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‣ Uso de células tronco adultas para estudo da etiopatogenia das fissuras lábio palatinas e bioengenharia de tecidos; The Use of Adult Stem Cells to Study the Etiopathogeny of Cleft Lip and Palate and Tissue Engineering

Bueno, Daniela Franco
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 17/04/2007 Português
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886.9025%
As fissuras lábio palatinas (FLP) são as malformações faciais mais comuns presentes ao nascimento e correspondem a cerca de 25% de todos os defeitos congênitos. Sua incidência é alta, de aproximadamente 1/700 nascimentos e varia entre os diferentes grupos étnicos. Elas representam um problema relevante de saúde, pois os portadores necessitam para sua reabilitação estética e funcional de uma equipe multidisciplinar, do nascimento e geralmente, até a vida adulta, o que exige um alto custo econômico. A etiologia das FLP não sindrômicas ainda é controversa na literatura, apesar de existirem esforços mundiais para identificar os fatores que causam esta patologia. Nosso trabalho consistiu do estabelecimento e caracterização de 23 linhagens de células tronco adultas (CTA) obtidas de polpa de dentes decíduos (11 indivíduos, sendo 5 controles, 5 portadores de FLP não sindrômica e 1 portador da síndrome de Van der Woude), do músculo orbicular do lábio (5 indivíduos portadores de FLP), do osso medular (2 indivíduos portadores de FLP) e de gordura de lipoaspiração (5 controles), com o objetivo de utilizá-las para ajudar a elucidar os mecanismos etiológicos de origem genética das fissuras lábio palatinas não sindrômicas; bem como para utilizá-las para bioengenharia dos tecidos alterados nesta patologia...

‣ Análise in vitro da expressão de proteínas da matriz extracelular (MEC) e de metaloproteinases da matriz (MMPs) em células-tronco adultas de polpa dentária humana; Analysis of ECM proteins and MMPs expression in human dental pulp stem cells

Miyagi, Sueli Patricia Harumi
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 16/04/2008 Português
Relevância na Pesquisa
893.25734%
Células-tronco adultas podem ser isoladas de vários tecidos, dentre eles a polpa dentária humana, tecido originado na papila dentária do dente em desenvolvimento. Estas linhagens multipotentes podem ser estudadas sob vários aspectos, como na elucidação da histogênese de tumores. O objetivo deste estudo foi inferir a histogênese do mixoma odontogênico, neoplasia odontogênica benigna, analisando a expressão de proteínas da matriz extracelular (MEC) e de metaloproteinases da matriz (MMPs) em células-tronco adultas de polpa dentária humana. Três linhagens diferentes de células-tronco originadas de polpas dentárias humanas IDPSCs (DL-1, DL-2 e DL4) foram utilizadas. As proteínas analisadas foram as mesmas expressas na neoplasia: vimentina, colágeno tipo I, fibronectina, tenascina, ácido hialurônico e MMPs (MMP-1, MMP-2 e MMP-9). Imunofluorescência e ensaios enzimáticos foram utilizados para analisar a presença de proteínas nas células cultivadas e no meio de cultura condicionado por estas células, respectivamente. Todas as linhagens celulares expressaram a vimentina e nenhuma expressou o ácido hialurônico. A linhagem celular DL-1 expressou todas as outras proteínas da matriz extracelular estudadas, enquanto que na linhagem DL-2 apenas não foi observada a expressão do colágeno tipo I. Fibronectina e tenascina não foram observados na linhagem DL-4. Todas as linhagens expressaram todas as MMPs...

‣ Avaliação da função erétil após a reconstituição do nervo cavernoso com o uso de células tronco de medula-óssea: estudo experimental em ratos; Cavernous nerve reconstitution with the use of bone marrow stem cells and erectile function evaluation: an animal experimental study

