0000000000070151
AUTHOR
Dace Hartmane
Metformīna noteikšana bioloģiskajos paraugos ar šķidrumu hromatogrāfijas-masspektrometrijas metodi
Metformīna noteikšana bioloģiskajos paraugos ar šķidrumu hromatogrāfijas-masspektrometrijas metodi. Hartmane. D., zinātniskie vadītāji: Dr. chem. Grīnberga S., asoc. prof., Dr. chem. Mekšs P. Maģistra darbs, 61 lappuse, 25 attēli, 5 tabulas, 46 literatūras avoti, 2 pielikumi. Latviešu valodā. Darbā ir apkopota literatūra par matricas efekta ietekmi, bioloģisko paraugu sagatavošanu un metformīna kvantitatīvo noteikšanu ar šķidrumu hromatogrāfijas metodēm. Izstrādāta hromatogrāfijas-tandēmmasspektrometrijas metode kvantitatīvai metformīna noteikšanai cilvēku bioloģiskajos paraugos. Metode validēta metformīna noteikšanai plazmas un eritrocītu paraugos. Metode pielietota metformīna satura notei…
Loop diuretics decrease the renal elimination rate and increase the plasma levels of trimethylamine‐N‐oxide
Aims Trimethylamine-N-oxide (TMAO) is a novel cardiovascular risk marker. We explored the association of commonly used cardiovascular medications with TMAO levels in patients and validated the identified associations in mice. Methods Detailed history of drug treatment was recorded in 300 patients with cardiovascular disease without diabetes in an observational, cross-sectional study. Animal study was performed in CD1 mice. Results Median plasma TMAO (interquartile range) level was 2.144 (1.570-3.104) μmol l-1 . Among nine cardiovascular drug groups, the use of loop diuretics (0.510 ± 0.296 in users vs. 0.336 ± 0.272 in nonusers, P = 0.008) and mineralocorticoid receptor antagonists (0.482 ±…
Diabetes is Associated with Higher Trimethylamine N-oxide Plasma Levels
Recent studies have revealed strong associations between systemic trimethylamine N-oxide (TMAO) levels, atherosclerosis and cardiovascular risk. In addition, plasma L-carnitine levels in patients with high TMAO concentrations predicted an increased risk for cardiovascular disease and incident major adverse cardiac events. The aim of the present study was to investigate the relation between TMAO and L-carnitine plasma levels and diabetes. Blood plasma samples were collected from 12 and 20 weeks old db/db mice and patients undergoing percutaneous coronary intervention. Diabetic compared to non-diabetic db/L mice presented 10-fold higher TMAO, but lower L-carnitine plasma concentrations at 12 …
Determination of trimethylamine-N-oxide in combination withl-carnitine andγ-butyrobetaine in human plasma by UPLC/MS/MS
An ultra-high-performance liquid chromatography-mass spectrometry (UPLC/MS/MS) method was developed and validated for the quantification of trimethylamine-N-oxide (TMAO) simultaneously with TMAO-related molecules L-carnitine and γ-butyrobetaine (GBB) in human blood plasma. The separation of analytes was achieved using a Hydrophilic interaction liquid chromatography (HILIC)-type column with ammonium acetate-acetonitrile as the mobile phase. TMAO determination was validated according to valid US Food and Drug Administration guidelines. The developed method was successfully applied to plasma samples from healthy volunteers.
CntA oxygenase substrate profile comparison and oxygen dependency of TMA production in Providencia rettgeri.
CntA oxygenase is a Rieske 2S-2Fe cluster-containing protein that has been previously described as able to produce trimethylamine (TMA) from carnitine, gamma-butyrobetaine, glycine betaine, and in one case, choline. TMA found in humans is exclusively of bacterial origin, and its metabolite, trimethylamine oxide (TMAO), has been associated with atherosclerosis and heart and renal failure. We isolated four different Rieske oxygenases and determined that there are no significant differences in their substrate panels. All three had high activity toward carnitine/gamma-butyrobetaine, medium activity toward glycine betaine, and very low activity toward choline. We tested the influence of low oxyg…