• Journal of Adhesion and Interface
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• v.8 no.1
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• pp.8-14
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• 2007

Poly(urethane-methyl methacrylate) hybrid emulsions can be controlled with their thermal, mechanical and anti-chemical properties as plastic coating materials. In this study, water dispersed poly(urethane-methyl methacrylate) hybrid emulsions were prepared by prepolymer synthesis and soap free emulsion polymerization. For imparting hydrophilicity on polyurethane prepolymer, 2,2-bis (hydroxymethyl) propionic acid was added to the polyurethane prepolymer with methyl methacrylate monomer and was neutralizated by triethylamine (TEA). After neutralization, the prepolymer mixture was dispersed in the water phase with stable droplets. The synthesis was carried out with chain extension from the ethylene diamine and initiation of methyl methacrylate by soap free emulsion polymerization. Stable poly(urethane-methyl methacrylate) hybrid emulsion was successfully obtained with different synthetic conditions and acrylic monomer contents. Poly(urethane-methyl methacrylate) hybrid emulsion were characterized and compared with tensile strength, viscosity, and adhesion properties.

• Journal of Veterinary Clinics
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• v.20 no.2
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• pp.150-154
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• 2003

A disease with severe diarrhea occurred in a herd of one thousand, 1-week-old piglets in Chinju, Korea, and was diagnosed as porcine epidemic diarrhea by the detection of N gene of porcine epidemic diarrhea virus (PEDV) from small intestines. A PEDV, named as Chinju99, was also isolated from the intestines after two blind-passages in Vero cells supplemented with trypsin (10 ug/ml). and the biological and physicochemical properties of the isolate were characterized. The virion was roughly spherical in shape and had spike peplomers on its outer surface. The virus exhibited cytopathic effects such as rounding degeneration at initiation of infection and syncytia formation later in Vero cells. The virus was labile to 20% ether and 5% chloroform but stable in acid with pH 4-7 at $4^{\circ}C$. The infectivity of the virus was maintained at $50^{\circ}C$ for 180 min, and the buoyant density of the virus in sucrose was 1.180 g/ml. All biological and physicochemical properties of the virus were typical features of coronaviruses.

• Biomedical Science Letters
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• v.2 no.2
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• pp.231-240
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• 1996

Human blood clotting (coagulation) factor 9 cDNA which codes for 461 amino acid has been cloned by screening human fetal liver cDNA library using PCR. This 1.4 kb cDNA spanning from the ATG initiation codon to the TAA termination codon was cloned into bacterial .expression vector pGEX-2T, generating pGEX-F9 plasmid. The plasmid pGEX-F9 expresses about 73 kDa GST (Glutathione S-transferase)-Factor 9 fusion protein when introduced into E. coli. Western blot analysis using polyclonal antibody raised against human factor 9 confirmed this fusion protein contains factor 9 protein. The level of GST-factor 9 expression was about 20% of total protein and the purification of fusion protein was efficiently achieved by using GST agarose bead based on one step purification protocol.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.4
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• pp.888-894
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• 2009

It has been reported that silibinin, a natural polyphenolic flavonoid, induces cell death in various cancer cell types. However, the underlying mechanisms by which silibinin induces apoptosis in human glioma cells are poorly understood. The present study was therefore undertaken to examine the effect of silibinin on glioma cell apoptosis and to determine its underlying mechanism in human glioma cells. Apoptosis was estimated by FACS analysis. Reactive oxygen species (ROS) generation and mitochondrial membrane potential (${\Psi}m$) were measured using fluorescence dyes DCFH-DA and $DiOC_6$(3), respectively. Cytochrome c release from mitochondria and caspase-3 activation were estimated by Western blot analysis using specific antibodies. Exposure of cells to 30 mM silibinin induced apoptosis starting at 6 h, with increasing effects after 12-48h in a time-dependent manner. Silibinin caused ROS generation and disruption of ym, which were associated with the silibinin-induced apoptosis. The silibinin-induced ROS generation and disruption in ym were prevented by inhibitors of mitochondrial electron transport chain. The hydrogen peroxide scavenger catalase blocked ROS generation and apoptosis induced by silibinin. Silibinin induced cytochrome c release into cytosolic fraction and its effect was prevented by catalase and cyclosporine A. Silibinin treatment caused caspase-3 activation, which was inhibited by DVED-CHO and cyclosporine A. Pretreatment of caspase inhibitors also protected against the silibinin-induced apoptosis. These findings indicate that ROS generation plays a critical role in the initiation of the silibinin-induced apoptotic cascade by mediation of the mitochondrial apoptotic pathway including the disruption of ${\Psi}m$, cytochrome c release, and caspase-3 activation.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7589-7594
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• 2015

