• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 25
  • 21
  • 5
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 62
  • 62
  • 58
  • 27
  • 25
  • 23
  • 11
  • 10
  • 9
  • 9
  • 9
  • 8
  • 8
  • 7
  • 7
  • 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.
51

Scar-free wound healing and regeneration in the leopard gecko (Eublepharis macularius)

Delorme, Stephanie 28 October 2011 (has links)
Scar-free wound healing and regeneration are uncommon phenomena permitting the near complete restoration of damaged tissues, organs and structures. Although rare in mammals, many lizards are able to undergo scarless healing and regeneration following loss of the tail. This study investigated the spontaneous and intrinsic capacity of the leopard gecko (Eublepharis macularius) tail to undergo scar-free wound healing and regeneration following two different forms of tail loss: autotomy, a voluntary and evolved mechanism of tail shedding at fracture planes; and surgical amputation, involuntary loss of the tail outside the fracture planes. Furthermore, I investigated the ability of the regenerate tail to regenerate by amputating a regenerate tail (previously lost by autotomy). To investigate these phenomena I imaged wound healing and regenereating tails daily (following autotomy and amputation) to document gross morphological changes. I used histochemistry to document tissue structure and immunohistochemistry to determine the tissue/cellular location of my five proteins of interest (PCNA, MMP-9, WE6, α-sma, TGF-β3). Each of these proteins of interest has been previously documented during wound healing and/or regeneration in other wound healing/regeneration model organisms (e.g. mice, urodeles, lizards, zebrafish). Scar-free wound healing and regeneration occurred following autotomy, amputation of the original tail and amputation of the regenerate tail, indicating that the leopard gecko tail has an instrinsic scar-free wound healing and regenerative capacity that is independent of the mode of tail loss (autotomy or amputation). Furthermore immunohistochemistry revealed a conserved sequence and location of the expression of the five proteins of interest following both forms of tail loss. These results provide the basis for further studies investigating scar-free wound healing and regeneration in a novel amniote model, the leopard gecko. / NSERC
52

Étude de l'activité anti-cancéreuse du PCK3145, un peptide dérivé de PSP-94, sur les cancers hématologiques

Guérin, Mireille 08 1900 (has links)
Le PCK3145 est un peptide de 15 acides aminés inhibant la sécrétion de MMP-9 et démontrant une activité anti-tumorale contre le cancer de la prostate. Comme les cancers hématologiques sécrètent MMP-9, nous avons donc évalué l’effet du PCK3145 sur ces cancers. Nous avons démontré que les lignées humaines de lymphome non- Hodgkinien (LNH) SR et de myélome multiple RPMI-8226 ainsi que la lignée murine de mastocytome P815 ont une prolifération réduite suite à une exposition au PCK3145. Ce peptide diminue également la clonogénicité de ces cellules. In vivo, le PCK3145 diminue significativement la croissance des tumeurs sous-cutanées P815 comparativement au PBS (p<0.001) et aux peptides contrôles (« scrambled peptide » (p<0.05) et PCK5266 (p<0.01)). De plus, le traitement au PCK3145 diminue le nombre de métastases au niveau du foie par rapports aux contrôles (p<0.05). Les niveaux de MMP-9 dans le sang des souris traitées au PCK3145 sont similaires à ceux dans le sang des souris sans tumeur. Par contre, chez les souris recevant le PBS ou le « scrambled peptide », les niveaux de MMP-9 étaient significativement plus élevés que dans les souris sans tumeur et les souris traitées au PCK3145 (p<0.05). De surcroît, dans un modèle de xénogreffe, le PCK3145 diminue significativement la croissance des lymphomes SR par rapport au PBS (p<0.01) et au « scrambled peptide » (p<0.001). Ces résultats indiquent que le PCK3145 possède une activité anti-tumorale et pourrait représenter un agent intéressant pour le traitement de plusieurs cancers hématologiques. / PCK3145 has been shown to exert anti-tumor activity against prostate cancer cells. In a Phase I clinical study, this peptide demonstrated low toxicity. To determine whether PCK3145 could exert cytotoxic activity against other marrow infiltrating cancers, we tested its activity against hematologic cancers. Interestingly, PCK3145 inhibited the proliferation of human NHL (SR) and myeloma (RPMI-8226) cell lines and murine mastocytoma (P815) cell line in vitro. Moreover, PCK3145 reduced the clonogenicity of these cell lines. To explore its activity in vivo, DBA/2 mice were injected with P815 cells. PCK3145 treatment significantly decreased P815 tumors growth in comparison to PBS (p<0.001), scrambled peptide (p<0.05) and PCK5266 (amino acids 52-66 of PSP-94) (p<0.01). Intraperitoneal PCK3145 treatment led to a decreased number of liver metastasis compared to PBS (p<0.05) and scrambled peptide (p<0.05). MMP-9 levels, measured by ELISA, in the peripheral blood of treated P815 bearing mice were similar to those obtained with healthy animals (12.83 1.890 (mean SD) ng/ml and 6.48 0.4070 ng/ml, respectively), while MMP-9 levels were elevated in mice treated with PBS and scrambled peptide (35.12 8.559 ng/ml and 22.60 3.944 ng/ml, respectively; p<0.05). In NOD/SCID mice PCK3145 treatment resulted in significant inhibition of human NHL SR growth compared to treatment with PBS (p<0.001) and scrambled peptide (p<0.01). Consequently, treatment with PCK3145 can reduce tumor cell proliferation of murine and human hematologic cancers. In addition, PCK3145 has the potential to inhibit tumor cells dissemination by lowering MMP-9 secretion. Thus, PCK3145 represents a unique peptide demonstrating sequence-specific anti-tumor activity hematologic malignancies.
53

Estudos de fenômenos de osteogênese em implantes de polímero vegetal / A study of osteogenesis phenomena in plaint polymer implants

