267 research outputs found

    Contribution of the FeoB transporter to Streptococcus suis virulence

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    The contribution of iron transporter systems encoded by feo genes to the pathogenic traits of streptococci is largely unknown, despite the fact that those systems are required for the full virulence of several gram-negative bacterial species. In this work, we show that the swine pathogen and zoonotic agent Streptococcus suis has a feoAB operon similar to that encoding an iron transporter system in Escherichia coli. Electrophoretic mobility assays and transcriptional analyses confirmed that the expression of S. suis feo genes is under the negative control of the ferric uptake regulator (Fur) protein. In vivo trials in mice using a feoB defective mutant strain were carried out to investigate the contribution of this gene to the virulence of S. suis. The results showed that the median lethal dose (LD50) of the mutant was approximately 10-fold higher than that of the wild-type parent strain. These data suggest that the Feo metal transporter plays a significant role in streptococcal infectious disease. This is in contrast to previous results reported for this same gene in other gram-positive bacterial species. [Int Microbiol 2009; 12(2):137-141

    Electrospun nanofibers of polyCD/PMAA polymers and their potential application as drug delivery system

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    Herein, we used an electrospinning process to develop highly efficacious and hydrophobic coaxial nanofibers based on poly-cyclodextrin (polyCD) associated with poly(methacrylic acid) (PMAA) that combines polymeric and supramolecular features for modulating the release of the hydrophilic drug, propranolol hydrochloride (PROP). For this purpose, polyCD was synthesized and characterized, and its biocompatibility was assessed using fibroblast cytotoxicity tests. Moreover, the interactions between the guest PROP molecule and both polyCD and ÎČ\betaCD were found to be spontaneous. Subsequently, PROP was encapsulated in uniaxial and coaxial polyCD/ PMAA nanofibers. A lower PROP burst effect (reduction of approximately 50%) and higher modulation were observed from the coaxial than from the uniaxial fibers. Thus, the coaxial nanofibers could potentially be a useful strategy for developing a controlled release system for hydrophilic molecules.Comment: 10 pages, 8 figures + Supplementary Data (4 pages, 6 figures

    The imprint of global climate cycles in the Fuentillejo maar-lake record during the last 50 ka cal BP (central Spain)

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    We have analysed the geochemical (element analysis), mineralogical and sedimentary facies to characterize the sedimentary record in Fuentillejo maar-lake in the central Spanish volcanic field of Campo de Calatrava and thus be able to reconstruct the cyclicity of the sedimentary and paleoclimatic processes involved. The upper 20 m of core FUENT-1 show variations in clastic input and water chemistry in the lake throughout the last 50 ka cal BP. Being a closed system, the water level in this maar-lake depends primarily on the balance between precipitation and evaporatio

    Repurposing Disulfiram as an Antimicrobial Agent in Topical Infections

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    Antimicrobial drugs applied topically offer several advantages. However, the widespread use of antibiotics has led to increasing antimicrobial resistance. One interesting approach in the drug discovery process is drug repurposing. Disulfiram, which was originally approved as an anti-alcoholism drug, offers an attractive alternative to treat topical multidrug resistance bacteria in skin human infections. This study aimed to evaluate the biopharmaceutical characteristics of the drug and the effects arising from its topical application in detail. Microdilution susceptibility testing showed antibacterial activity against Gram-positive bacteria Staphylococcus aureus and Streptococcus pyogenes. Dermal absorption revealed no permeation in pig skin. The quantification of the drug retained in pig skin demonstrated concentrations in the stratum corneum and epidermis, enough to treat skin infections. Moreover, in vitro cytotoxicity and micro-array analyses were performed to better understand the mechanism of action and revealed the importance of the drug as a metal ion chelator. Together, our findings suggest that disulfiram has the potential to be repurposed as an effective antibiotic to treat superficial human skin infections

    Designing for shape memory in additive manufacturing of Cu-Al-Ni shape memory alloy processed by laser powder bed fusion

