[show abstract][hide abstract] ABSTRACT: This study examined the effects of calcium (Ca) gluconate on collagen-induced DBA mouse rheumatoid arthritis (CIA). A single daily dose of 200, 100 or 50 mg/kg Ca gluconate was administered orally to male DBA/1J mice for 40 days after initial collagen immunization. To ascertain the effects administering the collagen booster, CIA-related features (including body weight, poly-arthritis, knee and paw thickness, and paw weight increase) were measured from histopathological changes in the spleen, left popliteal lymph node, third digit and the knee joint regions. CIA-related bone and cartilage damage improved significantly in the Ca gluconate- administered CIA mice. Additionally, myeloperoxidase (MPO) levels in the paw were reduced in Ca gluconate-treated CIA mice compared to CIA control groups. The level of malondialdehyde (MDA), an indicator of oxidative stress, decreased in a dosedependent manner in the Ca gluconate group. Finally, the production of IL-6 and TNF-α, involved in rheumatoid arthritis pathogenesis, were suppressed by treatment with Ca gluconate. Taken together, these results suggest that Ca gluconate is a promising candidate anti-rheumatoid arthritis agent, exerting anti-inflammatory, anti-oxidative and immunomodulatory effects in CIA mice.
Biomolecules and Therapeutics 07/2013; 21(4):290-8. · 0.79 Impact Factor
[show abstract][hide abstract] ABSTRACT: The objective of this study is to detect the effect of beta-glucan derived from Aureobasidium pullulans SM-2001, a UV induced mutant of A. pullulans on the ovalbumin (OVA) induced allergic asthma. The test articles were orally administered to OVA-inducing asthmatic mice 4 days after sensitization for 13 days at 31.25, 62.5 or 125 mg/kg levels. Three days after the OVA sensitization, ten mice were selected per group based on body weight and were sacrificed three days after the OVA aerosol challenge. The changes on the body weight, lung weight, total leukocytes in peripheral blood and total cells in bronchoalveolar lavage fluid (BALF) were observed with changes on the lung histopathology and histomorphometry. The results were compared with dexamethasone (DEXA) 3 mg/kg intraperitoneally treated mice. The results showed increases of body weight after the OVA aerosol challenge, lung weight, total leukocytes and eosinophils in peripheral blood, total cell numbers, neutrophil and eosinophils in BALF were detected in the OVA control compared to sham control (non-OVA). However, these changes from asthmatic responses were significantly or dose-dependently decreased in the beta-glucan-dosing groups compared to those of the OVA control. Therefore, it is concluded that beta-glucan has favorable effects on asthmatic response induced by OVA. It was found that beta-glucan 125 mg/kg showed similar or slightly lower efficacy compared with DEXA 3 mg/kg.
Archives of Pharmacal Research 06/2012; 35(6):1073-81. · 1.54 Impact Factor
[show abstract][hide abstract] ABSTRACT: BACKGROUND: Kidneys previously exposed to ischemia and reperfusion (I/R), pre-conditioned by I/R, are less susceptible to subsequent I/R injury. Here, we investigated the role for protein kinase B (Akt) survival signaling pathways including anti-apoptosis pathways in the reduced susceptibility of I/R-pre-conditioned kidneys.METHODS: Mice were exposed to either a single I/R pre-conditioning event (SIRPC, 30 min of bilateral renal ischemia followed by 8 days of reperfusion) or sham-operation (non-SIRPC) and then subjected to either 30 min of bilateral renal ischemia or sham-operation (sham). Some of the mice received intra-peritoneal administrations of wortmannin, which is an inhibitor of phosphatidylinositol-3 kinase, PI3K.RESULTS: Thirty minutes of bilateral renal ischemia in non-SIRPC mice induced a dramatic increase in plasma creatinine (PCr) levels, but this was not observed in the SIRPC mouse. Consistent with the PCr results, tubular damage and apoptotic tubular cell death were more severe in the non-SIRPC mouse kidney than in the SIRPC mice. SIRPC increased the levels of phosphorylated-Akt and -Bad expression as well as the ratio of Bcl-2 to Bax expression in the kidney. I/R resulted in greater increases of phosphorylated-Akt and -Bad, Bcl-xL and Bcl-2, but a lower level of increase of Bax, in the SIRPC mouse kidneys than those in the non-SIRPC-mouse kidneys. Treatment with wortmannin during the SIRPC period inhibited SIRPC-induced increase in phosphorylated-Akt and -Bad expressions and eliminated tolerance of SIRPC mice kidneys to I/R insult.CONCLUSION: Ischemic pre-conditioning confers renal resistance to I/R-induced apoptosis via activation of the Akt signal pathway.
