• Bulletin of the Korean Chemical Society
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• 제33권5호
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• pp.1485-1490
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• 2012

An electrochemical immunoassay based on osmium-hippuric acid (HA) conjugate films onto the electrode is presented for the detection of urinary HA. This is the first report on the use of the oxidative electropolymerization of 5-amino-1,10-phenanthroline (5-$NH_2$-phen) for immobilizing an antigen, osmium-conjugated HA. As a redox mediator, [Os(5-amino-1,10-phenanthroline)$_2$(4-aminomethylpyridine-HA)Cl]$^{+/2+}$ (Os-phen-HA) was successfully synthesized and electropolymerized onto the screen-printed carbon electrodes (SPCEs). The interaction between osmium-HA conjugate films and antibody-HA ($anti$-HA) was performed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The electrical signals were linearly proportional to urinary HA in the range of 0.1-5.0 mg/mL, which is sufficient for use as an immunosensor using a cutoff concentration of 2.0 mg/mL in urine samples. The proposed electrochemical immunoassay method can be extended to various applications for detecting a wide range of different small antigens in the health care area.

• 대한수의학회지
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• 제36권3호
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• pp.693-698
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• 1996

Haemaphysalis longiscornis is the common cattle tick of great economic importance in Korea. Chemical control using dips or sprays has been the traditional method of attempting to kill these ticks during the infestation period. However, the presence of resistant forms to chemical, the rising costs of acaricides and environmental problems have made it almost impossible to use these chemicals on a regular basis according to the pest problem. For this reason, vaccination against ticks and breeding for host resistance against ticks are being studied. In order to determine the common proteins and antigens according to developmental stages, SDS-PAGE and western blotting were performed. In SDS-PAGE 103.3kD and 98.3kD proteins were observed as common proteins, and these proteins were observed as common antigens in western blotting. Unimmunized rabbits were infestated three times with H longicornis. The weight of the second and the third engorged ticks were 0.153g and 0.104g respectively. This weight is 69% and 47% of the first engorged ticks weight respectively. Immunized rabbits by adult ticks antigen and control were infested with H longicornis. The control taked 3-4 days to fully engorge, but the immunized rabbits taked about 7 days. So adult tick antigen may be effective to render the immunity to host.

• Bulletin of the Korean Chemical Society
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• 제30권5호
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• pp.1101-1106
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• 2009

Multivalent and multi-specific antibodies can provide valuable tools for bio-medical research, diagnosis and therapy. In antigen-antibody interactions, the avidity of antibodies depends on the affinity and the number of binding sites.$^1$ As artificial multivalent antibody agents, single chain Fv-streptavidin fusion tetramer proteins $(scFv-SA)_4$ have been previously tested.$^{1,\;2}$ Although, the Fab domain is known to be more stable than scFv in animal models,$^{3,\;4}$ it has never been used to make a multivalent agent with a streptavidin fusion. In this study, we prepared tetra-valent $(Fab-cSA)_4$ by fusing Fab with core streptavidin (cSA). This molecule was made using inclusion body production, refolding and chromatography purification. Affinities of the Fab-cSA tetramer and a scFv-cSA tetramer to a cell surface antigen were compared by ELISA using biotin-HRP. The Fab-cSA tetramer showed higher binding avidity than the scFv-cSA tetramer. The higher binding avidity of the Fab-cSA tetramer demonstrates its potential as a therapeutic agent for target-specific antibody therapy.

• Bulletin of the Korean Chemical Society
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• 제30권1호
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• pp.77-82
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• 2009

Thrombin activatable fibrinolysis inhibitor (TAFI) also known as plasma procarboxypeptidase B or U is a 60 kD glycoprotein, which is the major modulator of fibrinolysis in plasma. TAFI is a proenzyme, which is activated by proteolytic cleavage to an active carboxypeptidase B-like enzyme (TAFIa, 35.8 kD) by thrombin/thrombomodulin and plasmin. Modulation of fibrinolysis occurs when TAFIa enzymatically removes C-terminal lysine residues of partially degraded fibrin, thereby inhibiting the stimulation of tissue plasminogen activator (t-PA) modulated plasminogen activation. TAFIa undergoes a rapid conformational change at $37{^{\circ}C}$ to an inactive isoform called TAFIai. Potato tuber carboxypetidase inhibitor (PTCI) was shown to specifically bind to TAFIa as well as TAFIai. In this study, a novel immunoassay TAFIa/ai ELISA was used for quantitation of the two TAFI activation isoforms TAFIa and TAFIai. The ELISA utilizes PTCI as the capture agent and a double antibody sandwich technique for the detection. Low levels of TAFIa/ai antigen levels were detected in normal plasma and elevated levels were found in hemophilia A plasmas. TAFIa/ai antigen represents a novel marker to monitor fibrinolysis and TAFIa/ai ELISA may be a valuable assay for studying the role of TAFI in normal hemostasis and in pathological conditions.

