Qianwen Zeng

Increasing evidence suggests that an exogenous electromagnetic field might be involved in many biologic processes which are of great importance for therapeutic interventions. Pulsed electromagnetic fields (PEMFs) are known to be a noninvasive, safe and effective therapy agent without apparent side effects. Numerous studies have shown that PEMFs possess the potential to become a stand-alone or adjunctive treatment modality for treating musculoskeletal disorders. However, several issues remain unresolved. Prior to their widely clinical application, further researches from well-designed, high-quality studies are still required to standardize the treatment parameters and derive the optimal protocol for health-care decision making. In this review, we aim to provide current evidence on the mechanism of action, clinical applications, and controversies of PEMFs in musculoskeletal disorders.

The tumor microenvironment is distinctive in primary and secondary liver cancer. B cells represent an important component of immune infiltrates. Here, we demonstrated that B cells are an important regulator in hepatocellular carcinoma (HCC) and colorectal cancer liver metastasis (CRLM) microenvironments. B cells displayed distinct developmental trajectories in HCC and CRLM. Single-cell analysis revealed that IgG+ plasma cells preferentially accumulated in HCC, whereas IgA+ plasma cells were preferentially enriched in CRLM. Mechanistically, IgG+ plasma cells in HCC were recruited by tumor-associated macrophages via the CXCR3-CXCL10 axis, whereas IgA+ plasma cells in CRLM were recruited by metastatic tumor cells via CCR10-CCL28 signaling. Functionally, IgG+ plasma cells preferentially promoted protumorigenic macrophages formation in HCC, and IgA+ plasma cells preferentially induced granulocytic myeloid-derived suppressor cells activation in CRLM. Clinically, increased infiltration of IgG+ plasma cells and macrophages in HCC was correlated to worse survival, whereas increased intratumoral IgA+ plasma cells and neutrophils in CRLM indicated poor prognosis. Taken together, this study demonstrated plasma and myeloid cell-mediated immunosuppression in HCC and CRLM, suggesting that selectively modulating primary or secondary tumor-related immunosuppressive regulatory networks might reprogram the microenvironment and provide an immunotherapeutic strategy for treating liver cancer. SIGNIFICANCE: The immunomodulatory patterns of tumor-infiltrating B cells are distinct in primary and secondary liver cancer, with plasma cells mediating important physiologic processes that drive cancer progression.

Background: The reverse shoulder arthroplasty (RSA) may be a promising alternative for proximal humerus tumours because of good postoperative shoulder function. However, the conventional reverse shoulder prosthesis can not meet individual needs and RSA has been associated with a relatively high complication rate. Therefore, implant design and surgical reconstruction technique warrant further study. Methods: Between September 2015 and May 2018, 7 patients were treated via RSA after en-bloc resection of the proximal humerus tumours. A 3D-printed guiding baseplate was used to assist the implant of the 3D-printed glenoid prosthesis; a personalized humerus prosthesis was used to reconstruct the proximal humerus. The functional outcomes were assessed by range of motion (ROM) of the shoulder joint, Musculoskeletal Tumour Society (MSTS) functional score, and Toronto Extremity Salvage Score (TESS). We also analyzed tumour recurrence, metastases, and complications associated with the reconstruction procedure. Results: All patients were observed for 14 to 36 months, with an average of 23.6 months. At the final follow-up, the mean MSTS score was 85.7% (range, 73.3–93.3%), and the mean TESS score was 90.0% (range, 84.1–95.9%). No instability, infection, scapular notching, loosening or fracture were observed in this series. One patient with GCT suffered from pulmonary metastasis, while one with osteosarcoma died because of pulmonary metastasis. Conclusion: The 3D-printed guiding baseplate facilitated the accurate implantation of the glenoid prosthesis. The RSA based on a 3D-printed glenoid prosthesis and a personalized custom-made humerus prosthesis significantly improved the shoulder function and decreased the complication rate. Further studies of a larger scale with longer follow-up are required to validate this technology. Keywords: 3D printing technology, tumour, proximal humerus, reverse shoulder arthroplasty, reconstruction