Development of Pancreatic Acinar Cell Metaplasia During Gastric Repair in a Rat Duodenal Contents Reflux Model.

BACKGROUND: We previously reported the development of pancreatic acinar cell metaplasia (PACM) in the glandular stomach of a duodenal contents reflux model (reflux model). AIMS: We aimed to investigate the characteristics and histogenesis of PACM using a reflux model. METHODS: A reflux model was created using 8-week-old male Wistar rats, which were killed up to 30 weeks postoperatively. Histological examination was performed to analyze the glandular stomach-jejunal anastomosis. Furthermore, electron microscopic images of PACM samples were compared with pancreatic and gastric glands removed from rats that had not undergone surgery. Immunostaining for α-amylase, HIK1083, TFF2, and Ki-67 was performed, and double fluorescent staining was carried out using antibodies against α-amylase and HIK1083, or α-amylase and TFF2. RESULTS: In all reflux model rats, PACM was observed proximal to the glandular stomach-jejunal anastomosis, surrounded by pseudopyloric metaplasia. The number of chief cells was decreased in the deep part of the gland, where PACM occurred. Electron microscopy showed that PACM cells had greater numbers of rough endoplasmic reticulum tubules than chief cells, and exhibited pancreatic acinar cell morphology. Upon immunochemical staining, the regenerative foveolar epithelium and part of the pseudopyloric glands stained strongly positive for TFF2, whereas PACM cells were only weakly positive. Double fluorescent staining identified early lesions of PACM in the neck, which were double positive for α-amylase and TFF2, but negative for HIK1083. CONCLUSIONS: PACM could be induced by duodenal contents reflux. PACM originates from stem cells located in the neck of oxyntic glands during gastric mucosal regeneration.

Hyperinsulinemia Promotes Esophageal Cancer Development in a Surgically-Induced Duodeno-Esophageal Reflux Murine Model.

Hyperinsulinemia could have a role in the growing incidence of esophageal adenocarcinoma (EAC) and its pre-cancerous lesion, Barrett's Esophagus, a possible consequence of Gastro-Esophageal Reflux Disease. Obesity is known to mediate esophageal carcinogenesis through different mechanisms including insulin-resistance leading to hyperinsulinemia, which may mediate cancer progression via the insulin/insulin-like growth factor axis. We used the hyperinsulinemic non-obese FVB/N (Friend leukemia virus B strain) MKR (muscle (M)-IGF1R-lysine (K)-arginine (R) mouse model to evaluate the exclusive role of hyperinsulinemia in the pathogenesis of EAC related to duodeno-esophageal reflux. FVB/N wild-type (WT) and MKR mice underwent jejunum-esophageal anastomosis side-to end with the exclusion of the stomach. Thirty weeks after surgery, the esophagus was processed for histological, immunological and insulin/Insulin-like growth factor 1 (IGF1) signal transduction analyses. Most of the WT mice (63.1%) developed dysplasia, whereas most of the MKR mice (74.3%) developed squamous cell and adenosquamous carcinomas, both expressing Human Epidermal growth factor receptor 2 (HER2). Hyperinsulinemia significantly increased esophageal cancer incidence in the presence of duodenal-reflux. Insulin receptor (IR) and IGF1 receptor (IGF1R) were overexpressed in the hyperinsulinemic condition. IGF1R, through ERK1/2 mitogenic pattern activation, seems to be involved in cancer onset. Hyperinsulinemia-induced IGF1R and HER2 up-regulation could also increase the possibility of forming of IGF1R/HER2 heterodimers to support cell growth/proliferation/progression in esophageal carcinogenesis.

Gastroesophageal Mucosal Injury after Cholecystectomy: An Indication for Surveillance?

