bluuebunny/crossref_metadata_2025_split huggingface dataset:
HMGA1a Protein Unfolds or Refolds Synthetic DNA–Chromophore Hybrid Polymers: A Chaperone‐Like Behavior
Authors: Wan Wei , Wang Wei , Li Alexander D. Q. 
Published: December 2007

AbstractHigh group mobility protein, HMGA1a, was found to play a chaperone‐like role in the folding or unfolding of hybrid polymers that contained well‐defined synthetic chromophores and DNA sequences. The synthetic and biological hybrid polymers folded into hydrophobic chromophoric nanostructures in water, but existed as partially unfolded configurations in pH or salt buffers. The presence of HMGA1a induced unfolding of the hybrid DNA–chromophore polymer in pure water, whereas the protein promoted refolding of the same polymer in various pH or salt buffers. The origin of the chaperone‐like properties probably comes from the ability of HMGA1a to reversibly bind both synthetic chromophores and single stranded DNA. The unfolding mechanisms and the binding stoichiometry of protein–hybrid polymers depended on the sequence of the synthetic polymers.
Introducing Negative Charges into Bis‐p‐phenylene Crown Ethers: A Study of Bipyridinium‐Based [2]Pseudorotaxanes and [2]Rotaxanes
Authors: Lestini Elena , Nikitin Kirill , Müller‐Bunz Helge , Fitzmaurice Donald 
Published: December 2007

AbstractThis paper describes novel host–guest systems comprising viologen cations (guests) and the derivatives of bis‐para‐phenylene‐34‐crown‐10 (hosts) with anionic groups COO− or SO3−. The structure of the resulting charge‐compensated host–guest complexes, their association constants and their electrochemical behaviour have been studied. In the solid state, the viologen cations thread the negatively charged crown ethers forming electroneutral zwitterion‐like [2]pseudorotaxane salts; in solution this threaded geometry is preserved. The association constants of [2]pseudorotaxane salts incorporating the 1,1′‐diethylviologen moiety in solution are significantly higher than those of previously reported analogues. The extrapolated association free energies in non‐aqueous media exceed −40 kJ⋅ mol−1 at 25 °C. This significant increase of the interaction free energy makes these compounds stable even in aqueous solutions. The association constants of [2]pseudorotaxane salts incorporating sterically more hindered 1,1′‐diethyl‐3,3′‐dimethylviologen moieties are significantly lower. Structurally related [2]rotaxane salts, in which the oppositely charged ionic components are mechanically interlocked, have been prepared in good yields. It has been shown that [2]rotaxane salts incorporating anti‐isomers of bisfunctionalised crown ethers are cycloenantiomeric. In both [2]pseudorotaxane and [2]rotaxane salts, the electrostatic interactions between the viologen moieties and the negatively charged crown ethers lead to very significant negative shifts of viologen reduction potentials up to 450 mV. The findings of the present study are valuable for the design of nanoscale molecular electronic devices.
Expression of P2X3 receptor in the trigeminal sensory nuclei of the rat
Authors: Kim Yun Sook , Paik Sang Kyoo , Cho Yi Sul , Shin Ho Seob , Bae Jin Young , Moritani Masayuki , Yoshida Atsushi , Ahn Dong Kuk , Valtschanoff Juli , Hwang Se Jin , Moon Cheil , Bae Yong Chul 
Published: December 2007

AbstractTrigeminal primary afferents expressing P2X3 receptor are involved in the transmission of orofacial nociceptive information. However, little is known about their central projection pattern and ultrastructural features within the trigeminal brainstem sensory nuclei (TBSN). Here we use multiple immunofluorescence and electron microscopy to characterize the P2X3‐immunopositive (+) neurons in the trigeminal ganglion and describe the distribution and synaptic organization of their central terminals within the rat TBSN, including nuclei principalis (Vp), oralis (Vo), interpolaris (Vi), and caudalis (Vc). In the trigeminal ganglion, P2X3 immunoreactivity was mainly in small and medium‐sized somata, but also frequently in large somata. Although most P2X3+ somata costained for the nonpeptidergic marker IB4, few costained for the peptidergic marker substance P. Most P2X3+ fibers in the sensory root of trigeminal ganglion (92.9%) were unmyelinated, whereas the rest were small myelinated. In the TBSN, P2X3 immunoreactivity was dispersed in the rostral TBSN but was dense in the superficial laminae of Vc, especially in the inner lamina II. The P2X3+ terminals contained numerous clear, round vesicles and sparse large, dense‐core vesicles. Typically, they were presynaptic to one or two dendritic shafts and also frequently postsynaptic to axonal endings, containing pleomorphic vesicles. Such P2X3+ terminals, showing glomerular shape and complex synaptic relationships, and those exhibiting axoaxonic contacts, were more frequently seen in Vp than in any other TBSN. These results suggest that orofacial nociceptive information may be transmitted via P2X3+ afferents to all TBSN and that it may be processed differently in different TBSN. J. Comp. Neurol. 506:627–639, 2008. © 2007 Wiley‐Liss, Inc.
On the effectiveness of runtime techniques to reduce memory sharing overheads in distributed Java implementations
Authors: Lobosco Marcelo , Loques Orlando , de Amorim Claudio L. 
Published: December 2007

