1,720,985 research outputs found
Loss of expression of the oncosuppressor PTEN in thyroid incidentalomas associates with GLUT1 plasmamembrane expression
No full textAIM: Molecular imaging diagnosis with FDG-PET ((18)F-fluorodeoxyglucose positron emission tomography with computed tomography) can reveal the presence of un-suspected thyroid cancer that are referred to as "incidentaloma" because of the incidental finding. The glucose analogue (18)FDG is internalized in the cells by glucose transporters belonging to the GLUTs family. The surface expression of GLUT is under the control of the PI3k/Akt pathway. PTEN is an oncosuppressor frequently mutated or deleted in thyroid cancers. The lipid phosphatase activity of wild type PTEN switches off the Akt pathway. Here we tested the hypothesis that PTEN expression might affect the surface expression of GLUT1 and therefore influence the possibility of "incidental" detection of thyroid cancer based on FDG-PET.
METHODS:
The biopsy of 8 patients, who were incidentally diagnosed with PTC by (18)F-fluorodeoxyglucose positron emission tomography with computed tomography, was assayed by immunofluorescence for the co-expression of the PTEN oncosuppressor and of GLUT1.
RESULTS:
Loss of PTEN expression was detected in the majority of investigated cases (N.=6/8). Strikingly, while the two PTEN positive cases were negative for GLUT1 expression, the PTEN negative cases showed intense expression of GLUT1 at the cell surface.
CONCLUSION:
The present observations, though made in a limited number of cases, suggest that PTEN negative thyroid cancers have high chances to be revealed as incidentalomas at FDG-PET
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
Identification of overexpressed genes in malignant pleural mesothelioma
Full text linkMalignant pleural mesothelioma (MPM) is a fatal tumor lacking effective therapies. The characterization of overexpressed genes could constitute a strategy for identifying drivers of tumor progression as targets for novel therapies. Thus, we performed an integrated gene‐expression analysis on RNAseq data of 85 MPM patients from TCGA dataset and reference samples from the GEO. The gene list was further refined by using published studies, a functional enrichment analysis, and the correlation between expression and patients’ overall survival. Three molecular signatures defined by 15 genes were detected. Seven genes were involved in cell adhesion and extracellular matrix organization, with the others in control of the mitotic cell division or apoptosis inhibition. Using Western blot analyses, we found that ADAMTS1, PODXL, CIT, KIF23, MAD2L1, TNNT1, and TRAF2 were overexpressed in a limited number of cell lines. On the other hand, interestingly, CTHRC1, E‐selectin, SPARC, UHRF1, PRSS23, BAG2, and MDK were abundantly expressed in over 50% of the six MPM cell lines analyzed. Thus, these proteins are candidates as drivers for sustaining the tumorigenic process. More studies with small‐molecule inhibitors or silencing RNAs are fully justified and need to be undertaken to better evaluate the cancer‐driving role of the targets herewith identified
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
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
Clinical and molecular studies in two new cases of ARSACS
No full textAutosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is an early-onset neurodevelopmental disorder characterized by the association of spastic ataxia and sensorimotor neuropathy. Additional features include retinal changes and cognitive impairment. Today, next-generation sequencing (NGS) techniques are allowing the rapid identification of a growing number of missense variants, even in less typical forms of the disease, but the pathogenic significance of these changes is often difficult to establish on the basis of classic bioinformatics criteria and genotype/phenotype correlations. Herein, we describe two novel cases of missense mutations in SACS. The two individuals were identified during the genetic screening of a large cohort of patients with inherited ataxias. We discuss how protein studies and specialized ophthalmological investigations could represent useful pointers for the interpretation of genetic data. Combination of these tools with NGS for rapid genotyping might help to identify new true ARSACS cases
PTEN deficiency and mutant p53 confer glucose-addiction to thyroid cancer cells: impact of glucose depletion on cell proliferation, cell survival, autophagy and cell migration
No full textProliferating cancer cells oxidize glucose through the glycolytic pathway. Since this metabolism is less profitable in terms of ATP production, cancer cells consume large quantity of glucose, and those that experience insufficient blood supply become glucose-addicted. We have analyzed the response to glucose depletion in WRO and FTC133 follicular thyroid cancer cells, which differ in the expression of two key regulators of the glucose metabolism. WRO cells, which express wild type p53 and PTEN, showed a higher rate of cell proliferation and were much less sensitive to glucose-depletion than FTC133 cells, which are PTEN null and express mutant p53. Glucose depletion slowed-down the autophagy flux in FTC133 cells, not in WRO cells. In a wound-healing assay, WRO cells were shown to migrate faster than FTC133 cells. Glucose depletion slowed down the cell migration rate, and these effects were more evident in FTC133 cells. Genetic silencing of either wild-type PTEN or p53 in WRO cells resulted in increased uptake of glucose, whereas the ectopic expression of PTEN in FTC133 cells resulted in diminished glucose uptake. In conclusion, compared to WRO, FTC133 cells were higher glucose up-taker and consumer. These data do not support the general contention that cancer cells lacking PTEN or expressing the mutant p53R273H are more aggressive and prone to better face glucose depletion. We propose that concurrent PTEN deficiency and mutant p53 leads to a glucoseaddiction state that renders the cancer cell more sensitive to glucose restriction. The present observation substantiates the view that glucose-restriction may be an adjuvant strategy to combat these tumours
- …
