Quantification of a mercapturate metabolite of the biocides methylisothiazolinone and chloromethylisothiazolinone (“M-12”) in human urine using online-SPE-LC/MS/MS

2021 ◽  
Vol 13 (15) ◽  
pp. 1847-1856
Author(s):  
Thomas Schettgen ◽  
Jens Bertram ◽  
Till Weber ◽  
Thomas Kraus ◽  
Marike Kolossa-Gehring
Keyword(s):  
General Population ◽  
Human Urine ◽  
Urine Samples ◽  
Online Spe ◽  
First Report ◽  
M 12

A first report on a urinary mercapturate metabolite of the biocides methylisothiazolinone and chloromethylisothiazolinone in urine samples of the general population.

The influence of taurine and L-carnitine on 6 β-hydroxycortisol/cortisol ratio in human urine of healthy volunteers

2019 ◽  
Vol 34 (3) ◽  
Author(s):  
Anna A. Makhova ◽  
Eugenia V. Shikh ◽  
Tatiana V. Bulko ◽  
Zhanna M. Sizova ◽  
Victoria V. Shumyantseva
Keyword(s):  
Catalytic Activity ◽  
Healthy Volunteers ◽  
Human Urine ◽  
Biologically Active Compounds ◽  
Biologically Active ◽  
Metabolic Ratio ◽  
Urine Samples ◽  
Cyp3a4 Activity ◽  
Active Compounds ◽  
Cortisol Ratio

Abstract Background Cytochrome P450s (CYPs, EC 1.14.14.1) are the main enzymes of drug metabolism. The functional significance of CYPs also includes the metabolism of foreign chemicals and endogenic biologically active compounds. The CYP3A4 isoform contributes to the metabolism of about half of all marketed medicinal preparations. The aim of this study was to investigate the effects of two biologically active compounds: 2-aminoethane-sulfonic acid (taurine) and 3-hydroxy-4-trimethylaminobutyrate (L-carnitine) on urinary 6β-hydroxycortisol/cortisol (6β-OHC/cortisol) metabolic ratio as a biomarker of the CYP3A4 activity of healthy volunteers. Taurine is used for the treatment of chronic heart failure and liver disease. Cardiologists, nephrologists, neurologists, gerontologists in addition to the main etiopathogenetic therapies, use L-carnitine. The quantification of the 6β-OHC/cortisol metabolic ratio as a biomarker of CYP3A4 activity in human urine was used for the assessment of CYP3A4 catalytic activity as a non-invasive test. Methods The study included 18 healthy male volunteers (aged from 18 to 35 years old). The volunteers took taurine in a dose of 500 mg twice a day or L-carnitine in a dose of 2.5 mL 3 times a day for 14 consecutive days. The test drug was given 20 min before meals. The collection of urine samples was performed before and after 3, 7, 10, and 14 days after taurine intake. The metabolic ratio of 6β-OHC/cortisol in morning spot urine samples was studied by the liquid chromatography/mass spectroscopy (LC/MS) method. Results The ratio of 6-6β-OHC/cortisol was used as a biomarker to study the taurine and L-carnitine influence on CYP3A4 metabolism of cortisol. The ratio of urinary 6β-OCH/cortisol in the morning urine samples of volunteers before the beginning of taurine therapy (baseline ratio) was 2.71 ± 0.2. Seven days after the administration of taurine in a dose of 500 mg twice a day, the 6β-OCH/cortisol ratio was 3.3 ± 0.2, which indicated the increased catalytic activity of CYP3A4 towards cortisol. As for the L-carnitine supplementation, analysis of the 6β-OCH/cortisol ratio in the urine for 14 days did not show any significant changes in this baseline ratio, indicating the lack of L-carnitine influence on the catalytic activity of CYP3A4 to cortisol. Conclusions The results obtained demonstrated the influence of taurine on 6β-OCH/cortisol metabolic ratio as a biomarker of CYP3A4 catalytic activity to cortisol. L-carnitine did not affect the activity of CYP3A4. The lack of a clinically meaningful effect of L-carnitine was established.

scholarly journals Dried urine spots as sampling technique for multi-mycotoxin analysis in human urine

2021 ◽  
Author(s):  
Jessica Schmidt ◽  
Viktoria Lindemann ◽  
Monica Olsen ◽  
Benedikt Cramer ◽  
Hans-Ulrich Humpf
Keyword(s):  
Ochratoxin A ◽  
Human Urine ◽  
Sampling Strategy ◽  
Sampling Technique ◽  
Human Biomonitoring ◽  
Urine Samples ◽  
Isotope Dilution Analysis ◽  
Tenuazonic Acid ◽  
Stable Isotope Dilution Analysis ◽  
Mycotoxin Analysis

