The mechanism of miR-23a in regulating myocardial cell apoptosis through targeting FoxO3.

OBJECTIVE: Myocardial cell apoptosis represents important pathologic basis of ischemia-reperfusion injury (I/R). MiR-23a is related to myocardial hypertrophy and cardiac remodeling by regulating myocardial cell growth and apoptosis. This study intended to observe the regulating effect of miR-23a in myocardial cell and related target, and investigate its clinical significance to I/R injury. MATERIALS AND METHODS: The rats were divided into sham group and myocardial I/R group. Myocardial cell cycle and miR-23a expression were tested. H2O2 was applied to treat H9c2 rat myocardial cell to simulate oxidative stress during I/R. The cells were divided into blank group, NC group, miR-23a mimic group, H2O2 group, and miR-23a + H2O2 group. ROS content and cell apoptosis were detected by flow cytometry. MiR-23a, FoxO3a, and BIM gene expression were determined by qRT-PCR. FoxO3a and BIM protein levels were measured by Western blot. RESULTS: Compared with sham group, myocardial apoptosis increased, while miR-23a expression was significantly downregulated in I/R group. H2O2 treatment markedly increased ROS levels in H9c2 cells and elevated apoptosis. The overexpression of mMiR-23a effectively reduced cell apoptosis induced by H2O2 treatment. H2O2 treatment significantly decreased miR-23a expression, while markedly elevated the levels of FoxO3a and BIM. The overexpression of miR-23a apparently impeded the induction of FoxO3a and BIM by H2O2. CONCLUSIONS: The downregulation of miR-23a plays a negative role in oxidative stress and cell apoptosis induced by I/R. The overexpression of miR-23a is of significance to alleviate cell apoptosis through inhibiting FoxO3a and downstream target BIM expression.

Effects of vacuum sealing drainage on the treatment of cranial bone-exposed wounds in rabbits.

This study was designed to assess the efficacy of vacuum sealing drainage (VSD) on skull exposure wounds in rabbits and to investigate the underlying mechanism of the process. Full-thickness excisional circular wounds 2×2 cm with or without periosteum involvement were created in 88 New Zealand white rabbits (mean body weight: 3.0±0.65 kg). Animals were randomly divided into 4 groups: periosteum-intact wounds treated with traditional dressing (p+control), periosteum-intact wounds treated with VSD (p+VSD), periosteum-lacking wounds treated with traditional dressing (p-control) and periosteum-lacking wounds treated with VSD (p-VSD). The wounds treated with traditional dressing were covered with Vaseline gauze, while VSD treatment was accompanied with continuous -120 mmHg pressure. Finally, wound tissues were harvested for analysis of hydroxyproline content and histologic detection. VSD hastened the wound healing process significantly (P<0.05) compared to the corresponding control groups. VSD alleviated the inflammation reaction, accelerated re-epithelialization and facilitated the organization of collagen fibers into neat rows. During the wound healing process, the hydroxyproline content increased overtime [i.e., postoperative days (POD) 7, POD 10 and POD 15] in all four groups, and it peaked in the p+VSD group. VSD also promoted angiogenesis via increasing number and quality of collagen. We concluded that VSD can promote healing in bone-exposed wounds via increasing hydroxyproline content and vessel density, reducing inflammatory responses and generating ordered collagen arrangement.

Does cross-linked polyethylene decrease the revision rate of total hip arthroplasty compared with conventional polyethylene? A meta-analysis.

BACKGROUND: Although cross-linked polyethylene is resistant to wear in comparison to conventional polyethylene, it remains unknown whether it can decrease the wear-related revision rate of total hip arthroplasty. OBJECTIVES: To determine whether cross-linked polyethylene decreases the wear-related revision rate of total hip arthroplasty compared with conventional polyethylene. DATA SOURCES: Electronic databases, including PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials, were queried from inception to July 6, 2013. STUDY SELECTION: Randomized controlled trials (RCTs) comparing cross-linked polyethylene with conventional polyethylene were included. In addition, the standard 28-mm femoral head was used, and follow-up was performed for a minimum of 5 years. The primary outcome assessed was wear-related revision. The secondary outcome measures evaluated were the incidence of osteolysis, the linear wear rate, and the linear head penetration. DATA SYNTHESIS: The Cochrane Collaboration's tool for assessing the risk of bias was used for quality assessment. Data from eligible studies were pooled using a random effects model. RESULTS: Eight studies involving 735 patients were included in this study. Meta-analysis showed there was no significant difference between cross-linked and conventional polyethylene group in terms of osteolysis or wear-related revision. The pooled mean differences were significantly less for the linear wear rate and linear head penetration for cross-linked polyethylene than for conventional polyethylene. LIMITATIONS: The studies differed with respect to the cross-linked liner brands, manufacturing processes, and radiological evaluation methods. Moreover, the follow-up periods of the RCTs were not long enough. CONCLUSIONS: The current limited evidence suggests that cross-linked polyethylene significantly reduced the radiological wear compared with conventional polyethylene at midterm follow-up periods. However, there is no evidence that cross-linked polyethylene had an advantage over conventional polyethylene in terms of reducing osteolysis or wear-related revision. Nevertheless, future long-term RCTs on this topic are needed. KEY FINDINGS: Cross-linked polyethylene significantly reduced radiological wear but not osteolysis or wear-related revision in comparison to conventional polyethylene at midterm follow-up periods. LEVEL OF EVIDENCE: Level I, systematic review of level I studies.