Characterization and application of a new monoclonal antibody with high specificity for Helicobacter hepaticus.

BACKGROUND AND AIMS: Infection with Helicobacter hepaticus is suggested to play a role in the pathogenesis of chronic liver disease in humans. However, reactive antigens among Helicobacter species make the development of an H. hepaticus ELISA test with high specificity difficult. A new monoclonal antibody from a hybridoma clone (HRII-51) showed high specificity to H. hepaticus without cross-reaction to other gastrointestinal bacteria. METHODS: The molecular weight of HRII-51 immunoreactive antigen was examined by Western blot of H. hepaticus probed with the monoclonal antibody HRII-51. A HRII-51-immunoreactive antigen capture ELISA was prepared in which the specific antigen was anchored by HRII-51-immobilized ELISA plate. Accuracy of HRII-51 antigen capture ELISA was examined using sera obtained from mice inoculated with Helicobacter species. Specificity of HRII-51 antigen capture ELISA was compared to that of H. hepaticus antigen-based ELISA using human sera with absorption by H. pylori cell lysate. RESULTS: HRII-51 immunoreactive antigen had a molecular weight of 15 kDa. Sensitivity and specificity of HRII-51 antigen capture ELISA were 87.0% and 97.6% in mice inoculated with Helicobacter species. In human sera, modification of the results by absorption with H. pylori lysate was smaller in HRII-51 antigen capture ELISA comparing with H. hepaticus-antigen-based ELISA. CONCLUSION: Use of the HRII-51 antigen capture ELISA would be a useful approach for the serodiagnosis of H. hepaticus infection in both experimental animals and humans.

Free radicals in phacoemulsification and aspiration procedures.

OBJECTIVES: To detect free radicals in phacoemulsification and aspiration procedures using electron-spin resonance and to observe the effect of ophthalmic viscosurgical devices (viscoelastic agents) on free radical intensity. METHODS: (1) A test tube containing BSS Plus (Alcon Laboratories, Inc, Fort Worth, Tex) with 1% of the spin-trapping agent, 5,5'-dimethyl-1-pyrroline N-oxide, without irrigation and aspiration, was exposed to ultrasound (100% for 20 seconds). A preparation of hyaluronate sodium (Healon [a cohesive agent that contains 1% hyaluronate sodium] (Pharmacia, Uppsala, Sweden) or Viscoat [a dispersive agent that contains 3% hyaluronate sodium and 4% chondroitin sulfate] (Alcon Laboratories, Inc)) was added to the solution to observe inhibitory effects. (2) To simulate a clinical procedure, an eye model with irrigation and aspiration of a combination of 1% 5,5'-dimethyl-1-pyrroline N-oxide and BSS Plus, 25 mL/min, as the irrigating solution was exposed to ultrasound (for 10, 20, or 30 seconds). Healon or Viscoat was injected into the anterior chamber. Free radicals were measured by an electron-spin resonance spectrometer. RESULTS: (1) A characteristic signal corresponding to hydroxyl radicals was detected. Similar inhibition by Healon and Viscoat was observed. (2) Two ophthalmic viscosurgical devices similarly suppressed the signal at 10 seconds. The inhibition by Healon ceased at 20 seconds, whereas Viscoat suppressed the signal throughout the time course. CONCLUSIONS: Phacoemulsification produces hydroxyl radicals in the anterior chamber even with irrigation and aspiration. The effect of ophthalmic viscosurgical devices on free radicals depends on the retention of the materials within the anterior chamber. CLINICAL RELEVANCE: There are complications associated with phacoemulsification.