Cutaneous syncytial myoepithelioma with folliculocentric growth and EWSR1 gene rearrangement: A case report.

Cutaneous syncytial myoepithelioma is a tumor type that was initially reported in 2013 as a syncytial variant of cutaneous myoepithelioma characterized by intradermal nodular proliferation of oval to spindle-shaped tumor cells in solid and syncytial patterns. Fusion of genes Ewing sarcoma breakpoint region 1 / EWS RNA binding protein 1 (EWSR1) and pre-B cell leukemia homeobox 3 (PBX3) is found in approximately 90% of the cases. We report a case of cutaneous syncytial myoepithelioma with diagnostic difficulty due to folliculocentric morphology and atypical immunohistochemical results, including diffuse positivity of α-smooth muscle actin and claudin 4 and negative immunoreactions for epithelial membrane antigen and S100 protein. In the present case, fluorescence in situ hybridization study demonstrated EWSR1 rearrangement. We further provide a discussion of differential diagnoses with a review of relevant literature.

A case report of fulminant type 1 diabetes mellitus associated with drug-induced hypersensitivity syndrome in an elderly patient with coxsackie B4 virus infection and human leukocyte antigen-A24 haplotype.

Drug-induced hypersensitivity syndrome (DIHS) is a severe systemic adverse drug reaction. Previous studies showed that DIHS is associated with the onset of fulminant type 1 diabetes mellitus (FT1D). Although genetic background and abnormalities in immune response or viral infection are considered to be associated with pathogenesis of FT1D, it remains unclear whether virus infection and specific human leukocyte antigen (HLA) typing are involved in DIHS-associated FT1D. Here, we report a case of a 78-year-old female patient with FT1D after DIHS treatment. She was diagnosed as DIHS caused by carbamazepine, and treatment with predonisolone was initiated. After 46 days from the occurrence of DIHS, she was admitted to our hospital because of type 1 diabetes mellitus and diabetic ketoacidosis. Although her Hemoglobin A1c (HbA1c) was elevated by predonisolone treatment (HbA1c: 9.2%), we diagnosed her as fulminant type 1 diabetes mellitus considering the abrupt onset of the ketoacidosis. Her general condition was improved by treatment with fluid infusion and insulin administration. During her clinical course, the infection of coxsackie B4 virus was observed. In addition, the examination of HLA typing showed HLA-A24 haplotype. These findings suggest that the coxsackie B4 virus infection may be involved in the pathogenesis of DIHS-induced FT1D, and that HLA-A24 haplotype might relate to DIHS-associated FT1D.

Evaluation of irradiation effects of near-infrared free-electron-laser of silver alloy for dental application.

In the application of lasers in dentistry, there is a delicate balance between the benefits gained from laser treatment and the heat-related damage arising from laser irradiation. Hence, it is necessary to understand the different processes associated with the irradiation of lasers on dental materials. To obtain insight for the development of a safe and general-purpose laser for dentistry, the present study examines the physical effects associated with the irradiation of a near-infrared free-electron laser (FEL) on the surface of a commonly used silver dental alloy. The irradiation experiments using a 2900-nm FEL confirmed the formation of a pit in the dental alloy. The pit was formed with one macro-pulse of FEL irradiation, therefore, suggesting the possibility of efficient material processing with an FEL. Additionally, there was only a slight increase in the silver alloy temperature (less than 0.9 °C) despite the long duration of FEL irradiation, thus inferring that fixed prostheses in the oral cavity can be processed by FEL without thermal damage to the surrounding tissue. These results indicate that dental hard tissues and dental materials in the oral cavity can be safely and efficiently processed by the irradiation of a laser, which has the high repetition rate of a femtosecond laser pulse with a wavelength around 2900 nm.

Degradation of Lignin by Infrared Free Electron Laser.

Lignin monomers have attracted attention as functional materials for various industrial uses. However, it is challenging to obtain these monomers by degrading polymerized lignin due to the rigid ether linkage between the aromatic rings. Here, we propose a novel approach based on molecular vibrational excitation using infrared free electron laser (IR-FEL) for the degradation of lignin. The IR-FEL is an accelerator-based pico-second pulse laser, and commercially available powdered lignin was irradiated by the IR-FEL under atmospheric conditions. Synchrotron-radiation infrared microspectroscopy analysis showed that the absorption intensities at 1050 cm-1, 1140 cm-1, and 3400 cm-1 were largely decreased alongside decolorization. Electrospray ionization mass chromatography analysis showed that coumaryl alcohol was more abundant and a mass peak corresponding to hydrated coniferyl alcohol was detected after irradiation at 2.9 µm (νO-H) compared to the original lignin. Interestingly, a mass peak corresponding to vanillic acid appeared after irradiation at 7.1 µm (νC=C and νC-C), which was supported by our two-dimensional nuclear magnetic resonance spectroscopy analysis. Therefore, it seems that partial depolymerization of lignin can be induced by IR-FEL irradiation in a wavelength-dependent manner.

Observation of terahertz coherent edge radiation amplified by infrared free-electron laser oscillations.

A coupling device, which can extract coherent edge radiation (CER) from an optical cavity for a free-electron laser (FEL) without damaging the FEL due to diffraction loss, was developed at Nihon University. We successfully observed the CER beam with a power of 1 mW or more in the terahertz range during FEL oscillation. It is revealed that the CER power changed with the detuning of the optical cavity and the dependence of the CER power on the detuning length differs from that of the FEL power. The measured CER spectra indicate that the longitudinal electron distribution in a bunch is modulated by the FEL oscillation with a period corresponding to the FEL slippage length. We herein report the characteristics of the CER with FEL oscillation in detail. These results demonstrate that the CER is excellent tool to reveal the overall effect of FEL interaction on electron distribution in a bunch.