Naoki Ohmiya

Clinical usefulness of novel tag-less Agile patency capsule prior to capsule endoscopy for patients with suspected small bowel stenosis

The Agile patency capsule (PC; Given Imaging Ltd, Yoqneam, Israel) is used as a dummy prior to capsule endoscopy (CE) to avoid retention of the CE capsule. However, impaction of the PCs inner radio frequency identification (RFID) tag in a stricture could cause small‐bowel ileus. Recently, the RFID tag‐less PC was introduced into clinical practice. Herein, we aimed to retrospectively evaluate the usefulness of the tag‐less PC.

Risk factors of symptomatic NSAID-induced small intestinal injury and diaphragm disease

The aetiology for nonsteroidal anti‐inflammatory drug (NSAID)‐induced small intestinal injuries has not been well characterised.

Usefulness of flexible spectral imaging color enhancement (FICE) for the detection of angiodysplasia in the preview of capsule endoscopy.

BACKGROUNDS/AIMS Flexible spectral imaging color enhancement (FICE) is an image enhancement system that can obtain bright and high-contrast images. FICE for capsule endoscopy (CE) is available during interpretation of Given Imaging, but its usefulness is rarely reported. The aim of this study is to evaluate the preview of angiodysplasia by FICE in comparison with the conventional preview. METHODOLOGY The accumulated CE data of 50 patients with angiodysplasia were randomly assigned to 2 equally sized groups of conventional reading and FICE reading. One experienced doctor analyzed them for the first time in a quick-view mode and the mean reading time, sensitivity and specificity for detecting angiodysplasia by each method were evaluated for comparisons including suspected blood indicator. RESULTS The mean reading time was 14min for both conventional reading and FICE reading. The two previews of angiodysplasia were significantly superior to the function of suspected blood indicator (p<0.01). The sensitivity and specificity of conventional reading for detecting angiodysplasia were 80% and 100%, respectively. Those of FICE reading were 91% and 86%, respectively. FICE reading was superior in term of sensitivity, while it resulted in more false positive lesion findings and lower specificity. However, such false-positive findings by FICE reading can be correctly identified at a glance by converting the image to conventional mode. CONCLUSIONS This study demonstrates that FICE enables accurate detection of angiodysplasia in the preview of CE.

Obscure gastrointestinal bleeding: Diagnosis and treatment

Small‐bowel bleeding comprises a majority of obscure gastrointestinal bleeding, but is caused by various kinds of diseases. For its diagnosis, history‐taking and physical examination is requisite, leading to a suspicion of what diseases are involved. Next, cross‐sectional imaging such as computed tomography should be done, followed by the latest enteroscopy, videocapsule endoscopy and deep enteroscopy according to the severity of hemorrhage and patient conditions. After comprehensive diagnosis, medical, enteroscopic, or surgical treatment should be selected.

Double-balloon endoscopy is safe and effective for the diagnosis and treatment of small-bowel disorders: Prospective multicenter study carried out by expert and non-expert endoscopists in Japan

Double‐balloon endoscopy (DBE) has enabled direct, detailed examination of the entire small bowel with interventional capabilities. Although its usefulness is recognized, efficacy and safety have not been extensively evaluated by prospective multicenter studies. To evaluate the efficacy and safety of DBE carried out by expert and non‐expert endoscopists, a prospective, multicenter study was conducted in five university hospitals and a general hospital in Japan.

