61 research outputs found

    Effect of partially purified fumonisins on cellular immune response in experimental murine paracoccidioidomycosis

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    Fumonisins are mycotoxins produced mainly by Fusarium verticillioides, which can modulate the immune response. Paracoccidioidomycosis (PCM), caused by the fungus Paracoccodioides brasiliensis (Pb), is one of the most important systemic mycoses in Latin America. The aim of this study was to evaluate the effect of the partially purified fumonisins on cellular immune response in mice infected with Pb. Four groups of male BALB/c mice were used. Groups PB and PB/FB were inoculated i.v. with 1 × 105 Pb yeast cells and, after 28 days, groups FB and PB/FB were inoculated (s.c.) with partially purified fumonisin B1 from F. verticillioides (5 × 2.25 mg FB1/kg body weight). After 7 days, cellular immune response was evaluated by delayed-type hypersensitivity (DTH) and lymphoproliferative assays (LA) using spleen cells. Nitric oxide (NO) production by spleen cells was also evaluated. The specific LA response to Pb antigen was higher in group PB than in FB and CTR groups (p< 0.05) but not significant with PB/FB. The DTH response was higher in infected than non infected groups (p<0.05) but also no significantly with PB and PB/FB groups. The lyphoproliferative response to ConA was decreased in FB or PB/FB in relation to CTR (p<0.05) but not with PB/FB and also a reduction of NO levels was observed in fumonisin treated in relation to control group FB1/kg (p<0.05). In conclusion, fumonisin B1 or other components of F. verticillioides extracts significantly suppress the unspecific cellular immune response and the NO production by splenocytes from P. brasiliensis infected or not infected BALB/c mice.Keywords: Fumonisin, Paracoccodioides brasiliensis, lymphoproliferative assay, nitric oxideAfrican Journal of Biotechnology Vol. 12(42), pp. 6126-613

    Optimized Dynamical Decoupling in a Model Quantum Memory

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    We present experimental measurements on a model quantum system that demonstrate our ability to dramatically suppress qubit error rates by the application of optimized dynamical decoupling pulse sequences in a variety of experimentally relevant noise environments. We provide the first demonstration of an analytically derived pulse sequence developed by Uhrig, and find novel sequences through active, real-time experimental feedback. These new sequences are specially tailored to maximize error suppression without the need for a priori knowledge of the ambient noise environment. We compare these sequences against the Uhrig sequence, and the well established CPMG-style spin echo, demonstrating that our locally optimized pulse sequences outperform all others under test. Numerical simulations show that our locally optimized pulse sequences are capable of suppressing errors by orders of magnitude over other existing sequences. Our work includes the extension of a treatment to predict qubit decoherence under realistic conditions, including the use of finite-duration, square π\pi pulses, yielding strong agreement between experimental data and theory for arbitrary pulse sequences. These results demonstrate the robustness of qubit memory error suppression through dynamical decoupling techniques across a variety of qubit technologies.Comment: Subject to press embarg

    AAV2-Mediated Combined Subretinal Delivery of IFN-α and IL-4 Reduces the Severity of Experimental Autoimmune Uveoretinitis

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    We previously showed that adeno-associated virus 2 (AAV2) mediated subretinal delivery of human interferon-alpha (IFN-α) could effectively inhibit experimental autoimmune uveoretinitis (EAU). In this study we investigated whether subretinal injection of both AVV2.IFN-α and AAV2.IL-4 had a stronger inhibition on EAU activity. B10RIII mice were subretinally injected with AAV2.IFN-α alone (1.5×107 vg), AAV2.IL-4 alone (3.55×107 vg), and AAV2.IFN-α combined with AAV2.IL-4. PBS, AAV2 vector encoding green fluorescent protein (AAV2.GFP) (5×107 vg) was subretinally injected as a control. IFN-α and IL-4 were effectively expressed in the eyes from three weeks to three months following subretinal injection of AAV2 vectors either alone or following combined administration and significantly attenuated EAU activity clinically and histopathologically. AAV2.IL-4 showed a better therapeutic effect as compared to AAV2.IFN-α. The combination of AAV2.IL-4 and AAV2.IFN-α was not significantly different as compared to AAV2.IL-4 alone. There was no difference concerning DTH (delayed-type hypersensitivity) reaction, lymphocyte proliferation and IL-17 production among the investigated treatment groups, suggesting that local retinal gene delivery did not affect the systemic immune response

