• Korean Journal of Veterinary Service
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• v.22 no.4
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• pp.363-370
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• 1999

Isolation of PRRSV was attempted from 646 swine sera collected from swine farms. The MARC-145 cell, which is highly permissive to PRRSV, was used for virus isolation, propagation, IFA test, and VN test. Total 36 cytopathic viruses to MARC-145 cells were isolated. The virus isolates were identified as a PRRSV by the IFA test and VN test using the reference sera prepared by experimental infection of reference PRRSV CNV-1 into 30 day-old pig. In addition to serological conformation, ORF5 of genomic RNA of 6 selected cytopathic viruses were amplified by the RT-PCR. The resulting PCR products were examined by electrophoresis in 1.2% agarose gel. An appropriate bands of about 680bp including the flanking sequence of total 80bp were seen on agarose gel.

• Toxicological Research
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• v.13 no.1_2
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• pp.39-48
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• 1997

Cyclophosphamide(25, 50 or 100 mg/kg), orally administered to male Sprague-Dawley rats, caused a time- and dose-dependent thymic atrophy. In the light microscopic examination of the atrophic thymus, thymocytes with condensed or fragmented nucleus were multifocally observed in the cortical region, started to increase 8 hr after CPA treatment and reached to the maximal level at 16 hr, although such cells were not seen after 48 hr when the severe depletion of thymocytes were marked. In agarose gel electrophoresis to analyze the DNA changes, DNA extracted from atrophic thymus showed a oligonucleosomal laddering at the corresponding time to morphological changes. In an additional supportive experiment, thymocytes showing morphological changes, nuclear condensation or apoptotic body, exhibited a positive reaction to immunoperoxidase staining using in situ apoptosis detection kit. Separately, agarose gel electrophoresis of DNA from bone .marrow cells was performed to investigate the involvement of bone marrow cells in the process of thymocyte apoptosis. Although DNA laddering was slightly increased 2 and 4 hr after treatment, no clear correlation was inferred. Taken togather, it is concluded that thymocytes showing morphological changes in thymic atrophy induced by cyclophosphamide administration represent an apoptosis having biochemical nature of programmed cell death.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.189-195
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• 2002

The aim of this study was to investigate the action of benzalkonium chloride (BAC) used as a preservative in most ophthalmic topical solutions, on human corneal epithelial (HCE) cells in vitro. HCE cell line was exposed to BAC solutions at various concentrations (0.01%~0.0001%) for 15 minutes followed by 24 hours of cell recovery. Cell viability was assessed using MTT assay and chromatin condensation with a Hoechst 33342 test. The expression of membrane protein Fas and Fas ligand was examined by western blot and immunocytochemistry, and DNA fragmentation was studied by agarose gel electrophoresis. A significant decrease of membrane integrity with chromatin condensation was observed with BAC tested at concentrations of 0.005% and higher. BAC was cytotoxic preservatives in this study. An apoptotic mechanism appeared to be present at low concentrations of BAC, whereas a necrotic process appeared at higher concentrations. A functional Fas-mediated apoptotic pathway is present in cultured HCE cells and can be activated by upregulation of Fas expression with BAC.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7053-7060
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• 2015

In the present work, novel orange peel was extracted with 100%EtOH (ethanol) and fractionated into four fractions namely F1, F2, F3, F4 which were eluted from paper chromatographs using 100%EtOH, 80%EtOH, 50%EtOH and pure water respectively. The crude extract and its four fractions were evaluated for their total polyphenol content (TPC), total flavonoid content (TFC) and radical scavenging activity using DPPH (1,1-diphenyl-2-picrylhydrazyl) assay. Their cytotoxic activity using WST assay and DNA damage by agarose gel electrophoresis were also evaluated in a human leukemia HL-60 cell line. The findings revealed that F4 had the highest TPC followed by crude extract, F2, F3 and F1. However, the crude extract had the highest TFC followed by F4, F3, F2, and F1. Depending on the values of $EC_{50}$ and trolox equivalent antioxidant capacity, F4 possessed the strongest antioxidant activity while F1 and F2 displayed weak antioxidant activity. Further, incubation HL-60 cells with extract/fractions for 24h caused an inhibition of cell viability in a concentration-dependent manner. F3 and F4 exhibited a high antiproliferative activity with a narrow range of $IC_{50}$ values ($45.9-48.9{\mu}g/ml$). Crude extract exhibited the weakest antiproliferative activity with an $IC_{50}$ value of $314.89{\mu}g/ml$. Analysis of DNA fragmentation displayed DNA degradation in the form of a smear-type pattern upon agarose gel after incubation of HL-60 cells with F3 and F4 for 6 h. Overall, F3 and F4 appear to be good sources of phytochemicals with antioxidant and potential anticancer activities.

• Korean Journal of Microbiology
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• v.34 no.1_2
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• pp.43-50
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• 1998

Induction and purification of the GroEL homolog from Streptococcus pneumolliae were characterized. The stress conditions were determined by temperature, ethanol, NaCI, $H_2O_2$ methyl methanesulfonate, and ethyl methanesulfonate. And stress induced proteins were analyzed using [$^{35}S$]-methionine labeling method. Heat shock induced the synthesis of a set of about 3 heat shock proteins (hsps) (65, 73, and 84-kDa). Of those 3 hsps, a 65 kDa protein, hsp65, was purified by DEAE-Sephacel and ATP-agarose column chromatography, and used for antibody preparation. Immunoblot analysis employing antisera raised against pneumococcus hsp65 demonstrated cross-reactivity with a 60 kDa protein in Eschericha coli. Also cross reaction of the purified p65 with anti-Escherichia coli GroEL monoclonal antibody demonstrated that pneumococcal hsp65 is the GroEL homolog.

