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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.
31

Detection of porcine umbilical cord matrix stem cells in the intestine and other organs after oral and intraperitoneal administration to allogeneic recipients

Packthongsuk, Kreeson January 1900 (has links)
Doctor of Philosophy / Department of Animal Sciences and Industry / Duane Davis / Umbilical cords matrix stem cells (UCs) have been characterized most thoroughly in humans (HUCs) and are considered to have great promise for regenerative medicine and cell-based therapy. Although UCs were first identified in pigs the description of porcine UCs (PUCs) is limited. Here we reported some standard mesenchymal stem cell characteristics for PUCs. Development of knowledge about PUCs is useful because the pig is a valuable biomedical model for humans and the species is an important human food source. PUCs were isolated from Wharton’s jelly using an explant technique. They attached on the plastic and showed fibroblast-like morphology. Immunophenotype analysis showed they are positive for CD44, CD90 and CD105 and negative for CD31, CD45 and SLA-DR. Under specific in vitro conditions, PUCs were differentiated to adipocytes, chondrocytes and osteocytes. The growth curve of PUCs exhibited a lag phase, log phase and doubling time of 24, 60 and 13.8 hour respectively. Engraftment potential of allogeneic PUCs administered orally and intraperitoneally (IP) was evaluated. Newborn, 1-day, 1-week, 2-week and 3-week old pigs were administered a dose of fluorescently labeled PUCs (1.1x107 cells/kg body weight) and their tissue incorporation were evaluated using confocal microscopy with confirmation by PCR to detect SRY gene, the Y-chromosome gene of male PUCs in female recipients. One week after PUCs administration, they were found mostly in the gastrointestinal tract and abdominal organs after either oral or intraperitoneal transplantation. The intestinal mucosa layer around the base of villi and intestinal crypts was the main location. PUCs were also detected in thoracic organs, muscle and bone marrow. Additionally, PKH26-labeled fibroblasts labeled were detected in recipient intestine 1 week after IP injection. Donor cells were not found in blood at one week post transplantation. When recipients were sacrificed at 6 h after IP injection PKH26-labeled PUCs were found mostly in omentum and diaphragm by PCR. It is likely these are the primary sites for donor cells in the peritoneal cavity to enter the circulation. Fluorescent in situ hybridization (FISH), using an SRY probe and PCR, demonstrated the PUCs isolated from recipient intestines by enzymatic digestion. Therefore, transplanted PUCs were recovered from the intestinal mucosa and were viable and able to proliferate in vitro.
32

Studium výskytu genotypů lidského parvoviru B19 u pacientů FN Motol / Human parvovirus B19 genotype study among the patients of Motol Univeristy Hospital

Dubišová, Mária January 2018 (has links)
Parvovirus B19 is a common human pathogen that typically infects erythroid progenitors and causes hematological problems such as anemia and aplastic crises. The clinical presentation depends mainly on the immunological status of the patient. PVB19 can cause serious clinical disorders in immunocompromised patients after transplantation. More than 1500 samples from 90 patients who passed the HSCT in 2015 were tested for the presence of PVB19 in this work. This work describes the incidence of the virus and two typical periods of onset of infection in patients after the transplantation. Although several sources report the negative effect of PVB19 infection on the survival of allogeneic graft patients, this work did not confirm this assertion. Also, the results of this work suggest that allogenic grafts are not the main source for transmission, but that it is likely to be reactivated after long-term persistent or latent PVB19 infections. PVB19 is divided into 3 genotypes. Genotype 1 is the most widespread, genotype 2 is very rare in Europe for the last 10 years, and genotype 3 occurs mainly in tropical localities. This work as the first describes the distribution of genotypes in the Czech Republic. More than 130 samples from 125 PVB19 positive patients, stored in the Motol University Hospital from 2004...
33

Efeito aditivo do transplante de células-troncos adultas sobre a perfusão cardíaca pós-infarto em porcos tratados com beta-bloqueador e inibidor da enzima conversora de angiotensiva / Additive effect of transplantation of adult stem cells post-infarction on the cardiac perfusion in pigs treated with beta-blocker and angiotensin-converting enzyme inhibitor

