xii, 165 s. : il. + 1 CD-ROM
- MeSH
- Biochemistry methods MeSH
- Spectrometry, Mass, Electrospray Ionization methods MeSH
- Clinical Laboratory Techniques MeSH
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods MeSH
- Publication type
- Monograph MeSH
- Conspectus
- Biochemie. Molekulární biologie. Biofyzika
- NML Fields
- chemie, klinická chemie
- biochemie
Hledání optimálního nastavení podmínek chemické analýzy je zpravidla zdlouhavý proces. Tento článek k tomuto účelu navrhuje využití neuronových sítí, zejména ve vztahu k určení optimální podmínek pro analýzu zkoumaných látek s využitím technologie LC/MS/MS a ESI ionizací, a to na základě znalosti jejich základních vlastností, označených jako univerzální deskriptory. Práce se soustředí na nalezení takových podmínek analýzy, kdy dochází k maximalizaci signálu iontu prekurzoru. Práce se zabývá zejména otázkou, zda lze výsledky zjištěné na jednom typu analytu použít k neurální interpolační predikci optimálních podmínek analytů podobných.
The search for the optimal instrumental settings of conditions in chemical analysis is typically a lengthy process. This article proposes the use of neural networks for this purpose, particularly in relation to determining the optimal conditions for the analysis of substances under study using LC/MS/MS and ESI technologies, based on the knowledge of their fundamental properties, referred to as universal descriptors. The work focuses on finding such analysis conditions that maximize the precursor ion signal. The paper specifically addresses the question of whether the results obtained from one type of analyte can be used for neural-interpolated prediction of optimal conditions for similar analytes.
- MeSH
- Chemical Warfare Agents chemistry MeSH
- Chemistry Techniques, Analytical methods MeSH
- Chromatography, Liquid methods MeSH
- Spectrometry, Mass, Electrospray Ionization methods MeSH
- Mass Spectrometry methods MeSH
- Humans MeSH
- Neural Networks, Computer MeSH
- Organophosphates * chemistry analysis MeSH
- Check Tag
- Humans MeSH
A LC-MS method for determination of muscarine and amatoxins in urine and blood serum was developed and validated. The analysis was carried out using an LC/MS quadrupole device equipped with electrospray. The separation of muscarine, -amanitin, -amanitin, phalloidin and phallacidin was performed on analytical columns in the gradient mode. The applicability of the method has been demonstrated by analyzing clinical samples.
Cíle studie: Cílem této studie je sledování vzájemného vztahu plasmatických hladin imatinibu s jeho denní dávkou a časovým intervalem od poslední užité dávky u pacientů s chronickou myeloidní leukemií na terapii imatinibem. Chronická myeloidní leukemie (CML) je myeloproliferativní onemocnění charakteristické přítomností chromozomu Philadelphia a leukemického fúzního genu BCR-ABL vedoucího k expresi konstitutivně aktivní tyrosinkinázy zodpovědné za maligní transformaci. Největší úspěšnost v léčbě byla zaznamenána prostřednictvím cílených inhibitorů vzniklého onkoproteinu, proto je dnes imatinib používán jako lék první linie. Terapeutické monitorování plasmatických hladin imatinibu u pacientů s CML je důležitým nástrojem k optimalizaci a individualizaci léčby. Typ studie: Klinická Materiál a metody: V naší studii jsme analyzovali soubor 1790 vzorků od 168 pacientů s CML na terapii imatinibem. Veškerá měření byla provedena metodou kapalinové chromatografie ve spojení s tandemovou hmotnostní spektrometrií v rámci rutinního vyšetřování plasmatických hladin tyrosinkinázových inhibitorů. Denní dávka imatinibu s pohybovala v rozmezí 100 až 800 mg; vzorky byly odebrány 1–120 hodin od poslední užité dávky. Výsledky a závěr: Analýza výsledků odhalila významnou korelaci plasmatické hladiny imatinibu s jeho denní dávkou (R2 = 0,075) a časovým intervalem od poslední užité dávky (R2 = 0,177). Z celého souboru bylo vybráno 616 vzorků odebraných 24±4 hodiny od poslední dávky od 111 pacientů s denní dávkou 400 mg imatinibu a byla stanovena inter- (48 %) a intraindividuální (36 %) variabilita.
