4,351 research outputs found

    Extracellular matrix in hematopoiesis and hematologic malignancies

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    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.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.Universidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

    Análise jurídico-teórica do instituto jurídico da cessação do contrato de trabalho – Parte II

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    O fim de uma relação, nomeadamente a laboral, nem sempre é pacífico. Por vezes, pode haver a necessidade de intervenção de um terceiro na resolução de litígios e, normalmente, quando se ouve a palavra “litígios”, pensa-se em Tribunal. Mas, e neste caso concreto de relações de trabalho, existe uma alternativa ao recurso às instâncias judiciais. É a Comissão de Conciliação e Arbitragem de Ponta Delgada, doravante designada por CCA ou Comissão. Todavia, não se logrando qualquer entendimento e/ou acordo entre as partes na dita Comissão, recorre-se, então, se for vontade de alguma das partes, ao Tribunal. Aí, uma vez mais, será tentada a conciliação entre a parte que quis recorrer ao Tribunal, designada de “o autor da ação judicial”, e a outra parte, designada de “o réu/a ré”. Assim, este estudo incidirá sobre as ações judiciais relativas a cessações de contrato de trabalho na Região Autónoma dos Açores (RAA), assim como aquelas ocorridas na dita comissão, a CCA.N/

    Engineering-to-order versus make-to-stock strategy: an analysis at two printing companies

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    Organizations are adopting industrial production models with priority given to reducing costs and increasing the quality of their processes and products. Optimizing and rationalization the inventory management is a great opportunity for these companies conquer these goals. The objective of this paper is to analyze inventory management at two printing companies located in the region of Bauru, where one adopts the Engineering-To-Order (ETO) production system and the other the Make-To-Stock (MTS) production system, highlighting their convergences and oppositions. For their achievement was chosen by the methodology of study of multiple cases (two cases). Data were collected through the intersection of the following tools: semi-structure, document analysis and observation in loco. Revisions are made in theoretical work on the following topics: logistics, management of materials and production planning and control. These themes guided the search, allowing a greatest criticism about the collected data and information generated. The two case studies were presented together with a comparative table of the main aspects of the influence of demand management strategy on the inventory management in two companies. Although the companies adopt different production strategies, there was no significant change observed in inventory management strategy

    ENGINEERING-TO-ORDER VERSUS MAKE-TO-STOCK STRATEGY: AN ANALYSIS AT TWO PRINTING COMPANIES

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    Organizations are adopting industrial production models with priority given to reducing costs and increasing the quality of their processes and products. Optimizing and rationalization the inventory management is a great opportunity for these companies conquer these goals. The objective of this paper is to analyze inventory management at two printing companies located in the region of Bauru, where one adopts the <em style="mso-bidi-font-style: normal;">Engineering-To-Order</em> (ETO) production system and the other the <em style="mso-bidi-font-style: normal;">Make-To-Stock </em>(MTS) production system, highlighting their convergences and oppositions. For their achievement was chosen by the methodology of study of multiple cases (two cases). Data were collected through the intersection of the following tools: semi-structure, document analysis and observation in loco. Revisions are made in theoretical work on the following topics: logistics, management of materials and production planning and control. These themes guided the search, allowing a greatest criticism about the collected data and information generated. The two case studies were presented together with a comparative table of the main aspects of the influence of demand management strategy on the inventory management in two companies. Although the companies adopt different production strategies, there was no significant change observed in inventory management strategy

    Late-onset noninfectious pulmonary complications after allogeneic bone marrow transplantation in Brazil: Incidence, clinical features and influence of tuberculosis

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    Universidade Federal de São Paulo, São Paulo, BrazilHosp Santa Marcelina, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

    Reducing the cost of group communication with semantic view synchrony

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    View Synchrony (VS) is a powerful abstraction in the design and implementation of de- pendable distributed systems. By ensuring that processes deliver the same set of messages in each view, it allows them to maintain consistency across membership changes. However, experience indicates that it is hard to combine strong reliability guarantees as offered by VS with stable high performance. In this paper we propose a novel abstraction, Semantic View Synchrony (SVS), that exploits the application's semantics to cope with high throughput applications. This is achieved by allowing some messages to be dropped while still preserving consistency when new views are installed. Thus, SVS inherits the elegance of view synchronous communi- cation. The paper describes how SVS can be implemented and illustrates its usefulness in the context of distributed multi-player games

