Xuanfu Daizhe Tang alleviates reflux esophagitis in rats by inhibiting the STAT1/TREM-1 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Reflux esophagitis (RE) is a common chronic inflammatory disease of the esophageal mucosa with a high prevalence and recurrence rate, for which a satisfactory therapeutic strategy is still lacking. Chinese medicine has its characteristics and advantages in treating RE, and the clinical application of Xuanfu Daizhe Tang (XDT) in treating RE has achieved sound therapeutic effects. However, there needs to be more research on its mechanism of action.

AIM OF THE STUDY

The present work aimed to investigate the mechanism of XDT action in RE through the Signal Transducer and Activator of Transcription 1 (STAT1)/Triggering Receptor Expressed on Myeloid cells-1 (TREM-1) pathway.

MATERIALS AND METHODS

The main active components of XDT were analyzed by ultra-performance liquid chromatography-mass spectrometer (UPLC-MS). The effect of XDT on RE was evaluated in a rat model of RE induced by "Cardioplasty + pyloric ligation + Roux-en-Y esophagojejunostomy". Each administration group was treated by gavage. The degree of damage to the esophageal mucosa was evaluated by visual observation, and the Potential of Hydrogen (PH) method and Hematoxylin-eosin staining (HE) staining were performed. Serum levels of Interleukin-1β (IL-1β), Interleukin-6 (IL-6), Tumor Necrosis Factor alpha (TNF-α), and Inducible Nitric Oxide Synthase (iNOS) were measured by ELISA. Quantitative Real-time PCR (qPCR), Western Blot (WB), and Immunofluorescence (IF) methods were used to detect Claudin-4, Claudin-5, TREM-1, and p-STAT1 in esophageal tissues for studying the mechanism of action and signaling pathway of XDT. Immunohistochemistry (IHC) analysis was used to detect the expression of TREM-1 and CD68 in esophageal tissues. Flow Cytometry (FC) was used to detect the polarization of macrophages in the blood. After conducting preliminary experiments to verify our hypothesis, we performed molecular docking between the active component of XDT and STAT1 derived from rats and parallel experiments with STAT1 inhibitor. The selective increaser of STAT1 transcription (2-NP) group was used to validate the mechanism by which XDT acts.

RESULTS

XDT alleviated esophageal injury and attenuated histopathological changes in RE rats. XDT also inhibited the inflammatory response and decreased serum IL-1β, IL-6, TNF-α, and iNOS levels in RE rats. qPCR and WB results revealed that XDT inhibited the expression of Claudin-4, Claudin-5, TREM-1, and STAT1 in the esophageal mucosa of RE rats. IHC and FC results showed that XDT reduced TREM-1 levels in esophageal tissues and polarized macrophages toward M2. The molecular docking results showed that rat-derived STAT1 can strongly bind to Isochronogenic acid A in XDT. The parallel experimental results of STAT1 inhibitor showed that XDT has anti-inflammatory effects similar to STAT1 inhibitors. The 2-NP group confirmed that XDT exerts its therapeutic effect on reflux esophagitis through the STAT1/TREM-1 pathway, with STAT1 as the upstream protein.

CONCLUSIONS

This study suggests that XDT may treat reflux esophagitis by modulating the STAT1/TREM-1 pathway.

A thin layer of sucrose octasulfate protects the oesophageal mucosal epithelium in reflux oesophagitis

Sucralfate is effective for the treatment of gastric and duodenal ulcers owing to its protective gel-forming ability. However, the mechanism by which sucralfate protects the oesophageal mucosa against reflux oesophagitis has not been clarified. We aimed to investigate the mechanisms of action of sucralfate and sucrose octasulfate (SOS), a component of sucralfate. SOS and sucralfate were administered to oesophagitis-induced rats, and the ulcer lesion size was macroscopically examined and scored. Effective pepsin activity in the gastric juices obtained from the animal model was evaluated by a casein digestion test. Sucralfate and SOS improved the pathology scores in a dose-dependent manner, whereas gastric juice pepsin activity was not impaired by therapeutic doses of SOS. As SOS lacks the ability to form a thick gel layer by polymerisation, we examined the distribution of SOS in the mucosal lumen by imaging mass spectrometry (IMS) to determine whether SOS directly adheres to the mucosal surface. A clear homogeneous thin-layer SOS film (>100 μm thick) was visualized on the oesophageal mucosal surface. Moreover, this SOS film formation was enhanced at ulcer lesion sites. Taken together, SOS appears to protect oesophageal mucosa against reflux oesophagitis via thin-layer formation on the mucosal surface.

The effect of n-3/n-6 polyunsaturated fatty acids on acute reflux esophagitis in rats

BACKGROUND

Polyunsaturated fatty acids (PUFAs) play various roles in inflammation. However, the effect of PUFAs in the development of reflux esophagitis (RE) is unclear. This study is to investigate the potential effect of n-3/n-6 PUFAs on acute RE in rats along with the underlying protective mechanisms.

METHODS

Forty Sprague Dawley rats were randomly divided into four groups (n = 10 in each group). RE model was established by pyloric clip and section ligation. Fish oil- and soybean oil-based fatty emulsion (n-3 and n-6 groups), or normal saline (control and sham operation groups) was injected intraperitoneally 2 h prior to surgery and 24 h postoperatively (2 mL/kg, respectively). The expressions of interleukin (IL)-1β, IL-8, IL-6 and myeloid differentiation primary response gene 88 (MyD88) in esophageal tissues were evaluated by Western blot and immunohistochemistry after 72 h. The malondialdehyde (MDA) and superoxide dismutase (SOD) expression in the esophageal tissues were determined to assess the oxidative stress.

RESULTS

The mildest macroscopic/microscopic esophagitis was found in the n-3 group (P < 0.05). The expression of IL-1β, IL-8, IL-6 and MyD88 were increased in all RE groups, while the lowest and highest expression were found in n-3 and n-6 group, respectively (P < 0.05). The MDA levels were increased in all groups (P < 0.05), in an ascending trend from n-3, n-6 groups to control group. The lowest and highest SOD levels were found in the control and n-3 group, respectively (P < 0.05).

CONCLUSION

n-3 PUFAs may reduce acute RE in rats, which may be due to inhibition of the MyD88-NF-kB pathway and limit oxidative damage.

Toll-like Receptor 2 Signalling and the Lysosomal Machinery in Barrett's Esophagus

BACKGROUND AND AIMS

Inflammation plays an important role in the development of esophageal adenocarcinoma and its metaplastic precursor lesion, Barrett's esophagus. Toll-like receptor (TLR) 2 signalling and lysosomal function have been linked to inflammation-associated carcinogenesis. We examined the expression of TLR2 in the esophagus and the effect of long-term TLR2 activation on morphological changes and expression of factors involved in lysosomal function in a Barrett's esophagus epithelium cell line.

METHODS

TLR2 expression in normal squamous esophagus, reflux esophagitis, Barrett's esophagus and esophageal adenocarcinoma biopsies was assessed with Q-RT-PCR, in situ hybridization and immunohistochemistry. Barrett's esophagus epithelium cells (BAR-T) were incubated with acid and bile salts in the presence or absence of the TLR2 agonist Pam3CSK4 for a period up to 4 weeks. Morphological changes were assessed with electron microscopy, while Q-RT-PCR was used to determine the expression of lysosomal enzymes (Cathepsin B and C) and factors involved in endocytosis (LAMP-1 and M6PR) and autophagy (LC3 and Rab7).

RESULTS

TLR2 was expressed in normal squamous esophagus, reflux esophagitis, Barrett's esophagus but was most prominent in esophageal adenocarcinoma. Long-term TLR2 activation in acid and bile salts exposed BAR-T cells resulted in more and larger lysosomes, more mitochondria and increased expression of LAMP-1, M6PR, Cathepsin B and C when compared to BAR-T cells incubated with acid and bile salts but no TLR2 agonist. Factors associated with autophagy (LC3 and Rab7) expression remained largely unchanged.

CONCLUSION

Activation of TLR2 in acid and bile salts exposed Barrett epithelium cells resulted in an increased number of mitochondria and lysosomes and increased expression of lysosomal enzymes and factors involved in endocytosis.

[Effect of aluminum phosphate gel and Kangfuxin on esophageal pathology and IL-8 and PGE2 expressions in a rat model of reflux esophagitis]

OBJECTIVE

To explore the effect of aluminum phosphate gel and Kangfuxin on esophageal pathology and expressions of interleukin-8 (IL-8) and prostaglandin E2 (PGE2) in rats with reflux esophagitis and explore the possible mechanisms.

METHODS

Sixty SD rats were randomized into aluminum phosphate gel group (n=10), Kangfuxin group (n=10), aluminum phosphate gel+Kangfuxin group (n=10), model group (n=20), and control group (n=10). Except for those in the control group, all the rats were subjected to infusion of diluted lysolecithin with hydrochloric acid in the esophagus for 14 days. Ten rats in the model group and those in the control group were sacrificed to examine the pathological changes and contents of IL-8 and PGE2 in the esophagus using optical and electron microscopes and radioimmunoassay. The next day the rest rats were given corresponding treatments (saline in model group) administered into the esophagus on a daily basis for 14 days, after which esophageal pathologies and IL-8 and PGE2 contents were examined.

RESULTS

The model rats showed obvious esophageal pathologies including inflammatory cell infiltration, vacuolar degeneration of the epithelial cells, esophageal erosion and even ulceration, with severe detachment of the epithelial cells. The rats in all the intervention groups showed lessened esophageal pathologies and lowered esophageal IL-8 and PGE2 contents compared with those in the model group. Esophageal mucosal injury index and IL-8 and PGE2 contents were all significantly lower in rats receiving combined treatment with aluminum phosphate and Kangfuxin than in those receiving either of the treatments (P<0.05).

CONCLUSIONS

Both Kangfuxin and aluminum phosphate gel are effective in the treatment for reflux esophagitis induced by lysolecithin and hydrochloric acid, and their therapeutic effects are achieved possibly by reducing IL-8 and PGE2 levels in the esophagus.

[DAILY INTRAESOPHAGEAL pH-MONITORING IN THE DIAGNOSIS OF THE SEVERITY OF ESOPHAGITIS WITH GASTROESOPHAGEAL REFLUX DISEASE]

OBJECTIVE

To identify criteria of pH-grams to diagnose the severity of esophagitis and preneoplastic complications of GERD.

