幽门螺杆菌粘附素的研究进展

幽门螺杆菌与胃的上皮细胞的强力粘附作用是幽门螺杆菌的粘附素与胃上皮细胞上受体相结合所致，其粘附作用的特异性揭示存在着复杂的粘附素和受体系统。本文综述了有关幽门螺杆菌粘附素的理化特性、基因与受体及其致病性等研究进展。     

与克拉霉素耐药相关的幽门螺杆菌基因23S rRNA序列分析

幽门螺杆菌是寄生于人体胃部的革兰阴性杆菌,是胃溃疡、十二指肠球部溃疡和胃癌的主要致病因素之一,与胃黏膜相关淋巴组织淋巴瘤关系密切.随着大环内酯类抗生素广泛应用于治疗幽门螺杆菌感染,幽门螺杆菌的耐药现象日益严重.现已证实,幽门螺杆菌对克拉霉素耐药主要与其23S rRNA基因的点突变有关.为此,本研究通过对江苏苏中沿海地区分离培养的幽门螺杆菌菌株的23S rRNA部分基因片段进行序列分析,希望了解本地区幽门螺杆菌耐药菌株的基因突变和耐药的关系.     

幽门螺杆菌粘附素的研究进展

幽门螺杆菌与胃的上皮细胞的强力粘附作用是幽门螺杆菌的粘附素与胃上皮细胞上受体相结合所致，其粘附作用的特异性揭示存在着复杂的粘附素和受体系统。本文综述了有关幽门螺杆菌粘附素的理化特性，基因与受体及其致病性等研究进展。     

幽门螺杆菌尿素酶基因的克隆及表达

目的构建幽门螺杆菌尿素酶基因B亚单位（ureB）的原核表达质粒,诱导重组蛋白表达。方法以幽门螺杆菌基因组DNA为模板,PCR扩增尿素酶基因B亚单位,扩增产物经琼脂糖凝胶电泳分离后连接克隆载体并测序,构建重组原核表达载体。结果成功扩增出1710bp的目的基因,测序结果证实与预期一致,该基因在大肠杆菌表达系统中得到表达。结论在大肠杆菌中成功表达幽门螺杆菌尿素酶基因B亚单位蛋白,为幽门螺杆菌疫苗的研发奠定了基础。     

聚合酶链反应法测定幽门螺杆菌的vacA基因型

以幽门螺杆菌ＤＮＡ为模板,采用聚合酶链反应设计了５个特异性寡核苷酸引物的一个共引物,分析检测了６２株幽门螺杆菌空泡形成细胞毒素基因Ｓ１ａ、Ｓ１ｂ、Ｍ１型和Ｍ２型,检测结果均为Ｓ１ａ／Ｍ２实验显示胃十二指肠疾病与空泡形成细胞毒素基因无相关关系。     

聚合酶链反应法测定幽门螺杆菌的vacA基因型

以幽门螺杆菌DNA为模板,采用聚合酶链反应设计了5个特异性寡核苷酸引物和一个公共引物,分析检测了62株幽门螺杆菌空泡形成细胞毒素基因S1a、S1b、M1型和M2型,检测结果均为S1a/M2型.实验显示胃十二指肠疾病与空泡形成细胞毒素基因无相关关系.     

幽门螺杆菌毒力基因与临床相关性的分析

目的了解上海地区幽门螺杆菌临床分离株毒力基因携带的分子特征,探究其基因型与临床幽门螺杆菌感染性胃十二指肠疾病的相关性。方法收集514例临床胃黏膜活检样本,分离培养幽门螺杆菌;设计和合成10对幽门螺杆菌毒力基因型的特异性引物,检测临床分离的幽门螺杆菌中携带的毒力基因,并分析其与幽门螺杆菌感染相关的临床疾病[慢性浅表性胃炎、慢性萎缩性胃炎和消化性溃疡(PUD)]的相关性。结果从514例胃黏膜活检样本中分离出幽门螺杆菌129株。幽门螺杆菌分离株携带多种毒力基因,包括cag A、vac A(m1、m2、s1)、ice A1、ice A2、dup A、lux S、oip A,其中vac A s1m2基因型与ice A1~+/ice A2~+混合基因型增加了PUD发生的危险程度,而vac A s1m1基因型则是慢性活动性胃炎的危险因素。dup A显著增加了十二指肠溃疡的危险度。结论上海地区幽门螺杆菌携带多种毒力基因,ice A1~+/ice A2~+和vac A s1m2基因型可能是PUD危险因子。dup A可考虑作为十二指肠溃疡的标记分子。     

