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Dive into the research topics where Naoto Nishizaki is active.

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Featured researches published by Naoto Nishizaki.


Pediatrics International | 2009

Can cranberry juice be a substitute for cefaclor prophylaxis in children with vesicoureteral reflux

Naoto Nishizaki; Tomonosuke Someya; Daishi Hirano; Shuichiro Fujinaga; Yoshiyuki Ohtomo; Toshiaki Shimizu; Kazunari Kaneko

Urinary tract infection (UTI) is a common childhood infection. In 30–50% of children with UTI the infections occur recurrently, especially in those with vesicoureteral reflux (VUR), resulting in hospitalizations, and long-term health problems, such as renal scars, hypertension, and end-stage renal disease. To reduce the likelihood of recurrent UTI for children with VUR, antibiotics prophylaxis has been regarded as the therapeutic standard for many years. However, the disadvantage of long-term antibiotic therapy is the potential for development of resistant organisms in the host. Although cranberry juice prophylaxis was found to reduce the frequency of bacteriuria with pyuria in older women, no studies have yet been reported in the literature on children with VUR. The purpose of this study was to examine whether cranberry juice can be substituted for antibiotic prophylaxis in the prevention of UTI in children with VUR.


Pediatric Nephrology | 2010

Low-dose pulse methylprednisolone followed by short-term combination therapy and tonsillectomy for childhood IgA nephropathy

Shuichiro Fujinaga; Yoshiyuki Ohtomo; Daishi Hirano; Naoto Nishizaki; Tomonosuke Someya; Yoshikazu Ohtsuka; Kazunari Kaneko; Toshiaki Shimizu

Sirs, We read with great interest the article by Yata et al. concerning the long-term outcome in Japanese children with immunoglobulin (Ig)A nephropathy [1]. These authors found a marked improvement in renal survival since the 2-year combination therapeutic regimen of prednisolone and immunosuppressive agent was first introduced for Japanese children with severe IgA nephropathy [2]; simultaneously, adverse effects, such as growth retardation and aseptic necrosis of the femur, associated with the longterm administration of steroids, were also observed with this combination therapy [2]. Alternatively, Pozzi et al. reported the impressive benefits of treatment with pulse methylprednisolone and short-term prednisolone (6 months) with respect to reducing proteinuria and preventing endstage renal failure in adult patients—without considerable toxicity [3]. Hotta et al. showed that tonsillectomy combined with low-dose pulse methylprednisolone followed by short-term oral prednisolone (12 months), which is regarded as the standard treatment of adulthood IgA nephropathy in Japan, was effective in resolving urinary abnormalities in Japanese adult patients, especially during the earlier course of the disease [4, 5]. We report here the findings of a cohort patients with IgA nephropathy who were treated with low-dose pulse methylprednisolone followed by short-term combination therapy with (n=5) or without tonsillectomy (n=5). Ten consecutive patients (six boys, four girls) with newly biopsy-proven IgA nephropathy and urinary protein excretion of more than 0.5 g/m daily who had been referred to Saitama Children’s Medical Center between 2003 and 2006 were enrolled into the study. Their age at the start of therapy ranged between 6.3 and 14.7 years (mean 10.5 years). The mean urinary protein excretion was 1.2 g/m per day (range 0.5–2.1 g/m per day). The mean percentage of glomeruli showing crescents and segmental sclerosis on renal biopsy in the patients was 32 and 6%, respectively. The treatment regimen consisted of low-dose pulse methylprednisolone (intravenously 15–20 mg/kg/day; maximum 600 mg/day) for three consecutive days weekly for 3 weeks, followed by short-term combination therapy (approximately 12 months) of alternate-day prednisolone (initially 1 mg/kg; maximum 30 mg), mizoribine (5 mg/kg per day)/azathioprine (2 mg/kg per day), and dipyridamole (5 mg/kg per day). The oral prednisolone dosages were tapered off at a dose of 2.5–5 mg every 4–8 weeks on the basis of the reduction in urinary protein excretion. Beginning in 2006, tonsillectomy was additionally performed within 3 months after the initiation of pulse methylprednisolone therapy in five patients. The primary endpoint was the disappearance of protein excretion defined as a morning urinary protein-to-creatinine ratio (mg/ mg) <0.1. The interval between the initial presentation Pediatr Nephrol (2010) 25:563–564 DOI 10.1007/s00467-009-1239-1


Pediatric Research | 2015

Evaluation of kidney dysfunction and angiotensinogen as an early novel biomarker of intrauterine growth restricted offspring rats

Yayoi Murano; Naoto Nishizaki; Amane Endo; Naho Ikeda; Tomonosuke Someya; Mayu Nakagawa; Taichi Hara; Koji Sakuraya; Satoshi Hara; Daishi Hirano; Mitsuyoshi Suzuki; Hiromichi Shoji; Shuichiro Fujinaga; Yoshiyuki Ohtomo; Toshiaki Shimizu

