2,326 research outputs found

    Impact of Resistance to Fluconazole on Virulence and Morphological Aspects of Cryptococcus neoformans and Cryptococcus gattii Isolates

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    Cryptococcus spp. are responsible for around one million cases of meningitis every year. Fluconazole (FLU) is commonly used in the treatment of cryptococcosis, mainly in immunocompromised patients and the resistance is usually reported after long periods of treatment. In this study, the morphological characterization and virulence profile of FLU-susceptible and FLU-resistant clinical and environmental isolates of C. neoformans and C. gattii were performed both in vitro and in vivo using the Galleria mellonella model. FLU-susceptible isolates from C. neoformans were significantly more virulent than the FLU-resistant isolates. FLU-susceptible C. gattii isolates showed a different virulence profile from C. neoformans isolates where only the environmental isolate, CL, was more virulent compared with the resistant isolates. Cell morphology and capsule size were analyzed and the FLU-resistant isolates did not change significantly compared with the most sensitive isolates. Growth at 37°C was also evaluated and in both species, the resistant isolates showed a reduced growth at this temperature, indicating that FLU resistance can affect their growth. Based on the results obtained is possible suggest that FLU resistance can influence the morphology of the isolates and consequently changed the virulence profiles. The most evident results were observed for C. neoformans showing that the adaptation of isolates to antifungal selective pressure influenced the loss of virulence

    Current concepts: tissue engineering and regenerative medicine applications in the ankle joint

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    Tissue engineering and regenerative medicine (TERM) has caused a revolution in present and future trends of medicine and surgery. In different tissues, advanced TERM approaches bring new therapeutic possibilities in either general population as in young patients and high-level athletes, improving restoration of biological functions and rehabilitation. The mainstream components required to obtain a functional regeneration of tissues may include biodegradable scaffolds, drugs or growth factors and different cell types (either autologous or heterologous) that can be cultured in bioreactor systems (in vitro) prior implantation into the patient. Particularly in the ankle, that is subject of many different injuries (e.g. acute, chronic, traumatic, degenerative), there is still no definitive and feasible answer to “conventional” methods. This review aims to provide current concepts of TERM applications to ankle injuries under pre-clinical and/or clinical research applied to skin, tendon, bone and cartilage problems. A particular attention has been given to biomaterials design and scaffolds processing with potential use in osteochondral ankle lesions.The authors acknowledge the Portuguese Foundation for Science and Technology (FCT) through the POCTI and FEDER programmes, including Project OsteoCart (grant no. PTDC/CTM-BPC/115977/2009) for providing funds

    An Intracellular Arrangement of Histoplasma capsulatum Yeast-Aggregates Generates Nuclear Damage to the Cultured Murine Alveolar Macrophages

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    Histoplasma capsulatum is responsible for a human systemic mycosis that primarily affects lung tissue. Macrophages are the major effector cells in humans that respond to the fungus, and the development of respiratory disease depends on the ability of Histoplasma yeast cells to survive and replicate within alveolar macrophages. Therefore, the interaction between macrophages and H. capsulatum is a decisive step in the yeast dissemination into host tissues. Although the role played by components of cell-mediated immunity in the host's defense system and the mechanisms used by the pathogen to evade the host immune response are well understood, knowledge regarding the effects induced by H. capsulatum in host cells at the nuclear level is limited. According to the present findings, H. capsulatum yeast cells display a unique architectural arrangement during the intracellular infection of cultured murine alveolar macrophages, characterized as a formation of aggregates that seem to surround the host cell nucleus, resembling a crown. This extranuclear organization of yeast-aggregates generates damage on the nucleus of the host cell, producing DNA fragmentation and inducing apoptosis, even though the yeast cells are not located inside the nucleus and do not trigger changes in nuclear proteins. The current study highlights a singular intracellular arrangement of H. capsulatum yeast near to the nucleus of infected murine alveolar macrophages that may contribute to the yeast’s persistence under intracellular conditions, since this fungal pathogen may display different strategies to prevent elimination by the host's phagocytic mechanisms

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    The Mitochondrial Ca(2+) Uniporter: Structure, Function, and Pharmacology.

