Evaluation of cell proliferation and apoptosis in <Emphasis Type="Italic">Helicobacter pylori</Emphasis> gastritis using an image analysis processor

Background: Infection of the gastric mucosa by Helicobacter pylori is primarily responsible for gastritis, gastric ulcer, adenocarcinoma, and lymphoproliferative disorders. H. pylori appears to accelerate apoptosis and the proliferation of the gastric epithelium directly or indirectly. To precisely assess the proliferative and apoptotic profile of H. pylori -infected gastric mucosa, a quantitative imaging system is now required. Methods: Fifty-two patients with H. pylori gastritis were the subjects of the study. Biopsy materials were taken from at least two sites (usually three to five sites) including the antrum and corpus. The grade of gastritis was evaluated by the Updated Sydney System. The proliferative and apoptotic profile was examined by Ki-67 immunohistochemistry and by a terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling method. In addition, Ki-67-positive cells were quantitated by an image processor for analytical pathology (IPAP) system. Results: H. pylori density and polymorphonuclear neutrophil activity were significantly decreased after H. pylori eradication ( P < 0.0001). Chronic inflammation ( P < 0.0001) and lymphoid follicle numbers ( P < 0.0005) were also significantly decreased after the eradication. Glandular atrophy and intestinal metaplasia were slightly decreased after eradication, but the decrease did not reach the significant level. The Ki-67 labeling index was significantly decreased after the eradication ( P < 0.0001). The apoptosis index was also decreased after the eradication, but this decrease did not reach the significant level ( P = 0.06). Conclusion: Our data suggest that the activation of proliferative cells and induction of apoptosis in the gastric mucosa is a response to H. pylori -induced mucosal damage. Moreover, IPAP may be a useful technology for evaluating the results of immunohistochemistry, and it could provide quantitative and reliable data for studying H. pylori gastritis. Received: July 22, 2002 / Accepted: October 10, 2002 Acknowledgments This work was supported in part by a grant from Otsuka Pharmaceutical Company (Tokyo, Japan) and by the Japanese Clinical Study Group of esophagocardiac lesion. We would like to thank Dr. Kaoru Hirabayashi for her helpful suggestion and Ms. Chiaki Sato-Matsuyama, Ms. Ayako Shimizu, and Ms. Takako Ohtsuki for their excellent technical assistance. Offprint requests to: T. Fujimori The first two authors contributed equally to this study.     

Altered gastric epithelial cell kinetics in Helicobacter pylori-associated intestinal metaplasia: implications for gastric carcinogenesis

We have compared apoptosis and proliferation in antral epithelium from individuals not infected with H. pylori (Hp), those with Hp-induced gastritis and those with Hp-induced gastritis containing areas of gastric intestinal metaplasia, the precursor lesion to gastric adenocarcinoma. Antral biopsies from 42 patients were assessed for evidence of Hp infection, severity of gastritis and intestinal metaplasia. Apoptosis was evaluated by the TUNEL assay and proliferation by Ki-67 immunohistochemistry and were expressed as apoptotic (AI) and proliferation (PI) indices. In the 31 Hp-positive (Hp(+)) patients, apoptosis and proliferation were increased compared with the 11 Hp-negative (Hp(-)) patients (AI = 1. 22 +/- 0.13% vs. 0.15 +/- 0.03%, p < 0.0001; PI = 24 +/- 1% vs. 13 +/- 2%, p < 0.0001). Increases were proportional to the severity of the inflammation. Within foci of intestinal metaplasia, in 9 of the Hp(+) patients, apoptosis was significantly reduced compared with surrounding gastritis (AI = 0.20 +/- 0.06% vs. 1.34 +/- 0.23%, p = 0. 0014), whereas proliferation was not altered (PI = 25.4 +/- 4% vs. 24.7 +/- 2%, p = 0.87), resulting in a lower AI/PI ratio in intestinal metaplasia than in surrounding gastritis (0.008 +/- 0.005 vs. 0.054 +/- 0.009, p < 0.02). Hp-induced gastritis is thus associated with increased epithelial apoptosis and proliferation compared with uninfected controls. In intestinal metaplasia, proliferation remains increased but apoptosis reverts to normal levels, and this perhaps contributes to Hp-associated gastric carcinogenesis.     

