1,720,959 research outputs found
Tumor-infiltrating and circulating B cells mediate local and systemic immunomodulatory mechanisms in Glioblastoma
No full textBackground: Glioblastoma (GBM) demonstrates extensive immunomodulatory mechanisms that challenge effective therapeutic interventions. These phenomena extend well beyond the tumor microenvironment (TME) and are reflected in the circulating immunophenotype. B lymphocytes (B cells) have received limited attention in GBM studies despite their emerging importance in mediating both local and systemic immune responses. Recent findings highlight the complex regulatory interactions between B cells and other immune cell populations, including tumor-infiltrating macrophages (TAMs), myeloid-derived suppressor cells (MDSCs), and other infiltrating lymphocytes (TILs). B cells are believed to hinder the efficacy of modern immunotherapy strategies focusing on T cells. Methods: This is a focused review of available evidence regarding B cells in GBM through January 2025. Results: Peripheral blood reflects a systemically dampened immune response, with sustained lymphopenia, increased plasma cells, and dysfunctional memory B cells. The tumor immune landscape is enriched in cells of B-lineage. Subsets of poorly characterized B regulatory cells (Bregs) populate the TME, developing their phenotype due to their proximity to MDSCs, TAMs, and tumoral cells. The Bregs inhibit CD8+ T activity and may have potential prognostic significance. Conclusion: Understanding the role of B cells, how they are recruited, and their differentiation shifted towards an immunomodulatory role could inform better therapeutic strategies and unleash their full antitumoral potential in GBM
Immunomodulatory mechanisms driving tumor escape in glioblastoma: The central role of IDO and tryptophan metabolism in local and systemic immunotolerance
No full textBackground: Glioblastoma (GBM) is the most aggressive primary brain tumor exhibiting extensive immune evasion mechanisms that hinder effective therapeutic interventions. This narrative review explores the immunomodulatory pathways contributing to tumor escape in GBM, specifically focusing on the role of Tryptophan (TRP) metabolism and its downstream mediators Tryptophan metabolism through the kynurenine pathway (KP) is initiated by indoleamine 2,3-dioxygenase (IDO) and tryptophan-2,3-dioxygenase (TDO2) enzymes and serves as a crucial mechanism for promoting an immunosuppressive microenvironments and systemic immunotolerance. Emerging evidence also indicates a non-enzymatic role for IDO1 signaling in these processes. The downstream effectors interact with immune cells, inducing local immunosuppression within the tumor microenvironment and altering peripheral immune responses. Methods: We systematically reviewed databases (MEDLINE via PubMed, Science Direct, and Embase) through October 2024 to highlight the interplay between local immune escape mechanisms and circulating immunotolerance, emphasizing the role of TRP metabolic enzymes in supporting GBM progression. Results: The literature review identified 99 records. TRP-related mechanisms play a central role in fostering immunotolerance in GBM. These phenomena involve intricate interactions between the infiltrating and circulating myeloid and lymphoid compartments, ultimately shaping a tolerant, pro-tumoral environment and the peripheral immunophenotype. Conclusions: The biological activity of IDO1 and TRP metabolites positions these compounds as potential markers of disease activity and promising molecular targets for future therapeutic approaches
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Tumors of the Thalamus and Basal Ganglia
No full textBasal ganglia tumors (BGT) include tumors arising from the thalamus, nucleus caudatus and lenticularis. Histopathologically, they are mostly of glial origin with a prevalence of astrocytomas. Primary BGT represent 1–5% of intracranial neoplasms in adults and 5–15% in children. As they grow, they infiltrate the normal gray-matter nuclei and white matter tracts and spread downward the brainstem, causing neurological deterioration (cognitive, sensitive and motor deficit, upper cranial nerves palsies, seizures) and obstructive hydrocephalus. Surgery is the treatment of choice for unilateral low-grade glial tumors and plays a role combined with adjuvant treatment in high-grade cases. Surgical morbidity has been significantly reduced after the introduction of advanced imaging and portal systems. Biopsy, followed by adjuvant treatment, is indicated if gross total resection (GTR) is not feasible. We present our experience of 16 patients with basal ganglia tumors treated at our institution between 2008 and 2021. These tumors were preferentially treated using a transcortical transtubular (portal system) approach, with GTR achieved in 75% of cases. Most of the patients received adjuvant treatment. At last follow-up (mean 24.6 months), we observed a 24.9-month OS. Surviving patients showed a good performance status with only one case of severe disability
Variations on the Author
Get PDF“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
Get PDFWe 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
Craniopharyngiomas
No full textCraniopharyngiomas (CFGs) are rare, benign, extra-axial tumors of epithelial origin. They arise from the suprasellar region and involve the hypothalamic-pituitary axis, the optic pathways, the ventricular system, and the major intracranial blood vessels. Histopathologically, CFGs are divided into adamantinomatous (most common) and papillary subtypes. According to the site of origin and the growth direction, they may present with neuro-ophthalmological deficits, pituitary endocrinopathies, and mass effect on critical structures. Radical surgical removal via transcranial or transsphenoidal approach is the gold-standard treatment. When gross total removal (GTR) is not achievable, adjuvant radiation therapy through conventional radiotherapy (RT) or stereotactic radiosurgery (SRS) is employed to reduce recurrence risk. We present the results of our institutional experience of 196 patients treated between 2008 and 2021. According to lesion size, location, and relation to visual apparatus and critical vessels, a transcranial (54%) or a trans naso-sphenoidal (TNS) approach (39%) was advised. Gross-total resection was achieved in 80% of cases; otherwise, adjuvant SRS was employed. Postoperative endocrinopathies were mostly transient and easily treatable and a 12.8% rate of worsening of pre-existent visual deficit or visual disturbances of new onset was observed. At a mean 7-year follow-up, we have achieved a 95% OS and 85% recurrence-free survival
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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