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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.
11

Reflections on the Law and Ethics of Regulating Preimplantation Genetic Diagnosis in the United Kingdom

Krahn, Timothy 14 November 2013 (has links)
The purpose of this thesis is to query the legitimacy of offering preimplantation genetic diagnostic (PGD) testing against Down's syndrome on the basis of United Kingdom (UK) law and policies. I will argue that extending PGD testing for Down’s syndrome as a permissible use of this technology does not (straightforwardly) adhere with the Human Fertilisation and Embryology Authority (HFEA) Code of Practice's stated factors which are to be considered when assessing the appropriateness of PGD applications. Indeed, due consideration of the evidence given in the relevant literature about the capacities and quality of life possible for persons living with Down's syndrome would seriously call into question the validity of a positive judgment recommending PGD as a treatment service for Down's syndrome according to the current UK regulatory instruments. I end the thesis by considering why the HFEA's relatively recent decision to limit client access according to an exclusive list of "serious" and therefore "in principle" test-worthy genetic conditions—understood as legitimate applications for PGD—stands to entrench prejudice, stigma, social bias, and unfair discrimination against the disadvantaged social group of persons living with Down's syndrome.
12

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.
13

Preimplantation diagnosis / Ke-hui Cui

Cui, Ke-hui January 1993 (has links)
Bibliography: leaves 126-147 / xiv, 147 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Summary: Aims to develop reliable procedures for determining the genetic status of embryos derived by IVF procedures prior to implantation. Prenatal diagnosis allows pregnancy to be established using only acceptable embryos / Thesis (Ph.D.)--University of Adelaide, Dept. of Obstetrics and Gynaecology, 1994
14

Morphological evaluation of blastocyst after vitrification depending on treatment modality

Tovar Perez, Alexander Tovar January 2018 (has links)
Assisted reproductive technology procedures has become a more complex treatment over the years after implementation of preimplantation genetic diagnostics and cryopreservation methods such as slow freeze and vitrification. When embryos undergo these methods they are exposed to external damage that threaten to affect their quality and thereby lead to lower survival rates and lower pregnancy rates. The aim of this study was to document blastocysts quality after vitrification, re-vitrification and preimplantation genetic diagnosis with subsequent vitrification. A total of 126 blastocysts were collected, of which 119 blastocysts were documented with the help of an experienced embryologists and the remaining seven blastocysts were from a new series of re-vitrified embryos. The 126 collected blastocyst were allocated into groups depending on their degree of preimplantation genetic diagnosis and vitrification. The gathered data was scoring according to morphology, expansion and proportion of necrotic cells at 2 and 4 hours of the expansion phase. Fisher exact test was used for statistical evaluation. There were no significant difference when comparing data before and after vitrification and preimplantation diagnosis, which indicates that these methods do not cause morphological damage to the blastocyst.
15

