Measurement of exciton diffusion in a well-defined donor/acceptor heterojunction based on a conjugated polymer and cross-linked fullerene derivative.

We designed a well-defined donor/acceptor heterojunction for measuring exciton diffusion lengths in conjugated polymers. To obtain an insoluble electron acceptor layer, a new cross-linkable fullerene derivative (bis-PCBVB) was synthesized by functionalizing [6,6]-diphenyl-C62-bis(butyric acid methyl ester) (bis-PCBM) with two styryl groups. The spin-coated bis-PCBVB film was cross-linked in situ by heating at 170 °C for 60 min. Surface characterizations by UV-visible absorption, atomic force microscopy, and photoelectron yield spectroscopy revealed that a smooth and solvent-resistant film (p-PCBVB) was obtained. In bilayer films with a donor conjugated polymer, poly[2,7-(9,9-didodecylfluorene)-alt-5,5-(4',7'-bis(2-thienyl)-2',1',3'-benzothiadiazole)] (PF12TBT), spin-coated on top of the p-PCBVB acceptor layer, the photoluminescence (PL) of the PF12TBT was effectively quenched. This is because the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of the p-PCBVB film are nearly the same as those of the parent bis-PCBM spin-coated film. On the basis of the PL quenching results, the exciton diffusion length and exciton diffusion coefficient in the PF12TBT were evaluated to be 11 nm and 9.8 × 10(-4) cm(2) s(-1), respectively.

Effects of mosapride on esophageal motor activity and esophagogastric junction compliance in healthy volunteers.

BACKGROUND: The effects of the prokinetic drug mosapride on esophageal motor activity vary at standard doses. In addition to esophageal motor activities, compliance of the esophagogastric junction (EGJ) is important for prevention of gastroesophageal reflux. However, the effects of mosapride on EGJ compliance have not been reported. Here, we investigated the effects of high-dose mosapride on esophageal motor activities and EGJ compliance. METHODS: Nine healthy volunteers were enrolled in the study. Peristaltic esophageal contraction and lower esophageal sphincter pressures before and after administration of 40 mg mosapride were examined by high resolution esophageal manometry. Esophageal compliance was also investigated by intra-esophageal impedance planimetry (EndoFLIP(®)). RESULTS: High-dose mosapride augmented peristaltic contractions, especially in the distal esophageal segments (P < 0.05). The mean resting lower esophageal sphincter pressure was elevated from 25.0 mmHg before administration to 28.9 mmHg after (P < 0.05). In addition, mosapride significantly reduced EGJ compliance (P < 0.05). CONCLUSIONS: Mosapride at 40 mg augmented esophageal motor activities and reduced EGJ compliance in healthy volunteers.

Generation of Gastroesophageal Reflux Disease Symptoms During Esophageal Acid Infusion With Concomitant Esophageal pH Monitoring in Healthy Adults.

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.

Continuous imaging of esophagogastric junction in patients with reflux esophagitis using 320-row area detector CT: a feasibility study.

BACKGROUND AND AIM: The function of the lower esophageal sphincter (LES) is evaluated using an esophageal manometric study. However, information regarding the surrounding organs is difficult to obtain with use of a sensor catheter. We investigated the utility of 320-row area detector computed tomography (CT) to evaluate morphological changes of the esophagogastric junction and surrounding organs. METHODS: The study subjects were 18 healthy volunteers and 29 patients with reflux esophagitis (RE). Immediately after swallowing a diluted contrast agent, continuous imaging of the esophagogastric junctional area was performed for 15 s. Using CT images, the presence or absence of esophageal hiatal hernia, His angle before and after swallowing, size of the diaphragmatic hiatus, morphologically identified-LES (MI-LES) length, intraluminal horizontal area of MI-LES during relaxation phase, MI-LES thickness, abdominal esophagus length, subcutaneous fat area, visceral fat area, and esophagogastric junction fat area were evaluated. RESULTS: Analysis of CT images showed more frequent occurrence of hiatal hernia, greater His angle, and a larger diaphragmatic hiatus in patients with severe RE, while the lengths of MI-LES and abdominal esophagus were shorter in those patients. Visceral and esophagogastric junction fat areas tended to be greater in patients with RE. In all subjects, the posterior wall of the MI-LES was thicker than the anterior wall. CONCLUSION: Continuous imaging with 320-row area detector CT is useful to evaluate morphological changes in the esophagogastric junction area in both normal individuals and patients with reflux esophagitis.

