Hirotoshi Okazaki

Small Bowel Injury by Low-Dose Enteric-Coated Aspirin and Treatment With Misoprostol: A Pilot Study

BACKGROUND & AIMS With capsule endoscopy, the ulcerogenic effect of low-dose enteric-coated aspirin on the small bowel and the therapeutic effect of misoprostol on intestinal injury were evaluated. METHODS Eleven patients who developed gastric ulcers while undergoing low-dose enteric-coated aspirin therapy were enrolled. They continued aspirin therapy while taking proton pump inhibitors (PPIs) for 8 weeks to heal the gastric ulcers. Then misoprostol 200 microg 4 times a day was administered instead of PPIs for 8 weeks. When the patients could not tolerate misoprostol as a result of side effects, they received another 8 weeks of PPI therapy. RESULTS Capsule endoscopy performed after 8 weeks of PPI treatment identified red spots and mucosal breaks in 100% (11/11) and 90.9% (10/11) of patients, respectively. In 7 patients who completed the study protocol, misoprostol significantly decreased the median number of red spots and mucosal breaks, with complete disappearance of mucosal breaks in 4 patients. Intestinal lesions tended not to heal in 3 patients who discontinued misoprostol. CONCLUSIONS Low-dose enteric-coated aspirin frequently damages the small intestine, and misoprostol is effective in the treatment of aspirin-induced enteropathy.

Probiotic Lactobacillus casei strain Shirota prevents indomethacin-induced small intestinal injury: involvement of lactic acid

Inflammatory responses triggered by activation of the lipopolysaccharide (LPS)/Toll-like receptor (TLR) 4 signaling pathway are a key mechanism in nonsteroidal anti-inflammatory drug-induced enteropathy. The aim of this study was to investigate the probiotic effect of Lactobacillus casei strain Shirota (LcS) on indomethacin-induced small intestinal injury. Rats pretreated with viable LcS or heat-killed LcS once or once daily for a week were administered indomethacin by gavage to induce injury. Anti-inflammatory effects of L-lactic acid (1-15 mM) were evaluated in vitro by use of THP-1 cells. One-week treatment with viable LcS prevented indomethacin-induced intestinal injury with increase in the concentration of lactic acid in small intestinal content and inhibited increases in myeloperoxidase activity and expression of mRNA for tumor necrosis factor-alpha (TNF-alpha) while affecting neither TLR4 expression nor the number of gram-negative bacteria in intestinal content, whereas neither heat-killed LcS nor a single dose of viable LcS inhibited intestinal injury. Prevention of this injury was also observed in rats given l-lactic acid in drinking water. Both L-lactic acid and LcS culture supernatant containing 10 mM lactic acid inhibited NF-kappaB activation and increases in TNF-alpha mRNA expression and TNF-alpha protein secretion in THP-1 cells treated with LPS. Western blot analyses showed that both L-lactic acid and LcS culture supernatants suppressed phosphorylation and degradation of I-kappaB-alpha induced by LPS without affecting expression of TLR4. These findings suggest that LcS exhibits a prophylactic effect on indomethacin-induced enteropathy by suppressing the LPS/TLR4 signaling pathway and that this probiotic effect of LcS may be mediated by L-lactic acid.

A prospective, single-blind trial comparing wireless capsule endoscopy and double-balloon enteroscopy in patients with obscure gastrointestinal bleeding

