Search results for "Amides"
showing 10 items of 552 documents
Simultaneous determination of different classes of antibiotics in fish and livestock by CE-MS
2007
A specific CE-MS method was developed for the simultaneous determination of 12 antibacterial residues (four sulfonamides: sulfamethazine, sulfathiazole, sulfadiazine, and sulfachlorpyridazine; four beta-lactams: amoxicillin, ampicillin, oxacillin, and penicillin V, and four quinolones: danofloxacin, enrofloxacin, ofloxacin, and flumequine) in fish and livestock. Separation conditions, sheath liquid composition and electrospray parameters were optimized to obtain adequate CE separation and a high sensitivity. CE employed a 75 cm long fused-silica capillary (50 cm thermostated plus 25 cm at room temperature) 75 microm id and a 60 mM ammonium acetate separation buffer at pH 8 with 10% of metha…
Adverse events associated with encorafenib plus binimetinib in the COLUMBUS study: incidence, course and management.
2019
Abstract Background Dual inhibition of the mitogen-activated protein kinase pathway with BRAF/MEK inhibitor (BRAFi/MEKi) therapy is a standard treatment for BRAFV600-mutant metastatic melanoma and has historically been associated with grade III pyrexia or photosensitivity depending on the combination used. The objective of this study was to fully describe adverse events from the COLUMBUS study evaluating the most recent BRAF/MEK inhibitor combination encorafenib+binimetinib. Patients and methods Patients with locally advanced, unresectable or metastatic BRAFV600-mutant melanoma were randomised to receive encorafenib 450 mg once daily plus binimetinib 45 mg twice daily, encorafenib 300 mg on…
Diverse compounds mimic Alzheimer disease–causing mutations by augmenting Aβ42 production
2004
Increased Abeta42 production has been linked to the development of Alzheimer disease. We now identify a number of compounds that raise Abeta42. Among the more potent Abeta42-raising agents identified are fenofibrate, an antilipidemic agent, and celecoxib, a COX-2-selective NSAID. Many COX-2-selective NSAIDs tested raised Abeta42, including multiple COX-2-selective derivatives of two Abeta42-lowering NSAIDs. Compounds devoid of COX activity and the endogenous isoprenoids FPP and GGPP also raised Abeta42. These compounds seem to target the gamma-secretase complex, increasing gamma-secretase-catalyzed production of Abeta42 in vitro. Short-term in vivo studies show that two Abeta42-raising comp…
Distribution of chlorpromazine in a simplified blood influenced by various drugs
1973
The binding of chlorpromazine to erythrocytes and to albumin as influenced by other drugs was studied in a simplified blood (31.5±0.3% bovine erythrocytes, 4 g-% bovine serum albumin in 0.02 M phosphate buffer solution containing 0.15 M NaCl). the total concentration of chlorpromazine in the simplified blood was 10−4 M, the concentration of the displacing drugs was 10−3 M. After an incubation period of 3 h at 22° C the chlorpromazine concentration was determined in the albumin solution after centrifugation of the blood at 3000×g and in the aqueous phase after ultracentrifugation at 150000×g. Under control conditions 68.1±0.9% of chlorpromazine was bound to the erythrocytes, 28.5±0.9% was bo…
Cross-talk between phosphatidic acid and ceramide during ethanol-induced apoptosis in astrocytes
2005
Background Ethanol inhibits proliferation in astrocytes, an effect that was recently linked to the suppression of phosphatidic acid (PA) formation by phospholipase D (PLD). The present study investigates ethanol's effect on the induction of apoptosis in astrocytes and the formation of ceramide, an apoptotic signal. Evidence is presented that the formation of PA and ceramide may be reciprocally linked during ethanol exposure. Results In cultured rat cortical astrocytes, ethanol (0.3–1 %, v/v) induced nuclear fragmentation and DNA laddering indicative of apoptosis. Concomitantly, in cells prelabeled with [3H]-serine, ethanol caused a dose-dependent, biphasic increase of the [3H]-ceramide/ [3H…
Evaluation of P-glycoprotein (abcb1a/b) modulation of [18F]fallypride in MicroPET imaging studies
2012
[(18)F]Fallypride ([(18)F]FP) is an important and routinely used D2/D3 antagonist for quantitative imaging of dopaminergic neurotransmission in vivo. Recently it was shown that the brain uptake of the structurally related [(11)C]raclopride is modulated by P-glycoprotein (P-gp), an important efflux transporter at the blood-brain barrier. The purpose of this study was to determine whether the brain uptake of [(18)F]FP is influenced by P-gp. For examination of this possible modulation microPET studies were performed in a rat and a mouse model. Hence, [(18)F]FP was applied to Sprague Dawley rats, half of them being treated with the P-gp inhibitor cyclosporine A (CsA). In a second experimental s…
Estimation of formamide harmonic and anharmonic modes in the Kohn-Sham limit using the polarization consistent basis sets.
2010
Formamide harmonic and anharmonic frequencies of fundamental vibrations in the gas phase and in several solvents were successfully estimated in the B3LYP Kohn-Sham complete basis set limit (KS CBS). CBS results were obtained by extrapolating a power function (two-parameter formula) to the results calculated with polarization-consistent basis sets. Anharmonic corrections using the second order perturbation treatment (PT2) and hybrid B3LYP functional combined with polarization consistent pc-n (n = 0, 1, 2, 3, 4) and several Pople’s basis sets were analyzed for all fundamental formamide vibrational modes in the gas phase and solution. Solvent effects were modeled within a PCM method. The anhar…
The mechanism of formamide hydrolysis in water from ab initio calculations and simulations.
2005
The neutral hydrolysis of formamide in water is a suitable reference to quantify the efficiency of proteolytic enzymes. However, experimental data for this reaction has only very recently been obtained and the kinetic constant determined experimentally is significantly higher than that predicted by previous theoretical estimations. In this work, we have investigated in detail the possible mechanisms of this reaction. Several solvent models have been considered that represent a considerable improvement on those used in previous studies. Density functional and ab initio calculations have been carried out on a system which explicitly includes the first solvation shell of the formamide molecule…
Chromatographically separable rotamers of an unhindered amide
2014
Surprisingly stable formamide rotamers were encountered in the tetrahydroisoquinoline and morphinan series of alkaloids. We investigated the hindered rotation around the amide bond by dynamic high-performance liquid chromatography (DHPLC) and kinetic measurements of the interconversion of the rotamers which can readily be separated by HPLC as well as TLC. The experimental results of the different methods were compared to each other as well as to results obtained by DFT calculations.
Squaramide-based reagent for selective chromogenic sensing of Cu(II) through a zwitterion radical.
2010
A minimalist squaramide-based chemodosimeter for Cu(2+) is described. Upon selective chelation to 2, Cu(2+) induces the formation of a highly colored zwitterionic radical, which is kinetically stable for hours. The presence of a radical is confirmed by EPR and ESI-MS. It is then possible to use reagent 2 for visual and selective sensing of Cu(2+) at neutral pH.