OBJECTIVE:To establish a HPLC method for determining the content of Meropenem and to observe the stability of Meropenem in mixing with 5%GS,GNS and NS.METHODS:The conditions of HPLC were:column,Nova-Pak C18;mobile phase,acetonitrile-0.05mol KH2PO4(4∶96);flow rate,1.0ml/min;detection wavelength,300nm.After Meropenem mixing with 5%GS,GNS and NS,the changes of external apperance were observed in room temperature,the content was detected with HPLC and the pH and insoluble particles were determined.RESULTS:The calibration curve was in good linearity in the range of 12.5～250?g/ml(r=0.9 999)and the recovery was 99.7% with RSD=1.1%.CONCLUSION:This detection method is effective,rapid and accurate.Meropenem is stable in infusion fluids for 4 hr.

Objective To investigate the expression of membrane type 1 matrix metalloproteinase(MT1-MMP) in the esophageal carcinoma tissues and in normal periearcinomatous tissues and its clinical significance. Methods Immunohistochemistry was used to study the expression of MT1-MMP in esophageal carcinoma tissues and normal tissues in distance for 5-7 em from tumor. Results Among 54esophageal carcinoma specimens, the positive expression rate of MT1-MMP was 87.0%, while all of themwere expressed a small quantity in normal esophageal epithelial tissues, the expression in the esophageal carcinoma tissues was significantly higher than those in normal esophageal epithelial tissues (P ＜ 0.01 ).The degree of MT1-MMP expressions was associated with the depth of tumor invasion (P ＜ 0.01 ), the invasion of the lymph nodes(P ＜ 0.01 ) and the relapse and/or metastasis of the tumors for three years after surgery(P ＜0.01 ), and was also related to differentiation of tumor cells (P ＜ 0.01 ). Conclusions The expression of MT1-MMP in the esophageal carcinoma tissues is well associated with the depth of tumor invasion, the invasion of the lymph nodes, the differentiation of tumor cells and relapse and/or metastasis of the tumors for three years after surgery. MT1-MMP plays an important rote in the invasion and metastasis in the patients with esophageal carcinoma.