217 resultados para endometrium


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Ovarian carcinomas are thought to arise in the ovarian surface epithelium (OSE). Although this tissue forms a simple epithelial covering on the ovarian surface, OSE cells exhibit some mesenchymal characteristics and contain little or no E-cadherin. However, E-cadherin is present in metaplastic OSE cells that resemble the more complex epithelia of the oviduct, endometrium and endocervix, and in primary epithelial ovarian carcinomas. To determine whether E-cadherin was a cause or consequence of OSE metaplasia, we expressed this cell-adhesion molecule in simian virus 40-immortalized OSE cells. In these cells the exogenous E-cadherin, all three catenins, and F-actin localized at sites of cell–cell contact, indicating the formation of functional adherens junctions. Unlike the parent OSE cell line, which had undergone a typical mesenchymal transformation in culture, E-cadherin-expressing cells contained cytokeratins and the tight-junction protein occludin. They also formed cobblestone monolayers in two-dimensional culture and simple epithelia in three-dimensional culture that produced CA125 and shed it into the culture medium. CA125 is a normal epithelial-differentiation product of the oviduct, endometrium, and endocervix, but not of normal OSE. It is also a tumor antigen that is produced by ovarian neoplasms and by metaplastic OSE. Thus, E-cadherin restored some normal characteristics of OSE, such as keratin, and it also induced epithelial-differentiation markers associated with weakly preneoplastic, metaplastic OSE and OSE-derived primary carcinomas. The results suggest an unexpected role for E-cadherin in ovarian neoplastic progression.

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The placenta contains several types of feto-maternal interfaces where zygote-derived cells interact with maternal cells or maternal blood for the promotion of fetal growth and viability. The genetic factors regulating the interactions between different cell types within feto-maternal interfaces and the relative contributions of the maternal and zygotic genomes are poorly understood. Genomic imprinting, the epigenetic process responsible for parental origin-dependent functional differences between homologous chromosomes, has been proposed to contribute to these events. Previous studies showed that mouse conceptuses with an absence of imprinted differences between the two copies of chromosome 12 (upon paternal inheritance of both copies) die late in gestation and have a variety of defects, including placentomegaly. Here we examined the role of chromosome 12 imprinting in these placentae in more detail. We show that the spatial interactions between different cell types within feto-maternal interfaces are defective and identify abnormal behaviors in both zygote-derived and maternal cells that are attributed to the genome of the zygote but not the mother. These include compromised invasion of the maternal decidualized endometrium and the central maternal artery situated within it by zygote-derived trophoblast, abnormalities in the wall of the central maternal artery, and defects within the zygote-derived cellular layer of the labyrinth, which is in direct contact with maternal blood. These findings demonstrate multiple roles for chromosome 12 imprinting in the placenta that have not previously been associated with imprinting effects. They provide insights into the function of imprinting in placental development and have evolutionary and clinical implications.

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The composite transcription factor activating protein 1 (AP-1) integrates various mitogenic signals in a large number of cell types, and is therefore a major regulator of cell proliferation. In the normal human endometrium, proliferation and differentiation alternate in a cyclic fashion, with progesterone being largely implicated in the latter process. However, the effects of progesterone and the progesterone receptor (hPR) on AP-1 activity in the human endometrium are not known. To address this issue, HEC-1-B endometrial adenocarcinoma cells, which are devoid of hPR, were transfected with luciferase reporter constructs driven by two different AP-1-dependent promoters. Unexpectedly, cotransfection of hPR caused a marked induction of luciferase activity in the absence of ligand on both promoters. The magnitude of this induction was similar to that observed in response to the phorbol ester TPA. Addition of ligand reversed the stimulating effect of the unliganded hPR on AM activity in these cells. These effects were specific for hPR, and were not observed with either human estrogen receptor or human glucocorticoid receptor. Furthermore, they strictly depended on the presence of AP-1-responsive sequences within target promoters. Finally, the described effects of hPR on AP-1 activity were shown to be cell-type specific, because they could not be demonstrated in SKUT-1-B, JEG-3, and COS-7 cells. To our knowledge this is the first report of an unliganded steroid receptor stimulating AP-1 activity. This effect and its reversal in the presence of ligand suggest a novel mechanism, through which hPR can act as a key regulator of both proliferation and differentiation in the human endometrium.

