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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.
21

Caracterização dos efeitos locais e sistémicos da metaloprotease BtaHF purificada a partir do veneno total de Bothriopsis taeniata / Characterization of local and systemic effects of the metaloproteinase BtaHF purified from Bothriopsis taeniata crude venom

Huaco, Frank Denis Torres, 1979- 25 March 2013 (has links)
Orientador: Sergio Marangoni / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-22T17:42:51Z (GMT). No. of bitstreams: 1 Huaco_FrankDenisTorres_D.pdf: 4738657 bytes, checksum: 14194646f90e694d6d1598ef9b7fc870 (MD5) Previous issue date: 2013 / Resumo: Neste trabalho descrevemos a purificação, caracterização estrutural e os efeitos locais e sistêmicos de uma nova metaloprotease de baixa massa molecular, denominada BtaHF (Bothriopsis taeniata Hemorrhagic Factor). A proteína foi purificada a partir do veneno total da serpente Bothriopsis taeniata usando cromatografía exclusão molecular convencional (Sephadex G-75), seguida de uma cromatografia de alta eficiência de troca iônica (coluna DEAE 8HR APMinicolumn). A nova metaloprotease BtaHF apresenta um alto grau de pureza e homogeneidade molecular e possui uma massa molecular de 25968,16 Da. A BtaHF apresentou atividade caseinolítica com uma temperatura e pH ótimos de 37-40 oC e 8, respectivamente. A atividade caseinolítica da BtaHF foi inibida por EGTA, EDTA e DTT, mas os inibidores PMSF e SBTI não apresentaram efeito. O íon Ca+2 é importante para a estabilidade da metaloprotease BaHF, aumentando atividade caseinolítica da enzima, entretanto, os íons Zn+2 e Mn+2 inibem a atividade enzimática desta enzima. A BtaHF é uma enzima ?-fibrinogênolítica por degradar rapidamente à cadeia A do fibrinogênio após 15 minutos de incubação, enquanto a cadeia B? é completamente degradada após 6 horas. Por outro lado, a BtaHF não possui atividade fibrinolítica ou arginine amidase. A análise de composição de aminoácidos mostrou que a BtaHF possui caráter ácido e apresenta 6 resíduos de cisteína. No estudo de homologia a BtaHF apresentou maior identidade sequencial com metaloproteases com atividade hemorrágica da classe P-I como a BaP1 (Bothrops asper). A metaloprotease BtaHF possui atividade hemorrágica fraca com uma dose hemorrágica mínima de 20,14 ?g/animal. Esta metaloprotease mostrou atividade edematogênica que mostrou ser dose-dependente e teve um efeito permaneceu após 6 horas de injeção. Ambos os efeitos estão relacionados à atividade proteolítica e ao correto enovelamento da BtaHF, una vez que foram inibidas por agentes quelantes (EDTA e EGTA) e redutor (DTT). A metaloprotease BtaHF não possui atividade miotóxica, embora tenha atividade citotóxica em fibroblastos C2C12. A análise histológica do músculo gastrocnêmio de camundongo confirmou a atividade hemorrágica e edematogênica da metaloprotease, assim como, a ausência de atividade miotoxica. A metaloprotease BtaHF produz efeitos sistêmicos específicos quando injetado via endovenosa em camundongos. A nível do tecido pulmonar, a toxina produz alteração da estrutura alveolar com hemorragia significativa, engrossamento dos septos alveolares e inflamação. A BtaHF não produz hemorragia no tecido renal, mas alterou a estrutura glomerular, além de alterações no citoplasma das células dos túbulos proximal e distal. Contrariamente, esta toxina não produz efeito nenhum a nível hepático. A BtaHF consome o fibrinogênio plasmático de modo dose e tempo-dependente, produzindo incoagulabilidade sanguínea após uma hora. Estudos in vitro revelaram atividade pro-coagulante dose-dependente, ao reduzir os índices PT e APPT. A utilização de metodologias de purificação de alta eficiência permitram a purificação da metaloprotease BtaHF. Assim, esta abordagem pode ser aplicada nos estudos bioquímicos, estrutura-função, fisiológicos e farmacológicos, podendo deduzir o papel desenvolvido pela metaloprotease purificada nos efeitos biológicos produzidos pelo veneno total de Botriopsis taeniata. As informações produzidas no presente trabalho permitiram sugerir que as principais funções das metaloproteases de veneno de serpente da classe P-I são manter a hemorragia característica dos envenenamentos botrópicos e participar da imobilização da presa promovendo rápidos efeitos próinflamatórios / Abstract: In this work we described the purification, structural characterization and the local and systemic effects of a new low molecular weight snake venom metalloproteinase, named BtaHF. This protein was purified from the Bothriopsis taeniata crude venom combining conventional molecular exclusion (Sephadex G-75 column) followed by an ion exchange (DEAE 8HR APMinicolumn) chromatography on a HPLC system. The new metalloproteinase BtaHF showed a high degree of purity and molecular homogeneity with a molecular mass of 25968.16 Da. BtaHF showed caseinolytic activity with an optimum temperature and pH of 37-40 °C and 8, respectively. The caseinolytic activity was inhibited by EGTA, EDTA and DTT, but PMSF and SBT-I did not show inhibitory effect. The Ca+2 ion shown to be important for protein stability enhancing its caseinolytic activity, on the contrary, Z+2 and Mn+2 showed inhibitory effects upon the enzymatic activity of this protein. The metalloproteinase BtaHF is an ?-fibrigenolytic enzyme, rapidly degraded fibrinogen A? chain within 15 minutes, while fibrinogen B? chain is degraded after 6 hours. This enzyme did not show fibrinolytic or arginine amidase activities BtaHF is an acidic protein due the mayor proportion of acidic amino acid in its amino acid composition with 6 cysteinyl residues. By the homology study BtaHF share a high sequence identity other weakly hemorrhagic P-I class SVMP such BaP1 isolated from Bothrops asper snake venom This new metalloproteinase, BtaHF, have a weak hemorrhagic with a minimum hemorrhagic dose of 20.14 ?g. Also, this metalloproteinase showed dose-dependent paw edemaforming activity, this effect remain six hours after inoculation. Both hemorrhage and edemaforming activities were related to the enzymatic activity and correct fold of BtaHF, since chelating (EDTA and EGTA) and reducing (DTT) agents inhibited these activities. On the other hand, this enzyme did not show miotoxic activity, although, showed citotoxic activity on C2C12 fibroblast. Histological analysis of mice gastrocnemius muscle confirmed that the metalloproteinase produce local hemorrhage and pro-inflammatory effects, as well as, the absence of miotoxic activity. This metalloproteinase, BtaHF, produce specific systemic effects when injected endovenously in mice. On lung tissue level these toxin produce alteration of alveolus structure with significant hemorrhage, thickness of alveolus septum and inflammation. On renal tissue BtaHF did not produce hemorrhage, but, was observe alteration of glomerulus structure, along with cytoplasmatic alterations of distal and proximal tubulus cells. On the other hand, were not observed any alterations on hepatic tissue. BtaHF deplete completely plasma fibrinogen levels in a time and dose-depended manner, reaching blood incoagulability after one hour. BtaHF shown dose-dependent pro-coagulant activity "ex vivo" reducing PT and APPT index. The metalloproteinase BtaHF was purified using a high efficient system. Thus, this approach can be applied to biochemical, structure-function, physiologic and pharmacologyc studies which allow infer the role of this enzyme in the biological effects produce by Bothriopsis taeniata crude venom. The information here presented suggest that the mainly functions of P-I class snake venom metalloproteinases are the maintenance of the characteristic hemorrhagic effect of the botropic venoms and participate of prey immobilization by promoting rapid inflammatory effects / Doutorado / Bioquimica / Doutor em Biologia Funcional e Molecular
22

