Impact of clarithromycin resistance on eradication of Helicobacter pylori in infected adults.

The outcome of Helicobacter pylori infection was analyzed in 114 dyspeptic patients treated with triple-drug therapy including clarithromycin. Clarithromycin resistance (in 20.2% of our isolates) was mainly caused by an A2142G mutation in the 23S rRNA gene of H. pylori. H. pylori eradication was obtained in all patients with clarithromycin-susceptible isolates but not in any patients with clarithromycin-resistant isolates (P = 0.0001). Therefore, it would be useful to conduct H. pylori antimicrobial susceptibility testing of the first gastric biopsy culture before choosing the first three drugs for therapy of infected patients.

Production of anti-Helicobacter pylori urease-specific immunoglobulin in egg yolk using an antigenic epitope of H. pylori urease.

The potential therapeutic effects of Helicobacter pylori-specific immunoglobulin (IgY-Hp) derived from egg yolk and identification of the immunodominant H. pylori proteins have previously been reported. In this study, the urease epitope that is recognized by IgY-Hp was identified and used as an immunogen to produce urease-specific IgY (IgY-HpU). Epitope regions were mapped and peptides of selected epitope regions were synthesized. The IgY-Hp titre against synthetic peptides was evaluated using ELISA analysis. Hens were immunized with synthetic peptides conjugated with BSA. Urease activity was quantified by measuring the optical density of an indicator dye. Of the five synthetic peptides assayed, a peptide representing 15 amino acid residues of UreB (UB-3; aa 396-410, DNDNFRIKRYLSKYT) was specifically recognized by the IgY-Hp. Immunization of hens with BSA-conjugated UB-3 resulted in the generation of IgY-HpU. IgY-HpU markedly reduced H. pylori urease activity by 80 % as compared to control IgY (IgY-BSA). The availability of the synthetic UreB-derived peptide enabled the production of highly specific anti-urease IgY, which had a significant inhibitory effect on H. pylori urease activity. Therefore, specific IgY-HpU produced using the synthetic peptide may be an effective tool against infection by H. pylori.

Identification of immunodominant Helicobacter pylori proteins with reactivity to H. pylori-specific egg-yolk immunoglobulin.

The importance of hens eggs as a source of specific antibodies (IgY) is well recognized. The protective effect of IgY obtained from hens immunized with Helicobacter pylori whole-cell lysate has been reported for the control of H. pylori infection. However, IgY produced by whole-cell lysates presents the possibility of cross-reactivity with other bacteria, including the normal human flora, and this could decrease the efficiency of IgY. In the present study, the immunodominant proteins of H. pylori with reactivity to H. pylori-specific IgY (IgY-Hp) were identified. IgY obtained from hens immunized with various fractions of H. pylori proteins was isolated and purified, titres of IgY-Hp against H. pylori were determined and cross-reactivity between IgY-Hp and normal human bacteria was examined by Western blot analysis. Finally, immunodominant H. pylori proteins were identified by LC/MS analysis. IgY obtained 2 months after immunization with H. pylori whole-cell lysate showed the highest antibody titre. Five immunodominant proteins were identified that were strongly reactive to IgY-Hp: urease beta-subunit (62 kDa), heat-shock protein 60 (60 kDa), urease alpha-subunit (26 kDa), probable peroxiredoxin (22 kDa) and probable thiol peroxidase (18 kDa). Immunization of hens with the immunodominant proteins identified would produce a more specific IgY against H. pylori.

Use of egg yolk-derived immunoglobulin as an alternative to antibiotic treatment for control of Helicobacter pylori infection.

