Zarate N.,Queen Mary, University of London |
Mohammed S.D.,Queen Mary, University of London |
O'Shaughnessy E.,Royal London Hospital |
Newell M.,Royal London Hospital |
And 5 more authors.
American Journal of Physiology - Gastrointestinal and Liver Physiology | Year: 2010
Stereotypical changes in pH occur along the gastrointestinal (GI) tract. Classically, there is an abrupt increase in pH on exit from the stomach, followed later by a sharp fall in pH, attributed to passage through the ileocecal region. However, the precise location of this latter pH change has never been conclusively substantiated. We aimed to determine the site of fall in pH using a dual-scintigraphic technique. On day 1, 13 healthy subjects underwent nasal intubation with a 3-m-long catheter, which was allowed to progress to the distal ileum. On day 2, subjects ingested a pH-sensitive wireless motility capsule labeled with 4 MBq 51Chromium [EDTA]. The course of this, as it travelled through the GI tract, was assessed with a single-headed γ-camera using static and dynamic scans. Capsule progression was plotted relative to a background of 4 MBq 111Indium [diethylenetriamine penta-acetic acid] administered through the catheter. Intraluminal pH, as recorded by the capsule, was monitored continuously, and position of the capsule relative to pH was established. A sharp fall in pH was recorded in all subjects; position of the capsule relative to this was accurately determined anatomically in 9/13 subjects. In these nine subjects, a pH drop of 1.5 ± 0.2 U, from 7.6 ± 0.05 to 6.1 ± 0.1 occurred a median of 7.5 min (1-16) after passage through the ileocecal valve; location was either in the cecum (n = 5), ascending colon (n = 2), or coincident with a move from the cecum to ascending colon (n = 2). This study provides conclusive evidence that the fall in pH seen within the ileocolonic region actually occurs in the proximal colon. This phenomenon can be used as a biomarker of transition between the small and large bowel and validates assessment of regional GI motility using capsule technology that incorporates pH measurement. Copyright © 2010 the American Physiological Society.
Gelfond D.,Children's Hospital of Buffalo |
Ma C.,State University of New York at Buffalo |
Semler J.,SmartPill |
Borowitz D.,State University of New York at Buffalo
Digestive Diseases and Sciences | Year: 2013
Background and Aims: The effect of the cystic fibrosis transmembrane conductance regulator protein (CFTR) defect in pancreatic insufficient (PI) patients with cystic fibrosis (CF) on the gastrointestinal pH profile is poorly defined. Adequate and efficient neutralization of the gastric acidity in the duodenum is important for nutrient absorption and timely release of pancreatic enzyme replacement therapy (PERT). We utilized a wireless motility capsule (WMC) to study intestinal pH profile and gastrointestinal transit profile in CF subjects. Methods: WMC studies were done on ten adult CF patients with PI while off acid suppression medication and ten age, gender and BMI matched healthy controls. Mean pH over 1 min increments and area under the pH curve over 5 min increments was calculated for the first hour post gastric emptying. Paired t-test was used to compare means of the pH recordings, transit profiles and analysis of time interval required to reach and maintain pH >5.5 and 6.0. Results: A statistically significant difference was observed between mean pH values during the first 23 min of small bowel transit (p < 0.05). In CF subjects, there was a significant delay in time interval required to reach and sustain pH 5.5 and pH 6.0 (p < 0.001), which is required for PERT dissolution. Only small bowel transit in CF subjects was noted to be significantly delayed (p = 0.004) without a compensatory increase in whole gut transit time. Conclusions: We have demonstrated a significant delay in the small intestinal transit and a deficient buffering capacity required to neutralize gastric acid in the proximal small bowel of patients with CF. © 2012 Springer Science+Business Media, LLC.
Rozov-Ung I.,State University of New York at Buffalo |
Mreyoud A.,State University of New York at Buffalo |
Moore J.,State University of New York at Buffalo |
Wilding G.E.,State University of New York at Buffalo |
And 4 more authors.
BMC Gastroenterology | Year: 2014
Background: A wireless motility capsule is a new method for ambulatory assessment of transit times and motility throughout the gastrointestinal tract. The objective of this study was to evaluate the ability of a wireless motility capsule to detect drug effects on gastric emptying time (GET) and gastric contractility.Methods: 15 healthy adults were administered in random order saline, erythromycin IV 150 mg, or morphine IV 0.05 mg/kg BW. Subjects ate a standard meal after each infusion, and subsequently ingested the motility capsule. Data were recorded for 8 hours, and the results were analyzed using the manufacturer's software.Results: GET was significantly faster after erythromycin than either saline or morphine. Morphine tended to delay emptying of the capsule compared to saline. There was a trend toward a greater frequency of gastric contractions with erythromycin and a reduced frequency of gastric contractions with morphine that did not reach statistical significance.Conclusions: A wireless motility capsule successfully detected acceleration of gastric emptying induced by erythromycin, and retardation of gastric motility caused by morphine. These results indicate that a wireless motility capsule is a promising technique to assess pharmacologic effects on gastric transit and contractility and aid in development of drugs for gastric motor disorders. © 2014 Rozov-Ung et al.; licensee BioMed Central Ltd.
