Wireless esophageal pH capsule for patients with gastroesophageal reflux disease: a multicenter clinical study.

AIM: To investigate the feasibility and safety of pH capsule to monitor pH in patients with gastroesophageal reflux disease (GERD). METHODS: Ninety-one patients with symptoms suggestive of GERD were enrolled in this study, 46 of whom were randomized to the pH capsule group; the remaining 45 patients used the conventional catheter and pH capsule simultaneously. The pH data and traces were recorded via automatic analysis, and capsule detachment was assessed using X-ray images. All of the patients were required to complete a questionnaire regarding tolerance with the capsule. RESULTS: The capsules were successfully attached on the first attempt, and no early detachment of the capsules was observed. Compared to the 24-h pH data recorded with the conventional catheter, the data collected with the pH capsule showed no significant differences in 24-h esophageal acid exposure. The measurements of esophageal acid exposure over 24 h collected with the two devices showed a significant correlation (r(2) = 0.996, P < 0.001). Capsule detachment occurred spontaneously in 89 patients, and 2 capsules required endoscopic removal due to chest pain. The capsule was associated with less interference with daily activity. CONCLUSION: The wireless pH capsule provides a feasible and safe method for monitoring gastroesophageal reflux and therefore may serve as an important tool for diagnosing GERD.

Clinical utility and tolerability of JSPH-1 wireless esophageal pH monitoring system.

BACKGROUND: Wireless esophageal pH monitoring system is an important approach for diagnosis of gastroesophageal reflux disease (GERD), the aim of this study is to test the tolerability and utility of the first wireless esophageal pH monitoring system made in China, and evaluate whether it is feasible for clinical application to diagnose GERD. METHODS: Thirty patients from Department of Gastroenterology of The First Affiliated Hospital of Chongqing Medical University who were suspected GERD underwent JSPH-1 pH capsule. The capsule was placed 5 cm proximal to the squamocolumnar junction (SCJ) by endoscopic determination, the data was recorded consecutively for 48 hours. Then all pH data was downloaded to a computer for analysis. The discomforts reported by patients were recorded. RESULTS: 30 patients were placed JSPH-1 pH capsule successfully and completed 24-hour data recording, 29 patients completed 48-hour data recording. One patient complained of chest pain and required endoscopic removal. No complications and interference of daily activities were reported during data monitoring or follow-up period. 48-hour pH monitoring detected 15 patients of abnormal acid exposure, on day1 detected 9 patients, the difference had statistical significance (P<0.01). Positive symptom index (SI) was identified in 3 patients with normal pH data in both 24-hours. In total, 48-hour monitoring increased diagnosis of GERD in 9 patients. CONCLUSION: 48-hour esophageal pH monitoring with JSPH-1 wireless pH monitoring system is safe, well tolerated and effective. It can be feasible for clinical application to diagnose GERD.

Attenuated Salmonella typhimurium carrying TRAIL and VP3 genes inhibits the growth of gastric cancer cells in vitro and in vivo.

BACKGROUND: Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL) and apoptin (VP3) of chicken anemia virus can selectively induce apoptosis in human tumor cell lines by two different pathways. Salmonella not only delivers functional genes to mammalian cells but also possesses antitumor activity and therefore could be adopted as a novel vector for anticancer therapy. MATERIALS AND METHODS: TRAIL and VP3 genes were cloned into a pBudCE4.1 vector and delivered by attenuated Salmonella typhimurium into gastric cancer cells, and their expression and antitumor effects in nude mice were monitored by Western blot, fluorescence microscopy, MTT assay, TUNEL staining, and immunohistochemistry. RESULTS: pBud-VP3 and pBud-TRAIL-VP3 plasmids were constructed to express TRAIL and apoptin in gastric cancer cells, leading to inhibition of cancer cell proliferation after 48 hours (P < 0.05). TRAIL and VP3 genes in pBudCE4.1 vector were also successfully delivered by attenuated S. typhimurium into gastric cancer cells in vivo, in which both TRAIL and apoptin were expressed. In vivo data indicated that S. typhimurium carring pBud-TRAIL-VP3 induced significant cell growth inhibition and tumor regression (P < 0.05). Moreover, expression of TRAIL and apoptin increased the expression of caspase-3 and caspase-9, resulting in enhanced apoptosis. CONCLUSION: Delivery of TRAIL and VP3 genes by attenuated S. typhimurium can significantly inhibit the growth of gastric cancer cells in vitro and in vivo.

[Overexpression of adiponectin prevents hepatocyte steatosis].

