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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.
701

Current Medical Treatment of Endocrine Pancreatic Tumors and Future Aspects

Fjällskog, Marie-Louise January 2002 (has links)
We treated 16 patients with somatostatin analogs combined with α-interferon and achieved a biochemical and/or radiological response in 56% (median duration 22 months). We consider this treatment a good alternative for patients who fail during chemotherapy or who do not want to/cannot receive cytotoxic drugs. Thirty-six patients with neuroendocrine tumors were treated with cisplatin combined with etoposide. Of 14 patients with evaluable EPTs, 50% responded radiologically and/or biochemically (median duration 9 months). We consider this treatment useful as first-line medical treatment in aggressive EPTs or in patients failing prior chemotherapy. Twenty-eight tumor tissues from EPTs were examined with immunohistochemistry regarding expression of somatostatin receptors (ssts) 1 to 5 on tumor cells and in intratumoral vessels. We found that sst2 and sst4 were highly expressed on tumor cells and in vessels. However, sst3 and sst5 were lacking in half of the tumor tissues and in most of the vessels. Because of the variability in sst expression, we recommend analysis of each individual’s receptor expression before starting treatment. Endocrine pancreatic tumors (EPTs) are rare with an incidence of 4 per million inhabitants. In the majority of cases they grow slowly, but there are exceptions with very rapidly progressing malignant carcinomas. First-line medical treatment is streptozotocin combined with 5-fluorouracil. We examined 38 tumor samples regarding expression of tyrosine kinase receptors platelet-derived growth factor receptors (PDGFRs), c-kit and epidermal growth factor receptor (EGFR). We found that the receptors were expressed in more than half of the tumor tissues. Further studies will reveal if tyrosin kinase antagonists can be part of the future treatment arsenal.
702

Ligand selective regulation of cell growth by the Ah receptor through activation of TGFβ signaling / Ligand selective regulation of cell growth by the Ah receptor through activation of TGF-beta signaling

Koch, Daniel C. 28 March 2015 (has links)
The Aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor and member of the basic helix-loop-helix Per/ARNT/Sim (bHLH/PAS) family of chemosensors and developmental regulators. As a member of the PAS domain family of transcription factors responsive to exogenous signals, the AhR exerts influence on many processes relating to cellular fate. The activation of AhR is widely associated with toxic endpoints related to dioxin exposure. However, the AhR also activates endogenous gene programs related to development, cellular growth, and differentiation. The AhR is able to bind a variety of ligands, leading to a wide range of biological outcomes. Recent reports have shown that the AhR can mediate tumor suppressive effects. As a ligand-activated transcription factor, the AhR has the potential to actuate a variety of transcriptional programs that are dependent on the AhR ligand. Our central hypothesis is that AhR ligands can be identified that are capable of initiating tumor suppressive functions of the AhR. We utilized complementary cell-based and in silico virtual screening approaches to identify potential AhR ligands. We developed homology models of the AhR ligand-binding domain (LBD) for virtual ligand screening (VLS) of small molecule libraries. This led to the identification of new AhR ligands 5,7- dihydroxyflavanone!and 5-hydroxy-7-methoxyflavone. Additional small molecule libraries were screened in parallel that led to identification of flutamide as a putative AhR ligand. Flutamide is clinically approved for the treatment of prostate cancer due to its ability to antagonize androgen receptor mediated transcription. We investigated the biological effects of flutamide in AhR positive cancer cells that do not express the androgen receptor and found that flutamide inhibited the growth of HepG2 cells. Suppression of AhR expression reversed the anti-proliferative effects of flutamide. We tested 15 structural analogs of flutamide, including the flutamide metabolite 2-hydroxyflutamide for activation of AhR transcriptional activity. Flutamide is unique in its ability to activate the AhR, and suppresses hepatoma cell growth. These data suggests that flutamide-induced AhR transcriptional activity is required to initiate the tumor suppressive effects. We examined changes in cell cycle checkpoint proteins after flutamide treatment and discovered increased expression of cell cycle inhibitory proteins p27[superscript Kip1] and p15[superscript INK]. We also found that transforming Growth Factor β1 (TGFβ1), which regulates both p27[superscript Kip1] and p15[superscript INK], is upregulated by flutamide. We demonstrate that TGFβ1 is upregulated by flutamide in an AhR-dependent manner and is required for suppression of proliferation by flutamide. We identify specific and unique transcriptional signatures of the AhR upon activation by flutamide, that are distinct from the potent AhR agonist 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD). In summary, we characterize flutamide as an AhR ligand and demonstrate its AhR-dependent tumor suppressive effects in hepatoma cells. We provide the first direct evidence that AhR regulates TGFβ signaling in a ligand dependent manner. We demonstrate that the AhR-induced downstream transcriptional signature and subsequent biological effects are specific to the AhR ligand. Our studies have broad impact for characterizing the AhR as a new therapeutic target in hepatocellular carcinoma. / Graduation date: 2013 / Access restricted to the OSU Community at author's request from March 28, 2013 - March 28, 2015
703

Efecto del plasma rico en plaquetas en la incorporación biológica de una plastia tendinosa en un túnel óseo

