Polymer conjugates for imaging.
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Contrast Media↗
Biomedical subjects
Alan C Perkins
Publications and source records attributed to Alan C Perkins.
Effect of salt and water balance on recovery of gastrointestinal function after elective colonic resection: a randomised controlled trial.
BACKGROUND: Low concentrations of albumin in serum and long gastric emptying times have been returned to normal in dogs by salt and water restriction, or a high protein intake. We aimed to determine the effect of salt and water balance on recovery of gastrointestinal function after elective colonic resection in human beings. METHODS: We randomly allocated ten patients to receive postoperative intravenous fluids in accordance present hospital practice (> or = 3 L water and 154 mmol sodium per day) and ten to receive a restricted intake (< or = 2 L water and 77 mmol sodium per day). All patients had no disease other than colonic cancer. The primary endpoint was solid and liquid-phase gastric emptying time, measured by dual isotope radionuclide scintigraphy on the fourth postoperative day. Secondary endpoints included time to first bowel movement and length of postoperative hospital stay. Analysis was by intention to treat. FINDINGS: Median solid and liquid phase gastric emptying times (T(50)) on the fourth postoperative day were significantly longer in the standard group than in the restricted group (175 vs 72.5 min, difference 56 [95% CI 12-132], p=0.028; and 110 vs 73.5 min, 52 [9-95], p=0.017, respectively). Median passage of flatus was 1 day later (4 vs 3 days, 2 [1-2], p=0.001); median passage of stool 2.5 days later (6.5 vs 4 days, 3 [2-4], p=0.001); and median postoperative hospital stay 3 days longer (9 vs 6 days, 3 [1-8], p=0.001) in the standard group than in the restricted group. One patient in the restricted group developed hypokalaemia, whereas seven patients in the standard group had side-effects or complications (p=0.01). INTERPRETATION: Positive salt and water balance sufficient to cause a 3 kg weight gain after surgery delays return of gastrointestinal function and prolongs hospital stay in patients undergoing elective colonic resection.
Aged↗
Evaluation of Pulsincap to provide regional delivery of dofetilide to the human GI tract.
Pulsincap formulations designed to deliver a dose of drug following a 5-h delay were prepared to evaluate the capability of the formulation to deliver dofetilide to the lower gastrointestinal (GI) tract. By the expected 5-h release time, the preparations were well dispersed throughout the GI tract, from stomach to colon. Plasma analysis permitted drug absorption to be determined as a function of GI tract site of release. Dofetilide is a well-absorbed drug, but showed a reduction in observed bioavailability when delivered from the Pulsincap formulations, particularly at more distal GI tract sites. Dispersion of the drug from the soluble excipient used in this prototype formulation relies on a passive diffusion mechanism and the relevance of this factor to the reduced extent and consistency of absorption from the colon is discussed. In these studies the effects of the degree of dispersion versus the site of dispersion could not be ascertained; nevertheless the scintigraphic analysis demonstrated good in vitro-in vivo correlation for time of release from Pulsincap preparations. The combination of scintigraphic and pharmacokinetic analysis permits identification of the site of drug release from the dosage form and pharmacokinetic parameters to be studied in man in a non-invasive manner.
Anti-Arrhythmia Agents↗
Abnormalities of GI transit in bloated irritable bowel syndrome: effect of bran on transit and symptoms.
OBJECTIVES: Bloating is an important but poorly understood symptom in irritable bowel syndrome (IBS) that is often aggravated by bran. The aim of our study was to determine whether IBS patients with bloating responded to bran differently from healthy controls. METHODS: A total of 12 patients with IBS (according to Rome I criteria), all with moderate to severe bloating, and 12 healthy controls participated in a two way, double blind, randomized, cross-over trial of bran versus placebo (crushed biscuits) 15 g b.i.d. An average daily pain index and bloating score were derived from daily symptom diaries. On day 14, gastric emptying, small bowel transit, percent remaining in ascending colon, and geometric center of a meal marker at 24 h were calculated from scintigraphic images obtained after ingesting a Tc99m-labeled rice pudding meal with 15 g of either placebo or coarse bran. RESULTS: Results are given as median (range). Bran significantly increased the pain index and bloating (p < 0.02) in IBS patients but not controls. The most striking finding was that the small bowel transit time of the meal without bran was markedly faster in IBS patients than in controls, being 203 min (range 109-313) versus 367 min (219-543), p < 0.001. Although in controls bran accelerated small bowel transit time to 262 min (180-380), p = 0.03, and significantly reduced % remaining in the ascending colon from 22% (0-46) to 3% (0-25), p = 0.03, this was not seen in the IBS patients. Bran accelerated whole gut transit as assessed by geometric center at 24 h in both IBS patients and controls. CONCLUSIONS: Bran accelerates small bowel transit and ascending colon clearance without causing symptoms in controls. Small bowel transit is rapid in IBS patients with bloating and, unlike in healthy control subjects, cannot be further accelerated by bran, which nevertheless aggravates symptoms of pain and bloating. We speculate that bran-induced bloating may originate in the colon rather than the small bowel.
Adult↗