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Interleukin-18 is expressed in rat testis and may promote germ cell growth
No full textMona-Lisa Strand, Aida Wahlgren, Konstantin Svechnikov, Cecilia Zetterstroma, Brian P. Setchell, Olle Sode
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
Antimicrobial and xenobiotic defence in the mammalian testis
No full textDifferent mechanisms exist in the mammalian testis to protect the germ cells from autoimmune attack, invading microbes, and xenobiotic induced toxicity, which would otherwise be deleterious to the preservation of fertility. The general aim of this thesis was to study these testicular defence mechanisms, including the structural building blocks of the blood– testis barrier (BTB), antimicrobial peptides, proinflammatory cytokines and ATP-binding cassette (ABC) transporter proteins.Coxsackie and Adenovirus Receptor (CAR) is a cell adhesion molecule present in tight junctions of epithelial cells. We found that CAR was expressed in male germ cells in the human, the rat and the mouse testis, with a localization corresponding to the acrosomal structure of the elongated spermatids as well as in mature spermatozoa. CAR co-localized and co-immunoprecipitated with JAM-C in the mouse testis, suggesting that CAR may function in germ cell differentiation and polarization, similar to JAM-C.Interleukin-18 (IL-18) is a proinflammtory cytokine that contributes to host defence in epithelial barrier tissues. We found that IL-18, the IL-18 receptor and the interleukin-1β converting enzyme (ICE) was expressed in the rat testis throughout postnatal development. IL-18 protein and messenger ribonucleic acid (mRNA) were mainly localized in meiotic and post-meiotic germ cells. Only Pro-IL-18 was detected in interstitial fluid and in testicular cell extracts, suggesting that IL-18 normally is in its non-active form in the healthy testis, but may become activated during testicular infection. Recombinant IL-18 stimulated spermatogonial proliferation and thus may act as a growth factor during patho-physiological conditions in the testis.The nuclear protein High mobility group box chromosomal protein-1 (HMGB1) does also have extracellular immune-functions, including cytokine stimulation and direct antimicrobial activity. We found that HMGB1 was expressed in the nucleus and in the cytoplasm of Sertoli cells in the human and rat testis. HMGB1 protein was also present in interstitial fluid collected from non-treated rat testis, indicating extracellular release. HMGB1 purified from human and rat testis demonstrated strong and direct antibacterial activity and thus may act as an antimicrobial peptide in the seminiferous epithelium, contributing to the protection of the developing germ cells against invading pathogens.The ABC transporter family is responsible for active transport of substrates across membranes. They are located in barrier tissues such as the BTB and the blood– brain barrier (BBB) and protect against uptake of xenobiotics. We found that testes from immature (6-day-old) rats accumulated significantly higher levels of the ABC transporter substrate and anticancer drug doxorubicin, compared to the testes from 16- and 24-day old rats. This correlated with a significantly lower level of testicular expression of ABC transporters compared to 16- and 24-day-old rats. Thus, lack of a mature ABC transporter efflux system may render the immature testis more susceptible to xenobiotic-induced toxicity.The studies described here support the view that the mammalian testis has evolved several defence mechanisms to preserve fertility.List of scientific papersI. Mirza M, Hreinsson J, Strand ML, Hovatta O, Söder O, Philipson L, Pettersson RF, Sollerbrant K. Coxsackievirus and Adenovirus receptor (CAR) is expressed in male germ cells and forms a complex with the differentiation factor JAM-C in mouse testis. Experimental Cell Research. 2006, 312: 817-30. https://doi.org/10.1016/j.yexcr.2005.11.030 II. Strand ML, Wahlgren A, Svechnikov K, Zetterström C, Setchell BP, Söder O. Interleukin 18 is expressed in rat testis and may promote germ cell growth. Molecular and Cellular Endocrinology. 2005, 240: 64-73. https://doi.org/10.1016/j.mce.2005.05.011 III. Zetterström C, Strand ML, Söder O. The high mobility group box chromosomal protein 1 (HMGB1) is expressed in the human and rat testis where it may function as an antibacterial factor. Hum Reprod. 2006 Nov; 21(11):2801-9. https://doi.org/10.1093/humrep/del256 IV. Strand ML, Jahnukainen K, Sultana T, Hou M, Eksborg S, Ritzmo C, Melaine M, Jégou B and Söder O. The age dependent testicular expression pattern of ABC transporters renders the immature testis more susceptible to adverse actions of cytotoxic drugs. [Manuscript]</p
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
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