Search

Objective: Our aim was to evaluate the association between visceral hypersensitivity and GI symptom severity in large cohorts of patients with functional GI disorder (FGID) and to adjust for psychological factors and general tendency to report symptoms., Design: We included five cohorts of patients with FGIDs (IBS or functional dyspepsia; n=1144), who had undergone visceral sensitivity testing using balloon distensions (gastric fundus, descending colon or rectum) and completed questionnaires to assess GI symptom severity, non-GI somatic symptoms, anxiety and depression. Subjects were divided into sensitivity tertiles based on pain/discomfort thresholds. GI symptom severity was compared between sensitivity tertiles in each cohort and corrected for somatisation, and anxiety and depression., Results: In all five cohorts, GI symptom severity increased gradually with increasing visceral sensitivity, with significant differences in GI symptom severity between the sensitivity tertiles (p<0.0001), with small to medium effect sizes (partial η 2 : 0.047-0.11). The differences between sensitivity tertiles remained significant in all cohorts after correction for anxiety and depression, and also after correction for non-GI somatic symptom reporting in all of the cohorts (p<0.05)., Conclusions: A gradual increase in GI symptom severity with increasing GI sensitivity was demonstrated in IBS and functional dyspepsia, which was consistent across several large patient groups from different countries, different methods to assess sensitivity and assessments in different parts of the GI tract. This association was independent of tendency to report symptoms or anxiety/depression comorbidity. These findings confirm that visceral hypersensitivity is a contributor to GI symptom generation in FGIDs., Competing Interests: Competing interests: MS has received unrestricted research grants from Danone, and Ferring Pharmaceuticals, and served as a Consultant/Advisory Board member for AstraZeneca, Danone, Nestlé, Chr Hansen, Almirall, Allergan, Albireo, Glycom and Shire, and as a speaker for Tillotts, Takeda, Shire and Almirall. HT has served as Consultant/Advisory Board member for Almirall, Danone and Shire. MALvT has obtained research support from Takeda for investigator initiated study. OSP has received salary support from a research grants from Takeda Pharmaceuticals and Salix Pharmaceuticals and from a consulting agreement with Ironwood Pharmaceuticals and an educational grant provided by Takeda Pharmaceuticals, and received a speaker honorarium in an educational programme supported by Ironwood Pharmaceuticals and Takeda Pharmaceuticals. JT has given scientific advice to Almirall, AstraZeneca, Danone, Menarini, Novartis, Nycomed, Ocera, Ono pharma, Shire, SK Life Sciences, Theravance, Tranzyme, Xenoport, and Zeria Pharmaceuticals, and has been member of the Speaker bureau for: Abbott, Almirall, AlfaWasserman, AstraZeneca, Janssen, Menarini, Novartis, Nycomed, Shire, Zeria. WEW received research grants from Takeda, Ironwood, Salix, and the Rome Foundation; served as a consultant to Biomerica USA, Ono Pharmaceuticals and Ferring; and received unrestricted educational grants from Takeda and Ferring., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Background: Tacr2 is one of the G protein-coupled receptors(GPCRs) that mediate the biological actions of tachykinins. It is abundantly expressed in the gastrointestinal (GI) system and is thought to play an important role in GI motility, secretion, and visceral sensitivity. Previously, the physiological and pathophysiological functions of Tacr2 were mainly studied using Tacr2 selective agonists or antagonists. Here, we seek to investigate the effect of Tacr2 disruption in mice to provide further insights., Methods: The Tacr2 knockout mice were generated by homologous recombination and the phenotypic changes of the Tacr2-null mice were analyzed and compared with their wild type (wt) littermates., Key Results: Increased food retention was detected in Tacr2 -/- mice. The stomach of Tacr2 -/- mice had thinner muscularis externa and less neurons in the myenteric plexus. The stomach and small intestine exhibited longer duration of electrical field stimulation (EFS)-induced inhibition in the gastric fundus and decreased frequency of migrating motor complex (MMC), respectively. Neuronal nitric oxide synthase (nNOS) and vasoactive intestinal polypeptide (VIP) were significantly up-regulated due to Tarc2 deficiency, contributing to enhanced nitric oxide (NO) signaling in the stomach of Tacr2 -/- mice. Intraperitoneal application of 7-nitroindazole (7-NI) to Tacr2 -/- mice effectively relieved the gastric emptying disturbance. Moreover, Creb and NF-κB signalings were involved in the regulation of these physiological changes initiated by Tacr2 deficiency., Conclusions & Inferences: Tacr2 negatively regulated the expression of nNOS and VIP both in vivo and in vitro. Its ablation in mice elevated the expression of nNOS and VIP, enhanced NO signaling and changed the Creb and NF-κB signalings, finally leading to the gastric emptying disturbance of Tacr2 -/- mice., (© 2017 John Wiley & Sons Ltd.)

Gastroesophageal reflux disease is a common disorder in humans and has been treated for the last 67 years using fundoplication. However, treatment results have generally not been satisfactory. Physiological and anatomic findings must be taken into account to improve the therapy technique. In this article, these are described using the example of paradoxical sphincters and the effect of NO signal molecules in the gastrointestinal tract.

Background: Psychological stress has been shown to impair gastric accommodation (GA), but its mechanism has not been elucidated. This study was conducted to clarify the role of 5-HT2B receptors in a guinea pig model of stress-induced impairment of GA., Methods: Gastric accommodation was evaluated by measuring the intrabag pressure in the proximal stomach after administration of a liquid meal. The guinea pigs were subjected to water-avoidance stress. The role of 5-HT2B receptors in impairment of GA was investigated by administering a 5-HT2B receptor agonist (BW723C86) or antagonist (SB215505), the traditional Japanese medicine rikkunshito (RKT), a muscarinic M3 receptor antagonist (1,1-dimethyl-4-diphenylacetoxypiperidium iodide [4-DAMP]), or a nitric oxide synthase inhibitor (Nω -nitro-L-arginine [L-NNA])., Key Results: In normal animals, liquid meal-induced GA was inhibited by BW723C86, but was not affected by SB215505. The inhibition of GA by BW723C86 was reversed by co-administration of 4-DAMP. Compared to normal animals, GA in stressed animals was significantly inhibited. SB215505 and RKT significantly suppressed stress-induced impairment of GA. After meal administration, the level of cyclic guanosine monophosphate in gastric fundus tissue increased by approximately twofold in normal animals, but did not change in stressed animals. The inhibition of GA by L-NNA was suppressed by SB215505 or RKT. At a dose that did not affect GA in normal animals, BW723C86 exacerbated the impairment of GA in stressed animals., Conclusions and Inferences: Stress-induced impairment of GA may be mediated by an increased responsiveness of 5-HT2B receptors, and activation of the 5-HT2B receptor signaling pathway may have an inhibitory effect on nitric oxide function., (© 2016 The Authors. Neurogastroenterology & Motility published by John Wiley & Sons Ltd.)

Gastric hypersensitivity is one of the key contributors to the postprandial symptoms of epigastric pain/discomfort, satiety, and fullness in functional dyspepsia patients. Epidemiological studies found that adverse early-life experiences are risk factors for the development of gastric hypersensitivity. Preclinical studies found that neonatal colon inflammation elevates plasma norepinephrine (NE), which upregulates expression of nerve growth factor (NGF) in the muscularis externa of the gastric fundus. Our goal was to investigate the cellular mechanisms by which NE upregulates the expression of NGF in gastric hypersensitive (GHS) rats, which were subjected previously to neonatal colon inflammation. Neonatal colon inflammation upregulated NGF protein, but not mRNA, in the gastric fundus of GHS rats. Western blotting showed upregulation of p110γ of phosphatidylinositol 4,5-bisphosphate 3-kinase (PI3K), phosphoinositide-dependent kinase-1 (PDK1), pAKT(Ser473), and phosphorylated 4E-binding protein (p4E-BP1)(Thr70), suggesting AKT activation and enhanced NGF protein translation. AKT inhibitor MK-2206 blocked the upregulation of NGF in the fundus of GHS rats. Matrix metalloproteinase 9 (MMP-9), the major NGF-degrading protease, was suppressed, indicating that NGF degradation was impeded. Incubation of fundus muscularis externa with NE upregulated NGF by modulating the protein translation and degradation pathways. Yohimbine, an α2-adrenergic receptor antagonist, upregulated plasma NE and NGF expression by activating the protein translation and degradation pathways in naive rats. In contrast, a cocktail of adrenergic receptor antagonists suppressed the upregulation of NGF by blocking the activation of the protein translation and degradation pathways. Our findings provide evidence that the elevation of plasma NE induces NGF expression in the gastric fundus., (Copyright © 2016 the American Physiological Society.)

