bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nicotinamide phosphoribosyltransferase (Nampt) affects the lineage fate determination of mesenchymal stem cells: A possible cause for reduced osteogenesis and increased adipogenesis in older individuals
Authors: Li Yan , He Xu , Li Yulin , He Jiaxue , Anderstam Björn , Andersson Göran , Lindgren Urban 
Published: August 2011

Abstract
Human aging is associated with a progressive decline in bone mass and an accumulation of marrow fat. We found that osteoblast differentiation was reduced and adipocyte formation increased in bone marrow stromal cells derived from aged mice compared with young controls. The increased adipogenesis correlated with a relatively lower Sirt1 activity and a lower intracellular NAD+ concentration. We suppose that these effects were caused by age-related reduction of nicotinamide phosphoribosyltransferase (Nampt), the enzyme catalyzing NAD resynthesis from nicotinamide (NAM). In support of this hypothesis, treatment with Nampt inhibitor FK866 increased adipocyte formation and reduced mineralization in primary cultured bone marrow stromal cells. In addition, knockdown of Nampt in the mouse mesenchymal cell line C3H10T1/2 cells resulted in decreased Sirt1 activity and enhanced adipogenesis. Interestingly, although Nampt deficiency resulted in both decreased intracellular NAD+ and increased NAM, the cell differentiation could be controlled only by regulation of NAM. These results indicate that the lineage fate determination of mesenchymal stem cells (MSCs) is influenced by cell energy metabolism and points to a possible mechanism for the development of senile osteoporosis. Furthermore, we suggest that side effects on bone should be considered when evaluating the long-term safety of NAD-interfering pharmaceuticals. © 2011 American Society for Bone and Mineral Research
Hereditary vitamin D–resistant rickets (HVDRR) owing to a heterozygous mutation in the vitamin D receptor
Authors: Malloy Peter J , Zhou Yulin , Wang Jining , Hiort Olaf , Feldman David 
Published: August 2011

Abstract
Hereditary vitamin D–resistant rickets (HVDRR) is a rare autosomal recessive disease caused by mutations in the vitamin D receptor (VDR). Patients exhibit severe rickets and hypocalcemia. Heterozygous parents and siblings appear normal and exhibit no symptoms of the disease. We analyzed the VDR gene of a young girl who exhibited the clinical features of HVDRR without alopecia. The patient had clinical and radiographic features of rickets, hypocalcemia, and elevated serum concentrations of 1,25-dihydroxyvitamin D [1,25(OH)2D]. A single heterozygous missense mutation was found in the VDR gene that substituted glutamic acid with alanine at amino acid 420 (E420A). Sequencing of the girl's VDR cDNAs showed that the f/M1 allele contained the E420A mutation, whereas the F/M4 allele was completely normal. The girl's father, who was also heterozygous for the E420A mutation on the f/M1 allele, exhibited minor symptoms of vitamin D resistance. In contrast, the mother had no signs of the disease and had no mutations in her VDR gene. Both the girl and the father's skin fibroblasts showed resistance to 1,25(OH)2D3 by their severely reduced induction of CYP24A1 gene expression. In transactivation assays, the E420A mutant VDR showed dominant-negative activity towards the wild-type VDR. This is the first report that we are aware of describing a patient with HVDRR caused by a single heterozygous missense mutation in the VDR gene. The E420A mutant appears to act in a dominant-negative fashion, silencing the wild-type VDR and resulting in an attenuated response to 1,25(OH)2D3. © 2011 American Society for Bone and Mineral Research
A case of pyruvate dehydrogenase E1α subunit deficiency with antenatal brain dysgenesis demonstrated by prenatal sonography and magnetic resonance imaging
Authors: Tamaru Shunsuke , Kikuchi Akihiko , Takagi Kimiyo , Okuno Jiu , Ishikawa Kaori , Imada Shinya , Horikoshi Tsuguhiro , Goto Yu‐ichi , Hirabayashi Shinichi 
Published: August 2011

AbstractPrenatal depiction of brain dysgenesis in patients with pyruvate dehydrogenase complex (PDHc) deficiencies has been infrequently reported. As PDHc plays a critical role in the brain that obtains all of the energy from the aerobic oxidation of glucose, its deficiency is a severe inborn disorder of metabolism, which predominantly affects the nervous system. This report describes a case of PDHc deficiency with antenatal brain dysgenesis depicted in detail by fetal ultrasound and magnetic resonance imaging. This is the first case report clearly demonstrating the developing mechanism and time course of antenatal brain lesions in a patient with PDHc deficiency. © 2011 Wiley Periodicals,Inc. J Clin Ultrasound, 2011
Soft tissue chondromyxoid fibroma of the foot: Sonographic findings
Authors: Kim Hye Rin , Lee Sang Min , Ha Doo Hoe , Kang Haeyoun , Rho Ji Young 
Published: August 2011

