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.

Robust PEGylated hyaluronic acid nanoparticles as the carrier of doxorubicin: Mineralization and its effect on tumor targetability in vivo

Han, H.S.,Lee, J.,Kim, H.R.,Chae, S.Y.,Kim, M.,Saravanakumar, G.,Yoon, H.Y.,You, D.G.,Ko, H.,Kim, K.,Kwon, I.C.,Park, J.C.,Park, J.H. Elsevier Science Publishers 2013 Journal of controlled release Vol.168 No.2

The in vivo stability and tumor targetability of self-assembled polymeric nanoparticles are crucial for effective drug delivery. In this study, to develop biostable nanoparticles with high tumor targetability, poly(ethylene glycol)-conjugated hyaluronic acid nanoparticles (PEG-HANPs) were mineralized through controlled deposition of inorganic calcium and phosphate ions on the nanoparticular shell via a sequential addition method. The resulting nanoparticles (M-PEG-HANPs) had a smaller size (153.7+/-4.5nm) than bare PEG-HANPs (265.1+/-9.5nm), implying that mineralization allows the formation of compact nanoparticles. Interestingly, when the mineralized nanoparticles were exposed to acidic buffer conditions (<pH6.5), their sizes increased rapidly due to dissolution of the inorganic minerals. Doxorubicin (DOX), chosen as the model anticancer drug, was effectively encapsulated into the bare and mineralized nanoparticles. For bare PEG-HANPs, DOX was released in a sustained manner and its release rate was not dependent on the pH of the solution. On the other hand, DOX release from M-PEG-HANPs was pH-dependent: i.e. DOX was slowly released from nanoparticles under physiological condition (pH7.4), whereas its release rates were much higher at mildly acidic environments (<pH6.5). From in vivo biodistribution study, it was found that M-PEG-HANPs could reach the tumor site more effectively than bare PEG-HANPs. The antitumor efficacy of DOX-loaded nanoparticles was evaluated after systemic administration into the tumor-bearing mice. Of the samples tested, the most effective antitumor efficacy was observed for DOX-loaded M-PEG-HANPs. Overall, these results suggest that M-PEG-HANPs could be a promising carrier for an anticancer drug.

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.

Phase II study and biomarker analysis of cetuximab combined with modified FOLFOX6 in advanced gastric cancer

Han, S-W,Oh, D-Y,Im, S-A,Park, S R,Lee, K-W,Song, H S,Lee, N-S,Lee, K H,Choi, I S,Lee, M H,Kim, M A,Kim, W H,Bang, Y-J,Kim, T-Y Nature Publishing Group 2009 The British journal of cancer Vol.100 No.2

<P>This prospective study was conducted with the Korean Cancer Study Group to evaluate the efficacy and safety of cetuximab combined with modified FOLFOX6 (mFOLFOX6) as first-line treatment in recurrent or metastatic gastric cancer and to identify potential predictive biomarkers. Patients received cetuximab 400 mg m<SUP>−2</SUP> at week 1 and 250 mg m<SUP>−2</SUP> weekly thereafter until disease progression. Oxaliplatin (100 mg m<SUP>−2</SUP>) and leucovorin (100 mg m<SUP>−2</SUP>) were administered as a 2-h infusion followed by a 46-h continuous infusion of 5-fluorouracil (2400 mg m<SUP>−2</SUP>) every 2 weeks for a maximum of 12 cycles. Biomarkers potentially associated with efficacy were analysed. Among 38 evaluable patients, confirmed response rate (RR) was 50.0% (95% CI 34.1–65.9). Median time-to-progression (TTP) was 5.5 months (95% CI 4.5–6.5) and overall survival (OS) 9.9 months. Eleven patients having tumour EGFR expression by immunohistochemistry with low serum EGF and TGF-<I>α</I> levels showed a 100% RR compared to 37.0% in the remaining 27 patients (<I>P</I><0.001). Moreover, ligand level increased when disease progressed in seven out of eight patients with EGFR expression and low baseline ligand level. No patient exhibited EGFR amplification or K-ras mutations. Gastric cancer patients with EGFR expression and low ligand levels had better outcomes with cetuximab/mFOLFOX6 treatment.</P>

Metabolizable Energy Values of Some Poultry Feeds Determined by Various Methods and Their Estimation Using Metabolizability of the Dry Matter

Han, I. K.,Hochstetler, H.W.,Scott, M.L. The Korean Society of Poultry Science 1976 韓國家禽學會誌 Vol.3 No.1

