Esophagogastric junction outflow obstruction: Characterization of a new entity? Clinical, manometric, and neuroimmunological description.

OBJECTIVE: To determine the differences between clinical, manometric, and neuroimmunological profile of esophagogastric junction outflow obstruction (EGJOO) and achalasia patients. METHODS: Seven EGJOO and 27 achalasia patients were enrolled in a blind cross-sectional study. Peripheral blood (PB) of 10 healthy donors and 10 lower esophageal sphincter (LES) muscle biopsies from organ transplant donors were included as controls. The presence of ganglion cells, cells of Cajal, Th22/Th7/Th2/Th1/Tregs/Bregs/pDCregs in tissue, and PB was assessed by immunohistochemistry and flow cytometry. Serum concentration of IL-22/IL-17A/IL-17F/IL-4/IFN-γ/IL-1ß/IL-6/IL-23/IL-33/TNF-α/IL-10 was determined using bioplex plates. ANAs and antineuronal antibodies were evaluated by immunofluorescence and Western blot. KEY RESULTS: EGJOO and achalasia patients had lower ganglion cells and cells of Cajal percentage vs. controls, while fibrosis was present only in achalasia patients. EGJOO and controls had lower cell percentage of Th22/Th17/Th2 vs. achalasia. EGJOO tissue had lower Th1/Treg cell number vs. achalasia, but higher levels vs. control group. Bregs and pDCregs percentage was higher in EGJOO vs. control group. Percentage of PB subpopulations in EGJOO was not significantly different from control group. Serum cytokine levels were higher for IL-1ß/IL-6/TNF-α, while IL-17A levels were lower in EGJOO vs. achalasia and control group. EGJOO group was negative for ANAs, while in achalasia group, 54% were positive. GAD65 and PNMa/Ta2 antibodies were present in achalasia, whereas Yo and recoverin were positive in EGJOO group. CONCLUSIONS AND INFERENCES: Although EGJOO shares some clinical characteristics with achalasia, the neuroimmunological profile is completely different, suggesting that EGJOO might be a different entity.

The effect of platelet-rich plasma on motility changes in experimental caustic esophageal burn.

BACKGROUND: Besides stricture formation, diminished esophageal motility after caustic esophageal burns also plays a role in the deterioration of the clinical course. In this study, we aimed to investigate the effect of caustic burn on the esophageal contractions and the effect of platelet-rich plasma (PRP) on these changes. METHODS: Twenty-one Wistar albino rats were divided into three groups [Sham operation (n = 8), caustic esophageal burn with NaOH (n = 6), PRP treatment after caustic burn (n = 7)]. After 3 weeks, esophagectomy was performed and contractions and EFS responses were evaluated in the organ bath. RESULTS: KCl- and acetylcholine-induced responses were reduced in the Burn group, but increased in Sham and PRP groups (p < 0.05). EFS responses were higher in Burn group compared to the other groups. Response with L-arginine was increased in Burn group, but decreased in PRP group. There was more decrease in the contraction in Sham and PRP groups compared to the Burn group after SNP (sodium nitroprusside) incubation (p < 0.05). L-NAME (Nω-Nitro-L-arginine methyl ester) did not change the EFS responses in the Burn group, but EFS responses were decreased significantly in Sham and PRP groups (p < 0.05). EFS responses were decreased in all groups, but more in the Sham and PRP groups after Y-27632 (Rho-kinase inhibitor) incubation (p < 0.05). CONCLUSIONS: For the first time, we demonstrated that both cholinergic and non-adrenergic non-cholinergic mechanisms are responsible for the altered motility in corrosive esophageal injury. Our results suggest that PRP treatment may be helpful in regulating the esophageal motility and decreasing altered contractions in corrosive burns. This effect may also contribute to the reduction of stricture formation, especially by reducing inappropriate contractions of the esophageal wall during the post-burn healing phase.

Persistent mechanical stretch-induced calcium overload and MAPK signal activation contributed to SCF reduction in colonic smooth muscle in vivo and in vitro.

