145 research outputs found

    Brain tissue segmentation using q-entropy in multiple sclerosis magnetic resonance images

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    The loss of brain volume has been used as a marker of tissue destruction and can be used as an index of the progression of neurodegenerative diseases, such as multiple sclerosis. In the present study, we tested a new method for tissue segmentation based on pixel intensity threshold using generalized Tsallis entropy to determine a statistical segmentation parameter for each single class of brain tissue. We compared the performance of this method using a range of different q parameters and found a different optimal q parameter for white matter, gray matter, and cerebrospinal fluid. Our results support the conclusion that the differences in structural correlations and scale invariant similarities present in each tissue class can be accessed by generalized Tsallis entropy, obtaining the intensity limits for these tissue class separations. In order to test this method, we used it for analysis of brain magnetic resonance images of 43 patients and 10 healthy controls matched for gender and age. The values found for the entropic q index were 0.2 for cerebrospinal fluid, 0.1 for white matter and 1.5 for gray matter. With this algorithm, we could detect an annual loss of 0.98% for the patients, in agreement with literature data. Thus, we can conclude that the entropy of Tsallis adds advantages to the process of automatic target segmentation of tissue classes, which had not been demonstrated previously.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)FAPESPCNP

    Adherence to BCLC recommendations for the treatment of hepatocellular carcinoma: impact on survival according to stage

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    OBJECTIVES: This study sought to assess the adherence of newly diagnosed hepatocellular carcinoma patients to the Barcelona Clinic Liver Cancer system treatment guidelines and to examine the impact of adherence on the survival of patients in different stages of the disease. METHODS: This study included all patients referred for the treatment of hepatocellular carcinoma between 2010 and 2012. Patients (n=364) were classified according to the Barcelona Clinic Liver Cancer guidelines. Deviations from the recommended guidelines were discussed, and treatment was determined by a multidisciplinary team. The overall survival curves were estimated with the Kaplan-Meier method and were compared using the log-rank test. RESULTS: The overall rate of adherence to the guidelines was 52%. The rate of adherence of patients in each scoring group varied as follows: stage 0, 33%; stage A, 45%; stage B, 78%; stage C, 35%; and stage D, 67%. In stage 0/A, adherent patients had a significantly better overall survival than non-adherent patients (hazard ratio=0.19, 95% confidence interval (CI): 0.09-0.42;

    The CD14+CD16+ inflammatory monocyte subset displays increased mitochondrial activity and effector function during acute Plasmodium vivax malaria

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    Infection with Plasmodium vivax results in strong activation of monocytes, which are important components of both the systemic inflammatory response and parasite control. The overall goal of this study was to define the role of monocytes during P. vivax malaria. Here, we demonstrate that P. vivax-infected patients display significant increase in circulating monocytes, which were defined as CD14(+)CD16- (classical), CD14(+)CD16(+) (inflammatory), and CD14loCD16(+) (patrolling) cells. While the classical and inflammatory monocytes were found to be the primary source of pro-inflammatory cytokines, the CD16(+) cells, in particular the CD14(+)CD16(+) monocytes, expressed the highest levels of activation markers, which included chemokine receptors and adhesion molecules. Morphologically, CD14(+) were distinguished from CD14lo monocytes by displaying larger and more active mitochondria. CD14(+)CD16(+) monocytes were more efficient in phagocytizing P. vivax-infected reticulocytes, which induced them to produce high levels of intracellular TNF-alpha and reactive oxygen species. Importantly, antibodies specific for ICAM-1, PECAM-1 or LFA-1 efficiently blocked the phagocytosis of infected reticulocytes by monocytes. Hence, our results provide key information on the mechanism by which CD14(+)CD16(+) cells control parasite burden, supporting the hypothesis that they play a role in resistance to P. vivax infection

    LESÕES ANATOMOPATOLÓGICAS PRESENTES NA INFECÇÃO POR DIOCTOPHYMA RENALE (GOEZE, 1782) EM CÃES DOMÉSTICOS (CANIS FAMILIARIS,) LINNAEUS, 1758

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    Os autores descrevem as lesÔes anatomopatológicas de onze casos de parasitismo por Dioctophyma renale (Goeze, 1782), na cidade de Curitiba - PR, Brasil, constatados em necrópsias e achados clínicos em 1960 cães, no período de 1979 a 2004. Anatomopathologic lesions found in Dioctophyma renale (Goeze, 1782) infections in domestic dogs (Canis familiaris, LINNAEUS, 1758 Abstract The authors describe the anatomopathologic lesions of eleven cases of parasitism by Dioctophyma renale (Goeze, 1782), in Curitiba (PR, Brazil), found among 1960 necropsies carried out between 1979 and 2004 in dogs

    Measurement of the Bs0→J/ψKS0B_s^0\to J/\psi K_S^0 branching fraction

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    The Bs0→J/ψKS0B_s^0\to J/\psi K_S^0 branching fraction is measured in a data sample corresponding to 0.41fb−1fb^{-1} of integrated luminosity collected with the LHCb detector at the LHC. This channel is sensitive to the penguin contributions affecting the sin2ÎČ\beta measurement from B0→J/ψKS0B^0\to J/\psi K_S^0 The time-integrated branching fraction is measured to be BF(Bs0→J/ψKS0)=(1.83±0.28)×10−5BF(B_s^0\to J/\psi K_S^0)=(1.83\pm0.28)\times10^{-5}. This is the most precise measurement to date
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