Correlation between markers of early renal injury in urine and serum homocysteine elevation / 中华健康管理学杂志

Objective:To investigate the correlation between early renal impairment markers in urine and elevated serum homocysteine.Methods:Clinical data of serum homocysteine (Hcy) and early renal injury markers in urine of the health examination population from the Physical Examination Center of Peking University Third Hospital from January 2019 to May 2020 were retrospectively analyzed (1133 cases). The previous medical history, age, sex, blood pressure, body mass index (BMI) of the subjects were collected. Early urine kidney injury markers, including urine microalbumin (U-mALB), urinary N-acetyl-β-D-glucosaminidase (NAG), urinary albumin to creatinine ratio (UACR), and serum renal function, liver function, blood lipid, myocardial enzyme and glycosylated hemoglobin (HbA 1C), etc. were also collected. Those with incomplete previous history, general information, biochemical indexes and decreased estimated glomerular filtration rate (eGFR) were excluded, and 969 cases were included. The included subjects were divided into the normal group (?15 μmol/L) and the elevated group (≥15 μmol/L) according to Hcy levels, the indexes with significant difference between the two groups were included as independent variables, and the multivariate logistic regression was used to explore the influence factors of Hcy elevation. Results:The male ratio, the incidence of increased U-mALB, NAG and UACR were significantly higher in the elevated group than those in the normal Hcy group (93.4% vs 50.6%, 16.4% vs 8.0%, 23.0% vs 14.0%, 13.9% vs 7.9%) (all P<0.05). Systolic blood pressure, diastolic blood pressure, serum uric acid, calcium, alanine aminotransferase (ALT) and lactate dehydrogenase in the elevated group were higher than those in the normal group [(127.5±15.4) vs (121.9±16.2) mmHg (1 mmHg=0.133 kPa), (78.6±9.3) vs (76.0±11.0) mmHg, (385.9±86.0) vs (335.7±88.2) μmol/L, (2.392±0.086) vs (2.366±0.092) mmol/L, (27.8±21.0) vs (23.8±20.2) U/L, (198.3±28.4) vs (192.2±31.2) U/L] (all P<0.05), while high density lipoprotein cholesterol (HDL-C), serum phosphorus were lower than those in the normal group [(1.21±0.25) vs (1.31±0.30) mmol/L, (1.107±0.154) vs (1.158±0.159) mmol/L] (all P<0.05). The increased systolic blood pressure, male, uric acid, U-mALB, NAG were independent correlative factors of Hcy elevation. Conclusion:The increase of Hcy is independently correlated with urine U-mALB and NAG, which suggests that the level of Hcy should be detected as soon as possible in patients with elevated early renal injury markers.

Study on Combined Determination Plasma NGAL,Cys C and Urinary NAG/Crea for the Diagnosis of Early Diabetic Nephropathy / 现代检验医学杂志

Objective To investigate the value of plasma neutrophil gelatinase-associated lipocalin (NGAL),cystatin C (Cys C) and the ratio of urinary N-acetyl-beta-D-glucosaminidase to creatinine (NAG/Crea) combined determination in the diagnosis of early diabetic nephropathy.Methods Collected 67 cases of patients with type 2 diabetes hospitalized in the First Affiliated Hospital of Kunming Medical University from December 2016 to February 2017.According to the value of UALB/Crea was divided into two groups:Diabetic urinary microalbumin normal group (UALB/Crea＜30 mg/gCrea) had 35 patients and early diabetic nephropathy group (namely the trace albuminuria group,UALB/Crea 30 ～ 300 mg/gCrea) had 32 patients.Other selected 20 normal volunteers as control group,compared with a medical group to gather all the staff of the clinical data,using automatic biochemical analyzer detected the plasma NGAL,Cys C and urine NAG/Crea,and adopted the receiver-operating characteristic (ROC) curve of the detection index was analyzed.Results ①Plasma NGAL,Cys C and urinary NAG/Crea of diabetic nephropathy patients was significantly higher than those of healthy control group (Z=-5.740 ～-5.386,P＜0.05).②The areaunder receiver operating characteristic (ROC) curve of plasma NGAL,Cys C and urine NAG/Crea were 0.858,0.911 and 0.714.Conclusion Plasma NGAL,Cys C and urinary NAG/Crea combined determination have a higher value for early diagnosis of diabetic nephropathy.

