目的探讨非功能性甲状旁腺囊肿的临床特点，总结其诊治经验。 方法回顾性分析6例非功能性甲状旁腺囊肿临床资料，结合该病的临床症状、辅助检查、随诊情况，讨论其诊断、治疗与预后。 结果6例患者均行手术治疗，术后病理确诊为非功能性甲状旁腺囊肿，术后均获得随访，随访时间6个月～5年，平均42个月，无复发。 结论非功能性甲状旁腺囊肿术前诊断困难，确诊依靠病理检查，手术切除为主要治疗手段。
Based on transversely isotropic theory, a finite element model for three-dimensional solid-liquid coupling defect repair of articular cartilage was established. By studying stress state of host cartilage near the restoration interface, we identified deformation type of cartilage and discussed the cause of restoration interface cracking. The results showed that the host cartilage surface node near the restoration interface underwent compression deformation in the condition of surface layer defect repair. When the middle layer, deep layer or full-thickness defect were repaired, the node underwent tensile deformation. At this point, the radial dimension of cartilage increased, which might cause restoration interface cracking. If elastic modulus of the tissue engineered cartilage (TEC) was lower (0.1 MPa, 0.3 MPa), the host cartilage surface layer and middle layer mainly underwent tensile deformation. While elastic modulus of TEC was higher (0.6 MPa, 0.9 MPa), each layer of host cartilage underwent compression deformation. Therefore, the elastic modulus of TEC could be increased properly for full-thickness defect repair. This article provides a new idea for evaluating the effect of cartilage tissue engineering repair, and has a certain guiding significance for clinical practice.
A solid-liquid two-phase finite element model of articular cartilage and a microscopic finite element model of chondrocytes were established using the finite element software COMSOL in this study. The purpose of the study is to investigate the mechanics environment and the liquid flow field of the host cartilage chondrocytes in each layer by multi-scale method, under physiological load, with the different elastic modulus of artificial cartilage to repair cartilage defect. The simulation results showed that the uniform elastic modulus of artificial cartilage had different influences on the microenvironment of different layer chondrocytes. With the increase of the elastic modulus of artificial cartilage, the stress of the shallow surface layer and the intermediate layer chondrocytes increased and the stress of deep layer chondrocytes decreased. The flow field direction of the middle layer and the bottom layer of cartilage can also be changed by artificial cartilage implantation, as well as the ways of nourishment supply of the middle layer and underlying chondrocytes change. A barrier to underlying chondrocytes nutrition supply may be caused by this, thus resulting in the uncertainty of the repair results. With cross-scale finite element model simulation analysis of chondrocytes, we can quantitatively evaluate the mechanical environment of chondrocytes in each layer of the host cartilage. It is helpful to assess the clinical effect of cartilage defect reparation more accurately.
Melanin nanoparticles (MNPs) not only retain the inherent characteristics of melanin (metal ion chelation, photothermal conversion property, etc.), but also can exhibit more excellent properties, such as high dispersion stability, good biocompatibility and biodegradability, etc. Furthermore, these performances can be enhanced to target the specific sites and treat diseases by the surface modification or combination with functional substance. In this paper, the characteristics, preparation methods and applications of MNPs were reviewed. It provides a reference for further development of application for MNPs, and theoretical basis for practice in biology, medicine and so on.