Matrix degrading proteases and collagen-derived angiogenesis inhibitors in the regulation of carcinoma cell growth

Nyberg, P. (Pia) 05 April 2005 (has links)
Abstract Cancer progression is a complex multi-step process. Two critical steps in tumor growth and invasion are the proteolytic processing of the extracellular matrix environment and the angiogenic switch enabling blood supply into the tumor. Matrix metalloproteases (MMPs) are a group of proteolytic enzymes involved in physiological and pathological extracellular matrix processing. Trypsinogen, a serine protease, is one of the first proteolytic enzymes characterized. The amount of one of its isoforms, tumor associated trypsinogen-2 (TAT-2) correlates with the malignant phenotype of several forms of cancers. Both of these protease groups are critically dependent on their activation from latent proforms to fully active enzymes. We found that the overproduction of TAT-2 in malignant oral squamous cell carcinoma cell line was associated with elevated proMMP-9 (but not proMMP-2) activation, as well as enhanced cancer cell intravasation in an in vivo model. This indicates that TAT-2 and MMP-9 activation play a role in the invasive growth of oral carcinomas. Proteases are involved in angiogenesis, the formation of new blood vessels, in several ways. One mechanism is the release of cryptic anti-angiogenic molecules from larger extracellular matrix components. Endostatin is one such cryptic endogenous inhibitor of angiogenesis. Certain MMPs were able to cleave endostatin from its parent molecule, collagen XVIII. The endostatin fragments generated by MMP-3, -7, -9, -13 and -20 inhibited angiogenesis in a similar fashion as the native endostatin. The regulation between MMPs and endostatin was shown to be reciprocal, as endostatin was able to block the activation and activities of MMP-2, -9 and -13. The inhibition of these tumor-associated MMPs explains at least in part the anti-tumor activity of endostatin. Endostatin not only affects endothelial cell growth as is usually thought, but it also inhibits the migration of oral carcinoma cells. In addition, cell density and proper concentration were proven to be critical for the activity of endostatin. Arresten is another endogenous inhibitor of angiogenesis and tumor growth derived from type IV collagen. We confirmed that arresten binds to integrin α1β1 on endothelial cell surface. We found that this binding is functionally significant for the anti-angiogenic properties of arresten, as tumors planted to integrin α1 knockout mice or endothelial cells derived from those mice did not respond to arresten treatment.
23

Synthesis, characterization and matrix metalloproteinase inhibition of doxycycline modified dental adhesives

