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Jakosky BM, Grebowsky JM, Luhmann JG, Connerney J, Eparvier F, Ergun R, Halekas J, Larson D, Mahaffy P, McFadden J, Mitchell DF, Schneider N, Zurek R, Bougher S, Brain D, Ma YJ, Mazelle C, Andersson L, Andrews D, Baird D, Baker D, Bell JM, Benna M, Chaffin M, Chamberlin P, Chaufray YY, Clarke J, Collinson G, Combi M, Crary F, Cravens T, Crismani M, Curry S, Curtis D, Deighan J, Delory G, Dewey R, DiBraccio G, Dong C, Dong Y, Dunn P, Elrod M, England S, Eriksson A, Espley J, Evans S, Fang X, Fillingim M, Fortier K, Fowler CM, Fox J, Gröller H, Guzewich S, Hara T, Harada Y, Holsclaw G, Jain SK, Jolitz R, Leblanc F, Lee CO, Lee Y, Lefevre F, Lillis R, Livi R, Lo D, Mayyasi M, McClintock W, McEnulty T, Modolo R, Montmessin F, Morooka M, Nagy A, Olsen K, Peterson W, Rahmati A, Ruhunusiri S, Russell CT, Sakai S, Sauvaud JA, Seki K, Steckiewicz M, Stevens M, Stewart AIF, Stiepen A, Stone S, Tenishev V, Thiemann E, Tolson R, Toublanc D, Vogt M, Weber T, Withers P, Woods T, Yelle R. MAVEN observations of the response of Mars to an interplanetary coronal mass ejection. Science 2015; 350:aad0210. [PMID: 26542576 DOI: 10.1126/science.aad0210] [Citation(s) in RCA: 134] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Coupling between the lower and upper atmosphere, combined with loss of gas from the upper atmosphere to space, likely contributed to the thin, cold, dry atmosphere of modern Mars. To help understand ongoing ion loss to space, the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft made comprehensive measurements of the Mars upper atmosphere, ionosphere, and interactions with the Sun and solar wind during an interplanetary coronal mass ejection impact in March 2015. Responses include changes in the bow shock and magnetosheath, formation of widespread diffuse aurora, and enhancement of pick-up ions. Observations and models both show an enhancement in escape rate of ions to space during the event. Ion loss during solar events early in Mars history may have been a major contributor to the long-term evolution of the Mars atmosphere.
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Affiliation(s)
| | - J M Grebowsky
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - J G Luhmann
- University of California at Berkeley, Berkeley, CA, USA
| | - J Connerney
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - F Eparvier
- University of Colorado, Boulder, CO, USA
| | - R Ergun
- University of Colorado, Boulder, CO, USA
| | - J Halekas
- University of Iowa, Iowa City, IA, USA
| | - D Larson
- University of California at Berkeley, Berkeley, CA, USA
| | - P Mahaffy
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - J McFadden
- University of California at Berkeley, Berkeley, CA, USA
| | - D F Mitchell
- University of California at Berkeley, Berkeley, CA, USA
| | | | - R Zurek
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - S Bougher
- University of Michigan, Ann Arbor, MI, USA
| | - D Brain
- University of Colorado, Boulder, CO, USA
| | - Y J Ma
- University of California at Los Angeles, Los Angeles, CA, USA
| | - C Mazelle
- CNRS-Institut de Recherche en Astrophysique et Planétologie (IRAP), Toulouse, France. University Paul Sabatier, Toulouse, France
| | | | - D Andrews
- Swedish Institute of Space Physics, Uppsala, Sweden
| | - D Baird
- NASA/Johnson Space Center, Houston, TX, USA
| | - D Baker
- University of Colorado, Boulder, CO, USA
| | - J M Bell
- National Institute of Aerospace, Hampton, VA, USA
| | - M Benna
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - M Chaffin
- University of Colorado, Boulder, CO, USA
| | - P Chamberlin
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - Y-Y Chaufray
- Laboratoire atmosphères, milieux et observations spatiales (LATMOS)-CNRS, Paris, France
| | - J Clarke
- Boston University, Boston, MA, USA
| | - G Collinson
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - M Combi
- University of Michigan, Ann Arbor, MI, USA
| | - F Crary
- University of Colorado, Boulder, CO, USA
| | - T Cravens
- University of Kansas, Lawrence, KS, USA
| | - M Crismani
- University of Colorado, Boulder, CO, USA
| | - S Curry
- University of California at Berkeley, Berkeley, CA, USA
| | - D Curtis
- University of California at Berkeley, Berkeley, CA, USA
| | - J Deighan
- University of Colorado, Boulder, CO, USA
| | - G Delory
- University of California at Berkeley, Berkeley, CA, USA
| | - R Dewey
- University of Colorado, Boulder, CO, USA
| | - G DiBraccio
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - C Dong
- University of Michigan, Ann Arbor, MI, USA
| | - Y Dong
- University of Colorado, Boulder, CO, USA
| | - P Dunn
- University of California at Berkeley, Berkeley, CA, USA
| | - M Elrod
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - S England
- University of California at Berkeley, Berkeley, CA, USA
| | - A Eriksson
- Swedish Institute of Space Physics, Uppsala, Sweden
| | - J Espley
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - S Evans
- Computational Physics, Inc., Boulder, CO, USA
| | - X Fang
- University of Colorado, Boulder, CO, USA
| | - M Fillingim
- University of California at Berkeley, Berkeley, CA, USA
| | - K Fortier
- University of Colorado, Boulder, CO, USA
| | - C M Fowler
- University of Colorado, Boulder, CO, USA
| | - J Fox
- Wright State University, Dayton, OH, USA
| | - H Gröller
- University of Arizona, Tucson, AZ, USA
| | - S Guzewich
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - T Hara
- University of California at Berkeley, Berkeley, CA, USA
| | - Y Harada
- University of California at Berkeley, Berkeley, CA, USA
| | - G Holsclaw
- University of Colorado, Boulder, CO, USA
| | - S K Jain
- University of Colorado, Boulder, CO, USA
| | - R Jolitz
- University of California at Berkeley, Berkeley, CA, USA
| | - F Leblanc
- Laboratoire atmosphères, milieux et observations spatiales (LATMOS)-CNRS, Paris, France
| | - C O Lee
- University of California at Berkeley, Berkeley, CA, USA
| | - Y Lee
- University of Michigan, Ann Arbor, MI, USA
| | - F Lefevre
- Laboratoire atmosphères, milieux et observations spatiales (LATMOS)-CNRS, Paris, France
| | - R Lillis
- University of California at Berkeley, Berkeley, CA, USA
| | - R Livi
- University of California at Berkeley, Berkeley, CA, USA
| | - D Lo
- University of Arizona, Tucson, AZ, USA
| | | | | | - T McEnulty
- University of Colorado, Boulder, CO, USA
| | - R Modolo
- Laboratoire atmosphères, milieux et observations spatiales (LATMOS)-CNRS, Paris, France
| | - F Montmessin
- Laboratoire atmosphères, milieux et observations spatiales (LATMOS)-CNRS, Paris, France
| | - M Morooka
- University of Colorado, Boulder, CO, USA
| | - A Nagy
- University of Michigan, Ann Arbor, MI, USA
| | - K Olsen
- University of Michigan, Ann Arbor, MI, USA
| | - W Peterson
- University of Colorado, Boulder, CO, USA
| | - A Rahmati
- University of Kansas, Lawrence, KS, USA
| | | | - C T Russell
- University of California at Los Angeles, Los Angeles, CA, USA
| | - S Sakai
- University of Kansas, Lawrence, KS, USA
| | - J-A Sauvaud
- CNRS-Institut de Recherche en Astrophysique et Planétologie (IRAP), Toulouse, France. University Paul Sabatier, Toulouse, France
| | - K Seki
- Nagoya University, Nagoya, Japan
| | - M Steckiewicz
- CNRS-Institut de Recherche en Astrophysique et Planétologie (IRAP), Toulouse, France. University Paul Sabatier, Toulouse, France
| | - M Stevens
- Naval Research Laboratory, Washington, DC, USA
| | | | - A Stiepen
- University of Colorado, Boulder, CO, USA
| | - S Stone
- University of Arizona, Tucson, AZ, USA
| | - V Tenishev
- University of Michigan, Ann Arbor, MI, USA
| | - E Thiemann
- University of Colorado, Boulder, CO, USA
| | - R Tolson
- North Carolina State University, Raleigh, NC, USA
| | - D Toublanc
- CNRS-Institut de Recherche en Astrophysique et Planétologie (IRAP), Toulouse, France. University Paul Sabatier, Toulouse, France
| | - M Vogt
- Boston University, Boston, MA, USA
| | - T Weber
- University of Colorado, Boulder, CO, USA
| | | | - T Woods
- University of Colorado, Boulder, CO, USA
| | - R Yelle
- University of Arizona, Tucson, AZ, USA