OBJECTIVE: To investigate the effect of adiponectin on hepatocyte steatosis. METHODS: L02 cells were transfected with pEGFP-N1-AdipoQ, a plasmid encoding pEGFP-adiponectin fusion protein, or pEGFP-N1. Lipid droplets in the hepatocytes were observed by oil red staining at 72 h. The contents of TG, FFA and glycerol in hepatocytes were measured. RESULTS: Compared to cells transfected with pEGFP-N1-AdipoQ plasmid, much more lipid droplets were observed in cells transfected with pEGFP-N1 plasmid. TG, FFA and glycerol contents in L02 cells and L02/pEGFP-N1 cells were significantly higher than those in L02/pEGFP-N1-AdipoQ cells. CONCLUSIONS: Overexpression of adiponectin prevent hepatocyte steatosis.

[Anti-tumor effect of eukaryotic expressing plasmid containing soluble tumor necrotic factor-related apoptosis inducing ligand combined with human angiostatin Kringle (1 - 3) genes on human gastric cancer xenografts in nude mice].

OBJECTIVE: To investigate the anti-tumor effect of eukaryotic expressing plasmid containing human angiostatin Kringle (1 - 3) [hAG (K1-3)] combined with soluble tumor necrotic factor-related apoptosis inducing ligand (sTRAIL) genes on human gastric cancer xenografts in nude mice. METHODS: Recombinant plasmids of pBud-hAG and pBud-hAG-TRAIL were constructed by subcloning technique. Twenty nude BALB/c mice were inoculated with human gastric cancer cells of the line BGC-823 subcutaneously into the back. One week later after the appearance of implanted tumors the mice were randomly divided into 4 groups with pBud-hAG, pBud-hAG-TRAIL, pBud blank plasmid, and normal saline (NS) injected into the tumors respectively once the other day for 7 times. The size of tumor was observed. 7 days later the mice were killed with their tumors taken out. RT-PCR was used to detect the expression of hAG and sTRAIL. The microvessel density (MVD) of tumor was observed and recorded by detecting the protein of CD34 with immunohistochemistry on the microscopy. RESULTS: The MVD of tumor in the pBud-hAG-TRAIL and pBud-hAG groups were (4.8 +/- 0.9)/HP and (4.6 +/- 1.2)/HP respectively, significantly lower than those of the pBud and NS groups [(17.4 +/- 2.4)/HP and (18.2 +/- 2.7)/HP respectively, all P < 0.05], but there was no significant difference between the pBud-hAG-TRAIL and pBud-hAG groups. mRNA expression and protein expression of sTRAIL and hAG were positive in the pBud-hAG-TRAIL and pBud-hAG groups. The tumor volumes of tumors of the pBud-hAG-TRAIL and pBud-hAG groups were (1.325 +/- 0.012) cm(3) and (1.862 +/- 0.017) cm(3) respectively, both significantly lower than those of the pBud and NS groups [(3.637 +/- 0.032) cm(3) and (3.521 +/- 0.028) cm(3) respectively, all P < 0.05]. CONCLUSION: Angiostatin inhibits tumor angiogenesis through inhibiting the growth of vascular endothelial cells, and TRAIL induces tumor cell apoptosis. hAG (K1-3) combined with TRAIL can inhibit tumor growth more efficiently.

RNA interference-mediated silencing of the Hsp70 gene inhibits human gastric cancer cell growth and induces apoptosis in vitro and in vivo.

AIMS AND BACKGROUND: The role of heat shock protein (HSP) 70 in gastric cancer has been extensively examined in many studies for the past decade. It has been demonstrated that over-expression of Hsp70 might play important role in malignant transformation and maintenance of malignant phenotypes. Therefore, silencing the Hsp70 gene could be applicable in molecular therapies of human gastric cancer. Herein, we designed a small interfering RNA targeting Hsp70 to knock down its expression and investigated its effect on cell proliferation and apoptosis in a gastric cancer cell line. METHODS: Two plasmids (phsp1-siRNA, phsp2-siRNA), along with a negative control (phsp3-siRNA), were created using a genic recombination technique. BGC823 cell lines were used to perform experiments. Western blotting and RT-PCR were used to detect Hsp70 expression in vitro and in vivo. Cell morphology was observed under light microscope. Cell cycle and apoptosis were analyzed by flow cytometry and acridine orange/ethidium bromide double stain, and cell proliferative activity was measured by alamarblue assay. In all experiments, a negative control served as a baseline measure. RESULTS: We successfully constructed phsps-siRNA plasmids and transfected them into BGC823 cells. RT-PCR and western blotting revealed that the expression of Hsp70 was down-regulated in transfection groups compared with the control group. Flow cytometric analysis indicated that less S-phase fraction accumulated in small interfering RNA transfected cells than in parental cells and the cells transfected with empty vector. CONCLUSIONS: Our results demonstrated that RNAi against Hsp70 could effectively knock down gene expression, inhibit growth of cancer cells, induce cell cycle arrest and increase cell apoptosis in vitro and in vivo. Hsp70 might serve as a therapeutic target for human gastric cancer.

