Urinary nucleosides

Determination of Urinary Nucleosides as Potential Cancer Markers Using High Petformance Liquid Chromatography with Tandem Mass Spectrometry... 

Stmck, W., Siluk, D., Yumba-Mpanga, A., Markuszewski, M., Kaliszan, R., Markuszewski, M.J. Liquid chromatography tandem mass spectrometry study of urinary nucleosides as potential cancer markers. J. Chromatogr. A 1283, 122-131 (2013)... 

Urinary excretion of modified nncleosides, originating from tiansfer-RNA, may be nsed as a biomarker for tnmonrs and AIDS. Dudley et al. [54-57] reported method development for the analysis of urinary nucleosides by LC-MS. Initially, LC-MS conditions were optimized [54]. In positive-ion ESI-MS, detection limits were achieved ranging from 7 pmol for tubercidin to 110 pmol for uridine. Next, a comparison was made between GC-MS, LC-MS on an ion-trap instrament, and capillary LC-MS on a triple-quadmpole instmment [55]. These methods proved complementary rather than that just one could be selected as optimal. Therefore, in the next study [56], all three techniques were applied to identily the unexpected 5 -deoxycytidine in the urine of a patient suffering with head and neck cancer. In another study [57], they demonstrated the detection of dA, 1-methyl-dA, xanthosine, 7V-l-methyl-dG, 7V-2-methyl-dG, 7V-2,7V-2-dimethyl-dG, A-2,7V-2,A-7-trimethyl-dG, inosine, and 1-methylinosine in urine samples from various cancer patients. 

E. Dudley, S. El-Sharkawi, D. E. Games, R.P. Newton, Analysis of urinary nucleosides. I. Optimisation of LC-ESI-MS, Rapid Commun. Mass Spectrom., 14 (2000) 1200. 

In Szymanska et al. (45), PCA was performed on electrophoretic data of urinary nucleoside profiles, in order to distinguish profiles of healthy controls from cancer patients. Prior to PCA, the data were preprocessed using baseline correction, COW, and normalization according to creatinine concentration. After adequate preprocessing, PCA allowed us to reveal data structure and to evaluate differences between the healthy controls and the cancer patient profiles. 

Sz5mianska E, et al. Evaluation of different warping methods for the analysis of CE profiles of urinary nucleosides. Electrophoresis 2007 28 2861-2873. 

Szymanska, E. Markuszewski, M.J. Bodzioch, K. Kaliszan, R. Development and validation of urinary nucleosides and creatinine assay by capillary electrophoresis with solid phase extraction. J. Pharm. Biomed. Anal. 2007, 44, 1118-1126. 

The levels of 13 urinary nucleosides (e.g., dihydrouridine, pseudouridine, 1-methyladenosine, inosine, guanosine, 5 -deoxy-5 -methylthioadenosine) were monitored at 260 nm and 280 nm using a 30°C column and a 40-min 100/0 40/60... 

Normal and modified urinary nucleosides were monitored on a 30°C C g column (A = 260 nm and 280 nm) using a complex 30-min 100/0 - 40/60 water (25 mM KH2PO4 at pH 4.7)/(60/40 methanol/water) gradient [440]. Out of tire 16 compounds monitored (e.g., uridine, 6-methyladenosine, 5-methyluridine, 2-methyl-guanosine, xanthosine) four compounds (pseudouridine, 1-methyladenosine, 3-methyluridine, 1-methylinosine) were clearly elevated-concentration markers for cancer. Standard concentrations ran fix>m 1 to 4pM. Overall resolution was exceptional as were peak shapes. 

G. Schbch, J. Thomale, H. Lorenz, H. Suberg, U. Karsten A new method for the simultaneous analysis of unmodified and modified urinary nucleosides and nucleobases by high performance liquid chromatography. Clin. Chim. Acta 108 247 (1980). 

Zhao, R., Xu, G., Yue, B., Lieblich, H.M., Zhang, Y., Artificial neural network classification based on capillary electrophoresis of urinary nucleosides for the clinical diagnosis of tumors. J. Chromatogr. A, 828, 489-496 (1998). 