Evaluation of urinary N-acetyl-beta-D-glucosaminidase as a marker of early renal damage in patients with type 2 diabetes mellitus / Avaliação da N-acetil-beta-D-glucosaminidase urinária como marcador de dano renal precoce em pacientes com diabetes melito tipo 2

Objective To evaluate the clinical usefulness of urinary N-acetyl-beta-D-glucosaminidase (NAG) excretion for the detection of early tubular damage in type 2 diabetes mellitus (T2DM). Subjects and methods Thirty six patients with T2DM were divided into two groups based on urinary albumin to creatinine ratio (ACR): normoalbuminuria (ACR <30 mg/g; n=19) and microalbuminuria (ACR =30‐300 mg/g; n=17). The following parameters were determined in both groups: urinary NAG and albumin, serum and urine creatinine, fasting plasma glucose and glycated hemoglobin (HbA1c). Results Urinary NAG levels [Units/g creatinine; median (range)] were significantly increased in microalbuminuria group [17.0 (5.9 - 23.3)] compared to normoalbuminuria group [4.4 (1.5 - 9.2)] (P<0.001). No differences between groups were observed in fasting glucose, HbA1c, serum creatinine levels and estimated glomerular filtration rates (eGFR). Urinary NAG positively correlated with ACR (r=0.628; p<0.0001), while no significant association was observed between NAG and glycemia, HbA1c, serum creatinine and eGFR. Conclusions The increase of urinary NAG at the microalbuminuria stage of diabetic nephropathy (DN) suggests that tubular dysfunction is already present in this period. The significant positive association between urinary NAG excretion and ACR indicates the possible clinical application of urinary NAG as a complementary marker for early detection of DN in T2DM. .

Objetivo Avaliar a utilidade clínica da excreção urinária da N-acetil-beta-D-glucosaminidase (NAG) para a detecção de dano tubular precoce no diabetes melito tipo 2 (DM2). Sujeitos e métodos Foram estudados trinta e seis pacientes com DM2 que se dividiram em dois grupos com base na excreção urinária de albumina (EUA): normoalbuminúrico (EUA <30 mg/g de creatinina; n=19) e microalbuminúrico (EUA =30‐300 mg/g de creatinina; n=17). Em ambos os grupos foram determinados os seguintes parâmetros: NAG e albumina urinária, creatinina sérica e urinária, glicemia de jejum e hemoglobina glicada (HbA1c). Resultados Os níveis de NAG urinária [unidades/g de creatinina; mediana (intervalo interquartílico)] foram significativamente maiores no grupo microalbuminúrico [17,0 (5,9 - 23,3)] em comparação com o grupo normoalbuminúrico [4,4 (1,5 - 9,2)] (p<0,001). Não se observaram diferenças significativas entre os dois grupos nos níveis de glicemia de jejum, HbA1c, creatinina sérica e taxa de filtração glomerular estimada (TFGe). A NAG urinária se correlacionou positivamente com o EUA (r=0,628, p<0,0001), não sendo observada associação significativa da NAG com glicemia, HbA1c, creatinina sérica e TFGe. Conclusões O aumento da NAG urinária na fase de microalbuminúria da nefropatia diabética (ND) sugere que a disfunção tubular já está presente nesse período. A associação positiva significativa entre a excreção urinária da NAG e EUA indica a possível aplicação clínica da NAG urinária como marcador complementar para a detecção precoce da ND no DM2. .

Expression of serum cystatin C(Cys C) and urinary N-acetyl-beta-D-glucosaminidase(NAG) in elderly diabe-tes patients with early renal injury / 中国基层医药

Objective To explore the expression of serum cystatin C ( Cys C ) and urinary N-acetyl-beta-D-glucosaminidase ( NAG) in elderly diabetes patients with early renal injury .Methods 127 cases of diabetes were di-vided into the pure diabetic group ,early diabetic nephropathy group ,diabetic nephropathy ,and the other 38 cases of healthy persons as the control group.The serum Cys C,and serum Creatinine(Scr)concentration by automatic bio-chemical analyzer were detected ,urinary NAG activity was detected by colorimetric determinate ,24 hours albumin ex-cretion rate(UAER/24h)was tested.Results The serum Cys C,urinary NAG,Scr,UAER/24h showed an increasing trend in four groups of patients respectively ,the difference was statistically significant (P<0.05 or P<0.01).The se-rum Cys C and urinary NAG showed a positive correlation with Scr and UAER /24 h respectively .The accuracy ,sensi-tivity,specificity of serum Cys C in diagnosis of early diabetic nephropathy group were 86.8%,76.1%,97.8% re-spectively,The accuracy,sensitivity,specificity of NAG in diagnosis of early diabetic nephropathy group were 83.5%, 71.7%,95.6%.Conclusion The serum Cys C and urinary NAG could sensitively reflect early elderly diabetic renal damage,which were the ideal endogenous indicators of glomerular filtration rate (GFR).

