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Seung Woo Lee

Publications and source records attributed to Seung Woo Lee.

14 recordsLinked to original sources
PubMed2006

Separation of tricomponent protein mixtures with triblock nanorods.

Two-component triblock magnetic nanorods with gold end blocks and nickel interior blocks have been synthesized and used as affinity templates for the simultaneous and efficient separation of a three-component protein mixture. The gold blocks were selectively functionalized with 11-amino-1-undecanethiol, and then glutaraldehyde was used to covalently attach nitrostreptavidin to them. His-tagged proteins bind to the nickel block and biotin-tagged proteins bind to the functionalized gold ends, allowing one to separate a mixture of three proteins with a single material. Each surface-bound protein can be released selectively using imidazole for the His-tagged protein and biotin for the biotinylated protein.

Acetates↗
PubMed2006

The correlation between organic matrices and biominerals (myostracal prism and folia) of the adult oyster shell, Crassostrea gigas.

The organic membrane at the interface between the myostracum (aragonite) and folia (calcite) was obtained and identified as a chitin-like macromolecule after chemical treatment. It was confirmed that the organic membrane was faced to the crystal (001) plane of the myostracum and folia. The secondary structures in soluble protein of the myostracum and the folia of oyster shell were identified as a great quantity of beta-structure. The acidic amino acids, Asp and Glu, to play a role as templates on shell formation were confirmed in the myostracum and the folia.

Animals↗
PubMed2006

Primary structure of myostracal prism soluble protein (MPSP) in oyster shell, Crassostrea gigas.

Soluble protein (MPSP, myostracal prism soluble protein) obtained from myostracum in oyster shell (Crassostrea gigas) was characterized using biochemical and molecular biological techniques. From an analysis of secondary protein structure, it was shown that beta-structure was predominant in MPSP. And via in vitro assays, the relation of MPSP to biomineral phase and morphology was studied. SDS-PAGE revealed one major protein band of 20 kDa. An amino acid sequence of 160 amino acids was deduced for myostracum by characterization of the complementary DNA encoding the protein. The deduced protein was composed of a high proportion of Gly and Asp, typifying a calcium-binding protein for shell formation, and a relatively high proportion of Val, Ala and Ile, typifying an adhesive protein. In contrast to prevailing expectations, (Gly-Asp)n-type sequence motifs exist in MPSP, demanding a revision of previous theories of protein-mineral interactions. The cDNA sequence of myostracum is elucidated for the first time.

Animals↗
PubMed2006

DPN-generated nanostructures as positive resists for preparing lithographic masters or hole arrays.

Experiments that utilize structures generated by dip-pen nanolithography (DPN) as positive resists for fabricating nanohole arrays and lithographic masters are described. The technique takes advantage of the difference in desorption potentials for patterned structures made from 16-mercaptohexadecanoic acid (MHA) and 1-octadecanethiol (ODT), respectively. In this approach, patterns of MHA on gold are generated by DPN, and surrounding areas are passivated by ODT. Electrochemistry is used to selectively remove the MHA nanofeatures made by DPN. The exposed gold can be used as an electrode to plate silver from solution, generating raised features and structures that can be transferred to PDMS to make a lithographic master, or alternatively, they can be etched to make arrays of nanoholes.

Electric Conductivity↗
PubMed2006

[Toxic hepatitis associated with carp juice ingestion].

The potential hepatotoxicity of herbal remedies and/or health foods is usually ignored in daily life. There have been cases showing the toxic hepatitis and renal failure associated with the ingestion of raw carp bile. We experienced a case of toxic hepatitis without any evidence of renal failure that was associated with carp juice ingestion. The clinical manifestations were characterized by nausea and vomiting after the ingestion of carp juice for 3 months. The diagnosis of toxic hepatitis was made on the basis of the patient's history, laboratory data, RUCAM (Russel Uclaf Causality Assessment) and the results of ultrasonography guided liver biopsy. The patient showed rapid improvement after instituting supportive therapy.

Adult↗
PubMed2005

Combined CD137 (4-1BB) and adjuvant therapy generates a developing pool of peptide-specific CD8 memory T cells.

In practice, vaccines should induce lasting and efficacious T cell immunity without promoting deleterious pathological consequences. To accomplish this goal we immunized mice with ovalbumin peptide, polyinosinic-polycytidylic and anti-CD137. Vaccinated mice retained a massive functional CD8 T cell memory pool in lymphoid and non-lymphoid tissues for >1 year. The memory T cells clonally expanded, produced substantial amounts of IFNgamma, and responded vigorously to vesicular stomatitis virus infection. To understand how the vaccine might function, we showed that the antigen-specific T cells must bear CD137 in order for optimal priming to occur. Thus, anti-CD137 agonist mAb directly stimulated peptide-specific CD8 T cells and conditioned them to survive. In contrast, CD137-deficient CD8 T cells did not survive despite CD137 expression by antigen presenting cells. Taken together, the data indicate that CD137 and adjuvant combined therapy is an efficacious vaccine strategy for immunization with non-replicating inert antigen.

