129 research outputs found

    Advances in the diagnosis and therapy of liver cirrhosis: a systematic review / Avanços no diagnóstico e terapia da cirrose hepática: uma revisão sistemática

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    Hepatic cirrhosis (HC) is a diffuse pathophysiological state of the liver considered to be the end-stage of several liver injuries. It is essential to highlight the need to implement new diagnostic and treatment methods to contain subsequent damage to liver cirrhosis, so that we can better understand the pathophysiological process of the disease and obtain better therapeutic results. Thus, this study aimed to identify advances in diagnostic methods and treatments for liver cirrhosis. This is a systematic literature review study, conducted by searching the descriptors “Liver cirrhosis”, “Alcoholic liver cirrhosis”, “Liver fibrosis” and “Liver”, in the databases: Scielo- Scientific Electronic Library Online, Lilacs - Latin American and Caribbean Center on Health Sciences Information, NIH-NCBI-Pubmed- National Center for Biotechnological Information – National Library of Medicine, following a search strategy according to descriptors in Portuguese and English, years 2015 to 2021. At the end of the search with the descriptors, 835 articles were found in the databases, of which 88 were in the Scielo platform, 286 in Lilacs and 461 in Pubmed. After the three selection steps, 811 articles were excluded and 23 articles that met the inclusion and exclusion criteria were selected for analysis. Based on this systematic review, it is pointed out that there has been a lot of development regarding the diagnosis and treatment of cirrhosis that, for many years, required scientific evidence to combat morbidity and mortality and reverse the condition of liver cirrhosis

    Strain-engineered graphene grown on hexagonal boron nitride by molecular beam epitaxy

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    Graphene grown by high temperature molecular beam epitaxy on hexagonal boron nitride (hBN) forms continuous domains with dimensions of order 20 μm, and exhibits moiré patterns with large periodicities, up to ~30 nm, indicating that the layers are highly strained. Topological defects in the moiré patterns are observed and attributed to the relaxation of graphene islands which nucleate at different sites and subsequently coalesce. In addition, cracks are formed leading to strain relaxation, highly anisotropic strain fields, and abrupt boundaries between regions with different moiré periods. These cracks can also be formed by modification of the layers with a local probe resulting in the contraction and physical displacement of graphene layers. The Raman spectra of regions with a large moiré period reveal split and shifted G and 2D peaks confirming the presence of strain. Our work demonstrates a new approach to the growth of epitaxial graphene and a means of generating and modifying strain in graphene

    Gestão democrática e participativa: sua relevância no contexto educacional / Democratic and participative management: its relevance in the educational context

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    As interlocuções deste escrito objetivam compreender a relevância da gestão democrática e participativa no campo educacional. Tal pesquisa é fundamentada com embasamentos teóricos de autores que tratam da referida temática, tais como; Libâneo (2008) e Lück (2009), além da legislação em vigor, mais especificamente o que preconiza a Lei de Diretrizes e Bases da Educação Nacional, nº 9.394/96, e da Constituição Federal de 1988. Conclui-se que preceitos legais e os ideais teóricos dos autores estudados concorrem para ampliar a importância do modelo de gestão democrática e participativa, tão basilar para o fomento de uma educação dialógica e partilhada.

    Leptospira interrogans Stably Infects Zebrafish Embryos, Altering Phagocyte Behavior and Homing to Specific Tissues

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    Leptospirosis is an extremely widespread zoonotic infection with outcomes ranging from subclinical infection to fatal Weil's syndrome. Despite the global impact of the disease, key aspects of its pathogenesis remain unclear. To examine in detail the earliest steps in the host response to leptospires, we used fluorescently labelled Leptospira interrogans serovar Copenhageni to infect 30 hour post fertilization zebrafish embryos by either the caudal vein or hindbrain ventricle. These embryos have functional innate immunity but have not yet developed an adaptive immune system. Furthermore, they are optically transparent, allowing direct visualization of host–pathogen interactions from the moment of infection. We observed rapid uptake of leptospires by phagocytes, followed by persistent, intracellular infection over the first 48 hours. Phagocytosis of leptospires occasionally resulted in formation of large cellular vesicles consistent with apoptotic bodies. By 24 hours, clusters of infected phagocytes were accumulating lateral to the dorsal artery, presumably in early hematopoietic tissue. Our observations suggest that phagocytosis may be a key defense mechanism in the early stages of leptospirosis, and that phagocytic cells play roles in immunopathogenesis and likely in the dissemination of leptospires to specific target tissues

