The potential role of a self-management intervention for ulcerative colitis: a brief report from the ulcerative colitis hypnotherapy trial.

Inflammatory bowel diseases (IBD) are chronic inflammatory illnesses marked by unpredictable disease flares, which occur spontaneously and/or in response to external triggers, especially personal health behaviors. Behavioral triggers of flare may be responsive to disease self-management programs. We report on interim findings of a randomized controlled trial of gut-directed hypnotherapy (HYP, n = 19) versus active attention control (CON, n = 17) for quiescent ulcerative colitis (UC). To date, 43 participants have enrolled; after 5 discontinuations (1 in HYP) and 2 exclusions due to excessive missing data, 36 were included in this preliminary analysis. Aim 1 was to determine the feasibility and acceptability of HYP in UC. This was achieved, demonstrated by a reasonable recruitment rate at our outpatient tertiary care clinic (20%), high retention rate (88% total), and our representative IBD sample, which is reflected by an equal distribution of gender, an age range between 21 and 69, recruitment of ethnic minorities (∽20%), and disease duration ranging from 1.5 to 35 years. Aim 2 was to estimate effect sizes on key clinical outcomes for use in future trials. Effect sizes (group × time at 20 weeks) were small to medium for IBD self-efficacy (.34), Inflammatory Bowel Disease Questionnaire (IBDQ) total score (.41), IBDQ bowel (.50), and systemic health (.48). Between-group effects were observed for the IBDQ bowel health subscale (HYP > CON; p = .05) at 20 weeks and the Short Form 12 Health Survey Version 2 (SF-12v2) physical component (HYP > CON; p < .05) at posttreatment and 20 weeks. This study supports future clinical trials testing gut-directed HYP as a relapse prevention tool for IBD.

Pressure morphology of the relaxed lower esophageal sphincter: the formation and collapse of the phrenic ampulla.

This study aimed to apply novel high-resolution manometry with eight-sector radial pressure resolution (3D-HRM technology) to resolve the deglutitive pressure morphology at the esophagogastric junction (EGJ) before, during, and after bolus transit. A hybrid HRM assembly, including a 9-cm-long 3D-HRM array, was used to record EGJ pressure morphology in 15 normal subjects. Concurrent videofluoroscopy was used to relate bolus movement to pressure morphology and EGJ anatomy, aided by an endoclip marking the squamocolumnar junction (SCJ). The contractile deceleration point (CDP) marked the time at which luminal clearance slowed to 1.1 cm/s and the location (4 cm proximal to the elevated SCJ) at which peristalsis terminated. The phrenic ampulla spanned from the CDP to the SCJ. The subsequent radial and axial collapse of the ampulla coincided with the reconstitution of the effaced and elongated lower esophageal sphincter (LES). Following ampullary emptying, the stretched LES (maximum length 4.0 cm) progressively collapsed to its baseline length of 1.9 cm (P < 0.001). The phrenic ampulla is a transient structure comprised of the stretched, effaced, and axially displaced LES that serves as a "yield zone" to facilitate bolus transfer to the stomach. During ampullary emptying, the LES circular muscle contracts, and longitudinal muscle shortens while that of the adjacent esophagus reelongates. The likely LES elongation with the formation of the ampulla and shortening to its native length after ampullary emptying suggest that reduction in the resting tone of the longitudinal muscle within the LES segment is a previously unrecognized component of LES relaxation.

Distensibility testing of the esophagus.

The following contains commentaries on distensibility testing using the functional lumen imaging probe (FLIP); the use of the distention test of the esophageal body in the clinic diagnosis of noncardiac chest pain; the functional lumen imaging in gastroesophageal reflux disease-impaired esophagogastric junction; a multimodal pain model for the esophagus; the rationale for distensibility testing; and further developments in standardized distension protocols.

Distal esophageal spasm in high-resolution esophageal pressure topography: defining clinical phenotypes.

