1,721,031 research outputs found
Glucosamine affects intracellular signalling through inhibition of mitogen-activated protein kinase phosphorylation in human chondrocytes
Full text linkThe aim of this study was to determine the effects of glucosamine on matrix metalloprotease (MMP) production, on mitogen-activated protein kinase (MAPK) phosphorylation, and on activator protein (AP)-1 transcription factor activation in human chondrocytes. The human immortalized cell line lbpva55 and healthy human chondrocytes (obtained from healthy donors) were subjected to challenge with 10 ng/ml IL-1β after pretreatment with 2.5 or 10 mmol/l glucosamine. MMP mRNA expression levels were evaluated using quantitative real-time PCR, and MMP protein production levels were evaluated in the culture supernatant using ELISA. MAPK phosphorylation was evaluated using Western blotting. AP-1 transcription factor activation was evaluated by measuring AP-1 DNA-binding activity. After IL-1β stimulation, levels of MMP-1, MMP-3 and MMP-13 production were markedly increased. Treatment with 2.5 and 10 mmol/l glucosamine reduced expression of these metalloproteases. MMP expression is regulated by transcription factors such as the AP-1 complex, which is activated by phosphorylated MAPKs. IL-1β stimulated phosphorylation of c jun amino-terminal kinase, p38 MAPK and extracellular signal regulated kinase-1/2. Glucosamine inhibited c-jun amino terminal kinase and p38 phosphorylation, and consequently c jun binding activity. These findings demonstrate, for the first time, that glucosamine inhibits IL-1β-stimulated MMP production in human chondrocytes by affecting MAPK phosphorylation
Bipolar fresh osteochondral allograft for the treatment of glenohumeral post-traumatic arthritis
No full textPurpose: Surgical management of end-stage glenohumeral osteoarthritis represents a challenge in young patients. Bipolar fresh osteochondral allograft (BFOA) represents a fascinating option to prosthetic substitution. Aim of this report is to describe an original technique for BFOA implantation in the shoulder and to describe the clinical and histological results at 30-month follow-up. Methods: A 47-year-old man received BFOA of the shoulder. Clinical and radiographical evaluations were carried out periodically up to 30 months. Results: The clinical score increased from 40 to 78 points (Constant Score), decreased from 64 points to 10 (DASH Disability/Symptom Score) and from 94 points to 0 (DASH Work module Score). Radiographically arthritis and partial reabsorption of the implanted surfaces were evident. Conclusions: The clinical result obtained in this patient seems to support the applicability of BFOA in the shoulder with severe post-traumatic arthritis and with intact rotator cuff. Although unrelated to the clinical result, the occurrence of arthritis of the implanted surfaces is cause of concern. Level of evidence: Case report, Level V
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
Novel procedure to design 3D printed composite scaffolds for trabecular bone regeneration
No full textVariations 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
COVID-19 Impact on Musculoskeletal Regenerative Medicine Research: Maintaining Lab Continuity
No full textBackground: Research in the fields of musculoskeletal tissue engineering and regenerative medicine may suffer a slowdown during the ongoing COVID-19 pandemic emergency. This is likely to harm the development of new therapeutic strategies and their translation into the clinic in the long term. Recently, the need to maintain continuity in research activities in those fields has assumed even greater importance due to the accumulation of data concerning the effects of SARS-CoV-2 on the musculoskeletal system. This study is aimed at the identification of a series of safe handling practices against COVID-19 diffusion to apply in a research environment, thus allowing the maintenance of research lab activities. Methods: The control measures to apply to mitigate the COVID-19 risk were identified and categorized utilizing the Hierarchy of Controls. We also compared our analysis with that assessed before the pandemic to consider the additional risk of COVID-19. Results: Results highlighted that the most relevant implemented measures to control SARS-CoV-2 were based on protecting people through engineering (e.g., ventilation and social distancing), and administrative (e.g., hand sanitization, work shifts) measures or Personnel Protective Equipment, rather than eliminating hazards at the source (e.g., smart working). Conclusions: Work continuity in research labs during the COVID-19 emergency should be guaranteed by ensuring the protection of researchers in the workplace and considering the physical environment, the type of operators and work activity, and the proven ability of workers to face biological risks. The increased knowledge and awareness on lab’ risks should be useful to prevent and mitigate future viral outbreaks
Host Environment: Scaffolds and Signaling (Tissue Engineering) Articular Cartilage Regeneration: Cells, Scaffolds, and Growth Factors
No full textDispelling 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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