Enhancement of salivary esophagoprotection: rationale for a physiological approach to gastroesophageal reflux disease

Differences in salivary secretion and epidermal growth factor concentrations in mild reflux esophagitis and non-erosive reflux disease

BACKGROUND

Sex differences in salivary secretion have been reported among healthy subjects. In the present study, salivary secretion and salivary epidermal growth factor (EGF) concentrations were investigated in mild reflux esophagitis patients, non-erosive reflux disease (NERD) patients, and healthy controls by matching the sex ratio.

METHODS

Thirty-three (male:female = 11:22) patients with NERD, 33 (11:22) with mild reflux esophagitis, and 33 (11:22) healthy controls were recruited for this case-control study. Salivary secretion was assessed as follows: each patient chewed sugar-free gum for 3 min prior to endoscopy, and the amount of saliva secretion, salivary pH, and salivary pH after acid loading as an index of the acid-buffering capacity were measured. Salivary EGF concentrations were measured by ELISA.

RESULTS

No significant differences were observed in the amount of saliva secretion, salivary pH, or the acid-buffering capacity between the mild reflux esophagitis and NERD groups. However, the amount of saliva secretion and the acid-buffering capacity in the mild reflux esophagitis group and the amount of saliva secretion, salivary pH, and the acid-buffering capacity in the NERD group were significantly lower than those in the healthy control group. No significant differences were noted in salivary EGF concentrations between the mild reflux esophagitis and NERD groups.

CONCLUSION

After matching the sex ratio, the saliva secretion was significantly lower in patients with mild reflux esophagitis and NERD than in healthy controls. However, no significant differences were observed in the amount of saliva secretion or salivary EGF concentrations between both groups.

Xerogenic medications may contribute to decreased unstimulated salivary flow in patients with oral burning and/or gastro-esophageal reflux disease

Background

Patients who complain of mucosal burning sensations (i.e., glossodynia and gastro-esophageal reflux disease, GERD) often take multiple medications. However, the relationship between xerogenic medication intake and salivary flow in these patients has not been thoroughly examined.

Methods

A retrospective study of 192 consecutive patients diagnosed with glossodynia (ICD-10-CM) at a regional center over a six-year period was performed. Data from electronic health records were extracted and relationships between medication intake, unstimulated whole salivary flow rate (UWSFR), xerostomia and GERD were determined by chi-square, t-test, and correlation analysis.

Results

Of 134 records that met inclusion criteria, 87.1% of patients reported daily intake of one or more xerogenic medications. Two or more xerogenic medications were taken significantly more often by patients with glossodynia reporting GERD than those with glossodynia without GERD (p = .02). UWSFR was negatively correlated with number of medications [r(103) = −.277, p = .005] and xerogenic medications [r(103) = −.195, p = .049]. The lowest UWSFR was observed with use of trazodone and cyclobenzaprine.

Conclusions

Daily xerogenic medication intake, hyposalivation, and xerostomia were commonly present and potentially interrelated in patients who suffer from glossodynia and/or GERD.

Practical implications

Clinicians should be aware of the consequences of prescribing multiple and certain xerogenic medications in reducing UWSFR, especially in patients physiologically at risk of hyposalivation such as those suffering from GERD and/or glossodynia.

Saliva secretion is reduced in mild reflux esophagitis patients

BACKGROUND

Salivary secretion in patients with mild reflux esophagitis has not been examined. In this study, saliva secretion and salivary epidermal growth factor (EGF) in patients with mild reflux esophagitis were investigated.

METHODS

Thirty-eight mild reflux esophagitis patients and 38 control subjects were recruited for this case-control study. Saliva secretion testing was performed. Saliva secretion was assessed as follows: each patient chewed sugar-free gum for 3 min prior to endoscopy, and the volume and pH of saliva before and after acid loading as an index of the acid-buffering capacity were measured. The salivary EGF concentration was assessed by ELISA.

RESULTS

The volume of saliva secreted was significantly (p = 0.0412) lower in the mild reflux esophagitis group than in the control group, with medians (25th-75th percentile) of 4.2 mL/3 min [2.6-6.2] and 6.0 [3.9-8.0], respectively. No significant differences were observed in salivary pH (the mild reflux esophagitis group: 7.1 [6.9-7.2], the control group 7.2 [7.1-7.3]). Salivary pH after acid loading was significantly (p = 0.0009) lower in the mild reflux esophagitis group (5.9 [5.5-6.3]) than in the control group (6.3 [6.2-6.5]). No significant differences were noted in salivary EGF concentrations (the mild reflux esophagitis group: 1739.0 pg/mL [1142.3-3329.0], the control group: 1678.0 [1091.8-2122.5].

CONCLUSION

The secretion volume and acid-buffering capacity of stimulated saliva were reduced in patients with mild reflux esophagitis.

Stimulated saliva secretion is reduced in proton pump inhibitor-resistant severe reflux esophagitis patients

BACKGROUND

Salivary secretion in patients with proton-pump inhibitor (PPI)-resistant severe reflux esophagitis has not been examined. In this study, saliva secretion and salivary epidermal growth factor (EGF) in patients with PPI-resistant severe reflux esophagitis were investigated.

METHODS

We recruited 22 PPI-resistant and 22 PPI-responsive severe reflux esophagitis patients who were not infected with Helicobacter pylori. Saliva secretion testing and esophageal manometry using high-resolution manometry were performed. Saliva secretion was assessed as follows: each patient chewed sugar-free gum for 3 min prior to endoscopy and the amount and pH of saliva as well as the pH of saliva after acid loading as an index of the acid-buffering capacity were measured. The salivary EGF concentration was assessed by ELISA.

RESULTS

The amount of saliva secreted was significantly lower in the PPI-resistant group than in the PPI-responsive group, with medians (25th-75th percentile) of 3.7 (2.2-6.8) and 4.9 (4.0-7.8) mL, respectively (p = 0.029). Salivary pH was significantly lower in the PPI-resistant group [6.9 (6.7-7.2)] than in the PPI-responsive group [7.2 (7.1-7.4), p = 0.001]. Salivary pH after acid loading was significantly lower in the PPI-resistant group [5.6 (5.3-5.9)] than in the PPI-responsive group [6.4 (6.1-6.5), p = 0.002]. The salivary EGF concentration was significantly higher in the PPI-resistant group [3211.5 (1865.0-4121.5)] than in the PPI-responsive group [1816.0 (1123.5-2792.3), p = 0.041]. No significant differences were observed in the proportion of esophageal motility abnormalities.

CONCLUSION

Stimulated saliva secretion was reduced in PPI-resistant severe reflux esophagitis patients.

