bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ethylglucuronide as a potential marker for alcohol‐induced elevation of urinary testosterone/epitestosterone ratios
Authors: Große Joachim , Anielski Patricia , Sachs Hans , Thieme Detlef 
Published: January 2010

AbstractThe potential influence of alcohol consumption on endogenous steroids has already been described in the literature. In those studies the ethanol level after ingestion was monitored using its concentration in blood, urine or saliva. Corresponding methods are not commonly used in anti‐doping laboratories. Ethylglucuronide (EtG), which can be easily detected by liquid chromatography coupled to tandem mass spectrometry (LC‐MS/MS), appears to be a more suitable parameter for this purpose. It is slowly excreted into the urine and indicates alcohol intake for a much longer period than blood or urinary alcohol and it is therefore routinely used for legal purposes as an alcohol consumption marker. In pharmacokinetic studies that aimed to establish calculation models after ethanol intake, the formation of EtG was observed to coincide with elevated urinary testosterone/epitestosterone (T/E) ratios. Similarly, large amounts of EtG were correlated with abnormal steroid profiles found in routine doping samples. In this pilot study, several cases with significantly elevated T/E ratios were associated with urinary EtG concentrations higher than 50 µg/mL. These findings confirmed recent intake of ethanol in considerable amounts and suggest a connection to changes in specific steroid profile parameters. Owing to the ease with which procedures to determine EtG can be carried out, and the potential for such procedures to be introduced into screening schemes, the inclusion of this marker in the final evaluation of suspicious outliers in T/E ratio longitudinal studies would seem to be very useful. Copyright © 2010 John Wiley & Sons, Ltd.
Reiterative use of the notch signal during zebrafish intrahepatic biliary development
Authors: Lorent Kristin , Moore John C. , Siekmann Arndt F. , Lawson Nathan , Pack Michael 
Published: January 2010

AbstractThe Notch signaling pathway regulates specification of zebrafish liver progenitor cells towards a biliary cell fate. Here, using staged administration of a pharmacological inhibitor of Notch receptor processing, we show that activation of the Notch pathway is also important for growth and expansion of the intrahepatic biliary network in zebrafish larvae. Biliary expansion is accompanied by extensive cell proliferation and active remodeling of the nascent ductal network, as revealed by time lapse imaging of living zebrafish larvae that express a Notch responsive fluorescent reporter transgene. Together, these data support a model in which the Notch signal functions reiteratively during biliary development; first to specific biliary cells and then to direct remodeling of the nascent biliary network. As the Notch pathway plays a comparable role during mammalian biliary development, including humans, these studies also indicate broad conservation of the molecular mechanisms directing biliary development in vertebrates. Developmental Dynamics 239:855–864, 2010. © 2010 Wiley‐Liss, Inc.
Cell fate specification in the C. elegans embryo
Authors: Maduro Morris F. 
Published: January 2010

AbstractCell specification requires that particular subsets of cells adopt unique expression patterns that ultimately define the fates of their descendants. In C. elegans, cell fate specification involves the combinatorial action of multiple signals that produce activation of a small number of “blastomere specification” factors. These initiate expression of gene regulatory networks that drive development forward, leading to activation of “tissue specification” factors. In this review, the C. elegans embryo is considered as a model system for studies of cell specification. The techniques used to study cell fate in this species, and the themes that have emerged, are described. Developmental Dynamics 239:1315–1329, 2010. © 2010 Wiley‐Liss, Inc.
2′‐Linking of Lipids and Other Functions to Uridine through 1,2,3‐Triazoles and Membrane Anchoring of the Amphiphilic Products
Authors: Kaczmarek Oliver , Scheidt Holger A. , Bunge Andreas , Föse David , Karsten Sebastian , Arbuzova Anna , Huster Daniel , Liebscher Jürgen 
Published: January 2010

