• Journal of Pharmaceutical Investigation
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• v.26 no.2
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• pp.105-112
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• 1996

The surface of albumin microspheres was modified with methotrexate(MTX) by using 1,3-dicyclohexylcarbodiimide (DCC). Surface-modified albumin microspheres entrapping no MTX (SAMS), free MTX (SAMSF) and MTX-bovine serum albumin(BSA) conjugates(SAMSC) were prepared. The organ-targeting ability of free $[^3H]MTX,\;[^3H]MTX-BSA$ conjugate and the above microspheres was evaluated after i.v. administration of the preparations, equivalent to 150 nCi via the tail vein of mice. The total radioactivity in the lung increased immediately in a few minutes after i.v. injection of the microspheres, and then declined for the period of 3-4 weeks. However, the radioactivity in the liver, spleen and kidney increased slowly during the rapid decrease in radioactivity in the lung. This suggested that the microspheres could be entrapped rapidly in the lung through mechanical filtration because of their large size and slowly redistributed to the liver, spleen and kidney due to either the microspheres being degraded enough for the size to allow passage through the capillary beds of the lung and/or the release of $[^3H]MTX\;or\;[^3H]MTX-BSA$ conjugates from the microspheres. The amount of $60{sim}70%$ of the dose was targeted to the liver after the i.v. injection of SAMS, SAMSF and SAMSC, and the values of $(R_e\;^*\;_{e)liver}$ from the microspheres were $5{\sim}7$ compared to free MTX. This suggested that the liver-targeting ability from surface-modified albumin microspheres could be $5{\sim}7$ times as that of free MTX. The liver-targeted drug was accumulated in the Kupffer cells at the initial stage, thereafter the drug in the Kupffer cell was slowly transferred into the hepatocytes. The value of AUQ for liver from SAMS was higher than that from SAMSF, but much lower than that from SAMSC. This suggest that MTX bound to their surface could be eliminated slower than the entrapped free MTX, and faster than the entrapped MTX-BSA conjugates. This is consistent with the in vitro release rates order in the presence of a proteolytic enzyme. Also, surface-modified MTX was scarcely released in the absence of a proteolytic enzyme. Therefore, the surface-modified MTX nay be released (or eliminated) rapidly from SAMSC at the target site, and thereafter MTX may be released (or eliminated) slowly from the entrapped MTX-BSA conjugates in SAMSC for a long period.

• Korean Journal of Veterinary Research
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• v.37 no.3
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• pp.583-593
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• 1997

Indirect fluorescent antibody test(IFAT) and enzyme-linked imuunosorbent assay (IgG-ELISA) as serological diagnostic tools were conducted to evaluate the usefulness for diagnosis of canine babesiosis infected with Babesia gibsoni in domestic various dog breeds, american pit bullterrier, military shepherd, and mongrel dogs. The results obtained from this study were abstracted as follows. The nonionic detergent Triton X-100 and absorbent bio-bead $SM_2$ were useful reagents for the preparation of pure merozoite antigen of B gibsoni to be used in ELISA. The optimum reaction in ELISA was shown when the protein concentration of ELISA antigen was measured as 625ng/ml and the conjugate concentration was diluted into 1/6000 fold. The average OD value of ELISA in sera determined with negative responses in IFAT was measured as $0.255{\pm}0.051$(490nm) and the cut - off value of OD was determined as 0.399(490nm). The serum antibodies in both of IFAT and ELISA were detected on one week after artificially infected with B gibsoni and these high antibody titers, 512X in IFAT and 1024X in ELISA, were long lasted until 15 weeks after infection. The reproducibility of reaction and stability of the antigen absorbed microtitration polystyrene plate preserved in $4^{\circ}C$ refrigerator and $-20^{\circ}C$ freezer, respectively could be lasted until 135 days after storage. The positive rates in IFAT by dog breeds were shown 8.1%(60/744 heads) in mongrel dogs, 81.3%(78/96 heads) in american pit bullterrier and 15.6%(15/96 heads) in military shepherd, while the positive rate in ELISA shown 17.6%(131/744 heads) in mongrel dogs, 83.3%(80/96 heads) in american pit bullterrier and 36.5%(35/96 heads) in military shepherd, respiectively. In the total of 936 heads surveyed with IFAT and ELISA the positive rates in IFAT and ELISA were 16.4%(153/936 heads) and 26.3%(246/936 heads), respectivily. Agreement of reactions between IFAT and ELISA was shown 82.4% in 936 dog sera. The specificity and sensitivity of ELISA reaction were 83.5% and 76.5%, respectively. From the conclusion obtained in this study it was evaluated that IFAT and ELISA were useful as highly specific, sensitive and stable serelogical tools for the diagnosis of canine babesiosis in Korea.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.3
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• pp.220-226
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• 2017