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Using RNA (Northern) blot hybridization and reverse transcription-PCR, we demonstrate that the brain-type cannabinoid receptor (CB1-R) mRNA, but not the spleen-type cannabinoid receptor (CB2-R) mRNA, is expressed in the mouse uterus and that this organ has the capacity to synthesize the putative endogenous cannabinoid ligand, anandamide (arachidonylethanolamide). The psychoactive cannabinoid component of marijuana--delta 9-tetrahydrocannabinol (THC)--or anandamide, but not the inactive and nonpsychoactive cannabidiol (CBD), inhibited forskolin-stimulated cyclic AMP formation in the mouse uterus, which was prevented by pertussis toxin pretreatment. These results suggest that uterine CB1-R is coupled to inhibitory guanine nucleotide-binding protein and is biologically active. Autoradiographic studies identified ligand binding sites ([3H]anandamide) in the uterine epithelium and stromal cells, suggesting that these cells are perhaps the targets for cannabinoid action. Scatchard analysis of the binding of [3H]WIN 55212-2, another cannabinoid receptor ligand, showed a single class of high-affinity binding sites in the endometrium with an apparent Kd of 2.4 nM and Bmax of 5.4 x 10(9) molecules per mg of protein. The gene encoding lactoferrin is an estrogen-responsive gene in the mouse uterus that was rapidly and transiently up-regulated by THC, but not by CBD, in ovariectomized mice in the absence of ovarian steroids. This effect, unlike that of 17 beta-estradiol (E2), was not influenced by a pure antiestrogen, ICI 182780, suggesting that the THC-induced uterine lactoferrin gene expression does not involve estrogen receptors. We propose that the uterus is a new target for cannabinoid ligand-receptor signaling.

