2,011 research outputs found

    Coherence effects in disordered geometries with a field-theory dual

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    We investigate the holographic dual of a probe scalar in an asymptotically Anti-de-Sitter (AdS) disordered background which is an exact solution of Einstein's equations in three bulk dimensions. Unlike other approaches to model disorder in holography, we are able to explore quantum wave-like interference effects between an oscillating or random source and the geometry. In the weak-disorder limit, we compute analytically and numerically the one-point correlation function of the dual field theory for different choices of sources and backgrounds. The most interesting feature is the suppression of the one-point function in the presence of an oscillating source and weak random background. We have also computed analytically and numerically the two-point function in the weak disorder limit. We have found that, in general, the perturbative contribution induces an additional power-law decay whose exponent depends on the distribution of disorder. For certain choices of the gravity background, this contribution becomes dominant for large separations which indicates breaking of perturbation theory and the possible existence of a phase transition induced by disorder.Comment: 36 pages, 19 figs, v3 accepted versio

    Insights into angiogenesis in non-small cell lung cancer : molecular mechanisms, polymorphic genes, and targeted therapies

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    We would like to thank Dr. Miguel Nunes from Department of Informatic of Faculty of Medicine of the University of Porto, Porto, Portugal, for his help in technical support, and Prof. Henrique Queiroga, Department of Pneumology of Faculty of Medicine of the University of Porto, Porto, Portugal, for his critical contribution in this manuscript reviewLung cancer is a highly prevalent disease worldwide. Currently, there are more than 150 million patients with lung cancer in the world, with more than 1 million new cases diagnosed per year. Tumoral angiogenesis is an important hallmark of this disease, but despite being extensively studied, the complete angiogenic mechanisms are not fully elucidated. Recent studies have reported a correlation between pharmacological inhibition of these angiogenic mechanisms and improvement of overall survival in lung cancer patients, mainly for those in advanced stages. The family of vascular endothelial growth factor (VEGF) proteins has critical roles in tumoral angiogenesis. An interaction between VEGF-A and VEGF receptor 2 (VEGFR-2) is the main pathway of activation and maintenance of angiogenesis. In tumors, this process is intimately correlative with progression and metastasis. Some studies suggested that serum levels of VEGF are higher in patients with lung cancer, especially in some types of non-small cell lung cancer (NSCLC). Other studies revealed that genetic polymorphisms of VEGF correlate with susceptibility, prognosis, and therapeutic response of some patients with NSCLC. This paper aims to review the impact of angiogenesis, especially on VEGF pathways, in NSCLC, and highlights the relevance of known and new patents disclosed of anti-angiogenic therapies in these patients

    Lysosomal Cathepsin Release Is Required for NLRP3-Inflammasome Activation by Mycobacterium tuberculosis in Infected Macrophages

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    Lysosomal cathepsin B (CTSB) has been proposed to play a role in the induction of acute inflammation. We hypothesised that the presence of active CTSB in the cytosol is crucial for NLRP3-inflammasome assembly and, consequently, for mature IL-1β generation after mycobacterial infection in vitro. Elevated levels of CTSB was observed in the lungs of mice and rabbits following infection with Mycobacterium tuberculosis (Mtb) H37Rv as well as in plasma from acute tuberculosis patients. H37Rv-infected murine bone marrow-derived macrophages (BMDMs) displayed both lysosomal leakage, with release of CTSB into the cytosol, as well as increased levels of mature IL-1β. These responses were diminished in BMDM infected with a mutant H37Rv deficient in ESAT-6 expression. Pharmacological inhibition of cathepsin activity with CA074-Me resulted in a substantial reduction of both mature IL-1β production and caspase-1 activation in infected macrophages. Moreover, cathepsin inhibition abolished the interaction between NLRP3 and ASC, measured by immunofluorescence imaging in H37Rv-infected macrophages, demonstrating a critical role of the enzyme in NLRP3-inflammasome activation. These observations suggest that during Mtb infection, lysosomal release of activated CTSB and possibly other cathepsins inhibitable by CA07-Me is critical for the induction of inflammasome-mediated IL-1β processing by regulating NLRP3-inflammasome assembly in the cytosol

    Influence of dietary pattern on anti-tuberculosis treatment outcomes in persons with dysglycemia: a Peruvian prospective cohort study