Correlation between glomerular filtration rate and urinary N acetyl-beta-D glucosaminidase in children with persistent proteinuria in chronic glomerular disease / 소아과

PURPOSE: Urinary excretion of N acetyl-beta-D glucosaminidase (NAG) and beta2-microglobulin (beta2-M) was increased in the presence of proximal tubular damage. Based on these urinary materials, we investigated the ability of expecting renal function in chronic glomerular diseases. In this study, we evaluated the relationship between glomerular filtration rate (GFR) urinary NAG, and urinary beta2-M. METHODS: We evaluated 52 children with chronic kidney disease at the Chung-Ang University Hospital between January 2003 and August 2009. We investigated the 24-hour urinalysis and hematologic values in all 52 patients. Serum creatinine, creatinine clearance (Ccr), serum cystatin C, urinary beta2-M and urinary NAG were measured. RESULTS: Out of 52 patients, there were 13 children with minimal change in disease, 3 children with focal segmental glomerulosclerosis, 17 children with immunoglobulin A nephropathy, 15 children with Henoch-Schonlein purpua nephritis, 3 children with poststreptococcal glomerulonephritis, and 1 child with thin glomerular basement membrane disease. In these patients, there were significant correlation between the Ccr and urinary NAG (r=-0.817; P<0.01), and between the GFR (as determined by Schwartz method) and urinary NAG (r=-0.821; P<0.01). In addition, there was a significant correlation between the GFR (as determined by Bokencamp method) and urinary NAG (r=-0.858; P<0.01). CONCLUSION: In our study, there was a significant correlation between the GFR and urinary NAG, but there was no correlation between the GFR and urinary beta2-M, suggesting that the GFR can be predicted by urinary NAG in patients with chronic glomerular disease.

Urinary Protein and Enzyme Excretion of Spot Urine in Children with Vesicoureteral Reflux

PURPOSE: The aim of this study was to evaluate the clinical usefulness of measurement of beta2 microglobulin (beta2 MG), N-acetyl-beta-D-glucosaminidase (NAG) of spot urine samples as indices of renal tubular damage and microalbumin of spot urine samples as a parameter of glomerular damage in children with vesicoureteral reflux (VUR) or renal defects. METHODS: We studied 91 children with previous UTI. The children were classified as 62 children without VUR and renal defects (group I), 10 children with VUR, without renal defects (group II), and 19 children with VUR and renal defects (group III). Patients having VUR were separated according to the degree of VUR (mild VUR: VUR grade I-III, severe VUR: VUR grade IV-V). Urinary excretion of beta2 microglobulin (beta2 MG), microalbumin, N-acetyl-beta-D-glucosaminidase (NAG), creatinine were measured in samples of morning urine specimens. Children with VUR or renal defects detected by voiding cystourethrography (VCUG) and DMSA renal scan were investigated. RESULTS: Microalbumin/Cr ratio of spot urine was significantly increased in group III compared group I (42.3+/-27.2 mg/gCr vs 25.2+/-10.9 mg/gCr, P<0.05). NAG/Cr ratio of spot urine was significantly increased in group II compared group I (3.70+/-23.4 mg/gCr vs 18.7+/-12.7 mg/gCr, P<0.05). There was no statistically significant difference of beta2 MG/Cr ratio among three groups. CONCLUSION: Urinary microalbumin excretion of morning urine sample may be a simple and reliable clinical indicators for early identification of renal damage in children with VUR and renal defects. Urinary microalbumin excretion may be useful marker to predict the the severity of VUR.

Urinary N-Acetyl-beta-D-Glucosaminidase and beta 2-Microglobulin in Children with Various Renal Diseases

PURPOSE: Urinary N-acetyl-beta-D-glucosaminidase(NAG) and beta 2-microglobulin(B2M) is considered to be a marker of tubulointerstitial injury. The aim of this study was to examine the urinary levels of NAG and B2M in children with various renal diseases. METHODS: We studied 21 children(8.9+/-4.5 years, Male:Female=14:7) and they were divided into three groups: group I(steroid-sensitive nephrotic syndrome-4 patients), group II(various kinds of glomerulonephritis-4 patients), and group III(normal urinalysis or non-glomerular renal diseases-13 patients). RESULTS: Urinary NAG levels in groups I and II were significantly higher than those in group III(19.4+/-11.5 and 30.0+/-30.1 vs. 4.7+/-3.9, P=0.01), while urinary B2M levels did not differ among the 3 groups, although urinary NAG levels were positively correlated with urinary B2M levels(r=0.49, P=0.03). Urinary NAG and B2M levels were all correlated with proteinuria(r=0.79, P<0.001 and r=0.68, respectively, P=0.001) serum albumin(r=-0.72, P<0.001 and r=-0.57, respectively, P=0.01) and cholesterol(r=0.58, P=0.006 and r=0.56, respectively, P=0.013) levels. Conclusions: Urinary excretions of NAG and B2M are increased in children with steroid-sensitive nephrotic syndrome and various kinds of glomerulonephritis, suggesting tubular dysfunction might be present in these diseases.

