Plasma endocannabinoids and cannabimimetic fatty acid derivatives are altered in cyclic vomiting syndrome: The effects of sham feeding.

Cyclic vomiting syndrome (CVS) is an underdiagnosed disorder of the gut-brain interaction. Our understanding of the pathophysiology of CVS is evolving. Here, we tested the hypotheses that: (1) the levels of endocannabinoids and related lipids are altered in CVS, and (2) cephalic-vagal stimulation drive changes in endolipid levels. Ten adult patients with CVS and eight healthy controls were included. Indirect measurements of parasympathetic (RFa) functions were performed with spectral analysis of heart rate variability and respiratory activity. Plasma levels of endocannabinoids and related lipids were measured at baseline and during a sham feeding. Values are reported as mean ± standard error of the mean and compared using t-test or ANOVA. CVS patients had a lower parasympathetic tone and response to the Valsalva maneuver and deep breathing than the controls. The baseline 2-Arachidonoylglycerol (2-AG) had a significantly higher concentration in CVS (5.9e-008 ± 3.7e-008 mol/L) than control (3.7e-008 ± 1.3e-008 mol/; p < 0.05). Sham feeding did not change the concentration of 2-AG. 2-oleoylglycerol (2-OG) was significantly higher in CVS than control and did not change with sham feeding. Levels of N-acylethanolamines, including anandamide (AEA), were not different in CVS vs control. After sham feeding, AEA showed a trend toward increasing (p = 0.08) in CVS, but not in control. With sham feeding, palmitoyl ethanolamine significantly increased in both CVS and control groups; oleoyl ethanolamine in CVS only, and stearoyl ethanolamine in the control group. Levels of endocannabinoids and related lipids are altered in CVS patients. Sham feeding affects endogenous signaling lipids in a disease and time-dependent manner.

Gastrointestinal symptoms and the severity of COVID-19: Disorders of gut-brain interaction are an outcome.

BACKGROUND: Many of the studies on COVID-19 severity and its associated symptoms focus on hospitalized patients. The aim of this study was to investigate the relationship between acute GI symptoms and COVID-19 severity in a clustering-based approach and to determine the risks and epidemiological features of post-COVID-19 Disorders of Gut-Brain Interaction (DGBI) by including both hospitalized and ambulatory patients. METHODS: The study utilized a two-phase Internet-based survey on: (1) COVID-19 patients' demographics, comorbidities, symptoms, complications, and hospitalizations and (2) post-COVID-19 DGBI diagnosed according to Rome IV criteria in association with anxiety (GAD-7) and depression (PHQ-9). Statistical analyses included univariate and multivariate tests. RESULTS: Five distinct clusters of symptomatic subjects were identified based on the presence of GI symptoms, loss of smell, and chest pain, among 1114 participants who tested positive for SARS-CoV-2. GI symptoms were found to be independent risk factors for severe COVID-19; however, they did not always coincide with other severity-related factors such as age >65 years, diabetes mellitus, and Vitamin D deficiency. Of the 164 subjects with a positive test who participated in Phase-2, 108 (66%) fulfilled the criteria for at least one DGBI. The majority (n = 81; 75%) were new-onset DGBI post-COVID-19. Overall, 86% of subjects with one or more post-COVID-19 DGBI had at least one GI symptom during the acute phase of COVID-19, while 14% did not. Depression (65%), but not anxiety (48%), was significantly more common in those with post-COVID-19 DGBI. CONCLUSION: GI symptoms are associated with a severe COVID-19 among survivors. Long-haulers may develop post-COVID-19 DGBI. Psychiatric disorders are common in post-COVID-19 DGBI.

Achalasia: physiology and diagnosis.

Achalasia is a rare motility disorder with incomplete relaxation of the lower esophageal sphincter and ineffective contractions of the esophageal body. It has been hypothesized that achalasia does not result from only one pathway but rather involves a combination of infectious, autoimmune, and familial etiological components. On the basis of other observations, a novel hypothesis suggests that a muscular form of eosinophilic esophagitis is involved in the pathophysiology of achalasia in some patients. This appears to progressively diminish the myenteric plexus at stage III, gradually destroy it at stage II, and finally eliminate it at stage I, the most advanced and final stage of achalasia. Although high-resolution manometry has identified these three different types of achalasia, another subset of patients with a normal-appearing sphincter relaxation has been proposed. Provocative maneuvers, such as the rapid drinking challenge, have recently been demonstrated to improve diagnosis in certain borderline patients, but have to be studied in more detail. However, whether the different types of achalasia will have a long-term impact on tailored therapies is still a matter of debate. Additionally, novel aspects of the standard timed barium swallow appear to be an important adjunct of diagnosis, as it has been shown to have a diagnostic as well as a predictive value.