MATERIALS AND METHODS

63 patients aged from 18 to 70 with A, B, C degree of GERD, according to the Los Angeles classification and 15 patients with intestinal metaplasia of columnar epithelium and leukoplakia of the stratified squamous epithelium of the esophagogastric transition were examined. For daily intraesophageal pH-monitoring "Gastroscan-24", pH probes manufactured by ZAO NPP "Istok- system", Fryazino (Russia) were used. pH-grams were estimated according for indicators DeMeester. Endoscopy was performed by videoesofagogastroscopes of Evis Exera- system--160 and by the tools company "Olympus" (Japan).

RESULTS

5 options of pH-grams were selected, each of them may correspond to some degree of esophagitis, preneoplastic changes of the esophageal mucosa, esophageal and extraesophageal manifestations of GERD.

CONCLUSION

Daily pH-monitoring of the esophagus can serve as a screening for the severity of esophagitis, preneoplastic changes of esophagogastric transition, for addressing the need of morphological studies and differential diagnosis of extraesophageal manifestations of GERD.

Esophagoprotective activity of angiotensin-(1-7) in experimental model of acute reflux esophagitis. Evidence for the role of nitric oxide, sensory nerves, hypoxia-inducible factor-1alpha and proinflammatory cytokines

Gastroesophageal reflux disease (GERD) is a global disease rapidly increasing among world population. The pathogenesis of reflux esophagitis which is considered as the early stage of GERD is complex, resulting from an imbalance between aggressive factors damaging the esophagus and a number of the natural defense mechanisms. The esophageal mucosa is in a state of continuous exposure to potentially damaging endogenous and exogenous factors. Important aggressive components of gastric refluxate include acid and pepsin and also pancreatic enzymes and bile. Among aggressive factors of exogenous origin, cigarette smoking, non-steroidal anti-inflammatory drugs (NSAID), and steroids are of the utmost importance. The basic level of esophageal defense against acid-pepsin damage consists of the anti-reflux mechanisms such as the luminal acid clearance and removal of the esophageal contents and neutralization of luminal acidity. In addition the esophageal mucosal protection includes the presence of pre-epithelial, epithelial and post-epithelial cellular and functional components. Recently, the progress have been made in the understanding of role of the heptapeptide member of the renin-angiotensin system (RAS), angiotensin-(1-7) (Ang-(1-7)) in the control of gastrointestinal functions. It has been shown that all components of local RAS including Ang-(1-7) are detectable in the gastrointestinal wall including not only the stomach but also the esophagus. Previous studies revealed that Ang-(1-7), which is an important component of the RAS, exerts vasodilatory, anti-inflammatory and antioxidant activities in the stomach. Ang-(1-7) was recently implicated in gastroprotection, but its effects on esophageal mucosa in a rodent model of reflux esophagitis and in human subjects presenting GERD symptoms have not been explored. The present study was aimed to evaluate the possible protective effects of Ang-(1-7) and Mas-receptors upon esophageal mucosal damage in acute reflux esophagitis (RE) induced in anesthetized rats by ligating the pylorus and the limiting ridge (a transitional region between the forestomach and the corpus of stomach). Consequently, the total gastric reservoir to store gastric juice was greatly diminished, resulting in the reflux of this juice into the esophagus. Because Mas receptors are functionally linked to nitric oxide (NO) formation, we also studied involvement of endogenous NO in the mediation of protective and circulatory effects of exogenous Ang-(1-7). Moreover, an attempt was made to assess the possible role of sensory neurons in the modulation of the protective effects exerted by Ang-(1-7)/Mas receptor system. Six series of rats were pretreated 30 min before induction of RE with 1) vehicle (saline), 2) Ang-(1-7) (5-50 μg/kg i.p.), 3) A779 (50 μg/kg i.p.), the selective Mas receptor antagonist applied alone, 4) Ang-(1-7) (50 μg/kg i.p.) combined with A779, 5) L-NNA (20 mg/kg i.p.) administered alone, and 6) Ang-(1-7) (50 μg/kg i.p.) combined with L-NNA. In separate group of rats, capsaicin (total dosage of 125 mg/kg within three days) was administered s.c. 2 weeks before the induction of RE to induce functional ablation of sensory nerves. Rats with intact sensory nerves and those with capsaicin-induced sensory denervation received vehicle (saline) or Ang-(1-7) (50 μg/kg i.p.) to determine whether this vasoactive metabolite of angiotensin I could be also effective in rats with capsaicin-induced impairment of the synthesis and release of sensory neuropeptides such as CGRP. Four hours after induction of RE, the mucosal damage was graded with mucosal lesion index (LI) from 0 to 6, the esophageal microcirculatory blood flow (EBF) was determined by H2-gas clearance technique and plasma level of pro-inflammatory cytokines interleukin-1b (IL-1β), and tumor necrosis factor-α (TNF-α) was determined by ELISA. The expression of proinflammatory factors including COX-2, cytokine IL-1β and hypoxia inducible factor 1alpha (Hif1α) was analyzed in the esophageal mucosal biopsies. In rats with RE, the esophageal LI was significantly elevated comparing its value observed in intact rats, and the EBF was significantly decreased as compared with intact mucosa. Pretreatment with Ang-(1-7) of control rats without esophagitis induced increase in EBF by about 25% without any macroscopic changes in the esophageal mucosa or in the plasma level of cytokines. In animals with RE, pretreatment with Ang-(1-7) significantly reduced gross and histological esophageal mucosal injury and significantly increased EBF in comparison to vehicle-pretreated animals. The observed gross and histologic esophagoprotective effect of Ang-(1-7) was totally abolished by A779 so in rats with combined treatment of A779 with Ang-(1-7), the LI was identical with this observed in control RE and the EBF was decreased in these animals by about 39%. Inhibition of NO synthase by L-NNA significantly reduced the LI and the rise in EBF caused by Ang-(1-7). Similarly, the capsaicin denervation also significantly attenuated the vasodilatory and the esophagoprotective effects of Ang-(1-7). The expression of proinflammatory factors COX-2, Hif1α and IL-1β which was negligible in intact esophageal mucosa, was upregulated in esophageal mucosa of rats with RE. In contrast, the administration of Ang-(1-7) resulted in a downregulation of mRNA for COX-2, Hif1 and IL-1β in esophageal mucosa an this effect was abolished in A779-dependent manner. The Ang-(1-7) significantly decreased the RE-induced elevation of plasma levels of IL-1β and TNF-α, and this effect was also reversed by pretreatment with A779, and significantly attenuated by pretreatment with L-NNA and capsaicin-induced sensory denervation. The present study indicates that the protective effect of Ang-(1-7) observed in the esophageal mucosa during early acute stage of gastroesophageal reflux depends upon the enhancement of esophageal microcirculatory blood flow via the activation of Mas receptor possibly due to NO synthase/NO system activation, stimulation of sensory nerves, the inhibition of expression of pro-inflammatory factors including COX-2, Hif1α and IL-1β and release of proinflammatory cytokines IL-1β and TNF-α.

Esophageal Helicobacter pylori colonization aggravates esophageal injury caused by reflux

AIM: To investigate esophageal Helicobacter pylori (H. pylori) colonization on esophageal injury caused by reflux and the related mechanisms.

METHODS: An esophagitis model, with acid and bile reflux, was surgically produced in male rats. The rats were randomly divided into either: (1) an esophagogastroduodenal anastomosis (EGDA) group; (2) an EGDA with H. pylori infection group; (3) a pseudo-operation with H. pylori infection group; or (4) a pseudo-operation group. All rats were kept for 36 wk. Based on the location of H. pylori colonization, the EGDA rats with H. pylori infection were subdivided into those with concomitant esophageal H. pylori colonization or those with only gastric H. pylori colonization. The esophageal injuries were evaluated grossly and microscopically. The expressions of CDX2 and MUC2 were determined by real-time polymerase chain reaction (RT-PCR) and immunohistochemistry. Ki-67 antigen expression was determined by immunohistochemistry. The mRNA levels of cyclin D1, c-Myc, Bax and Bcl-2 were determined by RT-PCR. Cell apoptosis was evaluated using the TdT-mediated dUTP nick-end labeling method.

RESULTS: Esophagitis, Barrett’s esophagus (BE), and esophageal adenocarcinoma (EAC) developed in rats that underwent EGDA. When comparing rats with EGDA and concomitant esophageal H. pylori colonization to EGDA-only rats, the severity of injury (87.9 ± 5.2 vs 77.2 ± 8.6, macroscopically, 92.5 ± 8.0 vs 83.8 ± 5.5, microscopically, both P < 0.05) and the incidences of BE (80.0% vs 33.3%, P = 0.055) and EAC (60.0% vs 11.1%, P < 0.05) were increased. These increases were associated with upregulation of CDX2 and MUC2 mRNA (10.1 ± 5.4 vs 3.0 ± 2.9, 8.4 ± 4.6 vs 2.0 ± 3.2, respectively, Ps < 0.01) and protein (8.1 ± 2.3 vs 3.3 ± 3.1, 7.3 ± 4.0 vs 1.8 ± 2.7, respectively, all P < 0.05). The expression of Ki-67 (8.9 ± 0.7 vs 6.0 ± 1.7, P < 0.01) and the presence of apoptotic cells (8.3 ± 1.1 vs 5.3 ± 1.7, P < 0.01) were also increased significantly in rats with EGDA and concomitant esophageal H. pylori colonization compared with rats with EGDA only. The mRNA levels of cyclin D1 (5.8 ± 1.9 vs 3.4 ± 1.3, P < 0.01), c-Myc (6.4 ± 1.7 vs 3.7 ± 1.2, P < 0.01), and Bax (8.6 ± 1.6 vs 5.1 ± 1.3, P < 0.01) were significantly increased, whereas the mRNA level of Bcl-2 (0.6 ± 0.3 vs 0.8 ± 0.3, P < 0.01) was significantly reduced in rats with EGDA and concomitant esophageal H. pylori colonization compared with rats with EGDA only.

CONCLUSION: Esophageal H. pylori colonization increases esophagitis severity, and facilitates the development of BE and EAC with the augmentation of cell proliferation and apoptosis in esophageal mucosa.

