bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving sensitivity by large‐volume sample stacking using the electroosmotic flow pump to analyze some nonsteroidal anti‐inflammatory drugs by capillary electrophoresis in water samples
Authors: Macià Alba , Borrull Francesc , Aguilar Carme , Calull Marta 
Published: August 2003

AbstractLarge‐volume sample stacking using the electroosmotic flow (EOF) pump (LVSEP) has been used to analyze some nonsteroidal anti‐inflammatory drugs (NSAIDs) in water samples. With methanol as the run buffer solvent to suppress the EOF, sensitivity was enhanced by 80–100‐fold. The sample for the analysis of real water sample was pretreated by solid‐phase extraction (SPE). When the method was based on off‐line SPE‐LVSEP‐CE, sensitivity improved by as much as 1000 times.
Thylakoid membrane at altered metabolic state: Challenging the forgotten realms of the proteome
Authors: Rexroth Sascha , Meyer zu Tittingdorf Jürgen M. W. , Krause Frank , Dencher Norbert A. , Seelert Holger 
Published: August 2003

AbstractAnalysis of the membrane integral proteome is mainly dependent on the ability of protein separation. Blue‐native polyacrylamide gel electrophoresis (BN‐PAGE) is a technique capable of efficient membrane protein separation, so far mainly applied to the mitochondrial oxidative phosphorylation machinery. Applying BN‐PAGE to the thylakoid membranes after mild solubilization with digitonin we succeeded in displaying the response of the green algae Chlamydomonas reinhardtii to altered culture conditions. In addition, by peptide mass fingerprinting and matrix assisted laser desorption/ionization‐mass spectrometry (MALDI‐MS) extremely hydrophobic subunits of the photosystem complexes with 5–11 transmembrane helices were identified, which could not be accessed by in‐gel digestion in previous studies.
Characterization and quantitation of mixtures of alkyl ether sulfates and carboxylic acids by capillary electrophoresis with indirect photometric detection
Authors: Bernabé‐Zafón Virginia , Ortega‐Gadea Silvia , Simó‐Alfonso Ernesto F. , Ramis‐Ramos Guillermo 
Published: August 2003

AbstractThe separation, characterization, and determination of mixtures of alkyl ether sulfates (AES) and fatty acids (C10‐C16) in background electrolytes (BGEs) containing acetonitrile (ACN)‐water mixtures is addressed. Due to inhibition of the ionization of the carboxylate groups, the migration time and the resolution between the fatty acids decreased when the water content of the BGE was reduced, but efficiency and resolution between the AES oligomers improved. The migration times increased and resolution improved by substituting 5% ACN by an equivalent amount of dioxane. A complete separation of the two surfactant classes, up to the AES oligomers with 8 ethylene oxide units (EOs) with respect to C10, with excellent resolution between the AES oligomers, while preserving a satisfactory resolution between the fatty acids, was achieved with a BGE containing 5 mM trimethoxybenzoic acid, 7 mM dipentylamine, 85% ACN, 5% dioxane, and 10% water. The two surfactant classes were increasingly resolved by further reducing the water content of the BGE. Thus, C2 (acetate) was resolved from the AES oligomers up to 7 EOs using 90% ACN and 5% dioxane, but the resolution between the heavier fatty acids was poor with this BGE. Identification of the AES oligomers was eased by the excellent regularity of the successive migration times; thus, within each AES subclass or series of oligomers with the same number of carbon atoms in the alkyl chain, the migration times decreased following a mild curve as the number of EOs increased. The way how the data obtained by indirect photometry (corrected peak areas that are proportional to the molar concentrations) should be managed to avoid systematic error when the calibration curve is constructed using an AES standard with an oligomer distribution different from that of the samples is discussed and equations are given. Decyl sulfate was successfully used as internal standard. The detection limits (S/N = 3) were of ca. 2 μM for individual AES oligomers.
Casein phosphoproteome: Identification of phosphoproteins by combined mass spectrometry and two‐dimensional gel electrophoresis
Authors: Mamone Gianfranco , Caira Simonetta , Garro Giuseppina , Nicolai Adalgisa , Ferranti Pasquale , Picariello Gianluca , Malorni Antonio , Chianese Lina , Addeo Francesco 
Published: August 2003

