Could we use PD-1 and PD-L1 expression on lymphocytes and monocytes as predictive markers for prognosis of acute biliary pancreatitis?

PURPOSE: This study aimed to assess the significance of immunophenotyping and serum cytokines in predicting the clinical progression of acute biliary pancreatitis (ABP). MATERIALS AND METHODS: Cytokine levels, T-helper, cytotoxic T, natural killer (NK) cells, monocytes, HLA-DR, and PD-1, as well as PDL-1 immune checkpoints, were measured in ABP patients at the time of diagnosis and compared with results from healthy volunteers. The study also compared leukocyte counts, hematocrit, immunophenotyping results, cytokine statuses, and PD-1, PDL-1 expression between healthy volunteers and ABP subgroups categorized by pancreatitis severity. RESULTS: The study included 65 ABP patients and 20 healthy volunteers. Significant differences were observed between groups in hematocrit, leukocyte counts, total monocytes, lymphocytes, CD3+ total T cells, CD4+ Th cells, PD-1 expression on CD4+ and CD8+T lymphocytes, HLA-DR expression on CD14+ monocytes, NK cells, PD-L1 expression on CD14+ monocytes, classical and intermediate monocytes, as well as levels of IL-6, IL-8, IL-10, IL-18, and IL-33 cytokines. Moderate correlations were found with lymphocyte counts, PD-1+CD4+ cells, PD-L1+CD14+ cells, and strong correlations with HLA-DR+CD14+ cells. Hematocrit, CD3+ total T cells, NK cells, CD4+PD-1 + T cells, and CD8+PD-1 + T cells showed independent associations with the severity of ABP. Lymphocyte counts, CD14+HLA-DR+ cells, CD14+PD-L1+ cells, CD4+PD-1 + T cells, classical, and intermediate monocytes exhibited the highest Area Under the Curve rates in determining organ failure. CONCLUSIONS: Hematocrit, lymphocyte counts, CD14+HLA-DR+ cells, CD14+PD-L1+ cells, and intermediate monocytes emerged as parameters most closely associated with the severity and these parameters could be useful in predicting the severity of ABP.

New CagL Amino Acid Polymorphism Patterns of Helicobacter pylori in Peptic Ulcer and Non-Ulcer Dyspepsia.

Background and Objectives: Helicobacter pylori infection is associated with chronic gastritis, ulcers, and gastric cancer. The H. pylori Type 4 secretion system (T4SS) translocates the CagA protein into host cells and plays an essential role in initiating gastric carcinogenesis. The CagL protein is a component of the T4SS. CagL amino acid polymorphisms are correlated with clinical outcomes. We aimed to study the association between CagL amino acid polymorphisms and peptic ulcer disease (PUD) and non-ulcer dyspepsia (NUD). Materials and Methods: A total of 99 patients (PUD, 46; NUD, 53) were enrolled and screened for H. pylori by qPCR from antrum biopsy samples. The amino acid polymorphisms of CagL were analyzed using DNA sequencing, followed by the MAFFT sequence alignment program to match the amino acid sequences. Results: Antrum biopsy samples from 70 out of 99 (70.7%) patients were found to be H. pylori DNA-positive. A positive band for cagL was detected in 42 out of 70 samples (PUD, 23; NUD, 19), and following this, these 42 samples were sequenced. In total, 27 different polymorphisms were determined. We determined three CagL amino acid polymorphism combinations, which were determined to be associated with PUD and NUD. Pattern 1 (K35/N122/V134/T175/R194/E210) was only detected in PUD patient samples and was related to a 1.35-fold risk (p = 0.02). Patterns 2 (V41/I134) and 3 (V41/K122/A171/I174) were found only in NUD patient samples and were linked to a 1.26-fold increased risk (p = 0.03). Conclusions: We observed three new patterns associated with PUD and NUD. Pattern 1 is related to PUD, and the other two patterns (Patterns 2 and 3) are related to NUD. The patterns that we identified include the remote polymorphisms of the CagL protein, which is a new approach. These patterns may help to understand the course of H. pylori infection.

Association between Acute Pancreatitis and COVID-19: Could Pancreatitis Be the Missing Piece of the Puzzle about Increased Mortality Rates?

