83 research outputs found

    Cancer stem cells in prostate cancer: implications for targeted therapy

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    Prostate cancer (PCa) is the most frequently diagnosed cancer in men and the second most common cause of cancer-related mortality among men in the developed world. Conventional anti-PCa therapies include surgery, radiation, hormonal ablation, and chemotherapy. Despite increasing efforts, these therapies are not effective for patients with advanced and/or metastatic disease. In most cases, cancer therapies fail due to an incomplete depletion of tumor cells, resulting in tumor relapse. The cancer stem cell (CSC) hypothesis is an emerging model that explains many of the molecular characteristics of oncological disease as well as the tendency of cancers to relapse, metastasize, and develop resistance to conventional therapies. CSCs are a reservoir of cancer cells that exhibit properties of self-renewal and the ability to reestablish the heterogeneous tumor cell population. The existence of PCa stem cells offers a theoretical explanation for many uncertainties regarding PCa and also for treatment resistance and disease progression once clinical cure is achieved. Therapies targeting CSCs might therefore lead to more effective cancer treatments, divergent from a traditional anti-proliferative approach, based on tumor bulk reduction accompanied by CSC-specific inhibition. Here, we focus on reviewing the historical perspective as well as concepts regarding stem cells and CSCs in PCa. In addition, we will report possible strategies and new clinical approaches that address the CSC-based concept of tumorigenesis in PCa. (C) 2017 S. Karger AG, Base

    Association between self-reported and accelerometer-based estimates of physical activity in Portuguese older adults

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    Accurate assessment of physical activity (PA) is crucial in interventions promoting it and in studies exploring its association with health status. Currently, there is a wide range of assessment tools available, including subjective and objective measures. This study compared accelerometer-based estimates of PA with self-report PA data in older adults. Additionally, the associations between PA and health outcomes and PA profiles were analyzed. Participants (n = 110) wore a Xiaomi Mi Band 2® for fifteen consecutive days. Self-reported PA was assessed using the International Physical Activity Questionnaire (IPAQ) and the Yale Physical Activity Survey (YPAS). The Spearman correlation coefficient was used to compare self-reported and accelerometer-measured PA and associations between PA and health. Bland–Altman plots were performed to assess the agreement between methods. Results highlight a large variation between self-reported and Xiaomi Mi Band 2® estimates, with poor general agreement. The highest difference was found for sedentary time. Low positive correlations were observed for IPAQ estimates (sedentary, vigorous, and total PA) and moderate for YPAS vigorous estimates. Finally, self-reported and objectively measured PA associated differently with health outcomes. Summarily, although accelerometry has the advantage of being an accurate method, self-report questionnaires could provide valuable information about the context of the activity.This research was funded by FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the project POCI-01-0145-FEDER-007038. This article has been developed under the scope of the project NORTE-01-0145-FEDER000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). This work was also supported by the project grants MEDPERSYST (POCI-01-0145-FEDER-016428) and GIRO (RESEARCH4COVID, 1st edition, project n. 078) by FCT, and the 2CA-Braga Grant for the 2017 Clinical Research Projects. CD was supported by a combined Ph. D. scholarship from FCT and the company iCognitus4ALL-IT Solutions, Lda, Braga, Portugal (grant number PD/BDE/127831/2016)

    European portuguese version of the User Satisfaction Evaluation Questionnaire (USEQ): transcultural adaptation and validation Study

