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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.
481

Methods and mechanisms to improve endothelial colony forming cell (ECFC) survival and promote ECFC vasculogenesis in three dimensional (3D) collagen matrices in vitro and in vivo

Kim, Hyojin 30 June 2015 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Human cord blood (CB) derived circulating endothelial colony forming cells (ECFCs) display a hierarchy of clonogenic proliferative potential and possess de novo vessel forming ability upon implantation in immunodeficient mice. Since survival of ECFC post-implantation is a critical variable that limits in vivo vasculogenesis, we tested the hypothesis that activation of Notch signaling or co-implantation of ECFC with human platelet lysate (HPL) would enhance cultured ECFC vasculogenic abilities in vitro and in vivo. Co-implantation of ECFCs with Notch ligand Delta-like 1 (DL1) expressing OP9 stromal cells (OP9-DL1) decreased apoptosis of ECFC in vitro and increased vasculogenesis of ECFC in vivo. The co-culture of ECFC with HPL diminished apoptosis of ECFC by altering the expression of pro-survival molecules (pAkt, pBad and Bcl-xL) in vitro and increased vasculogenesis of human EC-derived vessels both in vitro and in vivo. Thus, activation of the Notch pathway by OP9-DL1 stromal cells or co-implantation of ECFC with HPL enhances vasculogenesis and augments blood vessel formation by diminishing apoptosis of the implanted ECFC. The results from this study will provide critical information for the development of a cell therapy for limb and organ re-vascularization that can be applied to recovery of ischemic tissues in human subjects.
482

Incidence and Mortality of Renal Cell Carcinoma after Kidney Transplantation: A Meta-Analysis

Chewcharat, Api, Thongprayoon, Charat, Bathini, Tarun, Aeddula, Narothama R., Boonpheng, Boonphiphop, Kaewput, Wisit, Watthanasuntorn, Kanramon, Lertjitbanjong, Ploypin, Sharma, Konika, Torres-Ortiz, Aldo, Leeaphorn, Napat, Mao, Michael A., Khoury, Nadeen J., Cheungpasitporn, Wisit 17 April 2019 (has links)
BACKGROUND: The incidence and mortality of renal cell carcinoma (RCC) after kidney transplantation (KTx) remain unclear. This study's aims were (1) to investigate the pooled incidence/incidence trends, and (2) to assess the mortality/mortality trends in KTx patients with RCC. METHODS: A literature search was conducted using the MEDLINE, EMBASE and Cochrane databases from inception through October 2018. Studies that reported the incidence or mortality of RCC among kidney transplant recipients were included. The pooled incidence and 95% CI were calculated using a random-effect model. The protocol for this meta-analysis is registered with PROSPERO; no. CRD42018108994. RESULTS: A total of 22 observational studies with a total of 320,190 KTx patients were enrolled. Overall, the pooled estimated incidence of RCC after KTx was 0.7% (95% CI: 0.5-0.8%, = 93%). While the pooled estimated incidence of de novo RCC in the native kidney was 0.7% (95% CI: 0.6-0.9%, = 88%), the pooled estimated incidence of RCC in the allograft kidney was 0.2% (95% CI: 0.1-0.4%, = 64%). The pooled estimated mortality rate in KTx recipients with RCC was 15.0% (95% CI: 7.4-28.1%, = 80%) at a mean follow-up time of 42 months after RCC diagnosis. While meta-regression analysis showed a significant negative correlation between year of study and incidence of de novo RCC post-KTx (slopes = -0.05, = 0.01), there were no significant correlations between the year of study and mortality of patients with RCC ( = 0.50). Egger's regression asymmetry test was performed and showed no publication bias in all analyses. CONCLUSIONS: The overall estimated incidence of RCC after KTX was 0.7%. Although there has been a potential decrease in the incidence of RCC post-KTx, mortality in KTx patients with RCC has not decreased over time.
483

Clinical, radiological, and pathological features of idiopathic and secondary interstitial pneumonia cases with pleuroparenchymal fibroelastosis undergoing lung transplantation / 胸膜肺実質線維弾性症を伴う特発性間質性肺炎および二次性間質性肺炎の肺移植症例の臨床的、画像的、病理学的特徴

Ikegami, Naoya 23 March 2022 (has links)
京都大学 / 新制・課程博士 / 博士(医学) / 甲第23782号 / 医博第4828号 / 新制||医||1057(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 羽賀 博典, 教授 波多野 悦朗, 教授 溝脇 尚志 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
484