BackgroundWireless capsule endoscopy (CE) and double-balloon enteroscopy (DBE) are new methods enabling diagnostic endoscopy of the entire small intestine. However, which of the two is superior is unclear. We therefore prospectively compared the clinical efficacy of CE and DBE.MethodsWe prospectively examined 32 patients with obscure gastrointestinal bleeding. CE preceded DBE by 1–7 days, and all patients underwent DBE twice, by antegrade and retrograde approaches, to evaluate the entire small intestine. Physicians evaluating the results of CE and DBE were blind to the results of the other method. We evaluated diagnosis, diagnostic yield of the two methods, and clinical outcomes.ResultsCE revealed abnormal findings in 29 (90.6%) of 32 patients. CE definitively or probably detected the sources of bleeding in 23 (71.9%) of the 32 patients, including angioectasias (eight), erosions (seven), ulcers (five), tumor (one), and hemorrhagic polyps (two). DBE definitely or probably detected the sources of bleeding in 21 (65.6%) of the 32 patients, including angioectasias (seven), erosions (four), ulcers (five), tumor (one), hemorrhagic polyps (two) and diverticula (two). CE yielded more abnormal findings than DBE (CE 90.6%, DBE 65.6%) (P = 0.032), although there were no significant differences in diagnostic yield between the methods. We were able to perform additional treatment or biopsy with DBE in 13 patients, including coagulation therapy (ten), endoscopic mucosal resection (one), biopsy (seven), and extraction of retained CE (two).ConclusionsOur results demonstrate the superiority of CE in detecting abnormal lesions, and the superiority of DBE in endoscopic management.

The Traditional Japanese Medicine Rikkunshito Promotes Gastric Emptying via the Antagonistic Action of the 5-HT3 Receptor Pathway in Rats

The traditional Japanese medicine rikkunshito ameliorates the nitric oxide-associated delay in gastric emptying. Whether rikkunshito affects gastric motility associated with 5-hydroxytryptamine (serotonin: 5-HT) receptors or dopamine receptors is unknown. We examined the effects of rikkunshito on the delay in gastric emptying induced by 5-HT or dopamine using the phenol red method in male Wistar rats. 5-HT (0.01–1.0 mg kg−1, i.p.) dose dependently delayed gastric emptying, similar to the effect of the 5-HT3 receptor agonist 1-(3-chlorophenyl) biguanide (0.01–1.0 mg kg−1, i.p.). Dopamine also dose dependently delayed gastric emptying. The 5-HT3 receptor antagonist ondansetron (0.04–4.0 mg kg−1) and rikkunshito (125–500 mg kg−1) significantly suppressed the delay in gastric emptying caused by 5-HT or 1-(3-chlorophenyl) biguanide. Hesperidin (the most active ingredient in rikkunshito) suppressed the 5-HT-induced delayed gastric emptying in a dose-dependent manner, the maximum effect of which was similar to that of ondansetron (0.4 mg kg−1). The improvement obtained by rikkunshito or ondansetron in delaying gastric emptying was completely blocked by pretreatment with atropine. Rikkunshito appears to improve delay in gastric emptying via the antagonistic action of the 5-HT3 receptor pathway.

Anti-inflammatory effects of IL-17A on Helicobacter pylori-induced gastritis

Helicobacter pylori-induced immune responses are skewed toward a T helper (Th) 1 phenotype. IL-17-producing Th17 cells have recently been discovered, and we examined the role of IL-17A in H. pylori-induced gastritis. Six months after inoculation with H. pylori, the mice received an intraperitoneal injection of recombinant IL-17A, anti-IL-17A antibody or irrelevant IgG(2a) for 3days. H. pylori infection markedly increased mRNA for IL-17A. Double immunofluorescence studies showed that IL-17A proteins were expressed on CD4(+) T cells, macrophages, and dendritic cells. H. pylori infection elevated mRNAs for IL-12, IFN-gamma, and TNF-alpha with increase in myeloperoxidase activity, whereas it did not affect mRNAs for IL-4 and IL-5. Neutralization of IL-17A elevated mRNAs for IFN-gamma and TNF-alpha, and myeloperoxidase activity, whereas recombinant IL-17A had a tendency to reduce these parameters. In conclusion, IL-17A exerts anti-inflammatory effects on H. pylori-induced gastritis through suppression of Th1 differentiation.

