Thesis (Ph. D.)--University of Chicago, Dept. of Ecology and Evolution, Dec. 2003. / Includes bibliographical references. Also available in the Internet.

Includes bibliographical references (p. 104-119).

When the Y chromosome of a Mus musculus domesticus mouse is placed onto the C57BL/6J (B6) inbred genetic background, the XY (B6.Y TIR) progeny develop only ovaries or ovotestes during fetal life. At puberty, while some of the hermaphroditic males become fertile, none of the XY sex-reversed females produce litters. The objective of my study was to clarify the cause of infertility in B6.YTIR females. We have previously demonstrated that the eggs ovulated from B6.YTIR ovaries undergo fertilization efficiently, but cannot develop beyond the 2-cell stage. In the present study, we collected oocytes directly from XY ovaries, and examined their maturation, fertilization and embryonic development in vitro. The results show that the majority of fertilized eggs fail to reach the blastocyst stage. To determine whether developmental incompetence of XY oocytes can be attributed to defects in the oocytes themselves or the surrounding XY somatic cells, we constructed female mouse chimera composed of B6.YTIR and XX BALB/c cells. All chimeric females produced progeny exclusively derived from XX oocytes. For comparison, most of XX ↔ XX chimeric females produced progeny derived from oocytes of either strain. / The ability of XY oocytes to regulate granulosa cell differentiation and functions was assessed in oocyte-cumulus complexes (OCC) in vitro . Microsurgical removal of oocytes prevented cumulus cell expansion and suppressed estradiol production while it promoted progesterone production. Coculture of the oocytectomized OCC with denuded oocytes from either XX or XY ovaries resumed cumulus expansion and the normal endocrine profile. Morphometric analyses indicated that XY oocytes were significantly smaller and their zona pellucida layer thinner than XX oocytes as early as the preantral stage. Furthermore, XY oocytes were attached with fewer cumulus cells in antral follicles. To determine whether developmental incompetence of the zygotes from XY ovaries resides in the nuclear or cytoplasmic component, we exchanged the pronuclei between the zygotes derived from B6.YTIR oocytes and those from XX oocytes and examined their development in vitro. The results indicate that both compartments are defective in the B6.YTIR oocyte. / In conclusion, the XY oocyte becomes cell-autonomously defective in both nuclear and cytoplasmic components during early oogenesis.

A study to determine the prevalence of infertility in females in a patient population attending a general practice in Katlehong was done over seven weeks in 1985. In this study 40.6% out of a total of 143 patients interviewed were found to be infertile. Contributing factors to infertility included an advanced age of patients and use of intra-uterine contraceptive devices. Pelvic inflammatory diseases, fibroid uteri, fixed retroverted uteri and a poor socio-economic status of patients were also found to be associated with infertility. The above factors associated with infertility in females are discussed and recommendations directed to the reduction of infertility are submitted. / Thesis (M.Med.)-University of Natal, Durban, 1987.

Background: Fertility problems in women often cause mental stress. Feelings that women describe during the infertility investigation is jealousy, sorrow, guilt, pain, and anxiety. These women need support and encouragement from the nurse during the investigation. Therefore it is important that nurses understand the women's experiences. Previous studies on women's experiences of infertility are based on interviews. Therefore, this study will focus on women's own stories about their experiences during infertility investigation. Aim: The aim of the study was to describe women's experiences of infertility during the time the investigation is in progress. Method: The study was based on narratives, which in this case means an analysis of biographies. Three autobiographies were analyzed according to Dahlborg-Lyckhages (2006) description of analysis of narratives. Results: Four themes and seven subthemes emerged from the analysis. The results show that women's experiences are characterized by being inadequate, feeling guilt, envy, and the nurse's attitudes that can give sense of desperation or hope. The women's experiences affect their everyday lives and their emotions make them isolate themselves. Conclusion: Motherhood is a central part of the woman's life and identity, to be infertile is perceived as to major pressure that may result in mental stress. To reduce the infertile women´s suffering and mental stress it is important that the nurse shows empathy and understanding

Thesis (M. Phil.)--University of Hong Kong, 2007. / Also available online.

Thesis (M. Phil.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Thesis (Ph. D.)--University of Washington, 1995. / Vita. Includes bibliographical references (leaves [175]-192).

Male factor infertility is a contributing factor in up to 50% of infertile couples. Increasing numbers of couples undergoing assisted reproductive technology (ART) treatment and reports of a possible decline in male fertility suggest that lifestyle, occupational and environmental exposures might impair semen quality. Sperm DNA contains both DNA strand breaks and base damage that has been associated with poor semen quality but few studies have examined the role of double strand breaks (DSBs), a toxic lesion, or DNA damage such as N7-methyldeoxyguanosine (N7-MedG) arising from alkylating agents that can be toxic and mutagenic. The aim of this research was to examine the relationships between exposures, DNA damage and male fertility. Men were recruited from couples attending for ART treatment and they provided information on lifestyle, occupational and environmental exposures as well as a sperm sample. Semen concentration and motility was determined by standard techniques in the neat sample and the prepared sample that underwent density gradient centrifugation for ART treatment. DSBs were measured in individual sperm cells by the neutral Comet assay and N7-MedG levels in sperm DNA by an immunoslot blot assay. Information on ART outcomes (% fertilisation, % cleavage and clinical pregnancy) was collected and associations between DNA damage, exposures, semen quality and ART outcomes were determined. Expression of individual DNA repair proteins was also examined in individual oocytes. Men in manual work had significantly lower semen volumes and higher % immotile sperm. Exposure to dry cleaning fluids and having a fever were associated with a decrease in sperm number and while non-ionizing radiation was associated with an increase in % immotile sperm, X-ray exposure was correlated to a decrease in % progressively motile sperm. Semen parameters were significantly and negatively correlated with DSBs in neat and prepared sperm, and N7-MedG levels in neat sperm. Density gradient centrifugation improved sperm sample quality and decreased DSBs and N7-MedG levels significantly. Successful fertilization of oocytes was negatively associated with DSB levels in neat and prepared sperm and with N7-MedG levels in neat sperm. Lower DSB levels in men were associated with an increased chance of an achieving clinical pregnancy especially in ICSI couples. N7-MedG levels were significantly correlated with driving a car and exposure to detergent or printing inks and dyestuffs. DSBs were correlated negatively with exercise and positively with eating nuts and almonds or exposure to non-ionizing radiation. DNA repair gene expression in individual oocytes showed significant intra and inter-individual variability. Sperm DNA damage can reduce male fertility, but the causes of such damage remain to be identified. The variable ability of individual oocytes to repair this damage may well affect the chance for a successful pregnancy.

No description available.