bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recent advances in nonaqueous capillary electrophoresis
Authors: Riekkola Marja‐Liisa 
Published: December 2002

AbstractNonaqueous capillary electrophoresis is undergoing rapid development. The scope of the investigations has clearly expanded, covering both basic studies and analytical applications. This review provides a comprehensive overview at the current status of the technique. Special attention is given to theoretical, methodological, and technical challenges, and the achievements of capillary electrophoresis in nonaqueous media are demonstrated with reference to recent applications.
Recent advances and trends in capillary electrophoresis of inorganic ions
Authors: Timerbaev Andrei R. 
Published: December 2002

AbstractCapillary electrophoresis (CE) continues its invasion into the domain of inorganic analysis. This review summarizes the progress and significant developments of CE of inorganic ions over the first two years of the new century. As manifested by the substantial number of published articles, this field is still witnessing a growing activity of many separation scientists. To provide an in‐depth treatment of fundamental and methodological aspects of inorganic ion analysis by CE, an extensive fraction of the relevant literature is covered whereas only most innovative application reports are briefly considered. Most of the recent advancements have focused on CE system modernization designed to improve a limited detection sensitivity, which still remains a major obstacle to overcome in order to ensure the method's wider practical acceptance. Attention is also given to how and in which directions the future research could be performed to implement CE in routine inorganic analysis.
Micellar electrokinetic chromatography: Current developments and future
Authors: Molina Manuel , Silva Manuel 
Published: December 2002

AbstractThis review highlights recent methodological and instrumental advances in micellar electrokinetic chromatography (MEKC). Enhancements in sensitivity and selectivity of the technique through the use of on‐line preconcentration approaches (stacking and sweeping) and nonconventional pseudostationary phases, namely nonionic and zwitterionic surfactants, mixed micelles and polymers, are discussed in detail. Laser‐induced fluorescence and mass spectrometry, as alternatives to UV‐absorption detection, have been covered to evaluate their advantages and limitations when applied to analysis in an MEKC format. Some thoughts on future directions in this area such as in‐capillary reactions, coated capillaries and MEKC on microchips are also presented.
Recent progress in adsorbed stationary phases for capillary electrochromatography
Authors: Liu Zhen , Wu Ren'an , Zou Hanfa 
Published: December 2002

AbstractThis review surveys the recent progress in the adsorbed stationary phases for capillary electrochromatography (CEC). Adsorption‐based methods for preparation of stationary phase are novel approaches in CEC, which allow rapid and facile preparing stationary phases with desirable selectivity onto an open‐tubular fused‐silica capillary, a bare‐silica or ion‐exchange packed column or a monolithic silica or polymer column. A variety of adsorbing agents have been developed as adsorbed stationary phases, including ionic long‐chain surfactant, protein, peptide, amino acid, charged cyclodextrin (CD), basic compound, aliphatic ionene, and ion‐exchange latex particle. The adsorbed stationary phases have been applied to separation of neutral, basic and acidic organic compounds, inorganic anions and enantiomers. They have also been applied to on‐line sample concentration, fast separation and study of the competitive binding of enantiomers with protein.
Enantiomer migration order in chiral capillary electrophoresis
Authors: Chankvetadze Bezhan 
Published: December 2002

AbstractEnantiomer migration order (EMO) in chiral capillary electrophoresis (CE) represents a challenging issue, referred to in less than 20% of the articles on CE enantioseparations. This review articie will (i) illustrate the actuality of the topic, (ii) discuss some technical problems related to EMO in CE enantioseparations, (iii) examine the principal differences between CE and other separation techniques from the viewpoint of enantiomer elution order, (iv) demonstrate the potential for a designed reversal of EMO in CE, and (v) emphasize the importance of studying EMO for better understanding of chiral CE as well as its more effective application. Along with CE, the results obtained by other instrumental techniques such as nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), X‐ray crystallography, as well as molecular modeling calculations will be shortly discussed. Rather than referring to all published examples of the opposite migration order of enantiomers in CE, the emphasis will be on general aspects. Recently, the reversal of the EMO was described in detail in a book chapter (Chankvetadze, B., Capillary Electrophoresis in Chiral Analysis, Wiley & Sons, Chichester, UK 1997, Chapter 12) as well as in three review articles [1, 3, 4].
Chiral capillary electrophoresis‐mass spectrometry: Modes and applications
Authors: Shamsi Shahab A. 
Published: December 2002

