1,720,958 research outputs found
A rapid Candida albicans hyphal‐form growth inhibition assay: determination of myelomonocytic‐mediated antifungal activity: Schnellverfahren zur Messung der Wachstumshemmung von Candida albicans durch Myelomonozyten‐vermittelte antifungale Aktivität
No full textSummary. An in vitro microassay for the measurement of Candida albicans hyphal‐form growth inhibition by myelomonocytic cells is described. The assay is rapid, easy‐to‐perform and objective. A Candida strain capable of in vitro dimorphic transition from yeast to hyphal form has been employed. The assay is based on the incorporation of 3H‐glu‐cose by the fungus, the effect being dependent upon the time of pulse, size of the inoculum and concentration of radiolabelled metabolite. In particular, C. albicans hyphal form, obtained by a 3 h incubation in vitro in the presence of 10% fetal calf serum, is co‐incubated with the effector cells. A pulse with 3H‐glucose in water is then performed and the radioactivity incorporated by the residual Candida is taken as an indication of hyphal growth. We found that polymorphonuclear cells, peritoneal macrophages and the cloned GG2EE macrophage cell line significantly inhibited hyphal growth, the effects being time and effector‐to‐target cell ratio dependent. Zusammenfassung. Es wird ein Mikroverfahren in vitro zur Messung der Wachstumshemmung von Candida albicans in der Myzelphase durch Mye‐lomonozyten beschrieben. Der Ansatz ist schnell, leicht in der Ausführung und liefert objektive Re‐sultate. Hierzu wurde ein Candida‐Stamm verwen‐det mit der Fähigkeit, in vitro den dimorphen Pha‐senwechsel von der Hefe‐ zur Myzelphase zu durch‐laufen. Der Ansatz basiert auf dem 3H‐Glucose‐Ein‐bau durch den Pilz. Dieser Einbau ist abhängig von der Expositionszeit, der Inoculum‐Größe und der Konzentration des radioaktiv markierten Metabo‐liten. Hierzu wird die C. albicans‐Myzelphase, er‐halten nach 3 h Bebrütung in vitro in der Gegen‐wart von 10%igem fötalem Kälberserum, mit den Effektorzellen ko‐inkubiert. Dann werden die Hefen der 3H‐Glucose in Wasser ausgesetzt, und die ein‐gebaute Radioaktivität in den Candida‐Zellen wird als Indikator des Hyphenwachstums angesehen. Unsere Ergebnisse zeigen, daß polymorphonukleäre Zellen, Peritonealmakrophagen und die geklonte GG2EE‐Makrophagen‐Zellinie das Hyphenwachs‐tum in Abhängigkeit von der Expositionszeit und dem Effektor/Zielzell‐Verhältnis signifikant hem‐men. Copyright © 1991, Wiley Blackwell. All rights reserve
Differential susceptibility of yeast- and hyphal-forms of Candida albicans to various natural effector cells
No full textFungicidal activity of Candida albicans-induced murine lymphokine-activated killer cells against C. albicans hyphae in vitro
No full textMultiple intraperitoneal injections of inactivated Candida albicans cells resulted in the generation of cytotoxic peritoneal cells with phenotypical and functional properties similar to in vitro-generated lymphokine-activated killer (LAK) cells. Using an in vitro [3H]glucose uptake assay, C. albicans-induced LAK-like (CA-LAK) cells exhibited high levels of anti-hyphal activity, the effects being effector to target cell (E:T) ratio- and time-dependent. Maximal levels of anti-C. albicans activity (approximately 60%) were observed after 4 h and at E:T ≥ 300:1. Similar patterns of anti-C. albicans activity were exerted by in vivo-activated natural killer (NK) cells, in vitro interleukin-2- (IL-2) generated LAK cells and polymorphonuclear cells. The anti-hyphal activity of CA-LAK cells was enriched by separation on a Percoll gradient, F2 and F3 fractions retaining most of the activity. Experiments using immunodepressed animals demonstrated that the in vivo lethality of the C. albicans hyphal form is significantly affected by in vitro pre-exposure to CA-LAK cells. While control mice receiving C. albicans alone had a median survival time of 2 d, mice receiving C. albicans pre-exposed to CA-LAK cells (E:T = 300:1) had a median survival time of 15 d. Overall, the susceptibility of the C. albicans hyphal form to CA-LAK cells suggests that C. albicans-induced effectors might play a significant role as a second-line defence mechanism against the C. albicans hyphal form
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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