• Journal of environmental and Sanitary engineering
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• v.3 no.2 s.5
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• pp.61-78
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• 1988

This study was carried out to clarify the effect of dietary calcium, casein and suet on intestinal absorption of cadmium in mice. It was performed for 30 days, from April 11, to May 10, 1988. Ninety mice were devided into 4 experimental groups and control group with 6 mice each dietary group, and measured survival ratio, body weight and weight ratio of organ to body. The contents of cadmium in liver, kidney, spleen, muscle and skin with hair, and feces were analyzed by atomic absorption spectrophotometer after sacrifice by anesthesia. The ratio of survival after 30 day breeding was $100\%$ in control group, but $66.7\%$ in group IV(basal diet + Cd + Ca) with $100{\mu}g$ one dose and with 50ppm cadmium containing fluid free-intake, and group V (basal diet + Cd + suet) with free-intake of 50ppm containing cadmium fluid. The ratio of body weight gains in cases of single dose $100{\mu}g$ of cadmium was highest as $42.3\%$ in group IV and lowest as $26.0\%$ in group V, in cases of free-intake of 50ppm containing cadmium fluid was highest as $24.0\%$ in group IV and lowest as $11.6\%$ in group II (basal diet + Cd). The body weight, in the case of single dose of $100{\mu}g$ of cadmium showed no increase untill 5th day from acute poisoning. While in case of free-intake of 50ppm containing cadmium, it showed very slight increase through all breeding period. The weight ratio of organ to body were lowest in liver of group II in both occasions. The most of cadmium administered was excreated in feces within 2 days after single dose $100{\mu}g$ cadmium. The contents of cadmium in all tissues were significantly high in each group comparing to control group as liver, kidney, spleen and muscle of group II which showed the highest level in both occasions of $100{\mu}g$ one dose and free-intake of 50ppm containing cadmium fluid, and higher in group II of the occasion with $100{\mu}g$ single dose, and in group V of the occasion of 50ppm containing cadmium fluid free-inatke for skin with hair. And the content of cadmium in tissues is generally higher in the occasion of 50ppm containing cadmium free-intake than $100{\mu}g$ single dose. From the above results I conclude that the addition of casein, calcium and suet in cadmium containing diet is effective to inhibtion of intestinal absorption of cadmium by particularly, calcium.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.149-155
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• 1997

This study was carried out to investigate the effects of phenobarbital sodium(PB) and 3-methylcholanthrene(3-MC) on carbofuran cytotoxicity and to develop antitoxic agents based on the effectivness. Experimental groups for carbofuran cytotoxicity were divided into five groups ; medium alone and four treatments of carbofuran (1, 25, 50 and $100{\mu}M)$, and those for compensation effects were divided into six groups ; medium alone, $IC_{50}$ carbofuran and four combinations of carbofuran and PB or 3-MC($IC_{50}$ carbofuran plus 1, 25, 50, $100{\mu}M$ of PB and 3-MC, respectively). After incubation for 48 hrs under the same conditions, MTT(Tetrazolium MTT), NR(Neutral red) and SRB(Sulforhodamine B protein) assay were performed. Fifty percentage inhibition of MTT, NR, and SRB against carbofuran in rat fibroblast cell were 60.7, 82.5 and $87.0{\mu}M$, respectively. At the combination treatments of $IC_{50}$ of carbofuran and $100{\mu}M$ of PB, the significant compensation effects were observed from the results of MTT and NR but not from that of SRB absorbance. And at the combination treatments of $IC_{50}$ of carbofuran and 3-MC, the relatively significant compensation effects were found at $50{\mu}M$ 3-MC from the results of MTT and at $100{\mu}M$ 3-MC from that of NR and SRB absorbances, respectively. From the results of light microscopy, combination treatments of $carbofuran(IC_{50})$ and PB or 3-MC showed good regeneration in carbofuran toxicity of rat fibroblast cells. These results suggest that PB or 3-MC can compensate the cytotoxity of carbofuran insecticide in rat NIH3T3 fibroblast cells.

