Edson Amaro

Publications (125) View all

• Article: Mesenchymal stem cells from umbilical cord blood: parameters for isolation, characterization and adipogenic differentiation.

  Tatiana Taís Sibov, P Severino, L C Marti, L F Pavon, D M Oliveira, P R Tobo, A H Campos, A T Paes, E Amaro, L F Gamarra, C A Moreira-Filho
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  ABSTRACT: Isolation of mesenchymal stem cells (MSCs) from umbilical cord blood (UCB) from full-term deliveries is a laborious, time-consuming process that results in a low yield of cells. In this study we identified parameters that can be helpful for a successful isolation of UCB-MSCs. According to our findings, chances for a well succeeded isolation of these cells are higher when MSCs were isolated from UCB collected from normal full-term pregnancies that did not last over 37 weeks. Besides the duration of pregnancy, blood volume and storage period of the UCB should also be considered for a successful isolation of these cells. Here, we found that the ideal blood volume collected should be above 80 mL and the period of storage should not exceed 6 h. We characterized UCB-MSCs by morphologic, immunophenotypic, protein/gene expression and by adipogenic differentiation potential. Isolated UCB-MSCs showed fibroblast-like morphology and the capacity of differentiating into adipocyte-like cells. Looking for markers of the undifferentiated status of UCB-MSCs, we analyzed the UCB-MSCs' protein expression profile along different time periods of the differentiation process into adipocyte-like cells. Our results showed that there is a decrease in the expression of the markers CD73, CD90, and CD105 that correlates to the degree of differentiation of UCB-MSCs We suggest that CD90 can be used as a mark to follow the differentiation commitment degree of MSCs. Microarray results showed an up-regulation of genes related to the adipogenesis process and to redox metabolism in the adipocyte-like differentiated MSCs. Our study provides information on a group of parameters that may help with successful isolation and consequently with characterization of the differentiated/undifferentiated status of UCB-MSCs, which will be useful to monitor the differentiation commitment of UCB-MSC and further facilitate the application of those cells in stem-cell therapy.
  Cytotechnology 02/2012; 64(5):511-21. · 1.21 Impact Factor
• Source

  Available from: Silvia Maria Arcuri

  Article: Faulty suppression of irrelevant material in patients with thought disorder linked to attenuated frontotemporal activation.

  S M Arcuri, M R Broome, V Giampietro, E Amaro, T T J Kircher, S C R Williams, C M Andrew, M Brammer, R G Morris, P K McGuire
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  ABSTRACT: Formal thought disorder is a feature schizophrenia that manifests as disorganized, incoherent speech, and is associated with a poor clinical outcome. The neurocognitive basis of this symptom is unclear but it is thought to involve an impairment in semantic processing classically described as a loosening of meaningful associations. Using a paradigm derived from the n400 event-related, potential, we examined the extent to which regional activation during semantic processing is altered in schizophrenic patients with formal thought disorder. Ten healthy control and 18 schizophrenic participants (9 with and 9 without formal thought disorder) performed a semantic decision sentence task during an event-related functional magnetic resonance imaging experiment. We employed analysis of variance to estimate the main effects of semantic congruency and groups on activation and specific effects of formal thought disorder were addressed using post-hoc comparisons. We found that the frontotemporal network, normally engaged by a semantic decision task, was underactivated in schizophrenia, particularly in patients with FTD. This network is implicated in the inhibition of automatically primed stimuli and impairment of its function interferes with language processing and contributes to the production of incoherent speech.
  Schizophrenia research and treatment. 01/2012; 2012:176290.
• Article: Characterization of the biocompatible magnetic colloid on the basis of Fe3O4 nanoparticles coated with dextran, used as contrast agent in magnetic resonance imaging.

