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Jos H Beijnen - One of the best experts on this subject based on the ideXlab platform.
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food effect study on uracil and Dihydrouracil plasma levels as marker for dihydropyrimidine dehydrogenase activity in human volunteers
British Journal of Clinical Pharmacology, 2018Co-Authors: Linda M Henricks, Bart A W Jacobs, Didier Meulendijks, Dick Pluim, Daan Van Den Broek, Niels De Vries, Hilde Rosing, Jos H Beijnen, Alwin D R HuitemaAbstract:AIMS: This study aimed to determine the effect of food intake on uracil and Dihydrouracil plasma levels. These levels are a promising marker for dihydropyrimidine dehydrogenase activity and for individualizing fluoropyrimidine anticancer therapy. METHODS: A randomized, cross-over study in 16 healthy volunteers was performed, in which subjects were examined in fasted and fed state on two separate days. In fed condition, a high-fat, high-caloric breakfast was consumed between 8:00 h and 8:30 h. Whole blood for determination of uracil, Dihydrouracil and uridine plasma levels was drawn on both test days at predefined time points between 8:00 h and 13:00 h. RESULTS: Uracil levels were statistically significantly different between fasting and fed state. At 13:00 h, the mean uracil level in fasting state was 12.6 ± 3.7 ng ml-1 and after a test meal 9.4 ± 2.6 ng ml-1 (P < 0.001). Dihydrouracil levels were influenced by food intake as well (mean Dihydrouracil level at 13:00 h in fasting state 147.0 ± 36.4 ng ml-1 and in fed state 85.7 ± 22.1 ng ml-1 , P < 0.001). Uridine plasma levels showed curves with similar patterns as for uracil. CONCLUSIONS: It was shown that both uracil and Dihydrouracil levels were higher in fasting state than in fed state. This is hypothesized to be an direct effect of uridine plasma levels, which were previously shown to be elevated in fasting state and reduced after intake of food. These findings show that, when assessing plasma uracil and Dihydrouracil levels for adaptive fluoropyrimidine dosing in clinical practice, sampling should be done between 8:00 h and 9:00 h after overnight fasting to avoid bias caused by circadian rhythm and food effects.
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the impact of liver resection on the Dihydrouracil uracil plasma ratio in patients with colorectal liver metastases
European Journal of Clinical Pharmacology, 2018Co-Authors: Bart A W Jacobs, Niels De Vries, Hilde Rosing, Jos H Beijnen, Nikol Snoeren, Morsal Samim, Maarten J Deenen, Jan H M SchellensAbstract:Purpose The Dihydrouracil (DHU):uracil (U) plasma ratio is a promising marker for identification of dihydropyrimidine dehydrogenase (DPD)-deficient patients. The objective of this study was to determine the effect of liver resection on the DHU:U plasma ratio in patients with colorectal liver metastases (CRLM).
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liquid chromatography tandem mass spectrometric assay for the analysis of uracil 5 6 Dihydrouracil and β ureidopropionic acid in urine for the measurement of the activities of the pyrimidine catabolic enzymes
Journal of Chromatography B, 2006Co-Authors: Rolf W Sparidans, Jan H M Schellens, Tessa M Bosch, M Jorger, Jos H BeijnenAbstract:Abstract A liquid chromatography–tandem mass spectrometric assay for the determination of uracil, 5,6-Dihydrouracil and β-ureidopropionic acid in urine was developed to measure the activities of enzymes involved in pyrimidine breakdown. The assay was required to investigate the relation between the uracil–Dihydrouracil ratio and toxicities observed after treatment with fluoropyrimidines drugs. After addition of stable isotopically labelled internal standards, the analytes were isolated from a 100-μl urine sample using liquid–liquid extraction with ethyl acetate–2-propanol. Compounds were separated on an Atlantis dC18 column, using ammonium acetate–formic acid in water as the eluent. The eluate was totally led into an electrospray interface with positive ionisation and the analytes were quantified using triple quadrupole mass spectrometry. The assay was validated in the range 1.6–1600 μM, using both, artificial urine and pooled urine as matrices. Intra-day precisions were ≤8% and inter-day precisions were ≤10%. Accuracies between 91 and 108% were found. The analytes were chemically stable under all relevant conditions and the assay was successfully applied in two clinical studies of cancer patients treated with 5-fluorouracil or capecitabine.