• Korean Journal of Poultry Science
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• v.18 no.3
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• pp.183-196
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• 1991

In order to establish ELISA method to detect antibody against IBV various factors involved were examined. Antigen was prepared from Massachusetts type IBV which is known to be one of serotypes distributed most widely. The virus was grown in embryonated SPF chicken eggs. Allantoic fluid harvested was processed to ultracentrifugation and sucrose density gradient centrifugation to produce a purified antigen The antisera selected from the field samples based on hemagglutination inhibition test were used as the standard positive and negative sera for this study and the results obtained were summarized as follows. 1 , It was found that ELISA test was satisfactory when the purified antigen was coated on the plate in the amount of about 40ng protein per well. In case of the phospholipase treated hemagglutinating antigen it gave satisfactory results when the each well wns coated with 1.2 to 2.5 hemagglutinating unit which was equivalent to 40 to 90ng of protein. 2. There was no significant difference in the ratio of optical density of positive to that of negative serum whether the coated antigen was held for 1 hour at 37$^{\circ}C$ or it was held overnight at 4$^{\circ}C$. The coated antigen could be kept in dried state without change of antigenecity for at least one month of experimental period at 4$^{\circ}C$. 3. There was a big variation in the optical density and P/N values depending on the maker of the plates and on the plate of the same maker. 4. It was found that background optical density was negligible when serum was diluted more than 1：50 and serum dilution of 1：100 appeared to be appropriate as a routine test dilution to screen the antibody. 5. Optical density was fairly constant 15 minutes afterward from the time substrate was treated and during the 4 hours after stopper was treated. 6. There was a low correlation(r＝0.42) between ELISA and HI test. However, when 74serum samples were tested for the IBV antibody, 98.7% were found to be positive by both tests in which titers of 2$^{6}$ or more by HI test and P/N values of 1.4 or more by ELISA were considered to be positive, 7 Day-old IBV vaccinated chickens shows a similar antibody decay and rising pattern until 8 weeks of age by the two tests, ELISA and HI.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.1
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• pp.78-90
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• 1993

This study was designed obtain and early detection the workers exposed to excessive copper dust and also to present biological exposure index. The exposed group consisted of 62 male workers at the metallurgy workplaces. To evaluate the degree of individual exposure the copper dust, each personal air sampling was collected. Biological exposures in the exposed group was quantified for the blood and urine copper levels using flameless atomic absorption spectrophotometer. The control group consisted of 70 male adults with the history of nonexposure to copper by the inhalation occupationally. The average concentration of copper in blood and urine of the exposed group was $49.44{\pm}8.90(29.05-80.63){\mu}g/dl$, $39.99{\pm}11.04(29.62-80.63){\mu}g/l$ respectively. The average concentration of air borne copper was $0.48{\pm}0.31(0.03-1.18)mg/m^3$. The average concentration of blood and urine copper in the control group was $42.93{\pm}5.84(25.05-57.85){\mu}g/dl$, $33.02{\pm}13.38(12.00-82.05){\mu}g/l$ respectively. The difference observed in the average concentration of blood and urine copper of the exposed and control groups was statistically significant seperately (blood copper, p<0.05 ; urine copper, p<0.05). The relationship between the individual exposure concentration of air borne copper and the concentration of the blood and urine copper was statistically significant, respectively (blood copper, r=0.54, p<0.05 ; urine copper, r=0.37, p<0.05). The relationship between the working duration and the concentration of blood and urine was not statistically significant respectively (blood copper, r=0.14 ; urine copper, r=0.12). The relationship between the age and the concentration of blood and urine copper was statistically not significant respectively (blood copper, r=013 ; urine copper, r=-0.06). The relationship between blood and urine copper concentration in the exposed group was statistically significant (r=0.62, p<0.05), and the relationship between blood and urine copper concentration in the control group was also statistically significant (r=0.39, p<0.05).

• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.83-91
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• 2018

Advances in bacterial and fungal genome mining uncover a plethora of cryptic secondary metabolite biosynthetic gene clusters. Guided by the genome information, targeted transcriptional derepression could be employed to determine the product of a cryptic gene cluster and to explore its biological role. Monascus spp. are food grade filamentous fungi popular in eastern Asia and several genome data belong to them are now available. We achieved transcription activation of a cryptic fungal polyketide synthase-nonribosomal peptide synthase gene Mpfus1 in Monascus purpureus ${\Delta}MpPKS5$ by inserting Aspergillus gpdA promoter at the upstream of Mpfus1 through double crossover gene replacement. The gene cluster with Mpfus1 show a high similarity to those for the biosynthesis of conjugated polyene derivatives with 2-pyrrolidone ring and the mycotoxin fusarin is the representative member of this group. The ${\Delta}MpPKS5$ is incapable of producing azaphilone pigment, providing an excellent background to identify chromogenic and UV-absorbing compounds. Activation of Mpfus1 resulted in a yellow hue on mycelia and its methanol extract exhibit a maximum absorption at 365 nm. HPLC analysis of the organic extracts indicated the presence of a variety of yellow compounds in the extract. This implies that the product of MpFus1 is metabolically or chemically unstable. LC-MS analysis guided us to predict the MpFus1 product and to propose that the Mpfus1-containing gene cluster encode the biosynthesis of a desmethyl analogue of fusarin. This study showcases the genome mining in Monascus and the possibility to unveil new biological activities embedded in it.

• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.146-152
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• 2005

The objective of present study was to investigate the effect of onion extracts on mercuryinduced cytotoxicity, lipid peroxidation and antioxidant enzyme activities in primary monolayer cultures of rat hepatocytes. Primary cultures of rat hepatocytes were incubated for 6 hr in the presence of various concentrations (0, 1, 5, 10, 30 or 50 ppm) of $HgCl_2$. Cytotoxicity and cell viability were determined by measuring glutamic oxaloacetic transaminase (GOT) activity, lactate dehydrogenase (LDH) activity and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) value. Lipid peroxidation w as evaluated using thiobarbituric acid reactive substances (TBARS) assay. Effects of onion extract on antioxidant system were determined by measuring catalase, glutathione peroxidase (GSH-Px), glutathione reductase (GSH-Rd) activities as well as DPPH free radical scavenging activity. $HgCl_2$ at the concentration of 10 ppm increased GOT activity and TBARS concentration but decreased %MTT reduction, whereas $HgCl_2$ at the concentration of 30 ppm increased LDH activity, representing that $HgCl_2$ caused cytotoxicity and lipid peroxidation in dose-dependent manner, $HgCl_2$ at the concentration of 30 ppm significantly decreased catalase, GSH-Px and GSH-Rd activities. When primary cultures of rat hepatocytes were incubated with various concentrations (0, 0.01, 0.05, 0.1 or 0.3 mg/ml) of onion extract for 6 hr in the presence of 30 ppm of $HgCl_2$, onion extracts at the concentration of 0.05 mg/ml decreased GOT activity, but increased %MTT reduction by 30 ppm of $HgCl_2$. $HgCl_2-induced$ LDH activity and TBARS concentration were decreased by onion extract at the concentration of 0.01 mg/ml. Taken together, onion extract prevented H$HgCl_2-induced$ hepatocyte injury and lipid peroxidation. Onion extracts at the concentration of 0.1 mg/ml almost or completely inhibited $HgCl_2-induced$ catalase and GSB-Px activities. GSH-Rd activity, however, was not affected by onion extract. Free radical scavengjing activity was increased as concentration of onion extract increased. Onion extract at the concentrion of 5 mg/ml possesed mote than 93% scavenging activity comparing to 100% radical scavenging activity by pyrogallol solution as a reference. These results demonstrate that onion extracts suppressed mercury-induced cytoctoxicity and lipid peroxidation by scavenging free radical and increasing catalase and GSH-Px activities.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.4
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• pp.278-286
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• 2009

In this study, four natural Mn oxides ($NMO_1-NMO_4$) was characterized using x-ray diffraction, scanning electron microscopy, and their removal efficiency for 1-naphthol (1-NP) in aqueous phase, using batch reactor, was investigated. The results were compared with one another and a synthetic manganese oxide, birnessite. The NMOs have a various Mn minerals including pyrolusite (${\beta}-MnO_2$), cryptomeltane (${\alpha}-MnO_2$) as well as birnessite (${\delta}-MnO_2$) depending on their sources, which results in different removal efficiencies (removals, kinetics) and reaction types (sorption or oxidative-transformation). The comparative study showed that $NMO_1$ (electrolytic Mn oxide) have a higher removal efficiency for 1-NP via oxidative-transformation compared to birnessite. The 1-NP removals by NMOs were followed by pseudo-first order reaction, and the surface area-normalized specific rate constants ($K_{surf},\;L/m^2$ min) determined were in order of $NMO_1(3.31{\times}10^{-3})$>${\delta}-MnO_2(1.48{\times}10^{-3}){\fallingdotseq}NMO_3(1.46{\times}10^{-3})$>$NMO_2(0.83{\times}10^{-3})$>$NMO_4(0.67{\times}10^{-3})$. From the solvent extraction experiments with the Mn oxide precipitates after reaction, it was observed that the oxidative-transformation rates of 1-NP were in order of $NMO_1{\fallingdotseq}{\delta}-MnO_2$>$NMO_3$>$NMO_4{\gg}NMO_2$ and the analysis of HPLC chromatogram and UV-Vis. absorption ratios ($A_{2/4}$, $A_{2/6}$) on the supernatant confirmed that the reaction products were oligomers formed by oxidative-coupling reaction. Results from this study proved that natural Mn oxide (except $NMO_2$) used in this experiment can be effectively applied for the removal of naphthols in aqueous phase, and the removal efficiencies are depending on the surface characters of the Mn oxides.

