAN code, Version 6. RadCat 6.0 integrates the newest analysis capabilities of RADTRAN 6.0, including an economic model, updated loss-of-lead shielding model, a new ingestion dose model, and unit conversion. As of this writing, the RADTRAN version in use is RADTRAN 6.02.

  1. Recent Developments Using Small Molecules to Target RAD51: How to Best Modulate RAD51 for Anticancer Therapy?

    Science.gov (United States)

    Budke, Brian; Lv, Wei; Kozikowski, Alan P.

    2017-01-01

    Homologous recombination (HR) is an evolutionarily conserved DNA repair process. Overexpression of the key HR protein RAD51 is a common feature of malignant cells. RAD51 plays two distinct genome-stabilizing roles, including HR-mediated repair of double-strand breaks (DSBs) and the promotion of replication fork stability during replication stress. Because upregulation of RAD51 in cancer cells can promote tumor resistance to DNA-damaging oncologic therapies, we and others have worked to develop cancer therapeutics that target various aspects of RAD51 protein function. Herein, we provide an overview of recent developments in this field, together with our perspectives on the challenges associated with these evolving anticancer strategies. PMID:27781374

  2. Piezoelectric Ceramics of the (1 − x)Bi0.50Na0.50TiO3–xBa0.90Ca0.10TiO3 Lead-Free Solid Solution: Chemical Shift of the Morphotropic Phase Boundary, a Case Study for x = 0.06

    Science.gov (United States)

    Vivar-Ocampo, Rodrigo; Pardo, Lorena; Ávila, David; Morán, Emilio; González, Amador M.; Bucio, Lauro; Villafuerte-Castrejón, María-Elena

    2017-01-01

    Research and development of lead-free piezoelectric materials are still the hottest topics in the field of piezoelectricity. One of the most promising lead-free family of compounds to replace lead zirconate–titanate for actuators is that of Bi0.50Na0.50TiO3 (BNT) based solid solutions. The pseudo-binary (1 − x)Bi0.50Na0.50TiO3–xBa1 − yCayTiO3 system has been proposed for high temperature capacitors and not yet fully explored as piezoelectric material. In this work, the solid solution with x = 0.06 and y = 0.10 was obtained by two different synthesis routes: solid state and Pechini, aiming at using reduced temperatures, both in synthesis (<800 °C) and sintering (<1150 °C), while maintaining appropriated piezoelectric performance. Crystal structure, ceramic grain size, and morphology depend on the synthesis route and were analyzed by X-ray diffraction, together with scanning and transmission electron microscopy. The effects of processing and ceramic microstructure on the structural, dielectric, ferroelectric, and piezoelectric properties were discussed in terms of a shift of the Morphotropic Phase Boundary, chemically induced by the synthesis route. PMID:28773096

  3. Regulation of Rad51-Mediated Homologous Recombination by BRCA2, DSS1 and RAD52

    DEFF Research Database (Denmark)

    Rants, Louise Olthaver Juhl

    in governing the activity of Rad51 and to learn how other recombination-associated proteins such as DSS1 and RAD52 contribute to its regulation. We use the yeast-like fungus Ustilago maydis and the avian DT40 cell line as experimental systems since both have a well-conserved BRCA2-based recombinational repair...... system that resembles the one seen in human. In U. maydis, we show that Brh2, the BRCA2 homologue, and Dss1 colocalize at DNA damage-induced foci, with Dss1 exhibiting a dynamic association with Brh2 foci. Dss1 focus formation is dependent on interaction with full-length Brh2, and the Dss1-Brh2...... interaction is required for resistance to DNA damage. In avian DT40 cells, we show that endogenously tagged DSS1 redistributes into subnuclear foci in response to DNA damaging agents. However, DSS1 rarely colocalizes with BRCA2. Our data also indicate that both U. maydis Dss1 and avian DSS1 are involved...

  4. The AtRAD21.1 and AtRAD21.3 Arabidopsis cohesins play a synergistic role in somatic DNA double strand break damage repair

    OpenAIRE

    2014-01-01

    Background The RAD21 cohesin plays, besides its well-recognised role in chromatid cohesion, a role in DNA double strand break (dsb) repair. In Arabidopsis there are three RAD21 paralog genes (AtRAD21.1, AtRAD21.2 and AtRAD21.3), yet only AtRAD21.1 has been shown to be required for DNA dsb damage repair. Further investigation of the role of cohesins in DNA dsb repair was carried out and is here reported. Results We show for the first time that not only AtRAD21.1 but also AtRAD21.3 play a role ...

  5. Associations of UBE2I with RAD52, UBL1, p53, and RAD51 proteins in a yeast two-hybrid system

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Zhiyuan; Pardington-Purtymun, P.E.; Comeaux, J.C. [Los Alamos National Labs., NM (United States)] [and others

    1996-10-15

    The yeast RAD52-dependent pathway is involved in DNA recombination and double-strand break repair. Yeast ubiquitin-conjugating enzyme UBC9 participates in S- and M-phase cyclin degradation and mitotic control. Using the human RAD52 protein as the bait in a yeast two-hybrid system, we have identified a human homolog of yeast UBC9, designated UBE2I, that interacts with RAD52, RAD51, p53, and a ubiquitin-like protein UBL1. These interactions are UBE2I-specific, since another DNA repair-related ubiquitin-conjugating enzyme, RAD6 (UBC2), does not interact with these proteins. The interaction of UBE2I with RAD52 is mediated by RAD52`s self-association region. These results suggest that the RAD52-dependent processes, cell cycle control, p53-mediated pathway(s), and ubiquitination interact through human UBE2I. 22 refs., 3 figs.

  6. CEUS Helps to Rerate Small Breast Tumors of BI-RADS Category 3 and Category 4

    Directory of Open Access Journals (Sweden)

    Jian-xing Zhang

    2014-01-01

    Full Text Available Purpose. The primary aim of this study was to explore if classification, whether using the BI-RADS categories based on CEUS or conventional ultrasound, was conducive to the identification of benign and malignant category 3 or 4 small breast lesions. Material and Methods. We evaluated 30 malignant and 77 benign small breast lesions using CEUS. The range of enhancement, type of enhancement strength, intensity of enhancement, and enhancement patterns were independent factors included to assess the BI-RADS categories. Results. Of the nonenhanced breast lesions, 97.8% (44/45 were malignant, while, of the hyperplasic nodules, 96.8% (30/31 showed no enhancement in our study. Category changes of the lesions were made according to the features determined using CEUS. The results showed that these features could improve diagnostic sensitivity (from 70.0 to 80.0, 80.0, 90.0, and 90.0%, reduce the negative likelihood ratio (from 0.33 to 0.22, 0.25, 0.11, and 0.12, and improve the NPV (from 88.8 to 92.2, 91.2, 96.2, and 95.5%. However, this was not conducive to improve diagnostic specificity or the PPV. Conclusion. The vast majority of nonenhanced small breast lesions were malignant and most of the hyperplasic nodules showed no contrast enhancement. As a reference, CEUS was helpful in identifying BI-RADS category 3 or 4 small breast lesions.

  7. Stacking fault, microtopography and thermal decomposition studies of CrxW1-xSe2 (x=0.25, 0.50, 0.75) single crystals

    Science.gov (United States)

    Patel, D. D.; Desai, Priyanka; Jani, A. R.

    2014-08-01

    The single crystals of CrxW1-xSe2 (x=0.25, 0.50, 0.75) have been grown by the chemical vapour transport (CVT) technique using iodine as a transporting agent. The structural characterisation of these crystals has been made by the X-ray diffraction (XRD) method. The lattice parameters, unit cell volume, crystallite size, strain and dislocation densities have also been evaluated for these new crystals. The estimation of growth and deformation fault probabilities is further calculated. The grown crystals were examined under an optical zoom microscope for their surface topography. Thermo gravimetry analysis (TGA) and differential thermogravimetry (DTG) were carried for the CVT grown CrxW1-xSe2 single crystals. The different kinetic parameters: entropy, enthalpy and Gibbs free energy were calculated using Piloyan-Novikova (P-N) and Coats-Redfern (C-R) relations.

  8. Biocidal and Sporicidal Efficacy of Pathoster® 0.35% and Pathoster® 0.50% Against Bacterial Agents in Potential Bioterrorism Use

    Science.gov (United States)

    Candeliere, Antonio; Donatiello, Adelia; Pagano, Stefania; Iatarola, Michela; Tolve, Francesco; Antonino, Leonardo; Fasanella, Antonio

    2016-01-01

    The use of products that can neutralize or significantly reduce the microbial load and that are not harmful to human health and the environment represents a milestone in the fight against the spread of infectious diseases. Peracetic acid, besides being an excellent sterilizing and sporicidal agent, is harmless to humans and the environment when it is used in a common dosage. However, the high costs and loss of efficacy of the product very quickly after its reconstitution limit its use. We evaluated the efficacy and stability of 2 commercial products, based on stabilized peracetic acid (Pathoster® 0.35% and Pathoster® 0.50%) used against spores of Bacillus anthracis and spores of Bacillus cereus and vegetative forms of Yersinia pestis, Burkholderia mallei, Burkholderia pseudomallei, Francisella tularensis, Brucella abortus, and Brucella melitensis. The efficacy tests were based on the direct contact of the products with a standard suspension of the bacteria. The stability of the products was defined as the period of time during which the biocidal and sporicidal properties remained unchanged. The limit of effectiveness was the period after which the product was unable to exert a complete sterilization after a contact of 5 minutes with at least 1 of the 8 bacteria used in this work. Both formulations showed good efficacy against the microorganisms used in the study, confirming the utility of peracetic acid as a sterilizing product. After the reconstitution, Pathoster® 0.35% was stable until 16±1 days, while Pathoster® 0.50% was stable until 24±1 days. The formulations used in this study showed good performance and a significant stability of peracetic acid. PMID:27482880

  9. Development of microsatellite markers in the tetraploid fern Ceratopteris thalictroides (Parkeriaceae) using RAD tag sequencing.

    Science.gov (United States)

    Yang, X Y; Long, Z C; Gichira, A W; Guo, Y H; Wang, Q F; Chen, J M

    2016-02-19

    To understand the genetic variability of the tetraploid fern Ceratopteris thalictroides (Parkeriaceae), we described 30 polymorphic microsatellite markers obtained using the restriction site-associated DNA (RAD) tag sequencing technique. A total of 26 individuals were genotyped for each marker. The number of alleles per locus ranged from 4 to 10, and the expected heterozygosity and the Shannon-Wiener index ranged from 0.264 to 0.852 and 0.676 to 2.032, respectively. Because these 30 microsatellite markers exhibit high degrees of genetic variation, they will be useful tools for studying the adaptive genetic variation and sustainable conservation of C. thalictroides.

  10. RAD18 mediates resistance to ionizing radiation in human glioma cells

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Chen; Wang, Hongwei; Cheng, Hongbin; Li, Jianhua; Wang, Zhi, E-mail: drzwang@gmail.com; Yue, Wu, E-mail: drwuyue@gmail.com

    2014-02-28

    Highlights: • RAD18 is an important mediator of the IR-induced resistance in glioma cell lines. • RAD18 overexpression confers resistance to IR-mediated apoptosis. • The elevated expression of RAD18 is associated with recurrent GBM who underwent IR therapy. - Abstract: Radioresistance remains a major challenge in the treatment of glioblastoma multiforme (GBM). RAD18 a central regulator of translesion DNA synthesis (TLS), has been shown to play an important role in regulating genomic stability and DNA damage response. In the present study, we investigate the relationship between RAD18 and resistance to ionizing radiation (IR) and examined the expression levels of RAD18 in primary and recurrent GBM specimens. Our results showed that RAD18 is an important mediator of the IR-induced resistance in GBM. The expression level of RAD18 in glioma cells correlates with their resistance to IR. Ectopic expression of RAD18 in RAD18-low A172 glioma cells confers significant resistance to IR treatment. Conversely, depletion of endogenous RAD18 in RAD18-high glioma cells sensitized these cells to IR treatment. Moreover, RAD18 overexpression confers resistance to IR-mediated apoptosis in RAD18-low A172 glioma cells, whereas cells deficient in RAD18 exhibit increased apoptosis induced by IR. Furthermore, knockdown of RAD18 in RAD18-high glioma cells disrupts HR-mediated repair, resulting in increased accumulation of DSB. In addition, clinical data indicated that RAD18 was significantly higher in recurrent GBM samples that were exposed to IR compared with the corresponding primary GBM samples. Collectively, our findings reveal that RAD18 may serve as a key mediator of the IR response and may function as a potential target for circumventing IR resistance in human GBM.

  11. The C-terminal region of Rad52 is essential for Rad52 nuclear and nucleolar localization, and accumulation at DNA damage sites immediately after irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Koike, Manabu, E-mail: m_koike@nirs.go.jp [DNA Repair Gene Res., National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Yutoku, Yasutomo [DNA Repair Gene Res., National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Graduate School of Science, Chiba University, Yayoicho, Inage-ku, Chiba 263-8522 (Japan); Koike, Aki [DNA Repair Gene Res., National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)

    2013-05-31

    Highlights: •Rad52 might play a key role in the repair of DSB immediately after irradiation. •EYFP-Rad52 accumulates rapidly at DSB sites and colocalizes with Ku80. •Accumulation of Rad52 at DSB sites is independent of the core NHEJ factors. •Localization and recruitment of Rad52 to DSB sites are dependent on the Rad52 CTR. •Basic amino acids in Rad52 CTR are highly conserved among vertebrate species. -- Abstract: Rad52 plays essential roles in homologous recombination (HR) and repair of DNA double-strand breaks (DSBs) in Saccharomyces cerevisiae. However, in vertebrates, knockouts of the Rad52 gene show no hypersensitivity to agents that induce DSBs. Rad52 localizes in the nucleus and forms foci at a late stage following irradiation. Ku70 and Ku80, which play an essential role in nonhomologous DNA-end-joining (NHEJ), are essential for the accumulation of other core NHEJ factors, e.g., XRCC4, and a HR-related factor, e.g., BRCA1. Here, we show that the subcellular localization of EYFP-Rad52(1–418) changes dynamically during the cell cycle. In addition, EYFP-Rad52(1–418) accumulates rapidly at microirradiated sites and colocalizes with the DSB sensor protein Ku80. Moreover, the accumulation of EYFP-Rad52(1–418) at DSB sites is independent of the core NHEJ factors, i.e., Ku80 and XRCC4. Furthermore, we observed that EYFP-Rad52(1–418) localizes in nucleoli in CHO-K1 cells and XRCC4-deficient cells, but not in Ku80-deficient cells. We also found that Rad52 nuclear localization, nucleolar localization, and accumulation at DSB sites are dependent on eight amino acids (411–418) at the end of the C-terminal region of Rad52 (Rad52 CTR). Furthermore, basic amino acids on Rad52 CTR are highly conserved among mammalian, avian, and fish homologues, suggesting that Rad52 CTR is important for the regulation and function of Rad52 in vertebrates. These findings also suggest that the mechanism underlying the regulation of subcellular localization of Rad52 is

  12. Molecular Basis for Enhancement of the Meiotic DMCI Recombinase by RAD51AP1

    Energy Technology Data Exchange (ETDEWEB)

    Dray, Eloise; Dunlop, Myun Hwa; Kauppi, Liisa; San Filippo, Joseph San; Wiese, Claudia; Tsai, Miaw-Sheue; Begovic, Sead; Schild, David; Jasin, Maria; Keeney, Scott; Sung, Patrick

    2010-11-05

    Homologous recombination is needed for meiotic chromosome segregation, genome maintenance, and tumor suppression. RAD51AP1 (RAD51 Associated Protein 1) has been shown to interact with and enhance the recombinase activity of RAD51. Accordingly, genetic ablation of RAD51AP1 leads to enhanced sensitivity to and also chromosome aberrations upon DNA damage, demonstrating a role for RAD51AP1 in mitotic homologous recombination. Here we show physical association of RAD51AP1 with the meiosis-specific recombinase DMC1 and a stimulatory effect of RAD51AP1 on the DMC1-mediated D-loop reaction. Mechanistic studies have revealed that RAD51AP1 enhances the ability of the DMC1 presynaptic filament to capture the duplex DNA partner and to assemble the synaptic complex, in which the recombining DNA strands are homologously aligned. We also provide evidence that functional co-operation is dependent on complex formation between DMC1 and RAD51AP1, and that distinct epitopes in RAD51AP1 mediate interactions with RAD51 and DMC1. Finally, we show that RAD51AP1 is expressed in mouse testes, and that RAD51AP1 foci co-localize with a subset of DMC1 foci in spermatocytes. These results suggest that RAD51AP1 also serves an important role in meiotic homologous recombination.

  13. Interdependence of the Rad50 hook and globular domain functions

    Science.gov (United States)

    Hohl, Marcel; Kochańczyk, Tomasz; Tous, Cristina; Aguilera, Andrés; Krężel, Artur; Petrini, John H J

    2015-01-01

    SUMMARY Rad50 contains a conserved Zn2+ coordination domain (the Rad50 hook) that functions as a homodimerization interface. Hook ablation phenocopies Rad50 deficiency in all respects. Here we focused on rad50 mutations flanking the Zn2+-coordinating hook cysteines. These mutants impaired hook-mediated dimerization, but recombination between sister chromatids was largely unaffected. This may reflect that cohesin-mediated sister chromatid interactions are sufficient for double strand break repair. However, Mre11 complex functions specified by the globular domain, including Tel1 (ATM) activation, nonhomologous end-joining, and DNA double strand break end resection were affected, suggesting that dimerization exerts a broad influence on Mre11 complex function. These phenotypes were suppressed by mutations within the coiled coil and globular ATPase domain, suggesting a model in which conformational changes in the hook and globular domains are transmitted via the extended coils of Rad50. We propose that transmission of spatial information in this manner underlies the regulation of Mre11 complex functions. PMID:25601756

  14. Avaliação das propriedades do Ba0,50Sr0,50Co0,80Fe0,20O3-d para células a combustível de óxido sólido de temperatura intermediária obtido pelo método citratos-EDTA

    OpenAIRE

    E. Bonturim; VARGAS, R.A.; Andreoli,M.; SEO, E.S.M.

    2013-01-01

    Ba0,50Sr0,50Co0,80Fe0,20O3-d (BSCF) apresenta propriedades físicas, químicas e microestruturais adequadas para compor o cátodo de uma célula a combustível de óxido sólido de temperatura intermediária (ITSOFC). Este trabalho tem por objetivo a síntese e a caracterização do BSCF obtido pelo método dos citrados-EDTA. Os resultados obtidos por difração de raios X (DRX) indicaram fases secundárias para o material calcinado a 700 e 800 ºC e fase única com estrutura cristalina do tipo perovskita par...

  15. Opposing Roles for Two Molecular Forms of Replication Protein A in Rad51-Rad54-Mediated DNA Recombination in Plasmodium falciparum

    OpenAIRE

    2013-01-01

    ABSTRACT The bacterial RecA protein and its eukaryotic homologue Rad51 play a central role in the homologous DNA strand exchange reaction during recombination and DNA repair. Previously, our lab has shown that PfRad51, the Plasmodium falciparum homologue of Rad51, exhibited ATPase activity and promoted DNA strand exchange in vitro. In this study, we evaluated the catalytic functions of PfRad51 in the presence of putative interacting partners, especially P. falciparum homologues of Rad54 and r...

  16. RAD51AP1-deficiency in vertebrate cells impairs DNA replication.

    Science.gov (United States)

    Parplys, Ann C; Kratz, Katja; Speed, Michael C; Leung, Stanley G; Schild, David; Wiese, Claudia

    2014-12-01

    RAD51-associated protein 1 (RAD51AP1) is critical for homologous recombination (HR) by interacting with and stimulating the activities of the RAD51 and DMC1 recombinases. In human somatic cells, knockdown of RAD51AP1 results in increased sensitivity to DNA damaging agents and to impaired HR, but the formation of DNA damage-induced RAD51 foci is unaffected. Here, we generated a genetic model system, based on chicken DT40 cells, to assess the phenotype of fully inactivated RAD51AP1 in vertebrate cells. Targeted inactivation of both RAD51AP1 alleles has no effect on either viability or doubling-time in undamaged cells, but leads to increased levels of cytotoxicity after exposure to cisplatin or to ionizing radiation. Interestingly, ectopic expression of GgRAD51AP1, but not of HsRAD51AP1 is able to fully complement in cell survival assays. Notably, in RAD51AP1-deficient DT40 cells the resolution of DNA damage-induced RAD51 foci is greatly slowed down, while their formation is not impaired. We also identify, for the first time, an important role for RAD51AP1 in counteracting both spontaneous and DNA damage-induced replication stress. In human and in chicken cells, RAD51AP1 is required to maintain wild type speed of replication fork progression, and both RAD51AP1-depleted human cells and RAD51AP1-deficient DT40 cells respond to replication stress by a slow-down of replication fork elongation rates. However, increased firing of replication origins occurs in RAD51AP1-/- DT40 cells, likely to ensure the timely duplication of the entire genome. Taken together, our results may explain why RAD51AP1 commonly is overexpressed in tumor cells and tissues, and we speculate that the disruption of RAD51AP1 function could be a promising approach in targeted tumor therapy.

  17. Mating-type suppression of the DNA-repair defect of the yeast rad6 delta mutation requires the activity of genes in the RAD52 epistasis group.

    Science.gov (United States)

    Yan, Y X; Schiestl, R H; Prakash, L

    1995-06-01

    The RAD6 gene of Saccharomyces cerevisiae is required for post-replication repair of UV-damaged DNA, UV mutagenesis, and sporulation. Here, we show that the radiation sensitivity of a MATa rad6 delta strain can be suppressed by the MAT alpha 2 gene carried on a multicopy plasmid. The a1-alpha 2 suppression is specific to the RAD6 pathway, as mutations in genes required for nucleotide excision repair or for recombinational repair do not show such mating-type suppression. The a1-alpha 2 suppression of the rad6 delta mutation requires the activity of the RAD52 group of genes, suggesting that suppression occurs by channelling of post-replication gaps present in the rad6 delta mutant into the RAD52 recombinational repair pathway. The a1-alpha 2 repressor could mediate this suppression via an enhancement in the expression, or the activity, of recombination genes.

  18. RadCat 3.0 user guide.

    Energy Technology Data Exchange (ETDEWEB)

    Hinojosa, Daniel; Penisten, Janelle J.; Dennis, Matthew L.; Osborn, Douglas M.; Weiner, Ruth F.; Heames, Terence John; Marincel, Michelle K.

    2009-05-01

    RADTRAN is an internationally accepted program and code for calculating the risks of transporting radioactive materials. The first versions of the program, RADTRAN I and II, were developed for NUREG-0170 (USNRC, 1977), the first environmental statement on transportation of radioactive materials. RADTRAN and its associated software have undergone a number of improvements and advances consistent with improvements in both available data and computer technology. The version of RADTRAN currently bundled with RadCat is RADTRAN 6.0. This document provides a detailed discussion and a guide for the use of the RadCat 3.0 Graphical User Interface input file generator for the RADTRAN code. RadCat 3.0 integrates the newest analysis capabilities of RADTRAN 6.0 which includes an economic model, updated loss-of-lead shielding model, and unit conversion. As of this writing, the RADTRAN version in use is RADTRAN 6.0.

  19. Synthesis and structure of (Rb{sub 0.50}Ba{sub 0.25})[UO{sub 2}(CH{sub 3}COO){sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Serezhkina, L. B., E-mail: Lserezh@ssu.samara.ru [Samara State University (Russian Federation); Peresypkina, E. V.; Virovets, A. V. [Russian Academy of Sciences, Institute of Inorganic Chemistry, Siberian Branch (Russian Federation); Klepov, V. V. [Samara State University (Russian Federation)

    2010-03-15

    A new compound (Rb{sub 0.50}Ba{sub 0.25})[UO{sub 2}(CH{sub 3}COO){sub 3}] is synthesized and its crystal structure is studied by X-ray diffraction. The compound crystallizes in the form of yellow plates belonging to the cubic crystal system. The unit cell parameter a = 17.0367(1) A, V = 4944.89(5) A{sup 3}, space group I 4 bar 3d, Z = 16, and R = 0.0182. The coordination polyhedron of the uranium atom is a hexagonal bipyramid with oxygen atoms of three acetate groups and the uranyl group in the vertices. The crystal chemical formula of the uranium-containing group is AB{sub 3}{sup 01}(A = UO{sub 2}{sup 2+}, B{sup 01} = CH{sub 3}COO{sup -}). The oxygen atoms of the acetate groups that enter the coordination polyhedron of uranium are bound to barium and rubidium atoms.

  20. Electrochemical properties of CeMg11 Ni+ x % Ni composites (x=0, 50, 100 and 200) prepared by ball-milling

    Institute of Scientific and Technical Information of China (English)

    WANG Li; WANG Xin-hua; CHEN Li-xin; CHEN Chang-pin

    2005-01-01

    The electrochemical properties of the as-cast CeMg11 Ni and ball-milled CeMg11 Ni+ x% Ni(x = 0, 50,100 and 200, mass fraction) composites were investigated. The results show that homogeneous amorphous phase of CeMg11 Ni+x% Ni composite can be obtained by ball-milling, and discharge capacity of the ball-milled CeMg11 Ni+x% Ni composites differs greatly depending on the amount of Ni introduced during milling. The CeMg11 Ni+200% Ni composite after 90 h ball-milling was found to exhibit a large discharge capacity of about 1 012 mAh/g at 303 K,and it also shows better charge-discharge cycling stability than those with lower Ni content. This remarkable improvement in electrochemical properties of the ball-milled composites seems to be attributed to the formation of an amorphous composite as well as the improvement of the surface state of the ball-milled particles.

  1. Sign reversal of magnetization and exchange bias in Ni(Cr1-xAlx)2O4 (x=0-0.50)

    Science.gov (United States)

    Barman, Junmoni; Ravi, S.

    2017-03-01

    Ni(Cr1-xAlx)2O4 (x=0-0.50) samples were prepared in single phase form by using sol-gel method and their structural and magnetic properties were studied. Al substitution transforms the crystal structure of NiCr2O4 from tetragonal cell with space group I41/amd to cubic cell of Fd 3 barm space group. Magnetization measurements by varying the temperature and magnetic field were carried out to investigate the interesting magnetization reversal and exchange bias behaviors. Magnetization reversal is observed for x=0.10 sample with a magnetic compensation temperature of 40 K and it is explained by considering different temperature dependences of magnetic moments of the two sublattices. Shifting of magnetic hysteresis loops towards the negative magnetic field axis and hence the presence of negative exchange bias field is observed for x=0.15 sample. The x=0.10 sample exhibits the tunable positive and negative exchange bias field. Exchange bias in these samples is explained considering the anisotropic exchange interaction between the ferrimagnetic and the antiferromagnetic components of magnetic spins. However, the sign reversal of exchange bias field is due to the change in domination of one ferrimagnetic sublattice over the other with variation in temperature. Both normal and inverse magnetocaloric effects are observed for x=0.10 sample.

  2. RadMonitor: radiology operations data mining in real time.

    Science.gov (United States)

    Chen, Richard; Mongkolwat, Pattanasak; Channin, David S

    2008-09-01

    This paper describes the web-based visualization interface of RadMonitor, a platform-independent web application designed to help manage the complexity of information flow within a health care enterprise. The system eavesdrops on Health Layer 7 traffic and parses statistical operational information into a database. The information is then presented to the user as a treemap--a graphical visualization scheme that simplifies the display of hierarchical information. While RadMonitor has been implemented for the purpose of analyzing radiology operations, its XML backend allows it to be reused for virtually any other hierarchical data set.

  3. Functional characterization and identification of mouse Rad51d splice variants

    Directory of Open Access Journals (Sweden)

    Rajesh Changanamkandath

    2009-03-01

    Full Text Available Abstract Background The homologous recombination (HR pathway is vital for maintaining genomic integrity through the restoration of double-stranded breaks and interstrand crosslinks. The RAD51 paralogs (RAD51B, RAD51C, RAD51D, XRCC2, XRCC3 are essential for this process in vertebrates, and the RAD51D paralog is unique in that it participates in both HR repair and telomere maintenance. RAD51D is also known to directly interact with the RAD51C and XRCC2 proteins. Rad51d splice variants have been reported in mouse and human tissues, supportive of a role for alternative splicing in HR regulation. The present study evaluated the interaction of the Rad51d splice isoform products with RAD51C and XRCC2 and their expression patterns. Results Yeast-2-hybrid analysis was used to determine that the Mus musculus Rad51d splice variant product RAD51DΔ7b (deleted for residues 219 through 223 was capable of interacting with both RAD51C and XRCC2 and that RAD51D+int3 interacted with XRCC2. In addition, the linker region (residues 54 through 77 of RAD51D was identified as a region that potentially mediates binding with XRCC2. Cellular localization, detected by EGFP fusion proteins, demonstrated that each of the splice variant products tested was distributed throughout the cell similar to the full-length protein. However, none of the splice variants were capable of restoring resistance of Rad51d-deficient cell lines to mitomycin C. RT-PCR expression analysis revealed that Rad51dΔ3 (deleted for exon 3 and Rad51dΔ5 (deleted for exon 5transcripts display tissue specific expression patterns with Rad51dΔ3 being detected in each tissue except ovary and Rad51dΔ5 not detected in mammary gland and testis. These expression studies also led to the identification of two additional Rad51d ubiquitously expressed transcripts, one deleted for both exon 9 and 10 and one deleted for only exon 10. Conclusion These results suggest Rad51d alternative splice variants potentially

  4. Alleles of the homologous recombination gene, RAD59, identify multiple responses to disrupted DNA replication in Saccharomyces cerevisiae.

    Science.gov (United States)

    Liddell, Lauren C; Manthey, Glenn M; Owens, Shannon N; Fu, Becky X H; Bailis, Adam M

    2013-10-14

    In Saccharomyces cerevisiae, Rad59 is required for multiple homologous recombination mechanisms and viability in DNA replication-defective rad27 mutant cells. Recently, four rad59 missense alleles were found to have distinct effects on homologous recombination that are consistent with separation-of-function mutations. The rad59-K166A allele alters an amino acid in a conserved α-helical domain, and, like the rad59 null allele diminishes association of Rad52 with double-strand breaks. The rad59-K174A and rad59-F180A alleles alter amino acids in the same domain and have genetically similar effects on homologous recombination. The rad59-Y92A allele alters a conserved amino acid in a separate domain, has genetically distinct effects on homologous recombination, and does not diminish association of Rad52 with double-strand breaks. In this study, rad59 mutant strains were crossed with a rad27 null mutant to examine the effects of the rad59 alleles on the link between viability, growth and the stimulation of homologous recombination in replication-defective cells. Like the rad59 null allele, rad59-K166A was synthetically lethal in combination with rad27. The rad59-K174A and rad59-F180A alleles were not synthetically lethal in combination with rad27, had effects on growth that coincided with decreased ectopic gene conversion, but did not affect mutation, unequal sister-chromatid recombination, or loss of heterozygosity. The rad59-Y92A allele was not synthetically lethal when combined with rad27, stimulated ectopic gene conversion and heteroallelic recombination independently from rad27, and was mutually epistatic with srs2. Unlike rad27, the stimulatory effect of rad59-Y92A on homologous recombination was not accompanied by effects on growth rate, cell cycle distribution, mutation, unequal sister-chromatid recombination, or loss of heterozygosity. The synthetic lethality conferred by rad59 null and rad59-K166A alleles correlates with their inhibitory effect on association

  5. Hybridization Capture Using RAD Probes (hyRAD, a New Tool for Performing Genomic Analyses on Collection Specimens.

    Directory of Open Access Journals (Sweden)

    Tomasz Suchan

    Full Text Available In the recent years, many protocols aimed at reproducibly sequencing reduced-genome subsets in non-model organisms have been published. Among them, RAD-sequencing is one of the most widely used. It relies on digesting DNA with specific restriction enzymes and performing size selection on the resulting fragments. Despite its acknowledged utility, this method is of limited use with degraded DNA samples, such as those isolated from museum specimens, as these samples are less likely to harbor fragments long enough to comprise two restriction sites making possible ligation of the adapter sequences (in the case of double-digest RAD or performing size selection of the resulting fragments (in the case of single-digest RAD. Here, we address these limitations by presenting a novel method called hybridization RAD (hyRAD. In this approach, biotinylated RAD fragments, covering a random fraction of the genome, are used as baits for capturing homologous fragments from genomic shotgun sequencing libraries. This simple and cost-effective approach allows sequencing of orthologous loci even from highly degraded DNA samples, opening new avenues of research in the field of museum genomics. Not relying on the restriction site presence, it improves among-sample loci coverage. In a trial study, hyRAD allowed us to obtain a large set of orthologous loci from fresh and museum samples from a non-model butterfly species, with a high proportion of single nucleotide polymorphisms present in all eight analyzed specimens, including 58-year-old museum samples. The utility of the method was further validated using 49 museum and fresh samples of a Palearctic grasshopper species for which the spatial genetic structure was previously assessed using mtDNA amplicons. The application of the method is eventually discussed in a wider context. As it does not rely on the restriction site presence, it is therefore not sensitive to among-sample loci polymorphisms in the restriction sites

  6. Design, Synthesis, and Preclinical Characterization of the Selective Androgen Receptor Modulator (SARM) RAD140.

    Science.gov (United States)

    Miller, Chris P; Shomali, Maysoun; Lyttle, C Richard; O'Dea, Louis St L; Herendeen, Hillary; Gallacher, Kyla; Paquin, Dottie; Compton, Dennis R; Sahoo, Bishwabhusan; Kerrigan, Sean A; Burge, Matthew S; Nickels, Michael; Green, Jennifer L; Katzenellenbogen, John A; Tchesnokov, Alexei; Hattersley, Gary

    2011-02-10

    This report describes the discovery of RAD140, a potent, orally bioavailable, nonsteroidal selective androgen receptor modulator (SARM). The characterization of RAD140 in several preclinical models of anabolic androgen action is also described.

  7. Multiple start codons and phosphorylation result in discrete Rad52 protein species

    DEFF Research Database (Denmark)

    de Mayolo, A.A.; Lisby, M.; Erdeniz, N.

    2006-01-01

    protein species are due to promiscuous choice of start codons as well as post-translational modification. Specifically, Rad52 is phosphorylated both in a cell cycle-independent and in a cell cycle-dependent manner. Furthermore, phosphorylation is dependent on the presence of the Rad52 C terminus......The sequence of the Saccharomyces cerevisiae RAD52 gene contains five potential translation start sites and protein-blot analysis typically detects multiple Rad52 species with different electrophoretic mobilities. Here we define the gene products encoded by RAD52. We show that the multiple Rad52......, but not dependent on its interaction with Rad51. We also show that the Rad52 protein can be translated from the last three start sites and expression from any one of them is sufficient for spontaneous recombination and the repair of gamma-ray-induced double-strand breaks....

  8. The architecture of the human Rad54-DNA complex provides evidence for protein translocation along DNA.

    NARCIS (Netherlands)

    D. Ristic (Dejan); C. Wyman (Claire); C. Paulusma (Coen); R. Kanaar (Roland)

    2001-01-01

    textabstractProper maintenance and duplication of the genome require accurate recombination between homologous DNA molecules. In eukaryotic cells, the Rad51 protein mediates pairing between homologous DNA molecules. This reaction is assisted by the Rad54 protein. To gai

  9. RAD1 and RAD10, but not other excision repair genes, are required for double-strand break-induced recombination in Saccharomyces cerevisiae.

    Science.gov (United States)

    Ivanov, E L; Haber, J E

    1995-04-01

    HO endonuclease-induced double-strand breaks (DSBs) in the yeast Saccharomyces cerevisiae can be repaired by the process of gap repair or, alternatively, by single-strand annealing if the site of the break is flanked by directly repeated homologous sequences. We have shown previously (J. Fishman-Lobell and J. E. Haber, Science 258:480-484, 1992) that during the repair of an HO-induced DSB, the excision repair gene RAD1 is needed to remove regions of nonhomology from the DSB ends. In this report, we present evidence that among nine genes involved in nucleotide excision repair, only RAD1 and RAD10 are required for removal of nonhomologous sequences from the DSB ends. rad1 delta and rad10 delta mutants displayed a 20-fold reduction in the ability to execute both gap repair and single-strand annealing pathways of HO-induced recombination. Mutations in RAD2, RAD3, and RAD14 reduced HO-induced recombination by about twofold. We also show that RAD7 and RAD16, which are required to remove UV photodamage from the silent HML, locus, are not required for MAT switching with HML or HMR as a donor. Our results provide a molecular basis for understanding the role of yeast nucleotide excision repair gene and their human homologs in DSB-induced recombination and repair.

  10. Magnetic properties of the alloys system CuAl{sub 1-x}Cr{sub x}S{sub 2} (x = 0.50, 0.75); Propiedades magneticas del sistema de aleaciones CuAl{sub 1-x}Cr{sub x}S{sub 2} (x = 0.50, 0.75)

    Energy Technology Data Exchange (ETDEWEB)

    Villarreal, M. A.; Grima, P.; Quintero, M.; Moreno, E.; Fernandez, J. [Universidad de los Andes, Facultad de Ciencias, Centro de Estudios en Semiconductores, Departamento de Fisica, Apdo. de Correos No. 1, La Hechicera, 5251 Merida, (Venezuela, Bolivarian Republic of); Silva, P.; Villegas, J., E-mail: mavu@ula.ve [Instituto Venezolano de Investigaciones Cientificas, Laboratorio de Fisica de la Materia Condensada, Centro de Fisica, Carretera Panamericana Km. 11, Apdo. 21827, 1020-A Caracas (Venezuela, Bolivarian Republic of)

    2013-10-01

    The synthesis, structural characterization and magnetic properties of alloy system CuAl{sub 1-x}Cr{sub x}S{sub 2} (x = 0.50, 075) are reported. The samples were synthesized by using the direct fusion technique. The chemical analysis (EDX) confirmed the stoichiometric ratio for the concentrations. The powder diffraction patterns were indexed and the principal phases crystallizes with tetragonal symmetry with unit cell parameters a = 5.312(1) A, c = 10.389(2) A for x = 0.50 and a = 5.314(2) A, c = 10.393(2) A for x = 0.75. These alloys behave as antiferromagnetic, with Neel temperature of 37 K and 39 K, respectively. The EPR linewidth for these alloys shows a paramagnetic behavior between 100 and 610 K. The resonance field and the g factor show a slight variation with temperature. These results are discussed in terms of nearest-neighbor Cr{sup +3} (S=3/2) spin-coupled pairs. (Author)

  11. Rad51同系物与DNA重组修复

    Institute of Scientific and Technical Information of China (English)

    陈汉春; 彭兴华

    2003-01-01

    真核细胞Rad51蛋白质与原核细胞RecA蛋白质具有结构及功能同源性,是促使细胞有丝分裂及减数分裂过程中DNA同源重组的关键性蛋白质.已在酵母细胞中鉴定出Rad55和Rad57两种Rad51同系物,从脊椎动物细胞中鉴定出5种Rad51同系物,即Rad51B、Rad51C、Rad51D、Xrcc2和Xrcc3.这些Rad51同系物与Rad51之间及各同系物之间共享20%~30%的序列同一性,这些Rad51同系物与Rad51蛋白质共同作用而在受损DNA的同源重组修复过程中发挥重要作用.

  12. File list: Oth.EmF.10.Rad21.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.EmF.10.Rad21.AllCell mm9 TFs and others Rad21 Embryonic fibroblast SRX976730,SR...X976731,SRX976732,SRX976729 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.EmF.10.Rad21.AllCell.bed ...

  13. File list: Oth.Spl.50.Rad21.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Spl.50.Rad21.AllCell mm9 TFs and others Rad21 Spleen SRX701158,SRX701162,SRX701...161,SRX701156,SRX701154,SRX701157,SRX701155,SRX701159,SRX701160 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Spl.50.Rad21.AllCell.bed ...

  14. File list: Oth.Neu.20.Rad21.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.20.Rad21.AllCell mm9 TFs and others Rad21 Neural SRX326210,SRX116260,SRX326...212,SRX116261 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.20.Rad21.AllCell.bed ...

  15. ATP-dependent and independent functions of Rad54 in genome maintenance

    NARCIS (Netherlands)

    S. Agarwal (Sheba); W.A. van Cappellen (Gert); A. Guénolé (Aude); B. Eppink (Berina); S.E.V. Linsen (Sam); E. Meijering (Erik); A.B. Houtsmuller (Adriaan); R. Kanaar (Roland); J. Essers (Jeroen)

    2011-01-01

    textabstractRad54, a member of the SWI/SNF protein family of DNA-dependent ATPases, repairs DNA double-strand breaks (DSBs) through homologous recombination. Here we demonstrate that Rad54 is required for the timely accumulation of the homologous recombination proteins Rad51 and Brca2 at DSBs. Becau

  16. Disruption of mouse RAD54 reduces ionizing radiation resistance and homologous recombination.

    NARCIS (Netherlands)

    J. Essers (Jeroen); R.W. Hendriks (Rudi); S.M.A. Swagemakers (Sigrid); C. Troelstra (Christine); J. de Wit (Jan); D. Bootsma (Dirk); J.H.J. Hoeijmakers (Jan); R. Kanaar (Roland)

    1997-01-01

    textabstractDouble-strand DNA break (DSB) repair by homologous recombination occurs through the RAD52 pathway in Saccharomyces cerevisiae. Its biological importance is underscored by the conservation of many RAD52 pathway genes, including RAD54, from fungi to humans. We have analyzed the phenotype o

  17. Nuclear dynamics of RAD52 group homologous recombination proteins in response to DNA damage.

    NARCIS (Netherlands)

    J. Essers (Jeroen); A.B. Houtsmuller (Adriaan); L.R. van Veelen (Lieneke); C. Paulusma (Coen); A.L. Nigg (Alex); A. Pastink (Albert); W. Vermeulen (Wim); J.H.J. Hoeijmakers (Jan); R. Kanaar (Roland)

    2002-01-01

    textabstractRecombination between homologous DNA molecules is essential for the proper maintenance and duplication of the genome, and for the repair of exogenously induced DNA damage such as double-strand breaks. Homologous recombination requires the RAD52 group proteins, including Rad51, Rad52 and

  18. Meiotic and mitotic functions of mammalian RAD 18 in DNA double-strand break repair

    NARCIS (Netherlands)

    A. Inagaki (Akiko)

    2010-01-01

    textabstractThis thesis focuses on the role of RAD 18 in DNA double-strand break (DSB ) repair. Much is known about the role of RAD 18, and its critical substrate PCNA in replication damage bypass (RDB ) repair. However, the roles of RAD 18 in DSB repair are still elusive, although several

  19. Meiotic and mitotic functions of mammalian RAD 18 in DNA double-strand break repair

    NARCIS (Netherlands)

    A. Inagaki (Akiko)

    2010-01-01

    textabstractThis thesis focuses on the role of RAD 18 in DNA double-strand break (DSB ) repair. Much is known about the role of RAD 18, and its critical substrate PCNA in replication damage bypass (RDB ) repair. However, the roles of RAD 18 in DSB repair are still elusive, although several interacti

  20. Stratification of mammographic computerized analysis by BI-RADS categories

    Energy Technology Data Exchange (ETDEWEB)

    Lederman, Richard [Department of Radiology, Hadassah University Hospital, Ein Kerem, Jerusalem (Israel); Leichter, Isaac [Department of Electro-Optics, Jerusalem College of Technology, P.O.B. 16031, Jerusalem (Israel); Buchbinder, Shalom [Department of Radiology of The Montefiore Medical Center, The University Hospital for the Albert Einstein College of Medicine, Bronx, New York (United States); Novak, Boris [Department of Applied Mathematics, Jerusalem College of Technology, P.O.B. 16031, Jerusalem 91160 (Israel); Bamberger, Philippe [Department of Electronics, Jerusalem College of Technology, POB 16031, Jerusalem (Israel); Fields, Scott [Department of Radiology, Hadassah University Hospital, Mt. Scopus, Jerusalem (Israel)

    2003-02-01

    The Breast Imaging Reporting and Data System (BI-RADS) was implemented to standardize characterization of mammographic findings. The purpose of the present study was to evaluate in which BI-RADS categories the changes recommended by computerized mammographic analysis are most beneficial. Archival cases including, 170 masses (101 malignant, 69 benign) and 63 clusters of microcalcifications (MCs; 36 malignant, 27 benign), were evaluated retrospectively, using the BI-RADS categories, by several radiologists, blinded to the pathology results. A computerized system then automatically extracted from the digitized mammogram features characterizing mammographic lesions, which were used to classify the lesions. The results of the computerized classification scheme were compared, by receiver operating characteristics (ROC) analysis, to the conventional interpretation. In the ''low probability of malignancy group'' (excluding BI-RADS categories 4 and 5), computerized analysis improved the A{sub z}of the ROC curve significantly, from 0.57 to 0.89. In the ''high probability of malignancy group'' (mostly category 5) the computerized analysis yielded an ROC curve with an A {sub z}of 0.99. In the ''intermediate probability of malignancy group'' computerized analysis improved the A {sub z}significantly, from 0.66 for to 0.83. Pair-wise analysis showed that in the latter group the modifications resulting from computerized analysis were correct in 83% of cases. Computerized analysis has the ability to improve the performance of the radiologists exactly in the BI-RADS categories with the greatest difficulties in arriving at a correct diagnosis. It increased the performance significantly in the problematic group of ''intermediate probability of malignancy'' and pinpointed all the cases with missed cancers in the ''low probability'' group. (orig.)

  1. Effect of bacterial recA expression on DNA repair in the rad51 and rad52 mutants of Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    M.A. Morais Jr.

    1998-03-01

    Full Text Available Molecular and functional homology between yeast proteins pRad51 and pRad52 and Escherichia coli pRecA involved in recombinational DNA repair led us to investigate possible effects of recA gene expression on DNA repair in rad51 and rad52 mutants of Saccharomyces cerevisiae. The mutant cells were subjected to one of the following treatments: preincubation with 8-methoxypsoralen and subsequent irradiation with 360-nm ultraviolet (UVA (8-MOP + UVA, irradiation with 254-nm UV light or treatment with methyl methane sulfonate (MMS. While recA expression did not repair lethal DNA lesions in mutant rad51, it was able to partially restore resistance to 8-MOP + UVA and MMS in rad52. Expression of recA could not complement the sensitivity of rad51rad52 double mutants, indicating that pRad51 may be essential for the repair-stimulating activity of pRecA in the rad52 mutant. Spontaneous mutagenesis was increased, and 8-MOP-photoinduced mutagenesis was decreased by the presence of pRecA in rad52, whereas pRecA decreased UV-induced mutagenesis in rad51. Thus, pRecA may function in yeast DNA repair either as a member of a protein complex or as an individual protein that binds to mutagen-damaged DNA.A homologia tanto a nível molecular como funcional entre as proteínas de leveduras pRad51 e pRad52 envolvidas na reparação de DNA tipo recombinacional e pRecA de E. coli nos levou a analisar os possíveis efeitos da expressão do gene recA sobre a reparação de DNA nos mutantes rad51 e rad52 de S. cerevisiae após tratamento com 8-MOP + UVA, com UV e com MMS. A expressão de recA não foi capaz de restaurar a reparação das lesões induzidas no DNA do mutante rad51 após tratamento com esses agentes, entretanto ela restaurou parcialmente a resistência ao 8-MOP + UVA e ao MMS no mutante rad52. A expressão de recA não complementou a sensibilidade do duplo mutante rad51rad52, indicando que pRad51 pode ser essencial para estimular a atividade de reparação da p

  2. Role of reciprocal exchange, one-ended invasion crossover and single-strand annealing on inverted and direct repeat recombination in yeast: Different requirements for the RAD1, RAD 10, and RAD52 genes

    Energy Technology Data Exchange (ETDEWEB)

    Prado, F.; Aguilera, A. [Universidad de Sevilla (Spain)

    1995-01-01

    We have constructed novel DNA substrates (one inverted and three direct repeats) based on the same 0.6-kb repeat sequence to study deletions and inversions in Saccharomyces cerevisiae. Spontaneous deletions occur six to eight times more frequently than inversions, irrespective of the distance between the repeats. This difference can be explained by the observation that deletion events can be mediated by a recombination mechanism that can initiate within the intervening sequence of the repeats. Spontaneous and double-strand break (DSB)-induced deletions occur as RAD52-dependent and RAD52-independent events. Those deletion events initiated through a DSB in the unique intervening sequence require the Rad1/Rad10 endonuclease only if the break is distantly located from the flanking DNA repeats. We propose that deletions can occur as three types of recombination events: the conservative RAD52-dependent reciprocal exchange and the nonconservative events, one-ended invasion crossover, and single-strand annealing (SSA). We suggest that one-ended invasion is RAD52 dependent, whereas SSA is RAD52 independent. Whereas deletions, like inversions, occur through reciprocal exchange, deletions can also occur through SSA or one-ended invasion. We propose that the contribution of reciprocal exchange and one-ended invasion crossover vs. SSA events to overall spontaneous deletions is a feature specific for each repeat system, determined by the initiation event and the availability of the Rad52 protein. We discuss the role of the Rad1/Rad10 endonuclease on the initial steps of one-ended invasion crossover and SSA as a function of the location of the initiation event relative to the repeats. We also show that the frequency of recombination between repeats is the same independent of their location (whether on circular plasmids, linear minichromosomes, or natural chromosomes) and have similar RAD52 dependence. 74 refs., 5 figs., 6 tabs.

  3. Role of recA/RAD51 family proteins in mammals.

    Directory of Open Access Journals (Sweden)

    Kawabata,Masahiro

    2005-02-01

    Full Text Available

    DNA damage causes chromosomal instability leading to oncogenesis, apoptosis, and severe failure of cell functions. The DNA repair system includes base excision repair, nucleotide excision repair, mismatch repair, translesion replication, non-homologous end-joining, and recombinational repair. Homologous recombination performs the recombinational repair. The RAD51 gene is an ortholog of Esherichia coli recA, and the gene product Rad51 protein plays a central role in the homologous recombination. In mammals, 7 recA-like genes have been identified: RAD51, RAD51L1/B, RAD51L2/C, RAD51L3/D, XRCC2, XRCC3, and DMC1. These genes, with the exception of meiosis-specific DMC1, are essential for development in mammals. Disruption of the RAD51 gene leads to cell death, whereas RAD51L1/B, RAD51L2/C, RAD51L3/D, XRCC2, and XRCC3 genes (RAD51 paralogs are not essential for viability of cells, but these gene-deficient cells exhibit a similar defective phenotype. Yeast two-hybrid analysis, co-immunoprecipitation, mutation analysis, and domain mapping of Rad51 and Rad51 paralogs have revealed protein-protein interactions among these gene products. Recent investigations have shown that Rad51 paralogs play a role not only in an early step, but also in a late step of homologous recombination. In addition, identification of alternative transcripts of some RAD51 paralogs may reflect the complexity of the homologous recombination system.

  4. Fast neutron background characterization with the Radiological Multi-sensor Analysis Platform (RadMAP)

    Science.gov (United States)

    Davis, John R.; Brubaker, Erik; Vetter, Kai

    2017-06-01

    In an effort to characterize the fast neutron radiation background, 16 EJ-309 liquid scintillator cells were installed in the Radiological Multi-sensor Analysis Platform (RadMAP) to collect data in the San Francisco Bay Area. Each fast neutron event was associated with specific weather metrics (pressure, temperature, absolute humidity) and GPS coordinates. The expected exponential dependence of the fast neutron count rate on atmospheric pressure was demonstrated and event rates were subsequently adjusted given the measured pressure at the time of detection. Pressure adjusted data was also used to investigate the influence of other environmental conditions on the neutron background rate. Using National Oceanic and Atmospheric Administration (NOAA) coastal area lidar data, an algorithm was implemented to approximate sky-view factors (the total fraction of visible sky) for points along RadMAPs route. Three areas analyzed in San Francisco, Downtown Oakland, and Berkeley all demonstrated a suppression in the background rate of over 50% for the range of sky-view factors measured. This effect, which is due to the shielding of cosmic-ray produced neutrons by surrounding buildings, was comparable to the pressure influence which yielded a 32% suppression in the count rate over the range of pressures measured.

  5. Non-mass-like breast lesions at ultrasonography: Feature analysis and BI-RADS assessment

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Kai-Hsiung [Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China); Hsu, Hsian-He, E-mail: hsianhe@yahoo.com.tw [Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China); Yu, Jyh-Cherng [Department of Surgery, Division of General Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China); Peng, Yi-Jen [Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China); Tung, Ho-Jui [Department of Healthcare Administration, Asia University, Taichung, Taiwan, ROC (China); Chu, Chi-Ming [Section of Health Informatics, Institute of Public Health, National Defense Medical Center and University, Taipei, Taiwan, ROC (China); Chang, Tsun-Hou; Chang, Wei-Chou; Wu, Yu-Cheng; Lin, Yu-Pang; Hsu, Giu-Cheng [Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China)

    2015-01-15

    Highlights: • The positive predictive value of an NML lesion on ultrasound ranges from 10 to 79%. • A sizable number of NML malignant lesions are pure DCIS or ILC. • Biopsy is indicated for histopathological diagnosis when an ultrasound NML lesion is recognized. - Abstract: Objective: To analyze the features of non-mass-like (NML) breast lesions on ultrasound (US) and determine their corresponding malignancy rate and to stratify these lesion patterns according to US BI-RADS categories. Materials and methods: One hundred sixty-four consecutive lesions were retrospectively classified into four types according to the US features, the corresponding positive predictive values (PPVs) were obtained. Clinical, imaging, and histopathological findings were reviewed. Results: Among the 164 lesions, 39 (24%) were classified as type Ia, 14 (8%) as type Ib, 39 (24%) as type IIa, 19 (12%) as type IIb, 19 (12%) as type III, and 34 (21%) as type IV. The PPVs for malignancy were 21% for type Ia, 79% for type Ib, 10% for type IIa, 58% for type IIb, 16% for type III, and 21% for type IV. All NML lesions were classified as BI-RADS category 4a (type IIa), 4b (type Ia, III and IV) and 4c (type Ib and IIb) according to their PPVs. There was a significantly higher frequency of malignancy among lesions of type Ib and type IIb compared with the other types (P < 0.01 for each). Lesions with associated calcifications, presence of abnormal axillary nodes, or a mammographic finding of suspected malignancy had a higher probability of malignancy (P < 0.05 for each). Conclusion: US is useful in clarifying the indication for biopsy of NML lesions. The types of US classifications used in our study establish reliable references for the NML patterns when stratified according to the BI-RADS categories.

  6. RAD51 is required for propagation of the germinal nucleus in Tetrahymena thermophila.

    OpenAIRE

    Marsh, T C; Cole, E. S.; Stuart, K R; Campbell, C; Romero, D P

    2000-01-01

    RAD51, the eukaryote homolog of the Escherichia coli recA recombinase, participates in homologous recombination during mitosis, meiosis, and in the repair of double-stranded DNA breaks. The Tetrahymena thermophila RAD51 gene was recently cloned, and the in vitro activities and induction of Rad51p following DNA damage were shown to be similar to that of RAD51 from other species. This study describes the pattern of Tetrahymena RAD51 expression during both the cell cycle and conjugation. Tetrahy...

  7. Monitoreo de Radón 222 en la zona sur de Lima

    OpenAIRE

    Rojas Hancco, Jhonny Jonnatan

    2016-01-01

    Existen diversos estudios de las concentraciones de Radón 222 [36], los cuales comenzaron en minas, el objetivo de este tipo de estudios era determinar la dosis a la que estaban expuestos los trabajadores por diversas fuentes naturales entre ellas el Radón, las concentraciones de Radón 222 encontradas fueron muy elevadas llegando a la conclusión que las hijas del Radón 222 son las mas nocivas adicionándose a los efectos que causa el fumar, dado que el Radón 222 es un gas exhalado por el suelo...

  8. CRED Coral Reef Early Warning System (CREWS) Standard Buoy, Supplemental Sea Surface Temperature Recorder (SBE39); NWHI, PHR; Long: -175.81590, Lat: 27.85408 (WGS84); Sensor Depth: 0.50m; Data Range: 20030801-20030810.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CREWS Standard (CREWS-STD) buoys are equipped to measure sea surface water temperature and conductivity (Sea-Bird Model SBE37-SM, Sea-Bird Electronics, Inc.,...

