Keiji Hirai

Dr. Keiji Hirai

Jichi Medical University Saitama Medical Center
orcid

Research Focus & Metrics

Academic Career Length

32Years (1995-Present)

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

Representative Publications

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26 April 2016 in Nephro-Urology Monthly
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Journal Article
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KHKeiji Hirai
Keiji Hirai
SOSusumu Ookawara
Susumu Ookawara
Yoshiyuki MorishitaYoshiyuki Morishita
Yoshiyuki Morishita
Sarcopenia and physical inactivity synergistically progress in patients with chronic kidney disease (CKD) and are strong predictors of mortality in this population. Exercise training and essential amino acids and vitamin D supplements may contribute to improving sarcopenia and physical inactivity in CKD patients. Keywords: Sarcopenia; Physical Inactivity; Chronic Kidney Disease

18 October 2020 in Journal of Clinical Medicine
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Journal Article
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KHKeiji Hirai
Keiji Hirai
SIShigeki Imamura
Shigeki Imamura
AHAizan Hirai
Aizan Hirai
SOSusumu Ookawara
Susumu Ookawara
Yoshiyuki MorishitaYoshiyuki Morishita
Yoshiyuki Morishita
This study investigated the effects of evolocumab on vulnerable coronary plaques and factors associated with the change in stability and size of plaques in patients taking statins. Vulnerable coronary plaques were defined using coronary computed tomography (CT) angiography as having a density of <50 HU within the region of interest and a remodeling index ≥1.1. The changes in minimum CT density, remodeling index, and percent stenosis of vulnerable coronary plaques after six months of evolocumab administration were retrospectively analyzed in 136 vulnerable coronary plaques from 98 patients (68 men and 30 women; mean age: 72.9 ± 8.7 years) treated with a statin. The administration of evolocumab significantly increased the minimum CT density (39.1 ± 8.1 HU to 84.9 ± 31.4 HU, p < 0.001), reduced the remodeling index (1.29 ± 0.11 to 1.19 ± 0.10, p < 0.001), and decreased the percent stenosis (27.0 ± 10.4% to 21.2 ± 9.8%, p < 0.001). Multiple linear regression analysis revealed that baseline percent stenosis (standard coefficient (β) = −0.391, p = 0.002) independently correlated with the change in minimum CT density, whereas the baseline remodeling index (β = −0.368, p < 0.001) independently correlated with a change in the remodeling index. Evolocumab stabilized vulnerable coronary plaques and reduced their size. These results suggest that evolocumab protects against coronary artery disease progression in patients taking statins.

1 November 2023 in Drug Design, Development and Therapy
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Journal Article
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KYKatsunori Yanai
Katsunori Yanai
KHKeiji Hirai
Keiji Hirai
SKShohei Kaneko
Shohei Kaneko
YMYuko Mutsuyoshi
Yuko Mutsuyoshi
TKTaisuke Kitano
Taisuke Kitano
YMYoshiyuki Morishita
Yoshiyuki Morishita
Objective: We investigated the efficacy and safety of dotinurad, a selective urate reabsorption inhibitor, in hyperuricemic patients with advanced chronic kidney disease (CKD) (stage G3-5). Patients and Methods: We retrospectively analyzed the cases of 34 patients (mean age, 68.6 ± 13.3 years; 17 men and 17 women) after 12 months of dotinurad treatment based on the changes in uric acid (UA) and the urine protein-to-creatinine ratio (UPCR) plus the annual change in estimated glomerular filtration rate (eGFR). Hyperuricemia (UA ≥ 6.0 mg/dL) and advanced CKD (mean eGFR: 32.0 ± 13.3 mL/min/1.73m2; stage G3, n=17; G4, n=13; G5, n=4) were present in all of the patients. The cases of 34 matched individuals with similar propensity scores (who were not taking dotinurad) were analyzed as a control group. Results: UA values decreased significantly in the dotinurad group (7.1 ± 0.8 mg/dL to 5.9 ± 1.0 mg/dL, p< 0.05) but those did not change in the control group. UPCR did not change in either group. Low-density lipoprotein cholesterol also decreased significantly in the dotinurad group (98.8 ± 43.4 mg/dL to 82.9 ± 33.1 mg/dL, p< 0.05). With the 12-month dotinurad treatment, the annual change in the patients’ eGFR was significantly improved from − 6.0 ± 12.9 mL/min/1.73 m2/year to − 0.9 ± 4.6 mL/min/1.73 m2/year (p< 0.05), but there was no change in the control group. Conclusion: Dotinurad can decrease UA levels and might attenuate renal function decline in individuals with hyperuricemia and advanced CKD.

