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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Contributions of emotion-focused and problem-focused coping, marital adjustment, and social support on Taiwanese women's distress while undergoing assisted reproductive technologies

Wang, Yaohua 16 June 2011 (has links)
Not available / text
82

Response of Day 8 Equine Embryos to Saccharide Solutions at Various Temperatures

Foster, Brittany 02 January 2013 (has links)
The response of Day Eight equine embryos to saccharide solutions was investigated as a first step in their potential use as non-permeating cryoprotective agents. Embryos were exposured to seven increasing concentrations of either sucrose or galactose at a temperature of 22°, 30° or 37°C. Each embryo was then rehydrated by exposing it to the same solutions in reverse. Embryos underwent osmotic dehydration, independent of treatment group, but embryo size had a significant effect on the response pattern. Embryos < 500µm dehydrated osmotically to 20% of their original volume. Those > 500µm exhibited a delayed response and only dehydrated to 40% of their original volume. When placed into decreasing concentrations, embryos partially rehydrated. Pre- and post-treatment embryo quality was compared and embryos were stained to determine the amount of apoptosis, with no difference in embryo survival between treatments. Results indicate that saccharides show promise for use in equine embryos < 500µm. / Ontario Veterinary College, Equine Guelph, Partnar Animal Health
83

A feminist interpretation of the implications and consequences of new reproductive technologies /

Misri, Anita P. January 1996 (has links)
The development of pre-conception and post-conception reproductive technologies has substantial implications and consequences for women. To better establish the impact of the eugenic and sexist traditions which support the elimination of disability/defect and the propagation of "designer babies," a survey of literature outlining the scientific, feminist, legal, cultural, and social perspectives regarding new reproductive technologies was undertaken. Three conclusions of this review are that while new reproductive technologies are not responsible for the environment which fosters bias and intolerance towards oppressed members of society, they have created eugenic demands by supporting genetic perfection; they have informally displaced women's rights to bodily autonomy in favour of the fetus' or potential future person's rights by supporting fetal personhood; and they have perpetuated sexism within the Indian community in Canada by supporting patriarchal institutions.
84

ATTITUDES TOWARD ASSISTED REPRODUCTIVE TECHNOLOGY: THE EFFECTS OF GENDER, RELATIONSHIP STATUS, AGE, AND SEXUAL ORIENTATION

Dooley, Brigitte A 01 January 2014 (has links)
Reproductive technology has extended procreative options to infertile, subfertile, unpartnered, and same-sex-partnered individuals, but this technology is sometimes used in circumstances that may be deemed unreasonable or inappropriate by some people. The purpose of this study was to assess the effects of five contextual variables—gender, relationship status, age, and sexual orientation of the individual or couple seeking reproductive assistance, as well as the source of gametes—on attitudes toward the procurement of reproductive services. A multiple-segment factorial vignette was administered to a sample of 257 reproductive-aged respondents. Results indicate that ART is generally viewed as an acceptable procedure by reproductive aged individuals, particularly in normative contexts with regard to age and marital status, but differences between single men and single women using ART services were surprising and the effects of sexual orientation were both complex and unexpected. As reproductive norms and medical advances change over time, ethical questions will continue to arise and be discussed by professionals and lay commentators alike. The findings reported here can inform those discussions, while also generating new research to make sense out of the surprising results.
85

Birds & bees : how nature and kinship are mobilized to support nuclear family narratives on fertility clinic websites. / Birds and bees : how nature and kinship are mobilized to support nuclear family narratives on fertility clinic websites.

Pender, Lisa Jane 12 November 2008 (has links)
This thesis explores how fertility clinics engage in various textual and visual strategies to locate nature and kinship in the context of the assisted conception technologies they offer. In particular, competing paradigms of modern technology solving problems of the body versus the “naturalness” of having a baby means that fertility clinics must mobilize particular understandings of nature and technology to bridge this gap. Additionally, fertility clinics draw upon culturally meaningful themes such as “birds and bees” to structure relationships among assisted conception technology participants. I argue that fertility clinic websites are public sites of discourse through which clinics both attempt to attract potential clients and shape understanding of assisted conception technology by offering particular explanations as real and natural.
86

Functional characterisation of the cumulus oocyte matrix during maturation of oocytes.