Gastrointestinal (GI) distention is a common pathological characteristic in most GI motility disorders (GMDs), however, their detail mechanism remains unknown. In this study, we focused on Ca2+ overload of smooth muscle, which is an early intracellular reaction to stretch, and its downstream MAPK signaling and also reduction of SCF in vivo and in vitro. We successfully established colonic dilation mouse model by keeping incomplete colon obstruction for 8 days. The results showed that persistent colonic dilation clearly induced Ca2+ overload and activated all the three MAPK family members including JNK, ERK and p38 in smooth muscle tissues. Similar results were obtained from dilated colon of patients with Hirschsprung's disease and stretched primary mouse colonic smooth muscle cells (SMCs). Furthermore, we demonstrated that persistent stretch-induced Ca2+ overload was originated from extracellular Ca2+ influx and endoplasmic reticulum (ER) Ca2+ release identified by treating with different Ca2+ channel blockers, and was responsible for the persistent activation of MAPK signaling and SCF reduction in colonic SMCs. Our results suggested that Ca2+ overload caused by smooth muscle stretch led to persistent activation of MAPK signaling which might contribute to the decrease of SCF and development of the GMDs.

Upper Gastrointestinal Tract Motility Disorders in Women, Gastroparesis, and Gastroesophageal Reflux Disease.

This article reviews the sex differences in upper gastrointestinal (GI) motility for both healthy and common dysmotility conditions. It focuses on gastroesophageal reflux disease and other esophageal motor disorders for the esophagus and on gastroparesis and accelerated gastric emptying for the stomach. It also describes differences in upper GI motility signs and symptoms during each female hormonal stage (ie, menstrual cycle, pregnancy, perimenopause, menopause) for both healthy participants and those suffering from one of the aforementioned upper GI dysmotility conditions. More research still needs to be conducted to better understand sex differences in upper GI motility.

Neuropatía entérica asociada a diabetes mellitus / Enteric neuropathy associated to diabetes mellitus

La diabetes mellitus (DM) es un conjunto de enfermedades de gran prevalencia en la actualidad. Sus diferentes variantes se caracterizan por producir síntomas muy semejantes con complicaciones agudas y crónicas. Entre estas se encuentra la dismotilidad gastrointestinal (GI) asociada al desarrollo de neuropatía en el sistema nervioso entérico (SNE). El objetivo de este artículo es revisar los conocimientos sobre la dismotilidad GI y la neuropatía entérica asociada a diabetes mellitus. Para ello se describen las diversas alteraciones funcionales y estructurales encontradas en el sistema digestivo tanto en el hombre como en diversos modelos animales de diabetes. Para finalizar, se hace un breve resumen de las estrategias de tratamiento y prevención de la neuropatía diabética entérica que se han considerado hasta la fecha. En conclusión, entre las alteraciones descritas en la DM destaca especialmente la pérdida de inervación intrínseca inhibidora. Como posibles estrategias terapéuticas y/o preventivas se propone desde el uso de insulina, el factor de crecimiento nervioso y antioxidantes hasta el trasplante de neuronas mientéricas

Diabetes mellitus (DM) is a group of diseases highly prevalent nowadays. Its different types produce very similar symptoms with acute and chronic complications. Amongst these, gastrointestinal (GI) dysmotility, associated with the development of neuropathy in the enteric nervous system (ENS) is recognized. The objective is to review the current knowledge on GI dysmotility and enteric neuropathy associated to diabetes mellitus. The different functional and structural alterations within the digestive tract in diabetic patients and animal models are described. Finally, the therapeutic and preventive strategies tested so far in the context of enteric diabetic neuropathy are briefly summarized. In conclusion, amongst the alterations described in DM, the loss of inhibitory intrinsic innervation of the gut is most remarkable. Different therapeutic and/or preventive strategies, including the use of insulin, nerve growth factor or antioxidants, as well as myenteric neuron transplantation, are proposed

Lactulose breath test to assess oro-cecal transit delay and estimate esophageal dysmotility in scleroderma patients.

OBJECTIVES: To assess the correlation between delayed oro-cecal transit time (OCTT) and esophageal motility abnormalities in a cohort of systemic sclerosis (SSc) patients. METHODS: We prospectively enrolled 50 consecutive SSc patients and 60 healthy volunteers (HVs) as controls. Both groups underwent glucose breath test (GBT) to exclude small intestine bacterial overgrowth, lactulose hydrogen, and octanoic acid breath tests (LHBT and OBT) to measure OCTT and gastric emptying (GE), respectively, and manometry to assess esophageal motility. RESULTS: Thirty-one (63%) SSc patients presented ineffective esophageal motility (IEM) compared with 3 HVs (5%; P<0.01), 37 (74%) had an abnormal OCTT compared with 4 HVs (7%; P <0.01), and 16 (32%) had an altered GE compared with 4 HVs (7%; P <0.01). The median OCTT and gastric t½ were longer in SSc than in HVs (165 min vs. 101 min and 125 min vs. 78 min, respectively; P <0.01). A delayed GE was present in 12/37 (32%), whereas IEM in 27/37 (73%) SSc patients with prolonged OCTT. The prevalence of IEM increased in parallel with the prolongation of OCTT (31% when OCTT<150 min, 73% when OCTT≥150 min, and up to 85% when OCTT>180 min, P<0.01). CONCLUSIONS: Abnormalities of both esophageal and small intestine motility are frequent in SSc patients and esophageal motility is altered in most cases with small bowel involvement. Delayed GE plays a limited role in prolonging OCTT. LHBT is a non-invasive, cheap, well-tolerated diagnostic tool that may be useful to estimate intestinal involvement and also to estimate a higher risk of esophageal hypomotility in SSc patients.

