Proton pump inhibitor in the prevention of upper gastrointestinal mucosal injury associated with dual antiplatelet therapy after coronary artery bypass grafting (DACAB-GI-2): study protocol for a randomized controlled trial.

BACKGROUND: Dual antiplatelet therapy (DAPT) is recommended in secondary prevention after coronary artery bypass grafting (CABG), but it is inevitably associated with the risk of bleeding, of which gastrointestinal bleeding accounts for more than half. Proton pump inhibitors (PPIs) may increase the risk of major cardiovascular adverse events when reducing the risk of upper gastrointestinal bleeding. Therefore, the optimal duration of a PPI in combination with DAPT is unclear. METHODS: The "Proton Pump Inhibitor Preventing Upper Gastrointestinal Injury in Patients on Dual Antiplatelet Therapy after CABG" (DACAB-GI-2) study is a prospective, single-center, open-label, parallel, randomized controlled trial. A total of 232 eligible subjects who are scheduled or initiated on DAPT (clopidogrel plus aspirin or ticagrelor plus aspirin) for 12 months immediately after CABG will be enrolled and be randomized in a 1:1 ratio to either a 12-month pantoprazole treatment arm or a 1-month treatment arm. The primary outcome is to assess the rate of gastroduodenal erosions and ulcers evaluated by esophagogastroduodenoscopy (EGD) within 12 months after randomization, based on the modified Lanza score. Secondary outcomes include reflux esophagitis and upper gastrointestinal bleeding. Other pre-specified outcomes include major adverse cardiovascular events, graft failure, and all-cause death. DISCUSSION: This study aims to compare the efficacy and safety of 12 months and 1 month of pantoprazole treatment in preventing DAPT-related upper gastrointestinal mucosal injury after CABG. TRIAL REGISTRATION: ClinicalTrials.gov NCT03908593 .

Observation on dynamic changes of gastrointestinal mucosal injury in rats with acute stage of cerebral infarction / 中国中西医结合急救杂志

Objective To investigate the dynamic characteristic changes of gastrointestinal mucosa and its relationship with disease progression in rats with acute cerebral infarction. Methods Fifty-six male Wistar rats were selected as the study subjects, and they were divided into three groups: normal control, sham operation and cerebral infarction model groups by random number table method. The middle cerebral artery occlusion (MCAO) model was prepared by the modified Longa thread embolic method. The levels of gastrin (GAS) were monitored in each group after modeling for 24 hours, 4 days and 7 days; after the rats were killed, the sections of gastric antrum and small intestine were taken and stained with hematoxylin-eosin (HE) staining method, the histopathological changes of gastric and small intestinal mucosa were observed under light microscope, in the mean time the gastric and small intestinal mucosal pathological scores were also performed, and the differences of pathological scores among the three groups were compared. Results There were no statistical significant differences in GAS, gastrointestinal mucosa and small intestinal mucosal pathological scores between the normal control group and sham operation group at each time point (all P > 0.05); the GAS level in cerebral infarction model group was decreased gradually with time prolongation, reaching the lowest level 7 days after modeling, but the GAS level in cerebral infarction model group was significantly higher than that in normal group and shamoperation group (ng/L: 205.02±7.68 vs. 130.51±8.03, 145.29±7.68, both P < 0.05). The pathological scores of gastrointestinal mucosa and small intestinal mucosa in the cerebral infarction model group were increased first and then decreased with time prolongation, peaked on 4th day and decreased significantly on 7th day, the pathological scores of gastrointestinal mucosa and small intestinal mucosa in the cerebral infarction model group at each time point were significantly higher than those in the normal control group and sham-operated group (gastric mucosal pathological score: 82.50±2.95 vs. 21.38±1.57, 36.10±3.41; small intestinal mucosal pathological score: 62.00±2.78 vs. 18.25±1.39, 25.55±1.75, all P < 0.05). Under light microscopy, the normal control group showed complete normal morphological appearance, normal structure, orderly arrangement of villi and no infiltration of inflammatory cells; in shamoperation group, inflammatory cells infiltrated the lamina propria at each time point, and there were villi slightly uneven, enlarged stroma, congestion, edema occasionally seen and no obvious ulcer; in cerebral infarction model group, the various layers of gastrointestinal mucosal were not very clear, the glands were arranged irregularly and the capillaries dilated, and in part of tissues, congestion, hemorrhage, edema and inflammatory cell infiltration were seen obviously. Conclusion The injury of gastrointestinal mucosa in acute stage of cerebral infarction should be related to the stress stimulation and disease progress of cerebral infarction itself, not due to the abnormal secretion of GAS.

