本试验以布氏肉汤旋转培养法制备幽门螺杆菌(Hp)培养滤液，研究Hp代谢物体外对胃粘膜细胞DNA的损伤作用。结果表明，胃粘膜细胞受Hp培养滤液作用后，双链DNA百分含量，DNA增色效应和DNA-溴化乙锭复合物的荧光强度随作用时间增加而降低，受损DNA对脱氧核糖核酸酶产生明显抗性，提示Hp的代谢物可引起胃粘膜细胞DNA损伤，Hp感染可能是胃癌的重要病因之一。

Objective To investigate the effects of cell-matrix adhesion on drug resistance of tumor cells. Methods MTT test was conducted to study the effects of adhesion between A549-ADR tumor cells and fibronection on sensitivity to anti-cancer drugs, the expression of bcl-2 and Bax gene protein was analyzed by flow cytometry. Results The extent of drug resistance decreased to control levels after the binding was blocked by using anti-β1 integrin antibody. The expression of bcl-2 protein was increased and the Bax protein was decreased when the tumor cell binds to fibronectin, the rate of apoptosis was also significantly decreased when the tumor cell binds to fibronectin and increased after blocked by antiβ-1 integrin antibody. Conclusion Adhesion of tumor cells with fibronectin can increase drug resistance of tumor cells probably by regulating the expression of apoptosis-related genes and the rate of apoptosis.