AbstractWe report a fast and easy‐to‐use procedure that combines polyacrylamide gel electrophoresis with matrix assisted laser desorption/ionization‐time of flight‐mass spectrometry (MALDI‐TOF) and nanoelectrospray‐tandem mass spectrometry (nES‐MS/MS) analysis for the identification of casein components and defined phosphorylated sites. This methodology ensured identification of more than 30 phosphorylated proteins, five β‐, fifteen αs1‐, ten αs2‐, and four κ‐casein (CN) components, including nonallelic, differently phosphorylated, and glycosylated forms. The sugar motif covalently bound to κ‐CN was identified as chains, trisaccharide GalNAc, Gal, NeuGc, and tetrasaccharide 1GalNAc, 1Gal, 2NeuGc. Also identified was a biantennary chain made up of both chains of trisaccharide 1GalNAc, 1Gal, 1NeuGc, and tetrasaccharide 1GalNAc, 1Gal, 2NeuGc moiety on a single κ‐CN component. The phosphate group on site Ser12 of tryptic peptide 8–22 of most phosphorylated αs1‐CN (11 phosphate groups) was localized and the oligosaccharide sequence of the main tryptic glycopeptides of two κ‐CN components was determined by means of MS/MS analysis.
DNA capillary electrophoresis using poly(vinyl alcohol). I. Inner capillary coating
Authors: Moritani Tohei , Yoon Kyunghwan , Rafailovich Miriam , Chu Benjamin 
Published: August 2003

AbstractTwo new methods of inner capillary coating with poly(vinyl alcohol) (PVAL) have been investigated and evaluated by performing DNA capillary electrophoresis (CE) using PVAL as a separation medium and by measuring the electroosmotic flow (EOF) mobility. The treatment of capillaries with a silanol‐group modified PVAL (PVAL‐Si) has been found to give good coating effects for improving the resolution of DNA CE and for reducing the EOF. This coating must be effectively achieved by combining the adsorptive property of PVAL chains onto silica with the reaction between the silanol groups of PVAL‐Si and the silica surface. The adsorption of PVAL onto silica has been observed by using atomic force microscopy (AFM) for PVAL‐Si as well as for a nonmodified PVAL as a control. The coating with PVAL that links to the capillary wall surface with more hydrolytically stable bonding, –Si‐C–, has been formed by performing the Grignard reaction, followed by in‐capillary polymerization of vinyl acetate (VAc) and hydrolysis. This coating has been found to be effective for improving the resolution of DNA CE and for reducing the EOF.
DNA capillary electrophoresis using poly(vinyl alcohol). II. Separation media
Authors: Moritani Tohei , Yoon Kyunghwan , Chu Benjamin 
Published: August 2003

AbstractWe represent the first extensive study on DNA capillary electrophoresis using various poly(vinyl alcohol) (PVAL)‐related polymers as separation media. As a separation medium, PVAL homopolymer has shown poor resolutions probably due to its very strong hydrogen‐bonding characteristics, resulting in extensive self‐aggregation. On the other hand, poly(vinyl alcohol‐co‐vinyl acetate) and poly(vinyl alcohol‐co‐1‐vinyl‐2‐pyrrolidone) (PVAL‐VP), both with a degree of polymerization of ∼3.0×103, have been found to give excellent electropherograms with good resolutions for the analysis of double‐stranded (ds)DNA. PVAL‐VP, with hydrolytic stability in high and low pH regions, has also yielded fair electropherograms for single‐stranded (ss)DNA under neutral and alkaline conditions, although further investigation is essential in order to increase the resolutions necessary for DNA sequencing analysis. The separations obtained under alkaline conditions have shown significantly shorter retention times, one‐third of that for the current commercial separation media, due to the higher ionization of phosphate groups in the DNA chains.
Proteomics of snake venoms from Elapidae and Viperidae families by multidimensional chromatographic methods
Authors: Nawarak Jiraporn , Sinchaikul Supachok , Wu Chi‐Yue , Liau Ming‐Yi , Phutrakul Suree , Chen Shui‐Tein 
Published: August 2003

