1,622 research outputs found

    Predicting calyceal access for percutaneous nephrolithotomy with computed tomography multiplanar reconstruction

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    OBJECTIVES: Objective parameters in computed tomography (CT) scans that could predict calyceal access during percutaneous nephrolithotomy have not been evaluated. These parameters could improve access planning for percutaneous nephrolithotomy. We aimed to determine which parameters extracted from a preoperative multiplanar reconstructed CT could predict renal calyceal access during a percutaneous nephrolithotomy. METHODS: From January 2009 through April 2011, 230 patients underwent 284 percutaneous nephrolithotomies at our institution. Sixteen patients presented with complete staghorn calculi, and 11 patients (13 renal units) were analyzed. Five parameters were extracted from a preoperative reconstructed CT and compared with the surgical results of percutaneous nephrolithotomy. RESULTS: Fifty-eight calyces were studied, with an average of 4.4 calyces per procedure. A rigid nephroscope was used to access a particular calyx, and a univariate analysis showed that the entrance calyx had a smaller length (2.7 vs. 3.98 cm, p = 0.018). The particular calyx to be accessed should have a smaller length (2.22 vs. 3.19 cm, p = 0.012), larger angles (117.6 vs. 67.96,

    Nuclear matrix protein Matrin3 regulates alternative splicing and forms overlapping regulatory networks with PTB.

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    Matrin3 is an RNA- and DNA-binding nuclear matrix protein found to be associated with neural and muscular degenerative diseases. A number of possible functions of Matrin3 have been suggested, but no widespread role in RNA metabolism has yet been clearly demonstrated. We identified Matrin3 by its interaction with the second RRM domain of the splicing regulator PTB. Using a combination of RNAi knockdown, transcriptome profiling and iCLIP, we find that Matrin3 is a regulator of hundreds of alternative splicing events, principally acting as a splicing repressor with only a small proportion of targeted events being co-regulated by PTB. In contrast to other splicing regulators, Matrin3 binds to an extended region within repressed exons and flanking introns with no sharply defined peaks. The identification of this clear molecular function of Matrin3 should help to clarify the molecular pathology of ALS and other diseases caused by mutations of Matrin3.We thank Nejc Haberman (UCL) for assisting in the generation of the splicing maps and preparation of the iCLIP data. This work was supported by Wellcome Trust programme grants to CWJS (077877 and 092900), and by grants to EE and NB BIO2011-23920 and RNAREG (CSD2009-00080) from the Spanish Government and by the Sandra Ibarra Foundation for Cancer (FSI2013). JA was supported by a Boehringer Ingelheim Fonds studentship.This is the final version of the article. It first appeared from EMBO Press/Wiley via http://dx.doi.org/10.15252/embj.20148985

    Development of galactomannan-based films from Cassia grandis for the immobilization of biomolecules: physicochemical characterization

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    Galactomannans are polysaccharides formed by a β(1 4)-D-mannan backbone attached to α(1 6)- D-galactose units. They are commonly extracted from leguminous seeds and used as alternative sources for the production of films. Lactoferrin (Lf), bioactive peptides (BAPs), and phytosterols are biomolecules with functional properties and potential immobilization into films. The use of galactomannan films as immobilization systems is unexplored and emerges as an alternative for the incorporation of biomolecules for several biotechnological applications. This work aims evaluating the effect of different concentrations of LF, BAPs and phytosterols on the properties of galactomannan films obtained from Cassia grandis seeds. Colour parameters (L*, a* and b*) and opacity were determined using a digital colorimeter. Solubility in water was expressed as percentage of the film dry matter solubilized after 24 h immersion in distilled water and water vapour permeability (WVP) was determined gravimetrically based on ASTM E96-92 method. Contact angle (CA) was measured by the sessile drop method and mechanical properties were measured using a texture analyzer following the guidelines of ASTM D882-02. All the studied films had a strong whiteness tendency. The presence of Lf increased (p<0.05) the redness appearance of the films, even considering their evident yellowness tendency. All the studied films presented low opacity values (ranged between 11.53±0.15 and 12.37±0.16), however the films with immobilized phytosterols were more opaque than the other films. Solubility values decreased with the addition of Lf, while the incorporation of BAPs and phytosterols did not lead to statistical differences (p>0.05) between the films. The presence of Lf and phytosterols significantly increased the WVP values, leading to values 3.9 and 1.7-fold higher than the control film, respectively. Lf and BAPs increased (p<0.05) the CA values when compared to the results of the control film. Young′s modulus and tensile strength increased with the addition of biomolecules, improving the stiffness of the films, while the control films were more flexible due to the highest values of elongation at break. Galactomannan-based films from C. grandis showed to be a promising structure for the immobilization of biomolecules foreseeing a great number of possible applications in food and pharmaceutical industries

