1,720,955 research outputs found
Cadmium inhibits stimulated amylase secretion from isolated pancreatic lobules of the guinea-pig
No full textThe effect of cadmium chloride on pancreatic exocrine secretion 'in vitro' was examined using guinea-pig isolated lobules, Cadmium (10(-3) M) stimulated amylase release when added alone to the incubation medium and the increase of amylase was unaffected by atropine. Cadmium (10(-4) M) did not significantly modify the basal amylase release. Depolarization of pancreatic nerves with potassium stimulated amylase secretion; the stimulant effect of KCl was completely inhibited by atropine. Cadmium (10(-4) M) inhibited, but did not abolish, the stimulant effect of KCl, indicating a direct effect of the metal on the acinar cell. Cadmium (10(-4) M) also inhibited the amylase release evoked by the secretagogues carbachol and caerulein, which are known to act directly on the acinar cell. Taken together with previous data reporting a large increase of pancreatic cadmium concentration following cadmium ingestion, the strong inhibition of pancreatic secretion observed in our experiments suggests that the exocrine pancreas may be regarded as a possible target organ of cadmium toxicity. (C) 2001 Academic Press
Selective tachykinin NK3-receptor agonists stimulate in vitro exocrine pancreatic secretion in the guinea pig
No full textThe tachykinins, including substance P, neurokinin A and neurokinin B, are a mammalian peptide family that have documented motor, sensory and circulatory neurotransmitter functions in the gut. Little is known about their action on the exocrine pancreas. In this study we investigated the effects of PG-KII, a natural NK3-tachykinin receptor agonist, and senktide, a synthetic NK3-tachykinin receptor agonist, on amylase release from isolated pancreatic lobules of the guinea pig in comparison with the secretagogues carbachol, caerulein and substance P and the depolarizing agent KCl. When added to incubation flasks at various concentrations (from 10(-10) to 10(-6) M), PG-KII and senkfide both caused a dose-dependent increase in amylase release from pancreatic lobules. PG-KII and senktide elicited a lower maximal response (7.5 +/- 0.8 and 8.1 +/- 0.6% of the total lobular amylase content) than carbachol (34.4 +/- 3.9%), caerulein (26.5 +/- 2.8%) and KCl (22.5 +/- 3.8%). Whereas atropine left PG-KII and senktide-stimulated secretion unaffected, the non peptide NK3 receptor antagonist SR 142801 significantly reduced the stimulant effect of PG-KII and senktide. PG-KII (10(-7) M) also slightly though significantly increased the response to lower concentrations of caerulein (10(-11) and 10(-10) M) and carbachol (10(-7) and 10(-6) M). These findings show that PG-KII and senkfide are weak stimulants of exocrine pancreatic secretion that act directly on the acinar cells through NK3 receptors, without cholinergic involvement. We suggest also that the tachykininergic NK3 receptor system cooperates with the other known secretagogues in the control of pancreatic exocrine secretion. (C) 2002 Elsevier Science Inc. All rights reserved
Ethanol combined with cocaine inhibits amylase release in guinea pig pancreatic lobules
No full textConcurrent ingestion of alcohol and cocaine is a common occurrence in cocaine-dependent individuals. Cocaethylene is a pharmacologically active metabolite of cocaine that is formed in the liver in the presence of ethanol. The effects of ethanol combined with cocaine on the exocrine pancreas are not known. We studied the effect of ethanol and cocaine, alone or in combination, and cocaethylene on amylase release from isolated lobules of the guinea pig pancreas. Incubation of lobules with ethanol plus cocaine produced a more evident reduction of amylase release than each drug alone. An even larger reduction was observed with cocaethylene. HPLC analysis of incubation medium showed that no cocaethylene was formed in vitro in the presence of ethanol anti cocaine. It is concluded that cocaethylene could strongly contribute to inhibition of exocrine pancreatic secretion in individuals who coadminister alcohol with cocaine. (C) 2001 Academic Press
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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