幽门螺杆菌无创性分子生物学检测方法研究进展

幽门螺杆菌与慢性活动性胃炎、消化性溃疡、胃黏膜相关淋巴组织淋巴瘤和胃癌等消化系统疾病密切相关,是目前唯一被世界卫生组织列为Ⅰ类致癌原的病原菌。随着分子生物学技术的发展,关于幽门螺杆菌鉴定、耐药或毒力基因分析的分子生物学方法不断更新,对幽门螺杆菌的精准诊疗具有重要意义。从口腔和粪便样本中直接检测幽门螺杆菌的无创性分子生物学检测方法具有简便、高效、经济和非侵入性等优点,已成为相关领域的研究热点。文章介绍了幽门螺杆菌无创性分子生物学检测方法的研究进展,并对多种幽门螺杆菌常规检测方法的利弊进行比较,以期为幽门螺杆菌的临床诊治提供参考。     

纳米金辅助不对称PCR扩增幽门螺杆菌23S rRNA基因的优化和建立

目的:建立纳米金辅助不对称PCR方法扩增幽门螺杆菌23S rRNA基因,为建立基因芯片法检测幽门螺杆菌耐药基因提供试验平台.方法:将幽门螺杆菌23S rRNA基因转化至感受态大肠杆菌JM109,小量抽提阳性构建质粒DNA,以质粒DNA为模板,设计引物对23S rRNA基因进行不对称PCR扩增.对PCR条件中引物浓度及浓度比例、纳米金浓度等进行优化.结果:限制性引物与非限制性引物浓度比例为1 ∶ 60,限制性引物与非限制性引物浓度分别为0.04 pmol/L、2.4 pmol/L时可获得理想的单链和双链DNA,纳米金浓度为0.8 nmol/L时非特异性产物最少,PCR的扩增效率最高.结论:通过对PCR扩增条件的优化,确立了扩增幽门螺杆菌23S rRNA基因纳米金辅助不对称PCR方法的最佳条件,为建立基因芯片法检测幽门螺杆菌耐药基因奠定基础.     

幽门螺杆菌与胆囊胆固醇结石形成关系的研究

目的 研究胆囊幽门螺杆菌感染与胆囊胆固醇结石形成的关系.方法 我院2002年6月至2004年1月肝胆外科腹腔镜胆囊切除术60例,采用对照研究方法,对35例单纯胆囊结石患者(实验组)及25例单纯胆囊息肉患者(对照组)的胃幽门螺杆菌进行检测,采用PCR方法检测2组患者的胆汁及结石幽门螺杆菌细胞毒素相关基因抗原(CagA).结果 实验组胃幽门螺杆菌感染率为51.43%(18/35),对照组为48.00%(12/25),2组患者胃幽门螺杆菌感染率差异无统计学意义(χ~2=0.079,P>0.05).实验组胆汁标本中CagA 7例阳性(20.00%),结石标本中1例阳性(2.86%),对照组胆汁标本无一例阳性,2组胆汁CagA检出率差异有统计学意义(χ~2=5.822,P<0.05).结论 幽门螺杆菌DNA存在于胆囊胆固醇结石患者的胆汁及结石中,与胃幽门螺杆菌感染有关,胆囊幽门螺杆菌感染与胆囊胆固醇结石形成有关.     

