Shohei Asada

Dr. Shohei Asada


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

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

Representative Publications

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19 March 2024 in Cells
Verified
Journal Article
Open access
PDF file
SAShohei Asada
Shohei Asada
KKKosuke Kaji
Kosuke Kaji
NNNorihisa Nishimura
Norihisa Nishimura
AKAritoshi Koizumi
Aritoshi Koizumi
TMTakuya Matsuda
Takuya Matsuda
HYHitoshi Yoshiji
Hitoshi Yoshiji
Background: Liver cirrhosis leads to portal hypertension (PH) with capillarization of liver sinusoidal endothelial cells (LSECs), although drug treatment options for PH are currently limited. Sodium glucose transporter 2 inhibitors, which are antidiabetic agents, have been shown to improve endothelial dysfunction. We aimed to elucidate the effect of tofogliflozin on PH and liver fibrosis in a rat cirrhosis model. Methods: Male-F344/NSlc rats repeatedly received carbon tetrachloride (CCl4) intraperitoneally to induce PH and liver cirrhosis alongside tofogliflozin (10 or 20 mg/kg). Portal hemodynamics and hepatic phenotypes were assessed after 14 weeks. An in vitro study investigated the effects of tofogliflozin on the crosstalk between LSEC and activated hepatic stellate cells (Ac-HSC), which are relevant to PH development. Results: Tofogliflozin prevented PH with attenuated intrahepatic vasoconstriction, sinusoidal capillarization, and remodeling independent of glycemic status in CCl4-treated rats. Hepatic macrophage infiltration, proinflammatory response, and fibrogenesis were suppressed by treatment with tofogliflozin. In vitro assays showed that tofogliflozin suppressed Ac-HSC-stimulated capillarization and vasoconstriction in LSECs by enhancing the antioxidant capacity, as well as inhibited the capilliarized LSEC-stimulated contractive, profibrogenic, and proliferative activities of Ac-HSCs. Conclusions: Our study provides strong support for tofogliflozin in the prevention of liver cirrhosis-related PH.

26 March 2022 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
HTHiroaki Takaya
Hiroaki Takaya
TNTadashi Namisaki
Tadashi Namisaki
SAShohei Asada
Shohei Asada
SISatoshi Iwai
Satoshi Iwai
TKTakahiro Kubo
Takahiro Kubo
HYHitoshi Yoshiji
Hitoshi Yoshiji
ADAMTS13 specifically cleaves the multimeric von Willebrand factor (VWF), and an imbalance between ADAMTS13 activity (ADAMTS13:AC) and VWF antigen (VWF:Ag) levels is associated with the severity of liver cirrhosis (LC). However, the reason for this imbalance in patients with LC is unknown. This study investigated the relationship among ADAMTS13:AC, VWF:Ag, and endotoxin (Et) levels in patients with LC. ADAMTS13:AC and VWF:Ag levels were determined using ELISA, whereas Et levels were estimated using a chromogenic substrate assay. The levels of ADAMTS13 inhibitor (ADAMTS13:INH) were evaluated by measuring the extent that heat-inactivated patient’s plasma reduces the ADAMTS13:AC of the control. The status (degraded, normal, or unusually large [UL]) of the VWF multimer (VWFM) was determined through vertical agarose gel electrophoresis. ADAMTS13:AC, VWF:Ag, and Et levels decreased, increased, and increased, respectively, with the severity of LC. Patients with cirrhosis with high Et levels had lower and higher ADAMTS13:AC and VWF:Ag levels, respectively, than those with low Et levels. Patients with cirrhosis with detectable ADAMTS13:INH had higher Et levels than those with undetectable ADAMTS13:INH. Patients whose VWFM was either normal or UL had higher Et levels than those with degraded VWFM. In conclusion, ADAMTS13, VWF, and Et may be interrelated and associated with the severity of LC via hypercoagulability.

29 June 2023 in Diagnostics
Verified
Journal Article
Open access
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ASAkihiko Shibamoto
Akihiko Shibamoto
TNTadashi Namisaki
Tadashi Namisaki
JSJunya Suzuki
Junya Suzuki
TKTakahiro Kubo
Takahiro Kubo
SISatoshi Iwai
Satoshi Iwai
HYHitoshi Yoshiji
Hitoshi Yoshiji
Alcohol is a major risk factor of liver cirrhosis (LC). This study aimed to elucidate a surrogate marker of sarcopenia in patients with LC of different etiology. Out of 775 patients with LC, 451 were assessed for handgrip strength and skeletal muscle mass (by computed tomography). They were then divided into two groups: alcoholic cirrhosis (AC; n = 149) and nonalcoholic cirrhosis (NAC; n = 302). Endotoxin activity (EA) levels were measured with an EA assay. Group AC showed significantly higher platelet counts (p = 0.027) and lower blood urea nitrogen levels and fibrosis-4 index than group NAC (p = 0.0020 and p = 0.038, respectively). The risk factors of sarcopenia were age ≥ 65 years, female sex, CP-C LC, Hb levels < 12 g/dL, and EA level > 0.4 in all patients with LC; hemoglobin (Hb) levels < 12 g/dL and EA level > 0.4 in group AC; and age ≥ 65 years, CP-C LC, and Hb levels < 12 g/dL in group NAC. The prediction accuracy of Hb for sarcopenia in group AC, group NAC, and all patients was 83.6%, 75.9%, and 78.1% (sensitivity: 92.0%, 69.0%, and 80.2%; specificity: 66.4%, 71.0%, and 64.0%), respectively. Although not significant, the predictive performance was better when using the combination of Hb and EA measurements than when using Hb alone in group AC but was comparable in all patients. Hb levels can predict sarcopenia in patients with LC, but in those with AC, the combination of Hb and EA improves the prediction performance.

