Association between hemorrhage and direct oral anticoagulants in combination with verapamil: Analysis of Japanese Adverse Drug Event Report database and electronic medical record data.

OBJECTIVE: The aim of this study was to investigate the risk of hemorrhage in concomitant therapy with direct oral anticoagulants (DOACs) and class IV antiarrhythmic drugs. MATERIALS AND METHODS: First, disproportionality analysis (DPA) was performed using the Japanese Adverse Drug Event Report (JADER) database to investigate the risk of hemorrhage with DOACs. Second, a cohort study was performed using electronic medical record data to confirm the results of the JADER analysis. RESULTS: In the JADER analysis, hemorrhage was significantly associated with treatment with edoxaban and verapamil (reporting odds ratio = 1.66; 95% confidence interval (CI) = 1.04 - 2.67). The cohort study revealed that hemorrhage incidence significantly differed between the verapamil-treated group and the bepridil-treated group, with a higher risk for hemorrhage in the verapamil group (log-rank test: p < 0.001). The multivariate Cox proportional hazards model also showed that the verapamil and DOAC combination was significantly associated with hemorrhage events compared with the bepridil and DOAC combination (hazard ratio (HR): 2.87, 95% CI: 1.17 - 7.07, p = 0.022). Furthermore, creatinine clearance (Ccr) ≥ 50 mL/min was significantly associated with hemorrhage events (HR: 2.72, 95% CI: 1.03 - 7.18, p = 0.043), and verapamil was significantly associated with hemorrhage in patients with Ccr ≥ 50 mL/min (HR: 3.58, 95% CI: 1.36 - 9.39, p = 0.010) but not in patients with Ccr < 50 mL/min. CONCLUSION: Verapamil increases the risk of hemorrhage in patients on DOACs. Dose adjustment of DOACs based on renal function may prevent hemorrhage when verapamil is concomitantly administered.

A novel condition for capillary electrophoretic analysis of reductively aminated saccharides without removal of excess reagents.

We have identified novel CE conditions for the separation of 7-amino-4-methylcoumarin-labeled monosaccharides and oligosaccharides from glycoproteins. Using a neutrally coated capillary and alkaline borate buffer containing hydroxypropylcellulose and ACN, saccharide derivatives form anionic borate complexes, which move from the cathode to the anode in an electric field and are detected near the anodic end. Excess labeling reagents and other fluorescent products remain at the cathodic end. Fluorimetric detection using an LED as a light source enables determination of monosaccharide derivatives with good linearity between at least 0.4 and 400 µM, may correspond to 140 amol to 140 fmol. The lower LOD (S/N = 5) is only 80 nM in the sample solution (ca. 28 amol). The results were comparable to reported values using fluorometric detection LC. The method was also applied to the analysis of oligosaccharides that were enzymatically released from glycoproteins. Fine resolution enables profiling of glycans in glycoproteins. The applicability of the method was examined by applying it to other derivatives labeled with nonacidic tags such as ethyl p-aminobenzoate- and 2-aminoacridone-labeled saccharides.

[TDM management system for contribution to proper use of anti-mRSA drugs--establishment of cooperation support system between pharmacy and clinical laboratory in hospital].

In team medicine, highly specialized pharmacists have recently been in demand. As one of the specialties, there is therapeutic drug monitoring (TDM). It is important for the optimal dosing of a wide range of drugs. In our hospital, a TDM service was started in 1987 at the clinical laboratory. A clinical laboratory technologist with the license of a pharmacist has performed administration plans for anti-methicillin-resistant Staphylococcus aureus (MRSA) drugs, vancomycin, teicoplanin, and arbekacin. In particular, the pharmacist in charge of TDM services, a TDM-specialized pharmacist, plays a central role in administration plans for anti MRSA drugs. Furthermore, we examined the active use of the TDM service to expand pharmaceutical care. Therefore, at first, we have worked in partnership with the clinical laboratory, as it is called the "Cooperation Support System", since September 2010. As a result, after the introduction of this system, from August 2011 to July 2012, the rate that the doctor referred to the administration plan was markedly improved by approximately 90%. We have been able to enhance TDM in practical training for pharmacology as an extension of this system. We thought that drug therapy can be performed more appropriately by increasing the number of executions of TDM in the future. For drug therapy to be done more appropriately, efforts made through cooperation with the clinical laboratory are essential for an effective TDM system. Naturally, an effective TDM process requires a collaborative, multidisciplinary approach with input from doctors, nurses, and clinical pharmacists.

