• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.39 no.12
• /
• pp.921-925
• /
• 2015

The number of people suffering from renal disease increases every year. One of the most common treatments (clinical care options) for renal diseases is hemodialysis. However it takes a long time and has a high cost. Therefore, the importance of artificial kidney research has risen. Filtering creatinine from blood is one of the prime renal functions. Thus, we designed a novel two channel microfluidic chip focused on that function. In order to bond the individual polydimethylsiloxane layers, we have developed a housing system using acrylic plastic frame. This method has significant advantages in changing filter membranes. We use anodic aluminum oxide for the filter membrane. We analyzed the difference in the absorbance values for various creatinine concentrations using the Jaffe reaction. For the purpose of acquiring a standard equation to quantify the creatinine concentration, we interpolated the measured data and confirmed the concentration of the filtered solution. Through this experiment, we determined how the filtration efficiency depended on the flow rate and creatinine concentration.

• Childhood Kidney Diseases
• /
• v.9 no.2
• /
• pp.231-236
• /
• 2005

Juvenile rheumatoid arthritis(JRA) is the most common major connective tissue disease in children. Renal involvement in JRA is rare. Among the renal lesions that have been reported in JRA, amyloidosis and drug-induced nephropathy are the most common. Crescentic glomerulonephritis in JRA has rarely been reported. We report a case of ANCA-associated pauci-immune crescentic glomerulonephritis in JRA. The patient was a 15-year old boy with a 3-year history of JRA. He presented with gross hematuria, proteinuria, positive p-ANCA and elevation of BUN and creatinine. Pathologic findings revealed focal necrotizing and crescentic glomerulonephritis. There were no significant immunoglobulin or complement deposits. His renal function recovered after intravenous methylprednisolone pulse therapy and oral steroid use. In Korea, this is the first reported case of pauci-immune crescentic glomerulonephritis in JRA. (J Korean Soc Pediatr Nephrol 2005;9:231-236)

• Childhood Kidney Diseases
• /
• v.10 no.2
• /
• pp.119-124
• /
• 2006

Purpose : The prognosis of acute poststreptococcal glomerulonephritis(APSGN) has been reported to be favorable. However, several studies have reported that patients with nephrotic range proteinuria in the acute phase or persistent proteinuria may progress to chronic renal failure. To elucidate this further, we analyzed the features of proteinuria and its prognosis in pediatric patients with APSGN. Methods : A total of 48 children with APSGN admitted to our hospital between Jan. 2000 and Dec. 2004 were included. After discharge from the hospital, patients were regularly followed up every month by clinical evaluations and laboratory tests including routine urinalysis and quantification of proteinuria. Results : Age of the patients ranged from 3 to 15 years(median 5.8 years) at the time of disease onset. Proteinuria was present in 34(70.8%) patients and 5 of them showed heavy proteinuria. Proteinuria normalized within one month in most patients(82.3%) and there was no one with proteinuria after 6 months. Cyclosporine A(5 mg/kg/day in two divided doses) was given to 3 patients with massive proteinuria that lasted longer than 2 months and the result was complete remission within 4 months. Conclusions : Our data indicated that the prognosis of APSGN during childhood is excellent. Children with severe proteinuria or subnormal renal function in poststreptococcal glomerulonephritis had favorable prognosis without chronic renal failure, and children with crescentic formation also had favorable prognosis. Three patients who continued to have heavy proteinuria for more than 2 months received cyclosporine A and remission of proteinuria was achieved within a couple of months.

• Childhood Kidney Diseases
• /
• v.10 no.2
• /
• pp.213-218
• /
• 2006

Purpose : Nutcracker syndrome refers to compression of the left renal vein(LRV) between the aorta and superior mesenteric artery(SMA) that results in elevation of pressure in the LRV and development of collateral veins. It must be considered as a possible factor when hematuria or proteinuria occurs in a healthy child. The purpose of this study is to determine the time to spontaneous resolution in childhood nutcracker syndrome, and to observe whether this is affected by sex, age, proteinuria or initial ratio of peak velocity of LRV. Methods : We investigated 26 patients who were found to have spontaneous resolution by follow-up Doppler ultrasonography among 117 patients diagnosed with nutcracker syndrome by renal Doppler ultrasonography from May 2001 to December 2005. We determined the time to spontaneous resolution in childhood nutcracker syndrome, and observed whether the duration was affected by sex, age, proteinuria or initial ratio of peak velocity. Results : 26 patients(59%) achieved spontaneous resolution by 1.2 years(mean). The time to spontaneous resolution of childhood nutcracker syndrome in 26 patients was $16.71{\pm}9.99$ months(range 6.0-49.2). The time to spontaneous resolution was not affected by sex, age, proteinuria nor initial ratio of peak velocity of LRV. Conclusion : More than half of the patients who were diagnosed by renal Doppler ultrasonography achieved spontaneous resolution. The time to spontaneous resolution was not affected by sex, age, proteinuria nor initial ratio of peak velocity of LRV.

• Childhood Kidney Diseases
• /
• v.10 no.2
• /
• pp.162-173
• /
• 2006

Purpose : To report the decreasing indicence of HBV(Hepatitis B virus)-associated membranous nephropathy in children after HBV vaccination and to elucidate the clinical course and treatment strategies of IMN(Idiopathic membranous nephropathy). Methods : We retrospectively reviewed the clinico-pathological findings of HBV-MN and IMN patients who underwent a renal biopsy from 1986 to 2005. We compared the HBV-MN and the IMN groups and the remission and the non-remission groups of patients with IMN. Results : Among 24 cases of MN patients, HBV-MN comprised 6 cases(25%) and IMN 18 cases(75%). Clinical masnifestations were nephrotic syndrome(3 cases, 50%), nephritic syndrome(1 case, 16.7%), asymptomatic(2 cases, 33.4%) in the HBV-MN group, asymptomatic(10 cases, 55.5%), nephrotic syndrome(5 cases, 27.8%), and gross hematuria(3 cases, 16.7%) in the IMN groups. From 1996 to 2000, there were 2 cases(28%) of HBV-MN and 5 cases(72%) of IMN. After 2001 all 10 cases were IMN. In the HBV-MN group, 4 cases(66.7%) received interferon and 1 cases received methylprednisolone pulse therapy. In the IMN group, 16 cases(88.9%) received methylprednisolone, 8 cases(44.4%) were in complete remission, 2 cases(11.1%) were in partial remission, 2 cases(11.1%) were in chronic renal failure, and 5 cases(27.8%) were lost to follow-up with sustained proteinuria, 1 case(5.6%) continued to have frequent relapse of nephrotic syndrome without renal insufficiency. In the comparison between remission and non-remission groups, nephrotic range proteinuria and hypertension were more significantly common in the non-remission group(P<0.05). Conclusion : With HBV vaccination, HBV-MN has decreased markedly. IMN is a rare glomerular disease in children. Because the prognosis for patients with nephrotic range proteinuria is poor this group needs more aggressive treatment.

• Childhood Kidney Diseases
• /
• v.20 no.2
• /
• pp.63-68
• /
• 2016

Purpose: Disruption of normal renal development can lead to congenital anomalies of the kidney and urinary tract, including renal hypodysplasia. We aimed to clarify whether small kidney size affects clinical manifestations in children with urinary tract infection (UTI). Methods: One hundred fifty-four patients who had their first symptomatic UTI between January 2014 and June 2015 were enrolled in this study. Differences in kidney size were estimated based on percent uptake of $^{99m}Tc-$ dimercaptosuccinic acid (DMSA) in scintigraphy. The patients who showed more than 10% difference in kidney size on DMSA scintigraphy with none or minimal cortical defects were included in group A. (group A, n=17). Laboratory, clinical, and imaging results were compared with those of the other patients (group B, n=137). Results: Group A had a relatively higher incidence of vesicoureteral reflux than group B (44% vs 20%, P<0.05). The levels of plasma neutrophil gelatinase-associated lipocalin (NGAL) and serum C-reactive protein were significantly higher in group A (193 [64-337] vs 91 [59-211] ng/mL and 4.1 [0.5-11.9] vs 2.1 [0.7-5.3] ng/mL, respectively; all P <0.05). Linear regression analysis revealed that plasma NGAL level strongly correlated with the difference in renal uptake in DMSA scintigraphy in group A ($R^2=0.505$). Conclusion: The difference in kidney size could influence the clinical course and severity of pediatric UTI.

• The Korean Journal of Physiology and Pharmacology
• /
• v.22 no.2
• /
• pp.135-143
• /
• 2018

