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Sung-Hoon Kim

Publications and source records attributed to Sung-Hoon Kim.

68 records · Page 4Linked to original sources
PubMed2004

Expression and function of CD8 alpha/beta chains on rat and human mast cells.

UNLABELLED: The expression and functional role of CD8 glycoprotein, a marker of cytotoxic/suppressor T lymphocytes and NK cells, were not studied on freshly isolated connective tissue type rat peritoneal mast cells, a rat mucosal type mast cell line (RBL 2H3), or human mast cell line (HMC-1). We used the reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis, immunohistochemistry and enzyme-linked immunosorbent assay. RESULTS: RT-PCR and Western blot analysis identified the presence of CD8 alpha/beta chains on the mast cells, and immunohistochemistry confirmed CD8alpha expression on rat or human mast cells. Functional studies demonstrated that stimulation of CD8 alpha/beta chains on rat mast cells induced the secretion of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), which are regarded as important mediators during infection. However, co-stimulation with stem cell factor had no effect on CD8-induced mediator secretion. Our findings demonstrate novel biological roles of CD8 molecules in mast cells.

Animals↗
PubMed2004

Development of polymerase chain reaction and comparison with in situ hybridization for the detection of Haemophilus parasuis in formalin-fixed, paraffin-embedded tissues.

DNA extraction and nested polymerase chain reaction (PCR) were developed for the detection of Haemophilus parasuis from formalin-fixed, paraffin-embedded tissues. The results for nested PCR were compared with those determined by in situ hybridization. The optimal results obtained show that use of xylene deparaffinization, digestion with proteinase K followed by nested PCR is a reliable detection method. A distinct positive signal was detected in 20 pigs naturally infected with H. parasuis by in situ hybridization. The rate of agreement between nested PCR and in situ hybridization for the detection of H. parasuis in formalin-fixed, paraffin-embedded tissues was 100%. The nested PCR could be applied successfully to formalin-fixed, paraffin-embedded tissues for the detection of H. parasuis with bacterial isolation.

Actinobacillus pleuropneumoniae↗
PubMed2004

Identification of a locus for maturity-onset diabetes of the young on chromosome 8p23.

Maturity-onset diabetes of the young (MODY) is a subtype of diabetes defined by an autosomal dominant inheritance and a young onset. Six MODY genes have been discovered to date. To identify additional MODY loci, we conducted a genome scan in 21 extended U.S. families (15 white and 6 from minorities, for a total of 237 individuals) in which MODY was not caused by known MODY genes. Seven chromosomal regions (1q42, 2q24, 2q37, 4p13, 8p23, 11p15, and 19q12) had a parametric heterogeneity logarithm of odds (HLOD) > or =1.00 or a nonparametric logarithm of odds (LOD) > or =0.59 (P < or = 0.05) in the initial screen. After typing additional markers at these loci to reduce the spacing to 2-3 cM, significant linkage was detected on 8p23 (HLOD = 3.37 at D8S1130 and nonparametric LOD = 3.66; P = 2 x 10(-5) at D8S265), where a 4.7-Mb inversion polymorphism is located. Thirty percent of the families (6 of 21) were linked with this region. Another linkage peak on chromosome 2q37 with an HLOD of 1.96 at D2S345/D2S2968 accounted for diabetes in an additional 25% of families (5 of 21). All 6 minority families were among the 11 families linked to these loci. None of the other loci followed up had an HLOD exceeding 1.50. In summary, we have identified a MODY locus on 8p23 that accounts for diabetes in a substantial proportion of MODY cases unlinked to known MODY genes. Another novel MODY locus may be present on 2q37. Cloning these new MODY genes may offer insights to disease pathways that are relevant to the cause of common type 2 diabetes.

Adolescent↗
PubMed2004

Gene expression analysis in SV40-immortalized human breast luminal epithelial cells with stem cell characteristics using a cDNA microarray.

The epithelial compartment of the human breast comprises two distinct cell types. Type I human breast epithelial cells (HBECs) are expressing luminal epithelial cell markers and stem cell characteristics, whereas Type II HBECs show basal epithelial cell phenotypes. When defined in terms of markers for normal cell lineages, most invasive breast cancer cells correspond to the phenotype of the common luminal epithelial cell. We had developed simian virus 40-immortalized cell lines from normal HBECs with luminal and stem cell characteristics. To identify molecular changes involved in immortalization, we analyzed the differential gene expression profiles of normal and non-tumorigenic immortalized Type I HBECs using cDNA microarray with 7,448 sequence-verified clones. Out of the 7,448 genes screened, consistent gene expression changes among biological replicates included 67 in Type I HBECs and 86 in Type II HBECs for 4-fold change criteria. Surprisingly, we identified 148 genes (>2.0-fold) as being either up- or down-regulated related to immortalization: 67 genes (MYBL2, UCHL1 et al) were up-regulated, and 81 genes (IGFBP3, CDKN1A et al) were down-regulated significantly. The altered expression levels of the selected genes were subsequently confirmed by semiquantitative RT-PCR. Our studies suggest that the immortalization of Type I HBECs might be an early step in the initiation of a subset of breast cancer. Furthermore, these results will open up an avenue for more detailed understanding of breast stem cell and tumor biology.