  L F Gamarra, E Amaro, S Alves, D Soga, W M Pontuschka, J B Mamani, S M Carneiro, G E S Brito, A M Figueiredo Neto
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  ABSTRACT: The magnetic resonance imaging contrast agent, the so-called Endorem colloidal suspension on the basis of superparamagnetic iron oxide nanoparticles (mean diameter of 5.5 nm) coated with dextran, were characterized on the basis of several measurement techniques to determine the parameters of their most important physical and chemical properties. It is assumed that each nanoparticle is consisted of Fe3O4 monodomain and it was observed that its oxidation to gamma-Fe2O3 occurs at 253.1 degrees C. The Mössbauer spectroscopy have shown a superparamagnetic behavior of the magnetic nanoparticles. The Magnetic Resonance results show an increase of the relaxation times T1, T2, and T2* with decreasing concentration of iron oxide nanoparticles. The relaxation effects of SPIONs contrast agents are influenced by their local concentration as well as the applied field strength and the environment in which these agents interact with surrounding protons. The proton relaxation rates presented a linear behavior with concentration. The measured values of thermo-optic coefficient dn/dT, thermal conductivity kappa, optical birefringence delta n0, nonlinear refractive index n2, nonlinear absorption beta' and third-order nonlinear susceptibility |chi(3)| are also reported.
  Journal of Nanoscience and Nanotechnology 07/2010; 10(7):4145-53. · 1.56 Impact Factor
• Chapter: Synthesis and characterization of silica-coated nanoparticles of magnetite

  R. V. Ferreira, I. L. S. Pereira, L. C. D. Cavalcante, L. F. Gamarra, S. M. Carneiro, E. Amaro, J. D. Fabris, R. Z. Domingues, A. L. Andrade
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  ABSTRACT: Magnetic nanoparticles coated with silica have been subjected of extensive, and, in many aspects, also intensive investigations because of their potential application in different technological fields, particularly in biomedicine. This work was conceived and is being carried out in two main parts: (1) synthesis of the ferrimagnetic nanoparticles, specifically magnetite, and (2) coating these particles with tetraethyl orthosilicate (TEOS). The nanosized magnetite sample was prepared by the reduction–precipitation and the nanomagnetite particles were coated by the sol-gel method, based on the hydrolysis of tetraethyl orthosilicate (TEOS). The so obtained materials were characterized with powder X-ray diffraction (XRD), FTIR spectroscopy, saturation magnetization measurements, and 57Fe Mössbauer spectroscopy at room temperature. KeywordsNanomagnetite-Silica-Coating
  01/2010: pages 265-274;
• Source

  Available from: Hermano Tavares

  Article: Neural activity changes to emotional stimuli in healthy individuals under chronic use of clomipramine.

  J R Cardoso de Almeida, M L Phillips, C T Cerqueira, M Zilberman, D Lobo, E Henna, H Tavares, E Amaro, C Gorenstein, V Gentil, G F Busatto
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  ABSTRACT: Previous functional magnetic resonance imaging (fMRI) studies examined neural activity responses to emotive stimuli in healthy individuals after acute/subacute administration of antidepressants. We now report the effects of repeated use of the antidepressant clomipramine on fMRI data acquired during presentation of emotion-provoking and neutral stimuli on healthy volunteers. A total of 12 volunteers were evaluated with fMRI after receiving low doses of clomipramine for 4 weeks and again after 4 weeks of washout. Fear-, happiness-, anger-provoking and neutral pictures from the International Affective Picture System (IAPS) were used. Data analysis was performed with statistical parametric mapping (P < 0.05). Paired t-test comparisons for each condition between medicated and unmedicated states showed, to negative valence paradigms, decrease in brain activity in the amygdala when participants were medicated. We also demonstrated, across both positive and negative valence paradigms, consistent decreases in brain activity in the medicated state in the anterior cingulate gyrus and insula. This is the first report of modulatory effects of repeated antidepressant use on the central representation of somatic states in response to emotions of both negative and positive valences in healthy individuals. Also, our results corroborate findings of antidepressant-induced temporolimbic activity changes to emotion-provoking stimuli obtained in studies of subjects treated acutely with such agents.
  Journal of Psychopharmacology 05/2009; 24(8):1165-74. · 3.04 Impact Factor