1,622 research outputs found
Predicting calyceal access for percutaneous nephrolithotomy with computed tomography multiplanar reconstruction
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.
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
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
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
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
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
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
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
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
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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