  9. In-plane magnetic properties of as-spun Y {sub x} Pr{sub 1-} {sub x} Co{sub 5} ribbons (x=0.25, 0.50, 0.75)

    Energy Technology Data Exchange (ETDEWEB)

    Santana Gil, A. [Laboratorio de Magnetismo, Facultad de Fisica-IMRE, Universidad de La Habana, La Habana 10400 (Cuba); Sanchez Ll, J.L. [Laboratorio de Magnetismo, Facultad de Fisica-IMRE, Universidad de La Habana, La Habana 10400 (Cuba) and Departamento de Fisica, Facultad de Ciencias, Universidad de Oviedo, Calvo Sotelo s/n, 33007 Oviedo (Spain)]. E-mail: sanchez@nanomagnetics.org; Valenzuela, R. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, P.O. Box 70-360, Coyoacan, Mexico D.F., 04510 (Mexico); Hernando, B. [Departamento de Fisica, Facultad de Ciencias, Universidad de Oviedo, Calvo Sotelo s/n, 33007 Oviedo (Spain); Perez, M.J. [Departamento de Fisica, Facultad de Ciencias, Universidad de Oviedo, Calvo Sotelo s/n, 33007 Oviedo (Spain); Santos, J.D. [Departamento de Fisica, Facultad de Ciencias, Universidad de Oviedo, Calvo Sotelo s/n, 33007 Oviedo (Spain)

    2007-09-15

    As-spun ribbons of Y {sub x} Pr{sub 1-} {sub x} Co{sub 5} alloys with x=0.25, 0.50, and 0.75, were produced by single-roller melt spinning at wheel speeds of 5, 15, and 40 ms{sup -1}. X-ray diffraction patterns and SEM micrographs show that samples are essentially single phase with the hexagonal CaCu{sub 5}-type crystal structure and dendritic microstructure. Hysteresis loops were measured in the plane of ribbons applying the magnetic field along and perpendicular to ribbon plane. Samples exhibit in-plane reduced remanence above 0.5, with a noticeable value of 0.86 for the alloy Y{sub 0.5}Pr{sub 0.5}Co{sub 5} quenched at v=15 ms{sup -1}. XRD patterns obtained for the surface of ribbons confirmed that the high remanence measured results from the preferential orientation of 1:5 grains with their c-axis parallel to the ribbon plane. This in-plane crystallographic texture is attributed to the directional solidification induced by thermal gradient during rapid quenching. Coercivity rises with the increase of both, Pr content and wheel speed with values in the range 1.0-5.2 kOe.

  10. RadA: A protein involved in DNA damage repair processes of Deinococcus radiodurans R1

    Institute of Scientific and Technical Information of China (English)

    ZHOU Qing; ZHANG Xinjue; XU Hong; XU Bujin; HUA Yuejin

    2006-01-01

    RadA is highly conserved in bacteria and belongs to the RecA/RadA/Rad51 protein superfamily found in bacteria, archaea and eukarya. In Archaea, it plays a critical role in homologous recombination process due to its RecA-like function. In Escherichia coli, it takes part in conjugational recombination and DNA repair but is not as important as that of archaea. Using PSI-BLAST searches, we found that Deinococcus radiodurans RadA had a higher similarity to that of bacteria than archaea and eukarya. Disruption of radA gene in D. radiodurans resulted in a modestly decreased resistance to gamma radiation and ultraviolet, but had no effect on the resistance to hydrogen peroxide. Complementation of the radA disruptant by both E. coli radA and D.radiodurans radA could fully restore its resistance to gamma radiation and ultraviolet irradiation. Further domain function analyses of D. radiodurans RadA showed that the absence of the zinc finger domain resulted in a slightly more sensitive phenotype togamma and UV radiation than that of the radA mutant,while the absence of the Lon protease domain exhibited a slightly increased resistance to gamma and UV radiation. These data suggest that D. radiodurans RadA does play an important role in the DNA damage repair processes and its three different domains have different functions.

  11. The Different Roles of hRAD50 in Microsatellite Stable and Unstable Colorectal Cancers

    Directory of Open Access Journals (Sweden)

    Jingfang Gao

    2008-01-01

    Full Text Available RAD50 protein is essential for DNA double-strand break repair and maintaining genomic integrity. In this study, we investigated the clinicopathological significance of hRAD50 expression and mutation in microsatellite stable (MSS and unstable (MSI colorectal cancers (CRCs. hRAD50 expression was examined in primary CRC (n=268, the corresponding distant (n=69 and adjacent normal mucosa (n=138, and lymph node metastasis (n=44 by immunohistochemistry. hRAD50 mutation was analyzed in 87 primary CRCs by PCR-SSCP-DNA sequencing. hRAD50 expression was increased in MSS primary CRCs, but not MSI ones, compared with distant/adjacent normal mucosa (p<0.05. There was no difference in the hRAD50 expression between primary and metastatic CRCs. The increased hRAD50 expression in MSS primary CRCs was related (p<0.05 or tended to be related (p=0.05 to early tumor stage, better differentiation, high inflammatory infiltration, p53 overexpression. Frameshift mutations of (A9 at coding region of hRAD50 were only found in MSI CRCs. Our results suggest that hRAD50 may play different roles in the development of MSS and MSI CRCs: increased hRAD50 expression in MSS CRCs may be a cellular response against tumor from further progression, while hRAD50 mutation may be involved in the development of MSI CRCs.

  12. The Bloom syndrome protein limits the lethality associated with RAD51 deficiency.

    Science.gov (United States)

    Lahkim Bennani-Belhaj, Kenza; Rouzeau, Sébastien; Buhagiar-Labarchède, Géraldine; Chabosseau, Pauline; Onclercq-Delic, Rosine; Bayart, Emilie; Cordelières, Fabrice; Couturier, Jérôme; Amor-Guéret, Mounira

    2010-03-01

    Little is known about the functional interaction between the Bloom's syndrome protein (BLM) and the recombinase RAD51 within cells. Using RNA interference technology, we provide the first demonstration that RAD51 acts upstream from BLM to prevent anaphase bridge formation. RAD51 downregulation was associated with an increase in the frequency of BLM-positive anaphase bridges, but not of BLM-associated ultrafine bridges. Time-lapse live microscopy analysis of anaphase bridge cells revealed that BLM promoted cell survival in the absence of Rad51. Our results directly implicate BLM in limiting the lethality associated with RAD51 deficiency through the processing of anaphase bridges resulting from the RAD51 defect. These findings provide insight into the molecular basis of some cancers possibly associated with variants of the RAD51 gene family.

  13. Ejecta model development at pRad (u)

    Energy Technology Data Exchange (ETDEWEB)

    Buttler, William T [Los Alamos National Laboratory; Oro, David M [Los Alamos National Laboratory; Dimonte, Guy [Los Alamos National Laboratory; Terrones, Guillermo [Los Alamos National Laboratory; Morris, Christopher [Los Alamos National Laboratory; Bainbridge, J R [Los Alamos National Laboratory; Hogan, Gary E. [Los Alamos National Laboratory; Hollander, Brian J. [Los Alamos National Laboratory; Holtkamp, David B. [Los Alamos National Laboratory; Kwiathowski, Kris [Los Alamos National Laboratory; Marr-Lyon, Mark [Los Alamos National Laboratory; Mariam, Fesseha G. [Los Alamos National Laboratory; Merrill, Frank E [Los Alamos National Laboratory; Nedrow, Paul [Los Alamos National Laboratory; Saunders, Alexander [Los Alamos National Laboratory; Schwartz, C L [Los Alamos National Laboratory; Stone, B [Los Alamos National Laboratory; Tupa, Dale [Los Alamos National Laboratory; Vogan-McNeil, Wendy S [Los Alamos National Laboratory

    2010-02-09

    In July 2009 we fielded three explosively (HE) driven Richtmyer-Meshkov instability experiments at the LANSCE Proton Radiography Facility (pRad), and in August of 2009 we fielded one flyer plate experiment on the pRad 40 mm powder gun. One HE experiment was done in vacuum, and the other two within four atmospheres of noble gasses: Xe and Ne. These two gases were chosen to study the viscous effects on ejecta formation. It is unexpected, but the viscosity {eta} of Ne is twice that of Xe, and, due to the atomic mass difference between the two, the kinematic viscosity ({eta}/{rho}) of Ne is about ten times that of Xe. The results showed that ejecta formation is sensitively linked to the gas density, which implies that the Weber number is more important in ejecta formation than the Reynolds number.

  14. Radiomic modeling of BI-RADS density categories

    Science.gov (United States)

    Wei, Jun; Chan, Heang-Ping; Helvie, Mark A.; Roubidoux, Marilyn A.; Zhou, Chuan; Hadjiiski, Lubomir

    2017-03-01

    Screening mammography is the most effective and low-cost method to date for early cancer detection. Mammographic breast density has been shown to be highly correlated with breast cancer risk. We are developing a radiomic model for BI-RADS density categorization on digital mammography (FFDM) with a supervised machine learning approach. With IRB approval, we retrospectively collected 478 FFDMs from 478 women. As a gold standard, breast density was assessed by an MQSA radiologist based on BI-RADS categories. The raw FFDMs were used for computerized density assessment. The raw FFDM first underwent log-transform to approximate the x-ray sensitometric response, followed by multiscale processing to enhance the fibroglandular densities and parenchymal patterns. Three ROIs were automatically identified based on the keypoint distribution, where the keypoints were obtained as the extrema in the image Gaussian scale-space. A total of 73 features, including intensity and texture features that describe the density and the parenchymal pattern, were extracted from each breast. Our BI-RADS density estimator was constructed by using a random forest classifier. We used a 10-fold cross validation resampling approach to estimate the errors. With the random forest classifier, computerized density categories for 412 of the 478 cases agree with radiologist's assessment (weighted kappa = 0.93). The machine learning method with radiomic features as predictors demonstrated a high accuracy in classifying FFDMs into BI-RADS density categories. Further work is underway to improve our system performance as well as to perform an independent testing using a large unseen FFDM set.

  15. Disparate requirements for the Walker A and B ATPase motifs ofhuman RAD51D in homologous recombination

    Energy Technology Data Exchange (ETDEWEB)

    Wiese, Claudia; Hinz, John M.; Tebbs, Robert S.; Nham, Peter B.; Urbin, Salustra S.; Collins, David W.; Thompson, Larry H.; Schild, David

    2006-04-21

    In vertebrates, homologous recombinational repair (HRR) requires RAD51 and five RAD51 paralogs (XRCC2, XRCC3, RAD51B, RAD51C, and RAD51D) that all contain conserved Walker A and B ATPase motifs. In human RAD51D we examined the requirement for these motifs in interactions with XRCC2 and RAD51C, and for survival of cells in response to DNA interstrand crosslinks. Ectopic expression of wild type human RAD51D or mutants having a non-functional A or B motif was used to test for complementation of a rad51d knockout hamster CHO cell line. Although A-motif mutants complement very efficiently, B-motif mutants do not. Consistent with these results, experiments using the yeast two- and three-hybrid systems show that the interactions between RAD51D and its XRCC2 and RAD51C partners also require a functional RAD51D B motif, but not motif A. Similarly, hamster Xrcc2 is unable to bind to the non-complementing human RAD51D B-motif mutants in co-immunoprecipitation assays. We conclude that a functional Walker B motif, but not A motif, is necessary for RAD51D's interactions with other paralogs and for efficient HRR. We present a model in which ATPase sites are formed in a bipartite manner between RAD51D and other RAD51 paralogs.

  16. The human RAD54 recombinational DNA repair protein is a double-stranded DNA-dependent ATPase

    NARCIS (Netherlands)

    J. Essers (Jeroen); J. de Wit (Jan); R. Kanaar (Roland); J.H.J. Hoeijmakers (Jan); S.M.A. Swagemakers (Sigrid)

    1998-01-01

    textabstractDNA double-strand break repair through the RAD52 homologous recombination pathway in the yeast Saccharomyces cerevisiae requires, among others, the RAD51, RAD52, and RAD54 genes. The biological importance of homologous recombination is underscored by the conservation of

  17. Cloning, comparative mapping, and RNA expression of the mouse homologues of the Saccharomyces cerevisiae nucleotide excision repair gene RAD23.

    NARCIS (Netherlands)

    P.J. van der Spek (Peter); C.E. Visser (Cécile); F. Hanaoka (Fumio); B. Smit (Bep); A. Hagemeijer (Anne); D. Bootsma (Dirk); J.H.J. Hoeijmakers (Jan)

    1996-01-01

    textabstractThe Saccharomyces cerevisiae RAD23 gene is involved in nucleotide excision repair (NER). Two human homologs of RAD23, HHR23A and HHR23B (HGMW-approved symbols RAD23A and RAD23B), were previously isolated. The HHR23B protein is complexed with the protein defective in the cancer-prone

  18. Cloning of human and mouse genes homologous to RAD52, a yeast gene involved in DNA repair and recombination.

    NARCIS (Netherlands)

    D.F.R. Muris; O.Y. Bezzubova (Olga); J-M. Buerstedde; K. Vreeken; A.S. Balajee; C.J. Osgood; C. Troelstra (Christine); J.H.J. Hoeijmakers (Jan); K. Ostermann; H. Schmidt (Henning); A.T. Natarajan; J.C.J. Eeken; P.H.M. Lohmann (Paul); A. Pastink (Albert)

    1994-01-01

    textabstractThe RAD52 gene of Saccharomyces cerevisiae is required for recombinational repair of double-strand breaks. Using degenerate oligonucleotides based on conserved amino acid sequences of RAD52 and rad22, its counterpart from Schizosaccharomyces pombe, RAD52 homologs from man and mouse were

  19. Critical interaction domains between bloom syndrome protein and RAD51.

    Science.gov (United States)

    Bergeron, Krystal L; Murphy, Eileen L; Brown, Lily W; Almeida, Karen H

    2011-01-01

    The American Cancer Society's 2009 statistics estimate that 1 out of every 4 deaths is cancer related. Genomic instability is a common feature of cancerous states, and an increase in genomic instability is the diagnostic feature of Bloom Syndrome. Bloom Syndrome, a rare disorder characterized by a predisposition to cancer, is caused by mutations of the BLM gene. This study focuses on the partnerships of BLM protein to RAD51, a Homologous Recombination repair protein essential for survival. A systematic set of BLM deletion fragments were generated to refine the protein binding domains of BLM to RAD51 and determine interacting regions of BLM and ssDNA. Results show that RAD51 and ssDNA interact in overlapping regions; BLM₁₀₀₋₂₁₄ and BLM₁₃₁₇₋₁₃₆₇. The overlapping nature of these regions suggests a preferential binding for one partner that could function to regulate homologous recombination and therefore helps to clarify the role of BLM in maintaining genomic stability.

  20. Rapid SNP discovery and genetic mapping using sequenced RAD markers.

    Directory of Open Access Journals (Sweden)

    Nathan A Baird

    Full Text Available Single nucleotide polymorphism (SNP discovery and genotyping are essential to genetic mapping. There remains a need for a simple, inexpensive platform that allows high-density SNP discovery and genotyping in large populations. Here we describe the sequencing of restriction-site associated DNA (RAD tags, which identified more than 13,000 SNPs, and mapped three traits in two model organisms, using less than half the capacity of one Illumina sequencing run. We demonstrated that different marker densities can be attained by choice of restriction enzyme. Furthermore, we developed a barcoding system for sample multiplexing and fine mapped the genetic basis of lateral plate armor loss in threespine stickleback by identifying recombinant breakpoints in F(2 individuals. Barcoding also facilitated mapping of a second trait, a reduction of pelvic structure, by in silico re-sorting of individuals. To further demonstrate the ease of the RAD sequencing approach we identified polymorphic markers and mapped an induced mutation in Neurospora crassa. Sequencing of RAD markers is an integrated platform for SNP discovery and genotyping. This approach should be widely applicable to genetic mapping in a variety of organisms.

  1. RadNet: Open network protocol for radiation data

    Energy Technology Data Exchange (ETDEWEB)

    Rees, B.; Olson, K. [Los Alamos National Lab., NM (United States); Beckes-Talcott, J.; Kadner, S.; Wenderlich, T.; Hoy, M.; Doyle, W. [Aquila Technologies Group, Inc., Albuquerque, NM (United States); Koskelo, M. [Canberra Industries, Meriden, CT (United States)

    1998-12-31

    Safeguards instrumentation is increasingly being incorporated into remote monitoring applications. In the past, vendors of radiation monitoring instruments typically provided the tools for uploading the monitoring data to a host. However, the proprietary nature of communication protocols lends itself to increased computer support needs and increased installation expenses. As a result, a working group of suppliers and customers of radiation monitoring instruments defined an open network protocol for transferring packets on a local area network from radiation monitoring equipment to network hosts. The protocol was termed RadNet. While it is now primarily used for health physics instruments, RadNet`s flexibility and strength make it ideal for remote monitoring of nuclear materials. The incorporation of standard, open protocols ensures that future work will not render present work obsolete; because RadNet utilizes standard Internet protocols, and is itself a non-proprietary standard. The use of industry standards also simplifies the development and implementation of ancillary services, e.g. E-main generation or even pager systems.

  2. Association between RAD 51 rs1801320 and susceptibility to glioblastoma.

    Science.gov (United States)

    Franceschi, S; Tomei, S; Mazzanti, C M; Lessi, F; Aretini, P; La Ferla, M; De Gregorio, V; Pasqualetti, F; Zavaglia, K; Bevilacqua, G; Naccarato, A G

    2016-01-01

    Glioblastoma is the most common and aggressive malignant primary brain tumor. Despite decades of research and the advent of new therapies, patients with glioblastoma continue to have a very poor prognosis. Radiation therapy has a major role as adjuvant treatment for glioblastoma following surgical resection. Many studies have shown that polymorphisms of genes involved in pathways of DNA repair may affect the sensitivity of the cells to treatment. Although the role of these polymorphisms has been investigated in relation to response to radiotherapy, their role as predisposing factors to glioblastoma has not been clarified yet. In the present study, we evaluated the association between polymorphisms in DNA repair genes, namely: XRCC1 rs25487, XRCC3 rs861539 and RAD51 rs1801320, with the susceptibility to develop glioblastoma. Eighty-five glioblastoma patients and 70 matched controls were recruited for this study. Data from the 1000 Genomes Project (98 Tuscans) were also downloaded and used for the association analysis. Subjects carrying RAD51 rs1801320 GC genotype showed an increased risk of glioblastoma (GC vs GG, χ(2) = 10.75; OR 3.0087; p = 0.0010). The C allele was also significantly associated to glioblastoma (χ(2) = 8.66; OR 2.5674; p = 0.0032). Moreover, RAD51 rs1801320 C allele increased the risk to develop glioblastoma also when combined to XRCC1 rs25487 G allele and XRCC3 rs861539 C allele (χ(2) = 6.558; p = 0.0053).

  3. NARAC Dispersion Model Product Integration With RadResponder

    Energy Technology Data Exchange (ETDEWEB)

    Aluzzi, Fernando [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-09-30

    Work on enhanced cooperation and interoperability of Nuclear Incident Response Teams (NIRT) is a joint effort between DHS/FEMA, DOE/NNSA and EPA. One such effort was the integration between the RadResponder Network, a resource sponsored by FEMA for the management of radiological data during an emergency, and the National Atmospheric Advisory Center (NARAC), a DOE/NNSA modeling resource whose predictions are used to aid radiological emergency preparedness and response. Working together under a FEMA-sponsored project these two radiological response assets developed a capability to read and display plume model prediction results from the NARAC computer system in the RadResponder software tool. As a result of this effort, RadResponder users have been provided with NARAC modeling predictions of contamination areas, radiological dose levels, and protective action areas (e.g., areas warranting worker protection or sheltering/evacuation) to help guide protective action decisions and field monitoring surveys, and gain key situation awareness following a radiological/nuclear accident or incident (e.g., nuclear power plant accident, radiological dispersal device incident, or improvised nuclear detonation incident). This document describes the details of this integration effort.

  4. Development of RadRob15, A Robot for Detecting Radioactive Contamination in Nuclear Medicine Departments

    Directory of Open Access Journals (Sweden)

    Shafe A.

    2016-09-01

    Full Text Available Accidental or intentional release of radioactive materials into the living or working environment may cause radioactive contamination. In nuclear medicine departments, radioactive contamination is usually due to radionuclides which emit high energy gamma photons and particles. These radionuclides have a broad range of energies and penetration capabilities. Rapid detection of radioactive contamination is very important for efficient removing of the contamination without spreading the radionuclides. A quick scan of the contaminated area helps health physicists locate the contaminated area and assess the level of activity. Studies performed in IR Iran shows that in some nuclear medicine departments, areas with relatively high levels of activity can be found. The highest contamination level was detected in corridors which are usually used by patients. To monitor radioactive contamination in nuclear medicine departments, RadRob15, a contamination detecting robot was developed in the Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC. The motor vehicle scanner and the gas radiation detector are the main components of this robot. The detection limit of this robot has enabled it to detect low levels of radioactive contamination. Our preliminary tests show that RadRob15 can be easily used in nuclear medicine departments as a device for quick surveys which identifies the presence or absence of radioactive contamination.

  5. Development of RadRob15, A Robot for Detecting Radioactive Contamination in Nuclear Medicine Departments.

    Science.gov (United States)

    Shafe, A; Mortazavi, S M J; Joharnia, A; Safaeyan, Gh H

    2016-09-01

    Accidental or intentional release of radioactive materials into the living or working environment may cause radioactive contamination. In nuclear medicine departments, radioactive contamination is usually due to radionuclides which emit high energy gamma photons and particles. These radionuclides have a broad range of energies and penetration capabilities. Rapid detection of radioactive contamination is very important for efficient removing of the contamination without spreading the radionuclides. A quick scan of the contaminated area helps health physicists locate the contaminated area and assess the level of activity. Studies performed in IR Iran shows that in some nuclear medicine departments, areas with relatively high levels of activity can be found. The highest contamination level was detected in corridors which are usually used by patients. To monitor radioactive contamination in nuclear medicine departments, RadRob15, a contamination detecting robot was developed in the Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC). The motor vehicle scanner and the gas radiation detector are the main components of this robot. The detection limit of this robot has enabled it to detect low levels of radioactive contamination. Our preliminary tests show that RadRob15 can be easily used in nuclear medicine departments as a device for quick surveys which identifies the presence or absence of radioactive contamination.

  6. Rad18 and Rnf8 facilitate homologous recombination by two distinct mechanisms, promoting Rad51 focus formation and suppressing the toxic effect of nonhomologous end joining

    NARCIS (Netherlands)

    Kobayashi, S.; Kasaishi, Y.; Nakada, S.; Takagi, T.; Era, S.; Motegi, A.; Chiu, R. K.; Takeda, S.; Hirota, K.

    2015-01-01

    The E2 ubiquitin conjugating enzyme Ubc13 and the E3 ubiquitin ligases Rad18 and Rnf8 promote homologous recombination (HR)-mediated double-strand break (DSB) repair by enhancing polymerization of the Rad51 recombinase at.-ray-induced DSB sites. To analyze functional interactions between the three

  7. Rad18 and Rnf8 facilitate homologous recombination by two distinct mechanisms, promoting Rad51 focus formation and suppressing the toxic effect of nonhomologous end joining

    NARCIS (Netherlands)

    Kobayashi, S.; Kasaishi, Y.; Nakada, S.; Takagi, T.; Era, S.; Motegi, A.; Chiu, R. K.; Takeda, S.; Hirota, K.

    2015-01-01

    The E2 ubiquitin conjugating enzyme Ubc13 and the E3 ubiquitin ligases Rad18 and Rnf8 promote homologous recombination (HR)-mediated double-strand break (DSB) repair by enhancing polymerization of the Rad51 recombinase at.-ray-induced DSB sites. To analyze functional interactions between the three e

  8. A phosphorylation-deubiquitination cascade regulates the BRCA2-RAD51 axis in homologous recombination.

    Science.gov (United States)

    Luo, Kuntian; Li, Lei; Li, Yunhui; Wu, Chenming; Yin, Yujiao; Chen, Yuping; Deng, Min; Nowsheen, Somaira; Yuan, Jian; Lou, Zhenkun

    2016-12-01

    Homologous recombination (HR) is one of the major DNA double-strand break (DSB) repair pathways in mammalian cells. Defects in HR trigger genomic instability and result in cancer predisposition. The defining step of HR is homologous strand exchange directed by the protein RAD51, which is recruited to DSBs by BRCA2. However, the regulation of the BRCA2-RAD51 axis remains unclear. Here we report that ubiquitination of RAD51 hinders RAD51-BRCA2 interaction, while deubiquitination of RAD51 facilitates RAD51-BRCA2 binding and RAD51 recruitment and thus is critical for proper HR. Mechanistically, in response to DNA damage, the deubiquitinase UCHL3 is phosphorylated and activated by ATM. UCHL3, in turn, deubiquitinates RAD51 and promotes the binding between RAD51 and BRCA2. Overexpression of UCHL3 renders breast cancer cells resistant to radiation and chemotherapy, while depletion of UCHL3 sensitizes cells to these treatments, suggesting a determinant role of UCHL3 in cancer therapy. Overall, we identify UCHL3 as a novel regulator of DNA repair and reveal a model in which a phosphorylation-deubiquitination cascade dynamically regulates the BRCA2-RAD51 pathway. © 2016 Luo et al.; Published by Cold Spring Harbor Laboratory Press.

  9. Caffeine inhibits gene conversion by displacing Rad51 from ssDNA

    Science.gov (United States)

    Tsabar, Michael; Mason, Jennifer M.; Chan, Yuen-Ling; Bishop, Douglas K.; Haber, James E.

    2015-01-01

    Efficient repair of chromosomal double-strand breaks (DSBs) by homologous recombination relies on the formation of a Rad51 recombinase filament that forms on single-stranded DNA (ssDNA) created at DSB ends. This filament facilitates the search for a homologous donor sequence and promotes strand invasion. Recently caffeine treatment has been shown to prevent gene targeting in mammalian cells by increasing non-productive Rad51 interactions between the DSB and random regions of the genome. Here we show that caffeine treatment prevents gene conversion in yeast, independently of its inhibition of the Mec1ATR/Tel1ATM-dependent DNA damage response or caffeine's inhibition of 5′ to 3′ resection of DSB ends. Caffeine treatment results in a dosage-dependent eviction of Rad51 from ssDNA. Gene conversion is impaired even at low concentrations of caffeine, where there is no discernible dismantling of the Rad51 filament. Loss of the Rad51 filament integrity is independent of Srs2's Rad51 filament dismantling activity or Rad51's ATPase activity and does not depend on non-specific Rad51 binding to undamaged double-stranded DNA. Caffeine treatment had similar effects on irradiated HeLa cells, promoting loss of previously assembled Rad51 foci. We conclude that caffeine treatment can disrupt gene conversion by disrupting Rad51 filaments. PMID:26019181

  10. A human monoclonal antibody 264RAD targeting αvβ6 integrin reduces tumour growth and metastasis, and modulates key biomarkers in vivo.

    Science.gov (United States)

    Eberlein, C; Kendrew, J; McDaid, K; Alfred, A; Kang, J S; Jacobs, V N; Ross, S J; Rooney, C; Smith, N R; Rinkenberger, J; Cao, A; Churchman, A; Marshall, J F; Weir, H M; Bedian, V; Blakey, D C; Foltz, I N; Barry, S T

    2013-09-12

    αvβ6 integrin expression is upregulated on a wide range of epithelial tumours, and is thought to play a role in modulating tumour growth. Here we describe a human therapeutic antibody 264RAD, which binds and inhibits αvβ6 integrin function. 264RAD cross-reacts with human, mouse and cynomolgus monkey αvβ6, and inhibits binding to all ligands including the latency-associated peptide of TGF-β. Screening across a range of integrins revealed that 264RAD also binds and inhibits the related integrin αvβ8, but not the integrins α5β1, αvβ3, αvβ5 and α4β1. In vitro 264RAD inhibited invasion of VB6 and Detroit 562 cells in a Matrigel invasion assay and αvβ6 mediated production of matrix metalloproteinase-9 in Calu-3 cells. It inhibited TGF-β-mediated activation of dermal skin fibroblasts by preventing local activation of TGF-β by NCI-H358 tumour cells in a tumour cell-fibroblast co-culture assay. In vivo 264RAD showed dose-dependent inhibition of Detroit 562 tumour growth, regressing established tumours when dosed at 20 mg/kg once weekly. The reduction in growth associated with 264RAD was related to a dose-dependent inhibition of Ki67 and phospho-ERK and a reduction of αvβ6 expression in the tumour cells, coupled to a reduction in fibronectin and alpha smooth muscle actin expression in stromal fibroblasts. 264RAD also reduced the growth and metastasis of orthotopic 4T1 tumours. At 20 mg/kg growth of both the primary tumour and the number of metastatic deposits in lung were reduced. The data support the conclusion that 264RAD is a potent inhibitor of αvβ6 integrin, with some activity against αvβ8 integrin, that reduces both tumour growth and metastasis.

  11. Prostate cancer localization using multiparametric MR imaging: comparison of Prostate Imaging Reporting and Data System (PI-RADS) and Likert scales.

    Science.gov (United States)

    Rosenkrantz, Andrew B; Kim, Sooah; Lim, Ruth P; Hindman, Nicole; Deng, Fang-Ming; Babb, James S; Taneja, Samir S

    2013-11-01

    To compare the recently proposed Prostate Imaging Reporting and Data System (PI-RADS) scale that incorporates fixed criteria and a standard Likert scale based on overall impression in prostate cancer localization using multiparametric magnetic resonance (MR) imaging. This retrospective study was HIPAA compliant and institutional review board approved. Seventy patients who underwent 3-T pelvic MR imaging, including T2-weighted imaging, diffusion-weighted imaging, and dynamic contrast material-enhanced imaging, with a pelvic phased-array coil before radical prostatectomy were included. Three radiologists, each with 6 years of experience, independently scored 18 regions (12 peripheral zone [PZ], six transition zone [TZ]) using PI-RADS (range, scores 3-15) and Likert (range, scores 1-5) scales. Logistic regression for correlated data was used to compare scales for detection of tumors larger than 3 mm in maximal diameter at prostatectomy. Maximal accuracy was achieved with score thresholds of 8 and higher and of 3 and higher for PI-RADS and Likert scales, respectively. At these thresholds, in the PZ, similar accuracy was achieved with the PI-RADS scale and the Likert scale for radiologist 1 (89.0% vs 88.2%, P = .223) and radiologist 3 (88.5% vs 88.2%, P = .739) and greater accuracy was achieved with the PI-RADS scale than the Likert scale for radiologist 2 (89.6% vs 87.1%, P = .008). In the TZ, accuracy was lower with the PI-RADS scale than with the Likert scale for radiologist 1 (70.0% vs 87.1%, P scale than with the Likert scale for radiologist 1 (88.6% vs 82.6%, P = .032), and sensitivity was similar for radiologist 2 (78.0% vs 76.5, P = .467) and radiologist 3 (77.3% vs 81.1%, P = .125). Radiologists performed well with both PI-RADS and Likert scales for tumor localization, although, in the TZ, performance was better with the Likert scale than the PI-RADS scale. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13122233/-/DC1. RSNA, 2013

  12. Effects of mTOR Inhibitor Everolimus (RAD001) on Bladder Cancer Cells

    Science.gov (United States)

    Chiong, Edmund; Lee, I-Ling; Dadbin, Ali; Sabichi, Anita L; Harris, Loleta; Urbauer, Diana; McConkey, David; Dickstein, Rian Jason; Cheng, Tiewei; Grossman, H. Barton

    2014-01-01

    Purpose We investigated the effect of the mTOR inhibitor everolimus (RAD001) on human bladder cancer (BC) cells in vitro and in vivo. Experimental Design The effect of RAD001 on the growth of UM-UC-3, UM-UC-6, UM-UC-9, and UM-UC-14 BC cells were assessed by crystal violet and [3H]Thymidine incorporation assays . Flow cytometry cell cycle analyses were performed to measure the apoptotic cell fraction. Protein synthesis was measured using tritium-labeled leucine–incorporation assays. The effects of RAD001 on the mTOR pathway were analyzed by western blotting. To test the effects of RAD001 in vivo, UM-UC-3, UM-UC-6, and UMUC-9 cells were subcutaneously implanted into nude mice. Tumor-bearing mice were treated orally with RAD001 or placebo. Tumors were harvested for immunohistochemical analysis. Results In vitro, RAD001 transiently inhibited BC cell growth in a dose-dependent manner. This effect was augmented by retreatment of cells after 3 days. UM-UC-14 cells were the most sensitive to RAD001, while UM-UC-9 cells were the least sensitive. After retreatment with RAD001, only sensitive cell lines showed G1 phase arrest, with no evidence of apoptosis. RAD001 significantly inhibited the growth of tumors that were subcutaneously implanted in mice. Inhibition of protein synthesis through the S6K and 4E-BP1 pathways appears to be the main mechanism for the RAD001-induced growth inhibition. However, inhibition of angiogenesis was the predominant mechanism of RAD001's effect on UM-UC-9 cells. Conclusions The mTOR inhibitor RAD001 inhibits growth of BC cells in vitro. RAD001 is effective in treating BC tumors in an in vivo nude mouse model despite the heterogeneity of in vitro responses. PMID:21415218

  13. A Rad53 independent function of Rad9 becomes crucial for genome maintenance in the absence of the Recq helicase Sgs1.

    Directory of Open Access Journals (Sweden)

    Ida Nielsen

    Full Text Available The conserved family of RecQ DNA helicases consists of caretaker tumour suppressors, that defend genome integrity by acting on several pathways of DNA repair that maintain genome stability. In budding yeast, Sgs1 is the sole RecQ helicase and it has been implicated in checkpoint responses, replisome stability and dissolution of double Holliday junctions during homologous recombination. In this study we investigate a possible genetic interaction between SGS1 and RAD9 in the cellular response to methyl methane sulphonate (MMS induced damage and compare this with the genetic interaction between SGS1 and RAD24. The Rad9 protein, an adaptor for effector kinase activation, plays well-characterized roles in the DNA damage checkpoint response, whereas Rad24 is characterized as a sensor protein also in the DNA damage checkpoint response. Here we unveil novel insights into the cellular response to MMS-induced damage. Specifically, we show a strong synergistic functionality between SGS1 and RAD9 for recovery from MMS induced damage and for suppression of gross chromosomal rearrangements, which is not the case for SGS1 and RAD24. Intriguingly, it is a Rad53 independent function of Rad9, which becomes crucial for genome maintenance in the absence of Sgs1. Despite this, our dissection of the MMS checkpoint response reveals parallel, but unequal pathways for Rad53 activation and highlights significant differences between MMS- and hydroxyurea (HU-induced checkpoint responses with relation to the requirement of the Sgs1 interacting partner Topoisomerase III (Top3. Thus, whereas earlier studies have documented a Top3-independent role of Sgs1 for an HU-induced checkpoint response, we show here that upon MMS treatment, Sgs1 and Top3 together define a minor but parallel pathway to that of Rad9.

  14. Application of RAD-based phylogenetics to complex relationships among variously related taxa in a species flock.

    Science.gov (United States)

    Takahashi, Tetsumi; Nagata, Nobuaki; Sota, Teiji

    2014-11-01

    Restriction site-associated DNA (RAD) sequences from entire genomes can be used to resolve complex phylogenetic problems. However, the processed data matrix varies depending on the strategies used to determine orthologous loci and to filter loci according to the number of taxa with sequence data for the loci, and often contains plenty of missing data. To explore the utility of RAD sequences for elucidating the phylogenetics of variously related species, we conducted RAD sequencing for the Ohomopterus ground beetles and attempted maximum-likelihood phylogenetic analyses using 42 data matrices ranging from 1.6×10(4) to 8.1×10(6) base pairs, with 11-72% missing data. We demonstrate that robust phylogenetic trees, in terms of bootstrap values, do not necessarily result from larger data matrices, as previously suggested. Robust trees for distantly related and closely related taxa resulted from different data matrices, and topologically different robust trees for distantly related taxa resulted from various data matrices. For closely related taxa, moderately large data matrices strongly supported a topology that is incompatible with morphological evidence, possibly due to the effect of introgressive hybridization. Practically, exploring variously prepared data matrices is an effective way to propose important alternative phylogenetic hypotheses for this study group.

  15. SNP discovery using Paired-End RAD-tag sequencing on pooled genomic DNA of Sisymbrium austriacum (Brassicaceae).

    Science.gov (United States)

    Vandepitte, K; Honnay, O; Mergeay, J; Breyne, P; Roldán-Ruiz, I; De Meyer, T

    2013-03-01

    Single nucleotide polymorphisms SNPs are rapidly replacing anonymous markers in population genomic studies, but their use in non model organisms is hampered by the scarcity of cost-effective approaches to uncover genome-wide variation in a comprehensive subset of individuals. The screening of one or only a few individuals induces ascertainment bias. To discover SNPs for a population genomic study of the Pyrenean rocket (Sisymbrium austriacum subsp. chrysanthum), we undertook a pooled RAD-PE (Restriction site Associated DNA Paired-End sequencing) approach. RAD tags were generated from the PstI-digested pooled genomic DNA of 12 individuals sampled across the species distribution range and paired-end sequenced using Illumina technology to produce ~24.5 Mb of sequences, covering ~7% of the specie's genome. Sequences were assembled into ~76 000 contigs with a mean length of 323 bp (N(50)  = 357 bp, sequencing depth = 24x). In all, >15 000 SNPs were called, of which 47% were annotated in putative genic regions based on homology with the Arabidopsis thaliana genome. Gene ontology (GO) slim categorization demonstrated that the identified SNPs covered extant genic variation well. The validation of 300 SNPs on a larger set of individuals using a KASPar assay underpinned the utility of pooled RAD-PE as an inexpensive genome-wide SNP discovery technique (success rate: 87%). In addition to SNPs, we discovered >600 putative SSR markers.

  16. Conduction electron spin resonance in the α-Yb1-xFexAlB4 (0 ⩽ x ⩽ 0.50) and α-LuAlB4 compounds

    Science.gov (United States)

    Holanda, L. M.; Lesseux, G. G.; Magnavita, E. T.; Ribeiro, R. A.; Nakatsuji, S.; Kuga, K.; Fisk, Z.; Oseroff, S. B.; Urbano, R. R.; Rettori, C.; Pagliuso, P. G.

    2015-06-01

    β-YbAlB4 has become one of the most studied heavy fermion systems since its discovery due to its remarkable physical properties. This system is the first reported Yb-based heavy-fermion superconductor (HFS) for which the low-T superconducting state emerges from a non-fermi-liquid (NFL) normal state associated with quantum criticality Nakatsuji et al 2008 Nature 4 603. Additionally, it presents a striking and unprecedented electron spin resonance (ESR) signal which behaves as a conduction electron spin resonance (CESR) at high temperatures and acquires features of the Yb3+ local moment ESR at low temperatures. The latter, also named Kondo quasiparticles spin resonance (KQSR), has been defined as a 4f-ce strongly coupled ESR mode that behaves as a local probe of the Kondo quasiparticles in a quantum critical regime, Holanda et al 2011 Phys. Rev. Lett. 107 026402. Interestingly, β-YbAlB4 possesses a previously known structural variant, namely the α-YbAlB4, phase which is a paramagnetic Fermi liquid (FL) at low temperatures Macaluso et al 2007 Chem. Mater. 19 1918. However, it has been recently suggested that the α-YbAlB4 phase may be tuned to NFL behavior and/or magnetic ordering as the compound is doped with Fe. Here we report ESR studies on the α-Yb1-xFexAlB4 (0 ⩽ x ⩽ 0.50) series as well as on the reference compound α-LuAlB4. For all measured samples, the observed ESR signal behaves as a CESR in the entire temperature range (10 K ≲ T ≲ 300 K) in clear contrast with what has been observed for β-YbAlB4. This striking result indicates that the proximity to a quantum critical point is crucial to the occurrence of a KQSR signal.

  17. Conduction electron spin resonance in the α-Yb1-xFexAlB4 (0 ⩽ x ⩽ 0.50) and α-LuAlB4 compounds.

    Science.gov (United States)

    Holanda, L M; Lesseux, G G; Magnavita, E T; Ribeiro, R A; Nakatsuji, S; Kuga, K; Fisk, Z; Oseroff, S B; Urbano, R R; Rettori, C; Pagliuso, P G

    2015-07-01

    β-YbAlB4 has become one of the most studied heavy fermion systems since its discovery due to its remarkable physical properties. This system is the first reported Yb-based heavy-fermion superconductor (HFS) for which the low-T superconducting state emerges from a non-fermi-liquid (NFL) normal state associated with quantum criticality Nakatsuji et al 2008 Nature 4 603. Additionally, it presents a striking and unprecedented electron spin resonance (ESR) signal which behaves as a conduction electron spin resonance (CESR) at high temperatures and acquires features of the Yb(3+) local moment ESR at low temperatures. The latter, also named Kondo quasiparticles spin resonance (KQSR), has been defined as a 4f-ce strongly coupled ESR mode that behaves as a local probe of the Kondo quasiparticles in a quantum critical regime, Holanda et al 2011 Phys. Rev. Lett. 107 026402. Interestingly, β-YbAlB4 possesses a previously known structural variant, namely the α-YbAlB4, phase which is a paramagnetic Fermi liquid (FL) at low temperatures Macaluso et al 2007 Chem. Mater. 19 1918. However, it has been recently suggested that the α-YbAlB4 phase may be tuned to NFL behavior and/or magnetic ordering as the compound is doped with Fe. Here we report ESR studies on the α-Yb1-xFexAlB4 (0 ⩽ x ⩽ 0.50) series as well as on the reference compound α-LuAlB4. For all measured samples, the observed ESR signal behaves as a CESR in the entire temperature range (10 K ≲ T ≲ 300 K) in clear contrast with what has been observed for β-YbAlB4. This striking result indicates that the proximity to a quantum critical point is crucial to the occurrence of a KQSR signal.

  18. Comparison of Martian Surface Radiation Predictions to the Measurements of Mars Science Laboratory Radiation Assessment Detector (MSL/RAD)

    Science.gov (United States)

    Kim, Myung-Hee Y.; Cucinotta, Francis A.; Zeitlin, Cary; Hassler, Donald M.; Ehresmann, Bent; Rafkin, Scot C. R.; Wimmer-Schweingruber, Robert F; Boettcher, Stephan; Boehm, Eckart; Guo, Jingnan; hide

    2014-01-01

    For the analysis of radiation risks to astronauts and planning exploratory space missions, detailed knowledge of particle spectra is an important factor. Detailed measurements of the energetic particle radiation environment on the surface of Mars have been made by the Mars Science Laboratory Radiation Assessment Detector (MSL-RAD) on the Curiosity rover since August 2012, and particle fluxes for a wide range of ion species (up to several hundred MeV/u) and high energy neutrons (8 - 1000 MeV) have been available for the first 200 sols. Although the data obtained on the surface of Mars for 200 sols are limited in the narrow energy spectra, the simulation results using the Badhwar-O'Neill galactic cosmic ray (GCR) environment model and the high-charge and energy transport (HZETRN) code are compared to the data. For the nuclear interactions of primary GCR through Mars atmosphere and Curiosity rover, the quantum multiple scattering theory of nuclear fragmentation (QMSFRG) is used, which includes direct knockout, evaporation and nuclear coalescence. Daily atmospheric pressure measurements at Gale Crater by the MSL Rover Environmental Monitoring Station are implemented into transport calculations for describing the daily column depth of atmosphere. Particles impinging on top of the Martian atmosphere reach the RAD after traversing varying depths of atmosphere that depend on the slant angles, and the model accounts for shielding of the RAD by the rest of the instrument. Calculations of stopping particle spectra are in good agreement with the RAD measurements for the first 200 sols by accounting changing heliospheric conditions and atmospheric pressure. Detailed comparisons between model predictions and spectral data of various particle types provide the validation of radiation transport models, and thus increase the accuracy of the predictions of future radiation environments on Mars. These contributions lend support to the understanding of radiation health risks to

  19. Mek1 Down Regulates Rad51 Activity during Yeast Meiosis by Phosphorylation of Hed1.

    Science.gov (United States)

    Callender, Tracy L; Laureau, Raphaelle; Wan, Lihong; Chen, Xiangyu; Sandhu, Rima; Laljee, Saif; Zhou, Sai; Suhandynata, Ray T; Prugar, Evelyn; Gaines, William A; Kwon, YoungHo; Börner, G Valentin; Nicolas, Alain; Neiman, Aaron M; Hollingsworth, Nancy M

    2016-08-01

    During meiosis, programmed double strand breaks (DSBs) are repaired preferentially between homologs to generate crossovers that promote proper chromosome segregation at Meiosis I. In many organisms, there are two strand exchange proteins, Rad51 and the meiosis-specific Dmc1, required for interhomolog (IH) bias. This bias requires the presence, but not the strand exchange activity of Rad51, while Dmc1 is responsible for the bulk of meiotic recombination. How these activities are regulated is less well established. In dmc1Δ mutants, Rad51 is actively inhibited, thereby resulting in prophase arrest due to unrepaired DSBs triggering the meiotic recombination checkpoint. This inhibition is dependent upon the meiosis-specific kinase Mek1 and occurs through two different mechanisms that prevent complex formation with the Rad51 accessory factor Rad54: (i) phosphorylation of Rad54 by Mek1 and (ii) binding of Rad51 by the meiosis-specific protein Hed1. An open question has been why inhibition of Mek1 affects Hed1 repression of Rad51. This work shows that Hed1 is a direct substrate of Mek1. Phosphorylation of Hed1 at threonine 40 helps suppress Rad51 activity in dmc1Δ mutants by promoting Hed1 protein stability. Rad51-mediated recombination occurring in the absence of Hed1 phosphorylation results in a significant increase in non-exchange chromosomes despite wild-type levels of crossovers, confirming previous results indicating a defect in crossover assurance. We propose that Rad51 function in meiosis is regulated in part by the coordinated phosphorylation of Rad54 and Hed1 by Mek1.

  20. Mek1 Down Regulates Rad51 Activity during Yeast Meiosis by Phosphorylation of Hed1.

    Directory of Open Access Journals (Sweden)

    Tracy L Callender

    2016-08-01

    Full Text Available During meiosis, programmed double strand breaks (DSBs are repaired preferentially between homologs to generate crossovers that promote proper chromosome segregation at Meiosis I. In many organisms, there are two strand exchange proteins, Rad51 and the meiosis-specific Dmc1, required for interhomolog (IH bias. This bias requires the presence, but not the strand exchange activity of Rad51, while Dmc1 is responsible for the bulk of meiotic recombination. How these activities are regulated is less well established. In dmc1Δ mutants, Rad51 is actively inhibited, thereby resulting in prophase arrest due to unrepaired DSBs triggering the meiotic recombination checkpoint. This inhibition is dependent upon the meiosis-specific kinase Mek1 and occurs through two different mechanisms that prevent complex formation with the Rad51 accessory factor Rad54: (i phosphorylation of Rad54 by Mek1 and (ii binding of Rad51 by the meiosis-specific protein Hed1. An open question has been why inhibition of Mek1 affects Hed1 repression of Rad51. This work shows that Hed1 is a direct substrate of Mek1. Phosphorylation of Hed1 at threonine 40 helps suppress Rad51 activity in dmc1Δ mutants by promoting Hed1 protein stability. Rad51-mediated recombination occurring in the absence of Hed1 phosphorylation results in a significant increase in non-exchange chromosomes despite wild-type levels of crossovers, confirming previous results indicating a defect in crossover assurance. We propose that Rad51 function in meiosis is regulated in part by the coordinated phosphorylation of Rad54 and Hed1 by Mek1.

  1. RadMAP: The Radiological Multi-sensor Analysis Platform

    Science.gov (United States)

    Bandstra, Mark S.; Aucott, Timothy J.; Brubaker, Erik; Chivers, Daniel H.; Cooper, Reynold J.; Curtis, Joseph C.; Davis, John R.; Joshi, Tenzing H.; Kua, John; Meyer, Ross; Negut, Victor; Quinlan, Michael; Quiter, Brian J.; Srinivasan, Shreyas; Zakhor, Avideh; Zhang, Richard; Vetter, Kai

    2016-12-01

    The variability of gamma-ray and neutron background during the operation of a mobile detector system greatly limits the ability of the system to detect weak radiological and nuclear threats. The natural radiation background measured by a mobile detector system is the result of many factors, including the radioactivity of nearby materials, the geometric configuration of those materials and the system, the presence of absorbing materials, and atmospheric conditions. Background variations tend to be highly non-Poissonian, making it difficult to set robust detection thresholds using knowledge of the mean background rate alone. The Radiological Multi-sensor Analysis Platform (RadMAP) system is designed to allow the systematic study of natural radiological background variations and to serve as a development platform for emerging concepts in mobile radiation detection and imaging. To do this, RadMAP has been used to acquire extensive, systematic background measurements and correlated contextual data that can be used to test algorithms and detector modalities at low false alarm rates. By combining gamma-ray and neutron detector systems with data from contextual sensors, the system enables the fusion of data from multiple sensors into novel data products. The data are curated in a common format that allows for rapid querying across all sensors, creating detailed multi-sensor datasets that are used to study correlations between radiological and contextual data, and develop and test novel techniques in mobile detection and imaging. In this paper we will describe the instruments that comprise the RadMAP system, the effort to curate and provide access to multi-sensor data, and some initial results on the fusion of contextual and radiological data.

  2. RAD52 Facilitates Mitotic DNA Synthesis Following Replication Stress

    DEFF Research Database (Denmark)

    Bhowmick, Rahul; Minocherhomji, Sheroy; Hickson, Ian D

    2016-01-01

    Homologous recombination (HR) is necessary to counteract DNA replication stress. Common fragile site (CFS) loci are particularly sensitive to replication stress and undergo pathological rearrangements in tumors. At these loci, replication stress frequently activates DNA repair synthesis in mitosis....... This mitotic DNA synthesis, termed MiDAS, requires the MUS81-EME1 endonuclease and a non-catalytic subunit of the Pol-delta complex, POLD3. Here, we examine the contribution of HR factors in promoting MiDAS in human cells. We report that RAD51 and BRCA2 are dispensable for MiDAS but are required to counteract...

  3. Rapid and cost-effective polymorphism identification and genotyping using restriction site associated DNA (RAD) markers.

    Science.gov (United States)

    Miller, Michael R; Dunham, Joseph P; Amores, Angel; Cresko, William A; Johnson, Eric A

    2007-02-01

    Restriction site associated DNA (RAD) tags are a genome-wide representation of every site of a particular restriction enzyme by short DNA tags. Most organisms segregate large numbers of DNA sequence polymorphisms that disrupt restriction sites, which allows RAD tags to serve as genetic markers spread at a high density throughout the genome. Here, we demonstrate the applicability of RAD markers for both individual and bulk-segregant genotyping. First, we show that these markers can be identified and typed on pre-existing microarray formats. Second, we present a method that uses RAD marker DNA to rapidly produce a low-cost microarray genotyping resource that can be used to efficiently identify and type thousands of RAD markers. We demonstrate the utility of the former approach by using a tiling path array for the fruit fly to map a recombination breakpoint, and the latter approach by creating and using an enriched RAD marker array for the threespine stickleback. The high number of RAD markers enabled localization of a previously identified region, as well as a second region also associated with the lateral plate phenotype. Taken together, our results demonstrate that RAD markers, and the method to develop a RAD marker microarray resource, allow high-throughput, high-resolution genotyping in both model and nonmodel systems.

  4. Functional and Physical Interaction between Rad24 and Rfc5 in the Yeast Checkpoint Pathways

    OpenAIRE

    Shimomura, Toshiyasu; Ando, Seiko; Matsumoto, Kunihiro; Sugimoto, Katsunori

    1998-01-01

    The RFC5 gene encodes a small subunit of replication factor C (RFC) complex in Saccharomyces cerevisiae and has been shown to be required for the checkpoints which respond to replication block and DNA damage. Here we describe the isolation of RAD24, known to play a role in the DNA damage checkpoint, as a dosage-dependent suppressor of rfc5-1. RAD24 overexpression suppresses the sensitivity of rfc5-1 cells to DNA-damaging agents and the defect in DNA damage-induced Rad53 phosphorylation. Rad24...

  5. Structure of the single-strand annealing domain of human RAD52 protein

    OpenAIRE

    Singleton, Martin R.; Wentzell, Lois M.; Liu, Yilun; West, Stephen C.; Wigley, Dale B.

    2002-01-01

    In eukaryotic cells, RAD52 protein plays a central role in genetic recombination and DNA repair by (i) promoting the annealing of complementary single-stranded DNA and (ii) stimulation of the RAD51 recombinase. The single-strand annealing domain resides in the N-terminal region of the protein and is highly conserved, whereas the nonconserved RAD51-interaction domain is located in the C-terminal region. An N-terminal fragment of human RAD52 (residues 1–209) has been purified to homogeneity and...

  6. The epistatic relationship between BRCA2 and the other RAD51 mediators in homologous recombination.

    Directory of Open Access Journals (Sweden)

    Yong Qing

    2011-07-01

    Full Text Available RAD51 recombinase polymerizes at the site of double-strand breaks (DSBs where it performs DSB repair. The loss of RAD51 causes extensive chromosomal breaks, leading to apoptosis. The polymerization of RAD51 is regulated by a number of RAD51 mediators, such as BRCA1, BRCA2, RAD52, SFR1, SWS1, and the five RAD51 paralogs, including XRCC3. We here show that brca2-null mutant cells were able to proliferate, indicating that RAD51 can perform DSB repair in the absence of BRCA2. We disrupted the BRCA1, RAD52, SFR1, SWS1, and XRCC3 genes in the brca2-null cells. All the resulting double-mutant cells displayed a phenotype that was very similar to that of the brca2-null cells. We suggest that BRCA2 might thus serve as a platform to recruit various RAD51 mediators at the appropriate position at the DNA-damage site.

  7. A mRad51-GFP antimorphic allele affects homologous recombination and DNA damage sensitivity.

    Science.gov (United States)

    Uringa, Evert-Jan; Baldeyron, Céline; Odijk, Hanny; Wassenaar, Evelyne; van Cappellen, Wiggert A; Maas, Alex; Hoeijmakers, Jan H J; Baarends, Willy M; Kanaar, Roland; Essers, Jeroen

    2015-01-01

    Accurate DNA double-strand break repair through homologous recombination is essential for preserving genome integrity. Disruption of the gene encoding RAD51, the protein that catalyzes DNA strand exchange during homologous recombination, results in lethality of mammalian cells. Proteins required for homologous recombination, also play an important role during DNA replication. To explore the role of RAD51 in DNA replication and DSB repair, we used a knock-in strategy to express a carboxy-terminal fusion of green fluorescent protein to mouse RAD51 (mRAD51-GFP) in mouse embryonic stem cells. Compared to wild-type cells, heterozygous mRad51(+/wt-GFP) embryonic stem cells showed increased sensitivity to DNA damage induced by ionizing radiation and mitomycin C. Moreover, gene targeting was found to be severely impaired in mRad51(+/wt-GFP) embryonic stem cells. Furthermore, we found that mRAD51-GFP foci were not stably associated with chromatin. From these experiments we conclude that this mRad51-GFP allele is an antimorphic allele. When this allele is present in a heterozygous condition over wild-type mRad51, embryonic stem cells are proficient in DNA replication but display defects in homologous recombination and DNA damage repair. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Cellular localization of mitotic RAD21 with repetitive amino acid motifs in Allium cepa.

    Science.gov (United States)

    Suzuki, Go; Nishiuchi, Chikage; Tsuru, Asami; Kako, Eri; Li, Jian; Yamamoto, Maki; Mukai, Yasuhiko

    2013-02-10

    Onion can be used in experimental observation of mitotic cell division in plant science because its chromosome is large and easy to observe. However, molecular genetic studies are difficult in onion because of its large genome size, and only limited information of onion genes has been available to date. Here we cloned and characterized an onion homologue of mitotic RAD21 gene, AcRAD21-1, to develop a molecular marker of mitosis. The N-terminal, middle, and C-terminal regions of deduced AcRAD21-1 protein sequence were conserved with Arabidopsis SYN4/AtRAD21.3 and rice OsRAD21-1, whereas three characteristic types of repetitive motifs (Repeat-1, Repeat-2/2', and Repeat-3) were observed between the conserved regions. Such inserted repetitive amino acid sequences enlarge the AcRAD21-1 protein into almost 200 kDa, which belongs to the largest class of plant proteins. Genomic organization of the AcRAD21-1 locus was also determined, and the possibility of tandem exon duplication in Repeat-2 was revealed. Subsequently, the polyclonal antiserum was raised against the N-terminal region of AcRAD21-1, and purified by affinity chromatography. Immunohistochemical analysis with the purified antibody successfully showed localization of AcRAD21-1 in onion mitosis, suggesting that it can be used as a molecular marker visualizing dynamic movement of cohesin.