The esophageal mucosal barrier in health and disease: mucosal pathophysiology and protective mechanisms

Diseases of the esophagus, such as gastroesophageal reflux (GER), can result in changes to mucosal integrity, neurological function, and the microbiome. Although poorly understood, both age and GER can lead to changes to the enteric nervous system. In addition, the esophagus has a distinct microbiome that can be altered in GER. Mucosal integrity is also at risk due to persistent damage from acid. Diagnostic tools, such as ambulatory pH/impedance testing and esophageal mucosal impedance, can assess short-term and longitudinal GER burden, which can also assess the risk for mucosal compromise. The quality of the mucosal barrier is determined by its intercellular spaces, tight junctions, and tight junction proteins, which are represented by claudins, occludins, and adhesion molecules. Fortunately, there are protective factors for mucosal integrity that are secreted by the esophageal submucosal mucous glands and within saliva that are augmented by mastication. These protective factors have potential as therapeutic targets for GER. In this article, we aim to review diagnostic tools used to predict mucosal integrity, aging, and microbiome changes to the esophagus and esophageal mucosal defense mechanisms.

Chronic Gingivostomatitis with Esophagitis in Cats

BACKGROUND

Chronic gingivostomatitis in cats (FCG) is a debilitating disease with potentially deleterious effects on overall health.

HYPOTHESIS/OBJECTIVES

Little is known about the pathophysiology and overall impact of FCG. The aims of our study were to investigate whether gingivostomatitis occurs concurrently with esophagitis, if FCG treatment contributes to esophagitis and if esophagitis exacerbates signs of FCG.

ANIMALS

Fifty-eight cats with clinical signs of FCG and 12 healthy control cats exhibiting no signs of oral disease, all client-owned.

METHODS

Prospective study. Physical, oral and endoscopic examinations were performed on all cats. Measurements of salivary and esophageal lumen pH were obtained from both groups. Biopsies were acquired from sites of esophageal inflammation in cats with FCG and from normal-appearing esophageal mucosa in control cats.

RESULTS

The majority of cats with clinical signs of FCG exhibited some degree of esophagitis especially in the proximal (44/58) and distal (53/58) parts (P < 0.001) with or without columnar metaplasia, compared to controls. All cats lacked signs related to gastrointestinal disease. Salivary and esophageal lumen pH were not statistically different compared to controls.

CONCLUSIONS AND CLINICAL IMPORTANCE

Feline chronic gingivostomatitis seems to occur concurrently with esophagitis. Esophagitis also should be managed in cats with chronic gingivostomatitis because it may aggravate the existing condition.

Does the healing of the esophageal mucosa improve the function of the esophageal submucosal and salivary glands?

The esophageal pre-epithelial barrier encompasses components of secretions from both the esophageal submucosal and salivary glands. We demonstrated, in patients with reflux esophagitis (RE), significantly diminished luminal release of esophageal epidermal growth factor (EGF). The rate of luminal release of esophageal prostaglandin E₂ (PGE₂ ) was significantly higher compared with controls and significantly declined after healing of RE. Patients with RE also exhibited significant declines in esophageal mucin secretion; however, after healing of RE with rabeprazole, this rate increased significantly. The rate of salivary EGF and bicarbonate secretion in patients with RE was significantly lower than in controls. We have demonstrated that mastication of tasteless parafilm, which could be substituted with sugarless chewing gum in the clinical scenario, resulted in profound and significant increases in the rate of secretion of salivary protective factors, such as bicarbonate, mucin, protein, EGF, and PGE₂ , in patients with RE. Our data clearly indicate that there is a relationship between the form or the structure of the esophageal mucosa and the secretory function of not only the esophageal submucosal glands but also the salivary glands. Application of masticatory stimulation in a clinical scenario may also have some therapeutic potential.

The ontogeny of saliva secretion in infants and esophagoprotection

BACKGROUND

Several studies have reported that severe reflux esophagitis is rare in infants despite the well known high occurrence of regurgitation in early infancy. There is evidence of the importance of saliva for the pre-epithelial protection of the esophageal mucosa.

RESULTS

A longitudinal study conducted on healthy infants indicated that the stimulated capacity of saliva secretion (saliva output per kg of body weight) was significantly higher during their first year of age compared to older children and adults. In addition, this secretion pattern was also observed in low weight newborns during the first weeks of life and persisted in infants with severe protein-calorie malnutrition (marasmus).

CONCLUSION

The greater ability to secrete saliva is an important physiological condition that may protect the infant from acid/pepsin aggression to the esophagus during early stages of development.

Role of saliva in esophageal defense: implications in patients with nonerosive reflux disease

Background:

It has been previously demonstrated that patients with reflux esophagitis exhibit a significant impairment in the secretion of salivary protective components versus controls. However, the secretion of salivary protective factors in patients with nonerosive reflux disease (NERD) is not explored. The authors therefore studied the secretion of salivary volume, pH, bicarbonate, nonbicarbonate glycoconjugate, protein, epidermal growth factor (EGF), transforming growth factor alpha (TGF-α) and prostaglandin E2 in patients with NERD and compared with the corresponding values in controls (CTRL).

Methods:

Salivary secretion was collected during basal condition, mastication and intraesophageal mechanical (tubing, balloon) and chemical (initial saline, acid, acid/pepsin, final saline) stimulations, respectively, mimicking the natural gastroesophageal reflux.

Results:

Salivary volume, protein and TGF-α outputs in patients with NERD were significantly higher than CTRL during intraesophageal mechanical (P < 0.05) and chemical stimulations (P < 0.05). Salivary bicarbonate was significantly higher in NERD than CTRL group during intraesophageal stimulation with both acid/pepsin (P < 0.05) and saline (P < 0.01). Salivary glycoconjugate secretion was significantly higher in the NERD group than the CTRL group during chewing (P < 0.05), mechanical (P < 0.05) and chemical stimulation (P < 0.01). Salivary EGF secretion was higher in patients with NERD during mechanical stimulation (P < 0.05).

Conclusions:

Patients with NERD demonstrated a significantly stronger salivary secretory response in terms of volume, bicarbonate, glycoconjugate, protein, EGF and TGF-α than asymptomatic controls. This enhanced salivary esophagoprotection is potentially mediating resistance to the development of endoscopic mucosal changes by gastroesophageal reflux.

The effects of baclofen for the treatment of gastroesophageal reflux disease: a meta-analysis of randomized controlled trials

Objectives. Baclofen can relieve gastroesophageal reflux-related symptoms in healthy subjects and gastroesophageal reflux disease (GERD) patients by reducing the incidence of transient lower esophageal sphincter relaxation. This meta-analysis aimed to evaluate the efficacy and safety of baclofen for the treatment of GERD. Methods. We systematically searched randomized controlled trials published prior to November 2013 from PubMed, Medline, Embase, ScienceDirect, ClinicalTrials.gov, and the Cochrane Central Register of Randomized Controlled Trials. We performed a meta-analysis of all eligible trials. Results. Nine studies were identified with a total of 283 GERD patients and healthy subjects. Comparative analysis provided high quality data supporting the ability of baclofen to promote a short-term decrease in the number of reflux episodes per patient, the average length of reflux episodes, and the incidence of transient lower esophageal sphincter relaxation. No serious adverse events or death events were reported, and there were no significant differences in the overall adverse events between baclofen and placebo. All reported side effects of baclofen were of mild-to-moderate intensity, and the drug was well tolerated. Conclusion. Abundant evidence suggests that baclofen may be a useful approach for the treatment of GERD patients; however, a larger well-designed research study would further confirm this recommendation.

