1,363 research outputs found

    Neutrophil extracellular traps (NETs) in cancer-associated thrombosis and tumor progression: role of integrins α5β1, αvβ3 and αIIbβ3

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    Upon infection of pathogens, neutrophils are the first white blood cells activated to entrap and kill invading microorganisms through the processes of phagocytosis or degranulation. A newly discovered mechanism used by neutrophils to eliminate bacteria, viruses and fungi is the release of neutrophil extracellular traps (NETs), web-like structures composed of nucleic acids, histones and selected cytoplasmic proteins, like myeloperoxidase and neutrophil elastase. In addition to their main defensive function, NETs were reported to promote thrombotic events and metastatic dissemination of cancer cells, but the mechanisms underlying these processes have not been elucidated yet. In this PhD thesis project, we tested the role of α5β1, αvβ3 and αIIbβ3 integrins in the adhesion of different human cancer cell lines using cell-free isolated NETs as substrate. Neutrophil-like cells, obtained after differentiating HL-60 cell line with DMSO, were stimulated with calcium ionophore A23187 and used as a stable source of NETs. Two human leukemia cell lines, differentially expressing α5β1 and αvβ3 integrins, were subjected to adhesion assays in the presence or absence of DNAse 1, blocking antibodies against α5β1 or αvβ3, alone or in combination with DNAse 1, and Proteinase K. As expected DNAse 1 treatment strongly inhibited adhesion of both cell lines to NETs. An equivalent significant reduction of cell adhesion to NETs was obtained after treatment of cells with blocking antibodies against α5β1 or αvβ3 indicating that both integrins were able to mediate cell adhesion to NETs. Furthermore, the combination of DNAse 1 and anti-integrin antibody treatment almost completely blocked cell adhesion. Western blot analysis and immunoprecipitation experiments showed a dose-dependent increase of fibronectin levels in samples from stimulated neutrophil-like cells and a direct or indirect interaction of fibronectin with histone H3. Co-immunolocalization studies with confocal microscopy showed that fibronectin and citrullinated histone H3 co-localize inside the web-structure of NETs. Then, we screened a panel of human cancer cell lines endogenously expressing different protein levels of α5β1, αvβ3 and αIIbβ3 integrins in the adhesion to NETs: the concomitant expression of α5β1, αvβ3 and αIIbβ3 integrins was associated to an enhanced adhesion to NETs and the addition of an excess of cyclic RGD peptide inhibited cell adhesion at a different extent in each cell line. Interestingly, the maximal reduction of integrin-dependent adhesion to NETs was similar to that obtained after DNAse 1 treatment, confirming that both DNA and fibronectin determined cell attachment to NETs. Since low or undetectable levels of α5β1 integrin prevents cell adhesion to NETs, this integrin is need to anchor cells in the web-like structure of NETs, allowing a close interaction between cells and DNA/histone complexes. This PhD thesis demonstrated that α5β1, αvβ3 and αIIbβ3 integrins modulate cell adhesion to NETs by binding to their common substrate fibronectin, found to be a protein component of NETs. In addition to mechanical trapping, integrin-mediated cell adhesion to NETs should be taken into account as a mechanism promoting cell-cell interactions at the interface with NETs. Therefore, by using integrins-specific antibodies or the RGD cyclic peptide is possible impairing the homing of different integrins-expressing cell types such as platelets, endothelial and cancer cells to specific sites of NETs accumulation, thus reducing NETs-dependent cancer-associated thrombosis and tumor progression

    Endoscopic Treatment of Postoperative External Biliary Fistula in a Patient Operated on for Hepatic Injury Due to Multiple Trauma

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    After surgery for hepatic injury as a result of blunt abdominal trauma from a motorcycle accident, an external biliary fistula developed in a young patient. The authors describe the rapid and complete healing of the fistula by use of a nasobiliary catheter. These findings emphasize the importance of endoscopic operative technique for postoperative and traumatic external biliary fistulas

    Zero-point fixture systems as a reconfiguration enabler in flexible manufacturing systems

