Validation of a liquid chromatography coupled to tandem mass spectrometry method for simultaneous quantification of tryptophan and 10 key metabolites of the kynurenine pathway in plasma and urine: Application to a cohort of acute kidney injury patients.

A sensitive and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of tryptophan (Trp) and ten metabolites of kynurenine pathway, including kynurenine (Kyn), 3-hydroxy-kynurenine (3-HK), kynurenic acid (KA), xanthurenic acid (XA), 3-Hydroxy-anthranilic acid (3-HANA), quinolinic acid (QA), nicotinic acid mononucleotide (NaMN), picolinic acid (Pic), nicotinamide (NAM) and nicotinic acid (NA) in both plasma and urine. This LC-MS/MS method was used to predict the occurrence of acute kidney injury (AKI) in a cohort of patients with cardiac surgery under cardiopulmonary bypass (CPB). Urinary concentrations of Pic, as well as Pic to Trp and Pic to 3-HANA ratios were highly predictive of an AKI episode the week after CPB, indicating that Pic could be a predictive biomarker of AKI.

Cutaneous adverse events in children treated with vemurafenib for refractory BRAF mutated Langerhans cell histiocytosis.

Background: The somatic BRAF mutation occurs in 38-64% of pediatric cases of Langerhans cell histiocytosis (LCH). Vemurafenib (VMF), a BRAF inhibitor, was approved for refractory BRAF mutated LCH. In adults, VMF causes frequent cutaneous adverse events (CAE) including skin tumors (squamous cell carcinomas, melanomas), but little is known in children.

Metabolic profiling of deschloro-N-ethyl-ketamine and identification of new target metabolites in urine and hair using human liver microsomes and high-resolution accurate mass spectrometry.

The aim of this study was to identify new markers of deschloro-N-ethyl-ketamine (O-PCE), a ketamine analogue that has been involved in acute intoxications with severe outcomes including death and whose metabolism has never been studied before. In vitro study after 2-h incubation with pooled human liver microsomes (HLMs) cross-checked by the analysis of urine and hair from a 43-year-old O-PCE user (male) were performed by liquid chromatography-high resolution mass spectrometry (LC-HRMS). Acquired data were processed by the Compound Discoverer® software, and a full metabolic profile of O-PCE was proposed.

Development and validation of liquid chromatography-tandem mass spectrometry targeted screening of 16 fentanyl analogs and U-47700 in hair: Application to 137 authentic samples.

This study was to validate a LC-MS/MS method for the determination of 17 new synthetic opioids (NSOs) in hair including 3-fluorofentanyl, 3-methylfentanyl, acetylfentanyl, acetylnorfentanyl, alfentanyl, butyrylfentanyl, butyrylnorfentanyl, carfentanil, fentanyl, furanylfentanyl, furanylnorfentanyl, methoxyacetylfentanyl, norcarfentanil, norfentanyl, ocfentanil, sufentanil, and U-47700, and to apply it to 137 authentic samples. Twenty milligrams of hair was decontaminated in dichloromethane and underwent liquid extraction. 10 μL of the reconstituted residue were injected onto the system.