AbstractDistributed Java virtual machine (dJVM) systems enable concurrent Java applications to transparently run on clusters of commodity computers. This is achieved by supporting Java's shared‐memory model over multiple JVMs distributed across the cluster's computer nodes. In this work, we describe and evaluate selective dynamicdiffingand lazy home allocation, two new runtime techniques that enable dJVMs to efficiently support memory sharing across the cluster. Specifically, the two proposed techniques can contribute to reduce the overheads due to message traffic, extra memory space, and high latency of remote memory accesses that such dJVM systems require for implementing their memory‐coherence protocol either in isolation or in combination. In order to evaluate the performance‐related benefits of dynamicdiffingand lazy home allocation, we implemented both techniques in Cooperative JVM (CoJVM), a basic dJVM system we developed in previous work. In subsequent work, we carried out performance comparisons between the basic CoJVM and modified CoJVM versions for five representative concurrent Java applications (matrix multiply, LU, Radix, fast Fourier transform, and SOR) using our proposed techniques. Our experimental results showed that dynamicdiffingand lazy home allocation significantly reduced memory sharing overheads. The reduction resulted in considerable gains in CoJVM system's performance, ranging from 9% up to 20%, in four out of the five applications, with resulting speedups varying from 6.5 up to 8.1 for an 8‐node cluster of computers. Copyright © 2007 John Wiley & Sons, Ltd.
Calculation of the Evolution of Surface Area and Free Volume During the Infiltration of Fiber Felts
Authors: Pfrang A. , Schladitz K. , Wiegmann A. , Schimmel T. 
Published: December 2007

AbstractThe evolution of surface area and free volume during the infiltration of fiber felts is calculated quantitatively and compared with experimental data. For overlapping fibers the evolution is approximated by a Boolean model, where the ratio of surface area to free volume increases linearly with the radius of the fibers. For randomly distributed fibers which do not overlap in the initial state, the evolution of surface area and free volume is calculated numerically. The surface area/free volume ratio increases nearly linearly for all initial filling factors and for all degrees of orientation anisotropy of the fibers.
Synthesis of (4R,15R,16R,21S)‐Rollicosin and Its 4S Epimer
Authors: Wu Ming‐Jung , Lee Cheng‐Lin , Wu Yang‐Chang , Chen Chiao‐Pei 
Published: December 2007

Abstract(4R,15R,16R,21S)‐Rollicosin (2) was synthesized by palladium‐catalyzed coupling of two building blocks 4 and 5. Lactone 4 was synthesized from 1‐heptyne and terminal acetylene 5 was prepared from lactone 6 and allyl iodide or (S)‐epichlorohydrin. (4S,15R,16R,21S)‐Rollicosin (3) was also synthesized from (R)‐epichlorohydrin by the same synthetic pathway.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Separation of very hydrophobic analytes by micellar electrokinetic chromatography. I. Optimization of the composition of the sample solution for the determination of the aromatic ingredients of sassafras and other essential oils of forensic interest
Authors: Huhn Carolin , Pütz Michael , Holthausen Ivie , Pyell Ute 
Published: December 2007

AbstractA micellar electrokinetic chromatographic method using UV and (UV)LIF detection in‐line was developed for the determination of aromatic constituents, mainly allylbenzenes in essential oils. The method optimization included the optimization of the composition of the separation electrolyte using ACN and urea to reduce retention factors and CaCl2 to widen the migration time window. In addition, it was necessary to optimize the composition of the sample solution which included the addition of a neutral surfactant at high concentration. With the optimized method, the determination of minor constituents in essential oils was possible despite of the presence of a structurally related compound being in a molar ratio excess of 1000:1. The use of UV and LIF‐detection in‐line enabled the direct comparison of the two detection traces using an electrophoretic mobility x‐axis instead of the normal time‐based scale. This simplifies the assignment of signals and enhances repeatability. The method developed was successfully applied to the determination of minor and major constituents in herbal essential oils, some of them being forensically relevant as sources of precursors for synthetic drugs.
Fast CE for combinatorial catalysis
Authors: Breadmore Michael C. , Hodgson Richard , Kennedy Danielle F. , Messerle Barbara A. 
Published: December 2007

