Acute and chronic infection of H. pylori caused the difference in apoptosis of gastric epithelial cells.

Helicobacter pylori (H. pylori) is one of the most important pathogenic bacteria associated with various gastrointestinal diseases. At present, its apoptotic or antiapoptotic mechanism on gastric epithelial cells remains unknown and needs further illustrated. In this study, acute infection model (H. pylori and GES-1 cells were co-cultured for 24 h at a multiplicity of infection MOI of 100:1) and chronic infection model (GES-1 cells were infected repeatedly every 24 h at a multiplicity of infection MOI of 100:1 for approximately 8 weeks) were established, respectively. the chronic H. pylori infected GES-1 cells underwent a typically morphological change and Western Blot results showed that there was slight decrease in expression of E-cadherin, and obvious increase in expression of Vimentin. Apoptosis of these two models were analyzed by flow cytometry compared with the control cells, meanwhile, apoptosis associated markers (Bcl-xL, Bcl-2, Bax, etc) were detected by Western blot, additional in clinical H. pylori-positive gastric cancer tissues. Results showed that compared with the control cells, acute infection of H. pylori significantly accelerated the apoptosis of GES-1, increased the expression of Bax and Cleaved caspase-3, down-regulated expression of Bcl-xL and Bcl-2. Moreover, an opposite result was found in chronic infection of model and clinical gastric cancer tissues, and enhanced expression of NF-κB p65. Taken together, these findings suggest that H. pylori infection plays differential effects on apoptosis of gastric epithelial cells.

Iatrogenic Gastrointestinal Perforation Following Therapeutic Endoscopic Procedures: Management and Outcome.

The aim of this study was to analyze the location, the cause and treatment of iatrogenic gastrointestinal perforations following therapeutic endoscopic procedures. Perforation occurred in 12 patients out of 3,389, giving cases occurred intraoperatively or postoperatively. Among them, 6 cases were closed by titanium clipping and 1 case by purse string suture. In another case after cap-assisted endoscopic mucosal resection (EMRC), attempted titanium clipping failed, emergency surgery had to be performed. One each case, after Argon plasma coagulation (APC) and case after endoscopic piecemeal mucosal resection (EPMR), recovered well spontaneously. In two cases, titanium clips fell off endoscopic mucosal resection (EMR) resulting in delayed perforation, required surgery. Key factors for preventing and managing the perforation of endoscopic treatment, include the choice of endoscopic approach, processing method of perforation, detail processing in endoscopic therapy, proficient degree of operators and psychological quality.

A lower dose of fluorescein sodium is more suitable for confocal laser endomicroscopy: a feasibility study.

BACKGROUND AND AIMS: Image quality can be guaranteed with the conventional dosage of fluorescein sodium in probe-based confocal laser endomicroscopy (pCLE). However, yellow discoloration of the skin seriously affects daily life and simultaneously increases the risk of adverse events such as allergic reactions. The aim of this study was to test whether a lower dosage of fluorescein sodium can provide satisfactory image quality and to compare the diagnostic accuracy of gastric intestinal metaplasia (GIM) through a randomized blind controlled trial. METHODS: Consecutive patients were randomly assigned to different doses of fluorescein sodium. Image quality was determined by the endoscopists' subjective assessments and signal-to-noise ratio (SNR) assessment systems. Skin discoloration was tested using a neonatal transcutaneous jaundice detector. In addition, consecutive patients with a known or suspected diagnosis of GIM were examined by pCLE with the lower dose and the traditional dose. RESULTS: Only 0.01 mL/kg dose of 10% fluorescein sodium led to a significant decrease in image quality (P < .05), and a dose of 0.02 mL/kg had the highest SNR value (P < .05). There were no significant differences in skin discoloration between the 0.01 mL/kg and 0.02 mL/kg doses (P = .148) and no statistical difference in the diagnostic accuracy of pCLE for GIM between the 0.02 mL/kg and 0.10 mL/kg doses (P > .05). The kappa values for the correlation between pCLE and histopathology were 0.867 (95% confidence interval, 0.782-0.952) and 0.891 (95% confidence interval, 0.811-0.971). CONCLUSIONS: The 0.02 mL/kg dose of 10% fluorescein sodium seems to be the best dose for pCLE in the upper GI tract, with comparable image quality with the conventional dose and insignificant skin discoloration. This dose is also very efficient for the diagnosis of GIM.

