Colloidal Bismuth Subcitrate (De-Nol) Inhibits Degradation of Gastric Mucus by Campylobacter pylori Protease

There is increased awareness that infection with Campylobacter pylori could be a major factor in the pathogenesis of gastric disease. Here, we present evidence that the extracellular protease elaborated by this bacteria, which causes degradation of gastric mucus, is inhibited by an antiulcer agent, colloidal bismuth subcitrate (CBS; De-Nol). The study was conducted with C. pylori cultured from antral mucosal biopsy specimens of patients undergoing gastroscopy. The grown colonies of bacteria were washed with saline, filtered through sterilization filter, dialyzed, and lyophilized. The powder was used as the enzyme source for proteolytic activity assay employing pig gastric mucus as substrate. Optimum enzymatic activity was obtained at 37 degrees C and at pH 7.0. The apparent Km of C. pylori protease with gastric mucus was 0.71 g/L. Analyses of the degradation products indicated that the protease caused extensive proteolysis of mucus glycoprotein polymer. Introduction of CBS to the incubation mixtures led to a reduction of the rate of mucus degradation. The rate of proteolysis inhibition was proportional to CBS concentration up to 1 X 10(-1) g/L, at which point a 37% reduction in mucus proteolysis was obtained. The Km value for proteolytic degradation of mucus by C. pylori protease in the presence of CBS was 1.25 g/L. The results suggest that CBS is capable of counter-acting the proteolysis of the protective gastric mucus layer by C. pylori.     

Inhibition of Gastric Mucosal Laminin Receptor by Helicobacter pylori Lipopolysaccharide: Effect of Sucralfate

The maintenance of gastric mucosal integrity depends upon the interaction involving specific cell surface receptors with distinct proteins of extracellular matrix, one of which is laminin. We present here evidence that lipopolysaccharide from Helicobacter pylori interferes with laminin binding on the receptor. The laminin receptor was isolated from gastric epithelial cell membrane by the procedure involving membrane solubilization with octylglucoside followed by affinity chromatography on laminin-coupled Sepharose. The receptor protein yielded on SDS-PAGE a single 67 kDa band. After radioiodination, the protein was incorporated into liposomes which displayed specific affinity toward laminin-coated surface. The binding of liposomal receptor to the laminin-coated surface was inhibited by lipopolysaccharide from H. pylori. The inhibitory effect was proportional to the concentration of lipopolysaccharide up to 50 micrograms/ml, at which a 96% decrease in binding occurred. Introduction of sucralfate to the assay system led to the prevention of the inhibitory effect of lipopolysaccharide on the receptor-laminin binding. The effect was dose dependent and, at sucralfate concentration of 45 micrograms/ml, nearly complete restoration in binding was achieved. The results suggest that H. pylori also may be capable of disrupting the gastric mucosal integrity through a similar mechanism in vivo, and that anti-ulcer drug sucralfate counteracts this effect.     

Sulglycotide Effect on the Proteolytic and Lipolytic Activities of Helicobacter pylori toward Gastric Mucus

Objectives : Infection with Helicobacter pylori is now recognized as a major factor in the etiology of gastric disease, and among the detrimental efTects this bacterium exerts on the mucosal integrity is the elaboration of extracellular protease and lipase enzymes capable of mucus protein and lipids degradation. We present here evidence that the activities of these enzymes are inhibited by an gastroprotective agent, suiglycotide. Methods : The grown colonies of bacterium were washed witb saline, filtered through sterilization filter, and tbe filtrate used as the enzyme source. Results : In the absence of suiglycotide, the H. pylori protease caused extensive degradation of human gastric mucus, wbile free fatty acids, glycerol monooleate and lysopbosphatidylcholine were produced by the action of H. pylori lipase and phospholipase A enzymes. Introduction of suiglycotide to the incubation systems led to the reduction in the rate of mucus protein and lipid degradation. Tbe rate of proteolysis inbibition was proportional to suiglycotide concentration up to 45 μg/ml, at which point a 43% reduction in mucus degradation was attained, whereas the maximum inhibition of lipase (39%) and phospbo- Upase A (98%) activities occurred at a suiglycotide concentration of IOO fxg/ml. Conclusions: This study indicates that suiglycotide is capable of counteracting the mucolytic activity of H. pylori and tbus may be of value in tbe therapy of H. pylori-associated gastric diseases.     

