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1.  Metformin Prevents Fatty Liver and Improves Balance of White/Brown Adipose in an Obesity Mouse Model by Inducing FGF21 
Mediators of Inflammation  2016;2016:5813030.
Obesity and its associated metabolic disorders are related to the onset of fatty liver and the balance of white adipose tissue (WAT) and brown adipose tissue (BAT). We hypothesized that metformin, an effective pharmacological treatment for type 2 diabetes, would inhibit white adipogenesis, fatty liver, and metabolic dysfunction. Metformin was treated daily for 14 weeks in a high-fat dieting C57BL/6J mice. Serum biomarkers were analyzed and protein level was assessed using confocal staining or flow cytometry. The development of lipid drops in the liver cells and white adipocyte was measured using hematoxylin and eosin or Oil Red O stains. Gene expressions were analyzed with quantitative real-time PCR. Metformin treatment decreased the body weight and improved the metabolic profile of obese mice. In obese mice, metformin also induced the expression of BAT-related markers and increased fibroblast growth factor (FGF) 21 expression in the liver and in white adipocyte. Metformin suppressed white adipocyte differentiation via induction of FGF21. Metformin improves Treg/Th17 balance in CD4+ T cells in mice with high-fat diet-induced obesity. Metformin also improves glucose metabolism and metabolic disorder. Interleukin-17 deficiency also decreases inflammation in mice. Therefore, metformin may be therapeutically useful for the treatment of obesity and metabolic dysfunction.
PMCID: PMC4745345  PMID: 27057099
2.  Grim19 Attenuates DSS Induced Colitis in an Animal Model 
PLoS ONE  2016;11(6):e0155853.
DSS induced colitis is a chronic inflammatory disease characterized by inflammation in the gastrointestinal tract, which destabilizes the gut and induces an uncontrolled immune response. Although DSS induced colitis is generally thought to develop as a result of an abnormally active intestinal immune system, its pathogenesis remains unclear. Gene associated with retinoid interferon induced mortality (Grim) 19 is an endogenous specific inhibitor of STAT3, which regulates the expression of proinflammatory cytokines. In this study, we investigated the influence of GRIM19 in a DSS induced colitis mouse model. We hypothesized that Grim19 would ameliorate DSS induced colitis by altering STAT3 activity and intestinal inflammation. Grim19 ameliorated DSS induced colitis severity and protected intestinal tissue. The expression of STAT3 and proinflammatory cytokines such as IL-1β and TNF-α in colon and lymph nodes was decreased significantly by Grim19. Moreover, DSS induced colitis progression in a Grim19 transgenic mouse line was inhibited in association with a reduction in STAT3 and IL-17 expression. These results suggest that Grim19 attenuates DSS induced colitis by suppressing the excessive inflammatory response mediated by STAT3 activation.
PMCID: PMC4892643  PMID: 27258062
3.  General Strategy for Broadband Coherent Perfect Absorption and Multi-wavelength All-optical Switching Based on Epsilon-Near-Zero Multilayer Films 
Scientific Reports  2016;6:22941.
We propose a general, easy-to-implement scheme for broadband coherent perfect absorption (CPA) using epsilon-near-zero (ENZ) multilayer films. Specifically, we employ indium tin oxide (ITO) as a tunable ENZ material, and theoretically investigate CPA in the near-infrared region. We first derive general CPA conditions using the scattering matrix and the admittance matching methods. Then, by combining these two methods, we extract analytic expressions for all relevant parameters for CPA. Based on this theoretical framework, we proceed to study ENZ CPA in a single layer ITO film and apply it to all-optical switching. Finally, using an ITO multilayer of different ENZ wavelengths, we implement broadband ENZ CPA structures and investigate multi-wavelength all-optical switching in the technologically important telecommunication window. In our design, the admittance matching diagram was employed to graphically extract not only the structural parameters (the film thicknesses and incident angles), but also the input beam parameters (the irradiance ratio and phase difference between two input beams). We find that the multi-wavelength all-optical switching in our broadband ENZ CPA system can be fully controlled by the phase difference between two input beams. The simple but general design principles and analyses in this work can be widely used in various thin-film devices.
