The Experts below are selected from a list of 33 Experts worldwide ranked by ideXlab platform
María Dolores Luque De Castro - One of the best experts on this subject based on the ideXlab platform.
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Targeting metabolomics analysis of the sunscreen Agent 2-ethylhexyl 4-(N,N-dimethylamino)benzoate in human urine by automated on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry with liquid chromatography-time-of-flight/mass
Journal of chromatography. A, 2011Co-Authors: Zacarías León-gonzález, C. Ferreiro-vera, Feliciano Priego-capote, María Dolores Luque De CastroAbstract:The in vivo metabolism of the Xenobiotic Agent 2-ethylhexyl 4-(N,N-dimethylamino)benzoate (EDP), a UV filter commonly used in sunscreen cosmetic products, was studied by targeting metabolomics analysis in human urine. The metabolomic study involved the use of urine from male and female volunteers before and after application of an EDP-containing sunscreen cosmetic. The metabolism of EDP in urine was studied by using the triple quadrupole detector in a combination of Precursor Ion Scanning and Neutral Loss Scanning modes, with and without enzymatic hydrolysis. Detected metabolites were subsequently confirmed as glucuronide conjugates of 4-(N,N-dimethylamino)benzoic acid and 4-(N-methylamino)benzoic acid by liquid chromatography-time-of-flight/mass spectrometry (LC-TOF/MS) in the accurate mass mode. In this way, the existence of phase II metabolism in the detoxification of EDP by effects of the lipophilic character of this sunscreen Agent was confirmed. Hence, to study the in vivo metabolism of EDP, a fully automated method using a solid-phase extraction (SPE) workstation connected on-line to a liquid chromatograph and a triple quadrupole mass analyzer (LC-MS/MS) was developed. The ensuing hyphenated method is very simple and requires minimal human intervention. Following thorough optimization of the SPE and LC-MS/MS conditions, the analytical procedure was validated and standard addition calibration used for the quantitative correction of matrix effects. The proposed method was applied to determine the phase I metabolites of EDP in urine samples and afforded limits of detection from 0.1 to 1.1 ng and accuracy of 91-107% with relative standard deviations in the range 1.5-8.7% (sample volume: 100 μL). Based on the results of in vivo percutaneous absorption of a single application of the sunscreen, about 0.5% of the amount of the applied EDP is excreted in urine.
Robert A. Roth - One of the best experts on this subject based on the ideXlab platform.
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Concurrent inflammation as a determinant of susceptibility to toxicity from Xenobiotic Agents
Toxicology, 2001Co-Authors: Patricia E. Ganey, Robert A. RothAbstract:Sensitivity to the toxic effects of Xenobiotic Agents is influenced by a number of factors. Recent evidence derived from studies using experimental animals suggests that inflammation is one of these factors. For example, induction of inflammation by coexposure to bacterial endotoxin, vitamin A or Corynebacterium parvum increases injury in response to a number of Xenobiotic Agents that target liver. These Agents are diverse in chemical nature and in mechanism of hepatotoxic action. Factors critical to the augmentation of liver injury by inflammation include Kupffer cells, neutrophils, cytokines such as tumor necrosis factor-alpha (TNF-alpha) and lipid mediators such as prostaglandins, but these may vary depending on the Xenobiotic Agent and the mechanisms by which it alters hepatocellular homeostasis. In addition, the timing of inflammagen exposure can qualitatively alter the toxic response to chemicals. Inflammation-induced increases in susceptibility to toxicity are not limited to liver. Concurrent inflammation also sensitizes animals to the toxic effects of Agents that damage the respiratory tract, kidney and lymphoid tissue. It is concluded that inflammation should be considered as a determinant of susceptibility to intoxication by Xenobiotic exposure.
Zacarías León-gonzález - One of the best experts on this subject based on the ideXlab platform.
