胃黏膜癌前病变中p53、p21^ras蛋白表达与幽门螺杆菌感染的关系

目的观察幽门螺杆菌(Helicobacterpylori)感染及根除H.pylori二年后p53、p21ras在二组胃黏膜上皮细胞的表达,探讨H.pylori在胃癌发生、发展中的作用.方法应用免疫组织化学染色、尿素酶快速试验(RUT)、组织学Warthin-Starry染色.198例H.pylori感染患者,慢性胃炎86例,慢性胃炎伴肠化生67例,慢性胃炎伴异型增生45例;对照组为根除H.pylori 2年后共86例,其中慢性胃炎54例,慢性胃炎伴肠化生32例,慢性胃炎伴异型增生10例.全部病例做p53、p21ras免疫组织化学染色.结果 H.pylori感染组p53、p21 ras 阳性表达率15.7%、18.7%,明显高于H.pylori根除组2.3%、7%,差异显著(P＜0.05);慢性胃炎伴肠化病变中,p53、p21ras在H.pylori感染组阳性表达率17.9%、18.4%均高于H.pylori根除组0%、9.4%,差异显著(P＜0.05)慢性胃炎伴异型增生病变中,p53、p21 ras在H.pylori感染组阳性表达率31.1%、40%均高于H.pylori根除组20%、30.4%,差异显著(P＜0.05);H.pylori 感染组p53、p21ras在慢性胃炎,肠化生,异型增生表达水平依次增高p53、p21ras共同表达阳性37例.结论在胃黏膜癌前病变中p53、p21ras 在H.pylori感染组阳性表达率高于H.pylori根除组,差异显著(P＜0.05);在慢性胃炎,肠化生,异型增生p53、p21ras表达水平在增高;p53、p21 ras表达呈正相关;H.pylori感染在胃癌发生、发展过程中起一定作用,p53、p21ras表达可能是H.pylori致癌的作用机理之一.     

幽门螺杆菌感染者胃粘膜癌前病变与Fas抗原表达的关系

目的研究幽门螺杆菌(Hp)感染后胃粘膜癌前病变中 Fas 抗原表达的情况,了解 Hp 在胃癌发生过程中的作用。方法采用免疫组织化学等方法检测83例经病理证实为慢性胃炎病人胃粘膜上皮细胞中 Fas 抗原的表达情况。结果在浅表性胃炎、萎缩性胃炎、肠化生及异型增生中,Fas 抗原表达率分别为20.00%、36.36%、73.33%、43.75%,Fas 抗原在肠化生中的表达率显著高于浅表性胃炎、萎缩性胃炎及异型增生(P<0.01及P<0.05)。Hp 感染者 Fas 抗原表达率为60.71%,显著高于 Hp 阴性者的22.22%(P<0.01)。在萎缩、肠化生及异型增生等癌前病变中,Hp 感染者与未感染者表达率分别为65.96%及28.57%(P<0.01)。结论 Hp 感染对 Fas 抗原表达有一定的影响,Hp 感染可促进 Fas 抗原表达增加,这可能是 Hp 感染诱导胃粘膜上皮细胞凋亡的机制之一。     

Hp相关性胃疾病与胃肠化生、不典型增生的关系

目的探讨Hp感染与肠化生、不典型增生等胃癌前期病变的关系.方法693例胃病患者,分慢性浅表性胃炎(CSG)、慢性萎缩性胃炎(CAG)、胃溃疡(GU)及十二指球部溃疡(DU)等四组,胃镜下观察粘膜病变、溃疡部位及性质,胃镜下取材,常规HE染色后观察组织学改变、Giemsa染色后观察Hp感染程度,统计分析Hp感染与肠化生、不典型增生等的关系.结果四组胃疾病中,Hp感染程度与肠化尘程度差异显著(P＜0.01),DU组的Hp感染率高于其它组(P＜0.01),CAG组的胃肠化生率最高(P＜0.05);Hp阳性标本中,CAG组的胃肠化及不典型增生最高(P＜0.01)Hp阴性标本中,CAG组的胃肠本的胃肠化和不典型增生发生率与Hp阴性标本的发生率有显著差异(P＜0.05).结论Hp与CAG并存时,癌前病变发生率最高,其次为GU;建议在临床上,抗Hp治疗和对CAG、GU的治疗同时进行,并内镜随访.     