  9. ATP-driven Rad50 conformations regulate DNA tethering, end resection, and ATM checkpoint signaling.

    Science.gov (United States)

    Deshpande, Rajashree A; Williams, Gareth J; Limbo, Oliver; Williams, R Scott; Kuhnlein, Jeff; Lee, Ji-Hoon; Classen, Scott; Guenther, Grant; Russell, Paul; Tainer, John A; Paull, Tanya T

    2014-03-03

    The Mre11-Rad50 complex is highly conserved, yet the mechanisms by which Rad50 ATP-driven states regulate the sensing, processing and signaling of DNA double-strand breaks are largely unknown. Here we design structure-based mutations in Pyrococcus furiosus Rad50 to alter protein core plasticity and residues undergoing ATP-driven movements within the catalytic domains. With this strategy we identify Rad50 separation-of-function mutants that either promote or destabilize the ATP-bound state. Crystal structures, X-ray scattering, biochemical assays, and functional analyses of mutant PfRad50 complexes show that the ATP-induced 'closed' conformation promotes DNA end binding and end tethering, while hydrolysis-induced opening is essential for DNA resection. Reducing the stability of the ATP-bound state impairs DNA repair and Tel1 (ATM) checkpoint signaling in Schizosaccharomyces pombe, double-strand break resection in Saccharomyces cerevisiae, and ATM activation by human Mre11-Rad50-Nbs1 in vitro, supporting the generality of the P. furiosus Rad50 structure-based mutational analyses. These collective results suggest that ATP-dependent Rad50 conformations switch the Mre11-Rad50 complex between DNA tethering, ATM signaling, and 5' strand resection, revealing molecular mechanisms regulating responses to DNA double-strand breaks.

  10. Regulated expression of the Saccharomyces cerevisiae DNA repair gene RAD7 in response to DNA damage and during sporulation.

    Science.gov (United States)

    Jones, J S; Prakash, L; Prakash, S

    1990-06-11

    The RAD7 gene of Saccharomyces cerevisiae affects the proficiency of excision repair of DNA damaged by UV light. Here, we report our studies on the regulation of the RAD7 gene in response to UV irradiation and during sporulation. RAD7 transcript levels increased 6-fold within 40 min of exposure of cells to 37 J/m2 of UV light. Higher UV doses also elicited rapid increases in the level of RAD7 mRNA. RAD7 mRNA levels increased in sporulating MATa/MAT alpha diploid cells, but not in the asporogenous MATa/MATa strain exposed to sporulation conditions. The increase in RAD7 mRNA level in MATa/MAT alpha cells was 15-fold after 6 h and 9-fold after 7 h in sporulation medium; thereafter, RAD7 mRNA levels declined. Periodic transcription of RAD7 during sporulation suggests a role for RAD7 in this process.

  11. Role of teh Rad52 Amino-terminal DNA Binding Activity in DNA Strand Capture in Homologous Recombination

    DEFF Research Database (Denmark)

    Shi, Idina; Hallwyl, Swee Chuang Lim; Seong, Changhyun

    2009-01-01

    Saccharomyces cerevisiae Rad52 protein promotes homologous recombination by nucleating the Rad51 recombinase onto replication protein A-coated single-stranded DNA strands and also by directly annealing such strands. We show that the purified rad52-R70A mutant protein, with a compromised amino...... conversion intermediates reveals that rad52-R70A cells can mediate DNA strand invasion but are unable to complete the recombination event. These results provide evidence that DNA binding by the evolutionarily conserved amino terminus of Rad52 is needed for the capture of the second DNA end during homologous......-terminal DNA binding domain, is capable of Rad51 delivery to DNA but is deficient in DNA annealing. Results from chromatin immunoprecipitation experiments find that rad52-R70A associates with DNA double-strand breaks and promotes recruitment of Rad51 as efficiently as wild-type Rad52. Analysis of gene...

  12. Evaluation of BICRON NE MCP DXT-RAD passive extremity dosemeter

    CERN Document Server

    Yuen, P S; Frketich, G; Rotunda, J

    1999-01-01

    Passive extremity dosemeters currently used in dosimetry communities worldwide have shortcomings. In general, an extremity dosemeter has too thick a detector element, and the dosemeter response is highly energy dependent for beta rays with energies ranging from 200 keV to 2 MeV. It often does not have dosemeter identification, causing problems in the chain of custody. It is often read manually, rendering reading/packing operations very labour intensive. As a result of collaboration between AECL and BICRON NE, a new extremity dosemeter, incorporating a highly sensitive LiF:Mg,Cu,P TLD and tentatively code named MCP DXT-RAD, was developed. It has been evaluated for radiological performance against an ISO draft standard for extremity dosemeters in twelve categories: homogeneity, detection threshold, beta ray energy response, beta angular response, photon energy response, photon angular response, reproducibility, stability under various climatic conditions, linearity, residue, self irradiation, and effect of ligh...

  13. Upward- directed charged particle flux detection in the MSL/RAD instrument

    Science.gov (United States)

    Appel, Jan Kristoffer; Zeitlin, Cary; Koehler, Jan; Hassler, Donald M.; Rafkin, Scot; Guo, Jingnan; Ehresmann, Bent; Wimmer-Schweingruber, Robert; Matthiä, Daniel; Lohf, Henning

    2016-07-01

    The Mars Science Laboratory rover Curiosity, operating on the surface of Mars, is exposed to radiation fluxes from above and below. Galactic Cosmic Rays travel through the Martian atmosphere, producing a modified spectrum consisting of both primary and secondary particles at ground level. These particles produce an upward- directed secondary particle spectrum as they interact with the Martian soil.These upward- directed particles then pass through the rover and enter the Radiation Assessment Detector onboard the rover from below. Here, we characterize the upward- and downward- directed spectra measured by the detector through a combination of GEANT4 and Planetocosmics simulations. We develop and demonstrate a method to discriminate between upward- and downward- directed particle fluxes during the MSL cruise phase to Mars and the surface science phase. This method enables us to extend the energy range and directionality of RAD beyond its design limits.

  14. Differential roles of XRCC2 in S-phase RAD51 focus formation induced by DNA replication inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Lim, C; Liu, N

    2004-05-14

    RAD51 proteins accumulate in discrete nuclear foci in response to DNA damage. Previous studies demonstrated that human RAD51 paralogs (RAD51B, RAD51C, RAD51D, XRCC2 and XRCC3) are essential for the assembly of RAD51 foci induced by ionizing radiation and cross-linking agents. Here we report that XRCC2 also plays important roles in RAD51 focus formation induced by replication arrest during S-phase of cell cycle. In wild-type hamster V79 cells treated with hydroxyurea (HU), RAD51 protein form punctuate nuclear foci, accompanied by increased RAD51 protein level in both cytoplasmic and nuclear fractions, and increased association of RAD51 with chromatin. In contrast, xrcc2 hamster mutant irs1 cells are deficient in the formation of RAD51 foci after HU treatment, suggesting that the function of XRCC2 is required for the assembly of RAD51 at HU-induced stalled replication forks. Interestingly, we found that irs1 cells are able to form intact RAD51 foci in S-phase cells treated with thymidine (TR) or aphidicolin, although irs1 cells are hypersensitive to both HU and TR. Our findings suggest that there may be two distinct pathways (XRCC2-dependent or XRCC2-independent) involved in loading of RAD51 onto stalled replication forks, probably depending upon the structure of DNA lesions.

  15. Oak Ridge Reservation Environmental Protection Rad Neshaps Radionuclide Inventory Web Database and Rad Neshaps Source and Dose Database.

    Science.gov (United States)

    Scofield, Patricia A; Smith, Linda L; Johnson, David N

    2017-07-01

    The U.S. Environmental Protection Agency promulgated national emission standards for emissions of radionuclides other than radon from US Department of Energy facilities in Chapter 40 of the Code of Federal Regulations (CFR) 61, Subpart H. This regulatory standard limits the annual effective dose that any member of the public can receive from Department of Energy facilities to 0.1 mSv. As defined in the preamble of the final rule, all of the facilities on the Oak Ridge Reservation, i.e., the Y-12 National Security Complex, Oak Ridge National Laboratory, East Tennessee Technology Park, and any other U.S. Department of Energy operations on Oak Ridge Reservation, combined, must meet the annual dose limit of 0.1 mSv. At Oak Ridge National Laboratory, there are monitored sources and numerous unmonitored sources. To maintain radiological source and inventory information for these unmonitored sources, e.g., laboratory hoods, equipment exhausts, and room exhausts not currently venting to monitored stacks on the Oak Ridge National Laboratory campus, the Environmental Protection Rad NESHAPs Inventory Web Database was developed. This database is updated annually and is used to compile emissions data for the annual Radionuclide National Emission Standards for Hazardous Air Pollutants (Rad NESHAPs) report required by 40 CFR 61.94. It also provides supporting documentation for facility compliance audits. In addition, a Rad NESHAPs source and dose database was developed to import the source and dose summary data from Clean Air Act Assessment Package-1988 computer model files. This database provides Oak Ridge Reservation and facility-specific source inventory; doses associated with each source and facility; and total doses for the Oak Ridge Reservation dose.

  16. JPIC-Rad-Hard JPEG2000 Image Compression ASIC

    Science.gov (United States)

    Zervas, Nikos; Ginosar, Ran; Broyde, Amitai; Alon, Dov

    2010-08-01

    JPIC is a rad-hard high-performance image compression ASIC for the aerospace market. JPIC implements tier 1 of the ISO/IEC 15444-1 JPEG2000 (a.k.a. J2K) image compression standard [1] as well as the post compression rate-distortion algorithm, which is part of tier 2 coding. A modular architecture enables employing a single JPIC or multiple coordinated JPIC units. JPIC is designed to support wide data sources of imager in optical, panchromatic and multi-spectral space and airborne sensors. JPIC has been developed as a collaboration of Alma Technologies S.A. (Greece), MBT/IAI Ltd (Israel) and Ramon Chips Ltd (Israel). MBT IAI defined the system architecture requirements and interfaces, The JPEG2K-E IP core from Alma implements the compression algorithm [2]. Ramon Chips adds SERDES interfaces and host interfaces and integrates the ASIC. MBT has demonstrated the full chip on an FPGA board and created system boards employing multiple JPIC units. The ASIC implementation, based on Ramon Chips' 180nm CMOS RadSafe[TM] RH cell library enables superior radiation hardness.

  17. Genome sequence of dwarf birch (Betula nana) and cross-species RAD markers.

    Science.gov (United States)

    Wang, Nian; Thomson, Marian; Bodles, William J A; Crawford, Robert M M; Hunt, Harriet V; Featherstone, Alan Watson; Pellicer, Jaume; Buggs, Richard J A

    2013-06-01

    New sequencing technologies allow development of genome-wide markers for any genus of ecological interest, including plant genera such as Betula (birch) that have previously proved difficult to study due to widespread polyploidy and hybridization. We present a de novo reference genome sequence assembly, from 66× short read coverage, of Betula nana (dwarf birch) - a diploid that is the keystone woody species of subarctic scrub communities but of conservation concern in Britain. We also present 100 bp PstI RAD markers for B. nana and closely related Betula tree species. Assembly of RAD markers in 15 individuals by alignment to the reference B. nana genome yielded 44-86k RAD loci per individual, whereas de novo RAD assembly yielded 64-121k loci per individual. Of the loci assembled by the de novo method, 3k homologous loci were found in all 15 individuals studied, and 35k in 10 or more individuals. Matching of RAD loci to RAD locus catalogues from the B. nana individual used for the reference genome showed similar numbers of matches from both methods of RAD locus assembly but indicated that the de novo RAD assembly method may overassemble some paralogous loci. In 12 individuals hetero-specific to B. nana 37-47k RAD loci matched a catalogue of RAD loci from the B. nana individual used for the reference genome, whereas 44-60k RAD loci aligned to the B. nana reference genome itself. We present a preliminary study of allele sharing among species, demonstrating the utility of the data for introgression studies and for the identification of species-specific alleles.

  18. Saccharomyces cerevisiae RAD27 complements its Escherichia coli homolog in damage repair but not mutation avoidance.

    Science.gov (United States)

    Ohnishi, Gaku; Daigaku, Yasukazu; Nagata, Yuki; Ihara, Makoto; Yamamoto, Kazuo

    2004-06-01

    In eukaryotes, the flap endonuclease of Rad27/Fen-1 is thought to play a critical role in lagging-strand DNA replication by removing ribonucleotides present at the 5' ends of Okazaki fragments, and in base excision repair by cleaving a 5' flap structure that may result during base excision repair. Saccharomyces cerevisiae rad27Delta mutants further display a repeat tract instability phenotype and a high rate of forward mutations to canavanine resistance that result from duplications of DNA sequence, indicating a role in mutation avoidance. Two conserved motifs in Rad27/Fen-1 show homology to the 5' --> 3' exonuclease domain of Escherichia coli DNA polymerase I. The strain defective in the 5' --> 3' exonuclease domain in DNA polymerase I shows essentially the same phenotype as the yeast rad27Delta strain. In this study, we expressed the yeast RAD27 gene in an E. coli strain lacking the 5' --> 3' exonuclease domain in DNA polymerase I in order to test whether eukaryotic RAD27/FEN-1 can complement the defect of its bacterial homolog. We found that the yeast Rad27 protein complements sensitivity to methyl methanesulfonate in an E. coli mutant. On the other hand, Rad27 protein did not reduce the high rate of spontaneous mutagenesis in the E. coli tonB gene which results from duplication of DNA. These results indicate that the yeast Rad27 and E. coli 5' --> 3' exonuclease act on the same substrate. We argue that the lack of mutation avoidance of yeast RAD27 in E. coli results from a lack of interaction between the yeast Rad27 protein and the E. coli replication clamp (beta-clamp).

  19. A Rad53 Independent Function of Rad9 Becomes Crucial for Genome Maintenance in the Absence of the RecQ Helicase Sgs1

    DEFF Research Database (Denmark)

    Nielsen, Ida; Bentsen, Iben Bach; Andersen, Anni Hangaard;

    2013-01-01

    The conserved family of RecQ DNA helicases consists of caretaker tumour suppressors, that defend genome integrity by acting on several pathways of DNA repair that maintain genome stability. In budding yeast, Sgs1 is the sole RecQ helicase and it has been implicated in checkpoint responses......, replisome stability and dissolution of double Holliday junctions during homologous recombination. In this study we investigate a possible genetic interaction between SGS1 and RAD9 in the cellular response to methyl methane sulphonate (MMS) induced damage and compare this with the genetic interaction between...... SGS1 and RAD24. The Rad9 protein, an adaptor for effector kinase activation, plays well-characterized roles in the DNA damage checkpoint response, whereas Rad24 is characterized as a sensor protein also in the DNA damage checkpoint response. Here we unveil novel insights into the cellular response...

  20. ATR, Claspin and the Rad9-Rad1-Hus1 complex regulate Chk1 and Cdc25A in the absence of DNA damage

    DEFF Research Database (Denmark)

    Sørensen, Claus Storgaard; Syljuåsen, Randi G; Lukas, Jiri

    2004-01-01

    The ATR and Chk1 kinases are essential to maintain genomic integrity. ATR, with Claspin and the Rad9-Rad1-Hus1 complex, activates Chk1 after DNA damage. Chk1-mediated phosphorylation of the Cdc25A phosphatase is required for the mammalian S-phase checkpoint. Here, we show that during physiological...... S phase the regulation of the Chk1-Cdc25A pathway depends on ATR, Claspin, Rad9, and Hus1. Human cells with chemically or genetically ablated ATR showed inhibition of Chk1-dependent phosphorylation of Cdc25A, and they accumulated Cdc25A without external DNA damage. Furthermore, si......RNA-mediated depletion of Claspin, Rad9 and Hus1 also stabilized Cdc25A. ATR ablation also inhibited the activatory phosphorylation of Chk1 on serine 345. Thus, the ATR-Chk1-Cdc25A pathway represents an integral part of physiological S-phase progression, and interference with this mechanism undermines viability...

  1. Polymorphisms of Homologous Recombination RAD51, RAD51B, XRCC2, and XRCC3 Genes and the Risk of Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Maria Nowacka-Zawisza

    2015-01-01

    Full Text Available Genetic polymorphisms in DNA repair genes may induce individual variations in DNA repair capacity, which may in turn contribute to the risk of cancer developing. Homologous recombination repair (HRR plays a critical role in maintaining chromosomal integrity and protecting against carcinogenic factors. The aim of the present study was to evaluate the relationship between prostate cancer risk and the presence of single nucleotide polymorphisms (SNPs in the genes involved in HRR, that is, RAD51 (rs1801320 and rs1801321, RAD51B (rs10483813 and rs3784099, XRCC2 (rs3218536, and XRCC3 (rs861539. Polymorphisms were analyzed by PCR-RFLP and Real-Time PCR in 101 patients with prostate adenocarcinoma and 216 age- and sex-matched controls. A significant relationship was detected between the RAD51 gene rs1801320 polymorphism and increased prostate cancer risk. Our results indicate that the RAD51 gene rs1801320 polymorphism may contribute to prostate cancer susceptibility in Poland.

  2. Polymorphisms of Homologous Recombination RAD51, RAD51B, XRCC2, and XRCC3 Genes and the Risk of Prostate Cancer

    Science.gov (United States)

    Nowacka-Zawisza, Maria; Wiśnik, Ewelina; Wasilewski, Andrzej; Skowrońska, Milena; Forma, Ewa; Bryś, Magdalena; Różański, Waldemar; Krajewska, Wanda M.

    2015-01-01

    Genetic polymorphisms in DNA repair genes may induce individual variations in DNA repair capacity, which may in turn contribute to the risk of cancer developing. Homologous recombination repair (HRR) plays a critical role in maintaining chromosomal integrity and protecting against carcinogenic factors. The aim of the present study was to evaluate the relationship between prostate cancer risk and the presence of single nucleotide polymorphisms (SNPs) in the genes involved in HRR, that is, RAD51 (rs1801320 and rs1801321), RAD51B (rs10483813 and rs3784099), XRCC2 (rs3218536), and XRCC3 (rs861539). Polymorphisms were analyzed by PCR-RFLP and Real-Time PCR in 101 patients with prostate adenocarcinoma and 216 age- and sex-matched controls. A significant relationship was detected between the RAD51 gene rs1801320 polymorphism and increased prostate cancer risk. Our results indicate that the RAD51 gene rs1801320 polymorphism may contribute to prostate cancer susceptibility in Poland. PMID:26339569

  3. Transcription coupled nucleotide excision repair in the yeast Saccharomyces cerevisiae: The ambiguous role of Rad26.

    Science.gov (United States)

    Li, Shisheng

    2015-12-01

    Transcription coupled nucleotide excision repair (TC-NER) is believed to be triggered by an RNA polymerase stalled at a lesion in the transcribed strand of actively transcribed genes. Rad26, a DNA-dependent ATPase in the family of SWI2/SNF2 chromatin remodeling proteins, plays an important role in TC-NER in Saccharomyces cerevisiae. However, Rad26 is not solely responsible for TC-NER and Rpb9, a nonessential subunit of RNA polymerase II (RNAP II), is largely responsible for Rad26-independent TC-NER. The Rad26-dependent and Rpb9-dependent TC-NER have different efficiencies in genes with different transcription levels and in different regions of a gene. Rad26 becomes entirely or partially dispensable for TC-NER in the absence of Rpb4, another nonessential subunit of RNAP II, or a number of transcription elongation factors (Spt4, Spt5 and the RNAP II associated factor complex). Rad26 may not be a true transcription-repair coupling factor that recruits the repair machinery to the damaged sites where RNAP II stalls. Rather, Rad26 may facilitate TC-NER indirectly, by antagonizing the action of TC-NER repressors that normally promote transcription elongation. The underlying mechanism of how Rad26 functions in TC-NER remains to be elucidated.

  4. Enhancement of the RAD51 Recombinase Activity by the Tumor Suppressor PALB2

    Energy Technology Data Exchange (ETDEWEB)

    Dray, Eloise; Etchin, Julia; Wiese, Claudia; Saro, Dorina; Williams, Gareth J.; Hammel, Michal; Yu, Xiong; Galkin, Vitold E.; Liu, Dongqing; Tsai, Miaw-Sheue; Sy, Shirley M-H.; Egelman, Edward; Chen, Junjie; Sung, Patrick; Schild, D.

    2010-08-24

    Homologous recombination mediated by the RAD51 recombinase helps eliminate chromosomal lesions, such as DNA double-stranded breaks induced by radiation or arising from injured DNA replication forks. The tumor suppressors BRCA2 and PALB2 act together to deliver RAD51 to chromosomal lesions to initiate repair. Here we document a new function of PALB2 in the enhancement of RAD51's ability to form the D-loop. We show that PALB2 binds DNA and physically interacts with RAD51. Importantly, while PALB2 alone stimulates D-loop formation, a cooperative effect is seen with RAD51AP1, an enhancer of RAD51. This stimulation stems from PALB2's ability to function with RAD51 and RAD51AP1 to assemble the synaptic complex. Our results help unveil a multi-faceted role of PALB2 in chromosome damage repair. Since PALB2 mutations can cause breast and other tumors or lead to Fanconi anemia, our findings are important for understanding the mechanism of tumor suppression in humans.

  5. Structural and functional conservation of two human homologs of the yeast DNA repair gene RAD6.

    NARCIS (Netherlands)

    M.H.M. Koken (Marcel); P. Reynolds (Paul); I. Jaspers-Dekker (Iris); L. Prakash; S. Prakash; D. Bootsma (Dirk); J.H.J. Hoeijmakers (Jan)

    1991-01-01

    textabstractThe RAD6 gene of Saccharomyces cerevisiae encodes a ubiquitin-conjugating enzyme (E2) that is required for DNA repair, damage-induced mutagenesis, and sporulation. We have cloned the two human RAD6 homologs, designated HHR6A and HHR6B. The two 152-amino acid human proteins share 95% sequ

  6. OsRAD51C Is Essential for Double Strand Break Repair in Rice Meiosis

    Directory of Open Access Journals (Sweden)

    Ding eTang

    2014-05-01

    Full Text Available RAD51C is one of the RAD51 paralogs that plays an important role in DNA double-strand break repair by homologous recombination. Here, we identified and characterized OsRAD51C, the rice homolog of human RAD51C. The Osrad51c mutant plant is normal in vegetative growth but exhibits complete male and female sterility. Cytological investigation revealed that homologous pairing and synapsis were severely disrupted. Massive chromosome fragmentation occurred during metaphase I in Osrad51c meiocytes, and was fully suppressed by the CRC1 mutation. Immunofluorescence analysis showed that OsRAD51C localized onto the chromosomes from leptotene to early pachytene during prophase I, and that normal loading of OsRAD51C was dependent on OsREC8, PAIR2, and PAIR3. Additionally, ZEP1 did not localize properly in Osrad51c, indicating that OsRAD51C is required for synaptonemal complex assembly. Our study also provided evidence in support of a functional divergence in RAD51C among organisms.

  7. FBH1 helicase disrupts RAD51 filaments in vitro and modulates homologous recombination in mammalian cells

    DEFF Research Database (Denmark)

    Simandlova, Jitka; Zagelbaum, Jennifer; Payne, Miranda J;

    2013-01-01

    filaments on DNA through its ssDNA translocase function. Consistent with this, a mutant mouse embryonic stem cell line with a deletion in the FBH1 helicase domain fails to limit RAD51 chromatin association and shows hyper-recombination. Our data are consistent with FBH1 restraining RAD51 DNA binding under...

  8. Rad52 forms DMA repair and recombination centers during S phase

    DEFF Research Database (Denmark)

    Lisby, M.; Rothstein, R.; Mortensen, Uffe Hasbro

    2001-01-01

    fluorescent protein (GFP) is fully functional in DNA repair and recombination. After induction of DNA double-strand breaks by gamma -irradiation, meiosis, or the HO endonuclease, Rad52-GFP relocalizes from a diffuse nuclear distribution to distinct foci. Interestingly, Rad52 foci are formed almost exclusively...

  9. RAD51B in Familial Breast Cancer

    DEFF Research Database (Denmark)

    Pelttari, Liisa M; Khan, Sofia; Vuorela, Mikko

    2016-01-01

    Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predispositio...

  10. Requirement of Rad5 for DNA Polymerase ζ-Dependent Translesion Synthesis in Saccharomyces cerevisiae

    Science.gov (United States)

    Pagès, Vincent; Bresson, Anne; Acharya, Narottam; Prakash, Satya; Fuchs, Robert P.; Prakash, Louise

    2008-01-01

    In yeast, Rad6–Rad18-dependent lesion bypass involves translesion synthesis (TLS) by DNA polymerases η or ζ or Rad5-dependent postreplication repair (PRR) in which error-free replication through the DNA lesion occurs by template switching. Rad5 functions in PRR via its two distinct activities—a ubiquitin ligase that promotes Mms2–Ubc13-mediated K63-linked polyubiquitination of PCNA at its lysine 164 residue and a DNA helicase that is specialized for replication fork regression. Both these activities are important for Rad5's ability to function in PRR. Here we provide evidence for the requirement of Rad5 in TLS mediated by Polζ. Using duplex plasmids carrying different site-specific DNA lesions—an abasic site, a cis–syn TT dimer, a (6-4) TT photoproduct, or a G-AAF adduct—we show that Rad5 is needed for Polζ-dependent TLS. Rad5 action in this role is likely to be structural, since neither the inactivation of its ubiquitin ligase activity nor the inactivation of its helicase activity impairs its role in TLS. PMID:18757916

  11. The cohesin subunit RAD21L functions in meiotic synapsis and exhibits sexual dimorphism in fertility

    NARCIS (Netherlands)

    A. Herrán; C. Gutierréz-Caballero; M. Sáanchez-Martin; T. Hernández; A. Viera; J.L. Barbero; E. de Álava; D.G. de Rooij; J. Ángel Suja; E. Llano; A.M. Pendas

    2011-01-01

    The cohesin complex is a ring-shaped proteinaceous structure that entraps the two sister chromatids after replication until the onset of anaphase when the ring is opened by proteolytic cleavage of its alpha-kleisin subunit (RAD21 at mitosis and REC8 at meiosis) by separase. RAD21L is a recently iden

  12. Meiotic recombination in Arabidopsis is catalysed by DMC1, with RAD51 playing a supporting role.

    Directory of Open Access Journals (Sweden)

    Olivier Da Ines

    Full Text Available Recombination establishes the chiasmata that physically link pairs of homologous chromosomes in meiosis, ensuring their balanced segregation at the first meiotic division and generating genetic variation. The visible manifestation of genetic crossing-overs, chiasmata are the result of an intricate and tightly regulated process involving induction of DNA double-strand breaks and their repair through invasion of a homologous template DNA duplex, catalysed by RAD51 and DMC1 in most eukaryotes. We describe here a RAD51-GFP fusion protein that retains the ability to assemble at DNA breaks but has lost its DNA break repair capacity. This protein fully complements the meiotic chromosomal fragmentation and sterility of Arabidopsis rad51, but not rad51 dmc1 mutants. Even though DMC1 is the only active meiotic strand transfer protein in the absence of RAD51 catalytic activity, no effect on genetic map distance was observed in complemented rad51 plants. The presence of inactive RAD51 nucleofilaments is thus able to fully support meiotic DSB repair and normal levels of crossing-over by DMC1. Our data demonstrate that RAD51 plays a supporting role for DMC1 in meiotic recombination in the flowering plant, Arabidopsis.

  13. A novel Rad gene polymorphism combined with obesity increases risk for type 2 diabetes mellitus

    Institute of Scientific and Technical Information of China (English)

    王国英; 牛天华; 陈常忠; 李琼芳; 徐希平

    2004-01-01

    @@ The ras-associated diabetes (Rad) was initially identified by subtraction cloning from the skeletal muscle of humans with non-insulin dependent diabetes mellitus (type 2 DM).1 Rad mRNA expression is markedly increased in the skeletal muscle of type 2 DM patients compared with normal controls.

  14. Comparison of clastogen-induced gene expression profiles in wild-type and DNA repair-deficient Rad54/Rad54B cells

    Directory of Open Access Journals (Sweden)

    van Benthem Jan

    2010-01-01

    Full Text Available Abstract Background Previously we found that Rad54/Rad54B cells are more sensitive towards mitomycin C (MMC as compared to wild-type (WT cells. This difference in sensitivity was absent upon exposure to other clastogens like bleomycin (BLM and γ-radiation. In order to get further insight into possible underlying mechanisms, gene expression changes in WT and Rad54/Rad54B MEFs (mouse embryonic fibroblasts after exposure to the clastogens MMC and BLM were investigated. Exposures of these cells to mutagens (N-ac-AAF and ENU and vehicle were taken as controls. Results Most exposures resulted in an induction of DNA damage signaling and apoptosis genes and a reduced expression of cell division genes in cells of both genotypes. As expected, responses to N-ac-AAF were very similar in both genotypes. ENU exposure did not lead to significant gene expression changes in cells of both genotypes, presumably due to its short half-life. Gene expression responses to clastogens, however, showed a genotype-dependent effect for BLM and MMC. MMC treated Rad54/Rad54B MEFs showed no induction of p53-signaling, DNA damage response and apoptosis as seen for all the other treatments. Conclusion These data support our finding that different types of clastogens exist and that responses to these types depend on the DNA repair status of the cells.

  15. Specific interaction between DNA polymerase II (PolD) and RadB, a Rad51/Dmc1 homolog, in Pyrococcus furiosus.

    Science.gov (United States)

    Hayashi, I; Morikawa, K; Ishino, Y

    1999-12-15

    Pyrococcus furiosus has an operon containing the DNA polymerase II (PolD) gene and three other genes. Using a two-hybrid screening to examine the interactions of the proteins encoded by the operon, we identified a specific interaction between the second subunit of PolD (DP1) and a Rad51/Dmc1 homologous protein (RadB). To ensure the specific interaction between these two proteins, each gene in the operon was expressed in Escherichia coli or insect cells separately and the products were purified. The in vitro analyses using the purified proteins also showed the interaction between DP1 and RadB. The deletion mutant analysis of DP1 revealed that a region important for binding with RadB is located in the central part of the sequence (amino acid residues 206-498). This region has an overlap to the C-terminal half (amino acids 334-613), which is highly conserved among euryarchaeal DP1s and is essential for the activity of PolD. Our results suggest that, although RadB does not noticeably affect the primer extension ability of PolD in vitro, PolD may utilize the RadB protein in DNA synthesis under certain conditions.

  16. Breast Imaging Reporting and Data System (BI-RADS) breast composition descriptors: Automated measurement development for full field digital mammography

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, E. E.; Sellers, T. A.; Lu, B. [Department of Cancer Epidemiology, Division of Population Sciences, H. Lee Moffitt Cancer Center, Tampa, Florida 33612 (United States); Heine, J. J. [Department of Cancer Imaging and Metabolism, H. Lee Moffitt Cancer Center, Tampa, Florida 33612 (United States)

    2013-11-15

    measures were significantly associated with breast cancer status in the adjusted models: (a) OR = 1.95 (1.24, 3.09) for BR{sub pg}; (b) OR = 1.42 (0.87, 2.32) for BR{sub vc}; and (c) OR = 2.13 (1.22, 3.72) for BR{sub vr}. The radiologist-reported measures from the patient records showed a similar association, OR = 1.49 (0.99, 2.24), although only borderline statistically significant.Conclusions: A general framework was developed and validated for converting calibrated mammograms and continuous measures of breast density to fully automated approximations for the BI-RADS breast composition descriptors. The techniques are general and suitable for a broad range of clinical and research applications.

  17. Influence of SDZ RAD vs. MMF on gastric emptying in renal transplant recipients.

    Science.gov (United States)

    Maes, Bart D; Evenepoel, Pieter; Kuypers, Dirk; Geypens, Benny; Ghoos, Yvo; Vanrenterghem, Yves

    2003-06-01

    SDZ RAD and mycophenolate mofetil (MMF) are increasingly used in the prevention of renal allograft rejection. SDZ RAD, having a macrolide structure, and MMF, known with gastrointestinal side-effects, may have gastric motility modifying properties. Gastric emptying was examined 1 yr after renal transplantation in eight patients taking corticosteroids (CS), cyclosporin A (CsA) and SDZ RAD and six patients treated with CS, CsA and MMF. Comparing the two groups, no significant differences in gastric emptying of solids and liquids were noted. Compared with normal volunteers, solid gastric emptying was faster in the SDZ RAD group and similar in the MMF group. It is concluded that in stable renal transplant recipients treated with MMF, gastric emptying was normal. Because of the impact on drug absorption and gastrointestinal symptoms, further studies are indicated to corroborate the potential prokinetic properties of SDZ RAD.

  18. Comparison of Danish dichotomous and BI-RADS classifications of mammographic density

    DEFF Research Database (Denmark)

    Hodge, Rebecca; Hellmann, Sophie Sell; von Euler-Chelpin, My

    2014-01-01

    dichotomous mammographic density classification system from 1991 to 2001 with the density BI-RADS classifications, in an attempt to validate the Danish classification system. MATERIAL AND METHODS: The study sample consisted of 120 mammograms taken in Copenhagen in 1991-2001, which tested false positive......, and which were in 2012 re-assessed and classified according to the BI-RADS classification system. We calculated inter-rater agreement between the Danish dichotomous mammographic classification as fatty or mixed/dense and the four-level BI-RADS classification by the linear weighted Kappa statistic. RESULTS......: Of the 120 women, 32 (26.7%) were classified as having fatty and 88 (73.3%) as mixed/dense mammographic density, according to Danish dichotomous classification. According to BI-RADS density classification, 12 (10.0%) women were classified as having predominantly fatty (BI-RADS code 1), 46 (38.3%) as having...

  19. Rad54 and Mus81 cooperation promotes DNA damage repair and restrains chromosome missegregation

    DEFF Research Database (Denmark)

    Ghamrasni, S El; Cardoso, R; Li, L;

    2016-01-01

    Rad54 and Mus81 mammalian proteins physically interact and are important for the homologous recombination DNA repair pathway; however, their functional interactions in vivo are poorly defined. Here, we show that combinatorial loss of Rad54 and Mus81 results in hypersensitivity to DNA......-damaging agents, defects on both the homologous recombination and non-homologous DNA end joining repair pathways and reduced fertility. We also observed that while Mus81 deficiency diminished the cleavage of common fragile sites, very strikingly, Rad54 loss impaired this cleavage to even a greater extent....... The inefficient repair of DNA double-strand breaks (DSBs) in Rad54(-/-)Mus81(-/-) cells was accompanied by elevated levels of chromosome missegregation and cell death. Perhaps as a consequence, tumor incidence in Rad54(-/-)Mus81(-/-) mice remained comparable to that in Mus81(-/-) mice. Our study highlights...

  20. The role of RAD51 in etoposide (VP16) resistance in small cell lung cancer

    DEFF Research Database (Denmark)

    Hansen, Lasse Tengbjerg; Lundin, Cecilia; Spang-Thomsen, Mogens;

    2003-01-01

    Etoposide (VP16) is a potent inducer of DNA double-strand breaks (DSBs) and is efficiently used in small cell lung cancer (SCLC) therapy. However, acquired VP16 resistance remains an important barrier to effective treatment. To understand the underlying mechanisms for VP16 resistance in SCLC, we...... investigated DSB repair and cellular VP16 sensitivity of SCLC cells. VP16 sensitivity and RAD51, DNA-PK(cs), topoisomerase IIalpha and P-glycoprotein protein levels were determined in 17 SCLC cell lines. In order to unravel the role of RAD51 in VP16 resistance, we cloned the human RAD51 gene, transfected SCLC...... cells with RAD51 sense or antisense constructs and measured the VP16 resistance. Finally, we measured VP16-induced DSBs in the 17 SCLC cell lines. Two cell lines exhibited a multidrug-resistant phenotype. In the other SCLC cell lines, the cellular VP16 resistance was positively correlated with the RAD51...

  1. Novel Inhibitors of Rad6 Ubiquitin Conjugating Enzyme: Design, Synthesis, Identification, and Functional Characterization

    Science.gov (United States)

    Nangia-Makker, Pratima; Balan, Vitaly; Morelli, Matteo; Kothayer, Hend; Westwell, Andrew D.; Shekhar, Malathy P.V.

    2013-01-01

    Protein ubiquitination is important for cell signaling, DNA repair, and proteasomal degradation, and it is not surprising that alterations in ubiquitination occur frequently in cancer. Ubiquitin-conjugating enzymes (E2) mediate ubiquitination by selective interactions with ubiquitin-activating (E1) and ubiquitin ligase (E3) enzymes, and thus selective E2 small molecule inhibitor (SMI) will provide specificity unattainable with proteasome inhibitors. Here we describe synthesis and functional characterization of the first SMIs of human E2 Rad6B, a fundamental component of translesion synthesis DNA repair. A pharmacophore model for consensus E2 ubiquitin-binding sites was generated for virtual screening to identify E2 inhibitor candidates. Twelve triazine (TZ) analogs screened in silico by molecular docking to the Rad6B X-ray structure were verified by their effect on Rad6B ubiquitination of histone H2A. TZs #8 and 9 docked to the Rad6B catalytic site with highest complementarity. TZs #1, 2, 8, and 9 inhibited Rad6B-ubiquitin thioester formation and subsequent ubiquitin transfer to histone H2A. SMI #9 inhibition of Rad6 was selective as BCA2 ubiquitination by E2 UbcH5 was unaffected by SMI #9. SMI #9 more potently inhibited proliferation, colony formation, and migration than SMI #8, and induced MDA-MB-231 breast cancer cell G2–M arrest and apoptosis. Ubiquitination assays using Rad6 immunoprecipitated from SMI #8- or 9-treated cells confirmed inhibition of endogenous Rad6 activity. Consistent with our previous data showing Rad6B-mediated polyubiquitination stabilizes β-catenin, MDAMB-231 treatment with SMIs #8 or 9 decreased β-catenin protein levels. Together these results describe identification of the first Rad6 SMIs. PMID:23339190

  2. Characterization of the interaction between Rfa1 and Rad24 in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Gunjan Piya

    Full Text Available Maintaining the integrity of the genome requires the high fidelity duplication of the genome and the ability of the cell to recognize and repair DNA lesions. The heterotrimeric single stranded DNA (ssDNA binding complex Replication Protein A (RPA is central to multiple DNA processes, which are coordinated by RPA through its ssDNA binding function and through multiple protein-protein interactions. Many RPA interacting proteins have been reported through large genetic and physical screens; however, the number of interactions that have been further characterized is limited. To gain a better understanding of how RPA functions in DNA replication, repair, and cell cycle regulation and to identify other potential functions of RPA, a yeast two hybrid screen was performed using the yeast 70 kDa subunit, Replication Factor A1 (Rfa1, as a bait protein. Analysis of 136 interaction candidates resulted in the identification of 37 potential interacting partners, including the cell cycle regulatory protein and DNA damage clamp loader Rad24. The Rfa1-Rad24 interaction is not dependent on ssDNA binding. However, this interaction appears affected by DNA damage. The regions of both Rfa1 and Rad24 important for this interaction were identified, and the region of Rad24 identified is distinct from the region reported to be important for its interaction with Rfc2 5. This suggests that Rad24-Rfc2-5 (Rad24-RFC recruitment to DNA damage substrates by RPA occurs, at least partially, through an interaction between the N terminus of Rfa1 and the C terminus of Rad24. The predicted structure and location of the Rad24 C-terminus is consistent with a model in which RPA interacts with a damage substrate, loads Rad24-RFC at the 5' junction, and then releases the Rad24-RFC complex to allow for proper loading and function of the DNA damage clamp.

  3. Giardia duodenalis Rad52 protein: biochemical characterization and response upon DNA damage.

    Science.gov (United States)

    Martínez-Miguel, Rosa María; Sandoval-Cabrera, Antonio; Bazán-Tejeda, María Luisa; Torres-Huerta, Ana Laura; Martínez-Reyes, Diego A; Bermúdez-Cruz, Rosa María

    2017-08-01

    Giardia duodenalis is a flagellated binucleated protozoan that colonizes the small intestine in mammals, causing giardiasis, acute or chronic diarrhea. DNA double strand break either endogenously or exogenously generated is a major insult to DNA and its repair by homologous recombination (HR) is crucial for genomic stability. During HR, Rad52 plays key roles in the loading of the Rad51 recombinase, and the annealing of the second double-strand break end to the displaced strand of the D-loop structure. Among the functions found in vitro in yeast and human Rad52 protein are: ssDNA or dsDNA binding activity, ability to anneal bare or RPA coated-ssDNA, as well as multimeric ring formation. In this work, we searched for conserved domains in a putative Rad52 protein from G. duodenalis (GdRad52). Its coding sequence was cloned, expressed and purified to study its biochemical properties. rGdRad52 binds to dsDNA and ssDNA, with greater affinity for the latter. Likewise, rGdRad52 promotes annealing of DNA uncoated and coated with GdRPA1. rGdRad52 interacts with GdDMC1B and with GdRPA1 protein as shown in far western blotting assay. Additionally, rGdRad52 formed multimeric rings as observed by electronic microscopy. Finally, GdRad52 is over expressed in response upon DNA damage inflicted on trophozoites. © The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  4. Temperature calibration of Pico-Rad detectors for radon measurement.

    Science.gov (United States)

    Bem, H; Bem, E M; Chruścielewski, W; Skalski, H

    2000-01-01

    A simple mathematical equation linking the activity of adsorbed radon in the vials to the time and temperature of its exposure is discussed. The calibration coefficient--Ks, defined as activity measured in cpm after saturation time, corresponding to radon air concentration of 1 Bq m-3, was determined for four temperatures: 284, 291, 294 and 298 K. A linear relationship of ln Ks values versus T-1 was found. The relatively high difference in Ks values: 2.12 and 1.24 cpm/Bq m-3 for the temperatures of 284 and 298 K, respectively, was observed. It indicates that temperature fluctuations during Pico-Rad vial exposure may lead to erroneous results if the constant average temperature of exposure is introduced into a commonly used computer programme for calculating Rn concentration.

  5. Temperature calibration of PICO-RAD detectors for radon measurement

    Energy Technology Data Exchange (ETDEWEB)

    Bem, H.; Bem, E.M.; Chruscielewski, W.; Skalski, H. [Politechnika Lodzka, Lodz (Poland)

    1996-10-01

    A simple mathematical equation linking the activity of adsorbed radon in the vials to the time of its exposure has been discussed. The calibration coefficient K{sub s}, defined as a measured activity in cpm after a saturation time, corresponding to a radon air concentration of 1 Bq m{sup -3} has been determined for four temperatures: 284, 291, 294 and 298 K. A linear relationship of ln K{sub s} values versus T{sup -1} has been found. The relatively high difference in K{sub s} values: 2.12 and 1.24 cpm/Bq m{sup 3} for the temperatures of 284 and 298 K, respectively, was observed. It indicates that temperature fluctuations during Pico-Rad vial exposure may lead to erroneous results if the constant average temperature of exposure is introduced into a commonly used computer program for calculating Rn concentration. (author). 6 refs, 4 figs.

  6. Rad51与乳腺癌的发生

    Institute of Scientific and Technical Information of China (English)

    石静; 王雅杰; 王宁

    2010-01-01

    @@ Rad51基因位于染色体15q15.1上,由10个外显子和9个内含子组成,DNA分子大小约30kb,其编码蛋白含有339个氨基酸,是 DNA同源重组修复(homologous recombination repair,HRR)的主要关键酶之一,它协同其同系物在损伤的DNA末端形成"核蛋白丝",催化断裂的DNA双链与同源DNA姐妹链进行链间转移置换[1,2].

  7. Rad51C deficiency destabilizes XRCC3, impairs recombination and radiosensitizes S/G2-phase cells

    Energy Technology Data Exchange (ETDEWEB)

    Lio, Yi-Ching; Schild, David; Brenneman, Mark A.; Redpath, J. Leslie; Chen, David J.

    2004-05-01

    The highly conserved Rad51 protein plays an essential role in repairing DNA damage through homologous recombination. In vertebrates, five Rad51 paralogs (Rad51B, Rad51C, Rad51D, XRCC2, XRCC3) are expressed in mitotically growing cells, and are thought to play mediating roles in homologous recombination, though their precise functions remain unclear. Here we report the use of RNA interference to deplete expression of Rad51C protein in human HT1080 and HeLa cells. In HT1080 cells, depletion of Rad51C by small interfering RNA caused a significant reduction of frequency in homologous recombination. The level of XRCC3 protein was also sharply reduced in Rad51C-depleted HeLa cells, suggesting that XRCC3 is dependent for its stability upon heterodimerization with Rad51C. In addition, Rad51C-depleted HeLa cells showed hypersensitivity to the DNA cross-linking agent mitomycin C, and moderately increased sensitivity to ionizing radiation. Importantly, the radiosensitivity of Rad51C-deficient HeLa cells was evident in S and G{sub 2}/M phases of the cell cycle but not in G{sub 1} phase. Together, these results provide direct cellular evidence for the importance of human Rad51C in homologous recombinational repair.

  8. The Smc5-Smc6 complex and SUMO modification of Rad52 regulates recombinational repair at the ribosomal gene locus

    DEFF Research Database (Denmark)

    Torres-Rosell, Jordi; Sunjevaric, Ivana; De Piccoli, Giacomo;

    2007-01-01

    at an extranucleolar site. The nucleolar exclusion of Rad52 recombination foci entails Mre11 and Smc5-Smc6 complexes and depends on Rad52 SUMO (small ubiquitin-related modifier) modification. Remarkably, mutations that abrogate these activities result in the formation of Rad52 foci within the nucleolus and cause r...

  9. Erythropoietic defect associated with reduced cell proliferation in mice lacking the 26S proteasome shuttling factor Rad23b

    NARCIS (Netherlands)

    S. Bergink (Steven); A.F. Theil (Arjan); W. Toussaint (Wendy); I.M. de Cuyper (Iris); D.I. Kulu (Divine); T. Clapes (Thomas); R. van der Linden (Reinier); J.A.A. Demmers (Jeroen); E.P. Mul (Eric); F.P. van Alphen (Floris); J.A. Marteijn (Jurgen); T. van Gent (Teus); A. Maas (Alex); C. Robin (Catherine); J.N.J. Philipsen (Sjaak); W. Vermeulen (Wim); J.R. Mitchell (James); L. Gutiérrez (Laura)

    2013-01-01

    textabstractRad23a and Rad23b proteins are linked to nucleotide excision DNA repair (NER) via association with the DNA damage recognition protein xeroderma pigmentosum group C (XPC) are and known to be implicated in protein turnover by the 26S proteasome. Rad23b-null mice are NER proficient, likely

  10. Erythropoietic Defect Associated with Reduced Cell Proliferation in Mice Lacking the 26S Proteasome Shuttling Factor Rad23b

    NARCIS (Netherlands)

    Bergink, Steven; Theil, Arjan F.; Toussaint, Wendy; De Cuyper, Iris M.; Kulu, Divine I.; Clapes, Thomas; van der Linden, Reinier; Demmers, Jeroen A.; Mul, Eric P.; van Alphen, Floris P.; Marteijn, Jurgen A.; van Gent, Teus; Maas, Alex; Robin, Catherine; Philipsen, Sjaak; Vermeulen, Wim; Mitchell, James R.; Gutierrez, Laura

    2013-01-01

    Rad23a and Rad23b proteins are linked to nucleotide excision DNA repair (NER) via association with the DNA damage recognition protein xeroderma pigmentosum group C (XPC) are and known to be implicated in protein turnover by the 26S proteasome. Rad23b-null mice are NER proficient, likely due to the r

  11. Lysine residue 185 of Rad1 is a topological but not a functional counterpart of lysine residue 164 of PCNA.

    Directory of Open Access Journals (Sweden)

    Niek Wit

    Full Text Available Monoubiquitylation of the homotrimeric DNA sliding clamp PCNA at lysine residue 164 (PCNA(K164 is a highly conserved, DNA damage-inducible process that is mediated by the E2/E3 complex Rad6/Rad18. This ubiquitylation event recruits translesion synthesis (TLS polymerases capable of replicating across damaged DNA templates. Besides PCNA, the Rad6/Rad18 complex was recently shown in yeast to ubiquitylate also 9-1-1, a heterotrimeric DNA sliding clamp composed of Rad9, Rad1, and Hus1 in a DNA damage-inducible manner. Based on the highly similar crystal structures of PCNA and 9-1-1, K185 of Rad1 (Rad1(K185 was identified as the only topological equivalent of PCNA(K164. To investigate a potential role of posttranslational modifications of Rad1(K185 in DNA damage management, we here generated a mouse model with a conditional deletable Rad1(K185R allele. The Rad1(K185 residue was found to be dispensable for Chk1 activation, DNA damage survival, and class switch recombination of immunoglobulin genes as well as recruitment of TLS polymerases during somatic hypermutation of immunoglobulin genes. Our data indicate that Rad1(K185 is not a functional counterpart of PCNA(K164.

  12. RAD51C germline mutations in breast and ovarian cancer cases from high-risk families.

    Directory of Open Access Journals (Sweden)

    Jessica Clague

    Full Text Available BRCA1 and BRCA2 are the most well-known breast cancer susceptibility genes. Additional genes involved in DNA repair have been identified as predisposing to breast cancer. One such gene, RAD51C, is essential for homologous recombination repair. Several likely pathogenic RAD51C mutations have been identified in BRCA1- and BRCA2-negative breast and ovarian cancer families. We performed complete sequencing of RAD51C in germline DNA of 286 female breast and/or ovarian cancer cases with a family history of breast and ovarian cancers, who had previously tested negative for mutations in BRCA1 and BRCA2. We screened 133 breast cancer cases, 119 ovarian cancer cases, and 34 with both breast and ovarian cancers. Fifteen DNA sequence variants were identified; including four intronic, one 5' UTR, one promoter, three synonymous, and six non-synonymous variants. None were truncating. The in-silico SIFT and Polyphen programs were used to predict possible pathogenicity of the six non-synonomous variants based on sequence conservation. G153D and T287A were predicted to be likely pathogenic. Two additional variants, A126T and R214C alter amino acids in important domains of the protein such that they could be pathogenic. Two-hybrid screening and immunoblot analyses were performed to assess the functionality of these four non-synonomous variants in yeast. The RAD51C-G153D protein displayed no detectable interaction with either XRCC3 or RAD51B, and RAD51C-R214C displayed significantly decreased interaction with both XRCC3 and RAD51B (p<0.001. Immunoblots of RAD51C-Gal4 activation domain fusion peptides showed protein levels of RAD51C-G153D and RAD51C-R214C that were 50% and 60% of the wild-type, respectively. Based on these data, the RAD51C-G153D variant is likely to be pathogenic, while the RAD51C- R214C variant is hypomorphic of uncertain pathogenicity. These results provide further support that RAD51C is a rare breast and ovarian cancer susceptibility gene.

  13. CAD-RADS(TM) Coronary Artery Disease - Reporting and Data System. An expert consensus document of the Society of Cardiovascular Computed Tomography (SCCT), the American College of Radiology (ACR) and the North American Society for Cardiovascular Imaging (NASCI). Endorsed by the American College of Cardiology.

    Science.gov (United States)

    Cury, Ricardo C; Abbara, Suhny; Achenbach, Stephan; Agatston, Arthur; Berman, Daniel S; Budoff, Matthew J; Dill, Karin E; Jacobs, Jill E; Maroules, Christopher D; Rubin, Geoffrey D; Rybicki, Frank J; Schoepf, U Joseph; Shaw, Leslee J; Stillman, Arthur E; White, Charles S; Woodard, Pamela K; Leipsic, Jonathon A

    2016-01-01

    The intent of CAD-RADS - Coronary Artery Disease Reporting and Data System is to create a standardized method to communicate findings of coronary CT angiography (coronary CTA) in order to facilitate decision-making regarding further patient management. The suggested CAD-RADS classification is applied on a per-patient basis and represents the highest-grade coronary artery lesion documented by coronary CTA. It ranges from CAD-RADS 0 (Zero) for the complete absence of stenosis and plaque to CAD-RADS 5 for the presence of at least one totally occluded coronary artery and should always be interpreted in conjunction with the impression found in the report. Specific recommendations are provided for further management of patients with stable or acute chest pain based on the CAD-RADS classification. The main goal of CAD-RADS is to standardize reporting of coronary CTA results and to facilitate communication of test results to referring physicians along with suggestions for subsequent patient management. In addition, CAD-RADS will provide a framework of standardization that may benefit education, research, peer-review and quality assurance with the potential to ultimately result in improved quality of care. Copyright © 2016 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

  14. Ligand-Based Pharmacophore Modeling and Virtual Screening of RAD9 Inhibitors

    Directory of Open Access Journals (Sweden)

    Nirmal K. Prasad

    2013-01-01

    Full Text Available Human RAD9 is a key cell-cycle checkpoint protein that participates in DNA repair, activation of multiple cell cycle phase checkpoints, and apoptosis. Aberrant RAD9 expression has been linked to breast, lung, thyroid, skin, and prostate tumorigenesis. Overexpression of RAD9 interacts with BCL-2 proteins and blocks the binding sites of BCL-2 family proteins to interact with chemotherapeutic drugs and leads to drug resistance. Focusing on this interaction, the present study was designed to identify the interaction sites of RAD9 to bind BCL-2 protein and also to inhibit RAD9-BCL-2 interactions by designing novel small molecule inhibitors using pharmacophore modeling and to restore BCL-2 for interacting with anticancer drugs. The bioactive molecules of natural origin act as excellent leads for new drug development. Thus, in the present study, we used the compounds of natural origin like camptothecin, ascididemin, and Dolastatin and also compared them with synthetic molecule NSC15520. The results revealed that camptothecin can act as an effective inhibitor among all the ligands taken and can be used as an RAD9 inhibitor. The amino acids ARG45 and ALA134 of RAD9 protein are interacting commonly with the drugs and BCL-2 protein.

  15. XRCC3 and RAD51 expression are associated with clinical factors in breast cancer.

    Directory of Open Access Journals (Sweden)

    Jia Hu

    Full Text Available AIMS: XRCC3 and RAD51 are two important members in homologous recombination repair pathway. This study was performed to detect the expressions of these two molecules in breast cancer and explore their correlations with clinicopathological factors. METHODS AND RESULTS: Immunohistochemistry was used to detect protein expressions of XRCC3 and RAD51 in 248 cases of breast cancer tissue and 78 cases of adjacent non-cancerous tissue. Data showed that expressions for both XRCC3 and RAD51 were significantly increased in breast cancer. High XRCC3 expression was associated with large tumor size and positive PR and HER2 status, while high RAD51 expression was associated with axillary lymph node metastasis and positive PR and HER2 status. The result of multivariate analysis demonstrated that HER2, PR and RAD51 were significantly association with XRCC3. And besides XRCC3, axillary lymph node metastasis and PR were significantly correlated with RAD51. CONCLUSIONS: XRCC3 and RAD51 were significantly associated with clinicopathological factors and they might play important roles in the development and progress of breast cancer.

  16. Development of Small Molecules that Specifically Inhibit the D-loop Activity of RAD51.

    Science.gov (United States)

    Lv, Wei; Budke, Brian; Pawlowski, Michal; Connell, Philip P; Kozikowski, Alan P

    2016-05-26

    RAD51 is the central protein in homologous recombination (HR) DNA repair and represents a therapeutic target in oncology. Herein we report a novel class of RAD51 inhibitors that were identified by high throughput screening. In contrast to many previously reported RAD51 inhibitors, our lead compound 1 is capable of blocking RAD51-mediated D-loop formation (IC50 21.3 ± 7.8 μM) at concentrations that do not influence RAD51 binding to ssDNA. In human cells, 1 inhibits HR (IC50 13.1 ± 1.6 μM) without blocking RAD51's ability to assemble into subnuclear foci at sites of DNA damage. We determined that the active constituent of 1 is actually an oxidized derivative (termed RI(dl)-1 or 8) of the original screening compound. Our SAR campaign also yielded RI(dl)-2 (hereafter termed 9h), which effectively blocks RAD51's D-loop activity in biochemical systems (IC50 11.1 ± 1.3 μM) and inhibits HR activity in human cells (IC50 3.0 ± 1.8 μM).

  17. Characterisation of the promoter region of the human DNA-repair gene Rad51.

    Science.gov (United States)

    Hasselbach, L; Haase, S; Fischer, D; Kolberg, H C; Stürzbecher, H W

    2005-01-01

    Regulatory elements of the 5'-flanking region of the DNA-repair gene Rad51 were analysed to characterise pathological alterations of Rad51 mRNA expression during tumour development. Various fragments of the Rad51 promoter were cloned into the pGL3 reporter vector and the respective promoter activity was determined by luciferase assays in transfected U2-OS cells. Transcription factor binding was identified using Protein/DNA arrays. The region encompassing base pairs -204 to -58 was identified as crucial for Rad51 gene transcription. Down regulator sequences are present upstream (-305 to -204) and downstream (-48 and +204) of this core promoter element. Promoter activity is significantly enhanced by substituting G at the polymorphic positions +135 and +172 for C and T, respectively. Transcription factors Ets1/PEA3, E2F1, p53, EGR1, and Stat5 were identified as relevant for regulating expression of Rad51. We identified three separate cis-sequence elements within the Rad51 transcriptional promoter, one ensuring basal levels of expression and two elements limiting expression to relatively low levels. The characterisation of transcription factor binding might help to explain high-level expression of Rad51 in a variety of solid tumours. The polymorphic sites appear important for the increased risk of breast and/or ovarian cancer for BRCA2 mutation carriers.