Objective: Impaired gastric accommodation is reported in patients with functional dyspepsia (FD). Previous findings in postinfectious patients with FD suggest that low-grade inflammation and dysfunction of nitrergic nerves play a role in impaired accommodation. To date, spontaneous animal models to study the relationship between these changes are lacking. We hypothesise that the normoglycaemic BioBreeding diabetes-prone (BB-DP) rat provides an animal model of inflammation-induced impaired gastric motor function., Design: Control diabetes-resistant biobreeding, normoglycaemic and hyperglycaemic BB-DP rats were sacrificed at the age of 30, 70 and 220 days and gastric fundus tissue was harvested to study nitrergic motor control, inflammation and expression of neuronal isoform of nitric oxide synthase (nNOS) and inducible isoform of nitric oxide synthase (iNOS). Nutrient-induced changes in intragastric pressure (IGP) were measured in normoglycaemic BB-DP rats to study accommodation., Results: No differences in nitrergic function and inflammation were observed between BB-DP and control rats at 30 days. The nitrergic component of the fundic muscle relaxation was reduced in BB-DP rats of 70 and 220 days. This was accompanied by a significant loss of nNOS proteins. IGP significantly increased during nutrient infusion in BB-DP rats of 220 days, indicating impaired accommodation. Infiltration of polymorphonuclear cells, increased myeloperoxidase activity and increased expression of iNOS was observed in the fundic mucosa and muscularis propria of 70-day-old and 220-day-old BB-DP rats., Conclusions: BB-DP rats of 220 days display altered fundic motor control and impaired accommodation, which is least partially explained by loss of nitrergic function. This may be related to inflammatory changes in the neuromuscular layer, suggesting that normoglycaemic BB-DP rats provide a spontaneous model for inflammation-induced impaired gastric accommodation., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Nitric oxide molecules serve as neurotransmitters to relax smooth muscle tension in many parts of the body. In humans and other mammals they play an important role for correct smooth muscle function in unusual locations. We previously described this mechanism (Stelzner, Chirurg. doi:10.1007/s00104-014-2777-z, 2014) using the occlusive mechanism of the upper and lower esophageal sphincters as an example. Cells producing nitric oxide can be found in the gastric fundus, the anorectal continence organ, vesicourethraltract and also in the uterine cervix in the final trimester of pregnancy. In all these locations they serve as elements of anatomical sphincter structures that have a paradoxical function. These observations confirm the points made in the introduction of this article on the stretch sphincter mechanism of the lower esophageal sphincter and the treatment of gastroesophageal reflux disease by retensioning of the esophagus in the diaphragmatic hiatus. In particular, high-resolution esophageal manometry of the lower esophageal sphincter can easily detect every functional disturbance caused by gastric plication and such changes were to be expected based on what we described in articles I and II.

Esophageal atresia (EA) is characterized by esophageal and gastric motility changes secondary to developmental and postsurgical damage. This study evaluated the in vitro contractile profile of the distal esophagus and gastric fundus in an experimental model of EA induced by doxorubicin (DOXO). Wistar pregnant rats received DOXO 2.2 mg/kg on the 8th and 9th gestational days. On day 21.5, fetuses were collected, sacrificed, and divided into groups: control, DOXO without EA (DOXO-EA), and DOXO with EA (DOXO+EA). Strips from the distal esophagus and gastric fundus were mounted on a wire myograph and isolated organ-bath system, respectively, and subjected to increasing concentrations of carbamylcholine chloride (carbachol, CCh). The isolated esophagus was also stimulated with increasing concentrations of KCl. In esophagus, the concentration-effect curves were reduced in response to CCh in the DOXO+EA and DOXO-EA groups compared to the control group (P<0.05). The maximum effect values (Emax) for DOXO+EA and DOXO-EA were significantly lower than control (P<0.05), but the half-maximal effective concentration (EC50) values were not significantly different when the three groups were compared (P>0.05). In response to KCl, the distal esophagus samples in the three groups were not statistically different with regard to Emax or EC50 values (P>0.05). No significant difference was noted for EC50 or Emax values in fundic strips stimulated with CCh (P>0.05). In conclusion, exposure of dams to DOXO during gestation inhibited the contractile behavior of esophageal strips from offspring in response to CCh but not KCl, regardless of EA induction. The gastric fundus of DOXO-exposed offspring did not have altered contractile responsiveness to cholinergic stimulation.

Nausea is the subjective unpleasant sensation that immediately precedes vomiting. Studies using barostats suggest that gastric fundus and lower esophageal sphincter (LES) relaxation precede vomiting. Unlike barostat, high-resolution manometry allows less invasive, detailed measurements of fundus pressure (FP) and axial movement of the gastroesophageal junction (GEJ). Nausea was induced in 12 healthy volunteers by a motion video and rated on a visual analog scale. FP was measured as the mean value of the five pressure channels that were clearly positioned below the LES. After intubation, a baseline (BL) recording of 15 min was obtained. This was followed by presentation of the motion video (at least 10 min, maximum 20 min) followed by 30 min recovery recording. Throughout the experiment we recorded autonomic nervous system (ANS) parameters [blood pressure, heart rate (HR), and cardiac vagal tone (CVT), which reflects efferent vagal activity]. Ten out of 12 subjects showed a drop in FP during peak nausea compared with BL (-4.0 ± 0.8 mmHg; P = 0.005), and 8/10 subjects showed a drop in LES pressure (-8.8 ± 2.5 mmHg; P = 0.04). Peak nausea preceded peak fundus and LES pressure drop. Nausea was associated with configuration changes at the GEJ such as LES shortening and esophageal lengthening. During nausea we observed a significantly increased HR and decreased CVT. In conclusion, nausea is associated with a drop in fundus and LES pressure, configuration changes at the GEJ as well as changes in the ANS activity such as an increased sympathetic tone (increased HR) and decreased parasympathetic tone (decreased CVT).

Background and Aim: Patients with gastroesophageal reflux disease (GERD) are often advised to avoid large meals, based on their complaints of increased symptoms after eating too much, and epidemiological evidence of a link between high volume intake and the presence of GERD. However, the precise effects of meal volume on gastroesophageal reflux have not been well studied. We aimed to clarify the effect of meal volume on acid regurgitation and symptoms in patients with GERD., Methods: Fifteen patients (10 female, 5 male; mean 54 ± 10 years old) with GERD were studied twice each in random order, during 24 h ambulatory pH monitoring. On one day, they consumed a 600 mL liquid test meal three times (breakfast, lunch, and dinner), and on the other, they consumed a 300 mL test meal six times (breakfast, snack, lunch, snack, dinner, and snack). Gastric fundus and antral areas and antral contractions were measured by transabdominal ultrasound. Symptoms were recorded using questionnaires., Results: During the 600 mL regimen, there were more reflux episodes (17 ± 4 vs 10 ± 2, P = 0.03) and a greater total acid reflux time (12.5 ± 5.9% vs 5.5 ± 3.6%; P = 0.045) than the 300 mL regimen. Both the cross-sectional area of the gastric fundus (P = 0.024) and the number of antral contractions (P = 0.014) were greater for the 600 mL regimen., Conclusions: Larger meals are associated with distension of the gastric fundus and an increase in gastroesophageal reflux when compared with smaller, more frequent meals.

