• Korean Journal of Food Science and Technology
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• v.39 no.6
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• pp.701-707
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• 2007

Anti-diabetic effect of Platycodi radix (PR) extract fractions was determined if vitro by investigating insulin-like action, insulin sensitizing action, glucose-stimulated insulin secretion, gene expression related to ${\beta}-cell$ function and mass, and ${\alpha}$-glucoamylase suppressing action. Insulin-like activity was not promoted by the treatment of PR methanol factions in 373-L1 fibroblast. However, treatment with 0, 20 and 100% PR methanol fractions along with 1 ng/mL insulin increased insulin-stimulated glucose uptake in 373-L1 adipocytes. In addition, the treatment of 0% and 100% methanol fractions along with differentiation inducers significantly increased the differentiation of 373-L1 fibroblasts to adipocytes. These fractions may contain insulin sensitizer. The 20%, 80% and 100% methanol fractions enhanced glucose-stimulated insulin secretion in Min6 cells, insulin secreting cell line. This was related to the mechanism to promote glucose sensing and ${\beta}-cell$ proliferation, which was regulated by the induction of IRS-2, glucokinase and PDX-1 genes. As expected, 20, 80 and 100% methanol fractions increased mRNA levels of IRS-2, glucokinase and PDX-1 genes. However, PR fractions did not affect the ${\alpha}-glucoamylase$ activity in vitro. These data suggested that PR extract fractions have anti-diabetic actions through improving insulin sensitization, glucose-stimulated insulin secretion, and ${\beta}-cell$ proliferation. Therefore, PR extracts can be beneficial for anti-diabetic treatment in lean diabetic patients.

• Bulletin of the Korean Mathematical Society
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• v.54 no.3
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• pp.1023-1036
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• 2017

In this paper, we study the existence of positive solutions to the p-Kirchhoff elliptic equation involving general subcritical growth $(a+{\lambda}{\int_{\mathbb{R}^N}{\mid}{\nabla}u{\mid}^pdx+{\lambda}b{\int_{\mathbb{R}^N}{\mid}u{\mid}^pdx)(-{\Delta}_pu+b{\mid}u{\mid}^{p-2}u)=h(u)$, in ${\mathbb{R}}^N$, where a, b > 0, ${\lambda}$ is a parameter and the nonlinearity h(s) satisfies the weaker conditions than the ones in our known literature. We also consider the asymptotics of solutions with respect to the parameter ${\lambda}$.

• Korean Chemical Engineering Research
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• v.43 no.5
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• pp.595-602
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• 2005

In order to purify diethylene glycol as main impurity included in p-dioxanone, SLE (solid-liquid equilibria) and mixture density on two components system of p-dioxanone and diethylene glycol were measured and a layered melt crystallization with seed has been applied. The SLE of p-dioxanone and diethylene glycol were a simple eutectic system and the temperature and PDX concentration at eutectic point were 0.08 and 246 K, respectively. Densities of their binary mixtures were well fitted by the best correlation equation, ${\rho}_l=0.405+1.361x+0.002T-0.004xT$. In the melt crystallization, the growth rate (G) was proportional to the 1.5th power of the subcooling degree. The effective distribution coefficient ($K_{eff}$) as the degree of impurity removal was observed to increase with increasing the growth rate and initial p-dioxanone concentration. And also, $K_{eff}$ was correlated with Z function using Wintermantel's model such as $K_{eef}=-0.0604+6.392{\times}Z$. Finally, PDX purity through the optimization of this process can be obtained over 99%.

• Molecules and Cells
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• v.39 no.2
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• pp.77-86
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• 2016

Cancer is a heterogeneous disease caused by diverse genomic alterations in oncogenes and tumor suppressor genes. Despite recent advances in high-throughput sequencing technologies and development of targeted therapies, novel cancer drug development is limited due to the high attrition rate from clinical studies. Patient-derived xenografts (PDX), which are established by the transfer of patient tumors into immunodeficient mice, serve as a platform for co-clinical trials by enabling the integration of clinical data, genomic profiles, and drug responsiveness data to determine precisely targeted therapies. PDX models retain many of the key characteristics of patients' tumors including histology, genomic signature, cellular heterogeneity, and drug responsiveness. These models can also be applied to the development of biomarkers for drug responsiveness and personalized drug selection. This review summarizes our current knowledge of this field, including methodologic aspects, applications in drug development, challenges and limitations, and utilization for precision cancer medicine.