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    Shape memory alloys (SMAs) are functional materials that are being applied in practically all industries, from aerospace to biomedical sectors, and at present the scientific and technologic communities are looking to gain the advantages offered by the new processing technologies of additive manufacturing (AM). However, the use of AM to produce functional materials, like SMAs, constitutes a real challenge due to the particularly well controlled microstructure required to exhibit the functional property of shape memory. In the present work, the design of the complete AM processing route, from powder atomization to laser powder bed fusion for AM and hot isostatic pressing (HIP), is approached for Cu-Al-Ni SMAs. The microstructure of the different processing states is characterized in relationship with the processing parameters. The thermal martensitic transformation, responsible for the functional properties, is analyzed in a comparative way for each one of the different processed samples. The present results demonstrate that a final post-processing thermal treatment to control the microstructure is crucial to obtain the expected functional properties. Finally, it is demonstrated that using the designed processing route of laser powder bed fusion followed by a post-processing HIP and a final specific thermal treatment, a satisfactory shape memory behavior can be obtained in Cu-Al-Ni SMAs, paving the road for further applications

    Nuevos registros y observaciones sobre la historia natural del puercoespĂ­n pardo, Coendou vestitus (Rodentia: Erethizontidae)

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    The brown hairy dwarf porcupine Coendou vestitus is among the most threatened endemic rodent species, with a corroborated presence in few localities in the Eastern Cordillera; departments of BoyacĂĄ and Cundinamarca. We present new records for three localities and natural history observations such as the use of the tail as a support during locomotion and activity hours. As part of local knowledge, the use of their quills as defense against domestic animals and the consumption of chusque (Chusquea sp.) has been identified, as well as the use of the quills by local people in the localities of the records related to their beliefs. Our records extend to 10 the number of localities for the western flank of the Eastern Cordillera, in the Magdalena Valley Montane Forests ecoregion. The records were obtained during the day and at night, so it is necessary to study the activity patterns within Coendou, generalized as nocturnal, and obtain new data on the natural history of this species.El puercoespĂ­n pardo, Coendou vestitus, se encuentra entre los roedores endĂ©micos mĂĄs amenazados de Colombia, con presencia corroborada en pocas localidades de la cordillera Oriental, en los departamentos de BoyacĂĄ y Cundinamarca. Presentamos registros recientes para tres localidades y observaciones de historia natural, como horarios de actividad y el uso de la cola a manera de soporte durante el desplazamiento. Como parte del conocimiento local se ha identificado el uso de sus pĂșas como defensa ante animales domĂ©sticos y el consumo de cañas de chusque (Chusquea sp.), al igual que el uso de las espinas por parte de pobladores de las zonas de registro, relacionado con sus creencias. Nuestros registros, amplĂ­an a diez el nĂșmero de localidades para el flanco occidental de la cordillera Oriental, en la ecorregiĂłn Selvas Montanas del Valle del Magdalena. Los registros fueron obtenidos durante el dĂ­a y la noche, lo que hace necesario estudiar los patrones de actividad de los Coendou, generalizados como nocturnos, y obtener nuevos datos sobre la historia natural de esta especie

    Measurement of the neutron-induced fission cross section of Th 230 at the CERN n_TOF facility