AbstractChondromyxoid fibroma is a rare benign bone tumor, which represents less than 1% of primary bone tumors. However, chondromyxoid fibroma developing in the soft tissue is extremely rare. We report the sonographic findings in a case of soft tissue chondromyxoid fibroma in the foot confirmed pathologically. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound 40:109–111, 2012 2011
Characterization of N‐cadherin unbinding properties in non‐malignant (HCV29) and malignant (T24) bladder cells
Authors: Lekka Małgorzata , Gil Dorota , Dąbroś Wojciech , Jaczewska Justyna , Kulik Andrzej J. , Lekki Janusz , Stachura Zbigniew , Stachura Jerzy , Laidler Piotr 
Published: August 2011

AbstractThe expression of N‐cadherin, characteristic of various cancers, very often leads to changes in the cells' adhesive properties. Thus, we sought to find out if N‐cadherin expressed in various, but cancer‐related cells, differs in its functional properties that could contribute to variations in cells' phenotypes. In our work, measurements of an unbinding force of a single N‐cadherin molecule, probed with the same antibody both on a surface of living non‐malignant (HCV29) and malignant cells (T24) of bladder cancer, were carried out with the use of an atomic force microscopy. The results show the enhanced N‐cadherin level in T24 malignant cells (8.7% vs. 3.6% obtained for non‐malignant one), confirmed by the Western blot and the immunohistochemical staining. The effect was accompanied by changes in unbinding properties of an individual N‐cadherin molecule. Lower unbinding force values (26.1 ± 7.1 pN) in non‐malignant cells reveal less stable N‐cadherin complexes, as compared to malignant cells (61.7 ± 14.6 pN). This suggests the cancer‐related changes in a structure of the binding site of the antibody, located at the extracellular domain of N‐cadherin. Copyright © 2011 John Wiley & Sons, Ltd.
Constitutive activity and ligand‐dependent activation of the nuclear receptor CAR—insights from molecular dynamics simulations
Authors: Windshügel Björn , Poso Antti 
Published: August 2011

AbstractThe constitutive androstane receptor (CAR) possesses, unlike most other nuclear receptors, a pronounced basal activity in vitro whose structural basis is still not fully understood. Using comparative molecular dynamics simulations of CAR X‐ray crystal structures, we evaluated the molecular basis for constitutive activity and ligand‐dependent receptor activation. Our results suggest that a combination of van der Waals interactions and hydrogen bonds is required to maintain the activation helix in the active conformation also in absence of a ligand. Furthermore, we identified conformational rearrangements within the ligand‐binding pocket upon agonist binding and an influence of CAR inducers pregnanedione and CITCO on the helical conformation of the activation helix. Based on the results a model for ligand‐dependent CAR activation is suggested. Copyright © 2011 John Wiley & Sons, Ltd.
Analysis of observed variability and trends in numbers of frost days in Turkey for the period 1950–2010
Authors: Erlat Ecmel , Türkeş Murat 
Published: August 2011

AbstractThis study examines the climatology of annual frost days, and analyses the size and behaviour of the long‐term variability and trends in annual numbers of frost day at the 72 stations over Turkey from 1950 to 2010. The main results are summarized as follows: (1) The annual number of frost days has evidently decreased at most of the stations with some observed regional differences, (2) The decreasing trends are largest over the Eastern Anatolia, the Marmara regions and along the Mediterranean coastline. The meteorological stations located in the continental northeast and the easternmost parts of the Anatolian Peninsula, including Ardahan, Iǧdır and Van, show a negative linear trend with a rate of four days per decade, (3) As in other regions of the Earth, changes in number of frost days are very likely associated with changes in minimum air temperatures and increasing growing season lengths in Turkey, (4) The decreasing trends in number of frost days also indicated considerable decadal‐scale variability. This variability is very likely attributable to the large‐scale atmospheric circulation and atmospheric oscillations such as the Arctic Oscillation (AO) or North Atlantic Oscillation (NAO) and the North Sea‐Caspian Pattern, (5) Consequently, the long‐winter (DJFM) composites of number of frost days were examined for extreme phases of the AO index during the period 1950–2010 in order to assess the influence of atmospheric oscillations on year‐to‐year variability in number of frost days. According to the Cramer's tk test, winter number of frost days tended to increase significantly during the high (positive) index AO phase, while they tended to decrease significantly during the low (negative) index AO phase. These relationships are statistically significant at the 1% level at the majority of stations. Copyright © 2011 Royal Meteorological Society
Morphology of the human vertebral endplate
Authors: Rodriguez Azucena G. , Rodriguez‐Soto Ana E. , Burghardt Andrew J. , Berven Sigurd , Majumdar Sharmila , Lotz Jeffrey C. 
Published: August 2011

