1,720,984 research outputs found
Sellar metastasis from clear cell sarcoma: Description of the first case
No full textMetastases to the sellar region and pituitary gland are rare and usually occur in advanced cancers, commonly breast and lung adenocarcinomas. Metastases from sarcomas to the pituitary gland are extremely rare. Here, we report the case of a 52-year-old man who had undergone surgery and radiotherapy for a clear cell sarcoma (CCS) of the knee at age of 42. The patient underwent resection of 2 distinct metastatic lung nodules 9 years later. During follow-up, he developed a persistent headache and diabetes insipidus. MRI revealed a sellar and suprasellar lesion, which was removed with an endoscopic trans-sphenoidal approach. Histopathology was consistent with CSS metastasis. At 2-year follow-up, there was no evidence of local recurrence in the sella, while a single brain metastasis was documented, together with other deposits in the paravertebral and pelvic muscles. CCS is a rare, aggressive neoplasm usually involving the deep soft tissue of the extremities, including trunk or limb girdles, and extensive surgical removal, along with adjuvant chemo-and radiotherapy, significantly prolongs survival. Nevertheless, prognosis remains poor, mainly due to frequent local recurrences and eventually distant metastases, usually within regional lymph nodes, lung, and bone. To the best of our knowledge, this is the first description of a sellar metastasis from CCS
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
Timing of mTOR activation affects tuberous sclerosis complex neuropathology in mouse models
No full textTuberous sclerosis complex (TSC) is a dominantly inherited disease with high penetrance and morbidity, and is caused by mutations in either of two genes, TSC1 or TSC2. Most affected individuals display severe neurological manifestations - such as intractable epilepsy, mental retardation and autism - that are intimately associated with peculiar CNS lesions known as cortical tubers (CTs). The existence of a significant genotype-phenotype correlation in individuals bearing mutations in either TSC1 or TSC2 is highly controversial. Similar to observations in humans, mouse modeling has suggested that a more severe phenotype is associated with mutation in Tsc2 rather than in Tsc1. However, in these mutant mice, deletion of either gene was achieved in differentiated astrocytes. Here, we report that loss of Tsc1 expression in undifferentiated radial glia cells (RGCs) early during development yields the same phenotype detected upon deletion of Tsc2 in the same cells. Indeed, the same aberrations in cortical cytoarchitecture, hippocampal disturbances and spontaneous epilepsy that have been detected in RGC-targeted Tsc2 mutants were observed in RGC-targeted Tsc1 mutant mice. Remarkably, thorough characterization of RGC-targeted Tsc1 mutants also highlighted subventricular zone (SVZ) disturbances as well as STAT3-dependent and -independent developmental-stage-specific defects in the differentiation potential of ex-vivo-derived embryonic and postnatal neural stem cells (NSCs). As such, deletion of either Tsc1 or Tsc2 induces mostly overlapping phenotypic neuropathological features when performed early during neurogenesis, thus suggesting that the timing of mTOR activation is a key event in proper neural development
Cavin-2 is a specific marker for detection of well-differentiated liposarcoma.
No full textCaveolae are cholesterol enriched invaginations of the plasma membrane involved in a variety of processes,
including glucose and fatty acids absorption, cell transduction and mechanoprotection. The
biogenesis and function of caveolae depend on the activity of Caveolin (Cav-1, -2 and -3) and Cavin
(Cavin-1, -2, -3 and -4) protein families. Since the membrane Cavin-2 protein was reported to play a key
role in caveolae formation of adipocytes, in this work we have used a multidisciplinary approach to
investigate its expression in liposarcoma (LPS), an adipocytic soft tissue sarcoma affecting adults. Data
obtained through an in silico and immunohistochemical analysis suggest that Cavin-2, along with Cavin-
1, Cav-1 and Cav-2, is mostly expressed in the least aggressive LPS subtype, namely well-differentiated
LPS, while is almost undetectable in the more aggressive myxoid, pleomorphic and dedifferentiated
LPS tumors. Accordingly, in vitro analysis confirmed that Cavin-2 expression increases in LPS tumor cell
lines during differentiation as compared to proliferation, as detected by immunoblotting and immunofluorescence
analysis. Overall, these data suggest that Cavin-2 represents a useful marker for discriminating
the degree of differentiation in LPS tumors
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
Caveolin 1 is a marker of poor differentiation in Rhabdomyosarcoma
No full textCaveolins consist of three different membrane scaffolding proteins that play a variety of processes in different tissues. In skeletal muscle caveolins are differentially distributed, with Caveolin 1 (Cav-1) being uniquely expressed in satellite cells and Caveolin 3 (Cav-3) in mature myofibers. Rhabdomyosarcoma (RMS) represents the most common childhood soft-tissue sarcoma arising from mesenchimal precursors which fail to undergo proper commitment to muscle lineage. Cav-3 has been proposed as a marker of RMS with a high degree of differentiation, while biological significance of Cav-1 expression in RMS is still a matter of debate. In the present study we show that Cav-1 is predominantly expressed in the embryonal RMS histotype, as further confirmed by transcript and protein analysis in different in vitro human RMS cell lines. Immature cell phenotype of human embryonal RD line, carrying spontaneous activating RAS mutations, was significantly associated to ERK MAPK signalling pathway and featured by high Cav-1 levels, whereas pharmacological attenuation of the ERK pathway, improving cell differentiation, lead to Cav-1 down-regulation. Overall, these data place Cav-1 as a valuable marker of diagnosis for RMS characterised by low degree of differentiation
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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