Rintaro Narisawa

The efficacy of endoscopic triamcinolone injection for the prevention of esophageal stricture after endoscopic submucosal dissection.

BACKGROUND Use of endoscopic submucosal dissection (ESD) for management of widespread superficial esophageal carcinomas may be complicated by the development of severe strictures, which may require serial treatment with endoscopic balloon dilatation (EBD). OBJECTIVE The goal of this study was to determine the efficacy of endoscopic triamcinolone injection (ETI) for the prevention of stricture formation after ESD. DESIGN Case series. SETTING Tertiary-care referral center. PATIENTS A total of 41 consecutive patients who had a semi-circumferential mucosal defect that arose after ESD for superficial esophageal squamous cell carcinomas were enrolled in this study. INTERVENTIONS EBD and ETI. MAIN OUTCOME MEASUREMENTS Incidence of stricture and frequency of required EBD. RESULTS ETI was performed in one group of patients (study group, n = 21) but not in the other (control group, n = 20). The incidence of stricture was significantly lower in the study group (19.0%) than in the control group (75.0%; P < .001). The number of required EBDs was also lower in the study group (mean, 1.7; range, 0-15) than in the control group (mean, 6.6; range 0-20). There were no side effects or complications associated with ETI. LIMITATIONS Nonrandomized study design and small number of patients in a single endoscopic center. CONCLUSIONS This study suggests that ETI is safe and effective for the prevention of esophageal stricture in patients undergoing ESD for superficial esophageal squamous cell carcinomas.

Selective depletion of neutrophils by a monoclonal antibody, RP-3, suppresses dextran sulphate sodium-induced colitis in rats

Administration of dextran sulphate sodium to animals induces acute colitis characterized by infiltration of large numbers of neutrophils into the colonic mucosa, which histologically resembles human active ulcerative colitis. It has been reported that neutrophils and the reactive oxygen metabolites produced by them are involved in the progress of ulcerative colitis. This study was intended to clarify their roles by using this animal model. First, possible sources and species of reactive oxygen metabolites were determined using luminol‐dependent chemiluminescence with addition of enzyme inhibitors and reactive oxygen metabolite scavengers. Next, to examine whether neutrophils and hypochlorous acid derived from them contribute to tissue injury, we administered RP‐3, a monoclonal antibody capable of selectively depleting neutrophils, and taurine, a hypochlorous acid scavenger, to rats treated with dextran sulphate sodium. Addition of azide, taurine, catalase, superoxide dismutase and dimethyl sulphoxide into colonic mucosal scrapings significantly inhibited chemiluminescence production, but allopurinol and indomethacin had no effects. These results suggest that excessive hypochlorous acid, hydrogen peroxide, superoxide anion and hydroxyl radical are generated by the inflamed colonic mucosa. Intraperitoneal injections of RP‐3 significantly suppressed bleeding, tissue myeloperoxidase activity, chemiluminescence production and erosion formation. On the other hand, administration of taurine tended to inhibit bleeding and erosion formation to some extent, although it could not significantly suppress them. These data suggest that neutrophils play an important role in the development of this colitis and that hypochlorous acid might be one of the causes of tissue injury induced by neutrophils.

What is an appropriate indication for endoscopic papillary balloon dilation

Objective There are a number of views on the indication for endoscopic papillary balloon dilation (EPBD) in the management of bile duct stones. In this study, we have evaluated the efficacy and safety of EPBD compared with endoscopic sphincterotomy (EST). Design Prospective randomized trial. Setting One university hospital and one general hospital. Participants and main outcome measures One hundred and forty patients were randomly allocated to EPBD or EST. Outcomes and complications were observed for a median period of 30 months. Results Both treatment approaches finally achieved similar success rates and needed similar numbers of treatment sessions for patients with stones less than 10 mm in diameter. However, for patients with stones of 10 mm or more, EPBD required a significantly greater mean number of treatment sessions than EST (2.4 vs 1.6, P < 0.01). Early complications occurred in seven EPBD (four pancreatitis, two cholangitis and one basket impaction) and eight EST (three pancreatitis, two bleeding and three cholangitis) patients. Late complications occurred in four EPBD (three recurrent bile duct stones and one cholecystitis) and six EST (three recurrent stones and three cholecystitis) patients. Conclusions EPBD has little risk of bleeding. The technique removed small bile duct stones just as easily as did EST. These two procedures had approximately the same risk of pancreatitis and incidence of recurrent bile duct stones. Therefore, both procedures appear to be appropriate treatments for small bile duct stones. Whether or not EPBD becomes an established treatment will depend on further long-term studies.

Gastric carcinoid tumors without autoimmune gastritis in Japan: A relationship with Helicobacter pylori infection

In Japan, most cases of gastric carcinoid tumor (GCT) are unassociated with either autoimmune gastritis (AIG) showing type-A chronic atrophic gastritis (CAG-A) or Zollinger-Ellison syndrome (ZES). However, the pathogenesis of this tumor remains unknown. Recent studies have determined that Helicobacter pylori infection induces gastric carcinoid in Mongolian gerbils and that H. pylori lipopolysaccharide exerts a mitogenic effect on ECL cells. We examined five patients with histologically diagnosed GCT, 40 patients with H. pylori-positive gastric ulcer (Hp+GU), 24 patients with H. pylori-positive duodenal ulcer (Hp+DU), and 12 patients with AIG showing CAG-A topographically. We compared the prevalence of H. pylori infection, and the levels of gastrin and pepsinogen (PG) in the serum of patients with GCT with those of patients with Hp+GU, or Hp+DU, and AIG. We also investigated the histological characteristics of the tumor and the gastric corpus mucosa in the GCT patients. The levels of serum gastrin and PG I and II were measured using an RIA kit. In all five (100%) patients with GCT, H. pylori infection was present, without any evidence of AIG or ZES. The serum levels of gastrin in the GCT patients were higher than those in either Hp+GU or Hp+DU patients and lower than those in the AIG patients. In contrast, serum PG I levels and the PG I/II ratio were lower in the GCT group than in the Hp+GU or Hp+DU groups. Histologically, all GCTs were ECL cell tumors and peritumoral corporal mucosal atrophy was observed in four of the five patients with GCT. In conclusions, H. pylori infection and hypergastrinemia were found in the patients with GCT without AIG. This finding suggests that H. pylori infection may induce corporal mucosal atrophy and hypergastrinemia that can produce a GCT with time.

