John W. Hamilton

Sleeping on a wedge diminishes exposure of the esophagus to refluxed acid

In a randomized crossover study, we compared the effect on gastroesophageal reflux of three sleeping positions: elevation of the head of the bed on standard eight-inch bed blocks; elevation by a foam wedge; or a flat position. Fifteen subjects with moderate to severe reflux symptoms were studied in each position on consecutive nights using continuous intraesophageal pH monitoring. We found no difference in reflux frequency among the positions. The wedge caused a statistically significant decrease in the time that distal esophageal pH was less than 4 as compared to the flat position. The wedge also decreased the longest episode experienced by the subjects. Elevation on blocks caused a similar improvement in parameters but failed in this study to achieve statistical significance. Both elevation by a wedge and on blocks showed a trend towards a decrease in clearance time as compared to the flat position. The patients did not always prefer elevation on a wedge, but for some it is a valuable alternative to elevation by bed blocks.

Clinical evaluation of methylcellulose as a bulk laxative

We studied a bulk laxative containing methylcellulose in a group of normal subjects as well as in a group of chronically constipated individuals. The initial study in normal subjects was performed to show that the compound could increase fecal weight without significant side effects. Fifty healthy subjects were studied. Methylcellulose in daily doses of 4 g demonstrated a statistically significant increase in fecal frequency, fecal water, and fecal solids. In the second phase, we studied a group of 59 chronically constipated individuals treated with daily doses of the laxative containing either 1, 2, or 4 g of methylcellulose or 3.4 g psyllium. All of these doses resulted in statistically significant increases in stool frequency, water content, and fecal solids. There was no increase in individual stool weight from any of the laxative doses. Methylcellulose, in a daily dose as low as 1 g, is an effective laxative.

Carnitine transport in human intestinal biopsy specimens. Demonstration of an active transport system.

Although carnitine is present in a variety of foods, the mechanism of its absorption has not been previously studied in humans. We investigated the absorption of carnitine by studying uptake into human intestinal mucosal biopsy specimens. We found evidence of active transport in the duodenum and ileum, but not in the colon. We demonstrated that intracellular concentrations exceeded concentrations in the incubation media at steady states and that uptake against a concentration gradient was abolished by anoxia and by replacement of sodium ion with potassium. Studies of initial rate of uptake over a range of concentrations revealed a curve consistent with a two-component system: a saturable system with a KT of 558 microM and a linear component probably representing passive diffusion. Addition of D-carnitine and L-acetylcarnitine resulted in diminished uptake of L-carnitine, suggesting that these substrates utilize the same transport mechanism. These studies demonstrate the presence of an active intestinal transport system for L-carnitine in human intestinal mucosa.

An Improved Method for Recording and Analyzing the Electrical Activity of the Human Stomach

We have simultaneously recorded the transcutaneous and gastric electrogastrogram in 26 humans. The gastric suction electrode had 3 sintered Ag/AgCl electrodes which minimized motion artifacts. These were cast into a silicone rubber cup. For the transcutaneous signals, we punctured the skin under sintered Ag/AgCl transcutaneous electrodes to minimize variations in skin potential. We located the gastric electrode by fluoroscopy in the antrum and located the transcutaneous electrode over it to optimize the signal-to-noise ratio. A gastric pressure balloon confirmed that large electrical waves were synchronous with gastric contractions. We successfully recorded the electrogastrogram in 23 of 26 normal subjects. A fast Fourier transform produced a similar power spectrum for transcutaneous and gastric recordings. The cross-correlation function between the transcutaneous recording and the gastric recording confirms that the signals are of the same origin. This noninvasive transcutaneous technique is very attractive to investigate patients with suspected gastric disturbances.

Isolated cytomegalovirus ileitis detected by colonoscopy

Cytomegalovirus infections in immunocompromised patients mimic graft-versus-host disease by causing abdominal pain, watery diarrhea, and protein-losing enteropathy. The cases of three bone marrow transplant patients with diarrheal illness and biopsy-proven graft-vs.-host disease are reported. Isolated cytomegalovirus enteritis was subsequently identified by endoscopic examination and biopsy of the terminal ileum. All three improved with the eventual institution of 9-(1,3-dihydroxy-2-propoxymethyl) guanine. Ileoscopy is important in addition to colonoscopy in bone marrow transplant patients with diarrhea if cytomegalovirus enteritis is to be identified and appropriately treated.

Management of chronic ulcerative colitis and rectovaginal fistula by simultaneous ileal pouch construction and fistula closure: report of a case

Persistent rectovaginal fistulas occurring with ulcerative colitis are unusual manifestations that complicate surgical or medical treatment of the primary disease. Prior to the development of ileal pouch proceduress many cases were traditionally managed with a total colectomy and permanent ileostomy. The authors are aware of no previous study using concurrent fistula repair combined with ileal pouch construction to manage this complex problem. The successful simultaneous repair of a chronic rectovaginal fistula with ileal pouch reconstruction in a patient with intractable ulcerative colitis is reported.

The use of the diving reflex to terminate supraventricular tachycardia in a 2-week-old infant.

The use of the diving reflex to terminate a case of paroxysmal supraventricular tachycardia (PST) is described in a 2-week-old infant who presented in severe congestive heart failure with supraventricular tachycardia at a rate of 300. The infants face was placed in a basin of ice water at 5 degrees C. for 5 seconds with manual occlusion of the infants nostrils to prevent aspiration. The PST converted to a sinus rhythm of 120 within 3 seconds of facial immersion. The physiology of the diving reflex is reviewed and the uses and hazards of this reflex in terminating attacks of PST in infants is discussed.