The reported method allows for a simple and rapid monitoring of DNA replication and cell cycle progression in eukaryotic cells in vitro. The DNA of replicating cells is labeled by incorporation of a metabolically-active fluorescent (Cy3) deoxyuridine triphosphate derivative, which is delivered into the cells by a synthetic transporter (SNTT1). The cells are then fixed, stained with DAPI and analyzed by flow cytometry. Thus, this protocol obviates post-labeling steps, which are indispensable in currently used incorporation assays (BrdU, EdU). The applicability of the protocol is demonstrated in analyses of cell cycles of adherent (U-2 OS, HeLa S3, RAW 264.7, J774 A.1, Chem-1, U-87 MG) and suspension (CCRF-CEM, MOLT-4, THP-1, HL-60, JURKAT) cell cultures, including those affected by a DNA polymerase inhibitor (aphidicolin). Owing to a short incorporation time (5-60 min) and reduced number of steps, the protocol can be completed within 1-2 h with a minimal cell loss and with excellent reproducibility.
- MeSH
- barvení a značení metody MeSH
- bromodeoxyuridin aplikace a dávkování MeSH
- buněčný cyklus * MeSH
- DNA analýza MeSH
- fluorescenční barviva aplikace a dávkování MeSH
- HeLa buňky MeSH
- HL-60 buňky MeSH
- Jurkat buňky MeSH
- karbocyaniny aplikace a dávkování MeSH
- lidé MeSH
- průtoková cytometrie metody MeSH
- replikace DNA * MeSH
- reprodukovatelnost výsledků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Allantoin is an excellent biomarker of oxidative stress in humans as the main product of uric acid oxidation by reactive oxygen species. Yet, allantoin determination is still not routinely performed in clinical laboratories. Therefore, we developed a fast, simple, selective, and sensitive UHPLC-MS/MS method for allantoin determination in human serum using an isotopically labeled internal standard. Our analytical protocol provided high sensitivity by mass spectrometry detection and high throughput by HILIC-MS/MS analysis within 4 min, with one-step serum sample preparation approximately within 7 min. Lastly, our protocol was fully validated to demonstrate its reliability in allantoin determination in human serum. The method showed an excellent linear range from 0.05 to 100 μM, with precision ranging from 1.8 to 11.3% (RSD), and with accuracy (relative error %) within ±6.0%. The method was then applied to analyze the concentration of allantoin in serum samples from 71 patients with chronic gout without treatment with xanthine oxidase inhibitors. The median serum allantoin concentration in the cohort was 2.8 μM (n = 71). Overall, our simple analytical protocol has the potential to be easily implemented in clinical routine practice for monitoring allantoin as a key oxidative stress biomarker.
- MeSH
- alantoin krev MeSH
- biologické markery krev MeSH
- chronická nemoc MeSH
- dna (nemoc) metabolismus MeSH
- kohortové studie MeSH
- lidé MeSH
- oxidační stres MeSH
- tandemová hmotnostní spektrometrie metody MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- validační studie MeSH
Nucleic acid aptamers are single-stranded (ss)DNA or RNA oligonucleotides that can take various conformations and bind specifically and with high affinity to selected targets. While the introduction of SELEX (systematic evolution of ligands by exponential enrichment) revolutionized the production of the aptamers, this procedure is impeded by the formation of undesirable by-products reflecting hybridization among complementary oligonucleotides in the ssDNA libraries during asymmetric PCR. To reduce nonspecific amplification we tested cellulose-derived compounds and found that sodium carboxymethylcellulose (CMC) at a concentration 0.05%-0.2% efficiently suppressed production of undesirable large DNA amplicons during asymmetric PCR in the course of SELEX. Formation of the PCR by-products was reduced by CMCs of low and medium viscosity more than by CMCs of high viscosity, and all of them bound to DNA oligonucleotides as determined by electrophoresis in agarose gels. In contrast to CMC, methylcellulose did not reduce the formation of the PCR by-products and did not bind to DNA. DNA aptamers selected in the presence of CMC could be used directly in enzyme-linked immunosorbent-like assay. The combined data suggest that CMC binds weekly to DNA oligonucleotides through hydroxyl groups and in this way inhibits low-affinity DNA-DNA hybridization and enhances the production of specific amplicons in asymmetric PCR.
- MeSH
- aptamerová technika SELEX metody MeSH
- aptamery nukleotidové chemie MeSH
- ELISA metody MeSH
- jednovláknová DNA chemie MeSH
- methylcelulosa chemie MeSH
- polymerázová řetězová reakce metody MeSH
- sodná sůl karboxymethylcelulosy chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The assessment of the stability of biomarkers is very important for epidemiological studies. In this study, the stability of five lipid parameters (total cholesterol, triglycerides, HDL- and LDL-cholesterol and free fatty acids) has been tested in 16 human serum samples after storage at -80 °C up at time points 0, 1, 8 and 13 y. The majority of the lipid biomarkers were stable during storage conditions, except for cholesterol. The correlations between the samples were very good at time points. Therefore, long-term storage of human serum samples allows lipid biomarker determination, provided that the samples are stored at -80 °C.
- MeSH
- biologické markery krev MeSH
- cholesterol krev MeSH
- dospělí MeSH
- HDL-cholesterol krev MeSH
- LDL-cholesterol krev MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- triglyceridy krev MeSH
- zdraví dobrovolníci pro lékařské studie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The main objective of this study was to develop an effective in-gel trypsin digestion protocol using aqueous-acetonitrile solvent system to facilitate MS analysis and maximize the number of identified proteins from biological samples. The procedure, where 80% acetonitrile was present in the trypsin reaction mixture, increased the number of matched peptides, and allowed the identification of more proteins with higher coverage than the common digestion protocol. Vimentin, annexins, tubulin, actin, peptidyl-prolyl cis-trans isomerase or alpha-enolase are examples of important proteins that change during the progress cancer. These were isolated from human breast cancer cells and were used for this study.
