1,721,022 research outputs found
The aspartate aminotransferase-like domain of Firmicutes mocr transcriptional regulators
No full textBacterial MocR transcriptional regulators possess an N-terminal DNA-binding domain containing a conserved helix-turn-helix module and an effector-binding and/or oligomerization domain at the C-terminus, homologous to fold type-I pyridoxal 5′-phosphate (PLP) enzymes. Since a comprehensive structural analysis of the MocR regulators is still missing, a comparisons of Firmicutes MocR sequences was undertook to contribute to the understanding of the structural characteristics of the C-terminal domain of these proteins, and to shed light on the structural and functional relationship with fold type-I PLP enzymes. Results of this work suggest the presence of at least three subgroups within the MocR sequences and provide a guide for rational site-directed mutagenesis studies aimed at deciphering the structure-function relationships in this new protein family
The impact of viral molecular diversity on the clinical presentation and outcome of acute hepatitis B in Italy
No full text: The incidence of acute hepatitis B (AHB) in Italy, mostly sustained by hepatitis B virus (HBV) genotype D, has significantly decreased in the last two decades, but the new HBV strains introduced through immigrant populations from countries with a higher endemicity constitute a new emergency. HBV-genotype D still predominates in AHB, the subgenotype D3 being associated with parenteral transmission, and the recently emerging subgenotype A2 with unsafe sexual intercourse. Genetic, phylogenetic and evolutional analyses are powerful tools for countries with high immigration rates to monitor new viral strains with different aggressiveness and a different response to therapy
Evidence of immune response to BNT162b2 COVID-19 vaccine in systemic lupus erythematosus patients treated with Belimumab
No full textOBJECTIVES: To evaluate humoral and cell-mediated response after three doses of BNT162b2 SARS-CoV-2 vaccine in patients with systemic lupus erythematosus (SLE) treated with Belimumab (BLM). METHODS: SLE patients were vaccinated with three doses of BNT162b2-mRNA vaccine (two-dose primary vaccination, third booster dose after 6 months). The humoral immune response was assessed one and 6 months after the second dose (T1, T2), and 6 months after the booster dose (T3). Serological assay was performed (The Liaison® SARS-CoV-2 TrimericS IgG chemiluminescent). Spike-specific T-cell response was monitored 6 months after the second vaccine dose and the percentage of cytokines producing T cells was assessed by flow cytometry. RESULTS: Twelve patients [12F; median age 46 years (IQR 8.25); median disease duration 156 months (IQR 188)] were enrolled. At T1, all patients showed seroconversion (median anti-Spike IgG levels 1610 BAU/mL, IQR 1390). At T2––day of the third dose––a significant reduction of median anti-Spike IgG antibodies levels was observed [214 BAU/mL (IQR 94); p = 0.0009]. Anti-Spike IgG were significantly increased at T3, reaching a median value of 1440 BAU/mL (IQR 1316; p = 0.005). Despite declining humoral immunity, almost 60% of patients mounted a virus-specific CD4 + T-cell response 6 months after primary vaccination. CONCLUSIONS: BLM does not impair humoral response to primary BNT162b2 SARS-CoV-2 vaccination. During the follow-up, a decline in antibody levels is evident and the third dose is crucial to increase the specific immune response. Finally, we observed a recall T-cell response to the Spike antigen 6 months after the first vaccination cycle
Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) and Bayesian phylogenetic analysis to characterize Candida clinical isolates
No full textClinical Candida isolates from two different hospitals in Rome were identified and clustered by MALDI-TOF MS system and their origin and evolution estimated by Bayesian phylogenetic analysis. The different species of Candida were correctly identified and clustered separately, confirming the ability of these techniques to discriminate between different Candida species. Focusing MALDI-TOF analysis on a single Candida species, Candida albicans and Candida parapsilosis strains clustered differently for hospital setting as well as for period of isolation than Candida glabrata and Candida tropicalis isolates. The evolutionary rates of C. albicans and C. parapsilosis (1.93×10(-2) and 1.17×10(-2)substitutions/site/year, respectively) were in agreement with a higher rate of mutation of these species, even in a narrow period, than what was observed in C. glabrata and C. tropicalis strains (6.99×10(-4) and 7.52×10(-3)substitutions/site/year, respectively). C. albicans resulted as the species with the highest between and within clades genetic distance values in agreement with the temporal-related clustering found by MALDI-TOF and the high evolutionary rate 1.93×10(-2)substitutions/site/year
Genetic diversity in the env V1-V2 region of proviral quasispecies from long-term controller MHC-typed cynomolgus macaques infected with SHIVSF162P4cy
Full text linkIntra-host evolution of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) has been shown by viral RNA analysis in subjects who naturally suppress plasma viremia to low levels, known as controllers. However, little is known about the variability of proviral DNA and the inter-relationships among contained systemic viremia, rate of reservoir reseeding and specific major histocompatibility complex (MHC) genotypes, in controllers. Here, we analysed the proviral DNA quasispecies of the env V1-V2 region, in PBMCs and in anatomical compartments of 13 long-term controller monkeys after 3.2 years of infection with simian/human immunodeficiency virus (SHIV)SF162P4cy. A considerable variation in the genetic diversity of proviral quasispecies was present among animals. Seven monkeys exhibited env V1-V2 proviral populations composed of both clusters of identical ancestral sequences and new variants, whereas the other six monkeys displayed relatively high env V1-V2 genetic diversity with a large proportion of diverse novel sequences. Our results demonstrate that in SHIVSF162P4cy-infected monkeys there exists a disparate pattern of intra-host viral diversity and that reseeding of the proviral reservoir occurs in some animals. Moreover, even though no particular association has been observed between MHC haplotypes and the long-term control of infection, a remarkably similar pattern of intra-host viral diversity and divergence was found within animals carrying the M3 haplotype. This suggests that in animals bearing the same MHC haplotype and infected with the same virus, viral diversity follows a similar pattern with similar outcomes and control of infection
Hepatitis A virus in a medical setting in Madagascar: a lesson for public health
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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
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
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