HIF-1α inhibits IDH-1 expression in osteosarcoma.

Recently, hypoxia inducible factor-1 (HIF-1) was reported to be correlated with isocitrate dehydrogenase 1 (IDH-1) in several types of tumors. However, the expression and significance of HIF-1 and IDH-1 in osteosarcoma is still unknown. In the present study, the expression levels of IDH-1 and HIF-1α in 35 formalin-fixed paraffin-embedded sections from osteosarcoma patients were investigated by immunohistochemistry. The expression levels of IDH-1 and HIF-1α in human osteosarcoma cell lines (MG-63 and 143B) were further detected by western blotting under normal and hypoxic conditions. In addition, HIF-1α was downregulated via lentiviral vector­mediated RNA interference (RNAi) in the MG-63 human osteosarcoma cell line. The results revealed that HIF-1α was negatively correlated with IDH-1 in the osteosarcoma tissues. Both in MG-63 and 143B cell lines, the expression of HIF-1α was increased while IDH-1 was decreased under a hypoxic condition compared to normal conditions. HIF-1α downregulation promoted IDH-1 expression in the MG-63 cell line under either normal or hypoxic conditions. In conclusion, our findings suggest that HIF-1α inhibits IDH-1 in osteosarcoma and consequently increases the incidence of osteosarcoma.

Downregulation of IDH2 exacerbates the malignant progression of osteosarcoma cells via increased NF-κB and MMP-9 activation.

Isocitrate dehydrogenase 2 (IDH2) is a mitochondrial NADP-dependent isocitrate dehydrogenase. It is considered to be a novel tumor suppressor in several types of tumors. However, the role and related mechanism of IDH2 in osteosarcoma remain unknown. The expression and significance of IDH2 were investigated by immunohistochemistry in formalin-fixed paraffin sections from 44 osteosarcoma patients. IDH2 was downregulated via lentiviral vector­mediated RNA interference (RNAi) in the Saos-2 and MG-63 human osteosarcoma cell lines. The effect of IDH2 downregulation on human osteosarcoma was studied in vitro by MTT, flow cytometry and invasion assays. Nuclear factor-κB (NF-κB) and matrix metalloproteinase-9 (MMP-9) assays were also used to study the likely molecular mechanism of IDH2 downregulation on the malignant progression of osteosarcoma cells. The results revealed that the expression of IDH2 was inversely correlated with pathological grade and metastasis in osteosarcoma. IDH2 downregulation promoted a pro-proliferative effect on the Saos-2 and MG-63 osteosarcoma cell lines. IDH2 downregulation accelerated cell cycle progression from S to G2/M phase. The pro-proliferative effect induced by IDH2 downregulation may be ascribed to increased NF-κB activity via IκBα phosphorylation. The invasive activity of osteosarcoma cells was also significantly promoted by IDH2 downregulation and may result from elevated MMP-9 activity. In conclusion, IDH2 downregulation may exacerbate malignant progression via increased NF-κB and MMP-9 activity and may implicate the potential biological importance of IDH2 targeting in osteosarcoma cells. Downregulation of IDH2 exacerbates the malignant progression of osteosarcoma cells via increased NF-κB and MMP-9 activation.

Comparison of conservative and operative treatment for distal radius fracture: a meta-analysis of randomized controlled trials.

BACKGROUND: The authors conducted a meta-analysis to compare the effectiveness and safety of conservative and operative treatment for distal radius fracture. METHODS: PubMed, EMBASE, and the Cochrane Library were searched to identify the relevant studies published up to February of 2015. All randomized controlled trials published to compare the conservative and operative treatment were included in the study. Results were pooled using meta-analysis to compare the efficacy and safety of conservative and operative treatment for distal radius fracture. RESULTS: The databases were derived from seven qualified studies that included a total of 523 patients in which 269 cases adopted conservative treatment while 253 cases adopted operative treatment. Overall, compared with the conservative treatment- treated the distal radius fracture, operative therapies resulted in significantly better radiographic (P<0.05), however, no significant differences of the functional outcomes and complication rate were observed between the two methods (P>0.05). CONCLUSION: Surgical treatment seems to be more effective distal radius fracture compared with conservative treatment when the radiographic outcomes were analyzed, and no significant differences were deteched in the functional outcomes and complication rate.

