bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maintenance of the enteric stem cell niche by bacterial lipopolysaccharides? Evidence and perspectives
Authors: Schuster Anne , Klotz Markus , Schwab Tanja , Di Liddo Rosa , Bertalot Thomas , Schrenk Sandra , Martin Monika , Nguyen The Duy , Nguyen Thi Nha Quyen , Gries Manuela , Faßbender Klaus , Conconi Maria Teresa , Parnigotto Pier Paolo , Schäfer Karl‐Herbert 
Published: April 2014

AbstractThe enteric nervous system (ENS) has to respond to continuously changing microenvironmental challenges within the gut and is therefore dependent on a neural stem cell niche to keep the ENS functional throughout life. In this study, we hypothesize that this stem cell niche is also affected during inflammation and therefore investigated lipopolysaccharides (LPS) effects on enteric neural stem/progenitor cells (NSPCs). NSPCs were derived from the ENS and cultured under the influence of different LPS concentrations. LPS effects upon proliferation and differentiation of enteric NSPC cultures were assessed using immunochemistry, flow cytometry, western blot, Multiplex ELISA and real‐time PCR. LPS enhances the proliferation of enteric NSPCs in a dose‐dependent manner. It delays and modifies the differentiation of these cells. The expression of the LPS receptor toll‐like receptor 4 on NSPCs could be demonstrated. Moreover, LPS induces the secretion of several cytokines. Flow cytometry data gives evidence for individual subgroups within the NSPC population. ENS‐derived NSPCs respond to LPS in maintaining at least partially their stem cell character. In the case of inflammatory disease or trauma where the liberation and exposure to LPS will be increased, the expansion of NSPCs could be a first step towards regeneration of the ENS. The reduced and altered differentiation, as well as the induction of cytokine signalling, demonstrates that the stem cell niche may take part in the LPS‐transmitted inflammatory processes in a direct and defined way.
Different clinical courses of children exposed to a single incident of psychological trauma: a 30‐month prospective follow‐up study
Authors: Hong Soon‐Beom , Youssef George J. , Song Sook‐Hyung , Choi Nam‐Hee , Ryu Jeong , McDermott Brett , Cobham Vanessa , Park Subin , Kim Jae‐Won , Shin Min‐Sup , Yoo Hee‐Jeong , Cho Soo‐Churl , Kim Bung‐Nyun 
Published: April 2014

BackgroundWe investigated the distinct longitudinal trajectories of posttraumatic stress symptoms in a sample of 167 children, who witnessed death of two mothers of their schoolmates.MethodsThe cohort was followed‐up at 2 days (T1), 2 months (T2), 6 months (T3), and 30 months (T4) after the traumatic event. The children's posttraumatic stress symptoms (T1–T4), depression (T1, T3 and T4), state anxiety (T1, T3 and T4), and quality of life (T4) were assessed, along with parental stress related to child rearing (T4). Different trajectory patterns of the children's posttraumatic stress symptoms were identified using growth mixture modeling (GMM).ResultsFour different patterns of symptom change were identified, which were consistent with the prototypical model, and were named Recovery (19.9%), Resilience (72.7%), Chronic Dysfunction (1.8%), and Delayed Reactions (5.6%). Significant differences were found in depression and anxiety scores, children's quality of life, and parental rearing stress according to the distinct longitudinal trajectories of posttraumatic stress symptoms.ConclusionsThe present study suggests that individual differences should be taken into account in the clinical course and outcome of children exposed to psychological trauma. The two most common trajectories were the Resilience and the Recovery types, together suggesting that over 90% of children were evidenced with a favorable 30‐month outcome. The latent classes were associated with significant mean differences in depression and anxiety scores, supporting the clinical validity of the distinct trajectories.
Lawsonite geochemistry and stability – implication for trace element and water cycles in subduction zones
Authors: Martin L. A. J. , Hermann J. , Gauthiez‐Putallaz L. , Whitney D. L. , Vitale Brovarone A. , Fornash K. F. , Evans N. J. 
Published: April 2014

