• Childhood Kidney Diseases
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• v.5 no.1
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• pp.43-50
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• 2001

Purpose : The urinary tract infection associated with vesicoureteral reflux(VUR) in children may result in serious complications such as renal scarring, hypertension, proteinuria and end stage renal disease. The purpose of this study was to evaluate the factors affecting renal scar such as age, gender, grade of VUR, and ACE gene polymorphism, and body growth in the patients with and those without renal scar associated with VUR Methods : During the period from January 1994 to July 2000, We had 93 children with urinary tract infection associated with VUR who were admitted to the Department of pediatrics of Chonbuk National University Hospital. The patients were divided into two groups according to follow up 99mTc-DMSA renal scan; patients with renal scar group and those with non-scar group. We analyzed and compared the factors associated with renal scarring between the two groups. Results : There were no significant difference in gender, causative organism, ACE gene polymorphism, height and weight at diagnosis between renal scar group and non-scar group. Fifty four patients were in renal scar group and forty seven of them had VUR. The age at diagnosis was significantly higher in renal scar group (2.48${\pm}$2.64yr) than in non renal scar group (1.26${\pm}$1.83yr). Especially, the infants who were less than 1 year of age with VUR developed relatively more renal scar compared with infants older than 1 tear of age. The incidence of renal scarring showed a direct correlation with the severity of VUR. Conclusion : The factors affecting renal scar formation were age at diagnosis, presence and grade of VUR, but the other factors such as gender, causative organism, ACE gene polymorphism were not associated with renal scarring. Therefore, further evaluation about uropathogenic E coli and foflow up study about body growth associated with severity of renal scar would be necessary. (J. Korean Soc Pediatr Nephrol 5 : 43- 50, 2001)

• Clinical and Experimental Pediatrics
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• v.48 no.9
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• pp.998-1003
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• 2005

Purpose : We evaluated the occurrence of renal scarring in children with unilateral vesicoureteral reflux(VUR), and the relationships between renal scar formation and risk factors such as VUR, duration of fever, acute-phase reactant, age, and sex. Methods : We retrospectively analyzed the data of 35 children newly diagnosed with unilateral vesicoureteral reflux after urinary tract infection(UTI) in Wallace Memorial Baptist Hospital between January 1996 and December 2004. Ultrasonography, Erythrocyte sedimentation rate(ESR), and C-reactive protein(CRP) were performed initially. Voiding cystourethrography(VCUG) was performed 1 to 3 weeks after treatment with UTI. $^{99m}Tc$-dimercaptosuccinic acid(DMSA) scan was performed 4 to 6 months after treatment. Results : Scintigraphic renal damage was present in 29 percent of the refluxing and in 3 percent of the nonrefluxing kidneys(P<0.05). The severity of VUR was significantly correlated with renal scar formation(P<0.05). The duration of fever before treatmen($5.0{\pm}1.3$ vs $2.6{\pm}1.3$) and prolonged fever of over 5 days were significantly different between renal scar group and non-renal scar group(P<0.05). ESR($56.3{\pm}23.8$ vs $27.9{\pm}18.1mm/hr$, P<0.05) and CRP($12.8{\pm}7.3$ vs $3.9{\pm}3.8mg/dL$, P<0.05) at the diagnosis of UTI in the renal scar group were higher, compared to those of the non-renal scar group. There were no significant differences in age and sex between the two groups. Conclusion : The presence and grade of VUR, the duration of fever before treatment, prolonged fever over 5 days, ESR, and CRP were risk factors for renal scarring, irrespective of age and sex. Diagnosis and management of VUR, in children with UTI, is important to prevent renal scars.

