Chonbuk National University

About: Chonbuk National University is a education organization based out in Jeonju, South Korea. It is known for research contribution in the topics: Apoptosis & Graphene. The organization has 14820 authors who have published 28884 publications receiving 554131 citations.

Current characteristics of dialysis therapy in Korea: 2015 registry data focusing on elderly patients.

Abstract: Because of increases in the elderly population and diabetic patients, the proportion of elderly among dialysis patients has rapidly increased during the last decades. The mortality and morbidity of these elderly dialysis patients are obviously much higher than those of young patients, but large analytic studies about elderly dialysis patients' characteristics have rarely been published. The registry committee of the Korean Society of Nephrology has collected data about dialysis therapy in Korea through an Internet online registry program and analyzed the characteristics. A survey on elderly dialysis patients showed that more than 50% of elderly (65 years and older) patients had diabetic nephropathy as the cause of end-stage renal disease, and approximately 21% of elderly dialysis patients had hypertensive nephrosclerosis. The proportion of elderly hemodialysis (HD) patients with native vessel arteriovenous fistula as vascular access for HD was lower than that of young (under 65 years) HD patients (69% vs. 80%). Although the vascular access was poor and small surface area dialyzers were used for the elderly HD patients, the dialysis adequacy data of elderly patients were better than those of young patients. The laboratory data of elderly dialysis patients were not very different from those of young patients, but poor nutrition factors were observed in the elderly dialysis patients. Although small surface area dialyzers were used for elderly HD patients, the urea reduction ratio and Kt/V were higher in elderly HD patients than in young patients.

Peroxisome proliferator activated receptor-γ modulates reactive oxygen species generation and activation of nuclear factor-κB and hypoxia-inducible factor 1α in allergic airway disease of mice

Abstract: Background Reactive oxygen species (ROSs) play a crucial role in the pathogenesis of airway inflammation. Peroxisome proliferator activated receptor (PPAR)-γ is also involved in airway inflammation. We have demonstrated that the administration of PPARγ agonists or adenovirus carrying PPARγ cDNA (AdPPARγ) reduced bronchial inflammation and airway hyperresponsiveness. However, the effects of PPARγ on ROS generation in conditions associated with airway inflammation have not been clarified. Objective This study aimed to investigate the effects of the PPARγ on ROS generation in allergic airway disease of mice. Methods We have used a female C57BL/6 mouse model for allergic airway disease to determine the role of PPARγ. Results In this study with an ovalbumin-induced murine model of allergic airway disease, the increased ROS generation and the increased expression of T H 2 cell cytokines, adhesion molecules, chemokines, and vascular endothelial growth factor in lungs after ovalbumin inhalation were significantly reduced by the administration of PPARγ agonists or AdPPARγ. We also showed that the increased nuclear factor-κB and hypoxia-inducible factor 1α levels in nuclear protein extracts of lung tissues after ovalbumin inhalation were decreased by the administration of PPARγ agonists or AdPPARγ. Conclusion These results indicate that the effects of PPARγ are mediated by the modulation of ROS generation and activation of redox-sensitive transcription factor nuclear factor-κB and HIF-1α in allergic airway disease of mice. Clinical implications Thus, these findings provide a pivotal molecular mechanism for the use of PPARγ agonists to prevent and/or treat asthma and other airway inflammatory disorders.

Preparation and characterization of MPEG-PCL diblock copolymers with thermo-responsive sol-gel-sol phase transition

Abstract: MPEG–PCL diblock copolymers consisting of methoxy polyethylene glycol (MPEG, 750 g/mol) and poly(ϵ-caprolactone) (PCL) were synthesized by ring-opening polymerization. Aqueous solutions of the synthesized diblock copolymers were prepared by dissolving the MPEG–PCL diblock copolymers at concentrations in the range of 0–20 wt %. When the PCL molecular weight was 3000 or greater, the polymer was only partially soluble in water. As the temperature was increased from room temperature, the diblock copolymer solutions showed two phase transitions: a sol-to-gel transition and a gel-to-sol transition. The sol-to-gel phase transition temperature decreased substantially with increasing PCL length. The sol–gel–sol transition with the increase in temperature was confirmed by monitoring the viscosity as a function of temperature. The temperature ranges of the phase transitions measured by the tilting method were in full agreement with those determined from the viscosity measurements. The maximum viscosity of the copolymer solution increased with increasing hydrophobicity of the diblock copolymer and with increasing copolymer concentration. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analyses revealed that the diblock copolymers exhibited crystalline domains that favored the formation of an aggregated gel because of the tight aggregation and strong packing interactions between PCL blocks. Scanning electron micrographs of the diblock copolymer solutions in the sol state showed interconnected polyhedral pore structures, whereas those of the gel state revealed a fibrillar-like morphology. Atomic force microscope (AFM) studies of the sol and gel surfaces showed that the sol surface was covered with fine globular particles, whereas the gel surface was covered with particles in micron-scale irregular islets. These findings are consistent with uniform mixing of the diblock copolymer and water in the sol state, and aggregation of PCL blocks in the gel state. In conclusion, we confirm that the MPEG–PCL diblock copolymer solution exhibited a sol–gel–sol transition as a function of temperature. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5413–5423, 2006