[show abstract][hide abstract] ABSTRACT: This paper proposes a new design technique for a reconfigurable CMOS Class E power amplifier (PA) by selectively activating the transistor cells in the array of power transistors. The activated transistors will be used for amplification and the non-activated transistors will be used for input/output matching and switching capacitance for Class E operation. The quad-band PA for 1.9/2.3/2.6/3.5 GHz has been implemented in a 0.18 μm CMOS technology using the technique without any switch or tunable circuit. This PA obtains output powers of 24.2/23.8/23.4/ 20.5 dBm and efficiency of 48.2/44.3/40.9/35.6% at 1.9/2.3/2.6/ 3.5 GHz. The total MMIC chip size is as small as 0.92 × 1.75 mm<sup>2</sup> for the reconfigurable quad-band operation.
[show abstract][hide abstract] ABSTRACT: This letter demonstrates a high-dynamic range GaAs heterojunction bipolar transistor Class E power amplifier (PA) for a WCDMA envelope elimination and restoration transmitter using a dual-mode amplification. An impedance optimization can operate the lossless high-power Class E mode and lossless low-power Class AB mode. This PA has a high dynamic range of -50 dBm to 27 dBm and obtains a remarkably improved efficiency of 9% and 27% power-added efficiency (PAE) at output powers of 0 dBm and 10 dBm, respectively, for low-power mode, and 40% and 48% PAE at 20 and 27 dBm, respectively, for high-power mode.
[show abstract][hide abstract] ABSTRACT: Tissue distribution and urinary excretion of nicotine, cotinine, and hydroxycotinine after multiple oral administration of nicotine to rats for 4 weeks were studied. Physiological change and serum biochemical parameters were also measured to check dysfunction of organs. Significant change of glutathione S-transferase, aspartate aminotransferase, blood urea nitrogen, and physiological parameters indicated the toxicity in liver and kidney, at the dose of 5 and 10 mg/kg/day. Only the concentration and total amount of cotinine, not nicotine or hydroxycotinine, in the liver and the kidney showed a proportional dose-dependent increase and were highly correlated with toxicity. Saturation of metabolizing enzymes for nicotine was estimated by the change of urinary excreted amount ratio between nicotine and its metabolites. Metabolizing enzyme to produce cotinine from nicotine was saturated after multiple oral dosing for 4 weeks in a low dose (1 mg/kg/day), but within 1 week in the dose of 5 and 10 mg/kg/day.
Drug and Chemical Toxicology 04/2010; 33(2):166-72. · 1.29 Impact Factor
[show abstract][hide abstract] ABSTRACT: Three different doses of valproic acid (20, 100, and 500 mg/kg/d) are administered orally to Sprague-Dawley rats for 5 days, and the feasibility of metabolomics with gas chromatography-mass spectrometry as a predictor of the hepatotoxicity of valproic acid is evaluated. Body weight is found to decrease with the 100-mg/kg/d dose and significantly decrease with the 500-mg/kg/d dose. Mean excreted urine volume is lowest in the 500-mg/kg/d group among all groups. The plasma level of alpha-glutathione-S-transferase, a sensitive and earlier biomarker for hepatotoxicity, increases significantly with administration of 100 and 500 mg/kg/d; however, there is not a significant difference in alpha-glutathione-S-transferase plasma levels between the control and 20-mg/kg/d groups. Clusters in partial least squares discriminant analysis score plots show similar patterns, with changes in physiological conditions and plasma levels of alpha-glutathione-S-transferase; the cluster for the control and 20-mg/kg/d groups does not clearly separate, but the clusters are separate for 100- and 500-mg/kg/d groups. A biomarker of hepatotoxicity, 8-hydroxy-2'-deoxyguanosine and octanoylcarnitine, is identified from nontargeted and targeted metabolic profiling. These results validate that metabolic profiling using gas chromatography-mass spectrometry could be a useful tool for finding novel biomarkers. Thus, a nontargeted metabolic profiling method is established to evaluate the hepatotoxicity of valproic acid and demonstrates proof-of-concept that metabolomic approach with gas chromatography-mass spectrometry has great potential for predicting valproic acid-induced hepatotoxicity and discovering novel biomarkers.