Evolving pharmacological approaches in gastroesophageal reflux disease.

INTRODUCTION: Proton pump inhibitors (PPIs) have considerably improved quality of life in patients with gastroesophageal reflux disease (GERD). However, many patients remain symptomatic despite standard PPI therapy. AREAS COVERED: This review focuses on evolving therapeutic strategies related to the pathophysiological processes of GERD and insufficient response to PPIs. Several clinical trials evaluated new PPI formulations and newer types of acid-suppressive drugs. These studies have evaluated traditional end points in GERD, but have not shown clinical superiority to current PPIs. Novel therapeutic strategies targeting underlying mechanisms of GERD, such as transient lower esophageal sphincter relaxations (TLESRs) and esophageal hypersensitivity, are being developed for add-on therapy to PPIs. Prokinetic drugs may also have some potential in the add-on treatment of GERD with insufficient response to PPIs. Add-on studies are hampered by insufficient information on optimal patient selection and lack of established end points. EXPERT OPINION: Newer drugs for symptomatic control in GERD have largely focused on improved acid suppression, without evidence of clinical superiority. Drugs targeting esophageal motility and sensitivity to be used as add-onc therapy in PPI insufficient responders have not reached Phase III trials to date, due to difficulties with patient selection, tolerability and end points.

Esophageal functional impairments in experimental eosinophilic esophagitis.

Eosinophilic esophagitis (EoE) is an emerging chronic esophageal disease. Despite the increasing diagnosis of EoE globally, the causes of EoE and other esophageal eosinophilic disorders are not clearly understood. EoE pathology includes accumulation of inflammatory cells (e.g., eosinophils, mast cells), characteristic endoscopic features (e.g., furrows, the formation of fine concentric mucosal rings, exudates), and functional impairments (e.g., esophageal stricture, dysmotility). We hypothesized that the esophageal structural pathology and functional impairments of EoE develop as a consequence of the effector functions of the accumulated inflammatory cells. We analyzed eosinophils (anti-major basic protein immunostaining), esophageal stricture (X-ray barium swallowing), and esophageal motility (isometric force) in two established transgenic murine models of EoE (CD2-IL-5 and rtTA-CC10-IL-13) and a novel eosinophil-deficient model (ΔdblGATA/CD2-IL-5). Herein, we show the following: 1) CD2-IL-5 and doxycycline (DOX)-induced rtTA-CC10-IL-13 mice have chronic eosinophilic and mast cell esophageal inflammation; 2) eosinophilic esophageal inflammation promotes esophageal stricture in both transgenic murine models; 3) the eosinophil-deficient ΔdblGATA/CD-2-IL-5 mice were protected from the induction of stricture, whereas the eosinophil-competent CD2-IL-5 mice develop esophageal stricture; 4) esophageal stricture is not reversible in DOX-induced rtTA-CC10-IL-13 mice (8 wk DOX followed by 8 wk no-DOX); and 5) IL-5 transgene-induced (CD2-IL-5) EoE evidences esophageal dysmotility (relaxation and contraction) that is independent of the eosinophilic esophageal inflammation: CD2-IL-5 and ΔdblGATA/CD2-IL-5 mice have comparable esophageal dysmotility. Collectively, our present study directly implicates chronic eosinophilic inflammation in the development of the esophageal structural impairments of experimental EoE.

[Functional methods of the esophagus examination].