Histological changes in the gastric mucosa after Helicobacter pylori eradication

BACKGROUND AND AIM: Correa described a stepwise model of changes in the gastric mucosa after Helicobacter pylori infection, from the normal gastric epithelium to chronic gastritis, atrophy, intestinal metaplasia, dysplasia and adenocarcinoma. The aim of this study is to assess the reversibility of these mucosal changes after H. pylori eradication. METHODS: The study sample consisted of 89 patients who underwent at least two gastric biopsies from 1990 to 2000, with a positive finding for H. pylori in the first and a negative finding in the second. Specimens were evaluated for acute and chronic inflammation, lymphoid aggregates, proliferation, mucosal atrophy, intestinal metaplasia, dysplasia, and MUC5AC and MUC6 expression using histochemical and immunohistochemical methods. RESULTS: The average time between biopsies was 23.15 +/- 26.30 months. There was a significant decrease in acute and chronic inflammation scores, from 1.48 +/- 1.10 to 0.23 +/- 0.63 and from 2.67 +/- 0.68 to 1.44 +/- 1.04, respectively (P < 0.001), and in a number of lymphoid follicles, from 42.68% to 21.95% of cases (P < 0.008). The number of glands increased from 39.08 +/- 16.67/mm to 48.86 +/- 17.93/mm after eradication (P = 0.062). Intestinal metaplasia was found in 17.07% of the cases, with no change over time. Dysplasia appeared in one case 2 years after eradication. In 27 patients, the Ki67 labeling index decreased significantly after eradication, while MUC5AC and MUC6 expression increased. CONCLUSION: Our findings, although not conclusive for arrest of the malignant potential, support the importance of H. pylori eradication in the prevention of gastric cancer.     

Expression of gastric cancer—associated MG7 antigen in gastric cancer,precancerous lesions and H.pylori—associated gastric diseases

AIM: To investigate the relationship between the antigen MG7 antigen expression and gastric cancer as well as precancerous condition; to study the relationship between the MG7 antigen expression and H. pyloriinfection in benign gastric lesions in order to find out the effect of H. pylori infection on the process of gastric cancer development.METHODS: The level of MG7 antigen expression was determined by immunohistochemical method in 383 gastric biopsied materials. The intestinal metaplasia was determined by histochemistry method. The H. pyloriinfection was determined by HE stain, PCR and ELISA in 291 specimens, among which only 34 cases of H. pylori-associated gastric lesions were followed up.RESULTS: The positive rate of MG7 expression in normal gastric mucosa, intestinal metaplasia, dysplasia and gastric cancer increased gradually in ascending order (P＜0.01). The positive rate of MG7 antigen expression in type Ⅲ intestinal metaplasia of gastric mucosa was higher than that of type Ⅰand Ⅱ intestinal metaplasia, being highly significant (P＜0.05).The positive rate of MG7 antigen expression in superficial gastritis, atrophic gastritis and gastric cancer increased gradually (11.9 %, 64.8 %, 91.2 %, P＜0.01). There was no significant difference between H.pylori-negative and H. pyloripositive intestinal metaplasia, atrophic gastritis and dysplasia of gastric epithelium in the positive rate of MG7 antigen expression. There was no expression of MG7 antigen in H. pylori-negative superficial gastritis. The positive rate of MG7 expression in H. pylori-positive superficial gastritis was 20.5 %, and the difference between them was significant (P＜0.05). During following up, one of the three H. pylori negative cases turned positive again, and its MG7 antigen expression turned to be stronger correspondingly. 3 of 31 H. pyloripositive cases were detected as early gastric cancer, among which one with "+++" MG7 antigen expression was diminished after H. pylori eradication.CONCLUSION: MG7 antigen expression is highly specific in gastric cancer and can be used as a good marker for screening of gastric cancer; type Ⅲ intestinal metaplasia, atrophic gastritis and dysplasia should be followed up and MG7 antigen expression has high clinical value in the dynamic follow-up study; although the positive -MG7 in positiveH. pylorisuperficial gastritis show benign morphology in features, there is still the potential risk of developing into gastric cancer, hence special attention should be paid to those showing increasing MG7 antigen expression.     

Histological changes of gastric atrophy and intestinal metaplasia after Helicobacter pylori eradication]