Background:Few studies have addressed the growing concerns of chronic kidney diseases in children with intrauterine growth restriction (IUGR). Therefore, the purpose of this study was to evaluate long-term kidney dysfunction and determine if urinary angiotensinogen (AGT) was suitable as a novel early biomarker for kidney dysfunction in IUGR offspring.Methods:Pregnant rats underwent bilateral uterine artery ligation, and as a control group, sham surgeries were performed.Results:The birth weight was reduced, the urinary AGT to creatinine ratio was significantly higher at week 20, and urinary protein levels were significantly higher at week 32 in IUGR rats than in control rats. On the other hand, the histological findings at week 32 revealed long-term kidney dysfunction, more severe glomerulosclerosis, and greater glomerular diameters in IUGR rats. Moreover, AGT mRNA expression and immunohistological staining were significantly increased in IUGR rats; this suggests that the intrarenal renin–angiotensin system (RAS) contributes to renal dysfunction of IUGR offspring.Conclusion:Urinary AGT elevation prior to urinary protein levels suggests that AGT is an early biomarker. At week 32, kidney dysfunction was severe in IUGR rats and intrarenal RAS appeared to be one of the causes.


Pediatric Nephrology | 2011

Early identification of steroid dependency in Japanese children with steroid-sensitive nephrotic syndrome undergoing short-term initial steroid therapy

Shuichiro Fujinaga; Daishi Hirano; Naoto Nishizaki

Sirs,We read with great interest the article titled “Early age atdebut is a predictor of steroid-dependent and frequentrelapsing nephrotic syndrome” by Andersen et al. recentlypublished in Pediatric Nephrology [1]. In a retrospectiveanalysis of 54 children (approximately 80% Caucasian)with steroid-sensitive nephrotic syndrome (SSNS), theauthors concluded that young age at presentation and malegender were associated with a high risk of steroiddependency despite prolongation of the steroid course atthe debut of SSNS. In addition, they found a reduction inrelapse frequency in the long-term initial steroid therapygroup (12 weeks) compared with the short-term group(8 weeks).Here, based on our retrospective analysis, we would liketo add to the list of predictive risk factors for steroiddependency with short-term initial steroid therapy inJapanese children with SSNS. Between January 1999 andJune 2007, 72 consecutive patients (51 male, 21 female)with recent-onset SSNS and treated at the Saitama Child-ren’s Medical Center were enrolled in this study. Thesepatients were treated with a short-term steroid treatmentregimen (total 8 weeks) comprising 4 weeks of dailyprednisolone treatment (2 mg/kg or 60 mg/m


Pediatric Nephrology | 2009

Relapsing peritonitis with Corynebacterium aquaticum in a boy receiving automated peritoneal dialysis

Shuichiro Fujinaga; Yoshiyuki Ohtomo; Daishi Hirano; Naoto Nishizaki; Tomonosuke Someya; Yoshikazu Ohtsuka; Kazunari Kaneko; Toshiaki Shimizu

Sirs, Corynebacterium species, with the exception of C. diphtheriae, are commonly regarded as contaminants when isolated from clinical specimens because they belong to the normal flora of the human skin and mucous membranes [1]. In immunocompromised patients, however, this organism has been identified as a human pathogen. Corynebacterium aquaticum is an environmental organism, with its natural habitat in fresh water [2]. It has been reported in association with neonatal meningitis and urinary tract infection, septicemia in an elderly patient with diabetes and septic shock in an human immunodeficiency virus (HIV)-infected patient [3–6]. To date, C. aquaticum peritonitis has been reported in only three continuous ambulatory peritoneal dialysis (CAPD) adult patients [7–9]. Here, we describe a boy with relapsing peritonitis caused by C. aquaticum who had received automated peritoneal dialysis (APD). A 17-year-old boy with end stage renal disease due to bilateral hypoplastic kidneys, who had received APD since August 2004, was admitted to our hospital in May 2008 because of persistent fever, abdominal pain and a cloudy peritoneal effluent. His dialysis regimen consisted of six 2.5-L exchanges on the cycler (Baxter Homechoice cycler) for a period of 8 h per night. There was no evidence of immunosuppression in the patient, except for the presence of the PD catheter. Physical examination revealed a temperature of 38.6°C, normal bowel sounds and slight abdominal tenderness, without guarding or rebound. There was no infection at the exit site and tunnel of the peritoneal catheter. A peritoneal fluid analysis showed a total nucleated cell count of 19,300/mm with 50% polymorphonucleated cells. Investigations revealed a peripheral blood white cell count of 8500/mm and a C-reactive protein level of 2.18 mg/dL. Two sets of blood cultures were negative. After dialysate samples of 10 ml were inoculated into both aerobic and anaerobic blood culture vials, the patient was empirically treated with intraperitoneal cefazolin (1 g per day) and ceftazidime (1 g per day). The symptoms and signs subsided, and the peritoneal fluid cleared within 5 days. On the third hospital day, Staphylococcus epidermidis was identified in the dialysate cultures; as this strain was sensitive to all tested antibiotics, including cefazolin, the ceftazidime was discontinued. Despite the treatment with intraperitoneal cefazolin, the patient developed fever and abdominal pain again on day 11. Cultures of the dialysate again resulted in the growth of an aerobic, gram-positive rod. The isolated strain was biotyped using an API Coryne kit (bioMerieux, Japan) and was identified as Corynebacterium aquaticum on day 20. This strain was resistant to cefazolin and ceftazidime, but susceptible to vancomycin: The minimum inhibition concentrations (MICs) were 50 mcg/ml for cefazolin, <100mcg/ml for ceftazidime and 3.13 mcg/ml for vancomycin. Based on the antibiotic susceptibility, cefazolin was stopped and vancoPediatr Nephrol (2009) 24:1253–1254 DOI 10.1007/s00467-008-1059-8


