• KSBB Journal
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• v.4 no.1
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• pp.40-47
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• 1989

Changes of principal components of crude green tea were determined after 30 min. of heat treatment at 10$0^{\circ}C$, l15$^{\circ}C$, 14$0^{\circ}C$, 16$0^{\circ}C$. Four kinds of free sugars(sucrose, fructose, glucose, raffinose) and an unidentified sugar compound were separated in green tea by using High Performance LiQuid Chromatography (H.P.L.C.). 26-34 peaks were isolated as aroma compounds of green tea by means of Gas Liquid Chromatography(G.L.C). The typical aroma component of green tea such as linalool, furfural, benzyl alcohol and 13 other substances were identified. Contents of most compounds were decreased by heat treatment. Especially contents of free amino acids, free sugars, vitamin C and tannins were decreased remarkably, while those of total nitrogen and soluble nitrogen were hardly changed. The effect of heat treatment on organoleptic quality of tea extracts were examined by sensory evaluation of which result indicated the most favorable tea was produced at 115$^{\circ}C$. The Percentages of loss in contents of total sugars, reducing sugars, vitamin C, free amino acids and tannins at 115$^{\circ}C$ were 17%, 16%, 36%, 12% and 15% respectively, while those were 38%, 53%, 55%, 74% and 23% at 16$0^{\circ}C$.

• Parasites, Hosts and Diseases
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• v.30 no.2
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• pp.83-90
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• 1992

Sensitivity of anti-Texoplasma antibody (IgG) test by enzyme·linked immunosorbent assay (ELISA) was evaluated in comparison with indirect laten agglutination (ILA) using 2,016 paired human samples of serum and cerebrospinal quid (CSF) . The samples were collected from neurologic patients in Korea with mass lesions in central nervous system(CNS) as revealed by imaging diagnosis(CTIMRI). When the sera were screened for anti-Toxoplasma antibody by ILA, 76 cases (3.8%) were positive (1:32 or higher titers). In the pairs samples of CSF, no positive reactions were observed. When ELISA was performed using PBS extract of Percoll purified tachysoites as antigen, cut-off absorbance was determined as 0.40 for serum and 0.27 for CSF tests. The antibody positive rates by ELISA were 7.0% in serum and 5.6% in CSF Of them, 40 cases(2.0%) showed positive reactions in both serum and CSF, The antibody positive rates were higher in groups older than 40 years, The rates were higher in male(4.7% by ILA, 8.3% by ELISA) than in female(2.2% by ILA, 5.0% by ELISA). The rates in CSF showed no such sex difference. ELISA showed twice higher positive rates when serum was tested, and was sensitive enough to detect specific antibodies in CSF. Etiologic relations between positive antibody tests and CNS lesions remained unknown.

• Parasites, Hosts and Diseases
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• v.28 no.2
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• pp.101-108
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• 1990

Surgically collected cystic fluid of Taenia solium metacestodes from patients of intracranial cystic lesion were compared in their protein composition with those from naturally infected pigs in Cheju Do, Korea and Ecuador. In non-denaturing discontinuous-polyacryla aide gel electrophoresis (disc-PAGE) , no discernible differences were recognized in banding patterns between the cystic fluids from Cheju Do and Ecuador, and between the cystic quids from pigs and human lesions except wider bands that corresponded to human albumin and T-globulin (in 4 of 9 patients). In reducing SDS-PAGE, bands in the cystic Ruid from Ecuador showed the same banding pattern with that from Cheju Do but two bands of 21 and 17 kDa were stained darker. Cystic quids (rom patients revealed the same protein compositions of the major protein bands of 94, 64, 15, 10 and 7 kDa as in the cystic fluid of pig origin, but human albumin (66 kDa), heavy and light chains of gamma globulin (55 and 22.5 kDa) were contaminated in 4 of 9 cystic fluids. Human CSF proteins seem to have been contaminated during cystic ftuid collection. In any cystic quid from patients, the majcr Protein component was 150 kDa which was subdivided into 15, 10 and 7 kDa in reducing SDS-PAGE.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2629-2633
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• 2012

