Dominant cagA/vacA genotypes and coinfection frequency of H. pylori in peptic ulcer or chronic gastritis patients in Zhejiang Province and correlations among different genotypes, coinfection and severity of the diseases

Background Almost half of the world’s population suffer from the Helicobacter pylori (H. pylori) infection, but only some individuals develop gastric diseases with clinical symptoms. One reason for the phenomenon may be the different pathogenicity of infected H. pylori strains. The presence of cytotoxin-associated gene A (cagA) and expression of vacuolating cytotoxin activity encoded by vacuolating cytotoxin gene A (vacA) are considered the two major virulent markers of H. pylori. The aim of this study was to detect dominant cagA/vacA genotypes and coinfection frequency of H. pylori in patients with peptic ulceration (PU) or chronic gastritis (CG), and to determine correlations among different cagA/vacA genotypes, coinfection and severity of the diseases. Methods For each of 139 patients in Zhejiang Province who had been diagnosed as PU or CG based on clinical symptoms and gastroscopy, two gastric biopsy specimens (one from antrum and the other from corpus) for H. pylori isolation were taken by two different disinfected biopsy forceps. One hundred and fifty-six H. pylori strains were isolated from both the antrum and corpus biopsy specimens of 78 patients (36 PU and 42 CG). PCRs were performed to detect cagA genes, and signal (s) and middle (m) regions of vacA genes in the H. pylori isolates. The amplified fragments of dominant vacA gene s and m subtypes from representative H. pylori isolates were sequenced after TA cloning. Dominant cagA/vacA genotypes of the H. pylori isolates, coinfection frequency and correlations among the different genotypes, coinfection and severity of the diseases were determined.Results Of the H. pylori strains isolated from the antrum specimens, 96.2% were cagA gene positive, as were 97.4% of the H. pylori strains isolated from the corpus specimens. Only one s region subtype (s1a) and four m region subtypes m1, m2, m1b and m1b-m2 of vacA gene were found. The proportions of vacA gene subtypes s1a/m1, s1a/m2, s1a/m1b and s1a/m1b-m2 in the 83 strains isolated from the antrum specimens were 7.2%, 61.5%, 30.1% and 1.2%, respectively, while those in the other 84 strains isolated from the corpus specimens were 9.5%, 58.3%, 28.6% and 3.6%, respectively. s1a/m2 (58.3% vs 30.1%, χ2=13.47, P<0.01) and then s1a/m1b (28.6% vs 9.5 %, χ2=9.88, P<0.01) were the dominant vacA gene subtypes in the H. pylori isolates. The dominant H. pylori genotype was cagA+s1a/m2 (59.0% from antrum specimens and 57.1% from corpus specimens), and followed by cagA+s1a/m1b (28.9% from antrum specimens and 27.4% from corpus specimens). Sixteen of 78 patients (20.5%) were infected with two or three H. pylori strains with different genotypes. However, no statistically significant differences among cagA occurrence, the different vacA subtypes and PU or CG could be found (each P>0.05). Similarities of the nucleotide sequences from vacA gene s region PCR products of six isolates and from vacA gene m region PCR products of four isolates were 93.2% to 98.3% and 93.8% to 97.6%, respectively, compared to the reported corresponding sequences.Conclusions The dominant genotypes of H. pylori in PU or CG patients in Zhejiang area may be cagA+ s1a/m2 and cagA+ s1a/m1b. Numerous coinfections with different H. pylori strains in PU or CG patients indicate diversity of the infected H. pylori origins. s and m regions of vacA gene from different H. pylori isolates show high nucleotide sequence similarities. cagA gene positive rate, different vacA gene subtypes and coinfection with different H. pylori strains are not closely associated with severity of the diseases.     

Detection and amplification of Helicobacter pylori urease gene A in gastric biopsies by using nested polymerase (?)hain reaction

A nested polymerase chain reaction(N-PCR)for the spegific detection of Helicobacterpylori(H.pylori)was developed with two primer pairs(nested primers)derived from ureasegene A of H.pylori.The N-PCR was used to detect 21 different samples of H.pylori including20 clinical isolates and 1 reference strain NCTC 14126,but it was negative for other bacterialspecies,showing the N-PCR assay to be 100% specific.Tenfold serial dilution experiments re-vealed the detection of as little as 0.1 fg of H.pylori DNA by N-PCR.To evaluate the PCR as-say for clinical samples,gastric biopsies were tested with N-PCR,and the results were comparedwith those of culture,urease test and histologic examination(reference standard,RS).In 30biopsy specimens,H.pylori DNA sequences were detected by PCR in all of 20(100%)positivetissue and none of the 10 negative tissues.PCR is a specific and sensitive method that can detectthe presence of H.pylori without the need for culture and would have significant importance di-agnostically and epidemiologically.     