Dariolli, Rafael 23 March 2015 (has links)
Os efeitos benéficos associados à injeção intramiocárdica de células-tronco adultas, obtidos em roedores, não tem sido reproduzidos de modo consistente em modelos animais de grande porte e seres humanos. Neste trabalho testamos a hipótese que o transplante de células-tronco mesenquimais derivadas do tecido adiposo de porcos (pASC) aumenta a perfusão tecidual cardíaca em animais infartados e humanizados pelo tratamento com um inibidor da enzima conversora de angiotensina (iECA) e um ?-bloqueador. Os animais foram submetidos a oclusão da artéria coronária circunflexa esquerda (ACX) e 4 semanas após o IM, 4 grupos foram randomizados para receber injeção intramiocárdica de pASC nas doses de 1, 2 ou 4x10^6 pASC/Kg de massa corporal ou placebo. A análise de perfusão miocárdica foi realizada através da ecocardiografia com perfusão miocárdica em tempo real (ECMTR) utilizando contraste de microbolhas comercialmente disponível antes da injeção de pASC e 4 semanas após o tratamento com as células. Avaliações anatomopatológicas foram realizadas para medir a área de IM e o remodelamento de VE. Oito semanas após o IM, os porcos tratados com a maior dose de pASC mostraram um aumento significativo do fluxo sanguíneo do miocárdio, tanto em áreas remotas (3,9 vezes) como na área de borda do infarto (3,7 vezes) vs. os outros grupos estudados. Neste mesmo grupo, um aumento significativo no número de vasos (cerca de 54 e 56%, área remota e de borda respectivamente) foi observado (p> 0,05 vs. outros grupos). Curiosamente, a área de tecido não perfundido foi menor (em até 38%), enquanto que a razão de afinamento da parede (25%) e a percentagem de fibras de colágeno imaturas (verde/finas) foram maiores no grupo 4 que recebeu 4x10^6 pASC/Kg em comparação com os demais. Além disso, a dose mais elevada de pASCs alogênicas testadas não induziu um aumento da resposta inflamatória celular no VE. Deste modo, os resultados mostram que a injeção intramiocárdica de pASCs alogênicas pós-IM promove aumento da perfusão miocárdica e no número de vaso sanguíneos no VE na ausência de resposta inflamatória celular que podem contribuir para atenuar o remodelamento cardíaco adverso de VE 2 meses após o IM na presença de terapêutica farmacológica padrão / The beneficial effects associated with intramyocardial injection of adult stem cells in rodents have not been consistently reproduced in larger animals and humans. We evaluated the dose of porcine adipose-tissue derived mesenchymal stem cells (pASC) to increase cardiac tissue perfusion in pigs treated with ace-inhibitors and ?-blockers to mimic human management post-MI. Animals were subjected to LCx occlusion and 4 weeks after MI blinded randomized in 4 groups to receive intramyocardial injection of pASC (1, 2 and 4x10^6 pASC/Kg bw) or placebo. Real time myocardial perfusion echocardiography (RTMPE) was conducted using commercial microbubbles before injection and 4 weeks after treatment with pASC. Anatomopathological assessments were performed to evaluated MI area, LV remodeling. Eight weeks after MI, the pigs treated with the highest dose of pASC showed a significant increase of myocardial blood flow in both remote (3.9 times) and border zone (3.7 times) versus the other groups, which was also in agreement with the increase in vessel numbers (about 54 and 56%, respectively) compared to the other groups (p > 0.05). Interestingly, the non-perfused area was reduced (up to 38%) and the thinning ratio was higher (25%) in the 4x10 ^ 6 pASC/Kg.bw group compared with placebo or the other cell groups. In addition, the percentage of immature (thin/green) collagen fibers was greater in group 4 than in the placebo animals. The highest dose of allogeneic pASCs did not elicit an increased cellular inflammatory response in LV. Altogether, we provide evidence that intramyocardial injection of allogeneic pASC post-MI did not elicit cellular inflammatory response and also it increased cardiac perfusion and vessel number when in highest dose, which may have contributed to attenuate the LV adverse remodeling 2 months after the MI
34