    Semantically reliable multicast protocols

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    Reliable multicast protocols can strongly simplify the design of distributed applications. However it is hard to sustain a high multicast throughput when groups are large and heterogeneous. In an attempt to overcome this limitation, previous work has focused on weakening reliability properties. The authors introduce a novel reliability model that exploits semantic knowledge to decide in which specific conditions messages can be purged without compromising application correctness. This model is based on the concept of message obsolescence: a message becomes obsolete when its content or purpose is overwritten by a subsequent message. We show that message obsolescence can be expressed in a generic way and can be used to configure the system to achieve higher multicast throughput.Supported by the 234/J4 Franco/Portuguese Grant and by Praxis/ C/ EEI/ 12202/ 1998, TOPCO

    Semantically reliable multicast: current status and future work

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    In multicast communication systems, a single perturbed recipient can drastically affect the performance of a complete group of processes. One way to alleviate this problem is to weakeri reliability requirements by aliowing some messages to be omitted. We propose a multicast service that exploits semantic knowledge to select which messges can be omitted without compromising the application's correctness. This service is basecf on the concept of message obsolescence: A message becomes obsolete when its content is overwritten or implicitly conveyed by a subsequent message. Besides summarizing initial research results [10] showing that message obsolescence can be expressed in a generic way imd can be used to achieve a higher stable throughput, this text advances a definition of the service and outlines our current research directions

    Semantically reliable multicast: definition, implementation and performance evaluation

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    Semantic reliability is a novel correctness criterion for multicast protocols based on the concept of message obsolescence: A message becomes obsolete when its content or purpose is superseded by a subsequent message. By exploiting obsolescence, a reliable multicast protocol may drop irrelevant messages to find additional buffer space for new messages. This makes the multicast protocol more resilient to transient performance perturbations of group members, thus improving throughput stability. This paper describes our experience in developing a suite of semantically reliable protocols. It summarizes the motivation, definition, and algorithmic issues and presents performance figures obtained with a running implementation. The data obtained experimentally is compared with analytic and simulation models. This comparison allows us to confirm the validity of these models and the usefulness of the approach. Finally, the paper reports the application of our prototype to distributed multiplayer games.POSI/32869/CHS/200

    Hairy cell leukemia: a histo-cytochemical and ultra-structural study

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    We studied five patients with hairy cell leukemia (HCL) diagnosed within the last ten years at the Department of Hematology of Universidade Federal de São Paulo (UNIFESP) - Escola Paulista de Medicina. Our purpose was to analyze the value of transmission electron microscopy (TEM) by comparing this method with the conventional ones. At diagnosis, patients presented weight loss, spleen enlargement and hairy cells (HC) in peripheral blood and bone marrow slides. HC was characterized by morphology and tartrate test resistance in the acid phosphatase reaction (TRAP). At the evaluation time, the amount of HC ranged from 1% to 85% of WBC count. All patients, except two, had phenotype B. In these last two, TRAP as well as phenotype B could not be documented due to low HC numbers in their exams. Cytoplasmatic projections and the absence of lamellar ribosomic complex were the most frequent ultrastructural findings, even in those patients with the lowest HC numbers. Based on these features, TEM is an efficient method for searching for HC at HCL diagnosis and during the course of the disease.Estudamos cinco pacientes com leucemia de células pilosas (LCP), diagnosticada nos últimos dez anos na Disciplina de Hematologia da Escola Paulista de Medicina. O principal objetivo foi analisar o valor da microscopia eletrônica de transmissão (MET) pela comparação deste método com os convencionais. Pacientes apresentavam no diagnóstico perda de peso, esplenomegalia e células pilosas (CP) no sangue periférico e medula óssea. As CP foram caracterizadas pela morfologia e resistência ao tartarato na reação de fosfatase ácida (FATR). Na época em que foram avaliados, a quantidade de CP variou de 1 a 85% da leucometria. Todos os pacientes tinham fenótipo B, excetuando-se dois nos quais FATR e imunofenótipo não puderam ser documentados devido ao baixo número de CP no sangue periférico e medula óssea. Projeções citoplasmáticas e ausência de complexo ribosômico lamelar foram os mais freqüentes achados na MET, mesmo nos pacientes com baixa porcentagem de CP. Baseado nestes achados concluímos que MET é um método eficiente no diagnóstico e evolução da LCP.Universidade Federal de São Paulo (UNIFESP)UNIFESPSciEL
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