BACKGROUND: Cholecystectomy alters bile release dynamics from pulsatile meal-stimulated to continuous, and results in retrograde duodeno-gastric bile reflux (DGR). Bile is implicated in mucosal injury after gastric surgery, but whether cholecystectomy causes esophagogastric mucosal inflammation, therefore increasing the risk of metaplasia, is unclear. STUDY DESIGN: This study examined whether cholecystectomy-induced DGR promotes chronic inflammatory mucosal changes of the stomach and/or the esophagogastric junction (EGJ). Four groups of patients were studied and compared with controls. A group of patients was studied before and 1 year after cholecystectomy; 2 further groups were studied long-term post-cholecystectomy (LTPC) at 5 to 10 years and 10 to 20 years. All underwent abdominal ultrasound and upper gastrointestinal endoscopy with gastric antral and EGJ biopsies, noting the presence of gastric bile pooling. Biopsy specimens were stained for Ki67 and p53 overexpression, and the bile reflux index (BRI) was calculated. RESULTS: At endoscopy, bile pooling was observed in 9 of 26 (34.6%) controls, in 8 of 25 (32%) patients pre-cholecystectomy, in 15 of 25 (60%) 1 year post-cholecystectomy patients (p = 0.047), and 23 of 29 (79.3%) LTPC patients (p = 0.001). Bile reflux index positivity at the EGJ increased from 19% of controls through 41% of LTPC patients (p = 0.032). Ki67 was overexpressed at the EGJ in 19% of controls, but in 62% of LTPC patients (p = 0.044); p53 was overexpressed at the EGJ in 19% of controls compared with 66% of LTPC patients (p = 0.001). CONCLUSIONS: Duodeno-gastric bile reflux was more common in patients with gallstones than in controls, and its incidence doubled after cholecystectomy. This was associated with inflammatory changes in the gastric antrum and the EGJ, evident in most LTPC patients. Ki67 and p53 overexpression at the EGJ suggests cellular damage attributable to chronic bile exposure post-cholecystectomy, increasing the likelihood of dysplasia. Further studies are required to determine whether DGR-mediated esophageal mucosal injury is reversible or avoidable, and whether surveillance endoscopy is indicated after cholecystectomy.

[Gastroesophageal reflux disease in patients receiving chemotherapy: clinical, endoscopic, morphological and immunohistochemical features].

THE PURPOSE OF THE STUDY: Determine the pathogenetic significance of express molecules PCNA, Bcl-2, NF-Kb and tachykinins (substance P, neurokinin A) in patients with gastroesophageal reflux disease (GERD), receiving polychemotherapy (PCT). MATERIALS AND METHODS: In total 60 patients were examined with GERD time-divided into 2 equal groups on the receiving PCT Leukemia over standard dose for at least one year. The first group consisted of 30 subjects with non-erosive GERD (NEGERD) endoscopically positive form receiving PCT. The second group consisted of 30 subjects with erosive form of GERD (EFGERD) receiving PCT. Patients underwent endoscopy, morphological and immunohistochemical examination of the esophageal mucosa to the definition expression of molecules PCNA, Bcl-2, neurokinin A, substance P and factor Nf-Kb. In patients with refractory form of GERD to proton pump inhibitors therapy (PPIs), additionally imposed ursodeoxycholic acid. THE RESULTS: Patients with NEGERD receiving PCT in 33.3% of cases formed refractory to PPIs form of the disease, when EFGERD refractoriness occurs in 46.7% of patients, which is associated with slowing the proliferation of epithelial cells of the esophagus due to decreased expression of PCNA. Reduced expression of neurokinin A in patients receiving PCT is associated with less activity and intensity of inflammation of esophageal mucosa. Against the background of a high degree of PCT expression of Bcl-2 and factor Nf-Kb, which may explain the frequent detection of atrophic and meta- plastic changes in the esophageal mucosa. Appointment of ursodeoxycholic acid in the complex therapy of GERD can overcome resistance to PPIs and improve the performance of cell renewal. CONCLUSION: Due to the frequent development of GERD refractory to PPIs in patients suffering from diseases requiring the appointment of long-term courses of PCT requires the appointment of cytoprotective therapy, as that can be used ursodeoxycholic acid.