Clinical Pediatrics | 2013

Nephronophthisis Cannot Be Detected by Urinary Screening Program

Daishi Hirano; Shuichiro Fujinaga; Yoshiyuki Ohtomo; Naoto Nishizaki; Satoshi Hara; Hitohiko Murakami; Yutaka Yamaguchi; Motoshi Hattori; Hiroyuki Ida

Nephronophthisis (NPHP) is an autosomal recessive cystic kidney disease and is the most frequent genetic cause for end-stage renal disease (ESRD) in Western countries. In contrast, the actual incidence of NPHP in Japan remains unclear because details of only about 30 Japanese patients have been reported so far. Till date, mutations in 9 NPHP genes (NPHP1-9) have been identified in NPHP subtypes 1 to 9. The first identified NPHP gene NPHP1, which is localized on chromosome 2q13, encodes nephrocystin. Based on the timing for ESRD, the following 3 clinical variants have been described: infantile, juvenile, and adolescent. Of these, juvenile NPHP (NPHP1) is the most common form, which accounts for 5% to 10% of ESRD cases in Caucasian children. To our knowledge, only 2 previous studies have reported on Japanese patients with NPHP in whom genetic diagnosis was made. Here, we report on a girl with NPHP1 who initially visited a local hospital because of general fatigue and was referred to our hospital as she demonstrated anemia associated with chronic renal insufficiency. However, no abnormal findings had been noted during annual school urinary screenings conducted over a long period of time.


Clinical Nephrology | 2012

Hereditary renal hypouricemia: a cause of calcium oxalate urolithiasis in a young female.

Naoto Nishizaki; Shuichiro Fujinaga; Daishi Hirano; Hiroaki Kanai; Hitoshi Kaya; Yoshiyuki Ohtomo; Toshiaki Shimizu; Kandai Nozu; Kazunari Kaneko

Although renal hypouricemia is mostly asymptomatic, it is known to present a high risk of exercise-induced acute renal failure, especially in young males. However, there is little information regarding the clinical features of urolithiasis as a complication in childhood renal hypouricemia. Here we report a 4-year old female with idiopathic renal hypouricemia who presented with macroscopic hematuria due to obstructive calcium oxalate urolithiasis. She was treated successfully with percutaneous nephrolithotripsy and thereafter hematuria disappeared. Sequence analysis of the patient and her familys URAT1 gene confirmed a nonsense mutation in exon 4 (W258X). To the best of our knowledge, this is the youngest case of hereditary renal hypouricemia caused by URAT1 gene mutation, which was found by hematuria due to calcium oxalate urolithiasis.


Pediatrics International | 2016

Effect of PMX‐DHP for sepsis due to ESBL‐producing E. coli in an extremely low‐birthweight infant

Naoto Nishizaki; Mayu Nakagawa; Satoshi Hara; Hisayuki Oda; Masato Kantake; Kaoru Obinata; Yuki Uehara; Keiichi Hiramatsu; Toshiaki Shimizu

We report a case of early onset sepsis caused by (CTX for cefotaximase and M for Munich)‐type extended‐spectrum β‐lactamase‐producing Escherichia coli (ESBL E. coli) in a preterm infant weighing 601 g. He was given meropenem and treated for endotoxin absorption with polymyxin B‐immobilized fibers with only 8 mL of priming volume. The patient survived without any short‐term neurological or respiratory sequelae. The choice of antibiotics is particularly important in seriously ill neonates with sepsis due to ESBL‐producing organisms. Polymyxin B hemoperfusion might be an innovative therapy for severe neonatal sepsis and could improve outcome even in an extremely low‐birthweight infant.


