Yu Aoyama

Yu Aoyama

Department of Urology, Akita University Graduate School of Medicine, Akita, Japan

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

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

Representative Publications

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1 September 2023 in Current Oncology
Verified
Journal Article
Open access
PDF file
KNKazuyuki Numakura
Kazuyuki Numakura
MKMizuki Kobayashi
Mizuki Kobayashi
YMYumina Muto
Yumina Muto
HSHiromi Sato
Hiromi Sato
YSYuya Sekine
Yuya Sekine
THTomonori Habuchi
Tomonori Habuchi
A recent approach to radiotherapy for prostate cancer is the administration of high doses of radiation to the prostate while minimizing the risk of side effects. Thus, image-guided radiotherapy utilizes advanced imaging techniques and is a feasible strategy for increasing the radiation dose. New radioactive particles are another approach to achieving high doses and safe procedures. Prostate brachytherapy is currently considered as a combination therapy. Spacers are useful to protect adjacent organs, specifically the rectum, from excessive radiation exposure.

10 July 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
KNKazuyuki Numakura
Kazuyuki Numakura
MKMizuki Kobayashi
Mizuki Kobayashi
YMYumina Muto
Yumina Muto
HSHiromi Sato
Hiromi Sato
YSYuya Sekine
Yuya Sekine
THTomonori Habuchi
Tomonori Habuchi
A recent approach to radiotherapy for prostate cancer is the administration of high doses of radiation to the prostate while minimizing the risk of side effects. Thus, image-guided radiotherapy utilizes advanced imaging techniques and is a feasible strategy for increasing the radiation dose. New radioactive particles are another approach to achieving high doses and safe procedures. Prostate brachytherapy is currently considered as a combination therapy. Spacers are useful to protect adjacent organs, specifically the rectum, from excessive radiation exposure.

4 February 2026 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
RYRyohei Yamamoto
Ryohei Yamamoto
MSMitsuru Saito
Mitsuru Saito
SSSagehashi Sagehashi
Sagehashi Sagehashi
TMTomohiko Matsuura
Tomohiko Matsuura
SHShingo Hatakeyama
Shingo Hatakeyama
THTomonori Habuchi
Tomonori Habuchi
Background: Obesity is increasingly prevalent among kidney transplant candidates; however, its impact on graft outcomes in Asian populations is not well characterized. We evaluated the association between preoperative obesity and living-donor kidney transplantation outcomes in Japan. Methods: We analyzed 623 living-donor kidney transplants performed from 1998 to 2021 at six centers in northern Japan. Recipients were categorized by body mass index (BMI) at transplant, and multivariable Cox regression was employed for assessing graft outcomes. Results: Obesity (BMI, ≥30 kg/m2; n = 27 [4.3%]) was the strongest graft failure predictor (hazard ratio, 4.62) compared with normal-weight recipients. Moreover, overweight status (BMI, 25–29.9 kg/m2), acute rejection, and older donor age were independent risk factors. Despite similar rejection rates across the BMI groups, recipients with obesity exhibited persistently impaired kidney function from 1-week posttransplant to the 5-year follow-up. Patient survival was comparable across BMI groups; however, underweight status (BMI < 18.5 kg/m2) was associated with higher mortality. Conclusions: Preoperative obesity and overweight status were significant risk factors for graft failure in Japanese living-donor kidney transplant recipients. Meanwhile, the mortality rate was significantly higher in the patients with underweight status at transplant. Pre-transplant weight optimization and shared decision-making with candidates warrant consideration.

Verified
Journal Article
Open access
PDF file
TSTakuro Saito
Takuro Saito
MSMitsuru Saito
Mitsuru Saito
RYRyohei Yamamoto
Ryohei Yamamoto
SSSagehashi Sagehashi
Sagehashi Sagehashi
YAYu Aoyama
Yu Aoyama
THTomonori Habuchi
Tomonori Habuchi
Chronic allograft dysfunction, driven by interstitial fibrosis and tubular atrophy, remains a major cause of long-term renal allograft loss. Everolimus (EVR), a mammalian target of rapamycin (mTOR) inhibitor, may reduce fibrosis through antifibrotic effects and calcineurin inhibitor minimization. This study aimed to evaluate the impact of EVR-involving immunosuppression on renal allograft fibrosis and to identify predictors of fibrotic progression. A total of 104 living-donor kidney transplant recipients transplanted between 2011 and 2017 were retrospectively analyzed (EVR, n = 61; non-EVR, n = 43). Interstitial fibrosis was quantified in protocol biopsies using digital image analysis. Phosphorylation of the mTOR-signaling proteins p70 ribosomal S6 kinase and eukaryotic translation initiation factor 4E-binding protein 1 was assessed using a semiquantitative immunoreactive score. Multivariable regression analyses identified independent predictors of fibrotic progression. Cytomegalovirus infection was less frequent in the EVR group, whereas acute rejection, graft function, and graft survival were comparable between groups. At 1-year posttransplantation, interstitial fibrosis was significantly lower in the EVR group. EVR significantly suppressed p-4EBP1 phosphorylation and effectively modulated the mTOR-signaling pathway. Multivariable analysis identified the absence of EVR therapy as an independent predictor of accelerated fibrosis. EVR-involving immunosuppression attenuated renal interstitial fibrosis, likely through suppression of mTOR-signaling.