肿瘤坏死因子-β基因多态性与胃癌和十二指肠溃疡

目的研究胃癌和十二指肠溃疡患者中的肿瘤坏死因子（TNF）-β基因多态性，并分析TNF-β基因多态性与幽门螺杆菌（H.pylori）感染相互作用与胃癌和十二指肠溃疡的关系。方法采用PCR-RFLP方法对124例胃癌、83例十二指肠溃疡及96例健康对照者进行基因多态性分析。用ELISA方法检测血清Hp抗体。结果胃癌组TNF-β＋252＊G基因频率明显低于对照组（51．2％对63．0％，P＜0．05），TNF-β＋252＊A基因频率明显高于对照组（48．8％对37．0％，P＜0．05），TNF-β＋252A／A基因型的优势比值为2．44（95％CI 1．18—5．03）。在血清H．pylori抗体阳性的胃癌组中，这种基因多态性的影响表现得更明显，优势比值为2．52。十二指肠溃疡和对照组基因频率比较差异无统计学意义（P＞0．05），十二指肠溃疡组的血清H.pylori抗体阳性率明显高于健康对照组（P＜0．01）。结论中国汉族胃癌病人与TNF-β基因多态性相关联，TNF-β＋252A／A基因型与胃癌的易感性有关；十二指肠溃疡病人与TNF-β基因多态性无关联。H．pylori感染是十二指肠溃疡的独立危险因素。     

广东地区幽门螺杆菌cagA基因与细菌定植及其致病性关系的研究

目的：分析广东地区细胞毒素相关基因（cagA）在幽门螺杆菌（H.pylori)中的分布情况及其与患者性别、年龄的关系；探讨H.pylori cagA在不同胃肠疾病发生中的作用及其与胃粘膜慢性炎症程度及H.pylori定植密度的关系。方法：采用改良Skirrow培养基分离培养得到191株H.pylori，用特定引物对各株细菌的cagA 3′端行聚合酶链反应（PCR）扩增鉴定；对其中83例患者再各取胃窦粘膜2块，经HE及Giemsa染色后观察胃粘膜慢性炎症程度及H.pylori定植密度。结果：广东地区H.pylori cagA阳性者占85.3%(163/191)；H.pylori cagA阳性率与患者的性别、年龄无关；消化性溃疡及胃癌患者的H.pylori cagA阳性率显著高于慢性胃炎患者；cagA阳性H.pylori菌株在胃粘膜表面的定植密度较cagA阴性菌株更高，引起的胃粘膜慢性炎症也更为严重；H.pylori的定植密度与其引起的慢性炎症程度呈正相关。结论：广东地区cagA阳性H.pylori感染者占绝大多数；cagA阳性菌株较cagA阴性菌株具有更强的致病力，可能引起更为严重的胃肠道损害。     

上海地区幽门螺杆菌cagA基因3’区和vacA基因的多态性分析及其临床意义

探讨上海地区人群中幽门螺杆菌（H．pylori）cagA基因3’区和vacA基因的多态性及其临床意义。方法：99株H．pylori菌株分离自17例慢性浅表性胃炎（CSG）、21例慢性萎缩性胃炎（CAG）、19例胃溃疡（GU）、23例十二指肠溃疡（DU）和19例胃癌（GC）患者。用聚合酶链反应（PCR）技术对H．pylori菌株的cagA基因3’区和vacA基因信号序列及中间区等位基因进行扩增和检测。结果：99株H．pylori菌株中84株（84．8％）cagA基因阳性,其3’区产物大小均约650bp,属A型。vacA基因信号序列仅检出sla型,见于从94．1％（16／17）的CSG、952％（20／21）的CAG、89．5％（17／19）的GU、87．00（20／23）的DU和89．5％（17／19）的GC患者中分离的菌株（P＝0．87）;中间区等位基因仅检出m2型,见于从70．6％（12／17）的CSG、71．4％（15／21）的CAG、63．20（12／19）的GU、73．9％（17／23）的DU和57．9％（11／19）的GC患者中分局的菌株（P＝0．72）。结论：上海地区人群中H．pylori菌株的cagA基因3’区相对保守;绝大多数vacA基因属sla／m2型。本研究结果不支持这些基因的多态性与H．pylori感染临床结局相关的观点。     

