The breath test system involving a novel tracer, ¹³C-uracil and Wagner-Nelson analysis: comparison with the gastric emptying scintigraphy.

BACKGROUND/AIMS: In this pilot study, a new breath test system for gastric emptying study has been proposed. METHODOLOGY: The system involves 13C-uracil as a novel tracer and the Wagner-Nelson method for analyzing breath data. RESULTS: In three healthy volunteers, the new breath system allowed quantification of gastric emptying profiles as accurately as the scintigraphic technique. CONCLUSIONS: Further validation studies with a lager sample size are needed.

Effects of proton pump inhibitors on gastric emptying: a systematic review.

The proton pump inhibitor (PPI) is widely used for the treatment of gastroesophageal reflux disease, peptic ulcer diseases, and functional dyspepsia. The pathogenesis of these acid-related and/or functional upper gastrointestinal disorders is potentially associated with abnormal gastric emptying. To date, variable effects of PPIs on gastric emptying have been reported. Therefore, it is relevant to gather and analyze published information on this topic. A systematic literature search has been performed, showing that the delaying effect of PPIs on gastric emptying of solid meals is consistent, whereas the effect of PPIs on the emptying of liquids is inconsistent. The underlying mechanisms whereby PPIs may affect gastric emptying have been discussed, most of which still remain hypothetic. Gastric emptying of solids involves a process of peptic hydrolysis. PPIs impair the hydrolytic digestion by inhibiting acid-dependent peptic activity, thereby delaying the solid emptying. Gastric emptying of liquids largely depends on volume and energy density of intragastric contents. PPIs variably modify the volume and the energy density by reducing gastric fluid secretion, thereby modifying the liquid emptying in an unpredictable manner. Hypergastrinemia has been considered to delay gastric emptying, but it seems of minor importance in the regulation of gastric emptying during PPI use. The delayed emptying of solids due to PPI therapy may have clinical implications in the management of gastroesophageal reflux disease, functional dyspepsia, as well as diabetes.

Form of gastric air bubble is associated with gastroesophageal reflux symptoms.

BACKGROUND/AIMS: Gastric bubble is present in approximately 70% of normal chest and abdominal radiograph. Most swallowed air is regurgitated and belching is a physiological phenomenon to expel ingested gas from the stomach and is a common symptom in normal adults. In the present study it was investigated whether gastric bubble detected on abdominal radiograph is associated with GERD symptoms. METHODOLOGY: All of the patients who first attend our hospital were asked to respond the F-scale questionnaire regardless of their chief complaints to diagnose GERD. Plain abdominal films in the erect position were used to measure the size of gastric bubble and to classify the form of gastric bubble into four groups: dome-type; irregular-type; stomach-type; and undetected-type. The quantity of gastric bubble (gastric bubble score) was determined as the pixel value on image collected from hospital's digital database. RESULTS: The gastric bubble score of irregular-type was significant lower than that of dome-type and stomach-type. GERD was most frequently detected in stomach-type group, followed by undetected-type, irregular-type, and dome-type. The mean score of F-scale was significantly higher in stomach-type than in dome-type. CONCLUSIONS: It is concluded that gastric bubble detected on plain abdominal films is an informative marker for evaluating the functional disorder of upper digestive tracts. Physicians have to recognize the importance of plain films of the abdomen in the diagnostic process of GERD.

Is the metabolism of toast alcohol beverages influenced by a meal taken five minutes later?