Optimized conditions for high-performance liquid chromatography analysis of oligosaccharides using 7-amino-4-methylcoumarin as a reductive amination reagent.

Reductive amination reaction using 7-amino-4-methylcoumarin (AMC) as a fluorescent probe enabled analyses of glycoproteins' monosaccharides and N-linked oligosaccharides. Reductive amination of N-acetylhexosamines and AMC using sodium cyanoborohydride or dimethylamine-borane complex indicated slight recovery of derivatives, but pyridine-borane achieved better recoveries. Reversed-phase high-performance liquid chromatography (HPLC) analyses of monosaccharides constituting glycoprotein glycans using fluorimetric detection revealed linearity for 0.2 fmol to 1 pmol, with less than 5% RSD quantitation reproducibility. Reversed-phase HPLC analyses of glycoprotein glycans, combined with negative-ion electrospray ionization mass spectrometry (LC-ESI-MS), enabled their structural determination. Using this highly hydrophobic reagent, AMC-labeled oligosaccharides displayed one-order to two-order higher ESI-MS intensity than derivatives labeled using other reagents.

Affinity entrapment of oligosaccharides and glycopeptides using free lectin solution.

Two procedures were proposed for the specific recovery of fluorescent derivatives of glycoprotein-derived oligosaccharides and tryptic glycopeptides using certain plant lectins. The first was based on the salting out of oligosaccharide-lectin conjugates with ammonium sulfate. Oligosaccharides specifically bound to lectins were recovered free from lectins using ethanol precipitation after dissolution in water. This method enabled group separation of 2-aminopyridine-labeled oligosaccharides derived from ovalbumin to galacto-oligosaccharides and agalacto-oligosaccharides by Ricinus communis agglutinin, and to high mannose- and hybrid-type oligosaccharides by wheat-germ agglutinin. Fractional precipitation based on differences in affinity for concanavalin A was accomplished by adding an appropriate concentration of methyl α-mannoside as an inhibitor. In the second method, tryptic digests of glycoproteins were mixed with a lectin solution, and the glycopeptide-lectin conjugates were specifically trapped on a centrifugal ultrafiltration membrane with cut-off of 10 kD. Trapped glycopeptides, as retentates, were passed through membranes by resuspension in diluted acid. This method is particularly useful for the enrichment of glycopeptides in protease digestion mixtures for glycosylation analyses by liquid chromatography-mass spectrometry.

Specific extraction of sialic-acid-containing glycans and glycopeptides using serotonin-bonded silica.

Serotonin-bonded silica was developed for specific extraction of sialic-acid-containing glycans and glycopeptides. Serotonin, coupled by reductive amination with aldehyde silica particles via its ethylamino group, has strong affinity to sialic acid in glycan chain termini. Sialylated glycans trapped on serotonin silica particles are released by washing with ammonium acetate solution, providing highly efficient specific trap and release glycoconjugates. With >100 micromol/g adsorption capacity, the particles are applicable to purify labeled glycans after derivatization with 2-aminopyridine to remove excess reagents. Serotonin silica efficiently enriches sialic-acid-containing glycopeptides from tryptic digests for LC/MS analysis of glycans' heterogeneity in glycoproteins.

Structures and interaction with DNA of ternary palladium(II) complexes: [Pd(Gly)(X)] (Gly=glycine; X=2,2'-bipyridine, 1,10-phenanthroline and 2,2'-bi-pyridylamine).