Increased urinary n-acetyl-beta-d-glucosaminidase activity in children with hydronephrosis

OBJECTIVE: Hydronephrosis leads to deterioration of renal function. As urinary N-acetyl-beta-D-glucosaminidase (U-NAG) activity is considered a sensitive marker of renal tubular impairment, our aim was to measure U-NAG in children with hydronephrosis and to look for a relationship among selected clinical parameters. MATERIALS AND METHODS: We studied 31 children (22 boys and 9 girls, mean age 2.3 ± 2.5 years) with hydronephrosis grade 1-4 that had U-NAG/creatinine ratio (U-NAG/Cr) measured. RESULTS: The U-NAG/Cr was significantly higher in patients with hydronephrosis compared to reference data (p = 0.002). There was no difference in U-NAG/Cr between children with unilateral and bilateral hydronephrosis (p = 0.51). There was no significant difference in U-NAG/Cr between children with grades 1-3 (pooled data) and grade 4, respectively (p = 0.89). There was no correlation between U-NAG/Cr and the grade of hydronephrosis (r = 0.01). CONCLUSIONS: U-NAG/Cr is increased in children with hydronephrosis grade 1-4, and there is no relationship with the grade of hydronephrosis. U-NAG is a useful marker of renal tubular dysfunction, however its relationship with the degree of kidney damage in patients with hydronephrosis should be considered as doubtful.

Role of Urinary N-acetyl-beta-D- glucosaminidase Level in Prediction of Pathological Tubular Lesion and Prognosis in Subclinical Asymptomatic IgA Nephropathy / 대한신장학회잡지

PURPOSE: Urinary N-acetyl-beta-D-glucosaminidase (NAG) has been known to reflect the damage of proximal tubular cells in the early stages of renal disease. Recent studies have demonstrated that tubular grade predicted renal outcome better than did other histological parameters in IgA nephropathy. We evaluated the meaning of urinary NAG in relation with initial histological features and renal outcomes in early subclinical IgA nephropathy. METHODS: Among the firstly diagnosed IgA nephropathy patients from Jan 2001 to Dec 2002, 43 subjects were selected with the criteria of normal renal function and 24-h urinary protein excretion <3.5 g/day. The subjects were followed for 2 years. Pathologic lesion was graded according to HASS classification and semiquantitative scorings, from 0 to 3, were carried out for glomerular (GG), interstitial (IG), tubular (TG), and vascular (VG) lesion. RESULTS: The subjects consisted of 20 male and 23 female with mean age of 30+/-13 years, baseline blood pressure 116+/-15/74+/-10 mmHg, Cr 1.03+/-0.24 mg/dL, Ccr 88+/-19 mL/min, 24-h urinary protein excretion (UPER) 1, 790+/-1, 610 mg/24-h, urinary NAG 11.8+/-11.0 U/g cr at the time of biopsy. Hass subclass was correlated significantly with glomerular, tubular, and interstitial grades (all p<0.05). In comparison with clinical parameters, glomerular grade was significantly related with 24-h UPER (p<0.05) and tubular grade was significantly related with systolic blood pressure (p<0.05). Urinary NAG level at the time of biopsy show significant correlation with tubular grade (p<0.05). Progression of renal disease occurred in nine patients (20.9%). The patients with renal disease progression showed significantly low baseline Ccr, high 24-h UPER, and high NAG (all p<0.05). In pathological findings, tubular grade was significantly related with renal prognosis (p<0.05). In regression analysis, tubular grade was a independent predictor of renal prognosis among above four parameters showing significant differences. In survival analysis, tubular grade 0, 1 and grade 2, 3 showed significant difference in renal survival as compared to each other. The patients with baseline NAG urinary NAG above 10 U/g Cr showed significantly worse renal survival as compared with those below 10 U/g Cr (p<0.05). CONCLUSION: Tubular lesion is an independent factor associated with renal progression in these patients. Urinary NAG reflects well the degree of tubular lesion at the time of biopsy. We carefully suggest, therefore, that the measurement of urinary NAG level is helpful to estimate tubular lesion and predict renal prognosis in subclinical asymptomatic IgA nephropathy patients before they undergo renal biopsy.