Einsatz von Vibrationstraining als supportive Maßnahme begleitend zu allogenen hämatopoetischen Stammzelltransplantationen. Pilotstudie zu Sicherheit, Machbarkeit und Effektivität / Use of vibration training as a supportive measure concomitantly allogeneic hematopoietic stem cell transplantation. Pilot study on safety, feasibility and effectiveness

Troendlin, Florian 09 July 2014 (has links)
No description available.
35

Einfluss CD4+CD25+ regulatorischer T-Zellen auf die hämatopoetische Rekonstitution nach syngener und allogener Stammzelltransplantation in einem dreifach transgenen Mausmodell / Influence of CD4+CD25+ regulatory T cells on hematopoietic recovery after syngeneic and allogeneic stem cell transplantation in a triple transgenic mouse model

Rothe, Katherina 25 May 2011 (has links) (PDF)
Regulatorische CD4+CD25+ T-Zellen (Tregs) stellen eine kleine Zellpopulation dar (1-5% der peripheren Blutzellen), die hauptsächlich für die Regulierung von Immunreaktionen verantwortlich ist. In der vorliegenden Arbeit wurden diese Zellen gemeinsam mit Stammzellen syngen und allogen kotransplantiert, um ihren Effekt auf das Anwachsen der Spenderzellen und die Rekonstitution der Hämatopoese nach Ganzkörperbestrahlung zu untersuchen. Es wurden humanisierte dreifach transgene Empfängermäuse (C57Bl/6-TTG) verwendet (human CD4+, murin CD4-, human HLA-DR+), wodurch sowohl bei syngener als auch bei allogener Transplantation eine Unterscheidung zwischen Spender- und Empfängerzellen möglich ist. Zunächst wurden CD4+CD25+ T-Zellen durch Separation aus Milzzellen bzw. Buffy Coats gewonnen und in vitro mittels Durchflusszytometrie und ELISpot charakterisiert. Anschließend fanden syngene und allogene Transplantationen mit einer Laufzeit von 61 Tagen statt. Überleben und Gewicht wurden täglich ermittelt und außerdem wurden wöchentlich Blutbilder erstellt und durchflusszytometrische Chimärismusanalysen (murines und humanes CD4, CD8, MHC (H2Db, H2Kd)) durchgeführt. Durch die magnetische Separation konnte die FoxP3-Expression der murinen Zellen (Transplantat) von 1,6% in der Ausgangspopulation auf 68,5% in der CD4+CD25+ Population gesteigert werden. In den ELISpot-Assays zeigten diese separierten Zellen, wie für Tregs typisch, keine Produktion von Interleukin-2. Nach syngener Transplantation (Spender: wildtyp C57Bl/6) von 2x106 Knochenmarkzellen und 1x106 CD4+CD25+ T-Zellen überlebten 100% der Tiere, wie zu erwarten war. Dabei setzte bei Tregs-kotransplantierten Tieren die Blutbildung nach bestrahlungsbedingter Leukozytopenie aufgrund bisher nicht bekannter Mechanismen früher wieder ein und der Donor-Zell-Chimärismus war an Tag 19 nach Transplantation signifikant höher als in der Kontrollgruppe. Dies zeigt, dass regulatorische T-Zellen im syngenen Transplantationsmodell einen positiven Effekt auf die Akzeptanz bzw. das Anwachsen des Transplantats haben. Dieses Modell entspricht klinisch einer autologen Transplantation. Nach einer knochenmarkzerstörenden Therapie werden dem Patienten eigene Stammzellen reinfundiert, um die Blutbildung und das Immunsystem wieder in Gang zu bringen. Der Zusatz von regulatorischen T-Zellen zum autologen Stammzelltransplantat könnte das Anwachsen der Zellen beschleunigen und die gefährliche Phase der Immunsuppression, in der es häufig zu Sekundärinfektionen kommt, verkürzen. Die Transplantation der gleichen Zahl von allogenen Spenderzellen (wildtyp Balb/c) führte überraschend zum Tod aller dreifach transgenen Empfängertiere. Der Vergleich zu Experimenten mit wildtyp C57Bl/6-Empfängertieren zeigte, dass dreifach transgene Mäuse sehr viel höhere Zellzahlen im Transplantat zum Überleben benötigen (Daten nicht gezeigt). Das Ausbleiben der Blutbildung nach der Bestrahlung führte zu vermindertem Allgemeinbefinden, gestörter Futter- und Wassseraufnahme und Exsikkose bis zum Tod bzw. aus Tierschutzgründen zur Euthanasie. Durch Erhöhung der Zellzahl im Transplantat auf 1x107 Knochenmark + 5x106 Milzzellen überlebten 25% der Mäuse, bei 3x107 Knochenmark + 5x106 Milzzellen waren es 50%. Anders als im syngenen Modell führte die Kotransplantation 1,5x106 allogener CD4+CD25+ T-Zellen zu 3x107 Knochenmark + 5x106 Milzzellen zum Versterben der Tiere. Dies verdeutlicht, dass regulatorische T-Zellen in diesem allogenen Transplantationsmodell das Anwachsen des Transplantats behindern (Transplantatversagen). Hier gilt es zu klären, ob dieser Effekt spezifisch für die gewählten Mausstämme ist und welche Mechanismen für das Transplantatversagen verantwortlich