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Targeting metabolomics analysis of the sunscreen Agent 2-ethylhexyl 4-(N,N-dimethylamino)benzoate in human urine by automated on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry with liquid chromatography-time-of-flight/mass
Journal of chromatography. A, 2011Co-Authors: Zacarías León-gonzález, C. Ferreiro-vera, Feliciano Priego-capote, María Dolores Luque De CastroAbstract:The in vivo metabolism of the Xenobiotic Agent 2-ethylhexyl 4-(N,N-dimethylamino)benzoate (EDP), a UV filter commonly used in sunscreen cosmetic products, was studied by targeting metabolomics analysis in human urine. The metabolomic study involved the use of urine from male and female volunteers before and after application of an EDP-containing sunscreen cosmetic. The metabolism of EDP in urine was studied by using the triple quadrupole detector in a combination of Precursor Ion Scanning and Neutral Loss Scanning modes, with and without enzymatic hydrolysis. Detected metabolites were subsequently confirmed as glucuronide conjugates of 4-(N,N-dimethylamino)benzoic acid and 4-(N-methylamino)benzoic acid by liquid chromatography-time-of-flight/mass spectrometry (LC-TOF/MS) in the accurate mass mode. In this way, the existence of phase II metabolism in the detoxification of EDP by effects of the lipophilic character of this sunscreen Agent was confirmed. Hence, to study the in vivo metabolism of EDP, a fully automated method using a solid-phase extraction (SPE) workstation connected on-line to a liquid chromatograph and a triple quadrupole mass analyzer (LC-MS/MS) was developed. The ensuing hyphenated method is very simple and requires minimal human intervention. Following thorough optimization of the SPE and LC-MS/MS conditions, the analytical procedure was validated and standard addition calibration used for the quantitative correction of matrix effects. The proposed method was applied to determine the phase I metabolites of EDP in urine samples and afforded limits of detection from 0.1 to 1.1 ng and accuracy of 91-107% with relative standard deviations in the range 1.5-8.7% (sample volume: 100 μL). Based on the results of in vivo percutaneous absorption of a single application of the sunscreen, about 0.5% of the amount of the applied EDP is excreted in urine.
Patricia E. Ganey - One of the best experts on this subject based on the ideXlab platform.
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Concurrent inflammation as a determinant of susceptibility to toxicity from Xenobiotic Agents
Toxicology, 2001Co-Authors: Patricia E. Ganey, Robert A. RothAbstract:Sensitivity to the toxic effects of Xenobiotic Agents is influenced by a number of factors. Recent evidence derived from studies using experimental animals suggests that inflammation is one of these factors. For example, induction of inflammation by coexposure to bacterial endotoxin, vitamin A or Corynebacterium parvum increases injury in response to a number of Xenobiotic Agents that target liver. These Agents are diverse in chemical nature and in mechanism of hepatotoxic action. Factors critical to the augmentation of liver injury by inflammation include Kupffer cells, neutrophils, cytokines such as tumor necrosis factor-alpha (TNF-alpha) and lipid mediators such as prostaglandins, but these may vary depending on the Xenobiotic Agent and the mechanisms by which it alters hepatocellular homeostasis. In addition, the timing of inflammagen exposure can qualitatively alter the toxic response to chemicals. Inflammation-induced increases in susceptibility to toxicity are not limited to liver. Concurrent inflammation also sensitizes animals to the toxic effects of Agents that damage the respiratory tract, kidney and lymphoid tissue. It is concluded that inflammation should be considered as a determinant of susceptibility to intoxication by Xenobiotic exposure.
Feliciano Priego-capote - One of the best experts on this subject based on the ideXlab platform.
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Targeting metabolomics analysis of the sunscreen Agent 2-ethylhexyl 4-(N,N-dimethylamino)benzoate in human urine by automated on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry with liquid chromatography-time-of-flight/mass
Journal of chromatography. A, 2011Co-Authors: Zacarías León-gonzález, C. Ferreiro-vera, Feliciano Priego-capote, María Dolores Luque De CastroAbstract:The in vivo metabolism of the Xenobiotic Agent 2-ethylhexyl 4-(N,N-dimethylamino)benzoate (EDP), a UV filter commonly used in sunscreen cosmetic products, was studied by targeting metabolomics analysis in human urine. The metabolomic study involved the use of urine from male and female volunteers before and after application of an EDP-containing sunscreen cosmetic. The metabolism of EDP in urine was studied by using the triple quadrupole detector in a combination of Precursor Ion Scanning and Neutral Loss Scanning modes, with and without enzymatic hydrolysis. Detected metabolites were subsequently confirmed as glucuronide conjugates of 4-(N,N-dimethylamino)benzoic acid and 4-(N-methylamino)benzoic acid by liquid chromatography-time-of-flight/mass spectrometry (LC-TOF/MS) in the accurate mass mode. In this way, the existence of phase II metabolism in the detoxification of EDP by effects of the lipophilic character of this sunscreen Agent was confirmed. Hence, to study the in vivo metabolism of EDP, a fully automated method using a solid-phase extraction (SPE) workstation connected on-line to a liquid chromatograph and a triple quadrupole mass analyzer (LC-MS/MS) was developed. The ensuing hyphenated method is very simple and requires minimal human intervention. Following thorough optimization of the SPE and LC-MS/MS conditions, the analytical procedure was validated and standard addition calibration used for the quantitative correction of matrix effects. The proposed method was applied to determine the phase I metabolites of EDP in urine samples and afforded limits of detection from 0.1 to 1.1 ng and accuracy of 91-107% with relative standard deviations in the range 1.5-8.7% (sample volume: 100 μL). Based on the results of in vivo percutaneous absorption of a single application of the sunscreen, about 0.5% of the amount of the applied EDP is excreted in urine.
