bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gold Electrodes for Detection of Enzyme Assays with 3‐Indoxylphosphate as Substrate
Authors: Castaño‐Álvarez Mario , Fernández‐Abedul M. Teresa , Costa‐García Agustín 
Published: June 2004

AbstractThe advantageous characteristics of gold not only for its electrochemical behavior but also for the unique adsorptive protein characteristics are the basis of this paper. 3‐Indoxyl phosphate (3‐IP) has previously been demonstrated to be a very convenient substrate for the electrochemical detection, using carbon‐based electrodes, of enzymeimmunoassays (EIAs) that employ not only alkaline phosphatase (AP) but also horseradish peroxidase (HRP) as label. Combination of both: gold electrodes and 3‐IP has not been studied and it produces a very suitable detection for EIAs. The electrochemical behavior of indigo, product of the enzymatic hydrolisis of 3‐IP, has been thoroughly studied for the first time on disk and band gold electrodes. The possibility of electrodepositing gold on the bands and automation has also been considered. The detection has been applied for the determination of osteocalcin with an HRP‐based ELISA (enzyme‐linked immunosorbent assay).
Determination of ribavirin in human serum and plasma by capillary electrophoresis
Authors: Breadmore Michael C. , Theurillat Regula , Thormann Wolfgang 
Published: June 2004

AbstractThe electrophoretic separation of ribavirin and 5‐methylcytidine (internal standard) by capillary electrophoresis was examined. Separation was achieved using reverse polarity in a 100 mM borate electrolyte, pH 9.1, with 5 mM spermine added to reduce the electroosmotic flow. Sample preparation based on acetonitrile protein precipitation was found to be unsuitable for ribavirin analysis in patient samples due to insufficient sensitivity and interferences. Solid‐phase extraction employing phenyl boronic acid cartridges provided cleaner separations. Using this approach with 500 μL sample and reconstitution of the dried extract into 100 μL of 33% v/v 100 mM phosphate buffer, pH 6.4 / 67% v/v acetonitrile, the detection and quantitation limits were determined to be 0.05 and 0.10 μg/mL, respectively, a sensitivity that is suitable for therapeutic drug monitoring of ribavirin in human plasma and serum samples. The method was validated and compared to a high‐performance liquid chromatography (HPLC) method, showing excellent agreement between the two for a set of samples that stemmed from patients being treated with ribavirin and interferon‐α‐2b for a hepatitis C virus infection.
Identification of diphenhydramine metabolites in human urine by capillary electrophoresis‐ion trap‐mass spectrometry
Authors: Baldacci Andrea , Prost Francine , Thormann Wolfgang 
Published: June 2004

AbstractThe identification of diphenhydramine (DH) metabolites that are frequently observed in the capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MEKC) analyses of alkaline liquid/liquid and solid‐phase extracts of patient urines is demonstrated. Having standards for DH and diphenhydramine‐N‐oxide (DHNO), the presence of these two compounds could be confirmed in urines that were collected overnight after administration of 25 mg DH chloride. Using CZE coupled to ion‐trap mass spectrometry (CE‐MSn) with positive electrospray ionization and an acetate buffer at pH 5.6, the [M+H]+ ions of DH (m/z = 256), DHNO (m/z = 272), and nordiphenhydramine (NDH, m/z = 242) and their fragmentation to a common m/z 167 product ion (diphenylcarbinol moiety) was monitored. The data indicate that all three compounds are cations in an acidic environment, the migration order being NDH, DH, and DHNO. Data obtained under negative electrospray ionization conditions suggest the presence of diphenylmethoxyacetic acid‐glycine amide ([M‐H]− ion of m/z 298 and fragmentation to m/z 254, loss of CO2), a metabolite that could tentatively be assigned to a characteristic peak observed in the MEKC electropherogram at alkaline pH. The data presented in this paper illustrate the value of using CE‐MSn for identification of urinary drug metabolites for which no standards are available.
Quantitative analysis of DNA methylation in chronic lymphocytic leukemia patients
Authors: Lyko Frank , Stach Dirk , Brenner Axel , Stilgenbauer Stephan , Döhner Hartmut , Wirtz Michaela , Wiessler Manfred , Schmitz Oliver J. 
Published: June 2004

