Objective:To investigate the expression of epigenetic inhibitor polycomb group proteins such as enhancer of zeste homolog 1/2 (EZH1/EZH2), embryonic ectoderm development protein (EED) and suppressor of zeste 12 (SUZ12) in common cutaneous T-cell lymphomas and lymphoproliferative disorders (CTCL/LPD) .Methods:Totally, 93 paraffin-embedded skin samples of CTCL/LPD and 8 of lichen planus were collected from Hospital for Skin Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College between 2012 and 2019, and subjected to immunohistochemical staining to determine the protein expression of EZH2, EED, SUZ12 and EZH1. Statistical analysis was carried out with SPSS 25.0 software by using chi-square test and Spearman correlation analysis.Results:The 93 cases of CTCL/LPD included 44 cases of mycosis fungoides (MF), 17 natural killer/T cell lymphoma (NK/TCL), 8 primary cutaneous anaplastic large cell lymphoma (PC-ALCL), 8 lymphomatoid papulosis (LyP), 8 hydroa vacciniforme-like lymphoproliferative disorder (HV-like LPD) and 8 cases of subcutaneous panniculitis-like T cell lymphoma (SPTCL). Among the 93 CTCL/LPD cases, 83 (89.2%) were positive for EZH2, 81 (87.1%) for EED, 78 (83.9%) for SUZ12 and 37 (39.8%) for EZH1; among the 8 cases of lichen planus, 1 was positive for EZH2, all were positive for EZH1, and all were negative for EED and SUZ12. The expression of EZH2, EED, SUZ12 and EZH1 in lichen planus samples significantly differed from all the CTCL/LPD samples ( χ2 = 41.75, 39.74, 39.36, 32.83, respectively, all P < 0.001), and from MF, NK/TCL, PC-ALCL, LyP, HV-like LPD and SPTCL samples separately (α = 0.008 3, all P < 0.001). Meanwhile, the score of EZH2 expression was negatively correlated with that of EZH1 expression in the MF, NK/TCL, PC-ALCL, LyP, HV-like LPD and SPTCL tissues ( rs = -0.60, -0.68, -0.89, -0.74, -0.93, -0.80, respectively, all P < 0.05) . Conclusion:Polycomb group proteins EZH2, EED, SUZ12 and EZH1 are abnormally expressed in CTCL/LPD lesions.

Objective To analyze the influence from material and size of the filling block on stress distributions of the tibial osteotomy model. Methods The filling blocks with three different materials (iliac bone, cancellous bone and polyetheretherketone (PEEK)) and five different sizes were established and implanted to the tibial osteotomy models, respectively. The mechanical loads were applied on the model, the stress distribution and edge displacement of the model were analyzed. Results For three kinds of materials, the stress at proximal end of the tibia and the plate, as well as edge displacement in the model implanted with filling block by iliac bone material were lower than those of the cancellous bone and PEEK, but the filling block by iliac bone material had the highest stress. When the filling blocks with different sizes were implanted in osteotomy space, the stress distribution on each part of the tibial osteotomy and edge displacement were different. Especially when the width of the filling block was reduced from 30 mm to 10 mm, the peak stress of the proximal tibia, steel plate and filling block was increased by 49. 3% , 92. 7% and 54. 4% on average. Conclusions Different filling block parameters will affect the stress distribution in different parts of the tibial osteotomy. The research results provide the theoretical basis for parameter selection of the tibial osteotomy filling block in clinic.