bluuebunny/crossref_metadata_2025 huggingface dataset:
Transcriptional regulation of claudin‐18 via specific protein kinase C signaling pathways and modification of DNA methylation in human pancreatic cancer cells
Authors: Ito Tatsuya , Kojima Takashi , Yamaguchi Hiroshi , Kyuno Daisuke , Kimura Yasutoshi , Imamura Masafumi , Takasawa Akira , Murata Masaki , Tanaka Satoshi , Hirata Koichi , Sawada Norimasa
Published: March 2011

Since claudin‐18 (Cldn18) is overexpressed in precursor lesion PanIN and pancreatic duct carcinoma, it serves as a diagnostic marker and a target of immunotherapy. The stomach isoform of Cldn18, Cldn18a2 is regulated via a PKC/MAPK/AP‐1‐dependent pathway in PKC activator 12‐O‐tetradecanoylphorbol 13‐acetate (TPA)‐stimulated gastric cancer cells. However, little is known about how Cldn18 is regulated, not only in pancreatic duct carcinoma but also in normal human pancreatic duct epithelial cells (HPDE cells). In the present study, four pancreatic cancer cell lines, HPAF‐II, HPAC, PANC‐1 and BXPC3, and hTERT‐HPDE cells in which the hTERT gene was introduced into HPDE cells in primary culture, were treated with TPA. In all human pancreatic cancer cell lines and hTERT‐HPDE cells, Cldn18 mRNA indicated as Cldn18a2 was markedly induced by TPA and in well‐ or moderately differentiated human pancreatic cancer cells HPAF‐II and HPAC and hTERT‐HPDE cells, the protein was also strongly increased. The upregulation of Cldn18 by TPA in human pancreatic cancer cell lines was prevented by inhibitors of PKCδ, PKCε, and PKCα, whereas the upregulation of Cldn18 by TPA in hTERT‐HPDE cells was prevented by inhibitors of PKCδ, PKCθ, and PKCα. Furthermore, a CpG island was identified within the coding sequence of the Cldn18 gene and treatment with the demethylating agent 5‐azadeoxycytidine enhanced upregulation of Cldn18 by TPA in HPAF‐II and HPAC, but not hTERT‐HPDE cells. Our findings suggest that in human pancreatic cancer cells, Cldn18 is primarily regulated at the transcriptional level via specific PKC signaling pathways and modified by DNA methylation. J. Cell. Biochem. 112: 1761–1772, 2011. © 2011 Wiley‐Liss, Inc.
MicroRNA 21 regulates the proliferation of human adipose tissue‐derived mesenchymal stem cells and high‐fat diet‐induced obesity alters microRNA 21 expression in white adipose tissues
Authors: Kim Yeon Jeong , Hwang Soo Hyun , Cho Hyun Hwa , Shin Keun Koo , Bae Yong Chan , Jung Jin Sup
Published: March 2011

A better understanding of the molecular mechanisms that govern human adipose tissue‐derived mesenchymal stem cells (hASCs) differentiation could provide new insights into a number of diseases including obesity. Our previous study demonstrated that microRNA‐21 (miR‐21) controls the adipogenic differentiation of hASCs. In this study, we determined the expression of miR‐21 in white adipose tissues in a high‐fat diet (HFD)‐induced obesity mouse model to examine the relationship between miR‐21 and obesity and the effect of miR‐21 on hASCs proliferation. Our study showed biphasic changes of miR‐21 expression and a correlation between miR‐21 level and adipocyte number in the epididymal fat of HFD mice. Over‐expression of miR‐21 decreased cell proliferation, whereas inhibiting miR‐21 with 2′‐O‐methyl‐antisense RNA increased it. Over‐expression of miR‐21 decreased both protein and mRNA levels of STAT3, whereas inhibiting miR‐21 with 2′‐O‐methyl‐antisense RNA increased these levels. The activity of a luciferase construct containing the miR‐21 target site from the STAT3 3′UTR was lower in LV‐miR21‐infected hASCs than in LV‐miLacZ infected cells. RNA interference‐mediated down‐regulation of STAT3 decreased cell proliferation without affecting adipogenic differentiation. These findings provide the evidence of the correlation between miR‐21 level and adipocyte number in the white adipose tissue of HFD‐induced obese mice, which provides new insights into the mechanisms of obesity. J. Cell. Physiol. 227: 183–193, 2012. © 2011 Wiley Periodicals, Inc.
β‐blockers as endocrine disruptors: the potential effects of human β‐blockers on aquatic organisms
Authors: Massarsky Andrey , Trudeau Vance L. , Moon Thomas W.
Published: March 2011

β‐Adrenergic blockers or β‐blockers have been used therapeutically to treat human hypertension since the late 1960s. The global market value and prescription rates of β‐blockers keep rising substantially each year, and over the past decade the number of prescriptions has doubled. The widespread use of β‐blockers has resulted in their appearance in the aquatic environment originating primarily from sewage effluents. The objective of this review is to analyze the literature as a means to determine the endocrine‐disrupting potential of β‐blockers in aquatic organisms. The mammalian adrenergic system is compared with the adrenergic system of fish and the homologous octopaminergic system in aquatic invertebrates, in particular mollusks. The structure and functions of these systems are linked to the molecular similarities between adrenoceptors and the octopaminergic/tyraminergic receptors, the various catecholamine molecules (epinephrine, norepinephrine, octopamine, and tyramine), and the processes controlled. Knowledge of these similarities as well as the effects of β‐blockers, mainly in humans, is then used to create a broad picture of the endocrine‐disrupting potential of β‐blockers, particularly during the stress response. The main conclusion is that β‐blockers have endocrine‐disrupting effects. J. Exp. Zool. 315:251–265, 2011. © 2011 Wiley‐Liss, Inc.
Maximal K3's and Hamiltonicity of 4‐connected claw‐free graphs
Authors: Fujisawa Jun , Ota Katsuhiro
Published: March 2011