Wallace Rocha Saran 14 October 2011 (has links)
O objetivo deste estudo foi analisar a modulação da expressão de metaloproteinases da matriz-2 e -9, no tecido ósseo neoformado na interface do implante derivado do polímero da mamona (Ricinus communis) com o canal medular da tíbia de coelhos, por meio de análise histológica por microscopia óptica, tomografia computadorizada e imunoistoquímica. Foram selecionados 44 coelhos machos, Oryctolagus cuniculus, da linhagem Nova Zelândia, albinos, divididos em dois grupos, sendo o Grupo 1, composto por 12 animais controle, cujas fresagens do canal medular foram produzidas bilateralmente nas tíbias e não preenchidas e, o Grupo 2, com 30 animais, cujos canais medulares da tíbia, após fresagem, foram preenchidos bilateralmente com os cilindros derivados da poliuretana da mamona. Os animais do Grupo 1 e Grupo 2 foram divididos aleatoriamente em subgrupos experimentais, conforme as datas de eutanásia pré-determinadas em 90, 120, 150 dias após o ato operatório. Um animal não foi submetido ao procedimento de fresagem, sendo utilizado para controle histológico e outro submeteu-se à eutanásia após o implante do polímero, sendo utilizado para controle de imagem do estudo com tomografia computadorizada. Decorridos os períodos experimentais, os animais foram submetidos à eutanásia, as peças removidas e encaminhadas para o exame tomográfico; posteriormente ao processamento histológico, as lâminas foram analisadas em microscópio óptico. As Metaloproteinases da Matriz (MMPs) são um importante grupo de enzimas proteolíticas zinco-dependentes responsáveis pela degradação de matriz extracelular e membranas basais. As enzimas são secretadas em uma forma latente e se tornam ativadas no ambiente pericelular, sendo relacionadas a processos fisiológicos e patológicos. No presente estudo, foram revisados alguns aspectos importantes das MMPs, discutindo-se o papel dessas enzimas em processos fisiológicos como a neoformação e maturação óssea (MMP-2). Dentre os processos patológicos que envolvem a participação das MMPs, destacam-se a reabsorção óssea e processos inflamatórios (MMP-9). A expressão de metaloproteinase da matriz-2 e -9 nos tecidos foi avaliada por meio de imunoistoquímica. Os dados obtidos foram submetidos à análise estatística por meio do teste ANOVA seguido pelo pós-teste de Tukey (&alpha; = 0,05). No grupo experimental, aos 90 dias, a interface com o polímero apresentava uma camada espessa de tecido ósseo neoformado rico em osteócitos, o qual apresentou uma maturação com o passar do tempo, aos 120 e 150 dias pós-implantação. No grupo controle, a superfície interna junto ao canal medular apresentava-se revestida por osteoblastos, seguida de faixa de tecido ósseo, com poucas lacunas preenchidas por osteócitos. O amadurecimento do tecido da superfície interna medular acontece na região interior, sendo o osso alamelar, constituído por fibras colágenas menos amadurecidas que o osso lamelar. As imagens tomográficas demonstraram não haver espaço entre a superfície do material e do osso na interface implante/medula óssea, sendo a densidade dos tecidos nesta interface semelhante à densidade das demais porções da medula óssea. O processo de remodelação óssea observado histologicamente foi acompanhado pela modulação positiva de metaloproteinase da matriz-2 durante todo o período de avaliação com baixa expressão de metaloproteinase da matriz-9. / The aim of this study was to evaluate the modulation of matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9) expression in newly formed bone tissue at the interface between implant derived from castor oil (Ricinus communis) polymer and the medullary canal of rabbit tibia, by histological examination under optical microscopy, computed tomography (CT) and immunohistochemical analysis. For such purpose, 44 rabbits (Oryctolagus cuniculus, New Zealand, albinus) were selected and assigned to two groups. In Group 1, composed of 12 animals (control), reamings of the medullary canal were produced bilaterally in the tibiae of the rabbits and were not filled. In Group 2, composed of 30 animals, the tibial medullary canals, after reaming, were filled bilaterally with cylinders derived from castor oil polyurethane. The animals of Groups 1 and 2 were randomly divided in experimental subgroups, according to the periods of predetermined euthanasia, which were 90, 120, 150 days postoperatively. One animal was not subjected to the reaming procedure, and served as a histological control; another animal was killed after placement of the polymer implant, and served as a control for CT imaging. Euthanasia was undertaken at the established experimental periods, and the anatomic specimens were removed and subjected to CT analysis. Then, after histological processing, the slides were examined under optical microscopy. MMPs are an important group of zinc-dependent proteolytic enzymes responsible for the degradation of extracellular matrix and basal membranes. The enzymes are synthesized in a latent form and are activated in the pericellular environment, being involved in physiological and pathological processes. In the present study, some important aspects of MMPs were reviewed, and the role of these enzymes in physiological processes, such as new bone formation and bone maturation (MMP-2), was discussed. Among the pathological processes that have the participation of MMPs, the most relevant are bone resorption and inflammatory processes (MMP-9). MMP-2 and MMP-9 expression in the tissues was evaluated by immunohistochemistry. Data were subjected to statistical analysis by ANOVA and Tukey post-test (&alpha; = 0.05). In the group experimental, at 90 days, the interface with the polymer presented a thick layer of newly formed bone tissue rich in osteocytes. This tissue exhibited an ongoing maturation at 120 and 150 days post-implantation. In the control group, the internal surface close to the medullary canal was lined by osteoblasts, followed by a bone tissue zone with few lacunae filled with osteocytes. Maturation of the tissue of the medullary internal surface occurred in the inner region, with the bone being alamellar, that is, constituted of collagen fibers less maturated than the lamellar bone. The CT scans showed no space between the material surface and the bone at the implant/bone marrow interface, and the density of the tissues at this interface was similar to the density measured in the other regions of the bone marrow. The bone remodeling process observed histologically was accompanied by positive modulation of MMP-2 during the entire evaluation period and low MMP-9 expression.
54

