185 research outputs found

    Energy Metabolism in H460 Lung Cancer Cells: Effects of Histone Deacetylase Inhibitors

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    BACKGROUND: Tumor cells are characterized by accelerated growth usually accompanied by up-regulated pathways that ultimately increase the rate of ATP production. These cells can suffer metabolic reprogramming, resulting in distinct bioenergetic phenotypes, generally enhancing glycolysis channeled to lactate production. In the present work we showed metabolic reprogramming by means of inhibitors of histone deacetylase (HDACis), sodium butyrate and trichostatin. This treatment was able to shift energy metabolism by activating mitochondrial systems such as the respiratory chain and oxidative phosphorylation that were largely repressed in the untreated controls. METHODOLOGY/PRINCIPAL FINDINGS: Various cellular and biochemical parameters were evaluated in lung cancer H460 cells treated with the histone deacetylase inhibitors (HDACis), sodium butyrate (NaB) and trichostatin A (TSA). NaB and TSA reduced glycolytic flux, assayed by lactate release by H460 cells in a concentration dependent manner. NaB inhibited the expression of glucose transporter type 1 (GLUT 1), but substantially increased mitochondria bound hexokinase (HK) activity. NaB induced increase in HK activity was associated to isoform HK I and was accompanied by 1.5 fold increase in HK I mRNA expression and cognate protein biosynthesis. Lactate dehydrogenase (LDH) and pyruvate kinase (PYK) activities were unchanged by HDACis suggesting that the increase in the HK activity was not coupled to glycolytic flux. High resolution respirometry of H460 cells revealed NaB-dependent increased rates of oxygen consumption coupled to ATP synthesis. Metabolomic analysis showed that NaB altered the glycolytic metabolite profile of intact H460 cells. Concomitantly we detected an activation of the pentose phosphate pathway (PPP). The high O(2) consumption in NaB-treated cells was shown to be unrelated to mitochondrial biogenesis since citrate synthase (CS) activity and the amount of mitochondrial DNA remained unchanged. CONCLUSION: NaB and TSA induced an increase in mitochondrial function and oxidative metabolism in H460 lung tumor cells concomitant with a less proliferative cellular phenotype

    Amyloid-β Triggers the Release of Neuronal Hexokinase 1 from Mitochondria

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    Brain accumulation of the amyloid-β peptide (Aβ) and oxidative stress underlie neuronal dysfunction and memory loss in Alzheimer's disease (AD). Hexokinase (HK), a key glycolytic enzyme, plays important pro-survival roles, reducing mitochondrial reactive oxygen species (ROS) generation and preventing apoptosis in neurons and other cell types. Brain isozyme HKI is mainly associated with mitochondria and HK release from mitochondria causes a significant decrease in enzyme activity and triggers oxidative damage. We here investigated the relationship between Aβ-induced oxidative stress and HK activity. We found that Aβ triggered HKI detachment from mitochondria decreasing HKI activity in cortical neurons. Aβ oligomers further impair energy metabolism by decreasing neuronal ATP levels. Aβ-induced HKI cellular redistribution was accompanied by excessive ROS generation and neuronal death. 2-deoxyglucose blocked Aβ-induced oxidative stress and neuronal death. Results suggest that Aβ-induced cellular redistribution and inactivation of neuronal HKI play important roles in oxidative stress and neurodegeneration in AD

    Search for the standard model Higgs boson at LEP

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    Cork oak vulnerability to fire: the role of bark harvesting, tree characteristics and abiotic factors

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    Forest ecosystems where periodical tree bark harvesting is a major economic activity may be particularly vulnerable to disturbances such as fire, since debarking usually reduces tree vigour and protection against external agents. In this paper we asked how cork oak Quercus suber trees respond after wildfires and, in particular, how bark harvesting affects post-fire tree survival and resprouting. We gathered data from 22 wildfires (4585 trees) that occurred in three southern European countries (Portugal, Spain and France), covering a wide range of conditions characteristic of Q. suber ecosystems. Post-fire tree responses (tree mortality, stem mortality and crown resprouting) were examined in relation to management and ecological factors using generalized linear mixed-effects models. Results showed that bark thickness and bark harvesting are major factors affecting resistance of Q. suber to fire. Fire vulnerability was higher for trees with thin bark (young or recently debarked individuals) and decreased with increasing bark thickness until cork was 3–4 cm thick. This bark thickness corresponds to the moment when exploited trees are debarked again, meaning that exploited trees are vulnerable to fire during a longer period. Exploited trees were also more likely to be top-killed than unexploited trees, even for the same bark thickness. Additionally, vulnerability to fire increased with burn severity and with tree diameter, and was higher in trees burned in early summer or located in drier south-facing aspects. We provided tree response models useful to help estimating the impact of fire and to support management decisions. The results suggested that an appropriate management of surface fuels and changes in the bark harvesting regime (e.g. debarking coexisting trees in different years or increasing the harvesting cycle) would decrease vulnerability to fire and contribute to the conservation of cork oak ecosystemsinfo:eu-repo/semantics/publishedVersio