RFLPs FOR HUMAN PAI-1 GENE IN CHINESE

Plasminogen activator inhibitor 1 (PAI-1) is considered as the main physiological inhibitor of plasminogen activators in plasma which plays an important regulatory role in the control of the fibrinolytic activity in blood. The human PAI-1 gene is located at q21-22 region of chromosome 7. By using human PAI-1 cDNA (a gift from Dr. D. Ginsburg) as a probe, restriction fragment length polymorphisms (RFLPs) were studied with 8 different endonucleases in 35 unrelated Chinese individuals and the results showed as follows: (1) Taq Ⅰdetected allelic 2.7 kb and 1.8 kb fragments, with the frequencies of 0.96 and 0.04 respectively, 2.7 kb homozygote and 2.7 kb/1.8 kb heterozygote appeared with frequencies of 91% and 9%. (2) Sac Ⅰidentified an invariant 4.8kb band and a two-allele polymorphism with fragments of either 23 kb or 16 kb whose frequencies were 0.96 and 0.04. 23kb homozygote and 23kb/16kb heterozygote appeared with the frequencies of 91% and 9%. (3) HindⅢrevealed a single two-allele polymorphism with bands at either 25 kb or 14 kb, with the frequencies of 0.34 and 0.66, 25 kb homozygote, 25 kb/14 kb heterozygote and 14 kb homozygote appeared with the frequencies of 23%, 46% and 31% respectively. The restriction fragment with a size of 1.6kb for TaqⅠwas first reported in the present paper. No polymorphism was observed for EcoRI, BamHI, BglⅡ, PvuⅡand Pst Ⅰ. The RFLPs for PAI-1 gene may be served as important genetic markers for study of thrombotic and other PAI-1 related disorders.     

左旋苦豆子总碱可增加扩展β-内酰胺酶产生的大肠杆菌分离株对头孢噻肟、头孢他啶的敏感性

Objective： To evaluate the antimicrobial activity of total alkaloids extracted from Sophorea alopecuroides L. （TASA） against clinical isolated extended-spectrum beta-lactamases （ESBLs） producing Escherichia coil （E.. coil） strains. Methods： The antibacterial activity of TASA either itself or in combination with cefotaxime （CTX） or ceftazidime （CAZ） was investigated by using the microbroth dilution method and phenotypic confirmatory disk diffusion test against three clinical isolated ESBLs-producing E. coil strains; the interactions of TASA and C＇I＇X or CAZ were ascertained by evaluating the fractional inhibitory concentration index （FICI）. Results： The antibacterial activity of either TASA itself or in combination with C＇IX or CAZ was found. The minimum inhibitory concentration （MICs） of TASA against the ESBLs producing isolates was 12.5 mg/mL. In the combinations with a sub-inhibitory concentration of TASA, a synergistic effect on CTX and CAZ against the ESBLs producing isolates was observed. Similarly, the isolates exposed to lower dose of TASA yielded an increased susceptibility to CTX and CAZ by 8-16 folds determined by microdilution assay. Moreover, enzymatic detection of ESBLs demonstrated that TASA induced reversal resistance to CTX and CAZ partially by a mechanism of inhibition of ESBLs activity in these isolates. Additionally, in the tested isolates following the exposure of TASA, molecular analysis verified the SHV-type beta-lactamase encoding ESBL gene in these isolates, and no mutation was introduced into the ESBL gene. Conclusions： These results suggest that TASA could be used as a source of natural compound with pharmacological activity of reversal resistance to antimicrobial agent. These findings also indicated that the application of the TASA in combination with antibiotics might prove useful in the control and treatment of infectious diseases caused by the ESBLs producing enterobacteriaceae.     

