Gastric transit and small intestinal transit time and motility assessed by a magnet tracking system

Abstract

BackgroundTracking an ingested magnet by the Magnet Tracking System MTS-1 (Motilis, Lausanne, Switzerland) is an easy and minimally-invasive method to assess gastrointestinal transit. The aim was to test the validity of MTS-1 for assessment of gastric transit time and small intestinal transit time, and to illustrate transit patterns detected by the system.MethodsA small magnet was ingested and tracked by an external matrix of 16 magnetic field sensors (4 × 4) giving a position defined by 5 coordinates (position: x, y, z, and angle: θ, ϕ). Eight healthy subjects were each investigated three times: (1) with a small magnet mounted on a capsule endoscope (PillCam); (2) with the magnet alone and the small intestine in the fasting state; and (3) with the magnet alone and the small intestine in the postprandial state.ResultsExperiment (1) showed good agreement and no systematic differences between MTS-1 and capsule endoscopy when assessing gastric transit (median difference 1 min; range: 0-6 min) and small intestinal transit time (median difference 0.5 min; range: 0-52 min). Comparing experiments (1) and (2) there were no systematic differences in gastric transit or small intestinal transit when using the magnet-PillCam unit and the much smaller magnetic pill. In experiments (2) and (3), short bursts of very fast movements lasting less than 5% of the time accounted for more than half the distance covered during the first two hours in the small intestine, irrespective of whether the small intestine was in the fasting or postprandial state. The mean contraction frequency in the small intestine was significantly lower in the fasting state than in the postprandial state (9.90 min-1 vs. 10.53 min-1) (p = 0.03).ConclusionMTS-1 is reliable for determination of gastric transit and small intestinal transit time. It is possible to distinguish between the mean contraction frequency of small intestine in the fasting state and in the postprandial state.

The Impact of Opioid Treatment on Regional Gastrointestinal Transit

“…Inter-observer agreement was not done, as it previously has been shown to be good for both an earlier version of the 3D-Transit system 18 and the same version as used in the present study. 20 All segmental colonic transit times were determined by the same investigator (T.H.S.).…”

“…Based on previously validated principles, regional transit times were determined in the 3D-Transit analysis software from changes in contraction frequencies observed on the capsule rotation graphs, the time-frequency map for the recording, and 2D overview of capsule position. 18 Gastric emptying was defined as the time from ingestion until pyloric passage, the latter identified as a shift from approximately 3 contractions per minute (cpm) to 12 cpm, in combination with the characteristic 2D image of passage through the duodenal arch. As the ingestion time for the first dose of oxycodone and ingestion time of the 3D-Transit capsule was only 15 minutes apart, gastric emptying was not analysed in this study, as the short time interval did not allow for oxycodone to be sufficiently absorbed and induce OIBD in the gastric segment.…”

“…This is a recently introduced, minimally-invasive, ambulatory system which--using a body-borne detection matrix--simultaneously tracks the precise position and general orientation of an electromagnetic capsule from ingestion to expulsion. [16][17][18][19] Hence, the pan-enteric impact of opioid treatment can be accurately assessed, providing new insight into altered motility patterns. 20 However, opioid treated patients often suffer from comorbidities and concomitant drug use, which complicates evaluation of the underlying pathophysiological mechanisms.…”

Acute exposure to organic and inorganic sources of copper: Differential response in intestinal cell lines

“…In this study, two colon cancer cell lines, Caco‐2 and HT29, were selected (because of their similarity to normal intestinal enterocyte and goblet cells) to examine ROS production on exposure to inorganic CuSO 4 and organic nutrient sources of copper (Cu Gly, Cu OAC, and Cu pro) and their global proteomic impact. Employing a two‐hour exposure to reflect the average intestinal transit (Worsøe et al., 2011), a concentration of copper which caused a small but significant impact on cell viability was chosen. For the four coppers, the average concentrations were 400 μM and 500 μM for Caco‐2 and HT29, respectively, which caused a 30% reduction in cell growth.…”

“…To investigate the effect of copper sources, a slightly toxic concentration of IC20 (to reduce viable cell counts by 20%) over a 2‐hr exposure (to reflect the transit in the small intestine, Worsøe et al., 2011) and 10‐hr recovery was chosen. An average IC20 value of 0.4 and 0.5 mM copper source, respectively, for Caco‐2 and HT29 was measured by viable cell counts with trypan blue following the 10‐hr recovery.…”