It has previously been demonstrated that a large percentage of in vitro generated human embryos are chromosomally mosaic. The current thesis investigated this mosaicism in greater detail. It characterized the mosaicism present at each stage of preimplantation development in vitro. It examined the relevance of the different forms of the observed mosaicism to preimplantation embryo wastage, implantation failure, and fetal and placental mosaicism. Finally, it addressed the identification of the chromosomally mosaic embryos during preimplantation genetic diagnosis (PGD). For each of the studies presented within the thesis, blastomeres from "spare" in vitro generated embryos were assessed for chromosomal content using multi-color fluorescence in situ hybridization (FISH) DNA probes. Mosaicism was detected at all stages of preimplantation development, from the 2-cell stage to the blastocyst stage; it comprised of diploid, aneuploid, "chaotic", haploid, and polyploid chromosome patterns. Compared to blastocysts, arrested embryos or embryos at the earlier stages of development, showed a much higher incidence of mosaicism involving "chaotic" imbalances for multiple chromosomes and/or high percentages of abnormal cells. These results indicate that extensive post-zygotic abnormalities impair embryonic development to the blastocyst stage. The presence of mosaicism was not predicted by embryo morphology. Mosaicism may therefore contribute to the low rates of blastocyst formation in vitro and to the high rates of implantation failure following cleavage stage embryo transfer. Probe mixtures comprising of three autosomes, of one autosome and gonosomes, or of five autosomes could be applied for the identification of the mosaic embryos during cleavage stage PGD. Culture of isolated blastomeres from cleavage stage embryos for genetic diagnosis increases the number of cells available for analysis; however, the presence of nuclear defects and mosaicism among the cultured cells indica

Little is known about the factors stimulating placental progesterone (P4) production at the time of the luteo-placental shift (6-8 weeks post-conception). To explore the regulatory mechanism, the effects of various steroids and peptides on the production of P4 by placental explants were studied. / In early placental explant culture P4 production was stimulated by 19-nortestosterone (19-NT), androstenedione (A-dione), 5$ alpha$-androstane-3$ alpha,$17$ beta$ diol (3$ alpha$-diol) and 5$ alpha$-androstane-3$ beta,$17$ beta$ diol (3$ beta$-diol). Of all the compounds tested, 19-NT had maximal effect. At term, P4 production was stimulated only by 3$ beta$-diol. 19-NT and A-dione were poorly aromatized in early placental explants compared to another androgen (Androst-5-ene-3$ beta,$17$ beta$ diol). / In accord with the above observations, placental levels of 19-NT and A-dione were higher in early gestation while the diols were higher in late gestation. / 19-NT stimulated P4 production in early placenta by effects on the conversion of P4 both from 25-hydroxycholesterol and from pregnenolone. The stimulatory influences of A-dione and 3$ alpha$-diol were mediated by increasing the P450scc activity. The specific increase of the conversion of P4 from pregnenolone accounted for the P4 stimulation observed by 3$ beta$- diol treatment of culture. / Cyloheximide (CH) treatment abolished the stimulatory influences of the aforementioned steroids on P4 production except for the initial phase of P4 stimulation by 19-NT, suggesting that all but the latter are dependent on protein synthesis. / P4 production was also stimulated and prolonged to 30 days in the presence of human maternal serum (HMS); a good correlation (r = 0.74, P $<$ 0.05) was seen between the histological appearance of the explants and P4 production. The stimulatory activity of HMS was heat labile, non-dialyzable and non-extractable into an organic solvent, suggesting that it is protein in nature. / In conclusion, this study suggests that 19-NT and A-dione are important for placental P4 production at the time of the luteo-placental shift. For in vitro study of placental hormonal regulation, HMS is a better nutrient supplement than fetal bovine serum.