Kaufmann, Oskar Grau
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 07/11/2008 Português
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Introdução: Atualmente a prostatectomia radical retropúbica tem sido responsável por grande parte dos casos de disfunção erétil de causa neurogênica. O desenvolvimento de técnicas como a cirurgia com preservação do feixe vásculo-nervoso, eletro-estimulação intra-operatória o uso de enxertos autólogos para se reestabelecer a comunicação dos nervos cavernosos têm minimizado o grau de lesão neuronal. Entretanto, faz-se necessária a criação de novos métodos de restauração do nervo cavernoso. Neste estudo, investigaremos o uso e a aplicação de células tronco adultas de medula óssea de ratos e sua capacidade para regeneração do nervo cavernosos lesado e para restauração da função erétil em ratos. Objetivo: Avaliar a influência de células tronco adultas da medula óssea de ratos na regeneração do nervo cavernosos lesado, tomando-se como parâmetro o retorno da função erétil nos animais submetidos ao teste de ereção induzido pela apomorfina. Material e Método: Quarenta e oito ratos Wistar-EPM machos, com idades entre 9 e 10 semanas, pesando aproximadamente 250 gramas foram usados e randomicamente subdivididos em quatro grupos de estudo contendo 12 animais cada. Os grupos experimentais foram divididos em: Grupo I: exposição cirúrgica bilateral nervo cavernoso sem lesão do mesmo.Grupo II: lesão cirúrgica bilateral do nervo cavernoso de aproximadamente 3 mm...

‣ 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
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 23/03/2015 Português
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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...

‣ Células-Tronco; Stem cells

Cirne Lima, Elizabeth Obino
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
Português
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Considerando a origem de obtenção, as células-tronco podem ser classificadas como células-tronco embrionárias (ES) ou como células-tronco adultas. Mas, se a plasticidade for considerada, as células-tronco podem ser classificadas como células totipotentes, quando as células-tronco preservam a capacidade de dar origem a um novo indivíduo completo. Quando as células-tronco perdem esta capacidade, passam a ser classificadas como células-tronco pluripotentes, que podem dar origem a praticamente todos os tipos celulares maduros que compõem um organismo. Células-tronco totipotentes e pluripotentes podem ser obtidas de estágios embrionários iniciais. O grupo de células-tronco que apresenta plasticidade restrita é denominado de multipotente. Estas células podem se diferenciar em determinado tipo celular comprometido com um órgão ou tecido específico. Células ES podem ser expandidas in vitro, mantendo sua forma indiferenciada, ou podem ser submetidas a uma série de protocolos, que irão induzir diferenciação in vitro. Por outro lado, as células-tronco adultas multipotentes não podem ser mantidas in vitro na forma indiferenciada, exceto uma subpopulação de célulastronco adultas aderentes, denominadas células-tronco mesenquimais...

‣ Adult stem cells in bone and cartilage tissue engineering

Salgado, A. J.; Oliveira, João T.; Pedro, A. J.; Reis, R. L.
Fonte: Bentham Science Publishers Publicador: Bentham Science Publishers
Tipo: Artigo de Revista Científica
Publicado em //2006 Português
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The progressive increase in lif€ expectancy within the last century has led to the appearance of novel health related problems, some of those within the musculoskeletal Íield. Among the latter, one can find diseases such as osteoporosis, rheumatoid arthritis and bone cancer, just to mention some of the most relevant. Other related problems are those that arise from serious injuries, often leading to non-recoverable critical size defects. The therapies currently used to treat this type of diseases/injuries are based on the use of pharmaceutical agents, auto/allotransplant and synthetic materials. However, such solutions present a number of inconveniences and therefore, there is â constant search for novel therapeutic solutions. The appearance of a novel field of science called Tissue engileering brought some hope for the solution of the above mentioned problems. In this field, it is believed that by combining a 3D porous template - scaffold - with an adequate cell population, with osteo or chondrogenic potential, it will be possible to develop bone and cartilage tissue €quivalents that when implanted lr? vivo, could lead to the total regeneration of the affected area. This ideal cell population should have a series of properties...

‣ Autologous Transplantation of Bone Marrow Adult Stem Cells for the Treatment of Idiopathic Dilated Cardiomyopathy