BACKGROUND: The COVID-19 pandemic caused by SARS-CoV-2 commenced in Wuhan China in 2019 and soon spread worldwide. SARS-CoV-2 enters the cell by binding to the ACE II receptor and begins viral replication. The effects and clinical findings of SARS-CoV-2 on the liver, kidney, heart, gastrointestinal (GI) system and especially lungs have been widely discussed. However, the effects on the pancreas-another organ that also expresses ACE II-have not been studied. METHODS: This work prospectively evaluated data from 316 patients who were admitted with a diagnosis of COVID-19 pneumonia. The patients were categorized into three according to the severity of pneumonia (mild, severe, critical). Demographic data, rate of pancreatitis, biochemical parameters, and radiological images from each group were analyzed. The patients were divided into two groups and outcomes were compared: COVID-19 patients with acute pancreatitis (Group P) and without acute pancreatitis (Group C). RESULTS: The median age was 54 (18-87), and the median age for patients with acute pancreatitis was 55 (26-84). As an expected finding, we found a positive correlation between advanced age and mortality (p = 0.0003). 12.6% of the patients had acute pancreatitis. While pancreatitis was not seen in patients on mild status, the rate of pancreatitis was 32.5% in critical patients. Hospitalization and mortality rates were higher in patients with COVID-19 accompanied by acute pancreatitis (p = 0.0038 and p < 0.0001, respectively). C-Reactive Protein (CRP) and ferritin were significantly higher in those who had pancreatitis (p < 0.0001). D-Dimer and procalcitonin levels had only a small difference (p = 0.1127 and p = 0.3403, respectively). CONCLUSION: Acute pancreatitis alone is a clinical condition that can lead to mortality and may be one of the reasons for the exaggerated immune response developing in the progression of COVID-19. Our results point out that the presence of pancreatic damage triggered by SARS-CoV-2 can deteriorate the clinical condition of patients and the mortality rate may increase in these patients.

Is Helicobacter pylori eradication required after laparoscopic sleeve gastrectomy?

Introduction: Helicobacter pylori is the most common bacterial infection in humans. H. pylori is now known to be responsible for chronic gastritis, peptic ulcer, B-cell gastric lymphoma, and gastric adenocarcinoma. Laparoscopic sleeve gastrectomy (LSG) is increasingly preferred among surgical treatment methods in obese patients. Aim: To discuss the detection and treatment of H. pylori in patients undergoing LSG surgery. Material and methods: Patients who underwent biopsy with upper gastrointestinal endoscopy in the preoperative and postoperative period of LSG between 2014 and 2019 were included in the study, resulting in a sample of 162 patients who underwent preoperative and postoperative endoscopy. Endoscopic biopsies of these patients were collected in accordance with the preoperative Sydney protocol. The patients did not receive H. pylori-related eradication treatment. Endoscopy was performed to investigate dyspeptic complaints in the postoperative period. The biopsy results obtained in the endoscopy in the postoperative period were compared to those obtained in the preoperative period. Results: Of the 162 patients in our study, 39 were male and 123 were female. All patients were assigned to one of two groups in the preoperative period: H. pylori (+) and H. pylori (-). H. pylori was found to be positive in 99 patients in the preoperative period. H. pylori was negative in 62 patients in the biopsy results of these patients after the LSG. H. pylori was found to be negative in 63 patients in the preoperative period, and 51 patients were H. pylori-negative in the biopsy results of these patients following LSG. These changes were found to be statistically significant when the preoperative and postoperative pathology results were evaluated (p < 0.01). Conclusions: This study showed that LSG reduced the presence of H. pylori.

Pancreatic extragastrointestinal stromal tumor invading the duodenum.

Extragastrointestinal stromal tumors that arise in the pancreas are extremely rare and managing them can be difficult, particularly if located in the head of pancreas. This case report aims to contribute to the existing data in the literature regarding extragastrointestinal stromal tumors with rare and unusual locations. We present a 56-year-old man who presented with recurrent mild right upper quadrant abdominal pain. Abdominal computed tomography and magnetic resonance imaging revealed a mass lesion with a diameter of 10 cm localized in the head of pancreas. Pancreaticoduodenectomy with complete tumor excision was performed. He was discharged on the postoperative day 14. Only 15 extragastrointestinal stromal tumors cases have been reported. Of these 15 cases, tumors were located in the head of pancreas in six cases. Here we report the seventh case of pancreatic extragastrointestinal stromal tumor arising in the head of pancreas and also the largest of these seven tumors.

