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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.
41

Optimizing embryo culture conditions and spent culture media analysis as predictors of embryo quality and pregnancy

Kaskar, Khalied January 2021 (has links)
Philosophiae Doctor - PhD / The aim of this thesis is first, to evaluate various culture conditions to improve embryo development, and secondly, to analyze spent culture media for any biomarkers that may be predictive of embryo health. Single-step and sequential culture media were compared in both Planer and EmbryoScope™ incubators. Single-step media resulted in better blastocyst development compared to sequential media and the EmbryoScope™ incubation system showed slight improvements in embryo development than the Planer system. The benefits of supplementing the culture medium with either insulin or insulin-like growth factor 1 (IGF-1) or culturing in a 2% O2 environment, using two different strains of mice (hybrid and C57), as well as the suitability of these strains for quality control were compared. In insulin, hybrid embryos were slower to blastulate and had a lower blastocyst rate, whereas C57 embryos were slower to the morula and faster to blastocyst stages, and lower blastocyst rate than the controls. IGF-1 showed no difference in time-lapse morphokinetics (TLM) or blastocyst rates compared to controls in both hybrid and C57 embryos. Under 2% O2, hybrid embryos showed no significant difference in TLM up to the 8-cell stage, but slowed down afterwards, resulting in blastocysts with significantly lower cell counts than the 6% O2 group. The C57 embryos were slower to reach morula and expanded blastocyst, and had lower blastocyst rates in 2%O2 vs 6%O2. The C57 strain had significant slower overall embryo development for all time points than hybrid embryos in insulin, IGF-1 and ultra-low O2, as well as lower blastocyst rates. Measurement of growth differentiation factor 9 (GDF-9) and oxidation-reduction potential (ORP) in spent media as markers for embryo health were evaluated. Day 5 human blastocysts yielded higher pregnancy rates and GDF-9 levels in spent media compared to Day 6 blastocysts, but TLM parameters showed no impact on pregnancy outcome. In Day 6 blastocysts, the non-pregnant group showed significantly faster embryo development compared to the clinically pregnant group up to the 8-cell stage and start of blastulation. GDF-9 did not show any significant differences between non-pregnant and pregnant groups of Day 5 or Day 6 embryo transfers. ORP in spent media from good quality Day 3 embryos that developed into blastocysts were significantly higher than from those that did not, with no difference in control medium ORP. Spent media from arrested embryos showed lower ORP than their corresponding controls. Arrested embryos had slower development at syngamy, morula, blastulation and blastocyst stages. The single step medium in the EmbryoScope™ is the preferred choice for embryo culture. Insulin or IGF-1 media supplementation or 2% O2 culture did not provide any benefit to embryo development. The C57 mouse strain is more sensitive and may be better to detect changes in culture conditions, and therefore better model for quality control assays. GDF-9 values decrease from Day 5 to Day 6 which gives new insight to understanding the role of GDF-9 during embryogenesis. ORP in spent media indicate that embryos that developed into blastocysts did not contribute to ROS, but maintained ORP balance.
42

Právní a etické aspekty ochrany počátku a konce lidského života a jeho důstojnosti / Legal and ethical aspects of the protection of the beginning and end of human life and its dignity

Blažek, Petr January 2011 (has links)
The subject of the following dissertation, as the title states, is to explore legal and ethical aspects of the protection of human life and its dignity. Its aim is not merely to attempt to map the present legal situation regarding the protection of human life in the legal system of the Czech Republic, but also to outline some philosophical and anthropological implications which could have considerable influence on the practical consequences of some legal measures, including general aspects of the protection of human life and the legal regulation of two areas of study chosen by the author, namely assisted reproduction and euthanasia. In this sense the following work does not simply describe the various philosophical- anthropological conceptions in a neutral way, but offers to the reader a possible model which, in the view of the author, best corresponds to the degree of protection that human life and dignity can claim in early and terminal phases, taking a neoscholastic and personalistic view of man and his ontological status, in order to try to deduce from this model ethical implications both in a general sense and in relation to the two above-mentioned areas of application. The aim of the work is thus not only to describe the degree of protection of human life de lege lata, but also by making comparisons...
43

Die implikasies van die mensbeskouing in die Pauliniese briewe vir die morele status van die menslike embrio ten opsigte van stamselnavorsing : 'n teologies-etiese perspektief / J.G. van der Walt.

Van der Walt, Johann George January 2013 (has links)
Stem cell research offers hope to many people suffering from incurable diseases such as Alzheimer's disease, diabetes, heart disease and spinal back injuries. However this poses a moral dilemma because embryos are destroyed during embryonic stem cell research. To determine whether embryonic stem cell research is morally justifiable, two views in respect of a human being were considered: i. a human has a dualistic nature in which his body and soul are two separate entities or ii. his body and soul forms a unity which can not be separated. If a human has a dualistic nature, it means that the embryo is not a human, it does not have a soul because the soul is added later to form a human. The implication of this is that it will be morally justifiable to kill an embryo during embryonic stem cell research. However if body and soul forms a unity which can not be separated, the embryo is a human which is already developing into a full grown human with several stages of development. It will thus not be morally justifiable to kill an embryo as this will violate the sixth commandment, i.e. “Thou shalt not kill.” To determine whether a human’s body and soul is an inseparable unity or whether they are two separate entities, the Pauline letters' view on the human being was investigated. The research method employed was to do a comparative literary study to highlight the different aspects of stem cell research and then exegesis was done in respect of body (σoμα / sōma); soul (ψυχὴ / psychē) and spirit (πνεῦμα / pneuma) in the Pauline letters according to the grammatical-historical method. An electronic Bible Concordance was used to determine the texts in which the above concepts appear. A semantic word analysis was also done to analyse these concepts. Then authoritative commentaries were used to check the findings. The analysis indicated that Paul refers to a human as unity in which body and soul can not be separated. The implication of this finding is that embryonic stem cell research should be dismissed because it will result in the destruction of embryos. Humans will thus be killed in violation of the sixth commandment. On the other hand adult stem cell research should be encouraged because it has the potential to cure diseases which has up to now been incurable. / Thesis (MTh (Ethics))--North-West University, Potchefstroom Campus, 2013.
44

Die implikasies van die mensbeskouing in die Pauliniese briewe vir die morele status van die menslike embrio ten opsigte van stamselnavorsing : 'n teologies-etiese perspektief / J.G. van der Walt.