幽门螺旋杆菌感染胃黏膜COX-2和P-gp表达与胃癌发生

背景与目的通过检测幽门螺旋杆菌(Helicobacter Pylori,H.pylori)感染胃粘膜组织环氧合酶-2(Cyclooxygenase-2,COX-2)和多药耐药-1(Multidrug resistance-1,MDR-1)基因表达产物P糖蛋白(P-glycoprotein,P-gp)表达,探讨幽门螺旋杆菌相关胃癌的发生机制,以及P-gp高表达的机制。材料与方法慢性胃炎155例(30例慢性浅表性、40例慢性萎缩性、45例肠化、40例非典型增生)及胃癌80例(肠型40例,弥漫型40例),COX-2和P-gp表达检测选择免疫组化S-P法,H.pylori感染检测采用快速脲素酶及改良Giemsa染色方法。结果H.pylori阳性感染率、COX-2和P-gp的阳性表达率,肠型胃癌均明显高于弥漫型胃癌(P<0.01)。慢性萎缩性胃炎、肠化、非典型增生及肠型胃癌中H.pylori感染与COX-2的表达呈正相关(P<0.01)。H.pylori感染的慢性浅表性胃炎、慢性萎缩性胃炎、肠化、非典型增生及肠型胃癌中COX-2的表达与P-gp的表达也均呈正相关(P<0.01)。结论H.pylori依赖的COX-2表达与P-gp表达有关,可能有助于胃癌形成以及胃癌对化疗抵制。     

良性胃黏膜病变中Hp感染与Livin、Ki-67表达关系的研究

目的：观察Livin和Ki-67在Hp（＋/-）良性胃黏膜病变组织中的表达。方法：所有胃黏膜病变组织均来自内镜活检及手术切除标本,良性胃黏膜病变组织标本144例。采用免疫组化法测定上述胃黏膜病变组织及胃癌组织中Livin、Ki-67的表达,用甲苯胺蓝染色检测Hp。结果：Livin、Ki-67在Hp根治前后从慢性浅表性胃炎、慢性萎缩性胃炎、伴肠化、不典型增生组织中的表达率呈递增趋势,其中在慢性萎缩性胃炎和萎缩伴肠化的阳性表达率有统计学意义（ P〈0.05）。结论：在癌前病变阶段根除Hp可使部分萎缩和肠化减轻,能有效治疗Hp相关性胃炎,也可预防Hp相关性胃癌的发生。     

Re-expression of sonic hedgehog and reduction of CDX2 after Helicobacter pylori eradication prior to incomplete intestinal metaplasia

Loss of Sonic Hedgehog (Shh) and aberrant CDX2 expression are early changes correlating with the presence of intestinal metaplasia that occur in the gastric mucosa prior to neoplastic transformation. The aim of this study was to compare the improvement in corpus gastritis with Shh and CDX2 expression after H. pylori eradication between subjects at high risk for gastric cancer and controls. The usefulness of serum pepsinogen levels as a predictor of resolved corpus gastritis was also examined. Seventy patients with endoscopic resection for early gastric cancer and 30 controls were studied. Expression of Shh and CDX2 were evaluated by immunostaining. Serum levels of pepsinogen I before eradication in the patients scored as having improvement of corpus atrophy were significantly higher than in the patients without improvement (<0.01). Residual inflammation at the corpus lesser curve was more frequently detected in the cancer group than in the controls (OR 4.6 95% C.I. 1.6-13.5) and in the mucosa with incomplete intestinal metaplasia rather than in those without incomplete intestinal metaplasia (OR 7.6 95% C.I. 2.4-24.3). Atrophy, expression of Shh and CDX2 at the corpus lesser curve significantly improved in mucosa without incomplete intestinal metaplasia (p < 0.01), but not in mucosa with incomplete intestinal metaplasia. In conclusion, H. pylori eradication prior to development of incomplete intestinal metaplasia improves corpus gastritis and may prevent gastric cancer. Pepsinogen I may be a useful marker in patients with a residual higher risk of gastric cancer after H. pylori eradication.     

