1,721,009 research outputs found
IDENTIFICATION OF THREE DISTINCT SUBGROUPS OF B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA BASED UPON MUTATIONS OF BCL-6 AND IgV GENES
No full textAlthough B cell chronic lymphocytic leukemia (B-CLL) has been traditionally viewed as a tumor of virgin B cells, this notion has been recently questioned by data suggesting that a fraction of B-CLL derives from antigen experienced B cells. In order to further clarify the histogenetic derivation of this lymphoproliferation, we have analyzed the DNA sequences of the 5' non-coding region of BCL-6 proto-oncogene in 28 cases of B-CLL. Mutations of BCL-6 proto-oncogene, a zinc finger transcription factor implicated in lymphoma development, represent a histogenetic marker of B cell transit through the germinal center (GC) and occur frequently in B cell malignancies derived from GC or post-GC B cells. For comparison, the same tumor panel was analyzed for somatic mutations of the rearranged immunoglobulin variable (IgV) genes, which are known to be acquired at the time of B cell transit through the GC. Sequence analyses of BCL-6 and IgV genes allowed the definition of three groups of B-CLL. Group I B-CLL displayed mutations of both BCL-6 and IgV genes (10/28; 36%). Group II B-CLL displayed mutated IgV genes, but a germline BCL-6 gene (5/28; 18%). Finally, group III B-CLL included the remaining cases (13/28; 46%) that were characterized by the absence of somatic mutations of both BCL-6 and IgV genes. Overall, the distribution of BCL-6 and IgV mutations in B-CLL reinforce the notion that this leukemia is histogenetically heterogeneous and that a substantial subgroup of these lymphoproliferations derives from post-germinal center B cells
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
Interleukin-10 and transforming growth factor-beta1 in cord blood: relationship with paternal allergy and cesarean section
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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
Increased Interleukin-10 in childhood Helicobacter pylori infection could be involved in the mechanism protecting from allergy
No full textIdentification of three subgroups of B-CELL chronic lymphocytic leukemia based upon mutations of BCL-6 and Ig V genes
No full textMOLECULAR CHARACTERIZATION OF COMMON VARIABLE IMMUNODEFICIENCY-RELATED LYMPHOMAS
No full textCommon variable immunodeficiency (CVI) patients are at high relative risk of developing non-Hodgkin lymphomas (NHL), mainly represented by B-lineage diffuse large cell lymphomas. The molecular pathogenesis and histogenesis of CVI-related NHL are poorly understood. We have thus attempted to provide a detailed molecular characterization of their histogenesis and pathogenesis. A panel of 5 CVI-related NHL was subjected to detailed analysis of histogenetic markers (mutations of immunoglobulin variable heavy chain-IgVH and of BCL-6 genes) acquired by B-cells at the time of germinal center transit. Somatic hypermutation of IgVH and BCL-6 genes occurred in 5/5 cases; in all cases, mutations were stable with no evidence of ongoing mutation processes. In 3/5 cases, the pattern of IgVH mutations was consistent with selection and stimulation of the tumor clone by antigen. To further clarify the pathogenesis, samples were tested for inactivation by promoter hypermethylation of the genes 0(6)-methylguanine-DNA-methyltransferase (MGMT) and glutathione S-transferase (GST) p1, which code for detoxifying enzymes, as well as of death-associated protein (DAP)-kinase, coding for a proapoptotic molecule. Promoter hypermethylation of MGMT, GSTp1 and DAP-kinase was detected in 2/5, 3/5 and 3/5 CVI-related NHL, respectively. Overall, these data indicate that: i) similarly to other immunodeficiency-related NHL, CVI-related NHL derive from germinal center-related B-cells, namely centrocytes or post-germinal center B-cells; ii) antigen stimulation and selection are involved in the development of at least a fraction of these cases; iii) hypermethylation of the MGMT, DAP-kinase and GSTp1 genes occurs at sustained frequencies in CVI-related NHL and may provide novel prognostic markers and therapeutic targets for the clinical management of these lymphomas
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