No abstract

No abstract

To validate a 13C-Spirulina platensis breath test for measurement of accelerated or delayed gastric emptying, we measured gastric emptying of egg containing 13C-S. platensis and 99mTc-sulphur colloid by breath 13 CO2 every 15 min over 3 h and scintigraphy every 15-30 min over 5 h in 57 healthy volunteers. Thirty-three received no treatment, 10 received erythromycin, and 14 atropine. A generalized linear regression model predicted half-emptying time by scintigraphy (t1/2S) from breath 13CO2 (t1/2B) data. Accuracy was assessed by standard deviation (SD) of differences between t1/2S and t1/2B and by receiver operating characteristic (ROC) curves. Regression models using breath samples at baseline, and 45, 90, 105 and 120 min, predicted t1/2B (mean +/- SD) at 118 +/- 59 min, similar to t1/2S (118 +/- 67 min). Correlation between t1/2B and t1/2S was significant (r=0.88; P < 0.0001). Differences between t1/2S and t1/2B were: 18-19.2 min for t1/2 < 70-150 min, and 68.3 min for t1/2 > 150 min. Breath test detected abnormal emptying with a sensitivity of 86% and specificity of 80%. Thus, the 13C-S. platensis test measures gastric emptying t1/2 for solids, which is accelerated or delayed to mimic a range of conditions from dumping syndrome to severe gastroparesis, with high sensitivity and specificity. Additional breath samples are needed to increase sensitivity in detecting accelerated gastric emptying.

Three-dimensional single-photon emission computed tomography (SPECT) imaging allows noninvasive measurement of human postprandial gastric accommodation. The aim of this study was to determine whether 99mTCO4-SPECT demonstrates effects on pre- and postprandial gastric volumes of intravenous (i.v.) erythromycin lactobionate and sublingual isosorbide dinitrate, as predicted from previous literature. Twenty volunteers received no medication (controls), while 12 were randomized to either i.v. erythromycin 2 mg kg-1 over 20 min, or 10 mg sublingual isosorbide. After a 10-min preprandial SPECT measurement, a standard 300-mL, 300-kcal liquid meal was ingested, followed by a 20-min postprandial measurement. Gastric images were reconstructed from transaxial images and total volume was measured using the Analyseeth software system. Fasting gastric volume was greater with isosorbide [223 +/- 14 (SE) mL vs. 174 +/- 9 mL, control; P < 0.05], and postprandial volume was lower with erythromycin [393 +/- 27 mL vs. 582 +/- 17 mL, control; P < 0.05]. The ratio of postprandial over fasting volume and mean difference between pre- and postprandial volumes were significantly lower in both drug groups compared to controls. We conclude that 99mTCO4-SPECT imaging is able to semiquantitatively demonstrate pharmacological modulation of fasting gastric volume and postprandial accommodation in humans.