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Bougher S, Jakosky B, Halekas J, Grebowsky J, Luhmann J, Mahaffy P, Connerney J, Eparvier F, Ergun R, Larson D, McFadden J, Mitchell D, Schneider N, Zurek R, Mazelle C, Andersson L, Andrews D, Baird D, Baker DN, Bell JM, Benna M, Brain D, Chaffin M, Chamberlin P, Chaufray JY, Clarke J, Collinson G, Combi M, Crary F, Cravens T, Crismani M, Curry S, Curtis D, Deighan J, Delory G, Dewey R, DiBraccio G, Dong C, Dong Y, Dunn P, Elrod M, England S, Eriksson A, Espley J, Evans S, Fang X, Fillingim M, Fortier K, Fowler CM, Fox J, Gröller H, Guzewich S, Hara T, Harada Y, Holsclaw G, Jain SK, Jolitz R, Leblanc F, Lee CO, Lee Y, Lefevre F, Lillis R, Livi R, Lo D, Ma Y, Mayyasi M, McClintock W, McEnulty T, Modolo R, Montmessin F, Morooka M, Nagy A, Olsen K, Peterson W, Rahmati A, Ruhunusiri S, Russell CT, Sakai S, Sauvaud JA, Seki K, Steckiewicz M, Stevens M, Stewart AIF, Stiepen A, Stone S, Tenishev V, Thiemann E, Tolson R, Toublanc D, Vogt M, Weber T, Withers P, Woods T, Yelle R. Early MAVEN Deep Dip campaign reveals thermosphere and ionosphere variability. Science 2015; 350:aad0459. [PMID: 26542579 DOI: 10.1126/science.aad0459] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The Mars Atmosphere and Volatile Evolution (MAVEN) mission, during the second of its Deep Dip campaigns, made comprehensive measurements of martian thermosphere and ionosphere composition, structure, and variability at altitudes down to ~130 kilometers in the subsolar region. This altitude range contains the diffusively separated upper atmosphere just above the well-mixed atmosphere, the layer of peak extreme ultraviolet heating and primary reservoir for atmospheric escape. In situ measurements of the upper atmosphere reveal previously unmeasured populations of neutral and charged particles, the homopause altitude at approximately 130 kilometers, and an unexpected level of variability both on an orbit-to-orbit basis and within individual orbits. These observations help constrain volatile escape processes controlled by thermosphere and ionosphere structure and variability.
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Affiliation(s)
- S Bougher
- CLaSP Department, University of Michigan, Ann Arbor, MI, USA.
| | - B Jakosky
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - J Halekas
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA, USA
| | - J Grebowsky
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - J Luhmann
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - P Mahaffy
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - J Connerney
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - F Eparvier
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - R Ergun
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - D Larson
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - J McFadden
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - D Mitchell
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - N Schneider
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - R Zurek
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - C Mazelle
- CNRS/Institut de Recherche en Astrophysique et Planétologie, Toulouse, France. University Paul Sabatier, Toulouse, France
| | - L Andersson
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - D Andrews
- Swedish Institute of Space Physics, Kiruna, Sweden
| | - D Baird
- NASA/Johnson Space Center, Houston, TX, USA
| | - D N Baker
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - J M Bell
- National Institute of Aerospace, Hampton, VA, USA
| | - M Benna
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - D Brain
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - M Chaffin
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - P Chamberlin
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - J-Y Chaufray
- Laboratoire Atmosphères, Milieux, Observations Spatiales /CNRS, Verrieres-le-Buisson, France
| | - J Clarke
- Department of Astronomy, Boston University, Boston, MA, USA
| | - G Collinson
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - M Combi
- CLaSP Department, University of Michigan, Ann Arbor, MI, USA
| | - F Crary
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - T Cravens
- Department of Physics and Astronomy, University of Kansas, Lawrence, KS, USA
| | - M Crismani
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - S Curry
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - D Curtis
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - J Deighan
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - G Delory
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - R Dewey
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - G DiBraccio
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - C Dong
- CLaSP Department, University of Michigan, Ann Arbor, MI, USA
| | - Y Dong
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - P Dunn
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - M Elrod
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - S England
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - A Eriksson
- Swedish Institute of Space Physics, Kiruna, Sweden
| | - J Espley
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - S Evans
- Computational Physics, Springfield, VA, USA
| | - X Fang
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - M Fillingim
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - K Fortier
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - C M Fowler
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - J Fox
- Department of Physics, Wright State University, Fairborn, OH, USA
| | - H Gröller
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - S Guzewich
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - T Hara
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - Y Harada
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - G Holsclaw
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - S K Jain
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - R Jolitz
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - F Leblanc
- Laboratoire Atmosphères, Milieux, Observations Spatiales /CNRS, Verrieres-le-Buisson, France
| | - C O Lee
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - Y Lee
- CLaSP Department, University of Michigan, Ann Arbor, MI, USA
| | - F Lefevre
- Laboratoire Atmosphères, Milieux, Observations Spatiales /CNRS, Verrieres-le-Buisson, France
| | - R Lillis
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - R Livi
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - D Lo
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - Y Ma
- Institute of Geophysics and Planetary Physics, University of California, Los Angeles, Los Angeles, CA, USA
| | - M Mayyasi
- Department of Astronomy, Boston University, Boston, MA, USA
| | - W McClintock
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - T McEnulty
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - R Modolo
- Laboratoire Atmosphères, Milieux, Observations Spatiales /CNRS, Verrieres-le-Buisson, France
| | - F Montmessin
- Laboratoire Atmosphères, Milieux, Observations Spatiales /CNRS, Verrieres-le-Buisson, France
| | - M Morooka
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - A Nagy
- CLaSP Department, University of Michigan, Ann Arbor, MI, USA
| | - K Olsen
- CLaSP Department, University of Michigan, Ann Arbor, MI, USA
| | - W Peterson
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - A Rahmati
- Department of Physics and Astronomy, University of Kansas, Lawrence, KS, USA
| | - S Ruhunusiri
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA, USA
| | - C T Russell
- Institute of Geophysics and Planetary Physics, University of California, Los Angeles, Los Angeles, CA, USA
| | - S Sakai
- Department of Physics and Astronomy, University of Kansas, Lawrence, KS, USA
| | - J-A Sauvaud
- CNRS/Institut de Recherche en Astrophysique et Planétologie, Toulouse, France. University Paul Sabatier, Toulouse, France
| | - K Seki
- Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya, Aichi, Japan
| | - M Steckiewicz
- CNRS/Institut de Recherche en Astrophysique et Planétologie, Toulouse, France. University Paul Sabatier, Toulouse, France
| | - M Stevens
- Naval Research Laboratory, Washington, DC, USA
| | - A I F Stewart
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - A Stiepen
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - S Stone
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - V Tenishev
- CLaSP Department, University of Michigan, Ann Arbor, MI, USA
| | - E Thiemann
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - R Tolson
- National Institute of Aerospace, Hampton, VA, USA
| | - D Toublanc
- CNRS/Institut de Recherche en Astrophysique et Planétologie, Toulouse, France. University Paul Sabatier, Toulouse, France
| | - M Vogt
- Department of Astronomy, Boston University, Boston, MA, USA
| | - T Weber
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - P Withers
- Department of Astronomy, Boston University, Boston, MA, USA
| | - T Woods
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - R Yelle
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
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Cohen O, Ma Y, Drake JJ, Glocer A, Garraffo C, Bell JM, Gombosi TI. THE INTERACTION OF VENUS-LIKE, M-DWARF PLANETS WITH THE STELLAR WIND OF THEIR HOST STAR. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/0004-637x/806/1/41] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Westlake JH, Waite JH, Mandt KE, Carrasco N, Bell JM, Magee BA, Wahlund JE. Titan's ionospheric composition and structure: Photochemical modeling of Cassini INMS data. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011je003883] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Westlake JH, Bell JM, Waite JH, Johnson RE, Luhmann JG, Mandt KE, Magee BA, Rymer AM. Titan's thermospheric response to various plasma environments. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010ja016251] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- J. H. Westlake
