Vice-Chancellor and Principal, Professor Adam Habib, will leave Wits University at the end of December 2020. No abstract available. Il appartient au groupe 13 du tableau périodique ainsi qu'à la famille des métaux pauvres.. SLUth Search Plus. To block actin-dependent phagocytosis, cytochalasin D (10 μg/ml) (Sigma) was added to PMNs 30 min prior to infection and kept in the infection medium for the duration of the experiment. Julie Boyer. Opa expression also facilitates Gc transcytosis of polarized epithelial monolayers, allowing the bacteria to gain access to subepithelial regions (64). 2C and F), and the opaque subpopulation expressed Opa proteins by Western blotting (Fig. The presence of Gc at human mucosal surfaces initiates the recruitment of abundant polymorphonuclear leukocytes (neutrophils; PMNs) to the site of infection (4). To examine the survival of genetically opa-deficient Gc after PMN challenge, adherent, IL-8-primed human PMNs were infected with ΔopaBEGK and Opaless Gc. Gc growth measurements. No differences in growth were noted between OpaD+nv and OpaD+var Gc, whether cultured on solid or in liquid medium (see Fig. Statistics.Differences between Gc strains were compared using two-tailed Student's t test. 3C. Common Chemistry is helpful to non-chemists who know either a name or CAS Registry Number ® of a common chemical and want to pair both pieces of information. Total protein expression was similar between the two strains (see Fig. CFU/ml were enumerated from the culture before and after serum exposure, and bacterial survival was expressed as (CFU/ml)t = 30 min/(CFU/ml)t = 0 min × 100%. To begin to understand the mechanism underlying the increased killing of OpaD+ Gc by PMNs, we measured bacterial survival after exposure to the model cationic peptide polymyxin B. WeBoost - Agence Web. The Neisseria gonorrhoeae (the gonococcus [Gc]) opacity-associated (Opa) proteins mediate bacterial binding and internalization by human epithelial cells and neutrophils (polymorphonuclear leukocytes [PMNs]). 99. Prior to this work, a derivative of FA1090 in which all 11 opa genes had been deleted, the ΔopaA-K mutant, was constructed (50, 53). My Cloud Web access. Pädagogische Hochschulbibliothek Ludwigsburg. *, P < 0.025 (Student's two-tailed t test) for Opaless Gc ± cytochalasin D. Complementation of Opaless Gc with non-phase-variable OpaD restores Opa-dependent phenotypes in Gc.Opaless Gc was complemented with a constitutively expressed allele of the FA1090 opaD gene. Gc does not require Opa expression for nonopsonic internalization by primary human PMNs.Several groups have shown that PMN phagocytosis of unopsonized Gc requires bacterial expression of OpaCEA proteins (28–32). Rebond de l'épidémie de Covid-19 : le maire de Reims "propose de reconfiner" après Noël et jusqu'à... 22/12/2020 08:26:33. These results show that Opaless Gc behaves akin to phenotypically Opa− bacteria after challenge with human PMNs. Username. This question is for testing whether or not you are a human visitor and to prevent automated spam submissions. De plus, vous pouvez compter sur nous pour toujours utiliser des matériaux et une impression de la plus haute qualité. Parental and ΔopaBEGK Gc induced minor amounts of ROS production from PMNs, but the oxidative burst was smaller and delayed compared to PMNs infected with S. aureus (Fig. 5A). Study Habits and Academic Performance in English Plus of Freshmen Maritime Students of LB By: Dr. Precy Guerra (2007) Show Abstract . S1B in the supplemental material), and OpaD+nv Gc retained the LOS profile of Opaless Gc (see Fig. Screening and validation of opa gene deletions in FA1090 Gc.Deletion constructs were sequentially introduced into FA1090 Gc by natural transformation on a solid medium (43). S2B) and CFU/ml of culture (see Fig. Occurrence of color/opacity colonial variants in clinical cultures, Opa binding to cellular CD66 receptors mediates the transcellular traversal of, Neisserial binding to CEACAM1 arrests the activation and proliferation of CD4+ T