Detection of Apical Inflammatory Root Resorption Associated with Periapical Lesion Using Different Methods

The aim of this study was to detect apical inflammatory root resorption (AIRR) associated with periapical lesion using cone beam computed tomography (CBCT) and scanning electronic microscopy (SEM). This clinical study evaluated AIRR in 88 root apexes, from 52 permanent teeth of 14 patients, extracted for different reasons. The patients were submitted to a clinical interview, review of dental/medical histories and clinical/imaging examinations for treatment planning. All selected teeth showed unrestorable condition because of the extensive coronal breakdown due to carious lesions, and root canal infection associated with periapical lesions. CBCT images were obtained from the patients with the aim of diagnosing the periapical diseases which showed complex or doubtful conditions. Two examiners assessed the presence or absence of AIRR. Apices were also analyzed under SEM. Chi-square test was used to compare the imaging methods for detection of AIRR. The level of statistical significance was set at 5%. AIRR associated with root canal infection and apical periodontitis was found in 61.4% of the cases studied by using SEM, and at least half of the cases by CBCT. The microscopic analysis remains as a reference standard against the imaging method to identify AIRR.

O objetivo deste estudo foi detectar reabsorção radicular inflamatória apical (RRIA) associada à lesão periapical utilizando tomografia computadorizada de feixe cônico (TCFC) e microscopia eletrônica de varredura (MEV). Este estudo clínico avaliou RRIA em 88 ápices radiculares de 52 dentes permanentes de 14 pacientes, extraídos por diferentes motivos. Os pacientes foram submetidos a uma entrevista clínica, revisão da história médica/dental, exames clínicos e de imagem para o plano de tratamento. Todos os dentes selecionados apresentaram condição não restaurável devido à extensa perda de estrutura dental associada a lesões cariosas, e infecção do canal radicular associada a lesões periapicais. TCFC foram obtidas dos pacientes com o objetivo de diagnosticar as alterações periapicais que se mostraram complexas ou duvidosas. Dois examinadores avaliaram a presença ou ausência de RRIA. Os ápices foram também analisados por MEV. O teste do qui-quadrado foi usado para comparar os métodos de detecção de RRIA. O nível de significância foi estabelecido em 5%. RRIA associada à infecção do canal radicular e periodontite apical foi encontrada em 61,4% dos casos estudados usando MEV, e pelo menos metade dos casos utilizando TCFC. A análise microscópica continua a ser o padrão frente a métodos de imagens para a identificação de RRIA.

Comparative evaluation of intragastric bile acids and hepatobiliary scintigraphy in the diagnosis of duodenogastric reflux.

AIM: To assess the diagnostic value of a combination of intragastric bile acids and hepatobiliary scintigraphy in the detection of duodenogastric reflux (DGR). METHODS: The study contained 99 patients with DGR and 70 healthy volunteers who made up the control group. The diagnosis was based on the combination of several objective arguments: a long history of gastric symptoms (i.e., nausea, epigastric pain, and/or bilious vomiting) poorly responsive to medical treatment, gastroesophageal reflux symptoms unresponsive to proton-pump inhibitors, gastritis on upper gastrointestinal (GI) endoscopy and/or at histology, presence of a bilious gastric lake at > 1 upper GI endoscopy, pathologic 24-h intragastric bile monitoring with the Bilitec device. Gastric juice was aspirated in the GI endoscopy and total bile acid (TBA), total bilirubin (TBIL) and direct bilirubin (DBIL) were tested in the clinical laboratory. Continuous data of gastric juice were compared between each group using the independent-samples Mann-Whitney U-test and their relationship was analysed by Spearman's rank correlation test and Fisher's linear discriminant analysis. Histopathology of DGR patients and 23 patients with chronic atrophic gastritis was compared by clinical pathologists. Using the Independent-samples Mann-Whitney U-test, DGR index (DGRi) was calculated in 28 patients of DGR group and 19 persons of control group who were subjected to hepatobiliary scintigraphy. Receiver operating characteristic curve was made to determine the sensitivity and specificity of these two methods in the diagnosis of DGR. RESULTS: The group of patients with DGR showed a statistically higher prevalence of epigastric pain in comparison with control group. There was no significant difference between the histology of gastric mucosa with atrophic gastritis and duodenogastric reflux. The bile acid levels of DGR patients were significantly higher than the control values (Z: TBA: -8.916, DBIL: -3.914, TBIL: -6.197, all P < 0.001). Two of three in the DGR group have a significantly associated with each other (r: TBA/DBIL: 0.362, TBA/TBIL: 0.470, DBIL/TBIL: 0.737, all P < 0.001). The Fisher's discriminant function is followed: Con: Y = 0.002TBA + 0.048DBIL + 0.032TBIL - 0.986; Reflux: Y = 0.012TBA + 0.076DBIL + 0.089TBIL - 2.614. Eighty-four point zero five percent of original grouped cases were correctly classified by this method. With respect to the DGR group, DGRi were higher than those in the control group with statistically significant differences (Z = -5.224, P < 0.001). Twenty eight patients (59.6%) were deemed to be duodenogastric reflux positive by endoscopy, as compared to 37 patients (78.7%) by hepatobiliary scintigraphy. CONCLUSION: The integrated use of intragastric bile acid examination and scintigraphy can greatly improve the sensitivity and specificity of the diagnosis of DGR.