Efficacy of pectin solution for preventing gastro-esophageal reflux events in patients with percutaneous endoscopic gastrostomy.

The aim of this study was to determine the efficacy of pectin solution, which increases the viscosity of liquid nutrient, for prevention of gastro-esophageal reflux in comparison with half-solid nutrient. The subjects were 10 elderly patients undergoing percutaneous endoscopic gastrostomy feeding. Twenty-four-hour esophageal multichannel intraluminal impedance and pH testing was performed during intake of half-solid nutrient and a combination of pectin solution and liquid nutrient. During 4 h after delivery, there was no significant difference in the total number of gastro-esophageal reflux events between the feeding of the half-solid nutrient and the combination of pectin solution and liquid nutrient (5.7 ± 1.2 vs 5.3 ± 1.0/4 h). Acidic reflux after delivery of the half-solid nutrient was significantly more frequent than that after delivery of the combination of pectin solution and liquid nutrient (80.7% vs 60.4%, p = 0.018). The incidence of gastro-esophageal reflux reaching the upper portion of the esophagus tended to be higher during delivery of the half-solid nutrient than during delivery of the combination of pectin solution and liquid nutrient (47.4% vs 34.0%, p = 0.153). In conclusion, the usage of pectin solution combined with liquid nutrient is effective for preventing acidic gastro-esophageal reflux and gastro-esophageal reflux reaching the upper portion of the esophagus.

Radially asymmetric gastroesophageal acid reflux in the distal esophagus: examinations with novel pH sensor catheter equipped with 8 pH sensors.

BACKGROUND: Esophageal mucosal breaks in patients with Los Angeles (LA) grade A or B esophagitis are mainly found in the right anterior wall of the distal esophagus. The aim of this study was to reveal radial acid exposure in the distal esophagus and determine whether radial asymmetry of acid exposure is a possible cause of radially asymmetric distribution of the lesions. METHODS: We developed a novel pH sensor catheter using a polyvinyl chloride catheter equipped with 8 antimony pH sensors radially arrayed at the same level. Four healthy volunteers, 5 patients with non-erosive reflux disease (NERD), and 10 with LA grade A or B esophagitis were enrolled. The sensors were set 2 cm above the upper limit of the lower esophageal sphincter, and post-prandial gastroesophageal acid reflux was monitored for 3 h with the subjects in a sitting position. RESULTS: We successfully examined radial acid exposure in the distal esophagus in all subjects using our novel pH sensor catheter. Radial variations of acid exposure in the distal esophagus were not observed in the healthy subjects. In contrast, the patients with NERD and those with reflux esophagitis had radial asymmetric acid exposure that was predominant on the right wall of the distal esophagus. In the majority of patients with reflux esophagitis, the directions of longer acid exposure coincided with the locations of mucosal breaks. CONCLUSIONS: Radial acid exposure could be examined using our novel 8-channel pH sensor catheter. We found that the directions of longer acid exposure were associated with the locations of mucosal breaks.

Effects of Rikkunshito (TJ-43) on Esophageal Motor Function and Gastroesophageal Reflux.

