Search results for "Replication"
showing 10 items of 489 documents
Management of chronic hepatitis C in childhood: The impact of therapy in the clinical practice during the first 2 decades
2011
Background and aim: Treatment of chronic hepatitis C in children is controversial and its role in the clinical practice is unknown. We retrospectively investigated the impact of treatment in a large cohort of children with chronic hepatitis C over the past 20years. Methods: 376 hepatitis C virus RNApositive children were recruited consecutively in five Italian centres since 1990and followed for1–17years. Results: 86 (23%)subjects were treated: 73 with recombinant interferon alone and 13 with pegylated-interferon and ribavirin. Sustained clearance of hepatitis C virus RNA was observed in 25%of the former, in 92%of the latter and in 9% of untreated cases(p < 0.001). Loss of viraemia was re…
Significance of IgG and IgM HCV antibody secretion in vitro in patients with chronic hepatitis C: correlation with disease activity and response to i…
1994
Hepatitis C virus antibodies are found in the serum of most patients with chronic hepatitis C. However, the significance of the humoral response is still uncertain. In this study, in vitro IgG and IgM anti-hepatitis C virus secretion by peripheral blood mononuclear cells of patients with chronic hepatitis C was analyzed. Peripheral-blood mononuclear cells from 21 of 36 patients (58.3%) secreted IgG anti-hepatitis C virus in vitro, as demonstrated with anti-hepatitis C virus—specific enzyme immunoassays and recombinant immunoblot assays. Ten of the 36 patients (27.8%) showed both IgG and IgM anti-hepatitis C virus core in vitro. In 9 of these 10 patients, IgM anti-hepatitis C virus was also …
Evolutionary psychological consumer research:Bold, bright, but better with behavior
2020
Abstract This special issue includes state-of-the-art papers that leverage various theories from evolutionary psychology (EP) to shed light on important consumption-related phenomena. Our guest editorial provides an overview of this EP-based consumer research, highlighting the key content, common denominators, and significant strengths of the articles. The papers cover a wide variety of topics, characteristic of evolutionary-informed research, that we structure around the following three themes: (1) Mating, marketing, and meaningful motivating forces, (2) Conspicuous consumption and salient signs of “showing off,” and (3) Human hormones and biologically-based business research. We close our…
We need more replication research – A case for test-retest reliability
2017
Following debates in psychology on the importance of replication research, we have also started to see pleas for a more prominent role for replication research in medical education. To enable replication research, it is of paramount importance to carefully study the reliability of the instruments we use. Cronbach’s alpha has been the most widely used estimator of reliability in the field of medical education, notably as some kind of quality label of test or questionnaire scores based on multiple items or of the reliability of assessment across exam stations. However, as this narrative review outlines, Cronbach’s alpha or alternative reliability statistics may complement but not replace psyc…
Parasites as fish population tags and pseudoreplication problems: the case of striped red mullet Mullus surmuletus in the Spanish Mediterranean
2007
AbstractStudies of parasites as fish population tags often apply a single round of sampling to identify potential stocks or predict harvest localities. However, the lack of replication generates pseudoreplication, implicitly assuming that infection levels are more similar between samples from the same locality than between samples from different localities. We evaluated this assumption in the case of the striped red mullet Mullus surmuletus in three localities of the Spanish Mediterranean separated by c. 300 km. Samples of 25 fish of similar size were collected in each locality in the summer and autumn of two consecutive years. Prevalence and abundance of three long-lived parasite taxa diff…
Slow and fast evolving endosymbiont lineages: positive correlation between the rates of synonymous and nonsynonymous substitution
2015
The availability of complete genome sequences of bacterial endosymbionts with strict vertical transmission to the host progeny opens the possibility to estimate molecular evolutionary rates in different lineages and understand the main biological mechanisms influencing these rates. We have compared the rates of evolution for non-synonymous and synonymous substitutions in nine bacterial endosymbiont lineages, belonging to four clades (Baumannia, Blochmannia, Portiera, and Sulcia). The main results are the observation of a positive correlation between both rates with differences among lineages of up to three orders of magnitude and that the substitution rates decrease over long endosymbioses.…
Mode of selection and experimental evolution of antiviral drugs resistance in vesicular stomatitis virus
2004
Abstract The possession of an antiviral resistance mutation benefits a virus when the corresponding antiviral is present. But does the resistant virus pay a fitness cost when the antiviral is absent? Would an evolutionary history of association between a genotype and a resistance mutation overcome this cost by changes compensating the harmful side-effect of resistance mutations? Are combined therapies more effective against the rise of resistant viruses or against evolutionary compensations? To explore all these questions, we took an experimental evolution approach. After selecting vesicular stomatitis virus (VSV) populations able to replicate under increasing concentrations of ribavirin an…
Overcoming drug resistance in HSV, CMV, HBV and HCV infection.
2015
Although vaccination has provided as a very efficient preventive tool, antiviral therapy is still needed to control viral infections not avoidable by prophylaxis with vaccines; those caused by viruses for which a vaccine is available, but vaccination is not universally implemented or does not result in complete, long-term protection; and in immunocompromised individuals with reduced immune control of viral replication. After more than 50 years of the first licensing for an antiherpetic drug, novel compounds for herpes-simplex viruses and human cytomegalovirus will open new strategies for better control and management of these two recurrent viral infections. Besides, the development and use…
Chronic hepatitis B: who to treat and which choice of treatment?
2009
The goal of antiviral therapy in patients with chronic hepatitis B is to prevent, through persistent suppression of HBV replication, cirrhosis and hepatocellular carcinoma. Currently, seven drugs are available: IFN-alpha, pegylated interferon, lamivudine, adefovir dipivoxil, entecavir, telbivudine and tenofovir. The choice of the drugs should always take into consideration the clinical features of patients, the antiviral efficacy of each drug, the risk of developing resistance, the long-term safety profile, the method of administration and the cost of therapy. Ideal candidates for treatment are hepatitis B e antigen-positive patients with a prolonged phase of immune clearance and hepatitis …
Evolutionary history conditions the timing of transmission in vesicular stomatitis virus.
2001
It has been postulated that early transmitted viruses would evolve to be more virulent than late transmitted ones. The reason for this prediction is that early transmission selects for rapid viral replication and, consequently, rapid host death, whereas late transmission would select for slow-replicating viruses that permit longer survival to the host. To test this prediction, experimental lineages of vesicular stomatitis virus (VSV) had been adapted to three different transmission dynamics during more than 100 generations. Transmission dynamic differed in the stage of infection at which transmission took place: early, intermediate or late. Regardless the timing of transmission imposed duri…