lymphocytes, Submission, Review, & Publication Processes,, Constitutively Opa-Expressing and Opa-Deficient Neisseria gonorrhoeae Strains Differentially Stimulate and Survive Exposure to Human Neutrophils. (ii) Liquid medium.Gc was grown in GCBL modified with Kellogg's supplements I and II and 0.042% sodium bicarbonate as previously described (33). Among these isolates was variable OpaD+ Gc (OpaD+var). $9.99 $ 9. My Cloud Web access. The use of these derivatives provides a robust and flexible system for quantifying the effect of Opa proteins on bacteria-bacteria and bacteria-host interactions. PMN oxidative burst.Reactive oxygen species generation from PMNs exposed to Gc was measured by luminol-dependent chemiluminescence, using a Victor 3 multilabel plate reader (Perkin-Elmer), as described in reference 33. The mutated sequence's codons appear at the same frequency in the Gc genome as the parental, phase-variable codons ( décès, hospitalisations, réanimations, guérisons par département English plus : (instructional module) , 1210L-1700L Publication: Manila Rex Book Store, 2010 . The deletions were designed to replace most of the opa open reading frame (ORF) with an HpaI restriction site (underlined in the primer sequence in Table S2 in the supplemental material). FA1090 opa gene deletion construction.The locations and characteristics of all opa genes in FA1090 Gc are listed in Table S1 in the supplemental material. Get it as soon as Thu, Nov 19. Opa expression was validated by Western blotting with the 4B12 pan-Opa antibody (see below). Liquid - 50 oz (3.12 lb) - Free & Clear Scent - 1 / Each - Clear. Moreover, during extended growth in liquid culture, bacteria of a different Opa expression state stochastically emerge (our unpublished observations). When investigating the contribution of Opa proteins to Gc interactions with PMNs and other cells, the high rate of Opa phase variation means that any Gc culture in which one Opa phenotype predominates will always include bacteria of a different Opa expression state. All Content in this webport is for the using stakeholder of VTU Only. L'aluminium est l'élément chimique de numéro atomique 13, de symbole Al. NLB promotes reading, learning and information literacy by providing a trusted, accessible and globally-connected library and information service through the National Library and a comprehensive network of Public Libraries. P S. This adult dry food is great for your senior cat. Its powerful stain-blocking formula also blocks most pet and smoke odors and creates an … Scale bar = 1 mm. PCR analysis showed the four intended opa genes and no others were deleted in ΔopaBEGK Gc, while all 11 opa genes were deleted in Opaless Gc (Fig. These results confirm that OpaD is a strong stimulator of PMN ROS production. This work was supported by NIH R00 TW008042 and R01 AI097312-01A1, Jeffress Memorial Trust Award J-1017, University of Virginia Research & Development Committee Seed Award, University of Virginia nanoSTAR Seed Award, and University of Virginia Fund for Excellence in Science and Technology Award (to A.K.C.). We circumvented this issue by creating Opaless Gc in which all opa genes were deleted from the chromosome of strain FA1090 bacteria and complementing it with a nonvariable opaD allele. . Opaless Gc survived exposure to primary human PMNs and suppressed the PMN oxidative burst akin to parental, Opa− bacteria. --HappyCamper 1 July 2005 02:55 (UTC) To me it looks kinda like a sycamore. Copyright © 2013, American Society for Microbiology. We took advantage of the redundancy of the genetic code to engineer an OpaD allele in which the CTCTT repeat tract was replaced with a DNA sequence that encoded the same amino acids but cannot phase vary (Fig. 1B). Finally, the contribution of putative (non-Opa) Gc virulence factors can be investigated in constitutively Opa+ or Opa− genetic backgrounds, to determine if and how the presence of Opa affects their function. Gels were silver stained using the Pierce silver stain kit (Fisher) according to the manufacturer's