    Effect of cellulose microcrystals in starch and chitosan-based films properties

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    Cellulose microcrystals (CMC) can be used as reinforcing material in the preparation of composite films. This study aimed to evaluate the effect of CMC in starch and chitosan-based films properties. Starch/CMC and Chitosan/CMC composite films were formulated with 1% (w/v) of biopolymer, 0.25% (w/wbiopolymer) glycerol and 0.1% or 0.2% of CMC. The solutions were prepared at 70◦C during 30 min under stirring and submitted to 45 min of ultrasonication. Afterwards were dried in an air-circulating oven at 30◦C for 24 h. The effect of CMC incorporation was evaluated in respect to the surface morphology on a scanning electron microscope (SEM). Solubility was expressed as percentage of the film dry matter solubilized after 24 h immersion in distilled water, and mechanical properties were measured using a texture analyzer following the guidelines of ASTM D 882-10. X-ray diffraction analyses (XRD) were used to evaluate the crystallinity of the samples. SEM micrographs of films with the incorporation of CMC revealed an irregular structure with high heterogeneity and that the roughness of the surface of the films increased for higher concentrations of CMC. Nevertheless, the surface of starch and chitosan films in the absence of CMC are smooth. Regarding to XRD patterns, it was observed that the addition of CMC leads to the presence of reflection peaks at 2θ=22.5° which are related to the cellulose crystalline structure. The values of solubility in water for films with 0.1% and 0.2% of MCM are statistically lower (p<0.05) than for chitosan and starch control films, thus indicating that the presence of CMC reduces the solubility of the film in water. The incorporation of CMC in films decreased the tensile strength values of starch-based films and the elongation at break (p<0.05). Regarding chitosan-based films the incorporation of CMC showed to be effective in increasing the tensile strength values, however leads to a decrease of elongation at break values. Overall, results showed that the incorporation of CMC in chitosan and starch-based films can be used to change the properties of the films and that according to the biopolymer used distinct behaviors can be obtained

    Prophylactic properties of a Leishmania-specific hypothetical protein in a murine model of visceral leishmaniasis

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    In this work, the effect of vaccination of a newly described Leishmania infantum antigenic protein has been studied in BALB/c mice infected with this parasite species. The LiHyD protein was characterized after a proteomic screening performed with the sera from dogs suffering visceral leishmaniasis (VL). Its recombinant version was expressed, purified and administered to BALB/c mice in combination with saponin. As a result of vaccination and 10 weeks after challenge using an infective dose of L. infantum stationary promastigotes, vaccinated mice showed lower parasite burdens in different organs (liver, spleen, bone marrow and footpads' draining lymph nodes) than mice inoculated with the adjuvant alone or the vaccine diluent. Protected mice showed anti-Leishmania IgG2a antibodies and a predominant IL-12-driven IFN-γ production (mainly produced by CD4 T cells) against parasite proteins, whereas unprotected controls showed anti-Leishmania IgG1 antibodies and parasite-mediated IL-4 and IL-10 responses. Vaccinated mice showed an anti-LiHyD IgG2a humoral response, and their spleen cells were able to secrete LiHyD-specific IFN-γ, IL-12 and GM-CSF cytokines before and after infection. The protection was correlated with the Leishmania-specific production on nitric oxide. Altogether, the results indicate that the new LiHyD protein could be considered in vaccine formulations against VL.Instituto Nacional de Ci^encia e Tecnologia em Nano-biofarmac^eutica (INCT-NanoBiofar), FAPEMIG (CBB-APQ-00819-12 and CBB-APQ-01778-2014) and CNPq (APQ-482976/2012-8, APQ-488237/2013-0 and APQ-467640/2014-9). In addition, this study was partially funded by the Spanish grant from Ministerio de Economía y Competitividad-FEDER (FIS PI14/00366 from the Instituto de Salud Carlos III)Peer Reviewe