[Characteristics of duodenogastric reflux in duodenal ulcer patients and its dynamics after Helicobacter pylori eradication].

UNLABELLED: Studying role of duodenogastric reflux (DGR) in pathogenesis and sanogenesis of duodenal ulcer (DU). MATERIAL AND METHODS: 233 DU patients (92 patients with a mild, 45--with modern and 96--with the complicated current of disease) are surveyed. Control group were 100 healthy volunteers. Clinical research, endoscopy and 24-hours pH-metria was carried out. In a year after eradication Helicobacter pylori (Hp) 30 patients are repeatedly surveyed. RESULTS: at healthy acidity more low, and DGR above and more for a long time, than at DU patients. DU was especially supressed at complicated current DU. Eradication Hp was accompanied by acidity normalization only at mild DU, and at complicated DU--is not present. CONCLUSION: at healthy people DGR arises in reply to antrum's acidification and has compensative value, and at DU there is the considerable suppression leading to insufficiency of antrum's alkalization. After eradication Hp normalization DGR is marked only at mild current DU.

[What contributes to the transformation of Helicobacter pylori from symbiont into the etiopathogenetical factor of duodenal ulcer?].

UNLABELLED: The aim was to study the relationship duodenogastral reflux (DGR) and Helicobacterpylori infection (Hp) at duodenal ulcer (DU). MATERIAL AND METHODS: Group 1-50 patients with uncomplicated course of DU, Group 2-75 patients with destructive complications of DU; Group 3-40 "healthy" volunteers. It was performed daily EGDS, pH meter, semi-quantitative assessment of contamination of the Hp. RESULTS: The acidity in the body of the stomach was highest in group 2, and lowest--in group 3, patients diagnosed DU night rush giperatsidnosti. In the night period patients from the 1st and 3rd groups were recorded an increase of antral pH, including the expense of growth duration of DGR, while in group 2 reflux was extremely short. The maximum Hp dissemination was in a bulb at fetomaternal of DU. CONCLUSIONS: in healthy individuals DGR intragastral involved in the regulation of pH, in patients with uncomplicated DU while reducing the duration of this resonance persists compensation of antral alkalization, and complications throughout the DGR sharply depressed, which is accompanied by severe decompensation alkalization of antrum. Bulbs semination with Hp inversely proportional to the intensity of this resonance.

[Condition of the gastric mucosa in patients with duodeno-gastric reflux].

The article examines the state of the antral mucosa of the stomach in 43 young patients with duodeno-gastric reflux without any clinical manifestations. In 69.9% of investigated revealed changes in the gastric mucosa, characteristic of reflux gastritis. The comparative characteristic of stereometric indicators of cellular elements, infiltrated own plate of a mucous membrane of a stomach is spent at a reflux-gastritis and the mixed gastritis (at presence Helicobacter pylori). Article is illustrated by 2 tables.

The secretory phospholipase A2 gene is required for gastroesophageal reflux-related changes in murine esophagus.

