bluuebunny/crossref_metadata_2025_split huggingface dataset:
NAD(P)H oxidase participates in the palmitate‐induced superoxide production and insulin secretion by rat pancreatic islets
Authors: Graciano Maria Fernanda R. , Santos Laila R.B. , Curi Rui , Carpinelli Angelo R. 
Published: September 2010

AbstractNicotinamide adenine dinucleotide phosphate [NAD(P)H] oxidase complex has been shown to be involved in the process of glucose‐stimulated insulin secretion (GSIS). In this study, we examined the effect of palmitic acid on superoxide production and insulin secretion by rat pancreatic islets and the mechanism involved. Rat pancreatic islets were incubated during 1 h with 1 mM palmitate, 1% fatty acid free‐albumin, 5.6 or 10 mM glucose and in the presence of inhibitors of NAD(P)H oxidase (DPI—diphenyleneiodonium), PKC (calphostin C) and carnitine palmitoyl transferase‐I (CPT‐I) (etomoxir). Superoxide content was determined by hydroethidine assays. Palmitate increased superoxide production in the presence of 5.6 and 10 mM glucose. This effect was dependent on activation of PKC and NAD(P)H oxidase. Palmitic acid oxidation was demonstrated to contribute for the fatty acid induction of superoxide production in the presence of 5.6 mM glucose. In fact, palmitate caused p47PHOXtranslocation to plasma membrane, as shown by immunohistochemistry. Exposure to palmitate for 1 h up‐regulated the protein content of p47PHOXand the mRNA levels of p22PHOX, gp91PHOX, p47PHOX, proinsulin and the G protein‐coupled receptor 40 (GPR40). Fatty acid stimulation of insulin secretion in the presence of high glucose concentration was reduced by inhibition of NAD(P)H oxidase activity. In conclusion, NAD(P)H oxidase is an important source of superoxide in pancreatic islets and the activity of NAD(P)H oxidase is involved in the control of insulin secretion by palmitate. J. Cell. Physiol. 226: 1110–1117, 2011. © 2010 Wiley‐Liss, Inc.
Monitoring of herbal mixtures potentially containing synthetic cannabinoids as psychoactive compounds
Authors: Dresen Sebastian , Ferreirós Nerea , Pütz Michael , Westphal Folker , Zimmermann Ralf , Auwärter Volker 
Published: September 2010

AbstractHerbal mixtures like ‘Spice’ with potentially bioactive ingredients were available in many European countries since 2004 and are still widely used as a substitute for cannabis, although merchandized as ‘herbal incense’. After gaining a high degree of popularity in 2008, big quantities of these drugs were sold. In December 2008, synthetic cannabinoids were identified in the mixtures which were not declared as ingredients: the C8homolog of the non‐classical cannabinoid CP‐47,497 (CP‐47,497‐C8) and a cannabimimetic aminoalkylindole called JWH‐018. In February 2009, a few weeks after the German legislation put these compounds and further pharmacologically active homologs of CP‐47,497 under control, another cannabinoid appeared in ‘incense’ products: the aminoalkylindole JWH‐073.In this paper, the results of monitoring of commercially available ‘incense’ products from June 2008 to September 2009 are presented. In this period of time, more than 140 samples of herbal mixtures were analyzed for bioactive ingredients and synthetic cannabimimetic substances in particular. The results show that the composition of many products changed repeatedly over time as a reaction to prohibition and prosecution of resellers. Therefore neither the reseller nor the consumer of these mixtures can predict the actual content of the ‘incense’ products. As long as there is no possibility of generic definitions in the controlled substances legislation, further designer cannabinoids will appear on the market as soon as the next legal step has been taken. This is affirmed by the recent identification of the aminoalkylindoles JWH‐250 and JWH‐398. As further cannabinoids can be expected to occur in the near future, a continuous monitoring of these herbal mixtures is required.The identification of the synthetic opioidO‐desmethyltramadol in a herbal mixture declared to contain ‘kratom’ proves that the concept of selling apparently natural products spiked with potentially dangerous synthetic chemicals/pharmaceuticals is a continuing trend on the market of ‘legal highs’. Copyright © 2010 John Wiley & Sons, Ltd.
A pitfall of using 2‐[(2E)‐3‐(4‐tert‐butylphenyl)‐2‐methylprop‐2‐enylidene]malononitrile as a matrix in MALDI TOF MS: chemical adduction of matrix to analyte amino groups
Authors: Lou Xianwen , de Waal Bas F. M. , van Dongen Joost L. J. , Vekemans Jef A. J. M. , Meijer E. W. 
Published: September 2010