Palasuk, Jadesada January 2015 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The biodegradation of the hybrid layer of dental restorations is due in part to the degradation of the demineralized collagen by matrix metalloproteinases (MMPs). During the bonding procedure, phosphoric acid/acidic primers activate MMPs that degrade denuded type I collagen. As a result, the hybrid layer loses its integrity overtime, leading to the failure of the resin composite restoration. This study aimed to evaluate doxycycline (DOX) for its effects on preventing the degradation of the hybrid layer through the modification of the dental adhesive with aluminosilicate clay nanotubes (HNT) loaded with doxycycline. Doxycycline was encapsulated into HNT at three distinct concentrations (10%, 20% and 30% DOX, w/v). The increases in the concentration of doxycycline significantly increased the amount of doxycycline that was encapsulated into HNT and the drug loading into the HNT. Conversely, the encapsulation efficiency was significantly decreased with the increases in concentration of doxycycline. The modified adhesives were fabricated by incorporation of DOX-encapsulated HNT into a commercially available dental adhesive (Adper Scotchbond Multi-Purpose, SBMP). The degree of conversion (DC), Knoop microhardness, doxycycline release profiles, the biological activity (antibacterial and anti-MMP activity), and cytocompatibility of the modified adhesives were investigated. There were no statistically significant differences (p > 0.05) in DC and Knoop microhardness compared to the control (SBMP). None of the adhesive eluates was cytotoxic to the human dental pulp stem cells. Although higher concentrations of doxycycline led to a higher release of doxycycline from the modified adhesives, the differences were not significant (p = 0.259) among the groups (10%, 20% and 30% DOX). A significant growth inhibition of S. mutans and L. casei by direct contact illustrated successful encapsulation of doxycycline into the modified adhesives. Doxycycline released from the modified adhesives did not inhibit the growth of both cariogenic bacteria but inhibited MMP-1 activity. The results suggested that subantimicrobial levels of doxycycline were gradually released. The immediate microtensile bond strengths were not significantly different from those of the control (SBMP), suggesting no negative effect of doxycycline on dentin bonding (only 10% DOX were investigated). The long-term resin-dentin bond durability should be evaluated.
24

Lim Kinase 1 Modulates Expression Of Matrix Metalloproteinases And Associates With Gamma-tubulin: Dual Role In Invasion And Mito

Tapia, Tenekua 01 January 2007 (has links)
LIM kinase 1 (LIMK1) is a unique dual specificity serine/threonine kinase containing two N-terminal LIM domains in tandem, a PDZ domain and a C-terminal catalytic domain. LIMK1 is involved in modulation of actin cytoskeleton through inactivating phosphorylation of the ADF (actin depolymerization factor) family protein cofilin. Recent studies have shown that LIMK1 is upregulated in breast and prostate cancer cells and tissues, promotes metastasis in animals and induces acquisition of an invasive phenotype when ectopically expressed in benign prostate epithelial (BPH) cells. Furthermore, overexpression of LIMK1 was associated with altered sub cellular localization of the membrane type 1 matrix metalloprotease (MT1-MMP). Matrix metalloproteases (MMPs) are a family of zinc dependant proteolytic enzymes that hydrolyze extra cellular matrix and cell surface molecules. A number of MMPs including MMP-2, MMP-9 and their activator MT1-MMP are over expressed in a variety of cancers including prostate cancer. The abundant expression of these enzymes contributes to changes in the tumor microenvironment, which facilitate degradation of the surrounding collagen matrix and migration of cells through the matrix defects. In this study, we show that MMPs are involved in LIMK1 induced invasion of otherwise non-invasive BPH cells. We also show that (a) the kinase activity of LIMK is not essential for the invasive behavior of the cells and (b) the absence of LIM domains significantly retards cell invasion. We have established transfected sub lines of BPH cells stably expressing 1) constitutively active LIMK1 (BPHLCA), 2) kinase dead LIMK1 (BPHLKD) and 3) only the kinase domain of LIMK1 (BPHLK) for our study. In vitro invasion assays revealed that LIMK1 induced invasion was inhibited by the MMP specific inhibitor, GM6001, and that cells expressing kinase-dead LIMK1 were equally invasive. Furthermore, BPH cells expressing LIMK1 mutants expressed higher amounts of MMP-2 and MMP-9. Substrate zymography revealed increased concentration of secreted MMP-2 and MMP-9 in the media of BPHLCA and BPHLK cells respectively compared to BPHV (vector control) cells. Quantitative RT-PCR also showed a ~10 fold increase in the steady state concentration of MMP-2 in BPHLCA cells compared to the control BPHLV cells. Expression of active LIMK1 stimulated cell-surface expression of MT1-MMP in BPHLCA cells as determined by flow cytometry. A modest increase in expression of MT1-MMP was noted in BPHLKD cells compared to BPHLK and BPHV cells. Immunoflourescence analysis indicated differential localization of MT1-MMP and LIMK1 in BPH cells expressing different mutants of LIMK1. Co-localization of LIMK1 and MT1-MMP in the plasma membrane and in the perinuclear region was also evident in these cells. Furthermore, here we provide evidence that suggests a functional role for phosphorylated (activated) LIMK1/2 (p-LIMK1/2) during mitosis through its association with γ-tubulin. Immunoflourescence analysis showed distinct co-localization of γ -tubulin and p-LIMK1/2 in the centrosomes during mitosis from early prophase to the beginning of telophase. No association was seen in the interphase or in late telophase. Phospho-LIMK1/2 was co-precipitated in immunoprecipitates of γ -tubulin using an anti- γ -tubulin antibody suggesting a physical association between these proteins in a complex. This finding reveals a novel role of LIMK1 in the mitotic process. In summary, our data suggests that MMPs are involved in LIMK1 induced invasion of prostate epithelial cells, and that this effect is mediated through altered expression and activation of specific MMPs. Furthermore, LIMK1 induced invasion is dependant on the presence of LIM domains more than the kinase activity. Finally, we show that phosphorylated LIMK1 and LIMK2 are involved in the mitotic process in a stage specific manner through its association with the centrosomal protein γ -tubulin. Because LIMK1 promotes invasion in vitro, regulates expression of MMPs, and is involved in mitotic processes, it is an attractive drug target for prostate cancer therapy.
25

Influence d'un phosphate de calcium substitué en strontium sur la physiologie de l'ostéoblaste humain en culture et évaluation de son potentiel de réparation osseusse chez la souris / Strontium substituted calcium phosphate influence on human osteoblasts physiology and evaluation of his potential bone healing capability on a mouse model.