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    BACKGROUND: Wearable activity trackers have the potential to encourage users to adopt healthier lifestyles by tracking daily health information. However, usability is a critical factor in technology adoption. Older adults may be more resistant to accepting novel technologies. Understanding the difficulties that older adults face when using activity trackers may be useful for implementing strategies to promote their use. OBJECTIVE: The purpose of this study was to conduct a transcultural adaptation of the User Satisfaction Evaluation Questionnaire (USEQ) into European Portuguese and validate the adapted questionnaire. Additionally, we aimed to provide information about older adults’ satisfaction regarding the use of an activity tracker (Xiaomi Mi Band 2). METHODS: The USEQ was translated following internationally accepted guidelines. The psychometric evaluation of the final version of the translated USEQ was assessed based on structural validity using exploratory and confirmatory factor analyses. Construct validity was examined using divergent and discriminant validity analysis, and internal consistency was evaluated using Cronbach α and McDonald ω coefficients. RESULTS: A total of 110 older adults completed the questionnaire. Confirmatory factor analysis supported the conceptual unidimensionality of the USEQ (χ(2)(4)=7.313, P=.12, comparative fit index=0.973, Tucker-Lewis index=0.931, goodness of fit index=0.977, root mean square error of approximation=0.087, standardized root mean square residual=0.038). The internal consistency showed acceptable reliability (Cronbach α=.677, McDonald ω=0.722). Overall, 90% of the participants reported excellent satisfaction with the Xiaomi Mi Band 2. CONCLUSIONS: The findings support the use of this translated USEQ as a valid and reliable tool for measuring user satisfaction with wearable activity trackers in older adults, with psychometric properties consistent with the original version

    Cellular interactions in the tumor microenvironment: the role of secretome

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    Over the past years, it has become evident that cancer initiation and progression depends on several components of the tumor microenvironment, including inflammatory and immune cells, fibroblasts, endothelial cells, adipocytes, and extracellular matrix. These components of the tumor microenvironment and the neoplastic cells interact with each other providing pro and antitumor signals. The tumor-stroma communication occurs directly between cells or via a variety of molecules secreted, such as growth factors, cytokines, chemokines and microRNAs. This secretome, which derives not only from tumor cells but also from cancer-associated stromal cells, is an important source of key regulators of the tumorigenic process. Their screening and characterization could provide useful biomarkers to improve cancer diagnosis, prognosis, and monitoring of treatment responses.Agência financiadora Fundação de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) FAPESP 10/51168-0 12/06048-2 13/03839-1 National Council for Scientific and Technological Development (CNPq) CNPq 306216/2010-8 Fundacao para a Ciencia e a Tecnologia (FCT) UID/BIM/04773/2013 CBMR 1334info:eu-repo/semantics/publishedVersio

    Lung-deposited dose of particulate matter from residential exposure to smoke from wood burning

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    Residential settings are of utmost importance for human exposure, as it is where people spend most of their time. Residential wood combustion is a widespread practice known as a source of indoor particulate matter (PM). Nevertheless, research on the risks of exposure associated with this source is scarce, and a better understanding of respiratory deposition of smoke particles is needed. The dosimetry model ExDoM2 was applied to determine the deposited dose of inhalable particulate matter (PM10) from residential biomass combustion in the human respiratory tract (HRT) of adults and children. The dose was estimated using PM10 exposure concentrations obtained from a field campaign carried out in two households during the operation of an open fireplace and a woodstove. Simultaneously, PM10 levels were monitored outside to investigate the outdoor dose in a rural area strongly impacted by biomass burning emissions. Indoors, the 8-h average PM10 concentrations ranged from 88.3 to 489 μg m-3 and from 69.4 to 122 μg m-3 for the operation of the fireplace and the woodstove, respectively, while outdoor average PM10 concentrations ranged from 17.3 to 94.2 μg m-3. The highest amount of the deposited particles was recorded in the extrathoracic region (68-79%), whereas the deposition was much lower in the tracheobronchial tree (5-6%) and alveolar-interstitial region (16-21%). The total dose received while using the fireplace was more than twofold the one received in the room with a woodstove and more than 10 times higher than in the absence of the source. Overall, indoor doses were higher than the ones received by a subject exposed outdoors, especially at the alveolar-interstitial region. After 24 h of exposure, it was estimated that approximately 35 to 37% of the particles deposited in the HRT were transferred to the gastrointestinal tract, while approximately 2.0-2.5% were absorbed into the blood. The results from exposure and dose of indoor particles gathered in this work suggest that homeowners should be encouraged to upgrade the wood burning technology to reduce the PM levels inside their residences. This study also provides biologically relevant results on the lung deposition of particles from residential biomass burning that can be used as a reference for future research.publishe

