bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cellular uptake and imaging studies of gadolinium‐loaded single‐walled carbon nanotubes as MRI contrast agents
Authors: Tang Annie M. , Ananta Jeyarama S. , Zhao Hong , Cisneros Brandon T. , Lam Edmund Y. , Wong Stephen T. , Wilson Lon J. , Wong Kelvin K. 
Published: December 2010

AbstractWe quantify here, for the first time, the intracellular uptake (J774A.1 murine macrophage cells) of gadolinium‐loaded ultra‐short single‐walled carbon nanotubes (gadonanotubes or GNTs) in a 3 T MRI scanner usingR2andR2* mappingin vitro. GNT‐labeled cells exhibited high and linear changes in net transverse relaxations (ΔR2and ΔR) with increasing cell concentration. The measured ΔR2* were about three to four times greater than the respective ΔR2for each cell concentration. The intracellular uptake of GNTs was validated with inductively coupled plasma optical emission spectrometry (ICP‐OES), indicating an average cellular uptake of 0.44 ± 0.09 pg Gd per cell or 1.69 × 109Gd3+ions per cell. Cell proliferation MTS assays demonstrated that the cells were effectively labeled, without cytotoxicity, for GNTs concentrations ≤28 µMGd.In vivorelaxometry of a subcutaneously‐injected GNT‐labeled cell pellet in a mouse was also demonstrated at 3 T. Finally, the pronouncedR2* effect of GNT‐labeled cells enabled successfulin vitrovisualization of labeled cells at 9.4 T. Copyright © 2010 John Wiley & Sons, Ltd.
Epidermal growth factor down‐regulates the expression of neutrophil gelatinase‐associated lipocalin (NGAL) through E‐cadherin in pancreatic cancer cells
Authors: Tong Zhimin , Chakraborty Subhankar , Sung Bokyung , Koolwal Pooja , Kaur Sukhwinder , Aggarwal Bharat B. , Mani Sendurai A. , Bresalier Robert S. , Batra Surinder K. , Guha Sushovan 
Published: December 2010

AbstractBACKGROUND:The authors previously reported that neutrophil gelatinase‐associated lipocalin (NGAL) overexpression significantly blocked invasion and angiogenesis of pancreatic ductal adenocarcinoma (PDAC). They also demonstrated a loss of NGAL expression in the advanced stages of PDAC. However, little is known regarding the mechanisms of NGAL regulation in PDAC. Because the epidermal growth factor (EGF)‐EGF receptor (EGFR) axis is up‐regulated significantly in PDAC, they examined EGF‐mediated NGAL regulation in these cells.METHODS:The NGAL‐positive cell lines AsPC‐1 and BxPC‐3 were used as a model system. Quantitative real‐time polymerase chain reaction (RT‐PCR), Western blot analysis, and immunofluorescence studies were used to investigate EGF‐mediated effects on NGAL expression. E‐cadherin expression was manipulated using lentiviral overexpression or small hairpin RNA constructs. NGAL promoter activity was assessed by luciferase‐reporter assay and electrophoretic mobility shift assay.RESULTS:NGAL expression was positively associated with tumor differentiation and was down‐regulated significantly after EGF treatment along with a concomitant reduction of E‐cadherin expression in PDAC cells. E‐cadherin down‐regulation was partly through the EGFR‐dependent mitogen‐activated protein kinase (MEK)/extracellular signal‐regulated kinase (ERK) (MEK‐ERK) signaling pathway. In addition, E‐cadherin down‐regulation reduced NGAL expression in PDAC cells, whereas overexpression of E‐cadherin led to increased NGAL expression and partly rescued the inhibition of NGAL expression by EGF. Furthermore, EGF, in part through E‐cadherin, reduced NGAL promoter activity by blocking nuclear factor κB (NF‐κB) activation.CONCLUSIONS:The current study demonstrated for the first time that EGF potently blocked NGAL expression in PDAC cells. This effect was mediated in part through activation of the EGFR‐MEK‐ERK signaling pathway, which, in turn, down‐regulated E‐cadherin with a subsequent reduction in NF‐κB activation. These findings illustrate a novel mechanism by which EGF regulates NGAL expression in PDAC. Cancer 2011;. © 2010 American Cancer Society.
Gas‐Phase Photodissociation of CH3CHBrCOCl at 248 nm: Detection of Molecular Fragments by Time‐Resolved FT‐IR Spectroscopy
Authors: Liu Chia‐Yun , Tsai Ming‐Tsang , Tsai Po‐Yu , Liu Yu‐Ting , Chen Si Ying , Chang Agnes Hsiu Hwa , Lin King‐Chuen 
Published: December 2010