Tumor necrosis $factor-{\alpha}$ ($TNF{\alpha}$) and the angiotensin system are involved in inflammatory diseases and may contribute to acute kidney injury. We investigated the mechanisms by which $TNF{\alpha}$-converting enzyme (TACE) contributes to lipopolysaccharide (LPS)-induced renal inflammation and the effect of TACE inhibitor treatment on LPS-induced cellular injury in human renal proximal tubule epithelial (HK-2) cells. Mice were treated with LPS (10 mg/kg, i.p.) and HK-2 cells were cultured with or without LPS ($10{\mu}g/ml$) in the presence or absence of a type 1 TACE inhibitor ($1{\mu}M$) or type 2 TACE inhibitor ($10{\mu}M$). LPS treatment induced increased serum creatinine, $TNF{\alpha}$, and urinary neutrophil gelatinase-associated lipocalin. Angiotensin II type 1 receptor, mitogen activated protein kinase (MAPK), and TACE increased, while angiotensin-converting enzyme-2 (ACE2) expression decreased in LPS-induced acute kidney injury and LPS-treated HK-2 cells. LPS induced reactive oxygen species and the down-regulation of ACE2, and these responses were prevented by TACE inhibitors in HK-2 cells. TACE inhibitors increased cell viability in LPS-treated HK-2 cells and attenuated oxidative stress and inflammatory cytokines. Our findings indicate that LPS activates renin angiotensin system components via the activation of TACE. Furthermore, inhibitors of TACE are potential therapeutic agents for kidney injury.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.21
• /
• pp.9065-9070
• /
• 2014

The incidence of renal cell carcinoma (RCC) is high in Western and Northern Europe and North America, and low in Asia. Although the incidence of RCC in Japan is lower than the rates in the other industrialized countries, there is no doubt that it is increasing. In this paper, we would like to introduce the summary of findings of JACC study, which evaluate the risk factors for RCC in a Japanese population. JACC study suggests nine risk factors (i.e., smoking, obesity, low physical activity, hypertension, diabetes mellitus, kidney diseases, beef, fondness for fatty food and black tea) and one preventive factor (i.e., starchy roots such as taro, sweet potato and potato) in a Japanese population. In Japan, however, drinking black tea may be a surrogate for westernized dietary habits while eating starchy roots may be a surrogate for traditional Japanese dietary habits. Further studies may be needed to evaluate risk factors for RCC because the number of cases is small in our studies.

• Childhood Kidney Diseases
• /
• v.11 no.1
• /
• pp.100-105
• /
• 2007

Cockayne syndrome is a rare autosomal recessive disorder characterized by cachectic dwafism, mental retardation, loss of facial subcutaneous adipose tissue, microcephaly and photosensitive dermatitis. It is associated with renal abnormalities characterized by hyalinization of glomeruli, atrophy of tubules and interstitial fibrosis. To our knowledge, this is the first report of a case of Cockayne syndrome with FSGS in Korea. A 7-year old boy was admitted for evaluation of hypertension and proteinuria, which were detected 2 month ago. He was followed for short stature(<3 percentile), mental retardation(IQ 55), strabismus and dental caries since 3 years ago. He also showed microcephaly, a bird-like face and relatively large hands and feet. Laboratory findings showed decreased creatinine clearance($C_{Cr}$ 76.1 mL/min/$1.73m^2$) and proteinuria(1,548 mg/day). Renal biopsy demonstrated focal segmental glomerulosclerosis of the hilar type with large hyaline deposits, moderate tubular atrophy and interstitial fibrosis. His cardinal features, mental retardation, and renal biopsy findings were consistent with Cockayne syndrome. We report here a very rare case of Cockayne syndrome with FSGS presenting with proteinuria and hypertension.

• Childhood Kidney Diseases
• /
• v.22 no.2
• /
• pp.37-41
• /
• 2018

Purpose: Familial renal glucosuria (FRG, OMIM #233100) is a rare but relatively benign genetic condition characterized by persistent isolated glucosuria with a normal blood glucose level. We report three additional SLC5A2 mutations and examine their phenotypic and genetic characteristics in a Korean FRG cohort. We also reviewed the literature and summarized the genotypes of all Korean patients with FRG. Methods: A genetic analysis was conducted by directly sequencing all 14 exons of the SLC5A2 gene and their flanking regions in six unrelated Korean children with FRG and their family members. Novel non-synonymous single-nucleotide polymorphisms were identified and compared with known mutations that are repeatedly detected in the Korean population. Results: We found two novel mutations [c.274G>A (G92S) and c.1168C>T (L390F)] and one known [c.1382G>A (S461N)] mutation in each family and one recurrent mutation [c.1346G>A (G449D) (rs768392222)] in two pedigrees. The recurrent G449D was predicted to be "possibly damaging," with a score of 0.883 in Polyphen-2, while G92S, L390F, and S461N were predicted to be "probably damaging," with scores of 1.000, 0.999, and 0.996, respectively. Conclusions: Two novel, one previously reported, and one recurrent mutation were identified in six Korean FRG pedigrees as causative mutations of renal glucosuria. Sequence variations in the SLC5A2 gene were frequently detected in children with persistent isolated glucosuria. A long-term follow-up of this FRG cohort is needed to understand how these specific SGLT2 mutations impair kidney function and energy homeostasis.