Alcohol is commonly consumed with, or soon after, a meal that affects gastric emptying and thus, absorption and metabolism of alcohol. The aim of this study is to evaluate the effect of liquid test meal ingested soon after, alcohol ingestion on alcohol metabolism, as is common in the social setting. First, a 100 mL of water containing of 80 mg of 13C-ethanol was administrated orally in 7 healthy subjects, and 200 mL of liquid meal (200 kcal) was administrated 5 min after alcohol ingestion. Breath samples were taken at baseline and at 10-min interval for 150 min. Next, 13C-ethanol breath test was performed without ingestion of liquid meal. Cmax was decreased after ingestion of liquid meal, whereas Tmax was unchanged. The descending gradient of 13CO2 excretion curves after ingestion of liquid meal is parallel to that without liquid meal, while the ascending gradient of 13CO2 excretion curves in the first 10 min had a tendency to be greater after ingestion of liquid meal than without ingestion of liquid meal. A significant delay in breath 13CO2 excretion after ingestion of liquid meal was found and the AUC values were lower after ingestion of liquid meal in each time point, indicating that liquid meal ingested soon after alcohol ingestion may not affect elimination but absorption and/or metabolism of a small amount of alcohol.

Extensive atrophic gastritis linked to increased levels of intraluminal hydrogen gas.

BACKGROUND/AIMS: Gastric acid plays an important part in the prevention of bacterial colonization of the gastrointestinal tract. If these bacteria have an ability of hydrogen (H2) fermentation, intraluminal H2 gas might be detected. We attempted to measure the intraluminal H2 concentrations to determine the bacterial overgrowth in the gastrointestinal tract. METHODOLOGY: Studies were performed in 647 consecutive patients undergoing upper endoscopy. At the time of endoscopic examination, we intubated the stomach and the descending part of the duodenum without inflation by air, and 20 ml of intraluminal gas samples of both sites was collected through the biopsy channel. Intraluminal H2 concentrations were measured by gas chromatography. RESULTS: Over all, intragastric and intraduodenal H2 gas was detected in 566 (87.5%) and 524 (81.0%), respectively. The mean values of intragastric and intraduodenal H2 gas were 8.5 +/- 15.9 and 13.2 +/- 58.0 ppm, respectively. The intraduodenal H2 level was increased with the progression of atrophic gastritis, whereas the intragastric H2 level was the highest in patients without atrophic gastritis. CONCLUSIONS: The intraduodenal hydrogen levels were increased with the progression of atrophic gastritis. It is likely that the influence of hypochlorhydria on bacterial overgrowth in the proximal small intestine is more pronounced, compared to that in the stomach.

No relationship between plasma desacyl-ghrelin levels and rabeprazole-related delay in gastric emptying : controlled study in healthy volunteers.

BACKGROUND AND OBJECTIVE: Recent studies have indicated that rabeprazole, a proton pump inhibitor, delays gastric emptying. However, the mechanism of action remains unclear. We conducted this study to clarify whether desacyl-ghrelin (the inactive form of the endogenous growth hormone secretagogue receptor ghrelin) is involved in rabeprazole-induced changes in gastric motor function. METHODS: Twelve healthy males underwent (13)C-acetate breath tests to evaluate gastric emptying of a liquid meal twice after administration of rabeprazole 20 mg/day for 3 days or no medication (control). Gastric emptying was evaluated by two parameters: half-emptying time and time to peak (13)CO(2) excretion. Plasma desacyl-ghrelin levels were measured in blood samples collected at three time points: immediately pre-test and 1 and 2 hours after ingestion of the test meal. RESULTS: Rabeprazole significantly delayed gastric emptying of the liquid meal. However, plasma desacyl-ghrelin levels after ingestion of the liquid meal showed little difference before or after rabeprazole administration. CONCLUSION: The results indicate that desacyl-ghrelin was not associated with changes in gastric emptying caused by rabeprazole.

Reliability of the time to maximal [13CO2] excretion and the half-[13CO2] excretion time as a gastric emptying parameter: assessments using the Wagner-Nelson method.