AbstractThis contribution reviews the existing data on lawsonite stability and trace element geochemistry, and provides new data for metabasaltic and metasedimentary (quartzite) rocks from New Caledonia, Turkey and California. Lawsonite is a major host of REE, Sr, U, Th and Pb in basaltic compositions. Trace element‐rich lawsonite also occurs in metasedimentary rocks, in which comparatively fewer phases compete for trace elements than in metabasaltic rocks. Trace element patterns in lawsonite are influenced by the coexistence or breakdown of allanite, titanite, apatite and garnet that compete for these elements in high‐P metamorphic rocks. Lawsonite is restricted to cool geotherms and therefore is an indicator mineral for subduction‐zone metamorphism. The lawsonite stability field shows a strong dependence on temperature and composition and it is largest in rocks with a high normative anorthite content and, in basaltic systems, carbon content. Along cold geotherms, lawsonite can transport water and trace elements to great depths, providing a source for these elements in the deep mantle. Along warmer geotherms, lawsonite disappears on a continuous reaction, gradually releasing water over a temperature interval of several tens of degrees. During lawsonite breakdown in complex systems, Th and LREE remain trapped in newly formed accessory allanite. However, owing to extreme LREE content, allanite has lower Pb/Ce and Sr/Nd than lawsonite, resulting in a relative enrichment of Sr and Pb compared with Ce and Nd in the fluids produced during lawsonite breakdown. Existing experimental data on the solidus of altered oceanic crust suggest that the lawsonite‐breakdown reaction is within 50 °C of the solidus at sub‐arc pressures of 3–4 GPa.
Activism for Corporate Responsibility: Conceptualizing Private Regulation Opportunity Structures
Authors: Mena Sébastien , Waeger Daniel 
Published: April 2014

AbstractIn this article, we examine how private regulatory initiatives (PRIs) – which define standards for corporate responsibility (CR) issues and sometimes monitor their application by firms – create opportunities and constraints for activist groups aiming to push firms towards more stringent CR activities. Drawing on social movement theory, we conceptualize how private regulation opportunity structures affect such CR‐based activist groups' targets and tactics at both the firm and field levels. At the field level, we argue that both radical and reformative activist groups direct most of their time and resources towards PRIs with comparatively more stringent standards. At the firm level, while radical activist groups are likely to target firms participating in more stringent PRIs, reformative activist groups target firms participating in less stringent PRIs, or those that do not participate in PRIs at all. When facing unfavourable opportunity structures, CR‐based activist groups tend either to advocate the creation of new PRIs or to shift their activities to pressure other focal points. This article contributes to moving beyond extant literature's emphasis of PRIs as settlements of contentious firm–activist interactions towards also viewing them as starting points for activist groups aiming to push firms towards a more substantive CR engagement.
In-vitro/in-vivo characterization of trans-resveratrol-loaded nanoparticulate drug delivery system for oral administration
Authors: Singh Gurinder , Pai Roopa S 
Published: April 2014

Abstract

Objectives
The current studies entail successful formulation of systematically optimized (OPT) nanoparticulate drug delivery system to increase the oral bioavailability using Eudragit RL 100 of trans-resveratrol (t-RVT), and evaluate their in-vitro/in-vivo performance.

Methods
t-RVT-loaded Eudragit RL 100 nanoparticles (t-RVT NPs) were prepared by nanoprecipitation method. The nanoparticles (NPs) were systematically optimized using 32 central composite design and the OPT formulation located using overlay plot. The pharmacokinetic and in-vivo biodistribution of t-RVT NPs were investigated in rats, and various levels of in-vitro/in-vivo correlation (IVIVC) were established.

Key findings
The OPT formulation (mean particle size: 180 nm) indicated marked improvement in drug release profile vis-à-vis pure drug and marketed formulation (MKT). Augmentation in the values of Ka (5.64-fold) and AUC0–24 (7.25-fold) indicated significant enhancement in the rate and extent of bioavailability by the optimized trans-resveratrol-loaded Eudragit RL 100 nanoparticles (OPT-t-RVT NPs) compared with pure drug. Level A of IVIVC was successfully established. OPT-t-RVT NPs showed 4.11-fold rose in the values of t-RVT concentrations in liver. In-situ single pass intestinal perfusion studies construed remarkable enhancement in the absorptivity and permeability parameters of OPT-t-RVT NPs.

Conclusions
The results, therefore, insight into the role of solubility enhancement and trounce enterohepatic recirculation for improving the oral bioavailability of t-RVT.
S-allylcysteine prevents cisplatin-induced nephrotoxicity and oxidative stress
Authors: Gómez-Sierra Tania , Molina-Jijón Eduardo , Tapia Edilia , Hernández-Pando Rogelio , García-Niño Wylly Ramsés , Maldonado Perla D , Reyes José Luis , Barrera-Oviedo Diana , Torres Ismael , Pedraza-Chaverri José 
Published: April 2014

Abstract

Objectives
Cisplatin (CP) is an antineoplastic agent that induces nephrotoxicity and oxidative stress. S-allylcysteine (SAC) is a garlic-derived antioxidant. This study aims to explore whether SAC protects against CP-induced nephrotoxicity in rats.

