bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial learning results in elevated agmatine levels in the rat brain
Authors: Liu Ping , Collie Nicola D. , Chary Sree , Jing Yu , Zhang Hu
Published: August 2008

Accumulating evidence suggests that agmatine, a metabolite of L‐arginine by arginine decarboxylase, is a novel neurotransmitter, and exogenous agmatine can modulate behavior functions including learning and memory. However, direct evidence of its involvement in learning and memory processes is currently lacking. This study measured agmatine levels in the hippocampus, parahippocampal region, cerebellum, and vestibular nucleus in rats that were trained to find a hidden escape platform in the water‐maze task, or forced to swim in the pool with no platform presented, or kept in the holding‐box, using liquid chromatography/mass spectrometry. Compared with the swimming only group and holding‐box group, agmatine levels were significantly increased in the CA1 and dentate gyrus subregions of the hippocampus, the entorhinal cortex and the vestibular nucleus in the water‐maze training group. These results, for the first time, demonstrate spatial learning‐induced region‐specific elevation in agmatine, and raise a novel issue of the involvement of agmatine in the processes of learning and memory. © 2008 Wiley‐Liss, Inc.
Modulating human connective tissue progenitor cell behavior on cellulose acetate scaffolds by surface microtextures
Authors: Kim Eun Jung , Boehm Cynthia A. , Fleischman Aaron J. , Muschler George F. , Kostov Yordan V. , Roy Shuvo
Published: August 2008

Soft lithography techniques are used to fabricate cellulose acetate (CA) scaffolds with surface microtextures to observe growth characteristics of the progeny of human marrow‐derived connective tissue progenitor cells (CTPs). Human CTPs were collected and cultured on CA scaffolds comprised postmicrotextures and smooth surfaces for up to 30 days. Cells on the smooth surfaces migrated without any preferred orientation for up to 30 days. On microtextures, cells tended to direct their processes toward posts and other cells on day 9. By day 30, cells on microtextures covered the surface with extracellular matrix. DNA quantification revealed approximately threefold more cells on microtextures than on the smooth surfaces. The alkaline phosphatase (AP) mRNA expression was slightly higher on smooth surfaces on day 9. However, by day 30, AP mRNA showed higher expression on microtextures. The mRNA expression of collagen type I was increased on microtextures by day 30, whereas smooth surfaces demonstrated similar expression. The osteocalcin mRNA expression was increased on postmicrotextures relative to smooth surfaces by day 30. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
A revisionist replicon model for higher eukaryotic genomes
Authors: Hamlin J.L. , Mesner L.D. , Lar O. , Torres R. , Chodaparambil S.V. , Wang L.
Published: August 2008

The replicon model devised to explain replication control in bacteria has served as the guiding paradigm in the search for origins of replication in the more complex genomes of eukaryotes. In Saccharomyces cerevisiae, this model has proved to be extremely useful, leading to the identification of specific genetic elements (replicators) and the interacting initiator proteins that activate them. However, replication control in organisms ranging from Schizosaccharomyces pombe to mammals is far more fluid: only a small number of origins seem to represent classic replicators, while the majority correspond to zones of inefficient, closely spaced start sites none of which are indispensable for origin activity. In addition, it is apparent that the epigenetic state of a given sequence largely determines its ability to be used as a replication initiation site. These conclusions were arrived at over a period of three decades, and required the development of several novel replicon mapping techniques, as well as new ways of examining the chromatin architecture of any sequence of interest. Recently, methods have been elaborated for isolating all of the active origins in the genomes of higher eukaryotes en masse. Microarray analyses and more recent high‐throughput sequencing technology will allow all the origins to be mapped onto the chromosomes of any organism whose genome has been sequenced. With the advent of whole‐genome studies on gene expression and chromatin composition, the field is now positioned to define both the genetic and epigenetic rules that govern origin activity. J. Cell. Biochem. 105: 321–329, 2008. © 2008 Wiley‐Liss, Inc.
Involvement of c‐Src tyrosine kinase in SHP‐1 phosphatase activation by Ang II AT2receptors in rat fetal tissues
Authors: Alvarez Sergio E. , Seguin Leonardo R. , Villarreal Rodrigo S. , Nahmias Clara , Ciuffo Gladys M.
Published: August 2008

Angiotensin II (Ang II) AT2receptors are abundantly expressed in rat fetal tissues where they probably contribute to development. In the present study we examine the effects of Ang II type 2 receptor stimulation on SHP‐1 activation. Ang II (10−7M) elicits a rapid and transient tyrosine phosphorylation of SHP‐1, maximal at 1 min, in a dose‐dependent form, blocked by the AT2antagonist, PD123319. SHP‐1 phosphorylation is followed in time by tyrosine dephosphorylation of different proteins, suggesting a sequence of events. Ang II induces association of SHP‐1 to AT2receptors as shown by co‐immunoprecipitation, Western blot and binding assays. SHP‐1 activity was determined in immunocomplexes obtained with either anti‐AT2or anti‐SHP‐1 antibodies, after Ang II stimulation (1 min), in correlation with the maximal level of SHP‐1 phosphorylation. Interestingly, following receptor stimulation (1 min) c‐Src was associated to AT2or SHP‐1 immunocomplexes. Preincubation with the c‐Src inhibitor PP2 inhibited SHP‐1 activation and c‐Src association, thus confirming the participation of c‐Src in this pathway. We demonstrated here for the first time the involvement of c‐Src in SHP‐1 activation via AT2receptors present in an ex vivo model expressing both receptor subtypes. In this model, AT2receptors are not constitutively associated to SHP‐1 and SHP‐1 is not constitutively activated. Thus, we clearly establish that SHP‐1 activation, mediated by the AT2subtype, involves c‐Src and precedes protein tyrosine dephosphorylation, in rat fetal membranes. J. Cell. Biochem. 105: 703–711, 2008. © 2008 Wiley‐Liss, Inc.
Differential transactivation by orphan nuclear receptor NOR1 and its fusion gene product EWS/NOR1: Possible involvement of poly(ADP‐ribose) polymerase I, PARP‐1
Authors: Ohkura Naganari , Nagamura Yuko , Tsukada Toshihiko
Published: August 2008