  18. A Synthetic Interaction between CDC20 and RAD4 in Saccharomyces cerevisiae upon UV Irradiation

    Directory of Open Access Journals (Sweden)

    Bernadette Connors

    2014-01-01

    Full Text Available Regulation of DNA repair can be achieved through ubiquitin-mediated degradation of transiently induced proteins. In Saccharomyces cerevisiae, Rad4 is involved in damage recognition during nucleotide excision repair (NER and, in conjunction with Rad23, recruits other proteins to the site of damage. We identified a synthetic interaction upon UV exposure between Rad4 and Cdc20, a protein that modulates the activity of the anaphase promoting complex (APC/C, a multisubunit E3 ubiquitin ligase complex. The moderately UV sensitive Δrad4 strain became highly sensitive when cdc20-1 was present, and was rescued by overexpression of CDC20. The double mutant is also deficient in elicting RNR3-lacZ transcription upon exposure to UV irradiation or 4-NQO compared with the Δrad4 single mutant. We demonstrate that the Δrad4/cdc20-1 double mutant is defective in double strand break repair by way of a plasmid end-joining assay, indicating that Rad4 acts to ensure that damaged DNA is repaired via a Cdc20-mediated mechanism. This study is the first to present evidence that Cdc20 may play a role in the degradation of proteins involved in nucleotide excision repair.

  19. Heat induction of a novel Rad9 variant from a cryptic translation initiation site reduces mitotic commitment.

    Science.gov (United States)

    Janes, Simon; Schmidt, Ulrike; Ashour Garrido, Karim; Ney, Nadja; Concilio, Susanna; Zekri, Mohamed; Caspari, Thomas

    2012-10-01

    Exposure of human cells to heat switches the activating signal of the DNA damage checkpoint from genotoxic to temperature stress. This change reduces mitotic commitment at the expense of DNA break repair. The thermal alterations behind this switch remain elusive despite the successful use of heat to sensitise cancer cells to DNA breaks. Rad9 is a highly conserved subunit of the Rad9-Rad1-Hus1 (9-1-1) checkpoint-clamp that is loaded by Rad17 onto damaged chromatin. At the DNA, Rad9 activates the checkpoint kinases Rad3(ATR) and Chk1 to arrest cells in G2. Using Schizosaccharomyces pombe as a model eukaryote, we discovered a new variant of Rad9, Rad9-M50, whose expression is specifically induced by heat. High temperatures promote alternative translation from a cryptic initiation codon at methionine-50. This process is restricted to cycling cells and is independent of the temperature-sensing mitogen-activated protein kinase (MAPK) pathway. While full-length Rad9 delays mitosis in the presence of DNA lesions, Rad9-M50 functions in a remodelled checkpoint pathway to reduce mitotic commitment at elevated temperatures. This remodelled pathway still relies on Rad1 and Hus1, but acts independently of Rad17. Heat-induction of Rad9-M50 ensures that the kinase Chk1 remains in a hypo-phosphorylated state. Elevated temperatures specifically reverse the DNA-damage-induced modification of Chk1 in a manner dependent on Rad9-M50. Taken together, heat reprogrammes the DNA damage checkpoint at the level of Chk1 by inducing a Rad9 variant that can act outside of the canonical 9-1-1 complex.

  20. Loss of RAD-23 Protects Against Models of Motor Neuron Disease by Enhancing Mutant Protein Clearance.

    Science.gov (United States)

    Jablonski, Angela M; Lamitina, Todd; Liachko, Nicole F; Sabatella, Mariangela; Lu, Jiayin; Zhang, Lei; Ostrow, Lyle W; Gupta, Preetika; Wu, Chia-Yen; Doshi, Shachee; Mojsilovic-Petrovic, Jelena; Lans, Hannes; Wang, Jiou; Kraemer, Brian; Kalb, Robert G

    2015-10-21

    Misfolded proteins accumulate and aggregate in neurodegenerative disease. The existence of these deposits reflects a derangement in the protein homeostasis machinery. Using a candidate gene screen, we report that loss of RAD-23 protects against the toxicity of proteins known to aggregate in amyotrophic lateral sclerosis. Loss of RAD-23 suppresses the locomotor deficit of Caenorhabditis elegans engineered to express mutTDP-43 or mutSOD1 and also protects against aging and proteotoxic insults. Knockdown of RAD-23 is further neuroprotective against the toxicity of SOD1 and TDP-43 expression in mammalian neurons. Biochemical investigation indicates that RAD-23 modifies mutTDP-43 and mutSOD1 abundance, solubility, and turnover in association with altering the ubiquitination status of these substrates. In human amyotrophic lateral sclerosis spinal cord, we find that RAD-23 abundance is increased and RAD-23 is mislocalized within motor neurons. We propose a novel pathophysiological function for RAD-23 in the stabilization of mutated proteins that cause neurodegeneration. In this work, we identify RAD-23, a component of the protein homeostasis network and nucleotide excision repair pathway, as a modifier of the toxicity of two disease-causing, misfolding-prone proteins, SOD1 and TDP-43. Reducing the abundance of RAD-23 accelerates the degradation of mutant SOD1 and TDP-43 and reduces the cellular content of the toxic species. The existence of endogenous proteins that act as "anti-chaperones" uncovers new and general targets for therapeutic intervention. Copyright © 2015 the authors 0270-6474/15/3514286-21$15.00/0.

  1. Arabidopsis RAD51C gene is important for homologous recombination in meiosis and mitosis.

    Science.gov (United States)

    Abe, Kiyomi; Osakabe, Keishi; Nakayama, Shigeki; Endo, Masaki; Tagiri, Akemi; Todoriki, Setsuko; Ichikawa, Hiroaki; Toki, Seiichi

    2005-10-01

    Rad51 is a homolog of the bacterial RecA recombinase, and a key factor in homologous recombination in eukaryotes. Rad51 paralogs have been identified from yeast to vertebrates. Rad51 paralogs are thought to play an important role in the assembly or stabilization of Rad51 that promotes homologous pairing and strand exchange reactions. We previously characterized two RAD51 paralogous genes in Arabidopsis (Arabidopsis thaliana) named AtRAD51C and AtXRCC3, which are homologs of human RAD51C and XRCC3, respectively, and described the interaction of their products in a yeast two-hybrid system. Recent studies showed the involvement of AtXrcc3 in DNA repair and functional role in meiosis. To determine the role of RAD51C in meiotic and mitotic recombination in higher plants, we characterized a T-DNA insertion mutant of AtRAD51C. Although the atrad51C mutant grew normally during vegetative developmental stage, the mutant produced aborted siliques, and their anthers did not contain mature pollen grains. Crossing of the mutant with wild-type plants showed defective male and female gametogeneses as evidenced by lack of seed production. Furthermore, meiosis was severely disturbed in the mutant. The atrad51C mutant also showed increased sensitivity to gamma-irradiation and cisplatin, which are known to induce double-strand DNA breaks. The efficiency of homologous recombination in somatic cells in the mutant was markedly reduced relative to that in wild-type plants.

  2. Secondary Somatic Mutations Restoring RAD51C and RAD51D Associated with Acquired Resistance to the PARP Inhibitor Rucaparib in High-Grade Ovarian Carcinoma.

    Science.gov (United States)

    Kondrashova, Olga; Nguyen, Minh; Shield-Artin, Kristy; Tinker, Anna V; Teng, Nelson N H; Harrell, Maria I; Kuiper, Michael J; Ho, Gwo-Yaw; Barker, Holly; Jasin, Maria; Prakash, Rohit; Kass, Elizabeth M; Sullivan, Meghan R; Brunette, Gregory J; Bernstein, Kara A; Coleman, Robert L; Floquet, Anne; Friedlander, Michael; Kichenadasse, Ganessan; O'Malley, David M; Oza, Amit; Sun, James; Robillard, Liliane; Maloney, Lara; Bowtell, David; Giordano, Heidi; Wakefield, Matthew J; Kaufmann, Scott H; Simmons, Andrew D; Harding, Thomas C; Raponi, Mitch; McNeish, Iain A; Swisher, Elizabeth M; Lin, Kevin K; Scott, Clare L

    2017-06-06

    High-grade epithelial ovarian carcinomas containing mutated BRCA1 or BRCA2 (BRCA1/2) homologous recombination (HR) genes are sensitive to platinum-based chemotherapy and PARP inhibitors (PARPi), while restoration of HR function due to secondary mutations in BRCA1/2 has been recognized as an important resistance mechanism. We sequenced core HR pathway genes in 12 pairs of pretreatment and postprogression tumor biopsy samples collected from patients in ARIEL2 Part 1, a phase II study of the PARPi rucaparib as treatment for platinum-sensitive, relapsed ovarian carcinoma. In 6 of 12 pretreatment biopsies, a truncation mutation in BRCA1, RAD51C, or RAD51D was identified. In five of six paired postprogression biopsies, one or more secondary mutations restored the open reading frame. Four distinct secondary mutations and spatial heterogeneity were observed for RAD51CIn vitro complementation assays and a patient-derived xenograft, as well as predictive molecular modeling, confirmed that resistance to rucaparib was associated with secondary mutations.SIGNIFICANCE: Analyses of primary and secondary mutations in RAD51C and RAD51D provide evidence for these primary mutations in conferring PARPi sensitivity and secondary mutations as a mechanism of acquired PARPi resistance. PARPi resistance due to secondary mutations underpins the need for early delivery of PARPi therapy and for combination strategies. Cancer Discov; 7(9); 1-15. ©2017 AACR. ©2017 American Association for Cancer Research.

  3. Rad52 multimerization is important for its nuclear localization in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Plate, Iben; Albertsen, Line; Lisby, Michael

    2008-01-01

    Rad52 is essential for all homologous recombination and DNA double strand break repair events in Saccharomyces cerevisiae. This protein is multifunctional and contains several domains that allow it to interact with DNA as well as with different repair proteins. However, it has been unclear how Rad......52 enters the nucleus. In the present study, we have used a combination of mutagenesis and sequence analysis to show that Rad52 from S. cerevisiae contains a single functional pat7 type NLS essential for its nuclear localization. The region containing the NLS seems only to be involved in nuclear...

  4. Expressiveness of the Breast Imaging Reporting and Database System (BI-RADS).

    OpenAIRE

    Starren, J.; Johnson, S.M.

    1997-01-01

    The Breast Imaging Reporting and Database System (BI-RADS) was developed by the American College of Radiology and is used by a number of computerized mammography tracking systems. The ability of BI-RADS to encode the data contained in 300 mammography reports at the Columbia-Presbyterian Medical Center was examined. BI-RADS was able to encode normal reports and "special masses" (such as lymph nodes) without difficulty. However, none of the general masses and only 17% of the calcifications coul...

  5. Expressiveness of the Breast Imaging Reporting and Database System (BI-RADS).

    OpenAIRE

    Starren, J.; Johnson, S.M.

    1997-01-01

    The Breast Imaging Reporting and Database System (BI-RADS) was developed by the American College of Radiology and is used by a number of computerized mammography tracking systems. The ability of BI-RADS to encode the data contained in 300 mammography reports at the Columbia-Presbyterian Medical Center was examined. BI-RADS was able to encode normal reports and "special masses" (such as lymph nodes) without difficulty. However, none of the general masses and only 17% of the calcifications coul...

  6. Germline RAD51B truncating mutation in a family with cutaneous melanoma

    DEFF Research Database (Denmark)

    Wadt, Karin A W; Aoude, Lauren G; Golmard, Lisa

    2015-01-01

    Known melanoma predisposition genes only account for around 40% of high-density melanoma families. Other rare mutations are likely to play a role in melanoma predisposition. RAD51B plays an important role in DNA repair through homologous recombination, and inactivation of RAD51B has been implicated...... this case report is consistent with melanoma being part of the RAD51B cancer spectrum further population-based screening of large case-control sample series will be needed to definitively establish if this is the case....

  7. Contribution à l'étude structurale par PY/CG-SM de la matière organique liée aux particules fines (0-50 µm dans quelques sols sous formations naturelles de longue durée au Burkina Faso

    Directory of Open Access Journals (Sweden)

    Pallo, FJP.

    2011-01-01

    Full Text Available Contribution to the study by PY/GC-MS of organic matter linked to fine particles (0-50 µm in some soils under long-term natural formations in Burkina Faso. The study aims to enhance the knowledge on organic matter of Arenosols, Ferralsols, and Cambisols in Burkina Faso. It deals with the distribution of C and N in three particles size fractions and is focused on the structures of organic matter linked to the (0-50 µm fraction. The results showed that total organic matter was lower than 2% in all soil units. More than 70% of total carbon were held by the finest fraction. The main products released by PY/GC-MS technique of the (0-50 µm fraction were lignin derived compounds, non lignin derived aromatic compounds, carbohydrates derived compounds, fatty acids methyl esters and nitrogen derived compounds. The aliphatic compounds ranged from C12 to C18, C16 being the dominant one. The aliphatic compounds were negatively correlated with the aromatic compounds. A positive correlation was observed between the nitrogen derived compounds and the amounts of clay. On the other hand, the carbohydrates derived compounds were negatively correlated with clay particles. Furthermore, the study pointed out some different structures of lignin such as syringyl, guaiacyl, and p.hydrophenyl. Depending on the nature of wood (hard wood, soft wood and grasses, they reflected the composition of vegetation on the studied sites. Therefore, PY/GC-MS technique was efficient for structural characterization of low amounts of soil organic matter.

  8. Microwave-absorbing properties of Ni{sub 0.50-x}Zn{sub 0.50-x}Me{sub 2x}Fe{sub 2}O{sub 4} (Me=Cu, Mn, Mg) ferrite-wax composite in X-band frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Bueno, Alexandre R. [DCMM, Pontificia Universidade Catolica do Rio de Janeiro-R. Marques de Sao Vicente, 225, 22453-900, Rio de Janeiro, RJ (Brazil)], E-mail: arbueno@rdc.puc-rio.br; Gregori, Maria L. [IPqM-Instituto de Pesquisas da Marinha-Rua Ipiru, Praia da Bica, Ilha do Governador, 21931-090, Rio de Janeiro, RJ (Brazil); Nobrega, Maria C.S. [COPPE/UFRJ PEMM-Universidade Federal do Rio de Janeiro-Ilha do Fundao, C.P. 68505, 21945-970, Rio de Janeiro, RJ (Brazil)

    2008-03-15

    Ni{sub 0.5-x}Zn{sub 0.5-x}Me{sub 2x}Fe{sub 2}O{sub 4} (Me=Cu, Mg, Mn; x=0.00 and 0.10) ferrite powders were prepared by the nitrate-citrate precursor method and investigated as a radar absorbing material (RAM) in a frequency range of 8-12 GHz (X-band). The effects of Cu{sup 2+}, Mn{sup 2+} and Mg{sup 2+} substitution on the microwave-absorbing feature, the complex permeability ({mu}{sub r}*) and the complex permittivity ({epsilon}{sub r}*) were investigated. The microwave-absorbing properties were studied as a function of frequency, Me{sup 2+} content, and thickness of absorber. The adoption of Cu{sup 2+} and Mn{sup 2+} substitution was found to improve the microwave absorption and bandwidth, while the substitution of Mg{sup 2+} was found to reduce the microwave absorption in relation to non-substituted NiZn ferrite.

  9. The role of Candida albicans homologous recombination factors Rad54 and Rdh54 in DNA damage sensitivity

    Directory of Open Access Journals (Sweden)

    White Theodore C

    2011-09-01

    Full Text Available Abstract Background The fungal pathogen Candida albicans is frequently seen in immune suppressed patients, and resistance to one of the most widely used antifungals, fluconazole (FLC, can evolve rapidly. In recent years it has become clear that plasticity of the Candida albicans genome contributes to drug resistance through loss of heterozygosity (LOH at resistance genes and gross chromosomal rearrangements that amplify gene copy number of resistance associated genes. This study addresses the role of the homologous recombination factors Rad54 and Rdh54 in cell growth, DNA damage and FLC resistance in Candida albicans. Results The data presented here support a role for homologous recombination in cell growth and DNA damage sensitivity, as Candida albicans rad54Δ/rad54Δ mutants were hypersensitive to MMS and menadione, and had an aberrant cell and nuclear morphology. The Candida albicans rad54Δ/rad54Δ mutant was defective in invasion of Spider agar, presumably due to the altered cellular morphology. In contrast, mutation of the related gene RDH54 did not contribute significantly to DNA damage resistance and cell growth, and deletion of either Candida albicans RAD54 or Candida albicans RDH54 did not alter FLC susceptibility. Conclusions Together, these results support a role for homologous recombination in genome stability under nondamaging conditions. The nuclear morphology defects in the rad54Δ/rad54Δ mutants show that Rad54 performs an essential role during mitotic growth and that in its absence, cells arrest in G2. The viability of the single mutant rad54Δ/rad54Δ and the inability to construct the double mutant rad54Δ/rad54Δ rdh54Δ/rdh54Δ suggests that Rdh54 can partially compensate for Rad54 during mitotic growth.

  10. Breast imaging reporting and data system (BI-RADS) lexicon for breast MRI: Interobserver variability in the description and assignment of BI-RADS category

    Energy Technology Data Exchange (ETDEWEB)

    El Khoury, Mona, E-mail: monelkhoury@gmail.com [Centre Hospitalier Universitaire de Montréal, Breast Centre, Radiology Department, 3840 Rue Saint Urbain, Montréal, QC H2W1T8 (Canada); Lalonde, Lucie; David, Julie; Labelle, Maude [Centre Hospitalier Universitaire de Montréal, Breast Centre, Radiology Department, 3840 Rue Saint Urbain, Montréal, QC H2W1T8 (Canada); Mesurolle, Benoit [Centre Hospitalier Universitaire de McGill, Cedar Breast Centre, Radiology Department, 687 Pine Avenue West, Montreal, QC H3A1A1 (Canada); Trop, Isabelle [Centre Hospitalier Universitaire de Montréal, Breast Centre, Radiology Department, 3840 Rue Saint Urbain, Montréal, QC H2W1T8 (Canada)

    2015-01-15

    Highlights: • The use of BI-RADS lexicon in interpreting breast MRI examinations is beneficial. • Our study shows: (a) moderate to substantial agreement between observers and (b) better agreement in interpreting mass than non-mass enhancement (NME). • Careful analysis of the NME should be done to help detect cancer as early as possible. - Abstract: Purpose: To retrospectively evaluate interobserver variability between breast radiologists when describing abnormal enhancement on breast MR examinations and assigning a BI-RADS category using the Breast Imaging Reporting and Data System (BI-RADS) terminology. Materials and methods: Five breast radiologists blinded to patients’ medical history and pathologic results retrospectively and independently reviewed 257 abnormal areas of enhancement on breast MRI performed in 173 women. Each radiologist described the focal enhancement using BI-RADS terminology and assigned a final BI-RADS category. Krippendorff's α coefficient of agreement was used to asses interobserver variability. Results: All radiologists agreed on the morphology of enhancement in 183/257 (71%) lesions, yielding a substantial agreement (Krippendorff's α = 0.71). Moderate agreement was obtained for mass descriptors – shape, margins and internal enhancement – (α = 0.55, 0.51 and 0.45 respectively) and NME (non-mass enhancement) descriptors – distribution and internal enhancement – (α = 0.54 and 0.43). Overall substantial agreement was obtained for BI-RADS category assignment (α = 0.71). It was however only moderate (α = 0.38) for NME compared to mass (α = 0.80). Conclusion: Our study shows good agreement in describing mass and NME on a breast MR examination but a better agreement in predicting malignancy for mass than NME.

  11. Bible and Philology: Gerhard von Rad regarding the Wisdom Books

    Directory of Open Access Journals (Sweden)

    Norma Haydeé Lase

    2015-04-01

    Full Text Available Theology, through its history, has always been related to Philology, because its source is the Holy Scriptures. This reason has stimulated my further consideration of the exegeta Gerhard von Rad “Wisdom in Israel” a “symbol” of modern interest for the Wisdom books. Inserted in the philologic German trend of the history of tradition and history of editing and forms, it is opposed to positivists interpretation and installs a new comprehension of the OT traditions. Its hermeneutica, without deteriorating the historical criticism, gives first hand priority to the message that the scriptural brands patentize as a twist of an organization in constant growth. However, the love of live words, which is considered by the philologist, make him capable to have a wide effect of the methodological tools, and in this way; unravel the secrets of the world of wisdom. Now in the threshold of Christianism, Wisdom books prepare the adequate opening to receive the “new Wine” in “new containers”. Also, today, philology and wisdom summon us to go along with this moment of the History of Salvation with the necessary instruments and ancient breeding by old and modern wisemen.

  12. RadNet Map Interface for Near-Real-Time Radiation Monitoring Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — RadNet is a national network of monitoring stations that regularly collect air, precipitation, drinking water, and milk samples for analysis of radioactivity. The...

  13. Variations of dose rate observed by MSL/RAD in transit to Mars

    CERN Document Server

    Guo, Jingnan; Wimmer-Schweingruber, Robert F; Hassler, Donald M; Posner, Arik; Heber, Bernd; Köhler, Jan; Rafkin, Scot; Ehresmann, Bent; Appel, Jan K; Böhm, Eckart; Böttcher, Stephan; Burmeister, Sönke; Brinza, David E; Lohf, Henning; Martin, Cesar; Reitz, Günther

    2015-01-01

    Aims: To predict the cruise radiation environment related to future human missions to Mars, the correlation between solar modulation potential and the dose rate measured by the Radiation Assessment Detector (RAD) has been analyzed and empirical models have been employed to quantify this correlation. Methods: The instrument RAD, onboard Mars Science Laboratory's (MSL) rover Curiosity, measures a broad spectrum of energetic particles along with the radiation dose rate during the 253-day cruise phase as well as on the surface of Mars. With these first ever measurements inside a spacecraft from Earth to Mars, RAD observed the impulsive enhancement of dose rate during solar particle events as well as a gradual evolution of the galactic cosmic ray (GCR) induced radiation dose rate due to the modulation of the primary GCR flux by the solar magnetic field, which correlates with long-term solar activities and heliospheric rotation. Results: We analyzed the dependence of the dose rate measured by RAD on solar modulatio...

  14. Sol-Rad Net Flux (L 1.0, 1.5, 2.0)

    Data.gov (United States)

    National Aeronautics and Space Administration — SolRad-Net (Solar Radiation Network) is an established network of ground-based sensors providing high-frequency solar flux measurements in quasi-realtime to the...

  15. UPLC®-RAD the new standard in quality control of PET radiopharmaceutical

    NARCIS (Netherlands)

    Maas, B.; Zijlma, R.; Bannink, A.; Lub-De Hooge, M.; Elsinga, P.H.; Dierckx, R.A.J.O.; Boersma, H.H.; Luurtsema, G.

    2013-01-01

    Objectives: Good Manufacturing Practice (GMP) compliant productions require validated, quality control procedures of the radiopharmaceutical. Quality control of the final product is conventionally performed by High Performance Liquid Chromatography (HPLC) with UV and radioactivity (RAD) detection. T

  16. RADS Version 4: An Efficient Way to Analyse the Multi-Mission Altimeter Database

    Science.gov (United States)

    Scharroo, Remko; Leuliette, Eric; Naeije, Marc; Martin-Puig, Cristina; Pires, Nelson

    2016-08-01

    The Radar Altimeter Database System (RADS) has grown to become a mature altimeter database. Over the last 18 years it is continuously being developed, first at Delft University of Technology, now also at the National Oceanic and Atmospheric Administration (NOAA) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT).RADS now serves as a fundamental Climate Data Record for sea level. Because of the multiple users involved in vetting the data and the regular updates to the database, RADS is one of the most accurate and complete databases of satellite altimeter data around.RADS version 4 is a major change from the previous version. While the database is compatible with both software versions, the new software provides new tools, allows easier expansion, and has a better and more standardised interface.

  17. Prostate MRI based on PI-RADS version 2: how we review and report

    National Research Council Canada - National Science Library

    Philipp Steiger; Harriet C Thoeny

    2016-01-01

    ... stratification in patients with suspected cancer in treatment naive prostate glands. It does not address detection of recurrence, progression during active surveillance and evaluation of other parts of the body. PI-RADS(TM...

  18. Rad-hard Location and Attitude Module (R-LAM) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — R-LAM (Rad-hard Location and Attitude Module), promises a new generation of both integrated navigation modules and stand-alone navigation subsystems including...

  19. Packaging Effects on RadFET Sensors for High Energy Physics Experiments

    CERN Document Server

    Mekki, J; Glaser, M; Guatelli, S; Moll, M; Pia, M G; Ravotti, F

    2009-01-01

    RadFETs in customized chip carrier packages are installed in the LHC Experiments as radiation monitors. The package influence on the dose measurement in the complex LHC radiation environment is evaluated using Geant4 simulations and experimental data.

  20. Wide Temperature Rad-Hard ASIC for Process Control of a Fuel Cell System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ridgetop Group developed a top-level design of a rad-hard application-specific integrated circuit (ASIC) for spacecraft power management that is functional over a...

  1. Rad10 exhibits lesion-dependent genetic requirements for recruitment to DNA double-strand breaks in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Moore, Destaye M; Karlin, Justin; González-Barrera, Sergio

    2009-01-01

    In the yeast Saccharomyces cerevisiae, the Rad1-Rad10 protein complex participates in nucleotide excision repair (NER) and homologous recombination (HR). During HR, the Rad1-Rad10 endonuclease cleaves 3' branches of DNA and aberrant 3' DNA ends that are refractory to other 3' processing enzymes. ...

  2. Physical and microstructural characterization of La{sub 0,60}Sr{sub 0,40}Co{sub 0,20}Fe{sub 0,80}O{sub 3-δ} and Ba{sub 0,50}Sr{sub 0,50}Co{sub 0,80}Fe{sub 0,20}O{sub 3-δ} ceramics; Caracterizacao fisica e microestrutural de ceramicas constituidas de La{sub 0,60}Sr{sub 0,40}Co{sub 0,20}Fe{sub 0,80}O{sub 3-δ} e Ba{sub 0,50}Sr{sub 0,50}Co{sub 0,80}Fe{sub 0,20}O{sub 3-δ}

    Energy Technology Data Exchange (ETDEWEB)

    Bonturim, E.; Vargas, R.A.; Andreoli, M.; Chiba, R.; Seo, E.S.M., E-mail: ebonturim@ipen.br, E-mail: ravargas@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP/CCTM/SOFC), Sao Paulo, SP (Brazil). Centro de Ciencia e Tecnologia de Materiais. Lab. de Insumos e Componentes

    2012-07-01

    The La{sub 0,60}Sr{sub 0,40}Co{sub 0,20}Fe{sub 0,80}O{sub 3-δ} (LSCF) and Ba{sub 0,50}Sr{sub 0,50}Co{sub 0,80}Fe{sub 0,20}O{sub 3-δ} (BSCF) oxides are studied as cathodes in Solid Oxide Fuel Cell. The objective of this study is to characterize physically and microstructural these materials. The LSCF was synthesized by citrate technique and BSCF for citrates-EDTA, processed under the same conditions. The characterizations of ceramics were performed by X-ray diffraction, dilatometry, scanning electron microscopy and apparent density for Archimedes principle. According to the diffraction technique, confirmed the presence of single phases for LSCF to 800 deg C and BSCF to 900 deg C, with orthorhombic and cubic structures, respectively. For dilatometry were determined the sintering temperatures, near of 1050 deg C to BSCF and 1100 deg C to LSCF. The sintered micrographs at 1000, 1050 and 1100 deg C for 2 hours showed homogeneity microstructure, containing porosity and, attacked thermally, a homogeneous distribution of grains. Finally by bulk density, was estimated porosity between 20 and 30%. (author)

  3. Ultrasonic features of BI-RADS 4 level breast lesions%超声诊断BI-RADS4级乳腺病灶

    Institute of Scientific and Technical Information of China (English)

    李艾卓; 王学梅; 耿晶; 张义侠; 李银燕

    2011-01-01

    Objective To investigate the value of ultrasound in diagnosis of BI-RADS 4 level breast lesions. Methods Three hundred thirty-eight patients with 405 breast lesions underwent ultrasound examination! And the lesions were diagnosed as Bl-RADS 4 level. The results were compared with surgery and pathological findings. Results The diagnostic specificity of "spiculation", "posterior echo attenuation" and "RI≥0. 7" to BI-RADS 4 level breast cancer was 98. 36% (299/ 304), 90.12% (274/304) and 86. 24% (262/304), respectively. Conclusion The findings of "spiculaiton", "posterior echo attenuation" and "RI≥0. 7" are the most specific ultrasonic signs of BI-RADS 4 level breast lesions that indicating the grading of BI-RADS 4 level to 4C.%目的 探讨恶性超声征象诊断BI-RADS 4级乳腺病变的价值.方法 回顾性分析术前应用超声诊断为BI-RADS 4级的乳腺病变患者338例(405个病灶),将超声所见与手术病理结果进行对照.结果 “毛刺征”、“后方回声衰减”及“RI值≥0.7”为诊断特异度较高的超声征象,对乳腺癌的诊断特异度分别为98.36%(299/304)、90.12%(274/304)和86.24%(262/304).结论 “毛刺征”、“后方回声衰减”及“RI值≥0.7”为特异度较高的超声征象,当出现这3个征象时,BI-RADS 4级评分倾向于4C级.

  4. Specific interaction between DNA polymerase II (PolD) and RadB, a Rad51/Dmc1 homolog, in Pyrococcus furiosus.

    OpenAIRE

    Hayashi, I; Morikawa, K; ISHINO, Y.

    1999-01-01

    Pyrococcus furiosus has an operon containing the DNA polymerase II (PolD) gene and three other genes. Using a two-hybrid screening to examine the interactions of the proteins encoded by the operon, we identified a specific interaction between the second subunit of PolD (DP1) and a Rad51/Dmc1 homologous protein (RadB). To ensure the specific interaction between these two proteins, each gene in the operon was expressed in Escherichia coli or insect cells separately and the products were purifie...

  5. Specific interaction between DNA polymerase II (PolD) and RadB, a Rad51/Dmc1 homolog, in Pyrococcus furiosus.

    OpenAIRE

    I. Hayashi; Morikawa, K.; Ishino, Y

    1999-01-01

    Pyrococcus furiosus has an operon containing the DNA polymerase II (PolD) gene and three other genes. Using a two-hybrid screening to examine the interactions of the proteins encoded by the operon, we identified a specific interaction between the second subunit of PolD (DP1) and a Rad51/Dmc1 homologous protein (RadB). To ensure the specific interaction between these two proteins, each gene in the operon was expressed in Escherichia coli or insect cells separately and the products were purifie...

  6. RAD tag sequencing as a source of SNP markers in Cynara cardunculus L.

    OpenAIRE

    Scaglione Davide; Acquadro Alberto; Portis Ezio; Tirone Matteo; Knapp Steven J; Lanteri Sergio

    2012-01-01

    Abstract Background The globe artichoke (Cynara cardunculus L. var. scolymus) genome is relatively poorly explored, especially compared to those of the other major Asteraceae crops sunflower and lettuce. No SNP markers are in the public domain. We have combined the recently developed restriction-site associated DNA (RAD) approach with the Illumina DNA sequencing platform to effect the rapid and mass discovery of SNP markers for C. cardunculus. Results RAD tags were sequenced from the genomic ...

  7. Functional Analysis of the Bacteriophage T4 Rad50 Homolog (gp46) Coiled-coil Domain.

    Science.gov (United States)

    Barfoot, Tasida; Herdendorf, Timothy J; Behning, Bryanna R; Stohr, Bradley A; Gao, Yang; Kreuzer, Kenneth N; Nelson, Scott W

    2015-09-25

    Rad50 and Mre11 form a complex involved in the detection and processing of DNA double strand breaks. Rad50 contains an anti-parallel coiled-coil with two absolutely conserved cysteine residues at its apex. These cysteine residues serve as a dimerization domain and bind a Zn(2+) cation in a tetrathiolate coordination complex known as the zinc-hook. Mutation of the zinc-hook in bacteriophage T4 is lethal, indicating the ability to bind Zn(2+) is critical for the functioning of the MR complex. In vitro, we found that complex formation between Rad50 and a peptide corresponding to the C-terminal domain of Mre11 enhances the ATPase activity of Rad50, supporting the hypothesis that the coiled-coil is a major conduit for communication between Mre11 and Rad50. We constructed mutations to perturb this domain in the bacteriophage T4 Rad50 homolog. Deletion of the Rad50 coiled-coil and zinc-hook eliminates Mre11 binding and ATPase activation but does not affect its basal activity. Mutation of the zinc-hook or disruption of the coiled-coil does not affect Mre11 or DNA binding, but their activation of Rad50 ATPase activity is abolished. Although these mutants excise a single nucleotide at a normal rate, they lack processivity and have reduced repetitive exonuclease rates. Restricting the mobility of the coiled-coil eliminates ATPase activation and repetitive exonuclease activity, but the ability to support single nucleotide excision is retained. These results suggest that the coiled-coiled domain adopts at least two conformations throughout the ATPase/nuclease cycle, with one conformation supporting enhanced ATPase activity and processivity and the other supporting nucleotide excision.

  8. Practical and illustrated summary of updated BI-RADS for ultrasonography

    Directory of Open Access Journals (Sweden)

    Jiyon Lee

    2017-01-01

    Full Text Available The American College of Radiology released the fifth edition of the Breast Imaging-Reporting and Data System (BI-RADS in 2014 (copyright 2013, which includes the expanded second edition of the ultrasound BI-RADS lexicon. This review provides a practical summary of the updated lexicon, including selective illustrations with original clinical images, a discussion of overarching concepts, and examples of current clinical applications.

  9. Practical and illustrated summary of updated BI-RADS for ultrasonography

    OpenAIRE

    Jiyon Lee

    2016-01-01

    The American College of Radiology released the fifth edition of the Breast Imaging-Reporting and Data System (BI-RADS) in 2014 (copyright 2013), which includes the expanded second edition of the ultrasound BI-RADS lexicon. This review provides a practical summary of the updated lexicon, including selective illustrations with original clinical images, a discussion of overarching concepts, and examples of current clinical applications.

  10. Practical and illustrated summary of updated BI-RADS for ultrasonography

    OpenAIRE

    Jiyon Lee

    2017-01-01

    The American College of Radiology released the fifth edition of the Breast Imaging-Reporting and Data System (BI-RADS) in 2014 (copyright 2013), which includes the expanded second edition of the ultrasound BI-RADS lexicon. This review provides a practical summary of the updated lexicon, including selective illustrations with original clinical images, a discussion of overarching concepts, and examples of current clinical applications.

  11. Positive Predictive Value of BI-RADS Categorization in an Asian Population

    Directory of Open Access Journals (Sweden)

    Yah-Yuen Tan

    2004-07-01

    Full Text Available The Breast Imaging Reporting And Data System (BI-RADS categorization of mammograms is useful in estimating the risk of malignancy, thereby guiding management decisions. However, in Asian women, in whom breast density is increased, the sensitivity of mammography is correspondingly lower. We sought to determine the positive predictive value of BI-RADS categorization for malignancy in our Asian population and, hence, its value in helping us to choose between the various modalities for breast biopsy. We retrospectively reviewed all patients with occult breast lesions detected on mammography or ultrasound who underwent needle-localization open breast biopsy (NLOB in our institution over a 6-year period. There were 470 biopsies in 427 patients; 16% of lesions were malignant. The positive predictive value of BI-RADS 4 and 5 lesions for cancer was 0.27 and 0.84, respectively. While most BI-RADS 5 mass lesions were invasive cancers, the majority of calcifications in this category were in situ carcinomas. We conclude that BI-RADS remains useful in aiding decision-making for biopsy in our Asian population. Based on positive predictive values, we recommend percutaneous breast biopsy for initial evaluation of lesions categorized as BI-RADS 4 or less. For BI-RADS 5 lesions with microcalcifications, open surgical biopsy as a diagnostic and therapeutic procedure may be more appropriate. In the case of a BI-RADS 5 lesion associated with a mass, initial percutaneous biopsy may be useful for diagnosis, followed by a planned single-stage surgical procedure as necessary.

  12. The checkpoint Saccharomyces cerevisiae Rad9 protein contains a tandem tudor domain that recognizes DNA.

    OpenAIRE

    Lancelot, Nathalie; Charier, Gaëlle; Couprie, Joël; Duband-Goulet, Isabelle; Alpha-Bazin, Béatrice; Quémeneur, Eric; Ma, Emilie; Marsolier-Kergoat, Marie-Claude; Ropars, Virginie; Charbonnier, Jean-Baptiste; Miron, Simona; Craescu, Constantin,; Callebaut, Isabelle; Gilquin, Bernard; Zinn-Justin, Sophie

    2007-01-01

    International audience; DNA damage checkpoints are signal transduction pathways that are activated after genotoxic insults to protect genomic integrity. At the site of DNA damage, 'mediator' proteins are in charge of recruiting 'signal transducers' to molecules 'sensing' the damage. Budding yeast Rad9, fission yeast Crb2 and metazoan 53BP1 are presented as mediators involved in the activation of checkpoint kinases. Here we show that, despite low sequence conservation, Rad9 exhibits a tandem t...

  13. Characterization methodology for Difficult To Measure nuclides in the Type B rad waste from the ITER

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Youngyong; Hong, Kwonpyo; Oh, Wanho; Kang, Munja; Na, Byungchan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-10-15

    In general, it is not possible to directly detect beta rays from the rad waste in the field measurement due to their extremely low penetration through the materials. Only lab-scale measurements with proper shield and detecting system are available for the nondestructive assay. However, the disposal sites in many countries require the determination of inventories of the difficult to-measure (DTM) nuclides in the waste before their acceptance for disposal. Many sites that generate rad wastes thus are adapting the indirect method to characterize the DTM nuclides in the rad waste to be disposed. The rad waste from the operation of an international thermonuclear experimental reactor (ITER) will be sent to the hot cell building (HCB) after packing it to the basket and they are then treated into the disposal form as well as characterized through the nondestructive assay. The rad waste properties from the ITER are that high density material such as a steel, a copper, and a tungsten accounts for the main substance and many nuclides due to the neutron irradiation including the DTM nuclides exists in that waste. Therefore, the ITER is also facing with the problem for the characterization of DTM nuclides. The scaling factor for the radiological relationship between the gamma and the beta nuclides is one of the indirect measurements to characterize the DTM nuclides in the waste. The methodology of the scaling factor to apply this method to the characterization the Type B rad waste from the ITER are presented in this paper. There are several types of the in-vessel components (IVCs) in a Tokamak which will be activated by neutron and they will be divided into different types of the rad waste such as the divertor cassette, blanket module, and port plugs. In this paper, the characterization of DTM nuclides will be focused on the rad waste from a blanket module out of IVCs.

  14. Characterization of Rad51 from apicomplexan parasite Toxoplasma gondii: an implication for inefficient gene targeting.

    Science.gov (United States)

    Achanta, Sita Swati; Varunan, Shalu M; Bhattacharyya, Sunanda; Bhattacharyya, Mrinal Kanti

    2012-01-01

    Repairing double strand breaks (DSBs) is absolutely essential for the survival of obligate intracellular parasite Toxoplasma gondii. Thus, DSB repair mechanisms could be excellent targets for chemotherapeutic interventions. Recent genetic and bioinformatics analyses confirm the presence of both homologous recombination (HR) as well as non homologous end joining (NHEJ) proteins in this lower eukaryote. In order to get mechanistic insights into the HR mediated DSB repair pathway in this parasite, we have characterized the key protein involved in homologous recombination, namely TgRad51, at the biochemical and genetic levels. We have purified recombinant TgRad51 protein to 99% homogeneity and have characterized it biochemically. The ATP hydrolysis activity of TgRad51 shows a higher K(M) and much lower k(cat) compared to bacterial RecA or Rad51 from other related protozoan parasites. Taking yeast as a surrogate model system we have shown that TgRad51 is less efficient in gene conversion mechanism. Further, we have found that TgRad51 mediated gene integration is more prone towards random genetic loci rather than targeted locus. We hypothesize that compromised ATPase activity of TgRad51 is responsible for inefficient gene targeting and poor gene conversion efficiency in this protozoan parasite. With increase in homologous flanking regions almost three fold increments in targeted gene integration is observed, which is similar to the trend found with ScRad51. Our findings not only help us in understanding the reason behind inefficient gene targeting in T. gondii but also could be exploited to facilitate high throughput knockout as well as epitope tagging of Toxoplasma genes.

  15. Characterization of Rad51 from apicomplexan parasite Toxoplasma gondii: an implication for inefficient gene targeting.

    Directory of Open Access Journals (Sweden)

    Sita Swati Achanta

    Full Text Available Repairing double strand breaks (DSBs is absolutely essential for the survival of obligate intracellular parasite Toxoplasma gondii. Thus, DSB repair mechanisms could be excellent targets for chemotherapeutic interventions. Recent genetic and bioinformatics analyses confirm the presence of both homologous recombination (HR as well as non homologous end joining (NHEJ proteins in this lower eukaryote. In order to get mechanistic insights into the HR mediated DSB repair pathway in this parasite, we have characterized the key protein involved in homologous recombination, namely TgRad51, at the biochemical and genetic levels. We have purified recombinant TgRad51 protein to 99% homogeneity and have characterized it biochemically. The ATP hydrolysis activity of TgRad51 shows a higher K(M and much lower k(cat compared to bacterial RecA or Rad51 from other related protozoan parasites. Taking yeast as a surrogate model system we have shown that TgRad51 is less efficient in gene conversion mechanism. Further, we have found that TgRad51 mediated gene integration is more prone towards random genetic loci rather than targeted locus. We hypothesize that compromised ATPase activity of TgRad51 is responsible for inefficient gene targeting and poor gene conversion efficiency in this protozoan parasite. With increase in homologous flanking regions almost three fold increments in targeted gene integration is observed, which is similar to the trend found with ScRad51. Our findings not only help us in understanding the reason behind inefficient gene targeting in T. gondii but also could be exploited to facilitate high throughput knockout as well as epitope tagging of Toxoplasma genes.

  16. Practical and illustrated summary of updated BI-RADS for ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ji Yon [Dept. of Radiology, NYU School of Medicine, NYU Cancer Institute, Breast Imaging Center, New York (United States)

    2017-01-15

    The American College of Radiology released the fifth edition of the Breast Imaging-Reporting and Data System (BI-RADS) in 2014 (copyright 2013), which includes the expanded second edition of the ultrasound BI-RADS lexicon. This review provides a practical summary of the updated lexicon, including selective illustrations with original clinical images, a discussion of overarching concepts, and examples of current clinical applications.

  17. The Saccharomyces cerevisiae RAD7 and RAD16 genes are required for inducible excision of endonuclease III sensitive-sites, yet are not needed for the repair of these lesions following a single UV dose.

    Science.gov (United States)

    Scott, A D; Waters, R

    1997-01-31

    The RAD7 and RAD16 genes of Saccharomyces cerevisiae have roles in the repair of UV induced CPDs in nontranscribed genes [1], and in the repair of CPDs in the nontranscribed strand of transcribed genes [2]. Previously, we identified an inducible component to nucleotide excision repair (NER), which is absent in a rad16 delta strain [3]. We have examined the repair of UV induced endonuclease III sensitive-sites (EIIISS), and have shown repair of these lesions to proceed by NER but their removal from nontranscribed regions is independent of RAD7 and RAD16. Furthermore, EIIISS are repaired with equal efficiency from both transcribed and nontranscribed genes [4]. In order to dissect the roles of RAD7 and RAD16 in the above processes we examined the repair of EIIISS in the MAT alpha and HML alpha loci, which are, respectively, transcriptionally active and inactive in alpha haploid cells. These loci have elevated levels of these lesions after UV (in genomic DNA EIIISS constitute about 10% of total lesions, whereas CPDs are about 70% of total lesions). We have shown that excision of UV induced EIIISS is enhanced following a prior UV irradiation. No enhancement of repair was detected in either the rad7 delta or the rad16 delta mutant. The fact that RAD7 and RAD16 are not required for the repair of EIIISS per se yet are required for the enhanced excision of these lesions from MAT alpha and HML alpha suggests two possibilities. These genes have two roles in NER, namely in the repair of CPDs from nontranscribed sequences, and in enhancing NER itself regardless of whether these genes' products are required for the excision of the specific lesion being repaired. In the latter case, the induction of RAD7 and RAD16 may increase the turnover of complexes stalled in nontranscribed DNA so as to increase the availability of NER proteins for the repair of CPDs and EIIISS in all regions of the genome.

  18. Overexpressed of RAD51 suppresses recombination defects: a possible mechanism to reverse genomic instability

    Energy Technology Data Exchange (ETDEWEB)

    Schild, David; Wiese, Claudia

    2009-10-15

    RAD51, a key protein in the homologous recombinational DNA repair (HRR) pathway, is the major strand-transferase required for mitotic recombination. An important early step in HRR is the formation of single-stranded DNA (ss-DNA) coated by RPA (a ss-DNA binding protein). Displacement of RPA by RAD51 is highly regulated and facilitated by a number of different proteins known as the 'recombination mediators'. To assist these recombination mediators, a second group of proteins also is required and we are defining these proteins here as 'recombination co-mediators'. Defects in either recombination mediators or comediators, including BRCA1 and BRCA2, lead to impaired HRR that can genetically be complemented for (i.e. suppressed) by overexpression of RAD51. Defects in HRR have long been known to contribute to genomic instability leading to tumor development. Since genomic instability also slows cell growth, precancerous cells presumably require genomic restabilization to gain a growth advantage. RAD51 is overexpressed in many tumors, and therefore, we hypothesize that the complementing ability of elevated levels of RAD51 in tumors with initial HRR defects limits genomic instability during carcinogenic progression. Of particular interest, this model may also help explain the high frequency of TP53 mutations in human cancers, since wild-type p53 represses RAD51.

  19. Bloom syndrome helicase stimulates RAD51 DNA strand exchange activity through a novel mechanism.

    Science.gov (United States)

    Bugreev, Dmitry V; Mazina, Olga M; Mazin, Alexander V

    2009-09-25

    Loss or inactivation of BLM, a helicase of the RecQ family, causes Bloom syndrome, a genetic disorder with a strong predisposition to cancer. Although the precise function of BLM remains unknown, genetic data has implicated BLM in the process of genetic recombination and DNA repair. Previously, we demonstrated that BLM can disrupt the RAD51-single-stranded DNA filament that promotes the initial steps of homologous recombination. However, this disruption occurs only if RAD51 is present in an inactive ADP-bound form. Here, we investigate interactions of BLM with the active ATP-bound form of the RAD51-single-stranded DNA filament. Surprisingly, we found that BLM stimulates DNA strand exchange activity of RAD51. In contrast to the helicase activity of BLM, this stimulation does not require ATP hydrolysis. These data suggest a novel BLM function that is stimulation of the RAD51 DNA pairing. Our results demonstrate the important role of the RAD51 nucleoprotein filament conformation in stimulation of DNA pairing by BLM.

  20. BI-RADS CATEGORIZATION AND POSITIVE PREDICTIVE VALUE OF MAMMOGRAPHIC FEATURES

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To determine whether the categories defined in the Breast Imaging Reporting and Data System (BI-RADS) are useful predictors of malignancy. Methods: A total of 348 cases with benign and malignant breast diseases were collected. Mammographic and pathologic findings were reviewed. Mammograms of 348 cases were characterized according to BI-RADS descriptors and were categorized by the final assessment categories. Results: Of the all 348 patients, 232 (67%) were carcinomas. Significantly more masses with calcification and speculation were found in breast cancers than in benign breast diseases. BI-RADS final assessment categories were category 2 and 3 in 106 cases, in which 75% (79/106) were benign; category 4 and 5 in 242 cases, in which 85% (205/242) were carcinomas. BI-RADS categories 4 and 5 are useful predictors of relative likelihood of malignancy. The features with higher positive predictive values for carcinomas were irregular shape, indistinct or speculated margins, fine or linear calcification morphology, and regional calcification distribution. Conclusion: BI-RADS lexicon is successful in providing a standardized language for physicians to describe lesion morphology. BI-RADS category is useful for predicting the presence of malignancy.

  1. Overexpression of Rad in muscle worsens diet-induced insulin resistance and glucose intolerance and lowers plasma triglyceride level

    Science.gov (United States)

    Ilany, Jacob; Bilan, Philip J.; Kapur, Sonia; Caldwell, James S.; Patti, Mary-Elizabeth; Marette, Andre; Kahn, C. Ronald

    2006-03-01

    Rad is a low molecular weight GTPase that is overexpressed in skeletal muscle of some patients with type 2 diabetes mellitus and/or obesity. Overexpression of Rad in adipocytes and muscle cells in culture results in diminished insulin-stimulated glucose uptake. To further elucidate the potential role of Rad in vivo, we have generated transgenic (tg) mice that overexpress Rad in muscle using the muscle creatine kinase (MCK) promoter-enhancer. Rad tg mice have a 6- to 12-fold increase in Rad expression in muscle as compared to wild-type littermates. Rad tg mice grow normally and have normal glucose tolerance and insulin sensitivity, but have reduced plasma triglyceride levels. On a high-fat diet, Rad tg mice develop more severe glucose intolerance than the wild-type mice; this is due to increased insulin resistance in muscle, as exemplified by a rightward shift in the dose-response curve for insulin stimulated 2-deoxyglucose uptake. There is also a unexpected further reduction of the plasma triglyceride levels that is associated with increased levels of lipoprotein lipase in the Rad tg mice. These results demonstrate a potential synergistic interaction between increased expression of Rad and high-fat diet in creation of insulin resistance and altered lipid metabolism present in type 2 diabetes. diabetes mellitus | glucose transport | RGK GTPase | transgenic mouse

  2. High-pressure high-temperature stability of hcp-IrxOs1-x (x = 0.50 and 0.55) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Yusenko, Kirill V.; Bykova, Elena; Bykov, Maxim; Gromilov, Sergey A.; Kurnosov, Alexander V.; Prescher, Clemens; Prakapenka, Vitali B.; Crichton, Wilson A.; Hanfland, Michael; Margadonna, Serena; Dubrovinsky, Leonid S.

    2016-12-23

    Hcp-Ir0.55Os0.45 and hcp-Ir0.50Os0.50 alloys were synthesised by thermal decomposition of single-source precursors in hydrogen atmosphere. Both alloys correspond to a miscibility gap in the Ir–Os binary phase diagram and therefore are metastable at ambient conditions. An in situ powder X-ray diffraction has been used for a monitoring a formation of hcp-Ir0.55Os0.45 alloy from (NH4)2[Ir0.55Os0.45Cl6] precursor. A crystalline intermediate compound and nanodimentional metallic particles with a large concentration of defects has been found as key intermediates in the thermal decomposition process in hydrogen flow. High-temperature stability of titled hcp-structured alloys has been investigated upon compression up to 11 GPa using a multi-anvil press and up to 80 GPa using laser-heated diamond-anvil cells to obtain a phase separation into fcc + hcp mixture. Compressibility curves at room temperature as well as thermal expansion at ambient pressure and under compression up to 80 GPa were collected to obtain thermal expansion coefficients and bulk moduli. hcp-Ir0.55Os0.45 alloy shows bulk moduli B0 = 395 GPa. Thermal expansion coefficients were estimated as α = 1.6·10-5 K-1 at ambient pressure and α = 0.3·10-5 K-1 at 80 GPa. Obtained high-pressure high-temperature data allowed us to construct the first model for pressure-dependent Ir–Os phase diagram.

  3. Estudio dilatométrico de la descomposición anisotérmica de la perlita en un acero bajo en carbono (0,11 C-0,50 Mn

    Directory of Open Access Journals (Sweden)

    García de Andrés, C.

    1998-05-01

    Full Text Available A dilatometric contraction at the onset of the austenitization has been detected by means of high resolution dilatometric analysis. This anomaly was associated with the pearlite dissolution process. A significant effect of pearlite interlamellar spacing on the shape of the dilatometric anomaly has been found. A clear dilatometric anomaly can only be detected when a fine pearlite is present in the starting microstructure of the steel. The identification of the temperature at which pearlite dissolution finishes would make it possible to select the most suitable intercritical temperature to obtain ferrite + martensite dual phase microstructures with an optimum combination of mechanical properties. In the presente work, the influence of starting pearlite morphology on the dilatometric response associated with the pearlite dissolution process during continuous heating has been studied in 0.11C-0.50Mn low carbon steel.

    Por medio del análisis dilatométrico de alta resolución, se ha detectado la aparición de una contracción dilatométrica asociada con el proceso de disolución de la perlita, que únicamente aparece cuando la microestructura inicial presenta perlita con un espaciado interlaminar fino. Esta contracción dilatométrica desaparece cuando la estructura inicial presenta una perlita grosera o de mayor espaciado interlaminar, impidiendo así la selección de las temperaturas del intercrítico más apropiadas para la obtención de microestructuras dual de ferrita + martensita con las mejores propiedades mecánicas. En este trabajo se estudia la influencia de la morfología de la perlita inicial de un acero 0,11C-0,50Mn sobre la respuesta dilatométrica asociada al proceso de disolución de dicha fase en calentamiento continuo.

  4. The tumor suppressor homolog in fission yeast, myh1{sup +}, displays a strong interaction with the checkpoint gene rad1{sup +}

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Kristina; Warringer, Jonas; Farewell, Anne [Department of Cell and Molecular Biology, Lundberg Laboratory, Goeteborg University, P.O. Box 462, Goeteborg SE-405 30 (Sweden); Park, Han-Oh [Bioneer Corporation, 49-3, Munpyeong-dong, Daedeok-gu, Daejon 306-220 (Korea, Republic of); Hoe, Kwang-Lae; Kim, Dong-Uk [Functional Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yusong, Daejeon (Korea, Republic of); Hayles, Jacqueline [Cell Cycle Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln' s Inn Fields, London WC2A 3PX (United Kingdom); Sunnerhagen, Per [Department of Cell and Molecular Biology, Lundberg Laboratory, Goeteborg University, P.O. Box 462, Goeteborg SE-405 30 (Sweden)], E-mail: per.sunnerhagen@cmb.gu.se

    2008-09-26

    The DNA glycosylase MutY is strongly conserved in evolution, and homologs are found in most eukaryotes and prokaryotes examined. This protein is implicated in repair of oxidative DNA damage, in particular adenine mispaired opposite 7,8-dihydro-8-oxoguanine. Previous investigations in Escherichia coli, fission yeast, and mammalian cells show an association of mutations in MutY homologs with a mutator phenotype and carcinogenesis. Eukaryotic MutY homologs physically associate with several proteins with a role in replication, DNA repair, and checkpoint signaling, specifically the trimeric 9-1-1 complex. In a genetic investigation of the fission yeast MutY homolog, myh1{sup +}, we show that the myh1 mutation confers a moderately increased UV sensitivity alone and in combination with mutations in several DNA repair genes. The myh1 rad1, and to a lesser degree myh1 rad9, double mutants display a synthetic interaction resulting in enhanced sensitivity to DNA damaging agents and hydroxyurea. UV irradiation of myh1 rad1 double mutants results in severe chromosome segregation defects and visible DNA fragmentation, and a failure to activate the checkpoint. Additionally, myh1 rad1 double mutants exhibit morphological defects in the absence of DNA damaging agents. We also found a moderate suppression of the slow growth and UV sensitivity of rhp51 mutants by the myh1 mutation. Our results implicate fission yeast Myh1 in repair of a wider range of DNA damage than previously thought, and functionally link it to the checkpoint pathway.

  5. Automated annotation and classification of BI-RADS assessment from radiology reports.

    Science.gov (United States)

    Castro, Sergio M; Tseytlin, Eugene; Medvedeva, Olga; Mitchell, Kevin; Visweswaran, Shyam; Bekhuis, Tanja; Jacobson, Rebecca S

    2017-05-01

    The Breast Imaging Reporting and Data System (BI-RADS) was developed to reduce variation in the descriptions of findings. Manual analysis of breast radiology report data is challenging but is necessary for clinical and healthcare quality assurance activities. The objective of this study is to develop a natural language processing (NLP) system for automated BI-RADS categories extraction from breast radiology reports. We evaluated an existing rule-based NLP algorithm, and then we developed and evaluated our own method using a supervised machine learning approach. We divided the BI-RADS category extraction task into two specific tasks: (1) annotation of all BI-RADS category values within a report, (2) classification of the laterality of each BI-RADS category value. We used one algorithm for task 1 and evaluated three algorithms for task 2. Across all evaluations and model training, we used a total of 2159 radiology reports from 18 hospitals, from 2003 to 2015. Performance with the existing rule-based algorithm was not satisfactory. Conditional random fields showed a high performance for task 1 with an F-1 measure of 0.95. Rules from partial decision trees (PART) algorithm showed the best performance across classes for task 2 with a weighted F-1 measure of 0.91 for BIRADS 0-6, and 0.93 for BIRADS 3-5. Classification performance by class showed that performance improved for all classes from Naïve Bayes to Support Vector Machine (SVM), and also from SVM to PART. Our system is able to annotate and classify all BI-RADS mentions present in a single radiology report and can serve as the foundation for future studies that will leverage automated BI-RADS annotation, to provide feedback to radiologists as part of a learning health system loop. Copyright © 2017. Published by Elsevier Inc.

