Effect of EP1 Receptor Antagonist on Transient Lower Esophageal Sphincter Relaxations in Humans.

BACKGROUND/AIMS: Transient lower esophageal sphincter relaxations (TLESRs) are the major cause of gastroesophageal reflux. Recently, an EP1 receptor antagonist, ONO-8539, showed the reduction of TLESRs in monkeys. However, its effect on TLESRs in humans remains unclear. This study investigated the effect of ONO-8539 on postprandial TLESRs in healthy male subjects. METHODS: Twenty-seven subjects participated in this placebo-controlled, cross-over study. The subjects received either placebo or ONO-8539 (450 mg) after a standardized breakfast. A 30-min basal recording was performed 4 h after drug administration. Subsequently, TLESR recordings were performed after a high-fat test meal for 3 h. The examination was repeated at least 7 days from the first evaluation for washout. RESULTS: Thirteen patients were ultimately analyzed. The basal lower esophageal sphincter pressure was not different between the 2 groups (16.3 and 18.0 mm Hg for placebo and ONO-8539, respectively; p = 0.88). ONO-8539 significantly reduced the number of TLESRs from 15.0 to 12.0 for 3 h (p < 0.05). The proportion of terminating events of TLESRs was significantly different between the 2 groups (p < 0.05). No events and swallowing terminated more TLESRs with ONO-8539 than with placebo. CONCLUSIONS: ONO-8539 suppressed TLESRs mildly. EP1 receptor may be involved with the mechanism of human TLESRs.

Optimal Biopsy Protocol to Evaluate Histological Effectiveness of Proton Pump Inhibitor Therapy in Patients with Eosinophilic Esophagitis.

OBJECTIVE: Recent guidelines propose that both proton pump inhibitor (PPI) responders and nonresponders are included in eosinophilic esophagitis (EoE). Although multiple biopsies should be required to diagnose EoE because of patchy distribution of esophageal eosinophils, it is unclear whether multiple biopsies are required to evaluate histological effectiveness of PPI therapy. This study aimed to determine the optimal biopsy protocol after PPI therapy in patients with EoE. METHODS: Of 110 EoE patients, 22 PPI nonresponders were enrolled. Intraepithelial eosinophils were counted in areas of high density in multiple biopsy specimens after PPI therapy. The prevalence of esophageal eosinophilia and peak eosinophil counts after PPI therapy was analyzed according to the biopsy sites and endoscopic findings. Positive predictive value (PPV) was calculated according to the number of biopsies. RESULTS: Of 124 biopsies, 59 (47.6%) specimens showed esophageal eosinophilia (≥15 per high-power field). Eosinophil counts were significantly higher in specimens from the lower esophagus than in those from the upper esophagus but not in those from the middle esophagus. Prevalence of esophageal eosinophilia was 76.2, 40.9, and 24.3% in the lower, middle, and upper esophagus respectively. PPI nonresponders were diagnosed in all cases with 4 biopsy specimens obtained from the lower and middle esophagus, showing that PPV for non-effectiveness of PPI therapy was 0.910 (95% CI 0.773-1.000). The prevalence of esophageal eosinophilia and peak eosinophil counts was higher in cases with white plaques and linear furrows. CONCLUSION: Multiple biopsies should be required to evaluate histological effectiveness of PPI therapy in patients with EoE. Four biopsies from the lower and middle esophagus may be sufficient.

Changes in Clock Genes Expression in Esophagus in Rat Reflux Esophagitis.

BACKGROUND: Gastroesophageal reflux disease (GERD) is strongly associated with sleep disturbances. Clock genes harmonize circadian rhythms by their periodic expression and regulate several physiological functions. However, the association between clock genes and GERD is still unknown. AIMS: We investigated whether reflux esophagitis affects circadian variability of clock genes in the esophagus and other organs using a rat reflux esophagitis model. METHODS: Reflux esophagitis was induced in 7-week-old male Wistar rats. Sham-operated rats were used as controls. Rats were killed at 09:00 (light period) and 21:00 (dark period) 3 days (acute phase) and 21 days (chronic phase) after induction of esophagitis. The expression levels of clock gene mRNAs such as Per1, Per2, Per3, Cry1, Cry2, Arntl, and Clock in the esophagus were investigated by qPCR. Arntl expression was examined in stomach, small intestine, colon, and liver tissues. Serum melatonin and IL-6 levels were measured by ELISA. RESULTS: Histological examination of reflux esophagitis mainly revealed epithelial defects with marked inflammatory cell infiltration in the acute phase and mucosal thickening with basal cell hyperplasia in the chronic phase. Circadian variability of clock genes, except Cry1, was present in the normal esophagus and was completely disrupted in reflux esophagitis during the acute phase. The circadian variability of Per2, Per3, and Arntl returned to normal, but disruption of Per1, Cry2, and Clock was present in the chronic phase. Disruption of circadian variability of Arntl was observed in the esophagus, as well as in the stomach, small intestine, and liver tissues in reflux esophagitis during the acute phase. There were no significant differences in serum melatonin and IL-6 levels between control and reflux esophagitis animals in both acute and chronic phases. CONCLUSIONS: Disruption to circadian variability of clock genes may play a role in the pathogenesis of GERD.