Ruiz Macarrilla, Leonardo 25 February 2011 (has links)
OBJETIVO El objetivo nuestro proyecto de investigación es demostrar si la presencia de plasma rico en plaquetas (PRP) autólogo, que aporta varios factores de crecimiento en proporciones fisiológicas, en la interfase injerto tendinoso-hueso modifica el proceso de reparación de los tejidos locales en nuestro modelo experimental. MATERIAL Y MÉTODO Diseñamos un estudio de tipo experimental, longitudinal y prospectivo. Diez conejos albinos de Nueva Zelanda son intervenidos en sus 2 extremidades traseras, en una se realiza la técnica Experimental aplicando PRP y la otra sirve de control, sin aplicar PRP . Una vez intervenidos, los animales son divididos en 2 grupos de 5 de forma aleatoria. Un grupo es sacrificado a la 2ª semana y el otro a la 4ª semana postintervención. El área quirúrgica fue estudiada macroscópica, radiográfica, histológica e inmunohistoquímicamente. RESULTADOS El estudio macroscópico y radiográfico de las piezas muestra la presencia de un área de reacción ósea de mayor tamaño en la zona de entrada del tendón en el interior del túnel óseo en el grupo Experimental sacrificado a la 4ª sem. respecto al resto de grupos. Microscópicamente, en ningún corte histológico, tanto de los grupos Control como Experimental, se observa la línea de separación basófila, denominada tidemark190 entre el fibrocartílago mineralizado y el no mineralizado. Si se evidenció la aparición de una mayor cantidad de los elementos tisulares fibrosos, cartilaginosos y osteoides, y un mayor grado de ordenación celular en el fibrocartílago y sustancia osteoide en los grupos Experimentales respecto a sus correspondientes grupos Control. Además se observa la aparición de zonas de anclaje hueso-tendón en dos extremidades del grupo Experimental sacrificado a la 4ª sem., no encontradas en ningún caso Control. En el estudio inmunohistoquímico no apreciamos diferencias en el patrón de distribución del colágeno tipo II entre los distintos grupos, aunque si existe una mayor área de tinción de colágeno tipo II en los grupos Experimentales respecto a sus correspondientes grupos Control, ya que la cantidad de tejido fibrocartilaginoso, en sus variadas formas de presentación, también es mayor en los grupos que recibieron PRP. CONCLUSIONES El análisis de los resultados concluye que macroscópica, radiográfica y microscópicamente, este estudio demuestra que la administración de PRP como fuente de FC afecta al proceso de reparación del autoinjerto tendinoso dentro de un túnel óseo en nuestro modelo experimental. El PRP aceleró la curación, anticipando en el tiempo la aparición de elementos celulares y tisulares propios de fases posteriores del proceso de cicatrización, y además incrementó la cantidad éstos. / EFFECT OF PLATELET RICH PLASMA IN THE BIOLOGIC INCORPORATION OF A TENDON GRAFT IN A BONE TUNNEL Objective: To study the effect of the platelet rich plasma (PRP) in the biological process of tendon healing inside a bone tunnel Material y Methods: We designed an experimental, longitudinal and prospective research study. Ten animals were operated on their back legs (one as Experimental group and the other as Control group). In the Experimental group the tendon of the internal gastrocnemius muscle was cut, infiltrated with PRP, placed in a tibial bone tunnel filled with PRP, and finally, fixed by a bioabsorbable screw. The same procedure was practiced in the Control group without the use of PRP. Five rabbits were sacrificed on the second week and five on the fourth week after surgery. The legs were evaluated macroscopic, radiographic, histologic and immunohistochemically. Results: The macroscopic and radiographic study of the pieces shows the presence of a larger bone reaction area in the entrance of the tendon within the bone tunnel in the Experimental group sacrificed on the fourth week compared to other groups. Microscopically, the "tidemark" isn’t observed between mineralized and unmineralized fibrocartilage in any group . The Experimental group presents a statistically significant greater amount of chondroid tissue, osteoid tissue and trabecular bone, both the second and fourth week. We observe continuity zones between tendinous fibers and bone in some cases of the Experimental group on the fourth week . Immunohistochemically, no appreciable differences in the distribution pattern of type II collagen between the groups could be seen, although there is a greater area of staining in the Experimental group compared to their corresponding Control group Conclusion: The analysis of results and assessment of the comparison established between the research groups concludes that macroscopic, radiographic and microscopically, this study demonstrates that administration of PRP affects the repair process of tendon autograft in a bone tunnel in our experimental model. The PRP accelerated the healing time anticipating the emergence of cellular and tissue elements characteristic of later stages of the healing process, and also increased the amount of them.
704

Le VEGF induit la synthèse du PAF par l’entremise de l’activation du VEGFR-2 : identification des phosphotyrosines impliquées

