92 research outputs found

    Activity in perirhinal and entorhinal cortex predicts perceived visual similarities among category exemplars with highest precision

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    Vision neuroscience has made great strides in understanding the hierarchical organization of object representations along the ventral visual stream (VVS). How VVS representations capture fine-grained visual similarities between objects that observers subjectively perceive has received limited examination so far. In the current study, we addressed this question by focusing on perceived visual similarities among subordinate exemplars of real world-categories. We hypothesized that these perceived similarities are reflected with highest fidelity in neural activity patterns downstream from inferotemporal regions, namely in perirhinal and anterolateral entorhinal cortex in the medial temporal-lobe. To address this issue with fMRI, we administered a modified 1-Back task that required discrimination between category exemplars as well as categorization. Further, we obtained observer-specific ratings of perceived visual similarities, which predicted behavioural performance during scanning. As anticipated, we found that activity patterns in perirhinal and anterolateral entorhinal cortex predicted the structure of perceived visual similarity relationships among category exemplars, including its observer-specific component, with higher precision than any other VVS region. Our findings provide new evidence that subjective aspects of object perception that rely on fine-grained visual differentiation are reflected with highest fidelity in the medial temporal lobe

    Utilização da Aloe vera L. na cicatrização de feridas: uma revisão de literatura

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    Introduction: Medicinal plants are being used as an alternative or therapeutic complement, being Aloe veraL., used for the treatment of several types of cutaneous lesions. Methods: This research consisted of a bibliographical review with a careful selection of articles from the search strategy "PICO" on the efficacy of Aloe vera(babosa) in wound healing, through the electronic databases: PubMed, BVS and SciELO. The uniterms used were: Aloe veraand wound healing and medicinal plants. The data collection was carried out in April and May 2018. Development: 43 articles were identified distributed among the three key words. After this initial result, 06 articles were selected as corresponding to the predefined quality standards, such as clarity of information, adequate methodology and clinical relevance to the proposed study. It was evidenced in three articles that Aloe veradecreases wound healing time when compared to the control group. As for the other three studies, one showed a reduction in wound treatment time when compared to dry gauze without topical agent, but the healing rate was not different when compared to cream without Aloe vera; two studies had positive effects, however the result did not show the efficacy of Aloe vera. Conclusion: In view of the selected articles, only three demonstrated that products containing Aloe veraaccelerate the healing process, however, there is still a lack of available studies on its efficacy to legitimize its use with safety.Introdução: As plantas medicinais estão sendo utilizadas como alternativa ou complemento terapêutico, sendo a Aloe veraL. utilizada para o tratamento de vários tipos de lesões cutâneas. Métodos: Essa pesquisa se configura em uma revisão bibliográfica com seleção criteriosa de artigos a partir de estratégia de busca “PICO” sobre a eficácia de Aloe vera(babosa) na cicatrização de feridas, por intermédio das bases de dados eletrônicas: PubMed, BVS e SciELO. Os unitermos utilizados foram: Aloe vera, cicatrização de feridas e plantas medicinais. O levantamento dos dados foi realizado no período de abril e maio de 2018. Desenvolvimento: Foram identificados 43 artigos distribuídos entre os três unitermos. Após esse resultado inicial, houve seleção de seis artigos que correspondiam aos critérios pré-definidos de qualidade, como clareza das informações, metodologia adequada e relevância clínica ao estudo proposto. Evidenciou-se em três artigos que a Aloe veradiminui o tempo de cicatrização da ferida quando comparados com o grupo controle. Quanto aos outros três estudos, um mostrou redução no tempo de tratamento de ferida quando comparado com gaze seca sem agente tópico, porém a taxa de cicatrização não foi diferente quando comparada com creme sem Aloe vera; dois estudos obtiveram efeitos positivos, entretanto o resultado não evidenciou a eficácia da Aloe vera. Conclusão: Diante dos artigos selecionados, apenas três demonstraram que produtos contendo Aloe veraaceleram o processo de cicatrização, no entanto, ainda há uma carência de estudos disponíveis sobre sua eficácia para legitimar seu uso com segurança

