1,721,162 research outputs found
Current treatments for chronic hepatitis B virus infections
Over 240 million people worldwide are chronically infected with hepatitis B virus (HBV) and although a prophylactic vaccine and effective antiviral therapies are available, no cure exists. Curative regimens are urgently needed because up to one million deaths per year are caused by HBV-related liver cancer and end-stage liver disease. HBV is an hepatotropic virus which belongs to the Hepadnaviridae family and replicates its DNA genome via a reverse transcriptase mechanism. Effective therapies have been developed for chronic hepatitis B (CHB) infection in the last two decades. They rely on the use of interferon alpha and its pegylated formulation, and on nucleos(t)ide analogs that inhibit viral polymerase activity. Their results are discussed in this review as well as future perspectives
Challenges to a Cure for HBV Infection
Current first-choice treatments for chronic hepatitis B are able to efficiently induce viral suppression in the majority of patients, but life-long therapy is needed to maintain infection under control due to their inability to eliminate the virus from infected hepatocytes. The residual viral replication and antigen production in most patients under treatment substantially contributes to the residual risk of hepatocarcinogenesis. New therapeutic approaches are needed to overcome hepatitis B virus persistence in the infected cells, or at least to control its transcriptional and replicative activity. In this review, the authors discuss the key points of the viral life cycle and host immune responses that need to be addressed to achieve a functional cure, or even a complete cure, allowing a finite duration of treatment and preventing virus reactivation and liver disease progression in a significantly higher number of patients than what is currently attained
HBV cure. why, how, when.
Current HBV treatments control replication and liver disease progression in the vast majority of treated patients. However, HBV patients often require lifelong therapies due to the persistence of transcriptionally active viral cccDNA mini-chromosome in the nucleus, which is not directly targeted by current antiviral therapies. A true complete cure of HBV would require clearance of intranuclear cccDNA from all infected hepatocytes. An intermediate but still relevant step forward that would allow treatment cessation would be reaching a functional cure, equivalent to resolved acute infection, with a durable HBsAg loss ± anti-HBs seroconversion, undetectable serum DNA and persistence of cccDNA in a transcriptionally inactive status. Recent advances in technologies and pharmaceutical sciences, including the cloning of the mayor HBV receptor (i.e. the NTCP transporter) and the development in vitro HBV infection models, have heralded a new horizon of innovative antiviral and immune-therapeutic approaches
Non-invasive biomarkers for chronic hepatitis B virus infection management
Chronic hepatitis B virus (HBV) infection remains a major health burden with over 250 million cases worldwide. This complex infection can lead to chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. Complete recovery is seldom achieved due to the persistence in infected hepatocytes of covalently closed circular (ccc)DNA, which is not targeted by current antiviral therapies. Routine circulating biomarkers used for clinical monitoring of patients do not accurately reflect the cccDNA pool and transcriptional activity. New biomarkers, such as serum HB core-related Ag and circulating HBV RNAs, are under development. In this review, we discuss surrogate non-invasive biomarkers for evaluating intrahepatic cccDNA abundance and transcriptional activity. We also present their relevance for improving the classification of patients with regards to their natural history and for evaluating novel compounds to assess target engagement and to define new virological endpoints
Perspectives and limitations for nucleo(t)side analogs in future HBV therapies
The latest generation of nucleo(t)side analogs (NAs) provide robust virus suppression with high barrier to resistance. Long term NAs treatment is associated with a partial restoration in HBV-specific T-cell functions, regression of fibrosis, no disease progression and a reduction of HCC risk but rarely lead to cure and life-long treatments is often required. New insights into the hepatitis B viral life cycle and the host immune response have expanded the potential targets for drug therapies with interesting antiviral candidates and novel immunotherapeutic approaches in early stage development. Here we review the mode of action of current drugs (NAs and PEG IFN) and new classes of anti-HBV compounds, focusing on the possible role of nucleo(t)side analogs in future combination therapies
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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
IFN-alpha/beta target genes repertoires modulated by exogenous type I IFN and by the endogenous HBV-induced IFN-response in liver cells.
- …