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.

Response to lubiprostone in chronic constipation is associated with increased mucus and mucin output: a randomized clinical trial.

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Eradication Rate of Helicobacter pylori on the US-Mexico Border Using the Urea Breath Test.

OBJECTIVES: Helicobacter pylori is prevalent worldwide, especially in Latin America. Triple and quadruple antibiotic therapies have been relatively effective; however, resistance has emerged in recent years. The treatment success rate of these regimens on the border of the United States and Mexico is unknown. Our study attempted to determine eradication rates of two major regimens based on urea breath test (UBT) results in patients previously diagnosed as having H. pylori in a single center in El Paso, Texas, a city on the geographic border with Mexico. METHODS: This was a retrospective cohort study of adult patients with H. pylori who underwent UBT after being treated with triple therapy (amoxicillin/clarithromycin/proton pump inhibitor for 14 days), quadruple therapy (tetracycline/metronidazole/bismuth/proton pump inhibitor, usually for 10 days), or both for H. pylori from 2010 to 2015 in a county hospital. Patients were excluded if they did not complete therapy or if their treatment regimen was unknown. The Student t test and the χ2 test were used to analyze the data. The cumulative incidence and 95% confidence interval (CI) for treatment success were estimated. RESULTS: A total of 104 patients completed the treatment for H. pylori and had UBT. Mean age was 53 years, 76% were women, 85% were Hispanic, and mean body mass index was 30.5 kg/m2. Of the 104 patients diagnosed as having H. pylori, 88 received triple therapy (84.6%) and 16 received quadruple therapy: 12 (11.5%) standard quadruple therapy, 4 (3.9%) triple therapy plus metronidazole. There were no differences between groups regarding age, sex, body mass index, or ethnicity. Overall, 90 (86.5%, 95% CI 78-92) patients had negative UBT after initial treatment. Based on posttreatment UBT, the triple therapy group had a similar eradication rate compared with the quadruple therapy group (78/88, 88.6% vs 12/16, 75.0%, P = 0.22). Of the 14 patients with positive posttreatment UBT, 12 (85.7%) received retreatment (2 were lost to follow-up), 11 (91.7%) received quadruple therapy, and 1 (8.3%) received triple therapy. Eradication was successful in 9 of 12 (75%, 95% CI 43-95) patients at retreatment. As such, of the initial 104 patients, 99/104 (95.2%) achieved H. pylori eradication posttreatment (either initial or retreatment). CONCLUSIONS: In a predominantly Hispanic population on the US-Mexico border, H. pylori eradication rates based on UBT results were relatively high and were similar for triple therapy and quadruple therapy. Quadruple therapy was effective for those who failed the initial H. pylori treatment. This may have implications for cost-effective therapy in our region.

Gastric pH and Therapeutic Responses to Exsomeprazole in Patients With Functional Dyspepsia: Potential Clinical Implications.

BACKGROUND: Therapy for functional dyspepsia remains a challenge. This study aimed to evaluate esomeprazole (E) versus placebo (P) regarding (1) the effectiveness in providing relief of abdominal pain or discomfort during 16 weeks of therapy in patients with functional dyspepsia having moderate or severe symptoms; (2) the effects on gastric acid suppression and (3) the relationship between symptom relief and gastric pH. METHODS: Enrolled patients were randomized to E (n = 38) or P (n = 35) in a double-blind, placebo-controlled trial. Outcomes were measured at four 4-week intervals. Drug dose titrated at each visit, based on relief of abdominal symptoms. The 24-hour gastric pH was monitored at baseline, 4 and 8 weeks. RESULTS: After 4 weeks, 71% of E patients (40mg) reported satisfactory symptom relief versus 34% of P patients (P < 0.001). When the dose for nonresponders (NR) was titrated to 40mg twice daily, the E relief rate increased to 82% versus 56% in P group (P < 0.05). During the next 4 weeks, with dose decreased by half in responders, E response rate declined to 69% versus 48% in P group (P < 0.10). When the dose was increased for NR during the last 4 weeks, E rate increased to 83% versus 57% in P group (P < 0.05). At 4 and 8 weeks for E responders and NR, patients׳ pH >4 value increased significantly compared to baseline. CONCLUSIONS: (1) Though E 40mg once daily is superior to P, some patients benefit from 40mg twice daily; (2) E, 40mg once daily, profoundly inhibits gastric acid secretion; (3) intragastric pH monitoring before and after therapy may help address the relationship between symptomatic relief and gastric acid secretion and (4) some patients respond to monitored titrated placebo therapy.