Compartment theory in Helicobacter pylori-associated gastric carcinogenesis

BACKGROUND: The compartment theory has not been well investigated in gastric carcinogenesis. This study was aimed at examining the compartment alterations through the Helicobacter pylori (H. pylori)-related chronic gastritis-intestinal metaplasia-carcinoma sequence, and investigating the long-term effect of bacterial eradication on the compartment changes. PATIENTS AND METHODS: Gastric biopsy specimens were obtained from subjects with H. pylori-negative normal mucosa (N = 12), H. pylori-positive non-metaplastic gastritis (N = 42), H. pylori-positive intestinal metaplasia (N = 21) and intestinal-type adenocarcinoma (N = 20). The specimens were immnostained for monocloncal antibodies against the proliferating cell nuclear antigen (PCNA) for proliferating analysis. Additionally, 50 patients with H. pylori-positive gastritis were enrolled to investigate the long-term effect of bacterial eradication on the compartment changes of gastric epithelium. RESULTS: The mean PCNA labeling indices (L.I.) of non-metaplastic gastritis, intestinal metaplasia and adenocarcinoma were significantly higher than that of normal mucosa (31.1, 49.2 and 40.7 vs. 21.4; p < 0.01, 0.001 and 0.001, respectively). The proliferating zone was principally located in the lower compartment of normal mucosa. In patients with intestinal metaplasia, there was a full expansion (phase 1 change) of proliferating zone to the middle compartment of gastric pits (ratio of L.I. between middle and lower compartment = 1.00). The proliferating cells were evenly distributed in adenocarcinoma (complete loss of compartmentalization). Eradiation of H. pylori led to a reversion of compartment changes of gastric epithelium in patients with chronic gastritis. CONCLUSION: H. pylori-related gastric carcinogenesis is a multistep process involving progressive alterations of proliferating activity as well as loss of compartmentalization. Eradication of H. pylori reverses the changes in growth kinetics of gastric epithelium.     

Gastric mucosal proliferative and total tyrosine kinases activities increase in Helicobacter pylori-induced chronic gastritis

Background. The intestinal type of gastric cancer is thought to originate from cancer precursor lesions, progressing from H. pylori-induced chronic gastritis, atrophic gastritis, to intestinal metaplasia (IM) and dysplasia. Tyrosine kinases (tyr-k) represent the family of proteins that are widely expressed during cell metabolism and are considered as secondary markers for cellular proliferation and malignant transformation. Aim of Study. The aim of the study was to evaluate the correlation between gastric mucosal histopathologic changes, total tyrosine kinases, and proliferative activities in patients with H. pylori infection. Methods. Biopsy specimens from the gastric mucosa of 94 patients were assessed for H. pylori infection, histopathology (according to the Sydney classification), proliferative activity [Ki-67 immunohistochemistry with labeling index (LI) estimation], and total tyr-k activities (ELISA assay kit). Results. Total tyr-k activities and Ki-67 LI were significantly higher in H. pylori (+) than H. pylori (?) group (728.1±175.3 vs 360.1±44.4 pmol P/mg/min. p<0,01 and 20,0±5.8 vs 10.9±1.3 %, respectively). A significant correlation has been observed between the Ki-67 LI and total tyr-k activities in patients with and without H. pylori infection. In cases of gastritis accompanied with atrophic changes or intestinal metaplasia in H. pylori (+) patients, Ki-67 LI and total tyr-k activities were particularly high compared to chronic gastritis without atrophy or intestinal metaplasia. Conclusion. Those results suggest that tyrosine kinases may play an important role in the development of gastric mucosal hyperproliferation in H. pylori-induced gastritis and possibly in early phase of gastric carcinogenesis.     

