Kodama K, Fujioka T, Ito A, Kodama R, Nasu M
Second Department of Internal Medicine, Oita Medical University, Japan.
J Gastroenterol. 1998;33 Suppl 10:14-7.
Inflammatory cells in the gastric epithelium and direct cell damage are important effects of H. pylori infection in causing gastroduodenal diseases. The aim of this study was to determine whether H. Pylori possessing the cagA gene and vacuolating cytotoxin activity (cagA+/tox+) has these toxigenicities. The detection of cagA was performed by the polymerase chain reaction method. Culture supernatants of H. pylori were tested on rabbit gastric epithelial cell culture for intracellular vacuolation. H. pylori isolates were divided into two major types, cagA+/tox+ and cagA-/tox- strains. Ten Japanese monkeys were allocated to two groups, with six animals inoculated with the cagA+/tox+ strain and four animals inoculated with the cagA-/tox- strain. Five other Japanese monkeys served as controls. They were observed endoscopically every week and the severity of gastritis was evaluated in biopsy specimens obtained from the antral mucosa. Histopathological examination of the gastric mucosa revealed a more severe neutrophil infiltration caused by the cagA+/tox+ strain than that caused by the cagA-/tox- strain for 3 months after inoculation. These findings indicate that cagA and vacuolating cytotoxin may be important factors in causing the severe damage of the human gastric mucosa produced by H. pylori.
胃上皮中的炎性细胞和直接的细胞损伤是幽门螺杆菌感染导致胃十二指肠疾病的重要影响因素。本研究的目的是确定具有细胞毒素相关基因A（cagA）和空泡毒素活性（cagA+/tox+）的幽门螺杆菌是否具有这些致病毒性。采用聚合酶链反应法检测cagA。在兔胃上皮细胞培养物上检测幽门螺杆菌的培养上清液是否导致细胞内空泡形成。幽门螺杆菌分离株分为两种主要类型，即cagA+/tox+菌株和cagA−/tox−菌株。将10只日本猕猴分为两组，6只接种cagA+/tox+菌株，4只接种cagA−/tox−菌株。另外5只日本猕猴作为对照。每周对它们进行内镜观察，并对取自胃窦黏膜的活检标本的胃炎严重程度进行评估。胃黏膜的组织病理学检查显示，接种后3个月，cagA+/tox+菌株引起的中性粒细胞浸润比cagA−/tox−菌株引起的更严重。这些发现表明，cagA和空泡毒素可能是幽门螺杆菌导致人类胃黏膜严重损伤的重要因素。