BACKGROUND/AIMS: Long-term Helicobater pylori infection results in atrophic gastritis and intestinal metaplasia, and increases the risk of gastric cancer. However, it is still controversial that eradication of H. pylori improves atrophy or metaplasia. Therefore, we investigated histological changes after the H. pylori eradication in patients with atrophy or metaplasia. METHODS: One hundred seven patients who received successful eradication of H. pylori infection in Hanyang University, Guri Hospital from March 2001 to April 2006, were enrolled. Antral biopsy was taken before the eradication to confirm the H. pylori infection and grade of atrophy or metaplasia by updated Sydney System. After a certain period of time, antral biopsy was repeatedly taken to confirm the eradication and investigate histological changes of atrophy or metaplasia. RESULTS: Mean age of the patients was 55.3+/-11.3, and average follow-up period was 28.7+/-13.9 months. Endoscopic diagnosis included gastric ulcer, duodenal ulcer, non-ulcer antral gastritis. Atrophy was observed in 41 of 91 and their average score was 0.73+/-0.92. After the eradication of H. pylori, atrophy was improved (0.38+/-0.70, p=0.025). However, metaplasia which was observed in 49 of 107, did not significantly improve during the follow-up period. Newly developed atrophy (7 of 38) or metaplasia (18 of 49) was observed in patients who without atrophy or metaplasia initially. Their average scores were slightly lower than those of cases with pre-existing atrophy or metaplasia without statistical significance. CONCLUSIONS: After the eradication of H. pylori infection, atrophic gastritis may be improved, but change of intestinal metaplasia is milder and may take longer duration for improvement.     

Helicobacter pylori-induced inflammation masks the underlying presence of low-grade dysplasia on gastric lesions

BACKGROUND Helicobacter pylori(H. pylori) infection has been associated with a long-term risk of precancerous gastric conditions(PGC) even after H. pylori eradication.AIM To investigate the efficacy of High-Resolution White-Light Endoscopy with Narrow-Band Imaging in detecting PGC, before/after H. pylori eradication.METHODS We studied 85 consecutive patients with H. pylori-related gastritis with/without PGC before and 6 mo after proven H. pylori eradication. Kimura-Takemoto modified and endoscopic grading of gastric intestinal metaplasia classifications, were applied to assess the endoscopic extension of atrophy and intestinal metaplasia. The histological result was considered to be the gold standard. The Sydney System, the Operative-Link on Gastritis-Assessment, and the OperativeLink on Gastric-Intestinal Metaplasia were used for defining histological gastritis, atrophy and intestinal metaplasia, whereas dysplasia was graded according to World Health Organization classification. Serum anti-parietal cell antibody and anti-intrinsic factor were measured when autoimmune atrophic gastritis was suspected.RESULTS After H. pylori eradication histological signs of mononuclear/polymorphonuclear cell infiltration and Mucosal Associated Lymphoid Tissue-hyperplasia, disappeared or decreased in 100% and 96.5% of patients respectively, whereas the Operative-Link on Gastritis-Assessment and Operative-Link on Gastric-Intestinal Metaplasia stages did not change. Low-Grade Dysplasia prevalence was similar on random biopsies before and after H. pylori eradication(17.6% vs 10.6%, P = 0.19), but increased in patients with visible lesions(0% vs 22.4%, P 0.0001). At a multivariate analysis, the probability for detecting dysplasia after resolution of H. pylori-related active inflammation was higher in patients with regression or reduction of Mucosal Associated Lymphoid Tissue hyperplasia, greater alcohol consumption, and anti-parietal cell antibody and/or anti-intrinsic factor positivity [odds ratio(OR) = 3.88, 95% confidence interval(CI): 1.31-11.49, P = 0.01; OR = 3.10, 95%CI: 1.05-9.12, P = 0.04 and OR = 5.47, 95%CI: 1.33-22.39, P 0.04, respectively].CONCLUSION High-Resolution White-Light Endoscopy with Narrow-Band Imaging allows an accurate diagnosis of Low-Grade Dysplasia on visible lesions after regression of H. pylori-induced chronic gastritis. Patients with an overlap between autoimmune/H. pylori-induced gastritis may require more extensive gastric mapping.     

Pre and post eradication gastric inflammation in Helicobacter pylori-associated duodenal ulcer.

BACKGROUND: Distribution and nature of gastritis are major determinants of clinical outcome of H. pylori infection. The gastric inflammatory changes associated with this infection in developing countries have not been systematically studied. AIMS: To evaluate the inflammatory changes in gastric antrum and corpus in patients with duodenal ulcer and H. pylori infection, before and after H. pylori eradication therapy. METHODS: Histology and H. pylori density were studied in gastric biopsies obtained from 53 consecutive patients with active duodenal ulcer and H. pylori infection. Biopsies were obtained before and 4 weeks after H. pylori eradication therapy, from the anterior and posterior walls of the antrum and corpus, and were evaluated according to the Sydney system. RESULTS: In the pre-H. py/ori eradication antral biopsies, chronic gastritis, active gastritis, atrophy, intestinal metaplasia (IM) and lymphoid follicles / aggregates were seen in 53 (100%), 49 (92%), 11 (21%), 7 (13%) and 28 (53%) patients, respectively. In the corresponding biopsies from gastric corpus, these changes were seen in 49 (92%), 23 (43%), 2 (4%), 2 (4%) and 8 (15%), respectively. All changes except IM were significantly more frequent and of higher grade in the antrum. The grade of chronic gastritis was significantly higher in antrum than corpus; the frequency of gastritis in the antrum and corpus was similar (100% vs. 92%). H. pylori density was also higher in the antrum and correlated well with the grades of chronic gastritis and activity at both sites. Eradication of H. pylori was achieved in 39 patients (74%), and led to significant decrease in gastritis; no change was seen in patients who did not eradicate the organism. CONCLUSIONS: Antral-predominant chronic gastritis and activity are present in more than 90% of patients with H. pylori infection associated with duodenal ulcer, and the grade of gastritis correlates with the density of the organism. Eradication therapy results in improvement of both chronic gastritis and activity.     

