Yoko Nishimura
Hokkaido University
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Publication
Featured researches published by Yoko Nishimura.
The Journal of Urology | 2015
Kimihiko Moriya; Takahiko Mitsui; Takeya Kitta; Michiko Nakamura; Yukiko Kanno; Masafumi Kon; Yoko Nishimura; Nobuo Shinohara; Katsuya Nonomura
PURPOSE We retrospectively assessed the incidence of and risk factors for febrile urinary tract infection in children during active surveillance after early discontinuation of antibiotic prophylaxis. MATERIALS AND METHODS We retrospectively evaluated 9 females and 61 uncircumcised males diagnosed with primary vesicoureteral reflux before age 1 year who had persistent reflux on followup voiding cystourethrogram and were subsequently followed under active surveillance without continuous antibiotic prophylaxis. Patients with secondary vesicoureteral reflux or associated urological abnormality were excluded. Clinical outcomes, including incidence of febrile urinary tract infection and new scar formation, were evaluated. Risk factors for febrile urinary tract infection were also analyzed. RESULTS Mean age at stopping continuous antibiotic prophylaxis was 21 months, and mean followup was 61 months. During active surveillance 21 patients had febrile urinary tract infection, and the 5-year infection-free rate under active surveillance was 67.5%. One or 2 foci of minimal new scarring developed in 4 of 16 patients who underwent followup dimercapto-succinic acid scan after febrile urinary tract infection. On multivariate analysis dilated vesicoureteral reflux on followup voiding cystourethrogram was the only significant risk factor for febrile urinary tract infection. CONCLUSIONS This study revealed that about two-thirds of patients with persistent vesicoureteral reflux were free of febrile urinary tract infection during 5 years of active surveillance. Those with dilated vesicoureteral reflux on followup voiding cystourethrogram are at significantly greater risk for febrile urinary tract infection. Accordingly active surveillance, especially in patients with nondilated vesicoureteral reflux on followup voiding cystourethrogram, seems to be a safe option even in children who have not yet been toilet trained.
Urology | 2017
Yoko Nishimura; Kimihiko Moriya; Michiko Nakamura; Mutsumi Nishida; Megumi Sato; Yusuke Kudo; Satomi Omotehara; Takahito Iwai; Yamato Wakabayashi; Yukiko Kanno; Takeya Kitta; Masafumi Kon; Nobuo Shinohara
OBJECTIVE To clarify the prevalence and chronological changes of testicular microlithiasis in isolated congenital undescended testes, retrospective chart review was performed. MATERIALS AND METHODS Among children with palpable isolated undescended testes who underwent orchiopexy at less than 3 years of age between January 2009 and May 2016, those who had preoperative testicular ultrasonography were enrolled. Testicular microlithiasis was classified as limited or classic. RESULTS Sixty-five patients (54 unilateral undescended testes and 11 bilateral undescended testes) were enrolled. Preoperative evaluation demonstrated limited testicular microlithiasis in only 2 undescended testes in 2 patients (1 with unilateral undescended testes and 1 with bilateral undescended testes). Of these patients, 1 with unilateral undescended testes had limited testicular microlithiasis and the other with bilateral undescended testes had classic testicular microlithiasis after surgery. Among 53 unilateral undescended testes without microlithiasis preoperatively, limited and classic testicular microlithiasis was found in 1 and 6 testes, respectively, during follow-up. Testicular microlithiasis was identified in 2 on the contralateral descended testis of unilateral undescended testes postoperatively. Among 10 patients with bilateral undescended testes without microlithiasis preoperatively, limited testicular microlithiasis was detected in 4 during follow-up. Testicular microlithiasis was not diminished or resolved during follow-up. The overall prevalence of testicular microlithiasis in undescended testes (21.1%) was significantly higher than that in the contralateral descended testis in patients with unilateral undescended testes (3.7%) (P < .01). CONCLUSION Most testicular microlithiasis was identified postoperatively and never improved. The prevalence of testicular microlithiasis in isolated congenital undescended testes increased with time even if operated on early in life.
Journal of Ultrasound in Medicine | 2018
Kimihiko Moriya; Michiko Nakamura; Yoko Nishimura; Mutsumi Nishida; Yusuke Kudo; Yukiko Kanno; Takeya Kitta; Masafumi Kon; Nobuo Shinohara
To investigate the impact of preoperative ultrasonography (US) for detecting a viable testis in patients with a unilateral nonpalpable testis.