• Journal of the Chungcheong Mathematical Society
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• v.31 no.2
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• pp.231-237
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• 2018

Hardy's inequality is refined non-trivially as the form $${\int_{0}^{{\infty}}}\{{\frac{1}{x}}{\int_{0}^{x}}f(t)dt\}^pdx{\leq}Q_f{\times}({\frac{p}{p-1}})^p{\int_{0}^{x}}f^p(x)dx$$ for some $Q_f:0{\leq}Q_f{\leq}1$. $P{\acute{o}}lya$-Knopp's inequality is also refined by the similar form.

• 대한생식의학회:학술대회논문집
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• 2006.06a
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• pp.160.1-160.1
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• 2006

• Journal of the Korean Mathematical Society
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• v.47 no.6
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• pp.1317-1328
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• 2010

In this paper, we study the properties of positive solutions for the reaction-diffusion equation $u_t$ = $\Delta_u+{\int}_\Omega u^pdx-ku^q$ in $\Omega\times(0,T)$ with nonlocal nonlinear boundary condition u (x, t) = ${\int}_{\Omega}f(x,y)u^l(y,t)dy$ $\partial\Omega\times(0,T)$ and nonnegative initial data $u_0$ (x), where p, q, k, l > 0. Some conditions for the existence and nonexistence of global positive solutions are given.

• 대한생식의학회:학술대회논문집
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• 2004.11a
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• pp.40-41
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• 2004

• Development and Reproduction
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• v.23 no.4
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• pp.391-399
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• 2019

Nicotinamide is used to maturate pancreatic progenitors from embryonic stem cells (ESCs) into insulin-producing cells (IPCs). It has been known that nicotinamide inhibits the enzymatic activity of SIRT1, an NAD⁺-dependent deacetylase. Here we show that SIRT1 knockdown enhances the differentiation of human ESCs into IPCs. SIRT1 knockdown enhances the clustering size of IPCs and the expression of pancreatic genes including c-peptide, pancreas/duodenum homeobox protein 1 (PDX1), insulin, somatostatin, glucagon and Nkx6.1 in human ESC-derived IPCs. In addition, We found that IPCs differentiated from SIRT1 knockdowned human ESCs have more zinc compared to those from control human ESCs. Our data suggest that SIRT1 negatively regulates the differentiation of β cells from human ESCs.

• BMB Reports
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• v.51 no.5
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• pp.255-260
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• 2018

Wntless/GPR177 functions as WNT ligand carrier protein and activator of $WNT/{\beta}$-catenin signaling, however, its molecular role in gastric cancer (GC) has remained elusive. We investigated the role of GPR177 in gastric tumorigenesis and provided the therapeutic potential of a clinical development of anti-GPR177 monoclonal antibodies. GPR177 mRNA expression was assessed in GC transcriptome data sets (GSE15459, n = 184; GSE66229, n = 300); protein expression was assessed in independent patient tumor tissues (Yonsei TMA, n = 909). GPR177 expression were associated with unfavorable prognosis [log-rank test, GSE15459 (P = 0.00736), GSE66229 (P = 0.0142), and Yonsei TMA (P = 0.0334)] and identified as an independent risk predictor of clinical outcomes: GSE15459 [hazard ratio (HR) 1.731 (95% confidence interval; CI; 1.103-2.715), P = 0.017], GSE66229 [HR 1.54 (95% CI, 1.10-2.151), P = 0.011], and Yonsei TMA [HR 1.254 (95% CI, 1.049-1.500), P = 0.013]. Either antibody treatment or GPR177 knockdown suppressed proliferation of GC cells and sensitized cells to apoptosis. And also inhibition of GPR177 suppresses in vitro and in vivo tumorogenesis in GC cells and inhibits $WNT/{\beta}$-catenin signaling. Finally, targeting and inhibition of GPR177 with antibody suppressed tumorigenesis in PDX model. Together, these results suggest GPR177 as a novel candidate for prognostic marker as well as a promising target for treatment of GC patients.