scholarly journals Identification and Determination of 1,3-Thiazinane-4-carboxylic Acid in Human Urine—Chromatographic Studies

2022 ◽  
Vol 23 (2) ◽  
pp. 598
Author(s):  
Justyna Piechocka ◽  
Natalia Litwicka ◽  
Rafał Głowacki
Keyword(s):  
Carboxylic Acid ◽  
Human Urine ◽  
Clinical Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Aqueous Environment ◽  
Limit Of Quantification ◽  
Isobutyl Chloroformate ◽  
United States Food ◽  
States Food

It is well established that homocysteine (Hcy) and its thiolactone (HTL) are reactive towards aldehydes in an aqueous environment, forming substituted thiazinane carboxylic acids. This report provides evidence that Hcy/HTL and formaldehyde (FA) adduct, namely 1,3-thiazinane-4-carboxylic acid (TCA) is formed in vivo in humans. In order to provide definitive proof, a gas chromatography–mass spectrometry (GC–MS) based method was elaborated to identify and quantify TCA in human urine. The GC–MS assay involves chemical derivatization with isobutyl chloroformate (IBCF) in the presence of pyridine as a catalyst, followed by an ethyl acetate extraction of the obtained isobutyl derivative of TCA (TCA-IBCF). The validity of the method has been demonstrated based upon United States Food and Drug Administration recommendations. The assay linearity was observed within a 1–50 µmol L−1 range for TCA in urine, while the lowest concentration on the calibration curve was recognized as the limit of quantification (LOQ). Importantly, the method was successfully applied to urine samples delivered by apparently healthy volunteers (n = 15). The GC–MS assay may provide a new analytical tool for routine clinical analysis of the role of TCA in living systems in the near future.

scholarly journals 2-(3-Hydroxy-5-phosphonooxymethyl-2-methyl-4-pyridyl)-1,3-thiazolidine-4-carboxylic Acid, Novel Metabolite of Pyridoxal 5′-Phosphate and Cysteine Is Present in Human Plasma—Chromatographic Investigations

2020 ◽  
Vol 21 (10) ◽  
pp. 3548 ◽  
Author(s):  
Justyna Piechocka ◽  
Monika Wrońska ◽  
Iwona E. Głowacka ◽  
Rafał Głowacki
Keyword(s):  
Carboxylic Acid ◽  
Human Plasma ◽  
Vitamin B6 ◽  
Active Form ◽  
Aqueous Environment ◽  
Breast Cancer Patients ◽  
Limit Of Quantification ◽  
Apparently Healthy

It is well-established that aminothiols, to which cysteine (Cys) belongs, are highly reactive towards aldehydes in an aqueous environment, forming substituted thiazolidine carboxylic acids. This report provides evidence that formation of the product containing a thiazolidine ring through non-enzymatic condensation of Cys and an active form of vitamin B6 pyridoxal 5′-phosphate (PLP) occurs in vivo in humans. To prove this point, a new method, based on a gas chromatography coupled with mass spectrometry (GC-MS), has been designed to identify and quantify Cys and PLP adduct, 2-(3-hydroxy-5-phosphonooxymethyl-2-methyl-4-pyridyl)-1,3-thiazolidine-4-carboxylic acid (HPPTCA) in human plasma. The GC-MS assay relies on sample deproteinization by ultrafiltration over cut-off membranes and preconcentration by drying under vacuum, followed by treatment of the residue with derivatization mixture containing anhydrous pyridine, N-trimethylsilyl-N-methyl trifluoroacetamide (MSTFA) and trimethylchlorosilane (TMCS). The method quantifies HPPTCA in a linear range from 1 to 20 µmol L−1, where the lowest standard on the calibration curve refers to the limit of quantification (LOQ). The validity of the method was demonstrated. Furthermore, the method was successfully applied to plasma samples donated by apparently healthy volunteers and breast cancer patients. The GC-MS assay provides a new tool that will hopefully facilitate studies on the role of HPPTCA in living systems.