Objective: The aim of the study is monitoring of correlation of imatinib plasma levels with daily dose and sampling time in patients with chronic myeloid leukemia on imatinib therapy. Chronic myeloid leukemia (CML) is myeloproliferative disorder characterized by the presence of chromozome Philadelphia and leukemic fusion gene BCR-ABL leading expression of constitutively active tyrosin kinase responsible for malignant transformation. The most successful treatment was recorded via targeted inhibitors of generated oncoprotein and therefore imatinib is used as a first-line treatment, today. Therapeutic monitoring of imatinib plasma levels in patients with chronic myeloid leukemia is important tool for treatment individualization. Design: Clinical Materials and methods: In our study we have analyzed a group of 1790 samples from 168 patients with CML on imatinib therapy. All measurements were performed by the liquid chromatography coupled with tandem mass spectrometry method within routine monitoring of plasmatic levels of tyrosin kinase inhibitors. Imatinib daily dose vary from 100 to 800 mg and samples were obtained 1 - 120 hours after last drug administration. Results and conclusion: Analysis of the results revealed correlation between imatinib plasma level and daily dose (R2 = 0.075) or with sampling time (R2 = 0.177). From whole data file 616 samples taken 24±4 hours after last drug administration from 111 patients with imatinib daily dose 400 mg were chosen and inter- (48 %) and intraindividual (36 %) variability were determined.
- MeSH
- Drug Resistance, Neoplasm * MeSH
- Chromatography, Liquid MeSH
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive * diagnosis MeSH
- Humans MeSH
- Drug Monitoring MeSH
- Proto-Oncogene Proteins c-bcr MeSH
- Tandem Mass Spectrometry MeSH
- Protein-Tyrosine Kinases * antagonists & inhibitors MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
Byla zavedena a validována jednoduchá metoda s použitím kapalinové chromatografie a tandemové hmotnostní spektrometrie (LC-MS/MS) pro stanovení kolistinu A a kolistinu B v plazmě. Extrakce proteinů z plazmy byla provedena pomocí 1 ml kazet Oasis HLB a chromatografická separace byla provedena na koloně Arion® Polar C18 (250 × 4,6 mm; 5 mm) při 35 °C. Mobilní fáze se skládala z vody obsahující 0,1 % kyseliny mravenčí a methanolu obsahujícího 0,1 % kyseliny mravenčí v poměru 40 : 60 (v/v), při průtoku 0,8 ml/minutu. Eluent byl detekován v režimu pozitivních iontů pomocí ionizace elektrosprejem s následujícími iontovými přechody m/z: kolistin A 585,55 → 101,05; kolistin B 578,5 → 101,15; a IS 602,4 → 101,1; 120,15; 86,15. Byly provedeny testy krátkodobé stability kolistinu a CMS, a to při pokojové teplotě a 37 °C, kdy se stabilita obou složek se zvyšující se teplotou snižuje. Předložený příspěvek je součástí studie Pharmacokinetics of Colistin in Critically Ill Patients With Extracorporeal Membrane Oxygenation (COL-ECMO2022), v níž budou prezentovány další výsledky.
