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Interferon-beta affects the tryptophan metabolism in multiple sclerosis patients
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
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2005 (English)In: European Journal of Neurology, ISSN 1351-5101, E-ISSN 1468-1331, Vol. 12, no 8, 625-631 p.Article in journal (Refereed) Published
Abstract [en]

Tryptophan and its metabolites are of great interest in understanding the pathogenesis of multiple sclerosis (MS). The total levels of tryptophan and its metabolites, kynurenine and kynurenic acid were determined in plasma by capillary liquid chromatography electrospray ionisation tandem mass spectrometry. This is the first report of the plasma levels of these analytes in healthy controls and relapsing-remitting MS patients receiving long-term and acute interferon-beta (IFN-beta) treatment. Twenty-four hours post-administration increased kynurenine levels (first IFN MS versus healthy, P = 0.042) and kynurenine/tryptophan ratio (K/T; first IFN MS versus healthy, P =0.027; first IFN MS versus long-term IFN MS, P = 0.036) were found. The long-term IFN MS group had higher K/T ratios at 4 and 12 h post-administration (P = 0.015 and 0.009, respectively). The increase of K/T ratio in the first IFN MS group indicate an induction of the enzyme indolamine-2,3-dioxygenase (IDO), as reported earlier in experimental allergic encephalomyelitis. As IDO is participating in both inflammatory and neurodegenerative processes, further knowledge of its involvement in the pathogenesis of MS is of great importance.

Place, publisher, year, edition, pages
2005. Vol. 12, no 8, 625-631 p.
Keyword [en]
electrospray ionisation, interferon-beta, kynurenic acid, kynurenine, mass spectrometry, multiple sclerosis, plasma, tryptophan
National Category
Medical and Health Sciences
URN: urn:nbn:se:uu:diva-96923DOI: 10.1111/j.1468-1331.2005.01041.xISI: 000230841800009OAI: oai:DiVA.org:uu-96923DiVA: diva2:171660
Available from: 2008-03-17 Created: 2008-03-17 Last updated: 2012-08-23Bibliographically approved
In thesis
1. Quantitative Bioanalysis: Liquid separations coupled to targeted mass spectrometric measurements of bioactive compounds
Open this publication in new window or tab >>Quantitative Bioanalysis: Liquid separations coupled to targeted mass spectrometric measurements of bioactive compounds
2008 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Performing quantitative analysis of targeted bioactive compounds in biological samples, such as blood plasma, cerebrospinal fluid or extracts from pig liver, put high demands on the ruggedness of the method acquiring the results. In addition to the complexity of the sample matrix, the bioactive compounds targeted for analysis usually have low levels of natural abundance, further increasing the demand on the analytical method sensitivity. Furthermore, quantitation of analytes at trace levels in the presence of large amounts of interfering species in biofluids must aim for repeatable precision, high accuracy ensuring the closeness to the true values, a linear response spanning over several orders of magnitude and low limits of quantitation to be valid for monitoring disease states in clinical analysis.

An analytical method most commonly follow a certain order of events, called the analytical chain, which includes; experimental planning, sampling, sample pre-treatment, separation of species, detection, evaluation, interpretation and validation, all equally important for the outcome of the results.

In this thesis, the scope has been to create novel methods, or to refine already existing methods, in order to achieve even better performances of the different events in the analytical chain.

One of the aspects has been to sample and enrich analytes in vivo by the use of solid supported microdialysis, giving the advantage of almost real-time monitoring of analyte levels within a living host with targeted selectivity due to the analyte affinity for solid particles. Another aspect to selectively clean and enrich analytes in a complex matrix has been developed and automated on-line by the use of a column-switching technique before the analytical separation. By using several steps of extraction and separation coupled on-line to selected detection by the use of a triple quadrupole mass spectrometer facilitates great selectivity of species. The mass spectrometer also gives the ability to distinguish between isotopically labelled analogues coeluting with the analytes yielding the necessary accuracy for quantitative evaluation.

Both development of analytical methods and clinical applications has been performed, as well as improvements of existing techniques, all to improve the quantitation of trace levels of targeted analytes in biofluids.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2008. 61 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 412
Analytical chemistry, Method development, Enhanced microdialysis, Column switching, Liquid chromatography, Capillary electrophoresis, Electrospray ionization, Mass spectrometry, Triple quadrupole, Time-of-flight, Quantitation, Validation, Analytisk kemi
National Category
Chemical Sciences
urn:nbn:se:uu:diva-8581 (URN)978-91-554-7135-4 (ISBN)
Public defence
2008-04-10, B22, BMC, Husargatan 3, Uppsala, 10:15 (English)
Available from: 2008-03-17 Created: 2008-03-17 Last updated: 2013-06-20Bibliographically approved

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