根除Hp前后胃窦粘膜COX-2表达的变化

目的检测胃窦粘膜在根除Hp前后环氧化酶-2(Cyclooxygenase-2,COX-2)表达水平的变化,探讨COX-2表达与急、慢性炎症的关系.方法对我院1999.6-2000.3胃镜诊断为慢性胃炎、胃粘膜活组织尿素酶试验和14C尿素呼气试验均证实Hp阳性的14例住院病人,在根除Hp前后取胃粘膜活检组织,HE染色显示组织结构和炎性细胞浸润情况,用免疫组织化学方法(SP法)显示COX-2表达情况.结果感染区域的胃窦上皮细胞和相应的壁细胞、单核细胞均可检测到COX-2的阳性表达,与根除Hp后比较,COX-2的表达明显减少而不完全消失(P＜0.005),COX-2阳性表达率与胃粘膜的急性炎症程度无关,而与慢性炎性细胞浸润密切相关(r=0.74 P＜0.05).结论COX-2的高表达可能是Hp相关性胃炎发生的重要机制.     

环氧合酶-2表达与幽门螺杆菌相关性胃十二指肠疾病的研究

目的　探讨环氧合酶 2表达与幽门螺杆菌Helicobacterpylori ,H .pylori相关性胃十二指肠疾病的关系 ,并通过抗菌治疗评价根除H pylori感染对胃窦黏膜中COX 2表达的影响。方法　用免疫组化方法半定量检测 2 64例经胃镜和组织病理学检查患有十二指肠球部溃疡、胃溃疡、复合性溃疡、胃癌、单纯性慢性胃炎及胃黏膜正常者的胃窦黏膜COX 2蛋白的表达 ,比较H pylori感染与非感染者之间的差异。对检出的 3 5例H pylori的单纯慢性胃炎进行H pylori抗菌根除治疗 ,比较根除前后胃窦黏膜COX 2蛋白的表达变化。根据 2 0 0 0年 5月全国慢性胃炎研讨会共识意见 (江西 井冈山 )对胃黏膜炎症、活动性、异型增生、肠化生和H pylori密 ,度进行半定量测定。结果　胃黏膜表面上皮、腺上皮细胞和固有层间质细胞的浆中可见COX 2蛋白表达 ,但阳性染色细胞多集中在表层上皮。 2 53例中 ,14 3例H pylori者 (56 52 % )COX 2平均阳性细胞率显著高于 110例H pylori者 (43 48% ) ,(P =0 ) ,各疾病组H pylori患者的COX 2平均阳性细胞率均显著高于H pylori者 (P =0 ) ,各疾病组H pylori患者COX 2平均阳性细胞率也均显著高于正常对照组 (P <0 0 5)。 2 7例H pylori根除后的胃黏膜COX 2平均阳性细胞率明显下降 (P =0 ) ,但仍明显高于正     

Disappearance of gastritis after eradication of Helicobacter pylori. A morphometric study

Helicobacter pylori infection is strongly associated with and is considered a common cause of gastritis. To study the relationship between H. pylori and gastritis, we examined whether a reduction occurs in acute granulocytic and chronic mononuclear inflammation of gastric mucosa after eradication therapy. The examination is based on morphometric counting and on semiquantitative estimation of the density of the inflammatory cells in endoscopic biopsy specimens from antrum and corpus. The series consisted of 23 consecutive outpatients with H. pylori-associated gastritis who received a 2-week course of triple therapy with colloidal bismuth subcitrate, amoxicillin, and metronidazole and who underwent an endoscopic follow-up for 6 weeks, 6 months (23 patients), and 12 months (21 patients). The eradication was successful in 20 patients ('responders'), who also remained H. pylori-free for 6 months, and in 18 examined patients for 12 months but was unsuccessful in 3 patients ('non-responders'). Both acute and chronic inflammation decreased significantly in intensity in responders in the follow-up. The acute inflammation had already disappeared at a 6-week control. The reduction in chronic inflammation was slower and occurred gradually within the study. At the 12-month follow-up, the corpus mucosa was interpreted as normal in all 18 patients studied, and the antral mucosa was interpreted as normal in 10 (56%) patients. No significant reduction in intensity of gastritis was found in the 3 non-responders or the 23 matched, untreated controls. We conclude that the eradication of H. pylori results in a disappearance of both acute and chronic gastritis. This supports the view that H. pylori plays a causal role in the pathogenesis of chronic gastritis.     

