Hiroaki Zai

Development and evaluation of FSSG: frequency scale for the symptoms of GERD.

BackgroundThe aim of this study was to produce a simplified questionnaire for evaluation of the symptoms of gastroesophageal reflux disease (GERD).MethodsA total of 124 patients with an endoscopic diagnosis of GERD completed a 50-part questionnaire, requiring only “yes” or “no” answers, that covered various symptoms related to the upper gastrointestinal tract, as well as psychosomatic symptoms. The 12 questions to which patients most often answered “yes” were selected, and were assigned scores (never = 0; occasionally = 1; sometimes = 2; often = 3; and always = 4) to produce a frequency scale for symptoms of GERD (FSSG). Sensitivity, specificity, and accuracy of the FSSG questionnaire were evaluated in another group of patients with GERD and non-GERD. The usefulness of this questionnaire was evaluated in 26 other GERD patients who were treated with proton pump inhibitors for 8 weeks.ResultsWhen the cutoff score was set at 8 points, the FSSG showed a sensitivity of 62%, a specificity of 59%, and an accuracy of 60%, whereas a cutoff score of 10 points altered these values to 55%, 69%, and 63%. The score obtained using the questionnaire correlated well with the extent of endoscopic improvement in patients with mild or severe GERD.ConclusionsThis new questionnaire is useful for the objective evaluation of symptoms in GERD patients.

Monosodium l-glutamate added to a high-energy, high-protein liquid diet promotes gastric emptying

BACKGROUNDnFree glutamate activates taste receptors on nerves in the oral cavity to elicit a unique taste known as umami. Recently, umami taste receptors were also found in the gastric mucosa. Although reports suggest that mucosal receptors may respond to free glutamate to modulate gastric function, no evidence of any effect on gastric emptying has been documented.nnnOBJECTIVEnWe hypothesized that glutamate may act as a modulator of gastric function. We studied the effects of L-glutamate enrichment of a protein-rich liquid meal, and similar enrichment of an equicaloric carbohydrate meal or noncaloric water, on gastric emptying.nnnDESIGNnTen healthy men were enrolled. Nine of the 10 subjects included in the study ingested all test meals with and without monosodium L-glutamate (MSG), and the remaining subject ingested only the protein-rich meals with and without MSG. All experimental and control liquid meals included [1-(13)C]sodium acetate as a tracer. After a test meal or water was ingested, (13)C breath tests were performed to estimate gastric emptying.nnnRESULTSnMSG enrichment not only resulted in a significant decrease in the mathematically simulated half-excretion (emptying) time of a protein-rich meal, but also increased the area under the curve (%dose/h) significantly. In contrast, MSG had no significant effect on the gastric emptying of a carbohydrate meal or a noncaloric water meal.nnnCONCLUSIONSnEnrichment with MSG facilitated gastric emptying of a protein-rich meal exclusively, which suggests that free glutamate is important for protein digestion and may be helpful in the management of delayed gastric emptying.

Proton Pump Inhibitors Improve Acid-Related Dyspepsia in Gastroesophageal Reflux Disease Patients

It has been reported that proton pump inhibitors are more effective than H2 receptor antagonists in patients with functional dyspepsia. Dyspeptic symptoms that respond to proton pump inhibitors are classified as acid-related dyspepsia. A new questionnaire for assessing gastroesophageal reflux disease (GERD), the Frequency Scale for Symptoms of GERD, covers the 12 most common symptoms of GERD patients. A quantitative assessment of the changes of reflux symptoms and acid-related dyspepsia was made in GERD patients receiving proton pump inhibitor therapy. Sixty-eight GERD patients receiving proton pump inhibitor therapy completed the questionnaire before and after treatment for 8 weeks. There is a significant positive correlation between reflux symptoms and acid-related dyspepsia before and after therapy (rxa0=xa00.569 and rxa0=xa00.569; both P’sxa0<xa00.001) and acid-related dyspepsia in patients with both nonerosive and erosive GERD. We conclude that GERD patients suffer not only from reflux symptoms, but also from acid-related dyspepsia, and proton pump inhibitors improve both types of symptoms.

High-viscosity liquid meal accelerates gastric emptying.

Abstractu2002 Adding pectin to an elemental formula increases its viscosity through gelatinization, thus presumably preventing gastro‐oesophageal reflux and aspiration pneumonia. We investigated the influence of the viscosity of an elemental formula on gastric emptying. Eleven healthy volunteers underwent three tests at intervals of >1u2003week. After fasting for >8u2003h, each subject received a test meal (enteral nutrition solution, enteral solution plus pectin, or water). Then gastric emptying (continuous 13C breath test), gastro‐oesophageal intraluminal pressures, oesophageal pH, and blood levels of glucose, insulin and gastrin were all measured simultaneously. The gastric emptying coefficient was significantly increased by adding pectin to enteral nutrition (3.01u2003±u20030.10 vs 2.78u2003±u20030.10, meanu2003±u2003SE, Pu2003<u20030.05). The antral motility index was also significantly higher with pectin than without at 45–60u2003min and 60–75u2003min after the test meal (526u2003±u2003237 vs 6.5u2003±u20034.6u2003mmHgu2003s−1 and 448u2003±u2003173 vs 2.3u2003±u20032.3u2003mmHgu2003s−1 respectively; Pu2003<u20030.05). Plasma glucose was significantly higher with pectin than without it at 60u2003min after ingestion (141.5u2003±u20036.03 vs 125.8u2003±u20034.69u2003μmu2003mL−1, Pu2003<u20030.05). In healthy individuals, pectin increased the viscosity of enteral nutrition and accelerated gastric emptying.

