101
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Analysis of seven purines and pyrimidines in pork meat products by ultra high performance liquid chromatography–tandem mass spectrometry. J Chromatogr A 2010; 1217:4294-9. [DOI: 10.1016/j.chroma.2010.04.033] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Revised: 03/23/2010] [Accepted: 04/12/2010] [Indexed: 11/30/2022]
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102
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Chen D, Wang Q, Jin J, Wu P, Wang H, Yu S, Zhang H, Cai C. Low-Potential Detection of Endogenous and Physiological Uric Acid at Uricase−Thionine−Single-Walled Carbon Nanotube Modified Electrodes. Anal Chem 2010; 82:2448-55. [DOI: 10.1021/ac9028246] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Dongxiao Chen
- Jiangsu Key Laboratory of Biofunctional Materials, Laboratory of Electrochemistry, College of Chemistry and Environmental Science, and College of Life Science, Nanjing Normal University, Nanjing 210046, People’s Republic of China
| | - Qian Wang
- Jiangsu Key Laboratory of Biofunctional Materials, Laboratory of Electrochemistry, College of Chemistry and Environmental Science, and College of Life Science, Nanjing Normal University, Nanjing 210046, People’s Republic of China
| | - Juan Jin
- Jiangsu Key Laboratory of Biofunctional Materials, Laboratory of Electrochemistry, College of Chemistry and Environmental Science, and College of Life Science, Nanjing Normal University, Nanjing 210046, People’s Republic of China
| | - Ping Wu
- Jiangsu Key Laboratory of Biofunctional Materials, Laboratory of Electrochemistry, College of Chemistry and Environmental Science, and College of Life Science, Nanjing Normal University, Nanjing 210046, People’s Republic of China
| | - Hui Wang
- Jiangsu Key Laboratory of Biofunctional Materials, Laboratory of Electrochemistry, College of Chemistry and Environmental Science, and College of Life Science, Nanjing Normal University, Nanjing 210046, People’s Republic of China
| | - Shuqin Yu
- Jiangsu Key Laboratory of Biofunctional Materials, Laboratory of Electrochemistry, College of Chemistry and Environmental Science, and College of Life Science, Nanjing Normal University, Nanjing 210046, People’s Republic of China
| | - Hui Zhang
- Jiangsu Key Laboratory of Biofunctional Materials, Laboratory of Electrochemistry, College of Chemistry and Environmental Science, and College of Life Science, Nanjing Normal University, Nanjing 210046, People’s Republic of China
| | - Chenxin Cai
- Jiangsu Key Laboratory of Biofunctional Materials, Laboratory of Electrochemistry, College of Chemistry and Environmental Science, and College of Life Science, Nanjing Normal University, Nanjing 210046, People’s Republic of China
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103
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Zhang J, Chakraborty U, Foley JP. Determination of residual cell culture media components by MEKC. Electrophoresis 2009; 30:3971-7. [DOI: 10.1002/elps.200900169] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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104
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Kim KM, Henderson GN, Ouyang X, Frye RF, Sautin YY, Feig DI, Johnson RJ. A sensitive and specific liquid chromatography-tandem mass spectrometry method for the determination of intracellular and extracellular uric acid. J Chromatogr B Analyt Technol Biomed Life Sci 2009; 877:2032-8. [PMID: 19520625 DOI: 10.1016/j.jchromb.2009.05.037] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Revised: 04/21/2009] [Accepted: 05/18/2009] [Indexed: 12/13/2022]
Abstract
Uric acid (UA) is known to be a major biological antioxidant in plasma. However, there is a strong correlation between UA levels and cardiovascular risk. Recent studies suggest that in the intracellular environment, UA can become a prooxidant that causes endothelial dysfunction. For conducting detailed studies of UA's role in human pathogenesis, there is a critical need for a sensitive and specific method for the determination of intracellular UA levels. We therefore developed a simple, sensitive method for determination of trace amounts of intracellular UA, as well as comparatively large amounts of UA in plasma and urine (for the determination of extracellular concentrations of UA), based on liquid chromatography and tandem mass spectrometry (LC-MS/MS). UA was separated from interferences by HPLC and quantified by mass spectrometry in the negative ESI mode using single reaction monitoring (SRM). For the identification and quantification of UA, the parent ions selected were m/z 167.0, which corresponds to the urate anion, and m/z 169.0, which corresponds to the 1,3-(15)N(2)-UA anion. 1,3-(15)N(2)-UA is used as an internal standard to ensure accuracy of the measurement. After precipitation of proteins with 10% TCA solution, UA was subjected to LC-MS/MS analysis. The correlation coefficient was 0.9998-1.0000 based on the calibration curve. The intra- and inter-day precision (C.V. %) ranged from 0.01 to 3.07 and 0.01 to 3.68 for in vivo and in vitro systems, respectively. Recovery tests of added standards have been successfully performed and the values ranged from 90.10 to 103.59% and 98.74 to 106.12% for in vivo and in vitro analyses, respectively. This study demonstrates that intracellular levels of UA can be measured using LC-MS/MS with isotope labeled UA as an internal standard.