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    The neutron-induced fission cross section of 230 Th has been measured at the neutron time-of-flight facility n_TOF located at CERN. The experiment was performed at the experimental area EAR-1 with a neutron flight path of 185 m, using Micromegas detectors for the detection of the fission fragments. The 230 Th(n, f ) cross section was determined relative to the 235 U(n, f ) one, covering the energy range from the fission threshold up to 400 MeV. The results from the present work are compared with existing cross-section datasets and the observed discrepancies are discussed and analyzed. Finally, using the code EMPIRE 3.2.3 a theoretical study, based on the statistical model, was performed leading to a satisfactory reproduction of the experimental results with the proper tuning of the respective parameters, while for incident neutron energy beyond 200 MeV the fission of 230 Th was described by Monte Carlo simulations.This project received funding from the Euratom “Support safe operation of nuclear systems” program 2014–2018 under Grant Agreement No. 847552 (SANDA) and by the funding agencies of the participating institutes. This research is imple- mented through the IKY scholarships program and cofinanced by the European Union (European Social Fund ’ESF) and Greek national funds through the action entitled “Reinforce- ment of Postdoctoral Researchers - 2nd call (MIS 5033021)”, in the framework of the Operational Programme “Human Resources Development Program, Education and Lifelong Learning” of the National Strategic Reference Framework.Article signat per 137 autors/es: V. Michalopoulou, A. Stamatopoulos, M. Diakaki, A. Tsinganis, R. Vlastou, M. Kokkoris, N. Patronis, Z. Eleme, D. Macina, L. Tassan-Got, N. Colonna, E. Chiaveri, A. Ventura, P. Schillebeeckx, J. Heyse, G. Sibbens, G. Alaerts, A. Borella, A. Moens, D. Vanleeuw, O. Aberle, V. Alcayne, S. Amaducci, J. Andrzejewski, L. Audouin, V. Babiano-Suarez, M. Bacak, M. Barbagallo, S. Bennett, E. Berthoumieux, J. Billowes, D. Bosnar, A. Brown, M. Busso, M. Caamaño, L. Caballero, F. Calviño, M. Calviani, D. Cano-Ott, A. Casanovas, F. Cerutti, G. CortĂ©s, M. A. CortĂ©s-Giraldo, L. Cosentino, S. Cristallo, L. A. Damone, P. J. Davies, M. Dietz, C. Domingo-Pardo, R. Dressler, Q. Ducasse, E. Dupont, I. DurĂĄn, B. FernĂĄndez-DomĂ­nguez, A. Ferrari, P. Finocchiaro, V. Furman, K. Göbel, R. Garg, A. Gawlik-Ramiega, S. Gilardoni, I. F. Gonçalves, E. GonzĂĄlez-Romero, C. Guerrero, F. Gunsing, H. Harada, S. Heinitz, D. G. Jenkins, A. Junghans, F. KĂ€ppeler, Y. Kadi, A. Kimura, I. KnapovĂĄ, Y. Kopatch, M. Krticka, D. Kurtulgil, I. Ladarescu, C. Lederer-Woods, H. Leeb, J. Lerendegui-Marco, S. J. Lonsdale, A. Manna, T. MartĂ­nez, A. Masi, C. Massimi, P. Mastinu, M. Mastromarco, E. A. Maugeri, A. Mazzone, E. Mendoza, A. Mengoni, P. M. Milazzo, F. Mingrone, J. Moreno-Soto, A. Musumarra, A. Negret, R. Nolte, F. OgĂĄllar, A. Oprea, A. Pavlik, J. Perkowski, C. Petrone, L. Piersanti, E. Pirovano, I. Porras, J. Praena, J. M. Quesada, D. Ramos-Doval, T. Rauscher, R. Reifarth, D. Rochman, Y. Romanets, C. Rubbia, M. SabatĂ©-Gilarte, A. Saxena, D. Schumann, A. Sekhar, A. G. Smith, N. V. Sosnin, P. Sprung, G. Tagliente, J. L. Tain, A. Tarifeño-Saldivia, Th. Thomas, P. Torres-SĂĄnchez, J. Ulrich, S. Urlass, S. Valenta, G. Vannini, V. Variale, P. Vaz, D. Vescovi, V. Vlachoudis, A. Wallner, P. J. Woods, T. Wright, and P. Ćœugec.Postprint (published version

    Patients with obstructive sleep apnea can favor the predisposing factors of periodontitis by the presence of P. melaninogenica and C. albicans, increasing the severity of the periodontal disease