Background: MicroRNAs (miRNAs) are small non-coding RNA molecules, implicated in several activities like initiation, progression and prognosis of various cancers. Single nucleotide polymorphisms (SNPs) in miRNA genes can lead to alteration in mRNA expression, resulting in diverse functional consequences. The aim of our study was to investigate the association of miR-149C>T and miR-196a2C>T SNPs with susceptibility to development of oral squamous cell carcinoma (OSCC) in South Indian subjects. Materials and Methods: 100 OSCC patients and 102 healthy controls from the general population were recruited for the study. Genetic analysis was performed by polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP) as per a standard protocol. Results: The genotype frequencies in miR-196a2 polymorphism, of TT, CT and CC in the OSCC patients were 69%,10% and 22% respectively while for control group it was 80%, 15% and 5% respectively. The CC genotype of miR196a2 polymorphism was significantly associated with oral squamous cell carcinoma. The genotype frequencies in miR-149 polymorphisms of CC, CT and TT in the oral squamous cell carcinoma (OSCC) patients were 72%, 22% and 6% respectively and for control group 88%, 12% and 0% respectively. CT and TT genotypes of miR149 polymorphism were found to be significantly associated with OSCC (p = 0.05 and 0.07). Conclusions: Our study suggests that miR-196a2C>T and miR-149C>T polymorphisms may play crucial roles in the development of OSCC in South Indian subjects.

• Journal of Ginseng Research
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• v.35 no.4
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• pp.413-420
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• 2011

We investigated whether Korean red ginseng (KRG) and highly active antiretroviral therapy (HAART) affect the frequency of gross deletion in 5'LTR/gag in 20 hemophiliacs. This study is a prospective study in 20 hemophiliacs who were infected with Korean subclade B of HIV-1 from two cash-paid plasma donors in 1990. Over a 13-year period, we obtained 436 amplicons of 5'LTR/gag genes by nested polymerase chain reaction using 147 peripheral blood mononuclear cells. Of the 436 amplicons, 92 (21.1%) showed gross deletion in 5'LTR/gag. Despite of a 2.3-fold higher monthly dose of KRG intake, the frequency of gross deletion in 5'LTR/gag (16.4%) was significantly decreased during HAART compared with 28.1% prior to HAART (p<0.01). Gross deletion in 5'LTR/gag was 10% more detected on KRG-therapy than prior to KRG-therapy (p<0.05). In addition, we also obtained 28 amplicons containing premature stop codon or isoleucine at initiation codon of 254 amplicons sequenced on KRG intake (7.5%) or HAART (13.6%) compared with 0% before KRG intake. These findings indicate that high frequency of gross deletion in 5'LTR/gag and genetic defects prior to HAART are significantly associated with KRG intake and the detection of gross deletion in 5'LTR/gag is decreased by HAART.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.13
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• pp.5233-5237
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• 2014

Epigenetic modifications of tumour suppressor genes are involved in all kinds of human cancer. Aberrant promoter methylation is also considered to play an essential role in development of lung cancer, but the pathogenesis remains unclear.We collected the data of 112 subjects, including 56 diagnosed patients with lung cancer and 56 controls without cancer. Methylation of the FHIT, RASSF1A and RAR-${\beta}$ genes in DNA from all samples and the corresponding gene methylation status were assessed using the methylation-specific polymerase chain reaction (PCR, MSP). The results showed that the total frequency of separate gene methylation was significantly higher in lung cancer compared with controls (33.9-85.7 vs 0 %) (p<0.01).Similar outcomes were obtained from the aberrant methylation of combinations of any two or three genes (p<0.01). There was a tendency that the frequency of combinations of any two or three genes was higher in stage I+II than that in stage III+IV with lung cancer. However, no significant difference was found across various clinical stages and clinic pathological gradings of lung cancer (p>0.05).These observations suggest that there is a significant association of promoter methylation of individual genes with lung cancer risk, and that aberrant methylation of combination of any two or three genes may be associated with clinical stage in lung cancer patients and involved in the initiation of lung cancer tumorigenesis. Methylation of FHIT, RASSF1A and $RAR{\beta}$ genes may be related to progression of lung oncogenesis.

