Faculty Profiles - MIZUNO, Masashi

Low-GDP, pH-neutral solutions preserve peritoneal endothelial glycocalyx during long-term peritoneal dialysis. Reviewed International coauthorship International journal

Naoya Sugiyama, Mitsuhiro Tawada, Ting Sun, Yasuhiro Suzuki, Hiroshi Kinashi, Makoto Yamaguchi, Takayuki Katsuno, Jan Aten, Carmen A Vlahu, Toin H van Kuppevelt, Yoshifumi Takei, Takuji Ishimoto, Shoichi Maruyama, Masashi Mizuno, Yasuhiko Ito

Clinical and experimental nephrology Vol. 25 ( 9 ) page： 1035 - 1046 2021.9

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: During peritoneal dialysis (PD), solute transport and ultrafiltration are mainly achieved by the peritoneal blood vasculature. Glycocalyx lies on the surface of endothelial cells and plays a role in vascular permeability. Low-glucose degradation product (GDP), pH-neutral PD solutions reportedly offer higher biocompatibility and lead to less peritoneal injury. However, the effects on the vasculature have not been clarified. METHODS: Peritoneal tissues from 11 patients treated with conventional acidic solutions (acidic group) and 11 patients treated with low-GDP, pH-neutral solutions (neutral group) were examined. Control tissues were acquired from 5 healthy donors of kidney transplants (control group). CD31 and ratio of luminal diameter to vessel diameter (L/V ratio) were evaluated to identify endothelial cells and vasculopathy, respectively. Immunostaining for heparan sulfate (HS) domains and Ulex europaeus agglutinin-1 (UEA-1) binding was performed to assess sulfated glycosaminoglycans and the fucose-containing sugar chain of glycocalyx. RESULTS: Compared with the acidic group, the neutral group showed higher CD31 positivity. L/V ratio was significantly higher in the neutral group, suggesting less progression of vasculopathy. Both HS expression and UEA-1 binding were higher in the neutral group, whereas HS expression was markedly more preserved than UEA-1 binding in the acidic group. In vessels with low L/V ratio, which were found only in the acidic group, HS expression and UEA-1 binding were diminished, suggesting a loss of glycocalyx. CONCLUSION: Peritoneal endothelial glycocalyx was more preserved in patients treated with low-GDP, pH-neutral solution. The use of low-GDP, pH-neutral solutions could help to protect peritoneal vascular structures and functions.

DOI： 10.1007/s10157-021-02078-9

生体腎移植術を安全に施行できた著明な血小板減少症を合併するEpstein症候群の一例

安田宜成, 岡崎雅樹, 菱田学, 田中章仁, 斎藤尚二, 加藤規利, 鈴木康弘, 小杉智規, 水野正司, 藤田高史, 加藤真史, 藤元昭一, 此元隆雄, 丸山彰一

移植 Vol. 56 ( 総会臨時 ) page： P1 - 50 2021.9

Vasculopathy plays an important role during the development and relapse of encapsulating peritoneal sclerosis with conventional peritoneal dialysis solutions. Reviewed International journal

Mitsuhiro Tawada, Yasuhiko Ito, Masataka Banshodani, Masahiro Yamashita, Sadanori Shintaku, Ting Sun, Yasuhiro Suzuki, Hiroshi Kinashi, Yoko Kubo, Masahiko Ando, Makoto Yamaguchi, Takayuki Katsuno, Masashi Mizuno, Hideki Kawanishi

Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association Vol. 36 ( 8 ) page： 1519 - 1526 2021.8

