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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.
91

Valores de referência para área de secção transversa do cordão e vasos umbilicais aferidos pela ultrassonografia em gestações gemelares dicoriônicas / Reference values for cross-sectional area of the umbilical cord and vessels measured by ultrasound in dichorionic twin pregnancies

Fernandes, Douglas Bandeira 14 May 2014 (has links)
OBJETIVO: Determinar os valores de referência, e examinar a correlação da área de secção transversa do cordão umbilical, e de seus componentes, com a idade gestacional (IG), em gestações gemelares. Examinar a correlação da área de secção transversa do cordão umbilical com o peso fetal estimado (PFE). MATERIAIS E MÉTODOS: Estudo prospectivo longitudinal envolvendo gestações gemelares dicoriônicas, não complicadas. Medidas ultrassonográficas das áreas de secção transversa do cordão umbilical (ASTCU), da veia (AVU) e artérias umbilicais (AAU), e da geleia de Wharton (AGW) foram obtidas em plano adjacente, próximo ao abdômen fetal, a cada três semanas. A correlação entre os parâmetros avaliados e a idade gestacional foi investigada por meio de modelo de regressão polinomial hierárquica, levando-se em consideração a variância segundo a idade gestacional, entre medidas obtidas em fetos da mesma gestação e, entre diferentes gestações. Para cada parâmetro estudado, foram calculados os valores correspondentes aos percentis 5, 10, 50, 90 e 95, para cada semana gestacional. RESULTADOS: Foram realizadas 334 avaliações ultrassonográficas em 44 gestações gemelares, entre 18 e 33 semanas (média: 3,8 ± 0,7 exames/gestação; intervalo médio entre exames: 3,3 ± 0,9 semanas). Os valores log-transformados de todos os parâmetros avaliados apresentaram correlação significativa (p<0,001) com a idade gestacional: Log(ASTCU) = - 2,287498 + 0,149298 x IG - 0,002302 x IG2, desvio-padrão DP = 0,113, R2 = 0,65; Log (AVU) = - 2,721487 + 0,119853 x IG - 0,001507 x IG2, DP=0,165, R2 = 0,58; Log (AAU) = - 4,223546 + 0,195454 x IG - 0,003080 x IG2, DP=0,163, R2 = 0,57; Log (AGW) = - 2,511648 + 0,157737 x IG - 0,002564 x IG2, DP=0,123, R2 = 0,55. A área de secção transversa do cordão umbilical apresentou correlação significativa com o peso fetal estimado (Log (ASTCU) = -1,602447 + 0,554502 x Log (PFE), R2 = 0,65, p < 0,001). CONCLUSÃO: Em gestações gemelares dicoriônicas, a área de secção transversa do cordão umbilical, e de seus componentes, mostram correlação positiva e significativa com a idade gestacional. A área de secção transversa do cordão umbilical também correlaciona-se significativamente com o peso fetal estimado / OBJECTIVE: To determine reference values, and examine the correlation between the cross-sectional area of the umbilical cord, and its components, with gestational age (GA) in twin pregnancies. To examine the correlation between the cross-sectional area of the umbilical cord with the estimated fetal weight (EFW). MATERIALS AND METHODS: A prospective longitudinal study involving uncomplicated dichorionic twin pregnancies. Sonographic measurements of the cross-sectional areas of the umbilical cord (UCCSA), umbilical vein (UVA) and arteries (UAA) and Wharton\'s jelly (WGA) were obtained in a plane adjacent to the fetal abdomen, every three weeks. The correlation between these parameters and gestational age was examined with hierarchical polynomial regression analysis. This modeling took into account the variance according to gestational age, fetuses within the same pregnancy and changes across different pregnancies. For each parameter, 5th, 10th, 50th, 90th and 95th centiles were calculated for each gestational week. RESULTS: 334 ultrasound scans were performed in 44 twin pregnancies, between 18 and 33 weeks (mean: 3.8 ± 0.7 scans/pregnancy, mean interval between scans: 3.3 ± 0.9 weeks). All umbilical cord log-transformed values showed a significant correlation (p < 0.001) with gestational age: Log (UCCSA) = - 2.287498 + 0.149298 x GA - 0.002302 x IG2, SD = standard deviation 0.113, R2 = 0.65, Log (UVA) = - 2.721487 + 0.119853 x GA - 0.001507 x IG2, SD = 0.165, R2 = 0.58, Log (UAA) = - 4.223546 + IG x 0.195454 - 0.003080 x IG2, SD = 0.163, R2 = 0.57, Log (WGA) = - 2.511648 + 0.157737 x GA - 0.002564 x IG2 , SD = 0.123, R2 = 0.55. The cross-sectional area of the umbilical cord also correlated significantly with the estimated fetal weight (Log (UCCSA) = -1.602447 + 0.554502 x Log (EFW), R2 = 0.65, p < 0.001). CONCLUSION: In dichorionic twin pregnancies, the cross-sectional areas of the umbilical cord, and its components, show a positive and significant correlation with gestational age. The cross-sectional area of the umbilical cord also has correlates significantly with the estimated fetal weight
92

