• Clinical and Experimental Pediatrics
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• v.51 no.1
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• pp.54-61
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• 2008

Purpose : This study was designed to clarify the mechanism of proteinuria in nephrotic syndrome patients by using puromycin aminonucleoside (PAN) nephrosis model. Methods : Following administration of various concentrations of PAN and antioxidants we observed the changes of podocyte cytoskeletons in cultured rat glomerular epithelial cells (GEpC) by method of scanning electron microscope, reactive oxyten species (ROS) analysis, permeability assay, confocal microscope, and Western blot assay. Results : PAN not only induced the ultrastructural changes of GEpC, such as shortening and fusion of microvilli, but also separated the intercellular gaps and linear ZO-1. PAN induced oxidative stresses in time and dose dependent manners and increases of intercellular permeability in anti-oxidants inhibitable manners. High concentration of PAN induced not only actin polymerization and disorganization, but also the conglomerulation and internal dislocation of ${\alpha}-actinin$ protein. The intensities of fluorescences of ZO-1 protein were diminished and internalized by PAN in a dose-dependent manner, which were inhibited by anti anti-oxidants. Conclusion : PAN induced the changes of podocytes cytoskeleton and junctional barriers by way of increasing ROS in GEpC that resulted in increasing their permeability in a antioxidatn-inhibitable manner. Glomerular hyperpermeability induced by PAN mediateing through oxidative stresses is thought to take part in the mechanism of proteinuria in nephrotic syndrome.

• Childhood Kidney Diseases
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• v.13 no.2
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• pp.222-228
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• 2009

Purpose : We checked voiding cystourethrography (VCUG) in patients with congenital hydronephrosis (CHN) and followed up the occurrence of urinary tract infection(UTI) in these patients. And we tried to figure out the relationship between CHN and VUR and UTI. Methods : We performed a retrospective study in 122 CHN patients who received VCUG from 2002 to 2008 at Ajou University Hospital. We executed logistic regression, chi-square test and T-test using version 16.0 SPSS package for the statistical analysis. P<0.05 was regarded as significant. Results : Most patients with CHN were male (73%) and there was a tendency of preferences for unilateral (77%) and left (84%) occurrence of hydronephrosis. The incidence of VUR was 18.9% among 122 CHN patients and no laterality difference was found to the severity of VUR or hydronephrosis. The incidences of VUR and UTI was higher in group of higher grade (III-IV) CHN patients, when compared to the lower group, respectively. When VUR was present in CHN patients, the incidence of UTI during infancy was also higher. Conclusion : The incidence of VUR was higher in patients with higher grades of CHN. The incidence of UTI during infancy was higher when VUR was present in the CHN patients.

• Childhood Kidney Diseases
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• v.7 no.1
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• pp.9-15
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• 2003

Purpose : Several studies have suggested that hyperlipidemia might be a causative factor contributing to the progression of initial glomerular injury through the development of glomerulosclerosis. We examined the potential beneficial effect of atorvastatin - which blocks the rate limiting step of cholesterol synthesis by inhibiting HMG-CoA reductase - in PAN-induced nephrosis. Materials and Methods : Glomerulosclerosis was induced in Sprague-Dawley male rats by repeated administration of PAN. Sprague-Dawley male rats were divided into 3 groups : group I(control), group II(PAN 20 mg/kg, subcutaneous injection), group III(PAN 20 mg/kg subcutaneous injection and atorvastatin 50 mg/kg/day per oral). On the 11th week, upon sacrifice of the experimental animals, blood sampling, 24-hr urine collection and nephrectomy were performed. Results : Group III had significantly lower BUN and higher serum albumin($30.9{\pm}17.2\;vs.\;17.3{\pm}2.5\;mg/dL;\;2.3{\pm}0.1\;vs.\;2.5{\pm}0.2\;g/dL$, P<0.05) compared with group II. In the lipid profiles, group III was associated with a reduction in total cholesterol and LDL($291{\pm}173\;vs.\;167{\pm}72\;mg/dL:\;57{\pm}53\;vs.\;27{\pm}12\;mg/dL$, P>0.05) compared with group II. Atorvastatin administration lowered the glomerular sclerosing index significantly(26.2% vs. 13.3%, P<0.05). Conclusion : Puromycin-induced glomerulosclerosis could be ameliorated by the reduction of hyperlipidemia with atorvastatin. This suggests that hyperlipidemia contributes to the pathogenesis of glomerulosclerosis.

• Childhood Kidney Diseases
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• v.5 no.2
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• pp.78-86
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• 2001

Purpose: Rapidly progressive glomerulonephritis (RPGN) is characterized by the rapid increase in serum creatitnin and crescents formation involving more than $50\%$ of glomeruli. 10 patients who had been treated for RPGN were studied retrospectively for thier underlying diseases and clinical features Method: Cilinical review was performed on 10 children who were diagnosed with RPGN by clinical features and renal biopsy and followed up at department of pediatrics during tile last 10 years, from May 1990 to May 2000. Result: There were 6 males and 4 females between the ages of 2.1 and 14.3 years (mean $10.9{\pm}3.8$). 3 had Henoch-$Sch{\ddot{o}}nlein$ purpura nephritis; 2, idiopathic rapidly progressive glomerulonephritis; 2, lupus nephritis; 1, hemolytic uremic syndrome; 1, membranous glomerulonephritis and 1, microscopic polyangiitis. The most common chief complaints were gross hematuria and oliguria. Initial clinical features included proteinuria, edema, hypertension, nausea and arthralgia. Mean serum BUN was $74.2{\pm}39.1\;mg/dL$ mean serum creatinin, $3.2{\pm}1.8\;mg/dL$ and mean creatinin clearance, $26.5{\pm}13.2\;mL/min/1.73m^2$. Antineutrophil cytoplasmic antibody was positive only in microscopic polyangiitis. ANA and Anti-DNA antibody were positive in two lupus nephritis patients. Serum complements were decreased in 4 patients. All patients except Hemolytic uremic syndrome received steroid pulse therapy and immunosupressive agents. 3 patients were performed acute peritoneal dialysis and 2 patients were given plasmapheresis. At the last follow up, 1 patient was dead, 4 patients had elevated serum creatinin, 2 of these 4 patients were on chronic ambulatory peritoneal dialysis and 6 patients had normal renal function. Conclusion: Rapidly progressive glomerulonephritis is a medical emergency that requires very rapid diagnosis, classification, and therapy. Appropriate therapy selected on the basis of underlying disease mechanism can substantially improve renal survival. (J. Korean Soc Pediatr Nephrol 2001 ; 5 : 78-86)

• Clinical and Experimental Pediatrics
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• v.52 no.4
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• pp.464-470
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• 2009

Purpose : This study assessed the incidence and outcome of congenital anomalies of the kidney and urinary tract (CAKUT) detected by prenatal ultrasonography Methods : There were 906 cases of CAKUT detected by prenatal ultrasonography and postnatally confirmed at the Asan Medical Center from October 1989 to October 2007. We investigated the incidence and outcome of these cases by reviewing medical records retrospectively. Results : The order of incidence was hydronephrosis, multicystic dysplastic kidney (MCDK), duplex kidney, vesico-ureteral reflux (VUR), single kidney, hydroureteronephrosis, ectopic kidney, polycystic kidney, ureterocele, and posterior urethral valve (PUV). There were 520 cases (57.4%) of hydronephrosis, and 20% of these needed an operation due to significant obstruction. MCDK was associated with other CAKUT in 25.4% of all cases. Approximately 57.9% of duplex kidney cases needed surgical treatment due to ureterocele and VUR. VUR had a male: female ratio of 10:1. Two out of seven cases of autosomal recessive polycystic kidney had progressed to chronic renal failure. Patients with PUV were relatively uncommon, and one out of nine cases progressed to end-stage renal disease. Conclusion : CAKUTs detected by prenatal ultrasonography were composed of various anomalies, and almost all of them had a good outcome without any intervention. However, in some cases, recurrent urinary tract infection or renal failure occurred, especially in bilateral cases. For further management, a long-term multicenter study is needed to investigate the precise incidence and outcome of each anomaly in the general population.

• Clinical and Experimental Pediatrics
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• v.50 no.1
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• pp.28-32
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• 2007

Purpose : Human angiotensin converting enzyme (ACE) gene shows an insertion/deletion polymorphism in 16 intron, and three genotypes are determined by whether a 287 bp fragment of the DNA is present or not; II, ID and DD genotype. DD genotype has been suggested as a risk factor of chronic nephrotic disease such as IgA nephropathy and diabetic nephropathy, various cardiovascular diseases and several other diseases. ACE activity increases in acute hepatitis, chronic persistent hepatitis, chronic active hepatitis and cirrhosis. On the other hand, patients with fatty livers have normal ACE activity. This study was designed to find out the relation between polymorphsims of the ACE genes and neonatal hyperbilirubinemia in Koreans. Methods : The genomic DNA was isolated from 110 full-term Korean neonates who had hyperbilirubinemia with no obvious causes (serum bilirubin$${\geq_-}12mg/dL$$) and 164 neonates of a control population (serum bilirubin <12 mg/dL). We performed polymerase chain reaction (PCR) to see the allele of the ACE gene. Electrophoresis was done in the PCR products in 1.5 percent agarose gel, and then DNA patterns were directly visualized under ethidium bromide staining. Results : ACE genotypes in the hyperbilirubinemia group are as follows; 26.36 percent for II, 53.64 percent for ID, 20.00 percent for DD, 0.532 for I allele and 0.468 for D allele. These distributions were not significantly different from those in the control group; 24.39 percent for II, 51.83 percent for DI, 23.78 percent for DD, 0.503 for I allele and 0.497 for D allele. Conclusion : In this study, ACE gene polymorphism was detected in the neonatal hyperbilirubinemia and control group. The most frequent genotype was ID. Our results indicate that the ACE gene polymorphism is not associated with the prevalence of neonatal hyperbilirubinemia in Koreans.

• Childhood Kidney Diseases
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• v.10 no.1
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• pp.8-17
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• 2006

Purpose : We describe the changes of rat glomerular epithelial cells when exposed to high levels of glucose and advanced glycosylation endproducts(AGE) in the in vitro diabetic condition. We expect morphological alteration of glomerular epithelial cells and permeability changes experimentally and we may correlate the results with a mechanism of proteinuria in DM. Methods : We made 0.2 M glucose-6-phsphate solution mixed with PBS(pH 7.4) containing 50 mg/mL BSA and pretense inhibitor for preparation of AGE. As control, we used BSA. We manufactured and symbolized five culture dishes as follows; B5 - normal glucose(5 mM) + BSA, B30 - high glucose(30 mM) + BSA, A5 - normal glucose(5 mM) + AGE, A30 - high glucose(30 mM) + AGE, A/B 25 - normal glucose(5 mM) + 25 mM of mannitol(osmotic control). After the incubation period of both two days and seven days, we measured the amount of heparan sulfate proteoglycan(HSPG) in each dish by ELISA and compared them with the B5 dish at 2nd and 7th incubation days. We observed the morphological changes of epithelial cells in each culture dish using scanning electron microscopy(SEM). We tried the permeability assay of glomerular epithelial cells using cellulose semi-permeable membrane measuring the amount of filtered BSA through the apical chamber for 2 hours by sandwich ELISA. Results : On the 2nd incubation day, there was no significant difference in the amount of HSPG between the 5 culture dishes. But on the 7th incubation day, the amount of HSPG increased by 10% compared with the B5 dish on the 2nd day except the A30 dish(P<0.05). Compared with the B5 dish on the 7th day the amount of HSPG in A30 and B30 dish decreased to 77.8% and 95.3% of baseline, respectively(P>0.05). In the osmotic control group (A/B 25) no significant correlation was observed. On the SEM, we could see the separated intercellular junction and fused microvilli of glomerular epithelial cells in the culture dishes where AGE was added. The permeability of BSA increased by 19% only in the A30 dish on the 7th day compared with B5 dish on the 7th day in the permeability assay(P<0.05). Conclusion: We observed not only the role of a high level of glucose and AGE in decreasing the production of HSPG of glomerular epithelial cells in vitro, but also their additive effect. However, the role of AGE is greater than that of glucose. These results seems to correlate with the defects in charge selective barrier. Morphological changes of the disruption of intercellular junction and fused microvilli of glomerular epithelial cells seem to correlate with the defects in size-selective barrier. Therefore, we can explain the increased permeability of glomerular epithelial units in the in vitro diabetic condition.