bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increased Single‐Nucleotide Discrimination in Allele‐Specific Polymerase Chain Reactions through Primer Probes Bearing Nucleobase and 2′‐Deoxyribose Modifications
Authors: Kranaster Ramon , Marx Andreas 
Published: April 2007

AbstractThe diagnosis of genetic dissimilarities between individuals is becoming increasingly important due to the discovery that these variations are related to complex phenotypes like the predisposition to certain diseases or compatibility with drugs. The most common among these sequence variations are single‐nucleotide polymorphisms (SNPs). The availability of reliable and efficient methods for the interrogation of the respective genotypes is the basis for any progress along these lines. Many methods for the detection of nucleotide variations in genes exist, in which amplification of the target gene is required before analysis can take place. The allele‐specific polymerase chain reaction (asPCR) combines target amplification and analysis in a single step. The principle of asPCR is based on the formation of matched or mismatched primer–target complexes. The most important parameter in asPCR is the discrimination of these matched or mismatched pairs. In recent publications we have shown that the reliability of SNP detection through asPCR is increased by employing chemically modified primer probes. In particular, primer probes that bear a polar 4′‐C‐methoxymethylene residue at the 3′ end have superior properties in discriminating single‐nucleotide variations by PCR. Here we describe the synthesis of several primer probes that bear nucleobase modifications in addition to the 4′‐C‐methoxymethylenated 2′‐deoxyriboses. We studied the effects of these alterations on single‐nucleotide discrimination in allele‐specific PCR promoted by a DNA polymerase and completed these results with single‐nucleotide‐incorporation kinetic studies. Moreover, we investigated thermal denaturing of the primer‐probe–template complexes and recorded circular dichroism (CD) spectra for inspecting the thermodynamic and photophysical duplex behaviour of the introduced modifications. In short, we found that primer probes bearing a 4′‐C‐methoxymethylene residue at the 2′‐deoxyribose moiety in combination with a thiolated thymidine moiety have synergistic effects and display significantly increased discrimination properties in asPCR.
Heat‐Induced Alterations in the Surface Population of Metal Sites in Bimetallic Nanoparticles
Authors: Hwang Bing‐Joe , Sarma Loka Subramanyam , Wang Guo‐Rung , Chen Ching‐Hsiang , Liu Din‐Goa , Sheu Hwo‐Shuenn , Lee Jyh‐Fu 
Published: April 2007

AbstractThe ability to alter the surface population of metal sites in bimetallic nanoparticles (NPs) is of great interest in the context of heterogeneous catalysis. Here, we report findings of surface alterations of Pt and Ru metallic sites in bimetallic carbon‐supported (PtRu/C) NPs that were induced by employing a controlled thermal‐treatment strategy. The thermal‐treatment procedure was designed in such a way that the particle size of the initial NPs was not altered and only the surface population of Pt and Ru was changed, thus allowing us to deduce structural information independent of particle‐size effects. X‐ray absorption spectroscopy (XAS) was utilized to deduce the structural parameters that can provide information on atomic distribution and/or extent of alloying as well as the surface population of Pt and Ru in PtRu/C NPs. The PtRu/C catalyst sample was obtained from Johnson Matthey, and first the as‐received catalyst was reduced in 2 % H2 and 98 % Ar gas mixture at 300 °C for 4 h (PtRu/C as‐reduced). Later this sample was subjected to thermal treatment in either oxygen (PtRu/C‐O2‐300) or hydrogen (PtRu/C‐H2‐350). The XAS results reveal that when the as‐reduced PtRu/C catalyst was exposed to the O2 thermal‐treatment strategy, a considerable amount of Ru was moved to the catalyst surface. In contrast, the H2 thermal‐treatment strategy led to a higher population of Pt on the PtRu/C surface. Characterization of the heat‐treated PtRu/C samples by X‐ray diffraction and transmission electron microscopy reveals that there is no significant change in the particle size of thermally treated samples when compared to the as‐received PtRu/C sample. The electrochemical properties of the as‐reduced and heat‐treated PtRu/C catalyst samples were confirmed by cyclic voltammetry, CO‐adsorption stripping voltammetry, and linear sweep voltammetry. Both XAS and electrochemical investigations concluded that the PtRu/C‐H2‐350 sample exhibits significant enhancement in reactivity toward methanol oxidation as a result of the increased surface population of the Pt when compared to the PtRu/C‐O2‐300 and PtRu/C as‐reduced samples.
Antiestrogenic effect of 20S‐protopanaxadiol and its synergy with tamoxifen on breast cancer cells
Authors: Yu Yan , Zhou Qun , Hang Yan , Bu Xuexian , Jia William 
Published: April 2007

