217 research outputs found
Rapid Identification of Viable H. pylori Cells in Feces by DVCFISH
[EN] Helicobacter pylori isolation in fecal samples is a less invasive and more comfortable practice than those that require patient endoscopy, particularly in children. However, culture of this pathogen from stools is usually unsuccessful. Other techniques such as PCR or H. pylori Stool Antigen (HpSA) are used to detect the presence of H. pylori in feces; nevertheless, a positive result by using these techniques does not involve viability of the pathogen. Direct Viable Count combined with Fluorescent in situ Hybridization (DVC-FISH) technique has been successfully applied to detect viable H. pylori cells in highly contaminated environmental samples. To assess the suitability of DVC-FISH technique to identify viable H. pylori cells in stools, experimentally inoculated feces and fecal samples from infected patients were analyzed. qPCR and culture techniques were also used. Viable H. pylori cells were detected by DVC-FISH in all inoculated samples with a specific DNA/LNA probe. H. pylori colonies were also identified on agar. DVC-FISH gave positive results in all the patients' fecal samples, while qPCR only detected H. pylori in two patients.
DVC-FISH technique with LNA/DNA probes has the potential to be used as a specific and effective non-invasive method for the detection of viable H. pylori in stools samples. Moreover, our results evidence the presence of viable H. pylori cells in fecal samples from infected patients, supporting the evidence that H. pylori is transmitted via the fecal route.The work has been funded by AGL2014-53875-R grant (Ministerio de Economía y Competitividad, Spain).Moreno Trigos, MY.; Pérez-Santonja, R.; Ramirez, M.; Calvet, X.; Santiago Cuellar, P.; Ferrús Pérez, MA. (2015). Rapid Identification of Viable H. pylori Cells in Feces by DVCFISH. JSM Gastroenterology and Hepatology. 3(3). http://hdl.handle.net/10251/97911S3
Increased exosome secretion in neurons aging in vitro by NPC1-mediated endosomal cholesterol buildup
As neurons age, they show a decrease in their ability to degrade proteins and membranes. Because undegraded material is a source of toxic products, defects in degradation are associated with reduced cell function and survival. However, there are very few dead neurons in the aging brain, suggesting the action of compensatory mechanisms. We show in this work that ageing neurons in culture show large multivesicular bodies (MVBs) filled with intralumenal vesicles (ILVs) and secrete more small extracellular vesicles than younger neurons. We also show that the high number of ILVs is the consequence of the accumulation of cholesterol in MVBs, which in turn is due to decreased levels of the cholesterol extruding protein NPC1. NPC1 down-regulation is the consequence of a combination of upregulation of the NPC1 repressor microRNA 33, and increased degradation, due to AktmTOR targeting of NPC1 to the phagosome. Although releasing more exosomes can be beneficial to old neurons, other cells, neighbouring and distant, can be negatively affected by the waste material they contain.Fil: Guix, Francesc X.. Universidad Autónoma de Madrid; España. Consejo Superior de Investigaciones Científicas; EspañaFil: Marrero Capitán, Ana. Consejo Superior de Investigaciones Científicas; España. Universidad Autónoma de Madrid; EspañaFil: Casadomé Perales, Álvaro. Consejo Superior de Investigaciones Científicas; España. Universidad Autónoma de Madrid; EspañaFil: Palomares Pérez, Irene. Consejo Superior de Investigaciones Científicas; España. Universidad Autónoma de Madrid; EspañaFil: Lopez del Castillo, Irene. Consejo Superior de Investigaciones Científicas; España. Universidad Autónoma de Madrid; EspañaFil: Miguel, Verónica. Consejo Superior de Investigaciones Científicas; España. Universidad Autónoma de Madrid; EspañaFil: Goedeke, Leigh. University of Yale; Estados UnidosFil: Martín, Mauricio Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Lamas, Santiago. Consejo Superior de Investigaciones Científicas; España. Universidad Autónoma de Madrid; EspañaFil: Peinado, Héctor. Centro Nacional de Investigaciones Oncológicas; EspañaFil: Fernández Hernando, Carlos. University of Yale; Estados UnidosFil: Dotti, Carlos. Universidad Autónoma de Madrid; España. Consejo Superior de Investigaciones Científicas; Españ
Sheep reproductive management
Objetive: Describe some reproductive management programs that have made it possible to increase the productive efficiency of sheep.
Desing/methodology/approach: Description of the main hormones and their application in sheep reproductive management protocols. The topics are addressed from academic references and use in sheep reproductive protocols in the Reproduction Laboratory for Sheep and Goat of the Colegio de Postgraduados, Mexico.
Results: The use of hormones, socio-sexual strategies, reproductive protocols and techniques are tools that improve the reproductive efficiency of sheep during the reproductive and seasonal anestrus season.
Study limitations/implications: The basic techniques of reproductive management and protocols in sheep are mostly available, however they still have a wide margin for improvement, which requires multiple efforts that involve all participating sectors, such as the primary sector, institutions public and private.