DNA Methylation Status of Epithelial-Mesenchymal Transition (EMT) - Related Genes Is Associated with Severe Clinical Phenotypes in Ulcerative Colitis (UC)

Background Epithelial-to-mesenchymal transition (EMT) is a phenomenon that allows the conversion of adherent epithelial cells to a mesenchymal cell phenotype, which enhances migratory capacity and invasiveness. Recent studies have suggested that EMT contributes to the pathogenesis of ulcerative colitis (UC). We investigated the promoter DNA methylation status of EMT-related genes in the colonic mucosa in UC. Methods Colonic biopsies were obtained from the rectal inflammatory mucosa of 86 UC patients and the non-inflammatory proximal colonic mucosa of 10 paired patients. Bisulfite pyrosequencing was used to quantify the methylation of 5 candidate CpG island promoters (NEUROG1, CDX1, miR-1247, CDH1, and CDH13) and LINE1. Results Using an unsupervised hierarchical clustering analysis, inflamed rectal mucosa was well separated from mucosa that appeared normal. The CDH1 and CDH13 promoters were significantly associated with patient age (p = 0.04, 0.03, respectively). A similar trend was found between those genes and the duration of disease (CDH1: p = 0.07, CDH13: p = 0.0002, mean of both: p<0.00001). Several positive associations were found between hypermethylation and severe clinical phenotypes (CDX1 and miR-1247 and a refractory phenotype: p = 0.04 and 0.006, respectively. miR-1247 and CDH1 hyper methylation and a more severe Mayo endoscopic subscore: miR-1247: p = 0.0008, CDH1: p = 0.03, mean of both: p = 0.003). When the severe clinical phenotype was defined as having any of five phenotypes (hospitalized more than twice, highest Mayo endoscopic subscore, steroid dependence, refractory, or a history of surgery) miR-1247 hypermethylation was associated with the same phenotype (p = 0.008). Conclusions Our data suggest that variability in the methylation status of EMT-related genes is associated with more severe clinical phenotypes in UC.

Mutation spectrum of TP53 gene predicts clinicopathological features and survival of gastric cancer

Background and aim TP53 gene is frequently mutated in gastric cancer (GC), but the relationship with clinicopathological features and prognosis is conflicting. Here, we screened TP53 mutation spectrum of 214 GC patients in relation to their clinicopathological features and prognosis. Results TP53 nonsilent mutations were detected in 80 cases (37.4%), being frequently occurred as C:G to T:A single nucleotide transitions at 5′-CpG-3′ sites. TP53 mutations occurred more frequently in differentiated histologic type than in undifferentiated type in the early stage (48.6% vs. 7%, P=0.0006), while the mutations correlated with venous invasion among advanced stage (47.7% vs. 20.7%, P=0.04). Subset of GC with TP53 hot spot mutations (R175, G245, R248, R273, R282) presented significantly worse overall survival and recurrence free survival compared to others (both P=0.001). Methods Matched biopsies from GC and adjacent tissues from 214 patients were used for the experiment. All coding regions of TP53 gene (exon2 to exon11) were examined using Sanger sequencing. Conclusion Our data suggest that GC with TP53 mutations seems to develop as differentiated histologic type and show aggressive biological behavior such as venous invasion. Moreover, our data emphasizes the importance of discriminating TP53 hot spot mutations (R175, G245, R248, R273, R282) to predict worse overall survival and recurrence free survival of GC patients.

Change in DNA methylation patterns of SLC6A4 gene in the gastric mucosa in functional dyspepsia.

Background The neurochemical serotonin (5-HT) is an important signaling molecule in the gastrointestinal motor and sensory functions. A key regulator of 5-HT levels is the transmembrane serotonin transporter (5-HTT; SLC6A4) that governs the reuptake of 5-HT. Recent studies have indicated 5-HTT expression may be regulated by epigenetic mechanisms. We investigated DNA methylation status of SLC6A4 gene in the gastric mucosa from functional dyspepsia (FD) because of their potential role in dyspeptic symptoms. Methods Endoscopic gastric biopsies were obtained from 78 subjects with no upper abdominal symptoms and 79 patients with FD. Bisulfite Pyrosequencing was carried out to determine the methylation status of promoter CpG islands (PCGIs), promoter non-CpG islands (PNCGIs) and gene body non-CpG islands (NPNCGIs) in the SLC6A4 gene. Gene expression was examined by real-time PCR. Results In overall, methylation level of PCGIs was significantly lower in FD compared to control subjects (p = 0.04). On the other hand, methylation level of NPNCGIs was significantly higher in FD compared to control subjects (p = 0.03). Lower methylation level in PNCGIs was highlighted in the patients with PDS (p = 0.01), while higher methylation level in NPNCGIs was more prominent in the patients with EPS (p = 0.017). Methylation levels of PCGIs and PNCGIs were inversely correlated, while methylation levels of NPNCGIs was positively correlated with SLC6A4 mRNA levels in FD patients. Conclusions Our data suggest that change in DNA methylation pattern of SLC6A4 in the gastric mucosa may have a role for developing FD. A role of epigenetics for developing FD needs to be further evaluated.