AbstractBy employing time‐resolved Fourier transform infrared emission spectroscopy, the fragments HCl (v=1–3), HBr (v=1), and CO (v=1‐3) are detected in one‐photon dissociation of 2‐bromopropionyl chloride (CH3CHBrCOCl) at 248 nm. Ar gas is added to induce internal conversion and to enhance the fragment yields. The time‐resolved high‐resolution spectra of HCl and CO were analyzed to determine the rovibrational energy deposition of 10.0±0.2 and 7.4±0.6 kcal mol−1, respectively, while the rotational energy in HBr is evaluated to be 0.9±0.1 kcal mol−1. The branching ratio of HCl(v>0)/HBr(v>0) is estimated to be 1:0.53. The bond selectivity of halide formation in the photolysis follows the same trend as the halogen atom elimination. The probability of HCl contribution from a hot Cl reaction with the precursor is negligible according to the measurements of HCl amount by adding an active reagent, Br2, in the system. The HCl elimination channel under Ar addition is verified to be slower by two orders of magnitude than the Cl elimination channel. With the aid of ab initio calculations, the observed fragments are dissociated from the hot ground state CH3CHBrCOCl. A two‐body dissociation channel is favored leading to either HCl+CH3CBrCO or HBr+CH2CHCOCl, in which the CH3CBrCO moiety may further undergo secondary dissociation to release CO.
Extracting Individual Contributions From Their Mixture: A Blind Source Separation Approach
Authors: Dudok de Wit T. 
Published: December 2010

AbstractMultipoint or multichannel observations in plasmas can frequently be modelled as an instantaneous mixture of contributions (waves, emissions, …) of different origins. Recovering the individual sources from their mixture then becomes one of the key objectives. However, unless the underlying mixing processes are well known, these situations lead to heavily underdetermined problems. Blind source separation aims at disentangling such mixtures with the least possible prior information on the sources and their mixing processes. Several powerful approaches have recently been developed, which can often provide new or deeper insight into the underlying physics.This tutorial paper briefly discusses some possible applications of blind source separation to the field of plasma physics, in which this concept is still barely known. Two examples are given. The first shows how concurrent processes in the dynamical response of the electron temperature in a tokamak can be separated. The second example deals with solar spectral imaging in the Extreme UV and shows how empirical temperature maps can be built (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The GTPase Rem2 regulates synapse development and dendritic morphology
Authors: Ghiretti Amy E. , Paradis Suzanne 
Published: December 2010

AbstractRem2 is a member of the Rad/Rem/Rem2/Gem/Kir subfamily of small Ras‐like GTPases that was identified as an important mediator of synapse development. We performed a comprehensive, loss‐ of‐function analysis of Rem2 function in cultured hippocampal neurons using RNAi to substantially decrease Rem2 protein levels. We found that knockdown of Rem2 decreases the density and maturity of dendritic spines, the primary site of excitatory synapses onto pyramidal neurons in the hippocampus. Knockdown of Rem2 also alters the gross morphology of dendritic arborizations, increasing the number of dendritic branches without altering total neurite length. Thus, Rem2 functions to inhibit dendritic branching and promote the development of dendritic spines and excitatory synapses. Interestingly, binding to the calcium‐binding protein calmodulin is required for the Rem2 regulation of dendritic branching. However, this interaction is completely dispensable for synapse development. Overall, our results suggest that Rem2 regulates dendritic branching and synapse development via distinct and overlapping signal transduction pathways. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 71: 374–389, 2011
Adulterants in illicit drugs: a review of empirical evidence
Authors: Cole Claire , Jones Lisa , McVeigh Jim , Kicman Andrew , Syed Qutub , Bellis Mark 
Published: December 2010

