Effect of low concentrations of hydrogen peroxide on the contractile responses of rat detrusor smooth muscle strips

Han, J.H.,Lee, M.Y.,Lee, S.Y.,Chang, I.H.,Kim, H.J.,Kim, W.,Myung, S.C. North-Holland ; Elsevier Science Ltd 2010 european journal of pharmacology Vol.638 No.1

This study was designed to determine how the contractility of rat detrusor smooth muscle strips changes in the presence of low concentrations of hydrogen peroxide (H<SUB>2</SUB><SUB>2</SUB>. The strips were dissected from the base of Sprague-Dawley rat bladders and their contractile responses to a cumulative increase in H<SUB>2</SUB><SUB>2</SUB>concentration (3x10<SUP>-6</SUP>3x10<SUP>-2</SUP>%) were measured. How the duration of exposure to the fixed concentration of 3x10<SUP>-4</SUP>% H<SUB>2</SUB><SUB>2</SUB>affected contractility was also examined. Moreover, the effect of 3x10<SUP>-4</SUP>% H<SUB>2</SUB><SUB>2</SUB>pretreatment on the response to cumulative increases in the concentrations of phenylephrine or acetylcholine (10<SUP>-8</SUP>10<SUP>-4</SUP>) was assessed. To elucidate the mechanism by which H<SUB>2</SUB><SUB>2</SUB>induced contraction, we examined the effect of pretreatment with 10nM Y-27632, 10μM indomethacin, 10μM SQ29548, 10μM verapamil, 10μM vitamin E, or 1μM Bay-K 8644 on the contractile responses generated by cumulatively increasing the concentration of H<SUB>2</SUB><SUB>2</SUB> H<SUB>2</SUB><SUB>2</SUB>induced contractile responses in Ca<SUP>2+</SUP>free physiological solution were also examined. Low concentrations of H<SUB>2</SUB><SUB>2</SUB>increased the contractile responses of the strips in a dose-dependent manner but increasing treatment duration decreased these responses. H<SUB>2</SUB><SUB>2</SUB>pretreatment significantly augmented the contraction induced by phenylephrine (P<0.05) but had no effect on the response to acetylcholine. Pretreatment with Y-27632, indomethacin, vitamin E, verapamil, and Bay-K 8644 significantly inhibited the H<SUB>2</SUB><SUB>2</SUB>induced contraction (P<0.05). SQ 29548-pretreatment had no effect. H<SUB>2</SUB><SUB>2</SUB>could not increase the contractile responses in Ca<SUP>2+</SUP>free physiological solution. Thus, low concentrations of H<SUB>2</SUB><SUB>2</SUB>may directly affect detrusor smooth muscles and thereby induce detrusor overactivity.

A multi-virus detectable microfluidic electrochemical immunosensor for simultaneous detection of H1N1, H5N1, and H7N9 virus using ZnO nanorods for sensitivity enhancement

Han, J.H.,Lee, D.,Chew, C.H.C.,Kim, T.,Pak, J.J. Elsevier Sequoia 2016 Sensors and actuators. B Chemical Vol.228 No.-

This paper describes a multi-detectable and nano-flow immunosensor based on ZnO nanorods (NRs) grown on the inner surface of PDMS sensor region for sensing H1N1, H5N1, and H7N9 influenza viruses simultaneously using electrochemical method. Nanostructured ZnO NRs with a high isoelectric point (IEP ~9.5) tend to interact electrostatically with proteins with lower IEP such as H1N1, H5N1, and H7N9 antibodies. ZnO NRs were hydrothermally grown on the upper inner surface of the nano-flow PDMS sensor region. The forementioned three influenza viruses were successfully detected from three separate sensing regions by measuring the oxidation current of 3,3',5,5'-tetramethylbenzidine (TMB) by horseradish peroxidase (HRP) conjugated on capture antibody of those influenza viruses when proper potential was applied. The proposed immunosensors were evaluated using 1pg/ml, 10pg/ml, 100pg/ml, 1ng/ml, and 10ng/ml of H1N1, H5N1, and H7N9 antigens by amperometry. These immunosensors showed high selectivity toward H1N1, H5N1, and H7N9, which was successfully confirmed by distinguishing the target virus individually from a mixture of three virus antigens. A low limit of detection was demonstrated by detecting as low as 1pg/ml of each virus and it is believed that this was possible by enhancing the sensitivity with the ZnO NRs grown on the PDMS surface in the sensing region. The steady-state oxidation current output linearly increased with respect to the logarithm of the H1N1, H5N1, and H7N9 virus concentrations in the range of 1-10ng/ml.

분만 후 모돈의 행동적 회복과 포유자돈의 행동적 발달

전중환,김동주,한지훈,연성찬,장홍희 한국동물자원과학회 2003 한국축산학회지 Vol.45 No.6

We investigated postpartum behaviors of sows and their litters. The aim of this study was to determine the behavioral recovery of sows and behavioral development of their piglets postpartum. Five multiparous sows(Landrace × Yorkshire) and their litters were studied over a period of 5 days postpartum. The litter size varied from 8 to 13 with a mean of 11.2 piglets. The behaviors of sows and their piglets were recorded using five CCD cameras, a multiplexer and a time lapsed VCR. The videotapes were scanned every 2 min to obtain an instantaneous behavioral sample. In the behaviors of sows, ?Lying ventrally? increased from 1h postpartum to 26g postpartum, then decreased gradually, and stabilized after 80h postpartum. ?Lying ventrally? decreased from 1h postpartum to 26h postpartum and stabilized after 80h postpartum. ?Standing, drinking and feeding? increased from 1h postpartum to 23h postpartum, then decreased gradually, and increased again from 60h postpartum. ?Sitting? increased from 1h postpartum to 46h postpartum and then decreased. In the behaviors of piglets, ?Lying? increased rapidly from 1h postpartum to 45h postpartum, and then was maintained at an almost constant level. ?Massaging and Suckling? decreased rapidly from 1h postpartum to 36g postpartum, and then was maintained at an almost constant level. ?Walking? increased from 1h postpartum to 21h postpartum, then decreased gradually. These results suggest that the behavioral recovery of the sow is almost completed at 80h postpartum and that the behavioral development of the piglet is almost completed at 45h postpartum.

Tat-PRAS40 prevent hippocampal HT-22 cell death and oxidative stress induced animal brain ischemic insults

Shin, M.J.,Kim, D.W.,Jo, H.S.,Cho, S.B.,Park, J.H.,Lee, C.H.,Yeo, E.J.,Choi, Y.J.,Kim, J.A.,Hwang, J.S.,Sohn, E.J.,Jeong, J.H.,Kim, D.S.,Kwon, H.Y.,Cho, Y.J.,Lee, K.,Han, K.H.,Park, J.,Eum, W.S.,Choi, Pergamon ; Elsevier Science Ltd 2016 FREE RADICAL BIOLOGY AND MEDICINE Vol.97 No.-

Proline rich Akt substrate (PRAS40) is a component of mammalian target of rapamycin complex 1 (mTORC1) and is known to play an important role against reactive oxygen species-induced cell death. However, the precise function of PRAS40 in ischemia remains unclear. Thus, we investigated whether Tat-PRAS40, a cell-permeable fusion protein, has a protective function against oxidative stress-induced hippocampal neuronal (HT-22) cell death in an animal model of ischemia. We showed that Tat-PRAS40 transduced into HT-22 cells, and significantly protected against cell death by reducing the levels of H<SUB>2</SUB>O<SUB>2</SUB> and derived reactive species, and DNA fragmentation as well as via the regulation of Bcl-2, Bax, and caspase 3 expression levels in H<SUB>2</SUB>O<SUB>2</SUB> treated cells. Also, we showed that transduced Tat-PARS40 protein markedly increased phosphorylated RRAS40 expression levels and 14-3-3σ complex via the Akt signaling pathway. In an animal ischemia model, Tat-PRAS40 effectively transduced into the hippocampus in animal brain and significantly protected against neuronal cell death in the CA1 region. We showed that Tat-PRAS40 protein effectively transduced into hippocampal neuronal cells and markedly protected against neuronal cell damage. Therefore, we suggest that Tat-PRAS40 protein may be used as a therapeutic protein for ischemia and oxidative stress-induced brain disorders.

The mechanism of hydrogen embrittlement in intercritically annealed medium Mn TRIP steel

Han, J.,Nam, J.H.,Lee, Y.K. Elsevier Science 2016 Acta materialia Vol.113 No.-

<P>The objective of this study was to investigate the mechanisms of hydrogen embrittlement (HE) in intercritically annealed medium Mn steel. For this purpose, both hot-rolled and cold-rolled Fe-7Mn-0.1C-0.5Si (wt.%) steels were annealed at 640 degrees C for 30 min. The annealed specimens had a dual-phase microstructure of retained austenite (gamma R) and ferrite (alpha) with different morphologies; a lath shape for the hot-rolled and annealed (HRA) specimen and a globular shape for the cold-rolled and annealed (CRA) specimen. Although the difference in microstructural morphology did not influence the H permeation, it significantly affected the HE behavior. The H-charged HRA (HRA(H)) specimen was fractured by inter granular cracking occurring along the boundaries of prior gamma grains by the H-enhanced decohesion (HEDE) mechanism. The intergranular cracking leaved both flat and rugged facets, which appeared at the prior gamma grain boundaries without and with gamma R, respectively. The H-charged CRA (CRA(H)) specimen was fractured to leave both dimples filled with grains and empty dimples at the fractured surface. The dimples filled with grains were generated by intergranular cracking occurring along the boundaries of gamma R grains by the HEDE mechanism. The empty dimples were made by intragranular cracking occurring inside the alpha grains by the H-enhanced local plasticity (HELP) mechanism. The CRA(H) specimen exhibited a smaller elongation loss than the HRA(H) specimen because cracks were propagated by frequently changing their direction along the boundaries of nano-sized gamma R grains or into alpha grains. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.</P>

Fucoidan protects mesenchymal stem cells against oxidative stress and enhances vascular regeneration in a murine hindlimb ischemia model

Han, Y.s.,Lee, J.H.,Jung, J.S.,Noh, H.,Baek, M.J.,Ryu, J.M.,Yoon, Y.M.,Han, H.J.,Lee, S.H. Elsevier/North-Holland Biomedical Press 2015 INTERNATIONAL JOURNAL OF CARDIOLOGY Vol.198 No.-

Background: Mesenchymal stem cells (MSCs) have the potential to differentiate into multiple cell lineages. Given this potential for tissue regeneration, MSC-based therapeutic applications have been considered in recent years. However, ischemia-induced apoptosis has been reported to be one of the main causes of MSC death following transplantation. The primary objective of this study was to determine whether a natural antioxidant, fucoidan, could protect MSCs from ischemia-induced apoptosis in vitro and in vivo. Furthermore, we investigated the mechanism of action of fucoidan's anti-ischemic effect in MSCs. Methods and result: Pre-treatment with fucoidan (10μg/mL) suppressed the increase in H<SUB>2</SUB>O<SUB>2</SUB>-induced reactive oxygen species (ROS) levels and drastically reduced apoptotic cell death in MSCs. Fucoidan inhibited the activation of the pro-apoptotic proteins p38-mitogen-activated protein kinase (MAPK), Jun N-terminal kinase (JNK), and caspase-3, and augmented the expression of the anti-apoptosis protein cellular inhibitor of apoptosis (cIAP). Moreover, fucoidan significantly increased manganese superoxide dismutase (MnSOD) expression and decreased cellular ROS levels via the Akt pathway, resulting in enhanced cell survival. In a murine hindlimb ischemia model, transplanted fucoidan-treated MSCs showed significantly enhanced cell survival and proliferation in ischemic tissues. Functional recovery and limb salvage also remarkably improved in mice injected with fucoidan-stimulated MSCs compared with mice injected with non-stimulated MSCs. Conclusion: Taken together, these results show that fucoidan protects MSCs from ischemia-induced cell death by modulation of apoptosis-associated proteins and cellular ROS levels through regulation of the MnSOD and Akt pathways, suggesting that fucoidan could be powerful therapeutic adjuvant for MSC-based therapy in ischemic diseases.

한우 어미소와 송아지의 행동 특성

한지훈,김동주,전중환,장홍희,구자민,김은정,이효종,연성찬 한국동물자원과학회 2004 한국축산학회지 Vol.46 No.1

This study was performed to investigate the behavioral characteristics of Hanwoo(Bos taurus coreanae) cows and their calves. Four cows and their calves were placed in pens. The behaviors of each cow and calf were recorded using a time lapse VCR from 07:00 h to 18:00 h for 6 days and were analyzed using the scan point sampling method. The cow's behaviors in order of frequency were LD(lying down, 25%), ST(standing, 23%), EA(eating, 13%), LR(lying down rumination, 10%) and SR(standing rumination, 7%). The cows spent less than 3% of their time PG(pairwise grooming) and SF(sniffing). The calves mainly showed LD(52%), ST(28%), LF(lying flat, 4%), EA(3%) and WA(walking, 3%). The calves spent less than 2% of their time SF(sniffing) and SUK(sucking). The behavioral patterns of cows and calves at 07:00 h, 12:00 h and 18:00 h were different, especially in ST and LD.

Effects of the novel angiotensin II receptor type I antagonist, fimasartan on myocardial ischemia/reperfusion injury

Han, J.,Park, S.J.,Thu, V.T.,Lee, S.R.,Long, L.T.,Kim, H.K.,Kim, N.,Park, S.W.,Jeon, E.S.,Kim, E.J.,Yoon, C.H.,Cho, G.Y.,Choi, D.J. Elsevier/North-Holland Biomedical Press 2013 INTERNATIONAL JOURNAL OF CARDIOLOGY Vol.168 No.3

Background: The aim of this study was to investigate the cardioprotective effect of fimasartan, a newly developed angiotensin II receptor type I blocker (ARB), against myocardial ischemia/reperfusion (I/R) injury and to identify the mechanism by which it reduces mitochondrial damage. Methods: Fimasartan was administered intravenously to Sprague-Dawley rats (3mg/kg), cardiomyocytes (50μM), and H9c2 cells (50μM) before ischemia or hypoxia. Myocardial infarction (MI), echocardiograms, DNA fragmentation, terminal deoxynucleotidyl transferase-mediated dUTP in situ nick-end labeling, immunoblotting, oxygen consumption, confocal microscopic appearance, and L-type Ca<SUP>2+</SUP> current (I<SUB>Ca,L</SUB>) were then assessed. Results: Fimasartan pretreatment remarkably reduced the rate of MI and improved cardiac performance well after I/R (n=9/group). Fimasartan also reduced apoptotic cell death both in vivo and in hypoxia/reoxygenation (H/R)-treated H9c2 cells (n=5~8/group). H/R-induced mitochondrial O<SUB>2</SUB><SUP>-</SUP> production and collapse of membrane potential were markedly attenuated in fimasartan-treated cardiomyocytes (n=4~6/group). Additionally, mitochondrial Ca<SUP>2+</SUP> overload during reoxygenation was suppressed by fimasartan (n=4~6/group), and this was found to be possibly related to the inhibition of I<SUB>Ca,L</SUB> and mitochondrial Ca<SUP>2+</SUP> uniporter. Furthermore, fimasartan pretreatment increased phosphorylations of Akt and glycogen synthase kinase-3β (n=5~7/group), decreased pro-apoptotic p53 levels, and increased anti-apoptotic Bcl-2 levels (n=4) during reperfusion. Conclusions: Fimasartan preconditioning has the potential to modulate Bcl-2 and suppress I/R-induced Ca<SUP>2+</SUP> overload by inhibiting I<SUB>Ca,L</SUB> and MCU. These beneficial effects could prevent the mitochondrial dysfunction and apoptosis accompanied by I/R.