Rechka, Abdennebi 08 1900 (has links)
Notre laboratoire a démontré que la capacité proinflammatoire du vascular endothelial growth factor (VEGF-A165) implique la synthèse endothéliale du facteur d’activation plaquettaire (PAF) via l’activation du récepteur tyrosine kinase homodimérique VEGFR-2/R-2. La synthèse du PAF requiert l’activation de la p38 MAPK et p42/44 MAPK qui activent la phospholipase A2 secrétée de type V (sPLA2-V). Nous avons découvert que la synthèse aigue de prostacycline (PGI2) induite par le VEGF-A165 requiert l’activation des récepteurs hétérodimériques VEGFR-1/R-2. L’activation sélective des récepteurs du VEGF peut donc agir comme balance dans la synthèse de facteurs pro-(PAF) et anti-(PGI2) inflammatoire. Cependant, les tyrosines impliquées dans la transphosphorylation de VEGFR-2/R-2 menant à la synthèse du PAF sont inconnues. Par mutagenèse dirigée, nous avons effectué des transfections transitoires de cellules endothéliales avec des plasmides codant pour le VEGFR-2 dont les tyrosines ciblées ont été remplacées de façon séquentielle par une phénylalanine. Un vecteur vide pcDNA a été utilisé comme contrôle négatif. La stimulation des cellules endothéliales de l’aorte bovine (BAEC) transfectées avec le VEGF-A165 (1nM) pendant 15 minutes augmente la synthèse du PAF de 300%, laquelle était similaire dans les BAEC non transfectées. Dans les BAEC transfectées avec les vecteurs pcDNA codant pour les mutations Y801F, Y1059F, Y1175F et Y1214F, nous avons observé une réduction de 54, 73, 68, et 57% respectivement de la synthèse du PAF induite par le VEGF par rapport au pcDNA témoin. Nos résultats apportent un nouvel aperçu sur le mécanisme par lequel le VEGF induit la synthèse du PAF qui est connu pour sa contribution dans l’activité pro-inflammatoire du VEGF. / Vascular endothelial growth factor (VEGF) inflammatory effects require acute platelet-activating factor (PAF) synthesis by endothelial cells (EC). We reported that VEGF-mediated PAF synthesis involves the activation of the homodimeric tyrosine kinase receptor VEGFR-2/R-2 which is leading to p38 and p42/44 mitogen-activated protein kinases (MAPKs) and secreted group V phospholipase A2 (sPLA2-V) activation. We also reported that VEGF-A165-mediated prostacyclin (PGI2) synthesis requires VEGFR-1/R-2 heterodimeric receptor activation. Selective activation of VEGF receptors can thus act as a balance in the synthesis of pro-(PAF) and anti-(PGI2) inflammatory factors. It is unknown which VEGFR-2 tyrosine phosphorylation site(s) contribute(s) to PAF synthesis. Bovine aortic endothelial cells (BAEC) were transfected with pcDNA vectors encoding for native VEGF receptor-2 (VEGFR-2) cDNA, or tyrosine phosphorylation sites mutated into phenylalanine (Y801F), (Y1059F), (Y1175F), (Y1214F), and an empty pcDNA vector was used as negative control. Treatment of pcDNA-transfected BAEC with VEGF-A165 (1nM) for 15 minutes increased PAF synthesis by 300%, which was similar to VEGF-mediated PAF synthesis in untransfected BAEC. In BAEC transfected with pcDNA vectors encoding mutated Y801F, Y1059F, Y1175F or Y1214F VEGFR-2 cDNA, we observed a marked reduction of VEGF-mediated PAF synthesis by 54, 73, 68 and 57% respectively as compared to pcDNA-transfected BAEC. Our current data provide novel insight on the mechanisms by which VEGF promotes endothelial PAF synthesis which is known to contribute to VEGF pro-inflammatory activities.
705

The impact of exogenous TGFβ1 on male reproductive function.

