• Korean Journal of Radiology
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• 제21권5호
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• pp.588-597
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• 2020

Objective: To investigate the value of combined chemical exchange saturation transfer (CEST) and conventional magnetization transfer imaging (MT) in detecting metabolic and structural changes of renal fibrosis in rats with unilateral ureteral obstruction (UUO) at 3T MRI. Materials and Methods: Thirty-five Sprague-Dawley rats underwent UUO surgery (n = 25) or sham surgery (n = 10). The obstructed and contralateral kidneys were evaluated on days 1, 3, 5, and 7 after surgery. After CEST and MT examinations, ¹⁸F-labeled fluoro-2-deoxyglucose positron emission tomography was performed to quantify glucose metabolism. Fibrosis was measured by histology and western blots. Correlations were compared between asymmetrical magnetization transfer ratio at 1.2 ppm (MTR_asym(1.2ppm)) derived from CEST and maximum standard uptake value (SUV_max) and between magnetization transfer ratio (MTR) derived from MT and alpha-smooth muscle actin (α-SMA). Results: On days 3 and 7, MTR_asym(1.2ppm) and MTR of UUO renal cortex and medulla were significantly different from those of contralateral kidneys (p < 0.05). On day 7, MTR_asym(1.2ppm) and MTR of UUO renal cortex and medulla were significantly different from those of sham-operated kidneys (p < 0.05). The MTR_asym(1.2ppm) of UUO renal medulla was fairly negatively correlated with SUV_max (r = -0.350, p = 0.021), whereas MTR of UUO renal medulla was strongly negatively correlated with α-SMA (r = -0.744, p < 0.001). Conclusion: CEST and MT could provide metabolic and structural information for comprehensive assessment of renal fibrosis in UUO rats in 3T MRI and may aid in clinical monitoring of renal fibrosis in patients with chronic kidney disease.

• Childhood Kidney Diseases
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• 제21권2호
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• pp.47-52
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• 2017

Purpose: Renal ultrasonography has been widely used in children with renal disease. However, the relationship of renal echogenicity with renal pathology and function in children is not well known. Method: Ultrasound examination was performed in 75 patients undergoing renal biopsy for suspected renal disease in Konkuk University Medical Center from August 2005 to November 2015. We compared renal echogenicity to pathologic findings and renal function. Renal echogenicity was scored as 0 to 2 by comparing adjacent liver echogenicity. Three histologic characteristics were evaluated: glomerular changes, interstitial infiltration or fibrosis, and tubular atrophy. These were graded as 0 to 3, according to increasing severity. Laboratory results included urine albumin excretion and estimated glomerular filtration rate (eGFR). Results: Among pathologic findings, renal echogenicity revealed a positive correlation with interstitial infiltration or fibrosis (r=0.259, P=0.025), and with tubular atrophy (r=0.268, P=0.02). Renal echogenicity and glomerular changes were not correlated. Renal echogenicity showed a positive correlation with microalbuminuria (r=0.283, P=0.014), but a negative correlation with eGFR (r=-0.352, P=0.002). Conclusion: Increased renal echogenicity suggested severe interstitial infiltration or fibrosis and tubular atrophy among the pathologic findings. Moreover, increased echogenicity is correlated with increased urine albumin excretion and decreased eGFR. Echogenicity on ultrasonography is useful for determining the status of renal pathology and function.

• 한국콘텐츠학회논문지
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• 제12권9호
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• pp.250-256
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• 2012

골밀도 감소에 의해서 발생되는 골감소증, 골다공증 등은 폐경 후 여성에게 유병률이 높은 질환이며, 골다공증 골절에 따른 사회적 의료비 상승으로 의학적 관심이 급증하고 있다. 신부전환자는 체내에 비타민D 합성 능력이 저하되어 칼슘 흡수가 감소하여 뼈의 섬유화가 발생되고, 골밀도가 감소하는 현상이 나타난다. 따라서 신부전환자는 신장 기능 장애로 그치지 않고, 골다공증과 같은 골밀도 감소에 따른 합병증에 노출되어 있다. 본 연구에서는 치료 중에 있는 신부전환자들의 골밀도 변화를 관찰하였고, 신장이식 전후에서 발견되는 골밀도 변화를 분석하였다. 조사대상은 부산 B종합병원 신장내과 내원환자 중 신부전환자 214명을 신장이식의 유무에 따라 골밀도의 변화를 세대별, 성별로 나누어 분석했다. 분석결과 신장이식 환자군에서는 골밀도가 유지되거나 개선되었지만, 비신장이식 환자군에서는 골밀도가 꾸준히 나빠지는 결과를 보였다. 신부전환자는 신장이식을 받는 것이 최선의 치료책으로 사료되며, 신장이식을 통해서 골밀도의 개선이 가능함을 확인하였다. 이는 추가적으로 예상되는 합병증을 예방하기 위한 자료로도 활용할 수 있다.

• 동의생리병리학회지
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• 제17권1호
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• pp.118-122
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• 2003

Oxidative stress and its consequent lipid peroxidation exert harmful effects, which have been currently involved in the generation of carbon tetrachloride (CCl₄)-induced fibrosis(cirrhosis). In this study, it was investigated whether dried extract of 田螺(Concha Cipangopaludinae; CC) has liver functional improvement, antioxidative and antifibrotic effect in rats those were induced liver fibrosis by CCl₄ administration. The female Sprague-Dawley rats were divided into 3 groups(Normal, AC, AC-CC) and were observed in 6 weeks. Except for normal group, liver fibrosis(cirrhosis) in rats were developed by CCl₄ administration(0.8 ㎖/rat/week). And the rats were treated with prepared CC(p. o. 2 ㎖/day/rat). At the time of sacrifice, the liver, kidney and spleen were weighed and the ratio of organ weight/body weight was calculated. The MDA, hyp and biochemical parameters(AST, ALT, ALP, t-bili) were measured in sera and liver tissue of rats. The strong yellow color of urine was observed in all CCl₄-treated group compared with normal group, but jaundice didn't appear in CCl₄-treated group. The mortality of CCl₄-treated group is very low(<13%) during 6 weeks of observation time. The ratio of liver/body as well as the weight of liver in CCl₄-treated rats significantly increased compared with that in normal group(p<0.001). The level of clinical parameters in sera of all liver fibrosis(cirrhosis) developed rats were significantly higher than that of normal group(p<0.001-0.05). Especially the value of BUN, ALP, t-bilirubin in AC-CC group showed 20.9%, 19.6%, 47.9% lower than that in AC group. The content of hyp in CCl₄-treated rats was significantly higher than normal group(p<0.001～<0.05), and showed 12.2% lower value in the AC-CC group than AC group(p<0.05). The production of lipid peroxidation(MDA) in sera and liver tissue significantly increased under the fibrotic(cirrhotic) condition(p<0.001～<0.05). Especially the MDA value of AC-CC group in sera significantly 46.5% decreased compared with that of AC group(p<0.05), and the MDA value of AC-CC in liver tissue showed 21.4% lower than that of AC group. Concha Cipangopaludinae can be improved hepatic function, and maybe have effect of liver protection, antioxidation and antifibrosis.

• Childhood Kidney Diseases
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• 제6권1호
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• pp.85-91
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• 2002

서 론 : Phosphodiesterase (PDE) 억제제는 세포내 cAMP를 증가시키며, cAMP는 TGF-${\beta}1$에 의한 connective tissue growth factor (CTGF)의 발현을 억제하는 것으로 알러져 있다. 그러므로 저자들은 PDE 억제재가 TGF-${\beta}1$의 변화 없이 긴 섬유화를 억제할 수 있는지를 확인해 보고자 본 연구를 시행하였다. 방 법 : 백서에서 일측성 요관 결찰로 신 간질 섬유화를 유발하였다. 실험군에서는 PDE3 억제제인 cilostazol (1 g/L)이나 PDE5, PDE6, PDE8의 hybrid 억제제인 dipyridamole (750 mg/L)이 첨가된 음료수를 공급하였다. 일주일 후 신장을 적출하여 Masson-trichrome score를 평가하고, 신조직 조건배지에서 fibronectin과 TGF-${\beta}1$을 ELISA법으로 정량하였다. 결 과 : 대조군에 비해 cilostazol 군에서 Masson-trichrome score와 신조직 조건배지의 fibronectin 농도가 유의하게 낮았다(P<0.05). Dipyridamole군의 Masson-trichrome score와 조건배지의 fibronectin 농도도 대조군에 비해 낮아 보였으나 통계적 유의성을 보여주지 못했다. 신조직 조건배지의 TGF-${\beta}1$ 농도는 대조군, cilostazol군, dipyridamole군간에 차이가 없었다. 결 론 : 선택적 PDE3 억제제인 cilostazol은 TGF-${\beta}1$의 억제에 의존하지 않고 일측성 요로 폐쇄에 의한 신 섬유화를 억제하였다.

• 생명과학회지
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• 제19권10호
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• pp.1360-1367
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• 2009

간섬유화는 지속적인 간세포 손상에 대한 수복현상으로 일어나며, 급성 염증반응과 같은 손상이 주어진 후에는 간세포의 괴사 및 세포외기질의 축적이 일어나게 된다. 간섬유화에 대한 새로운 치료방법을 모색하기 위하여 본 연구에서는 간섬유화 과정에서 염증 반응과 관련된 NF-$\kappa$B와 세포외기질의 축적과 관련된 Sp1전사인자를 동시에 조절하여 간섬유화 억제효과를 관찰하고자 하였다. 전사인자인 Sp1과 NF-$\kappa$B를 동시에 억제하기 위하여 한 분자 내에 Sp1과 NF-$\kappa$B의 전사인자와 결합하는 부위를 가지는 Chimeric (Chi) decoy oligodeoxynucleotide (ODN)을 제작하였다. Chi decoy ODN은 활성화된 간성상세포에서 간섬유화 와 관련된 유전자 발현을 억제시켰으며, 섬유화 동물모델에서도 간 조직의 염증 반응 및 섬유화 관련 인자의 발현을 현저히 억제시켰다. 따라서 Chi decoy ODN은 간섬유화 및 활성화된 간성상세포의 활성을 억제할 수 있는 유전자 치료제로 고려될 수 있을 것으로 사료된다.

• Childhood Kidney Diseases
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• 제20권2호
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• pp.83-87
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• 2016

Congenital chloride diarrhea (CLD) is a rare autosomal recessive disease that is difficult to diagnose. CLD requires early treatment to correct electrolyte imbalance and alkalosis and to prevent severe dehydration. Renal injury is clearly associated with defective electrolyte balance induced by CLD, particularly during the first months or years of life. A 7-year-old boy was diagnosed with CLD following detection of a homozygous mutation (c.2063-1G>T) in SLC26A3 at 6 months of age. During treatment with electrolyte supplements, mild proteinuria was detected at 8 months of age, and is still present. Renal biopsy showed the presence of focal renal dysplasia, with metaplastic cartilage and mononuclear cell infiltration, calcification, and fibrosis in the interstitium. Up to two-thirds of the glomeruli exhibited global obsolescence, mostly aggregated in the dysplastic area. In nondysplastic areas, the glomeruli were markedly increased in size and severely hypercellular, with increased mesangial matrix, and displayed segmental sclerosis. The marked glomerular hypertrophy with focal segmental glomerulosclerosis suggested a compensatory reaction to the severe nephron loss or glomerular obsolescence associated with renal dysplasia, with superimposed by CLD aggravating the tubulointerstitial damage.

• Biomolecules & Therapeutics
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• 제28권1호
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• pp.25-33
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• 2020

Several recent studies have reported that reactive oxygen species (ROS), superoxide anion and hydrogen peroxide (H₂O₂), play important roles in various cellular signaling networks. NADPH oxidase (Nox) isozymes have been shown to mediate receptor-mediated ROS generation for physiological signaling processes involved in cell growth, differentiation, apoptosis, and fibrosis. Detectable intracellular levels of ROS can be induced by the electron leakage from mitochondrial respiratory chain as well as by activation of cytochrome p450, glucose oxidase and xanthine oxidase, leading to oxidative stress. The up-regulation and the hyper-activation of NADPH oxidases (Nox) also likely contribute to oxidative stress in pathophysiologic stages. Elevation of the renal ROS level through hyperglycemia-mediated Nox activation results in the oxidative stress which induces a damage to kidney tissues, causing to diabetic nephropathy (DN). Nox inhibitors are currently being developed as the therapeutics of DN. In this review, we summarize Nox-mediated ROS generation and development of Nox inhibitors for therapeutics of DN treatment.