Saad R.J.,University of Michigan |
Rao S.S.C.,University of Iowa |
Koch K.L.,Wake forest University |
Kuo B.,Massachusetts General Hospital |
And 6 more authors.
American Journal of Gastroenterology | Year: 2010
Objectives: Despite a lack of supportive data, stool form and stool frequency are often used as clinical surrogates for gut transit in constipated patients. The aim of this study was to assess the correlation between stool characteristics (form and frequency) and gut transit in constipated and healthy adults. Methods: A post hoc analysis was performed on 110 subjects (46 chronic constipation) from nine US sites recording stool form (Bristol Stool Scale) and frequency during simultaneous assessment of whole-gut and colonic transit by wireless motility capsule (WMC) and radio-opaque marker (ROM) tests. Stool form and frequency were correlated with transit times using Spearman's rank correlation. Accuracy of stool form in predicting delayed transit was assessed by receiver operating characteristic analysis. Results: In the constipated adults (42 females, 4 males), moderate correlations were found between stool form and whole-gut transit measured by WMC (r0.61, P0.0001) or ROM (0.45, P0.0016), as well as colonic transit measured by WMC (0.62, P0.0001). A Bristol stool form value 3 predicted delayed whole-gut transit with a sensitivity of 85% and specificity of 82% and delayed colonic transit with a sensitivity of 82% and specificity of 83%. No correlation between stool form and measured transit was found in healthy adults, regardless of gender. No correlation was found between stool frequency and measured transit in constipated or healthy adults. The correlation between stool frequency and measured transit remained poor in constipated adults with 3 bowel movements per week. Conclusions: Stool form predicts delayed vs. normal transit in adults. However, only a moderate correlation exists between stool form and measured whole-gut or colonic transit time in constipated adults. In contrast, stool frequency is a poor surrogate for transit, even in those with reduced stool frequency. © 2010 by the American College of Gastroenterology.
Camilleri M.,Rochester College |
Thorne N.K.,Wake forest University |
Ringel Y.,University of North Carolina at Chapel Hill |
Hasler W.L.,University of Michigan |
And 10 more authors.
Neurogastroenterology and Motility | Year: 2010
Background Colon transit (CT) measurements are used in the management of significant constipation. The radiopaque marker (ROM) method provides limited information. Methods We proposed to validate wireless motility capsule (WMC), that measures pH, pressure and temperature, to ROM measurement of CT in patients with symptomatic constipation evaluated at multiple centers. Of 208 patients recruited, 158 eligible patients underwent simultaneous measurement of colonic transit time (CTT) using ROM (Metcalf method, cut off for delay >67 h), and WMC (cutoff for delay >59 h). The study was designed to demonstrate substantial equivalence, defined as diagnostic agreement >65% for patients who had normal or delayed ROM transit. Key Results Fifty-nine of 157 patients had delayed ROM CT. Transit results by the two methods differed: ROM median 55.0 h [IQR 31.0-85.0] and WMC (43.5 h [21.7-70.3], P < 0.001. The positive percent agreement between WMC and ROM for delayed transit was ∼80%; positive agreement in 47 by WMC/59 by ROM or 0.796 (95% CI = 0.67-0.98); agreement vs null hypothesis (65%) P = 0.01. The negative percent agreement (normal transit) was ∼91%: 89 by WMC/98 by ROM or 0.908 (95% CI = 0.83-0.96); agreement vs null hypothesis (65%), P = 0.00001. Overall device agreement was 87%. There were significant correlations (P < 0.001) between ROM and WMC transit (CTT [r = 0.707] and between ROM and combined small and large bowel transit [r = 0.704]). There were no significant adverse events. Conclusions & Inferences The 87% overall agreement (positive and negative) validates WMC relative to ROM in differentiating slow vs normal CT in a multicenter clinical study of constipation. © 2010 Blackwell Publishing Ltd.
Sarosiek I.,Texas Tech University |
Sarosiek I.,University of Kansas Medical Center |
Selover K.H.,SmartPill |
Katz L.A.,State University of New York at Buffalo |
And 11 more authors.