International Journal of Toxicology 08/2009; 28(5):392-404. · 1.35 Impact Factor
[show abstract][hide abstract] ABSTRACT: For a narrow slit structure backed by a conducting strip which is taken as a representative example of an aperture-body resonance (ABR) problem, the transmission resonance condition (i.e., condition for maximum power transmission) and the transmission width (i.e., normalized maximum transmitted power through the slit) are found to be the same as those for narrow slit coupling problem in a thick conducting screen, which is designated as a transmission-cavity resonance (TCR) problem. From a viewpoint of equivalent circuit representation for the transmission resonance condition and the funneling mechanism, the ABR and the TCR problems are thought to be essentially of the same nature. Comment: 14 pages, 3 figures
[show abstract][hide abstract] ABSTRACT: Cytosolic NADP+-dependent isocitrate dehydrogenase (IDPc) synthesizes reduced NADP (NADPH), which is an essential cofactor for the generation of reduced glutathione (GSH), the most abundant and important antioxidant in mammalian cells. We investigated the role of IDPc in kidney ischemia-reperfusion (I/R) in mice. The activity and expression of IDPc were highest in the cortex, modest in the outer medulla, and lowest in the inner medulla. NADPH levels were greatest in the cortex. IDPc expression in the S1 and S2 segments of proximal tubules was higher than in the S3 segment, which is much more susceptible to I/R. IDPc protein was also highly expressed in the mitochondrion-rich intercalated cells of the collecting duct. IDPc activity was 10- to 30-fold higher than the activity of glucose-6-phosphate dehydrogenase, another producer of cytosolic NADPH, in various kidney regions. This study identifies that IDPc may be the primary source of NADPH in the kidney. I/R significantly reduced IDPc expression and activity and NADPH production and increased the ratio of oxidized glutathione to total glutathione [GSSG/(GSH+GSSG)], resulting in kidney dysfunction, tubular cell damage, and lipid peroxidation. In LLC-PK(1) cells, upregulation of IDPc by IDPc gene transfer protected the cells against hydrogen peroxide, enhancing NADPH production, inhibiting the increase of GSSG/(GSH+GSSG), and reducing lipid peroxidation. IDPc downregulation by small interference RNA treatment presented results contrasting with the upregulation. In conclusion, these results demonstrate that IDPc is expressed differentially along tubules in patterns that may contribute to differences in susceptibility to injury, is a major enzyme in cytosolic NADPH generation in kidney, and is downregulated with I/R.
American journal of physiology. Renal physiology 01/2009; 296(3):F622-33. · 3.61 Impact Factor
[show abstract][hide abstract] ABSTRACT: An oxygen transport ceramic membrane was prepared with La0.6Sr0.4TixFe1−xO3−δ (x = 0.2 and 0.3) oxides which was synthesized by polymerized complex method. In order to investigate the effects of Ti substitutions into lanthanum–strontium ferrites, material property, thermal expansion coefficient, oxygen permeation, electrical conductivity and phase stability were examined according to Ti contents. The thermal expansion coefficients of LSTF6428 and LSTF6437 were 25.76 × 10−6 K−1 and 21.32 × 10−6 K−1 in the temperature range of 973−1273 K, respectively. The oxygen permeation fluxes through a disk type dense membrane of LSTF6428 and LSTF6437 with 1.6 mm thickness increased exponentially with increasing temperature and were 0.17 mL min−1cm–2 and 0.13 mL min−1cm−2 with Ph = 0.21 atm (O2 rich side) and Pl = 10−5 atm (lean side) at 1223 K, respectively. In the result of phase stability test with various conditions such as He, H2/N2 and CO2 atmosphere, La0.6Sr0.4TixFe1−xO3−δ was confirmed to be more stable than La0.6Sr0.4Ti0.2Fe0.8O3−δ through XRD and SEM analysis.
[show abstract][hide abstract] ABSTRACT: With a simple model for a surfactant consisting of a hydrophilic head group and hydrophobic tail groups connected by harmonic
springs, the structural change of the association structures of the surfactant in an aqueous solution was studied by using
the dissipative particle dynamics (DPD) simulation. The effect of the interaction parameter of DPD particles on the structural
change of the association structures was also studied. Simulations show that the proper relative values of these interaction
parameters could yield desirable changes for the association structure depending on the concentration of the surfactant. That
is, a spherical structure forms at ϕ=0.15, structural change from a spherical to cylindrical one occurs at ϕ=0.26, and a hexagonal
structure appears at ϕ=0.30, where ϕ is the volume fraction of surfactant SDS (sodium dodecyl sulfate), and they are in good
agreement with observation.