Glycosulfatase Activity of H. pylori toward Human Gastric Mucin: Effect of Sucralfate

Colonization of gastric mucosa by Helicobacter pylori, a bacterium implicated in the etiology of gastric disease, involves the cell surface sulfated glycosphingolipid receptors for the attachment. Evidence has also been obtained recently that sulfated mucus glycoproteins have the ability to interfere with this process. Here, we show that H. pylori displays glycosulfatase activity, and report the specificity of this enzyme toward gastric mucosal sulfated glycoproteins and glycolipids. With 35S-labeled human gastric sulfated mucin as substrate, the enzyme activity was identified in the extracellular material elaborated by the bacterium. The glycosulfatase exhibited maximum activity at pH 5.7 in the presence of Triton X-100 and CaCl2, and gave on SDS-PAGE a protein band of 30 kDa. Specificity studies revealed that the enzyme effectively caused desulfation of N-acetylglucosamine-6-sulfate and galactose-6-sulfate present in carbohydrate chains of gastric mucins, as well as that of glucose-6-sulfate, a constituent of mucus glyceroglucolipids. However, the H. pylori glycosulfatase was ineffective toward galactosyl- and lactosylceramide sulfates which serve as receptors for this bacterium attachment and contain the sulfate ester group at C-3 of galactose. The glycosulfatase activity toward human sulfated gastric mucin was inhibited by sucralfate. The inhibitory effect was proportional to the concentration of sucralfate up to 120 micrograms/ml, at which a 78% decrease in mucin desulfation occurred. The results demonstrate that H. pylori, through its glycosulfatase activity, affects the sulfated mucin and glyceroglucolipid content of the protective mucus layer, and that antiucler drug sucralfate is able to counteract the detrimental action of this enzyme.     

幽门螺杆菌对人胃癌细胞株AGS侵袭力的影响

背景：幽门螺杆菌（H．pylori）为人类胃癌的Ⅰ类致癌原,但其在胃癌演进中的作用仍未完全阐明。目的：体外观察Hpylori对人胃癌细胞株AGS侵袭力的影响。方法：将AGS细胞与H．pylori标准菌株NCTC11637共培养72h．光学显微镜观察12—72h时细胞形态变化,扫描电镜观察24h时细胞形态变化。侵袭小室实验检测共培养24h后AGS细胞的侵袭力。结果：AGS细胞与H．pylori共培养12h后,细胞渐出现变形,伪足增多、伸长．24h和48h时细胞间相互离散,伸出细长伪足,呈“蜂鸟”表型,60h和72h时细胞出现空泡样变,死亡逐渐增多;扫描电镜下可见Hpylori黏附于AGS细胞表面,细胞变形明显,伸出细长伪足。侵袭小室实验显示与H．pylori共培养24h的AGS细胞,每200倍视野下穿膜细胞数显著高于PBS对照组（130．4±11．5对87．1±9．3．P〈0．01）。结论：Mpylori感染可影响人胃癌细胞株AGS的细胞形态,增加细胞侵袭力。     

Different Effect of Helicobacter pylori on the Human Gastric Antral and Body Mucosal Intracellular Mucin

To elucidate the role of Helicobacter pylori infection in the pathogenesis of gastric ulcer, we investigated the intracellular mucin content by measuring the periodic acid-Schiff-Alcian blue (PAS-AB)-stained substances, by means of computer, in the biopsy sample of gastric mucosa from patients with and without H. pylori intection. In the antral mucosa the intracellular PAS-AB-stained mucin content was significantly smaller in patients with infection than in patients without infection, whereas in the oxyntic gland mucosa the intracellular mucin content showed no significant change between patients with and without infection. In an animal study we investigated the effect of ammonia, which might be produced by H. pylori in the presence of urea. The ammonia, administered orally, caused a greater decrease of intracellular PAS-AB-stained mucin content in the gastric antral mucosa than in the body mucosa, in a dose-dependent manner. The results suggested that H. pylori infection had a different effect on the gastric mucosal intracellular PAS-AB-stained mucin and lowered specifically the antral intracellular PAS-AB-stained mucin content, possibly due to generation of ammonia by H. pylori.     