胃癌与十二指肠溃疡患者血清胃蛋白酶原比较

目的 比较胃癌患者与十二指肠溃疡患者血清胃蛋白酶原水平的差异及探讨其与H．pylori感染的关系。方法 采用时间分辨荧光免疫分析方法检测108例胃癌和96例十二指肠溃疡患者血清胃蛋白酶原Ⅰ、Ⅱ（PGⅠ，PGⅡ），ELISA方法检测血清H．pylori抗体。结果 胃癌和十二指肠溃疡患者之间PGⅠ水平有显著性差异，胃癌组和十二指肠溃疡组中H．pylori阳性和阴性间PGⅠ、PGⅡ、PGⅠ，PGⅡ水平等无显著性差异。结论 胃癌患者血清PGⅠ水平显著低于十二指肠溃疡患者，H．pylori感染对胃癌和十二指肠溃疡患者血清胃蛋白酶原水平和PGⅠ，PGⅡ比值均无影响。     

消化性溃疡患者血管活性肠肽与十二指肠胃反流和幽门螺杆菌感染关系的研究

背景：消化性溃疡（PU）和十二指肠胃反流（DGR）患者的血浆血管活性肠肽（VIP）含量常高于正常水平，而幽门螺杆菌（H.pylori)感染可能参与PU的发病。目的：探讨PU患者的VIP和DGR和H.pylori感染的关系。方法：采用放射免疫测定（RIA）检测34例胃溃疡（GU）患者、42例十二指肠球部溃疡（DU）患者和30例健康人的血浆VIP含量；放射性核素^99mTc-EHIDA显像法测定DGR；双抗体夹心酶联免疫吸附测定（ELISA）检测血清H.pylori IgG抗体，Giemsa染色检测胃黏膜H.pylori。结果：GU组的血浆VIP含量显著高于DU组和正常对照组（P＜0．01）；DGR阳性率亦显著高于DU组（P＜0．05）。DGR阳性组的血浆VIP含量显著高于DGR阴性组（P＜0．01）。H.pyori阳性组的血浆VIP含量显著低于H.pylori阴性组（P＜0．05）。结论：PU患者血浆VIP含量升高可能是DGR发生的重要因素之一。     

幽门螺杆菌阳性十二指肠球部溃疡患者红细胞免疫功能的变化

目的 探讨幽门螺杆菌（Helicobecter pylori）阳性十二指肠球部溃疡患者红细胞免疫功能的变化。方法 47例H．pylori阳性十二指肠球部溃疡患者和32例健康体检者入选，前者以标准方案治疗7天，后者不予处理作为对照。治疗前后分别以流式细胞仪测定其血液红细胞上CR1的数量，以免疫黏附酵母菌花环法测定其活性。结果 与正常人相比，H．pylori阳性十二指肠球部溃疡患者红细胞C3b受体花环率、红细胞CR1数量降低（P〈0．01），红细胞免疫复合物花环率增高（P〈0．01）；根除H．pylori治疗后，上述参数恢复到正常水平。结论 H．pylori阳性十二指肠球部溃疡患者红细胞免疫功能低下，H.pylori的感染可能是导致其红细胞免疫功能低下的原因。     

幽门螺杆菌iceA、cagA相关性研究

目的研究幽门螺杆菌(Helicobecterpylori)cagA、iceA与胃十二指肠疾病的关系及二者的相关性。方法从138例胃黏膜活检组织中分离培养H·pylori,PCR扩增检测cagA、iceA,并测序。结果cagA /iceA1 /iceA2 在消化性溃疡中的阳性率明显高于慢性胃炎和胃癌。cagA、iceA1同时阳性为55·4%(62/112),cagA阴性iceA1阳性为11·5%(3/26),存在统计学差异。cagA、iceA2同时阳性为51·8%(58/112),cagA阴性iceA2阳性为30·8%(8/26),存在统计学差异。结论cagA /iceA1 /iceA2 菌株可能与消化性溃疡的发生、发展相关,cagA和iceA1可能存在协同作用,和iceA2关系不大。     

