ALBERT

Description: There is little evidence linking eating speed to gestational diabetes mellitus (GDM) incidence. We therefore aimed to evaluate the prospective association of eating speed with GDM incidence. Overall, 97,454 pregnant women were recruited between January 2011 and March 2014. Singleton pregnant women who did not have GDM, heart disease, stroke, cancer, type 1 diabetes, and/or type 2 diabetes at the time of study enrollment were eligible. Each woman was asked about her eating speed at that time via a questionnaire. Odds ratios of GDM in relation to eating speed were obtained using logistic regression. Among the 84,811 women eligible for analysis, 1902 cases of GDM were identified in medical records. Compared with women who reported slow eating speed, the age-adjusted odds ratios (95% confidence interval) of GDM for women who reported medium, relatively fast, or very fast eating speed were 1.03 (0.90, 1.18), 1.07 (0.94, 1.23), and 1.28 (1.05, 1.58), respectively. Adjustment for demographic, lifestyle-related, and dietary factors including dietary fat, dietary fiber, and energy intakes yielded similar results. The association was attenuated and no longer significant after further adjustment for pre-pregnancy body mass index. The mediation analysis showed that being overweight accounted for 64% of the excess risk of GDM associated with eating speed. In conclusion, women who reported very fast eating speed, compared with those reporting slow eating speed, were associated with an increased incidence of GDM, which may be largely mediated by increased body fat.

Description: A three dimensionally magnetically oriented microcrystal array (3D-MOMA) is attractive to determination of a crystal structure as well as a molecular structure because it does not require a single crystal with sufficient size and quality for diffraction studies. We have developed a novel method to fabricate 3D-MOMA and determined several crystal structures using the 3D-MOMAs[1],[2]. However, the structure determination through MOMA requires a solidification treatment with UV curable monomer prior to X-ray diffraction experiment. We have developed a new X-ray diffractometer equipped with a magnetic field generator, which makes it possible to collect diffraction data without the solidification treatment. In this poster, we describe X-ray diffraction analyses of a magnetically oriented microcrystal suspension (MOMS) of L-alanine without the solidification treatment. A suspension of L-alanine microcrystals was poured in a glass capillary and rotated at a constant speed in a magnetic circuit attached in the X-ray diffractometer. Then, diffraction images were collected every 60 seconds. In the initial phase, the diffraction pattern showed a broad shape similar to that from a powder sample. As time goes on, diffraction patterns have gradually changed to single-crystal like patterns. After 2 hours, the shape of diffraction spots became as sharp as that of a single crystal. This observation shows that the microcrystals are oriented in the same direction. Owing to the improvement of the magnetic circuit and X-ray diffractometer, the quality of the diffraction has been greatly improved compared to that reported previously[3]. Further details of the analyses will be shown in the poster.

Description: Although folate deficiency was reported to be associated with hyperhomocysteinemia, influence of folate supplementation on cognition remains controversial. Therefore, we explored the effects of folate supplementation on the cognition and Homocysteine (Hcy) level in relatively short periods in patients with folate deficiency and cognitive impairment. Enrolled 45 patients (mean age of 79.7 ± 7.9 years old) with folate deficiency (

Description: We have proposed magnetically oriented microcrystal array (MOMA) technique as a new technique of crystal structure analysis. With this technique, single crystal X-ray diffraction analysis is made possible from a microcrystalline powder. Biaxial crystals, having three different values of magnetic susceptibility (χ1〉χ2〉χ3), are aligned three dimensionally under a frequency-modulated elliptical magnetic field. Biaxial microcrystal suspended in an ultraviolet (UV) light-curable monomer matrix is aligned three dimensionally under the magnetic field, followed by consolidation of the alignment by the photopolymerization the matrix. Biaxial crystal group has three crystal systems: orthorhombic, monoclinic and triclinic systems. The analysis of crystals belonging to the triclinic system is important because ca. 23 % of organic crystals are triclinic. We have so far succeeded in determining crystal structures of orthorhombic and monoclinic systems by using the MOMA technique[1, 2, 3] but crystals of triclinic system have not been examined yet. Therefore, in this report, we attempt to determine the crystal structure of D-arabinitol, belonging to the triclinic system, by using the MOMA technique. 10 wt% D-arabinitol / XVL14 (UV light-curable monomer) suspension was subjected to 8-T magnetic field (the speed of rotation changed between 10 rpm and 40 rpm at every 900) and was consolidated by irradiation of UV light. The prepared MOMA was subjected to the X-ray diffraction measurement. The obtained diffraction spots were well resolved and the average of half widths was about 3.90. These results indicate that the D-arabinitol microcrystals were aligned three dimensionally in the MOMA and the high quality of alignment was achieved. These results indicate that the obtained diffraction patterns are equivalent to those obtained from corresponding single crystal.

