University of Saint Mary

About: University of Saint Mary is a education organization based out in Leavenworth, Kansas, United States. It is known for research contribution in the topics: Population & Galaxy. The organization has 2276 authors who have published 2399 publications receiving 58990 citations. The organization is also known as: University of St. Mary & University of St Mary.

The optimal length of 'coasting protocol' in women at risk of ovarian hyperstimulation syndrome undergoing in vitro fertilization.

Abstract: Ovarian hyperstimulation syndrome (OHSS) is a serious and potentially life-threatening complication following ovarian stimulation for in vitro fertilization (IVF). Coasting is the practice whereby the gonadotrophins are withheld and the administration of human chorionic gonadotrophin (hCG) is delayed until serum oestradiol (E2) has decreased to what is considered to be a safe level, to prevent the onset of OHSS. This study aimed to assess the length of coasting on the reproductive outcome in women at risk of developing OHSS. Coasting was undertaken when the serum E2 concentrations were > or = 17000 pmol/L but or = 4 days in terms of oocyte maturity, fertilization and embryo cleavage rates. Women in whom coasting lasted for > or = 4 days had significantly fewer oocytes retrieved (P < 0.05) and decreased implantation rate (P < 0.05) compared to those coasted for 1 - 3 days. Pregnancy rate/embryo transfer and live birth rate did not differ between groups. In conclusion, coasting appears to decrease the risk of OHSS without compromising the IVF cycle pregnancy outcome. Prolonged coasting is, however, associated with reduced implantation rates, perhaps due to the deleterious effects on the endometrium rather than the oocytes.

Differential cytotoxicity and DNA-damaging effects produced in human cells of the Mer+ and Mer- phenotypes by a series of alkyltriazenylimidazoles.

Abstract: A series of alkyltriazenylimidazoles have been investigated for their differential cytotoxicity towards the HT-29 (Mer+) and BE (Mer-) cell lines and for their ability to cause DNA strand breaks and cross-links. A monomethyltriazene, and some hydroxymethyltriazene derivatives capable of generating the monomethyltriazene in situ, were preferentially cytotoxic towards the BE cell line compared with the HT-29 cell line, with very close similarity in the differential toxicity to the analogous monochloroethyltriazene. In contrast, the dimethyl- and monoethyltriazenes in the series display reduced toxicity towards the BE cell line with little or no differential toxicity between BE and HT-29 cell lines. With another pair of human cell lines, the IMR-90 (Mer+) and VA-13 (Mer-) cells, the monomethyl- and monochloroethyltriazenes were again more cytotoxic to the Mer- cells. Neither the formation of DNA single-strand breaks or DNA-protein cross-links could account for the differential cytotoxicity observed in the Mer+ and Mer- cells. More importantly, the inability of the monofunctional monomethyltriazene to cross-link DNA tends to question the role of DNA inter-strand cross-linking as a mechanism for cell killing by chloroethylating agents.

Granulocyte-macrophage colony-stimulating factor: presence in human follicular fluid, protein secretion and mRNA expression by ovarian cells

Abstract: In recent years it has become evident that a leukocyte-cytokine network contributes to the paracrine regulation of ovarian function. The objectives of this study were to examine the presence of a potent lympho-haemopoietic cytokine, granulocyte-macrophage colony-stimulating factor (GM-CSF), in tissues and fluids from human ovaries. In a prospective study, follicular fluid and plasma were collected from naturally cycling women and women undergoing hyperstimulation for in-vitro fertilization (IVF). Granulosa-lutein cells were collected at the time of oocyte recovery for IVF and corpora lutea were collected at the time of hysterectomy for non-ovarian reasons. Culture supernatants from ovarian cell and tissue cultures were harvested on completion of a 48 h incubation. Immunoactive GM-CSF was measured by enzyme-linked immunosorbent assay, and was found to be present at statistically significantly higher levels in follicular fluid (8.9 +/- 0.7 pg/ml) and plasma (11.3 +/- 0.8 pg/ml) of women undergoing hyperstimulation compared to follicular fluid (5.3 +/- 0.3 pg/ml) and plasma (7.1 +/- 0.5 pg/ml) from naturally cycling women. Immunoactive GM-CSF was also detected in culture supernatants of granulosa-lutein cells (47.6 pg/10(5) cells), early luteal phase corpora lutea (0.52 pg/microgram DNA) and mid-luteal phase corpora lutea (0.98 pg/microgram DNA). Furthermore, transcripts for GM-CSF, and both the alpha and beta subunits of the GM-CSF receptor, were detected by reverse transcription polymerase chain reaction (RT-PCR) in granulosa-lutein cell culture preparations and corpora lutea collected during the early, mid- and late luteal phase of the menstrual cycle. These results show that GM-CSF is expressed and secreted by cells within the human ovary, and, together with the finding of expression of mRNA for GM-CSF receptor, suggest a role for GM-CSF in the local regulation of ovarian events.

Probing the geometry and motion of AGN coronae through accretion disc emissivity profiles

Abstract: To gain a better understanding of the inner disc region that comprises active galactic nuclei it is necessary to understand the pattern in which the disc is illuminated (the emissivity profile) by X-rays emitted from the continuum source above the black hole (corona). The differences in the emissivity profiles produced by various corona geometries are explored via general relativistic ray tracing simulations. Through the analysis of various parameters of the geometries simulated it is found that emissivity profiles produced by point source and extended geometries such as cylindrical slabs and spheroidal coronae placed on the accretion disc are distinguishable. Profiles produced by point source and conical geometries are not significantly different, requiring an analysis of reflection fraction to differentiate the two geometries. Beamed point and beamed conical sources are also simulated in an effort to model jet-like coronae, though the differences here are most evident in the reflection fraction. For a point source we determine an approximation for the measured reflection fraction with the source height and velocity. Simulating spectra from the emissivity profiles produced by the various geometries produce distinguishable differences. Overall spectral differences between the geometries do not exceed 15 per cent in the most extreme cases. It is found that emissivity profiles can be useful in distinguishing point source and extended geometries given high quality spectral data of extreme, bright sources over long exposure times. In combination with reflection fraction, timing, and spectral analysis we may use emissivity profiles to discern the geometry of the X-ray source.