AbstractBACKGROUND.20S‐protopanaxadiol (aPPD) is a major gastrointestinal metabolic product of ginsenosides. The latter share structural similarity with steroids and are the main pharmacologically active component in ginseng.METHODS.The authors investigated the interaction between aPPD and estrogen receptors (ER) in human breast adenocarcinoma MCF‐7 cells through receptor binding assay, ER‐induced gene expression, and cell proliferation both in vitro and in vivo.RESULTS.aPPD, but not its close analog ginsenosides, competed with the [3H]‐17‐β estradiol (E2) for ER with IC50 at 26.3 μM. aPPD alone weakly induced luciferase reporter‐gene expression controlled by an estrogen‐regulated element, which was completely blocked by tamoxifen. aPPD alone, or in synergy with tamoxifen, blocked E2‐induced transcriptional activation. aPPD also inhibited colony formation of endometrial cancer cells. aPPD potently inhibited estrogen‐stimulated MCF‐7 cell proliferation and synergistically enhanced the cytotoxicity of tamoxifen on both ER+ MCF‐7 and ER− MDA‐MB231 cells. Furthermore, aPPD, but not tamoxifen, inhibited Akt phosphorylation. Growth of MCF‐7 xenograft tumor supplemented with E2 was completely inhibited in animals treated with aPPD, tamoxifen, or aPPD plus tamoxifen.CONCLUSIONS.These results suggested that aPPD inhibits estrogen‐stimulated gene expression and cell proliferation in ER‐positive breast cancer cells. In addition, aPPD synergistically enhances cytotoxicity of tamoxifen in an ER‐independent fashion, probably by down‐regulating Akt activity. Cancer 2007. © 2007 American Cancer Society.
High‐throughput enhancer trap by remobilization of transposonMinosinCiona intestinalis
Authors: Awazu Satoko , Matsuoka Terumi , Inaba Kazuo , Satoh Nori , Sasakura Yasunori 
Published: April 2007

AbstractThe enhancer trap approach utilizing transposons yields us information about gene functions and gene expression patterns. In the ascidianCiona intestinalis, transposon‐based transgenesis and insertional mutagenesis were achieved with a Tc1/marinertransposonMinos. We report development of a novel technique for enhancer trap inC. intestinalis. This technique uses remobilization ofMinosin theCionagenome. AMinosvector for enhancer trap was constructed and a tandem array insertion of the vector was introduced into theCionagenome to create a mutator line.Minoswas remobilized inCionachromosomes to create new insertions by providing transposases. These transposase‐introduced animals were crossed with wild‐type animals. Nearly 80% of F1 families showed novel GFP expression patterns. This high‐throughput enhancer trap screen will be useful to create new marker transgenic lines showing reporter gene expression in specific tissues and to identify novel patterns of gene expression. genesis 45:307–317, 2007. © 2007 Wiley‐Liss, Inc.
On In Situ Prepared Cu–Phenanthroline Complexes in Aqueous Alkaline Solutions and Their Use in the Catalytic Oxidation of Veratryl Alcohol
Authors: Korpi Heikki , Figiel Paweł J. , Lankinen Elina , Ryan Paul , Leskelä Markku , Repo Timo 
Published: April 2007

AbstractThe in situ prepared complex based on copper(II) sulfate and 1,10‐phenanthroline (phen) and its performance in the catalytic oxidation of veratryl alcohol (3,4‐dimethoxybenzyl alcohol) to veratraldehyde with O2 in alkaline aqueous solutions have been studied. In aqueous solution, the structure of Cu–phen complexes varies with reaction conditions; by changing either the copper‐to‐ligand molar ratio or the pH, the amount of coordinated 1,10‐phenanthroline and hydroxido ligands in the coordination sphere of copper can be altered in a controlled manner. The highest activities are achieved in the pH range 12.6–13.3, which correlates with the presence of the [Cu(phen)(OH)2] species according to complex distribution curves. According to the UV/Vis and EPR studies, the oxidation reaction is initiated by the reduction of [Cu(phen)(OH)2] to CuI species by veratryl alcohol, which can be seen as a disappearance of the Cu2+ EPR signal and as a shift of the UV/Vis absorbance maximum from about 690 nm to the 410 and 525 nm regions. When molecular oxygen is added, the CuI species is readily oxidised back to CuII species, and the catalytic formation of aldehyde is initiated. On the basis of these observations, a mechanism for the catalytic oxidation is proposed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Pirouetting Copper(I)‐Assembled Pseudo‐Rotaxanes: Strong Influence of the Axle Structure on the Motion Rate
Authors: Collin Jean‐Paul , Durola Fabien , Mobian Pierre , Sauvage Jean‐Pierre 
Published: April 2007

