Fipronil is an insecticide that is not approved in the European Union in food. In 2017, fipronil was involved in a European health alert due to its presence in fresh hen eggs because of an illicit use in poultry farms, so reliable methods are needed to determine fipronil and its main metabolites in these matrixes. In this work, we report the first approach to the study of fipronil and two metabolites, fipronil-sulfone and fipronil-sulfide by CE. MEKC mode was employed using a solution of 50 mM ammonium perfluorooctanoate pH 9.0 with 10% (v/v) methanol as background electrolyte. The proposed method was combined with a simple sample treatment based on salting-out assisted LLE (SALLE) using acetonitrile as extraction solvent and ammonium sulfate as salt. The SALLE-MEKC-UV method allowed the simultaneous quantification of fipronil and fipronil-sulfone. Validation parameters yielded satisfactory results, with precision, expressed as relative SD, below 14% and recoveries higher than 83%. Limits of detection were 90 µg/kg for fipronil and 150 µg/kg for fipronil-sulfone, so in terms of sensitivity further studies of sample treatments allowing extra preconcentration or the use of more sensitive detection, such as MS, would be needed.

• MeSH
• acetonitrily MeSH
• chromatografie micelární elektrokinetická kapilární metody   MeSH
• insekticidy MeSH
• kur domácí MeSH
• limita detekce MeSH
• lineární modely MeSH
• pyrazoly analýza   MeSH
• reprodukovatelnost výsledků MeSH
• vejce analýza   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Riociguat is novel antihypertensive drug for treatment of pulmonary hypertension. As such, it is still being tested in many clinical and pharmacokinetic trials. Existing methods that determine serum riociguat and desmethylriociguat (DMR) are based solely on liquid chromatography with mass spectrometry. Therefore, we present a novel capillary electrophoresis with mass spectrometry method (CE-MS) for their determination in human serum as alternative method for ongoing trials. Complete resolution of both analytes was achieved by means of pH optimization of ammonium formate background electrolytes that are fully compatible with ESI/MS detection. Simple liquid-liquid extraction was used as sample pretreatment. The calibration dependence of the method was linear (in the range of 10-1000 ng/mL), with adequate accuracy (90.1-114.9%) and precision (13.4%). LOD and LOQ were arbitrarily set at 10 ng/mL for both analytes. Clinical applicability was validated using serum samples from patients treated with riociguat in pharmacokinetic study and the results corresponded with reference HPLC-MS/MS values. Capillary electrophoresis proved to be sensitive and selective tool for the analysis of riociguat and DMR.

• MeSH
• elektroforéza kapilární metody   MeSH
• elektrolyty MeSH
• extrakce kapalina-kapalina MeSH
• hmotnostní spektrometrie s elektrosprejovou ionizací metody   MeSH
• lidé MeSH
• limita detekce MeSH
• lineární modely MeSH
• pyrazoly krev   chemie   izolace a purifikace   farmakokinetika   MeSH
• pyrimidiny krev   chemie   izolace a purifikace   farmakokinetika   MeSH
• reprodukovatelnost výsledků MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Riociguat is a novel antihypertensive drug for the treatment of pulmonary hypertension. We present electrophoretic characterization, i.e. migration behavior of riociguat and metabolite M1 as support for optimized CZE/MS assay. Fundamental separation parameters, such as peak width, symmetry, and resolution are studied in a series of ammonium formate buffers within pH range 2.60-5.61. The narrow region of peak symmetry lies close to pH 4.0 for both analytes. Accordingly, the value of resolution maximizes in a background electrolyte adjusted to pH 4.10. Basic calibration parameters estimated from CZE experiments with absorption photometric and mass spectrometric detection of riociguat and metabolite M1 were evaluated. More than three orders lower LOD was achieved with high resolution mass spectrometric detection. The observed difference in the sensitivity of both detection techniques gives priority to the utilization of CZE/MS in practice. The values of dissociation constants of riociguat and metabolite M1, pKBH , were determined from CZE measurements in lithium formate and lithium acetate background electrolytes with constant ionic strength. The value of pKBH = 4.30 ± 0.02 for riociguat corresponds well to the value already presented in the literature. According to our observation, metabolite M1 behaves like a slightly stronger base with estimated pKBH = 4.40 ± 0.02.

