Biomedical subjects

Su Jeong Lee

Publications and source records attributed to Su Jeong Lee.

13 recordsLinked to original sources

PubMed2007

No association between dinucleotide repeat polymorphism in intron 1 of the epidermal growth factor receptor gene EGFR and risk of lung cancer.

The tyrosine kinase receptor EGFR pathway is one of the oncogenic signaling cascades involved in lung cancer, mediating the epidermal growth factor receptor gene EGFR. First-intron polymorphisms with greater numbers of CA dinucleotide repeats tend to downregulate EGFR expression, which suggests that this polymorphism may modulate susceptibility to lung cancer. The present hospital-based case-control study evaluated the possible association of CA repeat polymorphism in the EGFR gene with risk of lung cancer in a Korean population. A bimodal pattern appeared, with a frequency of 57.1% for 20 CA repeats and 18.6% for 16 CA repeats. There was, however, no significant difference in distribution of allele genotypes between all lung cancer cases and the controls, nor among histological types for the cases.

Adenocarcinoma↗

PubMed2006

Glu346Lys polymorphism in the methyl-CpG binding domain 4 gene and the risk of primary lung cancer.

BACKGROUND: Methyl-CpG binding domain 4 (MBD4) protein functions as a DNA repair enzyme and minimizes mutations at 5-methylcytosine. Polymorphisms in the DNA repair gene MBD4 may be associated with differences in DNA repair capacity and thereby influence an individual's susceptibility to lung cancer. To test this hypothesis, we examined the potential association between the MBD4 Glu346Lys polymorphism and the risk of lung cancer in a Korean population. METHODS: The MBD4 Glu346Lys genotypes were determined in 432 lung cancer patients and 432 healthy age- and gender-matched control subjects. RESULTS: The distribution of the MBD4 Glu346Lys genotypes was not significantly different between the overall lung cancer cases and the controls. However, when the cases were categorized by tumor histology, the Lys346Lys genotype was associated with a significantly decreased risk of adenocarcinoma (AC) as compared with the Glu346Glu genotype [adjusted odds ratio (OR) = 0.50, 95% confidence interval (CI) = 0.26-0.97, P = 0.04]. On the stratification analysis, the protective effect of the Lys346Lys genotype against AC was statistically significant in older individuals and heavier smokers (adjusted OR = 0.08, 95% CI = 0.01-0.64, P = 0.02; and adjusted OR = 0.09, 95% CI = 0.01-0.72, P = 0.02, respectively). CONCLUSIONS: Our findings suggest that the MBD4 Glu346Lys polymorphism could be used as a marker for genetic susceptibility to AC of the lung.

5-Methylcytosine↗

PubMed2006

Polymorphisms in the hMSH2 gene and the risk of primary lung cancer.

Polymorphisms in the DNA repair genes may be associated with differences in the capacity to repair DNA damage, and so this can influence an individual's susceptibility to lung cancer. To test this hypothesis, we investigated the association of hMSH2 -118T>C, IVS1+9G>C, IVS10+12A>G, and IVS12-6T>C genotypes and their haplotypes with the risk of lung cancer in a Korean population. The hMSH2 genotypes were determined in 432 lung cancer patients and in 432 healthy controls who were frequency matched for age and gender. The hMSH2 haplotypes were estimated based on a Bayesian algorithm using the Phase program. The presence of at least one IVS10+12G allele was associated with a significantly decreased risk of adenocarcinoma, as compared with the IVS10+12AA genotype [adjusted odds ratio (OR), 0.59; 95% confidence interval (95% CI), 0.40-0.88; P = 0.01], and the presence of at least one IVS12-6C allele was associated with a significantly increased risk of adenocarcinoma, as compared with the IVS12-6TT genotype (adjusted OR, 1.52; 95% CI, 1.02-2.27; P = 0.04). Consistent with the results of the genotyping analysis, the TGGT haplotype with no risk allele was associated with a significantly decreased risk of adenocarcinoma, as compared with the TCAC haplotype with two risk allele [i.e., IVS10+12A and IVS12-6C allele; adjusted OR, 0.49; 95% CI, 0.30-0.78; P = 0.003 and P(c) (Bonferroni corrected P value) = 0.012]. The effect of the hMSH2 haplotypes on the risk of adenocarcinoma was statistically significant in the never smokers and younger individuals (adjusted OR, 0.45; 95% CI, 0.27-0.75; P = 0.002 and P(c) = 0.004; and adjusted OR, 0.44; 95% CI, 0.23-0.85; P = 0.014 and P(c) = 0.028, respectively) but not in the ever-smokers and older individuals. These results suggest that the hMSH2 polymorphisms and their haplotypes may be an important genetic determinant of adenocarcinoma of the lung, particularly in never smokers.