Braux, Julien 02 February 2011 (has links)
Les phosphates de calcium sont des biomatériaux couramment utilisés dans de nombreuses spécialités médicales. L'amélioration de ces biomatériaux vise à augmenter leur ostéointégration et leur bioactivité. Le strontium possédant d'intéressantes capacités de modification de la physiologie osseuse, l'incorporation de ce dernier au sein de phosphates de calcium par substitution ionique pourrait permettre un déplacement de la balance osseuse vers la formation osseuse.Notre travail a permis de démontrer la capacité des particules de phosphates de calcium substitués en strontium à augmenter la prolifération des ostéoblastes en culture et à modifier l'expression et la synthèse des principales protéines impliquées dans la physiologie osseuse (Collagène de type I, Serpine H1, métalloprotéinases matricielles 1 et 2, inhibiteurs tissulaires des MMPs). Par ailleurs, la poudre de phosphates de calcium ne contenant pas de strontium a entrainé une sécrétion accrue de chimiokines pro-inflammatoires (MCP-1 et GRO-?) qui n'a pas été observée pour la poudre substituée. Enfin, des études in-vivo réalisées dans un modèle de défaut osseux murin a permis de démontrer une plus grande résorbabilité de la poudre contenant du strontium et sa plus grande capacité à stimuler la réparation osseuse. / Calcium phosphate are widely used in medicine. Their upgrade tend to enhance their biocompatibility and their bioactivity. Strontium has interesting capability to modify the bone physiologie. Its incorporation in calcium phosphates could lead to modify the bone balance toward osteogenesis.The present work reveal the capacities of such biomaterials to enhance the replication of osteoblasts ant to modify the expression and the synthesis of proteins implicated in the bone balance (type I collagen, serpinH1, Matrix metalloproteinases 1 and 2, tissular inhibitors of MMPs). Moreover, non substituted calcium phosphate powders enhance the expression and synthesis of inflammatory cytokines (MCP-1 and Gro-a). This fact was not observed with the non substituted powder. In-vivo studies on a mouse model permit us to demonstrate the higher resorbability and the higher bone healing capability of the substituted powder.
26

Os efeitos da radiação ionizante nas proteínas endógenas da dentina / The effects of ionizing radiation on dentin endogenous proteases