• MeSH
• elektroforéza kapilární metody   MeSH
• hmotnostní spektrometrie metody   MeSH
• lidé MeSH
• limita detekce MeSH
• lineární modely MeSH
• pyrazoly analýza   krev   chemie   metabolismus   MeSH
• pyrimidiny analýza   krev   chemie   metabolismus   MeSH
• reprodukovatelnost výsledků MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• aminopyrin MeSH
• chlorid uhličitý aplikace a dávkování   toxicita   MeSH
• dechové testy MeSH
• játra enzymologie   patofyziologie   účinky léků   MeSH
• krysa rodu rattus MeSH
• transaminasy krev   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH

A simple, rapid, and environmentally friendly HPLC method was developed and validated for the separation of four compounds (4-aminophenol, caffeine, paracetamol, and propyphenazone) with different chemical properties. A "green" mobile phase, employing water as the major eluent, was proposed and applied to the separation of analytes with different polarity on polyethylene glycol (PEG) stationary phase. The chromatography separation of all compounds and internal standard benzoic acid was performed using isocratic elution with a low-toxicity mobile phase consisting of 0.04% (v/v) triethylamine and water. HPLC separation was carried out using a PEG reversed-phase stationary phase Supelco Discovery HS PEG column (15 × 4 mm; particle size 3 μm) at a temperature of 30 °C and flow rate at 1.0 mL min(-1). The UV detector was set at 210 nm. In this study, a PEG stationary phase was shown to be suitable for the efficient isocratic separation of compounds that differ widely in hydrophobicity and acid-base properties, particularly 4-aminophenol (log P, 0.30), caffeine (log P, -0.25), and propyphenazone (log P, 2.27). A polar PEG stationary phase provided specific selectivity which allowed traditional chromatographic problems related to the separation of analytes with different polarities to be solved. The retention properties of the group of structurally similar substances (aromatic amines, phenolic compounds, and xanthine derivatives) were tested with different mobile phases. The proposed green chromatography method was successfully applied to the analysis of active substances and one degradation impurity (4-aminophenol) in commercial preparation. Under the optimum chromatographic conditions, standard calibration was carried out with good linearity correlation coefficients for all compounds in the range (0.99914-0.99997, n = 6) between the peak areas and concentration of compounds. Recovery of the sample preparation was in the range 100 ± 5% for all compounds. The intraday method precision was determined as RSD, and the values were lower than 1.00%.

• MeSH
• acetonitrily chemie   MeSH
• aminofenoly analýza   izolace a purifikace   MeSH
• ethylaminy chemie   MeSH
• fenazon analogy a deriváty   analýza   izolace a purifikace   MeSH
• hydrofobní a hydrofilní interakce MeSH
• kalibrace MeSH
• kofein analýza   izolace a purifikace   MeSH
• methanol chemie   MeSH
• paracetamol analýza   izolace a purifikace   MeSH
• polyethylenglykoly chemie   MeSH
• reprodukovatelnost výsledků MeSH
• tablety analýza   MeSH
• ultrafialové záření MeSH
• vysokoúčinná kapalinová chromatografie přístrojové vybavení   metody   normy   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The major aim of this work is to demonstrate the applicability of micellar electrokinetic capillary chromatography with SDS based pseudostationary phase for the screening of cytochrome P450 inhibitors. In contrast with the other capillary electrophoresis modes the cytochrome P450 reaction mixture thus could be used for the analysis without any pre-treatment. Cytochrome P450 2C9, one of the most important isoforms in human liver, was chosen as a model example for this study in combination with diclofenac as a probe substrate. The inhibitory effect on the given cytochrome P450 reaction was evaluated for two inhibitors with different inhibition potential - strong inhibitor sulfaphenazole and moderate inhibitor ketoconazole. As a result 50% inhibitory concentrations IC(50) and inhibition constants K(i) were evaluated; their values for both inhibitors were in a good agreement with the literature data determined by different methods.