Dopamine (DA) and serotonin (5-Hydroxytryptamine, 5-HT) are neurotransmitters and hormones that exist in small amounts but have important role in the body. Serum and 24-hour urine are used as specimens, and are usually examined by HPLC-MS. In this study, we tried to detect DA and 5-HT by competitive ELISA using antigen-antibody (Ab) reaction. After immobilizing $5{\mu}g/mL$ BSA conjugate on a 96-well surface, hormone and primary Ab, which are respectively diluted to different concentrations, were treated. Then, HRP-conjugated secondary Ab and TMB were added to measure absorbance. The regression equation and $R^2$ value were calculated based on absorbance, and sensitivity of Ab to hormone as well as the correlation between hormone concentration and absorbance were determined. In DA ELISA, $R^2$, the correlation between the concentration of hormone and absorbance, was the highest by 0.91 when anti-dopamine Ab was diluted 6,000 times and 7,000 times. In 5-HT ELISA, $R^2$ was bigger than 0.90 in every concentration except 3,000 times and 6,000 times. Both DA and 5-HT were not effectively detected at low concentrations (less than $1.0{\times}10^{-7}M$); and because reference value of serum DA is lower than this, HPLC-MS was required to detect serum DA. However, competitive ELISA may be effective in detecting 24-hour urine DA, serum, and 24-hour 5-HT. Further studies are needed to detect hormones more accurately at lower concentrations.

• BMB Reports
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• v.29 no.2
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• pp.105-110
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• 1996

Polyclonal antiserum R101 against aflatoxin $B_1$ ($AFB_1$) was raised in New Zealand white rabbits after injection of bovine serum albumin-$AFB_1$ conjugate. Competitive ELISA (enzyme linked immuno-sorbent assay) demonstrated that antiserum R101 has the highest binding for $AFB_1$ (50% inhibition at 170 fmol) and aflatoxicol II (50% inhibition at 112 fmol). It also reacts with other aflatoxins such as $AFB_2$, $AFG_1$, $AFG_2$, and aflatoxin metabolites ($AFM_1$, $AFM_2$, $AFP_1$, and $AFQ_1$), but it does not cross-react with $AFG_2a$. Using this antiserum, aflatoxins were quantitated in 100 urine samples of undergraduate students at the College of Pharmacy, Sung Kyun Kwan University, Republic of Korea. By ELISA, $AFB_1$ and its metabolites were detected in human urine samples (N=100, male=89, female=11, ages=20~31 yrs) with a range of 1.4~200.6 ng/kg/day (mean$\pm$SD=$18.11{\pm}33.01\;ng\;AFB_1/kg/day$ in males, $3.82{\pm}2.65\;ng/kg/day$ in females). Assuming that urinary excretion is about 7.6% of $AFB_1$ intake (Groopman et al., 1992), we estimated that Koreans were daily exposed to a total dietary $AFB_1$ of $240.20{\pm}438.67\;ng/kg/day$ in males and $50.35{\pm}29.88\;ng/kg/day$ in females, respectively. When the human monitoring data was applied to a linear regression model of Y=21.67X-10.04 {Y=liver cancer incidence per 100,000, X=Log $AFB_1$ intake (ng/kg/day), r=0.99} developed from previously reported epidemiological data, calculated liver cancer incidences attributed to $AFB_1$ exposure were 41.56/100,000 in males and 26.84/100,000 in females. The incidences were similarly correlated with liver cancer mortality rates of 43.43/100,000 in males and 11.23/100,000 in females in Korea. These results suggest that aflatoxin exposure may be an important risk factor for the high incidence of liver cancer in Korea.

