Synthesis of Trispirocyclotriphosphazenes with Oxaphosphorine Rings and Their Crystal and Molecular Structures.

Novel trispirocyclotriphosphazenes with oxaphosphorine rings (DOP-PZs) were successfully synthesized by an Appel reaction with phosphoramide, which was prepared from ammonia and 10-chloro-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide derived from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, generally abbreviated as DOPO. The resulting DOP-PZs were characterized by 1H, 13C{1H}, and 31P{1H} nuclear magnetic resonance spectroscopy and time-of-flight mass spectrometry and shown to consist of cis-trans isomers. Moreover, the crystal and molecular structures of the DOP-PZs were determined by X-ray diffraction; cis- and trans-DOP-PZs (C36H24N3O3P3, M = 639.49 g/mol) were refined to final R1 values of 0.0260 and 0.0463, respectively, with the SHELXL refinement package using least-squares minimization. The crystal of cis-DOP-PZ is trigonal in space group R3c and the following cell constants: a = 19.5984(5) Å, c = 13.2754(4) Å, V = 4415.9(3) Å3, Z = 6, and Flack parameter = 0.038(8). In contrast, trans-DOP-PZ is monoclinic in space group P21/c and the following cell constants: a = 9.98647(18) Å, b = 24.1737(4) Å, c = 12.8472(2) Å, ß = 112.649(8)°, V = 2862.26(18) Å3, and Z = 4. The molecular structures of these DOP-PZs were compared with those of other trispirocyclotriphosphazenes. In addition, the DOP-PZs showed high thermal stability up to 400 °C, with dielectric constants of 2.76-2.77 and dissipation factors of 0.0017-0.0031 at 10 GHz.

[A case of pneumococcal meningitis with reversible arterial stenosis].

A 72-year-old male was diagnosed pneumococcal meningitis and we started treatment with antibacterial drugs and corticosteroids. On the 6th day, his consciousness level decreased. On the 7th day DWI of MRI showed a new infarction in bilateral cerebellar, and MRA showed multiple arterial stenosis. On the 12th day, CT angiography showed expansion of cerebral infarction and progress of diffuse stenosis. After that the stenosis improved over time, it disappeared on the 39th day. These results suggest that vasospasm is involved in the pathology of vascular stenosis.

Usefulness of Transesophageal Echocardiography for Predicting Covert Paroxysmal Atrial Fibrillation in Patients with Embolic Stroke of Undetermined Source.

BACKGROUND: Covert paroxysmal atrial fibrillation (CPAF) is a major cause of embolic stroke of undetermined source (ESUS). However, detecting PAF during hospitalization in these patients is difficult. OBJECTIVES: This study aimed to determine whether findings of transesophageal echocardiography (TEE) during hospitalization are associated with later detection of PAF in patients with ESUS. METHOD: We retrospectively studied 348 patients with ESUS who were admitted to our hospital within 1 week of onset. These patients met the criteria of ESUS, underwent TEE during hospitalization, and were followed up for at least 1 year. RESULTS: We found PAF in 35 (10.0%) patients. In patients with PAF, spontaneous echo contrast (SEC) and low left atrial appendage flow (LAAF) by TEE and enlargement of the left atrial dimension (LAD) by transthoracic echocardiography were identified more frequently compared with those who did not have PAF. In multivariate analysis, SEC and an LAD ≥42 mm were independently associated with later detection of PAF (p < 0.05). An association of LAAF <46.9 cm/s and PAF was marginal (p = 0.09). The specificity of the combined finding of SEC and/or LAAF with that of LAD increased up to 90%, while that of LAD alone was 70%. CONCLUSIONS: The findings of TEE during hospitalization may be useful for identifying patients at increased risk of CPAF in patients with ESUS.

A case of cardioembolic stroke due to intracardiac papillary fibroelastoma evaluated by using transesophageal echocardiography.

A 62-year-old woman had a prior ischemic stroke in the right temporal lobe with dysarthria and dysesthesia of the left hand. Embolic stroke of undetermined source (ESUS) was diagnosed and warfarin was administered. However, transient ischemic attack recurred upon admission to our hospital. Paroxysmal atrial fibrillation and cerebral arterial stenotic lesions were absent. Transesophageal echocardiography revealed a mobile hyperechoic structure on the aortic valve indicating papillary fibroelastoma. She was diagnosed with a brain embolism due to the intracardiac tumor which was surgically excised and pathologically confirmed as papillary fibroelastoma. This type of tumor is relatively rare but it is important as an embolic source especially in ESUS. Transesophageal echocardiography was indispensable for detecting the embolic source in this patient with ESUS.