Key wordsAssociation Structure-Dissipative Particle Dynamics (DPD) Simulation-Sodium Dodecyl Sulfonate (SDS)-Structural Transition-Surfactant Solution
Korean Journal of Chemical Engineering 01/2009; 26(6):1717-1722. · 1.06 Impact Factor
[show abstract][hide abstract] ABSTRACT: A radio frequency power amplifier microwave monolithic integrated circuit with a series LC resonant circuit as well as a bias control circuit for wide-band code division multiple access application is presented. The linearizer that consists of a series LC resonant circuit and base-emitter junction of a bias transistor operates as a diode rectifier circuit. A comparison between the circuits with and without the linearizer has been demonstrated. The power amplifier (PA) with the series LC resonant linearizer exhibits adjacent channel leakage ratio-1 (ACLR1) of -37.2 dBc at output power of 27 dBm, a 5.6 dB improvement compared to the circuit without the linearizer. The bias control circuit reduces consumed average dc current from 83 mA to 57 mA for efficiency improvement. The linearized PA exhibits 1-dB compression point (P<sub>1</sub>dB) of 29.3 dBm, power-added efficiency of 45.7%, and power gain of 20.6 dB at low quiescent current of 37 mA with a 3.4 V single supply.
[show abstract][hide abstract] ABSTRACT: The distribution of conjugative-plasmid-mediated 16S rRNA methylase genes among amikacin-resistant Enterobacteriaceae collected between 1995 and 1998 and between 2001 and 2006 at a university hospital in South Korea was examined, and conjugative plasmids carrying the 16S rRNA methylase genes were characterized by PCR-based replicon typing and by determination of their antimicrobial resistance pattern. Among the 7,127 isolates, 463 isolates showed a high level of resistance to amikacin, and 218 of the 463 isolates transferred amikacin resistance by conjugation. Among the 218 isolates, armA was detected in 153 isolates (88 Klebsiella pneumoniae, 28 Escherichia coli, 19 Enterobacter cloacae, and 6 Serratia marcescens isolates and 12 isolates of other organisms), and rmtB was detected in 51 isolates (32 K. pneumoniae isolates, 18 E. coli isolates, and 1 Citrobacter freundii isolate). The first appearance of armA was in 1997. The armA gene was carried by conjugative plasmids of replicon groups IncL/M, IncFIIAs, IncF, IncA/C, IncHI2, and Inc(unidentified) in 38, 20, 7, 9, 4, and 75 strains, respectively. The rmtB gene was carried by conjugative plasmids of groups IncA/C, IncF, and IncI1-Igamma in 43 strains, 7 strains, and 1 strain, respectively. Transconjugants that received the IncL/M plasmid carrying armA or the IncA/C plasmid carrying rmtB showed an additional resistance to cefotaxime. Transconjugants that received the IncFIIA plasmid or Inc(unidentified) plasmid carrying the armA gene showed an additional resistance to cefoxitin and a high MIC(50) (0.25 mg/liter) of ciprofloxacin. In conclusion, this study demonstrated that the dissemination of 16S rRNA methylase genes among the Enterobacteriaceae is mediated by conjugative plasmids of various incompatibility groups that confer resistance to multiple drugs, including aminoglycosides, extended-spectrum beta-lactams, and/or quinolones.
Journal of clinical microbiology 03/2008; 46(2):700-6. · 4.16 Impact Factor
[show abstract][hide abstract] ABSTRACT: Previous studies have shown that cilostazol may not only prevent stent thrombosis, but may also have positive effect in the prevention of restenosis. However, the effect of cilostazol on restenosis after successful deployment of drug-eluting stent (DES) in patients with diabetes mellitus has not been evaluated.
A total of 280 patients at 8 clinical sites were randomized. The patients (61.7+/-9.9 years old, 163 males) who underwent successful stenting were randomized to aspirin and cilostazol (group I, n=141, 61.2+/-9.6 years old) vs aspirin and clopidogrel (group II, n=139, 62.0+/-10.0 years old) after 1 month of aspirin, cilostazol, and clopidogrel combination treatment. There were no significant differences in baseline characteristics of the groups. The type of DES implanted did not differ between the groups. There were no differences in angiographic and procedural characteristics of the groups. Major adverse cardiac events, including acute and subacute stent thrombosis within 1 month, did not occur in either group. Cases of angiographic late stent thrombosis were 1 (0.9%) in group I and 1 (0.8%) in group II. Follow-up coronary angiography was performed in 237 patients (84.6%). Mean follow-up duration was 7.1 months. The rate of angiographic restenosis (stent plus 5-mm borders) was 9 (8.0%) in group I and 20 (16.1%) in group II, p=0.041). The minimal luminal diameter at follow-up period in group I was 2.55+/-0.63 mm compared with 2.41+/-0.83 mm in group II (p=NS).