  6. Analysis of the tolerance to DNA alkylating damage in MEC1 and RAD53 checkpoint mutants of Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Alfonso Gallego-Sánchez

    Full Text Available Checkpoint response, tolerance and repair are three major pathways that eukaryotic cells evolved independently to maintain genome stability and integrity. Here, we studied the sensitivity to DNA damage in checkpoint-deficient budding yeast cells and found that checkpoint kinases Mec1 and Rad53 may modulate the balance between error-free and error-prone branches of the tolerance pathway. We have consistently observed that mutation of the RAD53 counterbalances error-free and error-prone branches upon exposure of cells to DNA damage induced either by MMS alkylation or by UV-radiation. We have also found that the potential Mec1/Rad53 balance modulation is independent from Rad6/Rad18-mediated PCNA ubiquitylation, as mec1Δ or rad53Δ mutants show no defects in the modification of the sliding clamp, therefore, we infer that it is likely exerted by acting on TLS polymerases and/or template switching targets.

  7. Range of motion and leg rotation affect EMG activation levels of the superficial quadriceps muscles during leg extension.

    Science.gov (United States)

    Signorile, Joseph F; Lew, Karen; Stoutenberg, Mark; Pluchino, Alessandra; Lewis, John E; Gao, Jinrun

    2014-06-30

    The leg extension (LE) is commonly used to strengthen the quadriceps muscles during training and rehabilitation. This study examined the effects of limb position (POS) and range of motion (ROM) on quadriceps electromyography (EMG) during 8 repetitions (REP) of LE. Twenty-four participants performed eight LE REP at their 8-repetition maximum with lower limbs medially rotated (TI), laterally rotated (TO), and neutral (NEU). Each REP EMG was averaged over the first, middle, and final 0.524 rad ROM. For vastus medialis oblique (VMO), a REP x ROM interaction was detected (p<0.02). The middle 0.524 rad produced significantly higher EMG than the initial 0.524 rad for REP 6-8 and the final 0.524 rad produced higher EMG than the initial 0.524 rad for REP 1, 2, 3, 4, 6, 8 (p<0.05). For rectus femoris (RF), EMG activity increased across REP with TO generating the greatest activity (p<0.001). For vastus lateralis (VL), EMG increased across REP (p<0.001) with NEU and TO EMG increasing linearly throughout ROM, and TI activity greatest during the middle 0.524 rad. We conclude that to target the VMO the optimal ROM is the final 1.047 rad regardless of POS, while maximum EMG for the RF is generated using TO regardless of ROM. In contrast, the VL is maximally activated using TI over the first 1.047 rad ROM or in NEU over the final 0.524 rad ROM.

  8. Range of motion and leg rotation affect electromyography activation levels of the superficial quadriceps muscles during leg extension.

    Science.gov (United States)

    Signorile, Joseph F; Lew, Karen M; Stoutenberg, Mark; Pluchino, Alessandra; Lewis, John E; Gao, Jinrun

    2014-09-01

    Leg extension (LE) is commonly used to strengthen the quadriceps muscles during training and rehabilitation. This study examined the effects of limb position (POS) and range of motion (ROM) on quadriceps electromyography (EMG) during 8 repetitions (REP) of LE. Twenty-four participants performed 8 LE REP at their 8 repetition maximum with lower limbs medially rotated (TI), laterally rotated (TO), and neutral (NEU). Each REP EMG was averaged over the first, middle, and final 0.524 rad ROM. For vastus medialis oblique (VMO), a REP × ROM interaction was detected (p < 0.02). The middle 0.524 rad produced significantly higher EMG than the initial 0.524 rad for REP 6-8 and the final 0.524 rad produced higher EMG than the initial 0.524 rad for REP 1, 2, 3, 4, 6, and 8 (p ≤ 0.05). For rectus femoris (RF), EMG activity increased across REP with TO generating the greatest activity (p < 0.001). For vastus lateralis (VL), EMG increased across REP (p < 0.001) with NEU and TO EMG increasing linearly throughout ROM and TI activity greatest during the middle 0.524 rad. We conclude that to target the VMO, the optimal ROM is the final 1.047 rad regardless of POS, while maximum EMG for the RF is generated using TO regardless of ROM. In contrast, the VL is maximally activated using TI over the first 1.047 rad ROM or in NEU over the final 0.524 rad ROM.

  9. Real-time solution measurement of RAD51- and RecA-mediated strand assimilation without background annealing

    OpenAIRE

    Budke, Brian; Chan, Yuen-Ling; Bishop, Douglas K.; Connell, Philip P.

    2013-01-01

    RAD51 is the central strand exchange recombinase in somatic homologous recombination, providing genomic stability and promoting resistance to DNA damage. An important tool for mechanistic studies of RAD51 is the D-loop or strand assimilation assay, which measures the ability of RAD51-coated single-stranded DNA (ssDNA) to search for, invade and exchange ssDNA strands with a homologous duplex DNA target. As cancer cells generally overexpress RAD51, the D-loop assay has also emerged as an import...

  10. Transcriptional profile of the homologous recombination machinery and characterization of the EhRAD51 recombinase in response to DNA damage in Entamoeba histolytica

    Directory of Open Access Journals (Sweden)

    López-Camarillo César

    2008-04-01

    Full Text Available Abstract Background In eukaryotic and prokaryotic cells, homologous recombination is an accurate mechanism to generate genetic diversity, and it is also used to repair DNA double strand-breaks. RAD52 epistasis group genes involved in recombinational DNA repair, including mre11, rad50, nsb1/xrs2, rad51, rad51c/rad57, rad51b/rad55, rad51d, xrcc2, xrcc3, rad52, rad54, rad54b/rdh54 and rad59 genes, have been studied in human and yeast cells. Notably, the RAD51 recombinase catalyses strand transfer between a broken DNA and its undamaged homologous strand, to allow damaged region repair. In protozoan parasites, homologous recombination generating antigenic variation and genomic rearrangements is responsible for virulence variation and drug resistance. However, in Entamoeba histolytica the protozoan parasite responsible for human amoebiasis, DNA repair and homologous recombination mechanisms are still unknown. Results In this paper, we initiated the study of the mechanism for DNA repair by homologous recombination in the primitive eukaryote E. histolytica using UV-C (150 J/m2 irradiated trophozoites. DNA double strand-breaks were evidenced in irradiated cells by TUNEL and comet assays and evaluation of the EhH2AX histone phosphorylation status. In E. histolytica genome, we identified genes homologous to yeast and human RAD52 epistasis group genes involved in DNA double strand-breaks repair by homologous recombination. Interestingly, the E. histolytica RAD52 epistasis group related genes were differentially expressed before and after UV-C treatment. Next, we focused on the characterization of the putative recombinase EhRAD51, which conserves the typical architecture of RECA/RAD51 proteins. Specific antibodies immunodetected EhRAD51 protein in both nuclear and cytoplasmic compartments. Moreover, after DNA damage, EhRAD51 was located as typical nuclear foci-like structures in E. histolytica trophozoites. Purified recombinant EhRAD51 exhibited DNA binding

  11. Mars science laboratory radiation assessment detector (MSL/RAD) modeling workshop proceedings

    Science.gov (United States)

    Hassler, Donald M.; Norbury, John W.; Reitz, Günther

    2017-08-01

    The Radiation Assessment Detector (RAD) (Hassler et al., 2012; Zeitlin et al., 2016) onboard the Mars Science Laboratory (MSL) Curiosity rover (Grotzinger et al., 2012) is a sophisticated charged and neutral particle radiation analyzer developed by an international team of scientists and engineers from Southwest Research Institute in Boulder, Colorado as the leading institution, the University of Kiel and the German Aerospace Center in Cologne, Germany. RAD is a compact, powerful instrument capable of distinguishing between ionizing particles and neutral particles and providing neutron, gamma, and charged particle spectra from protons to iron as well as absorbed dose measurements in tissue-equivalent material. During the 6 month cruise to Mars, inside the MSL spacecraft, RAD served as a proxy to validate models of the radiation levels expected inside a spacecraft that future astronauts might experience (Zeitlin et al., 2013). RAD was turned on one day after the landing on August 7, 2012, exactly 100 years to the day after the discovery of cosmic rays on Earth by Victor Hess. These measurements are the first of their kind on the surface of another planet (Hassler et al., 2014), and the radiation data collected by RAD on the surface of Mars will inform projections of crew health risks and the design of protective surface habitats and other countermeasures for future human missions in the coming decades.

  12. Resolving RAD51C function in late stages of homologous recombination

    Directory of Open Access Journals (Sweden)

    Kuznetsov Sergey G

    2007-06-01

    Full Text Available Abstract DNA double strand breaks are efficiently repaired by homologous recombination. One of the last steps of this process is resolution of Holliday junctions that are formed at the sites of genetic exchange between homologous DNA. Although various resolvases with Holliday junctions processing activity have been identified in bacteriophages, bacteria and archaebacteria, eukaryotic resolvases have been elusive. Recent biochemical evidence has revealed that RAD51C and XRCC3, members of the RAD51-like protein family, are involved in Holliday junction resolution in mammalian cells. However, purified recombinant RAD51C and XRCC3 proteins have not shown any Holliday junction resolution activity. In addition, these proteins did not reveal the presence of a nuclease domain, which raises doubts about their ability to function as a resolvase. Furthermore, oocytes from infertile Rad51C mutant mice exhibit precocious separation of sister chromatids at metaphase II, a phenotype that reflects a defect in sister chromatid cohesion, not a lack of Holliday junction resolution. Here we discuss a model to explain how a Holliday junction resolution defect can lead to sister chromatid separation in mouse oocytes. We also describe other recent in vitro and in vivo evidence supporting a late role for RAD51C in homologous recombination in mammalian cells, which is likely to be resolution of the Holliday junction.

  13. The RecA/RAD51 protein drives migration of Holliday junctions via polymerization on DNA.

    Science.gov (United States)

    Rossi, Matthew J; Mazina, Olga M; Bugreev, Dmitry V; Mazin, Alexander V

    2011-04-19

    The Holliday junction (HJ), a cross-shaped structure that physically links the two DNA helices, is a key intermediate in homologous recombination, DNA repair, and replication. Several helicase-like proteins are known to bind HJs and promote their branch migration (BM) by translocating along DNA at the expense of ATP hydrolysis. Surprisingly, the bacterial recombinase protein RecA and its eukaryotic homologue Rad51 also promote BM of HJs despite the fact they do not bind HJs preferentially and do not translocate along DNA. RecA/Rad51 plays a key role in DNA double-stranded break repair and homologous recombination. RecA/Rad51 binds to ssDNA and forms contiguous filaments that promote the search for homologous DNA sequences and DNA strand exchange. The mechanism of BM promoted by RecA/RAD51 is unknown. Here, we demonstrate that cycles of RecA/Rad51 polymerization and dissociation coupled with ATP hydrolysis drives the BM of HJs.

  14. Monitoring the Heliospheric Conditions at Mars Using MSL/RAD Measurements

    Science.gov (United States)

    Guo, J.; Wimmer-Schweingruber, R. F.; Zeitlin, C. J.; Rafkin, S. C.; Hassler, D.; Posner, A.

    2015-12-01

    The Radiation Assessment Detector (RAD), on board Mars Science Laboratory's (MSL) rover Curiosity, measures the radiation dose rate as well as the energy spectra of energetic charged and neutral particles at the surface of Mars. With these first-ever measurements of GCR fluxes on the Martian surface, RAD can be used as a monitor for heliospheric modulation at Mars location, similar to neutron monitors at Earth. We do this by first correlating the GCR dose rate measurements at Mars and solar modulations at Earth when there is a good magnetic connection between the two planets. With the thus obtained correlation we obtain an empirical function for the dependence of the modulation parameter at Mars on RAD dose rate. This function can in turn help to calibrate the heliospheric modulation at Mars throughout the MSL/RAD mission period. The resulting solar modulation at Mars and at Earth over three years (>1000 sols) is then compared. In order to verify our 'prediction' method, we use the local modulation parameter at Mars as an input for Badhwar O'Neil model providing the primary spectra for PLANETOCOSMIC simulations which eventually model the surface particle spectra that can be compared with RAD measurements of the spectra.

  15. Rad6 upregulation promotes stem cell-like characteristics and platinum resistance in ovarian cancer

    Science.gov (United States)

    Somasagara, Ranganatha R.; Tripathi, Kaushlendra; Spencer, Sebastian M.; Clark, David W.; Barnett, Reagan; Bachaboina, Lavanya; Scalici, Jennifer; Rocconi, Rodney P.; Piazza, Gary A.; Palle, Komaraiah

    2015-01-01

    Ovarian cancer is the fifth most deadly cancer in women in the United States and despite advances in surgical and chemotherapeutic treatments survival rates have not significantly improved in decades. The poor prognosis for ovarian cancer patients is largely due to the extremely high (80%) recurrence rate of ovarian cancer and because the recurrent tumors are often resistant to the widely utilized platinum-based chemotherapeutic drugs. In this study, expression of Rad6, an E2 ubiquitin-conjugating enzyme, was found to strongly correlate with ovarian cancer progression. Furthermore, in ovarian cancer cells Rad6 was found to stabilize β-catenin promoting stem cell-related characteristics, including expression of stem cell markers and anchorage-independent growth. Cancer stem cells can promote chemoresistance, tumor recurrence and metastasis, all of which are limiting factors in treating ovarian cancer. Thus it is significant that Rad6 overexpression led to increased resistance to the chemotherapeutic drug carboplatin and correlated with tumor cell invasion. These findings show the importance of Rad6 in ovarian cancer and emphasize the need for further studies of Rad6 as a potential target for the treatment of ovarian cancer. PMID:26679603

  16. RadBall{sup TM} Technology Testing and MCNP Modeling of the Tungsten Collimator

    Energy Technology Data Exchange (ETDEWEB)

    Farfan, Eduardo B; Foley, Trevor Q; Coleman, J Rusty; Jannik, G Timothy; Holmes, Christopher J; Oldham, Mark; Adamovics, John; Stanley, Steven J, E-mail: Eduardo.Farfan@srnl.doe.go

    2010-11-01

    The UK's National Nuclear Laboratory (NNL) has developed a remote, non-electrical, radiation-mapping device known as RadBall{sup TM}, which can locate and quantify radioactive hazards within contaminated areas of the nuclear industry. RadBall{sup TM} consists of a colander-like outer shell that houses a radiation-sensitive polymer sphere. The outer shell works to collimate radiation sources and those areas of the polymer sphere that are exposed react, becoming increasingly more opaque, in proportion to the absorbed dose. The polymer sphere is imaged in an optical-CT scanner, which produces a high resolution 3D map of optical attenuation coefficients. Subsequent analysis of the optical attenuation matrix provides information on the spatial distribution of sources in a given area forming a 3D characterization of the area of interest. RadBall{sup TM} has no power requirements and can be positioned in tight or hard-to reach locations. The RadBall{sup TM} technology has been deployed in a number of technology trials in nuclear waste reprocessing plants at Sellafield in the UK and facilities of the Savannah River National Laboratory (SRNL). This study focuses on the RadBall{sup TM} testing and modeling accomplished at SRNL.

  17. RAD21 cooperates with pluripotency transcription factors in the maintenance of embryonic stem cell identity.

    Directory of Open Access Journals (Sweden)

    Anja Nitzsche

    Full Text Available For self-renewal, embryonic stem cells (ESCs require the expression of specific transcription factors accompanied by a particular chromosome organization to maintain a balance between pluripotency and the capacity for rapid differentiation. However, how transcriptional regulation is linked to chromosome organization in ESCs is not well understood. Here we show that the cohesin component RAD21 exhibits a functional role in maintaining ESC identity through association with the pluripotency transcriptional network. ChIP-seq analyses of RAD21 reveal an ESC specific cohesin binding pattern that is characterized by CTCF independent co-localization of cohesin with pluripotency related transcription factors Oct4, Nanog, Sox2, Esrrb and Klf4. Upon ESC differentiation, most of these binding sites disappear and instead new CTCF independent RAD21 binding sites emerge, which are enriched for binding sites of transcription factors implicated in early differentiation. Furthermore, knock-down of RAD21 causes expression changes that are similar to expression changes after Nanog depletion, demonstrating the functional relevance of the RAD21--pluripotency transcriptional network association. Finally, we show that Nanog physically interacts with the cohesin or cohesin interacting proteins STAG1 and WAPL further substantiating this association. Based on these findings we propose that a dynamic placement of cohesin by pluripotency transcription factors contributes to a chromosome organization supporting the ESC expression program.

  18. RadNotes: a novel software development tool for radiology education.

    Science.gov (United States)

    Baxter, A B; Klein, J S; Oesterle, E V

    1997-01-01

    RadNotes is a novel software development tool that enables physicians to develop teaching materials incorporating text and images in an intelligent, highly usable format. Projects undertaken in the RadNotes environment require neither programming expertise nor the assistance of a software engineer. The first of these projects, Thoracic Imaging, integrates image teaching files, concise disease and topic summaries, references, and flash card quizzes into a single program designed to provide an overview of chest radiology. RadNotes is intended to support the academic goals of teaching radiologists by enabling authors to create, edit, and electronically distribute image-oriented presentations. RadNotes also supports the educational goals of physicians who wish to quickly review selected imaging topics, as well as to develop a visual vocabulary of corresponding radiologic anatomy and pathologic conditions. Although Thoracic Imaging was developed with the aim of introducing chest radiology to residents, RadNotes can be used to develop tutorials and image-based tests for all levels; create corresponding World Wide Web sites; and organize notes, images, and references for individual use.

  19. The Effects of a High Magnetic Field on the Annealing of [(Fe0.5Co0.50.75B0.2Si0.05]96Nb4 Bulk Metallic Glass

    Directory of Open Access Journals (Sweden)

    Peng Jia

    2016-11-01

    Full Text Available In contrast with amorphous alloys, nanocrystalline soft magnetic materials show improved thermal stability and higher soft magnetic properties. The nanocrystalline soft magnetic composites are usually fabricated by partially crystallizing from parent amorphous alloys. This paper reports our experimental observation on the sequence of crystallization in metallic glass under a high magnetic field (HMF. An application of a HMF to bulk metallic glass (BMG of [(Fe0.5Co0.50.75B0.2Si0.05]96Nb4 prioritizes the precipitation of α-(Fe,Co phase separated from the subsequent precipitation of borides, (Fe,Co23B6, upon isothermal annealing at a glass transition temperature. Furthermore, it was observed that, through the annealing treatment under a HMF, a soft magnetic nanocomposite, in which only α-(Fe,Co phase uniformly distributes in amorphous matrix, was achieved for boron-bearing BMG. The promotion of the α-Fe or (Fe,Co phase and the prevention of the boride phases during the isothermal annealing process help to produce high-quality soft magnetic nanocomposite materials. The mechanism by which a HMF influences the crystallization sequence was interpreted via certain changes in Gibbs free energies for two ferromagnetic phases. This finding evidences that the annealing treatment under a HMF is suitable for enhancing the soft magnetic properties of high B content (Fe,Co-based bulk amorphous and nanocrystalline materials.

  20. Magnetism and transport studies in off-stoichiometric metallic perovskite compounds GdPd{sub 3}B{sub x} (x=0.25, 0.50 and 0.75)

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Abhishek, E-mail: abhishek.phy@gmail.co [S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700098 (India); Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India); Mazumdar, Chandan, E-mail: chandan.mazumdar@saha.ac.i [Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India); Ranganathan, R. [Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)

    2010-12-15

    We report the magnetic and transport properties of the off-stoichiometric metallic perovskite like compounds GdPd{sub 3}B{sub x} (x=0.25, 0.50 and 0.75). Our results show that doping with boron in the lattice of parent binary-compound GdPd{sub 3} leads to lattice expansion. Which in turn manifests in contrasting magnetic and transport behaviors of the doped compounds in comparison with the undoped GdPd{sub 3}. An attempt has been made to compare and correlate the results of magnetic and transport measurements of GdPd{sub 3}B{sub x} with that of stoichiometric compositions GdPd{sub 3}B{sub x}C{sub 1-x}. The comparative study of GdPd{sub 3}B{sub x} and GdPd{sub 3}B{sub x}C{sub 1-x} confirms that there is a strong correlations between the structural, magnetic and transport properties of these compounds.

  1. Automated detection of ambiguity in BI-RADS assessment categories in mammography reports.

    Science.gov (United States)

    Bozkurt, Selen; Rubin, Daniel

    2014-01-01

    An unsolved challenge in biomedical natural language processing (NLP) is detecting ambiguities in the reports that can help physicians to improve report clarity. Our goal was to develop NLP methods to tackle the challenges of identifying ambiguous descriptions of the laterality of BI-RADS Final Assessment Categories in mammography radiology reports. We developed a text processing system that uses a BI-RADS ontology we built as a knowledge source for automatic annotation of the entities in mammography reports relevant to this problem. We used the GATE NLP toolkit and developed customized processing resources for report segmentation, named entity recognition, and detection of mismatches between BI-RADS Final Assessment Categories and mammogram laterality. Our system detected 55 mismatched cases in 190 reports and the accuracy rate was 81%. We conclude that such NLP techniques can detect ambiguities in mammography reports and may reduce discrepancy and variability in reporting.

  2. Purification and characterization of Rad3 ATPase/DNA helicase from Saccharomyces cerevisiae.

    Science.gov (United States)

    Harosh, I; Naumovski, L; Friedberg, E C

    1989-12-05

    The Rad3 ATPase/DNA helicase was purified to physical homogeneity from extracts of yeast cells containing overexpressed Rad3 protein. The DNA helicase can unwind duplex regions as short as 11 base pairs in a partially duplex circular DNA substrate and does so by a strictly processive mechanism. On partially duplex linear substrates, the enzyme has a strict 5'----3' polarity with respect to the single strand to which it binds. Nicked circular DNA is not utilized as a substrate, and the enzyme requires single-stranded gaps between 5 and 21 nucleotides long to unwind oligonucleotide fragments from partially duplex linear molecules. The enzyme also requires duplex regions at least 11 base pairs long when these are present at the ends of linear molecules. Rad3 DNA helicase activity is inhibited by the presence of ultraviolet-induced photoproducts in duplex regions of partially duplex circular molecules.

  3. Colocalization of multiple DNA double-strand breaks at a single Rad52 repair centre

    DEFF Research Database (Denmark)

    Lisby, M.; Mortensen, Uffe Hasbro; Rothstein, R.

    2003-01-01

    DNA double-strand break repair (DSBR) is an essential process for preserving genomic integrity in all organisms. To investigate this process at the cellular level, we engineered a system of fluorescently marked DNA double-strand breaks (DSBs) in the yeast Saccharomyces cerevisiae to visualize...... in vivo DSBR in single cells. Using this system, we demonstrate for the first time that Rad52 DNA repair foci and DSBs colocalize. Time-lapse microscopy reveals that the relocalization of Rad52 protein into a focal assembly is a rapid and reversible process. In addition, analysis of DNA damage checkpoint......-deficient cells provides direct evidence for coordination between DNA repair and subsequent release from checkpoint arrest. Finally, analyses of cells experiencing multiple DSBs demonstrate that Rad52 foci are centres of DNA repair capable of simultaneously recruiting more than one DSB....

  4. Initial experience with optical-CT scanning of RadBall Dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Oldham, M; Clift, C; Thomas, A; Farfan, E; Foley, T; Jannik, T; Adamovics, J; Holmes, C; Stanley, S, E-mail: Mark.Oldham@Duke.ed

    2010-11-01

    The RadBall dosimeter is a novel device for providing 3-D information on the magnitude and distribution of contaminant sources of unknown radiation in a given hot cell, glovebox, or contaminated room. The device is presently under evaluation by the National Nuclear Lab (NNL, UK) and the Savannah River National Laboratory (SRNL, US), for application as a diagnostic device for such unknown contaminants in the nuclear industry. A critical component of the technique is imaging the dose distribution recorded in the RadBall using optical-CT scanning. Here we present our initial investigations using the Duke Mid-sized Optical-CT Scanner (DMOS) to image dose distributions deposited in RadBalls exposed to a variety of radiation treatments.

  5. Diagnostic value of breast ultrasound in mammography BI-RADS 0 and clinically indeterminate or suspicious of malignancy breast lesions

    Directory of Open Access Journals (Sweden)

    Dobrosavljević Aleksandar

    2016-01-01

    Full Text Available Background/Aim. Not only that ultrasound makes the difference between cystic and solid changes in breast tissue, as it was the case at the beginning of its use, but it also makes the differential diagnosis in terms of benign-malignant. The aim of this study was to assess the role of sonography in the diagnosis of palpable breast masses according to the American College of Radiology Ultrasonographic Breast Imaging Reporting and Data System (BI-RADS and to correlate the BI-RADS 4 and BI-RADS 5 category with pathohistological findings. Methods. A retrospective study was conducted with the breast sonograms of 30 women presented with palpable breast masses found to be mammography category BI-RADS 0 and ultrasonographic BI-RADS categories 4 and 5. The sonographic categories were correlated with pathohistological findings. Results. Surgical biopsy in 30 masses revealed: malignancy (56.7%, fibroadenoma (26.7%, fibrocystic dysplasia with/without atypia (10%, lipoma (3.3% and intramammary lymph node (3.3%. Correlation between BI-RADS categories and pathohistological findings was found (p < 0.05. All BI-RADS 5 masses were malignant, while in BI-RADS 4A category fibroadenomas dominated. A total of 53.8% of all benign lesions were found in women 49 years of age or younger as compared with 35.3% of all malignancies in this group (p < 0.05. Conclusion. Ultrasonography BI-RADS improved classification of breast masses. The ultrasound BI-RADS 4 (A, B, C and BI-RADS 5 lesions should be worked-up with biopsy.

  6. Enhancing survival of mouse oocytes following chemotherapy or aging by targeting Bax and Rad51.

    Directory of Open Access Journals (Sweden)

    Loro L Kujjo

    Full Text Available BACKGROUND: Therapeutic approaches to preserve fertility in females undergoing cancer treatments are currently ineffective. This is partly due to limited knowledge of the molecular mechanisms that injured germ cells elicit to repair damage and survive or to abort repair and activate biochemical pathways leading to death. So far, we know that following spontaneously occurring or drug-induced DNA damage, the efficiency of DNA repair is a critical determinant of the cell's fate. The protein encoded by the Rad51 gene is one of several components recruited for homologous recombination-dependent DNA double-strand break repair in both somatic cells and germ cells. Recently, we showed that microinjection of recombinant Rad51 into AKR/J mouse oocytes decreased the extent of spontaneous DNA double-strand breaks, suppressed apoptosis, and restored the developmental competence in AKR/J embryos. Herein we characterized the nature of chemotherapy-induced lesions in oocytes, and the associated individual components of the DNA damage sensor and repair apparatus. For comparison, we also assessed parallel spontaneous changes in aging oocytes. METHODS: Data collected were derived from: analysis of apoptosis; immunodepletion; oocyte microinjections; immunocytochemistry; immunofluorescence; and CHIP-like assays. RESULTS: Our data show that: (i DNA damage in oocytes can be induced by both chemotherapy and spontaneously by the aging process; (ii oocytes possess the machinery and capability for repairing such DNA damage; (iii Rad51 is a critical player in the repair of both chemotherapy-induced and spontaneously-sustained DNA damage; and (iv in response to damage, oocytes exhibit an inverse functional relationship between presence of Bax and activity of Rad51. CONCLUSION/SIGNIFICANCE: Our results establish Rad51 and/or Bax as potential candidates that can be targeted for development of individualized chemotherapeutic interventions that are effective, but minimal in

  7. Rad59-facilitated acquisition of Y' elements by short telomeres delays the onset of senescence.

    Directory of Open Access Journals (Sweden)

    Dmitri Churikov

    2014-11-01

    Full Text Available Telomerase-negative yeasts survive via one of the two Rad52-dependent recombination pathways, which have distinct genetic requirements. Although the telomere pattern of type I and type II survivors is well characterized, the mechanistic details of short telomere rearrangement into highly evolved pattern observed in survivors are still missing. Here, we analyze immediate events taking place at the abruptly shortened VII-L and native telomeres. We show that short telomeres engage in pairing with internal Rap1-bound TG1-3-like tracts present between subtelomeric X and Y' elements, which is followed by BIR-mediated non-reciprocal translocation of Y' element and terminal TG1-3 repeats from the donor end onto the shortened telomere. We found that choice of the Y' donor was not random, since both engineered telomere VII-L and native VI-R acquired Y' elements from partially overlapping sets of specific chromosome ends. Although short telomere repair was associated with transient delay in cell divisions, Y' translocation on native telomeres did not require Mec1-dependent checkpoint. Furthermore, the homeologous pairing between the terminal TG1-3 repeats at VII-L and internal repeats on other chromosome ends was largely independent of Rad51, but instead it was facilitated by Rad59 that stimulates Rad52 strand annealing activity. Therefore, Y' translocation events taking place during presenescence are genetically separable from Rad51-dependent Y' amplification process that occurs later during type I survivor formation. We show that Rad59-facilitated Y' translocations on X-only telomeres delay the onset of senescence while preparing ground for type I survivor formation.

  8. Mouse RAD54 Affects DNA Double-Strand Break Repair and Sister Chromatid Exchange

    Science.gov (United States)

    Dronkert, Mies L. G.; Beverloo, H. Berna; Johnson, Roger D.; Hoeijmakers, Jan H. J.; Jasin, Maria; Kanaar, Roland

    2000-01-01

    Cells can achieve error-free repair of DNA double-strand breaks (DSBs) by homologous recombination through gene conversion with or without crossover. In contrast, an alternative homology-dependent DSB repair pathway, single-strand annealing (SSA), results in deletions. In this study, we analyzed the effect of mRAD54, a gene involved in homologous recombination, on the repair of a site-specific I-SceI-induced DSB located in a repeated DNA sequence in the genome of mouse embryonic stem cells. We used six isogenic cell lines differing solely in the orientation of the repeats. The combination of the three recombination-test substrates used discriminated among SSA, intrachromatid gene conversion, and sister chromatid gene conversion. DSB repair was most efficient for the substrate that allowed recovery of SSA events. Gene conversion with crossover, indistinguishable from long tract gene conversion, preferentially involved the sister chromatid rather than the repeat on the same chromatid. Comparing DSB repair in mRAD54 wild-type and knockout cells revealed direct evidence for a role of mRAD54 in DSB repair. The substrate measuring SSA showed an increased efficiency of DSB repair in the absence of mRAD54. The substrate measuring sister chromatid gene conversion showed a decrease in gene conversion with and without crossover. Consistent with this observation, DNA damage-induced sister chromatid exchange was reduced in mRAD54-deficient cells. Our results suggest that mRAD54 promotes gene conversion with predominant use of the sister chromatid as the repair template at the expense of error-prone SSA. PMID:10757799

  9. Upgrades of the RadMon V6 and its Integration on a Nanosatellite for the Analysis and the Comparative Study of the CHARM and Low Earth Orbit Environments

    CERN Document Server

    AUTHOR|(CDS)2080738; PERONNARD Paul, CERN

    Radiation fields in the CERN accelerator complex are characterized by mixed particles with broad energy ranges. A Radiation Monitoring System, called "RadMon", was developed for the distributed, on-line measurement of the complex radiation fields and their effect on the electronics installed in areas with a harsh radiation environment. The most recent version of the RadMon revealed a critical issue soon after deployment in the tunnel and the experimental areas. Multiple Cell Upsets (MCUs) arising from microlatchup events started showing up on the SRAM-based particle flux sensors equipped by the system, ultimately affecting the measurement and resulting in corrupted data and accuracy losses. A study of the generation of this effect was performed, and a solution using an on-line detection and correction algorithm embedded on an FPGA, was evaluated and implemented on the RadMon device. Furthermore, in the framework of the project CELESTA, a feasibility study was carried out to validate the adaptation of the RadM...

  10. RadShield: semiautomated shielding design using a floor plan driven graphical user interface.

    Science.gov (United States)

    DeLorenzo, Matthew C; Wu, Dee H; Yang, Kai; Rutel, Isaac B

    2016-09-01

    The purpose of this study was to introduce and describe the development of RadShield, a Java-based graphical user interface (GUI), which provides a base design that uniquely performs thorough, spatially distributed calculations at many points and reports the maximum air-kerma rate and barrier thickness for each barrier pursuant to NCRP Report 147 methodology. Semiautomated shielding design calculations are validated by two approaches: a geometry-based approach and a manual approach. A series of geometry-based equations were derived giving the maximum air-kerma rate magnitude and location through a first derivative root finding approach. The second approach consisted of comparing RadShield results with those found by manual shielding design by an American Board of Radiology (ABR)-certified medical physicist for two clinical room situations: two adjacent catheterization labs, and a radiographic and fluoroscopic (R&F) exam room. RadShield's efficacy in finding the maximum air-kerma rate was compared against the geometry-based approach and the overall shielding recommendations by RadShield were compared against the medical physicist's shielding results. Percentage errors between the geometry-based approach and RadShield's approach in finding the magnitude and location of the maximum air-kerma rate was within 0.00124% and 14 mm. RadShield's barrier thickness calculations were found to be within 0.156 mm lead (Pb) and 0.150 mm lead (Pb) for the adjacent catheterization labs and R&F room examples, respectively. However, within the R&F room example, differences in locating the most sensitive calculation point on the floor plan for one of the barriers was not considered in the medical physicist's calculation and was revealed by the RadShield calculations. RadShield is shown to accurately find the maximum values of air-kerma rate and barrier thickness using NCRP Report 147 methodology. Visual inspection alone of the 2D X-ray exam distribution by a medical physicist may not

  11. SUMO modification regulates BLM and RAD51 interaction at damaged replication forks.

    Directory of Open Access Journals (Sweden)

    Karen J Ouyang

    2009-12-01

    Full Text Available The gene mutated in Bloom's syndrome, BLM, is important in the repair of damaged replication forks, and it has both pro- and anti-recombinogenic roles in homologous recombination (HR. At damaged forks, BLM interacts with RAD51 recombinase, the essential enzyme in HR that catalyzes homology-dependent strand invasion. We have previously shown that defects in BLM modification by the small ubiquitin-related modifier (SUMO cause increased gamma-H2AX foci. Because the increased gamma-H2AX could result from defective repair of spontaneous DNA damage, we hypothesized that SUMO modification regulates BLM's function in HR repair at damaged forks. To test this hypothesis, we treated cells that stably expressed a normal BLM (BLM+ or a SUMO-mutant BLM (SM-BLM with hydroxyurea (HU and examined the effects of stalled replication forks on RAD51 and its DNA repair functions. HU treatment generated excess gamma-H2AX in SM-BLM compared to BLM+ cells, consistent with a defect in replication-fork repair. SM-BLM cells accumulated increased numbers of DNA breaks and were hypersensitive to DNA damage. Importantly, HU treatment failed to induce sister-chromatid exchanges in SM-BLM cells compared to BLM+ cells, indicating a specific defect in HR repair and suggesting that RAD51 function could be compromised. Consistent with this hypothesis, RAD51 localization to HU-induced repair foci was impaired in SM-BLM cells. These data suggested that RAD51 might interact noncovalently with SUMO. We found that in vitro RAD51 interacts noncovalently with SUMO and that it interacts more efficiently with SUMO-modified BLM compared to unmodified BLM. These data suggest that SUMOylation controls the switch between BLM's pro- and anti-recombinogenic roles in HR. In the absence of BLM SUMOylation, BLM perturbs RAD51 localization at damaged replication forks and inhibits fork repair by HR. Conversely, BLM SUMOylation relieves its inhibitory effects on HR, and it promotes RAD51 function.

  12. 2015 RAD-AID Conference on International Radiology for Developing Countries: The Evolving Global Radiology Landscape.

    Science.gov (United States)

    Kesselman, Andrew; Soroosh, Garshasb; Mollura, Daniel J

    2016-09-01

    Radiology in low- and middle-income (developing) countries continues to make progress. Research and international outreach projects presented at the 2015 annual RAD-AID conference emphasize important global themes, including (1) recent slowing of emerging market growth that threatens to constrain the advance of radiology, (2) increasing global noncommunicable diseases (such as cancer and cardiovascular disease) needing radiology for detection and management, (3) strategic prioritization for pediatric radiology in global public health initiatives, (4) continuous expansion of global health curricula at radiology residencies and the RAD-AID Chapter Network's participating institutions, and (5) technologic innovation for recently accelerated implementation of PACS in low-resource countries. Published by Elsevier Inc.

  13. RadSTraM: Radiological Source Tracking and Monitoring, Phase II Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Tracy A [ORNL; Walker, Randy M [ORNL; Hill, David E [ORNL; Gross, Ian G [ORNL; Smith, Cyrus M [ORNL; Abercrombie, Robert K [ORNL

    2008-12-01

    This report focuses on the technical information gained from the Radiological Source Tracking and Monitoring (RadSTraM) Phase II investigation and its implications. The intent of the RadSTraM project was to determine the feasibility of tracking radioactive materials in commerce, particularly International Atomic Energy Agency (IAEA) Category 3 and 4 materials. Specifically, Phase II of the project addressed tracking radiological medical isotopes in commerce. These categories of materials are susceptible to loss or theft but the problem is not being addressed by other agencies.

  14. PI-RADS classification. Structured reporting for MRI of the prostate; PI-RADS-Klassifikation. Strukturiertes Befundungsschema fuer die MRT der Prostata

    Energy Technology Data Exchange (ETDEWEB)

    Roethke, Matthias; Schlemmer, H.P. [Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany). Abt. fuer Radiologie; Blondin, D. [Universitaetsklinikum Duesseldorf (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Franiel, T. [Charite - Universitaetsmedizin Berlin, Campus Mitte (Germany). Inst. fuer Radiologie

    2013-03-15

    Purpose: To flesh out the ESUR guidelines for the standardized interpretation of multiparametric magnetic resonance imaging (mMRI) for the detection of prostate cancer and to present a graphic reporting scheme for improved communication of findings to urologists. Materials and Methods: The ESUR has recently published a structured reporting system for mMRI of the prostate (PI-RADS). This system involves the use of 5-point Likert scales for grading the findings obtained with different MRI techniques. The mMRI includes T2-weighted MRI, diffusion-weighted imaging, dynamic contrast-enhanced MRI, and MR spectroscopy. In a first step, the fundamentals of technical implementation were determined by consensus, taking into account in particular the German-speaking community. Then, representative images were selected by consensus on the basis of examinations of the three institutions. In addition, scoring intervals for an aggregated PI-RADS score were determined in consensus. Results: The multiparametric methods were discussed critically with regard to implementation and the current status. Criteria used for grading mMRI findings with the PI-RADS classification were concretized by succinct examples. Using the consensus table for aggregated scoring in a clinical setting, a diagnosis of suspected prostate cancer should be made if the PI-RADS score is 4 or higher ({>=} 10 points if 3 techniques are used or {>=} 13 points if 4 techniques are used). Finally, a graphic scheme was developed for communicating mMRI prostate findings. Conclusion: Structured reporting according to the ESUR guidelines contributes to quality assurance by standardizing prostate mMRI, and it facilities the communication of findings to urologists. (orig.)

  15. Correlation of RAD51 and radiosensitization of methotrexate%氨甲蝶呤辐射增敏作用与RAD51的相关性研究

    Institute of Scientific and Technical Information of China (English)

    杜利清; 白剑强; 刘强; 王彦; 赵鹏; 陈凤华; 王宏; 樊飞跃

    2012-01-01

    Objective To evaluate the correlation between homologous recombination repair protein RAD51 and methotrexate-enhanced radiosensitivity.Methods Western blot and RT-PCR assays were used to detect RAD51 expression in HOS osteosarcoma cells exposed to γ-ray irradiation alone and in combination with methotrexate.Colony formation assay was used to test the survival fraction of HOS cells exposed to γ-rays and methotrexate.Results Methotrexate inhibited both protein and RNA expressions of RAD51,and the combination of radiation and methotrexate enhanced the inhibition of RAD51 expression.Moreover,transfection of cells with RAD51 gene decreased cellular sensitivity to methotrexate and γ-rays.The sensitizer enhancerment ratios after irradiation in combination with methotrexate were 1.51 and 0.99,respectively.Methotrenate was a preferred radiosensitizer to HOS cell.Conclusions RAD51 might be involved in the methotrexate-enhanced radiosensitivity.%目的 探讨同源重组修复蛋白RAD51与氨甲蝶呤辐射增敏作用的相关性.方法 分别采用Western blot和RT-PCR法,观察γ射线、氨甲蝶呤及二者联合应用对人骨肉瘤细胞RAD51表达的影响,克隆形成实验观察氨甲蝶呤对RAD51高表达前后骨肉瘤细胞辐射增敏作用的影响.结果 氨甲蝶呤在蛋白质和RNA水平抑制RAD51的表达,氨甲蝶呤和射线联合应用可明显降低RAD51的表达水平;HOS细胞和RAD51高表达的HOS-RAD51细胞加药前后的辐射增敏比分别为1.51和0.99,表明氨甲蝶呤对HOS细胞具有较好的放射增敏性.结论 RAD51可能参与了氨甲蝶呤的辐射增敏作用.

  16. Conditional inactivation of the DNA damage response gene Hus1 in mouse testis reveals separable roles for components of the RAD9-RAD1-HUS1 complex in meiotic chromosome maintenance.

    Directory of Open Access Journals (Sweden)

    Amy M Lyndaker

    Full Text Available The RAD9-RAD1-HUS1 (9-1-1 complex is a heterotrimeric PCNA-like clamp that responds to DNA damage in somatic cells by promoting DNA repair as well as ATR-dependent DNA damage checkpoint signaling. In yeast, worms, and flies, the 9-1-1 complex is also required for meiotic checkpoint function and efficient completion of meiotic recombination; however, since Rad9, Rad1, and Hus1 are essential genes in mammals, little is known about their functions in mammalian germ cells. In this study, we assessed the meiotic functions of 9-1-1 by analyzing mice with germ cell-specific deletion of Hus1 as well as by examining the localization of RAD9 and RAD1 on meiotic chromosomes during prophase I. Hus1 loss in testicular germ cells resulted in meiotic defects, germ cell depletion, and severely compromised fertility. Hus1-deficient primary spermatocytes exhibited persistent autosomal γH2AX and RAD51 staining indicative of unrepaired meiotic DSBs, synapsis defects, an extended XY body domain often encompassing partial or whole autosomes, and an increase in structural chromosome abnormalities such as end-to-end X chromosome-autosome fusions and ruptures in the synaptonemal complex. Most of these aberrations persisted in diplotene-stage spermatocytes. Consistent with a role for the 9-1-1 complex in meiotic DSB repair, RAD9 localized to punctate, RAD51-containing foci on meiotic chromosomes in a Hus1-dependent manner. Interestingly, RAD1 had a broader distribution that only partially overlapped with RAD9, and localization of both RAD1 and the ATR activator TOPBP1 to the XY body and to unsynapsed autosomes was intact in Hus1 conditional knockouts. We conclude that mammalian HUS1 acts as a component of the canonical 9-1-1 complex during meiotic prophase I to promote DSB repair and further propose that RAD1 and TOPBP1 respond to unsynapsed chromatin through an alternative mechanism that does not require RAD9 or HUS1.

  17. Conditional inactivation of the DNA damage response gene Hus1 in mouse testis reveals separable roles for components of the RAD9-RAD1-HUS1 complex in meiotic chromosome maintenance.

    Science.gov (United States)

    Lyndaker, Amy M; Lim, Pei Xin; Mleczko, Joanna M; Diggins, Catherine E; Holloway, J Kim; Holmes, Rebecca J; Kan, Rui; Schlafer, Donald H; Freire, Raimundo; Cohen, Paula E; Weiss, Robert S

    2013-01-01

    The RAD9-RAD1-HUS1 (9-1-1) complex is a heterotrimeric PCNA-like clamp that responds to DNA damage in somatic cells by promoting DNA repair as well as ATR-dependent DNA damage checkpoint signaling. In yeast, worms, and flies, the 9-1-1 complex is also required for meiotic checkpoint function and efficient completion of meiotic recombination; however, since Rad9, Rad1, and Hus1 are essential genes in mammals, little is known about their functions in mammalian germ cells. In this study, we assessed the meiotic functions of 9-1-1 by analyzing mice with germ cell-specific deletion of Hus1 as well as by examining the localization of RAD9 and RAD1 on meiotic chromosomes during prophase I. Hus1 loss in testicular germ cells resulted in meiotic defects, germ cell depletion, and severely compromised fertility. Hus1-deficient primary spermatocytes exhibited persistent autosomal γH2AX and RAD51 staining indicative of unrepaired meiotic DSBs, synapsis defects, an extended XY body domain often encompassing partial or whole autosomes, and an increase in structural chromosome abnormalities such as end-to-end X chromosome-autosome fusions and ruptures in the synaptonemal complex. Most of these aberrations persisted in diplotene-stage spermatocytes. Consistent with a role for the 9-1-1 complex in meiotic DSB repair, RAD9 localized to punctate, RAD51-containing foci on meiotic chromosomes in a Hus1-dependent manner. Interestingly, RAD1 had a broader distribution that only partially overlapped with RAD9, and localization of both RAD1 and the ATR activator TOPBP1 to the XY body and to unsynapsed autosomes was intact in Hus1 conditional knockouts. We conclude that mammalian HUS1 acts as a component of the canonical 9-1-1 complex during meiotic prophase I to promote DSB repair and further propose that RAD1 and TOPBP1 respond to unsynapsed chromatin through an alternative mechanism that does not require RAD9 or HUS1.

  18. Does the ion-molecule reaction between HC tbnd CH rad + and HCN lead to CH 2dbnd CH-C tbnd N rad + ? A computational and experimental study of the reverse process

    Science.gov (United States)

    Jobst, Karl J.; Hasan, Syed A.; Terlouw, Johan K.

    2008-01-01

    The title ion-molecule reaction has been proposed to play an important role in interstellar chemistry if it yields acrylonitrile ions CH 2dbnd CH-C tbnd N rad + . This question was probed by examining the formation of HC tbnd CH rad + and HCN from low-energy ions CH 2dbnd CH-C tbnd N rad + and related isomers, using tandem mass spectrometry based experiments (D and 13C labelling) in conjunction with model chemistry calculations (CBS-QB3/APNO). We conclude that the title reaction is a barrierless multistep rearrangement that may not effectively compete with the straightforward formation of stable distonic ions HC dbnd CH-N dbnd CH rad + from HC tbnd CH rad + (ion)-HCN(dipole) encounter complexes.

  19. Range Tracing

    OpenAIRE

    Jenke, Philipp; Huhle, Benjamin

    2010-01-01

    In this report, we tackle the problem of merging an arbitrary number of range scans (depth images) into a single surface mesh. The mesh-based representation is superior to point-based approaches since it contains important connectivity information. Most previous mesh-based merge methods, however, lose surface details by using simplifying intermediate surface representations (e.g.\\ implicit functions). Such details are essential for further processing steps, especially for feature-preserving r...

  20. Microstructures and Microwave Dielectric Properties of Na0.5Nd0.2Sm0.3Ti1- x Sn x O3 Ceramics ( x = 0.00 to 0.50)

    Science.gov (United States)

    Fang, Zixuan; Tang, Bin; Li, Yingxiang; Si, Feng; Zhang, Shuren

    2015-11-01

    In this work, frequency-stable Na0.5Nd0.2Sm0.3Ti1- x Sn x O3 ( x = 0.00, 0.01, 0.02, 0.05, 0.09, 0.14, 0.20, 0.30, 0.40, 0.50) ceramics with low dielectric loss were prepared by the conventional solid-state route. The effects of the Sn ratio on the structure, sintering behavior, and microwave dielectric properties of Na0.5Nd0.2Sm0.3Ti1- x Sn x O3 (NNST) were systematically investigated. All samples were indexed as having orthorhombic perovskite structure; replacement of Ti4+ by Sn4+ at the B-site occurred and increased the lattice parameters for x ≤ 0.4. ɛ r decreased monotonically with increasing Sn concentration. The quality factor could be significantly enhanced because of the improved densification, reaching a maximum value at x = 0.3. It was remarkable that the τ f value could be effectively tuned from a large value of 206 ppm/°C to near zero due to a continuously dramatic change of lattice structure. The results showed that the Sn content significantly influenced the microstructure and sintering behavior because of the appearance of liquid phase. NNST ceramic with x = 0.3 sintered at 1350°C for 2 h showed good microwave dielectric properties of ɛ r = 56, Q × f = 10,734 GHz, and τ f = 22 ppm/°C.

  1. Preferential repair in Saccharomyces cerevisiae rad mutants after induction of interstrand cross-links by 8-methoxypsoralen plus UVA.

    Science.gov (United States)

    Meniel, V; Magaña-Schwencke, N; Averbeck, D

    1995-11-01

    The gene specific induction and the incision step of the removal of 8-methoxypsoralen (8-MOP) plus UVA-induced interstrand cross-links (ICL) was measured in repair mutants of Saccharomyces cerevisiae. Events were examined at the MAT alpha and HML alpha loci in mutants deficient in the repair of ICL, namely rad1, rad2 delta, rad52, pso2 and the rad16 mutant which is impaired in the removal of UV-induced pyrimidine dimers from the silent HML alpha locus. Previously, we observed in a wild-type strain (K107) preferential repair concerning the incision of 8-MOP photo-induced ICL. The present study indicates that the two mutants rad1 and rad2 delta show no repair in either locus, due presumably to their deficiency in the incision step of ICL repair. The rad52 mutant which is defective in recombination, is proficient in the preferential incision of ICL at the MAT alpha locus versus the HML alpha locus. The same is true for the pso2 mutant which also lacks the ability to perform complete repair of ICL. The rad16 mutant is unable to repair ICL in the silent locus HML alpha but is proficient in repair (i.e. the incision of ICL) in the transcriptionally active MAT alpha locus.

  2. Differing requirements for RAD51 and DMC1 in meiotic pairing of centromeres and chromosome arms in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Olivier Da Ines

    Full Text Available During meiosis homologous chromosomes pair, recombine, and synapse, thus ensuring accurate chromosome segregation and the halving of ploidy necessary for gametogenesis. The processes permitting a chromosome to pair only with its homologue are not fully understood, but successful pairing of homologous chromosomes is tightly linked to recombination. In Arabidopsis thaliana, meiotic prophase of rad51, xrcc3, and rad51C mutants appears normal up to the zygotene/pachytene stage, after which the genome fragments, leading to sterility. To better understand the relationship between recombination and chromosome pairing, we have analysed meiotic chromosome pairing in these and in dmc1 mutant lines. Our data show a differing requirement for these proteins in pairing of centromeric regions and chromosome arms. No homologous pairing of mid-arm or distal regions was observed in rad51, xrcc3, and rad51C mutants. However, homologous centromeres do pair in these mutants and we show that this does depend upon recombination, principally on DMC1. This centromere pairing extends well beyond the heterochromatic centromere region and, surprisingly, does not require XRCC3 and RAD51C. In addition to clarifying and bringing the roles of centromeres in meiotic synapsis to the fore, this analysis thus separates the roles in meiotic synapsis of DMC1 and RAD51 and the meiotic RAD51 paralogs, XRCC3 and RAD51C, with respect to different chromosome domains.

  3. The rad52-Y66A allele alters the choice of donor template during spontaneous chromosomal recombination

    DEFF Research Database (Denmark)

    de Mayolo, A.A.; Sunjevaric, I.; Reid, R.;

    2010-01-01

    Spontaneous mitotic recombination is a potential source of genetic changes Such as loss of heterozygosity and chromosome translocations, which may lead to genetic disease. In this study we have used a rad52 hyper-recombination mutant, rad52-Y66A, to investigate the process of spontaneous heteroal...

  4. RAD50, an SMC family member with multiple roles in DNA break repair: How does ATP affect function?

    NARCIS (Netherlands)

    E. Kinoshita (Eri); E. van der Linden (Eddy); H. Sanchez (Humberto); C. Wyman (Claire)

    2009-01-01

    textabstractThe protein complex including Mre11, Rad50, and Nbs1 (MRN) functions in DNA double-strand break repair to recognize and process DNA ends as well as signal for cell cycle arrest. Amino acid sequence similarity and overall architecture make Rad50 a member of the structural maintenance of c

  5. Chromosomal Translocations in the Parasite Leishmania by a MRE11/RAD50-Independent Microhomology-Mediated End Joining Mechanism.

    Science.gov (United States)

    Laffitte, Marie-Claude N; Leprohon, Philippe; Hainse, Maripier; Légaré, Danielle; Masson, Jean-Yves; Ouellette, Marc

    2016-06-01

    The parasite Leishmania often relies on gene rearrangements to survive stressful environments. However, safeguarding a minimum level of genome integrity is important for cell survival. We hypothesized that maintenance of genomic integrity in Leishmania would imply a leading role of the MRE11 and RAD50 proteins considering their role in DNA repair, chromosomal organization and protection of chromosomes ends in other organisms. Attempts to generate RAD50 null mutants in a wild-type background failed and we provide evidence that this gene is essential. Remarkably, inactivation of RAD50 was possible in a MRE11 null mutant that we had previously generated, providing good evidence that RAD50 may be dispensable in the absence of MRE11. Inactivation of the MRE11 and RAD50 genes led to a decreased frequency of homologous recombination and analysis of the null mutants by whole genome sequencing revealed several chromosomal translocations. Sequencing of the junction between translocated chromosomes highlighted microhomology sequences at the level of breakpoint regions. Sequencing data also showed a decreased coverage at subtelomeric locations in many chromosomes in the MRE11-/-RAD50-/- parasites. This study demonstrates an MRE11-independent microhomology-mediated end-joining mechanism and a prominent role for MRE11 and RAD50 in the maintenance of genomic integrity. Moreover, we suggest the possible involvement of RAD50 in subtelomeric regions stability.

  6. Chromosomal Translocations in the Parasite Leishmania by a MRE11/RAD50-Independent Microhomology-Mediated End Joining Mechanism.

    Directory of Open Access Journals (Sweden)

    Marie-Claude N Laffitte

    2016-06-01

    Full Text Available The parasite Leishmania often relies on gene rearrangements to survive stressful environments. However, safeguarding a minimum level of genome integrity is important for cell survival. We hypothesized that maintenance of genomic integrity in Leishmania would imply a leading role of the MRE11 and RAD50 proteins considering their role in DNA repair, chromosomal organization and protection of chromosomes ends in other organisms. Attempts to generate RAD50 null mutants in a wild-type background failed and we provide evidence that this gene is essential. Remarkably, inactivation of RAD50 was possible in a MRE11 null mutant that we had previously generated, providing good evidence that RAD50 may be dispensable in the absence of MRE11. Inactivation of the MRE11 and RAD50 genes led to a decreased frequency of homologous recombination and analysis of the null mutants by whole genome sequencing revealed several chromosomal translocations. Sequencing of the junction between translocated chromosomes highlighted microhomology sequences at the level of breakpoint regions. Sequencing data also showed a decreased coverage at subtelomeric locations in many chromosomes in the MRE11-/-RAD50-/- parasites. This study demonstrates an MRE11-independent microhomology-mediated end-joining mechanism and a prominent role for MRE11 and RAD50 in the maintenance of genomic integrity. Moreover, we suggest the possible involvement of RAD50 in subtelomeric regions stability.

  7. Inactivation of RAD52 and HDF1 DNA repair genes leads to premature chronological aging and cellular instability

    Indian Academy of Sciences (India)

    SILVIA MERCADO-SÁENZ; BEATRIZ LÓPEZ-DÍAZ; FRANCISCO SENDRA-PORTERO; MANUEL MARTÍNEZ-MORILLO; MIGUEL J RUIZ-GÓMEZ

    2017-06-01

    The present study aims to investigate the role of radiation sensitive 52 (RAD52) and high-affinity DNA binding factor1 (HDF1) DNA repair genes on the life span of budding yeasts during chronological aging. Wild type (wt) and rad52,hdf1, and rad52 hdf1 mutant Saccharomyces cerevisiae strains were used. Chronological aging and survival assayswere studied by clonogenic assay and drop test. DNA damage was analyzed by electrophoresis after phenol extraction.Mutant analysis, colony forming units and the index of respiratory competence were studied by growing on dextroseand glycerol plates as a carbon source. Rad52 and rad52 hdf1 mutants showed a gradual decrease in surviving fractionin relation to wt and hdf1 mutant during aging. Genomic DNA was spontaneously more degraded during aging,mainly in rad52 mutants. This strain showed an increased percentage of revertant colonies. Moreover, all mutantsshowed a decrease in the index of respiratory competence during aging. The inactivation of RAD52 leads to prematurechronological aging with an increase in DNA degradation and mutation frequency. In addition, RAD52 and HDF1contribute to maintain the metabolic state, in a different way, during chronological aging. The results obtained couldhave important implications in the chronobiology of aging.