Findings/conclusions: Reproductive management is a pillar of great importance in animal production, which is why it is essential to implement it to improve the reproductive and productive efficiency of the herd.Objective: To describe some reproductive management programs that allow increasing the productive efficiency of ewes.
Design/methodology/approach: Description of the main hormones and their application in sheep reproductive management protocols. The subjects are reviewed based on academic references as well as on their use in sheep reproductive protocols at the Sheep and Goat Reproduction Laboratory of the Colegio de Postgraduados, Mexico.
Results: Hormones, socio-sexual strategies, reproductive protocols and techniques are tools that improve the reproductive efficiency of ewes during the reproductive season and seasonal anestrus.
Study limitations/implications: The basic techniques of reproductive management and protocols in sheep are mostly available, however, they still have room for improvement, therefore, multiple efforts involving all participants, such as the primary sector, public and private institutions, are required.
Findings/conclusions: Reproductive management is an important pillar for animal production; thus its implementation is fundamental to improve the reproductive and productive efficiency of a her
Fagerstrom test for nicotine dependence vs heavy smoking index in a general population survey
<p>Abstract</p> <p>Background</p> <p>The Fagerström Test for Nicotine Dependence (FTND) is used for assessing nicotine dependence. A shorter test derived from the FTND used for the general population is the Heavy Smoking Index (HSI) (six questions vs. two). The objective of this study is to compare the validity of the HSI versus the FTND.</p> <p>Methods</p> <p>A survey of tobacco use in the general population was carried out in the northern Spanish region of Galicia using both the FTND and the HSI to study a representative sample of 1655 daily smokers. The HSI was compared with the FTND, considered the gold standard. Measures of sensitivity, specificity and predictive values were calculated. Concordance between the tests was also established (Cohen's kappa).</p> <p>Results</p> <p>Cohen's kappa showed good agreement between measures (Kappa = 0.7); specificity values were also high (Sp = 96.2%). Sensitivity analysis in females (Se = 62.3%) did not show good agreement.</p> <p>Conclusions</p> <p>The HSI can be used as a reasonably good screening test in order to identify daily smokers with high nicotine dependence. Nevertheless, for populations or subpopulations having low nicotine dependence, such as women, the FTND is more reliable.</p
Parkin loss of function contributes to RTP801 elevation and neurodegeneration in Parkinson"s disease
Mutations in the PARK2 gene are associated with an autosomal recessive form of juvenile parkinsonism (AR-JP). These mutations affect parkin solubility and impair its E3 ligase activity, leading to a toxic accumulation of proteins within susceptible neurons that results in a slow but progressive neuronal degeneration and cell death. Here, we report that RTP801/REDD1, a pro-apoptotic negative regulator of survival kinases mTOR and Akt, is one of such parkin substrates. We observed that parkin knockdown elevated RTP801 in sympathetic neurons and neuronal PC12 cells, whereas ectopic parkin enhanced RTP801 poly-ubiquitination and proteasomal degradation. In parkin knockout mouse brains and in human fibroblasts from AR-JP patients with parkin mutations, RTP801 levels were elevated. Moreover, in human postmortem PD brains with mutated parkin, nigral neurons were highly positive for RTP801. Further consistent with the idea that RTP801 is a substrate for parkin, the two endogenous proteins interacted in reciprocal co-immunoprecipitates of cell lysates. A potential physiological role for parkin-mediated RTP801 degradation is indicated by observations that parkin protects neuronal cells from death caused by RTP801 overexpression by mediating its degradation, whereas parkin knockdown exacerbates such death. Similarly, parkin knockdown enhanced RTP801 induction in neuronal cells exposed to the Parkinson's disease mimetic 6-hydroxydopamine and increased sensitivity to this toxin. This response to parkin loss of function appeared to be mediated by RTP801 as it was abolished by RTP801 knockdown. Taken together these results indicate that RTP801 is a novel parkin substrate that may contribute to neurodegeneration caused by loss of parkin expression or activity
Polymorphism in the Plasmodium vivax msp 3: gene in field samples from Tierralta, Colombia
StarHorse results for spectroscopic surveys + Gaia DR3: Chrono-chemical populations in the solar vicinity, the genuine thick disk, and young-alpha rich stars
The Gaia mission has provided an invaluable wealth of astrometric data for
more than a billion stars in our Galaxy. The synergy between Gaia astrometry,
photometry, and spectroscopic surveys give us comprehensive information about
the Milky Way. Using the Bayesian isochrone-fitting code StarHorse, we derive
distances and extinctions for more than 10 million unique stars observed by
both Gaia Data Release 3 as well as public spectroscopic surveys: GALAH DR3,
LAMOST DR7 LRS, LAMOST DR7 MRS, APOGEE DR17, RAVE DR6, SDSS DR12 (optical
spectra from BOSS and SEGUE), Gaia-ESO DR5 survey, and Gaia RVS part of Gaia
DR3 release. We use StarHorse for the first time to derive stellar age for
main-sequence turnoff and subgiant branch stars (MSTO-SGB), around 2.5 million
stars with age uncertainties typically around 30%, 15% for only SGB stars,
depending on the resolution of the survey. With the derived ages in hand, we