Adenocarcinoma↗

PubMed2006

[Comparison of influential variables for smoking temptation between adolescent and adult smokers].

PURPOSE: This study attempted to identify influential variables on smoking temptation between groups: adolescent smokers and adult smokers. METHOD: A survey was conducted with 376 adolescent smokers in 4 high schools and 451 adult smokers in community settings in South Korea. Univariate statistics and regression were used for data analysis. RESULT: The most powerful predictor of smoking temptation for adolescent smokers was nicotine dependency. On the other hand, the most powerful predictor of smoking temptation for adult smokers was self-efficacy for smoking abstinence. In the high smoking temptation group, depression and nicotine dependency were the predictors for smoking temptation for adolescent smokers and nicotine dependency and pros for smoking were the predictors for smoking temptation for adult smokers. In the low smoking temptation group, cons for smoking and process of change for smoking abstinence were the predictors on smoking temptation for adolescent smokers and self-efficacy for smoking abstention and pros for smoking were the predictors on smoking temptation for adult smokers. CONCLUSION: There were different influential variables on smoking temptation according to age groups and level of smoking temptation. Smoking-cessation interventions should be tailored to the level of smoking temptation of the individual smokers.

Adolescent↗

PubMed2006

A prediction model for patient classification according to nursing need: Using data mining techniques.

The purpose of this study was to construct a prediction model for patient classification according to nursing need. The results were assessed from the classification of the hospitalized cancer patients by three different data mining techniques: logistic regression, decision tree and neural network. Among these three techniques, neural network showed the best prediction power in ROC curve verification. The prediction model for patient classification developed by neural network based on nurse needs produced a prediction accuracy of 84.06%.

Adult↗

PubMed2005

Vascular endothelial growth factor gene polymorphisms and risk of primary lung cancer.

Angiogenesis is an essential process in the development, growth, and metastasis of malignant tumors including lung cancer. DNA sequence variations in the vascular endothelial growth factor (VEGF) gene may lead to altered VEGF production and/or activity, thereby causing interindividual differences in the susceptibility to lung cancer via their actions on the pathways of tumor angiogenesis. To test this hypothesis, we investigated the potential association between three VEGF polymorphisms (-460T > C, +405C > G, and 936C > T)/haplotypes and the risk of lung cancer in a Korean population. VEGF genotypes were determined in 432 lung cancer patients and 432 healthy controls that were frequency matched for age and sex. VEGF haplotypes were predicted using Bayesian algorithm in the phase program. Compared with the combined +405 CC and CG genotype, the +405 GG genotype found associated with a significantly decreased risk of small cell carcinoma [SCC; adjusted odds ratio (OR), 0.36; 95% confidence interval (95% CI), 0.17-0.78]. The 936 CT genotype and the combined 936 CT and TT genotype were also associated with a significantly decreased risk of SCC compared with the 936 CC genotype (adjusted OR, 0.47; 95% CI, 0.26-0.85 and adjusted OR, 0.44; 95% CI, 0.24-0.80, respectively). Haplotype CGT was associated with a significantly decreased risk of SCC (adjusted OR, 0.39; 95% CI, 0.18-0.87), whereas haplotype TCC conferred a significantly increased risk of SCC (adjusted OR, 1.63; 95% CI, 1.14-2.33). None of the VEGF polymorphisms studied significantly influenced the susceptibility to lung cancer except SCC. However, haplotypes TCT and TGT were significantly associated with the risk of overall lung cancer, respectively (adjusted OR, 0.38; 95% CI, 0.25-0.60 and adjusted OR, 3.94; 95% CI, 2.00-7.76, respectively). These effects of haplotypes TCT and TGT on lung cancer risk were observed in three major histologic types of lung cancer. These results suggest that the VEGF gene may be contribute to an inherited predisposition to lung cancer.

