Advancements in the Diagnosis of Gastric Subepithelial Tumors

Goto Osamu,Kaise Mitsuru,Iwakiri Katsuhiko 거트앤리버 소화기연관학회협의회 2022 Gut and Liver Vol.16 No.3

A diagnosis of subepithelial tumors (SETs) is sometimes difficult due to the existence of overlying mucosa on the lesions, which hampers optical diagnosis by conventional endoscopy and tissue sampling with standard biopsy forceps. Imaging modalities, by using computed tomography and endoscopic ultrasonography (EUS) are mandatory to noninvasively collect the target’s information and to opt candidates for further evaluation. Particularly, EUS is an indispensable diagnostic modality for assessing the lesions precisely and evaluating the possibility of malignancy. The diagnostic ability of EUS appears increased by the combined use of contrast-enhancement or elastography. Histology is the gold standard for obtaining the final diagnosis. Tissue sampling requires special techniques to break the mucosal barrier. Although EUS-guided fine-needle aspiration (EUS-FNA) is commonly applied, mucosal cutting biopsy and mucosal incision-assisted biopsy are comparable methods to definitively obtain tissues from the exposed surface of lesions and seem more useful than EUS-FNA for small SETs. Recent advancements in artificial intelligence (AI) have a potential to drastically change the diagnostic strategy for SETs. Development and establishment of noninvasive methods including AI-assisted diagnosis are expected to provide an alternative to invasive, histological diagnosis.

Short-Term Healing Process of Artificial Ulcers after Gastric Endoscopic Submucosal Dissection

( Osamu Goto ),( Mitsuhiro Fujishiro ),( Shinya Kodashima ),( Chihiro Minatsuki ),( Keiko Niimi ),( Satoshi Ono ),( Nobutake Yamamichi ),( Kazuhiko Koike ) 대한소화기기능성질환·운동학회 2011 Gut and Liver Vol.5 No.3

Background/Aims: The relationship between the appearance of an ulcer and postoperative bleeding after gastric endoscopic submucosal dissection (ESD) is not well understood. To explore this potential relationship, we retrospectively analyzed the short-term healing process of ESD. Methods: A total of 520 consecutive lesions in 434 patients seen between January 2004 and December 2009 were retrospectively investigated. At the second-look endoscopy, which occurred between 1 and 8 days after ESD, artificial ulcers were categorized into 6 patterns according to Forrest`s classification: spurting bleeding, oozing bleeding, non-bleeding visible vessel, adherent clot, black base/spot, and clean base. From these data, a short-term healing model of the artificial ulcer was generated. Results: Ulcers were observed to change gradually from a bloody to a clean surface. The bleeding or non-bleeding visible vessel categories, which occurred in approximately one quarter of the ulcers within 3 days of ESD, were rarely observed 4 days after ESD. Conclusions: Ulcers that occur after gastric ESD heal in line with a specific time course, and it appears that most healing occurs without massive bleeding. (Gut Liver 2011;5:293-297)

Horizontal Distribution and Seasonal Change of Picophytoplankton in SurFace Water of Lake Biwa

Goto, Naoshige,Mitamura, Osamu,Masaki, Kihira The Korean Society of Limnology 2005 생태와 환경 Vol.38 No.S

Seasonal change in cell number and biomass expressed as chlorophyll a of picophytoplankton community in surface waters was investigated in the north basin of Lake Biwa from September 2001 to November 2002. Two main peaks, in May and summer (from July to October), were observed by change of the cell density of picophytoplankton. It is considered that peak in May was due to water temperature rise and summer peak was attributed to mass-specific nutrient uptake by picophytoplankton. Horizontal distribution in cell number and biomass of picophytoplankton community in surface water of Lake Biwa was investigated at 56 stations on June 6 ${\sim}$ 7 2002. DIN and DIP concentrations were lower in the north basin than in the south basin. The cell density and chlorophyll a of picophytoplankton were distributed almost uniformly in all area. The contribution of picophytoplankton to total phytoplankton chlorophyll a was higher in the north basin than in the south basin. These results suggest that picophytoplankton is important as a primary producer in low nutrient periods and areas of Lake Biwa.