    Theory of Functional Connections and Nelder-Mead optimization methods applied in satellite characterization

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    The growing population of man-made objects with the build up of mega-constellations not only increases the potential danger to all space vehicles and in-space infrastructures (including space observatories), but above all poses a serious threat to astronomy and dark skies. Monitoring of this population requires precise satellite characterization, which is is a challenging task that involves analyzing observational data such as position, velocity, and light curves using optimization methods. In this study, we propose and analyze the application of two optimization procedures to determine the parameters associated with the dynamics of a satellite: one based on the Theory of Functional Connections (TFC) and another one based on the Nelder-Mead heuristic optimization algorithm. The TFC performs linear functional interpolation to embed the constraints of the problem into a functional. In this paper, we propose to use this functional to analytically embed the observational data of a satellite into its equations of dynamics. After that, any solution will always satisfy the observational data. The second procedure proposed in this research takes advantage of the Nealder-Mead algorithm, that does not require the gradient of the objective function, as alternative solution. The accuracy, efficiency, and dependency on the initial guess of each method is investigated, analyzed, and compared for several dynamical models. These methods can be used to obtain the physical parameters of a satellite from available observational data and for space debris characterization contributing to follow-up monitoring activities in space and astronomical observatories.Comment: Submitted to Acta Astronautic

    Is the tiger shark (Galeocerdo cuvier) a coastal species? Expanding its distribution range in the Atlantic Ocean using at-sea observer data

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    captura asociada a la pesquería de palangre de superficie dirigida a pez espadaThe occurrence of tiger shark (Galeocerdo cuvier) in the Atlantic Ocean was assessed using at-sea observer data from multiple pelagic longline fisheries (Japan, Portugal, Spain, United States and Uruguay). Geographic positions of 2,764 tiger sharks, recorded between 1993 and 2013 and covering a wide area of the Atlantic were compared with the currently accepted distribution ranges of the species. Most of our records fell outside the accepted distribution ranges in both the Southern and Northern hemispheres. These results strongly suggest that the distribution range of the tiger shark is considerably wider than previously described, particularly over the open oceanEn prensa1,834

    Distributional and reproductive aspects of the bigeye thresher shark (Alopias superciliosus) in the Atlantic ocean

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    Captura asociada a la pesquería de palangre de superficie dirigida a pez espadaThe bigeye thresher shark, Alopias supercilious is sometimes caught as bycatch in pelagic longline fisheries targeting tunas and swordfish in the Atlantic Ocean. As part of an ongoing cooperative program for fisheries and biological data collection, fishery observer data from various fishing nations and projects were compiled and analyzed. Those data sets include information on geographic location of the observations, as well as size, sex and in some cases maturity stage. A total of 4371 bigeye threshers were recorded throughout the Atlantic Ocean between 1992 and 2013, with the sizes ranging from 70 to 305 cm FL (fork length). Considerable variability was observed in the catchat- size, with particular emphasis on the tropical region where the mean sizes tended to be smaller than in the other regions. The expected distribution of juvenile and adult specimens also showed considerable variability, and the sex-ratios varied between regions and size classes. Maturity ogives were fitted to data from 642 specimens, with the median sizes at maturity estimated at 208.6 cm FL (corresponding to 349.1 cm TL) for females and 159.2 cm FL (corresponding to 269.8 cm TL) for males. In addition, a segmented regression model (SRM) was used for males, and two breakpoints (Bk1: 122.5cm FL, Bk2: 173.3cm FL) estimated, identifying transitions between the three different maturity stages for male sharks (immature, maturing and mature). Only a few pregnant females were recorded, always with the presence of two embryos (one per uterus), and were distributed predominantly in the tropical northeast Atlantic closer the African continent, and in the southwest region, with those regions possibly serving as nursery areas for this species. These reproductive parameters, and especially the estimated median sizes at maturity and low fecundity, highlight the vulnerability of this species, reinforcing that the bigeye thresher tends to mature at a larger size than the other species of the Alopiidae family. The biological and distributional patterns presented can help managers adopt more informed and efficient conservation measures for this species.En prensa0,000