Emergence of Klebsiella pneumoniae carbapenemase-producing Escherichia coli sequence type 131 in Hangzhou, China

Background Klebsiella pneumoniae carbapenemase （KPC）-producing Escherichia （E.） coil has been reported in China since 2008.However,there is no information about the molecular epidemiology of KPC-producing E.coil in China.In this study,we aimed to investigate the sequence type （ST） and characteristics of KPC-producing E.coil isolates in China.Methods Three carbapenem-resistant isolates of E.coil （E1,E2,and E3） from one teaching hospital in Hangzhou covering a one year period were analyzed.Antibiotic susceptibility was determined by Etest.Pulsed-field gel electrophoresis （PFGE） and multilocus sequence typing （MLST） were used for epidemiological analysis.The genetic structure around blaKPC,the major plasmid incompatibility typing,and the identification of 3-lactamase gene types were performed by PCR and the positive products were subsequently sequenced.Plasmids were analyzed by transformation,restriction,and Southern blotting.Results PFGE demonstrated that patterns of isolates E1 and E2 were clonally-related and designated as patterns A1 and A2; pattern of isolate E3 was different and designated as pattern B.MLST analysis showed that the three isolates displayed one common sequence type ST131.The identification of bla gene types by PCR and sequencing showed that blaKPC-2,blaCTX-M-14,and blaTEM-1 were detected in all three isolates.All three isolates carried a KPC-2-encoding plasmid of the IncN replicon.Plasmid analysis and hybridization experiments showed that the isolates were found simultaneously to carry two or four plasmids.The blaKPc-2 gene in E1 and E2 was located in a plasmid with size of ca.50 kb.However,the blaKPC-2 gene in E3 was located in a plasmid with size of ca.130 kb.Conclusions E.coil ST131 with KPC-2 β-1actamase has emerged in China,which enlarges the geographical area where the ST131 KPC-oroducing E.coil strains have diffused.     

Characterization of Class 1 Integron Gene Cassettes among Clinical Bacteria Isolated from One Large Hospital in Northern China

The class 1 integron and complex gene cassettes among different species of clinical isolates in northern China were characterized in this study. 383 clinical isolates were obtained from northern China, and class 1 integrons containing gene cassettes widely distributed among gram negative clinical isolates was observed. We find that the class 1 integron showed positive correlation with multidrug resistance phenotype of gram negative bacteria. In addition, we find that isolates belonged to one species harbored different types of gene cassette arrays, while same types of gene cassette arrays were observed in different species of isolates. The diversity of gene cassette arrays among the isolates indicated the complexity of multidrug resistance in clinical isolates in northern China.     

Whole CanA Gene Amplification of Helicobacter pylori and Its Fingerprinting by Restriction Fragment Length Polymorphism

To set up a method of amplification for the whole CagA gene of Helicobacter pylori and its fingerprinting by restriction fragment length polymorphism(RFLP),nested PCR was employed in combination with TD-PCR to amplify the gene and EcoRI and Hind Ⅲ were used to generate the RFLP fingerprinting.Target DNA fragments from 13 of 20 samples were successfully amplified and the relevant RFLP fingerprintings were obtained.It is concluded that the method can be used to amplify the whole CagA gene and CagA gene has apparent diversity of RFLP profile.     

In vitro Recombination and Identification of Mutated Fragment Corresponding to Regulation Region of mtrR Gene of Neisseria Gonorrhoeae

A site-directed mutant DNA fragment was synthesized and transfected into clinical Neisseria Gonorrhoeae(NG) stains to construct the transformants that contained the corresponding mutagenesis of regulation region of mtrR gene.According to the technique of gene splicing by overlap extension(SOEing),a DNA segment with specific mutagenesis was constructed by two-step polymerase chain reaction(PCR).The mutation fragments EF could be used for the next experiment in which the mutation NG strains were induced.By comparing the recombinant EF fragments to the corresponding DNA fragments of clinical NG strains,2 of these were not compatible completely.The results of sequencing revealed that there was a 9 bp deletion between the 45 to 54 inverted repeat sequence localized within the mtrR promoter.It can be confirmed that the fragments EF are the specifically designed mutant fragments.     