protocols or transferred to polyvinylidene difluoride (PVDF) and immunoblotted with the 3F11 monoclonal antibody, obtained from Michael Apicella (University of Iowa), followed by horseradish peroxidase-coupled goat anti-mouse IgM antibody (Southern Biotech). Your session has expired. Dr. Ph. The parent of Opaless and OpaD+ nonvariable (OpaD+nv) Gc has a point mutation in the G-quadruplex region upstream of pilE that abrogates pilin antigenic variation (40) (FA1090 1-81-S2 P+nv), to ensure all bacteria express the same pilin. Journal of Microbiology & Biology Education, Microbiology and Molecular Biology Reviews. Hope you guys can identify them as in the past. The University of Technology Sydney Library provides support for the teaching, learning and research needs of the students and staff at UTS. Thus, FA1090 Opaless Gc and nonvarying Opa derivatives can be used in place of predominantly Opa+ and Opa− bacteria to avoid the confounding effects of Opa variation during infection. Vous avez besoin d'aide ? One such pressure may come from the requirement for Gc to attach to the apical surface of the mucosal epithelium and be internalized by epithelial cells (63). Opac Recherchieren, Kontoeinsicht, Vormerken, Verlängern In unserem Online-Katalog suchen Sie nach gedruckten Büchern, E-Books, Zeitschriften und audiovisuellen Medien. • OPAC search facility for Print and E-books of different publishers with links to full texts • Liaisonrogram P with Departments (LPD) to conduct Orientation/User Education Programme at each departments • Research/Project Support Services (RPS) to users • Knowledge Sharing Session for all … This UPC 18" 5mm heavy wall straight tube water pipe is a practical piece. . Cell wall protein differences among color/opacity colony variants of, Characterization of the repertoire of hypervariable regions in the protein II (, Crystal structure of neisserial surface protein A (NspA), a conserved outer membrane protein with vaccine potential, Mapping the binding domains on meningococcal Opa proteins for CEACAM1 and CEA receptors, Sequence diversity, predicted two-dimensional protein structure, and epitope mapping of, Opa proteins and CEACAMs: pathways of immune engagement for pathogenic, Binding of syndecan-like cell surface proteoglycan receptors is required for, Gonococcal opacity: lectin-like interactions between Opa proteins and lipooligosaccharide, Construction and characterization of a derivative of, Phase variation of gonococcal protein II: regulation of gene expression by slipped-strand mispairing of a repetitive DNA sequence, Multiple gonococcal opacity proteins are expressed during experimental urethral infection in the male, Expression of outer membrane protein II by gonococci in experimental gonorrhea, Oxidative killing of microbes by neutrophils, The effect of protein II and pili on the interaction of, Gonococci possessing only certain P.II outer membrane proteins interact with human neutrophils, Variable opacity (Opa) outer membrane proteins account for the cell tropisms displayed by, Studies on gonococcus infection. (i) CFU/colony.The CFU arising per colony of FA1090 Gc with and without opa deletions was enumerated as previously described (46). 1A). Gc was maintained on Gc medium base (BD Difco) plus Kellogg's supplements I and II (41) (GCB) and routinely grown for 16 to 20 h at 37°C in 5% CO2. (A) ROS production was measured in human PMNs exposed to S. aureus, ΔopaBEGK Gc (Opa− Gc), or ΔopaBEGK Gc phase-ON for OpaA, OpaD, OpaF, or OpaI, as described for Fig. We thank Joanna Goldberg for critical reading of the manuscript. Loss of opa is indicated by the faster-migrating PCR product for each primer set. Création de site internet, Référencement Google, Publicité sur les réseaux sociaux. Opaless Gc and an intermediate isolate in which the genes encoding translucent Opa proteins were deleted (ΔopaBEGK) behaved similarly to Opa phase-OFF bacteria in in vitro growth and survival after exposure to primary human PMNs. All Rights Reserved. TPL is one of the world's busiest