P504S、Ki-67对老年胃癌的早期诊断价值及与幽门螺旋杆菌的相关性研究

目的:探讨分析P504S、Ki-67在老年人群中萎缩性胃炎、低级别上皮内瘤变、高级别上皮内瘤变、早期胃癌中的表达情况及其与幽门螺旋杆菌感染的相关性。方法:应用免疫组化法检测2018年3月至2019年3月陕西省人民医院胃镜活检标本157例（其中包括43例慢性萎缩性胃炎伴肠上皮化生、42例低级别上皮内瘤变、39例高级别上皮内瘤变及33例高分化腺癌）标本中P504S、Ki-67的表达情况及HP感染情况。结果:在慢性萎缩性胃炎伴肠化、低级别上皮内瘤变、高级别上皮内瘤变及高分化腺癌标本中,P504S、Ki-67 的表达呈逐渐增高的趋势,并且与HP感染与否没有显著相关性。结论:P504S和Ki-67在胃的癌前病变及早期胃癌中的表达与疾病的发生、发展具有一定的相关性,可以作为老年人群胃癌癌前病变及早期胃癌的辅助诊断手段,且与HP感染不具相关性。     

Apoptosis in Gastric Carcinomas and Its Association with Cell Proliferation and Differentiation

The significance of apoptosis in human gastric carcinomas was investigated in comparison with proliferative activity and p53 accumulation, using an in situ DNA nick end labeling method and immunohistochemistry for both Ki-67 antigen and p53 protein. Apoptotic labeling indices (LI) of 51 differentiated carcinomas (21 of early and 22 of advanced stage) were significantly lower than for 33 undifferentiated tumors (9 of early and 24 of advanced stage) ( P <0.05). In both types, apoptotic LI of advanced stage lesions were significantly higher than for the early stage cases ( P <0.005, P <0.03). The distribution of apoptotic cells was different from that of Ki-67-positive cells, generally exhibiting an inverse correlation for areas of predominance. In contrast, there was no significant correlation between p53 immunoreactivity and either apoptotic LI or Ki-67 LI. It is concluded that in human gastric carcinomas the susceptibility to apoptosis is related to tumor cell differentiation and depth of invasion, and may play a role in selection of clonal subpopulations with high growth potential.     

High Prevalence of Helicobacter pylori Resistance to Clarithromycin: a Hospital-Based Cross-Sectional Study in Nakhon Ratchasima Province,Northeast of Thailand

Background: Helicobacter pylori is a cause of chronic gastritis, peptic ulcer disease, and gastric malignancy, infection being a serious health problem in Thailand. Recently, clarithromycin resistant H. pylori strains represent the main cause of treatment failure. Therefore this study aimed to determine the prevalence and pattern of H. pylori resistance to clarithromycin in Suranaree University of Technology Hospital, Suranree University of Technology, Nakhon Ratchasima, Northeastern Thailand, Nakhon Ratchasima province, northeast of Thailand. Materials and Methods: This hospital-based cross-sectional study was carried out between June 2014 and February 2015 with 300 infected patients interviewed and from whom gastric mucosa specimens were collected and proven positive by histology. The gastric mucosa specimens were tested for H. pylori and clarithromycin resistance by 23S ribosomal RNA point mutations analysis using real-time polymerase chain reactions. Correlation of eradication rates with patterns of mutation were analyzed by chi-square test. Results: Of 300 infected patients, the majority were aged between 47-61 years (31.6%), female (52.3%), with monthly income between 10,000-15,000 Baht (57%), and had a history of alcohol drinking (59.3%). Patient symptoms were abdominal pain (48.6%), followed by iron deficiency anemia (35.3%). Papaya salad consumption (40.3%) was a possible risk factor for H. pylori infection. The prevalence of H. pylori strains resistant to clarithromycin was 76.2%. Among clarithromycin-resistant strains tested, all were due to the A2144G point mutation in the 23S rRNA gene. Among mutations group, wild type genotype, mutant strain mixed wild type and mutant genotype were 23.8%, 35.7% and 40.5% respectively. With the clarithromycin-based triple therapy regimen, the efficacy decreased by 70% for H. pylori eradication (P<0.01). Conclusions: Recent results indicate a high rate of H. pylori resistance to clarithromycin. Mixed of wild type and mutant genotype is the most common mutant genotype in Nakhon Ratchasima province, therefore the use of clarithromycin-based triple therapy an not advisable as an empiric first-line regimen for H. pylori eradication in northeast region of Thailand.     