AbstractWidespread public perception is that illicit drugs contain substances that are a serious risk to health, even though adulterants are often not considered in clinical or forensic toxicology. This review attempts to present an evidence‐based overview of adulterants in illicit drugs, and their associated toxicity. Adulterants are deliberately added to increase bulk, enhance or mimic a pharmacological effect, or to facilitate drug delivery. Those present unintentionally are as a result of poor manufacturing techniques. From the reports gathered, adulterants are predominantly substances which are readily available, commonly being caffeine, procaine, paracetamol, and sugars. These are likely to have minimal impact on users' health at low dosages. Other adulterants, particularly in injectable drugs, have the potential to cause serious health issues, but the quantities reported, such as strychnine in heroin, are not life‐threatening. The most commonly identified bacterial contaminants identified are Bacillus and Clostridium species. When death or serious illness due to adulteration occurs, circulation of information is particularly vital, such as in the USA regarding heroin and cocaine adulterated with fentanyl, and in Scotland recently regarding anthrax contaminated heroin.The complex interactions of supply, demand, and control of illicit drugs have a tangible impact on their adulteration. Continuing vigilance and the circulation of information is, therefore, desirable as a public health issue. As part of that strategy, analyses performed for adulterants needs to be encouraged, which are considerably limited in number and scope at the moment. Copyright © 2010 John Wiley & Sons, Ltd.
High sensitive analysis of steroids in doping control using gas chromatography/time‐of‐flight mass‐spectrometry
Authors: Revelsky A. I. , Samokhin A. S. , Virus E. D. , Rodchenkov G. M. , Revelsky I. A. 
Published: December 2010

AbstractThe method of high sensitive gas chromatographic/time‐of‐flight mass‐spectrometric (GC/TOF‐MS) analysis of steroids was developed. Low‐resolution TOF‐MS instrument (with fast spectral acquisition rate) was used. This method is based on the formation of the silyl derivatives of steroids; exchange of the reagent mixture (pyridine and N,O‐bis(trimethylsilyl)trifluoroacetamide (BSTFA)) for tert‐butylmethylether; offline large sample volume injection of this solution based on sorption concentration of the respective derivatives from the vapour‐gas mixture flow formed from the solution and inert gas flows; and entire analytes solvent‐free concentrate transfer into the injector of the gas chromatograph. Detection limits for 100 µl sample solution volume were 0.5–2 pg/µl (depending on the component). Application of TOF‐MS model ‘TruTOF’ (Leco, St Joseph, MO, USA) coupled with gas chromatograph and ChromaTOF software (Leco, St Joseph, MO, USA) allowed extraction of the full mass spectra and resolving coeluted peaks. Due to use of the proposed method (10 µl sample aliquot) and GC/TOF‐MS, two times more steroid‐like compounds were registered in the urine extract in comparison with the injection of 1 µl of the same sample solution. Copyright © 2010 John Wiley & Sons, Ltd.
Characterization, thermal stability studies, and analytical method development of Paromomycin for formulation development
Authors: Khan Wahid , Kumar Neeraj 
Published: December 2010

AbstractParomomycin (PM) is an aminoglycoside antibiotic, first isolated in the 1950s, and approved in 2006 for treatment of visceral leishmaniasis. Although isolated six decades back, sufficient information essential for development of pharmaceutical formulation is not available for PM.The purpose of this paper was to determine thermal stability and development of new analytical method for formulation development of PM. PM was characterized by thermoanalytical (DSC, TGA, and HSM) and by spectroscopic (FTIR) techniques and these techniques were used to establish thermal stability of PM after heating PM at 100, 110, 120, and 130 °C for 24 h. Biological activity of these heated samples was also determined by microbiological assay. Subsequently, a simple, rapid and sensitive RP‐HPLC method for quantitative determination of PM was developed using pre‐column derivatization with 9‐fluorenylmethyl chloroformate. The developed method was applied to estimate PM quantitatively in two parenteral dosage forms.PM was successfully characterized by various stated techniques. These techniques indicated stability of PM for heating up to 120 °C for 24 h, but when heated at 130 °C, PM is liable to degradation. This degradation is also observed in microbiological assay where PM lost ∼30% of its biological activity when heated at 130 °C for 24 h. New analytical method was developed for PM in the concentration range of 25–200 ng/ml with intra‐day and inter‐day variability of < 2%RSD. Characterization techniques were established and stability of PM was determined successfully. Developed analytical method was found sensitive, accurate, and precise for quantification of PM. Copyright © 2010 John Wiley & Sons, Ltd.
Hemodynamic patterning of the avian atrioventricular valve
Authors: Yalcin Huseyin C. , Shekhar Akshay , McQuinn Tim C. , Butcher Jonathan T. 
Published: December 2010

