1,721,356 research outputs found
Osteosarcopenia in hip fracture: taking cues from pathophysiology for clinical practice
No full text: Hip fractures are common in older and frail adults, and the risk of adverse outcomes and mortality is significantly increased in patients affected by osteosarcopenia. Identifying particularly vulnerable subjects is a critical step to act aimed at promoting postoperative recovery and reducing the risk of adverse events. However, the diagnostic criteria that are currently used to establish the severity of osteosarcopenia are not easily applicable in patients with hip fractures and impaired mobility. In this review, the new knowledge on the pathophysiology of osteosarcopenia that provides several cues for studying biomarkers potentially useful in clinical practice is summarized. Although significant progress has been obtained in understanding the biological mechanisms leading to the involution of the bone- muscle unit, further studies are needed to identify clinically relevant biomarkers and their diagnostic accuracy in establishing the severity of the osteosarcopenia, predicting adverse outcomes, and guiding physicians in choosing appropriate therapeutic interventions
The Emerging Roles of Extracellular Vesicles in Osteosarcoma
Full text linkExtracellular vesicles (EVs) are heterogeneous nanosized vesicles that are constitutively released by virtually all types of cells. They have been isolated in almost all body fluids. EVs cargo consists of various molecules (nucleic acids, proteins, lipids, and metabolites), that can be found on EVs surface and/or in their lumen. EVs structure confer stability and allow the transfer of their cargo to specific cell types over a distance. EVs play a critical role in intercellular communication in physiological and pathological settings. The broadening of knowledge on EVs improved our comprehension of cancer biology as far as tumor development, growth, metastasis, chemoresistance, and treatment are concerned. Increasing evidences suggest that EVs have a significant role in osteosarcoma (OS) development, progression, and metastatic process. The modulation of inflammatory communication pathways by EVs plays a critical role in OS and in other bone-related pathological conditions such as osteoarthritis and rheumatoid arthritis. In this review we describe the emerging data on the role of extracellular vesicles in osteosarcoma and discuss the effects and function of OS-derived EVs focusing on their future applicability in clinical practice
New advances in the study of bone tumors: A lesson from the 3D environment
Full text linkBone primary tumors, such as osteosarcoma, are highly aggressive pediatric tumors that in 30% of the cases develop lung metastasis and are characterized by poor prognosis. Bone is also the third most common metastatic site in patients with advanced cancer and once tumor cells become homed to the skeleton, the disease is usually considered incurable, and treatment is only palliative. Bone sarcoma and bone metastasis share the same tissue microenvironment and niches. 3D cultures represent a new promising approach for the study of interactions between tumor cells and other cellular or acellular components of the tumor microenvironment (i.e., fibroblasts, mesenchymal stem cells, bone ECM). Indeed, 3D models can mimic physiological interactions that are crucial to modulate response to soluble paracrine factors, tumor drug resistance and aggressiveness and, in all, these innovative models might be able of bypassing the use of animal-based preclinical cancer models. To date, both static and dynamic 3D cell culture models have been shown to be particularly suited for screening of anticancer agents and might provide accurate information, translating in vitro cell cultures into precision medicine. In this mini-review, we will summarize the current state-of-the-art in the field of bone tumors, both primary and metastatic, illustrating the different methods and techniques employed to realize 3D cell culture systems and new results achieved in a field that paves the way toward personalized medicine
Deproteinized bovine bone in periodontal and implant surgery
No full textObjectives: To review the histological and clinical outcomes of deproteinized bovine bone in different procedures: periodontal regeneration, socket preservation, peri-implant reconstruction and alveolar bone augmentation. Methods: Histological animal studies and clinical trials on humans regarding the performances of a bone substitute of natural origin, deproteinized bovine bone, have been evaluated. Different procedures have been examined separately. Results: Osteoconductive properties of the material are accepted by the majority of authors. In periodontal regeneration deproteinized bovine bone seems to be effective with or without barrier membranes in favorable containing defects, resulting in histological evidence of periodontal regeneration, with a prevalence of bone repair. Although some reports describe a lower reduction in socket height and width with various techniques and the grafting of deproteinized bovine bone, there is no evidence to recommend socket filling or manipulation to preserve its dimensions. Peri-implant reconstruction and alveolar ridge augmentation utilizing deproteinized bovine bone are supported by favorable reports but these procedures are affected by a significant amount of adverse events that may jeopardize the success of the treatment. Significance: Deproteinized bovine bone possesses osteoconductive properties that may improve bone regeneration of favorable containing periodontal defects. No evidence supports socket filling and peri-implant reconstruction. © 2010 Academy of Dental Materials
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
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