bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analyses of functional domains within the PF6 protein of the central apparatus reveal a role for PF6 sub‐complex members in regulating flagellar beat frequency
Authors: Goduti Daniel J. , Smith Elizabeth F. 
Published: January 2012

AbstractNumerous studies have indicated that each of the seven projections associated with the central pair of microtubules plays a distinct role in regulating eukaryotic ciliary/flagellar motility. Mutants which lack specific projections have distinct motility phenotypes. For example, Chlamydomonas pf6 mutants lack the C1a projection and have twitchy, non‐beating flagella. The C1a projection is a complex of proteins including PF6, C1a‐86, C1a‐34, C1a‐32, C1a‐18, and calmodulin. To define functional domains within PF6 and to potentially assign functions to specific C1a components, we generated deletion constructs of the PF6 gene and tested for their ability to assemble and rescue motility upon transformation of mutant pf6 cells. Our results demonstrate that domains near the carboxyl‐terminus of PF6 are essential for motility and/or assembly of the projection. The amino terminal half of PF6 is not required for C1a assembly; however, this region is important for stability of the C1a‐34, C1a‐32, and C1a‐18 sub‐complex and wild‐type beat frequency. Analysis of double mutants lacking the amino terminus of PF6 and outer dynein arms reveal that C1a may play a role in modulating both inner and outer dynein arm activity. © 2012 Wiley Periodicals, Inc
Novel 4‐Amino Bis‐pyridinium and Bis‐quinolinium Derivatives as Choline Kinase Inhibitors with Antiproliferative Activity against the Human Breast Cancer SKBR‐3 Cell Line
Authors: Gómez‐Pérez Verónica , McSorley Theresa , See Too Wei Cun , Konrad Manfred , Campos Joaquín M. 
Published: January 2012

AbstractCholine kinase (ChoK) is the first enzyme in the CDP‐choline pathway that synthesizes phosphatidylcholine, the major phospholipid in eukaryotic cell membranes. Human ChoK has three isoforms: ChoKα1, α2, and β. Specific inhibition of ChoKα has been reported to selectively kill tumor cells. In this study, ten new symmetrical bis‐pyridinium and bis‐quinolinium derivatives were synthesized and tested for their ability to inhibit human ChoKα2. These compounds have electron‐releasing groups at position 4 of the pyridinium or quinolinium rings. 1,1′‐[(Butane‐1,3‐diylbis(benzene‐1,4‐diylmethylene)]bis[4‐(4‐bromo‐N‐methylanilino)pyridinium)] dibromide and 1,1′‐(biphenyl‐3,3′‐diylmethylene)bis[7‐chloro‐4‐(perhydroazepine‐1‐yl)quinolinium] dibromide were identified as highly potent ChoK inhibitors with IC50 values of 80 nM. Kinetic enzymatic assays indicated a mixed and predominantly competitive mechanism of inhibition for these compounds, which exhibited strong antiproliferative activity (EC50 1 μM) against the human breast cancer SKBR3 cell line.
A novel method for retinoic acid administration reveals differential and dose‐dependent downregulation of Fgf3 in the developing inner ear and anterior CNS
Authors: Cadot Stephanie , Frenz Dorothy , Maconochie Mark 
Published: January 2012

AbstractEndogenous retinoic acid plays critical roles in normal vertebrate development, but can be teratogenic in excess. In mice, additional retinoic acid is administered by oral gavage or intraperitoneal injection. Here we evaluate a novel non‐invasive system for administering retinoic acid via chocolate/sugar pellets. We use this delivery system to examine the role of retinoic acid in regulating the expression of the fibroblast growth factor Fgf3, and find that the timing of retinoic acid treatment is critical for its effects on Fgf3 expression. Administration of increasing amounts of retinoic acid at 7.75 dpc leads to dose‐dependent downregulation of Fgf3 in the otocyst and changes in spatial expression in the hindbrain. Detailed analysis of the developing inner ear also reveals a lateralisation of Fgf3 expression with increasing retinoic acid dose that is dependent on timing of administration. We discuss how these data impact on current models of retinoic acid patterning of the otocyst. Developmental Dynamics 241:741–758, 2012. © 2012 Wiley Periodicals, Inc.
Synthesis of Isoxazole Triflones
Authors: Kawai Hiroyuki , Sugita Yutaka , Tokunaga Etsuko , Shibata Norio 
Published: January 2012