Expressão aumentada dos antígenos de MMP-9 PPAR, Chlamydophila pneumoniae e Mycoplasma pneumoniae em fragmentos ateroscleróticos de aorta com aneurisma / Increased expression of MMP-9, PPAR a and Chlamydophila pneumoniae e Mycoplasma pneumoniae antigens in atherosclerostic aortic fragments with aneurysms

Alessandra Roggerio 12 September 2008 (has links)
Introdução: Aneurisma de aorta é considerado uma doença inflamatória crônica, mas ainda é controverso se está relacionado a aterosclerose aos agentes infecciosos. Antígenos de Chlamydophila pneumoniae (CP) e Mycoplasma pneumoniae (MP) foram encontrados em grande quantidade nas placas instáveis que usualmente estão associadas a remodelamento positivo e inflamação do vaso. Metaloproteinase da matriz 9 (MMP-9) está implicada na fragilidade da parede vascular e na formação dos aneurismas. Os efeitos imunomodulatórios dos receptores ativados por proliferador de peroxissomo (PPARs) têm sido relacionados à aterosclerose. Objetivos: Comparar lesões ateroscleróticas graves com e sem aneurisma do ponto de vista inflamatório e infeccioso, analisando antígenos de MP e CP e expressão de MMP-9, TIMP-1 e PPARs. Métodos: No presente estudo quantificamos, através da técnica de imunoistoquímica, antígenos de MMP- 9, TIMP-1, PPARs a e , e dos agentes infecciosos CP e MP em fragmentos de aorta ateroscleróticos com aneurisma (n=14) e sem aneurisma (n=14). Resultados: A adventícia e o tecido adiposo periadventicial (TAP) dos aneurismas apresentaram intensa inflamação. Expressão de MMP-9 esteve aumentada no TAP e agentes infecciosos, TIMP-1 e PPAR a estiveram aumentados na adventícia e no TAP, sem diferença em relação a expressão de PPAR . Colágeno, TIMP-1 e PPARs estiveram positivamente correlacionados no grupo com aterosclerose, mas não no grupo com aneurisma. Conclusão: Nossos achados sugerem que aneurisma de aorta é uma complicação das lesões ateroscleróticas. Quantidade aumentada de Chlamydophila pneumoniae e Mycoplasma pneumoniae na adventícia e PAT sem correlação da resposta de TIMP-1 e PPARs são achados que estão associados com a presença de aneurisma nos segmentos de aorta ateroscleróticos / Introduction: Aortic aneurysm is considered a chronic inflammatory disease, but remains a controversial matter if it is related to atherosclerosis and infectious agents. Chlamydophila pneumoniae (CP) and Mycoplasma pneumoniae (MP) antigens were found in higher amount in unstable plaques that are usually associated to positive remodeling and vessel inflammation. Matrix metalloproteinase 9 (MMP-9) has been implicated in vascular wall fragility and aneurysm development. The immunemodulator effects of peroxisome proliferators - activated receptor (PPARs) have been related to atherosclerosis. Objectives: To compare severe atherosclerotic lesions with and without aneurysms by inflammatory and infectious point of view, analyzing MP and CP, MMP-9, TIMP-1 and PPARs antigens. Methods: In the present study we quantified, using immunohistochemistry technique, MMP-9, TIMP-1, PPAR a and and infectious agents CP and MP antigens in aortic atherosclerotic fragments with aneurysms. (n=14) and without aneurysms (n=14). Results: Adventitia and periadventitial adipose tissue (PAT) from aneurysms showed intense inflammation. MMP-9 expression has increased in PAT and the infectious agents, TIMP-1 and PPAR a were increased in adventitia and PAT in aneurysmatic group, without difference related to PPAR expression. Collagen, TIMP-1 and PPARs were positively correlated in atherosclerotic group, but it was not observed in aneurysmatic group. Conclusion: Our data have suggested that aortic aneurysm is a complication of aortic atherosclerotic lesions. Increased amount of Chlamydophila pneumoniae and Mycoplasma pneumoniae in the adventitia and PAT without a correlated TIMP-1 and PPARs response are findings that were associated with the presence of aneurysm in atherosclerotic aortic segments
55

Análise da expressão plasmática e tecidual das metaloproteinases de matriz 2 e 9 e do inibidor tecidual de metaloproteinase-2 em pacientes com adenomas hipofisários e sua correlação com comportamento tumoral invasivo / Analysis of plasma and tissue expression of matrix metalloproteinases 2 and 9 and the tissue inhibitor of metalloproteinase type 2 in patients with pituitary adenomas and their correlation with invasive tumor behavior