BACKGROUND: The manometric diagnosis of distal esophageal spasm (DES) uses "simultaneous contractions" as a defining criterion, ignoring the concept of short latency distal contractions as an important feature. Our aim was to apply standardized metrics of contraction velocity and latency to high-resolution esophageal pressure topography (EPT) studies to refine the diagnosis of DES. METHODS: Two thousand consecutive EPT studies were analyzed for contractile front velocity (CFV) and distal latency to identify patients potentially having DES. Normal limits for CFV and distal latency were established from 75 control subjects. Clinical data of patients with reduced distal latency and/or rapid CFV were reviewed. RESULTS: Of 1070 evaluable patients, 91 (8.5%) had a high CFV and/or low distal latency. Patients with only rapid contractions (n = 186 [17.4%] using conventional manometry criteria; n = 85 [7.9%] using EPT criteria) were heterogeneous in diagnosis and symptoms, with the majority ultimately categorized as weak peristalsis or normal. In contrast, 96% of patients with premature contraction had dysphagia, and all (n = 24; 2.2% overall) were ultimately managed as spastic achalasia or DES. CONCLUSIONS: The current DES diagnostic paradigm focused on "simultaneous contractions" identifies a large heterogeneous set of patients, most of whom do not have a clinical syndrome suggestive of esophageal spasm. Incorporating distal latency into the diagnostic algorithm of EPT studies improves upon this by isolating disorders of homogeneous pathophysiology: DES with short latency and spastic achalasia. We hypothesize that prioritizing measurement of distal latency will refine the management of these disorders, recognizing that outcomes trials are necessary.

Mechanical properties of the esophagus in eosinophilic esophagitis.

BACKGROUND & AIMS: This study aimed to analyze the mechanical properties of the esophagus in eosinophilic esophagitis (EoE) using the functional luminal imaging probe (EndoFLIP; Crospon Medical Devices, Galway, Ireland). METHODS: Thirty-three EoE patients (22 male; age range, 23-67 years) and 15 controls (6 male; age range, 21-68 years) were included. Subjects were evaluated during endoscopy with the EndoFLIP probe, comprised of a compliant cylindrical bag (maximal diameter 25 mm) with 16 impedance planimetry segments. Stepwise bag distensions from 2 to 40 mL were conducted and the associated intrabag pressure and intraluminal geometry were analyzed. RESULTS: The EndoFLIP clearly displayed the tubular esophageal geometry and detected esophageal narrowing and localized strictures. Stepwise distension progressively opened the esophageal lumen until a distension plateau was reached such that the narrowest cross-sectional area (CSA) of the esophagus maximized despite further increases in intra-bag pressure. The esophageal distensibility (CSA vs pressure) was reduced in EoE patients (P = .02) with the distension plateau of EoE patients substantially lower than that of controls (median: CSA 267 mm(2) vs 438 mm(2); P < .01). Mucosal eosinophil count, age, sex, and current proton pump inhibitor treatment did not predict this limiting caliber of the esophagus (P ≥ 0.20). CONCLUSIONS: Esophageal distensibility, defined by the change in the narrowest measurable CSA within the distal esophagus vs intraluminal pressure was significantly reduced in EoE patients compared with controls. Measuring esophageal distensibility may be an important adjunct to the management of EoE, as it is capable of providing an objective means to measure the outcomes of medical or dilation therapy.

Weak peristalsis in esophageal pressure topography: classification and association with Dysphagia.

OBJECTIVES: Esophageal manometry is frequently used to assess for weak peristalsis. Although commonly used clinically, there are currently no validated metrics of weak peristalsis in high-resolution esophageal pressure topography (EPT). This study aimed to develop a classification of weak peristalsis in EPT based on a comparative analysis of control subjects and patients with unexplained non-obstructive dysphagia. METHODS: High-resolution esophageal pressure topography (high-resolution impedance manometry) studies were carried out in 16 control subjects to verify EPT features associated with incomplete bolus transit (IBT). The technique of superimposing EPT plots in a computer simulation was used to derive normal limits of peristaltic integrity in EPT in another 75 control subjects. The occurrence of critical EPT defects was then compared between control subjects and 113 patients with non-obstructive dysphagia identified from a large clinical series. RESULTS: IBT occurred with failed peristalsis or with breaks in the 20 mm Hg isobaric contour occurring at the proximal or distal pressure troughs in EPT plots. The normal range for isobaric contour breaks was 0-20% for large (>5 cm) and 0-30% for small (2-5 cm) breaks, with both occurring significantly more frequently in dysphagic patients. Failed peristalsis was not more frequent in dysphagic patients. CONCLUSIONS: A classification of weak peristalsis adapted to EPT is proposed based on the occurrence of breaks in the 20 mm Hg isobaric contour wherein weak peristalsis with large breaks is defined by those occurring with >20% of swallows and weak peristalsis with small breaks defined by those occurring with >30% of swallows.