AbstractIn this study, we develop an innovative approach to rigorously quantify the evolving hemodynamic environment of the atrioventricular (AV) canal of avian embryos. Ultrasound generated velocity profiles were imported into Micro‐Computed Tomography generated anatomically precise cardiac geometries between Hamburger‐Hamilton (HH) stages 17 and 30. Computational fluid dynamic simulations were then conducted and iterated until results mimicked in vivo observations. Blood flow in tubular hearts (HH17) was laminar with parallel streamlines, but strong vortices developed simultaneous with expansion of the cushions and septal walls. For all investigated stages, highest wall shear stresses (WSS) are localized to AV canal valve–forming regions. Peak WSS increased from 19.34 dynes/cm2 at HH17 to 287.18 dynes/cm2 at HH30, but spatiotemporally averaged WSS became 3.62 dynes/cm2 for HH17 to 9.11 dynes/cm2 for HH30. Hemodynamic changes often preceded and correlated with morphological changes. These results establish a quantitative baseline supporting future hemodynamic analyses and interpretations. Developmental Dynamics, 2011. © 2010 Wiley‐Liss, Inc.
β8 integrin and band 4.1B cooperatively regulate morphogenesis of the embryonic heart
Authors: Jung Youngsin , Kissil Joseph L. , McCarty Joseph H. 
Published: December 2010

AbstractMorphogenesis of the heart is regulated by various cues, including growth factors and extracellular matrix (ECM) proteins. The mechanisms by which cardiac cells properly integrate these cues to regulate growth, differentiation, and migration remain poorly understood. Here we have used genetic strategies in mice to identify αvβ8 integrin and its cytoskeletal adaptor protein, Band 4.1B, as essential regulators of cardiac morphogenesis. We demonstrate that approximately 60% of mouse embryos genetically null for β8 integrin and Band 4.1B display cardiovascular phenotypes and die by E11.5. This premature death is due, in part, to defective development of the cardiac outflow tract (OFT), with reduced expression of smooth muscle α‐actin (SMAα‐actin) in OFT cells derived from the cardiac neural crest. These data are the first to identify cell adhesion and signaling pathways regulated by αvβ8 integrin and Band 4.1B as essential for normal formation and function of the heart during embryogenesis. Developmental Dynamics, 2011. © 2010 Wiley‐Liss, Inc.
The dynamic gene expression patterns of transcription factors constituting the sea urchin aboral ectoderm gene regulatory network
Authors: Chen Jen‐Hao , Luo Yi‐Jyun , Su Yi‐Hsien 
Published: December 2010

AbstractThe temporal and spatial expression patterns of regulatory genes are required for building a gene regulatory network (GRN). The current ectoderm GRN model for the sea urchin embryo includes pregastrular specification functions in the oral (OE) and aboral ectoderm (AE). Unlike the OE, which is resolved into several subdomains, the AE is considered a simpler territory due to the lack of detailed gene expression studies in this territory. Here, we perform temporal and spatial gene expression studies on the eight transcription factor genes constituting the AE GRN. Based on the differential gene expression patterns, we conclude that the AE contains at least three subdomains at the mesenchyme blastula stage. We also performed immunostaining for pSmad1/5/8 to monitor the activation of the BMP signaling pathway. The dynamic changes in the expression patterns of these transcription factor genes and the nuclearization of pSmad1/5/8 may provide a foundation for resolving the AE GRN. Developmental Dynamics, 2011. © 2010 Wiley‐Liss, Inc.
Identification and expression patterns of members of the protease‐activated receptor (par) gene family during zebrafish development
Authors: Xu Hui , Echemendia Nicholas , Chen Songhai , Lin Fang 
Published: December 2010

AbstractProtease‐activated receptors (PARs) play critical roles in hemostasis in vertebrates including zebrafish. However, the zebrafish gene classification appears to be complex, and the expression patterns ofpargenes are not established. Based on analyses of genomic organization, phylogenetics, protein primary structure, and protein internalization, we report the identification of four zebrafish PARs:par1,par2a,par2b, andpar3. This classification differs from one reported previously. We also show that these genes have distinct spatiotemporal expression profiles in embryos and larvae, withpar1,par2a, andpar2bexpressed maternally and ubiquitously during gastrula stages and their expression patterns refined at later stages, andpar3expressed only in 3‐day‐old larvae. Notably, the expression patterns of zebrafishpar1andpar2bresemble those of their mammalian counterparts, suggesting that receptor function is conserved among vertebrates. This conservation is supported by our findings that Par1 and Par2b are internalized following exposure to thrombin and trypsin, respectively. Developmental Dynamics, 2011. © 2010 Wiley‐Liss, Inc.
FilaminB is required for the directed localization of cell–cell adhesion molecules in embryonic epithelial development
Authors: Wakamatsu Yoshio , Sakai Daisuke , Suzuki Takashi , Osumi Noriko 
Published: December 2010