AbstractThe first practical synthesis of isoxazole triflones 3 (4‐trifluoromethanesulfonylisoxazoles, 4‐triflylisoxazoles) has been achieved by an operationally simple procedure consisting of the reaction between readily available α‐triflyl ketones 4 and imidoyl chlorides 5 in the presence of triethylamine. The present method provides the biologically attractive isoxazoles featuring a triflyl group at the 4‐position with a wide substrate scope in good to high yield in all cases.
Acclimation of life-history traits to experimental changes in environmental contaminant concentrations in brown bullhead (Ameiurus nebulosus)
Authors: Farwell Michelle , Drouillard Ken G. , Heath Daniel D. , Pitcher Trevor E. 
Published: January 2012

Abstract
One adaptive mechanism aquatic populations use to facilitate tolerance to environmental contaminants is acclimation. Polychlorinated biphenyls (PCBs) are a globally ubiquitous class of persistent organic contaminants that have been linked to reproductive impairments in fish. The authors used female brown bullhead (Ameiurus nebulosus) to test whether acclimation of reproductive life-history traits occurs in response to changes in sum PCB exposure. They compared egg diameter, gonadosomatic index (GSI), and fecundity of fish directly caught from wild populations exposed to a range of contaminant concentrations (acute), to those collected from the same populations a year before, which were placed in a clean environment to clear their contaminants throughout that year (cleared). Sum PCB concentrations were also determined for each individual. Brown bullhead from acute treatments had significantly greater sum PCB concentrations compared with cleared treatments. Egg diameter and GSI metrics were greater in cleared treatments compared with acute treatments (by 6 and 14%, respectively). Treatment effect (i.e., acute or cleared), as opposed to where the fish were collected from, accounts for 72 to 89% of the variation in the reproductive life-history trait variables. No difference in fecundity was found between acute and cleared treatments. The authors found support that acclimation of reproductive life-history traits occurs to changes in sum PCB concentration. To their knowledge, the present study is the first experimental test of acclimation responses of female life-history traits to contaminants in wild populations. Environ. Toxicol. Chem. 2012;31:863–869. © 2012 SETAC
Testing hypotheses on the resistance to metals by Daphnia longispina: Differential acclimation, endpoints association, and fitness costs
Authors: Saro Liliana , Lopes Isabel , Martins Nelson , Ribeiro Rui 
Published: January 2012

Abstract
Pollution by metals may lead to an increased tolerance in the exposed population through adaptive microevolution, with resistant genotypes becoming more abundant than in reference sites. This work investigated the outcomes associated with selection for resistance by testing three hypotheses to assess the following: Do resistant versus sensitive clonal lineages of Daphnia longispina differentially acclimate to metals during a long-term sublethal exposure, is there a significant correlation between lethal and sublethal responses, and does resistance to metals entail costs to fitness under uncontaminated conditions? No evidence of acclimation was observed. The median effective dilutions of acid mine drainage for reproduction were similar for successive broods within clones during long-term exposures. Lethal and sublethal responses were not correlated, indicating that mechanisms regulating the two types of response were more than likely different. Finally, fitness costs associated with the resistance to lethal levels of metals were not detected, but resistance to sublethal levels of Cu was found to be correlated with a lower intrinsic growth rate under control conditions. Environ. Toxicol. Chem. 2012;31:909–915. © 2012 SETAC
Intracellular Na+ concentration influences short‐term plasticity of glutamate transporter‐mediated currents in neocortical astrocytes
Authors: Unichenko Petr , Myakhar Olga , Kirischuk Sergei 
Published: January 2012

