• Childhood Kidney Diseases
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• v.12 no.2
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• pp.143-149
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• 2008

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$\pm$4.5 years, Male:Female=14:7) and they were divided into three groups: group I(steroid-sensitive nephrotic syndrome-4 patients), group II(various kinds of glomerulonephritis-4 patients), and group III(normal urinalysis or non-glomerular renal diseases-13 patients). Results : Urinary NAG levels in groups I and II were significantly higher than those in group III(19.4$\pm$11.5 and 30.0$\pm$30.1 vs. 4.7$\pm$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 steroidsensitive nephrotic syndrome and various kinds of glomerulonephritis, suggesting tubular dysfunction might be present in these diseases.

• Korean Journal of Veterinary Research
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• v.33 no.3
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• pp.531-537
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• 1993

A study was carried out to define the relationship between the N-acetyl-$\beta$-D-glucosaminidase(NAGase) levels and isolated pathogenic bacteria in 379 quarter fore milk of mastitis suspected samples collected in this clinics. All samples were tested the NAGase, California mastitis test(CMT), Somatic cell count(SCC) and bacterial culture. Except 111 from 379 samples, 268 bacteria-positive quarter fore milk samples were classified into the latent and mastitis infection group by SCC($500,000cells\;per\;m{\ell}$), and the mean NAGase levels($nmol/min/m{\ell}$) of each isolated pathogen in mastitis infection group were Staphylococcus aureus 3.067, Coagulase-negative staphylococci 4.083, Staphylococcus aureus 3.594, Str. uberis 3.513, Str. dysgalactiae 1.640, E coli 4.441 and gram negative rods 4.560, respectively. Most of the relationship between mean SCC and NAGase in each pathogen group were highly significant using a student t test(p<0.05). When the mastitis pathogens were classified into minor(Coagulase-negative staphylococci, Corynebacterium sp.) and major pathogen group(Staphylococcus aureus, Streptococcus agalactiae, Str. uberis, Str. dysgalactiae, gram negative rods), the NAGase levels were higher at major than minor pathogen group. On the other hand, when the mastitis milk samples were classified by SCC($500,000cells\;per\;m{\ell}$) and by the presence of pathogen(IDF scheme), the NAGase levels were also higher at the mastitis than latent infection. The possibility of combining SCC and NAGase data in order to give the more difinitive diagnosis is discussed.

• BMB Reports
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• v.35 no.3
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• pp.313-319
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• 2002

N-Acetyl-$\beta$-D-hexosaminidase ($\beta$-HexNAc'ase) (EC 3.2.1.52) was purified from rice seeds (Oryza sative L. var. Dongjin) using ammonium sulfate (80%) precipitation, Sephadex G-150, CM-Sephadex, and DEAE-Sephadex chromatography, sequentially. The activities were separated into 7 fractions($F_1-F_7$) by CM-Sephadex chromatography. Among them, F6 was further purified to homogeneity with a 13.0% yield and 123.3 purification-fold. The molecular mass was estimated to be about 52 kDa on SDS-PAGE and 37.4 kDa on Sephacryl S-300 gel filtration. The enzyme catalyzed the hydrolysis of both p-nitrophenyl-N-acetyl-$\beta$-D-hexosaminide (pNP-GlcNAc) and p-nitrophenyl-N-acetyl-$\beta$-D-hexosaminide (pNP-GalNAc) as substrates, which are typical properties of $\beta$-HexNAc'ase. The ratio of the pNP-GlcNAc'ase activity to the pNP-GalNAc'ase activity was 4.0. However, it could not hydrolyze chitin, chitosan, pNP-$\beta$-glucopyranoside, or pNP-$\beta$-glucopyranoside. The enzyme showed $K_m$, $V_{max}$ and $K_{cat}$ for pNP-GlcNAc of 1.65 mM, $79.49\;mM\;min^{-1}$, and $4.79{\times}10^6\;min^{-1}$, respectively. The comparison of kinetic values for pNP-GlcNAc and pNP-GalNAc revealed that the two enzyme activities are associated with a single binding site. The purified enzyme exhibited optimum pH and temperature for pNP-GlcNAc of 5.0 and $50^{\circ}C$, respectively. The enzyme activity for pNP-GlcNAc was stable at pH 5.0-5.5 and $20-40^{\circ}C$. The enzyme activity was completely inhibited at a concentration of 0.1 mM $HgCl_$ and $AgNO_3$, suggesting that the intact thiol group is essential for activity. Chloramine T completely inhibited the activity, indicating the possible involvement of methionines in the mechanism of the enzyme.