Let cl(G) denote Ryjáček's closure of a claw‐free graph G. In this article, we prove the following result. Let G be a 4‐connected claw‐free graph. Assume that G[NG(T)] is cyclically 3‐connected if T is a maximal K3 in G which is also maximal in cl(G). Then G is hamiltonian. This result is a common generalization of Kaiser et al.'s theorem [J Graph Theory 48(4) (2005), 267–276] and Pfender's theorem [J Graph Theory 49(4) (2005), 262–272]. © 2011 Wiley Periodicals, Inc. J Graph Theory
An intramolecular N‐arylation approach to 3‐functionalized 4,9‐dihydropyrrolo[2,1‐b]quinazolines
Authors: Suthiwangcharoen Nisaraporn , Pochini Steven M. , Sweat Daniel P. , Stephens Chad E.
Published: March 2011

A series of 4,9‐dihydropyrrolo[2,1‐b]quinazolines containing electron withdrawing groups at the 3‐position have been prepared by the palladium‐catalyzed intramolecular N‐arylation of some 2‐aminopyrroles having a 2‐bromobenzyl group at the N‐1 position. Important for success of the reaction is the use of X‐phos, a biphenyl mono‐phosphine ligand, instead of xantphos, a more standard diphosphine ligand, and the use of t‐BuOH as reaction solvent. J. Heterocyclic Chem., (2011).
A solvent‐free protocol for one pot conversion of Baylis Hillman acetates to pyridopyrimidinones
Authors: Sreevani R. , Manjula A. , Rao B. Vittal
Published: March 2011

A facile one pot transformation of Baylis Hillman acetates to pyrido[1,2‐a]pyrimidin‐2‐ones by reaction with 2‐amino pyridine in a total solvent‐free protocol is illustrated. The 3‐substituted‐2H‐pyrido[1,2‐a]pyrimidin‐2‐ones are obtained in pure form without involving any purification technique or solvent. J. Heterocyclic Chem., (2011).
Polycyclic N‐heterocyclic compounds. Part 66: Synthesis of N‐[2‐([1,2,4]oxadiazol‐5‐yl)cyclopenten‐1‐yl]formamide oximes and their evaluation as inhibitors of platelet aggregation
Authors: Okuda Kensuke , Zhang Ying‐Xue , Ohtomo Hiromi , Hirota Takashi , Sasaki Kenji
Published: March 2011

N‐[2‐([1,2,4]Oxadiazol‐5‐yl)cyclopenten‐1‐yl]formamide oximes were synthesized by fusion of (6,7‐dihydro‐5H‐cyclopenta[1,2‐d]pyrimidin‐4‐yl)amidines and/or their amide oximes with hydroxylamine hydrochloride through a subsequent rearrangement reaction. Assay of the products for anti‐platelet aggregation activity revealed that certain of them showed promising inhibitory effect on arachidonic acid‐induced platelet aggregation. J. Heterocyclic Chem., (2011).
Long‐chain omega‐3 oils: Current and future supplies, food and feed applications, and stability
Authors: Wijesundera Chakra , Kitessa Soressa , Abeywardena Mahinda , Bignell Will , Nichols Peter D.
Published: March 2011

Increasing recognition of the health benefits of omega‐3 long‐chain (⪈C20) polyunsaturated fatty acids (omega‐3 LC‐PUFA or LC omega‐3 oils) continues. But new sources are needed, with recent developments with novel land plants showing promise. The value of existing and future sources LC omega‐3 oils occurs through aquaculture, livestock and other feeding. There is also a need toenhance the stability of oils containing LC omega‐3 oils. Challenges include increasing DHA levels in land plants, increasing oxidative stability in food products and product labeling. Consumers have difficulty recognizing and differentiating long‐chain and shorter‐chain (SC, C18) omega‐3 PUFA, both of which are referred to as “omega‐3” fatty acids.
The Maillard reaction and lipid oxidation
Authors: Zamora Rosario , Hidalgo Francisco J.
Published: March 2011

The Maillard reaction and lipid oxidation are probably the two most important chemical reactions occurring in foods during processing and storage. However, these pathways are not independent and each of them influences the development of the other. Furthermore, the carbonyl compounds produced in the lipid oxidation pathway will compete with carbohydrate‐derived carbonyls for amino compounds to produce carbonyl‐amine reaction products with either beneficial or harmful properties. These reactions are the final step of the oxidation pathway when lipid oxidation occurs in the presence of amino compounds.
Models mecanique pour les fibres de polyethylene lineaire basse densite d'apres la variation du module d'elasticite avec l'etirage
Authors: Rossignol J. M. , Séguéla R. , Rietsch F.
Published: March 2011

A mechanical model which accounts for the specific properties of linear low density polyethylene fibers is presented. This model is built on the classical High Modulus Takayanagy model which has been modified to interrupt the crystal continuity. It introduces two analogical parameters which are determined by thermal analysis and theoretical treatment of the stress strain curves of the fibers. The values of these parameters and their change with draw ratio are consistent with the increase of elastic modulus.
Etude de la reaction de condensation de systeme epoxyde‐amine par resonance magnetique nucleaire ‐ synthese de modeles epoxy‐amine
Authors: Francillette J. , Hoarau P. A. , Madec P. J.
Published: March 2011

This work is an approach to the analysis, by nuclear magnetic resonance of carbon 13, of epoxy‐aminated reticulates in the case of aliphatic aminated hardeners: butylamine, ethylene‐diamine, diethylenetriamine, triethylenetetramine. In order to characterize the various species formed at each stage of the reaction, and for various types of resin/hardener stoechiometry, the DGEBA (diglycidyl ether of bisphenol A)/polyamine couple has been modeled by characterizing the structures generated during the reactions of phenylglycidylether (PGE) with two aliphatic amines: n‐butylamine (BA) and ethylenediamine (EDA). This study deals with the characterization of non‐catalysed systems only (or at least systems without added catalyst).
Formulation d'un element fini adapte a la resolution des problemes de poutres stratifiees ou sandwiches
Authors: Sirot Bernard , Khelidj Abdelhafid
Published: March 2011

Among the numerical methods, there is the “finite element method” which is particularly adapted for the solution of the problems of the mechanics of continuous media.