BACKGROUND/AIMS: Rikkunshito (TJ-43), an herbal medicine, has been demonstrated to relieve gastroesophageal reflux symptoms. However, the effects of TJ-43 on esophageal motor functions have not been fully determined. This double-blind crossover study was performed to investigate the effects of TJ-43 on esophageal motor functions and gastroesophageal reflux. METHODS: The subjects were 10 normal male volunteers. Lower esophageal sphincter pressure and esophageal body peristaltic contractions with and without 1-week administration of TJ-43 were examined in a crossover fashion. Post-prandial gastroesophageal reflux was also determined using a multi-channel impedance pH dual monitor. RESULTS: TJ-43 at a standard dose of 7.5 g/day did not significantly augment esophageal peristaltic contraction pressure measured in the proximal, middle and distal segments of the esophagus, whereas increment of resting lower esophageal sphincter pressure was observed in a supine position. In addition, TJ-43 administration did not decrease post-prandial gastroesophageal acid, non-acid reflux events or accelerate esophageal clearance time. CONCLUSIONS: TJ-43 at a standard dose did not have a significant effect on esophageal motor activity or gastroesophageal reflux in healthy adults.

Influence of Full-body Water Immersion on Esophageal Motor Function and Intragastric Pressure.

BACKGROUND/AIMS: In Japan, it is customary to take a daily bath during which the body is immersed in water to the neck. During full-body immersion, hydrostatic pressure is thought to compress the chest and abdomen, which might influence esophageal motor function and intra-gastric pressure. However, whether water immersion has a significant influence on esophageal motor function or intragastric pressure has not been shown. The aim of this study was to clarify the influence of full-body water immersion on esophageal motor function and intragastric pressure. METHODS: Nine healthy male volunteers (mean age 40.1 ± 2.8 years) were enrolled in this study. Esophageal motor function and intragastric pressure were investigated using a high-resolution 36-channel manometry device. RESULTS: All subjects completed the study protocol. Intragastric pressure increased significantly from 4.2 ± 1.1 to 20.6 ± 1.4 mmHg with full-body water immersion, while the lower esophageal high pressure zone (LEHPZ) value also increased from 20.5 ± 2.2 to 40.4 ± 3.6 mmHg, with the latter being observed regardless of dietary condition. In addition, peak esophageal peristaltic pressure was higher when immersed as compared to standing out of water. CONCLUSIONS: Esophageal motor function and intragastric pressure were altered by full-body water immersion. Furthermore, the pressure gradient between LEHPZ and intragastric pressures was maintained at a high level, and esophageal peristaltic pressure was elevated with immersion.

Different sex-related influences of eating habits on the prevalence of reflux esophagitis in Japanese.

BACKGROUND AND AIM: Many types of food have been shown to affect lower esophageal sphincter pressure and esophageal motor function, and thus, the prevalence of reflux esophagitis. The present study was performed to clarify the different eating habits that predominantly affect the prevalence of reflux esophagitis in Japanese. METHODS: The study included 2303 individuals (males: 1599, females: 704, mean age: 49.9 years) who underwent upper gastrointestinal endoscopy for gastric cancer screening. The daily dietary contents of the patients were analyzed using a self-administered questionnaire. RESULTS: A total of 201 patients had endoscopically-proven reflux esophagitis, and the percentage of males with reflux esophagitis was significantly higher than their female counterparts (11.3% vs 2.8%). The body mass indexes of individuals with reflux esophagitis were significantly higher than those without, both for males and females. Total energy intake was the most important risk factor for the occurrence of reflux esophagitis in males, but the food content was not a significant risk factor. Dietary habit did not affect the prevalence of reflux esophagitis in the female patients. The age and height of females with reflux esophagitis significantly exceeded those of females without reflux esophagitis, and were independent risk factors for the occurrence of reflux esophagitis only in the female patients. CONCLUSION: There is a sex-related difference in the influence of eating habits on the prevalence of reflux esophagitis in Japanese.

A case of eosinophilic esophagitis with atypical clinical course.

