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    Studies of the cardiovascular effects of nociceptin and related peptides

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    Nociceptin, a novel opioid peptide, and its ORL1 receptor share structural similarities with other opioid ligands and receptors. Although NC exerts evident cardiovascular effects at a central and peripheral level, its role in homeostatic mechanisms and disease states are just beginning to be understood, as only recently selective receptor antagonists became available. In this review, some of the new observations regarding the cardiovascular actions of NC, related peptides and newly synthesized receptor antagonists are discussed

    Cardiovascular effects of nociceptin in unanesthetized mice

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    We evaluated the systemic hemodynamic effects induced by nociceptin (NC) and NC-related peptides, including the NC receptor antagonist [Phe1c(CH2-NH)Gly2]NC(1–13)NH2 ([F/G]NC(1–13)NH2) in unanesthetized normotensive Swiss Morini mice. Bolus intravenous injection of NC decreased mean blood pressure and heart rate. The hypotensive response to 10 nmol/kg NC lasted ,10 minutes, whereas a more prolonged hypotension was evoked by 100 nmol/kg (from 11463 to 9762 mm Hg at 10 minutes, P,0.01). The latter dose reduced heart rate from 542643 to 479631 beats/min (P,0.05) and increased aortic blood flow by 4165% (P,0.05). Hypotension and bradycardia were also evoked by NC(1–17)NH2 and NC(1–13)NH2 fragments, whereas NC(1–13)OH and NC(1–9)NH2 were ineffective. Thiorphan, an inhibitor of neutral endopeptidase 24.11, enhanced the hypotension induced by NC(1–13)NH2 and revealed the ability of NC(1–13)OH to decrease mean blood pressure. [F/G]NC(1–13)NH2, a recently synthesized antagonist of the NC receptor, did not alter basal mean blood pressure or heart rate, but it prevented the hypotension, bradycardia, and increase in aortic blood flow evoked by NC. In contrast, [F/G]NC(1–13)NH2 did not alter the hypotension induced by bradykinin or endomorphin-1 (a m-receptor agonist), and the bradycardia induced by leu-enkephalin (a d-receptor agonist) or U504885 (a synthetic k-receptor agonist). In conclusion, NC and some of its fragments cause hypotension and bradycardia and increase aortic blood flow in mice, with the NC(1–13) sequence being critical for these biological effects. Our results also demonstrate that the compound [F/G]NC(1–13)NH2 is a potent and selective antagonist of the NC receptor in vivo

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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
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