胃癌易感性白细胞介素-1B基因突变检测芯片的初步临床应用

背景：白细胞介素（IL）-1B基因的单核苷酸多态性（SNP）与胃癌发生密切相关，幽门螺杆菌（H．pylori）感染增加了IL-1B基因突变型宿主胃癌发生的危险性。目的：检测IL-1B基因-31C/T和-511T／C两个位点的多态性．分析其准确性，指导胃癌易感人群的预测和H．pylori感染的个性化治疗，以防治胃癌。方法：取158例胃癌、24例十二指肠溃疡和50例慢性胃炎患者以及98名正常对照者的外周血基因组DNA为模板，聚合酶链反应（PCR）扩增样本IL-1B基因片段，应用Outdo胃癌易感性IL-1B基因突变检测芯片分析-31C／T和-511T／C的基因多态性．并通过测序验证芯片检测的正确性。结果：胃癌组IL-1B-31TT、-511CC和-31TT/511CC基因型的频率显著低于十二指肠溃疡组、慢性胃炎组和正常对照组（21．5％对58．3％、46．0％和57．1％；20．9％对58．3％、50．0％和52．0％；9．5％对45．8％、32．0％和32．7％）（P〈0．05），IL-1B-31CC、-511TT和-31CC／511TT基因型的频率则显著高于十二指肠溃疡组、慢性胃炎组和正常对照组（39．9％对16．7％、24．0％和7．1％；44.3％对12．5％、16．0％和8．2％：23.4％对4．2％、10．0％和5．1％）（P〈0．05）。与测序结果相比，20例基因芯片检测的准确率为100％。结论：IL-1B基因-31T-to-C、-511C-to-T突变与胃癌易感性增加有关。Outdo胃癌易感性IL-1B基因突变检测芯片的检测结果准确可靠．值得进一步研究以确定其临床应用价值。     

十二指肠粘膜胃上皮化生的诊断及临床意义

目的：探讨十二指肠粘膜胃上皮化生的诊断及临床意义。方法：对58例经胃镜检查确诊的十二指肠球部溃疡患者行十二指肠美蓝染色,于不染区或着色区取材作病理检查和快速尿素酶试验。结果：58例患者中,26例于溃疡附近出现斑片状粉红色不染区,13例出现白色不染区,19例着蓝色,三者的胃上皮化生检出率分别为80．8％（21／26）,15．4％（2／13）和10．5％（2／19）,粉红色不染区的胃上皮化生检出率明显高于着色区（P＜0．01）,25例检出胃上皮化生者中22例幽门螺杆菌（H.pylori)阳性（88．0％）,33例无胃上皮化生者中4例H.pylori阳性（12．1％）,前者的阳性率显著高于后者（P＜0．01）,结论：十二指肠美蓝染色用于辨别十二指肠胃上皮化生效果较好,对针对性取材及[观察十二指肠球部溃疡患者胃上皮化生的动态变化有指导意义。     

十二指肠胃反流和幽门螺杆菌感染关系研究

目的：探讨消化性溃疡患者中的十二指肠胃反流对幽门螺杆菌（Hp)感染的影响。方法：70例消化性溃疡患者，用核素^99MTC-EHIDA测定十二指肠胃反流，胃黏膜Giemsa染色后检测Hp和双抗体夹心ELISA法测定血清Hp-IgG水平。结果：在42例十二指肠胃反流阴性组中，Hp感染率为83．3％（35／42）；28例十二指肠胃反流阳性组中，Hp感染率为39．3％（11／28），两组间Hp感染率差异有显著性（P＜0．05）。而Hp阳性组46例患者中，十二指肠胃反流阳性率为30．4％（14／46）；Hp阴性组24例中，十二指肠胃反流率为58．3％（14／24），两组间十二指肠胃反流率差异也有显著性（P＜0．05）。结论：在消化性溃疡中，十二指肠胃反流对胃内Hp感染可能有抑制作用。     