In extraskeletal myxoid chondrosarcoma, a chromosomal translocation creates a gene fusion between EWS and an orphan nuclear receptor, NOR1. The resulting fusion protein EWS/NOR1 has been believed to lead to malignant transformation by functioning as a transactivator for NOR1‐target genes. By comparing the gene expression profiles of NOR1‐ and EWS/NOR1‐overexpressing cells, we found that they largely shared up‐regulated genes, but no significant correlation was observed with respect to the transactivation levels of each gene. In addition, the proteins associated with NOR1 and EWS/NOR1 were mostly the same in these cells. The results suggest that these proteins differentially transactivate overlapping target genes through a similar transcriptional machinery. To clarify the mechanisms underlying the transcriptional divergence between NOR1 and EWS/NOR1, we searched for alternatively associated proteins, and identified poly(ADP‐ribose) polymerase I (PARP‐1) as an NOR1‐specific binding protein. Consistent with its binding properties, PARP‐1 acted as a transcriptional repressor of NOR1, but not EWS/NOR1, in a luciferase reporter assay employing PARP‐1(−/−) fibroblasts. Interestingly, suppressive activity of PARP‐1 was observed in a DNA response element‐specific manner, and in a subtype‐specific manner toward the NR4A family (Nur77, Nurr1, and NOR1), suggesting that PARP‐1 plays a role in the diversity of transcriptional regulation mediated by the NR4A family in normal cells. Altogether, our findings suggest that NOR1 and EWS/NOR1 regulate overlapping target genes differently by utilizing associated proteins, including PARP‐1; and that EWS/NOR1 may acquire oncogenic activities by avoiding (or gaining) transcription factor‐specific modulation by the associated proteins. J. Cell. Biochem. 105: 785–800, 2008. © 2008 Wiley‐Liss, Inc.
Strong difference families over arbitrary graphs
Authors: Buratti Marco , Gionfriddo Lucia
Published: August 2008

The concept of a strong difference family formally introduced in Buratti [J Combin Designs 7 (1999), 406–425] with the aim of getting group divisible designs with an automorphism group acting regularly on the points, is here extended for getting, more generally, sharply‐vertex‐transitive Γ‐decompositions of a complete multipartite graph for several kinds of graphs Γ. We show, for instance, that if Γ has e edges, then it is often possible to get a sharply‐vertex‐transitive Γ‐decomposition of Km × e for any integer m whose prime factors are not smaller than the chromatic number of Γ. This is proved to be true whenever Γ admits an α‐labeling and, also, when Γ is an odd cycle or the Petersen graph or the prism T5 or the wheel W6. We also show that sometimes strong difference families lead to regular Γ‐decompositions of a complete graph. We construct, for instance, a regular cube‐decomposition of K16m for any integer m whose prime factors are all congruent to 1 modulo 6. © 2008 Wiley Periodicals, Inc. J Combin Designs 16: 443–461, 2008
New insights on cellular distribution, microtubule interactions and post‐translational modifications of MS‐KIF18A
Authors: Zusev Margalit , Benayahu Dafna
Published: August 2008

The present study highlights on the biochemical and immunological analysis of MS‐KIF18A in pre‐osteogenic MBA‐15 cells. The protein distribution in various cellular compartments was demonstrated by imaging and Western blot (WB) analysis. MS‐KIF18A interactions with cytoskeletal proteins were confirmed for tubulin and actin. The complex between MS‐KIF18A and microtubules (MT) was demonstrated in cellular system for endogenous proteins and also between recombinant proteins in pull down and immunoprecipitation (IP) assays. Multiple assays including metabolic labeling, cell fractionation and IP with anti‐MS‐KIF18A antibody demonstrated an association with actin that was prominent in the cell cytoplasm. Sub‐cellular fractionation identified diverse forms of MS‐KIF18A in cytoplasm and membrane/nucleus compartments which are suggested to represent the result of post‐transcriptional modifications, such as phosphorylation and glycosylation. These modifications on MS‐KIF18A were analyzed by bioinformatics and immunological assays. Furthermore, we studied the role of ubiquitin–proteasome system in the MS‐KIF18A degradation. Taken together, the current study sheds light on MS‐KIF18A a MT‐dependent kinesin and adds insights on the post‐translational modifications that potentially control the protein cellular distribution and its co‐association with cytoskeletal proteins. J. Cell. Physiol. 217: 618–625, 2008. © 2008 Wiley‐Liss, Inc.
Evolving strategies for global gene expression analysis of cancer
Authors: Coe Bradley P. , Chari Raj , Lockwood William W. , Lam Wan L.
Published: August 2008