Manometry of the esophagus is the "gold standard" in diagnosing diseases of the esophagus associated with motor disorders. The combination of manometry with impedance gives an indication of violation of bolus transport along the esophagus. High resolution manometry is new method that provides the most accurate information about the functional anatomy of the esophagus and its sphincters, as well as accurately characterizes the esophageal-gastric junction. We can increase the diagnostic value of daily pH-monitoring by analyzing communication with reflux symptoms. The combination of pH and impedance can identify different types of reflux (acid, sour, gas, liquid and mixed) in patients with symptoms of GERD and related Ahil, after gastric resection in children and infants, to evaluate the effectiveness of antireflux therapy.

Esophageal function worsens with long duration of diabetes.

BACKGROUND: The aim of this study was to assess the relationship between the duration of diabetes and esophageal dysfunction. METHODS: We examined 66 patients with type 2 diabetes. Duration of diabetes was determined by asking patients and from their medical records. The patients were divided into three groups according to the duration of their diabetes: group A, 1-4 years, n=26; group B, 5-9 years, n=20; and group C, 10+ years, n=20. Ambulatory esophageal 24-h pH and motility were monitored, and gastroesophageal reflux and esophageal motility disorders were estimated in detail. RESULTS: When the duration of diabetes was long, the percentage of time with pH<4 tended to increase. The amplitude of esophageal peristaltic waves and the frequency of effective peristalsis were reduced when the duration of diabetes was long. A significant correlation was observed between the duration of diabetes and the frequency of effective peristalsis. The number of esophageal peristaltic waves per minute and the percentage of multipeaked peristaltic waves increased significantly in group B, and decreased when the duration of diabetes became longer. CONCLUSIONS: Gastroesophageal reflux and esophageal motility disorders worsened with long duration of diabetes. These esophageal dysfunctions should be considered in patients with long-standing diabetes.

The structural characteristics and expression of neuropeptides in the esophagus of patients with congenital esophageal atresia and tracheoesophageal fistula.

PURPOSE: The aim of this study was to investigate the structural characteristics and the expression of a group of neuropeptides in the esophagus of patients with congenital esophageal atresia and tracheoesophageal fistula (EA-TEF), as well to elucidate the roles of these neuropeptides in the pathogenesis of postoperative incoordination of esophagus after successful surgical repair of EA-TEF. METHODS: Twenty-four specimens from distal tracheoesophageal fistulas of patients with EA-TEF (EA-TEF group) and 10 esophageal specimens from neonates who died of nonesophageal diseases (control group) were studied. All of the specimens were subjected to routine pathologic study, ultrastructural observation, and immunohistochemical staining for neuron-specific enolase, substance P, vasoactive intestinal polypeptide, and nitric oxide synthase. RESULTS: In the EA-TEF group, mitochondria were distributed along the membrane of smooth muscle cell, whereas mitochondria in the control group were distributed along the karyotheca of the smooth muscle cells. The ratio of granulated vesicles to clear vesicles in the varicosity of the intramuscular motor nerve ending of the EA-TEF group (0.520 +/- 0.137) was much higher than that in the control group (0.192 +/- 0.020, P < .05). The percentages of specimens shown to have positive expression of neuron-specific enolase and substance P in the EA-TEF group (20.8% and 12.5%, respectively) were significantly lower than those in the control group (90% and 80% respectively, P < .05). The percentages of specimens shown to have positive expression of vasoactive intestinal polypeptide and nitric oxide synthase in the EA-TEF group (83.3% and 75%, respectively) were significantly higher than that in the control group (30% and 10% respectively, P < .05). CONCLUSION: Imbalance of neurotransmitters excretion in nerve vesicle, abnormal intrinsic dysplasia of nerve plexus and increased expression of certain neuropeptides were the main characteristics of esophagus with abnormal intrinsic innervation, which may be responsible for the postoperative esophageal dysfunction of EA-TEF.

Effect of an aldose reductase inhibitor on esophageal dysfunction in diabetic patients.

BACKGROUND/AIMS: Disorders of the digestive tract in diabetic patients are mainly ascribed to disorders of the vagus nerve. Although aldose reductase inhibitors (ARIs) have been shown to be effective against diabetic peripheral neuropathy, their effectiveness on diabetic digestive neuropathy remains to be evaluated. The aim of the present study is to examine the effect of an ARI on the esophageal dysfunction in diabetic patients by monitoring pH and motility of the esophagus. METHODOLOGY: Eight type 2 diabetic patients with peripheral neuropathy were administered with the ARI epalrestat (150 mg/day) for 90 days, and esophageal pH and motility were monitored before and after the ARI treatment. RESULTS: Parameters related to the gastroesophageal acid reflux and the esophageal motility, such as % time of pH<4, DeMeester score, duration of the longest reflux episode, reflux episodes longer than 5 min, ratios of peristaltic waves with the amplitude greater than 25 mmHg and ratios of effective peristalsis were remarkably improved by the ARI treatment. CONCLUSIONS: Because the present study clearly demonstrated the effectiveness of an ARI on the esophageal dysfunction in diabetic patients, ARI may be useful for the treatment of diabetic digestive disorders.

