321 research outputs found

    CD-62°1346: An extreme halo or hypervelocity CH star?

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    High-velocity halo stars provide important information about the properties of the extreme Galactic halo. The study of unbound and bound Population II stars permits us to better estimate the mass of the halo. Aims: We carried out a detailed spectroscopic and kinematic study and have significantly refined the distance and the evolutionary state of the star. Methods: Its atmospheric parameters, chemical abundances and kinematical properties were determined using high-resolution optical spectroscopy and employing the local-thermodynamic-equilibrium model atmospheres of Kurucz and the spectral analysis code moog. Results: We found that CD-62°1346 is a metal-poor ([Fe/H] = -1.6) evolved giant star with Teff = 5300 K and log g = 1.7. The star exhibits high carbon and s-element abundances typical of CH stars. It is also a lead star. Our kinematic analysis of its 3D space motions shows that this star has a highly eccentric (e = 0.91) retrograde orbit with an apogalactic distance of ~100 kpc, exceeding by a factor of two the distance of the Magellanic Clouds. The star travels with very high velocity relative to the Galactocentric reference frame (VGRF = 570 km s-1). Conclusions: CD-62°1346 is an evolved giant star and not a subgiant star, as was considered earlier. Whether it is bound or unbound to the Galaxy depends on the assumed mass and on the adopted Galactic potential. We also show that the star HD 5223 is another example of a high-velocity CH star that exceeds the Galactic escape velocity. Possible origins of these two high-velocity stars are briefly discussed. CD-62°1346 and HD 5223 are the first red giant stars to join the restricted group of hypervelocity stars.Fil: Pereira, C. B.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Jilinski, E.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil. Universidade do Estado de Rio do Janeiro; Brasil. Russian Academy of Sciences. Pulkovo Observatory; RusiaFil: Drake, N. A.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil. Russian Academy of Sciences. Pulkovo Observatory; RusiaFil: de Castro, D. B.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Ortega, V. G.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Chavero, Carolina Andrea. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Roig, Fernando Virgilio. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasi

    Mechanical Ventilation and Clinical Outcomes in Patients with Acute Myocardial Infarction: A Retrospective Observational Study

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    Patients with acute myocardial infarction (AMI) and respiratory impairment may be treated with either invasive or non-invasive mechanical ventilation (MV). However, there has been little testing of non-invasive MV in the setting of AMI. Our objective was to evaluate the incidence and associated clinical outcomes of patients with AMI who were treated with non-invasive or invasive MV

    Antileishmanial activity of meroditerpenoids from the macroalgae Cystoseira baccata

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    The development of novel drugs for the treatment of leishmaniases continues to be crucial to overcome the severe impacts of these diseases on human and animal health. Several bioactivities have been described in extracts from macroalgae belonging to the Cystoseira genus. However, none of the studies has reported the chemical compounds responsible for the antileishmanial activity observed upon incubation of the parasite with the aforementioned extracts. Thus, this work aimed to isolate and characterize the molecules present in a hexane extract of Cystoseira baccata that was found to be bioactive against Leishmania infantum in a previous screening effort. A bioactivity-guided fractionation of the C. baccata extract was carried out and the inhibitory potential of the isolated compounds was evaluated via the MIT assay against promastigotes and murine macrophages as well as direct counting against intracellular amastigotes. Moreover, the promastigote ultrastructure, DNA fragmentation and changes in the mitochondrial potential were assessed to unravel their mechanism of action. In this process, two antileishmanial meroditerpenoids, (3R)- and (3S)-tetraprenyltoluquinol (1a/1b) and (3R)- and (3S)-tetraprenyltoluquinone (2a/2b), were isolated. Compounds 1 and 2 inhibited the growth of the L. infantum promastigotes (IC50 = 44.9 +/- 4.3 and 94.4 +/- 10.1 mu M, respectively), inducing cytoplasmic vacuolization and the presence of coiled multilamellar structures in mitochondria as well as an intense disruption of the mitochondrial membrane potential. Compound 1 decreased the intracellular infection index (IC50 = 25.0 +/- 4.1 mu M), while compound 2 eliminated 50% of the intracellular amastigotes at a concentration > 88.0 mu M. This work identified compound 2 as a novel metabolite and compound 1 as a biochemical isolated from Cystoseira algae displaying antileishmanial activity. Compound 1 can thus be an interesting scaffold for the development of novel chemotherapeutic molecules for canine and human visceral leishmaniases studies. This work reinforces the evidence of the marine environment as source of novel molecules. (C) 2017 Elsevier Inc. All rights reserved.Portuguese FCT CCMAR/Multi/04326/2013FAPESP [2013/16297-2, 2015/11936-2]CNPq [470853/2012-3]FCT doctoral grants [ SFRH/BD/105541/2014 ]FCT Investigator Programme [IF/00049/2012]info:eu-repo/semantics/publishedVersio

