1,721,002 research outputs found
X-linked dilated cardiomyopathy and the dystrophin gene.
No full textX-linked dilated cardiomyopathy (XLDC) represents a well known genetic disease, allelic to Duchenne and Becker muscular dystrophies and caused by dystrophin gene mutations. XLDC is a rare disease and only few families have been fully characterised. In several of them, the dystrophin mutations show a different pattern of expression in cardiac compared to skeletal muscle. In the families with the most severe cardiac phenotype, the cardiac muscle is usually unable to produce dystrophin, due to a specific effect that the mutation(s) have on the gene transcription in this tissue. The skeletal muscle escapes the dystrophic changes by maintaining dystrophin synthesis via exon skipping or alternative splicing that the heart is not able to put in place. In this paper we have reviewed the families with X-linked dilated cardiomyopathy reported so far; in addition we provided novel transcription data on two families we previously described. The aim of this review is to attempt a genotype-phenotype correlation and speculate on common pathogenic mechanisms underlying this disease
Transcription of the dystrophin gene in normal tissues and in skeletal muscle of a family with X-linked dilated cardiomyopathy
No full textWe recently described a family where a deletion of the dystrophin gene was associated with a severe dilated cardiomyopathy without skeletal muscle weakness. The deletion removed the muscle promoter region and the first muscle exon, but not the brain or Purkinje-cell promoters. Dystrophin was detected immunocytochemically in the skeletal muscle from this family, despite the fact that the deletion eliminated the transcriptional start site of the muscle isoform. In order to determine which promoter was driving dystrophin transcription in skeletal muscle of these individuals, we first evaluated the expression of the exon 1 of muscle, brain, and Purkinje-cell isoforms in normal human skeletal and cardiac muscles and in mouse brain and cerebellum. Our data indicate that, with the exception of minimal expression of the brain isoform, only the muscle isoform is significantly transcribed in skeletal muscle, whereas both the exon 1 muscle and brain isoforms are highly expressed in cardiac muscle. In contrast to what is observed in normal muscle, the skeletal muscle of our patients showed expression of both the brain and the Purkinje-cell isoforms. The overexpression, in skeletal muscle, of these two isoforms thus appears to be of crucial importance in preventing a myopathy in these affected males. The reason for the severe cardiomyopathy remains speculative, in the absence of dystrophin data on their heart. However, we have found in the 5' end of intron 1, a region deleted in our cases, regulatory sequences that might be of importance for dystrophin expression in various tissues. It is also possible that the deletion present in this family affects specifically one of the two dystrophin actin-binding domains
OCRL mutation analysis in Italian patients with Lowe syndrome
No full textThe oculocerebrorenal syndrome of Lowe (OCRL, also called OCRL1) is a rare X-linked
disorder characterized by major abnormalities of eyes, nervous system, and kidneys. The
gene responsible for OCRL was identified by positional cloning and encodes an inositol
polyphosphate-5-phosphatase. We performed the molecular analysis in 9 Italian patients and
26 relatives and we detected the mutations in all the examined patients. Eight mutations out
of nine had never been described and consisted of truncating mutations (frameshift,
nonsense, splice site and genomic deletion), and missense mutations. The mutations were
distributed in the second half of the gene as previously described in other populations. In
three cases the mutations were absent in the mothers confirming the occurrence of novel
mutations in this disorder. Our results on the Italian population are similar to the data
previously obtained in other populations
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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