1,720,989 research outputs found
Les lésions d'ischémie-reperfusion après thrombectomie lors d'un accident vasculaire cérébral ischémique
No full textIn experimental models of ischemic stroke, abrupt reperfusion is associated with secondary brain damages, responsible for up to 70% of the final lesion size. Whether this remains true in humans is unknown. Using data from the ASTER randomized trial (Aspiration vs Stent Retriever for Successful Revascularization), we investigated the effect of complete reperfusion (defined as a modified Thrombolysis In Cerebral Infarction 3) after endovascular thrombectomy on early lesion growth as assessed by diffusion-weighted imaging at baseline and 1 day after reperfusion. Among 381 patients included in the trial, 35 achieved complete reperfusion, benefited from both baseline and day 1 diffusion-weighted imaging, lacked significant hemorrhagic transformation, and were, therefore, included in the present study. We found that the median growth of the ischemic lesion between baseline and day 1 was only 0.9 mL after complete reperfusion, representing <4% of the mean lesion size. The actual lesion growth occurring after reperfusion is probably even smaller because this lesion growth occurred, at least in part, between baseline imaging and complete reperfusion, as demonstrated by a statistically significant positive correlation between imaging-to-reperfusion time and lesion growth (R2=0.116; P=0.048). These data support that there is no significant lesion growth after complete reperfusion in most patients. This important discrepancy between clinical and preclinical pathophysiologies should be considered during preclinical evaluation of neuroprotective strategies.Dans les modèles expérimentaux d’accident vasculaire cérébral ischémique, la reperfusion soudaine est associée à des lésions secondaires responsables de 70% du volume de lésion final. On ignore si cela est vrai également chez l’homme. En utilisant les données de l’essai randomisé ASTER, nous avons étudié l’effet d’une reperfusion complète après thrombectomie mécanique sur la croissance de la lésion, telle que mesurée par imagerie de diffusion au départ et 1 jour après la reperfusion. Sur les 381 patients inclus dans l'essai, 35 ont obtenu une reperfusion complète, ont bénéficié d'une imagerie pondérée par diffusion à la fois à l’arrivée et à J1, n'ont pas présenté de transformation hémorragique et ont donc été inclus dans l’étude. La croissance médiane de la lésion ischémique entre l’imagerie initiale et le jour 1 était de 0,9 ml après une reperfusion complète, ce qui représente moins de 4 % de la taille moyenne de la lésion à J1. La croissance réelle de la lésion après la reperfusion est probablement encore plus faible car cette croissance de la lésion s'est produite, au moins en partie, entre l'imagerie de base et le moment de la reperfusion complète, comme le démontre une corrélation positive et statistiquement significative entre le délai écoulé entre l’imagerie initiale et la reperfusion complète et la croissance de la lésion (R²=0,116 ; P=0,048). Ces données attestent qu'il n'y a pas de croissance significative des lésions après une reperfusion complète chez la plupart des patients. Cet écart important entre les physiopathologies clinique et préclinique doit être pris en compte lors de l'évaluation préclinique des stratégies de neuroprotection
Association of intravenous thrombolysis and pre-interventional reperfusion: a post hoc analysis of the SWIFT DIRECT trial
No full textBackground
A potential benefit of intravenous thrombolysis (IVT) before mechanical thrombectomy (MT) is pre-interventional reperfusion. Currently, there are few data on the occurrence of pre-interventional reperfusion in patients randomized to IVT or no IVT before MT.
Methods
SWIFT DIRECT (Solitaire With the Intention For Thrombectomy Plus Intravenous t-PA vs DIRECT Solitaire Stent-retriever Thrombectomy in Acute Anterior Circulation Stroke) was a randomized controlled trial including acute ischemic stroke IVT eligible patients being directly admitted to a comprehensive stroke center, with allocation to IVT with MT versus MT alone. The primary endpoint of this analysis was the occurrence of pre-interventional reperfusion, defined as a pre-interventional expanded Thrombolysis in Cerebral Infarction score of ≥2a. The effect of IVT and potential treatment effect heterogeneity were analyzed using logistic regression analyses.
Results
Of 396 patients, pre-interventional reperfusion occurred in 20 (10.0%) patients randomized to IVT with MT, and in 7 (3.6%) patients randomized to MT alone. Receiving IVT favored the occurrence of pre-interventional reperfusion (adjusted OR 2.91, 95% CI 1.23 to 6.87). There was no IVT treatment effect heterogeneity on the occurrence of pre-interventional reperfusion with different strata of Randomization-to-Groin-Puncture time (p for interaction=0.33), although the effect tended to be stronger in patients with a Randomization-to-Groin-Puncture time >28 min (adjusted OR 4.65, 95% CI 1.16 to 18.68). There were no significant differences in rates of functional outcomes between patients with and without pre-interventional reperfusion.
Conclusion
Even for patients with proximal large vessel occlusions and direct access to MT, IVT resulted in an absolute increase of 6% in rates of pre-interventional reperfusion. The influence of time strata on the occurrence of pre-interventional reperfusion should be studied further in an individual patient data meta-analysis of comparable trials.
Trial registration number
clinicaltrials.gov
NCT03192332
.http://dx.doi.org/10.13039/100004374 MedtronicUniversity Hospital Ber
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
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
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