[Objective]To analyze the causes of anterior knee pain after intramedullary(IM) nailing treatment of tibial shaft fractures.[Method]A total of 256 patients with tibial shaft fractures were treated with intramedullary nailing from 2000 to 2007 in our hospital.There were 183 males and 73 females with a mean age of 45 years.All patients were followed up at least once after fracture healing.[Result]Among 256 patients,166 experienced anterior knee pain,accounting for 65%.Ninety-six(58%) treated with transtendinous nailing complained of and 70(42%) treated with paratendinous nailing complained of anterior knee pain.It was worsened after activity but relieved only in 33(20%) by resting or taking analgesic drugs.The anterior knee pain disappeared one year after the IM nailing was taken out.[Conclusion]Anterior knee pain can not be reduced by different approaches of operation for tibial shaft fractures.However,the removal of intramedullary nailing and the muscle exercises around the knee joint can reduce the occurrence of anterior knee pain.

Interferon-γ (IFN-γ), a key effector molecule in anti-tumor immune response, has been well documented to correlate with the intratumoral infiltration of immune cells. Of interest, however, a high level of IFN-γ has been reported in salivary adenoid cystic carcinoma (SACC), which is actually a type of immunologically cold cancer with few infiltrated immune cells. Investigating the functional significance of IFN-γ in SACC would help to explain such a paradoxical phenomenon. In the present study, we revealed that, compared to oral squamous cell carcinoma cells (a type of immunologically hot cancer), SACC cells were less sensitive to the growth-inhibition effect of IFN-γ. Moreover, the migration and invasion abilities of SACC cells were obviously enhanced upon IFN-γ treatment. In addition, our results revealed that exposure to IFN-γ significantly up-regulated the level of programmed death ligand 1 (PD-L1) on SACC cell-derived small extracellular vesicles (sEVs), which subsequently induced the apoptosis of CD8⁺ T cells through antagonizing PD-1. Importantly, it was also found that SACC patients with higher levels of plasma IFN-γ also had higher levels of circulating sEVs that carried PD-L1 on their surface. Our study unveils a mechanism that IFN-γ induces immunosuppression in SACC via sEV PD-L1, which would account for the scarce immune cell infiltration and insensitivity to immunotherapy.
B7-H1 Antigen/metabolism* ; CD8-Positive T-Lymphocytes/pathology* ; Carcinoma, Adenoid Cystic/pathology* ; Carcinoma, Squamous Cell/pathology* ; Cell Line, Tumor ; Humans ; Immunosuppression Therapy ; Interferon-gamma/pharmacology* ; Mouth Neoplasms/metabolism* ; Programmed Cell Death 1 Receptor/metabolism* ; Salivary Gland Neoplasms/pathology*

An in vitro blood-brain barrier (BBB) model is critical for enabling rapid screening of the BBB permeability of the drugs targeting on the central nervous system. Though many models have been developed, their reproducibility and renewability remain a challenge. Furthermore, drug transport data from many of the models do not correlate well with the data for in vivo BBB drug transport. Induced-pluripotent stem cell (iPSC) technology provides reproducible cell resources for in vitro BBB modeling. Here, we generated a human in vitro BBB model by differentiating the human iPSC (hiPSC) line GM25256 into brain endothelial-type cells. The model displayed BBB characteristics including tight junction proteins (ZO-1, claudin-5, and occludin) and endothelial markers (von Willebrand factor and Ulex), as well as high trans-endothelial electrical resistance (TEER) (1560 Ω.cm ± 230 Ω.cm) and γ-GTPase activity. Co-culture with primary rat astrocytes significantly increased the TEER of the model (2970 Ω.cm to 4185 Ω.cm). RNAseq analysis confirmed the expression of key BBB-related genes in the hiPSC-derived endothelial cells in comparison with primary human brain microvascular endothelial cells, including P-glycoprotein (Pgp) and breast cancer resistant protein (BCRP). Drug transport assays for nine CNS compounds showed that the permeability of non-Pgp/BCRP and Pgp/BCRP substrates across the model was strongly correlated with rodent in situ brain perfusion data for these compounds (R = 0.982 and R = 0.9973, respectively), demonstrating the functionality of the drug transporters in the model. Thus, this model may be used to rapidly screen CNS compounds, to predict the in vivo BBB permeability of these compounds and to study the biology of the BBB.