Aged↗

PubMed2005

Methyl-CpG binding domain 1 gene polymorphisms and risk of primary lung cancer.

The methyl-CpG binding domain 1 (MBD1) protein plays an important role for transcriptional regulation of gene expression. Polymorphisms and haplotypes of the MBD1 gene may have an influence on MBD1 activity on gene expression profiles, thereby modulating an individual's susceptibility to lung cancer. To test this hypothesis, we investigated the association of MBD1 -634G>A, -501delT (-501 T/T, T/-, -/-), and Pro(401)Ala genotypes and their haplotypes with the risk of lung cancer in a Korean population. The MBD1 genotype was determined in 432 lung cancer patients and in 432 healthy control subjects who were frequency matched for age and gender. The -634GG genotype was associated with a significantly increased risk of overall lung cancer compared with the -634AA genotype [adjusted odds ratio (OR), 3.10; 95% confidence interval (95% CI), 1.24-7.75; P = 0.016]. When analyses were stratified according to the tumor histology, the -634GG genotype was associated with a significantly increased risk of adenocarcinoma compared with the -634AA genotype (adjusted OR, 4.72; 95% CI, 1.61-13.82; P = 0.005). For the MBD1 -501delT and Pro(401)Ala polymorphisms, the -501 T/T genotype was associated with a marginal significantly increased risk of adenocarcinoma compared with the -501(-/-) genotype (adjusted OR, 2.07; 95% CI, 1.02-4.20; P = 0.045), and the Pro/Pro genotype was associated with a significantly increased risk of adenocarcinoma compared with the Ala/Ala genotype (adjusted OR, 3.41; 95% CI, 1.21-9.60; P = 0.02). Consistent with the genotyping analyses, the -634G/-501T/(401)Pro haplotype was associated with a significantly increased risk of overall lung cancer and adenocarcinoma compared with the -634A/-501(-)/(401)Ala haplotype (adjusted OR, 1.44; 95% CI, 1.08-1.91; P = 0.012 and P(c) = 0.048; adjusted OR, 1.75; 95% CI, 1.20-2.56; P = 0.004 and P(c) = 0.016, respectively). On a promoter assay, the -634A allele had significantly higher promoter activity compared with the -634G allele in the Chinese hamster ovary cells and A549 cells (P < 0.05 and P < 0.001, respectively), but the -501delT polymorphism did not have an effect on the promoter activity. When comparing the promoter activity of the MBD1 haplotypes, the -634A/-501(-) haplotype had a significantly higher promoter activity than the -634G/-501T haplotype (P < 0.001). These results suggest that the MBD1 -634G>A, -501delT, and Pro(401)Ala polymorphisms and their haplotypes contribute to the genetic susceptibility for lung cancer and particularly for adenocarcinoma.

Adenocarcinoma↗

PubMed2005

cDNA cloning and expression of biologically active platelet activating factor-acetylhydrolase (PAF-AH) from bovine mammary gland.