Background: Raw betel nut (RBN) chewing is an important contributing factor for esophageal squamous cell carcinoma (ESCC), although associated genomic changes remain unclear. One difficulty in assessing the effects of exclusively RBN induced genetic alterations has been that earlier studies were performed with samples of patients commonly using tobacco and alcohol, in addition to betel-quid. Both CDKN2A (at 9p21) and Rb1 gene (at 13q14.2) are regarded as tumor suppressors involved in the development of ESCC. Therefore, the present study aimed to verify the RBN's ability to induce ESCC and assess the involvement of CDKN2A and Rb1 genes. Methods: A panel of dinucelotide polymorphic markers were chosen for loss of heterozygosity studies in 93 samples of which 34 were collected from patients with only RBN-chewing habit. Promoter hypermethylation was also investigated. Results: Loss in microsatellite markers D9S1748 and D9S1749, located close to exon $1{\beta}$ of CDKN2A/ARF gene at 9p21, was noted in 40% ESCC samples with the habit of RBN-chewing alone. Involvement of a novel site in the 9p23 region was also observed. Promoter hypermethylation of CDKN2A gene in the samples with the habit of only RBN-chewing alone was significantly higher (p=0.01) than Rb1 gene, also from the samples having the habit of use both RBN and tobacco (p=0.047). Conclusions: The data indicate that the disruption of 9p21 where CDKN2A gene resides, is the most frequent critical genetic event in RBN-associated carcinogenesis. The involvement of 9p23 as well as 13q14.2 could be required in later stages in RBN-mediated carcinogenesis.

• Journal of the Korean Ceramic Society
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• v.35 no.7
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• pp.721-725
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• 1998

In this study solid-phase sintered silicon caribide samples composed of SiC powder having boron and car-bon black as additives were prepared by pressureless sintering at $1950^{\circ}C$. The bending strength the frac-ture toughness and the specific werar rate of the samples were examined and the micro structures of the broken and the worn surface were observed by SEM to understand the relationship between the tri-bological charcteristics and the micro structure. Additionally the relationship between the micro struc-tures and the tribological characteristics of the samples for the frictional opponents SiC and $Al_{2}O_{3}$ pins were investigated Conclusions are as follows ; 1. The specific were rate of the samples for the SiC pin was larger than that for the $Al_{2}O_{3}$ pin. HOwever the specific wear rate for the $Al_{2}O_{3}$ pin was increased about 6,45 times as that for the SiC pin under the load increasing. 2. The specific wear rate of the SiC pin was larger than that of the $Al_{2}O_{3}$ pin. owever the specific wear rate of the $Al_{2}O_{3}$ pin was increased about 4 times as that of the SiC pin under the load increasing 3. The micro stucture of the worn surface showed a flat face without cracks in the case that the frictional opponents has the low friction coefficient but in the case of without cracks in the case that the frictional opponents has the low friction coefficient but in the case of the high friction coefficient the micro structure of the worn surface showed an uneven face having spread-ed cracks. 4. The tribological characteristics of thesolid-phase sintered SiC samples was similar to that of li-quid-phase sintered ones when the pin having the high friction coefficient was used.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.2315-2317
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• 2012

Background: Use of smoke-less tobacco (SLT) is very common in South and South-East Asian countries. It is significantly associated with various types of cancers. The objectives of this study were to assess the proportion of hospital staff that use SLT, and to identify the factors associated with its use and their practices. Methods: In a cross-sectional study, 560 staff of two tertiary care hospitals were interviewed in the year 2009. Nurses, ward boys and technicians were counted as a paramedic staff while drivers, peons, security guards and housekeeping staff were labeled as non-paramedic staff. SLT use was considered as usage of any of the following: betel quid (paan) with or without tobacco, betel nuts with or without tobacco (gutkha) and snuff (naswar). Results: About half (48.6%) of the hospital staff were using at least one type of SLT. Factors found to be statistically significant with SLT were being a male (OR=2.5; 95% CI=1.8-3.7); having no/fewer years of education (OR=1.7; 95% CI=1.2-2.4) and working as non-paramedic staff (OR=2.6; 95% CI=1.8-3.8). Majority of SLT users were using it on regular basis, for > 5 years and keeping the tobacco products in the oral cavity for >30 minutes. About half of the users started due to peer pressure and had tried to quit this habit but failed. Conclusion: In this study, about half of the study participants were using SLT in different forms. We suggest educational and behavioral interventions for control of SLT usage.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3335-3340
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• 2016

