1,720,967 research outputs found
Eradication of persistent HBV genomes using SaCas9/3xgRNAs based gene therapy
Full text linkThe existence of stable, drug-resistant, DNA intermediate in viral replication cycle allows many viruses to persist in infected cells and is the main obstacle for curative therapy. In the case of chronic hepatitis caused by HBV (hepatitis B virus), the viral genome persists in host cells as covalently closed, circular DNA (cccDNA). Here we demonstrate that the CRISPR/Cas9 gene editing technology cleaves HBV genome efficiently and specifically. To ensure successful disruption of cccDNA, we multiplexed three different gRNAs, targeting regions of viral polymerase gene (P) conserved among all ten HBV genotypes, in a single “all in” SaCas9/gRNAs AAV vector. Additionally, to achieve maximum gene editing efficiency, we added to our construct a shRNA-expressing cassette, targeting the viral trans-activator X mRNA, which should result in suppression of virus expression in treated cells. Transfecting our pX601-HBV3xgRNAs/shRNA plasmid into HepG2.2.15 cells (Vitro chronic hepatitis model for HBV) resulted in a significant reduction of viral DNA levels. Sanger sequencing of extracted PCR products confirmed canonical SaCas9 mediated cleavage of viral DNA. Disruption HBV cccDNA led to a significant reduction of intracellular viral DNA and RNA levels, as analyzed by qRT-PCRs. In summary, we designed and validated in vitro an application of SaCas9/gRNA gene editing platform, in a chronic hepatitis model, to directly target and cleave persistent episomal HBV genome. Our data set the stage for the next, pre-clinical phase of research in the animal model, toward developing a gene therapy-based treatment for patients with a chronic HBV hepatitis
Usufrutto, pegno e sequestro di quota
No full textLa riforma del diritto societario ha inteso conferire autonomia alla disciplina della srl dotandola di una regolamentazione che esalta l'autonomia decisionale delle parti. Il nuovo assetto pone dei problemi interpretativi in ordine all'esercizio di taluni diritti del socio la cui risoluzione non puo' prescindere considerazione del sistema nel suo complesso
Expression of HERV Genes as Possible Biomarker and Target in Neurodegenerative Diseases
No full textHuman endogenous retroviruses (HERVs) are genetic parasites, in-between genetics and environment. Few HERVs retain some coding capability. Sometimes, the host has the advantage of some HERV genes; conversely, HERVs may contribute to pathogenesis. The expression of HERVs depends on several factors, and is regulated epigenetically by stimuli such as inflammation, viral and microbial infections, etc. Increased expression of HERVs occurs in physiological and pathological conditions, in one or more body sites. Several diseases have been attributed to one or more HERVs, particularly neurological diseases. The key problem is to differentiate the expression of a HERV as cause or effect of a disease. To be used as a biomarker, a correlation between the expression of a certain HERV and the disease onset and/or behavior must be found. The greater challenge is to establish a pathogenic role. The criteria defining causal connections between HERVs and diseases include the development of animal models, and disease modulation in humans, by anti-HERV therapeutic antibody. So far, statistically significant correlations between HERVs and diseases have been achieved for HERV-W and multiple sclerosis; disease reproduction in transgenic animals was achieved for HERV-W and multiple sclerosis, and for HERV-K and amyotrophic lateral sclerosis. Clinical trials for both diseases are in progress
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
Early reduction of the splicing factor2/alternative splicing factor: a cellular inhibitor of the JC polyomavirus in natalizumab-treated MS patients long before developing progressive multifocal leukoencephalopathy
No full textNatalizumab is effective against relapsing-remitting multiple sclerosis (MS) but increases the risk of progressive multifocal leukoencephalopathy (PML), which is caused by the activation of the JCV polyomavirus. SF2/ASF (splicing factor2/alternative splicing factor) is a potent cellular inhibitor of JCV replication and large T-antigen (T-Ag) expression. We reported that SF2/ASF levels in blood cells increase during the first year of natalizumab therapy and decrease thereafter, inversely related to T-Ag expression, and suggested a correlation with JCV reactivation. Here, we report SF2/ASF levels of longitudinal blood samples of two patients undergoing natalizumab therapy, who developed PML while monitored, in comparison to natalizumab-treated controls and to one-off PML samples. After 6 months of therapy, SF2/ASF levels of the two cases were reduced, instead of increased, and their overall SF2/ASF levels were lower than those from natalizumab controls. Since SF2/ASF inhibits JCV, its early reduction might have a role in subsequent PML. We are aware of the limitations of the study, but the uniqueness of serial blood samples collected before and after PML onset in natalizumab-treated patients must be stressed. If confirmed in other patients, SF2/ASF evaluation could be a new and early biomarker of natalizumab-associated PML risk, allowing an 18-24-month interval before PML onset (presently ~ 5 months), in which clinicians could evaluate other risk factors and change therapy
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
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