• Childhood Kidney Diseases
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• v.13 no.2
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• pp.229-234
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• 2009

Purpose : The aim of this study was evaluating the efficacy of endoscopic $Deflux^{(R)}$ submucosal injection in children with primary vesicoureteral reflux (VUR). Methods : Retrospective analysis of medical record was conducted on 38 children (59 ureters) who underwent endoscopic $Deflux^{(R)}$ injection due to primary VUR. Data were collected from March 2000 to February 2006. Mean infused amount of $Deflux^{(R)}$ was 0.77 cc. After $Deflux^{(R)}$ injection, patients were reassessed by voiding cystourethrogram (VCUG) 6 months later. Results : The success rate of endoscopic $Deflux^{(R)}$ submucosal injection 6 months later by VCUG was 100% for grade 1 VUR, 87.5% for grade 2, 60% for grade 3, 26.6% for grade 4, 16.6% for grade 5, respectively and there was negatively significant correlation between success rate and grade of VUR (P<.01). Degree of improvement of VUR by endoscopic $Deflux^{(R)}$ submucosal injection was not related to age at diagnosis, time to operation, existence of voiding dysfunction or constipation and infused amount of $Deflux^{(R)}$. However, group with anticholinergics medication had significantly lower success rate than non-medication group (P<0.047). Conclusion : Endoscopic $Deflux^{(R)}$ submucosal injection is effective therapy in patient with primary VUR, especially low grade VUR. It can be not only a useful substitute for prophylaxis with antibiotics, but also an effective management prior to ureteroneocystostomy in children with primary VUR.

• Childhood Kidney Diseases
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• v.22 no.2
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• pp.71-74
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• 2018

Endoscopic subureteral injection for treatment of vesicoureteral reflux (VUR) is known to be safe and efficient due to its minimal invasive nature. Being non-migratory, non-antigenic, and biocompatible, Macroplastique (Polydimethylsiloxane) is likely to be stable over time. A 5-year-old boy with a past history of subureteral administration of Macroplastique for unilateral Grade V VUR 4 years ago presented with recurrent gross and microscopic hematuria, along with suprapubic pain. On computed tomography (CT) abdomen, calcified material, suspected to be a stone, was visualized in the bladder. On diagnostic cystoscopy, calcification was seen around the orifice site where Macroplastique injection had been performed. We removed the calcific material by Holmium laser. Endoscopic subureteric implantation has several advantages, but nevertheless, vigilance is needed to detect long-term complications, especially in patients with gross or microscopic hematuria.

• Clinical and Experimental Pediatrics
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• v.58 no.9
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• pp.341-346
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• 2015

Purpose: To evaluate the practical applications of the diagnosis algorithms recommended by the American Academy of Pediatrics urinary tract infection (UTI) guideline. Methods: We retrospectively reviewed the medical records of febrile UTI patients aged between 2 and 24 months. The patients were divided into 3 groups: group I (patients with positive urine culture and urinalysis findings), group II (those with positive urine culture but negative urinalysis findings), and group III (those with negative urine culture but positive urinalysis findings). Clinical, laboratory, and imaging results were analyzed and compared between the groups. Results: A total of 300 children were enrolled. The serum C-reactive protein level was lower in children in group II than in those in groups I and III (P<0.05). Children in group I showed a higher frequency of hydronephrosis than those in groups II and III (P<0.05). However, the frequencies of acute pyelonephritis (APN), vesicoureteral reflux (VUR), renal scar, and UTI recurrence were not different between the groups. In group I, recurrence of UTI and presence of APN were associated with the incidence of VUR (recurrence vs. no recurrence: 40% vs.11.4%; APN vs. no APN: 23.3% vs. 9.2%; P<0.05). The incidence of VUR and APN was not related to the presence of hydronephrosis. Conclusion: UTI in febrile children cannot be ruled out solely on the basis of positive urinalysis or urine culture findings. Recurrence of UTI and presence of APN may be reasonable indicators of the presence of VUR.