Is apoptosis in antral mucosa correlated with serum nitrite concentration in Japanese Helicobacter pylori‐infected patients?

BACKGROUND AND AIM: Helicobacter pylori infection in gastric mucosa is a form of chronic active gastritis that leads to expression of inducible nitric oxide synthase in host macrophages and polymorphonuclear leukocytes. Nitric oxide produced by these cells infiltrating the gastric mucosa could damage DNA. We correlated apoptosis in H. pylori-infected antral tissue from peptic ulcer patients with serum nitrate-plus-nitrite. METHODS: Biopsy specimens were obtained endoscopically from antrum and fundus in 17 peptic ulcer patients before and after H. pylori eradication. Tissue samples were subjected to rapid urease testing and histopathological scoring (updated Sydney system), as well as immunohistochemical detection of single-stranded DNA indicating apoptotic cells. Fasting serum samples were analyzed for combined nitrate and nitrite content. RESULTS: In all cases atrophy was absent to mild in antral mucosa and H. pylori was eradicated successfully. A strong positive correlation was present between apoptosis and both inflammation and activity scores in infected antral mucosa. A significant positive correlation also was noted between apoptosis and H. pylori density. Serum nitrite concentrations were decreased significantly by successful eradication of H. pylori, and showed a strong positive correlation with H. pylori density. Serum nitrite concentrations showed a significant positive correlation with numbers of single-stranded DNA-positive cells. CONCLUSIONS: High H. pylori density was associated with elevated serum nitrate-plus-nitrite (a marker of nitric oxide production in gastric mucosa). Increased apoptosis and abnormal gastric cell turnover are likely results.     

Increase in apoptosis and decrease in ornithine decarboxylase activity of the gastric mucosa in patients with atrophic gastritis and gastric ulcer after successful eradication of Helicobacter pylori

OBJECTIVE: Recent reports have shown that patients infected with Helicobacter pylori (H. pylori) have a higher risk of gastric cancer. However, the mechanism of this increased risk is still unclear. In the gastric mucosa, the size of a continuously renewed population of cells is determined by the rates of cell production and of cell loss. Ornithine decarboxylase (ODC) activity is elevated in various gastrointestinal cancers and serves as a marker of mucosal proliferative activity. Apoptosis occurs throughout the gut and is associated with cell loss. Both cell proliferation and cell loss have important roles in H. pylori-associated gastric carcinogenesis. Therefore, we investigated the effect of H. pylori eradication on ODC activity and apoptosis in the gastric mucosa of patients with atrophic gastritis and gastric ulcers. METHODS: Biopsy specimens of the gastric antrum were obtained at endoscopy from 17 H. pylori-positive gastric ulcers patients and 15 H. pylori-positive gastritis patients before and 4 wk after eradication therapy with amoxicillin, omeprazole, and a new anti-ulcer agent, ecabet sodium, and from 10 gastric ulcer patients in whom ulcer healed but H. pylori was left untreated. ODC activity and induction of apoptosis were determined immunohistochemically. RESULTS: H. pylori was successfully eradicated with the triple therapy in 12 (80%) of 15 gastritis patients and 13 (76%) of 17 gastric ulcer patients. ODC activity was present in the gastric mucosa in 21 (84%) patients before eradication but in only four (16%) patients after successful eradication (p = 0.0005). The apoptotic index increased significantly (p = 0.0006) from 4.2% +/- 0.4% before treatment to 7.4% +/- 0.5% after successful eradication. CONCLUSIONS: Successful eradication of H. pylori decreases mucosal ODC activity and increases apoptosis in the gastric mucosa. These findings indicate that by decreasing mucosal cell proliferation and increasing epithelial cell loss, H. pylori eradication may help decrease the subsequent risk of gastric cancer.     

