Co-existence of Distinct Supramolecular Assemblies in Solution and in the Solid State.

The formation of distinct supramolecular assemblies, including a metastable species, is revealed for a lipophilic guanosine (G) derivative in solution and in the solid state. Structurally different G-quartet-based assemblies are formed in chloroform depending on the nature of the cation, anion and the salt concentration, as characterized by circular dichroism and time course diffusion-ordered NMR spectroscopy data. Intriguingly, even the presence of potassium ions that stabilize G-quartets in chloroform was insufficient to exclusively retain such assemblies in the solid state, leading to the formation of mixed quartet and ribbon-like assemblies as revealed by fast magic-angle spinning (MAS) NMR spectroscopy. Distinct N-H⋅⋅⋅N and N-H⋅⋅⋅O intermolecular hydrogen bonding interactions drive quartet and ribbon-like self-assembly resulting in markedly different 2D 1 H solid-state NMR spectra, thus facilitating a direct identification of mixed assemblies. A dissolution NMR experiment confirmed that the quartet and ribbon interconversion is reversible-further demonstrating the changes that occur in the self-assembly process of a lipophilic nucleoside upon a solid-state to solution-state transition and vice versa. A systematic study for complexation with different cations (K+ , Sr2+ ) and anions (picrate, ethanoate and iodide) emphasizes that the existence of a stable solution or solid-state structure may not reflect the stability of the same supramolecular entity in another phase.

Contribution of glucose to crystallization of phenytoin in injectable dosage form by dilution with infusion fluids.

The crystallization of phenytoin occurring after its dilution with infusion fluid is a major concern in the clinical use of injectable phenytoin. To gain further understanding of the crystallization, this study assessed details of the involvement of glucose in this action. For sample preparation, phenytoin crystals were created by diluting the injectable phenytoin with infusion fluids with different glucose concentrations at different temperature, and then the characteristics of the crystallization (e.g., crystal size in the long direction, accumulated amount over 24 h, and crystallization rate constant) were measured. Results of the analysis of variance indicated that the glucose concentration and temperature had significant impacts on the crystallization. The mode of action of the glucose concentration was suggested to be different from that of the incubation temperature. This study also examined the molecular mobility of components (i.e., glucose, propylene glycol, phenytoin) in the admixtures using diffusion NMR techniques. The findings will provide valuable information for the clinical use of injectable phenytoin.

Nursing Home Versus Community Resuscitation After Cardiac Arrest: Comparative Outcomes and Risk Factors.

OBJECTIVE: To investigate the characteristics and outcomes of patients who experienced cardiac arrest in nursing homes compared with those in private residences and determine prognostic factors for survival. DESIGN: This was a retrospective study that analyzed data from an Utstein-style registry of the Tokyo Fire Department. SETTING AND PARTICIPANTS: We identified patients aged ≥65 years who experienced cardiac arrest in a nursing home or private residence from the population-based registry of out-of-hospital cardiac arrests in Tokyo, Japan, from 2014 to 2018. METHODS: Patients were grouped into the nursing home or the private residence groups according to their cardiac arrest location. We compared the characteristics and outcomes between the 2 groups and determined prognostic factors for survival in the nursing home group. The primary outcome was 1-month survival after cardiac arrest. RESULTS: In total, 37,550 patient records (nursing home group = 6271; private residence group = 31,279) were analyzed. Patients in the nursing home group were significantly older and more often had witnessed arrest, bystander cardiopulmonary resuscitation (CPR), and shock delivery using an automated external defibrillator. The 1-month survival rate was significantly higher in the nursing home group (2.6% vs 1.8%, P < .001). In the best scenario (daytime emergency call, witnessed cardiac arrest, bystander CPR provided), the 1-month survival rate after cardiac arrest in the nursing home group was 8.0% (95% confidence interval 6.4-9.9%), while none survived if they had neither witness nor bystander CPR. CONCLUSIONS AND IMPLICATIONS: Survival outcome was significantly better in the nursing home group than in the private residence group and was well stratified by 3 prognostic factors: emergency call timing, witnessed status, and bystander CPR provision. Our results suggest that a decision to withhold vigorous treatment solely based on nursing home residential status is not justified, while termination of resuscitation may be determined by considering significant prognostic factors.

Effectiveness of public-access automated external defibrillators at Tokyo railroad stations.