In the [(13)C]-octanoate breath test, two popular parameters have been used to quantify gastric emptying rates, namely the time to the maximal [(13)CO(2)] excretion (T(max)) and the time to the half-[(13)CO(2)] recovery (T(1/2b)). Although each of T(max) and T(1/2b) is closely correlated with the scintigraphic half-emptying time, the two parameters occasionally indicate different judgments on a gastric emptying rate. In this study, to clarify which of the two parameters is more reliable, T(max) and T(1/2b) were compared to the "reference" parameters calculated using the Wagner-Nelson method, which allows accurate estimation of a time-course of gastric emptying from breath data. Ten healthy male volunteers underwent the breath test after ingestion of a muffin meal (320 kcal) containing 100 mg [(13)C]-octanoate. Breath samples were collected at 15-min intervals for 6 h. According to the conventional analytical algorithm, T(max) and T(1/2b) were mathematically calculated. By applying Wagner-Nelson analysis to the breath test, the time-percent gastric retention curve was generated and the half-emptying time (T(1/2WN)) was determined. T(1/2WN) was more closely correlated with T(max) (r=0.954, P<0.0001) than with T(1/2b) (r=0.782, P=0.008). T(max) was significantly correlated with the percent gastric retention value in the early (t=0.25 and 0.5 h), the middle (t=1.0 and 1.5 h), and the late (t=2.0 h) postprandial phase. T(1/2b) was significantly correlated with the gastric retention value in the middle and the late phase, but not with the gastric retention value in the early phase. The present results show that T(1/2b) has limited capability to reflect gastric emptying in the early postprandial period, suggesting that T(max) is more reliable than T(1/2b) as a gastric emptying parameter.

Reliability of rapid urinary test for antibody to Helicobacter pylori in adult patients with proteinuria.

A urinary test for detecting the anti-H. pylori antibody using immunochromatography (RAPIRAN) is considered suitable for the screening purpose. However, this may yield spurious results in the presence of proteinuria. The present study was conducted to evaluate the diagnostic performance of RAPIRAN in patients with proteinuria. Urine and serum samples of adult inpatients with proteinuria were used for analyses. The diagnosis of H. pylori infection was made based on the seropositivity of anti-H. pylori antibody using 2 different serum tests. Fifty-one subjects were eligible for analyses. The serum tests showed negative and positive in 25 and 26 patients, respectively. Two of 25 seropositive patients had a negative result in RAPIRAN, and 1 provided invalid data. All of seronegative patients showed negative in RAPIRAN. The overall accuracy was 95.0%. The present study showed that RAPIRAN has diagnostic quality enough to use clinically also in patients with proteinuria.

Assessment of the gastric emptying velocity by the 13C-octanoate breath test: deconvolution versus a Wagner-Nelson analysis.

BACKGROUND: The dynamic change in gastric emptying on a minute-by-minute basis (gastric velocity) is evaluated by the 13C-octanoate breath test with deconvolution analysis. However, deconvolution is impractical, because it requires dual experiments to obtain 13CO2 excretion profiles following intraduodenal and oral administration of 13C-octanoate. We investigated whether the Wagner-Nelson method, used in drug absorption studies, can determine the velocity profile based on a single experiment as accurately as deconvolution, and whether the velocity assessed by the Wagner-Nelson method is sensitive enough to detect subtle changes in gastric emptying induced by butylscopolamine. METHODS: Five male volunteers underwent a 4-h breath test twice, after intraduodenal administration of 20 ml normal saline containing 100 mg 13C-octanoate and after ingestion of a 320-kcal muffin containing 100 mg 13C-octanoate. Deconvolution determined the velocity profile by subtracting duodenal from oral data, and the Wagner-Nelson method produced it from only oral data. The velocity profiles were compared between the two methods. Another six male subjects underwent the breath test by ingesting a muffin twice, once with and once without 20 mg oral butylscopolamine. The velocity profiles generated by the Wagner-Nelson analysis and the conventional 13CO2 excretion curves were compared between the two occasions. RESULTS: The two techniques yielded identical velocity profiles. The velocity profile detected a significant change in the emptying pattern induced by butylscopolamine (initial acceleration with subsequent deceleration), while the conventional breath curves failed to detect this change. CONCLUSIONS: Velocity assessment by a Wagner-Nelson analysis can precisely describe altered gastric emptying, based on a single experiment.