investigate the chemical-age relations. In particular, the and
neutron-capture element ratios versus age in the solar neighbourhood show
trends similar to previous works, validating our ages. We use the chemical
abundances from local subgiant samples of GALAH DR3, APOGEE DR17 and LAMOST MRS
DR7 to map groups with similar chemical compositions and StarHorse ages with
the dimensionality reduction technique t-SNE and the clustering algorithm
HDBSCAN. We identify three distinct groups in all three samples. Their
kinematic properties confirm them to be the genuine chemical thick disk, the
thin disk and a considerable number of young alpha-rich stars. We confirm that
the genuine thick disk's kinematics and age properties are radically different
from those of the thin disk and compatible with high-redshift (z2)
star-forming disks with high dispersion velocities.Comment: 27 pages, 19 figures. Accepted for publication in Astronomy &
Astrophysics. Catalogues can be downloaded at https://data.aip.de
Disruption of the Lipid-Transporting LdMT-LdRos3 Complex in Leishmania donovani Affects Membrane Lipid Asymmetry but Not Host Cell Invasion
Maintenance and regulation of the asymmetric lipid distribution across eukaryotic plasma membranes is governed by the concerted action of specific membrane proteins controlling lipid movement across the bilayer. Here, we show that the miltefosine transporter (LdMT), a member of the P4-ATPase subfamily in Leishmania donovani, and the Cdc50-like protein LdRos3 form a stable complex that plays an essential role in maintaining phospholipid asymmetry in the parasite plasma membrane. Loss of either LdMT or LdRos3 abolishes ATP-dependent transport of NBD-labelled phosphatidylethanolamine (PE) and phosphatidylcholine from the outer to the inner plasma membrane leaflet and results in an increased cell surface exposure of endogenous PE. We also find that promastigotes of L. donovani lack any detectable amount of phosphatidylserine (PS) but retain their infectivity in THP-1-derived macrophages. Likewise, infectivity was unchanged for parasites without LdMT-LdRos3 complexes. We conclude that exposure of PS and PE to the exoplasmic leaflet is not crucial for the infectivity of L. donovani promastigotes
A fast and accurate method to detect allelic genomic imbalances underlying mosaic rearrangements using SNP array data
<p>Abstract</p> <p>Background</p> <p>Mosaicism for copy number and copy neutral chromosomal rearrangements has been recently identified as a relatively common source of genetic variation in the normal population. However its prevalence is poorly defined since it has been only studied systematically in one large-scale study and by using non optimal <it>ad-hoc </it>SNP array data analysis tools, uncovering rather large alterations (> 1 Mb) and affecting a high proportion of cells. Here we propose a novel methodology, Mosaic Alteration Detection-MAD, by providing a software tool that is effective for capturing previously described alterations as wells as new variants that are smaller in size and/or affecting a low percentage of cells.</p> <p>Results</p> <p>The developed method identified all previously known mosaic abnormalities reported in SNP array data obtained from controls, bladder cancer and HapMap individuals. In addition MAD tool was able to detect new mosaic variants not reported before that were smaller in size and with lower percentage of cells affected. The performance of the tool was analysed by studying simulated data for different scenarios. Our method showed high sensitivity and specificity for all assessed scenarios.</p> <p>Conclusions</p> <p>The tool presented here has the ability to identify mosaic abnormalities with high sensitivity and specificity. Our results confirm the lack of sensitivity of former methods by identifying new mosaic variants not reported in previously utilised datasets. Our work suggests that the prevalence of mosaic alterations could be higher than initially thought. The use of appropriate SNP array data analysis methods would help in defining the human genome mosaic map.</p
A novel class of multitarget anti-Alzheimer benzohomoadamantane‒chlorotacrine hybrids modulating cholinesterases and glutamate NMDA receptors
The development of multitarget compounds against multifactorial diseases, such as Alzheimer's disease, is an area of very intensive research, due to the expected superior therapeutic efficacy that should arise from the simultaneous modulation of several key targets of the complex pathological network. Here we describe the synthesis and multitarget biological profiling of a new class of compounds designed by molecular hybridization of an NMDA receptor antagonist fluorobenzohomoadamantanamine with the potent acetylcholinesterase (AChE) inhibitor 6-chlorotacrine, using two different linker lengths and linkage positions, to preserve or not the memantine-like polycyclic unsubstituted primary amine. The best hybrids exhibit greater potencies than parent compounds against AChE (IC50 0.33 nM in the best case, 44-fold increased potency over 6-chlorotacrine), butyrylcholinesterase (IC50 21 nM in the best case, 24-fold increased potency over 6-chlorotacrine), and NMDA receptors (IC50 0.89 µM in the best case, 2-fold increased potency over the parent benzohomoadamantanamine and memantine), which suggests an additive effect of both pharmacophoric moieties in the interaction with the primary targets. Moreover, most of these compounds have been predicted to be brain permeable. This set of biological properties makes them promising leads for further anti-Alzheimer drug development
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