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Liquid chromatography–tandem mass spectrometric assay for the analysis of uracil, 5,6-Dihydrouracil and β-ureidopropionic acid in urine for the measurement of the activities of the pyrimidine catabolic enzymes☆
Journal of Chromatography B, 2006Co-Authors: Rolf W Sparidans, Jan H M Schellens, Tessa M Bosch, M Jorger, Jos H BeijnenAbstract:Abstract A liquid chromatography–tandem mass spectrometric assay for the determination of uracil, 5,6-Dihydrouracil and β-ureidopropionic acid in urine was developed to measure the activities of enzymes involved in pyrimidine breakdown. The assay was required to investigate the relation between the uracil–Dihydrouracil ratio and toxicities observed after treatment with fluoropyrimidines drugs. After addition of stable isotopically labelled internal standards, the analytes were isolated from a 100-μl urine sample using liquid–liquid extraction with ethyl acetate–2-propanol. Compounds were separated on an Atlantis dC18 column, using ammonium acetate–formic acid in water as the eluent. The eluate was totally led into an electrospray interface with positive ionisation and the analytes were quantified using triple quadrupole mass spectrometry. The assay was validated in the range 1.6–1600 μM, using both, artificial urine and pooled urine as matrices. Intra-day precisions were ≤8% and inter-day precisions were ≤10%. Accuracies between 91 and 108% were found. The analytes were chemically stable under all relevant conditions and the assay was successfully applied in two clinical studies of cancer patients treated with 5-fluorouracil or capecitabine.
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Liquid chromatography-tandem mass spectrometric assay for the analysis of uracil, 5,6-Dihydrouracil and beta-ureidopropionic acid in urine for the measurement of the activities of the pyrimidine catabolic enzymes.
Journal of chromatography. B Analytical technologies in the biomedical and life sciences, 2006Co-Authors: Rolf W Sparidans, Jan H M Schellens, Tessa M Bosch, M Jorger, Jos H BeijnenAbstract:A liquid chromatography-tandem mass spectrometric assay for the determination of uracil, 5,6-Dihydrouracil and beta-ureidopropionic acid in urine was developed to measure the activities of enzymes involved in pyrimidine breakdown. The assay was required to investigate the relation between the uracil-Dihydrouracil ratio and toxicities observed after treatment with fluoropyrimidines drugs. After addition of stable isotopically labelled internal standards, the analytes were isolated from a 100-microl urine sample using liquid-liquid extraction with ethyl acetate-2-propanol. Compounds were separated on an Atlantis dC18 column, using ammonium acetate-formic acid in water as the eluent. The eluate was totally led into an electrospray interface with positive ionisation and the analytes were quantified using triple quadrupole mass spectrometry. The assay was validated in the range 1.6-1600 microM, using both, artificial urine and pooled urine as matrices. Intra-day precisions were < or = 8% and inter-day precisions were < or = 10%. Accuracies between 91 and 108% were found. The analytes were chemically stable under all relevant conditions and the assay was successfully applied in two clinical studies of cancer patients treated with 5-fluorouracil or capecitabine.
Jan H M Schellens - One of the best experts on this subject based on the ideXlab platform.
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the impact of liver resection on the Dihydrouracil uracil plasma ratio in patients with colorectal liver metastases
European Journal of Clinical Pharmacology, 2018Co-Authors: Bart A W Jacobs, Niels De Vries, Hilde Rosing, Jos H Beijnen, Nikol Snoeren, Morsal Samim, Maarten J Deenen, Jan H M SchellensAbstract:Purpose The Dihydrouracil (DHU):uracil (U) plasma ratio is a promising marker for identification of dihydropyrimidine dehydrogenase (DPD)-deficient patients. The objective of this study was to determine the effect of liver resection on the DHU:U plasma ratio in patients with colorectal liver metastases (CRLM).