Biomarkers↗
PubMed2003

Mylabris phalerlata induces apoptosis by caspase activation following cytochrome c release and Bid cleavage.

Mylabris phalerata (MP) is an insect that has been used for the treatment of cancer in oriental medicine. In the present study, the butanol (BuOH) fraction of MP (BFMP) was examined to determine whether it can exert anti-cancer activity through an apoptotic pathway with little toxicity. BFMP was found to have a specific cytotoxic effect on human monocytic leukemic U937 cells (IC(50) = 140 microg/ml) rather than on peripheral blood mononuclear lymphocytes (PBML, IC(50) = over 500 microg/ml). BFMP also induced the morphological changes of apoptosis, such as chromatin condensation, cell shrinking and DNA fragmentation at a concentration of 31.25 microg/ml. In addition, BFMP significantly increased the portion of apoptotic annexin-V positive cells in a dose-dependent manner, and effectively activated caspases (cysteine aspartase) cascade involving caspases 8, 9 and 3. BFMP also effectively cleaved Bid, a death agonist member of the Bcl-2 family and (poly(ADP-ribose)polymerase) (PARP) and induced the subsequent release of cytochrome c from mitochondria into the cytosol. However, it did not affect Bcl-2 and Bax expression. Taken together, these data suggest that the BuOH extract of Mylabris phalerata can induce apoptosis in U937 cells by caspase cascade activation in conjunction with cytochrome c release, induced by a product of Bid. Therefore, we conclude that BFMP has anti-cancer activity, which is achieved through apoptosis and is associated with little toxicity.

Animals↗
PubMed2003

Effects of the ethyl acetate fraction of Spatholobi caulis on tumour cell aggregation and migration.

The ethyl acetate (EA) fraction obtained from a methanol extract of Spatholobi caulis (Leguminosae) has been investigated for anti-metastatic activities in vitro. The EA fraction of Spatholobi caulis inhibited platelet aggregation induced by B16BL6 melanoma cells with an IC(50) of 50 microgram/mL. The EA fraction significantly inhibited HT1080 cancer cell invasion through a matrigel-coated filter with an IC(50) of 25 microgram/mL. Messenger RNA expression of uPA was effectively decreased in HT1080 cells by the EA fraction of Spatholobi caulis with an IC(50) of 30 microgram/mL, but the expressions of MMP-2 (matrix metalloproteinase) and TIMPs (tissue inhibitors of metalloproteinases) were not changed. These findings indicated that the EA fraction suppressed tumour cell invasion by downregulation of uPA (urokinase-type plasminogen activator). Taken together, these results suggest that the EA fraction of Spatholobi caulis may have anti-metastatic activities by blocking tumour cell-induced platelet aggregation (TCIPA) and tumour cell invasion.

Animals↗
PubMed2003

Antimetastatic and immunomodulating properties of a new herbal prescription, Bojung-bangam-tang.

We investigated the antimetastatic effect of Bojung-bangam-tang, a new herbal prescription, on liver metastasis by the inoculation of colon 26-L5 carcinoma cells into the portal vein. Oral administration of Bojung-bangam-tang for 15 days from day 7 before tumor inoculation significantly inhibited liver metastasis in a dose-dependent manner. Bojung-bangam-tang enhanced the mitogenic activity of BALB/c whole splenocytes induced by various mitogenic stimuli. Oral administration of Bojung-bangam-tang, by itself, could not induce the production of interleukin (IL)-12 or IFN-gamma by macrophages, but enhanced the potential of macrophages to produce cytokines in response to lipopolysaccharide (LPS). Experiments using macrophage- or natural killer (NK) cell-deficient mice revealed that the antimetastatic effect of Bojung-bangam-tang is mediated by macrophages rather than NK cells. Bojung-bangam-tang caused a marked increase of production of Th1 cytokine (IFN-gamma) and decrease of production of Th2 cytokine (IL-4) by splenocytes stimulated with concanavalin A (Con A). These results indicated that oral administration of Bojung-bangam-tang inhibited the liver metastasis of colon 26-L5 cells through a mechanism leading to a Th1 dominant immune state and activation of macrophages. Thus, Bojung-bangam-tang may be useful for the prevention of cancer metastasis.