AbstractA review is presented to highlight several approaches for coupling capillary electrophoresis (CE) and electrospray ionization‐mass spectrometry (ESI‐MS) for analysis of chiral compounds. A short discussion of commercially available CE‐MS instruments and interface design is followed by a detail review on various modes of chiral CE‐MS. In general, for each CE‐MS mode, the capabilities, applications and limitations for chiral analysis have been pointed out. The first mode, chiral capillary zone electrophoresis‐mass spectrometry (CZE‐MS) in which neutral derivatized cyclodextrins (CDs) are used is possible using either column coupling with voltage switching or a partial‐filling technique (PFT). However, some applications of direct coupling of CZE‐MS mode are also reported. The second mode is a chiral electrokinetic chromatography‐mass spectrometry (EKC‐MS) in which a charged chiral selector such as a sulfated β‐CD or a vancomycin could be conveniently employed. This is because these chiral selectors have a significantly higher countercurrent electrophoretic mobility which prevents the entrance of these selectors into the mass spectrometer. The combination of counter‐migration and PFT demonstrates that this synergism could be successfully applied to chiral analysis of a broader range of compounds. It is well‐known that the on‐line coupling of micellar electrokinetic chromatography to mass spectrometry (MEKC‐MS) is problematic because the high surface activity and nonvolatile nature of conventional surfactant molecules lower the electrospray ionization efficiency. However, a recent report demonstrates that this hyphenation is now possible with the use of molecular micelles. Various MEKC‐ESI‐MS parameters that can be used to optimize both chiral resolution and ESI response are discussed. Finally, two recent examples that demonstrate the feasibility of using either open‐tubular or packed chiral CEC with MS are reviewed. This survey will attempt to cover the state‐of‐the‐art on various modes of CE‐MS from 1998 up to 2002.
Evaluation of a potential epigenetic biomarker by quantitative methyl‐single nucleotide polymorphism analysis
Authors: Uhlmann Karen , Brinckmann Anja , Toliat Mohammad R. , Ritter Heide , Nürnberg Peter 
Published: December 2002

AbstractTumorigenesis is characterized by alterations of methylation profiles including loss and gain of 5‐methylcytosine. Recently, we identified a single CpG, which seemed to be consistently hypomethylated in pilocytic astrocytomas but not in other gliomas. To evaluate its applicability as a biomarker, we examined its methylation status in a large panel of gliomas (n = 97). Methylation‐dependent DNA sequence variation may be considered a kind of single nucleotide polymorphism (methylSNP). MethylSNPs can be easily converted into common SNPs of the C/T type by sodium bisulfite treatment of the DNA and afterwards subjected to conventional SNP typing. We adapted SnaPshot™ and Pyrosequencing™ to determine the methylation of our test CpG in a quantitative manner. The adapted methods, called SNaPmeth and PyroMeth, respectively, gave nearly identical results, however data obtained with PyroMeth showed less scattering. Furthermore, the integrated software for allele frequency determination from Pyrosequencing could be used directly for data analysis while SnaPmeth data had to be exported and processed manually. Although data did not confirm our previous result of a preferential hypomethylation of the tested CpG in pilocytic astrocytomas, we consider quantitative methylSNP analysis by SNaPmeth or PyroMeth a favorable alternative to existing high‐throughput methylation assays. It combines single CpG analysis with accurate quantitation and is amenable to high throughput.
Complete mitochondrial DNA sequence of a tadpole shrimp (Triops cancriformis) and analysis of museum samples
Authors: Umetsu Kazuo , Iwabuchi Naruki , Yuasa Isao , Saitou Naruya , Clark Paul F. , Boxshall Geoff , Osawa Motoki , Igarashi Keiji 
Published: December 2002