Dunning, Kylie Renee January 2008 (has links)
Female gametes, or oocytes grow and mature in a niche environment maintained by the somatic cells of the ovarian follicle. At ovulation ovarian follicle cells respond to the luteinising hormone (LH) surge coordinating the final maturation, meiotic resumption and release of oocytes. Simultaneously, production of a unique “mucified” extracellular matrix surrounding the oocyte through synthesis of Hyaluronan (HA) and HA cross-linking proteins produces an “expanded” and stabilised cumulus oocyte matrix with a specific composition, structure and function. In vitro maturation (IVM) of oocytes is a procedure by which cumulus oocyte complexes (COCs) are stimulated to produce cumulus matrix and undergo oocyte maturation ex vivo. In vitro maturation is a useful procedure for studying oocyte competence as well as offering health benefits for patients undergoing assisted reproduction. Oocytes derived from IVM have much lower developmental competence than in vivo matured oocytes, likely as a result of altered environmental conditions and gene expression leading to suboptimal maturation and/or inappropriate metabolic control in oocytes. Cumulus matrix expansion is widely used as an indicator of good oocyte developmental potential, however, the mechanism(s) that endow oocyte quality and how these may be influenced by the cumulus matrix are poorly understood. To better understand the process by which cumulus matrix is linked to the final stages of oocyte maturation, I undertook investigation of mouse COC matrix composition and function after in vivo maturation in comparison to IVM. The gene responsible for Hyaluronan synthesis, Has2, was not impaired under IVM conditions. In contrast, two key extracellular matrix proteins; Versican and Adamts1, which are normally selectively incorporated into periovulatory COCs in vivo, were greater than 10-fold reduced in IVM whether stimulated with Egf and/or FSH. This work is the first to show that commonly used IVM conditions result in altered gene expression in cumulus cells. Furthermore, the absence of Adamts1 and Versican suggest that COC matrix may be functionally insufficient. Although associated with good developmental potential, the function of the COC matrix in oocyte maturation is unknown. I assessed the properties of COC matrix that control metabolite supply to oocytes by examining transport of fluorescently labelled glucose and cholesterol across mouse COCs. Profound differences in the control of metabolite supply to oocytes in IVM were observed. In vivo matured complexes were capable of excluding glucose from the entire COC and cholesterol was excluded from oocytes. Conversely IVM COCs were more permissive to rapid equilibration of glucose and cholesterol concentrations across the complex and in oocytes. In fact both metabolites accumulated rapidly in IVM oocytes resulting in inverse gradient patterns of glucose and cholesterol abundance with highest concentrations accumulating in the oocyte after IVM vs highest concentrations surrounding the COC after in vivo maturation conditions. As oocytes are highly sensitive to high glucose my results indicate that metabolic balance in IVM may be disrupted due to impaired molecular filtration properties of the mucified COC matrix that controls supply of hydrophilic and lipophylic substrates. Importantly these novel findings can explain the glucose sensitivity of IVM oocytes and identifies a mechanism by which IVM may lead to poorer oocyte developmental competence. To translate these findings into the improvement of IVM I generated recombinant expression plasmid constructs for several Adamts1 and Versican functional domains. The efficacy of Versican as an IVM supplement that activates cumulus cell signal transduction was proved in principle, by showing enhanced COC matrix expansion when added to mouse IVM cultures. Similar mechanisms are likely to be functional in human COCs since I demonstrated VERSICAN and ADAMTS1 expression in human in vivo matured cumulus and granulosa cells. This work has advanced our understanding of oocyte maturation and will lead to improvements in IVM and healthier outcomes from reproductive therapies. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1342419 / Thesis (Ph.D.) -- University of Adelaide, School of Paediatrics and Reproductive Health, 2008
87

