932 resultados para Assisted reproductive technologies (ART)
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Infertility is directly related to chromosomal abnormalities in germ cells. Among them, the aneuploidies are the most frequent chromosomal abnormalities and responsible for embryo implantation failures, miscarriages, fetal losses and newborns with congenital malformations, mental disability and neuropsychomotor developmental delay. Male patients with normal somatic karyotype may present different rates of aneuploidies in sperm, resulting in abnormal embryos. This study aimed to correlate the frequency of chromosomal aneuploidies in spermatozoa with embryo implantation rate in couples undergoing assisted reproductive techniques. The methodology has included chromosomal analysis by GTG banding and molecular cytogenetic study using Fluorescent In Situ Hybridization technique for evaluation of chromosomes 9, X and Y in germ cells of 22 patients referred to the Human Reproduction Service of the Clinical Hospital FMRP-USP. Embryo implantation rates were determined by hormonal evaluation in maternal peripheral blood and ultrasound confirmation. Two patients presented abnormal karyotype, characterized by polymorphism of the heterochromatic region of the long arm of chromosome 9 and a satellite in the short arm of chromosome 22. Both alterations, usually considered variants of normality, have been related to infertility phenotype and miscarriages. Significant differences were detected between couples who presented pregnancy (group 1) and couples with embryo implantation failure (group 2), with higher frequency of aneusomy and diploidy of chromosome 9, as well as total aneuploidy in sperm of group 2 patients. Our results suggest a correlation between aneuploidy and embryo implantation rates, since the infertile group with reproductive failure has showed higher frequency of aneuploidy. Screening for aneuploidies detection in male germ cells should be included in order to decrease embryo implantation failures, miscarriages and fetuses with chromosomal ...
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The aim of this paper is to analyze the contents of the feminist discourses on the body, as regards the continuities and changes in the social practices related to reproduction. It covers the period going from the 70’s to nowadays, when the growing improvement of medical science and technology has started interfering with the body and reproductive practices. We seek to understand how the inaugural discourses on the contemporary feminism related to the body have developed during this period, with the increasing use of reproductive technologies in France and Brazil. The feminist concept of self-control of the body has turned into the analysis of the fusion of body and technologies that build new identities
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Several recent studies have examined the connection between religion and medical service utilization. This relationship is complicated because religiosity may be associated with beliefs that either promote or hinder medical helpseeking. The current study uses structural equation modeling to examine the relationship between religion and fertility-related helpseeking using a probability sample of 2183 infertile women in the United States. We found that, although religiosity is not directly associated with helpseeking for infertility, it is indirectly associated through mediating variables that operate in opposing directions. More specifically, religiosity is associated with greater belief in the importance of motherhood, which in turn is associated with increased likelihood of helpseeking. Religiosity is also associated with greater ethical concerns about infertility treatment, which are associated with decreased likelihood of helpseeking. Additionally, the relationships are not linear throughout the helpseeking process. Thus, the influence of religiosity on infertility helpseeking is indirect and complex. These findings support the growing consensus that religiously-based behaviors and beliefs are associated with levels of health service utilization.
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BACKGROUND: It is known that endometriosis is an inflammatory disease and those patients seem to have lower pregnancy rates. The aim of the study was to investigate the concentrations of chemokines and proinflammatory cytokines in the follicular fluid of patients with and without endometriosis. METHODS: Follicular aspiration, recovering follicular fluid during assisted reproductive treatment, follicular fluid storage and analysis of chemokines and proinflammatory cytokines were carried out. Tumor necrosis factor-alpha, interleukin-1 beta, interleukin-6, interleukin-8, interleukin-15, leukemia inhibitory factor, epithelial neutrophil-activating peptide 78, regulated upon activation, normal T-cell expressed and secreted, and growth-regulated oncogene-alpha were analyzed in the follicular fluid and compared between women with (n =47) and without endometriosis (n = 279). RESULTS: The above cytokines were detected in the follicular fluid samples. Epithelial neutrophil-activating peptide 78 levels were significantly higher in follicular fluid from endometriosis patients than from controls (p = 0.008). Increases (to twice the control level) were also observed for tumor necrosis factor-alpha and for interleukin-6. CONCLUSIONS: Increased follicular fluid levels of epithelial neutrophil-activating peptide 78, tumor necrosis factor-alpha and interleukin-6 indicate that these cytokines may influence oocyte quality and fecundability of women with endometriosis by deteriorating the microenvironment in the human follicle.