Lubiprostone Accelerates Intestinal Transit and Alleviates Small Intestinal Bacterial Overgrowth in Patients With Chronic Constipation.

BACKGROUND: Lubiprostone is an effective treatment for chronic constipation (CC). The mechanism of action of lubiprostone is through increasing fluid secretion and lubrication of the intestinal lumen. The effects of lubiprostone on gastrointestinal transit and small intestinal bacterial overgrowth (SIBO) have not been adequately explored. The current study was designed to investigate whether lubiprostone (1) alters gastrointestinal transit and (2) affects SIBO in patients with constipation. METHODS: A total of 29 female patients (mean age = 39 years; range: 19-64) with CC received 2 weeks of lubiprostone (24mcg b.i.d., P.O.). Stool consistency based on Bristol stool scale and the frequency of bowel movements (BMs) were recorded. Gastric emptying time, small bowel transit time, colon transit time (CTT), combined small and large bowel transit time (SLBTT) and whole gut transit time were measured using wireless motility capsule. The SIBO status was assessed by the lactulose breath test. Data were analyzed using Wilcoxon rank, Mann-Whitney U, Spearman׳s rank correlation and Chi-square tests. RESULTS: Lubiprostone significantly softened the stool and increased the frequency of BM from median of 2 to 4times per week. The CTT and SLBTT were significantly shorter in responders to lubiprostone (i.e., those with ≥ 2 times increase in the number of their weekly BM) compared with nonresponders. The higher frequency of BM after treatment was significantly correlated with the acceleration of CTT, SLBTT and whole gut transit time. In all, 17 out of 25 (68%) patients, who were tested for SIBO at baseline, were positive. In addition, 7 out of 17 (41%) SIBO-positive patients became SIBO-negative after lubiprostone treatment (P < 0.05). CONCLUSIONS: In CC, lubiprostone improves the frequency of BMs, softens the stool, accelerates intestinal transit and decreases accompanying SIBO. The improvement of SIBO could be explained by the cleansing effect of increased intestinal fluid and mucus combined with enhanced intestinal motility with lubiprostone.

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.

Protective Factors of the Gastric and Duodenal Mucosa: An Overview.

The structural and functional integrity of the gastric and duodenal mucosa represents equilibrium between aggressive factors and protective mechanisms. Mucus-buffers-phospholipid layer as pre-epithelial barrier, enhanced by prostaglandins and epidermal growth factor, remains a vanguard of mucosal protection. It maintains a neutral pH at the surface epithelial luminal interface, facing luminal pH dropping to 1.0, i.e., hydrogen ion concentration gradient equal 1,000,000. The surface epithelial cells, elaborating mucins, buffers, phospholipids, prostaglandins, trefoil peptides, peptide growth factor and their receptors, heat shock proteins, cathelicidins, and ß-defensins form the second line of defense. Endothelium exerts mucosal protection through production of potent vasodilators like nitric oxide and prostacyclins and through release of angiogenic growth factors, securing adequate blood flow and representing the third and an ultimate line of mucosal protection. This microcirculation is instrumental for supply of oxygen, nitric oxide, hydrogen sulfide and removal of ad hoc generated toxic substances as well as for continuous mucosal cell renewal from progenitor cells, secured by growth factors accompanied by survivin preventing early apoptosis.

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.

Glucose levels and depression in Hispanic patients admitted to the cardiovascular intensive care unit: a cross-sectional study.

Depression is frequently associated with diabetes mellitus (DM) and may worsen DM-related morbidity and mortality. We determined the potential association of glucose levels with depression in Hispanic patients admitted to the Cardiovascular Intensive Care Unit. Patients were given the Center for Epidemiologic Studies-Depression scale survey within 24 hours of admission. Glycated hemoglobin and fasting blood glucose levels within 30 days of admission were extracted. The HbA1c levels remained significantly associated with both presence of depression and depression levels. Histories of DM, myocardial infarction, and percutaneous coronary intervention as well as baseline brain natriuretic peptide levels were also significantly associated with depression levels. The presence of a significant association between glucose levels and depression in Hispanic patients indicates that there is a need for optimal management of glycemic levels. This may then lead to better health outcomes in Hispanics with cardiovascular disease.