Metabolizable energy (M.E.) values of 12 U.S. feedstuffs and 10 Korean feed ingredients for poultry were determined both by the total collection method and by the chromic oxide indicator method. It was found that M.E. values of most poultry feedstuffs can be measured accurately by either method. Limitation of feed intake to almost maintenance level(approximately 60% of ad libitum) did not increase or decrease the M.E. value of the feeds. An attempt was made to establish a prediction equation to estimate the M.E. values based on the apparent metabolizability of dry matter (D.M.) in the feedstuffs. The results indicated that linear relationships do exist between D. M. metabolizability and M.E. values of carbohydrate-rich feedstuffs (grains and their by-products) or protein-rich feed ingredients (oil seed meals and animal protein feeds) or lipid-rich feeds (fats and oils) as follows: The prediction equation for carbohydrate-rich feedstuffs was Y = 0.0947x - 3.498 ($r^2\;=\;0.99$, Sy.x = 0.015); for protein-rich feed ingredients. it was Y = 0.1234x - 4.898 ($r^2\;=\;0.99$, Sy.x = 0.027); and for lipid-rich feedstuffs it was Y = 0.0844x + 0.774 ($r^2\;=\;0.99$, Sy.x = 0.032). where x = metabolizability of dry matter of feeds in %, and Y=metabolizable energy values in kcal./g. The errors attached to these estimations were relatively small. Thus these prediction equations may be very useful for estimation of the M.E. values from D.M. apparent metaboiizability of feeds, especially in areas of the world where calorimetry is not possible.

Microstructure-dependent fatigue behavior of aged Cu-6Ni-1.5Si alloy with discontinuous/cellular precipitates

Goto, M.,Yamamoto, T.,Han, S.Z.,Lim, S.H.,Kim, S.,Iwamura, T.,Kitamura, J.,Ahn, J.-H.,Yakushiji, T.,Lee, J. Elsevier 2019 Materials science & engineering. properties, micro Vol.747 No.-

<P><B>Abstract</B></P> <P>The effect of microstructure on the fatigue strength of age-hardened Cu–6Ni–1.5Si alloy was investigated in this study. The aging was conducted at 500 °C for 0.5 h for the precipitation of disk-shaped δ-Ni<SUB>2</SUB>Si precipitates (continuous precipitates) and 3 h for the discontinuous precipitation of fiber-shaped, stable δ-Ni<SUB>2</SUB>Si precipitates to strengthen the Cu matrix. The tensile strength of 0.5 h-aged specimens was about 1.3 times greater than that of the 3 h-aged counterparts, but with inferior electrical conductivity. Despite the considerable difference in tensile strength, no notable difference in fatigue strength was observed between 0.5 h- and 3 h-aged specimens. The 3 h-aged specimens had superior electrical conductivity without sacrificing fatigue strength of the 0.5 h-aged specimens. The physical background of high-cycle fatigue strength in Cu–6Ni–1.5Si alloys with continuous precipitates and discontinuous precipitates is discussed considering the microstructure-sensitive behavior of fatigue cracks.</P>

Effects of catalpalactone on dopamine biosynthesis and L-DOPA-induced cytotoxicity in PC12 cells

Huang, H.S.,Han, X.H.,Hwang, B.Y.,Park, J.I.,Yoo, S.K.,Lee, H.J.,Lim, S.C.,Lee, M.K. Elsevier Science B.V 2008 Environmental toxicology and pharmacology Vol.26 No.1

The effects of catalpalactone on dopamine biosynthesis and L-DOPA-induced cytotoxicity in PC12 cells were investigated. Catalpalactone at 5-30μM decreased intracellular dopamine content with the IC<SUB>50</SUB> value of 22.1μM. Catalpalactone at 5-20μM, but not 30μM, did not alter cell viability. Catalpalactone at 20μM inhibited tyrosine hydroxylase (TH) and aromatic-l-amino acid decarboxylase (AADC) activities. Catalpalactone also decreased cyclic AMP levels and inhibited TH phosphorylation. In addition, catalpalactone at 20μM reduced the increases in dopamine levels induced by L-DOPA (20-50μM). Catalpalactone (5-30μM) associated with L-DOPA (50-100μM) enhanced L-DOPA-induced cytotoxicity at 48h, which was prevented by N-acetyl-l-cysteine. These results suggest that catalpalactone inhibited dopamine biosynthesis by reducing TH and AADC activities and enhanced L-DOPA-induced cytotoxiciy in PC12 cells.

Photocatalytic H2 production on trititanate nanotubes coupled with CdS and platinum nanoparticles under visible light: revisiting H2 production and material durability

Park, H.,Ou, H. H.,Kim, M.,Kang, U.,Han, D.,Hoffmann, M. Royal Society of Chemistry 2017 Faraday discussions Vol.198 No.-

<P>The photocatalytic production of molecular hydrogen (H-2) on ternary composites of Pt, CdS, and sodium trititanate nanotubes (NaxH2-xTi3O7, TNTs) is examined in an aqueous 2-propanol (IPA) solution (typically 5 vol%) at a circum-neutral pH under visible light (lambda > 420 nm). The H-2 production rates are dependent on the Pt-loading level, and the optimum production rate in the Pt/CdS/TNTs is approximately six times higher than that in Pt/CdS/TiO2. A D2O solution containing 5 vol% IPA leads only to the production of D-2 molecules, whereas increasing the IPA amount to 30 vol% leads to the production of DH molecules. This indicates that the Pt/CdS/TNTs composites enable H-2 production via true water splitting under our typical experimental conditions. X-ray photoelectron spectroscopy (XPS) analyses of the as-synthesized Pt/CdS/TNTs and those used for 6 and 12 h show that metallic Pt on the CdS/TNTs is less susceptible to oxidation than Pt on CdS/TiO2. In addition, photocorrosion of CdS (i.e., sulfate formation) is significantly inhibited during the photocatalytic H-2 production reactions in the Pt/CdS/TNTs because of the efficient charge transfer via the TNTs framework. The Pt/CdS/TNTs samples are thermally more stable than Pt/CdS/TiO2 and CdS/TNTs, effectively inhibiting the formation of CdO during the thermal synthesis. Detailed surface characterizations of the as-synthesized ternary composites are performed using Xray diffraction, transmission electron microscopy, energy dispersive spectroscopy, and XPS.</P>

