Thesis (Ph.D.)--University of Western Australia, 2006.

Thesis (M. Div.)--St. Vladimir's Orthodox Theological Seminary, Crestwood, NY, 1994. / Includes bibliographical references (leaves 37-41).

Thesis (M. A.)--Trinity Evangelical Divinity School, Deerfield, Ill., 1998. / Abstract. Includes bibliographical references (leaves 125-134).

[Truncated abstract] In obstetric practice, pregnant women at risk of pre-term delivery between 24 and 34 weeks of gestation are administered synthetic glucocorticoids (betamethasone or dexamethasone) to induce fetal organ maturation. During this gestational period, the fetal kidney is undergoing a phase of rapid organogenesis with an increase in renal growth and active nephrogenesis occurring. The studies comprising this thesis examine the effects of prenatal betamethasone exposure on the fetal and adult ovine kidney. The central hypothesis of these studies was that exposure of the fetal kidney to betamethasone in late gestation would change renal structure and induce long-term alterations in the expression of glucocorticoid-sensitive genes and proteins. In the fetal studies, pregnant Merino ewes bearing single fetuses received single or repeated-weekly intra-muscular (i.m.) injections of betamethasone (0.5 mg/kg body weight) or saline commencing on day 104 of gestation (term is 150 days). Kidneys were collected from fetuses at 109, 116, 121 and 146 days of gestation (d). Using gold standard unbiased stereological techniques, the physical disector/fractionator method, total glomerular (nephron) number and glomerular volume were determined in 146 d fetal kidneys exposed to repeated maternal saline or betamethasone administration. In the adult study, kidneys were collected from 3.5-year-old sheep that had been exposed to ... In this thesis I have demonstrated that renal growth restriction as a result of betamethasone exposure is associated with a reduction in fetal nephron endowment. Although betamethasone does not appear to consistently alter nephron number or glomerular size, it may indirectly affect total nephron endowment through effects on renal growth. I have also provided evidence which suggests that lategestation betamethasone exposure in sheep does not program permanent alterations in the renal expression of genes or proteins involved in glucocorticoid hormone action or components of the renin-angiotensin system. Therefore, exposure of the fetal kidney to betamethasone during nephrogenesis may alter renal structure if kidney growth is perturbed; however, there are no persistent alterations in the expression of glucocorticoid-sensitive genes. These findings are consistent with the preservation of normal basal blood pressure in the adult sheep I studied and with the limited results from human studies of late-gestation maternal glucocorticoid administration.

As células tronco mesenquimais derivadas do âmnio (AMSCs) são células multipotentes com alto potencial para se diferenciar em múltiplas linhagens. Podem ser isoladas sem recurso a procedimentos invasivos e usadas sem levantar quaisquer implicações éticas. O presente estudo visa isolar e caracterizar as células mesenquimais progenitoras da membrana amniótica de gatos domésticos para futura aplicação em terapia celular. As células foram isoladas de quatro membranas fetais, coletadas durante as campanhas rotineiras de castração em gatas no último terço de gestação, após anestesia geral. A porção dorsal do âmnio foi separada mecanicamente, lavada com PBS e submetida à digestão com colagenase. As células coletadas foram propagadas em cultivo (DMEN-F12/-MEM) e criopreservadas em várias passagens enquanto se efetuava a avaliação da cinética de crescimento e das características morfológicas. Em cultivo, as AMSCs demonstraram aderência à placa e uma morfologia similar a dos fibroblastos. A análise imunofenotípica revelou presença de marcadores específicos de MSCs CD73 e CD90 e ausência de marcadores hematopoiéticos CD34, CD45 e CD79 sugerindo a presença de células mesenquimais multipotentes na membrana amniótica de gatos domésticos. Em condições apropriadas, estas células diferenciaram-se em linhagens específicas osteogênica e adipogênica. Entretanto, após inoculação em camundongos imunodeficientes não foi registrado formação de teratomas. Estes achados sugerem que o âmnio de gatos domésticos pode ser considerado uma importante fonte de MSCs com maior atração para medicina regenerativa. / The amnion derived mesenchymal stem cells (AMSCs) are multipotent cells with a high ability to differentiate into multiple lineages. They can be obtained by non-invasive methods and therefore are exempt from the normal ethical problems involving stem cell use. The aim of this study was to isolate and characterize the progenitor mesenchymal cells from the cat amniotic membrane for future application in cell therapy. The cells were isolated from four fetal membranes collected after a routine ovarian hysterectomy process from cats in their third gestational trimester, under general anesthesia. The dorsal portion of amnion was mechanically separated, washed with PBS and subjected to collagenase digestion. The isolated cells were propagated in culture media (DMEMF12 or -MEM) and frozen in various passages while the growing kinetics and cell morphology were analyzed. In culture medium, AMSCs were adherent to the plastic culture dish and had a morphology similar to fibroblasts. Immunophenotyping assays showed the presence of MSCs specific markers CD73 and CD90 and absence of hematopoietic markers CD34, CD45 and CD79 suggesting the presence of multipotent mesenchymal cells in the cat amniotic membrane. Under appropriate conditions, these cells differentiated into osteogenic and adipogenic cell lineages. Moreover, after injection into immunodeficient mice, no tumors were generated. These findings suggest that the cat amniotic membrane can be considered an important and useful source of MSCs for regenerative medicine.