Stimulation of Mucin, Mucus, and Viscosity during Lubiprostone in Patients with Chronic Constipation may Potentially Lead to Increase of Lubrication.

OBJECTIVES: The purpose of this clinical trial was to explore whether lubiprostone increases the rate of mucus and mucin secretion and its viscosity in chronic constipation (CC) patients. The secretion of chloride (CS) into the gastrointestinal tract lumen is pivotal in the body's ability to process non-digestible food components. CS sets the optimal rate of hydration for non-digestible food components, their fluidity, and their adequate propulsion along the alimentary tract. Chloride is also instrumental in the secretion of alimentary tract mucus, and the formation of a gel-like, viscous mucus-buffer layer. This layer acts as the first line and vanguard of the mucosal barrier. This barrier is essential in mucosal lubrication and protection. Lubiprostone, a novel chloride channel stimulator ClC-2, is currently approved for the treatment of CC. Its impact on mucus, mucus secretion, and viscosity is not established. METHODS: A double-blind, crossover trial was approved by the IRBs at the Kansas University Medical Center (Kansas City, KS) (study site) and at the Texas Tech University HSC (El Paso, TX) (analysis site). The study included 20 patients (17 females (F); mean age: 37 years) with symptoms of CC diagnosed according to the Rome III criteria. Patients were randomized to 1 week of therapy with lubiprostone or placebo followed by a 1 week washout and 1 week of the alternative therapy. Gastric juice was collected basally and during stimulation with pentagastrin (6 µg/kg body weight subcutaneously) at the end of weeks 1 and 3. Pentagastrin stimulation mimics food stimulation. The mucus content in gastric juice was assessed gravimetrically. The mucin content was measured after its purification using ultracentrifugation. The viscosity of the gastric secretion was measured using a digital viscometer. RESULTS: In comparison with placebo, the volume of gastric secretion in patients with CC during administration of lubiprostone increased significantly by 50% (86.3 vs. 57.5 ml/h) (P<0.001) in basal conditions and increased by 25% (210.0 vs. 167.6 ml/h) (P=0.024) during stimulation with pentagastrin. The rate of gastric mucus secretion during therapy with lubiprostone was 91% higher (257.3 vs. 135 mg/h) (P=0.001) in basal conditions and 28% higher (348.1 vs. 270.8 mg/h) (NS) in stimulated conditions, although the latter was not statistically significant. The rate of gastric mucin secretion during lubiprostone therapy was 85% higher (98.4 vs. 65.5 mg/h) (P=0.011) in basal conditions and 38% (98.3 vs. 71.7 mg/h) (NS) higher in stimulated conditions. In basal conditions, the viscosity of gastric secretion during administration of lubiprostone increased by 240% at the lowest (P<0.001) and by 106% at the highest shear rate (P<0.001). In stimulated conditions, it increased by 226% (P<0.01) at the lowest shear rate and by 67% (P<0.01) at the highest shear rate. CONCLUSIONS: The significantly higher content of gastric mucus and mucin during therapy in basal conditions with lubiprostone in patients with CC suggests and supports the potentially leading role of lubiprostone and ClC-2 stimulation in their secretion. This increased stimulation results in profoundly increased viscosity, which in turn facilitates and/or accelerates the transit and evacuation of non-digestible food components. Although increases in mucus and mucin were observed in stimulated conditions, neither increase was statistically significant. Based on this experiment, we hypothesize that, in CC patients, the significantly increased rate of mucus and its major component, mucin secretion, during lubiprostone administration may partially explain its clinical effectiveness and also have additional clinically important effects. We propose that since the increased mucus production enhances the protective quality of the mucosal barrier, it also boosts its potential to withstand luminal aggressive components such as acid/pepsin duet, Helicobacter pylori and/or nonsteroidal anti-inflammatory drugs/aspirin, or a combination of all. Further trials are needed to test this hypothesis. As this was crossover clinical trial, the patients serve as their own controls. No interaction was found with body mass index (BMI) and treatment. The observed relationships of BMI and mucus and mucin secretions and gastric juice volume are important considerations in the design of future trials, particularly if a crossover design is not used.

Benign and precursor lesions in the esophagus.