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Encapsulating peritoneal sclerosis (EPS) is an uncommon but life-threatening complication of peritoneal dialysis (PD) therapy. The causative factors of EPS remain unclear. Pathological studies of the peritoneum affected by EPS and relationships with clinical factors including PD solutions remain lacking. The objective of this study was to examine peritoneal samples from EPS patients and to identify the associations of peritoneal pathology with different clinical factors. METHODS: Peritoneal specimens were obtained at the time of surgical enterolysis in Tsuchiya General Hospital from 1993 to 2016. A total of 223 PD patients were enrolled and analyzed. Tissues were fixed with formalin and processed with hematoxylin and eosin and Masson's trichrome staining, as well as immunohistochemical staining for CD31 and CD68. RESULTS: Evaluations could be made in 174 patients who received surgical enterolysis. Conventional or pH-neutral low-glucose degradation product PD solutions were utilized during PD treatment. The conventional PD solution group showed less angiogenesis (P = 0.013) but more severe vasculopathy, in the form of a lower ratio of luminal diameter to vessel diameter (L/V ratio) (P < 0.001) in association with longer PD treatment. Multivariate Cox proportional hazard models revealed that L/V ratio (per 0.1 increase, hazard ratio = 0.88, 95% confidence interval 0.77-0.99, P = 0.047) was significantly associated with a lower incidence of EPS relapse. In contrast, most of the cases in the pH-neutral solution group showed milder vasculopathy. CONCLUSIONS: The pathology of EPS differed between conventional and pH-neutral solution groups. Vasculopathy was related to the development and relapse of EPS in the conventional solution group.

DOI： 10.1093/ndt/gfaa073

A case of temporary metastatic pulmonary calcification in a patient with hyperparathyroidism on peritoneal dialysis. Reviewed International journal

Kota Kawase, Kimiaki Takagi, Masashi Mizuno, Masanobu Horie

Clinical nephrology Vol. 95 ( 3 ) page： 161 - 165 2021.3

Language：English Publishing type：Research paper (scientific journal)

INTRODUCTION: Ectopic calcification is associated with secondary hyperparathyroidism (HPT) in patients with end-stage renal failure (ESRD). Metastatic pulmonary calcification (MPC) is another rare type of ectopic calcification, and there are a few reports on MPC in dialysis patients. CASE PRESENTATION: We report the case of a 52-year-old woman admitted with general fatigue and appetite loss, who was on peritoneal dialysis (PD) for 7 years. Although she was initially suspected of having secondary HPT due to ESRD, we finally diagnosed ectopic HPT that was caused by a cystic mass behind her thyroid gland overlapping with secondary HPT. We carefully observed her under conservative therapy because she refused surgery. On admission, she was diagnosed as having MPC because she had ground-glass-like opacification in her lung fields on high-resolution computed tomography scan, which was caused by a parathyroid tumor complicated by secondary HPT associated with ESRD. After she began intravenous injection of etelcalcetide hydrochloride, serum calcium, and intact parathyroid hormone (iPTH), values were adjusted, and the opacification disappeared. CONCLUSION: In a patient on PD, this is the first case of MPC that developed due to acute hypercalcemia, hyperphosphatemia, and dehydration and in which the ectopic pulmonary calcification clearly decreased with optimization of iPTH.

DOI： 10.5414/CN110337

Impact on survival of urgent dialysis initiation in patients with end-stage renal disease: a case-control study. Reviewed

腎障害への補体の関与 Invited

金恒秀, 水野正司

腎臓内科 Vol. 13 ( 3 ) page： 361 - 367 2021.3

Oral Antibiotics are Effective for Preventing Colonoscopy-associated Peritonitis as a Preemptive Therapy in Patients on Peritoneal Dialysis Reviewed International journal Open Access

Kojima Hiroshi, Kim Hangsoo, Kinashi Hiroshi, Katsuno Takayuki, Suzuki Yasuhiro, Mizuno Masashi, Sato Yuka, Ishimoto Takuji, Maruyama Shoichi, Ito Yasuhiko

Internal Medicine Vol. 60 ( 3 ) page： 353 - 356 2021

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：The Japanese Society of Internal Medicine