AbstractA straightforward synthesis of 2′‐functionalized uridines was developed based on a Cu‐catalyzed cycloaddition of 2′‐azido‐2′‐deoxyuridine and functionalized alkynes. The functions comprise biochemically important groups such as lipids, a fluorescent marker (Cy5 analogue), pentaacetylglucose, lysine and biotin, and are linked to the 2′‐position of uridine by a 1,2,3‐triazole ring. A number of NMR spectroscopic investigations revealed that the lipidated 2′‐triazolyl‐2′‐deoxyuridines anchor themselves in the phospholipid membranes without affecting the molecular order in the double layers; the polar moieties – uracil, ribose and triazole – are located in the lipid/water interface of the membrane.
Fluorous‐Assisted One‐Pot Oligosaccharide Synthesis
Authors: Yang Bo , Jing Yuqing , Huang Xuefei 
Published: January 2010

AbstractA new method for oligosaccharide assembly that combines the advantages of one‐pot synthesis and fluorous separation is described. After one‐pot glycosylations are completed, a fluorous tag is introduced into the reaction mixture to selectively “catch” the desired oligosaccharide, which is rapidly separated from non‐fluorous impurities by fluorous solid‐phase extraction (F‐SPE). Subsequent “release” of the fluorous tag and F‐SPE achieved the purification of the desired oligosaccharide without the use of time‐ and solvent‐consuming silica gel chromatography. Linear and branched oligosaccharides have been synthesized with this approach in just a few hours (for the overall oligosaccharide assembly and purification process).
Rapid and sensitive DNA target detection using enzyme amplified electrochemical detection based on microchip
Authors: Cao Wei , Su Mingming , Zhang Shusheng 
Published: January 2010

AbstractA rapid and sensitive DNA targets detection using enzyme amplified electrochemical detection (ED) based on microchip was described. We employed a biotin‐modified DNA, which reacted with avidin‐conjugated horseradish peroxidase (avidin–HRP) to obtain the HRP‐labeled DNA probe and hybridized with its complementary target. After hybridization, the mixture containing dsDNA‐HRP, excess ssDNA‐HRP, and remaining avidin–HRP was separated by MCE. The separations were performed at a separation voltage of +1.6 kV and were completed in less than 100 s. The HRP was used as catalytic labels to catalyze H2O2/o‐aminophenol reaction. Target DNA could be detected by the HRP‐catalyzed reduction with ED. With this protocol, the limits of quantification for the hybridization assay of 21‐ and 39‐mer DNA fragments were of 8×10−12 M and 1.2×10−11 M, respectively. The proposed method has been applied satisfactorily in the analysis of Escherichia coli genomic DNA. We selected the detection of PCR amplifications from the gene of E. coli to test the real applicability of our method. By using an asymmetric PCR protocol, we obtained ssDNA targets of 148 bp that could be directly hybridized by the single‐stranded probe and detected with ED.
Stabilizing labile DNA–protein complexes in polyacrylamide gels
Authors: Sidorova Nina Y. , Hung Stevephen , Rau Donald C. 
Published: January 2010

AbstractThe electrophoretic mobility‐shift assay (EMSA) is one of the most popular tools in molecular biology for measuring DNA–protein interactions. EMSA, as standardly practiced today, works well for complexes with association binding constants Ka>109 M−1 under normal conditions of salt and pH. Many DNA–protein complexes are not stable enough so that they dissociate while moving through the gel matrix giving smeared bands that are difficult to quantitate reliably. In this work we demonstrate that the addition of the osmolyte triethylene glycol to polyacrylamide gels dramatically stabilizes labile restriction endonuclease EcoRI complexes with nonspecific DNA sequences enabling quantitation of binding using EMSA. The significant improvement of the technique resulting from the addition of osmolytes to the gel matrix greatly extends the range of binding constants of protein–DNA complexes that can be investigated using this widely used assay. Extension of this approach to other techniques used for separating bound and free components such as gel chromatography and CE is straightforward.
Efficient sampling and data reduction techniques for probabilistic seismic lifeline risk assessment
Authors: Jayaram Nirmal , Baker Jack W. 
Published: January 2010