Identification of Candidate Genes for Generalized Tonic-Clonic Seizures in Noda Epileptic Rat.

The Noda epileptic rat (NER) exhibits generalized tonic-clonic seizures (GTCS). A genetic linkage analysis identified two GTCS-associated loci, Ner1 on Chr 1 and Ner3 on Chr 5. The wild-type Ner1 and Ner3 alleles suppressed GTCS when combined in double-locus congenic lines, but not when present in single-locus congenic lines. Global expression analysis revealed that cholecystokinin B receptor (Cckbr) and suppressor of tumorigenicity 5 (St5), which map within Ner1, and PHD finger protein 24 (Phf24), which maps within Ner3, were significantly downregulated in NER. De novo BAC sequencing detected an insertion of an endogenous retrovirus sequence in intron 2 of the Phf24 gene in the NER genome, and PHF24 protein was almost absent in the NER brain. Phf24 encodes a Gαi-interacting protein involved in GABAB receptor signaling pathway. Based on these findings, we conclude that Cckbr, St5, and Phf24 are strong candidate genes for GTCS in NER.

Expression of Serum Exosomal and Esophageal MicroRNA in Rat Reflux Esophagitis.

Gastroesophageal reflux disease (GERD) is a common upper gastrointestinal disease. However, the role of exosomal microRNAs (miRNAs) and esophageal miRNAs in GERD has not been studied. A rat model of acid reflux esophagitis was used to establish a novel diagnosis marker for GERD and examine dynamics of miRNA expression in GERD. Rats were sacrificed 3 (acute phase), 7 (sub-acute phase) and 21 days (chronic phase) after induction of esophagitis. Exosomes were extracted from serum, and the expression patterns of serum miRNAs were analyzed. Four upregulated miRNAs (miR-29a-3p, 128-3p, 223-3p and 3473) were identified by microarray analysis. The expression levels of exosomal miR-29a-3p were significantly higher in the chronic phase of reflux esophagitis compared with controls, and increased expression of miR-29a-3p was specific to chronic reflux esophagitis. Esophageal miR-223-3p expression was higher compared with controls, and gradually decreased from acute to chronic phase in esophagitis. In conclusion, exosomal miR-29a-3p and esophageal miR-223-3p might play roles in GERD.

PHF24 is expressed in the inhibitory interneurons in rats.

Noda epileptic rat (NER) is a mutant model for epilepsy that exhibits spontaneous generalized tonic-clonic seizure. Epileptogenesis of NER remains to be elucidated; but it is detected an insertion of an endogenous retrovirus sequence in intron 2 of the PHD finger protein 24 (Phf24) gene, encoding Gαi-interacting protein (GINIP). Phf24 is a strong candidate gene for epileptogenesis in NER. PHF24 modulates GABAB signaling through interacting with Gαi protein. To clarify the epileptogenesis of NER, we investigated a distribution of PHF24-expressing cells in the central nerve system (CNS). While broad expression of PHF24 was observed in the CNS, characteristic expression was noted in the periglomerular layer of the olfactory bulb and the lamina II of the spinal cord in the control rats. These cells showed co-expression with calbindin or calretinin, inhibitory interneuron markers. In the olfactory bulb, 15.6% and 41.2% of PHF24-positive neurons co-expressed calbindin and calretinin, respectively. Immunoelectron microscopy revealed that PHF24 was located in the presynaptic terminals, synaptic membranes and cytoplasmic matrix of neuronal soma. Our data suggested PHF24 is expressed in the inhibitory interneurons and may play important roles in modulation of the GABAB signaling.

Association between endoscopic findings of eosinophilic esophagitis and responsiveness to proton pump inhibitors.