BACKGROUND: The initial response of esophageal mucosa to gastroduodenal reflux is inflammation and hyperplasia. Secretory phospholipase A(2) (sPLA(2)) is a known mediator of gut inflammation, and its levels are increased in Barrett's esophagus. We hypothesized that the sPLA(2) gene is required to produce esophageal mucosal hyperplasia in response to gastroduodenal reflux. METHODS: C57BL/6 (n = 5) sPLA(2) (-/-) mice and C57BL/6( Cg-Tg(PLA2G2A)703N16 ) mice (n = 4) sPLA(2) (-/+) underwent a side-to-side surgical anastomosis between the duodenum and gastroesophageal junction (DGEA). Control animals [sPLA(2) (-/-) (n = 5), sPLA(2) (-/+) (n = 4)] underwent laparotomy with incision and repair of the esophagus. Tissue was harvested after 4 weeks, and H&E staining was performed to quantify esophageal mucosal thickness. Ki67 and sPLA(2) immunostaining were performed to quantitate differences in cell division and sPLA(2) expression. RESULTS: Mice expressing human sPLA(2) had a 2.5-fold increase in thickness of the esophageal mucosa as compared to controls (p = 0.01). A 6.5-fold increase in proliferation (p = 0.02) and a twofold increase in sPLA(2) expression (p = 0.04) were demonstrated in animals exposed to gastroduodenal reflux. CONCLUSIONS: The presence of sPLA(2) is necessary for early mucosal hyperplasia produced by exposure of the esophagus to gastroduodenal contents. sPLA(2) expression is upregulated by gastroduodenal reflux, strengthening its role as a critical mediator of early mucosal hyperplasia.

Sphincter of Oddi hypomotility and its relationship with duodenal-biliary reflux, plasma motilin and serum gastrin.

AIM: To detect whether patients with a T tube after cholecystectomy and choledochotomy have duodenal-biliary reflux by measuring the radioactivity of Tc99m-labeled diethylene triamine penta-acetic acid (DTPA) in the bile and whether the patients with duodenal-biliary reflux have sphincter of Oddi hypomotility, by measuring the level of plasma and serum gastrin of the patients. Finally to if there is close relationship among sphincter of Oddi hypomotility, duodenal-biliary reflux and gastrointestinal peptides. METHODS: Forty-five patients with a T tube after cholecystectomy and choledochotomy were divided into reflux group and control group. The level of plasma and serum gastrin of the patients and of 12 healthy volunteers were measured by radioimmunoassay. Thirty-four were selected randomly to undergo choledochoscope manometry. Sphincter of Oddi basal pressure (SOBP), amplitude (SOCA), frequency of contractions (SOF), duration of contractions (SOD), duodenal pressure (DP) and common bile duct pressure (CBDP) were scored and analyzed. RESULTS: Sixteen (35.6%) patients were detected to have duodenal-biliary reflux. SOBP, SOCA and CBDP in the reflux group were much lower than the control group (t=5.254, 3.438 and 3.527, P<0.001). SOD of the reflux group was shorter than the control group (t=2.049, P<0.05). The level of serum gastrin and plasma motilin of the reflux group was much lower than the control group (t= -2.230 and -2.235, P<0.05). There was positive correlation between the level of plasma motilin and SOBP and between the level of serum gastrin and SOBP and CBDP. CONCLUSION: About 35.9% of the patients with a T tube after cholecystectomy and choledochotomy have duodenal-biliary reflux. Most of them have sphincter of Oddi hypomotility and the decreased level of plasma motilin and serum gastrin. The disorder of gastrointestinal hormone secretion may result in sphincter of Oddi dysfunction. There is a close relationship between sphincter of Oddi hypomotility and duodenal-biliary reflux.

Detection of endogenous DNA adducts, O-carboxymethyl-2'-deoxyguanosine and 3-ethanesulfonic acid-2'-deoxycytidine, in the rat stomach after duodenal reflux.