AbstractIt is presumed that poor intervertebral disc cell nutrition is a contributing factor in degeneration, and is exacerbated by vertebral endplate sclerosis. Yet, quantitative relationships between endplate morphology and degeneration are unavailable. We investigated how endplate bone microstructure relates to indices of disc degeneration, such as morphologic grade, proteoglycan content, and cell density. Intervertebral core samples [n = 96, 14 subjects, L1–L5 level, ages 35–85 (64 ± 16 years), degeneration grade 1 (n = 4), grade 2 (n = 32), grade 3 (n = 44), grade 4 (n = 10), grade 5 (n = 6)] that included subchondral bone, cartilage endplate, and adjacent nucleus were harvested from human cadaveric lumbar spines. The morphology of the vertebral endplate was analyzed using µCT and the adjacent nucleus tissue was collected for biochemical and cellular analyses. Relationships between vertebral endplate morphology and adjacent disc degeneration were analyzed. Contrary to the prevailing notion, vertebral endplate porosity increased between 50% and 130% and trabecular thickness decreased by between 20% and 50% with advancing disc degeneration (p < 0.05). We also observed that nucleus cell density increased (R2 = 0.33, p < 0.05) and proteoglycan content decreased (R2 = 0.47, p < 0.05) as the endplate became more porous. Our data suggest that endplate sclerosis is not a fundamental factor contributing to disc degeneration. Rather, the opposite was observed in our samples, as the endplate became progressively more porous with age and degeneration. Since ischemic disc cell behavior is commonly associated with degenerative change, this may be related to other factors such as the quality of vertebral capillaries, as opposed to decreased permeability of intervening tissues. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:280–287, 2012
Patients with patellofemoral pain exhibit elevated bone metabolic activity at the patellofemoral joint
Authors: Draper Christine E. , Fredericson Michael , Gold Garry E. , Besier Thor F. , Delp Scott L. , Beaupre Gary S. , Quon Andrew 
Published: August 2011

AbstractPatellofemoral pain is characterized by pain behind the kneecap and is often thought to be due to high stress at the patellofemoral joint. While we cannot measure bone stress in vivo, we can visualize bone metabolic activity using 18F NaF PET/CT, which may be related to bone stress. Our goals were to use 18F NaF PET/CT to evaluate whether subjects with patellofemoral pain exhibit elevated bone metabolic activity and to determine whether bone metabolic activity correlates with pain intensity. We examined 20 subjects diagnosed with patellofemoral pain. All subjects received an 18F NaF PET/CT scan of their knees. Uptake of 18F NaF in the patella and trochlea was quantified by computing the standardized uptake value and normalizing by the background tracer uptake in bone. We detected increased tracer uptake in 85% of the painful knees examined. We found that the painful knees exhibited increased tracer uptake compared to the pain‐free knees of four subjects with unilateral pain (P = 0.0006). We also found a correlation between increasing tracer uptake and increasing pain intensity (r2 = 0.55; P = 0.0005). The implication of these results is that patellofemoral pain may be related to bone metabolic activity at the patellofemoral joint. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:209–213, 2012
Evaluation of copper–1,3,5‐benzenetricarboxylate metal–organic framework (Cu‐MOF) as a selective sorbent for Lewis‐base analytes
Authors: Harvey Scott D. , Eckberg Alison D. , Thallapally Praveen K. 
Published: August 2011

