Biomedical subjects

Nam-Soon Kim

Publications and source records attributed to Nam-Soon Kim.

25 records · Page 2Linked to original sources

PubMed2005

Gene expression analysis of cultured amniotic fluid cell with Down syndrome by DNA microarray.

Complete or partial triplication of human chromosome 21 results in Down syndrome (DS). To analyze differential gene expressions in amniotic fluid (AF) cells of DS, we used a DNA microarray system to analyze 102 genes, which included 24 genes on chromosome 21, 28 genes related to the function of brain and muscle, 36 genes related to apoptosis, 4 genes related to extracellular matrix, 8 genes related to other molecular function and 2 house-keeping genes. AF cells were collected from 12 pregnancies at 16-18 weeks of gestation in DS (n=6) and normal (n=6) subjects. Our DNA microarray experiments showed that the expressions of 11 genes were altered by at least 2-folds in DS, as follows. Ten genes, COL6A1, CASP5, AKT2, JUN, PYGM, BNIP1, OSF-2, PRSS7, COL3A1, and MBLL were down-regulated and GSTT1 was only up-regulated. The differential expressions of GSTT1 and COL3A1 were further confirmed by semi-quantitative RT-PCR for each sample. The gene dosage hypothesis on chromosome 21 may explain the neurological and other symptoms of DS. However, our results showed that only two genes (COL6A1 and PRSS7), among 24 genes on chromosome 21, were down-regulated in the AF cells of DS. Our data may provide the basis for a more systematic identification of biological markers of fetal DS, thus leading to an improved understanding of pathogenesis for fetal DS.

Amniocentesis↗

PubMed2005

[Factors influencing antibiotics prescribing of primary health physicians in acute upper respiratory infections].

OBJECTIVES: To explore the factors influencing antibiotics prescription by primary health physicians for acute upper respiratory infections (URI). METHODS: We performed a survey of 370 primary health physicians randomly sampled in April, 2003. The questionnaire consisted of a prescription on the scenario of acute bronchitis case, along with opinions and reasons for prescribing antibiotics on URI. RESULTS: We found that 54.7% of the physicians prescribed antibiotics on the example case of acute bronchitis which is known as not needing antibiotics. Female physicians and ENT physicians had a greater tendency to prescribe antibiotics. The factors influencing antibiotics prescription on URI were the belief about the effectiveness of antibiotics, preference for their own experiences rather than clinical guidelines, perception of patients' expectations, and perception of competitive environment. The prescription of antibiotics in the example case was affected by how much they usually prescribe antibiotics (OR = 2.400, 95% CI = 1.470-3.917) and the physicians who thought that antibiotics were helpful for their income prescribed antibiotics more than others (OR = 6.773, 95% CI = 1.816-25.254). CONCLUSION: These findings demonstrated that the false belief on the effectiveness of antibiotics, patient's expectation of medication and fast relief of symptoms, and perception of competitive environment all affected the physicians' prescription of antibiotics on URI. It may help to find barriers to accommodate scientific evidence and clinical guidelines among physicians and to specify subgroups for education about appropriate prescription behaviors.

Adult↗

PubMed2004

Identification of novel genes associated with the response to 5-FU treatment in gastric cancer cell lines using a cDNA microarray.

The 5-Fluorouracil (5-FU) is an anticancer drug that is widely used in the treatment of cancer. To identify novel genes associated with 5-FU in gastric cancer, the time-dependent expression profiling of genes in response to 5-FU was examined in 5-FU sensitive and/or resistant gastric cancer cell lines using a 'KUGI 14 K cDNA chip' containing 14,081 unigenes obtained from human gastric cancer cell lines and tissues. By this analysis, we obtained 13 genes which are directly associated with sensitivity or resistance to 5-FU. Of these genes, 11 were found to be commonly up-regulated only in the 5-FU sensitive cell lines, and 2 were oppositely regulated in both of 5-FU sensitive and resistant cell lines. These genes were determined to be involved in cell surface, apoptosis, cell cycle and signal transduction. Of these genes, the expression levels of ZFP100, 4F2hc, FLJ11021, CSTF3, PPP1R14A, DDB2, C6orf139, CDKN1A, HOXC11 and FLJ38860 were confirmed by semi-quantitative RT-PCR. In addition, seven genes containing RRMI, UP1 and K-EST0037597 were found to be commonly up-regulated in both cell lines. In addition, the expression of genes such as TP, OPRT, TS and DPD, which have been previously known to be involved in 5-FU metabolism, were examined in both of 5-FU sensitive and resistant cell lines. These results provide not only predictive biomarkers for 5-FU sensitivity or resistance to human gastric cancer, but also a new molecular basis for understanding the mechanism of cellular cytoxicity to 5-FU.

