bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct and Efficient Monitoring of Glycosyltransferase Reactions on Gold Colloidal Nanoparticles by Using Mass Spectrometry
Authors: Nagahori Noriko , Nishimura Shin‐Ichiro 
Published: June 2006

AbstractA simple and efficient assay for glycosyltransferase activity on gold colloidal nanoparticles (GCNPs) by using laser desorption/ionization time‐of‐flight mass spectrometry (LDI‐TOF MS) is demonstrated by the enzymatic synthesis of the Lewis X trisaccharide on GCNPs containing GlcNAc residues. GCNPs containing multivalent sugars were well dispersed in aqueous solution and proved to be excellent acceptor substrates for the glycosyltransferase reaction. Direct LDI‐TOF MS analysis of these GCNPs provided the ion peaks of the sugar derivatives, chemisorbed through SAu linkages onto the GCNPs, even in the presence of contaminants such as proteins and salts. Thus, it enabled the rapid and direct detection of the enzymatic reaction on the GCNPs by subjecting a small amount (0.15 μL) of the reaction mixture to MS analysis without purification. Subsequent MS/MS analyses (LDI‐LIFT‐TOF/TOF method) of the product‐carrying GCNPs enabled the structures of the sugar derivatives that had been constructed on the GCNPs by enzymatic glycosylation to be determined. A quantitative inhibition assay for glycosyltransferase by using LDI‐TOF MS analysis on the GCNPs was demonstrated by using uridine 5′‐diphosphate (UDP) as the inhibitor. This simple assay was then applied to the detection of the enzymatic activity of a crude cell extract of Escherichia coli, which produces Neisseria meningitidis β‐1,4‐galactosyltransferase (β‐1,4‐GalT). In this case, the GCNPs were roughly purified by means of ultrafiltration to remove the buffer and detergents before MS analysis. That the GCNPs are dissolved in solution in the reaction medium but are solid in the purification process is greatly advantageous for the simple and efficient detection of enzymatic activity in crude biological samples. Thus, GCNPs containing a variety of biomolecules may become a versatile and efficient tool for the rapid and direct monitoring of metabolism (metabolomics) in living cells when combined with LDI‐TOF MS analysis.
A Bridge between Pillared‐Layer and Helical Structures: A Series of Three‐Dimensional Pillared Coordination Polymers with Multiform Helical Chains
Authors: Xiao Dong‐Rong , Wang En‐Bo , An Hai‐Yan , Li Yang‐Guang , Su Zhong‐Min , Sun Chun‐Yan 
Published: June 2006

AbstractRational self‐assembly of a long V‐shaped 3,3′,4,4′‐benzophenonetetracarboxylate (bptc) ligand and metal salts in the presence of linear bidentate ligand yield a series of novel pillared helical‐layer complexes, namely, [Cu2(bptc)(bpy)2] (1), [M3(Hbptc)2(bpy)3(H2O)4]⋅2 H2O (M = Fe(2) and Ni(3)), [Co2(bptc)(bpy)(H2O)]⋅0.5 bpy (4), [Cd2(bptc)(bpy)(H2O)2]⋅H2O (5), [Mn2(bptc)(bpy)1.5(H2O)3] (6) and [M2(bptc)(bpy)0.5(H2O)5]⋅0.5 bpy (M = Mn(7), Mg(8) and Co(9), bpy=4,4′‐bipyridine). Their structures were determined by single‐crystal X‐ray diffraction analyses and further characterized by elemental analyses, IR spectra, and thermogravimetric (TG) analyses. The structure of 1 consists of two types of chiral layers, one left‐handed and the other right‐handed, which are connected by bpy pillars to generate a novel 3D open framework featuring four distinct helical chains. Compounds 2 and 3 are isostructural and feature 3D structures formed from the interconnection of arm‐shaped helical layers with bpy pillars. Compound 4 is a pillared helical double‐layer complex containing four different types of helices, among which the nine‐fold interwoven helices constructed from triple‐stranded helical motifs are unprecedented. Compound 5 exhibits a novel 3D covalent framework which features nanosized tubular channels. These channels are built from helical layers pillared by bptc ligands. The structure of 6 is constructed from {Mn(bptc)(H2O)}n2n− layers, which consist of left‐ and right‐handed helical chains, pillared by [Mn2(bpy)3(H2O)4]4+ complexes into a 3D framework. To the best of our knowledge, compounds 1–6 are the first examples of pillared helical‐layer coordination polymers. Compounds 7–9 are isostructural and exhibit interesting 2D helical double‐layer structures, which are constructed from {M(bptc)(H2O)2}n2n− ribbons cross‐linked by [M2(bpy)(H2O)6]4+ complexes. Furthermore, the 3D supramolecular structures of 7–9 are similar to the 3D structure of 6, and the 2D structure of 7 can be transformed into the 3D structure of 6 at higher reaction temperature. By inspection of the structures of 1–9, it is believed that the V‐shaped bptc ligand and V‐shaped phthalic group of the bptc ligand are important for the formation of the helical structures. The magnetic behavior of compounds 1, 2, 4, 6, and 9 was studied and indicated the existence of antiferromagnetic interactions. Moreover, compound 5 shows intense photoluminescence at room temperature.
Zn(II)‐Selective Membrane Electrode Based on Tetraazamacrocycle [Bzo2Me2Ph2(16)hexaeneN4]
Authors: Singh Ashok Kumar , Jain Ajay Kumar , Saxena Puja , Mehtab Sameena 
Published: June 2006