The interaction of H. pylori infection and NSAIDs in cyclooxygenase-2 mRNA expression in gastric antral, corpus mucosa, and gastric ulcer

BACKGROUND: Although Helicobacter pylori infection and use of nonsteroidal anti-inflammatory drugs (NSAIDs) are the two major causes of gastric ulcer, their interaction remains controversial. We constructed a prospective cohort study to evaluate how these two factors influence the expression of COX-2 mRNA in gastric antral, corpus mucosa, and gastric ulcer. METHODS: Tissues were obtained by endoscopic biopsy of gastric antral, corpus mucosa, and gastric ulcer. The presence of H. pylori was determined by culture or histology using Giemsa stain. NSAID use was assessed by structured questionnaire and medical record review. The expression of COX-2 mRNA was detected by the TaqMan quantitative RT-PCR system. RESULTS: H. pylori infection was associated with increased COX-2 expression only in antral mucosa (0.77 +/- 0.13 vs. 0.31 +/- 0.07, P < 0.01). NSAID use was significantly associated with decreased COX-2 expression in ulcer (4.49 +/- 1.50 vs. 9.82 +/- 2.48, P < 0.05) but not in antral or corpus mucosa. Regarding the interaction between H. pylori and NSAID, we found that H. pylori infection was associated with increased COX-2 expression in antral mucosa for both NSAID users and nonusers. In NSAID users, H. pylori infection was not associated with increased COX-2 expression in ulcer edge. CONCLUSION: H. pylori infection was associated with increased COX-2 expression in gastric antral mucosa for both NSAID users and nonusers, but not in gastric ulcer, where the effect of NSAID inhibition plays a major role. With these observations, we can interpret indirectly that H. pylori eradication does not interfere with gastric ulcer healing in NSAID users.     

中国上消化道疾病患者幽门螺杆菌感染根除前后胃粘膜病理改变与空泡毒素活性的关系

目的：观察幽门螺杆菌（H.pylori)阳性消化性溃疡病和慢性胃炎患者H.pylori根除前后胃粘膜病理改变与空泡毒素（VacA)活性的关系。方法：功能性消化不良伴H.pylori感染的中国患者74例,于H.pylori根除前和4－6周后作胃镜检查,根据新悉尼病理分级法按半定量记分对治疗前后的胃粘膜病理变化程度进行分级。结果：VacA^ 菌检出率为80％（59／74）,消化性溃疡病患者的检出率与慢性胃炎患者无明显差别;VacA^ 和VacA^-组患者的H.pylori根除率亦无明显差别。根除治疗前,VacA^ 和VacA^-组患者的胃粘膜慢性炎症、活动性、表面上皮损伤、萎缩、肠化和淋巴滤泡数量无显著差别;治疗后4－6周,两组患者的胃窦粘膜炎症活动性、表面上皮损伤和慢性炎症程度均明显减轻,尤以前者为著（P＜0．0001）,VacA^ 组患者的胃窦部淋巴滤泡数量减少亦稍较VacA^-组明显（P＝0．051）,两组患者的胃粘膜萎缩和肠化程度均无明显好转。结论：中国上消化道疾病患者H.pylori感染根除前后的胃粘膜病理改变与VacA活性无明显关系。成功根除H.pylori感染并不引起萎缩和肠化的逆转。     

Somatostatin and D cells in patients with gastritis in the course of Helicobacter pylori eradication: a six-month,follow-up study

BACKGROUND/AIMS: As well as causing chronic gastritis, Helicobacter pylori predisposes patients to peptic ulcer disease and gastric cancer, and induces gastric functional disorders. The aim of our study was to investigate the effects of H. pylori eradication therapy on the morphological and functional recovery of gastric antral and corpus D cells in patients with chronic gastritis during 6 months of follow-up. PATIENTS AND METHODS: Forty consecutive, dyspeptic patients referred for endoscopy (31 with H. pylori infection and nine controls; mean age 49 years; 17 men, 23 women) entered the study. All patients had histological signs of gastritis but no signs of peptic ulcer or gastric cancer. Antrum (n=8) and corpus (n=6) biopsy specimens were collected for routine histology, radioimmunoassay tissue somatostatin levels, immunohistochemistry and electron microscopy, prior to and 6 months after therapy. Basal plasma somatostatin levels were determined prior to eradication, plus 6 weeks and 6 months after therapy. Eradication therapy consisted of amoxicillin, metronidazole and omeprazole. RESULTS: Basal somatostatin plasma values in antral and corpus tissue were lower in infected patients than in the H. pylori-negative controls at the beginning of the study. A significant increase occurred after successful eradication therapy, together with an increase in the number of D cells in both regions. Changes in the D-cell ultrastructure in antral and corpus mucosa after eradication therapy suggest an increase in somatostatin synthesis and secretion. CONCLUSIONS: The structural and functional restoration of D cells following eradication therapy indicates possible recovery of the diseased mucosa.     