Esophagogastric junction distensibility assessed with an endoscopic functional luminal imaging probe (EndoFLIP).

BACKGROUND: Increased esophagogastric junction (EGJ) compliance is a key abnormality in GERD leading to increased volumes of reflux. To date, EGJ distensibility has been measured only with investigational barostat-based prototype devices. OBJECTIVES: The aim of the study was to test the endoscopic functional luminal imaging probe (EndoFLIP), a new commercially available technology designed to measure intraluminal distensibility, by assessing the EGJ of GERD patients and controls. DESIGN: Prospective case-control series. SETTING: Tertiary referral center. SUBJECTS: Twenty GERD patients and 20 controls studied during a routine esophagogastroduodenoscopy. METHODS: The EndoFLIP was passed through the endoscopic instrumentation channel and positioned across the EGJ. The EndoFLIP uses impedance planimetry to measure 16 cross-sectional areas (CSA) along with the corresponding intrabag pressure within a 4.6-cm cylindrical segment of a fluid-filled bag. MAIN OUTCOME MEASUREMENT: EGJ distensibility was assessed with 10- to 40-mL volume-controlled distentions. RESULTS: In both groups, the least distensible locus at the EGJ was usually at the hiatus. As a group, GERD patients exhibited two- to threefold increased EGJ distensibility compared with controls, particularly at 20- to 30-mL distention volumes, values quantitatively similar to previous measurements with barostat-based devices. The endoscopic estimation of EGJ distensibility, the flap valve grade, correlated poorly with EndoFLIP measurements. LIMITATIONS: Heterogeneity of GERD patients. CONCLUSIONS: Measurement of EGJ distensibility with EndoFLIP is feasible during clinical endoscopy. Stratifying GERD patients according to this physiological parameter may facilitate the identification of patient subgroups responsive or unresponsive to medical or surgical treatments.

Esophagogastric junction distensibility after fundoplication assessed with a novel functional luminal imaging probe.

OBJECTIVE: The aim of the study was to compare the esophagogastric junction (EGJ) compliance in response to controlled distension in fundoplication (FP) patients and controls using the functional luminal imaging probe (FLIP). BACKGROUND: FP aims to replicate normal EGJ distensibility. FLIP is a new technology that uses impedance planimetry to measure intraluminal cross-sectional area (CSA) during controlled distension. METHODS: Ten controls and ten FP patients were studied with high-resolution esophageal pressure topography (HREPT) and then the FLIP placed across the EGJ. Deglutitive and interdeglutitive EGJ distensibility was assessed with volume-controlled distension. The FLIP measured eight CSAs spaced 4 mm apart within a cylindrical saline-filled bag along with the corresponding intrabag pressure. RESULTS: The EGJ formed an hourglass shape during distensions with the central constriction at the diaphragmatic hiatus. The distensibility of the hiatus was significantly greater during deglutitive relaxation in both subject groups, but FP patients exhibited reduced EGJ distensibility and compliance compared to controls. During the interglutitive period, the corresponding increase in intrabag pressures at larger volumes were also greater in FP patients implying a longer segment of EGJ constriction. The EGJ distensibility characteristics did not correlate with HREPT measures. CONCLUSIONS: FLIP technology was used to compare EGJ distensibility in FP patients and control subjects. The least distensible locus within the EGJ was always at the hiatus. EGJ distensibility was significantly reduced, and the length of constriction increased in FP patients. Future FLIP studies will compare patients with and without post-FP dysphagia and gas bloat, symptoms suggestive of an overly restrictive FP.

Unique features of esophagogastric junction pressure topography in hiatus hernia patients with dysphagia.