sind. In einem dreifach transgenen Mausmodell konnte ein positiver Effekt von regulatorischen T-Zellen auf die Rekonstitution der Hämatopoese bei syngener Kotransplantation nachgewiesen werden. Im allogenen Transplantationsmodell hingegen führte die Kotransplantation CD4+CD25+ T-Zellen zum Versterben der Empfänger. Der beschriebene und schon publizierte positive Effekt spenderspezifischer Tregs zur Behandlung von Graft versus Host Disease nach allogener Stammzelltransplantation widerspricht diesen Ergebnissen nicht, da es bei diesen Patienten schon zum Engraftment von hämatopoetischen Stammzellen gekommen ist. Dies hat weitreichende Konsequenzen für die therapeutische Anwendung regulatorischer T-Zellen bei hämatologischen Erkrankungen in der Human- und Veterinärmedizin. / Regulatory CD4+CD25+ T cells (Tregs) represent a small cell population (1-5% of peripheral blood cells) mainly responsible for the regulation of the immune system. In the present work, these cells were cotransplanted with syngeneic and allogeneic stem cells in order to analyze the effect of Tregs on the reconstitution of hematopoiesis after total body irradiation. Humanized triple transgenic hosts (C57Bl/6-TTG) (human CD4+, murine CD4-, human HLA-DR+) were applied allowing differentiation of donor and host cells in syngeneic and allogeneic transplantation settings. Murine and human CD4+CD25+ T cells were magnetically separated out of splenocytes or buffy-coats and characterized in vitro by means of flow cytometry and ELISpot. Afterwards syngeneic and allogeneic transplantation experiments were performed for a period of 61 days. Survival and weight were assessed daily and once a week blood parameters and chimerism analyses (murine and human CD4, CD8, MHC (H2Db/ H2Kd)) were carried out. FoxP3 expression increased from 1,6% in the initial murine cell fraction to 68,5% in the separated CD4+CD25+ T cells. ELISpot assays showed the typical lack of interleukin 2 production of Tregs. After syngeneic transplantation (donor: wildtype C57Bl/6) of 2x106 bone marrow cells and 1x106 CD4+CD25+ T cells, 100% of mice survived what was to be expected. Cotransplanted animals showed earlier reconstitution of hematopoiesis after leukocytopenia and significant higher donor-cell-chimerism on day 19 after transplantation. The mechanisms for this positive effect of Tregs in syngeneic transplantation on the engraftment have to be investigated. This model clinically correspond an autologous transplantation where patients are treated with their own stem cells after a myeloablative treatment (chemotherapy or irradiation). The addition of regulatory T cells to the transplant could accelerate the engraftment and shorten the risky period of immunosuppression. Injection of the same numbers of allogeneic cells (donor: wildtype Balb/c) did not preserve hosts from mortality. Compared to experiments with wildtype recipients, results showed that triple transgenic mice need much higher cell numbers in the transplant for survival (data not shown). The failure of hematopoiesis after irradiation led to reduced general condition, disordered ingestion and exsikkosis leading to death respectively to euthanasia for reasons of protection of animals. By scaling up the cell number in the inoculum to 1x107 bone marrow cells + 5x106 splenocytes 25% of mice survived, with 3x107 bone marrow cells + 5x106 splenocytes survival was 50%. In contrast to syngeneic experiments, cotransplantation of 1,5x106 allogeneic CD4+CD25+ T cells and 3x107 bone marrow cells + 5x106 splenocytes did not prevent animals from mortality. In this allogeneic transplantation model Tregs restrain engraftment (graft failure). It has to be clarified if this effect is specific for the utilized mouse strains and which mechanisms are responsible for the graft failure. In the syngeneic triple transgenic mouse model cotransplantation of CD4+CD25+ T cells showed a positive effect on reconstitution of hematopoiesis after irradiation. In the allogeneic setting however cotransplantation of allogeneic regulatory T cells avoided the engraftment of transplanted cells. The described and published effect of donor-specific Tregs for treatment of graft versus host disease after allogeneic transplantation does not contradict the presented results because treated patients already possessed engrafted hematopoietic stem cells. The results have wide consequences for the therapeutic appliance of regulatory T cells in hematological diseases in human and veterinary medicine.
36