Study of p53 immunostaining in the gastric epithelium of cagA-positive and cagA-negative Helicobacter pylori gastritis

BACKGROUND: p53 mutations are an early event in the multistep progression of gastric carcinoma. These mutations are often present in dysplastic and intestinal metaplastic gastric epithelium. However, the presence of immunohistochemically detectable p53 protein and p53 mutations in nondysplastic/nonmetaplastic gastric mucosa is more controversial. Recent reports have suggested that immunohistochemically detectable p53 protein may be present in the gastric epithelium of Helicobacter pylori gastritis. Furthermore, because cagA-positive H. pylori is associated with greater mucosal injury but decreased apoptosis, it would be interesting to determine if this phenotype is associated with greater immunostaining of p53, as the wild-type p53 gene helps to initiate apoptosis. METHODS: One hundred thirty-five patients with H. pylori-associated gastritis were immunohistochemically stained for p53 and quantified for the extent and intensity of the staining using a semiquantitative method (0, nil staining; 6, extensive and strong staining). The cagA status of the organism was determined by Western blot. RESULTS: Thirty-one patients (23%) showed strong p53 staining (> or = 4 of 6) in inflamed but otherwise normal gastric epithelium. In the 123 cagA-positive H. pylori gastritis patients, the average p53 staining score was 2.5 of 6. This is significantly higher than the corresponding score of 1.7 of 6 observed in the 12 patients with cagA-negative H. pylori gastritis (P = 0.04). CONCLUSIONS: Our results indicate that p53 protein is immunohistochemically detectable even before gastric metaplastic/dysplastic change occurs. The results also suggest that cagA-positive H. pylori might be associated with greater p53 immunohistochemical staining. This would indicate that p53 immunohistochemical staining does not reliably differentiate between gastric dysplasia and reactive inflammatory atypia. If the p53 protein detected is a consequence of mutation, this would help to explain why cagA-positive H. pylori gastritis is associated with decreased apoptosis.     

癌前病变Caspase-3表达下调与胃黏膜癌变的关联

目的观察Caspase-3蛋白在胃癌及其癌前病变组织中的表达,分析它与细胞凋亡和细胞增殖的关系,探讨Caspase-3蛋白在胃癌发生过程中的生物学意义及相关分子病理学机制。方法选取184例胃黏膜活检和手术切除组织标本,其中胃癌20例,慢性萎缩性胃炎6例,萎缩性胃炎伴肠上皮化生(简称肠上皮化生)31例,萎缩性胃炎伴不典型增生(简称不典型增生)114例;正常对照13 例。采用SABC法检测Caspase-3蛋白的表达;通过图像域值分析计算其阳性指数,分析其与细胞增殖(Ki67蛋白阳性指数)和凋亡(TUNEL指数)的相关关系。结果 Caspase-3蛋白在重度不典型增生组织中的阳性指数(29．8％±3．9％)显著低于轻度(58．3％±4．2％)和中度不典型增生(50．4％± 4．8％)及萎缩性胃炎(68．3％±3．3％)或肠上皮化生(70．9％±4．3％),差异有统计学意义(P<0．05); 而与胃癌(26．9％±3．0％)相比,差异无统计学意义(P>0．05)。Caspase-3蛋白表达与细胞凋亡呈显著正相关(r=0．94,P<0．05),Caspase-3蛋白阳性组细胞增殖指数(18．3％±2．2％)显著低于阴性组(48．9％±3．1％;P<0．05)。结论 Caspase-3蛋白在萎缩性胃炎、肠上皮化生和(或)轻中度不典型增生黏膜中表达上调,而在重度不典型增生及胃癌组织中表达下调,且这种变化与细胞凋亡呈显著正相关。Caspase-3失活或表达下调相关的细胞凋亡和增殖紊乱可能在胃黏膜损伤及癌变过程中起某种作用。     