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on the role of salivary stimulation and esophageal secretion of protective factors in prevention of adenocarcinoma sequelae in gastroesophageal reflux disease; the pediatric conditions associated with esophageal cancer; the relationship of achalasia and pseudoachalasia with esophageal cancer; the potential for malignant transformation in eosinophilic esophagitis and overlap syndromes; the role of lymphocytic esophagitis as an overlapping phenotype; the role of Barrett's esophagus as a premalignant condition; the indications and type of treatment of premalignant conditions of the esophagus; and the decision for use of endoscopical procedures in premalignant conditions of the esophagus.

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.

Impaired viscosity of gastric secretion and its mucin content as potential contributing factors to the development of chronic constipation.

BACKGROUND: The alimentary tract mucosa continuously releases mucus-rich secretion. Mucin, the major component of mucus, determines its viscosity and provides lubrication for the luminal content of indigestible food particles. AIMS: To measure mucin secretion rate and its viscosity in patients with chronic constipation (CC) and in asymptomatic volunteers. METHODS: Nineteen patients with symptoms of CC and 19 controls were included in the study. Mucin secretion and viscosity were assessed in aspirated gastric juice in basal conditions and after stimulation with pentagastrin (1 h each). Mucin content was tested by PAS methodology. Viscosity was measured using cone/plate digital viscometer. RESULTS: Mucin secretion rates in basal and stimulated conditions in controls were 65 and 42 % higher than in patients with CC (P < 0.05 and P < 0.001, respectively). Basal viscosity in controls was 48 % higher than in CC (P < 0.05) at the lowest and 55 % higher (P < 0.05) at the middle velocities. Viscosity in pentagastrin-stimulated conditions in controls was 71 % higher than in CC (P < 0.01) at the lowest and 35 % higher (P < 0.05) at the middle velocities. CONCLUSIONS: (1) The significantly lower rate of soluble mucin secretion in patients with CC than in normal volunteers may reflect impairment in mucin-related lubrication. (2) Significantly lower viscosity of gastric secretion in patients with CC may result from the lower rate of mucin secretion and may also diminish lubrication within the alimentary tract. (3) This may potentially set the stage for the development of symptoms related to chronic constipation and open a new therapeutic avenue for this patient population.

Salivary bicarbonate as a major factor in the prevention of upper esophageal mucosal injury in gastroesophageal reflux disease.

BACKGROUND: It has been previously demonstrated that the exposure of the lower esophageal mucosa to acid and pepsin results in significant increase in salivary protective factors secretion, mediated by the esophago-salivary reflex. The impact of the upper esophageal mucosal exposure to acid and pepsin on salivary secretory response remains unknown. AIMS: To investigate the rate of salivary protective factors secretion during the upper esophageal mucosal exposure to acid and pepsin and to compare with the corresponding results recorded during the lower esophageal mucosal exposure, in the same group of asymptomatic volunteers. METHODS: The study was conducted in 10 asymptomatic volunteers. Salivary samples were collected during the esophageal mucosal exposure to saline, followed by acid/pepsin and the final saline, using the esophageal perfusion catheter. Salivary bicarbonate and non-bicarbonate buffers were analyzed using TitraLab. Salivary mucin and protein were quantified through PAS and Lowry methodologies, respectively, whereas PE2 using radioimmunoassay. Statistical analysis was performed using Σ-Stat software. RESULTS: The rate of salivary bicarbonate secretion was significantly higher (3.1-fold) during the upper versus the lower esophageal mucosal exposure to acid and pepsin (87.5 ± 14.4 vs. 28.0 ± 7.70 µEq/min, p < 0.05). The volumes of saliva, pH, salivary protein, mucin and PE2 were similar in both esophageal perfusions. CONCLUSIONS: Threefold stronger secretion of salivary bicarbonate could be a major factor protecting the upper esophageal mucosa. This phenomenon may represent an ultimate defense mechanism potentially preventing further complications within the upper esophageal mucosa; however, it needs to be confirmed in patients of gastroesophageal reflux disease.

Depression as a predictor of length of stay in patients admitted to the cardiovascular intensive care unit at a university medical center.