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Especially young women with cancer face rising survival rates due to remarkable progress in oncologic therapies. Preserving fertility is a major concern for both patients and their next of kin. Well established reproductive technologies such as cryopreservation of fertilized oocytes after in vitro fertilization already make fertility preservation possible for some patients. This review is dedicated to the emerging techniques that are becoming widely accepted for fertility preservation in young women and girls with cancer, such as auto transplantation of ovarian tissue cryopreservation and in vitro maturation (IVM) of either oocytes or follicles. First results are encouraging. But some challenges still have to be tackled in order for these novel technologies to be routinely employed with the aim of successful fertility preservation.
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In several species, a family of nuclear receptors, the peroxisome proliferator-activated receptors (PPARs) composed of three isotypes, is expressed in somatic cells and germ cells of the ovary as well as the testis. Invalidation of these receptors in mice or stimulation of these receptors in vivo or in vitro showed that each receptor has physiological roles in the gamete maturation or the embryo development. In addition, synthetic PPAR gamma ligands are recently used to induce ovulation in women with polycystic ovary disease. These results reveal the positive actions of PPAR in reproduction. On the other hand, xenobiotics molecules (in herbicides, plasticizers, or components of personal care products), capable of activating PPAR, may disrupt normal PPAR functions in the ovary or the testis and have consequences on the quality of the gametes and the embryos. Despite the recent data obtained on the biological actions of PPARs in reproduction, relatively little is known about PPARs in gametes and embryos. This review summarizes the current knowledge on the expression and the function of PPARs as well as their partners, retinoid X receptors (RXRs), in germ cells and preimplantation embryos. The effects of natural and synthetic PPAR ligands will also be discussed from the perspectives of reproductive toxicology and assisted reproductive technology.
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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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Ce travail porte sur l’identification, la fonction et la régulation des molécules maternelles d’ARNm qui dirigent la compétence développementale juste après la fécondation chez les bovins. Tout d’abord, en utilisant le modèle du temps écoulé jusqu’au premier clivage zygotique et à travers l’évaluation du transcriptome des embryons à 2-cellules, il fut possible de déterminer la signature moléculaire des niveaux extrêmes de compétence au développement et sélectionner des molécules candidates pour des études postérieures. Les résultats ont montré que les embryons de capacité développementale variable diffèrent dans certaines fonctions comme la réparation de l’ADN, le traitement de l’ARN, la synthèse de protéines et l’expression génique définies par des ARNm synthétisés par l’ovocyte. Pour obtenir une confirmation fonctionnelle, une paire de transcrits maternels (l’un détecté dans notre sondage précédent et l’autre étant une molécule reliée) ont été inhibés par « knock-down » dans des ovocytes. Les effets du knock-down de ces facteurs de transcription sont apparus avant la formation des blastocystes dû à une diminution de la capacité au clivage et celle à progresser après le stage de 8-cellules. L’analyse moléculaire des embryons knock-down survivants suggère qu’un de ces facteurs de transcription est un contrôleur crucial de l’activation du génome embryonnaire, qui représente une fenêtre développementale dans l’embryogenèse précoce. Dans la dernièr étude, nous avons testé si les facteurs de transcription d’intérêt sont modulés au niveau traductionnel. Des ARNm rapporteurs couplés à la GFP (Protéine fluorescente) contenant soit la version courte ou la version longue de la séquence 3’-UTR des deux molécules furent injectées dans des zygotes pour évaluer leur dynamique traductionnelle. Les résultats ont montré que les éléments cis-régulateurs localisés dans les 3’-UTRs contrôlent leur synchronisation traductionnelle et suggèrent une association entre la compétence développementale et la capacité de synthèse de ces protéines. Ceci conduit à l’idée que ces facteurs de transcription cruciaux sont aussi contrôlés au niveau traductionnel chez les embryons précoces. Les connaissances acquises ont joué un rôle essentiel pour définir le contrôle potentiel des molécules maternelles sur les embryons au début de leur développement. Cette étude nous montre aussi une utilisation potentielle de cette information ainsi que les nouveaux défis présents dans le secteur des technologies reproductives.