Verified
Journal Article
Open access
PDF file
JSJunya Suzuki
Junya Suzuki
TNTadashi Namisaki
Tadashi Namisaki
HTHiroaki Takaya
Hiroaki Takaya
KKKosuke Kaji
Kosuke Kaji
NNNorihisa Nishimura
Norihisa Nishimura
HYHitoshi Yoshiji
Hitoshi Yoshiji
Portal vein thrombosis (PVT), one of the most prevalent hepatic vascular conditions in patients with liver cirrhosis (LC), is associated with high mortality rates. An imbalance between a disintegrin-like metalloproteinase with thrombospondin type-1 motifs 13 (ADAMTS-13) enzyme and von Willebrand factor (VWF) is responsible for hypercoagulability, including spontaneous thrombus formation in blood vessels. Herein, we aimed to identify potential prognostic and diagnostic biomarkers in Japanese patients with LC and PVT. In total, 345 patients were divided into two groups: 40 patients who developed PVT (PVT group) and 305 who did not develop PVT (NPVT group). Among the 345 patients with LC, 81% (279/345) were deemed ineligible due to the presence of preventive comorbidities, active or recent malignancies, and organ dysfunction. The remaining 66 patients were divided into two groups: the PVT group (n = 33) and the NPVT group (n = 33). Plasma ADAMTS-13 activity (ADAMTS-13:AC) and the vWF antigen (VWF:Ag) were measured using enzyme-linked immunosorbent assays. Contrast-enhanced, three-dimensional helical computed tomography (CT) was used to detect and characterize PVT. ADAMTS-13:AC was significantly lower in the PVT group than in the NPVT group. No significant differences in plasma vWF:Ag or liver stiffness were observed between the two groups. ADAMTS-13:AC of <18.8 was an independent risk factor for PVT on multivariate analyses (odds ratio: 1.67, 95% confidence interval: 1.21–3.00, p < 0.002). The receiver operating characteristic analysis of ADAMTS-13:AC revealed an area under the curve of 0.913 in PVT detection. Patients with PVT having ADAMTS-13:AC ≥18.8 (n = 17) had higher albumin levels and better prognoses than those with ADAMTS-13:AC <18.8 (n = 16). No significant correlations of ADAMTS-13:AC levels with either fibrin degradation product or D-dimer levels were observed. ADAMTS-13:AC levels could be potential diagnostic and prognostic biomarkers for PVT in Japanese patients with LC.

15 October 2024 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
KKKoh Kitagawa
Koh Kitagawa
AMAkira Mitoro
Akira Mitoro
HSHisae Suzuki
Hisae Suzuki
FTFumimasa Tomooka
Fumimasa Tomooka
SAShohei Asada
Shohei Asada
HYHitoshi Yoshiji
Hitoshi Yoshiji
Recently, endoscopic ultrasound-guided tissue acquisition (EUS-TA) has been widely used to diagnose pancreatic ductal adenocarcinoma (PDAC). The histological examination of core tissues acquired using novel biopsy needles is the primary diagnostic approach for patients with PDAC. However, in patients with early-stage PDAC, such as Stages 0 and I, EUS-TA can be challenging, and its diagnostic accuracy may be limited. This presents a clinical dilemma: The earlier that clinicians attempt to accurately diagnose PDAC, the more difficult it becomes to do so using EUS-TA. Liquid-based cytology (LBC) is a technique for preparing pathological specimens from liquefied cytology specimens by placing the collected material in a special fixative preservative fluid. LBC offers advantages, such as specimen optimization with reduced blood interference, a high cell-collection rate, and the simplicity of the procedure in the endoscopy room. The use of LBC may improve diagnostic accuracy, particularly for early-stage PDAC. Therefore, we emphasize that cytology remains a valuable tool for the endoscopic diagnosis of PDAC. In this review, we discuss the role of LBC in the endoscopic diagnosis of PDAC.

11 February 2026 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
KKKoh Kitagawa
Koh Kitagawa
SAShohei Asada
Shohei Asada
JHJunichi Hanatani
Junichi Hanatani
YMYuki Motokawa
Yuki Motokawa
YOYui Osaki
Yui Osaki
HYHitoshi Yoshiji
Hitoshi Yoshiji
Endoscopic biliary drainage using self-expanding metal stents (SEMSs) is a standard palliative therapy for cholangitis and obstructive jaundice caused by malignant distal biliary obstruction (MDBO). Fully-covered SEMSs (FC-SEMSs) prevent tumor ingrowth and provide longer patency; however, recent advances in chemotherapy have increased stent migration due to tumor shrinkage, resulting in reduced functional patency compared with uncovered SEMSs. Partially covered SEMSs can reduce migration but are often difficult to remove after deployment. In addition, adverse events such as acute pancreatitis and cholecystitis remain a concern with FC-SEMSs. To address these limitations, Dr. Kobayashi introduced a novel porous SEMS with multiple side holes in the covering membrane (MH-SEMSs) in 2019. This design allows limited bile duct epithelial ingrowth through side holes, providing anchorage while maintaining removability. The side-hole structure may also reduce cholecystitis and pancreatitis by preserving flow through the pancreatic and cystic duct orifices. Over five years since their introduction, clinical evidence supporting MH-SEMSs has steadily increased. This review summarizes current data and explores future perspectives for MH-SEMS use in MDBO management.