Ane Caroline Thé Bonifácio Freire 02 February 2018 (has links)
Os tumores hipofisários mesmo sendo, em sua maioria, benignos, podem apresentar comportamento invasivo, com extensão para seio cavernoso, seio esfenoidal e clivo. As metaloproteinases de matriz tipo 2 (MMP-2) e 9 (MMP-9) e o inibidor tecidual de metaloproteinases-2 (TIMP-2) têm sido estudados em relação ao comportamento invasivo desses tumores, em especial quanto à invasão do seio cavernoso. Esse estudo teve como objetivo avaliar a expressão proteica das MMP-2, MMP-9 e do TIMP-2 nos tumores hipofisários e sua relação com invasão do seio cavernoso e, de maneira inédita, investigar a expressão dessas proteínas em nível plasmático. Adicionalmente, foram avaliadas a expressão dos RNAs mensageiros (RNAm) das MMP-2 e TIMP-2 com intuito de correlacioná-las com a expressão proteica no tecido tumoral, bem como a expressão do marcador de proliferação Ki67. Foram selecionados 77 casos, todos com amostras de tumor emblocado em parafina para análise imuno-histoquímica (IHQ). Destes, foram coletadas amostras de tumor fresco em 29 pacientes e de sangue periférico pré-operatório em outros 29 casos. A expressão proteica plasmática foi detectada de forma semi-quantitativa utilizando um arranjo de anticorpos em membrana comercial. A expressão dos RNAm das MMP-2 e TIMP-2 foi avaliada por reação em cadeia da polimerase quantitativo (qPCR) em tempo real. Do total de casos, 20 pacientes apresentavam tumores com invasão para o seio cavernoso. A expressão proteica tumoral das MMP-2, MMP-9 e TIMP-2 apresentou-se aumentada no grupo invasivo, contudo esta diferença não foi estatisticamente significante em relação ao grupo não- invasivo. A expressão plasmática das MMP-9 e TIMP-2 também não mostrou diferença entre os dois grupos e não se correlacionou com a expressão tumoral. A expressão plasmática da MMP-2 não foi detectada em nenhum caso. Quanto à expressão do RNAm das MMP-2 e TIMP-2, também não houve diferença significante entre os grupos e nem correlação com a expressão proteica tecidual ou plasmática. Foi observada uma diferença significante na dimensão tumoral [3.6 (2.5-5.2) x 2.0 (1.3-2.7); P < 0.001] e no índice do Ki67 [1.05 (0.27-25) x 0.5 (0.2-1.0); P < 0.001] entre os grupos invasivo e não-invasivo respectivamente. Em conclusão, em nossa coorte, não foi encontrada relação entre a expressão tecidual e plasmática das MMP-2, MMP-9 e TIMP-2 e a invasão para o seio cavernoso nos adenomas hipofisários / Pituitary tumors, although mostly benign, may present invasive behavior, with extension to the cavernous sinus, sphenoid sinus and clivus. Type 2 (MMP-2) and type 9 (MMP-9) matrix metalloproteinases and the metalloproteinase tissue inhibitor type 2 (TIMP-2) have been studied in relation to the invasive behavior of these tumors, especially regarding invasion of the cavernous sinus. The aim of this study was to evaluate the protein expression of MMP-2, MMP-9 and TIMP-2 in pituitary tumors and its relation with invasion of the cavernous sinus and, in an unprecedented way, to investigate the expression of these proteins at the plasma level. Additionally, expression of MMP-2 and TIMP-2 messenger RNAs (mRNAs) was evaluated in order to correlate with protein expression in tumor tissue, as well as Ki67 proliferation marker expression. A total of 77 cases were selected, all of them with paraffin embedded tumor samples for immunohistochemical analysis (IHC). Of these, fresh tumor samples were collected in 29 patients and preoperative peripheral blood in another 29 cases. Protein plasma expression was detected semi-quantitatively using a commercial membrane antibody array. Expression of MMP-2 and TIMP-2 mRNAs was evaluated by quantitative realtime polymerase chain reaction (qPCR). Of the total cases, 20 patients presented tumors invasive to the cavernous sinus. Tumor protein expression of MMP-2, MMP-9 and TIMP-2 was increased in the invasive group, not reaching, however, statistically significant difference as compared with the non-invasive group. Plasma expression of MMP-9 and TIMP-2 also did not differ between the two groups and did not correlate with tumor expression. Plasma expression of MMP-2 was not detected in any case. Concerning MMP-2 and TIMP-2 mRNA expression, there was also no significant difference between groups and no correlation with tissue or plasma protein expression was observed. A significant difference was observed in tumor size [3.6 (2.5-5.2) x 2.0 (1.3-2.7); P < 0.001] and in the Ki67 index [1.05 (0.27-25) x 0.5 (0.2-1.0); P < 0.001] between the invasive and non-invasive groups respectively. In conclusion, in our cohort, no relationship was found between the tissue and plasma expression of MMP-2, MMP-9 and TIMP-2 and the invasion of the cavernous sinus in pituitary adenomas
56

The Responses of Human Neutrophils to Tobacco Smoke Components

Al-Shibani, Nouf Khider January 2012 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Tobacco smoking is considered a major modifiable risk factor for periodontal disease. Tobacco contains about 6700 compounds and almost 4000 compounds of these have been identified in tobacco smoke. Nicotine is the addictive ingredient in tobacco and has been shown to affect multiple cellular processes. Cigarette smoke condensate (CSC) is the particulate matter of smoke. It is believed to be a powerful inducer of inflammatory responses. Neutrophils are the first line of host defense and are critical cells in the maintenance of periodontal health through their role in the control of bacteria, but they can also contribute to the progression of periodontal disease by the production and release of reactive oxygen species (ROS). Virulence factors from periodontal pathogens, such as Porphyromonas gingivalis (P. gingivalis), stimulate the respiratory burst of neutrophils. In this dissertation, three studies aimed at understanding the oxidative activity of neutrophils when stimulated with either nicotine, cigarette smoke condensate (CSC) or four other components of tobacco smoke (2-naphthylamine, hydroquinone, acrolein, and acetaldehyde) with or without P. gingivalis supernatant. The release of matrix metalloproteinase-9 (MMP-9) was also examined. ROS production increased significantly when the neutrophils were stimulated with nicotine. P. gingivalis induced the maximum ROS production when compared to all the other components examined. The combination of nicotine and P. gingivalis did not have an additive effect on ROS production. Nicotine significantly increased the MMP-9 release from the neutrophils. On the contrary, CSC inhibited ROS production at all the concentrations examined. The combination of CSC and P. gingivalis resulted in the inhibition of ROS production. MMP-9 release was also increased from the CSC-treated neutrophils. The four other tobacco smoke components examined affected ROS production and MMP-9 release differently. These projects demonstrated that CSC inhibited the ROS production from neutrophils, which can be attributed to several components in tobacco smoke that may include acrolein and hydroquinone. More research is needed to determine the mechanisms of inhibition and if other tobacco components are involved in ROS inhibition
57