胃黏膜病变演化过程中抗氧化蛋白Peroxiredoxin6的表达及其与幽门螺杆菌感染的关系

目的探讨胃黏膜病变演化过程中抗氧化蛋白Peroxiredoxin 6(Prx6)表达水平变化及其与幽门螺杆菌(H.pylori)感染的关系。方法根据组织形态学将104例临床内镜检查活检标本分为慢性浅表性胃炎(33例)、慢性萎缩性胃炎(25例)、肠上皮化生(32例)及异型增生(14例)4组。用免疫组织化学方法检测组织标本中Prx6的表达水平。用快速尿素酶试验及Warthin-Starry银染检测H.pylori感染。结果 Prx6在慢性浅表性胃炎、慢性萎缩性胃炎、肠上皮化生、异型增生组的阳性表达率分别为39.4%(13/33)、80.0%(20/25)、93.8%(30/32)、92.9%(13/14),过表达率分别为15.2%(5/33)、44.0%(11/25)、81.3%(26/32)、85.7%(12/14)。慢性浅表性胃炎、慢性萎缩性胃炎组H.pylori阳性者Prx6阳性表达率显著高于H.pylori阴性者(P<0.05),肠上皮化生组Prx6的表达在H.pylori阳性者和阴性者无显著差异(P>0.05)。结论在胃黏膜病变演化过程中,Prx6的表达随着胃黏膜病变的进展而增加,H.pylori在胃黏膜病变演化的早期阶段促进了Prx6的表达。     

Influence of gastritis on cyclooxygenase-2 expression before and after eradication of Helicobacter pylori infection

OBJECTIVES: Helicobacter pylori infection causes chronic gastritis and induces cyclooxygenase (COX)-2 expression. The relationship between gastritis and COX-2 expression is not well understood, especially long after the organism has been eradicated. We designed a study to elucidate this relationship. METHODS: Four endoscopic gastric biopsies from each of 118 H. pylori-infected subjects were assessed for COX-2 expression immunohistochemically, gastritis, by an updated Sydney System. In the 107 successfully eradicated subjects, the assessment was repeated once yearly, for 3 years. RESULTS: After successful eradication, COX-2 expression was reduced significantly regardless of site. Atrophy improved significantly and intestinal metaplasia improved but not in the antrum greater curvature. After 1 year COX-2 expression was not significantly different in the epithelia with and without intestinal metaplasia. Correlation between COX-2 expression and neutrophil score in the antrum (r = 0.214, P = 0.042) and inflammation in the corpus (r = 0.234, P = 0.025) disappeared after eradication. COX-2 expression correlated well with atrophy and metaplasia before and after eradication. No significant reduction in COX-2 or improvement in gastritis was found in subjects with eradication failure. CONCLUSION: H. pylori infection is associated with the enhancement of COX-2 expression in the gastric mucosa. Eradication therapy reduces COX-2 expression and hence may reduce the risk of cancer development.     

胃粘膜癌前病变中幽门螺杆菌与c-met原癌基因蛋白表达关系的研究

为研究Hp感染后胃粘膜细胞中c-met原癌基因蛋白表达的情况,了解Hp在胃癌发生过程中的作用,对110例经病理证实为慢性胃炎的病人用免疫组化方法检测了胃粘膜细胞中e-met原癌基因蛋白表达情况。结果表明,在浅表性胃炎、萎缩性胃炎、肠化生及异型增生中,e-met原癌基因蛋白的表达率分别为22.2％、44.1％、67.5％和61.9％。过表达率分别为5.5％、26.4％、37.8％和38.1％。Hp感染后c-met原癌基因蛋白表达率较末感染者高,分别为63％及32％,在萎缩,肠化生及异型增生等癌前病变中Hp感染者与未感染者表达率分别为58.9％及29.7％(P<0.005)。本研究结果显示,随着病变的进展,c-met原癌基因的表达随之增加,从而说明Hp感染对c-met原癌基因蛋白表达有一定的影响,Hp启动了胃癌发展的早期阶段,也可能推进胃癌的发展过程。     

