31 research outputs found
Nagłe zatrzymanie krążenia u pacjentki z kardiomiopatią okołoporodową i zatorowością płucną
Peripartum cardiomyopathy is a type of dilatated cardiomyopathy, occuring with symptoms of heart failure (HF) during lastmonth of pregnancy or within 5 months after labour. Authors are presenting the case of patient admitted to hospital primarywith diagnosis of non-high risk pulmonary embolism 6 weeks after delivery, who developed episode of sudden cardiac deathfollowed by symptoms of cardiogenic shock. Peripartum cardiomyopathy was additionally diagnosed. After HF treatment withbromocriptine supply, gradual clinical improvement was achieved. The patient was discharged after 15 days of hospitalisationwith diagnosis of peripartum cardiomyopathy with non-high risk pulmonary embolism
High-performance liquid chromatography–tandem mass spectrometry in the identification and determination of phase I and phase II drug metabolites
Applications of tandem mass spectrometry (MS/MS) techniques coupled with high-performance liquid chromatography (HPLC) in the identification and determination of phase I and phase II drug metabolites are reviewed with an emphasis on recent papers published predominantly within the last 6 years (2002–2007) reporting the employment of atmospheric pressure ionization techniques as the most promising approach for a sensitive detection, positive identification and quantitation of metabolites in complex biological matrices. This review is devoted to in vitro and in vivo drug biotransformation in humans and animals. The first step preceding an HPLC-MS bioanalysis consists in the choice of suitable sample preparation procedures (biomatrix sampling, homogenization, internal standard addition, deproteination, centrifugation, extraction). The subsequent step is the right optimization of chromatographic conditions providing the required separation selectivity, analysis time and also good compatibility with the MS detection. This is usually not accessible without the employment of the parent drug and synthesized or isolated chemical standards of expected phase I and sometimes also phase II metabolites. The incorporation of additional detectors (photodiode-array UV, fluorescence, polarimetric and others) between the HPLC and MS instruments can result in valuable analytical information supplementing MS results. The relation among the structural changes caused by metabolic reactions and corresponding shifts in the retention behavior in reversed-phase systems is discussed as supporting information for identification of the metabolite. The first and basic step in the interpretation of mass spectra is always the molecular weight (MW) determination based on the presence of protonated molecules [M+H]+ and sometimes adducts with ammonium or alkali-metal ions, observed in the positive-ion full-scan mass spectra. The MW determination can be confirmed by the [M-H]- ion for metabolites providing a signal in negative-ion mass spectra. MS/MS is a worthy tool for further structural characterization because of the occurrence of characteristic fragment ions, either MSn analysis for studying the fragmentation patterns using trap-based analyzers or high mass accuracy measurements for elemental composition determination using time of flight based or Fourier transform mass analyzers. The correlation between typical functional groups found in phase I and phase II drug metabolites and corresponding neutral losses is generalized and illustrated for selected examples. The choice of a suitable ionization technique and polarity mode in relation to the metabolite structure is discussed as well
The novel anticancer drug oracin: different stereospecificity and cooperativity for carbonyl reduction by purified human liver 11β-hydroxysteroid dehydrogenase type 1
Olaparib Synergizes the Anticancer Activity of Daunorubicin via Interaction with AKR1C3