    Stoichiometry of a regulatory splicing complex revealed by single-molecule analyses

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    Splicing is regulated by complex interactions of numerous RNA-binding proteins. The molecular mechanisms involved remain elusive, in large part because of ignorance regarding the numbers of proteins in regulatory complexes. Polypyrimidine tract-binding protein (PTB), which regulates tissue-specific splicing, represses exon 3 of α-tropomyosin through distant pyrimidine-rich tracts in the flanking introns. Current models for repression involve either PTB-mediated looping or the propagation of complexes between tracts. To test these models, we used single-molecule approaches to count the number of bound PTB molecules both by counting the number of bleaching steps of GFP molecules linked to PTB within complexes and by analysing their total emissions. Both approaches showed that five or six PTB molecules assemble. Given the domain structures, this suggests that the molecules occupy primarily multiple overlapping potential sites in the polypyrimidine tracts, excluding propagation models. As an alternative to direct looping, we propose that repression involves a multistep process in which PTB binding forms small local loops, creating a platform for recruitment of other proteins that bring these loops into close proximity

    Sensitive and specific serodiagnosis of Leishmania infantum infection in dogs by using peptides selected from hypothetical proteins identified by an immunoproteomic approach

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    In Brazil, the percentage of infected dogs living in areas where canine visceral leishmaniasis (CVL) is endemic ranges from 10 to 62%; however, the prevalence of infection in dogs is probably higher than figures reported from serological studies. In addition, problems with the occurrence of false-positive or false-negative results in the serodiagnosis of CVL have been reported. The present work analyzed the potential of synthetic peptides mapped from hypothetical proteins for improvement of the serodiagnosis of Leishmania infantum infection in dogs. From 26 identified leishmanial proteins, eight were selected, considering that no homologies between these proteins and others from trypanosomatide sequence databases were encountered. The sequences of these proteins were mapped to identify linear B-cell epitopes, and 17 peptides were synthesized and tested in enzyme-linked immunosorbent assays (ELISAs) for the serodiagnosis of L. infantum infection in dogs. Of these, three exhibited sensitivity and specificity values higher than 75% and 90%, respectively, to differentiate L. infantum-infected animals from Trypanosoma cruziinfected animals and healthy animals. Soluble Leishmania antigen (SLA) showed poor sensitivity (4%) and specificity (36%) to differentiate L. infantum-infected dogs from healthy and T. cruzi-infected dogs. Lastly, the three selected peptides were combined in different mixtures and higher sensitivity and specificity values were obtained, even when sera from T. cruzi-infected dogs were used. The study’s findings suggest that these three peptides can constitute a potential tool for more sensitive and specific serodiagnosis of L. infantum infection in dogsThis work was supported by grants from the Pró-Reitoria de Pesquisa from UFMG (Edital 07/2012), Instituto Nacional de Ciência e Tecnologia em Nano-biofarmacêutica (INCT-NANOBIOFAR, Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) (CBB-APQ-02364-08, CBB-APQ-00356-10, CBB-APQ-00496-11, and CBB-APQ-00819-12), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (APQ-472090/2011-9), and the Instituto Nacional de Ciência e Tecnologia em Vacinas (INCT-V). E.A.F.C. and A.P.F. are CNPq grant recipients. M.A.C.-F. is a FAPEMIG/CAPES grant recipient. This study was supported in Spain, in part, by grants from the Ministerio de Ciencia e Innovación (FIS/PI1100095)
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