Zytogenetische und klinische Verläufe von älteren Patienten mit fortgeschrittenem MDS unter alleiniger 5-Azacytidin-Therapie im Vergleich zur Therapie mit 5-Azacytidin gefolgt von allogener Stammzelltransplantation / Comparision of the cytogenetic and clinical course between 5 - azacytidine treatment and 5 - azacytidine treatment following allogeneic hematopoietic stem cell transplantation in elderly patients with advanced MDS

Büyüktas, Deram 29 May 2018 (has links)
No description available.
37

Aloenxerto ósseo cortical desvitalizado com nitrogênio líquido – estudo experimental em ovelhas

Albuquerque, Paulo Barros de January 2012 (has links)
Na ortopedia veterinária, o enxerto ósseo é comumente utilizado em uma variedade de procedimentos ou afecções ortopédicas como artrodeses, fusões espinhais, reparo de fraturas, tratamentos de união atrasada e não-união de fraturas, preenchimento de falhas ósseas, osteotomias corretivas e reconstruções após a ressecção de neoplasia óssea. O uso de enxerto ósseo alógeno, comparado com o enxerto autógeno, tem como vantagens menor morbidez e dor pós-cirúrgica, diminuição do tempo cirúrgico e, principalmente, fornecimento de maior volume ósseo para a reconstrução adequada de uma grande falha óssea. As desvantagens do seu uso são os riscos de reação imunológica e transmissão de doenças, além da necessidade da formação de um banco de ossos, o que aumenta os custos e necessita de espaço apropriado. O objetivo do presente trabalho foi avaliar a taxa e a forma de incorporação do aloenxerto ósseo cortical submetido ao congelamento em nitrogênio líquido e inserido em tíbias de ovelhas, visando à preservação do membro locomotor. Seis ovelhas clinicamente sadias, da raça Corriedale, com idade estimada entre dois e três anos, foram submetidas à avaliação radiográfica pré-operatória das tíbias para que fosse descartada qualquer alteração óssea. Simultaneamente, realizou-se a ostectomia da diáfise tibial de duas ovelhas para a retirada de um segmento de 7 cm que, após a remoção do periósteo e da medula óssea, foi imerso em nitrogênio líquido, tendo como finalidade a desvitalização óssea, e implantado imediatamente no outro paciente. A estabilização entre os fragmentos e o implante ósseo foi realizada com placa cirúrgica de compressão dinâmica (PCD). Após os procedimentos cirúrgicos, foram realizadas avaliações clínicas e radiográficas a cada 30 dias até o 180º dia de pós-operatório. Aos 60 dias de pós-operatório já se observava o completo uso funcional do membro operado. A união radiográfica das interfaces proximal e distal e a consolidação óssea ocorreram em tempo médio de 95 dias em todos os animais. Conclui-se que o aloenxerto ósseo cortical submetido ao congelamento em nitrogênio líquido é um método apropriado para a preservação do membro locomotor, tendo em vista que a incorporação do mesmo ocorreu gradualmente e a taxa foi de 100%. / Bone grafting is employed in veterinary orthopedics with a variety of purposes as for arthrodesis, spinal fusions, fracture repairs, treatment of delayed or non-unions, filling bone defects, supporting corrective osteotomy, and as replacement in limb sparing techniques for tumor resection. The allograft bone, in contrast to the autologous bone graft, is associated with less site-donor morbidity and pain, reduced surgical time, and adequate bone supply to fill greater defects. Still, the allogeneic bone, besides requiring the establishment of a bone bank, can be a source of diseases and may induce immunogenic response. This study evaluated the allogeneic cortical bone graft incorporation after submission of the harvested fragment to a bout freezing in liquid nitrogen. Six adult clinically healthy