Abstract2‐[(2E)‐3‐(4‐tert‐Butylphenyl)‐2‐methylprop‐2‐enylidene]malononitrile (DCTB) has been considered as an excellent matrix for matrix‐assisted laser desorption/ionization (MALDI) of many types of synthetic compounds. However, it might provide troublesome results for compounds containing aliphatic primary or secondary amino groups. For these compounds, strong extra ion peaks with a mass difference of 184.1 Da were usually observed, which might falsely indicate the presence of some unknown impurities that were not detected by other matrices. On the basis of the possible mechanisms proposed, these extra ions are the products of nucleophilic reactions between analyte amino groups and DCTB molecules or radical cations. In these reactions, an amino group replaces the dicyanomethylene group of DCTB forming a matrix adduct via a CN‐bond. An aliphatic primary amine could react easily with DCTB and the reaction could start once they are mixed in a MALDI solution. For an aliphatic secondary amine, on the other hand, the reaction most likely occurs in the gas phase. Protonation of amino groups by adding acid seems to be a useful way to stop DCTB adduction for compounds with one single amino group, but not for compounds with multiple amino groups. Unlike aliphatic primary or secondary amines, aliphatic tertiary amines and aromatic amines do not yield DCTB adducts. This is because tertiary amines do not have the required transferrable H‐(N) atom to form an extra CN‐bond, while aromatic amines are not sufficiently nucleophilic to attack DCTB. In view of the possible matrix adduction, care should be taken in MALDI time‐of‐flight mass spectrometry (TOF MS) when DCTB is used as the matrix for compounds containing amino group(s). Copyright © 2010 John Wiley & Sons, Ltd.
How factors secreted from astrocytes impact myelin repair
Authors: Moore Craig S. , Abdullah Shahana L. , Brown Andrew , Arulpragasam Amanda , Crocker Stephen J. 
Published: September 2010

AbstractOver a century ago, hypertrophy of astrocytes was noted as a pathology of multiple sclerosis (MS) and was hypothesized to play an important role in this disease, yet the contribution of astrocytes has been largely underemphasized in the pathophysiology of CNS demyelination. Astrocytes perform many homeostatic functions within the developing and adult CNS, including enhancing formation and maintenance of the blood–brain barrier, moderating neuronal connections through the tripartite synapse, and perhaps evenoffering intercellular communication independently of neurons. Although there is a significant body of literature characterizing different types of MS lesions, the inflammatory demyelination in an active MS lesion is accompanied by the presence of macrophages, lymphocytes, and large reactive astrocytes. The astrocyte has long been viewed as a cell that promotes inflammation and demyelination, while also forming the glial scar, thus hindering remyelination and axon growth. Renewed interest in the astrocyte has been brought about by recent studies demonstrating that astrocytes can also function as cellular mediators of CNS myelination by promoting oligodendrocyte progenitor migration, proliferation, and differentiation. Thus, refining our knowledge of astrocytic functions in the regulation of CNS myelination may help us to better understand why remyelination fails in MS. © 2010 Wiley‐Liss, Inc.
Reduced expression and activation of voltage‐gated sodium channels contributes to blunted baroreflex sensitivity in heart failure rats
Authors: Tu Huiyin , Zhang Libin , Tran Thai P. , Muelleman Robert L. , Li Yu‐Long 
Published: September 2010

AbstractVoltage‐gated sodium (Nav) channels are responsible for initiation and propagation of action potential in the neurons. To explore the mechanisms of chronic heart failure (CHF)‐induced baroreflex dysfunction, we measured the expression and current density of Nav channel subunits (Nav1.7, Nav1.8, and Nav1.9) in the aortic baroreceptor neurons and investigated the role of Nav channels in aortic baroreceptor neuron excitability and baroreflex sensitivity in sham and CHF rats. CHF was induced by left coronary artery ligation. The development of CHF (6–8 weeks after the coronary ligation) was confirmed by hemodynamic and morphological characteristics. Immunofluorescent data indicated that Nav1.7 was expressed in A‐type (myelinated) and C‐type (unmyelinated) nodose neurons, but Nav1.8 and Nav1.9 were expressed only in C‐type nodose neurons. Real‐time RT‐PCR and Western blot data showed that CHF reduced mRNA and protein expression levels of Nav channels in nodose neurons. In addition, using the whole‐cell patch‐clamp technique, we found that Nav current density and cell excitability of the aortic baroreceptor neurons were lower in CHF rats than that in sham rats. Aortic baroreflex sensitivity was blunted in anesthetized CHF rats, compared with that in sham rats. Furthermore, Nav channel activator (rATX II, 100 nM) significantly enhanced Nav current density and cell excitability of aortic baroreceptor neurons and improved aortic baroreflex sensitivity in CHF rats. These results suggest that reduced expression and activation of the Nav channels are involved in the attenuation of baroreceptor neuron excitability, which subsequently contributes to the impairment of baroreflex in CHF state. © 2010 Wiley‐Liss, Inc.
Simvastatin interferes with process outgrowth and branching of oligodendrocytes
Authors: Smolders Inge , Smets Ilse , Maier Olaf , vandeVen Martin , Steels Paul , Ameloot Marcel 
Published: September 2010

