17 research outputs found

    STROMA FORMATION FROM FRESH and CRYOPRESERVED MONONUCLEAR CELLS OBTAINED AT the PRE and POST-MOBILIZATION PHASES for AUTOLOGOUS PERIPHERAL BLOOD STEM CELL TRANSPLANTATION

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    Univ Texas MD Anderson Canc Ctr, Houston, TX 77030 USAUniversidade Federal de São Paulo, São Paulo, BrazilUniv State São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

    Treatment with chondroitin sulfate to modulate inflammation and atherogenesis in obesity

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    Background and aims: Osteoarthritic patients treated with high doses of chondroitin sulfate (CS) have a lower incidence of coronary heart disease - but the mechanistic aspects of these beneficial effects of CS remain undefined. We examined how CS treatment affects the formation of atheroma via interaction with endothelial cells and monocytes. Methods: We characterized arterial atheromatous plaques by multiphoton microscopy and serum pro-inflammatory cytokines by immunoenzymatic techniques in obese mice receiving CS (1 g/kg/day, i.p.) or vehicle for 6 days. Effects of CS on signaling pathways, cytokine secretion and macrophage migration were evaluated in cultures of human coronary endothelial cells and in a monocyte cell line stimulated with TNF-α by Western blot, immunoenzymatic techniques and transwell migration assays. Results: Treatment of obese mice with CS reduced the extension of foam cell coverage in atheromatous plaques of arterial bifurcations by 62.5%, the serum concentration of IL1β by 70%, TNF-α by 82% and selected chemokines by 25-35%. Cultures of coronary endothelial cells and monocytes stimulated with TNF-α secreted less pro-inflammatory cytokines in the presence of CS (P < 0.01). CS reduced the activation of the TNF-α signaling pathway in endothelial cells (pErk 36% of reduction, and NFκB 33% of reduction), and the migration of activated monocytes to inflamed endothelial cells in transwells (81 ± 6 vs. 13 ± 2, P < 0.001). Conclusions: CS interferes with the pro-inflammatory activation of monocytes and endothelial cells driven by TNF-α thus reducing the propagation of inflammation and preventing the formation of atherosclerotic plaques

    Nasal polyposis : more than a chronic inflammatory disorder : a disease of mechanical dysfunction : the São Paulo position

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    Introduction The importance of our study lies in the fact that we have demonstrated the occurrence of mechanical dysfunction within polypoid tissues, which promotes the development of polyps in the nasal cavity. Objective To change the paradigm of nasal polyposis (NP). In this new conception, the chronic nasal inflammatory process that occurs in response to allergies, to pollution, to changes in the epithelial barrier, or to other factors is merely the trigger of the development of the disease in individuals with a genetic predisposition to an abnormal tissue remodeling process, which leads to a derangement of the mechanical properties of the nasal mucosa and, consequently, allows it to grow unchecked. Data Synthesis We propose a fundamentally new approach to intervening in the pathological process of NP, addressing biomechanical properties, fluid dynamics, and the concept of surface tension. Conclusion The incorporation of biomechanical knowledge into our understanding of NP provides a new perspective to help elucidate the physiology and the pathology of nasal polyps, and new avenues for the treatment and cure of NP

    Matriz extracelular e enzimas degradatórias na hematopoese e doenças onco-hematológicas Extracellular matrix in hematopoiesis and hematologic malignancies

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    A matriz extracelular (MEC) é uma rede complexa composta por quatro grandes classes de macromoléculas: colágenos, proteoglicanos (PGs), glicosaminoglicanos (GAGs) e glicoproteínas adesivas. As interações entre as células e a MEC são cruciais para determinar os padrões de comportamento celular, tais como crescimento, morte, diferenciação e motilidade. A hematopoese é o sistema responsável pela produção das células sangüíneas. O controle da proliferação e diferenciação destas células é feito através da interação das células com o microambiente da medula óssea (matriz extracelular). A adesão de progenitores hematopoéticos a moléculas da MEC e a ativação das integrinas são modulados por uma variedade de citocinas e fatores de crescimento, e esta modulação parece ser o mecanismo de regulação que influencia a proliferação de células-tronco e progenitores hematopoéticos, migração transendotelial ou transestromal e homing. Tanto no processo de migração, homing e invasão tumoral, as células seguem os seguintes passos: 1 - Degradação da MEC por enzimas secretadas pelas células: metaloproteinases, colagenases, plasmina, catepsinas, glicosidases e heparanases; 2 - Locomoção das células na região da MEC previamente degradada pelas enzimas; 3 - Adesão das células via receptores específicos da superfície celular, que geralmente interagem com componentes da MEC. Nas doenças onco-hematológicas, a interação das células neoplásicas com a matriz extracelular também influencia na agressividade e prognóstico da doença.<br>The extracellular matrix (ECM) is a complex structure composed of collagens, proteoglycans, glycosaminoglycans and adhesive glycoproteins. Interactions between the cells and the ECM are crucial to determine cell behavior, such as growth, death, differentiation and motility. Hematopoiesis is the system responsible for the production of blood cells. The control of proliferation and differentiation of these cells is attained through the interaction of the cells with the bone marrow microenvironment. The adhesion of hematopoietic progenitors to ECM molecules and the integrin activation are modulated by a variety of cytokines and growth factors, and this modulation seems to be the mechanism of regulation that influences proliferation of hematopoietic cells, transendothelial/transstromal migration and homing. Both in the migration and homing process, and in tumoral invasion the cells undergo the following steps: 1 - Degradation of the ECM by enzymes, including metalloproteinase, collagenase, plasmin, cathepsin, glycosidase and heparanase, secreted by the cells; 2 - Cell migration through the region previously degraded by enzymes; and 3 - Cell adhesion to specific receptors located on the cellular surface, that generally interact with ECM components. In onco-hematologic diseases, the interaction of neoplastic cells with the extracellular matrix also influences aggressiveness and prognosis of the disease

    Retinal and Ocular Toxicity in Ocular Application of Drugs and Chemicals - Part I: Animal Models and Toxicity Assays

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    Aims: Experimental retinal research has gained great importance due to the ophthalmic pharmacotherapy era. An increasing number of drugs are constantly released into the market for the treatment of retinal diseases. in this review, animal species, animal models and toxicity assays in retinal research are discussed. Methods: An extensive search of the literature was performed to review various aspects of the methods of investigation of drug toxicity. the different types of animal species, as well as single animal models available for the evaluation of safety and efficacy of retinal pharmacotherapy, were identified. in addition, a large variety of reported laboratory techniques were critically examined. Results: in vitro studies are the first-line experiments for the development of a new drug for retinal diseases, using retinal pigment epithelial cells and other cell lines. the next step involves in vivo animal studies where nonhuman primates are considered the gold standard. However, cost and legal issues make their use difficult. Mice and rats provide genetically controlled models for investigations. Pigs, dogs and cats represent good large-size animal models, while rabbits are one of the most used species for retinal toxicity evaluations. Various laboratory methods were identified, including light microscopy, electron microscopy, electroretinography and new emerging methods, such as optical coherence tomography and scanning laser ophthalmoscopy for experimental purposes. Conclusions: A great number of animal species and models are available that simulate retinal diseases and provide experimental data for further human use. Work with animal models should include properly designed toxicity assays to obtain reliable results for safety and efficacy. Copyright (C) 2010 S. Karger AG, BaselUniversidade Federal de São Paulo, Dept Ophthalmol, Vis Inst, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Mol Biol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ophthalmol, Vis Inst, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Mol Biol, São Paulo, BrazilWeb of Scienc
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