Young Dae Kim

Amelioration of experimental autoimmune encephalomyelitis by probiotic mixture is mediated by a shift in T helper cell immune response

The immunomodulatory effect of probiotics has been shown mainly in gastro-intestinal immune disorders and little information is available on the inflammation of central nervous system. Recently we reported that IRT5 probiotics, a mixture of 5 probiotics, could suppress diverse experimental inflammatory disorders. In this study, we evaluated the prophylactic and therapeutic effects of IRT5 probiotics in experimental autoimmune encephalomyelitis (EAE), a T cell mediated inflammatory autoimmune disease of the central nervous system. Pretreatment of IRT5 probiotics before disease induction significantly suppressed EAE development. In addition, treatment with IRT5 probiotics to the ongoing EAE delayed the disease onset. Administration of IRT5 probiotics inhibited the pro-inflammatory Th1/Th17 polarization, while inducing IL10(+) producing or/and Foxp3(+) regulatory T cells, both in the peripheral immune system and at the site of inflammation. Collectively, our data suggest that IRT5 probiotics could be applicable to modulate T cell mediated neuronal autoimmune diseases, including multiple sclerosis.

Compatibilization of immiscible poly(l-lactide) and low density polyethylene blends

Blends of poly(l-lactide) (PLA) and low density polyethylene (LDPE) were prepared by melt mixing in order to improve the brittleness of PLA. A reactive compatibilizer with glycidyl methacrylate (GMA), PE-GMA, was required as a compatibilizer due to the immiscibility between PLA and LDPE. It contributes to reduce the domain size of dispersed phase and enhance the tensile properties of PLA/LDPE blends, especially for PLA matrix blends. A reaction product between PLA and PE-GMA, which was formed during melt-mixing and considered to act as a reactive compatibilizer, was characterized using1H-NMR spectroscopy.

Electrorheological and dielectric properties of polypyrrole dispersions

The electrorheological (ER) response and dielectric properties of the polypyrrole (PPy) dispersions in mineral oil were investigated. Various PPy particles were synthesized controlling the amount of oxidant and surfactant to investigate the effect of these variables on the ER response. The ER response increases with the oxidant and surfactant amount, passes through a maximum, and then decreases with the oxidant and surfactant amount. However, the decrease in the ER response at large surfactant amounts is not so significant compared to that at large oxidant amounts. The increase in the ER response with the oxidant and surfactant amount arises from the enhanced particle polarization originated from the increased PPy conductivity. The decrease in the ER response at large oxidant amounts seems to arise from the increased conduction between the PPy particles, while that at large surfactant amounts arises from the decreased particle polarization.

The methyltransferase EZH2 is not required for mammary cancer development, although high EZH2 and low H3K27me3 correlate with poor prognosis of ER‐positive breast cancers

Enhancer of zeste homolog 2 (EZH2) catalyzes trimethylation of histone H3 lysine 27 (H3K27me3) and its demethylation is catalyzed by UTX. EZH2 levels are frequently elevated in breast cancer and have been proposed to control gene expression through regulating repressive H3K27me3 marks. However, it is not fully established whether breast cancers with different levels of H3K27me3, EZH2 and UTX exhibit different biological behaviors. Levels of H3K27me3, EZH2 and UTX and their prognostic significance were evaluated in 146 cases of breast cancer. H3K27me3 levels were higher in HER2‐negative samples. EZH2 expression was higher in cancers that were LN+, size > 20mm, and with higher tumor grade and stage. Using a Cox regression model, H3K27me3 levels and EZH2 expression were identified as independent prognostic factors for overall survival for all the breast cancers studied as well as the ER‐positive subgroup. The combination of low H3K27me3 and high EZH2 expression levels were significantly associated with shorter survival. UTX expression was not significantly associated with prognosis and there were no correlations between H3K27me3 levels and EZH2/UTX expression. To determine if EZH2 is required to establish H3K27me3 marks in mammary cancer, Brca1 and Ezh2 were deleted in mammary stem cells in mice. Brca1‐deficient mammary cancers with unaltered H3K27me3 levels developed in the absence of EZH2, demonstrating that EZH2 is not a mandatory H3K27 methyltransferase in mammary neoplasia and providing genetic evidence for biological independence between H3K27me3 and EZH2 in this tissue.

Influence of tension during oxidative stabilization on SO2 adsorption characteristics of polyacrylonitrile (PAN) based activated carbon fibers

PAN-based carbon fibers were stabilized under various tensions in the presence of air at 230 °C and sequentially activated at 950 °C following carbonization. The prepared carbon fibers were tested for their SO2 adsorption capacity using a thermogravimeter. The magnitude of tension during stabilization and gas environment were varied to study their effects on SO2 adsorption capacity. It was found that the tension during the stabilization and the gas atmosphere during activation affect the carbon fiber properties, which are closely related to the SO2 adsorption capacity. The influence of stabilization tension and activation atmosphere on the SO2 adsorption capacity appear to arise from their effects on the amount of oxygen functional groups and the surface area of carbon fiber. The highest SO2 adsorption capacity and improved mechanical strength were observed when PAN fibers were activated under steam.