Oral immunization of mice with attenuated Salmonella typhimurium expressing Helicobacter pylori urease B subunit

Objective To establish attenuated Salmonella typhimurium producing Helicobacter pylori (H. pylori) urease subunit B （UreB） and determine whether it could be used as an oral vaccine against H. pylori. Methods H. pylori (SS1 strain) UreB gene fragment amplified by PCR was cloned into the prokaryotic expression vector pTC01 after sequencing, and then transformed into attenuated Salmonella typhimurium SL3261 to acquire SL3261/pTC01- UreB. The expression of H. pylori UreB in SL3261 was detected by Western blot. Twelve weeks after oral immunization of mice,antibody responses were evaluated using serum and intestinal fluid by ELISA assay. Interferon- γ （IFN- γ） and interleukin- 10 （IL- 10） in the supernatant of spleen cells culture were also assessed by ELISA. In vitro stability of pTC01- UreB plasmid in SL3261 was confirmed by growing in Luria Broth (LB) medium to 80 generations.Results The UreB gene fragment amplified by PCR was consistent with the sequence of the H. pylori UreB as evidenced by sequence analysis. Enzyme digestion revealed that the correct pTC01- UreB was obtained. Western blot showed that a 61kDa protein was expressed in SL3261/pTC01- UreB, which could be recognized by anti- H. pylori UreB antiserum. After 80 generations of continuous culture, the recombinant plasmid pTC01- UreB was stable in SL3261 and had no obvious toxicity. Multiple oral immunizations with SL3261/pTC01- UreB could significantly induce H. pylori- specific mucosal IgA response as well as serum IgG response. Moreover, there were significant increases of IFN- γand IL- 10 in the SL3261/pTC01- UreB group. Finally, no obvious side effects for mice and no change in gastric inflammation were observed.Conclusion Attenuated Salmonella typhimurium expressing H. pylori UreB may be used as oral vaccine against H. pylori infection.     

Mitochondrial gene mutations and type 2 diabetes in Chinese families

Background Numerous mitochondrial DNA mutations are significantly correlated with development of diabetes. This study investigated mitochondrial gene, point mutations in patients with type 2 diabetes and their families.
Methods Unrelated patients with type 2 diabetes （n=826） were randomly recruited; unrelated and nondiabetic subjects （n=637） served as controls. The clinical and biochemical data of the participants were collected. Total genome was extracted from peripheral leucocytes. Polymerase chain reaction, restriction fragment length poiymorphism （PCR-RFLP） and cloning techniques were used to screen mitochondrial genes including np3316, np3394 and np3426 in the ND1 region and np3243 in the tRNA^Leu（UUR）.
Results In 39 diabetics with one or more mitochondrial gene point mutations, the prevalence （4.7%, 39/826） of mtDNA mutations was higher than that （0.7%, 5/637） in the controls. The identical mutation was found in 23 of 43 tested members from three pedigrees. Affected family members presented with variable clinical features ranging from normal glucose tolerance to impaired glucose tolerance （IGT） （n=2）, impaired fasting glucose （IFG） （n=1） to type 2 diabetes （n=13） with 3 family members suffering from hearing loss.
Conclusions Type 2 diabetes in China is associated with several mitochondrial gene mutations. Aged patients with diabetic family history had a higher prevalence of mutation and various clinical pictures. Mitochondrial gene mutation might be one of the genetic factors contributing to diabetic familial clustering.     

Demographic and endoscopic characteristics of patients with Helicobacter pylori positive and negative peptic ulcer disease

OBJECTIVE: To identify demographic and endoscopic characteristics of patients with Helicobacter pylori positive and negative chronic peptic ulcer disease. DESIGN: Cross-sectional study of peptic ulcer disease in prospectively recruited PATIENTS undergoing gastroscopy. PATIENTS: 277 consecutive patients referred for gastroscopy in 1996-1998. MAIN OUTCOME MEASURES: Rapid urease test, culture and histological examination for H. pylori infection; anti-H. pylori IgG antibodies in serum; demographic data, intake of non-steroidal anti-inflammatory drugs (NSAIDs) in the preceding 3 months, and size, number and location of ulcers. RESULTS: 54 patients (19%) had evidence of peptic ulcer disease (34 gastric ulcer, 14 duodenal ulcer and 6 both gastric and duodenal ulcer); 45 had active chronic peptic ulcer disease and were analysed in detail. H. pylori was present in 25 (56%) of these patients; 10 (22%) had used NSAIDs and 7 of the NSAID group also had H. pylori infection. Of the patients with gastric ulcers, those with non-H. pylori, non-NSAID ulcers were significantly younger than both those with H. pylori-associated ulcers (mean age, 48 v. 65 years, P = 0.02) and those with NSAID-associated ulcers (mean age, 48 v 68 years, P = 0.02). The average size and number of gastric ulcers did not differ between patients with and without H. pylori infection. Of patients with duodenal ulcers, those with H. pylori infection had significantly fewer ulcers (1.1 v. 1.8, P = 0.04), although ulcer size was similar in the infected and uninfected groups. CONCLUSIONS: Gastric ulcers may now be more common than duodenal ulcers. Gastric ulcers associated with H. pylori infection and/or NSAID use occurred mostly in older people, while non-H. pylori, non-NSAID gastric ulcers were more common in younger patients. In the duodenum, single ulcers were associated with H. pylori infection, and multiple ulcers were more frequent in the non-H. pylori, non-NSAID group.     