The ethics of preimplantation genetic diagnosis

Thakur, Sanjay, n/a January 2006 (has links)
Preimplantation genetic diagnosis is a technique used in the field of assisted reproduction. The technique is applied to embryos that have been created in vitro, in order to facilitate the selection of embryos according to particular genetic parameters. The use of preimplantation genetic diagnosis by prospective parents at high risk for having a child affected by a genetic disorder has facilitated the birth of unaffected children. Preimplantation genetic diagnosis has already been used for other purposes, such as screening for gender, and could in principle be used to screen for a wide range of genetic traits. The aim of this thesis is to provide good answers to the ethical questions provoked by the advent and continuing development of preimplantation genetic diagnosis. The thesis is divided into four parts. Part One provides a brief overview of the science of genetic selection. Part Two is centred on a discussion of two ethical principles. The principle of procreative liberty is based upon the idea that acts of interference in the reproductive lives of others should be avoided unless there is good justification for such acts. The principle of procreative beneficence is based upon the idea that prospective parents should select the child, of the possible children they could have, who is expected to have the best life. I will argue that the principle of procreative liberty should be applied to acts of interference in individuals� freedom to use preimplantation genetic diagnosis, while the principle of procreative beneficence should be applied to acts of selecting children. In Part Three, I will endorse a position that accords embryos a relatively low moral status, reject the arguments of the disability rights critique, argue that the eugenic aspects of preimplantation genetic diagnosis do not warrant much concern, and develop a framework for critically evaluating slippery slope arguments. Finally, in Part Four, specific applications of preimplantation genetic diagnosis will be examined in detail. Although each application raises unique ethical questions, this thesis aims to demonstrate that the consistent application of the principles and preliminary conclusions developed in Parts Two and Three provides the best means for determining how PGD should be used and which uses should be restricted.
88

Functional characterisation of the cumulus oocyte matrix during maturation of oocytes.

Dunning, Kylie Renee January 2008 (has links)
Female gametes, or oocytes grow and mature in a niche environment maintained by the somatic cells of the ovarian follicle. At ovulation ovarian follicle cells respond to the luteinising hormone (LH) surge coordinating the final maturation, meiotic resumption and release of oocytes. Simultaneously, production of a unique “mucified” extracellular matrix surrounding the oocyte through synthesis of Hyaluronan (HA) and HA cross-linking proteins produces an “expanded” and stabilised cumulus oocyte matrix with a specific composition, structure and function. In vitro maturation (IVM) of oocytes is a procedure by which cumulus oocyte complexes (COCs) are stimulated to produce cumulus matrix and undergo oocyte maturation ex vivo. In vitro maturation is a useful procedure for studying oocyte competence as well as offering health benefits for patients undergoing assisted reproduction. Oocytes derived from IVM have much lower developmental competence than in vivo matured oocytes, likely as a result of altered environmental conditions and gene expression leading to suboptimal maturation and/or inappropriate metabolic control in oocytes. Cumulus matrix expansion is widely used as an indicator of good oocyte developmental potential, however, the mechanism(s) that endow oocyte quality and how these may be influenced by the cumulus matrix are poorly understood. To better understand the process by which cumulus matrix is linked to the final stages of oocyte maturation, I undertook investigation of mouse COC matrix composition and function after in vivo maturation in comparison to IVM. The gene responsible for Hyaluronan synthesis, Has2, was not impaired under IVM conditions. In contrast, two key extracellular matrix proteins; Versican and Adamts1, which are normally selectively incorporated into periovulatory COCs in vivo, were greater than 10-fold reduced in IVM whether stimulated with Egf and/or FSH. This work is the first to show that commonly used IVM conditions result in altered gene expression in cumulus cells. Furthermore, the absence of Adamts1 and Versican suggest that COC matrix may be functionally insufficient. Although associated with good developmental potential, the function of the COC matrix in oocyte maturation is unknown. I assessed the properties of COC matrix that control metabolite supply to oocytes by examining transport of fluorescently labelled glucose and cholesterol across mouse COCs. Profound differences in the control of metabolite supply to oocytes in IVM were observed. In vivo matured complexes were capable of excluding glucose from the entire COC and cholesterol was excluded from oocytes. Conversely IVM COCs were more permissive to rapid equilibration of glucose and cholesterol concentrations across the complex and in oocytes. In fact both metabolites accumulated rapidly in IVM oocytes resulting in inverse gradient patterns of glucose and cholesterol abundance with highest concentrations accumulating in the oocyte after IVM vs highest concentrations surrounding the COC after in vivo maturation conditions. As oocytes are highly sensitive to high glucose my results indicate that metabolic balance in IVM may be disrupted due to impaired molecular filtration properties of the mucified COC matrix that controls supply of hydrophilic and lipophylic substrates. Importantly these novel findings can explain the glucose sensitivity of IVM oocytes and identifies a mechanism by which IVM may lead to poorer oocyte developmental competence. To translate these findings into the improvement of IVM I generated recombinant expression plasmid constructs for several Adamts1 and Versican functional domains. The efficacy of Versican as an IVM supplement that activates cumulus cell signal transduction was proved in principle, by showing enhanced COC matrix expansion when added to mouse IVM cultures. Similar mechanisms are likely to be functional in human COCs since I demonstrated VERSICAN and ADAMTS1 expression in human in vivo matured cumulus and granulosa cells. This work has advanced our understanding of oocyte maturation and will lead to improvements in IVM and healthier outcomes from reproductive therapies. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1342419 / Thesis (Ph.D.) -- University of Adelaide, School of Paediatrics and Reproductive Health, 2008
89