Eosinophilic esophagitis is a rare chronic disease that mainly occurs in middle-aged males. Treatment with a glucocorticoid and/or proton pump inhibitor is usually necessary to relieve unpleasant symptoms. An 83-year-old female patient with dysphagia and heartburn was diagnosed with eosinophilic esophagitis based on endoscopic findings, while histological examination identified dense infiltration of intraepithelial eosinophils. The symptoms and eosinophil infiltration spontaneously disappeared without any treatment approximately 2 months later. No obvious lifestyle or dietary changes to explain elimination of possible antigens were identified in this case. We report an atypical case of eosinophilic esophagitis with spontaneous regression.

Usefulness of catheterless radiotelemetry pH monitoring system to examine the relationship between duodenal acidity and upper gastrointestinal symptoms.

BACKGROUND AND AIM: To clarify the usefulness of a newly designed method for measuring intraduodenal pH to examine the relationship between duodenal acidity and upper gastrointestinal symptoms during intragastric acid infusion. METHODS: The study subjects were six healthy volunteers. A Bravo pH capsule with thread fixed to the gastric wall was endoscopically introduced into the second portion of the duodenum, and intraduodenal acidity was measured during intragastric infusion of 300 mL of 0.1 mol/L hydrochloric acid or pure water through an elemental diet tube. The severity of several upper gastrointestinal symptoms were assessed by using a 10-cm visual analogue scale every 2 min for up to 30 min, and the area under the severity scale-time curve (cm×min.) were calculated. RESULTS: The percentage time during 30 min when the intraduodenal pH was <4.0 and was significantly greater than during water infusion (61.4±6.1% vs 24.8±6.5%). Several upper gastrointestinal symptoms were observed during acid infusion (acid vs water epigastric heaviness, 29.1±12.0 vs 2.7±1.4; dull epigastric pain, 8.8±4.9 vs 0.7±0.7 cm×min/30 min). Intraduodenal pH below 4.0 was correlated with the severity of dull pain in the stomach (R(2)=0.342, P=0.044). CONCLUSION: The newly designed intraduodenal pH monitoring by using catheterless radiotelemetry system is useful to examine the relationship between duodenal acidity and upper gastrointestinal symptoms.

Effects of mosapride on esophageal functions and gastroesophageal reflux.

BACKGROUND AND AIM: A substantial number of patients with gastroesophageal reflux disease show symptomatic resistance to high-dose proton pump inhibitors. In those cases, prokinetics are possible candidates for treatment. The aim of the present study was to determine whether mosapride, a prokinetic agent, stimulates esophageal functions, and prevents acidic and non-acidic gastroesophageal reflux. METHODS: Normal volunteers (nine and 13 for two experiments, respectively) were enrolled. Salivary secretion, esophageal peristaltic contractions, and resting lower esophageal sphincter pressure with and without mosapride administration were recorded using a cross-over protocol. Post-prandial acidic and non-acidic reflux levels were also recorded. RESULTS: Mosapride at a standard dose of 15 mg/day did not stimulate salivary secretion or any esophageal motor functions. It also failed to prevent acidic and non-acidic post-prandial gastroesophageal reflux. CONCLUSIONS: Mosapride at 15 mg/day, a standard dose in Japan, did not change the esophageal motility and salivary secretion in healthy volunteers. Future study on a larger number of individuals with higher dose of mosapride is worthwhile.

Effects of anti-hypertensive drugs on esophageal body contraction.

AIM: To clarify the effects of anti-hypertensive drugs on esophageal contraction and determine their possible relationship with gastro-esophageal reflux disease. METHODS: Thirteen healthy male volunteers were enrolled. Esophageal body peristaltic contractions and lower esophageal sphincter (LES) pressure were measured using high resolution manometry. All subjects were randomly examined on four separate occasions following administrations of nifedipine, losartan, and atenolol, as well as without any drug administration. RESULTS: Peristaltic contractions by the esophageal body were separated into three segments by two troughs. The peak peristaltic pressures in the mid and lower segments of the esophageal body under atenolol administration were significantly higher than those without medication in a supine position. On the other hand, peristaltic pressures under nifedipine administration were lower than those observed without drug administration. Losartan did not change esophageal body peristalsis. Atenolol elevated LES pressure and slowed peristaltic wave transition, while the effects of nifedipine were the opposite. CONCLUSION: Among the anti-hypertensive drugs tested, atenolol enhanced esophageal motor activity, which was in contrast to nifedipine.