• Parasites, Hosts and Diseases
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• v.23 no.1
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• pp.95-101
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• 1985

Fascioliasis in cattle is one of the most common and very serious trematode diseases in Korea. In the present study, the enzyme linked immunosorbent assay (ELISA) was applied in the diagnosis of fascioliasis using antigen of Fasciela hepatica, perokidase of conjugate anti-cattle Is G and orthophenylenediamine as a substrate by micro-method technique of Volley et at. (1976b) and MacLaren (1978) with a slight modification. Results obtained from the present study are as follows. 1. In assay for optimal dilution of stock antigen, the antigen (protein contents; 0. Bmgymz) was diluted from 1150 to 1/600 with carbonate buffer (pH 9.6), and then absorbance values were measured with 1/100 diluted sera. The regression equations between the OD values of ELISA and dilution of antigen were log Y: -0.181-0.00127X in infected sera, and log Y: -0.578-0. 000879X in normal sera. The significantly higher (p<0.05) OD value was observed in the former. 2. In assay for optimal dilution of sera, the sera were diluted from 1125 to 1/400 with in PBSJ Tween 20 (pH 7.4), and absorbance values were measured with 1/200 diluted antigen. The regression equation between the OD values of ELISA and dilution of sera were log Y: -0.1540-0.0007238X in infected sera and log Y: -0.4834-0.00116X in normal sera. The former was higher than the latter (p<0.05). 3. In the 27 cases of negative intradermal test, OD values of the ELISA are $0.447{\pm}0.144$, the 95% confidence interval (Mean+2 H SD) of the values was 0.735, and there was no case over the values. Therefore, the sensitivity of the antigen to diagnose fascioliasis was 100% in the negative case. The OD value 0.7 which is designed as a criterion (detection level of positive one) is useful for the performance of the ELISA in fascioliasis. 4. According to the OD value of criterion in the regression equations, the optimal dilutions of stock antigen and serum were 1/250 and 1/100, respectively. 5. In the 58 cases of fascioliasis from which the adult could be found in the bile ducts, the OD value was $0.846{\pm}0.224$. The 75% (44 cattle) among them had higher value with compared to the criterion, and the 60% (20 cattle) of the cases of proliferative cholangitis of 33 cattle which had been infected previousely with Fasciola sp. is higher than the criterion. 6. Prevalence of fascioliasis was 43.4% in the application of the ELISA to 272 cattle which were reared in Jeonbug district.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.176-182
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• 2006

Sensitive and specific monoclonal antibody (MAb) was produced from hybridoma (1H11-5) obtained by fusion of myeloma cell (V653) and spleen cell isolated from mouse immunized sulfamthazine (SMZ)-HG-KLH. Direct competitive ELISA was developed for rapid detection of SMZ in milk samples using MAb against SMZ with optimized conditions between MAb and SMZ-HG-HRP conjugate, and applicable conditions for analysis of milk samples were established. Detection range of immunoassay was 0.1 to 100 ppb. Recoveries from spiked raw milk and processed milk samples averaged 82.1-120.7 and 82.1-97.1%, respectively.

• Korean Journal of Weed Science
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• v.18 no.2
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• pp.161-170
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• 1998

