1,721,069 research outputs found

    Oestrogen deficiency in men: where are we today?

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    The article deals with the role of estrogens in men according to the increasing evidence that the old view on the main role androgens in men and estrogens in females did not fully explain what happens in men with congenital estrogen deficienc

    Estrogen replacement therapy in a man with congenital aromatase deficiency: Effects of different doses of transdermal estradiol on bone mineral density and hormonal parameters

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    The effects of different doses of transdermal estradiol (TE) on bone mineral density (BMD) in a man with aromatase deficiency were evaluated. The study protocol was divided in the following four phases: phase 1, before estradiol treatment; phase 2, 50 mu g TE twice weekly for 6 months; phase 3, 25 mu g TE twice weekly for 9 months; and phase 4, 12.5 mu g TE twice weekly for 9 months. X-rays of hands, legs, and pelvis were performed, and BMD of the lumbar spine, hormonal parameters (LH, FSH, testosterone, and estradiol), and markers of bone turnover were determined during each phase. BMD in phase 1 was 0.933 g/cm(2) and increased to 1.051 and 1.173 g/cm(2) after 4 and 7 months of TE, respectively. In phase 3, BMD reached the maximum value (1.275 g/cm(2)). In phase 4, BMD decreased to 1.180 g/cm(2) and was 1.029 g/cm(2) at the end of the study protocol. A bilateral necrosis of femoral heads was also detected by x-ray films. In phase 1 serum testosterone was in the normal range, whereas serum estradiol was undetectable. During the 24-month period of treatment with TE (phases 2-4), estradiol was directly related to the amount of TE, whereas LH was inversely related to estradiol serum levels. Estradiol and gonadotropins reached optimal values only in phase 3, when FSH also was near normal; serum testosterone concentrations were normal in phases 3 and 4. This study confirms the role of estrogens in achieving and maintaining bone mineral content in the human male, providing further clinical tools useful in the management of bone loss in aromatase deficiency in the male, We suggest that the adequate substitutive dose of TE for maintaining both bone mass and normal estradiol serum levels in adult men with aromatase deficiency may be 25 mu g twice weekly (0.47 mu g/kg weekly)

    Role of estrogen on bone in the human male: insights from the natural models of congenital estrogen deficiency

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    The reports of congenital estrogen deficiency - notably, estrogen resistance and aromatase deficiency - have completely changed our knowledge on the role of estrogen on bone in males. Particularly, the bone changes at puberty, which were classically considered androgen-dependent, are now considered to be induced at least in part by estrogen action. Clinical cases of congenital estrogen deficiency have clearly demonstrated that the role of estrogens in epiphyseal closure, skeletal proportions and bone mineralization is crucial not only in women but also in men. In addition progress have been made in the treatment of such a rare disease even though further studies are needed to a definitive understanding of this issue. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved

    Estrogen resistance and aromatase deficiency

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    The chapter deals with the aspects of estrogen resistance and aromatase deficiency. In particular the role of serum estrogens in the control of gonadotropin feedback is reviewed

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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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