Alimentary Pharmacology and Therapeutics | Year: 2010
Background Wireless pH and pressure motility capsule (wireless motility capsule) technology provides a method to assess regional gastrointestinal transit times. Aims To analyse data from a multi-centre study of gastroparetic patients and healthy controls and to compare regional transit times measured by wireless motility capsule in healthy controls and gastroparetics (GP). Methods A total of 66 healthy controls and 34 patients with GP (15 diabetic and 19 idiopathic) swallowed wireless motility capsule together with standardized meal (255 kcal). Gastric emptying time (GET), small bowel transit time (SBTT), colon transit time (CTT) and whole gut transit time (WGTT) were calculated using the wireless motility capsule. Results Gastric emptying time, CTT and WGTT but not SBTT were significantly longer in GP than in controls. Eighteen percent of gastroparetic patients had delayed WGTT. Both diabetic and idiopathic aetiologies of gastroparetics had significantly slower WGTT (P < 0.0001) in addition to significantly slower GET than healthy controls. Diabetic gastroparetics additionally had significantly slower CTT than healthy controls (P = 0.0054). Conclusions In addition to assessing gastric emptying, regional transit times can be measured using wireless motility capsule. The prolongation of CTT in gastroparetic patients indicates that dysmotility beyond the stomach in GP is present, and it could be contributing to symptom presentation.
Brun R.,Massachusetts General Hospital |
Michalek W.,Massachusetts General Hospital |
Surjanhata B.C.,Massachusetts General Hospital |
Parkman H.P.,Temple University |
And 2 more authors.
Neurogastroenterology and Motility | Year: 2012
Background Assessment of phase III MMC is often not performed due to the invasive nature of antroduodenal manometry used to detect it. The aim of the study was to evaluate the ability of wireless motility capsule (WMC) to detect phase III MMC and correlate it with the simultaneous measurements by antroduodenal manometry (ADM). Methods Eighteen patients underwent simultaneous ADM and WMC. MMCs were identified first on ADM and then correlated with WMC events occurring simultaneously. Frequency of contractions per min, AUC, MI, and criteria for amplitude thresholds of contractions representing MCCs on WMC tracings were defined. Key Results In 18 patients, a total of 29 MMCs were recorded by ADM. WMC detected 86% of MMC events measured by ADM. Hundred percent (10/10) of MMCs in stomach were detected by WMC, whereas 79% (15/19) of MMCs were detected in SB. The sensitivity and specificity of WMC high amplitude contractions to represent phase III MMC were 90% and 71.8% in the stomach; 73.7% and 84.7% in SB, respectively, and negative predictive value was 99.9% in both regions. Conclusions & Inferences Wireless motility capsule was able to detect the phase III MMCs as the high amplitude contractions with good fidelity. WMC does not detect the propagation of MMC. Using the pressure thresholds, WMC can detect high amplitude contraction representing phase III MMC with favorable sensitivity/specificity profile and 99.9% negative predictive value. This observation may have clinical significance, as the absence of high amplitude contractions recorded by WMC during fasting state suggests absence of MMCs. © 2012 Blackwell Publishing Ltd.
Michalek W.,Massachusetts General Hospital |
Semler J.R.,SmartPill |
Kuo B.,Massachusetts General Hospital
Digestive Diseases and Sciences | Year: 2011
Background: Proton pump inhibitors (PPIs), widely prescribed to patients with upper gastrointestinal symptoms, alter intragastric pH, and may affect upper gastrointestinal transit and motility parameters in addition to affecting the ability to determine Wireless Motility Capsule (WMC) gastric emptying time. Aim: To assess PPI effect on motility parameters of the upper gastrointestinal tract and to determine if PPIs confound ability of WMC to measure gastric emptying time. Methods: Twenty healthy subjects were treated with esomeprazole 40 mg bid for 1 week. Another 50 healthy subjects underwent evaluation in absence of PPIs. All subjects underwent WMC test after meal ingestion. After a rapid, sustained luminal pH rise ≥ 0.5 pH units, marking potential gastric emptying time of WMC, an abdominal X-ray (KUB) was taken for gastric emptying time confirmation. Mean pH, pressure and transit time were compared between PPI-treated and untreated groups. Results: There was no difference in gastric emptying time, small bowel transit time (SBTT), or pressure profiles between the groups. The pH in all cases rose ≥ 0.5 pH units. Distal small bowel pH was significantly lower in subjects on PPIs. Gastric emptying time was identified in all subjects treated with PPIs. Pressure and slope criteria were developed to confirm the time of emptying. Conclusion: PPI therapy does not have a significant impact on upper gastrointestinal transit and motility but it does decrease distal small bowel pH. The medication reduced the magnitude of pH change at gastric emptying time but using additional criteria based on slope and contraction frequency, WMC was able to measure gastric emptying time in all patients treated with PPIs. © 2010 Springer Science+Business Media, LLC.
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