AbstractThe complete mitochondrial DNA (mtNDA) of the tadpole shrimp Triops cancriformis was sequenced. The sequence consisted of 15 101 bp with an A+T content of 69%. Its gene arrangement was identical with those sequences of the water flea (Daphnia pulex) and giant tiger prawn (Penaeus monodon), whereas it differed from that of the brine shrimp (Artemia franciscana) in the arrangement of its genes for tRNAs. Phylogenetic analysis revealed T. cancriformis to be more closely related to the water flea than to the brine shrimp and giant tiger prawn. We also compared the 16S rRNA sequences of five formalin‐fixed tadpole shrimps that had been collected in five different locations and stored in a museum. The sequence divergence was in the range of 0–1.51%, suggesting that those samples were closely related to each other.
BRCA1 mutation screening using restriction endonuclase fingerprinting‐single‐strand conformation polymorphism in an automated capillary electrophoresis system
Authors: Kringen Pedro , Egedal Sidsel , Pedersen Jan C. , Harbitz Thorstein B. , Tveit Kjell M. , Berg Kåre , Børresen‐Dale Anne‐Lise , Andersen Tone I. 
Published: December 2002

AbstractEfficient mutation scanning techniques are needed for the rapid detection of novel disease‐associated mutations and rare‐sequence variants of putative importance. The large size of the breast cancer 1 gene (BRCA1) and the many mutations found throughout its entire coding sequence make screening for mutations in this gene particularly challenging. We have developed a method for screening exon 11 of the BRCA1 gene based on restriction enzyme digestion of fluorescence‐labeled polymerase chain reaction (PCR) products followed by single‐strand conformation polymorphism (SSCP) using an automated capillary electrophoresis system, denoted capillary restriction endonuclease fingerprinting (REF)‐SSCP electrophoresis. Using this strategy on a control set of samples, we were able to detect 17 of 18 known sequence alterations. The method was then applied to screen 73 Norwegian females with family histories of breast and/or ovarian cancer. A total of 172 sequence alterations were detected, including substitutions, insertions, and deletions. One novel substitution of unknown function was identified. Sequencing of all samples negative in the capillary REF‐SSCP system gave no additional mutations confirming the high sensitivity of the described methodology. Capillary REF‐SSCP electrophoresis appeared as a technically convenient technique, requiring amplification of fewer PCR fragments than traditional SSCP. The novel strategy allows high‐throughput mutation scanning without radioactive labeling and polyacrylamide gel electrophoresis (PAGE).
Proteomic analysis of rat brain tissue: Comparison of protocols for two‐dimensional gel electrophoresis analysis based on different solubilizing agents
Authors: Carboni Lucia , Piubelli Chiara , Righetti Pier Giorgio , Jansson Birger , Domenici Enrico 
Published: December 2002

AbstractThe present study reports a comparison of recently described solubilizing methods, to set up a simple protocol for obtaining two‐dimensional (2‐D) gel electrophoresis maps of brain tissue. Different protocols were used for preparing rat brain homogenates and the resulting maps were compared by image analysis. Three different detergents, two delipidation methods, and introduction of a fractionation step based on different protein solubility in surfactants, were evaluated. When using efficient zwitterionic detergents (3‐[(3‐cholamidopropyl)dimethylamino]‐1‐propanesulfonate, CHAPS; amidosulfobetaine 14, ASB‐14), the patterns obtained by direct loading of total extracts were qualitatively overlapping with patterns obtained from fractionated samples. In contrast, a weaker nonionic agent (Nonidet P‐40, NP‐40) produced a different protein pattern in the collected fractions. Delipidation did not improve the results for all the different extraction methods. Immunoblots performed with antibodies recognizing cytosolic and membrane‐spanning proteins, which were detected as nondegraded spots, showed that membrane proteins with intermediate molecular mass could be recovered. We suggest, as a simple and efficient method for preparing rat brain maps, the homogenization in a solution containing an efficient zwitterionic surfactant, which allows to solubilize cytosolic and membrane proteins in a single step. Alternatively, a fractionation can be carried out on samples homogenized by a weak solubilizing agent, a more labor‐intensive effort resulting in a larger number of proteins on two maps.
Proteome analysis of human liver tumor tissue by two‐dimensional gel electrophoresis and matrixassisted laser desorption/ionization‐mass spectrometry for identification of disease‐related proteins
Authors: Kim Jina , Kim Soon H. , Lee Seung U. , Ha Geun H. , Kang Deok G. , Ha Na‐Young , Ahn Jin S. , Cho Hey Y. , Kang Sung‐Jo , Lee Young‐Joon , Hong Soon C. , Ha Woo S. , Bae Jong M. , Lee Chang‐Won , Kim Jae W. 
Published: December 2002

