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Development and characterization of a three-dimensional in vitro embryo implantation modelYe, Tianmin., 叶天民. January 2011 (has links)
published_or_final_version / Obstetrics and Gynaecology / Doctoral / Doctor of Philosophy
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A study of annexin A2 and implantationWang, Bing, 王冰 January 2014 (has links)
Implantation is a critical step in reproduction. It is complicated and well-coordinated consisting of apposition, attachment and invasion of embryo into the endometrium. The mechanism of implantation is unclear. Our previous proteomic study showed an increase of annexin A2 in the endometrium during the implantation window of mice, consistent with the increased annexin A2 expression in the receptive human endometrium. The hypothesis of this project was that annexin A2 mediatedthe embryo-endometrium attachment.
The first objective was to study the spatio-temporal expression of endometrial annexin A2 immunoreactivities in humans and mice. The cyclical change in annexin A2 expression in the mouse and human reproductive cycle suggested the involvement of a steroid regulatory mechanism. Interestingly, annexinA2 was transiently expressed on the membrane between the mouse uterine luminal epithelium and the implanting embryos from Day 4 (pre-implantation) to Day 5 (post-implantation) of pregnancy. No such signal change was observed at the inter-implantation sites, showing that the implanting embryos partially regulated annexin A2 expression. These observations and the high expression of the molecule in the luminal epithelium of human endometrium in the mid-and late luteal phase were consistent with a role of annexin A2 in implantation.
The second objective was to verify the action of steroids on annexin A2 expression. It was found that a combination of 6675 pmol/L of estrogen and 429.8nmol/L of progesterone increased the total and apical surface expression of annexin A2. In mice, estrogen but not progesterone, increased annexin A2 expression in the uterine luminal epithelium of ovariectomized mice.
The third objective was to study the function of annexin A2 in embryo-endometrium attachment using an Ishikawa (endometrial epithelial cells)-JEG-3 trophoblast spheroids (embryo surrogate) coculture model. Knockdown of the expression of annexin A2 in either or both cell lines significantly decreased the attachment rate of the spheroids onto the endometrial cells. The suppressive action on the two cell lines was additive. The attachment was also suppressed in the presence of anti-annexin A2 antibody during coculture. Annexin A2 was also involved in mouse implantation as demonstrated by a significant decrease in implantation sites after injection of anti-annexin A2 antibody into the mouse uterine horn.
The final objective was to study the action of annexin A2 as an adhesive molecule in embryo attachment. It was found that loss of P11, the binding partner of annexin A2, reduced the attachment rate of the JEG-3 spheroids probably by decreasing the translocation of annexin A2 to the surface of the endometrial cells. Recombinant P11 and annexin A2 protein failed to bind significantly to the Ishikawa cells and the JEG-3 cells.
In summary, this study demonstrates the involvement of annexin A2 as an adherent molecule in the embryo-endometrium interaction. / published_or_final_version / Obstetrics and Gynaecology / Doctoral / Doctor of Philosophy
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Role of ulipristal acetate in regulating endometrial gene expression and spheroids attachmentLi, Yingxing, 李莹星 January 2012 (has links)
The novel emergency contraceptive Ulipristal acetate (UPA) belongs to the progesterone receptor modulator family. A single oral dosage of 30mg UPA within 120 hours of unprotected intercourse could delay ovulation and differentiation of endometrium. Yet, whether UPA affect embryo implantation remains largely unknown. This study aims to investigate whether UPA affect endometrial gene expressions and embryo attachment onto endometrial epithelial cells.
The PR-expressing human endometrial carcinoma cell line Ishikawa was used and treated with 10nM estrogen, 1μM progesterone or 4μM UPA for 24 hours. Changes in transcriptome profiles were analyzed by Affymetrix Human Gene 1.0 ST array GeneChip. Gene clustering showed the gene expression pattern after UPA treatment was similar to control (0.1% ethanol); while estrogen treated group was different from all the other groups. Totally, 8 genes were significantly increased and 1 was decreased (≥2-fold, p<0.05) after UPA treatment. All except one of the 8 up-regulated genes were also up-regulated by estrogen; while only one of them increased after progesterone treatment. Most genes that were altered by UPA were involved in angiogenesis and vascular remodeling.