AbstractBased on the gathering and threading effect of copper(I), three different pseudo‐rotaxanes have been prepared and characterised in solution. They consist of the same two‐chelate ring and various coordinating fragments threaded through the ring. The ring‐incorporated chelates are a 2,2′,6′,6″‐terpyridine (terpy) unit and a 2,9‐diphenyl‐1,10‐phenanthroline (dpp) motif. The threaded chelates are a 2,9‐bis(p‐anisyl)‐1,10‐phenanthroline (dap), a 6,6′‐bis(p‐anisyl)‐2,2′‐bipyridine (dabipy) or a 8,8′‐diphenyl‐3,3′‐biisoquinoline (dpbiiq) derivative. Using electrochemical techniques, the pirouetting motions of the axle within the ring through which it is threaded have been investigated. In dichloromethane/acetonitrile, a strong dependence of the motion rate on the structure of the threaded chelate has been observed, evidencing that rigidity of the thread‐contained chelate and steric hindrance lead to slow moving molecular machines. Pirouetting is the main dynamic process observed but unthreading of the string‐like organic component represents another minor electrochemically induced reaction.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
A Highly Enantioselective and Catalytic Aryl Transfer Reaction Using Mixed Triarylbismuthane and Dialkylzinc Reagents
Authors: Sato Itaru , Toyota Yousuke , Asakura Noriaki 
Published: April 2007

AbstractHighly enantioselective and catalytic aryl transfer reactions to aromatic aldehydes by using mixed triarylbismuthane and dimethylzinc reagents were studied. In the presence of a chiral β‐amino alcohol catalyst, chiral diarylmethanols with up to 97 % ee were obtained. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
A dynamic process convolution approach to modeling ambient particulate matter concentrations
Authors: Calder Catherine A. 
Published: April 2007

AbstractElevated levels of particulate matter (PM) in the ambient air have been shown to be associated with certain adverse human health effects. As a result, monitoring networks that track PM levels have been established across the United States. Some of the older monitors measure PM less than 10 µm in diameter (PM10), while the newer monitors track PM levels less than 2.5 µm in diameter (PM2.5); it is now believed that this fine component of PM is more likely to be related to the negative health effects associated with PM. We propose a bivariate dynamic process convolution model for PM2.5 and PM10 concentrations. Our aim is to extract information about PM2.5 from PM10 monitor readings using a latent variable approach and to provide better space‐time interpolations of PM2.5 concentrations compared to interpolations made using only PM2.5 monitoring information. We illustrate the approach using PM2.5 and PM10 readings taken across the state of Ohio in 2000. Copyright © 2007 John Wiley & Sons, Ltd.
Analysis of risk factors predicting thrombotic and/or haemorrhagic complications in 306 patients with Essential Thrombocythemia
Authors: Radaelli Franca , Colombi Mariangela , Calori Rossella , Zilioli Vittorio Ruggero , Bramanti Stefania , Iurlo Alessandra , Zanella Alberto 
Published: April 2007

AbstractThrombotic and haemorrhagic complications are the main causes of morbidity in Essential Thrombocythemia (ET). We investigated the clinical and laboratory characteristics associated with the occurrence of these events with the aim of identifying subgroups of patients who might benefit from anti‐aggregant and/or cytoreductive therapy. The study involved 306 consecutive ET patients (median age 58 years and median follow‐up 96 months); the investigated variables were age, gender, platelet count, previous history of thrombotic or haemorrhagic events, disease duration and cardiovascular risk factors. Forty‐six patients (15%) experienced thrombotic complications during the follow‐up: 26/64 patients with a previous history of thrombosis (40.6%) and 20/242 patients without (8.3%; p < 0.0001). Thirty‐one patients (10%) experienced major haemorrhagic complications, mainly gastrointestinal tract bleeding: 3 with and 28 without a history of haemorrhagic events (p = 0.052). When the patients with a negative history of thrombosis were stratified on the basis of the number of cardiovascular risk factors (none vs. one vs. more than one), there was a significant correlation with the occurrence of thrombotic events (p < 0.05). ET patients with a positive history of thrombosis are at high risk of thrombotic complications, and should receive cytoreductive and anti‐aggregant treatment. Asymptomatic patients with a negative thrombotic history and no cardiovascular risk factors are at low risk, and should not be treated. Patients with a negative thrombotic history and one or more cardiovascular risk factors are at intermediate risk, and should be treated with anti‐aggregant and/or cytoreductive therapy. The need for treatment should be periodically re‐evaluated. Age and platelet count, generally accepted as very important risk factors for thrombosis, did not seem in our series associated with an increased risk for thrombosis. Copyright © 2007 John Wiley & Sons, Ltd.
Fabrication and in vitro characterization of three‐dimensional organic/inorganic scaffolds by robocasting
Authors: Russias J. , Saiz E. , Deville S. , Gryn K. , Liu G. , Nalla R.K. , Tomsia A.P. 
Published: April 2007

