1,720,983 research outputs found

    Hypothalamic amenorrhea. Different patterns in the pulsatile secretion of LH during 24 hours and different responses to the stimulation test with GnRH

    No full text
    In 12 patients with hypothalamic amenorrhea and in 5 normal women, plasma gonadotropins (LH and FSH) were assayed before and 20, 30, 60, and 120 minutes after stimulation with 10 mcg GnRH i.v. and 24 hours after stimulation with 100 mcg GnRH i.v. In four patients and in controls the pulsatile secretion of LH was evaluated by blood sampling at 15 minute intervals for the 24-hour period. All patients showed different increases in LH after administration of 10 mcg and 100 mcg at 60 and 120 minutes. In two patients, with decreased LH pulse frequency, the gonadotropin increase is dose-dependent in respect to GnRH. In the other two, with normal LH pulse frequency, no difference was shown. In conclusion, this study suggests that the mechanism responsible for amenorrhea is due to reduced frequency of pulsatile GnRH secretion. However, in some patients LH pulse frequency was within the normal range. The double GnRH test (10 or 100 mcg) may be useful in distinguishing these different forms of amenorrhea.Abstract In 12 patients with hypothalamic amenorrhea and in 5 normal women, plasma gonadotropins (LH and FSH) were assayed before and 20, 30, 60, and 120 minutes after stimulation with 10 mcg GnRH i.v. and 24 hours after stimulation with 100 mcg GnRH i.v. In four patients and in controls the pulsatile secretion of LH was evaluated by blood sampling at 15 minute intervals for the 24-hour period. All patients showed different increases in LH after administration of 10 mcg and 100 mcg at 60 and 120 minutes. In two patients, with decreased LH pulse frequency, the gonadotropin increase is dose-dependent in respect to GnRH. In the other two, with normal LH pulse frequency, no difference was shown. In conclusion, this study suggests that the mechanism responsible for amenorrhea is due to reduced frequency of pulsatile GnRH secretion. However, in some patients LH pulse frequency was within the normal range. The double GnRH test (10 or 100 mcg) may be useful in distinguishing these different forms of amenorrhea

    Evaluation of circulating thyroid-specific transcripts as markers of thyroid cancer relapse

    No full text
    Circulating thyroid-specific transcripts have been suggested as potential molecular markers of residual or recurrent thyroid cancer. We assessed the accuracy of real-time RT-PCR-based detection of a panel of thyroid-specific markers, including TG, TPO, TSHR, NIS and PDS, in comparison with serum TG measurements in a series of 55 patients operated for differentiated thyroid cancer (DTC). Serum TG levels were higher in patients with residual thyroid tissue or metastatic cancer than in disease-free patients during thyroid hormone suppressive therapy (THST) and after stimulation with rhTSH (P < 0.05). Recombinant hTSH increased serum TG values in patients with tumor relapse (P < 0.05), but not in disease-free patients. This assay showed high specificity and good sensitivity in detecting tumor relapse (accuracy under THST = 81.4%; after rhTSH stimulation = 90.9%). TPO and TSHR mRNA, either under THST or after rhTSH, showed a significant correlation with disease status for molecular assays. Qualitative analysis of baseline and stimulated TG, NIS and PDS mRNA showed high sensitivity but low specificity in the prediction of thyroid cancer recurrence or metastases (accuracy under THST = 51%, 43% and 54%, respectively), whereas TPO and TSHR mRNA assays had higher specificity but low sensitivity, with accuracy under THST of 67% and 61%, respectively, that improved when these tests were combined. Our findings indicate that serum TG assay after TSH stimulation is the most accurate test for monitoring DTC. Combined measurements of TPO and TSHR mRNA levels during THST may represent a specific test for early detection of DTC relapse

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    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

    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 link
    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
    corecore