1,720,969 research outputs found
Variably Protease-Sensitive Prionopathy: a Novel Disease of the Prion Protein
Full text linkVariably protease-sensitive prionopathy (VPSPr) is a novel disease involving the prion protein (PrP) that has clinical similarities with non-Alzheimer's dementias especially frontotemporal dementia, diffuse Lewis body disease, and normal pressure hydrocephalus. VPSPr can be distinguished from sporadic Creutzfeldt-Jakob disease (sCJD) especially for the characteristics of the abnormal PrP. Furthermore, although VPSPr like sCJD affects patients with the three PrP genotypes as determined by the common methionine/valine polymorphism, the allelic prevalence is very different in the two diseases. These findings suggest that VPSPr is basically different from classical prion diseases such as sCJD being perhaps more akin to other neurodegenerative dementia
Coexistence of Both PrPSc Type 1 and 2 in sCJD: Does it Affect the Phenotype?
No full textIn sporadic Creutzfeldt-Jakob disease (sCJD) five phenotypically distinct subtypes
have been identified based on the methionine (M)/valine (V) polymorphic genotype of
codon 129 and two PK-resistant scrapie prion protein (PrPSc) types, which migrate in
gel to either 21 kDa (PrPSc type 1) or 19 kDa (PrPSc type 2). sCJD is characterized by
phenotypic heterogeneity. The co-existence of both PrPSc types has recently been
reported and may complicate the diagnosis.
In the present study we analyze the distribution of the two PrPSc types in various brain
areas as well as the PrPSc resistance to PK digestion using a rigorous procedure
according to Notari et al [Human PrPSc “Typing” pitfalls associated with the use of
type 1 selective antibodies combined with relative inefficient hydrolysis of PrPSc by
proteinase K, poster presentation, NeuroPrion 2006, Torino], with the intent of
assessing the co-occurrence of fully PK-resistant PrPSc types 1 and 2 in a ratio of
50:50 or 60:40 while ascertaining that intermediate fragments are completely digested.
We are studying the effect of the co-existence of the two PrPSc types, which occurs
in either the same or different brain regions, on the sCJD disease phenotype by
examining clinical history and neuropathological changes
A comparative blind study between skin biopsy and seed amplification assay to disclose pathological α-synuclein in RBD
No full textTo compare the diagnostic accuracy of the immunofluorescence (IF) technique and aSyn-seed amplification assay (aSyn-SAA) of skin and cerebrospinal fluid (CSF) in disclosing pathological α-syn in idiopathic idiopathic REM sleep behavior disorder (iRBD) as early phase of a synucleinopathy. We prospectively recruited 41 patients with iRBD and 40 matched clinical controls including RBD associated with type 1 Narcolepsy (RBD-NT1, 21 patients), iatrogenic causes (2 pt) or OSAS (6 pt) and 11 patients with peripheral neuropathies. IF from samples taken by skin biopsy and aSyn-SAA from skin and CSF samples were analysed blinded to the clinical diagnosis. IF showed a good diagnostic accuracy (89%) that was lower in the case of skin and CSF-based aSyn-SAA (70% and 69%, respectively) because of a lower sensitivity and specificity. However, IF showed a significant agreement with CSF aSyn-SAA. In conclusion, our data may favor the use of skin biopsy and aSyn-SAA as diagnostic tools for a synucleinopathy in iRBD
phenotypic heterogeneity in Creutzfeldt-Jakob disease associated with a new prion protein mutation
No full text
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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