As células tronco mesenquimais derivadas do âmnio (AMSCs) são células multipotentes com alto potencial para se diferenciar em múltiplas linhagens. Podem ser isoladas sem recurso a procedimentos invasivos e usadas sem levantar quaisquer implicações éticas. O presente estudo visa isolar e caracterizar as células mesenquimais progenitoras da membrana amniótica de gatos domésticos para futura aplicação em terapia celular. As células foram isoladas de quatro membranas fetais, coletadas durante as campanhas rotineiras de castração em gatas no último terço de gestação, após anestesia geral. A porção dorsal do âmnio foi separada mecanicamente, lavada com PBS e submetida à digestão com colagenase. As células coletadas foram propagadas em cultivo (DMEN-F12/-MEM) e criopreservadas em várias passagens enquanto se efetuava a avaliação da cinética de crescimento e das características morfológicas. Em cultivo, as AMSCs demonstraram aderência à placa e uma morfologia similar a dos fibroblastos. A análise imunofenotípica revelou presença de marcadores específicos de MSCs CD73 e CD90 e ausência de marcadores hematopoiéticos CD34, CD45 e CD79 sugerindo a presença de células mesenquimais multipotentes na membrana amniótica de gatos domésticos. Em condições apropriadas, estas células diferenciaram-se em linhagens específicas osteogênica e adipogênica. Entretanto, após inoculação em camundongos imunodeficientes não foi registrado formação de teratomas. Estes achados sugerem que o âmnio de gatos domésticos pode ser considerado uma importante fonte de MSCs com maior atração para medicina regenerativa. / The amnion derived mesenchymal stem cells (AMSCs) are multipotent cells with a high ability to differentiate into multiple lineages. They can be obtained by non-invasive methods and therefore are exempt from the normal ethical problems involving stem cell use. The aim of this study was to isolate and characterize the progenitor mesenchymal cells from the cat amniotic membrane for future application in cell therapy. The cells were isolated from four fetal membranes collected after a routine ovarian hysterectomy process from cats in their third gestational trimester, under general anesthesia. The dorsal portion of amnion was mechanically separated, washed with PBS and subjected to collagenase digestion. The isolated cells were propagated in culture media (DMEMF12 or -MEM) and frozen in various passages while the growing kinetics and cell morphology were analyzed. In culture medium, AMSCs were adherent to the plastic culture dish and had a morphology similar to fibroblasts. Immunophenotyping assays showed the presence of MSCs specific markers CD73 and CD90 and absence of hematopoietic markers CD34, CD45 and CD79 suggesting the presence of multipotent mesenchymal cells in the cat amniotic membrane. Under appropriate conditions, these cells differentiated into osteogenic and adipogenic cell lineages. Moreover, after injection into immunodeficient mice, no tumors were generated. These findings suggest that the cat amniotic membrane can be considered an important and useful source of MSCs for regenerative medicine.