Histopathologische Veränderungen im zentralen Nervensystem nach peripherer Stammzelltransplantation / Histopathological changes found in the central nervous system after peripheral blood stem cell transplantation

Knust, Elisabeth 03 March 2016 (has links)
No description available.
485

Implication of vascular endothelium and interleukin-22 in rejection of cardiac allografts / Implication de l'endothélium vasculaire et de l'interleukine-22 dans le rejet d'allogreffe cardiaque

Kapessidou, Panayota 28 June 2010 (has links)
Cardiac transplantation is governed by complex immunological mechanisms contributing to different types of allograft rejection. Early non-specific graft failure and chronic rejection (cardiac allograft vasculopathy) represent the main limitations for the recipients’ short- and long-term survival respectively. To date, the pathogenesis of both rejection types remains ill-defined. However, it is believed that they are related to an immunologically mediated potent inflammatory process, occurring whether early after transplantation (acute), or lasting for the lifetime of the graft (chronic).<p> <p>The initiating mechanisms of chronic rejection in solid organ transplantation remain ill-defined. Emerging evidence sustains that graft vasculopathy is primarily driven by alloreactive CD4+ T lymphocytes sensitized by the indirect pathway of allorecognition. To date, whereas the nature of APCs involved in this particular pathway has yet to be identified, it appears challenging to speculate that recipient-derived endothelial cells (ECs) repopulating the graft may represent the main cell targets recognized by indirectly primed alloreactive CD4+ T cells to mediate the rejection of cardiac transplants. In the first part of this thesis, we specifically studied the indirect pathway of allorecognition with a transgenic mice (Marilyn mice) model that expresses a T cell receptor (TCR) transgene which recognizes the male antigen H-Y in an I-Ab-restricted fashion. Our results provide evidence that graft endothelium replacement by recipient-type cells expressing MHC Class II molecules is required for the chronic rejection of vascularized cardiac transplants mediated by indirect pathway alloreactive CD4+ T cells.<p><p>The purpose of the second part of the thesis was to investigate the potential implication of interleukin-22 (IL-22), an early phase secreted proinflammatory cytokine of the IL-10 family, in the acute rejection of cardiac allografts. IL-22 was recently described as an effector key modulator of the inflammatory process produced mainly by differentiated CD4+ T cells of the Th17 lineage. As being closely related to IL-10 and IL-17, both involved in the rejection process of vascularized heart allografts, we attempted to determine the precise role of IL-22 in this process. Experiments were conducted with a recently developed murine model deficient for the IL-22 gene (IL-22KO). The results of the second part of the thesis show that IL-22 is not an effector cytokine in cardiac allograft rejection. In contrast, as being early expressed into the allograft, likely IL-22 plays a protective role in the inflammation leading to acute cardiac rejection, probably depending on a neutrophil-related mechanism. <p><p><p>In conjunction with current understanding of inflammatory and antigen-specific events in allografts, overall, our results provide new insights into the mechanisms of chronic and acute cardiac rejection, thus prompting to further interrogations and appealing novel therapeutic strategies. Pharmacologic manipulation of endothelium is challenging. Given their capacity to sense and rapidly respond to the local environment, ECs are the ideal targets for rapid systemic delivery of therapeutic agents. Combination therapy is required to reduce inflammatory reaction and endothelial activation, to modulate endothelial dysfunction and promote endothelial survival. Also, given that IL-22 may alleviate tissue destruction during inflammatory responses, therapies that enhance its production and protective action in the transplanted organs seem attractive to specifically affect tissue responses, without exerting direct effects on the immune response.<p><p><p> / Doctorat en Sciences médicales / info:eu-repo/semantics/nonPublished
486

An investigation into the functional and psychosocial impact of living organ donation