Diagnosis of gastroesophageal reflux disease using a new questionnaire

Background and Aim: An early and accurate evaluation by a general practitioner is needed to screen out non‐gastroesophageal reflux disease (GERD) patients. A recent questionnaire (QUEST) highlighted problems with specificity and complexity, so the aim of the present study was to design a simplified questionnaire.

Rapid gastric emptying, rather than delayed gastric emptying, might provoke functional dyspepsia

It has been suggested that there could be three possible mechanisms of gastric dysfunction in patients with FD: (i) delayed gastric emptying, (ii) impaired gastric accommodation of food intake, and (iii) hypersensitivity to gastric distention. Postprandial fullness seems to be the most severe symptom in patients who report aggravation of their symptoms after meals. Therefore, it has been assumed that delayed gastric emptying and consequent prolonged antral distension could reduce hunger, increase satiety, and even cause gastric discomfort, all of which would pose a significant barrier to adequate nutrition.

Intragastric monosodium l-glutamate stimulates motility of upper gut via vagus nerve in conscious dogs

Monosodium l-glutamate (MSG) is a substance known to produce the umami taste. Recent studies indicate that MSG also stimulates a variety of activities in the gastrointestinal tract through its receptor in the gut, but no study has reported the activity in conscious large experimental animals. The aim of our study was to investigate whether direct intragastric MSG stimulates gut motility and to identify the mechanism in conscious dogs. Contractile response to intraluminal injection of MSG was studied in the fed and fasted states by means of chronically implanted force transducers. MSG (5, 15, 45, and 90 mM/kg) dissolved in water was injected into the stomach and duodenum in normal and vagotomized dogs. MSG solution was administered into the stomach before feeding, and gastric emptying was evaluated. Several inhibitors of gastrointestinal motility (atropine, hexamethonium, and granisetron) were injected intravenously before MSG administration to the stomach. The effect of MSG was investigated in Pavlov (vagally innervated corpus pouch), Heidenhain (vagally denervated corpus pouch), and antral pouch (vagally innervated) dogs. Upper gut motility was significantly increased by intragastric MSG but not significantly stimulated by intraduodenal MSG. Intragastric MSG (45 mM/kg) stimulated postprandial motility and accelerated gastric emptying. MSG-induced contractions were inhibited by truncal vagotomy, atropine, hexamethonium, and granisetron. Gut motility was increased by intrapouch injection of MSG in the Pavlov pouch, but it was not affected in the Heidenhain or antral pouch dogs. We conclude that intragastric MSG stimulates upper gut motility and accelerates gastric emptying. The sensory structure of MSG is present in the gastric corpus, and the signal is mediated by the vagus nerve.

Gastric Schwannomas Show an Obviously Increased Fluorodeoxyglucose Uptake in Positron Emission Tomography: Report of Two Cases

Schwannomas are tumors originating from any nerve that has a Schwann cell sheath. Gastrointestinal (GI) schwannomas represent only 3% of all GI mesenchymal tumors. The stomach is the most common site of GI schwannomas, and schwannomas account for 0.2% of all gastric neoplasms. This report presents two cases of gastric schwannomas showing increased [18F]fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET; maximum standardized uptake value 7.10 and 6.05). Additional immunohistochemical staining of glucose transporter type 1 (GLUT1) and the autocrine motility factor (AMF) was conducted after the tumors were resected, to identify the mechanism that increased FDG uptake on PET. Immunohistochemical expression of AMF was positive in both cases, whereas GLUT1 was negative. Autocrine motility factor is also known as phosphoglucose isomerase. However, the mechanism by which FDG is accumulated in schwannoma cells is uncertain, and may be related to intracellular glycolytic activity.

Monosodium glutamate stimulates secretion of glucagon‐like peptide‐1 and reduces postprandial glucose after a lipid‐containing meal

Monosodium l‐glutamate (MSG) is known to influence the endocrine system and gastrointestinal (GI) motility. The mechanism of postprandial glycemic control by food in the GI tract is mostly unknown and of great interest.

Investigation of Gastric Emptying Disorders in Patients with Functional Dyspepsia Reveals Impaired Inhibitory Gastric Emptying Regulation in the Early Postcibal Period

Background/Aims: The aim of the study was to investigate gastric emptying profiles in patients with postprandial distress syndrome (PDS) as a means to understand relationships between gastric emptying and dyspepsia. Methods: Gastric emptying times were measured using a 13C breath test. In addition to comparisons of 13C half excretion times (t 1/2 ex) between patients with PDS and healthy subjects, gastric emptying (%dose/h) curves were analyzed using a multipeak curve-fitting technique, and fitted curves were differentiated to measure the slope of curves for each time point. Results: (1) During the early postcibal period, the slope of %dose/h curves in 27% of patients with PDS was larger than the average slope derived from healthy subjects. The t 1/2 ex was also higher in these patients relative to healthy subjects. (2) During the midpostcibal period, the slope of %dose/h curves in 36% of PDS patients was larger than the average slope derived from healthy subjects. There was a trend toward lower t 1/2 ex values for these patients relative to control subjects. (3) When t 1/2 ex was calculated overall, however, there was no significant difference between healthy subjects and patients with PDS. Conclusion: Our findings document abnormal gastric outflow in patients with PDS. In some patients, there appears to be a significant correspondence between PDS-related dyspepsia and accelerated gastric emptying in the early postcibal period, whereas other patients showed a similar correspondence between dyspepsia and impaired inhibitory gastric emptying regulation in the midpostcibal period.