Akira Mitoro

Dr. Akira Mitoro

orcid

Research Focus & Metrics

Academic Career Length

37Years (1990-Present)

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

Representative Publications

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29 June 2022 in Digestive Endoscopy
Verified
Journal Article
Closed access
MKMasayuki Kitano
Masayuki Kitano
MYMakoto Yoshida
Makoto Yoshida
RAREIKO ASHIDA
REIKO ASHIDA
EKEmiri Kita
Emiri Kita
AKAkio Katanuma
Akio Katanuma
HYHiroki Yamaue
Hiroki Yamaue

29 March 2020 in Antibiotics
Verified
Journal Article
Open access
PDF file
KKKosuke Kaji
Kosuke Kaji
SSSoichiro Saikawa
Soichiro Saikawa
HTHiroaki Takaya
Hiroaki Takaya
YFYukihisa Fujinaga
Yukihisa Fujinaga
MFMasanori Furukawa
Masanori Furukawa
HYHitoshi Yoshiji
Hitoshi Yoshiji
Rifaximin is a poorly absorbable antibiotic against hepatic encephalopathy (HE). This observational study aimed to elucidate the effect of rifaximin on intestinal permeability and gut microbiota in patients with decompensated cirrhosis. Thirty patients with decompensated cirrhosis were assessed by ammonia level, neuropsychological testing, endotoxin activity (EA), and serum proinflammatory cytokines at baseline and after four weeks of rifaximin treatment (1200 mg/day). Intestinal permeability was indicated by serum soluble CD163 (sCD163), mannose receptor (sMR), and zonulin levels. To evaluate the gut microbiome, 16S ribosomal RNA gene sequencing was applied. Rifaximin ameliorated hyperammonemia and cognitive dysfunction, although it did not change the serum proinflammatory cytokine levels. It decreased EA levels as well as serum levels of sCD163 and sMR, but not zonulin, and both decreases in sCD163 and sMR showed positive correlations with EA decrease (ΔsCD163: Correlation coefficient (R) = 0.680, p = 0.023; ΔsMR: R = 0.613, p = 0.014, vs. ΔEA). Gut microbial analysis revealed that the richness and complexity of species were unchanged while the abundance of the Streptococcus genus was reduced after treatment with rifaximin. Collectively, rifaximin alleviated HE and endotoxemia with improved intestinal hyperpermeability in patients with decompensated cirrhosis, and this effect is partially involved in a gut microbial change.

1 November 2018 in United European Gastroenterology Journal
Verified
Journal Article
Open access
PDF file
HTHiroaki Takaya
Hiroaki Takaya
HKHideto Kawaratani
Hideto Kawaratani
YTYuki Tsuji
Yuki Tsuji
KNKeisuke Nakanishi
Keisuke Nakanishi
SSSoichiro Saikawa
Soichiro Saikawa
HYHitoshi Yoshiji
Hitoshi Yoshiji
Background: Several noninvasive biomarkers are available for diagnosing liver fibrosis stage and predicting hepatocellular carcinoma (HCC) development in patients with chronic hepatitis and liver cirrhosis. However, these biomarkers are not sufficiently accurate. Recently, von Willebrand factor (VWF) has been related to angiogenesis and apoptosis. Furthermore, VWF is associated with hepatic spare ability and HCC.Objective: We aimed to determine whether VWF is a potential biomarker for liver fibrosis and HCC development.Methods: Two hundred and twelve patients with chronic hepatitis B and C were recruited. VWF antigen (VWF: Ag) levels in each patient were determined via enzyme‐linked immunosorbent assay. Univariable and multivariable analyses were used to determine the risk factor of HCC.Results: The VWF: Ag levels were higher in patients with severe liver fibrosis stage and/or HCC development than in those without. The area under the curve of VWF: Ag for diagnosis of severe liver fibrosis stage was 0.721. Multivariable analysis showed that only VWF: Ag was a predictive biomarker for HCC development.Conclusions: VWF: Ag is related to liver fibrosis and may be useful for predicting HCC development. VWF is a potentially useful biomarker to diagnose severe liver fibrosis and predict HCC development.

30 May 2021 in Clinical Endoscopy
Verified
Journal Article
Open access
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MFMasanori Furukawa
Masanori Furukawa
AMAkira Mitoro
Akira Mitoro
TOTakahiro Ozutumi
Takahiro Ozutumi
YFYukihisa Fujinaga
Yukihisa Fujinaga
KNKeisuke Nakanishi
Keisuke Nakanishi
HYHitoshi Yoshiji
Hitoshi Yoshiji
Endoscopic resection (ER) for superficial non-ampullary duodenal epithelial tumors (SNADETs) is challenging. Conventional endoscopic mucosal resection (CEMR) is also problematic due to the anatomical features of the duodenum. We compared the safety and efficacy of underwater endoscopic mucosal resection (UEMR) with those of CEMR through a retrospective analysis. Altogether, 44 consecutive patients with 46 SNADETs underwent ER (18 CEMR cases and 28 UEMR cases) between January 2016 and October 2019. We investigated the proportions of en bloc resection, R0 resection, complications, resection time, and total procedure time and compared the outcomes of patients from the CEMR group with those of patients from the UEMR group. The median tumor size was 8.0 mm (range, 2.0-20.0 mm). The UEMR group showed a higher proportion of en bloc resection (96.4% vs. 72.2%, p<0.05) and significantly lower median resection time and total procedure time (4 min vs. 9.5 min, p<0.05 and 13 min vs. 19 min, p<0.05; respectively) than the CEMR group. No complications were observed. However, two patients treated with piecemeal resection in the CEMR group had residual tumors. UEMR is a feasible therapeutic option for SNADETs. It can be recommended as a standard treatment.