- Department of Physics and Astronomy; University of Texas at San Antonio; San Antonio Texas USA
| | - J. M. Bell
- Space Science and Engineering Division; Southwest Research Institute; San Antonio Texas USA
| | - J. H. Waite
- Department of Physics and Astronomy; University of Texas at San Antonio; San Antonio Texas USA
- Space Science and Engineering Division; Southwest Research Institute; San Antonio Texas USA
| | - R. E. Johnson
- Engineering Physics Program; University of Virginia; Charlottesville Virginia USA
| | - J. G. Luhmann
- Space Sciences Laboratory; University of California; Berkeley California USA
| | - K. E. Mandt
- Space Science and Engineering Division; Southwest Research Institute; San Antonio Texas USA
- Department of Environmental and Civil Engineering; University of Texas at San Antonio; San Antonio Texas USA
| | - B. A. Magee
- Space Science and Engineering Division; Southwest Research Institute; San Antonio Texas USA
| | - A. M. Rymer
- Johns Hopkins University Applied Physics Laboratory; Laurel Maryland USA
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Jômting Å, Ben-Nissan B, Ashcroft I, Swain MV, Bell JM. Studies of Ultra Micro Indented Multilayered Sol-Gel Zirconia Films. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-356-711] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractThe deformation behavior of sol-gel derived zirconia films during ultra micro indentation has been investigated. The sol-gel films were deposited using a multiple stage coating procedure onto stainless steel substrates. The indentation process was carried out using both pointed indenters, such as a Berkovich, as well as spherical indenters. The use of different indenter types enables the determination of hardness, elastic modulus as well as the elastic-plastic or elastic-brittle transition of the films. The mechanical behavior of thin films is strongly influenced by the interaction between the substrate and the film. In brittle materials, the stress singularities induced by the indentation process cannot readily be reduced by long range plastic flow and may cause cracking. Therefore, a great deal of attention has been paid to post-indentation observations of the films, in particular examinations of the surface morphology for visible traces of the film behavior during indentation.
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Castanheira M, Bell JM, Turnidge JD, Mendes RE, Jones RN. Dissemination and genetic context analysis of bla(VIM-6) among Pseudomonas aeruginosa isolates in Asian-Pacific Nations. Clin Microbiol Infect 2009; 16:186-9. [PMID: 19673963 DOI: 10.1111/j.1469-0691.2009.02903.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
VIM-6, previously reported in two strains from Singapore recovered in 2000, was detected in 16 isolates collected in 2006 in India (12 isolates), Indonesia (two), Korea and the Philippines (one each). High genetic variability was observed among VIM-6-producing isolates (12 ribotypes and 11 pulsed-field gel electrophoresis types), but clones were observed in India and Indonesia; bla(VIM-6)-carrying integrons of 3.9 kb and 5 kb were detected, and two of five Indian hospitals yielded isolates with both integrons. These two integrons, bla(VIM-6) was located in the first position, followed by bla(OXA-10) and aacA4. The 5-kb integrons also harboured aadA1 and a 331-bp open reading frame encoding a putative efflux pump.
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Affiliation(s)
| | - J. H. Waite
- Southwest Research Institute; San Antonio Texas USA
| | - T. E. Cravens
- Department of Physics and Astronomy; University of Kansas; Lawrence Kansas USA
| | - S. W. Bougher
- Department of Atmospheric, Oceanic and Space Sciences; University of Michigan; Ann Arbor Michigan USA
| | - I. P. Robertson
- Department of Physics and Astronomy; University of Kansas; Lawrence Kansas USA
| | - J. M. Bell
- Southwest Research Institute; San Antonio Texas USA
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Murray RJ, Pearson JC, Coombs GW, Flexman JP, Golledge CL, Speers DJ, Dyer JR, McLellan DG, Reilly M, Bell JM, Bowen SF, Christiansen KJ. Outbreak of invasive methicillin-resistant Staphylococcus aureus infection associated with acupuncture and joint injection. Infect Control Hosp Epidemiol 2008; 29:859-65. [PMID: 18684094 DOI: 10.1086/590260] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To describe an outbreak of invasive methicillin-resistant Staphylococcus aureus (MRSA) infection after percutaneous needle procedures (acupuncture and joint injection) performed by a single medical practitioner. SETTING A medical practitioner's office and 4 hospitals in Perth, Western Australia. PATIENTS Eight individuals who developed invasive MRSA infection after acupuncture or joint injection performed by the medical practitioner. METHODS We performed a prospective and retrospective outbreak investigation, including MRSA colonization surveillance, environmental sampling for MRSA, and detailed molecular typing of MRSA isolates. We performed an infection control audit of the medical practitioner's premises and practices and administered MRSA decolonization therapy to the medical practitioner. RESULTS Eight cases of invasive MRSA infection were identified. Seven cases occurred as a cluster in May 2004; another case (identified retrospectively) occurred approximately 15 months earlier in February 2003. The primary sites of infection were the neck, shoulder, lower back, and hip: 5 patients had septic arthritis and bursitis, and 3 had pyomyositis; 3 patients had bacteremia, including 1 patient with possible endocarditis. The medical practitioner was found to be colonized with the same MRSA clone [ST22-MRSA-IV (EMRSA-15)] at 2 time points: shortly after the first case of infection in March 2003 and again in May 2004. After the medical practitioner's premises and practices were audited and he himself received MRSA decolonization therapy, no further cases were identified. CONCLUSIONS This outbreak most likely resulted from a breakdown in sterile technique during percutaneous needle procedures, resulting in the transmission of MRSA from the medical practitioner to the patients. This report demonstrates the importance of surveillance and molecular typing in the identification and control of outbreaks of MRSA infection.
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Affiliation(s)
- R J Murray
- Department of Microbiology and Infectious Diseases, PathWest Laboratory Medicine WA-Royal Perth Hospital, West Perth, Perth, Western Australia.
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Rybachuk M, Bell JM. Growth of diamond-like carbon films using low energy ion beam sputter - bombardment deposition with Ar ions. ACTA ACUST UNITED AC 2008. [DOI: 10.1088/1742-6596/100/8/082009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Christiansen KJ, Bell JM, Turnidge JD, Jones RN. Antimicrobial activities of garenoxacin (BMS 284756) against Asia-Pacific region clinical isolates from the SENTRY program, 1999 to 2001. Antimicrob Agents Chemother 2004; 48:2049-55. [PMID: 15155198 PMCID: PMC415570 DOI: 10.1128/aac.48.6.2049-2055.2004] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Between 1999 and 2001, 16,731 isolates from the Asia-Pacific Region were tested in the SENTRY Program for susceptibility to six fluoroquinolones including garenoxacin. Garenoxacin was four- to eightfold less active against Enterobacteriaceae than ciprofloxacin, although both drugs inhibited similar percentages at 1 microg/ml. Garenoxacin was more active against gram-positive species than all other fluoroquinolones except gemifloxacin. For Staphylococcus aureus, oxacillin resistance was high in many participating countries (Japan, 67%; Taiwan, 60%; Hong Kong, 55%; Singapore, 52%), with corresponding high levels of ciprofloxacin resistance (57 to 99%) in oxacillin-resistant S. aureus (ORSA). Of the ciprofloxacin-resistant ORSA isolates, the garenoxacin MIC was >4 microg/ml for only 9% of them. For Streptococcus pneumoniae, penicillin nonsusceptibility and macrolide resistance were high in many countries. No relationship was seen between penicillin and garenoxacin susceptibility, with all isolates being susceptible at <2 microg/ml. There was, however, a partial correlation between ciprofloxacin and garenoxacin MICs. For ciprofloxacin-resistant isolates for which garenoxacin MICs were 0.25 to 1 microg/liter, mutations in both the ParC and GyrA regions of the quinolone resistance-determining region could be demonstrated. No mutations conferring high-level resistance were detected. Garenoxacin shows useful activity against a wide range of organisms from the Asia-Pacific region. In particular, it has good activity against S. aureus and S. pneumoniae, although there is evidence that low-level resistance is present in those organisms with ciprofloxacin resistance.