H pylori iceA alleles are disease-specific virulence factors

AIM: To characterize and compare genotype profiles of H pylori strains isolated from patients with chronic gastritis and duodenal ulcer in western part of Turkey. METHODS: A total of 46 patients [30 chronic gastritis (CG) and 16 duodenal ulcer (DU)] who had undergone endoscopy because of dyspeptic complaints were studied. The antral biopsy specimens were evaluated for the presence of H pylori by rapid urease test and culture, and the genotype profiles were determined by real-time PCR. RESULTS: The cagA gene was observed in 43 (93.5%) isolates. The vacA s1m2 genotype was the predominant subtype, found in 63.3% and 68.7% of isolates in patients with CG and DU, respectively. Twenty (66.6%) isolates from patients with CG were iceA2 positive while the iceA1 was predominant in those with DU (68.8%). In terms of the association of the iceA alleles to other genes, both alleles were significantly associated with the cagA vacA s1m2 genotype. CONCLUSION: The prevalent circulating genotypes in CG and DU were cagA vacA s1m2 iceA2 and cagA vacA s1m2 iceA1 genotype, respectively. It was found that cagA vacA s1m2 genotype seems to be common virulence factors in both CG and DU while iceA alleles show specificity for gastroduodenal pathologies in this study.     

Helicobacter pylori genotypes and expression of gastritis in erosive gastro-oesophageal reflux disease

BACKGROUND: Epidemiological studies suggest a negative association between Helicobacter pylori and gastro-oesophageal reflux disease (GORD). Moreover, cagA-positive strains are reported to protect from complications of GORD. The aim of this study was to determine virulence factors (cagA, vacA and iceA) of H. pylori strains and the pattern of gastritis in patients with GORD in comparison with patients with duodenal ulcer (DU) or functional dyspepsia (FD). METHODS: H. pylori strains isolated from gastric biopsies of 105 consecutive patients with mild to moderate erosive GORD (n = 35, LA grade A-B), and from sex- and age-matched patients with DU (n = 35) or FD (n = 35 without reflux symptoms) were investigated. CagA, vacA, and iceA genotypes were determined by PCR analysis of the isolates. Gastritis was classified in accordance with the updated Sydney classification. RESULTS: The prevalence of all three H. pylori virulence factors was higher in patients with GORD (cagA+ 80%, vacA s1 77%, iceA1 71%) and DU (cagA+ 83%, vacA s1 80%, iceA1 74%) than in patients with FD (cagA+ 40%, vacA s1 49%, iceA1 46%). Gastritis activity in the antrum and corpus did not differ between the three groups. However, lymphocytic infiltration of the gastric antral mucosa was more pronounced in DU patients than in those with GORD or FD. CONCLUSIONS: H. pylori strains obtained from patients with mild to moderate erosive GORD show a virulence pattern similar to that found in DU patients. The presence of these virulence factors does not appear to protect against erosive lesions in the oesophagus.     

H pylori status and angiogenesis factors in human gastric carcinoma

INTRODUCTION H pylori infection is a well-known risk factor for the development of pre-neoplastic and neoplastic gastric mucosal alterations[1,2]. An increase in proliferative activity of gastric epithelial cells without a corresponding increase in apopto…     

Colonization with cagA-positive Helicobacter pylori strains in intestinal metaplasia of the esophagus and the esophagogastric junction