AbstractChanges in the genomic DNA methylation level have been found to be closely associated with tumorigenesis. In order to analyze the relation of aberrant DNA methylation to clinical and biological risk factors, we have determined the cytosine methylation level of 81 patients diagnosed with chronic lymphocytic leukemia (CLL). The analysis was based on DNA hydrolysis followed by derivatization of the 2'‐desoxyribonucleoside‐3'‐monophosphates with BODIPY FL EDA. Derivatives were separated by micellar electrokinetic chromatography, and laser‐induced fluorescence was used for detection. We analyzed potential correlations between DNA methylation levels and numerous patient parameters, including clinical observations and biological data. As a result, we observed a significant correlation with the immunoglobulin variable heavy chain gene (VH) mutation status. This factor has been repeatedly proposed as a reliable prognostic marker for CLL, which suggests that the methylation level might be a valuable factor in determining the prognostic outcome of CLL. We are now in the process of refining our method to broaden its application potential. In this context, we show here that the oxidation of the fluorescence marker in the samples and the evaporation of methanol in the electrolytes can be prevented by a film of paraffin oil. In summary, our results thus establish capillary electrophoresis as a valuable tool for analyzing the DNA methylation status of clinical samples.
Selection of migration parameters for a highly reliable assignment of bands of isoforms of erythropoietin separated by capillary electrophoresis
Authors: Lacunza Izaskun , Lara‐Quintanar Pilar , Moya Galina , Sanz Jesus , Diez‐Masa Jose C. , de Frutos Mercedes 
Published: June 2004

AbstractCapillary zone electrophoresis of samples of recombinant human erythropoietin is performed. An in‐house computer program is developed to compare the reliability of different migration parameters to assign the close migration bands of isoforms of erythropoietin. The migration time relative to the electroosmotic flow marker and the effective electrophoretic mobility are selected as the most accurate parameters. Percentages of correct assignment of bands higher than 99% are obtained with these parameters even when changes in operational factors are introduced. The chosen parameters have been applied to assign bands of isoforms in commercial samples of α‐ and β‐epoetin. The same capillary electrophoresis method has been applied to separate bands of isoforms of an erythropoietin analogue, darbepoetin α, the novel erythropoiesis‐stimulating protein.
Determination of nonsteroidal anti‐inflammatory drugs in human specimens by capillary zone electrophoresis and micellar electrokinetic chromatography
Authors: Makino Kazutaka , Itoh Yoshinori , Teshima Daisuke , Oishi Ryozo 
Published: June 2004

AbstractTherapeutic drug monitoring of anti‐inflammatory drugs is necessary for the identification of the agents that cause toxic events and for the decision on the treatment for intoxication. Recently, capillary electrophoresis (CE) has been developed for the simple and rapid analyses of a variety of chemical agents. Micellar electrokinetic chromatography (MEKC) can separate acidic, neutral and basic anti‐inflammatory drugs in serum. Furthermore, serum samples are directly applied to the CE system without any pretreatments, and some anti‐inflammatory drugs can be separated from serum albumin in the MEKC analysis. On the other hand, capillary zone electrophoresis (CZE) enables us to determine a few μg/mL levels of acidic anti‐inflammatory drugs with simple running buffer and stacking technique. A rapid and simultaneous determination of several analgesic anti‐inflammatory agents, including ibuprofen, acetaminophen, indomethacin, and salicylic acid in human serum has been developed by using CZE. Therefore, the CZE and MEKC analysis may become a potentially useful alternative to high‐performance liquid chromatography (HPLC) and fluorescence polarization immunoassay (FPIA) for therapeutic drug monitoring, particularly in serum of patients suffering from intoxication by overdosage of nonsteroidal anti‐inflammatory agents.
Isotachophoresis of β‐blockers in a capillary and on a poly(methyl methacrylate) chip
Authors: Kriikku Pirkko , Graß Benedikt , Hokkanen Ari , Stuns Ingmar , Sirén Heli 
Published: June 2004