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    IntroductionDietary patterns (DPs) are associated with overall nutritional status and may alter the clinical prognosis of tuberculosis. This interaction can be further intricated by dysglycemia (i.e., diabetes or prediabetes). Here, we identified DPs that are more common with tuberculosis–dysglycemia and depicted their association with tuberculosis treatment outcomes.MethodsA prospective cohort study of persons with tuberculosis and their contacts was conducted in Peru. A food frequency questionnaire and a multidimensional systems biology-based analytical approach were employed to identify DPs associated with these clinical groups. Potential independent associations between clinical features and DPs were analyzed.ResultsThree major DPs were identified. TB–dysglycemia cases more often had a high intake of carbohydrates (DP1). Furthermore, DP1 was found to be associated with an increased risk of unfavorable TB outcomes independent of other factors, including dysglycemia.ConclusionOur findings suggest that the evaluation of nutritional status through DPs in comorbidities such as dysglycemia is a fundamental action to predict TB treatment outcomes. The mechanisms underlying the association between high intake of carbohydrates, dysglycemia, and unfavorable tuberculosis treatment outcomes warrant further investigation

    Severe Plasmodium vivax malaria exhibits marked inflammatory imbalance

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    <p>Abstract</p> <p>Background</p> <p>Despite clinical descriptions of severe vivax malaria cases having been reported, data regarding immunological and inflammatory patterns are scarce. In this report, the inflammatory and immunological status of both mild and severe vivax malaria cases are compared in order to explore immunopathological events in this disease.</p> <p>Methods and Results</p> <p>Active and passive malaria case detections were performed during 2007 in Buritis, Rondônia, in the Brazilian Amazon. A total of 219 participants enrolled the study. Study individuals were classified according to the presence of <it>Plasmodium vivax </it>infection within four groups: non-infected (n = 90), asymptomatic (n = 60), mild (n = 50) and severe vivax infection (n = 19). A diagnosis of malaria was made by microscopy and molecular assays. Since at present no clear criteria define severe vivax malaria, this study adapted the consensual criteria from falciparum malaria. Patients with severe <it>P. vivax </it>infection were younger, had lived for shorter time in the endemic area, and recalled having experienced less previous malaria episodes than individuals with no malaria infection and with mild or asymptomatic infection. Strong linear trends were identified regarding increasing plasma levels of C reactive protein (CRP), serum creatinine, bilirubins and the graduation of disease severity. Plasma levels of tumour necrosis factor (TNF), interferon-gamma(IFN-gamma) and also IFN-gamma/interleukin-10 ratios were increased and exhibited a linear trend with gradual augmentation of disease severity. Both laboratory parameters of organ dysfunction and inflammatory cytokines were reduced during anti-parasite therapy in those patients with severe disease.</p> <p>Conclusion</p> <p>Different clinical presentations of vivax malaria infection present strong association with activation of pro-inflammatory responses and cytokine imbalance. These findings are of utmost importance to improve current knowledge about physiopathological concepts of this serious widespread disease.</p

    Câncer de pulmão não pequenas células metastático: heterogeneidade do tratamento na prática clínica de rotina no Brasil