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    ABSTRACT: Today's manufacturing systems need to be able to quickly adapt to customer demands, ranging from high volumes of mass production to high volumes of mass customization. Flexible Manufacturing Systems provide a high degree of flexibility to cope with these challenges. They consist of machine tools capable of executing a wide range of machining operations while the use of pallets to reference and block the parts allows the decoupling of the setup operations from the machining centers activity. This paper presents an ontology-based framework to support the design and management of flexible manufacturing systems, aimed at integrating the various involved activities including the pallet configuration and process planning, the management policies for short-term production planning and the pallet checking to verify the correct configuration of the physical pallet

    On the formation and morphology of coherent particulate structures in non-isothermal enclosures subjected to rotating g-jitters

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    The strategy undertaken in the author's earlier work [M. Lappa, "The patterning behaviour and accumulation of spherical particles in a vibrated non-isothermal liquid," Phys. Fluids 26(9), 093301 (2014) and M. Lappa, "On the multiplicity and symmetry of particle attractors in confined non-isothermal fluids subjected to inclined vibrations," Int. J. Multiphase Flow 93, 71-83 (2017)] based on the use of polarized (purely translational) vibrations for achieving the segregation or accumulation of solid particles in specific regions of an initially dilute dispersion is further pursued by allowing the direction of vibrations to change in time with respect to the applied temperature difference. In particular, the potential of the considered approach in separating the particles from the liquid is explored under the assumption that the angular velocity by which the vibrations axis rotates about a fixed axis is of the same order of magnitude or smaller (one or two orders of magnitude) than the frequency of shaking. A new family of particle coherent structures is identified in the physical space, which can be distinguished from the companion category of particle attractors for fixed vibration direction due to its increased symmetry properties. It is shown how the average nonlinear effects produced by the rotation of the vibration axis, together with those induced by the finite size of the enclosure, accumulate over time leading to the observed fascinating variety of symmetrical patterns

    Radiação infravermelha e interferência no sistema de marcapasso dupla-câmara

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    A radiação infravermelha é utilizada para o tratamento de várias dermatoses inflamatórias. Seu uso, porém, não está descrito para o tratamento de alopecia. Apresentamos o caso de uma portadora de marcapasso dupla-câmara desde 2014, que fez uso de fototerapia para o tratamento desse distúrbio. À avaliação eletrônica, em junho de 2017, foi diagnosticada perda de sensibilidade e comando ventriculares. Durante a cirurgia, foram observadas lesões nos cabos-eletrodos e houve necessidade de troca completa do sistema. Não há relatos de casos similares na literatura

    Health impact of the emissions from a refinery: case-control study on the adult population living in two municipalities in Lomellina, Italy

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    Background: In the municipalities of Sannazzaro de’ Burgondi and Ferrer Erbognone (District of Lomellina, Pavia, Lombardy, Italy), an oil refinery is operating since 1963. In 2008, the company running the plant (eni S.p.A.) asked the competent bodies the permission for building a new facility (“EST”). The present work is aimed at evaluating the ante-operam health impacts of the existing facility refinery. Methods: A case-control study design was implemented. Cases were subjects admitted to hospital in 2002-2014 due to acute respiratory, cardiovascular or gastrointestinal conditions. Controls were selected among those who had not been hospitalised in that timespan. Cases and controls had to be alive at enrolment, aged 20-64 years, and were frequency-matched by age, gender and municipality. Data were extracted from the health insurance registry and from Hospital Discharge Records (ATS Pavia). Enrolled subjects were asked to complete a mailed survey. Environmental exposure was the fallout of refinery emissions (PM10) at participants’ homes, as predicted by an AERMOD model. Results: 541 respondents (125 cases, 416 controls) were included in the analyses. Response bias was excluded. Individual PM10 exposure was not significantly different between cases and controls, while it was significantly associated with municipality (being higher in Sannazzaro). The crude effect estimate of PM10 over case/control status indicated a not-significant excess of hospitalisation with the increase in PM10 exposure. Multivariate analyses confirmed those results. Conclusion: Findings indicate a possible excess of hospitalisation risk in most exposed people, but the effect is not statistically significant and may be affected by bias

    Successful immunosenescence and the remodelling of immune responses with ageing.

