1,720,984 research outputs found
A NOVEL MUTATION IN TRP1 GENE IN AN OCULAR CUTANEOUS ALBINISM PATIENT
No full textPurpose: To elucidate the molecular genetics defect of ocular cutaneous albinism.
Methods: One member of a family affected with ocular cutaneous albinism was studied to characterize the clinical phenotype and identify the disease-causing mutation.
The family members were examined with ophthalmoscopy, electroretinography, and Goldmann perimetry. Clinical features comprises congenital nystagmus, iris transillumination, foveal hypoplasia and fundus hypopgmentation. The complete coding sequence of the TRP1 gene, on chromosome 9, including the exon-intron boundaries, was amplified by PCR (polymerase chain reaction). Direct DNA sequencing analysis was performed and compared to TRP1 consensus sequences obtained from the National Centre for Biotechnology Information (NCBI).
Results: This analysis revealed a novel homozygous missense mutation, c.G869A on exon 4. This nucleotide variation leads to the aminoacid change cysteine to tyrosine (p.C290Y).
Conclusions: The lack of this variation on 50 healthy controls assessed by dHPLC analysis, confirmed that this protein change is likely the cause of the albino phenotype present in this patient
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
The long non-coding RNA Vax2os1 controls the cell cycle progression of photoreceptor progenitors in the mouse retina
No full textLong noncoding RNAs (lncRNAs) are emerging as regulators of many basic cellular pathways. Several lncRNAs are selectively expressed in the developing retina, although little is known about their functional role in this tissue. Vax2os1 is a retina-specific lncRNA whose expression is restricted to the mouse ventral retina. Here we demonstrate that spatiotemporal misexpression of Vax2os1 determines cell cycle alterations in photoreceptor progenitor cells. In particular, the overexpression of Vax2os1 in the developing early postnatal mouse retina causes an impaired cell cycle progression of photoreceptor progenitors toward their final committed fate and a consequent delay of their differentiation processes. At later developmental stages, this perturbation is accompanied by an increase of apoptotic events in the photoreceptor cell layer, in comparison with control retinas, without affecting the proper cell layering in the adult retina. Similar results are observed in mouse photoreceptor-derived 661W cells in which Vax2os1 overexpression results in an impairment of the cell cycle progression rate and cell differentiation. Based on these results, we conclude that Vax2os1 is involved in the control of cell cycle progression of photoreceptor progenitor cells in the ventral retina. Therefore, we propose Vax2os1 as the first example of lncRNA that acts as a cell cycle regulator in the mammalian retina during development
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
Access to cerebrospinal fluid in piglets via the cisterna magna: optimization and description of the technique.
No full textThe collection of cerebrospinal fluid is necessary in order to determine its composition. It can then be used to
diagnose various diseases. The aim of the study was to develop and optimize a technique for performing safe
centesis for the collection of cerebrospinal fluid in piglets and its injection through the cisterna magna. The
study was divided into three phases: (1) anatomical study of cadavers, (2) in vivo application of the technique
and (3) observation of recovery time. The proposed technique resulted in a safe puncture of the cisterna
magna. The authors identified and confirmed the correspondence of the crista occipitalis and the wings of the
atlas with the external landmarks on the cadaver by means of direct radiological visualization. The punctures
were performed successfully at the first attempt in 11 out of 12 anaesthetized piglets. The technique herein
described provides a reproducible safe and easy route for approaching the cisterna magna for cerebrospinal
fluid collection, drug administration and gene delivery
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
Gene therapy of inherited retinal degenerations: prospects and challenges.
No full textBecause of its favorable anatomical and immunological characteristics, the eye has been at the forefront of translational gene therapy. Dozens of promising proofs of concept have been obtained in animal models of inherited retinal degenerations (IRDs), and some of them have been relayed to the clinic. The results from the first clinical trials for a congenital form of blindness have generated great interest and have demonstrated the safety and efficacy of intraocular administrations of viral vectors in humans. However, this progress has also generated new questions and posed challenges that need to be addressed to further expand the applicability of gene therapy in the eye, including safe delivery of viral vectors to the outer retina, treatment of dominant IRDs as well as of IRDs caused by mutations in large genes, and, finally, selection of the appropriate IRDs and patients to maximize the efficacy of gene transfer. This review summarizes the strategies that are currently being exploited to overcome these challenges and drive the clinical development of retinal gene therapy
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