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Bell JM. Image-guided spine intervention. By D S Fenton and L F Czervionke, pp. xv + 298, 2003 (W.B. Saunders Co. Ltd, Philadelphia, PA), £120.00 ISBN 0-7216-0021-2. Br J Radiol 2004. [DOI: 10.1259/bjr.77.919.770626b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Bell JM, Turnidge JD, Jones RN. Prevalence of extended-spectrum beta-lactamase-producing Enterobacter cloacae in the Asia-Pacific region: results from the SENTRY Antimicrobial Surveillance Program, 1998 to 2001. Antimicrob Agents Chemother 2004; 47:3989-93. [PMID: 14638518 PMCID: PMC296176 DOI: 10.1128/aac.47.12.3989-3993.2003] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enterobacter cloacae strains from hospitalized patients with a range of infections were collected by 17 laboratories in the Asia-Pacific region and South Africa. Isolates for which ceftriaxone MICs were above 1 microg/ml and/or ceftazidime MICs were above 2 microg/ml, as well as 46 strains for which ceftriaxone and/or ceftazidime MICs were at or below these values, were screened for levels of extended-spectrum beta-lactamase (ESBL) production through the use of broth microdilution for the detection of clavulanate enhancement of the activity of ceftriaxone, ceftazidime, and cefepime. Of the isolates examined, ceftriaxone and/or ceftazidime had elevated MICs for 44%, of which 36% were ESBL positive. ESBL-positive strains were commonly susceptible to piperacillin-tazobactam and more frequently resistant to several other antimicrobials studied. A cefepime MIC above 0.25 microg/ml had the highest sensitivity (100%) and specificity (74%) for predicting the presence of an ESBL.
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Affiliation(s)
- J M Bell
- Microbiology and Infectious Diseases Department, Women's and Children's Hospital, Adelaide, Australia.
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Abstract
Pollinators often visit several flowers in sequence on plants with large floral displays. This foraging pattern is expected to influence the rate of self-fertilization in self-compatible taxa. To quantify the effects of daily floral display on pollinator movements and selfing, we experimentally manipulated flower number in four replicate (cloned) arrays of Mimulus ringens (Scrophulariaceae), each consisting of genets with unique combinations of homozygous marker genotypes. Four display classes (two, four, eight and 16 flowers) were present in each array. Pollinator visitation rate per flower and seed set per fruit were unaffected by display. However, flower number strongly influenced the frequency of within-plant pollinator movements, which increased from 13.8% of probes on two-flower displays to 77.6% of probes on 16-flower displays. The proportion of within-plant movements was significantly correlated with selfing (r = 0.993). The increase from 22.9% selfing on two-flower displays to 37.3% selfing on 16-flower displays reflects changes in the extent of geitonogamous self-pollination. We estimate that approximately half of all selfing on 16-flower displays resulted from geitonogamy. Selfing also varied dramatically among fruits within display classes. Nested ANOVA indicates that differences among flowers on two-flower ramets accounted for 45.4% of the variation in selfing, differences among genets accounted for 16.1% of the variation, and statistical and sampling error accounted for 38.5% of the variation. Differences among flowers within ramets may reflect the order of sequential floral probes on a display.
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Affiliation(s)
- J D Karron
- Department of Biological Sciences, PO Box 413, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA.
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Bell JM, Turnidge JD, Jones RN. Antimicrobial resistance trends in community-acquired respiratory tract pathogens in the Western Pacific Region and South Africa: report from the SENTRY antimicrobial surveillance program, (1998-1999) including an in vitro evaluation of BMS284756. Int J Antimicrob Agents 2002; 19:125-32. [PMID: 11850165 DOI: 10.1016/s0924-8579(01)00475-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
From 1998 to 1999, a large number of community-acquired respiratory tract isolates of Streptococcus pneumoniae (n=566), Haemophilus influenzae (n=513) and Moraxella catarrhalis (n=228) were collected from 15 centres in Australia, Hong Kong, Japan, China, the Philippines, Singapore, South Africa and Taiwan through the SENTRY Antimicrobial Surveillance Program. Isolates were tested against 26 antimicrobial agents using the NCCLS-recommended methods. Overall, 40% of S. pneumoniae isolates were resistant to penicillin with 18% of strains having high-level resistance (MIC > or =2 mg/l). Rates of erythromycin and clindamycin resistance were 41 and 23%, respectively. Penicillin-resistant strains showed high rates of resistance to other antimicrobial agents: 96% to trimethoprim-sulphamethoxazole (TMP-SMX), 84% to tetracycline and 81% to erythromycin. A significant proportion of penicillin-susceptible strains was also resistant to erythromycin (21%), tetracycline (29%) and TMP-SMZ (26%). Small numbers of strains were resistant to levofloxacin (0.7%), trovafloxacin (0.4%) and grepafloxacin (1.3%) where as all strains remained uniformly susceptible to quinupristin/dalfopristin and BMS284756 (MIC(90), 0.06 mg/l), a new desfluoroquinolone. beta-lactamases were, produced by 20% H. influenzae isolates and only rare strains showed intrinsic resistance to amoxycillin. Other beta-lactam agents showed good activity with rates of resistance less than 2% and all isolates showed susceptibility to cefixime, ceftibuten, cefepime and cefotaxime. Rates of resistance to tetracycline and chloramphenicol were also relatively low at 3%. The majority (98%) of M. catarrhalis isolates was found to be beta-lactamase-positive and resistant to penicillins, however, resistance to erythromycin and tetracycline was also low at 1.8%. Both H. influenzae and M. catarrhalis isolates were uniformly susceptible to the new desfluoroquinolone and tested fluoroquinolones.
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Abstract
OBJECTIVE To determine whether weekly fructosamine testing at home by patients with type 2 diabetes, combined with therapeutic intervention when necessary on the basis of the results, would lead to improved glycemic control in comparison with usual care during a 3-month period. METHODS In a prospective study, 25 patients with glycosylated hemoglobin (HbA1c) values above 8.0% were randomized into 2 groups. Both groups, a glucose-only testing group (14 patients with an initial mean HbA1c of 9.4 +/- 0.9%) and a combined glucose plus fructosamine testing group (11 patients with an initial mean HbA1c of 9.2 +/- 0.7%), received therapeutic intervention at the time of randomization. Both groups were instructed to perform blood glucose testing up to four times per day. The combined glucose plus fructosamine testing group was also instructed to perform weekly fructosamine testing in addition to the glucose testing and to telephone the investigator if their home-testing fructosamine value exceeded 350 mmol/L (approximately equivalent to HbA1c of 7.8%), whereupon the investigator implemented further interventions. Both groups returned in 3 months, at which time HbA1c testing was repeated in order to determine whether glycemic control had changed. RESULTS The study results after 3 months showed that the HbA1c values in the combined glucose plus fructosamine testing group decreased from 9.2 +/- 0.7% to 8.0 +/- 0.5% (P<0.0001). In contrast, the HbA1c values in the glucose-only testing group declined from 9.4 +/- 0.9% to 9.1 +/- 1.3%, a difference that was not significant. CONCLUSION In the 3 months after a change in therapy for type 2 diabetes, weekly home testing of fructosamine, combined with therapeutic interventions based on the results, led to a more rapid and significant improvement in glycemic control than did the usual regimen of glucose-only testing.