Genetic contributory factors to infertility

Raberi, Araz January 2017 (has links)
Introduction: In recent years, the average age of first reproduction has risen significantly, the mean now standing at around 30 years in many countries. The adverse effects of maternal age on fertility and reproduction have been well documented. However, the influence of paternal age on fertility, reproduction and postnatal health is relatively poorly understood, and 50% of all male infertility cases are classed as idiopathic or unexplained infertility. Methods: The aim of this study was to investigate factors that contribute to male infertility, split into two main parts. The first part focused on analysing data collected from patients who had undergone fertility treatment to assess the influence of different factors on infertility, especially at the genome level. The second part attempted to deal with some of the technical challenges of screening and diagnostic methods to study the genome, with the aim of providing tools that would assist future studies in pinpointing genetic factors responsible for infertility, especially in cases of idiopathic infertility. Results: Based on data from the first part of the study, it was determined that advanced paternal age can affect sperm progressive motility, sperm DNA integrity and the fertilisation rate of in vitro fertilisation (IVF) cycles, as well as the development of embryos. Direct analysis of sperm DNA fragmentation (SDF) and degradation levels revealed an association between elevated SDF and impaired embryo development. Furthermore, a correlation was shown between chromosome aneuploidy and variance in SDF and sperm DNA degradation. Moreover, aneuploidy can influence abnormal sperm morphology and consequently also progressive motility. Also, embryo development rate of IVF cycles on day three, demonstrated a significant decline in cycles where the sperm used for fertilisation had a high aneuploidy rate, which can highlight the reduced developmental capacity of aneuploid embryos. From the lifestyle factors assessed, only alcohol consumption significantly correlated with the sperm DNA damage. Therefore, poor semen quality may highlight damage that has been incurred by the sperm DNA. When the semen quality is suboptimal, the intracytoplasmic sperm injection (ICSI) technique is suggested as a standard strategy to improve the prognosis of ART. However, when the progressive motility is poor, the ICSI approach is not as effective. Based on our findings and in line with other studies, the only sperm parameter that can be affected by paternal age is sperm motility, which could be an indicator of SDF. Therefore, the decline in ICSI fertilisation rate in patients with impaired sperm progressive motility could be due to sperm DNA damage, and even ICSI cannot improve the fertilisation rate considerably. Discussion: The aim of the second part of this project was to establish a robust workflow for whole- genome amplification (WGA) and whole-genome sequencing of single cells to improve the coverage rate and fidelity, with the aim of providing means of detecting any mutation in the genome that might be responsible for reduced embryonic developmental competence. Towards this end, the efficiencies of two different WGA protocols (REPLI-g and TruePrime) were compared. Multiple technical factors required optimisation in order to create a suitable protocol. Our results demonstrated the overall superiority of REPLI-g compared to TruePrime in almost all the assessed parameters. The amplification rate of REPLI-g was much faster than that of TruePrime, and prolonged incubation led to overamplification and an increased duplication rate. However, the TruePrime method has a slower amplification rate and therefore, by increasing the incubation time, it was possible to improve the quality of the data. The modified protocol with reduced volume also had the most promising outcome in terms of the data produced, and could fulfil our expectations by being fast, cost-effective and efficient. Conclusion: In conclusion, the results from the first part of this study confirmed the negative impact of male age on assisted reproductive treatments, which can result in decreased success rates of fertilisation. Other factors such as sperm DNA damage may also contribute to this age effect, suggesting that assessing this parameter prior to fertility treatment, and attempting to mitigate elevated levels of sperm DNA damage, may be of value to older patients. Additionally, overcoming the technical challenges in studying genetic contributory factors in infertility is a promising step toward better understanding of the mutations and variations that are involved in this phenomenon.
16

Identificação do sexo de embriões humanos através da análise de blastômero pelas técnicas da reação em cadeia da polimerase em tempo real (PCR em tempo real) e hibridização in situ fluorescente (FISH)

Martinhago, Ciro Dresch [UNESP] 02 February 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-02-02Bitstream added on 2014-06-13T20:48:03Z : No. of bitstreams: 1 martinhago_cd_dr_botfm_prot.pdf: 1810275 bytes, checksum: 5592d92db2f6fd8dea862970f2f6df15 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Cpdp - Centro Paulista de Pesquisa e Diagnostico / O diagnóstico genético pré-implantacional (PGD) é um procedimento o qual permite que embriões sejam testados perante uma doença genética antes de sua transferência para o útero materno, ou seja, antes... / Preimplantation genetic diagnosis (PGD) is a procedure that permits embryos to be tested for a possible genetic diseade before being transferred to the maternal uterus, i.e., before the beginning of pregnancy... (Complete abstract click electronic access below)
17

Reflections on the Law and Ethics of Regulating Preimplantation Genetic Diagnosis in the United Kingdom

Krahn, Timothy January 2013 (has links)
The purpose of this thesis is to query the legitimacy of offering preimplantation genetic diagnostic (PGD) testing against Down's syndrome on the basis of United Kingdom (UK) law and policies. I will argue that extending PGD testing for Down’s syndrome as a permissible use of this technology does not (straightforwardly) adhere with the Human Fertilisation and Embryology Authority (HFEA) Code of Practice's stated factors which are to be considered when assessing the appropriateness of PGD applications. Indeed, due consideration of the evidence given in the relevant literature about the capacities and quality of life possible for persons living with Down's syndrome would seriously call into question the validity of a positive judgment recommending PGD as a treatment service for Down's syndrome according to the current UK regulatory instruments. I end the thesis by considering why the HFEA's relatively recent decision to limit client access according to an exclusive list of "serious" and therefore "in principle" test-worthy genetic conditions—understood as legitimate applications for PGD—stands to entrench prejudice, stigma, social bias, and unfair discrimination against the disadvantaged social group of persons living with Down's syndrome.
18

A Christian bioethical perspective on pre-implantation Genetic Diagnosis (PGD) and Genetic Manipulation (GM)

