126 results on '"Richards, PJ"'
Search Results
2. Numerical Simulation of Sterilization of Non Homogeneous Food Mixture in Cans Using Computational Fluid Dynamics
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Australasian Chemical Engineering Conference (31st : 2003 : Adelaide, S.A.), Abdul Ghani, AG, Farid, MM, and Richards, PJ
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- 2003
3. The Impact of Tail Buildings on the Auckland Wind Environment
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Institution of Professional Engineers New Zealand (1998: Auckland, New Zealand) and Richards, PJ
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- 1998
4. Gaia early data release 3 : Gaia photometric science alerts
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Hodgkin, ST, Harrison, DL, Breedt, E, Wevers, T, Rixon, G, Delgado, A, Yoldas, A, Kostrzewa-Rutkowska, Z, Wyrzykowski, L, Van Leeuwen, M, Blagorodnova, N, Campbell, H, Eappachen, D, Fraser, M, Ihanec, N, Koposov, SE, Kruszyńska, K, Marton, G, Rybicki, KA, Brown, AGA, Burgess, PW, Busso, G, Cowell, S, De Angeli, F, Diener, C, Evans, DW, Gilmore, G, Holland, G, Jonker, PG, Van Leeuwen, F, Mignard, F, Osborne, PJ, Portell, J, Prusti, T, Richards, PJ, Riello, M, Seabroke, GM, Walton, NA, Ábrahám, P, Altavilla, G, Baker, SG, Bastian, U, O'Brien, P, De Bruijne, J, Butterley, T, Carrasco, JM, Castañeda, J, Clark, JS, Clementini, G, Copperwheat, CM, Cropper, M, Damljanovic, G, Davidson, M, Davis, CJ, Dennefeld, M, Dhillon, VS, Dolding, C, Dominik, M, Esquej, P, Eyer, L, Fabricius, C, Fridman, M, Froebrich, D, Garralda, N, Gomboc, A, González-Vidal, JJ, Guerra, R, Hambly, NC, Hardy, LK, Holl, B, Hourihane, A, Japelj, J, Kann, DA, Kiss, C, Knigge, C, Kolb, U, Komossa, S, Kóspál, Kovács, G, Kun, M, Leto, G, Lewis, F, Littlefair, SP, Mahabal, AA, Mundell, CG, Nagy, Z, Padeletti, D, Palaversa, L, Pigulski, A, Pretorius, ML, Van Reeven, W, Ribeiro, VARM, Roelens, M, Rowell, N, Schartel, N, Scholz, A, Schwope, A, Sipocz, BM, Smartt, SJ, and Smith, MD
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Context. Since July 2014, the Gaia mission has been engaged in a high-spatial-resolution, time-resolved, precise, accurate astrometric, and photometric survey of the entire sky.\ud \ud \ud \ud Aims. We present the Gaia Science Alerts project, which has been in operation since 1 June 2016. We describe the system which has been developed to enable the discovery and publication of transient photometric events as seen by Gaia.\ud \ud \ud \ud Methods. We outline the data handling, timings, and performances, and we describe the transient detection algorithms and filtering procedures needed to manage the high false alarm rate. We identify two classes of events: (1) sources which are new to Gaia and (2) Gaia sources which have undergone a significant brightening or fading. Validation of the Gaia transit astrometry and photometry was performed, followed by testing of the source environment to minimise contamination from Solar System objects, bright stars, and fainter near-neighbours.\ud \ud \ud \ud Results. We show that the Gaia Science Alerts project suffers from very low contamination, that is there are very few false-positives. We find that the external completeness for supernovae, CE = 0.46, is dominated by the Gaia scanning law and the requirement of detections from both fields-of-view. Where we have two or more scans the internal completeness is CI = 0.79 at 3 arcsec or larger from the centres of galaxies, but it drops closer in, especially within 1 arcsec.\ud \ud \ud \ud Conclusions. The per-transit photometry for Gaia transients is precise to 1% at G = 13, and 3% at G = 19. The per-transit astrometry is accurate to 55 mas when compared to Gaia DR2. The Gaia Science Alerts project is one of the most homogeneous and productive transient surveys in operation, and it is the only survey which covers the whole sky at high spatial resolution (subarcsecond), including the Galactic plane and bulge.
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- 2021
5. Impact of Terrain Changes on the Central Auckland Wind Environment
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Richards, PJ
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- 1999
6. Gaia Data Release 1: Summary of the astrometric, photometric, and survey properties
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Brown, AGA, Vallenari, A, Prusti, T, De Bruijne, JHJ, Mignard, F, Drimmel, R, Babusiaux, C, Bailer-Jones, CAL, Bastian, U, Biermann, M, Evans, DW, Eyer, L, Jansen, F, Jordi, C, Katz, D, Klioner, SA, Lammers, U, Lindegren, L, Luri, X, O'Mullane, W, Panem, C, Pourbaix, D, Randich, S, Sartoretti, P, Siddiqui, HI, Soubiran, C, Valette, V, Van Leeuwen, F, Walton, NA, Aerts, C, Arenou, F, Cropper, M, Høg, E, Lattanzi, MG, Grebel, EK, Holland, AD, Huc, C, Passot, X, Perryman, M, Bramante, L, Cacciari, C, Castañeda, J, Chaoul, L, Cheek, N, De Angeli, F, Fabricius, C, Guerra, R, Hernández, J, Jean-Antoine-Piccolo, A, Masana, E, Messineo, R, Mowlavi, N, Nienartowicz, K, Ordóñez-Blanco, D, Panuzzo, P, Portell, J, Richards, PJ, Riello, M, Seabroke, GM, Tanga, P, Thévenin, F, Torra, J, Els, SG, Gracia-Abril, G, Comoretto, G, Garcia-Reinaldos, M, Lock, T, Mercier, E, Altmann, M, Andrae, R, Astraatmadja, TL, Bellas-Velidis, I, Benson, K, Berthier, J, Blomme, R, Busso, G, Carry, B, Cellino, A, Clementini, G, Cowell, S, Creevey, O, Cuypers, J, Davidson, M, De Ridder, J, De Torres, A, Delchambre, L, Dell'Oro, A, Ducourant, C, Frémat, Y, García-Torres, M, Gosset, E, Halbwachs, JL, Hambly, NC, Harrison, DL, Hauser, M, Hestroffer, D, Hodgkin, ST, Huckle, HE, Hutton, A, Jasniewicz, G, Evans, Dafydd [0000-0002-6685-5998], van Leeuwen, Floor [0000-0003-1781-4441], Walton, Nicholas [0000-0003-3983-8778], Riello, Marco [0000-0002-3134-0935], Harrison, Diana [0000-0001-8687-6588], Hodgkin, Simon [0000-0002-5470-3962], and Apollo - University of Cambridge Repository
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proper motions ,surveys ,parallaxes ,astrometry ,catalogs - Abstract
At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. We summarize Gaia DR1 and provide illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release. Gaia DR1 consists of: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the Hipparcos and Tycho-2 catalogues and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set,consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of ~3000 Cepheid and RR Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas/yr for the proper motions. A systematic component of ~0.3 mas should be added to the parallax uncertainties. For the subset of ~94000 Hipparcos stars in the primary data set, the proper motions are much more precise at about 0.06 mas/yr. For the secondary astrometric data set, the typical uncertainty of the positions is ~10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to ~0.03 mag over the magnitude range 5 to 20.7. Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data.
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- 2019
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7. The Gaia mission
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Prusti, T, De Bruijne, JHJ, Brown, AGA, Vallenari, A, Babusiaux, C, Bailer-Jones, CAL, Bastian, U, Biermann, M, Evans, DW, Eyer, L, Jansen, F, Jordi, C, Klioner, SA, Lammers, U, Lindegren, L, Luri, X, Mignard, F, Milligan, DJ, Panem, C, Poinsignon, V, Pourbaix, D, Randich, S, Sarri, G, Sartoretti, P, Siddiqui, HI, Soubiran, C, Valette, V, Van Leeuwen, F, Walton, NA, Aerts, C, Arenou, F, Cropper, M, Drimmel, R, Høg, E, Katz, D, Lattanzi, MG, O'Mullane, W, Grebel, EK, Holland, AD, Huc, C, Passot, X, Bramante, L, Cacciari, C, Castañeda, J, Chaoul, L, Cheek, N, De Angeli, F, Fabricius, C, Guerra, R, Hernández, J, Jean-Antoine-Piccolo, A, Masana, E, Messineo, R, Mowlavi, N, Nienartowicz, K, Ordóñez-Blanco, D, Panuzzo, P, Portell, J, Richards, PJ, Riello, M, Seabroke, GM, Tanga, P, Thévenin, F, Torra, J, Els, SG, Gracia-Abril, G, Comoretto, G, Garcia-Reinaldos, M, Lock, T, Mercier, E, Altmann, M, Andrae, R, Astraatmadja, TL, Bellas-Velidis, I, Benson, K, Berthier, J, Blomme, R, Busso, G, Carry, B, Cellino, A, Clementini, G, Cowell, S, Creevey, O, Cuypers, J, Davidson, M, De Ridder, J, De Torres, A, Delchambre, L, Dell'Oro, A, Ducourant, C, Frémat, Y, García-Torres, M, Gosset, E, Halbwachs, JL, Hambly, NC, Harrison, DL, Hauser, M, Hestroffer, D, Hodgkin, ST, Huckle, HE, Evans, Dafydd [0000-0002-6685-5998], van Leeuwen, Floor [0000-0003-1781-4441], Walton, Nicholas [0000-0003-3983-8778], Riello, Marco [0000-0002-3134-0935], Harrison, Diana [0000-0001-8687-6588], Hodgkin, Simon [0000-0002-5470-3962], and Apollo - University of Cambridge Repository
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proper motions ,parallaxes ,astrometry ,telescopes ,space vehicles: instruments ,Galaxy: structure - Abstract
Gaia is a cornerstone mission in the science programme of the European Space Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to a direct-imaging approach. Both the spacecraft and the payload were built by European industry. The involvement of the scientific community focusses on data processing for which the international Gaia Data Processing and Analysis Consortium (DPAC) was selected in 2007. Gaia was launched on 19 December 2013 and arrived at its operating point, the second Lagrange point of the Sun-Earth-Moon system, a few weeks later. The commissioning of the spacecraft and payload was completed on 19 July 2014. The nominal five-year mission started with four weeks of special, ecliptic-pole scanning and subsequently transferred into full-sky scanning mode. We recall the scientific goals of Gaia and give a description of the as-built spacecraft that is currently (mid-2016) being operated to achieve these goals. We pay special attention to the payload module, the performance of which is closely related to the scientific performance of the mission. We provide a summary of the commissioning activities and findings, followed by a description of the routine operational mode. We summarise scientific performance estimates on the basis of in-orbit operations. Several intermediate Gaia data releases are planned and the data can be retrieved from the Gaia Archive, which is available through the Gaia home page at http://www.cosmos.esa.int/gaia.