• Korean Journal of Microbiology
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• v.31 no.1
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• pp.93-98
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• 1993

To investigate the organic matter transformation in aquatic environment, seasonal fluctuations of heterotrophic activity and microbia] extracellular enzyme activity were studied in Paldang Lake, Korea. The turnover time in the water column and the sediment at the station I fluctuated between 3 -I ,300 hrs and 17-170 hrs for glucose, 5 -1.900 hrs and 15-240 hrs for protein hydrolysate and 4-350 hrs and 15-230 hrs for acetic acid, respectively, indicating that the seasonal turnover time of organic substrates fluctuated drastically. The respiration ratios of glucose. protein hydrolysate and acetate were 23-32%, 38-41% and 22-28% in the water column and 34%, 61% and 41% in the sediment. respectively. These results showed that the respiration ratios in the sediment were higher than those in the water column regardless of kinds of organic substrates. The bacterial extracellular enzyme activities of $\alpha$-glucosidase. $\beta$-glucosidase, N-acetyl-$\beta$-D-glucosaminidase and aminopeptidase were 32-44%. 31-32%, 18-34% and 61-67% in the water column, and 34%. 40%, 23% and 65% in the sediment. respectively.

• Toxicological Research
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• v.12 no.1
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• pp.47-52
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• 1996

The renal toxicity of the extract of Polygalae Radix was investigated in rats. Rats were treated with 3.5 mg/Kg of the extract, i.p., for 7 days. Changes in consumatory behavior, 24 hour-urine and the activities of urinary enzymes were determined during the administration of the extract. Significant decrease in body weight and food consumption and increase in 24 hour-urine volume were observed during the administration. However, the quantity of total creatinine in urine was decreased significantly. Those indicate that subacute treatment with the extract might induce diuresis and the ditiresis might be due to the decrease in water reabsorption. In the activities of urinary enzymes, the activities of alanine aminopejotidase (AAP) and gamma-glutamyl transpeptidase (GGT) were increased 4.3 and 3.5 times and then returned to the control. The activity of N-acetyl-${\beta}$-D-glucosaminidase (NAG) was increased 7.2 times and then decreased slowly. But, it was significantly higher than that of the control evea after the last administration. The activity of factate dehydrogenase (LDH) was increased continuozlsly during the treatment. It showed 32 times higher than the control. These results suggested that the extract of Polygalae Radix had toxic effect on kidney. Furthermore, the result suggested that the subacute administration of the extract induced resistance against the toxicity of Polygalae Radix.

• Toxicological Research
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• v.12 no.2
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• pp.277-281
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• 1996

To evaluate the renal toxicity of the antitumor agent, 5-(piperidonomethylphenyl)-2,3-dihydroimidazo[2,1-a]isoquinoline (SDZ-62-434), rats were treated with SDZ-62-434 of 50 mg/Kg, i.p., once and 10 mg/Kg, i.p., daily for 7 days. The kidney weights and urine volume after and during the treatment were observed. The concentrations of urinary creatinine, protein, and the activities of N-acetyl-$\beta $D-glucosaminidase (NAG), alanine aminopeptidase (AAP), $\gamma$-glutamyl transpeptidase (GGT) and lactate dehydrogenase (LDH) in 24 hr urine were also determined. The kidney weights after acute and subacute administration was not affected. The urine excretions were increased 5 days after the acute administration and increased after the daily 3rd day-administration. The excretion of creatinine was similar as that of urine excretion. The excretion of creatinine was increased 5 days after the acute and subacute administration. However, the protein excretion didn't changed in both treatment. Those indicate that SDZ-62-434 might induce the diuresis and also suggest that diuresis might be due to the some metabolites rather than the compound itself. The urinary activities of NAG and LDH were not affected after the acute treatment. However, the urinary activities of AAP and GGT were slightly increased 3 days after the acute administration but, returned to the control value. In subacute treatment, the activities of GGT was not changed. And the activities of NAG were declined after the 7th day-administration. However, the activities of AAP were significantly increased after the 5th day-administration. Furthermore, the urinary activities of LDH were continuously increased during the subacute administration. These results indicate that the high and subacute administration might induce a weak damage on the kidney cells. Furtherrnore, the present results suggest that SDZ-62-434 might have relatively slow-emerging and mild toxicity to the kidney.