Depression is a predictor of length of stay (LOS) and adverse outcomes in patients with cardiac disease. Our objective was to assess the impact of depression on LOS in a Hispanic population admitted to a cardiovascular intensive care unit (CVICU). This was a prospective study of 151 consecutive patients admitted to the CVICU. Patients were administered the Center for Epidemiologic Studies Depression (CES-D) scale survey within 24 hours of admission. Patients were followed until discharge to determine LOS and adverse outcomes. Depression was more prevalent in Hispanic patients than in nonHispanic patients based on the CES-D scores (41% vs 14%). Using multivariate analysis, the presence of depression was a significant predictor of increased LOS (P = .001). Depression has a significant impact on LOS in a Hispanic population. Appropriate treatment of depression may decrease LOS and has the potential to be cost effective in the current health care environment.

Impairment of salivary mucin production resulting in declined salivary viscosity during naproxen administration as a potential link to upper alimentary tract mucosal injury.

OBJECTIVES: Nonsteroidal anti-inflammatory drugs (NSAIDs) contribute to the esophageal mucosal injury through its direct topical impact on the luminal aspect of the surface epithelium. Its indirect, systemic impact, however, on salivary component of the esophageal pre-epithelial barrier remains to be explored. Therefore, salivary mucin secretion and viscosity at baseline and during naproxen-placebo, as well as naproxen-rabeprazole, administration were investigated. METHODS: Twenty-one asymptomatic volunteers were included in this double-blind, placebo-controlled, crossover designed study. Salivary samples were obtained in basal and pentagastrin-stimulated conditions (6 mg/kg s.c.) mimicking the food-stimulated conditions. Patients received 7 days of naproxen-placebo or naproxen-rabeprazole with a 2-week washout period in between. Salivary mucin content and viscosity were measured before and after treatment using periodic acid/Schiff's methodology and Cone/Plate Digital Viscometer, respectively. RESULTS: The rate of salivary mucin secretion in basal condition declined by 32% during administration of naproxen-placebo (11.3±1.7 vs. 16.8±3.3 mg/h). Salivary mucin secretion in pentagastrin-stimulated condition declined significantly (by 34%) during the administration of naproxen-placebo (13.6±1.5 vs. 20.7±3.0 mg/h; P<0.05). Viscosity significantly decreased after naproxen-placebo administration in basal (by 60%) and stimulated conditions (by 56%) (P<0.001). Coadministration of rabeprazole at least partly restored the naproxen-induced decline of salivary mucin in basal condition (by 8%), and pentagastrin-stimulated conditions (by 30%). CONCLUSIONS: A significant decline of salivary mucin and viscosity during administration of naproxen may at least partly explain a propensity of patients on chronic therapy with NSAIDs to the development of esophageal mucosal injury and complications. In addition the trend to restorative capacity of rabeprazole on the quantitative impairment of salivary mucin during administration of naproxen may potentially translate into its tangible clinical benefit but it requires further investigation.

Gender and estradiol as major factors in the expression and dimerization of nNOSα in rats with experimental diabetic gastroparesis.

BACKGROUND: The molecular mechanisms of cellular changes responsible for diabetic gastroparesis, primarily seen in middle-aged women, still remain incompletely defined. We hypothesized that a decrease in the expression, dimerization, and post-translational modification of neuronal nitric oxide synthase alpha (nNOSα) is estrogen mediated and responsible for the gender-specific prevalence of this malady. METHODS: We induced diabetes by injecting male and female rats with streptozotocin. Male diabetic rats without gastroparesis were then injected with estrogen for 3 weeks and evaluated for gastroparesis development. Gastric tissues were analyzed for the elucidation of biochemical events associated with diabetes and gastroparetic dysfunction. RESULTS: Although male diabetic, gastroparetic (either streptozotocin- or estrogen-induced) rats exhibited similarity in disease pathology to that of females, the molecular mechanisms of development were different. Our results indicate that slow gastric emptying in both male diabetic, gastroparetic rat groups was not associated with the level of expression of nNOSα in gastric tissues. However, nNOSα dimerization, which reflects nNOSα activation, did decline slightly in the antrum of diabetic males with estrogen-induced gastroparesis, suggesting a possible estrogen role. Females with diabetic gastroparesis, in contrast, demonstrated significantly impaired levels and dimerization of nNOSα in the antrum and pylorus. Although the precise mechanism remains unknown, nNOSα dimerization impairment in female antrum is apparently associated with reduced phosphorylation of Ser(1416) in the activation loop of nNOSα. CONCLUSION: Taken together, these results demonstrate that gender and estrogens may be leading factors, through molecular changes involved in nitric oxide synthesis down-regulation, within the antrum and pylorus of female diabetic, gastroparetic rats.