A distinct salivary secretory response mediated by the esophago-salivary reflex in patients with Barrett's esophagus: its potential pathogenetic implications

PURPOSE

A significantly compromised epidermal growth factor (EGF) secretion by basal parotid saliva may contribute to the development of Barrett's esophagus (BE). The rate of secretion of EGF as well as a wide spectrum of protective factors in total basal and stimulated saliva in BE patients remains to be explored. We therefore studied the rate of secretion of salivary buffers, glycoconjugate, protein, EGF, transforming growth factor α (TGFα) and prostaglandin E₂ (PGE₂), evoked by esophago-salivary reflex, in patients with BE and controls (CTRL).

MATERIAL/METHODS

Salivary secretion was collected during basal condition, mastication, and intraesophageal mechanical and chemical stimulations respectively, mimicking the natural gastroesophageal reflux scenario.

RESULTS

Salivary pH in BE was significantly lower than in controls during mechanical (p<0.001) and chemical stimulations (p<0.001). Bicarbonate and protein outputs in BE were significantly lower during mechanical (p<0.05) and chemical stimulations (p<0.01). The non-bicarbonate and glycoconjugate outputs in BE were lower during chemical stimulation (p<0.05) and during mechanical (p<0.05) and chemical stimulations (p<0.05) respectively. The rate of salivary EGF output in BE was significantly lower during mechanical stimulation (p<0.05). We observed a higher TGFα output during mastication (p<0.05) and PGE2 secretion during basal and masticatory condition (p<0.05) in BE.

CONCLUSIONS

Patients with BE demonstrated significantly compromised salivary pH and rate of secretion of bicarbonate, non-bicarbonate, glycoconjugate, protein and EGF. This impairment could potentially predispose to the development of accelerated esophageal mucosal injury. Potential restoration of this impairment by masticatory stimulation of salivary secretion using sugarless chewing gum justifies further clinical exploration.

Salivary transforming growth factor alpha in patients with Sjögren's syndrome and reflux laryngitis

Introduction

Saliva plays a key role in the homeostasis of the digestive tract, through its inorganic components and its protein growth factors. Sjögren's syndrome patients have a higher prevalence of gastroesophageal reflux disease and laryngopharyngeal reflux. Decreased salivary transforming growth factor alpha levels were observed in dyspeptic patients, but there have been no studies in patients with Sjögren's syndrome and laryngopharyngeal reflux.

Objective

To compare the salivary transforming growth factor alpha levels of patients with Sjögren's syndrome and laryngopharyngeal reflux to those of healthy controls.

Methods

This is a prospective controlled study. Twelve patients with Sjögren's syndrome and laryngopharyngeal reflux and 11 controls were prospectively evaluated. Spontaneous and stimulated saliva samples were obtained to establish salivary transforming growth factor alpha concentrations.

Results

The salivary transforming growth factor alpha levels of patients were significantly higher than those of healthy controls. Five patients with laryngopharyngeal reflux also had erosive esophagitis; their salivary transforming growth factor alpha levels were comparable to controls.

Conclusion

Salivary transforming growth factor alpha level was significantly higher in patients with Sjögren's syndrome and laryngopharyngeal reflux when compared to the control group.

A review of the fundamentals of diet

Dietary recommendations should be individualized for each patient, but certain basic principles apply to most people. A healthful diet should include a wide variety of whole, unprocessed foods that are free of additives and, if possible, grown without the use of pesticides, herbicides, and other potentially toxic agricultural chemicals. For people who do not have specific food intolerances, such a diet generally includes liberal amounts of fresh fruits and vegetables, whole grains, nuts, seeds, and legumes. For most people, animal foods such as eggs, fish, chicken, beef, and dairy products can be healthfully consumed in moderation. It is not necessary to consume animal foods to maintain good health. In fact, compared with omnivores, vegetarians have a lower risk of developing a number of chronic diseases. However, vegetarians must carefully plan their diet so as not to develop nutritional deficiencies.

Pathophysiology of gastroesophageal reflux disease

The gastroesophageal junction is structurally complex and functionally designed to ensure the acid secreted by the most proximal gastric mucosa flows towards the stomach and not up onto the oesophageal squamous mucosa. The pattern and mechanism of reflux vary with the severity of reflux disease and this probably represents different ends of a spectrum rather than distinct pathophysiological mechanisms. Nearly all patients with severe reflux disease have hiatus hernia, however, a substantial proportion of patients with mild reflux disease do not, and this may be a result of intermittent or partial hiatus hernia undetectable by current available tools. The acid pocket is an area of post-prandial unbuffered gastric acidity immediately distal to the gastroesophageal junction and which is enlarged in patients with hiatus hernia. The acid pocket provides a reservoir of acid available to reflux when the intrinsic sphincter fails. Central obesity is an important factor in the aetiology of reflux and does this by the increased abdomino-thoracic pressure gradient inducing hiatus hernia and increasing the rate of flow of reflux when sphincter opens. Central obesity also induces short segment intrasphincteric reflux and thereby columnar metaplasia of the most distal oesophagus.

The role of mucin in GERD and its complications

Acid, pepsin and other noxious material reach the esophageal mucosa and interact with the luminal aspect of the squamous epithelium. The first protective barrier to these potentially injurious substances is the mucus buffer layer that covers the mucosa. In healthy people, the esophagus has a protective surface adherent mucus gel barrier. Levels of mucin glycoprotein are considerably increased in response to acid and pepsin. A wide spectrum of mucin genes are expressed in normal esophageal mucosa, squamous cell carcinoma of the esophagus, Barrett epithelium and esophageal adenocarcinoma. The mucins MUC5AC and MUC6 are expressed to a similar degree in Barrett metaplasia and gastric mucosa, as is MUC2 in Barrett intestinal metaplasia and small bowel mucosa. Increased expression of MUC1 is associated with progression from dysplasia to adenocarcinoma of the esophagus. Thus, mucins have an important role in the defense of esophageal mucosa against the acid, pepsin and bile that are present in the refluxate. Changes in the expression of mucins occur in patients with GERD, and might lead to the development of new drugs.

Significant increase of esophageal mucin secretion in patients with reflux esophagitis after healing with rabeprazole: its esophagoprotective potential

Esophageal mucin secretion in patients with reflux esophagitis (RE) is significantly impaired. Rabeprazole augments gastric mucin secretion. We have studied, therefore, the effect of rabeprazole on esophageal mucin secretion in patients with RE. The study was conducted in 15 patients with RE treated with rabeprazole (20 mg QD) for 8 weeks. Esophageal secretions were collected during consecutive infusions of initial NaCl, HCl/Pepsin (HCl/P), and a final NaCl, using a specially designed esophageal catheter, before and after therapy. Mucin was measured using standard methodology. After rabeprazole administration esophageal mucin concentration as well as secretion increased during perfusion with initial saline (P < 0.01), HCl/P (P < 0.02), and concluding saline (P < 0.001). Stimulation of esophageal mucin secretion by rabeprazole may indicate that the mechanisms governing its secretion are similar to those implicated in gastric mucin output. Enhancement of esophageal mucin secretion by rabeprazole may translate into esophagoprotective potential in patients with reflux esophagitis.