AbstractFilamin proteins cross‐link F‐actin and form a scaffold for numerous signal transduction systems. In this study, we show that filaminB is apically enriched in avian embryonic epithelium, and colocalizes with cell adhesion molecules and circumferential F‐actin. FilaminB knockdown in the neural tube and somites decreases the accumulation of N‐cadherin and ZO‐1 protein at cell junctions, and promotes disruption of these tissues and the presence of neuronal aggregates within the lumen of the neural tube. This phenotype resembles that of human congenital condition, periventricular heterotopia (PH). FilaminB knockdown in MDCK cells suggests that filaminB is required for the apical accumulation of adhesion molecules in the junctional complex and subsequent epithelium formation. We further suggest that the reduction of structural integrity of the neural epithelium caused by the loss of Filamin function may also result in formation of the neuronal nodules found in PH patients. Developmental Dynamics, 2011. © 2010 Wiley‐Liss, Inc.
A chemical enterocolitis model in zebrafish larvae that is dependent on microbiota and responsive to pharmacological agents
Authors: Oehlers Stefan H. , Flores Maria Vega , Okuda Kazuhide S. , Hall Chris J. , Crosier Kathryn E. , Crosier Philip S. 
Published: December 2010

AbstractInflammatory bowel disease (IBD) results from dysfunctional interactions between the intestinal immune system and microbiota, influenced by host genetic susceptibility. Because a key feature of the pathology is intestinal epithelial damage, potential disease factors have been traditionally analyzed within the background of chemical colitis models in mice. The zebrafish has greatly complemented the mouse for modeling aspects of disease processes, with an advantage for high content drug screens. Larval zebrafish exposed to the haptenizing agent trinitrobenzene sulfonic acid (TNBS) displayed impaired intestinal homeostasis and inflammation reminiscent of human IBD. There was a marked induction of pro‐inflammatory cytokines, the degradative enzyme mmp9 and leukocytosis. Enterocolitis was dependent on microbiota and Toll‐like receptor signaling, that can be ameliorated by antibiotic and anti‐inflammatory drug treatments. This system will be useful to rapidly interrogate in vivo the biological significance of the IBD candidate genes so far identified and to carry out pharmacological modifier screens. Developmental Dynamics, 2011. © 2010 Wiley‐Liss, Inc.
Embryonic development of the emu, Dromaius novaehollandiae
Authors: Nagai Hiroki , Mak Siu‐Shan , Weng Wei , Nakaya Yukiko , Ladher Raj , Sheng Guojun 
Published: December 2010

AbstractThe chick, Gallus gallus, is the traditional model in avian developmental studies. Data on other bird species are scarce. Here, we present a comparative study of the embryonic development of the chick and the emu Dromaius novaehollandiae, a member of Paleognathae, which also includes the ostrich, rhea, tinamou, kiwi, and cassowary. Emu embryos ranging from Hamburger and Hamilton (HH) equivalent stages 1 to 43 were collected and their gross morphology analyzed. Its early development was studied in detail with time‐lapse imaging and molecular techniques. Emu embryos in general take 2–3 times longer incubation time to reach equivalent chicken stages, requiring 1 day for HH2, 2.5 days for HH4, 7 days for limb bud initiation, 23 days for feather germ appearance, and approximately 50–56 days for hatching. Chordin gene expression is similar in emu and chick embryos, and emu Brachyury is not expressed until HH3. Circulation is established at approximately the 27‐ to 30‐somite stage. Forelimb buds are formed and patterned initially, but their growth is severely retarded. The size difference between an emu and a chick embryo only becomes apparent after limb bud formation. Overall, emu and chick embryogenesis proceeds through similar stages, but developmental heterochrony between these two species is widely observed. Developmental Dynamics, 2011. © 2010 Wiley‐Liss, Inc.
Beyond the Closed Suture in Apert Syndrome Mouse Models: Evidence of Primary Effects of FGFR2 Signaling on Facial Shape at Birth
Authors: Martínez‐Abadías Neus , Percival Christopher , Aldridge Kristina , Hill Cheryl A. , Ryan Timothy , Sirivunnabood Satama , Wang Yingli , Jabs Ethylin Wang , Richtsmeier Joan T. 
Published: December 2010

AbstractSuperimposed 3D visualization of the skull and head of mutant and non‐mutant littermates of the FGFR2 P253R mouse model at birth (P0). Lateral views of skeletal bone reconstructed from μCT isosurfaces are displayed. Skin surfaces are visualized from volume renderings; red (top left): Fgfr2+/+ non‐mutant littermate of the P253R model; and green (bottom right): Fgfr2+/P253R mutant littermate. From Martínez‐Abadías et al., Developmental Dynamics 239:3058–3071, 2010.