AIM: To investigate the effectiveness of public-access automated external defibrillators (AEDs) at Tokyo railroad stations. METHODS: We analysed data from a population-based registry of out-of-hospital cardiac arrests in Tokyo, Japan (2014-2018). We identified patients aged ≥18 years who experienced bystander-witnessed cardiac arrest due to ventricular fibrillation of presumed cardiac origin at railroad stations. The primary outcome was survival at 1 month after cardiac arrest with favourable neurological outcomes (cerebral performance category 1-2). RESULTS: Among 280 eligible patients who had bystander-witnessed cardiac arrest and received defibrillation at railroad stations, 245 patients (87.5%) received defibrillation using public-access AEDs and 35 patients (12.5%) received defibrillation administered by emergency medical services (EMS). Favourable neurological outcomes at 1 month after cardiac arrest were significantly more common in the group that received defibrillation using public-access AEDs (50.2% vs. 8.6%; adjusted odds ratio: 11.2, 95% confidence interval: 1.43-88.4) than in the group that received defibrillation by EMS. Over a 5-year period, favourable neurological outcomes at 1 month after cardiac arrest of 101.9 cases (95% confidence interval: 74.5-129.4) were calculated to be solely attributable to public-access AED use. The incremental cost-effectiveness ratio to gain one favourable neurological outcome obtained from public-access AEDs at railroad stations was lower than that obtained from nationwide deployment (48.5 vs. 2133.4 AED units). CONCLUSION: Deploying public-access AEDs at Tokyo railroad stations presented significant benefits and cost-effectiveness. Thus, it may be prudent to prioritise metropolitan railroad stations in public-access defibrillation programs.

Mechanism for the direct synthesis of tryptophan from indole and serine: a useful NMR technique for the detection of a reactive intermediate in the reaction mixture.

The reaction mechanism for the biomimetic synthesis of tryptophan from indole and serine in the presence of Ac(2)O in AcOH was investigated. Although the time-course (1)H-NMR spectra of the reaction of 5-methoxyindole with N-acetylserine were measured in the presence of (CD(3)CO)(2)O in CD(3)CO(2)D, the reactive intermediate could not be detected. This reaction was conducted without 5-methoxyindole in order to elucidate the reactive intermediate, but the intermediate could not be isolated from the reaction mixture. Since the intermediate would be expected to have a very short life time, and therefore be very difficult to detect by conventional analytical methods, the structure of the intermediate was elucidated using a 2D-NMR technique, diffusion-ordered spectroscopy (DOSY). Two intermediates were detected and confirmed to be 2-methyl-4-methyleneoxazol-5(4H)-one and 2-methyl-4-hydroxymethyloxazol-5(4H)-one. The present results demonstrated that DOSY is a powerful tool for the detection of unstable intermediates.

Experimental study of antiangiogenic gene therapy targeting VEGF in oral cancer.

It is well known that tumor angiogenesis plays an important role in local growth and metastasis of oral cancer; therefore, inhibiting angiogenesis is considered to be effective for treating oral cancer. This study aimed to investigate the effectiveness of systemically available antiangiogenic gene therapy targeting vascular endothelial growth factor (VEGF), which is one of the most important angiogenesis accelerators. We administered a soluble form of VEGF receptor-expressing gene incorporated into adenovirus (AdVEGF-ExR) intraperitoneally to nude mice to which oral cancer cell lines (SAS, HSC-3, and Ca9-22) had been transplanted subcutaneously in vivo to inhibit angiogenesis and tumor proliferation. Then, we measured tumor volumes over time, and tumors were enucleated and examined histopathologically and immunohistologically at 28 days after AdVEGF-ExR administration. Compared to the controls to which we administered AdLacZ or saline, significant antiproliferative effects were observed (P < 0.05) in the AdVEGF-ExR administration group, and extensive tumor necrosis was found histopathologically. Immunohistochemical analysis with CD34 (NU-4A1) revealed tumor angiogenesis was suppressed significantly (P < 0.05), and that with ssDNA revealed apoptosis induction was significantly high (P < 0.05) in the AdVEGF-ExR group. However, analysis with Ki-67 (MIB-1) revealed tumor proliferative capacity was not significantly different between the groups. Consequently, we consider that AdVEGF-ExR administration achieved tumor growth suppression by inhibiting angiogenesis and inducing apoptosis, but not by inhibiting the proliferative capacity of tumor cells. Neither topical administration of a soluble form of VEGF receptor (sVEGFR) to the tumor nor a megadose was needed to achieve this inhibition effect. These results suggest gene therapy via sVEGFR would be an effective oral cancer therapy and benefit future clinical applications.