The nucleoside formed from hypoxanthine and ribose is known as inosine (Ino or I) and the corresponding nucleotide as inosinic acid. Further substitution at C-2 of -H by -OH and tautomerization yields xanthine (Xan). Its nucleoside is xanthosine (Xao, X). A similar hydroxylation at C-7 converts xanthine to uric acid, an important human urinary excretion product derived from nucleic acid bases. 

As far as quantitative chemical derivatization GC analysis is concerned, it is necessary to mention especially the work of Gehrke and his collaborators, who specified the fundamental concepts of quantitative GC analysis combined with the chemical derivatization of sample compounds and applied them to the accurate determination of the twenty natural protein amino acids and other non-protein amino acids as their N-TFA-n-butyl esters [5 ], the urinary excretion level of methylated nucleic acid bases as their TMS derivatives [6], TMS nucleosides [7] and other investigations. Further examples include a computer program for processing the quantitative GC data obtained for seventeen triglyceride fatty acids after their transesterification by 2 NKOH in n-butanol [8], a study of the kinetics of the transesterification reactions of dimethyl terephthalate with ethylene glycol [9] and the GC-MS determination of chlorophenols in spent bleach liquors after isolation of the chlorophenols by a multi-step extraction, purification of the final extract by HPLC and derivatization with diazoethane [10]. 

G. J. Dear, I. M. Ismail, P. J. Mutch, R. S. Plumb, L. H. Davies, and B. C. Sweatman, Urinary metabolites of a novel quinoxaline non-nucleoside reverse transcriptase inhibitor in rabbit, mouse and human Identification of fluorine NIH shift metabolites using NMR and tandem Xenobiotica 30 (2000), 407 26. 

CM-induces intrarenal hypoxia, possibly related to the hemodynamic changes and/or increased tubular energy expenditure in response to osmotic stress [33]. It has been proposed that increased renal adenosine levels arising from enhanced ATP hydrolysis may be a major contributor to development of acute renal failure after CM apphcation (Figure 1). This is corroborated by the finding that apphcation of CM increases urinary adenosine excretion [44, 45] and the observation that dipyridamol, a nucleoside uptake blocker, magnifies the renal hemodynamic effects of CM [44, 45]. In addition, there are many similarities between... 

Occurrence In small amounts in muscles, liver, urinary calculi, beet juice, barley shoots, fly agarics, peanut kernels, potatoes, yeasts, coffee beans, tea leaves. X. is formed in the metabolism of higher animals by deamination of guanine (component of nucleic acid) or oxidation of hypoxanthine by xanthine oxidase present in muscles which then also oxidizes X. further to uric acid, the final product of the purine metabolism in humans. The nucleoside derived from X. is xanthosine. Although X. is chemically closely related to "caffein(e) and other methylxanthines, its activity is different. Stimulation of the central nervous system is less pronounced, the paralyzing effects dominate, and cardiac muscles are severely damaged. 

Simmonds, H.A., Sahota, A., Potter, C.F., Cameron, J.S. Purine metabolism and immunodeficiency urinary purine excretion as a diagnostic screening test in adenosine deaminase and purine nucleoside phosphorylase deficiency. Clin. Sci. and Molec. Med. 54 579-584 (1978). 

A difficulty in finding inborn errors of pyrimidine metabolism by metabolite screening procedures is the absence of a typical end-product, like uric acid is in the purine metabolism. Moreover, pyrimidine metabolism is not easily accessible for simple chromatographic screening techniques. Nevertheless, with more complicated methods we are able to evaluate patterns of urinary pyrimidine bases and nucleosides. With routine gas-liquid chromatography (GLC) as is used for urinary organic acid analysis strongly increased uracil and thymine concentrations can be discovered. 

S.K. Wadman, P.K. de Bree, A.H. van Gennip, J.W. Stoop, B.J.M. Zegers and G.E.J. Staal, Urinary purines in a patient with a severely defective T cell immunity and a purine nucleoside phos-phorylase deficiency, "Purine Metabolism in Man-II regulation of pathways and enzyme defects", M.M. Muller, E. Kaiser and J.E. Seegmiller, Plenum Publishing Corporation, New York (1977) pp 471-477. 

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