Relevance of ineffective oesophageal motility during oesophageal acid clearance.

BACKGROUND: Oesophageal clearance of acid reflux consists of an initial volume clearance followed by neutralisation of the acidified mucosa by swallowed saliva (chemical clearance). Ineffective oesophageal motility (IOM), a frequent finding in patients with gastro-oesophageal reflux disease (GORD), has been claimed to underlie prolonged acid clearance by affecting oesophageal emptying and saliva transport. Intraluminal impedance allows non-radiological monitoring of movement of oesophageal liquids. AIMS: To evaluate the relevance of IOM during oesophageal volume and chemical clearance using combined pH impedance measurements. SUBJECTS: Impedance was validated with fluoroscopy to study volume clearance in three healthy subjects. Acid clearance tests were performed in 10 healthy subjects in the upright and supine positions, before and after oesophageal peristaltic disruption with sildenafil 50 mg. METHODS: After instillation of an acid bolus, simultaneous manometry, pH, and impedance were used to study oesophageal motility, chemical clearance, and volume clearance, respectively. RESULTS: Impedance allowed assessment of volume clearance accurately, showing a strong correlation with fluoroscopy (r(2)=0.89). Sildenafil provoked a graded impairment in oesophageal motility in healthy subjects without affecting saliva secretion. In the upright position, volume clearance was slightly prolonged only with severe IOM (>80% abnormal peristaltic sequences). In the supine position, severe IOM significantly prolonged chemical and volume clearance. Moderate IOM (30-80% abnormal peristalsis) had no effect. With normal peristalsis and moderate IOM, clearance times were similar in the upright and supine positions. Severe IOM however had a greater impact on clearance in the supine than in the upright position. CONCLUSION: Ineffective oesophageal motility has little effect on oesophageal clearance during upright acid reflux. With supine reflux, only severe IOM is associated with prolonged oesophageal clearance.

Influence of spastic motor disorders of the esophageal body on outcomes from laparoscopic antireflux surgery.

BACKGROUND: The clinical outcomes of laparoscopic antireflux surgery (LARS) in patients with the spectrum of nonspecific spastic esophageal motor disorders (NSSDs) are not known. METHODS: From a prospective database of patients undergoing LARS between 1997 and 2000, those with preoperative manometry at our institution and follow-up at ?6 months were identified. RESULTS: Of the 121 patients, 35 had NSSDs. There were no differences in symptoms between groups preoperatively, but in the immediate postoperative period NSSD patients had more symptoms than nonspastic patients. At 18-month mean follow-up, NSSD patients reported significantly more heartburn (22% vs 7%), waterbrash (14% vs 4%), and medication usage (17% vs 5%) than nonspastic patients (p <0.05 for each). Despite this difference, nearly all patients reported subjective improvement postoperatively, and the degree of improvement was similar between groups. CONCLUSIONS: Patients with NSSDs are more likely to have esophageal symptoms following LARS than subjects without these abnormalities. However, these patients still experience significant improvement in preoperative symptoms.

Esophageal investigations in connective tissue disease: which tests are most appropriate?

Our aim was to review the use of esophageal investigations in patients with suspected connective tissue disease (CTD). Forty-seven patients (39 women and 8 men) with suspected CTD were referred for esophageal manometry at the gastrointestinal physiology unit in the Royal Victoria Hospital, Belfast, U.K., over a 10-year period (1987-1997). The mean age was 51.7 years (range = 21-79 years). Chart review was conducted 1 to 10 years after manometry to confirm the final diagnoses: scleroderma was found in 11; CREST (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia), 8; mixed connective tissue disease, 14; Raynaud's alone, 5; and other CTDs, 9. All 47 successfully underwent esophageal manometry. In addition to manometry, 24 underwent gastroscopy; 27, barium meal; and 3, esophageal pH studies. Clinically significant esophageal abnormalities were noted in 8 (33%) on gastroscopy, in 15 (56%) on barium meal, and in 31 (66%) on manometry. Gastroscopy had a significantly lower positivity rate than the others (p < 0.05). Only three patients had pH testing, yet all three pH tests were abnormal. During manometry, abnormal findings were significantly more common in scleroderma-CREST when compared with other diagnoses (89% vs. 50%; p < 0.02). Thirty-three patients reported dysphagia. Abnormal manometry was more likely in these cases (82% vs. 33%; p < 0.02). A high percentage of patients with CTD have significant esophageal motility disorders. Investigations were more likely to be positive with scleroderma-CREST than other CTDs, even if dysphagia was present. Barium meal and manometry are more useful than OGD. pH studies were under-used. There is need for a standardized approach to esophageal investigations in patients with CTDs.