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liquid chromatography tandem mass spectrometric assay for the analysis of uracil 5 6 Dihydrouracil and β ureidopropionic acid in urine for the measurement of the activities of the pyrimidine catabolic enzymes
Journal of Chromatography B, 2006Co-Authors: Rolf W Sparidans, Jan H M Schellens, Tessa M Bosch, M Jorger, Jos H BeijnenAbstract:Abstract A liquid chromatography–tandem mass spectrometric assay for the determination of uracil, 5,6-Dihydrouracil and β-ureidopropionic acid in urine was developed to measure the activities of enzymes involved in pyrimidine breakdown. The assay was required to investigate the relation between the uracil–Dihydrouracil ratio and toxicities observed after treatment with fluoropyrimidines drugs. After addition of stable isotopically labelled internal standards, the analytes were isolated from a 100-μl urine sample using liquid–liquid extraction with ethyl acetate–2-propanol. Compounds were separated on an Atlantis dC18 column, using ammonium acetate–formic acid in water as the eluent. The eluate was totally led into an electrospray interface with positive ionisation and the analytes were quantified using triple quadrupole mass spectrometry. The assay was validated in the range 1.6–1600 μM, using both, artificial urine and pooled urine as matrices. Intra-day precisions were ≤8% and inter-day precisions were ≤10%. Accuracies between 91 and 108% were found. The analytes were chemically stable under all relevant conditions and the assay was successfully applied in two clinical studies of cancer patients treated with 5-fluorouracil or capecitabine.
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Liquid chromatography–tandem mass spectrometric assay for the analysis of uracil, 5,6-Dihydrouracil and β-ureidopropionic acid in urine for the measurement of the activities of the pyrimidine catabolic enzymes☆
Journal of Chromatography B, 2006Co-Authors: Rolf W Sparidans, Jan H M Schellens, Tessa M Bosch, M Jorger, Jos H BeijnenAbstract:Abstract A liquid chromatography–tandem mass spectrometric assay for the determination of uracil, 5,6-Dihydrouracil and β-ureidopropionic acid in urine was developed to measure the activities of enzymes involved in pyrimidine breakdown. The assay was required to investigate the relation between the uracil–Dihydrouracil ratio and toxicities observed after treatment with fluoropyrimidines drugs. After addition of stable isotopically labelled internal standards, the analytes were isolated from a 100-μl urine sample using liquid–liquid extraction with ethyl acetate–2-propanol. Compounds were separated on an Atlantis dC18 column, using ammonium acetate–formic acid in water as the eluent. The eluate was totally led into an electrospray interface with positive ionisation and the analytes were quantified using triple quadrupole mass spectrometry. The assay was validated in the range 1.6–1600 μM, using both, artificial urine and pooled urine as matrices. Intra-day precisions were ≤8% and inter-day precisions were ≤10%. Accuracies between 91 and 108% were found. The analytes were chemically stable under all relevant conditions and the assay was successfully applied in two clinical studies of cancer patients treated with 5-fluorouracil or capecitabine.
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Liquid chromatography-tandem mass spectrometric assay for the analysis of uracil, 5,6-Dihydrouracil and beta-ureidopropionic acid in urine for the measurement of the activities of the pyrimidine catabolic enzymes.