Antagonistic mode of action of fenoxaprop-P-ethyl [ethyl(R)2-4-{(6-chloro-2-benzoxazolyloxy) phenoxy}propionate] with bentazon was investigated with respect to absorption, translocation, metabolism, and change in target site response of fenoxaprop-P-ethyl using four-leaf stage of rice(Oryza sativa L.) and barnyardgrass [Echinochloa eras-galli (L.) P. Beauv.]. Shoots of rice and barnyardgrass was more sensitive to fenoxaprop-P-ethyl than the roots. More than 90% of fenoxaprop-P-ethyl was absorbed within 6 hours after treatment and 30% of the absorbed was acropetally and basipetally translocated at 24 hours after treatment. Fenoxaprop-P-ethyl was rapidly transformed to its acid form, fenoxaprop(2-[4-(6-chloro-2-benzoxazolyloxy)phenoxy]propionic acid), which was subsequently metabolized to polar conjugates. However, changes in absorption, translocation, and metabolism of fenoxaprop-P-ethyl by bentazon treatment were not found in both species. Background activity of acetyl-CoA carboxylase(ACCase) in rice and barnyardgrass was 26.5 and 23.2nmol/min/mg, respectively. Concentration required to inhibit fifty percent enzyme activity$(I_{50})$ in vitro was 6.5~7.4${\mu}M$ of fenoxaprop-P-ethyl and more than 500${\mu}M$ of bentazon. There were no significant differences in $I_{50}$ value between two treatments of fenoxaprop-P-ethyl alone and its bentazon mixture. However, bentazon reduced ACCase activity in vivo and inhibited electron transport in chloroplast thylakoid. Based on the results obtained, it is concluded that the antagonistic effect of bentazon occurs due not to direct effect on target site of fenoxaprop-P-ethyl, but to indirect involvement in reducing herbicidal activity of fenoxaprop-P-ethyl through physiological disturbances caused by bentazone at whole chloroplast level.

• Applied Chemistry for Engineering
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• v.35 no.2
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• pp.67-78
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• 2024

Light absorption has potential as a signal in biochemical analyses due to its simplicity in measurement and interpretational clarity. Among substances that generate absorption signals, gold nanoparticles possess advantages such as chemical stability, biological compatibility, and unique optical properties from the localized surface plasmon resonance (LSPR) in the visible light range. They also exhibit versatility compared to other colorimetric substances effective only for specific target molecules, as they easily conjugate with various detection active substances like antibodies and aptamers. Particularly due to advantages such as low cost, ease of particle synthesis, and high environmental stability compared to enzyme-based colorimetric methods, gold nanoparticles are extensively researched as signal substances in colorimetric assays. This review summarizes various strategies utilizing gold nanoparticles as absorption signal substances, focusing on recent research. Based on the characteristics of gold nanoparticles, where the optical property is influenced by particle morphology, literature is classified and reviewed based on strategies controlling the shape of gold nanoparticles during signal generation. Through this, it is observed that gold nanoparticles, which have been used as absorption signal substances, continue to be actively researched, affirming their potential for broad and continuous improvement in the future.

• Journal of Applied Biological Chemistry
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• v.54 no.3
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• pp.206-213
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• 2011

Hepatoprotective effects of Monascus pilosus mycelial ethanol extract (MPME) were examined in high-fat diet induced-obese rats. The rats were randomly divided into 2 groups; normal control (NC) and a high-fat and high cholesterol diet group (HFC). The HFC diet group was fed a 5L79 diet supplemented with 15% lard and 1% cholesterol for 3 weeks for induction of obesity. And then, the rats were divided into 4 groups (n=5); the NC, a HFC diet obesity control group (HF), 0.5% MPME supplemented HFC diet group (MPM), and 2% conjugated linoleic acid (CLA) supplemented HFC diet group for 7 weeks. Whereas the daily weight gain of NC and HFC groups were 3.48 g and 4.48 g, respectively, those of MPM and CLA were 3.09 g and 4.38 g, respectively. Furthermore, activity of serum alanine and aspartic aminotransferase in HF was markedly higher than those of NC group, but, the activity in MPM and CLA was significantly lower than HF. Hepatic reduced glutathione content in MPM and CLA was higher than HF. On the contrary, hepatic lipid peroxide content in MPM and CLA was significantly lower than HF. In conclusion, although the precise mechanisms of the hepatoprotective effects of the MPME in this study are unknown, our study provides experimental evidence that MPME may prevent obesity and hepatic damage by high-fat and high cholesterol diet via inhibition of lipid absorption and induction of reactive oxygen spices scavenging enzyme such as superoxide dismutase.