Publications by authors named "Sangkyum Kim"

The assessment of neurotoxicity for environmental chemicals is of utmost importance in ensuring public health and environmental safety. Multielectrode array (MEA) technology has emerged as a powerful tool for assessing disturbances in the electrophysiological activity. Although human embryonic stem cell (hESC)-derived neurons have been used in MEA for neurotoxicity screening, obtaining a substantial and sufficiently active population of neurons from hESCs remains challenging.

View Article and Find Full Text PDF

Existing digital transformation research has focused on economic and environmental performance, which few studies directly explored the relationship between digital transformation and innovation. Based on the innovation factor perspective, we explored the relationship between digital transformation and innovation by using firm data between 2009 and 2019. The findings are as follows: (1) The corporate digital transformation was measured through based on textual analysis methods and it was found that digital transformation can promote corporate innovation.

View Article and Find Full Text PDF

Ifosfamide is an alkylating agent, a synthetic analogue of cyclophosphamide, used to treat various solid cancers. In this study, the toxicity of ifosfamide was evaluated using single-and multiple-dose intraperitoneal administration in rats under Good Laboratory Practice guidelines, and an additional microarray experiment was followed to support toxicological findings. A single dose of ifosfamide (50 mg/kg) did not induce any pathological changes.

View Article and Find Full Text PDF

The International Society for Cutaneous Lymphoma (ISCL) proposes a diagnostic algorithm for early mycosis fungoides (MF) that includes clinical, histological, immunophenotypical, and molecular criteria. Here, we analyzed the immunologic markers and features of T-cell clonality in 38 early MF cases and 22 non-MF cases to validate the ISCL algorithm. We found that CD5 and CD7 expression differed significantly between early MF and non-MF cases, with epidermal discordance of CD7 expression more frequently identified in early MF.

View Article and Find Full Text PDF

Chloromethylisothiazolinone (CMIT) and methylisothiazolinone (MIT) are biocidal preservatives and the active ingredients in Kathon CG, which contains ca. 1.5% mixture of CMIT and MIT at a ratio of 3:1 (CMIT/MIT).

View Article and Find Full Text PDF

Hippo signaling acts as a tumor suppressor pathway by inhibiting the proliferation of adult stem cells and progenitor cells in various organs. Liver-specific deletion of Hippo pathway components in mice induces liver cancer development through activation of the transcriptional coactivators, YAP and TAZ, which exhibit nuclear enrichment and are activated in numerous types of cancer. The upstream-most regulators of Warts, the ortholog of mammalian LATS1/2, are Kibra, Expanded, and Merlin.

View Article and Find Full Text PDF

Blueberry fruit exhibits strong antioxidant activity owing to the presence of anthocyanin. As blueberry-leaf extract (BLE) contains chlorogenic acid and flavonol glycosides, we hypothesized that phenolic-enriched BLE would improve glucose homeostasis and insulin sensitivity. In this study, we examined whether BLE administration decreases the glucose levels and enhances the pancreatic function in mice with high-fat diet (HFD)-induced obesity and diabetes.

View Article and Find Full Text PDF

Smoking is an acknowledged risk factor for vascular disorders, and vascular complication is a main outcome of diabetes. Hence, we investigated the impact of cigarette smoke on blood vessels in diabetes, postulating that smoking might aggravate diabetic vascular impairment. Sprague-Dawley rats were divided into four groups: control, cigarette smoke-exposed, diabetic, and cigarette smoke-exposed diabetic groups.

View Article and Find Full Text PDF

Activation of YAP, a Hippo pathway effector, is an important resistance mechanism to BRAF inhibitor (BRAFi) in melanoma. Emerging evidence also suggests that YAP is involved in suppression of the antitumor immune response. However, the potential direct impact of YAP activity on cytotoxic T-cell immune responses has not been explored yet.

View Article and Find Full Text PDF

Mechanical tensions are usually generated during development at spatially defined regions within tissues. Such physical cues dictate the cellular decisions of proliferation or cell cycle arrest. Yet, the mechanisms by which mechanical stress controls the cell cycle are not yet fully understood.

View Article and Find Full Text PDF

The Hippo pathway regulates the self-renewal and differentiation of various adult stem cells, but its role in cell fate determination and differentiation during liver development remains unclear. Here we report that the Hippo pathway controls liver cell lineage specification and proliferation separately from Notch signalling, using mice and primary hepatoblasts with liver-specific knockout of Lats1 and Lats2 kinase, the direct upstream regulators of YAP and TAZ. During and after liver development, the activation of YAP/TAZ induced by loss of Lats1/2 forces hepatoblasts or hepatocytes to commit to the biliary epithelial cell (BEC) lineage.

View Article and Find Full Text PDF

This paper reports the preparation of a proton-exchange membrane (PEM) with sulfonic acid (-SO3H) groups based on polyethylene (PE) films and poly(vinylidene fluoride) (PVdF) films by the radiation-induced graft polymerization (RIGP) of sodium styrene sulfonate (NaSS) in the presence of the polymerizable access agents, such as acrylic acid and pyrollidone in a methanol solution. A PEM with -SO3H based on PE and PVdF films were confirmed by ATR, XPS and contact angle measurements. The water uptake (%), graft yield (%), ion-exchange content (mmol/g), and proton conductivity (S/cm), as well as the current density (mA/cm2), and power density (mW/cm) for PEM with -SO3H groups prepared by RIGP were evaluated.