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- 2018
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8. Gaia Data Release 1: Testing parallaxes with local Cepheids and RR Lyrae stars
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Clementini, G, Eyer, L, Ripepi, V, Marconi, M, Muraveva, T, Garofalo, A, Sarro, LM, Palmer, M, Luri, X, Molinaro, R, Rimoldini, L, Szabados, L, Musella, I, Anderson, RI, Prusti, T, De Bruijne, JHJ, Brown, AGA, Vallenari, A, Babusiaux, C, Bailer-Jones, CAL, Bastian, U, Biermann, M, Evans, DW, Jansen, F, Jordi, C, Klioner, SA, Lammers, U, Lindegren, L, Mignard, F, Panem, C, Pourbaix, D, Randich, S, Sartoretti, P, Siddiqui, HI, Soubiran, C, Valette, V, Van Leeuwen, F, Walton, NA, Aerts, C, Arenou, F, Cropper, M, Drimmel, R, Høg, E, Katz, D, Lattanzi, MG, O'Mullane, W, Grebel, EK, Holland, AD, Huc, C, Passot, X, Perryman, M, Bramante, L, Cacciari, C, Castañeda, J, Chaoul, L, Cheek, N, De Angeli, F, Fabricius, C, Guerra, R, Hernández, J, Jean-Antoine-Piccolo, A, Masana, E, Messineo, R, Mowlavi, N, Nienartowicz, K, Ordóñez-Blanco, D, Panuzzo, P, Portell, J, Richards, PJ, Riello, M, Seabroke, GM, Tanga, P, Thévenin, F, Torra, J, Els, SG, Gracia-Abril, G, Comoretto, G, Garcia-Reinaldos, M, Lock, T, Mercier, E, Altmann, M, Andrae, R, Astraatmadja, TL, Bellas-Velidis, I, Benson, K, Berthier, J, Blomme, R, Busso, G, Carry, B, Cellino, A, Cowell, S, Evans, Dafydd [0000-0002-6685-5998], van Leeuwen, Floor [0000-0003-1781-4441], Walton, Nicholas [0000-0003-3983-8778], Riello, Marco [0000-0002-3134-0935], and Apollo - University of Cambridge Repository
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stars: variables: RR Lyrae ,parallaxes ,stars: distances ,astrometry ,methods: data analysis ,stars: variables: Cepheids - Abstract
Context. Parallaxes for 331 classical Cepheids, 31 Type II Cepheids, and 364 RR Lyrae stars in common between Gaia and the Hipparcos and Tycho-2 catalogues are published in Gaia Data Release 1 (DR1) as part of the Tycho-Gaia Astrometric Solution (TGAS). Aims. In order to test these first parallax measurements of the primary standard candles of the cosmological distance ladder, which involve astrometry collected by Gaia during the initial 14 months of science operation, we compared them with literature estimates and derived new period-luminosity (PL), period-Wesenheit (PW) relations for classical and Type II Cepheids and infrared PL, PL-metallicity (PLZ), and optical luminosity-metallicity (M V -[Fe/H]) relations for the RR Lyrae stars, with zero points based on TGAS. Methods. Classical Cepheids were carefully selected in order to discard known or suspected binary systems. The final sample comprises 102 fundamental mode pulsators with periods ranging from 1.68 to 51.66 days (of which 33 with σ Ω /Ω < 0.5). The Type II Cepheids include a total of 26 W Virginis and BL Herculis stars spanning the period range from 1.16 to 30.00 days (of which only 7 with σ Ω /Ω < 0.5). The RR Lyrae stars include 200 sources with pulsation period ranging from 0.27 to 0.80 days (of which 112 with σ Ω /Ω < 0.5). The new relations were computed using multi-band (V,I,J,K s ) photometry and spectroscopic metal abundances available in the literature, and by applying three alternative approaches: (i) linear least-squares fitting of the absolute magnitudes inferred from direct transformation of the TGAS parallaxes; (ii) adopting astrometry-based luminosities; and (iii) using a Bayesian fitting approach. The last two methods work in parallax space where parallaxes are used directly, thus maintaining symmetrical errors and allowing negative parallaxes to be used. The TGAS-based PL,PW,PLZ, and M V - [Fe/H] relations are discussed by comparing the distance to the Large Magellanic Cloud provided by different types of pulsating stars and alternative fitting methods. Results. Good agreement is found from direct comparison of the parallaxes of RR Lyrae stars for which both TGAS and HST measurements are available. Similarly, very good agreement is found between the TGAS values and the parallaxes inferred from the absolute magnitudes of Cepheids and RR Lyrae stars analysed with the Baade-Wesselink method. TGAS values also compare favourably with the parallaxes inferred by theoretical model fitting of the multi-band light curves for two of the three classical Cepheids and one RR Lyrae star, which were analysed with this technique in our samples. The K-band PL relations show the significant improvement of the TGAS parallaxes for Cepheids and RR Lyrae stars with respect to the Hipparcos measurements. This is particularly true for the RR Lyrae stars for which improvement in quality and statistics is impressive. Conclusions. TGAS parallaxes bring a significant added value to the previous Hipparcos estimates. The relations presented in this paper represent the first Gaia-calibrated relations and form a work-in-progress milestone report in the wait for Gaia-only parallaxes of which a first solution will become available with Gaia Data Release 2 (DR2) in 2018., This work has made use of results from the European Space Agency (ESA) space mission Gaia, the data from which were processed by the Gaia Data Processing and Analysis Consortium (DPAC). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. The Gaia mission website is http://www.cosmos.esa.int/gaia. The authors are current or past members of the ESA and Airbus DS Gaia mission teams and of the Gaia DPAC. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France. We thank the referee, Pierre Kervella, for his detailed comments and suggestions that have helped to improve the paper analysis and presentation. This work has financially been supported by: the Agenzia Spaziale Italiana (ASI) through grants I/037/08/0, I/058/10/0, 2014-025-R.0, and 2014-025-R.1.2015 to INAF and contracts I/008/10/0 and 2013/030/I.0 to ALTEC S.p.A.; the Algerian Centre de Recherche en Astronomie, Astrophysique et Géophysique of Bouzareah Observatory; the Austrian FWF Hertha Firnberg Programme through grants T359, P20046, and P23737; the BELgian federal Science Policy Office (BELSPO) through various PROgramme de Développement d’Expériences scientifiques (PRODEX) grants; the Brazil-France exchange programmes FAPESP-COFECUB and CAPES-COFECUB; the Chinese National Science Foundation through grant NSFC 11573054; the Czech-Republic Ministry of Education, Youth, and Sports through grant LG 15010; the Danish Ministry of Science; the Estonian Ministry of Education and Research through grant IUT40-1; the European Commission’s Sixth Framework Programme through the European Leadership in Space Astrometry (ELSA) Marie Curie Research Training Network (MRTN-CT-2006-033481), through Marie Curie project PIOF-GA-2009-255267 (SAS-RRL), and through a Marie Curie Transfer-of-Knowledge (ToK) fellowship (MTKD-CT-2004-014188); the European Commission’s Seventh Framework Programme through grant FP7-606740 (FP7-SPACE-2013-1) for the Gaia European Network for Improved data User Services (GENIUS) and through grant 264895 for the Gaia Research for European Astronomy Training (GREAT-ITN) network; the European Research Council (ERC) through grant 320360 and through the European Union’s Horizon 2020 research and innovation programme through grant agreement 670519 (Mixing and Angular Momentum tranSport of massIvE stars – MAMSIE); the European Science Foundation (ESF), in the framework of the Gaia Research for European Astronomy Training Research Network Programme (GREAT-ESF); the European Space Agency in the framework of the Gaia project; the European Space Agency Plan for European Cooperating States (PECS) programme through grants for Slovenia; the Czech Space Office through ESA PECS contract 98058; the Academy of Finland; the Magnus Ehrnrooth Foundation; the French Centre National de la Recherche Scientifique (CNRS) through action “Défi MASTODONS”; the French Centre National d’Études Spatiales (CNES); the French L’Agence Nationale de la Recherche (ANR) “investissements d’avenir” Initiatives D’EXcellence (IDEX) programme PSL∗ through grant ANR-10-IDEX-0001-02; the Région Aquitaine; the Université de Bordeaux; the French Utinam Institute of the Université de Franche-Comté, supported by the Région de Franche-Comté and the Institut des Sciences de l’Univers (INSU); the German Aerospace Agency (Deutsches Zentrum für Luft- und Raumfahrt e.V., DLR) through grants 50QG0501, 50QG0601, 50QG0602, 50QG0701, 50QG0901, 50QG1001, 50QG1101, 50QG140, 50QG1401, 50QG1402, and 50QG1404; the Hungarian Academy of Sciences through Lendület Programme LP2014-17; the Hungarian National Research, Development, and Innovation Office through grants NKFIH K-115709, K-119517 and PD-116175; the Israel Ministry of Science and Technology through grant 3-9082; the Italian Istituto Nazionale di Astrofisica (INAF); the Netherlands Organisation for Scientific Research (NWO) through grant NWO-M-614.061.414 and through a VICI grant to A. Helmi; the Netherlands Research School forAstronomy (NOVA); the Polish National Science Centre through HARMONIA grant 2015/18/M/ST9/00544; the Portugese Fundação para a Ciência e a Tecnologia (FCT) through grants PTDC/CTE-SPA/118692/2010, PDCTE/CTE-AST/81711/2003, and SFRH/BPD/74697/2010; the Strategic Programmes PEst-OE/AMB/UI4006/2011 for SIM, UID/FIS/00099/2013 for CENTRA, and UID/EEA/00066/2013 for UNINOVA; the Slovenian Research Agency; the Spanish Ministry of Economy MINECO-FEDER through grants AyA2014-55216, AyA2011-24052, ESP2013-48318-C2-R, and ESP2014-55996-C2-R and MDM-2014-0369 of ICCUB (Unidad de Excelencia María de Maeztu); the Swedish National Space Board (SNSB/Rymdstyrelsen); the Swiss State Secretariat for Education, Research, and Innovation through the ESA PRODEX programme; the Swiss Mesures d’Accompagnement; the Swiss Activités Nationales Complémentaires; the Swiss National Science Foundation, including an Early Postdoc.Mobility fellowship; the United Kingdom Rutherford Appleton Laboratory; the United Kingdom Science and Technology Facilities Council (STFC) through grants PP/C506756/1 and ST/I00047X/1; and the United Kingdom Space Agency (UKSA) through grants ST/K000578/1 and ST/N000978/1.
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- 2017
9. A bound for solutions of a fourth order dynamical system
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Pagan, G, Richards, PJ, Everitt, W. N., editor, and Sleeman, B. D., editor
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- 1981
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10. A bound for solutions of a fourth order dynamical system
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Pagan, G, primary and Richards, PJ, additional
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- 1981
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11. In vitro und ex vivo Effekt von Bisphosphonaten auf das osteogene Differenzierungspotential mesenchymaler Stammzellen osteoporotischer Hüftfrakturpatienten
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Lindtner, RA, Tiaden, AN, Genelin, K, Ebner, HL, Sitte, I, Blauth, M, von Rechenberg, B, Richards, PJ, Lindtner, RA, Tiaden, AN, Genelin, K, Ebner, HL, Sitte, I, Blauth, M, von Rechenberg, B, and Richards, PJ
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- 2013
12. Ankle fractures and dislocations: A pictorial review
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Richards, PJ, primary, Charran, AK, additional, Singhal, R, additional, and McBride, DJ, additional
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- 2013
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13. Surgical interventions for treating ankle fractures
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Robert, IE, primary, Krikler, S, additional, Richards, PJ, additional, Bridgman, S, additional, and Simons, A, additional
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- 2005
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14. Interventions for treating calcaneal fractures
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Bridgman, SA, primary, Dunn, KM, additional, McBride, DJ, additional, and Richards, PJ, additional
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- 1999
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15. Surgical interventions for treating ankle fractures
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Robert, IE, primary, Krikler, S, additional, Richards, PJ, additional, Bridgman, S, additional, and Simons, A, additional
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- 1999
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16. The imaging and management of nonconsecutive pars interarticularis defects: a case report and review of literature.
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Nayeemuddin M, Richards PJ, and Ahmed EB
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- 2011
17. Angiographic embolisation of pelvic ring injuries. Treatment algorithm and review of the literature.
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Karadimas EJ, Nicolson T, Kakagia DD, Matthews SJ, Richards PJ, Giannoudis PV, Karadimas, Efthimios J, Nicolson, Tony, Kakagia, Despoina D, Matthews, Stuart J, Richards, Paula J, and Giannoudis, Peter V
- Abstract
Purpose: The purpose of this study was to evaluate the relation between pelvic fracture patterns and the angiographic findings, and to assess the effectiveness of the embolisation.Methods: This retrospective study, included patients with pelvic fractures and angiographic evaluation. Demographics, Injury Severity Score (ISS), associated injuries, embolisation time, blood units needed, method of treatment and complications were recorded and analysed. Fractures were classified according to the Burgess system.Results: Between 1998 and 2008, 34 patients with pelvic fractures underwent angiographic investigation. Twenty six were males. The mean age was 41 years. Twenty-seven were motor vehicle accidents and seven were falls. There were 11 anterior posterior (APC) fractures, 12 lateral compression (LC), eight vertical shear (VS) patterns and three with combined mechanical injuries. The median ISS was 33.1 (range 5-66). From the 34 who underwent angiography, 29 had positive vascular extravasations. From them, 21 had embolisation alone, two had vascular repair and embolisation, five required vascular repair alone and one patient died while being prepared for embolisation. Five cases were re-embolised. The findings suggested that AP fractures have a higher tendency to bleeding compared with LC fractures. Both had a higher chance of blood loss compared to VS and complex fracture patterns. We reported 57 additional injuries and 65 fractures. The complications were: one non lethal pulmonary embolism, one renal failure, one liver failure, one systemic infection, two deep infections and two psychological disorientations. Seven patients died in hospital.Conclusion: Control of pelvic fracture bleeding is based on the multidisciplinary approach mainly related to hospital facilities and medical personnel's awareness. The morphology of the fracture did not have a predictive value of the vascular lesion and the respective bleeding. [ABSTRACT FROM AUTHOR]- Published
- 2011
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18. Correction and prevention of deformity in type II tibialis posterior dysfunction.
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Parsons S, Naim S, Richards PJ, McBride D, Parsons, Stephen, Naim, Soulat, Richards, Paula J, and McBride, Donald
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Unlabelled: Cobb described a method of reconstruction in Johnson and Strom Type II tibialis posterior dysfunction (TPD) using a split tibialis anterior musculotendinous graft. We assessed patient function and satisfaction after a modified Cobb reconstruction in a group of patients with a narrow spectrum of dysfunction, examined a modification of the Johnson and Strom classification to emphasize severity of deformity, and assessed the ability of the technique to prevent subsequent fixed deformity. We prospectively followed 32 patients managed by this technique and a translational os calcis osteotomy with early flexible deformity after failed conservative treatment. There were 28 women and four men with unilateral disease. The average followup was 5.1 years. Staging was confirmed clinically and with imaging. The modified surgery involved a bone tunnel in the navicular rather than the medial cuneiform with plaster for 8 weeks followed by orthotics and physiotherapy. All of the osteotomies healed and 29 of the 32 patients could perform a single heel rise test at 12 months. The mean postoperative American Orthopaedic Foot and Ankle Society hindfoot score was 89. One patient had a superficial wound infection and one a temporary dysesthesia of the medial plantar nerve; both resolved. The observations suggest the technique is a comparable method of treating early Johnson and Strom Type II TPD.Level Of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]- Published
- 2010
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19. Achilles tendon ossification: pathology, imaging and aetiology.
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Richards PJ, Braid JC, Carmont MR, and Maffulli N
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Background. We report a patient with ossification of the Achilles tendon, presenting plain radiographs, ultrasound, power doppler, computed tomography and magnetic resonance findings. The majority of the tendon was ossified, and there was adjacent soft tissue oedema. The appearance of peritendinous oedema associated with ossification has not, to our knowledge, been reported in the literature, and could account for hindfoot pain in cases of tendon ossification. Method. A review of 44 articles on aetiology, histology and imaging was performed. Results. Trauma, either accidental or from surgery, rather than tendinopathy is the likely aetiological factor. Conclusion. The Achilles tendon usually responds to an insult with the development of mature bone, not dystrophic calcification, with no evidence of inflammatory or degenerative changes. [ABSTRACT FROM AUTHOR]
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- 2008
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20. Major trauma & cervical clearance radiation doses & cancer induction.
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Richards PJ, Summerfield R, George J, Hamid A, Oakley P, Richards, Paula J, Summerfield, Ruth, George, Jennifer, Hamid, Amr, and Oakley, Peter
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Aim: To compare the radiation dose of cervical spine clearance and body CT in a cohort of unconscious, major trauma patients for three different protocols, comparing spiral to multislice CT. To quantify the radiation exposure effect of the protocols on the lifetime cancer risk.Method: The hospital trauma database was used to find the unconscious (GCS<9), severely injured (Injury Severity Score >15) from 1 January 2001 to 31 December 2003, excluding isolated head injuries. The protocols used for imaging the brain and cervical spine were, including the radiographs performed as a mode: The exposure factors and field of view used were put into the Monte Carlo software, to estimate the CT and radiographic X-ray doses to the body as a whole and the dose to the thyroid associated with each region imaged. The associated nominal additional lifetime cancer risk was assessed.Results: Excluding inter hospital transfers, where data was incomplete, 87 patients survived to be admitted and fulfilled the criteria. In 30 cases, the CT films were missing, the exposure factors were not recorded or no imaging was performed. In a further 21 cases, the X-ray packets were missing. Three patients had brain and cervico-dorsal CT imaging only, leaving 33 cases for evaluation. The effective radiation dose for a spiral CT of the brain using the Toshiba Xpress GX CT scanner was 3.8 mSv. The total effective doses for imaging the brain and cervical spine using the three protocols with the same CT scanner were (S.D. as % of mean): (1) 4.4 mSv (5%), (2) 7.1 mSv (10%) and (3) 8.2 mSv (15%). The corresponding mean thyroid doses were: (1) 8.5 mGy (25%), (2) 48.9 mGy (20%) and (3) 66.5 mSv (20%). The resultant nominal lifetime cancer risks were: (1) 1:4500, (2) 1:2800 and (3) 1:2400. For the Siemens Sensation 16 multislice CT scanner, the total effective doses (S.D. as % of mean) were: (1) 2.3 mSv (10%), (2) 4.3 mSv (25%) and (3) 5.4 mSv (35%). The mean doses to the thyroid were: (1) 5.9 mGy (30%), (2) 36.1 mGy (50%) and (3) 52.4 mGy (40%). The lifetime cancer risks were: (1) 1:8700, (2) 1:4600 and (3) 1:3700. Using the Toshiba spiral CT scanner, the total dose and additional lifetime nominal cancer risk associated with CT of the chest, abdomen and pelvis (CAP) as 16 mSv and 1:1250, respectively. Using the Siemens multislice CT scanner, these were 11.8 mSv and 1:1700. The cancer risk for protocol 1 when combined with a CT scan of the chest, abdomen and pelvis was 1:1000 for the spiral CT scanner and 1:1500 for the multislice CT (MCT) scanner. The cancer risk for protocol 2 with CAP CT using the MCT was 1:1200. The cancer risk for protocol 3 when combined with a CT scan of the chest, abdomen and pelvis was 1:1100 for the multislice CT scanner. Prior to the introduction of the BTS guidelines for cervical clearance, 12% of cases had CT of the body, which increased to 16% post-guidelines.Conclusions: CT of the trunk (chest, abdomen and pelvis) is associated with the greatest risk of inducing a fatal cancer in the severely injured patient with a GCS less than 9. In our institution the multislice CT protocols expose the patient to less radiation than single slice CT, which is contrary to much of the published work to date. CT scanning the thyroid (or whole cervical spine) still has a marked effect on the cancer risk in cervical clearance. Many centres will relax cervical spinal precautions in unconscious trauma patients if the cervical spine CT with reconstructions is normal. CT of the whole cervical spine may be justified in the unconscious, severely injured patient. In conscious trauma patients, the additional lifetime risk may not justify CT of the whole cervical spine as a routine practice. [ABSTRACT FROM AUTHOR]- Published
- 2008
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21. Regulation of pre-B cell colony-enhancing factor by STAT-3-dependent interleukin-6 trans-signaling: implications in the pathogenesis of rheumatoid arthritis.
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Nowell MA, Richards PJ, Fielding CA, Ognjanovic S, Topley N, Williams AS, and Bryant-Greenwood G
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- 2006
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22. Liposomal clodronate eliminates synovial macrophages, reduces inflammation and ameliorates joint destruction in antigen-induced arthritis.
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Richards, PJ, Williams, AS, Goodfellow, RM, and Williams, BD
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- 1999
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23. Gaia Release Dataa 2 Summary of the contents and survey properties
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Brown, AGA, Vallenari, A, Prusti, T, de Bruijne, JHJ, Babusiaux, C, Bailer-Jones, CAL, Biermann, M, Evans, DW, Eyer, L, Jansen, F, Jordi, C, Klioner, SA, Lammers, U, Lindegren, L, Luri, X, Mignard, F, Panem, C, Pourbaix, D, Randich, S, Sartoretti, P, Siddiqui, HI, Soubiran, C, van Leeuwen, F, Walton, NA, Arenou, F, Bastian, U, Cropper, M, Drimmel, R, Katz, D, Lattanzi, MG, Bakker, J, Cacciari, C, Castaneda, J, Chaoul, L, Cheek, N, De Angeli, F, Fabricius, C, Guerra, R, Holl, B, Masana, E, Messineo, R, Mowlavi, N, Nienartowicz, K, Panuzzo, P, Portell, J, Riello, M, Seabroke, GM, Tanga, P, Thevenin, F, Gracia-Abril, G, Comoretto, G, Garcia-Reinaldos, M, Teyssier, D, Altmann, M, Andrae, R, Audard, M, Bellas-Velidis, I, Benson, K, Berthier, J, Blomme, R, Burgess, P, Busso, G, Carry, B, Cellino, A, Clementini, G, Clotet, M, Creevey, O, Davidson, M, De Ridder, J, Delchambre, L, Dell'Oro, A, Ducourant, C, Fernandez-Hernandez, J, Fouesneau, M, Fremat, Y, Galluccio, L, Garcia-Torres, M, Gonzalez-Nunez, J, Gonzalez-Vidal, JJ, Gosset, E, Guy, LP, Halbwachs, J-L, Hambly, NC, Harrison, DL, Hernandez, J, Hestroffer, D, Hodgkin, ST, Hutton, A, Jasniewicz, G, Jean-Antoine-Piccolo, A, Jordan, S, Korn, AJ, Krone-Martins, A, Lanzafame, AC, Lebzelter, T, Loeffler, W, Manteiga, M, Marrese, PM, Martin-Fleitas, JM, Moitinho, A, Mora, A, Muinonen, K, Osinde, J, Pancino, E, Pauwels, T, Petit, J-M, Recio-Blanco, A, Richards, PJ, Rimoldini, L, Robin, AC, Sarro, LM, Siopis, C, Smith, M, Sozzetti, A, Sueveges, M, Torra, J, van Reeven, W, Abbas, U, Aramburu, AA, Accart, S, Aerts, C, Altavilla, G, Alvarez, MA, Alvarez, R, Alves, J, Anderson, RI, Andrei, AH, Anglada Varela, E, Antiche, E, Antoja, T, Arcay, B, Astraatmadja, TL, Bach, N, Baker, SG, Balaguer-Nunez, L, Balm, P, Barache, C, Barata, C, Barbato, D, Barblan, F, Barklem, PS, Barrado, D, Barros, M, Barstow, MA, Bartholome Munoz, S, Bassilana, J-L, Becciani, U, Bellazzini, M, Berihuete, A, Bertone, S, Bianchi, L, Bienayme, O, Blanco-Cuaresma, S, Boch, T, Boeche, C, Bombrun, A, Borrachero, R, Bossini, D, Bouquillon, S, Bourda, G, Bragaglia, A, Bramante, L, Breddels, MA, Bressan, A, Brouillet, N, Bruesemeister, T, Brugaletta, E, Bucciarelli, B, Burlacu, A, Busonero, D, Butkevich, AG, Buzzi, R, Caffau, E, Cancelliere, R, Cannizzaro, G, Cantat-Gaudin, T, Carballo, R, Carlucci, T, Carrasco, JM, Casamiquela, L, Castellani, M, Castro-Ginard, A, Charlot, P, Chemin, L, Chiavassa, A, Cocozza, G, Costigan, G, Cowell, S, Crifo, F, Crosta, M, Crowley, C, Cuypers, J, Dafonte, C, Damerdji, Y, Dapergolas, A, David, P, David, M, de Laverny, P, De Luise, F, De March, R, de Martino, D, de Souza, R, de Torres, A, Debosscher, J, del Pozo, E, Delbo, M, Delgado, A, Delgado, HE, Di Matteo, P, Diakite, S, Diener, C, Distefano, E, Dolding, C, Drazinos, P, Duran, J, Edvardsson, B, Enke, H, Eriksson, K, Esquej, P, Eynard Bontemps, G, Fabre, C, Fabrizio, M, Faigler, S, Falcao, AJ, Farras Casas, M, Federici, L, Fedorets, G, Fernique, P, Figueras, F, Filippi, F, Findeisen, K, Fonti, A, Fraile, E, Fraser, M, Frezouls, B, Gai, M, Galleti, S, Garabato, D, Garcia-Sedano, F, Garofalo, A, Garralda, N, Gavel, A, Gavras, P, Gerssen, J, Geyer, R, Giacobbe, P, Gilmore, G, Girona, S, Giuffrida, G, Glass, F, Gomes, M, Granvik, M, Gueguen, A, Guerrier, A, Guiraud, J, Gutierrez-Sanchez, R, Haigron, R, Hatzidimitriou, D, Hauser, M, Haywood, M, Heiter, U, Helmi, A, Heu, J, Hilger, T, Hobbs, D, Hofmann, W, Holland, G, Huckle, HE, Hypki, A, Icardi, V, Janssen, K, Jevardat de Fombelle, G, Jonker, PG, Juhasz, AL, Julbe, F, Karampelas, A, Kewley, A, Klar, J, Kochoska, A, Kohley, R, Kolenberg, K, Kontizas, M, Kontizas, E, Koposov, SE, Kordopatis, G, Kostrzewa-Rutkowska, Z, Koubsky, P, Lambert, S, Lanza, AF, Lasne, Y, Lavigne, J-B, Le Fustec, Y, Le Poncin-Lafitte, C, Lebreton, Y, Leccia, S, Leclerc, N, Lecoeur-Taibi, I, Lenhardt, H, Leroux, F, Liao, S, Licata, E, Lindstrom, HEP, Lister, TA, Livanou, E, Lobel, A, Lopez, M, Managau, S, Mann, RG, Mantelet, G, Marchal, O, Marchant, JM, Marconi, M, Marinoni, S, Marschalko, G, Marshall, DJ, Martino, M, Marton, G, Mary, N, Massari, D, Matijevic, G, Mazeh, T, McMillan, PJ, Messina, S, Michalik, D, Millar, NR, Molina, D, Molinaro, R, Molnar, L, Montegriffo, P, Mor, R, Morbidelli, R, Morel, T, Morris, D, Mulone, AF, Muraveva, T, Musella, I, Nelemans, G, Nicastro, L, Noval, L, O'Mullane, W, Ordenovic, C, Ordonez-Blanco, D, Osborne, P, Pagani, C, Pagano, I, Pailler, F, Palacin, H, Palaversa, L, Panahi, A, Pawlak, M, Piersimoni, AM, Pineau, F-X, Plachy, E, Plum, G, Poggio, E, Poujoulet, E, Prsa, A, Pulone, L, Racero, E, Ragaini, S, Rambaux, N, Ramos-Lerate, M, Regibo, S, Reyle, C, Riclet, F, Ripepi, V, Riva, A, Rivard, A, Rixon, G, Roegiers, T, Roelens, M, Romero-Gomez, M, Rowell, N, Royer, F, Ruiz-Dern, L, Sadowski, G, Sagrista Selles, T, Sahlmann, J, Salgado, J, Salguero, E, Sanna, N, Santana-Ros, T, Sarasso, M, Savietto, H, Schultheis, M, Sciacca, E, Segol, M, Segovia, JC, Segransan, D, Shih, I-C, Siltala, L, Silva, AF, Smart, RL, Smith, KW, Solano, E, Solitro, F, Sordo, R, Soria Nieto, S, Souchay, J, Spagna, A, Spoto, F, Stampa, U, Steele, IA, Steidelmueller, H, Stephenson, CA, Stoev, H, Suess, FF, Surdej, J, Szabados, L, Szegedi-Elek, E, Tapiador, D, Taris, F, Tauran, G, Taylor, MB, Teixeira, R, Terrett, D, Teyssandier, P, Thuillot, W, Titarenko, A, Torra Clotet, F, Turon, C, Ulla, A, Utrilla, E, Uzzi, S, Vaillant, M, Valentini, G, Valette, V, van Elteren, A, Van Hemelryck, E, van Leeuwen, M, Vaschetto, M, Vecchiato, A, Veljanoski, J, Viala, Y, Vicente, D, Vogt, S, von Essen, C, Voss, H, Votruba, V, Voutsinas, S, Walmsley, G, Weiler, M, Wertz, O, Wevers, T, Wyrzykowski, L, Yoldas, A, Zerjal, M, Ziaeepour, H, Zorec, J, Zschocke, S, Zucker, S, Zurbach, C, and Zwitter, T