AbstractThe metal–organic framework copper–1,3,5‐benzenetricarboxylate (Cu‐BTC) was evaluated for its ability to selectively interact with Lewis‐base analytes by examining retention on gas‐chromatographic columns packed with Chromosorb W HP that contained 3.0% SE‐30 along with various loadings of Cu‐BTC. Scanning electron microscopy images of the support material showed the characteristic Cu‐BTC crystals embedded in the SE‐30 coating on the diatomaceous support. The results indicated that the Cu‐BTC‐containing stationary phase had limited thermal stability (220°C) and strong general retention for analytes. Kováts index calculations showed selective retention (amounting to about 300 Kováts units) relative to n‐alkanes for many small Lewis‐base analytes on a column that contained 0.75% Cu‐BTC compared with an SE‐30 control. Short columns that contained lower loadings of Cu‐BTC (0.10%) allowed elution of nitroaromatics; however, selectivity was not observed for aromatic compounds (including nitroaromatics) or nitroalkanes. Observed retention characteristics are discussed.
Preparative separation of minor saponins from Platycodi Radix by high‐speed counter‐current chromatography
Authors: Ha In J. , Kang Minseok , Na Yun C. , Park Youmie , Kim Yeong S. 
Published: August 2011

AbstractPlatycosides (PSs), the saponins found in the root of Platycodon grandiflorum (Jacq.) A. DC. (Platycodi Radix), are typically composed of oleanene backbones with two side chains; one is a 3‐O‐glucose linked by a glycosidic bond, and the other is a 28‐O‐arabinose‐rhamnose‐xylose‐apiose linked by an ester bond. Minor saponins, acetylated isomers of the major saponin on either the 2″ or 3″ position of rhamnose, were isolated from Platycodi Radix using a multi‐step process including high‐speed counter‐current chromatography (HSCCC) and preparative reversed‐phase high‐performance liquid chromatography (RP‐HPLC). After the separation of the major components, the enriched minor saponin fraction was used for this study. A two‐phase solvent system consisting of chloroform–methanol–isopropanol–water (3:2:2:3, v/v) was used for HSCCC. HSCCC separation of the enriched minor saponin fraction yielded 2″‐O‐acetylplatycodin D, 3″‐O‐acetylpolygalacin D, 2″‐O‐acetylpolygalacin and a mixture of 3″‐O‐acetylplatycodin D and polygalacin D. The mixture fraction from HSCCC separation was further purified by preparative RP‐HPLC, giving 3″‐O‐acetylplatycodin D and polygalacin D at a purity of over 98.9%. The developed method provides the preparative and rapid separation of minor saponins in the crude extract of Platycodi Radix. To the best of our knowledge, this is the first on the separation of acetylated PSs by HSCCC.
Molecularly imprinted polymer microspheres for solid‐phase extraction of protocatechuic acid in Rhizoma homalomenae
Authors: Chen Fang‐Fang , Wang Guo‐Ying , Shi Yan‐Ping 
Published: August 2011

AbstractMolecularly imprinted polymers (MIPs) had been prepared by precipitation polymerization method using acrylamide as the functional monomer, ethylene glycol dimethacrylate as the cross‐linker, acetonitrile as the porogen solvent and protocatechuic acid (PA), one of phenolic acids, as the template molecule. The MIPs were characterized by scanning electron microscopy and Fourier transform infrared, and their performance relative to non‐imprinted polymers was assessed by equilibrium binding experiments. Six structurally similar phenolic acids, including p‐hydroxybenzoic acid, gallic acid, salicylic acid, syringic acid, vanillic acid, ferulic acid were selected to assess the selectivity and recognition capability of the MIPs. The MIPs were applied to extract PA from the traditional Chinese medicines as a solid‐phase extraction sorbent. The resultant cartridge showed that the MIPs have a good extraction performance and were able to selectively extract almost 82% of PA from the extract of Rhizoma homalomenae. Thus, the proposed molecularly imprinted‐solid phase extraction‐high performance liquid chromatography method can be successfully used to extract and analyse PA in traditional Chinese medicines.
A characterization of retracts in certain Fraïssé limits
Authors: Dolinka Igor 
Published: August 2011

AbstractAssuming certain conditions on a class \documentclass{article}\usepackage{amssymb,amsmath,mathrsfs}\begin{document}\pagestyle{empty}$\mathscr{C}$\end{document} of finitely generated first‐order structures admitting the model‐theoretical construction of a Fraïssé limit, we characterize retracts of such limits as algebraically closed structures in a class naturally related to \documentclass{article}\usepackage{amssymb,amsmath,mathrsfs}\begin{document}\pagestyle{empty}$\mathscr{C}$\end{document}. In this way we generalize an earlier description of retracts of the countably infinite random graph.
The PLA2G6 gene in early‐onset Parkinson's disease
Authors: Kauther Kai Michael , Höft Christine , Rissling Ida , Oertel Wolfgang H. , Möller Jens Carsten 
Published: August 2011