AbstractStatins have attracted interest as a treatment option for multiple sclerosis (MS) because of their pleiotropic antiinflammatory and immunomodulatory effects. However, contradictory results have been described when they are applied to oligodendrocytes (OLGs), the cell type predominantly affected in MS. In this study we focus on the in vitro effect of statins on process outgrowth in OLN‐93 cells, a well‐characterized OLG‐derived cell line, and primary cultures of neonatal rat OLGs. Application of the lipophilic simvastatin, as low as 0.1–1 μM, disturbs process formation of both cell types, leading to less ramified cells. We show that both protein isoprenylation and cholesterol synthesis are required for the normal differentiation of OLGs. It is further demonstrated that the expression of 2′,3′‐cyclic‐nucleotide‐3′ phosphodiesterase (CNP) and tubulin is lowered, concomitant with a reduction of membrane‐bound CNP as well as tubulin. Therefore, we propose that lack of isoprenylation of CNP could help to explain the altered morphological and biochemical differentiation state of treated OLGs. Moreover, expression of specific myelin markers, such as myelin basic protein, myelin‐associated glycoprotein, and myelin oligodendrocyte glycoprotein, was compromised after treatment. We conclude that simvastatin treatment has detrimental effects on OLG process outgrowth, the prior step in (re)myelination, thereby mortgaging long‐term healing of MS lesions. © 2010 Wiley‐Liss, Inc.
Glial cell line‐derived neurotrophic factor enhances in vitro differentiation of mid‐/hindbrain neural progenitor cells to dopaminergic‐like neurons
Authors: Young Amber , Assey Kristin S. , Sturkie Carla D. , West Franklin D. , Machacek David W. , Stice Steven L. 
Published: September 2010

AbstractParkinson's disease (PD) affects the motor system through the degeneration of the dopaminergic neurons of the substantia nigra. The use of human embryonic stem cell (hESC)‐derived human neural progenitor (hNP) cells provides a potential cell source for cell therapies and drug screens for future treatments. Glial cell line‐derived neurotrophic factor (GDNF) is a known dopaminergic neuroprotectant agent; however, its potential role in neural differentiation remains largely unknown. Addition of 25 ng/ml GDNF to hNP cell differentiation media, over a 21‐day period, induced a significantly (P < 0.05) greater portion of hNP cells to differentiate into dopaminergic neurons than non‐GDNF cultures, 50% compared with 2.9% of cells expressing tyrosine hydroxylase (TH), respectively. The hNP cells exposed to GDNF selectively expressed dopamine receptors 1, 4, and 5 and were evoked to release dopamine with KCl. This is the first report of GDNF and leukemia inhibitory factor enriching hESC‐derived hNP cells toward dopaminergic‐like neurons. © 2010 Wiley‐Liss, Inc.
Post‐Plasma Grafting of AEMA as a Versatile Tool to Biofunctionalise Polyesters for Tissue Engineering
Authors: Desmet Tim , Billiet T. , Berneel Elke , Cornelissen Ria , Schaubroeck David , Schacht Etienne , Dubruel Peter 
Published: September 2010

AbstractIn the last decade, substantial research in the field of post‐plasma grafting surface modification has focussed on the introduction of carboxylic acids on surfaces by grafting acrylic acid (AAc). In the present work, we report on an alternative approach for biomaterial surface functionalisation. Thin poly‐ε‐caprolactone (PCL) films were subjected to a dielectric barrier discharge Ar‐plasma followed by the grafting of 2‐aminoethyl methacrylate (AEMA) under UV‐irradiation. X‐ray photoelectron spectroscopy (XPS) confirmed the presence of nitrogen. The ninhydrin assay demonstrated, both quantitatively and qualitatively, the presence of free amines on the surface. Confocal fluorescence microscopy (CFM), atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to visualise the grafted surfaces, indicating the presence of pAEMA. Static contact angle (SCA) measurements indicated a permanent increase in hydrophilicity. Furthermore, the AEMA grafted surfaces were applied for comparing the physisorption and covalent immobilisation of gelatin. CFM demonstrated that only the covalent immobilisation lead to a complete coverage of the surface. Those gelatin‐coated surfaces obtained were further coated using fibronectin. Osteosarcoma cells demonstrated better cell‐adhesion and cell‐viability on the modified surfaces, compared to the pure PCL films.
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Calculation of Grafting and Property Characterization in Polyurethane‐Acrylic Hybrid Materials Prepared by Emulsion Process
Authors: Jiang Xubao , Kong Xiang‐Zheng , Zhu Xiaoli , Zhang Zhao , Zhang Zhi‐Guo 
Published: September 2010