Eradication of Helicobacter pylori restores glutathione S-transferase activity and glutathione levels in antral mucosa.

Glutathione S-transferases (GST) and glutathione peroxidases (GPO) are important in detoxification. GST activity in the mucosa of the gastrointestinal tract is inversely correlated with the development of gastrointestinal cancer. Helicobacter pylori (H. pylori) infection has been associated with gastric cancer. We studied GST activity and the substrate glutathione (GSH) in patients with H. pylori-associated gastritis. GST activity and isoenzyme levels, GPO activity and GSH levels were studied in antral biopsies of 38 H. pylori-positive patients, before and after eradication treatment. In 31 patients in whom H. pylori was successfully eradicated, antral GST enzyme activity before therapy was 532 (465 - 598) nmol / mg protein. min (mean and 95% confidence interval) and that after therapy was 759 (682 - 836) nmol / mg protein. min (P < 0.0001). Correspondingly, levels of GST alpha and GST-P1 were higher after eradication (P < 0.001). GSH concentration significantly increased: 21.2 (16.2 - 26.2) nmol / mg protein before and 27.1 (23.6 - 30.6) nmol / mg protein after therapy (P < 0.05). In 7 patients in whom H. pylori was not eradicated, GST activity was 671 (520 - 823) nmol / mg protein. min and 599 (348 - 850) nmol / mg protein before and after treatment respectively (P = 0.32). GSH levels were 17.4 (9.0 - 25.7) nmol / mg protein and 18.2 (9.1 - 27.3) nmol / mg protein, respectively (P = 0.84). No differences in antral GPO enzyme activity, both of selenium (Se)-dependent and total GPO, before and after successful treatment were found. Eradication of H. pylori infection increases GST activity and GSH levels in antral mucosa. Low GST activity and GSH concentration due to H. pylori infection might play a role in gastric carcinogenesis.     

Eradication of Helicobacter pylori Restores Glutathione S-Transferase Activity and Glutathione Levels in Antral Mucosa

Glutathione S-transferases (GST) and glutathione peroxidases (GPO) are important in detoxification. GST activity in the mucosa of the gastrointestinal tract is inversely correlated with the development of gastrointestinal cancer. Helicobacter pylori (H. pylori) infection has been associated with gastric cancer. We studied GST activity and the substrate glutathione (GSH) in patients with H. pylori-associated gastritis. GST activity and isoenzyme levels, GPO activity and GSH levels were studied in antral biopsies of 38 H. /pyfori-positive patients, before and after eradication treatment. In 31 patients in whom H. pylori was successfully eradicated, antral GST enzyme activity before therapy was 532 (465–598) nmol/mg protein-min (mean and 95% confidence interval) and that after therapy was 759 (682–836) nmol/mg protein-min ( P <0.0001). Correspondingly, levels of GST α and GST-P1 were higher after eradication ( P <0.001). GSH concentration significantly increased: 21.2 (16.2–26.2) nmol/mg protein before and 27.1 (23.6–30.6) nmol/mg protein after therapy ( P <0.05). In 7 patients in whom H. pylori was not eradicated, GST activity was 671 (520–823) nmol/mg protein min and 599 (348–850) nmol/mg protein before and after treatment respectively ( P =0.32). GSH levels were 17.4 (9.0–25.7) nmol/mg protein and 18.2 (9.1–27.3) nmol/mg protein, respectively ( P =0.84). No differences in antral GPO enzyme activity, both of selenium (Se)-dependent and total GPO, before and after successful treatment were found. Eradication of H. pylori infection increases GST activity and GSH levels in antral mucosa. Low GST activity and GSH concentration due to H. pylori infection might play a role in gastric carcinogenesis.     