The endogenous DNA adducts O(6)-carboxymethyl-deoxyguanosine (O(6)-CM-dG) and 3-ethanesulfonic acid-deoxycytidine (3-ESA-dC) are produced from N-nitroso bile acid conjugates, such as N-nitrosoglycocholic acid (NO-GCA) and N-nitrosotaurocholic acid (NO-TCA), respectively. Formation of these DNA adducts in vivo was here analyzed by 32P-postlabeling in the glandular stomach of rats subjected to duodenal content reflux surgery. In this model, all duodenal contents, including bile acid conjugates, flow back from the jejunum into the gastric corpus. The levels of O(6)-CM-dG found at 4 and 8 weeks after surgery were 40.9 +/- 9.4 and 56.3 +/- 3.2 per 10(8) nucleotides, respectively, whereas the sham operation groups had values of 5.8 +/- 2.3 and 5.9 +/- 0.5 per 10(8) nucleotides. Moreover, adduct spots corresponding to 3-ESA-dC were detected in both duodenal reflux and sham operation groups and levels in the duodenal reflux groups were around four-fold elevated at 11.2 +/- 1.0 and 8.9 +/- 1.0 per 10(8) nucleotides after 4 and 8 weeks, respectively. When the duodenal reflux animals were treated with a nitrite trapping agent, thiazolidine- 4-carboxylic acid (thioproline, TPRO), the levels of O(6)-CM-dG and 3-ESA-dC were reduced to the same levels as in the sham operation animals. These observations suggest that NO-TCA and NO-GCA are formed by nitrosation of glycocholic acid and taurocholic acid, respectively, and these nitroso compounds produce DNA adducts in the glandular stomach of rats subjected to duodenal content reflux surgery.

[Cyclooxygenase (COX)-2 expression in a rat duodenoesophageal reflux model and chemoprevention of adenocarcinoma by the selective COX-2 inhibitor nimesulide].

The aim of this study is to investigate the cyclooxygenase (COX)-2 expression in esophageal epithelium of rat duodenoesophageal reflux model and the effect of a selective COX-2 inhibitor on esophageal adenocarcinogenesis in rats. A series of rats underwent a duodenoesophageal reflux procedure and were divided into 2 groups. One group was given commercial chow (control group), and the other group was given experimental chow containing nimesulide, a selective COX-2 inhibitor (nimesulide group). The animals were sacrificed sequentially after surgery and esophageal examinations were performed. In the control group, esophagitis, Barrett's esophagus (BE) and adenocarcinoma (EAC) were observed, and the frequency of these conditions increased with time. COX-2 expression, PGE(2) level and proliferative activity were up-regulated, predominantly in the inflamed esophageal epithelia, from the 10(th) week. In the nimesulide group, the esophagitis was mild and the frequency of BE was significantly lower than the control group, while EAC was not observed throughout the experiment. PGE(2) level and proliferative activity were lower in the nimesulide group than in the control group. COX-2 may play an important role in esophageal carcinogenesis through the activation of the inflammation-metaplasia-adenocarcinoma sequence. Nimesulide is effective in preventing BE and EAC by suppressing COX-2 activity.

Biliary reflux and non-acid reflux are two distinct phenomena: a comparison between 24-hour multichannel intraesophageal impedance and bilirubin monitoring.

OBJECTIVE: Duodenogastroesophageal reflux (DGER) can greatly increase microscopic and macroscopic esophageal mucosal damage caused by acid. The aim of this study was simultaneously to assess the chemical composition of DGER by detecting bilirubin in the refluxate by means of Bilitec and describe its pH and physical properties by impedance monitoring, in order to prove that non-acid reflux and biliary reflux are two distinct phenomena. MATERIAL AND METHODS: Twenty patients with gastroesophageal reflux disease (GERD) with symptoms refractory to conventional proton-pump inhibitor (PPI) therapy or with atypical GERD symptoms were included in the study. All patients underwent upper gastrointestinal endoscopy and simultaneous Bilitec and intraeosophageal impedance (IIM) and pH monitoring. In the majority of patients (16/20), the tests were performed while assuming a standard PPI dose. RESULTS: Pathological bilirubin exposure, as defined by intraesophageal bilirubin absorbance above 0.14 for more than 3.9% of the time, was present in 9 cases, 6 of them with normal values of non-acid reflux, as detected by IIM. A pathological non-acid reflux, as defined by an IIM showing a percentage time with non-acid reflux greater than 1.4%, was observed in 5 patients, 2 of whom had no pathological biliary reflux, as detected by Bilitec. No correlation was found between the two indices, as expressed by an r-value of -0.12 (p>0.05). CONCLUSIONS: Our study confirms that biliary reflux and non-acid reflux as detected by Bilitec and by IIM, respectively, are two distinct phenomena that require different techniques in order to be assessed in humans.