THE IN VIVO METABOLISM OF CORTISOL AND CORTICOSTERONE BY THE MACAQUE MONKEY (Macaca fascicularis)

1975 ◽  
Vol 78 (1) ◽  
pp. 91-109 ◽  
Author(s):  
K. D. R. Setchell ◽  
C. H. L. Shackleton
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Adult Female ◽  
Human Urine ◽  
Macaca Fascicularis ◽  
Macaque Monkey ◽  
The Other ◽  
Gas Chromatography Mass Spectrometry ◽  
In Vivo Metabolism

ABSTRACT [4-14C] Cortisol was administered intramuscularly to one adult female macaque monkey, MF3 (Macaca fascicularis). To adult female macaque monkey, MF4, [4-14C]corticosterone was administered intramuscularly. Urine samples were collected and the metabolites excreted identified using gas chromatography, radio-gas chromatography and gas chromatography-mass spectrometry. The principal metabolites of cortisol were identified as glucuronide conjugates of 11-oxygenated-17-oxosteroids. The excretion of tetrahydrocortisol and tetrahydrocortisone relative to the other corticosteroid metabolites was low compared with that of man. Two compounds, 3β-cortol and 3β-cortolone not normally present in human urine were identified in the urine from this species. The principal metabolites of corticosterone were glucuronide conjugates of hexahydroCompound A and hexahydrocorticosterone. Two unidentified radioactive compounds were also present.

scholarly journals Validation of a Gas Chromatography-Mass Spectrometry Method for the Measurement of the Redox State Metabolic Ratios Lactate/Pyruvate and β-Hydroxybutyrate/Acetoacetate in Biological Samples

2021 ◽  
Vol 22 (9) ◽  
pp. 4752
Author(s):  
Robin Wijngaard ◽  
Meritxell Perramón ◽  
Marina Parra-Robert ◽  
Susana Hidalgo ◽  
Gina Butrico ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Redox State ◽  
Gas Chromatography Mass Spectrometry ◽  
Spectrometry Method ◽  
Limit Of Quantification ◽  
Experimental Conditions ◽  
Mass Spectrometry Method ◽  
Chromatography Mass Spectrometry

The metabolic ratios lactate/pyruvate and β-hydroxybutyrate/acetoacetate are considered valuable tools to evaluate the in vivo redox cellular state by estimating the free NAD+/NADH in cytoplasm and mitochondria, respectively. The aim of the current study was to validate a gas-chromatography mass spectrometry method for simultaneous determination of the four metabolites in plasma and liver tissue. The procedure included an o-phenylenediamine microwave-assisted derivatization, followed by liquid-liquid extraction with ethyl acetate and silylation with bis(trimethylsilyl)trifluoroacetamide:trimethylchlorosilane 99:1. The calibration curves presented acceptable linearity, with a limit of quantification of 0.001 mM for pyruvate, β-hydroxybutyrate and acetoacetate and of 0.01 mM for lactate. The intra-day and inter-day accuracy and precision were within the European Medicines Agency’s Guideline specifications. No significant differences were observed in the slope coefficient of three-point standard metabolite-spiked curves in plasma or liver and water, and acceptable recoveries were obtained in the metabolite-spiked samples. Applicability of the method was tested in precision-cut liver rat slices and also in HepG2 cells incubated under different experimental conditions challenging the redox state. In conclusion, the validated method presented good sensitivity, specificity and reproducibility in the quantification of lactate/pyruvate and β-hydroxybutyrate/acetate metabolites and may be useful in the evaluation of in vivo redox states.

scholarly journals A simplified approach for determination of urinary ethyl glucuronide by gas chromatography–mass spectrometry

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shayani Ghosh ◽  
Raka Jain ◽  
Satpal Singh ◽  
Ravindra Rao ◽  
Ashwani Kumar Mishra ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Human Urine ◽  
Impact Ionization ◽  
Limit Of Detection ◽  
Extraction Procedure ◽  
Ethyl Glucuronide ◽  
Gas Chromatography Mass Spectrometry ◽  
Limit Of Quantification ◽  
Chromatography Mass Spectrometry

