Kyosuke Tanaka

Ease of early gastric cancer demarcation recognition: A comparison of four magnifying endoscopy methods

Background and Aim:  Various techniques using magnifying endoscopy (ME) have been developed to enhance images of early gastric cancer (EGC) demarcations, which are often obscure. We investigated four ME methods to determine which is most effective in enhancing the recognition of EGC demarcations: conventional ME (CME), ME with narrow band imaging (NBI‐ME), enhanced‐magnification endoscopy with acetic acid (EME), and ME with NBI and acetic acid (NBI‐EME).

Features of early gastric cancer and gastric adenoma by enhanced-magnification endoscopy

BackgroundChanges to the mucosal surface of early gastric carcinomas and gastric adenomas as viewed by enhanced-magnification endoscopy with acetic acid have not been investigated thoroughly. Using this technology, we investigated the appearance of the gastric surface patterns of neoplastic and surrounding nonneoplastic mucosa.MethodsForty-seven consecutive patients with early gastric carcinomas or gastric adenomas underwent enhanced-magnification endoscopy following 1.5% acetic acid instillation. All biopsy specimens were taken from the area at which the enhanced-magnified endoscopic image was obtained.ResultsSurface patterns of gastric tumors and the surrounding mucosa were classified into five types: type I, small round pits of uniform size and shape; type II, slit-like pits; type III, gyrus and villous patterns; type IV, irregular arrangements and sizes of pattern types I, II and III; type V, destructive patterns of types I, II and III. The predominant pattern of the surrounding mucosa was type III, and most type III mucosa had characteristics of intestinal metaplasia. Although all elevated adenomas showed type II or type III surface patterns, both depressed adenomas showed type IV. Elevated carcinomas showed type III (42.9%) or type IV (57.1%) surface patterns, while depressed carcinomas showed type IV (70%) or type V (30%). Although differentiated tubular adenocarcinomas showed type III (10.3%), type IV (86.2%), or type V (3.5%) surface patterns, all of the signet-ring cell carcinomas and poorly differentiated tubular adenocarcinomas showed type V.ConclusionsEnhanced-magnification endoscopy may be useful for identifying gastric tumors and determining the extent of horizontal spread, especially in tumors of the depressed type.

Surface pattern classification by enhanced-magnification endoscopy for identifying early gastric cancers

BACKGROUND The correlation between fine surface patterns of gastric mucosal lesions and early gastric cancer is not sufficiently clear. OBJECTIVE To evaluate the efficacy of surface pattern classification by enhanced-magnification endoscopy (EME) for identifying early gastric cancers. DESIGN Observational study. SETTING All procedures were performed at Mie University Hospital. PATIENTS A total of 380 consecutive patients who underwent EGD by using magnification endoscopy. Among these subjects were found 250 newly detected lesions suspected of being gastric cancer. METHODS Conventional magnification endoscopy (CME), magnification chromoendoscopy (MCE), and EME were performed, and surface patterns of lesions were classified into 5 types: type I, small round pits of uniform size and shape; type II, slit-like pits; type III, gyrus and villous patterns; type IV, irregular arrangement and size; and type V, destructive pattern. Biopsy specimens were obtained from all lesions. MAIN OUTCOME MEASUREMENTS Correlation between surface pattern classification by EME and histopathologic findings of early gastric cancer. RESULTS Surface patterns were evident by CME/MCE in only 66.4% (166/250) of lesions but in 100% (250/250) of lesions by EME. Classification by EME was as follows: type I, 52 lesions; type II, 12; type III, 146; type IV, 32; and type V, 8. By histopathologic examination, 16 early gastric cancers were detected between type IV or V lesions. Thus, classification of types IV-V strongly correlated with the presence of gastric cancer (sensitivity 100%, specificity 89.7%). LIMITATIONS Single-center study. CONCLUSIONS Surface pattern classification by EME may be useful for identifying early gastric cancers.

Reactive nitrogen species mediate DNA damage in Helicobacter pylori-infected gastric mucosa.

Background:  Reactive oxygen species (ROS) and reactive nitrogen species (RNS) can play an important role in cellular injury and carcinogenesis of gastric epithelial cells infected with Helicobacter pylori. 8‐OH‐deoxy guanosine (8‐OHdG) and 8‐nitroguanine (8‐NG) are markers for ROS‐ and RNS‐mediated DNA oxidation, respectively. In this study, RNS‐mediated DNA damage in gastric mucosa was observed directly using a newly developed antibody to 8‐NG to clarify how H. pylori infection causes nitrative DNA damage to gastric epithelial cells.