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Metriti ed endometriti sono le patologie maggiormente responsabili delle perdite economiche negli allevamenti bovini da latte, specialmente nel periodo successivo al parto. Mentre le metriti coinvolgono e si sviluppano in tutto l’utero e sono caratterizzate dalla presenza di sintomi sistemici, le endometriti consistono in una infiammazione che riguarda il solo endometrio, con la presenza di perdite purulente, distruzione della superficie epiteliale, congestione vascolare, edema stromale ed accumulo di linfociti e plasmacellule. Queste patologie, inoltre, possono causare, disfunzione ovarica, con conseguente infertilità e riduzione sia dell’efficienza riproduttiva della vacca sia della produzione stessa di latte. Nonostante queste malattie siano, nella maggior parte dei casi, correlate all’instaurarsi di infezioni batteriche, che possono subentrare nell’utero direttamente durante il parto, il ruolo di alcuni virus nello sviluppo di queste patologie è stato recentemente approfondito e la correlazione tra l’ Herpesvirus Bovino 4 e l’insorgere di metriti ed endometriti è stata dimostrata. L’ Herpesvirus Bovino 4 (BoHV-4) è un gamma-herpesvirus ed il suo genoma è costituito da una molecola lineare di DNA a doppio filamento con una struttura genomica di tipo B, caratterizzata dalla presenza di un’unica lunga sequenza centrale (LUR) fiancheggiata da multiple sequenze poli-ripetute (prDNA). BoHV-4 è stato isolato sia da animali sani sia da animali con differenti patologie, tra cui malattie oculari e respiratorie, ma soprattutto da casi di metriti, endometriti, vaginiti o aborti. Generalmente, il ruolo svolto dal virus in questo tipo di patologie è associato alla compresenza di altri tipi di patogeni, che possono essere virus, come nel caso del Virus Della Diarrea Virale Bovina (BVDV), o più frequentemente batteri. Usualmente, l’iniziale difesa dell’endometrio bovino nei confronti dei microbi si fonda sul sistema immunitario innato e l’attivazione di specifici recettori cellulari determina la sintesi e la produzione di citochine e chemochine pro infiammatorie, che possono essere in grado di modulare la replicazione di BoHV-4. Il genoma di BoHV-4 possiede due principali trascritti per i geni Immediate Early (IE), trai quali ORF50/IE2 è il più importante ed il suo prodotto, Rta/ORF50, è fortemente conservato tra tutti gli Herpesvirus. Esso è responsabile della diretta trans-attivazione di numerosi geni virali e cellulari e può essere modulato da differenti stimoli extracellulari. Precedentemente è stato dimostrato come il TNF-, prodotto dalle cellule stromali e dai macrofagi all’interno dell’endometrio, in conseguenza ad infezione batterica, sia in grado di aumentare la replicazione di BoHV-4 attraverso l’attivazione del pathway di NFkB e direttamente agendo sul promotore di IE2. Per queste ragioni, è risultato di forte interesse investigare quali potessero essere, invece, i fattori limitanti la replicazione di BoHV-4. In questo lavoro è stata studiata la relazione tra cellule endometriali stromali bovine infettate con l’Herpesvirus Bovino 4 e l’interferon gamma (IFN-) ed è stata dimostrata la capacità di questa molecola di restringere la replicazione di BoHV-4 in maniera IDO1 indipendente ed IE2 dipendente. Inoltre, la presenza di alcuni elementi in grado di interagire con l’ IFN-γ, all’interno del promotore di IE2 di BoHV-4, ha confermato questa ipotesi. Basandoci su questi dati, abbiamo potuto supporre l’esistenza di uno stretto vincolo tra l’attivazione dell’asse dell’interferon gamma e la ridotta replicazione di BoHV-4, andando a porre le basi per una nuova efficiente cura e prevenzione per le patologie uterine. Poiché il meccanismo corretto attraverso il quale BoHV-4 infetta l’endometrio bovino non è ancora ben compreso, è stato interessante approfondire in maniera più accurata l’interazione presente tra il virus ed il substrato endometriale, analizzando le differenze esistenti tra cellule infettate e non, in termini di espressione genica. Basandoci su dati preliminari ottenuti attraverso analisi con RNA sequencing (RNAseq), abbiamo visto come numerosi geni risultino over-espressi in seguito ad infezione con BoHV-4 e come, tra questi, la Metalloproteasi 1 sia uno dei più interessanti, a causa delle sue possibili implicazioni nello sviluppo delle patologie dell’endometrio uterino bovino. Successive analisi, effettuate tramite westernblotting e real time PCR, sono state in grado di confermare tale dato, sottolineando l’efficacia di un nuovo approccio sperimentale, basato sul RNAseq, per lo studio dell’insorgenza delle patologie.