Biological function of hpsh4590 localized in the plasticity zone of Helicobacter pylori.

The aim of this study was to determine the biological function of hpsh4590 in Helicobacter pylori. After Hpsh4590 was expressed using a prokaryotic expression system, the cytotoxic effects and IL-8 production of Hpsh4590 were analyzed by co-culturing with GES-1 cells. Meanwhile, the antibody of rHpsh4590, produced by immunizing rabbit, was used for localization and protein interaction studies. Hpsh4590 fusion protein was expressed successfully in Escherichia coli Rosetta (DE3), and the polyclonal antibody was produced at high titers. The MTT assay showed that the inhibition ratio of GES-1 cells cultured with 0.1 µg/mL rHpsh4590 (3.02% ± 0.02%) was significantly lower than that of 20 µg/mL rHpsh4590 (57.57% ± 0.03%, p < 0.01), while DAPI staining showed the cytotoxic effects of rHpsh4590 for GES-1 cells. The up-regulation of cleaved caspase-3 and cleaved PARP was observed after GES-1 cells co-cultured with rHpsh4590 by Western blot. Co-culturing of GES-1 cells with rHpsh0459 (20 µg/mL) led to significant production of IL-8 at 12 h(1097.74 ± 212.37 pg/mL) and 24 h (1379.55 ± 209.58 pg/mL) then at 6 h(134.68 ± 14.64 pg/mL, p < 0.01). These observations suggest that the cytotoxicity of Hpsh4590 occurred in a concentration dependent manner, which is related with IL-8 secretion from gastric mucosal epithelial cells. Hpsh4590 was found localized in the membrane and the periplasm of H. pylori, interacted with zinc finger protein and methionine ABC transporter ATP-binding protein, and potentially regulates DNA uptake or transfer.

A comparison of endoscopic submucosal dissection (ESD) and radical surgery for early gastric cancer: a retrospective study.

BACKGROUND: Endoscopic submucosal dissection (ESD) has become one of the mainstays of treatment for early gastric cancer (EGC). Radical surgery is also a classical treatment method for EGC. There have been no systematic clinical studies of the curative effects and adverse events associated with ESD vs. radical surgery for EGC. This study investigated the therapeutic efficacy and safety of ESD and radical surgery for EGC. METHODS: Twenty-nine patients with EGC underwent ESD, and 59 underwent radical surgery at Weihai Municipal Hospital. The pathological characteristics, postoperative outcomes, hospital course, morbidity and mortality were retrospectively compared between the two groups. RESULTS: The oncological clearance was 93.1 % (27/29) in the ESD group. Postoperative delayed haemorrhage occurred in two patients. The hospital stay ranged from 10 to 23 days, and the average stay was 14.3 ± 3.7 days. The patients were followed-up for 1 to 5 years, with a mean follow-up of 26.9 ± 8.5 months. Regular endoscopic examinations showed that the wound had healed with no cancer recurrence in all of the patients. In the radical surgery group, the oncological clearance was 100 % (59/59). The hospital stay ranged from 11 to 55 days, and the average stay was 21.7 ± 9.3 days. The patients were followed-up for 1 to 3.7 years, with a mean follow-up of 22.3 ± 9.4 months. Nine patients developed complications, including acute postoperative adhesive ileus (1/59) and symptomatic residual gastritis (3/59). These complications were improved by an additional operation, drainage, gastrointestinal decompression and comprehensive therapy. CONCLUSIONS: ESD achieved similar efficacy and had many advantages compared with radical surgery for the treatment of EGC.

