We propose a simple and precise densitometric method for measuring vanillylmandelic acid (VMA). The method comprises direct urine application, thin-layer chromatographic (TLC) separation, postchromatographic derivatization, and in situ reading of the formed derivative at 560 nm. Quantitation was done by measuring peak area with a computer-controlled TLC Scanner and applying a five-point calibration function. The calibration function was 7.57-49.23 mumol/L. This method was used to determine urinary concentrations of excreted VMA; concentrations ranged from 4.84 to 56.06 mumol/day.
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J Med Case Rep
January 2025
Cardiovascular Surgery Department, Shahid Rajaee Hospital, Alborz University of Medical Sciences, Karaj, Iran.
Background: The coexistence of pheochromocytoma and hyperaldosteronism is a rare and clinically significant finding with diagnostic challenges that need to be considered in the workup of patients with hypertension.
Case Presentation: This case report describes a 47-year-old Iranian man who initially presented with cold symptoms, chills, and headaches. Despite being diagnosed with panic disorder, his symptoms worsened, leading to a systolic blood pressure crisis.
Int J Mol Sci
November 2024
Department of Pharmaceutical Chemistry, Medical University of Gdańsk, 80-416 Gdańsk, Poland.
The measurement of selected norepinephrine metabolites, such as 3,4-dihydroxyphenylglycol (DHPG), 3-methoxy-4-hydroxyphenylethylenglycol (MHPG), and vanillylmandelic acid (VMA), in biological matrices-including urine-is of great clinical importance for the diagnosis and monitoring of diseases. This fact has forced researchers to evaluate new analytical methodologies for their isolation and preconcentration from biological samples. In this study, the three most popular extraction techniques-liquid-liquid extraction (LLE), solid-phase extraction (SPE), and a new 3D-printed system for dispersive solid-phase extraction (3D-DSPE)-were investigated.
View Article and Find Full Text PDFClin Chim Acta
January 2025
Medical-Scientific Department, LifeLabs Medical Laboratory Services, Toronto, ON M9W 6J6, Canada. Electronic address:
Chem Commun (Camb)
November 2024
College of Chemistry and Materials Engineering, College of life and environmental science, Wenzhou University, Key Lab of Biohealth Materials and Chemistry of Wenzhou, Wenzhou 325035, China.
A 14-metal Tb(III) nanocluster with four CO anions as templates was constructed for the quantitative and qualitative detection of vanillylmandelic acid (VMA) with high sensitivity and selectivity. The luminescence response time to VMA is less than ten seconds, and the limit of detection is as low as 0.32 nM in CHCN.
View Article and Find Full Text PDFMetabolomics
November 2024
Department of Biomedical Sciences, College of Health Sciences, QU Health, Qatar University, Doha, Qatar.
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