Hiroshi Yamamoto

Dr. Hiroshi Yamamoto

orcid

Research Focus & Metrics

Academic Career Length

28Years (1999-Present)

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

Representative Publications

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1 December 2005 in Digestive Diseases and Sciences
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Journal Article
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HYHiroshi Yamamoto
Hiroshi Yamamoto
TMTsuyoshi Mori
Tsuyoshi Mori
HTHiroshi Tsuchihashi
Hiroshi Tsuchihashi
HAHiroya Akabori
Hiroya Akabori
HNHiroyuki Naito
Hiroyuki Naito
TTTohru Tani
Tohru Tani

18 June 2013 in PLOS ONE
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Journal Article
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VTVo Nguyen Trung
Vo Nguyen Trung
HYHiroshi Yamamoto
Hiroshi Yamamoto
AFAkira Furukawa
Akira Furukawa
TYTsuyoshi Yamaguchi
Tsuyoshi Yamaguchi
SMSatoshi Murata
Satoshi Murata
TTTohru Tani
Tohru Tani
Enhanced secretion of glucagon-like peptide-1 (GLP-1) has been suggested as a possible mechanism underlying the improvement in type 2 diabetes mellitus (T2DM) after laparoscopic sleeve gastrectomy (LSG). However, the reason for enhanced GLP-1 secretion during glucose challenge after LSG remains unclear because LSG does not include intestinal bypass. In this study, we focused on the effects of LSG on GLP-1 secretion and intestinal motility during the oral glucose tolerance test (OGTT) using cine magnetic resonance imaging (MRI) before and 3 months after LSG. LSG was performed in 12 obese patients with a body mass index >35 kg/m2. Six patients had T2DM. OGTT was performed before and 3 months after the surgery. Body weight, hemoglobin A1c (HbA1c), and GLP-1 levels during OGTT were examined, and intestinal motility during OGTT was assessed using cine MRI. Body weight was significantly decreased after surgery in all the cases. HbA1c was markedly decreased in all the diabetic subjects. In all cases, GLP-1 secretion during OGTT was enhanced and cine MRI showed markedly increased intestinal motility at 15 and 30 min during OGTT after LSG. LSG leads to accelerated intestinal motility and reduced intestinal transit time, which may be involved in the mechanism underlying enhanced GLP-1 secretion during OGTT after LSG.

1 June 2007 in Annals of Surgery
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Journal Article
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HAHIROYA AKABORI
HIROYA AKABORI
HYHiroshi Yamamoto
Hiroshi Yamamoto
HTHiroshi Tsuchihashi
Hiroshi Tsuchihashi
TMTsuyoshi Mori
Tsuyoshi Mori
KFKazunori Fujino
Kazunori Fujino
TTTohru Tani
Tohru Tani
Objective: To evaluate the role of transient receptor potential vanilloid 1 (TRPV1) in a rat hemorrhagic shock (HS) model using the TRPV1 antagonist, capsazepine (CPZ). Summary Background Data: TRPV1, distributed within the sensory nerve, plays a role in the regulation of cardiovascular functions. TRPV1 may be involved in the cardiovascular responses to HS. Methods: Male rats were anesthetized and HS was induced with the mean arterial pressure (MAP) at 30 mm Hg for 90 minutes. CPZ (5.0 μmol/kg) was administered at 30 minutes after the shock induction, and the 24-hour survival rates were assessed. The MAP, heart rate, and shed blood volume (SBV) were recorded throughout the experiment. Arterial blood gas analysis and the plasma catecholamines levels were measured before and after HS. Double-immunohistochemistry for Fos and tyrosine hydroxylase (TH) was performed in the rostral ventrolateral medulla (RVLM) of the brain. Results: CPZ significantly improved the 24-hour survival rates, which was accompanied by the increase in the MAP and the SBV, a decrease of the plasma catecholamines levels, and attenuation of the severe metabolic acidosis. Furthermore, CPZ reduced the percentage of double-labeled neurons for Fos and TH in the RVLM of the rat brain. Conclusions: TRPV1 may be involved in the regulation of the cardiovascular responses to HS, at least in part, by recruiting catecholaminergic neurons in the RVLM. CPZ appears to induce metabolic compensations, which may be potentially useful in HS.

16 July 2019 in Scientific Reports
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MMMahbub MH
Mahbub MH
NYNatsu Yamaguchi
Natsu Yamaguchi
HTHidekazu Takahashi
Hidekazu Takahashi
RHRyosuke Hase
Ryosuke Hase
HYHiroshi Yamamoto
Hiroshi Yamamoto
TTTsuyoshi Tanabe
Tsuyoshi Tanabe
The potential association between altered levels of plasma free amino acids (PFAAs) and uric acid (UA) with estimated glomerular filtration rate (eGFR) remains unknown among patients with hypertension. A total of 2804 healthy controls and 2455 hypertensive patients were included in the current analysis. eGFR was defined as reduced when it was <60 ml/min/1.73 m2. The associations between reduced eGFR and individual PFAAs and UA in the healthy control and hypertension groups were explored by logistic regression analyses adjusted for potential confounding variables. Results show that UA had a significant positive association with reduced eGFR in both healthy control and hypertension groups (P < 0.001). Among the PFAAs, citrulline, glycine and phenylalanine showed significant positive associations with reduced eGFR in both healthy control (P < 0.01 to 0.001) and hypertension (P < 0.001) groups. Moreover, alanine, asparagine and methionine achieved significant positive associations with reduced eGFR only in the hypertension group (P < 0.01 to 0.001). Conversely, serine showed significant inverse associations with reduced eGFR in the hypertension group only (P < 0.001). Our findings provide first evidence for a strong relationship between distinct patterns of PFAAs and elevated UA with reduced eGFR in hypertension. The findings may appear useful in developing effective strategies for the prevention or early detection and treatment of declined kidney function in hypertension.

7 January 2021 in Obesity Surgery
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MOMasayuki Ohta
Masayuki Ohta
YSYosuke Seki
Yosuke Seki
TOTetsuji Ohyama
Tetsuji Ohyama
RBRixing Bai
Rixing Bai
SKSang Hyun Kim
Sang Hyun Kim
KKKazunori Kasama
Kazunori Kasama

9 October 2020 in World Journal of Surgery
Verified
Journal Article
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TYTsuyoshi Yamaguchi
Tsuyoshi Yamaguchi
HYHiroshi Yamamoto
Hiroshi Yamamoto
YTYuki Tomozawa
Yuki Tomozawa
SUSatoshi Ugi
Satoshi Ugi
SKSachiko Kaida
Sachiko Kaida
MTMasaji Tani
Masaji Tani