AbstractA key issue for the fabrication of scaffolds for tissue engineering is the development of processing techniques flexible enough to produce materials with a wide spectrum of solubility (bioresorption rates) and mechanical properties matching those of calcified tissues. These techniques must also have the capability of generating adequate porosity to further serve as a framework for cell penetration, new bone formation, and subsequent remodeling. In this study we show how hybrid organic/inorganic scaffolds with controlled microstructures can be built using robotic assisted deposition at room temperature. Polylactide or polycaprolactone scaffolds with pore sizes ranging between 200–500 μm and hydroxyapatite contents up to 70 wt % were fabricated. Compressive tests revealed an anisotropic behavior of the scaffolds, strongly dependant on their chemical composition. The inclusion of an inorganic component increased their stiffness but they were not brittle and could be easily machined even for ceramic contents up to 70 wt %. The mechanical properties of hybrid scaffolds did not degrade significantly after 20 days in simulated body fluid. However, the stiffness of pure polylactide scaffolds increased drastically due to polymer densification. Scaffolds containing bioactive glasses were also printed. After 20 days in simulated body fluid they developed an apatite layer on their surface. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007.
Characteristics of novel monofilament sutures prepared by conjugate spinning
Authors: Im Jung Nam , Kim Jeong Kyung , Kim Hyun‐Kyoon , Lee Kuen Yong , Park Won Ho 
Published: April 2007

AbstractCompared with braided multifilament sutures, absorbable monofilaments are attractive suture materials as they exhibit less tissue drag and cause less tearing because of their smooth surfaces. However, monofilament sutures are less flexible and more difficult to tie a knot than multifilament ones, and their knots are more likely to loosen due to inferior knot security. Although various approaches have been reported to improve the flexibility of monofilament sutures, they still have limitations regarding poor knot security. To address this problem, we developed a novel technique to fabricate monofilament sutures by a conjugate spinning method, resulting in the formation of a sea/islands type of bicomponent monofilament suture. These sea/islands type bicomponent monofilament sutures, which can place many fine strands of a polymeric fiber within a matrix of another polymer, exhibited excellent knot security, flexibility, and low strain energy, compared with commercially available monofilament sutures. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Biochemical characterization and modulation of LH/CG—receptor during human trophoblast differentiation
Authors: Pidoux Guillaume , Gerbaud Pascale , Tsatsaris Vassilis , Marpeau Olivier , Ferreira Fatima , Meduri Geri , Guibourdenche Jean , Badet Josette , Evain‐Brion Danièle , Frendo Jean‐Louis 
Published: April 2007

AbstractDue to the key role of the human chorionic gonadotropin hormone (hCG) in placental development, the aim of this study was to characterize the human trophoblastic luteinizing hormone/chorionic gonadotropin receptor (LH/CG‐R) and to investigate its expression using the in vitro model of human cytotrophoblast differentiation into syncytiotrophoblast. We confirmed by in situ immunochemistry and in cultured cells, that LH/CG‐R is expressed in both villous cytotrophoblasts and syncytiotrophoblasts. However, LH/CG‐R expression decreased during trophoblast fusion and differentiation, while the expression of hCG and hPL (specific markers of syncytiotrophoblast formation) increased. A decrease in LH/CG‐R mRNA during trophoblast differentiation was observed by means of semi‐quantitative RT‐PCR with two sets of primers. A corresponding decrease (∼60%) in LH/CG‐R protein content was shown by Western‐blot and immunoprecipitation experiments. The amount of the mature form of LH/CG‐R, detected as a 90‐kDa band specifically binding 125I‐hCG, was lower in syncytiotrophoblasts than in cytotrophoblasts. This was confirmed by Scatchard analysis of binding data on cultured cells. Maximum binding at the cell surface decreased from 3,511 to about 929 molecules/seeded cells with a kDa of 0.4–0.5 nM. Moreover, on stimulation by recombinant hCG, the syncytiotrophoblast produced less cyclic AMP than cytotrophoblasts, indicating that LH/CG‐R expression is regulated during human villous trophoblast differentiation. J. Cell. Physiol. 212: 26–35, 2007. © 2007 Wiley‐Liss, Inc.
Regulation of plasminogen activators in human thyroid follicular cells and their relationship to differentiated function
Authors: Susarla Radhika , Watkinson John C. , Eggo Margaret C. 
Published: April 2007