AbstractAnalysis of the β‐blockers oxprenolol, atenolol, timolol, propranolol, metoprolol, and acebutolol in human urine by a combination of isotachophoresis (ITP) and zone electrophoresis (ZE) was investigated. Methods were developed with a conventional capillary electrophoresis (CE) apparatus and a poly(methyl methacrylate) (PMMA) microchip system. With CE the separation of oxprenolol, atenolol, timolol, and acebutolol from a standard solution containing 5 μg/mL of each compound was accomplished by performing ZE with transient ITP. The electrolyte system consisted of 10 mM sodium morpholinoethane sulfonate (pH 5.5) and 0.1% methylhydroxyethylcellulose as the leading electrolyte and 30 mM ortho‐phosphoric acid (pH 2.0) as both the terminating and the ZE background electrolyte. With the microchip system the separation of oxprenolol and acebutolol from a standard solution containing 10 μg/mL of each compound was accomplished by a coupled‐channel ITP‐ZE device using the same leading electrolyte solution as the CE system but 5 mM glutamic acid (pH 3.4) as terminating and background electrolytes. The systems were used for analyses of patient urine samples. Water‐soluble hydrophilic matrix compounds were removed from the urine samples by solid‐phase extraction (SPE). Limits of quantification below 5 μg/mL could be achieved. The PMMA ITP‐ZE chip has not earlier been used for analyses of any drugs from urine samples.
Rapid analysis of inflammatory cytokines in cerebrospinal fluid using chip‐based immunoaffinity electrophoresis
Authors: Phillips Terry M. 
Published: June 2004

AbstractA chip‐based capillary electrophoresis system has been designed for rapidly measuring the concentrations of inflammatory cytokines in the cerebrospinal fluid of patients with head trauma. Isolation of the reactive cytokines was achieved by immunoaffinity capture using a panel of six immobilized antibodies, directly attached to the injection port of the chip. The captured cytokines were labeled in situ with a red light‐emitting laser dye and electroeluted into the separation channel. Separation of the isolated cytokines was achieved by electrophoresis in under 2 min with quantification of the resolved peaks being achieved by on‐line laser‐induced fluorescence and integration of each peak area. Comparison of the results to commercially available high‐sensitivity immunoassays demonstrates that the chip‐based assay provides a fast, accurate procedure for studying the concentrations of these analytes in complex biological materials. The degree of accuracy and precision achieved by the chip‐based CE is comparable to conventional immunoassays, the system being able to analyze between 10–12 samples per hour. With the ever‐expanding array of antibodies that are commercially available, this chip‐based system can be applied to a wide variety of different analyses.
A high‐performance multilane microdevice system designed for the DNA forensics laboratory
Authors: Goedecke Nils , McKenna Brian , El‐Difrawy Sameh , Carey Loucinda , Matsudaira Paul , Ehrlich Daniel 
Published: June 2004

AbstractWe report preliminary testing of “GeneTrack”, an instrument designed for the specific application of multiplexed short tandem repeat (STR) DNA analysis. The system supports a glass microdevice with 16 lanes of 20 cm effective length and double‐T cross injectors. A high‐speed galvanometer‐scanned four‐color detector was specially designed to accommodate the high elution rates on the microdevice. All aspects of the system were carefully matched to practical crime lab requirements for rapid reproducible analysis of crime‐scene DNA evidence in conjunction with the United States DNA database (CODIS). Statistically significant studies demonstrate that an absolute, three‐sigma, peak accuracy of 0.4–0.9 base pair (bp) can be achieved for the CODIS 13‐locus multiplex, utilizing a single channel per sample. Only 0.5 μL of PCR product is needed per lane, a significant reduction in the consumption of costly chemicals in comparison to commercial capillary machines. The instrument is also designed to address problems in temperature‐dependent decalibration and environmental sensitivity, which are weaknesses of the commercial capillary machines for the forensics application.
Quality control and quality assurance aspects of the routine use of capillary electrophoresis for serum and urine proteins in clinical laboratories
Authors: Jenkins Margaret A. 
Published: June 2004