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Affiliation(s)
- S V Edelman
- Section of Diabetes and Metabolism, San Diego Veterans Affairs Medical Center, 3350 La Jolla Village Drive, San Diego, CA 92161, USA
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Plank SM, Copeland-Yates SA, Sossey-Alaoui K, Bell JM, Schroer RJ, Skinner C, Michaelis RC. Lack of association of the (AAAT)6 allele of the GXAlu tetranucleotide repeat in intron 27b of the NF1 gene with autism. Am J Med Genet 2001; 105:404-5. [PMID: 11449390 DOI: 10.1002/ajmg.1432] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A novel allele of the GXAlu tetranucleotide repeat in intron 27b of the neurofibromatosis 1 (NF1) gene has recently been reported to be present in 4.7% of autistic patients but not in controls. We have found the novel GXAlu allele absent in 204 patients from the South Carolina Autism Project and 200 controls. The autism population studied includes a significant number of patients with hypotonia, stereotyped behaviors, or postural, gait, and motor abnormalities similar to those seen in the patients previously reported to possess the novel GXAlu allele. This suggests that the novel (AAAT)6 GXAlu allele is not associated with autism.
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Affiliation(s)
- S M Plank
- Presbyterian College, Clinton, South Carolina, USA
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Chang MC, Contreras MA, Rosenberger TA, Rintala JJ, Bell JM, Rapoport SI. Chronic valproate treatment decreases the in vivo turnover of arachidonic acid in brain phospholipids: a possible common effect of mood stabilizers. J Neurochem 2001; 77:796-803. [PMID: 11331408 DOI: 10.1046/j.1471-4159.2001.00311.x] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Both (Li(+)) and valproic acid (VPA) are effective in treating bipolar disorder, but the pathway by which either works, and whether it is common to both drugs, is not agreed upon. We recently reported, using an in vivo fatty acid model, that Li(+) reduces the turnover rate of the second messenger arachidonic acid (AA) by 80% in brain phospholipids of the awake rat, without changing turnover rates of docosahexaenoic or palmitic acid. Reduced AA turnover was accompanied by down-regulation of gene expression and protein levels of an AA-specific cytosolic phospholipase A(2) (cPLA(2)). To see if VPA had the same effect on AA turnover, we used our in vivo fatty acid model in rats chronically administered VPA (200 mg/kg, i.p. for 30 days). Like Li(+), VPA treatment significantly decreased AA turnover within brain phospholipids (by 28-33%), although it had no effect on cPLA(2) protein levels. Thus, both mood stabilizers, Li(+) and VPA have a common action in reducing AA turnover in brain phospholipids, albeit by different mechanisms.
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Affiliation(s)
- M C Chang
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, Maryland 20892-7965, USA.
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Abstract
Australia has a long association methicillin-resistant Staphylococcus aureus (MRSA). Its unique geographic and demographic features have led to the emergence and spread of three types of MRSA over 35 years. Classical multiresistant hospital-acquired MRSA were first noted in Australia in 1965. By the end of the 1970s, strains of this type of MRSA were well established in the complex tertiary care hospitals in the capital cities on the eastern seaboard of mainland Australia. Characterized by resistance to beta-lactams, erythromycin, tetracycline, gentamicin, and trimethoprim-sulfamethoxazole, these strains have persisted and diversified genetically and have acquired a variety of new resistances. They have proven pathogenicity and are a prominent cause of hospital infection in the endemic institutions. More recently they have become endemic in some central state tertiary care hospitals. Community-acquired strains of MRSA first appeared in the north of Western Australia in the mid-1980s. Strains have subsequently appeared in the south of the state and in the two adjacent central states, and are more frequently isolated from Aboriginal patients. Although harboring few or no additional resistances apart from resistance to beta-lactams initially, these strains are also accumulating additional resistances. A different variety of community-acquired MRSA has recently been noted in eastern Australia. It has a similar antibiogram to the western strains, but an entirely different epidemiology, resembling that currently being experienced in parts of New Zealand, and associated with patients of south Pacific island origin.
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Affiliation(s)
- J D Turnidge
- Department of Microbiology and Infectious Diseases, Women's and Children's Hospital, North Adelaide, South Australia, Australia.
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Bell JM, Turnidge JD. Multicentre study of the in vitro activity of cefepime, a broad-spectrum cephalosporin, compared to other broad-spectrum agents. Pathology 2001; 33:53-60. [PMID: 11280610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
The in vitro activity of cefepime was compared to that of a range of other broad-spectrum agents, using a gradient diffusion MIC method, against 995 recent clinical isolates of Enterobacteriaceae, Pseudomonas aeruginosa, other nonfermentative gram-negative bacilli, staphylococci (except oxacillin-resistant Staphylococcus aureus), streptococci, enterococci, and aerobic gram-positive bacilli. Cefepime had excellent activity against Enterobacteriaceae, including eight presumptive extended-spectrum beta-lactamase producers and 33 stably derepressed mutants of natural cephalosporinases. Activity against Pseudomonas aeruginosa was similar to ceftazidime and superior to cefpirome. Its activity against gram-positive cocci was also good, being more active against staphylococci and only slightly less active against streptococci than ceftriaxone. Cefepime maintained activity against bacteria resistant to aminoglycosides and ciprofloxacin. Enterococci, Bacillus species, Burkholderia cepacia and Stenotrophomonas maltophilia were predicably resistant. Cefepime has a spectrum of activity almost as broad as that of the carbapenems.
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Affiliation(s)
- J M Bell
- Department of Microbiology and Infectious Diseases, Women's and Children's Hospital, Adelaide, South Australia
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McKessar SJ, Berry AM, Bell JM, Turnidge JD, Paton JC. Genetic characterization of vanG, a novel vancomycin resistance locus of Enterococcus faecalis. Antimicrob Agents Chemother 2000; 44:3224-8. [PMID: 11036060 PMCID: PMC101640 DOI: 10.1128/aac.44.11.3224-3228.2000] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enterococcus faecalis strain WCH9 displays a moderate level of resistance to vancomycin (MIC = 16 microgram/ml) and full susceptibility to teicoplanin but is negative by PCR analysis using primers specific for all known enterococcal vancomycin resistance genotypes (vanA, vanB, vanC, vanD, and vanE). We have isolated and sequenced a novel putative vancomycin resistance locus (designated vanG), which contains seven open reading frames, from this strain. These are organized differently from those of all the other enterococcal van loci, and, furthermore, the individual vanG gene products exhibit less than 50% amino acid sequence identity to other van gene products.