Saliva variations in gastro-oesophageal reflux disease

OBJECTIVES

The protective role of saliva in the case of oesophageal exposition to gastric acid has long been studied but some contradictions still remain. The main end-point of this study was to evaluate if a qualitative and quantitative alteration in salivary secretion exists in patients affected by GERD.

METHODS

One hundred and twenty patients (T group) with clinically and endoscopically diagnosed GERD, and 98 healthy subjects (C group) have been evaluated; salivary tests (i.e. basal flow rate, stimulated flow rate, pH, [Na(+)] and [K(+)]) were performed, socio-demographical variables and oral GERD-related symptoms were taken into account. SPSS 10.5 software was used for statistical univariate and multivariate analyses.

RESULTS

GERD patients and controls were found to have a similar basal flow rate but different stimulated salivary function [T group mean value 0.989 ml/min (+/-0.48718) vs. C group 1.2197 ml/min (+/-0.6108), pH [T group mean value 8.935 (+/-0.471) vs. C group 7.879 (+/-0.526)] and a higher K(+) concentration. In GERD patients we also registered a significant association with xerostomia [69/120 (57.5%) vs. 28/98 (28.7%)] and an oral burning sensation [58/120 (48.3%) vs. 19/98 (19.3%)].

CONCLUSIONS

Our findings assess that salivary secretion is altered in GERD patients and highlight the need for further investigations in order to define the role of saliva in the etiopathogenesis of GERD.

The oral cavity and age: a site of chronic inflammation?

Background

Aging may be accompanied by a low grade chronic up-regulation of inflammatory mediators. A variety of endogenous locally released mediators as well as inflammatory cells have been reported in the human oral cavity. The aim of this investigation was to determine the presence of different classes of inflammatory mediators in human saliva and correlate the levels with age.

Methodology and Principal Findings

Unstimulated whole buccal salivary samples were obtained in the morning from 94 healthy volunteers within 30 minutes after waking. None of the participants had taken aspirin in the week prior to the saliva collection. Lysozyme activity, eicosanoid levels (prostaglandin E₂ and leukotriene B₄) and MMP-9 activity were measured. The antimicrobial activity (lysozyme activity) was not correlated with age whereas PGE₂ levels were markedly correlated with age (r = 0.29; P<0.05; n = 56). Saliva from healthy subjects (≤40 years) compared with data derived from older volunteers (>40 years) demonstrated a significant increase in the mean values for PGE₂ and MMP-9 activity with age. In addition, significant correlations were observed between LTB₄ and PGE₂ (r = 0.28; P<0.05; n = 56) and between LTB₄ levels and MMP-9 activity in smokers (r = 0.78; P<0.001; n = 15).

Conclusions/Significance

The presence of significant levels and activity of inflammatory mediators in saliva suggests that the oral cavity of healthy subjects may be in a constant low state of inflammation associated with age.

Significant enhancement of esophageal pre-epithelial defense by tegaserod: implications for an esophagoprotective effect

BACKGROUND & AIMS

Tegaserod, a serotonin 5-hydroxytryptamine (5-HT)4 receptor agonist, is thought to stimulate intestinal secretions. The aim of the current study was to assess the effect of tegaserod vs placebo on salivary and esophageal protective factors in patients with gastroesophageal reflux disease (GERD).

METHODS

This study was a randomized, double-blind, placebo-controlled, cross-over trial in 38 GERD patients treated with tegaserod 6 mg twice a day vs placebo. Salivary samples were collected basally and during mastication. In addition, in 32 GERD patients, salivary and esophageal secretions also were collected during infusion of NaCl, HCl/pepsin, and NaCl in a consecutive fashion using a specially designed esophageal catheter. Saliva and esophageal perfusates were assessed for the pH, volume, content of buffers, protein, mucin, epidermal growth factor (EGF), transforming growth factor alpha (TGFalpha), and prostaglandin E (PGE)2 and analyzed statistically.

RESULTS

Salivary flow rates during administration of tegaserod increased over corresponding values during both basal conditions (P < .01) and mastication (P < .001). The rate of secretion of salivary bicarbonate and nonbicarbonate buffers also increased in basal conditions (P < .001 and P < .01, respectively) and during mastication (P < .05 and P = .05). Salivary EGF increased during mastication (P < .05), whereas PGE2 and TGF alpha increased in basal conditions (P < .05 and P < .01). Esophageal perfusate volumes increased during administration of tegaserod in basal conditions (P < .05), whereas esophageal EGF secretion increased after mucosal exposure to HCl/pepsin and subsequent final perfusion with NaCl (P < .05).

CONCLUSIONS

Significant stimulatory impact of 5-HT4 agonist on several salivary protective factors as well as esophageal EGF secretion may have esophagoprotective implications in patients with GERD and may help to address new therapies in the future.

The effect of chewing sugar-free gum on gastro-esophageal reflux

Regurgitated acid entering the mouth in gastro-esophageal reflux disease can cause dental erosion. Chewing gum could induce increased swallowing frequency, thus improving the clearance rate of reflux within the esophagus. The null hypothesis of this study was that chewing gum does not have any effect on the clearance of reflux from the distal esophagus. Thirty-one subjects presenting with symptoms of reflux were given a refluxogenic meal twice and were randomly selected to chew gum for half an hour after eating the meal. Esophageal pH was measured, and pH data were analyzed and compared during the postprandial periods for 2 hrs on the 2 occasions. The median (IQ range) values for the % time pH < 4 during the postprandial period without chewing gum were 5.7 (1.7-13.5) and, with chewing gum, 3.6 (0.3-7.3), respectively (p = 0.001). Chewing sugar-free gum for half an hour after a meal can reduce acidic postprandial esophageal reflux.

Tooth wear: diet analysis and advice

Diet analysis and advice for patients with tooth wear is potentially the most logical intervention to arrest attrition, erosion and abrasion. It is saliva that protects the teeth against corrosion by the acids which soften enamel and make it susceptible to wear. Thus the lifestyles and diet of patients at risk need to be analysed for sources of acid and reasons for lost salivary protection. Medical conditions which put patients at risk of tooth wear are principally: asthma, bulimia nervosa, caffeine addiction, diabetes mellitus, exercise dehydration, functional depression, gastroesophageal reflux in alcoholism, hypertension and syndromes with salivary hypofunction. The sources of acid are various, but loss of salivary protection is the common theme. In healthy young Australians, soft drinks are the main source of acid, and exercise dehydration the main reason for loss of salivary protection. In the medically compromised, diet acids and gastroesophageal reflux are the sources, but medications are the main reasons for lost salivary protection. Diet advice for patients with tooth wear must: promote a healthy lifestyle and diet strategy that conserves the teeth by natural means of salivary stimulation; and address the specific needs of the patients' oral and medical conditions. Individualised, patient-empowering erosion WATCH strategies; on Water, Acid, Taste, Calcium and Health, are urgently required to combat the emerging epidemic of tooth wear currently being experienced in westernised societies.