Risk factors for severe nonsteroidal anti-inflammatory drug-induced small intestinal damage

BACKGROUND Few studies have assessed the risk factors associated with nonsteroidal anti-inflammatory drugs (NSAIDs)-induced small intestinal damage. AIMS To evaluate the risk factors for NSAID-induced enteropathy in patients with rheumatoid arthritis. METHODS A cross-sectional study using capsule endoscopy was conducted. A total of 113 patients who took NSAIDs for over 3 months underwent capsule endoscopies. Endoscopic findings were scored as (0) normal, (1) red spots, (2) 1-4 erosions, (3) >4 erosions, or (4) large erosions/ulcers. Initial scores were grouped into 3 categories: No damage (0-1), mild damage (2), and severe damage (3-4), and the potential risk factors for damage development were assessed. RESULTS Five patients were excluded because of incomplete visualization of the entire small intestine. Fifty-two (47.2%) and 27 (25%) patients had no damage and mild damage, respectively, while the remaining 30 patients (27.8%) had severe damage and significantly decreased hemoglobin levels. In a multivariate logistic regression analysis, ages of 65 years or more (odds ratio [OR], 4.16; 95% confidence interval [CI], 1.51-11.47), proton pump inhibitor usage (OR, 5.22; 95% CI, 1.36-20.11), and histamine H2 receptor antagonist usage (OR, 3.95; 95% CI, 1.28-12.25) were independent risk factors for severe damage. CONCLUSIONS Elderly patients and acid suppressant users are more likely to develop severe NSAID-induced enteropathy.

Efficacy and safety of balloon-occluded endoscopic injection sclerotherapy as a prophylactic treatment for high-risk gastric fundal varices: A prospective, randomized, comparative clinical trial ☆

BACKGROUND No single effective method has yet been established for the prophylactic treatment of gastric fundal varices at high risk for bleeding. A prospective, randomized trial was conducted to compare the efficacy and safety of a new technique, balloon-occluded endoscopic injection sclerotherapy (BO-EIS), to balloon-occluded retrograde transvenous obliteration (B-RTO) for treatment of high-risk gastric fundal varices. METHODS Twenty consecutive patients with gastric variceal diameters of over 5 mm by color Doppler EUS were randomized to undergo either BO-EIS or B-RTO. All patients underwent color Doppler EUS 2 weeks after treatment and EGD every 3 months for assessment of sclerosing effect. RESULTS The gastric varices in all patients except one in the B-RTO group were eradicated with either treatment. The volume of sclerosant used was significantly smaller in patients who underwent BO-EIS (p < 0.05). The endoscopic grade of esophageal varices in 4 of 9 patients worsened after treatment with B-RTO (p < 0.05). The method of randomization used resulted in an uneven distribution of women, although the difference between the groups was not statistically significant. When only men were compared, the results of the study were unchanged. CONCLUSIONS BO-EIS is a safe and effective for treatment of high-risk gastric fundal varices. In contrast to B-RTO, it can be used even in patients without a gastrorenal shunt.

Evaluation of Small Bowel Injury in Patients with Rheumatoid Arthritis by Capsule Endoscopy: Effects of Anti-Rheumatoid Arthritis Drugs

Background and Aim: The medical treatment of rheumatoid arthritis (RA) includes nonsteroidal anti-inflammatory drugs (NSAIDs), low-dose corticosteroids, and disease-modifying antirheumatic drugs (DMARDs). We evaluated the incidence of small bowel injury in RA patients who were taking anti-RA drugs with or without concomitant NSAIDs by capsule endoscopy. Methods: A total of 28 RA patients who took low-dose corticosteroids and/or DMARDs for more than 1 year were enrolled. Results: The incidence of red spots did not differ between the 2 groups: 14 of 16 patients (87.5%) in the NSAID group and 11 of 12 patients (91.7%) in the non-NSAID group. In contrast, the incidence of mucosal breaks was significantly higher in the NSAID group than in the non-NSAID group: mucosal breaks were detected in 13 of 16 patients (81.3%) and 4 of 12 patients (33.3%) in the NSAID and non-NSAID groups, respectively. In the NSAID group, mucosal breaks developed in users of preferential cyclooxygenase-2 inhibitors at a frequency similar to that in users of traditional NSAIDs. Conclusion: Patients taking anti-RA drugs may have an increased frequency of small bowel injury regardless of NSAID use, and NSAID use may be associated with an increased incidence of severe small bowel injury.