AbstractTwo solvent‐modified MEKC methods were developed for the quantitative analysis of heterocyclic amines synthesised using intramolecular ring closure via catalysed hydroamination. The first method was capable of resolving six of the amines (precursors and products) with a sample‐to‐sample injection time of 2 min employing a 20 mM borate buffer, pH 9.2 with 20 mM SDS and 5% v/v n‐butanol (n‐BuOH). A second low‐pH method using 20 mM phosphate buffer, 100 mm SDS, 5% v/v n‐BuOH and 20% v/v iso‐propanol (i‐PrOH) was able to resolve an additional pair of compounds with a sample‐to‐sample time of 3.5 min. Application of the first method to the analysis of a sample containing catalyst as well as amines placed directly in a 96‐well plate showed excellent performance, with migration time and peak height and area reproducibility being less than 0.9 and 9.6%, respectively. The quantity of conversion by catalyst was calculated to be 68 ± 7%, which was in excellent agreement with the 67 ± 5% obtained by more conventional 1H NMR experiments, with the added advantage that this method is also cheaper, quicker and more amendable to high‐throughput screening of combinatorial libraries.
Evaluation of band broadening in chemiluminescence detection coupled to pressurized capillary electrochromatography with an off‐column coaxial flow interface
Authors: Lin Zian , Lin Jian , Wu Xiaoping , Lin Xucong , Xie Zenghong 
Published: December 2007

AbstractA system of off‐column coaxial flow chemiluminescence (CL) detection coupled to pressurized CEC (pCEC) was described. The interface utilized a reactor that introduced postcolumn CL reagent into the capillary effluents in a sheathing flow profile. To compare and evaluate band broadening of analytes caused by the detector, the typical CL compounds luminol and N‐(4‐aminobutyl)‐N‐ethylisoluminol (ABEI) were separated and detected by pCEC or capillary HPLC (cHPLC) coupled to CL and UV detector, respectively. The results demonstrated that the band broadening caused by off‐column detection interface was minimized due to the fast kinetic nature of the CL reaction. With the proposed pCEC‐CL system, the detection limits of luminol and ABEI were 1.0×10−8 and 8.0×10−8 mol/L, respectively, which were approximately 100‐fold more sensitive than those obtained with UV absorption. In addition, separation and detection of the ABEI‐labeled L‐lysine (L‐Lys) and L‐arginine (L‐Arg) were accomplished by pCEC‐CL method based on the principle of ABEI‐potassium ferricyanide‐alkaline medium CL reaction system. Under the optimum conditions, good results could be achieved compared with pCEC‐UV.
Meteorin regulates angiogenesis at the gliovascular interface
Authors: Park Jeong Ae , Lee Hye Shin , Ko Keum Jae , Park Soo Youn , Kim Jeong Hun , Choe Gheeyoung , Kweon Hee‐Seok , Song Hyun Seok , Ahn Jong‐Chan , Yu Young Suk , Kim Kyu‐Won 
Published: December 2007

AbstractBrain microvasculature requires a coordinated interaction between endothelial cells and astrocytes at the gliovascular interface. However, the role of the factors involved in that interaction and expressed by these cells is poorly understood. In this study, we demonstrate that Meteorin is highly expressed in astrocytes of the brain and retina during the late embryonic and postnatal stages of mouse development. Most notably, Meteorin is localized to the astrocyte endfeet that surround the blood vessels. To investigate the role of Meteorin in perivascular astrocytes, we depleted endogenous levels of Meteorin in cultured astrocytes using siRNA, and found that Meteorin attenuates angiogenic activity indirectly via astrocyte‐derived thrombospondin‐1/‐2 (TSP‐1/‐2). Exogenous treatment of astrocytes with Meteorin protein also promotes astrocyte expression and secretion of TSP‐1/‐2. The conditioned media from the Meteorin‐treated astrocytes attenuated angiogenic activity of microvascular endothelial cells. This activity was reversed by inhibiting the binding of TSP‐1/‐2 to its receptor. Furthermore, we found that TSP‐1/‐2 was co‐localized with Meteorin in the developing brain. Therefore, our data strongly suggests that Meteorin is expressed and secreted by perivascular astrocytes and the secreted protein upregulates TSP‐1/‐2 to attenuate angiogenesis in the surrounding endothelial cells and to promote vascular maturation. © 2007 Wiley‐Liss, Inc.
Dickkopf‐3 expression is a marker for neuroblastic tumor maturation and is down‐regulated by MYCN
Authors: Koppen Arjen , Ait‐Aissa Rachida , Koster Jan , Øra Ingrid , Bras Johannes , van Sluis Peter G. , Caron Huib , Versteeg Rogier , Valentijn Linda J. 
Published: December 2007