EST analysis of regenerating newt retina

Hisatomi, Osamu,Hasegawa, Akiyuki,Goto, Tatsushi,Yamamoto, Shintaro,Sakami, Sanae,Kobayashi, Yuko,Tokunaga, Fumio Korean Society of Photoscience 2002 Journal of Photosciences Vol.9 No.2

A vertebrate retina is an organ belonging to the central nerve system (CNS), and is usually difficult to regenerate except at an embryonic stage in life. However, certain species of urodele amphibians, such as newts and salamanders, possess the ability to regenerate a functional retina from retinal pigment epithelial (RPE) cells even as adults. After surgical removal of neural retinas from adult newt eyes, the remaining RPE cells lose their pigment granules, transdifferentiate into retinal progenitor cells, which further differentiate into various retinal neurons, and then finally reform a functional neural network. To understand the molecular mechanisms of CNS regeneration, we attempted to investigate the genes expressing in regenerating newt retina. mRNAs were isolated from regenerating retinas at 18-19 days after the surgical removal of the normal retina, and a cDNA library (regenerating retinal cDNA library) were constructed. Our EST analysis of 112 clones in the regenerating cDNA library revealed that about 70% clones are closely related to the genes previously identified. About 40% clones are housekeeping genes, and about 15% clones encode proteins related to the regulation of gene expression and to the proliferation of the cells. Sequences similar to neural retina- and RPE-specific genes were not detected at all. These results led us to suppose that the regenerating retinal cells are in a state considerably different from those of neither neural retina nor RPE cells.

Influence of Signal Intensity Non-Uniformity on Brain Volumetry Using an Atlas-Based Method

Masami Goto,Osamu Abe,Tosiaki Miyati,Hiroyuki Kabasawa,Hidemasa Takao,Naoto Hayashi,Tomomi Kurosu,Takeshi Iwatsubo,Fumio Yamashita,Hiroshi Matsuda,Harushi Mori,Akira Kunimatsu,Shigeki Aoki,Kenji Ino,K 대한영상의학회 2012 Korean Journal of Radiology Vol.13 No.4

Objective: Many studies have reported pre-processing effects for brain volumetry; however, no study has investigated whether non-parametric non-uniform intensity normalization (N3) correction processing results in reduced system dependency when using an atlas-based method. To address this shortcoming, the present study assessed whether N3 correction processing provides reduced system dependency in atlas-based volumetry. Materials and Methods: Contiguous sagittal T1-weighted images of the brain were obtained from 21 healthy participants, by using five magnetic resonance protocols. After image preprocessing using the Statistical Parametric Mapping 5 software, we measured the structural volume of the segmented images with the WFU-PickAtlas software. We applied six different bias-correction levels (Regularization 10, Regularization 0.0001, Regularization 0, Regularization 10 with N3, Regularization 0.0001 with N3, and Regularization 0 with N3) to each set of images. The structural volume change ratio (%) was defined as the change ratio (%) = (100 x [measured volume - mean volume of five magnetic resonance protocols] / mean volume of five magnetic resonance protocols) for each bias-correction level. Results: A low change ratio was synonymous with lower system dependency. The results showed that the images with the N3 correction had a lower change ratio compared with those without the N3 correction. Conclusion: The present study is the first atlas-based volumetry study to show that the precision of atlas-based volumetry improves when using N3-corrected images. Therefore, correction for signal intensity non-uniformity is strongly advised for multi-scanner or multi-site imaging trials. Objective: Many studies have reported pre-processing effects for brain volumetry; however, no study has investigated whether non-parametric non-uniform intensity normalization (N3) correction processing results in reduced system dependency when using an atlas-based method. To address this shortcoming, the present study assessed whether N3 correction processing provides reduced system dependency in atlas-based volumetry. Materials and Methods: Contiguous sagittal T1-weighted images of the brain were obtained from 21 healthy participants, by using five magnetic resonance protocols. After image preprocessing using the Statistical Parametric Mapping 5 software, we measured the structural volume of the segmented images with the WFU-PickAtlas software. We applied six different bias-correction levels (Regularization 10, Regularization 0.0001, Regularization 0, Regularization 10 with N3, Regularization 0.0001 with N3, and Regularization 0 with N3) to each set of images. The structural volume change ratio (%) was defined as the change ratio (%) = (100 x [measured volume - mean volume of five magnetic resonance protocols] / mean volume of five magnetic resonance protocols) for each bias-correction level. Results: A low change ratio was synonymous with lower system dependency. The results showed that the images with the N3 correction had a lower change ratio compared with those without the N3 correction. Conclusion: The present study is the first atlas-based volumetry study to show that the precision of atlas-based volumetry improves when using N3-corrected images. Therefore, correction for signal intensity non-uniformity is strongly advised for multi-scanner or multi-site imaging trials.

Environmental Pollutants Drained From Highway Pavement Road

Takemura, Shinsaku,Goto, Naoshige,Mitamura, Osamu The Korean Society of Limnology 2005 생태와 환경 Vol.38 No.S

Environmental polluting materials from road surface drainage are a significant nonpoint source influenced to the eutrophication of lake and ecosystems with a transport development in recent years. To elucidate the discharge characteristics, the changing patterns in concentrations of polluting materials such as suspended solid (SS), chemical oxygen demand (COD), nitrogenous and phosphorus nutrients in drainage waters, were investigated during rainfall. Load variation of COD concentration in drainage water samples was closely related to that of SS concentration. This indicates that SS contained a greater part of organic matter. A quite difference between the past pavement and the new well-drainage pavement system was observed in the concentrations of SS and COD in drainage waters. Appreciable concentrations of nitrite and nitrate were determined in drainage waters. The present results indicate that the drainage water from road surfaces is a significant nonpoint source, and that the well-drainage pavement system introduced to skid prevention has an effect on the decreases of pollutants.