Development of an NMR interface microchip "MICCS" for direct detection of reaction products and intermediates of micro-syntheses using a "MICCS-NMR".

The development of an NMR interface microchip and its applications to the real-time monitoring of chemical reactions are described. The microchip device was named "MICCS" (MIcro Channeled Cell for Synthesis monitoring), and the method using it was named "MICCS-NMR". MICCS was inserted into a 5 mm Phi NMR sample tube. Thus standard solution NMR probes without any modifications can be used in MICCS-NMR measurements. A gap between MICCS and the sample tube was filled with a deuterated solvent for an NMR lock. The reaction temperature and reaction time in MICCS can be easily changed by adjusting the temperature of the NMR probe and changing the flow rates, respectively. The effectiveness of the MICCS-NMR was verified in the real-time monitoring of the Wittig reaction. Preliminary data on the direct detection of intermediates of the Grignard reaction is also reported. Besides real-time monitoring of chemical reactions, MICCS-NMR would be useful as a qualitative detection method for microchip-based synthesis.

Observation of 1,6-anhydro-beta-maltose and 1,6-anhydro-beta-D-glucopyranose complexed with rubidium by NMR spectroscopy and electrospray ionization mass spectrometry.

A complex of 1,6-anhydro-beta-maltose with rubidium and that of 1,6-anhydro-beta-D-glucopyranose with rubidium were characterized using 87Rb NMR spectroscopy, diffusion-ordered NMR spectroscopy (DOSY) and electrospray ionization mass spectrometry (ESI-MS). Although subtle differences were observed in the 1H chemical shifts of 1,6-anhydro-beta-maltose in between the presence and absence of rubidium in deuterium oxide, measurements of the spin-lattice relaxation time (T1) of the 87Rb nucleus, the diffusion coefficients of 1,6-anhydro-beta-maltose using 1H DOSY and ESI-MS indicated the complex formation of 1,6-anhydro-beta-maltose with rubidium. The complex formation with rubidium was also identified for 1,6-anhydro-beta-D-glucopyranose using NMR and ESI-MS techniques.

Application of the 19F NMR technique to observe binding of the general anesthetic halothane to human serum albumin.

19F NMR techniques were employed to characterize the binding property of the widely used general anesthetic halothane with human serum albumin (HSA). It was found that 19F(1H) NOE and 2D 1H-19F HOESY experiments detected intermolecular NOEs between halothane 19F and HSA protons. Measurements of the diffusion coefficients for halothane were also carried out by 1H and 19F NMR, indicating the interaction of halothane with HSA. The present results indicate that these techniques are very suitable to identify a fluorine-containing ligand binding with a protein receptor in the drug-discovery process.

Direct observation of the unstable intermediates in radical addition reaction by using an interfacing microchip combined with an NMR.

Direct observation of the unstable intermediate in the radical addition reaction of the oxime ether 1 mediated by triethylborane (Et(3)B) is described using (1)H and (11)B micro channeled cell for synthesis monitoring (MICCS), which was recently developed as an interfacing microchip for NMR. It was possible that the signal of the intermediate was observed as a result of using MICCS technique with a standard NMR instrument. This result supports the structure of the intermediate analyzed by diffusion-ordered spectroscopy (DOSY) NMR method in a previous paper. The procedure of micro channeled cell for synthesis monitoring-nuclear magnetic resonance (MICCS-NMR) was much easier than that of DOSY method. It was proven that it could be applied to the reaction in an anhydrous condition.

Structure elucidation of the intermediate in triethylborane-mediated radical addition of oxime ethers with 2D- and 3D-DOSY NMR.

The structures of the components in the triethylborane-mediated radical addition reaction of oxime ether were investigated by 1H- and 3D-DOSY NMR methods. It has been impossible to physically separate the unstable intermediates; therefore, the structures were thus far unidentified. It has been possible to elucidate the structures of these unstable intermediates using Diffusion-Ordered Spectroscopy (DOSY) methods for the reaction in an NMR tube. The DOSY methods resolved the spectra of each starting compound, intermediate and product having different diffusion coefficients. The structure of the intermediate was shown to be due to the bonding of diethylborane to the nitrogen atom of the alkoxyamino group.