• Korean Chemical Engineering Research
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• v.49 no.4
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• pp.387-392
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• 2011

Enzymes are being used in various fields due to their unique property of substrate specificity. Enzyme-linked immunosorbent assay(ELISA) has enabled the detection of various antigens by reporting the binding event of antigen and antibody via enzyme-catalyzed reaction. However, the sensitivity improvement of conventional ELISA has been limited because only one enzyme molecule is conjugated to one molecule of antibody. To overcome this limitation and further improve the sensitivity of ELISA, there have been efforts to increase the number ratio of enzymes to antibody. Recently, the nanobiocatalytic approaches, with their successful enzyme stabilization, improved the performance stability as well as sensitivity in a modified protocol of ELISA. The present paper introduces the basic principle of ELISA, and the recent efforts to improve sensitivity and performance stability of ELISA by using the nanobiocatalytic approaches.

• Korean Journal of Agricultural Science
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• v.39 no.4
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• pp.613-618
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• 2012

This study was performed to optimize the basic platform of a lateral flow immunoassay. Improvement of the limit of detection (LOD) was evaluated according to the width of a nitrocellulose membrane with varying concentrations of analyte. The analyte, neutravidin was detected based on the avidin-biotin interaction. The antibody-Au nanoparticle conjugation was mostly stabled in a PBS buffer of pH 7.3. The optimal widths of a nitrocellulose membrane were 4 and 6 mm considering the sample flow rate and signal strength of the test line on the membrane. The LOD of neutravidin was 0.001 mg/ml in the optimum conditions.

• Korean Journal of Biological Psychiatry
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• v.13 no.4
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• pp.273-278
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• 2006

Objectives : Biochemical markers can provide an objective evidence of heavy alcohol drinking. The purpose of this study was to compare and evaluate the usefulness of biological markers detecting alcohol dependence, such as mean corpuscular volume(MCV), gamma-glutamyl transferase(GGT), and carbohydrate-deficient transferrin(CDT) in the patients of an alcohol counseling center. Methods : This study was done with 64 patients with alcohol dependence and 36 healthy subjects. Relative values(%) of CDT were determined in their sera with turbidimetric immunoassay(Bio-Rad %CDT assay, Axis-Shield ASA, Oslo, Norway), and were compared with conventional markers of alcohol consumption, GGT and MCV. Results : Among the patients with alcohol dependence, 78.1% showed abnormal %CDT levels compared with GGT(61.9%) and MCV(20.7%). The areas under the receiver operating characteristic(ROC) curves(95% confidence interval) for %CDT, GGT, and MCV were 0.934(0.866-0.973), 0.871(0.789-0.930), and 0.575 (0.472-0.673), respectively. Conclusion : %CDT seems to be the most reliable biological marker for the detection and monitoring of alcohol consumption in the patients with alcohol dependence of the alcohol counseling center.

• Korean Journal of Biological Psychiatry
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• v.3 no.1
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• pp.109-114
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• 1996

We have previously reported that Korean schizophrenic patients hove low production of IL-2 in vitro suggestive of autoimmunity to the pathogenesis of the disorder. In an attempt to further explore this issue, we measured in vivo serum levels of interleukins(IL-$1{\beta}$, IL-2, and IL-6) using a quantitative "sandwich" enzyme immunoassay(ELISA) in 26 male schizophrenic patients and in 26 age-matched normal controls. Patients met DSM-IV criteria for schizophrenia and were drug free for at least six months. The severity of symptoms was assessed by SANS and SAPS. We found a significant increase of IL-2 level(p<0.05) in schizophrenic patients as compared with normal controls. There were significant positive correlations between IL-2, IL-6 levels and negative symptom scores. There were no correlations between age, age at onset, duration of illness and interleukin levels. Our results may support the hypothesis of viral-autoimmune dysfunction in schizophrenia. IL-2 or IL-6 may be associated with specific clinical feature in schizophrenic syndrome, especially negative symptom.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.641-648
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• 2009

A one-step simultaneous immunchromatographic (OS-ICG) assay using colloidal gold-monoclonal antibody (gold-MAb) conjugates was developed for the rapid multianalysis of aflatoxin B1 (AFB1) and ochratoxin A (OTA) in feed samples. Visual detection limits for AFB1 and OTA were 0.5 and 2.5 ng/mL, respectively, and the results were obtained within 15 min. Matrix interference from the feed extracts was efficiently reduced by appropriate dilution with buffer. Cut-off values of the OS-ICG assay for the feed spiked with AFB1/OTA mixtures (5/5, 10/10, 25/25, 50/55, 100/100 ${\mu}g/kg$) were 10 and 50 ${\mu}g/kg$ for AFB1 and OTA. The comparative analyses of 65 feed samples by OS-ICG, enzyme-linked immunosorbent assay (ELISA), and high performance liquid chromatography (HPLC) showed good agreement. In this study, we confirmed that simultaneous analysis based on immunoassay is possible and it can be used as an on-site multianalysis of AFB1 and OTA in feed, food, and agricultural products.