Células-tronco mesenquimais derivados da geleia de Wharton na injúria cardiopulmonar e neuroimunomodulação sistêmica na sepse / Wharton\'s Jelly derived mesenchymal stem cells in sepsis-induced cardiopulmonar injury and systemic neuroimmunomodulation

Cóndor Capcha, José Manuel 15 May 2018 (has links)
A sepse causa uma alta taxa de mortalidade no mundo. A fisiopatologia da doença envolve uma rede complexa de mediadores inflamatórios que promovem a lesão de diversos tecidos, além de diversas alterações hemodinâmicas e disfunção do sistema nervoso autonômico (SNA). Assim sabe-se que o sistema nervoso cumpre um papel importante no controle da inflamação sistêmica mediante a via colinérgica anti-inflamatória (VCA) através do receptor nicotínico de acetilcolina alfa7 (alfa7nAChR). O uso das células-tronco mesenquimais (CTM) tem mostrado efeitos benéficos em diversos ensaios clínicos de doenças inflamatórias. Neste contexto, as células-tronco mesenquimais derivadas da geleia de Wharton do cordão umbilical (CTM-GW) tornam-se promissórias, uma vez que essas células são reconhecidas pela regulação da resposta imunológica, reparação neural, efeito anti-apoptose, assim como a melhora da sobrevida na sepse, em modelos experimentais. Nossa hipótese foi de que as CTM-GW poderiam cumprir um papel neuroimunomodulador através da VCA e atenuar a disfunção de múltiplos órgãos em um modelo animal de sepse de ligadura e punção do ceco (LPC). Inicialmente células da matriz do cordão umbilical foram isoladas e caracterizadas de acordo com o consenso internacional vigente. Ratos Wistar machos adultos foram subdivididos em grupos: 1) sham (operação simulada); 2) LPC; 3) LPC+CTM-GW (injetado 106 CTM-GW via intraperitoneal, i.p. 6 h após LPC) e 4) LPC+MLA+CTM-GW (MLA: Metillicaconitine, antagonista do alfa7nAChR, i.p., 5:30 h após LPC e 106 CTM-GW 6h após). Às 24 horas após LPC, foram avaliadas a função cardiovascular, hemodinâmica assim como os outros parâmetros. Interessantemente, o tratamento com CTM-GW na sepse atenuou a disfunção diastólica e protegeu a sensibilidade baroreflexa. Além disso, as CTM-GW estimularam a atividade autonômica, simpática e parassimpática no coração. Observamos que o tratamento celular induziu uma regulação da expressão do receptor alfa7nAChR e TLR4 no baço e no coração, assim como a redução da relação p-STAT3TYR705 e STAT3 total no baço. Outros efeitos importantes e adicionais foram a diminuição da infiltração de leucócitos e a regulação das citocinas pró-inflamatórias pelas células. O bloqueio da VCA usando MLA confirmou que o receptor alfa7nAChR pode ser um provável alvo, chave da ação das CTM entre vários outros mecanismos envolvidos