McGrath, Leanne Jane January 2008 (has links)
The TGFβ family of cytokines are potent signalling molecules that regulate tissue development, inflammation and immunity. Previous studies in mice with a null mutation in the Tgfb1 gene (TGFβ1-/- mice) implicate a key role for TGFβ1 in male reproductive function. These mice show profound infertility due to an inability to copulate successfully, associated with reduced testosterone and sperm production. The focus of this project was to 1) further characterize mechanisms underpinning reproductive deficiency in male TGFβ1-/- mice, 2) identify a reliable physiological marker of TGFβ1 availability in vivo, and 3) to determine whether exogenous TGFβ1 administration influences TGFβ1 availability and restores fertility. To investigate the causes of unsuccessful copulation by TGFβ1-/- mice, penis morphometry was examined. Penile organ structure, as assessed by scanning electron microscopy, was comparable between genotypes however a superfluous epidermal covering that impeded penile spine protrusion was evident in TGFβ1-/- mice. The epidermal covering was not due to increased epithelial cell proliferation, as measured by Brdu labelling and immunohistology. Behavioural observations of erectile activity showed that TGFβ1-/- mice achieved spontaneous erections albeit at reduced frequency compared to TGFβ1+/+ mice. The efficacy of exogenous TGFβ1 replacement was evaluated by first identifying measures of in vivo TGFβ1 availability and/or function and selecting an effective route of administration. Serum TGFβ1 and testosterone levels were reliable discriminators of TGFβ1 genotype. Gene expression and phagocytic function of peritoneal macrophages revealed no differences between genotypes. Exogenous sources of TGFβ1 for replacement studies included colostrum, naturally occurring in breast milk and recombinant human latent TGFβ1 (rhLTGFβ1). Colostrum did not increase circulating levels and rhTGFβ1 injection caused only transient elevation of serum levels. Thus mini-osmotic pumps were used to deliver a constant supply of cytokine to TGFβ1-/- mice. The fertility status of TGFβ1-/- mice receiving exogenous TGFβ1 was investigated. Reproductive behaviour in response to normal receptive female mice was assessed twice during treatment, on day 7 and day 14. Blood, liver and reproductive tissues were collected at sacrifice. Circulating TGFβ1 was increased in TGFβ1 treated TGFβ1-/- mice above TGFβ1-/- control levels, although this did not affect circulating testosterone. Erectile activity and sperm production were unchanged. Videotaping behaviour with estrous females revealed that the TGFβ1+/+ mice successfully mounted and intromitted, unlike the TGFβ1-/- controls. The TGFβ1-/- mice receiving exogenous TGFβ1 displayed moderately enhanced mounting and intromission behaviour although this remained less frequent than in the TGFβ1+/+ controls. Ejaculation behaviour was not observed in any TGFβ1-/- mice regardless of TGFβ1 replacement, compared to TGFβ1+/+ controls where >90% mice displayed ejaculated. Modest improvement in the copulation activity of the TGFβ1-/- mice receiving exogenous TGFβ1 suggests that systemic TGFβ1 availability can influence reproductive performance in male TGFβ1-/- mice. However since fertility was not restored, locally produced TGFβ1 in the reproductive tract and/or hypothalamic pituitary axis are also implicated in regulating fertility. These findings advance our knowledge of the role of the TGFβ1 cytokine in male reproductive physiology and may have relevance for devising new treatments for infertility and erectile dysfunction in men. / Thesis (Ph.D.) - University of Adelaide, School of Paediatrics and Reproductive Health, 2008
706

Células mononucleares originárias da medula óssea e do tecido adiposo associadas ao plasma rico em plaquetas na cicatrização óssea em cães / Mononuclear cells originating of bone marrow and adipose Tissue associated with platelet-rich plasma in bone healing in dogs