New insight into oseophageal injury and protection in physiologically relevant animal models

Chronic diseases of lifestyle (CDL), the most common chronic group of non-infectious and non-transmissible diseases worldwide, which share the similar risk factors of unhealthy lifestyle, have become most recognized as a serious trigger in the genesis of oesophageal injury. Non-erosive oesophageal lesions (NEOL) are found more frequently than erosive or ulcer lesions in patients with reflux oesophagitis (RO) related to CDL. They also have restricted healing options, which often leads to carcinogenesis. Therefore, developing a physiologically relevant animal model of NEOL remains an urgent priority. One of triggers of CDL, postprandial hyperglycemia (PHG), which is characterized by hyperglycemic spikes, and overloading nitro-compounds leading to oxidative stress that may predispose to NEOL. The present study was designed to set up a model of RO related to CDL in rodents to understand mechanisms of oesophageal preulcerogenic injury under such conditions as food-associated long-term PHG, restrained water-immersion stress (WIS), and imbalance of entero-salivary nitrites recirculation (ESNR). Beneficial effects of L-tryptophan (L-Try) have already been described by many activities in kynurenine and melatonin (Mel) synthesis, redox reactions, which play a key role for cytoprotection and proliferation. Nevertheless, the effect of L-Try and Mel on NEOL under PHG is still unknown. An extract of Cucurbita maxim sweet seed (eCMS), which contains a high amount of antioxidants, also appear to play an important role in foregut cytoprotection. Thus, the second aim was to observe the effects of eCSE on oesophageal mucosa (OEM) in modification of ESNR (mESNR). Rats were used with without/with pre-treatment L-Try, Mel during WIS and PHG. In the second series of experiments rats were used with without/with CSE pre-treatment in mESNR; oral and OEM lesions were determined by histology; inflammation of OEM by lectin histochemistry; esophageal NO2(-), cNOS and iNOS via bioassays; interleukin 1β (IL-1β), interleukin-8 (IL-8) via ELISA. PHG caused destructive lesions in the OEM accompanied by the up-regulation of iNOS and down-regulation of cNOS expressions, excessive NO2(-) while COX significantly aggravated the severity of these lesions; L-Try prevented ulcerogenic response to PHG with potent up-regulation of cNOS but did not affect synthesis NO2(-). Mannose (Man)-containing specific a-DMan glycoconjugates labelled by lectins GNA, PSL, LCA, ConA and fucose (Fuc)-rich Fuc-α1 glycoconjugates - PFA, LABA are contributed in OEM integrity. It was shown that the changes of subepithelial and epithelial structures labelled by GNA, PSL, LCA displayed their highest exposure in the surface layer, whereas in the intima of microvasculature and nerve fibres of serosa membrane of the oesophagus by ConA during PHG NEOL. Also, the overexpression of Fuc glycans was present in OEM pre-epithelial and epithelial layers labelled by LABA and in the epithelial-glial-endothelial activity by PFA. Thus, initial changes in endothelial metabolism via iNOS and eNOS can be diagnostic and prognostic markers of NEOL in RO. Our mESNR studies also documented an early increase in pro-inflammatory mediators in the initial stage of oesophageal ulcerogenesis and repair and it can be a model for both proximal and distal oesophageal reflux diseases, as determinate by NEOL in oral mucosa and OEM. These findings suggest that endothelial metabolism is deeply involved in pathogenesis of NEOL. These models may be useful for detecting a new therapeutic strategy NERD, testing anti-ulcer drugs against RO and impaired healing OEM. Our results suggest that L-Try and Mel prevent OEM damage inducted by PHG and oesophagoprotective effect via modulation NO/NOS activity. The anti-inflammatory effect of eCMS could be used to protect oral mucosa and OEM against mESNR.

Association of esophageal inflammation, obesity and gastroesophageal reflux disease: from FDG PET/CT perspective

OBJECTIVE

Gastroesophageal reflux disease (GERD) is associated with bothersome symptoms and neoplastic progression into Barrett's esophagus and esophageal adenocarcinoma. We aim to determine the correlation between GERD, esophageal inflammation and obesity with 18F-Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT).

METHODS

We studied 458 subjects who underwent a comprehensive health check-up, which included an upper gastrointestinal endoscopy, FDG PET/CT and complete anthropometric measures. GERD symptoms were evaluated with Reflux Disease Questionnaire. Endoscopically erosive esophagitis was scored using the Los Angeles classification system. Inflammatory activity, represented by standardized uptake values (SUVmax) of FDG at pre-determined locations of esophagus, stomach and duodenum, were compared. Association between erosive esophagitis, FDG activity and anthropometric evaluation, including body mass index (BMI), waist circumference, visceral and subcutaneous adipose tissue volumes were analyzed.

RESULTS

Subjects with erosive esophagitis (n = 178, 38.9%) had significantly higher SUVmax at middle esophagus (2.69±0.74 vs. 2.41±0.57, P<.001) and esophagogastric junction (3.10±0.89 vs. 2.38±0.57, P<.001), marginally higher at upper esophageal sphincter (2.29±0.42 vs. 2.21±0.48, P = .062), but not in stomach or duodenum. The severity of erosive esophagitis correlated with SUVmax and subjects with Barrett's esophagus had the highest SUVmax at middle esophagus and esophagogastric junction. Heartburn positively correlated with higher SUVmax at middle oesophagus (r = .262, P = .003). Using multivariate regression analyses, age (P = .027), total cholesterol level (P = .003), alcohol drinking (P = .03), subcutaneous adipose tissue (P<.001), BMI (P<.001) and waist circumference (P<.001) were independently associated with higher SUVmax at respective esophageal locations.

CONCLUSIONS

Esophageal inflammation demonstrated by FDG PET/CT correlates with endoscopic findings and symptomatology of GERD. Obesity markers, both visceral and general, are independent determinants of esophageal inflammation.

[The role of psycho-autonomic status and the serotonergic system in patients with gastroesophageal reflux disease]

OBJECTIVE

Identify the differences of the autonomic nervous system (ANS), serotonin levels, cognitive, behavioral and emotsinalnoy areas in groups of patients with reflux esophagitis (RE) and non-erosive reflux disease (NERD) and assess the impact on the disease.

MATERIALS AND METHODS

The study included 71 patients rith gastroesophageal reflux disease (GERD), including 29 patients with ER, 42--NERD. Diagnosis was based on anamnesis, clinical research, fibrogastrocopy, pH-metry. Tested with a scale situational and personal anxiety Spielberg Hanina, diagnostic techniques and forms of aggression indicators A. Bass and A. Dark, the Toronto aleksitimicheskoy scale method for investigating the level of subjective control, clinical questionnaire for the identification and evaluation of neurotic states, personality questionnaire Bekhterevsky Institute, cardiointervalography, orthoklinostatik and cold test, determined the level of serotonin in the blood.

RESULTS

Compared with the group of patients suffering from ER patients with NERD determined by the displacement in the direction of internality measure locus of control personality, and patients with ER, in contrast, had lower locus of control personality, a high level of situational anxiety, irritability, anxiety type of attitude to the situation of the disease associated with impaired autonomic software ANS activity.

CONCLUSION

Patients with ER are more pronounced changes in cognitive-emotional sphere may have an impact on the course of disease and requiring psychological, medical correction.

Expression of NADPH-d in the vagal nuclei of the chronic esophagitis model in rats

AIM

To evaluate the changes in the number of NADPH diaphorase (NADPH-d) stained neurons in the vagal nuclei in a chronic esophagitis model.

MATERIALS AND METHODS

There were 3 groups of rats examined: 1) a chronic gastroesophageal reflux rat group, which was created by a partial gastric outlet obstruction; 2) a sham group; and 3) a ranitidine treated group. Serial sections ofbrainstems of all groups were cut and NADPH-d staining, which selectively stains the nitric acid synthase-containing neurons, was done.

RESULTS

Histopathological changes due to chronic reflux esophagitis was observed in the reflux group. The ranitidine treatment and sham control groups showed no changes related to esophagitis. The staining in the dorsal motor nucleus of the vagus and nucleus tractus solitarius showed statistically significant differences compared to the control group (P < 0.0001).

CONCLUSION

The increased nitric oxide expressions in the dorsal vagal nucleus and nucleus tractus solitarius are most probably due to adaptive changes to disturbed esophageal motility and mucosal damage.

An experimental study of using Chai Lai Prescription to treat in vitro rabbit models of reflux esophagitis

BACKGROUND

Chai Lai Prescription is a Chinese herbal compound which is used to sooth the liver, strengthen the spleen and harmonize the stomach for descending adverse Qi. We initiated the study to investigate its mechanism of treating in vitro rabbit reflux esophagitis models.

METHODS

Adult male Japanese white rabbits, weighing 1.8-2.2 kg, were divided into five groups of three each, which were: normal control group (Krebs buffer, pH7.4), esophagitis model group (Krebs buffer, pH5.8), esophagitis model proup+low-dose Chinese herbal medicine protection group (0.6 mg × ml(-1)× kg(-1)), esophagitis model group+moderate-dose Chinese herbal medicine protection group (6 mg × ml(-1)× kg(-1)), esophagitis model group+high-dose Chinese herbal medicine protection group (60 mg × ml(-1)×kg(-1)). The RT-PCR method was used to test the influence of Chai Lai Prescription on IL-1 and IL-6 in in vitro rabbit models of esophagitis. We treated the in vitro models with different doses of Chinese herbal medicine.

RESULTS

Esophageal mucosa were filled with various liquids. IL-6 and IL-1β mRNA expression was increased in rabbit esophageal mucosa stimulated with acid. Chinese herbal medicine significantly reduced the levels of IL-6 and IL-1β mRNA expression in the in vitro cultured rabbit esophageal mucosa. Using Chinese herbal medicine to treat in vitro models of RE, we found that the IL-6 and IL-1β mRNA expression levels went down, near to or lower than the normal control levels, compared with the group treated with acidified buffer solution.

CONCLUSIONS

Chai Lai Prescription lowered the IL-1β and IL-6 cytokine mRNA levels and protected the esophageal mucosa in the in vitro models of reflux esophagitis, suggesting that the traditional Chinese herbal compound may be able to treat reflux esophagitis by inhibiting the its inflammatory mediators.

The role of the 5-hydroxytryptamine pathway in reflux-induced esophageal mucosal injury in rats

BACKGROUND

Dysfunction of the 5-hydroxytryptamine (5-HT) signaling pathway can lead to gastrointestinal motility and secretion abnormalities and to visceral hypersensitivity. The aim of this study is to investigate the role of 5-HT in reflux-induced esophageal mucosal injury.