原位杂交方法检测胃癌及其癌前病变中抑癌基因p53的表达

目的用原位杂交方法检测胃粘膜癌前病变及胃癌组织中ｐ５３ｍＲＮＡ的表达,并观察感染Ｈｐ对其表达的影响．方法病理证实为慢性胃炎６６例和胃癌１６例,用地高辛标记的ｃＤＮＡ为探针进行原位杂交实验,检测其胃粘膜组织中ｐ５３ｍＲＮＡ表达,用单克隆抗体ＤＯ０１进行免疫组化检测Ｐ５３蛋白的表达．结果在慢性萎缩性胃炎、肠化生、异型增生及胃癌中,原位杂交方法检测ｐ５３ｍＲＮＡ表达率分别为５３９％,５２３％,４２８％和２５％,免疫组化方法检测Ｐ５３蛋白的表达率分别为００％,５３％,１５４％和２５％．ｐ５３ｍＲＮＡ的表达与蛋白的表达无明显的一致性,ｐ５３ｍＲＮＡ的表达可以在Ｐ５３蛋白阴性及阳性的细胞中．在２６例萎缩性胃炎中,１４例检测到ｐ５３ｍＲＮＡ的表达,而其中１６例（包括１４例阳性病例）无一例检测到Ｐ５３蛋白的表达．在肠化生、异型增生及胃癌组织中也发现有类似的情况．Ｈｐ感染组与未感染组,ｐ５３ｍＲＮＡ表达率之间统计学检验Ｐ＜００５．结论在胃癌及其癌前病变中,随着病变的发展,ｐ５３ｍＲＮＡ的表达率随之下降,Ｈｐ对其表达有明显的影响     

Eradication of Helicobacter pylori decreases the expression of p53 and c-Myc oncogenes

Background and study aimsAlthough it is fairly well accepted that Helicobacter pylori infection (H. pylori) plays a significant role in causing gastric cancer, the exact mechanisms involved in its pathogenesis are unclear and there is controversial data about the state of chronic gastritis and the precancerous lesion after treatment of H. pylori. This study was designed to investigate the relationship between H. pylori infection, the activity of chronic gastritis and oncogenes before and after treatment of H. pylori.Patients and methodsFifty-five of chronic gastritis cases were studied for H. pylori, activity of chronic gastritis, p53 and c-Myc expression. Positive H. pylori cases were re-evaluated again for the activity of gastritis, expression of p53 and c-Myc after treatment (6 months later).ResultsForty-five cases were positive for H. pylori. The activity of chronic gastritis correlated with H. pylori infection. p53 and c-Myc expression correlated positively with the grade of chronic gastritis. After treatment of H. pylori, the activity of gastritis decreased and the expression of both p53 and c-Myc decreased.ConclusionH. pylori infection in the gastric mucosa may be implicated in the pathway of gastric carcinogenesis. It seems that H. pylori infection is responsible for early genomic instability even before any neoplastic changes and its eradication can reverse the sequence of inflammation and related atrophy, metaplasia, and genomic instability and, thus, may prevent gastric cancer development.     

Mucosal changes in the gastric remnant: long-term effects of bile reflux diversion and Helicobacter pylori infection

OBJECTIVE: Bile reflux is thought to be responsible for reflux gastritis and stump carcinoma occurring after partial gastrectomy for peptic ulcer. Gastritis and gastric carcinoma are also correlated with Helicobacter pylori. The aim of this study was to investigate whether diversion of enteric reflux and the presence of H. pylori infection alter long-term histological developments in the gastric remnant. METHODS: Twenty-nine patients partially gastrectomized for peptic ulcer were reoperated on with re-resection and a Roux-en-Y reconstruction because of reflux gastritis (12 patients) or severe dysplasia/early gastric cancer (17 patients). The resected specimens and subsequent biopsies from the new anastomotic region taken at endoscopies 5-17 years after reoperation were evaluated regarding the presence of H. pylori, the grade of active and non-active chronic gastritis, and the premalignant changes--atrophy, intestinal metaplasia and dysplasia. RESULTS: A progression of active chronic gastritis, atrophy, intestinal metaplasia and dysplasia was seen after re-resection and Roux-en-Y reconstruction. Non-active chronic gastritis remained unchanged. The development was, in general, independent of H. pylori infection. CONCLUSIONS: Enteric reflux may perhaps induce a histological transformation of the gastric mucosa that cannot be reversed, even if the reflux is diverted. In our study, H. pylori infection had no impact on the histological development. Factors other than enteric reflux and H. pylori infection might also be of importance.     