Description: In pharmaceutical sciences, the crystal structure is of primary importance because it influences drug efficacy. Due to difficulties of growing a large single crystal suitable for the single crystal X-ray diffraction analysis, powder diffraction method is widely used. In powder method, two-dimensional diffraction information is projected onto one dimension, which impairs the accuracy of the resulting crystal structure. To overcome this problem, we recently proposed a novel method of fabricating a magnetically oriented microcrystal array (MOMA), a composite in which microcrystals are aligned three-dimensionally in a polymer matrix. The X-ray diffraction of the MOMA is equivalent to that of the corresponding large single crystal, enabling the determination of the crystal lattice parameters and crystal structure of the embedded microcrytals.[1-3] Because we make use of the diamagnetic anisotropy of crystal, those crystals that exhibit small magnetic anisotropy do not take sufficient three-dimensional alignment. However, even for these crystals that only align uniaxially, the determination of the crystal lattice parameters can be easily made compared with the determination by powder diffraction pattern. Once these parameters are determined, crystal structure can be determined by X-ray powder diffraction method. In this paper, we demonstrate possibility of the MOMA method to assist the structure analysis through X-ray powder and single crystal diffraction methods. We applied the MOMA method to various microcrystalline powders including L-alanine, 1,3,5-triphenyl benzene, and cellobiose. The obtained MOMAs exhibited well-resolved diffraction spots, and we succeeded in determination of the crystal lattice parameters and crystal structure analysis.

Description: Solid-state NMR spectroscopy is one of the most widely used methods for investigating crystal structures, along with the X-ray and neutron diffraction methods. Solid-state NMR can provide structural information including isotropic chemical shift, dipolar and quadrupolar couplings, spin diffusion, and chemical shift tensor. Among these, the chemical shift tensor is of particular significance because the electronic environment around a nucleus is directly reflected on the chemical shift tensor. However, full information of the chemical shift tensor, including principal values and axes, is difficult to obtain experimentally because a large single crystal is required for the measurement. On the other hand, we have proposed the use of a magnetically oriented microcrystal array (MOMA) as an alternative to a single crystal.[1,2] A MOMA is a composite in which microcrystals are aligned three-dimensionally, prepared by using a time-dependent magnetic field. We recently demonstrated that the13C chemical shift tensors of L-alanine crystal can be completely determined by application of the standard procedure in the single-crystal rotation method to a MOMA of L-alanine microcrystals,[3] as shown in Figure 1. The L-alanine MOMA produces sharp resonance peaks without resolution enhancement by magic angle spinning (MAS). In addition, we observed that the positions of the13C resonance peaks vary systematically as a function of the angle ψ that is the sample-rotation angle about the axis inclined by the magic angle with respect to the NMR magnetic field. From the ψ-dependence of the chemical shifts,13C chemical shift tensor was completely determined. We confirmed that the combination of MOMA with the single-crystal rotation method can be applied to other nuclei such as31P and15N. These results clearly show that the MOMA method is a powerful tool for obtaining full information of the chemical shift tensor from a microcrystalline powder without MAS.

Description: Determination of lattice constants is a crucial process in analyzing powder diffraction data, affecting the robustness of analyses in subsequent steps. A number of algorithms and software based on them to predict lattice constants from powder data have been reported. In this study, we propose a novel experimental approach to facilitate unambiguous determination of the crystal systems and resulting lattice constants from a microcrystalline powder sample. Efforts have been made for partial recovery of crystal anisotropy from a complete random orientation in powder in order to facilitate the analysis of powder data. Our approach makes use of magnetic orientation[1-3] of microcrystals occurring due to the diamagnetic anisotropy inherent to crystal. By application of a static/or rotating magnetic field, the easy/or hard magnetization axes of microcrystals undergo uniaxial alignment, giving rise to two different fiber diffraction patterns. These patterns reflect the crystal symmetry, enabling us to discriminate the crystal system. Crystals of known crystal system were pulverized and their suspensions were prepared. Each suspension was subjected to a static/or rotating magnetic field and the X-ray diffraction measurement was performed in situ to obtain two fiber diffraction patterns. It is evident that isotropic crystals only produce ring patterns for static and rotating measurement. On the other hand, biaxial crystals exhibit sharp diffraction spots in both fiber patterns. Furthermore, these fiber patterns exhibit layer lines in both patterns for the orthorhombic system, no layer lines for triclinic system, etc. In addition, overlapping of peaks in one-dimensional powder pattern can be resolved by indexing the spots in two dimensions of fiber patterns.

