Esophageal Acid Clearance During Random Swallowing Is Faster in Patients with Barrett's Esophagus Than in Healthy Controls

N-Benzyl piperidine Fragment in Drug Discovery

The N-benzyl piperidine (N-BP) structural motif is commonly employed in drug discovery due to its structural flexibility and three-dimensional nature. Medicinal chemists frequently utilize the N-BP motif as a versatile tool to fine-tune both efficacy and physicochemical properties in drug development. It provides crucial cation-π interactions with the target protein and also serves as a platform for optimizing stereochemical aspects of potency and toxicity. This motif is found in numerous approved drugs and clinical/preclinical candidates. This review focuses on the applications of the N-BP motif in drug discovery campaigns, emphasizing its role in imparting medicinally relevant properties. The review also provides an overview of approved drugs, the clinical and preclinical pipeline, and discusses its utility for specific therapeutic targets and indications, along with potential challenges.

Patients with Barrett's esophagus are hypersensitive to acid but hyposensitive to other stimuli compared with healthy controls

BACKGROUND

Esophageal hyposensitivity has been observed in Barrett's esophagus and may contribute to its pathophysiology. However, studies are few, in particular those assessing different sensory modalities. We aimed to compare esophageal sensitivity to multimodal stimulation in patients with Barrett's esophagus and in healthy controls.

METHODS

Twenty-three patients with Barrett's esophagus and 12 healthy controls were examined. A multimodal probe was placed in the lower esophagus. Mechanical, thermal, and electrical stimulation was applied followed by an acid perfusion test with 0.1 N hydrochloric acid.

KEY RESULTS

Compared with controls, patients were hyposensitive to mechanical distension, heat, and electrical stimulation (all P<.05), but hypersensitive to acid (mean tolerated acid volume 57% lower, P=.001). A linear correlation between acid hypersensitivity and lower baseline impedance was found (P<.001). Patients had longer esophageal acid exposure time than controls (median acid exposure time 18 vs 5%, P=.03). Asymptomatic patients (no reflux symptoms at baseline) were hyposensitive to mechanical distension, electrical stimulation, and acid perfusion (all P<.05) compared with symptomatic patients.

CONCLUSIONS & INFERENCES

Patients with Barrett's esophagus exhibited acid hypersensitivity but hyposensitivity to other stimuli. Lower mucosal baseline impedance, a likely surrogate marker for impaired mucosal integrity, may explain the selective hypersensitivity to acid. On the other hand, the concurrent hyposensitivity may theoretically be explained by changes in central pain modulation. Patients with Barrett's esophagus seem to compose symptomatic and asymptomatic subgroups, showing different esophageal sensory profiles.