AbstractA PVC membrane electrode using [Bzo2Me2Ph2(16)hexaeneN4] (I) as ionophore, oleic acid as lipophilic additive and o‐nitrophenyloctyl ether as plasticizer has been investigated as Zn(II)‐selective electrode. The membrane incorporating 34.9% (w/w) PVC, 2.3% I, 4.7% OA and 58.1% o‐NPOE gave linear response over the concentration range 2.82×10−6−1.0×10−1 M with a Nernstian slope of 28.5±0.2 mV/decade of concentration with a detection limit of 2.24×10−6 M (0.146 ppm) and showed a response time of less than 10 s and could be used in pH range 2.5–8.5. High selectivity was obtained over a wide variety of metal ions. The proposed electrode was successfully used as an indicator electrode in potentiometric titration of zinc ions with EDTA and for determination of zinc in real samples.
High volume hydrodynamic injection of plasmid DNA via the hepatic artery results in a high level of gene expression in rat hepatocellular carcinoma induced by diethylnitrosamine
Authors: Tada Masaharu , Hatano Etsuro , Taura Kojiro , Nitta Takashi , Koizumi Naoki , Ikai Iwao , Shimahara Yasuyuki 
Published: June 2006

AbstractBackgroundHydrodynamic injection of naked plasmid DNA (pDNA) via the tail vein is a safe and effective method of gene transfer to the liver. However, successful gene transfer has yet to be shown for hepatocellular carcinoma (HCC); therefore, we investigated the feasibility and efficacy of hydrodynamic injection via the tail vein and hepatic artery in a diethylnitrosamine (DEN)‐induced HCC model in rats.MethodsHCC was induced in Sprague‐Dawley rats by 100 ppm DEN in drinking water. pCMV‐SPORT‐β‐galactosidase (β‐gal, 400 µg) was injected (i) via the tail vein in a volume of 0.1 ml/g in 30 s or (ii) via the hepatic artery in a volume of 5 or 10 ml at 1 ml/s, either with or without temporary occlusion of the inferior vena cava (IVC) and portal vein (PV). The liver was harvested 24 h after administration, and β‐gal expression was evaluated with X‐gal staining and measurement of enzymatic activity in tissue homogenates.ResultsHydrodynamic injection via the tail vein achieved transgene expression only in non‐cancerous tissue (tumor: 0.16 ± 0.04%, non‐tumor: 5.07 ± 1.66%). Hydrodynamic injection via the hepatic artery was tolerated, but failed to produce efficient transgene expression in tumor and non‐tumor cells. On the other hand, concomitant use of temporary IVC/PV occlusion with hydrodynamic injection via the hepatic artery dramatically increased transgene expression in cancer cells, but tumor‐selective gene transfer was not achieved with this procedure (tumor: 7.38 ± 3.66%, non‐tumor: 7.77 ± 1.06%).ConclusionsHigh‐volume hydrodynamic injection of a pDNA solution via the hepatic artery with IVC/PV occlusion achieved a high level of gene expression in a HCC rat model. This gene transfer technique may have potential in clinical gene therapy for HCC. Copyright © 2006 John Wiley & Sons, Ltd.
Discrimination of wheat varieties by simultaneous measurements of oxygen consumption and consistency of flour dough during mixing
Authors: Levavasseur Loïc , Rakotozafy Lalatiana , Manceau Elise , Louarme Loïc , Robert Hugues , Baret Jean‐Luc , Potus Jacques , Nicolas Jacques 
Published: June 2006