AbstractHepatocellular carcinoma (HCC) is a common malignancy worldwide and is a leading cause of death. To contribute to the development and improvement of molecular markers for diagnostics and prognostics and of therapeutic targets for the disease, we have largely expanded the currently available human liver tissue maps and studied the differential expression of proteins in normal and cancer tissues. Reference two‐dimensional electrophoresis (2‐DE) maps of human liver tumor tissue include labeled 2‐DE images for total homogenate and soluble fraction separated on pH 3–10 gels, and also images for soluble fraction separated on pH 4–7 and pH 6–9 gels for a more detailed map. Proteins were separated in the first dimension by isoelectric focusing on immobilized pH gradient (IPG) strips, and by 7.5–17.5% gradient sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) gels in the second dimension. Protein identification was done by peptide mass fingerprinting with delayed extraction‐matrix assisted laser desorption/ionization‐time of flight‐mass spectrometry (DE‐MALDI‐TOF‐MS). In total, 212 protein spots (117 spots in pH 4–7 map and 95 spots in pH 6–9) corresponding to 127 different polypeptide chains were identified. In the next step, we analyzed the differential protein expression of liver tumor samples, to find out candidates for liver cancer‐associated proteins. Matched pairs of tissues from 11 liver cancer patients were analyzed for their 2‐DE profiles. Protein expression was comparatively analyzed by use of image analysis software. Proteins whose expression levels were different by more than three‐fold in at least 30% (four) of the patients were further analyzed. Numbers of protein spots overexpressed or underexpressed in tumor tissues as compared with nontumorous regions were 9 and 28, respectively. Among these 37 spots, 1 overexpressed and 15 underexpressed spots, corresponding to 11 proteins, were identified. The physiological significance of the differential expressions is discussed.
Comparison of ethanol‐soluble proteins from different rye (Secale cereale) varieties by two‐dimensional electrophoresis
Authors: Radzikowski Louise , Nešić Ljiljana , Hansen Hanne Boskov , Jacobsen Susanne , Søndergaard Ib 
Published: December 2002

AbstractThe major storage proteins from six rye varieties, grown under the same conditions in 1997 and 1998 in Rønhave, Denmark, were analyzed by two‐dimensional (2‐D) polyacrylamide gel electrophoresis. The proteins were extracted from ground rye kernels with 70% ethanol and separated by 2‐D electrophoresis. The gels were scanned, compared using ImageMaster® software and the data sets were analyzed by principal component analysis (PCA) using THE UNSCRAMBLER software. Afterwards MATLAB was used to make a cluster analysis of the varieties based on PCA. The analysis of the gels showed, that the protein patterns (number of different proteins and their isoelectric points and molecular weights) from the six rye varieties were different. Based on the presence of unique cultivar‐specific spots it was possible to differentiate between all six varieties if the two harvest years were investigated separately. When the results were combined from the two years five varieties could be differentiated. The results from the PCA confirmed the finding of the unique spots and cluster analysis was made in order to illustrate the results. The combination of the results from 2‐D electrophoresis and other grain characteristics showed that one protein spot was located close to the parameters bread volume and bread height.
Gerbils of a seizure‐sensitive strain have a mitochondrial inner membrane protein with different isoelectric points from those of a seizure‐resistant strain
Authors: Omori Akira , Ichinose Sachiyo , Kitajima Satoko , Shimotohno Kumiko W. , Murashima Yoshiya L. , Shimotohno Kunitada , Seto‐Ohshima Akiko 
Published: December 2002