sheep were submitted to a 7cm ostectomy of the tibial diaphysis. After removal of periosteum and bone marrow, the fragment was submersed in liquid nitrogen and implanted in another sheep missing a same-sized segment at the corresponding bone. Stabilization of the allograft in the host bone was accomplished by a dynamic compressive plate (DCP). Clinical and radiographic evaluations were performed in the immediate post-operatory period and in every 30 days for six months after surgery. The proximal and distal host-graft interfaces showed radiographic union at a mean postoperative time of 95 days in all the animals. The cortical bone allograft submitted to liquid nitrogen freezing provided adequate bone healing in the sheep model, representing a feasible alternative for limb preservation techniques.
38

Reparação óssea em enxerto alógeno fresco congelado na calvária de coelhos: análises histológica e histomorfométrica

Macedo, Luís Guilherme Scavone de [UNESP] 06 June 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:35:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-06-06Bitstream added on 2014-06-13T21:07:04Z : No. of bitstreams: 1 macedo_lgs_dr_sjc.pdf: 1328056 bytes, checksum: 2dc22b18ce2b29898eeed7a8c9f63b1d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A utilização de enxerto ósseo autógeno previamente à instalação de implantes osseointegráveis tem apresentado bons resultados, entretanto, a necessidade de uma segunda área cirúrgica como fonte doadora e o grau de morbidade da técnica têm direcionado a busca por alternativas seguras para a reconstrução óssea. O propósito desta pesquisa foi avaliar o efeito do enxerto de osso alógeno fresco congelado, oriundo de Banco de Tecido, em comparação ao autógeno no processo de reparação de enxertos na calvária de coelhos. Foram utilizados 15 coelhos adultos, nos quais foram realizados 2 enxertos em blocos nos ossos parietais, divididos aleatoriamente nos seguintes grupos de acordo com o tratamento: autógeno (A – enxerto com osso autógeno) e alógeno (B – enxerto com osso alógeno processado em Banco). Decorridos 15, 30 e 60 dias, 5 animais foram sacrificados por período, sendo as peças contendo os enxertos processadas para análises histológica e histomorfométrica. Os resultados foram submetidos ao teste RM ANOVA e de comparação múltipla de Tukey, demonstrando diferenças estatisticamente significantes entre os grupos e entre os tempos estudados. Concluímos que o enxerto alógeno promove formação óssea, porém em menor quantidade e de forma mais lenta em comparação ao enxerto autógeno / The use of autogenous bone graft prior to installation of dental implants has shown good results, however, the need for a second surgical site and donor source and degree of morbidity of the technique have led the search for safe alternatives to bone reconstruction. The purpose of this study was to evaluate the effect of allogeneic bone graft, fresh frozen from Bank of tissue, as compared to autograft in the repair of calvarial grafts in rabbits. A total of 15 adult rabbits, in which grafts were performed in two blocks in the parietal bone were divided randomly into four groups according to treatment: autogenous (A - with autogenous bone graft) and allogeneic (B - allogeneic bone graft processed in Bank Bone). After 15, 30 and 60 days, five animals were sacrificed by period, and the pieces containing the grafts were processed for histology and histomorphometry. The results were submitted to the RM ANOVA and Tukey's multiple comparison, statistically significant differences between groups and between time points. We conclude that allograft promotes bone formation, but fewer and more slowly compared to autografts
39