AbstractSnake venoms contain a large number of biologically active substances and the venom components are very useful for pharmaceutical applications. Our goal is to separate and identify components of snake venoms in ten snake species from the Elapidae and Viperidae families using multidimensional chromatographic methods. The multidimensional chromatographic methods include reversed‐phase high‐performance liquid chromatography (RP‐HPLC), sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE), lab‐on‐a‐chip, two‐dimensional electrophoresis (2‐DE), and mass spectrometry. The venoms of eight snake species demonstrated major differences in hydrophobicity, molecular weight separations, and 2‐DE protein distribution patterns. The 2‐DE images showed major differences between families, within each family and even between the same species. Venoms of the Elapidae family showed many basic proteins with a wide range of molecular weights, while venoms of the Viperidae family showed wide ranges of pI and molecular weights, especially for Trimeresurus sp. The multidimensional chromatographic methods revealed specific differences in venom proteins intra‐species as well as between species and families. We have isolated and identified proteins that may be unique for each species for further studies in the proteome of snake venoms and their potentially use in the pharmaceutical applications.
Use of an electrochemically labeled nucleotide terminator for known point mutation analysis
Authors: Brazill Sara , Hebert Nicole E. , Kuhr Werner G. 
Published: August 2003

AbstractA novel single nucleotide polymorphism (SNP) assay utilizing an electrochemically tagged chain terminator is described. The system employs the single‐base extension (SBE) technique coupled to capillary gel electrophoresis with end‐column electrochemical detection. A redox‐labeled chain terminator, ferrocene‐acycloATP, is used in the SBE reaction. When the mutation site corresponds to the labeled chain terminator, the extension product is rendered electroactive. The reaction mixture is subsequently separated by capillary gel electrophoresis and the extension product detected at the separation anode with sinusoidal voltammetry. This work demonstrates the first known SNP assay utilizing redox‐active chain terminators coupled to electrochemical detection. The methodology presented could lead to a fast, simple, and cost‐effective SNP scoring system.
Affinity enrichment of plasma membrane for proteomics analysis
Authors: Zhang Wei , Zhou Ge , Zhao Yingxin , White Michael A. , Zhao Yingming 
Published: August 2003

AbstractProteomics analysis of plasma membranes from cells exposed to different extracellular environments is potentially a powerful approach for the identification of membrane‐associated proteins responding to these environments. Preparation of high concentration plasma membrane fractions with low contamination from cellular organelles is essential for such studies. Here, we describe an affinity enrichment method, which combines cell surface biotinylation with affinity enrichment by immobilized streptavidin beads, for the isolation of plasma membranes. This method results in a 400‐fold enrichment of plasma membrane relative to endoplasmic reticulum, a major contaminant in standard plasma membrane preparations, and dramatically reduces contamination from other cellular organelles. The biotinylation reaction did not interfere with ligand‐dependent activation of receptor tyrosine kinases or G‐protein coupled receptors, suggesting cell‐surface signal transduction machinery remains functional. Membrane fractions prepared by this method should provide excellent starting materials for membrane proteomics analysis such as studies of dynamic trafficking and regulation of signaling molecules or identification of disease‐specific membrane markers.
N‐Methyl‐D‐glucamine improves the laser‐induced fluorescence capillary electrophoresis performance in the total plasma thiols measurement
Authors: Zinellu Angelo , Carru Ciriaco , Galistu Franca , Usai Maria Franca , Pes Giovanni Mario , Baggio Giovannella , Federici Giorgio , Deiana Luca 
Published: August 2003

AbstractWe describe an ultrarapid capillary electrophoresis with laser‐induced fluorescence (CE‐LIF) method for total plasma thiols measurement. Reduced thiols by 10% tri‐n‐butylphosphine (TBP) were derivatized in 10 min at room temperature with 5‐iodoacetamidofluorescein (5‐IAF) as fluorescent reagent. We show that CE‐LIF allows a baseline separation of total plasma cysteinylglycine, homocysteine, cysteine, and glutathione in less than 5 min when N‐methyl‐D‐glucamine in run buffer was added. CE was compared with high‐performance liquid chromatography (HPLC) with fluorescence detection. The Bland‐Altman test and Passing‐Bablok regression demonstrates that the results obtained by CE‐LIF and by HPLC are highly comparable. The simplified procedure of sample preparation, the short incubation and fast separation times, the high specificity, sensitivity and reproducibility, and the lower cost of analysis suggest that our proposed method can be considered valuable for the automation analysis in a routine laboratory.
Extra‐pair sires as identified by means of standardized across‐gel comparisons of multilocus DNA fingerprints
Authors: Schmoll Tim , Janzon Volker , Epplen Jörg T. , Lubjuhn Thomas 
Published: August 2003

