UVPD Spectroscopy of Differential Mobility-Selected Prototropic Isomers of Rivaroxaban.

Two ion populations of protonated Rivaroxaban, [C19H18ClN3O5S + H]+, are separated under pure N2 conditions using differential mobility spectrometry prior to characterization in a hybrid triple quadrupole linear ion trap mass spectrometer. These populations are attributed to bare protonated Rivaroxaban and to a proton-bound Rivaroxaban-ammonia complex, which dissociates prior to mass-selecting the parent ion. Ultraviolet photodissociation (UVPD) and collision-induced dissociation (CID) studies indicate that both protonated Rivaroxaban ion populations are comprised of the computed global minimum prototropic isomer. Two ion populations are also observed when the collision environment is modified with 1.5% (v/v) acetonitrile. In this case, the protonated Rivaroxaban ion populations are produced by the dissociation of the ammonium complex and by the dissociation of a proton-bound Rivaroxaban-acetonitrile complex prior to mass selection. Again, both populations exhibit a similar CID behavior; however, UVPD spectra indicate that the two ion populations are associated with different prototropic isomers. The experimentally acquired spectra are compared with computed spectra and are assigned to two prototropic isomers that exhibit proton sharing between distal oxygen centers.

Stability of Extemporaneously Compounded Nadolol 10-mg/mL Suspension in Oral Mix in Glass and Plastic Bottles and Plastic Syringes.

An oral liquid formulation of nadolol, which is required for administration to patients who cannot swallow intact tablets, is not commercially available. The objective of this study was to evaluate the stability of nadolol 10 mg/mL prepared in Oral Mix vehicle and stored in amber glass, amber polyethylene terephthalate, or amber polyvinyl chloride for 91 days at 4ÆC and 25ÆC; and polypropylene oral plastic syringes at 25ÆC only. Three separate batches of nadolol suspension 10 mg/mL were prepared with Oral Mix. Of the suspension, 50-mL aliquots were stored in 100-mL bottles (amber glass, amber polyethylene terephthalate, or amber polyvinyl chloride). Half of the bottles from each container type were stored at 25ÆC and the other half at 4ÆC. On study days 0, 2, 7, 14, 21, 28, 42, 56, 72, and 91, nadolol concentration was determined using a reverse-phase, stability-indicating liquid chromatographic method from samples drawn from each type of container at each temperature. Oral syringes (3 mL), filled with 2 mL of suspension, were stored at 25ÆC and tested on days 0, 2, 7, 21, 42, and 91. The concentration of nadolol 10 mg/mL in Oral Mix in all study samples from bottles and oral syringes remained within 3.5% of the initial concentration. Based on the fastest degradation rate with 95% confidence, on day 91, between 99% to 100% and 98% to 100% remained in suspensions stored in bottles at 25ÆC and 4ÆC, respectively. Oral syringes at 25ÆC had 94% remaining on day 91. Multiple linear regression analysis demonstrated that the percent remaining was related to study day and container, but not temperature. On day 91, nadolol 10 mg/mL oral suspensions prepared with Oral Mix and stored in all bottle types at 4ÆC will retain more than 98% of the initial concentration compared to 99% at 25ÆC and only 94% when stored in oral syringes.

Protecting our patients by protecting ourselves: An analysis of the personal influenza immunization rate of Ontario community pharmacists.

BACKGROUND: With recent expansions to scope of practice that have allowed Canadian pharmacists to play a larger role in administering influenza vaccinations to the public, it is important that pharmacists themselves meet Canadian guidelines recommending that 80% of health care professionals and 100% of vaccinators receive an annual influenza vaccination. Unvaccinated health care professionals pose an infection risk to patients they serve and are at an increased risk of infection themselves. METHODS: An online, anonymous survey was sent to Ontario community pharmacists to determine whether they had received the influenza vaccination during the 2013-2014 influenza season. All significant univariate chi-square analysis respondent characteristics were included in a multivariate regression analysis model to determine predictors of vaccination status. RESULTS: A total of 780 pharmacists completed the survey (18.1% response rate), which showed that 7 in 10 Ontario community pharmacists received the influenza vaccine. Those certified to immunize were nearly 3 times more likely to have received the influenza vaccine than those not certified (81.6% versus 61.2%, respectively). DISCUSSION: Having 70% of Ontario community pharmacists vaccinated against influenza is both an accomplishment and an opportunity to improve vaccination rates. While similar to the influenza immunization rates of other health care professions, Ontario community pharmacists did not meet Public Health Canada's recommendations. Comprehensive worksite programs, including promotion, education and convenient access to influenza vaccination at no cost, could increase community pharmacist influenza vaccination rates. CONCLUSION: The authors issue a call to arms to encourage all pharmacists to receive the influenza vaccine to protect the public and themselves.

Janus Face Aspect of All-cis 1,2,3,4,5,6-Hexafluorocyclohexane Dictates Remarkable Anion and Cation Interactions In the Gas Phase.

Experiments have been carried out in which electrospray ionization has been used to generate ionic complexes of all-cis 1,2,3,4,5,6 hexafluorocyclohexane. These complexes were subsequently mass isolated in a quadrupole ion trap mass spectrometer and then irradiated by the tunable infrared output of a free electron laser in the 800-1600 cm(-1) range. From the frequency dependence of the fragmentation of the complexes, vibrational signatures of the complexes were obtained. Computational work carried out in parallel reveals that the complexes formed are very strongly bound and are among the most strongly bound complexes of Na(+) and Cl(-) ever observed with molecular species. The dipole moment calculated for the heaxafluorocyclohexane is very large (∼7 D), and it appears that the bonding in each of the complexes has a significant electrostatic contribution.

