29 research outputs found

    HIV Aspartyl Peptidase Inhibitors Interfere with Cellular Proliferation, Ultrastructure and Macrophage Infection of Leishmania amazonensis

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    Submitted by Sandra Infurna ([email protected]) on 2019-01-08T13:43:09Z No. of bitstreams: 1 Ellenf_Altoe_etal_IOC_2009.pdf: 1452755 bytes, checksum: 77127a59920cef6bca71296107f6ec63 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2019-01-08T13:51:34Z (GMT) No. of bitstreams: 1 Ellenf_Altoe_etal_IOC_2009.pdf: 1452755 bytes, checksum: 77127a59920cef6bca71296107f6ec63 (MD5)Made available in DSpace on 2019-01-08T13:51:34Z (GMT). No. of bitstreams: 1 Ellenf_Altoe_etal_IOC_2009.pdf: 1452755 bytes, checksum: 77127a59920cef6bca71296107f6ec63 (MD5) Previous issue date: 2009Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. LaboratĂłrio de Biologia Molecular e Doenças EndĂŞmicas. Rio de Janeiro, RJ. Brasil.Universidade Federal do Rio de Janeiro. Centro de CiĂŞncias da SaĂşde. Instituto de Microbiologia Prof. Paulo de GĂłes. Departamento de Microbiologia Geral,. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. LaboratĂłrio de Biologia Molecular e Doenças EndĂŞmicas. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. LaboratĂłrio de Biologia Molecular e Doenças EndĂŞmicas. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. LaboratĂłrio de Biologia Molecular e Doenças EndĂŞmicas. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. LaboratĂłrio de Biologia Molecular e Doenças EndĂŞmicas. Rio de Janeiro, RJ. Brasil.Universidade Federal do Rio de Janeiro. Centro de CiĂŞncias da SaĂşde. Instituto de BiofĂ­sica Carlos Chagas Filho. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Centro de CiĂŞncias da SaĂşde. Instituto de Microbiologia Prof. Paulo de GĂłes. Departamento de Microbiologia Geral,. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Centro de CiĂŞncias da SaĂşde. Instituto de Microbiologia Prof. Paulo de GĂłes. Departamento de Microbiologia Geral,. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. LaboratĂłrio de Biologia Molecular e Doenças EndĂŞmicas. Rio de Janeiro, RJ. Brasil.Leishmania is the etiologic agent of leishmanisais, a protozoan disease whose pathogenic events are not well understood. Current therapy is suboptimal due to toxicity of the available therapeutic agents and the emergence of drug resistance. Compounding these problems is the increase in the number of cases of Leishmania-HIV coinfection, due to the overlap between the AIDS epidemic and leishmaniasis

    Hyaluronic acid hydrogels incorporating platelet lysate enhance human pulp cell proliferation and differentiation

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    The restoration of dentine-pulp complex remains a challenge for dentists; nonetheless, it has been poorly addressed. An ideal system should modulate the host response, as well as enable the recruitment, proliferation and differentiation of relevant progenitor cells. Herein was proposed a photocrosslinkable hydrogel system based on hyaluronic acid (HA) and platelet lysate (PL). PL is a cocktail of growth factors (GFs) and cytokines involved in wound healing orchestration, obtained by the cryogenic processing of platelet concentrates, and was expected to provide the HA hydrogels specific biochemical cues to enhance pulp cellsâ recruitment, proliferation and differentiation. Stable HA hydrogels incorporating PL (HAPL) were prepared after photocrosslinking of methacrylated HA (Met-HA) previously dissolved in PL, triggered by the Ultra Violet activated photoinitiator Irgacure 2959. Both the HAPL and plain HA hydrogels were shown to be able to recruit cells from a cell monolayer of human dental pulp stem cells (hDPSCs) isolated from permanent teeth. The hDPCs were also seeded directly over the hydrogels (5 Ã 104 cells/hydrogel) and cultured in osteogenic conditions. Cell metabolism and DNA quantification were higher, in all time-points, for PL supplemented hydrogels (p < 0,05). Alkaline phosphatase (ALPL) activity and calcium quantification peaks were observed for the HAPL group at 21 days (p < 0,05). The gene expression for ALPL and COLIA1 was up-regulated at 21 days to HAPL, compared with HA group (p < 0,05). Within the same time point, the gene expression for RUNX2 did not differ between the groups. Overall, data demonstrated that the HA hydrogels incorporating PL increased the cellular metabolism and stimulate the mineralized matrix deposition by hDPSCs, providing clear evidence of the potential of the proposed system for the repair of damaged pulp/dentin tissue and endodontics regeneration.LFDA acknowledges Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) for the grant 2014/12017-8. Portuguese Foundation for Science and Technology (FCT) for PSB PhD grant SFRH/BD/73403/2010, MTR post-doctoral grant (SFRH/BPD/111729/2015), MEG grant (IF/00685/2012), and RECOGNIZE project (UTAP-ICDT/CTM-BIO/0023/2014), RL3-TECT - NORTE-07-0124-FEDER-000020 project co-financed by ON.2 (NSRF) through ERD. This study also received financial support from FCT/MinistÊrio da Ciência, Tecnologia, e Ensino Superior (FCT/MCTES) and Fundo Social Europeu through Programa Operacional do Capital Humano (FSE/POCH) PD/59/2013 for the LA ICVS-3Bs (UID/Multi/50026/2013). The authors would like to thank Maurizio Gulino, for its support in the in vitro experiments and Maló Clinic, Porto, Dra Ana Ferro and Dr Bruno Queridinha for the donation of permanent teethinfo:eu-repo/semantics/publishedVersio