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QC ,QB - Abstract
Context. We present the second Gaia data release, Gaia DR2, consisting of astrometry, photometry, radial velocities, and information on astrophysical parameters and variability, for sources brighter than magnitude 21. In addition epoch astrometry and photometry are provided for a modest sample of minor planets in the solar system.\ud \ud Aims. A summary of the contents of Gaia DR2 is presented, accompanied by a discussion on the differences with respect to Gaia DR1 and an overview of the main limitations which are still present in the survey. Recommendations are made on the responsible use of Gaia DR2 results.\ud \ud Methods. The raw data collected with the Gaia instruments during the first 22 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into this second data release, which represents a major advance with respect to Gaia DR1 in terms of completeness, performance, and richness of the data products. Results. Gaia DR2 contains celestial positions and the apparent brightness in G for approximately 1.7 billion sources. For 1.3 billion of those sources, parallaxes and proper motions are in addition available. The sample of sources for which variability information is provided is expanded to 0.5 million stars. This data release contains four new elements: broad-band colour information in the form of the apparent brightness in the GBP (330–680 nm) and GRP (630–1050 nm) bands is available for 1.4 billion sources; median radial velocities for some 7 million sources are presented; for between 77 and 161 million sources estimates are provided of the stellar effective temperature, extinction, reddening, and radius and luminosity; and for a pre-selected list of 14 000 minor planets in the solar system epoch astrometry and photometry are presented. Finally, Gaia DR2 also represents a new materialisation of the celestial reference frame in the optical, the Gaia-CRF2, which is the first optical reference frame based solely on extragalactic sources. There are notable changes in the photometric system and the catalogue source list with respect to Gaia DR1, and we stress the need to consider the two data releases as independent. Conclusions. Gaia DR2 represents a major achievement for the Gaia mission, delivering on the long standing promise to provide parallaxes and proper motions for over 1 billion stars, and representing a first step in the availability of complementary radial velocity and source astrophysical information for a sample of stars in the Gaia survey which covers a very substantial fraction of the volume of our galaxy.
24. Gaia Early Data Release 3: Photometric content and validation
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Riello, M, De Angeli, F, Evans, DW, Montegriffo, P, Carrasco, JM, Busso, G, Palaversa, L, Burgess, PW, DIener, C, Davidson, M, Rowell, N, Fabricius, C, Jordi, C, Bellazzini, M, Pancino, E, Harrison, DL, Cacciari, C, Van Leeuwen, F, Hambly, NC, Hodgkin, ST, Osborne, PJ, Altavilla, G, Barstow, MA, Brown, AGA, Castellani, M, Cowell, S, De Luise, F, Gilmore, G, Giuffrida, G, Hidalgo, S, Holland, G, Marinoni, S, Pagani, C, Piersimoni, AM, Pulone, L, Ragaini, S, Rainer, M, Richards, PJ, Sanna, N, Walton, NA, Weiler, M, and Yoldas, A
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instrumentation: photometers ,techniques: photometric ,surveys ,13. Climate action ,7. Clean energy ,Galaxy: general ,catalogs - Abstract
Gaia Early Data Release 3 contains astrometry and photometry results for about 1.8 billion sources based on observations collected by the ESA Gaia satellite during the first 34 months of operations. This paper focuses on the photometric content, describing the input data, the algorithms, the processing, and the validation of the results. Particular attention is given to the quality of the data and to a number of features that users may need to take into account to make the best use of the EDR3 catalogue. The treatment of the BP and RP background has been updated to include a better estimation of the local background, and the detection of crowding effects has been used to exclude affected data from the calibrations. The photometric calibration models have also been updated to account for flux loss over the whole magnitude range. Significant improvements in the modelling and calibration of the point and line spread functions have also helped to reduce a number of instrumental effects that were still present in DR2. EDR3 contains 1.806 billion sources with G-band photometry and 1.540 billion sources with BP and RP photometry. The median uncertainty in the G-band photometry, as measured from the standard deviation of the internally calibrated mean photometry for a given source, is 0.2 mmag at magnitude G=10 to 14, 0.8 mmag at G=17, and 2.6 mmag at G=19. The significant magnitude term found in the Gaia DR2 photometry is no longer visible, and overall there are no trends larger than 1 mmag/mag. Using one passband over the whole colour and magnitude range leaves no systematics above the 1% level in magnitude in any of the bands, and a larger systematic is present for a very small sample of bright and blue sources. A detailed description of the residual systematic effects is provided. Overall the quality of the calibrated mean photometry in EDR3 is superior with respect to DR2 for all bands.
25. Prebiotic galactooligosaccharide feed modifies the chicken gut microbiota to efficiently clear Salmonella .
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Richards PJ, Almutrafy A, Liang L, Flaujac Lafontaine GM, King E, Fish NM, Connerton AJ, Connerton PL, and Connerton IF
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- Animals, Poultry Diseases microbiology, Poultry Diseases prevention & control, Poultry Diseases immunology, Cecum microbiology, Cecum metabolism, Chickens microbiology, Chickens immunology, Prebiotics administration & dosage, Gastrointestinal Microbiome drug effects, Oligosaccharides administration & dosage, Oligosaccharides pharmacology, Salmonella Infections, Animal prevention & control, Salmonella Infections, Animal microbiology, Salmonella Infections, Animal immunology, Animal Feed analysis, Salmonella enteritidis
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Chicken meat is contaminated with Salmonella from the gut of infected chickens during slaughter. Eradication of Salmonella from broiler chickens through hygiene measures and/or vaccination is not cost-effective; complementary approaches are required. A mature gut microbiota obstructs Salmonella infection in chickens, and deliberate fortification of colonization resistance through prebiotic feed formulations would benefit public health and poultry production. Prebiotic galactooligosaccharides hastens Salmonella clearance from the gut of infected chickens. To better understand the role of galactooligosaccharides in colonization resistance, broiler chickens were raised on a wheat-soybean meal-based feed, with or without galactooligosaccharides for the first 24 days of life. Chickens were orally challenged with Salmonella enterica serovar Enteritidis at 20 days and the effect of supplementary galactooligosaccharides characterized by profiling Salmonella colonization, gut microbiota, innate immune response, and cecal short-chain fatty acid concentrations. Exposure to dietary galactooligosaccharides shortened the time to clear S . Enteritidis from the ceca. Differential abundance analysis of the cecal microbiota associated Salmonella challenge with a bacterial taxon belonging to the Acidaminococcaceae family ( P < 0.005). Increased cecal concentrations of the short-chain fatty acids propionate and valerate were measured in Salmonella -challenged chickens sustained on either control or galactooligosaccharide-supplemented feed relative to mock-challenged controls; but far greater concentrations were detected in chickens fed a galactooligosaccharide-supplemented diet in early life. The abundance of the Acidaminococcaceae taxon exhibited a positive correlation with the cecal concentrations of propionate (ρ = 0.724, P = 0.008) and valerate (ρ = 0.71, P = 0.013). The absence of cecal pro-inflammatory transcriptional responses suggest that the rapid Salmonella clearance observed for the galactooligosaccharide-supplemented diet was not linked to innate immune function., Importance: Work presented here identifies bacterial taxa responsible for colonization resistance to Salmonella in broiler chickens. Deliberate cultivation of these taxa with prebiotic galactooligosaccharide has potential as a straight-forward, safe, and cost-effective intervention against Salmonella . We hypothesize that catabolism of galactooligosaccharide and its breakdown products by indigenous microorganisms colonizing the chicken gut produce excess levels of propionate. In the absence of gross inflammation, propionate is inimical to Salmonella and hastens intestinal clearance., Competing Interests: N.M.F. was a consultant to Dairy Crest Ltd.
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- 2024
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26. NONSURGICAL RESOLUTION OF FULL-THICKNESS MACULAR HOLES WITHOUT VITREOMACULAR TRACTION.
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Richards PJ, Kulkarni AD, Nork TM, Leys M, Hinkle D, Conlin KA, Chang S, and Chang JS
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- Humans, Retrospective Studies, Traction, Vitrectomy, Vision Disorders, Vitreous Body surgery, Tomography, Optical Coherence, Retinal Perforations therapy, Retinal Perforations surgery
- Abstract
Background/purpose: The purpose of this study was to report a case series of full-thickness macular holes without vitreomacular traction that resolved without surgery., Methods: This study is a retrospective case series of 11 patients who demonstrated closure of full-thickness macular holes without surgical intervention., Results: All full-thickness macular holes closed, with all patients having improvement in visual acuity. All but one of the cases had visual acuity better than 20/40 at last recorded visit. Most cases presented with associated epiretinal membrane (73%), cystoid changes (64%), defects <150 μ m (80%), and resolved within 2 months (91%). Topical anti-inflammatory drops were used in 7 of 11 cases, and dorzolamide was used in one case., Conclusion: Full-thickness macular holes can develop in eyes without the presence of vitreomacular traction. Topical therapy without vitrectomy may be particularly helpful in closure of full-thickness macular holes with associated cystoid macular edema. Holes with a lamellar hole component may spontaneously resolve as part of a retinal remodeling process.