幽门螺杆菌感染对胃上皮细胞凋亡的影响

本文采用切口末端标记方法前瞻性观察了16例正常胃牯膜标本和31例幽门螺杆菌阳性胃炎患者抗幽门螺杆菌治疗前后胃窦部上皮细胞凋亡的变化。结果表明,幽门螺杆菌感染者的凋亡指数(0.7044)明显高于正常对照者(P<0.005);幽门螺杆菌根除后凋亡指数由0.7624降至0.1159(P<0.005),而持续阳性者则无明显降低;凋亡指数与胃炎程度无关。提示幽门螺杆菌能促进胃上皮细胞凋亡,这可能是幽门螺杆菌引起胃癌和溃疡的重要机理。     

Effects of Cytokines, Without and with Helicobacter pylori Components, on Mucus Secretion by Cultured Gastric Epithelial Cells

Cytokines are suspected to play a crucial rolein the pathogenesis of Helicobacter pylori associatedgastric diseases. Hence, considerable attention has beenpaid to the actions of cytokines on gastric cells. We examined the effects of cytokines onmucus secretion by gastric epithelial cells, without orwith H. pylori components. Mucus secretion by culturedgastric epithelial cells was assessed as secretion of [³H]glucosamine-prelabeledhigh-molecularweight glycoproteins. Interleukin(IL)-1 and IL-6 significantly stimulated mucussecretion, but other cytokines such as IL-7, IL-8,IL-10, interferon (IFN)- and tumor necrosis factor (TNF)- had noeffect. H. pylori lysate caused a decrease in both basaland stimulated secretion of mucus. In addition,IFN- significantly potentiated the lysate-induced reduction of basal and stimulated secretion.Cell viability was not affected by any of treatments.These results indicate that IL-1 and IL-6stimulate mucus secretion, while IFN- potentiatesH. pylori-decreased secretion by gastric epithelialcells.     

根除幽门螺杆菌对胃黏膜病变的影响

幽门螺杆菌（H.pylori）被认为是导致胃黏膜病变的重要因子，根除H.pylori能使胃黏膜病变改善。目的：观察根除H.pylori对胃黏膜病变的影响。方法：予100例经胃镜和组织病理学检查确诊为萎缩性胃炎伴H．pylori感染患者抗H.pylori治疗，1年后复查胃镜和组织病理学，评定组织学变化。结果：所有患者均有不同程度的活动性炎症和慢性炎症。抗H.pylori治疗后，86例被根除。与根除前相比，根除后慢性炎症、活动性炎症、腺体萎缩程度评分均明显下降（P〈0．01），肠化生评分无显著改善。结论：根除H.pylori对胃黏膜病变具有临床治疗意义。     

Effect of Helicobacter pylori Infection on Gastric Juice pH

Background: How Helicobacter pylori infection affects gastric acid secretion is still unclear. Methods: Gastric juice pH, ammonia concentration in gastric juice, serum gastrin level, and grade of gastritis in accordance with the Sydney System were determined for patients with gastric ulcer (GU) and duodenal ulcer (DU) before and after treatment with lansoprazole and amoxicillin, and results were compared with those of H. pylori-negative controls. Results: Scores for H. pylori density, atrophy, metaplasia, and activity of gastritis in the corpus were higher in patients with GU, especially those with proximally located GU, than in those with DU. Gastric juice pH was significantly higher in GU patients than in DU patients and controls. After H. pylori eradication, gastric juice pH and serum gastrin levels in both GU and DU patients were significantly decreased to control levels. In patients without eradication, no significant changes in these factors were observed. Conclusions: These findings suggest that H. pylori infection and gastritis in the corpus suppress acid secretion and increase gastric juice pH, resulting in hypergastrinemia, and that eradication of H. pylori normalizes acid secretion and serum gastrin levels.     

Effects of Sucralfate and Sulglycotide Treatment on Active Gastritis and Helicobacter pylori Colonization of the Gastric Mucosa in Non-Ulcer Dyspepsia Patients

We conducted a double-blind randomized treatment study on patients affects by non-ulcer dyspepsia in whom multiple biopsy specimens showed active gastritis. Patients were given either 3 g/day of sucralfate (n = 39) or 600 mg/day of sulglycotide (n = 50) for 6 wk, a glycopeptide isolated from pig duodenum constituents. Endoscopy was carried out at baseline and at the end of treatment. We took biopsies from the gastric body (twice) and antrum (six times) at each endoscopy in order to determine grade and extent of gastritis and Helicobacter pylori colonization. Both treatments induced a marked regression of active gastritis (sucralfate group: p less than 0.05 and p less than 0.0001, respectively, in body and in antrum; sulglycotide group: p less than 0.01 and p less than 0.001, respectively). Conversely, Helicobacter pylori colonization remained unchanged at the end of the treatments. At baseline, a close relationship was found between grade of active inflammation in each biopsy and Helicobacter pylori density. After therapy, the association was lost in each treatment group. These results suggest that there can be a remission of active gastritis in patients with non-ulcer dyspepsia even without changes in Helicobacter pylori colonization. This result can be achieved by enhancing the protective properties of the gastric mucosa.     

