Demonstration by flow cytometry that CD5+CD8+ cells carry alcelaphine herpesvirus 1 in inoculated rabbits developing malignant catarrhal fever

Poster (2005, November 18)

Alcelaphine herpesvirus 1 (AlHV 1), carried by wildebeest (Connochaetes taurinus) asymptomatically, causes malignant catarrhal fever (MCF) when cross species transmitted to a variety of susceptible ... [more ▼]

Alcelaphine herpesvirus 1 (AlHV 1), carried by wildebeest (Connochaetes taurinus) asymptomatically, causes malignant catarrhal fever (MCF) when cross species transmitted to a variety of susceptible species of the Artiodactyla order. MCF is a fascinating disease described as a combination of lymphoproliferative and degenerative lesions. The study of MCF pathogenesis has been impeded by an inability to produce recombinant virus, due mainly to the fact that AlHV 1 becomes attenuated during passage in culture. Here, we have overcome these difficulties by (i) cloning the entire AlHV 1 genome as a stable, infectious and pathogenic bacterial artificial chromosome (BAC), and (ii) by using prokaryotic recombination technology for the production of an AlHV 1 recombinant. Firstly, the AlHV 1 genome was BAC cloned using one insertion site in a region containing no open reading frame. This insertion allowed the production of an AlHV 1 BAC clone stably maintained in bacteria and able to regenerate virions when transfected into permissive cells. BAC derived AlHV 1 virions induced MCF in rabbits comparably to the AlHV 1 wild type (WT) strain. Secondly, a two step mutagenesis procedure in E. coli was used to generate a recombinant strain expressing enhanced-green fluorescent protein (EGFP) as a reporter gene. After reconstitution of recombinant virions into permissive cells and excision of the BAC cassette, flow cytometry analyses were performed to validate the recombinant strain and to investigate the pathogenesis of MCF. The results of these analyses can be summarized as follows: (i) the validity of the EGFP expression cassette as a reporter gene has been demonstrated by in vitro infections; (ii) inoculation of rabbits revealed that the recombinant strain has retained the pathogenicity of its parental strain and that the cell types carrying AlHV-1 in peripheral blood mononuclear cells, lymph nodes and the spleen are mainly CD5+ CD8+ cells. [less ▲]

Territoires et développement durable

Conference (2005, November 18)

Maîtrise par la méthode HACCP: exemples pratiques

Conference given outside the academic context (2005)

Prevention of perinatal group B streptococcak diseases: update and guidelines

in Ducoffre, Geneviève (Ed.) Program and Abstracts book of 2005 Symposium of ISP (2005, November 17)

Face à l’importance et à la gravité des infections périnatales à streptocoques du groupe B (GBS), depuis dix ans, différentes approches préventives ont été proposées. Le point commun est l’administration ... [more ▼]

Face à l’importance et à la gravité des infections périnatales à streptocoques du groupe B (GBS), depuis dix ans, différentes approches préventives ont été proposées. Le point commun est l’administration intraveineuse d’antibiotiques pendant le travail et l’accouchement aux patientes identifiées « à risque » soit par un dépistage de colonisation maternelle pendant la grossesse, soit par la présence de facteurs de risque définis. En 2002, après quelques années d’implémentation et d’adoption des recommandations éditées par le CDC (Centers for Diseases Control and Prevention, Atlanta, USA) en 1996, différentes études ont évalué l’efficacité des alternatives et ont démontré pour différentes raisons, la supériorité du dépistage pendant la grossesse pour l’identification des mères « à risque ». C’est pourquoi, en août 2002, le CDC publiait une version révisée des recommandations en proposant un dépistage universel, c'est-àdire de TOUTES les femmes enceintes. Parallèlement d’autres pays, notamment la France et la Belgique, évaluaient aussi l’efficacité et la faisabilité de différentes stratégies plus ou moins proches de celles du CDC. Depuis juillet 2003, les recommandations belges « Prevention of Perinatal Group B streptococcal Infections. Guidelines from the Belgium Health Council . (SHC. 721) » sont disponibles sur le site du CSH : (http://www.health.fgov.be/CSH_HGR/Francais/Brochures/GBS_2003.pdf et http://www.health.fgov.be/CSH_HGR/Nederlands/Brochures/GBS_2003.pdf). Ces recommandations sont très proches de celles du CDC moyennant quelques adaptations techniques et de prises en charge des nouveau-nés et, qui devraient en améliorer l’efficacité. Ces recommandations belges seront présentées et discutées. L’efficacité optimale attendue de ces recommandations est une réduction de 75% des cas d’infection néonatale précoce confirmés par culture. Pour atteindre cet objectif, la communication et une coordination multidisciplinaires sont indispensables entre le service de gynécologie-obstétrique, le laboratoire, le bloc d’accouchement et le service de néonatologie. [less ▲]

Study of neuronal preconditionning by ESR

Scientific conference (2005, November 17)

Cassini UVIS observations of Jupiter's auroral variability

in Icarus: International Journal of Solar System Studies (2005), 178(2), 312-326

The Cassini spacecraft Ultraviolet Imaging Spectrograph (UVIS) obtained observations of Jupiter's auroral emissions in H-2 band systems and H Lyman-alpha from day 275 of 2000 (October 1), to day 81 of ... [more ▼]

