17 research outputs found

    A História da Alimentação: balizas historiográficas

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    Os M. pretenderam traçar um quadro da História da Alimentação, não como um novo ramo epistemológico da disciplina, mas como um campo em desenvolvimento de práticas e atividades especializadas, incluindo pesquisa, formação, publicações, associações, encontros acadêmicos, etc. Um breve relato das condições em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biológica, a econômica, a social, a cultural e a filosófica!, assim como da identificação das contribuições mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histórica, foi ela organizada segundo critérios morfológicos. A seguir, alguns tópicos importantes mereceram tratamento à parte: a fome, o alimento e o domínio religioso, as descobertas européias e a difusão mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rápido balanço crítico da historiografia brasileira sobre o tema

    Innate Immunity and Biomaterials at the Nexus: Friends or Foes

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    Biomaterial implants are an established part of medical practice, encompassing a broad range of devices that widely differ in function and structural composition. However, one common property amongst biomaterials is the induction of the foreign body response: an acute sterile inflammatory reaction which overlaps with tissue vascularisation and remodelling and ultimately fibrotic encapsulation of the biomaterial to prevent further interaction with host tissue. Severity and clinical manifestation of the biomaterial-induced foreign body response are different for each biomaterial, with cases of incompatibility often associated with loss of function. However, unravelling the mechanisms that progress to the formation of the fibrotic capsule highlights the tightly intertwined nature of immunological responses to a seemingly noncanonical "antigen." In this review, we detail the pathways associated with the foreign body response and describe possible mechanisms of immune involvement that can be targeted. We also discuss methods of modulating the immune response by altering the physiochemical surface properties of the biomaterial prior to implantation. Developments in these areas are reliant on reproducible and effective animal models and may allow a "combined" immunomodulatory approach of adapting surface properties of biomaterials, as well as treating key immune pathways to ultimately reduce the negative consequences of biomaterial implantation.Susan N. Christo, Kerrilyn R. Diener, Akash Bachhuka, Krasimir Vasilev, and John D. Haybal

    Synthesising multi-dimensional excitation dynamics and localisation transition in one-dimensional lattices

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    The excitation dynamics in complex networks1 can describe the fundamental aspects of transport and localization across multiple fields of science, ranging from solid-state physics and photonics to biological signalling pathways and neuromorphic circuits2,3,4,5. Although the effects of increasing network dimensionality are highly non-trivial, their implementation likewise becomes ever more challenging due to the exponentially growing numbers of sites and connections6,7,8. To address these challenges, we formulate a universal approach for mapping arbitrary networks to synthesized one-dimensional lattices with strictly local inhomogeneous couplings, where the dynamics at the excited site is exactly replicated. We present direct experimental observations in judiciously designed planar photonic structures, showcasing non-monotonic excitation decays associated with up to seven-dimensional hypercubic lattices, and demonstrate a novel sharp localization transition specific to four and higher dimensions. The unprecedented capability of experimentally exploring multi-dimensional dynamics and harnessing their unique features in one-dimensional lattices can find multiple applications in diverse physical systems, including photonic integrated circuits

    Serrulatane Diterpenoid from <i>Eremophila neglecta</i> Exhibits Bacterial Biofilm Dispersion and Inhibits Release of Pro-inflammatory Cytokines from Activated Macrophages

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    The purpose of this study was to assess the biofilm-removing efficacy and inflammatory activity of a serrulatane diterpenoid, 8-hydroxyserrulat-14-en-19-oic acid (<b>1</b>), isolated from the Australian medicinal plant <i>Eremophila neglecta.</i> Biofilm breakup activity of compound <b>1</b> on established <i>Staphylococcus epidermidis</i> and <i>Staphylococcus aureus</i> biofilms was compared to the antiseptic chlorhexidine and antibiotic levofloxacin. In a time-course study, <b>1</b> was deposited onto polypropylene mesh to mimic a wound dressing and tested for biofilm removal. The <i>ex-vivo</i> cytotoxicity and effect on lipopolysaccharide-induced pro-inflammatory cytokine release were studied in mouse primary bone-marrow-derived macrophage (BMDM) cells. Compound <b>1</b> was effective in dispersing 12 h pre-established biofilms with a 7 log<sub>10</sub> reduction of viable bacterial cell counts, but was less active against 24 h biofilms (approximately 2 log<sub>10</sub> reduction). Compound-loaded mesh showed dosage-dependent biofilm-removing capability. In addition, compound <b>1</b> displayed a significant inhibitory effect on tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) secretion from BMDM cells, but interleukin-1 beta (IL-1β) secretion was not significant. The compound was not cytotoxic to BMDM cells at concentrations effective in removing biofilm and lowering cytokine release. These findings highlight the potential of this serrulatane diterpenoid to be further developed for applications in wound management

    Local proliferation maintains a stable pool of tissue-resident memory T cells after antiviral recall responses

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    Although tissue-resident memory T cells (TRM cells) are critical in fighting infection, their fate after local pathogen re-encounter is unknown. Here we found that skin TRM cells engaged virus-infected cells, proliferated in situ in response to local antigen encounter and did not migrate out of the epidermis, where they exclusively reside. As a consequence, secondary TRM cells formed from pre-existing TRM cells, as well as from precursors recruited from the circulation. Newly recruited antigen-specific or bystander TRM cells were generated in the skin without displacement of the pre-existing TRM cell pool. Thus, pre-existing skin TRM cell populations are not displaced after subsequent infections, which enables multiple TRM cell specificities to be stably maintained within the tissue.S.L.P. was supported by the University of Melbourne (Elizabeth and Vernon Puzey Postgraduate Scholarship). T.G. was supported by a fellowship from the Sylvia and Charles Viertel Charitable Foundation. This work was supported by the National Health and Medical Research Council of Australia (to S.N.M. and L.K.M.) and the Australian Research Council (to S.N.M.)

    Individual and population quantitative analyses of calcium flux in T-cells activated on functionalized material surfaces

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    We have developed a novel method for activating T-cells on material surfaces that enable individual and population-based analyses of intracellular calcium flux, as a quantitative measure of T-cell receptor engagement. Functionalized material surfaces were created using a plasma-polymerized foundation layer to immobilize stimulatory T-cell ligands, which could induce T-cell receptor-dependent calcium flux in naive T-cells. Real-time confocal microscopic detection and quantification of calcium flux using paired fluorescent ratiometric probes facilitated the tracking and analysis of response profiles of individual T-cells, as well as population analyses using a combination of individual T-cell events. This type of combined analysis cannot be achieved using traditional population-based flow cytometric approaches, and thus provides a logical step towards developing the capacity to assess the magnitude and quality of inherently heterogeneous effector T-cell responses to antigenic challenge.Susan N. Christo, Ghafar. T. Sarvestani, Stefani S. Griesser, Bryan R. Coad, Hans J. Griesser, Krasimir Vasilev, Michael P. Brown, Kerrilyn R. Diener and John D. Haybal
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