• Biomedical Science Letters
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• v.15 no.2
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• pp.161-166
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• 2009

Human erythropoietin(EPO) is a glycoprotein that enhances red blood cell production by stimulating proliferation and differentiation of erythroid progenitor cells in the bone marrow. Patients with chronic kidney disease(CKD) suffer from anemia caused by reduced production of EPO in the kidney. Recombinant human EPO protein has been used successfully for the treatment of anemia associated with CKD. Recently, attention has been paid to the development of side effect of EPO, pure red cell aplasia(PRCA), in some patients with CKD. PRCA is a rare disorder of erythropoiesis that leads to a severe anemia due to an almost complete cessation of red blood cell production. EPO-related PRCA is caused by the production of EPO-neutralizing antibodies(Abs) that eliminate the biological activity of EPO as well as endogenous EPO in patients undergoing therapy. Since 1988, almost 200 cases worldwide have been reported with Ab-positive PRCA after receiving EPO therapeutics. The underlying mechanisms of the breaking of immune tolerance to self-EPO have been investigated. Modification of formulation, organic compounds of container closures, and route of administration has been suggested for the possible mechanism of increased immunogenicity of EPO. A number of assays have been used to detect Abs specific to EPO. These assays are generally grouped into two major categories: binding Ab assays and neutralizing Ab assays(bioassays). There are several types of binding Ab assays, including radioimmunoprecipitation assay, enzyme-linked immunosorbent assay, and the BIAcore biosensor assay. In vitro cell-based bioassays have been utilized for the detection of neutralizing Abs. Finally, the recent experience with anti-EPO Abs may have considerable implications for the future development and approval of EPO preparations. Also, considering that millions of patients are being treated with EPO, clinicians need to be aware of signs and consequences of this rare but severe clinical case.

• Tuberculosis and Respiratory Diseases
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• v.76 no.1
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• pp.23-29
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• 2014

Background: Interferon-${\gamma}$ assays based on tuberculosis (TB)-specific antigens have been utilized for diagnosing and ruling out latent TB and active TB, but their utility is still limited for TB incidence countries. The aim of this study is to understand the clinical utility of enzyme-linked immunospot (ELISpot) assays among patients with clinically suspected TB and healthy adults in clinical practices and community-based settings. Methods: The ELISpot assays (T SPOT.TB, Oxford Immunotec, UK) were prospectively performed in 202 patients. After excluding those with indeterminate results, 196 were included for analysis: 41 were TB patients, 93 were non-TB patients, and 62 were healthy adults. Results: The sensitivity and negative predictive values of the T SPOT.TB assays for the diagnosis of TB were 87.8% and 89.1%, respectively, among patients with suspected TB. The agreement between the tuberculin skin test (10-mm cutoff) and the T SPOT.TB assay was 66.1% (kappa=0.335) in all participants and 80.0% (kappa=0.412) in TB patients. Among those without TB (n=155), a past history of TB and fibrotic TB scar on chest X-rays were significant factors that yielded positive T SPOT.TB results. There was a significant difference in the magnitude of T SPOT.TB spot counts between TB patients and non-TB patients or healthy adults. Conclusion: The T SPOT.TB assay appeared to be a useful test for the diagnostic exclusion of TB. A positive result, however, should be cautiously interpreted for potential positives among those without active TB in intermediate TB incidence areas.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.922-926
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• 2013

3,3',4,4'-Tetrachlorobiphenyl (IUPAC PCB77) is one of seven indicative polychlorinated biphenyls (PCBs) in the surface sediments. The current study presents a novel polyclonal antibody for the determination of the PCB77 using indirect competitive enzyme-linked immunosorbent assay. Under optimum conditions, PCB77 was determined within the concentration range of 0.01-100 ${\mu}g\;L^{-1}$, with a detection limit of 0.057 ${\mu}g\;L^{-1}$. The assays were tested for their cross-reactivity profiles using 3 selected congeners and 4 Aroclor products. The assays were highly specific for coplanar PCB congeners, but less specific for Aroclor1248. The spiked recoveries from five sediment samples were 86%-114% for PCB77 from ELISA, which were satisfactory. The current study demonstrated that the developed antiserum and immunoassay procedure can be used to detect PCB77 in environmental samples. The results of the sediment analysis were confirmed by conventional GC/ECD.

