Cardiac Conduction Disorders as Markers of Cardiac Events in Myotonic Dystrophy Type 1.

Background Myotonic dystrophy type 1 involves cardiac conduction disorders. Cardiac conduction disease can cause fatal arrhythmias or sudden death in patients with myotonic dystrophy type 1. Methods and Results This study enrolled 506 patients with myotonic dystrophy type 1 (aged ≥15 years; >50 cytosine-thymine-guanine repeats) and was treated in 9 Japanese hospitals for neuromuscular diseases from January 2006 to August 2016. We investigated genetic and clinical backgrounds including health care, activities of daily living, dietary intake, cardiac involvement, and respiratory involvement during follow-up. The cause of death or the occurrence of composite cardiac events (ie, ventricular arrhythmias, advanced atrioventricular blocks, and device implantations) were evaluated as significant outcomes. During a median follow-up period of 87 months (Q1-Q3, 37-138 months), 71 patients expired. In the univariate analysis, pacemaker implantations (hazard ratio [HR], 4.35; 95% CI, 1.22-15.50) were associated with sudden death. In contrast, PQ interval ≥240 ms, QRS duration ≥120 ms, nutrition, or respiratory failure were not associated with the incidence of sudden death. The multivariable analysis revealed that a PQ interval ≥240 ms (HR, 2.79; 95% CI, 1.9-7.19, P<0.05) or QRS duration ≥120 ms (HR, 9.41; 95% CI, 2.62-33.77, P < 0.01) were independent factors associated with a higher occurrence of cardiac events than those observed with a PQ interval <240 ms or QRS duration <120 ms; these cardiac conduction parameters were not related to sudden death. Conclusions Cardiac conduction disorders are independent markers associated with cardiac events. Further investigation on the prediction of occurrence of sudden death is warranted

Pairwise Packing of Anthracene Fluorophore: Hydrogen-Bonding-Assisted Dimer Emission in Solid State

Anthracene derivatives possessing a carbamate group and an ester group at their 9- and 10-positions, respectively, were prepared to furnish pairwise packing of anthracene fluorophores in their crystal structures. They were nonluminescent in ethanol solution and showed AIE (aggregation-induced emission) in aqueous ethanol solution and in solid state. Crystal structure analysis of them showed that the H-bonding networks involved in their crystal structures could be classified into four patterns, H-bonding between the carbamate and the ester carbonyl (motif A), H-bonding between the carbamate and the ester oxygen atom (motif B), H-bonded cyclic dimer of carbamate moieties (motif C), and H-bonded chain among carbamate moieties (motif D). Compounds with pairwisely packed anthracene fluorophores showed dimer emission with the longer fluorescence wavelength than others without the pair formation. Fluorescence maximum wavelengths and lifetimes become longer proportional to the degree of overlapping of two facing anthracene π-planes

Conformation-Directed Hydrogen-Bonding in <i>meta</i>-Substituted Aromatic Ureadicarboxylic Acid: A Conformationally Flexible U‑Shaped Building Block

Crystal structures of U-shaped aromatic ureadicarboxylic acid possessing two carboxy moieties at <i>meta</i>-positions of phenyl rings were investigated. It afforded cocrystals with dipyridyl derivatives. In addition to the U-shaped conformation obtained by recrystallization from methanol, another three types of U-shaped conformations were found in the crystal structure of the cocrystals. The direction of H-bonding was fixed based on the relative geometry of two carboxy moieties in the resulting conformations. Depending on these conformations, triple helices with one-dimensional water channels, infinite cross-belt, and step-like structures were generated via H-bonding between the carboxy and the pyridyl moieties. Methanol solvate was obtained for the cocrystal with 1,4-di­(pyridine-4-yl)­benzene which showed different U-shaped conformation of urea dicarboxylic acid from that involved in the cocrystal free of methanol

Crystal Structures of S‑Shaped Phenylenediurea Dibenzoic Acids and Their Cocrystals with Melamine: Unusual Zigzag Tape of H‑Bonded Melamine Network

Phenylenediurea dibenzoic acid derivatives <b>1</b>, <b>2</b>, <b>3</b>, and <b>5</b> and an amide derivative <b>4</b> were synthesized, and their molecular structures were elucidated to be an S-shape by single crystal X-ray analysis. Crystals of <b>1</b> were obtained as a DMF solvate, while those of <b>2</b> and <b>3</b> were not. Sheet and ladder structures were created in the crystal packing of <b>1</b> and <b>3</b>, and <b>2</b>, respectively. Unlike the para-substituted diureas <b>1</b>–<b>3</b> which possessed meso-conformation, the meta-substituted diurea <b>5</b> exhibited helical-conformation in its crystal structure. The way of crystal packing of <b>4</b> is analogous to that of the corresponding dicarboxylic acid derivative <b>2</b>. A water cluster of a chair-shaped hexagonal array of water molecules was created in the crystal structure of <b>4</b>. Diureas <b>1</b> and <b>2</b> gave cocrystals with melamine recrystallized from DMF/ethyl acetate and DMF/H₂O, respectively. Unusual zigzag tapes of a H-bonding network of melamine were created in both cocrystals. The zigzag tapes were connected with S-shaped diureas by H-bonding to furnish an interpenetrated fishnet-type crystal structure

Piezoluminescence and Liquid Crystallinity of 4,4′-(9,10-Anthracenediyl)bispyridinium Salts

Piezoluminescence and liquid crystallinity of anthracene-based bispyridinium salts were investigated in stimulus-responsive luminescent organic crystals and luminescent ionic liquid crystals. The salts possess an anthracene moiety as a fluorophore in their center, and the pyridiniums attached to the anthracene moiety are substituted with trialkoxybenzyl groups. Single crystals of the salts bearing two trimethoxybenzyl groups were obtained as solvates. Ethyl acetate, acetone, and dioxane solvates of the chlorides have almost the same crystal structures with one-dimensional channels. Grinding of the solvated crystals caused the extrusion of the included solvent molecules, which resulted in the red shifts of their fluorescence in the solid state. The dimethyl sulfoxide solvate of the hexafluorophosphate also showed piezoluminescene by grinding. Tris­(octyloxy)­benzyl and tris­(dodecyloxy)­benzyl derivatives exhibited rectangular columnar liquid crystals upon being heated for their bromide and tetrafluoroborate salts and upon being cooled for their hexafluorophosphate salts. Of these pyridinium salts, hexafluorophosphates showed characteristic solvent-dependent fluorescence