Stress oxydatif cérébrovasculaire et rupture de la barrière hémato-encéphalique dans le syndrome de Wernicke-Korsakoff expérimental

Beauchesne, Élizabeth 03 1900 (has links)
Le syndrome de Wernicke-Korsakoff (SWK) est un désordre neuropsychiatrique causé par la déficience en thiamine (DT). Dans la DT expérimentale comme dans le SWK, on observe une mort neuronale et des hémorragies dans certaines régions précises du diencéphale et du tronc cérébral. Les lésions diencéphaliques du SWK sont particulièrement sévères et entraînent souvent des séquelles amnésiques permanentes. Le lien entre la dysfonction métabolique induite par la DT et la mort neuronale n’est pas connu. Des rapports précédents ont démontré que la perméabilité de la barrière hémato-encéphalique (BHE) était altérée et ce, précédant l’apparition du dommage neuronal, suggérant un rôle critique de la dysfonction vasculaire. Les jonctions serrées (JS) interendothéliales, la base anatomique de la BHE, constituent un réseau moléculaire incluant l’occludin et les zonula occludens (ZOs). Cette thèse démontre une perte d’expression et une altération de la morphologie de ces protéines en relation avec la dysfonction de la BHE dans le thalamus de souris déficientes en thiamine, fournissant une explication pour la présence d’hémorragies. Le stress oxydatif peut entraîner des dommages directs aux protéines des JS et interférer avec leurs mécanismes de régulation. De plus, l’oxyde nitrique (NO) peut induire la métalloprotéinase matricielle-9 (MMP-9) impliquée dans la dégradation de ces protéines. L’endothélium vasculaire cérébral (EVC) semble être une source importante de NO dans la DT, l’expression de l’oxyde nitrique synthase endothéliale (eNOS) étant sélectivement induite dans les régions vulnérables. Le NO peut réagir avec les espèces réactives oxygénées et former du peroxynitrite, entraînant un stress oxydatif/nitrosatif endothélial. Les résultats présentés démontrent que la délétion du gène de eNOS prévient le stress oxydatif/nitrosatif cérébrovasculaire, l’extravasation des immunoglobulins G (IgGs) et l’altération de l’occludin et des ZOs dans le thalamus de souris déficientes en thiamine. De plus, cette délétion prévient l’induction de l’expression de MMP-9 dans l’EVC. Des résultats similaires ont été obtenus avec l’antioxydant N-acétylcystéine (NAC). Les mécanismes précis par lesquels les espèces réactives altèrent les protéines des JS sont inconnus. Caveolin-1, une composante majeure du caveolæ de l’EVC, est impliquée dans la régulation de l’expression des protéines des JS, et celle-ci est modulée par le stress oxydatif/nitrosatif; l’altération de l’expression de caveolin-1 a été récemment associée à la rupture de la BHE. Les résultats présentés démontrent que l’expression de caveolin-1 est sélectivement altérée dans l’EVC du thalamus de souris déficientes en thiamine, coïcidant avec la rupture de la BHE, et démontrent que la normalisation de l’expression de caveolin-1 par le NAC est associée avec l’atténuation du dommage à la BHE. Pris ensemble, ces résultats démontrent un rôle central du stress oxydatif/nitrosatif cérébrovasculaire, particulièrement celui provenant de eNOS, dans l’altération des JS de la BHE via des dommages directs et via l’induction de MMP-9 et de caveolin-1. Cette rupture de la BHE contribue par conséquent à la mort neuronale dans le thalamus, puisque la prévention des altérations cérébrovasculaires par la délétion du gène de eNOS et le NAC atténue significativement la mort neuronale. L’administration précoce d’antioxydants en combinaison avec la thiamine devrait donc être une considération importante pour le traitement du SWK. / Wernicke-Korsakoff syndrome (WKS) is a neuropsychiatric disorder caused by thiamine deficiency (TD). In experimental TD as in WKS, neuronal cell death and hemorrhages are observed in specific diencephalic and brainstem areas. Diencephalic lesions in WKS are especially severe and often lead to permanent amnesic symptoms. The link between TD-induced metabolic dysfunction and neuronal cell death is unknown. Previous reports have shown that blood-brain barrier (BBB) permeability was impaired and that this occurred prior to the onset of neuronal damage, suggesting a critical role for vascular dysfunction. Interendothelial tight junctions (TJs), the anatomical basis of the BBB, constitute a molecular network comprising occludin and zonula occludens (ZOs). This thesis shows a loss of expression and alterations in the morphology of these proteins in relation to BBB dysfunction in the thalamus of thiamine-deficient mice, providing an explanation for the presence of hemorrhages. Oxidative stress can lead to direct oxidative damage to TJ proteins and interfere with their regulation mechanisms. Also, nitric oxide (NO) can induce matrix metalloproteinase-9 (MMP-9) involved in the degradation of these proteins. Cerebral vascular endothelium (CVE) seems to be an important source of NO in TD, since endothelial nitric oxide synthase (eNOS) expression is selectively induced in vulnerable areas. NO can react with reactive oxygen species and form peroxynitrite, leading to endothelial oxidative/nitrosative stress. Results have show that eNOS gene deletion prevents cerebrovascular oxidative/nitrosative stress, immunoglobulins G (IgGs) extravasation and occludin and ZOs alterations in the thalamus of thiamine-deficient mice. Also, eNOS gene deletion prevents the induction of MMP-9 in CVE. Similar results have been obtained with the antioxidant N-acetylcysteine (NAC). Precise mechanisms by which reactive species alter TJ proteins are unknown. Caveolin-1, a major component of CVE caveolæ, is involved in the regulation of TJ protein expression, and is modulated by oxidative/nitrosative stress; alteration in caveolin-1 expression has been recently associated with BBB breakdown. The present results show that caveolin-1 expression is selectively altered in CVE of the thalamus of thiamine-deficient mice, and show that normalization of caveolin-1 expression by NAC is associated with the attenuation of BBB damage. Taken together, these results demonstrate a central role for cerebrovascular oxidative/nitrosative stress, especially coming from eNOS, in BBB TJ protein alterations via direct damage and via induction of MMP-9 and caveolin-1. As a result, BBB breakdown contributes to neuronal cell death in the thalamus, since prevention of cerebrovascular alterations by eNOS gene deletion and NAC significantly attenuates neuronal cell death. Early administration of antioxidants combined with thiamine should therefore be an important consideration for the treatment of WKS.
58

