1,720,987 research outputs found
Thyrotropin secretion before and after ovariectomy in premenopausal women
Many studies have shown a physiological reduction in thyroid function with age in animals, and less clearly in humans, with an increase in the incidence of age-dependent clinical and subclinical hypothyroidism. Women are more subject to thyroid dysfunction than men. In postmenopausal women the sudden drop in estrogen levels may affect not only pituitary gonadotropins but also other pituitary hormones directly or indirectly involved in reproductive function. The response of thyrotropin to thyrotropin releasing hormone (TRH) has been shown to decrease with age and basal levels of thyrotropin have been found to be reduced in elderly subjects. In the present study we evaluated the response of thyrotropin to TRH before and after ovariectomy in premenopausal women and during estrogen therapy. The response of thyrotropin to TRH after ovariectomy was significantly less than before. Estrogen replacement therapy restored the thyrotropin response to TRH to pre-ovariectomy levels. This significant decrease in the thyrotropin response to TRH observed in surgical postmenopausal women may be explained by lower endogenous estradiol levels.
PMID: 8147238 [PubMed - indexed for MEDLINE
Going Beyond Counting First Authors in Author Co-citation Analysis
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
[Treatment of neurovegetative menopausal symptoms with a phytotherapeutic agent] Trattamento dei disturbi neurovegetativi della donna in menopausa con un preparato fitoterapico
BACKGROUND:
Menopausal symptoms include hot flushes, insomnia, nocturnal sweating, dizziness, headaches and palpitations. These symptoms reflect adaptation of the body to estrogen deprivation which affects various central neurotransmitters.
METHODS:
In this study, the efficacy has been tested of a plant product based on extracts of the leaves of Salvia officinalis (sage) and Medicago sativa (alfalfa) in the treatment of hot flushes in 30 menopausal women with these symptoms.
RESULTS:
Hot flushes and night sweating completely disappeared in 20 women: four women showed good improvement and the other six showed a reduction in symptoms. GnRH and TRH tests were performed in 8 women to evaluate TSH and Prl responses before and after 3 months of therapy. The plants product induced a significant increase in Prl and TSH response to TRH. Basal levels of estradiol, LH, FSH, Prl and TSH were unchanged.
CONCLUSIONS:
The product seams to have a central slight antidopaminergic action without side effects and is an effective agent in the treatment of menopausal symptom
Variations on the Author
“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
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
Low estrogen oral contraceptives and the hypothalamo-pituitary axis.
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Abstract
The hypothalamo-pituitary axis in a group of 10 women (17-25 years of age) taking low-dose-estrogen oral contraceptives (20μg ethinylestradiol (EE) + 150μg desogestrel) for at least 6 months was investigated. The subjects underwent the GnRH (50μg) and TRH (200μg) stimulation tests for the evaluation of LH, FSH, Prl, TSH and GH secretion. In the basal blood sample, E2, P, free T, A and SHBG levels were also determined. An elevation in LH response to GnRH was found, whereas FSH was inhibited. After TRH administration, the Prl response was the same in the oral contraceptive cycle as in the pretreatment cycle. Similar results were observed after TSH. Significantly, GH responded to TRH stimulation in the oral contraceptive cycles, but not in the pretreatment cycles. These results show that the new combination of 20μg EE and desogestrel blocks hypothalamic production of GnRH. The different response to GnRH of LH and FSH reveals a differentiated sensitivity to the oral contraceptive which seems to inhibit the pituitary FSH-secreting gonadotrope cells in particular. © 1991
Dispelling the Myths Behind First-author Citation Counts
We 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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