BACKGROUND: Our aim was to assess pressure dynamics within the esophagogastric junction (EGJ) in sliding hiatus hernia (HH) during normal peristalsis and to compare the pressure profiles of HH patients with gastroesophageal reflux disease (GERD) symptoms (HH-GERD) to HH patients with dysphagia (HH-dysphagia). METHODS: High-resolution manometry studies in 230 consecutive patients and 68 controls were reviewed. HH patients were defined by a >or=1.5 cm separation between the lower esophageal sphincter (LES) and crural diaphragm (CD) on pressure topography plots. The HH population was further culled to eliminate those patients with motor disorders or stricture. The study groups were composed of 18 HH patients with only reflux symptoms and 10 HH patients with only dysphagia. Analysis of the pressure dynamics within the EGJ was performed at rest and after swallowing to independently quantify the LES and CD contributions to residual EGJ pressure, as well as the magnitude and genesis of distal esophageal intrabolus pressure (IBP). Differences among study groups were analyzed with analysis of variance. RESULTS: After swallows, HH-dysphagia patients had greater residual CD pressure (9 mmHg; standard deviation [SD], 4) and IBP pressure (19 mmHg; SD, 4) compared to HH-GERD patients (5 mmHg; SD, 2; and 12 mmHg; SD, 2, respectively; P<.001) or normal subjects (NA; 11 mmHg; SD, 3; P<.001). CONCLUSION: Sliding HH alters the pressure dynamics through the EGJ and can lead to a functional obstruction. Patients with HH and dysphagia have greater pressures through the CD compared to HH patients with GERD symptoms, supporting the hypothesis that sliding HH in and of itself may be responsible for dysphagia.

Effect of meal volume and calorie load on postprandial gastric function and emptying: studies under physiological conditions by combined fiber-optic pressure measurement and MRI.

This study assessed the effects of meal volume (MV) and calorie load (CL) on gastric function. MRI and a minimally invasive fiber-optic recording system (FORS) provided simultaneous measurement of gastric volume and pressure changes during gastric filling and emptying of a liquid nutrient meal in physiological conditions. The gastric response to 12 iso-osmolar MV-CL combinations of a multinutrient drink (MV: 200, 400, 600, 800 ml; CL: 200, 300, 400 kcal) was tested in 16 healthy subjects according to a factorial design. Total gastric volume (TGV) and gastric content volume (GCV = MV + secretion) were measured by MRI during nasogastric meal infusion and gastric emptying over 60 min. Intragastric pressure was assessed at 1 Hz by FORS. The dynamic change in postprandial gastric volumes was described by a validated three-component linear exponential model. The stomach expanded with MV, but the ratio of GCV:MV at t(0) diminished with increasing MV (P < 0.01). Postprandial changes in TGV followed those of GCV. Intragastric pressure increased with MV, and this effect was augmented further by CL (P = 0.02); however, the absolute pressure rise was <4 mmHg. A further postprandial increase of gastric volumes was observed early on before any subsequent volume decrease. This "early" increase in GCV was greater for smaller than larger MV (P < 0.01), indicating faster initial gastric emptying of larger MV. In contrast, volume change during filling and in the early postprandial period were unaffected by CL. In the later postprandial period, gastric emptying rate continued to be more rapid with high MVs (P < 0.001); however, at any given volume, gastric emptying was slowed by higher CL (P < 0.001). GCV half-emptying time decreased with CL at 18 +/- 6 min for each additional 100-kcal load (P < 0.001). These findings indicate that gastric wall stress (passive strain and active tone) provides the driving force for gastric emptying, but distal resistance to gastric outflow regulates further passage of nutrients. The distinct early phase of gastric emptying with relatively rapid, uncontrolled passage of nutrients into the small bowel, modulated by meal volume but not nutrient composition, ensures that the delivery of nutrients in the later postprandial period is related to the overall calorie load of the meal.

Functional esophagogastric junction obstruction with intact peristalsis: a heterogeneous syndrome sometimes akin to achalasia.

