1,721,058 research outputs found
Block of delayed-rectifier potassium channels by reduced haloperidol and related compounds in mouse cortical neurons
No full textHaloperidol is known as an antagonist of dopamine D2 receptors. However, it also blocks a variety of ion channels at concentrations above the therapeutic range. Reduced haloperidol (R-haloperidol), one of the main metabolites of haloperidol, has been reported to accumulate in certain tissues, particularly in brain cortex, and it may produce the pharmacological effects associated with haloperidol treatment. In this study, we assessed the effect of R-haloperidol and other related compounds on native delayed-rectifier potassium channels (K-DR) in mouse cortical neurons by using the whole-cell patch-clamp technique. Although R-haloperidol has much lower affinity to D2 receptors than haloperidol, the IC50 of R-haloperidol to block K-DR currents was 4.4 mu M, similar to its parent compound. The binding site of R-haloperidol is on the cytoplasmic side of the channel because its quaternary derivative preferentially inhibited the currents from intracellular side. 4-Chlorophenyl-4-hydroxypiperidine (4C4HP) is the active fragment of haloperidol because other compounds containing this moiety, including L-741,626 (3-[4-(4-chlorophenyl)-4-hydroxypiperidin-L-yl]-methyl-1H-indole) and loperamide, also blocked K-DR channels. The potency of the 4C4HP fragment positively correlated with the hydrophobicity index (clogP) of the compounds tested. We conclude that R-haloperidol is a K-DR channel blocker, although it does not interfere with the normal channel function at a clinically relevant concentration
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
In vivo and in vitro development of mouse pancreatic beta-cells in organotypic slices
No full textTaking tissue slices of the embryonic and newborn pancreas is a novel approach for the study of the perinatal development of this gland. The aim of this study was to describe the morphology and physiology of in vivo and in vitro developing beta-cells. In addition, we wanted to lay a foundation for the functional analysis of other pancreatic cells, either alone or as part of an integrative pancreatic physiology approach. We used cytochemistry and light microscopy to detect specific markers and the whole-cell patch-clamp to assess the function of single beta-cells. The insulin signal in the embryonic beta-cells was condensed to a subcellular compartment and redistributed throughout the cytosol during the first 2 days after birth. The hormone distribution correlated well with the development of membrane excitability and hormone release competence in beta-cells. Endocrine cells survived in the organotypic tissue culture and maintained their physiological properties for weeks. We conclude that our preparation fulfills the criteria for a method of choice to characterize the function of developing pancreas in wild-type and genetically modified mice that die at birth. We suggest organotypic culture for in vitro studies of the development and regeneration of beta-cells
Occurrence and genotypic characterization of C. difficile in food, animals and in the environment in Italy and Switzerland
No full textThe aim of this work was to investigate the occurrence of C. difficile ribotypes in sea food, animals
and the environment in Southern Italy and in Ticino Canton (Switzerland). A comparison of
ribotypes with those associated to human CDI in Ticino Canton was also carried out. Samples of
seawater (25), zooplankton (5), sea sediments (5), shellfish (105), river water (5), lake water (8), lake
sediments (8) and raw (1) and treated wastewater (1) were collected in different areas of Campania
and Basilicata regions, in Southern Italy. In Ticino, rectal swabs from ruminants (150) and piglets
(2) and samples of influents (9) and effluents (9) from the 9 largest wastewater purification plants
of the region were also collected. Molecular identification, toxin genes detection, toxinotyping
and ribotyping were carried out on the isolates. In Italy, C. difficile was isolated from seawater,
zooplankton, edible shellfish, river water, lake sediments and in both samples of raw and treated
wastewater analyzed. In Ticino Canton C. difficile was recovered from ruminants, piglets and
wastewater. Taking all the environmental strains into account, toxinotype V/ribotype 078 was the
most common isolate, followed by toxinotype 0/ribotypes 014 and 070, and nontoxigenic
strains/ribotype 010. Toxinotype 0 strains were the most frequently isolated in all the meat
producing animals investigated, while the most common ribotypes were 001 and 066. Shellfish, a
popular food in Southern Italy usually eaten raw or lightly cooked, were found to be contaminated
with toxigenic C. difficile; ribotypes 014 and 078 were the most commonly found among these
isolates. Some of the ribotypes of C. difficile isolated in Ticino Canton overlapped with those
responsible of human CDI in 2010 in the same geographic area. The lack of epidemiological data
in Southern Italy on the incidence of CDI prevented us from drawing a similar correlation. The
results of the 2008 European survey about the incidence of CDI in European hospitals highlighted
that the most prevalent clinical ribotypes recovered in Italy were 078, 001, 014, 106, 126, 018, the
same ribotypes we found in shellfish, lake sediments and wastewater in this area. This work points
out a possible health risk associated to the widespread diffusion of virulent C. difficile strains,
including the hypervirulent C. difficile ribotype 078, in environmental, animal and sea food sources
in both Ticino Canton and Southern Italy
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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