METHODS

Fifty 8-week-old male Sprague-Dawley (SD) rats were randomly divided into a gastroesophageal reflux (GER) model group (30 rats) and a sham surgery control group (20 rats). Four weeks after surgery, the esophageal mucosa was collected for histological evaluation, 5-HT concentrations, and 5-HT selective reuptake transporter (SERT) mRNA and 5-HT4 receptor (5-HT4R) protein expressions.

RESULTS

Twenty-seven rats in the GER model group survived, and three rats died. Histologically, in the GER model group, 20 rats had reflux esophagitis (RE group), and 7 rats had non-erosive reflux disease (NERD group). The 5-HT levels in the esophageal tissue from the RE group were significantly higher than those from the control and NERD groups. Both the RE and NERD groups showed significant increases in SERT mRNA expression of the esophageal mucosa than that of the controls, and the SERT mRNA level in the RE group was significantly higher than that in the NERD group. The 5-HT4R protein level of the esophageal mucosa in the RE group was significantly lower than that in the controls and the NERD group.

CONCLUSIONS

We conclude that a 5-HT signaling pathway disorder could be a major factor in the pathogenesis of GER and RE.

Expression of IFN-γ and IL-4 in the esophageal mucosa of patients with reflux esophagitis and Barrett's esophagus and their relationship with endoscopic and histologic grading

INTRODUCTION

This study investigated the expression of interferon-γ (IFN-γ) and interleukin-4 (IL-4) in the esophageal biopsies from patients with reflux esophagitis (RE) and Barrett's esophagus (BE) and their relationships with endoscopic grading and histologic grading.

METHODS

Ninety individuals were recruited (30 RE, 30 BE, and 30 normal control) and underwent upper gastrointestinal endoscopy with esophageal biopsy. Immunohistochemistry was used to semi-quantitatively detect the expression of IFN-γ and IL-4 in the specimens.

RESULTS

IFN-γ was overexpressed in BE and RE compared with the control (P < 0.01), whereas IL-4 was up-regulated in BE compared with RE and control (P < 0.01). A positive correlation between the level of IFN-γ and the endoscopic grading (r = 0.509, P < 0.01) and histologic grading of RE (r = 0.493, P < 0.01) was observed.

CONCLUSIONS

Th1 and Th2 immune responses play different roles in the development of RE and BE. Th1 immune response is the major pathway for RE development, whereas both Th1 and Th2 immune responses are implicated in BE pathogenesis. The expression of IFN-γ is associated with the endoscopic and histologic grading of RE.

Expression of heat shock protein 27 in the esophageal tissue of rats with reflux esophagitis

BACKGROUND

Little attention has been paid to the expression of heat shock protein 27 (HSP27) in patients with reflux esophagitis (RE), and few studies of the importance of HSP27 in esophagitis have been carried out in animal models. This study aimed to explore the expression of HSP27 in the esophageal tissue of rats with RE.

METHODS

Eighty female Wistar rats were randomly divided into experimental groups A and B and control groups C and D (n = 20 in each group). To establish RE, rats in the two experimental groups received pylorus and forestomach ligations, while rats in the control group received gastrostomy and gastric perforation repair. The rats in groups A and C were sacrificed 7 days after surgery, and the rats in groups B and D were sacrificed 14 days after surgery. In groups A and B, 10 and 8 rats were diagnosed with RE by pathological examination, respectively (they were included in groups A' and B', respectively). The histopathological diagnosis of all the lower esophageal tissues in groups C and D was normal and 20 normal specimens were randomly selected for groups C' and D' with 10 specimens in each group. Macroscopic and microscopic esophagitis scores were assessed for the specimens in groups A' and B'. Lower esophageal tissues were collected from groups A', B', C', and D', and paraffin-embedded slices were made using part of the tissues. The expression of HSP27 in the tissues was detected using the two-step streptavidin-peroxidase immunohistochemical method. Some collected tissues were frozen, and expressions of HSP27 mRNA were detected using fluorescence quantitative polymerase chain reaction (FQ-PCR).

RESULTS

Median macroscopic and microscopic esophagitis scores in groups A' (n = 10) and B' (n = 8) were 1.0 and 1.5, and 2.0 and 2.5, respectively. There were no significant differences in the macroscopic or microscopic esophagitis scores between the two groups (Z = -0.330, P = 0.741; Z = -0.142, P = 0.887, respectively). Immunohistochemical staining showed that HSP27 was expressed in all layers of the esophageal epithelia in RE and control rats. FQ-PCR showed that HSP27 mRNA levels in the lower esophageal tissue in RE group (groups A' and B') were higher than those in control group (groups C' and D') (Z = -0.249, P = 0.001). HSP27 mRNA expression in the lower esophageal tissue was significantly different in groups B' and D' (Z = -3.027, P = 0.002). And the levels of HSP27 mRNA expression in severe RE group (microscopic esophagitis score: 3) were higher than in mild RE group (microscopic esophagitis score: 1-2) and control group (Z = -3.396, P = 0.001; Z = -3.855, P < 0.001).

CONCLUSIONS

HSP27 mRNA expression in the lower esophageal tissue of rats with RE is significantly higher than in the normal controls. Although reflux is a persistent stimulating factor, increased expression of HSP27 in the lower esophageal tissue of rats with RE requires aggravated esophageal injury.

Eosinophilic oesophagitis versus reflux oesophagitis

Reflux oesophagitis (RO) is defined as the inflammation of the lower oesophagus due to damage caused by acid reflux from the stomach. Histopathologic features of acid reflux include epithelial hyperplasia, baloon cells, basal cell hyperplasia, papillary elongation, dilated intercellular spaces representing epithelial oedema, vascular congestion, and inflammatory cell infiltration comprising lymphocytes, neutrophils and eosinophils, most of which are nonspecific. Eosinophils, on the other hand, are considered to be important in the differential diagnosis of RO and EoO which is a chronic inflammatory disorder characterized by eosinophil infiltration of the oesophageal mucosa associated with a history of atopy or allergy. A cut off value of more than 15 eosinophils per high power field is suggestive of EoO with a tendency of eosinophils to concentrate in the superficial parts of squamous mucosa just below the luminal surface where they tend to form eosinophilic microabsesses. Dense fibrosis is seen in up to one-third of the patients with EoO together with an increase in the number of eosinophils in the lamina propria. In patients with intermediate levels of eosinophil counts (7-15 eos/hpf) immunohistochemistry for eosinophil secretory products could prove useful as it highlights degranulated eosinophils. In conclusion, distinguishing EoO from RO requires a thorough clinical, endoscopic and histologic evaluation of the patient which can only be achieved when close communication between pathologist and gastroenterologist is established.

Nitric oxide (NO)-releasing aspirin exhibits a potent esophagoprotection in experimental model of acute reflux esophagitis. Role of nitric oxide and proinflammatory cytokines

The purpose of this study was to develop an acute animal model of reflux esophagitis, which would be suitable to induce the esophageal damage caused by gastric acid reflux, thus mimicking the esophageal injury of human gastroesophageal reflux disease (GERD). Global research indicates that GERD is rapidly increasing among the world's population. NSAIDs are known to induce gastrointestinal damage and low doses of aspirin (ASA) have been shown to increase the incidences of GERD in humans. Gastric acid and pepsin secretion and enhanced COX-2 expression were implicated in the pathogenesis of reflux esophagitis, but the effect of selective COX-2 inhibitors against lesions induced by the reflux of gastric acid content into esophagus has not been thoroughly studied. Here, we compared the effect of aspirin (ASA) and so called "safe" nitric oxide (NO) derivative of ASA with those of non-selective and selective cyclooxygenase (COX)-1 and COX-2 in rat model of reflux esophagitis. Reflux esophagitis was induced in anesthetized rats by ligating the pylorus and limiting ridge transitional region between the forestomach and the corpus of stomach. Subsequently, the total gastric reservoir to store gastric juice was greatly diminished, resulting in the reflux of this juice into the esophagus. Rats with esophagitis received intragastric (i.g.) pretreatment either with: 1) vehicle (saline), 2) ASA or NO-ASA (100 mg/kg); 3) the non-selective COX inhibitor, indomethacin (5 mg/kg); 4) the selective COX-1 inhibitor, SC-560 (10 mg/kg), and 5) the selective COX-2 inhibitor, celecoxib (5 mg/kg). In a separate series of rats with reflux oesophagitis, the efficacy of ASA combined with a donor of NO, glyceryl trinitrate (GTN; 10 mg/kg i.g.) to prevent esophageal mucosal injury was investigated. Four hours after induction of esophagitis the gross mucosal damage was graded with a macroscopic lesion index (LI) from 0-6. The esophageal blood flow (EBF) was determined by H₂-gas clearance technique, the oesophageal mucosal and blood samples were collected for histology and analysis of the RT-PCR expression and release of proinflammatory cytokines IL-1β, TNF-α and IL-6 using specific ELISA. The exposure of the esophagus to reflux of gastric acid time-dependently increased the esophageal LI and morphologic damage, and decreased EBF with the most significant changes observed at 4 hrs after the ligation procedure. The pretreatment with native ASA in the dose that suppressed the generation of mucosal PGE₂, enhanced gross and histologic esophageal damage and produced a significant fall in EBF. NO-ASA or ASA coupled with GTN counteracted the aggravation of the damage and accompanying fall in EBF when compared with native ASA applied alone to rats with esophagitis. The proinflammatory cytokines IL-1β and TNF-α were overexpressed in rats with esophagitis and those pretreated with ASA but this effect was significantly attenuated by NO-ASA. Plasma IL-1β, TNF-α and IL-6 were negligible in the intact rats but significantly increased in those with esophagitis, with this effect being further enhanced by non-selective (indomethacin) and selective (SC-560, celecoxib) COX-1 and COX-2 inhibitors. We conclude that conventional NSAID such as aspirin augments esophagitis, while NO-ASA exerts the beneficial protective effect against reflux esophagitis via the enhancement of esophageal microcirculation due to NO release and an inhibitory effect on expression and release of pro-inflammatory cytokines.