Methods
In the first stage, the SAC protective dose was determined by measuring renal damage and the oxidative stress markers malondialdehyde, oxidized proteins and glutathione in rats injected with CP. In the second stage, the effect of a single dose of SAC on the expression of nuclear factor-erythroid 2-related factor-2 (Nrf2), protein kinase C beta 2 (PKCβ2) and nicotinamide adenine dinucleotide phosphate oxidase subunits (p47phox and gp91phox) was studied. In addition, the effect of SAC on oxidative stress markers and on the activity of catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) in isolated proximal and distal tubules were evaluated.

Key findings
SAC (25 mg/kg) prevented the CP-induced renal damage and attenuated CP-induced decrease in Nrf2 levels and increase in PKCβ2, p47phox and gp91phox expression in renal cortex and oxidative stress and decrease in the activity of CAT, GPx and GR in proximal and distal tubules.

Conclusions
These data suggest that SAC provides renoprotection by attenuating CP-induced oxidative stress and decrease in the activity of CAT, GPx and GR.
Association of XRCC1 gene polymorphisms with susceptibility to gastric cancer in Chinese Han population
Authors: Meng Hua , Lu Shuming , Zhang Zhuqing , Chen Meiru , Li Chunyan , Liu Lina , Luan Yong 
Published: April 2014

Abstract

Objectives
Gastric cancer is one of the most frequently causing cancer-related deaths worldwide. The X-ray repair complementing group 1 gene (XRCC1) is an important candidate gene for influencing gastric cancer risk. This study aimed to evaluate the associations between XRCC1 genetic variants and gastric cancer susceptibility in Chinese Han population.

Methods
Four hundred twenty-four gastric cancer patients and 430 cancer-free controls were enrolled. Two genetic variants (c.1254C&gt;T and c.1779C&gt;G) of XRCC1 gene were genotyped by created restriction site-polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism methods, respectively.

Key findings
Results from this study indicated that the allele and genotype frequencies of these two genetic variants were statistically different between gastric cancer patients and cancer-free controls. The association analyses suggested that these two genetic variants were statistically associated with the increased risk of gastric cancer (for c.1254C&gt;T, T versus C: odds ratio (OR) = 1.44, 95% confidence interval (CI) 1.17–1.77; for c.1779C&gt;G, G versus C: OR = 1.51, 95% CI 1.22–1.86). The allele-T of c.1254C&gt;T and allele-G c.1779C&gt;G genetic variants may contribute to the susceptibility to gastric cancer in Chinese Han population.

Conclusion
Our data suggest that these two genetic variants might be used as molecular markers for evaluating the susceptibility to gastric cancer.
Anti-human immunodeficiency virus type 1 agent alpha-hydroxy glycineamide enters the target cells via a mechanism of passive diffusion
Authors: Youssefi Masoud , Vahlne Anders 
Published: April 2014

Abstract

Objectives
Alpha-hydroxy glycineamide (αHGA) is the active antiviral metabolite of tri-peptide glycyl-prolyl-glycine-amide (GPG-NH2). αHGA inhibits the replication of HIV-1 in vitro by interfering with the capsid formation. It has also an effect on viral gp160 envelope protein. Since drug transport is an important aspect of drug function, we investigated the mechanism of [14C] αHGA uptake by a human T cell line.

Methods
H9 cells were incubated with defined amounts of radiolabelled αHGA for definite time durations. After harvesting the cells and removal of radiolabelled material, the radioactivity associated with the cells was assayed. Experiments were also designed to address the effect of metabolic inhibitors, temperature and extra unlabelled compound as potential competitor on the cellular uptake of αHGA.

Key findings
Uptake of αHGA into H9 cells was time- and dose-dependent. The uptake properties showed a low temperature dependency (Q10 &lt; 2). Moreover the uptake was not inhibited by increasing concentrations of cold competitors. There was no effect on cellular uptake of αHGA by known metabolic inhibitors, NaN3 and NaF.