Dental erosion, gastro-oesophageal reflux disease and saliva: how are they related?

AIMS

The purpose of this study was to assess the prevalence of tooth wear, symptoms of reflux and salivary parameters in a group of patients referred for investigation of gastro-oesophageal reflux disease (GORD) compared with a group of control subjects.

MATERIALS AND METHODS

Tooth wear, stimulated salivary flow rate and buffering capacity and symptoms of GORD were assessed in patients attending an Oesophageal Laboratory. Patients had manometry and 24-h pH tests, which are the gold standard for the diagnosis of GORD. Tooth wear was assessed using a modification of the Smith and Knight tooth wear index. The results were compared to those obtained from a group of controls with no symptoms of GORD.

RESULTS

Patients with symptoms of GORD and those subsequently diagnosed with GORD had higher total and palatal tooth wear (p<0.05). The buffering capacity of the stimulated saliva from the control subjects was greater than patients with symptoms of GORD (p<0.001). Patients with hoarseness had a lower salivary flow rate compared with those with no hoarseness.

CONCLUSIONS

Tooth wear involving dentine was more prevalent in patients complaining of symptoms of GORD and those diagnosed as having GORD following 24-h pH monitoring than controls. Patients had poorer salivary buffering capacity than control subjects. Patients complaining of hoarseness had lower salivary flow rate than controls.

Progress with novel pharmacological strategies for gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease (GORD) is a chronic disorder characterised by an increased exposure of the oesophagus to intragastric contents. Currently, GORD symptoms are maintained under control with antisecretory agents, mainly gastric proton pump inhibitors (PPIs). Although impaired oesophageal motility may partly underlie the pathophysiology of GORD, the use of prokinetic agents has been found to be unsatisfactory. To date, novel pharmacological approaches for GORD are mainly related to the control of transient lower oesophageal sphincter (LOS) relaxations (TLOSRs). The majority of patients with GORD have reflux episodes during TLOSRs, which are evoked by gastric distension, mainly occurring after ingestion of a meal. Patients with reflux disease with normal peristalsis and without or with mild erosive disease could potentially benefit from anti-TLOSR therapy. This therapy might also be of value to treat some severe forms of esophagitis in combination with PPIs. GABA-B-receptor agonists are the most promising class of agents identified so far for TLOSR control. The GABA-B-receptor agonist, baclofen, is the most effective compound in inhibiting TLOSRs in humans. Since baclofen has several CNS adverse effects, novel orally available GABA-B agonists are needed for effective and well tolerated treatment of GORD. Endogenous or exogenous cholecystokinin (CCK) causes a reduction in LOS pressure, an increase in TLOSR frequency and a reduction in gastric emptying. In healthy volunteers and patients with GORD, loxiglumide, a selective CCK1-receptor antagonist, was found to reduce the rate of TLOSRs, although its effect on postprandial acid reflux may be modest. Orally effective CCK antagonists are not marketed to date. The anticholinergic agent atropine, given to healthy volunteers and patients with GORD, markedly reduced the rate of TLOSRs. Because of severe gastrointestinal (and other) adverse effects of anticholinergics, including worsening of supine acid clearance and constipation, it is unlikely that this class of drugs will have a future as anti-TLOSR agents on a routine basis. In spite of their effectiveness in reducing TLOSR rate, untoward adverse effects, such as addiction and severe constipation, currently limit the use of morphine and other opioid mu-receptor agonists. The same applies to nitric oxide synthase inhibitors, which are associated with marked gastrointestinal, cardiovascular, urinary and respiratory adverse effects. Animal studies provide promising evidence for the use of cannabinoid receptor 1 agonists, by showing potent inhibition of TLOSRs in the dog, thus opening a new route for clinical investigation in humans. A better understanding of TLOSR pathophysiology is a necessary step for the further development of novel drugs effective for anti-reflux therapy.

Nizatidine and cisapride enhance salivary secretion in humans

BACKGROUND

Salivation plays an important role in the defence of the oesophageal mucosa against gastric acidic reflux and can be evoked by cholinergic stimulation. Both nizatidine and cisapride have been reported to increase acetylcholine concentrations in the cholinergic system.

AIM

To investigate the effect of nizatidine and cisapride on salivary secretion, salivary epidermal growth factor and bicarbonate output.

METHODS

The salivary volume and concentration of salivary epidermal growth factor and bicarbonate were measured after the administration of nizatidine (150 mg), famotidine (20 mg) and cisapride (5 mg) in 30 male healthy volunteers.

RESULTS

Basal and stimulated salivary secretions were found to be increased after the administration of nizatidine and cisapride. In contrast, salivary secretion was not increased by famotidine. Although epidermal growth factor content was not augmented, nizatidine and cisapride administration also increased the bicarbonate output in mastication-stimulated saliva.

CONCLUSIONS

Increased salivary secretion and bicarbonate output induced by nizatidine may be useful for the treatment of patients with gastro-oesophageal reflux disease.

The oral medicine of tooth wear

This review illustrates, through a series of case histories, how oral medicine insights aid the diagnosis and management of patients with excessive tooth wear. The cases reviewed are drawn from the records of 500 southeast Queensland patients referred to the author over a 12 year period. Patients most at risk of dental erosion have work and sports dehydration, caffeine addiction, gastro-oesophageal reflux, asthma, diabetes mellitus, hypertension or other systemic diseases or syndromes that predispose to xerostomia. Saliva protects the teeth from the extrinsic and intrinsic acids which cause dental erosion. Erosion, exacerbated by attrition and abrasion, is the main cause of tooth wear. These cases illustrate that teeth, oral mucosa, salivary glands, skin and eyes should be examined for evidence of salivary hypofunction and attendant medical conditions. Based on comprehensive oral medicine, dietary analyses and advice, it would seem patients need self-management plans to deal with incipient chronic tooth wear. The alternative is the expensive treatment of pain, occlusal damage and pulp death required to repair the effects of acute severe tooth wear.

Walking and chewing reduce postprandial acid reflux

BACKGROUND

Gastro-oesophageal reflux is worse after meals, and antacids are usually consumed after dietary indiscretion.

AIM

To investigate whether walking or gum chewing affect meal-induced gastro-oesophageal reflux.

METHODS

The study population comprised 12 case subjects with gastro-oesophageal reflux disease and 24 healthy controls. Each subject was studied using pH-metry for 5 h on 3 separate days. After baseline recording of pH for 1 h, all subjects were fed a standard breakfast over a 20-min period. On one of the days, oesophageal pH was recorded after the 20-min eating period for an additional 4 h in the sitting position. On another day, postprandial oesophageal pH was recorded for the first hour whilst walking, and for 3 subsequent hours whilst sitting. During a third day, oesophageal pH was recorded for the first postprandial hour whilst gum-chewing, followed by 3 h of sitting.