A simple liquid chromatography tandem mass spectrometry (LC-MS/MS) assay for the determination of colistin A and colistin B in human plasma was developed and validated. Plasma extraction was performed using Oasis HLB 1 ml cartridges, analysis was performed using Arion® Polar C18 (250×4,6mm; 5mm) column at 35°C. Mobile phases consisted of water containing 0,1% formic acid and methanol containing 0,1% formic acid (40:60, v/v) delivered at a flow rate of 0,8 ml/minute. Eluent was detected in the positive ion mode using electrospray ionization at the following transitions of mass to charge (m/z): colistin A 585,55 → 101,05; colistin B 578,5 → 101,15; and IS 602,4 → 101,1; 120,15; 86,15. Short-term stability tests of colistin and CMS were performed, at room temperature and 37°C, where the stability of both components decreases with increasing temperature. The presented paper is part of the Pharmacokinetics of Colistin in Critically Ill Patients With Extracorporeal Membrane Oxygenation (COL-ECMO2022) study in which further results will be presented.
- MeSH
- Chemistry Techniques, Analytical * methods instrumentation MeSH
- Chromatography, Liquid methods instrumentation MeSH
- Hydrolysis MeSH
- Colistin * blood MeSH
- Humans MeSH
- Mesylates blood MeSH
- Protein Stability MeSH
- Statistics as Topic MeSH
- Tandem Mass Spectrometry MeSH
- Check Tag
- Humans MeSH
- Publication type
- Clinical Study MeSH
- Research Support, Non-U.S. Gov't MeSH
Saxitoxins (STXs) are potent neurotoxins produced by marine dinoflagellates or freshwater cyanobacteria known to cause acute and eventually fatal human intoxications, which are classified as paralytic shellfish poisonings (PSPs). Rapid analysis of STXs in blood plasma can be used for a timely diagnosis and confirmation of PSPs. We developed a fast and simple method of STX extraction based on plasma sample acidification and precipitation by acetonitrile, followed by quantification using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Our approach provides the results ≤30 min, with a limit of detection of 2.8 ng/mL and a lower limit of quantification of 5.0 ng/mL. Within-run and between-run precision experiments showed good reproducibility with ≤15% values. Standard curves for calibration were linear with correlation coefficients ≥0.98 across the assay calibration range (5-200 ng/mL). In an interlaboratory analytical exercise, the method was found to be 100% accurate in determining the presence or absence of STX in human plasma specimens, with recovery values of 86-99%. This simple method for STX determination in animal or human plasma can quickly and reliably diagnose STX exposures and confirm suspected PSP cases to facilitate patient treatment or expedite necessary public health or security actions.
Microflow liquid chromatography interfaced with mass spectrometry (μLC-MS/MS) is increasingly applied for high-throughput profiling of biological samples and has been proven to have an acceptable trade-off between sensitivity and reproducibility. However, lipidomics applications are scarce. We optimized a μLC-MS/MS system utilizing a 1 mm inner diameter × 100 mm column coupled to a triple quadrupole mass spectrometer to establish a sensitive, high-throughput, and robust single-shot lipidomics workflow. Compared to conventional lipidomics methods, we achieve a ∼4-fold increase in response, facilitating quantification of 351 lipid species from a single iPSC-derived cerebral organoid during a 15 min LC-MS analysis. Consecutively, we injected 303 samples over ∼75 h to prove the robustness and reproducibility of the microflow separation. As a proof of concept, μLC-MS/MS analysis of Alzheimer's disease patient-derived iPSC cerebral organoid reveals differential lipid metabolism depending on APOE phenotype (E3/3 vs E4/4). Microflow separation proves to be an environmentally friendly and cost-effective method as it reduces the consumption of harmful solvents. Also, the data demonstrate robust, in-depth, high-throughput performance to enable routine clinical or biomedical applications.