AbstractFast synaptic transmission requires a rapid clearance of the released neurotransmitter from the extracellular space. Glial glutamate transporters (excitatory amino acid transporters, EAATs) strongly contribute to glutamate removal. In this work, we investigated the paired‐pulse plasticity of synaptically activated, glutamate transporter‐mediated currents (STCs) in cortical layer 2/3 astrocytes. STCs were elicited by local electrical stimulation in layer 4 in the presence of ionotropic glutamate (AMPA and NMDA), GABAA, and GABAB receptor antagonists. In experiments with low [Na+]i (5 mM) intrapipette solution, STCs elicited by paired‐pulse stimulation demonstrated paired‐pulse facilitation (PPF) at short (<250 ms) interstimulus intervals (ISIs) and paired‐pulse depression at longer ISIs. In experiments with close to physiological, high [Na+]i (20 mM) intrapipette solution, PPF of STCs at short ISIs was significantly reduced. In addition, the STC kinetics was slowed in the presence of high [Na+]i. Exogenous GABA increased astrocytic [Na+]i, reduced the mean STC amplitude, decreased PPF at short ISIs, and slowed STC kinetics. All GABA‐induced changes were blocked by NO‐711 and SNAP‐5114, GABA transporter (GATs) antagonists. In experiments with the low intrapipette solution, GAT blockade under control conditions decreased PPF at short ISIs both at room and at near physiological temperatures. Dialysis of single astrocyte with low [Na+]i solution increased the amplitude and reduced PPR of evoked field potentials recorded in the vicinity of the astrocyte. We conclude that (1) endogenous GABA via GATs may influence EAAT functioning and (2) astrocytic [Na+]i modulates the short‐term plasticity of STCs and in turn the efficacy of glutamate removal. © 2012 Wiley Periodicals, Inc.
Prevalence of human papillomavirus in oropharyngeal and nonoropharyngeal head and neck cancer—systematic review and meta‐analysis of trends by time and region
Authors: Mehanna Hisham , Beech Tom , Nicholson Tom , El‐Hariry Iman , McConkey Christopher , Paleri Vinidh , Roberts Sally 
Published: January 2012

AbstractBackgroundLittle information has been reported on regional and time trends of human papillomavirus (HPV) prevalence rates of oropharyngeal cancer (OPC) and non‐OPC.MethodsThe study consisted of a systematic review and meta‐analysis using random effects logistic regression models.ResultsOverall HPV prevalence in OPC (47.7%; 95% confidence interval [CI], 42.9–52.5%) increased significantly over time: from 40.5% (95% CI, 35.1–46.1) before 2000, to 64.3% (95% CI, 56.7–71.3) between 2000 and 2004, and 72.2% (95% CI, 52.9–85.7) between 2005 and 2009 (p < .001). Prevalence increased significantly in North America and Europe, and the significant gap between them that existed before 2000 (50.7% vs 35.3%, respectively, p = .008) has now disappeared (69.7% vs 73.1%, respectively, p = .8). Prevalence in non‐OPC (21.8%; 95% CI, 18.9–25.1%) has not increased over time (p = .97)ConclusionsThe sharp increase in the proportion of HPV‐positive OPC over the last decade has occurred at a faster rate in Europe compared with that in North America. In contrast, the relatively low prevalence of HPV in non‐OPC remains unchanged. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
BMP‐2 inhibits tumor growth of human renal cell carcinoma and induces bone formation
Authors: Wang Lin , Park Paul , Zhang Huina , La Marca Frank , Claeson Amy , Than Khoi , Rahman Shayan , Lin Chia‐Ying 
Published: January 2012

AbstractBone morphogenetic protein‐2 (BMP‐2), a member of the transforming growth factor superfamily, has been shown to have inhibitory effect on many tumor types. However, the effect of BMP‐2 on human renal cell carcinoma (RCC) is still unknown. We previously showed that BMP‐2 inhibits tumorigenicity of cancer stem cells in human osteosarcoma OS99‐1 cells. Our study investigates the effect of BMP‐2 on human RCC using ACHN and Caki‐2 cell lines. Three types of BMP receptors were found to be expressed in ACHN and Caki‐2 cells. In vitro, BMP‐2 was found to inhibit the growth of ACHN and Caki‐2 cells. The antiproliferative effect seems to be due to cell cycle arrest in the G1 phase, which was revealed by flow cytometry analysis. Using reverse transcriptase polymerase chain reaction analysis, we demonstrated BMP‐2 upregulated osteogenic markers Runx‐2 and Collagen Type I gene expression in ACHN and Caki‐2 cells. Treatment of ACHN and Caki‐2 cells with BMP‐2 induced a rapid phosphorylation of Smad1/5/8. In vivo, all animals receiving low number of ACHN (1 × 104) and Caki‐2 (5 × 104) cells treated with 30 μg of BMP‐2 per animal showed limited tumor growth with significant bone formation, whereas untreated cells developed large tumor masses without bone formation in immunodeficient non‐obese diabetic (NOD)/severe combined immunodeficient (SCID) mice. These results suggest that BMP‐2 inhibits growth of RCC as well as causes induction of osseous bone formation. Further research is needed to determine the relationship between inhibition of cell proliferation and bone induction.
Impaction‐modified densely sintered yttria‐stabilized tetragonal zirconium dioxide: Methodology, surface structure, and bond strength>
Authors: Papia Evaggelia , Zethraeus Johan , Ransbäck Per‐Åke , Wennerberg Ann , Vult von Steyern Per 
Published: January 2012