• Microbiology and Biotechnology Letters
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• v.37 no.2
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• pp.105-109
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• 2009

Among signal transduction systems by protein phosphorylation Akt/PKB protein kinase which is one of serine/threonine kinases, is known to regulate the survival and death of the cell and glucose metabolism. Thus, Akt/PKB protein kinase has been used as one of the target proteins to find anti-cancer agents from natural products. In this study, human Akt/PKB protein kinase was expressed in Escherichia coli expression system for the mass production. Human Akt/PKB protein kinase expressed in E. coli formed inclusion body under the general condition. However, most of the expressed protein was solubilized under the culture temperature at $27^{\circ}C$ and 0.01-0.09 mM of IPTG for induction of the protein expression. The expressed protein was purified using $Ni^{2+}$-NTA agarose column and confirmed by using anti-Akt antibody. Subsequently, the purified human Akt/PKB protein kinase was activated by in vitro phosphorylation using cellular extract containing kinases. The activated protein was confirmed to phosphorylate the specific fluorescent peptide specially designed as the artificial substrate for Akt/PKB protein kinase.

• Journal of Life Science
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• v.18 no.8
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• pp.1036-1041
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• 2008

Methenyltetrahydrofolate synthetase extract was obtained from mouse liver and purified via $30{\sim}70%$ ammonium sulfate fractionation, Fast Q anion exchange and phenyl agarose chromatography. HPLC gel chromatography and SDS-polyacrylamide electrophoresis experiments showed that the enzyme is a monomer with molecular weight of 23 kDa. Optimum temperature and pH were $35^{\circ}C$ and 6.5, respectively. The enzyme was chemically modified only by tetranitromethane and 1-ethyl-3- (3-dimethyl aminopropyl)-carbodiimide (EDC), indicating that tyrosine and carboxylate are in the active site. pH studies showed that 2 tyrosines are involved in the binding of the substrates and a carboxylate in catalysis. Therefore, the chemical mechanism of the enzyme is likely that 2 tyrosines bind to ATP and 5-formylTHFand a carboxylate acts as a general base.

• BMB Reports
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• v.31 no.3
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• pp.274-280
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• 1998

An inositol monophosphatase (IMPase) was purified to homogeneity from rat duodenal mucosa for the first time and its enzymatic properties were investigated. Rat duodenal mucosa peculiarly exhibited the highest IMPase activity among various rat tissues examined. By means of ammonium sulfate precipitation, followed by Q-Sepharose, polylysine agarose, reactive-red agarose column chromatography, Uno-Q FPLC, and Bio-Silect FPLC, duodenal IMPase was purified 223-fold to a specific activity of 13.6 U/mg protein. The molecular mass of the native enzyme was estimated to be 48,000 Da on gel filtration. The subunit molecular mass was determined by SDS-PAGE to be 24,000 Da. These results indicate that duodenal IMPase is a dime ric protein made up of identical subunits. Rat duodenal IMPase has distinct properties from brain IMPase. It has a broad spectrum of substrate specificity and is insensitive to $Li^+$. Duodenal IMPase does not absolutely require $Mg^{2+}$ for its catalytic activity. Furthermore, duodenal IMPase is less stable to heat than brain enzyme. It is suggested that the rat duodenal mucosa needs a large amount of IMPase whose properties are quite different from that of the brain enzyme.

• Journal of Sericultural and Entomological Science
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• v.13 no.2
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• pp.141-143
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• 1971

By means of thin-layer electrophoresis in agarose gel, hemolymph protein of healthy silkworm larvae and of the nuclear polygedrosis virus infected larvae were studied. 1. In the 4th instar, 4 fractions moving toward anode were separated. Dye-binding Capacity of the fraction was increased according to the stage. 2. After 5th day in the 5th instar, 7 fractions moving toward anode were separated, and one fraction toward cathode was separated. 3. On the first day in the 5th instar, 5 fractions were separated, and on the 4th day of the same instar 5 fractions were separated. 4. As for the hemolymph protein fractions of the polyhedrosis virus infected larvae, on the 6th and 7th day, three fractions(D.E.F) were inclined to increase, whereas on the 8th day 4 fractions(A.B.D.E) were disappeared but F fraction was inclined to decrease.

• Journal of Dairy Science and Biotechnology
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• v.29 no.1
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• pp.49-54
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• 2011

Bile salt hydrolase (BSH, EC 3.5.1.24) activity, which cleaves amide bond between carboxyl group (bile acid) and amino group (glycine or taurine), is commonly detected in gut-associated species of human and animal. During the screening of BSH active strains from the fecal samples of elderly human volunteers, strain CU30-2 was isolated on the basis of the highly active BSH producing activity. A bsh gene of the isolate was cloned into the pET22b expression vector and overexpressed in Escherichia coli BL21 (DE3) Gold by induction with 1mM IPTG. The overexpressed BSH enzyme with 6x His-tag was purified with apparent homogeneity using a $Ni^+$-NTA agarose column and characterized. The BSH enzyme of E. faecalis CU30-2 exhibited approximately 50 times higher activity against glycol-conjugated bile salts than tauro-conjugated bile salts having the highest activity against glycocholic acid. Considering the prevalence of E. faecalis strains in the human GI tract and glycol-conjugates dominated bile acid composition of human bile, further study is needed to investigate the impact of the BSH activity exerted by E. faecalis strains to the host as well as to the BSH producing strains.