Barbosa, Anna Laeticia da Trindade 15 May 2013 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Alternatives have been proposed to accelerate the tissue repair process, foremost among them the use of stem cells (SC). For implantation of these cells are needed biodegradable carriers, which allow better adhesion, provide a microenvironment suitable for adaptation and cell implantation site. The Platelet Rich Plasma (PRP) is an autologous source and cost of growth factors (GFs), which concentrates platelets and GFs released by them, accelerating bone formation and improving the quality of newly formed bone. It may be a carrier suitable for implantation of SC, therefore, not induce immune responses, and contains factors that induce osteoblastic differentiation. The goal of this work was to evaluate by clinical, biochemical, radiological and histological findings, the use of PRP associated with mononuclear stem cells (MoSC) in the cortical bone healing in dogs. Also proposed to elaborate a PRP protocol efficient in dogs by means of a small volume of whole blood standardize the use of two force plates simultaneously in orthostatic pattern, and comparing this kind with the use of a platform. To evaluate the effectiveness of this association, was used 30 adult dogs, female, mixed breed, weighing between 5 and 10 kg, separated by random draw in six treatments. Was made a failure elliptical 1,0x0,4cm medial cortical diaphyseal tibia of each animal, being completed in accordance with the proposed treatment: solution of sodium chloride 0,9% (G1), PRP (G2), the total fraction of mononuclear cells TFMC originated of bone marrow (G3), stromal vascular fraction - SVF derived of adipose tissue (G4), TFCM associated with PRP (G5) and SVF associated with PRP (G6). In the preoperative period was collected blood for preparation laboratory protocol of PRP, bone marrow collection and adipose tissue, and processing of fractions of MoSC. Were evaluated daily clinical degrees of lameness, radiological, girth before, and biomechanics in the immediate postoperative period, at 7, 14, 21, 30, 37 and 45 days, and biopsies at 15 and 45 days. In biopsy of 15 days, the failure was enlarged to 1,5x0,4cm and treatment redone, which is currently regarded as the immediate postoperative period in subsequent evaluations. The protocol of the PRP showed efficiency made, focusing on average 7,29 ± 3,21 times the original number of platelets from whole blood, from 7,5 ml of blood. The use of two force platforms simultaneously, was successful, without difference between using one or two platforms. In the X-ray analysis and biomechanical G2, G3, G5 and G6 groups were more effective in bone healing and support of the limb, followed by G4, and after G1. Histological evaluation showed higher degree of advancement scar G5 and G6, G4 in sequence and finally G1. Concluding that association MoSC and PRP is effective, being responsible for an early neoangiogenesis, accelerated osteogenesis, with better quality of bone formation, osteoblast density and intense. The groups G5 and G6 are the best adjuvant treatment of bone healing in dogs, followed by G2, after G3, G4 then, and lastly G1. / Alternativas têm sido propostas para acelerar o processo reparativo tecidual, destacando-se entre elas o uso das células-tronco (CT). Para o implante destas células são necessários carreadores biodegradáveis, que permitem melhor adesão, fornecem um microambiente adequado, e favorecem a adaptação celular no local de implantação. O Plasma rico em plaquetas (PRP) é uma fonte autógena e de baixo custo de fatores de crescimento (FCs), que concentra as plaquetas e os FCs liberados por elas, acelerando a formação óssea e melhorando a qualidade do osso neoformado. Pode ser um carreador adequado para o implante das CT, pois, não induz resposta imune, além de conter fatores indutores da diferenciação osteoblástica. O objetivo deste trabalho foi avaliar por estudos clínicos, biomecânicos, radiográficos e histológicos, o uso do PRP associado às células-tronco mononucleares (CTMo) na cicatrização óssea cortical em cães. Também se objetivou elaborar um protocolo de PRP eficiente em cães, por meio de um pequeno volume de sangue total, padronizar o uso de duas plataformas de força, simultaneamente, em padrão ortostático, nesta espécie e comparar com o uso de uma plataforma. Para avaliar a efetividade dessa associação, foram utilizados 30 cães adultos, fêmeas, sem raça definida, pesando entre 5 e 10kg, separados por sorteio aleatório em seis tratamentos. Foi confeccionada uma falha elíptica de 1,0x0,4cm na cortical medial diafisária da tíbia direita de cada animal, sendo preenchida de acordo com o tratamento proposto: solução de cloreto de sódio a 0,9% (G1), PRP (G2), fração total das células mononucleares - FTCM originadas da medula óssea (G3), fração vascular estromal - FVE derivada do tecido adiposo (G4), FTCM associada ao PRP (G5) e FVE associada ao PRP (G6). No período préoperatório foi realizada coleta de sangue, protocolo laboratorial para confecção do PRP, coleta de medula óssea e tecido adiposo, e processamento das frações das CTMo. Realizou-se avaliação clínica diária, dos graus de claudicação, radiográfica, perimetria da coxa antes, e biomecânica no pós-operatório imediato, aos 7, 14, 21, 30, 37 e 45 dias, e biópsias aos 15 e 45 dias. Na biópsia de 15 dias, a falha foi ampliada para 1,5x0,4cm e o tratamento refeito, sendo este momento considerado como o pós-operatório imediato nas avaliações subsequentes. O protocolo de PRP confeccionado demonstrou eficiência, concentrando em média, 7,29 ± 3,21 vezes o número inicial de plaquetas do sangue total, a partir de 7,5ml de sangue. O uso de duas plataformas de força, simultaneamente, obteve sucesso, não havendo diferença entre usar uma ou duas plataformas. Nas análises radiográficas e biomecânicas G2, G3, G5 e G6 foram os grupos mais efetivos na cicatrização óssea e no apoio do membro operado, seguidos de G4, e após G1. Na avaliação histológica e imuno-histoquímica observou-se maior grau de adiantamento cicatricial em G5 e G6, em sequência G4 e por fim G1. Concluí-se que associação CTMo e PRP é eficiente, sendo responsável por uma neoangiogênese precoce, osteogênese acelerada, com melhor qualidade do osso neoformado, e intensa densidade osteoblástica. Os grupos G5 e G6 são os melhores tratamentos adjuvantes da cicatrização óssea em cães, seguidos de G2, após G3, depois G4, e por último G1.
707

Plasticidade de c?lulas tronco mesenquimais de medula ?ssea de ratos na presen?a de meio condicionado do nervo facial e do fator de crescimento fibrobl?stico 2