Urology | 2017
Kimihiko Moriya; Shota Yamamoto; Michiko Nakamura; Yoko Nishimura; Mutsumi Nishida; Takahito Iwai; Yukiko Kanno; Takeya Kitta; Nobuo Shinohara
Limited numbers of pediatric intratesticular cystic lesions have been reported. Although the majority of pediatric intratesticular cystic masses are benign, natural history of testicular cystic lesion in children has been rarely reported so far. We report a case of intratesticular cystic lesion in a prepubertal child who underwent testis sparing surgery after shrinkage during conservative follow-up. As an initial strategy for intratesticular cystic lesions in prepubertal children, observational approach with serial ultrasonographic evaluations may be a management of choice.
BJUI | 2017
Kimihiko Moriya; Michiko Nakamura; Yoko Nishimura; Yukiko Kanno; Takeya Kitta; Masafumi Kon; Nobuo Shinohara
To clarify the impact of endoscopic incision (EI) for ureterocele as an initial procedure, by performing a retrospective chart review, focusing on the prevalence of and risk factors for symptomatic urinary tract infection (UTI) after EI.
Journal of Pediatric Urology | 2016
Kimihiko Moriya; Michiko Nakamura; Yoko Nishimura; Takeya Kitta; Yukiko Kanno; Hiroki Chiba; Masafumi Kon; Nobuo Shinohara
INTRODUCTION Renal abnormality is not a rare finding in infants with primary VUR. The pathophysiology of the renal abnormality is considered to be congenital or acquired. Congenital hypo/dysplastic kidney is a common finding in infants with primary VUR, especially in boys. However, the long-term impact of unilateral hypo/dysplastic kidney has not been elucidated. The aim of the current study is to clarify the long-term impact of unilateral hypo/dysplastic kidney with primary vesicoureteral reflux diagnosed in infancy. MATERIAL AND METHODS The medical records of patients with primary VUR detected in infancy with unilateral hypo/dysplastic kidney on initial nuclear renal scan (<40% relative renal function) and no scar on the contralateral kidney were reviewed retrospectively. Among them, 29 patients who were followed for more than 5 years were included in this study. Their clinical outcomes including chronic kidney disease (CKD) stage using estimated glomerular filtration rate (GFR) and the incidences of hypertension and proteinuria were analyzed. RESULTS Mean age at final visit was 12.4 years (range 5.9-22.2). Estimated GFR was evaluated in 26 patients at a mean age of 12.0 years (5.9-22.2). CKD stage was 1 in all. According to the guidelines of the Japanese Society of Hypertension, while none exceeded the standard level of systolic blood pressure (BP), two patients slightly exceeded the standard level of diastolic BP. In addition, no significant proteinuria was detected in all patients, although microalbuminemia was detected in 7.7% of patients. DISCUSSION The prognosis of reflux nephropathy depends on the remnant renal tissue mass, that is, the number of normal nephrons. The normal congenital solitary kidney is reported to be hyperplastic with normal-sized glomeruli rather than hypertrophic ones with larger nephrons, and to have better long-term outcome regarding renal function. Accordingly, we speculated that patients with unilateral hypo/dysplastic kidney would have a similar number of nephrons to those without hypo/dysplastic kidney who have no or minimal scar as far as the contralateral kidney is well preserved. Long-term outcome of the current retrospective study was consistent with our speculation in terms of estimated GFR, proteinuria, or hypertension. CONCLUSIONS The present study demonstrated that significant clinical findings related to unilateral hypo/dysplastic kidney detected in infancy were rarely observed in the long term. Accordingly, unilateral hypo/dysplastic kidney seems to be a benign condition. To confirm this finding, further follow-up of these patients is necessary.
BMC Research Notes | 2017
Yoko Nishimura; Kimihiko Moriya; Michiko Nakamura; Takeya Kitta; Yukiko Kanno; Hiroki Chiba; Masafumi Kon; Nobuo Shinohara
World Journal of Urology | 2016
Kimihiko Moriya; Michiko Nakamura; Yoko Nishimura; Takeya Kitta; Yukiko Kanno; Hiroki Chiba; Masafumi Kon; Nobuo Shinohara
BMC Pediatrics | 2018
Michiko Nakamura; Kimihiko Moriya; Yoko Nishimura; Mutsumi Nishida; Yusuke Kudo; Yukiko Kanno; Takeya Kitta; Masafumi Kon; Nobuo Shinohara
The Journal of Urology | 2016
Kimihiko Moriya; Michiko Nakamura; Yoko Nishimura; Takeya Kitta; Kanno Yukiko; Hiroki Chiba; Masafumi Kon; Nobuo Shinohara