  8. Melanoma Development and Progression Are Associated with Rad6 Upregulation and β-Catenin Relocation to the Cell Membrane

    Directory of Open Access Journals (Sweden)

    Karli Rosner

    2014-01-01

    Full Text Available We have previously demonstrated that Rad6 and β-catenin enhance each other's expression through a positive feedback loop to promote breast cancer development/progression. While β-catenin has been implicated in melanoma pathogenesis, Rad6 function has not been investigated. Here, we examined the relationship between Rad6 and β-catenin in melanoma development and progression. Eighty-eight cutaneous tumors, 30 nevi, 29 primary melanoma, and 29 metastatic melanomas, were immunostained with anti-β-catenin and anti-Rad6 antibodies. Strong expression of Rad6 was observed in only 27% of nevi as compared to 100% of primary and 96% of metastatic melanomas. β-Catenin was strongly expressed in 97% of primary and 93% of metastatic melanomas, and unlike Rad6, in 93% of nevi. None of the tumors expressed nuclear β-catenin. β-Catenin was exclusively localized on the cell membrane of 55% of primary, 62% of metastatic melanomas, and only 10% of nevi. Cytoplasmic β-catenin was detected in 90% of nevi, 17% of primary, and 8% of metastatic melanoma, whereas 28% of primary and 30% of metastatic melanomas exhibited β-catenin at both locations. These data suggest that melanoma development and progression are associated with Rad6 upregulation and membranous redistribution of β-catenin and that β-catenin and Rad6 play independent roles in melanoma development.

  9. Cohesin Rad21 Mediates Loss of Heterozygosity and Is Upregulated via Wnt Promoting Transcriptional Dysregulation in Gastrointestinal Tumors

    Directory of Open Access Journals (Sweden)

    Huiling Xu

    2014-12-01

    Full Text Available Loss of heterozygosity (LOH of the adenomatous polyposis coli (APC gene triggers a series of molecular events leading to intestinal adenomagenesis. Haploinsufficiency of the cohesin Rad21 influences multiple initiating events in colorectal cancer (CRC. We identify Rad21 as a gatekeeper of LOH and a β-catenin target gene and provide evidence that Wnt pathway activation drives RAD21 expression in human CRC. Genome-wide analyses identified Rad21 as a key transcriptional regulator of critical CRC genes and long interspersed element (LINE-1 or L1 retrotransposons. Elevated RAD21 expression tracks with reactivation of L1 expression in human sporadic CRC, implicating cohesin-mediated L1 expression in global genomic instability and gene dysregulation in cancer.

  10. Influence of different inhibitors on the activity of the RAD54 dependent step of DNA repair in Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Siede, W.; Obermaier, S.; Eckhardt, F.

    1985-01-01

    The recombinagenic pathway of DNA repair in yeast was characterized by the effect of different inhibitors on the temperature-dependent survival after ..gamma..-irradiation in haploid cells of the thermoconditional mutant rad54-3. Blocking protein synthesis with cycloheximide in replicating cells caused partial inhibition of the RAD54 dependent function but some repair activity remained detectable. This indicates that ..gamma..-rays can induce RAD54 activity above some constitutive level of function. Inhibition of DNA replication by hydroxyurea efficiently blocked the RAD54 dependent function in stationary-phase cells but not in logarithmic-phase cells. In logarithmic-phase cells, the authors found a strong inhibitory effect of caffeine on the RAD54 mediated repair process.

  11. Human RAD6 Promotes G1-S Transition and Cell Proliferation through Upregulation of Cyclin D1 Expression

    Science.gov (United States)

    Biskup, Ewelina; Liu, Yan; Chen, Pei-Chao; Chang, Jian-Feng; Jiang, Wenjie; Jing, Yuanya; Chen, Youwei; Jin, Hui; Chen, Su

    2014-01-01

    Protein ubiquitinylation regulates protein stability and activity. RAD6, an E2 ubiquitin-conjugating enzyme, which that has been substantially biochemically characterized, functions in a number of biologically relevant pathways, including cell cycle progression. In this study, we show that RAD6 promotes the G1-S transition and cell proliferation by regulating the expression of cyclin D1 (CCND1) in human cells. Furthermore, our data indicate that RAD6 influences the transcription of CCND1 by increasing monoubiquitinylation of histone H2B and trimethylation of H3K4 in the CCND1 promoter region. Our study presents, for the first time, an evidence for the function of RAD6 in cell cycle progression and cell proliferation in human cells, raising the possibility that RAD6 could be a new target for molecular diagnosis and prognosis in cancer therapeutics. PMID:25409181

  12. Human RAD6 promotes G1-S transition and cell proliferation through upregulation of cyclin D1 expression.

    Directory of Open Access Journals (Sweden)

    Fengfeng Cai

    Full Text Available Protein ubiquitinylation regulates protein stability and activity. RAD6, an E2 ubiquitin-conjugating enzyme, which that has been substantially biochemically characterized, functions in a number of biologically relevant pathways, including cell cycle progression. In this study, we show that RAD6 promotes the G1-S transition and cell proliferation by regulating the expression of cyclin D1 (CCND1 in human cells. Furthermore, our data indicate that RAD6 influences the transcription of CCND1 by increasing monoubiquitinylation of histone H2B and trimethylation of H3K4 in the CCND1 promoter region. Our study presents, for the first time, an evidence for the function of RAD6 in cell cycle progression and cell proliferation in human cells, raising the possibility that RAD6 could be a new target for molecular diagnosis and prognosis in cancer therapeutics.

  13. Effects of the rad52 gene on recombination in Saccharomyces cerevisiae. [Comparison of. gamma. -, uv-induced meiotic and spontaneous mitotic recombination

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, S.; Prakash, L.; Burke, W.; Montelone, B.A.

    1979-01-01

    Effects of the rad52 mutation in Saccharomyces cerevisiae on meiotic, ..gamma..-ray-induced, uv-induced, and spontaneous mitotic recombination were studied. The rad52/rad52 diploids undergo premeiotic DNA synthesis; sporulation occurs but inviable spores are produced. Intra- and intergenic recombination during meiosis were examined in cells transferred from sporulation medium to vegetative medium at different time intervals. No intragenic recombination was observed at the hisl-1/hisl-315 and trp5-2/trp5-48 heteroalleles. Gene-centromere recombination was also not observed in rad52/rad52 diploids. No ..gamma..-ray-induced intragenic mitotic recombination is seen in rad52/rad52 diploids and uv-induced intragenic recombination is greatly reduced. However, spontaneous mitotic recombination is not similarly affected. The RAD52 gene thus functions in recombination in meiosis and in ..gamma..-ray and uv-induced mitotic recombination but not in spontaneous mitotic recombination.

  14. Comparison of Inter-Observer Variability and Diagnostic Performance of the Fifth Edition of BI-RADS for Breast Ultrasound of Static versus Video Images.

    Science.gov (United States)

    Youk, Ji Hyun; Jung, Inkyung; Yoon, Jung Hyun; Kim, Sung Hun; Kim, You Me; Lee, Eun Hye; Jeong, Sun Hye; Kim, Min Jung

    2016-09-01

    Our aim was to compare the inter-observer variability and diagnostic performance of the Breast Imaging Reporting and Data System (BI-RADS) lexicon for breast ultrasound of static and video images. Ninety-nine breast masses visible on ultrasound examination from 95 women 19-81 y of age at five institutions were enrolled in this study. They were scheduled to undergo biopsy or surgery or had been stable for at least 2 y of ultrasound follow-up after benign biopsy results or typically benign findings. For each mass, representative long- and short-axis static ultrasound images were acquired; real-time long- and short-axis B-mode video images through the mass area were separately saved as cine clips. Each image was reviewed independently by five radiologists who were asked to classify ultrasound features according to the fifth edition of the BI-RADS lexicon. Inter-observer variability was assessed using kappa (κ) statistics. Diagnostic performance on static and video images was compared using the area under the receiver operating characteristic curve. No significant difference was found in κ values between static and video images for all descriptors, although κ values of video images were higher than those of static images for shape, orientation, margin and calcifications. After receiver operating characteristic curve analysis, the video images (0.83, range: 0.77-0.87) had higher areas under the curve than the static images (0.80, range: 0.75-0.83; p = 0.08). Inter-observer variability and diagnostic performance of video images was similar to that of static images on breast ultrasonography according to the new edition of BI-RADS.

  15. RAD50 and NBS1 form a stable complex functional in DNA binding and tethering

    NARCIS (Netherlands)

    E. van der Linden (Eddy); H. Sanchez (Humberto); E. Kinoshita (Eri); R. Kanaar (Roland); C. Wyman (Claire)

    2009-01-01

    textabstractThe RAD50/MRE11/NBS1 protein complex (RMN) plays an essential role during the early steps of DNA double-strand break (DSB) repair by homologous recombination. Previous data suggest that one important role for RMN in DSB repair is to provide a link between DNA ends. The striking architect

  16. Modified Bi-Rads Scoring of Breast Imaging Findings Improves Clinical Judgment.

    Science.gov (United States)

    Silberman, Howard; Sheth, Pulin A; Parisky, Yuri R; Hovanessian-Larsen, Linda J; Sheth, Sindu; Tripathy, Debasish

    2015-01-01

    In contrast with the reporting requirements currently mandated under the Federal Mammography Quality Standards Act (MQSA), we propose a modification of the Breast Imaging Reporting and Data System (Bi-Rads) in which a concluding assessment category is assigned, not to the examination as a whole, but to every potentially malignant abnormality observed. This modification improves communication between the radiologist and the attending clinician, thereby facilitating clinical judgment leading to appropriate management. In patients with breast cancer eligible for breast conserving therapy, application of this modification brings to attention the necessity for such patients to undergo pretreatment biopsies of all secondary, synchronous ipsilateral lesions scored Bi-Rads 3-5. All contralateral secondary lesions scored Bi-Rads 3-5 also require pretreatment biopsies. The application of this modification of the MSQA demonstrates the necessity to alter current recommendations ("short-interval follow-up") for secondary, synchronous Bi-Rads 3 ("probably benign") image-detected abnormalities prior to treatment of the index malignancy. © 2015 Wiley Periodicals, Inc.

  17. Study on Performance of Empore~(TM) Strontium Rad Disks-Ⅱ

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    EmporeTM Strontium Rad disks produced by 3M Company contain a strontium-selective crown ether extractant loaded on silica particles that are embedded in an inert PTFE matrix. The disks allow aqueous solutions to pass through in high flow rate. It makes

  18. Rad51 inhibits translocation formation by non-conservative homologous recombination in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Glenn M Manthey

    Full Text Available Chromosomal translocations are a primary biological response to ionizing radiation (IR exposure, and are likely to result from the inappropriate repair of the DNA double-strand breaks (DSBs that are created. An abundance of repetitive sequences in eukaryotic genomes provides ample opportunity for such breaks to be repaired by homologous recombination (HR between non-allelic repeats. Interestingly, in the budding yeast, Saccharomyces cerevisiae the central strand exchange protein, Rad51 that is required for DSB repair by gene conversion between unlinked repeats that conserves genomic structure also suppresses translocation formation by several HR mechanisms. In particular, Rad51 suppresses translocation formation by single-strand annealing (SSA, perhaps the most efficient mechanism for translocation formation by HR in both yeast and mammalian cells. Further, the enhanced translocation formation that emerges in the absence of Rad51 displays a distinct pattern of genetic control, suggesting that this occurs by a separate mechanism. Since hypomorphic mutations in RAD51 in mammalian cells also reduce DSB repair by conservative gene conversion and stimulate non-conservative repair by SSA, this mechanism may also operate in humans and, perhaps contribute to the genome instability that propels the development of cancer.

  19. Suppression of mutagenesis by Rad51D-mediated homologous recombination

    Energy Technology Data Exchange (ETDEWEB)

    Hinz, J M; Tebbs, R S; Wilson, P F; Nham, P B; Salazar, E P; Nagasawa, H; Urbin, S S; Thompson, L H

    2005-11-15

    Homologous recombinational repair (HRR) restores chromatid breaks arising during DNA replication and prevents chromosomal rearrangements that can occur from the misrepair of such breaks. In vertebrates, five Rad51 paralogs are identified that contribute in a nonessential but critical manner to HRR efficiency. We constructed and characterized a Rad51D knockout cell line in widely studied CHO cells. The rad51d mutant (51D1) displays sensitivity to a wide spectrum of induced DNA damage, indicating the broad relevance of HRR to genotoxicity. Untreated 51D1 cells exhibit {approx}5-fold elevated chromosomal breaks, a 12-fold increased rate of hprt mutation, and 4- to 10-fold increased rates of gene amplification at the dhfr and CAD loci, respectively. These results explicitly show the quantitative importance of HHR in preventing these types genetic alterations, which are associated with carcinogenesis. Thus, HRR copes in an error-free manner with spontaneous DNA damage encountered during DNA replication, and Rad51D is essential for this fidelity.

  20. Genomics and introgression: discovery and mapping of thousands of species-diagnostic SNPs using RAD sequencing

    Science.gov (United States)

    Hand, Brian K; Hether, Tyler D; Kovach, Ryan P.; Muhlfeld, Clint C.; Amish, Stephen J.; Boyer, Matthew C.; O’Rourke, Sean M.; Miller, Michael R.; Lowe, Winsor H.; Hohenlohe, Paul A.; Luikart, Gordon

    2015-01-01

    Invasive hybridization and introgression pose a serious threat to the persistence of many native species. Understanding the effects of hybridization on native populations (e.g., fitness consequences) requires numerous species-diagnostic loci distributed genome-wide. Here we used RAD sequencing to discover thousands of single-nucleotide polymorphisms (SNPs) that are diagnostic between rainbow trout (RBT, Oncorhynchus mykiss), the world’s most widely introduced fish, and native westslope cutthroat trout (WCT, O. clarkii lewisi) in the northern Rocky Mountains, USA. We advanced previous work that identified 4,914 species-diagnostic loci by using longer sequence reads (100 bp vs. 60 bp) and a larger set of individuals (n = 84). We sequenced RAD libraries for individuals from diverse sampling sources, including native populations of WCT and hatchery broodstocks of WCT and RBT. We also took advantage of a newly released reference genome assembly for RBT to align our RAD loci. In total, we discovered 16,788 putatively diagnostic SNPs, 10,267 of which we mapped to anchored chromosome locations on the RBT genome. A small portion of previously discovered putative diagnostic loci (325 of 4,914) were no longer diagnostic (i.e., fixed between species) based on our wider survey of non-hybridized RBT and WCT individuals. Our study suggests that RAD loci mapped to a draft genome assembly could provide the marker density required to identify genes and chromosomal regions influencing selection in admixed populations of conservation concern and evolutionary interest.

  1. Relation between radiographic BI-RADS scores and triple negativity in patients with ductal carcinomas.

    Science.gov (United States)

    Oktay, Murat; Oktay, Nilay Aydın; Besir, Fahri Halit; Buyukkaya, Ramazan; Erdem, Havva; Onal, Binnur; Ozaydın, Ismet; Yazıcı, Burhan

    2014-01-01

    The aim of this study was to investigate association of radiographic (BI-RADS 4 and 5) results and prognostic factors of invasive ductal carcinomas with their histopathological subtypes. A total of 103 patients histopathologically diagnosed with invasive ductal carcinoma of breast with in last five years period were enrolled. Of them, 69 patients who had radiological reports in were included from registry of Radiology Department; Duzce University Training and Research Hospital archives. BI-RADS scores (4 and 5) of radiological reports and subtypes of ductal carcinoma were compared. Of 69 cases, 12 of 22 cases with BIRADS 4 score were Triple negative (TN) while 5 of 47 cases with BIRADS 5 score were TN (p = 0.001). The patients with TN tumors were found to have lower average age, higher grade, higher Ki67 proliferative index and fewer lymph node metastasis than those with non-TN ductal carcinomas (p = 0.048; 0.019; 0.02; 0.048 respectively). Patients who had radiological BIRADS 4 score were significantly more frequent TN type carcinoma than BI-RADS 5. It is important to pay attention to this issue when clinicians evaluate patients with BI-RADS 4 score breast lesions.

  2. Real-time assembly and disassembly of human RAD51 filaments on individual DNA molecules

    NARCIS (Netherlands)

    Van der Heijden, T.; Seidel, R.; Modesti, M.; Kanaar, R.; Wyman, C.; Dekker, C.

    2007-01-01

    The human DNA repair protein RAD51 is the crucial component of helical nucleoprotein filaments that drive homologous recombination. The molecular mechanistic details of how this structure facilitates the requisite DNA strand rearrangements are not known but must involve dynamic interactions between

  3. Real-time assembly and disassembly of human RAD51 filaments on individual DNA molecules

    NARCIS (Netherlands)

    T. van der Heijden (Thijn); R. Seidel (Ralf); M. Modesti (Mauro); R. Kanaar (Roland); C. Wyman (Claire); C. Dekker (Cees)

    2007-01-01

    textabstractThe human DNA repair protein RAD51 is the crucial component of helical nucleoprotein filaments that drive homologous recombination. The molecular mechanistic details of how this structure facilitates the requisite DNA strand rearrangements are not known but must involve dynamic

  4. Amelioration of Radiation-Induced Hematopoietic and Gastrointestinal Damage by Ex-RAD (trademark) in Mice

    Science.gov (United States)

    2012-06-06

    injections of the drug and vehicle in animals were done aseptically at the nape of the neck with a 23-G needle before irradiation. No infection or local...compared with vehicle control. Fig. 6. Crypts per circumference of jejunum sections from Ex-RAD-treated and vehicle-treated groups 12 h and 3.5 days post

  5. Involvement of ATM in homologous recombination after end resection and RAD51 nucleofilament formation.

    Science.gov (United States)

    Bakr, A; Oing, C; Köcher, S; Borgmann, K; Dornreiter, I; Petersen, C; Dikomey, E; Mansour, W Y

    2015-03-31

    Ataxia-telangiectasia mutated (ATM) is needed for the initiation of the double-strand break (DSB) repair by homologous recombination (HR). ATM triggers DSB end resection by stimulating the nucleolytic activity of CtIP and MRE11 to generate 3'-ssDNA overhangs, followed by RPA loading and RAD51 nucleofilament formation. Here we show for the first time that ATM is also needed for later steps in HR after RAD51 nucleofilament formation. Inhibition of ATM after completion of end resection did not affect RAD51 nucleofilament formation, but resulted in HR deficiency as evidenced by (i) an increase in the number of residual RAD51/γH2AX foci in both S and G2 cells, (ii) the decrease in HR efficiency as detected by HR repair substrate (pGC), (iii) a reduced SCE rate and (iv) the radiosensitization of cells by PARP inhibition. This newly described role for ATM was found to be dispensable in heterochromatin-associated DSB repair, as KAP1-depletion did not alleviate the HR-deficiency when ATM was inhibited after end resection. Moreover, we demonstrated that ATR can partly compensate for the deficiency in early, but not in later, steps of HR upon ATM inhibition. Taken together, we describe here for the first time that ATM is needed not only for the initiation but also for the completion of HR.

  6. Magnetic resonance imaging of the prostate: interpretation using the PI-RADS V2.

    Science.gov (United States)

    Torregrosa Andrés, A; Otero García, M; Sineiro Galiñanes, M

    Version 2 of the Prostate Imaging and Reporting and Data System (PI-RADS) was developed to help in the detection, location, and characterization of prostate cancer with magnetic resonance imaging (MRI). Its recommendations for standardizing image acquisition parameters aims to reduce variability in the interpretation of MRI studies of the prostate; this approach, together with structured reporting, has the added value of improving communication among radiologists and between radiologists and urologists. This article aims to explain the PI-RADS v2 classification in a simple way, using illustrative images for each of the categories, as well as to recommend the use of a standard technique that helps ensure the reproducibility of multiparametric MRI. The PI-RADS v2 is simple to appy when reading multiparametric MRI studies of the prostate. It is important for radiologists doing prostate imaging to use the PI-RADS v2 in daily practice to write clear and concise reports that improve communication between radiologists and urologists. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Entwicklung einer Norm zur indirekten Bestimmung der Rad-Schiene-Rauheit aus der Messung von Schienenschwindungen

    NARCIS (Netherlands)

    Dittrich, M.G.; Engels, R.; Dupuis, H.; Meunier, N.

    2012-01-01

    Der Normungsausschuss CEN TC256/WG3 Subgroup E befasst sich zurzeit mit dem Thema der indirekten Bestimmung der Rad-Schiene-Rauheit aus Schienenschwingungen. In diesem Zusammenhang wurden zur Vorbereitung einer Norm verschiedene Analyseverfahren in Hin-blick auf deren Repräsentativität, Wiederholbar

  8. Identification of novel functional domains of Rad52 in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Plate, Iben

    2006-01-01

    , som er den foretrukne reparationsmekanisme i bagegæren Saccharomyces cerevisiae, som derfor ofte anvendes som modelorganisme til at studere homolog rekombination. Reparationsvejen homolog rekombination, samt mange af de proteiner der virker i denne, er evolutionært bevaret fra gær til menneske. S....... cerevisiae er desuden nem at manipulere genetisk og der eksisterer sofistikerede in vivo assays som muliggør visualisering af reparationsprocessen ved hjælp af fluorescensmikroskopi. Rad52 er et vigtigt protein til reparation af DNA DSB i S. cerevisiae og rad52Δ celler har en alvorlig fænotype med langsom...... betingelser. Ovennævnte studie præsenterer for første gang tilstedeværelsen af tre nye funktionelle domæner i S. cerevisiae Rad52. Det understreger vigtigheden af Rad52, dette multifunktionelle protein i homolog rekombination og giver ny forståelse for en reparationsmekanisme, som er så vigtig...

  9. BI-RADS CATEGORIZATION AND POSITIVE PREDICTIVE VALUE OF MAMMOGRAPHIC FEATURES

    Institute of Scientific and Technical Information of China (English)

    TANG; Rui-ying

    2001-01-01

    [1]American College of Radiology (ACR). Breast imaging reporting and data system (BI-RADS) [M]. 3rd ed. Reston, VA: American College of Radiology, 1998.[2]Laura L, Andrea FA, Fredric BS, et al. The breast imaging reporting and data system: positive predictive value of mammographic features and final assessment categories [J]. AJR 1998; 171:35.[3]Susan GO, Nicole K, Carol R, et al. BI-RADS categorization as a predictor of malignancy [J]. Radiology 1999; 211:845.[4]Jay AB, Phyllis JK, Carey EF. Breast imaging reporting and data system standardized mammography lexicon: observer variability in lesion description [J]. AJR 1996; 166:773.[5]Berg WA, Campassi, Sexton MJ, et al. Analysis of sources of variation in mammographic interpretation [J]. Radiology 1997; 205:447.[6]Daniel BK. Standardized mammography reporting [J]. Radiologic Clinics of North America 1992; 30:257.[7]Jay AB, Phyllis JK, Joseph YL, et al. Breast cancer: prediction with artificial neural network based on BI-RADS standardized lexicon [J]. Radiology 1995; 196:817.[8]Berube M, Curpen B, Ugolini P, et al. Level of suspicion of a mammographic lesion: use of features defined by BI-RADS lexicon and correlation with large core breast biopsy [J]. Can Assoc Radiol J 1998; 49:223.

  10. A role for RAD51 and homologous recombination in Trypanosoma brucei antigenic variation.

    Science.gov (United States)

    McCulloch, R; Barry, J D

    1999-11-01

    Antigenic variation is an immune evasion strategy used by African trypanosomes, in which the parasites periodically switch the expression of VSG genes that encode their protective variant surface glycoprotein coat. Two main routes exist for VSG switching: changing the transcriptional status between an active and an inactive copy of the site of VSG expression, called the bloodstream VSG expression site, or recombination reactions that move silent VSGs or VSG copies into the actively transcribed expression site. Nothing is known about the proteins that control and catalyze these switching reactions. This study describes the cloning of a trypanosome gene encoding RAD51, an enzyme involved in DNA break repair and genetic exchange, and analysis of the role of the enzyme in antigenic variation. Trypanosomes genetically inactivated in the RAD51 gene were shown to be viable, and had phenotypes consistent with lacking functional expression of an enzyme of homologous recombination. The mutants had an impaired ability to undergo VSG switching, and it appeared that both recombinational and transcriptional switching reactions were down-regulated, indicating that RAD51 either catalyzes or regulates antigenic variation. Switching events were still detectable, however, so it appears that trypanosome factors other than RAD51 can also provide for antigenic variation.

  11. Caffeine stabilizes Cdc25 independently of Rad3 in S chizosaccharomyces pombe contributing to checkpoint override

    Science.gov (United States)

    Alao, John P; Sjölander, Johanna J; Baar, Juliane; Özbaki-Yagan, Nejla; Kakoschky, Bianca; Sunnerhagen, Per

    2014-01-01

    Cdc25 is required for Cdc2 dephosphorylation and is thus essential for cell cycle progression. Checkpoint activation requires dual inhibition of Cdc25 and Cdc2 in a Rad3-dependent manner. Caffeine is believed to override activation of the replication and DNA damage checkpoints by inhibiting Rad3-related proteins in both S chizosaccharomyces pombe and mammalian cells. In this study, we have investigated the impact of caffeine on Cdc25 stability, cell cycle progression and checkpoint override. Caffeine induced Cdc25 accumulation in S . pombe independently of Rad3. Caffeine delayed cell cycle progression under normal conditions but advanced mitosis in cells treated with replication inhibitors and DNA-damaging agents. In the absence of Cdc25, caffeine inhibited cell cycle progression even in the presence of hydroxyurea or phleomycin. Caffeine induces Cdc25 accumulation in S . pombe by suppressing its degradation independently of Rad3. The induction of Cdc25 accumulation was not associated with accelerated progression through mitosis, but rather with delayed progression through cytokinesis. Caffeine-induced Cdc25 accumulation appears to underlie its ability to override cell cycle checkpoints. The impact of Cdc25 accumulation on cell cycle progression is attenuated by Srk1 and Mad2. Together our findings suggest that caffeine overrides checkpoint enforcement by inducing the inappropriate nuclear localization of Cdc25. PMID:24666325

  12. Rad Hard Imaging Array with Picosecond Timing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For a wide range of remote sensing applications, there is a critical need to develop imaging arrays that simultaneously achieve high spatial resolution, high...

  13. El radón: ¿riesgo para la salud?

    Directory of Open Access Journals (Sweden)

    Juan Miguel Barros Dios

    2011-12-01

    Full Text Available El radón (Rn222 es un gas noble radiactivo que procede directamente del radio (Ra226 cuando este emite una partícula alfa (dos protones y dos neutrones o núcleo de helio, y que a su vez se transforma en otro elemento radiactivo (Po218 al desprenderse de otra partícula alfa. Desde hace varias décadas se conoce su efecto como factor de riesgo del cáncer primario pulmonar, primero en mineros del uranio y posteriormente en la población general expuesta al radón residencial en hogares construidos sobre suelos de rocas ricas en uranio (U238, elemento inicial de la cadena de degradación radiactiva de la que procede el radón. Áreas geológicamente constituidas por granitos o pizarras, como son las de gran parte de Galicia y todo el noroeste y oeste de la península ibérica, han sido catalogadas como de alto riesgo de exhalación de radón al interior de edificios y domicilios. En numerosos países de América y Europa existen desde hace varios lustros, políticas de prevención del cáncer pulmonar en aquellas zonas de riesgo basadas en programas de reducción de radón en los domicilios y edificios públicos. Desde finales de los años 80, la radiación alfa procedente del radón y sus descen- dientes de vida media corta han sido clasificados como agentes cancerígenos por la Internacional Agency of Research on Cancer (Lyon, 1988 y el Nacional Research Council (BEIR IV, 1988, constituyendo la segunda causa de cáncer pulmonar después del tabaco, y responsable del 10 al 15 % de todas las muertes por esa neoplasia. Estudios realizados en Galicia confirman esta evidencia, con riesgos de 2 a 3 en expuestos a concentraciones del gas en domicilios y la responsabilidad directa del 9% de todos los casos de cáncer pulmonar del área estudiada y una interacción radón/tabaco que multiplica por 45 el riesgo.

  14. A conserved sequence extending motif III of the motor domain in the Snf2-family DNA translocase Rad54 is critical for ATPase activity.

    Directory of Open Access Journals (Sweden)

    Xiao-Ping Zhang

    Full Text Available Rad54 is a dsDNA-dependent ATPase that translocates on duplex DNA. Its ATPase function is essential for homologous recombination, a pathway critical for meiotic chromosome segregation, repair of complex DNA damage, and recovery of stalled or broken replication forks. In recombination, Rad54 cooperates with Rad51 protein and is required to dissociate Rad51 from heteroduplex DNA to allow access by DNA polymerases for recombination-associated DNA synthesis. Sequence analysis revealed that Rad54 contains a perfect match to the consensus PIP box sequence, a widely spread PCNA interaction motif. Indeed, Rad54 interacts directly with PCNA, but this interaction is not mediated by the Rad54 PIP box-like sequence. This sequence is located as an extension of motif III of the Rad54 motor domain and is essential for full Rad54 ATPase activity. Mutations in this motif render Rad54 non-functional in vivo and severely compromise its activities in vitro. Further analysis demonstrated that such mutations affect dsDNA binding, consistent with the location of this sequence motif on the surface of the cleft formed by two RecA-like domains, which likely forms the dsDNA binding site of Rad54. Our study identified a novel sequence motif critical for Rad54 function and showed that even perfect matches to the PIP box consensus may not necessarily identify PCNA interaction sites.

  15. Simple rules for ultrasonographic subcategorization of BI-RADS{sup ®}-US 4 breast masses

    Energy Technology Data Exchange (ETDEWEB)

    Jales, Rodrigo Menezes, E-mail: rodrigoj@hotmail.com [Department of Obstetrics and Gynecology, Faculty of Medical Sciences, State University of Campinas – Unicamp, Campinas, São Paulo (Brazil); Sarian, Luís Otavio, E-mail: luis.sarian@gmail.com [Department of Obstetrics and Gynecology, Faculty of Medical Sciences, State University of Campinas – Unicamp, Campinas, São Paulo (Brazil); Torresan, Renato, E-mail: torresan@terra.com.br [Department of Obstetrics and Gynecology, Faculty of Medical Sciences, State University of Campinas – Unicamp, Campinas, São Paulo (Brazil); Marussi, Emílio Francisco, E-mail: efmarussi@uol.com.br [Department of Obstetrics and Gynecology, Faculty of Medical Sciences, State University of Campinas – Unicamp, Campinas, São Paulo (Brazil); Álvares, Beatriz Regina, E-mail: alvaresb@terra.com.br [Department of Radiology, Faculty of Medical Sciences, State University of Campinas – Unicamp, Campinas, São Paulo (Brazil); Derchain, Sophie, E-mail: derchain@fcm.unicamp.br [Department of Obstetrics and Gynecology, Faculty of Medical Sciences, State University of Campinas – Unicamp, Campinas, São Paulo (Brazil)

    2013-08-15

    Objectives: To evaluate an objective method for ultrasonographic (US) subcategorization of BI-RADS{sup ®}-US 4 breast masses based on clear and simple rules in order for woman to benefit from a more complete and homogeneous breast mass analysis. Methods: In this cross-sectional study, we selected 330 women, with 339 US breast masses, classified as BI-RADS{sup ®}-US 4. Three physicians experienced in breast imaging independently reviewed all US images, assessing mass shape, margins, orientation, echo texture and vascularity. These experts further subdivided the masses into subcategories 4a, 4b and 4c, according to simple US rules. Inter-observer agreement was calculated for US features categories and for final subcategory assessment. We also estimated the positive predictive value (PPV) for BI-RADS{sup ®}-US subcategories 4a, 4b and 4c assigned by each of the three observers. Results: Pathological examination of all masses confirmed 144 (42%) malignant and 195 (58%) benign tumors. Moderate agreement was obtained for mass shape, margins, vascularity and for final BI-RADS{sup ®}-US 4 subcategory. Substantial agreement was obtained for the description of mass orientation and echo texture. The PPV for subcategories 4a, 4b and 4c were, 17%, 45% and 85%, respectively, for the first observer and 20%, 38% and 79% and 17%, 40% and 85% for the other two observers. Conclusion: Standardization of a US subcategorization of BI-RADS{sup ®}-US 4 breast masses seems to be feasible, with substantial inter-observer agreement and progressive increase in the PPV in the subcategories 4a, 4b and 4c, provided that clear and simple classification rules are defined.

  16. Characterisation of the SUMO-like domains of Schizosaccharomyces pombe Rad60.

    Directory of Open Access Journals (Sweden)

    Lara K Boyd

    Full Text Available The S. pombe Rad60 protein is required for the repair of DNA double strand breaks, recovery from replication arrest, and is essential for cell viability. It has two SUMO-like domains (SLDs at its C-terminus, an SXS motif and three sequences that have been proposed to be SUMO-binding motifs (SBMs. SMB1 is located in the middle of the protein, SBM2 is in SLD1 and SBM3 is at the C-terminus of SLD2. We have probed the functions of the two SUMO-like domains, SLD1 and SLD2, and the putative SBMs. SLD1 is essential for viability, while SLD2 is not. rad60-SLD2Δ cells are sensitive to DNA damaging agents and hydroxyurea. Neither ubiquitin nor SUMO can replace SLD1 or SLD2. Cells in which either SBM1 or SBM2 has been mutated are viable and are wild type for response to MMS and HU. In contrast mutation of SBM3 results in significant sensitivity to MMS and HU. These results indicate that the lethality resulting from deletion of SLD1 is not due to loss of SBM2, but that mutation of SBM3 produces a more severe phenotype than does deletion of SLD2. Using chemical denaturation studies, FPLC and dynamic light scattering we show this is likely due to the destabilisation of SLD2. Thus we propose that the region corresponding to the putative SBM3 forms part of the hydrophobic core of SLD2 and is not a SUMO-interacting motif. Over-expression of Hus5, which is the SUMO conjugating enzyme and known to interact with Rad60, does not rescue rad60-SLD2Δ, implying that as well as having a role in the sumoylation process as previously described, Rad60 has a Hus5-independent function.

  17. Is the BI-RADS Categorization Valuable for Nonpalpable Breast Lesions in Chinese Women?

    Institute of Scientific and Technical Information of China (English)

    Zhongzhao Wang; Baoning Zhang; Jing Li; Liming Jiang

    2005-01-01

    OBJECTIVE To evaluate the feasibility of the Breast Imaging Reporting and Data System (BI-RADS) in the categorization of nonpalpable breast lesions (NPBLs) and to determine its value in aiding decision-making for biopsy in a Chinese population.METHODS One hundred and seventy-four nonpalpable breast lesions in 155 female patients examined by mammography were retrospectively categorized according to the BI-RAD System, 4th edition, which was established by the American College of Radiology (ACR). All the lesions were diagnosed by a histopathological analysis after mammographically guided wire-localization biopsy.RESULTS The 174 localizations yielded 125 (71.8%) benign lesions and 49 (28.2%) cancers, including 14 (28.6%) ductal carcinomas in situ and 35 (71.4%) invasive cancers. The overall positive predictive value (PPV)for cancer was 28.2% (49/174). After categorization according to the BI-RAD System, there were 12 category 2, 59 category 3, 83 category 4 and 20 category 5 lesions. The PPV for cancer for each category were 0% (0of 12 lesions) in category 2, 3.4% (2 of 59 lesions) in category 3, 37.3%(31 of 83 lesions) in category 4 and 80.0% (16 of 20 lesions) in category 5.CONCLUSION It is concluded that BI-RADS is valuable for the categorization of nonpalpable breast lesions in our Chinese popuiation. This system greatly improved the diagnostic specificity of nonpalpable breast lesions and was feasible in aiding decision-making for biopsy. It is suggested that nonpalpable breast lesions in categories BI-RADS 4 and 5should receive a biopsy because these lesions have a moderate and high positive predictive value for cancer.

  18. DNA damage, RAD9 and fertility/infertility of Echinococcus granulosus hydatid cysts.

    Science.gov (United States)

    Cabrera, Gonzalo; Cabrejos, María Eugenia; Morassutti, Alessandra Loureiro; Cabezón, Carolina; Orellana, Juana; Hellman, Ulf; Zaha, Arnaldo; Galanti, Norbel

    2008-08-01

    Hydatidosis, caused by the larval stage of the platyhelminth parasite Echinococcus granulosus, affects human and animal health. Hydatid fertile cysts are formed in intermediate hosts (human and herbivores) producing protoscoleces, the infective form to canines, at their germinal layers. Infertile cysts are also formed, but they are unable to produce protoscoleces. The molecular mechanisms involved in hydatid cysts fertility/infertility are unknown. Nevertheless, previous work from our laboratory has suggested that apoptosis is involved in hydatid cyst infertility and death. On the other hand, fertile hydatid cysts can resist oxidative damage due to reactive oxygen and nitrogen species. On these foundations, we have postulated that when oxidative damage of DNA in the germinal layers exceeds the capability of DNA repair mechanisms, apoptosis is triggered and hydatid cysts infertility occurs. We describe a much higher percentage of nuclei with oxidative DNA damage in dead protoscoleces and in the germinal layer of infertile cysts than in fertile cysts, suggesting that DNA repair mechanisms are active in fertile cysts. rad9, a conserved gene, plays a key role in cell cycle checkpoint modulation and DNA repair. We found that RAD9 of E. granulosus (EgRAD9) is expressed at the mRNA and protein levels. As it was found in other eukaryotes, EgRAD9 is hyperphosphorylated in response to DNA damage. Our results suggest that molecules involved in DNA repair in the germinal layer of fertile hydatid cysts and in protoscoleces, such as EgRAD9, may allow preserving the fertility of hydatid cysts in the presence of ROS and RNS.

  19. Functional connection between Rad51 and PML in homology-directed repair.

    Directory of Open Access Journals (Sweden)

    Sergei Boichuk

    Full Text Available The promyelocytic leukemia protein (PML is a tumor suppressor critical for formation of nuclear bodies (NBs performing important functions in transcription, apoptosis, DNA repair and antiviral responses. Earlier studies demonstrated that simian virus 40 (SV40 initiates replication near PML NBs. Here we show that PML knockdown inhibits viral replication in vivo, thus indicating a positive role of PML early in infection. SV40 large T antigen (LT induces DNA damage and, consequently, nuclear foci of the key homologous recombination repair protein Rad51 that colocalize with PML. PML depletion abrogates LT-induced Rad51 foci. LT may target PML NBs to gain access to DNA repair factors like Rad51 that are required for viral replication. We have used the SV40 model to gain insight to DNA repair events involving PML. Strikingly, even in normal cells devoid of viral oncoproteins, PML is found to be instrumental for foci of Rad51, Mre11 and BRCA1, as well as homology-directed repair after double-strand break (DSB induction. Following LT expression or external DNA damage, PML associates with Rad51. PML depletion also causes a loss of RPA foci following γ-irradiation, suggesting that PML is required for processing of DSBs. Immunofluorescent detection of incorporated BrdU without prior denaturation indicates a failure to generate ssDNA foci in PML knockdown cells upon γ-irradiation. Consistent with the lack of RPA and BrdU foci, γ-irradiation fails to induce Chk1 activation, when PML is depleted. Taken together, we have discovered a novel functional connection between PML and the homologous recombination-mediated repair machinery, which might contribute to PML tumor suppressor activity.

  20. DNA replication checkpoint signaling depends on a Rad53-Dbf4 N-terminal interaction in Saccharomyces cerevisiae.

    Science.gov (United States)

    Chen, Ying-Chou; Kenworthy, Jessica; Gabrielse, Carrie; Hänni, Christine; Zegerman, Philip; Weinreich, Michael

    2013-06-01

    Dbf4-dependent kinase (DDK) and cyclin-dependent kinase (CDK) are essential to initiate DNA replication at individual origins. During replication stress, the S-phase checkpoint inhibits the DDK- and CDK-dependent activation of late replication origins. Rad53 kinase is a central effector of the replication checkpoint and both binds to and phosphorylates Dbf4 to prevent late-origin firing. The molecular basis for the Rad53-Dbf4 physical interaction is not clear but occurs through the Dbf4 N terminus. Here we found that both Rad53 FHA1 and FHA2 domains, which specifically recognize phospho-threonine (pT), interacted with Dbf4 through an N-terminal sequence and an adjacent BRCT domain. Purified Rad53 FHA1 domain (but not FHA2) bound to a pT Dbf4 peptide in vitro, suggesting a possible phospho-threonine-dependent interaction between FHA1 and Dbf4. The Dbf4-Rad53 interaction is governed by multiple contacts that are separable from the Cdc5- and Msa1-binding sites in the Dbf4 N terminus. Importantly, abrogation of the Rad53-Dbf4 physical interaction blocked Dbf4 phosphorylation and allowed late-origin firing during replication checkpoint activation. This indicated that Rad53 must stably bind to Dbf4 to regulate its activity.

  1. The 12p13.33/RAD52 locus and genetic susceptibility to squamous cell cancers of upper aerodigestive tract.

    Directory of Open Access Journals (Sweden)

    Manon Delahaye-Sourdeix

    Full Text Available Genetic variants located within the 12p13.33/RAD52 locus have been associated with lung squamous cell carcinoma (LUSC. Here, within 5,947 UADT cancers and 7,789 controls from 9 different studies, we found rs10849605, a common intronic variant in RAD52, to be also associated with upper aerodigestive tract (UADT squamous cell carcinoma cases (OR = 1.09, 95% CI: 1.04-1.15, p = 6x10(-4. We additionally identified rs10849605 as a RAD52 cis-eQTL inUADT(p = 1x10(-3 and LUSC (p = 9x10(-4 tumours, with the UADT/LUSC risk allele correlated with increased RAD52 expression levels. The 12p13.33 locus, encompassing rs10849605/RAD52, was identified as a significant somatic focal copy number amplification in UADT(n = 374, q-value = 0.075 and LUSC (n = 464, q-value = 0.007 tumors and correlated with higher RAD52 tumor expression levels (p = 6x10(-48 and p = 3x10(-29 in UADT and LUSC, respectively. In combination, these results implicate increased RAD52 expression in both genetic susceptibility and tumorigenesis of UADT and LUSC tumors.

  2. Combined therapy with RAD001 e BEZ235 overcomes resistance of PET immortalized cell lines to mTOR inhibition.

    Science.gov (United States)

    Passacantilli, Ilaria; Capurso, Gabriele; Archibugi, Livia; Calabretta, Sara; Caldarola, Sara; Loreni, Fabrizio; Delle Fave, Gianfranco; Sette, Claudio

    2014-07-30

    Pancreatic endocrine tumors (PETs) are characterised by an indolent behaviour in terms of tumor growth. However, most patients display metastasis at diagnosis and no cure is currently available. Since the PI3K/AKT/mTOR axis is deregulated in PETs, the mTOR inhibitor RAD001 represents the first line treatment. Nevertheless, some patients do not respond to treatments and most acquire resistance. Inhibition of mTOR leads to feedback re-activation of PI3K activity, which may promote resistance to RAD001. Thus, PI3K represents a novel potential target for PETs. We tested the impact of three novel PI3K inhibitors (BEZ235, BKM120 and BYL719) on proliferation of PET cells that are responsive (BON-1) or unresponsive (QGP-1) to RAD001. BEZ235 was the most efficient in inhibiting proliferation in PET cells. Furthermore, combined treatment with BEZ235 and RAD001 exhibited synergic effects and was also effective in BON-1 that acquired resistance to RAD001 (BON-1 RR). Analysis of PI3K/AKT/mTOR pathway showed that RAD001 and BEZ235 only partially inhibited mTOR-dependent phosphorylation of 4EBP1. By contrast, combined therapy with the two inhibitors strongly inhibited phosphorylation of 4EBP1, assembly of the translational initiation complex and protein synthesis. Thus, combined treatment with BEZ235 may represent suitable therapy to counteract primary and acquired resistance to RAD001 in PETs.

  3. The pol3-t Hyperrecombination Phenotype and DNA Damage-Induced Recombination in Saccharomyces cerevisiae Is RAD50 Dependent

    Directory of Open Access Journals (Sweden)

    Alvaro Galli

    2009-01-01

    Full Text Available The DNA polymerase δ (POL3/CDC2 allele pol3-t of Saccharomyces cerevisiae has previously been shown to be sensitive to methylmethanesulfonate (MMS and has been proposed to be involved in base excision repair. Our results, however, show that the pol3-t mutation is synergistic for MMS sensitivity with MAG1, a known base excision repair gene, but it is epistatic with rad50Δ, suggesting that POL3 may be involved not only in base excision repair but also in a RAD50 dependent function. We further studied the interaction of pol3-t with rad50Δ by examining their effect on spontaneous, MMS-, UV-, and ionizing radiation-induced intrachromosomal recombination. We found that rad50Δ completely abolishes the elevated spontaneous frequency of intrachromosomal recombination in the pol3-t mutant and significantly decreases UV- and MMS-induced recombination in both POL3 and pol3-t strains. Interestingly, rad50Δ had no effect on γ-ray-induced recombination in both backgrounds between 0 and 50 Gy. Finally, the deletion of RAD50 had no effect on the elevated frequency of homologous integration conferred by the pol3-t mutation. RAD50 is possibly involved in resolution of replication forks that are stalled by mutagen-induced external DNA damage, or internal DNA damage produced by growing the pol3-t mutant at the restrictive temperature.

  4. Nascent DNA synthesis during homologous recombination is synergistically promoted by the rad51 recombinase and DNA homology.

    Science.gov (United States)

    Mundia, Maureen M; Desai, Vatsal; Magwood, Alissa C; Baker, Mark D

    2014-05-01

    In this study, we exploited a plasmid-based assay that detects the new DNA synthesis (3' extension) that accompanies Rad51-mediated homology searching and strand invasion steps of homologous recombination to investigate the interplay between Rad51 concentration and homology length. Mouse hybridoma cells that express endogenous levels of Rad51 display an approximate linear increase in the frequency of 3' extension for homology lengths of 500 bp to 2 kb. At values below ∼500 bp, the frequency of 3' extension declines markedly, suggesting that this might represent the minimal efficient processing segment for 3' extension. Overexpression of wild-type Rad51 stimulated the frequency of 3' extension by ∼3-fold for homology lengths homology was >2 kb, 3' extension frequency increased by as much as 10-fold. Excess wild-type Rad51 did not increase the average 3' extension tract length. Analysis of cell lines expressing N-terminally FLAG-tagged Rad51 polymerization mutants F86E, A89E, or F86E/A89E established that the 3' extension process requires Rad51 polymerization activity. Mouse hybridoma cells that have reduced Brca2 (Breast cancer susceptibility 2) due to stable expression of small interfering RNA show a significant reduction in 3' extension efficiency; expression of wild-type human BRCA2, but not a BRCA2 variant devoid of BRC repeats 1-8, rescues the 3' extension defect in these cells. Our results suggest that increased Rad51 concentration and homology length interact synergistically to promote 3' extension, presumably as a result of enhanced Brca2-mediated Rad51 polymerization.

  5. Differential repair of UV damage in rad mutants of Saccharomyces cerevisiae: a possible function of G2 arrest upon UV irradiation.

    Science.gov (United States)

    Terleth, C; Schenk, P; Poot, R; Brouwer, J; van de Putte, P

    1990-09-01

    After UV irradiation, the transcriptionally active MAT alpha locus in Saccharomyces cerevisiae is preferentially repaired compared with the inactive HML alpha locus. The effect of rad mutations from three different epistasis groups on differential repair was investigated. Three mutants, rad9, rad16, and rad24, were impaired in the removal of UV dimers from the inactive HML alpha locus, whereas they had generally normal repair of the active MAT alpha locus. Since RAD9 is necessary for G2 arrest after UV irradiation, we propose that the G2 stage plays a role in making the dimers accessible for repair, at least in the repressed HML alpha locus.

  6. Chl12 (Ctf18) Forms a Novel Replication Factor C-Related Complex and Functions Redundantly with Rad24 in the DNA Replication Checkpoint Pathway

    OpenAIRE

    Naiki, Takahiro; Kondo, Tae; Nakada, Daisuke; Matsumoto, Kunihiro; Sugimoto, Katsunori

    2001-01-01

    RAD24 has been identified as a gene essential for the DNA damage checkpoint in budding yeast. Rad24 is structurally related to subunits of the replication factor C (RFC) complex, and forms an RFC-related complex with Rfc2, Rfc3, Rfc4, and Rfc5. The rad24Δ mutation enhances the defect of rfc5-1 in the DNA replication block checkpoint, implicating RAD24 in this checkpoint. CHL12 (also called CTF18) encodes a protein that is structurally related to the Rad24 and RFC proteins. We show here that a...

  7. The PCNA interaction protein box sequence in Rad54 is an integral part of its ATPase domain and is required for efficient DNA repair and recombination

    DEFF Research Database (Denmark)

    Burgess, Rebecca C; Sebesta, Marek; Sisakova, Alexandra

    2013-01-01

    Rad54 is an ATP-driven translocase involved in the genome maintenance pathway of homologous recombination (HR). Although its activity has been implicated in several steps of HR, its exact role(s) at each step are still not fully understood. We have identified a new interaction between Rad54...... and the replicative DNA clamp, proliferating cell nuclear antigen (PCNA). This interaction was only mildly weakened by the mutation of two key hydrophobic residues in the highly-conserved PCNA interaction motif (PIP-box) of Rad54 (Rad54-AA). Intriguingly, the rad54-AA mutant cells displayed sensitivity to DNA damage...

  8. Radón y sus efectos en la salud en trabajadores de minas de uranio

    Directory of Open Access Journals (Sweden)

    Gonzalo Aicardi-Carrillo

    2015-03-01

    Full Text Available Introducción: El radón es un gas presente en subsuelo, especialmente en minas de uranio, que produce consecuencias sobre la salud, entre las que destaca el cáncer de pulmón. En EEUU es la segunda causa de mortalidad por esta enfermedad. Pese a la fuerte relación causal no existe normativa específica europea de regulación en mineros. Objetivos: Identificar el efecto del radón y sus derivados sobre la salud de los trabajadores de minas de uranio; describir la asociación entre exposición a radón y a otros minerales sobre la salud y asociación entre radón y consumo de tabaco. Metodología: Realizamos una revisión bibliográfica de literatura publicada entre 2007 y 2014, en bases de datos biomédicas, utilizando los criterios de inclusión y exclusión previamente establecidos. Resultados: Se revisan 32 artículos, encontrando un aumento significativo de cáncer pulmonar (SMR-2.03, IC95% 1.96-2.10, incluso a dosis bajas (300-WLM así como otros cánceres (laringe, gástrico, hepático y leucemia y enfermedades cerebrovasculares, controlando posibles factores de confusión (tabaco, silicosis, cuarzo y arsénico no encontrando relación significativa ni sinergias. Conclusión: Existe asociación entre la exposición al radón y cáncer pulmonar en minas de uranio, con un periodo medio de latencia de 20 años, determinado por la dosis de radón y el tiempo de exposición. No se ha demostrado riesgo de desarrollar otros tipos de tumores, y los estudios que lo sugieren son poco consistentes.

  9. Small-molecule inhibitors identify the RAD52-ssDNA interaction as critical for recovery from replication stress and for survival of BRCA2 deficient cells

    Science.gov (United States)

    Hengel, Sarah R; Malacaria, Eva; Folly da Silva Constantino, Laura; Bain, Fletcher E; Diaz, Andrea; Koch, Brandon G; Yu, Liping; Wu, Meng; Pichierri, Pietro; Spies, M Ashley; Spies, Maria

    2016-01-01

    The DNA repair protein RAD52 is an emerging therapeutic target of high importance for BRCA-deficient tumors. Depletion of RAD52 is synthetically lethal with defects in tumor suppressors BRCA1, BRCA2 and PALB2. RAD52 also participates in the recovery of the stalled replication forks. Anticipating that ssDNA binding activity underlies the RAD52 cellular functions, we carried out a high throughput screening campaign to identify compounds that disrupt the RAD52-ssDNA interaction. Lead compounds were confirmed as RAD52 inhibitors in biochemical assays. Computational analysis predicted that these inhibitors bind within the ssDNA-binding groove of the RAD52 oligomeric ring. The nature of the inhibitor-RAD52 complex was validated through an in silico screening campaign, culminating in the discovery of an additional RAD52 inhibitor. Cellular studies with our inhibitors showed that the RAD52-ssDNA interaction enables its function at stalled replication forks, and that the inhibition of RAD52-ssDNA binding acts additively with BRCA2 or MUS81 depletion in cell killing. DOI: http://dx.doi.org/10.7554/eLife.14740.001 PMID:27434671

  10. Rice OsRAD21-2 is Expressed in Actively Dividing Tissues and its Ectopic Expression in Yeast Results in Aberrant Cell Division and Growth

    Institute of Scientific and Technical Information of China (English)

    Chunyan Gong; Tang Li; Qi Li; Longfeng Yan; Tai Wang

    2011-01-01

    Rad21 and its meiotic counterpart Rec8,the key components of the cohesin complex,are essential for sister chromatid cohesion and chromosome segregation in mitosis and meiosis,respectively.In contrast to yeast and vertebrates,which have only two RAD21/REC8 genes,the rice genome encodes four Rad21/Rec8 proteins.Here,we report on the cloning and characterization of OsRAD21-2 from rice (Oryza sativa L.).Phylogenetic analysis of the full-length amino acids showed that OsRad21-2 was grouped into the plant-specific Rad21 subfamily.Semi-quantitative reverse transcription-polymerase chain reaction revealed OsRAD21-2 preferentially expressed in premeiotic flowers.Further RNA in situ hybridization analysis and promoter::β-glucuronidase staining indicated that OsRAD21-2 was mainly expressed in actively dividing tissues including premeiotic stamen,stem intercalary meristem,leaf meristem,and root pericycle.Ectopic expression of OsRAD21-2 in fission yeast resulted in cell growth delay and morphological abnormality.Flow cytometric analysis revealed that the OsRAD21-2-expressed cells were arrested in G2 phase.Our results suggest that OsRad21-2 functions in regulation of cell division and growth.

  11. Transcript levels of the Saccharomyes cerevisiae DNA repair gene RAD23 increase in response to UV light and in meiosis but remain constant in the mitotic cell cycle.

    Science.gov (United States)

    Madura, K; Prakash, S

    1990-08-25

    The RAD23 gene of Saccharomyces cerevisiae is required for excision-repair of UV damaged DNA. In this paper, we determine the location of the RAD23 gene in a cloned DNA fragment, identify the 1.6 kb RAD23 transcript, and examine RAD23 transcript levels in UV damaged cells, during the mitotic cell cycle, and in meiosis. The RAD23 mRNA levels are elevated 5-fold between 30 to 60 min after 37 J/m2 of UV light. RAD23 mRNA levels rise over 6-fold during meiosis at a stage coincident with high levels of genetic recombination. This response is specific to sporulation competent MATa/MAT alpha diploid cells, and is not observed in asporogenous MATa/MATa diploids. RAD23 mRNA levels, however, remain constant during the mitotic cell cycle.

  12. Acurácia dos achados mamográficos do câncer de mama: correlação da classificação BI-RADS e achados histológicos Accuracy of mammographic findings in breast cancer: correlation between BI-RADS classification and histological findings

    Directory of Open Access Journals (Sweden)

    José Hermes Ribas do Nascimento

    2010-04-01

    BI-RADS accuracy in mammography was evaluated. The interobserver agreement was analyzed with the Cohen's kappa (κ test, and the differences between groups were evaluated with the chi-squared test. RESULTS: The present study demonstrated that the mammographic accuracy ranged from 75% to 62% in the differentiation between benign and malignant lesions with the utilization of the BI-RADS classification. Statistically significant interobserver agreement was observed in the description of masses margins (κ= 0.66. A low agreement rate was identified in the description of masses borders (shape (κ= 0.40 and calcifications, both in relation to their distribution (κ= 0.24 and morphology (κ= 0.36. CONCLUSION: The present study demonstrated the BI-RADS accuracy in the differentiation between benign and malignant lesions. The interobserver agreement was poor in the analysis of calcifications morphology and distribution, but a progressive increase in the positive predictive values was observed in the subcategory 4.

  13. Fast neutron background characterization with the Radiological Multi-sensor Analysis Platform (RadMAP)

    CERN Document Server

    Davis, John R; Vetter, Kai

    2016-01-01

    In an effort to characterize the fast neutron radiation background, 16 EJ-309 liquid scintillator cells were installed in the Radiological Multi-sensor Analysis Platform (RadMAP) to collect data in the San Francisco Bay Area. Each fast neutron event was associated with specific weather metrics (pressure, temperature, absolute humidity) and GPS coordinates. The expected exponential dependence of the fast neutron count rate on atmospheric pressure was demonstrated and event rates were subsequently adjusted given the measured pressure at the time of detection. Pressure adjusted data was also used to investigate the influence of other environmental conditions on the neutron background rate. Using National Oceanic and Atmospheric Administration (NOAA) coastal area lidar data, an algorithm was implemented to approximate sky-view factors (the total fraction of visible sky) for points along RadMAPs route. Three areas analyzed in San Francisco, Downtown Oakland, and Berkeley all demonstrated a suppression in the backg...