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O sistema imunológico materno desempenha um papel importante no estabelecimento da gestação e desenvolvimento de concepto até início do parto. A hipótese deste projeto é que há um recrutamento de células Tγδ para o endométrio ao longo da gestação que expressam citocinas que favorecem o estabelecimento e manutenção da tolerância materna a antígenos fetais durante a gestação em bovinos. Experimento I Para estudar a dinâmica populacional das células do sistema imune no sangue periférico de não lactantes não prenhes (NLNP), vacas lactantes no 1º trimestre e vacas no 3º trimestre da gestação, as PBMCs foram separadas por gradiente de densidade de Ficoll, seguido por protocolo de imunocitoquímica e analisadas em citômetro de fluxo para os anticorpos CD3+, CD4+, CD8+, CD14+, CD25+ e WC1+. As células analisadas tanto na região de linfócitos quanto na região de monócitos, não apresentaram diferença significativa entre os grupos analisados. Experimento II Para análise do perfil de expressão gênica das células Tγδ, foram coletadas amostras de sangue de vacas no 1º trimestre da gestação, vacas lactantes não prenhes (LNP) e vacas não lactantes não prenhes (NLNP). As células mononucleares foram separadas por gradiente de densidade de Ficoll e células Tγδ foram analisadas quanto ao perfil de citocinas por qRT-PCR para os genes IFNG; IL10; IL15; IL17; IL18; IL1B; IL4; IL-6; ISG15; PFR; TGFB2 e TNFA. A análise de expressão gênica mostrou tendência no aumento na expressão de IL1B, IL6 e TGFB2 em células PBMC em vacas NLNP quando comparado com vacas LNP e no 1º trimestre da gestação, enquanto que os outros genes analisados não apresentaram diferença significativa. Experimento III Fragmentos de endométrio, provenientes de abatedouro, foram coletados de vacas em 1º trimestre (33 a 35 dias de gestação), 2º trimestre (143 a 182 dias de gestação) e 3º trimestre de gestação (228 a 247 dias de gestação). Cortes congelados foram imunolocalizados e quantificados para as células do sistema imune CD3+, CD4+, CD8+, CD14+, CD18+, CD25+, CD62L+ e WC1+ por imunofluorescência. Nossos estudos mostraram aumento das células CD25+ e CD62L+ no endométrio no início da gestação. No meio da gestação, há um aumento das células WC1+ e CD14+. No final da gestação, observamos o aumento de CD14+, CD25+, CD18+ e CD62L+. Em suma, nossos dados sugerem que a modulação do sistema imune materno é específica para cada estágio da gestação, sendo que no início da gestação há um envolvimento de células T ativadas (CD25+) provavelmente para o estabelecimento de uma resposta ativa para tolerância dos antígenos fetais. Já no meio da gestação, há um recrutamento massivo de células Tγδ para o endométrio gravídico provavelmente para manter um microambiente de tolerância para o desenvolvimento fetal e no final da gestação células efetoras como macrófagos são recrutadas para o endométrio para auxiliar no processo do parto e involução uterina.

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Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

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Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

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Aims The major aims of the study were to compare the safety of a continuous low-dose estradiol-releasing vaginal ring (ESTring) to that of a vaginal estradiol tablet (Vagifem®) on the endometrium and the relief of subjective symptoms and signs of urogenital estrogen deficiency. Quality of life and acceptability of treatment delivery were also assessed. Study design A prospective, randomized study in which women were assigned in a 2: 1 ratio to ESTring and Vagifem and followed for 12 months. The primary endpoint was endometrial safety, based on the results of ultrasound measurement of endometrial thickness and a progestogen challenge test at baseline and week 48. Efficacy was determined by subjective assessment of urogenital estrogen deficiency symptoms at baseline and weeks 3, 12, 24, 36 and 48 and assessment of signs of vaginal epithelial atrophy by the clinician at baseline, 12 and 48 weeks. In addition, pelvic floor strength, vaginal cytological evaluation and pH, bacteruria and patient acceptability were assessed. Quality of life was assessed using a menopause-specific quality-of-life questionnire and a 2-day bladder diary at baseline and 12 and 48 weeks. The comparability of the two groups was assessed using ANOVA, χ(2) or Fisher's exact tests. Results A total of 126 women were randomized to ESTring and 59 to Vagifem. There was no statistical difference between the groups in the alleviation of symptoms and signs of urogenital estrogen deficiency. Maturation indices increased in both groups, from generally atrophic at baseline to proliferative or highly proliferative at 48 weeks. After 48 weeks of treatment, there was no statistically significant difference in endometrial thickness between the two groups. A statistically smaller proportion of bleeding/spotting occurred in the ESTring group (n = 0) compared to the Vagifem users (n = 4). Estradiol and total estrone serum levels increased during treatment in both groups but remained within the normal postmenopausal range. General health status in both groups was unchanged but the urogenital component of health burden was significantly improved in both groups. Bladder diary variables showed no differences between treatment groups. Conclusion Equivalent endometrial safety and efficacy in the relief of the symptoms and signs of urogenital estrogen deficiency were demonstrated for the 12 months' use of a low-dose estradiol-releasing vaginal ring and a vaginal estradiol tablet.