- MeSH
- acetonitrily chemie MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nádorové proteiny analýza izolace a purifikace metabolismus MeSH
- nádory metabolismus patologie MeSH
- peptidy analýza MeSH
- proteomika metody MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
- trypsin metabolismus MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Human serum albumin (HSA) is a multifunctional protein with ligand binding, transporting and buffering properties. Posttranslational modifications and ligand binding processes are closely related to albumin final functional status. In the last few decades, HSA has been characterized using a broad spectrum of methods, but quantitative data on the HSA's modifications among individuals have not been reported. The investigations presented here are based on the non-denaturing electrocatalytic screening of HSA samples isolated from the blood serum of healthy subjects. The electrocatalytic responses of the native protein (Rnat) varied depending on its modifications among individuals, which enable us to express the inter-individual variability. Consequently, the native HSA samples were subjected to ex vivo carbonylation with 50 mM methylglyoxal for 36 h. The differences between Rnat and the responses of artificially carbonylated protein (Rmod) corresponded with inter-individual binding capacity variations (ΔR = Rnat-Rmod). The coefficients of variation for the Rnat and ΔR values of purified HSA samples were estimated to be 8.5 and 23.2%, respectively. A sensitive non-denaturing electrocatalytic assay was utilized to provide new data about albumin inter-individual variations and evaluate its oxidative modifications and binding capacity, which could be used for further studies targeting not only on HSA but also other clinically important proteins.
Current possibilities and limitations of the simulation of in vivo magnetic resonance spectroscopic signals are demonstrated from the point of view of a simulation software user as well as its programmer. A brief review of the quantum-mechanical background addresses the specific needs of simulation implementation and in vivo MR spectroscopy in general. Practical application examples demonstrate how flexible simulation software, such as NMRScopeB, can be utilized not only for the preparation of metabolite basis signals for quantification of metabolite concentrations, but also in pulse sequence development, assessment of artifacts and analyzing mechanism leading to unexpected signal phenomena.
The main mechanism of action of platinum-based cytostatic drugs - cisplatin, oxaliplatin and carboplatin - is the formation of DNA cross-links, which restricts the transcription due to the disability of DNA to enter the active site of the polymerase. The polymerase chain reaction (PCR) was employed as a simplified model of the amplification process in the cell nucleus. PCR with fluorescently labelled dideoxynucleotides commonly employed for DNA sequencing was used to monitor the effect of platinum-based cytostatics on DNA in terms of decrease in labeling efficiency dependent on a presence of the DNA-drug cross-link. It was found that significantly different amounts of the drugs - cisplatin (0.21 μg/mL), oxaliplatin (5.23 μg/mL), and carboplatin (71.11 μg/mL) - were required to cause the same quenching effect (50%) on the fluorescent labelling of 50 μg/mL of DNA. Moreover, it was found that even though the amounts of the drugs was applied to the reaction mixture differing by several orders of magnitude, the amount of incorporated platinum, quantified by inductively coupled plasma mass spectrometry, was in all cases at the level of tenths of μg per 5 μg of DNA.
- MeSH
- adukty DNA chemie metabolismus MeSH
- cisplatina chemie MeSH
- cytostatické látky chemie MeSH
- DNA analýza chemie metabolismus MeSH
- hmotnostní spektrometrie MeSH
- karboplatina chemie MeSH
- organoplatinové sloučeniny chemie MeSH
- platina chemie MeSH
- polymerázová řetězová reakce MeSH
- sekvenční analýza DNA * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
A survey of useful methods for separation and identification of regioisomers and enantiomers of triacylglycerols. Gas chromatography, gas chromatography-mass spectrometry, (13)C NMR determination of regioisomers by enzymatic methods, and supercritical fluid chromatography are briefly surveyed, whereas a detailed description is given of the analysis of triacylglycerols by liquid chromatography, especially with silver ion (Ag(+); argentation), and nonaqueous reversed phase liquid chromatography. Special attention is paid to chiral chromatography. Details of mass spectrometry of triacylglycerols are also described, especially the identification of important triacylglycerol ions such as [M + H-RCOOH](+) in atmospheric pressure chemical ionization mass spectra.
Acid sphingomyelinase deficiency (ASMd, Niemann-Pick disease A/B) and Niemann-Pick type C disease (NPC) share core clinical symptoms. Initial diagnostic discrimination of these two rare lysosomal storage diseases is thus difficult. As sphingomyelin accumulates in ASMd as well as NPC, lysosphingomyelin (sphingosylphosphorylcholine) and its m/z 509 analog were suggested as biomarkers for both diseases. Herein we present results of simultaneous LC-ESI-MS/MS measurements of lysosphingomyelin and lysosphingomyelin 509 in plasma and dried blood spots (DBS) collected from ASMd and NPC patients and suggest that the plasma but not DBS levels of the two analytes allow differential biochemical screening of ASMd and NPC.
- MeSH
- biologické markery krev MeSH
- chromatografie kapalinová metody MeSH
- fosforylcholin analogy a deriváty krev MeSH
- hmotnostní spektrometrie s elektrosprejovou ionizací metody MeSH
- lidé MeSH
- Niemannova-Pickova nemoc typu A krev diagnóza MeSH
- Niemannova-Pickova nemoc typu B krev diagnóza MeSH
- Niemannova-Pickova nemoc typu C krev diagnóza MeSH
- sfingosin analogy a deriváty krev MeSH
- studie případů a kontrol MeSH
- tandemová hmotnostní spektrometrie metody MeSH
- test suché kapky krve metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