Journal of chromatography. B Analytical technologies in the biomedical and life sciences, 2006Co-Authors: Rolf W Sparidans, Jan H M Schellens, Tessa M Bosch, M Jorger, Jos H BeijnenAbstract:A liquid chromatography-tandem mass spectrometric assay for the determination of uracil, 5,6-Dihydrouracil and beta-ureidopropionic acid in urine was developed to measure the activities of enzymes involved in pyrimidine breakdown. The assay was required to investigate the relation between the uracil-Dihydrouracil ratio and toxicities observed after treatment with fluoropyrimidines drugs. After addition of stable isotopically labelled internal standards, the analytes were isolated from a 100-microl urine sample using liquid-liquid extraction with ethyl acetate-2-propanol. Compounds were separated on an Atlantis dC18 column, using ammonium acetate-formic acid in water as the eluent. The eluate was totally led into an electrospray interface with positive ionisation and the analytes were quantified using triple quadrupole mass spectrometry. The assay was validated in the range 1.6-1600 microM, using both, artificial urine and pooled urine as matrices. Intra-day precisions were < or = 8% and inter-day precisions were < or = 10%. Accuracies between 91 and 108% were found. The analytes were chemically stable under all relevant conditions and the assay was successfully applied in two clinical studies of cancer patients treated with 5-fluorouracil or capecitabine.
Willem Kulik - One of the best experts on this subject based on the ideXlab platform.
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quantification of 5 6 Dihydrouracil by hplc electrospray tandem mass spectrometry
Clinical Chemistry, 2004Co-Authors: Andre B P Van Kuilenburg, Henk Van Lenthe, Arno Van Cruchten, Willem KulikAbstract:In humans, the pathway for the catabolism of uracil and thymine consists of three consecutive steps. Dihydropyrimidine dehydrogenase catalyzes the reduction of uracil and thymine to 5,6-Dihydrouracil and 5,6-dihydrothymine, respectively. The second step is catalyzed by dihydropyrimidinase and consists of reversible hydrolysis of 5,6-Dihydrouracil and 5,6-dihydrothymine to N -carbamyl-β-alanine and N -carbamyl-β-aminoisobutyric acid, respectively. Finally, β-ureidopropionase catalyzes the conversion of N -carbamyl-β-alanine and N -carbamyl-β-aminoisobutyric acid to β-alanine and β-aminoisobutyric acid, respectively, ammonia, and CO2. Patients with a defect in one of the enzymes of the pyrimidine degradation pathway can be diagnosed by an aberrant excretion profile of the pyrimidine bases and their degradation products in urine (1). For example, in patients with a complete deficiency of dihydropyrimidinase, highly increased concentrations of 5,6-Dihydrouracil and 5,6-dihydrothymine and moderately increased concentrations of uracil and thymine can be detected in urine. It has also …
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Quantification of 5,6-Dihydrouracil by HPLC–Electrospray Tandem Mass Spectrometry
Clinical Chemistry, 2004Co-Authors: Andre B P Van Kuilenburg, Henk Van Lenthe, Arno Van Cruchten, Willem KulikAbstract:In humans, the pathway for the catabolism of uracil and thymine consists of three consecutive steps. Dihydropyrimidine dehydrogenase catalyzes the reduction of uracil and thymine to 5,6-Dihydrouracil and 5,6-dihydrothymine, respectively. The second step is catalyzed by dihydropyrimidinase and consists of reversible hydrolysis of 5,6-Dihydrouracil and 5,6-dihydrothymine to N -carbamyl-β-alanine and N -carbamyl-β-aminoisobutyric acid, respectively. Finally, β-ureidopropionase catalyzes the conversion of N -carbamyl-β-alanine and N -carbamyl-β-aminoisobutyric acid to β-alanine and β-aminoisobutyric acid, respectively, ammonia, and CO2. Patients with a defect in one of the enzymes of the pyrimidine degradation pathway can be diagnosed by an aberrant excretion profile of the pyrimidine bases and their degradation products in urine (1). For example, in patients with a complete deficiency of dihydropyrimidinase, highly increased concentrations of 5,6-Dihydrouracil and 5,6-dihydrothymine and moderately increased concentrations of uracil and thymine can be detected in urine. It has also …
Rafael Linden - One of the best experts on this subject based on the ideXlab platform.