OBJECTIVES: Recent studies indicate that colonization with cagA-positive Helicobacter pylori (H. pylori) strains may protect against gastroesophageal reflux disease (GERD) and its complications, but the role of cagA in the etiology of Barrett's esophagus has so far been poorly investigated. The pathogenesis of intestinal metaplasia (IM) at an endoscopically normal esophagogastric junction (EGJ) is still unclear, and the role of the H. pylori virulence factor cagA in it has not been investigated. The aim of our study was to assess the relationship between H. pylori and cagA-positive H. pylori in particular and IM at an endoscopically normal EGJ and Barrett's esophagus. METHODS: Serum samples were obtained from 62 patients without IM, 43 patients with IM at an endoscopically normal junction, and 51 patients with Barrett's esophagus. IM was defined as presence of goblet cells with positive staining with Alcian blue. The prevalence of H. pylori and cagA was investigated by assessment of IgG antibody levels as determined by ELISA. RESULTS: The overall H. pylori prevalence was 59% (92/156), and the cagA prevalence was 29% (46/156). Although 63% (39/62) of IM negative subjects and 74% (32/43) of those with IM at the junction were H. pylori positive, only 41% (21/51) of Barrett's patients tested positive. The differences between the IM negative and the Barrett's group (p = 0.02) and between IM at the junction and Barrett's were significant (p = 0.002). The relative cagA prevalence (percentage with cagA positivity and H. pylori positivity) was 56% (22/39) in patients who were IM negative, 59% (19/32) in those with IM at the junction, and 24% (5/21) in those with Barrett's. The prevalence of anti-CagA was significantly lower in patients with Barrett's esophagus compared with patients who were IM negative (p = 0.002) and those who had IM at the junction (p < 0.001). No difference in cagA prevalence was seen between the latter groups. CONCLUSIONS: These findings are in line with the concept that H. pylori and cagA-positive strains in particular protect against the development of Barrett's esophagus. In contrast, our findings do not support the theory that IM at an endoscopically normal esophagogastric junction is associated with H. pylori or cagA-positive strains. IM at the junction and Barrett's esophagus seem to have different etiologies.     

CagA status and virulence of Helicobacter pylori strains. Results of a French multicentric prospective study

Previous experimental and epidemiological studies with few patients suggested that the presence of the cagA gene was a virulence factor for Helicobacter pylori (H. pylori). AIM: To establish in this large epidemiological cohort study the relationship between the histological virulence of H. pylori infection and the cagA status of the bacteria. METHODS: This prospective cohort study (6 month follow-up) was conducted on adult patients undergoing endoscopy for upper gastrointestinal symptoms. The cagA status of H. pylori-positive patients was established using the polymerase chain reaction (PCR) method on an antral biopsy. A score of histological virulence (inflammation, activity) was recorded on the basis of the Sydney system (on antral, angular and fundic biopsies). Eradication treatment given was not imposed and a clinical follow-up was performed at 3 and 6 months. H. pylori eradication was verified by a 13C urea breath test at 3 months. RESULTS: Four hundred and twenty two centers recruited 652 patients (mean age: 51 +/- 15 years, 55% female). Upper GI endoscopy was abnormal in 80% of the patients of whom 68% had a gastritis aspect; 38% were infected by H. pylori, and among them 51% were cagA-positive. The histological virulence scores associated with the cagA-positive strains were significantly higher than those associated with the cagA-negative strains, globally (P = 0.0035), in the antrum (P = 0.0063), and in the angulus (P = 0.046), but not in the fundus (P = 0.05). The cagA status was correlated neither with the symptom severity at inclusion and at 6 months (P > 0.05), nor with the H. pylori eradication rate at 3 months (75% in cagA-positive and 70% in cagA-negative strains, P = 0.52). CONCLUSION: This study on a large cohort of patients confirms the greater histological virulence of H. pylori cagA-positive strains. However, this virulence was not associated with more severe symptoms nor with an increase in resistance to H. pylori eradication treatment.     

Detection of Helicobacter pylori cagA gene by polymerase chain reaction in faecal samples.

OBJECTIVE: The polymerase chain reaction (PCR) has been extensively and successfully used to detect Helicobacter pylori in gastric juice and gastric biopsies. In contrast, the results obtained using faeces as biological samples for PCR are rather conflicting. This may be due to the presence of faecal inhibitory compounds (polysaccharides) which can inhibit the amplification reaction. The aim of this study was to characterize the H. pylori genotype in faecal samples by using specific primers for the cagA gene. To overcome the problem of contamination by polysaccharides, we used a filter-based extraction technique already applied in a previous study. METHODS: Antral and body biopsies were obtained from 30 symptomatic patients undergoing upper endoscopy. PCR was used to detect the presence of H. pylori organisms in faecal samples by using primers selected for the urease gene A. In addition, H. pylori organisms were characterized both in faecal samples and paraffin-embedded biopsies by PCR with specific primers for the cagA gene. RESULTS: All patients showed a positive CLO test (rapid urease test) and evidence of H. pylori by Warthin-Starry stain. PCR detected the urease A gene in the faecal samples of all patients. The cagA gene was detected in the faecal and biopsy samples of 18 subjects (60%). Duodenal ulcer and/or antral erosions were observed in 15 of the 18 cagA-positive patients (83.3%) and in five of the 12 cagA-negative patients (41.7%). Endoscopic features of normal mucosa or gastritis were observed in three cagA-positive patients (16.7%) and in seven cagA-negative patients (56.3%). cagA-positive status was found to be significantly related to the endoscopic features of duodenal ulceration and/or antral erosions. CONCLUSIONS: Our findings prove that faeces are suitable samples for the detection of cagA status. Moreover, they confirm the existence of a significant relationship between cagA-positive status and duodenal ulcer and/or antral erosions.     