AbstractPolyurethane‐acrylics (PU‐AC) hybrid latexes were prepared using isophorone diisocyanate and polypropylene oxides as main monomers for the PU component, butyl acrylate and methyl methacrylate as AC monomers, and hydroxyethyl acrylate (HEA) as coupling agent to build up chemical bonds between PU prepolymers and AC polymers (PAC). A simple method to determine the PU grafted to PAC chains at one end and at both ends was established, which showed that PU grafted to PAC at both terminals was obviously increasing with HEA, and soon became predominant over that grafted by one end when the HEA/NCO molar ratio reached 0.67. With HEA/NCO < 1, PU grafting, particle size of the hybrid latex and film tensile strength increased with the HEA amount; while with HEA/NCO > 1, these properties remained relatively stable.
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BMO and Injectivity of Space Quasiregular Mappings
Authors: Martio Olli , Ryazanov Vladimir , Vuorinen Matti 
Published: September 2010

AbstractIt is shown that if the dilatation tensor G f of a space quasi regular mapping f belongs to the space VMO (vanishing mean oscillation), then f is a local homeomorphism. The same is true If the BMO‐norm of G f is small or if Gf is only close to the VMO space in the BMO‐norm.
The Essential Spectrum of a System of Singular Ordinary Differential Operators of Mixed Order. Part I: The General Problem and an Almost Regular Case
Authors: Faierman Melvin , Mennicken Reinhard , Möller Manfred 
Published: September 2010

AbstractA system of ordinary differential operators of mixed order on an interval (0,τ0), ro0 > 0, is considered, where the coefficients may be singular at 0. A special case has been dealt with by Kako where the essential spectrum of an operator associated with a linearized magnetohydrodynamic equation was explicitly calculated. In the present first part of the paper we study an almost regular special case which can be treated by the operator theoretical methods developed by Atkinson, Langer, Mennicken and Shkalikov. A closed linear operator is associated with the given system of differential operators and its essential spectrum is explicitly characterized in terms of the coefficients of these differential operators.
Real‐Time IR Study of Ultra‐Thin Film Photopolymerization of Liquid Porphyrin Monomer
Authors: Lintinen Kalle , Granqvist Niko , Efimov Alexander , Lemmetyinen Helge 
Published: September 2010

AbstractBy using an advanced polarization modulation infrared reflection adsorption spectroscopy (PM‐IRRAS) device it is possible to study the photopolymerization of an ultrathin layer of a porphyrin monomer in real time. The method can be compared with the indirect UV/Vis method previously introduced by our group. With PM‐IRRAS it is possible to analyze polymerization kinetics of photopolymerization at various temperatures to determine the activation energy of the reaction.
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Revisiting Chain Transfer to Polymer and Branching in Controlled Radical Polymerization of Butyl Acrylate
Authors: Reyes Yuri , Asua José M. 
Published: September 2010

AbstractAcrylic monomers undergo chain transfer to polymer during polymerization leading to branched and even gelled polymers. It has been experimentally demonstrated that the extent of branching is higher for conventional free radical polymerization than for controlled radical polymerization (ATRP, RAFT, NMP) and this has been qualitatively explained in terms of the differences in the concentrations of highly reactive short‐chain radicals between controlled and conventional radical polymerizations. Contrary to this explanation, in this work, it is quantitatively demonstrated that the short transient lifetime of the radicals, i.e., the time between activation and deactivation of the radical in controlled radical polymerization, is the cause for the low level of branching in these polymerizations.
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Modeling Controlled/Living Radical Polymerization Kinetics: Bulk and Miniemulsion
Authors: Tobita Hidetaka 
Published: September 2010