Análise de um painel de biomarcadores urinários para identificar e prever recidivas de carcinoma urotelial superficial de bexiga / Analysis of panel urinary biomarkers to identify and predict recurrence of superficial bladder urothelial carcinoma

Srougi, Victor 18 January 2019 (has links)
Introdução: O seguimento de pacientes com câncer de bexiga superficial apresenta embargos financeiros e psicológicos ao paciente, devido à realização frequente de exames invasivos. Com fim de substituir ou diminuir os exames invasivos, busca-se biomarcadores urinários acurados, que permitam diagnosticar a recidiva tumoral e estratificar pacientes com maior risco de recidiva futura. O objetivo deste estudo é avaliar se expressão na urina de PAI-1, DJ-1, ApoA-1, MMP-9 e IL-8 permite identificar e antecipar a recidiva de câncer de bexiga. Método: A expressão da PAI-1, DJ-1, ApoA-1, MMP-9 e IL-8 foi mensurada por ELISA na urina de 152 pacientes tratados previamente de carcinoma urotelial superficial de bexiga e em seguimento. Os níveis das proteínas foram comparados entre pacientes com e sem recidiva de câncer de bexiga (1) no momento da coleta de urina e (2) durante o seguimento. A ocorrência de recidiva tumoral foi confirmada por análise histopatológica da biópsia de lesões suspeitas, investigadas quando havia alterações na cistoscopia, ultrassom ou citologia oncótica. Pacientes com recidiva diagnosticada no momento da coleta de urina foram excluídos da análise para avaliar o papel antecipatório das cinco proteínas. Foi avaliado se o uso prévio de BCG intra-vesical exercia influência no nível das cinco proteínas estudadas. Resultados: Entre os pacientes avaliados, 16 (10,5%) apresentaram recidiva de carcinoma urotelial no momento da coleta de urina e 21 (15,4%) apresentaram recidiva de carcinoma urotelial durante o seguimento. O seguimento mediano foi de 47 meses (interquartis de 39 e 50 meses). Um painel para o diagnóstico de recidiva tumoral incluindo três biomarcadores (ApoA-1, MMP-9 e IL-8) apresentou razão de risco de 12,9 (IC 95% =3,5-47,4) e um painel para prever pacientes que desenvolverão recidiva durante o seguimento incluindo dois biomarcadores (PAI-1 e IL-8) apresentou razão de risco de 4,1 (IC 95% =1,4-11,4). Os resultados dos painéis não foram influenciados pelo uso prévio de BCG intra-vesical. Conclusão: Os painéis apresentados permitem identificar pacientes com recidiva de carcinoma urotelial de bexiga e prever quais pacientes terão maior risco de desenvolver recidiva no futuro. O uso prévio de BCG intra-vesical não alterou a expressão dos biomarcadores / Purpose: To evaluate if the urinary levels of PAI-1, DJ-1, ApoA-1, MMP-9 and IL-8 can identify and predict tumor recurrence in patients on follow-up of superficial bladder cancer. Methods: We prospectively analyzed the urine of 152 patients previously treated of superficial bladder cancer on follow-up regimen. Five biomarkers (PAI-1, DJ-1, ApoA-1, MMP-9 and IL-8) were assessed by ELISA and compared among patients with and without bladder cancer recurrence (1) in the moment of urine collection and (2) during follow-up. Tumor recurrence was evaluated with cystoscopy, ultrasound and urine oncotic cytology and confirmed by pathological analysis. Patients with recurrence at urine collection were excluded from prediction analysis. A correlation between the level of the biomarkers and previous use of intravesical BCG was investigated. Results: Median follow-up was 47 months (IQR =39-50 months). Among patients included, 16 (10,5%; N =152) and 21 (15,4%; N =136) had bladder cancer recurrence diagnosed in the moment of urine collection and during follow-up, respectively. The panel to diagnose recurrence including 3 biomarkers (ApoA-1, MMP-9 and IL-8) presented OR =12,9 (CI =3,5-47,4), while the panel to predict patients who will have a recurrence during follow-up including 2 biomarkers (PAI-1 and IL-8) presented OR =4,1 (CI =1,4- 11,4). Previous use of intra-vesical BCG didn\'t influence urine biomarkers expression. Conclusions: The 3-biomarker panel can be used to identify patients with bladder cancer recurrence. The 2-biomarker panel can be used to predict patients at greater risk of bladder cancer recurrence during follow-up. Both are reliable in patients with previous use of intravesical BCG
59

Stress oxydatif cérébrovasculaire et rupture de la barrière hémato-encéphalique dans le syndrome de Wernicke-Korsakoff expérimental

