1,721,166 research outputs found
Late onset MLD with normal nerve conduction associated with two novel missense mutations in the ASA gene.
No full textMetachromatic leukodystrophy (MLD) rarely has its clinical onset in young adults, with a combination of cognitive and behavioural symptoms and peripheral neuropathy. Here we present an exceptional case with very late onset at 42 years of age and no clinical or neurophysiological sign of peripheral neuropathy. Molecular analysis revealed compound heterozygosity for two novel missense mutations affecting conserved residues in the arylsulphatase A (ASA) sulphatase and carboxyterminal domains, resulting in an 89% loss of enzymatic activity. This case indicates that MLD needs to be considered in the differential diagnosis of very late onset white matter diseases, even if not accompanied by peripheral nerve involvement.Case ReportsJournal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe
The myelin basic protein gene is not a major susceptibility locus for multiple sclerosis in Italian patients.
No full textTo verify whether multiallelic polymorphism adjacent to the gene encoding for myelin basic protein is associated with or linked to multiple sclerosis in Italians, we studied 54 sporadic patients, 55 control subjects and 18 families with two or more affected individuals. Allelic typing was carried out by analysis of fragment length polymorphisms after DNA amplification by the polymerase chain reaction. The presence of linkage with the disease was tested according to either autosomal dominant or autosomal recessive modes of inheritance, and with or without the introduction of liability classes accounting for the age of the individuals. Furthermore sib-pair analysis was performed in 11 siblings. No evidence for association or linkage between the myelin basic protein gene polymorphism and multiple sclerosis was found. Our data indicate that in the Italian population the myelin basic protein gene does not play a major role in conferring genetic susceptibility to multiple sclerosis, and suggest that the latter is a heterogeneous phenomenon, possibly influenced by the different ethnic origin of the populations which have been investigated.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe
Regional localization by in situ hybridization of a human chromosome 9 marker tightly linked to the Friedreich's ataxia locus.
No full textIn order to determine the regional localization of the Friedreich's ataxia (FA) gene on chromosome 9, the DNA probe DR47 (D9S5), which detects a restriction fragment length polymorphism (RFLP) in tight linkage with the disease, was hybridized in situ to metaphase chromosomes. Our results enable the D9S5 locus to be assigned to the 9q12-q13 region, thus indicating that this is also the localization of the FA gene.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe
Mammalian single-stranded DNA binding proteins and heterogeneous nuclear RNA proteins have common antigenic determinants.
No full textAntibodies were raised in rabbit against a pure subset of calf thymus single-stranded DNA binding proteins (ssDBPs) and purified by affinity chromatography on antigen-Sepharose. In Western blot experiments these antibodies were shown to react to the same extent with the whole family of bovine ssDBPs, as well as with ssDBPs from HeLa cells. When used to stain total cell extracts from both calf thymus and HeLa cells the antibodies reacted only with bands corresponding to the ssDBPs and with a set of bands of higher molecular weight, whose electrophoretic pattern matched that of the 40S hnRNP core proteins. In effect we observed that purified 40S hnRNP core proteins from HeLa cells were strongly reactive with the antibodies. Moreover after partial tryptic digestion HeLa cells ssDBPs and hnRNPs produced immunoreactive fragments of the same molecular weight and isoelectric point. Extensive structural homologies can thus be evidenced between these two classes of proteins, which share the property of selective binding to single-stranded nucleic acids.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe
Single stranded DNA binding proteins derive from hnRNP proteins by proteolysis in mammalian cells.
No full textAs we have previously demonstrated, mammalian single stranded DNA binding proteins (ssDBP) and heterogeneous nuclear RNA binding proteins (hnRNP proteins) are antigenically and structurally related. In this paper we show that ssDBP are specific proteolytic products of hnRNP core proteins. Proteolysis can be observed in crude extract, both total and nuclear and is not inhibited by the most commonly used protease inhibitors. Such phenomenon can be observed in HeLa cells, human fibroblasts and calf thymus extracts. A trypsin-like protease that cleaves purified hnRNP proteins to give ssDBP of Mr = 24-28 Kd can be purified from HeLa cells. A precursor-product relationship can be established between hnRNP core proteins type A and an ssDBP of 24 Kd (UP1).Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe
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
Evidence of linkage between susceptibility to multiple sclerosis and HLA-class II loci in Italian multiplex families.
No full textTo verify whether multiallelic polymorphisms belonging to HLA class II genes are linked to multiple sclerosis (MS) in the Italian population, we studied 28 multiplex MS families originating from different areas of Italy. Allelic characterization was carried out by analysis of RFLPs and oligonucleotide typing. Evidence supporting the existence of linkage between MS susceptibility and the HLA class II loci DRB1, DQA1 and DQB1 was provided using two non-parametric tests, affected sib-pair analysis, and affected-pedigree-member (APM) analysis. The APM analysis also suggested the existence of genetic heterogeneity for the HLA class II loci and MS susceptibility in our series. Linkage disequilibrium between MS susceptibility and the haplotype DRB1*1501,DQA1*0102,DQB1*0602 was demonstrated by applying the transmission linkage disequilibrium test to our families. Finally, lod score analysis suggests that in our Italian families, MS susceptibility is conferred by HLA class II alleles according to a low-penetrance autosomal recessive mode of inheritance.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe
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
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