细胞毒素相关蛋白基因A与胃粘膜组织恶变的研究

目的:研究细胞毒素相关蛋白基因A(cagA)阳性幽门螺杆菌(Hp)在胃粘膜组织恶性化转变中的作用。方法:以含Hp细胞毒素相关蛋白基因A的质粒(P~(MC3))为外参照品,在微孔板上对PCR扩增cagA的产物作探针杂交及辣根过氧化物酶酶促显色分析,定量榆测不同组织中cagA阳性Hp。结果:往50份Hp尿素酶B基因阳性的临床标本中检测到28份cagA亦阳性(56％),其中5份浅表性胃炎组织,12份癌前病变组织及11份胃癌组织。浅表性胃炎组织cagA阳性的Hp感染率(31％)及每毫克组织感染的平均拷贝数(12.8)均显著低于(P<0.01或P<0.05)癌前病变组织(60％;77.1)或胃癌组织(79％;57.6),二者在后两种组织间均无显著性差别(P>O.05)。结论:cagA阳性的Hp感染可能有助于胃粘膜组织的恶性化转变,这种转变与cagA阳性Hp的感染量有关。

The Effect of Cytotoxin Associated Gene A of Helicobater Pylori on the Canceration of Gastric Mucosa

To study effects of cytotoxin associated gene A (cagA) positive Helicobacterpylori (Hp) on the canceration of gastric mucosa. Methods: With plasmid PMC3, containing the cagA of Hp, being used as the external standard, one strand of the PCR product of cagA was hybridized with a horseradish peroridase coupled single strand probe in microplate wells for colorimetric and quantitative detection of cagA positive Hp in gastric mucosa. Results: Tweenty-eight of the 50 samples infected with rueB gene positive Hp were also cagA positive (56%). including 5 samples of superficial gastritis, 12 of precancerous lesion and 11 of gastric cancer. The infection rate and mean infection copies (per microgram tissue) of cagA positive Hp in gastritis (31%. 12.8) were significantly lower (P<0.01 or P<0.05) than those of precancerous lesion (60%. 77.1) or those gastric cancer (79%, 57.6) respectively, but it had no significant difference between the later two tissues. Conclusion: The infection of cagA positive Hp may promote the processes for gastric mucosa to become cancerous and that these processes may have much to do with the quatitation of cagA positive Hp infected.