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Tamoxifen is a known hepatocarcinogen in rats and is associated with an increased incidence of endometrial. cancer in patients. One mechanism for these actions is via bioactivation, where reactive metabolites are generated that are capable of binding to DNA or protein. Several metabolites of tamoxifen have been identified that appear to predispose to adduct formation. These include alpha-hydroxytamoxifen, alpha,4-dihydroxytamoxifen, and alpha-hydroxy-N-desmethyltamoxifen. Previous studies have shown that cytochrome P450 (P450) enzymes play an important role in the biotransformation of tamoxifen. The aim of our work was to determine which P450 enzymes were capable of producing a-hydroxylated metabolites from tamoxifen. When tamoxifen (18 or 250,mu M) was used as the substrate, P450 3A4, and to a lesser extent, P450 2D6, P450 2B6, P450 3A5, P450 2C9, and P450 2C19 all produced a metabolite with the same HPLC retention time as alpha-hydroxytamoxifen at either substrate concentration tested. This peak was well-separated from 4-hydroxy-N-desmethyltamoxifen, which eluted substantially later under the chromatographic conditions used. No alpha,4-dihydroxytamoxifen was detected in incubations with any of the forms with tamoxifen as substrate. However, when 4-hydroxytamoxifen (100,mu M) was used as the substrate, P450 2B6, P450 3A4, P450 3A5, P450 1B1, P450 1A1, and P450 2D6 all produced detectable concentrations of a,4-dihydroxytamoxifen. These studies demonstrate that multiple human P450s, including forms found in the endometrium, may generate reactive metabolites in women undergoing tamoxifen therapy, which could subsequently play a role in the development of endometrial cancer.

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Endometriosis is a common gynecological disease that affects up to 10% of women in their reproductive years. It causes pelvic pain, severe dysmenorrhea, and subfertility. The disease is defined as the presence of tissue resembling endometrium in sites outside the uterus. Its cause remains uncertain despite 150 years of hypothesis-driven research, and thus the therapeutic options are limited. Disease predisposition is inherited as a complex genetic trait, which provides an alternative route to understanding the disease. We seek to identify susceptibility loci, using a positional-cloning approach that starts with linkage analysis to identify genomic regions likely to harbor these genes. We conducted a linkage study of 1,176 families ( 931 from an Australian group and 245 from a U. K. group), each with at least two members-mainly affected sister pairs-with surgically diagnosed disease. We have identified a region of significant linkage on chromosome 10q26 ( maximum LOD score [MLS] of 3.09; genomewide P = .047) and another region of suggestive linkage on chromosome 20p13 MLS p 2.09). Minor peaks with MLS > 1.0) were found on chromosomes 2, 6, 7, 8, 12, 14, 15, and 17. This is the first report of linkage to a major locus for endometriosis. The findings will facilitate discovery of novel positional genetic variants that influence the risk of developing this debilitating disease. Greater understanding of the aberrant cellular and molecular mechanisms involved in the etiology and pathophysiology of endometriosis should lead to better diagnostic methods and targeted treatments.

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Angiogenesis is an essential component of endometrial repair and regeneration following menses. Perturbation of this process is associated with menorrhagia, a common gynecological disorder that results in excessive menstrual bleeding. Angiopoietin-1 (Ang-1) promotes vascular maturation via the Tie-2 receptor, while angiopoietin-2 (Ang-2) is its natural antagonist that destabilizes vessels and initiates neovascularization in the presence of vascular endothelial growth factor. To test the hypothesis that menorrhagia arises as a result of poor signal for vascular maturation, we have examined the expression of Ang-1, Ang-2, and Tie-2 in endometrium throughout the menstrual cycle from 30 normal women and 28 patients with menorrhagia. Ribonuclease protection assay and Western blot analysis showed Ang-2 expression was consistently higher than Ang-1 in normal endometrium throughout the cycle. However, with menorrhagia Ang-1 mRNA and protein were not detected or down-regulated, while Ang-2 was observed at similar levels in both normal and menorrhagic endometrium resulting in a greater than a 50% decrease in the ratio of Ang-1 to Ang-2 protein. In situ hybridization and immunohistochemical studies supported these findings and revealed cyclical changes in the expression of Ang-1 and Ang-2. These results suggest that the angiopoietin/Tie-2 system promotes vascular remodeling in endometrium and loss of normal Ang-1 expression may contribute to the excessive blood loss observed in menorrhagia.