The presence of an interface in the case of anisotropic materials (stratified, sandwiches, etc .) is due to a disorder like delamination. Therefore, the modelling of this type of materials needs the formulation of an element susceptible to take into account this singularity.

For solving this problem the formulation of a triangular element, having four degrees of freedom per node is needed, which permits at the interface the continuity of displacement, normal stress and shear stress. This element belongs to the Reissner element (assuring the continuity of stresses and displacements), but it is modified by an elimination method to keep only the degrees of freedom translating the continuity at the interface.

The work of Aivaz‐Zadeh and Verchery is based on the developed element. A comparison of the results is presented.
Novel mutations in SPG11 cause hereditary spastic paraplegia associated with early‐onset levodopa‐responsive Parkinsonism
Authors: Guidubaldi Arianna , Piano Carla , Santorelli Filippo M. , Silvestri Gabriella , Petracca Martina , Tessa Alessandra , Bentivoglio Anna Rita
Published: March 2011

Background: Autosomal recessive hereditary spastic paraplegia with thin corpus callosum is a neurodegenerative disorder characterized by spastic paraparesis, cognitive impairment, and peripheral neuropathy. The neuroradiologic hallmarks are thin corpus callosum and periventricular white matter changes. Mutations in the SPG11 gene have been identified to be a major cause of autosomal recessive hereditary spastic paraplegia with thin corpus callosum and recently also proven to be responsible for juvenile parkinsonism associated with spastic paraplegia.

Methods: We describe one Italian autosomal recessive hereditary spastic paraplegia with thin corpus callosum patient who unusually presented at onset, 16 years, with parkinsonism‐like features, responsive to dopaminergic therapy. Then the clinical picture evolved and became more complex. A brain magnetic resonance imaging scan showed thin corpus callosum and hyperintense T2‐weighted lesions in periventricular regions, and the 123I‐ioflupane single‐photon emission coupled tomography was abnormal.

Results: Genetic analysis detected two novel mutations, a c.3664insT variant in compound heterozygosity with a c.6331insG mutation, in SPG11.

Discussion: This case confirms the high genetic and clinical heterogeneity associated with SPG11 mutations. It also offers further evidence that parkinsonism may initiate autosomal recessive hereditary spastic paraplegia with thin corpus callosum and that parkinsonian symptoms can have variable dopaminergic response in these patients. © 2011 Movement Disorder Society
Modulation of gait coordination by subthalamic stimulation improves freezing of gait
Authors: Fasano Alfonso , Herzog Jan , Seifert Elena , Stolze Henning , Falk Daniela , Reese René , Volkmann Jens , Deuschl Günther
Published: March 2011

The effect of subthalamic deep brain stimulation on gait coordination and freezing of gait in patients with Parkinson's disease is incompletely understood. The purpose of this study was to investigate the extent to which modulation of symmetry and coordination between legs by subthalamic deep brain stimulation alters the frequency and duration of freezing of gait in patients with Parkinson's disease. We recruited 13 post‐subthalamic deep brain stimulation patients with Parkinson's disease with off freezing of gait and evaluated them in the following 4 conditions: subthalamic deep brain stimulation on (ON) and stimulation off (OFF), 50% reduction of stimulation voltage for the leg with shorter step length (worse side reduction) and for the leg with longer step length (better side reduction). Gait analysis was performed on a treadmill and recorded by an optoelectronic analysis system. We measured frequency and duration of freezing of gait episodes. Bilateral coordination of gait was assessed by the Phase Coordination Index, quantifying the ability to generate antiphase stepping. From the OFF to the ON state, freezing of gait improved in frequency (2.0 ± 0.4 to 1.4 ± 0.5 episodes) and duration (12.2 ± 2.6 to 2.6 ± 0.8 seconds; P = .005). Compared with the ON state, only better side reduction further reduced freezing of gait frequency (0.2 ± 0.2) and duration of episodes (0.2 ± 0.2 seconds; P = .03); worse side reduction did not change frequency (1.3 ± 0.4) but increased freezing of gait duration (5.2 ± 2.1 seconds). The better side reduction–associated improvements were accompanied by normalization of gait coordination, as measured by phase coordination index (16.5% ± 6.0%), which was significantly lower than in the other 3 conditions. Reduction of stimulation voltage in the side contralateral to the leg with longer step length improves frequency and duration of freezing of gait through normalization of gait symmetry and coordination in subthalamic deep brain stimulation patients with Parkinson's disease. This identifies poor leg coordination as a risk factor for causing freezing of gait. © 2011 Movement Disorder Society
Movement disorders in spinocerebellar ataxias
Authors: van Gaalen Judith , Giunti Paola , van de Warrenburg Bart P.
Published: March 2011

