1,721,032 research outputs found
Collagen fibrils in human tendons, is everything already said? A qualitative ultrastructural assessment
No full textImproving structural knowledge of human tendons
is fundamental for a better understanding of pathological
and regenerative processes occurring in these key
structures. Recent advances in tendon biology indicate
cellular heterogeneity between tendons of different muscles.
In contrast, very little is known about potential differences
in extracellular matrix in tendons across anatomy.
In the present work, we aimed to assess collagen
fibril organisation ultrastructurally in human supraspinatus,
semitendinosus, and quadriceps tendons, as well
as in the anterior cruciate and patellar ligaments. Samples
were obtained with appropriate permissions from
seven different donors belonging to the Anatomy Gift
Programme of the Royal College of Surgeons in Ireland
in Dublin, that had been previously embalmed for routine
anatomical examination.
Samples from the tendon mid-body were harvested
and processed for Transmission Electron Microscopy
(TEM).
We examined a total of 34 tendons (n=2 samples of
each). Collagen fibrils were well recognisable in 32 tendons.
O
verall, marked heterogeneity between samples
from the same tendon type of different donors, or
between the various tendons of the same donor, was
observed in terms of collagen fibril shape (rounded
vs more irregular-polygonal), size distribution, and
width. The greatest similarity in fibril organisation was
observed between patellar ligament and quadriceps tendon.
The anterior cruciate ligament showed smaller,
less rounded fibrils, which were more consistent in size.
Supraspinatus also showed bundles perpendicular to the
longitudinal tendon axis. Consistency in fibril organisation
between both samples of the same individual tendon
was observed in 26 cases.
This study demonstrates that ultrastructural analysis
of collagen fibril is feasible in tissue from anatomical
donors despite the embalming process not being
a standard procedure of fixation for TEM examination.
This first description also offers a basis for a more
detailed and quantitative assessment of the collagen
fibrils in human tendons.
References
1) Franchi, Marco, Trirè, Alessandra, Quaranta, Marilisa,
Orsini, Ester, Ottani, Victoria. Collagen Structure
of Tendon Relates to Function. The Scientific World
Journal, 2007, 7, 132725.
2) Christopher K. Revell, Oliver E. Jensen, Tom Shearer,
Yinhui Lu, David F. Holmes, Karl E. Kadler. Collagen
fibril assembly: New approaches to unanswered questions.
Matrix Biology Plus, 2021, 12, 100079.
3) Baldwin M, Buckley CD, Guilak F, Hulley P, Cribbs
AP, Snelling S. A roadmap for delivering a human
musculoskeletal cell atlas. Nat Rev Rheumatol. 2023
19, 738-752
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Evaluation of a novel biomarker as a predictor of response, stratification tool, and measure of pharmacology for a disease-modifying osteoarthritis therapeutic
Get PDFIntroduction Osteoarthritis (OA) is a leading cause of disability in developed countries and is independently associated with increased mortality. Aggrecan degradation is an early process in OA-related cartilage degradation, principally attributed to activity of the aggrecanase ADAMTS-5. One of the products of this activity is ARGS neoepitope which is proposed as a biomarker of OA disease burden. Biomarker measurement and correlation could advance research into effective intervention in OA. In this study we aim to assess ARGS neoepitope as a marker of OA disease burden through correlation with MRI-derived imaging outcome measures. We also assess an ADAMTS5-specific monoclonal antibody for its viability as an OA pharmaceutical intervention. Methodology This study is a cross-sectional cohort study of 95 knee surgical patients to measure ARGS neoepitope using electrochemiluminescent assay on serum, urine and synovial fluid. Specific software was used to generate MRI-derived outcome measures such as volume and intensity measures, allowing comparison of these two outcome measures. This study also investigated ARGS neoepitope response to an ADAMTS-5 blocking monoclonal antibody in vitro in a human explant model. Results A significantly higher level of ARGS neoepitope was found in urine samples (1.58-fold, P = 0.006) of patients with late compared to early disease, whilst no significant differences in neoepitope values were detected in synovial fluid and serum samples. With regard to disease burden, ARGS neoepitope was correlated with medial compartment cartilage loss in medial unicompartmental knee replacement patients (R2 = 0.249; P = 0.012) however in general it was not strongly related to imaging markers. In the in vitro work the ADAMTS-5 specific monoclonal antibody produced a dose-dependent reduction in ARGS neoepitope released from cartilage explants. Compared to the isotype control the mean reduction of ARGS neoepitope at 12 days was 43.6% (P < 0.001). Discussion The relationship between serological biomarkers of OA and disease burden remains complex. ARGS neoepitope may reflect enzymatic turnover of cartilage within the joint but the relationship with OA disease burden cannot be fully established by this study. Many factors including physical activity, disease status in other joints and patient muscle mass, could cause single time-point results to become less reliable and impact on the findings of both this and all OA biomarker studies. Conclusion This study demonstrates that ARGS neoepitope shows some promise as an OA biomarker and provides important information on conducting future studies assessing this and other biomarkers in OA
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