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Effect of the prostacyclin analogue iloprost on endothelial progenitor cell apoptosis and cytokine paracrine release
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Spheroids from equine amnion mesenchymal stem cells: an in vitro study
Get PDFBackground: Equine amnion mesenchymal stem cells (EAMSCs) from amnion isolated after the foal birth represented an alternative source of easy collection of mesenchymal cells used in equine regenerative medicine.
Methods: These cells grown as 2D culture in α-MEM medium supplemented with EGF were differentiated in adipogenic, chondrogenic and osteogenic cells. Half a million cells as pellet were left in 15ml tubes with the same differentiation media for 20 days. After the pellets were collected, embedded in paraffin for morphological study.
Results: 2D culture showed EAMSCs with an embryonic phenotype (C-kit+, CD105+, Oct-4+) and a differentiation potential in adipogenic, chondrogenic and osteogenic multipotent cells. By a reproducible method of 3D culture, at day 20 the Authors evidenced a formation of small aggregated spheroids gradually gathering. In cross sections the surface of spheroid evidenced flattened cells embedded in a red matrix by Alizarin staining and occasionally a core of calcium precipitation. A network of apoptotic or necrotic cells in a not mineralized matrix was present into the center of nodules. The 3D spheroids appeared larger (mean diameter of 605±53 μm for gathering spheroids and 1486±79 μm for spheroids already gathered) than those from standard monolayer cultures (mean diameter of 200 ± 73 μm).
Conclusions: EAMSCs cultured in 3D method preserve their in vitro multipotent differentiation than adherent 2D culture method. These EAMSCs included in extracellular matrix not mineralized at day 20 seem to be a good source of MSCs for tissue repair and regeneration in equine medicine
Decellularizzazione di valvole cardiache porcine quali scaffolds per cellule progenitrici endoteliali autologhe
No full textBoth carotid and peripheral percutaneous transluminal angioplasty mobilize progenitor cells
No full textIt is well known that circulating endothelial progenitor cells (EPC) are involved in injured endothelium repair, contributing to angiogenesis in in vitro and in vivo models. The main triggers of EPC mobilization from bone marrow to peripheral blood are ischemia and vascular trauma. Endothelial injury induced by coronary angioplasty has been recently shown as sufficient to trigger EPC mobilization in coronary artery disease (CAD) patients. Aim of our work was to evaluate the effect of internal carotid angioplasty and peripheral transluminal angioplasty on circulating progenitor cells (PC, CD34+ cells) and EPC (CD34+KDR+ cells) mobilization. Methods: 10 patients (7 males and 3 females, mean age 64.2 ± 10.3 years) undergoing elective percutaneous transluminal angioplasty (PTA) were consecutively enrolled. 5 patients underwent internal carotid angioplasty (IC-PTA) and the others peripheral transluminal angioplasty (P-PTA). Inclusion criteria were: carotid stenosis greater than 70 for IC-PTA; peripheral stenosis greater than 70 and documented peripheral arterial disease (PAD), defined by an intermittent claudication (Leriche-Fontaine stage II) for P-PTA. Patients with unstable angina, myocardial infarction or stroke within the preceding 3 months were excluded to avoid any potentially confounding effect. Peripheral blood samples were collected at the time of admission (t0), on day 1 (t1), on day 7 (t7) and on day 30 (t30). C-reactive protein (CRP), white blood cells (WBC) and VEGF were evaluated. Circulating PC and EPC were determined by flow cytometry analysis. Data are expressed as cells number per ml of blood according to the International Society of Hematotherapy and Graft Engineering protocol. Patients were treated according to the international guidelines and the angioplasty outcome was evaluated by Echo colour Doppler ultrasonography at t1, t7 and t30. Results: No significant differences were found in the prevalence of risk factors. The efficacy of PTA was confirmed in all patients, showing stent patency by Echo colour Doppler evaluation. In all patients the PC count at t7 was significantly increased compared with basal level (t0: 1694±141/mL vs. t7: 2748±375/mL, p0.024) and t1 (t1: 1413±215/mL vs. t7: 2748±375/mL, p0.002), in parallel to VEGF concentration (t0: 530±95 vs t7: 759±153 pg/mL, p0.024; t1: 555±92 vs t7: 759±153 pg/mL, p0.037). Regarding EPC levels, at t7 a trend to an increase compared to both t0 (t0: 595±72/mL vs. t7: 737±98/mL, p0.085) and t1 (t1: 529±87/mL vs. t7: 737±98/mL, p0.052) was observed, maintained up to day 30. CRP was significantly increased after angioplasty, with a peak at t1 (t0: 4.3±0.5 vs t1: 42.3±13.8 mg/L, p0.028), remaining elevated at t7 (t0: 4.3±0.5 vs t7: 26.2±4.3 mg/L, p0.001) and decreasing to baseline levels at t30. Considering IC-PTA and P-PTA separately, in the first group we observed both for PC and EPC levels a trend to increase lasting up to 30 days, while in P-PTA patients the mobilization lasted only up to 7 days. Conclusions: Our data show a transient PC and EPC mobilization together with an increase of VEGF and CRP levels following vascular injury, suggesting that it can be part of an inflammatory response PTA-induced. No relevant differences seem to exist between IC-PTA and P-PTA except for 1-month progenitor quantification. Longitudinal studies and a greater number of patients are required to determinate the role that PC mobilization PTA-induced may play as prognostic factor to identify high-risk patients for restenosis and other cardiovascular events after PTA
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
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