Kotze, Manitza 12 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: With the development and continued developing of medical technology, treatments become available without the time to reflect ethically on them. Given how fast things change in medical technology, it is important to constantly reflect anew. Ethical reflection, however, seems to be lagging far behind bio-technological developments. Pre-implantation Genetic Diagnosis (PGD) and Human Genetic Manipulation (GM) is fast becoming an everyday reality and must therefore be reflected upon. Few Christian bioethical studies have been done on the impact that this could have on the larger populace, especially the local population in South Africa, where only a small percentage would be able to access these possible treatments. This study is motivated by the quest of ethicists in general and Christian ethicists in particular, to respond adequately and appropriately to the challenges posed by bio-technological developments. The study will outline and discuss the various Christian perspectives on PGD and GM. It will be shown that most Christian responses to bio-technological matters are done from within the framework of the doctrine of creation. In response, this study will then discuss a trinitarian perspective on the confession of God as creator and investigate whether this perspective might advance and enrich, and even amend, the quests of Christians to formulate ethical responses to the challenges posed by PGD and GM. I have made the decision to focus, for the most part, only on the work of one theologian, and will therefore be applying the trinitarian doctrine of creation as found in the work of Jürgen Moltmann to the development of a Christian bioethical perspective. Seeing that Christian ethics in general is concerned with human dignity, social justice and wellbeing, as well as moral upliftment, the ethical implications of this type of medical technology in the South African context, with its uneven distribution of wealth and access to medical care, must also be addressed from the perspective of this study. In this regard, the concept of human beings created imago Dei (in the image of God), with inherent human dignity, is of particular importance. / AFRIKAANSE OPSOMMING: Met die ontwikkeling en voortdurende ontwikkeling van mediese tegnologie word behandelinge beskikbaar sonder dat daar tyd is om eties daaroor te reflekteer. Gegewe hoe vinnig dinge verander in mediese tegnologie is dit belangrik om voortdurend nuut te reflekteer. Pre-implantasie Genetiese Diagnose (PGD) en Menslike Genetiese Manipulasie (GM) is vinnig beter om ‘n alledaagse realiteit te word en daarom moet daar daaroor reflekteer word. Daar is min Christelike bio-etiese studies gedoen oor die impak wat dit op die groter samelewing kan hê, veral in die plaaslike bevolking van Suid-Afrika, waar slegs ‘n klein persentasie toegang tot hierdie moontlike behandelinge sal hê. Hierdie studie word gemotiveer deur die poging van etici in die algemeen en Christelike etici spesifiek, om behoorlik en toepaslik te reageer op die uitdagings wat bio-tegnologiese ontwikkelinge bied. Die studie sal die verskillende Christelike perspektiewe op PGD en GM uiteensit en bespreek. Daar sal aangedui word dat die meeste Christelike antwoorde op die bio-tegnologiese kwessies gedoen word binne die raamwerk van die skeppingsleer. In reaksie hierop sal hierdie studie dan 'n trinitariese perspektief op die belydenis van God as Skepper bespreek en ondersoek of hierdie perspektief die poging om ‘n Christelike etiese antword te formuleer op die uitdagings wat PGD en GM bied kan bevorder en verryk, en moontlik selfs wysig. Ek het die besluit geneem om hoofsaaklik net op die werk van een teoloog te fokus, en sal dus die trinitariese skeppingsleer soos gevind in die werk van Jürgen Moltmann toepas tot die ontwikkeling van 'n Christelike bio-etiese perspektief. Aangesien die Christelike etiek in die algemeen gemoeid is met menswaardigheid, maatskaplike geregtigheid en welstand, asook morele opheffing, moet die etiese implikasies van hierdie tipe mediese tegnologie in die Suid-Afrikaanse konteks, met sy ongelyke verspreiding van rykdom en toegang tot mediese sorg, ook aangespreek. In hierdie verband is die konsep van die mens geskep Imago Dei (na die beeld van God), met inherente menswaardigheid, van besondere belang.
19

Preimplantation genetic diagnosis and therapy in humans- Opportunities and risks

Hedberg, Rickard January 2020 (has links)
IntroductionPreimplantation Genetic Diagnosis (PGD) was developed in the 1990s and has been used since to diagnose and discard embryos with genetic conditions or chromosomal abnormalities. CRISPR-Cas9 was discovered in 2012 and has been used in research, but has not become clinical practice on humans yet. CRISPR-Cas9 could potentially be applied to treat and prevent genetic disorders.AimThe aim was to investigate the ethical dilemmas of each method through a set of research questions. The ethics of applying PGD according to Swedish guidelines and applying CRISPR-Cas9 on humans was investigated.MethodologyThis was not a systematic literature review. Instead, articles have been selected based on their explanation of each method and uniqueness or volume of ethical arguments surrounding each method, that is of relevance for the discussed issues.ResultsArguments in favour of PGD addressed among other things the somatic and psychological health of future children and parents along with the economical benefits. Arguments against PGD addressed different dilemmas of discarding an embryo and thereby a future individual. Arguments against CRISPR-Cas9 addressed technical limitations, our limited knowledge of genetics and more. Arguments in favour addressed benefits in clinical medicine and research.ConclusionsPGD according to Swedish guidelines was found to be ethically acceptable, since its restrictive use that have not given room for ethically dubious applications. CRISPR-Cas9 was found not to be safe enough for human applications at this moment due to technical limitations. If these were to be solved, caution and restraint must be urged.
20