Preliminary study on evaluation of the pancreatic tail observable limit of transabdominal ultrasonography using a position sensor and CT-fusion image

BACKGROUND AND AIM Transabdominal ultrasonography (US) is commonly used for the initial screening of bilio-pancreatic diseases in Asian countries due to its widespread availability, the non-invasiveness and the cost-effectiveness. However, it is considered that US has limits to observe the area, namely the blind area. The observation of the pancreatic tail is particularly difficult. The goal of this study was to examine the pancreatic tail region that cannot be visualized on transverse scanning of the upper abdomen using US with spatial positional information and factors related to visualization, and observation of the tail from the splenic hilum. METHODS Thirty-nine patients with pancreatic/biliary tract disease underwent CT and US with GPS-like technology and fusion imaging for measurement of the real pancreatic length and the predicted/real unobservable (PU and RU) length of the pancreatic tail. RU from US on transverse scanning and the real pancreatic length were used to determine the unobservable area (UA: RU/the real pancreatic length). Relationships of RU with physical and hematological variables that might influence visualization of the pancreatic tail were investigated. RESULTS The real pancreatic length was 160.9 ± 16.4mm, RU was 41.0 ± 17.8mm, and UA was 25.3 ± 10.4%. RU was correlated with BMI (R=0.446, P=0.004) and waist circumferences (R=0.354, P=0.027), and strongly correlated with PU (R=0.788, P<0.001). The pancreatic tail was visible from the splenic hilum in 22 (56%) subjects and was completely identified in 13 (33%) subjects. CONCLUSIONS Combined GPS-like technology with fusion imaging was useful for the objective estimation of the pancreatic blind area.

Management of small-bowel polyps at double-balloon enteroscopy.

Small bowel tumors (SBTs) are uncommon, insidious in presentation, and frequently represent a diagnostic challenge. The advent of video capsule endoscopy (VCE) and double-balloon endoscopy (DBE) is a significant breakthrough for visual diagnosis of SBTs throughout the small bowel. Contrast-enhanced computed tomography (CECT) and fluoroscopic enteroclysis had significantly lower diagnostic yields of tumors that were 10 mm or smaller in diameter, but VCE and DBE had high diagnostic yields regardless of tumor size. Regarding SBTs larger than 10 mm in diameter, CECT had a significantly lower diagnostic yield of epithelial tumors compared to subepithelial tumors, whereas fluoroscopic enteroclysis and DBE had high diagnostic yields regardless of the tumor type. VCE had a slightly lower diagnostic yield of subepithelial tumors (78%) compared to epithelial tumors. Therefore, a combined examination method by using CECT and VCE is useful for screening of SBTs. In case suspicious of stenosis, patency capsule should be performed to confirm passage before VCE. DBE is useful for further precise examination including biopsy and ultrasonography by using miniature probe, and enteroscopic treatment. After medical, enteroscopic, and surgical treatment, VCE is helpful for follow-up. DBE is safe and useful in resecting the SBTs deep within the small bowel without laparotomy. Indications of enteroscopic resection may be benign tumors regardless of epithelial or subepithelial type, localizing in the mucosal or submucosal layer, which are symptomatic at present or possibly symptomatic or transforming in the future. Malignant tumors localized in the mucosal layer may be indications although detecting at an early stage is challenging. In this review article, we describe management of SBTs/polyps by various modalities.