AbstractA first‐principle model for the controlled/living radical polymerization (CLRP) is discussed. The polymerization rate of CLRP is conveniently represented by a simple relationship, Rp ∝ [Intermediate]/[Trapping Agent], which highlights the important characteristics of various types of CLRPs. In stable free radical polymerization and atom‐transfer radical polymerization, the relationship, [Trap] ≪ [Interm] holds, and the polymerization rate is controlled by [Trap]. When the polymerization is conducted in nanosized particles, even a single trapping agent in a particle may lead to a larger [Trap] than for bulk polymerization. This single‐molecule‐concentration (SMC) effect theory leads to determine the particle diameter, Dp,SMC below which Rp starts to decrease significantly compared with the corresponding bulk polymerization, and $R_{{\rm p}} \,{\propto} \,D_{{\rm p}}^{3} $ for Dp < Dp,SMC. For the particle sizes somewhat larger than Dp,SMC, the statistical variation in the number of trapping agents can make Rp larger. A simple equation to estimate the Dp,Fluct‐value, below which the acceleration due to the fluctuation effect is predicted to occur, is presented. In conjunction with the SMC effect, an acceleration window, in which Rp is larger than for bulk polymerization, may be observed for Dp,SMC < Dp < Dp,Fluct. On the other hand, many reversible‐addition‐fragmentation chain transfer polymerizations conform to the condition [Interm] ≪ [Trap], and Rp is controlled by [Interm]. If [Interm] in a particle under the zero‐one condition is larger than for bulk polymerization, Rp can be increased significantly by reducing the particle size due to the zero‐one intermediate molecule (ZIM) effect. The ZIM effect theory leads to determine the particle diameter, Dp,ZIM below which Rp increases significantly compared with the bulk polymerization, and $R_{{\rm p}} \,{\propto} \,D_{{\rm p}}^{{-} 3} $ for Dp < Dp,ZIM.
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Compatibility of superparamagnetic iron oxide nanoparticle labeling for 1H MRI cell tracking with 31P MRS for bioenergetic measurements
Authors: Zhang Zhuoli , Hancock Brynne , Leen Stephanie , Ramaswamy Sharan , Sollott Steven J. , Boheler Kenneth R. , Juhaszova Magdalena , Lakatta Edward G. , Spencer Richard G. , Fishbein Kenneth W. 
Published: September 2010

AbstractLabeling of cells with superparamagnetic iron oxide nanoparticles permits cell tracking by 1H MRI while 31P MRS allows non‐invasive evaluation of cellular bioenergetics. We evaluated the compatibility of these two techniques by obtaining 31P NMR spectra of iron‐labeled and unlabeled immobilized C2C12 myoblast cells in vitro. Broadened but usable 31P spectra were obtained and peak area ratios of resonances corresponding to intracellular metabolites showed no significant differences between labeled and unlabeled cell populations. We conclude that 31P NMR spectra can be obtained from cells labeled with sufficient iron to permit visualization by 1H imaging protocols and that these spectra have sufficient quality to be used to assess metabolic status. This result introduces the possibility of using localized 31P MRS to evaluate the viability of iron‐labeled therapeutic cells as well as surrounding host tissue in vivo. Published in 2010 by John Wiley & Sons, Ltd.
Molecular orientation behavior of mesomorphic isotactic polypropylene under uniaxial and biaxial deformation
Authors: Yoshida Shingo , Ishii Kazuomi , Kawamura Takanobu , Nitta Koh‐Hei 
Published: September 2010

AbstractThe molecular orientation behavior of mesomorphic isotactic polypropylene films under biaxial extension was investigated at room temperature. The birefringence was measured not only for drawn films but also simultaneously with biaxial stresses. It was found that there exists a yield point at which the neck is initiated on the biaxial deformed films and necking occurred and propagated in only one stretching direction, resulting in mosaic structures consisting of necked blocks. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
Silane grafting and moisture crosslinking of polypropylene
Authors: Chaudhary Bharat Indu , Sengupta Saurav S. , Cogen Jeffrey M. , Curto Michael 
Published: September 2010

AbstractDifferent approaches for free‐radical initiated grafting of functional monomers to polypropylene (PP) have been investigated with a view to enabling crosslinking of the polymer upon subsequent exposure to moisture, resulting in gel contents as high as 50–60 wt%. The first approach involved grafting a co‐agent such as triallyl trimellitate (TATM) to the polymer using peroxide initiator to add carbon–carbon double bond functionality to the polymer, followed by peroxide‐initiated grafting of mercaptopropyltrimethoxysilane (MPTMS) to the PP‐TATM adduct. The second approach was the more traditional peroxide‐mediated grafting of vinyltrimethoxysilane (VTMS) to polypropylene, and was most effective at increasing melt state dynamic storage modulus. In the third approach, peroxide‐mediated grafting of VTMS was followed by peroxide‐initiated grafting of MPTMS. This process took advantage of the unsaturation created via chain scission in the first step to provide graft sites for the MPTMS in the second step. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers