• Childhood Kidney Diseases
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• v.21 no.2
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• pp.114-120
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• 2017

Purpose: The aim of this study was to determine the clinical characteristics, frequency of renal abnormalities and benefits of a top-down approach in children with their first febrile urinary tract infection (UTI). Methods: We reviewed 308 patients retrospectively who were admitted to Yeungnam University Hospital and were treated for their first febrile UTI from February 2006 to December 2013. We performed a comparative analysis of laboratory findings and results of imaging techniques including a Tc-99m dimercaptosuccinic acid (DMSA) renal scan. Results: Among the patients, 69% (213/308) were males, and 90% (277/308) had their first UTI episode during infancy. A DMSA renal scan was performed on all patients, and showed positive findings in 60% (184/308) of cases. Laboratory indices of inflammation were significantly higher in the DMSA-positive group (P< 0.05). There was a statistically significant difference in the age distribution between the two groups. In the DMSA-positive group, 165 patients underwent voiding cystourethrography (VCUG), and 58 (35%) cases demonstrated vesicoureteral reflux. In total, 110 patients in the DMSA-positive group, underwent repeat scanning at 6 months; 33 children (30%) demonstrated static scarring, but 77 (70%) had improved completely. The concordance of the ultrasonography (US) and VCUG was low. Older patients had more renal scarring. Conclusion: DMSA is a sensitive method for assessing the severity of inflammation and kidney injury. However, the ability of US to predict renal parenchymal damage was limited. A top-down approach in children with their first febrile UTI showed significant value.

• Childhood Kidney Diseases
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• v.6 no.1
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• pp.75-84
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• 2002

Purpose Acute pyelonephritis of growing kidneys may result in renal scarring. TGF-${\beta}1$, inflammatory cytokine, has been suggested to play an important role in promoting renal scarring through apoptosis, suppression of cellular proliferation and fibrosis. We observed the effects of a potent anti-inflammatory agent, methylprednisolone on apoptosis and renal scarring in experimentally induced acute pyelonephritic weaning rats. Materials and Methods: To induce ascending pyelonephritis a saline solution containing Escherichia coli type ATCC No. 25922, pili- form (107 bacteria/mL) was infused into the bladder through the 16-guage silicone cannula for 48 hours to 102 three-week-old Sprague-Dawley rats (50-60g). Experimental groups were divided into three groups according to the treatment protocols, group I (ceftriaxone only, n=3l), group II (methylprednisolone+ceftriaxone n=28), control group (n=43) was not treated. Histopathologic scores of inflammatory changes, fibrosis and tubular atrophy, the apoptosis index and TGF-${\beta}1$ expression score were observed at post-infection 1 and 3 week. Datas were analysed using ANOVA test and P value below 0.05 was interpreted as significant. Results: The mortality rate ($21.4\%$) of group II was not different to the control group ($41.9\%$) and group I ($32.3\%$). The inflammatory score of group II ($0.8{\pm}0.87$) at week 1 was significantly lower than those of the control group ($2.3{\pm}0.87$) and Group I ($1.7{\pm}0.79$) (P<0.05). Apoptosis index of group II ($2.9{\pm}2.15$) at week 1 was significantly lower than those of the control group ($10.0{\pm}1.95$) and group 1 ($8.3{\pm}2.53$) (P<0.05). TCF-${\beta}1$ expression score of group II ($0.8{\pm}0.72$) at week 1 was significantly lower than those of the control group ($1.9{\pm}0.68$) and group I ($1.8{\pm}0.60$) (P<0.05). The fibrosis score of group II ($1.1{\pm}1.10$) at week 3 was significantly lower than that of the group I ($1.8{\pm}0.83$) (P<0.05) Conclusion: Conclusion Combined treatment with methylprednisolone and ceftriaxone reduced inflammation, fibrosis, apoptosis and TGF-${\beta}1$ expression in acute pyelonephritic weaning rats, compared to ceftriaxone alone. Anti-inflammatory agent supplemented to antibiotics could prevent renal scarring more effectively. (J Korean Soc Pediatr Nephrol 2002 ; 6 : 75-84)

• 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.7 no.1
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• pp.44-51
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• 2003

Purpose : Acute pyelonephritis in children may result in permanant renal damage which later in life may lead to hypertension and renal failure. The purpose of this study was to evaluate the factors that might be useful for predicting the development of renal scar in children with urinary tract infection(UTI). Methods : We retrospectively reviewed 442 patients with UTI who were admitted to the Department of Pediatrics of Chonbuk National University Hospital, during the period from April 1992 to March 2002. The patients were divided into two groups according to the presence of renal scar on the follow-up DMSA renal scan, and we compared the factors associated with renal scarring between the two groups. Results : There were no significant differences in sex, causative organism and acute phase reactants between the groups with and without renal scar. The age at diagnosis was significantly higher in the renal scar group compared to that without scar. Of the 60 patients with renal scar, 78% had vesicoureteral reflux(VUR), but 13% of patients without scar had VUR. Furthermore, the severity of VUR was significantly correlated with renal scar formation. 53% showed multiple cortical defects on the initial DMSA renal scan, compared to 32% in the non-scar group. In addition, 76% of patients showing multiple cortical defects on the initial DMSA renal scan with VUR had renal scar. Conclusion : The presence and grade of VUR, and findings on the initial DMSA renal scan would contribute to predict risk of renal scar formation in children with UTI.

• Childhood Kidney Diseases
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• v.20 no.2
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• pp.37-44
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• 2016

Although asymptomatic bacteriuria, cystitis, and acute pyelonephritis (APN) have been categorized as urinary tract infections (UTIs), the immunopathogenesis of each disease is different. APN shows an age predilection; the majority of children (over 70-80%) with APN are under 1-2 years of age, with a male predominance. After 1-2 years of age, female predominance has been reported. This finding suggests that the immature immune state of infancy may be associated with the pathogenesis of APN. Escherichia coli is the most common etiologic agent; other uropathogens associated with UTIs originate from the host and comprise normal flora that are continuously altered by environmental factors. Therefore, uropathogens may have characteristics different from those of extraneous bacterial pathogens. Although antibiotic-resistant uropathogens, including extended-spectrum beta-lactamase-producing strains, are increasing in Korea and worldwide, treatment failure is rare in immune-competent children. The immunopathogenesis of APN remains unknown. Intact bacteria may not be the causative substances in renal cell injury; rather, smaller substances produced during bacterial replication may be responsible for renal cell injury and scarring. Moreover, substances from host cells such as proinflammatory cytokines may be involved in renal cell injury. A dimercaptosuccinic acid scan is used to detect the site of bacterial replication in the renal parenchyma, and may be influenced by the size of the focus and the stage of APN. Traditional aggressive studies used to identify vesicoureteral reflux after the first episode of APN have been modified because of rare cases of chronic kidney disease in patients with recurrent UTI.

• Clinical and Experimental Pediatrics
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• v.46 no.10
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• pp.977-982
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• 2003

Purpose : This study aimed to examine the excretion of various urinary proteins in children with a history of urinary tract infection(UTI), with or without vesicoureteral reflux(VUR) or reflux nephropathy, and to identify means of predicting the severity of VUR or the presence of reflux nephropathy as indicated by these markers, and to know how these markers are changed after resolution of VUR. Methods : We studied 30 children with previous UTI, without VUR and renal scarring(group I), 12 children with VUR, without evidence of renal scarring(group II), and 34 children with VUR and renal scarring(group III). 24-hour or 12-hour urine ${\beta}_2$ microglobulin(${\beta}_2$ MG), microalbumin and N-acetyl-${\beta}$-D-glucosaminidase(NAG) were measured in each child. Urinary protein excretions were analyzed according to the degree of VUR(mild VUR : a grade reflux I-III, severe VUR : a grade reflux IV-V). Cases of bilateral VUR were graded by the higher grade of reflux detected. A total of 46 children with primary VUR were followed. Among these patients, VUR was completely resolved in 16 children. Voiding cystourethrography(VCUG) and DMSA scan were performed every year. Values for urinary markers were estimated every year. Results : 24 or 12 hour urine microalbumin and NAG excretions were significantly increased in group III compared to group I(microalbumin : $27.7{\pm}26.0mg/gCr$ vs $15.0{\pm}10.7mg/gCr$, P<0.05, NAG : $15.2{\pm}18.7U/gCr$ vs $3.4{\pm}2.2U/gCr$, P<0.05). Urinary ${\beta}_2$ MG excretions were not significantly different between groups. Urinary NAG excretions were elevated in the group of children with severe VUR compared to mild VUR($26.8{\pm}27.1U/gCr$ vs $7.6{\pm}3.8U/gCr$, P<0.05). After resolution of VUR, urinary microalbumin and NAG excretions were decreased(P<0.05). Conclusion : Urinary microalbumin and NAG may be useful clinical indicators to predict the presence of reflux nephropathy and the resolution of VUR. Especially, urinary NAG excretions may be used as a possible method to predict the severity of VUR.