• MeSH
• aromatické hydroxylasy antagonisté a inhibitory   chemie   MeSH
• chromatografie micelární elektrokinetická kapilární metody   MeSH
• diklofenak farmakologie   chemie   MeSH
• financování organizované MeSH
• inhibitory cytochromu P450 MeSH
• ketokonazol farmakologie   chemie   MeSH
• lidé MeSH
• molekulární struktura MeSH
• reprodukovatelnost výsledků MeSH
• sulfafenazol farmakologie   chemie   MeSH
• systém (enzymů) cytochromů P-450 chemie   MeSH
• Check Tag
• lidé MeSH

The purpose of this study was to assess the prognostic value of ultra-low dose thallium myocardial perfusion imaging. Three hundred and sixty-six patients (245 men) underwent ultra-low dose stress-redistribution imaging on CZT SPECT camera GE Discovery NM 530c. The stress test was performed by bicycle ergometry or regadenoson injection. The activity of 0.5 MBq (0.014 mCi) Tl-201 chloride per kilogram of body weight was administered. The stress images were acquired immediately and redistribution images were taken after 3 h. Patient follow-up was focused on combined end-point (death, myocardial infarction, unstable angina, revascularization and hospitalization for heart failure). Data analysis was performed from hospital database, with a mean period 23 months. Patients with revascularization within 1 month after SPECT was excluded as revascularization for diagnosis. Ischaemia on SPECT was found in 72 patients, 294 patients were without ischaemia. In patients with ischaemia there were 21 (29.2%) subjects with cardiac events, and 23 (7.9%) in patients without ischaemia (HR 4.15, 95% CI 2.30-7.51, p < 0.0001). Ultra-low dose thallium perfusion imaging using CZT camera provides very good prognostic results in assessment of myocardial ischaemia.

• MeSH
• časové faktory MeSH
• dávka záření * MeSH
• design vybavení MeSH
• gama kamery * MeSH
• ischemická choroba srdeční diagnostické zobrazování   mortalita   patofyziologie   terapie   MeSH
• jednofotonová emisní výpočetní tomografie škodlivé účinky   přístrojové vybavení   metody   MeSH
• kadmium * MeSH
• koronární cirkulace * MeSH
• lidé středního věku MeSH
• lidé MeSH
• pilotní projekty MeSH
• prediktivní hodnota testů MeSH
• prognóza MeSH
• progrese nemoci MeSH
• puriny aplikace a dávkování   MeSH
• pyrazoly aplikace a dávkování   MeSH
• radiační expozice škodlivé účinky   prevence a kontrola   MeSH
• radiofarmaka aplikace a dávkování   škodlivé účinky   MeSH
• radioizotopy thallia aplikace a dávkování   škodlivé účinky   MeSH
• reprodukovatelnost výsledků MeSH
• senioři MeSH
• telur * MeSH
• vazodilatancia aplikace a dávkování   MeSH
• zátěžový test MeSH
• zinek * MeSH
• zobrazování myokardiální perfuze škodlivé účinky   přístrojové vybavení   metody   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Activin receptor-like kinases 1-7 (ALK1-7) regulate a complex network of SMAD-independent as well as SMAD-dependent signaling pathways. One of the widely used inhibitors for functional investigations of these processes, in particular for bone morphogenetic protein (BMP) signaling, is LDN-193189. However, LDN-193189 has insufficient kinome-wide selectivity complicating its use in cellular target validation assays. Herein, we report the identification and comprehensive characterization of two chemically distinct highly selective inhibitors of ALK1 and ALK2, M4K2234 and MU1700, along with their negative controls. We show that both MU1700 and M4K2234 efficiently block the BMP pathway via selective in cellulo inhibition of ALK1/2 kinases and exhibit favorable in vivo profiles in mice. MU1700 is highly brain penetrant and shows remarkably high accumulation in the brain. These high-quality orthogonal chemical probes offer the selectivity required to become widely used tools for in vitro and in vivo investigation of BMP signaling.