Enjeux éthiques et légaux des applications du diagnostic préimplantatoire au Canada

Cousineau, Julie 01 1900 (has links)
"Mémoire présenté à la Faculté des études supérieures en vue de l'obtention du grade de LLM en maîtrise option recherche axe Droit, Biotechnologies et Société" / Le diagnostic préimplantatoire (DPI), issu d'une alliance entre la procréation médicalement assistée et les techniques de diagnostic génétique, met à la disposition des êtres humains des conditions entièrement nouvelles pour le "contrôle de la qualité" des enfants. Sur la base d'un vaste ensemble de critères, telle choix du sexe ou l'élimination d'une maladie génétique, les parents peuvent désormais sélectionner leurs embryons créés par fécondation in vitro en fonction de leurs caractéristiques génétiques. Les applications du DPI suscitent toutefois de nombreuses questions. Pas surprenant que le DPI et ses différentes applications fassent l'objet d'un intense débat éthique; ils requièrent certes la mise en place d'un cadre normatif. En 2004, le Canada a finalement adopté la Loi concernant la procréation médicalement assistée et la recherche connexe (L.C. 2004, ch. 2). À titre de manipulation sur l'embryon, le DPI y est indirectement couvert. L'article 10 (2) établit en ce sens une condition générale concernant la modification, la manipulation, le traitement ou l'utilisation d'un embryon in vitro dont le régime de réglementation et d'autorisation en déterminera les limites. Nous pouvons à juste titre nous demander ce qu'il en sera dans le cas de chacune des applications du DPI. L'une d'entre elles, la sélection du sexe pour des raisons non médicales, est déjà prohibée en vertu du texte de loi. Que prévoiront les règlements pour les autres utilisations du DPI? Le gouverneur en conseil dispose du pouvoir pour désigner les catégories d'activités pouvant faire l'objet d'une autorisation ainsi que pour établir les modalités d'exercice de toute activité réglementée. De quelle nature seront ces règlements? Que doivent-ils ou peuvent-ils contenir? Je m'interroge sur le contrôle juridique des diverses applications de cette technique diagnostique. À cet égard, la France et le Royaume-Uni offrent des modèles normatifs fort intéressants pour le Canada. Au cours de cette analyse j'ai cherché à déterminer lequel de ces deux modèles est le plus adapté à la réalité canadienne en matière de procréation médicalement assistée et de DPI. J'ai d'autre part constaté que le choix d'un modèle dépend de notre position à l'égard de certaines questions éthiques telle l'importance de l'autonomie reproductive (i.e. la liberté de choix des embryons en fonction de critères établis par les individus). / Preimplantation genetic diagnosis (PGD), which results from an alliance between medically assisted reproduction and genetic diagnostic techniques, provides humans with an entirely new means of chiId "quality control." Based on a vast set of criteria, such as sex selection or the elimination of a genetic disorder, parents can now select embryos created via in vitro fertilization according to their genetic characteristics. These applications give rise to numerous questions. It is not surprising that PGD and its various applications are the subject of intense ethical debate; the implementation of a legislative framework is a definite necessity. ln 2004, Canada finally adopted the Act Respecting Assisted Human Reproduction and Related Research (S.C. 2004, ch. 2). PGD is indirectly covered under embryo manipulation. Section 10 (2) sets out general conditions concerning the modification, manipulation, treatment or use of an in vitro embryo-the limits of which are determined by the regulation and authorization framework. We may rightly ask what form this will take in each PGD application. One of them, sex selection for nonmedical reasons, is already prohibited in the text of the Act. What regulatory provisions will be made for other uses of PGD? The Governor-in-Council has the power to designate categories of activities that may be authorized and to establish conditions for the exercise of any regulated activity. What type of regulations will they be? What must they or should they contain? 1 have examined the judicial control of various applications of this diagnostic technique. Both France and the United Kingdom offer normative models of interest to Canada. During this analysis, 1 have endeavoured to determine which of these two models is most suited to the Canadian reality with respect to medically assisted reproduction and PGD. 1 thus noted that the choice of a model also depends on our position on certain ethical issues such as the importance of reproductive autonomy (i.e., freedom of choice of embryos according to criteria established by individuals).

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