BACKGROUND: Some patients with suspected achalasia are found on manometry to have preserved peristalsis, thereby excluding that diagnosis. This study evaluated a series of such patients with functional esophagogastric junction (EGJ) obstruction. METHODS: Among 1,000 consecutive high-resolution manometry studies, 16 patients had functional EGJ obstruction characterized by impaired EGJ relaxation and intact peristalsis. Eight patients with post-fundoplication dysphagia and similarly impaired EGJ relaxation were studied as a comparator group with mechanical obstruction. Intrabolus pressure (IBP) was measured 1 cm proximal to the EGJ. Sixty-eight normal controls were used to define normal IBP. Patients' clinical features were evaluated. RESULTS: Functional EGJ obstruction patients presented with dysphagia (96%) and/or chest pain (42%). IBP was significantly elevated in idiopathic and post-fundoplication dysphagia patients versus controls. Among the idiopathic EGJ obstruction group treated with pneumatic dilation, BoTox(TM), or Heller myotomy, only the three treated with Heller myotomy responded well. Among the post-fundoplication dysphagia patients, three of four responded well to redo operations. CONCLUSION: Functional EGJ obstruction is characterized by pressure topography metrics demonstrating EGJ outflow obstruction of magnitude comparable to that seen with post-fundoplication dysphagia. Affected patients experience dysphagia and/or chest pain. In some cases, functional EGJ obstruction may represent an incomplete achalasia syndrome.

Esophageal pressure topography criteria indicative of incomplete bolus clearance: a study using high-resolution impedance manometry.

OBJECTIVES: This study used high-resolution impedance manometry (HRIM) to determine pressure topography thresholds of peristaltic integrity predictive of incomplete esophageal bolus clearance. METHODS: A total of 16 normal controls and 8 patients with dysphagia were studied using a solid-state HRIM assembly incorporating 36 manometric sensors and 12 impedance segments. Each of the 10 saline swallows in each study was dichotomously scored as either complete or incomplete bolus clearance by impedance criteria, and peristaltic integrity was evaluated using pressure topography isobaric contours ranging from 10 to 30 mm Hg in 5- mm Hg increments. Each isobaric contour plot was characterized by the location and length of breaks in the isobaric contour. RESULTS: All subjects had normal esophagogastric junction (EGJ) relaxation and none met the pressure topography criteria of hiatus hernia. In all, 70 (29%) of the 240 individual swallows had incomplete bolus clearance. In every case, an intact >or=20 mm Hg isobaric contour was associated with complete bolus clearance. The largest defect in the 20 and 30 mm Hg isobaric contours associated with complete bolus clearance measured 1.7 and 3.0 cm, respectively, in length, whereas the smallest defect predictive of incomplete bolus clearance measured 2.1 and 3.2 cm, respectively. CONCLUSIONS: In individuals with normal EGJ relaxation and morphology, peristaltic contractions with breaks <2 cm in the 20 mm Hg isobaric contour or <3 cm in the 30 mm Hg isobaric contour are associated with complete bolus clearance, and longer breaks predict incomplete bolus clearance.

Hyperdynamic upper esophageal sphincter pressure: a manometric observation in patients reporting globus sensation.

OBJECTIVES: Although globus sensation is a common symptom, its pathogenesis is poorly defined. The aim of this study was to quantify the timing and magnitude of respiratory variation in upper esophageal sphincter (UES) pressure with high-resolution manometry (HRM) in patients with globus sensation, normal controls, and gastroesophageal reflux disease (GERD) patients without globus sensation. METHODS: HRM recordings spanning from the hypopharynx to the stomach were analyzed in 131 consecutive globus patients with normal (64) and abnormal (67) distal esophageal motility. Resting UES pressure was analyzed up to 5 min before 10 5-ml water swallows. Change in UES pressure, its average magnitude between inspiration and expiration, and nadir UES relaxation pressure in globus patients were compared with those in 68 controls and 46 GERD patients without globus. RESULTS: UES pressure typically increased during inspiration in both controls and patients. Respiration-related change in resting UES pressure was significantly amplified in globus patients (37.3 mm Hg) compared with controls (10.6 mm Hg) and GERD patients (13.0 mm Hg) (P<0.0001). A respiratory change in UES pressure>27 mm Hg was found in >60% of globus patients and <15% of controls and GERD patients without globus. This hyperdynamic UES was not associated with other abnormalities of esophageal motor function. CONCLUSIONS: Hyperdynamic respiratory UES pressure changes were prevalent in patients reporting globus sensation irrespective of their deglutitive UES and distal esophageal motility. Although the etiology of this hyperdynamic UES is unclear, it does appear to be a frequent manometric observation in this patient group and may provide a new focus for further studies into pathogenesis and therapy.

The pathophysiologic basis for epidemiologic trends in gastroesophageal reflux disease.

