Supershear Rayleigh wave imaging for quantitative assessment of biomechanical properties of brain using air-coupled optical coherence elastography.

Recently, supershear Rayleigh waves (SRWs) have been proposed to characterize the biomechanical properties of soft tissues. The SRWs propagate along the surface of the medium, unlike surface Rayleigh waves, SRWs propagate faster than bulk shear waves. However, their behavior and application in biological tissues is still elusive. In brain tissue elastography, shear waves combined with magnetic resonance elastography or ultrasound elastography are generally used to quantify the shear modulus, but high spatial resolution elasticity assessment in 10 µm scale is still improving. Here, we develop an air-coupled ultrasonic transducer for noncontact excitation of SRWs and Rayleigh waves in brain tissue, use optical coherent elastography (OCE) to detect, and reconstruct the SRW propagation process; in combing with a derived theoretical model of SRWs on a free boundary surface, we quantify the shear modulus of brain tissue with high spatial resolution. We first complete validation experiments using a homogeneous isotropic agar phantom, and the experimental results clearly show the SRW is 1.9649 times faster than the bulk shear waves. Furthermore, the propagation velocity of SRWs in both the frontal and parietal lobe regions of the brain is all 1.87 times faster than the bulk shear wave velocity. Finally, we evaluated the anisotropy in different brain regions, and the medulla oblongata region had the highest anisotropy index. Our study shows that the OCE system using the SRW model is a new potential approach for high-resolution assessment of the biomechanical properties of brain tissue.

Application of a Caries Treatment Difficulty Assessment System in Dental Caries Management.

Dental caries is one of the most common chronic diseases caused by progressive bacteria, affecting all age groups. Today, restorative fillings are widely used for dental caries treatment, but the restorative treatment has a high failure rate. Meanwhile, many researchers have discovered the differences of caries risk among populations by using the caries risk assessment and put forward a new standpoint that caries should be treated individually. Therefore, our research group established a Dental Caries Treatment Difficulty Assessment system in a previous study. This time, we combined the caries risk assessment with the caries treatment difficulty assessment, then used Python to design a Dental Caries Management Software. The purpose of this case report is to present a case applying this software in dental caries management and other data collected in Chengdu, China, with this software on the assessment of caries treatment difficulty. Patients with personalized assessment and management can achieve good treatment results, including reducing the risk and treatment difficulty of dental caries. At the same time, other cases show that the software has good application potential in individual management and group information collection. These cases indicate that the software enables dentists to carry out both the risk assessments and the treatment difficulty assessment of patients, and it has the potential as a tool for epidemiological investigation. It also enables dentists and patients to have a basic understanding of the dental health status of patients and create personalized dental caries treatment, so as to achieve the goal of controlling the progression of dental caries and rebuilding the structure and restoring the function of teeth.

Assessment of a novel VEGF targeted agent using patient-derived tumor tissue xenograft models of colon carcinoma with lymphatic and hepatic metastases.

The lack of appropriate tumor models of primary tumors and corresponding metastases that can reliably predict for response to anticancer agents remains a major deficiency in the clinical practice of cancer therapy. It was the aim of our study to establish patient-derived tumor tissue (PDTT) xenograft models of colon carcinoma with lymphatic and hepatic metastases useful for testing of novel molecularly targeted agents. PDTT of primary colon carcinoma, lymphatic and hepatic metastases were used to create xenograft models. Hematoxylin and eosin staining, immunohistochemical staining, genome-wide gene expression analysis, pyrosequencing, qRT-PCR, and western blotting were used to determine the biological stability of the xenografts during serial transplantation compared with the original tumor tissues. Early passages of the PDTT xenograft models of primary colon carcinoma, lymphatic and hepatic metastases revealed a high degree of similarity with the original clinical tumor samples with regard to histology, immunohistochemistry, genes expression, and mutation status as well as mRNA expression. After we have ascertained that these xenografts models retained similar histopathological features and molecular signatures as the original tumors, drug sensitivities of the xenografts to a novel VEGF targeted agent, FP3 was evaluated. In this study, PDTT xenograft models of colon carcinoma with lymphatic and hepatic metastasis have been successfully established. They provide appropriate models for testing of novel molecularly targeted agents.