Lucena, Eudes Euler de Souza 06 June 2014 (has links)
Made available in DSpace on 2014-12-17T15:36:44Z (GMT). No. of bitstreams: 1 EudesESL_TESE.pdf: 7375820 bytes, checksum: c195e08c1d621b363793dbcfb6727636 (MD5) Previous issue date: 2014-06-06 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / A number of evidences show the influence of the growth of injured nerve fibers in Peripheral Nervous System (PNS) as well as potential implant stem cells (SCs) to make it more suitable for nerve regeneration medium. In this perspective, this study aimed to evaluate the plasticity of mesenchymal stem cells from bone marrow of mice in the presence of culture medium conditioned with facial nerve explants (D-10) and fibroblast growth factor-2 (FGF-2). In this perspective, the cells were cultivated only with DMEM (group 1), only with D-10(group 2), only with FGF-2(group 3) or with D-10 and FGF-2(group 4). The growth and morphology were assessed over 72 hours. Quantitative phenotypic analysis was taken from the immunocytochemistry for GFAP, OX-42, MAP-2, β-tubulin III, NeuN and NF-200 on the fourth day of cultivation. Cells cultured with conditioned medium alone or combined with FGF-2 showed distinct morphological features similar apparent at certain times with neurons and glial cells and a significant proliferative activity in groups 2 and 4 throughout the days. Cells cultived only with conditioned medium acquired a glial phenotype. Cells cultured with FGF-2 and conditioned medium expressed GFAP, OX-42, MAP-2, β-tubulin III, NeuN and NF-200. On average, area and perimeter fo the group of cells positive for GFAP and the ?rea of the cells immunostained for OX-42 were higher than those of the group 4. This study enabled the plasticity of mesenchymal cells (MCs) in neuronal and glial nineage and opened prospects for the search with cell therapy and transdifferentiation / Uma s?rie de evid?ncias mostra a influ?ncia do meio no crescimento de fibras nervosas lesadas no Sistema Nervoso Perif?rico (SNP), assim como o potencial do implante de C?lulas Tronco (CTs) em tornar esse meio mais prop?cio ? regenera??o nervosa. Nessa perspectiva, esse estudo teve como objetivo avaliar a plasticidade de c?lulas tronco mesenquimais (CTMs) da medula ?ssea de ratos diante da presen?a de meio de cultura condicionado com explantes de nervo facial (D-10) e fator de crescimento fibrobl?stico-2 (FGF-2). Dessa maneira as c?lulas mesenquimais foram cultivadadas com meio DMEM (grupo 1), s? com meio D-10(grupo 2), s? com FGF-2(grupo 3) ou com meio D-10 e FGF-2(grupo 4). O crescimento e a morfologia celular foram avaliados ao longo de 72 horas. Al?m disso, a avalia??o fenot?pica foi feita a partir da imunocitoqu?mica para GFAP, OX-42, MAP-2, β-tubulina III, NeuN e NF-200 no quarto dia de cultivo. As c?lulas cultivadas com meio condicionado sozinho ou combinado com FGF-2 demonstraram caracter?sticas morfol?gicas semelhantes a neur?nios e c?lulas gliais e uma significativa atividade proliferativa nos grupos 2 e 4 ao longo dos dias. As c?lulas cultivadas com meio condicionado desprovido de tratamento com FGF-2 adquiriram fen?tipo glial demostrando imunorreatividade para GFAP e OX-42. As c?lulas cultivadas com meio condicionado com adi??o de FGF-2 expressaram GFAP, OX-42, MAP-2, β-tubulina III, NeuN e NF-200. Em m?dia, a ?rea e per?metro das c?lulas do grupo 2 positivas para GFAP e a ?rea das c?lulas imunomarcadas para OX-42 foram maiores do que as do grupo 4. O estudo possibilitou a plasticidade de c?lulas mesenquimais (CMs) numa linhagem neuronal e glial e abriu perspectivas para busca de novas t?cnicas com terapia e transdiferencia??o celular
708

Fyziologické a patofyziologické aspekty některých vybraných endokrinopatií. Vztah k metabolizmu tukové tkáně a inzulínové rezistenci / Physiologic and pathophysiologic aspects of selected endocrinopathies. Their relationship to adipose tissue matebolism and insulin resistance

Ďurovcová, Viktória January 2012 (has links)
The pathogenesis of insulin resistance is a complex and still intensively studied issue. Endocrine and paracrine activity of the adipose tissue together with mi- tochondrial dysfunction are the most discussed potential factors included in the development of insulin resistance. In the first part of our study we examined the involvement of the adipose tissue and its secretory products in the etiopathogenesis of insulin resistance in patients with Cushing's syndrome, acromegaly and simple obesity. We focused on three important regulators of metabolic homeostasis - fibroblast growth factors 21 and 19 (FGF-21 and FGF-19) and adipocyte fatty acid binding protein (FABP-4). We found significantly elevated circulating levels of FGF-21 and FABP-4 ac- companying insulin resistance in both patients with simple obesity and patients with obesity connected to Cushing's syndrome, as compared to healthy controls. The concentrations of both substances were comparable between hypercortisolic and obese patients. This finding together with the absence of correlation be- tween the levels of FGF-21 resp. FABP-4 and cortisol suggest that the reason for elevation of their concentrations is obesity and its metabolic consequences themselves rather then the effect of hypercortisolism on FGF-21 and FABP-4 production. We found no...
709

Caracterização da insensibilidade ao fator de crescimento insulina-símile tipo 1 em pacientes com defeitos no receptor tipo 1 de IGFs (IGF-1R) / Characterization of an insensitivity to type 1 insulin-like growth factor in patients with defects in the type 1 IGF receptor (IGF-1R)