Cunha, Sandra Ribeiro de Barros da 18 January 2019 (has links)
A radioterapia é um dos principais tratamentos para pacientes com câncer de cabeça e pescoço e a cárie relacionada à radioterapia é um de seus efeitos colaterais, apresentando-se com alta taxa de ocorrência. Além disso, falhas precoces em restaurações realizadas em dentes de pacientes irradiados em cabeça e pescoço também são observadas. Como a degradação enzimática do colágeno ocorre principalmente através da atividade das metaloproteinases de matriz e das cisteínacatepsinas, o objetivo deste estudo foi avaliar a atividade enzimática da dentina hígida e restaurada de dentes submetidos à radioterapia in vivo e in vitro. Os dentes irradiados in vivo foram extraídos de pacientes submetidos à radioterapia com uma dose cumulativa que variou de 40 a 70 Gy. As extrações foram feitas de 3 a 12 meses após a RT devido a doenças periodontais. Para os dentes irradiados in vitro, as amostras foram submersas em água destilada com uma irradiação total e única de 70 Gy. O estudo foi dividido em 2 fases independentes: Fase 1: Dentina Não-Restaurada (avaliação de amostras não irradiadas, dentes submetidos à radioterapia in vitro e in situ). Fase 2: Dentina Restaurada (avaliação de amostras não irradiadas e dentes submetidos à radioterapia in vitro) com 3 adesivos. Para o ensaio de zimografia (fase 1), os grupos irradiados in vitro, in vivo e não irradiados foram divididos em dois subgrupos: 1) mineralizado; 2) desmineralizado com ácido fosfórico10%. As proteínas dentinárias foram extraídas e submetidas à análise zimográfica de acordo com Mazzoni et al., 2007. Para a zimografia in situ (fase 2), os espécimes foram divididos em 6 grupos, de acordo com a forma de irradiação (não irradiada e irradiada in vitro) e o sistema adesivo testado (Adper Single Bond, 3M ESPE, ClearFil SE Bond, Kuraray ou Scotchbond Universal, 3M ESPE). Uma gelatina conjugada com fluoresceína autoextinguível foi usada como substrato para as proteases endógenas. A atividade enzimática gelatinolítica foi observada em microscópio confocal (Zeiss LSM 780-NLO, Carl Zeiss Microscopy GmbH). Para a análise da microscopia eletrônica de varredura, amostras restauradas e hígidas foram submetidas a técnica de pré-imunomarcação usando anticorpo monoclonal primário anti-CT-K e anti-CT-B, e anticorpo secundário conjugado com nano-partículas de ouro de 15nm. Um aumento na atividade gelatinolítica pós radioterapia para ambos os substratos (dentina restaurada e hígida) pôde ser observada. Houve uma maior expressão das formas ativas das MMP-2 e MMP-9 pós radioterapia para ambas as formas de radioterapia em dentina não restaurada. Nenhuma diferença na imuno-marcação para CT-K e CT-B entre os grupos irradiados e não irradiados foi observada. Adesivos autocondicionantes apresentaram uma imuno-marcação mais fraca para CT-K quando comparado ao adesivo de condicionamento total. Com isso, pode-se concluir que a radiação ionizante foi capaz de influenciar a atividade enzimática das proteínas endógenas da dentina restaurada e não restaurada. Palavras-chave: Radioterapia, metaloproteinases de matriz, MMP, cisteinocatepsinas, CT, Cárie relacionada à radiação. / Radiotherapy is one of the main treatments for head and neck cancer patients. Radiation-related caries and early restorations failures are side-effects with high rate of recurrence. As enzymatic degradation of collagen occurs mainly through the activity of matrix metalloproteinases (MMPs) and cysteine-cathepsins (CTs), the objective of this study was to evaluate the influence of in vivo and in vitro radiotherapy on endogenous proteases of the restored and non-restored dentin. In vivo irradiated teeth were extracted from patients who underwent clinical radiation protocols with a cumulative dose of radiation that ranged from 40 to 70 Gy. Extractions were performed 3 to 12 months after radiotherapy conclusion due to periodontal reasons. For the in vitro irradiated teeth, samples were submerged in distilled water with a total and single irradiation dose of 70 Gy. For gelatin zymography assay, irradiated in vivo, in vitro and non-irradiated groups were divided in two subgroups: 1) mineralized or 2) demineralized with 10% phosphoric acid. Dentin proteins were extracted and submitted to zymographic analysis in accordance to Mazzoni et al., 2007. For in situ zymography, specimens were divided into 6 groups, according to its irradiation form (non-irradiated and irradiated in vitro) and the adhesive system tested (Adper Single Bond, 3M ESPE, ClearFil SE Bond, Kuraray or Scotchbond Universal, 3M ESPE) using a self-quenched fluorescein-conjugated gelatin as the endogenous proteases substrate. The endogenous gelatinolytic enzyme activity was assessed by confocal laser-scanning microscope (Zeiss LSM 780-NLO, Carl Zeiss Microscopy GmbH). For SEM analysis of the HL, restored specimens were submitted to a pre-embedding immunolabeling technique using primary monoclonal antibody anti-CT-K and anti-CTB and a secondary antibody conjugated with 15nm gold nanoparticles. Radiotherapy groups presented increased gelatinolytic activity on both restored and non-restored dentin. MMP-2 and MMP-9 active form presented higher expression on both irradiated groups for non-restored dentin. Labeling for CT-K and CT-B did not differ from irradiated to non-irradiated groups. SE adhesives presenter weaker labeling for CT-K when compared to the E&R adhesive. Herewith, ionizing radiation may be able to influence the enzymatic activity of the endogenous proteins of restored and unrestored dentin
27

Estudo de atividades amidásicas na linhagem MN7 de Photorhabdus luminescens luminescens, isolada da linhagem LPP7 de Heterorhabditis baujardi. / Study of amidasic activities present in Photorhabdus luminescens luminescens strain MN7, isolated from Heterorhabditis baujardi strain LPP7.

Neves, Maira Rodrigues de Camargo 27 August 2014 (has links)
Photorhabdus é um gênero de enterobactérias simbiontes de Heterorhabditis, um gênero de nematoides entomopatogênicos. Dentre as enzimas secretadas por P. luminescens TTO1, destaca-se PrtA, uma metaloprotease que pertence a subfamília das serralisinas. PrtS, uma protease capaz de induzir uma forte resposta de melanização no inseto, foi identificada em P. temperata Az29 mas não em P. luminescens TTO1. Neste trabalho foram detectadas e caracterizadas bioquimicamente algumas proteases secretadas pelo isolado MN7 de P. luminescens luminescens. Foram detectadas duas atividades mais proeminentes: uma de 50 kDa, e outra de 38 kDa. Com o sequenciamento do genoma desta bactéria, pudemos confirmar a presença no genoma de genes codificando proteínas de alta identidade com as descritas PrtA e PrtS, de massas similares às detectadas nas nossas zimografias. As proteases são inibidas por inibidores específicos de metaloproteases. P. luminescens MN7 apresenta secreção, portanto, de uma protease já descrita algumas vezes, e de outra presente apenas em P. temperata Az29. / Photorhabdus is a genus of Enterobacteriaceae, symbionts of Heterorhabditis, a genus of entomopathogenic nematodes. Among the enzymes secreted by P. luminescens TTO1 stands out PrtA, a metalloprotease that belongs to the subfamily of serralysins. PrtS, a protease capable of inducing a strong melanotic response from the insect, was identified in P. temperata Az29 but not in P. luminescens TTO1. In this work were detected and characterized biochemically few isolated proteases secreted by P. luminescens luminescens MN7. Two most prominent activities were detected: one with 50 kDa and one with 38 kDa. With the sequencing of the genome of MN7, we could confirm the presence in the genome of genes encoding proteins with high identity to PrtA and PrtS already described, with similar masses to those detected in our zimographies. These proteases are inhibited by specific inhibitors of metalloproteases. P. luminescens MN7 secretes a protease already described a few times, and other present only in P. temperata Az29.
28