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Affiliation(s)
- S J McKessar
- Molecular Microbiology Unit, Women's and Children's Hospital, North Adelaide, South Australia 5006, Australia
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Bell JM, Rakow G, Downey RK. Comparisons of amino acid and protein levels in oil-extracted seeds of Brassica and Sinapis species, with observations on environmental effects. Can J Anim Sci 2000. [DOI: 10.4141/a97-117] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Seeds from 21 selections of Brassica and Sinapis were analyzed for crude protein (CP; N × 6.25) and amino acid content following oil extraction and grinding. In exp. 1 three cultivars of B. napus, B. rapa and B. juncea were grown in four locations in 4 successive years, with duplicate samples taken from each plot. Brassica juncea contained more CP (P < 0.001) than B. napus or B. rapa (44.6 > 40.1 > 38.8%, respectively). Location affected CP level but not the ranking among cultivars. Year-to-year effects on CP levels (P < 0.001) were of lower magnitude than location effects. Treatments (cultivar, location, year) affected CP and amino acid levels differently. Amino acid levels expressed as percent of CP differed among many cultivars (P < 0.01). Threonine, valine, histidine, lysine and arginine were strongly influenced by location (P < 0.001), as were the dispensable amino acids serine, glutamine and tyrosine. In exp. 2, 10 cultivars and strains grown in one location and in three replicates resulted in greater CP levels in two B. juncea cultivars than in B. napus and B. rapa (42.9 and 43.2 vs. 39.7 and 38.8%), respectively, but lower levels of lysine and threonine in the CP (lysine: 5.4 vs. 6.3; threonine: 3.5 and 3.7 vs. 3.8 and 4.0%). Brassica napus and B. rapa ranked among the lowest in percent CP. In exp. 3, comparisons of eight samples from B. napus, B. rapa and Sinapis alba plots revealed a CP range of 38.1 to 45.0% but differences in amino acid content of the CP were relatively small. Key words: Brassica, Sinapis, protein, amino acids
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Bell JM, Rakow G, Downey RK. Mineral composition of oil-free seeds of Brassica napus, B. rapa and B. juncea as affected by location and year. Can J Anim Sci 1999. [DOI: 10.4141/a97-116] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Three cultivars of Brassica (Westar, Brassica napus; Tobin, B. rapa; Cutlass, B. juncea) were grown in four locations in 4 successive years, with duplicate samples taken from each treatment. Harvested seed was hexane-extracted, ground and analyzed for mineral content. The average contents (mg kg−1) were: Ca, 0.64; P, 1.12; Mg, 0.56%; Cu, 6.2; Zn, 46; Fe, 188; and Mn, 55. Values for Westar and Tobin were generally similar but Cutlass contained less Ca, Mg, Fe and Mn and more Cu and Zn (P < 0.01). Locations affected all mineral levels. One location produced samples lower in Ca, P, Cu and Mn but higher in Zn than the other locations (P < 0.01). Year-to-year variability was of minor consequence. Key words: Brassica napus, Brassica rapa, Brassica juncea, mineral, seed
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Abstract
Our laboratory has reported that pentobarbital-induced anesthesia reduced the incorporation of intravenously injected radiolabeled palmitic acid into brain phospholipids. To determine if this decrease reflected a pentobarbital-induced decrease in palmitate turnover in phospholipids, we applied our method and model to study net flux and turnover of palmitate in brain phospholipids (1). Awake, light and deep pentobarbital (25-70 mg/kg, iv) anesthetized rats were infused with [9,10-3H]palmitate over a 5 min period. Brain electrical activity was monitored by electroencephalography. An isoelectric electroencephalogram characterized deep pentobarbital anesthesia. Net incorporation rates (J(FA,i)) and turnover rates (Fi) of palmitate were calculated. J(FA,i) for palmitate incorporated into phospholipids was dramatically reduced by pentobarbital treatment in a dose-dependent manner, by 70% and 90% respectively for lightly and deeply anesthetized animals, compared with awake controls. Turnover rates for palmitate in total phospholipid and individual phospholipid classes were decreased by nearly 70% and 90% for lightly and deeply anesthetized animals, respectively. Thus, pentobarbital decreases, in a dose-dependent manner, the turnover of palmitate in brain phospholipids. This suggests that palmitate turnover is closely coupled to brain functional activity.
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Affiliation(s)
- M A Contreras
- Laboratory of Neurosciences, NIA, National Institutes of Health, Bethesda, MD 20892, USA.
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Chang MC, Bell JM, Purdon AD, Chikhale EG, Grange E. Dynamics of docosahexaenoic acid metabolism in the central nervous system: lack of effect of chronic lithium treatment. Neurochem Res 1999; 24:399-406. [PMID: 10215514 DOI: 10.1023/a:1020989701330] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Using a method and model developed in our laboratory to quantitatively study brain phospholipid metabolism, in vivo rates of incorporation and turnover of docosahexaenoic acid in brain phospholipids were measured in awake rats. The results suggest that docosahexaenoate incorporation and turnover in brain phospholipids are more rapid than previously assumed and that this rapid turnover dilutes tracer specific activity in brain docoshexaenoyl-CoA pool due to release and recycling of unlabeled fatty acid from phospholipid metabolism. Fractional turnover rates for docosahexaenoate within phosphatidylinositol, choline glycerophospholipids, ethanolamine glycerophospholipids and phosphatidylserine were 17.7, 3.1, 1.2, and 0.2 %.h(-1), respectively. Chronic lithium treatment, at a brain level considered to be therapeutic in humans (0.6 micromol.g(-1)), had no effect on turnover of docosahexaenoic acid in individual brain phospholipids. Consistent with previous studies from our laboratory that chronic lithium decreased the turnover of arachidonic acid within brain phospholipids by up to 80% and attenuated brain phospholipase A2 activity, the lack of effect of lithium on docosahexaenoate recycling and turnover suggests that a target for lithium's action is an arachidonic acid-selective phospholipase A2.
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Affiliation(s)
- M C Chang
- Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA.
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Abstract
OBJECTIVE To examine the prevalence of resistance in Streptococcus pneumoniae to key antimicrobials in Australia during 1997. DESIGN Prospective, Australia-wide, laboratory-based survey. SETTING 11 microbiology laboratories from seven Australian States and Territories (five private laboratories and six public hospital laboratories) between March and November 1997. STRAINS: Up to 100 consecutive, clinically significant strains of S. pneumoniae isolated by each laboratory. MAIN OUTCOME MEASURES Susceptibility to penicillin, amoxycillin-clavulanate, cefaclor, ceftriaxone, erythromycin, tetracycline, and sulfamethoxazole-trimethoprim (cotrimoxazole), measured by a gradient diffusion, minimum inhibitory concentration technique. RESULTS Of 1020 strains, 16.8% had intermediate susceptibility to penicillin and 8.6% were resistant. Rates of resistance to other drugs were: amoxycillin-clavulanate, 3.1%; cefaclor, 21.4%; ceftriaxone, 3.1%; erythromycin, 15.6%; tetracycline, 15.7%; and cotrimoxazole, 33.4%. Non-invasive isolates harboured more resistances than invasive isolates, and resistance was more prevalent in isolates from children under two years. Multiple resistance was also common, with 21.2% of strains resistant to two or more classes of drug, and 9.3% of non-invasive and 1.7% of invasive isolates resistant to four classes. There were no obvious differences in resistance rates between private and public hospital laboratories. CONCLUSIONS Rates of antimicrobial resistance are rising rapidly in S. pneumoniae in Australia. Recommendations for empiric treatment of invasive and respiratory infection need to take account of these changes.
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Abstract
Following pulse labeling with [3H]arachidonic acid ([3H]AA), its incorporation pattern in brain reflects regional changes in neurotransmitter signal transduction using phospholipase A2, that is, functional activity. In a rat model of Parkinson's disease, unilateral 6-hydroxydopamine lesion in the substantia nigra, [3H]AA acid incorporation from blood was increased in cerebral cortex, caudate putamen, globus pallidus, entopeduncular nucleus, subthalamic nucleus and substantia nigra pars reticulata ipsilateral to the lesion. This increased [3H]AA incorporation likely reflects disinhibition of basal ganglia and cortical circuits secondary to absent inhibitory nigrostriatal dopaminergic input.
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Affiliation(s)
- T Hayakawa
- Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892-1582, USA
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38
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Abstract
Enterococci with resistance to glycopeptides have recently emerged in Australia. We developed multiplex PCR assays for vanA, vanB, vanC1, and vanC2 or vanC3 in order to examine the genetic basis for vancomycin resistance in Australian isolates of vancomycin-resistant Enterococcus faecium and E. faecalis (VRE). The predominant genotype from human clinical E. faecium isolates was vanB. The PCR van genotype was consistent with the resistance phenotype in all but six cases. One vanA E. faecalis isolate had a VanB phenotype, one vanB E. faecium isolate had a VanA phenotype, and four E. faecalis isolates were consistently negative for vanA, vanB, vanC1, and vanC2 or vanC3, even though they exhibited a VanB phenotype. These four isolates were subsequently examined for the presence of vanD by published methods and were found to be negative. No vancomycin-susceptible strains produced a PCR product. On the basis of our findings the epidemiology of VRE in Australia appears to be different from that in either the United States or Europe. Our multiplex PCR assays gave a rapid and accurate method for determining the genotype and confirming the identification of glycopeptide-resistant enterococci. Rapid and accurate methods are essential, because laboratory-based surveillance is critical in programs for the detection, control, and prevention of the transmission of glycopeptide-resistant enterococci.
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Affiliation(s)
- J M Bell
- National Antimicrobial Resistance Surveillance Program, Women's and Children's Hospital, North Adelaide, Australia.