    FORMAÇÃO DOS TRABALHADORES E LUTA DE CLASSES

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    Na apresentação deste Dossiê, não podemos deixar de vincular o tema em debate com a conjuntura brasileira. Como encerramos o ano de 2016? Com forças em luta! Diversos grupos, setores, categorias de trabalhadores, estudantes e jovens saíram às ruas, levantando diferentes bandeiras e expressando projetos de sociedade diferenciados. Muitos bateram panelas em defesa da moralização da política e pelo combate à corrupção, seja pela via democrática ou pela força (alguns ativistas chegaram a levantar cartazes pela volta da ditadura militar no país). Outros foram às ruas defender a permanência do governo diante do processo de impeachment e a continuidade das reformas em curso. Há ainda os que exigiam que o governo avançasse de forma mais profunda e radical na direção das reformas econômicas e sociais. Por fim, também ouvimos vozes dos que lutavam pelo fim do capital, como estratégia para a superação das profundas desigualdades sociais

    Characteristics of ash and particle emissions during bubbling fluidised bed combustion of three types of residual forest biomass

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    Combustion of residual forest biomass (RFB) derived from eucalypt (Eucalyptus globulus), pine (Pinus pinaster) and golden wattle (Acacia longifolia) was evaluated in a pilot-scale bubbling fluidised bed reactor (BFBR). During the combustion experiments, monitoring of temperature, pressure and exhaust gas composition has been made. Ash samples were collected at several locations along the furnace and flue gas treatment devices (cyclone and bag filter) after each combustion experiment and were analysed for their unburnt carbon content and chemical composition. Total suspended particles (TSP) in the combustion flue gas were evaluated at the inlet and outlet of cyclone and baghouse filter and further analysed for organic and elemental carbon, carbonates and 57 chemical elements. High particulate matter collection efficiencies in the range of 94-99% were observed for the baghouse, while removal rates of only 1.4-17% were registered for the cyclone. Due to the sand bed, Si was the major element in bottom ashes. Fly ashes, in particular those from eucalypt combustion, were especially rich in CaO, followed by relevant amounts of SiO2, MgO and K2O. Ash characteristics varied among experiments, showing that their inorganic composition strongly depends on both the biomass composition and combustion conditions. Inorganic constituents accounted for TSP mass fractions up to 40 wt%. Elemental carbon, organic matter and carbonates contributed to TSP mass fractions in the ranges 0.58-44%, 0.79-78% and 0.01-1.7%, respectively.publishe

    Effect of industrial and domestic ash from biomass combustion, and spent coffee grounds, on soil fertility and plant growth: experiments at field conditions

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    An experimental study was conducted at field conditions in order to evaluate the effect of application of ash from biomass combustion on some soil fertility characteristics and plant growth. Application of 7.5 Mg ha-1 industrial fly ash (IA), domestic ash (DA), and a 50:50 mix of domestic ash (DA) and spent coffee grounds (SCG) was made in different soil parcels. Lolium perenne seeds were sown and the grown biomass was harvested and quantified after 60 days. Soil samples from each parcel were also collected after that period and characterized. Both soil and grown biomass samples were analyzed for Ca, Mg, Na, K, P, Fe, Mn, Zn, and Al contents. Soil pH was determined before and after amendment. All applications rose significantly soil pH. Domestic ash, whether combined with coffee grounds or not, proved to be efficient at supplying available macronutrients Ca, Mg, K, and P to the soil and also reducing availability of Al (more than industrial ash). However, it inhibited plant growth, even more when combined with spent coffee grounds. As regards to elemental abundance in plant tissue, both domestic ash treatments reduced Ca and enhanced Al contents, unlike industrial ash, which proved less harmful for the load applied in the soil. Hence, it was possible to conclude that application load should be a limiting factor for this management option for the studied materials.publishe
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