The advent of high throughput gene expression profiling, from microarrays to sequence based assays has yielded vast insight into the biology of tumors. New technologies are constantly being unveiled which promise to generate more accurate maps of tumor gene deregulation, and demand the development of new strategies in data analysis. This review details the challenges faced in profiling tumor transcriptomes, and highlights the emerging strategies to utilize global profiling approaches to advance our understanding of causal genetic and epigenetic events and their impact on gene expression and tumor phenotype and behavior, through high throughput profiling, and integration of multiple dimensions of genomic data. J. Cell. Physiol. 217: 590–597, 2008. © 2008 Wiley‐Liss, Inc.
Optimization of alkaline protease production from Shewanella oneidensis MR‐1 by response surface methodology
Authors: Anbu Periasamy , Annadurai Gurusamy , Lee Jiunn‐Fwu , Hur Byung‐Ki
Published: August 2008

BACKGROUND: The proteases are among the most important groups of enzymes. Therefore, it is important to produce inexpensive and optimized media for large‐scale commercial production. In the present work, three different Shewanella species were screened on skim milk agar medium for their ability to produce alkaline protease. The effects of different culture conditions were optimized for alkaline protease production by S. oneidensis MR‐1 using a Box–Behnken design combined with response surface methodology (RSM).

RESULTS: Highest yield (112.90 U mL−1) of protease production was obtained at pH 9.0, a temperature of 30 °C, glucose (12.5 g L−1), tryptone (12.5 g L−1) and an incubation period of 36 h. A second‐order polynomial regression model was used for analysis of the experiment. The experimental values were in good agreement with predicted values, with correlation coefficient 0.9996.

CONCLUSION: Carbon and nitrogen, pH, temperature and incubation period were chosen as the main factors to be used in an experimental design for optimization to produce low‐cost enzymes, potentially for use on an industrial scale. A 60% increase in enzyme activity was achieved in the optimized medium compared with the original medium. Copyright © 2008 Society of Chemical Industry
Removal of H2S and volatile organic sulfur compounds by silicone membrane extraction
Authors: Manconi I. , Lens P. N. L.
Published: August 2008

BACKGROUND: This study explores an alternative process for the abatement and/or desulfurization of H2S and volatile organic sulfur compounds (VOSC) containing waste streams, which employs a silicone‐based membrane to simultaneously remove H2S and VOSC. An extractive membrane reactor allows the selective withdrawal of VOSC and H2S simultaneously from the waste stream, while preventing direct contact between the waste stream and the absorbing solution and/or the biological treatment system. The influence of the sulfur compounds, membrane characteristics, extractant and pH was studied.

RESULTS: Sulfide and the VOCS studied, i.e. methanethiol (MT), ethanethiol (ET) and dimethylsulfide (DMS) were removed from the synthetic wastewater using a silicone rubber membrane. Methanethiol showed the highest (8.72 × 10−6 m s−1) overall mass transfer coefficient (kov) and sulfide the lowest kov value (1.23 × 10−6 m s−1). Adsorption of the VOCS into the silicone membrane reduced the overall mass transfer coefficient. The kov when using Fe(III)EDTA− as extractant (5.81 × 10−7 m s−1) for sulfide extraction was one order of magnitude lower than with anaerobic water (2.54 × 10−6 m s−1). On the other hand, the sulfide removal efficiency with Fe(III)EDTA− was higher (84%) compared with anaerobic water (60%) as extractant. An additional mass transfer resistance was formed by elemental sulfur which remained attached to the membrane surface.

CONCLUSIONS: Extraction of sulfide and VOCS from a synthetic wastewater solution through a silicone rubber membrane is a feasible process as alternative to the techniques developed to treat VOSC emissions. Optimizing the aqueous absorption liquid can increase the efficiency of extraction based processes. Copyright © 2008 Society of Chemical Industry
A kinetic study of the depolymerisation of poly(ethylene terephthalate) by phase transfer catalysed alkaline hydrolysis
Authors: López‐Fonseca R. , González‐Marcos M. P. , González‐Velasco J. R. , Gutiérrez‐Ortiz J. I.
Published: August 2008

BACKGROUND: Chemical or tertiary recycling of waste polymers including PET, poly(ethylene terephthalate), leads to the formation of raw starting monomers by different depolymerisation routes. This work was focused on the identification of the catalytic behaviour, if any, of a series of quaternary phosphonium and ammonium salts as phase transfer catalysts for the alkaline hydrolysis of PET, and on the determination of the kinetics of the phase transfer catalysed process.

RESULTS: Among the salts examined tributylhexadecylphosphonium bromide was found to be the most effective catalyst. The proposed kinetic model accounted for the uncatalysed and catalysed reactions and predicted a linear correlation for the reaction rate with the concentration of the quaternary salt. The notable increase in the phase transfer catalysed reaction rate was related mainly to the greater value of the pre‐exponential factor while the value of the activation energy was hardly modified by the presence of the quaternary phosphonium salt, thereby suggesting a similar mechanism for the alkaline hydrolysis with or without phase transfer catalyst.

CONCLUSIONS: The use of selected phosphonium quaternary salts exhibited a remarkably positive effect on the experimental conditions under which the depolymerisation of poly(ethylene terephthalate) by alkaline hydrolysis can be carried out, especially in terms of low operating temperature. Kinetic correlations provided a reliable mathematical reaction model for this recycling process, which is in agreement with the principles of sustainable development. Copyright © 2008 Society of Chemical Industry
Effect of dry‐salt processing on the textural properties and cell wall polysaccharides of cv. Thasos black olives
Authors: Cardoso Susana M , Mafra Isabel , Reis Ana , Georget Dominique MR , Smith Andrew C , Waldron Keith W , Coimbra Manuel A
Published: August 2008

BACKGROUND: Thasos is an olive variety cultivated mainly in Greece used to produce ‘naturally black dry‐salted olives’. This process consists in placing the olives in disposed layers with coarse sodium chloride. The loss of water and other solutes gradually debitters and wrinkles the fruits. In this study, the effect of dry‐salt processing on the texture and cell wall polysaccharide composition was investigated.

