BACKGROUND/AIMS: The sensitivity of the upper and lower esophageal mucosa to acid is considered to differ. We investigated the relationship between pH changes in different sites of the esophagus and generation of gastroesophageal reflux symptoms during an acid infusion test. METHODS: An acid infusion catheter was placed at 5 or 15 cm above the lower esophageal sphincter (LES) in 18 healthy volunteers, while a 2-channel pH sensor catheter was also placed in each with the sensors set at 5 and 15 cm above the LES. Solutions containing water and hydrochloric acid at different concentrations were infused through the infusion catheter. RESULTS: Acid infusion in the upper esophagus caused a pH drop in both upper and lower esophageal sites, whereas that in the lower esophagus resulted in a significant pH drop only in the lower without a corresponding pH decline in the upper esophagus. Stronger heartburn, chest pain, and chest oppression symptoms were noted when acid was infused in the upper as compared to the lower esophagus, while increased intra-esophageal acidity strengthened each symptom. Regurgitations caused by upper and lower esophageal acid infusions were similar, and not worsened by a larger drop in intra-esophageal pH. Chest pain was caused only by lowered intra-esophageal pH, while heartburn, chest oppression, and regurgitation were induced by a less acidic solution. CONCLUSIONS: Higher intra-esophageal acidity caused stronger heartburn, chest pain, and chest oppression symptoms. However, regurgitation was not significantly influenced by intra-esophageal acidity. The upper esophagus showed higher acid sensitivity than the lower esophagus.
Adult ; Catheters ; Chest Pain ; Esophageal pH Monitoring* ; Esophageal Sphincter, Lower ; Esophagus ; Gastroesophageal Reflux* ; Heartburn ; Humans ; Hydrochloric Acid ; Hydrogen-Ion Concentration ; Mucous Membrane ; Thorax ; Water

Objectives: First steps to promote the proper use of medicines in remote islands and rural areas are as follows: (1) recognition of the profession of “pharmacist” from secondary-remote-island residents who do not have a pharmacy or drugstore or the opportunity for pharmacist contact and (2) an understanding by remote-island residents of the advantages of having a “family pharmacist.”
Methods: Repeated “medicine information and consultation sessions” for secondary-remote-island residents of Japan’s Nagasaki Prefecture were held.  Residents were then surveyed for changes in awareness of or demand for pharmacists and the nature of such changes.
Results: Before the information sessions, 29.7% of residents did not recognize the profession of pharmacy, but the extent of their recognition increased after information sessions were concluded.  They were asked “Who explains medicines in a way that is easy to understand ?”; more than half responded “doctors” before the information session, but after information sessions were concluded, those who said “pharmacists” increased.
Conclusion: Conducting “medicine information and consultation sessions” for residents of secondary-remote islands and rural areas enabled them to understand the profession of pharmacy.  The initiatives in the present study are first steps toward promoting proper use of medicines by residents of remote islands and rural areas who use “family pharmacies/pharmacists.”