Conclusions
Kinetic analysis of compound uptake, metabolic inhibition studies, saturation studies and the Q10 value of αHGA uptake indicate that the compound enters H9 cells by a mechanism of passive diffusion.
A simple and inexpensive point‐of‐care test for hepatitis B surface antigen detection: serological and molecular evaluation
Authors: Gish R. G. , Gutierrez J. A. , Navarro‐Cazarez N. , Giang K. , Adler D. , Tran B. , Locarnini S. , Hammond R. , Bowden S. 
Published: April 2014

SummaryEarly identification of chronic hepatitis B is important for optimal disease management and prevention of transmission. Cost and lack of access to commercial hepatitis B surface antigen (HBsAg) immunoassays can compromise the effectiveness of HBV screening in resource‐limited settings and among marginalized populations. High‐quality point‐of‐care (POC) testing may improve HBV diagnosis in these situations. Currently available POC HBsAg assays are often limited in sensitivity. We evaluated the NanoSign® HBs POC chromatographic immunoassay for its ability to detect HBsAg of different genotypes and with substitutions in the ‘a’ determinant. Thirty‐seven serum samples from patients with HBV infection, covering HBV genotypes A–G, were assessed for HBsAg titre with the Roche Elecsys HBsAg II quantification assay and with the POC assay. The POC assay reliably detected HBsAg at a concentration of at least 50 IU/mL for all genotypes, and at lower concentrations for some genotypes. Eight samples with substitutions in the HBV ‘a’ determinant were reliably detected after a 1/100 dilution. The POC strips were used to screen serum samples from 297 individuals at risk for HBV in local clinical settings (health fairs and outreach events) in parallel with commercial laboratory HBsAg testing (Quest Diagnostics EIA). POC testing was 73.7% sensitive and 97.8% specific for detection of HBsAg. Although the POC test demonstrated high sensitivity over a range of genotypes, false negatives were frequent in a clinical setting. Nevertheless, the POC assay offers advantages for testing in both developed and resource‐limited countries due to its low cost (0.50$) and immediately available results.
A strongly hydrated microclast in the Rumuruti chondrite NWA 6828: Implications for the distribution of hydrous material in the solar system
Authors: Greshake Ansgar 
Published: April 2014

AbstractHydrous carbonaceous microclasts are by far the most abundant foreign fragments in stony meteorites and mostly resemble CI1‐, CM2‐, or CR2‐like material. Their occurrence is of great importance for understanding the distribution and migration of water‐bearing volatile‐rich matter in the solar system. This paper reports the first finding of a strongly hydrated microclast in a Rumuruti chondrite. The R3‐6 chondrite Northwest Africa 6828 contains a 420 × 325 μm sized angular foreign fragment exhibiting sharp boundaries to the surrounding R‐type matrix. The clast is dominantly composed of magnetite, pyrrhotite, rare Ca‐carbonate, and very rare Mg‐rich olivine set in an abundant fine‐grained phyllosilicate‐rich matrix. Phyllosilicates are serpentine and saponite. One region of the clast is dominated by forsteritic olivine (Fa<2) supported by a network of interstitial Ca‐carbonate. The clast is crosscut by Ca‐carbonate‐filled veins and lacks any chondrules, calcium‐aluminum‐rich inclusions, or their respective pseudomorphs. The hydrous clast contains also a single grain of the very rare phosphide andreyivanovite. Comparison with CI1, CM2, and CR2 chondrites as well as with the ungrouped C2 chondrite Tagish Lake shows no positive match with any of these types of meteorites. The clast may, thus, either represent a fragment of an unsampled lithology of the hydrous carbonaceous chondrite parent asteroids or constitute a sample from an as yet unknown parent body, maybe even a comet. Rumuruti chondrites are a unique group of highly oxidized meteorites that probably accreted at a heliocentric distance >1 AU between the formation regions of ordinary and carbonaceous chondrites. The occurrence of a hydrous microclast in an R chondrite attests to the presence of such material also in this region at least at some point in time and documents the wide distribution of water‐bearing (possibly zodiacal cloud) material in the solar system.
Contrasting genetic diversity patterns in two sister kelp species co‐distributed along the coast of Brittany, France
Authors: Robuchon Marine , Le Gall Line , Mauger Stéphane , Valero Myriam 
Published: April 2014

