pylori infection. Therefore, IRF8 may play an important role in immune response to H. pylori infection. Key Word(s): 1. Helicobacter pylori; 2. IRF8; Presenting Author: NUTTAPORN- NORRASETWANICH Additional Authors: TANISA- PATCHARATRAKUL, SUTEP- GONLACHANVIT

Corresponding FG 4592 Author: SUTEP- GONLACHANVIT Objective: To study if isosorbide dinitrate (ISDN) can restore esophageal peristalsis contractions in patients with diffuse or segmental simultaneous esophageal contraction. Methods: 10 patients (8F, age 49+10 years) with diffuse or segmental simultaneous esophageal contractions ≥ 20% of wet swallows underwent high resolution esophageal manometry (HRM) with ISDN spray or normal saline (NSS) spray, in 2 occasions at least 3 days apart, in a randomized cross-over fashion. For each HRM study, after a 5-minute rest period, the esophageal contractions in response to 10 wet swallows were studied at baseline, 7 minutes after the 1st 1-puffs and the 2nd 1-puffs R428 of ISDN or NSS spray. Esophageal contractions were classified as simultaneous contraction if contractile front velocity (CFV) was > 8 cm/sec. Esophageal contraction

parameters were analyzed using ManoView analysis software version 2.0. 1. Results: All patients completed the studies. Seven and 5 patients had dysphagia and chest discomfort as their esophageal symptoms, respectively. The prevalence of simultaneous contraction was similar at baseline (ISDNvs. NSS = 49 ± 13%vs. 47 ± 17%) and significantly decreased by ISDN only after the first dose (25 ± 15%vs. 44 ± 2.4%) (p < 0.005) but not the 2nd dose (25 ± 23%vs. 32 ± 24%, p > 0.05) compared to NSS. The prevalence of esophageal peristalsis contractions was similar at

baseline (43 ± 19%vs. 43 ± 17%) and significantly increased by ISDN only after the 1st dose (65 ± 21%vs. 50 ± 25%) (p < 0.05) but not RVX-208 the 2nd dose (69 ± 23%vs. 63 ± 23%) (p > 0.05). The DCI was similar at baseline (1639 ± 276 vs. 1986 ± 353 mmHg s−1cm−1) but decreased after the 1st dose (1421 ± 265 vs. 2363 ± 500) and significantly decreased after the 2nd dose of ISDN (1399 ± 234 vs. 2409 ± 408) (p < 0.05) compared to NSS. There was no significant difference of the IRP, residual UES relaxation pressure and UES resting pressure comparing between ISDN and NSS (p > 0.05). Conclusion: In patients with distal esophageal contraction, proportion of esophageal peristalsis contraction was increased overtime after HRM catheter insertion. ISDN significantly improved esophageal peristalsis contractions earlier than NSS. This study suggests the role of exogenous NO on the restoration of esophageal peristalsis contractions in patients with distal esophageal spasm. Key Word(s): 1. Nitric Oxide; 2. Esophageal; 3. Peristalsis; 4.