RESULTS

Food intake promoted gastro-oesophageal reflux in case subjects with GERD as well as in healthy controls, although postprandial reflux was more pronounced amongst the refluxers than amongst the controls. Chewing gum for 1 h after the meal reduced the acid contact time in both groups, with a more profound effect in refluxers than in controls. Whilst the beneficial effect of 1-h of gum-chewing lasted for up to 3 h in both groups, the beneficial effect of 1-h of walking was apparent only in refluxers, only to a mild degree, and only for a short duration.

CONCLUSIONS

Chewing gum after a meal helps to reduce postprandial oesophageal acid exposure.

Salivary mucin: a factor in the lower prevalence of gastroesophageal reflux disease in African-Americans?

OBJECTIVES

Organic and inorganic constituents of saliva have been implicated as protective components in the esophagus, and deficiencies in one or more of these factors in different races may be an important element in the prevalence of gastroesophageal reflux disease (GERD). To determine whether there are differences in the concentration of salivary mucins between different racial groups, we measured the concentration of mucous glycoprotein MG1 and mucous glycoprotein MG2 in whole saliva of African-Americans and Caucasians.

METHODS

Whole saliva was collected from 19 African-American (four male, 15 female; mean age 34 yr, range 19-53 yr) and 25 Caucasian (11 male, 14 female; mean age 31 yr, range 20-51 yr) volunteers under masticatory stimulation (1 g Parafilm, 60 strokes/min) between 11:00 AM and 12:00 noon. Total salivary carbohydrate was measured with a periodic acid-Schiff assay and total protein by absorbance at 215 nm. Immunological reagents were employed to quantify MG2 in a combined enzyme-linked immunosorbent assay/enzyme linked lectin assay (ELISA/ELLA) and to quantify MG1 in a capture ELISA.

RESULTS

The total carbohydrate, protein, MG1 and MG2 values were 24.4 +/- 11.9, 243.5 +/- 62.7, 21.8 +/- 13.4, and 11.6 +/- 9.5 mg% for African-Americans, and the corresponding values were 23.3 +/- 9.3, 221.7 +/- 39.7, 25.7 +/- 16.2, and 10.9 +/- 8.7 mg% for Caucasians. There was no statistical difference for any of the parameters measured between the two groups. Furthermore, it was shown that no correlation existed between salivary flow rate and the concentration of carbohydrate, protein, or salivary mucins in African-Americans and in Caucasians. These results show that flow rate did not influence the measured values for salivary parameters in the two groups.

CONCLUSIONS

No differences were found in the concentration of salivary mucins MG1 and MG2 in whole saliva of African-Americans and Caucasians, and it seems unlikely that variations in mucin levels influence the prevalence of GERD in these groups.

Mechanisms of oesophageal mucosal defence

The integrity of the oesophageal mucosa depends upon an equilibrium between aggressive factors, predominantly acid and pepsin, and protective mechanisms. Protective mechanisms operate within the oesophageal mucosa as pre-epithelial, epithelial and post-epithelial defences. Only the protective components of the oesophageal pre-epithelial defence can be tested in vivo in humans. It has been recently demonstrated that human oesophageal submucosal glands elaborate mucous secretion rich in bicarbonate and non-bicarbonate buffers, mucin, prostaglandin E(2), epidermal growth factor (EGF) and transforming growth factor alpha (TGFalpha). This oesophageal secretion, accompanied by similarly protective factors within the swallowed saliva, defines the protective potential of the oesophageal pre-epithelial defence that exists in the form of a mucus-buffer layer covering the oesophageal mucosa and which retards the back-diffusion of hydrogen ions. It has also been demonstrated that patients with severe erosive reflux oesophagitis exhibit qualitative impairment in both the salivary and oesophageal components of the oesophageal pre-epithelial defence. Furthermore, patients with endoscopically negative gastro-oesophageal reflux disease have a significantly stronger oesophageal pre-epithelial defence than patients with erosive reflux oesophagitis. On the other hand, African-Americans, who are less likely to develop erosive reflux oesophagitis, have a stronger oesophageal pre-epithelial defence than do Caucasians. The salivary component of the oesophageal pre-epithelial defence can be enhanced by mastication and the administration of cisapride, whereas oesophageal secretion can only be significantly augmented by cisapride.

The potential role of the esophageal pre-epithelial barrier components in the maintenance of integrity of the esophageal mucosa in patients with endoscopically negative gastroesophageal reflux disease

OBJECTIVE

Patients with gastroesophageal reflux disease (GERD) accompanied by erosive reflux esophagitis (RE) exhibit an impairment within the esophageal pre-epithelial barrier protective components that may facilitate the development and/or progression of the mucosal injury. Little is known, however, whether such impairment is a general phenomenon affecting all patients with GERD or whether this is a characteristic feature only of patients with erosive RE. We therefore studied the rate of secretion of esophageal inorganic and organic protective factors in patients with endoscopically negative [E (-)] GERD and compared these results with the corresponding values in asymptomatic volunteers (CTRL).

METHODS

The study was conducted on 33 white asymptomatic volunteers and 10 white patients with a long history of GERD confirmed by 24-h pH monitoring and a grossly negative upper endoscopy. Esophageal secretion was collected during mucosal exposure to NaCl, HCl, HC/pepsin and NaCl using the esophageal perfusion catheter. In collected samples all investigated parameters were measured.

RESULTS

The pH of esophageal secretion and its content of bicarbonate, EGF, and PGE2 in patients with E (-) GERD and asymptomatic volunteers were similar. Unexpectedly, the rate of esophageal glycoconjugate (predominantly mucin) secretion was significantly higher in patients with E (-) GERD than in controls during perfusion with HCl (p < 0.05). Furthermore, secretion of protein in patients with E (-) GERD was significantly higher than in the control group during the mucosal exposure to HCl/Pepsin (p < 0.05). The nonbicarbonate buffer secretion during perfusion with HCl and HCl/Pepsin as well as the rate of esophageal TGFalpha output during infusion of final saline in patients with E (-) GERD were significantly lower than in CTRL group (p < 0.05).

CONCLUSIONS

Our data indicate that patients with E (-) GERD have an esophageal secretory potential, in terms of glycoconjugate and protein, higher than that in asymptomatic controls. This phenomenon in patients with E (-) GERD may, by enhancing the quantity of the esophageal pre-epithelial barrier, help to prevent the development of erosive esophagitis. A significantly lower esophageal secretory response in patients with E (-) GERD in terms of nonbicarbonate buffers and TGFalpha may facilitate the development of GERD symptoms and histological changes of GERD, respectively.