Autosomal dominant spinocerebellar ataxias (SCAs) can present with a large variety of noncerebellar symptoms, including movement disorders. In fact, movement disorders are frequent in many of the various SCA subtypes, and they can be the presenting, dominant, or even isolated disease feature. When combined with cerebellar ataxia, the occurrence of a specific movement disorder can provide a clue toward the underlying genotype. There are reasons to believe that for some coexisting movement disorders, the cerebellar pathology itself is the culprit, for example, in the case of cortical myoclonus and perhaps dystonia. However, movement disorders in SCAs are more likely related to extracerebellar pathology, and imaging and neuropathological data indeed show involvement of other parts of the motor system (substantia nigra, striatum, pallidum, motor cortex) in some SCA subtypes. When confronted with a patient with an isolated movement disorder, that is, without ataxia, there is currently no reason to routinely screen for SCA gene mutations, the only exceptions being SCA2 in autosomal dominant parkinsonism (particularly in Asian patients) and SCA17 in the case of a Huntington's disease–like presentation without an HTT mutation. © 2011 Movement Disorder Society
Examination of DNA methyltransferase expression in cloned embryos reveals an essential role for Dnmt1 in bovine development
Authors: Golding Michael C. , Williamson Gayle L. , Stroud Todd K. , Westhusin Mark E. , Long Charles R.
Published: March 2011

In studies of somatic cell nuclear transfer (SCNT), the ability of factors within the oocyte to epigenetically reprogram transferred nuclei is essential for embryonic development of the clone to proceed. However, irregular patterns of X‐chromosome inactivation, abnormal expression of imprinted genes, and genomic DNA hypermethylation are frequently observed in reconstructed embryos, suggesting abnormalities in this process. To better understand the epigenetic events underlying SCNT reprogramming, we sought to determine if the abnormal DNA methylation levels observed in cloned embryos result from a failure of the oocyte to properly reprogram transcription versus differential biochemical regulation of the DNA methyltransferase family of enzymes (DNMTs) between embryonic and somatic nuclei. To address this question, we conducted real‐time quantitation of Dnmt transcripts in bovine preimplantation embryos generated though in vitro fertilization (IVF), parthenogentic activation, and SCNT. By the 8‐cell stage, transcripts encoding Dnmt1 become significantly down‐regulated in cloned embryos, likely in response to the state of genomic hypermethylation, while the de novo methyltransferases maintain an expression pattern indistinguishable from their IVF and parthenote counterparts. Depletion of embryonic/maternal Dnmt1 transcripts within IVF embryos using short‐interfering RNAs, while able to lower genomic DNA methylation levels, resulted in developmental arrest at the 8/16‐cell stage. In contrast, SCNT embryos derived from a stable, Dnmt1‐depleted donor cell line develop to blastocyst stage, but failed to carry to term. Our results indicate an essential role for Dnmt1 during bovine preimplantation development, and suggest proper transcriptional reprogramming of this gene family in SCNT embryos. Mol. Reprod. Dev. 78:306–317, 2011. © 2011 Wiley‐Liss, Inc.
Quantitative T*2‐mapping based on multi‐slice multiple gradient echo flash imaging: Retrospective correction for subject motion effects
Authors: Magerkurth Joerg , Volz Steffen , Wagner Marlies , Jurcoane Alina , Anti Sandra , Seiler Alexander , Hattingen Elke , Deichmann Ralf
Published: March 2011

Numerous clinical and research applications for quantitative mapping of the effective transverse relaxation time T*2 have been described. Subject motion can severely deteriorate the quality and accuracy of results. A correction method for T*2 maps acquired with multi‐slice multiple gradient echo FLASH imaging is presented, based on acquisition repetition with reduced spatial resolution (and consequently reduced acquisition time) and weighted averaging of both data sets, choosing weighting factors individually for each k‐space line to reduce the influence of motion. In detail, the procedure is based on the fact that motion artifacts reduce the correlation between acquired and exponentially fitted data. A target data set is constructed in image space, choosing the data yielding best correlation from the two acquired data sets. The k‐space representation of the target is subsequently approximated as linear combination of original raw data, yielding the required weighting factors. As this method only requires a single acquisition repetition with reduced spatial resolution, it can be employed on any clinical system offering a suitable sequence with export of modulus and phase images. Experimental results show that the method works well for sparse motion, but fails for strong motion affecting the same k‐space lines in both acquisitions. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
19F‐lanthanide complexes with increased sensitivity for 19F‐MRI: Optimization of the MR acquisition
Authors: Chalmers Kirsten H. , Kenwright Alan M. , Parker David , Blamire Andrew M.
Published: March 2011

Fluorine‐19 magnetic resonance methods offer advantages for molecular or cellular imaging in vivo due to the absence of radioactivity, lack of naturally occurring background signal, and the ability to easily combine measurements with anatomical MRI. Previous studies have shown that 19F‐MRI sensitivity is limited to millimolar concentrations by slow longitudinal relaxation. In this study, a new class of macrocyclic fluorinated lanthanide complexes is investigated where relaxation rates are significantly shortened by proximity of the fluorine group to a paramagnetic lanthanide ion located within the same molecule. Longitudinal and transverse relaxation rates are field dependent and in the range 50–150 s−1 and 70–200 s−1, respectively, at 7 T. Relaxation rates in these complexes are a function of the molecular structure and are independent of concentration at biologically relevant levels, so can be used as criteria to optimize imaging acquisition. Phantom experiments at 7 T indicate a lower limit for detection by imaging of 20 μM. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Excess post‐exercise oxygen consumption is not associated with mechanomyographic amplitude after incremental cycle ergometry in the quadriceps femoris muscles
Authors: Malek Moh H. , Coburn Jared W. , Housh Terry J. , Rana Sharon
Published: March 2011