Urinary Excretion of Various Urinary Proteins in Children with Vesicoureteral Reflux

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 beta2 microglobulin(beta2 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+/-26.0 mg/gCr vs 15.0+/-10.7 mg/gCr, P<0.05, NAG : 15.2+/-18.7 U/gCr vs 3.4+/-2.2 U/gCr, P<0.05). Urinary beta2 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+/-27.1 U/gCr vs 7.6+/-3.8 U/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.

Changes of Superoxide Dismutase Activity in Cadmium-induced Acute Nephrotoxicity of Rats / 대한산업의학회지

OBJECTIVES: To investigate the role of superoxide dismutase(SOD) in the pathogenesis of cadmium-induced acute nephrotoxicity. METHODS: Rats treated with a single intraperitoneal injection of cadmium(as CdCl2, 1 mg/kg) were included in the cadmium-treated group; the control group comprised untreated rats. 24-hour urine samples were obtained prior to sacrifice on days 1, 2, 4, 8 and 16(N = 10 per group), respectively. The activity of SOD and concentration of cadmium were measured in the homogenates of the renal cortex. Nephrotoxicity indices such as N-acetyl-beta-D-glucosaminidase(NAG) activity, total protein, and 24-hour urine volume, and the cadmium concentrations in the urine were measured. RESULTS: The cadmium injection caused a significant increase of cadmium concentration in the renal cortex on days 1 and 2, and in the urine on days 1, 2 and 4. The NAG activities and total protein concentrations in urine were significantly increased on days 1, 2 and 4, and on days 1, 4 and 8, respectively. The peak values of NAG activity and total protein in urine were observed on days 1 and 4, respectively. A significant decrease of 24- hour urinary volume was induced on day 1. Renal SOD activity was significantly inhibited on day 1. Finally, on day 8, SOD activity was significantly increased and all nephrotoxicity indices except urinary total protein returned to the control level. CONCLUSIONS: These results suggest that cadmium induces initial depression of SOD enzyme activities in the renal cortex followed by a later activation, and that the initial depression of this enzyme plays an important role in mediating the proteinuric injury of cadmium-induced acute nephrotoxicity.

A Study on Urinary Cadmium Concentration and Renal Indices of Inhabitant in an Abandoned Mine Area / 예방의학회지

Urinary cadmium is used as a sensitive indicator for internal Cd dose, and increased excretion of N-acetyl-beta-D-glucosaminidase(NAG), beta(2)microglobulin(MG) and total protein are useful indices for renal dysfunction by chronic exposure to Cd. The target group was 184 inhabitant(82 men and 102 women) in an abandoned mine area known as exposure to low level Cd. The control group was took 160 individuals(64 men and 96 women) in Cd not-exposed area. Urinary Cd concentration was significantly higher in the target group than the control. The geometric mean of urinary Cd for male was 2.56ng/l, 2.80ng/g creatinine and 2.50ng/S.G. in the target group and 1.19ng/l, 1.36ng/g creatinine and 1.17ng/S.G. in the control. For female 2.69ng/l, 3.94ng/g creatinine and 2.63ng/S.G. in the target group and 1.27ng/l, 1.97ng/g creatinine and 1.25ng/S.G. in the control, respectively. In addition, urinary Cd of the target group had affected by the period of residence and dietary habit for the rice and the vegetables from the target area. These findings suggest the chronic exposure to Cd of the target population. Mean excretion of urinary NAG, beta(2)MG and total protein were not significant between two groups. In the target group, urinary NAG activity and total protein were significantly correlated with urinary Cd, but beta(2)MG was not related. Urinary excretion of NAG, beta(2)MG and total protein were significantly increased in 10 than in <2 of urinary Cd level. In 2~10 group of urinary Cd level, the excretion of NAG significantly increased while not showed for beta(2)MG. In present study, urinary excretion of NAG was relatively sensitive than beta(2)MG in chronic exposure population to low level Cd.