Background/objectives: Embolization of the left gastric artery (LGA), which preferentially supplies the gastric fundus, has been shown to produce weight loss in animal models. However, weight loss after LGA embolization in humans has not been previously established. The aim of this study was to evaluate postprocedural weight loss in patients following LGA embolization., Subjects/methods: A retrospective analysis of the medical records of patients who underwent LGA embolization for upper gastrointestinal (GI) bleeding was performed. Postprocedural weight loss in this group was compared to a control group of patients who had undergone embolization of other arteries for upper GI bleeding., Results: The experimental group (N = 19) lost an average of 7.3% of their initial body weight within three months of LGA embolization, which was significantly greater than the 2% weight loss observed in the control group (N = 28) (P = 0.006). No significant differences were seen between the groups in preprocedural body mass index (BMI), age, postprocedural care in the intensive care unit, history of malignancy, serum creatinine, or left ventricular ejection fraction., Conclusions: The current data suggest that body weight in humans may be modulated via LGA embolization. Continued research is warranted with prospective studies to further investigate this phenomenon.

The researchers are investigated in 32 white male, rats by means of electron-microscopic methods and morphometric analysis. The sharp reduction acid produceds functions parietal hutches after total colonectomy, her (its) stability at early periods after operation are certainly conditioned inflammatory-distrofic change on the part of secretory membranes, and particularly mitochondria of the device.

Background: Bariatric surgery is the most effective treatment for gastro-esophageal reflux disease (GERD) in obese patients, with the Roux-en-Y gastric bypass being the technique preferred by many surgeons. Published data reporting the results of laparoscopic sleeve gastrectomy (LSG) in patients with GERD are contradictory. In a previous observational study, we found that relative narrowing of the distal sleeve, hiatal hernia (HH), and dilation of the fundus predispose to GERD after LSG. In this study, we evaluated the effects of standardization of our LSG technique on the incidence of postoperative symptoms of GERD., Methods: This was a concurrent cohort study. Patients who underwent bariatric surgery at our center were followed prospectively. LSG was performed in all patients in this series., Results: A total of 234 patients underwent surgery. There were no cases of death, fistula, or conversion to open surgery. All 134 patients who completed 6-12 months of postoperative follow-up were evaluated. Excess weight loss at 1 year was 73.5%. In the study group, 66 patients (49.2%) were diagnosed with GERD preoperatively, and HH was detected in 34 patients (25.3%) intraoperatively. HH was treated by reduction in three patients, anterior repair in 28, and posterior repair in three. Only two patients (1.5%) had symptoms of GERD at 6-12 months postoperatively., Conclusions: Our results confirm that careful attention to surgical technique can result in significantly reduced occurrence of symptoms of GERD up to 12 months postoperatively, compared with previous reports of LSG in the literature.

Gastric involvement appears quite commonly in systemic sclerosis (SSc). The aim of this study was to evaluate gastric wall motility using ultrasonography, a noninvasive method able to track both filling and emptying of fundus and antrum. The study was performed in 20 SSc patients and 20 healthy control subjects. Gastric filling and emptying were evaluated by transabdominal ultrasonography, measuring changes in fundus and antral areas over a 1-h period after ingestion of a liquid bolus (500 ml of mineral water). Areas of both gastric fundus and antrum at basal evaluation were found to be smaller in SSc patients than in healthy controls. Gastric filling was significantly reduced after ingestion of liquid bolus. Gastric emptying was delayed both in fundus and antrum. No significant differences of gastric wall motility have been observed in different subsets of SSc patients. Our findings show that gastric dysmotility is frequent and severe in SSc patients, contributing to the gastrointestinal disturbances which are very common in this disease.

Gastric carcinoid tumors comprise 7% of all gastrointestinal carcinoids and have significantly increased in incidence over the past few decades. Seventy to 80% of gastric carcinoids are type I, which usually are clinically asymptomatic and found incidentally at endoscopic evaluation for abdominal pain or anemia. In this review, advances in understanding the pathophysiology of type I gastric carcinoid are highlighted. In addition, various current diagnostic and treatment options are discussed. Although type I carcinoids generally hold a benign course, rigorous investigation is needed to ensure accurate diagnosis and optimal treatment. This includes appropriate diagnostic procedures and imaging and accurate staging of tumor. Tumor size, depth of invasion, presence of metastasis, and the tumor's gastrin dependency dictate treatment options. Appropriate treatments can consist of endoscopic resection, antrectomy, medical management, or frequent follow-up. This article provides a systematic method of evaluating and treating type I gastric carcinoid.

Background: In order to know the role of gastric emptying in the mechanism of weight loss and early satiety after a restrictive surgical procedure for treatment of morbid obesity, a consecutive series of patients were scintigraphically investigated before and after laparoscopic adjustable gastric banding., Methods: Sixteen patients undergoing laparoscopic adjustable gastric banding underwent preoperatively, and at 6 months postoperatively, a gastric emptying study (solid meal and single isotope). Esophageal retention time, lag phase, peak activity time, gastric emptying rate, fundus emptying rate, and weight loss were recorded. Upper GI symptom assessment was carried out by using a standardized questionnaire. Gastric emptying parameters were correlated with the upper GI symptoms., Results: Gastric band placement showed no significant influence on postoperative gastric emptying rate [median % (interquartile range): 42 (23.3-59) preoperatively vs 38 (31-71) postoperatively and fundus emptying rate: 59(37-91) preoperatively vs 70 (53-89) postoperatively]; however, an increase in early satiety was found. Neither gastric emptying rate nor fundus emptying rate showed a relation with early satiety or weight loss. Furthermore, no correlation was found between early satiety and lag phase, esophageal retention time, start of activity, and peak activity time in proximal stomach., Conclusion: Laparoscopic adjustable gastric banding seems not to affect gastric emptying. Neither a relation between postoperative gastric emptying rate and weight loss nor between early satiety and weight loss was found. Therefore, it is unlikely that gastric emptying plays a role in the mechanism of weight loss following laparoscopic adjustable gastric banding.

Background & Aims: Gastrointestinal stromal tumors (GISTs) express the receptor tyrosine kinase c-kit. Approximately 90% of GISTs have gain-of-function mutations in the Kit gene, which leads to its constitutive activation and drives malignant behavior of GISTs. Interstitial cells of Cajal (ICC) express c-kit; however, it is unknown whether uncontrolled hyperplasia of ICC is responsible for GISTs. Here, we sought to determine whether gain-of-function mutations in Kit lead to hyperplasia of all classes of ICC, whether ICC hyperplasia begins before birth, and whether functional defects occur in ICC hyperplasia or the development of GISTs., Methods: Heterozygous mutant Kit(V558Delta)/+ mice that develop symptoms of human familial GISTs and prematurely die from pathology of the gastrointestinal tract were utilized and compared with wild-type controls. C-kit-immunohistochemistry and intracellular electrical recording of spontaneous and nerve-evoked activity were applied to examine the density and functionality of ICC in these mutants., Results: There was considerable hyperplasia in all classes of ICC throughout the GI tract of Kit(V558Delta)/+ mice, except for ICC in the deep muscular plexus of the intestine. Spontaneous electrical activity and postjunctional neural responses in hyperplastic ICC tissues appeared normal but were up-regulated in the cecum, where GISTs were commonly found., Conclusions: Kit gain-of-function leads to hyperplasia of most classes of ICC throughout the GI tract. ICC retain normal pacemaker function and enteric neural responses well after development of hyperplasia.

Gastrointestinal prokinetics are a heterogeneous class of drugs that stimulate smooth muscle contractions to enhance gastric emptying and intestinal transit. Recently studied prokinetics include antidopaminergic agents (itopride), serotonergic agents (tegaserod and others), and motilin receptor agonists and ghrelin receptor agonists (mitemcinal, TZP101). It has been difficult to establish symptomatic benefit with prokinetic drugs in gastroparesis and functional dyspepsia, because of pathophysiological heterogeneity of the patient populations, a lack of well-accepted endpoints, and inconsistent relationships between changes in motor function and symptomatic outcome. Fundic relaxant drugs are a recent different approach to treatment of gastric motility disorders. Recently studied drugs include drugs under investigation including nitrates, serotonin reuptake blockers, 5-HT(1A) receptor agonists (buspirone and R137696), and muscarinc M1/M2 receptor antagonists (acotiamide or Z-338).