Westphal,Ricardo João; Bueno,Ronaldo Rocha Loures; Galvão,Paulo Bezerra de Araújo; Zanis Neto,José; Souza,Juliano Mendes; Guérios,Ênio Eduardo; Senegaglia,Alexandra Cristina; Brofman,Paulo Roberto; Pasquini,Ricardo; Cunha,Claudio Leinig Pereira da
Fonte: Sociedade Brasileira de Cardiologia - SBC Publicador: Sociedade Brasileira de Cardiologia - SBC
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2014 Português
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Background: Morbimortality in patients with dilated idiopathic cardiomyopathy is high, even under optimal medical treatment. Autologous infusion of bone marrow adult stem cells has shown promising preliminary results in these patients. Objective: Determine the effectiveness of autologous transplantation of bone marrow adult stem cells on systolic and diastolic left ventricular function, and on the degree of mitral regurgitation in patients with dilated idiopathic cardiomyopathy in functional classes NYHA II and III. Methods: We administered 4,54 x 108 ± 0,89 x 108 bone marrow adult stem cells into the coronary arteries of 24 patients with dilated idiopathic cardiomyopathy in functional classes NYHA II and III. Changes in functional class, systolic and diastolic left ventricular function and degree of mitral regurgitation were assessed after 3 months, 6 months and 1 year. Results: During follow-up, six patients (25%) improved functional class and eight (33.3%) kept stable. Left ventricular ejection fraction improved 8.9%, 9.7% e 13.6%, after 3, 6 and 12 months (p = 0.024; 0.017 and 0.018), respectively. There were no significant changes neither in diastolic left ventricular function nor in mitral regurgitation degree. A combined cardiac resynchronization and implantable cardioversion defibrillation was implanted in two patients (8.3%). Four patients (16.6%) had sudden death and four patients died due to terminal cardiac failure. Average survival of these eight patients was 2.6 years. Conclusion: Intracoronary infusion of bone marrow adult stem cells was associated with an improvement or stabilization of functional class and an improvement in left ventricular ejection fraction...

‣ In Vitro Differentiation of Embryonic and Adult Stem Cells into Hepatocytes: State of the Art

Snykers, Sarah; De Kock, Joery; Rogiers, Vera; Vanhaecke, Tamara
Fonte: Wiley Subscription Services, Inc., A Wiley Company Publicador: Wiley Subscription Services, Inc., A Wiley Company
Tipo: Artigo de Revista Científica
Publicado em /03/2009 Português
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Stem cells are a unique source of self-renewing cells within the human body. Before the end of the last millennium, adult stem cells, in contrast to their embryonic counterparts, were considered to be lineage-restricted cells or incapable of crossing lineage boundaries. However, the unique breakthrough of muscle and liver regeneration by adult bone marrow stem cells at the end of the 1990s ended this long-standing paradigm. Since then, the number of articles reporting the existence of multipotent stem cells in skin, neuronal tissue, adipose tissue, and bone marrow has escalated, giving rise, both in vivo and in vitro, to cell types other than their tissue of origin. The phenomenon of fate reprogrammation and phenotypic diversification remains, though, an enigmatic and rare process. Understanding how to control both proliferation and differentiation of stem cells and their progeny is a challenge in many fields, going from preclinical drug discovery and development to clinical therapy. In this review, we focus on current strategies to differentiate embryonic, mesenchymal(-like), and liver stem/progenitor cells into hepatocytes in vitro. Special attention is paid to intracellular and extracellular signaling, genetic modification, and cell-cell and cell-matrix interactions. In addition...

‣ Corneal Limbal Microenvironment Can Induce Transdifferentiation of Hair Follicle Stem Cells into Corneal Epithelial-like Cells

Blazejewska, Ewa Anna; Schlötzer-Schrehardt, Ursula; Zenkel, Matthias; Bachmann, Björn; Chankiewitz, Erik; Jacobi, Christina; Kruse, Friedrich E
Fonte: Wiley Subscription Services, Inc., A Wiley Company Publicador: Wiley Subscription Services, Inc., A Wiley Company
Tipo: Artigo de Revista Científica
Publicado em /03/2009 Português
Relevância na Pesquisa
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The aim of this study was to investigate the transdifferentiation potential of murine vibrissa hair follicle (HF) stem cells into corneal epithelial-like cells through modulation by corneal- or limbus-specific microenvironmental factors. Adult epithelial stem cells were isolated from the HF bulge region by mechanical dissection or fluorescence-activated cell sorting using antibodies to α6 integrin, enriched by clonal expansion, and subcultivated on various extracellular matrices (type IV collagen, laminin-1, laminin-5, fibronectin) and in different conditioned media derived from central and peripheral corneal fibroblasts, limbal stromal fibroblasts, and 3T3 fibroblasts. Cellular phenotype and differentiation were evaluated by light and electron microscopy, real-time reverse transcription-polymerase chain reaction, immunocytochemistry, and Western blotting, using antibodies against putative stem cell markers (K15, α6 integrin) and differentiation markers characteristic for corneal epithelium (K12, Pax6) or epidermis (K10). Using laminin-5, a major component of the corneo-limbal basement membrane zone, and conditioned medium from limbal stromal fibroblasts, clonally enriched HF stem and progenitor cells adhered rapidly and formed regularly arranged stratified cell sheets. Conditioned medium derived from limbal fibroblasts markedly upregulated expression of cornea-specific K12 and Pax6 on the mRNA and protein level...

