体外~(14)C-尿素呼气试验检测胃内幽门螺杆菌感染研究

目的　建立诊断胃内幽门螺杆菌感染 (Hp)的体外 1 4 C-尿素呼气试验 (1 4 C- U BT)。方法　 47例 Hp阳性和 32例 Hp阴性患者接受测试 ,用口服微量胃液采集胶囊的办法收集胃液标本于一 10 m l无菌试管内 ,加入生理盐水 0 .5 m l和 18.5 k Bq1 4 C-尿素后立即加橡皮塞密封试管 ,室温放置反应 3h,注射器经橡皮塞注入 2 M H2 SO41.0 ml,使 1 4 CO2 释出。同一注射器回抽气体并立即注入装有 6 .5 ml的 1 4 CO2 搜集闪烁剂液闪瓶内搜集 1 4 CO2 ,最后在液体闪烁计数仪上作 1 4 C放射性测定。结果　 47例 Hp阳性病人 1 4 C放射性几何均数为 5 30 dpm,而 32例 Hp阴性者结果为 2 1dpm,二者相差 2 3倍 (Wilcoxon秩和检验 ,u=5 .5 976 ,P<0 .0 1)。以受试者工作特征曲线分析法得出判别阈值为 75 dpm ,对 Hp诊断的敏感性和特异性为 92 %(4 3/ 47)和 91% (2 9/ 32 )。结论　体外 1 4 C- UBT诊断 Hp感染具有高度的准确性 ,无放射性损伤之虞 ,可适用于临床诊断。

A ~(14)C-UrEATH TEST IN VITRO FOR DETECION OF HELICOBACTER PYLORI

Objective The mini-dose 14 C-urea breath test in vito is one of the most accurate,rapid and cheap noninvasive methods for detecting the presence are still worry about the safety of the test.The purpose of this study is to develop a 14 C-urea breath test in vitro for detection of gastric H.pylori infection.Methods Of 79 strdicd subjects,47 were positive for H.pylori infection and 32 were negative.Gastric juice sample collected by a thread attached cotton capsule was mixde with 18.5kBq of 14 C-urea and 0.5ml of normal salt in a 10ml of sterile glass tube The glass tube was then capped tightly with a rubber and incubated at room temperature for three hours,After adding 1ml of 2M H 2SO 4into the glass tube through injection to release 14 CO 2,gas in the tube was aspirated by syinge and injected into a scintillation vial containing 6.5ml of mixed solution of CO 2 absorbent and scintillation fluid. 14 C radioactivity was counted in a liquid scintillation counter.Results The geometric mean of 14 C radioactivity in 47 subjects positive for H.pylori was 23 times higher than that in 32 subjects for H.pylori(530dpm vs21dpm;Wilcoxon test,u=5.5976,P<0.01).Using receiver operator characteristic analysis,we selected a cut-off value of 75dpm to ceparate those positive and negative for H.pylori.The sensitivity and specificity were 92%(43/47)and 91%(29-32),respectively.Conclusions The 14 C-urea breath test in vitro has a high diagnostic accuracy without radiation exposure.It might be convenient for clinic diagnosis of H.pylori infection.