Efeito da solução hipertônica (NaCI 7,5%) no estresse oxidativo e nos processos de morte celular e remodelamento tecidual hepático em pancreatite aguda experimental / Effect of hypertonic saline solution (NaCl 7.5%) on oxidative stress, apoptosis and hepatic tissue remodeling during acute pancreatitis

Rios, Ester Correia Sarmento 08 April 2010 (has links)
Lesão hepática é uma das complicações decorrentes de pancreatite aguda (PA) e mostra uma correlação positiva com a gravidade da doença. Recentemente foi demonstrado que tratamento com solução hipertônica (SH) reduz inflamação e mortalidade na PA. O presente trabalho investigou os efeitos de SH na modulação do estresse oxidativo, apoptose e remodelamento tecidual no fígado durante a PA. Ratos machos foram divididos em quatro grupos: C animais que não foram submetidos à PA ou tratamento; past animais submetidos à indução de PA e que não receberam tratamento; pas animais submetidos à PA e tratados com solução fisiológica (NaCl 0.9%); pah animais submetidos à indução de PA e que receberam SH (NaCl 7.5%). PA foi induzida pela injeção retrógrada de ácido taurocólico (2.5%) no ducto bilo-pancreático. Após 4, 12 e 24 horas os animais foram sacrificados para coleta das amostras de interesse (fígado e plasma) submetidas a ensaios para análise de expressão (western blot e PCR) de Óxido Nítrico Sintase induzível (iNOS), metaloproteinases (MMP) -2 e -9, Heat Schock Protein (HSP) 47, 60, 70 e 90, colágenos tipos I e III, caspases 2 e 9, APAF-1 e AIF, formação de nitrotirosina (imunohistoquímica), peroxidação lipídica (TBARs), atividade de alaninoaminotransferase (ALT), produção de nitrito/nitrato (Reação de Griess) e das citocinas TNF-, IL-1, IL-6 e IL-10 (ELISA). O tratamento com SH reduziu significantemente o estresse oxidativo hepático com a redução da expressão gênica de iNOS (p<0,01 vs. pas), dos níveis de nitrito/nitrato (P<0,01 vs. pas), liberação de ALT (p<0,01 vs. pas) e inibição da formação de peroxinitrito após 12 horas da indução de PA. Conseqüentemente, a expressão de HSP70 não foi ativada devido à proteção hepática causada pela administração de SH. A expressão e atividade de MMP-9 aumentaram significativamente nos grupos pas e past, entretanto o tratamento com SH manteve os níveis basais (p<0,05 vs. past, pas). Aumento da expressão de HSP47 e alterações na expressão de colágeno indicaram intenso remodelamento de matriz extracelular nos grupos não tratados ou tratados com solução fisiológica, permanecendo semelhante ao controle no grupo pah. Não ocorreram mudanças significativas na expressão das proteínas envolvidas no processo apoptótico. A SH diminui o estresse oxidativo no período crítico da PA, resultando na diminuição da lesão hepática e do remodelamento tecidual, mantendo dessa forma a integridade de matriz extracelular / It has been shown an hepatic injury following pancreatitis and a positive correlation with severity of the disease. Hypertonic Solution (HS) reduced morbidity and mortality in experimental pancreatitis. We hypothesize that hypertonic solution resuscitation of acute pancreatitis (AP) may exert antiinflammatory effects by modulating hepatic oxidative stress, apoptosis and matrix extracellular remodeling in liver. Wistar rats were divided in four groups: C- control animals not subjected to insult or treatment; NT- subjected to pancreatitis induction and receiving no treatment; NS- subjected to pancreatitis induction and receiving normal saline (0.9% NaCl); HSsubjected to pancreatitis induction and receiving hypertonic saline (7.5% NaCl). AP was induced by retrograde infusion of 2,5% sodium taurocholate into the pancreatic duct transduodenally. At 4, 12 and 24 h following pancreatitis induction, liver tissue samples were assayed in order to analyse expression of metalloproteinases (MMPs) -2 and -9, iNOS, collagens (type I and III), Heat Shock Proteins (HSPs) 47, 60, 70 and 90, caspases -2 and -7, APAF-1 and AIF, production of the cytokines TNF-, IL-1, IL-6 and IL-10, Nitrite/nitrate and ALT, Lipid peroxidation and formation of Nytrotirosine. Hypertonic solution resuscitation significantly modulates the oxidative stress in liver by reduction of iNOS gene expression (p<0,01 vs. NS), nitrite and nitrate levels (p<0,01 vs. NS), lipid peroxidation (p<0,05 vs. NT), ALT release (p<0,01 vs. NS) and peroxinitrite inhibition after 12 hours of pancreatitis induction. Consequently, the HSP70 production has not been activated due to the hypertonic solution effect in hepatic protection. At 4 h and 12 h, MMP-9 expression and activity increased in the NS and NT groups, although remaining at basal levels in the HS group (p<0.05 vs. past, pas). At 12 h, MMP-2 expression increased in the NS group (p<0.05 vs. c) but not in the HS group. At 4 h after pancreatitis induction, HSP47 expression increased in the NS and NT groups. Greater extracellular matrix remodelling occurred in the NS and NT groups than in the HS group, probably as a result of the hepatic wound-healing response to repeated injury. However, the collagen content in hepatic tissue remained at basal levels in the HS group. The proteins involved in apoptosis remained unchanged in all groups. Hypertonic saline is hepatoprotective, since it decreases oxidative stress in the critical time resulting in diminished liver damage, reducing hepatic remodelling, maintaining the integrity of the hepatic extracellular matrix during pancreatitis. Hypertonic saline-mediated regulation of MMP expression might have clinical relevance in pancreatitis-associated liver injury
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Características clínicas, patológicas e imuno-histoquímicas de pacientes com câncer de mama operável : a experiência do serviço de mastologia do Hospital de Clínicas de Porto Alegre (1999-2004)