‣ A planarian p53 homolog regulates proliferation and self-renewal in adult stem cell lineages

Pearson, Bret J.; Alvarado, Alejandro Sánchez
Fonte: Company of Biologists Publicador: Company of Biologists
Tipo: Artigo de Revista Científica
Publicado em 15/01/2010 Português
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The functions of adult stem cells and tumor suppressor genes are known to intersect. However, when and how tumor suppressors function in the lineages produced by adult stem cells is unknown. With a large population of stem cells that can be manipulated and studied in vivo, the freshwater planarian is an ideal system with which to investigate these questions. Here, we focus on the tumor suppressor p53, homologs of which have no known role in stem cell biology in any invertebrate examined thus far. Planaria have a single p53 family member, Smed-p53, which is predominantly expressed in newly made stem cell progeny. When Smed-p53 is targeted by RNAi, the stem cell population increases at the expense of progeny, resulting in hyper-proliferation. However, ultimately the stem cell population fails to self-renew. Our results suggest that prior to the vertebrates, an ancestral p53-like molecule already had functions in stem cell proliferation control and self-renewal.

‣ Clonal analyses reveal roles of organ founding stem cells, melanocyte stem cells and melanoblasts in establishment, growth and regeneration of the adult zebrafish fin

Tu, Shu; Johnson, Stephen L.
Fonte: Company of Biologists Publicador: Company of Biologists
Tipo: Artigo de Revista Científica
Publicado em 01/12/2010 Português
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801.2875%
In vertebrates, the adult form emerges from the embryo by mobilization of precursors or adult stem cells. What different cell types these precursors give rise to, how many precursors establish the tissue or organ, and how they divide to establish and maintain the adult form remain largely unknown. We use the pigment pattern of the adult zebrafish fin, with a variety of clonal and lineage analyses, to address these issues. Early embryonic labeling with lineage-marker-bearing transposons shows that all classes of fin melanocytes (ontogenetic, regeneration and kit-independent melanocytes) and xanthophores arise from the same melanocyte-producing founding stem cells (mFSCs), whereas iridophores arise from distinct precursors. Additionally, these experiments show that, on average, six and nine mFSCs colonize the caudal and anal fin primordia, and daughters of different mFSCs always intercalate to form the adult pattern. Labeled clones are arrayed along the proximal-distal axis of the fin, and melanocyte time-of-differentiation lineage assays show that although most of the pigment pattern growth is at the distal edge of the fin, significant growth also occurs proximally. This suggests that leading edge melanocyte stem cells (MSCs) divide both asymmetrically to generate new melanocytes...

‣ Naïve Adult Stem Cells Isolation from Primary Human Fibroblast Cultures

Wenzel, Vera; Roedl, Daniela; Ring, Johannes; Djabali, Karima
Fonte: MyJove Corporation Publicador: MyJove Corporation
Tipo: Artigo de Revista Científica
Publicado em 03/05/2013 Português
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Over the last decade, several adult stem cell populations have been identified in human skin 1-4. The isolation of multipotent adult dermal precursors was first reported by Miller F. D laboratory 5, 6. These early studies described a multipotent precursor cell population from adult mammalian dermis 5. These cells--termed SKPs, for skin-derived precursors-- were isolated and expanded from rodent and human skin and differentiated into both neural and mesodermal progeny, including cell types never found in skin, such as neurons 5. Immunocytochemical studies on cultured SKPs revealed that cells expressed vimentin and nestin, an intermediate filament protein expressed in neural and skeletal muscle precursors, in addition to fibronectin and multipotent stem cell markers 6. Until now, the adult stem cells population SKPs have been isolated from freshly collected mammalian skin biopsies.