AbstractThe distribution of proteins in the cerebral cortex of a seizure‐sensitive (SS) strain of gerbil and its seizure‐resistant (SR) counterpart was profiled using two‐dimensional gel electrophoresis. A series of proteins of similar molecular weight (around 83 kDa) showed small but consistent differences in their isoelectric point (pI) with indistinguishable profiles of distribution between the two strains. Amino acid sequences of peptides produced by limited proteolysis of each protein in the spots from the strains were identical or highly homologous to those of mitofilin, a mitochondrial inner membrane protein (IMMT) in humans. Analysis of cDNA sequences revealed the proteins of these spots to be gerbil mitofilin‐like proteins (gIMMT), with a few base substitutions between SS and SR strains, in particular within a region near a putative transmembrane domain that is highly conserved in humans and gerbils. The amino acid at the site was acidic, Glu in humans and Asp in the strain SR of gerbil and a neutral, Asn in strain SS. In addition to these base substitutions, production of multiple species of mRNA for gIMMT by alternative splicing was observed.
Podocyte‐specific expression of cre recombinase in transgenic mice
Authors: Moeller Marcus J. , Sanden Silja K. , Soofi Abdulsalam , Wiggins Roger C. , Holzman Lawrence B. 
Published: December 2002

AbstractSummary: We report a transgenic mouse line that expresses Cre recombinase exclusively in podocytes. Twenty‐ four transgenic founders were generated in which Cre recombinase was placed under the regulation of a 2.5‐kb fragment of the human NPHS2 promoter. Previously, this fragment was shown to drive beta‐galactosidase (β‐gal) expression exclusively in podocytes of transgenic mice. For analysis, founder mice were bred with ROSA26 mice, a reporter line that expresses β‐gal in cells that undergo Cre recombination. Eight of 24 founder lines were found to express β‐gal exclusively in the kidney. Histological analysis of the kidneys showed that β‐gal expression was confined to podocytes. Cre recombination occurred during the capillary loop stage in glomerular development. No evidence for Cre recombination was detected in any of 14 other tissues examined. genesis 35:39–42, 2003. © 2002 Wiley‐Liss, Inc.
Introduction of cell markers into germ layer tissues of the mouse gastrula by whole embryo electroporation
Authors: Davidson Bruce P. , Tsang Tania E. , Khoo Poh‐Lynn , Gad Jacqueline M. , Tam Patrick P.L. 
Published: December 2002

AbstractSummary: We have optimized the technique of electroporation for introducing genetic markers into cells of the gastrulating mouse embryo to follow cell fates, tissue movement, and lineage differentiation. Using a plate‐needle electrode combination and specific route of plasmid delivery, labeling could be targeted to discrete regions of the epiblast or the endoderm of the late gastrula. Among the various types of fluorescent and chromogenic reporter constructs tested, those driven by CMV promoter are efficient and strong expression can be detected as soon as 2–3 h after electroporation. The efficacy of marking cell lineages by CRE‐mediated activation of reporters proved to be inefficient for tracking cell lineages due to an obligatory 8–9‐h lag from the electroporation of constructs to the expression of reporter. This significant time lag also raises concern of the temporal precision at which tissue‐ or stage‐specific knock‐out or activation of genetic activity may be achieved by the Cre‐loxP mechanism. genesis 35:57–62, 2003. © 2002 Wiley‐Liss, Inc.
How isotopic fractionation of snowmelt affects hydrograph separation
Authors: Taylor Susan , Feng Xiahong , Williams Mark , McNamara James 
Published: December 2002

AbstractWe present the isotopic composition of meltwater samples from four seasonal snowpacks: a warm, maritime snowpack in California; a temperate continental snowpack in Vermont; a cold continental snowpack in Colorado; and an Arctic snowpack in Alaska. Despite the very different climate conditions the δ18O of meltwater from all four snowpacks increased as melting progressed. This trend is consistent with theoretical results that model isotopic exchange between water and ice as meltwater percolates through a snowpack.We have estimated the systematic error in the hydrograph separation if the isotopic composition of a snow core were used in place of that of meltwater. Assuming no error in the old water or stream water values, the error in the new water fraction depends on: (1) the isotopic difference between the snow core and the old water; (2) the isotopic difference between the snow core and the meltwater; and (3) the new water fraction contributing to the stream flow during a spring melt event. The error is large when snowmelt contributes a dominant fraction of the stream flow, which may be expected where infiltration of snowmelt is limited (e.g. permafrost, urban areas). A particular challenge will be how to incorporate the changes in isotopic composition of meltwater measured at a point into hydrograph separation models conducted at the watershed scale. Published in 2002 by John Wiley & Sons, Ltd.