Objective In patients on peritoneal dialysis (PD), it was reported that colonoscopy, but not upper gastrointestinal endoscopy, could cause peritonitis as a complication. A guideline of the International Society for Peritoneal Dialysis recommends preemptive intravenous antibiotics administration of ampicillin and aminoglycoside with or without metronidazole, to prevent colonoscopy-associated peritonitis. In this study, we retrospectively evaluated the effects of preemptive antibiotics therapy by oral administration instead of intravenous administration. Methods We investigated the incidence of colonoscopy-associated peritonitis in a single center. In 170 patients undergoing PD between January 2010 and December 2019, 50 colonoscopies were performed, including 49 with oral administration of amoxicillin and ciprofloxacin and/or metronidazole as preemptive therapy 1 hour before the colonoscopy procedure, and 1 without. Results We observed no incidence of colonoscopy-associated peritonitis. Conclusion Generally, oral administration of preemptive antibiotics is less painful and more convenient than intravenous administration, especially in outpatient procedures, such as a colonoscopy. Our results suggest that oral antibiotic administration might be effective for preventing colonoscopy-associated peritonitis in PD patients.

DOI： 10.2169/internalmedicine.5092-20

Refractory Hypotension Caused by Selenium Deficiency in a Patient on Peritoneal Dialysis Reviewed International journal Open Access

Ryuge Akihiro, Kim Hangsoo, Suzuki Yasuhiro, Okazaki Masaki, Kojima Hiroshi, Saito Shoji, Kato Noritoshi, Ishimoto Takuji, Mizuno Masashi, Kosugi Tomoki, Maruyama Shoichi

Internal Medicine Vol. 60 ( 15 ) page： 2461 - 2464 2021

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：The Japanese Society of Internal Medicine

Selenium is essential for human health; its deficiency leads to cardiac dysfunction. We herein report a 79-year-old man on peritoneal dialysis who presented with refractory hypotension caused by selenium deficiency. He was admitted to our hospital with bacterial pneumonia and hypotension and abnormal electrocardiogram (ECG) findings. Despite improvement of pneumonia, his hypotension continued, and intravenous noradrenalin could not be discontinued. His serum selenium level was extremely low, and he was started on intravenous selenium. His hypotension and ECG findings gradually improved, and noradrenalin was discontinued. Physicians should consider selenium deficiency when patients on peritoneal dialysis show refractory hypotension.

DOI： 10.2169/internalmedicine.6632-20

Kimiaki Takagi, Masashi Mizuno, Kota Kawase, Kenichi Minoshima, Masayoshi Yamaha, Masanobu Horie

Clinical and experimental nephrology Vol. 24 ( 12 ) page： 1154 - 1161 2020.12

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Outcomes of patients with end-stage renal disease at urgent dialysis initiation are varied, but evidence of their long-term prognosis is limited. We aimed to characterize patients undergoing urgent dialysis initiation and analyse its effect on survival outcome. METHODS: We retrospectively identified 208 patients who began haemodialysis from 1 January 2012 to 31 December 2018 at our hospital. In this observational case-control study, the case group comprised patients starting urgent dialysis, and the control group comprised patients starting planned dialysis. We analysed laboratory data, sex, age, smoking history, comorbidities and presence of vascular access and nephrology care that potentially affected the outcome. Data were analysed with Kaplan-Meier curves of early and late period (3 years after dialysis initiation) survival and log-rank tests and with Cox regression analysis. RESULTS: Median age (range) at dialysis initiation was 73 (28-90) years, with 50 (24%) patients in the urgent initiation group. Five (10%) patients in this group had vascular access at dialysis initiation, whereas 21 (42%) had not received adequate pre-dialysis nephrology care. The estimated median overall survival rates of the urgent group and planned initiation group were 42 months and not reached, respectively (P = 0.0011). Multivariable analysis found urgent dialysis initiation to be an independent risk factor for survival (HR 2.36; 95% CI 1.36-4.00; P = 0.02). Survival was not significantly different between the groups for patients who continued chronic dialysis for > 3 years from dialysis initiation (P = 0.1339). CONCLUSION: The prognosis of patients starting dialysis in an urgent condition was poor compared with those who started planned dialysis.

DOI： 10.1007/s10157-020-01931-7