1,720,974 research outputs found
RESVERATROL-INDUCED AUTOPHAGY CONTRIBUTES TO THE INHIBITION OF EPSTEIN BARR VIRUS REPLICATION IN BURKITT’S LYMPHOMA CELLS
No full textRESVERATROL-INDUCED AUTOPHAGY CONTRIBUTES TO THE INHIBITION OF EPSTEIN BARR VIRUS REPLICATION IN BURKITT’S LYMPHOMA CELLS
De Leo Alessandra (a), Colavita Francesca (a), Arena Giuseppe (b), Mattia Elena (a)
(a) Dip. di Scienze di Sanità Pubblica e Malattie Infettive “Sanarelli”, Univ. di Roma “Sapienza”
(b) Casa Sollievo della Sofferenza Hospital, CSS-Mendel Institute, Roma
Presenting author: De Leo Alessandra, [email protected]
We have previously examined the antiviral activity of resveratrol on the replication of Epstein Barr Virus (EBV), the etiologic agent of infectious mononucleosis and associated with several types of malignancies of epithelial and lymphoid origin.
In a cellular context that allows in vitro EBV activation and lytic cycle progression through mechanisms closely resembling those that in vivo initiate and enable productive infection, we found that RV inhibited EBV lytic genes expression and the production of viral particles in a dose-dependent manner
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
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
EFFECTS OF RESVERATROL ON THE LATENT AND THE LYTIC PHASES OF EPSTEIN BARR VIRUS INFECTION
No full textIl ciclo litico di EBV e la risposta autofagica in cellule di linfoma di Burkitt
No full textIL CICLO LITICO DI EBV E LA RISPOSTA AUTOFAGICA IN CELLULE DI LINFOMA DI BURKITT
Francesca Colavita, Alessandra De Leo, Fabiola Ciccosanti, Gian Maria Fimia, Elena Mattia
Dip. di Scienze di Sanità Pubblica e Malattie Infettive “Sanarelli”, Univ. di Roma “Sapienza”
Laboratorio di Biologia Cellulare, Istituto Nazionale per le malattie infettive IRCCS ‘L. Spallanzani’, Roma
Il pathway autofagico è coinvolto in numerosi processi cellulari e rappresenta un essenziale meccanismo di difesa contro le infezioni virali. Numerosi virus per sopravvivere e propagarsi all’interno dell’ospite hanno evoluto strategie in grado di evadere e di modulare la risposta autofagica a proprio vantaggio.
Il virus di Epstein Barr (EBV), un γ-herpesvirus umano responsabile della mononucleosi infettiva ed associato a differenti tipi di neoplasie di origine epiteliale e linfoide, è caratterizzato da una infezione latente e una litica produttiva.
Al momento non ci sono informazioni su eventuali alterazioni del pathway autofagico durante il ciclo litico del virus. Scopo di questo lavoro è stato pertanto quello di analizzare l’espressione di proteine markers di autofagia a seguito della induzione del ciclo replicativo attivo di EBV e d’altro canto, di valutare l’effetto di inibitori e promotori di autofagia sulla espressione e sulla replicazione del virus. Sono stati utilizzati due modelli cellulari di linfoma di Burkitt, le cellule Akata e Mutu, in cui il ciclo litico di EBV può essere innescato mediante trattamento delle cellule, rispettivamente con IgG o con TGF β.
I risultati ottenuti dimostrano che l’attivazione della replicazione virale in cellule B infettate dal virus in forma latente, determina a tempi brevi, un aumento della componente LC3 II e della proteina p62, indici della formazione di vescicole autofagiche. Inoltre, la presenza di inibitori di autofagia quali la Bafilomicina A1 e la Spautina-1 durante l’induzione del ciclo litico di EBV provoca una sovra-regolazione dell’espressione dei geni litici e un aumento delle particelle virali prodotte.
Tali dati, indicano che il ciclo replicativo attivo di EBV è contrastato dal processo autofagico e che una inibizione di quest’ultimo, in due diversi steps del pathway degradativo, genera un aumento della espressione e della replicazione del virus. In accordo con questi risultati, cellule Akata in cui beclina-1, la proteina che innesca la risposta autofagica, è stata silenziata mediante trasfezione con lentivirus, hanno mostrato un aumento significativo dell’espressione degli antigeni virali litici rispetto alle cellule trasfettate con la sequenza “scrambled”.
Sono in corso studi atti a valutare la possibilità che EBV interferisca e moduli la risposta autofagica durante il ciclo litico
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