IL-1RN基因多态性与消化性溃疡发病相关性及机制分析

目的:探讨白细胞介素-1受体拮抗剂（IL-1RN）基因多态性与消化性溃疡的相关性。方法:选取2016年1月-2018年1月在我院治疗的消化性溃疡患者180例,其中十二指肠溃疡患者91例（十二指肠溃疡组）,胃溃疡患者89例（胃溃疡组）,同时选取健康志愿者270例作为对照组,检查IL-1RN基因多态性,采用快速尿素酶测定幽门螺旋杆菌感染情况。结果:十二指肠溃疡组IL-1RN基因型L/2+2/2比例和等位基因2比例分别为50.55%和29.67%,明显高于胃溃疡组和对照组（P＜0.05）;十二指肠溃疡组幽门螺旋杆菌阳性者IL-1RN基因型L/2+2/2比例和等位基因2比例分别为50.15%和29.38%,明显高于胃溃疡组和对照组（P＜0.05）;胃溃疡组幽门螺旋杆菌阴性者IL-1RN基因型L/2+2/2比例和等位基因2比例分别为62.50%和37.50%,明显高于对照组（P＜0.05）;十二指肠溃疡幽门螺旋杆菌阴性者等位基因2比例为31.82%,明显高于对照组（P＜0.05）;十二指肠溃疡组、胃溃疡组不同IL-1RN基因型患者治疗痊愈率比较差异无统计学意义（P＞0.05）。结论:IL-1RN基因多态性可能与十二指肠溃疡发病有一定的关系,值得进一步研究。     

Helicobacter pylori and peptic ulcer disease in Sri Lanka.

The variation in the healing and the relapse rates of peptic ulcer disease has led to the search for other factors in the pathogensis of peptic ulcer disease. Helicobacter pylori is believed to be responsible for these different patterns of healing. The results of a study to detect Helicobacter pylori in Sri Lankan patients having duodenal ulcer, gastric ulcer, gastritis and non-ulcer dyspepsia are presented in this paper. The method employed was the urease test which detects the urease enzyme of H. pylori in gastric mucosal biopsies taken during upper gastrointestinal endoscopy. There is a high incidence in those with gastritis and duodenitis.     

幽门螺杆菌阳性的十二指肠溃疡病人胃窦炎症程度和炎症因子的 …

目的 研究幽门螺杆菌（ｈｅｌｉｃｏｂａｃｔｅｒｐｙｌｏｒｉ,Ｈｐ）致十二指肠溃疡时胃窦炎症和炎症因子的作用。方法 选择４８例有不同程度Ｈｐ感染的十二指肠溃疡病人,用组织学方法评定胃窦炎症程度,同时测定胃粘膜内白细胞介素６（ＩＬ－６）白细胞介素８（ＩＬ－８）肿瘤坏死因子α（ＴＮＦα）过氧化物酶（ＭＰＯ）和丙二醛（ＭＤＡ）的含量,结果 ＩＬ－８,ＴＮＦα,ＭＰＯ,ＭＤＡ的含量均与胃窦粘膜的炎症程度和Ｈ     