Using murine models of spontaneous and induced embryo resorption, we have investigated the role of macrophages in the mechanism of early embryo loss. The results showed that macrophage derived nitric oxide was associated with embryo resorption, and that decidual macrophages could be triggered by lipopolysaccharide (LPS) to produce nitric oxide, indicating that the decidual mononuclear cells were primed in situ. Using double immunostaining, we have shown that macrophages were the cellular source of the inducible nitric oxide production. We further showed that embryo abortion can be significantly decreased by inhibiting the production of nitric oxide in vivo. The results presented strongly suggested a role for nitric oxide as an effector molecule in mediating early embryo loss and showed that the in situ activation of decidual macrophages was an early event preceding spontaneous abortion. / It is known that interferon-$ gamma$ (IFN-$ gamma$) is the major cytokine responsible for the priming of macrophages and that LPS can trigger primed macrophages to produce nitric oxide. Therefore, the observation that exogenous LPS induced embryo abortion in most strains of pregnant mice suggested that the decidual macrophages have been previously primed in situ. To investigate the role of IFN-$ gamma$ as a potential priming signal for decidual macrophage activation, we studied the effect of the depletion of IFN-$ gamma$ on LPS induced pregnancy loss. The results showed that IFN-$ gamma$ deficient mice were more resistant to LPS induced abortion than control mice. This suggested that IFN-$ gamma$ was essential for the priming of decidual macrophages and that decidual macrophages from IFN-$ gamma$ deficient mice could not be activated when exposed to LPS both in vivo and in vitro. Our results also showed increased IFN-$ gamma$ mRNA expression simultaneously in the same embryos that also expressed elevated iNOS mRNA, a macrophage activation marker. This suggested that macrophage activation, subsequent nitric oxide production, and spontaneous embryo loss could be a consequence of local IFN-$ gamma$ over production. / While LPS serves as an exogenous triggering factor, endogenous TNF-$ alpha$ is known to trigger NO production by primed macrophages. Therefore, we investigated the role of TNF-$ alpha$, as a second signal, in mediating embryo loss. Our studies showed that the frequency of embryos with significantly increased TNF-$ alpha$ mRNA expression corresponded to the incidence of murine embryo abortion. In addition, the results showed that increased TNF-$ alpha$ mRNA was simultaneously expressed with iNOS mRNA suggesting a potential role for TNF-$ alpha$ in the triggering of decidual macrophages. / In summary, we demonstrated the presence of activated decidual macrophages in murine placentas, and that inducible nitric oxide produced by these macrophages was responsible for embryo death. We further showed that IFN-$ gamma$ was responsible for the priming of decidual macrophages, and that the expression of TNF-$ alpha$, a potential secondary signal was associated with decidual macrophage activation, NO production, and subsequent embryo loss.

Objectives. To determine the relationship between objective stress, subjective reaction, post-traumatic stress disorder (PTSD) symptoms and cortisol in pregnant women exposed to a natural disaster. / Methods. The Impact of Event Scale-Revised (IES-R) was used to measure PTSD symptoms in 193 subjects, and a Storm Questionnaire to assess objective and subjective stress. Seven salivary cortisol samples were collected from each subject; six were obtained between waking and bedtime on the first day, and then a seventh upon waking on the second day. / Results. Both objective stress and subjective reactions to the storm negatively predict cortisol, but size and significance of the effects vary according to trimesters of stress exposure. Across the four pregnancy groups, up to 42% of the variance in cortisol could be explained by objective stress and subjective reactions. / Conclusion. More severe PTSD symptoms are associated with lower cortisol levels, and pregnancy dampens a woman's physiological response to stress.

A prospective study of 116 pregnancies in epileptic women was carried out in order to assess the distribution of newborn growth parameters, and the risk of abnormal outcomes (spontaneous abortions, perinatal deaths, developmental anomalies, deformations or hernias). The putative risk factors associated with these outcomes were assessed by multivariable analyses. Major congenital anomalies were increased and head circumference was decreased relative to the general population. Maternal plasma phenytoin or phenobarbital levels were positively associated with developmental anomalies and total abnormal outcomes. An increase in maternal seizures and/or anticonvulsant drugs, as well as detoxification defects of phenytoin arene oxide metabolites were correlated with decreased head circumference, while family history of seizures was associated with reduced birth weight and/or length. Decreased blood folate levels were correlated with spontaneous abortion and developmental anomalies. The present study suggests that adverse pregnancy outcomes in epileptic women may have heterogeneous multifactorial etiologies and mechanisms.

Thesis (Ph.D.)--University of California, San Francisco, 2005. / Source: Dissertation Abstracts International, Volume: 66-06, Section: B, page: 3054. Adviser: Catherine Chesla.

Thesis (Ph.D.)--University of Missouri - Columbia, 2005. / (UMI)AAI3235141. Adviser: Linda Bullock. Source: Dissertation Abstracts International, Volume: 67-09, Section: B, page: 4976.

Thesis (Ph.D.)--Duquesne University, 2005. / Title from document title page. Abstract included in electronic submission form. Includes bibliographical references (p. 226-240) and index.

Thesis (Ph.D.)--University of California, San Francisco, 2007. / Source: Dissertation Abstracts International, Volume: 68-11, Section: B, page: 7255. Adviser: Kathryn A. Lee.

Thesis (Ph.D.)--Indiana University, Dept. of Educational Leadership and Policy Studies, 2007. / Source: Dissertation Abstracts International, Volume: 68-10, Section: A, page: 4215. Adviser: Luise McCarty. Title from dissertation home page (viewed May 19, 2008).