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Bell JM, Tyler RT, Rakow G. Nutritional composition and digestibility by 80-kg to 100-kg pigs of prepress solvent-extracted meals from low glucosinolate Brassica juncea, B. napus and B. rapa seed and of solvent-extracted soybean meal. Can J Anim Sci 1998. [DOI: 10.4141/a97-094] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Seed of Brassica napus canola (cv. AC Excel), B. rapa canola (cv. AC Parkland), and B. juncea canola (line J90-4253) was oil-extracted in a prepress solvent pilot plant. The three canola meals and soybean meal (SBM) (commercial) were fed in four replicates of a digestibility trial to evaluate their digestibility. The meals were mixed with a nutritionally adequate barley-wheat-SBM basal diet at levels of 15 and 30%. Chromic oxide (Cr2O3) was included at 0.5% of the diet as a chemical marker. Eighteen hybrid gilts, approximately 90 kg, were randomized to the first two replicates involving nine diets, including the basal diet, and this allotment was repeated. Brassica juncea meal (air-dry) contained 43.85% crude protein of 82% digestibility and 18.33 MJ kg−1 of gross energy of 71% digestibility. The corresponding values for B. napus AC Excel meal were 41.78, 81, 18.64 and 64; for B. rapa AC Parkland meal 40.05, 79, 18.45 and 71, and for SBM 45.10, 88, 17.28 and 82. Digestible energy values were: B. juncea 13.9, B. napus 13.0, B. rapa 14.1 and SBM 15.9 MJ kg−1. Key words: Canola meal, B. juncea meal, composition, digestibility, pigs
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40
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Abstract
BACKGROUND Skeletal complications are responsible for significant morbidity in Gaucher patients. Plain radiographs have been unreliable in assessing bone marrow infiltration and activity. A way to assess bone marrow improvement is needed during enzyme therapy. OBJECTIVE The purpose of this paper is to assess the usefulness of MR in following improvement of abnormal bone marrow in Gaucher patients on enzyme therapy. MATERIALS AND METHODS Three patients aged 2, 7, and 24 years underwent serial MR scans of the lower extremities before and during treatment with Alglucerase (two patients) and Imiglucerase (one patient). T1-weighted, T2-weighted, STIR and FSE T2-weighted images were utilized. Two patients were imaged after 16 months of therapy, and one patient was imaged after 6 months of therapy. RESULTS All patients had improvement in marrow signal consistent with partial reconversion to fatty marrow during treatment. The findings were more marked after prolonged therapy. T1-weighted images demonstrated findings most clearly. CONCLUSION MR consistently showed improvement in marrow signal in Gaucher patients on enzyme therapy. As smaller doses of enzyme therapy are the trend, MR can be utilized to determine if therapy is effecting a change in the bone marrow.
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Affiliation(s)
- J W Allison
- Department of Radiology, Arkansas Children's Hospital, 800 Marshall Street, Slot 105, Little Rock, AR 72202, USA
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41
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Levac AM, McLean S, Wright LM, Bell JM. A "reader's theater" intervention to managing grief: posttherapy reflections by a family and clinical team. J Marital Fam Ther 1998; 24:81-93. [PMID: 9474525 DOI: 10.1111/j.1752-0606.1998.tb01064.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The sudden and accidental death of a child can be one of the most devastating events in the life of a family. This paper describes one couple's reflections of their grief and mourning following the death of their adolescent son as well as the clinical team's reflections of therapy. The uniqueness of this paper is that it offers a "reader's theater" intervention that enabled further change to occur. The clinical team used a belief model, emphasizing that altering constraining beliefs is at the heart of healing from such tragedies as sudden death (Wright, Watson, & Bell, 1996). This approach is operationalized through therapeutic conversations between family members, clinician, and clinical team. Interventions such as reflecting teams, therapeutic letters, and "homework tasks" were used to modify or challenge constraining beliefs of both the family members and the clinical team members. However, the intent to co-author a paper with this couple provided the serendipity intervention of a "reader's theater" that further served to identify, affirm, and solidify facilitating beliefs.
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Affiliation(s)
- A M Levac
- Children's Hospital of Eastern Ontario, Ottawa.
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42
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Ludvik B, Nolan JJ, Roberts A, Baloga J, Joyce M, Bell JM, Olefsky JM. Evidence for decreased splanchnic glucose uptake after oral glucose administration in non-insulin-dependent diabetes mellitus. J Clin Invest 1997; 100:2354-61. [PMID: 9410915 PMCID: PMC508433 DOI: 10.1172/jci119775] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The role of splanchnic glucose uptake (SGU) after oral glucose administration as a potential factor contributing to postprandial hyperglycemia in non-insulin-dependent diabetes mellitus (NIDDM) has not been established conclusively. Therefore, we investigated SGU in six patients with NIDDM and six weight-matched control subjects by means of the hepatic vein catheterization (HVC) technique. In a second part, we examined the applicability of the recently developed OG-CLAMP technique in NIDDM by comparing SGU and first-pass SGU during HVC with SGU during the OG-CLAMP experiment. The OG-CLAMP method combines a euglycemic, hyperinsulinemic clamp and an oral glucose tolerance test (75 g) during steady state glucose infusion (GINF). During HVC, SGU equals the splanchnic fractional extraction times the total (oral and arterial) glucose load presented to the liver. For OG-CLAMP, SGU was calculated as first-pass SGU by subtracting the integrated decrease in GINF over 180 min from 75 g. Cumulative splanchnic glucose output after oral glucose correlated significantly between both methods and was increased significantly in NIDDM patients (73.1+/-5.1 g for HVC, 76.5+/-5.5 for OG-CLAMP) compared with nondiabetic patients (46.7+/-4.4 g for HVC, 57.5+/-1.9 for OG-CLAMP). Thus, in NIDDM patients, SGU (7.4+/-2.1 vs. 37.8+/-5.9% in nondiabetic patients, P < 0.001) and first-pass SGU (4.7+/-1.7 vs. 26.5+/-5.1% in nondiabetic patients, P < 0.01) were decreased significantly during HVC, as was SGU during OG-CLAMP (3.9+/-1.7 vs. 23.4+/-2.5% in nondiabetic patients, P < 0.0001). SGU measured during OG-CLAMP correlated significantly with SGU (r = 0.87, P < 0.05 for NIDDM patients; r = 0.94, P < 0.01 for nondiabetic patients) and first-pass SGU (r = 0.87, P < 0.05 for NIDDM patients; r = 0.84, P < 0.05 for nondiabetic patients) during HVC. In conclusion, (a) SGU after oral glucose administration is decreased in NIDDM as measured by both methods, and (b) SGU during the OG-CLAMP is well-correlated to SGU and first-pass SGU during HVC in NIDDM. The decrease in SGU in NIDDM might contribute to postprandial hyperglycemia in diabetic subjects.
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Affiliation(s)
- B Ludvik
- Department of Medicine, University of California San Diego and Veterans Administration Hospital, 92161, USA
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43
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Midolo PD, Bell JM, Lambert JR, Turnidge JD, Grayson ML. Antimicrobial resistance testing of Helicobacter pylori: a comparison of Etest and disk diffusion methods. Pathology 1997; 29:411-4. [PMID: 9423225 DOI: 10.1080/00313029700169415] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Routine antimicrobial resistance testing of Helicobacter pylori is more commonly performed since the correlation between metronidazole resistance and failure to eradicate using this drug, has been made. While resistance testing of H. pylori by Etest is simple to perform, it is expensive compared to disk diffusion methods. In this study the Etest was compared with a modified Kirby-Bauer disk diffusion (NCCLS) method for routine resistance screening of H. pylori. Fifty one pre-treatment isolates were tested against amoxycillin, metronidazole, tetracycline and erythromycin by both Etest and disk diffusion using NCCLS guideline strength disks. Clarithromycin was tested by Etest only. Nitroimidazole and macrolide resistance were detected using the modified Kirby-Bauer disk diffusion method which correlated with Etest minimum inhibitory concentration (MIC). Resistance rates were 49% for metronidazole and 8% for clarithromycin. Cross resistance occurs with macrolides against H. pylori and allows testing of erythromycin to predict resistance to clarithromycin. The very low MICs obtained with H. pylori against amoxycillin and tetracycline require the use of Etest or lower strength disk methods to be used.
