1,721,013 research outputs found
Renal complications in transfusion-dependent beta thalassaemia
No full textIncreased survival in patients with β thalassaemia major (TM) allowed for several morbidities to manifest. Renal manifestations of the disease and its treatment have been poorly evaluated. There is evidence, mainly from studies in the paediatric population, of tubular dysfunction and glomerular filtration rate abnormalities in this patient population. Long-term outcomes of these changes, however, have not been prospectively investigated. The pathogenesis of these abnormalities could be attributed to iron overload, too aggressive iron removal, and/or the underlying anaemia. These changes seem to be nonprogressive, resolve spontaneously in most part, or may require iron chelator dose modifications. Relative iron depletion may explain renal function changes attributed to chelation therapy; thus, sudden removal of iron or overchelation should be avoided. Future studies should aim to evaluate the natural history of kidney function in TM patients to help understand the mechanisms and long-term sequelae of the observed renal changes
Magnetic resonance evaluation of hepatic and myocardial iron deposition in transfusion-independent thalassemia intermedia compared to regularly transfused thalassemia major patients
No full textExtremely diverse phenotypes exist within the homozygous and compound heterozygote states for β-thalassemia. The terms thalassemia major (TM) and intermedia (TI) lack specific molecular correlates, but encompass a wide spectrum of clinical and laboratory abnormalities [1]. At the severe end of the spectrum are patients whose clinical course is characterized by profound anemia, who present to medical attention in the first year of life, and who subsequently require regular transfusions for survival, the condition known as TM. But many patients with inheritance of two mutant beta alleles have a milder illness, with a broad range of severity including, at least in early childhood, a virtually asymptomatic state. Patients in this group who present to medical attention in later childhood and remain largely transfusion free are said to have TI [1]. The pathophysiology, clinical consequences, and treatment of iron overload in regularly transfused patients with TM have been extensively studied; however, in transfusion-independent patients with TI data remain limited. Recent advances in the assessment of organ-specific iron deposition using magnetic resonance imaging (MRI) are promising and could potentially aid understanding the pathophysiology of iron in patients with TI
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
Optimal management of ß thalassaemia intermedia
No full textOur understanding of the molecular and pathophysiological mechanisms underlying the disease process in patients with β thalassaemia intermedia (TI) has substantially increased over the past decade. The hallmark of disease process in patients with TI includes ineffective erythropoiesis, chronic haemolytic anaemia, and iron overload. There are a number of options currently available for managing patients with TI including splenectomy, transfusion therapy, iron chelation therapy, modulation of fetal haemoglobin production, and several other agents targeting specific clinical complications. Limited studies assessed the efficacy and safety of these modalities; hence, there are currently no clear guidelines for managing patients with TI. Until solid evidence-based guidelines are available, individualised treatment should be entertained
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
Levels of growth differentiation factor-15 are high and correlate with clinical severity in transfusion-independent patients with β thalassemia intermedia
No full textTransfusion-independent patients with β thalassemia intermedia (TI) experience a variety of clinical complications attributed to the underlying ineffective erythropoiesis and subsequent anemia, hemolysis, and iron overload. Growth differentiation factor-15 (GDF-15) was recently investigated as a marker of ineffective erythropoiesis in several anemias. In this work, we evaluated GDF-15 levels in 55 patients with TI. The mean GDF-15 level was 25,197.8±16,208.9pg/ml which is lower than values reported for patients with thalassemia major, yet considerably higher than those reported in patients with other congenital and acquired anemias. GDF-15 levels were significantly higher in splenectomized compared to non-splenectomized patients and correlated with anemia, markers of iron overload, and a pre-defined clinical severity score. Further studies are needed to determine the practical utility of GDF-15 measurement and its potential to reflect the severity of the clinical course in TI patient
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