SELF-LIMITING RISK OF METACHRONOUS GASTRIC CANCERS AFTER ENDOSCOPIC RESECTION

Background:  Since endoscopic resection (ER) has been established as a treatment for early gastric cancer, metachronous multiple cancers have become a problem. It is unclear whether the risk of metachronous cancer is self‐limiting or permanent. The aim of this study was to evaluate the incidence of multiple cancers after ER during a long‐term follow‐up study.

Collagenous Gastritis: Endoscopic and Pathologic Evaluation of the Nodularity of Gastric Mucosa

Collagenous gastritis is a rare disorder, with 20 cases reported in the English literature to date [1–15]; the pathogenesis and prognosis remain unknown. Collagenous gastritis is defined histologically by the presence of a subepithelial collagen band thicker than 10 μm in association with increased inflammatory cell infiltrate of the lamina propria [9] and it is therefore straightforward to make a histological diagnosis from a biopsy specimen. While mucosal nodularity of the stomach is a characteristic finding, observed in 8 [1, 6, 7, 12–15] of the previous 20 cases, the endoscopic

Capnographic Monitoring during Endoscopic Submucosal Dissection with Patients under Deep Sedation: A Prospective, Crossover Trial of Air and Carbon Dioxide Insufflations

Background and Aims: The safety of carbon dioxide (CO₂) insufflation has not been fully established for esophageal and gastric endoscopic submucosal dissection (ESD) under deep sedation, because CO₂ retention is not only caused by CO₂ insufflation but also by the sedation level and the patient’s respiratory status. To clarify the clinical safety of CO₂ insufflation, we conducted a crossover trial of air and CO₂ insufflations. Methods: A total of 60 patients with early esophageal or gastric cancers underwent ESD during which insufflation was switched from CO₂ to air or from air to CO₂; transcutaneous partial pressure CO₂ (PtcCO₂) was monitored in all patients. We also assessed respiratory function, arterial blood gas analysis, and smoking history. Results: Although significant increases in PtcCO₂ from baseline were observed, there were no significant differences in PtcCO₂ levels during CO₂ insufflation compared with levels during air insufflation in groups that received CO₂ preceding air or air preceding CO₂. All patients underwent ESD safely without adverse events, including 20 patients with subclinical respiratory dysfunction. The sedation protocol was the only significant predictor of CO₂ retention, independent of CO₂ insufflation. Conclusions: CO₂ insufflation can be used as safely as air insufflation during ESD under deep sedation.

Activated CD4+ and CDS+ Cells in the Colonic Mucosa of Ulcerative Colitis Patients: Their Relationship to HLA-DR Antigen Expression on the Colonic Epithelium and Serum Soluble CD25 Levels

This study was performed to clarify the relationship between activated (HLA-DR-expressing) CD4+ and CD8+ cells in the colonic lamina propria of ulcerative colitis and other immunological factors, i.e., epithelial DR expression, serum soluble CD25 levels, and colonic mucosal CD25+ cells. The frequency of epithelial DR expression was positively correlated with the numbers of CD4+ and CD8+ cells. The percentages activated CD4+/CD4+ cells were higher in mucosae with DR- epithelium than in mucosae with DR+ epithelium. The serum soluble CD25 levels were increased in ulcerative colitis, and there was an inverse correlation between these levels and the relative number of activated CD4+ cells in untreated active disease. These results suggest that interactions among mucosal CD4+ cells, colonic epithelium, and serum soluble CD25 might play an important role in the pathogenesis of ulcerative colitis.

The Relationship Between Iron Deficiency in Patients with Helicobacter Pylori‐Infected Nodular Gastritis and the Serum Prohepcidin Level

Helicobacter pylori (H. pylori) is recognized as a causative agent for unexplained iron‐deficiency anemia (IDA). We evaluated many background factors influencing an iron‐deficiency state in adult patients with various H. pylori‐infected upper gastrointestinal tract diseases.

Regional Differences on Production of Chemokines in Gastric Mucosa Between Helicobacter pylori-Positive Duodenal Ulcer and Gastric Ulcer

It is well known that antrum-predominantgastritis and pan-gastritis occurs in the patients withHelicobacter pylori-positive duodenal ulcer (DU) andgastric ulcer (GU), respectively. However, the role of chemokines in the pathogenesis of thesepathologies is unclear. We examined the regionaldifferences in mucosal chemokine production in patientswith DU and GU. The production of interleukin-8 (IL-8), growth-related gene (GRO) α, andmacrophage inflammatory protein (MIP)-1α wasgreater in the antrum than in the corpus in DU patients.In the patients with GU, monocyte chemoattractantprotein (MCP)-1 levels in the mucosa adjacent to ulcer weregreater than those away for the ulcer in the corpus. Thereduction in chemokine production occurring inassociation with the eradication of H. pylori differed between DU and GU patients in the antrum (IL-8,P = 0.0394; GROα, P = 0.0149; MIP-1α, P =0.0246; MCP-1, P = 0.0087). The data imply a differentpathogenesis may exist for the gastritis present in patients with DU and GU occurring in H.pylori-positive individuals.