Biopsychosocial associates of infertility related distress and treatment outcomes.

Mahajan, Neha Naresh January 2008 (has links)
The experience of difficulties in conception, the diagnosis of infertility and its treatment are frequently associated with anxiety and overall distress. However, current understanding regarding the determinants of variability in the levels of distress among women undergoing infertility treatment is limited; and the evidence of the significance of distress as a risk factor for assisted conception following IVF/ICSI is inconsistent. The thesis addressed both these issues. Overall the thesis is informed by the biopsychosocial model of health and illness. Four studies were conducted. The data was collected in three IVF clinics in India. A consecutive sample of 85 infertile women about to commence IVF/ICSI cycle was recruited in the project at cycle baseline and followed through one treatment cycle. The first two studies examined this sample of women at baseline to identify the biopsychosocial factors associated with infertility related distress. The first study examined the degree of cognitive–behavioural adjustment to infertility, its treatment and treatment related eventualities, while the second study focused on the factors associated with affective aspects of infertility related distress such as increase in negativity and decrease in positivity. The third study examined the pattern of change in stress operationalized in terms of changes in Affect and State Anxiety in a sample of 74 infertile women during an IVF/ICSI cycle. The final study developed a prognostic model for evaluating the unique contribution of baseline distress as well as treatment related stress in estimating the odds of pregnancy following IVF based on a consecutive sample of 73 women. Collectively, the first two studies indicate that at the outset of the IVF/ICSI cycle, some women are more prone to distress than others, and that this variability is associated with their intrapersonal, interpersonal and sociodemographic attributes. These two studies have identified a set of protective and vulnerability factors related to cognitive-behavioural and affective aspects of distress. The last two studies clearly indicate that the level of distress tends to rise during the treatment among the majority of infertile women. The rising trend continued to be significant even after controlling for variables known to somewhat influence infertility related distress such as age, education, occupation, employment, financial burden and etiological factors. Further, a prognostic model is developed that proposes that both baseline level of stress and treatment stress make a unique contribution in defining the odds of pregnancy outcome for the patients. In short the thesis clearly brings out the case for integrating psychosocial care with the routine medical interventions for infertility. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1325419 / Thesis (Ph.D.) - University of Adelaide, School of Psychology, 2008
90

