• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.1
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• pp.98-103
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• 2009

Purpose: Correct estimation of Glomerular filtration rate (GFR) is very important for an accurate clinical assessment of the kidney function. This study compares four GFR markers, a serum creatinine-based estimation using MDRD formula, Cystatin-C, Cr-51 EDTA 2 samples and 6 samples. Materials and Methods: Serum creatinine concentrations, Cystatin-C serum concentrations and Cr-51 EDTA clearance are measured in 43 patients who received or donated kidney. Results: The correlation coefficient between serum based estimated GFR (MDRD) and Cr-51 EDTA 6 samples was 0.817 (p<0.01). The correlation coefficient between Cystatin-C based GFR and EDTA 6 samples was 0.7322 (p<0.01). Regression analysis showed a statistically significant correlation between Cr-51 EDTA 2 samples and 6 samples (r=0.971, p<0.01). Mean value and ${\pm}2SD$ for the difference between Cr-51 EDTA 2 samples and 6 samples were 4.7 mL/min and ${\pm}9.3$ respectively. Conclusions: The estimation of two samples Cr-51 EDTA showed that the method can be simplified by reducing blood samples without losing its high accuracy.

• Korean Journal of Exercise Nutrition
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• v.16 no.1
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• pp.27-33
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• 2012

This study was conducted to investigate the effect of a 24-week combined exercise training program in older women with hypertension. Women with hypertension who were 70 years and older were randomized into two groups: combined exercise group (CE; n = 15) and a control group (n = 15). The CE group performed a combined exercise training program four times per week for 24 weeks and the control group did not. Five factors, including body composition (percent body fat and skeletal muscle mass), health-related physical fitness, adipocytokines (interleukin-6 [IL-6] and tumor necrosis factor-alpha [TNF-α]), kidney risk factors (glomerular filtration rate [GFR] and cystatin C), and systolic and diastolic blood pressure were measured before and after the program. The findings showed that total muscle mass, health-related physical fitness factors, and GFR increased significantly in the CE group compared to those in the control. Additionally, systolic and diastolic blood pressure and IL-6, TNF-α, and cystatin C levels in the CE group decreased significantly after the intervention. In contrast, total muscle mass decreased significantly and blood pressure remained unchanged in the control group. These results suggest that CE training may positively impact circulating levels of adipocytokines and cystatin C and improve physical fitness levels in elderly women with hypertension. Therefore, CE training helps to prevent renal disease and improve health-related physical fitness, eventually leading to a better quality of life.

• Toxicological Research
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• v.28 no.3
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• pp.179-185
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• 2012

Paecilomyces sinclairiis (PS) is known as a functional food or human health supplement. However concerns have been raised about its kidney toxicity. This study was performed to investigate the kidney toxicity of PS by 13 week-oral administration to rats. Blood urea nitrogen (BUN), serum creatinine, and kidney damage biomarkers including beta-2-microglobulin (${\beta}2m$), glutathione S-transferase alpha (GST-${\alpha}$), kidney injury molecule 1 (KIM-1), tissue inhibitor of matrix metalloproteinase 1 (TIMP-1), vascular endothelial growth factor (VEGF), calbindin, clusterin, cystatin C, neutrophil gelatinase-associated lipocalin (NGAL) and osteopontin were measured during or after the treatment of PS. BUN, creatinine and kidney damage biomarkers in serum were not changed by PS. However, kidney cell karyomegaly and tubular hypertrophy were observed dose-dependently with higher severity in males. KIM-1, TIMP-1 and osteopontin in kidney and urine were increased dose dependently in male or at the highest dose in female rats. Increased urinary osteopontin by PS was not recovered at 2 weeks of post-exposure in both genders. Cystatin C in kidney was decreased at all treatment groups but inversely increased in urine. The changes in kidney damage biomarkers were more remarkable in male than female rats. These data indicate that the PS may provoke renal cell damage and glomerular filtration dysfunction in rats with histopathological lesions and change of kidney damage biomarkers in kidney or urine. Kidney and urinary KIM-1 and cystatin C were the most marked indicators, while kidney weight, BUN and creatinine and kidney damage biomarkers in serum were not influenced.

• Childhood Kidney Diseases
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• v.28 no.1
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• pp.16-26
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• 2024

Patients with kidney disease require frequent blood tests to monitor their kidney function, which is particularly difficult for young children and the elderly. For these people, the standard method is to evaluate serum creatinine or cystatin C or drug levels through venous sampling, but more recently, evaluation using dried blood spots has been used. This narrative review reports information from the literature on the use of dried blood spots to quantify the main markers used to detect kidney diseases. The ScienceDirect and PubMed databases were searched using the keywords: "dried blood on filter paper," "markers of renal function," "renal function," "creatinine," "cystatin C," "urea," "iohexol," and "iotalamate." Studies using animal samples were excluded, and only relevant articles in English or Spanish were considered. Creatinine was the most assessed biomarker in studies using dried blood spots to monitor kidney function, showing good performance in samples whose hematocrit levels were within normal reference values. According to the included studies, dried blood spots are a practical monitoring alternative for kidney disease. Validation parameters, such as sample and card type, volume, storage, internal patterns, and the effects of hematocrit are crucial to improving the reliability of these results.

• Kidney Research and Clinical Practice
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• v.37 no.4
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• pp.338-346
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• 2018

Background: The most common cause of acute kidney injury (AKI) in pregnancy is preeclampsia. Serum cystatin C (CysC) is a potential biomarker of early kidney damage as its levels are not disturbed by volume status changes in pregnancy, and serum CysC levels could serve as a replacement for conventionally used creatinine. In this study, we investigated the serum levels of CysC in severe preeclampsia cases and the associations between CysC levels and poor obstetric outcomes. Methods: Our cohort included severe preeclampsia patients with a normal serum creatinine level. Creatinine was measured to calculate estimated glomerular filtration rate (eGFR) based on the Cockcroft and Gault, Modification of Diet in Renal Disease Study (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations, while CysC was measured to calculated eGFR based on a CysC-based equation. We then evaluated the correlations between serum CysC level, eGFR, and obstetric outcomes. Results: Twenty-six patients were evaluated of which 38.5% delivered preterm and 30.8% had low-birth weight babies. Unlike creatinine-based eGFR and CysC-based eGFR, serum CysC demonstrate significant negative correlation with gestational age. Receiver operating characteristic curve analysis indicated that serum CysC is a potential biomarker of preterm delivery with a cut-off serum level of 1.48 mg/L with 80% sensitivity and 75% specificity. Conclusion: GFR estimation using CysC is likely to be inaccurate in pregnancy. However, we found a significant correlation between preterm delivery and serum CysC level. Our results suggest that serum CysC level has the potential to predict preterm delivery in severe preeclampsia patients.

• Kidney Research and Clinical Practice
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• v.37 no.4
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• pp.313-314
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• 2018

• Clinical and Experimental Pediatrics
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• v.48 no.11
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• pp.1219-1224
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• 2005

Purpose : The prevalence of obesity in children and adolescents has been rising rapidly in Korea because of changes of diet and lifestyle. As with adults, obesity in children and adolescents can cause diabetes mellitus, hyperlipidemia, cardiovascular diseases and renal diseases. The aim of the present study is to examine the relation of obesity, glomerular filtration rate(GFR) and serum cystatin C concentration in children and adolescents. Methods : Data of 115 children and adolescents aged between 6 years and 20 years without clinical evidence of renal diseases were included in the study. From May 2004 to December 2004, blood samples were collected from children and adolescents who were seen at the Department of Pediatrics at Chungang University Yongsan Hospital. Obesity degrees and body mass indices(BMI) were measured, and GFRs were estimated from Schwartz's formula. Serum cystatin C was measured by particle enhanced nephelometric immunoassay using Behring Nephelometer II. Results : GFRs were significantly different between the obese group(BMI >95 percentile, $145.79{\pm}23.10mL/min$) and the non-obese group(BMI <95 percentile, $134.61{\pm}26.19mL/min$) divided by BMI (P=0.031). GFRs were not significantly different between the obese group(obesity degree >120 percent, $144.29{\pm}23.08mL/min$) and the non-obese group(obesity degree <120 percent, $134.54{\pm}26.57mL/min$) divided by obesity degree(P=0.051), but were significantly different between severe obese group (obesity degree >150 percent, $155.55{\pm}20.40mL/min$) and the non-obese group(P=0.004). GFRs were correlated positively with BMI($r^2=0.037$, P=0.039), but were not correlated significantly with obesity degree($r^2=0.030$, P=0.066). Serum cystatin C concentrations were not significantly different between the obese group and the non-obese group, divided by BMI as well as by obesity degree(P>0.05). Conclusion : Obesity may lead to an alteration of renal hemodynamics such as hyperfiltration, appropriate control and management for obesity is necessary.

• Clinical and Experimental Pediatrics
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• v.58 no.11
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• pp.421-426
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• 2015

Purpose: The vancomycin dosage regimen is regularly modified according to the patient's glomerular filtration rate (GFR). In the present study, we aimed to assess the usefulness of serum cystatin C (Cys-C) concentration, compared with serum creatinine (SCr) concentration, for predicting vancomycin clearance (CLvcm) in neonates. Methods: We retrospectively analyzed the laboratory data of 50 term neonates who were admitted to the neonatal intensive care unit and received intravenous vancomycin, and assessed the pharmacokinetic profiles. Creatinine clearance (CLcr) and GFR based on Cys-C (GFRcys-c) were estimated using the Schwartz and Larsson formulas, respectively. Results: The mean CLvcm (${\pm}$standard deviation) was $74.52{\pm}31.17L/hr$, the volume of distribution of vancomycin was $0.67{\pm}0.14L$, and vancomycin half-life was $9.16{\pm}17.42hours$. The SCr was $0.46{\pm}0.25mg/dL$ and serum Cys-C was $1.43{\pm}0.34mg/L$. The peak and trough concentrations of vancomycin were $24.65{\pm}14.84$ and $8.10{\pm}5.35mcg/mL$, respectively. The calculated GFR based on serum creatinine concentration (GFR-Cr) and GFRcys-c were $70.2{\pm}9.45$ and $63.6{\pm}30.18mL/min$, respectively. The correlation constant for CLvcm and the reciprocal of Cys-C (0.479, P=0.001) was significantly higher than that for CLvcm and the reciprocal of SCr (0.286, P=0.044). GFRcys-c was strongly correlated with CLvcm (P=0.001), and the correlation constant was significantly higher than that for CLvcm and CLcr (0.496, P=0.001). Linear regression analysis showed that only GFRcys-c was independently and positively correlated with CLvcm (F=41.9, P<0.001). Conclusion: The use of serum Cys-C as a marker of CLvcm could be beneficial for more reliable predictions of serum vancomycin concentrations, particularly in neonates.

• Diabetes and Metabolism Journal
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• v.42 no.6
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• pp.513-518
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• 2018

Background: Recent studies have correlated serum cystatin C (CysC) with vascular complications, but few studies have investigated this correlation in diabetes patients without nephropathy. This study aimed to evaluate if higher serum CysC levels increase the risk for vascular complications in type 2 diabetes mellitus patients with normal renal function or mild renal impairment. Methods: A total of 806 consecutive patients with type 2 diabetes mellitus who were admitted to the diabetes center of Soonchunhyang University Hospital for blood glucose control were retrospectively reviewed. Patients with nephropathy were excluded. Subjects were categorized into quartiles of serum CysC levels (Q1, ${\leq}0.65mg/L$; Q2, 0.66 to 0.79 mg/L; Q3, 0.80 to 0.94 mg/L; and Q4, ${\geq}0.95mg/L$). Results: The proportion of patients with diabetic retinopathy (DR) (P for trend <0.001), coronary heart disease (CHD) (P for trend <0.001), and stroke (P for trend <0.001) increased across the serum CysC quartiles. After adjustment for confounding factors, the highest serum CysC level remained a significant risk factor for DR (odds ratio [OR], 1.929; 95% confidence interval [CI], 1.007 to 4.144; P=0.040). Compared with Q1, a significant positive association was observed between serum CysC and CHD in Q2 (OR, 7.321; 95% CI, 1.114 to 48.114; P=0.012), Q3 (OR, 6.027; 95% CI, 0.952 to 38.161; P=0.020), and Q4 (OR, 8.122; 95% CI, 1.258 to 52.453; P=0.007). No associations were observed between CysC and stroke after additional adjustment for confounding variables. Conclusion: Serum CysC levels are independently associated with DR and CHD, suggesting that CysC may be useful for identifying type 2 diabetes mellitus patients without nephropathy who are at high risk for vascular complications.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.331-338
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• 2014

Cystatins (CSTs) are reversible and competitive inhibitors of C1A cysteine proteases, corresponding to papain-like cathepsins in plants and animals. A viral CST (CpBV-CST1) was identified from a polydnavirus, Cotesia plutellae bracovirus (CpBV). Our previous study indicated that a transient expression of CpBV-CST1 interfered with immune response and development of Plutella xylostella larvae. To directly demonstrate the protein function, this study produced a recombinant CpBV-CST1 protein (rCpBV-CST1) using bacterial expression system to determine its inhibitory activity against cysteine protease and to assess its physiological alteration in insect immune and development. The open reading frame of CpBV-CST1 encodes a polypeptide of 138 amino acids (${\approx}15kDa$). rCpBV-cystatin protein in BL21 STAR (DE3) competent cells containing a recombinant pGEX4T-3:CpBV-CST1 was over-expressed by 0.5 mM IPTG for 4 h. In biological activity assay, the purified rCpBV-CST1 showed a significant inhibition against papain activity. It inhibited a cellular immune response of hemocyte nodule formation in the beet armyworm, Spodoptera exigua. Moreover, its oral administration retarded larval development of the diamondback moth, Plutella xylostella in a dose-dependent manner. These results suggest that CpBV-CST1 may be applied to control insect pest populations.