The present study evaluated the potential use of immunoglobulin prepared from the egg yolk of hens immunized with Helicobacter pylori (immunoglobulin Y [IgY]-Hp) in the treatment of H. pylori infections. The purity of our purified IgY-Hp was 91.3%, with a yield of 9.4 mg of IgY per ml of egg yolk. The titer for IgY-Hp was 16 times higher than that for IgY in egg yolk from nonimmunized hens, and IgY-Hp significantly inhibited the growth and urease activity of H. pylori in vitro. Bacterial adhesion on AGS cells was definitely reduced by preincubation of both H. pylori (10(8) CFU/ml) and 10 mg of IgY-Hp/ml. In Mongolian gerbil models, IgY-Hp decreased H. pylori-induced gastric mucosal injury as determined by the degree of lymphocyte and neutrophil infiltration. Therefore, in this experimental model, H. pylori-associated gastritis could be successfully treated by orally administered IgY-Hp. The immunological activity of IgY-Hp stayed active at 60 degrees C for 10 min, suggesting that pasteurization can be applied to sterilize the product. Fortification of food products with this immunoglobulin would significantly decrease the H. pylori infection. In conclusion, the IgY-Hp obtained from hens immunized by H. pylori could provide a novel alternative approach to treatment of H. pylori infection.

Normal structure, variations, and anomalies of the pancreaticobiliary ducts of Koreans: a nationwide cooperative prospective study.

BACKGROUND: This study evaluated the normal pancreaticobiliary ducts of Koreans and assessed the frequency and pattern of variations and anomalies of these structures. METHODS: A prospective, nationwide multicenter study was performed in which 10 university hospitals in Korea participated from March 1997 to June 1999. A total 10,243 patients undergoing ERCP were enrolled. RESULTS: The mean (SD) maximal and midportion diameters in millimeters of the common hepatic duct were, respectively, 6.1 (1.8) and 5.3 (1.6). The mean maximal and midportion diameters (mm) of the common bile duct were, respectively, 6.4 (1.8) and 5.5 (1.7). The mean maximal and midportion diameters (mm) of the main pancreatic duct in the head, body and tail were, respectively, 3.2 (1.1), 2.7 (1.0), and 2.5 (2.3); and, respectively, 2.2 (0.9), 1.6 (0.7) and 1.4 (0.6). Pancreaticobiliary duct diameters for patients above the age of 40 were greater than those of patients less than 40 years of age (p < 0.05). The frequency of choledochal cyst and anomalous union of the pancreaticobiliary ducts were, respectively, 0.32% and 4.1%. Pancreas divisum and annular pancreas were found, respectively, in 0.49% and 0.05%. CONCLUSIONS: A knowledge of normal pancreaticobiliary ductal structures as well as the frequency and pattern of variations including anomalies is essential for the diagnosis and treatment of pancreaticobiliary disorders.

Features of malignant biliary obstruction affecting the patency of metallic stents: a multicenter study.

BACKGROUND: Although placement of a metallic stent is an established therapeutic option for the palliation of patients with malignant biliary obstruction, it remains unclear which stricture-related or stent-related factors influence stent patency. METHODS: Metallic stents were inserted endoscopically in 68 patients (38 men, 30 women; mean age 70.2 plus minus 8.5 years) with malignant biliary obstruction. Patency rates were prospectively analyzed according to malignant stricture characteristics, including length, morphologic type, and degree of narrowing. Furthermore, patient age, initial serum bilirubin level, length of stent, time to adequate expansion, and the location of the distal end of the stent were evaluated as possible factors affecting the stent patency. Stent patency was assessed by using the survival analysis of the Kaplan-Meier estimation and Cox regression analysis. RESULTS: Median overall stent patency was 231 days (range 27-379 days) and the overall rate of stent occlusion 41.2% (28/68). The causes of occlusion were tumor ingrowth in 23 patients (33.8%), distal overgrowth in 3 (4.4%), proximal overgrowth in 1 (1.5%), and encrustation with sludge in 1 patient (1.5%). No significant differences in patency rates according to patient age, initial serum bilirubin level, primary tumor type, length and morphologic type of stricture, and length and location of the distal end of the stent were found. Cox regression analysis demonstrated that the degree of narrowing assessed by cannula or guidewire passage and the time to adequate expansion of the stent were independent factors associated with stent patency. CONCLUSION: Early expansion of the stent and easy passage of larger-caliber instruments through the stricture were favorable factors for long-term patency of the Wallstent.