AbstractNeuroblastoma and ganglioneuroma are neuroblastic tumors originating from the developing sympathetic peripheral nervous system. Ganglioneuromas are usually benign, while neuroblastomas have a variable prognosis and include very aggressive tumors. Examples exist of neuroblastomas regressing to ganglioneuromas and ganglioneuromas progressing to neuroblastomas. Little is known of the molecular differences between the tumor types. Here we report that Dickkopf‐3 (DKK3), a putative extra cellular inhibitor of the Wnt/β‐catenin pathway, showed a strongly differential expression between neuroblastoma and ganglioneuroma. Microarray analyses of 109 neuroblastic tumors revealed that DKK3 is strongly expressed in ganglioneuroma but only weakly in neuroblastoma. Low DKK3 expression in neuroblastoma correlated with a poor prognosis. The expression of DKK3 in the tumor series and in neuroblastoma cell lines was inversely correlated with the expression of the MYCN oncogene. Analysis of 2 neuroblastoma cell lines with inducible activity of MYCN showed that DKK3 is down‐regulated by MYCN. We subsequently generated cell lines with inducible expression of DKK3, which revealed an inhibitory effect of DKK3 on proliferation. High DKK3 expression in the benign ganglioneuromas and down‐regulation of DKK3 by MYCN in neuroblastoma might contribute to the strongly different clinical behavior of both neuroblastic tumor types. © 2007 Wiley‐Liss, Inc.
4‐Vinyl‐2,6‐dimethoxyphenol (canolol) suppresses oxidative stress and gastric carcinogenesis in Helicobacter pylori‐infected carcinogen‐treated Mongolian gerbils
Authors: Cao Xueyuan , Tsukamoto Tetsuya , Seki Takahiro , Tanaka Harunari , Morimura Shigeru , Cao Liyu , Mizoshita Tsutomu , Ban Hisayo , Toyoda Takeshi , Maeda Hiroshi , Tatematsu Masae 
Published: December 2007

AbstractOxidative stress is linked to gastric carcinogenesis because of its ability to damage DNA. Here we examined antioxidative and anti‐inflammatory effects of 4‐vinyl‐2,6‐dimethoxyphenol (canolol), a recently identified potent antioxidative compound obtained from crude canola oil, on Helicobacter (H.) pylori‐induced gastritis and gastric carcinogenesis using a Mongolian gerbil model. The animals were allocated to H. pylori‐infection alone (12 weeks) or H.pylori + N‐methyl‐N‐nitrosourea (MNU) administration (52 weeks). After oral inoculation of H. pylori, they were fed for 10 and 44 weeks with or without 0.1% canolol. H. pylori‐induced gastritis, 5′‐bromo‐2′‐deoxyuridine (BrdU) labeling and scores for cyclooxygenase‐2 (COX‐2) and inducible nitric oxide synthase (iNOS) immunohistochemistry were attenuated in the canolol‐treated groups. Expression of interleukin‐1β (IL‐1β), tumor necrosis factor‐α (TNF‐α), COX‐2 and iNOS mRNA in the gastric mucosa, and serum 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG), anti‐H. pylori IgG and gastrin levels were also significantly lower in canolol‐treated groups. Furthermore, the incidence of gastric adenocarcinomas was markedly reduced in the H. pylori + MNU + canolol‐treated group [15.0% (6/40)] compared to the control group [39.4% (13/33)] (p < 0.05). These data indicate canolol to be effective for suppressing inflammation, gastric epithelial cell proliferation and gastric carcinogenesis in H. pylori‐infected Mongolian gerbils. Interestingly, the viable H. pylori count was not changed by the canolol containing diet. Thus, the data point to the level of inflammation because of H. pylori rather than the existence of the bacteria as the determining factor. Importantly, canolol appears to suppress induction of mRNAs for inflammatory cytokines. © 2007 Wiley‐Liss, Inc.
β2‐adrenergic receptors expressed on murine chondrocytes stimulate cellular growth and inhibit the expression of Indian hedgehog and collagen type X
Authors: Lai Lick Pui , Mitchell Jane 
Published: December 2007