Salivary and gastric epidermal growth factor in patients with Zollinger-Ellison syndrome: its protective potential

OBJECTIVE

Evidence is accumulating that epidermal growth factor (EGF) is a major molecule contributing to the maintenance of the integrity of the upper alimentary tract mucosa before and after injury by acid and pepsin. Patients with Zollinger-Ellison Syndrome (ZES) typically have hypersecretion of acid and pepsin; however, the concentration and rate of secretion of salivary and gastric EGF that could counteract these potentially aggressive factors are unknown. Accordingly, this study was conducted to determine whether EGF affords mucosal protection in ZES patients.

METHODS

The concentration and output of salivary (sEGF) and gastric epidermal growth factor (gEGF) were measured in eight patients with ZES and the results compared to those in 17 patients with nonulcer dyspepsia (NUD), serving as a control group. All patients had normal esophageal and gastric mucosa as determined by endoscopy. Total saliva was collected during 1-h parafilm- and 1-h pentagastrin/parafilm-stimulated conditions, as well as basal and pentagastrin-stimulated gastric juice. The concentration and output of EGF were determined by radioimmunoassay.

RESULTS

The concentration of EGF in saliva collected from ZES patients after parafilm chewing was significantly higher compared to that in NUD patients (4.61 +/- 0.59 vs 2.75 +/- 0.50 ng/ml, p < 0.05). The concentration of EGF in saliva collected after pentagastrin stimulation in ZES patients was also significantly higher than in NUD patients (4.37 +/- 0.73 vs 2.22 +/- 0.37 ng/ml, p < 0.05). Salivary EGF output during parafilm chewing in ZES and NUD were similar (68 +/- 6.4 vs 109 +/- 25.2 ng/h). Salivary EGF output after administration of pentagastrin in ZES and NUD was also similar (66 +/- 6.1 vs 132 +/- 45.4 ng/h). Basal EGF output in the gastric juice of patients with ZES was 3-fold higher than in patients with NUD (801 +/- 73 vs 271 +/- 32 ng/h, p < 0.01). Pentagastrin-stimulated EGF output was similar in both groups (705 +/- 92 vs 675 +/- 168 ng/h).

CONCLUSIONS

Patients with ZES have a significantly higher EGF concentration in saliva and EGF output in basal gastric juice. This elevated content of salivary and gastric EGF in ZES patients may play a protective role in preventing the development of reflux esophagitis and gastric ulcer under the impact of gastric acid and pepsin hypersecretion.

Morbidity, mortality, and risk factors for esophagitis in hospital inpatients

Esophagitis is a common endoscopic finding, although its prevalence and contribution to morbidity and mortality in hospital inpatients has not been systematically evaluated. This study aimed to determine the prevalence of esophagitis among hospital inpatients referred for upper gastrointestinal endoscopy, to assess factors associated with the presence of esophagitis, and to determine the mortality of patients with esophagitis. All inpatients referred for upper gastrointestinal endoscopy in a district general hospital were assessed prospectively for one year. The reason for referral, endoscopy findings, and one-month mortality were determined together with a history of nasogastric intubation, periods spent supine, and drug use. Of 595 inpatients who underwent gastroscopy, 58% were referred for investigation of acute upper gastrointestinal bleeding. Esophagitis was found in 196 (33%). Esophagitis was significantly associated with wide-bore nasogastric intubation (p = 0.021; relative risk, 2.61; 95% CI, 0.64-6.06) but not with fine-bore nasogastric intubation. Esophagitis was also significantly associated with being nursed supine (p = 0.015; relative risk, 1.41; 95% CI, -1.75-6.72). There was no association between esophagitis and specific drug therapy. Mortality among patients with esophagitis was higher than those without esophagitis (p = 0.04; relative risk, 1.38; 95% CI, 0.34-3.22). Reflux esophagitis is common in hospital inpatients who are endoscoped. Although the underlying diseases are likely to account for the high mortality, the associations of wide-bore nasogastric intubation and being nursed supine should alert caregivers to an increased risk. If nasogastric intubation is required for feeding only, fine-bore tubes should be considered.

Diminished epidermal growth factor levels in infants with necrotizing enterocolitis

BACKGROUND/PURPOSE

Because epidermal growth factor (EGF) is trophic to the intestinal mucosa, and neonatal necrotizing enterocolitis (NEC) is associated with a disrupted intestinal mucosal barrier, the authors sought to determine whether diminished levels of EGF were present in infants with NEC.

METHODS

Saliva, serum, and urine specimens were obtained from infants with NEC during a 3-year period (February 1995 to May 1998). Control patients without NEC were chosen based on similar postnatal age and birthweight. EGF levels were determined by enzyme-linked immunosorbent assay (ELISA). Differences between groups were compared using Mann-Whitney Rank sum test with P less than .05 considered significant. Results are presented as mean values +/-SEM.

RESULTS

Twenty-five infants with NEC were compared with 19 control patients. Birth weight (1,616+/-238 g control v. 1,271+/-124 g NEC) and postnatal age (23+/-6 days control v. 22+/-3 days NEC) were similar. Infants with NEC had significantly lower levels of EGF in both saliva (590+/-80 pg/mL control v. 239+/-41 pg/mL NEC; P<.001) and serum (35+/-8 pg/mL control v. 5.6+/-1.9 pg/mL NEC; P<.001). Urinary EGF was also lower in the NEC group, but was not statistically significant.

CONCLUSIONS

Premature infants with NEC have significantly diminished levels of salivary and serum EGF. Reduced levels of this growth factor may distinguish infants at risk for NEC and play a pivotal role in the pathogenesis of the perturbed intestinal mucosal barrier that is central to this condition.

Salivary carbonic anhydrase isoenzyme VI

The carbonic anhydrases (CAs) participate in the maintenance of pH homeostasis in various tissues and biological fluids of the human body by catalysing the reversible reaction CO2 + H2O HCO3- + H+ (Davenport & Fisher, 1938; Davenport, 1939; Maren, 1967). Carbonic anhydrase isoenzyme VI (CA VI) is the only secretory isoenzyme of the mammalian CA gene family. It is exclusively expressed in the serous acinar cells of the parotid and submandibular glands, from where it is secreted into the saliva. In this review, we will discuss recent advances in research focused on the physiological role of salivary CA VI in the oral cavity and upper alimentary canal.

Noninvasive scintigraphic method to quantify unstimulated secretions from individual salivary glands

PURPOSE

Historically salivary gland function has been associated with maintenance of oral hygiene The difference in secretory behavior of parotid and submandibular glands has previously been shown. The purpose of this study was to establish a noninvasive technique for quantification of unstimulated (resting state) secretion of saliva based on the tracer output theory.

PROCEDURES

A total of 14 99mTc-pertechnetate salivary function studies were performed under Gamma camera. The time activity curves were subjected to a two step background subtraction protocol (area normalised background subtraction, followed by a graphical method for background correction). Individual salivary glands were modeled as Organ Curve = Input - Output. From these Uptake rates and unstimulated salivary gland fractional output rates (FOR) were calculated.