Objective: The primary aim of this study was to test the widespread assumption that the viability of the gastric fundus is compromised by fundoplication, thereby limiting the use of stomach to reconstruct the upper gastrointestinal tract after esophageal resection., Methods: Between February 1991 and February 2006, a consecutive series of 142 patients with esophageal adenocarcinoma (EADC) underwent esophageal resection. To reconstruct the upper gastrointestinal tract, all patients had a narrow gastric tube (greater curvature of stomach based on the right gastroepiploic artery) transposed through the posterior mediastinum to the left neck where an anastomosis to the cervical esophagus was performed. From a prospective database, 15 patients were identified to have undergone an 'open' fundoplication (transabdominal Nissen, n=11; transthoracic Belsey, n=4) from 12 to 23 years earlier. Outcomes were compared between patients with EADC who had undergone previous fundoplication, and patients with EADC who never had antireflux surgery., Results: Gastric transposition and cervical esophagogastrostomy were technically feasible in all patients. No significant differences in outcome were found between patient groups. Gastric necrosis developed in only one patient, who had not undergone previous fundoplication. Anastomotic leak rates after esophageal resection and reconstruction were not statistically different based on whether patients had undergone previous fundoplication (2/15, 13.3%) or not (16/127, 12.6%; p=0.99)., Conclusions: With careful attention to surgical technique, previous fundoplication does not preclude the use of stomach to reconstruct the foregut after esophageal resection, refuting the notion that previous antireflux surgery is a relative contraindication to, or alters the approach to esophageal cancer surgery.

Background: Recently, non-invasive techniques such as 3 dimensional ultrasonography (3DUS) have been developed to assess gastric wall characteristics and to investigate their relationship with upper gastrointestinal sensations. To date, no head-to-head comparison has been carried out between the barostat and the 3DUS technique., Aim: To compare barostat and 3DUS and to investigate the relationship between gastric volumes and sensations in patients with functional dyspepsia and in healthy subjects., Patients and Methods: Gastric accommodation was studied in 15 patients with functional dyspepsia and in 15 healthy subjects after ingestion of a liquid nutrient (300 kcal) using barostat and 3DUS in random order for 60 min. Proximal gastric relaxation was measured using barostat and gastric volume using 3DUS. Change in gastric volume, acquired by 3DUS, was expressed as total gastric volume/proximal volume ratio (TGV/PV) and compared with changes in barostat volume (fundal accommodation)., Results: Patients with functional dyspepsia showed a smaller change in proximal gastric volume than healthy subjects using barostat (mean (SD) 82 (61) v 205 (79) ml, p<0.01) and 3DUS (118 (41) v 199 (39) ml, p<0.01). Dysaccommodation of the proximal stomach was observed in 7 of 15 (46%) patients using the barostat technique. 10 of 15 (67%) patients were found to have an abnormal change in proximal gastric volume using TGV/PV ratio. At 5 min postprandially, fullness was related to the change in distal gastric volume (r = 0.51, p = 0.006) in the 3DUS study, whereas no relationship was observed in the barostat study., Conclusion: 3DUS is a feasible non-invasive technique to measure gastric volumes and shows a distinct overlap with barostat data in healthy subjects and patients with functional dyspepsia. Fullness relates to distal gastric volumes when assessed by non-invasive 3DUS.

Background and Aims: In a subset of functional dyspepsia patients, we have recently described the association between unsuppressed postprandial phasic contractions of the proximal stomach and a specific symptom pattern. To better elucidate the role of phasic contractility of the proximal stomach in symptom generation, we aimed at inducing this motility pattern in healthy volunteers and we carefully monitored symptom onset., Patients and Methods: Eleven healthy volunteers underwent gastric barostat on two separate days. Gastric tone and phasic contractility were evaluated for a 90-minute period. In particular, after 30 min of basal recording, a caloric liquid meal and neostigmine 0.5 mg IV or saline in a double-blind, randomized, crossover protocol were administered. During the measurement, severity of 9 dyspeptic symptoms was evaluated on a visual analog scale. Computer-aided baseline reconstruction allowed us to quantify phasic contractions as a motility index (MI), reflecting the area between signal and baseline normalized over time. Perception of contractions after placebo or neostigmine was evaluated. Moreover, we tested for influence of gastric tone and phasic contractility on symptoms., Results: After neostigmine, gastric accommodation was not different than after placebo (225 +/- 36 vs 206 +/- 76 mL, P= NS). During the first 30-min postprandial period, the MI was significantly higher after neostigmine than after placebo (26.4 +/- 3 vs 21.4 +/- 3, P < 0.001), confirming the induction of unsuppressed postprandial phasic contractions. The postprandial total symptom score was significantly higher after neostigmine compared to saline; several individual postprandial symptom scores were also significantly higher after neostigmine-compared placebo. After neostigmine, a higher percentage of postprandial contractions was perceived compared to placebo., Conclusions: Unsuppressed postprandial phasic contractility of the proximal stomach is a mechanism potentially involved in the pathogenesis of dyspeptic symptoms.

Background: Implantable gastric stimulation (IGS) has been proposed for treating obesity. The aim of this study was to investigate the effects of temporary mucosal electrical stimulation on water and food intake as well as gastric emptying in healthy humans., Methods: The study was designed to study the effects of temporary gastric electrical stimulation (GES) on symptoms, gastric accommodation, food intake, and gastric emptying. It was performed in 12 healthy volunteers on 3 consecutive days. GES was performed using mucosal electrodes endoscopically placed in the fundus., Results: The amount of maximum water intake was reduced with GES (894 +/- 326 mL) compared with sham-GES (1,093 +/- 417 mL, p = 0.01). The food intake was also reduced with GES (p = 0.012). In comparison with sham stimulation, GES delayed gastric emptying during the first 45 min after the meal but not during the remaining time. GES with parameters effective in reducing water and food intake and delaying gastric emptying did not induce significant dyspeptic symptoms, compared with sham stimulation., Conclusions: GES using temporary mucosal electrodes decreases food intake as well as maximum intake of water, and has a tendency of delaying gastric emptying. It may have a potential application for the treatment of obesity.

Objectives: This study aimed to assess the effects of Belsey Mark IV 270 degrees (partial) and Nissen 360 degrees (complete) fundoplication on proximal stomach function, transient lower esophageal sphincter relaxation (TLESR) elicitation and the esophagogastric junction (EGJ) pressure profile during TLESR to further elucidate the mechanism of action of fundoplication., Methods: Ten patients after partial and 10 patients after complete fundoplication were studied. High-resolution EGJ manometry and pH recording were performed for 1 h at baseline and 2 h following meal ingestion (500 mL/300 kcal). Three dimensional (3D) ultrasonographic images of the stomach were acquired every 15 min after meal ingestion. From the 3D ultrasonographic images, proximal gastric volumes were computed., Results: Postprandial proximal to complete gastric volume distribution ratios were larger among patients after partial (0.42 +/- 0.028) compared with patients after complete fundoplication (0.37 +/- 0.035; p < 0.05). Partial fundoplication patients had a markedly greater postprandial rate of TLESR (1.7 +/- 0.3/h) than patients after complete fundoplication (0.8 +/- 0.2/h; p < 0.05). The axial EGJ pressure profile was minimally affected by partial fundoplication but instead markedly changed after complete fundoplication., Conclusions: Patients after partial fundoplication exhibit a larger meal-induced increase in proximal stomach volume, a higher TLESR rate, and a minimally affected axial EGJ pressure profile compared to patients after complete fundoplication.