幽门螺杆菌传播和定植机制研究进展

幽门螺杆菌是一种定植于宿主胃黏膜上皮细胞层的微需氧、螺旋状革兰阴性杆菌。幽门螺杆菌感染会持续数十年,可致胃肠道疾病,甚至引发胃癌。世界卫生组织将幽门螺杆菌定义为Ⅰ类致癌因子,其感染率非常高,我国部分地区感染率甚至超过80%,且呈逐年上升的趋势。幽门螺杆菌感染影响因素较多,但传播和定植是关键。文章就幽门螺杆菌在传播和定植方面的研究进展作一综述。     

儿童牙垢幽门螺杆菌抗原检测的临床研究

目的探讨牙垢幽门螺杆菌抗原检测在诊断儿童幽门螺杆菌感染及治疗后复查的价值。方法采用天津瑞爱金生物科技有限公司幽门螺杆菌快速检定卡对56例有消化道症状的患儿牙垢幽门螺杆菌抗原检测,并同时进行胃黏膜抗原检测,以胃黏膜幽门螺杆菌抗原为标准,对牙垢幽门螺杆菌抗原检测方法进行评价。结果胃黏膜幽门螺杆菌抗原检测阳性47例、阴性9例,牙垢幽门螺杆菌抗原检测阳性50例。阴性6例。胃黏膜幽门螺杆菌抗原阳性中有1例牙垢幽门螺杆菌抗原阴性,胃黏膜幽门螺杆菌抗原阴性中有4例牙垢幽门螺杆菌抗原阳性。牙垢幽门螺杆菌抗原检测HP感染的敏感度97．9％（46／47）,阳性预测值为92％（46／50）,阴性预测值为83．3％（5／6）,检测的准确性为91．1％（51／56）。结论牙垢幽门螺旋杆菌抗原检测法可提供一种非侵人性的Hp检测法,具有取材方便、操作简单、快捷,多次重复获取牙垢标本,患儿无痛苦,又经济,是儿童HP感染的诊断及治疗后复查最好的方法。     

幽门螺旋杆菌感染与子痫前期的关系

幽门螺旋杆菌是最常见的消化道致病菌,参与急性胃肠炎、消化性溃疡、胃肠肿瘤等胃肠道疾病的发生发展, 与胃肠外疾病也有密切联系。研究发现,幽门螺旋杆菌感染与子痫前期存在明确的流行病学因果关系,特别是细胞毒素相关基因A(cytotoxin-associated gene A, cagA)阳性的幽门螺旋杆菌菌株诱导产生的抗cagA抗体可与滋养层细胞发生免疫反应导致滋养细胞浸润异常。此外,幽门螺旋杆菌感染引起的炎症反应、脂质代谢异常可造成血管内皮功能异常,导致子痫前期。本文将对幽门螺旋杆菌感染与子痫前期的关系作一综述。     

Economic evaluation of H. pylori eradication

A review of economic evaluation studies of Helicobacter pylori eradication was performed. As a result of the high quality and quantity of data emerging, the eradication therapy for patients with gastric or duodenal ulcer was considered to be less costly and more effective than conventional therapy in a Japanese clinical setting. Furthermore, population-based Helicobacter pylori screening was seemed to have the potential to produce important health benefits at a reasonable cost, especially in Japan. Controlled studies are needed to quantify the impact of Helicobacter pylori eradication on the risk of gastric cancer to confirm it.     

Helicobacter pylori strikes again: gastric mucosa-associated lymphoid tissue (MALT) lymphoma.

Infection with Helicobacter pylori is common. Over 50% of the world's population is estimated to be colonized with the bacteria. The association between Helicobacter pylori and gastric mucosa-associated lymphoid tissue (MALT) lymphoma is well documented. Anti-Helicobacter pylori treatment and the successful eradication of the bacteria can potentially cure patients who test positive for the bacteria and who are diagnosed with low-grade gastric MALT lymphoma. The purpose of this article is to review the evidence implicating Helicobacter pylori as a causal pathogen for the development of gastric MALT lymphoma and to determine that anti-Helicobacter pylori therapy is an effective first-line treatment. The clinical presentation, endoscopic findings, diagnosis, staging, treatment, and follow-up of patients with gastric MALT lymphoma who are treated with anti-Helicobacter pylori therapy are also discussed.     