Effect of cigarette smoking on gastric emptying of solids in Japanese smokers: a crossover study using the 13C-octanoic acid breath test.

BACKGROUND: Cigarette smoking is associated with an increased risk of peptic ulcer and gastroesophageal reflux disease. Gastric emptying disorders may play a role in the development of these upper gastrointestinal diseases. Thus, studies examining a link between smoking and gastric emptying disorders have clinical relevance. This study was conducted to investigate the effect of smoking on gastric emptying of solids in Japanese smokers. METHODS: The (13)C-octanoic acid breath test was performed in eight male habitual smokers on two randomized occasions (either sham smoking or actively smoking). The time vs (13)CO(2) excretion rate curve was mathematically fitted to a conventional formula of y (t) = m*k*beta*e(-k*t)*(1 - e(-k*t))(beta-1), and the parameters of k and beta were determined: under the crossover protocol, a larger (smaller) beta indicates slower (faster) emptying in the early phase, and a larger (smaller) k indicates faster (slower) emptying in the later phase. The half (13)CO(2) excretion time (t(1/2b) = -[ln(1 - 2(-1/beta))]/k) and the time of maximal (13)CO(2) excretion rate (t(max) = [lnbeta]/k) were also calculated. Between the two occasions, k, beta, t(1/2b), and t(max) were compared by the Wilcoxon signed-rank test. RESULTS: After smoking, k was significantly increased. No significant differences were found in beta, t(1/2), and t(max) between the two occasions. CONCLUSIONS: The increase in k suggests the acceleration of gastric emptying in the later phase. For the first time, this study has revealed that acute smoking speeds the gastric emptying of solids in Japanese habitual smokers.

Reliability of urinary tests for antibody to Helicobacter pylori in patients with pulmonary tuberculosis.

AIM: Although the quality of currently available urinary tests for detecting antibody to Helicobacter pylori (H pylori) have been proved in some populations, the accuracy has not been studied regarding patients who suffer from pulmonary tuberculosis with multi-drug treatments. The present study was conducted to evaluate the accuracy of these urinary tests for antibody to H pylori in these patients. METHODS: Serum samples from 61 inpatients with pulmonary tuberculosis were tested using enzyme immunoassay, and urine samples were assayed by enzyme-linked immunosorbent assay method (URINELISA) and immunochromatography method (RAPIRAN). Medicines prescribed to the patients were recorded for medical charts, to evaluate the influences on the results of urinary tests. RESULTS: The sensitivity, specificity, and consistency of URINELISA against the serum test were 93.1%, 65.6%, and 78.6% respectively, and those of RAPIRAN were 86.2%, 93.7%, and 90.1% respectively, which were almost equal to the data previously reported. Prescribed medicines had little influence on the results. CONCLUSION: The two urinary tests for detecting H pylori antibody have a diagnostic accuracy in patients with pulmonary tuberculosis given multiple anti-tuberculosis drugs.

Gastric emptying of liquids is delayed by co-ingesting solids: a study using salivary paracetamol concentrations.

BACKGROUND: Paracetamol concentrations in plasma, a frequently used index of gastric emptying (GE) of liquids, are closely correlated with those in saliva. GE of liquids is delayed by co-ingesting solids. No researchers have used salivary paracetamol concentrations to show this phenomenon. The aim of this study was to elucidate whether salivary paracetamol concentrations can detect the food-induced delay in liquid GE. METHODS: Paracetamol absorption was measured twice in five healthy male volunteers. Following an overnight fast, they received 10 mg/kg paracetamol in 200 ml water alone on one occasion, and received this solution after consuming a 400 kcal-containing cookie on another occasion. After thorough rinsing of the month, 1 ml saliva was obtained, simultaneously with 2 ml blood, at 0, 0.25, 0.5, 0.75, 1.0, 2.0, 3.0, 4.0, and 6.0 h after paracetamol intake. The peak concentration (C(max)), the time to C(max) (t(max)), the area under the curve (AUC), and C(max)/AUC in plasma were calculated. Salivary C(max) and t(max) were also determined. RESULTS: Plasma C(max) and AUC were not significantly different between the two occasions. In contrast, significant differences in plasma t(max) and C(max)/AUC ( P < 0.05) established the food-induced delay in GE. Salivary t(max) could detect the delayed GE, whereas salivary C(max) could not. CONCLUSIONS: Salivary t(max) can document the solid meal-induced delay in liquid GE.

