1,720,959 research outputs found
Platelet-rich plasma: why intra-articular? A systematic review of preclinical studies and clinical evidence on PRP for joint degeneration.
No full textPURPOSE:
The aim of this review was to analyze the available evidence on the clinical application of this biological approach for the injective treatment of cartilage lesions and joint degeneration, together with preclinical studies to support the rationale for the use of platelet concentrates, to shed some light and give indications on what to treat and what to expect from intra-articular injections of platelet-rich plasma (PRP).
METHODS:
All in vitro, in vivo preclinical and clinical studies on PRP injective treatment in the English language concerning the effect of PRP on cartilage, synovial tissue, menisci, and mesenchymal stem cells were considered. A systematic review on the PubMed database was performed using the following words: (platelet-rich plasma or PRP or platelet concentrate or platelet lysate or platelet supernatant) and (cartilage or chondrocytes or synoviocytes or menisci or mesenchymal stem cells).
RESULTS:
Fifty-nine articles met the inclusion criteria: 26 were in vitro, 9 were in vivo, 2 were both in vivo and in vitro, and 22 were clinical studies. The analysis showed an increasing number of published studies over time. Preclinical evidence supports the use of PRP injections that might promote a favourable environment for joint tissues healing. Only a few high-quality clinical trials have been published, which showed a clinical improvement limited over time and mainly documented in younger patients not affected by advanced knee degeneration.
CONCLUSIONS:
Besides the limits and sometimes controversial findings, the preclinical literature shows an overall support toward this PRP application. An intra-articular injection does not just target cartilage; instead, PRP might influence the entire joint environment, leading to a short-term clinical improvement. Many biological variables might influence the clinical outcome and have to be studied to optimize PRP injective treatment of cartilage degeneration and osteoarthritis
Utilizzo del PRP nel trattamento della patologia degenerativa cartilaginea
No full textPiastrine e Platelet Rich Plasma: i fattori di crescita (G.F.) sono un particolare gruppo di polipeptidi che ha la proprietà di regolare lo sviluppo dei vari tessuti. Le piastrine contengono numerosi di questi fattori. I G.F. sono variamente implicate nell'omeostasi tissutale cartilaginea e delle strutture articolare in toto, contribuendo, grazie alla loro mutua interazione, a: aumentare l'espressione e la prolifferazione di cellule del fenotipo condrale; stimolare la differenziazione di cellule staminali mesenchimali in senso condrogenico; propuovere la deposizione di matrice e rallentare il catabolismo della stessa; diminuire l'effetto soppressivo sulla sintesi di proteoglicani da parte di mediatori infiammatori quali l'IL1.
Il fatto che le piastrine secernano fattori di crescita e numerose altre molecole utili per i processi riparativi è la premessa per il loro utilizzo in clinica, al fine di influenzare la rigenerazione tissutale ed accelerare la guarigione.
Il Platelet Rich Plasma, plasma arricchito in piastrine, comunemente indicato con l'acronimo P.R.P., è un concentrato di piastrine e quindi di fattori di crescita autologhi e di molte altre molecole bioattive.
Il razionale biologico dell'impiego del P.R.P. nella patologia articolare degenerativa risiede in un duplice movente: ottenere una concentrazione locale di fattori di crescita capaci di determinare uno stimolo biologico positivo per l'omeostasi cartilaginea; e promuovere la formazione di un supporto adesivo (gel piastrinico) che permette di confinare la loro secrezione nel sito prescelto
ACI di II generazione
No full textLe tecniche ACI cosiddette “di II generazione” sono state sviluppate con l’obiettivo di superare i limiti della tecnica ACI tradizionale grazie all’impiego di tessuti bioingegnerizzati di vario genere sotto forma di scaffold solido (Fig. 1), in grado di fornire un supporto biocompatibile e biodegradabile capace di mantenere il fenotipo differenziato dei condrociti e permetterne una maggior adesione al sito di impianto. Inoltre alcuni di questi supporti permettono la possibilità di utilizzare tecniche artroscopiche, diminuendo tempi e morbidità della procedura chirurgica; rimangono però limitate le conoscenze sulla stabilità a lungo termine di alcuni di questi impianti
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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