1 January 1997 in Journal of Chemotherapy
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Journal Article
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Takahiro YamasakiTakahiro Yamasaki
Takahiro Yamasaki
TIT. Ichimiya
T. Ichimiya
KHKeiji Hirai
Keiji Hirai
KHK. Hiramatsu
K. Hiramatsu
MNM. Nasu
M. Nasu
The effect of subminimal inhibitory concentrations (sub-MICs) of antimicrobial agents on the adherence of Pseudomonas aeruginosa (pili+) to trachea mucosal cells, the first stage in the development of P. aeruginosa respiratory tract infections, was investigated. The adherence of P. aeruginosa to the cells of the lower respiratory tract using a model of acid-injured trachea in mice was observed by electron microscopy (transmission and scanning). When P. aeruginosa was cultured with 1/4 MIC of erythromycin, minocycline, clindamycin, ofloxacin or tobramycin at 37°C for 4 hours, the number of pili was significantly reduced (P<0.01), together with a significant reduction in the number of adherent bacteria at 1/4 MIC of erythromycin (P<0.01). No suppressive effects of piperacillin or ceftazidime were obtained on the piliation and adhesion of P. aeruginosa. These findings indicate that sub-MICs of erythromycin reduce the adherence of P. aeruginosa to the tracheal mucosa, which may prevent the onset of P. aeruginosa respiratory tract infection.

7 July 2021 in Frontiers in Medicine
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Journal Article
Open access
KHKeiji Hirai
Keiji Hirai
HNHiroaki Nonaka
Hiroaki Nonaka
MUMoeka Ueda
Moeka Ueda
JMJunki Morino
Junki Morino
SKShohei Kaneko
Shohei Kaneko
Yoshiyuki MorishitaYoshiyuki Morishita
Yoshiyuki Morishita
Background: We investigated the effects of roxadustat on the anemia, iron metabolism, peritoneal membrane function, and residual renal function; and determined the factors associated with the administration of roxadustat in patients who were undergoing peritoneal dialysis.Methods: We retrospectively analyzed the changes in hemoglobin, serum ferritin, transferrin saturation (TSAT), 4-h dialysate/plasma creatinine, and renal weekly urea clearance over the 24 weeks following the change from an erythropoiesis-stimulating agent (ESA) to roxadustat in 16 patients who were undergoing peritoneal dialysis and had anemia (Roxadustat group). Twenty-three peritoneal dialysis patients who had anemia and continued ESA served as a control group (ESA group).Results: There were no significant differences in hemoglobin, serum ferritin, TSAT, 4-h dialysate/plasma creatinine, or renal weekly urea clearance between the two groups at baseline. The hemoglobin concentration was significantly higher in the Roxadustat group than in the ESA group after 24 weeks (11.6 ± 1.0 g/dL vs. 10.3 ± 1.1 g/dL, p < 0.05), whereas the ferritin concentration and TSAT were significantly lower (139.5 ± 102.0 ng/mL vs. 209.2 ± 113.1 ng/mL, p < 0.05; and 28.1 ± 11.5% vs. 44.8 ± 10.4%, p < 0.05, respectively). The changes in 4-h dialysate/plasma creatinine and renal weekly urea clearance did not differ between the two groups. Linear regression analysis revealed that the serum potassium concentration correlated with the dose of roxadustat at 24 weeks (standard coefficient = 0.580, p = 0.019).Conclusion: Roxadustat may improve the anemia and reduce the serum ferritin and TSAT of the peritoneal dialysis patients after they were switched from an ESA, without association with peritoneal membrane function or residual renal function.

1 March 2016 in ASAIO Journal
Verified
Journal Article
Closed access
SOSusumu Ookawara
Susumu Ookawara
HMHaruhisa Miyazawa
Haruhisa Miyazawa
KIKiyonori Ito
Kiyonori Ito
YUYuichiro Ueda
Yuichiro Ueda
YKYoshio Kaku
Yoshio Kaku
KTKaoru Tabei
Kaoru Tabei
Intradialytic exercise-induced blood volume (BV) reduction may cause intradialytic hypotension in hemodialysis (HD) patients. However, BV recovery time after intradialytic exercise remains unknown. Hemodialysis patients were recruited, and their relative BV change (%ΔBV) were measured with intradialytic exercise (n = 12). After confirming the linearity of %ΔBV for 30 min, patients exercised using a stationary cycle in the supine position. The target exercise intensity was a 10% increase in heart rate (HR), corresponding to relatively low-intensity exercise. Baseline %ΔBV (assumed baseline) were calculated for the 30 min before exercise using linear regression analysis. The mean intradialytic exercise start and end times after HD initiation were 93.0 ± 8.4 and 116.4 ± 8.3 min, respectively, a mean exercise duration of 23.5 ± 2.6 min. Percentage change in blood volume declined rapidly upon exercise initiation and gradually increased above the assumed baseline throughout HD. At the end of HD, %ΔBV in the exercise group was significantly higher than the assumed baseline (measured - assumed baseline %ΔBV: 2.17 ± 0.62%; p = 0.02). Intradialytic exercise with low intensity in the supine position attenuated ultrafiltration-induced BV reduction at the end of HD. Therefore, intradialytic exercise may prevent intradialytic hypotension during later HD, although its intensity was relatively low level.