[Panum (pantoprazole) effectiveness in the treatment of patients with GERD]

There are demonstrated results of a prospective comparative study on clinical efficacy and tolerability of Panum (INN: pantoprazole) under the sponsorship of"Unique Pharmaceutical Laboratories (India)". Were evaluated the results of a 28-day course of treatment of 30 patients with GERD, including those with severe reflux esophagitis (erosive and ulcerative), who received 40 mg of pantoprazole as monotherapy. Was found an algorithm with an intermediate control efficacy to individualizing the approach to therapy. As a result 16,7% of patients with severe reflux esophagitis required increasing the dose of pantoprazole to 80 mg/day in two divided doses, and the rest (83,3%) patients to achieve clinical and endoscopic remission of GERD was sufficient single dose of 40 mg of the drug. The results of this study indicated the efficacy and safety of the Panum drug in the treatment of GERD, including its complicated forms.

[Expression of c-myb in reflux esophagitis, Barrett esophagus and esophageal adenocarcinoma]

OBJECTIVE

To investigate the expression of c-myb in reflux esophagitis, Barrett esophagus and esophageal adenocarcinoma.

METHODS

The expression levels of c-myb in the esophageal mucosa tissue of patients with reflux esophagitis, Barrett esophagus and esophageal adenocarcinoma were detected by real-time fluorescent quantitative RT-PCR.

RESULTS

The expression levels of c-myb mRNA in Barrett esophagus and esophageal adenocarcinoma tissues was significantly higher than that in normal and reflux esophagitis esophageal tissue (P<0.05 or 0.01), and increased progressively with the development of reflux esophagitis into Barrett esophagus and esophageal adenocarcinoma.

CONCLUSIONS

The expression level of c-myb mRNA is closely related with the development of Barrett esophagus and esophageal adenocarcinoma, and may be used as a valuable index for monitoring the early onset and intervention of Barrett esophagus and esophageal adenocarcinoma.

Increased p53 expression in the malignant transformation of Barrett's esophagus is accompanied by an upward shift of the proliferative compartment

Neoplastic progression in Barrett's esophagus (BE) occurs by a multistep process associated with early molecular and morphological changes. This study evaluated cell proliferation and p53 expression and their correlation in the development and progression of esophageal adenocarcinoma. PCNA and p53 expressions were analyzed in biopsy samples by immunohistochemistry including patients with reflux esophagitis, BE, BE with concomitant esophagitis, Barrett's dysplasia, esophageal adenocarcinoma and a control group without any histological changes. Progressive increase in cell proliferation and p53 expression was found in the sequence of malignant transformation of the esophageal mucosa. While cell proliferation was significantly lower in the control group compared with all other groups, there was no increase in p53 expression of esophageal tissues that were negative for dysplasia. Dysplastic BE tissues revealed significantly higher cell proliferation and p53 expression levels compared to BE, reflux esophagitis or BE with concomitant esophagitis. Both, cell proliferation and p53 expression were significantly higher in adenocarcinoma compared to BE or Barrett's dysplasia. Interestingly, while just BE with concomitant esophagitis showed significantly higher p53 expression levels than BE, both, BE with concomitant esophagitis and reflux esophagitis revealed significantly higher cell proliferation levels compared to BE. Alterations of cell proliferation and p53 expression showed a strong correlation. Simultaneous activation of cell proliferation and p53 expression strongly suggest their association with esophageal epithelial tumor genesis and particularly, their specific role in the biology of esophageal adenocarcinoma. Quantification of these parameters in BE is thought to be useful to identify patients at higher risk for progression to adenocarcinoma.

[Role of oxidative stress in the pathogenesis of esophageal mucosal injury in children with reflux esophagitis]

OBJECTIVE

To investigate the role of oxidative stress in the pathogenesis of esophageal mucosa injury in children with reflux esophagitis (RE).

METHODS

Esophageal mucosal samples from 36 children with RE (7 months to 16 years of age) were obtained by gastroscopy. The parameters of oxidative stress, including the contents of malondialdehyde (MDA), glutathione (GSH) and nitric oxide (NO) and total superoxide dismutase (T-SOD) activity in the esophageal mucosa as well as the protein content of the esophageal mucosa, were measured. Twenty children (3 to 16 years of age) without esophageal mucosal injury by gastroscopy served as controls.

RESULTS

There was no significant difference in the protein content of the esophageal mucosa between the RE and the control groups. The content of MDA in the RE group (15.36+/- 16.67 nmol/mg) was significantly higher than that in the control group (7.51+/- 6.17 nmol/mg) (P<0.01). The activity of T-SOD in the RE group (30.43+/- 35.09 U/mg) was statistically lower than that in the control group (56.34+/- 51.73 U/mg) (P<0.05). No significant differences were observed in GSH and NO contents between the two groups.

CONCLUSIONS

The MDA content increases and the SOD content decreases in the esophageal mucosa in children with RE. This suggests that oxidative stress seems to be an important mediator in generation of esophageal mucosal injury.

Control of esophageal and intragastric pH with compounded and manufactured omeprazole in patients with reflux esophagitis: a pilot study

BACKGROUND

Proton pump inhibitors (PPI) are the drugs of choice for treatment of gastroesophageal reflux disease (GERD). Omeprazole, the first PPI commercialized, is now available in different formulations.

OBJECTIVES

To compare the efficacy of different omeprazole formulations on gastric acid secretion measured by intragastric and esophageal pH monitoring in patients with reflux esophagitis.

METHODS

Prospective, open, randomized clinical trial involving H. pylori negative patients with typical symptoms of GERD. Patients were submitted to 24-h intragastric and esophageal pH studies during use of six different formulations of compounded and manufactured omeprazole.

RESULTS

Thirty patients, 19 female, median age 55 years were studied. The intragastric pH was maintained below 4.0 for a median of 36.7% of total time in compounded group and 47.7% in manufactured group (p>0.05). There was also no statistical difference between the median percentage of time of pH below 4.0 in orthostatic and supine position in compounded and manufactured groups (30.1% and 49.6% and 28.8% and 55.2%, respectively). The esophageal pH was maintained below 4.0 for a median of 0.1% of total time in compounded group and 0.4% in manufactured group (p>0.05). In orthostatic position the median percentage of time of esophageal pH below 4.0 was 0.0% in both groups (p>0.05). In supine position, the median percentage of time of esophageal pH below 4.0 was 0.1% and 0.3% in compounded and manufactured groups, respectively (p>0.05).

CONCLUSION

The omeprazole formulations studied (compounded and manufactured) showed similar control of gastric acid secretion and esophageal acid exposure in patients with reflux esophagitis.

[Characteristics of cortical mapping in response to acid exposure in non-erosive reflux disease and erosive esophagitis using functional magnetic resonance imaging]

OBJECTIVE

To investigate the brain mechanisms for esophageal visceral hypersensitivity.

METHODS

Thirty-one non-erosive reflux disease (NERD) patients, 21 in the group of NERD with esophageal hypersensitivity (NERD-H) and 10 in the group of NERD with normal esophageal sensation (NERD-N), 13 patients with erosive esophagitis (EE), and 12 healthy volunteers, all sex- and age-matched, underwent whole brain blood oxygenation level dependent (BOLD) fictional magnetic resonance imaging (fMRI) to record the cortical fMRI response to intraesophageal perfusion of normal saline or dilute hydrochloric acid.

RESULTS

The main centers affected in the NERD-H patients included the secondary somatosensory cortex (SII), primary somatosensory cortex (S1), right prefrontal cortex (PFC), right orbitofrontal cortex (OFC), insular cortex, amygdala, striatum, motor cortex and its supplementary area, and cerebellum cortices, which form part of the matrix controlling emotional, autonomic modulatory responses to pain. The peak fMRI signal intensity and average maximum percent signal increase in the regions of interest (ROI) at above-mentioned brain areas of the NERD-H group were significantly stronger than those of the NERD-N and control groups (all P < 0.01). The peak image intensity of the anterior cingulate gyrus (ACC) of NERD-H group was 562 +/- 104, significantly lower than that of the control group (587 +/- 126, P < 0. 05), but significantly higher than that of the EE group (535 +/- 91, P < 0.05). The timeline of activation and deactivation events of particular ROI differentiate the four groups. The initial image latency and peak fMRI latency after hydrochloric acid perfusion of the NERD-H patients were 1.7 min +/- 0.9 min and peak 4. 5 min +/- 1.3 min respectively, both significantly shorter than those of the NERD-N group (4.0 min +/- 1.1 min and 6.8 min +/- 1.6 min respectively, both P < 0.01) and those of the control group (5. 4 min +/- 1.7 min and 7.2 min +/- 1.5 min respectively, both P < 0.01). The range of deactivation of SII and R-PFC of the NERD-H group were 26.5% +/- 5.4% and 20.3% +/- 3. 0% respectively, both significantly greater than those of the NERD-N group (8.2% +/- 2.2% and 16.4% +/- 3.6% respectively, both P < 0.05) and those of the EE group (11.9% +/- 4.8% and 11.7% +/- 3.1% respectively, both P < 0.01). The range of deactivation in ACC of the control group was 16.9% +/- 2.5%, significantly greater than those of the NERD-H and EE groups (11.8% +/- 2.8% and 6.4% +/- 1.0% respectively, both P < 0.05).

CONCLUSION

The function of central nervous system to integrate and manage the convergence information becomes abnormal under the status of esophageal visceral hypersensitivity.

[The indices of pro- and antioxidant state of the gastro-esophageal junction tissues in experimental gastroesophageal reflux disease]

Experimental investigation on studying of pro- and antioxidant state in esophageal tissues was performed. It was established, that accumulation of products of the proteins and lipids oxidation during inflammatory process course coincides with significant lowering of the antioxidant enzymes activity. The data obtained trusts the various diagnostic significance of diienic conjugates and malonic dialdehyde (MDA) levels. The increase of MDA concentration as well as of products of the oxidational modifications proteins, owing basic character, was revealed as a typical biochemical marker of acid-peptic injury of esophageal tissues.

Reduction of interleukin 8 gene expression in reflux esophagitis and Barrett's esophagus with antireflux surgery

HYPOTHESIS

Chronic inflammation of esophageal mucosa secondary to refluxed gastric juice increases gene expression of interleukin 8 (IL-8). Antireflux surgery can reduce this overexpression.

DESIGN

Prospective analysis of archival paraffin-embedded tissue.

SETTING

Academic tertiary medical center.