- MeSH
- Apolipoproteins E MeSH
- Chromatography, Liquid methods MeSH
- Phenotype MeSH
- Liquid Chromatography-Mass Spectrometry * MeSH
- Humans MeSH
- Lipidomics MeSH
- Reproducibility of Results MeSH
- Tandem Mass Spectrometry * methods MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The success of bottom-up proteomic analysis frequently depends on the efficient removal of contaminants from protein or peptide samples before LC-MS/MS. For a peptide clean-up workflow, single-pot solid-phase-enhanced peptide sample preparation on carboxylate-modified paramagnetic beads (termed SP2) was evaluated for sodium dodecyl sulfate or polyethylene glycol removal from Arabidopsis thaliana tryptic peptides. The robust and efficient 40-min SP2 protocol, tested for 10-ng, 250-ng, and 10-μg peptide samples, was proposed and benchmarked thoroughly against the ethyl acetate extraction protocol. The SP2 protocol on carboxylated magnetic beads proved to be the most robust approach, even for the simultaneous removal of massive sodium dodecyl sulfate (SDS) and polyethylene glycol (PEG) contaminations from AT peptide samples in respect of the LC-MS/MS data outperforming ethyl acetate extraction.
The precise and unambiguous detection and quantification of internal RNA modifications represents a critical step for understanding their physiological functions. The methods of direct RNA sequencing are quickly developing allowing for the precise location of internal RNA marks. This detection is, however, not quantitative and still presents detection limits. One of the biggest remaining challenges in the field is still the detection and quantification of m6A, m6Am, inosine, and m1A modifications of adenosine. The second intriguing and timely question remaining to be addressed is the extent to which individual marks are coregulated or potentially can affect each other. Here, we present a methodological approach to detect and quantify several key mRNA modifications in human total RNA and in mRNA, which is difficult to purify away from contaminating tRNA. We show that the adenosine demethylase FTO primarily targets m6Am marks in noncoding RNAs in HEK293T cells. Surprisingly, we observe little effect of FTO or ALKBH5 depletion on the m6A mRNA levels. Interestingly, the upregulation of ALKBH5 is accompanied by an increase in inosine level in overall mRNA.
- MeSH
- Adenosine * analogs & derivatives metabolism genetics analysis MeSH
- AlkB Homolog 5, RNA Demethylase * metabolism genetics MeSH
- Chromatography, Liquid methods MeSH
- Alpha-Ketoglutarate-Dependent Dioxygenase FTO * metabolism genetics MeSH
- HEK293 Cells MeSH
- Inosine * metabolism genetics MeSH
- Liquid Chromatography-Mass Spectrometry MeSH
- Humans MeSH
- RNA, Messenger * genetics metabolism MeSH
- RNA Processing, Post-Transcriptional MeSH
- Tandem Mass Spectrometry * methods MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
OBJECTIVE: The laboratory diagnosis of inherited metabolic disorders (IMD) has undergone significant development in recent decades, mainly due to the use of mass spectrometry, which allows rapid multicomponent analysis of a wide range of metabolites. Combined with advanced software tools, the diagnosis becomes more efficient as a benefit for both physicians and patients. METHODS: A hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry assay for determination of urinary purines, pyrimidines, N-acylglycines, N-acetylated amino acids, sugars, sugar alcohols and other diagnostically important biomarkers was developed and validated. Evaluation of the results consisting of utilisation of robust scaling and advanced visualization tools is simple and even suitable for urgent requirements. RESULTS: The developed method, covering 65 biomarkers, provides a comprehensive diagnostic platform for 51 IMD. For most analytes, linearity with R2 > 0.99, intra and inter-day accuracy between 80 and 120 % and precision lower than 20 % were achieved. Diagnostic workflow was evaluated on 47 patients and External Quality Assurance samples involving a total of 24 different IMD. Over seven years, more than 2300 urine samples from patients suspected for IMD have been routinely analysed. CONCLUSIONS: This method offers the advantage of a broad coverage of intermediate metabolites of interest and therefore may be a potential alternative and simplification for clinical laboratories that use multiple methods for screening these markers.
- MeSH
- Biomarkers urine MeSH
- Chromatography, Liquid methods MeSH
- Liquid Chromatography-Mass Spectrometry MeSH
- Humans MeSH
- Metabolic Diseases * MeSH
- Tandem Mass Spectrometry * methods MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