Background and Aims: Achalasia is a disease of unknown aetiology. An immune mechanism has been suggested on the basis of previous morphological observations. The objective of this study was to test whether the serum of achalasia patients could reproduce the phenotype and functional changes that occur with disease progression in an ex vivo human model., Methods: Specimens of normal human fundus were maintained in culture in the presence of serum from patients with achalasia, gastro-oesophageal reflux disease (GORD), or healthy subjects (controls). Immunohistochemical detection of choline acetyltransferase (ChAT), neurone specific enolase (NSE), vasoactive intestinal polypeptide (VIP), nitric oxide synthase (NOS), and substance P was carried out in whole mounts of gastric fundus myenteric plexus. In addition, the effects of achalasia serum on electrical field stimulation (EFS) induced contractions were measured in circular muscle preparations., Results: Serum from achalasia patients did not affect the number of myenteric neurones. Tissues incubated with serum from achalasia patients showed a decrease in the proportion of NOS (-26% of NSE positive neurones; p=0.016) and VIP (-54%; p=0.09) neurones, and a concomitant increase in ChAT neurones (+16%; p<0.001) compared with controls. In contrast, GORD serum did not modify the phenotype of myenteric neurones. Area under the curve of EFS induced relaxations (abolished by N-nitro-L-arginine methyl ester) was significantly decreased following incubation with serum from achalasia patients compared with controls (-7.6 (2.6) v -14.5 (5.0); p=0.036)., Conclusions: Serum from achalasia patients can induce phenotypic and functional changes which reproduce the characteristics of the disease. Further identification of putative seric factors and mechanisms involved could lead to the development of novel diagnostic and/or therapeutic strategies in achalasia.

Background: In patients with functional dyspepsia (FD), tolerance to gastric fundus distension is frequently compromised. We tested the contribution of contractile cholinergic or relaxing nitrergic pathways in this disorder., Methods: Thirty-nine patients (29 women, 10 men) with FD participated in this study. Gastric distension studies where carried out by inflating a fundic balloon until the maximum distension volume (MDV) tolerated by the patient. Gastric distension was first evaluated in basal control conditions before repeating the test after the injection of anticholinergic hyoscine (Buscopan 20 mg intravenous) or following the administration of nitric oxide donor nitroglycerin (Nitrolingual 1.2 mg sublingual)., Results: MDVs were significantly (P<0.01) lower in FD patients (495+/-27 ml) than in controls (995+/-59 ml). Intolerance to fundic distension was found in 77% of dyspepsia patients. Hyoscine improved the threshold for discomfort (343+/-21 versus 421+/-43 ml; P<0.05), as well as the MDV (510+/-36 versus 635+/-44 ml; P<0.01). This drug effect was seen in 71% (10/14) of patients. Nitroglycerin failed to modify thresholds. However, improved tolerance was seen in 15% (2/13) of the patients., Conclusion: Intolerance to fundic distension is a frequent finding in FD (77% patients). The cholinergic pathway seems to be a predominant factor involved in tolerance to distension in patients with FD. Fundus-relaxing drugs should be considered for the treatment of dyspepsia.

The contractile response of the stomach fundus to endothelin-1 (ET-1) was examined in streptozotocin (STZ)-induced diabetic rats. In STZ-diabetic rats (versus age-matched control rats) (a) ET-1 caused a longer-lasting contraction of stomach fundus strips, and (b) in the dose-response curve, the ET-1-induced contraction was significantly greater for a given concentration (3 x 10(-7) to 10(-7) M). Although repeated application of ET-1 led to desensitization, the desensitization was less pronounced in STZ-diabetic rats than in the controls. The density of the binding sites for [(125)I]-ET-1 was increased in the diabetic stomach fundus (versus the controls), but Kd values were similar between the two groups. The ET(B) receptor mRNA expression level was significantly increased in the diabetic stomach fundus. These results suggest that the diabetes-related enhancement of the ET-1-induced contraction of the stomach fundus may be due to an increase in the ET(B) receptor population.

Urinary bladder augmentation with a segment of the stomach, i.e., gastrocystoplasty, has been used to improve capacity and compliance in patients with bladder dysfunction. In the present study, rats were subjected to gastrocystoplasty (using the oxyntic segment) with or without fundectomy (removal of the oxyntic part of stomach), and the acid secretion in the augmented bladder was measured. In freely fed rats, the pH values were neutral and not significantly decreased in the rats subjected to gastrocystoplasty with or without fundectomy compared to controls (no operation or sham operation). In response to food intake after being fasted, the rats subjected to gastocystoplasty + fundectomy produced significant amounts of acid. Immunohistochemical examination revealed that the ECL cells and parietal cells seemed to be normal in rats with gastrocystoplasty alone, and that micronodules of ECL appeared to develop in rats with gastrocystoplasty + fundectomy. We suggest that the rats subjected to gastrocystoplasty + fundectomy are capable of producing acid secretion in the bladder, probably due to the secretagogue and trophic effects of gastrin on the ECL cells in the segment of the oxyntic mucosal segment of the bladder.

Visceral hypersensitivity in gastric fundus is a possible pathogenesis for functional dyspepsia. The cortical representation of gastric fundus is still unclear. Growing evidence shows that the insula, but not the primary or secondary somatosensory region (SI or SII), may be the cortical target for visceral pain. Animal studies have also demonstrated that amygdala plays an important role in processing visceral pain. We used fMRI to study central projection of stomach pain from fundus balloon distension. We also tested the hypothesis that there will be neither S1 nor S2 activation, but amygdala activation with the fundus distension. A 3T-fMRI was performed on 10 healthy subjects during baseline, fullness (12.7 +/- 0.6 mmHg) and moderate gastric pain (17.0 +/- 0.8 mmHg). fMRI signal was modelled by convolving the predetermined psychophysical response. Statistical comparisons were performed between conditions on a group level. Gastric pain activated a wide range of cortical and subcortical structures, including thalamus and insula, anterior and posterior cingulate cortices, basal ganglia, caudate nuclei, amygdala, brain stem, cerebellum and prefrontal cortex (P < 0.001). A subset of these neuronal substrates was engaged in the central processing of fullness sensation. SI and SII were not activated during the fundus stimulation. In conclusion, the constellation of neuronal structures activated by fundus distension overlaps the pain matrices induced musculocutaneous pain, with the exception of the absence of SI or SII activation. This may account for the vague nature of visceral sensation/pain. Our data also confirms that the insula and amygdala may act as the central role in visceral sensation/pain, as well as in the proposed sensory-limbic model of learning and memory of pain.

We have investigated the mechanisms underlying acute changes in gastric motor function triggered by endotoxemia. In fundal strips from rats pre-treated with endotoxin (40 microg/kg, i.p. 30 min), mechanical activity was analyzed and the source of nitric oxide (NO) was visualized by confocal microscopy of tissue loaded with the fluorescent dye DAF-FM. NOS expression was determined by quantitative RT-PCR and Western blot, and enzyme activity by the citrulline assay. Strips from endotoxin-treated rats were hypo-contractile. This was prevented by pre-incubation with the neurotoxin tetrodotoxin, the gangliar blocker hexamethonium, or non-selective and neuronal-specific NOS inhibitors (L-NOARG and TRIM, respectively). The soluble guanylyl cyclase (sGC) inhibitor ODQ and the inhibitor of small conductance Ca2+-activated K+ channels apamin prevented relaxation induced by endotoxin, nicotine, exogenous NO (DETA-NONOate), and the NO-independent sGC activator BAY 41-2272. NO synthesis was observed in neuronal soma, axons, and nerve endings of the myenteric plexus in the fundus of endotoxin-treated rats and was prevented by L-NAME, tetrodotoxin, and hexamethonium. nNOS and iNOS mRNA and protein contents were unchanged. Our findings demonstrate synthesis of NO in post-ganglionic myenteric neurons during early endotoxemia that mediates gastric hypo-contractility. The effect of NO is mediated via sGC and small conductance Ca2+-activated K+channels.