Half-solidification of nutrient does not decrease gastro-esophageal reflux events in patients fed via percutaneous endoscopic gastrostomy.

BACKGROUND & AIMS: Percutaneous endoscopic gastrostomy (PEG) tube feeding is widely used for patients with swallowing dysfunction, and aspiration pneumonitis induced by reflux of gastric contents is one of the most frequent and life-threatening events in such patients. We performed this study to clarify the effect of half-solidification of nutrient on gastro-esophageal reflux (GER) of acidic and non-acidic gastric contents in patients with PEG. METHODS: The subjects were 14 elderly patients undergoing PEG feeding (female: 11, mean age 83.1 y). Twenty-four hour esophageal multichannel intraluminal impedance (MII) and pH (MII-pH) monitoring were performed during and after feeding with half-solid and liquid nutrient, respectively. The numbers of GER events during 4h after the start of feeding were compared. RESULTS: There was no significant difference in the total number of GER events between half-solid nutrient feeding and liquid nutrient feeding (5.6+/-1.5 vs. 6.6+/-1.5). The number of acid reflux events after half-solid nutrient feeding tended to be higher than that after liquid nutrient feeding (1.9+/-1.1 vs. 1.4+/-0.8). CONCLUSION: Half-solidification of nutrition does not appear to be effective for preventing GER caused by liquid PEG feeding.

Esophageal epithelial surface in patients with gastroesophageal reflux disease: an electron microscopic study.

AIM: To investigate the intercellular spaces between the most superficially located esophageal epithelial cells in patients with gastroesophageal reflux disease (GERD). METHODS: Eighteen patients with erosive esophagitis, 10 patients with non-erosive reflux disease (NERD), and 18 normal asymptomatic volunteers were enrolled. Biopsy specimens were obtained from the lower esophageal mucosa without ulcer or erosion. Scanning electron microscopy was employed to investigate the tightness of the superficial cellular attachment. RESULTS: The intercellular space between the most superficially located epithelial cells in patients with erosive esophagitis or NERD was not different from that in asymptomatic healthy individuals. CONCLUSION: Widened luminal intercellular spaces of esophageal superficial epithelium are not responsible for the induction of reflux symptoms in patients with GERD.

Consumption of uncooked deer meat as a risk factor for hepatitis E virus infection: an age- and sex-matched case-control study.

It was reported previously food-borne transmission of hepatitis E virus (HEV) to humans from deer meat. The present study attempted to clarify whether eating uncooked deer meat is a major epidemiological risk factor for HEV infection in Kasai, a city in western Japan. In total, 45 volunteer subjects with experience of eating raw deer meat were enrolled. An equivalent number of people from the same area who had never eaten raw deer meat served as controls. The subjects and controls had comparable age and sex distributions. Serum anti-HEV IgG and anti-hepatitis A virus (HAV) IgG levels were measured in all 90 volunteers. There was no significant difference in age, overseas travel history, or rate of anti-HAV antibody positivity between the subjects and controls. Eight (17.7%) of the subjects but only one (2.2%) of the controls had measurable serum anti-HEV IgG levels (P = 0.014). Anti-HAV prevalence did not differ between the anti-HEV-positive and negative groups. The results suggest that eating uncooked deer meat is an epidemiological risk factor for HEV infection in the studied area. In countries such as Japan where deer meat is sometimes eaten raw, attention must be paid to this route of HEV infection.