1,721,010 research outputs found

    The effect of urethane and thiopental sodium on platelet aggregation in vitro and in vivo

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    The potential in vitro (heparinized or titrated PRP) and in vivo effects of urethane and thiopental sodium on arachidonic acid, collagen, or ADP-induced rat platelet aggregation has been investigated. Both anesthetics antagonized platelet aggregation in vitro at concentrations higher than those found in plasma during anesthesia. Neither anesthetic altered the piastrinopenia induced by intravenous administration of these aggregating agents. These findings suggest that both anesthetics are suitable for in vivo platelet aggregation studies

    Facilitation of reflex micturition by intravesical administration of [βAla8]-neurokinin A (4-10), a selective NK-2 tachykinin receptor agonist

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    The ability of a selective agonist for NK-2 tackhykinin receptors to stimulate micturition in anaesthetised rats and guinea-pigs was investigated. In both species, the intravesical instillation of the peptide at uM concentrations reduced bladder capacity and residual volume, indicating a facilitatory effect on reflex micturition, whereas no plasma extravasation was produced as determined by Evans Blue leakage. In experiments on the isolated rat or guinea-pig bladder strips, the peptide induced powerful contractions. In a in vitro model of the guinea-pig whole bladder the intravesical instillation of the agonist facilitated the occurrence of rhythmic contractile activity. The selective NK-2 receptor agonist is likely able to cross the urothelium and stimulate smooth muscle contraction

    The motor effect of the capsaicin-sensitive inhibitory innervation of the rat ureter

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    Neurokinins activate TTX-insensitive rhythmic contractions of the rat isolated ureter. Field stimulation or capsaicin (1-3 uM) transiently inhibited the neurokinin-activated motility in controls but not capsain-pretreated (50 mg/kg sc) rats. The inhibitory action of field stimulation but not that of caspaicin was prevented by TTX. Thus a capsaicin-sensitive inhibitory innervation exists in the rat ureter

    Visceromotor responses to calcitonin gene-related peptide (CGRP) in the rat lower urinary tract: evidence for a transmitter role in the capsaicin-sensitive nerves of the ureter

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    Little effects of CGRP were recorded on urinary bladder motility or plasma extravation. Otherwise, CGRP inhibited motility of isolated rat proxinal urethra and ureters and counteracted the contractile response to neurokinins. Edivence is provided that CGRP is able to influence the motility of the rat lower urinary tract, but exhibits marked regional differences. Endogenous CGRP could be the the inhibitory neurotransmitter which, when released from capsaicin-sensitive fibres, participate in the control of ureteral motility

    Capsaicin‐sensitive mechanisms and experimentally induced duodenal ulcers in rats

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    The incidence and degree of cysteamine‐ or dulcerozine‐induced duodenal ulcers are increased by systemic capsaicin desensitization (50 mg kg−1 s.c. 4 days before) in adult rats. Acute administration of capsaicin, but not neurokinins or CGRP, produced a small but distinct plasma extravasation (Evans blue leakage) in the rat proximal duodenum which was absent in capsaicin‐pretreated rats. These findings indicate the existence of a capsaicin‐sensitive ‘duodenal defence mechanism’ in rats. 1987 Royal Pharmaceutical Society of Great Britai

    Capsaicin-sensitive afferents and pain arising from the urinary bladder.

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    The use of capsaicin has allowed important advances in understanding the physiological and pathophysiological roles of the sensory innervation of the bladder and urethra. For the first time, a prototype drug is available that allows selective pahrmacological manipulation of bladder sensory nerves. Major roles of these primary afferents are the signaling of pain arising from the bladder and the production of neurogenic inflammation. Available evidence indicates that capsaicin-sensitive afferents are present in the human urinary bladder. It is expected that capsaicin itself or its analogs will be of great value for diagnostic and therapeutic purposes in the urological field and particularly for treatment of painful disorders of the lower urinary tract

    The role of capsaicin-sensitive afferents in the genesis of vesical pain and inflammation.

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    The use of capsaicin, the pungent ingredient of red peppers, has led to the recognition that a particular subset of primary afferent neurons, which synthesize and release neuropeptides (tachykinins and CGRP) from both central and peripheral endings, innervates the mammalian urinary bladder. These neurons play a dual sensory and 'efferent' function. The former involves a modulatory influence on micturition reflex and mediation of pain arising form the bladder. The latter function, produced through local peripheral release of sensory neuropeptides, involves smooth muscle contraction and inflammation. Various chemicals normally present in the urine or generated during cystitis are adequate stimuli for exciting bladder afferents. Therefore an important role of capsaicin-sensitive primary afferents in mediating bladder pain and neurogenic inflammation in humans is speculated

    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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