1,720,964 research outputs found
2001 Odyssey in celiac disease
No full textCeliac disease, a long-life intolerance of the intestinal mucosa to gluten in genetic susceptible individuals, is characterized by gluten-dependent changes in villous morphology and/or signs of immunological activation in the lamina propria. Celiac disease, a heritable condition, seems to be related both with HLA and non-HLA genes. Gluten is the most important factor in precipitating celiac disease, it has been found in wheat but also in other cereals such as barley, rye and oats, although the role of the latter in celiac disease is still controversial. Serological screening of celiac disease is nowadays based on antiendomysial antibodies and anti-tissue transglutaminase antibodies. Recently, anti endomysial antibodies of IgG1 isotype have been reported as a new tool in the screening for celiac disease. Diagnosis is still based on the histological finding of intestinal mucosa atrophy with crypt hyperplasia on a gluten-containing diet with return to normal after a gluten-free diet, but it has recently been shown that celiac disease can also occur in the absence of mucosal damage. Intestinal mucosa biopsy culture in the presence of gliadin is able to reproduce all the immunological features of celiac disease, therefore the organ culture with in vitro gliadin challenge could be an effective useful tool in the diagnostic work-up of celiac disease
Antiendomysial antibody detection in fecal supernatants: In vivo proof that small bowel mucosa is the site of antiendomysial antibody production
No full textOBJECTIVES: Serum antiendomysial antibodies (EMAs), highly sensitive and specific serological markers of celiac disease (CD), are detectable in culture media of biopsy samples from CD patients. This finding can be considered an in vitro evidence that intestinal mucosa is a site of EMA production. To confirm this finding, we investigated the presence of EMAs and of anti-tissue transglutaminase (anti-tTG), recently identified as the autoantigen of the EMA, in fecal supernatants of CD patients. METHODS: Twenty-one newly diagnosed CD patients, 10 treated CD patients on a gluten-free diet, and 14 control disease patients on a gluten-containing diet were enrolled. Twenty-four-hour stool collections and fecal supernatants were obtained from all patients in the study. Biopsy cultures were also performed. IgA EMAs were detected in sera, culture media, and fecal supernatants. IgA, IgG, IgM, and IgE antigliadin antibodies (AGAs) and IgA anti-tTG antibodies were measured in fecal supernatants. The weights, water content, and pHs of the 24-h stool collections were also measured. RESULTS: In all untreated CD patients EMAs were detectable in sera, culture media, and fecal supernatants. In treated CD patients, EMAs were detected only in culture media after in vitro gliadin challenge. No EMAs were detected in controls. Anti-tTG levels were higher in untreated CD patients than in treated CD patients and controls. IgA AGA levels were higher in untreated CD patients than in treated CD and control patients, whereas IgM AGAs were higher in both untreated and treated CD patients than in controls. No statistically significant differences were observed for IgG and IgE AGAs among the above-mentioned populations. Fecal weights, water content, and pHs were higher in untreated CD than in control patients. CONCLUSIONS: The presence of EMAs in fecal supernatants represents the in vivo proof that intestinal mucosa is a site of EMA production. Furthermore, EMA detection in the stools could be a simple and useful additional tool to clarify diagnosis in the patchy conditions of CD. © 2002 by Am. Coll. of Gastroenterology
PHARMACOLOGICAL CHARACTERIZATION OF [LEU-13-PSI-CH2NH-LEU14]-BOMBESIN AS A SPECIFIC BOMBESIN RECEPTOR ANTAGONIST ON ISOLATED SMOOTH-MUSCLE CELLS
No full textIsolated smooth muscle cells from guinea pig stomach were used to study the pharmacological characteristics of a newly synthetized bombesin analog, [Leu13-psi-CH2NH-Leu14]-bombesin (psi 13,14-BN) to function as antagonist of bombesin-induced contractile response. The antagonism caused by this new analog was compared to that obtained with the substance P analog [D-Arg1,D-Pro2,D-Trp7,9,Leu11]Substance P [( APTTL]SP), which has been used until now to characterize bombesin receptors on smooth muscle cells. psi 13,14-BN resulted to be more potent than [APTTL]SP as antagonist of bombesin action on smooth muscle. Comparing the IC50, psi 13,14-BN (IC50 70 nM) was 8 times more potent than [APTTL]SP (IC50 600 nM). In contrast to [APTTL] SP, the action of psi 13,14-BN was shown to be specific toward bombesin receptors in that it does not interfere with receptors for other agents (i.e., cholecystokinin, acetylcholine or substance P). The antagonism induced by both compounds was competitive inasmuch as the slope of the regression lines obtained by Schild plot analysis were not significantly different from the unity. The apparent affinity for the bombesin receptor was 0.8 nM for psi 13,14-BN and 7.8 nM for [APTTL]SP. These results indicate that psi 13,14-BN acts on isolated gastric smooth muscle cells as a competitive bombesin receptor antagonist, with a higher affinity and specificity than the substance P analog used previously
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
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