‣ Microcarrier-Based Expansion of Adult Murine Side Population Stem Cells

Pacak, Christina Ann; Eddy, Mau-Thek; Woodhull, Lindsey; Wang, Kai-Roy; Alpatov, Ivan; Fullen, Shelby; Dowd, Rory P.; Choi, Yeong-Hoon; Cowan, Douglas Burr
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Português
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The lack of reliable methods to efficiently isolate and propagate stem cell populations is a significant obstacle to the advancement of cell-based therapies for human diseases. One isolation technique is based on efflux of the fluorophore Hoechst 33342. Using fluorescence-activated cell sorting (FACS), a sub-population containing adult stem cells has been identified in a multitude of tissues in every mammalian species examined. These rare cells are referred to as the ‘side population’ or SP due to a distinctive FACS profile that results from weak staining by Hoechst dye. Although the SP contains multi-potent cells capable of differentiating toward hematopoietic and mesenchymal lineages; there is currently no method to efficiently expand them. Here, we describe a spinner-flask culture system containing C2C12 myoblasts attached to spherical microcarriers that act to support the growth of non-adherent, post-natal murine skeletal muscle and bone marrow SP cells. Using FACS and hemocytometry, we show expansion of unfractionated EGFP+ SP cells over 6 wks. A significant number of these cells retain characteristics of freshly-isolated, unfractionated SP cells with respect to protein expression and dye efflux capacity. Expansion of the SP will permit further study of these heterogeneous cells and determine their therapeutic potential for regenerative and reparative therapies.

‣ Wnts Enhance Neurotrophin-Induced Neuronal Differentiation in Adult Bone-Marrow-Derived Mesenchymal Stem Cells via Canonical and Noncanonical Signaling Pathways

Tsai, Hung-Li; Deng, Wing-Ping; Lai, Wen-Fu Thomas; Chiu, Wen-Ta; Yang, Charn-Bing; Tsai, Yu-Hui; Hwang, Shiaw-Min; Renshaw, Perry F.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Português
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Wnts were previously shown to regulate the neurogenesis of neural stem or progenitor cells. Here, we explored the underlying molecular mechanisms through which Wnt signaling regulates neurotrophins (NTs) in the NT-induced neuronal differentiation of human mesenchymal stem cells (hMSCs). NTs can increase the expression of Wnt1 and Wnt7a in hMSCs. However, only Wnt7a enables the expression of synapsin-1, a synaptic marker in mature neurons, to be induced and triggers the formation of cholinergic and dopaminergic neurons. Human recombinant (hr)Wnt7a and general neuron makers were positively correlated in a dose- and time-dependent manner. In addition, the expression of synaptic markers and neurites was induced by Wnt7a and lithium, a glycogen synthase kinase-3β inhibitor, in the NT-induced hMSCs via the canonical/β-catenin pathway, but was inhibited by Wnt inhibitors and frizzled-5 (Frz5) blocking antibodies. In addition, hrWnt7a triggered the formation of cholinergic and dopaminergic neurons via the non-canonical/c-jun N-terminal kinase (JNK) pathway, and the formation of these neurons was inhibited by a JNK inhibitor and Frz9 blocking antibodies. In conclusion, hrWnt7a enhances the synthesis of synapse and facilitates neuronal differentiation in hMSCS through various Frz receptors. These mechanisms may be employed widely in the transdifferentiation of other adult stem cells.

‣ Adult human dental pulp stem cells differentiate toward functionally active neurons under appropriate environmental cues

Arthur, A.; Rychkov, G.; Shi, S.; Koblar, S.; Gronthos, S.
Fonte: Alphamed Press Publicador: Alphamed Press
Tipo: Artigo de Revista Científica
Publicado em //2008 Português
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Human adult dental pulp stem cells (DPSCs) reside within the perivascular niche of dental pulp and are thought to originate from migrating cranial neural crest (CNC) cells. During embryonic development, CNC cells differentiate into a wide variety of cell types, including neurons of the peripheral nervous system. Previously, we have demonstrated that DPSCs derived from adult human third molar teeth differentiate into cell types reminiscent of CNC embryonic ontology. We hypothesized that DPSCs exposed to the appropriate environmental cues would differentiate into functionally active neurons. The data demonstrated that ex vivo-expanded human adult DPSCs responded to neuronal inductive conditions both in vitro and in vivo. Human adult DPSCs, but not human foreskin fibroblasts (HFFs), acquired a neuronal morphology, and expressed neuronal-specific markers at both the gene and protein levels. Culture-expanded DPSCs also exhibited the capacity to produce a sodium current consistent with functional neuronal cells when exposed to neuronal inductive media. Furthermore, the response of human DPSCs and HFFs to endogenous neuronal environmental cues was determined in vivo using an avian xenotransplantation assay. DPSCs expressed neuronal markers and acquired a neuronal morphology following transplantation into the mesencephalon of embryonic day-2 chicken embryo...