• Childhood Kidney Diseases
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• v.12 no.2
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• pp.178-185
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• 2008

Purpose : Our aim was to investigate the predictive factors for detecting grade III-V vesicoureteral reflux(VUR) in young infants less than 3 months with urinary tract infections (UTI). Methods : Data of infants who underwent ultrasonography and VCUG between January 2004 and September 2007 were reviewed. Age, gender, incidence of bacteremia, C-reactive protein(CRP) and imaging studies were compared between group I(grade III-V VUR) and group II (normal or grade I and II VUR) retrospectively. Sensitivity, specificity, positive and negative predictive values, odds ratio, and likelihood ratio of ultrasonography for high grade VUR were evaluated. Results : Among 54 enrolled infants(41 males, 13 females), 14 infants were group I and 40 infants were group II. In the group I, CRP level was significantly higher(6.11$\pm$5.18 vs. 3.27$\pm$3.45, P=0.025), and there were more ultrasonographic abnormal findings(71.4%, vs. 22.5%, P=0.002) compared with group II. However, ultrasonography was the only significant factor after adjusting with logistic regression(P=0.002). Incidence of bacteremia and abnormal DMSA findings were not significantly different in two groups. Sensitivity, specificity, and odds ratio of ultrasonography was 71.4%, 77.5%, 6.9 respectively. Negative predictive value was 88.6% and negative likelihood ratio was 0.37. Ultrasonography had significant negative likelihood ratio for grade III-V VUR, but missed 4 infants with grade III VUR. Conclusion : We could not find any alternative predictive factors to reduce VCUG in detecting high grade VUR. Therefore, VCUG must be considered in young infants less than 3 months with UTI.

• Childhood Kidney Diseases
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• v.9 no.1
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• pp.46-55
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• 2005

Purpose : Recurrent urinary tract Infection(UTI) in primary vesicoureteral reflux(VUR) may lead to serious renal scarring, a major cause of childhood hypertension and end-stage renal disease. To prevent recurrent UTI, low-dose long--term antibiotic prophylaxis has been recommended. However, recurrent UTI still develops during antibiotic prophylaxis, the efficacy of which is now being disputed. The emergence of resistant bacteria has also raised concerns. To evaluate the effect of antibiotic prophylaxis, we investigated recurrent UTI during prophylactic antibiotic use in children with primary VUR Materials : The incidence and risk factors of recurrent UTI were retrospectively evaluated in ninety-one children with primary VUR on trimethoprim- sulfamethoxazole(TMP/SMX) prophylafis during the year following their index febri]e UTI. Results : Recurrent UTI occurred in 31.9%(29/91) children and comprised 0.32 episodes/patient year. Febrile UTI was 0.26 episode/patient year and afebrile UTI was 0.07 episodes/patient year. The recurrent rate of UTI in male patients with phimosis was 37.2%(19/51), which was significantly higher than in males without phimosis 0%(0/5)(P=0.025). In the logistic regression analysis for recurrent UTI, renal scar was the significant risk factor for recurrent UTI [RR 3.8(95% CI 1.0-14.1) P=0.04]. For other well-known risk factors such as sex, age, degree of VUR, APN, and voiding dysfunction, the differences were not significant. Conclusion : TMP/SMX prophylaxis did not prevent recurrent UTI in children with primary VUR. Phimosis and renal scars were the risk factors for recurrent UTI but the grade of primary VUR was not. In VUR without phlmosis and renal scar, a randomized controlled study without antibiotic prophylaxis is required. (J Korean Soc Pediatr Nephrol 2005;9:46-55)

• Investigative Magnetic Resonance Imaging
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• v.4 no.2
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• pp.85-93
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• 2000

