118 research outputs found

    New acquisitions in the physiopathology of multiple myeloma: role of the bone microenvironment

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    Multiple myeloma (MM) is a plasma cell malignancy characterized by the accumulation of malignant plasma cells within the bone marrow (BM). MM cells interact with the microenvironment and induce pathological modifications that in turn support the growth and survival of MM cells. The BM microenvironment consists of various extracellular matrix proteins, and cell components as haematopoietic stem cells, progenitor and precursor cells, immune cells, erythrocytes, BM stromal cells (BMSCs), BM endothelial cells, as well as osteoclasts and osteoblasts that are able to secret several growth factors for MM cells. The direct interactions of MM cells with the microenvironment and the secreted cytokines activate signalling pathways mediating growth, survival, drug resistance and the migration of MM cells as well as osteoclastogenesis and angiogenesis. In this article we underline in particular the new evidences at the basis of the interaction between MM cell and bone cells and the potential role of osteoclast and osteoblast in MM pathophysiology. O mieloma múltiplo (MM) é uma doença maligna das células plasmáticas caracterizada pelo acúmulo de células plasmáticas na medula óssea (MO). As células do MM interagem com o microambiente e induzem modificações patológicas que, por seu turno, propiciam o crescimento e a sobrevida das células do MM. O microambiente da MO consiste de várias proteínas da matriz extracelular e de componentes hematopoéticos: células-tronco, progenitoras e precursoras, células imunes, eritrocitárias, estromais, endoteliais. Possuem também osteoclastos e osteoblastos capazes de secreção de fatores de crescimento das células do MM. A direta interação das células mielomatosas com o microambiente e a secreção de citocinas ativam cascatas sinalizadoras que mediam o crescimento, sobrevida, resistência a drogas e a migração destas células assim como a osteoclastogênese e a angiogênese. Neste artigo explicitamos novas evidências e as bases da interação das células mielomatosas e as células medulares e o provável papel dos osteoclastos e dos osteoblastos na fisiopatologia do MM

    Angiogenic switch in multiple myeloma.

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    Angiogenesis is the hallmark of cancer. Growing evidence indicates that an imbalance between pro- and anti-angiogenic molecules triggers the angiogenic switch during tumor progression. Several molecules, able to affect vascular formation and function, are now beginning to be elucidated. Recent data indicate that angiogenesis also occurs in hematological malignancies. In multiple myeloma it has been demonstrated that patients with active disease have an increase in bone marrow angiogenesis correlated with the progression of disease and an adverse prognosis. The pathophysiology of myeloma-induced angiogenesis is complex and involves either the direct production of angiogenic molecules by myeloma cells or their induction in the microenvironment. In this review we have focalized our attention on the main factors involved in the angiogenic switch that occurs in MM patients

    Smart Wireless Power Transfer Operated by Time-Modulated Arrays via a Two-Step Procedure

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    The paper introduces a novel method for agile and precise wireless power transmission operated by a time-modulated array. The unique, almost real-time reconfiguration capability of these arrays is fully exploited by a two-step procedure: first, a two-element time-modulated subarray is used for localization of tagged sensors to be energized; the entire 16-element TMA then provides the power to the detected tags, by exploiting the fundamental and first-sideband harmonic radiation. An investigation on the best array architecture is carried out, showing the importance of the adopted nonlinear/full-wave computer-aided-design platform. Very promising simulated energy transfer performance of the entire nonlinear radiating system is demonstrated

    A fast and accurate microstrip array model for the analysis of integrated passive components of complex topology

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    The paper describes a fast and easy to implement approximate model lor coupled rrsicrostrip arrays of arbitrary cross sections. The model is based on the extension of quasi-static computational concepts to the dynamic case, via the introduction of frequency-dependent capacitance models. The results obtained are in good agreement with those provided by more complex computational methods such as the spectral-domain approach
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