• The Korean Journal of Pesticide Science
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• v.18 no.2
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• pp.79-87
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• 2014

Pyriofenone is an aryl phenyl ketone fungicide that is newly registered in Korea in 2013 to control powdery mildew on food. The objective of this study was to develop reliable and sensitive analytical method for determination of pyriofenone residue in agricultural products for ensuring the food safety. The pyriofenone residues in all samples(Korean melon, pepper, potato, mandarin, soybean, and hulled rice) were extracted with acetonitrile, partitioned with dichloromethane, and then purified with a silica cartridge. The purified samples were analyzed by HPLC-UVD and confirmed with LC-MS. The linear range of pyriofenone was 0.05~5 mg/kg with the correlation coefficient ($r^2$) > 0.999. Average recoveries of pyriofenone ranged from 72.8% to 99.5% at the spiked level of 0.05 and 0.5 mg/kg, while the relative standard deviation was 2.3%~6.4%. In addition, the limit of detection and limit of quantification were 0.01 and 0.05 mg/kg, respectively. The results revealed that the developed and validated analytical method was suitable for pyriofenone determination in agricultural products.

• Applied Biological Chemistry
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• v.29 no.2
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• pp.130-137
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• 1986

The five fish meal kojis which contained various ratios of barley were prepared and processed to produce six different fish-soy sauces. The chemical compositions including enzyme activities during fermentation were determined and sensory evaluation was done and changes of absorbance during heating process were also measured. The contents of reducing sugar increased until 12 hours, then slightly decreased and maintained constant level after 36 hours during koji making. The contents of total nitrogen were proportional to the amount of fish meal used in koji. The activities of amylase and protease were increased until 48 hours and then were not changed during koji making. The contents of reducing sugar were increased until 50 days and then were not much changed during koji making. The contents of nitrogen and amino nitrogen in sauces were increased gradually during fermentation. The total acid contents of sauces were increased until 70 days, after which it was constant during fermentation. The absorbances of sauces were increased with time during heating process. In sensory test, the fish-soy sauce the ratio of fish meal: barley of which was 10 : 16 received the highest score for flavor of sauce and the conventional soy sauce, for color and taste in a soup test. Fish-soy sauce resulted good quality when the ratio of fish meal to barley was 10 to 13 and 10 to 16.

• Microbiology and Biotechnology Letters
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• v.14 no.6
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• pp.495-500
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• 1986

Enzymatic micro-assay methods were studied those were capable of determining ammonia down to 10$^{-5}$M(0.01 $\mu$mole/ml) in the presence of other nitrogenous compounds such as protein and amino acid. Microquantities of ammonia (0.01-0.1 $\mu$mole) could be determined indirectly by measuring phosphorous, one of the products of the enzymatic reaction catalyzed by glutamine synthetase. In this reaction, L-glutamate, ATP and ammonium chloride were used as substrates, and phosphorous was formed in propotion to the concentration of ammonium chloride In the reaction mixture. Another procedure was examined in which glutamine synthetase reaction coupled with pyruvate kinase and lactate dehydrogenase reactions was used. One mililiter of the assay mixture contained; phosphoenol pyruvate, 3 mM, L-glutamate, 10 mM; ATP, 1mM: MgSO$_4$, 20 mM: KCl, 75mM: NADH, 0.2mM: Tris-HCl buffer(pH 7.0), 100mM; pyruvate kinase, 10 U: lactate dehydrogenase, 12 U and glutamine synthetase, 4 U. After preincubation for 20 min at 3$0^{\circ}C$, NH$_4$Cl was added and the rates of NADH oxidation were followed at 340nm. The effective range of this method was proved to be from 0.01 to 0.05 $\mu$mole/$m{\ell}$. Glutamine synthetase reaction coupled with glutamate synthase reaction could also be effectively used for determining microquantities of ammonia. The one mililiter assay mixture contained; ATP, 5mM: L-glutamate, 5mM; L-ketoglutarate, 5mM; MgCl$_2$, 15mM; NADPH, 0.15mM; Tris-HCl buffer(pH 7.0); 100mM; glutamine synthetase, 1U and glutamate synthase, 0.5U. After preincubation for 20min at 3$0^{\circ}C$ NH$_4$Cl was added and the rates of NADPH oxidation were followed at 340nm. The effective range of this procedure was appeared to be from 0.01 to 0.05$\mu$mole/$m{\ell}$.