Duodenal reflux leads to down regulation of DNA mismatch repair pathway in an animal model of esophageal cancer.

BACKGROUND: Gastroduodenal reflux is implicated in esophageal carcinogenesis. This effect is mediated by reactive oxygen species. We hypothesized that this is mediated by DNA mismatch lesion 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxoG), which is repaired by the Mut Y homologue (MYH). We tested the effect of reflux, either alone or in combination with the human dietary mutagen methyl-n-amyl nitrosamine (MNAN), on DNA damage in adenocarcinoma and squamous cell cancer of the esophagus in a rat model. METHODS: Reflux was promoted in male Sprague-Dawley rats by duodenoesophageal anastomosis (8 weeks) without gastric bypass. MNAN treatment (25 mg/kg per week intraperitoneally for four doses) commenced at 10 weeks age. Ten animals served as controls. Quantification of 8-oxoG was performed by using immunohistochemistry, and MYH was analyzed by Western blot. Apoptosis was assessed by terminal deoxynucleotide transferase-mediated deoxy uridine triphosphate nick-end labeling (TUNEL), cytochrome C, and caspase. RESULTS: Tumors (adenocarcinoma) developed in 15 (50%) of 30 animals with reflux alone; this increased to 26 (86.6%) of 30 when reflux was combined with MNAN treatment, with tumor histology consistent with adenosquamous and squamous cell cancer. DNA damage, as reflected by positive 8-oxoG staining in reflux groups, was significantly increased compared with control (p < 0.01), and this was maximal in tissues with malignant transformation. Protein levels of the DNA repair enzyme MYH were significantly less in tissues subjected to reflux compared with controls (p < 0.05). TUNEL, cytochrome C, and caspase positivity confirmed increased apoptosis in cancer lesions. CONCLUSIONS: Gastroduodenal reflux leads to increased DNA damage and downregulation of the DNA mismatch repair pathway. This pathway has an important role in esophageal carcinogenesis in rats.

Bile acids and Barrett's oesophagus: a sine qua non or coincidence?

BACKGROUND: Barrett's oesophagus (BO), a premalignant condition associated with the development of oesophageal adenocarcinoma (OAC), is thought to be a consequence of chronic duodeno-gastro-oesophageal reflux. Of the refluxates, bile acids, either alone or in combination with acid, are probably the most important. METHODS: Analysis of the literature on the role played by bile acids in inducing BO and/or progression to OAC. RESULTS: Combined pH and Bilitec 2000 (as a measure of bile reflux) monitoring and oesophageal aspiration studies in humans suggest a combined role for bile acids, particularly taurine conjugated bile acids, in causing oesophageal mucosal injury. Evidence from animal models has demonstrated that duodenal juice alone is also able to induce BO and/or OAC. Likewise, ex vivo studies with biopsies from BO patients show that increased proliferation and cyclo-oxygenase-2 expression are present after a pulsed exposure to acid or conjugated bile acids, but not if acid and bile acids are combined. Proton-pump inhibitors (PPIs) have been shown to decrease the biliary component of the refluxate. There is some evidence that PPIs are able to reduce neoplastic progression in BO. On the other hand, chronic PPIs can also stimulate bacterial overgrowth, which can result in increased production of secondary bile acids, particularly deoxycholic acid, in the stomach. Deoxycholic acid has been demonstrated to have a tumour-promoting capacity. CONCLUSIONS: It is unknown what factors of the refluxate (acid and/or bile) induce BO and/or promote carcinogenesis, but there is evidence that secondary bile acids play a role. A better understanding of the molecular steps involved in the induction of BO, and the role of bile acids herein, may identify targets at which preventive therapies can be directed.