    Species-Specific Diversity of a Fixed Motor Pattern: The Electric Organ Discharge of Gymnotus

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    Understanding fixed motor pattern diversity across related species provides a window for exploring the evolution of their underlying neural mechanisms. The electric organ discharges of weakly electric fishes offer several advantages as paradigmatic models for investigating how a neural decision is transformed into a spatiotemporal pattern of action. Here, we compared the far fields, the near fields and the electromotive force patterns generated by three species of the pulse generating New World gymnotiform genus Gymnotus. We found a common pattern in electromotive force, with the far field and near field diversity determined by variations in amplitude, duration, and the degree of synchronization of the different components of the electric organ discharges. While the rostral regions of the three species generate similar profiles of electromotive force and local fields, most of the species-specific differences are generated in the main body and tail regions of the fish. This causes that the waveform of the field is highly site dependant in all the studied species. These findings support a hypothesis of the relative separation of the electrolocation and communication carriers. The presence of early head negative waves in the rostral region, a species-dependent early positive wave at the caudal region, and the different relationship between the late negative peak and the main positive peak suggest three points of lability in the evolution of the electrogenic system: a) the variously timed neuronal inputs to different groups of electrocytes; b) the appearance of both rostrally and caudally innervated electrocytes, and c) changes in the responsiveness of the electrocyte membrane

    The germline mutational landscape of BRCA1 and BRCA2 in Brazil

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    The detection of germline mutations in BRCA1 and BRCA2 is essential to the formulation of clinical management strategies, and in Brazil, there is limited access to these services, mainly due to the costs/availability of genetic testing. Aiming at the identification of recurrent mutations that could be included in a low-cost mutation panel, used as a first screening approach, we compiled the testing reports of 649 probands with pathogenic/likely pathogenic variants referred to 28 public and private health care centers distributed across 11 Brazilian States. Overall, 126 and 103 distinct mutations were identified in BRCA1 and BRCA2, respectively. Twenty-six novel variants were reported from both genes, and BRCA2 showed higher mutational heterogeneity. Some recurrent mutations were reported exclusively in certain geographic regions, suggesting a founder effect. Our findings confirm that there is significant molecular heterogeneity in these genes among Brazilian carriers, while also suggesting that this heterogeneity precludes the use of screening protocols that include recurrent mutation testing only. This is the first study to show that profiles of recurrent mutations may be unique to different Brazilian regions. These data should be explored in larger regional cohorts to determine if screening with a panel of recurrent mutations would be effective.This work was supported in part by grants from Barretos Cancer Hospital (FINEP - CT-INFRA, 02/2010), Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, 2013/24633-2 and 2103/23277-8), Fundação de Apoio à Pesquisa do Rio Grande do Norte (FAPERN), Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS), Ministério da Saúde, the Breast Cancer Research Foundation (Avon grant #02-2013-044) and National Institute of Health/National Cancer Institute (grant #RC4 CA153828-01) for the Clinical Cancer Genomics Community Research Network. Support in part was provided by grants from Fundo de Incentivo a Pesquisa e Eventos (FIPE) from Hospital de Clínicas de Porto Alegre, by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, BioComputacional 3381/2013, Rede de Pesquisa em Genômica Populacional Humana), Secretaria da Saúde do Estado da Bahia (SESAB), Laboratório de Imunologia e Biologia Molecular (UFBA), INCT pra Controle do Câncer and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). RMR and PAP are recipients of CNPq Productivity Grants, and Bárbara Alemar received a grant from the same agencyinfo:eu-repo/semantics/publishedVersio

