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s. k. ghosh p. janiak † m. fox † w. schwizer † g. s. hebbard ‡ & j. g. brasseur 《Neurogastroenterology and motility》2008,20(7):750-759
Abstract Distinct contraction waves (CWs) exist above and below the transition zone (TZ) between the striated and smooth muscle oesophagus. We hypothesize that bolus transport is impaired in patients with abnormal spatio-temporal coordination and/or contractile pressure in the TZ. Concurrent high resolution manometry and digital fluoroscopy were performed in healthy subjects and patients with reflux oesophagitis; a condition associated with ineffective oesophageal contractility and clearance. A detailed analysis of space–time variations in bolus movement, intra-bolus and intra-luminal pressure was performed on 17 normal studies and nine studies in oesophagitis patients with impaired bolus transit using an interactive computer based system. Compared with normal controls, oesophagitis patients had greater spatial separation between the upper and lower CW tails [median 5.2 cm (range 4.4–5.6) vs 3.1 cm (2.2–3.7)], the average relative pressure within the TZ region (TZ strength) was lower [30.8 mmHg (28.3–36.5) vs 45.8 mmHg (36.1–55.7), P < 0.001], and the risk of bolus retention was higher (90% vs 12%; P < 0.01). The presence of bolus retention was associated with a wider spatial separation of the upper and lower CWs (>3 cm, the upper limit of normal; P < 0.002), independent of the presence of oesophagitis. We conclude that bolus retention in the TZ is associated with excessively wide spatial separation between the upper and lower CWs and lower TZ muscle squeeze. These findings provide a physio-mechanical basis for the occurrence of bolus retention at the level of the aortic arch, and may underlie impaired clearance with reflux oesophagitis. 相似文献
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Are the Spanish baseline series markers sufficient to detect contact allergy to corticosteroids in Spain? A GEIDAC prospective study 下载免费PDF全文
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m. a. kwiatek m. r. fox a. steingoetter † d. menne ‡ a. pal § h. fruehauf e. kaufman z. forras-kaufman j. g. brasseur § o. goetze g. s. hebbard ¶ p. boesiger † m. thumshirn m. fried & w. schwizer 《Neurogastroenterology and motility》2009,21(9):928-e71
Abstract Gastric emptying (GE) may be driven by tonic contraction of the stomach (‘pressure pump’) or antral contraction waves (ACW) (‘peristaltic pump’). The mechanism underlying GE was studied by contrasting the effects of clonidine (α2‐adrenergic agonist) and sumatriptan (5‐HT1 agonist) on gastric function. Magnetic resonance imaging provided non‐invasive assessment of gastric volume responses, ACW and GE in nine healthy volunteers. Investigations were performed in the right decubitus position after ingestion of 500 mL of 10% glucose (200 kcal) under placebo [0.9% NaCl intravenous (IV) and subcutaneous (SC)], clonidine [0.01 mg min?1 IV, max 0.1 mg (placebo SC)] or sumatriptan [6 mg SC (placebo IV)]. Total gastric volume (TGV) and gastric content volume (GCV) were assessed every 5 min for 90 min, interspersed with dynamic scan sequences to measure ACW activity. During gastric filling, TGV increased with GCV indicating that meal volume dictates initial relaxation. Gastric contents volume continued to increase over the early postprandial period due to gastric secretion surpassing initial gastric emptying. Clonidine diminished this early increase in GCV, reduced gastric relaxation, decreased ACW frequency compared with placebo. Gastric emptying (GE) rate increased. Sumatriptan had no effect on initial GCV, but prolonged gastric relaxation and disrupted ACW activity. Gastric emptying was delayed. There was a negative correlation between gastric relaxation and GE rate (r2 = 49%, P < 0.001), whereas the association between ACW frequency and GE rate was inconsistent and weak (r2 = 15%, P = 0.05). These findings support the hypothesis that nutrient liquid emptying is primarily driven by the ‘pressure pump’ mechanism. 相似文献
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