Mutant p53 expression and apoptotic activity of Helicobacter pylori positive and negative gastritis in correlation with the presence of intestinal metaplasia

BACKGROUND: Mutation of the p53 gene is detectable in most cases of gastric cancer, as it is the most common genetic alteration in human malignancies. It is also well documented that Helicobacter pylori infection plays an important role in gastric carcinogenesis. There is still no clarification, however, concerning how genetic instability influences the homeostasis of gastric epithelium. We have studied the effect of H. pylori infection on apoptosis of the antral epithelium in the presence/absence of intestinal metaplasia and the expression of the p53 oncoprotein. The relationship between these two processes is analysed. METHODS: Antral biopsies were taken from 36 patients who underwent routine upper endoscopy (17 men, 19 women, mean age 61.0 years). The biopsies were fixed in formalin and embedded in paraffin. Patients were classified into two histological groups: (1) as chronic gastritis without intestinal metaplasia (n = 19), and (2) chronic gastritis with intestinal metaplasia (n = 17). An immunohistochemical method was used to detect the expression of p53 oncoprotein, and the terminal transferase mediated dUTP nick end-labelling (TUNEL) method was used to detect apoptotic cells. RESULTS: In the absence of intestinal metaplasia, both the apoptotic index (0.0272 +/- 0.011 vs 0.0128 +/- 0.006) and expresssion of p53 (35.55 +/- 31.16 vs 18.33 +/- 19.65) were significantly higher in H. pylori positive cases compared to H. pylori negative cases. In the presence of intestinal metaplasia, p53 expression was further increased (P < 0.05), but apoptosis was similar to that observed in H. pylori negative gastritis without intestinal metaplasia. In the presence of intestinal metaplasia, H. pylori infection did not influence apoptosis (0.013 +/- 0.004 vs 0.011 +/- 0.004), or p53 ratio (70.16 +/- 22.54 vs 68.50 +/- 28.96). In the sequence of gastritis-intestinal metaplasia the two indices show a close negative correlation (P < 0.05). CONCLUSION: In the absence of intestinal metaplasia H. pylori infection increases both apoptotic activity and expression of p53 oncoprotein in the gastric mucosa. The lack of increased apoptosis with a higher p53 expression in the presence of intestinal metaplasia suggests an increased genetic instability and also may suggest that mutation of the p53 gene is an early step in the multistep process of gastric carcinogenesis.     

Helicobacter pylori infection, glandular atrophy and intestinal metaplasia in superficial gastritis, gastric erosion, erosive gastritis, gastric ulcer and early gastric cancer

AIM: To evaluate the histological features of gastric mucosa, including Helicobacter pylori infection in patients with early gastric cancer and endoscopically found superficial gastritis, gastric erosion, erosive gastritis, gastric ulcer. METHODS: The biopsy specimens were taken from the antrum, corpus and upper angulus of all the patients. Giemsa staining, improved toluidine-blue staining, and Hpylori-specific antibody immune staining were performed as appropriate for the histological diagnosis of H pylori infection. Hematoxylin-eosin staining was used for the histological diagnosis of gastric mucosa inflammation, gastric glandular atrophy and intestinal metaplasia and scored into four grades according to the Updated Sydney System. RESULTS: The overall prevalence of H pylori infection in superficial gastritis was 28.7%, in erosive gastritis 57.7%, in gastric erosion 63.3%, in gastric ulcer 80.8%, in early gastric cancer 52.4%. There was significant difference (P<0.05), except for the difference between early gastric cancer and erosive gastritis. H pylori infection rate in antrum, corpus, angulus of patients with superficial gastritis was 25.9%, 26.2%, 25.2%, respectively; in patients with erosive gastritis 46.9%, 53.5%, 49.0%, respectively; in patients with gastric erosion 52.4%, 61.5%, 52.4%, respectively; in patients with gastric ulcer 52.4%, 61.5%, 52.4%, respectively; in patients with early gastric cancer 35.0%, 50.7%, 34.6%, respectively. No significant difference was found among the different site biopsies in superficial gastritis, but in the other diseases the detected rates were higher in corpus biopsy (P<0.05). The grades of mononuclear cell infiltration and polymorphonuclear cell infiltration, in early gastric cancer patients, were significantly higher than that in superficial gastritis patients, lower than that in gastric erosion and gastric ulcer patients (P<0.01); however, there was no significant difference compared with erosive gastritis. The grades of mucosa glandular atrophy and intestinal metaplasia were significantly highest in early gastric cancer, lower in gastric ulcer, the next were erosive gastritis, gastric erosion, the lowest in superficial gastritis (P<0.01). Furthermore, 53.3% and 51.4% showed glandular atrophy and intestinal metaplasia in angular biopsy specimens, respectively; but only 40.3% and 39.9% were identified in antral biopsy, and 14.1% and 13.6% in corpus biopsy; therefore, the angulus was more reliable for the diagnosis of glandular atrophy and intestinal metaplasia compared with antrum and corpus (P<0.01). The positivity rate of glandular atrophy and intestinal metaplasia of superficial gastritis with H pyloripositivity was 50.7%, 34.1%; of erosive gastritis 76.1%, 63.0%; of gastric erosion 84.8%, 87.8%; of gastric ulcer 80.6%, 90.9%; and of early gastric cancer 85.5%, 85.3%, respectively. The positivity rate of glandular atrophy and intestinal metaplasia of superficial gastritis with H pylorinegativity was 9.9%, 6.9%; of erosive gastritis 42.5%, 42.1%; of gastric erosion 51.1%, 61.9%; of gastric ulcer 29.8%, 25.5%; and of early gastric cancer 84.0%, 86.0%, respectively. The positivity rate of glandular atrophy and intestinal metaplasia of superficial gastritis, erosive gastritis, gastric erosion, and gastric ulcer patients with H pylon positivity was significantly higher than those with H pylori negativity (P<0.01); however, there was no significant difference in patients with early gastric cancer with or without H pylori infection. CONCLUSION: The progression of the gastric pre-cancerous lesions, glandular atrophy and intestinal metaplasia in superficial gastritis, gastric erosion, erosive gastritis and gastric ulcer was strongly related to H pylori infection. In depth studies are needed to evaluate whether eradication of H pylori infection will really diminish the risk of gastric cancer.     

