1,720,967 research outputs found
Svelare l'origine specifica cellulare di Oncostatina M (OSM) nel rilascio di cellule staminali ematopoietiche (HSPCs)
No full textBackground and aims. Here, we investigate the cell-specific origin of the cytokine Oncostatin M (OSM) and its role in the release of hematopoietic stem and progenitor cells (HSPCs) into the bloodstream. HSPCs reside in the bone marrow (BM) niches, and their release is influenced by complex interactions with the nervous system, the stromal compartment of the BM, and immune cells, including those belonging to the innate immune system. The circulating levels of HSPCs exhibit a circadian oscillation in peripheral blood. Low levels of HSPCs in the blood are caused by an impaired release from the BM compartment, a condition known as "mobilopathy." This condition leads to cardiovascular complications due to reduced vascular regeneration, as well as poor outcomes in hematopoietic stem cell transplantation (HSCT) due to apheresis failure. In diabetes, myeloid cells, particularly BM macrophages, retain HSPCs in the BM by producing Oncostatin M (OSM), a cytokine that acts as a molecular brake by stimulating the production of CXCL12 by BM stromal cells.
In the present study, the main objective was to investigate the contribution of neutrophil-derived OSM in the regulation of HSPC release from BM niches into the bloodstream.
Methods and results. Transgenic mice characterized by the deletion of the Osm gene (Osm-/-) exhibited persistently elevated levels of circulating HSPCs throughout the entire day/night cycle, compared to wild-type mice. Consequently, Osm-/- mice showed reduced hematopoietic progenitor activity in the BM. In parallel, Osm-/- mice maintained the circadian oscillation of aged neutrophils without affecting BM phagocytic and neutrophil clock machinery. Furthermore, neutrophils particularly if aged (CXCR4highCD62Llow), expressed more OSM compared to other BM or peripheral blood immune cells. To understand the role of neutrophil-derived OSM, we employed adoptive transfers of aged neutrophils. Intravenous transfer of wild-type neutrophils decreased circulating HSPC levels in recipient mice, demonstrating that neutrophils play a role in the retention of BM HSPCs. This effect was not abolished when we injected Osm-/- neutrophils into wild-type mice. We then injected wild-type OSM-producing neutrophils into Osm-/- mice and quantified HSPCs in the peripheral blood. The injection of wild-type neutrophils failed to reduce HSPC levels, which remained elevated compared to wild-type mice. Thus, neutrophils producing OSM were unable to lower HSPC levels in the blood, even following neutrophil activation or when multiple neutrophils injections were performed to reach detectable OSM concentrations in the BM extracellular fluid. We demonstrated that, although neutrophils express higher levels of Osm compared to other immune cells, they are not the main source of OSM in the regulation of HSPC trafficking. To verify the specific cellular origin of HSPC-regulating OSM, we selectively depleted macrophages and neutrophils in wild-type and Osm-/- mice: the inhibitory effect of OSM on HSPC traffic was primarily due to macrophages rather than neutrophils.
Conclusion. The neutrophil transfer approach demonstrates that neutrophils may play a role in regulating HSPC trafficking, but this is not mediated by OSM, which appears to have distinct functions depending on the cell type and context of its production
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
Double versus single suture stenting to manage hypertensive spikes after glaucoma drainage device implantation
No full textPurpose: To evaluate the safety and efficacy of double compared to single intraluminal suture stenting in reducing early postoperative hypertensive spikes (HS) and hypotony after Baerveldt glaucoma implant surgery. Methods: For this retrospective study, we reviewed the medical charts of 60 patients (60 eyes) who underwent Baerveldt drainage device surgery between 2017 and 2019. Two groups were formed according to whether a single suture stent was placed within the tube (5-0 polypropylene, 30 eyes, group 1) or a double suture (5-0 and 6-0 polypropylene, 30 eyes, group 2). Intraocular pressure (IOP) was measured at baseline, at 6 h, and on postoperative days 1, 2, 5, 7, 14, 21, 30, 60, 90, 180. The occurrence of HS (IOP ⩾ 30 mmHg), anterior chamber reformation, decompressive paracentesis, anti-glaucoma medication, and adverse events were recorded. Results: There was a greater decrease in IOP from baseline at days 1, 2, and 21 (p < 0.05) and number of HS at 6 h (p = 0.006) and postoperative day 1 (p < 0.001) in group 2. The mean number of decompressive paracentesis, anterior chamber reformation procedures, and topical anti-glaucoma medications was the same in both groups; the need for oral acetazolamide was significantly lower in group 2 at days 1, 21, and 30 (p < 0.05). Conclusions: While both stenting methods provide a gradual, controlled decrease in IOP, the double stenting technique was associated with a sooner and greater postoperative reduction in IOP and a good safety profile thanks to fewer HS in the early postoperative period and less need for oral acetazolamide
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
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
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