AbstractUsing an instrumented mixing reactor, oxygen consumption and torque evolution were recorded during the mixing of wheat flour doughs from eight pure French wheat varieties harvested in 2002 and 2003. Wheat flours were also characterised by biochemical analyses including lipoxygenase (LOX) activity assay, free polyunsaturated fatty acid (PUFA) content, glutathione and ferulic acid contents, results of alveograph and farinograph tests and breadmaking performances. Some parameters defined from the obtained torque curves, equivalent to consistency curves, were correlated with alveograph and farinograph data. The importance of LOX activity levels and free PUFA content to explain the oxygen consumption during mixing is confirmed. In addition to the characteristics of the oxygen consumption curves, the extent to which the consistency curve parameters are able to differentiate among doughs made with flours from different wheat varieties is considered. Copyright © 2006 Society of Chemical Industry
Anthocyanin fingerprint of grapes: environmental and genetic variations
Authors: Ortega‐Regules Ana , Romero‐Cascales Inmaculada , López‐Roca Jose M , Ros‐García Jose M , Gómez‐Plaza Encarna 
Published: June 2006

AbstractThe anthocyanin content and fingerprint of four different Vitis vinifera L. varieties (Cabernet Sauvignon, Merlot, Syrah and Monastrell), the last grown in two different locations, were studied during three growing seasons to determine how seasonal conditions and location affect the content of berry anthocyanins and their relative percentages. Important differences in the content of anthocyanins were detected among varieties—Monastrell grapes from one of the locations presenting the highest anthocyanin content—when expressed as µg g−1 of skin. However, due to the large berry size of Monastrell grapes, when the results were expressed as mg kg−1 of berry, Cabernet Sauvignon and Syrah grapes presented the highest concentration. Significant differences were found as regards growing season, the concentration of anthocyanins being lowest in 2003, the warmest year. As regards the relative percentage of the different anthocyanins, substantial differences were found between varieties, but again, the results were also influenced by the year under study. When the percentages of anthocyanins were used as variables in a discriminant analysis, a 100% correct classification of the four different varieties was obtained. Moreover, to check the suitability of this tool for classifying varieties, data referring to the anthocyanin percentages of the four varieties grown in very different agroecological conditions and at different ripening stages were tested with the model we have built, 89% of correct classification being achieved. Copyright © 2006 Society of Chemical Industry
Analysis of secondary metabolites from eschscholtzia californica by high‐performance liquid chromatography
Authors: Klvana Maya , Chen Jingkui , Lépine François , Legros Robert , Jolicoeur Mario 
Published: June 2006

AbstractA rapid and precise analytical HPLC method has been developed for screening the major benzophenanthridine alkaloids produced by cell cultures of Eschscholtzia californica, namely, sanguinarine, chelirubine, macarpine, chelerythrine and chelilutine. Separation was achieved on a C18 reversed‐phase column with gradient elution using acetonitrile and 50 mm phosphoric acid. Detection was performed by both fluorescence (λex 330 nm, λem 570 nm) and photodiode array, leading to good selectivity and precision in determining peak purity. A simple and quick sample preparation protocol was elaborated involving a methanolic extraction for the measurement of intracellular concentrations of the alkaloids and a solid phase extraction for their quantification in culture medium. Owing to the non‐availability of commercially standards, a method for the purification of chelirubine, macarpine and chelilutine by semi‐preparative HPLC was developed. Coupled together, the isolation method and the analytical method were highly reliable for screening the alkaloids of interest produced by E. californica. Copyright © 2006 John Wiley & Sons, Ltd.
Headspace–solid‐phase microextraction fast GC in combination with principal component analysis as a tool to classify different chemotypes of chamomile flower‐heads (Matricaria recutita L.)
Authors: Rubiolo Patrizia , Belliardo Flavio , Cordero Chiara , Liberto Erica , Sgorbini Barbara , Bicchi Carlo 
Published: June 2006

AbstractHeadspace–solid‐phase microextraction gas chromatography‐principal component analysis (HS‐SPME GC‐PCA) is proposed as a complementary or alternative method to essential oil (EO) GC‐PCA in order to discriminate between flower‐heads of chamomile of different chemotypes. Ninety‐two EOs and the headspaces sampled by HS‐SPME of the corresponding chamomile flower‐heads were examined by conventional GC and fast GC (F‐GC) and the results submitted to statistical analysis by PCA. HS‐SPME F‐GC‐PCA showed itself to be a rapid technique by which to distinguish chamomile flower‐head chemotypes a produced results in agreement with the accepted EO classification. Using this method, the analysis time was reduced from at least 4.5 h with EO conventional GC to less than 1 h with HS‐SPME F‐GC. This approach can thus successfully be used as an analytical decision maker in order to reduce the number of time‐consuming EO conventional GC analyses by limiting them to those samples that cannot unequivocally be classified. The EO conventional GC and HS‐SPME F‐GC results of PCA were very uniform, but they did not provide quantitative correlations between the components as determined by the two methods. A different statistical approach and a larger number of samples will be needed in order to correlate components in the headspace sampled by SPME and those in the corresponding EO quantitatively through a function. Copyright © 2006 John Wiley & Sons, Ltd.
Retracted: Effect of Meso‐dihydroguaiaretic acid from Machilus thunbergii Sieb et Zucc on MMP‐1 expression in heat shock‐induced cultured primary human fibroblasts
Authors: Moon Hyungin , Jung Jae‐Chul 
Published: June 2006