Effects of Helicobacterpylori eradication on atrophic gastritis and intestinal metaplasia： A 3-year follow-up study

AIM: To investigate the effect of H pylori eradication on atrophic gastritis and intestinal metaplasia (IM). METHODS: Two hundred and fifty-nine patients with atrophic gastritis in the antrum were included in the study, 154 patients were selected for H pylori eradication therapy and the remaining 105 patients served as untreated group. Gastroscopy and biopsies were performed both at the beginning and at the end of a 3-year follow-up study. Gastritis was graded according to the updated Sydney system. RESULTS: One hundred and seventy-nine patients completed the follow-up, 92 of them received H pylori eradication therapy and the remaining 87 H pylori-infected patients were in the untreated group. Chronic gastritis, active gastritis and the grade of atrophy significantly decreased in H pylori eradication group (P<0.01). However, the grade of IM increased in H pylori -infected group (P<0.05). CONCLUSION: H pylori eradication may improve gastric mucosal inflammation, atrophy and prevent the progression of IM.     

Effect of Helicobacter pylori infection on p53 expression of gastric mucosa and adenocarcinoma with microsatellite instability

AIM: To investigate the relationship between Helicobacter pylori (H pylori) infection, microsatellite instability and the expressions of the p53 in gastritis, intestinal metaplasia and gastric adenocarcinoma and to elucidate the mechanism of gastric carcinogenesis relating to H pylori infection. METHODS: One hundred and eight endoscopic biopsies and gastric adenocarcinoma were available for the study including 33 cases of normal, 45 cases of gastritis, 30 cases of intestinal metaplasia, and 46 cases of gastric adenocarcinoma. Peripheral blood samples of these patients were also collected. H pylori infection and p53 expressions were detected by means of streptavidin-peroxidase (SP) immunohistochemical method. Microsatellite loci were studied by PCR-SSCP-CE using the markers BAT-26, D17S261, D3S1283, D2S123, and D3S1611. MSI was defined as the peak shift in the DNA of the gastric tissue compared with that of the peripheral blood samples. Based on the number of mutated MSI markers, specimens were charac-terized as high MSI (MSI-H) if they manifested instability at two or more markers, low MSI (MSI-L) if unstable at only one marker, and microsatellite stable (MSS) if they showed no instability at any marker. RESULTS: H pylori infection was detected in the samples of gastritis, intestinal metaplasia, and gastric adenocarcinoma and the infection frequencies were 84.4%, 76.7%, and 65.2%, respectively, whereas no H pylori infection was detected in the samples of normal control. There was a significant difference in the infection rates between gastritis and carcinoma samples (P= 0.035). No MSI was detected in gastritis samples, one MSI-H and two MSI-L were detected among the 30 intestinal metaplasia samples, and 12 MSI-H and 3 MSI-L were detected in the 46 gastric carcinomas. In those gastric carcinomas, the MSI-H frequency in H pylori-positive group was significantly higher than that in H pylori- negative group. No p53 expression was detected in the normal and gastritis samples from dyspeptic patients. P53-positive immunohistochemical staining was detected in 13.3% of intestinal metaplasia samples and in 43.5% of gastric carcinoma samples. The levels of p53 in H pylori-positive samples were higher than those in the negative group when the carcinoma samples were subdivided into H py/ori-positive and -negative groups (P=0.013). Eight samples were detected with positive p53 expression out of the 11 MSI-H carcinomas with H pylori infection and no p53 expression could be seen in the H pylori-negative samples. CONCLUSION: H pylori affect the p53 pattern in gastric mucosa when MMR system fails to work. Mutations of the p53 gene seem to be an early event in gastric carcinogenesis.     

