1,720,984 research outputs found
Mucosal immunity induced by gliadin-presenting spores of Bacillus subtilis in HLA-DQ8-transgenic mice
No full textThe induction of mucosal immunity requires efficient antigen delivery and adjuvant systems. Probiotic bacterial strains are considered to be very promising tools to address both of these needs. In particular, Bacillus subtilis spores are currently under investigation as a long-lived, protease-resistant adjuvant system for different antigens. Furthermore, a non-recombinant approach has been developed based on the stable adsorption of antigen on the spore surface. In the present study, we explored this strategy as a means of modulating the immune response to wheat gliadin, the triggering agent of celiac disease (CD), an enteropathy driven by inflammatory CD4+ T cells. Gliadin adsorption was tested on untreated or autoclaved wild-type (wt) and mutant (cotH or cotE) spores. We found that gliadin was stably and maximally adsorbed by autoclaved wt spores. We then tested the immune properties of the spore-adsorbed gliadin in HLA-DQ8-transgenic mice, which express one of the two HLA heterodimers associated with CD. In vitro, spore-adsorbed gliadin was efficiently taken up by mouse dendritic cells (DCs). Interestingly, gliadin-pulsed DCs efficiently stimulated splenic CD4+ T cells from mice immunised with spore-adsorbed gliadin. Nasal pre-dosing with spore-adsorbed gliadin failed to down-regulate the ongoing cellular response in gliadin-sensitised DQ8 mice. Notably, naïve mice inoculated intranasally with multiple doses of spore-adsorbed gliadin developed an intestinal antigen-specific CD4+ T cell-mediated response. In conclusion, our data highlight the ability of spore-adsorbed gliadin to elicit a T-cell response in the gut that could be exploitable for developing immune strategies in CD
D-amino acid oxidase from Trigonopsis variabilis: immobilisation of whole cells in natural polymeric gels for glutaryl-7-aminocephalosporanic acid production
Full text linkThe enzymatic oxidation of cephalosporin C to glutaryl-7-amminocephalosporanic acid (glutaryl-7-ACA) was carried out utilizing permeabilized whole cells of the yeast Trigonopsis variabilis entrapped in Ca-alginate beads. The biomass, cultured in a rich medium containing D,L methionine and harvested after 72 h of growth, exhibited high levels of D-aminoacid oxidase activity. Prior to use, thewho,lke cells were permeabilized with four freeze-thawing cycles and immobilized in polysaccharide matrices, such as Ca-alginate and K- carrageenan, and in an insolubilised gelatin gel. The best results in terms of activity yield and storage stability were obtained with cells entrapped in Ca-alginate beads. These cells were utilized for glutaryl-7-ACA production in a continuous stirred batch reactor (CSTR) and in a packed bed reactor working in a plug flow reactor (PFR), using 50 mm Cephalosporin C as substrate. The performances of the two systems were compared. The overall on a void volume basis) were 1.63 g and 255 mg of glutaryl-7-ACA h-1 in the PFR and in CSTR, respectively
PROTECTIVE ACTIVITY OF CIS9,TRANS11 CONJUGATED LINOLEIC ACID ISOMER IN A MOUSE MODEL OF GLUTEN SENSITIVITY: AN HISTOMORPHOLOGICAL STUDY
No full textCOX inhibition by indomethacin and gliadin administration
to sensitized transgenic mice expressing the HLA-DQ8 heterodimer (DQ8 mice), was recently proposed as specific animal model of gluten sensitivity. Conjugated Linoleic Acid, a
collective term used to describe a mixture of c9t11, and
t10c12 isomer of linoleic acid, exhibited protective effects
against gluten-mediated toxic effects on DQ8 mice intestine,
however the role of individual isomer is still unclear.
Three groups of 6-12 weeks-old DQ8 mice (n=7 each) were
examined. One group received indomethacin (1.5 mg/100 mL
in drinking water) and it wasintra-gastrically administered
with 500 g of a chymotryptic digest of gliadin (days 0, 3, 5
and 7) before sacrifice (day 10) (indo+gliadin, T). Another
group was pre-treated by oral administration of c9,t11 isomer
for 14 days (15 mg/day) before indo+gliadin (C9+T); the last untreated group was used as control (Ct). A morphometric
analysis was performed on paraffin sections of small
intestinesamples to evaluate the protective effects produced
by the c9,t11 pre-treatment.In particular, the sections were
stained with hematoxylin-eosin, to observe the general morphology and to evaluate the villus/crypts ratio, orwith PAS to determine the occurrence and distribution of globet cells.
Intestinal villi atrophy and decreased number of PAS+ globet
cells occurred in T micewhereas intestinal histomorphology of
C9+T animals was comparable with that of Ct. Presented
findings demonstrates a clear protective effect of c9,t11 isomer
against the harmful effects triggered by indo+gliadin
treatment
L’Acquedotto Romano ipogeo e la Fontana di Helvius a Sant’Egidio del Monte Albino (Salerno, Campania)
No full textLe ricerche speleologiche condotte negli ultimi anni stanno approfondendo le conoscenze su alcuni piccoli
ma interessanti acquedotti ipogei diffusi sul territorio campano. Queste opere sebbene caratterizzate da modesti
sviluppi, rappresentavano importanti fonti di approvvigionamento idropotabile per piccole comunità
rurali.
In questa nota si riporta lo studio e il rilievo topografico di una galleria drenante ubicata nel comune di
Sant’Egidio del Monte Albino, in provincia di Salerno, situato alle falde del settore settentrionale dei Monti
Lattari, non lontano dalle note città romane di Pompei, Nocera e Stabia.
L’acquedotto è stato interamente scavato in depositi di conoide costituiti da alternanze di livelli di ghiaie
e piroclastiti pedogenizzate per complessivi 478 m di sviluppo. Con riferimento ai soli condotti idraulici, il
sistema di gallerie risale nella fascia pedemontana per circa 16 m al fine di drenare le acque di falda che si
raccolgono nel materasso della conoide detritico-alluvionale che si sviluppa allo sbocco del Vallone del Lupo.
L’opera è composta da un ramo principale e tre rami laterali minori.
Le tracce più antiche dell’abitato in cui si trova l’acquedotto, facente parte dell’antica Nuceria (odierna Nocera),
sono rappresentate dai resti di una villa rustica del I sec. a.C. - I sec. d.C., successivamente inglobati
nella cripta dell’abbazia di Santa Maria Maddalena in Armillis.
Alla stessa epoca appartiene anche un blocco marmoreo con raffigurazioni del dio Sarno, in cui è realizzata
la “fontana di San Nicola” o “fontana di Helvius” (dal nome del pretore di Nuceria, Publius Helvius, che la
fece realizzare). Il dio viene raffigurato sui diversi lati del blocco nelle due versioni iconografiche di giovane
e di uomo maturo, riferibili ai vari tratti del fiume Sarno che vanno dalla sorgente alla foce.
La fontana in marmo, connessa all’acquedotto, fornisce una datazione indiretta anche sull’epoca di realizzazione
del sistema di gallerie
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
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