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Affiliation(s)
- P D Midolo
- Department of Microbiology and Infectious Diseases, Monash Medical Centre, Melbourne, Victoria, Australia
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44
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Chang MC, Arai T, Freed LM, Wakabayashi S, Channing MA, Dunn BB, Der MG, Bell JM, Sasaki T, Herscovitch P, Eckelman WC, Rapoport SI. Brain incorporation of [1-11C]arachidonate in normocapnic and hypercapnic monkeys, measured with positron emission tomography. Brain Res 1997; 755:74-83. [PMID: 9163542 DOI: 10.1016/s0006-8993(97)00088-7] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Positron emission tomography (PET) was used to determine brain incorporation coefficients k* of [1-11C]arachidonate in isoflurane-anesthetized rhesus monkeys, as well as cerebral blood flow (CBF) using [15O]water. Intravenously injected [1-11C]arachidonate disappeared from plasma with a half-life of 1.1 min, whereas brain radioactivity reached a steady-state by 10 min. Mean values of k* were the same whether calculated by a single-time point method at 20 min after injection began, or by least-squares fitting of an equation for total brain radioactivity to data at all time points. k* equalled 1.1-1.2 x 10(-4) ml x s(-1) x g(-1) in gray matter and was unaffected by a 2.6-fold increase in CBF caused by hypercapnia. These results indicate that brain incorporation of [1-11C]arachidonate can be quantified in the primate using PET, and that incorporation is flow-independent.
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Affiliation(s)
- M C Chang
- Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
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Appel NM, Rapoport SI, O'Callaghan JP, Bell JM, Freed LM. Sequelae of parenteral domoic acid administration in rats: comparison of effects on different metabolic markers in brain. Brain Res 1997; 754:55-64. [PMID: 9134959 DOI: 10.1016/s0006-8993(97)00042-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Parenterally administered domoic acid, a structural analog of the excitatory amino acids glutamic acid and kainic acid, has specific effects on brain histology in rats, as measured using different anatomic markers. Domoic acid-induced convulsions affects limbic structures such as hippocampus and entorhinal cortex, and different anatomic markers can detect these neurotoxic effects to varying degrees. Here we report effects of domoic acid administration on quantitative indicators of brain metabolism and gliosis. Domoic acid, 2.25 mg/kg i.p., caused stereotyped behavior and convulsions in approximately 60% of rats which received it. Six to eight days after domoic acid or vehicle administration, the animals were processed to measure regional brain incorporation of the long-chain fatty acids [1-(14)C]arachidonic acid ([14C]AA) and [9,10-(3)H]palmitic acid ([3H]PA), or regional cerebral glucose utilization (rCMRglc) using 2-[1-(14)C]deoxy-D-glucose, by quantitative autoradiography. Others rats were processed to measure brain glial fibrillary acidic protein (GFAP) by enzyme-linked immunosorbent assay. Domoic acid increased GFAP in the anterior portion of cerebral cortex, the caudate putamen and thalamus compared with vehicle. However, in rats that convulsed after domoic acid GFAP was significantly increased throughout the cerebral cortex, as well as in the hippocampus, septum, caudate putamen, and thalamus. Domoic acid, in the absence of convulsions, decreased relative [14C]AA incorporation in the claustrum and pyramidal cell layer of the hippocampus compared with vehicle-injected controls. In the presence of convulsions, relative [14C]AA incorporation was decreased in hippocampus regions CA1 and CA2. Uptake of [3H]PA into brain was unaffected. Relative rCMRglc decreased in entorhinal cortex following domoic acid administration with or without convulsions. These results suggest that acute domoic acid exposure affects discrete brain circuits by inducing convulsions, and that domoic acid-induced convulsions cause chronic effects on brain function that are reflected in altered fatty acid metabolism and gliosis.
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Affiliation(s)
- N M Appel
- Division of Applied Pharmacology Research, Center for Drug Evaluation and Research, Food and Drug Administration, Laurel, MD 20708-2476, USA.
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Chang MC, Grange E, Rabin O, Bell JM. Incorporation of [U-14C]palmitate into rat brain: effect of an inhibitor of beta-oxidation. J Lipid Res 1997; 38:295-300. [PMID: 9162749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We examined the effect of a clinically therapeutic dose of methyl 2-tetradecylglycidate (McN-3716, methyl palmoxirate, MEP) (2.5 mg/kg), an inhibitor of beta-oxidation of fatty acids, on incorporation of radiolabeled palmitic acid ([U-14C]PAM) from plasma into brain lipids of awake rats. Four hour pretreatment with 2.5 mg/kg MEP significantly increased the incorporation of [U-14C]PAM into brain lipids and substantially decreased aqueous radiolabeled metabolites in brain that can constitute unwanted background signal when analyzed by quantitative autoradiography. MEP treatment increased the lipid to aqueous background radioactivity from 0.8 to 3.0. Net rate of incorporation, k*, was significantly increased (60%) by MEP and was attributed to incorporation of [U-14C]PAM into phospholipid and triglyceride brain compartments. MEP treatment did not affect the size of the fatty acyl-CoA pool or the distribution of the various molecular acyl-CoA species. These results indicate that MEP, at a dose of 2.5 mg/kg (per os), can be used to increase incorporation of [1-(11C)]PAM for studying brain lipid metabolism in humans by positron emission tomography (PET).
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Affiliation(s)
- M C Chang
- Laboratory of Neurosciences, National Institutes on Aging, National Institutes of Health, Bethesda, MD 20892, USA
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Wright LM, Bell JM. The evolution of a clinical practice approach. AARN News Lett 1997; 53:11-2. [PMID: 9043238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- L M Wright
- Faculty of Nursing, University of Calgary
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49
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Abstract
In vivo rates of incorporation and turnover of palmitate and arachidonate in brain phospholipids were measured in awake rats treated chronically with lithium, following intravenous infusion of radiolabeled palmitate and arachidonate, respectively. Chronic lithium, at a brain level considered to be therapeutic in humans, decreased turnover of arachidonate within brain phosphatidylinositol, phosphatidylcholine and phosphatidylethanolamine by up to 80% (P < 0.001). In contrast, lithium had a minimal effect on turnover of palmitate, causing only a 26% reduction in turnover in phosphatidylcholine (P < 0.01). These results suggest that a major therapeutic effect of lithium is to reduce turnover specifically of arachidonate, possibly by inhibiting phospholipase A2 involved in signal transduction. The effect may be secondary to the known action of lithium on the phosphoinositide cycle, by inhibiting the activity of inositol monophosphatase.
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Affiliation(s)
- M C Chang
- Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892-1582, USA.
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Bell JM, Rakow G. Trypsin inhibitors and phytic acid in oil-extracted meals from seeds of several Brassica species and of Sinapis alba. Can J Anim Sci 1996. [DOI: 10.4141/cjas96-061] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A total of 124 seed samples representing strains and cultivars of Brassica napus, B. rapa, B. juncea, B. carinata, and Sinapis alba were selected for assays of trypsin inhibitor (TI) and phytic acid (PA). On an oil-extracted basis the TI values ranged from 1.26 to 5.31 units g−1. Values for B. napus ranked highest (3.58, 3.61) and B. juncea lowest (1.26, 1.39, 1.56) (P < 0.05). In a comparison of PA in three cultivars (B. napus, B. rapa, B. juncea), the cultivars differed in PA contents (2.52, 2.94, 2,70, respectively), there were no year-to-year differences over 4 yr (2.56, 2.67 2.68 vs. 2.96) but there were significant location effects (2.12, 2.21 vs. 3.04, 3.42). In a set of 10 cultivars replicated themes, B. juncea PA contents (3.35–3.91) exceeded those of B. napus (2.92, 3.06), and B. carinata (2.72, 3.15) Sinapis alba had the lowest value (2.49). Bronowski (B. napus), the gene source of all low glucosinolate cultivars, contained the most TI (5.31 units g−1) and the least PA (1.93%). Key words: Phytic acid, trypsin inhibitor, Brassica, Brassica napus, Brassica rapa, Brassica juncea, Brassica carinata, Sinapis alba
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