Some Renal Function Indices in Workers Occupationally Exposed to Lead / 대한산업의학회지

The influence of lead exposure on renal function was studied. Three hundred forty two male lead exposed workers who worked in 3 storage battery factories, 5 secondary smelting factories and 3 litharge making factories, and 60 male control workers who were not exposed to lead occupationally were chosen for this study. Blood lead (PbB), zinc protoporphyrin in whole blood (ZPP) and delta-aminolevulinic acid in urine (DALA) were selected as indicators of lead exposure. As indicators of renal function blood urea nitrogen(BUN) , serum creatinine(S-Cr), serum uric acid (S-UA), N-acetyl-beta-D-glucosaminidase in urine (NAG) and urine protein (U-TP) were selected. While the mean values of lead exposure indicators of lead workers were significantly different from non-exposed ones, the mean values of renal function indicators of exposed except S-UA were significantly different from non-exposed. The frequency of workers whose value of renal function indicators were over the nor mal criteria (BUN>20 mg/dl ; S-Cr>1.2 mg/dl ; S-UA>7.0 mg/dl ; NAG>8.0 U/liter; U-TP>8.0 mg/dl) by the level of lead absorption in terms of PbB, ZPP and DALA were calculated. Age adjusted odds ratio of over the normal value of BUN and NAG were statistically significant by the level of ZPP and that of BUN only showed the dose-dependant relationship. But the frequency of over the normal criteria of renal function indicators were not increased by the level of PbB and DALA. On stepwise multiple regression using renal function indicators as a dependent variable and each lead exposure indicator and age as independent variables, only BUN, NAG and U-TP were contributed by the lead exposure indicators. It was found that only NAG of renal function indices was most reliable indicator who showed dose-response relationship with lead exposure and the measurement of NAG for lead workers whose relatively high exposure is highly recommended.

Usefulness of Urinary n-acetyl-beta-d-Glucosaminidase(nag) for a Predictor of Aminoglycoside Nephrotoxicity / 대한신장학회잡지

Nephrotoxicity is a major factor limiting the clinical utility of aminoglycoside antibiotics(AG). In this study, we have therefore investigated the usefulness of the renal tubular protein for a predictor of the nephrotoxicity of AG. We have also compared the nephrotoxicity among different AG. Among the simple fracture patients visiting orthopedics, for whom an AG seemed warrantable, we have sampled thirty-nine subjects--excluding those suffering from severe bleeding, taking drugs, or having renal disease which can affect the renal function. We have set three different groups by the following criteria; ten subjects in group I were given 250mg of Amikacin sulfate twice a day; fifteen subjects in GroupII were given 60mg of Micronomicin sulfate twice a day; and fourteen subjects in GroupIII were given 200mg of Isepacin sulfate twice a day. Urine from each patient was collected for 24 hours before, one week after, and two weeks after the drugs were given, and then the urinary concentrations of NAG, beta2-Microglobulin(beta2-MG), and electrolyte(Na+, K+, Cl-) were measured. The measurement of 24-hour urinary concentrations of NAG shows that, for all three groups, significant increase of the concentrations(P<0.01) is seen between the different times in the same group. The results of measurements of the 24-hour urinary concentrations of beta2-MG, and electrolyte(Na+, Ke+, Cl-) show their increase for all three groups but whithin the normal range. For the samples collected two weeks after the drugs were given, there is a significant decrease in the twenty-four-hour urinary concentrations of NAG(P<0.05) of Group III compared to Group I and II. The resulta of measurements of 24-urinary concentrations of beta2-MG, and electrolyte(Na+, K+, Cl-) show their increase for all three groups but whithin the normal range. In conclusion, we have seen that the nephrotoxicity of the AG appears for all three groups; but, when we compare the nephrotoxicity between the different antibiotics, the nephrotoxicity of Amikacin sulfate and that of Micronomicin sulfate appear stronger than that of Isepacin sulfate. Our data suggest the usefulness of sequential NAG measurements in monitoring and predicting aminoglycoside nephrotoxicity.

Prediction of Steroid Responsiveness in the Primary Nephrotic Syndrome Using Urinary beta2-Microglobulin Level and N-Acetyl-beta-D-Glucosaminidase Activity