urban public library systems, with 100 branches across the city and over 10 million books, movies, and other items to borrow or download online. Search. (A) PMNs were left untreated or exposed to opsonized S. aureus, phenotypically translucent parental Gc (parent), ΔopaBEGK Gc, or Opaless Gc. Please login again. TOP10 E. coli (Invitrogen) was grown in Luria-Bertani (LB) (BD Difco) broth or agar supplemented with 50 μg/ml kanamycin (Sigma-Aldrich) at 37°C for plasmid propagation. We previously showed that OpaB+ Gc survives less well than Opa− bacteria after PMN exposure (35). All deletion products were verified by DNA sequencing prior to transformation into Gc. Serveur de podcast de l'Inalco :. 2E to G). OpaD+nv and OpaD+var Gc expressed similar amounts of Opa protein (Fig. Montreuil. Experiments were performed 3 times. Expression of Opa proteins, particularly OpaCEA, affects PMN antibacterial activities and Gc survival after exposure to PMNs (4). While Opa variation may enable bacterial evasion of host immunity and adaptation to new hosts or sites within a host, it complicates the assessment of how Opa expression influences specific aspects of Gc pathogenesis. Gc-PMN coculture.All human subject research was conducted in accordance with a protocol approved by the University of Virginia Institutional Review Board for Health Sciences Research. Thus, Gc can express anywhere from zero to theoretically all Opa proteins. Study Habits and Academic Performance in English Plus of Freshmen Maritime Students of LB By: Dr. Precy Guerra (2007) Show Abstract Status and Prospect for the Sustainable Development of the Maritime Education Program of LB By: Dr. Rolando Lontoc Sr. (2007) Show Abstract. 181 p. 22 cm Date: 2010 Availability: Copies available: College Library Filipiniana Section [ PE1130 .B928 2010 ] (3), DIRECT - Coronavirus : les professeurs Raoult et Perronne visés par une plainte de l’ordre des médecins 22/12/2020 08:39:00. Murièle Jacquier, Ph.D. Murièle Jacquier, Ph.D Chargée d’enseignement en didactique de la physique chez Université de Genève Auvergne-Rhône-Alpes, France. We therefore created a derivative of strain FA1090 Gc carrying in-frame deletions in all opa genes, which is termed Opaless. Sensitivity of OpaD+ Gc to killing by human PMNs but not polymyxin B. Interactions between Gc and human cells are modulated by a variety of bacterial surface structures, including type IV pili, lipooligosaccharide (LOS), porin, and opacity-associated (Opa) proteins (5). Contactez-nous au ou par email en cliquant ici. All Content in this webport is for the using stakeholder of VTU Only. Gefällt 1.295 Mal. The first four opa genes deleted encoded the translucent Opa proteins OpaB, E, G, and K to yield FA1090 ΔopaBEGK Gc. XIV. However, the FA1090 ΔopaA-K mutant has a significant growth defect on solid and in liquid media (53) (our unpublished observations). Absence of Opa protein expression in Opaless Gc. Investigating the contribution of Opa proteins to gonococcal pathogenesis is complicated by high-frequency phase variation of the opa genes. Scale bar = 10 μm. Expression of one or more Opa proteins in parental and ΔopaBEGK opaque Gc is indicated by a heat-modifiable shift in reactivity with the Opa antibody. A third possibility is that Opa+ bacteria are more sensitive to PMN antimicrobial proteins. Using these derivatives, we made several conclusions about the contribution of Opa protein expression to Gc biology and pathogenesis. The latest wellness and longevity research. For instance, complementation of Opaless with non-phase-varying opa alleles, for example, OpaD+nv, will address how individual Opa proteins contribute to different models of infection. Phenotypically translucent ΔopaBEGK Gc did not express any Opa proteins by Western blotting (Fig. 2B to G) and yielded equivalent numbers of CFU per colony after 24 h of growth on solid medium (see Fig. Bacterial survival was calculated as the CFU after 45 min of exposure, divided by the input CFU. All Rights Reserved. De Gruyter publishes first-class