AbstractUrinary ethyl glucuronide (EtG), an alcohol biomarker, plays an essential role in monitoring alcohol abstinence and relapse during treatment for alcohol dependence. Detection of this biomarker has become a routine in many clinical and forensic laboratories over the last few years. Most previously published methods commonly use hyphenated chromatographic techniques along with extensive extraction procedure before analysis. This work aimed to develop and validate an electron impact ionization mode gas chromatography–mass spectrometry method to measure ethyl glucuronide levels in human urine. For its determination, urine samples were dried under a gentle stream of nitrogen, derivatized with N,O-bis(trimethylsilyl) trifluoroacetamide, incubated, and injected into the instrument. The analysis was performed using single quadrupole gas chromatography–mass spectrometry (GC-MS) technology and validation was performed according to the guidelines of the German Society of Toxicology and Forensic Chemistry (GTFCh). The linearity of urinary EtG was obtained in the range of 30–5000 ng/ml with a correlation coefficient (r) above 0.999. The extraction recoveries exceeded 80%, and the obtained inter-day and intra-day precisions were below 15%. The achieved limit of detection was 10 ng/ml and limit of quantification achieved was 30 ng/ml. The electron ionization gas chromatography–mass spectrometry technique proves to be a feasible option for determining EtG in human urine when other sophisticated techniques are unapproachable. This method provides a good sensitivity and proves to be cost-effective, robust, and advantageous for both clinical as well as forensic settings.

scholarly journals Determination of Morphine and Codeine in Human Urine by Gas Chromatography-Mass Spectrometry

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Xiaoqian Zhang ◽  
Mengchun Chen ◽  
Gaozhong Cao ◽  
Guoxin Hu
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Human Urine ◽  
Forensic Identification ◽  
Gas Chromatography Mass Spectrometry ◽  
Linear Calibration ◽  
Selected Ion Monitoring ◽  
Limit Of Quantification ◽  
Chromatography Mass Spectrometry

A sensitive and selective gas chromatography-mass spectrometry (GC-MS) method was developed and validated for the determination of morphine and codeine in human urine. The GC-MS conditions were developed. The analysis was carried out on a HP-1MS column (30 m × 0.25 mm, 0.25 μm) with temperature programming, and Helium was used as the carrier gas with a flow rate of 1.0 mL/min. Selected ion monitoring (SIM) mode was used to quantify morphine and codeine. The derivation solvent, temperature, and time were optimized. A mixed solvent of propionic anhydride and pyridine (5 : 2) was finally used for the derivation at 80°C for 3 min. Linear calibration curves were obtained in the concentration range of 25–2000.0 ng/mL, with a lower limit of quantification of 25 ng/mL. The intra- and interday precision (RSD) values were below 13%, and the accuracy was in the range 87.2–108.5%. This developed method was successfully used for the determination of morphine and codeine in human urine for forensic identification study.

Soluble Thrombomodulin Purified from Human Urine Exhibits a Potent Anticoagulant Effect In Vitro and In Vivo

1995 ◽  
Vol 73 (05) ◽  
pp. 805-811 ◽  
Author(s):  
Yasuo Takahashi ◽  
Yoshitaka Hosaka ◽  
Hiromi Niina ◽  
Katsuaki Nagasawa ◽  
Masaaki Naotsuka ◽  
...  
Keyword(s):  
Human Urine ◽  
Specific Activity ◽  
Anticoagulant Activity ◽  
Rabbit Lung ◽  
Soluble Thrombomodulin ◽  
Molecular Weights ◽  
Dose Dependent Fashion ◽  
Dose Dependent