Introduction: The purpose of this study was to understand the relationship between the mechanical activities of the three superficial quadriceps muscles and excess post‐exercise oxygen consumption (EPOC) after incremental cycle ergometer exercise. Methods: Twelve healthy male volunteers had mechanomyographic (MMG) and electromyographic (EMG) activity of the superficial quadriceps muscles recorded 30 minutes before incremental cycle ergometry and 60 minutes after the exercise work bout. Results: The results indicate significant time‐constant values for EPOC and MMG amplitude for the three superficial quadriceps muscles during the 60‐minute post‐exercise recovery period. For EMG amplitude no decay patterns were found for the three muscles. In addition, there were no mean differences between the MMG values for the three muscles that were significantly different from EPOC. Conclusions: These results suggest that EPOC after exercise could not be exclusively attributed to elevated activity of the working muscles. Muscle Nerve 44: 432–438, 2011
Therapeutics development in myotonic dystrophy type 1
Authors: Foff Erin Pennock , Mahadevan Mani S.
Published: March 2011

Myotonic dystrophy (DM1), the most common adult muscular dystrophy, is a multisystem, autosomal dominant genetic disorder caused by an expanded CTG repeat that leads to nuclear retention of a mutant RNA and subsequent RNA toxicity. Significant insights into the molecular mechanisms of RNA toxicity have led to the previously unforeseen possibility that treating DM1 is a viable prospect. In this review, we briefly present the clinical picture in DM1, and describe how the research in understanding the pathogenesis of RNA toxicity in DM1 has led to targeted approaches to therapeutic development at various steps in the pathogenesis of the disease. We discuss the promise and current limitations of each with an emphasis on RNA‐based therapeutics and small molecules. We conclude with a discussion of the unmet need for clinical tools and outcome measures that are essential prerequisites to proceed in evaluating these potential therapies in clinical trials. Muscle Nerve, 2011
A distributed memory parallel multibody Contact Dynamics code
Authors: Koziara T. , Bićanić N.
Published: March 2011

Solfec is a computational code aimed at simulation of constrained multibody systems on distributed memory parallel computers. It implements an instance of the Contact Dynamics (CD) method by Moreau and Jean, hence the constraints are handled implicitly. One of the main goals of the software is to provide a user friendly platform for testing formulations and solution methods for the (dynamic) frictional contact problem. It is also meant to serve as a development platform for other aspects of time‐stepping methods (e.g. contact detection, time integration, kinematic models). The purpose of this communication is to outline the algorithmic ideas behind Solfec, with an emphasis on the Gauss–Seidel constraints solver, a classical element of CD, efficiently implemented on a distributed memory model. The remaining topics include a dynamic domain decomposition balancing the computational load of the overall algorithm, and an accuracy measure for the frictional contact constraints. Solfec is an open‐source software and can be downloaded from http://code.google.com/p/solfec. Copyright © 2011 John Wiley & Sons, Ltd.
Methyl donor deficiency induces cardiomyopathy through altered methylation/acetylation of PGC‐1α by PRMT1 and SIRT1
Authors: Garcia Maira Moreno , Guéant‐Rodriguez Rosa‐Maria , Pooya Shabnam , Brachet Patrick , Alberto Jean‐Marc , Jeannesson Elise , Maskali Fathia , Gueguen Naig , Marie Pierre‐Yves , Lacolley Patrick , Herrmann Markus , Juillière Yves , Malthiery Yves , Guéant Jean‐Louis
Published: March 2011

Cardiomyopathies occur by mechanisms that involve inherited and acquired metabolic disorders. Both folate and vitamin B12 deficiencies are associated with left ventricular dysfunction, but mechanisms that underlie these associations are not known. However, folate and vitamin B12 are methyl donors needed for the synthesis of S‐adenosylmethionine, the substrate required for the activation by methylation of regulators of energy metabolism. We investigated the consequences of a diet lacking methyl donors in the myocardium of weaning rats from dams subjected to deficiency during gestation and lactation. Positron emission tomography (PET), microscope and metabolic examinations evidenced a myocardium hypertrophy, with cardiomyocyte enlargement, disturbed mitochondrial alignment, lipid droplets, decreased respiratory activity of complexes I and II and decreased S‐adenosylmethionine:S‐adenosylhomocysteine ratio. The increased concentrations of triglycerides and acylcarnitines were consistent with a deficit in fatty acid oxidation. These changes were explained by imbalanced acetylation/methylation of PGC‐1α, through decreased expression of SIRT1 and PRMT1 and decreased S‐adenosylmethionine:S‐adenosylhomocysteine ratio, and by decreased expression of PPARα and ERRα. The main changes of the myocardium proteomic study were observed for proteins regulated by PGC‐1α, PPARs and ERRα. These proteins, namely trifunctional enzyme subunit α‐complex, short chain acylCoA dehydrogenase, acylCoA thioesterase 2, fatty acid binding protein‐3, NADH dehydrogenase (ubiquinone) flavoprotein 2, NADH dehydrogenase (ubiquinone) 1α‐subunit 10 and Hspd1 protein, are involved in fatty acid oxidation and mitochondrial respiration. In conclusion, the methyl donor deficiency produces detrimental effects on fatty acid oxidation and energy metabolism of myocardium through imbalanced methylation/acetylation of PGC‐1α and decreased expression of PPARα and ERRα. These data are of pathogenetic relevance to perinatal cardiomyopathies. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Carboplatin‐based chemotherapy and surgery: A cost effective treatment strategy for malignant extracranial germ cell tumours in the developing world
Authors: Hendricks Marc , Davidson Alan , Pillay Komala , Desai Farieda , Millar Alastair
Published: March 2011