AbstractProbabilistic seismic risk assessment for spatially distributed lifelines is less straightforward than for individual structures. While procedures such as the ‘PEER framework’ have been developed for risk assessment of individual structures, these are not easily applicable to distributed lifeline systems, due to difficulties in describing ground‐motion intensity (e.g. spectral acceleration) over a region (in contrast to ground‐motion intensity at a single site, which is easily quantified using Probabilistic Seismic Hazard Analysis), and since the link between the ground‐motion intensities and lifeline performance is usually not available in closed form. As a result, Monte Carlo simulation (MCS) and its variants are well suited for characterizing ground motions and computing resulting losses to lifelines. This paper proposes a simulation‐based framework for developing a small but stochastically representative catalog of earthquake ground‐motion intensity maps that can be used for lifeline risk assessment. In this framework, Importance Sampling is used to preferentially sample ‘important’ ground‐motion intensity maps, and K‐Means Clustering is used to identify and combine redundant maps in order to obtain a small catalog. The effects of sampling and clustering are accounted for through a weighting on each remaining map, so that the resulting catalog is still a probabilistically correct representation. The feasibility of the proposed simulation framework is illustrated by using it to assess the seismic risk of a simplified model of the San Francisco Bay Area transportation network. A catalog of just 150 intensity maps is generated to represent hazard at 1038 sites from 10 regional fault segments causing earthquakes with magnitudes between five and eight. The risk estimates obtained using these maps are consistent with those obtained using conventional MCS utilizing many orders of magnitudes more ground‐motion intensity maps. Therefore, the proposed technique can be used to drastically reduce the computational expense of a simulation‐based risk assessment, without compromising the accuracy of the risk estimates. This will facilitate computationally intensive risk analysis of systems such as transportation networks. Finally, the study shows that the uncertainties in the ground‐motion intensities and the spatial correlations between ground‐motion intensities at various sites must be modeled in order to obtain unbiased estimates of lifeline risk. Copyright © 2010 John Wiley & Sons, Ltd.
Delivery horizon and grain market volatility
Authors: Karali Berna , Dorfman Jeffrey H. , Thurman Walter N. 
Published: January 2010

AbstractWe study the difference in the volatility dynamics of CBOT corn, soybeans, and oats futures prices across different delivery horizons via a smoothed Bayesian estimator. We find that futures price volatilities in these markets are affected by inventories, time to delivery, and the crop progress period and that there are important differences in the effects across delivery horizons. We also find that price volatility is higher before the harvest starts in most cases compared to the volatility during the planting period. These results have implications for hedging, options pricing, and the setting of margin requirements. © 2010 Wiley Periodicals, Inc. Jrl Fut Mark 30:846–873, 2010
Rapidly induced gene networks following induction of long‐term potentiation at perforant path synapses in vivo
Authors: Ryan Margaret M. , Mason‐Parker Sara E. , Tate Warren P. , Abraham Wickliffe C. , Williams Joanna M. 
Published: January 2010

AbstractThe canonical view of the maintenance of long‐term potentiation (LTP), a widely accepted experimental model for memory processes, is that new gene transcription contributes to its consolidation; however, the gene networks involved are unknown. To address this issue, we have used high‐density Rat 230.2 Affymetrix arrays to establish a set of genes induced 20‐min post‐LTP, and using Ingenuity Pathway network analysis tools we have investigated how these early responding genes are interrelated. This analysis identified LTP‐induced regulatory networks in which the transcription factors (TFs) nuclear factor‐KB and serum response factor, which, to date, have not been widely recognized as coordinating the early gene response, play a key role alongside the more well‐known TFs cyclic AMP response element‐binding protein, and early growth response 1. Analysis of gene‐regulatory promoter sites and chromosomal locations of the genes within the dataset reinforced the importance of these molecules in the early gene response and predicted that the coordinated action might arise from gene clustering on particular chromosomes. We have also identified a transcription‐based response that affects mitogen‐activated protein kinase signaling pathways and protein synthesis during the stabilization of the LTP response. Furthermore, evidence from biological function, networks, and regulatory analyses showed convergence on genes related to development, proliferation, and neurogenesis, suggesting that these functions are regulated early following LTP induction. This raises the interesting possibility that LTP‐related gene expression plays a role in both synaptic reorganization and neurogenesis. © 2010 Wiley‐Liss, Inc.
McGrath v Riddell: A flexible approach to the insolvency distribution rules?
Authors: Mamutse Blanca 
Published: January 2010