Effects of melatonin on colonic anastomosis healing following chemotherapy in rats.

INTRODUCTION: This study aimed to investigate the effects of melatonin on the healing of colon anastomosis following chemotherapy. METHODS: 32 rats were randomised into four groups: (a) control group, which underwent sigmoid colon transection and primary anastomosis; (b) melatonin group, which received melatonin daily following anastomosis; (c) 5-fluorouracil (5-FU) group, which received 5-FU for five days prior to anastomosis; and (d) 5-FU+melatonin group, which received 5-FU for five days prior to anastomosis and melatonin daily following anastomosis. The rats were sacrificed on Postoperative Day 7 and anastomotic bursting pressures were measured. The anastomotic segment was extracted for hydroxyproline, luminol and lucigenin measurement and histopathological examination. Blood samples were obtained from the vena cava for measurement of tumour necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1ß) plasma levels. RESULTS: Compared to the 5-FU group, bursting pressures of anastomosis and hydroxyproline levels were significantly higher, while luminol and lucigenin levels were significantly lower, in the control and 5-FU+melatonin groups. In addition, TNF-α and IL-1ß plasma levels were significantly lower in the control and 5-FU+melatonin groups than in the 5-FU group. Histopathological examination showed a significant decrease in inflammation and necrosis formation in the melatonin group when compared to the control group. The positive effect of melatonin was also seen in the rats that received 5-FU. CONCLUSION: Our study results showed that the adverse effects of chemotherapy on the mechanical, biochemical and histopathological parameters of anastomosis healing were attenuated through melatonin treatment.

Preoperative immunonutrition regulates tumor infiltrative lymphocytes and increases tumor angiogenesis in gastric cancer patients.

INTRODUCTION: An increased number of tumor infiltrative lymphocytes (TILs) is considered a favorable prognostic factor in various cancers because it is a marker of antitumoral activity of the immune system. In this prospective, non-randomized clinical trial, we evaluated the impact of preoperative immunonutrition on tumor infiltrative lymphocytes and neoangiogenesis in cancerous tissue in patients with locoregional and resectable gastric adenocarcinoma. MATERIAL AND METHODS: Patients with locoregional and resectable gastric adenocarcinoma were divided non-randomly into two study groups. The first (control) group included patients who had standard nutrition, and the second group included those who had immunonutrition for 7 days before surgery. The biopsy samples taken endoscopically in the preoperative period, as well as the gastrectomy samples, were subjected to immunohistochemical staining for quantitative analysis of CD4, CD8, CD16, CD56, CD31 and CD105 antibodies. Main outcome measures were CD4-to-CD8 ratio and CD105 levels. RESULTS: Fifty patients were included in the study between January 2013 and December 2014. Twenty-five patients were assigned to each of the first and second group. The CD4-to-CD8 ratio and CD105 levels determined in endoscopic biopsy samples were similar in both groups. The CD4-to-CD8 ratio in gastrectomy samples was significantly higher in the first group (p = 0.0001). The CD105 levels in gastrectomy samples were significantly lower in the first group (p = 0.01). CONCLUSIONS: Seven-day preoperative immunonutrition use regulates TILs in gastric cancer patients, but prolonged use increases tumor angiogenesis.

An alternative view on the necessity of EGD before sleeve gastrectomy.

BACKGROUND: Esophagogastroduodenoscopy (EGD) is particularly recommended for choosing a surgical method to be used with asymptomatic patients and for the assessment of symptomatic patients prior to sleeve gastrectomy. The presence of hiatal hernia, for instance, is a relative contraindication. EGD is used for malignancy scanning as well as surgical planning, but seems inefficient in determining postoperative complications. OBJECTIVE: Our aim was to investigate the effectiveness of the pathological evaluation of endoscopic biopsies obtained with esophagogastroduodenoscopy (EGD) according to Sydney classification prior to sleeve gastrectomy in identifying the risk of staple line leak, independently of clinical diagnosis. SETTING: Bakirköy Dr. Sadi Konuk Training and Research Hospital, Department of General Surgery. METHODS: Patients who underwent laparoscopic sleeve gastrectomy between January 2014-December 2016 received preoperative EGD as per the clinic's protocol and upon obtaining ethics board approval and patient consent. Biopsies were taken from the patients according to the Sydney protocol. The pathology results were examined retrospectively by considering the exclusion criteria. The results were given in line with the Sydney classification, and patients with and without Staple Line Leak were statistically compared. RESULTS: A total of 630 patients were enrolled in the study. Of these, 71.1% (n = 448) were female and 28.9% (n = 182) were male. Mean age was 38.9 years (17-68), mean body weight was 130.8kg (94-240) and body mass index (BMI) values were 47.4kg/m2 (36-106). In evaluation of median values, no statistically significant relationship was found between staple line leak and H. pylori occurrence grade (P = 0.438; P>0.05), activation grade (P = 0.568; P>0.05) or intestinal metaplasia grade (P = 0.319; P>0.05). Atrophy (P = 0.001; P<0.01) and chronic inflammation grade (P = 0.026; P<0.05) were significantly higher in Staple Line Leak patients. CONCLUSIONS: EGD prior to sleeve gastrectomy and biopsies obtained in line with the Sydney protocol predict Staple Line Leak risk.

