Development of 3D CAD/FEM Analysis System for Natural Teeth and Jaw Bone Constructed from X-Ray CT Images

A three-dimensional finite element model of the lower first premolar, with the three layers of enamel, dentin, and pulp, and the mandible, with the two layers of cortical and cancellous bones, was directly constructed from noninvasively acquired CT images. This model was used to develop a system to analyze the stresses on the teeth and supporting bone structure during occlusion based on the finite element method and to examine the possibility of mechanical simulation

Successful Treatment of Oral Lichen Planus with Direct-Acting Antiviral Agents after Liver Transplantation for Hepatitis C Virus-Associated Hepatocellular Carcinoma

Hepatitis C virus (HCV) infection is frequently associated with various extrahepatic manifestations, such as autoimmune features and immune complex deposit diseases. Oral lichen planus (OLP) is one such extrahepatic manifestation of HCV infection. Recently, direct-acting antivirals (DAA) have proved to be highly effective and safe for the eradication of HCV. Herein, we report a case of OLP accompanied by HCV-related hepatocellular carcinoma (HCC) that disappeared after liver transplantation and achievement of sustained virological response following interferon (IFN)-free treatment with ledipasvir (LDV) and sofosbuvir (SOF). The 50-year-old patient developed erosive OLP during IFN therapy, with hyperthyroidism at 53 years of age and HCC at 55 years. He received immunosuppressive drugs and IFN-free DAA treatment after liver transplantation at 60 years of age, which led to disappearance of the symptoms of OLP. The patient was treated safely and effectively with LDV/SOF, although it is not known whether the disappearance of OLP resulted from the eradication of HCV or the immunosuppressive therapy

Conformational Changes in the N-Terminal Region of Photoactive Yellow Protein: A Time-Resolved Diffusion Study

The kinetics of conformational change in the N-terminal region of photoactive yellow protein (PYP) was studied by the time-resolved diffusion measurement. The transient grating signal that represented the protein diffusion of the ground state and pB state depended on the observation time range. An analysis of the signal based on the time-dependent diffusion coefficient clearly showed that protein diffusion changed with a time constant of 170 μs, corresponding to the pR2 → pB′ transition. Since a previous diffusion study of N-terminal truncated PYPs had revealed that the change in the diffusion coefficient reflected the unfolding of the α-helices in the N-terminal region of PYP, the results indicate that this unfolding took place at the same rate as the pR2 → pB′ transition. This demonstrates that the response of the conformational change in the N-terminal region was quite fast, probably due to changes in a specific hydrogen-bonding network of this domain