Antimetabolites, Antineoplastic↗

PubMed2004

Identification of target proteins of N-acetylglucosaminyl-transferase V and fucosyltransferase 8 in human gastric tissues by glycomic approach.

To understand better the mechanism underlying gastric cancer and search for potential markers for gastric cancer prognosis, the proteomic analysis of gastric cancer tissues was conducted using two-dimensional gel electrophoresis and lectin blot, followed by electrospray ionization-mass spectrometry. These approaches permitted identification of glyco- or putative glycosylated proteins which may be associated with tumorigenesis. The proteins identified include molecules involved in sugar metabolism, signal transduction, proteolysis, and stress, as well as several unknown proteins, which were aberrantly glycosylated as evidenced by the L-phytohemagglutinin blot.

Fucosyltransferases↗

PubMed2004

Construction of multi-purpose vectors, pCNS and pCNS-D2, are suitable for collection and functional study of large-scale cDNAs.

To efficiently perform collection and functional studies of large-scale cDNAs, we constructed multi-functional cDNA vectors for efficient full-length cDNA cloning, direct sequencing, easy screening, and the expression of cDNA in vitro and in vivo without subcloning the cDNA into other vectors. The constructed vectors, pCNS and pCNS-D2, contain a multi-cloning site for uni-directional full-length cDNA cloning, T7 and Sp6 RNA polymerase promoters for in vitro transcription and translation, and hCMV immediate early promoter and BGH poly(A) to allow expression in mammalian cells. Using these vectors, we constructed full-length enriched cDNA libraries containing 60-75% of the full-length cDNAs using two different oligo-capping methods. The subtracted cDNA libraries could also be constructed by removing of EF1-alpha cDNA, a highly expressed cDNA. In addition, we confirmed the translation of EF1-alpha cDNA in vitro and the expression of luciferase cDNA in mammalian cells. The expression efficiency of luciferase cDNA in different cell lines, such as HeLa, Hep3B, SNU638, and SNU668, showed that pCNS vectors can highly express target genes in different cell types. These results indicated that our multi-purpose vectors, pCNS and pCNS-D2, are useful tools for the construction of full-length cDNA libraries and high-throughput based functional study of cDNAs.

Animals↗

PubMed2004

Gene cataloging and expression profiling in human gastric cancer cells by expressed sequence tags.

To understand the molecular mechanism associated with gastric carcinogenesis, we identified genes expressed in gastric cancer cell lines and tissues. Of 97,609 high-quality ESTs sequenced from 36 cDNA libraries, 92,545 were coalesced into 10,418 human Unigene clusters (Build 151). The gene expression profile was produced by counting the cluster frequencies in each library. Although the profiles of highly expressed genes varied greatly from library to library, those genes related to cell structure formation, heat shock proteins, the glycolysis pathway, and the signaling pathway were highly represented in human gastric cancer cell lines and in primary tumors. Conversely, the genes encoding immunoglobulins, ribosomal proteins, and digestive proteins were down-regulated in gastric cancer cell lines and tissues compared to normal tissues. The transcription levels of some of these genes were confirmed by RT-PCR. We found that genes related to cell adhesion, apoptosis, and cytoskeleton formation were particularly up-regulated in the gastric cancer cell lines established from malignant ascites compared to those from primary tumors. This comprehensive molecular profiling of human gastric cancer should be useful for elucidating the genetic events associated with human gastric cancer.

Base Sequence↗

PubMed2003

An improved method for constructing a full-length enriched cDNA library using small amounts of total RNA as a starting material.

We have developed an improved method for constructing a full-length cDNA library using small quantity of material by modifying the original oligo-capping method. In our devised method, total RNAs are used in sequential oligo-capping steps directly without preliminary mRNA purification. Using this method, we constructed full- length cDNA libraries from 100 mg of total RNA. These libraries contained 8x10(5) to 8x10(6) independent clones with average insert sizes of 2.0 kb. Moreover, the number of full-length cDNAs containing the translation initiation codon ATG in the constructed libraries was estimated to 60-70%. In addition, 54% of the known cDNAs had a longer 5' end than the corresponding genes in the public database. Our results show that the method can be effectively used to construct full-length enriched cDNA libraries, especially, if starting material is limited.

Base Sequence↗