The Importance of Rockall Scoring System for Upper Gastrointestinal Bleeding in Long-Term Follow-Up.

The aim of the study is to examine the importance of Rockall scoring system in long-term setting to estimate re-bleeding and mortality rate due to upper gastrointestinal bleeding. A total of 321 patients who had been treated for upper gastrointestinal bleeding were recruited to the study. Patients' demographic and clinical data, the amount of blood transfusion, endoscopy results, and Rockall scores were retrieved from patients' charts. The re-bleeding, morbidity, and mortality rates were noted after 3 years of follow-up with telephone. Re-bleeding rate was statistically significantly higher in Rockall 4 group compared to Rockall 0 group. Mortality rate was also statistically significantly higher in Rockall 4 group. Rockall risk scoring system is a valuable tool to predict re-bleeding and mortality rates for patients with upper gastrointestinal bleeding in long-term setting.

Single center experience in laparoscopic treatment of gallbladder perforation.

INTRODUCTION: Gallbladder perforation (GBP) is a rare disease with potential mortality. Previous series have reported an incidence of approximately 2-11% and it still continues to be a significant problem for surgeons. AIM: To present our clinical experience with gallbladder perforation. MATERIAL AND METHODS: The records of 2754 patients who received surgical treatment for cholelithiasis between 2010 and 2016 were reviewed retrospectively. One hundred thirty-three patients had gallbladder perforation. Age, gender, time from the onset of symptoms, diagnostic procedures, surgical treatment, morbidity and mortality rates were evaluated. RESULTS: 15.78% of patients had a body mass index > 35. 6.76% had chronic obstructive pulmonary disease, 6.76% had cardiac disease, 10.52% had diabetes and 4.51% had sepsis. American Society of Anesthesiology scores were I in 54.13%, II in 35.33%, III in 6.01% and IV in 4.51% of the patients. 27.81% of patients were diagnosed during surgery. The perforation site was the gallbladder fundus in 69.17%, body in 17.30%, Hartman's pouch in 10.53% and cystic duct in 3% of patients. Treatment modalities were laparoscopic cholecystectomy in 82.71%, open cholecystectomy in 3%, percutaneous drainage catheters + laparoscopic cholecystectomy in 3%, laparoscopic cholecystectomy + fistula repair in 10.53% and open cholecystectomy + fistula repair in 0.75% of patients. Mean length of hospital stay was 1.69 days. Mortality and morbidity rates were 8.27% and 10.52%, respectively. Histopathology results were acute cholecystitis in 69.93%, chronic cholecystitis in 20.30% and acute exacerbation over chronic cholecystitis in 9.77% of patients. CONCLUSIONS: Appropriate classification and management of perforated cholecystitis is essential. Laparoscopic cholecystectomy is a safe and feasible method to decrease morbidity in gallbladder perforations.

Plasma calprotectin level: usage in distinction of uncomplicated from complicated acute appendicitis.

