Taiga Chiyo

Mr. Taiga Chiyo


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Verified
Journal Article
Open access
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TCTaiga Chiyo
Taiga Chiyo
KFKoji Fujita
Koji Fujita
HIHisakazu Iwama
Hisakazu Iwama
Shintaro FujiharaShintaro Fujihara
Shintaro Fujihara
TTTomoko Tadokoro
Tomoko Tadokoro
TMTsutomu Masaki
Tsutomu Masaki
Galectin-9 (Gal-9) enhances tumor immunity mediated by T cells, macrophages, and dendritic cells. Its expression level in various cancers correlates with prognosis. Furthermore, Gal-9 directly induces apoptosis in various cancers; however, its mechanism of action and bioactivity has not been clarified. We evaluated Gal-9 antitumor effect against esophageal squamous cell carcinoma (ESCC) to analyze the dynamics of apoptosis-related molecules, elucidate its mechanism of action, and identify relevant changes in miRNA expressions. KYSE-150 and KYSE-180 cells were treated with Gal-9 and their proliferation was evaluated. Gal-9 inhibited cell proliferation in a concentration-dependent manner. The xenograft mouse model established with KYSE-150 cells was administered with Gal-9 and significant suppression in the tumor growth observed. Gal-9 treatment of KYSE-150 cells increased the number of Annexin V-positive cells, activation of caspase-3, and collapse of mitochondrial potential, indicating apoptosis induction. c-Jun NH2-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38) phosphorylation were activated and could be involved in apoptosis. Therefore, Gal-9 induces mitochondria-mediated apoptosis of ESCC and inhibits cell proliferation in vitro and in vivo with JNK and p38 activation.

Verified
Journal Article
Open access
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TMTakanori Matsui
Takanori Matsui
TCTaiga Chiyo
Taiga Chiyo
Hideki KobaraHideki Kobara
Hideki Kobara
Shintaro FujiharaShintaro Fujihara
Shintaro Fujihara
KFKoji Fujita
Koji Fujita
TMTsutomu Masaki
Tsutomu Masaki
Esophageal squamous cell carcinoma (ESCC) is the most common primary esophageal malignancy. Telmisartan, an angiotensin II type 1 (AT1) receptor blocker (ARB) and a widely used antihypertensive, has been shown to inhibit proliferation of various cancer types. This study evaluated the effects of telmisartan on human ESCC cell proliferation in vitro and in vivo and sought to identify the microRNAs (miRNAs) involved in these antitumor effects. We examined the effects of telmisartan on three human ESCC cell lines (KYSE150, KYSE180, and KYSE850). Telmisartan inhibited proliferation of these three cell lines by inducing S-phase arrest, which was accompanied by decreased expression of cyclin A2, cyclin-dependent kinase 2, and other cell cycle-related proteins. Additionally, telmisartan reduced levels of phosphorylated ErbB3 and thrombospondin-1 in KYSE180 cells. Furthermore, expression of miRNAs was remarkably altered by telmisartan in vitro. Telmisartan also inhibited tumor growth in vivo in a xenograft mouse model. In conclusion, telmisartan inhibited cell proliferation and tumor growth in ESCC cells by inducing cell-cycle arrest.

13 March 2020 in Journal of Gastrointestinal and Liver Diseases
Verified
Journal Article
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Hideki KobaraHideki Kobara
Hideki Kobara
YMYoichi Miyaoka
Yoichi Miyaoka
YIYoshio Ikeda
Yoshio Ikeda
TYTakayoshi Yamada
Takayoshi Yamada
MTMasashi Takata
Masashi Takata
TMTsutomu Masaki
Tsutomu Masaki
Background and Aims: Endoscopic submucosal dissection (ESD) seems to be a reasonable option for gastrointestinal subepithelial lesions (SELs) localized within the submucosa. Indications for ESD include small neuroendocrine tumors (NETs) and indeterminate SELs. However, the prospective data regarding ESD and surveillance remain unclear. This study was performed to prospectively investigate the outcomes of ESD, including organ-specific outcomes and the mid-term prognosis. Methods: This prospective multicenter study included 57 patients who underwent ESD for SELs localized within the submucosa [definite NETs (n = 42) and indeterminate SELs (n = 15)]. The efficacy and safety of ESD were evaluated in the whole cohort and in subgroups (NETs and indeterminate SELs). All patients were followed up. Results: The rates of en bloc resection, curative resection, and complications were 98.2%, 66.7%, and 7.7% for the overall population (n=57); 100%, 61.9%, and 2.4% for NETs (n=42); and 93.3%, 80.0%, and 20.0% for indeterminate SELs (n=15), respectively. The rates of curative resection for NETs were poorer in the stomach (20%, n=5) and duodenum (33%, n=3) than in the rectum (71%, n=34). Including 11 of 16 patients with NETs who underwent a conservative approach resulting in non-curative resection, no patients developed tumor recurrence during the follow-up period (median, 24.5 months; range, 1–60 months). ESD followed by surveillance demonstrated acceptable mid-term outcomes for non-curative NETs. Conclusions: ESD can be an efficient therapy for SELs localized within the submucosa. However, gastric and duodenal ESD for NETs may be limited in terms of its curative and technical aspects. Clinicians should be aware of the potential complications of ESD for indeterminate SELs.