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The presence of the conceptus in uterine cavity necessitates an elaborate network of interactions between the implanting embryo and a receptive endometrial tissue. We believe that embryo-derived signals play an important role in the remodeling and the extension of endometrial receptivity period. Our previous studies provided original evidence that human Chorionic Gonadotropin (hCG) modulates and potentiates endometrial epithelial as well as stromal cell responsiveness to interleukin 1 (IL1), one of the earliest embryonic signals, which may represent a novel pathway by which the embryo favors its own implantation and growth within the maternal endometrial host. The present study was designed to gain a broader understanding of hCG impact on the modulation of endometrial cell receptivity, and in particular, cell responsiveness to IL1 and the acquisition of growth-promoting phenotype capable of receiving, sustaining, and promoting early and crucial steps of embryonic development. Our results showed significant changes in the expression of genes involved in cell proliferation, immune modulation, tissue remodeling, apoptotic and angiogenic processes. This points to a relevant impact of these embryonic signals on the receptivity of the maternal endometrium, its adaptation to the implanting embryo and the creation of an environment that is favorable for the implantation and the growth of this latter within a new and likely hostile host tissue. Interestingly our data further identified a complex interaction between IL1 and hCG, which, despite a synergistic action on several significant endometrial target genes, may encompass a tight control of endogenous IL1 and extends to other IL1 family members.

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Spontaneous fetal loss (25-40%) leading to decrease in litter size is a significant concern to the pork industry. A deficit in the placental vasculature has emerged as one of the important factors associated with fetal loss. During early pig pregnancy, the endometrium becomes enriched with immune cells recruited by conceptus-derived signals including specific chemokine stimuli. These immune cells assist in various aspects of placental development and angiogenesis. Recent evidence suggests that microRNAs (miRNAs: small non-coding RNAs that regulate gene expression) regulate immune cell development and their functions. In addition, intercellular communication including exchange of biomolecules (e.g. miRNAs) between the conceptus and endometrium regulate key developmental processes during pregnancy. To understand the biological significance of immune cell enrichment, regulation of their functions by miRNAs and transfer of miRNAs across the maternal fetal-interface, we screened specific sets of chemokines and pro- and anti-angiogenic miRNAs in endometrial lymphocytes (ENDO LY), endometrium, and chorioallantoic membrane (CAM) isolated from conceptus attachment sites (CAS) during early, gestation day (gd)20 and mid-pregnancy (gd50). We report increased expression of selected chemokines including CXCR3 and CCR5 in ENDO LY and CXCL10, CXCR3, CCL5, CCR5 in endometrium associated with arresting CAS at gd20. Some of these differences were also noted at the protein level (CXCL10, CXCR3, CCL5, and CCR5) in endometrium and CAM. We report for the first time significant differences for miRNAs involved in immune cell-derived angiogenesis (miR-296-5P, miR-150, miR-17P-5P, miR-18a, and miR-19a) between ENDO LY associated with healthy and arresting CAS. Significant differences were also found in endometrium and CAM for some miRNAs (miR-17-5P, miR-18a, miR-15b-5P, and miR-222). Finally, we confirm that placenta specific-exosomes contain proteins and 14 select miRNAs including miR-126-5P, miR-296-5P, miR-16, and miR-17-5P that are of relevance to early implantation events. We further demonstrated the bidirectional exosome shuttling between porcine trophectoderm cells (PTr2) and porcine aortic endothelial cells (PAOEC). PTr2-derived exosomes were able to modulate the endothelial cell proliferation that is crucial for the establishment of pregnancy. Our data unravels the selected chemokines and miRNAs associated with immune cell-regulated angiogenesis and reconfirm that exosome mediated cell-cell communication opens-up new avenues to understand porcine pregnancy.

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AZEVEDO, George Dantas de et al. Raloxifene therapy does not affect uterine blood flow in postmenopausal women: a transvaginal Doppler study. Maturitas, Amsterdam, v.47, n.3, p.195-200, 2004