Gastroesophageal reflux disease (GERD) is defined by either subjective complaints indicative of problematic gastroesophageal reflux or objective complications directly attributable to reflux. Studies focused on GERD-related symptoms suggest a worldwide increase in prevalence of approximately 4% per year. Epidemiologic data indicate that possible contributing factors include increasing longevity, rising obesity rates, greater consumption of medications affecting esophageal function, and potentially changing prevalence rates of Helicobacter pylori infection. This article explores the interplay between pathophysiology and epidemiology by focusing on these risk factors and their potential effect on GERD pathogenesis.

Achalasia: a new clinically relevant classification by high-resolution manometry.

BACKGROUND & AIMS: Although the diagnosis of achalasia hinges on demonstrating impaired esophagogastric junction (EGJ) relaxation and aperistalsis, 3 distinct patterns of aperistalsis are discernable with high-resolution manometry (HRM). This study aimed to compare the clinical characteristics and treatment response of these 3 subtypes. METHODS: One thousand clinical HRM studies were reviewed, and 213 patients with impaired EGJ relaxation were identified. These were categorized into 4 groups: achalasia with minimal esophageal pressurization (type I, classic), achalasia with esophageal compression (type II), achalasia with spasm (type III), and functional obstruction with some preserved peristalsis. Clinical and manometric variables including treatment response were compared among the 3 achalasia subtypes. Logistic regression analysis was performed using treatment success as the dichotomous dependent variable controlling for independent manometric and clinical variables. RESULTS: Ninety-nine patients were newly diagnosed with achalasia (21 type I, 49 type II, 29 type III), and 83 of these had sufficient follow-up to analyze treatment response. Type II patients were significantly more likely to respond to any therapy (BoTox [71%], pneumatic dilation [91%], or Heller myotomy [100%]) than type I (56% overall) or type III (29% overall) patients. Logistic regression analysis found type II to be a predictor of positive treatment response, whereas type III and pretreatment esophageal dilatation were predictive of negative treatment response. CONCLUSIONS: Achalasia can be categorized into 3 subtypes that are distinct in terms of their responsiveness to medical or surgical therapies. Utilizing these subclassifications would likely strengthen future prospective studies of treatment efficacy in achalasia.

Use and utility of the Bravo pH capsule.

The single technological advancement that Bravo pH monitoring offers over conventional pH monitoring is the elimination of the transnasal catheter. This was not a trivial advance in terms of technologic achievement. Development of a delivery system that could temporarily place a wireless capsule on the esophageal mucosa was extremely difficult to envision given the fact that the esophageal body is not conducive to retaining a foreign body. Thus, the delivery system and the ability to attach the pH capsule to the wall are what make the Bravo system unique. This approach has the potential to improve tolerance and obtain pH studies for durations greater than 24 hours; however, it still lacks the ability to measure nonacid reflux and also the ability to distinguish swallow events from true reflux. This review will highlight the advantages of the Bravo system and how it should be used.

Classifying esophageal motility by pressure topography characteristics: a study of 400 patients and 75 controls.

AIM: This study aimed to devise a scheme for the systematic analysis of esophageal high-resolution manometry (HRM) studies displayed using topographic plotting. METHODS: A total of 400 patients and 75 control subjects were studied with a 36-channel HRM assembly. Studies were analyzed in a stepwise fashion for: (a) the adequacy of deglutitive esophagogastric junction (EGJ) relaxation, (b) the presence and propagation characteristics of distal esophageal persitalsis, and (c) an integral of the magnitude and span of the distal esophageal contraction. RESULTS: Two strengths of pressure topography plots compared to conventional manometric recordings were: (a) the ability to delineate the spatial limits, vigor, and integrity of individual contractile segments along the esophagus, and (b) the ability to distinguish between loci of compartmentalized intraesophageal pressurization and rapidly propagated contractions. Making these distinctions objectified the identification of distal esophageal spasm (DES), vigorous achalasia, functional obstruction, and nutcracker esophagus subtypes. Applying these distinctions made the diagnosis of spastic disorders quite rare: (a) DES in 1.5% patients, (b) vigorous achalasia in 1.5%, and (c) a newly defined entity, spastic nutcracker, in 1.5%. CONCLUSIONS: We developed a systematic approach to analyzing esophageal motility using HRM and pressure topography plots. The resultant scheme is consistent with conventional classifications with the caveats that: (a) hypercontractile conditions are more specifically defined, (b) distinctions are made between rapidly propagated contractions and compartmentalized esophageal pressurization, and (c) there is no "nonspecific esophageal motor disorder" classification. We expect that pressure topography analysis, with its well-defined functional implications, will prove valuable in the clinical management of esophageal motility disorders.