AbstractThe objectives of the study were to describe a novel method for producing zirconium dioxide specimens with a cementation surface that allows adhesive cementation techniques, to describe the surface structure and to evaluate the bond strength. Forty‐eight pairs of specimens were fabricated and adhesively luted together. Three different surfaces were tested: impaction‐modified surfaces created by using glass granules (G), impaction‐modified surfaces created by using polymer granules (P) and a nonmodified control surface (C). Two bonding systems were used, Variolink®II (VA) or Panavia™F 2.0 (PA). During the different fabrication steps, the surfaces were examined under light microscope and analyzed with an optical interferometer. All groups were thermocycled and subjected to shear bond strength test. The groups with modified cementation surfaces showed significantly higher shear bond strength: 34.9 MPa (VA‐G), 30.9 MPa (VA‐P), 29.6 MPa (PA‐P), and 26.1 MPa (PA‐G) compared with the relevant control group: 20.5 MPa (VA‐C) and 17.8 MPa (PA‐C). The groups with surface modification showed a rougher surface structure and significantly fewer fractures between the cement and the zirconium dioxide surfaces compared to the control groups where all failures were adhesive. Impaction modification with an impaction medium pressed into the cementation surface of zirconium dioxide‐based reconstructions can be used in combination with an additive production technique to increase bond strength. Both modification techniques described in the study result in a rougher surface structure and higher shear bond strength compared to the control groups. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Silorane resin supports proliferation, differentiation, and mineralization of MLO‐A5 bone cells in vitro and bone formation in vivo
Authors: Eick J. David , Barragan‐Adjemian Cielo , Rosser Jennifer , Melander Jennifer R. , Dusevich Vladimir , Weiler Rachel A. , Miller Bradley D. , Kilway Kathleen V. , Dallas Mark R. , Bi Lianxing , Nalvarte Elisabet L. , Bonewald Lynda F. 
Published: January 2012

AbstractMethyl methacrylate used in bone cements has drawbacks of toxicity, high exotherm, and considerable shrinkage. A new resin, based on silorane/oxirane chemistry, has been shown to have little toxicity, low exotherm, and low shrinkage. We hypothesized that silorane‐based resins may also be useful as components of bone cements as well as other bone applications and began testing on bone cell function in vitro and in vivo. MLO‐A5, late osteoblast cells, were exposed to polymerized silorane (SilMix) resin (and a standard polymerized bisGMA/TEGDMA methacrylate (BT) resin and compared to culture wells without resins as control. A significant cytotoxic effect was observed with the BT resin resulting in no cell growth, whereas in contrast, SilMix resin had no toxic effects on MLO‐A5 cell proliferation, differentiation, nor mineralization. The cells cultured with SilMix produced increasing amounts of alkaline phosphatase (1.8‐fold) compared to control cultures. Compared to control cultures, an actual enhancement of mineralization was observed in the silorane resin‐containing cultures at days 10 and 11 as determined by von Kossa (1.8–2.0 fold increase) and Alizarin red staining (1.8‐fold increase). A normal bone calcium/phosphate atomic ratio was observed by elemental analysis along with normal collagen formation. When used in vivo to stabilize osteotomies, no inflammatory response was observed, and the bone continued to heal. In conclusion, the silorane resin, SilMix, was shown to not only be non cytototoxic, but actually supported bone cell function. Therefore, this resin has significant potential for the development of a nontoxic bone cement or bone stabilizer. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Supplementation of collagen scaffolds with SPARC to facilitate mineralization
Authors: Pataquiva‐Mateus A. Y. , Wu H‐C. , Lucchesi C. , Ferraz M. P. , Monteiro F. J. , Spector M. 
Published: January 2012