• Journal of Preventive Medicine and Public Health
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• v.28 no.2 s.50
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• pp.421-432
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• 1995

The influence of lead exposure on renal function was studied. Eighty nine lead exposed workers who worked in 2 storage battery factories, and seventy one control workers were chosen for this study. Blood lead(PbB) and zinc protoporphyrin in whole blood(ZPP) were selected as indicators of lead exposure. As indicators of renal function, urinary N-acetyl-$\beta$-D-glucosaminidase(NAG), blood urea nitrogen(BUN), serum creatinine(S-Cr), total protein in urine(U-TP),and serum uric acid(S-Ua) were selected. The results obtained were as follows: 1. While the mean values of lead exposure indicators of lead workers were significantly different from non-exposed ones, the mean values of NAG, U-TP, BUN and S-Cr of renal function indicators of exposed were also significantly different from non-exposed but their mean values were all within normal limits. 2. BUN, logarithmic U-TP, logarithmic NAG and S-Cr showed statistically significant correlation with PbB. 3. The proportion of workers whose values of renal function indicators were over the normal limits(NAG7.5 U/g Cr ; U-TP10.9 mg/dl ; BUN20 mg/dl ; S-Crl.2 mg/dl ; S-Ua7.0 mg/dl) by the level of lead absorption in terms of PbB and ZPP were calculated. The proportion of workers with over the normal limits of U-TP among total workers showed the dose-response relationship. When age is adjusted, U-TP showed significantly strong dose-response relationship with the level of PbB and ZPP.

• Childhood Kidney Diseases
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• v.13 no.1
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• pp.56-62
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• 2009

Purpose : The aim of this study was to evaluate the clinical usefulness of measurement of ${\beta}_2$ microglobulin (${\beta}_2$ 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 ${\beta}_$ microglobulin (${\beta}_2$ 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 ($42.3{\pm}27.2\;mg/gCr$ vs $25.2{\pm}10.9\;mg/gCr$, P<0.05). NAG/Cr ratio of spot urine was significantly increased in group II compared group I ($3.70{\pm}23.4\;mg/gCr$ vs $18.7{\pm}12.7\;mg/gCr$, P<0.05). There was no statistically significant difference of ${\beta}_2$ 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.

• Journal of Food Hygiene and Safety
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• v.9 no.3
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• pp.105-109
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• 1994

Lysosomal enzymes might play a most important role in the pathogenesis od diabetic microangiopathy. Some glycosidases, which participate in the catabolism of glycoprotein, are significantly decreased in diabetic mice. In search of new potential lysosomal enzyme inducers, we examined the effects of crude red-ginseng saponin fraction on N-acetyl-$\beta$-D-glucosaminidase, $\beta$-D-galactosidase and $\alpha$-D-mannosidase activities in the liver and kidney of normal and streptozotocin induced diabetic mice. It was found that i.p. administration of ginseng saponin produced the induction of lysosomal enzymes in the kidney more intensively than in the liver. The obtained results suggest the possibility that ginseng saponin might prevent the diabetic microangiopathy.

• Journal of Preventive Medicine and Public Health
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• v.26 no.1 s.41
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• pp.49-64
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• 1993

To provide the basic data for assessment of renal dysfunction related to silicosis, urinary N-acetyl-$\beta$-D-giucobarninidase(NAG) activity known as a sensitive markers for early renal damage were measured in 58 silicosis patients, and control subjects of 40 pulmonary tuberculosis Patients and 51 official workers. The results were summarized as fellows. 1. The values of blood urea nitrogen and serum creatinine in all subjects were within reference limits. But the mean value of urinary NAG activity($7.25{\pm}7.31U/g\;creatinine$) was beyond reference value and more sensitive test than others. 2. The mean value of urinary NAG activity in silicosis group was $11.98{\pm}9.05U/g\;creatinine$ and significantly higher than in tuberculosis and healthy group(p<0.01), but the mean values of NAG activity in tuberculosis and healthy group were not different(p>0.05). 3. The value of NAG activity in tuberculosis had a tendency to be increased according to severity of disease, but that was not significant(p>0.05). The value of NAG activity was increased significantly by use of nephrotoxic antituberculosis drugs(p<0.05). 4. The value of NAG activity in silicosis had a tendecy to be increased according to the size of nodule, use of nephrotoxic antituberculosis drugs and shortness of onset duration, but the increase was not significant(p>0.05). 5. After excluding the users of nephrotoxic antituberculosis drugs, the mean values of NAG activity in healthy control and in tuberculosis control were same as 3.63 U/g creatinine and 3.60 U/g creatinine, respectively. But the mean value of NAG activity in silicosis group was remarkably increased as 10.90 U/g creatinine(p<0.01). As above results, even though there are no abnormal finding in screening renal function test, silicosis can be related with renal dysfunction. And it will be very useful to apply urinary NAG activity in health management of workers exposed to dust.