Aim: The benefit of anti-reflux surgery for gastro-oesophageal reflux (GOR) in early infancy is uncertain. The aim of this study was to assess the value of Nissen fundoplication in a group of infants with severe GOR., Methods: 10 infants underwent Nissen fundoplication for gastro-oesophageal reflux following a failure of medical management. All had suffered life-threatening respiratory episodes as a consequence of gastro-oesophageal reflux, and were neonatal intensive care-dependent. Median (range) birth weight was 1.26 kg (0.48-3.8 kg), gestation 30 weeks (25-38 weeks); at surgery, weight was 3.25 kg (2.5-6.1 kg) at a corrected age of 11.5 weeks (term-22) weeks. For each infant, the success of enteral feeding and the level of support required pre- and post-operatively was compared, and where appropriate, the facilitation of palliative feeding was assessed. Median follow-up was 14 (3-36) months., Results: No infant suffered intra-operative morbidity or mortality. One infant died within 1 month of surgery from a collapse unrelated to surgery. Eight of nine surviving infants were discharged from intensive care following extubation and the establishment of enteral feeding. One patient died of severe bronchopulmonary dysplasia 3 months post-surgery. One infant developed a gastrostomy site infection, and two required gastrostomy tube replacement within 6 months of surgery. All were thriving at follow-up. Two infants with a congenital myopathy died as a result of their muscle disease at 9 and 11 months post-operatively., Conclusions: Nissen fundoplication is a feasible, effective and safe operation in severe gastro-oesophageal reflux unresponsive to medical treatment in term and pre-term infants. It has an additional important role in facilitating safe palliative enteral feeding in infants with a diagnosis incompatible with survival into adulthood.

Purpose: The present study investigated the effects of acid and mixed reflux on the responsiveness of gastric smooth muscle in the gastroesophageal reflux (GER) rat model., Material and Methods: Three groups of rat were studied encompassing acid reflux, mixed reflux and sham operation. Acid reflux was induced by pyloric ligation (AR group) and mixed reflux was induced by jejunal ligation 1 cm distal to Treitz ligament (MR group). Similar surgical manipulations were carried out in the sham operated rats (SO group). Carbachol-, serotonin-, KCl-induced contractile response and nicotine-, sodium nitroprusside-, papaverine-induced relaxant response in isolated gastric fundus smooth muscle strips were determined using in vitro muscle technique 24 h after surgery., Results: Isolated gastric fundus smooth muscle contractility to serotonin, carbachol or KCl was significantly reduced in the AR and MR groups with decreased Emax and pD(2) values compared with the SO group. Relaxant responses to nicotine was significantly increased in the AR and MR groups with increased Emax and pD(2) values compared with the SO group. Sodium nitroprusside and papaverine-induced-relaxant responses were similar in all of the groups and there was no change in agonist potency., Conclusion: The present study indicates that decreased contractile and increased nicotine-induced relaxant response of the gastric smooth muscle in the surgically created GER model. These findings suggest that impaired gastric smooth muscle reactivity at least in part may play a role in gastric dysmotility in GER.

Purpose: The aim of the study was to investigate the gastric smooth muscle reactivity in the Adriamycin-induced esophageal atresia (EA) rat model., Methods: The fetuses were divided into 3 groups. The control group was exposed to saline. The second group was comprised of fetuses that were exposed to Adriamycin but did not have EA (Adriamycin-no-EA group). The third group was comprised of fetuses that were exposed to Adriamycin and had EA (Adriamycin-EA group). Gastric fundus strips were studied in vitro for their contractile response to receptor activation in the 3 groups., Results: Contractile responses of gastric smooth muscle to carbachol and KCl were increased in the Adriamycin-EA group compared with the Adriamycin-no-EA group. Also serotonin-induced contractile response in the Adriamycin-EA group decreased compared with the Adriamycin-no-EA group. Relaxation of gastric smooth muscle strips to isoproterenol was comparably unaffected in the Adriamycin-EA and Adriamycin-no-EA groups. Likewise, no change in the response to agonist studies was observed between the control and Adriamycin-no-EA groups. The relaxant response to papaverine was not different in the 3 groups., Conclusions: This study found changes of receptor-dependent and receptor-independent contraction of the gastric fundus smooth muscle in the fetuses with EA. Therefore, impaired contractile responses may be, at least in part, a contributing factor in the abnormal gastric motility seen in EA.

Diabetes mellitus is a major cause of neuropathy, leading to adverse effects including autonomic gastrointestinal dysfunction. Oxidative stress contributes to the etiology of diabetic neuropathy. The aim was to examine whether treatment with the antioxidant, alpha-lipoic acid (LA), could prevent or correct diabetic functional defects in the gastric fundus non-adrenergic, non-cholinergic (NANC) nerves, which use nitric oxide as their major neurotransmitter. LA (100 mg/kg/d) was given in a prevention study for 8 weeks following streptozotocin-diabetes induction, and in an intervention study for 4 weeks after 4 weeks of untreated diabetes. Fundus strips were studied in vitro after precontraction with 5-hydroxytryptamine in the presence of guanethidine and atropine to isolate NANC relaxation to electrical field stimulation. After 4 and 8 weeks of diabetes, there were 26% and 48% deficits in maximum relaxation, respectively. Prevention LA treatment gave 83% protection; intervention LA prevented the deterioration between 4 and 8 weeks of diabetes and corrected the initial 4 week deficit by 56%. Diabetes also resulted in a failure to maintain relaxation for prolonged stimulation, which was prevented by LA. Thus, LA prevented and reversed the development of impaired gastric fundus NANC responses in diabetic rats, which has potential therapeutic implications for gastrointestinal autonomic neuropathy.

Background & Aims: Symptoms in functional dyspepsia have been related to impaired accommodation and hypersensitivity of the proximal stomach. We hypothesized that identification of putative antral dysfunctions provides a more comprehensive pathophysiological interpretation., Methods: In 30 patients with functional dyspepsia and 22 healthy subjects, 2 consecutive studies were performed. In study I, with the subjects in the upright position, the proximal and distal stomach were selectively distended by bags containing air and water, respectively, while perception and fundic relaxation in response to antral distention were measured. In study II, by using air-filled bags connected to a tensostat, the proximal and the distal stomach were selectively distended by positioning the subjects on the right and left lateral decubitus, respectively, while perception, compliance, and the responses to intestinal nutrient infusion were measured., Results: Patients with dyspepsia showed hypersensitivity of both the proximal stomach (discomfort at 30 +/- 3 g vs. 62 +/- 2 g in controls; P < 0.05) and the antrum (discomfort at 31 +/- 2 g vs. 53 +/- 4 g in controls; P < 0.05). Fundic and antral fasting tone was normal, but reflex fundic relaxation induced either by antral distention (3 +/- 16 mL at 80 mL of distention vs. 38 +/- 10 mL in controls; P < 0.05) or by intestinal nutrients (35 +/- 7 mL vs. 107 +/- 8 mL in controls; P < 0.05) was markedly impaired., Conclusions: Antral and fundic dysfunctions interact to produce the symptoms of functional dyspepsia, and impaired control of fundic accommodation may lead to overload of a hypersensitive antrum.

Background/aims: After variceal eradication by endoscopic ligation, fundal varices and worsening of portal hypertensive gastropathy can occur. The aim of this study is to verify the impact of the eradication of esophageal varices by endoscopic ligation on the portal pressure gradient, worsening of portal hypertensive gastropathy and development of fundal varices., Methodology: Twenty-two (15M/7F, mean age: 54.5 years) cirrhotics with previous variceal bleeding were submitted to measurement of hepatic venous pressure gradient before and after variceal eradication by endoscopic ligation., Results: The mean hepatic venous pressure gradient in the first measurement was 14.1 mmHg and after eradication, 13.5 mmHg (p = 0.403). After eradication, 12 patients experienced a reduction in portal pressure and 10, an elevation. Three patients developed fundal varices. Their mean gradient before treatment was 22 mmHg and 18.8 mmHg after therapy (p = 0.368). The gastropathy worsened in 9 patients (mean gradient before therapy of 15.2 mmHg; and 16.1 mmHg after treatment) (p = 0.303). The initial pressure gradient of these patients was not different from the other 13 cases (p = 0.463)., Conclusions: The esophageal variceal eradication by endoscopic band ligation does not alter the hepatic venous pressure gradient. There is no significant variation in the portal pressure of patients in whom there was a worsening of portal hypertensive gastropathy or fundal varices development.

