Objective To study the effect of metformin on the growth of megakaryocytic leukemia cell line Dami and to explore the molecular mechanisms of the inhibitory effect of metformin on the proliferation of Dami. Methods The Dami cells were cultured and divided into control and 1,2,4,8,16 and 32 mmol·L-1 metformin groups.Then MTT test was performed to detect the inhitory rate of proliferation of Dami cells after treated with different concentrations of metformin. Flow cytometry was used to examine the distribution of cell cycle, and Western blotting was carried out to analyze the expressions of Cdc2 and CylinB1 and the phosphorylation of Cdc2. Results The MTT results showed that compared with control group,the inhibitory rates of proliferation of the Dami cells in 32 mmol·L-1 metformin groups at 0,24,48,72 and 96 h (35.1%±2.3%,49.7%±5.1%, 78.85±0.9%,79.1%± 3.0%%,and 85.2%± 3.2%)were significantly increased(P<0.01),Furthermore, after metformin treatment for 72 h,the inhibitory rates of proliferation of the Dami cells in 1,2,4,8,16 and 32 mmol·L-1 metformin groups were (33.8 ± 0.3)%,(51.9 ± 0.2)%,(59.4 ± 1.6)%,(65.5 ± 2.0)%, (75.5±0.9)%,and (79.1±3.0)%,respectively. Metformin inhibited the growth of Dami cells in a time-and dose-dependent manner. The flow cytometry results results revealed that compared with control group, the percentages of Dami cells in G2/M phase in 1,2 and 4 mmol·L-1 metformin groups were increased from (26.0± 0.5)% to (38.5 ± 1.5 )%, (48.4 ± 1.1 )%, and (58.2 ± 2.7 )%;there was significant difference in the percentages of Dami cells in G2/M phase between control group and 4 mmol·L-1 metformin group (P<0.01). Western blotting analysis showed that compared with control group, the expressions of Cdc2 and CyclinB were evidently reduced, the phosophorylation of Cdc2 at Tyr1 5 was up-regulated, and the phosphorylation at Thr1 6 1 was down-regulated.Conclusion Metformin can inhibit the growth of Dami cells and induce G2/M arrest,and its mechanism may be related to inhibiting the activation of Cdc2/CyclinB1 complex.

Objective To investigate the feasibility and safty of indocyanine green (ICG) fluorescence staining by laparoscopic ultrasound and three-dimensional (3D) visualization guided portal branch puncture approach in anatomical segmentectomy.Methods The retrospective cross-sectional study was conducted.The clinical data of 26 patients who underwent anatomical segmentectomy using ICG fluorescence staining by laparoscopic ultrasound and 3D visualization guided portal branch puncture approach in the Zhongshan Hospital of Fudan University between December 2016 and April 2018 were collected.The preoperative 3D visualization reconstruction and areas of portal branch perfusion were analyzed,laparoscopic ultrasound localization was intraoperatively applied to tumor and portal vein of targeted hepatic segment,and then portal branch puncture and staining were done under laparoscopic ultrasound and 3D visualization,finally laparoscopic anatomical segmentectomy was performed.Observation indicators:(1) intraoperative situations:success rate of portal vein puncture,targeted hepatic segment,effect of ICG fluorescence staining,intraoperative complications,operation time,volume of intraoperative blood loss,blood transfusion,conversion to open surgery,tumor diameter,the minimum resection margin to tumor;(2) postoperative situations:postoperative complications (Clavien-Dindo classification as a criteria) and duration of hospital stay;(3) follow-up situations:cases with follow-up,follow-up time and postoperative tumor recurrence.Follow-up using outpatient examination and telephone interview was performed to detect postoperative tumor recurrence up to April 2018.Measurement data with normal distribution and count data were respectively described as average (range) and percentage.Results (1) Intraoperative situations:a success rate of laparoscopic ultrasound and 3D visualization guided portal branch puncture in 26 patients was 100.0％ (26/26),and punctures in S8,S7,S2,S3,S6,S5 and S4 of the liver were respectively performed to 7,6,4,3,3,2 and 1 patients.Of 26 patients,22 achieved expected effect of ICG fluorescence staining,with a statisfaction of 84.6％ (22/26) and 4 failed to get expected effect,including 2 with uneven dying,1 with staining-uncovered partial areas of targeted liver segment and 1 with adjacent hepatic segmental staining induced to unclear boundary.All the 26 patients were not complicated with ICG injection induced to allergy.Average operation time and volume of intraoperative blood loss were 184 minutes (range,60-315 minutes) and 97 mL (range,10-400 mL),without intraoperative blood transfusion and conversion to open surgery.Average tumor diameter and average minimum resection margin to tumor in 26 patients were respectively 3.2 cm (range,1.2-10.0 cm) and 1.5 cm (range,0.4-3.0 cm).(2) Postoperative situations:of 26 patients,2 with grade Ⅰ-Ⅱ of Clavien-Dindo classification were improved by drug treatments (1 with deep venous thrombosis of the lower extremities and 1 with pleural effusion),no patient had grade Ⅲ and above complications,and there was no bile leakage,infection and hepatic dysfunction.Average duration of hospital stay in 26 patients was 6.9 days (range,5.0-14.0 days).(3) Follow-up situations:26 patients were followed up for 0.3-17.0 months,with a median time of 6.0 months.During the follow-up,1 patient with hepatocellular carcinoma had adrenal metastasis and 25 had tumor-free survival.Conclusion Laparoscopic anatomical segmentectomy with ICG fluorescence staining by laparoscopic ultrasound and 3D visualization guided portal branch puncture approaeh is safe and feasible,especially suitable in posterosuperior liver segments.