PMCID: PMC4786804  PMID: 26965195
4.  A systematic review protocol for reporting deficiencies within surgical case series 
BMJ Open  2015;5(10):e008007.
Case series are an important and common study type in surgical literature. There is evidence that key data are excluded from published case series, and currently no reporting guideline exists for case series. There is, therefore, the potential to change practices and improve the reporting of case series. Reporting guidelines have been shown to be efficacious in raising the bar for reporting quality. We present our protocol for the first stage of guideline development—a systematic review of previously identified deficiencies in how surgical case series are reported.
Methods and analysis
Electronic searches will be conducted on MEDLINE, EMBASE, Cochrane Methods Register, Science Citation Index and Conference Proceedings Citation Index, from the start of indexing until 5 November 2014. The electronic search strategy was developed with an information specialist. Two independent researchers will identify articles for inclusion, specifically those that describe reporting deficiencies within surgical case series. Data will be extracted to specifically focus on the deficiencies of reporting. These will be categorised according to their type, and other identified issues will also be presented. Data will be presented with descriptive statistics to determine frequently missing types of data, and the commonest reporting issues tabulated.
Ethics and dissemination
The authors hope to disseminate the findings as widely as possible, irrespective of results, as these will add to the wider corpora of information on this subject. The systematic review will be published in a peer-reviewed journal and will be presented at a wide range of national and international conferences. Ultimately, this will inform a Delphi process for the development of a surgical case series reporting guideline.
Protocol registration
PMCID: PMC4606443  PMID: 26438134
6.  Prasugrel-Induced Hypersensitivity Skin Reaction 
Korean Circulation Journal  2014;44(5):355-357.
We report a case of hypersensitivity skin reaction to prasugrel. The patient exhibited a generalized skin rash after treatment with prasugrel, which was resolved after discontinuation of prasugrel and substitution to clopidogrel. Clopidogrel was successfully administered as an alternative to prasugrel without any signs of further hypersensitivity.
PMCID: PMC4180615  PMID: 25278991
Prasugrel; Clopidogrel; Thienopyridine; Hypersensitivity; Exanthema
7.  EGCG Attenuates Autoimmune Arthritis by Inhibition of STAT3 and HIF-1α with Th17/Treg Control 
PLoS ONE  2014;9(2):e86062.
Epigallocatechin-3-gallate (EGCG) is a green tea polyphenol exerting potent anti-oxidant and anti-inflammatory effects by inhibiting signaling and gene expression. The objective of the study was to evaluate the effect of EGCG on interleukin (IL)-1 receptor antagonist knockout (IL-1RaKO) autoimmune arthritis models. IL-1RaKO arthritis models were injected intraperitoneally with EGCG three times per week after the first immunization. EGCG decreased the arthritis index and showed protective effects against joint destruction in the IL-1RaKO arthritis models. The expression of pro-inflammatory cytokines, oxidative stress proteins, and p-STAT3 (Y705) and p-STAT3 (S727), mTOR and HIF-1α were significantly lower in mice treated with EGCG. EGCG reduced osteoclast markers in vivo and in vitro along with anti-osteoclastic activity was observed in EGCG-treated IL-1RaKO mice. The proportion of Foxp3+ Treg cells increased in the spleens of mice treated with EGCG, whereas the proportion of Th17 cells reduced. In vitro, p-STAT3 (Y705) and p-STAT3 (S727), HIF1α and glycolytic pathway molecules were decreased by EGCG. EGCG suppressed the activation of mTOR and subsequently HIF-1α, which is considered as a metabolic check point of Th17/Treg differentiation supporting the therapeutic potential of EGCG in autoimmune arthritis.
PMCID: PMC3928092  PMID: 24558360
9.  Factors Associated with Metabolic Syndrome and Related Medical Costs by the Scale of Enterprise in Korea 
The purpose of this study was to identify the risk factors of metabolic syndrome (MS) and to analyze the relationship between the risk factors of MS and medical cost of major diseases related to MS in Korean workers, according to the scale of the enterprise.