Animals↗
PubMed2004

Formation of a two-dimensionally well-ordered monolayer of a peptide oligomer by a simple spin-coating process.

Oligo(N(6)-carbobenzyloxy-L-lysine) (OCBL) with n = 8 (n is the number-average degree of polymerization) was synthesized by the n-propylamine-catalyzed ring-opening polymerization of N(6)-carbobenzyloxy-L-lysine N-carboxylic anhydride, which was derived from N(6)-carbobenzyloxy-L-lysine. The formation of two-dimensionally well-ordered strip array monolayer films of the OBCL oligopeptide on graphite substrates was first succeeded by a conventional solution spin-coating process. The ordered strip array monolayer structure was characterized in detail by atomic force microscopy, and its assembly mechanism was examined.

Anhydrides↗
PubMed2004

An atypical case of Aicardi syndrome with favorable outcome.

Aicardi syndrome is a severe congenital disorder characterized by infantile spasms, chorioretinal lacunae, and agenesis or hypogenesis of the corpus callosum. A 6 month old female had developed abnormal eye movement and seizures of the complex partial type and myoclonic type. MRI pictures of the patient revealed the presence of genu associated with agenesis of the rest of corpus callosum. A funduscopic examination revealed bilateral small, solitary, pale areas with sharp borders, some of which had minimal surrounding pigmentation (chorioretinal lacunae), especially clustered around the disc, and they were more prominent on the left side. We report here on the unusual findings of a complex partial seizure, myoclonic seizure and the atypical EEG finding in addition to the well-known characteristic clinical and imaging findings of a patient with Aicardi syndrome.

Agenesis of Corpus Callosum↗
PubMed2003

Inhibition of TCR-induced CD8 T cell death by IL-12: regulation of Fas ligand and cellular FLIP expression and caspase activation by IL-12.

In this study we demonstrate the anti-apoptotic effect of IL-12 and its underlying mechanism in CD8 T cells. The prolonged stimulation of CD8 T cells with anti-CD3 alone caused apoptosis mediated by Fas and the caspase signaling pathway. However, costimulation with IL-12 significantly prevented anti-CD3-induced apoptosis of CD8 T cells. IL-12 decreased the number of Fas ligand-positive CD8 T cells and inhibited the activation of caspase-8 and caspase-3. In addition, IL-12 up-regulated cellular FLIPs but not Bcl-2 family proteins or cellular inhibitor of apoptosis proteins. These data suggest that IL-12 provides survival signals to CD8 T cells by down-regulating Fas ligand and up-regulating cellular FLIPs, followed by inhibiting caspase activation, which implies a role for IL-12 in peripheral responses of CD8 T cells in vivo.

Animals↗
PubMed2002

IL-12 provides proliferation and survival signals to murine CD4+ T cells through phosphatidylinositol 3-kinase/Akt signaling pathway.

IL-12 is a pleiotropic cytokine that plays an important role in innate and adaptive immunity. IL-12 induces T cell proliferation and IFN-gamma secretion from activated T cells. It was also reported that IL-12 prevents apoptosis of CD4(+) T cells. However, the signaling mechanism that regulates these IL-12-induced responses is poorly understood yet. In this study, we demonstrated that IL-12 activates phosphatidylinositol 3-kinase (PI3K)/Akt pathway in murine CD4(+) T cells, and that this signaling pathway is required for IL-12-induced T cell proliferation and antiapoptotic function, but not for IFN-gamma induction. Through PI3K/Akt pathway, IL-12 up-regulates the expression of cell cycle-related molecule such as cyclin D3, and antiapoptotic molecules such as Bcl-2 and cellular inhibitors of apoptosis proteins-2, followed by down-regulation of active caspase-3. These results suggest that PI3K/Akt pathway is critical for mediating IL-12-induced CD4(+) T cell responses such as T cell proliferation and survival.

Animals↗
PubMed2002

Cutting Edge: CpG DNA inhibits dendritic cell apoptosis by up-regulating cellular inhibitor of apoptosis proteins through the phosphatidylinositide-3'-OH kinase pathway.

CpG DNA has been recognized as a powerful stimulant of dendritic cells (DCs). In this study, we demonstrate that CpG DNA inhibits spontaneous apoptosis of DCs. CpG DNA up-regulated cellular inhibitor of apoptosis proteins (cIAPs) as well as Bcl-2 and Bcl-x(L), but down-regulated active caspase-3. Although CpG DNA activated p38 mitogen-activated protein kinase, extracellular signal-related kinase, and phosphatidylinositide-3'-OH kinase (PI3K), only the blocking of PI3K inhibited the CpG DNA-induced DC survival. Moreover, while the expression of Bcl-2 and Bcl-x(L) depends on both PI3K and p38 mitogen-activated protein kinase, the up-regulation of cIAPs and the down-regulation of active caspase-3 by CpG DNA require PI3K activation, suggesting PI3K-dependent up-regulation of cIAPs in the antiapoptotic activity of CpG DNA in DCs. This study indicates that CpG DNA provides a survival signal to DCs, which might be one of mechanisms by which bacterial DNA stimulates and maintains the innate immune responses.

Animals↗