Helicobacter pylori Infection Influences Tumor Growth of Human Gastric Carcinomas

Background: Helicobacter pylori infection is considered a risk factor for gastric carcinoma. However, the effect of eradication therapy in gastric carcinoma patients is not well known. The aim of this study was to investigate the relationship between H. pylori infection and tumor growth of gastric carcinoma. Methods: Fifty-one patients with gastric carcinoma participated in the study. Thirty-three were H. pylori-positive, 6 were H. pylori-negative, and 12 were diagnosed with gastric carcinoma after eradication of H. pylori. To investigate tumor growth of gastric carcinoma, cell proliferation and angiogenesis of the tumors were evaluated by immunohistochemical techniques using Ki-67 and CD34. Results: The Ki-67 labeling index was 47.9?±?2.6 (mean?±?s) in the H. pylori-positive group, 38.1?±?3.6 in the H. pylori-eradicated group, and 22.2?±?5.5 in the H. pylori-negative group. It was significantly lower in the H. pylori-eradicated and H. pylori-negative groups than in the H. pylori-positive one, and a significant difference was also found between the H. pylori-positive and H. pylori-eradicated groups. The microvessel counts were 62.5?±?3.0, 50.2?±?4.0, and 66.0?±?9.8 in the positive, eradicated, and negative groups, respectively. A significant difference was found between the H. pylori-positive and H. pylori-eradicated groups. Conclusion: Our results suggest that H. pylori infection is associated with cell proliferation, and its eradication may influence tumor vascularity of gastric carcinoma. Therefore, H. pylori eradication therapy may contribute to the suppression of tumor growth.     

幽门螺杆菌感染对胃粘膜上皮细胞增殖的影响

目的观察幽门螺杆菌(H.Pylori)感染者,特别是vacAs1a型菌株感染者胃粘膜上皮细胞的增殖情况.方法取84例慢性浅表性胃炎(CSG)和16例十二指肠溃疡(DU)患者的胃窦粘膜标本检测H.Pylori,用溴脱氧尿苷掺入免疫组化法标记S期细胞并计算增殖标记指数(LI),用聚合酶链反应(PCR)检测vacAs1a基因.结果H.Pylori阳性患者的胃粘膜上皮细胞增殖LI为6.14%±1.21%,显著高于H.pylori阴性者(2.43%±0.61%,P＜0.001).vacAs1a阳性者的LI为8.00%±1.46%,显著高于vacAs1a阴性者(4.51%±0.86%,P＜0.05)和H.pylori阴性者(P＜0.001).H.Pylori感染、胃粘膜上皮细胞增殖LI与胃粘膜炎症程度三者高度相关,而炎症程度与vacA类型无关.结论H.pylori感染者的胃粘膜上皮细胞增殖LI明显高于H.pylori阴性者;vacAsla型H.Pylori菌株和炎症程度是胃粘膜上皮细胞增殖的独立影响因素.     

Effect of Helicobacter pylori Eradication on 24-Hour Gastric pH and Duodenal Gastric Metaplasia

Published data on the regression of the extent of duodenal gastric metaplasia (DGM) after the eradication of Helicobacter pylori infection and the normalization of the organism-induced alterations in gastric physiology are scanty and controversial. Therefore, we decided to assess the circadian pattern of gastric acidity and the degree of DGM before and one year after H. pylori eradication in a group of duodenal ulcer patients. Fifteen consecutive H. pylori-positive patients with endoscopically proven duodenal ulcer were recruited for this study. The diagnosis of H. pylori infection was based on CLO-test and histology, and DGM was assessed on four bulb biopsies taken before and one year after H. pylori eradication. At the same time, gastric pH was measured by 24-hr continuous intraluminal recording. H. pylori eradication was ascertained by means of concomitant negative CLO-test and histology performed both four weeks after the end of the eradicating treatment and at the one-year endoscopic control. After successful cure, all patients discontinued any antiulcer medication. The mean 24-hr gastric pH was 1.7 ± 0.4 before and 1.6 ± 0.4 after one year of H. pylori eradication (P = 0.75). DGM improved in three cases, worsened in four cases, and was unchanged in eight cases at the one-year control (P = 0.87). No correlation was found between 24-hr gastric pH and DGM (P = NS) both at baseline and one year after eradication. Our results show that neither circadian gastric acidity nor DGM change significantly one year after H. pylori eradication in duodenal ulcer patients. Thus, the disappearance of H. pylori infection does not determine any increase in gastric pH and any reversal of gastric-type epithelium in the duodenum.     