• Tuberculosis and Respiratory Diseases
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• 제45권4호
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• pp.823-834
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• 1998

연구배경: 유리규산(silica) 자극에 의해 폐장내 대식세포에서 형성되는 proinflammatory cytokines인 IL-1$\beta$, IL-6, TNF-$\alpha$와 fibrogenic cytokine인 TGF-$\beta$, PDGF는 섬유화 과정에 매우 중요한 역할을 한다. 그러나 이러한 cytokine 의 역할과 상호관련성에 대해서는 아직 확실히 밝혀진 바없다. 본 연구는 Balb/C mouse의 폐장단구세포를 silica로 자극시 형성되는 IL-6, TNF-$\alpha$ 폐섬유화의 발생과 유지에 중요한 역할을 할 것으로 기대되는 TGF-$\beta$ 의 생성을 관찰하고 TGF-$\beta$의 생성에 proinflammatory cytokine이 미치는 영향에 대해서 알아보고자 하였다. 방 법: Balb/C 의 폐장대식세포를 silica로 자극한 후 IL-6, TNF-$\alpha$ TGF-$\beta$의 양을 bioassay로 측정하였고 mRNA의 발현을 in situ hybridization을 통해 관찰하였으며, 대식세포의 TGF-$\beta$ 생성에 대한 IL-1$\beta$, IL-6, TNF-$\alpha$의 영향을 알기 위하여 L-1, IL-6, TNF-$\alpha$에 대한 중화항체를 이용하여 대식세포의 TGF-$\beta$의 생성 억제 유, 무를 관찰하였다. 결 과: Silica로 대식세포자극시 TNF-$\alpha$는 초기 4 시간째 최고의 생성능을 보였으며, IL-6 는 silica 0.2 ${\mu}g/ml$의 농도에서 배양 8 시간째 생성능이 가장 높았고 배양 12 시간째는 다시 감소하였다가 24시간째 증가하는 biphasic한 소견을 보여 주었다. TGF-$\beta$는 silica의 양과 관계없이 배양 24시간째 자연생성능뿐 아니라, silica로 자극시에도 증가되었다. Silica와 TNF-$\alpha$ 50ng/ml을 함께 자극시 TGF-$\beta$의 생성은 현저히 증가되었으며, TNF-$\alpha$ 50 ng/ml과 IL-6 50 ng/ml으로 동시 자극시에는 TNF-$\alpha$에 의한 TGF-$\beta$의 형성이 증가하는 경향을 보였다. TNF-$\alpha$의 중화항체를 전처치 후 silica 자극시 TGF-$\beta$의 생성능을 억제시킴을 관찰할 수 있었다. Anti-IL-$\beta$, anti-IL-6, anti-TNF-$\alpha$ antibody 모두를 통시에 투여하였을 때도 silica에 의한 TGF-$\beta$의 생성능을 억제시킴을 관찰할 수 있었다. Silica 자극 후 대식세포의 in situ hybridization에서 TNF-$\alpha$ mRNA는 2시간째부터 발현되었고 IL-6 mRNA는 4 시간째부터 발현된 후 8 시간째 소실되었고 TGF-mRNA는 12 시간째 가장 강한 발현을 보였다. 결 론: Silica 자극에 의해 폐장대식세포는 자극 초기에는 TNF-$\alpha$가 가장먼저 형성되고 후기에 TGF-$\beta$가 형성되며 TNF-$\alpha$가 TGF-$\beta$ 형성에 중요한 역할을 할 것으로 사료되었다.

• The Korean Journal of Physiology and Pharmacology
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• 제25권2호
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• pp.139-146
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• 2021

Mitochondrial NADP+-dependent isocitrate dehydrogenase 2 (IDH2) produces NADPH, which is known to inhibit mitochondrial oxidative stress. Ureteral obstruction induces kidney inflammation and fibrosis via oxidative stress. Here, we investigated the role and underlying mechanism of IDH2 in unilateral ureteral obstruction (UUO)-induced kidney inflammation using IDH2 gene deleted mice (IDH2-/-). Eight- to 10-week-old female IDH2-/- mice and wild type (IDH2+/+) littermates were subjected to UUO and kidneys were harvested 5 days after UUO. IDH2 was not detected in the kidneys of IDH2-/- mice, while UUO decreased IDH2 in IDH2+/+ mice. UUO increased the expressions of markers of oxidative stress in both IDH2+/+ and IDH2-/- mice, and these changes were greater in IDH2-/- mice compared to IDH2+/+ mice. Bone marrow-derived macrophages of IDH2-/- mice showed a more migrating phenotype with greater ruffle formation and Rac1 distribution than that of IDH2+/+ mice. Correspondently, UUO-induced infiltration of monocytes/macrophages was greater in IDH2-/- mice compared to IDH2+/+ mice. Taken together, these data demonstrate that IDH2 plays a protective role against UUO-induced inflammation through inhibition of oxidative stress and macrophage infiltration.