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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.
1

Energieffektivisering av arbetsbodar på byggarbetsplatser / Improvement of the energy efficiency of building shed establishments

Olsson, Andreas January 2012 (has links)
Everyone has to take a greater responsibility in energy issues, both individuals and companies. There have been some major developments in the construction industry but there is still a lot to be done.   This diploma work thesis presents different methods of making existing construction shed establishments to use less energy. What is possible to do and how much energy is there to be saved? A shed establishment consisting of 8 shed units were studied in this project and the building simulation tool VIP-Energy was used to simulate different types of material in the sheds. An infrared camera was used to locate thermal bridges.   There are several factors that can be improved to make a construction shed establishment to use less energy. Replacement of old windows and doors, using more insulation, replacement of old less efficient insulation with new improved materials, using a different heating system, and more. One factor, which is more important than all the others, is to insulate between the 8 different shed units in the establishment. It is also important to make the construction wind proof.   The results show that if you replace the old wall and roof insulation with new better insulation, replace the old windows and doors and seal the gaps between the shed units the total energy reduction would be as high as 60%. All companies working with the handling or utilization of shed establishments at building sites should consider these improvements.
2

Reparo de lesões induzidas na articulação femorotibiopatelar de ovinos através do implante de biomateriais associados à células-tronco de polpa dentária humana / Repair of induced lesion in femorotibiopatelar's joints in sheep through use biomaterial associated with human dental pulp stem cell

Silva, Marcos Vinícius Mendes 18 August 2015 (has links)
Lesões na cartilagem articular do joelho são patologias frequentes e geralmente causadas por traumas. Apesar de algumas serem assintomáticas, essas alterações osteocondrais podem evoluir para degeneração da cartilagem articular e osteoartrose. Uma da degeneração progressiva da cartilagem articular leva a osteoartrite (OA), comumente sendo a articulação femorotibiopatelar a mais afetada. Como os tratamentos convencionais para OA não são curativos, apenas paliativos, a terapia celular com células-tronco (CT) desponta como alternativa. Neste trabalho utilizamos células-tronco de dente decíduo esfoliado (Stem cells from Human Exfoliated Deciduous teeth - SHED), cultivadas em associação com um biomaterial, para tratar lesões osteocondrais provocadas em joelhos de ovinos. Quatro defeitos osteocondrais foram cirurgicamente produzidos para testar quatro condições: 1) SHED associada ao biomaterial, 2) somente biomaterial, 3) somente SHED e 4) nenhum tratamento (controle). Os ovinos foram acompanhados clinicamente e através de exames radiográfico, US e artroscopia, por 120, 190, 365 e 730 dias até a eutanásia. Os resultados revelaram que o tratamento com biomaterial em associação com SHED, produziu reparo similar à estrutura cartilagínea a partir de 190 dias, apresentando características de cartilagem adjacente. Entretanto, apesar dos resultados positivos em relação ao reparo da lesão osteocondral, não foi possível afirmar se a melhora deveu-se a diferenciação direta das SHED para células presentes na cartilagem ou se foi um efeito parácrino das mesmas. Em tempo, não foi observada rejeição e nenhuma reação adversa ao implante celular xenogênico durante o período experimental. / Articular cartilage injuries on the knee are frequent pathologies and usually caused by trauma. Although some are asymptomatic, these changes may evolve into osteochondral articular cartilage degeneration and osteoarthritis. A progressive degeneration of articular cartilage leads to osteoarthritis (OA), being femorotibiopatelar joint the most affected one. As conventional treatments for OA are not curative, but palliative, cell therapy with stem cells (SC) stands out as an alternative. In this work we used stem cells from human exfoliated deciduous teeth (SHED), grown in association with a biomaterial, to treat osteochondral lesions on sheep\'s knees. Four osteochondral defects were surgically produced to test four conditions: 1) SHED associated with the biomaterial, 2) only the biomaterial, 3) only SHED and 4) no treatment (control). The sheep were followed clinically and through radiographic exams, US and arthroscopy, for 120, 190, 365 and 730 days until euthanasia. The results showed that treatment with biomaterial in combination with SHED produced repair similar to the cartilage structure from 190 days, showing cartilage adjacent features. However, despite the positive results in relation to the repair of osteochondral lesion it was not possible to say whether the improvement was due to direct differentiation of SHED for cells present in cartilage or was a paracrine effect. In time, there was no rejection and no adverse reaction to the xenogenic cell implant during the trial period.
3