Three-Dimensional Flexible Endoscopy Can Facilitate Efficient and Reliable Endoscopic Hand Suturing: An ex-vivo Study

Jun Omori,Osamu Goto,Kazutoshi Higuchi,Takamitsu Umeda,Naohiko Akimoto,Masahiro Suzuki,Kumiko Kirita,Eriko Koizumi,Hiroto Noda,Teppei Akimoto,Mitsuru Kaise,Katsuhiko Iwakiri 대한소화기내시경학회 2020 Clinical Endoscopy Vol.53 No.3

Background/Aims: Three-dimensional (3D) flexible endoscopy, a new imaging modality that provides a stereoscopic view, canfacilitate endoscopic hand suturing (EHS), a novel intraluminal suturing technique. This ex-vivo pilot study evaluated the usefulnessof 3D endoscopy in EHS. Methods: Four endoscopists (two certified, two non-certified) performed EHS in six sessions on a soft resin pad. Each sessioninvolved five stitches, under alternating 3D and two-dimensional (2D) conditions. Suturing time (sec/session), changes in suturingtime, and accuracy of suturing were compared between 2D and 3D conditions. Results: The mean suturing time was shorter in 3D than in 2D (9.8±3.4 min/session vs. 11.2±5.1 min/session) conditions and EHSwas completed faster in 3D conditions, particularly by non-certified endoscopists. The suturing speed increased as the 3D sessionsprogressed. Error rates (failure to grasp the needle, failure to thread the needle, and puncture retrial) in the 3D condition were lowerthan those in the 2D condition, whereas there was no apparent difference in deviation distance. Conclusions: 3D endoscopy may contribute to increasing the speed and accuracy of EHS in a short time period. Stereoscopicviewing during 3D endoscopy may help in efficient skill acquisition for EHS, particularly among novice endoscopists.

Horizontal Distribution and Seasonal Change of Picophytoplankton in Surface Water of Lake Biwa

Kihira, Masaki,Naoshige Goto,Osamu Mitamura 한국수생태학회(구 한국하천호수학회) 2005 생태와 환경 Vol.38 No.S

Horizontal Distribution and Seasonal Change of Picophytoplankton in Surface Water of Lake Biwa

( Kihira Masaki ),( Naoshige Goto ),( Osamu Mitamura ) 한국하천호수학회 2005 생태와 환경 Vol.38 No.S

The Efficacy of an Endoscopic Grasp-and-Traction Device for Gastric Endoscopic Submucosal Dissection: An Ex Vivo Comparative Study (with Video)

Dirk W. Schölvinck,Osamu Goto,Jacques J. G. H. M. Bergman,Naohisa Yahagi,Bas L. A. M. Weusten 대한소화기내시경학회 2015 Clinical Endoscopy Vol.48 No.3

Background/Aims: To investigate whether the EndoLifter (Olympus), a counter-traction device facilitating submucosal dissection, can accelerate endoscopic submucosal dissection (ESD). Methods: Two endoscopists (novice/expert in ESD) performed 64 ESDs (artificial 3-cm lesions) in 16 ex vivo pig stomachs: per stomach, two at the posterior wall (forward approach) and two at the lesser curvature (retroflex approach). Per approach, one lesion was dissected with (EL+) and one without (EL–) the EndoLifter. The submucosal dissection time (SDT), corrected for specimen size, and the influence of ESD experience on EndoLifter usefulness were assessed. Results: En bloc resection rate was 98.4%. In the forward approach, the median SDT was shorter with the EndoLifter (0.56 min/cm2 vs. 0.91 min/cm2), although not significantly (p=0.09). The ESD-experienced endoscopist benefitted more from the EndoLifter (0.45 [EL+] min/cm2 vs. 0.68 [EL–] min/cm2, p=0.07) than the ESD-inexperienced endoscopist (0.77 [EL+] min/cm2 vs. 1.01 [EL–] min/cm2, p=0.48). In the retroflex approach, the median SDTs were 1.06 (EL+) and 0.48 (EL–) min/cm2 (p=0.16). The EndoLifter did not shorten the SDT for the ESD-experienced endoscopist (0.68 [EL+] min/cm2 vs. 0.68 [EL–] min/cm2, p=0.78), whereas the ESD-inexperienced endoscopist seemed hindered (1.65 [EL+] min/cm2 vs. 0.38 [EL–] min/cm2, p=0.03). Conclusions: In gastric ESD, the EndoLifter, in trend, shortens SDTs in the forward, but not in the retroflex approach. Given the low numbers in this study, a type II error cannot be excluded.