AbstractMolecular analyses of genetic parentage in wild bird populations demonstrate that extra‐pair paternity (EPP) is common, even in socially monogamous species. After having identified extra‐pair offspring (EPO), an important step is to uncover the identity of extra‐pair sires (EPS). Studies relying on multilocus DNA fingerprinting face the problem that simple between‐gel comparisons of fingerprint banding patterns are imprecise in assigning parentage across gels. To tackle this problem, we developed a method to identify EPS by means of standardized across‐gel comparisons of multilocus DNA fingerprints and applied it in a socially monogamous bird species with high levels of EPP, the coal tit (Parus ater). Scanned DNA fingerprint gels and standard image‐editing software allowed to screen and reliably identify EPS. Overall, EPP was successfully assigned to 32 different EPS for 143 out of 210 (68.1%) EPO detected. This corresponds well to extra‐pair parentage assignment rates revealed by microsatellite‐based studies in congeneric species. Our approach proves especially useful whenever multilocus DNA fingerprints for parentage exclusion exist while microsatellite markers are not available.
A Multistage Well‐Mixed Model for Urea Removal from Industrial Wastewater
Authors: Rahimpour M.R. , Azarpour A. 
Published: August 2003

AbstractA multistage well‐mixed model for urea removal from industrial wastewater has been proposed. The model incorporates reaction rate of urea hydrolysis and takes into account the effects of backmixing on the reactor performance. The model provides temperature and concentration distribution of different components along the height of reactor. The predicted data of the model were consistent with the plant data indicating the validity of the model. The impact of different parameters on the performance of urea hydrolyzer has been examined. The result of this work showed that an increase in inlet temperature of wastewater and steam flow rate would improve the urea removal efficiency.
Site‐specific mutagenicity of stereochemically defined 1,N2‐deoxyguanosine adducts of trans‐4‐hydroxynonenal in mammalian cells
Authors: Fernandes Priscilla H. , Wang Hao , Rizzo Carmelo J. , Lloyd R. Stephen 
Published: August 2003

AbstractTrans‐4‐hydroxynonenal (HNE) is a toxic compound produced endogenously during lipid peroxidation. HNE is a potent electrophile that is reactive with both proteins and nucleic acids. HNE preferentially reacts with deoxyguanosine to form four stereoisomeric HNE‐deoxyguanosine (HNE‐dG) adducts: (6R, 8S, 11R), (6S, 8R, 11S), (6R, 8S, 11S), and (6S, 8R, 11R). These adducts were synthesized into 12‐mer oligodeoxynucleotides, inserted into a DNA shuttle vector and evaluated for the ability of each stereoisomer to induce mutagenesis when replicated through mammalian cells. The resultant mutagenicity of these adducts was related to their stereochemistry, in that two of the HNE‐dG adducts, (6R, 8S, 11R) and (6S, 8R, 11S), were significantly more mutagenic than the (6R, 8S, 11S) and (6S, 8R, 11R) HNE‐dG adducts. These data conclusively demonstrate that HNE‐derived DNA adducts can be mutagenic in mammalian cells and their ability to cause mutations is dictated by their stereochemistry. Environ. Mol. Mutagen. 42:68–74, 2003. © 2003 Wiley‐Liss, Inc.
The comet assay: Genotoxic damage or nuclear fragmentation?
Authors: Rundell Mark S. , Wagner Elizabeth D. , Plewa Michael J. 
Published: August 2003

AbstractThe single cell gel electrophoresis (SCGE) or comet assay is based on the assumption that comet images result from genotoxic damage that ultimately generate DNA single‐ or double‐strand breaks. A criticism of the assay is that some or all of the comet images may be the result of apoptosis‐mediated nuclear fragmentation. The objective of this study was to determine if mutagen‐induced DNA damage leading to strand breakage observed in the SCGE assay was repairable or was due to nonrepairable nuclear fragmentation. Chinese hamster ovary cells were treated with ethylmethanesulfonate, 2‐acetoxyacetylaminofluorene, or H2O2. These mutagens induce genetic damage by different molecular mechanisms. One group of SCGE slides was prepared immediately after treatment, while parallel treated cultures were repeatedly washed and allowed to undergo liquid holding recovery for DNA repair. It was hypothesized that cells with genotoxic damage can repair their genomic DNA, while apoptotic cells cannot reverse nuclear fragmentation. We found a significant decrease in the tail moments of nuclei from mutagen‐treated cells after 4 hr of liquid holding. However, this measurement may represent only those cells capable of repair. Apoptotic cells may continue DNA fragmentation during the recovery time and this DNA may become so diffuse that the nuclei disappear after electrophoresis. To overcome this possible artifact, images of nuclei were captured before and after alkaline electrophoresis. Constellations of nuclei were located on SCGE slides by their coordinates on the microscope stage. We found that no nuclei were lost due to apoptotic nuclear fragmentation and DNA migration. Even the so‐called “hedgehog” comet images with extreme DNA damage were not lost during liquid holding. These data support the conclusion that mutagen‐induced DNA damage is the principal cause of the damage measured in the comet assay. Environ. Mol. Mutagen. 42:61–67, 2003. © 2003 Wiley‐Liss, Inc.
Urinary excretion of 8‐hydroxy‐2‐deoxyguanosine and 1‐hydroxypyrene in coke‐oven workers
Authors: Wu Ming‐Tsang , Pan Chih‐Hong , Huang Yeou‐Lih , Tsai Perng‐Jy , Chen Chiou‐Jong , Wu Trong‐Neng 
Published: August 2003