Efeito aditivo do transplante de células-troncos adultas sobre a perfusão cardíaca pós-infarto em porcos tratados com beta-bloqueador e inibidor da enzima conversora de angiotensiva / Additive effect of transplantation of adult stem cells post-infarction on the cardiac perfusion in pigs treated with beta-blocker and angiotensin-converting enzyme inhibitor

Rafael Dariolli 23 March 2015 (has links)
Os efeitos benéficos associados à injeção intramiocárdica de células-tronco adultas, obtidos em roedores, não tem sido reproduzidos de modo consistente em modelos animais de grande porte e seres humanos. Neste trabalho testamos a hipótese que o transplante de células-tronco mesenquimais derivadas do tecido adiposo de porcos (pASC) aumenta a perfusão tecidual cardíaca em animais infartados e humanizados pelo tratamento com um inibidor da enzima conversora de angiotensina (iECA) e um ?-bloqueador. Os animais foram submetidos a oclusão da artéria coronária circunflexa esquerda (ACX) e 4 semanas após o IM, 4 grupos foram randomizados para receber injeção intramiocárdica de pASC nas doses de 1, 2 ou 4x10^6 pASC/Kg de massa corporal ou placebo. A análise de perfusão miocárdica foi realizada através da ecocardiografia com perfusão miocárdica em tempo real (ECMTR) utilizando contraste de microbolhas comercialmente disponível antes da injeção de pASC e 4 semanas após o tratamento com as células. Avaliações anatomopatológicas foram realizadas para medir a área de IM e o remodelamento de VE. Oito semanas após o IM, os porcos tratados com a maior dose de pASC mostraram um aumento significativo do fluxo sanguíneo do miocárdio, tanto em áreas remotas (3,9 vezes) como na área de borda do infarto (3,7 vezes) vs. os outros grupos estudados. Neste mesmo grupo, um aumento significativo no número de vasos (cerca de 54 e 56%, área remota e de borda respectivamente) foi observado (p> 0,05 vs. outros grupos). Curiosamente, a área de tecido não perfundido foi menor (em até 38%), enquanto que a razão de afinamento da parede (25%) e a percentagem de fibras de colágeno imaturas (verde/finas) foram maiores no grupo 4 que recebeu 4x10^6 pASC/Kg em comparação com os demais. Além disso, a dose mais elevada de pASCs alogênicas testadas não induziu um aumento da resposta inflamatória celular no VE. Deste modo, os resultados mostram que a injeção intramiocárdica de pASCs alogênicas pós-IM promove aumento da perfusão miocárdica e no número de vaso sanguíneos no VE na ausência de resposta inflamatória celular que podem contribuir para atenuar o remodelamento cardíaco adverso de VE 2 meses após o IM na presença de terapêutica farmacológica padrão / The beneficial effects associated with intramyocardial injection of adult stem cells in rodents have not been consistently reproduced in larger animals and humans. We evaluated the dose of porcine adipose-tissue derived mesenchymal stem cells (pASC) to increase cardiac tissue perfusion in pigs treated with ace-inhibitors and ?-blockers to mimic human management post-MI. Animals were subjected to LCx occlusion and 4 weeks after MI blinded randomized in 4 groups to receive intramyocardial injection of pASC (1, 2 and 4x10^6 pASC/Kg bw) or placebo. Real time myocardial perfusion echocardiography (RTMPE) was conducted using commercial microbubbles before injection and 4 weeks after treatment with pASC. Anatomopathological assessments were performed to evaluated MI area, LV remodeling. Eight weeks after MI, the pigs treated with the highest dose of pASC showed a significant increase of myocardial blood flow in both remote (3.9 times) and border zone (3.7 times) versus the other groups, which was also in agreement with the increase in vessel numbers (about 54 and 56%, respectively) compared to the other groups (p > 0.05). Interestingly, the non-perfused area was reduced (up to 38%) and the thinning ratio was higher (25%) in the 4x10 ^ 6 pASC/Kg.bw group compared with placebo or the other cell groups. In addition, the percentage of immature (thin/green) collagen fibers was greater in group 4 than in the placebo animals. The highest dose of allogeneic pASCs did not elicit an increased cellular inflammatory response in LV. Altogether, we provide evidence that intramyocardial injection of allogeneic pASC post-MI did not elicit cellular inflammatory response and also it increased cardiac perfusion and vessel number when in highest dose, which may have contributed to attenuate the LV adverse remodeling 2 months after the MI
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Reparação óssea em enxerto alógeno fresco congelado na calvária de coelhos : análises histológica e histomorfométrica /