PATIENTS AND METHODS

One hundred eight patients with reflux symptoms were classified according to pH monitoring and endoscopic and histologic findings. Twenty patients did not have reflux or mucosal injury; 47 had reflux disease (16 esophagitis and 31 Barrett's esophagus), 20 had dysplasia, and 21 had adenocarcinoma. Microdissection was performed to exclude inflammatory cells and stromal tissue. After RNA isolation and reverse transcription, IL-8 messenger RNA expression was measured using quantitative real-time polymerase chain reaction. All patients with reflux disease had Nissen fundoplication with biopsies at matched levels within the esophagus preoperation and postoperation.

RESULTS

Expression of IL-8 was increased in patients with reflux compared with those without reflux. Patients with the highest IL-8 expression were those with Barrett's dysplasia and adenocarcinoma (P<.001). In patients with reflux, Nissen fundoplication led to significantly decreased IL-8 expression compared with preoperative levels in esophagitis (P = .01) and Barrett's esophagus (P = .03).

CONCLUSIONS

Interleukin 8 messenger RNA expression increases during the progression of reflux disease from normal squamous mucosa to esophageal adenocarcinoma. Elimination of reflux with Nissen fundoplication significantly reduces IL-8 expression in both squamous and Barrett's mucosa. These results demonstrate that effective antireflux surgery can modulate the gene expression of esophageal mucosa and may impact the natural history of reflux disease.

Pharmacological profile of novel acid pump antagonist 7-(4-fluorobenzyloxy)-2,3-dimethyl-1-{[(1S,2S)-2-methyl cyclopropyl]methyl}-1H-pyrrolo[2,3-d]pyridazine (CS-526)

The pharmacological profiles of the novel acid pump antagonist 7-(4-fluorobenzyloxy)-2,3-dimethyl-1-{[(1S,2S)-2-methylcyclopropyl]methyl}-1H-pyrrolo[2,3-d]pyridazine (CS-526) were investigated in terms of hog gastric H+,K+-ATPase activity, gastric acid secretion, and acute gastroesophageal lesions in comparison with other proton pump inhibitors (PPIs). CS-526 inhibited H+,K+-ATPase activity in a concentration-dependent manner, with an IC50 value of 61 nM. The inhibitory effect of CS-526 on H+,K+-ATPase activity was more potent than that of any of the other PPIs examined. The inhibitory mechanism of CS-526 on H+,K+-ATPase was a competitive antagonism to the K+ binding site of H+,K+-ATPase, and it was also a reversible inhibition. In pylorus-ligated rats, intraduodenal or oral administration of CS-526 inhibited gastric acid secretion in a dose-dependent manner, and the ID50 values were 2.8 or 0.7 mg/kg, respectively. In Heidenhain pouch dogs, intrapouch administration of CS-526 inhibited histamine-stimulated gastric acid secretion in a dose- and retention time-dependent manner. In a reflux esophagitis model, intraduodenal and oral administration of CS-526 prevented esophageal lesions with ID50 values of 5.4 and 1.9 mg/kg, respectively. Lansoprazole prevented esophagitis only by intraduodenal administration (ID50 = 2.2 mg/kg). Furthermore, CS-526 inhibited acute gastric mucosal lesions. These data demonstrate that the novel acid pump antagonist CS-526 has potent antisecretory and antiulcer effects. These findings indicate that CS-526 would have a curative effect on gastroesophageal reflux disease via its potent antisecretory and antiulcer actions.

Comparisons of the distribution of oesophageal acid exposure throughout the sleep period among the different gastro-oesophageal reflux disease groups

BACKGROUND

Nocturnal gastro-oesophageal reflux diseases (GERD) can lead to oesophageal mucosal injury and extra-oesophageal complications.

AIM

To compare distribution of oesophageal acid exposure during sleep time among patients with non-erosive reflux disease and abnormal pH test (NERD-positive), erosive oesophagitis (EO) and Barrett's oesophagus (BO).

METHODS

Patients underwent endoscopy followed by 24-h oesophageal pH testing. Oesophageal acid exposure was assessed every 2 h of the sleep period (0-2, 2-4, 4-6 and 6-8 h). Each period of 2 h was evaluated for acid reflux parameters. All groups were matched by age, time from last meal and duration of sleep time.

RESULTS

Thirty-eight patients were enrolled (NERD-positive, 16; EO, 1.4; and BO, 8). All GERD groups demonstrated higher oesophageal acid exposure in the first vs. second half of the sleep period as determined by percent time pH <4 (BO: 34.7 vs.11.6, EO: 13.5 vs. 6.9, NERD-positive: 8.8 vs. 2.5, all P < 0.01). In general, patients with BO had a significantly higher distribution of oesophageal acid exposure than those with NERD-positive and EO.

CONCLUSIONS

Oesophageal acid exposure generally declines throughout the sleep period regardless of GERD group, but BO patients demonstrated the greatest decline during the sleep period.

Alterations in manganese superoxide dismutase expression in the progression from reflux esophagitis to esophageal adenocarcinoma

BACKGROUND

Comprehensive understanding of the basic mechanisms in the progression of esophagitis, Barrett esophagus (BE), and esophageal adenocarcinoma (EAC) is urgently needed to develop a management strategy for an effective screening of BE and management of EAC. The aim of this study is to provide a detailed insight of the histology and the cellular and molecular events associated with the genesis of BE and EAC under the esophagoduodenal reflux conditions.

METHODS

Esophagoduodenal anastomosis (EDA) was performed on rats. Animals were weighed weekly and killed after 1, 2, 3, 4, 5, and 6 months. The entire esophagi were examined for macroscopic and microscopic changes and for manganese superoxide dismutase (MnSOD) expression, and TUNEL (terminal deoxynucleotidyl transferase dUTP nick-end labeling) assay was performed.

RESULTS

Morphological transformation from esophagitis (100% of animals) to BE (66% of animals) to EAC was observed after 3 months. There was marked loss of MnSOD expression in animals with esophagitis and BE at 1 and 2 months, with an increase in expression during the transformation to dysplasia and EAC. Increased proliferation and apoptosis was observed and reached a peak at months 1 and 2. Greatly increased levels of 8-hydroxy-deoxyguanosine was found during the progression to EAC.

CONCLUSIONS

The morphological transformation of the esophageal mucosa is an adaptive process, and it is an important foundation for the transdifferentiation of BE and cancer. The significant loss of MnSOD expression to achieve BE and then the adaptive increase in expression to achieve dysplasia and EAC during this transformation may represent a predictive marker in identifying patients who will progress from BE to EAC.

Calcitonin gene-related peptide relates to cough sensitivity in children with chronic cough

Airway neuropeptides, in particular calcitonin gene-related peptide (CGRP), are likely to be important in the pathogenesis of chronic cough. The present authors evaluated the following: 1) the relationship between cough sensitivity and bronchoalveolar lavage (BAL) neuropeptides; and 2) the effect of reflux oesophagitis (RO) on cough, cough sensitivity and BAL neuropeptides in children not selected for cough. It was hypothesised that CGRP would be increased in children with chronic cough and would relate to cough sensitivity. Capsaicin cough sensitivity was performed in children undergoing gastro-duodenal endoscopy. CGRP, substance P and neurokinin A were measured in BAL obtained nonbronchoscopically. Children were defined as "coughers" if chronic cough was present. Coughers (n = 21) had significantly reduced cough sensitivity but were just as likely as noncoughers (n = 19) to have RO. The median CGRP was significantly higher in coughers with oesophagitis than in noncoughers with oesophagitis. CGRP significantly negatively correlated to cough sensitivity in coughers but not in noncoughers. Elevated calcitonin gene-related peptide, but not substance P or neurokinin A, is only associated with chronic cough in children when oesophagitis coexists. Calcitonin gene-related peptide in bronchoalveolar lavage relates to cough sensitivity and is likely to be important in the pathophysiology of chronic cough.

Expression of the bile acid receptor FXR in Barrett's esophagus and enhancement of apoptosis by guggulsterone in vitro

BACKGROUND

Barrett's esophagus, a risk factor for esophageal adenocarcinoma, is associated with reflux disease. The aim of this study was to assess the expression of bile acid receptors in the esophagus (normal, esophagitis, Barrett's esophagus and adenocarcinoma) and to investigate their possible function.

RESULTS

the expression of the bile acid receptors FXR and VDR in esophageal biopsies from patients with a normal mucosa, esophagitis, Barrett's esophagus or adenocarcinoma (n = 6 per group) and in cell lines derived from Barrett's esophagus and esophageal adenocarcinoma, was assessed by real time Q-PCR and immunohistochemistry. The effect of guggulsterone, an antagonist of bile acid receptors, on apoptosis of Barrett's esophagus-derived cells was assessed morphologically, by flow cytometry and by measuring caspase 3 activity. The expression of FXR was increased in esophagitis, Barrett's esophagus and adenocarcinoma compared to normal mucosa by a mean of 44, 84 and 16, respectively. Immunohistochemistry showed a weak expression in normal esophagus, a strong focal reactivity in Barrett's esophagus, and was negative in adenocarcinoma. VDR expression did not significantly differ between groups. In cell cultures, the expression of FXR was high in Barrett's esophagus-derived cells and almost undetectable in adenocarcinoma-derived cells, whereas VDR expression in these cell lines was not significantly different. In vitro treatment with guggulsterone was associated with a significant increase in the percentage of apoptotic cells and of the caspase 3 activity.

CONCLUSION

the bile acid receptor FXR is significantly overexpressed in Barrett's esophagus compared to normal mucosa, esophagitis and esophageal adenocarcinoma. The induction of apoptosis by guggulsterone in a Barrett's esophagus-derived cell line suggests that FXR may contribute to the regulation of apoptosis.