During intestinal inflammation, motility disturbances are not restricted to inflamed regions, but may also occur in remote non-inflamed sites of the gastrointestinal tract. Our aim was to investigate the motor function of the gastric fundus after the induction of terminal ileitis in the rat. Ileal inflammation was induced by intraluminal installation of 2,4,6-trinitrobenzenesulphonic acid (TNBS) into the ileum. Inflammation was assessed both histologically and biochemically. Contractions and relaxations of longitudinal muscle strips from the gastric fundus were studied 36 h and 1 week later. During the acute phase of ileal inflammation (36 h), the non-inflamed stomach was distended. The contractility of longitudinal muscle strips of the gastric fundus was decreased due to a post-receptor defect. In addition, nonadrenergic noncholinergic (NANC) relaxations were inhibited due to neuronal dysfunction. Aortic contractility remained normal and the mere presence of food in the stomach did not account for the disturbed neuromuscular function in the gastric fundus. Ablation of extrinsic primary afferent neurones by capsaicin further impaired gastric fundus contractility. Transection and re-anastomosis of the jejunum reversed the effect of TNBS-induced ileitis on the neuromuscular function of the gastric fundus. One week after TNBS, cholinergic neurotransmission was increased in the gastric fundus. During acute ileitis, smooth muscle cell contractility and inhibitory NANC neurotransmission are inhibited in the non-inflamed gastric fundus. This phenomenon may be mediated by intrinsic connections within the enteric nervous system.

Objective: Topographical manometric methods have improved the understanding of esophageal peristalsis in research applications but require a large number of recording sensors. Commonly used methods limited to four sensors were compared to topographical methods to determine whether the latter also had significant clinical utility., Methods: Two hundred twelve patients referred for esophageal manometry were studied with a data acquisition system having 21 intraluminal recording sites, and the findings were analyzed independently using both limited (pull-through plus four recording sites) and topographical approaches (all sites). Discrepant results were clarified using supportive clinical data., Results: The two methods were in diagnostic agreement in 187 cases (88.2%). Topographical methods correctly identified all 26 patients with achalasia within the group with aperistalsis (n = 36). The limited methods could not confidently identify six achalasia patients and were significantly less effective in segregating aperistaltic disorders (p < 0.05 across methods). Topographical methods alone detected evidence of incomplete lower esophageal sphincter relaxation in 12 additional patients, eight of whom had clinical data supporting the findings. Topographical methods identified the upper margin of the lower sphincter in all but three subjects (1.4%); limited methods could not identify this location in these and five additional subjects (3.8%) and differed from the topographical measurement by > or = 2 cm in 11.9% of cases., Conclusions: Topographical methods are more accurate than commonly used methods in diagnosing the type of severe motor dysfunction and provide additional information important in the clinical practice of esophageal manometry.

The influence of streptozotocin-induced diabetes has been investigated on responses to non-adrenergic, non-cholinergic (NANC) nerve stimulation in rat gastric fundus. NANC relaxations in precontracted muscle strips from diabetic rats were smaller than those from control rats. In addition, the relaxations in diabetic but not control rats were followed by rapidly-developing frequency-dependent contractions. In the presence of alpha-chymotrypsin and N(G)-nitro-L-arginine methyl ester (L-NAME), the NANC contractions were markedly enhanced in diabetic rats. Treatment with the aldose reductase inhibitor, sorbinil, did not affect NANC relaxations or contractions in tissues from diabetic rats, and responses remained significantly different from those from control rats. The findings suggest that diabetes impairs relaxations to NANC nerve stimulation in the rat gastric fundus, and that a contractile NANC neurotransmitter(s) is released in diabetic rats. The results also suggest that diabetes-induced alterations in the NANC nerve response are not caused by increased activity of the aldose reductase pathway.

Relaxant responses to electrical field stimulation (EFS) were investigated in the gastric longitudinal fundus strips from young normal and mdx dystrophic mice, an animal model of Duchenne muscular dystrophy. In carbachol (CCh) precontracted strips from normal mice, EFS elicited brisk relaxant responses that, depending on stimulation frequency, could be followed by a sustained relaxation. In strips from mdx mice the brisk relaxation was impaired. Smooth muscle responses to direct stimulating agents did not differ in amplitude between the two groups of animals. In strips from both normal and mdx mice, N(G)-nitro-L-arginine (L-NNA) abolished the brisk phase of relaxation, without affecting the sustained response. alpha-chymotrypsin abolished, in both preparations, the sustained relaxant response to EFS as well as relaxation to vasoactive intestinal polypeptide. Results suggest that, in strips from mdx mice, a defective production/release of the neurotransmitter responsible for the brisk relaxation, likely nitric oxide, occurs.

Unlabelled: Acidosis impairs smooth muscle function in various organs. However, the effects of acidosis on the gastroduodenal tract are unknown while its dysfunction has potential perioperative harmful consequences. We investigated the effects of metabolic (MA) and respiratory acidosis (RA) on upper gut motility in tracheally ventilated pigs whose anesthesia was induced with halothane and maintained with alpha-chloralose-urethane administration (IV). Increased dead space and perfusion of hydrochloric acid 1 N (150 mL over 30 min) were used to induce RA and MA, respectively. Measurements of fundic tone using an electronic barostat, antro-pyloroduodenal phasic motility with perfused manometry and antro-duodenal electric control activity by electromyography were used to evaluate gastroduodenal function. Acidosis increased the fundic tone as reflected by a decrease in barostat volumes from 275+/-83 to 194+/-88 mL for MA and from 278+/-93 to 236+/-106 mL for RA. Pyloric and duodenal basal tones were not affected by either acidosis. A decrease in pyloric contraction amplitude from 95+/-24 to 62+/-26 mm Hg during MA and from 94+/-26 to 64+/-20 mm Hg during RA was observed. Both acidosis altered antral control activity that became dysrhythmic. Acidosis could be implicated in perioperative complications, such as gastroparesis, emesis, and regurgitation of gastric contents., Implications: Metabolic and respiratory acidosis mainly affects gastric antral rhythms and has a major effect on fundic tone. Acidosis could be implicated in perioperative complications, such as gastroparesis, emesis, and regurgitation of gastric contents.

Objective: Meals increase the rate of transient lower esophageal sphincter (LES) relaxations, in part by gastric distension. The 5HT1 agonist sumatriptan reduces fasting fundic tone, prolongs the meal-induced fundic relaxation, and delays gastric emptying. We therefore hypothesized that sumatriptan might have a significant effect on the rate of postprandial transient LES relaxations and gastroesophageal reflux. We aimed to study the effect of sumatriptan on postprandial transient LES relaxations and reflux in healthy subjects., Methods: Esophageal manometry and pH monitoring were performed in 13 healthy volunteers for 30 min before and 90 min after a semiliquid meal (790 kcal). Sumatriptan 6 mg subcutaneous (s.c.) or s.c. placebo were administered on separate days 30 min after the meal., Results: Sumatriptan significantly increased postprandial LES pressure from 11.0 +/- 1.2 mm Hg to 17.6 +/- 1.2 mm Hg (p < 0.05). However, reflux events were not diminished. In the contrary, reflux was more frequent after sumatriptan than after placebo (3 [1.5-4.5]/30 min vs 2 [0-3]/30 min, p < 0.05). Transient LES relaxations were more frequent after sumatriptan, particularly in the second 30-min period after drug administration (3 [2.5-5]/30 min vs 2 [1.5-2]/30 min, p < 0.05)., Conclusions: Sumatriptan prevents the natural decay in rate of transient LES relaxations that occurs after a meal and favors the occurrence of gastroesophageal reflux despite increasing LES pressure. The sustained postprandial high rate of transient LES relaxations after sumatriptan may be a consequence of a prolonged fundus relaxation and retention of meal in the proximal stomach.

