1,720,983 research outputs found
NETosis Dysregulation in Adenosine Deaminase 2 deficiency (DADA2)
No full textIntroduction: Deficiency of Adenosine deaminase 2 (DADA2) is a monogenic autoinflammatory disorder presenting a broad spectrum of clinical manifestations, including vasculitis, immunodeficiency and hematologic disease. The genetic mutations in ADA2 gene have been associated to an insufficient ADA2 activity leading to reduction in deamination of adenosine to deoxyadenosine, and a consequent accumulation of extracellular adenosine. The pathogenic mechanisms investigated so far have elucidated a skewed polarization from the M2 macrophage subtype to the proinflammatory M1 subtype with an increased production of inflammatory cytokines (TNF-α, Interferon IFN). More recently a chronic neutrophil activation and a dysregulation of NETosis, as process triggered by extracellular Adenosine, inducing TNFα secretion from Macrophages stimulated by NETs, has been implicated in the pathogenesis of DADA2.
Objectives: The aim of the project is to dissect NETosis directly in neutrophils isolated from DADA2 patients and healthy controls (HDs), and to quantify suicidal and vital NETosis induced by several stimuli. To determine if NET epitopes can change depending from the inflammatory microenvironment and if protein composition of NETs is disease specific, we used quantitative proteomics approach to characterize NET proteins, released from neutrophils after different stimuli in DADA2 patients, HDs and nongenetic vasculitis. Moreover, we investigated the mechanisms of NETs removal.
To verify if NETs can influence maturation or inflammatory phenotype of DCs, we characterized peripheral myeloid Dendritic cells (mDCs) and plasmocytoid DCs (pDC) in DADA2 patients and analyzed in vitro moDC maturation and cytokine production in presence of NETs.
Methods: We analyzed and quantified both suicidal and vital NETosis by Imaging Flow Citometry (IFC): neutrophils isolated from peripheral blood from DADA2 patients and HDs were stimulated in vitro with different stimuli (PMA, Adenosine and LPS) to induce NETosis and were analyzed in the ImageStreamXMark II IFC equipped with a MultiMag system. We evaluated also NETs remnants and DNAse in the plasma samples by ELISA assay. We used quantitative proteomics approach to characterize NET proteins, released from neutrophils after different stimuli in DADA2 patients, HDs and nongenetic vasculitis: LC-MS/MS analyses were conducted on Orbitrap Fusion Tribrid mass spectrometer and NET protein quantification was carried out using Label-Free Quantification method.
We isolated monocytes from peripheral blood with microbeads and we generated moDC after culture stimulation with LPS/NETs. On the 7th day we analyzed by flow cytometry the phenotype and the markers of differentiation. Quantification of cytokines was performed by flow cytometry bead array.
Results: We enrolled 14 patients with Adenosine Deaminase 2 deficiency diagnosis who underwent blood sampling at out Center, collecting also plasma samples from further 6 genetically confirmed DADA2 patients enrolled by other Italian Pediatric Rheumatology Units.
Neutrophils from DADA2 show a significant increased suicidal NETosis, identified as nuclear decondensation and Myeloperoxidase (MPO) colocalization with DNA, following PMA stimulation and we observed an increase also with LPS and Adenosine. Then we analyzed vital NETosis, identified as elongated shape of cells, nuclei polarized within the cell and not colocalized with MPO and we found an increased vital NETosis in DADA2 neutrophils. Accordingly, plasmatic levels of circulating nucleosomes (NET remnants) were elevated in patients; DNAse levels were normal but the activity was reduced. We set up experimental conditions for proteomic analysis of NETs, induced by PMA, Adenosine and TNFα, testing two patients, two HDs and two patients with non-genetic vasculitis: in total we identified 1770 proteins among which a hundred of proteins were significantly up or down-modulated in DADA2 NETs compared to controls NETs.
DC phenotype in DADA2 patients result concordant with HD, as well as moDCs cytokine production after LPS stimulation. We observed a stimulatory effect of NETs towards induction of TNF alpha, IL-6 production and IP-10 from moDCs in both HD and DADA2.
Conclusion: Our findings confirm a dysregulation in NETosis process in DADA2 patients, that can be induced by both LPS and adenosine. An increase of vital NETosis was also identified. Proteomic profile of NETs isolated from DADA2 is different from HD and PAN patients: NETs are qualitatively different between HD and DADA2. NETs in DADA2 may therefore interact differently with innate immunity compartment, stimulating DCs to produce citokines, contributing to the typical inflammatory phenotype
An Atypical Case of Aphasia: Transitory Ischemic Attack in a 13-Year-Old Patient with Asymptomatic SARS-CoV-2 Infection
No full textWe report the case of a 13-year-old patient, female, born in Northern Italy, who presented with an acute episode of aphasia, lasting about 15 min, accompanied by left arm dysesthesia. The state of consciousness remained preserved throughout the episode. After a first clinical evaluation at second-level hospital, the patient was sent to our institute for further investigations. Brain MRI performed at admission showed no noteworthy structural alterations. Electroencephalogram was not significant, as was the echocardiographic examination. ECG was normal, except for a corrected-QT at the upper limits of the normal range for age and gender. The neurological examination was substantially normal for the entire duration of the hospital stay. The symptomatology initially described has never reappeared. Blood tests were substantially negative, in particular thrombophilic screening excluded hereditary-familial thrombophilic diseases. Color doppler ultrasound of the supra-aortic trunks, splanchnic vessels and lower limbs were also normal. Only positivity to SARS-CoV-2 serology is reported. In the recent clinical history there were no symptoms attributable to symptomatic coronavirus infection
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
Emotional and behavioral problems in adolescents following childhood arterial ischemic stroke
No full textAdenosine Deaminase 2 Deficiency (DADA2): A Crosstalk Between Innate and Adaptive Immunity
No full textDeficiency of Adenosine deaminase 2 (DADA2) is a monogenic autoinflammatory disorder presenting with a broad spectrum of clinical manifestations, including immunodeficiency, vasculopathy and hematologic disease. Biallelic mutations in ADA2 gene have been associated with a decreased ADA2 activity, leading to reduction in deamination of adenosine and deoxyadenosine into inosine and deoxyinosine and subsequent accumulation of extracellular adenosine. In the early reports, the pivotal role of innate immunity in DADA2 pathogenic mechanism has been underlined, showing a skewed polarization from the M2 macrophage subtype to the proinflammatory M1 subtype, with an increased production of inflammatory cytokines such as TNF-α. Subsequently, a dysregulation of NETosis, triggered by the excess of extracellular Adenosine, has been implicated in the pathogenesis of DADA2. In the last few years, evidence is piling up that adaptive immunity is profoundly altered in DADA2 patients, encompassing both T and B branches, with a disrupted homeostasis in T-cell subsets and a B-cell skewing defect. Type I/type II IFN pathway upregulation has been proposed as a possible core signature in DADA2 T cells and monocytes but also an increased IFN-β secretion directly from endothelial cells has been described. So far, a unifying clear pathophysiological explanation for the coexistence of systemic inflammation, immunedysregulation and hematological defects is lacking. In this review, we will explore thoroughly the latest understanding regarding DADA2 pathophysiological process, with a particular focus on dysregulation of both innate and adaptive immunity and their interacting role in the development of the disease
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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