Narrow-band imaging magnifying endoscopy in adult patients with eosinophilic esophagitis/esophageal eosinophilia and lymphocytic esophagitis

13 Eosinophilic esophagitis (EoE), a chronic inflammatory condition characterized by esophageal dysfunction and eosinophilic infiltrate in the esophageal epithelium, was first described by Landres et al in 1978. More recently, Rubio et al described lymphocytic esophagitis (LyE) as an independent entity portraying high numbers of infiltrating CD3, CD4, and CD8 expressing intraepithelial lymphocytes. Patients with EoE and LyE usually complained of dysphagia and food impaction. There are a number of reports concerning conventional endoscopic features in EoE but few on LyE. In these reports, the endoscopic features include esophageal rings, linear furrows, whitish exudates, narrow lumen, or stenosis. Nevertheless, none of these can be considered pathognomonic for EoE or LyE because similar endoscopic features have been described in other esophageal disorders. When white-light-based conventional endoscopy was used, the esophagus appears to be normal in approximately 7% to 32% of cases of EoE and in 23% to 55% of those with LyE. In 1 study, narrow-band imaging (NBI)withoutmagnification did not improve the ability to recognize EoE. Magnifying endoscopy enables visualization of capillary vessels (intrapapillary capillary loop [IPCL]) in the esophageal mucosa. Despite magnifying endoscopy combined with NBI (NBI-ME) being widely used to detect early GI

Interleukin-17 Induces an Atypical M2-Like Macrophage Subpopulation That Regulates Intestinal Inflammation

Interleukin 17 (IL-17) is a pleiotropic cytokine that acts on both immune and non-immune cells and is generally implicated in inflammatory and autoimmune diseases. Although IL-17 as well as their source, mainly but not limited to Th17 cells, is also abundant in the inflamed intestine, the role of IL-17 in inflammatory bowel disease remains controversial. In the present study, by using IL-17 knockout (KO) mice, we investigated the role of IL-17 in colitis, with special focus on the macrophage subpopulations. Here we show that IL-17KO mice had increased susceptibility to DSS-induced colitis which was associated with decrease in expression of mRNAs implicated in M2 and/or wound healing macrophages, such as IL-10, IL-1 receptor antagonist, arginase 1, cyclooxygenase 2, and indoleamine 2,3-dioxygenase. Lamina propria leukocytes from inflamed colon of IL-17KO mice contained fewer CD11b+Ly6C+MHC Class II+ macrophages, which were derived, at least partly, from blood monocytes, as compared to those of WT mice. FACS-purified CD11b+ cells from WT mice, which were more abundant in Ly6C+MHC Class II+ cells, expressed increased levels of genes associated M2/wound healing macrophages and also M1/proinflammatory macrophages. Depletion of this population by topical administration of clodronate-liposome in the colon of WT mice resulted in the exacerbation of colitis. These results demonstrate that IL-17 confers protection against the development of severe colitis through the induction of an atypical M2-like macrophage subpopulation. Our findings reveal a previously unappreciated mechanism by which IL-17 exerts a protective function in colitis.

Human Equilibrative Nucleoside Transporter 1 Expression in Endoscopic Ultrasonography-Guided Fine-Needle Aspiration Biopsy Samples Is a Strong Predictor of Clinical Response and Survival in the Patients With Pancreatic Ductal Adenocarcinoma Undergoing Gemcitabine-Based Chemoradiotherapy.

ObjectivesThis study aimed to clarify whether pretreatment human equilibrative nucleoside transporter (hENT1) expressions in endoscopic ultrasonography-guided fine-needle aspiration biopsy (EUS-FNAB) specimens obtained from resectable, borderline resectable, and locally advanced unresectable pancreatic ductal adenocarcinoma (PDAC) are concordant with those in the resected specimen after gemcitabine-based chemoradiotherapy (Gem-CRT) and to validate the utility of hENT1 expression using EUS-FNAB samples as a prognostic marker. MethodsWe evaluated the relationship between hENT1 expressions assessed by immunohistochemical staining and clinical outcomes in 51 of 76 patients with PDAC who were diagnosed by EUS-FNAB and received preoperative Gem-CRT. ResultsThe concordance rate of hENT1 expressions was 89.2% (K = 0.681). Median survival time (month) in the 51 whole patients and 37 patients with resection was significantly longer in hENT1 positive than in hENT1 negative: 25.0 and 30.0 versus 9.0 and 9.0, respectively. A multivariate analysis confirmed that hENT1 expression was an independent prognostic factor in both whole patients and those with resection. Regardless of T3 and T4, hENT1-positive patients with resection had significantly better prognosis than hENT1-negative patients, whose prognosis was similar to those without resection. ConclusionsThe assessment of hENT1 expression using EUS-FNAB samples before Gem-CRT provides important information on patients with PDAC who can benefit from curative-intent resection.