The effect of UPA on human embryo-endometrium attachment was carried out using an in vitro multi-cellular spheroids-endometrial epithelial cell co-culture model. Human choriocarcinoma cell line JAR and Ishikawa were used. UPA (0.04-4μM) treatment for up to 48 hours did not affect the proliferation of JAR or Ishikawa cells. Similarly, the attachment of JAR spheroids onto Ishikawa cells after 1 hour co-culture was not affected by UPA treatment. The molecules of Wnt/β-catenin signaling pathway, a pathway that is actively involved in embryo implantation, such as the β-catenin and GSK-3β, and endometrial receptive marker E-cadherin were not changed after UPA treatment. In Ishikawa cells, the expression of PR-A was induced after UPA (0.04-4μM) treatment; while PR-B increased when 0.04 or 4μM UPA used. However, the PR-A/PR-B ratio remained unchanged after all concentration of UPA treatment.
The effect of UPA on spheroids attachment was further investigated with cultured human primary endometrial epithelial cells. Endometrial glandular epithelial cells were digested and isolated from endometrial biopsy taken from IVF patients on day 7 after luteinizing hormone surge (LH+7). A co-culture assay was optimized with JAR spheroids and endometrial epithelial cells that were growing on Matrigel. The attachment rate of JAR spheroids is approximately 60% after 3 hours incubation. However, after 24 hours of exposure to 4μM UPA, the attachment remained comparable to that of the control group.
In conclusion, UPA could alter the expression of genes in Ishikawa cells mainly related to angiogenesis. It is likely that UPA may affect stromal decidualization and blastocyst invasion after attachment. However, UPA did not affect the expression of Wnt-signaling molecules and attachment of JAR spheroids onto either Ishikawa or human primary endometrial epithelial cell. / published_or_final_version / Obstetrics and Gynaecology / Master / Master of Philosophy
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The mechanisms controlling embryonic axon growth and guidanceBrown, Samantha January 2018 (has links)
My thesis investigated the mechanisms important for the development of the mammalian optic pathway and whether Primodos, a hormonal pregnancy test drug used between 1958 and 1978, has the potential to cause birth defects. I found that DSCAM (Down's syndrome cell adhesion molecule) is required for the fasciculation and growth of RGC axons. In mice carrying spontaneous mutations in DSCAM (Dscamdel17) normal axon pathfinding occurs. However, growth of axons from the optic chiasm towards their targets is impaired and axon organisation in the optic chiasm and tracts, and RGC growth cone morphologies, are also altered. Conversely, DSCAM gain-of-function resulted in exuberant growth into the dorsal thalamus. In vitro, DSCAM promotes RGC axon growth and fasciculation independently of cell contact. Along with previous work in the lab, my findings identified DSCAM as a permissive signal that promotes the growth and fasciculation of RGC axons. Spondins and their LRP binding partners are expressed in both the retina and around the developing optic pathway, consistent with a role in regulating growth of RGC axons towards visual targets. In vitro retinal explant cultures exposed to cells transfected with F-spondin, or its TSR domains, did not however provide evidence of axon growth modulation via F-spondin. I used Zebrafish embryos, a human cell-line and mouse retinal explants to investigate the actions of the components of Primodos upon embryonic axon growth, intersomitic vessel development and changes to cell number, proliferation and cell death. NA/EE-mixture exposure caused rapid morphological damage in Zebrafish embryos, affecting multiple organ systems and affecting physical movement. The NA/EE-mixture also affects nerve outgrowth and blood vessel patterning directly and accumulates in the III developing embryo for at least 24 hours. These data demonstrate that Norethisterone acetate and Ethinyl estradiol are potentially teratogenic, depending on dose applied and embryonic stage of development.