Platelet activating factor (PAF)-acetylhydrolase (PAF-AH) is an enzyme that hydrolyzes the acetyl ester at the sn-2 position of PAF, and converts it to the inactive metabolite, lyso PAF. This enzyme is distributed widely in the intracellular as well as the extracellular matrix and is believed to be a defense mechanism that protects the host against the toxic effects of PAF and other biologically active oxidized phospholipids. Purification and expression of cDNA cloning of the intracellular and extracellular types of PAF-AH from several sources from different species have been reported. In this study, the cDNA for PAF-AH was cloned by reverse transcription (RT)-PCR from total RNA of bovine mammary gland. The complete amino acid sequences from the cDNA contains 444 amino acids and was identical to that of the PAF-AH isolated from the bovine spleen cDNA library except for two mismatches of amino acid residues (Thr-247 to Met and Ile-431 to Thr). Recombinant PAF-AH was expressed in HEK 293 cells, which exhibited enzyme activity in the in vitro assay system. Furthermore, recombinant bovine PAF-AH was identified by western blot using human plasma PAF-AH antibody as a monomeric polypeptide with a molecular weight of approximately 43 kDa. This protein can be applied to in vivo models to test its protective role against the deleterious PAF actions.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗

PubMed2005

[An evaluation study of dementia information providing websites in Korea].

PURPOSE: The present study purposed to investigate and analyze domestic websites providing information about dementia and to suggest future directions for the development of dementia-related websites. METHOD: For this purpose, the researcher selected 13 domestic websites that were available in November and December 2004, and evaluated them in terms of construction, operation, accessibility and contents on a scale 4 point (0~3). RESULT: The construction of dementia-related websites got 6-13 out of 18 points, which suggests that management policies for the operation of dementia-related websites are inadequate. The operation of dementia-related websites got 7-15 out of 24 points. In particular, all 13 sites got a low score in the aspect of continuance. With regard to accessibility, the sites were evaluated on how easily users could access the sites and they got 2-8 out of 15 points. In evaluating contents, the sites got 9-18 out of 21 points with regard to the purpose and appropriateness of the contents. CONCLUSION: This shows that most sites did not provide diverse types of dementia-related information. Because it is highly advantageous to perform primary dementia-preventing management through websites, this study proposes to develop a website evaluation system in order to provide high quality dementia-related information.

Dementia↗

PubMed2005

[Influential variables on intention and action to quit smoking between adolescent smokers and adult smokers-based on the transtheoretical model].

PURPOSE: This study identified and compared influential variables on intention and action to quit smoking between adolescent smokers and adult smokers. METHODS: For the selection of variables, the transtheoretical theory was used. A survey was conducted with 376 adolescent smokers in 4 high schools and 451 adult smokers in community settings in South Korea. Discriminant analysis was used for data analysis. RESULTS: The variables of adolescent smokers that predicted an intention to quit smoking were: smoking temptation, self re-evaluation, counter conditioning and stimulus control. The variables that predicted an action to quit smoking were: self-efficacy for smoking abstinence, pros for smoking, self reevaluation, and self liberation. The variables of adult smokers that predicted an intention to quit were: smoking temptation, pros for smoking, cons for smoking, self reevaluation. The variables that self liberation and predicted an action to quit smoking were: self efficacy for smoking abstinence, smoking temptation, and counter conditioning. CONCLUSIONS: Developing stage specific smoking intervention methods based on different ways of how individuals make a decision to quit smoking within their contexts needs to be done.

Adolescent↗

PubMed2004

-93G-->A polymorphism of hMLH1 and risk of primary lung cancer.

Polymorphisms in DNA repair genes may be associated with differences in the repair capacity of DNA damage and may thereby influence an individual's susceptibility to smoking-related cancer. We investigated the association between the -93G-->A polymorphism in the hMLH1 gene and the risk of lung cancer in a Korean population. The hMLH1 -93G-->A polymorphism was typed in 372 lung cancer patients and 371 healthy controls that were frequency-matched for age and sex. There was no significant association between the hMLH1 -93G-->A genotype and the risk for adenocarcinoma or small cell carcinoma. However, the AA genotype was associated with a significantly increased risk for squamous cell carcinoma compared with both the GG genotype (adjusted OR=2.02; 95% CI=1.15-3.55; p=0.014) and the combined GG and GA genotype (adjusted OR=1.83; 95% CI=1.24-2.71; p=0.003). When the subjects were stratified by smoking exposure, the AA genotype was associated with a significantly increased risk for squamous cell carcinoma in lighter smokers (< or = 39 pack-years; adjusted OR=1.95; 95% CI=1.03-3.66; p=0.039) compared with the combined GG and GA genotype, whereas there was no significant association in heavier smokers (> 39 pack-years; adjusted OR=1.47; 95% CI=0.82-2.61). These results suggest that the hMLH1 -93G-->A polymorphism could be used as a marker of genetic susceptibility to squamous cell carcinoma of the lung.