SummaryWe examined the anticoagulant activity of two major molecules of soluble thrombomodulin purified from human urine. The apparent molecular weights of these urinary thrombomodulins (UTMs) were 72,000 and 79,000, respectively. Both UTMs showed more potent cofactor activity for protein C activation [specific activity >5,000 thrombomodulin units (TMU)/mg] than human placental thrombomodulin (2,180 TMU/mg) and rabbit lung thrombomodulin (1,980 TMU/mg). The UTMs prolonged thrombin-induced fibrinogen clotting time (>1 TMU/ml), APTT (>5 TMU/ml), TT (>5 TMU/ml) and PT (>40 TMU/ml) in a dose-dependent fashion. These effects appeared in the concentration range of soluble thrombomodulins present in human plasma and urine. In the rat DIC model induced by thromboplastin, administration of UTMs by infusion (300-3,000 TMU/kg) restored the hematological abnormalities derived from DIC in a dose-dependent fashion. These results demonstrate that UTMs exhibit potent anticoagulant and antithrombotic activities, and could play a physiologically important role in microcirculation.

Delirium Secondary to Lamotrigine Toxicity

2020 ◽  
Vol 15 (2) ◽  
pp. 156-159 ◽  
Author(s):  
Deborah L. Sanchez ◽  
Adam J. Fusick ◽  
Steven R. Gunther ◽  
Michael J. Hernandez ◽  
Gregory A. Sullivan ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
Valproic Acid ◽  
Mental Status ◽  
The United States ◽  
Clinical Correlation ◽  
Medication Regimen ◽  
Medication Effects ◽  
United States Food ◽  
States Food ◽  
Rule Out

Background: Lamotrigine is a phenyltriazine medication that has been approved by the United States Food and Drug Administration as monotherapy and as an adjunctive agent for the treatment of seizure disorder. It was later approved by the FDA for the treatment of bipolar disorder. Lamotrigine is generally well tolerated by patients, but some serious symptoms can occur during treatment. These severe side effects include rashes and multi-organ failure. Lamotrigine has also been associated with the development of mental status changes, frequently when used concurrently with other medications that may impact the metabolism of lamotrigine. Objective: To present the case of a 65-year-old man being treated with lamotrigine and valproic acid who developed mental status changes after the addition of sertraline to his medication regimen, and to compare this case to existing cases reported in the literature. Discussion: Our case adds to the existing literature by demonstrating that patients may experience adverse medication effects despite lamotrigine levels that are normally considered to be in the therapeutic range, highlighting the importance of clinical correlation when obtaining medication levels. Conclusion: Clinicians should use caution interpreting lamotrigine levels when working up delirium, as normal levels may not rule out the development of lamotrigine toxicity.

scholarly journals mRNA-Driven Generation of Transgene-Free Neural Stem Cells from Human Urine-Derived Cells

Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1043 ◽  
Author(s):  
Phil Jun Kang ◽  
Daryeon Son ◽  
Tae Hee Ko ◽  
Wonjun Hong ◽  
Wonjin Yun ◽  
...  
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Human Urine ◽  
Neurological Disorders ◽  
Therapeutic Potential ◽  
Embryonic Stem ◽  
Global Gene Expression ◽  
Patient Specific ◽  
Human Neural Stem Cells

Human neural stem cells (NSCs) hold enormous promise for neurological disorders, typically requiring their expandable and differentiable properties for regeneration of damaged neural tissues. Despite the therapeutic potential of induced NSCs (iNSCs), a major challenge for clinical feasibility is the presence of integrated transgenes in the host genome, contributing to the risk for undesired genotoxicity and tumorigenesis. Here, we describe the advanced transgene-free generation of iNSCs from human urine-derived cells (HUCs) by combining a cocktail of defined small molecules with self-replicable mRNA delivery. The established iNSCs were completely transgene-free in their cytosol and genome and further resembled human embryonic stem cell-derived NSCs in the morphology, biological characteristics, global gene expression, and potential to differentiate into functional neurons, astrocytes, and oligodendrocytes. Moreover, iNSC colonies were observed within eight days under optimized conditions, and no teratomas formed in vivo, implying the absence of pluripotent cells. This study proposes an approach to generate transplantable iNSCs that can be broadly applied for neurological disorders in a safe, efficient, and patient-specific manner.

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