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Background: The impact of cancer upon children, teenagers and young people can be profound. Research has been undertaken to explore the impacts upon children, teenagers and young people with cancer, but little is known about how researchers can ‘best’ engage with this group to explore their experiences. This review paper provides an overview of the utility of data collection methods employed when undertaking research with children, teenagers and young people. A systematic review of relevant databases was undertaken utilising the search terms ‘young people’, ‘young adult’, ‘adolescent’ and ‘data collection methods’. The full-text of the papers that were deemed eligible from the title and abstract were accessed and following discussion within the research team, thirty papers were included. Findings: Due to the heterogeneity in terms of the scope of the papers identified the following data collections methods were included in the results section. Three of the papers identified provided an overview of data collection methods utilised with this population and the remaining twenty seven papers covered the following data collection methods: Digital technologies; art based research; comparing the use of ‘paper and pencil’ research with web-based technologies, the use of games; the use of a specific communication tool; questionnaires and interviews; focus groups and telephone interviews/questionnaires. The strengths and limitations of the range of data collection methods included are discussed drawing upon such issues as of the appropriateness of particular methods for particular age groups, or the most appropriate method to employ when exploring a particularly sensitive topic area. Conclusions: There are a number of data collection methods utilised to undertaken research with children, teenagers and young adults. This review provides a summary of the current available evidence and an overview of the strengths and limitations of data collection methods employed.
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Tese de Doutoramento, Ciências Agrárias (Reprodução Animal), 26 de Junho de 2013, Universidade dos Açores.
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Due to economical and scientific limitations, sheep embryo reproductive technologies are less commercially applied than in other animal species. However, it is very clear that, in the near future, those techniques are expected to have a central role in animal production as a consequence of genetic and reproductive demands. One drawback is that results obtained after sheep embryo cryopreservation are unattractive for commercial purposes. It is expected that a successful cryopreservation of sheep embryos can push forward all other reproductive biotechnologies in this species, such as multiple ovulation and embryo transfer (MOET), artificial insemination, or in vitro production of embryos. This paper tries to discuss the current and future perspectives of cryopreservation of in vivo- and in vitro-produced sheep embryos concerning advantages and limitations for its practical use and possible solutions for improving methods to allow a higher survival rate of cryopreserved embryos.
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The use of reproductive and genetic technologies can increase the efficiency of selective breeding programs for aquaculture species. Four technologies are considered, namely: marker-assisted selection, DNA fingerprinting, in-vitro fertilization, and cryopreservation. Marker-assisted selection can result in greater genetic gain, particularly for traits difficult or expensive to measure, than conventional selection methods, but its application is currently limited by lack of high density linkage maps and by the high cost of genotyping. DNA fingerprinting is most useful for genetic tagging and parentage verification. Both in-vitro fertilization and cryopreservation techniques can increase the accuracy of selection while controlling accumulation of inbreeding in long-term selection programs. Currently, the cost associated with the utilization of reproductive and genetic techniques is possibly the most important factor limiting their use in genetic improvement programs for aquatic species.
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This article provides a critical analysis of the current Australian regulatory landscape at the interface between genetics and reproductive decision- making. The authors argue that a comparative analysis with other countries and international law and a contextual examination of the way law regulates concepts such as disease and health, abnormality and normality is necessary before we can develop appropriate policy and legislative responses in this area. Specific genetic testing technologies are considered including prenatal genetic testing, preimplantation genetic diagnosis and inheritable genetic modification. An increasing number of members of the Australian community are using genetic testing technologies when they decide to have a baby. The authors argue that as concepts of disease and health vary among members of the community and the potential to test for traits other than illness increases, a new tension arises between an ethic of individual choice and a role for government in regulating reproductive decision-making.