    Language development after cochlear implantation: an epigenetic model

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    Growing evidence supports the notion that dynamic gene expression, subject to epigenetic control, organizes multiple influences to enable a child to learn to listen and to talk. Here, we review neurobiological and genetic influences on spoken language development in the context of results of a longitudinal trial of cochlear implantation of young children with severe to profound sensorineural hearing loss in the Childhood Development after Cochlear Implantation study. We specifically examine the results of cochlear implantation in participants who were congenitally deaf (N = 116). Prior to intervention, these participants were subject to naturally imposed constraints in sensory (acoustic–phonologic) inputs during critical phases of development when spoken language skills are typically achieved rapidly. Their candidacy for a cochlear implant was prompted by delays (n = 20) or an essential absence of spoken language acquisition (n = 96). Observations thus present an opportunity to evaluate the impact of factors that influence the emergence of spoken language, particularly in the context of hearing restoration in sensitive periods for language acquisition. Outcomes demonstrate considerable variation in spoken language learning, although significant advantages exist for the congenitally deaf children implanted prior to 18 months of age. While age at implantation carries high predictive value in forecasting performance on measures of spoken language, several factors show significant association, particularly those related to parent–child interactions. Importantly, the significance of environmental variables in their predictive value for language development varies with age at implantation. These observations are considered in the context of an epigenetic model in which dynamic genomic expression can modulate aspects of auditory learning, offering insights into factors that can influence a child’s acquisition of spoken language after cochlear implantation. Increased understanding of these interactions could lead to targeted interventions that interact with the epigenome to influence language outcomes with intervention, particularly in periods in which development is subject to time-sensitive experience

    The role of intracellular trafficking of CdSe/ZnS QDs on their consequent toxicity profile

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    Nanoparticle interactions with cellular membranes and the kinetics of their transport and localization are important determinants of their functionality and their biological consequences. Understanding these phenomena is fundamental for the translation of such NPs from in vitro to in vivo systems for bioimaging and medical applications. Two CdSe/ZnS quantum dots (QD) with differing surface functionality (NH2 or COOH moieties) were used here for investigating the intracellular uptake and transport kinetics of these QDs.status: publishe

    Triagem auditiva neonatal: incidência de deficiência auditiva neonatal sob a perspectiva da nova legislação paulista Neonatal auditory screening: the incidence of neonatal hearing impairment in the context of the new São Paulo legislation

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    OBJETIVOS: identificar a incidência de recém-nascidos com deficiência auditiva, em maternidade particular da cidade de São Paulo. MÉTODOS: estudo de coorte transversal, realizado no período de 2004 a 2008, em maternidade localizada na zona sul da cidade de São Paulo, com 20.615 recém-nascidos de ambos os sexos, sem indicadores de risco para deficiência auditiva e submetidos à triagem auditiva neonatal. O teste foi realizado por intermédio das Emissões Otoacústicas Evocadas Transientes (EOAET). Os pacientes que falharam nas EOAET nas duas fases foram encaminhados para a realização do Potencial Evocado Auditivo do Tronco Encefálico (PEATE) para a confirmação da deficiência auditiva neonatal. Empregou-se o Teste Exato de Fischer e o nível de significância adotado foi de 0,05 oup<0,05. RESULTADOS: a incidência de deficiência auditiva neonatal encontrada neste estudo foi de 1,2/1000. CONCLUSÃO: a legislação estadual permite que a triagem auditiva neonatal (TAN) seja mais efetiva na detecção precoce da deficiência auditiva neonatal. A TAN evita prejuízos tanto no desenvolvimento oral quanto da linguagem no contexto social, profissional e educacional.<br>OBJECTIVES: to determine the incidence of hearing impairment in newborns, at a private maternity hospital in the city of São Paulo. METHODS: a cross-sectional cohort study was carried out covering the period between 2004 and 2008, at a maternity hospital located in the southern zone of the city of São Paulo, including 20,615 newborns of both sexes, with no risk factors for hearing impairment and who had undergone neonatal auditory screening. The test was carried out using the Evoked Transient Otoacoustic Emissions test. Patients who failed both phases of this test were referred to do a Brainstem Auditory Evoked Potential test to confirm the presence of neonatal auditory deficiency. Fischer 's exact test was used with a level of significance of 0.05 orp<0.05. RESULTS: the incidence of neonatal hearing impairment found in this study was 1.2/1000. CONCLUSION: state legislation allows neonatal auditory screening to be more effective in achieving early detection of neonatal hearing impairment. Neonatal auditory screening prevents future impairment of oral development and language acquisition in a social, professional and educational context
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