Adaptor Proteins, Signal Transducing↗

PubMed2004

DNMT3B polymorphisms and risk of primary lung cancer.

DNA-methyltransferase-3B (DNMT3B) plays an important role in the generation of aberrant methylation in carcinogenesis. Polymorphisms and haplotypes of the DNMT3B gene may influence DNMT3B activity on DNA methylation, thereby modulating the susceptibility to lung cancer. To test this hypothesis, we investigated the association of the -283T > C (from exon 1A transcription start site) and -579G > T (from exon 1B transcription start site) polymorphisms in DNMT3B promoter, and their haplotypes with the risk of lung cancer in a Korean population. The DNMT3B genotype was determined in 432 lung cancer patients and 432 healthy controls that were frequency-matched for age and sex. Individuals with at least one -283T allele were at a significantly decreased risk of adenocarcinoma (AC) and small cell carcinoma (SM) [adjusted odds ratio (OR) = 0.48, 95% confidence interval (CI) = 0.28-0.82, P = 0.007; and adjusted OR = 0.47, 95% CI = 0.24-0.93, P = 0.03, respectively] compared with those harboring a -283CC genotype. Individuals with at least one -579G allele were also at a significantly decreased risk of AC and SM (adjusted OR = 0.47, 95% CI = 0.28-0.81, P = 0.006; and adjusted OR = 0.51, 95% CI = 0.26-0.99, P = 0.048, respectively) compared with those having a -579TT genotype. The -283T allele was linked with the -579G allele, and haplotype -283T/-579G was associated with a significantly decreased risk of AC (adjusted OR = 0.48, 95% CI = 0.29-0.81, P = 0.006) as compared with haplotype -283C/-579T. In a promoter assay, carriage of the -283T allele showed a significantly lower promoter activity ( approximately 50%) compared with the -283C allele (P < 0.001), but the -579G > T polymorphism did not have an affect on the DNMT3B promoter activity. These results suggest that the DNMT3B -283T > C polymorphism influences DNMT3B expression, thus contributing to the genetic susceptibility to lung cancer.

Aged↗

PubMed2003

Detection and characterization of 45 kDa platelet activating factor acetylhydrolase in cerebrospinal fluid of children with meningitis.

Platelet activating factor acetylhydrolase (PAF-AH) activity has been identified in cerebrospinal fluid (CSF) samples taken from children with meningitis. We reported that PAF-AH activity is significantly increased, by about 3 fold, in patients with meningitis compared to control subjects. Because of limited knowledge about this enzyme in CSF, we examined the biochemical properties of CSF PAF-AH. PAF-AH of CSF was calcium independent, showed a broad pH spectrum and was relatively heat stable. In addition, this enzyme activity was strongly inhibited by phenylmethanesulfonyl fluoride (PMSF), partially inhibited by p-bromophenacylbromide (p-BPB), uninhibited by iodoacetamide, and moderately stimulated by dithiothreitol (DTT). PAF-AH of CSF did not degrade phospholipid with a long chain fatty acyl group at sn-2 position. This enzyme hydrolyzed PAF and oxidatively modified phosphatidylcholine. Furthermore, we identified a monomeric polypeptide with a molecular weight of approximately 45 kDa by Western blot using human plasma PAF-AH antibody. These results suggested that plasma type PAF-AH activity exist in CSF taken from children with meningitis.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