Activity of cefixime against Helicobacter pylori and affinities for the penicillin-binding proteins.

Cefixime induced the formation of rounded cells from the spiral bacillary form of Helicobacter pylori at the MIC or less. Three main penicillin-binding proteins, called A, B and C, were separated from H. pylori. Cefixime had the strongest affinity to penicillin-binding protein B. The binding of cefixime to this protein may induce the formation of rounded H. pylori cells.     

The 13C-urea breath test efficacy in determining Helicobacter pylori eradication

Helicobacter pylori eradication therapy is useful and requires more precise determination of actual eradication. Patients often become positive for Helicobacter pylori again after presumed eradication. Reinfection is thought rare and patients with positive reconversion may be false-negative at determination. After a year, positive reconversion was 26.8% in our work after determination by culture and histopathological methods and 4.3% after these were combined with urea breath test (UBT). The positive reconversion rate is significantly lower after combination with UBT, suggesting the usefulness of UBT in determining Helicobacter pylori eradication. This may be because UBT includes no biopsy, eliminating sampling error, and highly sensitive UBT detects traces of Helicobacter pylori. The UBT is thus expected to become widely used to determine Helicobacter pylori eradication.     

Helicobacter pylori Infection in Various ABO Blood Groups of Kashmiri Population

Aim: This study was carried out to assess the prevalence of Helicobacter pylori infection in various ABO blood groups of people of Kashmir.Method: The study comprised 80 individuals - 50 peptic ulcer patients (whose disease was diagnosed by endoscopy) and 30 asymptomatic volunteers. Every subject's blood group and Rhesus status was determined by standard serological tests. Helicobacter pylori infection was diagnosed by three different methods viz., one minute endoscopy room test (urease test), Gram staining and by histology. The detection of Helicobacter pylori by histological examination using Giemsa staining was taken as the 'gold standard' for the presence of Helicobacter pylori infection.Results: Out of 80 individuals, 67 were males and 13 females aged between 18-65 years. The majority of peptic ulcer patients had blood group 'O' (n = 28.56%). The prevalence of Helicobacter pylori infection amongst peptic ulcer patients was 76%. There was no difference in Helicobacter pylori positivity in various blood groups.Conclusion: Blood group 'O' though a risk factor for peptic ulcer (Duodenal ulcer) is not a risk factor for acquiring Helicobacter pylori infection.     

骨科植入物表面细菌生物膜的研究与机制

背景：细菌形成生物膜后耐药性极强,而外科感染特别是骨科植入物感染与植入材料表面形成细菌生物膜密切有关。目的：综述了细菌生物膜形成、结构、影响因素、耐药机制及防治措施的研究进展。方法：以＂Bacterial biofilm,Drug resistance,Implant,Infection＂为英文检索;以＂细菌生物膜,耐药性,植入物,感染＂中文检索词,检索CNKI和PubMed数据库1982年1月至2011年9月有关细菌生物膜及其防治,植入物术后感染形成生物膜相关研究。纳入34篇文献进行分析。结果与结论：抗生素应用不能有效清除细菌生物膜,还可诱导耐药性产生。改变生物膜的微环境、选择生物相容性好的内植入材料和降低细菌的黏附性可以更加有效控制感染。     

幽门螺杆菌动力在胃黏膜定植中的机制研究

幽门螺杆菌能在人类的胃定植并且在胃内存活数十年甚至一生,幽门螺杆菌有很多潜在的致病因子使其定植在胃的特殊环境中.动力是必须的定植因子,依据于幽门螺杆菌无动力突变株不能感染无菌乳猪,动力不能作为定植因子是因为在活体胃腔内幽门螺杆菌的动力很快失去,幽门螺杆菌动力的作用尚未清楚.本文的目的 是探讨对定植与幽门螺杆菌动力之间的关系.