Review article: human pepsins - their multiplicity, function and role in reflux disease

Human gastric juice contains a multiplicity of proteinases. These are classified as aspartic proteinases because of enzymic activity dependent on two oppositely placed aspartic acids in the active site region. At least seven zones of activity can be visualized by agar gel electrophoresis and a similar number of separate proteins resolved by high performance ion exchange chromatography. The major enzyme secreted (up to 70% of the total) pepsin 3b is sensitive to the selective inhibitor pepstatin whereas gastricsin or pepsin 5 (20% of the total) is not. Minor enzymes including pepsin 1, which has an associated proteincarbohydrate complex attached is variable and can be < 5% in normal and up to 20% of the total as in peptic ulcer patients. The activity of these enzymes depends on the substrate and pH with significant digestion occurring up to pH 4.5. It has also been shown that these enzymes can bind to substrates like collagen up to pH 5.5. In gastric secretion studies of patients with reflux oesophagitis the amount of pepsin and the profile of the enzymes in basal secretions, and that after pentagastrin stimulation, was found to be not different from healthy non-refluxers. Thus the problem with reflux is that gastric juice appears in the oesophagus, an area without any natural protection from proteolytic damage. The ability to reduce gastric secretion is therefore important in effective treatment. However, being able also to inhibit enzymic activity or protect substrates from damage using alginates offers considerable scope for future therapies.

The effect of luteolin-7-O-β-d-glucuronopyranoside on gastritis and esophagitis in rats

This study evaluated the inhibitory action of luteolin-7-O-beta-D-glucuronopyranoside, luteolin which was isolated from Salix gilgiana leaves, and omeprazole on reflux esophagitis and gastritis in rats. Reflux esophagitis and gastritis were induced surgically and by the administration of indomethacin, respectively. The intraduodenal administration of luteolin-7-O-beta-D-glucuronopyranoside decreased the ulcer index, injury area, gastric volume and acid output, and increased the gastric pH compared with luteolin. Luteolin-7-O-beta-D-glucuronopyranoside significantly decreased the size of the gastric lesions that had been induced by exposing the gastric mucosa to indomethacin. The malondialdehyde content, which is the end product of lipid peroxidation, was increased significantly after inducing of reflux esophagitis. The malondialdehyde content was decreased by Luteolin-7-O-beta-D-glucuronopyranoside but not luteolin or omeprazole. Luteolin-7-O-beta-D-glucuronopyranoside has a more potent antioxidative effect than luteolin. Luteolin-7-O-beta-D-glucuronopyranoside is a promising drug for the treatment of reflux esophagitis and gastritis.

High incidence of fermentation in the digestive tract in patients with reflux oesophagitis

OBJECTIVES

Because bacteria represent the sole source of gut hydrogen (H2) and methane (CH4), fasting breath H2 and CH4 gases have been used as markers of colonic fermentation. The presence of carbohydrates in the colonic lumen inhibits gastric and pancreatic secretions, and also influences lower oesophageal sphincter function in gastro-oesophageal reflux disease.

MATERIALS AND METHODS

Studies were performed in 793 consecutive patients undergoing oesophagogastroscopy (270 men and 523 women, aged 19-85 years). A fasting breath sample (20 ml) was collected before endoscopy. At endoscopy, we intubated the stomach without inflation by air, and 20 ml of intragastric gas was collected through the biopsy channel. Next, the tip of the endoscope was inserted into the second portion of the duodenum without inflation by air, and 20 ml of intraduodenal gas was collected. H2 and CH4 concentrations of each sample were measured by gas chromatography.

RESULTS

Reflux oesophagitis was found in 147 of the 793 patients. The mean values of the H2 and/or CH4 levels of samples taken from the stomach, duodenum and exhaled air were higher in patients with reflux oesophagitis than those without reflux oesophagitis. High H2 and/or CH4 levels were more frequently found in patients with reflux oesophagitis.

CONCLUSIONS

We concluded that the presence of fermentation in the digestive tract was considered to be a risk factor for developing reflux oesophagitis.

mRNA expression of inducible nitric oxide synthase, endothelial nitric oxide synthase and vascular endothelial growth factor in esophageal mucosa biopsy specimens from patients with reflux esophagitis

BACKGROUND/AIMS

Nitric oxide (NO) production is elevated in the intestine and may contribute to intestinal injury during inflammation. However, how the expression of inducible NO synthase (iNOS) mRNA and endothelial NO synthase (eNOS) mRNA in the esophageal mucosa contribute to mucosal damage caused by reflux esophagitis remains unknown. Since vascular endothelial growth factor (VEGF) exerts its action on microcirculation, contributing to angiogenesis and inflammation, we examined the role of VEGF together with iNOS and eNOS on development of reflux esophagitis.

METHODOLOGY

The mRNA expression levels of iNOS, eNOS and VEGF were measured in biopsy specimens from 25 patients with reflux esophagitis, using TaqMan PCR and reverse transcription PCR.

RESULTS

The expression of iNOS mRNA in the esophageal mucosa increased parallel to the severity of the esophagitis. There were no significant differences between both eNOS and VEGF mRNA expression levels and the severity of the esophagitis. The existence of gastric mucosal atrophy, hiatus hernia, therapy and Helicobacter pylori infection did not affect the levels of mRNA expression.

CONCLUSIONS

The accumulation of NO, produced by iNOS, was considered to be related to the exacerbation of reflux esophagitis. Therapeutic intervention that reduces NO production may thus be of use in preventing development of esophageal mucosal injury in patients with reflux esophagitis.

Roles of epidermal growth factor and Na+/H+ exchanger-1 in esophageal epithelial defense against acid-induced injury

Epidermal growth factor (EGF) is predominantly secreted by salivary glands and activates Na(+)/H(+) exchanger-1 (NHE-1), which regulates intracellular pH (pH(i)). We investigated the roles of EGF and NHE-1 in esophageal epithelial defense against acid using human esophageal epithelial cell lines and a rat chronic esophagitis model. Esophageal epithelial cells were incubated with acidified medium in the absence or presence of EGF. Cell viability and changes in pH(i) were measured. Chronic acid reflux esophagitis was induced in rats with and without sialoadenectomy. Esophageal lesion index, epithelial proliferation, and expression of EGF receptors and NHE-1 were examined. EGF protected esophageal epithelial cells against acid in a dose-dependent manner, and the cytoprotective effect of EGF was completely blocked by treatment with NHE-1 inhibitors. Tyrosine kinase, calmodulin, and PKC inhibitors significantly inhibited cytoprotection by EGF, whereas MEK, phosphatidylinositol 3-kinase, and PKA inhibitors had no effect. EGF significantly increased pH(i) recovery after NH(4)Cl pulse acidification, and this increase in pH(i) recovery was significantly blocked by inhibitors of calmodulin and PKC. Sialoadenectomy led to an increase in the severity of chronic esophagitis but affected neither epithelial proliferation nor expression of EGF receptors. Expression of NHE-1 mRNA was increased in esophagitis and upregulated in rats with sialoadenectomy. The increasing severity of esophagitis in rats with sialoadenectomy was prevented by exogenous administration of EGF. In conclusion, EGF protects esophageal epithelial cells against acid through NHE activation via Ca(2+)/calmodulin and the PKC pathway. Deficiency in endogenous EGF is associated with increased severity of esophagitis. EGF and NHE-1 play crucial roles in esophageal epithelial defense against acid.

The extent of oesophageal acid exposure overlap among the different gastro-oesophageal reflux disease groups

BACKGROUND

Studies have demonstrated that patients with Barrett's oesophagus have the highest oesophageal acid exposure profile, followed by erosive oesophagitis and non-erosive reflux disease patients, but the exact extent of overlap remains unknown.

AIM

To determine the extent of overlap in oesophageal acid exposure among the different gastro-oesophageal reflux disease groups.

METHODS

A total of 121 patients with gastro-oesophageal reflux disease underwent an upper endoscopy and were classified as having Barrett's oesophagus, erosive oesophagitis and non-erosive reflux disease-all (non-erosive reflux disease-positive and functional heartburn). Subsequently, patients underwent pH testing and overlap in oesophageal acid exposure among the different gastro-oesophageal reflux disease groups was determined.

RESULTS

Of those enrolled, 24 had Barrett's oesophagus, 30 erosive oesophagitis and 28 were non-erosive reflux disease-positive. Mean oesophageal acid exposure time was 224.8 +/- 35, 134.3 +/- 21.9 and 141.3 +/- 19.8 min for Barrett's oesophagus, erosive oesophagitis and non-erosive reflux disease-positive respectively. Per cent overlap for total, upright and supine time between non-erosive reflux disease-positive and erosive oesophagitis was 47.4%, 64.7% and 81.8%, between Barrett's oesophagus and erosive oesophagitis was 47.8%, 40.7% and 24%, and between Barrett's oesophagus and non-erosive reflux disease-positive was 31.6%, 37.5% and 20.8% respectively.

CONCLUSIONS

Our study demonstrated a high oesophageal acid exposure overlap between patients with non-erosive reflux disease-positive and erosive oesophagitis, Barrett's oesophagus and erosive oesophagitis, as well as Barrett's oesophagus and non-erosive reflux disease-positive patients.

Hydrogen peroxide reduces lower esophageal sphincter tone in human esophagitis

BACKGROUND & AIMS

We have previously used the normal lower esophageal sphincter (N-LES) of human organ donors to examine the physiologic signal transduction of lower esophageal sphincter (LES) circular muscle. Now, for the first time, we have obtained a human LES specimen with esophagitis (E-LES) and characterized its pathophysiologic mechanical and inflammatory profiles.

METHODS

E-LES was examined histologically, and its in vitro circular muscle contraction and production of inflammatory mediators were compared with those of N-LES.

RESULTS

E-LES exhibited scattered erosions and displayed inflammatory cells in the epithelial layer, basal zone hyperplasia, and elongation of lamina propria papillae, characteristic of chronic reflux esophagitis. E-LES muscle strips developed lower in vitro tone (0.78 g) than N-LES (3.3 +/- 0.2 g). E-LES tone was essentially restored to normal by the H2O2 scavenger catalase, suggesting that H2O2 was responsible for reduction of tone. NOX5 cDNA was higher and H2O2 levels were 4 times higher in E-LES circular muscle (0.85 nmol/mg protein) than in N-LES (0.19 +/- 0.05 nmol/mg protein). When N-LES smooth muscle was incubated in H2O2 (70 micromol/L, 2 hours), platelet activating factor (PAF), prostaglandin E2 (PGE2), and F2-isoprostane increased 2.5, 5.2, and 36 times, respectively. In E-LES, levels of PAF, PGE2, and F2-isoprostane were 4, 6, and 40 times, respectively, higher than in N-LES. PAF, PGE2, and F2 isoprostane produced dose-dependent reductions in tone of N-LES muscle strips.

CONCLUSIONS

We conclude that an excessive production of H2O2 triggers an increased production of PAF, PGE2, and F2-isoprostane, which are responsible for reducing LES tone in human esophagitis.