Description: We have developed magnetically oriented microcrystal array (MOMA) technique that enables single crystal X-ray diffraction analyses from microcrystalline powder. In this method, microcrystals suspended in a UV-curable monomer matrix are there-dimensionally aligned by special rotating magnetic field, followed by consolidation of the matrix by photopolymerization. From thus achieved MOMAs, we have been succeeded in crystal structure analysis for some substances [1, 2]. Though MOMA method is an effective technique, it has some problems as follows: in a MOMA, the alignment is deteriorated during the consolidation process. In addition, the sample microcrystals cannot be recovered from a MOMA. To overcome these problems, we performed an in-situ X-ray diffraction measurement using a three-dimensional magnetically oriented microcrystal suspension (3D MOMS) of L-alanine. An experimental setting of the in-situ X-ray measurement of MOMS is schematically shown in the figure. L-alanine microcrystal suspension was poured into a glass capillary and placed on the rotating unit equipped with a pair of neodymium magnets. Rotating X-ray chopper with 10°-slits was placed between the collimator and the suspension. By using this chopper, it was possible to expose the X-ray only when the rotating MOMS makes a specific direction with respect to the impinging X-ray. This has the same effect as the omega oscillation in conventional single crystal measurement. A total of 22 XRD images of 10° increments from 0° to 220° were obtained. The data set was processed by using conventional software to obtain three-dimensional molecular structure of L-alanine. The structure is in good agreement with that reported for the single crystal. R1 and wR2 were 6.53 and 17.4 %, respectively. RMSD value between the determined molecular structure and the reported one was 0.0045 Å. From this result, we conclude that this method can be effective and practical to be used widely for crystal structure analyses.

Description: Elucidation of the three-dimensional structure of biomolecules is of great importance because the three-dimensional structure is closely related to biological functions. X-ray single-crystal analysis is powerful method to analyze the structure, but it is sometimes difficult to grow a crystal sufficiently large for conventional or even synchrotron single-crystal X-ray measurement. We recently reported on a magnetically oriented microcrystal array (MOMA) [1] that is a composite in which microcrystals are aligned three-dimensionally in polymer matrix. Microcrystals are suspended in an ultraviolet-curable monomer and rotated non-uniformly in a static magnetic field to achieve three dimensional crystal alignment. Then, the monomer is photopolymerized to maintain the achieved alignment. We have successfully demonstrated that X-ray single crystal structure determinations through MOMA are possible for low molecular weight compounds [2] as well as protein. [3] However, the method with MOMA has two drawbacks: (i) the sample microcrystals cannot be recovered from a MOMA, which is especially serious problem in case of proteins, and (ii) the alignment is deteriorated during the consolidation process, causing low resolution. In this study, we attempt to solve these problems. First, we use a water-soluble sol as microcrystalline media and consolidate the alignment by gelation, which makes the recovery of microcrystals possible. Second, a magnetically oriented microcrystal suspension (MOMS) is used for in-situ X-ray diffraction measurement, which makes the sample recovery possible and enhances the resolution. We use lysozyme as a model protein for both cases. The in-situ method with in-house X-ray diffractometer gave diffraction spots about 3.0 Å resolutions. We plan to perform the same experiment at SPring-8.

Description: Immunoglobulin A (IgA)-albumin complexes may be associated with pathophysiology of multiple myeloma, although the etiology is not clear. Detailed structural analyses of these protein–protein complexes may contribute to our understanding of the pathophysiology of this disease. We analyzed the structure of the IgA-albumin complex using various electrophoresis, mass spectrometry, and in silico techniques. The data based on the electrophoresis and mass spectrometry showed that IgA in the sera of patients was dimeric, linked via the J chain. Only dimeric IgA can bind to albumin molecules leading to IgA-albumin complexes, although both monomeric and dimeric forms of IgA were present in the sera. Molecular interaction analyses in silico implied that dimeric IgA and albumin interacted not only via disulfide bond formation, but also via noncovalent bonds. Disulfide bonds were predicted between Cys34 of albumin and Cys311 of IgA, resulting in an oxidized form of albumin. Furthermore, complex formation prolongs the half-life of IgA molecules in the IgA-albumin complex, leading to excessive glycation of IgA molecules and affects the accumulation of IgA in serum. These findings may demonstrate why complications such as hyperviscosity syndrome occur more often in patients with IgA dimer producing multiple myeloma.