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improved determination of uracil and Dihydrouracil in plasma after a loading oral dose of uracil using high performance liquid chromatography with photodiode array detection and porous graphitic carbon stationary phase
Clinical Biochemistry, 2015Co-Authors: Roberta Zilles Hahn, Andres Fernando Andrade Galarza, Anelise Schneider, Marina Venzon Antunes, Gilberto Schwartsmann, Rafael LindenAbstract:Abstract Objectives The aim of this study was to develop and validate a high-performance liquid chromatographic method for the measurement of plasma concentrations of uracil and Dihydrouracil after administration of an oral loading dose of uracil in the context of evaluation of DPD enzyme activity. Design and methods Analytes were extracted from 500 μL plasma sampler with a mixture of ethyl acetate isopropanol (85:15, v/v) after protein precipitation with solid ammonium sulfate. The extract was inject in the porous graphitic carbon stationary phase, eluted with water and acetonitrile in gradient mode, allowing complete separation of uracil, Dihydrouracil and the internal standard (5-fluorouracil). Chromatograms were monitored at 210 and 260 nm. Results Total chromatographic run time, including reequilibration, was 30 min. The assay was linear in the concentration range of 0.2 to 20 μg mL− 1. Accuracy was 98.4–105.3%, intra-assay precision was 5.1–12.1% and between-assay precision was of 5.3–10.1%. Analytes were stable in plasma at room temperature up to 6 h and for three freeze and thaw cycles. Processed samples are stable up to 12 h. Conclusions The developed method was fully validated and has significantly reduced running time when compared to previous assay using porous graphitic stationary phase, allowing complete resolution of uracil, Dihydrouracil and internal standard. This assay might be suitable to investigate the eventual correlation between concentrations of uracil and Dihydrouracil in plasma after an oral loading dose and DPD enzyme activity, with potential contribution to therapeutic drug monitoring.
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Improved determination of uracil and Dihydrouracil in plasma after a loading oral dose of uracil using high-performance liquid chromatography with photodiode array detection and porous graphitic carbon stationary phase.
Clinical biochemistry, 2015Co-Authors: Roberta Zilles Hahn, Andres Fernando Andrade Galarza, Anelise Schneider, Marina Venzon Antunes, Gilberto Schwartsmann, Rafael LindenAbstract:The aim of this study was to develop and validate a high-performance liquid chromatographic method for the measurement of plasma concentrations of uracil and Dihydrouracil after administration of an oral loading dose of uracil in the context of evaluation of DPD enzyme activity. Analytes were extracted from 500μL plasma sampler with a mixture of ethyl acetate isopropanol (85:15, v/v) after protein precipitation with solid ammonium sulfate. The extract was inject in the porous graphitic carbon stationary phase, eluted with water and acetonitrile in gradient mode, allowing complete separation of uracil, Dihydrouracil and the internal standard (5-fluorouracil). Chromatograms were monitored at 210 and 260nm. Total chromatographic run time, including reequilibration, was 30min. The assay was linear in the concentration range of 0.2 to 20μgmL(-1). Accuracy was 98.4-105.3%, intra-assay precision was 5.1-12.1% and between-assay precision was of 5.3-10.1%. Analytes were stable in plasma at room temperature up to 6h and for three freeze and thaw cycles. Processed samples are stable up to 12h. The developed method was fully validated and has significantly reduced running time when compared to previous assay using porous graphitic stationary phase, allowing complete resolution of uracil, Dihydrouracil and internal standard. This assay might be suitable to investigate the eventual correlation between concentrations of uracil and Dihydrouracil in plasma after an oral loading dose and DPD enzyme activity, with potential contribution to therapeutic drug monitoring. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
Rolf W Sparidans - One of the best experts on this subject based on the ideXlab platform.