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    Q2Q2Pacientes con PeriodontitisPacientes con Apnea obstructiva del sueñoObjective: The aim of this study was to analyze the cultivable oral microbiota of patients with obstructive sleep apnea (OSA) and its association with the periodontal condition. Methods: The epidemiology profile of patients and their clinical oral characteristics were determined. The microbiota was collected from saliva, subgingival plaque, and gingival sulcus of 93 patients classified into four groups according to the periodontal and clinical diagnosis: Group 1 (n = 25), healthy patients; Group 2 (n = 17), patients with periodontitis and without OSA; Group 3 (n = 19), patients with OSA and without periodontitis; and Group 4 (n = 32), patients with periodontitis and OSA. Microbiological samples were cultured, classified, characterized macroscopically and microscopically, and identified by MALDI-TOF-MS. The distribution of complexes and categories of microorganisms and correlations were established for inter- and intra-group of patients and statistically evaluated using the Spearman r test (p-value <0.5) and a multidimensional grouping analysis. Result: There was no evidence between the severity of OSA and periodontitis (p = 0.2813). However, there is a relationship between the stage of periodontitis and OSA (p = 0.0157), with stage III periodontitis being the one with the highest presence in patients with severe OSA (prevalence of 75%; p = 0.0157), with more cases in men. The greatest distribution of the complexes and categories was found in oral samples of patients with periodontitis and OSA (Group 4 P-OSA); even Candida spp. were more prevalent in these patients. Periodontitis and OSA are associated with comorbidities and oral conditions, and the microorganisms of the orange and red complexes participate in this association. The formation of the dysbiotic biofilm was mainly related to the presence of these complexes in association with Candida spp. Conclusion: Periodontopathogenic bacteria of the orange complex, such as Prevotella melaninogenica, and the yeast Candida albicans, altered the cultivable oral microbiota of patients with periodontitis and OSA in terms of diversity, possibly increasing the severity of periodontal disease. The link between yeasts and periodontopathogenic bacteria could help explain why people with severe OSA have such a high risk of stage III periodontitis. Antimicrobial approaches for treating periodontitis in individuals with OSA could be investigated in vitro using polymicrobial biofilms, according to our findings.https://orcid.org/0000-0003-0006-7822https://orcid.org/0000-0003-2528-9632https://orcid.org/0000-0002-1387-1935https://orcid.org/0000-0003-1011-4450https://orcid.org/0000-0002-4069-4719https://orcid.org/0000-0001-5576-9341https://orcid.org/0000-0002-9884-9242https://orcid.org/0000-0003-1803-9141https://orcid.org/0000-0003-1302-5429Revista Internacional - IndexadaA1N

    Multicenter prospective clinical study to evaluate children short-term neurodevelopmental outcome in congenital heart disease (children NEURO-HEART): study protocol.

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    BACKGROUND: Congenital heart disease (CHD) is the most prevalent congenital malformation affecting 1 in 100 newborns. While advances in early diagnosis and postnatal management have increased survival in CHD children, worrying long-term outcomes, particularly neurodevelopmental disability, have emerged as a key prognostic factor in the counseling of these pregnancies. METHODS: Eligible participants are women presenting at 20 to < 37 weeks of gestation carrying a fetus with CHD. Maternal/neonatal recordings are performed at regular intervals, from the fetal period to 24 months of age, and include: placental and fetal hemodynamics, fetal brain magnetic resonance imaging (MRI), functional echocardiography, cerebral oxymetry, electroencephalography and serum neurological and cardiac biomarkers. Neurodevelopmental assessment is planned at 12 months of age using the ages and stages questionnaire (ASQ) and at 24 months of age with the Bayley-III test. Target recruitment is at least 150 cases classified in three groups according to three main severe CHD groups: transposition of great arteries (TGA), Tetralogy of Fallot (TOF) and Left Ventricular Outflow Tract Obstruction (LVOTO). DISCUSSION: The results of NEURO-HEART study will provide the most comprehensive knowledge until date of children's neurologic prognosis in CHD and will have the potential for developing future clinical decisive tools and improving preventive strategies in CHD
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