RESULTS: This type of processing affected primarily the mechanical properties of the olive flesh. In processed olives, this tissue was approximately 4.5 times stronger and also more deformable up to failure and stiffer than that from the raw olives. The dry‐salt processing had its strongest effect on pectic polysaccharides. This included the increment of solubilization of arabinose‐rich polymers in aqueous solutions, and thus their partial loss to the soak medium during dry‐salting. Contrarily, galacturonic acid‐rich polymers were further retained in the processed olives, probably by their stabilization within the cell walls by reduction of the electrostatic repulsion between the acidic groups of these polysaccharides due to sodium ions.

CONCLUSION: The texture improvement of olive flesh by dry‐salt processing seems to be correlated with the reorganization of the galacturonic acid‐rich pectic polysaccharides into the cell wall of the fruit. Copyright © 2008 Society of Chemical Industry
Review of factors that influence the abundance of ions produced in a tandem mass spectrometer and statistical methods for discovering these factors
Authors: Barton Sheila J. , Whittaker John C.
Published: August 2008

Proteomic technologies are important because they link genes, proteins and disease. The identification of proteins and peptides has been revolutionized in the last decade by the use of mass spectrometry. This method is highly sensitive and much faster than the chemical reactions used previously because it can fragment peptides in seconds rather than in hours or days. Proteins are digested with an enzyme, usually trypsin, and the resulting peptides are fragmented in a tandem mass spectrometer (MS/MS). The masses of the fragment ions formed in the MS/MS can be used to identify the sequence of amino acids in the peptides. However, a number of different factors have been found to influence the amount of the various types of fragment ion formed. In this article, we review these factors and their interrelation together with the statistical methods used to discover them. Information on the number of fragment ions formed is at present underused in peptide identification algorithms, and fully utilizing this information could improve current algorithms. © 2008 Wiley Periodicals, Inc., Mass Spec Rev 28:177–187, 2009
Enhancement of p53 expression in keratinocytes by the bioflavonoid apigenin is associated with RNA‐binding protein HuR
Authors: Tong Xin , Pelling Jill C.
Published: August 2008

We have reported previously that apigenin, a naturally occurring nonmutagenic flavonoid, increased wild‐type p53 protein expression in the mouse keratinocyte 308 cell line by a mechanism involving p53 protein stabilization. Here we further demonstrated that the increase in p53 protein level induced by apigenin treatment of 308 keratinoyctes was not the result of enhanced transcription, mRNA stabilization or cytoplasmic export of p53 mRNA. Instead, biosynthetic labeling showed that apigenin increased nascent p53 protein synthesis by enhancing p53 translation. The AU‐rich element (ARE) within the 3′‐untranslated region (UTR) of p53 mRNA was found to be responsible for apigenin's ability to increase p53 translation, as demonstrated in studies wherein the 3′‐UTR of p53 mRNA containing the ARE was fused downstream of a luciferase reporter gene. Furthermore, apigenin treatment increased the level of association of the RNA binding protein HuR with endogenous p53 mRNA. Apigenin treatment also augmented HuR translocation into the cytoplasm. Overexpression of HuR enhanced apigenin‐induced p53 protein expression in 308 keratinocytes, whereas siRNA‐mediated HuR reduction suppressed apigenin‐induced p53 protein expression and de novo translation of p53. Moreover, apigenin treatment of cells induced p16 protein expression, which in turn was correlated with cytoplasmic localization of HuR induced by apigenin. Overall, these findings indicate that, in addition to modulating p53 protein stability, one of the mechanisms by which apigenin induces p53 protein expression is enhancement of translation through the RNA binding protein HuR. © 2008 Wiley‐Liss, Inc.
Inhibition of non‐small cell lung cancer cell migration by grape seed proanthocyanidins is mediated through the inhibition of nitric oxide, guanylate cyclase, and ERK1/2
Authors: Punathil Thejass , Katiyar Santosh K.
Published: August 2008

Tumor cell migration is considered as a major event in the metastatic cascade. Here we examined the effect of grape seed proanthocyanidins (GSPs) on migration capacity and signaling mechanisms using nonsmall cell human lung cancer cells. Using in vitro migration assay, we found that treatment of A549 and H1299 cells with GSPs resulted in concentration‐dependent inhibition of migration of these cells. The migration capacity of cells was reduced in presence of NG‐nitro‐L‐arginine methyl ester (L‐NAME), an inhibitor of nitric oxide synthase. GSPs suppressed the elevated levels of endogenous NO/NOS in A549 and H1299 cells and blocked the migration promoting capacity ofL‐arginine. Treatment with guanylate cyclase (GC) inhibitor 1‐H‐[1,2,4]oxadiaxolo[4,3‐a]quinolalin‐1‐one (ODQ) reduced the migration of A549 cells whereas additional presence of 8‐bromoguanosine 3′5′‐cyclic monophosphate (8‐Br‐cGMP, cGMP analogue) restored the migration of these cells, suggesting a role for GC in migration of A549 cells. GSPs reduced the elevated levels of cGMP in cancer cells and also blocked the migration restoring activity of 8‐Br‐cGMP. The mitogen‐activated protein kinase kinase (MAPKK) inhibitor, UO126, inhibited the migration of A549 cells, indicating a role for MAPKK in the migration. Additionally, UO126 and ODQ inhibited the migration restoring effects ofL‐arginine inL‐NAME‐treated cells, suggesting the involvement of cGMP and MAPK pathways in NO‐mediated migration. GSPs inhibitedL‐arginine and 8‐Br‐cGMP‐induced activation of ERK1/2 in A549 cells. Together, these results indicate sequential inhibition of NO/NOS, GC, and MAPK pathways by GSPs in mediating the inhibitory signals for cell migration, an essential step in invasion and metastasis. © 2008 Wiley‐Liss, Inc.
Optimal control and design of a cold store using dynamic optimization
Authors: Lukasse Leo , Broeze Jan , van der Sluis Sietze
Published: August 2008

