Clinical Orthopaedics

1.磨损颗粒介导的骨溶解--我们已经明确地证实，骨祖细胞是受来自金属骨科植入材料的磨损颗粒的存在极大影响的靶细胞类型之一。颗粒处理的成体干细胞增殖速度减慢，被诱导发生凋亡，并在成骨分化中受到抑制。我们最近的研究表明，钛颗粒对间充质干细胞的作用与其对细胞骨架结构和细胞黏附的破坏以及特定细胞因子的释放有关。 2.骨科感染的分子检测-我们开发了基于聚合酶链式反应(PCR)的技术，用于检测骨科相关组织中的细菌感染，特别是感染性关节炎和假体周围感染。通过靶向RNA，包括mRNA和rRNA，我们能够使用定量逆转录-聚合酶链式反应(qRT-PCR)来检测和评估活菌载量。一个利用滑液的临床系列已经完成，展示了这项技术的潜在临床应用。 3.超生理冲击介导的软骨退变模型--我们建立了一种可重复性的、基于弹簧冲击器的兔关节退变模型，用于研究冲击性关节退变。我们的重点是分析导致骨关节炎样关节软骨退变的早期细胞反应。 4.牵张成骨的动物模型--牵张成骨是一种独特而有效的诱导生后骨生长的方法，其机制尚不清楚。我们开发并完成了一种小鼠模型的研究，利用微阵列技术分析与牵张成骨有关的基因表达事件。此外，我们正在开发一种体外机械激活模型，使用二维和三维条件下的培养细胞来模拟分心 成骨作用。

1. Wear particle mediated osteolysis - We have clearly established that osteoprogenitor cells represent one of the target cell types dramatically affected by the presence of wear debris particles derived from metallic orthopaedic implant materials. Particle treated adult stem cells slow down in their proliferation, are induced to undergo apoptosis, and are inhibited in osteogenic differentiation. Our recent study demonstrated that particle osteolysis and accompanying disruption of cytoskeletal architecture and cell adhesion, as well as the release of specific cytokines, are responsible for the titanium particle effects on mesenchymal stem cells. 2. Molecular detection of orthopaedic infections - We have developed polymerase chain reaction (PCR)-based technologies for the detection of bacterial infection in orthopaedically relevant tissues, specifically septic arthritis and periprosthetic infection. By targeting RNA, both mRNA and rRNA, we are able to use quantitative reverse transcription-PCR (qRT-PCR) to detect as well as assess the viable bacterial load. A clinical series utilizing synovial fluid has been completd demonstrating potential clinical application of the technology. 3. Supraphysiological impact mediated cartilage degeneration model - We have developed a reproducible, spring-loaded impactor based rabbit model to study impact-induced articular degeneration. We are focusing on the analysis of early cellular responses that lead to subsequent osteoarthritis-like articular cartilage degeneration. 4. Animal model of distraction osteogenesis - A unique and effective procedure to induce postnatal bone growth, the mechanism of distraction osteogenesis is not well understood. We have developed and completed a study of a mouse model to analyze by microarray technology the gene expression events accomanying distraction osteogenesis. In addition, we are developing an in vitro mechanical activation model using culture cells in 2-D and 3-D conditions to simulate distraction osteogenesis.