AbstractThe rules relating to the division of the insolvent estate assume considerable importance in the field of international insolvencies, where different legal systems interact. International instruments including the European insolvency regulation and the UNCITRAL Model Law on Cross‐Border Insolvency have provided a framework which governs the relationship between local and foreign distribution schemes. For English lawyers, questions remain however regarding the future role of the courts' statutory power to cooperate with the courts of ‘relevant’ countries or territories, and of the common law principle of universalism. An important issue connected to the determination of such questions is the established judicial approach to the pari passu rule, in the application of domestic law. This paper examines the manifestation of this tension in the litigation arising from the collapse of the HIH Casualty & General Insurance group of companies. It notes the scope which remains for continued resort to the statutory power of cooperation, and the potential for the Cross‐Border Insolvency Regulations 2006 to encourage a more flexible approach to resolving differences between distribution schemes. Copyright © 2010 John Wiley & Sons, Ltd.
A novel resorption assay for osteoclast functionality based on an osteoblast‐derived native extracellular matrix
Authors: Lutter Anne‐Helen , Hempel Ute , Wolf‐Brandstetter Cornelia , Garbe Annette I. , Goettsch Claudia , Hofbauer Lorenz C. , Jessberger Rolf , Dieter Peter 
Published: January 2010

AbstractOsteoclasts are large, mobile, bone‐resorbing cells and play a critical role in bone remodeling and catabolic bone diseases. The major function of osteoclasts is to hydrolyze inorganic hydroxyapatite and degrade organic bone matrix, mainly collagen. For evaluation of differentiation to fully functional osteoclasts in vitro, a quantitative functional resorption assay is essential. Currently available commercial test systems are either based on the organic or the inorganic part of the bone matrix. The novel resorption assay presented here is based on decellularized osteoblast‐derived matrix. SaOS‐2 cells were used for the synthesis of a densely mineralized extracellular bone matrix (ECM) in α‐MEM medium, which strongly accelerates their matrix synthesis. After removal of the SaOS‐2 cells, osteoclast precursors are plated on the osteoblast‐derived matrix and stained by von Kossa. Subsequently, resorption pits were quantified by densitometry using an imaging program. Using this novel assay, we show that (i) RAW 264.7 cells resorbed the osteoblast‐derived matrix continuously from day 6 until day 9 of culture, a process that is dose dependent on the macrophage colony‐stimulating factor (M‐CSF) concentration, (ii) the resorption performance of RAW 264.7 was dose‐dependently inhibited by IFN‐γ, and (iii) the assay is working with primary human and mouse osteoclast precursors as well. In conclusion, this quantitative, functional, easy‐to‐use, inexpensive assay will advance analysis of osteoclast biology. J. Cell. Biochem. 109: 1025–1032, 2010. © 2010 Wiley‐Liss, Inc.
Improved myocardial perfusion in chronic diabetic mice by the up‐regulation of pLKB1 and AMPK signaling
Authors: Kusmic Claudia , L'Abbate Antonio , Sambuceti Gianmario , Drummond George , Barsanti Cristina , Matteucci Marco , Cao Jian , Piccolomini Francesco , Cheng Jennifer , Abraham Nader G. 
Published: January 2010