• ALGAE
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• v.31 no.2
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• pp.167-174
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• 2016

Biological response of cells to variable conditions should affect the expression level of certain genes. Quantification of these changes in target genes needs stable internal controls. Real-time quantitative polymerase chain reaction (PCR) has traditionally used reference or ‘housekeeping’ genes, that are considered to maintain equal expression in different conditions, to evaluate changes in target genes between samples and experimental conditions. Recent studies showed that some housekeeping genes may vary considerably in certain biological samples. This has not been evaluated in red algae. In order to identify the optimal internal controls for real-time PCR, we studied the expression of eleven commonly used housekeeping genes; elongation factor 1-alpha, glyceraldehyde-3-phosphate dehydrogenase, β-actin, polyubiquitin, 30S ribosomal gene, 60S ribosomal gene, beta-tubulin, alpha-tubulin, translation initiation factor, ubiquitin-conjugating enzyme, and isocitrate dehydrogenase in different life-history stages of Bostrychia moritziana. Our results suggest that glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and 30S ribosomal gene, have the most stable gene expression levels between the different life history stages (male, female, carposporophyte, and tetrasporophyte), while the other genes are not satisfactory as internal controls. These results suggest that the combinations of GAPDH and 30S would be useful as internal controls to assess expression level changes in genes that may control different physiological processes in this organism or that may change in different life history stages. These results may also be useful in other red algal systems.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.4
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• pp.384-391
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• 2007

Hydrogen-blending effects in flame structure and NO emission behavior are numerically studied with detailed chemistry in methane-air counterflow diffusion flames. The composition of fuel is systematically changed from pure methane to the blending fuel of methane-hydrogen through $H_2$ molar addition up to 30%. Flame structure, which can be described representatively as a fuel consumption layer and a $H_2$-CO consumption layer, is shown to be changed considerably in hydrogen-blending methane flames, compared to pure methane flames. The differences are displayed through maximum flame temperature, the overlap of fuel and oxygen, and the behaviors of the production rates of major species. Hydrogen-blending into hydrocarbon fuel can be a promising technology to reduce both the CO and $CO_2$ emissions supposing that NOx emission should be reduced through some technologies in industrial burners. These drastic changes of flame structure affect NO emission behavior considerably. The changes of thermal NO and prompt NO are also provided according to hydrogen-blending. Importantly contributing reaction steps to prompt NO are addressed in pure methane and hydrogen-blending methane flames.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.2
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• pp.137-145
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• 2000

Carcinogenesis is a multi-stage process that generally consists of at least three steps; initiation, promotion, and progression. If one of these carcinogenic steps were suppressed or delayed, the cancer could be prevented. Cancer chemoprevention is defined to be inhibition or reversal of the carcinogenic process by the specific chemical agents and is a novel approach to cancer management alternative to conventional chemotherapy. Chlorophylln(CHL), a water-soluble derivative of chlorophyll, containing sodium and copper, has been known to be strong antimutagen in several test systems, but its mechanism of antimutagenic action is unknown. In the present experiment, the possibility of CHL as chemopreventive drugs on 7,12-dimethylbenz[a]anthracene(DMBA)-induced hamster buccal pouch carcinogenesis was investigated by mutagenicity test, carcinogenicity test, and frequency or spectrum of H-ras mutations in the both of DMBA-induced and chlorophylln-pretreated-DMBA induced tumor by polymerase chain reaction and non-isotopic restriction fragment length polymorphism. The treatment of CHL reduced the yields and multiplicity of the 0.5% DMBA-induced tumor, 86% to 62.5% and $3.7{\pm}0.6$ to $1.4{\pm}0.3$, respectively. The occurrence of histidine revertant by $20{\mu}mole$ DMBA was inhibited 25.6 to 81.7% by 1 to $5{\mu}M$ CHL in a dose-dependent manner. The mutation rates of H-ras gene in DMBA-induced and CHL-pretreated-DMBA induced tumor were 96%, 94% of which the most mutations were in codon 12/13. These results suggest that CHL inhibits the carcinogenic action of DMBA by the formation of complex between CHL and DMBA or the inhibition of the activation of DMBA in vivo. But CHL did not affect the mutation rates or its spectrum in already formed tumor.