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8. An Overview

Author

Gladman, Marc A., Scott, S. Mark, Williams, Norman S., Wexner, Steven D., Zbar, Andrew P., and Pescatori, Mario

Published
2005
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13. Accurate localization of a fall in pH within the ileocecal region: validation using a dual-scintigraphic technique

Author

Zarate, Natalia, Mohammed, Sahar D., O'Shaughnessy, Emma, Newell, Margaret, Yazaki, Etsuro, Williams, Norman S., Lunniss, Peter J., Semler, Jack R., and Scott, S. Mark

Subjects
Telemetry -- Methods, Telemetry -- Equipment and supplies, Mesentery -- Properties, Arteries -- Properties, Hydrogen-ion concentration -- Measurement, Hydrogen-ion concentration -- Methods, Biological sciences
Abstract

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 [sup.51]Chromium [EDTA]. The course of this, as it travelled through the GI tract, was assessed with a single-headed [gamma]-camera using static and dynamic scans. Capsule progression was plotted relative to a background of 4 MBq [sup.111]Indium [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 [+ or -] 0.2 U, from 7.6 [+ or -] 0.05 to 6.1 [+ or -] 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. pH profile; wireless (telemetric) capsule doi: 10.1152/ajpgi.00127.2010.

Published
2010

27. Standards for anal sphincter replacement

Author

Madoff, Robert D., Baeten, Cornelius G. M. I., Christiansen, John, Rosen, Harald R., Williams, Norman S., Heine, John A., Lehur, Paul A., Lowry, Ann C., Lubowski, David Z., Matzel, Klaus E., Nicholls, R. J., Seccia, Massimo, Thorson, Alan G., Wexner, Steven D., and Wong, W. Douglas

Published
2000
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39. Prolonged ambulatory canine colonic motility

Author

Scott, S. Mark, Pilot, Marie-Anne, Barnett, Tony G., and Williams, Norman S.

Subjects
Surgery, Outpatient -- Analysis, Irritable bowel syndrome -- Analysis, Colon (Anatomy) -- Analysis, Biological sciences
Abstract

The ambulatory model is a useful method for studying canine gastrointestinal motility as it gives a more comprehensive picture than the laboratory experiments. It records colonic activity in dogs over a period of twenty-four hours. Portable battery-operated amplifier and digital recorder process and store motility signals from implanted strain gauges. Four different phases modulated by feeding time and defecation process characterize postprandial colonic motility.

Published
1995

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