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Antinociceptive and Anti-Inflammatory Activities of Zerumbone from Zingiber Zerumbet (l.) Roscoe ex sm., and its Possible Mechanisms of Action
No full textThe present study was conducted to investigate the antinociceptive and antiinflammatory activities of zerumbone and its possible mechanism of action in animals. Zerumbone is a sesquiterpene isolated and purified from the rhizomes of the Z. zerumbet plant, locally known as ‘lempoyang’. Z. zerumbet is one of the most important species of cultivated ginger, used in food flavoring and commonly used in traditional medicine to treat stomach aches, toothaches, muscle sprain and as a cure for swelling, sores and cuts. Zerumbone was obtained from the rhizomes through a sequence of isolation processes involving hydro-distillation, column chromatography and followed by recrystallization. The compound was subjected to thin layer chromatography (TLC), gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography (HPLC) to identify the chemical structure and ensure its purity. Zerumbone was optimally isolated using the hexane and ethyl acetate solvent system at a ratio of 8:2 with a total yield of 0.07%. Toxicological analysis comprising of acute, sub-acute and sub-chronis tests showed that oral and intraperitoneal administration of zerumbone at doses of 10 - 1000 mg/kg did not show any signs of toxicity in terms of behavioral changes, weights of body, liver and kidneys, hematological and liver function parameters. The findings were further supported by the histopathological observations of the liver that demonstrated normal histological architecture. Zerumbone (10 - 100 mg/kg, p.o.) was also found to possess significant gastroprotective effects on the ethanol-induced ulcer model, with the higher doses showing promising results in comparison with ranitidine (100 mg/kg, p.o), a commercially available gastric ulcer medication. The determination of the antinociceptive profile of zerumbone using the acetic acid-induced abdominal writhing test and hot plate test showed significant pain inhibition, suggesting the possible involvement of zerumbone in both peripheral and central systems of the pain pathway. The rota-rod evaluation confirmed that the antinociceptive effects of zerumbone were not in relation to any sedative or nervous system suppression. Further experiments demonstrated that zerumbone interacts with both the δ- and κ-opioid receptors coupled to Ca2+ channels but not through the μ-opioid receptors.The study continued to demonstrate the ability of zerumbone to inhibit pain through the nitric oxide pathway inactivating a series of event involving the L-Arginine-NOcGMP-PKC-K+-ATP channel pathways in the acetic acid-induced abdominal writhing test. The interaction of zerumbone with three other receptors mainly the NMDA receptor, TRPV1 and B2 receptors were elucidated. The involvement of other prominent receptors involved in antinociception including GABAergic,cholinergic, dopaminergic, noradrenergic, serotonergic and adenosinergic systems in zerumbone-induced antinociception were investigated, with results demonstrating that zerumbone induces antinociception through the involvement of the mentioned systems except for the cholinergic system. The Ca2+ activated potassium channels were investigated, eventually confirming the involvement of the small and large conductance calcium-gated K+ channels, voltage-gated K+ and ATP-gated K+channels. To conclude the antinociceptive study, the activation of the spinal cord nociresponsive neurons was evaluated using the expression of the c-fos protein in the spinal cords of rats through the formalin test. The use of immunohistochemistry to identify c-fos-like immunoreactivity (c-fos-LI) showed significant reduction in the expression of c-fos proteins reaffirming the central and more crucially, the involvement of the spinal cord in zerumbone’s antinociception, a significant step before pain signals are transmitted to the brain. The anti-inflammatory study was conducted using both the carrageenan-induced paw oedema test and the cottonpellet-induced granulomatous test. The findings in both the experiments showed that zerumbone possesses anti-inflammatory effect against both exudative and proliferative phases of inflammation. The mechanism of action of the antiinflammatory activity of zerumbone was evaluated using various inflammatory chemical mediators that act as inducers, mainly bradykinin, histamine, serotonin,prostaglandin E2, substance P, phospholipase A2 and arachidonic acid, of which zerumbone (100 mg/kg, i.p.) significantly suppressed all inflammatory mediatorsinduced experiments. As a conclusion, the study strongly confirms the antinociceptive and anti-inflammatory activities of zerumbone and also elucidated the possible mechanism of action through which it exerts its effect. In adition to that,the toxicity studies demonstrated the safety margin of zerumbone in mice, thus scientifically justifying the traditional use of this species of ginger, and setting the path for future studies
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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