The design of controlled processes is a combined optimal control and design problem (OCDP). Literature on solving large OCDPs is rare. This paper presents an algorithm for solving large OCDPs. For this algorithm system dynamics, objective function and their first‐order derivatives must be continuous in the state, control and design parameters. The algorithm is successfully applied to the combined control and design problem of a cold store with three possible refrigeration technologies: mechanical refrigeration, ventilation and evaporative cooling. As a result, insight into cost effectiveness of the refrigeration technologies is generated. It is concluded that for this cold store in the Netherlands evaporative cooling is too expensive. Ventilation is economically viable if the cold store is to be used in January only. In case the cold store is to be operated all year then it is most economical to rely on mechanical refrigeration only and use the overcapacity during most part of the year to shift refrigeration to low‐tariff hours. Copyright © 2008 John Wiley & Sons, Ltd.
Delay‐dependent H∞ control for singular Markovian jump systems with time delay
Authors: Wu Zhengguang , Su Hongye , Chu Jian
Published: August 2008

The problem of delay‐dependent H∞ control is considered for singular Markovian jump systems with time delay. The aim of the problem is to design a state feedback controller, which guarantees that the resultant closed‐loop system is not only regular, impulse free and stochastically stable, but also satisfies a prescribed H∞ performance level for all delays no larger than a given upper bound in terms of linear matrix inequality (LMI) approach. A strict LMI condition is developed to guarantee the existence of the desired state feedback controller. An explicit expression for the desired controller is also given. Numerical examples show the effectiveness of the proposed methods. Copyright © 2008 John Wiley & Sons, Ltd.
Morphology, toughness mechanism, and thermal properties of hyperbranched epoxy modified diglycidyl ether of bisphenol A (DGEBA) interpenetrating polymer networks
Authors: Fu Ji‐Fang , Shi Li‐Yi , Yuan Shuai , Zhong Qing‐Dong , Zhang Deng‐Song , Chen Yi , Wu Jun
Published: August 2008

New hyperbranched poly(trimellitic anhydride‐triethylene glycol) ester epoxy (HTTE) is synthesized and used to toughen diglycidyl ether of bisphenol A (DGEBA) 4,4′‐diaminodiphenylmethane (DDM) resin system. The effects of content and generation number of HTTE on the performance of the cured systems are studied in detail. The impact strength is improved 2–7 times for HTTE/DGEBA blends compared with that of the unmodified system. Scanning electron microscopy (SEM) of fracture surface shows cavitations at center and fibrous yielding phenomenon at edge which indicated that the particle cavitations, shear yield deformation, and in situ toughness mechanism are the main toughening mechanisms. The dynamic mechanical thermal analyzer (DMA) analyses suggest that phase separation occurred as interpenetrating polymer networks (IPNs) for the HTTE/DGEBA amine systems. The IPN maintains transparency and shows higher modulus than the neat epoxy. The glass transition temperature (Tg) decreases to some extent compared with the neat epoxy. The Tg increases with increase in the generation number from first to third of HTTE and the concentrations of hard segment. The HTTE leads to a small decrease in thermal stability with the increasing content from TGA analysis. The thermal stability increases with increase in the generation number from first to third. Moreover, HTTE promotes char formation in the HTTE/DGEBA blends. The increase in thermal properties from first to third generation number is attributed to the increase in the molar mass and intramolecular hydrogen bridges, the increasing interaction of the HTTE/DGEBA IPNs, and the increasing crosslinking density due to the availability of a greater number of end hydroxyl and end epoxide functions. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of stretching on structure and properties of polyethylene hollow fiber membranes made by melt‐spinning and stretching process
Authors: Xi Zhen‐yu , Xu You‐Yi , Zhu Li‐Ping , Du Chun‐Hui , Zhu Bao‐ku
Published: August 2008

Microporous polyethylene (PE) hollow fiber membrane was prepared by the melt‐spinning and stretching (MS‐S) method. The effect of stretching on the structure and properties of the membrane was investigated by water contact angle measurement, field emission scanning electron microscopy (FESEM), mercury porosimetry, and N2 permeation. The tensile experiment was used to study the hard elasticity and the mechanical properties of annealed PE fibers. During the stretching process, the stretching temperature, rate, and ratio have great effects on the morphology, crystal structure, pore structure, and N2 permeation of the membrane. Experimental results showed that N2 permeation and porosity of the membrane increased with the increase in stretching temperature, rate, and ratio. The pore size decreased with increase in the stretching rate and increased with the stretching ratio. The pore size distribution was also affected by the stretching process, and was investigated in detail. Copyright © 2008 John Wiley & Sons, Ltd.
Influence of imidazolium‐based ionic liquids on the synthesis of amphiphilic copolymers based on n‐butylmethacrylate and a zwitterionic methacrylate
Authors: Strehmel Veronika , Wetzel Hendrik , Laschewsky André , Moldenhauer Evelin , Klein Thorsten
Published: August 2008