AbstractCoke‐oven workers (COWs) are occupationally exposed to high concentrations of polycyclic aromatic hydrocarbons (PAH). Urinary 8‐hydroxy‐2‐deoxyguanosine (8‐OH‐dG) and 1‐hydroxypyrene (1‐OHP) are biological markers of oxidative DNA damage and PAH metabolism, respectively. We investigated the relationship between urinary 8‐OH‐dG and 1‐OHP in 217 Taiwanese COWs, 55 topside‐oven, and 162 sideoven workers. For topside‐oven workers, mean 8‐OH‐dG and 1‐OHP concentrations (ng/ml ± SD) were 13.8 ± 12.0 and 93.5 ± 104.4, respectively. These levels were significantly higher than those for sideoven workers: 10.2 ± 7.9 ng/ml (P = 0.04) and 19.8 ± 28.6 ng/ml (P < 0.001), respectively. Individual urinary 8‐OH‐dG concentrations were directly correlated with urinary 1‐OHP concentrations: the higher the 1‐OHP level, the higher the 8‐OH‐dG level (Spearman correlation coefficients: r = 0.43, P < 0.0001, n = 217). Multiple regression analysis indicated that a 10‐fold increase in 1‐OHP was associated with a 1.91‐fold increase in 8‐OH‐dG. Compared to no vitamin intake, intake of at least one multiple vitamin pill per week reduced 8‐OH‐dG excretion (P = 0.02). Our findings suggest that urinary 1‐OHP and 8‐OH‐dG reflect occupational PAH exposure and oxidative DNA damage in COWs. In addition, multiple vitamins may reduce oxidative stress caused by PAH exposure. Environ. Mol. Mutagen. 42:98–105, 2003. © 2003 Wiley‐Liss, Inc.
cDNA microarray gene expression profiling of hydroxyurea, paclitaxel, and p‐anisidine, genotoxic compounds with differing tumorigenicity results
Authors: Lee Michael , Kwon Jung , Kim Se Nyun , Kim Ja Eun , Koh Woo Suk , Kim Eun‐Joo , Chung Moon‐Koo , Han Sang‐Seop , Song Chang Woo 
Published: August 2003

AbstractThe potential application of toxicogenomics to predictive toxicology has been discussed widely, but the utility of the approach remains largely unproven. Using cDNA microarrays, we compared the gene expression profiles produced in mouse lymphoma cells by three genotoxic compounds, hydroxyurea (a carcinogen), p‐anisidine (a noncarcinogen), and paclitaxel (carcinogenicity unknown). To minimize the effect of biological variability and technological limitations, quadruplicate observations were made for each compound and a subset of genes yielding reproducible induction/repression was selected for comparison. A method was applied to attach normalized expression data to genes with a low false‐discovery rate (<0.1) to yield more confidence regarding differential expression. This analysis identified genotoxicity‐specific gene expression. Seven genes were consistently upregulated and 12 downregulated more than 2‐fold by the three genotoxic compounds. Using additional genes, the expression pattern induced by the genotoxic noncarcinogen, p‐anisidine, was readily distinguished from that associated with the genotoxic carcinogen, hydroxyurea. Comparison of paclitaxel‐induced expression data to data for p‐anisidine and hydroxyurea suggested that paclitaxel's profile is more similar to the genotoxic noncarcinogen. With further supporting evidence it may be possible to perform large‐scale monitoring of gene expression during drug and chemical development that can provide an early warning of potential toxicological responses. Environ. Mol. Mutagen. 42:91–97, 2003. © 2003 Wiley‐Liss, Inc.