AbstractPrevious studies related impaired myocardial microcirculation in diabetes to oxidative stress and endothelial dysfunction. Thus, this study was aimed to determine the effect of up‐regulating pAMPK‐pAKT signaling on coronary microvascular reactivity in the isolated heart of diabetic mice. We measured coronary resistance in wild‐type and streptozotocin (STZ)‐treated mice, during perfusion pressure changes. Glucose, insulin, and adiponectin levels in plasma and superoxide formation, NOx levels and heme oxygenase (HO) activity in myocardial tissue were determined. In addition, the expression of HO‐1, 3‐nitrotyrosine, pLKB1, pAMPK, pAKT, and peNOS proteins in control and diabetic hearts were measured. Coronary response to changes in perfusion pressure diverged from control in a time‐dependent manner following STZ administration. The responses observed at 28 weeks of diabetes (the maximum time examined) were mimicked by L‐NAME administration to control animals and were associated with a decrease in serum adiponectin and myocardial pLKB1, pAMPK, pAKT, and pGSK‐3 expression. Cobalt protoporphyrin treatment to induce HO‐1 expression reversed the microvascular reactivity seen in diabetes towards that of controls. Up‐regulation of HO‐1 was associated with an increase in adiponectin, pLKB1, pAKT, pAMPK, pGSK‐3, and peNOS levels and a decrease in myocardial superoxide and 3‐nitrotyrosine levels. In the present study we describe the time course of microvascular functional changes during the development of diabetes and the existence of a unique relationship between the levels of serum adiponectin, pLKB1, pAKT, and pAMPK activation in diabetic hearts. The restoration of microvascular function suggests a new therapeutic approach to even advanced cardiac microvascular derangement in diabetes. J. Cell. Biochem. 109: 1033–1044, 2010. © 2010 Wiley‐Liss, Inc.
Impaired expression of genes regulating cholesterol efflux in human osteoarthritic chondrocytes
Authors: Tsezou Aspasia , Iliopoulos Dimitrios , Malizos Konstantinos N. , Simopoulou Theodora 
Published: January 2010

AbstractAltered lipid metabolism has been implicated as a critical player in osteoarthritis (OA). Our study aimed to investigate the expression of genes regulating cholesterol efflux in human chondrocytes and to study the effect of an LXR agonist on cholesterol efflux and lipid accumulation in osteoarthritic chondrocytes. ATP‐binding‐cassette transporter A1 (ABCA1), apolipoprotein A1 (ApoA1), and liver X receptors (LXRα and LXRβ) mRNA expression levels were evaluated using real‐time polymerase chain reaction (PCR) and ApoA1 protein levels by Western blot analysis in normal and osteoarthritic articular cartilage samples. Cholesterol efflux was evaluated in osteoarthritic chondrocytes radiolabeled with [1,2(n)‐3H] cholesterol after LXR treatment, while intracellular lipid accumulation was studied after Oil‐red‐O staining. Cholesterol efflux gene expressions were significantly lower in osteoarthritic cartilage compared to normal. Treatment of osteoarthritic chondrocytes with the LXR agonist TO‐901317 significantly increased ApoA1 and ABCA1 expression levels, as well as cholesterol efflux. Additionally, osteoarthritic chondrocytes presented intracellular lipids deposits, while no deposits were found after treatment with TO‐901317. Our findings suggest that impaired expression of genes regulating cholesterol efflux may be a critical player in osteoarthritis, while the ability of the LXR agonist to facilitate cholesterol efflux suggests that it may be a target for therapeutic intervention in osteoarthritis. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1033–1039, 2010
Rejuvenation of the inflammatory system stimulates fracture repair in aged mice
Authors: Xing Zhiqing , Lu Chuanyong , Hu Diane , Miclau Theodore , Marcucio Ralph S. 
Published: January 2010

AbstractAge significantly reduces the regenerative capacity of the skeleton, but the underlying causes are unknown. Here, we tested whether the functional status of inflammatory cells contributes to delayed healing in aged animals. We created chimeric mice by bone marrow transplantation after lethal irradiation. In this model, chondrocytes and osteoblasts in the regenerate are derived exclusively from host cells while inflammatory cells are derived from the donor. Using this model, the inflammatory system of middle‐aged mice (12 month old) was replaced by transplanted bone marrow from juvenile mice (4 weeks old), or age‐matched controls. We found that the middle‐aged mice receiving juvenile bone marrow had larger calluses and more bone formation during early stages and faster callus remodeling at late stages of fracture healing, indicating that inflammatory cells derived from the juvenile bone marrow accelerated bone repair in the middle‐aged animals. In contrast, transplanting bone marrow from middle‐aged mice to juvenile mice did not alter the process of fracture healing in juvenile mice. Thus, the roles of inflammatory cells in fracture healing may be age‐related, suggesting the possibility of enhancing fracture healing in aged animals by manipulating the inflammatory system. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1000–1006, 2010