Diferenciação neuronal de células-tronco de dente decíduo esfoliado / Stem cell from human expholiated deciduous teeth neuronal differentiation

Cruz, Raphael Marques de Almeida Rosa da 29 September 2016 (has links)
As células-tronco (CT) são células que apresentam propriedades de auto-renovação, capazes de gerar diferentes tipos celulares e reconstituir diversos tipos de tecidos, por isso têm sido vistas como uma alternativa terapêutica para o tratamento de muitas doenças cujo tratamento convencional não é eficiente. Além disso, por sua plasticidade, as CT podem ser usadas para produzir modelos in vitro para o estudo de doenças, o que tem sido particularmente interessante para doenças que acometem o sistema nervoso. As células-tronco humanas de dente decíduo esfoliado (Stem cell from Human Esfoliated Deciduous teeth, SHED) são descritas em alguns trabalhos como capazes de se diferenciarem em células neuronais através da transdiferenciação direta, um processo simples que possibilita a diferenciação de um tipo celular em outro por meio da utilização de agentes químicos. No entanto, a diferenciação de SHED em neurônios é contestada como sendo um artefato de cultura devido ação citotóxica destes agentes. Com base nesta premissa, o objetivo deste trabalho foi realizar protocolos para a produção de neurônios a partir das SHED utilizando modificações de métodos descritos na literatura e utilizados na diferenciação neuronal. Durante um dos protocolos utilizados, foi possível verificar a morfologia de células semelhantes à neurônio, porém após alguns dias de manutenção, as células voltavam ao formato fusiforme original. Com este trabalho podemos afirmar que, de acordo com os resultados obtidos, as SHED não geram neurônios funcionais / Stem cells (SC) are cells that present self-renewal properties, capable of generating cells types and reconstitute several tissue types. For this reason, they have been seen as a therapeutic alternative to the treatment of many diseases which conventional treatment is not efficient. Besides, because of its plasticity, SC may be used to produce in vitro models in order to study diseases, what is interesting to diseases that affect the nervous system. Human SC from SHED (Stem cell from Human Exfoliated Deciduous teeth, SHED) are described in some papers as being capable of self-differentiation in neuronal cells through the direct transdifferentiation, a simple process that makes possible the differentiation of a cell type in another through the use of chemical agents. Nevertheless, SHED differentiation is refuted as being a artifact of culture due to cytotoxic action of these agents. Based on this premise, the aim of this study was to carry out protocols in order to produce neurons from SHED, using modifications and methods of neuronal differentiation described in the literature and used in the neuronal differentiation. During one of the protocols used, it was possible to verify the morphology of the cells as neuron-like, however, after some days of maintenance, they turn back to their original fusiform format. In this study, we can state, according to the obtained results, that SHED do not generate functional neurons
4

Diferenciação neuronal de células-tronco de dente decíduo esfoliado / Stem cell from human expholiated deciduous teeth neuronal differentiation