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- 2023
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27. Peripheral Exudative Hemorrhagic Chorioretinopathy (PEHCR): Diagnostic and Therapeutic Challenges.
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Elwood KF, Richards PJ, Schildroth KR, and Mititelu M
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- Female, Humans, Aged, Diagnosis, Differential, Exudates and Transudates, Fluorescein Angiography, Hemorrhage diagnosis, Hemorrhage etiology, Retina
- Abstract
Background and Objectives: Peripheral exudative hemorrhagic chorioretinopathy (PEHCR) is a peripheral retinal vascular abnormality that is likely underreported. We review the differential diagnoses, etiology, and treatment options for PEHCR. Methods: We present a case of an asymptomatic 72-year-old female referred following left eye fundus photography finding of the peripheral lesion. Results: Fundus photography demonstrated a large temporal pigment epithelial detachment (PED) with adjacent fibrovascular membrane. Optical coherence tomography (OCT) confirmed the PED with trace subretinal fluid. Fluorescein angiography (FA) demonstrated early and late hypofluorescence of the PED with late leakage of the adjacent temporal fibrovascular membrane. Observation was elected, visual acuity remained unaffected, and the PED spontaneously resolved. Conclusions: Due to the peripheral location, patients often present as asymptomatic; however, vision loss can occur due to vitreous hemorrhage or extension of subretinal fluid, hemorrhage, or exudate to the macula. Commonly, these lesions are referred with concern for choroidal melanoma due to their large, dark, elevated presentation in the peripheral retina. Multimodal testing using B-scan, FA, and OCT is important in establishing the proper diagnosis. PEHCR lesions can often be observed without treatment, though intravitreal injection of anti-VEGF is increasingly used to prevent secondary causes of vision loss.
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- 2023
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28. Degenerative joint disease induced by repeated intra-articular injections of monosodium urate crystals in rats as investigated by translational imaging.
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Accart N, Dawson J, Obrecht M, Lambert C, Flueckiger M, Kreider J, Hatakeyama S, Richards PJ, and Beckmann N
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- Animals, Arthritis, Gouty chemically induced, Arthritis, Gouty metabolism, Arthritis, Gouty pathology, Biopsy, Crystallization, Cytokines metabolism, Disease Models, Animal, Disease Progression, Female, Inflammation Mediators metabolism, Injections, Intra-Articular, Joints metabolism, Joints pathology, Lipopolysaccharides, Predictive Value of Tests, Rats, Rats, Inbred Lew, Synovial Fluid metabolism, Time Factors, Translational Research, Biomedical, X-Ray Microtomography, Arthritis, Gouty diagnostic imaging, Joints diagnostic imaging, Magnetic Resonance Imaging, Uric Acid
- Abstract
The objective of this work was to assess the consequences of repeated intra-articular injection of monosodium urate (MSU) crystals with inflammasome priming by lipopolysaccharide (LPS) in order to simulate recurrent bouts of gout in rats. Translational imaging was applied to simultaneously detect and quantify injury in different areas of the knee joint. MSU/LPS induced joint swelling, synovial membrane thickening, fibrosis of the infrapatellar fat pad, tidemark breaching, and cartilage invasion by inflammatory cells. A higher sensitivity to mechanical stimulus was detected in paws of limbs receiving MSU/LPS compared to saline-injected limbs. In MSU/LPS-challenged joints, magnetic resonance imaging (MRI) revealed increased synovial fluid volume in the posterior region of the joint, alterations in the infrapatellar fat pad reflecting a progressive decrease of fat volume and fibrosis formation, and a significant increase in the relaxation time T
2 in femoral cartilage, consistent with a reduction of proteoglycan content. MRI also showed cyst formation in the tibia, femur remodeling, and T2 reductions in extensor muscles consistent with fibrosis development. Repeated intra-articular MSU/LPS injections in the rat knee joint induced pathology in multiple tissues and may be a useful means to investigate the relationship between urate crystal deposition and the development of degenerative joint disease., (© 2022. The Author(s).)- Published
- 2022
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29. Uveitis reactivation following recombinant zoster vaccination.
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Richards PJ, Wingelaar MJ, Armbrust KR, and Kopplin LJ
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Purpose: Describe three cases of uveitis reactivation following immunization with recombinant zoster vaccine (RZV)., Observations: One patient developed reactivation of previously controlled multifocal choroiditis within one week of receiving RZV, requiring treatment with systemic corticosteroids. Two patients with previously controlled anterior uveitis developed new anterior segment inflammation after RZV; both were treated with topical corticosteroids and systemic antiviral therapy., Conclusion and Importance: Uveitis recurrence is an infrequent but serious potential ocular side effect of recombinant zoster vaccination., Competing Interests: No conflicting relationships exists for any author., (© 2021 The Authors. Published by Elsevier Inc.)
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- 2021
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30. Magnetic fields modulate metabolism and gut microbiome in correlation with Pgc-1α expression: Follow-up to an in vitro magnetic mitohormetic study.
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Tai YK, Ng C, Purnamawati K, Yap JLY, Yin JN, Wong C, Patel BK, Soong PL, Pelczar P, Fröhlich J, Beyer C, Fong CHH, Ramanan S, Casarosa M, Cerrato CP, Foo ZL, Pannir Selvan RM, Grishina E, Degirmenci U, Toh SJ, Richards PJ, Mirsaidi A, Wuertz-Kozak K, Chong SY, Ferguson SJ, Aguzzi A, Monici M, Sun L, Drum CL, Wang JW, and Franco-Obregón A
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- Adaptation, Physiological physiology, Animals, Bacteroidetes growth & development, Body Composition physiology, Fatty Acids metabolism, Female, Firmicutes growth & development, Follow-Up Studies, Gene Expression physiology, Insulin metabolism, Magnetic Fields, Mice, Mice, Inbred C57BL, Mitochondria metabolism, Muscle Development physiology, Muscle, Skeletal metabolism, Physical Conditioning, Animal physiology, Transcription, Genetic physiology, Transcriptional Activation physiology, Gastrointestinal Microbiome physiology, Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha metabolism
- Abstract
Exercise modulates metabolism and the gut microbiome. Brief exposure to low mT-range pulsing electromagnetic fields (PEMFs) was previously shown to accentuate in vitro myogenesis and mitochondriogenesis by activating a calcium-mitochondrial axis upstream of PGC-1α transcriptional upregulation, recapitulating a genetic response implicated in exercise-induced metabolic adaptations. We compared the effects of analogous PEMF exposure (1.5 mT, 10 min/week), with and without exercise, on systemic metabolism and gut microbiome in four groups of mice: (a) no intervention; (b) PEMF treatment; (c) exercise; (d) exercise and PEMF treatment. The combination of PEMFs and exercise for 6 weeks enhanced running performance and upregulated muscular and adipose Pgc-1α transcript levels, whereas exercise alone was incapable of elevating Pgc-1α levels. The gut microbiome Firmicutes/Bacteroidetes ratio decreased with exercise and PEMF exposure, alone or in combination, which has been associated in published studies with an increase in lean body mass. After 2 months, brief PEMF treatment alone increased Pgc-1α and mitohormetic gene expression and after >4 months PEMF treatment alone enhanced oxidative muscle expression, fatty acid oxidation, and reduced insulin levels. Hence, short-term PEMF treatment was sufficient to instigate PGC-1α-associated transcriptional cascades governing systemic mitohormetic adaptations, whereas longer-term PEMF treatment was capable of inducing related metabolic adaptations independently of exercise., (© 2020 The Authors. The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.)
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- 2020
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31. Galacto-Oligosaccharides Modulate the Juvenile Gut Microbiome and Innate Immunity To Improve Broiler Chicken Performance.
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Richards PJ, Flaujac Lafontaine GM, Connerton PL, Liang L, Asiani K, Fish NM, and Connerton IF
- Abstract
Improvements in growth performance and health are key goals in broiler chicken production. Inclusion of prebiotic galacto-oligosaccharides (GOS) in broiler feed enhanced the growth rate and feed conversion of chickens relative to those obtained with a calorie-matched control diet. Comparison of the cecal microbiota identified key differences in abundances of Lactobacillus spp. Increased levels of Lactobacillus johnsonii in GOS-fed juvenile birds at the expense of Lactobacillus crispatus were linked to improved performance (growth rate and market weight). Investigation of the innate immune responses highlighted increases of ileal and cecal interleukin-17A (IL-17A) gene expression counterposed to a decrease in IL-10. Quantification of the autochthonous Lactobacillus spp. revealed a correlation between bird performance and L. johnsonii abundance. Shifts in the cecal populations of key Lactobacillus spp. of juvenile birds primed intestinal innate immunity without harmful pathogen challenge. IMPORTANCE Improvements in the growth rate of broiler chickens can be achieved through dietary manipulation of the naturally occurring bacterial populations while mitigating the withdrawal of antibiotic growth promoters. Prebiotic galacto-oligosaccharides (GOS) are manufactured as a by-product of dairy cheese production and can be incorporated into the diets of juvenile chickens to improve their health and performance. This study investigated the key mechanisms behind this progression and pinpointed L. johnsonii as a key species that facilitates the enhancements in growth rate and gut health. The study identified the relationships between the GOS diet, L. johnsonii intestinal populations, and cytokine immune effectors to improve growth., (Copyright © 2020 Richards et al.)
- Published
- 2020
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32. Prebiotic Driven Increases in IL-17A Do Not Prevent Campylobacter jejuni Colonization of Chickens.
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Flaujac Lafontaine GM, Richards PJ, Connerton PL, O'Kane PM, Ghaffar NM, Cummings NJ, Fish NM, and Connerton IF
- Abstract
Worldwide Campylobacter jejuni is a leading cause of foodborne disease. Contamination of chicken meat with digesta from C. jejuni -positive birds during slaughter and processing is a key route of transmission to humans through the food chain. Colonization of chickens with C. jejuni elicits host innate immune responses that may be modulated by dietary additives to provide a reduction in the number of campylobacters colonizing the gastrointestinal tract and thereby reduce the likelihood of human exposure to an infectious dose. Here we report the effects of prebiotic galacto-oligosaccharide (GOS) on broiler chickens colonized with C. jejuni when challenged at either an early stage in development at 6 days of age or 20 days old when campylobacters are frequently detected in commercial flocks. GOS-fed birds had increased growth performance, but the levels of C. jejuni colonizing the cecal pouches were unchanged irrespective of the age of challenge. Dietary GOS modulated the immune response to C. jejuni by increasing cytokine IL-17A expression at colonization. Correspondingly, reduced diversity of the cecal microbiota was associated with Campylobacter colonization in GOS-fed birds. In birds challenged at 6 days-old the reduction in microbial diversity was accompanied by an increase in the relative abundance of Escherichia spp. Whilst immuno-modulation of the Th17 pro-inflammatory response did not prevent C. jejuni colonization of the intestinal tract of broiler chickens, the study highlights the potential for combinations of prebiotics, and specific competitors (synbiotics) to engage with the host innate immunity to reduce pathogen burdens., (Copyright © 2020 Flaujac Lafontaine, Richards, Connerton, O’Kane, Ghaffar, Cummings, Fish and Connerton.)
- Published
- 2020
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33. Phage Biocontrol of Campylobacter jejuni in Chickens Does Not Produce Collateral Effects on the Gut Microbiota.
- Author
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Richards PJ, Connerton PL, and Connerton IF
- Abstract
Bacteriophage biocontrol to reduce Campylobacter jejuni levels in chickens can reduce human exposure and disease acquired through the consumption of contaminated poultry products. Investigating changes in the chicken microbiota during phage treatment has not previously been undertaken but is crucial to understanding the system-wide effects of such treatments to establish a sustainable application. A phage cocktail containing two virulent Campylobacter phages was used to treat broiler chickens colonized with C. jejuni HPC5. Campylobacter counts from cecal contents were significantly reduced throughout the experimental period but were most effective 2 days post-treatment showing a reduction of 2.4 log
10 CFU g-1 relative to mock-treated Campylobacter colonized controls. The administered phages replicated in vivo to establish stable populations. Bacteriophage predation of C. jejuni was not found to affect the microbiota structure but selectively reduced the relative abundance of C. jejuni without affecting other bacteria.- Published
- 2019
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34. The effect of the timing of exposure to Campylobacter jejuni on the gut microbiome and inflammatory responses of broiler chickens.