    Combined Treatment of Heterocyclic Analogues and Benznidazole upon Trypanosoma cruzi In Vivo

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    Chagas disease caused by Trypanosoma cruzi is an important cause of mortality and morbidity in Latin America but no vaccines or safe chemotherapeutic agents are available. Combined therapy is envisioned as an ideal approach since it may enhance efficacy by acting upon different cellular targets, may reduce toxicity and minimize the risk of drug resistance. Therefore, we investigated the activity of benznidazole (Bz) in combination with the diamidine prodrug DB289 and in combination with the arylimidamide DB766 upon T. cruzi infection in vivo. The oral treatment of T.cruzi-infected mice with DB289 and Benznidazole (Bz) alone reduced the number of circulating parasites compared with untreated mice by about 70% and 90%, respectively. However, the combination of these two compounds decreased the parasitemia by 99% and protected against animal mortality by 100%, but without providing a parasitological cure. When Bz (p.o) was combined with DB766 (via ip route), at least a 99.5% decrease in parasitemia levels was observed. DB766+Bz also provided 100% protection against mice mortality while Bz alone provided about 87% protection. This combined therapy also reduced the tissular lesions induced by T. cruzi infection: Bz alone reduced GPT and CK plasma levels by about 12% and 78% compared to untreated mice group, the combination of Bz with DB766 resulted in a reduction of GPT and CK plasma levels of 56% and 91%. Cure assessment through hemocultive and PCR approaches showed that Bz did not provide a parasitological cure, however, DB766 alone or associated with Bz cured ≥13% of surviving animals

    Integral strategy to supportive care in breast cancer survivors through occupational therapy and a m-health system: design of a randomized clinical trial

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    Background: Technological support using e-health mobile applications (m-health) is a promising strategy to improve the adherence to healthy lifestyles in breast cancer survivors (excess in energy intake or low physical activity are determinants of the risk of recurrence, second cancers and cancer mortality). Moreover, cancer rehabilitation programs supervised by health professionals are needed due to the inherent characteristics of these breast cancer patients. Our main objective is to compare the clinical efficacy of a m-health lifestyle intervention system alone versus an integral strategy to improve Quality of Life in breast cancer survivors. Methods: This therapeutic superiority study will use a two-arm, assessor blinded parallel RCT design. Women will be eligible if: they are diagnosed of stage I, II or III-A breast cancer; are between 25 and 75 years old; have a Body Mass Index > 25 kg/m2; they have basic ability to use mobile apps; they had completed adjuvant therapy except for hormone therapy; and they have some functional shoulder limitations. Participants will be randomized to one of the following groups: integral group will use a mobile application (BENECA APP) and will receive a face-to-face rehabilitation (8-weeks); m-health group will use the BENECA app for 2-months and will received usual care information. Study endpoints will be assessed after 8 weeks and 6 months. The primary outcome will be Quality of Life measured by The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core and breast module. The secondary outcomes: body composition; upper-body functionality (handgrip, Disability of the Arm, Shoulder and Hand questionnaire, goniometry); cognitive function (Wechsler Adult Intelligence Scale, Trail Making Test); anxiety and depression (Hospital Anxiety and Depression Scale); physical fitness (Short version of the Minnesota Leisure Time Physical Activity Questionnaire, Self-Efficacy Scale for Physical Activity); accelerometry and lymphedema. Discussion: This study has been designed to seek to address the new needs for support and treatment of breast cancer survivors, reflecting the emerging need to merge new low cost treatment options with much-needed involvement of health professionals in this type of patients. Trial registration: ClinicalTrials.gov Identifier: NCT02817724 (date of registration: 22/06/2016).The study was funded by the Spanish Ministry of Economy and Competitiveness (Plan Estatal de I + D + I 2013-2016), Fondo de Investigación Sanitaria del Instituto de Salud Carlos III (PI14/01627), Fondos Estructurales de la Unión Europea (FEDER) and by the Spanish Ministry of Education (FPU14/01069). This is part of a Ph.D. Thesis conducted in the Clinical Medicine and Public Health Doctoral Studies of the University of Granada, Spain