View Article and Find Full Text PDF

Background: Hyperhomocysteinemia plays an important role in the development of hepatic steatosis, and studies indicate that homocysteine-lowering treatment inhibits the development of fatty liver.

Objective: We evaluated the effects of L-serine on alcoholic fatty liver and homocysteine metabolism.

Methods: In a binge ethanol study, male C57BL/6 mice were divided into 4 groups: control, ethanol + vehicle, and ethanol + 20 or 200 mg/kg L-serine.

View Article and Find Full Text PDF

Carbon black (CB) is an industrial chemical with high potential for human exposure. Although the relationship between exposure to particulate matter (PM) and cardiovascular disease is well documented, the risk of adverse cardiovascular effects attributed to CB particles has not been clearly characterized. This study was performed to (1) investigate the effects of CB on cardiovascular system and (2) identify the target tissue or potential biomarkers.

View Article and Find Full Text PDF

Aims: This study was carried out to evaluate the hepatoprotective effect of Platycodon grandiflorum (PG) in ethanol (EtOH)-induced liver damage.

Methods And Results: PG treatment (both the total extract and saponin fraction) significantly blocked EtOH-induced oxidative stress through the preservation of activities of antioxidant enzymes in HepG2 cells. Furthermore, while the administration of EtOH to C57BL/6 mice for 6 weeks induced liver damage, along with a significant increase in plasma glutamic oxalacetic transaminase, glutamic pyruvic transaminase, hepatic triglyceride and thiobarbituric acid reactive substance levels, PG treatment significantly decreased glutamic oxalacetic transaminase, glutamic pyruvic transaminase, hepatic triglyceride and thiobarbituric acid reactive substance levels compared with the EtOH-treated control group (p < 0.

View Article and Find Full Text PDF

Corynebacterium ammoniagenes N424 was metabolically modified to isolate overproducers of deoxycytidine. Inosine auxotrophy (ino) was initially introduced to prevent the flow of PRPP (phosphoribosyl pyrophosphate) into the purine biosynthetic pathway by random mutagenesis using N-methyl-N'-nitro-N-nitrosoguanidine. Following that, mutants possessing hydroxyurea resistance (HU(r)) were isolated to increase the activity of ribonucleoside diphosphate reductase, which catalyzes the reduction of ribonucleoside diphosphate to deoxyribonucleoside diphosphate.

View Article and Find Full Text PDF

As part of an ongoing study focused on the discovery of anti-influenza agents from plants, four new (1-4) and 10 known (5-14) C-methylated flavonoids were isolated from a methanol extract of Cleistocalyx operculatus buds using an influenza H1N1 neuraminidase inhibition assay. Compounds 4, 7, 8, and 14, with a chalcone skeleton, showed significant inhibitory effects on the viral neuraminidases from two influenza viral strains, H1N1 and H9N2. Compound 4 showed the strongest inhibitory activity against the neuraminidases from novel influenza H1N1 (WT) and oseltamivir-resistant novel H1N1 (H274Y mutant) expressed in 293T cells with IC50 values of 8.

View Article and Find Full Text PDF

Platycodon grandiflorum (PG) (Korean name, Doraji; Chinese name, Jiegeng; and Japanese name, Kikyo) is a perennial plant in the Campanulaceae family that contains triterpenoid saponins, carbohydrates, and fibers. This study was carried out to investigate effects of root of PG on fatty liver inhibition in high fat diet (HFD)-fed C57BL/6 mice. C57BL/6 mice were divided into control, total extract of PG (T-PG, 500 mg/kg) and saponin fraction (S-PG, 50 mg/kg)-treated groups.

View Article and Find Full Text PDF

Glassy cell carcinoma (GCC) has been believed to have originated from reserve or uncommitted cells as a poorly differentiated adenosquamous carcinoma. This study includes immunoprofiles of p63, cytokeratin 17 (CK17), and CD44 to clarify which lineage of GCC is committed to human papillomavirus (HPV) detection, and to verify whether or not HPV plays a role in GCC. Nine uterine GCCs showing overwhelmingly glassy features were evaluated by an HPV genotyping chip and by immunohistochemistry for E-cadherin, CD44, p63, CEA, erb-B2, cytokeratin 17, and p16.

View Article and Find Full Text PDF

Symplastic glomus tumors are defined as glomus tumors with a high-grade nuclear pleomorphism in the absence of any other malignant features, such as large size, deep location, infiltrative growth, mitotic activity, or necrosis. Only 11 cases have been reported so far in the English literature. It could be a challenge for pathologists who have no experience with it because the tumor can show marked nuclear atypia and pleomorphism.

View Article and Find Full Text PDF

A 69-year-old woman with dyspepsia and poor oral intake was diagnosed as advanced gastric cancer. Clinical staging was stage IV with inoperable status, and thus, three cycles of palliative chemotherapy with paclitaxel and cisplatin were performed. Follow up endoscopy and positron emission tomography with computed tomography (PET-CT) revealed marked decrease in the primary stomach lesion and metastatic lymph nodes.

View Article and Find Full Text PDF

Background: A nearly complete collection of gene-deletion mutants (96% of annotated open reading frames) of the yeast Saccharomyces cerevisiae has been systematically constructed. Tag microarrays are widely used to measure the fitness of each mutant in a mutant mixture. The tag array experiments can have a complex experimental design, such as time course measurements and drug treatment with multiple dosages.

View Article and Find Full Text PDF