BACKGROUND: The aim of this study was to identify the diagnostic role of plasma calprotectin value for a distinction of presence acute appendicitis and the indifference of uncomplicated from complicated acute appendicitis. METHODS: Plasma calprotectin, white blood cell and C-reactive protein values of 89 patients, who have undergone laparoscopic appendectomy between January 2013 and May 2013 were evaluated. RESULTS: Calprotectin was 91 ng/mL (range 45-538) for acute appendicitis and 47 ng/ml (range 28-205) for the control group. There was a positive, statistically significant relation between calprotectin and C-reactive protein values (r = 0. 292 p = 0. 001, respectively). There was no statistically significant difference was determined between calprotectin and white blood cell values (r = 0. 142 p = 0. 187, respectively). CRP and Cal values were significantly higher in patients with a complicated AA group than in those with uncomplicated AA (p = 0. 014, p = 0. 0001, respectively) whereas white blood cell counts did not differ significantly between two groups (p = 0. 164). CONCLUSION: Plasma calprotectin levels were increased in patients with acute appendicitis and should use in a distinction of uncomplicated from complicated acute appendicitis patients.

Esophageal transection.

Herein, a case of intramural esophageal dissection is reported and the literature is reviewed. Intramural esophageal dissection is a rare but well described condition that is characterized by a laceration between the esophageal mucosa and submucosa but without perforation. A female patient aged 86 years was hospitalized with a diagnosis of abdominal aortic aneurysm. After placement of an aortic stent, she was started on intravenous heparin. After the procedure, the patient had retching and vomiting due to sedative drugs. On the first day after the procedure, the patient experienced sudden-onset chest pain, hematemesis, back pain and odynophagia. A hematoma was detected in the thoracic esophagus, which was opened during endoscopy and began to bleed suddenly owing to air insufflation. A false lumen was visualized within the esophagus. There was no perforation. The patient was followed up conservatively and discharged from the hospital uneventfully. In conclusion, we propose that esophageal transection, a condition that is widely regarded as relatively benign in the literature, has the potential to lead to perforation. It would be expected that most cases of esophageal transection would be managed conservatively.

Rare Complication of Stomas: Peristomal Necrotizing Fasciitis.

INTRODUCTION: A stoma formation is a frequently performed procedure in patients undergoing colorectal surgery. Although stoma formation is a simple process, it should be performed with caution. The aim of this study was to attract physicians' attention to this rare disease and also to identify the surgical and medical treatment options for peristomal necrotizing fasciitis as a rare complication. MATERIALS AND METHODS: Risk factors including age, sex, additional diseases, previous surgical procedures, source of infection, physical findings, and vital signs of 14 patients with peristomal necrotizing fasciitis over a period of 10 years from 2005 to 2015 were retrospectively evaluated. RESULTS: Of the 14 patients, 9 were men and 5 were women. The average age was 63.28 years (range, 45-85 years). Risk factors were also observed: diabetes mellitus, 4 (28.57%); obesity, 3 (21.42%); alcoholism, 1 (7.14%); and malignancy, 10 (71.42%). Prophylactic antibiotic treatment was given to all patients, and they all underwent debridement and stoma replacement. CONCLUSION: Peristomal necrotizing fasciitis is an urgent and mortal disease. Risk factors, physical findings, and infection sources should be determined, and treatment modalities should be applied immediately. Medical treatment and surgical options should be performed, and vacuum devices should also be considered when treating this complication.

Prevention of Postoperative Bile Leak in Partial Cystectomy for Hydatid Liver Disease: Tricks of the Trade.

BACKGROUND: The presence of postoperative bile leak is the major outcome measure for the assessment of operative success in partial cystectomy for hydatid liver disease. However, the optimal operative strategy to reduce the postoperative bile leak rate is yet to be defined. METHODS: Medical records of patients who underwent partial cystectomy for hydatid liver disease between January 2013 and January 2015 were reviewed in this retrospective analysis. All patients were managed with a specific operative protocol. The primary outcome measure was the rate of persistent postoperative bile leak. The secondary outcome measures were the morbidity and mortality rate, and the length of hospital stay. RESULTS: Twenty-eight patients were included in the study. Only one patient (3.6 %) developed persistent postoperative bile leak. The overall morbidity and mortality rate was 17.8 and 0 %, respectively. The median length of hospital stay was 5 days. CONCLUSION: Aggressive preventative surgical measures have led to low persistent bile leak rates with low morbidity and mortality.

In vitro effects of rabeprazole on human pylorus tone.