Helicobacter pylori virulence factors in development of gastric carcinoma.

Helicobacter pylori plays a vital role in the pathogenesis of gastric carcinoma. However, only a relatively small proportion of individuals infected with H. pylori develop gastric carcinoma. Differences in the incidence of gastric carcinoma among infected individuals can be explained, at least partly, by the different genotypes of H. pylori virulence factors. Thus far, many virulence factors of H. pylori, such as Cag PAI, VacA, OMPs and DupA, have been reported to be involved in the development of gastric cancer. The risk of developing gastric cancer during H. pylori infection is affected by specific host-microbe interactions that are independent of H. pylori virulence factors. In this review, we discuss virulence factors of H. pylori and their role in the development of gastric carcinoma that will provide further understanding of the biological interactions of H. pylori with the host.

Helicobacter pylori with the Intact dupA Cluster is more Virulent than the Strains with the Incomplete dupA Cluster.

The duodenal ulcer promoting gene (dupA), located in the plasticity region of Helicobacter pylori (H. pylori), is predicted to form a type IV secretory system (T4SS) with vir genes around dupA. In the study, we investigated the association between the dupA cluster status and the virulence of H. pylori in a littoral region of Northeast China. Two hundred and sixty-two H. pylori strains isolated from the chronic gastritis were examined to evaluate the dupA cluster status, cag PAI genes and vacA genotype using PCR and Western blot. Histopathologic evaluations of biopsy specimens were performed to analysis the association between the dupA cluster and the inflammatory response. IL-8 productions in gastric mucosa and from GES-1 cells co-cultured with H. pylori were measured, respectively, to analysis the association between the dupA cluster status and IL-8 production. We found that gastric mucosal inflammatory cell infiltration was significantly higher in patients with dupA-positive H. pylori, including H. pylori with complete dupA cluster (2.71 ± 0.79) and incomplete dupA cluster (2.09 ± 0.61) than in patients with dupA-negative strain (1.73 ± 0.60, p < 0.01), whereas no significant difference in the gastric mucosal atrophy was found according to the status of dupA cluster. Gastric mucosal IL-8 levels were higher in the complete dupA cluster group than in other groups (p < 0.01), and IL-8 production from GES-1 cells was also significantly higher in strains with a complete dupA cluster (1527.9 ± 180.0 pg/ml) than in those with an incomplete dupA cluster (1229.4 ± 75.3 pg/ml, p < 0.01) or those with dupA negative (1201.9 ± 92.3 pg/ml, p < 0.01). In conclusion, the complete dupA cluster in H. pylori is associated with inflammatory cell infiltration and IL-8 secretion, and H. pylori strain with a complete dupA cluster seems to be more virulent than other strains with the incomplete dupA cluster or dupA negative.

CagA status & genetic characterization of metronidazole resistant strains of H. pylori from: A region at high risk of gastric cancer.

OBJECTIVE: The aim of study was to determine relationship between cagA and genetic characterization of metronidazole (MTZ) resistant H. pylori strains from a region at high risk of gastric cancer. METHODS: 172 H. pylori strains were isolated from the patients with dyspeptic symptoms, and antimicrobial susceptibility testing for MTZ was assessed by E-test. rdxA and frxA genes were amplified using PCR among the MTZ resistant isolates. The status of the plasmid and classes 1～3 integrons were investigated in all isolates. RESULTS: MTZ was detected in 88 isolates (51.16%). Variations in the rdxA gene leading to alterations of amino acids in RdxA proteins were identified in all MTZ resistant strains. FrxA contained missense alterations in 55 MTZ resistant isolates, while the premature truncation of FrxA was caused by frameshift mutations in 9 MTZ resistant strains. Plasmid was found in one MTZ sensitive strain (0.58%), and none of Class 1～3 integrases gene was detected in the studied isolates. The conservative cagA fragment was obtained from all clinical isolates of H. pylori. The sequence of cagA 3' variable region in 164 strains were obtained, including East Asian-type (122, 74.39%) and Western-type (42, 25.61%). Prevalence of Western-type cagA 3' variable region was significantly higher in MTZ resistant (33.73%, 28/83) than those of MTZ-sensitive strains (17.28%, 14/81) (p=0.02). CONCLUSION: A high prevalence of MTZ resistance was found in the region, and bacterial chromosome mutations in the rdxA and frxA gene still contribute to the high-level MTZ resistance. H. pylori strains characterized with West-type cagA 3' variable region tend to acquire MTZ resistance in the region.