Comparison of esomeprazole enteric-coated capsules vs esomeprazole magnesium in the treatment of active duodenal ulcer: a randomized, double-blind, controlled study.

AIM: To evaluate the efficacy and tolerability of two different preparations of esomeprazole in healing duodenal ulcers. METHODS: A total of 60 patients with active duodenal ulcers were enrolled and randomized to receive esomeprazole enteric-coated capsules (40 mg) or esomeprazole magnesium (40 mg), once daily, for 4 consecutive wk, with ulcer healing being monitored by endoscopy. Safety and tolerability were also assessed. RESULTS: Fifty seven patients completed the whole trial. The ulcer healing rates at the end of wk 2 were 86.7% and 85.2% in the esomeprazole enteric-coated capsules and esomeprazole magnesium groups, respectively (P = 0.8410), and reached 100% at the end of wk 4 in both groups. Symptom relief at the end of wk 2 was 90.8% in the esomeprazole enteric-coated capsules group and 86.7% in the esomeprazole magnesium group (P = 0.5406); at the end of wk 4 symptom relief was 95.2% and 93.2%, respectively (P = 0.5786). Adverse events occurred in 16.7% of the esomeprazole enteric-coated capsules group and 14.8% of the esomeprazole magnesium group (P = 1.0000). CONCLUSION: The efficacies of esomeprazole enteric-coated capsules and esomeprazole magnesium in healing duodenal ulcer lesions and relieving gastrointestinal symptoms are equivalent. The tolerability and safety of both drugs were comparable.

Diagnosis of Helicobacter pylori infection and diseases associated with Helicobacter pylori by Helicobacter pylori outer membrane proteins.

AIM: To examine the serological response of patients with upper gastrointestinal diseases and Helicobocter pylori (H pylori) infection to two H pylori outer membrane proteins (OMPs) (Mr18,000 and Mr 26,000) acquired by gene recombinant technique, and to determine the diagnostic significance of serological tests derived from these OMPs. METHODS: Recombinant vectors encoding the two H pylori OMPs were used to transform and express in BL21 (DE3) E.coli. After purification with Ni2+-NTA agarose resin, colloid gold kits were prepared with purified recombinant proteins to detect H pylori infection and H pylori-associated diseases by the immunity-marker technology. We selected 150 patients with H pylori infection and digestive symptoms without previous treatment, including chronic gastritis (n = 60), duodenal ulcer (n = 30), gastric ulcer (n = 30), and gastric cancer (n = 30). As controls, 33 H pylori-negative healthy volunteers were also recruited. Serum samples were collected from all subjects, and the antibodies to specific proteins of H pylori were tested with the colloid gold test kits. The sensitivity, specificity and accuracy of the colloid gold tests were evaluated, by using the combination of standard diagnostic methods (13C urea breath test and bacteria culture) and classic enzyme-linked immunosorbent assay (ELISA) as reference. RESULTS: After purification with Ni2+-NTA agarose resin, the purity of recombinant fusion proteins was about 95%. The recombinant fusion proteins were recognized by the specific monoclonal antibodies against the two H pylori OMPs, as demonstrated by the ELISA. Of the 150 serum samples from patients infected with H pylori 141 (94.0%) responded positively to the recombinant protein with Mr 26,000, while the seropositive rates were 95.0%, 96.7%, 96.7% and 90.0% for patients with H pylori-associated chronic gastritis, duodenal ulcer, gastric ulcer, and gastric cancer respectively. The sensitivity, specificity, and accuracy of the colloid gold kit with Mr 26,000 protein were 94.0%, 97.0%, and 94.5%, respectively. Compared with the classic ELISA, bacteria culture and 13C urea breath test results in detecting H pylori-infection, there was no significant difference (P>0.05). For the colloid gold kit with Mr 18,000, the seropositive rates were 52.0%, 40.0%, 40.0%, 53.3% and 86.7%, respectively, in H pylori-infected patients, and those with H pylori-associated chronic gastritis, duodenal ulcer, gastric ulcer, and gastric cancer. There was a significant difference (P<0.05) in seropositivity between patient with gastric cancer (86.7%) and those with other diseases (43.3%). CONCLUSION: The two colloid gold kits derived from the recombinant OMPs are useful tools either for detecting H pylori infection, or for, predicting H pylori-associated gastric malignancy.