McGregor, Lesley M. January 2010 (has links)
General Abstract Objective: In April 2006, the Scottish Liver Transplant Unit (SLTU) became the first NHS transplant unit in the UK to offer the option of Living Donor Liver Transplantation (LDLT). This represented a unique opportunity to evaluate the functional and psychosocial impact of LDLT upon healthy donors and their recipients. Subsequent aims were to investigate the challenge of introducing LDLT in Scotland and to establish the perceived deterrents and attractions of the procedure. An additional aim was to evaluate the impact of Living Donor Kidney Transplantation (LDKT) upon donors and recipients. Design: A series of cross sectional and longitudinal studies were designed for the purpose of this thesis (3 quantitative, 2 qualitative, and 1 mixed methods). Method: Self report questionnaires were used in each of the quantitative studies, with the addition of neuropsychological computerized tests in two studies. Semi-structured interviews were employed in the qualitative studies. Main Findings: •Prior to its introduction general support for the option of LDLT was found, although it was highlighted that the risk involved was not well understood by the general public. •Since becoming available LDLT has not been a readily acceptable treatment option from the perspective of patients due to the perceived risk for the donor, but it may be considered as a “last option”. Family members were motivated to save their loved one’s life but the personal implications of donating resulted in reconsideration of LDLT. • Staff at the SLTU perceived a lack of family commitment in relation to LDLT, which is explained as a cultural factor contributing to the slow uptake of LDLT. In Scotland, a donation from a younger to an older generation is not easily accepted. This, in addition to patients’ optimism that a deceased donation will arrive, and the poor health of potential donors, is thought to have affected the uptake of LDLT. As has the unit’s conservative approach to the promotion of LDLT. This approach is the result of a perceived reduction in the need for LDLT and a preference to avoid the risk to a healthy donor and conduct transplants with deceased donations. • In over 3 years, only one couple completed LDLT. The recipient showed functional and psychosocial improvement from pre to post procedure, whilst the donor showed slight deterioration in aspects of quality of life 6 weeks post donation, which did not always completely return to a baseline level by 6 months. The donor made sacrifices to provide her husband with a fresh start to life and unmet expectations were found to effect quality of life. •Willingness to become a liver donor is not thought to be influenced by the frame of the information provided. •Like the LDLT donor, LDKT donors experience some functional and psychosocial deterioration at 6 weeks post donation, but donors largely recover by 6 months post donation. However, the anticipated benefit to recipients was not evident and may not be quantifiable until after 6 months post operation. Conclusion: This thesis has added to current knowledge on living organ donation and specifically represents the first psychological evaluation of a UK LDLT programme. The slow uptake of LDLT was unexpected and has resulted in informative, novel research.
487

Kinase MSK1 et bronchiolite oblitérante / Kinase MSK1 and obliterative bronchiolitis

Nemska, Simona 11 September 2012 (has links)
La bronchiolite oblitérante (BO) est la principale cause de décès à long terme après transplantation pulmonaire. La BO se manifeste par une diminution des capacités respiratoires liée à l’obstruction des petites voies aériennes par un tissu inflammatoire et fibroprolifératif. Dans cette thèse nous avons étudié l’hypothèse de l’implication de la kinase nucléaire MSK1 dans la BO. Nous avons utilisé la transplantation hétérotopique de trachée comme modèle murin de BO. La pertinence du choix de ce modèle a été confirmée par l’étude de la re-vascularisation fonctionnelle de la greffe après transplantation. Dans ce modèle nous avons montré une augmentation de l’expression et de l’activité de MSK1 pendant le développement de la BO. Le traitement des souris transplantées avec des inhibiteurs pharmacologiques de MSK1 a permis d’inhiber l’inflammation et la fibroprolifération, montrant le rôle de MSK1 dans la BO. Nous avons également mis en place un essai de criblage utilisant la technologie HTRF pour rechercher de nouveaux inhibiteurs de MSK1. Les résultats décrits dans cette thèse, montrent que la kinase MSK1 est une potentielle cible thérapeutique pour combattre la BO. / Obliterative bronchiolitis (OB) is the chronic rejection after lung transplantation and is the main cause for late death post-transplantation. OB is characterized by decrease of the pulmonary function caused by obstruction of the small airways by inflammatory and fibroproliferative tissue. We studied the hypothesis of the implication of the nuclear kinase MSK1 in the OB. The relevance of the model was demonstrated by showing the rapid functional re-vascularization of the graft. In this model the allograft, shows an increased MSK1 expression and activity. We therefore treated mice with pharmacological inhibitors of the MSK1 activity and we demonstrated an inhibition of the inflammation and the fibroproliferation during OB. We next set up an enzymatic assay using the heterogeneous time-resolved fluorescence, to proceed for a screening for new MSK1 inhibitors. In summary, this study proposed MSK1 as potential therapeutic target to combat OB.
488

Análise da integração do aloenxerto ósseo de crânio criopreservado e irradiado, adicionado de medula óssea autógena: estudo experimental em coelhos / Deep frozen, irradiated calvarial bone allograft added with autogenous bone marrow incorporation analysis. Experimental study in rabbits