    The surface charge of trypanosomatids

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    The ubiquitous gp63-like metalloprotease from lower trypanosomatids: in the search for a function

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    Search for neutral minimal supersymmetric standard model higgs bosons decaying to tau pairs in pp collisions at √s=7TeV

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    A search for neutral minimal supersymmetric standard model (MSSM) Higgs bosons in pp collisions at the LHC at a center-of-mass energy of 7 TeV is presented. The results are based on a data sample corresponding to an integrated luminosity of 36 pb(-1) recorded by the CMS experiment. The search uses decays of the Higgs bosons to tau pairs. No excess is observed in the tau-pair invariant-mass spectrum. The resulting upper limits on the Higgs boson production cross section times branching fraction to tau pairs, as a function of the pseudoscalar Higgs boson mass, yield stringent new bounds in the MSSM parameter space

    Identification of sialic acids on the cell surface of Candida albicans

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    The cell-surface expression of sialic acids in two isolates of Candida albicans was analyzed by thin-layer and gas chromatography, binding of lectins, colorimetry, sialidase treatment and flow cytofluorimetry with fluorescein-labeled lectins. N-acetylneuraminic acid (NANA) was the only derivative found in both strains of C. albicans grown in a chemically defined medium. Its identification was confirmed by mass spectrometry in comparison with an authentic standard. the density of sialic acid residues per cell ranged from 1.6x10(6) to 2.8x10(6). the surface distribution of sialic acids over the entire C. albicans was inferred from labeling with fluorescein-Limulus polyphemus and Limax flavus agglutinins and directly observed by optical microscopy with (FITC)-Sambucus nigra agglutinin (SNA), abrogated by previous treatment of yeasts with bacterial sialidase. Sialidase-treated yeasts generated beta-galactopyranosyl terminal residues that reacted with peanut agglutinin. in C. albicans N-acetyl-neuraminic acids are alpha 2,6- and alpha 2,3-linked as indicated by yeast binding to SNA and Maackia amurensis agglutinin. the alpha 2,6-linkage clearly predominated in both strains. We also investigated the contribution of sialic acids to the electronegativity of C. albicans, an important factor determining fungal interactions in vivo. Adhesion of yeast cells to a cationic solid phase substrate (poly-L-lysine) was mediated in part by sialic acids, since the number of adherent cells was significantly reduced after treatment with bacterial sialidase. the present evidence adds C. albicans to the list of pathogenic Fungi that synthesize sialic acids, which contribute to the negative charge of fungal cells and have a role in their specific interaction with the host tissue. (C) 2000 Elsevier Science B.V. All rights reserved.Univ Fed Rio de Janeiro, Inst Microbiol Prof Paulo Goes, Dept Microbiol Geral, BR-21941590 Rio de Janeiro, BrazilUniversidade Federal de SĂŁo Paulo, Disciplina Biol Celular, BR-04023062 SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo, Disciplina Biol Celular, BR-04023062 SĂŁo Paulo, BrazilWeb of Scienc

    Differential expression of sialylglycoconjugates and sialidase activity in distinct morphological stages of Fonsecaea pedrosoi

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    The expression of sialoglycoconjugates in Fonsecaea pedrosoi conidia, mycelia, and sclerotic cells was analyzed using influenza A and C virus strains, sialidase treatment, and lectin binding. Conidium and mycelium whole cells were recognized by Limax flavus (LFA), Maackia amurensis (MAA), and Sambucus nigra (SNA) lectins, denoting the presence of surface sialoglycoconjugates containing alpha2,3- and alpha2,6-sialylgalactosyl sequences. Sialidase-treated conidia reacted more intensively with peanut agglutinin (PNA), confirming the occurrence of sialyl-galactosyl linkages. Conidial cells agglutinated in the presence of influenza A and C virus strains, which confirmed the results obtained from lectin-binding experiments and revealed the presence of sialoglycoconjugates bearing 9-O-acetyl-N-acetylneuraminic acid (Neu5,9Ac(2)) surface structures. Western blotting analysis with peroxidase-labeled LFA demonstrated the occurrence of sialylglycoproteins in protein extracts from conidia and mycelia, with molecular masses corresponding to 56 and 40 kDa. An additional band of 77 kDa was detected in conidial extracts, suggesting an association between sialic acid expression and morphogenesis. Synthesis of sialic acids was correlated with sialidase expression, since both conidial and mycelial morphological stages presented secreted and cell-associated enzyme activity. Sialoglycoconjugates were not detected in F. pedrosoi sclerotic cells from in vitro and in vivo sources, which also do not express sialidase activity. the surface sialyl residues in F. pedrosoi are apparently involved in the fungal interaction with immune effector cells, since sialidase-treated conidia were less resistant to phagocytosis by human neutrophils from healthy individuals. These findings suggest that sialic acid expression in F. pedrosoi varies according to the morphological transition and may protect infecting propagules against immune destruction by host cells.Univ Fed Rio de Janeiro, Ctr Ciencias Saude, Inst Microbiol Prof Paulo de Goes, BR-21941590 Rio de Janeiro, BrazilUniversidade Federal de SĂŁo Paulo, Disciplina Biol Celular, BR-04023062 SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo, Disciplina Biol Celular, BR-04023062 SĂŁo Paulo, BrazilWeb of Scienc
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