  14. Autophagy inhibition enhances RAD001-induced cytotoxicity in human bladder cancer cells

    Directory of Open Access Journals (Sweden)

    Lin JF

    2016-04-01

    Full Text Available Ji-Fan Lin,1 Yi-Chia Lin,2,3 Shan-Che Yang,1 Te-Fu Tsai,2,3 Hung-En Chen,2 Kuang-Yu Chou,2,3 Thomas I-Sheng Hwang2–4 1Central Laboratory, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan; 2Division of Urology, Department of Surgery, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan; 3Division of Urology, School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan; 4Department of Urology, Taipei Medical University, Taipei, Taiwan Background: Mammalian target of rapamycin (mTOR, involved in PI3K/AKT/mTOR pathway, is known to play a central role in regulating the growth of cancer cells. The PI3K/AKT/mTOR pathway enhances tumor survival and proliferation through suppressing autophagy, which sustains energy homeostasis by collecting and recycling cellular components under stress conditions. Conversely, inhibitors of the mTOR pathway such as RAD001 induce autophagy, leading to promotion of tumor survival and limited antitumor efficacy. We thus hypothesized that the use of autophagy inhibitor in combination with mTOR inhibition improves the cytotoxicity of mTOR inhibitors in bladder cancer.Materials and methods: The cytotoxicity of RT4, 5637, HT1376, and T24 human bladder cancer cells treated with RAD001 alone or combined with autophagy inhibitors (3-methyladenine (3-MA, bafilomycin A1 (Baf A1, chloroquine, or hydroxychloroquine was assessed using the WST-8 cell viability kit. The autophagy status in cells was analyzed by the detection of microtubule-associated light chain 3 form II (LC3-II, using immunofluorescent staining and Western blot. Acidic vesicular organelle (AVO formation in treated cells was determined by acridine orange vital staining. Inhibition of mTOR pathway by RAD001 was monitored by using a homemade quantitative polymerase chain reaction gene array, while phospho-mTOR was detected using Western blot. Induced apoptosis was determined by measurement of caspase 3/7 activity and DNA fragmentation in cells after

  15. Co-design of RAD and ETHICS methodologies: a combination of information system development methods

    Science.gov (United States)

    Nasehi, Arezo; Shahriyari, Salman

    2011-12-01

    Co-design is a new trend in the social world which tries to capture different ideas in order to use the most appropriate features for a system. In this paper, co-design of two information system methodologies is regarded; rapid application development (RAD) and effective technical and human implementation of computer-based systems (ETHICS). We tried to consider the characteristics of these methodologies to see the possibility of having a co-design or combination of them for developing an information system. To reach this purpose, four different aspects of them are analyzed: social or technical approach, user participation and user involvement, job satisfaction, and overcoming change resistance. Finally, a case study using the quantitative method is analyzed in order to examine the possibility of co-design using these factors. The paper concludes that RAD and ETHICS are appropriate to be co-designed and brings some suggestions for the co-design.

  16. ATP-dependent DNA binding, unwinding, and resection by the Mre11/Rad50 complex.

    Science.gov (United States)

    Liu, Yaqi; Sung, Sihyun; Kim, Youngran; Li, Fuyang; Gwon, Gwanghyun; Jo, Aera; Kim, Ae-Kyoung; Kim, Taeyoon; Song, Ok-Kyu; Lee, Sang Eun; Cho, Yunje

    2016-04-01

    ATP-dependent DNA end recognition and nucleolytic processing are central functions of the Mre11/Rad50 (MR) complex in DNA double-strand break repair. However, it is still unclear how ATP binding and hydrolysis primes the MR function and regulates repair pathway choice in cells. Here,Methanococcus jannaschii MR-ATPγS-DNA structure reveals that the partly deformed DNA runs symmetrically across central groove between two ATPγS-bound Rad50 nucleotide-binding domains. Duplex DNA cannot access the Mre11 active site in the ATP-free full-length MR complex. ATP hydrolysis drives rotation of the nucleotide-binding domain and induces the DNA melting so that the substrate DNA can access Mre11. Our findings suggest that the ATP hydrolysis-driven conformational changes in both DNA and the MR complex coordinate the melting and endonuclease activity.

  17. Updates from the MSL-RAD Experiment on the Mars Curiosity Rover

    Science.gov (United States)

    Zeitlin, Cary

    2015-01-01

    The MSL-RAD instrument continues to operate flawlessly on Mars. As of this writing, some 1040 sols (Martian days) of data have been successfully acquired. Several improvements have been made to the instrument's configuration, particularly aimed at enabling the analysis of neutral-particle data. The dose rate since MSL's landing in August 2012 has remained remarkably stable, reflecting the unusual and very weak solar maximum of Cycle 24. Only a few small SEP events have been observed by RAD, which is shielded by the Martian atmosphere. Gale Crater, where Curiosity landed, is 4.4 km below the mean surface of Mars, and the column depth of atmosphere above is approximately 20 g/sq cm, which provides significant attenuation of GCR heavy ions and SEPs. Recent analysis results will be presented, including updated estimates of the neutron contributions to dose and dose equivalent in cruise and on the surface of Mars.

  18. RAD tag sequencing as a source of SNP markers in Cynara cardunculus L

    Directory of Open Access Journals (Sweden)

    Scaglione Davide

    2012-01-01

    Full Text Available Abstract Background The globe artichoke (Cynara cardunculus L. var. scolymus genome is relatively poorly explored, especially compared to those of the other major Asteraceae crops sunflower and lettuce. No SNP markers are in the public domain. We have combined the recently developed restriction-site associated DNA (RAD approach with the Illumina DNA sequencing platform to effect the rapid and mass discovery of SNP markers for C. cardunculus. Results RAD tags were sequenced from the genomic DNA of three C. cardunculus mapping population parents, generating 9.7 million reads, corresponding to ~1 Gbp of sequence. An assembly based on paired ends produced ~6.0 Mbp of genomic sequence, separated into ~19,000 contigs (mean length 312 bp, of which ~21% were fragments of putative coding sequence. The shared sequences allowed for the discovery of ~34,000 SNPs and nearly 800 indels, equivalent to a SNP frequency of 5.6 per 1,000 nt, and an indel frequency of 0.2 per 1,000 nt. A sample of heterozygous SNP loci was mapped by CAPS assays and this exercise provided validation of our mining criteria. The repetitive fraction of the genome had a high representation of retrotransposon sequence, followed by simple repeats, AT-low complexity regions and mobile DNA elements. The genomic k-mers distribution and CpG rate of C. cardunculus, compared with data derived from three whole genome-sequenced dicots species, provided a further evidence of the random representation of the C. cardunculus genome generated by RAD sampling. Conclusion The RAD tag sequencing approach is a cost-effective and rapid method to develop SNP markers in a highly heterozygous species. Our approach permitted to generate a large and robust SNP datasets by the adoption of optimized filtering criteria.

  19. Unligated Okazaki Fragments Induce PCNA Ubiquitination and a Requirement for Rad59-Dependent Replication Fork Progression.

    Directory of Open Access Journals (Sweden)

    Hai Dang Nguyen

    Full Text Available Deficiency in DNA ligase I, encoded by CDC9 in budding yeast, leads to the accumulation of unligated Okazaki fragments and triggers PCNA ubiquitination at a non-canonical lysine residue. This signal is crucial to activate the S phase checkpoint, which promotes cell cycle delay. We report here that a pol30-K107 mutation alleviated cell cycle delay in cdc9 mutants, consistent with the idea that the modification of PCNA at K107 affects the rate of DNA synthesis at replication forks. To determine whether PCNA ubiquitination occurred in response to nicks or was triggered by the lack of PCNA-DNA ligase interaction, we complemented cdc9 cells with either wild-type DNA ligase I or a mutant form, which fails to interact with PCNA. Both enzymes reversed PCNA ubiquitination, arguing that the modification is likely an integral part of a novel nick-sensory mechanism and not due to non-specific secondary mutations that could have occurred spontaneously in cdc9 mutants. To further understand how cells cope with the accumulation of nicks during DNA replication, we utilized cdc9-1 in a genome-wide synthetic lethality screen, which identified RAD59 as a strong negative interactor. In comparison to cdc9 single mutants, cdc9 rad59Δ double mutants did not alter PCNA ubiquitination but enhanced phosphorylation of the mediator of the replication checkpoint, Mrc1. Since Mrc1 resides at the replication fork and is phosphorylated in response to fork stalling, these results indicate that Rad59 alleviates nick-induced replication fork slowdown. Thus, we propose that Rad59 promotes fork progression when Okazaki fragment processing is compromised and counteracts PCNA-K107 mediated cell cycle arrest.

  20. Online measurement of the BEPC Ⅱ background using RadFET dosimeters

    Institute of Scientific and Technical Information of China (English)

    GONG Hui; LI Jin; GONG Guang-Hua; LI Yu-Xiong; HOU Lei; SHAO Bei-Bei

    2009-01-01

    To monitor the integral dose deposited in the BESⅢ electromagnetic calorimeter whose perfor-mance degrades due to exposure to the BEPCⅡ background, a 400 nm IMPL RadFET dosimeter-based integral dose online monitor system is built. After calibration with the 60Co source and verification with TLD in the pulse radiation fields, an experiment was arranged to measure the BEPC Ⅱ background online. The results are presented.

  1. Application of RAD-BCG calculator to Hanford's 300 area shoreline characterization dataset

    Energy Technology Data Exchange (ETDEWEB)

    Antonio, Ernest J.; Poston, Ted M.; Tiller, Brett L.; Patton, Gene W.

    2003-07-01

    Abstract. In 2001, a multi-agency study was conducted to characterize potential environmental effects from radiological and chemical contaminants on the near-shore environment of the Columbia River at the 300 Area of the U.S. Department of Energy’s Hanford Site. Historically, the 300 Area was the location of nuclear fuel fabrication and was the main location for research and development activities from the 1940s until the late 1980s. During past waste handling practices uranium, copper, and other heavy metals were routed to liquid waste streams and ponds near the Columbia River shoreline. The Washington State Department of Health and the Pacific Northwest National Laboratory’s Surface Environmental Surveillance Project sampled various environmental components including river water, riverbank spring water, sediment, fishes, crustaceans, bivalve mollusks, aquatic insects, riparian vegetation, small mammals, and terrestrial invertebrates for analyses of radiological and chemical constituents. The radiological analysis results for water and sediment were used as initial input into the RAD-BCG Calculator. The RAD-BCG Calculator, a computer program that uses an Excel® spreadsheet and Visual Basic® software, showed that maximum radionuclide concentrations measured in water and sediment were lower than the initial screening criteria for concentrations to produce dose rates at existing or proposed limits. Radionuclide concentrations measured in biota samples were used to calculate site-specific bioaccumulation coefficients (Biv) to test the utility of the RAD-BCG-Calculator’s site-specific screening phase. To further evaluate site-specific effects, the default Relative Biological Effect (RBE) for internal alpha particle emissions was reduced by half and the program’s kinetic/allometric calculation approach was initiated. The subsequent calculations showed the initial RAD-BCG Calculator results to be conservative, which is appropriate for screening purposes.

  2. Relation between radiographic BI-RADS scores and triple negativity in patients with ductal carcinomas

    OpenAIRE

    OKTAY, Murat; Oktay, Nilay Aydın; Besir, Fahri Halit; Buyukkaya, Ramazan; Erdem, Havva; Binnur ÖNAL; Ozaydın, İsmet; Yazıcı, Burhan

    2014-01-01

    The aim of this study was to investigate association of radiographic (BI-RADS 4 and 5) results and prognostic factors of invasive ductal carcinomas with their histopathological subtypes. A total of 103 patients histopathologically diagnosed with invasive ductal carcinoma of breast with in last five years period were enrolled. Of them, 69 patients who had radiological reports in were included from registry of Radiology Department; Duzce University Training and Research Hospital archives. BI-RA...

  3. Rad-Tolerant, Thermally Stable, High-Speed Fiber-Optic Network for Harsh Environments

    Science.gov (United States)

    Leftwich, Matt; Hull, Tony; Leary, Michael; Leftwich, Marcus

    2013-01-01

    Future NASA destinations will be challenging to get to, have extreme environmental conditions, and may present difficulty in retrieving a spacecraft or its data. Space Photonics is developing a radiation-tolerant (rad-tolerant), high-speed, multi-channel fiber-optic transceiver, associated reconfigurable intelligent node communications architecture, and supporting hardware for intravehicular and ground-based optical networking applications. Data rates approaching 3.2 Gbps per channel will be achieved.

  4. Relation between radiographic BI-RADS scores and triple negativity in patients with ductal carcinomas

    OpenAIRE

    OKTAY, Murat; Oktay, Nilay Aydın; Besir, Fahri Halit; Buyukkaya, Ramazan; Erdem, Havva; ÖNAL, Binnur; Ozaydın, İsmet; Yazıcı, Burhan

    2014-01-01

    The aim of this study was to investigate association of radiographic (BI-RADS 4 and 5) results and prognostic factors of invasive ductal carcinomas with their histopathological subtypes. A total of 103 patients histopathologically diagnosed with invasive ductal carcinoma of breast with in last five years period were enrolled. Of them, 69 patients who had radiological reports in were included from registry of Radiology Department; Duzce University Training and Research Hospital archives. BI-RA...

  5. Diagnostic value of BI-RADS categories in the management of patients with benign breast pathology

    Directory of Open Access Journals (Sweden)

    G. P. Korzhenkova

    2016-01-01

    Full Text Available Reasonable tactics of management of the patients with breast disease depends of the quality of diagnostics methods. Modern requirements to the methods of diagnosis – a precision, high information value, accessibility. In the article BI-RADS (Breast Imaging Reporting and Data System is being discussed. This system is a good tool to determine the proper algorithm of breast disease patients’ management.

  6. Mapping Institution-Specific Study Descriptions to RadLex Playbook Entries

    OpenAIRE

    Mabotuwana, Thusitha; Lee, Michael C.; Cohen-Solal, Eric V.; Chang, Paul

    2014-01-01

    The naming of imaging procedures is currently not standardized across institutions. As a result, it is a challenge to establish national registries, for instance, a national registry of dose to facilitate comparisons among different types of CT procedures. RSNA’s RadLex Playbook is an effort towards addressing this gap (by introducing a unique Playbook identifier called an RPID for each procedure), and the current research focuses on semi-automatically mapping institution-specific procedure d...

  7. Rad51 and BRCA2--New molecular targets for sensitizing glioma cells to alkylating anticancer drugs.

    Directory of Open Access Journals (Sweden)

    Steve Quiros

    Full Text Available First line chemotherapeutics for brain tumors (malignant gliomas are alkylating agents such as temozolomide and nimustine. Despite growing knowledge of how these agents work, patients suffering from this malignancy still face a dismal prognosis. Alkylating agents target DNA, forming the killing lesion O(6-alkylguanine, which is converted into DNA double-strand breaks (DSBs that trigger apoptosis. Here we assessed whether inhibiting repair of DSBs by homologous recombination (HR or non-homologous end joining (NHEJ is a reasonable strategy for sensitizing glioma cells to alkylating agents. For down-regulation of HR in glioma cells, we used an interference RNA (iRNA approach targeting Rad51 and BRCA2, and for NHEJ we employed the DNA-PK inhibitor NU7026. We also assessed whether inhibition of poly(ADPribosyltransferase (PARP by olaparib would enhance the killing effect. The data show that knockdown of Rad51 or BRCA2 greatly sensitizes cells to DSBs and the induction of cell death following temozolomide and nimustine (ACNU. It did not sensitize to ionizing radiation (IR. The expression of O(6-methylguanine-DNA methyltransferase (MGMT abolished all these effects, indicating that O(6-alkylguanine induced by these drugs is the primary lesion responsible for the formation of DSBs and increased sensitivity of glioma cells following knockdown of Rad51 and BRCA2. Inhibition of DNA-PK only slightly sensitized to temozolomide whereas a significant effect was observed with IR. A triple strategy including siRNA and the PARP inhibitor olaparib further improved the killing effect of temozolomide. The data provides evidence that down-regulation of Rad51 or BRCA2 is a reasonable strategy for sensitizing glioma cells to killing by O(6-alkylating anti-cancer drugs. The data also provide proof of principle that a triple strategy involving down-regulation of HR, PARP inhibition and MGMT depletion may greatly enhance the therapeutic effect of temozolomide.

  8. A BI-RADS Based Expert Systems for the Diagnoses of Breast Diseases

    OpenAIRE

    U. K. Ngah; Aziz, S.A.; M. E. Aziz; Murad, M.; N. M.N. Mahdi

    2007-01-01

    We proposed an expert system based on the interpretation of mammographic and ultrasound images that may be used by expert and non-expert doctors in the interpretation and classifying of patient cases. The expert system software consists of a mammographic(MAMMEX) and breast ultrasound(SOUNDEX) medical expert systems which may be used to deduce cases according to the Breast Imaging Recording and Data System (BI-RADS) based upon patients history, physical and clinical assessment as well as mammo...

  9. Functional effects of diphosphomimetic mutations at cAbl-mediated phosphorylation sites on Rad51 recombinase activity.

    Science.gov (United States)

    Alligand, Brendan; Le Breton, Magali; Marquis, Damien; Vallette, François; Fleury, Fabrice

    2017-08-01

    Homologous Recombination enables faithful repair of the deleterious double strand breaks of DNA. This pathway relies on Rad51 to catalyze homologous DNA strand exchange. Rad51 is known to be phosphorylated in a sequential manner on Y315 and then on Y54, but the effect of such phosphorylation on Rad51 function remains poorly understood. We have developed a phosphomimetic model in order to study all the phosphorylation states. With the purified phosphomimetic proteins we performed in vitro assays to determine the activity of Rad51. Here we demonstrate the inhibitory effect of the double phosphomimetic mutant and suggest that it may be due to a defect in nucleofilament formation. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  10. The checkpoint clamp protein Rad9 facilitates DNA-end resection and prevents alternative non-homologous end joining.

    Science.gov (United States)

    Tsai, Feng-Ling; Kai, Mihoko

    2014-01-01

    DNA damage activates the cell cycle checkpoint to regulate cell cycle progression. The checkpoint clamp (Rad9-Hus1-Rad1 complex) is recruited to damage sites, and is required for checkpoint activation. While functions of the checkpoint clamp in checkpoint activation have been well studied, its functions in DNA repair regulation remain elusive. Here we show that Rad9 is required for efficient homologous recombination (HR), and facilitates DNA-end resection. The role of Rad9 in homologous recombination is independent of its function in checkpoint activation, and this function is important for preventing alternative non-homologous end joining (altNHEJ). These findings reveal novel function of the checkpoint clamp in HR.

  11. Diagnostic SNPs for inferring population structure in American mink (Neovison vison) identified through RAD sequencing

    DEFF Research Database (Denmark)

    2015-01-01

    Data from: "Diagnostic SNPs for inferring population structure in American mink (Neovison vison) identified through RAD sequencing" in Genomic Resources Notes accepted 1 October 2014 to 30 November 2014....

  12. Genetic Interactions Between the Meiosis-Specific Cohesin Components, STAG3, REC8, and RAD21L

    Directory of Open Access Journals (Sweden)

    Ayobami Ward

    2016-06-01

    Full Text Available Cohesin is an essential structural component of chromosomes that ensures accurate chromosome segregation during mitosis and meiosis. Previous studies have shown that there are cohesin complexes specific to meiosis, required to mediate homologous chromosome pairing, synapsis, recombination, and segregation. Meiosis-specific cohesin complexes consist of two structural maintenance of chromosomes proteins (SMC1α/SMC1β and SMC3, an α-kleisin protein (RAD21, RAD21L, or REC8, and a stromal antigen protein (STAG1, 2, or 3. STAG3 is exclusively expressed during meiosis, and is the predominant STAG protein component of cohesin complexes in primary spermatocytes from mouse, interacting directly with each α-kleisin subunit. REC8 and RAD21L are also meiosis-specific cohesin components. Stag3 mutant spermatocytes arrest in early prophase (“zygotene-like” stage, displaying failed homolog synapsis and persistent DNA damage, as a result of unstable loading of cohesin onto the chromosome axes. Interestingly, Rec8, Rad21L double mutants resulted in an earlier “leptotene-like” arrest, accompanied by complete absence of STAG3 loading. To assess genetic interactions between STAG3 and α-kleisin subunits RAD21L and REC8, our lab generated Stag3, Rad21L, and Stag3, Rec8 double knockout mice, and compared them to the Rec8, Rad21L double mutant. These double mutants are phenotypically distinct from one another, and more severe than each single knockout mutant with regards to chromosome axis formation, cohesin loading, and sister chromatid cohesion. The Stag3, Rad21L, and Stag3, Rec8 double mutants both progress further into prophase I than the Rec8, Rad21L double mutant. Our genetic analysis demonstrates that cohesins containing STAG3 and REC8 are the main complex required for centromeric cohesion, and RAD21L cohesins are required for normal clustering of pericentromeric heterochromatin. Furthermore, the STAG3/REC8 and STAG3/RAD21L cohesins are the primary

  13. RAD50 and NBS1 form a stable complex functional in DNA binding and tethering.

    Science.gov (United States)

    van der Linden, Eddy; Sanchez, Humberto; Kinoshita, Eri; Kanaar, Roland; Wyman, Claire

    2009-04-01

    The RAD50/MRE11/NBS1 protein complex (RMN) plays an essential role during the early steps of DNA double-strand break (DSB) repair by homologous recombination. Previous data suggest that one important role for RMN in DSB repair is to provide a link between DNA ends. The striking architecture of the complex, a globular domain from which two extended coiled coils protrude, is essential for this function. Due to its DNA-binding activity, ability to form dimers and interact with both RAD50 and NBS1, MRE11 is considered to be crucial for formation and function of RMN. Here, we show the successful expression and purification of a stable complex containing only RAD50 and NBS1 (RN). The characteristic architecture of the complex was not affected by absence of MRE11. Although MRE11 is a DNA-binding protein it was not required for DNA binding per se or DNA-tethering activity of the complex. The stoichiometry of NBS1 in RMN and RN complexes was estimated by SFM-based volume analysis. These data show that in vitro, R, M and N form a variety of stable complexes with variable subunit composition and stoichiometry, which may be physiologically relevant in different aspects of RMN function.

  14. A new e-learning platform for radiology education (RadEd).

    Science.gov (United States)

    Xiberta, Pau; Boada, Imma

    2016-04-01

    One of the key elements of e-learning platforms is the content provided to the students. Content creation is a time demanding task that requires teachers to prepare material taking into account that it will be accessed on-line. Moreover, the teacher is restricted by the functionalities provided by the e-learning platforms. In contexts such as radiology where images have a key role, the required functionalities are still more specific and difficult to be provided by these platforms. Our purpose is to create a framework to make teacher's tasks easier, specially when he has to deal with contents where images have a main role. In this paper, we present RadEd, a new web-based teaching framework that integrates a smart editor to create case-based exercises that support image interaction such as changing the window width and the grey scale used to render the image, taking measurements on the image, attaching labels to images and selecting parts of the images, amongst others. It also provides functionalities to prepare courses with different topics, exercises and theory material, and also functionalities to control students' work. Different experts have used RadEd and all of them have considered it a very useful and valuable tool to prepare courses where radiological images are the main component. RadEd provides teachers functionalities to prepare more realistic cases and students the ability to make a more specific diagnosis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. Uncertainty modeling for ontology-based mammography annotation with intelligent BI-RADS scoring.

    Science.gov (United States)

    Bulu, Hakan; Alpkocak, Adil; Balci, Pinar

    2013-05-01

    This paper presents an ontology-based annotation system and BI-RADS (Breast Imaging Reporting and Data System) score reasoning with Semantic Web technologies in mammography. The annotation system is based on the Mammography Annotation Ontology (MAO) where the BI-RADS score reasoning works. However, ontologies are based on crisp logic and they cannot handle uncertainty. Consequently, we propose a Bayesian-based approach to model uncertainty in mammography ontology and make reasoning possible using BI-RADS scores with SQWRL (Semantic Query-enhanced Web Rule Language). First, we give general information about our system and present details of mammography annotation ontology, its main concepts and relationships. Then, we express uncertainty in mammography and present approaches to handle uncertainty issues. System is evaluated with a manually annotated dataset DEMS (Dokuz Eylul University Mammography Set) and DDSM (Digital Database for Screening Mammography). We give the result of experimentations in terms of accuracy, sensitivity, precision and uncertainty level measures. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Conformational adaptability of Redbeta during DNA annealing and implications for its structural relationship with Rad52.

    Science.gov (United States)

    Erler, Axel; Wegmann, Susanne; Elie-Caille, Celine; Bradshaw, Charles Richard; Maresca, Marcello; Seidel, Ralf; Habermann, Bianca; Muller, Daniel J; Stewart, A Francis

    2009-08-21

    Single-strand annealing proteins, such as Redbeta from lambda phage or eukaryotic Rad52, play roles in homologous recombination. Here, we use atomic force microscopy to examine Redbeta quaternary structure and Redbeta-DNA complexes. In the absence of DNA, Redbeta forms a shallow right-handed helix. The presence of single-stranded DNA (ssDNA) disrupts this structure. Upon addition of a second complementary ssDNA, annealing generates a left-handed helix that incorporates 14 Redbeta monomers per helical turn, with each Redbeta monomer annealing approximately 11 bp of DNA. The smallest stable annealing intermediate requires 20 bp DNA and two Redbeta monomers. Hence, we propose that Redbeta promotes base pairing by first increasing the number of transient interactions between ssDNAs. Then, annealing is promoted by the binding of a second Redbeta monomer, which nucleates the formation of a stable annealing intermediate. Using threading, we identify sequence similarities between the RecT/Redbeta and the Rad52 families, which strengthens previous suggestions, based on similarities of their quaternary structures, that they share a common mode of action. Hence, our findings have implications for a common mechanism of DNA annealing mediated by single-strand annealing proteins including Rad52.

  17. A RAD-based phylogenetics for Orestias fishes from Lake Titicaca.

    Science.gov (United States)

    Takahashi, Tetsumi; Moreno, Edmundo

    2015-12-01

    The fish genus Orestias is endemic to the Andes highlands, and Lake Titicaca is the centre of the species diversity of the genus. Previous phylogenetic studies based on a single locus of mitochondrial and nuclear DNA strongly support the monophyly of a group composed of many of species endemic to the Lake Titicaca basin (the Lake Titicaca radiation), but the relationships among the species in the radiation remain unclear. Recently, restriction site-associated DNA (RAD) sequencing, which can produce a vast number of short sequences from various loci of nuclear DNA, has emerged as a useful way to resolve complex phylogenetic problems. To propose a new phylogenetic hypothesis of Orestias fishes of the Lake Titicaca radiation, we conducted a cluster analysis based on morphological similarities among fish samples and a molecular phylogenetic analysis based on RAD sequencing. From a morphological cluster analysis, we recognised four species groups in the radiation, and three of the four groups were resolved as monophyletic groups in maximum-likelihood trees based on RAD sequencing data. The other morphology-based group was not resolved as a monophyletic group in molecular phylogenies, and some members of the group were diverged from its sister group close to the root of the Lake Titicaca radiation. The evolution of these fishes is discussed from the phylogenetic relationships.

  18. Identification of SNP markers for inferring phylogeny in temperate bamboos (Poaceae: Bambusoideae) using RAD sequencing.

    Science.gov (United States)

    Wang, X Q; Zhao, L; Eaton, D A R; Li, D Z; Guo, Z H

    2013-09-01

    Phylogenetic relationships among temperate species of bamboo are difficult to resolve, owing to both the challenge of detecting sufficiently variable markers and their polyploid history. Here, we use restriction site-associated DNA sequencing to identify candidate loci with fixed allelic differences segregating between and within two temperate species of bamboos: Arundinaria faberi and Yushania brevipaniculata. Approximately 27 million paired-end sequencing reads were generated across four samples. From pooled data, we assembled 67 685 and 70 668 de novo contigs from partial overlap among paired-end reads, with an average length of 240 and 241 bp for the two species, respectively, which were used to investigate functional classification of RAD tags in a blastx search. Analysed separately by population, we recovered 29 443 putatively orthologous RAD tags shared across the four sampled populations, containing 28 023 sequence variants, of which c. 13 000 are segregating between species, and c. 3000 segregating between populations within each species. Analyses based on these RAD tags yielded robust phylogenetic inferences, even with data set constructed from surprisingly few loci. This study illustrates the potential for reduced-representation genome data to resolve difficult phylogenetic relationships in temperate bamboos. © 2013 John Wiley & Sons Ltd.

  19. Polymorphisms of RAD51B are associated with rheumatoid arthritis and erosion in rheumatoid arthritis patients

    Science.gov (United States)

    Zhi, Liqiang; Yao, Shuxin; Ma, Wenlong; Zhang, Weijie; Chen, Honggan; Li, Meng; Ma, Jianbing

    2017-01-01

    Rheumatoid arthritis (RA) is a common, chronic autoimmune disease affecting 0.5–1.0% of adults worldwide, including approximately 4.5–5.0 million patients in China. The genetic etiology and pathogenesis of RA have not yet been fully elucidated. Recently, one new RA susceptibility gene (RAD51B) has been identified in Korean and European populations. In this study, we designed a two-stage case-control study to further assess the relationship of common variants in the RAD51B gene with increased risk of RA in a total of 965 RA patients and 2,511 unrelated healthy controls of Han Chinese ancestry. We successfully identified a common variant, rs911263, as being significantly associated with the disease status of RA (P = 4.8 × 10−5, OR = 0.64). In addition, this SNP was shown to be related to erosion, a clinical assessment of disease severity in RA (P = 2.89 × 10−5, OR = 0.52). These findings shed light on the role of RAD51B in the onset and severity of RA. More research in the future is needed to clarify the underlying functional link between rs911263 and the disease. PMID:28361912

  20. Masimo Rad-57 Pulse CO-Oximeter for noninvasive carboxyhemoglobin measurement.

    Science.gov (United States)

    Suner, Selim; McMurdy, John

    2009-03-01

    Noninvasive methods of body fluid chemical measurement have been expanding. New technologies are enabling the quantification of different compounds in the blood and interstitial tissues. One example of this is the pulse oximeter, which has facilitated the measurement of oxyhemoglobin rapidly and reliably without the requirement of blood-draws. The Masimo Rad-57 Pulse CO-Oximeter expanded the capabilities of pulse-oximetry to include measurements of carboxyhemoglobin and methemoglobin. This innovation has revolutionized the paradigm for detection of patients with CO poisoning. Previously, clinicians relied on historical information and patient signs and symptoms pointing to the possibility of CO exposure or toxicity. Only then would a blood test be ordered to measure carboxyhemoglobin levels. Since the presentation of CO poisoning is nonspecific and overlaps with many other conditions, and since the presence of environmental CO is often unknown, the detection of this condition was only possible in cases where the presence of CO was obvious or where the symptoms were severe. We now know, from studies conducted using the Rad-57, the only US FDA-approved device for noninvasive measurement of SpCO, that there are a significant number of patients who experience CO exposure but are nonsymptomatic. The Rad-57 provides a clinical justification for screening in the healthcare setting to identify patients with significant CO exposure who would otherwise be undetected.

  1. Specific absorbed fractions of electrons and photons for Rad-HUMAN phantom using Monte Carlo method

    Institute of Scientific and Technical Information of China (English)

    WANG Wen; CHENG Meng-Yun; LONG Peng-Cheng; HU Li-Qin

    2015-01-01

    The specific absorbed fractions (SAF) for self-and cross-irradiation are effective tools for the internal dose estimation of inhalation and ingestion intakes of radionuclides.A set of SAFs of photons and electrons were calculated using the Rad-HUMAN phantom,which is a computational voxel phantom of a Chinese adult female that was created using the color photographic image of the Chinese Visible Human (CVH) data set by the FDS Team.The model can represent most Chinese adult female anatomical characteristics and can be taken as an individual phantom to investigate the difference of internal dose with Caucasians.In this study,the emission of mono-energetic photons and electrons of 10 keV to 4 MeV energy were calculated using the Monte Carlo particle transport calculation code MCNP.Results were compared with the values from ICRP reference and ORNL models.The results showed that SAF from the Rad-HUMAN have similar trends but are larger than those from the other two models.The differences were due to the racial and anatomical differences in organ mass and inter-organ distance.The SAFs based on the Rad-HUMAN phantom provide an accurate and reliable data for internal radiation dose calculations for Chinese females.

  2. Mapping institution-specific study descriptions to RadLex Playbook entries.

    Science.gov (United States)

    Mabotuwana, Thusitha; Lee, Michael C; Cohen-Solal, Eric V; Chang, Paul

    2014-06-01

    The naming of imaging procedures is currently not standardized across institutions. As a result, it is a challenge to establish national registries, for instance, a national registry of dose to facilitate comparisons among different types of CT procedures. RSNA's RadLex Playbook is an effort towards addressing this gap (by introducing a unique Playbook identifier called an RPID for each procedure), and the current research focuses on semi-automatically mapping institution-specific procedure descriptions to Playbook entries to assist with this standardization effort. We discuss an algorithm we have developed to facilitate the mapping process which first extracts RadLex codes from the procedure description and then uses the definition of an RPID to determine the most suitable RPID(s) for the extracted set of RadLex codes. We also developed a tool that has three modes of operations-a single procedure mapping mode that allows a user to map a single institution-specific procedure description to a Playbook entry, a bulk mode to process large number of descriptions, and an exploratory mode that assists a user to better understand how the selection of values for various Playbook attributes affects the resulting RPID. We validate our algorithms using 166 production CT procedure descriptions and discuss how the tool can be used by administrators to map institution-specific procedure descriptions to RPIDs.

  3. Cosmic ray dose monitoring using RadFET sensors of the Rosetta instruments SESAME and COSIMA

    Science.gov (United States)

    Falke, Peter; Fischer, Hans-Herbert; Seidensticker, Klaus J.; Thiel, Klaus; Fischer, Henning; Hilchenbach, Martin; Henkel, Hartmut; Koch, Andreas

    2016-08-01

    On its more than 10 years journey to comet 67P/Churyumov-Gerasimenko, Rosetta carried RadFET ionising dose monitors in the central electronics of the orbiter instrument COSIMA and the lander instrument SESAME. The readings of the dosimeters were corrected for the temperature of the devices during measurements. Because the sensitivity of RadFETs depends on the energy of impinging charged particles, a mean efficiency factor for the prevalent proton radiation was determined by applying nine efficiency models to proton energy spectra of Rosetta's radiation environment. The resulting dose profiles show linear increases of the accumulated dose with time, mainly caused by galactic cosmic radiation, and the arrival of two solar particle events in 2005. The accumulated dose (in Silicon) during 3909 days in space from 2004-03-02 to 2014-11-14 was 3.2 ± 0.6 Gy in case of COSIMA and 1.9 ± 0.4 Gy for SESAME. The deviation of the two measurements is mainly due to the solar particle event in September 2005, which had a 5.3 ± 1.0 times stronger impact on the COSIMA RadFET. Measured dose levels are one order of magnitude lower than those expected before launch for not being exceeded on the 90% confidence level, which is mainly due to the low solar activity during the mission so far.

  4. Enhancement of gene targeting in human cells by intranuclear permeation of the Saccharomyces cerevisiae Rad52 protein

    Science.gov (United States)

    Kalvala, Arjun; Rainaldi, Giuseppe; Di Primio, Cristina; Liverani, Vania; Falaschi, Arturo; Galli, Alvaro

    2010-01-01

    The introduction of exogenous DNA in human somatic cells results in a frequency of random integration at least 100-fold higher than gene targeting (GT), posing a seemingly insurmountable limitation for gene therapy applications. We previously reported that, in human cells, the stable over-expression of the Saccharomyces cerevisiae Rad52 gene (yRAD52), which plays the major role in yeast homologous recombination (HR), caused an up to 37-fold increase in the frequency of GT, indicating that yRAD52 interacts with the double-strand break repair pathway(s) of human cells favoring homologous integration. In the present study, we tested the effect of the yRad52 protein by delivering it directly to the human cells. To this purpose, we fused the yRAD52 cDNA to the arginine-rich domain of the TAT protein of HIV (tat11) that is known to permeate the cell membranes. We observed that a recombinant yRad52tat11 fusion protein produced in Escherichia coli, which maintains its ability to bind single-stranded DNA (ssDNA), enters the cells and the nuclei, where it is able to increase both intrachromosomal recombination and GT up to 63- and 50-fold, respectively. Moreover, the non-homologous plasmid DNA integration decreased by 4-fold. yRAD52tat11 proteins carrying point mutations in the ssDNA binding domain caused a lower or nil increase in recombination proficiency. Thus, the yRad52tat11 could be instrumental to increase GT in human cells and a ‘protein delivery approach’ offers a new tool for developing novel strategies for genome modification and gene therapy applications. PMID:20519199

  5. Breast Imaging Reporting and Data System (BI-RADS) breast composition descriptors: Automated measurement development for full field digital mammography

    OpenAIRE

    Fowler, E. E.; Sellers, T.A.; Lu, B.; Heine, J.J.

    2013-01-01

    Purpose: The Breast Imaging Reporting and Data System (BI-RADS) breast composition descriptors are used for standardized mammographic reporting and are assessed visually. This reporting is clinically relevant because breast composition can impact mammographic sensitivity and is a breast cancer risk factor. New techniques are presented and evaluated for generating automated BI-RADS breast composition descriptors using both raw and calibrated full field digital mammography (FFDM) image data.

  6. Linkage mapping and comparative genomics using next-generation RAD sequencing of a non-model organism.

    Directory of Open Access Journals (Sweden)

    Simon W Baxter

    Full Text Available Restriction-site associated DNA (RAD sequencing is a powerful new method for targeted sequencing across the genomes of many individuals. This approach has broad potential for genetic analysis of non-model organisms including genotype-phenotype association mapping, phylogeography, population genetics and scaffolding genome assemblies through linkage mapping. We constructed a RAD library using genomic DNA from a Plutella xylostella (diamondback moth backcross that segregated for resistance to the insecticide spinosad. Sequencing of 24 individuals was performed on a single Illumina GAIIx lane (51 base paired-end reads. Taking advantage of the lack of crossing over in homologous chromosomes in female Lepidoptera, 3,177 maternally inherited RAD alleles were assigned to the 31 chromosomes, enabling identification of the spinosad resistance and W/Z sex chromosomes. Paired-end reads for each RAD allele were assembled into contigs and compared to the genome of Bombyx mori (n = 28 using BLAST, revealing 28 homologous matches plus 3 expected fusion/breakage events which account for the difference in chromosome number. A genome-wide linkage map (1292 cM was inferred with 2,878 segregating RAD alleles inherited from the backcross father, producing chromosome and location specific sequenced RAD markers. Here we have used RAD sequencing to construct a genetic linkage map de novo for an organism that has no previous genome data. Comparative analysis of P. xyloxtella linkage groups with B. mori chromosomes shows for the first time, genetic synteny appears common beyond the Macrolepidoptera. RAD sequencing is a powerful system capable of rapidly generating chromosome specific data for non-model organisms.

  7. Coordination of BRCA1/BARD1- and MRE11/RAD50/NBS1-dependent DNA Transactions in Breast Tumor Suppression

    Science.gov (United States)

    2011-07-01

    recombi - nation and DNA damage checkpoint activation require CDK1. Nature 431:1011–17 61. Ivanov EL, Sugawara N, White CI, Fabre F, Haber JE. 1994...RAD50/NBS1-dependent DNA transactions in breast tumor suppression PRINCIPAL INVESTIGATOR: Jean Gautier, Ph.D...30 June 2011 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Coordination of BRCA1/BARD1- and MRE11/RAD50/NBS1-dependent DNA transactions in breast

  8. Real-time solution measurement of RAD51- and RecA-mediated strand assimilation without background annealing.

    Science.gov (United States)

    Budke, Brian; Chan, Yuen-Ling; Bishop, Douglas K; Connell, Philip P

    2013-07-01

    RAD51 is the central strand exchange recombinase in somatic homologous recombination, providing genomic stability and promoting resistance to DNA damage. An important tool for mechanistic studies of RAD51 is the D-loop or strand assimilation assay, which measures the ability of RAD51-coated single-stranded DNA (ssDNA) to search for, invade and exchange ssDNA strands with a homologous duplex DNA target. As cancer cells generally overexpress RAD51, the D-loop assay has also emerged as an important tool in oncologic drug design programs for targeting RAD51. Previous studies have adapted the traditional gel-based D-loop assay by using fluorescence-based substrates, which in principle allow for use in high-throughput screening platforms. However, these existing D-loop methods depend on linear oligonucleotide DNA duplex targets, and these substrates enable recombinase-independent ssDNA annealing that can obscure the recombinase-dependent strand assimilation signal. This compelled us to fundamentally re-design this assay, using a fluorescent target substrate that consists of a covalently closed linear double-hairpin dsDNA. This new microplate-based method represents a fast, inexpensive and non-radioactive alternative to existing D-loop assays. It provides accurate kinetic analysis of strand assimilation in high-throughput and performs well with human RAD51 and Escherichia coli RecA protein. This advance will aid in both mechanistic studies of homologous recombination and drug screening programs.

  9. Lessons learned from the Radiation measurements of the Mars Science Lab Radiation Assessment Detector (MSL-RAD)

    Science.gov (United States)

    Reitz, Guenther; Ottolenghi, Andrea

    2016-07-01

    The Radiation Assessment Detector (RAD) was designed to characterize the radiation environment on the Mars surface and to contribute to an improved assessment of radiation risk for a future human mission to Mars. The flight was chosen to cover a period of solar maximum activity to allow besides the measurement of the galactic cosmic rays an intense study of exposures by solar particle events. The Mars Science Laboratory spacecraft (MSL), containing the Curiosity rover, in which RAD was integrated, was launched to Mars on November 26, 2011. Although not part of the mission planning, RAD was operated already during the 253 day and 560 million km cruise to Mars and made the first time detailed measurements of a radiation environment comparable to that inside a future spacecraft carrying humans to Mars and in other deep space missions. Exactly 100 years after the discovery of cosmic rays on August 7, 1912 RAD makes the first observation of the radiation environment on the surface of another planet and is still gathering data until today. Meanwhile the maximum activity of the current solar cycle has been passed and the solar activity is decreasing. Unfortunately the present solar cycle was an unexpected weak cycle. As a matter of fact only very small solar particle events could be observed during the still ongoing RAD measurements. The paper highlights the achievements of RAD by presenting selected data measured during the cruise and on the Mars surface and describes its impact on predictive models for health risks of astronauts during space missions.

  10. MR (Mre11-Rad50) complex in Giardia duodenalis: In vitro characterization and its response upon DNA damage.

    Science.gov (United States)

    Sandoval-Cabrera, A; Zarzosa-Álvarez, A L; Martínez-Miguel, R M; Bermúdez-Cruz, R M

    2015-04-01

    Giardia duodenalis is a well-known protozoan parasite of humans and other mammals. The repair of DNA double strand breaks (DSBs) is crucial for genomic stability and homologous recombination is one of the primary mechanisms used by cells to repair DNA. The Mre11 complex is comprised by Mre11, an endonuclease and 3'-5' exonuclease known to resect ends during homologous recombination, and Rad50, a member of the structural maintenance of chromosomes (SMC) family of ATPases. In this work we cloned, expressed and characterized the catalytic activities of the giardial Mre11 (GdMre11) and Rad50 (GdRad50) proteins. Our results show that while purified recombinant GdMre11 and GdRad50 proteins bind DNA, GdMre11 contains a 3'-5' exonuclease and purified recombinant GdRad50 has ATPase activity. The predicted structure for GdMre11 revealed a conserved Mn(2+) dependent binding pocket. We also explored the expression of giardial mre11 and rad50 genes after ionizing radiation, and our results indicate that both specific transcripts were increased after 1-2 h while their protein levels were found to be significantly increased 4 h after gamma radiation treatment. These proteins were localized in the nuclei before and after irradiation. The implication of these observations is discussed.

  11. HSV-1 amplicon-mediated post-transcriptional inhibition of Rad51 sensitizes human glioma cells to ionizing radiation.

    Science.gov (United States)

    Saydam, O; Saydam, N; Glauser, D L; Pruschy, M; Dinh-Van, V; Hilbe, M; Jacobs, A H; Ackermann, M; Fraefel, C

    2007-08-01

    Standard treatment for glioblastoma multiforme and other brain tumors consists of surgical resection followed by combined radio-/chemotherapy. However, radiation resistance of tumor cells limits the success of this treatment, and the tumors invariably recur. Therefore, the selective inhibition of molecular mediators of radiation resistance may provide therapeutic benefit to the patient. One of these targets is the Rad51 protein, which is a key component of the homologous recombinational repair of DNA double-strand breaks. Here, we investigated whether post-transcriptional silencing of Rad51 by herpes simplex virus-type 1 (HSV-1) amplicon vector-mediated short interfering RNA expression can enhance the antitumor effect of radiation therapy. We demonstrate that these vectors specifically and efficiently inhibited the radiation-induced recruitment of Rad51 into nuclear foci in human glioma cells. The combination of vector-mediated silencing of Rad51 expression and treatment with ionizing radiation resulted in a pronounced reduction of the survival of human glioma cells in culture. In athymyc mice, a single intratumoral injection of Rad51-specific HSV-1 amplicon vector followed by a single radiation treatment resulted in a significant decrease in tumor size. In control animals, including mice that received an intratumoral injection of Rad51-specific amplicon vector but no radiation treatment, the tumor sizes increased.

  12. Enhancing CRISPR/Cas9-mediated homology-directed repair in mammalian cells by expressing Saccharomyces cerevisiae Rad52.

    Science.gov (United States)

    Shao, Simin; Ren, Chonghua; Liu, Zhongtian; Bai, Yichun; Chen, Zhilong; Wei, Zehui; Wang, Xin; Zhang, Zhiying; Xu, Kun

    2017-09-18

    Precise genome editing with desired point mutations can be generated by CRISPR/Cas9-mediated homology-directed repair (HDR) and is of great significance for gene function study, gene therapy and animal breeding. However, HDR efficiency is inherently low and improvements are necessitated. Herein, we determined that the HDR efficiency could be enhanced by expressing Rad52, a gene that is involved in the homologous recombination process. Both the Rad52 co-expression and Rad52-Cas9 fusion strategies yielded approximately 3-fold increase in HDR during the surrogate reporter assays in human HEK293T cells, as well as in the genome editing assays. Moreover, the enhancement effects of the Rad52-Cas9 fusion on HDR mediated by different (plasmid, PCR and ssDNA) donor templates were confirmed. We found that the HDR efficiency could be significantly improved to about 40% by the combined usage of Rad52 and Scr7. In addition, we also applied the fusion strategy for modifying the IGF2 gene of porcine PK15 cells, which further demonstrated a 2.2-fold increase in HDR frequency. In conclusion, our data suggests that Rad52-Cas9 fusion is a good option for enhancing CRISPR/Cas9-mediated HDR, which may be of use in future studies involving precise genome editing. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. A framework phylogeny of the American oak clade based on sequenced RAD data.

    Science.gov (United States)

    Hipp, Andrew L; Eaton, Deren A R; Cavender-Bares, Jeannine; Fitzek, Elisabeth; Nipper, Rick; Manos, Paul S

    2014-01-01

    Previous phylogenetic studies in oaks (Quercus, Fagaceae) have failed to resolve the backbone topology of the genus with strong support. Here, we utilize next-generation sequencing of restriction-site associated DNA (RAD-Seq) to resolve a framework phylogeny of a predominantly American clade of oaks whose crown age is estimated at 23-33 million years old. Using a recently developed analytical pipeline for RAD-Seq phylogenetics, we created a concatenated matrix of 1.40 E06 aligned nucleotides, constituting 27,727 sequence clusters. RAD-Seq data were readily combined across runs, with no difference in phylogenetic placement between technical replicates, which overlapped by only 43-64% in locus coverage. 17% (4,715) of the loci we analyzed could be mapped with high confidence to one or more expressed sequence tags in NCBI Genbank. A concatenated matrix of the loci that BLAST to at least one EST sequence provides approximately half as many variable or parsimony-informative characters as equal-sized datasets from the non-EST loci. The EST-associated matrix is more complete (fewer missing loci) and has slightly lower homoplasy than non-EST subsampled matrices of the same size, but there is no difference in phylogenetic support or relative attribution of base substitutions to internal versus terminal branches of the phylogeny. We introduce a partitioned RAD visualization method (implemented in the R package RADami; http://cran.r-project.org/web/packages/RADami) to investigate the possibility that suboptimal topologies supported by large numbers of loci--due, for example, to reticulate evolution or lineage sorting--are masked by the globally optimal tree. We find no evidence for strongly-supported alternative topologies in our study, suggesting that the phylogeny we recover is a robust estimate of large-scale phylogenetic patterns in the American oak clade. Our study is one of the first to demonstrate the utility of RAD-Seq data for inferring phylogeny in a 23-33 million

  14. A framework phylogeny of the American oak clade based on sequenced RAD data.

    Directory of Open Access Journals (Sweden)

    Andrew L Hipp

    Full Text Available Previous phylogenetic studies in oaks (Quercus, Fagaceae have failed to resolve the backbone topology of the genus with strong support. Here, we utilize next-generation sequencing of restriction-site associated DNA (RAD-Seq to resolve a framework phylogeny of a predominantly American clade of oaks whose crown age is estimated at 23-33 million years old. Using a recently developed analytical pipeline for RAD-Seq phylogenetics, we created a concatenated matrix of 1.40 E06 aligned nucleotides, constituting 27,727 sequence clusters. RAD-Seq data were readily combined across runs, with no difference in phylogenetic placement between technical replicates, which overlapped by only 43-64% in locus coverage. 17% (4,715 of the loci we analyzed could be mapped with high confidence to one or more expressed sequence tags in NCBI Genbank. A concatenated matrix of the loci that BLAST to at least one EST sequence provides approximately half as many variable or parsimony-informative characters as equal-sized datasets from the non-EST loci. The EST-associated matrix is more complete (fewer missing loci and has slightly lower homoplasy than non-EST subsampled matrices of the same size, but there is no difference in phylogenetic support or relative attribution of base substitutions to internal versus terminal branches of the phylogeny. We introduce a partitioned RAD visualization method (implemented in the R package RADami; http://cran.r-project.org/web/packages/RADami to investigate the possibility that suboptimal topologies supported by large numbers of loci--due, for example, to reticulate evolution or lineage sorting--are masked by the globally optimal tree. We find no evidence for strongly-supported alternative topologies in our study, suggesting that the phylogeny we recover is a robust estimate of large-scale phylogenetic patterns in the American oak clade. Our study is one of the first to demonstrate the utility of RAD-Seq data for inferring phylogeny in a

  15. Linkage maps of the Atlantic salmon (Salmo salar) genome derived from RAD sequencing.

    Science.gov (United States)

    Gonen, Serap; Lowe, Natalie R; Cezard, Timothé; Gharbi, Karim; Bishop, Stephen C; Houston, Ross D

    2014-02-27

    Genetic linkage maps are useful tools for mapping quantitative trait loci (QTL) influencing variation in traits of interest in a population. Genotyping-by-sequencing approaches such as Restriction-site Associated DNA sequencing (RAD-Seq) now enable the rapid discovery and genotyping of genome-wide SNP markers suitable for the development of dense SNP linkage maps, including in non-model organisms such as Atlantic salmon (Salmo salar). This paper describes the development and characterisation of a high density SNP linkage map based on SbfI RAD-Seq SNP markers from two Atlantic salmon reference families. Approximately 6,000 SNPs were assigned to 29 linkage groups, utilising markers from known genomic locations as anchors. Linkage maps were then constructed for the four mapping parents separately. Overall map lengths were comparable between male and female parents, but the distribution of the SNPs showed sex-specific patterns with a greater degree of clustering of sire-segregating SNPs to single chromosome regions. The maps were integrated with the Atlantic salmon draft reference genome contigs, allowing the unique assignment of ~4,000 contigs to a linkage group. 112 genome contigs mapped to two or more linkage groups, highlighting regions of putative homeology within the salmon genome. A comparative genomics analysis with the stickleback reference genome identified putative genes closely linked to approximately half of the ordered SNPs and demonstrated blocks of orthology between the Atlantic salmon and stickleback genomes. A subset of 47 RAD-Seq SNPs were successfully validated using a high-throughput genotyping assay, with a correspondence of 97% between the two assays. This Atlantic salmon RAD-Seq linkage map is a resource for salmonid genomics research as genotyping-by-sequencing becomes increasingly common. This is aided by the integration of the SbfI RAD-Seq SNPs with existing reference maps and the draft reference genome, as well as the identification of

  16. Rad-Hard, Miniaturized, Scalable, High-Voltage Switching Module for Power Applications Rad-Hard, Miniaturized

    Science.gov (United States)

    Adell, Philippe C.; Mojarradi, Mohammad; DelCastillo, Linda Y.; Vo, Tuan A.

    2011-01-01

    A paper discusses the successful development of a miniaturized radiation hardened high-voltage switching module operating at 2.5 kV suitable for space application. The high-voltage architecture was designed, fabricated, and tested using a commercial process that uses a unique combination of 0.25 micrometer CMOS (complementary metal oxide semiconductor) transistors and high-voltage lateral DMOS (diffusion metal oxide semiconductor) device with high breakdown voltage (greater than 650 V). The high-voltage requirements are achieved by stacking a number of DMOS devices within one module, while two modules can be placed in series to achieve higher voltages. Besides the high-voltage requirements, a second generation prototype is currently being developed to provide improved switching capabilities (rise time and fall time for full range of target voltages and currents), the ability to scale the output voltage to a desired value with good accuracy (few percent) up to 10 kV, to cover a wide range of high-voltage applications. In addition, to ensure miniaturization, long life, and high reliability, the assemblies will require intensive high-voltage electrostatic modeling (optimized E-field distribution throughout the module) to complete the proposed packaging approach and test the applicability of using advanced materials in a space-like environment (temperature and pressure) to help prevent potential arcing and corona due to high field regions. Finally, a single-event effect evaluation would have to be performed and single-event mitigation methods implemented at the design and system level or developed to ensure complete radiation hardness of the module.

  17. Radon: risk to health? El radón: ¿riesgo para la salud?

    Directory of Open Access Journals (Sweden)

    Juan Miguel Barros Dios

    2011-12-01

    Full Text Available Radon (Rn222 is a radioactive noble gas whose origin is Radium (Ra226 when it emits an alpha particle (two protons and two neutrons or a helium nucleus. Rn222 transforms in another radioactive element (Po218 when an alpha particle is emitted. Its carcinogenic effect on the lung was discovered various decades ago, first on uranium miners and later on general population exposed at home to residential radon. The main factor influencing radon concentration in dwellings is the uranium content of the subsoil, since uranium is the first element of the radioactive disintegration chain where radon appears. Geological risk areas of Spain due to their granite and therefore uranium content are Galicia, the Northwest and the West of Spain. Numerous countries of Europe and America have enforced legislation focused to protect population and reduce radon concentration in order to prevent lung cancer appearance. These laws comprise public buildings and private homes. Since the late 80s, alpha radiation generated by radon and its short-life descendents has been classified as carcinogenic agents by the International Agency for Research on Cancer (Lyon, 1988 and the National Research Council (BEIR IV, 1988.El radón (Rn222 es un gas noble radiactivo que procede directamente del radio (Ra226 cuando este emite una partícula alfa (dos protones y dos neutrones o núcleo de helio, y que a su vez se transforma en otro elemento radiactivo (Po218 al desprenderse de otra partícula alfa. Desde hace varias décadas se conoce su efecto como factor de riesgo del cáncer primario pulmonar, primero en mineros del uranio y posteriormente en la población general expuesta al radón residencial en hogares construidos sobre suelos de rocas ricas en uranio (U238, elemento inicial de la cadena de degradación radiactiva de la que procede el radón. Áreas geológicamente constituidas por granitos o pizarras, como son las de gran parte de Galicia y todo el noroeste y oeste de la pen

  18. XRCC3 ATPase activity is required for normal XRCC3-Rad51C complex dynamics and homologous recombination

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, N; Hinz, J; Kopf, V L; Segalle, K; Thompson, L

    2004-02-25

    Homologous recombinational repair is a major DNA repair pathway that preserves chromosomal integrity by removing double-strand breaks, crosslinks, and other DNA damage. In eukaryotic cells, the Rad51 paralogs (XRCC2, XRCC3, Rad51B, Rad51C, and Rad51D) are involved in this process, although their exact functions are largely undetermined. All five paralogs contain ATPase motifs, and XRCC3 appears to exist in a single complex with Rad51C. To begin to examine the function of this Rad51C-XRCC3 complex, we generated mammalian expression vectors that produce human wild-type XRCC3 or mutant XRCC3 with either a non-conservative mutation (K113A) or a conservative mutation (K113R) in the GKT Walker A box of the ATPase motif. The three vectors were independently transfected into Xrcc3-deficient irs1SF CHO cells. Wild-type XRCC3 complemented irs1SF cells, albeit to varying degrees, while ATPase mutants had no complementing activity, even when the mutant protein was expressed at comparable levels to that in wild-type-complemented clones. Because of the mutants' dysfunction, we propose that ATP binding and hydrolyzing activities of XRCC3 are essential. We tested in vitro complex formation by wild-type and mutant XRCC3 with His6-tagged Rad51C upon coexpression in bacteria, nickel affinity purification, and western blotting. Wild-type and K113A mutant XRCC3 formed stable complexes with Rad51C and co-purified with Rad51C, while the K113R mutant did not and was predominantly insoluble. Addition of 5 mM ATP, but not ADP, also abolished complex formation by the wild-type proteins. These results suggest that XRCC3 is likely to regulate the dissociation and formation of Rad51C-XRCC3 complex through ATP binding and hydrolysis, with both processes being essential for the complex's ability to participate in HRR.