    Influenza C virus NS1 protein counteracts RIG-I-mediated IFN signalling

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    The nonstructural proteins 1 (NS1) from influenza A and B viruses are known as the main viral factors antagonising the cellular interferon (IFN) response, inter alia by inhibiting the retinoic acid-inducible gene I (RIG-I) signalling. The cytosolic pattern-recognition receptor RIG-I senses double-stranded RNA and 5'-triphosphate RNA produced during RNA virus infections. Binding to these ligands activates RIG-I and in turn the IFN signalling. We now report that the influenza C virus NS1 protein also inhibits the RIG-I-mediated IFN signalling. Employing luciferase-reporter assays, we show that expression of NS1-C proteins of virus strains C/JJ/50 and C/JHB/1/66 considerably reduced the IFN-β promoter activity. Mapping of the regions from NS1-C of both strains involved in IFN-β promoter inhibition showed that the N-terminal 49 amino acids are dispensable, while the C-terminus is required for proper modulation of the IFN response. When a mutant RIG-I, which is constitutively active without ligand binding, was employed, NS1-C still inhibited the downstream signalling, indicating that IFN inhibitory properties of NS1-C are not necessarily linked to an RNA binding mechanism

    Cost-effectiveness of percutaneous coronary intervention with cobalt-chromium everolimus eluting stents versus bare metal stents: Results from a patient level meta-analysis of randomized trials

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    Background: Second-generation drug eluting stents (DES) may reduce costs and improve clinical outcomes compared to first-generation DES with improved cost-effectiveness when compared to bare metal stents (BMS). We aimed to conduct an economic evaluation of a cobalt-chromium everolimus eluting stent (Co-Cr EES) compared with BMS in percutaneous coronary intervention (PCI). Objective: To conduct a cost-effectiveness analysis (CEA) of a cobalt-chromium everolimus eluting stent (Co-Cr EES) versus BMS in PCI. Methods: A Markov state transition model with a 2-year time horizon was applied from a US Medicare setting with patients undergoing PCI with Co-Cr EES or BMS. Baseline characteristics, treatment effects, and safety measures were taken from a patient level meta-analysis of 5 RCTs (n=4,896). The base-case analysis evaluated stent-related outcomes; a secondary analysis considered the broader set of outcomes reported in the meta-analysis. Results: The base-case and secondary analyses reported an additional 0.018 and 0.013 quality-adjusted life years (QALYs) and cost savings of 236and236 and 288, respectively with Co-Cr EES versus BMS. Results were robust to sensitivity analyses and were most sensitive to the price of clopidogrel. In the probabilistic sensitivity analysis, Co-Cr EES was associated with a greater than 99% chance of being cost savin

    Sublingual Immunization with a Live Attenuated Influenza A Virus Lacking the Nonstructural Protein 1 Induces Broad Protective Immunity in Mice

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    The nonstructural protein 1 (NS1) of influenza A virus (IAV) enables the virus to disarm the host cell type 1 IFN defense system. Mutation or deletion of the NS1 gene leads to attenuation of the virus and enhances host antiviral response making such live-attenuated influenza viruses attractive vaccine candidates. Sublingual (SL) immunization with live influenza virus has been found to be safe and effective for inducing protective immune responses in mucosal and systemic compartments. Here we demonstrate that SL immunization with NS1 deleted IAV (DeltaNS1 H1N1 or DeltaNS1 H5N1) induced protection against challenge with homologous as well as heterosubtypic influenza viruses. Protection was comparable with that induced by intranasal (IN) immunization and was associated with high levels of virus-specific antibodies (Abs). SL immunization with DeltaNS1 virus induced broad Ab responses in mucosal and systemic compartments and stimulated immune cells in mucosa-associated and systemic lymphoid organs. Thus, SL immunization with DeltaNS1 offers a novel potential vaccination strategy for the control of influenza outbreaks including pandemics