• MeSH
• aktivinové receptory typu I antagonisté a inhibitory   metabolismus   MeSH
• aktivinové receptory typu II * metabolismus   antagonisté a inhibitory   MeSH
• inhibitory proteinkinas farmakologie   chemie   MeSH
• kostní morfogenetické proteiny metabolismus   MeSH
• lidé MeSH
• molekulární sondy chemie   MeSH
• myši MeSH
• objevování léků MeSH
• pyrazoly chemie   farmakologie   chemická syntéza   MeSH
• signální transdukce účinky léků   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

In this work, an application of an enzymatic reaction for the determination of the highly hydrophobic drug propofol in emulsion dosage form is presented. Emulsions represent a complex and therefore challenging matrix for analysis. Ethanol was used for breakage of a lipid emulsion, which enabled optical detection. A fully automated method based on Sequential Injection Analysis was developed, allowing propofol determination without the requirement of tedious sample pre-treatment. The method was based on spectrophotometric detection after the enzymatic oxidation catalysed by horseradish peroxidase and subsequent coupling with 4-aminoantipyrine leading to a coloured product with an absorbance maximum at 485 nm. This procedure was compared with a simple fluorimetric method, which was based on the direct selective fluorescence emission of propofol in ethanol at 347 nm. Both methods provide comparable validation parameters with linear working ranges of 0.005-0.100 mg mL(-1) and 0.004-0.243 mg mL(-1) for the spectrophotometric and fluorimetric methods, respectively. The detection and quantitation limits achieved with the spectrophotometric method were 0.0016 and 0.0053 mg mL(-1), respectively. The fluorimetric method provided the detection limit of 0.0013 mg mL(-1) and limit of quantitation of 0.0043 mg mL(-1). The RSD did not exceed 5% and 2% (n=10), correspondingly. A sample throughput of approx. 14 h(-1) for the spectrophotometric and 68 h(-1) for the fluorimetric detection was achieved. Both methods proved to be suitable for the determination of propofol in pharmaceutical formulation with average recovery values of 98.1 and 98.5%.

• MeSH
• ampyron metabolismus   MeSH
• automatizace MeSH
• fluorescence MeSH
• fluorometrie metody   MeSH
• indikátory a reagencie metabolismus   MeSH
• křenová peroxidasa metabolismus   MeSH
• propofol analýza   MeSH
• průtoková injekční analýza metody   MeSH
• spektrofotometrie ultrafialová metody   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Přímá antikoagulancia se v posledních letech těší stále větší oblibě. Jejich výhody spočívají mimo jiné v jednoduchosti aplikace, vysoké bezpečnosti a absenci potřeby pravidelné monitorace účinku. Mezi již známé a ověřené indikace patří prevence tromboembolických příhod u pacientů s nevalvulární fibrilací síní a po ortopedických zákrocích, léčba a prevence hluboké žilní trombózy a plicní embolie. V prezentovaném článku se zmiňujeme o relativně nových poznatcích využití přímých antikoagulancií u pacientů před kardioverzí, ablačními výkony či po perkutánní koronární intervenci.

Direct anticoagulants have become increasingly popular in recent years. Their benefits include, among other things, ease ofapplication, high safety and the absence of the need for regular monitoring. The well-known and validated indications are theprevention of thromboembolic events in patients with non-valvular atrial fibrillation, post-orthopedic surgery, treatment andprevention of venous thrombosis and pulmonary embolism. In actual article we mention relatively new knowledges about theuse of direct anticoagulations in patients before cardioversion, catheter ablation or after percutaneous coronary intervention.

• MeSH
• antikoagulancia * aplikace a dávkování   klasifikace   terapeutické užití   MeSH
• aplikace orální * MeSH
• dabigatran aplikace a dávkování   škodlivé účinky   terapeutické užití   MeSH
• elektrická defibrilace metody   využití   MeSH
• fibrilace síní farmakoterapie   prevence a kontrola   terapie   MeSH
• inhibitory faktoru Xa * klasifikace   terapeutické užití   MeSH
• katetrizační ablace metody   využití   MeSH
• koronární angioplastika metody   využití   MeSH
• lidé MeSH
• metaanalýza jako téma MeSH
• pyrazoly aplikace a dávkování   škodlivé účinky   terapeutické užití   MeSH
• pyridiny aplikace a dávkování   škodlivé účinky   terapeutické užití   MeSH
• statistika jako téma MeSH
• thiazoly aplikace a dávkování   škodlivé účinky   terapeutické užití   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH