Colorimetric detection of endogenous hydrogen sulfide production in living cells

Ahn, Yong Jin,Lee, Young Ju,Lee, Jaemyeon,Lee, Doyeon,Park, Hun-Kuk,Lee, Gi-Ja Elsevier 2017 Spectrochimica acta. Part A, Molecular and biomole Vol.177 No.-

<P><B>Abstract</B></P> <P>Hydrogen sulfide (H<SUB>2</SUB>S) has received great attention as a third gaseous signal transmitter, following nitric oxide and carbon monoxide. In particular, H<SUB>2</SUB>S plays an important role in the regulation of cancer cell biology. Therefore, the detection of endogenous H<SUB>2</SUB>S concentrations within biological systems can be helpful to understand the role of gasotransmitters in pathophysiology. Although a simple and inexpensive method for the detection of H<SUB>2</SUB>S has been developed, its direct and precise measurement in living cells remains a challenge. In this study, we introduced a simple, facile, and inexpensive colorimetric system for selective H<SUB>2</SUB>S detection in living cells using a silver-embedded Nafion/polyvinylpyrrolidone (PVP) membrane. This membrane could be easily applied onto a polystyrene microplate cover. First, we optimized the composition of the coating membrane, such as the PVP/Nafion mixing ratio and AgNO<SUB>3</SUB> concentration, as well as the pH of the Na<SUB>2</SUB>S (H<SUB>2</SUB>S donor) solution and the reaction time. Next, the <I>in vitro</I> performance of a colorimetric detection assay utilizing the silver/Nafion/PVP membrane was evaluated utilizing a known concentration of Na<SUB>2</SUB>S standard solution both at room temperature and at 37°C in a 5% CO<SUB>2</SUB> incubator. As a result, the sensitivity of the colorimetric assay for H<SUB>2</SUB>S at 37°C in the incubator (0.0056Abs./μM Na<SUB>2</SUB>S, R<SUP>2</SUP> =0.9948) was similar to that at room temperature (0.0055Abs./μM Na<SUB>2</SUB>S, R<SUP>2</SUP> =0.9967). Moreover, these assays were less sensitive to interference from compounds such as glutathione, <SMALL>L</SMALL>-cysteine (Cys), and dithiothreitol than to the H<SUB>2</SUB>S from Na<SUB>2</SUB>S. This assay based on the silver/Nafion/PVP membrane also showed excellent reproducibility (2.8% RSD). Finally, we successfully measured the endogenous H<SUB>2</SUB>S concentrations in live C6 glioma cells by s-(5′-adenosyl)-<SMALL>L</SMALL>-methionine stimulation with and without Cys and <SMALL>L</SMALL>-homocysteine, utilizing the silver/Nafion/PVP membrane. In summary, colorimetric assays using silver/Nafion/PVP-coated membranes can be simple, robust, and reliable tools for the detection of H<SUB>2</SUB>S that can avoid the complicated and labor-intensive analytical approach used in conventional biology. In addition, we expect that this assay will demonstrate a powerful ability to study pathophysiological pathways that involve H<SUB>2</SUB>S.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We developed a simple and facile colorimetric system for selective H<SUB>2</SUB>S gas detection. </LI> <LI> The silver/Nafion/PVP membrane was coated on the underside of a microplate cover. </LI> <LI> This assay showed high selectivity, good sensitivity, and excellent reproducibility. </LI> <LI> We successfully measured the endogenous H<SUB>2</SUB>S levels in live C6 glioma cells. </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>

REVIEW : The scientific achievements of the decades in Korean Acute Myocardial Infarction Registry

( Hyun Kuk Kim ),( Myung Ho Jeong ),( Seung Hun Lee ),( Doo Sun Sim ),( Young Joon Hong ),( Youngkeun Ahn ),( Chong Jin Kim ),( Myeong Chan Cho ),( Young Jo Kim ) 대한내과학회 2014 The Korean Journal of Internal Medicine Vol.29 No.6

The Korea Acute Myocardial Infarction Registry (KAMIR) was the first nationwide registry data collection designed to track outcomes of patients with acute myocardial infarction (AMI). These studies ref lect the current therapeutic approaches and management for AMI in Korea. The results of KAMIR could help clinicians to predict the prognosis of their patients and identify better diagnostic and treatment tools to improve the quality of care. The KAMIR score was proposed to be a predictor of the prognosis of AMI patients. Triple antiplatelet therapy, consisting of aspirin, clopidogrel and cilostazol, was effective at preventing major adverse clinical outcomes. Drug-eluting stents were effective and safe in AMI patients with no increased risk of stent thrombosis. Statin therapy was effective in Korean AMI patients, including those with very low levels of low density cholesterol. The present review summarizes the 10-year scientific achievements of KAMIR from admission to outpatient care during long-term clinical follow-up.

Active Immunization Study of Colon Cancer Derived 1-8D Peptide in HHD Mice

Jung, Hun-Soon,Ahn, In-Sook,Do, Hyung-Ki,Lemonnier, Francois A.,Song, Kuk-Hyun,Do, Myoung-Sool The Korean Association of Immunobiologists 2005 Immune Network Vol.5 No.3

Background: 1-8D gene is a member of human 1-8 interferon inducible gene family and was shown to be overexpressed in fresh colon cancer tissues. Three peptides 1-6, 3-5 and 3-7 derived from human 1-8D gene were shown to have immunogenicity against colon cancer. Methods: To study tumor immunotherapy, of three peptides we established an active immunization model using HHD mice. $D^{b-/-}{\times}{\beta}2$ microglobulin $({\beta}2m)$ null mice transgenic for a chimeric HLA-$A2.1/D^{b-}\;{\beta}2m$ single chain (HHD mice) were challenged with B16/HHD/1-8D tumor cells and were immunized with irradiated peptide-loaded RMA- S/HHD/B7.1 transfectants. In therapy model tumor growth was retarded in HHD mice that were injected with 3-5 peptide-loaded RMA-S/HHD/B7.1. In survival test vaccination with 1-8D-derived peptide protects HHD mice from tumor progression after tumor challenge. Results: These studies show that peptide 3-5 derived from 1-8D gene can be the most effective candidate for the vaccine of immunotherapy against colon cancer and highlight 1-8D gene as putative colon carcinoma associated antigens. Conclusion: We demonstrated that RMA-S/HHD/ B7.1 loaded with 1-8D peptides, especially 3-5, immunization generates potent antitumor immunity against tumor cells in HHD mice and designed active immunization as proper immunotherapeutic protocols.

Improvement of Reliability of a Flexible Photoluminescent Display Using Organic-Based Materials

Seung Hun Kim,Cheol Jang,Kuk Joo Kim,Sung-il Ahn,Kyung Cheol Choi IEEE 2010 IEEE transactions on electron devices Vol.57 No.12

<P>In this paper, a prototype flexible photoluminescent display using organic materials based on a low-temperature process, in which all steps are carried out at under 100 <SUP>°</SUP>C, is proposed and fabricated, and the results are compared with those of a conventional plasma display. The proposed flexible photoluminescent display showed a bending radius of about 5 cm, and microplasma was successfully generated in the panel with about 80 V of sustain margin, and similar characteristics compared with that of conventional plasma displays were observed. In addition, the reliability of the proposed display was evaluated over a long period of more than 30 h, which corresponds to a real operation time of 150 h, considering the acceleration factor, to assess its lifetime. Mechanisms for discharge gas contamination, which is a serious problem for reliability, were proposed, and various methods were suggested and applied to improve the reliability of the proposed display. From the continuous measurement of the luminance of test panels, it was found that the various methods suggested here yielded improved reliability of the proposed flexible photoluminescent displays. Thus, the proposed flexible photoluminescent display shows potential as a future flexible display.</P>

Hlicobacter pylori가 소화성 궤양 출혈에 미치는 영향

장병국,안성훈,허정욱,황재석,강영우,박승국 大韓消化器病學會 1999 大韓消化器病學會誌 Vol.34 No.3

산업연관분석을 이용한 중국 철강산업의 경제적 파급효과 실증분석 -생산유발효과, 수입유발효과, 부가가치유발효과를 중심으로-

안병국 ( Byung Kuk Ahn ),최영훈 ( Young Hun Choi ) 한중사회과학학회 2014 한중사회과학연구 Vol.12 No.1

Iron&Steel is key industry in China, which plays an important role in terms of GDP, tax revenue, and employment. Furthermore, because of it`s characteristic of grouping, steel industry`s contribution, at the province level, is more significant. China`s steel industry had kept it`s quantitative expansion since the foundation of China in 1949, and became world`s largest crude steel producing country in 1996. In 2012, China`s crude steel production stands at 708 million metric tons, accounting for 47% of world`s crude steel production. According to China`s 12th Five-Year Plan of Iron&Steel, which is backbone for steel industry policy of China, restructuring, rationalization of steel mill`s distribution, procurement of raw materials, and enhancement of globalization will be emphasized for sustainable growth of steel industry. In order for proving steel industry`s importance in China, this study, through input-output model, conducted empirical analysis on Chinese steel industry`s economic effect such as production induced effect, import induced effect, added value induced effect, forward linkage effect, and backward linkage effect etc.. And on the basis of literature survey, this study looked into Chinese steel industry`s historical development path and it`s outlook. Research results shows that steel industry ranked first among China`s 42 industry in terms of production induced effect. And China`s steel industry, with the help of government`s policy support, is expected to see both quantitative expansion and also qualitative improvement, with China maintaining it`s hegemony in global steel industry.

간이식 수술 후 재발된 B형 간염 환자 및 de novo 감염 환자에서 Adefovir의 치료 효과에 대한 예비 보고

김건국 ( Keon Kuk Kim ),김기훈 ( Ki Hun Kim ),황신 ( Shin Hwang ),안철수 ( Chul Soo Ahn ),문덕복 ( Deok Bog Moon ),하태용 ( Tae Yong Ha ),이승규 ( Sung Gyu Lee ) 대한소화기학회 2005 대한소화기학회지 Vol.45 No.3

Background/Aims: Anti-viral therapy using hepatitis B immune globulin and lamivudine could not prevent HBV recurrence after liver transplantation (LT) completely. Adefovir dipivoxil is a acyclic nucleotide phosphate analogue and known to have potent anti-

Two-Year Clinical Outcome after Carvedilol-Loaded Stent Implantation in Patients with Coronary Artery Disease

Kim, Hyun Kuk,Hong, Young Joon,Jeong, Myung Ho,Kim, Weon,Kim, Sung Soo,Ko, Jum Suk,Lee, Min Goo,Sim, Doo Sun,Park, Keun Ho,Yoon, Nam Sik,Yoon, Hyun Ju,Kim, Kye Hun,Park, Hyung Wook,Kim, Ju Han,Ahn, Yo The Korean Association of Internal Medicine 2011 The Korean Journal of Internal Medicine Vol.26 No.1

<P><B>Background/Aims</B></P><P>Carvedilol is an antioxidant that inhibits smooth muscle cell proliferation and migration. The aim of this study was to investigate the beneficial effects of carvedilol-loaded stents on 2-year clinical outcomes after stent implantation in patients with coronary artery disease.</P><P><B>Methods</B></P><P>We performed a prospective trial with male subjects to compare the safety and effects of carvedilol-loaded BiodivYsio® stents implanted into 20 patients with those of bare-metal BiodivYsio® stents implanted into 21 patients for de novo coronary lesions. The primary end point was the degree of neointimal hyperplasia, which was measured by intravascular ultrasound (IVUS) 6 months after the procedure; the secondary end point was major adverse cardiac events (MACE) at 2 years after implantation. All carvedilol and control stents were deployed successfully.</P><P><B>Results</B></P><P>A 2-year follow-up was completed for 19 patients (95%) in the carvedilol stent group and 20 patients (95%) in the control stent group. IVUS showed a trend toward a larger luminal area (6.86 ± 2.59 vs. 5.47 ± 1.52 mm<SUP>2</SUP>, <I>p</I> = 0.267), smaller neointimal area (1.34 ± 0.70 vs. 2.40 ± 1.73 mm<SUP>2</SUP>, <I>p</I> = 0.18), and reduced net decrease in luminal area (-0.78 ± 0.97 vs. -1.89 ± 1.78 mm<SUP>2</SUP>, <I>p</I> = 0.106) in the carvedilol stent group compared with the control stent group, respectively. There were no significant differences in the incidence of MACE (10.5 vs. 30.0%, respectively, <I>p</I> = 0.132) between the groups at 2 years after stent implantation. Stent thrombosis did not occur in either group after 2 years.</P><P><B>Conclusions</B></P><P>The carvedilol-loaded stents tended to inhibit neointimal hyperplasia without the occurrence of cardiac death, myocardial infarction, or stent thrombosis at 2-year follow-up.</P>

Investigation of biochemical property changes in activation-induced CD 8 + T cell apoptosis using Raman spectroscopy

Lee, Young Ju,Ahn, Hyung Joon,Lee, Gi-Ja,Jung, Gyeong Bok,Lee, Gihyun,Kim, Dohyun,Shin, Jae-Ho,Jin, Kyung-Hyun,Park, Hun-Kuk SPIE - International Society for Optical Engineeri 2015 Journal of biomedical optics Vol.20 No.7

<P>The study was to investigate the changes in biochemical properties of activated mature CD8+ T cells related to apoptosis at a molecular level. We confirmed the activation and apoptosis of CD8+ T cells by fluorescence-activated cell sorting and atomic force microscopy and then performed Raman spectral measurements on activated mature CD8+T cells and cellular deoxyribose nucleic acid (DNA). In the activated mature CD8+ T cells, there were increases in protein spectra at 1002 and 1234 cm(-1). In particular, to assess the apoptosis-related DNA spectral signatures, we investigated the spectra of the cellular DNA isolated from resting and activated mature CD8+ T cells. Raman spectra at 765 to 786 cm(-1) and 1053 to 1087 cm(-1) were decreased in activated mature DNA. In addition, we analyzed Raman spectrum using the multivariate statistical method including principal component analysis. Raman spectra of activated mature DNA are especially well-discriminated from those of resting DNA. Our findings regarding the biochemical and structural changes associated with apoptosis in activated mature T cells and cellular DNA according to Raman spectroscopy provide important insights into allospecific immune responses generated after organ transplantation, and may be useful for therapeutic manipulation of the immune response. (C) The Authors. Published by SPIE</P>

Helicobacter pylori가 소화성 궤양 출혈에 미치는 영향

강영우,안성훈,박승국,황재석,허정욱,장병국 대한소화기학회 1999 대한소화기학회지 Vol.34 No.3

Background/Aims: Helicobacter pylori (H. pylori) infection is deeply involved in pathogenesis of peptic ulcer. However, the role of H. pylori infection on the peptic ulcer bleeding is not established. We investigated the effect of H. pylori infection on ulcer bleeding by comparision of the incidence of H. pylori infection in patients with bleeding ulcer or non bleeding ulcer. Methods: We surveyed 101 patients who were diagnosed as bleeding and non bleeding peptic ulcer by gastroscopy from September, 1997 to June, 1998. We obtained biopsy specimen within 5 cm from pylorus by jumbo biopsy forcep and performed CLO test and Cresyl-Violet stain. Results: The positive rate of H. pylori infection in the patients with bleeding gastric ulcer was 55% (11 of 20), which was significantly lower than that of patients with non bleeding gastric ulcer, 84% (27 of 32)(p$lt;0.05). The positive rate of H. pylori infection in patients with bleeding duodenal ulcer was 69% (11 of 16), which was not significantly lower than that of patients with non bleeding duodenal ulcer, 81% (27 of 33). Conclusions: Our results suggested that H. pylori infection did not have any effect on bleeding in patients with peptic ulcer, especially gastric ulcer.