Objective: Helicobacter pylori (H. pylori) can augment the pH-increasing effect of omeprazole in patients with peptic ulcer. A high intragastric pH may be helpful in preventing recurrent hemorrhage by stabilizing the blood clot at the ulcer base of bleeding peptic ulcer patients. Therefore, we hypothesized that omeprazole may reduce short-term rebleeding rate in these patients with H. pylori infection after initial hemostasis had been obtained., Methods: Between July 1996 and December 1998, 65 bleeding peptic ulcer patients (24 gastric ulcer, 41 duodenal ulcer) who had obtained initial hemostasis with endoscopic therapy were enrolled in this trial. Thirty (46.2%) of them were found to have H. pylori infection by a rapid urease test and pathological examination. For all studied patients, omeprazole was given 40 mg intravenously every 6 h for 3 days. Thereafter, omeprazole was given 20 mg per os (p.o.) once daily for 2 months. A pH meter was inserted in the fundus of each patient under fluoroscopic guidance after intravenous omeprazole had been administered. The occurrence of rebleeding episode was observed for 14 days., Results: In patients with H. pylori infection, intragastric pH (median, 95% confidence interval [CI]: 6.54, 5.90-6.68) was higher than in those without H. pylori infection (6.05, 5.59-6.50, p < 0.001). However, the patients with rebleeding (2 vs 3), volume of blood transfusion (median, range: 1000 ml, 0-2250 vs 750, 0-2000), number of operations (0 vs 1), mortality caused by bleeding (0 vs 0), and hospital stay (median, range: 6 days, 3-14 vs 7, 5-16) were not statistically different from those without H. pylori infection., Conclusions: Omeprazole does increase intragastric pH in bleeding peptic ulcer patients with H. pylori infection. However, the presence of H. pylori infection does not affect the short-term rebleeding rate in these patients.

Regulation of smooth muscle contractility is essential for many important biological processes such as tissue perfusion, cardiovascular haemostasis and gastrointestinal motility. While an increase in calcium initiates smooth muscle contraction, relaxation can be induced by cGMP or cAMP. cGMP-dependent protein kinase I (cGKI) has been suggested as a major mediator of the relaxant effects of both nucleotides. To study the biological role of cGKI and its postulated cross-activation by cAMP, we inactivated the gene coding for cGKI in mice. Loss of cGKI abolishes nitric oxide (NO)/cGMP-dependent relaxation of smooth muscle, resulting in severe vascular and intestinal dysfunctions. However, cGKI-deficient smooth muscle responded normally to cAMP, indicating that cAMP and cGMP signal via independent pathways, with cGKI being the specific mediator of the NO/cGMP effects in murine smooth muscle.

It has been proposed that kinins are important inflammatory mediators involved in the pathogenesis of several diseases. In the present study, we attempted to determine the effects of kinins in a type I diabetic mouse model, using in vitro assays. Injection of streptozotocin (STZ) to the C57BL/Ks mdb mice causes an insulitis (inflammation of Langerhans islets) that leads to the diabetic condition. Ten days following the STZ treatment, the mice showed increased glycemia. We examined the effect of kinins and other agents (substance P, neurokinin A, acetylcholine) on the stomach fundus and urinary bladder of control and diabetic mice. Our results show that the sensitivity of the stomach fundus to bradykinin (BK) and desArg9BK (DBK), but not to other contractile agents, was substantially increased in the tissues of diabetic mice. The maximal contractions induced by BK and DBK were increased 1.5- to 2-fold in the stomachs from diabetic mice compared with those from normal mice. BK induced similar maximal contractions of urinary bladder strips from normal or STZ-treated mice, while DBK did not show any effect on this preparation. Interestingly, the apparent affinities of all agonists are similar in the two groups, normal and diabetic. These results suggest that B1 and B2 receptors are overexpressed in the stomach fundus but not in the urinary bladder of diabetic mice.

Background/aims: The authors compared the results of the Nissen fundoplication technique with the results of the Hill procedure, by using a 10-year history of patients with gastro-esophageal reflux disease., Materials and Methods: Seventy two consecutive patients entered the study, 32 of whom underwent a 360 degrees fundoplication according to Nissen and 40 with a modified Hill operation. In the Nissen Group, intraoperative manometry (IOM) was carried out in all patients; in the Hill Group, the patients were randomized in two sub-groups (A and B), before operation; in 20 of them (group A), the procedure was randomly associated to IOM., Results: The overall complications were low in both groups (15.6% in the Nissen Group and 5% in the Hill Group, p = 0.1), and there was no mortality rate. The clinical results were excellent or good in 28 patients (87.6%) of the Nissen Group and in 36 patients (90%) of the Hill Group (p = 0.5); in particular, an excellent outcome was observed in 16 patients (80%) with IOM (sub-group A), while 12 patients (60%) without it (sub-group B) showed similar results. The manometric studies carried out six months after surgical treatment showed a decrease of the lower esophageal sphincter pressures in all patients if compared to the pressure recorded intra-operatively. In comparison to the pre-operative values, both the lower esophageal sphincter length and its intra-abdominal portion were markedly increased in the Nissen Group and in the sub-group A of the Hill patients., Conclusions: These results support the conclusions that modified posterior gastropexy and 360 degrees fundoplication are effective, well tolerated, and can be properly used in the treatment of Gastro-esophageal reflux disease (GERD), since both techniques showed good clinical results. A favorable clinical outcome depends mostly on adequate lower esophageal sphincter length (LESL) and LESIA extension, which could be more efficiently achieved by the use of intraoperative manometry (IOM).

Abdominal x-radiation produces both acute and chronic disturbances of gastrointestinal motility. Anaesthetized Albino-Oxford rats received one-session x-radiation (absorbed dose 10 Gy) of whole abdomen. Two hours after irradiation the rats were sacrificed and segments of their gastrointestinal tract (gastric fundus, jejunum, ileum and ascending colon, were mounted in isolated organ bath. Acetylcholine and 5-hydroxytryptamine produced tonic contractions of all gut segments, while histamine did so only with gastric fundus. While contractile effect of 5-hydroxytryptamine was not affected by x-radiation, the responses of all gut segments on acetylcholine were potentiated and shifted towards lower concentrations. After x-radiation histamine produced concentration-dependent tonic contraction of previously unresponsive jejunum and ascending colon. The results of our study suggest that x-radiation produces acute sensitization of rat gastrointestinal tract to acetylcholine and histamine.

Using a unipolar esothoracic pacing system (where current passes from a point source positioned in the distal esophagus to a chest wall pad) and pulse duration of 50 msec, satisfactory 1:1 ventricular capture was obtained in 57 (86%) of 66 patients, with a mean threshold current of 27.7 mA at an optimal depth of 40.3 cm from the lower lip. When the unipolar esothoracic and bipolar transesophageal ventricular pacing systems were compared, the bipolar system was associated with a lower success rate and higher threshold current. When unipolar esothoracic pacing and gastrothoracic pacing (where current passes from a point source positioned in the stomach to a chest wall pad) were compared in 23 patients with bradyarrhythmia, ventricular capture was achieved using gastrothoracic pacing in 22 patients (96%) and esothoracic pacing in 21 (91%): gastrothoracic pacing required less current (16.0 mA +/- SD 7.2 vs 25.8 mA +/- SD 8.6). Optimal ventricular capture occurred using a unipolar gastrothoracic pacing electrode inserted to an average depth of 44.3 cm together with a high impedance chest pad (250 omega) placed in the fourth interspace at the left sternal edge, with 50-msec current pulses and a mean threshold of 16.0 mA. Thus, using a gastroesophageal electrode system, ventricular pacing can be achieved successfully, and the availability of such a system could play a major role in resuscitation of patients from severe bradyarrhythmias.