Beauchesne, Élizabeth 03 1900 (has links)
Le syndrome de Wernicke-Korsakoff (SWK) est un désordre neuropsychiatrique causé par la déficience en thiamine (DT). Dans la DT expérimentale comme dans le SWK, on observe une mort neuronale et des hémorragies dans certaines régions précises du diencéphale et du tronc cérébral. Les lésions diencéphaliques du SWK sont particulièrement sévères et entraînent souvent des séquelles amnésiques permanentes. Le lien entre la dysfonction métabolique induite par la DT et la mort neuronale n’est pas connu. Des rapports précédents ont démontré que la perméabilité de la barrière hémato-encéphalique (BHE) était altérée et ce, précédant l’apparition du dommage neuronal, suggérant un rôle critique de la dysfonction vasculaire. Les jonctions serrées (JS) interendothéliales, la base anatomique de la BHE, constituent un réseau moléculaire incluant l’occludin et les zonula occludens (ZOs). Cette thèse démontre une perte d’expression et une altération de la morphologie de ces protéines en relation avec la dysfonction de la BHE dans le thalamus de souris déficientes en thiamine, fournissant une explication pour la présence d’hémorragies. Le stress oxydatif peut entraîner des dommages directs aux protéines des JS et interférer avec leurs mécanismes de régulation. De plus, l’oxyde nitrique (NO) peut induire la métalloprotéinase matricielle-9 (MMP-9) impliquée dans la dégradation de ces protéines. L’endothélium vasculaire cérébral (EVC) semble être une source importante de NO dans la DT, l’expression de l’oxyde nitrique synthase endothéliale (eNOS) étant sélectivement induite dans les régions vulnérables. Le NO peut réagir avec les espèces réactives oxygénées et former du peroxynitrite, entraînant un stress oxydatif/nitrosatif endothélial. Les résultats présentés démontrent que la délétion du gène de eNOS prévient le stress oxydatif/nitrosatif cérébrovasculaire, l’extravasation des immunoglobulins G (IgGs) et l’altération de l’occludin et des ZOs dans le thalamus de souris déficientes en thiamine. De plus, cette délétion prévient l’induction de l’expression de MMP-9 dans l’EVC. Des résultats similaires ont été obtenus avec l’antioxydant N-acétylcystéine (NAC). Les mécanismes précis par lesquels les espèces réactives altèrent les protéines des JS sont inconnus. Caveolin-1, une composante majeure du caveolæ de l’EVC, est impliquée dans la régulation de l’expression des protéines des JS, et celle-ci est modulée par le stress oxydatif/nitrosatif; l’altération de l’expression de caveolin-1 a été récemment associée à la rupture de la BHE. Les résultats présentés démontrent que l’expression de caveolin-1 est sélectivement altérée dans l’EVC du thalamus de souris déficientes en thiamine, coïcidant avec la rupture de la BHE, et démontrent que la normalisation de l’expression de caveolin-1 par le NAC est associée avec l’atténuation du dommage à la BHE. Pris ensemble, ces résultats démontrent un rôle central du stress oxydatif/nitrosatif cérébrovasculaire, particulièrement celui provenant de eNOS, dans l’altération des JS de la BHE via des dommages directs et via l’induction de MMP-9 et de caveolin-1. Cette rupture de la BHE contribue par conséquent à la mort neuronale dans le thalamus, puisque la prévention des altérations cérébrovasculaires par la délétion du gène de eNOS et le NAC atténue significativement la mort neuronale. L’administration précoce d’antioxydants en combinaison avec la thiamine devrait donc être une considération importante pour le traitement du SWK. / Wernicke-Korsakoff syndrome (WKS) is a neuropsychiatric disorder caused by thiamine deficiency (TD). In experimental TD as in WKS, neuronal cell death and hemorrhages are observed in specific diencephalic and brainstem areas. Diencephalic lesions in WKS are especially severe and often lead to permanent amnesic symptoms. The link between TD-induced metabolic dysfunction and neuronal cell death is unknown. Previous reports have shown that blood-brain barrier (BBB) permeability was impaired and that this occurred prior to the onset of neuronal damage, suggesting a critical role for vascular dysfunction. Interendothelial tight junctions (TJs), the anatomical basis of the BBB, constitute a molecular network comprising occludin and zonula occludens (ZOs). This thesis shows a loss of expression and alterations in the morphology of these proteins in relation to BBB dysfunction in the thalamus of thiamine-deficient mice, providing an explanation for the presence of hemorrhages. Oxidative stress can lead to direct oxidative damage to TJ proteins and interfere with their regulation mechanisms. Also, nitric oxide (NO) can induce matrix metalloproteinase-9 (MMP-9) involved in the degradation of these proteins. Cerebral vascular endothelium (CVE) seems to be an important source of NO in TD, since endothelial nitric oxide synthase (eNOS) expression is selectively induced in vulnerable areas. NO can react with reactive oxygen species and form peroxynitrite, leading to endothelial oxidative/nitrosative stress. Results have show that eNOS gene deletion prevents cerebrovascular oxidative/nitrosative stress, immunoglobulins G (IgGs) extravasation and occludin and ZOs alterations in the thalamus of thiamine-deficient mice. Also, eNOS gene deletion prevents the induction of MMP-9 in CVE. Similar results have been obtained with the antioxidant N-acetylcysteine (NAC). Precise mechanisms by which reactive species alter TJ proteins are unknown. Caveolin-1, a major component of CVE caveolæ, is involved in the regulation of TJ protein expression, and is modulated by oxidative/nitrosative stress; alteration in caveolin-1 expression has been recently associated with BBB breakdown. The present results show that caveolin-1 expression is selectively altered in CVE of the thalamus of thiamine-deficient mice, and show that normalization of caveolin-1 expression by NAC is associated with the attenuation of BBB damage. Taken together, these results demonstrate a central role for cerebrovascular oxidative/nitrosative stress, especially coming from eNOS, in BBB TJ protein alterations via direct damage and via induction of MMP-9 and caveolin-1. As a result, BBB breakdown contributes to neuronal cell death in the thalamus, since prevention of cerebrovascular alterations by eNOS gene deletion and NAC significantly attenuates neuronal cell death. Early administration of antioxidants combined with thiamine should therefore be an important consideration for the treatment of WKS.
60