na resposta imune. Finalmente, as CTM-GW conseguiram reduzir a apoptose no pulmão e no baço independentemente da VAC reforçando o conceito de que as células-tronco tem efeitos diversos além da imuno-regulação. Em conclusão, as CTM-GW na sepse foram capazes de atenuar a lesão cardiopulmonar assim como modular a atividade autonômica, reduzindo a inflamação sistêmica, pelo menos em parte, através da via colinérgica anti-inflamatória. Indubitavelmente todos estes efeitos anteriormente descritos e em associação se demonstraram fundamentais no mecanismo de reparo e proteção tecidual em resposta a sepse. Mais estudos pré-clínicos e futuros testes clínicos precisam ser realizados para maior compreensão destes mecanismos bem como uma possível validação terapêutica / Sepsis induces organ dysfunction due to overexpression of the inflammatory host response, involving cardiorespiratory and autonomic dysregulation, thus increasing the associated morbidity and mortality. The cholinergic anti-inflammatory pathway (CAP) is mediated by nervous system through alpha7 nicotinic acetylcholine receptor (alpha7nAChR). This receptor has an important role in systemic inflammation control. Wharton\'s jelly-derived mesenchymal stem cells (WJ-MSCs) are known to express genes and secreted factors related to neurological and immunological protection, as well as to improve survival in experimental sepsis. We hypothesized that WJ-MSCs play a modulatory role through the CAP and attenuate sepsis-induced organ injury in a cecal ligation and puncture (CLP) model. Rats were randomly divided into 4 groups: 1) Control (sham-operated); 2) submitted to CLP without treatment; 3) submitted to CLP and treated with 106 WJ-MSCs 6 h later and 4) CLP+MLA+WJ-MSC group (MLA: Methyllycaconitine, alpha7nAChR antagonist). All experiments were performed 24 h post-surgery. Echocardiographic parameters and heart rate variability were assessed. Importantly, treatment with WJ-MSCs attenuated diastolic heart failure and recovered barorreflex sensitivity. Moreover, WJ-MSCs injection increased cardiac sympathetic and cardiovagal activity. In cardiac and splenic tissue, WJ-MSC treatment downregulated TLR4 and alpha7nAChR expression, as well as it reduced p-STAT3/Total STAT3 ratio in the spleen. In addition, WJ-MSC reduced leukocyte infiltration and pro-inflammatory cytokines, which only were abolished by MLA treatment. Finally, WJ-MSC treatment diminished apoptosis in lung and spleen tissue. Together these findings suggest that treatment with WJ-MSCs appears to protect against sepsis-induced organ injury reducing systemic inflammation, at least in part, through cholinergic anti-inflammatory pathway
93