Cloning and sequence analysis of gene oipA encoding an outer membrane protein of human Helicobacter pylori.

AIM: To construct a recombinant E. coli strain that would highly express the proinflammatory outer membrane protein of human Helicobacter pylori (H pylori). METHODS: The oipA DNA was amplified by PCR, inserted into pET-32a, and transformed into Top10 E. coli strain. This recombinant plasmid of Top10 was sent out for nucleotide sequence analysis. Finally this sequence AF479754 was compared with HP0638 and JHP0581. RESULTS: The sequence of the aim gene was obtained. It had 924 base pairs. The identity was 95.32% against HP0638, 95.02% against JHP0581, which was higher than the identity between HP0638 and JHP0581. CONCLUSION: Although the aim gene was obtained, but it was different from the published sequence of GenBank. It is not clear what makes this difference. Maybe it is because different strain was used or because there were some variations. So more researches are required to prove it.

[Construction, expression and antigenicity of bivalent vaccine candidate of human Helicobacter pylori].

AIM: To construct a recombinant vector containing fused gene of heat shock protein A(HspA) and outer membrane protein(OMP) with M(r) 18,000, from human Helicobacter pylori(Hp) and express the fusion protein in E.coli BL21. METHODS: The gene encoding HspA was amplified from Hp chromosome by PCR. After digestion with kpn I and BamH I, the HspA gene was inserted into the prokaryotic expression vector pET32a(+). After recombinant vectors pET32a(+)/HspA and pET32a(+)/Omp (18) were digested with Hind III and BamH I, the pET32a(+)/HspA and 18,000 OMP gene segments were recovered through agarose electrophoresis, and connected by T4 ligase. The recombinant vector pET32a(+)/HspA-Omp(18) was transformed into E.coli BL21(DE3). The antigenicity of recombinant fusion protein was analysed by Western blot. RESULTS: Enzyme digestion analysis and sequencing showed that the fused gene had 891 base pairs. As compared with gene reported in GenBank, there were 1.15% and 1.26% differences in cloned nucleotide sequence and amino acid sequence respectively. SDS-PAGE analysis showed that recombinant vector could be expressed in E.coli BL21. The relative molecule mass (M(r)) of expressed fusion protein was 51x10(3). And soluble expression product accounted for 18.96% of total bacterial protein.After purification via Ni-NTA agarose resin, the purity of recombinant fusion protein was about 95%. The Western blot analysis showed that recombinant fusion protein could be recognized by anti-Hp positive serum and anti-18,000 OMP mAb, suggesting that this protein had good antigenicity. CONCLUSION: The fused gene of HspA and OMP is cloned and expressed successfully, which lays the foundation for development of protein and DNA vaccines and a diagnostic kit of Hp infection.

[Construction, expression and antigenic study of bivalent vaccine candidate with 26,000 OMP and heat short protein A of human Helicobacter pylori].

OBJECTIVE: To construct a recombinant vector containing gene encoding heat shock protein A (HspA) and outer membrane protein (OMP) with relative molecule mass (Mr) of 13,000 and 26,000 respectively from human Helicobacter pylori (Hp) and be expressed in E. coli BL21, as well as analyse its antigenic for the exploiting vaccine of Hp. METHODS: The target gene encoding heat shock protein A was amplified from Hp chromosome by PCR. And then digested by restricted endonuclease enzyme of kpnI, BamH I simultaneously, and inserted into the prokaryotic expression vector pET32a(+) digested by corresponding restricted endonuclease enzyme. The recombinant vector was used to select and transform for sequence analysis. After pET32a(+)/HspA and pET32a(+)/Omp(26) digested by restricted endonuclease enzyme of Hind III, BamH I simultaneously, the pET32a(+)/HspA and 26,000 OMP were taken out of agarose electrophoresis, and connected by T4 ligase. The recombinant vector pET32a(+)/HspA-Omp(26) was used to select and transform, meanwhile expressed in E. coli BL21(DE3). The antigenic of recombinant fusion protein was analysed by western blotting. RESULTS: Enzyme digestion analysis and sequencing showed that the target genes was found to be 951 base pairs, and had been inserted into recombinant vector, but as compared with gene reported by GenBank, 1.15% of the gene mutation and 1.26% of amino acid residues change in Hp happened respectively. SDS-PAGE analysis showed that recombinant vector could be expressed in E. coli BL21, its relative molecule mass of expressed product was 59 x 10(3), while Mr of protein expressed by pET32a(+) of them was about 20 x 10(3), and soluble expression product accounted for 19.96% of total bacterial protein. After purification with Ni-NTA agarose resin, the purity of recombinant fusion protein was about 95%. The western blot result showed that recombinant fusion protein could be recognized by anti-Hp positive serum and monoclonal antibody of 26,000 OMP, suggesting that this protein had good antigenic. CONCLUSION: The genes coding HspA and OMP with Mr 13,000 and 26,000 respectively are cloned and expressed successfully. The results obtained lay the foundation for research on development of Hp protein and DNA vaccine and a quickly diagnostic kit applying to detection of Hp infection.