Prevalence of Helicobacter pylori infection and gastric cancer precursor lesions in patients with dyspepsia

BACKGROUND: Helicobacter pylori infection has been considered to play significant role in gastric carcinogenesis, but only a minority of people who harbor this organism will develop gastric cancer. H. pylori infection first causes chronic non atrophic gastritis. Chronic non atrophic gastritis may evolve to atrophic gastritis and intestinal metaplasia and finally to dysplasia and adenocarcinoma. AIMS: To estimate the prevalence of H. pylori infection and the precancerous gastric lesions and their relationship, in patients with dyspeptic symptoms who underwent upper gastrointestinal endoscopy at a reference center in the central region of Rio Grande do Sul state, Brazil. METHODS: We analyzed gastric biopsies taken from corpus and antrum of patients who underwent upper gastrointestinal endoscopy for H. pylori detection, between 1994 and 2003. According to Sydney system, chronic non atrophic gastritis, atrophic gastritis and intestinal metaplasia were diagnosed by histological examination (H-E stain). The histological diagnoses were related to H. pylori infection status. RESULTS: Biopsies from 2,019 patients were included in the study. Patients mean age was 52 (+/-15) and 59% were female. Seventy six percent had H. pylori infection. Normal mucosa, chronic non atrophic gastritis, atrophic gastritis and intestinal metaplasia were diagnosed in 5%, 77%, 3% and 15%, respectively. The OR for any degree of gastric mucosa lesion in infected patients was 10 (CI95% 6.50 - 17%). The OR for infected patients had chronic non atrophic gastritis was 3 (CI95% 2,2 - 3,4). The OR for infected patients had atrophic gastritis or intestinal metaplasia was less than 1. CONCLUSIONS: The prevalence of H. pylori infection in this population was high (76%) and infected individuals had the probability 10 folds greater than non infected individuals to have any lesion of gastric mucosa. The prevalence of precancerous lesions was 77% for non atrophic chronic gastritis, 3% for atrophic gastritis and 15% for intestinal metaplasia. Infected patients had risk 3 folds greater than non-infected for the occurrence of non atrophic chronic gastritis. H. pylori infection did not show risk for occurrence of atrophic gastritis and intestinal metaplasia, suggesting that other risk factors should be involved in the carcinogenesis process.     

Multifocal atrophic gastritis and gastric carcinoma

Gastric carcinoma remains a major cause of morbidity and mortality worldwide despite its significant decline in recent years. H. pylori infection begins with nonatrophic gastritis, and most individuals continue to have nonatrophic H. pylori gastritis throughout their lifetime. A minority of those with severe antral inflammation will develop a duodenal ulcer, and a few, for unknown reasons, may develop gastric MALT lymphoma. Others, who acquired the H. pylori infection in early childhood, develop progressive multifocal atrophic gastritis with loss of gastric glands. A small proportion of these individuals develop extensive, incomplete (type III) intestinal metaplasia, and an even smaller proportion will progress to dysplasia and intestinal-type gastric carcinoma. H. pylori-associated gastritis is also a risk factor for diffuse-type gastric carcinoma, which is not preceded by atrophy, intestinal metaplasia, or dysplasia. Appropriate screening and preventive measures should be considered in high-risk groups. It is also crucial to identify cofactors such as genetic susceptibility and environmental factors that might interact with H. pylori infection to increase gastric cancer risk. To make an impact on gastric cancer incidence and mortality, serious consideration should be given to early H. pylori eradication in high-risk groups and endoscopic surveillance according to the updated Sydney system in some patients with high-risk preneoplastic lesions, whereas dysplastic lesions should be removed without delay. Studies currently in progress may tell us whether H. pylori eradication can prevent later development of gastric carcinoma and thus eliminate a major cause of mortality worldwide.