AbstractBackground:The definite etiology of neurodegenerative disorders such as Parkinson's disease (PD) is still unknown. Because of its role in the generation of reactive oxygen species and its association with neurodegeneration with brain iron accumulation, a possible involvement of calcium‐independent group VI phospholipase A2 (iPLA2‐VI) in the pathogenesis of PD has been proposed.Methods:In this study we analyzed all 17 exons of the PLA2G6 gene encoding iPLA2‐VI in a group of 102 discordant pairs with early‐onset Parkinson's disease (EOPD) and an additional sample of 166 EOPD patients and 155 unrelated controls.Results:The nonsynonymous single‐nucleotide polymorphisms (SNPs) 2339A>G (n = 2) and 2341G>A (n = 1) in 2 neighboring codons were found in 3 patients with typical L‐dopa‐responsive sporadic EOPD and in none of our controls, indicating a possible role of PLA2G6 in the pathogenesis of EOPD in rare cases.Conclusions:Future studies should investigate the prevalence of these SNPs in other PD populations and larger control groups and also address possible genetic alterations in the remaining parts of the PLA2G6 gene. © 2011 Movement Disorder Society
The Importance of Descriptor‐Based Clusterization in QSAR Models Development: Tyrosine Kinases Inhibitors as a Key Study
Authors: Marzaro Giovanni , Tonus Francesca , Brun Paola , Castagliuolo Ignazio , Guiotto Adriano , Chilin Adriana 
Published: August 2011

AbstractQuantitative Structure Activity Relationship (QSAR) is a well known cheminformatic tool for the discovery of novel biologically active compounds. However, when large and heterogeneous datasets are mined, it is not possible to derive a QSAR equation able to predict in a satisfactory manner the activity of the compounds. Thus, QSAR models are often inadequate for virtual screening purpose. Herein we present a novel approach to multitarget classification QSAR models, useful to assess the selectivity profile of the tyrosine kinases inhibitors. A descriptor‐based clusterization process was employed, that allowed the generation of models with high accuracies and independent from the chemical classification of the compounds (i.e. from the scaffold type). The herein proposed methodology can lead to QSAR models useful for virtual screening processes.
Mass spectrometry‐based quantification of myocardial protein adducts with acrolein in an in vivo model of oxidative stress
Authors: Wu Jianyong , Stevens Jan F. , Maier Claudia S. 
Published: August 2011

AbstractAcrolein (ACR) exposure leads to the formation of protein–ACR adducts. Protein modification by ACR has been associated with various chronic diseases including cardiovascular and neurodegenerative diseases. Here, we report an analytical strategy that enables the quantification of Michael‐type protein adducts of ACR in mitochondrial proteome samples using liquid chromatography in combination with tandem mass spectrometry and selected ion monitoring (LC‐MS/MS SRM) analysis. Our approach combines site‐specific identification and relative quantification at the peptide level of protein–ACR adducts in relation to the unmodified protein thiol pool. Treatment of 3‐month‐old rats with CCl4, an established in vivo model of acute oxidative stress, resulted in significant increases in the ratios of distinct ACR‐adducted peptides to the corresponding unmodified thiol‐peptides obtained from proteins that were isolated from cardiac mitochondria. The mitochondrial proteins that were found adducted by ACR were malate dehydrogenase, NADH dehydrogenase [ubiquinone] flavoprotein 1, cytochrome c oxidase subunit VIb isoform 1, ATP synthase d chain, and ADP/ATP translocase 1. The findings indicate that protein modification by ACR has potential value as an index of mitochondrial oxidative stress.
The preemptive swapping problem on a tree
Authors: Anily Shoshana , Gendreau Michel , Laporte Gilbert 
Published: August 2011

AbstractThis article considers the swapping problem on a tree. In this problem at most one object of some type is available at each vertex, and each vertex also requests at most one object of a given type. The total demand and the total supply of each object type are identical. The problem is to determine a minimum cost routing plan starting and ending at a prespecified vertex which is the depot, for a single vehicle of unit capacity and m object types, so that all vertex requests are satisfied. We consider the preemptive mode in which objects may be temporarily dropped along the way. It is shown that this problem is NP‐hard. A heuristic with a worst‐case performance ratio of 1.5 is developed. Finally, it is shown that the case where m = 1 is polynomially solvable. © 2011 Wiley Periodicals, Inc. NETWORKS, 2011