幽门螺杆菌cagA基因片段原核表达载体的构建及其cagA基因和CagA蛋白及感染者血清抗体的检测

目的:构建幽门螺杆菌(Helicobacter pylori,Hp)cagA基因片段的原核表达系统,建立ELISA检测CagA及其抗体,了解表达CagA的Hp菌株(CagA Hp)感染与所致疾病种类的关系.方法:从快速尿素酶试验阳性的156例患者胃黏膜活检标本中分离Hp.采用PCR检测109株Hp cagA基因,并从临床菌株Y06中扩增2 148 bp的cagA基因片段(cagA1).构建cagA1原核表达系统,用SDS-PAGE检查目的重组蛋白(rCagA1)的表达情况,用Western blot和免疫双扩散试验鉴定rCagA1的免疫反应性和抗原性.建立ELISA,检测109株Hp CagA表达和相应患者血清中CagA抗体.分析CagA Hp感染与胃炎和消化性溃疡的关系.结果:80.8%胃黏膜活检标本中分离出Hp(126/156),97.2%的Hp菌株(106/109)cagA基因阳性.与文献报道比较,所克隆的cagA1片段核苷酸和氨基酸序列同源性分别为94.83%和93.30%.所构建的原核表达系统表达的rCagA1量约为细菌总蛋白的30.0%.rCagA1能与Hp全菌抗体发生结合反应,免疫家兔产生双扩散效价为1∶4的抗体.92.6%菌株(101/109)可表达CagA,88.1% 患者(96/109)血清CagA抗体阳性.消化性溃疡标本中CagA Hp菌株分离阳性率(97.9%)高于胃炎标本(88.5%),但无统计学差异(χ2=3.48,P>0.05).结论:本实验构建的原核表达系统表达的rCagA1有良好的免疫反应性和抗原性,建立的ELISA可用于Hp CagA及其抗体的检测,分离的Hp菌株cagA基因携带率和CagA表达率均很高.消化性溃疡和胃炎与其感染的Hp是否表达CagA无明显关系.     

Indications for treatment of Helicobacter pylori infection: a systematic overview.

OBJECTIVE: To determine (a) the advantages and disadvantages of treatment options for the eradication of Helicobacter pylori and (b) whether eradication of H. pylori is indicated in patients with duodenal ulcer, nonucler dyspepsia and gastric cancer. DATA SOURCES: A MEDLINE search for articles published in English between January 1983 and December 1992 with the use of MeSH terms Helicobacter pylori (called Campylobacter pylori before 1990) and duodenal ulcer, gastric cancer, dyspepsia and clinical trial. Six journals and Current Contents were searched manually for pertinent articles published in that time frame. STUDY SELECTION: For duodenal ulcer the search was limited to studies involving adults, studies of H. pylori eradication and randomized clinical trials comparing anti-H. pylori therapy with conventional ulcer treatment. For nonulcer dyspepsia with H. pylori infection the search was limited to placebo-controlled randomized clinical trials. DATA EXTRACTION: The quality of each study was rated independently on a four-point scale by each author. For the studies of duodenal ulcer the outcome measures assessed were acute ulcer healing and time required for healing, H. pylori eradication and ulcer relapse. For the studies of nonulcer dyspepsia with H. pylori infection the authors assessed H. pylori eradication, the symptoms used as outcome measures and whether validated outcome measures had been used. DATA SYNTHESIS: Eight trials involving duodenal ulcer met our inclusion criteria: five were considered high quality, two were of reasonable quality, and one was weak. Six trials involving nonulcer dyspepsia met the criteria, but all were rated as weak. Among treatment options triple therapy with a bismuth compound, metronidazole and either amoxicillin or tetracycline achieved the highest eradication rates (73% to 94%). Results concerning treatment indications for duodenal ulcer were consistent among all of the studies: when anti-H. pylori therapy was added to conventional ulcer treatment acute ulcers healed more rapidly. Ulcer relapse rates were dramatically reduced after H. pylori eradication. All of the studies involving nonulcer dyspepsia assessed clearance rather than eradication of H. pylori. No study used validated outcome measures. A consistent decrease in symptom severity was no more prevalent in patients in whom the organism had been cleared than in those taking a placebo. Of the studies concerning gastric cancer none investigated the effect of eradication of H. pylori on subsequent risk of gastric cancer. CONCLUSIONS: There is sufficient evidence to support the use of anti-H. pylori therapy in patients with duodenal ulcers who have H. pylori infection, triple therapy achieving the best results. There is no current evidence to support such therapy for nonulcer dyspepsia in patients with H. pylori infection. Much more attention must be paid to the design of nonulcer dyspepsia studies. Also, studies are needed to determine whether H. pylori eradication in patients with gastritis will prevent gastric cancer.     