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Connerton PL, Richards PJ, Lafontaine GM, O'Kane PM, Ghaffar N, Cummings NJ, Smith DL, Fish NM, and Connerton IF
- Subjects
- Animals, Campylobacter Infections microbiology, Campylobacter jejuni immunology, Chemokines metabolism, Chickens, Food Safety, Inflammation immunology, Male, Poultry Diseases microbiology, Th17 Cells immunology, Campylobacter Infections immunology, Campylobacter jejuni isolation & purification, Cecum microbiology, Gastrointestinal Microbiome immunology, Intestinal Mucosa immunology, Intestinal Mucosa microbiology, Poultry Diseases immunology
- Abstract
Background: Campylobacters are an unwelcome member of the poultry gut microbiota in terms of food safety. The objective of this study was to compare the microbiota, inflammatory responses, and zootechnical parameters of broiler chickens not exposed to Campylobacter jejuni with those exposed either early at 6 days old or at the age commercial broiler chicken flocks are frequently observed to become colonized at 20 days old., Results: Birds infected with Campylobacter at 20 days became cecal colonized within 2 days of exposure, whereas birds infected at 6 days of age did not show complete colonization of the sample cohort until 9 days post-infection. All birds sampled thereafter were colonized until the end of the study at 35 days (mean 6.1 log
10 CFU per g of cecal contents). The cecal microbiota of birds infected with Campylobacter were significantly different to age-matched non-infected controls at 2 days post-infection, but generally, the composition of the cecal microbiota were more affected by bird age as the time post infection increased. The effects of Campylobacter colonization on the cecal microbiota were associated with reductions in the relative abundance of OTUs within the taxonomic family Lactobacillaceae and the Clostridium cluster XIVa. Specific members of the Lachnospiraceae and Ruminococcaceae families exhibit transient shifts in microbial community populations dependent upon the age at which the birds become colonized by C. jejuni. Analysis of ileal and cecal chemokine/cytokine gene expression revealed increases in IL-6, IL-17A, and Il-17F consistent with a Th17 response, but the persistence of the response was dependent on the stage/time of C. jejuni colonization that coincide with significant reductions in the abundance of Clostridium cluster XIVa., Conclusions: This study combines microbiome data, cytokine/chemokine gene expression with intestinal villus, and crypt measurements to compare chickens colonized early or late in the rearing cycle to provide insights into the process and outcomes of Campylobacter colonization. Early colonization results in a transient growth rate reduction and pro-inflammatory response but persistent modification of the cecal microbiota. Late colonization produces pro-inflammatory responses with changes in the cecal microbiota that will endure in market-ready chickens.- Published
- 2018
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35. Role of HTRA1 in bone formation and regeneration: In vitro and in vivo evaluation.
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Filliat G, Mirsaidi A, Tiaden AN, Kuhn GA, Weber FE, Oka C, and Richards PJ
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- Adipogenesis physiology, Animals, Bone Morphogenetic Protein 2 metabolism, Calcification, Physiologic physiology, Cell Differentiation physiology, Cell Line, Gene Expression physiology, Humans, Mesenchymal Stem Cells metabolism, Mesenchymal Stem Cells physiology, Mice, Osteoblasts metabolism, Chondrogenesis physiology, Osteogenesis physiology, Regeneration physiology, Serine Endopeptidases metabolism
- Abstract
The role of mammalian high temperature requirement protease A1 (HTRA1) in somatic stem cell differentiation and mineralized matrix formation remains controversial, having been demonstrated to impart either anti- or pro-osteogenic effects, depending on the in vitro cell model used. The aim of this study was therefore to further evaluate the role of HTRA1 in regulating the differentiation potential and lineage commitment of murine mesenchymal stem cells in vitro, and to assess its influence on bone structure and regeneration in vivo. Our results demonstrated that short hairpin RNA-mediated ablation of Htra1 in the murine mesenchymal cell line C3H10T1/2 increased the expression of several osteogenic gene markers, and significantly enhanced matrix mineralization in response to BMP-2 stimulation. These effects were concomitant with decreases in the expression of chondrogenic gene markers, and increases in adipogenic gene expression and lipid accrual. Despite the profound effects of loss-of-function of HTRA1 on this in vitro osteochondral model, these were not reproduced in vivo, where bone microarchitecture and regeneration in 16-week-old Htra1-knockout mice remained unaltered as compared to wild-type controls. By comparison, analysis of femurs from 52-week-old mice revealed that bone structure was better preserved in Htra1-knockout mice than age-matched wild-type controls. These findings therefore provide additional insights into the role played by HTRA1 in regulating mesenchymal stem cell differentiation, and offer opportunities for improving our understanding of how this multifunctional protease may act to influence bone quality.
- Published
- 2017
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36. Tailored Ahp-cyclodepsipeptides as Potent Non-covalent Serine Protease Inhibitors.
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Köcher S, Rey J, Bongard J, Tiaden AN, Meltzer M, Richards PJ, Ehrmann M, and Kaiser M
- Subjects
- Depsipeptides chemical synthesis, Depsipeptides chemistry, Dose-Response Relationship, Drug, Humans, Models, Molecular, Molecular Conformation, Serine Proteinase Inhibitors chemical synthesis, Serine Proteinase Inhibitors chemistry, Structure-Activity Relationship, Depsipeptides pharmacology, Serine Proteases metabolism, Serine Proteinase Inhibitors pharmacology
- Abstract
The S1 serine protease family is one of the largest and most biologically important protease families. Despite their biomedical significance, generic approaches to generate potent, class-specific, bioactive non-covalent inhibitors for these enzymes are still limited. In this work, we demonstrate that Ahp-cyclodepsipeptides represent a suitable scaffold for generating target-tailored inhibitors of serine proteases. For efficient synthetic access, we developed a practical mixed solid- and solution-phase synthesis that we validated through performing the first chemical synthesis of the two natural products Tasipeptin A and B. The suitability of the Ahp-cyclodepsipeptide scaffold for tailored inhibitor synthesis is showcased by the generation of the most potent human HTRA protease inhibitors to date. We anticipate that our approach may also be applied to other serine proteases, thus opening new avenues for a systematic discovery of serine protease inhibitors., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2017
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37. Prostaglandin E 2 inhibits matrix mineralization by human bone marrow stromal cell-derived osteoblasts via Epac-dependent cAMP signaling.
- Author
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Mirsaidi A, Tiaden AN, and Richards PJ
- Subjects
- Adipogenesis drug effects, Cells, Cultured, Cyclic AMP metabolism, Dinoprostone pharmacology, Guanine Nucleotide Exchange Factors metabolism, Humans, Models, Molecular, Osteogenesis drug effects, Receptors, Prostaglandin E, EP2 Subtype metabolism, Receptors, Prostaglandin E, EP4 Subtype metabolism, Signal Transduction, Calcification, Physiologic drug effects, Dinoprostone metabolism, Extracellular Matrix metabolism, Mesenchymal Stem Cells metabolism, Osteoblasts metabolism
- Abstract
The osteoinductive properties of prostaglandin E
2 (PGE2 ) and its signaling pathways have led to suggestions that it may serve as a potential therapeutic strategy for bone loss. However, the prominence of PGE2 as an inducer of bone formation is attributed primarily to findings from studies using rodent models. In the current study, we investigated the effects of PGE2 on human bone marrow stromal cell (hBMSC) lineage commitment and determined its mode of action. We demonstrated that PGE2 treatment of hBMSCs significantly altered the expression profile of several genes associated with osteoblast differentiation (RUNX2 and ALP) and maturation (BGLAP and MGP). This was attributed to the activation of specific PGE2 receptors, and was associated with increases in cAMP production and sustained AKT phosphorylation. Pharmacological inhibition of exchange protein directly activated by cAMP (Epac), but not protein kinase A (PKA), recovered the mineralization functions of hBMSC-derived osteoblasts treated with PGE2 and restored AKT phosphorylation, along with the expression levels of RUNX2, ALP, BGLAP and MGP. Our findings therefore provide insights into how PGE2 influences hBMSC-mediated matrix mineralization, and should be taken into account when evaluating the role of PGE2 in human bone metabolism.- Published
- 2017
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38. Identification of Novel Equine (Equus caballus) Tendon Markers Using RNA Sequencing.
- Author
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Kuemmerle JM, Theiss F, Okoniewski MJ, Weber FA, Hemmi S, Mirsaidi A, Richards PJ, and Cinelli P
- Abstract
Although several tendon-selective genes exist, they are also expressed in other musculoskeletal tissues. As cell and tissue engineering is reliant on specific molecular markers to discriminate between cell types, tendon-specific genes need to be identified. In order to accomplish this, we have used RNA sequencing (RNA-seq) to compare gene expression between tendon, bone, cartilage and ligament from horses. We identified several tendon-selective gene markers, and established eyes absent homolog 2 ( EYA2 ) and a G-protein regulated inducer of neurite outgrowth 3 ( GPRIN3 ) as specific tendon markers using RT-qPCR. Equine tendon cells cultured as three-dimensional spheroids expressed significantly greater levels of EYA2 than GPRIN3 , and stained positively for EYA2 using immunohistochemistry. EYA2 was also found in fibroblast-like cells within the tendon tissue matrix and in cells localized to the vascular endothelium. In summary, we have identified EYA2 and GPRIN3 as specific molecular markers of equine tendon as compared to bone, cartilage and ligament, and provide evidence for the use of EYA2 as an additional marker for tendon cells in vitro., Competing Interests: The authors declare no conflict of interest.
- Published
- 2016
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39. Diagnostic performance of volume and limited oblique MRI of the anterior cruciate ligament compared to knee arthroscopy.
- Author
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Richards PJ, McCall I, Kraus A, Jones M, Maffulli G, Bridgman S, and Maffulli N
- Abstract
Background: Many strategies have been used to improve the visualisation of the ACL including sagittal, coronal oblique sequences, and 3D volume imaging. Nevertheless, the ACL may not always be visualised., Methods: Two hundred and thirty-one consecutive patients (77 females; 154 males; average age 43.5, range 18 to 82 years; 205 with chronic, 20 acute, and 6 acute on chronic symptoms) underwent knee arthroscopy for mechanical symptoms within a week of MRI. After routine orthogonal sequences, if general MRI radiographers, with over four years experience, were not able to identify the presence of the ACL, then two 3D volume sequences and 2D limited sagittal oblique T1 sequences were performed. Patients requiring extra sequences, missed by the radiography technicians, were recalled. The MRI sequences were evaluated in a blinded fashion by three radiologists, and compared to the knee arthroscopy findings, with the normal ACL acting as internal controls. The radiography technicians performed additional ACL sequences in 63 patients (27%); of these, 10 patients had a partial and 12 patients had a complete ACL tear. Only 2 patients (0.6%) were recalled (one with a normal, and one with a full thickness ACL tear)., Results: The filmed ACL evaluation for complete tears and a normal ACL had a sensitivity of 100%, specificity of 97.1% and accuracy of 97.3%, slightly higher than evaluating on the monitor. Volume sequences had specificities and accuracies over 95%, with good intraobserver reliability (Kappa 0.859, 95% CI 0.705-1.0). Experienced radiographers identified most cases requiring supplementary MRI ACL sequences. An additional volume sequence was beneficial when filmed. Use of the monitor can offer some benefits. Limited oblique T1 sequence of the intercondylar notch was unreliable.
- Published
- 2016
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40. Novel Function of Serine Protease HTRA1 in Inhibiting Adipogenic Differentiation of Human Mesenchymal Stem Cells via MAP Kinase-Mediated MMP Upregulation.