Combination therapy with aspirin and cilostazol for the prevention of stent restenosis is comparable or superior to that of aspirin and clopidogrel in diabetic patients who undergo DES implantation.
[show abstract][hide abstract] ABSTRACT: This paper demonstrates an efficiency improvement of the class E power amplifier (PA) by tuning-out the input capacitance (CIN) of the power HBT with a shunt inductance. In order to obtain high output power, the PA needs the large emitter size of a transistor. The larger the emitter size, the higher the parasitic capacitance. The parasitic CIN affects the distortion of the voltage signal at the base node and changes the duty cycle to decrease the PA's efficiency. Adopting the L-C resonance, we obtain a remarkable efficiency improvement of as much as 7%. This PA exhibits output power of 29 dBm and collector efficiency of 71 % at 1.9 GHz.
[show abstract][hide abstract] ABSTRACT: The nonlinear behavior of individual bubbles in liquid under periodic pressure fields has drawn considerable attention in conjunction with the design of sonochemical reactor and sonoluminescence phenomena. In this study, the motion of bubble under ultrasound was predicted by a set of solutions of the Navier–Stokes equations for the gas inside a spherical bubble and an analytical treatment of the Navier–Stokes equations for the liquid adjacent to the bubble wall. The theory permits one to predict correctly the bubble radius–time curve and the characteristics of the sonoluminescing gas bubble in sulfuric acid solutions, such as the peak temperature and pressure at the collapse point. It has turned out that the heat transfer inside the bubble and the liquid layer plays a major role in the bubble behavior. Mass transfer through the interface does not affect the bubble motion.
[show abstract][hide abstract] ABSTRACT: This paper discusses a method of determining the optimal price schedule for storing inbound containers in a container yard. The price schedule in this study is characterized by the free-time-limit during which a container can be stored without any charge, and by the storage price per unit time for the storage beyond the free-time-limit. The profit or cost models for optimal price schedule are developed from the viewpoint of a public terminal operator as well as a private terminal operator. The probability distribution of delivery times is expressed by a continuous probability function. Various characteristics of the optimal solution are analyzed by numerical experiments.
Transportation Research Part B: Methodological. 01/2007;
[show abstract][hide abstract] ABSTRACT: Temperature and pressure fields generated by the collapsing bubble of microsize in liquid under ultrasound are estimated by a set of solutions of the Navier-Stokes equations for the gas inside bubble with considering heat transfer through the bubble wall. The calculation results for the peak temperature and pressure were compared to the observed ones from a sonoluminescing bubble which can be levitated in a spherical cell under ultrasound frequency range of 10-40 kHz. The calculation results are in good agreement with observed ones. However, the Rayleigh-Plesset equation with polytropic relation, a conventional method yields considerably underestimated values in temperature and overestimated ones in pressure. The bubble dynamics model presented in this study may be used as a tool for the design of sonochemical reactor where the peak temperature and pressure and the pressure field due to the bubble collape are important parameters.
[show abstract][hide abstract] ABSTRACT: Sonoluminescence is the light emission associated with the catastrophic collapse of a bubble oscillating under ultrasound. Molecular dynamics (MD) simulation of a collapsing bubble in sulfuric acid solution was performed and the results from the simulation were compared with the theoretical results which are in good agreement with observed ones. The molecules inside the collapsing noble gas bubble were modeled as hard sphere ones and the instantaneous bubble radius and the bubble wall velocity which were used in the simulation were obtained from the Keller-Miksis equation with pressure data taken from MD simulation. One million particles were used in the scaled-down MD simulation of the sonoluminescing bubble with equilibrium radius of 15 mum having 1011 molecules. Remarkable agreement between the MD simulation results and theoretical calculation values was obtained for the adiabatic process. However, the heat bath boundary condition yields much shorter thermal spike than the theoretical value even though the peak temperature obtained is similar to the theoretical one.
Journal of the Physical Society of Japan 01/2007; 76. · 2.09 Impact Factor