[The validity of serum acetaminophen concentration at 45 min as an index of gastric emptying rate: a study based on pharmacokinetic theories].

The reliability of the serum acetaminophen (APAP) concentration at 45 min (C45) as a measure of gastric emptying (GE) has been evaluated using a pharmacokinetic simulation work. The present results have revealed that C45 is a useful index to conveniently detect delayed GE, but it is unreliable to measure rapid GE. In addition, the following simple criteria for diagnosis of delayed GE has been proposed based on the pharmacokinetic theories: after ingestion of 20 mg/kg APAP dissolved in a 200 kcal-containing liquid meal, 1) the delayed GE is excluded when C45 > 5.0 micrograms/ml, 2) whether GE is delayed or not is inconclusive when 2.0 < C45 < 5.0 micrograms/ml, and 3) the delayed GE is confirmed when C45 < 2.0 micrograms/ml.

Right recumbent position on gastric emptying of water evidenced by (13)C breath testing.

AIM: To compare the impact of the right recumbent position with the sitting position on gastric emptying of water. METHODS: In eight healthy male volunteers, the 13C acetate breath test was performed twice to assess gastric emptying of 100 mL tap water. Subjects were seated in one test and lying on their right side in the other. In both positions, pulmonary (13)CO(2) exhalation curves were obtained by plotting breath data against time. Percent gastric retention curves were created by analyzing data using the Wagner-Nelson protocol. RESULTS: No significant posture effect was found in pulmonary (13)CO(2) output curves (P = 0.2150), whereas a significant effect was seen in gastric retention curves (P = 0.0315). The percent retention values at 10 min and 15 min were significantly smaller when subjects were in the right recumbent position compared with the seated position (P < 0.05). Our results verified the accelerating effect of the right recumbent position on gastric emptying of non-nutritive solutions. Concerning clinical implications, this study suggests that placing patients with acute pain on their right side after oral administration of analgesic drugs in solution is justified as an effective practice for rapid pain relief. For patients with gastrointestinal reflux symptoms, sleeping in the right recumbent position may reduce nocturnal symptoms, as delayed gastric emptying can cause reflux symptoms. CONCLUSION: Gastric emptying of water occurs more quickly when a subject lies on the right side compared with sitting.

Stable isotope breath tests for assessing gastric emptying: A comprehensive review.

A stable isotope ([(13)C]) breath test is a promising method for assessing gastric emptying, but it has not been pervasive yet in Japan. We think that there are some barriers to its popularization, including the uncertainty concerning its theoretical backgrounds, the ambiguity of analyzing and interpreting the data, and the lack of standard protocols for breath sampling. The aim of the present review is to break through these barriers. We hope this article could make the [(13)C]-gastric breath test more maneuverable for and more accessible to researchers and clinicians.

Endoscopic hemostasis techniques for upper gastrointestinal hemorrhage: A review.

Upper gastrointestinal hemorrhage (UGIH) is an urgent disease that is often encountered in daily medical practice. Endoscopic hemostasis is currently indispensable for the treatment of UGIH. Initially, when UGIH is suspected, a cause of UGIH is presumed from the medical interview and physical findings. After ample primary treatment, urgent endoscopy is performed. Many methods of endoscopic hemostasis are in wide use, including hemoclip, injection and thermo-coagulation methods. Although UGIH develops from a wide variety of diseases, such as esophageal varices and gastric and duodenal ulcer, hemostasis is almost always possible. Identification of the causative diseases, primary treatment and characteristic features of endoscopic hemostasis are needed to allow appropriate treatment.