Eradication of Helicobacter pylori induces apoptosis and inhibits proliferation of heterotopic proliferative glands in infected Mongolian gerbils

Mongolian gerbils infected with Helicobacter pylori (H. pylori ) develop heterotopic proliferative glands (HPGs) in the glandular stomach submucosa. To investigate the effects of H. pylori eradication on cell turnover in HPGs, three antibiotics, lansoprazole, amoxicillin and clarithromycin, were administered at 50 or 75 weeks after inoculation of H. pylori, and the stomachs were excised for histological examination at 1, 2, 4, 8 or 25 weeks thereafter. The HPGs were classified into gastric type (G-type) and others (GI + I-type), which included both pure intestinal (I-type) and gastric-and-intestinal mixed type (GI-type). Apoptosis and cell proliferation were evaluated by means of TUNEL assay and BrdU labeling, respectively. At 8 weeks post-eradication, apoptotic indices were significantly increased in the eradication group (G-type: 2.5%; GI + I-type: 7.2%) compared to the non-eradication group (G-type: 0.6%; GI + I-type: 2.1%: P < 0.01), while BrdU labeling indices were significantly decreased (G-type: 1.9%; GI + I-type: 6.8% as compared with 4.3% and 13.2%, respectively, P < 0.01 for both). At 25 weeks, the apoptotic indices were similarly higher [G-type: 0.4 (eradication group) vs. 0.2% (non-eradication group); GI + I-type: 5.8 vs. 1.1%, both P < 0.01], and the BrdU labeling indices (G-type: 0.8 vs. 2.2%, P < 0.01; GI + I-type: 5.1 vs. 11%, P < 0.05) continued to be lower in HPGs. Furthermore, there were highly significant reductions in the areas of HPGs at 8 and 25 weeks post-eradication. These findings demonstrated that eradication results in apoptosis and reduction of proliferation of HPGs in H. pylori-infected gerbils, these lesions thus being apparently reversible through regulation of cell kinetics.     

Levels of malondialdehyde-deoxyguanosine in the gastric mucosa: relationship with lipid peroxidation, ascorbic acid, and Helicobacter pylori.

Helicobacter pylori infection is associated with elevated gastric mucosal concentrations of the lipid peroxidation product malondialdehyde and reduced gastric juice vitamin C concentrations. Malondialdehyde can react with DNA bases to form the mutagenic adduct malondialdehyde-deoxyguanosine (M(1)-dG). We aimed to determine gastric mucosal levels of M(1)-dG in relation to H. pylori infection and malondialdehyde and vitamin C concentrations. Patients (n = 124) attending for endoscopy were studied. Levels of antral mucosal M(1)-dG were determined using a sensitive immunoslot-blot technique; antral mucosal malondialdehyde was determined by thiobarbituric acid extraction, and gastric juice and antral mucosal ascorbic acid and total vitamin C were determined by high-performance liquid chromatography. Sixty-four H. pylori-positive patients received eradication therapy, and endoscopy was repeated at 6 and 12 months. Levels of M(1)-dG did not differ between subjects with H. pylori gastritis (n = 85) and those with normal mucosa without H. pylori infection (n = 39; 56.6 versus 60.1 adducts/10(8) bases) and were unaffected by age or smoking habits. Malondialdehyde levels were higher (123.7 versus 82.5 pmol/g; P < 0.001), gastric juice ascorbic acid was lower (5.7 versus 15.0 micromol/ml; P < 0.001), and antral mucosal ascorbic acid was unchanged (48.0 versus 42.7 micromol/g) in H. pylori gastritis compared with normal mucosa. Multiple regression analysis revealed that M(1)-dG increased significantly with increasing levels of malondialdehyde, antral ascorbic acid, and total antral vitamin C. M(1)-dG levels were unchanged 6 months (63.3 versus 87.0 adducts/10(8) bases; P = 0.24; n = 38) and 12 months (66.7 versus 77.5 adducts/10(8) bases; P = 0.8; n = 13) after successful eradication of H. pylori. M(1)-dG thus is detectable in gastric mucosa, but is not affected directly by H. pylori.     