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Affiliation(s)
- Kyung Mee Kim
- Department of Medicine, Division of Nephrology, Hypertension and Transplantation, University of Florida, Gainesville, FL 32610, USA.
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105
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Li H, Rose MJ, Tran L, Zhang J, Miranda LP, James CA, Sasu BJ. Development of a method for the sensitive and quantitative determination of hepcidin in human serum using LC-MS/MS. J Pharmacol Toxicol Methods 2009; 59:171-80. [DOI: 10.1016/j.vascn.2009.02.004] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Accepted: 02/12/2009] [Indexed: 01/11/2023]
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106
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Direct Determination of Uric Acid in Human Serum Samples Using Polypyrrole Nanoelectrode Ensembles. B KOREAN CHEM SOC 2009. [DOI: 10.5012/bkcs.2009.30.2.454] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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107
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Shan D, Wang Y, Zhu M, Xue H, Cosnier S, Wang C. Development of a high analytical performance-xanthine biosensor based on layered double hydroxides modified-electrode and investigation of the inhibitory effect by allopurinol. Biosens Bioelectron 2009; 24:1171-6. [DOI: 10.1016/j.bios.2008.07.023] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 06/06/2008] [Accepted: 07/01/2008] [Indexed: 11/30/2022]
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108
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Tan L, Yang GM, Wang P, Xie ZY, Bai HP, Lu XX, Yang YH. Direct Determination of Uric Acid Based on Pd Nanoparticles Electrodepositing onto Anatase-Type TiO2Nanoparticles/Chitsan Film-Modified Electrode. ANAL LETT 2008. [DOI: 10.1080/00032710802421848] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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109
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Khosravan R, Kukulka MJ, Wu JT, Joseph-Ridge N, Vernillet L. The effect of age and gender on pharmacokinetics, pharmacodynamics, and safety of febuxostat, a novel nonpurine selective inhibitor of xanthine oxidase. J Clin Pharmacol 2008; 48:1014-24. [PMID: 18635756 DOI: 10.1177/0091270008322035] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Febuxostat is a novel nonpurine selective inhibitor of xanthine oxidase, which is currently being developed for the management of hyperuricemia in patients with gout. The effect of age and gender on the pharmacokinetics, pharmacodynamics, and safety of once-daily oral febuxostat 80 mg was assessed in healthy male and female subjects after 7 days. Following multiple dosing with febuxostat, there were no statistically significant differences in the plasma or urinary pharmacokinetic or pharmacodynamic parameters between subjects aged 18 to 40 years and >or=65 years. Although unbound peak concentration (C(max,u)) and area under the concentration-time curve (AUC(24,u)) for febuxostat were higher in women as compared with men (31.5 vs 23.6 ng/mL, P <or= .01, and 62.8 vs 53.9 ng x h/mL, P <or= .05, for C(max,u) and AUC(24,u), respectively), the differences were not considered clinically significant and could be largely accounted for by weight differences between male and female subjects. For pharmacodynamic parameters, even though the percentage decrease in serum uric acid 24-hour mean concentration was slightly greater in women than in men (59% vs 52%, P <or= .01), this difference was not considered clinically meaningful. Febuxostat was well tolerated in male and female subjects in both age groups. Age or gender had no clinically significant effect on the pharmacokinetics, pharmacodynamics, or safety of febuxostat. Therefore, febuxostat does not require any dose adjustments based on age or gender.
