1,720,994 research outputs found
Approaching the histodynamics of celiac disease in modern times : the need of going beyond the dogmas
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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
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
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
Paclitaxel-dependent prolonged and persistent remission four years from first recurrence of secondary breast angiosarcoma
No full textAmong angiosarcomas, radiation-induced breast sarcomas (RIBS) represent a well-known entity generally characterized by a poor outcome, especially in patients with advanced disease. Despite the unfavorable prognosis, some chemotherapeutic agents have been used to treat these malignancies, occasionally with success. Treatments with demonstrated activity against sarcomas include ifosfamide-based regimens and, more recently, taxane derivatives. We report a case of a patient having a secondary breast angiosarcoma recurring early after surgery, who achieved complete remission following treatment with weekly paclitaxel. After 4 years of maintenance therapy, with an interval between consecutive administrations of no longer than 3 weeks, the patient is still in complete remission. A locoregional recurrence was documented twice during this period, the first as a consequence of a brief treatment interruption and the second because of a treatment delay. Nonetheless, in both instances a new complete remission was rapidly achieved with the resumption of the same treatment, without evidence of any significant adverse effects. We discuss the highly unusual behavior of this malignancy and the possible role of the two different mechanisms of action of paclitaxel-antiangiogenic versus cytotoxic-depending on the schedule of administration, with evidence of "false" drug-resistance
PTEN immunohistochemistry is a predictor of mismatch repair status in breast cancer
Get PDFAbstract
Phosphatase and tensin homolog (PTEN), a potent downregulator of the PI3K-Akt pathway, has been shown to mediate the interaction between poly (ADP-ribose) polymerases (PARPs) and the mismatch repair (MMR) complex in endometrial and ovarian cancer. Drugs inhibiting PARPs (iPARPs) are currently considered promising therapeutic tools in a subset of PTEN-defective tumors. Regrettably, the frequency and significance of MMR alterations in breast cancer is debated, and their relationship with PTEN status has not been investigated in the breast. Furthermore, many of the studies on the DNA damage response and its therapeutic implications in breast cancer focus on inherited syndromes (e.g. Lynch syndrome and hereditary breast-ovarian cancer syndrome).
Aims: We sought to explore the interplay between PTEN and the MMR system and to define whether PTEN immunohistochemistry (IHC) is a predictor of MMR proficiency in non-familial breast cancers.
Methods: 373 cases of non-familial breast cancers, including a representative number of no special (n=295) and special types (n=78), carefully characterized from clinical and pathological standpoints, were reviewed and used to construct 14 tissue microarrays (TMAs). For each case, a mean of 4.5 tumor tissue cores (range 3 to 6 cores) was sampled, incorporating distinct topographic areas of the tumor, as well as matched non-neoplastic breast tissue. Taken together, 1876 spots were generated. Each TMA was subjected to IHC for PTEN and the DNA MMR proteins MLH1, MSH2, MSH6 and PMS2. In order to minimize human-related biases, each stained slide was digitalized and two pathologists blindly analyzed each tumor spot using a dedicated software able to segment and randomize TMA cores. The pattern of expression was therefore annotated manually on a digital database using a specific add-on module to reconstruct the original topography.
Results: According to clinicopathologic surrogate definition of intrinsic subtypes, PTEN protein loss or heterogeneous expression was more frequent in estrogen receptor negative cancers. Furthermore, 100% of the MMR-proficient luminal B-like (HER2+) and triple-negative breast cancers displayed strong and diffuse homogeneous PTEN expression, while PTEN-positive status identified MMR-proficient luminal A-like and luminal B (HER2-) like tumors with accuracy rates of 89.3% and 92.7%, respectively (p=0.001, Fisher's exact test).
Conclusions: The present study is the first to investigate PTEN protein loss in a large set of non-familial breast carcinomas based on their DNA MMR status by IHC. Here, we demonstrated that PTEN strong and homogeneous expression by IHC is able to capture the vast majority of MMR-proficient non-familial breast cancers. Our findings broaden the understanding of the biology underpinning these tumors, suggesting that PTEN is likely play a role in the development of MMR alterations. Given that PTEN-defective breast cancers have the propensity to develop additional somatic alterations in the MMR system, our results suggest that IHC for PTEN and MMR proteins may be emplyed as an ancillary study to define new subclasses of sporadic breast cancers potentially eligible for iPARPs therapies.
Citation Format: Fusco N, Gambini D, Runza L, Lopez G, Ercoli G, Despini L, Bosari S. PTEN immunohistochemistry is a predictor of mismatch repair status in breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-06-07.</jats:p
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