1,720,968 research outputs found
Modulation of the expression of the FGFR2-IIIb and FGFR2-IIIc molecules in dermatofibroma
No full text[No abstract available
AKT and MAPK signaling in KGF-Treated and UVB-Exposed human epidermal cells
No full textRegulation of proliferation and differentiation in keratinocyte is a complex and dynamic process that involves activation of multiple signaling pathways triggered by different growth factors. Keratinocyte growth factor (KGF) is not only a potent mitogen, but differently from other growth factors, is a potent inducer of differentiation. The MAP kinase and AKT pathways are involved in proliferation and differentiation of many cell types including keratinocytes. We investigated here the role of KGF in modulating AKT and MAPK activity during differentiation of human keratinocytes. Our results show that the mechanisms of action of KGF are dose-dependent and that a sustained activation of the MAPK signaling cascade causes a negative regulation of AKT. We also demostrated increasing expression of KGFR substrates, such as PAK4 during keratinocyte differentiation parallel to the receptor upregulation
The clinical application of autologous bioengineered skin based on a hyaluronic acid scaffold
No full textThe aim of this work was to generate an in vitro skin substitute harbouring autologous fibroblasts, keratinocytes and melanocytes, to establish a new one-step clinical method in problems associated with skin disorders. Here we present a case of a nine-year-old girl with a congenital giant nevus treated by surgical approach, with primary co-cultures of keratinocytes, melanocytes and fibroblasts obtained from autologous skin biopsy. Generally these lesions need to be removed to avoid the risk of transformation into malignant melanoma. With this purpose we analyzed the melanocytes contained in the new skin substitute for the presence of genetic alterations correlated to increased risk for melanoma. The organotypical cultures were designed including an engineered scaffold of a non-woven mesh of hyaluronic acid (HYAFF (R) 11). This biomaterial has been previously demonstrated to be the most suitable to maintain polarity and to support the in vitro constructs. Six dermal-epidermal skin substitutes were transplanted and 14 days after surgery the re-epithelialized area was about 90%. Our results suggest that this new dermal-epidermal construct not only reduces hospitalization time and ameliorates scar retraction, but might also represent a solution for the high risk of developing a tumour derived from the original nevus. (c) 2007 Elsevier Ltd. All fights reserved
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
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
Hair Regeneration from Transected Follicles in Duplicative Surgery: Rate of Success and Cell Populations Involved
No full textBACKGROUND The use of bisected hair follicles in hair transplantation has been previously reported, but the capacity of each half to regenerate the entire hair has not been clarified. OBJECTIVE To evaluate duplicative surgery rate of success and to analyze the cell populations involved in hair regeneration. METHODS We screened 28 patients undergoing duplicative surgery. Approximately 100 hair follicles from each patient were horizontally bisected and implanted. Upper and lower portions were stained for the known epithelial stem cell markers CD200, p63, beta 1-integrin, CD34, and K19. RESULTS Similar percentages of hair regrowth after 12 months were observed when implanting the upper (72.7 +/- 70.4%) and lower (69.2 +/- 71.1%) portions. Expression of CD200, p63, and beta 1-integrin was detected in both portions, whereas K19 and CD34 stained different cell populations in the upper and lower fragment, respectively. CONCLUSION Duplicative surgery might represent a successful alternative for hair transplantation, because both portions are capable of regenerating a healthy hair. Moreover, our results suggest the possible presence of stem cells in both halves of the follicle
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