Navegando por Palavras-chave "3D reconstruction"

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    Improved detection of incipient vascular changes by a biotechnological platform combining post mortem MRI in situ with neuropathology
    (Elsevier B.V., 2009-08-15) Grinberg, Lea Tenenholz; Amaro Junior, Edson; Silva, Alexandre Valotta da [UNIFESP]; Silva, Rafael Emidio da; Sato, Joao Ricardo; Santos, Denis Dionizio dos; Pacheco, Silmara de Paula; Lucena Ferretti, Renata Eloah de; Paraizo Leite, Renata Elaine; Pasqualucci, Carlos Augusto; Teipel, Stefan J.; Flatz, Wilhelm H.; Heinsen, Helmut; Brazilian Aging Brain Study Grp; Univ Wurzburg; Universidade de São Paulo (USP); Inst Israelita Ensino & Pesquisa Albert Einstein; Universidade Federal de São Paulo (UNIFESP); Universidade Federal do ABC (UFABC); Univ Rostock; Univ Munich
    The histopathological counterpart of white matter hyperintensities is a matter of debate. Methodological and ethical limitations have prevented this question to be elucidated.We want to introduce a protocol applying state-of-the-art methods in order to solve fundamental questions regarding the neuroimaging-neuropathological uncertainties comprising the most common white matter hyperintensities [WMHs] seen in aging. By this protocol, the correlation between signal features in in situ, post mortem MRI-derived methods, including DTI and MTR and quantitative and qualitative histopathology can be investigated. We are mainly interested in determining the precise neuroanatomical substrate of incipient WMHs. A major issue in this protocol is the exact co-registration of small lesion in a tridimensional coordinate system that compensates tissue deformations after histological processing.The protocol is based on four principles: post mortem MRI in situ performed in a short post mortem interval, minimal brain deformation during processing, thick serial histological sections and computer-assisted 3D reconstruction of the histological sections.This protocol will greatly facilitate a systematic study of the location, pathogenesis, clinical impact, prognosis and prevention of WMHs. (C) 2009 Elsevier B.V. All rights reserved.
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    Structural Characterization of the Cell Division Cycle in Strigomonas culicis, an Endosymbiont- Bearing Trypanosomatid
    (Cambridge Univ Press, 2014-02-01) Brum, Felipe Lopes; Costa Catta-Preta, Carolina Moura; Souza, Wanderley de; Schenkman, Sergio [UNIFESP]; Elias, Maria Carolina; Machado Motta, Maria Cristina; Universidade Federal do Rio de Janeiro (UFRJ); Inst Nacl Metrol; Universidade Federal de São Paulo (UNIFESP); Inst Butantan
    Strigomonas culicis (previously referred to as Blastocrithidia culicis) is a monoxenic trypanosomatid harboring a symbiotic bacterium, which maintains an obligatory relationship with the host protozoan. Investigations of the cell cycle in symbiont harboring trypanosomatids suggest that the bacterium divides in coordination with other host cell structures, particularly the nucleus. in this study we used light and electron microscopy followed by three-dimensional reconstruction to characterize the symbiont division during the cell cycle of S. culicis. We observed that during this process, the symbiotic bacterium presents different forms and is found at different positions in relationship to the host cell structures. At the G1/S phase of the protozoan cell cycle, the endosymbiont exhibits a constricted form that appears to elongate, resulting in the bacterium division, which occurs before kinetoplast and nucleus segregation. During cytokinesis, the symbionts are positioned close to each nucleus to ensure that each daughter cell will inherit a single copy of the bacterium. These observations indicated that the association of the bacterium with the protozoan nucleus coordinates the cell cycle in both organisms.
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    Tridimensional ultrastructure and glycolipid pattern studies of Trypanosoma dionisii
    (Elsevier B.V., 2013-12-01) Oliveira, Miriam Pires de Castro [UNIFESP]; Ramos, Thiago Cesar Prata [UNIFESP]; Pinheiro, Adriana Maria Viana Nunes [UNIFESP]; Bertini, Silvio [UNIFESP]; Takahashi, Helio Kiyoshi [UNIFESP]; Straus, Anita Hilda [UNIFESP]; Freymüller-Haapalainen, Edna [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Trypanosoma (Schizotrypanum) dionisii is a non-pathogenic bat trypanosome closely related to Trypanosoma cruzi, the etiological agent of Chaga's disease. Both kinetoplastids present similar morphological stages and are able to infect mammalian cells in culture. in the present study we examined 3D ultrastructure aspects of the two species by serial sectioning epimastigote and trypomastigote forms, and identified common carbohydrate epitopes expressed in T. dionisii, T. cruzi and Leishmania major. A major difference in 3D morphology was that T. dionisii epimastigote forms present larger multivesicular structures, restricted to the parasite posterior region. These structures could be related to T. cruzi reservosomes and are also rich in cruzipain, the major cysteine-proteinase of T. cruzi. We analyzed the reactivity of two monoclonal antibodies: MEST-1 directed to galactofuranose residues of glycolipids purified from Paracoccidioides brasiliensis, and BST-1 directed to glycolipids purified from T. cruzi epimastigotes. Both antibodies were reactive with T. dionisii epimastigotes by indirect immunofluorescense, but we noted differences in the location and intensity of the epitopes, when compared to T. cruzi. in summary, despite similar features in cellular structure and life cycle of T. dionisii and T. cruzi, we observed a unique morphological characteristic in T. dionisii that deserves to be explored. (C) 2013 Elsevier B.V. All rights reserved.