Andréa de Castro Leal 13 September 2012 (has links)
Introdução: Crianças nascidas pequenas para a idade gestacional (PIG) apresentam maior risco de permanecerem com baixa estatura na vida adulta. Os fatores de crescimento insulino-símile tipo 1 e 2 (IGF-1 e IGF-2) são os principais fatores endócrinos determinantes do crescimento fetal. A maioria das ações conhecidas destes hormônios é mediada via um receptor tirosina quinase, conhecido como IGF-1R. As mutações inativadoras e deleções do gene do IGF1R em heterozigose vêm sendo relatadas de forma crescente nos últimos 9 anos em pacientes com história de déficit de crescimento pré e pós-natal. Postula-se que pelo menos 2 a 3% das crianças nascidas PIG poderiam apresentar defeitos no IGF1R. O quadro clínico destes pacientes apresenta grande variabilidade quanto à gravidade do retardo de crescimento pré- e pós-natal e aos parâmetros hormonais. Objetivo: Caracterizar in vitro a resistência ao IGF-1 de pacientes com defeitos no IGF1R, identificados em nosso ambulatório. Material e métodos: Desenvolvemos cultura de fibroblastos de 2 controles (C1 e C2) e de 4 pacientes nascidos PIG (SGA1, SGA2, SGA3 e SGA4) com suspeita de insensibilidade ao IGF-1 por ausência de recuperação do crescimento na vida pós natal. Destes pacientes, um paciente (SGA1) era portador de mutação missense em heterozigose no gene IGF1R (p.Arg511Trp) e os demais apresentavam baixa expressão dos IGF1R em leucócitos periféricos quando avaliados por PCR em tempo real. Um destes pacientes (SGA2) apresentava também a variante alélica p.Gly6Arg do IGF1R em heterozigose, alteração esta encontrada também em controles e familiares sem déficit de crescimento. As ações do IGF-1 foram determinadas por ensaios de proliferação, análise da expressão do IGF-1R e estudos de fosforilação de proteínas da via de sinalização do IGF-1 em fibroblastos (via PI3K). Resultados: As linhagens SGA1, SGA2, SGA3 e SGA4 proliferaram respectivamente 55%, 66%, 64% e 28% a menos sob estímulo de IGF-1 em relação ás linhagens controles. No estudo da expressão do RNAm do IGF1R por PCR em tempo real, foi observada redução na expressão do IGF1R nas linhagens SGA2, SGA3 e SGA4 em relação aos controles, assim como o conteúdo total da proteína IGF-1R. Por outro lado, a linhagem SGA1 mostrou expressão aumentada do IGF1R e no conteúdo da proteína em relação aos controles. Em relação á ativação da via PI3K, todas as linhagens dos pacientes apresentaram menor fosforilação de AKT após estímulo com IGF-1, quando comparadas com as linhagens controles. Conclusão: Demonstramos a presença de insensibilidade parcial ao IGF-1 nas linhagens estudadas. A baixa expressão do IGF1R observada em leucócitos periféricos nas linhagens SGA2, SGA3 e SGA4 foi confirmada em fibroblastos tanto em nível de RNAm quanto da sua proteína. Nestas linhagens a insensibilidade ao IGF-1 é secundária a diminuição da expressão deste receptor. Em contraste a na linhagem com a mutação p.Arg511Trp (SGA1) observou-se expressão normal do IGF-1R na superfície celular. Pacientes com alterações no gene IGF1R não apresentam um fenótipo característico que os diferencie de outras crianças nascidas PIG sem alterações neste gene, mostrando a importância dos estudos moleculares neste grupo de pacientes / Small for gestational age (SGA) children are at a greater risk of having a short stature in adulthood. The type 1 and 2 insulin-like growth factors (IGF-1 and IGF-2) are the main endocrine factors determining fetal growth, and most of the known actions of these hormones are mediated via a receptor tyrosine kinase, IGF-1R. Inactivating mutations and deletions of the IGF1R gene in heterozygosis have been reported with increasing frequency in the last 9 years in patients with a history of a failure to thrive pre- and postnatally. It is postulated that at least 2-3% of the children born SGA could be defective for the IGF1R. The clinical presentation of these patients is highly variable with regard to the severity of growth retardation and pre- and post-natal hormonal parameters. Objectives: The goal of this study was to identify the in vitro insensitivity to IGF-1 in patients with defects in IGF1R. Methods: We developed fibroblast cultures from two controls (C1 and C2) and 4 patients born SGA (SGA1, SGA2, SGA3 and SGA4) with a suspected insensitivity to IGF-1 by the absence of catch-up growth during their postnatal life. Of these patients, one (SGA1) carried a heterozygous missense mutation in the IGF1R gene (p.Arg511Trp), and the others exhibited low expression levels of IGF1R in their peripheral leukocytes, as evaluated using real-time PCR. One of these patients (SGA2) was also heterozygous for the allelic variant p.Gly6Arg of IGF1R, an alteration also found in the controls and family members not displaying growth restriction. The actions of IGF-1 were determined using proliferation assays, an analysis of the expression of IGF- 1R and phosphorylation studies of proteins of the IGF-1 signaling pathway in fibroblasts (via PI3K).Results: The SGA1, SGA2, SGA3 and SGA4 fibroblasts proliferated 55%, 66%, 64% and 28%, respectively, less under the stimulation of IGF-1 compared to the control lines. Using real-time PCR, the IGF1R mRNA expression showed reduced levels of IGF1R in the SGA2, SGA3 and SGA4 cells compared to the controls, and the total IGF-1R protein was also decreased in these cells. Moreover, the SGA1 cells showed increased expression levels of IGF1R mRNA and protein compared to the controls. In relation to the activation of PI3K, all of the cells showed decreased phosphorylation of AKT after the stimulation with IGF-1 compared to the control cells. Conclusion: We demonstrated the presence of a partial insensitivity to IGF-1 in the studied samples. The low expression of IGF1R observed in the peripheral leukocytes in the SGA2, SGA3 and SGA4 fibroblasts was confirmed at both the mRNA and protein levels, and the Andréa de Castro Leal Doutorado insensitivity of the cells to IGF-1 is secondary to the decreased expression of the receptor. In contrast, the cells with the mutation p.Arg511Trp (SGA1) displayed normal IGF-1R expression on the cell surface. The patients with alterations in the IGF1R gene do not exhibit a characteristic phenotype that differentiates them from other children born SGA and with no changes in this gene, thus showing the importance of molecular studies for this group of patients
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Evaluation des facteurs issus de l'efferocytose comme médicament innovant dans le traitement des maladies inflammatoires chroniques de l'intestin / Evaluation of new complex medical biological drug based on apoptotic cell efferocytosis proresolutive factors in the treatment of inflammatory bowel diseases