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    ABSTRACT: Lung cancer is one of the main causes of cancer related deaths. Approximately three quarters of these tumors are non-small cell carcinomas. When diagnosed the majority of patients show the disease locally advanced or metastatic. The chemotherapy is the chosen therapy for patients with advanced lung cancer. The majority of published studies with chemotherapy are performed in academic centers under a strict control of research protocols. PURPOSE: The aim of this study is to evaluate the usual management of metastatic NSCLC patients outside of a clinical trial setting in three different oncologic centers in Brazil. METHODS: This is a retrospective study of patients with metastatic non-small cell lung cancer admitted for treatment in three different Cancer Centers in Brazil. 564 patients from Brazilian public heath system and private/health insurance system were considered for the present study. RESULTS: Among 564 patients in this study, 335 (59.4%) received chemotherapy. For all patients, 47 different regimens of chemotherapy were identified. The median follow-up time was eight months and the overall median survival of all patient population submitted to chemotherapy was 9.7 months. DISCUSSION: There was a great heterogeneity in the regimens of drugs to treat metastatic NSCLC patients. The overall survival was significantly better for patients treated with first line chemotherapy compared to patients that only received best supportive care. Results of prospective randomized clinical trials should be carefully analyzed before transferred to the daily clinical practice.INTRODUÇÃO: O câncer de pulmão é uma das principais causas de morte relacionadas ao câncer. Aproximadamente três quartos destes tumores são carcinoma não pequenas células. Ao diagnóstico, a maioria dos pacientes se apresenta com doença avançada localmente ou metastática. A quimioterapia é o tratamento de escolha para pacientes com câncer de pulmão em estadiamento avançado. A maioria dos estudos publicados com quimioterapia é realizada em centros acadêmicos sob controle rígido de protocolos de pesquisa. OBJETIVO: O objetivo deste estudo é avaliar os resultados do tratamento rotineiro de pacientes com carcinoma de pulmão não pequenas células metastático, fora de protocolos de pesquisa clínica em três centros oncológicos brasileiros. MÉTODO: Trata-se de um estudo retrospectivo de pacientes com câncer de pulmão não pequenas células metastático, admitidos para tratamento em três diferentes centros oncológicos no Brasil. Foram avaliados 564 pacientes neste estudo provenientes do sistema de saúde público e privado. RESULTADOS: Dentre os 564 pacientes deste estudo, 335 (59,4%) receberam quimioterapia. Considerando todos os pacientes, foram identificados 47 esquemas diferentes de quimioterapia. O tempo médio de seguimento foi de oito meses e a sobrevida global mediana de todos os pacientes submetidos à quimioterapia foi de 9,7 meses. DISCUSSÃO: Havia uma grande heterogeneidade de esquemas de drogas para o tratamento de pacientes com câncer de pulmão não pequenas células metastático. A sobrevida global foi significativamente melhor para pacientes tratados com quimioterapia de primeira linha comparado com pacientes que receberam somente tratamento de suporte clínico. Resultados de estudos clínicos prospectivos randomizados deverão ser cuidadosamente analisados antes de serem transferidos para a prática clínica diária

    Role of the chemokines CCL3/MIP-1α and CCL5/RANTES in sponge-induced inflammatory angiogenesis in mice

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    Barcelos, Luciola S Coelho, Amanda M Russo, Remo C Guabiraba, Rodrigo Souza, Adriano L S Bruno-Lima, Guilherme Jr Proudfoot, Amanda E I Andrade, Silvia P Teixeira, Mauro M Microvasc Res. 2009 Sep;78(2):148-54. doi: 10.1016/j.mvr.2009.04.009. Epub 2009 May 8.; International audience; OBJECTIVE: We examined the potential contribution of CCL3 and CCL5 to inflammatory angiogenesis in mice. METHODS: Polyester-polyurethane sponges were implanted in mice and blood vessel counting and hemoglobin, myeloperoxidase and N-acetylglucosaminidase measurements used as indexes for vascularization, neutrophil and macrophage accumulation, respectively. RESULTS: CCL3 and CCL5 were expressed throughout the observation period. Exogenous CCL3 enhanced angiogenesis in WT, but angiogenesis proceeded normally in CCL3(-/-) mice, suggesting that endogenous CCL3 is not critical for sponge-induced angiogenesis in mice. CCL5 expression was detected at day 1, but levels significantly increased thereafter. Exogenous CCL5 reduced angiogenesis in WT mice possible via CCR5 as CCL5 was without an effect in CCR5(-/-) mice. Treatment of WT with the CCR1/CCR5 antagonist, Met-RANTES, prevented neutrophil and macrophage accumulation, but enhanced sponge vascularization. CONCLUSION: Thus, endogenous CCL3 appears not to play a role in driving sponge-induced inflammatory angiogenesis in mice. The effects of CCL5 were anti-angiogenic and appeared to be mediated via activation of CCR5

    tackling malaria

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    Malaria is an infectious disease that affects over 216 million people worldwide, killing over 445,000 patients annually. Due to the constant emergence of parasitic resistance to the current antimalarial drugs, the discovery of new drug candidates is a major global health priority. Aiming to make the drug discovery processes faster and less expensive, we developed binary and continuous Quantitative Structure-Activity Relationships (QSAR) models implementing deep learning for predicting antiplasmodial activity and cytotoxicity of untested compounds. Then, we applied the best models for a virtual screening of a large database of chemical compounds. The top computational predictions were evaluated experimentally against asexual blood stages of both sensitive and multi-drug-resistant Plasmodium falciparum strains. Among them, two compounds, LabMol-149 and LabMol-152, showed potent antiplasmodial activity at low nanomolar concentrations (EC50 <500 nM) and low cytotoxicity in mammalian cells. Therefore, the computational approach employing deep learning developed here allowed us to discover two new families of potential next generation antimalarial agents, which are in compliance with the guidelines and criteria for antimalarial target candidates.publishersversionpublishe
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