Physiological augmentation of esophageal distension pressure and peristalsis during conditions of increased esophageal emptying resistance.

BACKGROUND: Abdominal compression has been implemented as a provocative maneuver in high-resolution impedance manometry (HRIM) to "challenge" normal esophageal physiology with the aim of revealing abnormal motor patterns which may explain symptoms. In this study, we measured the effects of abdominal compression on esophageal functioning utilizing novel pressure-impedance parameters and attempted to identify differences between healthy controls and globus patients. METHODS: Twenty-two healthy volunteers (aged 23-32 years, 41% female) and 22 globus patients (aged 23-72 years, 68% female) were evaluated with HRIM using a 3.2-mm water perfused manometric and impedance catheter. All participants received 10 × 5 mL liquid swallows; healthy controls also received 10 × 5 mL liquid swallows with abdominal compression created using an inflatable cuff. All swallows were analyzed to assess esophageal pressure topography (EPT) and pressure-flow metrics, indicative of distension pressure, flow timing and bolus clearance were derived. KEY RESULTS: The effect of abdominal compression was shown as a greater contractile vigor of the distal esophagus by EPT and higher distension pressure based on pressure-flow metrics. Age and body mass index also increased contractile vigor and distension pressure. Globus patients were similar to controls. CONCLUSIONS AND INTERFERENCES: Intrabolus pressure and contractile vigor are indicative of the physiological modulation of bolus transport mechanisms. Provocative testing by abdominal compression induces changes in these esophageal bolus dynamics.

Selenium-catalyzed oxidations with aqueous hydrogen peroxide. 2. Baeyer-Villiger reactions in homogeneous solution.

Several diselenides were tested for catalytic activity in Baeyer-Villiger reactions with 60% aqueous hydrogen peroxide. Bis[3,5-bis(trifluoromethyl)phenyl] diselenide forms the corresponding 3,5-bis(trifluoromethyl)benzene seleninic acid in situ, which is a highly reactive and selective catalyst for the oxidation of carbonyl compounds in 1,1,1,3,3,3-hexafluoro-2-propanol, 2,2,2-trifluoroethanol, or dichloromethane.