PURPOSE: Considering that renal biopsy is not routinely indicated in nephrotic syndrome in children and the risk of the procedure, we studied that it is possible to predict steroid responsiveness in nephrotic syndrome and the difference in responsivenss is related with the histopathologic type using urinary beta2-microglobulin and N-Acetyl-beta-D-Glucosaminidase activity as a safe and noninvasive method. METHODS: We measured serum creatinine, albumin, cholesterol and urinary creatinine, protein, B2M, NAG at the time of admission and after 2 weeks of treatment in 37 cases of primary nephrotic syndrome in children who were admitted to the Pediatric department of Chung-Ang Medical Center between March 1, 1994 and June 30, 1996. RESULTS: The results were as follows : 1) When urinary B2M value of less than 1000microgram/g creatinine was used as the cut-off value, the test identified steroid responsiveness with a sensitivity of 100%, a specificity of 80%. When urinary NAG activity of less than 100U/hr/mg creatinine was used as the cut-off value, the test identified steroid responsiveness with a sensitivity of 100%, a specificity of 81.8%. 2) Pretreatment urinary B2M levels in Good-response and Poor-response group were 559.8+/-718.5microgram/g creatinine, 3599.1+/-4956.7microgram/g creatinine, respectively. There was statistical significance between the two groups (P<0.05). 3) Pretreatment urinary NAG activity in Good-response and Poor-response group were 42.6+/-23.6U/hr/mg creatinine, 79.6+/-80.1U/hr/mg creatinine, respectively. There was statistical significance between the two groups (P<0.05). CONCLUSIONS: In conclusion, measurement of urinary B2M level and NAG activity for early detection of renal tubular damage is helpful in prediction of steroid responsiveness of primary nephrotic syndrome. If the urinary B2M level and NAG activity are elevated, the patient is suspected to steroid resistance. Therefore, prolonged steroid therapy should be avoided in such patients because of their greater chance of not responding. This approach would reduce the many serious side effects of prolonged treatment in patients who are unlikely to benefit.

Biological Indices for Early Detection of Cadmium Poisoning: Significance of Urinary Metallothionein / 대한산업의학회지

Metallothionein(MT) is a low molecular weight protein that is induced as a defence mechanism for cadmium (Cd) toxicity. In present study, urinary MT was determined using a competitive ELISA in Cd-exposed rats. In addition, measures the urinary, blood and renal Cd concentration and the urinary excretion of total protein, beta 2-microglobulin (MG) and N-acetyl-beta-D-glucosaminidase(NAG) at 1, 3, 7, 14, 28 days after Cd injection in Cd-exposed rats with dosers of 0.8 and 1.6 mg Cd/kg body weight respectively. The urinary, blood and renal Cd were specific for Cd-exposure, that increased in proportional to dose of Cd. The urinary and blood Cd tended to slightly decrease, while renal Cd tended to increase by lapse of time after Cd exposure. this finding indicates that renal Cd is more specific than urinary and blood Cd for Cd exposure. The urinary excretion of MT showed a statistically significant increase in Cd exposed rats(0.8 and 1.6 no Cd/kg body weight). The increase of urinary excretion of MT was more evident at 7, 14, 28 lays after Cd exposure than the changes of urinary excretion of total protein, beta-MG and NAG. The Pearson's correlation coefficients between urinary Cd and urinary MT, beta-MG, NAG and total protein were 0.4344, 0.3727, 0.3307 and 0.2099, respectively. These findings indicate that the urinary MT is more sensitive and specific than total protein, beta-MG and NAG for Cd exposure. The present results suggest that the urinary MT, using a simple and rapid competitive ELISA, is a valuable index as screening test in epidemiologic study for Cd exposed group.

A Study of the Correlation Between the Activity of Erythrocyte Pyrimidine 5'-Nucleotidase and Urinary N-Acetyl-beta-D-Glucosaminidase in Lead Exposed Workers / 대한산업의학회지

In this study, we measured the activity of the erythrocyte pyrimidine 5'-nucleotidase (P5N) and urinary N-acetyl-beta-D-glucosaminidase (NAG) from 154 workers exposed to lead and 43 workers not exposed. We analyzed the correlation of the P5N activity and NAG activity with other biological exposure indices of lead such as blood lead (PbB) and zinc protoporphyrin (ZPP). The measurement was performed by using high performance liquid chromatography (HPLC), spectrophotometer and atomic absorption spectrophotometer. The results are as follows: 1. The mean value of P5N activity for workers exposed to lead was 9.50+/-.13 micromol uridine/hr/g Hb and 11.60+/-.2 micromol uridine/hr/g Hb for workers not exported. The P5N activity showed a normal distribution, but the other indices of lead showed logarithmic normal distributions. 2. The P5N activity and ZPP were decreased as PbB wag increased. But the NAG activity had no correlation with changes of PbB. 3. The correlation coefficients of the P5N activity with other biological exposure indices of lead such as PbB, ZPP, NAG activity were -0.72, -0.55, and 0.05, respectively. We speculated that the P5N activity can be used as a reliable biological exposure index of lead but NAG activity can be used as a biological management index of lead.