Distribution of Helicobacter pylori virulence markers in patients with gastroduodenal diseases in a region at high risk of gastric cancer.

ABSTRACT BACKGROUND: Helicobacter pylori (H. pylori) is a major human pathogen that is responsible for various gastroduodenal diseases. We investigated the prevalence of H. pylori virulence markers in a region at high risk of gastric cancer. METHODS: One hundred and sixteen H. pylori strains were isolated from patients with gastroduodenal diseases. cagA, the cagA 3' variable region, cagPAI genes, vacA, and dupA genotypes were determined by PCR, and some amplicons of the cagA 3' variable region, cagPAI genes and dupA were sequenced. RESULTS: cagA was detected in all strains. The cagA 3' variable region of 85 strains (73.3%) was amplified, and the sequences of 24 strains were obtained including 22 strains possessing the East Asian-type. The partial cagPAI presented at a higher frequency in chronic gastritis (44.4%) than that of the severe clinical outcomes (9.7%, p < 0.001). The most prevalent vacA genotypes were s1a/m2 (48.3%) and s1c/m2 (13.8%). Thirty-six strains (31.0%) possessed dupA and sequencing of dupA revealed an ORF of 2449-bp. The prevalence of dupA was significantly higher in strains from patients with the severe clinical outcomes (40.3%) than that from chronic gastritis (20.4%, p = 0.02). CONCLUSION: The high rate of East Asian-type cagA, intact cagPAI, virulent vacA genotypes, and the intact long-type dupA may underlie the high risk of gastric cancer in the region.

Endoscopic ultrasonography in tandem with endoscopic retrograde cholangiopancreatography in the management of suspected distal obstructive jaundice.

GOALS: To examine the benefits and feasibility of endoscopic ultrasonography (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) in tandem for distal obstructive jaundice. MATERIALS AND METHODS: From September 2007 to August 2012, patients with suspected distal obstructive jaundice were randomized to single-session EUS-ERCP (group A), EUS, and ERCP in different sessions (group B), and an ERCP-only procedure (group C). Data were prospectively collected on the following parameters: ERCP-avoided, duration of procedure, the dose of propofol, complications, and diagnostic yield. RESULTS: A total of 180 patients were divided randomly into 60 patients in group A, 60 in group B, and 60 in group C. A total of four therapeutic ERCP were canceled after EUS. The ERCP procedural time in group A was shorter, although not significantly different from that in group B (group A vs. group B: 41.24±7.57 vs. 43.38±6.57 min; P>0.05), but both were significantly less than that in group C (group C: 49.12±7.46 min; P<0.05). The total procedural time did not differ significantly between group A and group B (70.05±15.35 vs. 73.70±15.12 min; P>0.05), nor were there significant differences in the dose of propofol between them (group A vs. group B: 357.11±115.86 vs. 369.55±133.86 mg; P>0.05). In all, 22 anesthetic complications and 21 endoscopic complications occurred without significant differences among the three groups (P>0.05). CONCLUSION: As a triaging or a screening tool, diagnostic EUS gives added benefit to therapeutic ERCP. EUS and ERCP in a tandem approach are safe and feasible in patients with suspected distal obstructive jaundice.