Examination of the Role of p53 in Embryo and Sperm Function

Gunay, Nida January 2007 (has links)
Master of Science in Medicine (by research) / Assisted reproductive technologies (ARTs) are very efficient in producing embryos, however many of these embryos have poor viability. No more than 50% of IVF embryos complete preimplantation development (Hardy et al. 2001). The poor viability is manifested as a reduced rate of cell proliferation and increased rates of apoptosis in the early embryo, resulting in high rates of embryo mortality (Hardy et al. 2001). The reduced viability occurs as a response to a range of cellular stressors that are a consequence of embryo culture (Hardy et al. 2001). The stress of culture disrupts some survival signalling pathways, metabolism of substrates and induces redox stress (Hardy et al. 2001). The cellular stress sensor p53 is expressed in the early embryo but is normally kept at very low levels (Li et al. 2005). This latency may be breached in IVF embryos following culture of zygotes in vitro for 96 hours, resulting in the up-regulation and nuclear accumulation of p53 (Li et al. 2005). Activation of the p53 stress-sensing pathway in the early mouse embryo by culture in vitro causes a marked loss of their developmental competence (Li et al. 2005). This study aimed to establish whether benefits could be obtained by culturing mice IVF embryos in the presence of p53 protein inhibitors. IVF zygotes were cultured individually in 10µl drops of 1.25, 2.5, 5 or 10µM Pifithrin-a (PFTa) in 0.05% DMSO for 96 hours. On day 5 the development stage was assessed. Embryos reaching the blastocyst stage were fixed and stained with Hoechst 33342 for total cell count and the proportion of nuclei with normal and abnormal morphology. There was an increase in the blastocyst rate, total cell count and the proportion of nuclei in a blastocyst with normal nuclei in 10µM-treated embryos. This study also aimed to determine whether benefits could be obtained by incubating mouse IVF sperm with p53 protein inhibitors during IVF. IVF sperm was treated with 1.25, 2.5, 5 or 10µM of PFTa in 0.05% DMSO during incubation with oocytes for 6 hours. Resulting zygotes were cultured for 96 hours individually in 10µl drops of MODHTFM. On day 5 the development stage was assessed. Embryos reaching the blastocyst stage were fixed and stained with Hoechst 33342 for total cell count and the proportion of nuclei with normal and abnormal morphology. There was a reduction in the proportion of fragmented nuclei in blastocysts derived from 1.25 and 10µM-treated sperm. 10µM treated sperm increased the total cell count, the proportion of normal nuclei in a blastocyst and the blastocyst development rate. IVF sperm incubated with 1.25µM PFTa during insemination of oocytes increased the fertilisation rate. Another aim of this study was to establish whether p53 siRNA could inhibit p53 mRNA in mice IVF embryos and if so, whether this would improve embryo viability in culture. IVF zygotes were transfected with 15nM p53 small inhibiting RNA (siRNA) and 0.8% Oligofectamine Reagent immediately, 24 h, 48 h and 72 h after IVF then cultured individually in 10µl drops of MOD-HTFM for a total of 96 hours. On day 5 the blastocyst rate was assessed and immunofluorescence performed probing for p53. There was no significant reduction in p53 expression and no improvement in blastocyst rate at any of the transfection times. However, there was a decrease in the proportion of nuclei which expressed p53 when p53 siRNA was transfected 72 hours after IVF. Also, it was determined that siRNA was efficiently being delivered into the preimplantation embryo with Oligofectamine Reagent. Lastly, this study aimed to determine whether mice sperm with p53 gene deletions have a selective advantage in fertilising the oocyte compared to their wild-type counterparts. p53+/- males were mated with p53+/+ females and the resulting zygotes genotyped after 24 hours of culture. More than 50% of offspring had a p53+/+ genotype. There was no selective advantage for p53 null sperm to fertilise the oocyte, there was actually a disadvantage. The selective disadvantage for p53 null sperm to fertilise the F1 hybrid oocyte in IVF compared to its wild-type counterparts may imply that p53 null sperm are not as viable and may have a survival disadvantage. The reduction in fertility of p53 null sperm in vitro infers that p53 function may be important for the fertility of the mouse sperm in vitro. The results of this thesis could establish means of improving human embryo viability in ART, some examples being P53 protein inhibition in preimplantation embryos during culture prior to transfer to the uterus, or P53 protein inhibition in IVF sperm. The use of the new technology, p53 siRNA was not effective in inhibiting p53 expression, although the build-up experiments determined that siRNA is efficiently delivered into the preimplantation embryo with Oligofectamine Reagent. The demonstration that p53 null sperm has a selective disadvantage in fertilising the oocyte compared to their wild-type counterparts does not indicate a positive selection pressure for naturally occurring mutations to this gene. And so, there is no concern regarding the genetic and epigenetic risks to progeny arising from assisted reproductive technologies with respect to sperm.

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