Fogaça, Walfredo Cherubini 27 June 2007 (has links)
Buscando alternativas ao enxerto ósseo autógeno para reconstruções craniofaciais, propõe-se a utilização de aloenxerto ósseo de crânio criopreservado, irradiado e enriquecido com medula óssea autógena.Vinte e um coelhos foram sacrificados e tiveram seus ossos parietais retirados, criopreservados e irradiados com irradiação gama em dose de 50kGy. Os aloenxertos foram implantados em defeitos nos crânios de vinte e um receptores. À esquerda implantava-se o aloenxerto ósseo puro e à direita o aloenxerto adicionado de medula óssea autógena. Os coelhos foram sacrificados em duas, cinco e dez semanas e os enxertos submetidos à análise macroscópica e histomorfométrica. Todos os enxertos apresentavam-se fixos ao leito. Os parâmetros histomorfométricos não mostraram diferenças estatisticamente significante. / Searching for alternatives to autogenous bone graft in craniofacial reconstructions, it is proposed deep-frozen, irradiated calvarial bone allograft added with autogenous bone marrow utilization. Twenty and one rabbits were sacrificed and their parietal bones harvest, deep-frozen and gamma irradiated with 50kGy. The allografts were implanted in twenty one other rabbits. At left side only allograft were placed, at right side were put allografts added with autogenous bone marrow. The animals were sacrificed in two, five and ten weeks. Macroscopical examination showed all grafts fixed at the host bone, the histomorphometric analysis did not showed significant statistical differences between the left and right sides.
489

Bioactive thermoresponsive hydrogels for neural tissue engineering

Stabenfeldt, Sarah Elizabeth 14 November 2007 (has links)
Traumatic brain injury (TBI) results in over 50,000 deaths and 80,000 disabilities each year. Current treatment strategies aim to alleviate acute disturbances, but are not able to address the chronic disorders associated with TBI. Neural transplantation is one potential treatment that will provide multifaceted sustained therapy to degenerating injured tissue. Transplantation of multipotent neural stem cells (NSCs) has been shown to enhance functional recovery in TBI models; however, poor cell survival and integration with host tissue potentially restrict the efficacy of such transplants. This limitation may be due to the absence of inherent NSC pro-survival cues (e.g., cell-ECM interactions). Furthermore, the neural injury environment presents cell death factors to transplanted NSCs. It is hypothesized that a 3-D scaffold presenting specific CNS adhesive moieties will enhance donor cell survival and promote differentiation and migration. This project encompassed material development and in vitro characterization. Results highlighted the importance of ligand tethering chemistry and density and also the mechanical integrity of cell scaffold systems. Furthermore, the developed scaffold provides a controlled microenvironment to assess the influence of LN on NSC survival, migration, and differentiation. Lastly, co-delivering NSC with the MC-LN tissue engineered scaffold into a mechanically injured neural co-culture test-bed or in vivo TBI model confirmed the importance of ECM cues for NSC survival and migration, respectively.
490

Análise da integração do aloenxerto ósseo de crânio criopreservado e irradiado, adicionado de medula óssea autógena: estudo experimental em coelhos / Deep frozen, irradiated calvarial bone allograft added with autogenous bone marrow incorporation analysis. Experimental study in rabbits

Walfredo Cherubini Fogaça 27 June 2007 (has links)
Buscando alternativas ao enxerto ósseo autógeno para reconstruções craniofaciais, propõe-se a utilização de aloenxerto ósseo de crânio criopreservado, irradiado e enriquecido com medula óssea autógena.Vinte e um coelhos foram sacrificados e tiveram seus ossos parietais retirados, criopreservados e irradiados com irradiação gama em dose de 50kGy. Os aloenxertos foram implantados em defeitos nos crânios de vinte e um receptores. À esquerda implantava-se o aloenxerto ósseo puro e à direita o aloenxerto adicionado de medula óssea autógena. Os coelhos foram sacrificados em duas, cinco e dez semanas e os enxertos submetidos à análise macroscópica e histomorfométrica. Todos os enxertos apresentavam-se fixos ao leito. Os parâmetros histomorfométricos não mostraram diferenças estatisticamente significante. / Searching for alternatives to autogenous bone graft in craniofacial reconstructions, it is proposed deep-frozen, irradiated calvarial bone allograft added with autogenous bone marrow utilization. Twenty and one rabbits were sacrificed and their parietal bones harvest, deep-frozen and gamma irradiated with 50kGy. The allografts were implanted in twenty one other rabbits. At left side only allograft were placed, at right side were put allografts added with autogenous bone marrow. The animals were sacrificed in two, five and ten weeks. Macroscopical examination showed all grafts fixed at the host bone, the histomorphometric analysis did not showed significant statistical differences between the left and right sides.

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