    A Recombinant Influenza A Virus Expressing Domain III of West Nile Virus Induces Protective Immune Responses against Influenza and West Nile Virus

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    West Nile virus (WNV) continues to circulate in the USA and forms a threat to the rest of the Western hemisphere. Since methods for the treatment of WNV infections are not available, there is a need for the development of safe and effective vaccines. Here, we describe the construction of a recombinant influenza virus expressing domain III of the WNV glycoprotein E (Flu-NA-DIII) and its evaluation as a WNV vaccine candidate in a mouse model. FLU-NA-DIII-vaccinated mice were protected from severe body weight loss and mortality caused by WNV infection, whereas control mice succumbed to the infection. In addition, it was shown that one subcutaneous immunization with 105 TCID50 Flu-NA-DIII provided 100% protection against challenge. Adoptive transfer experiments demonstrated that protection was mediated by antibodies and CD4+T cells. Furthermore, mice vaccinated with FLU-NA-DIII developed protective influenza virus-specific antibody titers. It was concluded that this vector system might be an attractive platform for the development of bivalent WNV-influenza vaccines

    Rotavirus NSP1 Inhibits NFκB Activation by Inducing Proteasome-Dependent Degradation of β-TrCP: A Novel Mechanism of IFN Antagonism

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    Mechanisms by which viruses counter innate host defense responses generally involve inhibition of one or more components of the interferon (IFN) system. Multiple steps in the induction and amplification of IFN signaling are targeted for inhibition by viral proteins, and many of the IFN antagonists have direct or indirect effects on activation of latent cytoplasmic transcription factors. Rotavirus nonstructural protein NSP1 blocks transcription of type I IFNα/β by inducing proteasome-dependent degradation of IFN-regulatory factors 3 (IRF3), IRF5, and IRF7. In this study, we show that rotavirus NSP1 also inhibits activation of NFκB and does so by a novel mechanism. Proteasome-mediated degradation of inhibitor of κB (IκBα) is required for NFκB activation. Phosphorylated IκBα is a substrate for polyubiquitination by a multisubunit E3 ubiquitin ligase complex, Skp1/Cul1/F-box, in which the F-box substrate recognition protein is β-transducin repeat containing protein (β-TrCP). The data presented show that phosphorylated IκBα is stable in rotavirus-infected cells because infection induces proteasome-dependent degradation of β-TrCP. NSP1 expressed in isolation in transiently transfected cells is sufficient to induce this effect. Targeted degradation of an F-box protein of an E3 ligase complex with a prominent role in modulation of innate immune signaling and cell proliferation pathways is a unique mechanism of IFN antagonism and defines a second strategy of immune evasion used by rotaviruses

    Acetate Causes Alcohol Hangover Headache in Rats

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    Background: The mechanism of veisalgia cephalgia or hangover headache is unknown. Despite a lack of mechanistic studies, there are a number of theories positing congeners, dehydration, or the ethanol metabolite acetaldehyde as causes of hangover headache. Methods: We used a chronic headache model to examine how pure ethanol produces increased sensitivity for nociceptive behaviors in normally hydrated rats. Results: Ethanol initially decreased sensitivity to mechanical stimuli on the face (analgesia), followed 4 to 6 hours later by inflammatory pain. Inhibiting alcohol dehydrogenase extended the analgesia whereas inhibiting aldehyde dehydrogenase decreased analgesia. Neither treatment had nociceptive effects. Direct administration of acetate increased nociceptive behaviors suggesting that acetate, not acetaldehyde, accumulation results in hangover-like hypersensitivity in our model. Since adenosine accumulation is a result of acetate formation, we administered an adenosine antagonist that blocked hypersensitivity. Discussion: Our study shows that acetate contributes to hangover headache. These findings provide insight into the mechanism of hangover headache and the mechanism of headache induction
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