- Publikační typ
- abstrakt z konference MeSH
- Publikační typ
- abstrakt z konference MeSH
- Publikační typ
- abstrakt z konference MeSH
To follow the twelve "green analytical chemistry" (GAC) principles, it is necessary to continuously develop analytical extraction and determination methodologies to assess the presence of micropollutants, such as pharmaceuticals, in environmental samples. A reduction in the analysis time and solvent quantity, which is one of the GAC principles, has been achieved through a simplified solid-phase extraction (SPE) procedure combined with high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the determination of twenty-three pharmaceuticals in liquid environmental samples using N-vinylpyrrolidone-divinylbenzene copolymer (OASIS HLB) cartridges. The optimal SPE conditions were studied. In these optimized conditions, 82.6% of the data have a median recovery above 70% for all compounds in each sample. The relative standard deviations (RSDs) were below 14.4% and 22.0% for intra- and inter-day repeatability, respectively. Method detection limits (MDLs) and method quantification limits (MQLs) ranged from 0.011 to 188ngL(-1) and from 0.033 to 628ngL(-1), respectively. The applicability of the method was evaluated in real samples from natural and conventional wastewater treatment plants (WWTPs), and results were obtained in concentration ranges from 0.013 to 91.5μgL(-1) and from 0.004 to 49.1μgL(-1), respectively.
- MeSH
- chemické látky znečišťující vodu analýza izolace a purifikace MeSH
- chromatografie kapalinová MeSH
- extrakce na pevné fázi * MeSH
- léčivé přípravky analýza izolace a purifikace MeSH
- limita detekce MeSH
- monitorování životního prostředí metody MeSH
- odpadní voda chemie MeSH
- sladká voda chemie MeSH
- tandemová hmotnostní spektrometrie * MeSH
- Publikační typ
- časopisecké články MeSH
Elevated levels of pteridines can indicate the activation of cellular immune system by certain diseases. No work dealing with the simultaneous determination of urinary neopterin, biopterin and their reduced forms has been published. Therefore, a new SPE-UHPLC-FD method for the analysis of these compounds has been developed. The main emphasis was put on the stability of dihydroforms during the sample processing and storage. As a stabilizing agent, dithiothreitol, at various concentrations, and various pH values (3.8-9.8) of working solutions were tested. Chromatographic separation was performed under HILIC isocratic conditions on BEH Amide column. The method was linear for the calibration standard solutions in the range of 10-10,000 ng/ml (dihydroforms) and 0.5-1000 ng/ml (oxidized forms), and for real samples in the range of 25-1000 ng/ml (dihydroforms) and 1-100 ng/ml (oxidized forms). The development of a new SPE sample preparation method was carried out on different types of sorbents (based on a mixed-mode cation exchange, porous graphitic carbon and a polymer comprising hydrophilic and hydrophobic components). Final validation was performed on a MCAX SPE column. Method accuracy ranged from 76.9 to 121.9%. The intra- and inter-day precision did not exceed 10.7%. The method provided high sensitivity for the use in routine clinical measurements of urine (LLOQ 1 ng/ml for oxidized forms and 25 ng/ml for dihydroforms). Average concentrations of biopterin, neopterin, and dihydrobiopterin found in urine of healthy persons were related to the mol of creatinine (66.8, 142.3, and 257.3 μmol/mol of creatinine, respectively) which corresponded to the literature data. The concentration of dihydroneopterin obtained using our method was 98.8 μmol/mol of creatinine.
Mucosal-associated invariant T (MAIT) cells are innate-like T cells comprising up to 10% of the peripheral blood T cells in humans. During ontogeny, MAIT cells can first be detected in the cord blood in low amounts, but rise steadily after birth. In this population-based study, we show that their counts continue to increase, reaching maximal levels (4.5% of CD3(+) cells, 65 cells/μl) in the third and fourth decenniums. At this age, the amounts of MAIT cells exhibit the highest interindividual variability. The values then dramatically decline; subjects 80 years old and older have on average 10 times less MAIT cells, both absolutely and as a percentage among CD3(+) T cells, than subjects in fertile age. The senescence of MAIT cells is associated with decreased CD8/double negative (DN) ratio. Finally, we observed significantly higher amounts of MAIT cells in women of reproductive age than in men of the same age. Our data suggest that further studies aimed at elucidating a role of MAIT cells in human pathologies must recruit age- and gender-matched controls.