• Childhood Kidney Diseases
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• v.7 no.1
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• pp.38-43
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• 2003

Purpose : Accurate diagnosis of acute pyelonephritis(APN) using clinical and laboratory parameters is often difficult in children. Clinical and experimental studies have demonstrated that renal scarring can be prevented or diminished by early diagnosis and aggressive treatment of acute pyelonephritis. dimercaptosuccinic acid(DMSA) renal scan has been reported to be useful in children for confirmation of the diagnosis of acute pyelonephritis. An analysis was undertaken to correlate the clinical and laboratory manifestations of APN With the results of the DMSA renal scan in different age groups. Methods : We determined the sensitivity of DMSA renal scan in febrile urinary tract infections(UTI) in two groups according to age : group I in less than 2 years; group II in older than 2 years. During the period March 2001 through September 2002, 67 children presented with febrile UTIs. All patients had DMSA renal scan done in the acute period, 55 had voiding cystourethrography(VCUG) and 66 had renal ultrasonogram(RUS) done. Results : There were no significant difference between the two groups in DMSA renal scan (P>0.05). But, in group I sensitivity of DMSA renal scan was 47%; in group II sensitivity of DMSA renal scan was 70%. The grade of reflux correlated with a positive DMSA renal scan. Vesicoureteral reflux did not correlate with age. RUS did not correlate with a positive DMSA renal scan in any age group. Abnormality of RUS did not correlate with age. Conclusion : At present, we believe that DMSA renal scan is the prevailing method in differention of the APN. In addition, it is not invasive and less costly. Even though there is no statistical difference in the sensitivity of DMSA renal scan between young and older children, we can observe that in the younger group, the sensitivity of DMSA renal scan seemed to be lower(47%).

• 대한핵의학회:학술대회논문집
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• 2001.11a
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• pp.38.1-38.1
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• 2001

• Journal of Medicine and Life Science
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• v.19 no.2
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• pp.66-69
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• 2022

Patients with vesicoureteral reflux (VUR), the retrograde flow of urine from the bladder to the kidney, are known to experience renal scarring; this results in the worsening of renal function. Reflux nephropathy is a cause of chronic kidney disease, and VUR has also been observed in dialysis patients. VUR is a major underlying precursor condition of urinary tract infection (UTI) and is sometimes accompanied by hydronephrosis. However, there are no guidelines for the management of UTI due to VUR-associated hydronephrosis in patients with end-stage kidney disease. Herein, we report a case of UTI caused by VUR-associated hydronephrosis in a dialysis patient treated with percutaneous nephrostomy.

• The Korean Journal of Nuclear Medicine
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• v.37 no.4
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• pp.245-253
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• 2003

Puorpose: The purpose of this study was to evaluate the usefulness of $^{99m}Tc$ DMSA scintigraphy on the dignosis of a renal scar in children with urinary tract infections. Materials and Methods: Eighty three patients were included in this study, who were diagnosed as the urinary tract infection on the basis of symptom, urinalysis and urine culture. $^{99m}Tc$ DMSA scintigraphy and voiding cystoureterography were peformed within 7days before the treatment in all patients. We classified the scintigraphic findings as follow s : 1 ; a large hypoactive upper or lower pole. 2 ; a small hypoactive area. 3 ; single defect resulting in localized deformity of the outlines. 4 ; deformed outlines in a small or normal sized kidney. 5 ; multiple defects. 6 ; diffuse hypoactive kidney without regional impairment. Follow-up scintigraphy was done at least 6 months after the initial study. When the abnormality on the initial scintigraphy was not completely resolved on the follow-up scan, the lesion was defined as containing a scar. Results: One hundred and fifteen renal units of 166 units(69.3%) showed abnormal findings on the DMSA scintigraphy. 65 units(56.5%) was diagnosed as containing renal scars on follow-up scintigraphies. Incidences of renal scar among renal units showing pattern 3, 4 and 5 on the initial scan was 75%, 78% and 78%, respectively. Whereas many of renal units showing 1, 2 and 6 pattern were recovered(65%, 76%, 50%). Sensitivity, specificity and accuracy of pattern-based DMSA scintigraphic findings on the diagnosis of renal scar was 76.9%, 85.1% and 81.9%, respectively. VUR was significantly associated with the renal scar when the initial DMSA shows unrecoverable findings(pattern 3, 4, 5). Odds ratio of the renal scar in a kidney showing unrecoverable initial scintigraphic findings was 19.1. Odds ratio in a kidney with mild or moderate-to-severe VUR was 3.5 and 14.4 respectively. Conclusion: In the urinary tract infection, renal scar was significantly developed in a kidney showing unrecoverable findings on the initial DMSA scan and VUR on voiding cystoureterography.