Martin-Rodriguez, Omayra 10 November 2017 (has links)
La clairance des cellules apoptotiques par les macrophages est à l’origine d’un microenvironnement pro-résolutif composé de différents facteurs solubles, permettant de stopper la réaction inflammatoire et d’engager la réparation tissulaire. La résolution de l’inflammation est parfois défaillante et concourt au développement de pathologies inflammatoires chroniques, comme les maladies inflammatoires chroniques de l’intestin (MICI), qui regroupent la maladie de Crohn (MC) et la rectocolite hémorragique (RCH). Dans ce contexte, nous proposons d’évaluer l’efficacité thérapeutique de l’injection de ces facteurs pro-résolutifs dans le traitement des MICI. Ce produit issu de la culture de macrophages avec des cellules apoptotiques, appelé SuperMApo (Supernatant issued from Macrophage Apoptotic cell culture) (Brevet # WO2014106666-A1, 2013) contient des facteurs pro-résolutifs semblables à ce qu’on retrouve dans le processus physiologique de résolution de l’inflammation, et qui peuvent être absents ou inefficaces chez ces patients.Lors de ce travail, nous avons mise en évidence une efficacité thérapeutique de SuperMApo à l’aide de deux modèles expérimentaux de colite. Pour évaluer la pertinence de ces modèles par rapport à la pratique clinique, nous avons mise en place la vidéo-endoscopie souple. On a montré que l’efficacité de SuperMApo se traduit par diminution du score clinique, endoscopique et histologique des souris colitiques, accompagnée d’une amélioration de la perméabilité intestinale, et de la cicatrisation muqueuse. Cette efficacité thérapeutique est liée en partie à une reprogrammation des cellules présentatrices d’antigènes (APC) notamment de cDC et de macrophages qui présentent moins de réponse aux ligands de TLR, favorisent l’induction de Treg et inhibent la production de Th1. Par ailleurs, SuperMApo induit une cicatrisation nette de la muqueuse intestinale associée à la fois à une activation des myofibroblastes (la forme active des fibroblastes) et des cellules intestinales épithéliales (IEC). Concrètement, SuperMApo augmente les propriétés de migration, de prolifération et de cicatrisation de ces deux types cellulaire. Cet effet dépend en partie des facteurs de croissance au sein de SuperMApo comme le TGF-β, l’IGF-I et le VEGF. Finalement des résultats préliminaires montrent que SuperMApo induit un profil réparateur sur des fibroblastes issus de patients atteints de MICI. L’ensemble de ces résultats montrent, que l’injection de ces facteurs pro-résolutifs permet de mettre en œuvre des mécanismes capables de mettre en place un processus de résolution de l’inflammation et ouvre vers une utilisation clinique de cette approche dans le traitement de MICI. / Inflammation is a natural body defence reaction in response to injuries. The clearance of apoptotic cells by macrophages is at the origin of a pro-resolving microenvironment composed of various soluble factors, allow the arrest of the inflammatory response and to initiate tissue repair. The resolution of inflammation is sometimes defective and contributes to the development of chronic inflammatory diseases, such as chronic inflammatory bowel disease (IBD), which include Crohn's disease (CD) and ulcerative colitis (UC). In this context, we propose to evaluate the therapeutic effect of these pro-resolving factors in the treatment of IBD. This factors derived from the culture of macrophages with apoptotic cells, and called SuperMApo (Supernatant issued from Macrophage Apoptotic cell culture) (Patent # WO2014106666-A1, 2013) contains pro-resolving factors similar to those found in the physiological process of inflammatory resolution, and which may be absent or ineffective in these patients.In this work, we have demonstrated the therapeutic effect of SuperMApo using two experimental models of colitis. To assess the relevance of these models to clinical practice, we have implemented flexible video endoscopy. The therapeutic effect of SuperMApo has been shown to decrease the clinical, endoscopic and histological score of colitis mice, accompanied by improved intestinal permeability and mucosal healing in vivo. This therapeutic effect is related in part to reprogramming of antigen presenting cells (APC), in particular cDC and macrophages, which exhibit less response to TLR ligands, promote induction of Treg and inhibit Th1 production. In addition, SuperMApo induces a marked tissue repair of the intestinal mucosa associated with activation of myofibroblasts, the active form of fibroblasts, and the epithelial intestinal cells (IEC). In particular, SuperMApo increases the migration, proliferation and wound healing properties of these two cell types. This effect depends in part on the growth factors contained in SuperMApo such as TGF-β, IGF-I and VEGF. Finally, preliminary results show that SuperMApo induces a repairing state on fibroblasts from patients with IBD. This opens widely the use of SuperMApo as a clinically approach to propose this new therapeutic option to refractory patients suffering from IBD

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