AbstractThe extracellular matrix‐associated protein, SPARC (Secreted Protein Acidic and Rich in Cysteine) is known to play a role in the mineralization of collagen in bone formation. The objectives of this study were to determine: 1) if SPARC supplementation of type 1 collagen scaffolds in vitro facilitated the binding of pre‐formed HA nanoparticles added to the scaffolds; 2) if SPARC supplementation of the scaffolds enhanced the uptake of calcium and phosphorus from calcium phosphate solutions; and 3) if pretreatment in a calcium phosphate solution enhanced the subsequent binding of the nanoparticles. A related objective was to begin to determine the behavior of mesenchymal stem cells in the scaffolds when the constructs were grown in osteogenic medium. The calcium and phosphorus contents of the scaffolds were evaluated by inductively coupled plasma analysis, and the elastic modulus of the scaffolds determined by unconfined compression testing. Scaffolds were seeded with goat bone marrow‐derived mesenchymal stem cells and the cell‐seeded constructs grown in osteogenic medium. Supplementation of the scaffolds with as little as 0.008 % SPARC (by wt. of collagen) resulted in an increase in the binding of hydroxyapatite nanoparticles to the scaffold, but had no effect on incorporation of calcium or phosphorus from a calcium phosphate solution. The incorporation of hydroxyapatite nanoparticles into the scaffolds did not result in an increase in modulus. Supplementation of the scaffolds with SPARC and the increase in the binding of hydroxyapatite nanoparticles did not affect the proliferation of mesenchymal stem cells. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012
Hybrid particle‐field molecular dynamics simulations: Parallelization and benchmarks
Authors: Zhao Ying , De Nicola Antonio , Kawakatsu Toshihiro , Milano Giuseppe 
Published: January 2012

AbstractThe parallel implementation of a recently developed hybrid scheme for molecular dynamics (MD) simulations (Milano and Kawakatsu, J Chem Phys 2009, 130, 214106) where self‐consistent field theory (SCF) and particle models are combined is described. Because of the peculiar formulation of the hybrid method, considering single particles interacting with density fields, the most computationally expensive part of the hybrid particle‐field MD simulation can be efficiently parallelized using a straightforward particle decomposition algorithm. Benchmarks of simulations, including comparisons of serial MD and MD‐SCF program profiles, serial MD‐SCF and parallel MD‐SCF program profiles, and parallel benchmarks compared with efficient MD program GROMACS 4.5.4 are tested and reported. The results of benchmarks indicate that the proposed parallelization scheme is very efficient and opens the way to molecular simulations of large scale systems with reasonable computational costs. © 2012 Wiley Periodicals, Inc.
Potential of mean force of water–proton bath and molecular dynamic simulation of proteins at constant pH
Authors: Vorobjev Yury N. 
Published: January 2012

AbstractAn advanced implicit solvent model of water–proton bath for protein simulations at constant pH is presented. The implicit water–proton bath model approximates the potential of mean force of a protein in water solvent in a presence of hydrogen ions. Accurate and fast computational implementation of the implicit water–proton bath model is developed using the continuum electrostatic Poisson equation model for calculation of ionization equilibrium and the corrected MSR6 generalized Born model for calculation of the electrostatic atom–atom interactions and forces. Molecular dynamics (MD) method for protein simulation in the potential of mean force of water–proton bath is developed and tested on three proteins. The model allows to run MD simulations of proteins at constant pH, to calculate pH‐dependent properties and free energies of protein conformations. The obtained results indicate that the developed implicit model of water–proton bath provides an efficient way to study thermodynamics of biomolecular systems as a function of pH, pH‐dependent ionization‐conformation coupling, and proton transfer events. © 2012 Wiley Periodicals, Inc.
Recollection of negative information in posttraumatic stress disorder
Authors: Tapia Géraldine , Clarys David , Bugaiska Aurélia , El‐Hage Wissam 
Published: January 2012

AbstractThe purpose of the present study was to investigate the effects of posttraumatic stress disorder (PTSD) associated with the effects of emotional valence on recall processes in recognition memory. Patients suffering from PTSD (n = 15) were compared with 15 nontraumatized patients with anxious and depressive symptoms and with 15 nontraumatized controls on the remember/know paradigm using negative, positive, and neutral words. The PTSD group remembered more negative words than the nontraumatized controls, F(1, 42) = 7.20, p = .01, but there was no difference between those with PTSD and those with anxiety or depression, F(1, 42) = 2.93, p = .09, or between the latter and controls, F(1, 42) < 1. This study did not allow us to determine whether this recollection bias for negative information was specific to the PTSD status or was triggered by the greater level of anxiety displayed in this group.