Nineteen children with malignant extracranial germ cell tumours (MEGCT), were treated at our institution with a combination of carboplatin‐based chemotherapy and surgery from 1992 to 2008. Seventeen are long term survivors. Chemotherapy was administered on an outpatient basis and required no monitoring of GFR or auditory function. There were no deaths from toxicity or infection. Blood product use was low. Carboplatin‐based therapy achieved excellent results in our patient population and constitutes more than a US $1,800 saving per patient compared to regimens containing cisplatin. This has application in resource limited settings. Pediatr Blood Cancer 2011;57:172–174. © 2011 Wiley‐Liss, Inc.
Influence of constituents on thermal properties of polymethacrylate derivatives–clay materials
Authors: Benlikaya Ruhan , Alkan Mahir
Published: March 2011

In this study, the solution‐mixing method was used to prepare polymethacrylate derivatives' (PaMAs) nanocomposites with kaolinite. It was observed that the resultant materials could include exfoliated, intercalated, and undispersed kaolinite depending on their XRD patterns. TEM micrographs also revealed that platy and tube structures of kaolinite and their stacked form would disperse in the PaMAs. Therefore, they were called PaMAs–kaolinite materials with mixed morphology. The effects caused by different types of PaMA, solvent, and clay (sepiolite and kaolinite) on the thermal properties of these materials were examined. When the thermal stability of the materials was compared on the basis of the functional groups in the PaMAs, it was seen that the materials of the linear PaMAs with kaolinite usually had better thermal stability than that of the ring PaMAs and also seen that the thermal stability of Kao‐PaMAs increased from PMMA to poly(ethyl methacrylate) (PEMA) and poly(butyl methacrylate) for linear PaMAs. The solvent type affected the thermal stability and the glass transition temperature of the PaMAs. It was found that THF is the most suitable solvent for increasing thermal stability of the PaMAs in the presence of kaolinite; however, it is difficult to say the same about their Tg temperatures. In addition, the thermal stabilities of PEMA and poly(2‐hydroxylethyl methacrylate) were higher in the presence of kaolinite in comparison with sepiolite. The results obtained in this study were explained by the utilization of the relationships among their solubility parameters and of the interactions among the PaMAs, clays, the modifier (octadecylamine) and solvents. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Morphology, resistivity, and thermal behavior of EVOH/carbon black and EVOH/graphite composites prepared by simple saponification method
Authors: Lee Eun‐Ju , Yoon Jin‐San , Park Eun‐Soo
Published: March 2011

Poly(ethylene‐co‐vinyl alcohol) (EVOH)/carbon black (CB) and EVOH/graphite (GP) electro‐conductive composites were prepared by saponification of poly(ethylene‐co‐vinyl acetate) (EVA)/CB and EVA/GP composites in ethanol/KOH solution. The electrical resistivity change and positive temperature coefficient (PTC) behavior of these composites were investigated. The volume resistivity of EVA/CB and EVA/GP composites was decreased with saponification time. It can be observed that EVA/CB10 and EVA/GP05 composites showed a significant reduction in resistivity after saponification for 1 h. With the increase in saponification time, PTC peak temperature of both composites was shifted at a higher temperature. Tensile properties, morphology, and thermal behavior of the prepared composites have been also evaluated using universal test machine, scanning electron microscopy, and differential scanning calorimetry, respectively. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Poly(ascorbyl acrylate)s: Synthesis and evaluation of their redox polymerization ability in the presence of hydrogen peroxide
Authors: Zhuang Dequan , Nie Jun , Yang Jing
Published: March 2011

In this work, a strategy for chemical synthesis of ascorbic acid functionalized polyacrylates (PAAA) was accomplished in a two‐step process, first a reversible addition fragmentation chain‐transfer (RAFT) polymerization on a benzyl‐protected ascorbyl acrylate monomer, followed by a deprotection (debenzylation) reaction. The polymers were characterized by 1H NMR, 13C NMR and gel permeation chromatograph. The polymerization ability of redox pair including PAAA and H2O2 were conducted through the measurement of 2‐hydroxyethyl acrylate (HEA) conversion against time via real‐time FT‐NIR. It was found that PAAA in the presence of H2O2, independent on itself chain length, exhibited much faster polymerization than small molecule ascorbic acid (smAA) as reductant at identical condition. Interestingly, when the concentration of ascorbate repeating unit was over some critical value, the polymerization kinetics of HEA could be tunable by simply adjusting the initial molar ratio of reductant to oxidant and environmental pH. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Influence of the family cluster effect on psychosocial variables in families undergoing BRCA1/2 genetic testing for cancer susceptibility
Authors: Lapointe Julie , Abdous Belkacem , Camden Stéphanie , Bouchard Karine , Goldgar David , Simard Jacques , Dorval Michel
Published: March 2011

Objective: This study evaluated the influence of the family cluster effect on behavioral and psychological variables among individuals undergoing BRCA1/2 genetic testing for cancer susceptibility.

Methods: French‐Canadian women (n = 552) and men (n = 104) from 140 different families undergoing BRCA1/2 testing between years 1998 and 2004 completed a self‐administered questionnaire on a wide range of behavioral and psychological variables. The impact of the family cluster effect on 29 variables was assessed using the intraclass correlation coefficient (ICC) as computed from multilevel random‐effect models.

Results: ICC values were statistically significant for 22 of the 29 variables. Overall, the mean ICC value was 0.10. The ICC values for knowledge about hereditary breast and ovarian cancer and frequency of alcohol consumption were 0.25. The ICC value for the Impact of Event Scale, which is a commonly used measure of cancer‐specific distress, was 0.14.