Jobim, Flávio Cabreira January 2013 (has links)
Introdução: A Organização Mundial da Saúde estimou para o ano de 2008 aproximadamente 1.38 milhões de casos novos de câncer de mama no mundo e 458 mil mortes. A maioria dos casos (56%) e das mortes (64%), ocorrendo em países economicamente desenvolvidos. Apesar dos avanços e do diagnostico precoce, um número significativo de mulheres com tumores da mama operáveis apresentando evolução desfavorável vêm à sucumbir devido ao surgimento de doença metastática. Uma melhor compreensão da heterogeneidade do tumor e das características microambientais subjacentes, bem como dos mecanismos e as consequências das suas interações é essencial para melhorar o direcionamento das terapias existentes e desenvolver novos agentes terapêuticos para o câncer. Objetivos: Descrever as características clínicas, anatomopatológicas e imuno-histoquímicas de um grupo de pacientes com câncer de mama operável, e estudar o impacto destas características no estadiamento da doença, sobrevivência livre de recorrência e sobrevivência global. Além disto, analisar as potenciais correlações existentes entre estas características. Métodos: Estudo de coorte retrospectiva de base hospitalar envolvendo 86 mulheres com câncer primário de mama, submetidas a tratamento entre julho de 1999 e dezembro de 2004, no Serviço de Mastologia do Hospital de Clinicas de Porto Alegre. Dados clinicopatológicos e imuno-histoquimicos (RE, RP, HER2, Ki67 e p53) foram coletados dos registros hospitalares. Expressão do VEGF, MMP-2, MMP-9, TIMP-1 e TIMP-2 foram analisadas através de imuno-histoquimica. Variáveis contínuas foram analisadas pelo coeficiente de correlação de Spearman, ou pelo teste não paramétrico U de Mann-Whitney e H de Kruskal-Wallis, quando comparadas com variáveis categóricas. Variáveis categóricas foram analisadas pelo teste 2 de Pearson. Estimativas da probabilidade de sobrevivência foram obtidas pelo estimador não paramétrico de Kaplan-Meier e pelo semiparamétrico modelo de regressão de Cox. Comparação entre as curvas de sobrevivência foi realizada pelo teste estatístico de log-rank. O IC foi calculado em 95% e valores p< 0,05 foram considerados estatisticamente significativos. Resultados: A sobrevivência livre de recorrência em 5 e 10 anos foi de 82,2% e 68%, e a global foi de 90,2% e 82,9%, respectivamente. Número de linfonodos positivos (p= 0,00; p= 0,03), diâmetro tumoral (p= 0,01; p= 0,01) e estádio (p= 0,00; p= 0,02) são fatores de risco isolado para recorrência e óbito, respectivamente. Superexpressão de HER2 é um fator de risco isolado para recorrência (p= 0,04). Existe uma correlação positiva significativa entre: VEGF e MMP-9 (rs: 0,246; p= 0,023); TIMP-2 e MMP-2 (rs: 0,358; p= 0,001). Também foram encontradas associações significativas entre as variáveis: a) VEGF e receptor de progesterona positivo (p= 0,045); b) TIMP-2 e idade ≥ 50 anos (p= 0,002), e diâmetro ≤ 2,0 cm (p= 0,016); c) TIMP-1 e menarca ≤ 12 anos (p= 0,038); d) Maior diâmetro e alto grau histológico (2: 19,3; p= 0,004), invasão vascular (2: 12,6; p= 0,006), status do linfonodo axilar (2: 8,6; p= 0,035), número de linfonodos metastáticos (2: 7,2; p= 0,028), e recidiva a distancia (2: 4,0; p= 0,046); e) Invasão vascular e status do linfonodo axilar, e número de linfonodos metastáticos, ambos com 2: 24,7; p= 0,000. Conclusões: O número de linfonodos positivos, diâmetro tumoral, e estádio foram identificados como fatores de risco isolado para a ocorrência de recidiva e óbito. A superexpressão de HER2 é fator de risco isolado para a ocorrência de recidiva da doença. Novas pesquisas devem ser realizadas, com padronização de procedimento e um maior número de casos para melhor caracterização da doença. / Background: The World Health Organization estimated approximately 1.38 million new breast cancer cases and 458,000 deaths worldwide for 2008. Most of these (56% of new cases and 64% of deaths) occur in economically developed countries. In Brazil, approximately 52,000 new cases are predicted for 2013. Better understand the heterogeneity of the tumor and microenvironmental characteristics around you, as well as the mechanisms and consequences of their interactions is essential to improve the targeting of existing therapies and develop new therapeutic agents for cancer. Objectives: The aim of this study was to describe the clinical, anatomopathological and immunohistochemical characteristics of a group of patients with operable breast cancer, and investigate the impact of these characteristics on disease staging, disease-free survival and overall survival. In addition, the potential correlations between these characteristics were analyzed. Methods: This is a hospital-based retrospective cohort study of 86 women with primary breast cancer, subjected to surgical and adjuvant treatment between July 1999 and December 2004. Clinicopathological and immunohistochemical (ER, PR, HER2, Ki67 e p53) data were collected from hospital records. The expression of VEGF, MMP-2, MMP-9, TIMP-1 and TIMP-2 was analyzed using the immunohistochemical technique. Continuous variables were assessed with Spearman’s rank correlation coefficient, or the non-parametric Mann-Whitney U or Kruskal-Wallis H tests. Pearson’s 2 test was employed to asses categorical variables. The possibility of survival was estimated using the non-parametric Kaplan-Meier estimator and the semiparametric Cox regression model. Survival curves were compared using the statistical log-rank test. CI was calculated at 95% and p values <0.05 were considered statistically significant. Results: Disease-free survival at 5 and 10 years was 82.2% and 68%, and overall survival 90.2% and 82.9%, respectively. Number of positive lymph nodes (p= 0.00; p= 0.03), tumor diameter (p= 0.01; p= 0.01) and stage (p= 0.00; p= 0.02) were isolated risk factors for relapse and death, respectively. HER2 overexpression was an isolated risk factor for relapse (p= 0.04). There was a significant positive correlation between: VEGF and MMP-9 (rs: 0.246; p= 0.023) and TIMP-2 and MMP-2 (rs: 0.358; p= 0.001). Significant associations were also recorded between the following variables: a) VEGF and progesterone receptor-positive status (p= 0.045); TIMP-2 and age ≥ 50 years (p= 0.002) and diameter ≤ 2.0 cm (p= 0.016); c) TIMP-1 and menarche ≤ 12 years (p= 0.038); d) greater diameter and high histologic grade (2: 19.3; p= 0.004), vascular invasion (2: 12.6; p= 0.006), axillary lymph node status (2: 8.6; p= 0.035), number of metastatic lymph nodes (2: 7.2; p= 0.028) and distant relapse (2: 4.0; p= 0.046); e) vascular invasion and axillary lymph node status and number of metastatic lymph nodes, both with 2: 24.7 and p= 0.000. Conclusion: Number of positive lymph nodes, tumor diameter, and stage were identified as isolated risk factors for relapse and death. HER2 overexpression is an isolated risk factor for the occurrence of relapse. Further studies are needed, with standardization of the procedure and a larger number of cases, for better characterization of the disease.
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Associação de aspectos nutricionais e inflamatórios com remodelação ventricular em pacientes portadores de artrite reumatoide