- MeSH
- antigeny CD3 biosyntéza MeSH
- CD8-pozitivní T-lymfocyty imunologie MeSH
- dítě MeSH
- dospělí MeSH
- imunologická paměť MeSH
- kojenec MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- novorozenec MeSH
- počet lymfocytů MeSH
- předškolní dítě MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- sliznice cytologie imunologie MeSH
- stárnutí imunologie MeSH
- T-lymfocyty - podskupiny imunologie MeSH
- věkové faktory MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- kojenec MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- novorozenec MeSH
- předškolní dítě MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Publikační typ
- abstrakt z konference MeSH
Pteridines are a group of endogenous heterocyclic compounds whose concentrations in biological fluids may be increased in some disorders, such as infections, autoimmune disorders and cancer. In particular, pteridine concentrations in urine may represent promising noninvasive markers. However, their specificity requires further investigation. Pteridines can occur in three oxidation states with different stability. In order to enable the analysis of the unstable di- and tetra-hydroforms either an oxidation (mainly with iodine) or stabilization by reducing agents is applied. Due to the high polarity of pteridines, many analytical procedures employed ion-pair, ion-exchange or hydrophilic interaction liquid chromatography using mostly fluorescence detection. In the last decade, MS was found to be applicable. The objective of this Review is to show possibilities and different approaches in pteridine analysis in biological samples.
- MeSH
- chromatografie kapalinová MeSH
- fluorescenční spektrometrie MeSH
- hmotnostní spektrometrie MeSH
- koncentrace vodíkových iontů MeSH
- lidé MeSH
- molekulární struktura MeSH
- oxidace-redukce MeSH
- pteridiny analýza krev chemie moč MeSH
- tělesné tekutiny chemie MeSH
- teplota MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Epigenetic de novo methylation of CpG islands is an important event in malignant transformation. Two genes are frequently methylated: cyclin-dependent kinase inhibitor 2B (CDKN2B) and cyclin-dependent kinase inhibitor 2A (CDKN2A). In our study methylation of these genes was studied in 63 patients with myelodysplastic syndromes (MDS), 2 with myelodysplastic/myeloproliferative neoplasms (MDS/MPN) and 13 with acute myeloid leukemia (AML). Five patients were monitored during 5-azacytidine treatment. Twenty-six healthy donors were tested in a control group. Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) method with all associated techniques was used for detection. Aberrant methylation was present in the CDKN2A gene in 38% and in the CDKN2B gene in 77% of the patients in MDS group. The level of methylation was higher in the group of AML patients - 77% in CDKN2A gene and 100% in CDKN2B gene. In MDS patients, an aberrant methylation was associated with a tendency to disease progression towards more advanced forms according to the World Health Organization (WHO) classification and the International Prognostic Scoring System (IPSS). Significant differences in methylation level were observed between early and advanced forms of MDS in CDKN2B gene (P value < 0.05) but not for CDKN2A gene. The trend of methylation in patients treated with azacitidine was analyzed in CDKN2B gene and correlated with the course of the disease. Increased methylation was connected with disease progression. We concluded that the methylation level of CDKN2B gene might be used as a marker of leukemic transformation in MDS. Our study indicates the role of hypermethylation as an important event in the progression of MDS to AML.
- MeSH
- akutní myeloidní leukemie genetika MeSH
- DNA genetika MeSH
- dospělí MeSH
- inhibitor p15 cyklin-dependentní kinasy genetika MeSH
- inhibitor p16 cyklin-dependentní kinasy genetika MeSH
- lidé středního věku MeSH
- lidé MeSH
- metylace DNA MeSH
- mladý dospělý MeSH
- myelodysplastické syndromy genetika MeSH
- nádorová transformace buněk genetika MeSH
- polymerázová řetězová reakce MeSH
- prognóza MeSH
- progrese nemoci MeSH
- senioři MeSH
- studie případů a kontrol MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- MeSH
- financování organizované MeSH
- Publikační typ
- abstrakty MeSH