Imidazolium‐based ionic liquids are used as new solvents for the synthesis of statistical copolymers from methacrylates of strongly differing polarities and solubilities, namely of n‐butylmethacrylate and 3‐(N‐2‐[methacryloyloxyethyl]‐N,N dimethyl‐3‐ammonio)propane sulfonate. Though difficult to prepare in classical solvents, true copolymers of these monomers can be obtained in ionic liquids, providing zwitterionic amphiphilic polymers. The relative reactivity of the monomers and thus the copolymer composition is influenced by the ionic liquid used. Analysis of the copolymers using 1H NMR spectroscopy, elemental analysis, and asymmetrical flow field‐flow fractionation (AF4) shows the influence of both the length of the alkyl chain bound at the nitrogen atom of the imidazolium ring and the anion of the ionic liquid on the structure of the copolymers. Furthermore, the highly polar methacrylate with a sulfobetaine moiety is only slightly preferred in copolymerization if ionic liquids are used as solvents for copolymerization. The ratio of monomer segments in the copolymer can be influenced by the selection of the ionic liquid used as a solvent for polymer synthesis and by the variation of the monomer ratio selected for copolymerization if it is carried out in an ionic liquid. This opens new possibilities for a broad variation of amphiphilic copolymer structures obtained through free radical copolymerization of differently polar monomers. Copyright © 2008 John Wiley & Sons, Ltd.
PILs‐based Nafion membranes: a route to high‐temperature PEFMCs dedicated to electric and hybrid vehicles
Authors: Iojoiu Cristina , Martinez Mathieu , Hanna Maha , Molmeret Yannick , Cointeaux Laure , Leprêtre Jean‐Claude , Kissi Nadia El , Guindet Jacques , Judeinstein Patrick , Sanchez Jean‐Yves
Published: August 2008

This paper deals with the performance of anhydrous proton‐conducting polymers obtained by blending modified Nafion® membranes with proton conducting ionic liquids (PILs). It has been shown that the conductivities depend more on the PIL uptake than on its intrinsic conductivity. Conductivities at 130°C approaching those of current Nafion membranes at 80°C and 98% relative humidity were obtained with the best blends. These data allow considering MEA operating at 120–130°C based on membrane and electrodes incorporating these blends. This is clearly a positive feature for an implementation in hybrid vehicles powered by proton exchange membrane fuel cells (PEMFCs) operating above 100°C. Lastly, preliminary results for a PIL based on a half‐neutralized diamine show an improvement in oxidation and, provided that the neutralization is optimized, a neat reinforcement of the Nafion membrane can be expected. Copyright © 2008 John Wiley & Sons, Ltd.
Relationship between responsiveness of cancer cells to Oncostatin M and/or IL‐6 and survival of stage III melanoma patients treated with tumour‐infiltrating lymphocytes
Authors: Lacreusette A , Lartigue A , Nguyen J‐M , Barbieux I , Pandolfino M‐C , Paris F , Khammari A , Dréno B , Jacques Y , Blanchard F , Godard A
Published: August 2008

Immunotherapy by adoptive transfer of autologous tumour‐infiltrating lymphocytes (TIL) shows promising clinical results for stage III (lymph nodes metastasis) melanoma patients, but some of them remain unresponsive. Here we analysed retrospectively the impact of resistance of melanoma cells to anti‐proliferative cytokines on the clinical outcome of 24 TIL‐treated metastatic melanoma patients. Patient relapse‐free survival correlated significantly with Oncostatin M (OSM) and/or IL‐6 sensitivity of melanoma cells, but not with interferon (IFN) γ or tumour necrosis factor (TNF) α sensitivity. However, OSM/IL‐6 sensitivity did not correlate with other known prognostic factors. Moreover, OSM and IL‐6 were produced by TIL just before their injection to patients. In immunodeficient mice, OSM reduced human melanoma xenograft tumour growth, this effect being directly through inhibition of tumour cell proliferation rather than induction of apoptosis or necrosis. Thus, OSM/IL‐6 resistance of melanoma cells appears to be a new escape mechanism to TIL treatment that could be added to the existing prognostic factors for early stage melanoma patients. This mechanism of action could be also relevant in other immunotherapy protocols, and could lead to better prognosis and anti‐cancer treatments. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Thymic Langerhans cell histiocytosis mimicking lymphoma
Authors: Yağcı Begül , Varan Ali , Üner Ayşegül , Akyüz Canan , Büyükpamukçu Münevver
Published: August 2008

Langerhans cell histiocytosis (LCH) is a rare disorder characterized by clonal expansion of antigen presenting Langerhans cells. Different clinical features can be seen according to the involved organs and sytems. Multisystem disease with organ dysfunction is more common in infants, whereas single system disease is usually observed in older children. The disease can affect any system or organ throughout the body. Thymus is a rarely involvement site reported in LCH and usually is accompanied by skin, bone or lung disease. Here we report a 12‐year‐old male with thymic involvement by LCH clinically mimicking lymphoma. Pediatr Blood Cancer 2008;51:833–835. © 2008 Wiley‐Liss, Inc.
Treating Pediatric soft tissue sarcomas in a country with limited resources: The experience of the Unidad Nacional de Oncologia Pediatrica in Guatemala
Authors: Antillon Federico , Castellanos Mauricio , Valverde Patricia , Luna‐Fineman Sandra , Garrido Claudia , Serrato Tania , Rodriguez‐Galindo Carlos , Casanova Michela , Ferrari Andrea
Published: August 2008

Background

About 250–300 children with newly diagnosed cancer are treated each year at the Unidad Nacional de Oncologia Pediatrica in Guatemala City; less than 5% of them have soft tissue sarcomas (STS). The aim of the article was to evaluate whether the therapeutic standards achieved in STS in developed countries could be reproduced in a low‐income country.