Olaparib is a potent poly (ADP-ribose) polymerase inhibitor currently used in targeted therapy for treating cancer cells with BRCA mutations. Here we investigate the possible interference of olaparib with daunorubicin (Daun) metabolism, mediated by carbonyl-reducing enzymes (CREs), which play a significant role in the resistance of cancer cells to anthracyclines. Incubation experiments with the most active recombinant CREs showed that olaparib is a potent inhibitor of the aldo–keto reductase 1C3 (AKR1C3) enzyme. Subsequent inhibitory assays in the AKR1C3-overexpressing cellular model transfected human colorectal carcinoma HCT116 cells, demonstrating that olaparib significantly inhibits AKR1C3 at the intracellular level. Consequently, molecular docking studies have supported these findings and identified the possible molecular background of the interaction. Drug combination experiments in HCT116, human liver carcinoma HepG2, and leukemic KG1α cell lines showed that this observed interaction can be exploited for the synergistic enhancement of Daun’s antiproliferative effect. Finally, we showed that olaparib had no significant effect on the mRNA expression of AKR1C3 in HepG2 and KG1α cells. In conclusion, our data demonstrate that olaparib interferes with anthracycline metabolism, and suggest that this phenomenon might be utilized for combating anthracycline resistance
Stereoselective Disposition of S- and R-Licarbazepine in Mice
The stereoselective disposition of S-licarbazepine (S-Lic) and R-licarbazepine
(R-Lic) was investigated in plasma, brain, liver, and kidney tissues after their
individual administration (350 mg/kg) to mice by oral gavage. Plasma, brain, liver, and
kidney concentrations of licarbazepine enantiomers and their metabolites were determined
over the time by a validated chiral HPLC-UV method. The mean concentration
data, attained at each time point, were analyzed using a non-compartmental model. S-Lic
and R-Lic were rapidly absorbed from gastrointestinal tract of mouse and immediately
distributed to tissues supplied with high blood flow rates. Both licarbazepine enantiomers
were metabolized to a small extent, each parent compound being mainly responsible
for the systemic and tissue drug exposure. The stereoselectivity in the metabolism
and distribution of S- and R-Lic was easily identified. An additional metabolite was
detected following R-Lic administration and S-Lic showed a particular predisposition for
hepatic and renal accumulation. Stereoselective processes were also identified at the
blood–brain barrier, with the brain exposure to S-Lic almost twice that of R-Lic. Another
finding, reported here for the first time, was the ability of the mouse to perform the chiral
inversion of S- and R-Lic, albeit to a small extent
Bruton’s Tyrosine Kinase Inhibitors Ibrutinib and Acalabrutinib Counteract Anthracycline Resistance in Cancer Cells Expressing AKR1C3
Over the last few years, aldo-keto reductase family 1 member C3 (AKR1C3) has been associated with the emergence of multidrug resistance (MDR), thereby hindering chemotherapy against cancer. In particular, impaired efficacy of the gold standards of induction therapy in acute myeloid leukaemia (AML) has been correlated with AKR1C3 expression, as this enzyme metabolises several drugs including anthracyclines. Therefore, the development of selective AKR1C3 inhibitors may help to overcome chemoresistance in clinical practice. In this regard, we demonstrated that Bruton’s tyrosine kinase (BTK) inhibitors ibrutinib and acalabrutinib efficiently prevented daunorubicin (Dau) inactivation mediated by AKR1C3 in both its recombinant form as well as during its overexpression in cancer cells. This revealed a synergistic effect of BTK inhibitors on Dau cytotoxicity in cancer cells expressing AKR1C3 both exogenously and endogenously, thus reverting anthracycline resistance in vitro. These findings suggest that BTK inhibitors have a novel off-target action, which can be exploited against leukaemia through combination regimens with standard chemotherapeutics like anthracyclines
Coordination Compounds Based on 1,2,3,4-Tetrahydro-isoquinoline-3-carboxylic Acid
Syntheses of 2,6-bis[((3S)-3-(methoxycarbonyl)-1,2,3,4-tetrahydroisoquinolin-2-yl)carbonyl]pyridine and its coordination compounds with Cu2+, Co2+, Co3+, or Fe3+ are described. By means of 1H- and 13C-NMR spectra it was proved that 2,6-bis[((3S)-3-(methoxycarbonyl)-1,2,3,4-tetrahydroisoquinolin-2-yl)carbonyl]pyridine as well as its coordination compound with Co3+ exist in the form of a mixture of three conformers, differing in the conformations at the two amide groups present. The prepared coordination compounds were tested in the enantioselective catalysis of the nitroaldol addition of nitromethane with 2-nitrobenzaldehyde or 4-nitrobenzaldehyde, and in the Michael addition of ethyl 2-oxocyclohexanecarboxylate to but-3-en-2-one