Raphael Marques de Almeida Rosa da Cruz 29 September 2016 (has links)
As células-tronco (CT) são células que apresentam propriedades de auto-renovação, capazes de gerar diferentes tipos celulares e reconstituir diversos tipos de tecidos, por isso têm sido vistas como uma alternativa terapêutica para o tratamento de muitas doenças cujo tratamento convencional não é eficiente. Além disso, por sua plasticidade, as CT podem ser usadas para produzir modelos in vitro para o estudo de doenças, o que tem sido particularmente interessante para doenças que acometem o sistema nervoso. As células-tronco humanas de dente decíduo esfoliado (Stem cell from Human Esfoliated Deciduous teeth, SHED) são descritas em alguns trabalhos como capazes de se diferenciarem em células neuronais através da transdiferenciação direta, um processo simples que possibilita a diferenciação de um tipo celular em outro por meio da utilização de agentes químicos. No entanto, a diferenciação de SHED em neurônios é contestada como sendo um artefato de cultura devido ação citotóxica destes agentes. Com base nesta premissa, o objetivo deste trabalho foi realizar protocolos para a produção de neurônios a partir das SHED utilizando modificações de métodos descritos na literatura e utilizados na diferenciação neuronal. Durante um dos protocolos utilizados, foi possível verificar a morfologia de células semelhantes à neurônio, porém após alguns dias de manutenção, as células voltavam ao formato fusiforme original. Com este trabalho podemos afirmar que, de acordo com os resultados obtidos, as SHED não geram neurônios funcionais / Stem cells (SC) are cells that present self-renewal properties, capable of generating cells types and reconstitute several tissue types. For this reason, they have been seen as a therapeutic alternative to the treatment of many diseases which conventional treatment is not efficient. Besides, because of its plasticity, SC may be used to produce in vitro models in order to study diseases, what is interesting to diseases that affect the nervous system. Human SC from SHED (Stem cell from Human Exfoliated Deciduous teeth, SHED) are described in some papers as being capable of self-differentiation in neuronal cells through the direct transdifferentiation, a simple process that makes possible the differentiation of a cell type in another through the use of chemical agents. Nevertheless, SHED differentiation is refuted as being a artifact of culture due to cytotoxic action of these agents. Based on this premise, the aim of this study was to carry out protocols in order to produce neurons from SHED, using modifications and methods of neuronal differentiation described in the literature and used in the neuronal differentiation. During one of the protocols used, it was possible to verify the morphology of the cells as neuron-like, however, after some days of maintenance, they turn back to their original fusiform format. In this study, we can state, according to the obtained results, that SHED do not generate functional neurons
5

Reparo de lesões induzidas na articulação femorotibiopatelar de ovinos através do implante de biomateriais associados à células-tronco de polpa dentária humana / Repair of induced lesion in femorotibiopatelar's joints in sheep through use biomaterial associated with human dental pulp stem cell

Marcos Vinícius Mendes Silva 18 August 2015 (has links)
Lesões na cartilagem articular do joelho são patologias frequentes e geralmente causadas por traumas. Apesar de algumas serem assintomáticas, essas alterações osteocondrais podem evoluir para degeneração da cartilagem articular e osteoartrose. Uma da degeneração progressiva da cartilagem articular leva a osteoartrite (OA), comumente sendo a articulação femorotibiopatelar a mais afetada. Como os tratamentos convencionais para OA não são curativos, apenas paliativos, a terapia celular com células-tronco (CT) desponta como alternativa. Neste trabalho utilizamos células-tronco de dente decíduo esfoliado (Stem cells from Human Exfoliated Deciduous teeth - SHED), cultivadas em associação com um biomaterial, para tratar lesões osteocondrais provocadas em joelhos de ovinos. Quatro defeitos osteocondrais foram cirurgicamente produzidos para testar quatro condições: 1) SHED associada ao biomaterial, 2) somente biomaterial, 3) somente SHED e 4) nenhum tratamento (controle). Os ovinos foram acompanhados clinicamente e através de exames radiográfico, US e artroscopia, por 120, 190, 365 e 730 dias até a eutanásia. Os resultados revelaram que o tratamento com biomaterial em associação com SHED, produziu reparo similar à estrutura cartilagínea a partir de 190 dias, apresentando características de cartilagem adjacente. Entretanto, apesar dos resultados positivos em relação ao reparo da lesão osteocondral, não foi possível afirmar se a melhora deveu-se a diferenciação direta das SHED para células presentes na cartilagem ou se foi um efeito parácrino das mesmas. Em tempo, não foi observada rejeição e nenhuma reação adversa ao implante celular xenogênico durante o período experimental. / Articular cartilage injuries on the knee are frequent pathologies and usually caused by trauma. Although some are asymptomatic, these changes may evolve into osteochondral articular cartilage degeneration and osteoarthritis. A progressive degeneration of articular cartilage leads to osteoarthritis (OA), being femorotibiopatelar joint the most affected one. As conventional treatments for OA are not curative, but palliative, cell therapy with stem cells (SC) stands out as an alternative. In this work we used stem cells from human exfoliated deciduous teeth (SHED), grown in association with a biomaterial, to treat osteochondral lesions on sheep\'s knees. Four osteochondral defects were surgically produced to test four conditions: 1) SHED associated with the biomaterial, 2) only the biomaterial, 3) only SHED and 4) no treatment (control). The sheep were followed clinically and through radiographic exams, US and arthroscopy, for 120, 190, 365 and 730 days until euthanasia. The results showed that treatment with biomaterial in combination with SHED produced repair similar to the cartilage structure from 190 days, showing cartilage adjacent features. However, despite the positive results in relation to the repair of osteochondral lesion it was not possible to say whether the improvement was due to direct differentiation of SHED for cells present in cartilage or was a paracrine effect. In time, there was no rejection and no adverse reaction to the xenogenic cell implant during the trial period.
6

Keratin Glucocorticoid Analysis by Enzyme Immunoassay in Mammals, Birds and Reptiles

Berkvens, Charlene N. 25 April 2012 (has links)
This thesis investigates the use of an enzyme immunoassay to measure keratin glucocorticoid concentrations in mammalian hair, bird feathers and reptilian shed skins. Keratin glucocorticoid concentrations were compared to fecal glucocorticoid concentrations produced during the period of keratin growth in the African Elephant (Loxodonta africana), the Western Lowland Gorilla (Gorilla gorilla gorilla), the Sumatran Orangutan (Pongo abelii), the Domestic Chicken (Gallus gallus domesticus), the Eastern Loggerhead Shrike (Lanius ludovicianus migrans), the African House Snake (Lamprophis fuliginosus) and the Eastern Massasauga Rattlesnake (Sistrurus catenatus catenatus). Complete biochemical validation was performed for the feather and shed skin corticosterone and fecal corticosterone enzyme immunoassays in the Domestic Chicken and the African House Snake. Biological validation was performed in the Domestic Chicken. Biological and physiological validation were attempted in the African House Snake. African Elephant, Western Lowland Gorilla and Sumatran Orangutan hair cortisol concentrations ranged from 2.10 - 312.70 ng/g. African Elephant hair corticosterone concentrations ranged from 2.68 - 20.70 ng/g. Domestic Chicken and Eastern Loggerhead Shrike feather corticosterone concentrations ranged from 1.31 - 8.09 pg/mm and from 1.09 - 6.59 pg/mm, respectively. African House Snake and Massasauga Rattlesnake shed skin corticosterone concentrations ranged from 4.42 - 124.35 ng/g and 3.82 - 22.85 ng/g, respectively. In the majority of cases, a statistically significant association was not found between summary statistical measures of fecal and keratin glucocorticoid concentrations. A statistically significant positive association was detected between hair cortisol and the coefficient of variation of fecal corticosterone in the African Elephants. A statistically significant negative association was detected between feather corticosterone and the 75th percentile and coefficient of variation of fecal corticosterone in the Eastern Loggerhead Shrikes. A statistically significant positive association was also detected between shed skin corticosterone and the mean fecal corticosterone from 3 weeks before to 1 week after the previous ecdysis in the African House Snake. Feather corticosterone concentrations were significantly higher in feathers from Domestic Chickens that were socially housed with roosters than in feathers from chickens housed individually in laying cages. A statistically significant difference was not detected between the shed skin corticosterone concentrations of the minimally handled control and the weekly handled experimental African House Snakes. Adrenocorticotropic hormone stimulation did not result in the physiological validation anticipated for shed skin corticosterone concentrations in the African House Snake. / Toronto Zoological Foundation and Ontario Ministry of Agriculture, Food and Rural Affairs
7

Avaliação dos efeitos de acetato em células de neuroblastoma SH-SY5Y e células-tronco humanas de dente decíduo esfoliado cultivadas na presença de glutamato

Graça, Júlio César Gomes 11 August 2017 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-09-28T12:03:28Z No. of bitstreams: 1 juliocesargomesgraca.pdf: 1848019 bytes, checksum: f98e75e5c5ca605913fabb43b02b8b5b (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-09-28T14:14:08Z (GMT) No. of bitstreams: 1 juliocesargomesgraca.pdf: 1848019 bytes, checksum: f98e75e5c5ca605913fabb43b02b8b5b (MD5) / Made available in DSpace on 2017-09-28T14:14:08Z (GMT). No. of bitstreams: 1 juliocesargomesgraca.pdf: 1848019 bytes, checksum: f98e75e5c5ca605913fabb43b02b8b5b (MD5) Previous issue date: 2017-08-11 / O glutamato, aminoácido não-essencial, é um neurotransmissor excitatório do sistema nervoso central (SNC), sendo liberado durante o impulso nervoso. Em situações de patologia cerebral, o acúmulo de glutamato ocorre no espaço extracelular, causando dano neuronal e, eventualmente, apoptose. Muitos trabalhos relataram que a citotoxicidade do glutamato está associada a várias doenças neurológicas. Neste contexto, o acetato, um ácido graxo de cadeia curta, pode beneficiar o SNC de forma energética e estrutural. A acetil-coenzima A, forma metabolicamente ativa de acetato, é utilizada como substrato em vias bioquímicas envolvidas no metabolismo de carboidratos, lipídios e proteínas, além de aumentar a acetilação das histonas, alterando a expressão de genes inflamatórios. A linhagem celular de neuroblastoma humano SH-SY5Y é comumente usada em estudos relacionados a doenças neurodegenerativas, com uma capacidade de expansão em larga escala antes da diferenciação, enquanto que a linhagem de células-tronco de polpa de dente de leite decíduo esfoliado (SHED) é comumente utilizada em modelos de estudo do comportamento celular. O objetivo desta pesquisa foi avaliar os efeitos do acetato mediante a citotoxicidade causada pelo glutamato em células SH-SY5Y e SHED. Células SH-SY5Y e SHED foram cultivadas, respectivamente, em meio DMEM/F12 suplementado com 10% (v/v) de soro fetal bovino (SFB) e 1% (v/v) de penicilina-estreptomicina, e meio alfa-MEM, suplementado com 10% (v/v) de SFB, 1% (v/v), 1% (v/v) de penicilina-estreptomicina, 0,01 mM de aminoácidos não essenciais e 2 mM L-glutamina. A viabilidade celular em diferentes concentrações de acetato (5 a 75 mM) e glutamato (25 a 150mM) foi medida pelo ensaio MTT. A diferenciação foi realizada em SH-SY5Y pela suplementação do meio com 10 μM de ácido retinóico (AR) e redução de SFB para 1% (v/v) durante 4, 7 e 10 dias em cultura, e em SHED pela substituição do meio de cultivo por DMEM Low-Glicose, suplementado com 10% (v/v) de SFB, 1% (v/v) de penicilina-estreptomicina, 10-7 M de dexametasona, 50 μM de 2-fosfato ácido ascórbico e 2 mM de β-glicerolfosfato, a fim de verificar como essas células respondem à mistura de acetato/glutamato. A análise estatística foi realizada teste ANOVA de uma ou duas vias, bem como pelo teste de Kruskal-Wallis, quando apropriado, com p < 0,05 considerado estatisticamente significativo. Após 7 dias de incubação, as concentrações de 5 e 25 mM de acetato apresentaram menor influência sobre a viabilidade de células SH-SY5Y e SHED, enquanto que o IC50% de glutamato ficou em torno de 75mM e 50mM para estas linhagens, respectivamente. Ao submeter as células ao tratamento combinado de acetato e glutamato, observou-se que o acetato não exerceu citoproteção mediante exposição celular ao glutamato. Após análise qualitativa da diferenciação osteogênica em SHEDs, foi observado maior mineralização nas células tratadas com AR e acetato, em comparação com as células controle. Estudos subsequentes, que permitam identificar como tais células respondem ao acetato em nível molecular, considerando a expressão de ciclinas, compactação da cromatina e a presença de marcadores bioquímicos característicos durante a diferenciação de cada linhagem, por exemplo, poderão fornecer um entendimento mais completo de como esse composto atua na dinâmica metabólica e bioenergética celular. / Glutamate, a non-essential amino acid, is an excitatory neurotransmitter of the central nervous system (CNS), being released during the nerve impulse. In situations of cerebral pathology, the accumulation of glutamate occurs in the extracellular space, causing neuronal damage and, eventually, apoptosis. Many studies have reported that glutamate cytotoxicity is associated with various neurological diseases. In this context, acetate, a short chain fatty acid, can benefit the CNS energetically and structurally. Acetyl-coenzyme A, a metabolically active form of acetate, is used as a substrate in biochemical pathways involved in the metabolism of carbohydrates, lipids and proteins, in addition to increasing the acetylation of histones, altering the expression of inflammatory genes. The SH-SY5Y human neuroblastoma cell line is commonly used in studies related to neurodegenerative diseases, with a large scale expansion capacity prior to differentiation, whereas the stem cell line of exfoliated deciduous teeth (SHED) is commonly used in models of cellular behavior. The objective of this research was evaluate the effects of acetate by glutamate-induced cytotoxicity on SH-SY5Y and SHED cells. SH-SY5Y and SHED cells were cultured respectively in DMEM / F12 medium supplemented with 10% (v/v) fetal bovine serum (FBS) and 1% (v/v) penicillin-streptomycin, and alpha-MEM medium, supplemented with 10% (v/v) FBS, 1% (v/v), 1% (v/v) penicillin-streptomycin, 0.01 mM non-essential amino acids and 2 mM L-glutamine. Cell viability at different concentrations of acetate (5 to 75 mM) and glutamate (25 to 150 mM) was measured by the MTT assay. Differentiation was performed on SH-SY5Y by supplementing the medium with 10 μM retinoic acid (RA) and reducing FBS to 1% (v/v) for 4, 7 and 10 days in culture, and in SHED by replacing the culture medium with DMEM Low-Glucose, supplemented with 10% (v/v) FBS, 1% (v/v) penicillin-streptomycin, 10-7 M dexamethasone, 50 μM ascorbic acid 2-phosphate and 2 mM β- Glycerol phosphate in order to verify how these cells respond to the acetate/glutamate mixture. Statistical analysis was performed one-way or two-way ANOVA, as well as Kruskal-Wallis test, when appropriate, with p < 0.05 considered statistically significant. After 7 days of incubation, concentrations of 5 and 25 mM acetate had less influence on the viability of SH-SY5Y and SHED cells, whereas the IC50% of glutamate was around 75mM and 50mM for these lines, respectively. By subjecting the cells to the combined treatment of acetate and glutamate, it was observed that acetate did not exert cytoprotection through cellular exposure to glutamate. After qualitative analysis of the osteogenic differentiation in SHEDs, greater mineralization was observed in the cells treated with RA and acetate, in comparison with the control cells. Subsequent studies to identify how these cells respond to acetate at the molecular level, considering the expression of cyclins, chromatin compaction, and the presence of characteristic biochemical markers during differentiation of each lineage, for example, may provide a more complete understanding of how this component acts on the metabolic dynamics and cellular bioenergetics.
8

The role of shed GP in Ebola virus pathogenicity / Le rôle de la shed GP dans la pathogénicité du virus Ebola

Escudero Pérez, Beatriz 03 October 2014 (has links)
Au cours de l’infection par le virus Ebola (EBOV), plusieurs glycoprotéines solubles sont massivement libérées à partir de cellules infectées mais le rôle précis de ces protéines virales n’a pas encore été identifié. Nous émettons l'hypothèse que l'altération de l’hémostase et du système et vasculaires observée au cours de l'infection à virus Ebola pourrait être, au moins en partie causée par ces glycoprotéines solubles. Ainsi pour la première fois, nous avons identifié les cibles cellulaires de la protéine soluble « shed GP » d’Ebola et nous avons démontré que sa partie glycosylé peut activer les cellules dendritiques et les macrophages non infectés, induisant, par le récepteur TLR4, la sécrétion de cytokines pro-inflammatoires. Nous démontrons aussi que l'activité de la shed GP est neutralisé lors de l'addition de la MBL, une protéine connue pour interagir avec certains motifs glycosylés présents à la surface de différents micro-organismes. Nous avons également montré que la shed GP active la perméabilité des HUVEC de façon directe et indirecte, via la libération de cytokines. En conclusion, cette étude suggère que la shed GP peut être l'un des principaux facteurs responsables de la stimulation précoce des cellules immunitaires qui produisent alors de grandes quantités de cytokines pro-inflammatoires, des éléments qui, combinés avec la réplication massive du virus et les dommages cellulaires induits par le virus, peuvent conduire à un syndrome de type choc septique et une mortalité élevée. / During Ebola virus (EBOV) infection several soluble glycoproteins are released in high amounts from infected cells but as yet still no clear role has been identified for these viral proteins. We hypothesized that the impairment of coagulation and vascular systems observed during EBOV infection could be, at least in part, due to these soluble glycoproteins.Here, for the first time we identify the cellular targets of EBOV soluble protein shed GP and provide evidence that through its glycosylation, shed GP can activate non-infected dendritic cells and macrophages, inducing, through TLR4, the secretion of pro-inflammatory cytokines. We also demonstrate that shed GP activity is negated upon addition of Mannose-Binding sera Lectin (MBL), a molecule known to interact with sugar arrays present on the surface of different microorganisms. We have also revealed that shed GP activates permeability of HUVECs both directly and indirectly through cytokine release. Overall, this study suggests that shed GP may be one of the principal factors responsible for the early stimulation of immune cells that then produce high amounts of proinflammatory cytokines that, combined with massive virus replication and virus-induced cell damage, can lead to a septic shock-like syndrome and high mortality.
9

Modelagem neuronal de pacientes com distrofia muscular de Duchenne utilizando células pluripotentes induzidas / Neuronal modelling with Duchenne muscular dystrophy patients using pluripotent stem cells

Fernandes, Isabella Rodrigues 22 April 2015 (has links)
A Distrofia Muscular de Duchenne (DMD) é uma patologia neuromuscular causada pela mutação ou deleção do gene da distrofina, localizado no cromossomo X, levando a degeneração muscular ao longo da vida do paciente. A doença também tem sido associada a déficit cognitivo e falta de habilidade comportamental. Pesquisas com células neurais de pacientes com DMD poderiam ajudar a elucidar os sintomas neurológicos associados. Neste trabalho, através de células-tronco pluripotentes induzidas (iPSC) derivadas da polpa de dente decíduo esfoliado (SHED) de pacientes com DMD modelamos a DMD produzindo células neurais vivas in vitro. A expressão da distrofina foi verificada durante e após a diferenciação neuronal e nos ensaios de imunofluorescência, mostrando que essa proteína está presente em células do SNC. Na análise gênica através do qPCR, a Dp71 e a Dp140, isoformas da distrofina, apresentavam uma expressão menor do que os controles. Além disso, as análises das sinapses baseada na colocalização de marcadores pré e pós-sinápticos (Sinapsina1 e Homer 1) revelaram que os neurônios dos pacientes com DMD tinham menor quantidade de sinapses que os controles, reforçando o papel da distrofina no SNC. Logo, a expressão de genes relacionados a plasticidade sináptica revelou 10 genes alterados nos neurônios dos pacientes DMD, sugerindo que a mutação no gene da distrofina possivelmente altera a plasticidade sináptica e pode estar envolvida na habilidade cognitiva destes pacientes. Desta forma, com base nos nossos achados, a modelagem neuronal de DMD é factível e pode auxiliar a elucidar os mecanismos da fisiopatologia da doença / The Duchenne muscular dystrophy (DMD) is a neuromuscular disorder caused by a mutation or deletion of the dystrophin gene located on the X chromosome, leading to muscle degeneration throughout the patient\'s life. The disease has also been associated with cognitive impairment and lack of behavioral skill. Research on neural cells from patients with DMD could help to elucidate the neurological symptoms associated. In this work, through induced pluripotent stem cells (iPSC) derived from dental pulp exfoliated (SHED) of patients with DMD model the DMD producing living neural cells in vitro. The dystrophin expression was observed during and after neuronal differentiation and immunofluorescence assays, showing that this protein is present in CNS cells. In gene analysis by qPCR, the Dp71 and Dp140, isoforms of dystrophin, had a lower expression than controls. Furthermore, based on analysis of synapses colocalization pre and postsynaptic markers (Synapsin1 and Homer 1) showed that neurons of DMD patients had lower number of synapses controls, supporting a role for dystrophin in the CNS. Finally, the expression of synaptic plasticity related genes wasfound in 10 genes altered in neurons of DMD patients, suggesting that the mutation of the dystrophin gene possibly alters synaptic plasticity and may be involved in cognitive ability of these patients. Finally, based on our findings, neuronal modeling DMD is feasible and may help elucidate the mechanisms of pathophysiology of the disease
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Modelagem neuronal de pacientes com distrofia muscular de Duchenne utilizando células pluripotentes induzidas / Neuronal modelling with Duchenne muscular dystrophy patients using pluripotent stem cells