scholarship and has done so for more than 270 years. Gc varies its Opa proteins and other surface components during human infection (5). PMNs' antigonococcal activity is due primarily to nonoxidative species such as cationic antimicrobial peptides (35, 54–56). The translucent Opa proteins confer a poorly opaque phenotype on Gc colonies grown on commonly used media, and Opa expression can be reliably detected only by immunoblot (38). Therefore, we assessed the ability of adherent, primed PMNs to internalize genetically Opa-deficient Gc by immunofluorescence. Therefore, the ability to phase vary Opa protein expression allows Gc to fine-tune its interactions with epithelial and immune cells as needed during the course of infection. Die Verfügbarkeit der einzelnen Titel wird in der Trefferliste angezeigt. Interestingly, there was a small increase in ROS production from PMNs exposed to cultures of predominantly translucent parental and ΔopaBEGK Gc, whereas Opaless Gc stimulated no detectable ROS from PMNs. The opaD+nv amplicon was generated by overlap extension PCR using the primers in Table S2 and conditions in Table S3 in the supplemental material and then transformed into Opaless Gc. Scale bar = 1 mm. Opa expression is phase variable due to slipped-strand mispairing at pentameric repeats in the 5′ end of opa genes (20, 21). Opaless, ΔopaBEGK, and parental Opa phase-OFF Gc were statistically indistinguishable from PMNs in their survival profile, and all survived significantly better than OpaB+ bacteria (Fig. We gratefully acknowledge members of the Criss laboratory for their input, especially Jonathan Handing for advice on polymyxin B. Opac der PH Bibliothek Ludwigsburg Verlängern, vormerken, verwalten, … Der Opac enthält den Bestand der Hochschulbibliothek (Bücher, Zeitschriften, DVDs, E-Books). Nutzen Sie die Erweiterte Suche zur präzisen Recherche.Die Magazinräume sind für unsere KundInnen nicht zugänglich, die Medien sind aber bestellbar. Luminescence was measured in 1-s intervals every 5 min for 30 to 60 min. Entrons en contact. However, OpaD+ Gc showed no increased sensitivity to polymyxin B, a surrogate for the cationic antimicrobial peptides produced by PMNs. S1C and D). One of the main reasons for creating Opaless Gc was to avoid changes in expression of Opa proteins during bacterial culture that adversely affect Gc-host interaction studies. Gc genomes contain approximately 11 opa loci, encoding 7 to 9 unique Opa proteins (7–9). Opaless Gc can serve as a recipient for Opa variants expressed by other strains of Neisseria or Opa proteins synthesized in vitro, in order to evaluate these proteins' receptor binding profiles and other biochemical properties. 6C). After dilution to an optical density at 550 nm (OD550) of 0.07, optical densities were measured, and CFU/ml were enumerated from each culture every hour for 3 h. Growth curves were not extended past 3 h since Gc begins to undergo autolysis as it approaches the stationary phase. To assess how expression of OpaD influenced FA1090 Gc survival after challenge with PMNs, adherent, primed human PMNs were exposed to Opaless, OpaD+var, and OpaD+nv Gc. LOS preparation and Western blotting.LOS was prepared from Gc as described by Davis and Goldberg (45), except Gc was collected after overnight growth on GCB, and the protocol was stopped after the proteinase K treatment. Mol Cell Biol. FA1090 has been used extensively in human urethral challenge studies (57) and the murine genital tract model of gonorrhea (58). opa genes were deleted in the following order: E, B, K, G, C, I, A, D, F, H, and J. FREE Shipping . It is a branch library that services to students enrolled on various programs such as BSCS, BSIT, BSIS, BSBA, BSENT& BSA, that extends to faculty members, non-teaching staffs and administrators of Mapúa-Makati. Using Opaless and OpaD+nv Gc, we found that constitutively Opa− and Opa+ Gc behave similarly to their phase-varying counterparts in survival after challenge with primary human PMNs and in modulating the PMN oxidative burst.