Patients and Methods

We reviewed the clinical data, treatment and outcome of 80 patients, 47 cases of rhabdomyosarcoma (RMS) and 33 of non‐rhabdomyosarcoma soft tissue sarcoma (NRSTS), treated between January 2000 and October 2007.

Results

Most of the RMS patients had advanced disease at diagnosis (87% groups III–IV). Their 3‐year event‐free survival rate (EFS) was 26.4% if abandoning the treatment was considered as an event, or 32.4% if it was censored (14 patients abandoned the treatment), and the 3‐year overall survival rate (OS) was 43.5%. Local progression/relapse was the main cause of treatment failure. Among the patients with NRSTS, the EFS at 3 years was 36.4% (when abandoning the treatment was considered as an event) or 43.3% (when it was censored), and the OS was 44.2%. Outcome was satisfactory for synovial sarcoma patients, those with tumors ≤5 cm, and those with localized disease.

Conclusions

Overall results were unsatisfactory compared to results reported from developed countries. Late diagnosis and the consequently high proportion of cases of advanced disease at diagnosis, the large number of patients failing to complete the treatment, and the poor quality of local control (in RMS) adversely influence outcome. Pediatr Blood Cancer 2008;51:760–764. © 2008 Wiley‐Liss, Inc.
Defective in vitro growth of primitive hematopoietic cells from pediatric patients with acute myeloid leukemia
Authors: Dorantes‐Acosta Elisa , Chávez‐González Antonieta , Santos José Ignacio , Medina‐Sanson Aurora , Mayani Hector
Published: August 2008

Background

Acute myeloid leukemia (AML) is a neoplastic hematologic disorder that arises at the level of a primitive stem/progenitor cell. Most studies on the biology of the hematopoietic system in AML have focused on cells from adult patients; much less is known about hematopoietic cells from childhood AML.

Procedure

By using a negative immunoselection system, we have obtained a primitive cell population (enriched for CD34+ Lin− cells) from the bone marrow (BM) of 17 pediatric AML patients and characterized its proliferation, expansion, and differentiation potentials in liquid cultures supplemented with a mixture of 8 different recombinant stimulatory cytokines.

Results

The proportion of CD34+ cells in AML patients was extremely heterogeneous, ranging from 0% to 74%. Regardless of their CD34+ cell content, and in contrast to normal cells, AML cells showed a deficient capacity to proliferate even in the presence of the stimulatory cytokines. AML progenitors were unable to generate new progenitor cells, indicating their inability to expand. Interestingly, AML cells were able to differentiate in culture, giving rise to morphologically recognizable precursors. A major difference, however, as compared to hematopoietic progenitors from normal subjects, was the fact that whereas in cultures of normal cells both myeloid and erythroid precursors were produced, in AML cultures the vast majority of the cells generated corresponded to myeloid cells, mostly mature macrophages.

Conclusion

As compared to their normal counterparts, primitive hematopoietic cells from pediatric patients with AML possess impaired proliferation, expansion, and differentiation potentials in vitro. Pediatr Blood Cancer 2008;51:741–746. © 2008 Wiley‐Liss, Inc.
Intravascular hemolysis following low dose daily rifampin
Authors: Neunert Cindy E. , Paranjape Geeta S. , Cameron Scott , Rogers Zora R.
Published: August 2008

We report two pediatric patients with rifampin‐induced hemolysis following treatment with low daily dose rifampin for methicillin‐resistant Staphylococcus aureus (MRSA). With the increased use of rifampin to treat MRSA, physicians should be aware that patients receiving rifampin therapy are at risk for hemolysis, even at low daily doses. Pediatr Blood Cancer 2008;51:821–823. © 2008 Wiley‐Liss, Inc.
Respiratory syncytial virus infections in children with acute myeloid leukemia: A report from the Children's Oncology Group
Authors: Sung Lillian , Alonzo Todd A. , Gerbing Robert B. , Aplenc Richard , Lange Beverly J. , Woods William G. , Feusner James , Franklin Janet , Patterson Maria J. , Gamis Alan S.
Published: August 2008

Background

Morbidity and mortality related to respiratory syncytial virus (RSV) in pediatric acute myeloid leukemia (AML) is not known.

Procedure

We combined data from three Children's Oncology Group AML studies and determined the prevalence of RSV infection and RSV‐related mortality in children treated for de novo AML.

Results

We found that the prevalence of RSV infection ranged from 0% to 1% in induction and between 0.3 and 2.2% in consolidation. Four children died from RSV resulting in RSV‐specific mortality of 0.2% among all children. However, the risk of RSV‐related mortality among RSV infection episodes was high (4/40, 10%).

Conclusions

RSV infections and deaths are rare in pediatric AML. Pediatr Blood Cancer 2008;51:784–786. © 2008 Wiley‐Liss, Inc.
Effect of nucleating duality on the formation of γ‐phase in a β‐nucleated isotactic polypropylene copolymer
Authors: Na Bing , Lv Ruihua , Xu Wenfei , Chen Rong , Zhao Zunxin , Yi Yong
Published: August 2008

BACKGROUND: It is a challenge for polymer processing to promote the formation of γ‐phase under atmospheric conditions in isotactic polypropylene (iPP) copolymer containing chain errors. Incorporation of an α‐nucleator in iPP copolymer seems reasonable since it can enhance non‐isothermal crystallization. Up to now, however, the issue regarding a β‐nucleated iPP copolymer still remains unclear, which is the subject of this study.