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    In recent decades, major theoretical and technological advances have been achieved in the field of immunology. These have allowed the scientific community to analyse the immune system in a much more sophisticated manner than was possible even 20 years ago. Moreover, great theoretical changes have also occurred in gerontology - in particular, the hypothesis has been put forward that ageing and diseases are two different phenomena, and that successful ageing, i.e. ageing in good psychophysical conditions, is really possible for most humans and animals. Immunosenescence was then carefully investigated, either in selected healthy people of advanced age or in the oldest old people, such as healthy centenarians. The main results showed that most immune parameters are indeed well preserved even at this far advanced age. This paper deals with some of the most important theoretical problems of immunosenescence. An immunological tenet was that the most important phenomenon of immunosenescence is the involution of the thymus. In most textbooks and papers it is taken for granted that the thymus starts its involution immediately after puberty. When people aged 60-65 were considered old, it was not difficult to think that they could live for the rest of their life with a fully involuted thymus. The findings on centenarians challenge this tenet, as they have only a small reduction of T lymphocytes, and a relatively normal number of virgin and memory T cells, together with a functional T cell repertoire. Other observations reported here on centenarians, concerning the activity of B lymphocytes and the cytokine network, as well as those on the well-preserved innate immunity and the cells' capability of undergoing proliferation after appropriate stimuli, suggest that complex immune changes occur with age, but also indicate that we have to modify our attitude, to grasp the new scenario which is emerging. Immunosenescence can no longer be considered as a unidirectional deterioration, and this complex phenomenon is much better described by terms such as 'remodelling', 'reshaping' or 'retuning'

    Mechanisms underlying disorders of consciousness: Bridging gaps to move toward an integrated translational science

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    AIM: In order to successfully detect, classify, prognosticate, and develop targeted therapies for patients with disorders of consciousness (DOC), it is crucial to improve our mechanistic understanding of how severe brain injuries result in these disorders. METHODS: To address this need, the Curing Coma Campaign convened a Mechanisms Sub-Group of the Coma Science Work Group (CSWG), aiming to identify the most pressing knowledge gaps and the most promising approaches to bridge them. RESULTS: We identified a key conceptual gap in the need to differentiate the neural mechanisms of consciousness per se, from those underpinning connectedness to the environment and behavioral responsiveness. Further, we characterised three fundamental gaps in DOC research: (1) a lack of mechanistic integration between structural brain damage and abnormal brain function in DOC; (2) a lack of translational bridges between micro- and macro-scale neural phenomena; and (3) an incomplete exploration of possible synergies between data-driven and theory-driven approaches. CONCLUSION: In this white paper, we discuss research priorities that would enable us to begin to close these knowledge gaps. We propose that a fundamental step towards this goal will be to combine translational, multi-scale, and multimodal data, with new biomarkers, theory-driven approaches, and computational models, to produce an integrated account of neural mechanisms in DOC. Importantly, we envision that reciprocal interaction between domains will establish a virtuous cycle, leading towards a critical vantage point of integrated knowledge that will enable the advancement of the scientific understanding of DOC and consequently, an improvement of clinical practice

    Interfering with ROS metabolism in cancer cells: the potential role of quercetin.

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    Abstract: A main feature of cancer cells, when compared to normal ones, is a persistent pro-oxidative state that leads to an intrinsic oxidative stress. Cancer cells have higher levels of reactive oxygen species (ROS) than normal cells, and ROS are, in turn, responsible for the maintenance of the cancer phenotype. Persistent ROS stress may induce adaptive stress responses, enabling cancer cells to survive with high levels of ROS and maintain cellular viability. However, excessive ROS levels render cancer cells highly susceptible to quercetin, one of the main dietary flavonoids. Quercetin depletes intracellular glutathione and increases intracellular ROS to a level that can cause cell death
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