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Non cardiopatic and cardiopatic beta thalassemic patients: quantitative and qualitative cardiac iron deposition evaluation with MRI
No full textNon cardiopatic and cardiopatic beta thalassemic patients: quantitative and qualitative cardiac iron deposition evaluation with MRI
No full textPURPOSE: Cardiomyopathy is one of the major complications of b thalassaemia major as a result of transfusional iron overload. The aim of our study is to evaluate with MR if there is any difference of iron deposition signal intensity (SI) or distribution between non-cardiopathic and cardiopathic thalassaemic patients in order to establish if there is a relationship between cardiopathy and iron deposition.
MATERIALS AND METHODS: We studied 20 patients affected by b thalassaemia major, of whom 10 cardiopathic and 10 non-cardiopathic, and 10 healthy volunteers as control group. Serum ferritin and left ventricular ejection fraction were calculated in thalassaemic patients. All patients were examined using a 1.5 MR unit with ECG-gated GE cine-MR T2*-weighted, SE T1-weighted and GE T2*-weighted sequences. In all cases, using an adequate ROI, the myocardial and skeletal muscle signal intensity (SI), the myocardial/skeletal muscle signal intensity ratio (SIR) and the SI average of the myocardium and skeletal muscle were calculated for every study group. The qualitative evaluation of iron deposition distribution was independently performed by three radiologists who analyzed the extension, the site and the morphology of iron deposition on the MR images and reported their observations on the basis of a four-level rating scale: 0 (absent), 1 (limited), 2 (partial), 3 (widespread deposition). The result of quantitative and qualitative evaluations were analysed with statistical tests.
RESULTS: Cardiac iron deposition was found in 8/10 non-cardiopathic thalassaemic patients and in all cardiopathic thalassaemic patients. We noticed a significant SI difference (p>0.05) between the healthy volunteer control group and the thalassaemic patients with iron deposition, but no significant SI difference in iron deposition between non-cardiopathic and cardiopathic thalassaemic patients in the areas evaluated. The qualitative evaluation revealed a different distribution of iron deposition between the two thalassaemic groups, with more widespread distribution in cardiopathic patients.
CONCLUSIONS: We found cardiac iron deposition also in non-cardiopathic b thalassaemic patients and a qualitative difference in cardiac iron distribution between non-cardiopathic and cardiopathic patients. The qualitative evaluation of cardiac iron deposition was useful for an easier classification of the disease, bypassing the SI quantitative value which is affected by the extremely uneven distribution of iron deposition and by the sampling technique used. MR evaluation of non-cardiopathic thalassaemic patients may be useful to evaluate early iron deposition and to establish the most suitable chelation therapy
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
Lymphocyte subset reconstitution after HLA-identical placental blood transplantation (PBT) or PBT plus bone marrow transplantation (BMT) in three children with β-thalassemia major
No full textThe kinetics of circulating lymphoid cells were evaluated in three children suffering from β-thalassemia major after HLA-identical sibling placental blood transplant (PBT) in one patient and placental blood plus bone marrow transplantation (BMT) in two patients. Recovery of the main lymphocyte subsets, as determined by phenotype analysis of circulating PBMCs, was complete within 2 months after transplant. NK (CD56+) cells were the first to appear in peripheral blood, followed by T (CD3+, CD2+, CD7+) and B (CD19+) cells. Of the T lymphocytes, the CD8+ were the first to reconstitute, but recovery of CD4+ cells was also rapid and within 6 months these T cells reached normal values. The expression of CD57 by NK or T cells was slightly delayed. The evaluation of RA and RO isoform expression of the CD45 molecule showed a prevalence of the CD45RA antigen with a ratio of 2-3:1. In the PBT only patient, T cells expressing the CD45RO antigen prevailed in the early post-transplant period. Severe or chronic GVHD was not observed. This experience demonstrates that reconstitution of lymphocyte subsets is successful in genetic hematological diseases after transplantation of HLA-identical placental blood or placental blood plus bone marrow from healthy or heterozygous siblings
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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