AbstractHuman thyroid cells in culture take up and organify 125I when cultured in TSH (acting through cAMP) and insulin. They also secrete urokinase (uPA) and tissue‐type (tPA) plasminogen activators (5–100 IU/106cells/day). TSH and insulin both decreased secreted PA activity (PAA), uPA and tPA protein and their mRNAs. Autocrine fibroblast growth factor increased secreted PAA and inhibited thyroid cell 125I uptake. Epidermal growth factor (EGF) and the protein kinase C (PKC) activator, TPA significantly increased PAA and inhibited thyroid differentiated function, (TPA > EGF). For TPA, effects were rapid, increased PAA secretion and decreased 125I uptake being seen at 4 h whereas for EGF, a 24 h incubation was required. qRT‐PCR showed significantly increased mRNA expression of uPA with lesser effects on tPA. Aprotinin, which inhibits PAA, increased 125I uptake but did not abrogate the effects of TPA and EGF. The MEKK inhibitor, PD98059 partially reversed the effects of EGF and TPA on PAA, and largely reversed the effects of EGF but not TPA on differentiated function. PKC inhibitors bisindoylmaleimide 1, and the specific PKCβ inhibitor, LY379196 completely reversed the effects of TPA on 125I uptake and PAA whereas EGF effects were unaffected. TPA inhibited follicle formation and this effect was blocked by LY379196 but not PD98059. We conclude that in thyroid cells, MAPK activation inversely correlates with 125I uptake and directly correlates with PA expression, in contrast to the effects of cAMP. TPA effects on iodide metabolism, dissolution of follicles and uPA synthesis are mediated predominantly through PKCβ whereas EGF exerts its effects through MAPK but not PKCβ. J. Cell. Physiol. 212:643–654, 2007. © 2007 Wiley‐Liss, Inc.
Epigenetic drugs as pleiotropic agents in cancer treatment: Biomolecular aspects and clinical applications
Authors: Sigalotti Luca , Fratta Elisabetta , Coral Sandra , Cortini Enzo , Covre Alessia , Nicolay Hugues J.M. , Anzalone Lucia , Pezzani Laura , Di Giacomo Anna Maria , Fonsatti Ester , Colizzi Francesca , Altomonte Maresa , Calabrò Luana , Maio Michele 
Published: April 2007

AbstractIn the last three decades huge efforts have been made to characterize genetic defects responsible for cancer development and progression, leading to the comprehensive identification of distinct cellular pathways affected by the alteration of specific genes. Despite the undoubtable role of genetic mechanisms in triggering neoplastic cell transformation, epigenetic modifications (i.e., heritable changes of gene expression that do not derive from alterations of the nucleotide sequence of DNA) are rapidly emerging as frequent alterations that often occur in the early phases of tumorigenesis and that play an important role in tumor development and progression. Epigenetic alterations, such as modifications in DNA methylation patterns and post‐translational modifications of histone tails, behave extremely different from genetic modifications, being readily revertable by “epigenetic drugs” such as inhibitors of DNA methyl transferases and inhibitors of histone deacetylases. Since epigenetic alterations in cancer cells affect virtually all cellular pathways that have been associated to tumorigenesis, it is not surprising that epigenetic drugs display pleiotropic activities, being able to concomitantly restore the defective expression of genes involved in cell cycle control, apoptosis, cell signaling, tumor cell invasion and metastasis, angiogenesis and immune recognition. Prompted by this emerging clinical relevance of epigenetic drugs, this review will focus on the large amount of available data, deriving both from in vitro experimentations and in vivo pre‐clinical and clinical studies, which clearly indicate epigenetic drugs as effective modifiers of cancer phenotype and as positive regulators of tumor cell biology with a relevant therapeutic potential in cancer patients. J. Cell. Physiol. 212: 330–344, 2007. © 2007 Wiley‐Liss, Inc.