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Human embryo in vitro : a processual entity in legal stasisMcMillan, Catriona Alice Wilson January 2018 (has links)
This doctoral research explores the ways in which UK law engages with embryonic processes, namely under the Human Fertilisation and Embryology Act 1990 (as amended). The research offers a fuller understanding of these elusive and evolving biological processes, and in particular, how they can, in turn, allow us to understand legal process and legal regulation more deeply. To do so, the thesis employs an anthropological concept - liminality - coined by Arnold van Gennep, which is itself concerned with revealing the dynamics of process. Liminality may be described as being concerned with the spaces in between distinct stages of human experience or with the process of transition between such stages. With this framing of liminality in mind - which is often characterised as a three-stage process of human experience - the research is divided into three parts, broadly reflecting the three parts of van Gennep's liminal schema: into, through, and out of liminality. It is argued herein that in regulating the embryo - that is, a processual liminal entity in itself - the law is regulating for uncertainty. Tracing the legal governance of the early stages of human life, from its inception to today's regulatory frameworks, the research diagnoses a 'legal gap' between the conceptual basis for regulation, and practical 'realities' of the 1990 Act (as amended). In particular, this 'gap' is typified by uncertainty surrounding embryos in vitro, and what this thesis diagnoses as 'legal stasis'. In order to situate this novel liminal analysis within existing paradigms, however, the thesis first frames embryos in vitro as 'gothic', building upon emergent analytical responses to postmodern forms of categorisation. This framing helps to articulate the nature of, and the reasons for, the above-mentioned 'legal gap'. This framing is nonetheless incomplete without a liminal lens, as it draws our attention to the dynamics of the processes occurring within this 'gap'. It is argued that considering the 'problem' in this manner enables us to move beyond conceptualisation, towards realisation. The gothic, and the liminal are thus used to critically assess legal representations of the embryo, and suggests that there are ways in which the law might better embrace the multiplicity of environments through which the embryo in vitro can travel, that is, either towards reproductive or research ends. It is argued that full recognition of these variable, relational liminal states of the embryo is important for the future of artificial reproduction and embryo research, and that this does not currently happen. In order for the law to reflect better the uncertain nature of embryonic processes, and the technologies that create them, the thesis posits a nuanced, contextual reframing of the embryo that captures the multiplicity of embryonic 'pathways' available within the 1990 Act (as amended). The overarching objective of this work is to consider a more coherent and robust intellectual defence of the ways in which we justify different treatments of in vitro embryos. It thus proposes a 'context-based approach' that embraces the variable, relational pathways already facilitated by the 1990 Act (as amended) in order to lead the embryo (and itself) into, through and out of liminality.
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Maternal-embryo interactions at the time of implantation in early pregnancy / by Tina Christine Lavranos.Lavranos, Tina C. January 1993 (has links)
1 v. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Obstetrics and Gynaecology, 1993
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Trisomy 8 mosaicism cell cycle kinetics and distribution trisomy 8 and normal cells in embryonic and extra-embryonic tissues /Pettit, Bonnie J. January 2001 (has links)
Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains vi, 41 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 39-41).
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Role of embryo quality in a randomised comparison of laser assisted hatching on the implantation rate of frozen thawed embryo transfercyclesNaveed, Fatima. January 2004 (has links)
published_or_final_version / Medical Sciences / Master / Master of Medical Sciences
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Maternal-embryo interactions at the time of implantation in early pregnancy /Lavranos, Tina Christine. January 1993 (has links) (PDF)
Thesis (Ph.D.) -- University of Adelaide, Department of Obstetrics and Gynaecology, 1993.
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Heparanase expression and function during embryo implantation and modulation of heparanase activity by HIP/RPL29 /D'Souza, Sonia S. January 2008 (has links)
Thesis (Ph.D.)--University of Delaware, 2008. / Principal faculty advisor: Daniel D. Carson, Dept. of Biological Sciences. Includes bibliographical references.
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