1,720,996 research outputs found
Immunization with recombinant truncated Neisseria meningitidis-Macrophage Infectivity Potentiator (rT-Nm-MIP) protein induces murine antibodies that are cross-reactive and bactericidal for Neisseria gonorrhoeae
No full textNeisseria meningitidis (Nm) and N. gonorrhoeae (Ng) express a Macrophage Infectivity Potentiator (MIP, NMB1567/NEIS1487) protein in their outer membrane (OM). In this study, we prepared independent batches of liposomes (n = 3) and liposomes + MonoPhosphoryl Lipid A (MPLA) (n = 3) containing recombinant truncated Nm-MIP protein encoded by Allele 2 (rT-Nm-MIP, amino acids 22–142), and used these to immunize mice. We tested the hypothesis that independent vaccine batches showed similar antigenicity, and that antisera could recognise both meningococcal and gonococcal MIP and induce cross-species bactericidal activity.
The different batches of M2 rT-Nm-MIP-liposomes ± MPLA showed no significant (P > 0.05) batch-to-batch variation in antigenicity. Anti-rT-Nm-MIP sera reacted equally and specifically with Nm-MIP and Ng-MIP in OM and on live bacterial cell surfaces. Specificity was shown by no antiserum reactivity with Δmip bacteria. Using human complement/serum bactericidal assays, anti-M2 rT-Nm-MIP sera killed homologous meningococcal serogroup B (MenB) strains (median titres of 32–64 for anti-rT-Nm-MIP-liposome sera; 128–256 for anti-rT-Nm-MIP-liposome + MPLA sera) and heterologous M1 protein-expressing MenB strains (titres of 64 for anti rT-Nm-MIP-liposome sera; 128–256 for anti-rT-Nm-MIP-liposome + MPLA sera). Low-level killing (P < 0.05) was observed for a MenB isolate expressing M7 protein (titres 4–8), but MenB strains expressing M6 protein were not killed (titre < 4–8). Killing (P < 0.05) was observed against MenC and MenW bacteria expressing homologous M2 protein (titres of 8–16) but not against MenA or MenY bacteria (titres < 4–8).
Antisera to M2 rT-Nm-MIP showed significant (P < 0.05) cross-bactericidal activity against gonococcal strain P9-17 (expressing M35 Ng-MIP, titres of 64–512) and strain 12CFX_T_003 (expressing M10 Ng-MIP, titres 8–16) but not against FA1090 (expressing M8 Ng-MIP).
As an alternative to producing recombinant protein, we engineered successfully the Nm-OM to express M2 Truncated–Nm-MIP, but lipooligosaccharide-extraction with Na-DOC was contra-indicated. Our data suggest that a multi-component vaccine containing a select number of Nm- and Ng-MIP type proteins would be required to provide broad coverage of both pathogens
Atypical, yet not infrequent, infections with neisseria species
No full textNeisseria species are extremely well-adapted to their mammalian hosts and they display unique phenotypes that account for their ability to thrive within niche-specific conditions. The closely related species N. gonorrhoeae and N. meningitidis are the only two species of the genus recognized as strict human pathogens, causing the sexually transmitted disease gonorrhea and meningitis and sepsis, respectively. Gonococci colonize the mucosal epithelium of the male urethra and female endo/ectocervix, whereas meningococci colonize the mucosal epithelium of the human nasopharynx. The pathophysiological host responses to gonococcal and meningococcal infection are distinct. However, medical evidence dating back to the early 1900s demonstrates that these two species can cross-colonize anatomical niches, with patients often presenting with clinically-indistinguishable infections. The remaining Neisseria species are not commonly associated with disease and are considered as commensals within the normal microbiota of the human and animal nasopharynx. Nonetheless, clinical case reports suggest that they can behave as opportunistic pathogens. In this review, we describe the diversity of the genus Neisseria in the clinical context and raise the attention of microbiologists and clinicians for more cautious approaches in the diagnosis and treatment of the many pathologies these species may cause.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
The potential utility of liposomes for Neisseria vaccines
No full textINTRODUCTION: Species of the genus Neisseria are important global pathogens. Neisseria gonorrhoeae (gonococcus) causes the sexually transmitted disease gonorrhea and Neisseria meningitidis (meningococcus) causes meningitis and sepsis. Liposomes are self-assembled spheres of phospholipid bilayers enclosing a central aqueous space, and they have attracted much interest and use as a delivery vehicle for Neisseria vaccine antigens.AREAS COVERED: A brief background on Neisseria infections and the success of licensed meningococcal vaccines are provided. The absence of a gonococcal vaccine is highlighted. The use of liposomes for delivering Neisseria antigens and adjuvants, for the purposes of generating specific immune responses, is reviewed. The use of other lipid-based systems for antigen and adjuvant delivery is examined briefly.EXPERT OPINION: With renewed interest in developing a gonococcal vaccine, liposomes remain an attractive option for delivering antigens. The discipline of nanotechnology provides additional nanoparticle-based options for gonococcal vaccine development. Future work would be needed to tailor the composition of liposomes and other nanoparticles to the specific vaccine antigen(s), in order to generate optimal anti-gonococcal immune responses. The potential use of liposomes and other nanoparticles to deliver anti-gonococcal compounds to treat infections also should be explored further.</p
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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