IL-10-producing B cells are induced early in HIV-1 infection and suppress HIV-1-specific T cell responses.

A rare subset of IL-10-producing B cells, named regulatory B cells (Bregs), suppresses adaptive immune responses and inflammation in mice. In this study, we examined the role of IL-10-producing B cells in HIV-1 infection. Compared to uninfected controls, IL-10-producing B cell frequencies were elevated in both blood and sigmoid colon during the early and chronic phase of untreated HIV-1 infection. Ex vivo IL-10-producing B cell frequency in early HIV-1 infection directly correlated with viral load. IL-10-producing B cells from HIV-1 infected individuals were enriched in CD19(+)TIM-1(+) B cells and were enriched for specificity to trimeric HIV-1 envelope protein. Anti-retroviral therapy was associated with reduced IL-10-producing B cell frequencies. Treatment of B cells from healthy donors with microbial metabolites and Toll-like receptor (TLR) agonists could induce an IL-10 producing phenotype, suggesting that the elevated bacterial translocation characteristic of HIV-1 infection may promote IL-10-producing B cell development. Similar to regulatory B cells found in mice, IL-10-producing B cells from HIV-1-infected individuals suppressed HIV-1-specific T cell responses in vitro, and this suppression is IL-10-dependent. Also, ex vivo IL-10-producing B cell frequency inversely correlated with contemporaneous ex vivo HIV-1-specific T cell responses. Our findings show that IL-10-producing B cells are induced early in HIV-1 infection, can be HIV-1 specific, and are able to inhibit effective anti-HIV-1 T cell responses. HIV-1 may dysregulate B cells toward Bregs as an immune evasion strategy.

Insight into the gas-phase structure of a copper(II) L-histidine complex, the agent used to treat Menkes disease.

Copper(II) L-histidine is used in the treatment of a rare neurological disease called Menkes disease. An infrared multiple photon dissociation (IRMPD) vibrational spectrum of the gas-phase copper(II) L-histidine complex has been obtained. This spectrum was compared to lowest-energy computational spectra obtained at the B3LYP/6-311+G** level of theory. Two species, CuHis1 and CuHis2, are very close in Gibbs free energy, and both have computed vibrational spectra in good agreement with the experimentally observed IRMPD spectrum. The first structure exhibits four histidine-copper interactions in the same plane and a fifth out-of-plane interaction. The second structure exhibits four histidine-copper interactions in the same plane. The fact that the experimental and computational spectra are found to be in good agreement adds considerable insight into the gas-phase structure of the copper(II) L-histidine complex.

Structural investigation of protonated azidothymidine and protonated dimer.

Infrared multiple photon dissociation (IRMPD) spectroscopy experiments and quantum chemical calculations have been used to explore the possible structures of protonated azidothymidine and the corresponding protonated dimer. Many interesting differences between the protonated and neutral forms of azidothymidine were found, particularly associated with keto-enol tautomerization. Comparison of computational vibrational and the experimental IMRPD spectra show good agreement and give confidence that the dominant protonated species has been identified. The protonated dimer of azidothymidine exhibits three intramolecular hydrogen bonds. The IRMPD spectrum of the protonated dimer is consistent with the spectrum of the most stable computational structure. This work brings to light interesting keto-enol tautomerization and exocyclic hydrogen bonding involving azidothymidine and its protonated dimer. The fact that one dominant protonated species is observed in the gas phase, despite both the keto and enol structures being similar in energy, is proposed to be the direct result of the electrospray ionization process in which the dominant protonated dimer structure dissociates in the most energetically favorable way.

Weak ion-molecule interactions in the gas phase: a high-pressure mass spectrometry and computational study of chloride-alkane interactions.

High-pressure mass spectrometric equilibrium experiments and electronic structure calculations have been carried out to investigate the energetics of the interactions of chloride ion with a series of normal alkanes and cycloalkanes in the gas phase. The structures of the complexes obtained from the electronic structure calculations provide considerable insight into the nature of the interaction between the negatively charged ion and the alkanes, which has the character of a purely ion-induced dipole interaction. The structural information also shows how the charged species affect the confirmation of the normal alkanes.

Energetics and structural elucidation of mechanisms for gas phase H/D exchange of protonated peptides.

Hydrogen/deuterium exchange reactions involving protonated triglycine and deuterated ammonia (ND(3)) have been examined in the gas phase using a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. Ab initio and density functional theory (DFT) calculations have been carried out to model the exchanges and to obtain energetics and vibrational frequencies for molecules involved in the proposed exchange mechanisms. Structural optimization and frequency calculations have been performed at the B3LYP level of theory with the 6-311+G(d,p) basis set. Transition states have been calculated at the same level of theory and basis set as above using the QST2 and QST3 methods. Single-point energy calculations have been performed at the MP2/6-311+G(d,p) level. Six labile sites of protonated triglycine were found to undergo H/D exchange. Of these six labile hydrogens, two are amide, three are ammonium, and one is carboxyl. Detailed mechanisms for each of these transfers are proposed. Qualitative onium ion and tautomer mechanisms for the exchanges of ammonium and amide hydrogens, respectively, using semiempirical calculations were suggested in previous studies by Beauchamp et al. As shown by the current ab initio and DFT calculations completed during this study, the mechanisms proposed in that study are notionally correct; however, the tautomer mechanisms are shown here to be the result of the fact that a second stable isomer of protonated triglycine exists in which the amide1 carbonyl oxygen is protonated. The exchange of the carboxyl hydrogen is found to proceed via a transition state resembling an ammonium ion interacting with a carboxylate moiety via two hydrogen bonds. The current work thus provides significant mechanistic and structural detail for a considerably more in-depth understanding of the processes involved in gas phase H/D exchange of peptides.