897 research outputs found

    Growth hormone plus resistance exercise attenuate structural changes in rat myotendinous junctions resulting from chronic unloading.

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    Myotendinous junctions (MTJs) are specialized sites on the muscle surface where forces generated by myofibrils are transmitted across the sarcolemma to the extracellular matrix. At the ultrastructural level, the interface between the sarcolemma and extracellular matrix is highly folded and interdigitated at these junctions. In this study, the effect of exercise and growth hormone (GH) treatments on the changes in MTJ structure that occur during muscle unloading, has been analyzed. Twenty hypophysectomized rats were assigned randomly to one of five groups: ambulatory control, hindlimb unloaded, hindlimb unloaded plus exercise (3 daily bouts of 10 climbs up a ladder with 50% body wt attached to the tail), hindlimb unloaded plus GH (2 daily injections of 1 mg/kg body wt, i.p.), and hindlimb unloaded plus exercise plus GH. MTJs of the plantaris muscle were analyzed by electron microscopy and the contact between muscle and tendon was evaluated using an IL/B ratio, where B is the base and IL is the interface length of MTJ's digit-like processes. After 10 days of unloading, the mean IL/B ratio was significantly lower in unloaded (3.92), unloaded plus exercise (4.18), and unloaded plus GH (5.25) groups than in the ambulatory control (6.39) group. On the opposite, the mean IL/B ratio in the group treated with both exercise and GH (7.3) was similar to control. These findings indicate that the interaction between exercise and GH treatments attenuates the changes in MTJ structure that result from chronic unloading and thus can be used as a countermeasure to these adaptations

    MODELING the INTERACTION BETWEEN AIDS and TUBERCULOSIS

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    A deterministic model is proposed for the study of the dynamics of acquired immunodeficiency syndrome (AIDS) and tuberculosis (TB) co-infection. the model is comprised by a set of sixteen ordinary differential equations representing different states of both diseases, and it is intended to provide a theoretical framework for the study of the interaction between both infections. Numerical simulations of the model resulted in three striking outcomes: first, the pathogenicity of Human Immunodeficiency Virus (HIV) is enhanced by the presence of TB, and vice-versa; second, the prevalence of AIDS is higher in the presence of TB; and third, relative risk analysis demonstrated a much stronger influence of AIDS on TB than the other way around.ESCOLA PAULISTA MED,BR-04023 São Paulo,BRAZILUNIV São Paulo,INST PHYS,São Paulo,BRAZILHCFMUSP,BR-01246 São Paulo,BRAZILESCOLA PAULISTA MED,BR-04023 São Paulo,BRAZILWeb of Scienc

    Modelisation of transition and noble metal vicinal surfaces: energetics, vibrations and stability

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    The energetics of transition and noble metal (Rh, Pd, Cu) vicinal surfaces, i.e., surface energy, step energy, kink energy and electronic interactions between steps, is studied at 0K from electronic structure calculations in the tight-binding approximation using a {\it s, p} and {\it d} valence orbital basis set. Then, the surface phonon spectra of copper are investigated in the harmonic approximation with the help of a semi-empirical inter-atomic potential. This allows to derive the contribution of phonons at finite temperatures to the step free energy and to the interactions between steps. The last part is devoted to the stability of vicinal surfaces relative to faceting with special attention to the domain of orientations (100)-(111). Semi-empirical potentials are shown to be not realistic enough to give a reliable answer to this problem. The results derived from electronic structure calculations predict a variety of behaviors and, in particular, a possible faceting into two other vicinal orientations. Finally, temperature effects are discussed. Comparisons are made with other theoretical works and available experiments

    Angiogenesis genotyping in the selection of first-line treatment with either sunitinib or pazopanib for advanced renal cell carcinoma

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    Recent data from the COMPARZ study seem to suggest a noninferiority of pazopanib confronted with sunitinib in PFS and OS. We previously reported how VEGF and VEGFR polymorphisms might have a predictive role in patients treated with first-line sunitinib. Aim of our study was to investigate whether tumour angiogenesis genotyping could influence clinical outcome in RCC patients treated with either sunitinib or pazopanib, in order to help clinicians select the appropriate treatment for each patient. Results: 19 patients were treated with pazopanib while 78 received sunitinib. VEGF A rs833061 resulted significant in PFS in sunitinib vs pazopanib patients (CC+CT > TT in sunitinib, TT > CC+CT in pazopanib; p CC in sunitinib, CC > GG+CG in pazopanib; p CC in sunitinib, CC > AA+AC in pazopanib; p < 0,0001). OS showed no statistically significant difference. Conclusions: In our analysis patients with opposite polymorphisms of rs833061, rs2010963, rs699947 of VEGF A seems to have a better PFS if treated with either sunitinib or pazopanib. Our data seem to suggest that biology could have a role choosing first line treatment for mRCC patients. Methods: A retrospective analysis on 97 histologic samples of mRCC patients was conducted for VEGF-A, VEGF-C and VEGFR-1,2,3 single nucleotide polymorphisms (SNPs

