Background: Cystinosis is a rare autosomal recessive disorder characterized by an accumulation of intralysosomal cystine due to a defect in cystine transport across the lysosomal membrane. This disorder can be treated specifically using high doses of cysteamine. Accurate measurement of intracellular cystine content is necessary for the diagnosis and monitoring of treatment with cysteamine. Here we describe a new method to measure intracellular cystine. It relies on a liquid chromatography-tandem mass spectrometry assay. We compare this novel method with the cystine-binding protein assay.
Method: Cells were isolated and lysed in the presence of N-ethylmaleimide to avoid interference from cysteine. After deproteinization, addition of stable isotope d6 cystine and butylation, cystine was measured using an API 3000 MSMS.
Results: The cystine assay was linear to at least 50 micromol/L. Within-run and between-run coefficients of variation were 2.9% and 5.7% respectively.
Conclusion: It is possible to measure very low concentrations of intracellular cystine with liquid chromatography-tandem mass spectrometry. The results obtained with this novel method correlate very well with those obtained using the cystine-binding protein assay.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.clinbiochem.2007.02.005 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Serum metabolomic signatures of patients with rare neurogenetic diseases: an insight into potential biomarkers and treatment targets.
Front Mol Neurosci
January 2025
Interdisciplinary Centre for Innovations in Biotechnology and Neuroscience, Faculty of Medical Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka.
Introduction: To further advance our understanding of Muscular Dystrophies (MDs) and Spinocerebellar Ataxias (SCAs), it is necessary to identify the biological patterns associated with disease pathology. Although progress has been made in the fields of genetics and transcriptomics, there is a need for proteomics and metabolomics studies. The present study aimed to be the first to document serum metabolic signatures of MDs (DMD, BMD, and LGMD 2A) SCAs (SCA 1-3), from a South Asian perspective.
View Article and Find Full Text PDFToxicological evaluation, postmortem case descriptions, and pharmacological activity of N,N-dimethylpentylone and related analogues.
J Anal Toxicol
January 2025
Center for Forensic Science Research and Education, Fredric Rieders Family Foundation, Horsham, PA.
Identification of N,N-dimethylpentylone (DMP) in counterfeit "Ecstasy" and "Molly" tablets poses risk to public health due to its adverse effects. Little information is available regarding the pharmacological activity or relevant blood or tissue concentrations of DMP, and even less is known about other structurally related beta-keto methylenedioxyamphetamine analogues on recreational drug markets, such as N-propyl butylone. Here, a novel toxicological assay utilizing liquid chromatography-tandem quadrupole mass spectrometry (LC-QQQ-MS) was developed and validated for the quantitation of DMP and five related synthetic cathinones (eutylone, pentylone, N-ethyl pentylone (NEP), N-propyl butylone, and N-cyclohexyl butylone), with chromatographic resolution from isomeric variants and quantitation performed by standard addition.
View Article and Find Full Text PDFEffect of High-Fat Diets on the Pharmacokinetics of Bedaquiline Fumarate Tablet: A Trial in Healthy Chinese Participants.
Clin Pharmacol Drug Dev
January 2025
Department of Clinical Research Center, Central Hospital Affiliated to Shandong First Medical University, Jinan, China.
Bedaquiline is employed to treat multidrug-resistant and extensive drug-resistant tuberculosis by inhibiting the proton pump of adenosine triphosphate synthase in Mycobacterium tuberculosis. This study aims to investigate the effect of high-fat diets on the pharmacokinetics of bedaquiline through a single-center, open-label, randomized trial in healthy Chinese participants. Bedaquiline fumarate tablets were administered at a dosage of 100 mg under both fasted conditions and high-fat diet conditions.
View Article and Find Full Text PDFDetermination of 115 Pesticide Residues in Textiles by Liquid Chromatography-Tandem Mass Spectrometry.
Rapid Commun Mass Spectrom
May 2025
Technology Center of Qingdao Customs, Qingdao, China.
The presence of pesticide residues in textiles poses a risk to human health. We established a robust and high-throughput liquid chromatography-tandem mass spectrometry method for the determination of 115 pesticide residues in textiles. In this study, we evaluated high-performance liquid chromatography-tandem mass spectrometry conditions and sample extraction methods, including separation performance of different columns, mass conditions, extraction solvent, and extraction time.
View Article and Find Full Text PDFEndogenous sex hormone levels are associated with the revised Framingham Stroke Risk Profile in postmenopausal women: a longitudinal study in a Swedish cohort.
BMC Endocr Disord
January 2025
Family medicine, School of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Box 454, Göteborg, 40530, Sweden.
Background: Endogenous sex hormones in postmenopausal women have been associated with risk of cardiovascular diseases. The aim of this study was to determine the association between endogenous sex hormones and the revised Framingham Stroke Risk Profile (rFSRP) in postmenopausal women.
Methods: This is an observational cross-sectional study on the Vara-Skövde cohort, a Swedish population-based study for longitudinal surveillance of the development and progress of type 2 diabetes and hypertension.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!