Valores de referência para área de secção transversa do cordão e vasos umbilicais aferidos pela ultrassonografia em gestações gemelares dicoriônicas / Reference values for cross-sectional area of the umbilical cord and vessels measured by ultrasound in dichorionic twin pregnancies

Douglas Bandeira Fernandes 14 May 2014 (has links)
OBJETIVO: Determinar os valores de referência, e examinar a correlação da área de secção transversa do cordão umbilical, e de seus componentes, com a idade gestacional (IG), em gestações gemelares. Examinar a correlação da área de secção transversa do cordão umbilical com o peso fetal estimado (PFE). MATERIAIS E MÉTODOS: Estudo prospectivo longitudinal envolvendo gestações gemelares dicoriônicas, não complicadas. Medidas ultrassonográficas das áreas de secção transversa do cordão umbilical (ASTCU), da veia (AVU) e artérias umbilicais (AAU), e da geleia de Wharton (AGW) foram obtidas em plano adjacente, próximo ao abdômen fetal, a cada três semanas. A correlação entre os parâmetros avaliados e a idade gestacional foi investigada por meio de modelo de regressão polinomial hierárquica, levando-se em consideração a variância segundo a idade gestacional, entre medidas obtidas em fetos da mesma gestação e, entre diferentes gestações. Para cada parâmetro estudado, foram calculados os valores correspondentes aos percentis 5, 10, 50, 90 e 95, para cada semana gestacional. RESULTADOS: Foram realizadas 334 avaliações ultrassonográficas em 44 gestações gemelares, entre 18 e 33 semanas (média: 3,8 ± 0,7 exames/gestação; intervalo médio entre exames: 3,3 ± 0,9 semanas). Os valores log-transformados de todos os parâmetros avaliados apresentaram correlação significativa (p<0,001) com a idade gestacional: Log(ASTCU) = - 2,287498 + 0,149298 x IG - 0,002302 x IG2, desvio-padrão DP = 0,113, R2 = 0,65; Log (AVU) = - 2,721487 + 0,119853 x IG - 0,001507 x IG2, DP=0,165, R2 = 0,58; Log (AAU) = - 4,223546 + 0,195454 x IG - 0,003080 x IG2, DP=0,163, R2 = 0,57; Log (AGW) = - 2,511648 + 0,157737 x IG - 0,002564 x IG2, DP=0,123, R2 = 0,55. A área de secção transversa do cordão umbilical apresentou correlação significativa com o peso fetal estimado (Log (ASTCU) = -1,602447 + 0,554502 x Log (PFE), R2 = 0,65, p < 0,001). CONCLUSÃO: Em gestações gemelares dicoriônicas, a área de secção transversa do cordão umbilical, e de seus componentes, mostram correlação positiva e significativa com a idade gestacional. A área de secção transversa do cordão umbilical também correlaciona-se significativamente com o peso fetal estimado / OBJECTIVE: To determine reference values, and examine the correlation between the cross-sectional area of the umbilical cord, and its components, with gestational age (GA) in twin pregnancies. To examine the correlation between the cross-sectional area of the umbilical cord with the estimated fetal weight (EFW). MATERIALS AND METHODS: A prospective longitudinal study involving uncomplicated dichorionic twin pregnancies. Sonographic measurements of the cross-sectional areas of the umbilical cord (UCCSA), umbilical vein (UVA) and arteries (UAA) and Wharton\'s jelly (WGA) were obtained in a plane adjacent to the fetal abdomen, every three weeks. The correlation between these parameters and gestational age was examined with hierarchical polynomial regression analysis. This modeling took into account the variance according to gestational age, fetuses within the same pregnancy and changes across different pregnancies. For each parameter, 5th, 10th, 50th, 90th and 95th centiles were calculated for each gestational week. RESULTS: 334 ultrasound scans were performed in 44 twin pregnancies, between 18 and 33 weeks (mean: 3.8 ± 0.7 scans/pregnancy, mean interval between scans: 3.3 ± 0.9 weeks). All umbilical cord log-transformed values showed a significant correlation (p < 0.001) with gestational age: Log (UCCSA) = - 2.287498 + 0.149298 x GA - 0.002302 x IG2, SD = standard deviation 0.113, R2 = 0.65, Log (UVA) = - 2.721487 + 0.119853 x GA - 0.001507 x IG2, SD = 0.165, R2 = 0.58, Log (UAA) = - 4.223546 + IG x 0.195454 - 0.003080 x IG2, SD = 0.163, R2 = 0.57, Log (WGA) = - 2.511648 + 0.157737 x GA - 0.002564 x IG2 , SD = 0.123, R2 = 0.55. The cross-sectional area of the umbilical cord also correlated significantly with the estimated fetal weight (Log (UCCSA) = -1.602447 + 0.554502 x Log (EFW), R2 = 0.65, p < 0.001). CONCLUSION: In dichorionic twin pregnancies, the cross-sectional areas of the umbilical cord, and its components, show a positive and significant correlation with gestational age. The cross-sectional area of the umbilical cord also has correlates significantly with the estimated fetal weight
94

Células-tronco mesenquimais derivados da geleia de Wharton na injúria cardiopulmonar e neuroimunomodulação sistêmica na sepse / Wharton\'s Jelly derived mesenchymal stem cells in sepsis-induced cardiopulmonar injury and systemic neuroimmunomodulation