AbstractUsing capillary electrophoresis (CE) for serum protein electrophoresis, the quality of results begins with monitoring a well‐functioning instrument, using scrupulously clean capillaries, well‐calibrated methods as well as regular use of an internal quality control material. Quality assurance programs are available in countries such as Australia, United Kingdom, United States, and European countries such as Sweden and Germany. The present commercial control material that is available gives percentages of albumin, alpha 1, alpha 2, beta‐ and gamma‐globulins, the gamma‐component being of normal distribution, and not containing any monoclonal protein component. We feel that a quantitative commercial control material containing a monoclonal protein at decision level for treating myeloma patients would be beneficial to all laboratories as a serum protein electrophoresis control, whether the analysis is by CE or agarose gels. The same applies for control material for urinary protein electrophoresis.
Recent developments in the determination of urinary cancer biomarkers by capillary electrophoresis
Authors: Ma Yinfa , Liu Guanshu , Du Ming , Stayton Isaac 
Published: June 2004

AbstractInvestigation of effective biomarkers for cancers is currently a popular area of study in clinical and cancer researches, because it can potentially lead to pre‐cancer screening or pre‐cancer diagnosis and may provide useful information on cancer type and the disease's stage of progression. More and more biochemical or chemical fluid components of the human body such as urine, blood, and cerebrospinal fluid have been considered to contain biomarkers, which are useful in cancer researches, pre‐cancer diagnosis, and cancer follow‐ups during or after cancer treatment. Several modern analytical techniques, such as gas chromatography (GC), high‐performance liquid chromatography (HPLC), capillary electrophoresis (CE), and other separation techniques as well as hyphenated techniques, have been extensively used in study of cancer biomarkers. Among these techniques, CE is considered to be a highly efficient and practical analytical technique because of the small sample volume requirement and its wide separation versatility, ranging from small inorganic molecules to large biomolecules. This review discusses the latest developments involving biomarkers and their analysis by CE, including a discussion of instrumental conditions, method developments, and data analysis.
Rapid analysis of antimicrobial metabolites monoacetylphloroglucinol and 2,4‐diacetylphloroglucinol using capillary zone electrophoresis
Authors: Guihen Elizabeth , Glennon Jeremy D. , Cullinane Meabh , O'Gara Fergal 
Published: June 2004

AbstractA rapid capillary electrophoretic (CE) method was developed for the determination of phloroglucinol compounds, monoacetylphloroglucinol (MAPG) and 2,4‐diacetylphloroglucinol (DAPG), in microbial supernatants of Pseudomonas fluorescens F113 over a 24‐h growth cycle. Prior to electrophoretic separation, solid‐phase extraction of supernatant samples on octadecylsilica for the purpose of sample cleanup is recommended. The optimum electrophoretic conditions were found to be 25 mM sodium tetraborate running buffer at pH 9.3, temperature at 25°C with an applied voltage of 25 kV. The capillary was an Agilent fused‐silica capillary of total length 33 cm×50 μm inner diameter, 375 μm outer diameter, with effective length 24.5 cm. While MAPG and DAPG were monitored at selected wavelengths in the range of 214–320 nm, analysis at 214 nm was used and a CE separation time of less than 2 min was achieved. A partial method validation study was performed in accordance with European Agency for Evaluation of Medicinal Products (EMEA) guidelines. The method displayed linearity over the investigated range of 10–200 μg/mL, with limits of detection of 1.2 μg/mL for MAPG and 1.3 μg/mL for DAPG.
Removal of Heavy Metals from the Environment by Biosorption
Authors: Gavrilescu M. 
Published: June 2004

AbstractThe pollution of the environment with toxic metals is a result of many human activities, such as mining and metallurgy, and the effects of these metals on the ecosystems are of large economic and public‐healthsignificance. This paper presents the features and advantages of the unconventional removal method of heavy metals – biosorption – as a part of bioremediation. Bioremediation consists of a group of applications, which involvethe detoxification of hazardous substances instead of transferring them from one medium to another, by means of microbes and plants. This process is characterized as less disruptive and can be often carried out on site, eliminating the need to transport the toxic materials to treatment sites. The biosorption (sorption of metallic ions from solutions by live or dried biomass) offers an alternative to the remediation of industrial effluents as well as the recovery of metals contained in other media. Biosorbents are prepared from naturally abundant and/or waste biomass. Due to the high uptake capacity and very cost‐effective source of the raw material, biosorption is a progression towards a perspective method. The mechanism by which microorganisms take up metals is relatively unclear, but it has been demonstrated that both living and non‐living biomass may be utilized in biosorptive processes, as they often exhibit a marked tolerance towards metals and other adverse conditions. One of their major advantages is the treatment of large volumes of effluents with low concentrations of pollutants. Models developed were presented to determine both the number of adsorption sites required to bind each metal ion and the rate of adsorption, using a batch reactor mass balance and the Langmuir theory of adsorption to surfaces or continuous dynamic systems. Two main categories of bioreactors used in bioremediation – suspended growth and fixed film bioreactors – are discussed. Reactors with varying configurations to meet the different requirements for biosorption are analyzed considering two major groups of reactors –batchreactors andcontinuousreactors. Biosorption is treated as an emerging technology effective in removing even very low levels of heavy metal.
The role of consumer knowledge of insurance benefits in the demand for preventive health care among the elderly
Authors: Parente Stephen T. , Salkever David S. , DaVanzo Joan 
Published: June 2004