Conclusions: Our results suggest that the family cluster effect influences the majority of behavioral and psychosocial variables. When studying psychosocial aspects of genetic testing for cancer susceptibility, the family cluster effect should be routinely accounted for when determining sample size and statistical methods. Copyright © 2011 John Wiley & Sons, Ltd.
Droplet evaporation and spread on waxy and hairy leaves associated with type and concentration of adjuvants
Authors: Xu Linyun , Zhu Heping , Ozkan H Erdal , Bagley William E , Krause Charles R
Published: March 2011

BACKGROUND: Adjuvants can improve pesticide application efficiency and effectiveness. However, quantifications of the adjuvant‐amended pesticide droplet actions on foliage, which could affect application efficiencies, are largely unknown.

RESULTS: Droplet evaporation rates and spread on waxy or hairy leaves varied greatly with the adjuvant types tested. On waxy leaves, the wetted areas of droplets containing crop oil concentrate (COC) were significantly smaller than those containing modified seed oil (MSO), non‐ionic surfactant (NIS) or oil surfactant blend (OSB), whereas the evaporation rates of COC‐amended droplets were significantly higher. On hairy leaves, COC‐amended droplets remained on top of the hairs without wetting the epidermis. When the relative concentration was 1.50, the wetted area of droplets with NIS was 9.2 times lower than that with MSO and 6.1 times lower than that with OSB. The wetted area increased as the adjuvant concentration increased. MSO‐ or OSB‐amended droplets spread extensively on the hairy leaf surface until they were completely dried.

CONCLUSION: These results demonstrated that the proper concentration of MSO, NIS or OSB in spray mixtures improved the homogeneity of spray coverage on both waxy and hairy leaf surfaces and could reduce pesticide use. Published 2011 by John Wiley & Sons, Ltd.
RNA interference in Nilaparvata lugens (Homoptera: Delphacidae) based on dsRNA ingestion
Authors: Li Jie , Chen Qiuhong , Lin Yongjun , Jiang Tingru , Wu Gang , Hua Hongxia
Published: March 2011

BACKGROUND: An efficient and convenient RNA interference (RNAi) technique involving double‐stranded RNA (dsRNA) ingestion is useful for gene function studies of non‐model insects.

RESULTS: Three dsRNAs targeting different sites within a gene encoding vacuolar ATP synthase subunit E (V‐ATPase‐E, 21E01) were synthesised for RNAi in Nilaparvata lugens. dsRNA was found to be stable in 0.1 g mL−1 sucrose solution, but unstable in artificial fodder. Therefore, dsRNAs were orally delivered into N. lugens in 0.1 g mL−1 sucrose solution. RNAi was induced by all three of the dsRNAs at 0.05 µg µL−1 in N. lugens. Time dynamics analysis of gene silencing indicated that significant suppression of the target gene began as early as 2 days after ingestion of ds2‐21E01 and ds3‐21E01. However, significant repressive effects were recorded up to 10 days after exposure to ds1‐21E01. The maximum reduction in target gene mRNA was observed after 10 days of treatment, with suppression ratios induced by ds1‐21E01, ds2‐21E01 and ds3‐21E01 of 41, 55 and 48% respectively.

CONCLUSION: An efficient and convenient RNAi technique involving dsRNA ingestion has been successfully developed for N. lugens. This will be a useful tool for further functional genomic investigation in this organism. Copyright © 2011 Society of Chemical Industry
Agronomic performance of F1, F2 and F3 hybrids between weedy rice and transgenic glufosinate‐resistant rice
Authors: Song Xiaoling , Wang Zhou , Qiang Sheng
Published: March 2011

BACKGROUND: Studies of hybrid fitness, of which agronomic performance may be an indicator, can help in evaluating the potential for introgression of a transgene from a transgenic crop to wild relatives. The objective of this study was to assess the agronomic performance of reciprocal hybrids between two transgenic glufosinate‐resistant rice lines, Y0003 and 99‐t, and two weedy rice accessions, WR1 and WR2, in the greenhouse.

RESULTS: F1 hybrids displayed heterosis in height, flag leaf area and number of spikelets per panicle. The agronomic performance of F1 between WR1 and Y0003 was not affected by crossing direction. The tiller and panicle numbers of F1 individuals were higher than their F2 counterparts. However, these traits did not change significantly from the F2 to the F3 generation or in hybrids with weedy rice as maternal or paternal plants. For all hybrids, the in vitro germination rates of fresh pollen were similar and significantly lower than those of their parents, seed sets were similar to or of lower value than those of weedy rice parents and seed shattering characteristics were partially suppressed, but the survival of hybrids over winter in the field was similar to that of weedy rice parents. All F1, F2 and F3 hybrids had similar composite agronomic performance to weedy rice parents.

CONCLUSION: There was no significant decrease in the composite agronomic performance of any of the hybrids compared with weedy rice. This implies that gene flow from transgenic cultivated rice to weedy rice could occur under natural conditions. Copyright © 2011 Society of Chemical Industry
Controllability of switching networks of multi‐agent systems
Authors: Liu Bo , Chu Tianguang , Wang Long , Zuo Zhiqiang , Chen Guanrong , Su Housheng
Published: March 2011