十二指肠溃疡患者胃上皮化生与幽门螺杆菌关系的研究

目的 研究十二指肠溃疡患者胃上皮化生和幽门螺杆菌的关系。方法 收集门诊行上消化道胃镜检查确诊的十二指肠溃疡患者70例，另选胃和十二指肠黏膜正常患者55例为对照组。用快速尿素酶法和幽门活组织检查半定量法检测幽门螺杆菌(Hp)，苏木素一伊红染色和Schiff过碘酸染色半定量法检测十二指肠球部胃上皮化生。结果 十二指肠溃疡患者与对照组相比，十二指肠球部胃上皮化生检出率高；十二指肠球部胃上皮化生检出率和评分与胃幽门部Hp的检出率和评分无相关关系。结论 Hp不是十二指肠黏膜胃上皮化生的决定因素，也不是十二指肠黏膜胃上皮化生范围得以扩展的因素。十二指肠溃疡病本身的一些特点是十二指肠黏膜胃上皮化生的主要因素。     

cagE在胃肠疾病患者中的分布及其临床意义

目的：研究cagE在幽门螺杆菌（Helicobacter pylori,Hp）感染的不同胃肠疾病患者听 分布及其与Hp感染相关疾病的关系。方法：合成cagEU1-cagEU2和cagE3-cagE4两组引物，应用聚合酶链反应（PCR）法扩增145株临床分离培养的Hp菌株cagE片段，结果：Hp临床菌株的cagEU1-cagEU2 PCR产物总检出率为75.9%（110／145），慢性胃炎、十二指肠溃疡、胃溃疡、复合溃疡中检出率分别为69.4%、85.4%、76.5%、75.0%，溃疡组略高于胃炎组，但差异无显著性（P＞0.05）。cagE3-cagE4总检出率为42.1%（61／145），慢性胃炎、十二指肠溃疡、胃溃疡、复合溃疡中检出率分别为38.9%，47.9%，35.3%，50％，差异无显著性（P＞0.05）；cagE总检出率为79.3%（115／145）。结论：cagE在不同的消化道疾病患者感染的Hp中均有较高的检出率，在不同疾病中的分布无特异性，cagE尚不能单独作为与某种疾病相关的致病相关基因。     

反流性食管炎与幽门螺杆菌的相关性研究

目的 研究反流性食管炎(RE)与幽门螺杆菌(H.pylori)感染的相关性。方法 检测RE、正常对照、慢性胃炎和十二指肠溃疡组及各级RE患者的H.pylori感染率。选取40例内镜分级B或C级的RE患者，H.pylori阳性及阴性各20例，雷贝拉唑治疗4周后内镜复查，比较治疗效果。结果 RE组、正常组、慢性胃炎组、十二指肠溃疡组的H.pylori感染率分别为30．4％、28．8％、59．0％、91．5％，RE组感染率显著低于胃炎组和溃疡组，与正常人群无明显差异；各级RE患者的H.pylori感染率无明显差异；RE患者经雷贝拉唑治疗后，H.pylori阳性组与阴性组的病变愈合和症状改善情况无明显差异。结论 RE与H.pylori感染可能无相关性。     

幽门螺杆菌国内流行株动物模型的建立

目的建立国内幽门螺杆菌（Hp）流行株的动物模型,研究Hp流行株感染小鼠的胃黏膜改变,为进一步治疗提供更好的动物模型。方法60只SPF级C57BL/6小鼠,分为正常组和模型组,每组30只。模型组经口灌服VacAs1、CagA、iceA阳性的临床分离株,距末次灌胃后5、10、15、20、25、30周分6批处死,取标本行快速尿素酶试验,Giemsa染色法观察Hp在胃黏膜上的定植情况,HE染色观察小鼠胃黏膜的病理变化。结果正常组小鼠的胃窦、胃体及十二指肠黏膜的尿素酶试验,Giemsa染色结果均阴性,模型组在距末次灌胃后5、10、15、20、25、30周Hp定植率分别为60%、80%、100%、100%、100%、100%。至30周模型组慢性浅表性胃炎、慢性萎缩性胃炎、肠化、异型增生、胃癌发生率分别为100%、60%、0%、0%、0%。结论成功建立了HpVacAs1、CagA、iceA阳性的国内流行株感染C57BL/6小鼠的模型,并明确了其感染小鼠后各阶段的胃黏膜病理改变。