Background: Oral submucous fibrosis (OSF) is a precancerous condition with a 4 to13% malignant transformation rate. Related to the habit of areca nut chewing it is mainly prevalent in South-east Asian countries where the habit of betel quid chewing is frequently practised. On chewing, alkaloids and polyphenols are released which undergo nitrosation and give rise to N-nitrosamines which are cytotoxic agents. CYP450 is a microsomal enzyme group which metabolizes various endogenous and exogenous chemicals including those released by areca nut chewing. CYP1A1 plays a central role in metabolic activation of these xenobiotics, whereas CYP2E1 metabolizes nitrosamines and tannins. Polymorphisms in genes that code for these enzymes may alter their expression or function and may therefore affect an individuals susceptibility regarding OSF and oral cancer. The present study was therefore undertaken to investigate the association of polymorphisms in CYP1A1 m2 and CYP2E1 (RsaI/PstI) sites with risk of OSF among areca nut chewers in the Northern India population. A total of 95 histopathologically confirmed cases of OSF with history of areca nut chewing not less than 1 year and 80, age and sex matched controls without any clinical signs and symptoms of OSF with areca nut chewing habit not less than 1 year were enrolled. DNA was extracted from peripheral blood samples and polymorphisms were analyzed by PCR-RFLP method. Gene polymorphism of CYP1A1 at NcoI site was observed to be significantly higher (p = 0.016) in cases of OSF when compared to controls. Association of CYP1A1 gene polymorphism at NcoI site and the risk of OSF (Odd's Ratio = 2.275) was also observed to be significant. However, no such association was observed for the CYP2E1 gene polymorphism (Odd's Ratio = 0.815). Our results suggest that the CYP1A1 gene polymorphism at the NcoI site confers an increased risk for OSF.

• The Korean Journal of Applied Statistics
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• v.30 no.4
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• pp.539-553
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• 2017

We propose a multi-state model to analyze semi-competing risks data with interval-censored or missing intermediate events. This model is an extension of the three states of the illness-death model: healthy, disease, and dead. The 'diseased' state can be considered as the intermediate event. Two more states are added into the illness-death model to incorporate the missing events, which are caused by a loss of follow-up before the end of a study. One of them is a state of the lost-to-follow-up (LTF), and the other is an unobservable state that represents an intermediate event experienced after the occurrence of LTF. Given covariates, we employ the Lin and Ying additive hazards model with log-normal frailty and construct a conditional likelihood to estimate transition intensities between states in the multi-state model. A marginalization of the full likelihood is completed using adaptive importance sampling, and the optimal solution of the regression parameters is achieved through an iterative quasi-Newton algorithm. Simulation studies are performed to investigate the finite-sample performance of the proposed estimation method in terms of empirical coverage probability of true regression parameters. Our proposed method is also illustrated with a dataset adapted from Helmer et al. (2001).

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.165-179
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• 2021

This study investigated that what strategies tobacco companies have taken for marketing tobacco and tobacco companies on news media, by reviewing the previous research analyzing the tobacco companies' documents and the news coverage of tobacco. The tobacco document studies showed that tobacco companies have created close relationships with news media, a quid pro quo, by providing advertising and diverse forms of sponsorships and obtaining favored treatment on news coverage and have built networks with journalists by supporting journalist organizations. They have also supported thinktank groups and pro-smoking groups so as to represent and advocate their perspectives and assertions on news media and have utilized sponsorship of art and culture as pseuo-event for publicizing tobacco and tobacco companies on news media. Futhermore, news coverage of tobacco showed that news media tended to deal with tobacco issues lukewarmly, without a clear position and perspective and deliver naturally tobacco industry's perspective and message that smoking is controvertial rather than totally undesirable and unacceptable. Also, the news coverages have often reflected tobacco industry's publicity strategies identified in tobacco industry documents. This study suggests how tobacco industry access and utilize news media to obtain favorable news coverage, and thus it provides a rational of why tobacco industry's publicity activities have to be regulated.

• Parasites, Hosts and Diseases
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• v.27 no.2
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• pp.131-140
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• 1989

Sera from confirmed patients of 5 hydatidosis, 67 neurocysticercosis and 89 other parasitic diseases were tested for specific antibody (IgG) levels by ELISA to cystic quid antigens from metacestodes of Echinococcus granuzosus (HF) and Taenia sodium (CF). All hydatidosis sera reacted positively to both HF and CF while neuro- cysticercosis sera did in 49.3% to HF and 85.1% to CF, The frequencies of cross- reactions were lower in other parasitic diseases to both antigens, By SDS-PAGE, protein bands of 64, 35, 22 and 7 kilodaltons (kDa) were found common in HF and CF. SDS-PAGE/immunoblot exhibited that hl·datidosis sera reacted crossly to CF at 135, 110, 100, 86, 64, 45, 39, 35 and 24 kDa bands while neurocysticercosis sera did to HF at 135, 100, 86, 64, 52, 39, 35, 29 and 24 kDa bands. These results indicated that protein bands of 135, 100, 86, 64, 39, 35 and 24 kDa were major common components in HF and CF. Protein bands of 7 kDa in HF and 15, 10 and 7 kDa in CF did not react crossly and were specific components in respective antigens.