Baccaro, Antonio January 2017 (has links)
Orientador: Paula Schmidt Azevedo Gaiolla / Abstract: Introduction: Rheumatoid arthritis (RA) is a chronic inflammatory disease that affects not only joints, but also other organs, such as the heart. Systemic inflammation plays a fundamental role in the development of joint and extraarticular involvement. Thus, there is an increased risk for coronary disease in patients with RA. Direct heart involvement can be triggered by the process of cardiac remodeling, such as hypertrophy and changes in cardiac geometry, which can go years without causing symptoms. Another particular feature of AR and also related to chronic inflammation is the fact that they present a body composition with a phenotype more focused on being overweight, but with the possibility of having reduced muscle mass. Obesity, by itself, already raises the risk for cardiac involvement, however, little is known about the participation of body composition variables and some inflammatory markers in the cardiac remodeling of RA patients. Objectives: To evaluate whether body composition and inflammation variables, evaluated by metalloptreteaases (MMP-2 and MMP-9), are associated with remodeling and cardiac function. Methodology: A total of 71 patients with RA underwent clinical, anthropometric evaluation of the body composition by bioimpedance and dual emission X-ray densitometry, cardiac evaluation by transthoracic echocardiography, evaluation of inflammatory activity by DAS-28 and dosage of metalloprotease activity. Logistic and linear regression were performed to evalua... (Complete abstract click electronic access below) / Resumo: Introdução: A artrite reumatoide (AR) é uma doença inflamatória crônica que acomete não apenas articulações, mas também outros órgãos, como por exemplo, o coração. A inflamação sistêmica exerce papel fundamental no desenvolvimento do acometimento articular e extra-articular. Dessa forma, existe risco aumentado para doença coronariana em pacientes com AR. É possível acometimento direto do coração desencadeando o processo de remodelação cardíaca, como a hipertrofia e alterações de geometria cardíaca, que podem passar anos sem causar sintomas. Outra característica particular da AR e também relacionada com a inflamação crônica é o fato de apresentarem composição corporal com fenótipo mais voltado para o sobrepeso, mas com a possibilidade de terem massa muscular reduzida. A obesidade, por si, já eleva o risco para acometimento cardíaco, entretanto, pouco se sabe sobre a participação de variáveis da composição corporal e de alguns marcadores inflamatórios na remodelação cardíaca de pacientes com AR. Objetivos: Avaliar se variáveis da composição corporal e inflamação, avaliada por metalopreteaases (MMP-2 e MMP-9), associam-se à remodelação e função cardíaca. Metodologia: Foram estudados 71 pacientes com AR, submetidos a avaliação clínica, antropométrica, da composição corporal por bioimpedância e densitometria de dupla emissão de radiação X, avaliação cardiológica por ecocardiografia transtorácica, avaliação da atividade inflamatória por DAS-28 e dosagem da atividade das metaloprote... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

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