    Investigating the use of 3-D full-waveform inversion to characterize the host rock at a geological disposal site

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    The U.K. government has a policy to dispose of higher activity radioactive waste in a geological disposal facility (GDF), which will have multiple protective barriers to keep the waste isolated and to ensure no harmful quantities of radioactivity are able to reach the surface. Currently no specific GDF site in the United Kingdom has been chosen but, once it has, the site is likely to be investigated using seismic methods. In this study, we explore whether 3-D full-waveform inversion (FWI) of seismic data can be used to map changes in physical properties caused by the construction of the site, specifically tunnel-induced fracturing. We have built a synthetic model for a GDF located in granite at 1000 m depth below the surface, since granite is one of the candidate host rocks due to its high strength and low permeability and the GDF could be located at such a depth. We use an effective medium model to predict changes in P-wave velocity associated with tunnel-induced fracturing, within the spatial limits of an excavated disturbed zone (EdZ), modelled here as an increase in fracture density around the tunnel. We then generate synthetic seismic data using a number of different experimental geometries to investigate how they affect the performance of FWI in recovering subsurface P-wave velocity structure. We find that the location and velocity of the EdZ are recovered well, especially when data recorded on tunnel receivers are included in the inversion. Our findings show that 3-D FWI could be a useful tool for characterizing the subsurface and changes in fracture properties caused during construction, and make a suite of suggestions on how to proceed once a potential GDF site has been identified and the geological setting is known

    A Novel High-Throughput Vaccinia Virus Neutralization Assay and Preexisting Immunity in Populations from Different Geographic Regions in China

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    Background: Pre-existing immunity to Vaccinia Tian Tan virus (VTT) resulting from a large vaccination campaign against smallpox prior to the early 1980s in China, has been a major issue for application of VTT-vector based vaccines. It is essential to establish a sensitive and high-throughput neutralization assay to understand the epidemiology of Vaccinia-specific immunity in current populations in China. Methodology/Principal Findings: A new anti-Vaccinia virus (VACV) neutralization assay that used the attenuated replication-competent VTT carrying the firefly luciferase gene of Photinus pyralis (rTV-Fluc) was established and standardized for critical parameters that included the choice of cell line, viral infection dose, and the infection time. The current study evaluated the maintenance of virus-specific immunity after smallpox vaccination by conducting a non-randomized, crosssectional analysis of antiviral antibody-mediated immune responses in volunteers examined 30–55 years after vaccination. The rTV-Fluc neutralization assay was able to detect neutralizing antibodies (NAbs) against Vaccinia virus without the ability to differentiate strains of Vaccinia virus. We showed that the neutralizing titers measured by our assay were similar to those obtained by the traditional plaque reduction neutralization test (PRNT). Using this assay, we found a low prevalence of NAb to VTT (7.6%) in individuals born before 1980 from Beijing and Anhui provinces in China, and when present, anti-VTT NAb titers were low. No NAbs were detected in all 222 samples from individuals born after 1980. There was no significan

    PIM2 Induced COX-2 and MMP-9 Expression in Macrophages Requires PI3K and Notch1 Signaling

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    Activation of inflammatory immune responses during granuloma formation by the host upon infection of mycobacteria is one of the crucial steps that is often associated with tissue remodeling and breakdown of the extracellular matrix. In these complex processes, cyclooxygenase-2 (COX-2) plays a major role in chronic inflammation and matrix metalloproteinase-9 (MMP-9) significantly in tissue remodeling. In this study, we investigated the molecular mechanisms underlying Phosphatidyl-myo-inositol dimannosides (PIM2), an integral component of the mycobacterial envelope, triggered COX-2 and MMP-9 expression in macrophages. PIM2 triggers the activation of Phosphoinositide-3 Kinase (PI3K) and Notch1 signaling leading to COX-2 and MMP-9 expression in a Toll-like receptor 2 (TLR2)-MyD88 dependent manner. Notch1 signaling perturbations data demonstrate the involvement of the cross-talk with members of PI3K and Mitogen activated protein kinase pathway. Enforced expression of the cleaved Notch1 in macrophages induces the expression of COX-2 and MMP-9. PIM2 triggered significant p65 nuclear factor -κB (NF-κB) nuclear translocation that was dependent on activation of PI3K or Notch1 signaling. Furthermore, COX-2 and MMP-9 expression requires Notch1 mediated recruitment of Suppressor of Hairless (CSL) and NF-κB to respective promoters. Inhibition of PIM2 induced COX-2 resulted in marked reduction in MMP-9 expression clearly implicating the role of COX-2 dependent signaling events in driving the MMP-9 expression. Taken together, these data implicate PI3K and Notch1 signaling as obligatory early proximal signaling events during PIM2 induced COX-2 and MMP-9 expression in macrophages