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liquid chromatography tandem mass spectrometric assay for the analysis of uracil 5 6 Dihydrouracil and β ureidopropionic acid in urine for the measurement of the activities of the pyrimidine catabolic enzymes
Journal of Chromatography B, 2006Co-Authors: Rolf W Sparidans, Jan H M Schellens, Tessa M Bosch, M Jorger, Jos H BeijnenAbstract:Abstract A liquid chromatography–tandem mass spectrometric assay for the determination of uracil, 5,6-Dihydrouracil and β-ureidopropionic acid in urine was developed to measure the activities of enzymes involved in pyrimidine breakdown. The assay was required to investigate the relation between the uracil–Dihydrouracil ratio and toxicities observed after treatment with fluoropyrimidines drugs. After addition of stable isotopically labelled internal standards, the analytes were isolated from a 100-μl urine sample using liquid–liquid extraction with ethyl acetate–2-propanol. Compounds were separated on an Atlantis dC18 column, using ammonium acetate–formic acid in water as the eluent. The eluate was totally led into an electrospray interface with positive ionisation and the analytes were quantified using triple quadrupole mass spectrometry. The assay was validated in the range 1.6–1600 μM, using both, artificial urine and pooled urine as matrices. Intra-day precisions were ≤8% and inter-day precisions were ≤10%. Accuracies between 91 and 108% were found. The analytes were chemically stable under all relevant conditions and the assay was successfully applied in two clinical studies of cancer patients treated with 5-fluorouracil or capecitabine.
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Liquid chromatography–tandem mass spectrometric assay for the analysis of uracil, 5,6-Dihydrouracil and β-ureidopropionic acid in urine for the measurement of the activities of the pyrimidine catabolic enzymes☆
Journal of Chromatography B, 2006Co-Authors: Rolf W Sparidans, Jan H M Schellens, Tessa M Bosch, M Jorger, Jos H BeijnenAbstract:Abstract A liquid chromatography–tandem mass spectrometric assay for the determination of uracil, 5,6-Dihydrouracil and β-ureidopropionic acid in urine was developed to measure the activities of enzymes involved in pyrimidine breakdown. The assay was required to investigate the relation between the uracil–Dihydrouracil ratio and toxicities observed after treatment with fluoropyrimidines drugs. After addition of stable isotopically labelled internal standards, the analytes were isolated from a 100-μl urine sample using liquid–liquid extraction with ethyl acetate–2-propanol. Compounds were separated on an Atlantis dC18 column, using ammonium acetate–formic acid in water as the eluent. The eluate was totally led into an electrospray interface with positive ionisation and the analytes were quantified using triple quadrupole mass spectrometry. The assay was validated in the range 1.6–1600 μM, using both, artificial urine and pooled urine as matrices. Intra-day precisions were ≤8% and inter-day precisions were ≤10%. Accuracies between 91 and 108% were found. The analytes were chemically stable under all relevant conditions and the assay was successfully applied in two clinical studies of cancer patients treated with 5-fluorouracil or capecitabine.
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Liquid chromatography-tandem mass spectrometric assay for the analysis of uracil, 5,6-Dihydrouracil and beta-ureidopropionic acid in urine for the measurement of the activities of the pyrimidine catabolic enzymes.
Journal of chromatography. B Analytical technologies in the biomedical and life sciences, 2006Co-Authors: Rolf W Sparidans, Jan H M Schellens, Tessa M Bosch, M Jorger, Jos H BeijnenAbstract:A liquid chromatography-tandem mass spectrometric assay for the determination of uracil, 5,6-Dihydrouracil and beta-ureidopropionic acid in urine was developed to measure the activities of enzymes involved in pyrimidine breakdown. The assay was required to investigate the relation between the uracil-Dihydrouracil ratio and toxicities observed after treatment with fluoropyrimidines drugs. After addition of stable isotopically labelled internal standards, the analytes were isolated from a 100-microl urine sample using liquid-liquid extraction with ethyl acetate-2-propanol. Compounds were separated on an Atlantis dC18 column, using ammonium acetate-formic acid in water as the eluent. The eluate was totally led into an electrospray interface with positive ionisation and the analytes were quantified using triple quadrupole mass spectrometry. The assay was validated in the range 1.6-1600 microM, using both, artificial urine and pooled urine as matrices. Intra-day precisions were < or = 8% and inter-day precisions were < or = 10%. Accuracies between 91 and 108% were found. The analytes were chemically stable under all relevant conditions and the assay was successfully applied in two clinical studies of cancer patients treated with 5-fluorouracil or capecitabine.