T. T. Liu

Evidence for neurotrophic factors associating with TRPV1 gene expression in the inflamed human esophagus

Background  Transient receptor potential vanilloid‐1 (TRPV1) receptor has been implicated in the mechanism of acid induced inflammation in gastro‐esophageal reflux disease (GERD). It has been demonstrated that the increase in nerve growth factor (NGF) and glial derived neurotrophic factor (GDNF) was associated with the increased expression of TRPV1. We aimed to determine whether expression of TRPV1 was increased in severe inflamed human esophagus, and to test the hypothesis whether the expression of TRPV1 was mediated by neurotrophic factors such as NGF and GDNF.

Effects of capsaicin-containing red pepper sauce suspension on esophageal secondary peristalsis in humans

Background  Capsaicin‐sensitive afferents have been implicated in the modulation of gastrointestinal sensorimotor functions. Secondary peristalsis is important for the clearance of retained refluxate or material from the esophagus. The aim of this study was to evaluate the effects of capsaicin‐containing red pepper sauce suspension on esophageal secondary peristalsis in healthy adults.

Effects of mosapride on esophageal secondary peristalsis in humans

Background  Secondary peristalsis is important for the clearance of refluxate or retained food bolus from the esophagus. Mosapride is a prokinetic agent that enhances GI motility by stimulating 5‐hydroxytrypatamine4 (5‐HT4) receptors, but its effects on secondary peristalsis are yet unclear in humans. We aimed to investigate the effect of a 5‐HT4 agonist mosapride on esophageal distension‐induced secondary peristalsis in normal subjects.

Electrogastrography Differentiates Reflux Disease With or Without Dyspeptic Symptoms

Many patients with gastroesophgeal reflux disease (GERD) may also have overlapping symptoms of dyspepsia. This study was to examine if GERD patients could be separated into meaningful groups based on their gastric myoelectrical characteristics. The study included 20 GERD patients with dyspeptc symptoms (GERD+) and 17 patients with GERD. Gastric myoelectrical activity was assessed using cutaneous electrodes to record electrogastrograms (EGGs). The GERD+ patients ingested smaller volumes of water compared to patients with GERD (P<0.05). At baseline, the percentage of gastric myoelectrical power in the normal 3-cpm range was significantly less in patients with GERD+ compared with the GERD subjects (P = 0.01). Power in the bradygastria range was significantly greater in patients with GERD+ (P = 0.005). The GERD+ group had a significant increase in the percentage of power in the tachygastria range later after ingesting the water load (P < 0.01). In conclusion, this study has shown that more gastric dysrhythmias were detected in the GERD+ patients accompanied with altered perception of stomach fullness.

Effects of lidocaine on esophageal secondary peristalsis in humans

Background  Secondary peristalsis is important for the clearance of retained food bolus or refluxate from the esophagus. Lidocaine has been used to evaluate the role of mucosa‐mediating pathways of esophageal reflexes in animal model, but its effects on esophageal secondary peristalsis are yet unclear in humans. We aimed to investigate whether esophageal secondary peristalsis can be affected by intraluminal infusion of lidocaine into the esophagus.

Esophageal solid bolus transit: studies using combined multichannel intraluminal impedance and manometry in healthy volunteers.

The purpose of this study is to apply combined multichannel intraluminal impedance and esophageal manometry (MII-EM) to test esophageal function during solid swallowing in a normal healthy population. We determined whether combined MII-EM with solid bolus is more sensitive than that with viscous bolus in the detection of motility abnormality. Eighteen healthy volunteers (11 men and 7 women; mean age 22 years, range 20-26 years) underwent combined MII-EM with a catheter containing four impedance-measuring segments and five solid-state pressure transducers. Each subject received 10 viscous and 10 solid materials. Tracings were analyzed manually for bolus presence time, total bolus transit time, contraction amplitude, duration, and onset velocity. Three hundred and sixty swallows including viscous and solid materials were analyzed. Contraction amplitude for the viscous swallows was higher at 20 cm above the lower esophageal sphincter (LES) (P= 0.049) but lower at 15 cm above the LES (P < 0.001). Duration of contractions for the solid swallows was longer at 15 cm (P= 0.002) and 10 cm above the LES (P= 0.011) compared with viscous swallows. The total bolus transit time for solid was significantly shorter than that for viscous boluses (6.8 vs. 7.7 seconds, P < 0.001). Bolus presence time appeared to be similar between viscous and solid boluses (except in the proximal esophagus). The percentage of swallows with ineffective peristalsis by manometry, as well as those with incomplete bolus transit by impedance, did not differ between viscous and solid swallows. The proportion of manometrically ineffective solid swallows with incomplete bolus transit was greater than that of viscous swallows (62.1% vs. 34.8%, P= 0.05). Application of solid boluses may potentially enhance diagnostic capability of esophageal function testing. Solid boluses can be regarded as a valuable complement to viscous boluses in the detection of esophageal motility abnormalities when applied with combined MII-EM.

Influence of repeated infusion of capsaicin-contained red pepper sauce on esophageal secondary peristalsis in humans.

The transient receptor potential vanilloid 1 has been implicated as a target mediator for heartburn perception and modulation of esophageal secondary peristalsis. Our aim was to determine the effect of repeated esophageal infusion of capsaicin‐contained red pepper sauce on heartburn perception and secondary peristalsis in healthy adults.

Control of esophageal distension-induced secondary peristalsis by the GABA(B) agonist baclofen in humans.

Background  Secondary peristalsis is important for the clearance of retained food bolus or refluxate from the esophagus. The effects of the gamma aminobutyric acid receptor type B (GABAB) agonist on secondary peristalsis remain unclear in humans. We aimed to investigate the effect of a GABAB agonist baclofen on esophageal secondary peristalsis.

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

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.

Disease progression in non-erosive reflux disease (NERD): impact of initial esophageal acid exposure

We investigated the 5-year clinical course in a cohort of patients with typical reflux symptoms and negative endoscopy. Prospective follow-up was conducted in patients with non-erosive reflux disease (NERD) for at least 5 years after initial evaluation with esophageal pH monitoring and upper gastrointestinal endoscopy. Within the last year of follow-up, reflux symptoms occurred in 27 of the 30 patients (90%). Twenty-five of twenty-seven symptomatic patients (93%) were on acid suppression therapy. The majority of our patients (70%) remained unchanged regarding their endoscopic status over 5 years. Progression to erosive esophagitis occurred in four patients with Los Angeles (LA) A (13%), three patients with LA B (10%), and two patients with LA C (7%). The presence of pathological acid exposure did not alter the presence of reflux symptoms over 5 years. Disease progression to erosive esophagitis occurred more frequently in patients with pathological acid exposure than those without pathological acid exposure (P= 0.025). Most NERD patients have symptoms and require acid suppression therapy 5 years after their initial diagnosis. Initial pathological acid exposure does not influence the use of acid suppression; however, it does influence the progression of NERD within 5 years of follow-up.