A comparison of the effect of loperamide in oral or suppository form vs placebo in patients with ileo-anal pouches.

OBJECTIVE: The effect of the anti-diarrhoeal drug, loperamide hydrochloride, on bowel function in patients with an ileo-anal pouch was studied by means of a blinded, three-tailed, case-controlled and randomized crossover trial, using a daily dose of 12 mg in either oral (4 mg t.d.s.) or suppository (6 mg b.d.) form. PATIENTS AND METHODS: Daily stool frequency was recorded in a diary and an objective measure of pouch motor function was obtained at the end of each treatment phase. Ten subjects (seven males, three females) aged 23-50 years (median 38 years) were studied 9-48 months (median 27 months) after ileostomy closure. Eight pouches had been constructed for ulcerative colitis and two for familial adenomatous polyposis (9J, 1W). RESULTS: Mean daily stool frequency during the oral loperamide phase was lower than during both the placebo (P=0.05) and suppository (P < 0.02) phases. Stool frequency did not differ significantly between placebo and suppository phases. There was a strong inverse correlation between mean daily stool frequency and pouch capacity (r=-0.82 after both oral and suppository phases). Large isolated pouch contractions were evident in five of eight subjects studied; suppression was observed in two of the five after oral loperamide and in three of the five after loperamide suppositories. Rhythmic pouch contractions were seen in four subjects and suppression was evident after loperamide suppositories (but not after oral loperamide) in three. A daily oral dose of 12 mg loperamide significantly lowered stool frequency in pouch patients and modified some aspects of pouch contraction. Loperamide suppositories produced more prominent suppression of pouch contractions but did not lower stool frequency. CONCLUSION: This suggests that the beneficial effect of oral loperamide is primarily due to its action on intestine proximal to the pouch itself.

Spontaneous transpyloric migration of a ballooned nasojejunal tube: a randomized controlled trial.

BACKGROUND: Spontaneous transpyloric migration of a simple nasojejunal tube (NJT) can be expected in only one-third of insertions. Guidance of the tube by radiologic or endoscopic maneuvers is usually required. We believed that locating a 5-mL balloon near the tip of an NJT on which natural peristalsis could act would improve the rate of spontaneous transpyloric migration and facilitate small bowel propagation. METHODS: Thirty healthy volunteers were randomly assigned to have an inflated or noninflated, ballooned NJT fashioned from a modified 9F Hickman line catheter inserted. The pH of aspirates was measured hourly and the final location of the tube assessed by gastrografin contrast abdominal x-ray (AXR) at the end of 6 hours, at which time the tube was removed. RESULTS: After 6 hours, spontaneous transpyloric migration occurred in 86.6% of the ballooned and 66.6% of the nonballooned tubes. The final disposition of the ballooned tubes was: stomach, 2 (13.3%); duodenum, 1 (6.7%); and small bowel, 12 (80%). The final disposition of the nonballooned tubes was: stomach, 5 (33%), NS; duodenum, 9 (60%), p < .05; and small bowel, 1 (6.7%), p < .05. CONCLUSIONS: Ballooned NJT have a higher rate of spontaneous transpyloric migration and are significantly more likely to achieve an optimal small bowel location.

A comparison of J and W pouches using an isolated ileal reservoir in pigs.

A new model for studying ileal reservoirs was used to compare J and W pouches. Sixteen female piglets were operated on between 62 and 67 days of age (median = 65). An approximately 50 cm vascularized segment of terminal ileum was isolated from the faecal stream and intestinal continuity restored. The distal 40 cm of the isolated loop was opened along its antimesenteric border and the pouch constructed (J = 8, W = 8). The remaining proximal length of ileum was brought out through the abdominal wall as a mucous fistula. One piglet in the W pouch group died post-operatively and in another, spontaneous closure of the mucous fistula prevented access to the W pouch for testing leaving six W and eight J pouches for comparison. Compliance was tested at 4 weeks by measuring intrapouch pressure during continuous distension by water. The volumes instilled at pressures of 20, 40, 60 and 80 cm of water were compared using the Mann-Whitney U-Test. Volumes varied widely at all pressures within both study groups although W pouches tended to be of larger volume for any given pouch pressure (P = NS). The failure of this study to demonstrate more clearly a difference between J and W pouches may be due to the small numbers involved but the wide range of volumes seen raises doubts about the usefulness of this pouch model.

Scattering of linearly polarized microwave radiation from a dielectric target including the interaction between target elements.

The theory for finding the internal field within a dielectric helix when the radiation has a wavelength larger than the diameter of the helical wire is presented. Intensities are calculated and compared to an experiment and to the theoretical results of an earlier paper that does not include the self-interaction effect. The internal field is defined in terms of a polarization matrix that is assumed to be constant across any cross section of the helix. It is found that target self-iteractions have a significant effect on the internal field. It is also noted that this effect for the far field intensities, although significant and generally a better fit to the data, is not profoundly different. That is, the effects of a more appropriately constructed internal field are less important than the geometry effect in the far field.

Scattering of linearly polarized microwave radiation from a dielectric helix.

A method for calculating the electric field scattered from a helical dielectric target is compared to an equivalent experiment. The wavelength of the incident light is 3.18 cm, and the right-handed helix has a radius of 1.83 cm and wire radius of 0.24 cm, a pitch of 0.553 cm, and seven turns. The index of refraction of, the target is 1.626-i 0.012. A brief description of the Shifrin theory generalized to this application is given along with a discussion of the experiment, and the experimental intensities are compared to the first-order theory.