Data was obtained from annual physical examinations, health insurance qualification and premiums, and health insurance benefits of 4,094,217 male and female workers who underwent medical examinations provided by the National Health Insurance Corporation in 2009. Logistic regression analyses were used to the identify risk factors of MS and multiple regression was used to find factors associated with medical expenditures due to major diseases related to MS.
The study found that low-income workers were more likely to work in small-scale enterprises. The prevalence rate of MS in males and females, respectively, was 17.2% and 9.4% in small-scale enterprises, 15.9% and 8.9% in medium-scale enterprises, and 15.9% and 5.5% in large-scale enterprises. The risks of MS increased with age, lower income status, and smoking in small-scale enterprise workers. The medical costs increased in workers with old age and past smoking history. There was also a gender difference in the pattern of medical expenditures related to MS.
Health promotion programs to manage metabolic syndrome should be developed to focus on workers who smoke, drink, and do little exercise in small scale enterprises.
PMCID: PMC3923330  PMID: 24472134
Worker; Metabolic syndrome; Medical cost; Scale of enterprise
10.  Obesity aggravates the joint inflammation in a collagen-induced arthritis model through deviation to Th17 differentiation 
Experimental & Molecular Medicine  2012;44(7):424-431.
White fat cells secrete adipokines that induce inflammation and obesity has been reported to be characterized by high serum levels of inflammatory cytokines such as IL-6 and TNF-α. Rheumatoid arthritis (RA) is a prototype of inflammatory arthritis, but the relationship between RA and obesity is controversial. We made an obese inflammatory arthritis model: obese collagen-induced arthritis (CIA). C57BL/6 mice were fed a 60-kcal high fat diet (HFD) from the age of 4 weeks and they were immunized twice with type II collagen (CII). After immunization, the obese CIA mice showed higher arthritis index scores and histology scores and a more increased incidence of developing arthritis than did the lean CIA mice. After treatment with CII, mixed lymphocyte reaction also showed CII-specific response more intensely in the obese CIA mice than lean CIA. The anti-CII IgG and anti-CII IgG2a levels in the sera of the obese CIA mice were higher than those of the lean CIA mice. The number of Th17 cells was higher and the IL-17 mRNA expression of the splenocytes in the obese CIA mice was higher than that of the lean CIA mice. Obese CIA mice also showed high IL-17 expression on synovium in immunohistochemistry. Although obesity may not play a pathogenic role in initiating arthritis, it could play an important role in amplifying the inflammation of arthritis through the Th1/Th17 response. The obese CIA murine model will be an important tool when we investigate the effect of several therapeutic target molecules to treat RA.
PMCID: PMC3406287  PMID: 22513335
arthritis, experimental; inflammation; mice; obesity; Th17 cells
11.  Factors Affecting Public Prejudice and Social Distance on Mental Illness: Analysis of Contextual Effect by Multi-level Analysis 
While there have been many quantitative studies on the public's attitude towards mental illnesses, it is hard to find quantitative study which focused on the contextual effect on the public's attitude. The purpose of this study was to identify factors that affect the public's beliefs and attitudes including contextual effects.
We analyzed survey on the public's beliefs and attitudes towards mental illness in Korea with multi-level analysis. We analyzed the public's beliefs and attitudes in terms of prejudice as an intermediate outcome and social distance as a final outcome. Then, we focused on the associations of factors, which were individual and regional socio-economic factors, familiarity, and knowledge based on the comparison of the intermediate and final outcomes.
Prejudice was not explained by regional variables but was only correlated with individual factors. Prejudice increased with age and decreased by high education level. However, social distance controlling for prejudice increased in females, in people with a high education level, and in regions with a high education level and a high proportion of the old. Therefore, social distance without controlling for prejudice increased in females, in the elderly, in highly educated people, and in regions with a high education and aged community.
The result of the multi-level analysis for the regional variables suggests that social distance for mental illness are not only determined by individual factors but also influenced by the surroundings so that it could be tackled sufficiently with appropriate considering of the relevant regional context with individual characteristics.
PMCID: PMC3324720  PMID: 22509449
Attitude; Mental illness; Multilevel analysis; Prejudice; Social distance

Results 1-11 (11)