Analysis of blood flow and local expression of angiogenesis­associated growth factors in infected wounds treated with negative pressure wound therapy.

Angiogenesis is involved in the wound healing process. Increased angiogenesis and blood flow constitute a major mechanism of negative pressure wound therapy (NPWT), which has been shown to facilitate the healing of infected wounds. However, the effect on the expression of angiogensis­related growth factor remains unknown. The goal of the current study was to investigate the angiogenic factor levels prior to and following NPWT in infected wounds. A total of 20 patients with infected wounds treated with NPWT were included in the study. Patients acted as their own control; the postoperative measurements of patients were considered as the experimental group, while preoperative measurements were considered as the controlled group. Blood flow was recorded prior to and during NPWT. A total of 10 angiogensis­related growth factors were detected using a protein biochip array to analyze the change in protein levels prior to NPWT, and on the third day during NPWT. All wounds were successfully reconstructed by skin grafting or using local flaps following NPWT. NPWT resulted in significantly increased blood flow in the wound. There was a significant increase in vascular endothelial growth factor (VEGF), EGF, platelet­derived growth factor and angiotesin­2 following NPWT, while basic fibroblast growth factor decreased significantly. NPWT affects the local expression of angiogenesis­associated growth factors, which represents another mechanism to explain how NPWT accelerates wound healing.

Combination of negative pressure wound therapy with open bone grafting for bone and soft tissue defects.

The aim of this study was to investigate the efficiency of negative pressure wound therapy (NPWT) combined with open bone graft (OBG; NPWT-OBG) for the treatment of bone and soft tissue defects with polluted wounds in an animal model. All rabbits with bone and soft tissue defects and polluted wounds were randomly divided into two groups, the experimental group (NPWT with bone graft) and the control group (OBG). The efficacy of the treatment was assessed by the wound conditions and healing time. Bacterial bioburdens and bony calluses were evaluated by bacteria counting and X-rays, respectively. Furthermore, granulation tissue samples from the wounds on days 0, 3, 7 and 14 of healing were evaluated for blood vessels and vascular endothelial growth factor (VEGF) levels. Wounds in the experimental group tended to have a shorter healing time, healthier wound conditions, lower bacterial bioburden, improvement of the bony calluses and an increased blood supply compared with those in the control group. With NPWT, wound infection was effectively controlled. For wounds with osseous and soft tissue defects, NPWT combined with bone grafting was demonstrated to be more effective than an OBG.

Absorbable implants versus metal implants for the treatment of ankle fractures: A meta-analysis.

This meta-analysis was performed to evaluate the efficiency and the safety of absorbable implants. Five major electronic databases (PubMed, Embase, Cochrane Library, SinoMed and Wanfang Data) were systematically searched for randomized controlled trials (RCTs) from their establishment to November 2012. Studies on absorbable implants and metal implants for ankle fractures were selected. The meta-analysis was performed using RevMan 5.1. Ten studies with 762 patients were included and analyzed. Compared with metal implants, absorbable implants used for the internal fixation of ankle fractures produce similar radiographic and functional outcomes (P= 0.52). Normally, removal of the internal fixation is unnecessary (P<0.0001) and the incidence of palpable implants is lower (P=0.02) for absorbable implants. No statistically significant difference was observed between the two groups with regard to foreign body reactions (P=0.07), infection (P= 0.69), osteoarthritis (P= 0.39), pain (P= 0.06), refracture (P=0.67), skin necrosis (P=0.99), deep vein thrombosis (P=0.21) and nerve injury (P=0.94). Absorbable implants used in ankle fractures rarely require reoperation and result in similar functional outcomes and complications compared with metal implants. These characteristics make them efficient and reasonably safe for the treatment of ankle fractures.

Bioconjugated quantum dots as fluorescent probes for biomedical imaging.

Luminescent semiconductor quantum dots have become an important class of fluorescent labels for biological and biomedical imaging. In comparison with conventional organic dyes and fluorescent proteins, quantum dots have extraordinary fluorescent properties including high brightness, high resistance to photobleaching and tunable wavelengths. In this review, we briefly discuss the properties and modification of quantum dots. We focus on the applications of quantum dots in biomedical imaging, including molecular detection, live cell imaging and in vivo imaging. The toxicity of the quantum dots to cells and animals is also discussed.