Verified
Journal Article
Open access
PDF file
YFYukihisa Fujinaga
Yukihisa Fujinaga
HKHideto Kawaratani
Hideto Kawaratani
DKdaisuke kaya
daisuke kaya
YTYuki Tsuji
Yuki Tsuji
TOTakahiro Ozutsumi
Takahiro Ozutsumi
HYHitoshi Yoshiji
Hitoshi Yoshiji
The progression of nonalcoholic steatohepatitis (NASH) is complicated. The multiple parallel-hits theory is advocated, which includes adipocytokines, insulin resistance, endotoxins, and oxidative stress. Pathways involving the gut–liver axis also mediate the progression of NASH. Angiotensin-II receptor blockers (ARB) suppress hepatic fibrosis via the activation of hepatic stellate cells (HSCs). Rifaximin, a nonabsorbable antibacterial agent, is used for the treatment of hepatic encephalopathy and has been recently reported to improve intestinal permeability. We examined the inhibitory effects on and mechanism of hepatic fibrogenesis by combining ARB and rifaximin administration. Fischer 344 rats were fed a choline-deficient/l-amino acid-defined (CDAA) diet for 8 weeks to generate the NASH model. The therapeutic effect of combining an ARB and rifaximin was evaluated along with hepatic fibrogenesis, the lipopolysaccharide–Toll-like receptor 4 (TLR4) regulatory cascade, and intestinal barrier function. ARBs had a potent inhibitory effect on hepatic fibrogenesis by suppressing HSC activation and hepatic expression of transforming growth factor-β and TLR4. Rifaximin reduced intestinal permeability by rescuing zonula occludens-1 (ZO-1) disruption induced by the CDAA diet and reduced portal endotoxin. Rifaximin directly affect to ZO-1 expression on intestinal epithelial cells. The combination of an ARB and rifaximin showed a stronger inhibitory effect compared to that conferred by a single agent. ARBs improve hepatic fibrosis by inhibiting HSCs, whereas rifaximin improves hepatic fibrosis by improving intestinal permeability through improving intestinal tight junction proteins (ZO-1). Therefore, the combination of ARBs and rifaximin may be a promising therapy for NASH fibrosis.

14 December 2018 in Digestion
Verified
Journal Article
Closed access
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KTKOHEI TAKIZAWA
KOHEI TAKIZAWA
WHWaku Hatta
Waku Hatta
TGTakuji Gotoda
Takuji Gotoda
NKNoboru Kawata
Noboru Kawata
MNMasahiro Nakagawa
Masahiro Nakagawa
TSTooru Shimosegawa
Tooru Shimosegawa
Background/Aims: The outcomes of salvage surgery for recurrence after non-curative endoscopic submucosal dissection (ESD) without additional radical surgery for early gastric cancer (EGC) remain unclear. We determined the recurrence patterns and outcomes of salvage surgery in such cases using data from a multicenter, retrospective study. Methods: Of 15,785 patients who underwent ESD for EGC at 19 participating institutions between January 2000 and August 2011, 1,969 failed to meet the current curative criteria after ESD. Of these, 905 patients received no additional treatment. We evaluated the pattern of recurrence, clinical course after salvage surgery, and long-term survival rate for these patients. Results: Over a median 64-month follow-up period, recurrence was detected in 27 patients. Two patients with missing data were excluded. Three, seven, and 15 (60%) patients showed intragastric relapse, regional lymph node metastasis, and distant metastasis, respectively. The first line of treatment for recurrence in 1, 7, 6, and 11 patients was endoscopic treatment, salvage surgery, chemotherapy, and best supportive care, respectively. One patient survived without recurrence for 31 months after salvage surgery, one died of acute myocardial infarction 1 month after salvage surgery, and 5 showed recurrence at 0, 2, 3, 5, and 30 months after salvage surgery and eventually succumbed to the disease. The median survival times for all patients with recurrence and the 7 patients who underwent salvage surgery were 5 months after recurrence and 7 months after salvage surgery, respectively. Conclusion: The survival rate after salvage surgery for recurrence after non-curative ESD without additional radical surgery for EGC is quite low, with distant metastasis being the most common recurrence pattern in these cases.