Clinical Nephrology | 2013

Role of ultrasound in revealing complications following percutaneous renal biopsy in children.

Daishi Hirano; Shuichiro Fujinaga; Naoto Nishizaki; Hiroaki Kanai; Hiroyuki Ida

BACKGROUND This retrospective case series aimed to investigate the role of ultrasound immediately post-percutaneous renal biopsy (PRB) for detecting post-biopsy complications in pediatric patients. METHODS Data from 380 (male/female = 209/171) consecutive biopsies of native kidney tissue of 344 children from January 2001 to October 2009 were analyzed to investigate the role of an ultrasound immediately post-PRB and the predictive value of demographic, clinical, and baseline chemistry factors in predicting the risk of post-PRB complications. RESULTS Post-PRB ultrasound identified hematoma formation in 33 (8.7%) patients. Of the 19 (5.0%) patients whose hematomas were large (≥ 1 cm), post-biopsy courses of 16 patients were clinically complicated. On the other hand, of the 14 patients whose hematomas were small (< 1 cm), all patients but one showed an uncomplicated clinical course. Of the 17 complications, 79.1% were detected within the first 24 hours and 21.9% (cases of resorption fever) between 24 and 144 hours post-PRB. Age ≥ 10 is an independent risk factor for post-PRB complication. CONCLUSIONS Age ≥ 10 is an independent risk factor for post-PRB complication. After the procedure, the formation of a large hematoma predicted a complicated clinical course.


Pediatrics International | 2012

Use of fibrin glue in the treatment of pneumothorax in premature infant

Naoto Nishizaki; Hiroki Suganuma; Satoru Nagata; Toshiaki Shimizu

1 Levine MA. Clinical spectrum and pathogenesis of pseudohypoparathyroidism. Rev. Endocr. Metab. Disord. 2000; 1: 265–74. 2 Diaz R. Calcium disorders in children and adolescents. In: Lifshits F (ed.). Pediatric Endocrinology, 5th edn. Informa Healthcare USA, New York, 2007; 475–95. 3 Doyle DA. Disorders of the parathyroid. In: Kliegman RM, Stanton BF, St Geme JW, Schor NF, Behrman RE (eds). Saunders, Philadelphia, PA, 2011; 1916–23. 4 Igarahishi T, Kawato H, Kamoshita S. Reversible low-molecularweight proteinuria in patients with distal renal tubular acidosis. Pediatr. Nephrol. 1990; 4: 593–6. 5 Watanabe T. Proximal renal tubular dysfunction in primary distal renal tubular acidosis. Pediatr. Nephrol. 2005; 20: 86–8. 6 Rocher LL, Tannen RL. The clinical spectrum of renal tubular acidosis. Ann. Rev. Med. 1986; 37: 319–31. 7 Sreedharan R, Avner ED. Renal tubular acidosis. In: Kliegman RM, Stanton BF, St Geme JW, Schor NF, Behrman RE (eds). Saunders, Philadelphia, PA, 2011; 1808–11. 8 Hein G, Richer D, Manz F, Weitzel D, Kalhoff H. Development of nephrocalcinosis in very low birth weight infants. Pediatr. Nephrol. 2004; 19: 616–20. 9 Igarashi T, Sekine Y, Kawato H, Kamoshita S, Saigusa Y. Transient neonatal distal renal tubular acidosis with secondary hyperparathyroidism. Pediatr. Nephrol. 1992; 6: 267–9. 10 Bank N, Aynediian HS. A micropuncture study of the effect of parathyroid hormone on renal bicarbonate reabsorption. J. Clin. Invest. 1976; 58: 336–44. 11 Koo WWK. Neonatal calcium, magnesium, and phosphorus disorders. In: Lifshits F (ed.). Informa Healthcare USA, New York, 2007; 499–529. 12 Heath DA, Shaw NJ. Disorders of calcium and bone metabolism. In: Brook CGD, Hindmarsh PC (eds). Blackwell Science, Oxford, 2001; 390–410. 13 Marx SJ, Hershman JM, Aurbach GD. Thyroid dysfunction in pseudohypoparathyroidism. J. Clin. Endocrinol. Metab. 1971; 33: 822–8. 14 Gonzalez BP, Longas AF, Oyarzabal M, Nosas R. The effects of growth hormone deficiency and growth hormone replacement therapy on intellectual ability, personality and adjustment in children. Pediatr. Endocrinol. Rev. 2010; 7: 328–38.

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Daishi Hirano

Jikei University School of Medicine

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Kazunari Kaneko

Kansai Medical University

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