• Korean Journal of Clinical Laboratory Science
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• v.41 no.4
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• pp.173-179
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• 2009

The analysis of serum free light chains (sFLCs) can improve the diagnosis and monitoring of multiple myeloma and other plasma cell dyscrasias. As with other immunoassays, sFLCstests are subject to potential antigen excess and heterophilic antibody interference. We describe 9 cases of sFLCs antigen excess in patients with multiple myeloma using the FreeliteTM Human Kappa and Lambda Free Kits (The Binding Site ltd., Birmingham, UK) and the Hitachi7600 P module turbidimetric system. A total of 1,247 consecutive samples from 250 patients with multiple myeloma were assayed for sFLCs from April to September, 2009. The samples were assayed using an initial dilution of 1 :5and subsequent dilutions of 1 :50 and 1: 100. The same samples were analyzed for the presence of monoclonal gammopathies using serum protein electrophoresis (SPE) and immunofixation electrophoresis (IFE). There were 9 samples (0.72%) of antigen excess with 3 cases of kappa (0.24%) and 6 cases of lambda (0.48%). These cases represents an example of antigen excess or "hook effect" using the serum free light chain assays and mandates high level of attention to falsely low sFLC levels due to antigen excess, especially when it is disaccordant to other assay results or clinical manifestations.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.4
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• pp.961-966
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• 2007

Lesser yang person-Hyungbangpaedok-san (HBPDS) is a prescription originated in the

• KSBB Journal
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• v.10 no.3
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• pp.271-282
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• 1995

The authentic hGH converted from met-hGH by immobilized ApM was purified by successive chromatographic processes based on the differences in isoelectric points, hydrophobicities and charges. The final recovery yield was about 14.1% and the specific activity of the purified hGH was 2.75IU per mg when assayed by enzyme immunoassay. The purified hGH was verified to be authentic hGH through the analysis of amino acid composition, amino-terminal amino acid sequence, carboxy-terminal amino acid and tryptic peptide map. The purity of purified hGH was higher than that of commercial hGH when assessed by SDS-PAGE, PAGE, IEF and HSGF. In weight-gain assay and tibia test with hypophysectomized rats, the hGH produced in this study showed the same growth effect as the commercial hGH.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.4
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• pp.1051-1056
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• 2006

Rehmanniae radix preparata is the root of Rehmanniae glutinosa Liboschitz var. purpurea Makino which has been classified into Scrophulariaceae. Rehmanniae radix preparata has been used for the treatment of diabetes, for the relief of the pain, and for the anti-oxidative action. In this study, the effect of the aqueous extract of Rehmanniae radix preparata on lipopolysaccharide-induced inflammation was investigated by using 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, reverse transcription-polymerase chain reaction (RT-PCR), Western blot, prostaglandin E2 immunoassay, and nitric oxide (NO) detection in mouse BV2 microglial cells. In the present results, the aqueous extract of Rehmanniae radix preparata suppressed prostaglandin E2 (PGE2) synthesis and nitric oxide production by inhibiting the lipopolysaccharide-stimulated expressions of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) mRNA and protein in mouse BV2 cells. These results show that Rehmanniae radix preparata exerts anti-inflammatory effect probably by suppressing of COX-2 and iNOS expressions.

• Molecular & Cellular Toxicology
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• v.2 no.1
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• pp.67-73
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• 2006

In previous studies, it has been discovered that cancer cells not only overexpress regulatory subunit I (Rl)/protein kinase type I (PKA-I) but also secrete outside the cell an extracellular form of PKA (ECPKA) and that the ECPKA secretion detected in patients' serum is obviously greater than that found in non-cancer patients or healthy subjects. We now found that ECPKA elicits the formation of serum autoantibodies that can serve as a cancer diagnostic and prognostic marker. To measure the presence of anti-ECPKA autoantibody in the human sera, basic methodology for ECPKA assay was established an enzyme-linked immunosorbent assay (ELISA). We obtained serum samples from 199 patients with different types of cancer, and also obtained 31 serum samples to compare with ECPKA concentrations from non-cancer patients and 119 normal volunteers. Compared with normal or non-cancer patient sera, we found that the frequency of anti-ECPKA autoantibody was significantly higher in cancer patients (88%) than in those without cancer (17%). Furthermore the presence of anti-ECPKA autoantibodies in the serum of cancer patients was highly correlated with the site of metastasis. The immunoassay developed for anti-ECPKA antibodies is highly sensitive and specific. Therefore, this discovery of an autoantibody-based cancer diagnostic may have serious clinical application and may become an important advance over current technology.