José Manuel Cóndor Capcha 15 May 2018 (has links)
A sepse causa uma alta taxa de mortalidade no mundo. A fisiopatologia da doença envolve uma rede complexa de mediadores inflamatórios que promovem a lesão de diversos tecidos, além de diversas alterações hemodinâmicas e disfunção do sistema nervoso autonômico (SNA). Assim sabe-se que o sistema nervoso cumpre um papel importante no controle da inflamação sistêmica mediante a via colinérgica anti-inflamatória (VCA) através do receptor nicotínico de acetilcolina alfa7 (alfa7nAChR). O uso das células-tronco mesenquimais (CTM) tem mostrado efeitos benéficos em diversos ensaios clínicos de doenças inflamatórias. Neste contexto, as células-tronco mesenquimais derivadas da geleia de Wharton do cordão umbilical (CTM-GW) tornam-se promissórias, uma vez que essas células são reconhecidas pela regulação da resposta imunológica, reparação neural, efeito anti-apoptose, assim como a melhora da sobrevida na sepse, em modelos experimentais. Nossa hipótese foi de que as CTM-GW poderiam cumprir um papel neuroimunomodulador através da VCA e atenuar a disfunção de múltiplos órgãos em um modelo animal de sepse de ligadura e punção do ceco (LPC). Inicialmente células da matriz do cordão umbilical foram isoladas e caracterizadas de acordo com o consenso internacional vigente. Ratos Wistar machos adultos foram subdivididos em grupos: 1) sham (operação simulada); 2) LPC; 3) LPC+CTM-GW (injetado 106 CTM-GW via intraperitoneal, i.p. 6 h após LPC) e 4) LPC+MLA+CTM-GW (MLA: Metillicaconitine, antagonista do alfa7nAChR, i.p., 5:30 h após LPC e 106 CTM-GW 6h após). Às 24 horas após LPC, foram avaliadas a função cardiovascular, hemodinâmica assim como os outros parâmetros. Interessantemente, o tratamento com CTM-GW na sepse atenuou a disfunção diastólica e protegeu a sensibilidade baroreflexa. Além disso, as CTM-GW estimularam a atividade autonômica, simpática e parassimpática no coração. Observamos que o tratamento celular induziu uma regulação da expressão do receptor alfa7nAChR e TLR4 no baço e no coração, assim como a redução da relação p-STAT3TYR705 e STAT3 total no baço. Outros efeitos importantes e adicionais foram a diminuição da infiltração de leucócitos e a regulação das citocinas pró-inflamatórias pelas células. O bloqueio da VCA usando MLA confirmou que o receptor alfa7nAChR pode ser um provável alvo, chave da ação das CTM entre vários outros mecanismos envolvidos na resposta imune. Finalmente, as CTM-GW conseguiram reduzir a apoptose no pulmão e no baço independentemente da VAC reforçando o conceito de que as células-tronco tem efeitos diversos além da imuno-regulação. Em conclusão, as CTM-GW na sepse foram capazes de atenuar a lesão cardiopulmonar assim como modular a atividade autonômica, reduzindo a inflamação sistêmica, pelo menos em parte, através da via colinérgica anti-inflamatória. Indubitavelmente todos estes efeitos anteriormente descritos e em associação se demonstraram fundamentais no mecanismo de reparo e proteção tecidual em resposta a sepse. Mais estudos pré-clínicos e futuros testes clínicos precisam ser realizados para maior compreensão destes mecanismos bem como uma possível validação terapêutica / Sepsis induces organ dysfunction due to overexpression of the inflammatory host response, involving cardiorespiratory and autonomic dysregulation, thus increasing the associated morbidity and mortality. The cholinergic anti-inflammatory pathway (CAP) is mediated by nervous system through alpha7 nicotinic acetylcholine receptor (alpha7nAChR). This receptor has an important role in systemic inflammation control. Wharton\'s jelly-derived mesenchymal stem cells (WJ-MSCs) are known to express genes and secreted factors related to neurological and immunological protection, as well as to improve survival in experimental sepsis. We hypothesized that WJ-MSCs play a modulatory role through the CAP and attenuate sepsis-induced organ injury in a cecal ligation and puncture (CLP) model. Rats were randomly divided into 4 groups: 1) Control (sham-operated); 2) submitted to CLP without treatment; 3) submitted to CLP and treated with 106 WJ-MSCs 6 h later and 4) CLP+MLA+WJ-MSC group (MLA: Methyllycaconitine, alpha7nAChR antagonist). All experiments were performed 24 h post-surgery. Echocardiographic parameters and heart rate variability were assessed. Importantly, treatment with WJ-MSCs attenuated diastolic heart failure and recovered barorreflex sensitivity. Moreover, WJ-MSCs injection increased cardiac sympathetic and cardiovagal activity. In cardiac and splenic tissue, WJ-MSC treatment downregulated TLR4 and alpha7nAChR expression, as well as it reduced p-STAT3/Total STAT3 ratio in the spleen. In addition, WJ-MSC reduced leukocyte infiltration and pro-inflammatory cytokines, which only were abolished by MLA treatment. Finally, WJ-MSC treatment diminished apoptosis in lung and spleen tissue. Together these findings suggest that treatment with WJ-MSCs appears to protect against sepsis-induced organ injury reducing systemic inflammation, at least in part, through cholinergic anti-inflammatory pathway
95

