1,720,996 research outputs found
Classification of human meningiomas: lights, shadows, and future perspectives
No full textMeningiomas represent the most common primary tumors of the central nervous system (CNS) in adulthood. They are currently classified into several histotypes and into three grades of malignancy according to the criteria of the World Health Organization (WHO) classification of tumors of the CNS. WHO histological grade is currently the most significant morphological predictor of recurrence risk of meningiomas. For this reason, it is fully taken into consideration in postsurgical therapeutic decision making in patients with meningioma. However, the main drawback of the WHO grading system system is that criteria for its assessment are rather subjective and poorly standardized. Hence, additional factors are warranted to predict recurrence risk of meningiomas, so that patients may actually receive the most appropriate therapy. In recent years, biomolecular pathogenesis of meningiomas has been partially clarified, and many efforts have been made in the identification of molecular factors associated with recurrence risk of meningioma. Here we review WHO criteria currently used for classification of meningiomas and discuss on pitfalls and limits of grading assessment. In addition we present the latest advancement in the knowledge of biomolecular alterations involved in the pathogenesis and progression of meningiomas. Similarly to what has already happened for gliomas, a novel classification integrating histology and molecular information might overcome the limits of histological classification in terms of reproducibility as well as of prognostic and predictive relevance. © 2016 Wiley Periodicals, Inc
Rhabdoid Meningioma: Grading and Prognostic Significance of This Uncommon Variant
No full textThe clinical behavior of three cases of meningiomas with rahbdoid features but no evidence of cytological malignancy is described
Nuclear H3 K27me3 is retained in both components of dual genotype oligoastrocytoma
No full textno abstract availabl
p-CREB expression in human meningiomas: correlation with angiogenesis and recurrence risk
No full textDespite total surgical resection, a percentage of meningiomas do unexpectedly recur. At present the prediction of recurrence risk and the management of recurrent tumours represent major issues in the patients affected by meningiomas. The present study aims at investigating the prognostic value of the expression of the phosphorylated transcription factor cyclic AMP responsive element binding protein (p-CREB) in a series of meningiomas of different histotype and grade. While no p-CREB expression was found in specimens of normal leptomeninges, 71 % of meningiomas in our cohort expressed p-CREB. In addition, nuclear expression of p-CREB was present in the endothelia of tumor vessels in all of the meningiomas, but not in the vessels of the non-neoplastic meninges. High expression of p-CREB was significantly more frequent in meningiomas showing atypical, chordoid or microcystic histotype (P = 0.0003), high histological grade (P < 0.0001), high Ki-67 labeling index (P = 0.0001), high microvessel density counts (P < 0.0001) and high vascular endothelial growth factor expression (P = 0.0113). In addition, high p-CREB expression was significantly associated with the development of recurrences (P = 0.0031) and it was a significant negative, albeit not independent, prognostic factor for disease free survival in patients with meningiomas submitted to complete surgical removal (P = 0.0019). In conclusion, we showed that p-CREB is expressed in human meningiomas and that it represents a significant predictor of recurrence risk in these tumors. Due to its high expression in more aggressive tumors and in the tumor vessels, it may represent a novel therapeutic target in meningiomas
Ossified Intracranial Meningiomas: Description of the First Series of Cases and Review of the Literature
No full textMetaplastic meningiomas are characterized by mesenchymal differentiation with formation of bone, cartilage, fat, or xanthomatous elements. However the presence of extensive areas of ossification is rare in meningiomas. In addition, intracranial location of ossified meningiomas is uncommon. Surgical management represents the optimal treatment for ossified meningiomas, but ossification may interfere with surgery and condition outcome
The density of microvessels positive for Wilms' tumour-1 protein (WT-1) is an independent predictor of recurrence risk in meningiomas
No full textWilms' tumour-1 (WT-1) protein m-RNA was recently demonstrated in meningiomas, suggesting the potential application of WT-1 immunotherapy in these tumours. The aim of the present study was to analyze the immunohistochemical expression of WT-1 protein, its correlation with the clinico-pathological variables and association with vascular endothelial growth factor (VEGF) expression, in a series of 60 meningiomas of different histotype and histological grade. None of the cases expressed WT-1 in the neoplastic cells, while endothelial expression was evidenced in a variable number of tumour vessels in all the meningiomas. The density of microvessels positive for WT-1 (WT-1 MVD) was significantly higher in meningiomas showing higher histological grade (P = 0.0191), growth fraction (P = 0.0201), expression of VEGF (P = 0.0288) and recurrence risk (P = 0.022). In addition, high WT-1 MVD was a significant independent predictive factor for a shorter recurrence-free survival (RFS) in patients with completely resected meningiomas (P = 0.0028). In conclusion, this study shows that WT-1 MVD is correlated with the biological aggressiveness of meningiomas. Although no staining for WT-1 was evidenced in the neoplastic cells of these tumours, WT-1 endothelial expression in the tumour vessels might represent a target for WT-1 immunotherapy in the aim of reducing their blood supply and growth
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
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