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Transcriptomic profiling as a screening tool to detect trenbolone treatment in beef cattle
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Effects of an illicit cocktail on serum immunoglobulins, lymphocyte proliferation and cytokine gene expression in veal calves: preliminary results.
No full textIntroduction. The immune system (IS) is a complex multicomponent system that comprises lymphoid organs and interacting, specialised cells. Several class of harmful compounds and/or drugs (i.e. organotins, cyclosporine A, dioxins) exert their main toxic actions upon the IS, resulting in immunotoxicity or immune suppression (1). Glucocorticoids (i.e. dexamethasone, DEX) are often illegally used, alone or in combination with steroids or β-agonists, as growth promoters (GPs) in cattle (2). The use of DEX as GP has been associated with thymus atrophy, leucopoenia and decreased lymphocyte proliferative response (3). Besides, it is well known that some other GPs (i.e. clenbuterol, CLEN; 17β-oestradiol, 17βE) markedly influence the IS (4-6). Therefore, the aim of the present study was to describe possible alterations of the IS functions in veal calves administered with an illicit cocktail, by using well known methodologies (lymphocyte proliferation assay, serum immuglobulin concentrations, cytokine gene expression).
Materials and Methods. Twelve cross-bred male veal calves were divided in 2 experimental groups, of 6 animals each. The first group (weighing 162 ± 18 kg) was used as control (CTRL), whereas the second one (TRT, 166 ± 19 kg) received 17βE (3 im injections of 10 mg at 17 days intervals), CLEN (20 mg kg-1 dissolved in milk for 40 days) and DEX (4 g per animal for 7 days and then 5 g per animal for a further 5 days, dissolved in milk) for a total of 55 days. Blood sampling were withdrawn at the beginning (T0) and, then, after 15 (T1), 34 (T2), 48 (T3) days and the day before slaughtering (T4). Lymphocytes proliferation assay was executed according to Biolatti et al (2005: 3), by using concanavalin A, pokeweed mitogen and phythaemagglutinin as mitogens. Serum immunoglobulin G (IgG) and M (IgM) concentrations were determined by radial diffusion assay (Bethyl Lab., Montgomery, AL, USA). The effect of treatment upon the cytokine interleukin 1β, interleukin 8 (IL-8), tumour necrosis factor α and interferon γ gene expression levels was evaluated, using the mRNA extracted from the lymphocytes, by a dot blot technique. Data statistical analyses were performed by using the Student’s t-test (GraphPad Instat® 3.06 for Windows, GraphPad Software Inc., San Diego, CA, USA).
Results. Statistically significant reductions of T and B lymphocyte proliferative response were observed, in TRT animals, at T1 (P<0.001 and P<0.05) and, to a limited extent, at T2. Serum IgM and IgG concentrations were found significantly higher than CTRL at T2 and T4, respectively. As regards the lymphocyte cytokines gene expression, an overall slight decrease of their expression was pointed out. Such a decrease was statistically significant (P<0.05), in the case of IL-8, at T2.
Discussion and Conclusion. In the present study a significant decrease, at the early phase of the experiment, of the lymphoproliferative response was found. This was not surprising, as these blood sampling times were next to 17βE injections and it is known that oestrogens might decrease T and B cell lymphopoiesis (7). Such an effect was not observed later, in partial disagreement with previous studies which pointed out a possible immunosuppressive effect of both CLEN and DEX (8-9). However, it was recently reported that DEX, given at low doses to veal calves, reduced the lymphoproliferative response, whereas three different im administrations did not (3). Concerning the immunoglobulin data, the observed increase might be attributable to the administration of CLEN, as β-agonists have been shown to increase both serum IgG and IgM levels (10). The chosen cytokine gene expression levels were decreased pending all the experiment in TRT animals and, as a whole, confirm previously published data on each of the three drug used (11-13). The IS represents a target of many harmful chemicals and over the last ten years many efforts have been done to define tools able to predict either the level of exposure or the likely response to immunotoxicants in sentinel or target species. This study suggests that illicit drugs, given at low doses, might modulate the IS. Further studies are required to confirm and investigate these result
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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