Objective To evaluate the use of three-dimensional reconstruction (3D) to improve the success rate in the first attempt of radiofrequency ablation (RFA) for small hepatocellular carcinoma (HCC).Methods A retrospective study was conducted on 109 patients with small HCC (with single nodule from 3 to 5 cm in diameter) treated with radiofrequency ablation between June 2010 and June 2013.A safe ablation margin was evaluated before and after radiofrequency ablation.The patients were divided into two groups: the 3D-RFA group (49 patients were evaluated by three-dimensional reconstruction before RFA treatment) and the 2D-RFA group (60 patients were not evaluated by three-dimensional reconstruction before RFA treatment).The success rate of the first attempt of radiofrequency ablation, recurrence free survival, overall survival and complications were compared between the two groups.Results The success rate of first ablation reached 95.9％ (47/49) in the 3D-RFA group which was significantly higher than the 48.3％ (29/60) in the 2D-RFA group (P ＜ 0.05).The local tumor progression rate was 8.1％ in the 3D-RFA group versus 23.3％ in the 2D-RFA group (P ＜0.05).The 1-, 2-, 3-year recurrence free survival rates were 85.4％, 63.9％, and 49.8％ respectively in the 3D-RFA group and 72.4％, 43％, and 34.4％ respectively in the 2D-RFA group (P ＜ 0.05).The 1-, 2-, 3-year overall survival rates were 91.4％,78.4％, and 60.9％ respectively in the 3D-RFA group and 83.3％, 58.7％, and 40.9％ respectively in the 2D-RFA group (P ＜0.05).Complications occurred significantly less in the 3D-RFA group (4％, 2/49) than the 2D-RFA group (13.3％, 8/60;P ＜ 0.05).Conclusion Three-dimensional reconstruction improved the success rate of the first attempt of radiofrequency ablation and the prognosis of patients, and with less complications for small hepatocellular carcinoma.

Objective To explore the potential impact of low concentration of metformin on the morphology and function of mitochondria of HepG2 cells. Methods HepG2 cells in experimental group and control group were treated with or without low concentration of metformin (1mM/L), respectively. The cells were incubated for 12h in the incubator with constant temperature and humidity as well as 1% oxygen. Orange Mitoview was used to stain the mitochondria to detect the effects of the drug on its morphology and quantity. Transmission electron microscope was utilized to observe the effect of metformin on the ultrastructure of mitochondria. The mitochondrial respiratory chain complex I activity in HepG2 cell was detected by Complex I Enzyme Activity Dipstick Assay Kit (DAK). Results Orange Mitoview staining showed that low concentration of metformin had little effect on the morphology and number of mitochondria of cells in experimental group , and the difference between control and experimental group was not statistically significant (P > 0.05). In addition, the result was further determined by transmission electron microscopy. However, DAK analysis showed that complex I activity of cells in experimental group was significantly lower than that in control group. Conclusion Under Hypoxia conditions, low concentration of metformin had no significant effect on the morphology and number of mitochondria of HepG2 cells, but it significantly reduces the activity of mitochondria of HepG2 cells.