Diagnostic usefulness of a T cell-based assay for latent tuberculosis infection in kidney transplant candidates before transplantation

Kim, S.-H.,Lee, S.-O.,Park, I.-A.,Park, S.J.,Choi, S.-H.,Kim, Y.S.,Woo, J.H.,Park, S.-K.,Park, J.S.,Kim, S.C.,Han, D.J. Blackwell Publishing Inc 2010 Transplant infectious disease Vol.12 No.2

<P>S.-H. Kim, S.-O. Lee, I.-A. Park, S.J. Park, S.-H. Choi, Y.S. Kim, J.H. Woo, S.-K. Park, J.S. Park, S.C. Kim, D.J. Han. Diagnostic usefulness of a T cell-based assay for latent tuberculosis infection in kidney transplant candidates before transplantation.Transpl Infect Dis 2010: <B>12:</B> 113–119. All rights reserved</P><P>Background</P><P>The presence of latent tuberculosis (TB) infection (LTBI) should be evaluated before kidney transplantation. Although a new T cell-based assay for diagnosing LTBI gave promising results, this assay has not yet been compared with the tuberculin skin test (TST) for diagnosing LTBI in renal transplant candidates before transplantation.</P><P>Patients and methods</P><P>All adult patients admitted to a single institute for renal transplantation over a 1-year period were prospectively enrolled. A clinically predictive risk of LTBI was defined as: (i) recent close contact with a person with pulmonary TB; (ii) abnormal chest radiography; (iii) a history of untreated or inadequately treated TB; or (iv) a new infection (i.e., a recent conversion of TST).</P><P>Results</P><P>Of 209 renal recipients, 47 (22%) had a positive TST≥5 mm, 21 (10%) had a positive TST≥10 mm, 65 (30%) had a positive T-SPOT.<I>TB</I> test, and 25 (12%) had an indeterminate T-SPOT.<I>TB</I> test. The induration size of TST was significantly associated with a high positivity rate on T-SPOT.<I>TB</I> (<I>P</I><0.001). Agreement between T-SPOT.<I>TB</I> test and TST≥10 mm was fair (<I>k</I>=0.24, 95% confidence interval 0.11–0.36). However, neither univariate nor multivariate analysis showed any association between the clinical risk for LTBI and positivity on T-SPOT.<I>TB</I> or TST.</P><P>Conclusion</P><P>T-SPOT.<I>TB</I> test was more frequently positive than TST in renal transplant candidates. However, further longitudinal studies are awaited to determine whether the ability of T-SPOT.<I>TB</I> assay to detect LTBI in renal transplant recipients can better predict the development of TB than can TST after transplantation.</P>

Tuning microcavities in thermally rearranged polymer membranes for CO₂ capture

Han, S. H.,Kwon, H. J.,Kim, K. Y.,Seong, J. G.,Park, C. H.,Kim, S.,Doherty, C. M.,Thornton, A. W.,Hill, A. J.,Lozano, Á,. E.,Berchtold, K. A.,Lee, Y. M. The Royal Society of Chemistry 2012 Physical Chemistry Chemical Physics Vol.14 No.13

<P>Microporous materials have a great importance in catalysis, delivery, storage and separation in terms of their performance and efficiency. Most microporous materials are comprised of inorganic frameworks, while thermally rearranged (TR) polymers are a microporous organic polymer which is tuned to optimize the cavity sizes and distribution for difficult separation applications. The sub-nano sized microcavities are controlled by <I>in situ</I> thermal treatment conditions which have been investigated by positron annihilation lifetime spectroscopy (PALS). The size and relative number of cavities increased from room temperature to 230 °C resulting in improvements in both permeabilities and selectivities for H<SUB>2</SUB>/CO<SUB>2</SUB> separation due to the significant increase of gas diffusion and decrease of CO<SUB>2</SUB> solubility. The highest performance of the well-tuned TR-polymer membrane was 206 Barrer for H<SUB>2</SUB> permeability and 6.2 of H<SUB>2</SUB>/CO<SUB>2</SUB> selectivity, exceeding the polymeric upper bound for gas separation membranes.</P> <P>Graphic Abstract</P><P>Thermally rearranged polybenzoxazoles with tuned cavities for hydrogen purification and carbon dioxide separation even at high temperature were developed to apply for a syn gas separation. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2cp23729f'> </P>