The effect of macronutrients on gastric volume responses and gastric emptying in humans: A magnetic resonance imaging study.

The effects of macronutrients on gastric volume changes, emptying, and gastrointestinal symptoms are incompletely understood. Three liquid meals of 500 ml (fat emulsion, 375 kcal; protein solution, 375 kcal; glucose solution, 400 kcal) were infused into the stomach of 12 healthy volunteers on three occasions. Studies were performed in seated body position using an open-configuration magnetic resonance imaging (MRI) system. MRI imaging sequences, assessing stomach and meal volumes, were performed prior to and at times t = 0, 3, 6, 9, 12, 15, 25, 35, 45, 60, 75, and 90 min after meal administration. Areas under the curve for the early emptying phase (0-15 and 0-45 min) were calculated, and characteristics of the volume curves were analyzed by a gastric emptying model. Gastrointestinal symptoms were assessed by a self-report scale. Initial (t = 0 min) and early postprandial gastric volumes were highest for glucose because of lower initial emptying. However, in the early emptying phase the characteristics of the volume curves for stomach and meal were uniform for all macronutrients. Perceptions of fullness and satiety were linearly associated with postprandial gastric volumes, but not with macronutrient composition. Isovolumic macronutrient meals modulate gastric volume response by initial meal emptying patterns. Macronutrient specific accommodation responses, as shown in barostat studies, are not reflected as gastric volume responses under noninvasive conditions.

Quantification of distal antral contractile motility in healthy human stomach with magnetic resonance imaging.

PURPOSE: To quantify healthy postprandial: 1) propagation, periodicity, geometry, and percentage occlusion by distal antral contraction waves (ACWs); and 2) changes in ACW activity in relationship to gastric emptying (GE). MATERIALS AND METHODS: Using 1.5-T MR scanner, nine healthy fasted volunteers were examined in the right decubitus position after ingestion of 500 mL of 10% glucose (200 kcal) with 500 microM Gd-DOTA. Total gastric (TGV) and meal volumes (MV) were assessed every five minutes for 90 minutes, in and interspersed with dynamic scan sequences (duration: 2.78 minutes) providing detailed images of distal ACWs. RESULTS: TGV increased by 738+/-38 mL after ingestion (t0), subsequently decreasing in parallel to GE. The mean GE rate and half-emptying time were 24+/-3 mL/5 minutes and 71+/-6 minutes, respectively. Accompanying ACWs reached a periodicity of 23+/-2 seconds at t35 and propagated at an unvarying speed of 0.27+/-0.01 cm/second. Their amplitude of 0.70+/-0.08 cm was constant, but the width decreased along the antral wall by 6+/-2%/cm (P=0.003). ACWs were nonocclusive (percentage occlusion 58.1+/-5.9%, t0 at the pylorus) with a reduction in occlusion away from the pylorus (P<0.001). No propagation and geometry characteristics of ACWs correlated with the changes of MV (mL/5 minutes; R2<0.05). CONCLUSION: Our results indicate that ACWs are not imperative for emptying of liquids. This study provides a detailed quantitative reference for MRI inquiries into pharmacologically- and pathologically-altered gastric motility.

Uridine supplementation enhances hepatic mitochondrial function in thymidine-analogue treated HIV-infected patients.

Supplementation with uridine offers the possibility of a new and promising approach to nucleoside analogue reverse transcriptase inhibitor-associated mitochondrial toxicity. We investigated the metabolic effects of short-course treatment with the uridine-enriched food supplement NucleomaxX on hepatic mitochondrial function in thymidine-analogue treated HIV-infected patients. Mitochondrial function was assessed by a recently introduced non-invasive C-methionine breath test. NucleomaxX supplementation enhanced mitochondrial decarboxylation function reversibly but reproducibly in all patients. Repeated administration in shorter treatment intervals may maintain this effect.