AbstractThe sympathetic nervous system has been demonstrated to have a role in regulating bone remodeling through β‐adrenergic receptors (β‐AR) expressed on osteoblasts. Studies using β2‐adrenergic receptor agonists in vivo have also suggested an effect on endochondral bone development; however, it was not clear if this effect was mediated through osteoblasts or chondrocytes. To more thoroughly examine the role of β‐AR in chondrocytes we characterized the expression and signal transduction systems activated by β‐AR in growth plate chondrocytes prepared from ribs of embryonic E18.5 mice. Using RT‐PCR and immunohistochemistry we found that the chondrocytes expressed only β2‐AR. The receptors were coupled to stimulation of adenylyl cyclase, phosphorylation of the cyclic AMP response element binding protein (CREB) and extracellular signal‐regulated kinase (ERK1/2). Stimulation of ERK1/2 was transient and limited by the concomitant stimulation of the mitogen‐activated protein kinase phosphatase (MKP‐1). Isoproterenol stimulated the growth of chondrocytes as assessed by increased incorporation of [3H]‐thymidine into the cells. The cellular expression of two markers of chondrocyte differentiation, Indian hedgehog, expressed in pre‐hypertrophic cells and collagen type X, expressed in hypertrophic chondrocytes, were both significantly inhibited after incubation with isoproterenol. Collectively, these findings demonstrate regulation of chondrocytes through β2‐AR expressed on the cells that stimulate their growth and inhibit their differentiation, indicating that the sympathetic nervous system may be an important regulator of embryonic cartilage development. J. Cell. Biochem. 104: 545–553, 2008. © 2007 Wiley‐Liss, Inc.
Early antenatal diagnosis of spina bifida presenting with a “step” in the posterior contour of an 8‐week embryo
Authors: Lulla Chander , Hegde Amogh , Shah Jatin , Sheth Jayesh 
Published: December 2007

AbstractWe report a case of spina bifida in the upper thoracic spine with an accompanying meningocoele suspected at 8 weeks' gestation via transvaginal sonography and confirmed at 13 weeks' gestation via 3‐dimensional sonography. The fetal cranial vault and intracranial structures were normal. The only finding in the 8‐week sonogram was a subtle angulation or “step” in the posterior contour of the embryo; this may be attributed to kyphosis, which often accompanies this condition. The presence of a “step” in the fetal contour must alert the sonologist to the possibility of spina bifida. To our knowledge, this is the earliest antenatal diagnosis of spina bifida. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
AAV‐mediated knockdown of phospholamban leads to improved contractility and calcium handling in cardiomyocytes
Authors: Andino Lourdes M. , Takeda Morihiko , Kasahara Hideko , Jakymiw Andrew , Byrne Barry J. , Lewin Alfred S. 
Published: December 2007

AbstractBackgroundReduced contractility due to dysregulation of intracellular calcium (Ca2+) is a common pathologic feature of chronic heart failure. Calcium stores in the sarcoplasmic reticulum play a major role in regulating cardiac contractility. Several animal models of heart failure have been treated by altering the regulation of the sarcoplamic reticulum ATPase through ablation or down‐regulation of its inhibitor peptide, phospholamban (PLN).MethodsWe have designed two small hairpin RNAs (shRNAs) to block the synthesis of PLN via RNA interference. These were tested in cell culture using a co‐transfection assay and using adeno‐associated virus (AAV)‐mediated delivery to cardiomyocytes. Reverse‐transcription polymerase chain reaction (RT‐PCR) and Western blots were used to measure reduction in PLN mRNA and protein levels. Reduction of PLN was also documented by indirect immunofluorescence. Free cytosolic calcium and contractile properties of transduced cardiomyocytes was examined on fura‐2‐loaded cells. Direct cardiac injection was used to deliver AAV1‐shRNAs to mice, and reduction of PLN was measured by indirect immunofluorescence.ResultsBoth siRNAs led to significant reduction of PLN RNA and protein levels in cultured cells. Down‐regulation of PLN led to enhanced cell shortening and relaxation and to a decrease in the time constant of calcium decay, signs of improved contractility and calcium handling. In the hearts of AAV‐infected mice, shRNA‐transduced cells showed significant reduction in the level of PLN.ConclusionsOur results suggest that AAV‐delivered shRNAs mediated physiologically significant suppression of phospholamban that may be useful in combating the effects of chronic heart failure. Copyright © 2007 John Wiley & Sons, Ltd.