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The effect of U-74389G on experimental pancreas ischemia reperfusion injury, encompassing ischemic preconditioning in a swine model: biochemical, hemodynamic and histopathologic study
No full textObjective: A pivotal role of lazaroid U-74389G, as specific antioxidant factor oftissue damage in various organs, has recently been suggested. In addition,preconditioning by brief exposure to ischemia protects tissues against damage evokedby subsequent severe ischemia.The objective of this study was to elucidate the effect of U-74389G and thephenomenon of ischemic preconditioning, in an experimental Ischemia Reperfusioninduced pancreatiitis and to determine the oxidative stress.Design: Prospective randomized controlled studySetting: 1st Department of Propaedeutic Surgery, Hippokratio Hospital, University ofAthens, 114 Vas Sofias Avenue, Athens 116 27, Greece and Experimental–ResearchCenter, Elpen Pharmaceuticals, Athens, GreeceSubjects: Twenty four (male and female) pigs, weighting 28–35 kg.Background. Oxidative stress is a crucial factor in the pathophysiology of acutepancreatitis and its systemic complications. Lazaroids are a novel class of antioxidantsthat potently protect pancreatic acinar cells against oxidant attack. The aim of ourstudy was to evaluate the therapeutic potential of 21-aminosteroid U-74389G inpancreatic injury after ischemia and reperfusion of the organ, in a swine model.Materials and methods. Twelve pigs (28–35 kg), were randomized into the followingtwo experimental groups: Group A (control group, n=6): Ischemia of pancreas (30min) followed by reperfusion for 120 min and Group B (n=6): Ischemia of pancreas(30 min), U-74389G intravenous injection (10 mg/kg) in the inferior vena cava, andreperfusion for 120 min. Tissue and blood sampling was conducted at 0, 30, 60, 90and 120 min after reperfusion. Repeated-measures ANOVA was performed for theevaluation of differences between the two groups.Results. Histopathological evaluation did not reveal a statistically significantdifference concerning hemorrhage (p=0.193), leukocyte infiltration (p=0.838), acinarnecrosis (p=0.183) and vacuolization (p=0.185) in the pancreatic tissue between thetwo groups; nevertheless, edema seemed more pronounced in the U-74389G group(p=0.020). Serum metabolic data in the control and therapy groups were notsignificantly different; accordingly, tissue malondialdehyde levels (p=0.705) andtumor necrosis factor-α values (p=0.863) did not differ between the two groups.Conclusion. Based on the histological data and the absence of reduction in themalondialdehyde and tumor necrosis factor-α levels, it is concluded that theadministration of U-74389G does not seem to exert a sizable therapeutic effect inattenuating pancreatic damage from ischemia-reperfusion injury.BACKGROUND/PURPOSE: The potential of lazaroid U-74389G in attenuatinginjury after ischemia and reperfusion has been reported in the context of variousorgans. The present study focuses specifically on the pancreas and aims to examineany effects of U-74389G in a swine model of pancreatic ischemia and reperfusion,encompassing ischemic preconditioning.METHODS: Twelve pigs, weighing 28–35 kg, were randomized into twoexperimental groups: Group A (control group, n=6): Two periods of ischemicpreconditioning (5 min each) separated by a 5- min rest interval; then ischemia time30 min and reperfusion for 120 min. Group B (n=6): the same as above, with U-74389G intravenous injection in the inferior vena cava immediately prior to theinitiation of reperfusion. Blood sampling and pancreatic biopsies were conducted at 0,30, 60, 90 and 120 min after reperfusion. Repeated-measures ANOVA wasundertaken to evaluate differences between the two study groups.RESULTS: No statistically significant differences were noted concerning