Altered localization and expression of tight-junction proteins in a rat model with chronic acid reflux esophagitis

BACKGROUND

The esophageal tight junction is responsible for the paracellular sealing of the epithelium. Alteration of the expression of tight-junction proteins plays crucial roles in the pathogenesis of some human diseases. The aim of this study was to investigate the distribution and expression pattern of tight-junction proteins in the esophageal mucosa of control rats and rats with reflux esophagitis.

METHODS

Chronic acid reflux esophagitis was experimentally induced by operation in rats. The animals were killed on days 7 and 14 after the operation. The thickness of the mucosa and the 5-bromo-2-deoxyuridine (BrdU) labeling index were assessed. The expression pattern of the tight-junction proteins claudin 1-4 and occludin in the esophageal mucosa was investigated by immunofluorescence staining and Western blotting in the controls and esophagitis rats.

RESULTS

In the esophagitis model, the thickness and BrdU labeling index increased with time. In control rats, claudin-1, -3, and -4 were localized on the cellular membranes of esophageal epithelial cells, mainly in the spinous and granular layers, while claudin-2 was not detected in any layer. Occludin was seen on the cellular membranes in all esophageal mucosal layers. In the esophagitis rats, the expression of claudin-1 was increased both in the plasma membrane and in the cytoplasm around the erosion in the spinous and granular layers. The expression of claudin-4 and occludin shifted to the cytoplasm from the plasma membrane in the spinous and granular layers. In contrast, the expression of claudin-3 was decreased in the spinous and granular layers.

CONCLUSIONS

The localization and the expression patterns of tight-junction proteins were different in the controls and the rat esophagitis model. The expression of claudin-3 in the esophageal mucosa was decreased, while that of claudin-1 was increased. It is postulated that these alterations in tight-junction proteins most likely increase the permeability of the esophageal the epithelium, thereby impairing the defense mechanism of this epithelium.

Cytokine-induced neutrophil accumulation in the pathogenesis of acute reflux esophagitis in rats

Although recent reports indicate an increasing incidence of patients with reflux esophagitis, its pathomechanism remains unclear. Cytokines and neutrophils, the latter of which produce reactive oxygen species (ROS), have been implicated in the formation of gastrointestinal diseases. This study investigated the roles of neutrophils, ROS, and cytokines in the pathogenesis of experimental reflux esophagitis. Esophagitis was induced in male Wistar rats by ligation at both the limiting ridge of the stomach and lower portion of the duodenum. The esophagus was then removed, and the lesion index, wet weight, thiobarbituric acid-reactive substances (an index of lipid peroxidation), myeloperoxidase activity (an index of neutrophil accumulation), tumor necrosis factor-alpha (TNF-alpha), and cytokine-induced neutrophil chemoattractant (CINC)-1 in the esophageal mucosa were estimated, and a histological study (hematoxylin-and-eosin staining) was performed. The mRNA expression of TNF-alpha and CINC-1 was analyzed. Anti-neutrophil serum (ANS) was injected intraperitoneally prior to the induction of esophagitis, and inflammatory markers were estimated as described above. The values of all markers increased, and the histological study revealed neutrophil infiltration and edema in mucosa and submucosa at both 12 and 18 h after induction. However, the mRNA expression of both cytokines was observed earlier at 3 and 6 h after induction. ANS inhibited the increases in all inflammatory markers. These results indicate that ROS and lipid peroxidation mainly derived from neutrophils, which are stimulated and mobilized by TNF-alpha and CINC-1, are implicated in the pathogenesis of esophageal inflammation induced by the reflux of gastroduodenal contents.

Effect of CYP2C19 polymorphism on the safety and efficacy of omeprazole in Japanese patients with recurrent reflux oesophagitis

BACKGROUND

The polymorphic enzyme cytochrome P450 2C19 affects omeprazole metabolism. This influence on metabolism might affect serum gastrin levels, and safety, during long-term treatment of reflux oesophagitis.

AIM

To examine the relationship between cytochrome P450 2C19 genotype and the safety profile of long-term omeprazole treatment.

METHODS

A total of 119 Japanese patients with recurrent reflux oesophagitis underwent cytochrome P450 2C19 genotyping prior to receiving daily omeprazole 10 mg or 20 mg for 6-12 months, during which adverse event frequency, serum gastrin levels and endoscopic findings were monitored.

RESULTS

The incidences of adverse events, serious adverse events and adverse events leading to withdrawal did not differ between homozygous extensive metabolizer (n = 46), heterozygous extensive metabolizer (n = 53) or poor metabolizer (n = 20) groups. In all genotype groups, serum gastrin increased during the first 3 months of dosing but stabilized thereafter. No significant differences were seen either in the rate of reflux oesophagitis healing or symptom improvement among genotype groups.

CONCLUSIONS

Long-term treatment with omeprazole was well-tolerated in Japanese patients, irrespective of their cytochrome P450 2C19 metabolic genotype, indicating that dose adjustment depending on metabolic genotype is not required during treatment with omeprazole.

Expression of CXC receptor 1 and 2 in esophageal mucosa of patients with reflux esophagitis

AIM: Interleukin 8 (IL-8) mediates neutrophil trafficking via its receptors. Recent studies have shown that IL-8 is likely involved in the development and progression of erosive reflux esophagitis (RE), yet little is known about the two distinct receptors, CXC receptor (CXCR)-1 and -2. The purpose of this study was to determine CXCR-1 and -2 messenger RNA expression levels in RE.

METHODS: We studied 26 patients with RE and 15 asymptomatic controls. Paired biopsy samples were taken from the esophagus 3 cm above the gastroesophageal junction; one biopsy was snap frozen for measurement of CXCR-1 and -2 mRNA levels by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR), and another was formalin-fixed for histopathological evaluation. We also examined the association of the expression levels of CXCR-1 and -2 mRNA with histopathological hallmarks of RE.

RESULTS: The relative CXCR-1 and -2 mRNA expression levels were rather decreased in esophageal mucosa of patients with RE, compared to those in normal esophagus of controls. There were no significant difference in the relative mRNA expression levels of CXCR-1 and -2 among endoscopic grades of RE based on the Los Angeles classification. Each histopathological hallmark of GERD was not associated with the expression levels of CXCR-1 and -2 mRNA.

CONCLUSION: Apart from overexpression of IL-8, the relative expression levels of CXCR-1 and -2 mRNA were rather lower than expected in the affected esophageal mucosa of patients with RE.

Increased expression of transforming growth factor-alpha and epidermal growth factor receptors in rat chronic reflux esophagitis

BACKGROUND AND AIM

Transforming growth factor-alpha (TGF-alpha), which binds to epidermal growth factor receptors (EGF-R), stimulates esophageal epithelial cell proliferation, enabling rapid repair after mucosal injury. The aim of the present study was to examine epithelial proliferation and dynamics of TGF-alpha and EGF-R gene and protein expression in rat chronic acid reflux esophagitis.

METHODS

Gastric acid reflux esophagitis was induced in Wistar rats by ligating the transitional region between the forestomach and the glandular portion, and by covering the duodenum near the pyloric ring with a small piece of an 18Fr Nélaton catheter. Epithelial cell proliferation was assessed by bromodeoxyuridine (BrdU) uptake. Expression of TGF-alpha and EGF-R mRNA and protein was assessed by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry.

RESULTS

Esophageal lesions were observed in the lower and middle esophagus. Histologically, a significant increase in mucosal thickening with elongation of lamina propria papillae and basal cell hyperplasia was observed. The BrdU labeling index was significantly increased from 2.7 +/- 1.0 in normal mucosa and 2.8 +/- 1.2 in background mucosa adjacent to the esophageal lesion, to 60.3 +/- 32.7 in the lesions of chronic esophagitis. Expression of TGF-alpha and EGF-R mRNA in the esophageal lesion significantly increased compared to those in the control and background tissue, whereas treatment with rabeprazole significantly inhibited increases in TGF-alpha and EGF-R mRNA expression. According to immunohistochemical study, TGF-alpha and EGF-R revealed strong expression in esophageal lesions compared with control and background mucosa. The superficial layer of the esophagus was strongly positive for TGF-alpha and most cells in regions of basal hyperplasia had a positive reaction for EGF-R in the esophagitis lesion.

CONCLUSION

Epithelial proliferation and expression of TGF-alpha and EGF-R were significantly increased in rat chronic reflux esophagitis. Activation of TGF-alpha and EGF-R genes in response to acid reflux may facilitate rapid mucosal healing by stimulating epithelial proliferation. These results suggest that TGF-alpha and EGF-R play crucial roles in rat chronic reflux esophagitis.

The effect of eight weeks of rabeprazole therapy on nitric oxide plasma level and esophageal pH and motility and motility nitric oxide plasma level in patients with erosive esophagitis

BACKGROUND

Esophageal clearance, an important pathogenetic factor in gastroesophageal reflux disease, depends mainly on motility. Motility disturbances can be secondary to gastric output reflux. Nitric oxide influences esophageal motility. The aim of this study was to determine the effect of eight weeks of gastric acid secretion suppression with rabeprazole (20 mg/day) on esophageal motility.

MATERIAL/METHODS

20 patients with erosive esophagitis were studied. At study start and two weeks after the end of therapy, we recorded the results of interview, endoscopy, gastric and esophageal mucosa biopsy, 24-h esophageal pH-metry and manometry, and NO metabolites plasma concentration, determined spectrophotometrically (OXIS).

RESULTS

All patients reported improvement and remained free of symptoms two weeks later. In 60% of cases, improvement of esophageal mucosa appearance was observed in endoscopic and histological examination. In follow-up we found a significantly smaller number of acid gastrooesophageal refluxes (p<0.05), reduced DeMeester score for pH range >7 (p<0.05), and greater % of time within the esophageal pH range 6-7 (p<0.05). Other esophageal pH-metry and 24-h manometry parameters did not change significantly. NO metabolites plasma concentration increased significantly (p=0.039).

CONCLUSIONS

Clinical improvement after eight weeks of therapy with rabeprazole was connected with endoscopic changes only in 60% of our patients. Rabeprazole therapy did not influence esophageal motility, despite increased plasma levels of NO metabolites. Patients with erosive esophagitis need maintenance therapy, since as soon as two weeks after the end of treatment the % of monitoring time with esophageal pH<4 was similar to study start.