MAGNIFICATION ENDOSCOPIC VIEW OF AN EARLY GASTRIC CANCER USING ACETIC ACID AND NARROW-BAND IMAGING SYSTEM

A 62‐year‐old woman was referred to Mie University Hospital, Tsu, Japan, for examination of upper gastrointestinal tract. The conventional endoscopy showed a slightly depressed lesion on the greater curvature at the gastric body. The surface of surrounding non‐neoplastic mucosa using magnification endoscopy with acetic acid was gyrus‐villous pattern whereas the surface of the lesion was rough. Furthermore, magnification endoscopy using acetic acid and narrow‐band imaging system visualized clearer fine surface pattern of carcinoma. The lesion had a rough mucosa with irregularly arranged small pits. The lesion was resected completely by endoscopic mucosal resection with insulated‐tip electrosurgical knife. Narrow‐band imaging system with acetic acid may be able to visualize not only the capillary pattern but also the fine surface pattern of gastric carcinoma.

Second and Third-look Endoscopy for the Prevention of Post-ESD Bleeding

AbstractThe efficacy of 2nd-look esophagogastroduodenoscopy (EGD) with endoscopic hemostatic therapy (EHT) for the prevention of postendoscopic submucosal dissection (ESD) clinical bleeding remains controversial. The aim of this study was to estimate post-ESD bleeding rate using 2nd and 3rd-look strategy, and to determine risk factors for clinical bleeding, and for EHT at 2nd and 3rd-look EGDs.Three hundred forty-four consecutive patients with early gastric cancer or adenoma underwent ESD from January 2006 through March 2012. Second and 3rd-look EGDs were performed on day 1 (D1) and day 7 (D7), respectively, with EHT as needed.Post-ESD clinical bleeding rate was 2.6% (95% confidence interval [CI] 1.2%–4.9%). For clinical bleeding, adjusted odds ratios (ORs) for age <65 years and antithrombotic drug uses were 4.40 (95% CI 1.07–19.93) and 7.34 (95% CI 1.80–32.48), respectively. For D1 EHT, adjusted ORs of tumor location in the lower part of the stomach and maximum tumor diameter ≥60 mm were 2.16 (95% CI 1.35–3.51) and 2.20 (95% CI 1.05–4.98), respectively. For D7 EHT, adjusted OR of D1 EHT was 4.65 (95% CI 1.56–20.0).Post-ESD clinical bleeding rate was relatively low using 2nd and 3rd-look strategy. Age <65 years and antithrombotic drug use are significant risk factors for clinical bleeding. Regarding EHT, tumor location in the lower part of the stomach and maximum diameter of resected specimen ≥60 mm are significant predictors for D1 EHT. D1 EHT in turn is a significant risk factor for D7 EHT. The efficacy of sequential strategy for preventing post-ESD bleeding is promising.

Single-incision laparoscopic and endoscopic cooperative surgery for gastrointestinal stromal tumor arising from the duodenum.

We report a case involving a minimally invasive single‐incision laparoscopic and endoscopic cooperative local excision of a duodenal gastrointestinal stromal tumor. A 59‐year‐old man presented with a 35‐mm lesion located in the second portion of the duodenum. A local resection was performed via single‐incision laparoscopic and endoscopic cooperative surgery. Intraluminal endoscopic dissection of the duodenal mucosa and submucosa was performed circumferentially around the tumor. The resection was then completed by laparoscopic dissection of the seromuscular layer around the tumor. The tumor was retrieved laparoscopically. After confirming that the resection achieved clear surgical margins, we closed the duodenal wall with a laparoscopic stapling device. There were no postoperative complications, including stenosis. Single‐incision laparoscopic and endoscopic cooperative surgery can be safely and effectively performed for a duodenal submucosal tumor.