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Modulation of endometrial redox balance during the menstrual cycle: Relation with sex hormones
No full textThis study aimed to evaluate the effects of changes in sex hormones occurring during the menstrual cycle on the redox balance and lipid peroxidation in normal human endometrial cells. Forty women, ages 21-41 yr, who were admitted to the Department of Gynecology and Obstetrics of the University of Bari for routine checkups or were treated for benign uterine disease, underwent endometrial biopsy and venipuncture. On the basis of histological examination, patients were allocated as follows: 10 in the early proliferative phase, 12 in the late proliferative phase, 8 in the early secretory phase, and 10 in the late secretory phase. LH, FSH (immunoradiometric essay), estradiol (E2), and progesterone (P(4)) (RIA) were determined in plasma samples. On the endometrial specimens, total glutathione (GSH), oxidized GSH (GSSG), malondialdehyde, and GSH peroxidase activity (GSH-Px) were determined. Significant cycle-dependent changes in endometrial GSH-Px (P < 0.0001), GSH (P < 0.001), and GSSG as a percentage of GSH (P < 0.0001) were observed. Malondialdehyde did not show significant differences. A linear regression model correlating sex hormone changes with redox indexes was performed. A significant positive correlation was observed between E2 and GSH-Px (r = 0.74; P = 0.0001), E2 and GSSG, as percentage of total (r = 0.84; P < 0.0001); a negative correlation was found between E2 and GSH (r = -0.57; P = 0.0001). No significant correlation was found between P(4) or FSH and oxidative balance. LH was found to be correlated with GSH-Px (r = 0.66; P = 0.0001) and GSSG as percentage of GSH (r = 0.5; P < 0.001). We conclude that the hormonal pattern is involved in maintaining the optimal redox balance in endometrium, mainly through modulation of GSH level and metabolism
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Modulation of endometrial redox balance during the menstrual cycle: relation with sex hormones.
No full textVariations on the Author
Get PDF“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
Brief hypoxia before normoxic reperfusion (post-conditioning) protects the heart against ischemia-reperfusion injury preventing mitochondria peroxyde production and glutathione depletion
No full textSeveral recent works have shown that a brief ischemia applied during the onset of reperfusion (postconditioning) is cardioprotective in different animal models and that the early minutes of reperfusion are critical to its cardioprotection. This effect has been related to prevention of oxidative stress, but mechanisms have not been clearly demonstrated. The present study tested the hypothesis that mitochondria play a central role in peroxide production and oxidative stress during reperfusion and are responsible for the protective effect of postconditioning. Isolated perfused rat hearts were subjected to complete global ischemia for 45 min and reperfused for 40 min. Normoxic group was reperfused with a Krebs-Henseleit solution with the preischemic pO2 level (600 mmHg); in the "hypoxic group," normoxic reperfusion was preceded by 3 min with 150 mmHg pO2. Reperfusion was stopped at 3 and 40 min. The rate of hydroperoxide production, GSH, GSSG, and carbonyl protein levels were measured in mitochondria at 3 min and at the end of reperfusion. GSH and GSSG were also measured in tissue. Hemodinamic function was monitored during the experiment. LVEDp increased and LVDp decreased in the normoxic group but not in the hypoxic group. The rate of mitochondrial peroxide production was higher in normoxic than in the hypoxic group 3 min after reperfusion and at its conclusion. Accordingly, GSH was oxidized in normoxic but not in hypoxic hearts. Mitochondria carbonyl proteins were significantly higher in normoxic than in the hypoxic group at the end of reperfusion. In this model, 1) hypoxic reperfusion at the onset of reperfusion reduces myocardial injury; 2) the major rate of mitochondrial peroxide production is 3 min after the onset of reperfusion; 3) cardioprotection of postconditioning correlates with reduced mitochondria peroxide production and prevention of GSH oxidation
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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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