1,721,047 research outputs found
Human CD4+ regulatory T cells and activation-induced tolerance
No full textAbstract not availableEhud Hauben, Maria Grazia Roncarol
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
Activation of the aryl hydrocarbon receptor promotes allograft-specific tolerance through direct and dendritic cell-mediated effects on regulatory T cells
No full textVAF347 is a low-molecular-weight compound, which activates the aryl hydrocarbon receptor (AhR). Herein, we report that oral administration of a water-soluble derivative of VAF347 (VAG539) promotes long-term graft acceptance and active tolerance in Balb/c mice that receive a transplant of MHC-mismatched pancreatic islet allografts. In vivo VAG539 treatment results in increased frequency of splenic CD4(+) T cells expressing CD25 and Foxp3, markers associated with regulatory T (Tr) cells, and in vitro VAF347 treatment of splenic CD4+ T cells improved CD4(+)CD25(+)Foxp3(+) T-cell survival. Interestingly, transfer of CD11c(+) dendritic cells (DCs), but not of CD4+ T or CD19(+) B cells, from VAG539-treated long-term tolerant hosts into mice that recently underwent transplantation resulted in donor (C57BI/6)-specific graft acceptance and in a significantly higher frequency of splenic CD4(+)CD25(+)Foxp3(+) Tr cells. Furthermore, the transfer of CD4(+)CD25(+) T cells from these mice into mice that recently underwent transplantation promoted graft acceptance. Similarly, cell therapy with in vitro VAF347-treated bone marrow-derived mature DCs prevented islet graft rejection, and reduced OVA-specific T-cell responses in OVA-immunized mice. Collectively, our data indicate that AhR activation induces islet allograft-specific tolerance through direct as well as DC-mediated effects on Tr-cell survival and function
Multimodular assessment of a calcified extraradicular deposit on the root surfaces of a mandibular molar.
No full textAim: To achieve a better understanding of a calcified extraradicular deposit on the apical root surfaces of a mandibular first molar associated with a radicular cyst and a sinus tract. A multimodular approach was applied using a combination of multiple investigation methods. Summary: This case report presents a mandibular first molar with a calcified extraradicular deposit on the apical root surfaces of both roots. An apical periodontitis lesion was present and a sinus tract served as the only communication with the oral cavity. Diagnosis and treatment planning were based on clinical, radiographic (two- and three-dimensional) and ultrasound examination. The tooth was further analysed after extraction using microscopic imaging, nano-computed tomography (nano-CT), hard- and soft tissue histology and electron probe microanalysis. This multimodular approach revealed the calculus-like appearance and mineral composition of the extraradicular deposit. Multiple hypotheses about its aetiology are discussed. Key learning points: Calcified extraradicular deposits can develop on the apical root surfaces of teeth with apical periodontitis in association with a radicular cyst and sinus tract. A sinus tract can serve as the only communication between the apical lesion and the oral cavity whilst no periodontal defects are present. The interplay of intra-oral radiography, high resolution CBCT, nano-CT, hard tissue histology and EPMA can reveal the calculus-like appearance and composition of the extraradicular deposit. Calcified extraradicular deposits appear hyperechoic on ultrasound imaging and can lead to the occurrence of twinkling artefacts due to their rough mineralized surface
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
Regulatory T cells: prospective for clinical application in hematopoietic stem cell transplantation
No full textPurpose of review Regulatory T cells exert a dominant effect in controlling autoimmunity and maintaining peripheral tolerance. Regulatory T cells are also involved in preventing allograft rejection and graft versus host disease. Cellular therapy with expanded regulatory T cells represents a promising approach to control T-cell mediated pathology. In this review we will summarize the efforts to design new methods for expanding regulatory T cells and exploit their regulatory function as cellular therapy for the treatment of graft versus host disease after hematopoietic stem cell transplantation.
Recent findings Among CD4+ T cells, the best described are the naturally occurring CD4+CD25+ regulatory T cells and type 1 regulatory T cells. Recent progress has been made in the characterization of both subsets in terms of isolation and induction, respectively. However, a clear definition of their mechanisms of action has still to be achieved.
Summary Better understanding of the mechanisms of suppression mediated by regulatory T cells might enable their use to modulate specific immune responses. Moreover, the recent development of methods allowing the ex-vivo expansion of regulatory T cells to provide sufficient number of cells for in vivo infusion, represents the first step toward the use of these cells as cellular therapy for the treatment of immunologic and hematological diseases
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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