Purpose: To evaluate the availability of magnetic resonance (MRI voiding cystography for the diagnosis of vesicoureteral reflux (VUR) and to compare the sensitivity of MR voiding cystography (MRVC) with that of radiographic voiding cystourethrography (VCUG) in the detection of VUR. Material and Methods : MRVC was performed upon 20 children referred for investigation of VUR. Either coronal T1-weighted spin-echo or spoiled gradient-echo images were obtained before and after transurethral administration of a mixture of normal saline and gadopentetate dimeglumine, and immediately after voiding. The findings of MRVC were compared with those of VCUG performed within 6 months of MRVC. Results 1 VUR was detected in 23 ureterorenal units f16 VUR's by both methods, five VUR's by VCUG, and two VUR's by MRVC). The sensitivity of VCUG and MRVC in detecting VUR was 91.3% (21/23) and 78.3% (18/23), respectively. MRVC detected renal scarring in 15 out of 17 kidneys with scintigraphically detected renal scarring. Conclusion : Although MRVC is slightly less sensitive than VCUG in the detection of VUR, it can be used for the diagnosis of VUR and renal scarring simultaneouslyl and thus will reduce the radiation hazard.

• Childhood Kidney Diseases
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• v.11 no.2
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• pp.220-228
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• 2007

Purpose : We studied the value of clinical signs, laboratory findings and $^{99m}technetium$ dime-rcaptosuccinic acid(DMSA) scan in predicting the presence of vesicoureteral reflux(VUR) in children with first febrile urinary tract infection(UTI). Methods : A retrospective analysis of 84 hospitalized children with first febrile UTI was performed. They underwent DMSA scan and voiding cystourethrography(VCUG) during the acute phase, and were divided into three groups according to the results of the VCUG: absence of VUR, mild(grade I-II) and severe VUR(grade III-V). We studied the relation of VUR to age, gender, fever duration, causative organism, white blood cell count, serum C-reactive protein and result of DMSA scan. Results : Among 84 patients, 6 had mild and 17 had severe VUR. Thirty-eight had abnormal DMSA scan. results Patients with VUR were older than those without VUR(P<0.01). There was a lower probability of infection with Escherichia coli in patients with severe VUR than in those with mild and absent VUR(P<0.01). An abnormal DMSA scan correlated with the presence and severity of VUR(P<0.05). Severe VUR was present in 10.9% of patients with normal DMSA scan. The sensitivity, specificity, positive and negative predictive values of the DMSA scan in predicting the presence of VUR were 69.6%, 63.9%, 42.1%, and 84.8%, respectively. Conclusion : An abnormal DMSA scan correlated to the presence and severity of VUR, but the sensitivity, specificity and positive predictive value of the DMSA scan were low. There-fore, patient with an abnormal DMSA scan requires a VCUG. In order to prevent missing the 10.9% of patients with severe VUR but normal DMSA scans, a VCUG should be performed in patient with normal DMSA scan.

• Clinical and Experimental Pediatrics
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• v.59 no.3
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• pp.139-144
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• 2016

Purpose: Acute pyelonephritis (APN) is a serious bacterial infection that can cause renal scarring in children. Early identification of APN is critical to improve treatment outcomes. The neutrophil-lymphocyte ratio (NLR) is a prognostic marker of many diseases, but it has not yet been established in urinary tract infection (UTI). The aim of this study was to determine whether NLR is a useful marker to predict APN or vesicoureteral reflux (VUR). Methods: We retrospectively evaluated 298 pediatric patients ($age{\leq}36months$) with febrile UTI from January 2010 to December 2014. Conventional infection markers (white blood cell [WBC] count, erythrocyte sedimentation rate [ESR], C-reactive protein [CRP]), and NLR were measured. Results: WBC, CRP, ESR, and NLR were higher in APN than in lower UTI (P<0.001). Multiple logistic regression analyses showed that NLR was a predictive factor for positive dimercaptosuccinic acid (DMSA) defects (P<0.001). The area under the receiver operating characteristic (ROC) curve was high for NLR (P<0.001) as well as CRP (P<0.001) for prediction of DMSA defects. NLR showed the highest area under the ROC curve for diagnosis of VUR (P<0.001). Conclusion: NLR can be used as a diagnostic marker of APN with DMSA defect, showing better results than those of conventional markers for VUR prediction.