Adjuvants, Immunologic↗
PubMed2003

Inhibitory effect of salmosin, a Korean snake venom-derived disintegrin, on the integrin alphav-mediated proliferation of SK-Mel-2 human melanoma cells.

We have investigated the inhibitory effect of salmosin on integrin-mediated human tumour cell proliferation. SK-Mel-2 human melanoma cell adhesion to denatured collagen or vitronectin was found to be significantly and statistically inhibited by salmosin in a dose-dependent manner (P<0.05). Moreover, the binding of SK-Mel-2 cells to salmosin-coated plates was specifically disrupted by anti-integrin alphav monoclonal antibody at 8 microg mL(-1), but not by anti-integrin monoclonal antibody. These findings indicated that salmosin inhibited the adhesion of SK-Mel-2 cells to denatured collagen by specifically blocking integrin alphav. The proliferation of SK-Mel-2 cells on a denatured collagen-coated plate was statistically and significantly inhibited by salmosin induced apoptosis in a dose-dependent manner (P<0.05). Anti-integrin alphav monoclonal antibody, anti-integrin alphavbeta3 monoclonal antibody, and synthetic RGD peptide also suppressed SK-Mel-2 cell proliferation. Several lines of experimental evidence strongly suggested that the inhibition of SK-Mel-2 cell proliferation by salmosin was due to the induction of apoptosis via the blocking of integrin alphav-mediated cell survival.

Apoptosis↗
PubMed2003

Behavior of a polypyrrole solid contact pH-selective electrode based on tertiary amine ionophores containing different alkyl chain lengths between nitrogen and a phenyl group.

We compared the slopes of the EMF responses and the response range of a solid contact electrode based on a tribenzylamine ionophore with those based on a tris(2-phenylethyl)amine ionophore and a tris(3-phenylpropyl)amine ionophore. Their slopes of the EMF responses showed, respectively, 57.7, 58.1, 59.0 mV pH(-1) (at 20 +/- 0.2 degrees C). Also, the linear pH response dynamic ranges were 2.74-10.63 for tribenzylamine-based SCEs, pH 4.47-12.59 for tris(2-phenylethyl)amine, and pH 4.60-13.24 for tris(3-phenylpropyl)amine. When the slopes of the EMF responses and the response range were considered, as the length of the replaced alkyl chain increased between the nitrogen atom and the phenyl group in the ionophore, though the dynamic range and the slopes of the EMF responses of these electrodes did not show any particularly different results, their response ranges moved toward the alkali range (shifted to pH 14). When it was directly applied to cow's milk (in pH range of 6.0-8.5), we could obtain the same satisfying results. This electrode continuously contacted a Tris 7.50 buffered solution as well as cow's milk for one month without any loss of performance. Also, especially, these electrodes showed very good results, such as stabilization of the base potential as well as the best reproducibility and response time (< 10 s).

Journal Article↗
PubMed2003

Genetic modifiers of the age at diagnosis of diabetes (MODY3) in carriers of hepatocyte nuclear factor-1alpha mutations map to chromosomes 5p15, 9q22, and 14q24.

Mutations in hepatocyte nuclear factor (HNF)-1alpha (MODY3) account for the largest proportion of maturity-onset diabetes of the young (MODY) cases in the U.S. This form of diabetes is characterized by impaired insulin secretion in response to glucose, but wide variability exists in the severity of hyperglycemia and in the age at which it becomes clinically manifest. We have previously shown that the age at onset of diabetes in MODY3 families is influenced by familial factors (including modifying genes) and exposure to diabetes in utero. To identify genes influencing the onset of MODY3, we conducted a genome scan in 13 extended MODY families in which diabetes segregates with an HNF-1alpha mutation. Linkage with age at onset of diabetes was assessed by genetic variance component analysis using SOLAR. The locus with the strongest evidence of linkage was on chromosome 14q24 (D14S588; logarithm of odds [LOD] = 2.58, P = 0.0004). This location overlaps with IDDM11 and includes SEL1L, a negative regulator of the Notch pathway that may control islet development. Linkage evidence also supported loci on 5p15 (D5S817; LOD = 2.44, P = 0.0004) and 9q22 (D9S910; LOD = 2.02, P = 0.0018). The latter matches a region linked to 2-h insulin levels in Pima Indians. Less strong linkage evidence was observed at three other regions: chromosomes 3p24 (LOD = 1.44), 7q21 (1.20), and 16q23 (1.51). Our data are consistent with the existence of multiple loci that contribute to the expression of the MODY3 phenotype. Identification of these genes will offer new insights into the pathophysiology of MODY that may, in turn, increase our understanding of the cellular events underlying more common forms of diabetes.