    Primary DNA damage and genetic polymorphisms for CYP1A1, EPHX and GSTM1 in workers at a graphite electrode manufacturing plant

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    <p>Abstract</p> <p>Background</p> <p>The results of a cross-sectional study aimed to evaluate whether genetic polymorphisms (biomarkers of susceptibility) for <it>CYP1A1</it>, <it>EPHX </it>and <it>GSTM1 </it>genes that affect polycyclic aromatic hydrocarbons (PAH) activation and detoxification might influence the extent of primary DNA damage (biomarker of biologically effective dose) in PAH exposed workers are presented. PAH-exposure of the study populations was assessed by determining the concentration of 1-hydroxypyrene (1OHP) in urine samples (biomarker of exposure dose).</p> <p>Methods</p> <p>The exposed group consisted of workers (n = 109) at a graphite electrode manufacturing plant, occupationally exposed to PAH. Urinary 1OHP was measured by HPLC. Primary DNA damage was evaluated by the alkaline comet assay in peripheral blood leukocytes. Genetic polymorphisms for <it>CYP1A1</it>, <it>EPHX</it> and <it>GSTM1</it> were determined by PCR or PCR/RFLP analysis.</p> <p>Results</p> <p>1OHP and primary DNA damage were significantly higher in electrode workers compared to reference subjects. Moreover, categorization of subjects as normal or outlier highlighted an increased genotoxic risk OR = 2.59 (CI95% 1.32–5.05) associated to exposure to PAH. Polymorphisms in <it>EPHX</it> exons 3 and 4 was associated to higher urinary concentrations of 1OHP, whereas none of the genotypes analyzed (<it>CYP1A1</it>, <it>EPHX</it>, and <it>GSTM1</it>) had any significant influence on primary DNA damage as evaluated by the comet assay.</p> <p>Conclusion</p> <p>The outcomes of the present study show that molecular epidemiology approaches (i.e. cross-sectional studies of genotoxicity biomarkers) can play a role in identifying common genetic risk factors, also attempting to associate the effects with measured exposure data. Moreover, categorization of subjects as normal or outlier allowed the evaluation of the association between occupational exposure to PAH and DNA damage highlighting an increased genotoxic risk.</p

    Phosphodiesterase-4 Inhibition Alters Gene Expression and Improves Isoniazid – Mediated Clearance of Mycobacterium tuberculosis in Rabbit Lungs

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    Tuberculosis (TB) treatment is hampered by the long duration of antibiotic therapy required to achieve cure. This indolent response has been partly attributed to the ability of subpopulations of less metabolically active Mycobacterium tuberculosis (Mtb) to withstand killing by current anti-TB drugs. We have used immune modulation with a phosphodiesterase-4 (PDE4) inhibitor, CC-3052, that reduces tumor necrosis factor alpha (TNF-α) production by increasing intracellular cAMP in macrophages, to examine the crosstalk between host and pathogen in rabbits with pulmonary TB during treatment with isoniazid (INH). Based on DNA microarray, changes in host gene expression during CC-3052 treatment of Mtb infected rabbits support a link between PDE4 inhibition and specific down-regulation of the innate immune response. The overall pattern of host gene expression in the lungs of infected rabbits treated with CC-3052, compared to untreated rabbits, was similar to that described in vitro in resting Mtb infected macrophages, suggesting suboptimal macrophage activation. These alterations in host immunity were associated with corresponding down-regulation of a number of Mtb genes that have been associated with a metabolic shift towards dormancy. Moreover, treatment with CC-3052 and INH resulted in reduced expression of those genes associated with the bacterial response to INH. Importantly, CC-3052 treatment of infected rabbits was associated with reduced ability of Mtb to withstand INH killing, shown by improved bacillary clearance, from the lungs of co-treated animals compared to rabbits treated with INH alone. The results of our study suggest that changes in Mtb gene expression, in response to changes in the host immune response, can alter the responsiveness of the bacteria to antimicrobial agents. These findings provide a basis for exploring the potential use of adjunctive immune modulation with PDE4 inhibitors to enhance the efficacy of existing anti-TB treatment
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