- Author
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Tiaden AN, Bahrenberg G, Mirsaidi A, Glanz S, Blüher M, and Richards PJ
- Subjects
- Enzyme Activation, Extracellular Matrix metabolism, Heparan Sulfate Proteoglycans metabolism, Humans, Intra-Abdominal Fat pathology, Lipid Droplets metabolism, Obesity pathology, Adipogenesis, High-Temperature Requirement A Serine Peptidase 1 metabolism, JNK Mitogen-Activated Protein Kinases metabolism, Matrix Metalloproteinases metabolism, Mesenchymal Stem Cells cytology, Mesenchymal Stem Cells enzymology, Up-Regulation
- Abstract
Adipogenesis is the process by which mesenchymal stem cells (MSCs) develop into lipid-laden adipocytes. Being the dominant cell type within adipose tissue, adipocytes play a central role in regulating circulating fatty acid levels, which is considered to be of critical importance in maintaining insulin sensitivity. High temperature requirement protease A1 (HTRA1) is a newly recognized regulator of MSC differentiation, although its role as a mediator of adipogenesis has not yet been defined. The aim of this work was therefore to evaluate HTRA1's influence on human MSC (hMSC) adipogenesis and to establish a potential mode of action. We report that the addition of exogenous HTRA1 to hMSCs undergoing adipogenesis suppressed their ability to develop into lipid laden adipocytes. These effects were demonstrated as being reliant on both its protease and PDZ domain, and were mediated through the actions of c-Jun N-terminal kinase and matrix metalloproteinases (MMPs). The relevance of such findings with regards to HTRA1's potential influence on adipocyte function in vivo is made evident by the fact that HTRA1 and MMP-13 were readily identifiable within crown-like structures present in visceral adipose tissue samples from insulin resistant obese human subjects. These data therefore implicate HTRA1 as a negative regulator of MSC adipogenesis and are suggestive of its potential involvement in adipose tissue remodeling under pathological conditions. Stem Cells 2016;34:1601-1614., (© 2016 AlphaMed Press.)
- Published
- 2016
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41. A soft patellar tendon on ultrasound elastography is associated with pain and functional deficit in volleyball players.
- Author
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Ooi CC, Richards PJ, Maffulli N, Ede D, Schneider ME, Connell D, Morrissey D, and Malliaras P
- Subjects
- Adolescent, Adult, Cohort Studies, Female, Humans, Male, Patellar Ligament physiopathology, Tendinopathy physiopathology, Young Adult, Elasticity Imaging Techniques, Patellar Ligament diagnostic imaging, Tendinopathy diagnostic imaging, Volleyball physiology
- Abstract
Objectives: To investigate the diagnostic performance of grey scale Ultrasound (US), power Doppler (PD) and US elastography for diagnosing painful patellar tendinopathy, and to establish their relationship with Victorian Institute of Sport Assessment-Patella (VISA-P) scores in a group of volleyball players with and without symptoms of patellar tendinopathy., Design: Cross-sectional study., Methods: Thirty-five volleyball players (70 patellar tendons) were recruited during a national university volleyball competition. Players were imaged with conventional US followed by elastography. The clinical findings of painful patellar tendons were used as the reference standard for diagnosing patellar tendinopathy. In addition, all participants completed the VISA-P questionnaires., Results: Of the 70 patellar tendons, 40 (57.1%) were clinically painful. The diagnostic accuracy of grey scale US, PD and elastography were 60%, 50%, 62.9%, respectively, with sensitivity/specificity of 72.5%/43.3%, 12.5%/100%, and 70%/53.3%, respectively. Combined US elastography and grey scale imaging achieved 82.5% sensitivity, 33.3% specificity and 61.4% accuracy while routine combination technique of PD and grey scale imaging revealed 72.5% sensitivity, 43.3% specificity and 60.0% accuracy. Tendons in players categorized as soft on elastography had statistically significantly greater AP thickness (p<0.001) and lower VISA-P scores (p=0.004) than those categorized as hard. There was no significant association between grey scale US abnormalities (hypoechogenicities and/or fusiform swelling) and VISA-P scores (p=0.098)., Conclusions: Soft tendon properties depicted by US elastography may be more related to patellar tendon symptoms compared to grey scale US abnormalities. The supplementation of US elastography to conventional US may enhance the sensitivity for diagnosing patellar tendinopathy in routine clinical practice., (Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2016
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42. Loss-of-Function of HtrA1 Abrogates All-Trans Retinoic Acid-Induced Osteogenic Differentiation of Mouse Adipose-Derived Stromal Cells Through Deficiencies in p70S6K Activation.
- Author
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Glanz S, Mirsaidi A, López-Fagundo C, Filliat G, Tiaden AN, and Richards PJ
- Subjects
- Animals, Blotting, Western, Enzyme Activation drug effects, Gene Knockdown Techniques, High-Temperature Requirement A Serine Peptidase 1, Mice, Models, Biological, Mutation genetics, Serine Endopeptidases metabolism, Sirolimus pharmacology, Stromal Cells cytology, Stromal Cells drug effects, Stromal Cells enzymology, Adipose Tissue cytology, Cell Differentiation drug effects, Osteogenesis drug effects, Ribosomal Protein S6 Kinases, 70-kDa metabolism, Serine Endopeptidases deficiency, Tretinoin pharmacology
- Abstract
All-trans retinoic acid (ATRA) is a potent inducer of osteogenic differentiation in mouse adipose-derived stromal cells (mASCs), although the underlying mechanisms responsible for its mode of action have yet to be completely elucidated. High temperature requirement protease A1 (HtrA1) is a newly recognized modulator of human multipotent stromal cell (MSC) osteogenesis and as such, may play a role in regulating ATRA-dependent osteogenic differentiation of mASCs. In this study, we assessed the influence of small interfering RNA (siRNA)-induced repression of HtrA1 production on mASC osteogenesis and examined its effects on ATRA-mediated mammalian target of rapamycin (mTOR) signaling. Inhibition of HtrA1 production in osteogenic mASCs resulted in a significant reduction of alkaline phosphatase activity and mineralized matrix formation. Western blot analyses revealed the rapid activation of Akt (Ser473) and p70S6K (Thr389) in ATRA-treated mASCs, and that levels of phosphorylated p70S6K were noticeably reduced in HtrA1-deficient mASCs. Further studies using mTOR inhibitor rapamycin and siRNA specific for the p70S6K gene Rps6kb1 confirmed ATRA-mediated mASC osteogenesis as being dependent on p70S6K activation. Finally, transfection of cells with a constitutively active rapamycin-resistant p70S6K mutant could restore the mineralizing capacity of HtrA1-deficient mASCs. These findings therefore lend further support for HtrA1 as a positive mediator of MSC osteogenesis and provide new insights into the molecular mode of action of ATRA in regulating mASC lineage commitment.
- Published
- 2016
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43. ARTD1 regulates osteoclastogenesis and bone homeostasis by dampening NF-κB-dependent transcription of IL-1β.
- Author
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Robaszkiewicz A, Qu C, Wisnik E, Ploszaj T, Mirsaidi A, Kunze FA, Richards PJ, Cinelli P, Mbalaviele G, and Hottiger MO
- Subjects
- Animals, Autocrine Communication, Binding Sites, Cell Differentiation drug effects, Cell Differentiation genetics, Cell Line, DNA Topoisomerases, Type II metabolism, Enzyme Activation, Gene Expression Regulation, Gene Silencing, Inflammasomes metabolism, Interleukin-1beta metabolism, Mice, Mice, Knockout, NFATC Transcription Factors genetics, NFATC Transcription Factors metabolism, Osteoclasts cytology, Osteoclasts metabolism, Phenotype, Poly (ADP-Ribose) Polymerase-1 genetics, Promoter Regions, Genetic, Protein Binding, RANK Ligand metabolism, RANK Ligand pharmacology, Signal Transduction, Bone Resorption, Bone and Bones metabolism, Homeostasis, Interleukin-1beta genetics, NF-kappa B metabolism, Poly (ADP-Ribose) Polymerase-1 metabolism, Transcription, Genetic
- Abstract
While ADP-ribosyltransferase diphtheria toxin-like 1 (ARTD1, formerly PARP1) and its enzymatic activity have been shown to be important for reprogramming and differentiation of cells, such as during adipogenesis, their role and mechanism in regulating osteoclastogenesis and bone homeostasis are largely unknown. Here, in cell culture-based RANKL-induced osteoclastogenesis models, we show that silencing of ARTD1 or inhibition of its enzymatic activity enhances osteoclast differentiation and function. As a consequence of ARTD1 silencing or inhibition, the recruitment of p65/RelA to the IL-1β promoter, which is associated with transcriptionally active histone marks, IL-1β expression and inflammasome-dependent secretion of IL-1β are enhanced. This subsequently promotes sustained induction of the transcription factor Nfatc1/A and osteoclastogenesis in an autocrine manner via the IL-1 receptor. In vivo, Artd1-deficient mice display significantly decreased bone mass as a consequence of increased osteoclast differentiation. Accordingly, the expression of osteoclast markers is enhanced in mutant compared to wild-type mice. Together, these results indicate that ARTD1 controls osteoclast development and bone remodelling via its enzymatic activity by modulating the epigenetic marks surrounding the IL-1β promoter and expression of IL-1β and subsequently also Nfatc1/A.
- Published
- 2016
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44. Use of biomimetic microtissue spheroids and specific growth factor supplementation to improve tenocyte differentiation and adaptation to a collagen-based scaffold in vitro.
- Author
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Theiss F, Mirsaidi A, Mhanna R, Kümmerle J, Glanz S, Bahrenberg G, Tiaden AN, and Richards PJ
- Subjects
- Animals, Ascorbic Acid analogs & derivatives, Ascorbic Acid metabolism, Biomimetics, Cell Differentiation, Cells, Cultured, Horses, Regeneration, Spheroids, Cellular, Tendons physiology, Transforming Growth Factor beta1 metabolism, Collagen chemistry, Culture Media metabolism, Intercellular Signaling Peptides and Proteins metabolism, Tendons cytology, Tissue Engineering methods, Tissue Scaffolds chemistry
- Abstract
Tenocytes represent a valuable source of cells for the purposes of tendon tissue engineering and regenerative medicine and as such, should possess a high degree of tenogenic differentiation prior to their use in vivo in order to achieve maximal efficacy. In the current report, we identify an efficient means by which to maintain differentiated tenocytes in vitro by employing the hanging drop technique in combination with defined growth media supplements. Equine tenocytes retained a more differentiated state when cultured as scaffold-free microtissue spheroids in low serum-containing medium supplemented with L-ascorbic acid 2-phosphate, insulin and transforming growth factor (TGF)-β1. This was made evident by significant increases in the expression levels of pro-tenogenic markers collagen type I (COL1A2), collagen type III (COL3A1), scleraxis (SCX) and tenomodulin (TNMD), as well as by enhanced levels of collagen type I and tenomodulin protein. Furthermore, tenocytes cultured under these conditions demonstrated a typical spindle-like morphology and when embedded in collagen gels, became highly aligned with respect to the orientation of the collagen structure following their migration out from the microtissue spheroids. Our findings therefore provide evidence to support the use of a biomimetic microtissue approach to culturing tenocytes and that in combination with the defined growth media described, can improve their differentiation status and functional repopulation of collagen matrix., (Copyright © 2015 Elsevier Ltd. All rights reserved.)
- Published
- 2015
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45. Effect of a single dose of Saccharomyces cerevisiae var. boulardii on the occurrence of porcine neonatal diarrhoea.
- Author
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Hancox LR, Le Bon M, Richards PJ, Guillou D, Dodd CE, and Mellits KH
- Subjects
- Animals, Animals, Newborn, Body Weight, Diarrhea microbiology, Diarrhea therapy, Feces, Random Allocation, Swine, Swine Diseases microbiology, Weaning, Weight Gain, Diarrhea veterinary, Dietary Supplements, Probiotics administration & dosage, Saccharomyces cerevisiae physiology, Swine Diseases therapy
- Abstract
Piglet neonatal diarrhoea is an important issue in modern pig production and is linked to increased mortality and poor growth rates, affecting long-term pig health, increasing use of medication and cost of production. Saccharomyces cerevisiae var. boulardii (SB) is a probiotic yeast with documented clinical efficacy in the prevention and treatment of diarrhoeal diseases in humans. The objectives of the current study were to evaluate the effect of SB on occurrence and severity of neonatal diarrhoea in piglets, mortality and growth rate. Forty-six litters (606 piglets) were randomly allocated to a control or SB treatment (n=23 per treatment). Within 24 h of farrowing, piglets assigned to the SB treatment received a single oral dose of a paste containing 3.3×10(9) CFU of SB CNCM I-107(9). Piglets from the control litters received a placebo paste. Piglet weight, mortality and diarrhoea were recorded up to day 7 of age. It was shown that numbers of diarrhoea days were significantly correlated with increased mortality rate and reduced weight gain (P<0.05). SB treatment had no effect on growth or mortality in diarrhoeic litters. However, SB-supplemented litters had significantly lower faecal scores, indicating firmer faeces (P<0.01) and fewer numbers of diarrhoeic days (P<0.01) during the 1(st) week of life. Reduction in the number of diarrhoeic litters compared with the control group was observed following the probiotic administration (P<0.05). These results highlight the detrimental effects of neonatal diarrhoea on pre-weaning performance and suggest that SB, by reducing diarrhoea duration and severity, has the potential of improving enteric health in the early stages of life in pigs.