    Magnitude and frequency variations of vector-borne infection outbreaks using the Ross–Macdonald model : explaining and predicting outbreaks of dengue fever

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    The classical Ross–Macdonald model is often utilized to model vector-borne infections; however, this model fails on several fronts. First, using measured (or estimated) parameters, which values are accepted from the literature, the model predicts a much greater number of cases than what is usually observed. Second, the model predicts a single large outbreak that is followed by decades of much smaller outbreaks, which is not consistent with what is observed. Usually towns or cities report a number of recurrences for many years, even when environmental changes cannot explain the disappearance of the infection between the peaks. In this paper, we continue to examine the pitfalls in modelling this class of infections, and explain that, if properly used, the Ross–Macdonald model works and can be used to understand the patterns of epidemics and even, to some extent, be used to make predictions.We model several outbreaks of dengue fever and show that the variable pattern of yearly recurrence (or its absence) can be understood and explained by a simple Ross–Macdonald model modified to take into account human movement across a range of neighbourhoods within a city. In addition, we analyse the effect of seasonal variations in the parameters that determine the number, longevity and biting behaviour of mosquitoes. Based on the size of the first outbreak, we show that it is possible to estimate the proportion of the remaining susceptible individuals and to predict the likelihood and magnitude of the eventual subsequent outbreaks. This approach is described based on actual dengue outbreaks with different recurrence patterns from some Brazilian regions

    Visceral leishmaniasis in the State of Maranhão, Brazil: evolution of an epidemic

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    The authors provide a brief report on the historical evolution of visceral leishmaniasis in the State of Maranhão, Brazil, evaluating possible factors for growth of the disease in the State and control measures by the Brazilian Ministry of Health to integrate health services finto the maintenance of control programs.Os autores fazem um breve relato da evolução histórica da leishmaniose visceral no Estado do Maranhão, Brasil, avaliando as possíveis causas da expansão da referida doença no Estado, assim como as medidas de controle adotadas pelo Ministério da Saúde objetivando a diminuição da incidência da mesma.Universidade Federal do Maranhão Faculdade de Medicina Departamento de PatologiaEscola Paulista de MedicinaUNIFESP, EPMSciEL

    Three-dimensional apoptotic nuclear behavior analyzed by means of field emission in lens scanning electron microscope

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    Apoptosis is an essential biological function required during embryogenesis, tissue homeostasis, organ development and immune system regulation. It is an active cell death pathway involved in a variety of pathological conditions. During this process cytoskeletal proteins appear damaged and undergo an enzymatic disassembling, leading to formation of apoptotic features. This study was designed to examine the threedimensional chromatin behavior and cytoskeleton involvement, in particular actin re-modeling. HL-60 cells, exposed to hyperthermia, a known apoptotic trigger, were examined by means of a Field Emission in Lens Scanning Electron Microscope (FEISEM). Ultrastructural observations revealed in treated cells the presence of apoptotic patterns after hyperthermia trigger. In particular, three-dimensional apoptotic chromatin rearrangements appeared involving the translocation of filamentous actin from cytoplasm to the nucleus. FEISEM immunogold techniques showed actin labeling and its precise three-dimensional localization in the diffuse chromatin, well separated from the condensed one. The actin presence in dispersed chromatin inside the apoptotic nucleus can be considered an important feature, indispensable to permit the apoptotic machinery evolution

    Short-term economic impact of the Zika virus outbreak

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    Summary Zika virus (ZIKV) is mainly transmitted by mosquitoes bites. However, transmission by sexual contacts has been reported in 11 non endemic countries. The rapid spread of ZIKV in Latin American and Caribbean Countries (LCR), person-to-person transmission and perceived risk on people’s well being can affect the emerging economies of LCR which historically dependent on truism. Here we present an analysis on economic outputs for assessing the current impact of ZIKV on markets. Our analysis show an unexpected resilience of LCR markets to international alerts. This positive response represents an opportunity to scale-up interventions for preventing the further spreading of the ZIKV epidemic

    Towards Linked Data for Ecosystems of Digital Twins

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    Due to either the inherent complexity of the domain or the evolving nature of systems, we can envision solutions that digitalize assets in a complex domain using an ecosystem of distributed Digital Twins instead of a single monolithic one. To effectively tackle interoperability in such ecosystems, this paper advocates for the introduction of a representation based on Semantic Web technologies enabling the discovery of both Digital Twin structure – i.e. the static information about the asset model and offered services – and state – i.e. the data and metrics collected at runtime – to support the management of ecosystems and the creation of application mashups. A review of the state of the art suggests that currently investigated ways to describe a Digital Twin are not sufficient to achieve this objective. A proposal of key requirements for a Digital Twin representation is outlined leading to the proposal of a core ontology and a Linked Data approach for state management
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