1,720,966 research outputs found
Ectopic Intrathyroidal Thymus in Children: A Long-Term Follow-Up Study
No full textBackground: Ectopic intrathyroidal thymus has recently been reported in children as a cause of surgery and/or invasive diagnostic procedures when mistaken for a thyroid nodule. Thymus has a unique appearance at ultrasound (US). Methods: We report a follow-up study (mean 34 months, range 6-84) performed by US on 9 children (5 females) with a mean age of 6.3 +/- 3.2 years with intrathyroidal thymic inclusions diagnosed by US as 'incidentalomas'. None has palpable nodules. Results: Intrathyroidal thymic inclusions appeared on US as a hypoechoic area, with regular linear or punctuate internal hyperechoic echoes. The 2 oldest patients (13 and 17 years) showed a regression in both size and hypoechogenicity of thymic inclusions over time - reflecting the normal thymic involution with advancing age. Conclusions: Indeed, the lack of progression seen in our 9 patients over a mean time of 34 months confirmed the substantially benign and self-limited nature of this process. The increasing use of thyroid ultrasonography in children may result in an increased detection of intrathyroidal thymic inclusions - an embryologic anomaly that should be considered in the differential diagnosis of thyroid nodules in children and adolescents. Copyright (C) 2010 S. Karger AG, Base
PROGRESSION OF PREMATURE THELARCHE TO CENTRAL PRECOCIOUS PUBERTY
No full textTo evaluate whether girls with premature thelarche progress to central precocious puberty (CPP) and to analyze their clinical and hormonal characteristics, we retrospectively examined 100 girls with premature thelarche who were followed for several years. Fourteen of the patients with characteristics diagnostic of premature thelarche (isolated breast development before age 8 years, bone age advancement within 2 SD of normal, normal growth velocity, follicle-stimulating hormone-predominant response to luteinizing hormone-releasing hormone) progressed during follow-up to precocious or early central puberty (progressive breast size increase, bone age acceleration, and significant decrease in predicted adult height). The chronologic age of this group of 14 girls was 5.1 +/- 2.0 years at the onset of premature thelarche and 7.8 +/- 0.6 years (mean +/- SD) after progression to central early or precocious puberty. Pelvic ultrasonography showed significant differences in measurements between the time of diagnosis of premature thelarche and progression to CPP. Nine of these patients required treatment, three with cyproterone acetate and six with luteinizing hormone-releasing hormone analogs, and all responded as expected for could be established that separated the 14 children who progressed to preconcious or early puberty from the 86 girls who did not. We conclude that premature thelarche is not always a self-limited condition and may sometimes accelerate the timing of puberty
Thyroid C-cell hyperplasia in an adolescent with neurofibromatosis type 1
No full textBackground: Subjects with neurofibromatosis type 1 (NF1) show an increased risk of endocrine tumors, especially pheochromocytoma, whereas thyroid C-cell hyperplasia (CCH) and medullary thyroid carcinoma (MTC) are very rare events described only in adult patients. Method. A case of CCH diagnosed in a 14-year-old girl affected with NF1 is reported. Calcitonin serum level after pentagastin was elevated (286 pg/ml). Genetic testing was performed in order to rule out mutations in the RET protooncogene. Result. No germline mutation previously reported in MEN2 was detected. Multifocal and bilateral CCH was demonstrated by immunohistochemistry. Conclusion: It is suggested that in such a genetic background of high risk for malignancy, CCH could be considered as an extremely rare condition likely preceding MTC. Copyright (C) 2002 S. Karger AG, Basel
High Prevalence of Antinuclear Antibodies in Children with Thyroid Autoimmunity
Full text linkBackground. Antinuclear antibodies (ANA) are a hallmark of many autoimmune diseases and can be detected many years before disease onset. Autoimmune thyroid diseases (AITD) are frequently associated with other organ-and non-organ-specific autoimmune disorders. Objectives. To assess the prevalence of ANA in pediatric patients with AITD and their clinical correlations. Methods. Ninety-three consecutive pediatric patients with AITD were enrolled (86 children with chronic lymphocytic thyroiditis and 7 with Graves' disease). ANA, anti-double DNA (anti-dsDNA) antibodies, anti-extractable nuclear antigen (anti-ENA), anti-cyclic citrullinated peptide antibodies (anti-CCP), and rheumatoid factor (RF) was obtained. Signs and symptoms potentially related to rheumatic diseases in children were investigated by a questionnaire. Results. ANA positivity was found in 66/93 children (71%), anti-ENA in 4/93 (4.3%), anti-dsDNA in 1/93 (1.1%), RF in 3/93 (3.2%), and anti-CCP in none. No significant differences were found between the ANA-positive and ANA-negative groups with respect to age, sex, L-thyroxine treatment, or prevalence of other autoimmune diseases. Overall, parental autoimmunity was found in 23%. Conclusions. ANA positivity was demonstrated in 71% of children with AITD. ANA positivity was not related to overt immune-rheumatic diseases. However, because the positivity of ANA can occur even many years before the onset of systemic autoimmune diseases, prospective studies are warranted
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
Cardiopulmonary response to exercise and cardiac assessment in patients with turner syndrome.
No full textTurner syndrome (TS) is a chromosomal disorder; however, little is known about the exercise tolerance of patients with this syndrome. The aim of the present study was to measure the maximal aerobic capacity and cardiac function using cardiopulmonary exercise testing and lung function tests and to evaluate the cardiac parameters using echocardiography in patients with TS and control subjects. A total of 50 women with TS (mean age 21.3 +/- 8.5 years) and 56 age-matched controls (mean age 21.1 +/- 3.7 years) were enrolled from the Pediatric Department of "Sapienza" University of Rome and underwent cardiopulmonary exercise testing, lung function testing, and echocardiography. The maximal oxygen uptake was lower in the patients with TS than in the controls (28.4 +/- 4.0 vs 35.6 +/- 6.2 ml/min/kg; p < 0.0001). Also, the forced expiratory volume in 1 second, expressed as a percentage of the predicted value, was greater in the patients with TS than in the controls (116.2 +/- 15.2% vs 102.8 +/- 4.8%, p < 0.0001). The patients with TS had a smaller left ventricle than did the controls. Tissue Doppler imaging revealed subclinical systolic and diastolic dysfunction in the left ventricle in those with TS but not in the controls. The left ventricular mass index was greater in the patients with TS than in the controls (38.6 +/- 9.3 vs 27.2 +/- 4.5 g/m(2.7), p < 0.0001). In conclusion, the patients with TS had a lower maximal aerobic capacity and exercise tolerance than did the controls. The anatomic and functional cardiac aspects were peculiar to those with TS and might represent a specific cardiac phenotype. (C) 2011 Published by Elsevier Inc. (Am J Cardiol 2011;107:1076-1082
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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