AbstractA simple and effective approach for HPLC-MS/MS based multi-mycotoxin analysis in human urine samples was developed by application of dried urine spots (DUS) as alternative on-site sampling strategy. The newly developed method enables the detection and quantitation of 14 relevant mycotoxins and mycotoxin metabolites, including citrinin (CIT), dihydrocitrinone (DH-CIT), deoxynivalenol (DON), fumonisin B1 (FB1), T-2 Toxin (T-2), HT-2 Toxin (HT-2), ochratoxin A (OTA), 2′R-ochratoxin A (2′R-OTA), ochratoxin α (OTα), tenuazonic acid and allo-tenuazonic acid (TeA + allo-TeA), zearalenone (ZEN), zearalanone (ZAN), α-zearalenol (α-ZEL), and β-zearalenol (β-ZEL). Besides the spotting procedure, sample preparation includes enzymatic cleavage of glucuronic acid conjugates and stable isotope dilution analysis. Method validation revealed low limits of detection in the range of pg/mL urine and excellent apparent recovery rates for most analytes. Stability investigation of DUS displayed no or only slight decrease of the analyte concentration over a period of 28 days at room temperature. The new method was applied to the analysis of a set of urine samples (n = 91) from a Swedish cohort. The four analytes, DH-CIT, DON, OTA, and TeA + allo-TeA, could be detected and quantified in amounts ranging from 0.06 to 0.97 ng/mL, 3.03 to 136 ng/mL, 0.013 to 0.434 ng/mL and from 0.36 to 47 ng/mL in 38.5%, 70.3%, 68.1%, and 94.5% of the samples, respectively. Additional analysis of these urine samples with an established dilute and shoot (DaS) approach displayed a high consistency of the results obtained with both methods. However, due to higher sensitivity, a larger number of positive samples were observed using the DUS method consequently providing a suitable approach for human biomonitoring of mycotoxin exposure.

scholarly journals Stanozolol‐ N ‐glucuronide metabolites in human urine samples as suitable targets in terms of routine anti‐doping analysis

2021 ◽  
Author(s):  
Lorenz Göschl ◽  
Günter Gmeiner ◽  
Peter Gärtner ◽  
Georg Stadler ◽  
Valentin Enev ◽  
...  
Keyword(s):  
Human Urine ◽  
Urine Samples ◽  
Doping Analysis ◽  
Human Urine Samples

scholarly journals The colorimetric and microfluidic paper-based detection of cysteine and homocysteine using 1,5-diphenylcarbazide-capped silver nanoparticles

RSC Advances ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 3295-3303 ◽  
Author(s):  
Sattar Shariati ◽  
Gholamreza Khayatian
Keyword(s):  
Silver Nanoparticles ◽  
Human Urine ◽  
Quantitative Measurement ◽  
Urine Samples ◽  
Human Urine Samples

A simple and novel portable method for the quantitative measurement of cysteine and homocysteine in human urine samples is presented.

scholarly journals Analytical and physiological validation of an enzyme immunoassay to measure oxytocin in dog, wolf, and human urine samples

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
G. Wirobski ◽  
F. S. Schaebs ◽  
F. Range ◽  
S. Marshall-Pescini ◽  
T. Deschner
Keyword(s):  
Enzyme Immunoassay ◽  
Human Urine ◽  
Extraction Efficiency ◽  
Urine Samples ◽  
Antibody Specificity ◽  
Analytical Validation ◽  
Human Urine Samples ◽  
Assay Performance ◽  
Fit For Purpose ◽  
Commercial Enzyme Immunoassay

AbstractOxytocin (OT) promotes pro-sociality, bonding, and cooperation in a variety of species. Measuring oxytocin metabolite (OTM) concentrations in urine or saliva provides intriguing opportunities to study human and animal behaviour with minimal disturbance. However, a thorough validation of analytical methods and an assessment of the physiological significance of these measures are essential. We conducted an analytical validation of a commercial Enzyme Immunoassay (EIA; Arbor OT assay kit) to measure OTM concentrations in dog, wolf, and human urine samples. To test the assay’s ability to detect changes in OTM concentrations, we administered oxytocin intranasally to 14 dogs. Assay performance with regard to parallelism was acceptable. Assay accuracy and extraction efficiency for dog and wolf samples were comparable to a previously validated assay (Enzo OT assay kit) but variation was smaller for human samples. Binding sensitivity and antibody specificity were better in the Arbor assay. Average OTM concentrations were more than twice as high as in comparable samples measured with the Enzo assay, highlighting a lack of comparability of absolute values between different assays. Changes in OTM concentrations after intranasal treatment were detected reliably. The Arbor assay met requirements of a “fit-for-purpose” validation with improvement of several parameters compared to the Enzo assay.

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