- Published
- 2015
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46. Hypoxia attenuates the proinflammatory response in colon cancer cells by regulating IκB.
- Author
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Müller-Edenborn K, Léger K, Glaus Garzon JF, Oertli C, Mirsaidi A, Richards PJ, Rehrauer H, Spielmann P, Hoogewijs D, Borsig L, Hottiger MO, and Wenger RH
- Subjects
- Cell Hypoxia, Colonic Neoplasms, Humans, Lipopolysaccharides, Signal Transduction, I-kappa B Proteins metabolism, Inflammation metabolism, Inflammatory Bowel Diseases genetics, Inflammatory Bowel Diseases metabolism, NF-kappa B metabolism
- Abstract
Two main features common to all solid tumors are tissue hypoxia and inflammation, both of which cause tumor progression, metastasis, therapy resistance and increased mortality. Chronic inflammation is associated with increased cancer risk, as demonstrated for inflammatory bowel disease patients developing colon cancer. However, the interplay between hypoxia and inflammation on the molecular level remains to be elucidated. We found that MC-38 mouse colon cancer cells contain functional hypoxic (HIF-1α) and inflammatory (p65/RelA) signaling pathways. In contrast to cells of the myeloid lineage, HIF-1α levels remained unaffected in MC-38 cells treated with LPS, and hypoxia failed to induce NF-κB. A similar regulation of canonical HIF and NF-κB target genes confirmed these results. RNA deep sequencing of HIF-1α and p65/RelA knock-down cells revealed that a surprisingly large fraction of HIF target genes required p65/RelA for hypoxic regulation and a number of p65/RelA target genes required HIF-1α for proinflammatory regulation, respectively. Hypoxia attenuated the inflammatory response to LPS by inhibiting nuclear translocation of p65/RelA independently of HIF-1α, which was associated with enhanced IκBα levels and decreased IKKβ phosphorylation. These data demonstrate that the interaction between hypoxic and inflammatory signaling pathways needs to be considered when designing cancer therapies targeting HIF or NF-κB.
- Published
- 2015
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47. ARTD1-induced poly-ADP-ribose formation enhances PPARγ ligand binding and co-factor exchange.
- Author
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Lehmann M, Pirinen E, Mirsaidi A, Kunze FA, Richards PJ, Auwerx J, and Hottiger MO
- Subjects
- Adipose Tissue, White drug effects, Animals, Cell Line, Cell Size drug effects, DNA Topoisomerases, Type II metabolism, Diet, High-Fat, Ligands, Male, Mice, Mice, Inbred C57BL, Peroxisome Proliferator-Activated Receptors antagonists & inhibitors, Poly (ADP-Ribose) Polymerase-1, Response Elements, Weight Gain drug effects, Adipogenesis genetics, PPAR gamma metabolism, Poly Adenosine Diphosphate Ribose biosynthesis, Poly(ADP-ribose) Polymerases metabolism, Transcriptional Activation
- Abstract
PPARγ-dependent gene expression during adipogenesis is facilitated by ADP-ribosyltransferase D-type 1 (ARTD1; PARP1)-catalyzed poly-ADP-ribose (PAR) formation. Adipogenesis is accompanied by a dynamic modulation of the chromatin landscape at PPARγ target genes by ligand-dependent co-factor exchange. However, how endogenous PPARγ ligands, which have a low affinity for the receptor and are present at low levels in the cell, can induce sufficient co-factor exchange is unknown. Moreover, the significance of PAR formation in PPARγ-regulated adipose tissue function is also unknown. Here, we show that inhibition of PAR formation in mice on a high-fat diet reduces weight gain and cell size of adipocytes, as well as PPARγ target gene expression in white adipose tissue. Mechanistically, topoisomerase II activity induces ARTD1 recruitment to PPARγ target genes, and ARTD1 automodification enhances ligand binding to PPARγ, thus promoting sufficient transcriptional co-factor exchange in adipocytes. Thus, ARTD1-mediated PAR formation during adipogenesis is necessary to adequately convey the low signal of endogenous PPARγ ligand to effective gene expression. These results uncover a new regulatory mechanism of ARTD1-induced ADP-ribosylation and highlight its importance for nuclear factor-regulated gene expression., (© The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.)
- Published
- 2015
- Full Text
- View/download PDF
48. Assessment of caecal parameters in layer hens fed on diets containing wheat distillers dried grains with solubles.
- Author
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White GA, Richards PJ, Wu S, Mellits KH, and Wiseman J
- Subjects
- Animal Feed analysis, Animals, Bacteria isolation & purification, Cecum drug effects, DNA, Bacterial analysis, Diet veterinary, Dose-Response Relationship, Drug, Edible Grain chemistry, Female, Random Allocation, Animal Nutritional Physiological Phenomena drug effects, Cecum metabolism, Cecum microbiology, Chickens physiology, Triticum chemistry
- Abstract
There is much interest in quantifying the nutritional value of UK wheat distillers dried grains with solubles (W-DDGS) for livestock species. A study was designed to evaluate caecal parameters (pH, short chain fatty acids (SCFAs) and bacterial diversity) in layer hens fed on balanced diets containing graded concentrations of W-DDGS. A total of 32 layer hens (Bovans Brown strain at 27 weeks of age) were randomly allocated to one of 4 dietary treatments containing W-DDGS at 0, 60, 120 or 180 g/kg. Each treatment was fed to 8 replicate individually housed layer hens over a 5-d acclimatisation period, followed by a 4-week trial. Individual feed intakes were monitored and all eggs were collected daily for weeks 2, 3 and 4 of the trial, weighed and an assessment of eggshell "dirtiness" made. All hens were culled on d 29 and caecal pH and SCFAs measured. Polymerase chain reaction denaturing gradient gel electrophoresis of the bacterial 16 S rDNA gene was used to assess total bacterial diversity of luminal caecal content from hens fed the 0 and 180 g W-DDGS/kg diets. Unweighted pair group method with arithmetic mean (UPGMA) dendrograms were generated from DGGE banding patterns. Increasing W-DDGS dietary concentrations resulted in a more acidic caecal environment. Caecal SCFAs were unaffected by diet aside from a quadratic effect for molar proportions of isobutyric acid. Diversity profiles of the bacterial 16S rRNA gene from luminal caecal contents were unaffected by W-DDGS inclusion. The results of the current study suggest that W-DDGS can be successfully formulated into nutritionally balanced layer diets (supplemented with xylanase and phytase) at up to 180 g/kg with no detrimental effects to the caecal environment.
- Published
- 2015
- Full Text
- View/download PDF
49. Therapeutic potential of adipose-derived stromal cells in age-related osteoporosis.
- Author
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Mirsaidi A, Genelin K, Vetsch JR, Stanger S, Theiss F, Lindtner RA, von Rechenberg B, Blauth M, Müller R, Kuhn GA, Hofmann Boss S, Ebner HL, and Richards PJ
- Subjects
- Age Factors, Animals, Cell Differentiation, Cells, Cultured, Humans, Male, Mesenchymal Stem Cells cytology, Mice, Osteoporosis epidemiology, Osteoporosis pathology, Stromal Cells cytology, Tibia cytology, Tibia pathology, Adipose Tissue cytology, Osteogenesis, Osteoporosis therapy, Stromal Cells transplantation
- Abstract
Adipose-derived stromal cells (ASCs) are increasingly being used for orthopedic-based tissue engineering approaches due to their ability to readily undergo osteogenic differentiation. In the present study, we used in vitro and in vivo approaches to evaluate the use of ASCs as a treatment strategy for age-related osteoporosis. Molecular, histological and micro-computed tomography (micro-CT) based approaches confirmed that ASCs isolated from 18-week-old osteoporotic senescence-accelerated mice (SAMP6) were capable of undergoing osteogenesis when cultured in either silk fibroin (SF) scaffolds or scaffold-free microtissues (ASC-MT). A single intratibial injection of CM-Dil-labeled isogeneic ASCs or ASC-MT into SAMP6 recipients significantly improved trabecular bone quality after 6 weeks in comparison to untreated contralateral bones, as determined by micro-CT. Injected ASCs could be observed in paraffin wax bone sections at 24 h and 6 weeks post treatment and induced a significant increase in several molecular markers of bone turnover. Furthermore, a significant improvement in the osteogenic potential of osteoporotic patient-derived human bone marrow stromal cells (BMSCs) was observed when differentiated in conditioned culture media harvested from osteoporotic patient-derived human ASCs. These findings therefore support the use of ASCs as an autologous cell-based approach for the treatment of osteoporosis., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
50. Osteoanabolic effect of alendronate and zoledronate on bone marrow stromal cells (BMSCs) isolated from aged female osteoporotic patients and its implications for their mode of action in the treatment of age-related bone loss.
- Author
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Lindtner RA, Tiaden AN, Genelin K, Ebner HL, Manzl C, Klawitter M, Sitte I, von Rechenberg B, Blauth M, and Richards PJ
- Subjects
- Aged, Aged, 80 and over, Alendronate therapeutic use, Alkaline Phosphatase metabolism, Bone Density drug effects, Bone Density Conservation Agents therapeutic use, Cell Differentiation drug effects, Cells, Cultured, Female, Humans, Mesenchymal Stem Cells enzymology, Mesenchymal Stem Cells pathology, Osteogenesis drug effects, Osteopontin physiology, Osteoporosis, Postmenopausal drug therapy, Osteoporosis, Postmenopausal physiopathology, Zoledronic Acid, Alendronate pharmacology, Bone Density Conservation Agents pharmacology, Diphosphonates pharmacology, Imidazoles pharmacology, Mesenchymal Stem Cells drug effects, Osteoporosis, Postmenopausal pathology
- Abstract
Summary: In the present study, we evaluated the potential for aminobisphosphonates to enhance the development of bone-forming osteoblasts from progenitor cells isolated from aged female osteoporotic patients. The aminobisphosphonates tested significantly enhanced osteoblast formation and thus lend further insights into their possible mode of action in the treatment of osteoporosis., Introduction: The primary aim of this study was to evaluate the influence of aminobisphosphonates on the osteogenesis of human bone marrow stromal cells (hBMSCs) and mineralization of differentiating bone-forming cells isolated from osteoporotic patients., Methods: The influence of aminobisphosphonate treatment on hBMSC osteogenesis was assessed by the quantitative measurement of alkaline phosphatase (ALP) activity, in addition to quantitative reverse transcription polymerase chain reaction and Western blot analysis of known osteogenic markers. Mineralized matrix formation by hBMSC-derived osteoblasts was visualized and quantified using Alizarin red staining., Results: hBMSC cultures treated with osteogenic medium supplemented with zoledronate demonstrated a significant increase in Alizarin red staining after 3 weeks as compared to cells cultured in osteogenic medium alone. Similarly, cultures of differentiating hBMSCs isolated from patients receiving alendronate treatment also demonstrated an increased propensity for mineralization, even in the absence of further in vitro stimulation by zoledronate. The stimulatory effects of aminobisphosphonate treatment on hBMSC-derived osteoblast-mediated mineralization were independent of any alterations in ALP activity, although significant decreases in the expression levels of osteopontin (SPP1) were evident in hBMSCs following exposure to aminobisphosphonates. Further analysis including Western blotting and loss-of-function studies revealed osteopontin as having a negative influence on the mineralization of differentiating osteoporotic bone-forming cells., Conclusions: The results presented here demonstrate for the first time that aminobisphosphonate treatment of osteoporotic hBMSCs enhances their capacity for osteoblast formation and subsequent mineral deposition, thus supporting the concept of aminobisphosphonates as having an osteoanabolic effect in osteoporosis.
- Published
- 2014
- Full Text
- View/download PDF
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