Functional dyspepsia is associated with cagA-positive Helicobacter pylori strains

BACKGROUND: The antigen CagA can be used as a marker for virulence of Helicobacter pylori. It is tempting to assume that H. pylori strains positive for cytotoxin-associated gene A (cagA) could be responsible for functional dyspepsia. A cross-sectional study was performed in patients presenting with functional dyspepsia to correlate the clinical presentation with the presence of cagA-positive and -negative H. pylori strains. METHODS: Consecutive patients referred for endoscopy were studied. An inclusion criterion was the absence of any endoscopic abnormality. Biopsy specimens were obtained from the gastric antrum for HE and immunoperoxidase stain, rapid urease test, and culture. A serum sample was taken for detection of IgG antibodies against H. pylori as well as CagA. A validated questionnaire of 14 questions regarding the upper gastrointestinal tract was used for assessment of the clinical presentation. Nine questions were scored on a 5-point Likert scale. RESULTS: 422 patients were included, 222 were H. pylori-positive, the remaining 200 were H. pylori-negative. Mean symptom score in patients with cagA-positive strains was significantly higher than in patients with cagA-negative strains. No difference was present if cagA-negative patients were compared with H. pylori-negative dyspeptics. Four different complaints were more prevalent in the cagA-positive patients compared with cagA-negatives. When cagA-positive patients were compared with H. pylori-negative dyspeptics, seven complaints were significantly more prevalent in cagA-positives; when cagA-negatives were compared this number was only two. CONCLUSIONS: Functional dyspeptics with cagA-positive H. pylori strains have more dyspeptic symptoms and higher symptom scores than patients with cagA-negative H. pylori strains as well as H. pylori-negative functional dyspeptics.     

Bleeding peptic ulcers and presence of Helicobacter pylori by various tests: a case-control study

BACKGROUND: Virulence factors of Helicobacter pylori are associated with peptic ulcer disease and may be also associated with bleeding peptic ulcers (BPU). AIM: To determine whether H. pylori and/or the cytotoxin-associated gene (cagA) can increase the risk of bleeding in peptic ulcers. PATIENTS: Sixty-seven patients were studied. Thirty had BPU, 20 had non-bleeding peptic ulcers (NBPU), and 17 were control subjects (NPU). METHODS: The prevalence of H. pylori was assessed by the urease fast test, histological examination, serology, and 16S ribosomal RNA and cagA gene amplification by polymerase chain reaction (PCR). RESULTS: Histology and PCR showed greater sensitivity for diagnosis of H. pylori under bleeding circumstances when compared with other tests. Association of H. pylori was greater in the NBPU group (odds ratio [OR] 4.91, P = 0.06) than in the BPU group (OR 1.27, P = NS) when compared with the control group. When the BPU and NBPU groups were compared, H. pylori was found more often in the NBPU group (OR 0.26, P < 0.10 ). The cagA-positive gene showed a similar distribution in the three groups. The titres for anti-CagA immunoglobulin A (IgA) antibodies were higher in NBPU patients (83%) than in BPU or control patients. Furthermore, anti-urease immunoglobulin G (IgG) was detected more frequently among BPU and NBPU patients. CONCLUSIONS: NBPU patients had the highest prevalence of H. pylori by PCR. It seems unlikely that either H. pylori or the cagA-positive gene act as significant risk factors for bleeding in peptic ulcers. The lower prevalence of the microorganism among patients who bleed cannot be explained as an artificial finding.