Infinite regress: the problem of womanhood in Edith Wharton's lesser-read works

Smith, Alex 01 May 2015 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Wharton’s heroines are ordinary women who fight to secure material comfort and create selves that satisfy their emotional and sexual needs. These women often find that the two goals are mutually exclusive, since society strictly dictates appropriate behavior. This code of behavior stems from their relation to men: as objects to be won, as wives, and as mothers. In many instances, women are not even aware of their prescriptive roles and confuse their search for self with a search for security. Material comfort does not nurture Wharton’s heroines’ inner selves and they feel a metaphysical dissatisfaction, often seeking to find contentment through divorce or affairs. What they find in either case is that the cure to their ennui is not material, but mental. Wharton’s women seek a transcendent self—a self that is not dependent upon popular notions of respectability; a spiritual state that is independent from any attachment to social imperatives.
96

Flowers of Rhetoric: The Evolving Use of the Language of Flowers in Margaret Fuller's Dial Sketches and Poetry, Elizabeth Stoddard's The Morgesons, Edith Wharton's Summer, Mary Austin's Santa Lucia and Cactus Thorn, and Susan Glaspell's The Verge

Rhyner, Corinne Kopcik 05 May 2012 (has links)
The language of flowers was a popular phenomenon in the United States in the nineteenth century. This dissertation on American literature looks at several American women authors’ use of the language of flowers in their novels. I examine the use of the language of flowers in Margaret Fuller’s “Magnolia of Lake Pontchartrain,” “Yuca Filamentosa,” and poetry such as “To Sarah,” Elizabeth Stoddard’s The Morgesons, Edith Wharton’s Summer, Mary Austin’s Santa Lucia: A Common Story and Cactus Thorn, and Susan Glaspell’s The Verge. Through analysis of language of flowers dictionaries, historical studies of the language of flowers, feminist history and theory, and close readings of the sketches, poems, novels, and plays themselves, I will show that American women continued to use and be influenced by the language of f lowers for close to a decade. I will also show that these women writers’ use of the language of flowers shows evolving social attitudes toward women and standards of femininity in American society during the nineteenth and early-twentieth century.
97

Edith Wharton's View of Women: Lily Bart in The House of Mirth

Johansson, Monique January 2011 (has links)
In this essay I plan to show how Wharton, through Lily, criticised society, and more specifically its expectations of women. My thesis is that Wharton and her character Lily exposed the upper class society of New York, and its ruthlessness, by voicing a woman’s point of view. Therefore, the main purpose here is to reveal the complexity of the lives women led in order to fulfil society’s expectations and I thereby plan to explore what it was like living in a world governed by strict rules of conduct.
98

3d Patterned Cardiac Tissue Construct Formation Using Biodegradable Materials

Kenar, Halime 01 December 2008 (has links) (PDF)
The heart does not regenerate new functional tissue when myocardium dies following coronary artery occlusion, or is defective. Ventricular restoration involves excising the infarct and replacing it with a cardiac patch to restore the heart to a more efficient condition. The goal of this study was to design and develop a myocardial patch to replace myocardial infarctions. A basic design was developed that is composed of 3D microfibrous mats that house mesenchymal stem cells (MSCs) from umbilical cord matrix (Wharton&rsquo / s Jelly) aligned parallel to each other, and biodegradable macroporous tubings to supply growth media into the structure. Poly(glycerol sebacate) (PGS) prepolimer was synthesized and blended with P(L-D,L)LA and/or PHBV, to produce aligned microfiber (dia 1.16 - 1.37 &amp / #956 / m) mats and macroporous tubings. Hydrophilicity and softness of the polymer blends were found to be improved as a result of PGS introduction. The Wharton&rsquo / s Jelly (WJ) MSCs were characterized by determination of their cell surface antigens with flow cytometry and by differentiating them into cells of mesodermal lineage (osteoblasts, adipocytes, chondrocytes). Cardiomyogenic differentiation potential of WJ MSCs in presence of differentiation factors was studied with RT-PCR and immunocytochemistry. WJ MSCs expressed cardiomyogenic transcription factors even in their undifferentiated state. Expression of a ventricular sarcomeric protein was observed upon differentiation. The electrospun, aligned microfibrous mats of PHBV-P(L-D,L)LA-PGS blends allowed penetration of WJ MSCs and improved cell proliferation. To obtain the 3D myocardial graft, the WJ MSCs were seeded on the mats, which were then wrapped around macroporous tubings. The 3D construct (4 mm x 3.5 cm x 2 mm) was incubated in a bioreactor and maintained the uniform distribution of aligned cells for 2 weeks. The positive effect of nutrient flow within the 3D structure was significant. This study represents an important step towards obtaining a thick, autologous myocardial patch, with structure similar to native tissue and capability to grow, for ventricular restoration.
99

