1,721,074 research outputs found
The Streptococcus agalactiae complement interfering protein combines multiple complement-inhibitory mechanisms by interacting with both C4 and C3 ligands
No full textGroup B Streptococcus (GBS) colonizes the human lower intestinal and genital tracts and constitutes a major threat to neonates from pregnant carrier mothers and to adults with underlying morbidity. The pathogen expresses cell-surface virulence factors that enable cell adhesion and penetration and that counteract innate and adaptive immune responses. Among these, the complement interfering protein (CIP) was recently described for its capacity to interact with the human C4b ligand and to interfere with the classical- and lectin-complement pathways. In the present study, we provide evidence that CIP can also interact with C3, C3b, and C3d. Immunoassay-based competition experiments showed that binding of CIP to C3d interferes with the interaction between C3d and the complement receptor 2/cluster of differentiation 21 (CR2/CD21) receptor on B cells. By B-cell intracellular signaling assays, CIP was confirmed to down-regulate CR2/CD21-dependent B-cell activation. The CIP domain involved in C3d binding was mapped via hydrogen deuterium exchange–mass spectrometry. The data obtained reveal a new role for this GBS polypeptide at the interface between the innate and adaptive immune responses, adding a new member to the growing list of virulence factors secreted by gram-positive pathogens that incorporate multiple immunomodulatory functions.—Giussani, S., Pietrocola, G., Donnarumma, D., Norais, N., Speziale, P., Fabbrini, M., Margarit, I. The Streptococcus agalactiae complement interfering protein combines multiple complement-inhibitory mechanisms by interacting with both C4 and C3 ligands
Archivio d'Autore: le carte di Fabrizio De André
No full textL’attenzione verso gli archivi personali ha consentito nel corso degli ultimi decenni di scoprire e valorizzare sedimenti documentari prodotti da intellettuali e artisti attivi nel corso del XIX e XX secolo: scrittori, personalità del mondo delle arti e della musica, uomini politici, architetti, ecc. Tra le forme d’arte tipiche del mondo contemporaneo spicca la così detta canzone d’autore, un fenomeno culturale che da un lato può trovare riferimenti nella canzone popolare tradizionale, dall’altro si raccorda al melodramma otto-novecentesco in considerazione della stretta interrelazione che viene a costituirsi nel rapporto tra parole e musica. La centralità del testo cantato ha inoltre fatto sì che proprio a questo genere artistico sia stata data una valenza particolare, ritenendolo una forma tra le più interessanti di poesia contemporanea. Da tutto ciò discende la rilevanza che possiamo riconoscere agli archivi prodotti da personalità di rilievo dell’ampio contesto della canzone d’autore, i quali illuminano sui processi creativi che hanno portato alla nascita delle canzoni stesse. Nell’inventario relativo alle carte di uno dei massimi cantautori del Novecento – Fabrizio de André – si dà conto della stratificazione dei documenti conservati, prevalentemente relativi alla fase della creazione testuale, e li si descrivono in modo analitico così da ricomporre le modalità formative dell’archivio. L’ampia introduzione serve in generale a comprendere le reali potenzialità di questo genere di documentazione per studiare il fenomeno della canzone d’autore e nello specifico ad illustrare le vicende formative e conservative dell’archivio deandreiano
A long journey to the cytosol: what do we know about entry of typeI RIPs inside a mammalian cell?
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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
From Immunotoxins to Suicide Toxin Delivery Approaches: Is There a Clinical Opportunity?
Full text linkSuicide gene therapy is a relatively novel form of cancer therapy in which a gene coding for enzymes or protein toxins is delivered through targeting systems such as vesicles, nanoparticles, peptide or lipidic co-adjuvants. The use of toxin genes is particularly interesting since their catalytic activity can induce cell death, damaging in most cases the translation machinery (ribosomes or protein factors involved in protein synthesis) of quiescent or proliferating cells. Thus, toxin gene delivery appears to be a promising tool in fighting cancer. In this review we will give an overview, describing some of the bacterial and plant enzymes studied so far for their delivery and controlled expression in tumor models
Solubility improvement of an anthrax toxin peptide inhibitor by rational aminoacid randomization
No full textWe previously described a potent anthrax toxin inhibitor, based on a phage-library-selected peptide sequence, synthesized as a tetra-branched molecule on a lysine core and further modified for improvement of activity [Pini et al., Biochem. J., 2006, 395, 157]. This branched peptide had very low solubility because of several hydrophobic residues in the peptide sequence. This complicated molecule purification and manufacturing. Here we report a rational modification of the peptide sequence, obtained by construction and selection of several mini libraries of branched peptides, containing sequences randomized in non crucial positions of the original peptide. Mini libraries were screened for solubility and inhibitory activity. This procedure enabled us to obtain a new peptide with a better solubility and identical inhibitory activity
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