Serum 8 Hydroxydeoxyguanosine and Cytotoxin Associated Gene A as Markers for Helicobacter pylori Infection

Background: Helicobacter pylori (H.pylori) is associated with chronic gastritis, peptic ulcers, gastricadenocarcinomas and mucosa associated tissue lymphomas. Cytotoxin associated gene A (CagA) is one of thevirulence factors of H.pylori. It is hypothesized that reactive oxygen species (ROS) play roles in H.pylori associateddisease especially in development of gastric adenocarcinoma. Individuals infected with H.pylori bearing CagAproduce more ROS than others. 8-hydroxydeoxyguanosine (8OHdG) is an in vitro marker of DNA damage andoxidative stress. The aim of this study was to investigate the relationship between 8OHdG level, H.pylori infectionand CagA and alterations of serum 8OHdG level after H.pylori eradication. Materials and Methods: Patientsadmitted with dyspeptic complaints and upper gastrointestinal endoscopy were assessed. H.pylori was determinedfrom histopathology of specimens. Serum 8OHdG levels of three groups (H.pylori negative, H. pylori positiveCagA negative and H.pylori positive CagA positive) were compared. Patients with H.pylori infection receivederadication therapy. Serum 8OHdG levels pretreatment and posttreatment were also compared. Results: Intotal, 129 patients (M/F, 57/72) were enrolled in the study. Serum 8OHdG level of H.pylori negative, H. pyloripositive CagA negative and H.pylori positive CagA positive groups were significantly different (5.77±1.35 ng/ml,5.43±1.14 ng/ml and 7.57±1.25 ng/ml respectively, p=0.05). Furthermore, eradication therapy reduced serum8OHdG level (6.10±1.54 ng/ml vs 5.55±1.23 ng/ml, p=0.05). Conclusions: Individuals infected with H.pyloribearing CagA strains have the highest serum 8OHdG level and eradication therapy decreases the serum 8OHdGlevel. To the best of our knowledge this is the first study that evaluated the effect of CagA virulence factor onserum 8OHdG level and the effect of eradication therapy on serum 8OHdG levels together. Eradication of CagAbearing H.pylori may prevent gastric adenocarcinoma by decreasing ROS. 8OHdG level may thus be a goodmarker for prevention from gastric adenocarcinoma     

幽门螺杆菌感染性胃炎细胞凋亡与bcl-2/bax表达的意义

目的：探讨幽门螺杆菌ＨＰ引起胃粘膜上皮细胞凋亡和增殖发迹及ＨＰ致癌作用的可能机制。方法：采用免疫组织化学方法及脱氧核糖核酸末端转移酶介导的ｄＵＴＰ缺口末端标记（ＴＵＮＥＬ）技术,对ＨＰ阳性和ＨＰ阴性者胃粘膜上皮中增殖细胞,凋亡细胞进行原位观察和比较,同时检测ｂｃ１－２／ｂａｘ蛋白表达状态。结果：ＨＰ阳性者胃粘膜上皮细胞增殖指数和凋亡指数显著高于ＨＰ阴性者（Ｐ〈０．０１）。ｂａｘ蛋白表达阳性率在ＨＰ