Characteristics of atmospheric speciated mercury concentrations (TGM, Hg(II) and Hg(p)) in Seoul, Korea

Kim, S.H.,Han, Y.J.,Holsen, T.M.,Yi, S.M. Pergamon Press ; Elsevier [distribution] 2009 Atmospheric environment Vol.43 No.20

Ambient speciated mercury concentrations including total gaseous mercury (TGM), gaseous divalent mercury (Hg(II)), and particulate mercury (Hg(p)) were measured on the roof of the Graduate School of Public Health building in Seoul, Korea from February 2005 to February 2006. The average concentrations were 3.22 +/- 2.10 ng m<SUP>-3</SUP>, 27.2 +/- 19.3 pg m<SUP>-3</SUP>, and 23.9 +/- 19.6 pg m<SUP>-3</SUP> for TGM, Hg(II), and Hg(p), respectively. Hg(II) and Hg(p) concentrations were higher during the daytime than during the nighttime, probably because of high photochemical activity. Hg<SUP>0</SUP> concentrations were not significantly correlated with ozone however a positive correlation between ozone and Hg(II) was found during periods of high humidity. Eighteen days were characterized as pollution events with 24 h average PM<SUB>2.5</SUB> concentrations >65 μg m<SUP>-3</SUP>. The average concentrations of TGM and Hg(p) during these events were 1.4-2 times higher than those during non-pollution events. In order to identify the contribution of long-range transported mercury to the enhanced mercury concentrations in Korea, an episode was defined as a period with hourly average TGM and CO concentrations higher than the monthly average TGM and CO concentrations and with significant enhancement of both TGM and CO concentrations for at least 10 h. A total of 70 episodes were identified during the sampling period: 36 local episodes and 34 long-range transport episodes. The mean ΔTGM/ΔCO slope for all episodes was 0.0063 ng m<SUP>-3</SUP> ppbv<SUP>-1</SUP> which agreed well with the slope (0.0036-0.0074 ng m<SUP>-3</SUP> ppbv<SUP>-1</SUP>) found in previous studies that identified long-range transport of TGM from China. The mean slope during non-events was 0.0011 ng m<SUP>-3</SUP> ppbv<SUP>-1</SUP>. Back-trajectory analysis showed that during episodes, air parcels arrived mostly from the major industrial areas in China (n = 25, 73%), followed by Japan (n = 4, 12%), Yellow Sea (n = 3, 9%), and Russia (n = 2, 6%).

Comparison of 90‐day case‐fatality after ischemic stroke between two different stroke outcome registries using propensity score matching analysis

Yu, K‐,H.,Hong, K‐,S.,Lee, B‐,C.,Oh, M‐,S.,Cho, Y‐,J.,Koo, J‐,S.,Park, J‐,M.,Bae, H‐,J.,Han, M‐,K.,Ju, Y‐,S.,Kang, D‐,W.,Appelros, P. Blackwell Publishing Ltd 2011 Acta neurologica Scandinavica Vol.123 No.5

<P>Yu K‐H, Hong K‐S, Lee B‐C, Oh M‐S, Cho Y‐J, Koo J‐S, Park J‐M, Bae H‐J, Han M‐K, Ju Y‐S, Kang D‐W, Appelros P, Norrving B, Terent A. Comparison of 90‐day case‐fatality after ischemic stroke between two different stroke outcome registries using propensity score matching analysis. 
Acta Neurol Scand: 2011: 123: 325–331. 
© 2010 John Wiley & Sons A/S.</P><P><B>Background – </B> It has not been clarified whether the disparity in ischemic stroke outcome between populations is caused by ethnic and geographic differences or by variations in case mix. Propensity score matching (PSM) analysis can overcome some analytical problems but is rarely used in stroke outcome research. This study was to compare the ischemic stroke case‐fatality between two PSM cohorts of Sweden and Korea.</P><P><B>Methods – </B> Prognostic variables related to baseline characteristics and stroke care were included in our PSM model. Then, we selected 7675 Swedish and 1220 Korean patients with ischemic stroke from each stroke registers and performed one‐to‐one matching based on propensity scores of each patient.</P><P><B>Results – </B> After PSM, all measured variables were well balanced in 1163 matched subjects, and the 90‐day case‐fatality was identical 6.2% (HR 0.997, 95%CI 0.905–1.099) in Sweden and Korea.</P><P><B>Conclusions – </B> No difference is found in the 90‐day case‐fatality in propensity score‐matched Swedish and Korean patients with ischemic stroke.</P>