Usefulness of Non-Magnifying Narrow-Band Imaging in Screening of Early Esophageal Squamous Cell Carcinoma: A Prospective Comparative Study Using Propensity Score Matching

OBJECTIVES:The usefulness of non-magnifying endoscopy with narrow-band imaging (NBI; NM-NBI) in the screening of early esophageal squamous cell carcinoma (SCC) and high-grade intraepithelial neoplasia (HGIN) remains unclear. Here, we aimed to compare NM-NBI and chromoendoscopy with iodine staining (CE-Iodine) in terms of the diagnostic performance, and to evaluate the usefulness of NM-NBI in detecting early esophageal SCC.METHODS:We prospectively enrolled 202 consecutive patients (male/female=180/22; median age, 67 years) with high-risk factors for esophageal SCC. All patients received endoscopic examination with NM-NBI and CE-Iodine to screen for early esophageal SCC or HGIN. We conducted the examinations sequentially, and calculated the accuracy, sensitivity, and specificity through a per-lesion-based analysis. A propensity score matching analysis was performed to reduce the effects of selection bias, and we compared the respective outcomes according to NM-NBI and CE-Iodine after matching.RESULTS:The accuracy, sensitivity, and specificity of NM-NBI were 77.0, 88.3, and 75.2%, respectively, and those for unstained areas by CE-Iodine were 68.0, 94.2, and 64.0, respectively. The accuracy and specificity of NM-NBI were superior to those of CE-Iodine (P=0.03 and P=0.01, respectively). However, the sensitivity did not significantly differ between NM-NBI and CE-Iodine (P=0.67). The accuracy and specificity of NM-NBI before matching were superior to those of CE-Iodine after matching (P=0.04 and P=0.03).CONCLUSIONS:NM-NBI was useful and reliable for the diagnosis of esophageal SCC and can be a promising screening strategy for early esophageal SCC.

High Mobility Group Box 1 Promotes Small Intestinal Damage Induced by Nonsteroidal Anti-Inflammatory Drugs through Toll-Like Receptor 4

Release of high mobility group box 1 (HMGB1) from damaged cells, which is involved in many types of tissue injuries, activates inflammatory pathways by stimulating multiple receptors, including Toll-like receptor 2 (TLR2), TLR4, and receptor for advanced glycation end-products (RAGE). Our objective was to determine the role of HMGB1 in nonsteroidal anti-inflammatory drug (NSAID)-induced damage of the small intestine. Oral indomethacin (10 mg/kg) induced damage to the small intestine and was associated with increases in intestinal HMGB1 expression and serum HMGB1 levels. In wild-type mice, recombinant human HMGB1 aggravated indomethacin-induced small intestinal damage; enhanced the mRNA expression levels of tumor necrosis factor α (TNF-α), monocyte chemotactic protein 1, and KC; activated nuclear factor kappa B; and stimulated phosphorylation of the mitogen-activated protein kinases p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK). In contrast, blocking HMGB1 action with neutralizing antibodies prevented damage and inhibited both inflammatory cytokine overexpression and activation of these intracellular signaling pathways. TLR2-knockout (KO) and RAGE-KO mice exhibited high sensitivities to indomethacin-induced damage, similar to wild-type mice, whereas TLR4-KO mice exhibited less severe intestinal damage and lower levels of TNF-α mRNA expression. Exogenous HMGB1 aggravated the damage in TLR2- and RAGE-KO mice but did not affect the damage in TLR4-KO mice. Thus, our results suggest that HMGB1 promotes NSAID-induced small intestinal damage through TLR4-dependent signaling pathways.