Background and study aims Endoscopic findings of esophageal eosinophilia sometimes localize to small areas of the esophagus. A previous study suggested that pathogenesis of localized-type eosinophilic esophagitis (LEoE) was associated with acid reflux. However, LEoE treatment outcomes have not been studied. We aimed to analyze the clinical and histologic significance of LEoE in comparison with diffuse-type eosinophilic esophagitis (DEoE). Patients and methods This study included 106 patients with esophageal eosinophilia. Esophageal eosinophilia was defined as a condition where the maximum number of intraepithelial eosinophils was ≥ 15 per high-power field. LEoE was defined as an endoscopic lesion confined to one-third of the esophagus: upper, middle, or lower. Esophageal eosinophilia encompassing more than two-thirds of the esophagus was defined as DEoE. We retrospectively compared LEoE and DEoE in terms of clinical characteristics, histologic findings, and proportion of proton pump inhibitor (PPI) responders. Results Of 106 patients, 12 were classified as having LEoE and 94 were classified as having DEoE. The proportion of asymptomatic patients was significantly higher in the LEoE group than the DEoE group (42 % vs 7 %, P  < 0.01). In the LEoE group, 10 patients (84 %) had endoscopic lesions in the lower esophagus. The maximum number of eosinophils did not differ between the groups (54 [24 - 71] for LEoE, 40 [20 - 75] for DEoE, P  = 0.65). The prevalence of PPI responders was significantly higher in the LEoE group than the DEoE group (100 % vs 63 %, P  = 0.01). Conclusion LEoE can be a sign of good responsiveness to PPI therapy.

Distal esophageal spasm with multiple esophageal diverticula successfully treated by peroral endoscopic myotomy.

Distal esophageal spasm (DES) is a primary esophageal motility disorder. We encountered a rare case of DES accompanied by multiple esophageal diverticula. A 72-year-old woman complained of prolonged dysphagia and chest pain. A barium esophagogram showed multiple esophageal diverticula and significant contraction of the lower esophagus just above the cardia. Esophagogastroduodenoscopy revealed a corkscrew-like appearance, with spiral contractions and diverticula. High-resolution manometry revealed that the integrated relaxation pressure was normal; premature contractions were observed in ≥20% of the swallowing wave; the distal contractile integral was normal. She was diagnosed with DES according to the Chicago classification v 3.0. As smooth muscle relaxants were not effective, we decided to perform peroral endoscopic myotomy (POEM) to eliminate persistent esophageal contraction. After POEM treatment, her symptoms were markedly improved, and the Eckardt score significantly decreased from 11 points to 1. An esophagogram after POEM showed that barium flowed promptly into the stomach. The multiple esophageal diverticula were considered to be the result of false pulsion diverticulosis caused by excessive internal esophageal pressure, and this represented the most severe form of DES. POEM could be a new curative strategy for the most severe DES cases with multiple diverticula.

Sleep disturbances in Japanese patients with inflammatory bowel disease and their impact on disease flare.

BACKGROUND: Several studies have reported a significant association between sleep disturbance and inflammatory bowel disease (IBD). The aim of the present study is to compare the clinical characteristics and the health-related quality of life (HR-QOL) of Japanese IBD patients with or without sleep disturbances, and to investigate the risk factors for disease flare in these patients. METHODS: IBD patients were asked to complete a self-administered questionnaire including the Pittsburg sleep quality index and the 8-item short-form health survey. The information about disease flare within 1 year from enrollment in the study was analyzed with a multiple logistic regression model to identify risk factors for IBD flare-ups. RESULTS: The prevalence of sleep disturbances was 44.1 % (60 out of 136 IBD patients). Use of sleep medications was significantly higher in IBD patients with sleep disturbances whereas use of immuno modulators was significantly higher in IBD patients without sleep disturbances. The scores from all HR-QOL domains were significantly lower in patients with sleep disturbances than in patients without sleep disturbances. Fifty-one patients (37.5 %) had disease flare within 1 year from enrollment in the study and sleep disturbances were identified as a significant risk factor for disease flare (OR 3.09, 95 % CI 1.47-6.43). CONCLUSIONS: Our results indicate that sleep disturbances are common in Japanese IBD patients and are associated with poorer HR-QOL. Since the presence of sleep disturbances is a significant risk factor for IBD flare-ups, we encourage physicians to perform a careful examination of sleep disturbances in IBD patients.