thehistopathological parameters in the control and therapy groups (p=0.563 for edema,p=0.241 for hemorrhage, p=0.256 for leukocyte infiltration, p=0.231 for acinarnecrosis and p=0.438 for vacuolization). In accordance with the above, serummetabolic data (glucose, creatinine, urea, total and direct bilirubin, total calcium,amylase, lipase, SGOT/AST, SGPT/ALT, ALP, γGT, LDH, CRP, insulin) were notsignificantly different between the two groups; similarly, tumor necrosis factor-αvalues (p=0.705) and tissue malondialdehyde levels (p=0.628) did not differ betweenthe control and therapy groups.CONCLUSIONS: This swine model of pancreatic ischemia and reperfusion,encompassing preconditioning, indicates that U-74389G lazaroid does not seem toexert protective effects from pancreatic damage.Σκοπός: Σκοπός της παρούσης πειραματικής μελέτης είναι η δοκιμή τουαντιοξειδωτικού U-74389G σε ζωικό πρότυπο χοίρου και συγκεκριμένα σεπρωτόκολλο βραχείας διάρκειας ισχαιμίας / ισχαιμίας / επαναιμάτωσης παγκρέατος.Θα μελετηθεί βιοχημικά, αιμοδυναμικά και ιστοπαθολογικά η ευεγερτική ή μη δράσητου συγκεκριμένου μορίου. Έμφαση θα δοθεί στην επίδραση της βραχείας διάρκειαςισχαιμίας (ischemic preconditioning).Σχεδιασμός: Προοπτική τυχαιοποιημένη ελεγχόμενη μελέτηΤοποθεσία: Πειραματικό Χειρουργείο Ερευνητικού-Πειραματικού Κέντρου ELPENΑ.ΕΠειραματόζωα: 24 Χοίροι (αρσενικοί ή θηλυκοί) βάρους 28-35 kgΠείραμα: Τα πειραματόζώα κατανεμήθηκαν τυχαιοποιημένα σε 4 πειραματικέςομάδες (6 ζώα σε κάθε ομάδα) και υπεβλήθησαν σε 30 min ισχαιμία και ακολούθωςσε 120 min επαναιμάτωσης παγκρέατος, σύμφωνα με το κατατεθέν ερευνητικόπρωτόκολλο.Η δόση του αντιοξειδωτικού μορίου είναι 10 mg/kg βάρους σώματος του ζώου.Επειδή το μόριο είναι πρωτότυπο δικαιούμαστε σε αυτήν τη φάση να μην τοσυγκρίνουμε με άλλο μόριο που θα χρησιμεύσει ως θετικός μάρτυρας (γνωστήευεργετική ή έστω απλά θετική δράση).Μετρήσεις και Κύρια ΑποτελέσματαΒιοχημική μελέτη:-Γενικός βιοχημικός κύκλος (ηπατικός κύκλος, γλυκόζη, αμυλάση, λιπάση,κρεατινίνη, CRP)-Αιματολογικός έλεγχος-Έλεγχος πηκτικότητας (APTT, D-dimers)-ΤΝF-α. Ο ΤΝF-α διαδραματίζει κεντρικό ρόλο στην παθογένεση της οξείαςπαγκρεατίδας και συσχετίζεται με συνακόλουθες επιπλοκές.-MDA (malondialdehyde). Η MDA ιστού είναι δείκτης οξειδωτικού stress και ως εκτούτου μπορεί να προσδιορίσει την αποτελεσματικότητα του αντιοξειδωτικού.Η επιλογή των προαναφερθέντων βιοχημικών παραγόντων βασίστηκε σε συγκερασμόπειραματικών και κλινικών μελετών. Παρατέθηκε ποικιλία μορίων, προκειμένου ναεπιλεγούν τα περισσότερο ενδιαφέροντα και αξιόπιστα.Αιμοδυναμική Μελέτη:Έλεγχος καρδιακής λειτουργίας, αρτηριακής και φλεβικής πίεσης, οξυμετρίας,αερίων αίματος.Ιστοπαθολογική Μελέτη:Αναλυτική ιστοπαθολογική μελέτη (παθολογοανατομική) και βαθμολόγηση τωνευρημάτων με score. Στο τέλος του πειράματος, εκτός από το πάγκρεας, θα ληφθούντεμάχια ήπατος, νεφρού, καρδιάς και πνευμόνων ( βιοψίες ).Συμπεράσματα: Βασιζόμενοι στα ιστοπαθολογικά αποτελέσματα και στην απουσίαελλάτωσης των MDA TNF-α, συμπεραίνεται ότι η χορήγηση του λαζαροειδούς U-74389G σε πειραματικό μοντέλο ισχαιμίας επαναιμάτωσης παγκρέατος χοίρου, δενφαίνεται να δείχνει αξιοσημείωτη θεραπευτική επίδραση ή να μετριάζει τις βλάβεςτων ελευθέρων ριζών από ισχαιμία και συνακόλουθη επαναιμάτωση.Επιπροσθέτως, σύμφωνα με την ανάλυση των αποτελεσμάτων της παρούσης ερεύνης,προκύπτει ότι το υπό μελέτη αντιοξειδωτικό μόριο επιδείνωσε την εμφάνισηπαγκρεατικού οιδήματος, τόσο ενδοπαρεγχυματικά όσο και στο διάμεσο χώρο τουοργάνου και μάλιστα με στατιστική σημαντικότητα της τάξεως, p=0.020. Ωστόσο, ηπροσθήκη στο πειραματικό μοντέλο του χειρισμού της ισχαιμικής προπόνησης(ischemic preconditioning), οδήγησε σε εξουδετέρωση αυτής της ανεπιθυμήτουδράσεως
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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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