• Journal of Pharmaceutical Investigation
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• v.33 no.4
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• pp.273-279
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• 2003

Pancreatin is a enzyme mixture breaking down carbohydrates, proteins and lipids. Most pancreatin used in Korea is imported from foreign countries. However, guideline of each country for pancreatin produced from each country is different. Therefore, guideline for pancreatin imported from several countries, such as Europe, Japan and America, it is standardized to control its quality. Assay of enzyme activity for pancreatin in KP is similar to tat in JP, but it is significantly different from those in FP ad in USP. We measured pancreatin digestive activities of 17 commercial products. Activity assay of digestive enzymes, starch- and lipid-digestive enzymes, for pancreatin by KP method (including JP) was difficult compared to those by FIP ad USP methods. Particularly, activity assays of starch- and lipid-digestive enzymes by KP method were mistakable, ad varied in diluted samples than those by FIP. However, activity assay of protein-digestive enzyme by KP method was similar to that by FIP. Starch-digestive enzyme activities of 17 commercial pancreatins by KP method were lower 0.079-fold compared to those by FIP method. Their protein-digestive enzyme activities by KP method were higher 75.7-fold than those by FIP method. Their lipid-digestive enzyme activities by KP method were lower 0.234-fold compared to those by FIP method.

• Archives of Pharmacal Research
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• v.17 no.5
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• pp.309-313
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• 1994

Phytase of rat intestine had a large amount of oilgosacchanrides ; The enzyme consisted of two different subunits with the molecular weights of 90 KDa and 70 KDa in its intack form, whereas the apparent molecular weights tumed to 72 KDa and 52 KDa, respectively, after deglycosylation. The treatment with glycopeptidase F reduced the molecular weights from 90 KDa and 70 KDa to 83 KDa and 52 KDa, respectively, While endoglycosidase H caused no change in their molecular weights. These results indicate that the 70KDa subunit contains only the N-linked oilgosaccharide chains, while the 90KDa subunit ocntains O-linked oilgosaccharides as well as N-linked ones. Enzyme-linked lectin assays suggeted that bisecting N-acetyl-D-glucosamine and galactose 1-4 N-acetyl-D-glucosamine structures were present and that fucose was included in these oilgosaccharide moieties. Sialic acid was not found in either subunit.

• Bulletin of the Korean Chemical Society
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• v.18 no.11
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• pp.1149-1152
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• 1997

An enzyme electrode for the amperometric measurement of urea was prepared by co-immobilizing L-glutamate dehydrogenase and urease onto an Immobilon-AV affinity membrane attached to a glassy carbon electrode. The reduced nicotinamide adenine dinucleotide(NADH) was used as the electroactive species. The electrochemical oxidation of NADH was monitored at +1.0 volt vs. Ag/AgCl. The enzyme-immobilized electrode was linear over the range of 2.0 × 10-5 to 2 × 10-4 M. The response time of the electrode was approximately 3 min. and the optimum pH of the enzyme immobilized membrane was pH 7.4-7.6 (Dulbcco's buffer solution). It was stable for at least two weeks or 50 assays. There was no interference from other physiological species, except from high levels of ascorbic acid.

• Journal of Microbiology and Biotechnology
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• v.27 no.6
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• pp.1157-1162
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• 2017

The goal of this study was to identify and characterize selected Trichoderma isolates by metabolic profiling and enzyme assay for evaluation of their potential as biocontrol agents against plant pathogens. Trichoderma isolates were obtained from the Rural Development Administration Genebank Information Center (Wanju, Republic of Korea). Eleven Trichoderma isolates were re-identified using ribosomal DNA internal transcribed spacer (ITS) regions. ITS sequence results showed new identification of Trichoderma isolates. In addition, metabolic profiling of the ethyl acetate extracts of the liquid cultures of five Trichoderma isolates that showed the best anti-Phytophthora activities was conducted using gas chromatography-mass spectrometry. Metabolic profiling revealed that Trichoderma isolates shared common metabolites with well-known antifungal activities. Enzyme assays indicated strong cell wall-degrading enzyme activities of Trichoderma isolates. Overall, our results indicated that the selected Trichoderma isolates have great potential for use as biocontrol agents against plant pathogens.

• BMB Reports
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• v.30 no.6
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• pp.390-396
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• 1997

A sandwich-type enzyme-linked immunosorbent assay (ELISA) for the quantification of human apolipoprotein A-I (apoA-I) was developed using monoclonal antibodies. For this assay, we used three monoclonal antibodies to trap and detect apo A-I. HDAI16 and HDA15 monoclonal antibodies were used for trapping apoA-I and HDAI8 monoclonal antibody was for detecting apoA-I. These three monoclonal antibodies were produced by immunizing mice with high density lipoprotein (HDL) isolated from human plasma. By immunoblot analysis, these three monoclonal antibodies were specific to apoA-I and showed no cross-reactivities with other plasma proteins. The results of competition assays for epitope cross-reactivity test also verified that these monoclonal antibodies identified separate and distinct epitopes on HDL and apoA-I. Affinity constants of monoclonal antibodies were measured by ELISA. Their association constants ranged from $10^7$ to $10^8$ $M^{-1}$. For this assay, pure apoA-I was isolated by affinity chromatography using monoclonal antibodies. In this sandwich assay, the amount of HRP-labeled HDAI8 bound to apoA-I trapped by HDAI16 and HDAI5 was proportional to apoA-I concentration in the range of 0 to 500ng/ml. ApoA-I concentration in plasma was calculated from the linear regression equation of standard curve. The precision and reliability of the assays are reflected in the low intra-and interassay coefficients of variation that averaged 3.25% and 4.30%, respectively. This assay is sensitive, simple, reproducible, convenient in incubation interval, and does not use radioisotope: thus it can be widely applied in clinical laboratories.

• Journal of radiological science and technology
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• v.24 no.1
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• pp.75-82
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• 2001

Effect of single pre-administration of Cordyceps militaris(Cm) extract on the survival ratio, body weight and organ weight changes and blood cell counts after whole-body ${\gamma}-irradiation$ were investigated. The single pre-administration of Cm extract at 24 hrs before ${\gamma}-irradiation$ increased the 40-day survival ratio of irradiated mice from 60.1% to 71.4%. The administration of Cm extract completely prevented weight reductions of spleen and thymus produced by ${\gamma}-irradiation$ (P<0.01, P<0.05). Similar but somewhat less radioprotective effect was also found In the testis of the Cm treated mice. The administration of Cm extract retarded the reduction of both leukocyte and lymphocyte counts occured during the first 7 days and accelerated the recovery of the counts thereafter. The exrtract also acclerated the recovery of the erythrocyte counts occured after the day 21th. SDS-polyacrylamide gel electrophoresis of the soluble proteins extracted from various organs did not reveal differences to any extent in all groups except in the livers of the irradiated and extract treated groups, in which some proteins were missing or less present. Also, the result of general intra and extra mycelial enzyme assays with Cm, extramycelial enzyme activity was relatively higher than the intramycelial enzyme, Cm appeared to indicate that ${\alpha}-amylase$ was the highest among the enzymes and gluosidase and chitinase were followed. Since the spleen, thymus and testis have been well known as radiosensitive organs, the protective action of Cm extract on irradiated mice may be responsible for its enhancing recovery of these organs. Although the exact mechanism in protective effect of Cm extract on irradiated mice is not clear yet, the present study is the first report regarding the Cm which was tested and found to be a potential radioprotective agent.

• Journal of Applied Biological Chemistry
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• v.60 no.3
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• pp.241-244
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• 2017

The antioxidant activity of various solvent extracts from Jeju camellia mistletoe (Korthalsella japonica (Thunb.) Engl.) was investigated using various in vitro assays as the 1,1-diphenyl-2-picrylhydrazyl radical scavenging, ferrous ion chelating and reducing power assays. Methanol and ethanol extracts showed the most potent antioxidant activity in all assays tested followed by water extract. The inhibitory effect of the Jeju camellia mistletoe extracts on pancreatic lipase and $\acute{a}$-glucosidase was also evaluated and the results showed that methanol and ethanol extracts markedly reduced both enzyme activities. Therefore, the methanol and ethanol extracts of Jeju camellia mistletoe is definitely worthy of further investigation for these beneficial effects on nutraceutical medicine.