[Quantitative-qualitative assessment of duodenogastric reflux at 24-h pH-metry].

AIM: To study characteristics (other than duration) of duodenogastric reflux (DGR), correlations of secretory function and DGR characteristics with gastroduodenal disorders (ulcer, chronic hyperacid gastritis). MATERIAL AND METHODS: A total of 110 patients were examined with 24-h pH-metry: 68 patients with duodenal ulcer (DU), 15 patients with gastric ulcer (GU), 27 patients with chronic hyperacid gastritis (CHG). Mean levels of pH and duration of hyperacidity in the body and an antral part of the stomach, duration of DGR, pH in the body and antral part of the stomach depending on DGR severity were studied. RESULTS: DGR was registered almost in all the patients with DU, GU and CHG. Groups of the patients differed by duration and height" of the DGR. CONCLUSION: Patients with DU are characterized by low refluxes which do not reach gastric body.

[Assessment of duodenogastric reflux 24h variability in subjects with functional dyspepsia]. / Ocena zmiennosci dobowej refluksu dwunastniczo-zoladkowego u osób z dyspepsja czynnosciowa.

Symptoms of functional dyspepsia demonstrate significant variability, among others dependently on the time of the day and on consumed meals. The aim of the study was to find out whether duodenogastric reflux is observed in subjects with nonulcer (NUD) and dysmotor dyspepsia (DD) and whether its intensification changes within 24 h. Investigations comprised 25 subjects with NUD and 25 with DD, aged 19-43 years after exclusion of other diseases and H. pylori infection. The gastric content of bilirubin was registered with Bilitec 2000 Synectics Medical. Duodenogastric reflux episodes were observed in both groups but their intensification and 24h dynamics were differentiated. In subjects with DD total reflux index was significantly higher than in those with NUD (mean=18.0+/-9.5% and mean=6.3+/-4.1%; p<0.05). These differences were particularly visible in after meal (mean=21.2+/-7.9% and mean=10.4+/-6.6%; p<0.01) and night time (mean=8.7+/-3.6% and mean=2.9+/-0.9%; p<0.01). The results of the study indicate that bilimetry may be useful in differentiation of the form of dyspepsia and in selection of rational therapy.

Effects of duodenogastric reflux on gastrin cells, somatostatin cells and serotonin cells in human antral gastric mucosa.

Duodenogastric reflux (DGR) has been found to give rise to a hypochlorhydria secondary to alkaline reflux. We investigated whether there is a link between DGR and the gastrin, somatostatin, and serotonin cell numbers and the granular content of gastrin, somatostatin, and serotonin in endocrine cells in human antral mucosa. We investigated 38 selected Helicobacter pylori-negative patients with visual primary excessive DGR in upper endoscopy and symptoms of epigastric pain and bile vomiting. Ten control patients were included in this study. None of the patients had peptic ulcer or had received any medication. Antrum (10 biopsies from five different zones: the lesser and major curvature, the anterior and posterior wall, and the pylorus) and corpus (two biopsies from major curvature about 10 cm below the cardia) biopsy specimens were collected for routine histology, as well as for light and electron immunohistochemistry. In patients without atrophy or intestinal metaplasia and in patients with mild atrophy or mild intestinal metaplasia, the number of gastrin and somatostatin cells was not different from that in controls. In moderate atrophy or moderate intestinal metaplasia, however, the number of gastrin and somatostatin cells decreased. Serotonin cell number was significantly higher in all patients with DGR as compared with controls. The mean somatostatin granular content was increased (3.6+/-0.2 vs. 3.2+/-0.1). In addition, lysosomes with engulfed somatostatin granules were found. The mean serotonin granular content was decreased (2.3+/-0.3 vs. 2.9+/-0.3), while the mean gastrin granular content remained unchanged (2.5+/-0.3 vs. 2.4+/-0.2). Ultrastructurally, the granules in serotonin-positive cells corresponded to the gastric variant or to the intestinal variant of serotonin cells. The endocrine cells were found to have few granules positive for serotonin. It is concluded that DGR inhibits somatostatin granular release, but stimulates both serotonin granular release and serotonin cell growth.