1,720,982 research outputs found
An estimate of placebo effect of repetitive transcranial magnetic stimulation in epilepsy
No full textEffects of carbamazepine on pituitary-adrenal function in healthy volunteers
Full text linkCarbamazepine (CBZ) is a widely used therapeutic agent in seizure, pain, and mood disorders. Although CBZ has been shown to inhibit hypothalamic CRH secretion in vitro, limited data suggest that systemic CBZ induces pituitary-adrenal activation. Few data are available to reconcile these effects or clarify their mechanism(s), particularly in healthy human subjects. We report here a study of basal ACTH and cortisol secretion and their responses to ovine CRH administration in nine healthy volunteers, studied both during repeated (2-3 weeks) administration of CBZ and while medication free. CBZ significantly increased mean 24-h urinary free cortisol (mean +/- SE, 197 +/- 17 vs. 137 +/- 24 nmol/day; P less than 0.02) and evening basal total plasma cortisol (113 +/- 17 vs. 83 +/- 14 nmol/L; P less than 0.05) as well as cortisol-binding globulin-binding capacity (497 +/- 36 vs. 433 +/- 28 nmol/L; P less than 0.01). Despite the CBZ-induced hypercortisolism, plasma ACTH responses to CRH during CBZ treatment remained robust, rather than being suppressed by basal hypercortisolism. In fact, during CBZ treatment, we noted a positive correlation between the increase in basal plasma cortisol and the increase in the plasma ACTH response to CRH (r = 0.65; P less than 0.05). We also observed a reduction in cortisol-binding globulin-binding capacity after CRH administration (315 +/- 25 vs. 433 +/- 28 nmol/L; P less than 0.001), which was accentuated by CBZ treatment (342 +/- 19 vs. 497 +/- 36 nmol/L; P less than 0.001; magnitude of fall, -155 +/- 22 nmol/L on CBZ vs. -118 +/- 11 nmol/L off CBZ; P less than 0.05). We conclude that CBZ increases plasma cortisol secretion in healthy volunteers independent of its effect on plasma cortisol-binding capacity. This pituitary-adrenal activation seems to reflect a pituitary, rather than a hypothalamic, effect of CBZ. Hence, despite CBZ-induced hypercortisolism, the ACTH response to CRH remained robust in direct proportion to the CBZ-induced rise in basal plasma cortisol. Thus, we propose that the increased cortisol secretion observed during CBZ treatment reflects a relative inefficacy of glucocorticoid negative feedback at the pituitary. This pituitary-driven increase in cortisol secretion combined with the expected reduction in centrally directed CRH secretion could contribute to the anticonvulsant properties of CBZ
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
Epileptogenesis and rational therapeutic strategies.
No full textThe understanding of neurobiological mechanisms of epileptogenesis is essential for rational approaches for a possible disease modification as well as treatment of underlying causes of the epilepsies. More effort is necessary to translate results from basic investigations into new approaches for clinical research and to better understand a relationship with findings from clinical studies. The following report is a condensed synapsis in which molecular mechanisms of epileptogenesis, pharmacological modulation of epileptogenesis, evidence based therapy, refractoriness and prediction of outcome is provided in order to stimulate further collaborative international research
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