1,720,986 research outputs found
High sensivity and specificity of denaturing high performance liquid chromatography (DHPLC) for mutation analysis of the FBN1 gene in patients with Marfan syndrome.
No full textHigh sensivity and specificity of denaturing high performance liquid chromatography (DHPLC) for mutation analysis of the FBN1 gene in patients with Marfan syndrome.
A. Mori 1 , S. Ansaldi 1 , M. Grasso 1 , A. Pilotto 1 , C. Lucchelli 1 , L.
Lanzarini 2 , M. Diegoli 3 , L. Tavazzi 2 , E. Arbustini 1 ;
1 Cardiovascular Pathol. and Molec. Diagn. - Res.Transplantation
Lab. , IRCCS Policlinico S.Matteo, Pavia, Italy, 2 Cardiology Division,
IRCCS Policlinico S.Matteo, Pavia, Italy, 3 Department of Pathology
- University of Pavia, Pavia, Italy.
Marfan syndrome is an autosomal dominant inherited disorder of the
connective tissue that principally involves the cardiovascular,ocular
and skeletal systems. The incidence is estimated to be 1:5000, with
25% sporadic cases. The leading cause of death is related to the
cardiovascular involvement, in particular aortic root dilatation and
rupture.
The disease is caused by alteration in FBN1 gene (65 exons, located
at 15q15-q21.1). Causal mutations are scattered throughout the gene
and are largely unique to individual families.
The FBN1 gene was analyzed in 29 unrelated patients suspected
to be affected by Marfan syndrome. To develop an efficient and
faster method capable of identify all possible mutations in this gene,
we introduced DHPLC technology in the analysis of 25 exons in
which mutations recur. We first analysed the FBN1 exons and exon-
flanking non coding regions gene coding regions with automated
sequencing of all 65 exons (ABI PE- 373 DNA Sequencer) to
identify mutations and polymorphisms. Then, DHPLC analysis
was carried out on the WaveTM DNA Fragment Analysis System
(Transgenomic, Cheshire, UK). DNA fragment elution profiles were
displayed using the Transgenomic WAVEMAKER-TM software.
Chromatograms were analysed and amplified fragments showing
alterations were re-confirmed by automated sequencing. Overall, by
direct sequencing we indentify 19 variants (14 in coding regions and
5 in intronic sequences). A corresponding number of heteroduplex
297 profiles was detected with DHPLC with 100% correspondence to the
variant-containing regions previously identified by direct sequencing.
Our results confirms that DHPLC is a highly sensitive and specific
technology for DNA sequence variant detection
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
Esame radiologico dello stomaco nei pazienti grandi obesi dopo Bypass Gastrico su ansa alla Roux
No full textIntroduzione - Obiettivi.
Valutare il ruolo dell’esame radiologico dello stomaco, eseguito con adeguate modalità tecniche, nel valutare l'anatomia post-chirurgica e nel rilevare le complicanze nei pazienti grandi obesi, dopo bypass gastrico su ansa alla Roux (RYGBP).
Materiale e metodi.
Da maggio 2004 a giugno 2007 abbiamo studiato 60 pazienti obesi sottoposti a RYGBP, di cui 44 (75%) femmine e 16 (25%) maschi,
con esame radiologico dello stomaco sottoposti a con peso medio di 130 kg (intervallo da 85 a 210 kg) ed età media di anni 36.
Nei controlli precoci tra IV e VII giornata postoperatoria abbiamo utilizzato mdc idrosolubile per os (Gastrografin), mentre i controlli tardivi sono stati eseguiti annualmente con solfato di bario.
Risultati.
L'esame radiologico ha messo in videnza nel controllo precoce 2 casi di edema dell'anastomosi gastro-digiunale, 2 casi di diletazione della tasca gastrica ed 1 fistola gastro-gastrica.
Nei controlli tardivi abbiamo evidenziato 3 ulcere della regione anastomotica, 1 caso di reflusso gastro-esofageo ed 1 angolazione della neotasca.
Abbiamo studiato inoltre l’incidenza annuale delle complicanze nei
controlli tardivi. L'indagine ha sempre descritto le caratteristiche morfo-volumetriche dello stomaco operato.
Discussione.
L'esame radiologico dello stomaco dopo RYGBP ha un ruolo fondamentale nel descrivere le caratteristiche morfo-volumetriche e rilevare le complicanze precoci e tardive ed indirizzare il trattamento delle stesse, per consentire una accettabile perdita di peso e delle patologie correlate all'obesità
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