BACKGROUND/AIMS: It has been reported that proton pump inhibitors induce relaxation in different types of smooth muscles. The aim of this study is to investigate in vitro effects of proton pump inhibitors on human pylorus muscle. METHODS: Pyloric sphincters were studied in 10 patients who were operated for stomach cancer. In isolated organ bath, control and re-sponse to rabeprazole were recorded following contraction with carbachol. During the treatment experiment, while distilled wa-ter was applied during the control experiment in every 5 minutes, rabeprazole was administered in every 5 minutes at doses of 10(-6), 10(-5), 10(-4), and 10(-3) M respectively. Contraction frequencies, maximum contraction values and muscle tones were measured. RESULTS: The contraction frequencies in the control group were greater than the rabeprazole group in the second, third and fourth in-tervals while the maximum contraction values in the rabeprazole group were lower in the fourth interval. Even though muscles tones were not different in both groups during all intervals, it was remarkable that the muscle tone was significantly decreased in the rabeprazole group during the fourth interval compared to the first and second intervals. CONCLUSIONS: In the present study, high doses of rabeprazole reduced contraction frequencies, maximum contraction values, and muscle tone of human pylorus.

Diabetes effect on Quality of Life in the long-term after Limb salvage with Infrageniculate Bypasses accompanied with minor amputations.

UNLABELLED: Objective : To evaluate the quality of life in patients, who had their limbs salvaged with an infrageniculate bypass and minor amputation in the long term and to see if diabetics are prone to worse results. METHODS: The patients with limb salvage following an infrageniculate bypass and minor amputation were asked to complete Short Form 36 at the last follow-up visit. The mean scores in diabetic and non-diabetic population were compared to each other .The mean follow-up period was 58±8 months. Results : Of 142 patients, 40 patients were eligible to be included in the study. 33 (82.5%) patients were male and 7 (17.5%) patients were female. The mean age at the time of intervention was 57±14 (33-83) years. The mean scores for eight domains of SF-36 evaluation ranged from 44 to 67 out of 100. There were no significant differences concerning the mean scores of any dimension between the diabetic and non-diabetic group. Conclusion : Despite a minor amputation, the functional outcome of limb salvage with an infrageniculate bypass is favorable and diabetes does not seem to have negative effect on the functional outcome and Quality of Life.

Increased interleukin 1 and tumor necrosis factor alpha levels after thyroid surgery.

OBJECTIVE: The aim of this study was to consider levels of the proinflammatory cytokines IL-1 and TNFα after thyroid surgery. MATERIAL AND METHODS: A total of 200 patients who underwent total thyroidectomy enrolled in this study. Drain fluid samples were taken. IL-1 and TNFα results and their relationship with other factors were analyzed. RESULTS: There was a positive correlation between IL-1 and hyperthyroidism (rs=0.614, p<0.001), operative time (rs=0.770, p<0.001), and excised thyroid volume (rs=0.829, p<0.001). Moreover, there was a positive correlation between TNFα and hyperthyroidism (rs=0.430, p<0.001), operative time (rs=0.392, p<0.001), and excised thyroid volume (rs=0.398, p<0.001). CONCLUSION: The results of this study showed us that the parameters related to increased proinflammatory cytokine levels after thyroid surgery were hyperthyroidism, operative time, and excised thyroid volume, but this increase did not show us any clinical outcomes related to these parameters.

The effect of rabeprazole on LES tone in experimental rat model.

INTRODUCTION: Despite adequate treatment with proton pump inhibitors (PPIs), symptoms of gastroesophageal reflux disease (GERD) may remain persistent as well as Barrett's esophagus may emerge. It may be proposed that the relaxant effect of PPIs on the smooth muscles may lead to resistance of symptoms. The aim of this study is to investigate effects of rabeprazole on the lower esophageal sphincter (LES) pressure with a rat model. MATERIALS AND METHODS: Sixteen rats were grouped as control and treatment groups. After obtaining LES tissues followed by a 60 min equilibration period for stabilization, contractile response to carbachol was obtained by application of single dose of carbachol to have a final concentration of 10(-6) M in the organ bath. After the contractions reached a plateau, concentration-response relationships for rabeprazole were obtained in a cumulative manner in the treatment group. RESULTS: In the carbachol contracted LES preparations; 1.5 × 10(-6) and 1.5×10(-5) M of rabeprazole caused 6.08% and 11.34% relaxations respectively which were not statistically significant. However, mean integral relaxation value for 4.5 × 10(-5) M of rabeprazole was 17.34% and this relaxation was significant compared with controls. CONCLUSIONS: In the present study, rabeprazole caused no direct significant change in LES tone in the therapeutic dose range applied to the organ bath. However, rabeprazole at the high dose caused a significant decrease in the LES tone.