Effect of Helicobacter pylori infection on cyclooxygenase‐2 expression in gastric antral mucosa

OBJECTIVE: Helicobacter pylori infection is a major etiological cause of chronic gastritis. Inducible cyclooxygenase (COX‐2) is an important regulator of mucosal inflammation. Recent studies indicate that expression of COX‐2 may contribute to gastro­intestinal carcinogenesis. The aim of this study was to investigate the effects of H. pylori infection and eradication therapy on COX‐2 expression in gastric antral mucosa. METHODS: Antral biopsies were taken from 46 H. pylori‐infected patients, who also had chronic gastritis, both before and after anti‐H. pylori treatment. The COX‐2 protein was stained by using immunohistochemical methods and COX‐2 expression was quantified as the percentage of epithelial cells expressing COX‐2. Gastritis and H. pylori infection status were graded according to the Sydney system. RESULTS: Cyclooxygenase‐2 expression was detected in the cytoplasm of gastric antral epithelial cells both before and after the eradication of H. pylori. Cyclooxygenase‐2 expression in mucosa with H. pylori infection was compared with the corresponding mucosa after successful H. pylori eradication (20.1 ± 13.1%vs 13.8 ± 5.9%; P < 0.05). At the same time, COX‐2 expression in H. pylori‐infected mucosa was com­pared with the normal controls (18.0 ± 14.1%vs 12.3 ± 4.6%, P < 0.05). Expression of COX‐2 was correlated with the degree of chronic inflammation (r= 0.78, P < 0.05). CONCLUSIONS: Our results showed that H. pylori infection leads to gastric mucosal overexpression of COX‐2 protein, suggesting that the enzyme is involved in H. pylori‐related gastric pathology in humans.     

Roles of Helicobacter pylori infection and cyclooxygenase-2 expression in gastric carcinogenesis

AIM: Cyclooxygenase (COX)-2 is over expressed in gastrointestinal neoplasm. Helicobacter pylori (H pylori) infection is causally linked to gastric cancer. However, the expression of COX-2 in various stages of H pylori-associated gastric carcinogenesis pathway has not been elucidated. Therefore, the aim of this study was to clarify the role of H pylori induced COX-2 expression during carcinogenesis in the stomach. METHODS: Gastric biopsies from 138 subjects (30 cases of chronic superficial gastritis (CSG), 28 cases of gastric glandular atrophy (GA), 45 cases of gastric mucosal intestinal metaplasia (IM), 12 cases of moderate gastric epithelial dysplasia and 23 cases of gastric cancer) were enrolled. H pylori infection was assessed by a rapid urease test and histological examination (modified Giemsa staining). The expression of COX-1 and COX-2 in human gastric mucosa was detected by immunohistochemical staining. RESULTS: H pylori infection rate was 64.3% in GA and 69.5% in gastric cancer, which was significantly higher than that (36.7%) in CSG (P<0.05). The positive expression rates of COX-2 were 10.0%, 35.7%, 37.8%, 41.7% and 69.5% in CSG, GA, IM, dysplasia and gastric cancer, respectively. From CSG to GA, IM, dysplasia and finally to gastric cancer, expression of COX-2 showed an ascending tendency, whereas COX-1 expression did not change significantly in the gastric mucosa. The level of COX-2 expression in IM and dysplasia was significantly higher in H pylori-positive than in H pylori-negative subjects (P<0.01). CONCLUSION: COX-2 expression induced by H pylori infection is a relatively early event during carcinogenesis in the stomach.     

