【Abstract】Objective To investigate the change of vascular endothelial growth factor (VEGF) expression in HepG2 cells under hypoxia. Methods HepG2 cells were cultured under hypoxia（hypoxia group） and normal condition (control group). VEGF expression of HepG2 cells was examined by immunohistochemical staining. The growth of HepG2 cells was examined by MTT colorimetry and cell count. VEGF level in the culture medium was measured by ELISA.Results After 48 h and 72 h of culture, the growth rate of HepG2 cells in hypoxia group was lower than that in control group (P＜0.05). The cell count in hypoxia group (2.51×104/μl and 2.69×104/μl, respectively) was much lower than that in control group(3.01×104/μl and 3.52×104/μl) after 48h and 72h of culture (P＜0.05). In hypoxia group, VEGF level in the culture medium after 24 h and 48 h was higher than that in control group (P＜0.05, P＜0.01). Conclusion Hypoxia may enhance the VEGF expression in HepG2 cells and this could be the reason of high expression of VEGF after transcatheterized hepatic arterial chemoembolization.
Objective To assess the applied significance of carbon nanoparticles in central compartment lymph node dissection in treatment of cN0 papillary thyroid carcinoma. Methods Sixty-eight patients with cN0 papillary thyroid carcinoma who were treated in Tongji Hospital of Tongji Medical College from May. to Oct. in 2012 were randomly allocated to the control group （n=32） and the carbon nanoparticles trace group （tracer group， n=36）， receiving non-carbon nanoparticles trace and carbon nanoparticles trace respectively. All patients were received total resection of thyroid plus the affected side and （or） contralateral side central compartment lymph node dissection. The lymph node-related indexes（including number of dissected lymph node at Ⅵarea and lymph node metastasis rate at Ⅵarea） and operative indexs （including operation time， blood loss， drainage time， complication， and hospital stay） were collected and compared between the 2 groups. Results There were 205 and 324 dissected lymph node at central compartment in control group and tracer group respectively. The results of postoperative pathology showed that the number of lymph node in central compartment of the tracer group was much more than those of control group （8.99±2.24 vs. 6.41±1.56， P＜0.001）. The metastasis rate of central compartment lymph node were 40.6% （13/32） in control group and 47.2% （17/36） in tracer group， but there was no significant difference between the 2 groups （P=0.762）. But in medial area of laryngeal recurrent nerve， the metastasis rate in the tracer group （38.9%， 14/36） was much higher than those of control group （12.5%， 4/32）， P=0.029. There were no significant differences in the operation time， blood loss， drainage time， hospital stay， and complication incidence such as bleeding， temporary hypocalcemia， and injury of superior laryngeal nerve between 2 groups （P＞0.05）. All the patients in 2 groups had followed-up for 6 months without death， recurrence， and metastasis.Conclusions The lymphatic tracer technique of carbon nanoparticles may improve the number of dissected lymph nodes in central region of cN0 papillary thyroid carcinoma， without increasing （or prolonging） operation time， intraoperative blood loss， and postoperative hospital stay， and can accurately represent the metastasis of lymph node， thus to make the staging of the tumor accurately and guide postoperative treatment.