Collagen Scaffolds With In Situ Grown Calcium Phosphate For Osteogenic Differentiation Of Wharton

Karadas, Ozge 01 February 2011 (has links) (PDF)
COLLAGEN IN SITU GROWN CALCIUM PHOSPHATE SCAFFOLDS FOR OSTEOGENIC DIFFERENTIATION OF WHARTON&rsquo / S JELLY AND MENSTRUAL BLOOD STEM CELLS Karadas, &Ouml / zge M.Sc., Department of Biotechnology Supervisor : Prof. Dr. Vasif Hasirci Co-Supervisor: Assoc. Prof. Dr. Gamze Torun K&ouml / se February 2011, 91 pages The importance of developing new techniques for the treatment of bone and joint diseases is increasing continuosly together with the increase of human population and the average life span. Especially bone fractures as a result of osteoporosis are often seen in humans older than 50 years old. The expenses of bone and joint disease operations are very high and the duration of recovery is long. Because of these reasons World Health Organization, The United Nations and 37 countries announced that the years 2000-2010 is the Bone and Joint Decade. Tissue engineering is an alternative approach to clinically applied methods. In this study collagen scaffolds crosslinked with genipin, to improve the stability of foams in culture media, were prepared by lyophilization. To mimic the natural bone structure calcium phosphate mineral phase in the foam was formed by wet chemical precipitation. Collagen concentration (0.75% and 1%, w/v), freezing temperature (-20 oC and -80 oC) of the collagen solution before lyophilization and immersion duration (2x4 h and 2x48 h) of the foams in calcium and phosphate solutions for wet chemical precipitation were changed as process v parameters of foam production. Pore size distribution and porosity analysis as well as compression test were performed for characterization of the scaffolds. The foam with 1% w/v collagen concentration, frozen at -20 oC before lyophilization and immersed for 2x4 h in calcium and phosphate solution was chosen for in vitro cell culture studies. The defined foam had 70% porosity and pore sizes varying between 50 and 200 &mu / m. The elastic modulus and compressive strength of the foam was calculated as 127.1 kPa and 234.5 kPa, respectively. Stem cells isolated from Wharton&rsquo / s jelly (WJ) and menstrual blood (MB) were seeded to foams to compare their osteogenic differentiation. Both cells are isolated from discarded tissues and used in this study as an alternative to the commonly used cells which are isolated by invasive techniques such as bone marrow stem cells. Cells were seeded to collagen foams with and without calcium phosphate (CaP). It was observed that WJ cells proliferated during 21 days on collagen foams without CaP, but MB cell number decreased after day 14. Collagen foams with CaP supported the alkaline phosphate (ALP) activity compared to tissue culture polystyrene (TCPS) and foams without CaP. Contrarily lower cell numbers achieved on CaP containing collagen foams, possibly because of the calcium and phosphate concentration changes in the medium and as the result of osteogenic differentiation. ALP activity of both cell types increased almost 10 times and specific ALP activity (activity per cell) increased 40 times and 150 times for WJ and MB cells, respectively on the CaP containing foams compared to TCPS. Therefore, in this study it was shown that in situ CaP formed collagen foams induce osteogenic differentiation of WJ and MB cells, and these cells isolated from discarded tissues can be used as alternative cell sources in bone tissue engineering applications.
100

As good as gold : money, the market, and morality in American literature, 1857-1914 /

Wilson, Robert Andrew, January 2005 (has links)
Thesis (Ph. D.)--Lehigh University, 2005. / Includes vita. Includes bibliographical references (leaves 225-238).

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