幽门螺杆菌感染诱导胃粘膜环氧化酶-2表达

目的 探讨幽门螺杆菌（Hp)感染对胃粘膜环氧化酶－2（COX－2）表达的影响。方法 27例无任何症状健康检查者，经胃镜采取胃窦部粘膜组织，用于Hp检测、病理组织学检查及免疫组织化学检查COX－2的表达。结果 18例Hp感染者胃粘膜上皮细胞和炎症细胞表达COX－2，而9例Hp阴性者胃粘膜均不表达COX－2。结论 Hp感染诱导胃粘膜COX－2表达。     

Expression of cytokeratins in Helicobacter pylori -associated chronic gastritis of adult patients infected with cagA ＋ strains： An immunohistochemical study

AIM:To investigate the expression of differentcytokeratins(CKs)in gastric epithelium of adult patientswith chronic gastritis infected with Helicobacter pylori(Hpylori)cagA strains.METHODS:The expression of CK 7,8,18,19 and 20was studied immunohistochemically in antral gastricbiopsies of 84 patients.All the CKs were immunostainedin cagA H pylori gastritis(57 cases),non-H pylori gastritis(17 cases)and normal gastric mucosa(10 cases).RESULTS:In cagA H pylori gastritis,CK8 wasexpressed comparably to the normal antral mucosafrom surface epithelium to deep glands.Distributionof CK18 and CK 19 was unchanged,i.e.transmucosal,but intensity of the expression was different in foveolarregion in comparison to normal gastric mucosa.Cytokeratin 18 immunoreactivity was significantly higherin the foveolar epithelium of H pylori-positive gastritiscompared to both Hpylori-negative gastritis and controls.On the contrary,decrease in CK19 immunoreactivityoccurred in foveolar epithelium of H pylori-positive gastritis.In both normal and inflamed antral mucosawithout Hpylori infection,CK20 was expressed strongly/moderately and homogenously in surface epithelium andupper foveolar region,but in H pylori-induced gastritissignificant decrease of expression in foveolar regionwas noted.Generally,in both normal antral mucosa andH pylori-negative gastritis,expression of CK7 was notobserved,while in about half cagA H pylori-infectedpatients,moderate focal CK7 immunoreactivity of theneck and coiled gland areas was registered,especially inareas with more severe inflammatory infiltrate.CONCLUSION:Alterations in expression of CK 7,18,19 and 20 together with normal expression of CK8 occurin antral mucosa of H pylori-associated chronic gastritisin adult patients infected with cagA strains.Alterationsin different cytokeratins expression might contribute toweakening of epithelial tight junctions observed in Hpylori-infected gastric mucosa.     

Patient Factors Affecting Helicobacter pylori Eradication with Triple Therapy

Duodenal ulcer recurrence and gastritis are reduced with successful Helicobacter pylori treatment. To identify the patient factors influencing H. pylori eradication, we prospectively evaluated 96 consecutive patients undergoing a single 2-wk course of bismuth, tetracycline, and metronidazole therapy. At the time of initial esophagogastroduodenoscopy with biopsies, each patient had a profile obtained which included demographic information, gastrointestinal pathology, and H. pylori status of the spouse. Elimination of H. pylori was confirmed by repeat esophagogastroduodenoscopy with biopsies 4 wk after the completion of therapy and serial urea breath tests. Eradication at 4 wk was successful in 80 of 96 (83%) patients. On multivariate analysis, H. pylori elimination was associated with advanced age ( p = 0.002) and a greater amount of chronic inflammation on baseline antral biopsy ( p = 0.024). Eradication was inversely associated with the presence of a gastric ulcer ( p = 0.008) and lack of medication compliance ( p = 0.030). Successful eradication reduced the severity of both acute and chronic antral mucosal inflammation. Household income, gender, ethnic group, smoking, alcohol intake, and H. pylori status of the spouse did not differ between the eradicated and noneradicated groups. We conclude that it will be important to control for influential patient factors in future studies of H. pylori treatment regimens.     

Helicobacter pylori infection affects Toll-like receptor 4 expression in human gastric mucosa

BACKGROUND/AIMS: Toll-like receptor 4 (TLR4), which requires a helper molecule, MD-2, is a main receptor for lipopolysaccharide (LPS) from gram-negative bacteria. The expression of TLR4 in H. pylori infection in human gastric mucosa, however, is unclear. The aim of this study was to determine the effect of H. pylori infection on the TLR4 and MD-2 expression in human gastric mucosa. METHODOLOGY: Biopsy samples from the antrum and corpus were obtained from 45 patients (25 patients without H. pylori infection including 5 patients with successful eradication of H. pylori, and 20 patients with H. pylori infection). These samples were used for TLR4, MD-2 mRNA expression study and immunohistochemical study. RESULTS: In patients without H. pylori infection, the expressions of TLR4 and MD-2 were bigger in the corpus mucosa than in the antral mucosa. In patients with H. pylori infection, the expressions of TLR4 and MD-2 significantly increased in the antral and corpus mucosa. Immunohistochemical study revealed similar results as the TLR4 mRNA expression. After the eradication of H. pylori, the expressions of TLR4 and MD-2 were the same levels in both sites as those in patients without H. pylori infection. CONCLUSIONS: The results indicated that H. pylori infection significantly increased TLR4 and MD-2 expressions in the antral and corpus mucosa.     