The Cassini spacecraft Ultraviolet Imaging Spectrograph (UVIS) obtained observations of Jupiter's auroral emissions in H-2 band systems and H Lyman-alpha from day 275 of 2000 (October 1), to day 81 of 2001 (March 22). Much of the globally integrated auroral variability measured with UVIS can be explained simply in terms of the rotation of Jupiter's main auroral arcs with the planet. These arcs were also imaged by the Space Telescope Imaging Spectrograph (STIS) on Hubble Space Telescope (HST). However, several brightening events were seen by UVIS in which the global auroral output increased by a factor of 2-4. These events persisted over a number of hours and in one case can clearly be tied to a large solar coronal mass ejection event. The auroral UV emissions from these bursts also correspond to hectometric radio emission (0.5-16 MHz) increases reported by the Galileo Plasma Wave Spectrometer (PWS) and Cassim Radio and Plasma Wave Spectrometer (RPWS) experiments. In general, the hectometric radio data vary differently with longitude than the UV data because of radio wave beaming effects. The 2 largest events in the UVIS data were on 2000 day 280 (October 6) and on 2000 days 325-326 (November 20-21). The global brightening events on November 20-21 are compared with corresponding data on the interplanetary magnetic field, solar wind conditions, and energetic particle environment. ACE (Advanced Composition Explorer) solar wind data was numerically propagated from the Earth to Jupiter with an MHD code and compared to the observed event. A second class of brief auroral brightening events seen in HST (and probably UVIS) data that last for similar to 2 min is associated with aurora] flares inside the main auroral ovals. On January 8, 2001, from 18:45-19:35 UT UVIS H-2 band emissions from the north polar region varied quasiperiodically. The varying emissions, probably due to amoral flares inside the main auroral oval, are correlated with low-frequency quasiperiodic radio bursts in the 0.6-5 kHz Galileo PWS data. (c) 2005 Elsevier Inc. All rights reserved. [less ▲]

Synthesis of poly(vinyl acetate) and poly(vinyl alcohol) containing block copolymers by combination of cobalt-mediated radical polymerization and ATRP

in Macromolecules (2005), 38(23), 9488-9496

Poly(vinyl acetate) (PVAc) chains of a low polydispersity (Mw/Mn similar to 1.1-1.2) have been prepared by cobalt-mediated radical polymerization of vinyl acetate (VAc). They have been end-capped by an ... [more ▼]

Poly(vinyl acetate) (PVAc) chains of a low polydispersity (Mw/Mn similar to 1.1-1.2) have been prepared by cobalt-mediated radical polymerization of vinyl acetate (VAc). They have been end-capped by an activated bromide by addition of an alpha-bromoester or an alpha-bromoketone containing nitroxide and converted into effective macroinitiators for the atom transfer radical polymerization of styrene (Sty), ethyl acrylate, and methyl methacrylate. Because each block is formed by a controlled process, well-defined PVAc containing diblock copolymers are easily prepared. The PVAc-b-PS copolymers synthesized from alpha-bromoketone end-capped PVAc can be converted into well-defined poly(vinyl alcohol)-b-polystyrene amphiphiles by methanolysis of the poly(vinyl acetate) block. Self-association of an amphiphilic poly(vinyl alcohol)(3500)-b-polystyrene(16 600) in a (4/1) water/tetrahydrofuran mixture results in the formation of vesicles as observed by transmission electron microscopy. [less ▲]

Iodide organification disorder in autonomous thyroid nodule.

Poster (2005, November 15)

Association behavior of thermo-responsive block copolymers based on poly(vinyl ethers)

in Polymer (2005), 46(23), 9899-9907

Thermo-sensitive nanosized structures have been prepared in water from poly(methyl vinyl ether)-block-poly(isobutyl vinyl ether) (PMVE-b-PIBVE) block copolymers. The composition and the architecture ... [more ▼]

Thermo-sensitive nanosized structures have been prepared in water from poly(methyl vinyl ether)-block-poly(isobutyl vinyl ether) (PMVE-b-PIBVE) block copolymers. The composition and the architecture (diblock and triblock architectures) of the PMVE-b-PIBVE copolymers have been varied. The investigated copolymers had an asymmetric composition with a major PMVE block, While the PIBVE blocks are hydrophobic, the PMVE blocks are hydrophilic at room temperature and become hydrophobic above their demixing temperature (around 36 degrees C) as a result of the lower critical solution temperature (LCST) behavior. At room temperature, the amphiphilic copolymers aggregate in water above a critical micelle concentration, which has been experimentally measured by hydrophobic dye solubilization. The hydrodynamic diameter of the structures formed above the cmc has been measured by dynamic light scattering (DLS) while their morphology has been studied by transmission electron microscopy (TEM). H-1 NMR measurements in D2O at room temperature reveal that the aggregates contain PIBVE insoluble regions surrounded by solvated PMVE chains. These investigations have shown that polydisperse spherical micelles are formed for asymmetric PMVE-b-PIBVE copolymers containing at least 9 IBVE units. For copolymers containing less IBVE units, loose aggregates are formed. Finally, the thermo-responsive, reversible properties of these structures have been investigated. Above the cloud point of the copolymers, the loose aggregates precipitate while the micelles form large spherical structures. [less ▲]

Structural objects: formal definitions and constructive requirements in Hilbert, Husserl and Carnap

Conference (2005, November 14)