An angiomatous nasal polyp: a very rare variant of sinochoanal nasal polyps.

Angiomatous polyps are the extremely rare variant of sinochoanal polyps that are characterised by dilated, large vascular spaces. A 27-year-old female patient presented with a three-month history of unilateral right-sided nasal obstruction and recurrent mild epistaxis. Paranasal computed tomography demonstrated a mass in the right maxillary sinus extending through the nasal cavity. It was resected with both endonasal endoscopic and Caldwell-Luc approaches. Histopathological examination identified an angiomatous nasal polyp. Follow-up of thirteen months showed no recurrence.

Ameloblastic carcinoma containing melanocyte and melanin pigment in the mandible: a case report and review of the literature.

A case of ameloblastic carcinoma containing melanocyte and melanin in a 66-year-old male with swelling and an ulcerating firm mass in the left submandibular region is presented. The diagnosis was confirmed by biopsy. The current histopathological diagnosis and management are discussed.

Role of lipase in the regulation of upper gastrointestinal function in humans.

The role of lipase in the regulation of upper gastrointestinal function is poorly understood. We studied the effect of orlistat, a new, potent, and highly specific lipase inhibitor, on gastric emptying, cholecystokinin (CCK) release, and pancreaticobiliary secretion. Three groups of studies were performed in nine healthy volunteers, using the double-indicator technique with a triple-lumen duodenal tube, polyethylene glycol 4000 as a duodenal perfusion marker, and 99mTc-diethylenetriamine pentaacetic acid as a meal marker. Gastric emptying, pancreaticobiliary output, and postprandial plasma CCK levels were measured after ingestion of the following isocaloric 500-ml liquid meals with or without 200 mg orlistat: 1) a pure fat meal (10% Intralipid), 2) a meal containing free fatty acids, or 3) an albumin-glucose meal. All experiments were performed in a randomized, placebo-controlled, crossover design. Orlistat markedly inhibited lipase activity in all three experiments. Orlistat given with the fat meal reduced CCK release and output of lipase, trypsin, and bilirubin and accelerated the rate of gastric emptying (P < 0.05). After ingestion of the free fatty acid or albumin-glucose meal, orlistat had no significant effect on any of these parameters. We conclude that lipase plays an important, nutrient-specific role in the regulation of gastric emptying and pancreaticobiliary secretion after ingestion of fatty meals in humans.

Regulation of gastric and pancreatic lipase secretion by CCK and cholinergic mechanisms in humans.

Gastric lipase (HGL) contributes significantly to fat digestion. However, little is known about its neurohormonal regulation in humans. We studied the role of CCK and cholinergic mechanisms in the postprandial regulation of HGL and pancreatic lipase (HPL) secretion in six healthy subjects. Gastric emptying of a mixed meal and outputs of HGL, pepsin, acid, and HPL were determined with a double-indicator technique. Three experiments were performed in random order: intravenous infusion of 1) placebo, 2) low-dose atropine (5 micrograms.kg-.h-1), and 3) the CCK-A receptor antagonist loxiglumide (22 mumol.kg-.h-1). Atropine decreased postprandial outputs of HGL, pepsin, gastric acid, and HPL (P < 0.03) while slowing gastric emptying (P < 0.05). Loxiglumide markedly increased the secretion of HGL, pepsin, and acid while distinctly reducing HPL outputs and accelerating gastric emptying (P < 0.03). Plasma CCK and gastrin levels increased during loxiglumide infusion (P < 0.03). Atropine enhanced gastrin but not CCK release. Postprandial HGL, pepsin, and acid secretion are under positive cholinergic but negative CCK control, whereas HPL is stimulated by cholinergic and CCK mechanisms. We conclude that CCK and cholinergic mechanisms have an important role in the coordination of HGL and HPL secretion to optimize digestion of dietary lipids in humans.

Role of cholecystokinin as a regulator of solid and liquid gastric emptying in humans.

The role of endogenous cholecystokinin (CCK) in the regulation of gastric emptying remains controversial. We therefore studied the effect of the CCK-A receptor antagonist loxiglumide on gastric emptying of a high-caloric solid-liquid meal in humans. Gastric emptying was assessed in eight volunteers using intravenous loxiglumide or placebo in a randomized double-blind order. Subjects were studied by a dual-headed gamma camera after ingestion of a pancake (570 kcal) labeled with 99mTc-sulfur colloid and 500 ml 10% glucose containing 111In-diethylenetriamine pentaacetic acid. Plasma CCK was measured by a specific radioimmunoassay. Loxiglumide markedly accelerated gastric emptying of both phases of the meal. The lag period was shortened by 26% (P < 0.03); the area under the emptying curve and half-emptying time of solid emptying were lowered by 19 and 24% (P < 0.02) and of liquid emptying by 18 and 24% (P < 0.04), respectively. Plasma CCK levels were higher during infusion of loxiglumide compared with placebo (P < 0.02). These data demonstrate that post-prandially released CCK is a major regulator of gastric emptying of physiological meals containing both solid and liquid components.

Measurement of proximal and distal gastric motility with magnetic resonance imaging.

The precise motor mechanisms associated with gastric emptying of nutrient liquids are unclear, in part because of difficulties in measuring the motility from the proximal and distal stomach simultaneously. We have now examined proximal and distal gastric motility, using a novel magnetic resonance imaging (MRI) technique. In seven healthy volunteers (4 males, 3 females; 27-37 yr), gastric emptying and motility were determined on two occasions after ingestion of 500 ml 10% and 25% dextrose labeled with 1 mM gadolinium tetraazacyclododecane tetraacetic acid, using a 1.5-tesla Philips Gyroscan ACS II scanner. Gastric emptying was determined every 15 min with a series of transaxial scans. After each series of transaxial scans, 120 coronal scans, 1.2 s apart, were performed through the antrum and proximal stomach. For each coronal slice the diameters of the proximal stomach and the antrum were measured to determine the number of contractions per minute and depth (%basal diameter). Gastric emptying (half-emptying time) was faster after ingestion of 10% compared with 25% dextrose (49 +/- 15 vs. 118 +/- 37 min; P < 0.01). After both meals, the diameter of the proximal stomach remained relatively constant, whereas there were marked fluctuations in the diameter of the antrum. Mean (+/- SD) frequency (2.8 +/- 0.6 vs. 2.0 +/- 0.8/min; P < 0.001) and depth (40 +/- 17% vs. 34 +/- 16%; P < 0.04) of antral contractions were higher after 10% dextrose compared with 25% dextrose. Rapid MRI techniques allow simultaneous measurement of both gastric emptying and motor function of different gastric regions. The increase in the frequency and depth of distal gastric contractions during ingestion of 10% compared with 25% dextrose supports the concept that the antrum contributes to the regulation of gastric emptying of nutrient liquids.

Gastric motility measurement by MRI.

The motor mechanisms associated with gastric emptying of nutrient liquids are unclear. Gastric emptying and motility were determined in seven healthy volunteers using an MRI technique following ingestion of 500 ml of (1) 10% and (2) 25% dextrose labeled with 1 mM Gd-DOTA. Emptying was determined with transaxial scans and motility during fast coronal scans 1.2 sec apart. Emptying was slower after ingestion of 25% dextrose. Following both meals, proximal gastric diameter remained relatively constant, while antral contractile frequency and depth varied markedly. These variations were greater after 10% dextrose. These studies suggest that antral motility changes contribute to slowing of gastric emptying by nutrient meals.