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Affiliation(s)
- Reza Khosravan
- TAP Pharmaceutical Products Inc, Lake Forest, Illinois, USA
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110
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Zhao S, Wang J, Ye F, Liu YM. Determination of uric acid in human urine and serum by capillary electrophoresis with chemiluminescence detection. Anal Biochem 2008; 378:127-31. [DOI: 10.1016/j.ab.2008.04.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2007] [Revised: 04/04/2008] [Accepted: 04/07/2008] [Indexed: 11/28/2022]
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111
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Kathiwala M, Affum AO, Perry J, Brajter-Toth A. Direct measurements of xanthine in 2000-fold diluted xanthinuric urine with a nanoporous carbon fiber sensor. Analyst 2008; 133:810-6. [PMID: 18493684 DOI: 10.1039/b718125f] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
High selectivity and sensitivity is reported in the measurements of xanthine in urine by fast scan cyclic voltammetry (FSV) with a nanostructured carbon fiber sensor of 3.5 +/- 0.4 mum radius. Fabrication of the sensors for the measurements is described. Fabrication of the nanostructure at the carbon fiber sensor surface exposes surface pores. SEM images confirm the formation of the nanostructure. The results indicate that the nanostructure improves the sensitivity and limit of detection (LOD) in the measurements of xanthine and uric acid. The sensors allow rapid direct measurements of xanthine in 2000-fold diluted xanthinuric urine and of uric acid in 2000-fold diluted normal urine. The sensitivity and the LOD of xanthine is 0.40 +/- 0.02 nA microM(-1) (0.995) and 1 microM, respectively, and 0.99 +/- 0.01 nA microM(-1) (0.998) and 500 nM for uric acid. The concentration of xanthine in 2000-fold diluted xanthinuric urine is 1.6 +/- 0.2 muM from FSV and from HPLC. The concentration of xanthine and uric acid in urine can be determined by pre- or post-calibration of the sensor in buffer or by the method of standard addition.
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Affiliation(s)
- Mehjabin Kathiwala
- University of Florida, Department of Chemistry, Gainesville, FL 32611-7200, USA
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112
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Kamel AH. Conventional and planar chip sensors for potentiometric assay of uric acid in biological fluids using flow injection analysis. J Pharm Biomed Anal 2007; 45:341-8. [PMID: 17604587 DOI: 10.1016/j.jpba.2007.05.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Revised: 05/08/2007] [Accepted: 05/14/2007] [Indexed: 10/23/2022]
Abstract
The potentiometric response properties of several PVC-based membrane sensors using phthalocyanine complexes of cobalt(II) (CoPC) and Fe(II) (FePC) as anion carriers, towards uric acid were constructed and characterized. The sensors demonstrated fast near-Nernstian response for uric acid over the concentration ranges 9.1 x 10(-6) to 9.1 x 10(-2) and 3.1 x 10(-5) to 3.1 x 10(-2)M with detection limits 0.67 and 2.85 microg mL(-1) over pH 6.5-8 for CoPC and FePC based membrane sensors plasticized with o-NPOE and 1% TDMAC, respectively. A novel solid-state planar chip urate sensor was developed, characterized according to IUPAC recommendations, easily used in a single channel wall-jet flow injection system and compared with a tubular detector. The intrinsic characteristics of the detectors in a low dispersion manifold were determined and compared with data obtained under hydrodynamic mode of operation. Validation of the assay methods with the proposed sensors by measuring the lower limit, range, accuracy, precision, repeatability and between-day-variability revealed good performance characteristics confirming applicability for continuous determination of uric acid. The sensors were used for determining urate in biological fluids at an input rate of 50 samples per hour. The results compare favorably with data obtained by the standard spectrophotometry.
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Affiliation(s)
- Ayman H Kamel
- Department of Chemistry, Faculty of Science, Ain-Shams University, Cairo, Egypt.
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113
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Murphy AT, Witcher DR, Luan P, Wroblewski VJ. Quantitation of hepcidin from human and mouse serum using liquid chromatography tandem mass spectrometry. Blood 2007; 110:1048-54. [PMID: 17435114 DOI: 10.1182/blood-2006-11-057471] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The hepatic peptide hormone hepcidin is considered the central regulator of iron metabolism. Characterizing the circulating levels of this peptide is critical to understanding its role in the development of clinically relevant syndromes, such as anemia of inflammation/chronic disease, and may provide insight into potential clinical interventions. While quantitative methods have been published for the determination of urinary hepcidin and serum prohepcidin, no definitive methods have been published for the determination of hepcidin in serum. In this report, we describe a quantitative method for the determination of both human and mouse hepcidin in serum and plasma. The method employs protein precipitation and solid-phase extraction followed by liquid chromatographic separation and tandem mass spectrometry detection. The method has a quantitative range of 0.25 ng/mL to 500 ng/mL serum for mouse hepcidin and 1 ng/mL to 500 ng/mL serum for human hepcidin. The method uses small sample volumes (50 microL for mice and 100 microL for humans) and 96-well formats for rapid sample processing. The method was used to establish baseline serum and plasma concentrations of hepcidin in normal C57Bl/6 mice and healthy human volunteers.
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Affiliation(s)
- Anthony T Murphy
- Department of Drug Disposition Bioproducts, Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN 46285, USA.
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