Immunological Rapid Urease Test for Detecting Helicobacter pylori: Comparative Study of Biopsy Specimens and Gastric Mucus

Abstract: A variety of reliable methods are available for the detection of H. pylori during upper gastrointestinal endoscopy. We evaluated the clinical utility of an analyzer for H. pylori urease composed of a solid-phase tip coated with a monoclonal antibody against H. pylori urease and ion-sensitive field effect transistor-based pH sensor system. Samples of both gastric mucus and gastric mucosal specimens were collected and the results from this system were compared. Sensitivity and specificity were 97% and 100% for mucus samples and 92% and 97% for mucosal specimens in the present system; compared to 95% and 96% for histological examination, 92% and 100% for bacteriological test, and 89% and 100% for rapid urease test, respectively. These results confirmed that the present system had high clinical sensitivity and specificity, especially for testing of mucus samples. This method has the advantage of requiring only one sample per patient because mucus can be collected from a broad area of the stomach lumen by stroking the mucosal surface with a brush. (Dig Endosc 1999; 11: 42–46)     

幽门螺杆菌感染对胃黏膜病理变化的影响

背景：幽门螺杆菌(H．pylori)感染已被公认为慢性胃炎和消化性溃疡的重要危险因素，根除H．pylori能加速消化性溃疡的愈合，但其对胃黏膜病理变化的影响尚有待进一步探索。目的：了解根除H．pylori对慢性胃炎胃黏膜病理变化和癌前状态的影响。方法：采用多中心随机对照临床试验和回顾性队列研究，样本选自胃癌高发区：上海郊区的金山区和奉贤区。共纳入360例经内镜检查证实有H．pylori感染的慢性胃炎伴或不伴十二指肠溃疡患者，随机分为两组。治疗组用三联疗法(质子泵抑制剂或Hz受体阻滞剂加两种抗生素)治疗，对照组单纯慢性胃炎患者予西沙必利、十二指肠溃疡患者予西米替丁治疗。在第1年和第4年末随访胃镜，根据H．pylori是否根除将患者分为两组：H．pylori阳性组和H．pylori阴性组。所有胃黏膜活检标本由两位病理科医师统一复读。结果：至第4年末，有120例患者完成全部随访，其中H．pylori持续根除组54例，阳转组5例；H．pylori持续未根除组45例，阴转组16例。持续根除组第1年随访时，活动性炎症比例减少(P＜O．05)；第4年随访时，慢性炎症和肠化程度以及活动性炎症比例减少(P＜O．05)。持续未根除组第1年随访时，慢性炎症程度增加(P＜O．05)；第4年随访时，慢性炎症和肠化程度以及活动性炎症比例增加(P＜O．05)，萎缩程度较第1年随访时增加(P＜O．05)。结论：根除H．pylori可以减轻慢性胃炎的炎症程度，防止肠化的发生和发展。     

The Distribution of Helicobacter pylori in Human Gastric Mucosa in vivo

Abstract: To estimate the distribution of Helicobacter pylori in human gastric mucosa in vivo, the phenol red dye spraying endoscopy lias been successfully developed and is performed after an oral and/or intravenous premedication of famotidine 20mg. This technique was conducted on 25 patients with chronic, atrophic gastritis, on 21 patients with a gastric ulcer and on 14 patients with duodenal ulcers. The red color changes which occurred on the gastric mucosa were classified into three types; the diffuse staining type, the regional staining type and the patchy staining type. In the chronic gastritis group, the diffuse staining type, the regional staining type and the patchy staining type occurred in 11 patients (44%), 7 patients (28%) and 2 patients (8%), respectively. The remainder of the patients' mucosa was unstained. In addition, the regional staining type occurred most frequently in the gastric ulcer group, while the diffuse staining type was dominant in the duodenal ulcer group. Notably, a recurrent and intractable ulcer was surrounded by regional staining fields in the stomach, and showed a diffuse staining at the antrum of the duodenum. These facts suggest that Helicobacter pylori prevented ulcer healing. This concurs with the results of our previous experimental study which found that the low concentration NH₃ solution, produced by Helicobacter pylori, prevented an acetic acid ulcer healing in rats and resulted from the suppression of the cell kinetics of the regenerative epithelial cells and the fibroblasts in the connective tissues at the ulcer margins.