  19. Magnetic phase transitions in the anion-deficient La sub 1 sub - sub x Ba sub x MnO sub 3 sub - sub x sub / sub 2 (0 <= x <= 0.50) manganites

    CERN Document Server

    Trukhanov, S V; Bushinsky, M V; Troyanchuk, I O; Szymczak, H

    2003-01-01

    The crystal structure, magnetization and electrical resistivity properties of the anion-deficient La sub 1 sub - sub x Ba sub x MnO sub 3 sub - sub x sub / sub 2 (0 = 0.03) being a mixture of antiferromagnetic and ferromagnetic phases. At x >= 0.12 competition between antiferromagnetic and ferromagnetic interactions leads to a cluster spin glass state appearance with a magnetic moment freezing temperature of approx 45 K. The dominant magnetic phase for x >= 0.22 is supposed to be antiferromagnetic. All the reduced samples are semiconductors and show considerable magnetoresistance over a wide temperature range in a magnetically ordered state. The largest magnetoresistance (approx 34% in a 9 kOe field at liquid nitrogen temperatures) is observed for an x = 0.30 sample. The magnetic phase diagram of La sub 1 sub - sub x sup 3 sup + Ba sub x sup 2 sup + Mn sup 3 sup + O sub 3 sub - sub x sub / sub 2 sup 2 sup - manganites has been established by combining the results of magnetic and electrical measurements. The r...

  20. Preparation, phase transition and thermal expansion studies on low-cristobalite type Al 1- xGa xPO 4 ( x=0.0, 0.20, 0.50, 0.80 and 1.00)

    Science.gov (United States)

    Achary, S. N.; Jayakumar, O. D.; Tyagi, A. K.; Kulshresththa, S. K.

    2003-11-01

    The orthorhombic ( α) low-cristobalite type AlPO 4 and GaPO 4 and their solid solutions are prepared by co-precipitation followed by high temperature annealing of the precipitate. The single phasic nature of the products is ascertained by powder XRD at room temperature. The high temperature behavior of these samples is studied by HT-XRD over the temperature range of 25-1000°C. All these compositions undergo an orthorhombic to cubic ( β, high-cristobalite) phase transition at elevated temperature. The unit cell parameters at different temperatures are determined by refining the observed powder diffraction profiles. The phase transition is accompanied by a significant increase in the unit cell volume, leading to the formation of a low dense structure. The variation of unit cell volume with temperature for each composition shows that the orthorhombic phase has a significantly larger thermal expansion than the cubic (high temperature) phase. The high temperature behavior of all the compositions except the GaPO 4 is similar. GaPO 4 undergoes a phase separation to a more stable quartz type phase above 800°C. However, the quartz type phase again transforms to the high cristobalite ( β) phase at 1000°C. Thermal expansions of all these phases are explained in term of the variation of M-O-P angle as a function of temperature.

  1. Cellular Ubc2/Rad6 E2 ubiquitin-conjugating enzyme facilitates tombusvirus replication in yeast and plants

    Energy Technology Data Exchange (ETDEWEB)

    Imura, Yoshiyuki, E-mail: imura@brs.nihon-u.ac.jp; Molho, Melissa; Chuang, Chingkai; Nagy, Peter D., E-mail: pdnagy2@uky.edu

    2015-10-15

    Mono- and multi-ubiquitination alters the functions and subcellular localization of many cellular and viral proteins. Viruses can co-opt or actively manipulate the ubiquitin network to support viral processes or suppress innate immunity. Using yeast (Saccharomyces cerevisiae) model host, we show that the yeast Rad6p (radiation sensitive 6) E2 ubiquitin-conjugating enzyme and its plant ortholog, AtUbc2, interact with two tombusviral replication proteins and these E2 ubiquitin-conjugating enzymes could be co-purified with the tombusvirus replicase. We demonstrate that TBSV RNA replication and the mono- and bi-ubiquitination level of p33 is decreased in rad6Δ yeast. However, plasmid-based expression of AtUbc2p could complement both defects in rad6Δ yeast. Knockdown of UBC2 expression in plants also decreases tombusvirus accumulation and reduces symptom severity, suggesting that Ubc2p is critical for virus replication in plants. We provide evidence that Rad6p is involved in promoting the subversion of Vps23p and Vps4p ESCRT proteins for viral replicase complex assembly. - Highlights: • Tombusvirus p33 replication protein interacts with cellular RAD6/Ubc2 E2 enzymes. • Deletion of RAD6 reduces tombusvirus replication in yeast. • Silencing of UBC2 in plants inhibits tombusvirus replication. • Mono- and bi-ubiquitination of p33 replication protein in yeast and in vitro. • Rad6p promotes the recruitment of cellular ESCRT proteins into the tombusvirus replicase.

  2. Adenoviral Vector Driven by a Minimal Rad51 Promoter Is Selective for p53-Deficient Tumor Cells

    Science.gov (United States)

    Fong, Vincent; Osterbur, Marika; Capella, Cristina; Kim, Yo-El; Hine, Christopher; Gorbunova, Vera; Seluanov, Andrei; Dewhurst, Stephen

    2011-01-01

    Background The full length Rad51 promoter is highly active in cancer cells but not in normal cells. We therefore set out to assess whether we could confer this tumor-selectivity to an adenovirus vector. Methodology/Principal Findings Expression of an adenovirally-vectored luciferase reporter gene from the Rad51 promoter was up to 50 fold higher in cancer cells than in normal cells. Further evaluations of a panel of truncated promoter mutants identified a 447 bp minimal core promoter element that retained the full tumor selectivity and transcriptional activity of the original promoter, in the context of an adenovirus vector. This core Rad51 promoter was highly active in cancer cells that lack functional p53, but less active in normal cells and in cancer cell lines with intact p53 function. Exogenous expression of p53 in a p53 null cell line strongly suppressed activity of the Rad51 core promoter, underscoring the selectivity of this promoter for p53-deficient cells. Follow-up experiments showed that the p53-dependent suppression of the Rad51 core promoter was mediated via an indirect, p300 coactivator dependent mechanism. Finally, transduction of target cells with an adenovirus vector encoding the thymidine kinase gene under transcriptional control of the Rad51 core promoter resulted in efficient killing of p53 defective cancer cells, but not of normal cells, upon addition of ganciclovir. Conclusions/Significance Overall, these experiments demonstrated that a small core domain of the Rad51 promoter can be used to target selective transgene expression from adenoviral vectors to tumor cells lacking functional p53. PMID:22174876

  3. Adenoviral vector driven by a minimal Rad51 promoter is selective for p53-deficient tumor cells.

    Directory of Open Access Journals (Sweden)

    Vincent Fong

    Full Text Available BACKGROUND: The full length Rad51 promoter is highly active in cancer cells but not in normal cells. We therefore set out to assess whether we could confer this tumor-selectivity to an adenovirus vector. METHODOLOGY/PRINCIPAL FINDINGS: Expression of an adenovirally-vectored luciferase reporter gene from the Rad51 promoter was up to 50 fold higher in cancer cells than in normal cells. Further evaluations of a panel of truncated promoter mutants identified a 447 bp minimal core promoter element that retained the full tumor selectivity and transcriptional activity of the original promoter, in the context of an adenovirus vector. This core Rad51 promoter was highly active in cancer cells that lack functional p53, but less active in normal cells and in cancer cell lines with intact p53 function. Exogenous expression of p53 in a p53 null cell line strongly suppressed activity of the Rad51 core promoter, underscoring the selectivity of this promoter for p53-deficient cells. Follow-up experiments showed that the p53-dependent suppression of the Rad51 core promoter was mediated via an indirect, p300 coactivator dependent mechanism. Finally, transduction of target cells with an adenovirus vector encoding the thymidine kinase gene under transcriptional control of the Rad51 core promoter resulted in efficient killing of p53 defective cancer cells, but not of normal cells, upon addition of ganciclovir. CONCLUSIONS/SIGNIFICANCE: Overall, these experiments demonstrated that a small core domain of the Rad51 promoter can be used to target selective transgene expression from adenoviral vectors to tumor cells lacking functional p53.

  4. The KYxxL motif in Rad17 protein is essential for the interaction with the 9–1–1 complex

    Energy Technology Data Exchange (ETDEWEB)

    Fukumoto, Yasunori, E-mail: fukumoto@faculty.chiba-u.jp [Laboratory of Molecular Cell Biology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675 (Japan); Ikeuchi, Masayoshi; Nakayama, Yuji [Department of Biochemistry & Molecular Biology, Kyoto Pharmaceutical University, Kyoto 607-8414 (Japan); Yamaguchi, Naoto, E-mail: nyama@faculty.chiba-u.jp [Laboratory of Molecular Cell Biology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675 (Japan)

    2016-09-02

    ATR-dependent DNA damage checkpoint is the major DNA damage checkpoint against UV irradiation and DNA replication stress. The Rad17–RFC and Rad9–Rad1–Hus1 (9–1–1) complexes interact with each other to contribute to ATR signaling, however, the precise regulatory mechanism of the interaction has not been established. Here, we identified a conserved sequence motif, KYxxL, in the AAA+ domain of Rad17 protein, and demonstrated that this motif is essential for the interaction with the 9–1–1 complex. We also show that UV-induced Rad17 phosphorylation is increased in the Rad17 KYxxL mutants. These data indicate that the interaction with the 9–1–1 complex is not required for Rad17 protein to be an efficient substrate for the UV-induced phosphorylation. Our data also raise the possibility that the 9–1–1 complex plays a negative regulatory role in the Rad17 phosphorylation. We also show that the nucleotide-binding activity of Rad17 is required for its nuclear localization. - Highlights: • We have identified a conserved KYxxL motif in Rad17 protein. • The KYxxL motif is crucial for the interaction with the 9–1–1 complex. • The KYxxL motif is dispensable or inhibitory for UV-induced Rad17 phosphorylation. • Nucleotide binding of Rad17 is required for its nuclear localization.

  5. Genetic variants within microRNA‐binding site of RAD51B are associated with risk of cervical cancer in Chinese women

    OpenAIRE

    Hang, Dong; Zhou, Wen; Jia, Meiqun; WANG Lihua; Zhou, Jing; Yin, Yin; Ma, Hongxia; Hu, Zhibin; Li, Ni; Shen, Hongbin

    2016-01-01

    Abstract RAD51B plays a central role in homologous recombinational repair (HRR) of DNA double‐strand breaks (DSBs), which is important to prevent genomic instability, a hallmark of cancer. Recent studies suggested that common genetic variants of RAD51B may contribute to cancer susceptibility. In this study, we aimed to investigate whether potentially functional variants within miRNA‐binding sites of RAD51B are associated with risk of cervical cancer. A total of 1486 cervical cancer patients a...

  6. MagRad: A code to optimize the operation of superconducting magnets in a radiation environment

    Energy Technology Data Exchange (ETDEWEB)

    Yeaw, Christopher T. [Univ. of Wisconsin, Madison, WI (United States)

    1995-01-01

    A powerful computational tool, called MagRad, has been developed which optimizes magnet design for operation in radiation fields. Specifically, MagRad has been used for the analysis and design modification of the cable-in-conduit conductors of the TF magnet systems in fusion reactor designs. Since the TF magnets must operate in a radiation environment which damages the material components of the conductor and degrades their performance, the optimization of conductor design must account not only for start-up magnet performance, but also shut-down performance. The degradation in performance consists primarily of three effects: reduced stability margin of the conductor; a transition out of the well-cooled operating regime; and an increased maximum quench temperature attained in the conductor. Full analysis of the magnet performance over the lifetime of the reactor includes: radiation damage to the conductor, stability, protection, steady state heat removal, shielding effectiveness, optimal annealing schedules, and finally costing of the magnet and reactor. Free variables include primary and secondary conductor geometric and compositional parameters, as well as fusion reactor parameters. A means of dealing with the radiation damage to the conductor, namely high temperature superconductor anneals, is proposed, examined, and demonstrated to be both technically feasible and cost effective. Additionally, two relevant reactor designs (ITER CDA and ARIES-II/IV) have been analyzed. Upon addition of pure copper strands to the cable, the ITER CDA TF magnet design was found to be marginally acceptable, although much room for both performance improvement and cost reduction exists. A cost reduction of 10-15% of the capital cost of the reactor can be achieved by adopting a suitable superconductor annealing schedule. In both of these reactor analyses, the performance predictive capability of MagRad and its associated costing techniques have been demonstrated.

  7. Enhanced Histone Deacetylase Activity in Malignant Melanoma Provokes RAD51 and FANCD2-Triggered Drug Resistance.

    Science.gov (United States)

    Krumm, Andrea; Barckhausen, Christina; Kücük, Pelin; Tomaszowski, Karl-Heinz; Loquai, Carmen; Fahrer, Jörg; Krämer, Oliver Holger; Kaina, Bernd; Roos, Wynand Paul

    2016-05-15

    DNA-damaging anticancer drugs remain a part of metastatic melanoma therapy. Epigenetic reprogramming caused by increased histone deacetylase (HDAC) activity arising during tumor formation may contribute to resistance of melanomas to the alkylating drugs temozolomide, dacarbazine, and fotemustine. Here, we report on the impact of class I HDACs on the response of malignant melanoma cells treated with alkylating agents. The data show that malignant melanomas in situ contain a high level of HDAC1/2 and malignant melanoma cells overexpress HDAC1/2/3 compared with noncancer cells. Furthermore, pharmacologic inhibition of class I HDACs sensitizes malignant melanoma cells to apoptosis following exposure to alkylating agents, while not affecting primary melanocytes. Inhibition of HDAC1/2/3 caused sensitization of melanoma cells to temozolomide in vitro and in melanoma xenografts in vivo HDAC1/2/3 inhibition resulted in suppression of DNA double-strand break (DSB) repair by homologous recombination because of downregulation of RAD51 and FANCD2. This sensitized cells to the cytotoxic DNA lesion O(6)-methylguanine and caused a synthetic lethal interaction with the PARP-1 inhibitor olaparib. Furthermore, knockdown experiments identified HDAC2 as being responsible for the regulation of RAD51. The influence of class I HDACs on DSB repair by homologous recombination and the possible clinical implication on malignant melanoma therapy with temozolomide and other alkylating drugs suggests a combination approach where class I HDAC inhibitors such as valproic acid or MS-275 (entinostat) appear to counteract HDAC- and RAD51/FANCD2-mediated melanoma cell resistance. Cancer Res; 76(10); 3067-77. ©2016 AACR.

  8. Measuring low radium activity concentration in water with RAD7 by means of evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Kappke, Jaqueline; Marussig, Camila G.T.; Paschuk, Sergei; Zambianchi Junior, Pedro; Correa, Janine N.; Perna, Allan Felipe Nunes; Martin, Aline, E-mail: jaquelinekappke@gmail.com, E-mail: mila_garciatb@hotmail.com, E-mail: spaschuk@gmail.com, E-mail: zambianchi@utfpr.edu.br, E-mail: janine_nicolosi@hotmail.com, E-mail: allan_perna@hotmail.com, E-mail: nocamartin@hotmail.com [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil)

    2015-07-01

    Preliminary activity measurements of low radium concentration in mineral water by using RAD7 equipment showed high values of statistical errors. Therefore, the need to develop a new protocol for measuring and proofing the evaporation test for radium measurements in water is in place. This study evaluates the possibility of using RAD7 equipment to measure Ra-226 activity in equilibrium with Rn-222 present in water samples. The technique involves evaporation process so as to increase the Ra-226 concentration in the sample in a controlled manner and thus reduce statistical errors. Two samples were compared, 10 L sample of distilled water and a 7.75 L sample of known concentration (0.1 Bq/L). The evaporation was carried out starting with different initial volumes for both samples: 500 mL, 1000 mL, 2000 mL, 4000 mL and a 250 mL sample not subject to evaporation. All samples reached a final volume of approximately 250 mL. After evaporation, the samples were stored for 30 days until secular equilibrium was achieved between Ra-226 and Rn-222. The values obtained, by using RAD7 detector, for distilled water, as expected, are near zero averaging 0.021 ± 0.016 Bq/L. The average value found in the water of known concentration was 0.099 ± 0.011 Bq/L, also close to the expected 0.1 Bq/L. The conclusion is that the application of an evaporation process is efficient and the proposed methodology is a proven alternative to decrease the statistical errors. (author)

  9. HiRadMat: A high‐energy, pulsed beam, material irradiation facility

    CERN Multimedia

    Charitonidis, Nikolaos

    2016-01-01

    HiRadMat is a facility constructed in 2011, designed to provide high-intensity pulsed beams to an irradiation area where different material samples or accelerator components can be tested. The facility, located at the CERN SPS accelerator complex, uses a 440 GeV proton beam with a pulse length up to 7.2 μs and a maximum intensity up to 1E13 protons / pulse. The facility, a unique place for performing state-of-the art beam-to-material experiments, operates under transnational access and welcomes and financially supports, under certain conditions, experimental teams to perform their experiments.

  10. VIA-RAD: a blackboard-based system for diagnostic radiology. Visual Interaction Assistant for Radiology.

    Science.gov (United States)

    Rogers, E

    1995-08-01

    The work described in this article presents an approach to the integration of computer-displayed radiological images with cooperative computerized assistance for decision-making. The VIA-RAD system (Visual Interaction Assistant for Radiology) is a blackboard-based architecture, founded on extensive data collection and analysis in the domain of diagnostic radiology, together with cognitive modeling of the interaction between perception and problem-solving. The details of this system are presented in terms of domain knowledge representation and domain knowledge mapping. A small prototype of the system has been implemented and tested with radiology subjects, and the results of this study are also described.

  11. Clonagem e caracterização funcional do gene Rad51 de Trypanosoma cruzi

    OpenAIRE

    Carlos Gustavo Regis da Silva

    2002-01-01

    O Trypanosoma cruzi é um parasito pertencente à ordem Kinetoplastida e o agente causador da doença de Chagas. Nesse organismo, é observado um baixo grau de divergência entre alelos. Esse fenômeno é pouco comum em organismos de reprodução clonal como o T. cruzi e ocorre devido a rearranjos gênicos como o processo de recombinação. Esse processo também representa uma das vias de reparo de quebras na dupla fita de DNA. O produto do gene Rad51 é uma das principais proteínas envolvidas nesses proce...

  12. FBH1 influences DNA replication fork stability and homologous recombination through ubiquitylation of RAD51

    DEFF Research Database (Denmark)

    Chu, Wai Kit; Payne, Miranda J; Beli, Petra

    2015-01-01

    Unscheduled homologous recombination (HR) can lead to genomic instability, which greatly increases the threat of neoplastic transformation in humans. The F-box DNA helicase 1 (FBH1) is a 3'-5' DNA helicase with a putative function as a negative regulator of HR. It is the only known DNA helicase...... leads to hyperrecombination, as well as several phenotypes indicative of an altered response to DNA replication stress. These effects are likely to be mediated by the enhanced nuclear matrix association of the ubiquitylation-resistant RAD51. These data are consistent with FBH1 acting as a negative...

  13. Risk stratification of thyroid nodules on ultrasonography with the French TI-RADS: Description and reflections

    Energy Technology Data Exchange (ETDEWEB)

    Russ, Gilles [Thyroid and Endocrine Tumor Unit, Department of Nuclear Medicine, La Pitie Salpetriere Hospital, Pierre and Marie Curie University, Paris (Korea, Republic of)

    2016-01-15

    The widespread use of ultrasonography places it in a key position for use in the risk stratification of thyroid nodules. The French proposal is a five-tier system, our version of a thyroid imaging reporting and database system (TI-RADS), which includes a standardized vocabulary and report and a quantified risk assessment. It allows the selection of the nodules that should be referred for fine-needle aspiration biopsies. Effort should be directed towards merging the different risk stratification systems utilized around the world and testing this unified system with multi-center studies.

  14. High-Resolution Mapping of Homologous Recombination Events in rad3 Hyper-Recombination Mutants in Yeast

    Science.gov (United States)

    Dominska, Margaret; Moriel-Carretero, María; Herrera-Moyano, Emilia; Aguilera, Andrés; Petes, Thomas D.

    2016-01-01

    The Saccharomyces cerevisae RAD3 gene is the homolog of human XPD, an essential gene encoding a DNA helicase of the TFIIH complex involved in both nucleotide excision repair (NER) and transcription. Some mutant alleles of RAD3 (rad3-101 and rad3-102) have partial defects in DNA repair and a strong hyper-recombination (hyper-Rec) phenotype. Previous studies showed that the hyper-Rec phenotype associated with rad3-101 and rad3-102 can be explained as a consequence of persistent single-stranded DNA gaps that are converted to recombinogenic double-strand breaks (DSBs) by replication. The systems previously used to characterize the hyper-Rec phenotype of rad3 strains do not detect the reciprocal products of mitotic recombination. We have further characterized these events using a system in which the reciprocal products of mitotic recombination are recovered. Both rad3-101 and rad3-102 elevate the frequency of reciprocal crossovers about 100-fold. Mapping of these events shows that three-quarters of these crossovers reflect DSBs formed at the same positions in both sister chromatids (double sister-chromatid breaks, DSCBs). The remainder reflects DSBs formed in single chromatids (single chromatid breaks, SCBs). The ratio of DSCBs to SCBs is similar to that observed for spontaneous recombination events in wild-type cells. We mapped 216 unselected genomic alterations throughout the genome including crossovers, gene conversions, deletions, and duplications. We found a significant association between the location of these recombination events and regions with elevated gamma-H2AX. In addition, there was a hotspot for deletions and duplications at the IMA2 and HXT11 genes near the left end of chromosome XV. A comparison of these data with our previous analysis of spontaneous mitotic recombination events suggests that a sub-set of spontaneous events in wild-type cells may be initiated by incomplete NER reactions, and that DSCBs, which cannot be repaired by sister

  15. Site-specific phosphorylation of the DNA damage response mediator rad9 by cyclin-dependent kinases regulates activation of checkpoint kinase 1.

    Directory of Open Access Journals (Sweden)

    Carla Manuela Abreu

    2013-04-01

    Full Text Available The mediators of the DNA damage response (DDR are highly phosphorylated by kinases that control cell proliferation, but little is known about the role of this regulation. Here we show that cell cycle phosphorylation of the prototypical DDR mediator Saccharomyces cerevisiae Rad9 depends on cyclin-dependent kinase (CDK complexes. We find that a specific G2/M form of Cdc28 can phosphorylate in vitro the N-terminal region of Rad9 on nine consensus CDK phosphorylation sites. We show that the integrity of CDK consensus sites and the activity of Cdc28 are required for both the activation of the Chk1 checkpoint kinase and its interaction with Rad9. We have identified T125 and T143 as important residues in Rad9 for this Rad9/Chk1 interaction. Phosphorylation of T143 is the most important feature promoting Rad9/Chk1 interaction, while the much more abundant phosphorylation of the neighbouring T125 residue impedes the Rad9/Chk1 interaction. We suggest a novel model for Chk1 activation where Cdc28 regulates the constitutive interaction of Rad9 and Chk1. The Rad9/Chk1 complex is then recruited at sites of DNA damage where activation of Chk1 requires additional DDR-specific protein kinases.

  16. The recombination protein RAD52 cooperates with the excision repair protein OGG1 for the repair of oxidative lesions in mammalian cells

    DEFF Research Database (Denmark)

    de Souza-Pinto, Nadja C; Maynard, Scott; Hashiguchi, Kazunari;

    2009-01-01

    activities and RAD52 stimulates OGG1 incision activity, likely increasing its turnover rate. RAD52 colocalizes with OGG1 after oxidative stress to cultured cells, but not after the direct induction of double-strand breaks by ionizing radiation. Human cells depleted of RAD52 via small interfering RNA...... to repair oxidative DNA damage and enhances the cellular resistance to oxidative stress. Our observations suggest a coordinated action between these proteins that may be relevant when oxidative lesions positioned close to strand breaks impose a hindrance to RAD52 catalytic activities....

  17. First experimental evidence of hydrodynamic tunneling of ultra–relativistic protons in extended solid copper target at the CERN HiRadMat facility

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, R.; Grenier, D.; Wollmann, D. [CERN-AB, 1211 Geneva 23 (Switzerland); Blanco Sancho, J. [CERN-AB, 1211 Geneva 23, Switzerland and Ecole Polytechnique Federale de Lausanne, Lausanne (Switzerland); Burkart, F. [CERN-AB, 1211 Geneva 23, Switzerland and Goethe University, Frankfurt (Germany); Tahir, N. A. [GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, 64291 Darmstadt (Germany); Shutov, A. [Institute of Problems of Chemical Physics, Chernogolovka (Russian Federation); Piriz, A. R. [E.T.S.I. Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain)

    2014-08-15

    A novel experiment has been performed at the CERN HiRadMat test facility to study the impact of the 440 GeV proton beam generated by the Super Proton Synchrotron on extended solid copper cylindrical targets. Substantial hydrodynamic tunneling of the protons in the target material has been observed that leads to significant lengthening of the projectile range, which confirms our previous theoretical predictions [N. A. Tahir et al., Phys. Rev. Spec. Top.-Accel. Beams 15, 051003 (2012)]. Simulation results show very good agreement with the experimental measurements. These results have very important implications on the machine protection design for powerful machines like the Large Hadron Collider (LHC), the future High Luminosity LHC, and the proposed huge 80 km circumference Future Circular Collider, which is currently being discussed at CERN. Another very interesting outcome of this work is that one may also study the field of High Energy Density Physics at this test facility.

  18. A comprehensive study on the photon energy response of RadFET dosimeters using the PENELOPE Monte Carlo code

    Science.gov (United States)

    Kahraman, A.; Kaya, S.; Jaksic, A.; Yilmaz, E.

    2015-05-01

    Radiation-sensing Field Effect Transistors (RadFETs or MOSFET dosimeters) with SiO2 gate dielectric have found applications in space, radiotherapy clinics, and high-energy physics laboratories. More sensitive RadFETs, which require modifications in device design, including gate dielectric, are being considered for personal dosimetry applications. This paper presents results of a detailed study of the RadFET energy response simulated with PENELOPE Monte Carlo code. Alternative materials to SiO2 were investigated to develop high-efficiency new radiation sensors. Namely, in addition to SiO2, Al2O3 and HfO2 were simulated as gate material and deposited energy amounts in these layers were determined for photon irradiation with energies between 20 keV and 5 MeV. The simulations were performed for capped and uncapped configurations of devices irradiated by point and extended sources, the surface area of which is the same with that of the RadFETs. Energy distributions of transmitted and backscattered photons were estimated using impact detectors to provide information about particle fluxes within the geometrical structures. The absorbed energy values in the RadFETs material zones were recorded. For photons with low and medium energies, the physical processes that affect the absorbed energy values in different gate materials are discussed on the basis of modelling results. The results show that HfO2 is the most promising of the simulated gate materials.

  19. Genetic polymorphism at codon 546 of the human RAD17 contributes to the risk for esophageal squamous cell carcinoma

    Science.gov (United States)

    Yasuda, Yukiko; Sakai, Akiko; Ito, Sachio; Mita, Yuichiro; Sonoyama, Takayuki; Tanabe, Shunsuke; Shirakawa, Yasuhiro; Naomoto, Yoshio; Katayama, Hiroshi; Shimizu, Kenji

    2016-01-01

    Human RAD17, a human homolog of the Schizosaccharomyces pombe cell cycle checkpoint gene RAD17, plays a significant role in activating checkpoint signals in response to DNA damage. We evaluated the association of hRAD17 Leu546Arg (rs1045051), a missense single nucleotide polymorphism, with the risk of esophageal squamous cell carcinoma in relation to smoking and alcohol consumption history in 154 esophageal squamous cell carcinoma male patients and 695 cancer-free male controls by a case-control study conducted in Japan. The results showed that the hRAD17 Arg/Arg genotype compared to the Leu/Leu and Leu/Arg genotypes was significantly associated with the risk of the esophageal squamous cell carcinoma with an adjusted odds ratios of 2.22 (95% CI: 1.19-4.16 P=0.013). In stratified studies, the risk of esophageal squamous cell carcinoma was markedly higher in light drinkers (less than 23 g ethanol/day) with the Arg/Arg genotype than in heavy drinkers (excess of 23 g ethanol/day) with the Arg/Arg genotype (OR=2.83, 95% CI: 1.05-7.61, P=0.04). We concluded that the genetic variant of hRAD17 Leu546Arg polymorphism exerts a significant effect on esophageal squamous cell carcinoma risk among Japanese men. PMID:27186329

  20. VEGF 936C > T Polymorphism and Association of BI-RADS Score in Women with Suspected Breast Cancer

    Directory of Open Access Journals (Sweden)

    M. Wehrschuetz

    2009-10-01

    Full Text Available Purpose: Vascular endothelial growth factor (VEGF is a potent regulator of angiogenesis and thereby involved in the development and progression of solid tumors. A 936C> T polymorphism in the VEGF gene has been associated with reduced VEGF plasma levels. Purpose of the present study was to analyze the potential association between VEGF genotype and radiological appearance of breast lesions by mammography. Materials and Methods: Fifty two women with 54 suspected breast lesions were analyzed by the use of mammography with the standard breast imaging reporting and data systems (BI-RADS. Germline VEGF genotype was determined in all subjects by allele-specific digestion of amplification products. An open biopsy was performed on all lesions. Results: VEGF CC, CT and TT genotypes were found in 41 (79%, 9 (17% and 2 (4% patients. By mammography 26, 16 and 12 suspected breast lesions were classified as BI-RADS scores 3, 4 and 5, respectively. Both carriers of the TT genotype were classified as BI-RADS 5, whereas among CT or CC carriers, BI-RADS scores 3, 4 and 5 were found in 26, 16 and 10 subjects (P T polymorphism seems to be associated with a high BI-RADS score in women with suspicious breast lesions.

  1. Arabidopsis BRCA2 and RAD51 proteins are specifically involved in defense gene transcription during plant immune responses

    Science.gov (United States)

    Wang, Shui; Durrant, Wendy E.; Song, Junqi; Spivey, Natalie W.; Dong, Xinnian

    2010-01-01

    Systemic acquired resistance (SAR) is a plant immune response associated with both transcriptional reprogramming and increased homologous DNA recombination (HR). SNI1 is a negative regulator of SAR and HR, as indicated by the increased basal expression of defense genes and HR in sni1. We found that the sni1 phenotypes are rescued by mutations in BREAST CANCER 2 (BRCA2). In humans, BRCA2 is a mediator of RAD51 in pairing of homologous DNA. Mutations in BRCA2 cause predisposition to breast/ovarian cancers; however, the role of the BRCA2–RAD51 complex in transcriptional regulation remains unclear. In Arabidopsis, both brca2 and rad51 were found to be hypersusceptible not only to genotoxic substances, but also to pathogen infections. A whole-genome microarray analysis showed that downstream of NPR1, BRCA2A is a major regulator of defense-related gene transcription. ChIP demonstrated that RAD51 is specifically recruited to the promoters of defense genes during SAR. This recruitment is dependent on the SAR signal salicylic acid (SA) and on the function of BRCA2. This study provides the molecular evidence showing that the BRCA2–RAD51 complex, known for its function in HR, also plays a direct and specific role in transcription regulation during plant immune responses. PMID:21149701

  2. Failure to induce a DNA repair gene, RAD54, in Saccharomyces cerevisiae does not affect DNA repair or recombination phenotypes

    Energy Technology Data Exchange (ETDEWEB)

    Cole, G.M.; Mortimer, R.K. (Univ. of California, Berkeley (USA))

    1989-08-01

    The Saccharomyces cerevisiae RAD54 gene is transcriptionally regulated by a broad spectrum of DNA-damaging agents. Induction of RAD54 by DNA-damaging agents is under positive control. Sequences responsible for DNA damage induction (the DRS element) lie within a 29-base-pair region from -99 to -70 from the most proximal transcription start site. This inducible promoter element is functionally separable from a poly(dA-dT) region immediately downstream which is required for constitutive expression. Deletions which eliminate induction of RAD54 transcription by DNA damage but do not affect constitutive expression have no effect on growth or survival of noninducible strains relative to wild-type strains in the presence of DNA-damaging agents. The DRS element is also not required for homothallic mating type switching, transcriptional induction of RAD54 during meiosis, meiotic recombination, or spontaneous or X-ray-induced mitotic recombination. We find no phenotype for a lack of induction of RAD54 message via the damage-inducible DRS, which raises significant questions about the physiology of DNA damage induction in S. cerevisiae.

  3. Nanoscopic exclusion between Rad51 and 53BP1 after ion irradiation in human HeLa cells

    Science.gov (United States)

    Reindl, Judith; Drexler, Guido A.; Girst, Stefanie; Greubel, Christoph; Siebenwirth, Christian; Drexler, Sophie E.; Dollinger, Günther; Friedl, Anna A.

    2015-12-01

    Many proteins involved in detection, signalling and repair of DNA double-strand breaks (DSB) accumulate in large number in the vicinity of DSB sites, forming so called foci. Emerging evidence suggests that these foci are sub-divided in structural or functional domains. We use stimulated emission depletion (STED) microscopy to investigate localization of mediator protein 53BP1 and recombination factor Rad51 after irradiation of cells with low linear energy transfer (LET) protons or high LET carbon ions. With a resolution better than 100 nm, STED microscopy and image analysis using a newly developed analyzing algorithm, the reduced product of the differences from the mean, allowed us to demonstrate that with both irradiation types Rad51 occupies spherical regions of about 200 nm diameter. These foci locate within larger 53BP1 accumulations in regions of local 53BP1 depletion, similar to what has been described for the localization of Brca1, CtIP and RPA. Furthermore, localization relative to 53BP1 and size of Rad51 foci was not different after irradiation with low and high LET radiation. As expected, 53BP1 foci induced by low LET irradiation mostly contained one Rad51 focal structure, while after high LET irradiation, most foci contained >1 Rad51 accumulation.

  4. RAD001 enhances the potency of BEZ235 to inhibit mTOR signaling and tumor growth.

    Directory of Open Access Journals (Sweden)

    Beat Nyfeler

    Full Text Available The mammalian target of rapamycin (mTOR is regulated by oncogenic growth factor signals and plays a pivotal role in controlling cellular metabolism, growth and survival. Everolimus (RAD001 is an allosteric mTOR inhibitor that has shown marked efficacy in certain cancers but is unable to completely inhibit mTOR activity. ATP-competitive mTOR inhibitors such as NVP-BEZ235 can block rapamycin-insensitive mTOR readouts and have entered clinical development as anti-cancer agents. Here, we show the degree to which RAD001 and BEZ235 can be synergistically combined to inhibit mTOR pathway activation, cell proliferation and tumor growth, both in vitro and in vivo. RAD001 and BEZ235 synergized in cancer lines representing different lineages and genetic backgrounds. Strong synergy is seen in neuronal, renal, breast, lung, and haematopoietic cancer cells harboring abnormalities in PTEN, VHL, LKB1, Her2, or KRAS. Critically, in the presence of RAD001, the mTOR-4EBP1 pathway and tumorigenesis can be fully inhibited using lower doses of BEZ235. This is relevant since RAD001 is relatively well tolerated in patients while the toxicity profiles of ATP-competitive mTOR inhibitors are currently unknown.

  5. A ddRAD Based Linkage Map of the Cultivated Strawberry, Fragaria xananassa.

    Directory of Open Access Journals (Sweden)

    Jahn Davik

    Full Text Available The cultivated strawberry (Fragaria ×ananassa Duch. is an allo-octoploid considered difficult to disentangle genetically due to its four relatively similar sub-genomic chromosome sets. This has been alleviated by the recent release of the strawberry IStraw90 whole genome genotyping array. However, array resolution relies on the genotypes used in the array construction and may be of limited general use. SNP detection based on reduced genomic sequencing approaches has the potential of providing better coverage in cases where the studied genotypes are only distantly related from the SNP array's construction foundation. Here we have used double digest restriction-associated DNA sequencing (ddRAD to identify SNPs in a 145 seedling F1 hybrid population raised from the cross between the cultivars Sonata (♀ and Babette (♂. A linkage map containing 907 markers which spanned 1,581.5 cM across 31 linkage groups representing the 28 chromosomes of the species. Comparing the physical span of the SNP markers with the F. vesca genome sequence, the linkage groups resolved covered 79% of the estimated 830 Mb of the F. × ananassa genome. Here, we have developed the first linkage map for F. × ananassa using ddRAD and show that this technique and other related techniques are useful tools for linkage map development and downstream genetic studies in the octoploid strawberry.

  6. A ddRAD Based Linkage Map of the Cultivated Strawberry, Fragaria xananassa.

    Science.gov (United States)

    Davik, Jahn; Sargent, Daniel James; Brurberg, May Bente; Lien, Sigbjørn; Kent, Matthew; Alsheikh, Muath

    2015-01-01

    The cultivated strawberry (Fragaria ×ananassa Duch.) is an allo-octoploid considered difficult to disentangle genetically due to its four relatively similar sub-genomic chromosome sets. This has been alleviated by the recent release of the strawberry IStraw90 whole genome genotyping array. However, array resolution relies on the genotypes used in the array construction and may be of limited general use. SNP detection based on reduced genomic sequencing approaches has the potential of providing better coverage in cases where the studied genotypes are only distantly related from the SNP array's construction foundation. Here we have used double digest restriction-associated DNA sequencing (ddRAD) to identify SNPs in a 145 seedling F1 hybrid population raised from the cross between the cultivars Sonata (♀) and Babette (♂). A linkage map containing 907 markers which spanned 1,581.5 cM across 31 linkage groups representing the 28 chromosomes of the species. Comparing the physical span of the SNP markers with the F. vesca genome sequence, the linkage groups resolved covered 79% of the estimated 830 Mb of the F. × ananassa genome. Here, we have developed the first linkage map for F. × ananassa using ddRAD and show that this technique and other related techniques are useful tools for linkage map development and downstream genetic studies in the octoploid strawberry.

  7. Rad Resilient City: a preparedness checklist to save lives following a nuclear detonation.

    Science.gov (United States)

    Schoch-Spana, Monica

    2013-11-01

    The Rad Resilient City Checklist is a local planning tool that can help save tens of thousands of lives following a nuclear detonation. If prevention of nuclear terrorism fails, then reducing exposure to radioactive fallout is the intervention that can save the most lives following a nuclear detonation. Yet, most Americans are not familiar with correct safety measures against fallout, and many believe that nothing can be done to reduce the suffering and death inflicted by a nuclear attack. Moreover, cities have no checklist on how to prepare the emergency management infrastructure and the larger population for this hazard, despite hundreds of pages of useful guidance from the federal government and radiation professional organizations. The Rad Resilient City Checklist reverses this situation by converting the latest federal guidance and technical reports into clear, actionable steps for communities to take to protect their residents from exposure to radioactive fallout. The checklist reflects the shared judgment of the Nuclear Resilience Expert Advisory Group, a national panel led by the Center for Biosecurity and comprised of government decision makers, scientific experts, emergency responders, and leaders from business, volunteer, and community sectors.

  8. The Mre11-Rad50-Xrs2 complex is required for yeast DNA postreplication repair.

    Science.gov (United States)

    Ball, Lindsay G; Hanna, Michelle D; Lambrecht, Amanda D; Mitchell, Bryan A; Ziola, Barry; Cobb, Jennifer A; Xiao, Wei

    2014-01-01

    Yeast DNA postreplication repair (PRR) bypasses replication-blocking lesions to prevent damage-induced cell death. PRR employs two different mechanisms to bypass damaged DNA, namely translesion synthesis (TLS) and error-free PRR, which are regulated via sequential ubiquitination of proliferating cell nuclear antigen (PCNA). We previously demonstrated that error-free PRR utilizes homologous recombination to facilitate template switching. To our surprise, genes encoding the Mre11-Rad50-Xrs2 (MRX) complex, which are also required for homologous recombination, are epistatic to TLS mutations. Further genetic analyses indicated that two other nucleases involved in double-strand end resection, Sae2 and Exo1, are also variably required for efficient lesion bypass. The involvement of the above genes in TLS and/or error-free PRR could be distinguished by the mutagenesis assay and their differential effects on PCNA ubiquitination. Consistent with the observation that the MRX complex is required for both branches of PRR, the MRX complex was found to physically interact with Rad18 in vivo. In light of the distinct and overlapping activities of the above nucleases in the resection of double-strand breaks, we propose that the interplay between distinct single-strand nucleases dictate the preference between TLS and error-free PRR for lesion bypass.

  9. Specific Absorbed Fractions of Electrons and Photons for Rad-HUMAN Phantom Using Monte Carlo Method

    CERN Document Server

    Wang, Wen; Long, Peng-cheng; Hu, Li-qin

    2014-01-01

    The specific absorbed fractions (SAF) for self- and cross-irradiation are effective tools for the internal dose estimation of inhalation and ingestion intakes of radionuclides. A set of SAFs of photon and electron were calculated using the Rad-HUMAN phantom, a computational voxel phantom of Chinese adult female and created using the color photographic image of the Chinese Visible Human (CVH) data set. The model can represent most of Chinese adult female anatomical characteristics and can be taken as an individual phantom to investigate the difference of internal dose with Caucasians. In this study, the emission of mono-energetic photons and electrons of 10keV to 4MeV energy were calculated using the Monte Carlo particle transport calculation code MCNP. Results were compared with the values from ICRP reference and ORNL models. The results showed that SAF from Rad-HUMAN have the similar trends but larger than those from the other two models. The differences were due to the racial and anatomical differences in o...

  10. Mapping of the Gynoecy in Bitter Gourd (Momordica charantia) Using RAD-Seq Analysis

    Science.gov (United States)

    Matsumura, Hideo; Miyagi, Norimichi; Taniai, Naoki; Fukushima, Mai; Tarora, Kazuhiko; Shudo, Ayano; Urasaki, Naoya

    2014-01-01

    Momordica charantia is a monoecious plant of the Cucurbitaceae family that has both male and female unisexual flowers. Its unique gynoecious line, OHB61-5, is essential as a maternal parent in the production of F1 cultivars. To identify the DNA markers for this gynoecy, a RAD-seq (restriction-associated DNA tag sequencing) analysis was employed to reveal genome-wide DNA polymorphisms and to genotype the F2 progeny from a cross between OHB61-5 and a monoecious line. Based on a RAD-seq analysis of F2 individuals, a linkage map was constructed using 552 co-dominant markers. In addition, after analyzing the pooled genomic DNA from monoecious or gynoecious F2 plants, several SNP loci that are genetically linked to gynoecy were identified. GTFL-1, the closest SNP locus to the putative gynoecious locus, was converted to a conventional DNA marker using invader assay technology, which is applicable to the marker-assisted selection of gynoecy in M. charantia breeding. PMID:24498029

  11. Mapping of the gynoecy in bitter gourd (Momordica charantia using RAD-seq analysis.

    Directory of Open Access Journals (Sweden)

    Hideo Matsumura

    Full Text Available Momordica charantia is a monoecious plant of the Cucurbitaceae family that has both male and female unisexual flowers. Its unique gynoecious line, OHB61-5, is essential as a maternal parent in the production of F1 cultivars. To identify the DNA markers for this gynoecy, a RAD-seq (restriction-associated DNA tag sequencing analysis was employed to reveal genome-wide DNA polymorphisms and to genotype the F2 progeny from a cross between OHB61-5 and a monoecious line. Based on a RAD-seq analysis of F2 individuals, a linkage map was constructed using 552 co-dominant markers. In addition, after analyzing the pooled genomic DNA from monoecious or gynoecious F2 plants, several SNP loci that are genetically linked to gynoecy were identified. GTFL-1, the closest SNP locus to the putative gynoecious locus, was converted to a conventional DNA marker using invader assay technology, which is applicable to the marker-assisted selection of gynoecy in M. charantia breeding.

  12. Structure-activity relationship of the peptide binding-motif mediating the BRCA2:RAD51 protein-protein interaction.

    Science.gov (United States)

    Scott, Duncan E; Marsh, May; Blundell, Tom L; Abell, Chris; Hyvönen, Marko

    2016-04-01

    RAD51 is a recombinase involved in the homologous recombination of double-strand breaks in DNA. RAD51 forms oligomers by binding to another molecule of RAD51 via an 'FxxA' motif, and the same recognition sequence is similarly utilised to bind BRCA2. We have tabulated the effects of mutation of this sequence, across a variety of experimental methods and from relevant mutations observed in the clinic. We use mutants of a tetrapeptide sequence to probe the binding interaction, using both isothermal titration calorimetry and X-ray crystallography. Where possible, comparison between our tetrapeptide mutational study and the previously reported mutations is made, discrepancies are discussed and the importance of secondary structure in interpreting alanine scanning and mutational data of this nature is considered.

  13. Modeling the variations of Dose Rate measured by RAD during the first MSL Martian year: 2012-2014

    CERN Document Server

    Guo, Jingnan; Wimmer-Schweingruber, Robert F; Rafkin, Scot; Hassler, Donald M; Posner, Arik; Heber, Bernd; Koehler, Jan; Ehresmann, Bent; Appel, Jan K; Boehm, Eckart; Boettcher, Stephan; Burmeister, Soenke; Brinza, David E; Lohf, Henning; Martin, Cesar; Kahanpaeae, H; Reitz, Guenther

    2015-01-01

    The Radiation Assessment Detector (RAD), on board Mars Science Laboratory's (MSL) rover Curiosity, measures the {energy spectra} of both energetic charged and neutral particles along with the radiation dose rate at the surface of Mars. With these first-ever measurements on the Martian surface, RAD observed several effects influencing the galactic cosmic ray (GCR) induced surface radiation dose concurrently: [a] short-term diurnal variations of the Martian atmospheric pressure caused by daily thermal tides, [b] long-term seasonal pressure changes in the Martian atmosphere, and [c] the modulation of the primary GCR flux by the heliospheric magnetic field, which correlates with long-term solar activity and the rotation of the Sun. The RAD surface dose measurements, along with the surface pressure data and the solar modulation factor, are analysed and fitted to empirical models which quantitatively demonstrate} how the long-term influences ([b] and [c]) are related to the measured dose rates. {Correspondingly we ...

  14. Chromatin architecture may dictate the target site for DMC1, but not for RAD51, during homologous pairing.

    Science.gov (United States)

    Kobayashi, Wataru; Takaku, Motoki; Machida, Shinichi; Tachiwana, Hiroaki; Maehara, Kazumitsu; Ohkawa, Yasuyuki; Kurumizaka, Hitoshi

    2016-04-07

    In eukaryotes, genomic DNA is compacted as chromatin, in which histones and DNA form the nucleosome as the basic unit. DMC1 and RAD51 are essential eukaryotic recombinases that mediate homologous chromosome pairing during homologous recombination. However, the means by which these two recombinases distinctly function in chromatin have remained elusive. Here we found that, in chromatin, the human DMC1-single-stranded DNA complex bypasses binding to the nucleosome, and preferentially promotes homologous pairing at the nucleosome-depleted regions. Consistently, DMC1 forms ternary complex recombination intermediates with the nucleosome-free DNA or the nucleosome-depleted DNA region. Surprisingly, removal of the histone tails improperly enhances the nucleosome binding by DMC1. In contrast, RAD51 does not specifically target the nucleosome-depleted region in chromatin. These are the first demonstrations that the chromatin architecture specifies the sites to promote the homologous recombination reaction by DMC1, but not by RAD51.

  15. Mimivirus reveals Mre11/Rad50 fusion proteins with a sporadic distribution in eukaryotes, bacteria, viruses and plasmids

    Directory of Open Access Journals (Sweden)

    Ogata Hiroyuki

    2011-09-01

    Full Text Available Abstract Background The Mre11/Rad50 complex and the homologous SbcD/SbcC complex in bacteria play crucial roles in the metabolism of DNA double-strand breaks, including DNA repair, genome replication, homologous recombination and non-homologous end-joining in cellular life forms and viruses. Here we investigated the amino acid sequence of the Mimivirus R555 gene product, originally annotated as a Rad50 homolog, and later shown to have close homologs in marine microbial metagenomes. Results Our bioinformatics analysis revealed that R555 protein sequence is constituted from the fusion of an N-terminal Mre11-like domain with a C-terminal Rad50-like domain. A systematic database search revealed twelve additional cases of Mre11/Rad50 (or SbcD/SbcC fusions in a wide variety of unrelated organisms including unicellular and multicellular eukaryotes, the megaplasmid of a bacterium associated to deep-sea hydrothermal vents (Deferribacter desulfuricans and the plasmid of Clostridium kluyveri. We also showed that R555 homologs are abundant in the metagenomes from different aquatic environments and that they most likely belong to aquatic viruses. The observed phyletic distribution of these fusion proteins suggests their recurrent creation and lateral gene transfers across organisms. Conclusions The existence of the fused version of protein sequences is consistent with known functional interactions between Mre11 and Rad50, and the gene fusion probably enhanced the opportunity for lateral transfer. The abundance of the Mre11/Rad50 fusion genes in viral metagenomes and their sporadic phyletic distribution in cellular organisms suggest that viruses, plasmids and transposons played a crucial role in the formation of the fusion proteins and their propagation into cellular genomes.

  16. Misconceptions on Missing Data in RAD-seq Phylogenetics with a Deep-scale Example from Flowering Plants.

    Science.gov (United States)

    Eaton, Deren A R; Spriggs, Elizabeth L; Park, Brian; Donoghue, Michael J

    2016-10-18

    Restriction-site associated DNA (RAD) sequencing and related methods rely on the conservation of enzyme recognition sites to isolate homologous DNA fragments for sequencing, with the consequence that mutations disrupting these sites lead to missing information. There is thus a clear expectation for how missing data should be distributed, with fewer loci recovered between more distantly related samples. This observation has led to a related expectation: that RAD-seq data are insufficiently informative for resolving deeper scale phylogenetic relationships. Here we investigate the relationship between missing information among samples at the tips of a tree and information at edges within it. We re-analyze and review the distribution of missing data across ten RAD-seq data sets and carry out simulations to determine expected patterns of missing information. We also present new empirical results for the angiosperm clade Viburnum (Adoxaceae, with a crown age >50 Ma) for which we examine phylogenetic information at different depths in the tree and with varied sequencing effort. The total number of loci, the proportion that are shared, and phylogenetic informativeness varied dramatically across the examined RAD-seq data sets. Insufficient or uneven sequencing coverage accounted for similar proportions of missing data as dropout from mutation-disruption. Simulations reveal that mutation-disruption, which results in phylogenetically distributed missing data, can be distinguished from the more stochastic patterns of missing data caused by low sequencing coverage. In Viburnum, doubling sequencing coverage nearly doubled the number of parsimony informative sites, and increased by >10X the number of loci with data shared across >40 taxa. Our analysis leads to a set of practical recommendations for maximizing phylogenetic information in RAD-seq studies. [hierarchical redundancy; phylogenetic informativeness; quartet informativeness; Restriction-site associated DNA (RAD

  17. The Saccharomyces cerevisiae Mre11-Rad50-Xrs2 complex promotes trinucleotide repeat expansions independently of homologous recombination.

    Science.gov (United States)

    Ye, Yanfang; Kirkham-McCarthy, Lucy; Lahue, Robert S

    2016-07-01

    Trinucleotide repeats (TNRs) are tandem arrays of three nucleotides that can expand in length to cause at least 17 inherited human diseases. Somatic expansions in patients can occur in differentiated tissues where DNA replication is limited and cannot be a primary source of somatic mutation. Instead, mouse models of TNR diseases have shown that both inherited and somatic expansions can be suppressed by the loss of certain DNA repair factors. It is generally believed that these repair factors cause misprocessing of TNRs, leading to expansions. Here we extend this idea to show that the Mre11-Rad50-Xrs2 (MRX) complex of Saccharomyces cerevisiae is a causative factor in expansions of short TNRs. Mutations that eliminate MRX subunits led to significant suppression of expansions whereas mutations that inactivate Rad51 had only a minor effect. Coupled with previous evidence, this suggests that MRX drives expansions of short TNRs through a process distinct from homologous recombination. The nuclease function of Mre11 was dispensable for expansions, suggesting that expansions do not occur by Mre11-dependent nucleolytic processing of the TNR. Epistasis between MRX and post-replication repair (PRR) was tested. PRR protects against expansions, so a rad5 mutant gave a high expansion rate. In contrast, the mre11 rad5 double mutant gave a suppressed expansion rate, indistinguishable from the mre11 single mutant. This suggests that MRX creates a TNR substrate for PRR. Protein acetylation was also tested as a mechanism regulating MRX activity in expansions. Six acetylation sites were identified in Rad50. Mutation of all six lysine residues to arginine gave partial bypass of a sin3 HDAC mutant, suggesting that Rad50 acetylation is functionally important for Sin3-mediated expansions. Overall we conclude that yeast MRX helps drive expansions of short TNRs by a mechanism distinct from its role in homologous recombination and independent of the nuclease function of Mre11. Copyright

  18. New RAD-Hard STRH3260L6 Bipolar And STRH100N10 Mosfet Power Transistors

    Science.gov (United States)

    Camonita, Giuseppe; Pintacuda, Francesco

    2011-10-01

    This article describes two new power discrete components from STMicroelectronics, specifically offered for Space applications. The STRH3260L6 is a double bipolar rad-hard transistor in an SMD package that houses two complementary devices, one NPN and one PNP. The STRH100N10 is an N-channel rad-hard power MOSFET, the first that is ESCC qualified and available in Europe without procurement restrictions. The purpose of this writing is to give details about the devices' main features, characterization for static, dynamic and radiation performances.

  19. The charged particle radiation environment on Mars measured by MSL/RAD from November 15, 2015 to January 15, 2016

    Science.gov (United States)

    Ehresmann, Bent; Zeitlin, Cary J.; Hassler, Donald M.; Matthiä, Daniel; Guo, Jingnan; Wimmer-Schweingruber, Robert F.; Appel, Jan K.; Brinza, David E.; Rafkin, Scot C. R.; Böttcher, Stephan I.; Burmeister, Sönke; Lohf, Henning; Martin, Cesar; Böhm, Eckart; Reitz, Günther

    2017-08-01

    The Radiation Assessment Detector (RAD) on board the Mars Science Laboratory (MSL) Curiosity rover has been measuring the radiation environment in Gale crater on Mars since August, 2012. These first in-situ measurements provide an important data set for assessing the radiation-associated health risks for future manned missions to Mars. Mainly, the radiation field on the Martian surface stems from Galactic Cosmic Rays (GCRs) and secondary particles created by the GCRs' interactions with the Martian atmosphere and soil. RAD is capable of measuring differential particle fluxes for lower-energy ions and isotopes of hydrogen and helium (up to hundreds of MeV/nuc). Additionally, RAD also measures integral particle fluxes for higher energies of these ions. Besides providing insight on the current Martian radiation environment, these fluxes also present an essential input for particle transport codes that are used to model the radiation to be encountered during future manned missions to Mars. Comparing simulation results with actual ground-truth measurements helps to validate these transport codes and identify potential areas of improvements in the underlying physics of these codes. At the First Mars Radiation Modeling Workshop (June 2016 in Boulder, CO), different groups of modelers were asked to calculate the Martian surface radiation environment for the time of November 15, 2015 to January 15, 2016. These model results can then be compared with in-situ measurements of MSL/RAD conducted during the same time frame. In this publication, we focus on presenting the charged particle fluxes measured by RAD between November 15, 2015 and January 15, 2016, providing the necessary data set for the comparison to model outputs from the modeling workshop. We also compare the fluxes to initial GCR intensities, as well as to RAD measurements from an earlier time period (August 2012 to January 2013). Furthermore, we describe how changes and updates in RAD on board processing and the on

  20. A novel RAD21 variant associated with intrafamilial phenotypic variation in Cornelia de Lange syndrome - review of the literature

    DEFF Research Database (Denmark)

    Boyle, M I; Jespersgaard, C; Nazaryan-Petersen, Lusine

    2017-01-01

    In a patient with CdLS (IV.16) we identifed a novel single basepair deletion (c.704delG) in RAD21, which encodes a cohesin pathway protein. The variant is predicted to result in a premature stop codon [p.(Ser235Ilefs*19)] and hereby would have a deleterious effect. RAD21 variants have previously...... been described only in five cases with cohesinopathies (b). Notably, the deletion was found in the mother and the two aunts of the index patient, and none of them had been suspected of having CdLS or a cohesinopathy prior to this study (a). The index patient can be classified as mild Cd...