Age of Onset↗
PubMed2002

A case of twin pregnancy with complete hydatidiform mole and coexisting fetus following IVF-ET.

Twin pregnancy consisting of complete hydatidiform mole (H-mole) and a coexisting fetus occurs with an estimated incidence of 1 per 22,000-100,000 pregnancies. The incidence of this unusual twin pregnancy with complete H-mole and a coexisting fetus after in vitro fertilization and embryo transfer (IVF-ET) is not thought to be greater than that of general population. We present an unusual twin pregnancy with complete H-mole and a coexisting fetus that occurred following IVF-ET, which was terminated at 21 weeks of gestation and developed into nonmetastatic gestational trophoblastic tumor.

Abortion, Therapeutic↗
PubMed2002

Significance of beta2-adrenergic receptor gene polymorphism in obesity and type 2 diabetes mellitus in Korean subjects.

Catecholamines play a central role in the regulation of energy expenditure, in part stimulating lipid mobilization through lipolysis in fat cells. The beta(2)-adrenergic receptor (ADRB2) is a major lipolytic receptor in human fat cells, and a recent study has shown that common polymorphisms occurring in codons 16 and 27 of the ADRB2 gene are significantly associated with obesity and lipolytic ADRB2 function in adipose tissue. We investigated whether previously described human ADRB2 gene polymorphisms are associated with obesity and diabetes in Korean subjects. According to the World Health Organization (WHO) criteria for oral glucose tolerance testing, 57 subjects had normal glucose tolerance (NGT), 32 had impaired glucose tolerance (IGT), and 106 had diabetes mellitus. The nondiabetic group (including NGT and IGT) consisted of 46 obese (defined as those with body mass index [BMI] of >or= 27 kg/m(2)) and 43 nonobese subjects (BMI < 27 kg/m(2)). The subjects with diabetes consisted of 62 obese and 44 nonobese subjects. There was no significant difference between nonobese and obese subjects in the allele frequency of ADRB2 gene polymorphisms at codons 16 and 27. There were no significant differences in BMI, percentage body fat, waist-to-hip ratio (WHR), systolic blood pressure, diastolic blood pressure and concentrations of fasting plasma glucose, fasting serum insulin, serum low-density lipoprotein (LDL)-cholesterol, serum high-density lipoprotein (HDL)-cholesterol, serum triglyceride, and serum free fatty acids, according to ADRB2 gene polymorphisms at codons 16 and 27. The frequency of the Glu27 homozygote was 1.1%. These findings suggest that genetic variability in the ADRB2 gene may not be a major determinant for the development of obesity and diabetes in Koreans.

Adult↗
PubMed2002

The roles of ERK1/2 and p38 MAP kinases in the preventive mechanisms of mushroom Phellinus linteus against the inhibition of gap junctional intercellular communication by hydrogen peroxide.

Modulation of gap junctional intercellular communication (GJIC) is a known cellular event associated with tumor promotion. The present study was undertaken to test the potential preventive effect of mushroom Phellinus linteus extract (PL) on the inhibition of GJIC, induced by hydrogen peroxide (H(2)O(2)), in WB-F344 rat liver epithelial cells (WB cells). Cells were pre-incubated with PL (5 and 25 microg/ml) for 24 h and this was followed by co-treatment with PL and H(2)O(2) (500 microM) for 1 h. PL (at 5 and 25 microg/ml) prevented the inhibition of GJIC and blocked the hyper-phosphorylation of connexin 43 by H(2)O(2). Moreover, H(2)O(2) activated p38 kinase, extracellular signal-regulated protein kinases (ERK)1/2 and c-Jun N-terminal kinase (JNK) in WB cells. The present study indicates that PL is able to inactivate both ERK1/2 and p38 MAP kinases. However, PL did not affect the JNK pathway. For this reason, to elucidate the relation between MAP kinases and GJIC, we treated cells with PD98059 (an MEK inhibitor) and SB202190 (a p38 kinase inhibitor). These inhibitors were also found to prevent the inhibition of GJIC induced by H(2)O(2), which suggests that PL may act as a natural anticancer product by preventing the inhibition of GJIC through the inactivation of ERK1/2 and p38 MAP kinases. In addition, our results indicate that the p38 kinase signaling pathway may be closely related functionally to the gap junction in rat liver epithelial cells.

Agaricales↗