1,721,103 research outputs found
Genotypic resistance tests for the management of the HIV-infected patient with non-B viral isolates
No full textWitness for the prosecution: The dominating HIV-1 subtype in Europe and in the USA is the B subtype, but the prevalence of circulating recombinant forms and non-B subtypes (nBS) in Europe has increased. HIV-1 group O strains are spontaneously resistant to non-nucleoside analogue reverse transcriptase inhibitors (NNRTI) and little is known about the antiretroviral (ARV) drug susceptibility of nBS clinical isolates. Controlled randomized trials showing a clinical benefit of a treatment guided by HIV-1 resistance testing at virological failure have been conducted on subtype B. Thus, the result cannot be simply extended to nBS. In nBS, the frequency or amplification failure is increased, but retesting failed samples with an alternative set of polymerase chain reaction primers improves the success of amplification. The major problem is the reliability of genotypic resistance tests (GRT) owing to misinterpretation of the obtained amino acid mutations, the background sequence in nBS being different from the standard used in the commercial kits or in the web-based HIV-1 resistance interpretation tools. At the moment, no nBS database is available to help in the interpretation of the protease and RT sequence results. Furthermore, the mutational pattern of specific ARV drugs may be different, in particular with subtype C and G. In conclusion, in patients with nBS the indication to for at virological failure may exists, even in the absence of clinical evidence, but the results have to be interpreted by experts with particular caution. Witness for the defence: The extensive variability of HIV-1 has a potential impact on epidemiology, diagnosis, therapy and the prevention of infection. Nine different major subtypes of group M (A-D, F-H, J and K) circulate to varying extents in populations around the globe together with the circulating recombinant forms (CRF) owing to intersubtype recombinations. Although viruses belonging to the HIV-1 B clade are still predominant in Europe, the USA and Australia, an increasing prevalence of non-clade B subtypes and CRF has been reported by several surveys in previously homogeneous clade B countries. As current ARV have been designed using subtype B strains and resistance mutations have been characterized on this subtype, the increasing global spread of HIV subtypes highlights the need to determine the activity of anti-HIV drugs against subtypes or CRF other than subtype B
CD4 count in HIV infection is positively correlated to interferon-gamma and negatively correlated to interleukin-10 in vitro production
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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
Persisting HIV-1 replication triggered by acute hepatitis A virus infection
No full textWe report the case of two patients in whom acute hepatitis A was associated with a marked and prolonged increase in human immunodeficiency virus type 1 (HIV-1) viral load. Although in one patient the rise in HIV-1 RNA might also have been related to the interruption of antiretroviral therapy, we also observed a similar pattern in the other patient who had a stable undetectable plasma viraemia prior to acute hepatitis and never received treatment with anti-retrovirals. Our observation supports the hypothesis that immune activation that is induced by acute hepatitis A virus (HAV) infection may trigger HIV-1 replication. This highlights the importance of maintaining antiretroviral therapy throughout the acute phase of hepatitis A and of preventing HAV infection through active immunization
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
Modulation of the locomotory capacity of human large granular lymphocytes
No full textThe regulation of the migratory capacity of Percoll-purified large granular lymphocytes (LGL) into nitrocellulose filters was studied in a 2-hr assay with the use of modified Boyden chambers. Compounds that stimulate the natural killer cytotoxic function of LGL, such as interferons (natural β, recombinant αA, recombinant hybrid α A/D, recombinant γ), recombinant interleukin-2, and inactivated streptococci (OK 432), augmented the capacity of LGL to penetrate into filters spontaneously in the absence of chemoattractants in the lower compartment of the chamber. These compounds did not increase the LGL responsiveness to chemoattractants. Phorbol 12-myristate 13-acetate did not appreciably affect the locomotory capacity of LGL but augmented their cytotoxic activity. Thus the cytotoxic function and locomotion of LGL in response to biological response modifiers can be dissociated
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