This paper addresses the controllability of a switching network of multi‐agent systems with a leader obeying nearest‐neighbor communication rules. The leader is a particular agent acting as an external input to control other member agents. Some computationally efficient sufficient conditions for such multi‐agent systems to be controllable are derived. The results show that a multi‐agent system can be controllable even if each of its subsystem is not controllable, by appropriately selecting one of the agents as the leader and suitably designing the neighbor‐interaction rules via a switching topology. The fixed topology case is analyzed and new controllability conditions and formula of inputs for the desired formation of the network are presented. The controllability of a switching network of multi‐agent systems in the presence of communication delay is also investigated. Examples with numerical simulations are given to illustrate the theoretical results. Copyright © 2011 John Wiley & Sons, Ltd.
Mechanically Stacked 1‐nm‐Thick Carbon Nanosheets: Ultrathin Layered Materials with Tunable Optical, Chemical, and Electrical Properties
Authors: Nottbohm Christoph T. , Turchanin Andrey , Beyer André , Stosch Rainer , Gölzhäuser Armin
Published: March 2011

Carbon nanosheets are mechanically stable, free‐standing two‐dimensional materials with a thickness of ≈1 nm and well defined physical and chemical properties. They are made by radiation‐induced cross‐linking of aromatic self‐assembled monolayers. Herein, a route is presented to the scalable fabrication of multilayer nanosheets with tunable electrical, optical, and chemical properties on insulating substrates. Stacks of up to five nanosheets with sizes of ≈1 cm2 on oxidized silicon are studied. Their optical characteristics are investigated by visual inspection, optical microscopy, UV–vis reflection spectroscopy, and model calculations. Their chemical composition is studied by X‐ray photoelectron spectroscopy. The multilayer samples are then annealed in an ultrahigh vacuum at various temperatures up to 1100 K. A subsequent investigation by Raman, X‐ray photoelectron, and UV–vis reflection spectroscopy, as well as by electrical four‐point probe measurements, demonstrates that the layered nanosheets transform into nanocrystalline graphene. This structural and chemical transformation is accompanied by changes in the optical properties and electrical conductivity and opens up a new path for the fabrication of ultrathin functional conductive coatings.
JMP statistical discovery software
Authors: Jones Bradley , Sall John
Published: March 2011

JMP is a statistical software environment that enables scientists, engineers, and business analysts to make discoveries through data exploration. One powerful method for beginning the process of discovery employs statistically designed experiments. A well‐designed experiment ensures that the resulting data have large information content. We support this method with custom design, an innovative approach to the statistical design of experiments. But whether your results come from designed experiments or from an observational study, we provide analytical tools that put graphs up front. JMP's graphical user interface (GUI) makes these plots interactive and dynamically linked to each other and to the data. Moreover, in the design of JMP's user interface the priority was to make a smooth and natural workflow for data analysis. Notice how the data exploration flows in the following case study that investigates the relationship between life expectancy and health‐care spending for 166 countries. WIREs Comp Stat 2011 3 188–194 DOI: 10.1002/wics.162

This article is categorized under:

Software for Computational Statistics > Software/Statistical Software
Monte Carlo simulation code for confocal 3D micro‐beam X‐ray fluorescence analysis of stratified materials
Authors: Czyzycki Mateusz , Wegrzynek Dariusz , Wrobel Pawel , Lankosz Marek
Published: March 2011

Stratified materials are of great importance for many branches of modern industry, e.g. electronics or optics and for biomedical applications. Examination of chemical composition of individual layers and determination of their thickness helps to get information on their properties and function. A confocal 3D micro X‐ray fluorescence (3D µXRF) spectroscopy is an analytical method giving the possibility to investigate 3D distribution of chemical elements in a sample with spatial resolution in the micrometer regime in a non‐destructive way. Thin foils of Ti, Cu and Au, a bulk sample of Cu and a three‐layered sandwich sample, made of two thin Fe/Ni alloy foils, separated by polypropylene, were used as test samples. A Monte Carlo (MC) simulation code for the determination of elemental concentrations and thickness of individual layers in stratified materials with the use of confocal 3D µXRF spectroscopy was developed. The X‐ray intensity profiles versus the depth below surface, obtained from 3D µXRF experiments, MC simulation and an analytical approach were compared. Correlation coefficients between experimental versus simulated, and experimental versus analytical model X‐ray profiles were calculated. The correlation coefficients were comparable for both methods and exceeded 99%. The experimental X‐ray intensity profiles were deconvoluted with iterative MC simulation and by using analytical expression. The MC method produced slightly more accurate elemental concentrations and thickness of successive layers as compared to the results of the analytical approach. This MC code is a robust tool for simulation of scanning confocal 3D µXRF experiments on stratified materials and for quantitative interpretation of experimental results. Copyright © 2011 John Wiley & Sons, Ltd.
A novel portable XRF spectrometer with range of detection extended to low‐Z elements
Authors: Migliori A. , Bonanni P. , Carraresi L. , Grassi N. , Mandò P. A.
Published: March 2011

X‐ray fluorescence (XRF) analysis is one of the most widely used techniques for material analysis in the field of cultural heritage, thanks to its non‐destructive and multi‐elemental character and also to the possibility of using portable instrumentations. The need of compact systems for in situ analyses results generally in a worse, more limited performance: the detection of low‐Z elements is the most affected aspect. In this article, we present a custom‐realised portable XRF spectrometer developed in Florence at the LABEC laboratory of Istituto Nazionale di Fisica Nucleare (INFN), in collaboration with ICVBC of Consiglio Nazionale delle Ricerche (CNR). The system features a high efficiency for a wide range of elements, even at low Z (down to sodium), thanks to the use of two tubes with different anodes and to the presence of a continuous helium flow in front of the tubes and the detector, in order to enhance transmission of both primary and characteristic X‐rays. After a detailed description of the spectrometer, the experimental characterisation of its performance is presented: efficiency curves obtained from the analysis of thin standards are reported, together with minimum detection limits for some elements in a thick target of medium‐low density matrix. Examples of measurements, which demonstrate the capability and effectiveness of this spectrometer, are also reported. Copyright © 2011 John Wiley & Sons, Ltd.