1,720,962 research outputs found
La Paraparesi spastica ereditaria in Sardegna: epidemiologia e studi di caratterizzazione genotipo-fenotipo
No full textObjective:The hereditary spastic paraplegias (HSP) constitute a clinically and genetically heterogeneous group of rare neurodegenerative disorders characterized by spastic gait with weakness in the legs and additional signs in "complicated" forms. This study aims to explore the epidemiological, clinical, and genetic variability of HSPs among Sardinians, a population of peculiar ethnicity.Methods:A population-based prevalence study was performed in north-western Sardinia between January 2000 and December 2010. Multiple sources were used for case ascertainment. Familial and sporadic cases were diagnosed according to generally accepted criteria, and clinical diagnoses were validated by expert neurological examination, clinical data and pedigree information were recorded and blood samples drawn for genetic testing.Results:On 31 December 2010, the total crude prevalence was 19.9 per 100,000 (95% CI: 18.4- 21.4). AD-HSP contributed to most of the burden with a prevalence of 17.5 per 100,000, with 76 % of the prevalent cases presenting the same largeSPASTdeletion, encompassing the 3'-UTR. Indeed, in some island inner areas, the geographic isolation favoured the spread of a SPG4 kindred from few founders. Most of patients presented a mild disability as well as the members of another SPG4 family in southern Sardinia, with a small gene deletion encompassing the 5'-UTR. A 17-year-old boy from the center of the island, presented the clinical features of Infantile Ascending Hereditary Spastic Paraplegia (IAHSP), and carried a novel mutation in theASL2.Conclusions:The prevalence of HSP among Sardinians is high compared with other Western European populations and the specific socio-demographic characteristics of Sardinians may account for this finding. The study of the genes flankingSPG4as disease modifying factors is worthwhile
Hereditary spastic paraparesis (hsp) associated with spast gene mutation (SPG4): analysis of a large series from Italy
No full text"Objectives: Hereditary Spastic Paraparesis (HSP) associated with SPAST gene mutation (SPG4) is by far the most frequent clinical form of pure autosomal dominant HSP (AD-HSP) with the typical features of onset in juvenile or early adult age, clinically exclusive signs of involvement of pyramidal tracts in the lower limbs, slowly progressive course with relative mild overall disability. However wide variability in age of onset and severity both intra- and interfamilial, occasional cognitive involvement, and incomplete penetrance of SPAST gene mutations have been repeatedly reported with no clear explanations (White et al., 2000; Namekawa et al. 2006). In order to better characterize these phenomena we analysed a large series of patients from Italy with genetically confirmed SPG4.. . Methods: For all available living family members complete clinical evaluation included neurological examination, Spastic Paraplegia rating Scale scoring system ( Schüle et al., 2006), Barthel index, careful reexamination of past medical history and existing clinical records. Results: 10 families have been studied, 109 patients, 53 males and 56 females. Mean age at onset, severity score of the disease, velocity progression have been determined and compared among male and female patients, within the same and among different families.. Conclusions: Our study represents so far the largest series of Italian patients with genetically confirmed SPG4. The obtained results allow an objective description of the phenomena of intra- and interfamilial variability.. . References:. 1.\tWhite KD, MBChB, Ince PG et al. Clinical and pathologic findings in hereditary spastic paraparesis with spastin mutation. Neurology 2000;55:89-94. 2.\tNamekawa M, Ribai P, Nelson I, Forlani S, Fellmann F, Goizet C, Depienne C, Stevanin G, Ruberg M, Dürr A, Brice A. SPG3A is the most frequent cause of hereditary spastic paraplegia with onset before age 10 years. Neurology, 2006; 66; 112-114. 3.\tSchüle R, Holland-Letz, Klimpe S, Kassubek J, Klopstock T, Mall V, Otto S, Winner B, Schöls L. The Spastic Paraplegia Rating Scale (SPRS): A reliable and valid measure of disease severity. Neurology, 2006; 67; 430-434. .
Infantile-onset ascending hereditary spastic paralysis: a case report and brief literature review.
No full textBACKGROUND:
Infantile-onset ascending hereditary spastic paralysis (IAHSP) is a rare, early-onset autosomal recessive motor neuron disease associated with mutations in ALS2.
AIM:
We studied a 17-year-old boy who had features of IAHSP. We also reviewed the current literature on ALS2-related syndromes.
METHODS:
Clinical and neuroimaging studies were performed. Blood DNA analyses were combined with mRNA studies in cultured skin fibroblasts.
RESULTS:
Like previously described cases, the patient presented with severe spastic paraparesis and showed rapid progression of paresis to the upper limbs. He also developed bulbar involvement and severe scoliosis during childhood. In blood DNA we identified a novel splice-site homozygous mutation in ALS2 (c.3836+1G > T), producing exon skipping in fibroblast mRNA and predicting premature protein truncation.
CONCLUSIONS:
This case adds to the allelic heterogeneity of IAHSP. Review of the pertinent literature indicates a fairly homogeneous clinical picture in IAHSP that should facilitate molecular confirmation and prevention of long-term complications
Bridging Over the Troubled Heterogeneity of SPG-Related Pathologies: Mechanisms Unite What Genetics Divide
No full textThe hereditary spastic paraplegias (HSP) are characterized by spastic gait with weakness in the legs and additional neurological or extra-neurological signs in "complicated" forms. The past two decades have witnessed major advances in our understanding of their molecular bases with the identification of a plethora of loci and the cloning of several SPG genes. Combined genetic and clinical information has permitted a modern, molecularly-driven classification and an improved diagnosis, with several new data on the possible disease mechanisms. Further heterogeneity will rapidly emerge with the diffusion of next-generation sequencing platforms and, under the shadow of common themes in the pathogenesis, new therapeutic options will likely emerge for a great number of patients
La Paraparesi spastica ereditaria in Sardegna: epidemiologia e studi di caratterizzazione genotipo-fenotipo
No full textObjective: The hereditary spastic paraplegias (HSP) constitute a clinically and genetically heterogeneous group of rare neurodegenerative disorders characterized by spastic gait with weakness in the legs and additional signs in "complicated" forms. This study aims to explore the epidemiological, clinical, and genetic variability of HSPs among Sardinians, a population of peculiar ethnicity.
Methods: A population-based prevalence study was performed in north-western Sardinia between January 2000 and December 2010. Multiple sources were used for case ascertainment. Familial and sporadic cases were diagnosed according to generally accepted criteria, and clinical diagnoses were validated by expert neurological examination, clinical data and pedigree information were recorded and blood samples drawn for genetic testing.
Results: On 31 December 2010, the total crude prevalence was 19.9 per 100,000 (95% CI: 18.4- 21.4). AD-HSP contributed to most of the burden with a prevalence of 17.5 per 100,000, with 76 % of the prevalent cases presenting the same large SPAST deletion, encompassing the 3'-UTR. Indeed, in some island inner areas, the geographic isolation favoured the spread of a SPG4 kindred from few founders. Most of patients presented a mild disability as well as the members of another SPG4 family in southern Sardinia, with a small gene deletion encompassing the 5'-UTR. A 17-year-old boy from the center of the island, presented the clinical features of Infantile Ascending Hereditary Spastic Paraplegia (IAHSP), and carried a novel mutation in the ASL2.
Conclusions: The prevalence of HSP among Sardinians is high compared with other Western European populations and the specific socio-demographic characteristics of Sardinians may account for this finding. The study of the genes flanking SPG4 as disease modifying factors is worthwhile.</br
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
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