AbstractIn 1992, the United States Centers for Medicare and Medicaid Services (CMS) introduced new insurance coverage for two preventive services – influenza vaccinations and mammograms. Economists typically assume transactions occur with perfect information and foresight. As a test of the value of information, we estimate the effect of consumer knowledge of these benefits on their demand. Treating knowledge as endogenous in a two‐part model of demand, we find that consumer knowledge has a substantial positive effect on the use of preventive services. Our findings suggest that strategies to educate the insured Medicare population about coverage of preventive services may have substantial social value. Copyright © 2004 John Wiley & Sons, Ltd.
Linking workplace literacy skills and transfer system perceptions
Authors: Bates Reid , Holton III Elwood F. 
Published: June 2004

AbstractResearch examining the relationship between workplace literacy and training‐related factors is virtually nonexistent. This study examined how variations in individual learning transfer system perceptions were associated with job‐related workplace literacy skill differences. Results indicated significant differences in learning transfer system perceptions for employees who had the math and reading skill levels required for their jobs versus those who did not. Findings suggest a complex and little understood relationship between workplace literacy skills and learning transfer system perceptions.
Analysis of gene expression profiles in human HL‐60 cell exposed to cantharidin using cDNA microarray
Authors: Zhang Jun‐Ping , Ying Kang , Xiao Zhen‐Yu , Zhou Bin , Huang Qing‐Shan , Wu Hong‐Mei , Yin Ming , Xie Yi , Mao Yu‐Min , Rui Yao‐Cheng 
Published: June 2004

AbstractCantharidin is a natural toxin that has antitumor properties and causes leukocytosis as well as increasing sensitivity of tumor cells resistant to other chemotherapeutic agents. There is limited information, however, on the molecular pharmacological mechanisms of cantharidin on human cancer cells. We have used cDNA microarrays to identify gene expression changes in HL‐60 promyeloid leukemia cells exposed to cantharidin. Cantharidin‐treated cells not only decreased expression of genes coding for proteins involved in DNA replication (e.g., DNA polymerase delta), DNA repair (e.g., FANCG, ERCC), energy metabolism (e.g., isocitrate dehydrogenase alpha, ADP/ATP translocase), but also decreased expression of genes coding for proteins that have oncogenic activity (e.g., c‐myc, GTPase) or show tumor‐specific expression (e.g., phosphatidylinositol 3‐kinase). In contrast, these treated cells overexpressed several genes that encode intracellular and secreted growth‐inhibitory proteins (e.g., BTG2, MCP‐3) as well as proapoptotic genes (e.g., ATL‐derived PMA‐responsive peptide). Our findings suggest that alterations in specific genes functionally related to cell proliferation or apoptosis may be responsible for cantharidin‐mediated cytotoxicity. We also found that exposure of HL‐60 cells to cantharidin resulted in the decreased expression of multidrug resistance‐associated protein genes (e.g., ABCA3, MOAT‐B), suggesting that cantharidin may be used as an oncotherapy sensitizer, and the increased expression of genes in modulating cytokine production and inflammatory response (e.g., NFIL‐3, N‐formylpeptide receptor), which may partly explain the stimulating effects on leukocytosis. Our data provide new insight into the molecular mechanisms of cantharidin. © 2003 Wiley‐Liss, Inc.