Osteoporosis is a metabolic disease characterized by decreased bone mineral density and the destruction of bone microstructure, which can lead to increased bone fragility and risk of fracture. In recent years, with the deepening of the research on the pathological mechanism of osteoporosis, the research on epigenetics has made significant progress. Epigenetics refers to changes in gene expression levels that are not caused by changes in gene sequences, mainly including DNA methylation, histone modification, and non-coding RNAs (lncRNA, microRNA, and circRNA). Epigenetics play mainly a post-transcriptional regulatory role and have important functions in the biological signal regulatory network. Studies have shown that epigenetic mechanisms are closely related to osteogenic differentiation, osteogenesis, bone remodeling and other bone metabolism-related processes. Abnormal epigenetic regulation can lead to a series of bone metabolism-related diseases, such as osteoporosis. Considering the important role of epigenetic mechanisms in the regulation of bone metabolism, we mainly review the research progress on epigenetic mechanisms (DNA methylation, histone modification, and non-coding RNAs) in the osteogenic differentiation and the pathogenesis of osteoporosis to provide a new direction for the treatment of bone metabolism-related diseases.

Ras and Rab interactor 1 (RIN1) is an effector of H-Ras, which plays an important role in the development and progression of carcinomas, but it has not been reported in bladder cancer. Hence, the association of RIN1 expression with prognosis of bladder urothelial carcinoma (UC) was examined. RIN1 mRNA and protein expression in 20 paired UCs and the adjacent normal tissues was detected by quantitative reverse transcription polymerase chain reaction and Western blot. The expression of RIN1 protein in 96 specimens of UCs and 22 specimens of adjacent normal bladder tissues were analyzed by immunohistochemistry. The overall survival (OS) was assessed by univariate and multivariate analysis. Moreover, the progression-free survival (PFS) and recurrence-free survival (RFS), classified by the clinicopathologic features with RIN1 expression, were assessed by multivariate analysis. RIN1 mRNA and protein level was higher in UCs than in the adjacent normal tissues (P < 0.01). Enhanced RIN1 immunoexpression was associated with high histologic grades (P = 0.046), cancer progression (P = 0.047) as well as Ki-67 expression (P = 0.023). Furthermore, the 5-year survival rate was 29% in the subgroup with high level of RIN1 expression, while it was 43% in the subgroup with normal level of RIN1 expression (P < 0.05). Importantly, RIN1 level was revealed as the significant independent prognostic factor for death (P = 0.023) and progression (P = 0.003), but a weak contribution for recurrence (P = 0.063). Collectively, RIN1 expression could be a potential prognostic predictor for UC patients.

We designed this retrospective study with aims to investigate the incidence and risk factors associated with surgical site infection (SSI) following posterior lumbar interbody fusion (PLIF) and instrumentation in patients with lumbar degenerative disease. Eligible patients treated between January 2016 and June 2019 were included. Electronic medical records were inquired for data extraction and collection. Patients with SSI and without SSI were compared using the univariate analyses, and the association between variables and risk of SSI was investigated using multivariate logistics regression analyses. Among 1269 patients, 43 were found to have SSI, indicating a rate of 3.4%. Microbiological culture tests showed 88.4% patients had a positive result. Four SSIs were caused by mixed bacterial, and the remaining 34 by single bacteria. Multiple drug‐resistant strains were detected in 25 (65.8%) SSIs, with meticillin‐resistant coagulase‐negative staphylococcus (MRCNS) predominating (12, 48.0%). ASA III and above (odd ratio (OR), 1.67; 95% confidence interval (CI), 1.11 to 3.07), preoperative stay (OR, 1.13; 95% CI, 1.04 to 1.23), heart disease (OR, 2.88; 95% CI, 1.24 to 6.71), diabetes mellitus (OR, 3.28; 95% CI, 1.66 to 6.47) and renal insufficiency (OR, 4.23; 95% CI, 1.26 to 10.21), prolonged prophylactic antibiotics use (OR, 4.43; 95% CI, 2.30 to 8.54), and the reduced lymphocyte count (OR, 2.11; 95% CI, 1.03 to 4.33) were identified as independent risk factors associated with SSI. These factors, although most not modifiable, should be kept in mind, optimised for surgical conditions, or readily adjusted in the future postoperative management of antibiotics, to reduce postoperative SSIs.