Exploration of establishing a tree shrew model of chronic gastrointestinal mucosal injury / 中国比较医学杂志

Objective To explore the feasibility of establishing a tree shrew model of chronic gastrointestinal mucosal injury. Methods A total of 12 adult male tree shrews were randomly divided into 3 groups. The experimental groups 1 and 2 were administered with intraperitoneal injection of 2 mg/(kg·d)and 1 mg/(kg·d)of 1-methyl-4-phenyl-1,2, 3,6-tetrahydropyridine(MPTP)once every day for 56 days, respectively. The control group was given the same volume of sterile saline at the corresponding time points. Changes in the body weight of the tree shrews were observed. The contents of dopamine in the cerebrospinal fluid were detected. Gastrointestinal morphology was observed by stereoscope and histopathological changes of the gastrointestinal mucosa were examined by HE staining. Results The body weight and the contents of dopamine in the cerebrospinal fluid of the tree shrews in the model group were significantly decreased(P< 0.05 for both). Pathological changes to some extent of the gastric antrum, the gastric body and the duodenum were observed, without obvious differences between the 2 mg/kg group and the 1 mg/kg group. No obvious changes were found in the control group. Conclusions Long-term intraperitoneal injection with a low dose of MPTP is a feasible method for the establishment of a tree shrew model of chronic gastrointestinal mucosal injury. The optimal dose is 2 mg/(kg·d)every day for 56 days.

Determination of the adequate dosage of rebamipide, a gastric mucoprotective drug, to prevent low-dose aspirin-induced gastrointestinal mucosal injury.

Small intestinal mucosal injury caused by low-dose aspirin is a common cause of obscure gastrointestinal bleeding. We aimed to investigate the protective effects and optimal dose of rebamipide for low-dose aspirin-induced gastrointestinal mucosal injury. In this prospective randomized trial, 45 healthy volunteers (aged 20-65 years) were included and divided into three groups. The groups received enteric-coated aspirin 100 mg (low-dose aspirin) plus omeprazole 10 mg (Group A: proton pump inhibitor group), low-dose aspirin plus rebamipide 300 mg (Group B: standard-dose group), or low-dose aspirin plus rebamipide 900 mg (Group C: high-dose group). Esophagogastroduodenoscopy and video capsule endoscopy were performed, and the fecal occult blood reaction and fecal calprotectin levels were measured before and two weeks after drug administration. Although the fecal calprotectin levels increased significantly in Group A, they did not increase in Groups B and C. The esophagogastroduodenoscopic and video capsule endoscopic findings and the fecal occult blood test findings did not differ significantly among the three groups. In conclusion, standard-dose rebamipide is sufficient for preventing mucosal injury of the small intestine induced by low-dose aspirin, indicating that high-dose rebamipide is not necessary.

Sodium alginate ameliorates indomethacin-induced gastrointestinal mucosal injury via inhibiting translocation in rats.

AIM: To investigate the effects of sodium alginate (AL-Na) on indomethacin-induced small intestinal lesions in rats. METHODS: Gastric injury was assessed by measuring ulcerated legions 4 h after indomethacin (25 mg/kg) administration. Small intestinal injury was assessed by measuring ulcerated legions 24 h after indomethacin (10 mg/kg) administration. AL-Na and rebamipide were orally administered. Myeloperoxidase activity in the stomach and intestine were measured. Microvascular permeability, superoxide dismutase content, glutathione peroxidase activity, catalase activity, red blood cell count, white blood cell count, mucin content and enterobacterial count in the small intestine were measured. RESULTS: AL-Na significantly reduced indomethacin-induced ulcer size and myeloperoxidase activity in the stomach and small intestine. AL-Na prevented increases in microvascular permeability, superoxide dismutase content, glutathione peroxidase activity and catalase activity in small intestinal injury induced by indomethacin. AL-Na also prevented decreases in red blood cells and white blood cells in small intestinal injury induced by indomethacin. Moreover, AL-Na suppressed mucin depletion by indomethacin and inhibited infiltration of enterobacteria into the small intestine. CONCLUSION: These results indicate that AL-Na ameliorates non-steroidal anti-inflammatory drug-induced small intestinal enteritis via bacterial translocation.

The pathophysiology of non-steroidal anti-inflammatory drug (NSAID)-induced mucosal injuries in stomach and small intestine.

Non-steroidal anti-inflammatory drugs are the most commonly prescribed drugs for arthritis, inflammation, and cardiovascular protection. However, they cause gastrointestinal complications. The pathophysiology of these complications has mostly been ascribed to non-steroidal anti-inflammatory drugs' action on the cyclooxygenase inhibition and the subsequent prostaglandin deficiency. However, recent clinical demonstrated the prevalence of non-steroidal anti-inflammatory drugs-induced small intestinal mucosal injury is more often than previously expected. In this review, we discuss the defense mechanisms of stomach, and the pathophysiology of non-steroidal anti-inflammatory drugs-induced injury of stomach and small intestine, especially focused on non-steroidal anti-inflammatory drugs' action on mitochondria.