AbstractWe investigated patterns of genetic structure in two sister kelp species to explore how distribution width along the shore, zonation, latitudinal distribution and historical factors contribute to contrasting patterns of genetic diversity. We implemented a hierarchical sampling scheme to compare patterns of genetic diversity and structure in these two kelp species co‐distributed along the coasts of Brittany (France) using a total of 12 microsatellites, nine for Laminaria hyperborea and 11 for Laminaria digitata, of which eight amplified in both species. The genetic diversity and connectivity of L. hyperborea populations were greater than those of L. digitata populations in accordance with the larger cross‐shore distribution width along the coast and the greater depth occupied by L. hyperborea populations in contrast to L. digitata populations. In addition, marginal populations showed reduced genetic diversity and connectivity, which erased isolation‐by‐distance patterns in both species. As L. digitata encounters its southern range limit in southern Brittany (SBr) while L. hyperborea extends down to mid‐Portugal, it was possible to distinguish the effect of habitat continuity from range edge effects. We found that L. digitata did not harbour high regional diversity at its southern edge, as expected in a typical rear edge, suggesting that refuges from the last glacial maximum for L. digitata were probably not located in SBr, but most likely further north. For both species, the highest levels of genetic diversity were found in the Iroise Sea and Morlaix Bay, the two regions in which they are being currently harvested. Preserving genetic diversity of these two foundation species in these areas should, thus, be a priority for the management of this resource in Brittany.
Evolutionary basis of mitonuclear discordance between sister species of mole salamanders (Ambystoma sp.)
Authors: Denton Robert D. , Kenyon Laura J. , Greenwald Katherine R. , Gibbs H.Lisle 
Published: April 2014

AbstractDistinct genetic markers should show similar patterns of differentiation between species reflecting their common evolutionary histories, yet there are increasing examples of differences in the biogeographic distribution of species‐specific nuclear (nuDNA) and mitochondrial DNA (mtDNA) variants within and between species. Identifying the evolutionary processes that underlie these anomalous patterns of genetic differentiation is an important goal. Here, we analyse the putative mitonuclear discordance observed between sister species of mole salamanders (Ambystoma barbouri and A. texanum) in which A. barbouri‐specific mtDNA is found in animals located within the range of A. texanum. We test three hypotheses for this discordance (undetected range expansion, mtDNA introgression, and hybridization) using nuDNA and mtDNA data analysed with methods that varied in the parameters estimated and the timescales measured. Results from a Bayesian clustering technique (structure), bidirectional estimates of gene flow (migrate‐n and IMa2) and phylogeny‐based methods (*beast, bucky) all support the conclusion that the discordance is due to geographically restricted mtDNA introgression from A. barbouri into A. texanum. Limited data on species‐specific tooth morphology match this conclusion. Significant differences in environmental conditions exist between sites where A. texanum with and without A. barbouri‐like mtDNA occur, suggesting a possible role for selection in the process of introgression. Overall, our study provides a general example of the value of using complimentary analyses to make inferences of the directionality, timescale, and source of mtDNA introgression in animals.
Impact of the functional status of saeRS on in vivo phenotypes of Staphylococcus aureus sarA mutants
Authors: Beenken Karen E. , Mrak Lara N. , Zielinska Agnieszka K. , Atwood Danielle N. , Loughran Allister J. , Griffin Linda M. , Matthews K. Alice , Anthony Allison M. , Spencer Horace J. , Skinner Robert A. , Post Ginell R. , Lee Chia Y. , Smeltzer Mark S. 
Published: April 2014

SummaryWe investigated the in vivo relevance of the impact of sarA and saeRS on protease production using derivatives of the USA300 strain LAC. The results confirmed that mutation of saeRS or sarA reduces virulence in a bacteremia model to a comparable degree. However, while eliminating protease production restored virulence in the sarA mutant, it had little impact in the saeRS mutant. Additionally, constitutive activation of saeRS (saeRSC) enhanced the virulence of LAC and largely restored virulence in the isogenic sarA mutant. Based on these results, together with our analysis of the representative virulence factors alpha toxin, protein A (Spa), and extracellular nucleases, we propose a model in which the attenuation of saeRS mutants is defined primarily by decreased production of such factors, while constitutive activation of saeRS increases virulence, and reverses the attenuation of sarA mutants, because it results in both increased production and decreased protease‐mediated degradation of these same factors. This regulatory balance was also apparent in a murine model of catheter‐associated infection, with the results suggesting that the impact of saeRS on nuclease production plays an important role during the early stages of these infections that is partially offset by increased protease production in sarA mutants.