‣ Expression Profile of microRNAs Regulating Proliferation and Differentiation in Mouse Adult Cardiac Stem Cells

Brás-Rosário, Luis; Matsuda, Alex; Pinheiro, Ana Isabel; Gardner, Rui; Lopes, Telma; Amaral, Andreia; Gama-Carvalho, Margarida
Fonte: PLOS Publicador: PLOS
Tipo: Artigo de Revista Científica
Publicado em 17/05/2013 Português
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The identification of cardiac cells with stem cell properties changed the paradigm of the heart as a post mitotic organ. These cells proliferate and differentiate into cardiomyocytes, endothelial and vascular smooth muscle cells, providing for cardiac cell homeostasis and regeneration. microRNAs are master switches controlling proliferation and differentiation, in particular regulating stem cell biology and cardiac development. Modulation of microRNAs -regulated gene expression networks holds the potential to control cell fate and proliferation, with predictable biotechnologic and therapeutic applications. To obtain insights into the regulatory networks active in cardiac stem cells, we characterized the expression profile of 95 microRNAs with reported functions in stem cell and tissue differentiation in mouse cardiac stem cells, and compared it to that of mouse embryonic heart and mesenchymal stem cells. The most highly expressed microRNAs identified in cardiac stem cells are known to target key genes involved in the control of cell proliferation and adhesion, vascular function and cardiomyocyte differentiation. We report a subset of differentially expressed microRNAs that are proposed to act as regulators of differentiation and proliferation of adult cardiac stem cells...

‣ A importância do uso das células tronco para a saúde pública; The importance of the use of stem cells for public health

PEREIRA, Lygia da Veiga
Fonte: Associação Brasileira de Pós-Graduação em Saúde Coletiva Publicador: Associação Brasileira de Pós-Graduação em Saúde Coletiva
Tipo: Artigo de Revista Científica
Português
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Em 1999, as células-tronco foram eleitas "Scientific Breakthrough of the Year" (avanço científico do ano) pela revista Science¹. Naquele ano, foi demonstrado que células-tronco de tecidos adultos mantinham a capacidade de se diferenciar em outros tipos de tecidos. No ano anterior, as primeiras linhagens de células-tronco embrionárias humanas foram estabelecidas. Desde então, o número de artigos científicos sobre células-tronco vem crescendo exponencialmente, onde novos paradigmas são estabelecidos. Neste artigo, farei uma revisão da área de células-tronco com um foco especial em seu uso como agente terapêutico em doenças comuns como diabetes e cardiopatias. As células-tronco serão tratadas em dois grupos distintos: as embrionárias e as adultas. Enquanto o potencial de diferenciação das primeiras está bem caracterizado em camundongos e em humanos, seu uso em terapia celular e em pesquisa tem sido dificultado por questões de histocompatibilidade, segurança e ética. Em contraste, células-tronco adultas não apresentam estes empecilhos, apesar da extensão de sua plasticidade ainda estar sob investigação. Mesmo assim, diversos testes clínicos em humanos estão em andamento utilizando células-tronco adultas...