Pancreatic hamartoma diagnosed after surgical resection

A pancreatic hamartoma is a rare benign lesion that may be mistaken for malignancy. A pancreatic hamartoma can present with vague, non-specific symptoms, which can be difficult to diagnose despite modern diagnostic tools. We report here a pancreatic hamartoma diagnosed after surgical resection. A 52-year-old female presented with postprandial abdominal discomfort. Abdominal computed tomography and pancreatic magnetic resonance imaging revealed a 2.2 × 2.5-cm cystic mass in the pancreatic head. The patient underwent a pylorus-preserving pancreaticoduodenectomy. The histopathological and immunohistochemical studies helped make the diagnosis of pancreatic hamartoma. Here, we report a case of pancreatic hamartoma and review the relevant medical literature.

Sclerosing angiomatoid nodular transformation of the spleen related to IgG4-associated disease: report of a case

Sclerosing angiomatoid nodular transformation (SANT) of the spleen is a rare benign vascular mass, with fewer than 100 cases documented. It is generally recognized as a vascular lesion that develops in the red pulp of the spleen; however, its pathogenesis is not clearly defined. We report a case of SANT of the spleen, which presents evidence to support the hypothesis that this disease entity is associated with IgG4-associated disease. Microscopically, the tumor was composed of multiple vascular structures separated by fibrous connective tissue and immunohistochemical examination revealed positive staining for CD31, CD34, factor VIII, and IgG4. Further research based on large number of cases is warranted to clarify the pathogenesis of this tumor.

The application of simulated moving bed chromatography for the separation between 2,6- and 2,7-dimethylnaphthalene

The possibility of applying SMB chromatography for the separation of 2,6-DMN and 2,7-DMN was investigated by numerical simulation based on the single column chromatography experimental data. It was found that 2,6-DMN could be separated from 2,7-DMN in the ODS-modified silica gel by using methanol and water as the mobile phase. A systematic method of obtaining model parameters for the SMB simulation from single column chromatography experiments was presented. The adsorption isotherms of 2,6-DMN and 2,7-DMN were obtained by the pulse method. The mass transfer kinetics was very fast, indicating that the mobile phase and the stationary phase are very close to equilibrium for both 2,6-DMN and 2,7-DMN. SMB simulation was performed by using the model parameters. Pure 2,6-DMN and 2,7-DMN can be obtained by selecting suitable operating conditions, indicating that SMB chromatography can be employed to separate 2,6-DMN and 2,7-DMN. The influence of operating parameters (feed flow rates, raffinate flow rate, and switch time) was also investigated to recommend the optimum operating conditions.

Generalized peritonitis arising from small bowel metastasis in a lung cancer patient

Symptomatic gastrointestinal metastasis from lung malignancy is rarely reported. In this report, we present a case of lung adenocarcinoma with acute abdominal pain from small bowel perforation. The patient underwent small bowel resection and the final diagnosis was metastatic adenocarcinoma originating from lung. Immunohistochemistry was positive for thyroid transcription factor-1 and cytokeratin 7 (CK7), and negative for CK20. We present this rare case and briefly review the literature.

Immunohistochemical analysis of developmental neural antigen expression in the balloon cells of focal cortical dysplasia.

Balloon cells (BC) are the histological hallmarks of focal cortical dysplasia (FCD). Expression of the neural stem cell surface marker CD133 and other developmental markers was studied in the BC of FCD using formalin-fixed paraffin-embedded tissue from nine patients with FCD. Labeling indexes were calculated for all antibodies. BC were easily identified at the gray-white matter junction and they extended into the white matter. Immunoreactivity in BC was found for the following antigens in nine patients: CD133 (six patients; 22.2 ± 7.7%), CD34 (two patients; 0.4 ± 0.3%), nestin (nine patients; 37.6 ± 8.5%), vimentin (eight patients; 59.2 ± 8.7%), glial fibrillary acid protein (six patients; 34.3 ± 10.4%), microtubule-associated protein 2 (four patients; 8.3 ± 5.0%), neurofilament-middle/high (five patients; 10.2 ± 4.6%) and synaptophysin (three patients; 4.2 ± 3.3%). Neuronal nuclei (NeuN, neuron specific nuclear protein) was not expressed in BC of any patient. The results of this study suggest that BC in patients with FCD originate from glioneuronal precursor cells and that developmental defects of neuronal and glial specifications are important in the histogenesis of FCD.