Construction and characterization of bivalent vaccine candidate expressing HspA and M(r)18,000 OMP from Helicobacter pylori.

AIM: To construct a recombinant vector which can express outer membrane protein (OMP) with M(r)18,000 and heat shock protein A (HspA) from Helicobacter pylori (H. pylori) in E. coli BL21, and to exploit the possibility for obtaining the vaccine conferring protection from H. pylori infection. METHODS: The target gene of HspA was amplified from H. pylori chromosome by PCR, and then inserted into the prokaryotic expression vector pET32a (+) by restrictive endonuclease enzyme kpn I, BamH I simultaneously. The recombinant vector was used to sequence, and then together with pET32a (+)/Omp(18), digested by restrictive endonuclease enzyme Hind III and BamH I simultaneously. pET32a(+)/HspA and Omp(18) were recovered from 1 % agarose gel by gel kit, and ligated with T(4) ligase by BamH I digested viscidity end. The recombinant plasmid of pET32a(+)/HspA/Omp(18) was transformed and expressed in E. coli BL21 (DE3) under induction of IPTG. After purification, its antigenicity of the fusion protein was detected by Western blot. RESULTS: Enzyme digestion analysis and sequencing showed that the target genes were inserted into the recombinant vector, composed of 891 base pairs, encoded objective polypeptides of 297 amino acid residues. Compared with GenBank reported by Tomb et al, there were 1.3 % and 1.4 % differences in obtained H. pylori nucleotide sequence and amino acid residues, respectively. SDS-PAGE analysis showed that relative molecule mass (M(r)) of the expressed product was M(r) 51,000, M(r) of protein expressed by pET32a (+) was about M(r) 20,000, and soluble expression product accounted for 18.96 % of total bacterial protein. After purification with Ni(+2)-NTA agarose resins, the purification of recombinant fusion protein was about 95 %. Western blot showed that recombinant fusion protein could be recognized by the patients' serum infected with H. pylori and anti-Omp(18) monoclone, suggesting that this protein had good antigenicity. CONCLUSION: The gene coding for H. pylori M(r)18,000 OMP and HspA was cloned and expressed successfully. The results obtained lay the foundation for development of H. pylori protein vaccine and a quick diagnostic kit.

A study of recombinant protective H.pylori antigens.

AIM: To construct a recombinant vector which can express M (r)26000 outer membrane protein (OMP) from Helicobacter pylori (Hp), and to obtain the vaccine protecting against Hp infection and a diagnostic reagent kit quickly detecting Hp infection. METHODS: The gene encoding the structural M(r)26000 outer membrane protein of Hp was amplified from Hp chromosomal DNA by PCR, and inserted in the prokaryotic expression vector pET32a (+), which was transformed into the Top10 E. coli strain. Recombinant vector was selected, identified and transformed into BL-21(DE3) E. coli strain. The recombinant fusion proteins were expressed. The antigenicity of recombinant protein was studied by ELISA or immunoblotting and immunized Balb/c mice. RESULTS: The gene of M(r)26000 OMP was amplified to be 594 base pairs, 1.1% of the cloned genes was mutated and 1.51% of amino acid residues was changed, but there was homogeneity between them. The recombinant fusion protein encoded objective polypeptides of 198 amino acid residues, corresponding to calculated molecular masses of M (r)26000. The level of soluble expression products was about 38.96% of the total cell protein. After purification by Ni-NTA agarose resin columniation, the purity of objective protein became about 90%. The ELISA results showed that recombinant fusion protein could be recognized by patient serum infected with Hp and rabbit serum immunized with the recombinant protein. Furthermore,Balb/c mice immunized with the recombinant protein were protected against H.pylori infection. CONCLUSION: M (r)26000 OMP may be a candidate vaccine preventing Hp infection.