Changes in methotrexate polyglutamate concentration in patients with rheumatoid arthritis during treatment and after discontinuation (review of two cases)

2021 ◽  
pp. 35-37
Author(s):  
G. I. Gridneva ◽  
E. S. Aronova ◽  
E. Yu. Samarkina
Keyword(s):  
Rheumatoid Arthritis ◽  
Mass Spectrometry ◽  
Adverse Reactions ◽  
Routine Clinical Practice ◽  
Gas Chromatography Mass Spectrometry ◽  
Therapeutic Drug ◽  
The Past ◽  
Target Values ◽  
Methotrexate Polyglutamate ◽  
Long Chain

Introduction. The dynamics of changes in the concentration of polyglutamates of methotrexate (MTPG) over the past 20 years has been studied by several scientifc groups using various methods. For a number of reasons, the results of these studies cannot be called uniform and cannot be confdently projected onto the Russian population of patients with rheumatoid arthritis (RA). At the same time, therapeutic drug monitoring of methotrexate (MT) with clearly defned target values of metabolites could be an extremely useful tool in routine clinical practice.Purpose of the study. To characterize the concentration of MTPG in dynamics during treatment and 12 weeks after discontinuation of MT.Materials and methods. Two patients with early RA were traced 4, 12, 24 weeks after MT appointment, and also 12 weeks after its cancellation due to nausea that appeared during treatment. At each visit, an analysis was made for MTPG content by tandem gas chromatography-mass spectrometry.Results. Against the background of treatment, the signifcantly predominant metabolite was MTPG with three and gour residues of glutamic acid (the so-called long-chain), while 12 weeks after discontinuation, MTPG 2 was the predominant fraction.Conclusions. Low values of MTPG 3 and MTPG 4 with high values of MTPG 2 may indicate a recent initiation of treatment or MTB cancellation within the next 3 months. In the event of subjective adverse reactions (ADRs), it is advisable to consider the possibility of switching to a drug analogue of another manufacturer.

Estradiol-17 beta determined in plasma by gas chromatography-mass spectrometry with selected ion monitoring of mixed silyl ether-perfluoroacyl ester derivatives and use of various stable-isotope-labeled internal standards.

1989 ◽  
Vol 35 (4) ◽  
pp. 532-536 ◽  
Author(s):  
L Dehennin
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Stable Isotope ◽  
Trimethylsilyl Ether ◽  
Gas Chromatography Mass Spectrometry ◽  
Specific Method ◽  
Silyl Ether ◽  
Selected Ion Monitoring ◽  
Chromatography Mass Spectrometry ◽  
Target Values

Abstract A highly specific method is described for measuring estradiol-17 beta (E2) in plasma by gas chromatography-mass spectrometry (GC-MS) associated with stable isotope dilution. A mixed derivative, E2-3-trimethylsilyl ether-17-heptafluorobutyrate (E2-3-TMS-17-HFB), was found to have excellent analytical properties. The specificity of the derivatization procedure exploits a unique feature of estrogens: the selective exchange of a phenolic perfluoroacyl ester for a trialkylsilyl ether. No significant differences in E2 concentration could be ascribed to the use of 2H- or 13C-labeled analogs, thus ruling out interferences from possible isotope exchange commonly attributed to deuterated compounds. Precision is closely similar to that for methods in which the more common E2-3, 17-bis(trimethylsilyl) ether and E2-3, 17-bis(heptafluorobutyrate) derivatives are used. Sensitivity and specificity of the mixed 3-TMS-17-HFB derivative allow adequate determinations of E2, even in plasma from males, in 2-mL samples. Interlaboratory mean concentrations of E2 obtained by routine immunoassays were consistently higher than the target values estimated by GC-MS, particularly at concentrations less than 100 pmol/L.

Phytochemical Screening, Isolation, and Structure Elucidation of the Radish (Raphanus sativus Linn.) Bulb Ethanolic Extract Using Gas Chromatography- Mass Spectrometry (GC-MS)

10.17158/233 ◽  
2012 ◽  
Vol 18 (1) ◽  
Author(s):  
Ma. Eva C. San Juan ◽  
Ramchand S. Jumala ◽  
Karen Hope G. Niasca
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Raphanus Sativus ◽  
Ethanolic Extract ◽  
Bioactive Molecules ◽  
Gas Chromatography Mass Spectrometry ◽  
Phytochemical Analysis ◽  
Phytochemical Screening ◽  
Chromatography Mass Spectrometry ◽  
Long Chain

Nowadays, plant is being used as a biofuel, a probable source for a pesticide and it is valued for its pharmacological effects. Hence, the researchers engaged in the scientific approach to provide explanation to these claims. The study focused on the phytochemical screening of the ethanolic extract of radish bulbs (Raphanus sativus). It further dealt on the isolation and determination of the molecular masses to provide probable structures and associated molecular properties for its constituents.<br />Alkaloids, flavonoids, saponins and tannins were analyzed. Further, this effort involved analysis through Thin Layer Chromatography (TLC) using the mobile phase of Toluene: Chloroform (9:11) and Gas Chromatography- Mass Spectrometry (GC-MS) to analyze the first spot (Retention Factor= 0.667).<br />Phytochemical analysis showed no tannins. Using TLC, it revealed two spots having Rf values of 0.667 and 0.507, respectively. Using GC-MS method, 24 different molecules were isolated and analyzed of which only 23 were given probable structures. The 23 molecules constituted 11 long-chain alkanes, 4 long-chain alkyl esters, 2 aromatic ketones, a benzyl halide, an aryl ether, a quinone, an aromatic aldehyde, a long chain aromatic alkane, and a long-chain alkyl nitrile. With this finding, the bulb extract may be a good source of potential biofuel (mono-alkyl ester), UV A, B and C blockers in the form of diphenyl-ketone, oviposition attractants (long-chain alkanes) and also a source of bioactive molecules such as estragole which shows antispasmodic effect, methyl palmitate with immunosuppressive effect in semi-allografts and hepatoprotective activity in rats, and an analogue of the antidepressant alfetamine.

3-Hydroxydicarboxylic and 3-ketodicarboxylic aciduria in three patients: evidence for a new defect in fatty acid oxidation at the level of 3-ketoacyl-CoA thiolase

1993 ◽  
Vol 39 (5) ◽  
pp. 897-901 ◽  
Author(s):  
M J Bennett ◽  
W G Sherwood
Keyword(s):  
Mass Spectrometry ◽  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Mass Spectra ◽  
Gas Chromatography Mass Spectrometry ◽  
Acid Oxidation ◽  
Fatty Acid Oxidation Disorder ◽  
Urinary Organic Acids ◽  
First Time ◽  
Long Chain

Abstract Three patients presented with evidence of a fatty acid oxidation disorder. Analysis of urinary organic acids by gas chromatography/mass spectrometry demonstrated the presence of medium-chain (C6-C12) dicarboxylic, 3-hydroxydicarboxylic, and 3-ketodicarboxylic acids in all three urines. 3-Ketodicarboxylic aciduria is reported for the first time here, as are the mass spectra for 3-ketosuberic, 3-ketosebacic, and 3-ketododecanedioic acids and the oximated spectrum for 3-ketoadipic acid. The presence of 3-ketodicarboxylic acids suggests a defect at the level of a long-chain 3-ketoacyl-CoA thiolase, an enzyme for which a deficiency state has not previously been described. Our patients may represent the first cases of a long-chain thiolase defect.

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