AbstractThis article has been retracted. See retraction notice DOI: 10.1002/ptr.2151Ethanol and aqueous extracts of Machilus thunbergii Sieb et Zucc (Lauraceae) used traditionally for the treatment of a variety of diseases were screened in vitro for MMP‐1 inhibitory actions. Meso‐dihydroguaiaretic acid (MDGA) from the stem bark of M. thunbergii showed a significant inhibition of matrix metalloproteinase (MMP)‐1 in primary human fibroblasts by heat shock‐induced. This study investigated the effect of MDGA isolated from M. thunbergii on heat shock‐induced premature skin aging. MDGA reduced the expression of MMP‐1 at the protein level in a dose‐dependent manner in heat shock‐induced cultured primary human fibroblasts. Taken together, these results show that MDGA can prevent the harmful effects of heat (and/or IR) that lead to skin aging. Copyright © 2006 John Wiley & Sons, Ltd.
QSTR with Extended Topochemical Atom (ETA) Indices 8.aQSAR for the inhibition of substituted phenols on germination rate ofCucumis sativususing chemometric tools
Authors: Roy Kunal , Ghosh Gopinath 
Published: June 2006

AbstractQuantitative structure‐toxicity relationship (QSTR) study has proved to be a valuable approach in ecotoxicity estimations of acute and chronic toxicity to various organisms, and in fate estimations of physical/chemical properties, degradation, and bioconcentration. In this background, we have modeled the inhibition of 41 substituted phenols on germination rate ofCucumis sativuswith extended topochemical atom (ETA) indices using different chemometric tools and compared the ETA relations with non‐ETA models derived from different topological indices (WienerW, BalabanJ, HosoyaZ, Zagreb, molecular connectivity indices, E‐state indices and kappa shape indices) and physicochemical parameters (AlogP98, MolRef, H_bond_acceptor, H_bond_donor, MW,logKowand Elumo). Different statistical tools used in this communication are stepwise regression analysis, multiple linear regression with factor analysis as the preprocessing step for variable selection (FA‐MLR), multiple linear regression with genetic function approximation (GFA‐MLR), partial least squares regression with factor analysis as the preprocessing step for variable selection (FA‐PLS), genetic partial least squares (G/PLS) and principal component regression analysis (PCRA). The results show that the best statistical quality along with prediction statistics with ETA descriptors is found in case of GFA‐MLR equation. In case of non‐ETA descriptors, the best equation is obtained from PCRA considering both equation statistics and predictive ability. When combined descriptors were considered, FA‐PLS gave the best equation. The best ETA equation (GFA‐MLR) has better leave‐one‐outQ2value than the best non‐ETA equation (PCRA). The results suggest that the ETA descriptors are sufficiently rich in chemical information to encode the structural features contributing significantly to the comparative inhibition activity of substituted phenols on germination rate ofCucumis sativus.
Liquid chromatography/tandem mass spectrometry method for simultaneous determination of risperidone and its active metabolite 9‐hydroxyrisperidone in human plasma
Authors: Bhatt Jignesh , Subbaiah Gunta , Singh Sadhana 
Published: June 2006

