Objective:To observe the effects of hyperthermia on the sensitivity of gastric cancer cell lines to paclitaxel (TAX) . Methods :To establish TAX-resistant gastric cancer cell line through a method of increasing concertration gradient and named it MKN-45/TAX .Immunocytohistochemistry staining method was used to detect the expression of multi-drug resistance gene (MDR1) in MKN-45/TAX and MKN-45 .CCK-8 test was used to detect the proliferation inhibition rates in two kinds of cell lines under different temperatures and different TAX concentration .Real-time polymerase chain reaction (RT-PCR) and West-ern blotting were used to detect the expression of MDR1 mRNA and P-glycoprotein (P-gp) before and after target siRNA treat-ment .Results:Establishment of MKN-45/TAX cell line was successful .The expression level of MDR1 was high in MKN-45/TAX whereas it was low in MKN-45 .As TAX concentration increased ,the proliferation inhibition rates of both cell lines in-creased .At 42 ℃ the proliferation inhibition rate of MKN-45/TAX to TAX chemotherapy decreased ,while that of MKN-45 was the opposite .Both the expression of MDR1 mRNA and P-gp decreased after the siRNA transfection .Conclusions :Hyper-thermia combined with chemotherapy may enhance the resistance of TAX-resistant gastric cancer cell line to TAX ,while it may enhance the sensitivity of TAX-sensitive gastric cancer cell line to TAX .The mechanism may be related to the expression of MDR1 .

BACKGROUNDTo investigate the role of curative and palliative surgical treatment of lung cancer with video-assisted thoracoscopic surgery (VATS).

METHODSForty-three patients with lung cancer were prescribed operations with VATS, which included 5 cases of stage IA, 14 cases of IB, 1 case of IIA, 4 cases of IIB, 7 cases of IIIA, 6 cases of T4-IIIB and 6 cases of IV. The 7 patients of stage IIIA were previously staged as N0 before operation, but reevaluated as N2-IIIA after operation. There were 3 cases of malignant pleural effusion and 3 cases of pleural implantation in stage IIIB cases. There were 2 cases of cardiac tamponade, 1 case of solitary brain metastasis, and 3 cases of ipsilateral or contralateral solitary lung metastasis in cases of stage IV. The main methods of operation performed included lobectomy in 36 cases, wedge resection in 5 cases, and pericardial opening in 2 cases. Systemly mediastinal lymph node dissections were performed in 36 cases. Concurrent contralateral pulmonary wedge resections were performed in 2 cases of contralateral solitary lung metastasis. Malignant pleural effusions were prescribed resection of implantation nodules, electrocautery and pleurodesis.

RESULTSThere was no perioperative death or bronchial leak. Five cases suffered lung infection, and 2 cases occurred with incision infection. Malignant pleural effusion in the 3 cases was controlled satisfactorily. Two cases of pericardial opening died in 4 months and 8 months after operation respectively. The other patients were alive till present. Postoperative hospital stay was 5-15 days with average of 7.4 days, except of two cases of pericardial opening.

CONCLUSIONSVATS is an alternative way for complete resection of early stage lung cancer. It is technically feasible to dissect mediastinal lymph node for accidental N2 lung cancer. VATS has significant advantage in concurrent bilateral pulmonary resection. The palliative operation of malignant pleural effusion and cardiac tamponade by VATS can markedly improve the quality of life of patients.