RESULTS: The results indicate that the γ‐phase indeed occurs in a β‐nucleated random iPP copolymer with ethylene co‐unit (PPR) sample and becomes predominant at slow cooling rates (e.g. 1 °C min−1) where the formation of the β‐form is suppressed to a large extent. With detailed morphological observations the formation of γ‐phase in the β‐nucleated PPR sample at slow cooling rate is unambiguously attributed to the nucleating duality of the β‐nucleator towards α‐ and β‐polymorphs. The α‐crystals, induced by the β‐nucleator, serve as seeds for the predominant growth of the γ‐phase. Moreover, the presence of the β‐nucleator, acting as heterogeneous nuclei, promotes the formation of γ‐phase in the nucleated PPR sample, at least to some extent.

CONCLUSION: The findings in this study extend our insights into the formation of γ‐phase in β‐nucleated iPP copolymer and, most importantly, provide an alternative route to obtain iPP rich in γ‐phase. Copyright © 2008 Society of Chemical Industry
Nasal versus face mask for multiple‐breath washout technique in preterm infants
Authors: Schulzke S.M. , Deeptha K. , Sinhal S. , Baldwin D.N. , Pillow J.J.
Published: August 2008

The large dead space associated with face masks might impede the accuracy and feasibility of multiple‐breath washout (MBW) measurements in small infants. We asked if a low dead space nasal mask would provide measurements of resting lung volume and ventilation inhomogeneity comparable to those obtained with a face mask, when using the MBW technique. Unsedated preterm infants breathing without mechanical assistance and weighing between 1.50 and 2.49 kg were studied. Paired MBW tests with nasal and face masks were obtained using sulphur hexafluoride (SF6) as the tracer gas. The order of mask application was quasi‐randomized. Bland–Altman method and intraclass correlation coefficient were used to analyze outcomes. Measurements were obtained in 20 infants with a mean (SD) postmenstrual age of 36 (1.4) w and a test weight of 2.0 (0.3) kg. The mean difference (95% CI) for nasal vs. face mask was −3.2 breaths/min (−6.2, −0.1 breaths/min) for respiratory rate, −1.0 ml/kg (−2.3, 0.3 ml/kg) for lung volume, 0.6 (0.1, 1.1) for lung clearance index, 0.2 (0.1, 0.3) for first to zeroeth moment ratio and 1.33 (0.6, 2.4) for second to zeroeth moment ratio. Paired measurements of lung volume showed acceptable agreement and good correlation, but there was poor agreement and poor correlation between indices of ventilation inhomogeneity obtained with the two masks. Functional dead space of the nasal mask was similar to that of the face mask despite its smaller water displacement volume. During MBW in infants below 2.5 kg body weight, a nasal mask results in comparable lung volume measurements. Indices of ventilation inhomogeneity may not be directly comparable using masks with different dead space. Pediatr Pulmonol. 2008; 43:858–865. © 2008 Wiley‐Liss, Inc.
The effect of fenugreek 4‐hydroxyisoleucine on liver function biomarkers and glucose in diabetic and fructose‐fed rats
Authors: Haeri Mohammad Reza , Izaddoost Mohammad , Ardekani Mohammad Reza Shams , Nobar Mohammad Rahbani , White Kenneth N.
Published: August 2008

Fenugreek (Trigonella foenum graecum L) is a plant traditionally used for the treatment of diabetes. It contains an unusual amino acid, 4‐hydroxyisoleucine, demonstrated to have insulinotropic and antidiabetic properties in animal models. Here we examine the effect of 4‐hydroxyisoleucine on liver function and blood glucose in two rat models of insulin resistance, fructose‐fed rats and streptozotocin‐induced diabetes type 2. In fructose‐fed rats, levels of glucose and liver damage marker aspartate transaminase were markedly (84% and 93%, respectively) and significantly elevated compared with controls (p < 0.001 for both). Alanine transaminase was elevated slightly (18%), and all markers were restored to near control values after treatment with 4‐hydroxyisoleucine at 50 mg/kg per day for 8 weeks, the effect being significant (p < 0.01) for all markers. This prolonged exposure to 4‐hydroxyisoleucine was well tolerated in control animals and did not alter levels of glucose or liver damage markers significantly. In diabetic rats, treatment with 4‐hydroxyisoleucine did not affect glucose or liver damage markers, but did improve HDL‐cholesterol levels (31% increase, p < 0.05). These findings indicate 4‐hydroxyisoleucine as a useful and well‐tolerated treatment for insulin resistance, both directly as a hypoglycaemic and also as a protective agent for the liver. Copyright © 2008 John Wiley & Sons, Ltd.
Using the Rosetta algorithm and selected inter‐residue distances to predict protein structure
Authors: Crecca Christina , Roitberg Adrian E.
Published: August 2008

The Rosetta algorithm has had much success in protein structure prediction as demonstrated in the recent Critical Assessment of Protein Structure Prediction (CASP) experiments. For many proteins, Rosetta generates several low root mean square deviation (RMSD) decoy structures but finding the best structure among the decoys can be difficult. Experimental data can be used to aid in the discrimination process. Our protein structure prediction method involves three steps: using the Rosetta algorithm to generate decoys, measuring inter‐residue distances, and comparing the measured distances with those calculated in each decoy. Decoys with similar three‐dimensional structure will also have several similar inter‐residue distances. To develop our search protocol, we determined the optimal number of decoys to generate as well as the minimum number of distance constraints needed to distinguish between the low and high RMSD structures. To test our method, we simulate experimental data by measuring α‐carbon distances from the experimentally determined structures of our target proteins. We have employed the Rosetta algorithm to generate decoy sets of different sizes for four target proteins. Our predicted structures ranged in Cα RMSD from 2.4 to 4.6 Å compared with the experimental structures. Using only twenty‐five distance constraints, reliable predictions were made. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008