• 생명과학회지
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• 제15권6호
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• pp.1034-1036
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• 2005

배추 종자 및 유묘에 대하여 GUS발현 또는 hepatitis B surface antigen (HBsAg)발현 벡터를 지니는 Agrobacterium tumefaciens LBA4404 세포를 이용하여 진공침윤(agroinfiltration)에 의한 형질전환을 시도하였다. 특히 ELISA를 이용한 HBsAg발현의 정량적 분석에서 agroinfiltration방법은 형질전환효율이 매우 저조하게 나타났다. 그러나 차아염소산나트륨 용액을 발아 전 또는 발아 중인 배추종자에 처리한 후 agroinfiltration을 실시한 경우 형질전환 효율이 $2\~5$배 증가하였다. 따라서 차아염소산나트륨 등의 화학연마제에 의한 종자의 상처발생이 Agrobacterium의 감염을 용이하게 함으로써 배추유묘에서의 일시유전자발현을 증대시키는 것으로 제안되고있다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권5호
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• pp.374-378
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• 2004

The effects of various environmental factors such as pH (5, 6, 7, 8 and 9), temperature (30, 37 and $40^{\circ}C$) and rotational speed (150, 200 and 250 rpm) on the growth and the hepatitis B core antigen (HBcAg) production of Escherichia coli W3110IQ were examined in the present Study. The highest growth rate is achieved at pH 7, $37^{\circ}C$ and at a rotational Speed of 250 rpm which is 0.927 $h^{-1}$. The effect of pH on cell growth is more substantial compared to other parameters; it recorded a $123\%$ different between the highest growth rate (0.927 $h^{-1}$) at pH 7 and lowest growth at pH 5. The highest protein yield is achieved at pH 9, rotational speed of 250 rpm and $40^{\circ}C$. The yield of protein at pH 7 is $154\%$ higher compared to the lowest yield achieved at pH 5. There is about $28\%$ different of the protein yield for the E. coli cultivated at 250 rpm compared to that at 150 rpm which has the lowest HBcAg yield. The yield of protein at $40^{\circ}C$ is $38\%$ higher compared to the lowest yield achieved at $30^{\circ}C$.

• BMB Reports
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• 제28권4호
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• pp.331-335
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• 1995

Simian virus 40 (SV40) small-t antigen (small-t) has been known to regulate the activity of a cellular enzyme, protein phosphatase 2A (PP2A), composed of A. B, and C subunits, via binding to the A subunit In the study presented here, the stoichiometry of the binding of small-t to PP2A was determined to be 1: 1. It was also shown that small-t binds to the AC form of PP2A with a higher apparent affinity than it binds to the free A subunit. We also characterized the interaction of PP2A with wild-type and various mutant small-ts. A single-point mutant (Val134Met) and a double-point mutant (Trp147Gly;Leu152 Pro) of small-t exhibited 3-fold and 5-fold lower potencies in inhibiting PP2A activity. respectively. This suggests that the region around amino acids between 134 and 152 of small-t might be important in regulating the enzyme activity of PP2A.

• 한국동물위생학회지
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• 제29권1호
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• pp.47-53
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• 2006

For examination of antibiotic therapeutic efficacy in canine brucellosis, this examination was carried out two female bitches infected with Brucella canis in Gyeongbuk province, and used combicillin, baytril and doxycycline in susceptible antibiotics at B canis. During 18 month after the termination of antibiotic therapy, blood sample of the two bitches were examined for B canis antibody and antigen. The antibody of one bitch was disappeared at 5 month after antibiotic therapy and the other was continued at 18 month, but two bitches were not detected antigen by blood culture and PCR. Examination of blood chemical value (AST, ALT, urea, creatinine) of two bitches was increased in AST value during antibiotic therapy.

• The Journal of Korean Physical Therapy
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• 제3권1호
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• pp.229-250
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• 1991

The study was carried out to investigate and review the principles and practices of immunocytochemical method in light microscopic level. The results were as follows. 1. Immunocytochemistry is the method to search out the intracellular position of the specific meterials using antigen -antibody reaction. 2. The chief items in immunocytochemistry are antigen, antibody and chromogen. 3. The identifical fixation is cardiac perfusion fixation. 4. The tissue slides must be prepared by vibratomy. 5. All stainings are carried out with free floating staining method. 6. There are polyclonal and monoclonal antibodies used in immunocytochemistry.

• BMB Reports
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• 제54권1호
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• pp.31-43
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• 2021

Dendritic cells (DC), which consist of several different subsets, specialize in antigen presentation and are critical for mediating the innate and adaptive immune responses. DC subsets can be classified into conventional, plasmacytoid, and monocyte-derived DC in the tumor microenvironment, and each subset plays a different role. Because of the role of intratumoral DCs in initiating antitumor immune responses with tumor-derived antigen presentation to T cells, DCs have been targeted in the treatment of cancer. By regulating the functionality of DCs, several DC-based immunotherapies have been developed, including administration of tumor-derived antigens and DC vaccines. In addition, DCs participate in the mechanisms of classical cancer therapies, such as radiation therapy and chemotherapy. Thus, regulating DCs is also important in improving current cancer therapies. Here, we will discuss the role of each DC subset in antitumor immune responses, and the current status of DC-related cancer therapies.