Isabella Rodrigues Fernandes 22 April 2015 (has links)
A Distrofia Muscular de Duchenne (DMD) é uma patologia neuromuscular causada pela mutação ou deleção do gene da distrofina, localizado no cromossomo X, levando a degeneração muscular ao longo da vida do paciente. A doença também tem sido associada a déficit cognitivo e falta de habilidade comportamental. Pesquisas com células neurais de pacientes com DMD poderiam ajudar a elucidar os sintomas neurológicos associados. Neste trabalho, através de células-tronco pluripotentes induzidas (iPSC) derivadas da polpa de dente decíduo esfoliado (SHED) de pacientes com DMD modelamos a DMD produzindo células neurais vivas in vitro. A expressão da distrofina foi verificada durante e após a diferenciação neuronal e nos ensaios de imunofluorescência, mostrando que essa proteína está presente em células do SNC. Na análise gênica através do qPCR, a Dp71 e a Dp140, isoformas da distrofina, apresentavam uma expressão menor do que os controles. Além disso, as análises das sinapses baseada na colocalização de marcadores pré e pós-sinápticos (Sinapsina1 e Homer 1) revelaram que os neurônios dos pacientes com DMD tinham menor quantidade de sinapses que os controles, reforçando o papel da distrofina no SNC. Logo, a expressão de genes relacionados a plasticidade sináptica revelou 10 genes alterados nos neurônios dos pacientes DMD, sugerindo que a mutação no gene da distrofina possivelmente altera a plasticidade sináptica e pode estar envolvida na habilidade cognitiva destes pacientes. Desta forma, com base nos nossos achados, a modelagem neuronal de DMD é factível e pode auxiliar a elucidar os mecanismos da fisiopatologia da doença / The Duchenne muscular dystrophy (DMD) is a neuromuscular disorder caused by a mutation or deletion of the dystrophin gene located on the X chromosome, leading to muscle degeneration throughout the patient\'s life. The disease has also been associated with cognitive impairment and lack of behavioral skill. Research on neural cells from patients with DMD could help to elucidate the neurological symptoms associated. In this work, through induced pluripotent stem cells (iPSC) derived from dental pulp exfoliated (SHED) of patients with DMD model the DMD producing living neural cells in vitro. The dystrophin expression was observed during and after neuronal differentiation and immunofluorescence assays, showing that this protein is present in CNS cells. In gene analysis by qPCR, the Dp71 and Dp140, isoforms of dystrophin, had a lower expression than controls. Furthermore, based on analysis of synapses colocalization pre and postsynaptic markers (Synapsin1 and Homer 1) showed that neurons of DMD patients had lower number of synapses controls, supporting a role for dystrophin in the CNS. Finally, the expression of synaptic plasticity related genes wasfound in 10 genes altered in neurons of DMD patients, suggesting that the mutation of the dystrophin gene possibly alters synaptic plasticity and may be involved in cognitive ability of these patients. Finally, based on our findings, neuronal modeling DMD is feasible and may help elucidate the mechanisms of pathophysiology of the disease

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