AbstractA rapid and sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method has been developed and validated for simultaneous quantification of risperidone (RSP) and its active metabolite 9‐hydroxyrisperidone (9‐OH‐RSP) in human plasma. The analytes were extracted from human plasma by using the protein precipitation extraction technique. Methyl risperidone was used as internal standard for RSP and 9‐OH‐RSP. A Betasil C18 column provided chromatographic separation of analytes followed by detection with mass spectrometry. The mass transition ion‐pair was followed as m/z 411.28 → 191.15 for RSP and m/z 427.30 → 207.10 for 9‐OH‐RSP. The method involves a simple extraction, isocratic chromatography conditions and mass spectrometric detection that enable detection at sub‐nanogram levels. The proposed method has been validated with a linear range of 0.10–15.0 ng/mL for RSP and 9‐OH‐RSP. The intrarun and interrun precision and accuracy values were within 15%. The overall recoveries for RSP and 9‐OH‐RSP were 82.1% and 83.2%, respectively. The total analysis time was as low as 3.0 min only. The developed method was applied for the determination of the pharmacokinetic parameters of RSP and 9‐OH‐RSP following a single oral administration of a 1 mg RSP tablet in 24 healthy male volunteers. Copyright © 2006 John Wiley & Sons, Ltd.
Study of polybrominated diphenyl ethers using both positive and negative atmospheric pressure photoionization and tandem mass spectrometry
Authors: Riu Anne , Zalko Daniel , Debrauwer Laurent 
Published: June 2006

AbstractAtmospheric pressure photoionization (APPI) was assessed for the mass spectrometric analysis of polybromodiphenyl ethers (PBDEs) on the basis of a set of 17 standard compounds. Positive and negative ionization modes were both investigated. M+. ions were formed under positive ion conditions whereas the negative ion mode yielded [M–Br+O]− ions. The behavior of these APPI‐produced ions towards collisional activation was studied using an ion trap mass spectrometer. In positive ion mode, the loss of Br2 was one of the major fragmentation pathways, and was favored for ortho‐substituted PBDEs. Conversely, the loss of COBr. occurred only for non‐ortho‐substituted congeners. The collisional excitation of [M–Br+O]− ions in the ion trap also led to the loss of Br2, to the elimination of HBr, and to the formation of product ions by cleavage of the ether bond. The formation of para‐quinone radical anions was observed for PBDEs ranging from penta‐ to hepta‐congeners, whereas brominated aromatic carbanions were formed preferentially for the most brominated PBDEs studied in this work (hepta‐ or deca‐BDEs). M+. ions did not undergo this fragmentation process. Copyright © 2006 John Wiley & Sons, Ltd.
Determination of gabapentin in human plasma using hydrophilic interaction liquid chromatography with tandem mass spectrometry
Authors: Ji Hye Young , Jeong Dong Won , Kim Young Hoon , Kim Hui‐Hyun , Yoon Yoo‐Seok , Lee Kang Choon , Lee Hye Suk 
Published: June 2006

AbstractA rapid, sensitive and selective method for the determination of gabapentin in human plasma was developed using hydrophilic interaction liquid chromatography/tandem mass spectrometry (HILIC/MS/MS). The devised method involved protein precipitation with acetonitrile followed by separation on an Atlantis HILIC silica column using an acetonitrile/ammonium formate mobile phase (100 mM, pH 3.0) (85:15, v/v). Analytes were detected using an electrospray ionization mass spectrometer in the multiple‐reaction monitoring mode. The standard curve was linear (r = 1.000) over the concentration range of 50.0–10000 ng/mL. The lower limit of quantification for gabapentin was 50.0 ng/mL (ca. 20 pg gabapentin) using a 10‐µL plasma sample. The coefficients of variation and relative errors for intra‐ and inter‐assay at four QC levels (i.e., 50.0, 125, 750, and 7500 ng/mL) were 4.7 to 9.4% and −4.1 to 1.6%, respectively. Absolute and relative matrix effects for gabapentin and metformin were practically absent. Gabapentin and metformin recoveries were 98.5% and 99.0%, respectively. This method was successfully applied to a bioequivalence study of gabapentin in humans. Copyright © 2006 John Wiley & Sons, Ltd.
Cost of depression: effect of adherence and treatment response
Authors: von Knorring L. , Åkerblad A.-C. , Bengtsson F. , Carlsson Å. , Ekselius L. 
Published: June 2006

AbstractObjectives:The purpose of the present study has been to assess the societal cost of major depression and the distribution into different cost components. The impact of adherence and treatment response was also explored.Method:Data were collected from a randomized controlled trial of patients with major depressive disorder who were treated in a naturalistic primary care setting. Resource use and quality of life were followed during the two-year trial.Results:The mean total cost per patient during two years was KSEK 363 (EUR 38 953). Indirect costs were the most important component (87%), whereas the cost of drugs was minor (4.5%). No significant differences in costs or quality of life between treatment arms or between adherent and non-adherent patients were demonstrated. However, treatment responders had 39% lower total costs per patient and experienced a larger increase in quality of life compared to non-responders.Conclusions:Major depression has high costs for society, primarily due to indirect costs. Treatment responders have considerably lower costs per patient and higher quality of life than non-responders. This indicates that measures to increase response rates are also important from an economic perspective.