The structures of the ternary palladium(II) complexes of the formulations [Pd(Gly)(bpy)](+)Cl(-).4H(2)O (Gly=glycine; bpy=2,2'-bipyridine) (1), [Pd(Gly)(phen)](+)Cl(-).4H(2)O (2) (phen=1,10-phenanthroline) and {[Pd(Gly)(bpa)](+)Cl(-)}(2).6H(2)O (3) (bpa=2,2'-bipyridylamine) were determined. All complexes are positively charged and neutralized by the chloride anion located nearby the complexes. The central Pd(II) atoms of the complexes 1, 2 and 3 have a similar distorted square planar coordination geometry, in which each Pd(II) atom is coordinated to two N atoms of the bidentate heterocyclic ligand, and N and O atoms of the bidentate glycine ligand. The interaction of the complexes with calf thymus (CT) DNA was also studied using the fluorescence method. All complexes showed the inhibition of ethidium bromide binding to CT DNA, and the DNA-binding strengths were reflected as the relative order 2>1>3. The remarkable reduction of UV absorption intensity of 2 caused in the presence of DNA suggests the presence of pi-pi stacking interaction between the heterocyclic ring of the phen ligand and nucleobases. The intercalative DNA-binding of 2 is suggested by UV and CD measurements. DNA cleavage studies indicated that the cleavage of the plasmid supercoiled pBR322 DNA in the presence of H(2)O(2) and ascorbic acid could be enhanced by the complexes.

Structures and DNA-binding and cleavage properties of ternary copper(II) complexes of glycine with phenanthroline, bipyridine, and bipyridylamine.

The crystal structures of the series of three complexes, [Cu(Gly)(bpy)Cl].2H2O (1) (Gly=glycine; bpy=2,2'-bipyridine), [Cu(Gly)(phen)Cl]2.7H2O (2) (phen=1,10-phenanthroline), and [Cu(Gly)(bpa)(H2O)Cl] (3) (bpa=2,2'-bipyridylamine) were determined, and the coordination modes of Cu(II) ternary complexes were compared. The central Cu(II) atoms of complexes 1 and 3 have a similar distorted octahedral coordination geometry, while the Cu(II) atom of complex 2 has a distorted square pyramidal coordination. In all complexes, the aromatic heterocyclic compounds bpy, phen, and bpa, behave as a bidentate N,N' ligand, and Gly behaves as a bidentate N,O ligand. DNA-binding properties of the complexes to calf thymus (CT) DNA were studied by using the fluorescence method. Each of the complexes showed binding propensity to CT DNA with the relative order 2>3> or =1. DNA cleavage studies indicate that each of the complexes, especially 2, can cleave plasmid supercoiled pBR322 DNA in the presence of H2O2 and ascorbic acid with cleavage efficiency in the order 2>3 approximately 1. The degradation of the conformation of CT DNA by the complexes was also reflected in the decrease in the intensities of the characteristic CD bands with the relative order 2>3 approximately 1.

Recovery of free oligosaccharides from derivatives labeled by reductive amination.

This study examined chemical regeneration of free oligosaccharides from their fluorescent derivatives prepared by reductive amination with various aromatic amines. Maltose derivatives of ethyl 4-aminobenzoate (p-ABEE), 2-aminobenzonitrile (o-ABN), 4-aminobenzonitrile (p-ABN), 7-amino-4-methylcoumarin (AMC), 2-aminobenzoic acid (o-ABA), 2-aminobenzamide (o-ABAD), 2-aminopyridine (AP), and 8-aminonaphthalene-1,3,6-trisulfonate (ANTS) were incubated at 30 degrees C with an aqueous solution of hydrogen peroxide/acetic acid. Recoveries of maltose from p-ABEE, p-ABN, and AMC derivatives were fairly good and gave approximately 90% of maltose. Recoveries of maltose from its o-substituted aniline (o-ABA, o-ABAD, and o-ABN) derivatives were 5-40%, but maltose was unrecoverable from AP and ANTS derivatives. Nevertheless, prior treatment of an AP derivative with cyanogen bromide enabled the regeneration of maltose in high yields. As an application, p-ABEE-labeled N-glycans from some glycoproteins separated on an amide column were identified by converting peak components to their AP derivatives via free saccharides and following mapping by reversed-phase chromatography.