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    Mitochondrial Ca(2+) uptake is crucial for an array of cellular functions while an imbalance can elicit cell death. In this chapter, we briefly reviewed the various modes of mitochondrial Ca(2+) uptake and our current understanding of mitochondrial Ca(2+) homeostasis in regards to cell physiology and pathophysiology. Further, this chapter focuses on the molecular identities, intracellular regulators as well as the pharmacology of mitochondrial Ca(2+) uniporter complex

    Effect of the Ethyl Acetate Fraction of Eugenia uniflora on Proteins Global Expression during Morphogenesis in Candida albicans

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    Candida albicans is able to switch from yeast to hyphal growth and this is an essential step for tissue invasion and establishment of infection. Due to the limited drug arsenal used to treat fungal infections and the constant emergence of resistant strains, it is important to search for new therapeutic candidates. Therefore, this study aimed to investigate by proteomic analysis the role of a natural product (Eugenia uniflora) in impairing hypha formation in C. albicans. We also tested the potential action of E. uniflora to prevent and treat oral candidiasis induced in a murine model of oral infection and the ability of polymorphonuclear neutrophils to phagocytize C. albicans cells treated with the ethyl acetate fraction of the extract. We found that this fraction greatly reduced hypha formation after morphogenesis induction in the presence of serum. Besides, several proteins were differentially expressed in cells treated with the fraction. Surprisingly, the ethyl acetate fraction significantly reduced phagocytosis in C. albicans (Mean 120.36 ± 36.71 yeasts/100 PMNs vs. 44.68 ± 19.84 yeasts/100 PMNs). Oral candidiasis was attenuated when C. albicans cells were either pre-incubated in the presence of E. uniflora or when the fraction was applied to the surface of the oral cavity after infection. These results were consistent with the reduction in CFU counts (2.36 vs. 1.85 Log10 CFU/ml) and attenuation of tissue damage observed with histopathological analysis of animals belonging to treated group. We also observed shorter true hyphae by direct examination and histopathological analysis, when cells were treated with the referred natural product. The E. uniflora ethyl acetate fraction was non-toxic to human cells. E. uniflora may act on essential proteins mainly related to cellular structure, reducing the capacity of filamentation and attenuating infection in a murine model, without causing any toxic effect on human cells, suggesting that it may be a future therapeutic alternative for the treatment of Candida infections

    A comparison of four fibrosis indexes in chronic HCV: Development of new fibrosis-cirrhosis index (FCI)

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    <p>Abstract</p> <p>Background</p> <p>Hepatitis C can lead to liver fibrosis and cirrhosis. We compared readily available non-invasive fibrosis indexes for the fibrosis progression discrimination to find a better combination of existing non-invasive markers.</p> <p>Methods</p> <p>We studied 157 HCV infected patients who underwent liver biopsy. In order to differentiate HCV fibrosis progression, readily available AAR, APRI, FI and FIB-4 serum indexes were tested in the patients. We derived a new fibrosis-cirrhosis index (FCI) comprised of ALP, bilirubin, serum albumin and platelet count. FCI = [(ALP × Bilirubin) / (Albumin × Platelet count)].</p> <p>Results</p> <p>Already established serum indexes AAR, APRI, FI and FIB-4 were able to stage liver fibrosis with correlation coefficient indexes 0.130, 0.444, 0.578 and 0.494, respectively. Our new fibrosis cirrhosis index FCI significantly correlated with the histological fibrosis stages F0-F1, F2-F3 and F4 (r = 0.818, p < 0.05) with AUROCs 0.932 and 0.996, respectively. The sensitivity and PPV of FCI at a cutoff value < 0.130 for predicting fibrosis stage F0-F1 was 81% and 82%, respectively with AUROC 0.932. Corresponding value of FCI at a cutoff value ≥1.25 for the prediction of cirrhosis was 86% and 100%.</p> <p>Conclusions</p> <p>The fibrosis-cirrhosis index (FCI) accurately predicted fibrosis stages in HCV infected patients and seems more efficient than frequently used serum indexes.</p

    Searches for exclusive Higgs and Z boson decays into J/ψγ,ψ(2S)γ,and Υ(nS)γ at √s=13 TeV with the ATLAS detector

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    Searches for the exclusive decays of the Higgs and Z bosons into a J/ψ,ψ(2S), or Υ(nS)(n=1,2,3) meson and a photon are performed with a pp collision data sample corresponding to an integrated luminosity of 36.1 fb −1 collected at √s =13 TeV with the ATLAS detector at the CERN Large Hadron Collider. No significant excess of events is observed above the expected backgrounds, and 95% confidence-level upper limits on the branching fractions of the Higgs boson decays to J/ψγ, ψ(2S)γ,and Υ(nS)γ of 3.5×10 −4, 2.0×10−3,and(4.9,5.9,5.7)×10 −4,respectively, are obtained assuming Standard Model production. The corresponding 95% confidence-level upper limits for the branching fractions of the Z boson decays are 2.3×10 −6, 4.5×10 −6 and (2.8,1.7,4.8)×10 −6, respectively
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