Decreased expression of epidermal growth factor receptor and mRNA of its ligands in Helicobacter pylori-infected gastric mucosa

BACKGROUND: Epidermal growth factor (EGF) and TGF-alpha play a central role in maintaining gastric mucosal integrity. Little is known about the regulative role of the four other widely expressed epidermal growth factor receptor ligands, heparin-binding EGF, amphiregulin, betacellulin and cripto in the gastric mucosa. METHODS: Nineteen patients with Helicobacter pylori-positive gastritis and 32 healthy controls were investigated. Mucosal mRNA expression of EGF receptor ligands was determined by quantitative PCR before and after H. pylori eradication. PCR products were analyzed by soft laser scanning densitometry. Moreover, the effect of chronic active gastritis on EGF receptor expression was assessed by [125I] EGF receptor autoradiography. Immunohistochemistry was performed for TGF-alpha to localize growth factor expression. RESULTS: Antral and oxyntic biopsies showed strong mRNA expressions for TGF-alpha, amphiregulin and heparin binding EGF, but not for EGF, cripto and betacellulin. mRNA expression was significantly reduced down to 50% in H. pylori infection, significantly lower compared to normal gastric mucosa, and increased after eradication therapy. Moreover, chronic gastritis was associated with decreased antral EGF receptor binding compared to healthy controls, possibly reflecting reduced autoinduction. Immunohistochemical analyses localized TGF-alpha in the cytoplasma of gastric epithelial cells and revealed its increased expression after H. pylori eradication. CONCLUSIONS: The data presented suggest that amphiregulin, heparin binding EGF and TGF-alpha are important EGF receptor ligands in the gastric mucosa. H. pylori infection apparently suppresses their mRNA as well as receptor expression that is reversed by H. pylori eradication. This deficiency of the gastroprotective EGF system may contribute to the gastric pathogenicity of H. pylori infection.     

幽门螺杆菌相关性胃部疾病的病理变迁

目的：探讨幽门螺杆菌（Hp)清除与否与胃黏膜病理转归的关系。方法：191Hp感染的胃炎或溃疡病患者分别随机给予抗Hp或非抗Hp治疗,1年后复查胃镜,病理分型根据悉系统。结果191例患者中,慢性炎症1年后的炎症程度较1年前减轻（P＜0．05）。其中萎缩和肠化生的程度也较前减轻（P＜0．05）,但活性动性炎症和蔼前后比较差异无显著性（P＜0．05）。根据1年后胃镜复查有无Hp清除分为两个队列,Hp清除列有107例,Hp未肖除列有84例,Hp清除列较未清除列1年后慢性炎症程度轻（P＜0．05）活动性炎症者少（P＜0．05）。对不疾病和不同的治疗分层后发现,Hp清除者的胃黏膜炎症程度总是较Hp未清除者轻（P＜0．05）。结论本研究提示,Hp感染与胃黏膜活动性炎症关系较为密切。Hp清除有利于胃黏膜炎症程度的减轻。     

Influences of Helicobacter pylori on cyclooxygenase-2 expression and prostaglandinE2 synthesis in rat gastric epithelial cells in vitro