‣ Adipose tissue mature stem cells in skin healing: a controlled randomized study

Martins,Pedro Djacir Escobar; Uebel,Carlos Oscar; Machado,Denise Cantarelli; Silva,Jefferson Braga da
Fonte: Sociedade Brasileira de Cirurgia Plástica Publicador: Sociedade Brasileira de Cirurgia Plástica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2011 Português
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BACKGROUND: The differences between fetal and adult scars suggest the possibility of manipulating skin scarring outcomes. This study aimed to assess whether the use of adult stem cells from adipose tissue is beneficial to skin healing. METHODS: This was a randomized controlled study for which 18 patients were selected based on inclusion and exclusion criteria. The adult stem cells used were autologous and were extracted from infraumbilical adipose tissue prior to abdominoplasty. These cells were implanted into the surgical wound dermis in the suprapubic region before skin synthesis. The results were assessed blindly based on the Draaijers scale by three physicians and by the patients themselves in a self-assessment. Photometric assessment by digital photography was also performed. RESULTS: Among the 18 operated patients, considering the surgical result, 17 (94.4%) had excellent or good results and one (5.5%) had wound dehiscence, which was considered a bad result. Considering skin healing in the searched area, there was no statistically significant difference in the photometric evaluation; in both the self-assessment by the patients and the physicians' assessment, the results were significantly in favor of intervention with stem cells (P = 0.12 and P = 0.003...

‣ Genetically induced cell death in bulge stem cells reveals their redundancy for hair and epidermal regeneration

Driskell, Iwona; Oeztuerk-Winder, Feride; Humphreys, Peter; Frye, Michaela
Fonte: Wiley on behalf of AlphaMed Press Publicador: Wiley on behalf of AlphaMed Press
Tipo: Article; published version
Português
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This is the final version. It was first published by Wiley at http://onlinelibrary.wiley.com/doi/10.1002/stem.1910/abstract.; Adult mammalian epidermis contains multiple stem cell populations in which quiescent and more proliferative stem and progenitor populations co-exist. However, the precise interrelation of these populations in homeostasis remains unclear. Here, we blocked the contribution of quiescent keratin 19 (K19)-expressing bulge stem cells to hair follicle formation through genetic ablation of the essential histone methyltransferase Setd8 that is required for the maintenance of adult skin. Deletion of Setd8 eliminated the contribution of bulge cells to hair follicle regeneration through inhibition of cell division and induction of cell death, but the growth and morphology of hair follicles were unaffected. Furthermore, ablation of Setd8 in the hair follicle bulge blocked the contribution of K19-postive stem cells to wounded epidermis, but the wound healing process was unaltered. Our data indicate that quiescent bulge stem cells are dispensable for hair follicle regeneration and epidermal injury in the short term and support the hypothesis that quiescent and cycling stem cell populations are equipotent.; This work was funded by Cancer Research UK (CR-UK; C10701/A15181) and the British Skin Foundation (BSF; 5010). Special thanks go to the mouse/transgenic and histology facilities at WT-MRC-Stem Cell Institute.

‣ Comparative study of bone regeneration in critical cranial bone defects using bone marrow adult stem cells and calcium phosphate

Allais,Marvis; Maurette,Paul E.; Gomes de Morais,Natália; Barreto da Costa,Thacianna; Fraga,Simone; Dias de Oliveira e Silva,Emanuel; Rodrigues Laureano Filho,Jose; Barbosa de Castro,Celia Maria
Fonte: Revista Española de Cirugía Oral y Maxilofacial Publicador: Revista Española de Cirugía Oral y Maxilofacial
Tipo: info:eu-repo/semantics/article; journal article; info:eu-repo/semantics/publishedVersion Formato: text/html; application/pdf
Publicado em 01/03/2015 Português
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Objective: To compare the use of Bone Marrow adult Stem Cells (BMSCs), differentiated in vitro into osteoblasts, associated to calcium phosphate versus autogenous bone graft, in the repair process of critical size bone defects. Materials and method: On 36 Wistar adult rats, bilateral full-thickness defects on parietal bone were created. The defects were either repaired with calcium phosphate (group I), calcium phosphate + (BMSCs) (group II) or autogenous bone graft (group III), and the opposite side with blood clot (Control Group). In all cases a collagen membrane was used. The animals were sacrificed at 30 and 60 days, and all specimens were collected for further histological and histomorfometric study. Results: At 30 days, group III (autogenous bone graft) evidences a statistical difference on bone formation when compared to the experimental and control groups (p ≤ 0.05). At 60 days group II (BS + BMSCs) and group III (autogenous bone) showed a similar bone formation and has only a statistical difference when compared to group I (BS) and control group. Conclusion: The use of calcium phosphate in conjunction with BMSCs resulted in a similar behavior in the process of bone repair in critical size defects, when compared with autogenous bone graft.