MAIN RESULTS

Parotid as well as submandibular glands have identical Uptake rates for the tracer. A distinct pattern was noted in submandibular glands as against parotid glands. Submandibular glands showed a steady rise in total quantity of unstimulated secretion. The FOR for submandibular glands was about three times higher than parotid glands (P< 0.000001). The observed distribution of FOR for parotid and submandibular glands FOR showed that parotid-FOR was normally on the lower side whereas submandibular-FOR showed a wide range of distribution which was multimodal in nature.

PRINCIPAL CONCLUSION

A unique approach has been presented for quantification of unstimulated salivary secretion. The method is simple and noninvasive.

Saliva and esophageal protection

There has been much interest in recent years in the potential protective role of saliva in the esophagus. Variables such as salivary volume and neutralizing capacity have been studied both during basal conditions and in response to esophageal acid exposure, in healthy subjects and in patients with esophagitis. In addition to its known neutralizing capacity, saliva also contains growth factors. These polypeptides (of which epidermal growth factor has been studied most) have cytoprotective and healing properties in various segments of the gastrointestinal tract. Therefore, a deficiency in one or more of these growth factors might be a contributing factor in the development of gastroesophageal reflux disease (GERD) or its complication, such as Barrett's metaplasia. However, human studies have produced contradictory results regarding salivary growth factor deficiency in such patients. Current methods of investigation make it difficult to assess the importance of saliva in GERD. This may be due in part to the multifactorial nature of the disease and the difficulty in long-term, selective manipulation of salivary function in humans. Given the present data in the literature, it is therefore unknown if saliva plays an important role in esophageal protection.

The distribution of endogenous epidermal growth factor after small bowel resection suggests increased intestinal utilization during adaptation

BACKGROUND/PURPOSE

Although exogenous epidermal growth factor (EGF) amplifies adaptation after massive small bowel resection (SBR), the role for endogenous EGF is unclear. The authors sought to determine whether SBR was associated with changes in the levels of EGF in the serum, saliva, or urine and EGF receptor (EGF-R) signaling in the ileum.

METHODS

Male ICR mice underwent 50% proximal SBR or sham surgery bowel transection/reanastomosis). After 3 days, levels of EGF were measured by enzyme-linked immunosorbent assay (ELISA) in the serum, saliva, and urine. EGF-R activation was measured in isolated ileal enterocytes by probing an EGF-R immunoprecipitate with an antibody to phosphotyrosine.

RESULTS

When compared with sham, SBR resulted in no change in serum, increased salivary (2209+/-266 nmol SBR v 1183+/-119 nmol sham, P<.05) and decreased urinary (417+/-58 nmol SBR v 940+/-143 nmol sham; P<.05) EGF levels. EGF-R activation increased 2.5-fold after SBR.

CONCLUSIONS

Increased salivary and reduced urinary EGF linked with enhanced EGF-R activation suggests increased ileal utilization of EGF during adaptation. This observation, along with the known beneficial effects of exogenous EGF, infers a crucial role for endogenous EGF in the pathogenesis of intestinal adaptation after SBR.

Functional gut disorders: from motility to sensitivity disorders. A review of current and investigational drugs for their management

Functional gut disorders include several clinical entities defined on the basis of symptom patterns (e.g., functional dyspepsia, irritable bowel syndrome, functional abdominal pain, functional abdominal bloating), for which there is no established pathophysiological mechanism. Because there is no well-defined pathophysiological target, treatment should be aimed at symptom improvement. Prokinetics and antispasmodics have been widely used in the treatment of functional gut disorders on the assumption that disordered motility is the underlying cause of symptoms, and symptom improvement is indeed achievable with these compounds in some, but not all, patients with features of hypo- or hypermotility, respectively. In the first part of this review, we cover the basic pharmacology and discuss the rationale for the clinical use of prokinetics and antispasmodics. On the other hand, in the past few years, the explosive growth in the research focusing on visceral sensitivity and visceral reflexes has suggested that at least some patients with functional gut disorders have altered visceral perception. Thus, the second part of the review covers these developments and focuses on studies addressing the issue of drugs modulating visceral sensitivity.

Decreased prevalence of Helicobacter pylori infection in gastroesophageal reflux disease

BACKGROUND

An increased incidence of reflux esophagitis has been reported after eradication of H. pylori in patients with duodenal ulcer. To determine if H. pylori is associated with lower rates of esophagitis, we studied the prevalence of H. pylori infection in patients with and without reflux esophagitis and a subgroup of patients with concomitant peptic ulcer disease.

METHODS

Patients who underwent esophagogastroduodenoscopy and had diagnostic testing for H. pylori over a 30-month period were studied. H. pylori infection was determined by rapid urease testing, gastric histopathology, or serology. Reflux esophagitis was determined by endoscopic and/or histologic criteria.

RESULTS

Of 514 patients, 39.5% had H. pylori infection and 22.2% had reflux esophagitis. The prevalence of H. pylori infection in patients with reflux esophagitis was 30.7%, compared with 42.0% in patients without esophagitis (p = 0.039). The odds ratio for esophagitis risk with H. pylori infection was 0.61 (95% CI, 0.39-0.95). Neither patient age nor gender affected H. pylori prevalence. In patients with duodenal ulcer, H. pylori was present in 36.4% of patients with esophagitis and in 69.2% of patients without esophagitis (p = 0.018). The odds ratio for esophagitis with H. pylori infection in these patients was 0.25 (95% CI, 0.09-0.73).

CONCLUSIONS

Our study demonstrates that H. pylori infection is significantly less prevalent in patients with reflux esophagitis and may protect against its development. In duodenal ulcer patients, this effect was more dramatic. Further study is required to confirm these findings and elucidate mechanisms underlying possible beneficial effects of H. pylori.

Role of epidermal growth factor (EGF) in oesophageal mucosal integrity

Oesophageal mucosa has well established protective mechanisms, which operate within pre-epithelial, epithelial and post-epithelial compartments. Since refluxed acid and pepsin always act from the luminal side of the mucosa, protective factors like EGF, operating as a part of pre-epithelial defence, are thought to be pivotal in the maintenance of the integrity of the oesophageal mucosa. The significant contribution of salivary EGF to the quality of the oesophageal mucosal barrier has been demonstrated in an experimental setting and in a clinical scenario. Patients with low salivary EGF levels are predisposed to severe oesophageal damage if they develop gastro-oesophageal reflux and are a high-risk group for development of Barrett's oesophagus. Not only the salivary glands but also the human oesophagus has a profound ability to elaborate and release EGF. Some changes in luminal release of EGF during oesophageal mucosal exposure to intraluminal damaging factors imply its role in the oesophageal protective mechanisms. To exert biological effects within the oesophageal mucosal compartment, EGF requires binding to the ligand-binding domain of its receptor. This process results in receptor dimerisation, autophosphorylation and activation of intracellular signal transduction pathways. EGF receptors are localised on the basolateral and luminal aspect of the mucosal cells playing an important role in fast regeneration of oesophageal epithelium through the high mitotic activity of its proliferative zone. An increase in the rate of salivary EGF secretion during masticatory stimulation suggests its potential therapeutic benefit in the treatment of patients with damaged oesophageal mucosa.