Van der Walt, Johann George January 2013 (has links)
Stem cell research offers hope to many people suffering from incurable diseases such as Alzheimer's disease, diabetes, heart disease and spinal back injuries. However this poses a moral dilemma because embryos are destroyed during embryonic stem cell research. To determine whether embryonic stem cell research is morally justifiable, two views in respect of a human being were considered: i. a human has a dualistic nature in which his body and soul are two separate entities or ii. his body and soul forms a unity which can not be separated. If a human has a dualistic nature, it means that the embryo is not a human, it does not have a soul because the soul is added later to form a human. The implication of this is that it will be morally justifiable to kill an embryo during embryonic stem cell research. However if body and soul forms a unity which can not be separated, the embryo is a human which is already developing into a full grown human with several stages of development. It will thus not be morally justifiable to kill an embryo as this will violate the sixth commandment, i.e. “Thou shalt not kill.” To determine whether a human’s body and soul is an inseparable unity or whether they are two separate entities, the Pauline letters' view on the human being was investigated. The research method employed was to do a comparative literary study to highlight the different aspects of stem cell research and then exegesis was done in respect of body (σoμα / sōma); soul (ψυχὴ / psychē) and spirit (πνεῦμα / pneuma) in the Pauline letters according to the grammatical-historical method. An electronic Bible Concordance was used to determine the texts in which the above concepts appear. A semantic word analysis was also done to analyse these concepts. Then authoritative commentaries were used to check the findings. The analysis indicated that Paul refers to a human as unity in which body and soul can not be separated. The implication of this finding is that embryonic stem cell research should be dismissed because it will result in the destruction of embryos. Humans will thus be killed in violation of the sixth commandment. On the other hand adult stem cell research should be encouraged because it has the potential to cure diseases which has up to now been incurable. / Thesis (MTh (Ethics))--North-West University, Potchefstroom Campus, 2013.
45

Lidské emryo v perspektivě technik reprodukční medicíny / The Human Embryo in the Perspective of Reproductive Medicine

Halabicová, Věra January 2017 (has links)
Title: The Human Embryo in the Perspective of Reproductive Medicine. Since when one begins to be a human person? In this work, we take into account the issues, which in most cases lead many people to resort to the reproductive medicine, which generally is referred to as the infertility problems. But in some techniques, the reproductive medicine loses up to 80% of human embryos. In the minds of many people, the human embryo is seen only as a cluster of cells. However, is it really just a cluster of cells, or is it already a person at an early stage of development? As far as one is already man, is he now also the human being, of whom are in our Western culture related rights, especially the right to life? Could we then say with a clear conscience that with these techniques we are acting ethically? We dividend our work into six chapters. In the first and second chapter, we will be briefly acquainted with the issues of infertility, of the reproductive medicine techniques, with the development of the human embryo and with handling of the embryos in the course of these techniques. In the third charter, we will present the two major ethical models in our cultural area that have a different point of view on the status of the human embryo. In the fourth chapter, we will look at how to the question of the...
46

Embryo Adoption: Implications of Personhood, Marriage, and Parenthood

McMillen, Brooke Marie 14 April 2008 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / One’s personal claims regarding personhood will influence his moral belief regarding embryo adoption. In Chapter One, I consider the personhood of the human embryo. If the human embryo is a person, we are morally obligated to permit the practice of embryo adoption as an ethical means to save human persons. However, for those who do not claim that an embryo is a person at conception, embryo adoption is not a necessary practice because we have no moral obligation to protect them. There are still others who claim that personhood is gained at some point during gestation when certain mental capacities develop. I offer my own claim that consciousness and sentience as well as the potential to be self-conscious mark the beginning of personhood. Embryo adoption raises several questions surrounding the institution of marriage. Due to its untraditional method of procreation, embryo adoption calls into question the role of procreation within marriage. In Chapter Two, I explore the nature of the marriage relationship by offering Lisa Cahill’s definition of marriage which involves both a spiritual and physical dimension, and then I describe the concept of marriage from different perspectives including a social, religious, and a personal perspective. From a personal perspective, I explore the relationship between marriage and friendship. Finally, I describe how the concept of marriage is understood today and explore the advantages to being married as opposed to the advantages of being single. Embryo adoption changes the way we customarily think about procreation within a family because in embryo adoption, couples are seeking an embryo from another union to be implanted into the woman. This prompts some philosophers to argue that embryo adoption violates the marriage relationship. In Chapter Three, I further consider the impact of embryo adoption on the family as an extension of the marital relationship as well as the impact of embryo adoption on the traditional roles of motherhood and fatherhood. I examine motherhood by looking at how some philosophers define motherhood and when these philosophers claim a woman becomes a mother. After considering these issues regarding motherhood, I examine the same issues surrounding fatherhood. Peg Brand, PhD., Chair

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