Renal Dysfunction Indicators in Lead Exposed Workers / 대한산업의학회지

A range of indicators is available to assess renal dysfunction in lead exposure. This study was undertaken to find out which indicators were most valuable as markers of renal dysfunction. We selected 75 male workers from the secondary lead smelter, plastic stabilizer and radiator manufacturing industries (the "exposed" group) and 64 male office workers (the "control" group). Blood lead; blood zinc protoporphyrin; urine lead; urine coproporphyrin; delta-aminolevulinic acid dehydratase activity; and urine delta-aminolevulinic acid were chosen as indicators of lead exposure. Blood urea nitrogen; serum creatinine; serum uric acid; urine N-acetyl-beta-D-glucosaminidase; urine albumin; urine alpha1-microglobu-lin; and urine beta2-microglobulin were used as indicators of renal dysfunction. Urine alpha1-microglobulin level was significantly associated with, the lead exposure level. Blood urea nitrogen, urine N-acetyl-beta-D-glucosaminidase and urine alpha1-microglobulin levels were highly correlated with indicators of lead exposure. Urine alpha1-microglobulin had the highest correlation with other indicators of renal function. In addition, the proportion of subjects with high urine alpha1-microglobulin levels showed a gradient with lead exposure. Conclusively, Blood urea nitrogen, urine N-acetyl-beta-D-glucosaminidase and urine alpha1-microglobulin are useful indicators, but urine alpha1-microglobulin is ; the early 'and the most valuable indicator of renal dysfunction related to lead exposure.

Renal Dysfunction Indicators in Lead Exposed Workers / 대한산업의학회지

A range of indicators is available to assess renal dysfunction in lead exposure. This study was undertaken to find out which indicators were most valuable as markers of renal dysfunction. We selected 75 male workers from the secondary lead smelter, plastic stabilizer and radiator manufacturing industries (the "exposed" group) and 64 male office workers (the "control" group). Blood lead; blood zinc protoporphyrin; urine lead; urine coproporphyrin; delta-aminolevulinic acid dehydratase activity; and urine delta-aminolevulinic acid were chosen as indicators of lead exposure. Blood urea nitrogen; serum creatinine; serum uric acid; urine N-acetyl-beta-D-glucosaminidase; urine albumin; urine alpha1-microglobu-lin; and urine beta2-microglobulin were used as indicators of renal dysfunction. Urine alpha1-microglobulin level was significantly associated with, the lead exposure level. Blood urea nitrogen, urine N-acetyl-beta-D-glucosaminidase and urine alpha1-microglobulin levels were highly correlated with indicators of lead exposure. Urine alpha1-microglobulin had the highest correlation with other indicators of renal function. In addition, the proportion of subjects with high urine alpha1-microglobulin levels showed a gradient with lead exposure. Conclusively, Blood urea nitrogen, urine N-acetyl-beta-D-glucosaminidase and urine alpha1-microglobulin are useful indicators, but urine alpha1-microglobulin is ; the early 'and the most valuable indicator of renal dysfunction related to lead exposure.

Effect of Intravenous Immunoglobulin(IVIG) on Renal Function in Very Low Birth Weight Infants

PURPOSE: This study was conducted to evaluate the effect of IVIG infusion on renal function in VLBW infants. IVIG has been proved quite safe in neonates given prophylactic and therapeutic doses. But nephrotoxicity is not recognized as adverse in IVIG therapy, only several previous adult cases have been noted. METHODS: For a total of ten VLBW infants who had not been received any medication except parenteral nutrition, vitamin and Fe supplements was assigned for study. To observe changes in renal function after preventive dose of IVIG administration(500mg/kg, 1dose) serum BUN and creatinine, 2-microglobulin( 2-MG) and N-acetyl- -D-glucosaminidase(NAG) were obtained prior to study and 1, 3 and 7 days after infusion. RESULTS: 1) There were no elevation of serum BUN and creatinine after IVIG administration, 2) There was transient increase of urine NAG from 1.1+/-0.7 u/mg creatinine before infusion to 2.7+/-5.3 u/mg creatinine on the first day of infusion, which was not statistically significat, decreasing to pretreatment level on the 3rd and 7th days after infusion. 3) There was transient increase of urine 2-MG from 294.6+/-223.8 microgram/mg creatinine before infusion to 680.0+/-108.9 microgram/mg creatinine on the first day and 416.0+/-246.3 microgram/mg creatinine on 3rd day after infusion, which was not statistically significant. CONCLUSIONS: It was found that prophylactic dose of IVIG in VLBW infants does not cause clinically significant impairment of renal function. but mild increment of urine NAG and 2-MG may suggest the possibility of renal tubular damage. Based on these results, further evaluation of the effect of IVIG on renal function in VLBW infant is recommended.