BACKGROUND AND AIM: It is known that cyclooxygenase (COX)-2 is over expressed in gastrointestinal neoplasia and Helicobacter pylori (H. pylori) infection is causally linked to gastric cancer. The present study aimed to elucidate the effects of H. pylori on COX-2 expression and prostaglandinE(2) (PGE(2)) production in a gastric epithelial cell line derived from normal rat gastric mucosa (RGM1). METHOD: H. pylori water extracts were prepared from a supernatant of the H. pylori suspension in distilled water. RGM1 cells were cultured with H. pylori water extracts at the final concentration of 2.5, 5, 10 microg/mL for 24 h. For the time sequence study, RGM1 cells were cultured with 10 microg/mL H. pylori water extracts for 0, 6, 12, 24 and 48 h. COX-1 and COX-2 expression in the RGM1 cells was analyzed by western blotting. The levels of PGE(2) in the cultured media were measured by enzyme immunoassay. RESULTS: H. pylori did not affect COX-1 expression; whereas COX-2 expression increased by six-fold at 24 h after incubation of RGM1 cells with 10 microg/mL H. pylori water extracts. The increase in COX-2 expression was evident after 12 h of incubation; reached a peak at 24 h and declined at 48 h. H. pylori dose dependently increased COX-2 expression and PGE(2) synthesis in RGM1 cells. CONCLUSION: H. pylori induces COX-2 expression and increases PGE(2) synthesis in RGM1 cells in vitro. These results indicate that H. pylori-associated gastric carcinogenesis may depend on COX-2 expression.     

萎缩性胃炎患者幽门螺杆菌根除后表皮生长因子及其受体的变化

目的　研究幽门螺杆菌 (Helicobacterpylori,H .pylori)感染对胃黏膜表皮生长因子受体 (epidermalgrowthfactorreceptor ,EGFR)、血清表皮生长因子 (epidermalgrowthfactor,EGF)水平的影响。方法　对 60例H pylori检测阳性的慢性萎缩性胃炎患者进行根除治疗 ,在治疗前及疗程结束 3个月后分别进行胃镜检查 ,并采用免疫组化及放射免疫法测定H pylori根除前后胃黏膜EGFR和血清EGF含量。 3 0例H pylori检测阴性且胃镜检查无明显异常者作为正常对照组。结果　 60例H pylori检测阳性的CAG患者的胃黏膜EGFR阳性率及血清EGF水平均高于正常对照 ,其差异有显著性 (P <0 0 5 ,P <0 0 1)。有 3 1例在根除治疗 3个月后进行了复查 ,其中 2 4例H pylori得到成功根除。 2 4例H pylori得到根除的CAG患者 ,根除后血清EGF水平明显下降 (P <0 0 1) ,而EGFR阳性率无改变 (P >0 0 5 )。结论　H pylori感染引起胃黏膜EGFR阳性率及血清EGF水平增加 ,根除H pylori后血清EGF可恢复至正常水平 ,而胃黏膜EGFR阳性率在短期内没有明显改变     

Gastric MALT-lymphoma,gastrin and cyclooxygenases

Malt-lymphoma, gastrin and COX-2 interaction. Low grade, mucosal associated lymphoid tissue (MALT)-lymphoma is an unique among gastric malignancies where causal involvement of Helicobacter pylori (H. pylori) infection has been proposed based on complete regression of the tumor following the eradication therapy. In this report ten primary, low-grade MALT-lymphomas have been examined before and 6 months after one week of successful eradication therapy (clarithromycin + amoxicillin + omeprazole). Gastric biopsy samples from tumor and intact antrum and corpus mucosa were obtained during endoscopy before and after eradication for assessment of expression of gastrin and gastrin receptor (CCKB-R) as well as cyclooxygenase (COX)-1 and COX-2 using RT-PCR. The gastric lumen and serum gastrin and mucosal and tumor tissue PGE2 biosynthesis were determined by RIA before and after H. pylori eradication. Eradication of H. pylori resulted in complete endoscopic and histological remission of MALT-lymphoma in 9 out of 10 patients as assessed 6 months after this eradication. Before eradication, the mRNA expression for gastrin and CCKB-R as well as mRNA expression for COX-1 and COX-2 were observed in tumor tissue and infected mucosa, while corpus mucosa expressed only CCKB-R and antrum mucosa only gastrin. Six months upon the eradication when MALT-lymphoma completely regressed both endoscopically and histologically in 9 of 10 tested subjects, the expression of gastrin and COX-2 disappeared from the former area of MALT-lymphoma tumor. Gastrin mRNA remained detectable only in antrum mucosa, CCKB-R mRNA in corpus mucosa and COX-1 mRNA both in antrum and corpus mucosa. Gastric luminal and serum gastrin levels and gastric mucosa and tumor PGE2, which were greatly elevated before eradication, became normalized after this procedure. This study demonstrates that low-grade MALT-lymphoma is linked to H. pylori infection which may promote the expression and excessive release of gastrin and COX-2 expression that could be involved in the pathogenesis of MALT-lymphoma.