Verified
Journal Article
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典西典子 西山
典子 西山
Hideki KobaraHideki Kobara
Hideki Kobara
MAMaki Ayaki
Maki Ayaki
Shintaro FujiharaShintaro Fujihara
Shintaro Fujihara
KNKaho Nakatani
Kaho Nakatani
KHKen Haruma
Ken Haruma
White globe appearance (WGA) is defined as a microendoscopic white lesion with a globular shape underlying the gastric epithelium and is considered a marker of gastric cancer. We recently reported that endoscopically visualized white spot (WS) corresponding to WGA appeared on the nonatrophic mucosa of patients with acid-suppressing agents (A-SA) use. We evaluated patients undergoing routine esophagogastroduodenoscopy and divided the patients into an A-SA group (n = 112) and a control group (n = 158). We compared the presence of WS in both groups. We also compared WS-positive- (n = 31) and -negative (n = 43) groups within the A-SA group regarding these patients’ backgrounds and serum gastrin concentrations. Comparing the A-SA group with controls, the prevalence of WS was significantly higher (31/112 vs. 2/158; p < 0.001). The number of patients with high serum gastrin concentrations was significantly higher in the WS-positive group (18/31) vs. the WS-negative group (5/43) (p < 0.001). Within the A-SA group, the prevalence of WS was also significantly higher in patients taking potassium-competitive acid blockers vs. proton-pump inhibitors (21/31 vs. 10/31, p < 0.001). The WS-positive group had a significantly greater percentage of patients, with a high serum gastrin level (p < 0.001). WS may be associated with hypergastrinemia and potassium-competitive acid blockers.

9 December 2019 in Journal of Gastrointestinal and Liver Diseases
Verified
Journal Article
Open access
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典西典子 西山
典子 西山
Hideki KobaraHideki Kobara
Hideki Kobara
SFShintaro Fujihara
Shintaro Fujihara
KKKazuhiro Kozuka
Kazuhiro Kozuka
TCTaiga Chiyo
Taiga Chiyo
TMTsutomu Masaki
Tsutomu Masaki
Background and Aims: Endoscopic submucosal dissection (ESD) has become a standard treatment for early gastric neoplasia. However, as the upper and middle body of the greater curvature has a rich vasculature and submucosal fibrosis, ESD of neoplasia in these locations requires a specific strategy. We aimed to investigate the efficacy and safety of the J-shaped superficial cutting and splashed submucosal dissection (JSCS) technique for neoplasia of the greater curvature by comparing ESD using JSCS with conventional ESD. Methods: Twenty-two patients who underwent ESD for gastric neoplasia affecting the upper and middle body of the greater curvature were divided into two groups for retrospective analysis. Nine patients underwent conventional ESD (c-Group), while 13 underwent ESD with JSCS (j-Group). Primary outcome was the en bloc resection rate. Secondary outcomes included complete resection (R0) rate, procedure time, perforation rate, total bleeding time, and the total number of massive bleeding events and of hemostatic forceps times applied during ESD. Results: There were no significant differences between both groups (c-Group vs j-Group) in en bloc resection rate, or R0 resection rate. Compared with the c-Group, the j-Group tended to have a decreased mean procedure time (mean 133 minutes vs 74 minutes, p=0.11) and perforation rate (11% vs 0%, p=0.41). Compared with the c-Group, the j-Group had significantly fewer bleeding incidents (13.4 times vs 6.6 times, p=0.0095), shorter total bleeding time (17.6 min vs 7.4 min, p=0.036), and fewer usages of hemostatic forceps (6.3 times vs 2.4 times, p=0.026) during ESD. Conclusion: Endoscopic submucosal dissection with JSCS is superior to conventional ESD, as it reduces intraprocedural bleeding. This technique has the potential to become the standard strategy for neoplasia affecting the upper and middle body of the greater curvature.

14 September 2021 in Diagnostics
Verified
Journal Article
Open access
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Shintaro FujiharaShintaro Fujihara
Shintaro Fujihara
Hideki KobaraHideki Kobara
Hideki Kobara
典西典子 西山
典子 西山
NTNaoya Tada
Naoya Tada
KKKazuhiro Kozuka
Kazuhiro Kozuka
TMTsutomu Masaki
Tsutomu Masaki
Esophagogastroduodenoscopy (EGD) has a high risk of virus transmission during the current coronavirus disease 2019 era, and preventive measures are under investigation. We investigated the effectiveness of a newly developed patient-covering negative-pressure box system (Endo barrier®) (EB) for EGD. Eighty consecutive unsedated patients who underwent screening EGD with EB use were prospectively enrolled. To examine the aerosol ratio before, during, and after EGD, 0.3- and 0.5-μm aerosols were measured every 60 s using an optical counter. Moreover, the degree of contamination of the examiners’ goggles and vinyl gowns was assessed before and after EGD using a rapid adenosine triphosphate (ATP) test for simulated droplets. Data were available in 73 patients and showed that 0.3- and 0.5-μm particles did not increase in 95.8% (70/73) and 94.5% (69/73) of patients during EGD under EB. There were no significant differences in the total 0.3- or 0.5-μm particle counts before versus after EGD. The difference in the ATP levels before and after EGD was −0.6 ± 16.6 relative light units (RLU) on goggles and 1.59 ± 19.9 RLU on gowns (both within the cutoff value). EB use during EGD may provide a certain preventive effect against aerosols and droplets, decreasing examiners’ exposure to viruses.