    Nursing care practices at an outpatient care center from an integrative perspective

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    AIM: to analyze nursing care practices at a Specialized Outpatient Care Center from the perspective of an integrative health care activity. METHOD: Interviews with 24 nursing professionals were undertaken. For data analysis, Thematic Content Analysis as proposed by Bardin was applied, resulting in the following themes: the team size and its commitment to health care; professional practices and activity of the nursing team. RESULTS: The size of the nursing team was considered insufficient, which compromises the quality of care and results in work overload and dissatisfaction of the nursing professionals. On the other hand, they were satisfied with the tasks performed day-to-day and related integrality to individual care, considered it essential and usually practiced it daily. CONCLUSION: It is considered that the nursing team has the potential and commitment to develop their care practice combined with the integrative perspective, and therefore providing quality health care to the population.OBJETIVO: analizar las prácticas de Enfermería en un ambulatorio de especialidades, en la perspectiva de la integralidad de las acciones en salud. MÉTODO: Fueron realizadas entrevistas con 24 profesionales de enfermería. Para análisis de los datos se utilizó el análisis de contenido, llegando a los temas: el dimensionamiento y comprometimiento con el servicio de salud; actividades y las prácticas del equipo de enfermería. RESULTADOS: Con relación a lo dimensionamiento, fue revelado que el equipo es insuficiente, comprometiendo la asistencia de calidad, resultando en sobrecarga y descontentamiento de los profesionales. Sin embargo, las personas se mostraran satisfechas con las tareas practicadas en el cotidiano, relacionando la integralidad al cuidado individual, percibido por los profesionales como esencial y, comúnmente, practicado en su cotidiano. CONCLUSIÓN: se considera que el equipo de enfermería tiene potencialidad y comprometimiento para desarrollar su práctica articulada con el principio de la integralidad, atendiendo las necesidades de salud de la población con calidad de la asistencia.OBJETIVO: analisar as práticas de enfermagem em um Ambulatório de Especialidades, na perspectiva da integralidade das ações em saúde. MÉTODO: foram realizadas entrevistas com 24 profissionais de enfermagem. Para análise dos dados, utilizou-se a Análise de Conteúdo, chegando aos temas: o dimensionamento e comprometimento com o Serviço de Saúde; atividades e as práticas da equipe de enfermagem. RESULTADOS: em relação ao dimensionamento, foi revelado que a equipe é insuficiente, comprometendo a assistência de qualidade, resultando em sobrecarga e descontentamento dos profissionais, contudo, mostraram-se satisfeitos com as tarefas praticadas no cotidiano, relacionando a integralidade ao cuidado individual, percebida pelos profissionais como essencial e, usualmente, praticada no seu cotidiano. CONCLUSÃO: considera-se que a equipe de enfermagem tem potencialidade e comprometimento para desenvolver sua prática articulada ao princípio da integralidade, atendendo as necessidades de saúde da população com qualidade de assistência

    Identification of a biomarker panel for improvement of prostate cancer diagnosis by volatile metabolic profiling of urine

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    Background: The lack of sensitive and specific biomarkers for the early detection of prostate cancer (PCa) is a major hurdle to improve patient management. Methods: A metabolomics approach based on GC-MS was used to investigate the performance of volatile organic compounds (VOCs) in general and, more specifically, volatile carbonyl compounds (VCCs) present in urine as potential markers for PCa detection. Results: Results showed that PCa patients (n = 40) can be differentiated from cancer-free subjects (n = 42) based on their urinary volatile profile in both VOCs and VCCs models, unveiling significant differences in the levels of several metabolites. The models constructed were further validated using an external validation set (n = 18 PCa and n = 18 controls) to evaluate sensitivity, specificity and accuracy of the urinary volatile profile to discriminate PCa from controls. The VOCs model disclosed 78% sensitivity, 94% specificity and 86% accuracy, whereas the VCCs model achieved the same sensitivity, a specificity of 100% and an accuracy of 89%. Our findings unveil a panel of 6 volatile compounds significantly altered in PCa patients' urine samples that was able to identify PCa, with a sensitivity of 89%, specificity of 83%, and accuracy of 86%. Conclusions: It is disclosed a biomarker panel with potential to be used as a non-invasive diagnostic tool for PCa.info:eu-repo/semantics/publishedVersio
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