    Multiple effects of toxins isolated from Crotalus durissus terrificus on the hepatitis C virus life cycle

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    Hepatitis C virus (HCV) is one of the main causes of liver disease and transplantation worldwide. Current therapy is expensive, presents additional side effects and viral resistance has been described. Therefore, studies for developing more efficient antivirals against HCV are needed. Compounds isolated from animal venoms have shown antiviral activity against some viruses such as Dengue virus, Yellow fever virus and Measles virus. In this study, we evaluated the effect of the complex crotoxin (CX) and its subunits crotapotin (CP) and phospholipase A2 (PLA2-CB) isolated from the venom of Crotalus durissus terrificus on HCV life cycle. Huh 7.5 cells were infected with HCVcc JFH-1 strain in the presence or absence of these toxins and virus was titrated by focus formation units assay or by qPCR. Toxins were added to the cells at different time points depending on the stage of virus life cycle to be evaluated. The results showed that treatment with PLA2-CB inhibited HCV entry and replication but no effect on HCV release was observed. CX reduced virus entry and release but not replication. By treating cells with CP, an antiviral effect was observed on HCV release, the only stage inhibited by this compound. Our data demonstrated the multiple antiviral effects of toxins from animal venoms on HCV life cycle

    Impaired Innate Immunity in Tlr4−/− Mice but Preserved CD8+ T Cell Responses against Trypanosoma cruzi in Tlr4-, Tlr2-, Tlr9- or Myd88-Deficient Mice

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    The murine model of T. cruzi infection has provided compelling evidence that development of host resistance against intracellular protozoans critically depends on the activation of members of the Toll-like receptor (TLR) family via the MyD88 adaptor molecule. However, the possibility that TLR/MyD88 signaling pathways also control the induction of immunoprotective CD8+ T cell-mediated effector functions has not been investigated to date. We addressed this question by measuring the frequencies of IFN-γ secreting CD8+ T cells specific for H-2Kb-restricted immunodominant peptides as well as the in vivo Ag-specific cytotoxic response in infected animals that are deficient either in TLR2, TLR4, TLR9 or MyD88 signaling pathways. Strikingly, we found that T. cruzi-infected Tlr2−/−, Tlr4−/−, Tlr9−/− or Myd88−/− mice generated both specific cytotoxic responses and IFN-γ secreting CD8+ T cells at levels comparable to WT mice, although the frequency of IFN-γ+CD4+ cells was diminished in infected Myd88−/− mice. We also analyzed the efficiency of TLR4-driven immune responses against T. cruzi using TLR4-deficient mice on the C57BL genetic background (B6 and B10). Our studies demonstrated that TLR4 signaling is required for optimal production of IFN-γ, TNF-α and nitric oxide (NO) in the spleen of infected animals and, as a consequence, Tlr4−/− mice display higher parasitemia levels. Collectively, our results indicate that TLR4, as well as previously shown for TLR2, TLR9 and MyD88, contributes to the innate immune response and, consequently, resistance in the acute phase of infection, although each of these pathways is not individually essential for the generation of class I-restricted responses against T. cruzi
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