Magnifying narrow-band imaging (M-NBI) is useful for the accurate diagnosis of early gastric cancer (EGC). However, acquiring skill at M-NBI diagnosis takes substantial effort. An Internet-based e-learning system to teach endoscopic diagnosis of EGC using M-NBI has been developed. This study evaluated its effectiveness. This study was designed as a multicenter randomized controlled trial. We recruited endoscopists as participants from all over Japan. After completing Test 1, which consisted of M-NBI images of 40 gastric lesions, participants were randomly assigned to the e-learning or non-e-learning groups. Only the e-learning group was allowed to access the e-learning system. After the e-learning period, both groups received Test 2. The analysis set was participants who scored< 80 % accuracy on Test 1. The primary end point was the difference in accuracy between Test 1 and Test 2 for the two groups. A total of 395 participants from 77 institutions completed Test 1 (198 in the e-learning group and 197 in the non-e-learning group). After the e-learning period, all 395 completed Test 2. The analysis sets were e-learning group: n = 184; and non-e-learning group: n = 184. The mean Test 1 score was 59.9 % for the e-learning group and 61.7 % for the non-e-learning group. The change in accuracy in Test 2 was significantly higher in the e-learning group than in the non-e-learning group (7.4 points vs. 0.14 points, respectively; < 0.001). This study clearly demonstrated the efficacy of the e-learning system in improving practitioners' capabilities to diagnose EGC using M-NBI.Trial registered at University Hospital Medical Information Network Clinical Trials Registry (UMIN000008569).
Abstract. Sessile serrated adenoma (SSA) is a proposed precursor of colorectal carcinogenesis. This study aimed to analyze the potential of endoscopy to discriminate SSA from other serrated lesions, specifically traditional serrated adenoma (TSA) and hyperplastic polyp (HP). Of 145 serrated lesions, 111 sessile serrated lesions including 32 TSAs, 25 SSAs and 54 HPs were analyzed for size, color, location and morphologic features using conventional endoscopy and magnifying chromoendoscopy. SSA was preferentially located in the right colon, whereas TSA and HP were located in the left colon. The sizes of SSA and TSA were larger than those of HP. The lesion color was indistinguishable among TSA, SSA and HP. Macroscopically, a pinecone-like or twotier raised appearance were found more frequently in TSA than in SAA and HP. Under magnified chromoendoscopic observation, the stellar III L pit pattern and fern-like appearance were observed more frequently in TSA than in SAA and HP. In conclusion, endoscopic discrimination between SSA and other sessile serrated lesions based on morphological features was difficult. However, size and location of the lesions facilitated diagnosis. IntroductionSerrated polyps of the colorectum have been the focus of critical reappraisal and intense study in recent years. Previously, the majority of serrated, non-adenomatous polyps were diagnosed as hyperplastic polyps (HPs) and treated as innocuous, benign lesions (1). Subsequently, HP was implicated in the development of colorectal cancer through a putative HP-serrated adenoma-colorectal cancer sequence. At present, the serrated polyps are regarded as heterogeneous lesions with several histological subtypes, including HP, traditional serrated adenoma (TSA) and sessile serrated adenoma (SSA) (2,3).Mounting evidence shows that SSA may be the precursor lesion through the previously described 'serrated pathway' of colorectal carcinogenesis (4), and some investigators recommend that SSA should be clinically managed in a similar manner to conventional adenomas (5). A greater frequency of microsatellite instability has been shown in SSA versus HP or TSA (6). SSA shows a higher frequency of CpG island methylation than conventional HP (7), while showing a higher frequency of BRAF gene mutations and a lower frequency of K-ras gene mutations versus conventional adenoma (8,9). Thus, reliable identification of SSA and its differentiation from other serrated lesions, such as HP and TSA, has important clinical implications and may condition therapeutic attitudes and endoscopic follow-up.Colonoscopy is the only technique currently available that offers the potential to detect and remove colorectal lesions throughout the large intestine. Some authors previously reported the endoscopic features of TSA and HP (10-13). However, the endoscopic features of SSA have yet to be established. This study aimed to compare the endoscopic features of the three sessile serrated lesions, TSA, SSA and HP, and to determine whether SSA can be distinguished from other serrated ...
Abstract.A newly developed autofluorescence (AF) imaging technique was applied during colonoscopy in a clinical setting. This pilot study was conducted to evaluate the clinical feasibility of applying AF endoscopy for distinguishing colorectal lesions. A total of 54 colorectal mucosal lesions obtained from 43 patients who underwent both white-light and AF endoscopy and were treated by endoscopy or surgery were assessed. Of the lesions, 11 were hyperplastic polyps, 30 were adenomas and 13 were carcinomas. To quantify the AF intensity, a color-contrast index (CCI) was determined and evaluated in relation to the histology, size and shape of each lesion. CCI was significantly associated with the histology and size of the lesions, but not their shape. CCI increased as the malignant potential increased (in the order of hyperplastic polyps → adenomas → carcinomas), irrespective of the lesion size (r=0.797, p<0.0001 for size >8 mm; r=0.622, p=0.0045 for size >8 mm but >15 mm; r=0.644, p=0.0071 for size >15 mm). In each size group, CCI tended to be higher for carcinomas than for adenomas, and also higher for adenomas than for hyperplastic polyps. CCI allowed discrimination of adenomas/carcinomas from hyperplastic polyps with 95.3% sensitivity and 63.6% specificity (cut-off value, 14.5), and of colorectal carcinomas from adenomas with 84.6% sensitivity and 80.0% specificity (cut-off value, 28.0). These results suggest that the quantitative analysis of AF intensity using CCI is helpful to discriminate among different types of colorectal mucosal lesions, including carcinomas.
Abstract:Endothelin-1 (ET-1) localization in dental and skeletal tissues was examined immunocytochemically using a biotin-streptoavidin-horseradish peroxidase method in paraffin sections. Mouse anti-ET-1 monoclonal antibody was used as the primary antibody. In teeth and periodontal tissues, intense immunostaining was observable mainly in periodontal ligament cells, i.e. fibroblasts, osteoblasts, osteoclasts, and vascular endothelial cells. Dental pulp, dentine, cementum, bone matrix, and gingival connective tissues were nonimmunoreactive.In the gingival epithelium, cells in the basal, prickle, and glanular layers stained intensely, whereas those of the keratinized layer were devoid of immunostaining.In metaphyseal bone marrow, intense immunostaining was observed over osteoclasts, osteoblasts, young osteocytes, and vascular endothelial cells. Bone and cartilage matrices, as well as chondrocytes in resting and proliferating zones, were, however, negative for immunoreaction.These results indicate that ET-1 is present in the cells of dental, periodontal, and bone tissues. Its wide distribution may reflect its involvement in various cellular functions in these tissues.
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