Macedo, Luís Guilherme Scavone de. January 2011 (has links)
Orientador: Marco Antonio Bottino / Banca: Lafayette Nogueira Jr. / Banca: Wilson Roberto Sendyk / Banca: Márcia Carneiro Valera Garakis / Banca: Renata Faria / Resumo: A utilização de enxerto ósseo autógeno previamente à instalação de implantes osseointegráveis tem apresentado bons resultados, entretanto, a necessidade de uma segunda área cirúrgica como fonte doadora e o grau de morbidade da técnica têm direcionado a busca por alternativas seguras para a reconstrução óssea. O propósito desta pesquisa foi avaliar o efeito do enxerto de osso alógeno fresco congelado, oriundo de Banco de Tecido, em comparação ao autógeno no processo de reparação de enxertos na calvária de coelhos. Foram utilizados 15 coelhos adultos, nos quais foram realizados 2 enxertos em blocos nos ossos parietais, divididos aleatoriamente nos seguintes grupos de acordo com o tratamento: autógeno (A - enxerto com osso autógeno) e alógeno (B - enxerto com osso alógeno processado em Banco). Decorridos 15, 30 e 60 dias, 5 animais foram sacrificados por período, sendo as peças contendo os enxertos processadas para análises histológica e histomorfométrica. Os resultados foram submetidos ao teste RM ANOVA e de comparação múltipla de Tukey, demonstrando diferenças estatisticamente significantes entre os grupos e entre os tempos estudados. Concluímos que o enxerto alógeno promove formação óssea, porém em menor quantidade e de forma mais lenta em comparação ao enxerto autógeno / Abstract: The use of autogenous bone graft prior to installation of dental implants has shown good results, however, the need for a second surgical site and donor source and degree of morbidity of the technique have led the search for safe alternatives to bone reconstruction. The purpose of this study was to evaluate the effect of allogeneic bone graft, fresh frozen from Bank of tissue, as compared to autograft in the repair of calvarial grafts in rabbits. A total of 15 adult rabbits, in which grafts were performed in two blocks in the parietal bone were divided randomly into four groups according to treatment: autogenous (A - with autogenous bone graft) and allogeneic (B - allogeneic bone graft processed in Bank Bone). After 15, 30 and 60 days, five animals were sacrificed by period, and the pieces containing the grafts were processed for histology and histomorphometry. The results were submitted to the RM ANOVA and Tukey's multiple comparison, statistically significant differences between groups and between time points. We conclude that allograft promotes bone formation, but fewer and more slowly compared to autografts / Doutor

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