Signal transduction in esophageal and LES circular muscle contraction.

Contraction of normal esophageal circular muscle (ESO) in response to acetylcholine (ACh) is linked to M2 muscarinic receptors activating at least three intracellular phospholipases, i.e., phosphatidylcholine-specific phospholipase C (PC-PLC), phospholipase D (PLD), and the high molecular weight (85 kDa) cytosolic phospholipase A2 (cPLA2) to induce phosphatidylcholine (PC) metabolism, production of diacylglycerol (DAG) and arachidonic acid (AA), resulting in activation of a protein kinase C (PKC)-dependent pathway. In contrast, lower esophageal sphincter (LES) contraction induced by maximally effective doses of ACh is mediated by muscarinic M3 receptors, linked to pertussis toxin-insensitive GTP-binding proteins of the G(q/11) type. They activate phospholipase C, which hydrolyzes phosphatidylinositol bisphosphate (PIP2), producing inositol 1,4,5-trisphosphate (IP3) and DAG. IP3 causes release of intracellular Ca++ and formation of a Ca++-calmodulin complex, resulting in activation of myosin light chain kinase and contraction through a calmodulin-dependent pathway. Signal transduction pathways responsible for maintenance of LES tone are quite distinct from those activated during contraction in response to maximally effective doses of agonists (e.g., ACh). Resting LES tone is associated with activity of a low molecular weight (approximately 14 kDa) pancreatic-like (group 1) secreted phospholipase A2 (sPLA2) and production of arachidonic acid (AA), which is metabolized to prostaglandins and thromboxanes. These AA metabolites act on receptors linked to G-proteins to induce activation of PI- and PC-specific phospholipases, and production of second messengers. Resting LES tone is associated with submaximal PI hydrolysis resulting in submaximal levels of inositol trisphosphate (IP3-induced Ca++ release, and interaction with DAG to activate PKC. In an animal model of acute esophagitis, acid-induced inflammation alters the contractile pathway of ESO and LES. In LES circular muscle, after induction of experimental esophagitis, basal levels of PI hydrolysis are substantially reduced and intracellular Ca++ stores are functionally damaged, resulting in a reduction of resting tone. The reduction in intracellular Ca++ release causes a switch in the signal transduction pathway mediating contraction in response to ACh. In the normal LES, ACh causes release of Ca++ from intracellular stores and activation of a calmodulin-dependent pathway. After esophagitis, ACh-induced contraction depends on influx of extracellular Ca++, which is insufficient to activate calmodulin, and contraction is mediated by a PKC-dependent pathway. These changes are reproduced in normal LES cells by thapsigargin-induced depletion of Ca++ stores, suggesting that the amount of Ca++ available for release from intracellular stores defines the signal transduction pathway activated by a maximally effective dose of ACh.

The roles of excessive gastro-oesophageal reflux, disordered oesophageal motility and decreased mucosal sensitivity in the pathogenesis of Barrett's oesophagus.

Barrett's oesophagus is often considered an end stage of gastro-oesophageal reflux disease. In its pathogenesis increased oesophageal acid exposure, disturbed oesophageal motility and decreased oesophageal mucosal sensitivity are thought to be of importance. In this review the role of each of these factors will be discussed and an update of the recent literature will be given.

The value of 24-hour combined esophageal pressure and pH recording in the detection of esophageal function abnormalities.

Gastroesophageal reflux and esophageal motor abnormalities are suspected of being the source of chest pain when a cardiac origin of the pain has been excluded. Because of the usually intermittent character of the motility disturbances, short conventional manometry, with or without provocation tests, often fails to establish the diagnosis. Therefore, 24-h esophageal pressure and pH recording was developed and has been proposed as a diagnostic tool in the study of patients who suffer from intermittent substernal pain. In this paper the value of 24-h combined esophageal pressure and pH recording in detecting disordered esophageal function in noncardiac chest pain and other esophageal disorders is discussed.