The prognostic role of matrix metalloproteinase-2 and -9 and their tissue inhibitor-1 and -2 in endometrial carcinoma

Honkavuori-Toivola, M. (Maria) 16 May 2014 (has links)
Abstract Endometrial carcinoma is the most common gynegologic malignancy in developed countries. Due to early symptoms, including abnormal uterine bleeding, endometrial cancer is often diagnosed at an early stage and in that case usually has a good prognosis and high cure rates. However, the nature of the disease is heterogeneous. During the last decades, the improvement in survival rates among endometrial cancer patients has not been significant, suggesting that the traditional clinicopathological factors may be inadequate to identify patients with high-risk disease. Furthermore, aggressive adjuvant treatments can be costly and very toxic. Therefore, better prognostic markers associated with biological aggressiveness of endometrial carcinoma are needed to identify the patients with high-risk disease, and to be able to select the treatment more individually. Gelatinases (MMP-2 and MMP-9) and their tissue inhibitors (TIMP-1 and TIMP-2) have been found to play a role in tumor progression. In the present work, the expression and prognostic value of MMP-2, MMP-9, TIMP-1 and TIMP-2 were assessed in endometrial carcinoma. The patient material consisted of a total of 266 women diagnosed with primary endometrial carcinoma. The tissue expression of immunoreactive proteins was examined in paraffin-embedded tumor sections by immunohistochemical staining using specific antibodies, and the pretreatment serum levels of the proteins were quantitatively measured by ELISA. Tissue MMP-2 expression associated with a worsened prognosis, whereas tissue TIMP-2 overexpression was an indicator of a favorable outcome. Furthermore, we observed a combination of strong MMP-2 and weak TIMP-2 tissue expression to identify a group of women at high risk of adverse outcome in endometrial carcinoma. Patients with negative MMP-2 immunostaining had the best prognosis, regardless of TIMP-2 staining result. In serum measurements, high preoperative TIMP-1 concentration was a prognostic indicator of unfavorable outcome. These results indicate that tissue MMP-2 and TIMP-2 as well as circulating TIMP-1 may be prognostic markers in endometrial carcinoma. Of these, tissue MMP-2 seems to be the most potent prognostic marker. Studies with larger patient materials are needed to further explore the value of these enzymes in clinical practice in endometrial cancer. / Tiivistelmä Kohdunrungon syöpä on yleisin gynekologinen maligniteetti kehittyneissä maissa. Varhaisten oireiden, kuten poikkeavan verisen vuodon, vuoksi kohdunrungon syöpä havaitaan usein varhaisessa vaiheessa, jolloin sen ennuste on hyvä. Taudin käyttäytyminen voi kuitenkin olla moninaista. Viime vuosikymmenten aikana kohdunrungon syöpään sairastuneiden ennuste ei ole merkittävästi parantunut. Vaikuttaisi siltä, että perinteiset ennustetekijät eivät ole riittävän tarkkoja ennustamaan syövän taudinkulkua. Lisäksi liitännäishoidot voivat olla kalliita, ja niihin voi liittyä vakavia haittavaikutuksia. Uusien biologisten ennustetekijöiden löytäminen olisi tärkeää, jotta aggressiivista syöpätyyppiä sairastavat potilaat pystyttäisiin tunnistamaan entistä paremmin, ja hoito kyettäisiin räätälöimään yksilöllisemmin taudinkuvaa vastaavasti. Gelatinaasien (MMP-2 ja MMP-9) sekä niiden kudosinhibiittoreiden (TIMP-1 ja TIMP-2) on havaittu osallistuvan syövän etenemiseen. Tässä tutkimuksessa tarkasteltiin MMP-2:n ja MMP-9:n sekä niiden kudosinhibiittoreiden TIMP-1:n ja TIMP-2:n ilmentymistä ja ennusteellista merkitystä kohdunrungon syövässä. Aineisto käsitti yhteensä 266 primaariseen kohdunrungon syöpään sairastunutta naista. Määritysmenetelminä käytettiin sekä immunohistokemiallista värjäystä parafiiniin valettujen kudosnäytteiden osalta että ELISA-määrityksiä ennen hoitoa otettujen seeruminäytteiden osalta. Syöpäkudoksen runsas MMP-2 -proteiinin ilmentyminen liittyi epäsuotuisaan ennusteeseen, kun taas kasvainkudoksen voimakas TIMP-2 -proteiinin ilmentyminen oli hyvän ennusteen merkki. Lisäksi kasvainkudoksen voimakkaan MMP-2- ja heikon TIMP-2 -proteiinien ilmentymisen yhdistelmän havaittiin liittyvän suurempaan syövästä johtuvaan kuolleisuuteen. MMP-2 -negatiivisten potilaiden eloonjäämisennuste oli paras, TIMP-2 -värjäystuloksesta riippumatta. Seerumin korkea TIMP-1 -pitoisuus oli merkittävä huonontuneen ennusteen merkki. Tutkimuksen tulokset viittaavat siihen, että kasvainkudoksessa esiintyvät MMP-2- ja TIMP-2 -proteiinit samoin kuin seerumin TIMP-1 -pitoisuus voivat ennustaa kohdunrungon syövän kliinistä käyttäytymistä. Kasvainkudoksessa esiintyvä MMP-2 -proteiini vaikuttaisi olevan merkittävin ennusteellinen tekijä, mutta tulosten varmistamiseksi tarvitaan lisää tutkimuksia suuremmilla potilasaineistoilla.

Page generated in 0.056 seconds