New lanostanes and naphthoquinones isolated from Antrodia salmonea and their antioxidative burst activity in human leukocytes

Four new compounds were isolated from the basidiomata of the fungus Antrodia salmonea, a newly identified species of Antrodia (Aphyllophorales) in Taiwan. These new compounds are named as lanosta-8,24-diene-3 beta,15 alpha,21-triol (1), 24-methylenelanost-8-ene-3 beta,15 alpha,21-triol (2), 2,3-dimethoxy-5-(2',5'-dimethoxy-3',4'-methylenedioxyphenyl)-7-methyl-[1,4]-naphthoquinone (3), and 2,3-dimethoxy-6-(2,5'-dimethoxy-3',4'-methylenedioxyphenyl)-7-methyl-[1,4]-naphthoquinone (4), respectively. Their structures were elucidated by spectroscopic methods. An in vitro cellular functional assay was performed to evaluate their anti-oxidative burst activity in human leukocytes. They showed inhibitory effects against phorbol 12-myristate-13-acetate (PMA), a direct protein kinase C activator, induced oxidative burst in neutrophils (PMN) and mononuclear cells (MNC) with 50% inhibitory concentration (IC50) ranging from 3.5 to 25.8 mu M. The potency order of these compounds in PMA-activated leukocytes was as 1 > 3 > 4 > 2. They were relatively less effective in formyl-Met-Leu-Phe (fMLP), a G-protein coupled receptor agonist, induced oxidative burst, except for compounds 3 and 4 in fMLP-activated PMN. These results indicated that three (1, 3, and 4) of these four newly identified compounds displayed antioxidative effect in human leukocytes with different potency and might confer anti-inflammatory activity to these drugs

Andrographolide Inhibits PI3K/AKT-Dependent NOX2 and iNOS Expression Protecting Mice against Hypoxia/Ischemia-Induced Oxidative Brain Injury

This study aimed to explore the mechanisms by which andrographolide protects against hypoxia-induced oxidative/nitrosative brain injury provoked by cerebral ischemic/reperfusion (CI/R) injury in mice. Hypoxia in vitro was modeled using oxygen-glucose deprivation (OGD) followed by reoxygenation of BV-2 microglial cells. Our results showed that treatment of mice that have undergone CI/R injury with andrographolide (10-100 mu g/kg, i.v.) at 1 h after hypoxia ameliorated CI/R-induced oxidative/nitrosative stress, brain infarction, and neurological deficits in the mice, and enhanced their survival rate. CI/R induced a remarkable production in the mouse brains of reactive oxygen species (ROS) and a significant increase in protein nitrosylation; this primarily resulted from enhanced expression of NADPH oxidase 2 (NOX2), inducible nitric oxide synthase (iNOS), and the infiltration of CD11b cells due to activation of nuclear factor-kappa B (NF-kappa B) and hypoxia-inducible factor 1-alpha (HIF-1 alpha). All these changes were significantly diminished by andrographolide. In BV-2 cells, OGD induced ROS and nitric oxide production by upregulating NOX2 and iNOS via the phosphatidylinositol-3-kinase (PI3K)/AKT-dependent NF-kappa B and HIF-1 alpha pathways, and these changes were suppressed by andrographolide and LY294002. Our results indicate that andrographolide reduces NOX2 and iNOS expression possibly by impairing PI3K/AKT-dependent NF-kappa B and HIF-1 alpha activation. This compromises microglial activation, which then, in turn, mediates andrographolide's protective effect in the CI/R mice

The Anti-Cancer Effects of (-)-Epigalocathine-3-Gallate on the Signaling Pathways Associated With Membrane Receptors in MCF-7 Cells

(-)-Epigallocatechin-3-gallate (EGCg) has been implicated in cancer chemo-prevention in studies using many different kinds of cancer cells. The present study measured cell viability, osteopontin (OPN) secretion, fatty acid synthase (FAS) expression, and cytosolic Ca(2+) and verified the anti-cancer activities of EGCg in MCF-7 human breast cancer cells. EGCg-induced apoptosis was evidenced by nuclear condensation, increased protein levels of activated caspase-3, down-regulation of gelsolin and tropomyosin-4 (Tm-4), and up-regulation of tropomyosin-1(Tm-1). By disrupting adherens junction formation, EGCg caused accumulation of extra-nuclear beta-catenin aggregates in the cytosol and alterations of the protein content and mRNA expression of E-cadherin and beta-catenin, but not N-cadherin, in MCF-7 cells. To identify the putative mechanisms underlying the EGCg signaling pathways, EGFP (enhanced green fluorescence protein) was ectopically expressed in MCF-7 cells. This allowed us to monitor the EGCg-induced fluorescence changes associated with the effects of Triton X-100 (to remove plasma membrane) or the addition of laminin, anti-laminin receptor (LR) antibody, epidermal growth factor (EGF), and genistein on the cells. Our results indicated that EGCg acts via the signaling pathways associated with cell membrane to suppress cell proliferation, provoke apoptosis, and disturb cell-cell adhesion in MCF-7 cells. The altered events include the EGFR, LR, FAS, intracellular Ca(2+), OPN secretion, caspace-3, gelsolin, Tm-4, Tm-1, and adherens junction proteins, E-cadherin and beta-catenin. J. Cell. Physiol. 226: 2721-2730, 2011. (C) 2010 Wiley-Liss, Inc

Sediment Movement Induced by Ships in Restricted Waterways

A numerical model using the momentum theory of the propeller and Shields' diagram was developed to study sediment movement induced by a ship's propeller in a restricted waterway. The velocity distribution downstream of the propeller was simulated by the Gaussian normal distribution function. The shear velocity and shear stress were obtained using Sternberg's formulas. Once the ship's speed, depth of the waterway, RPM and diameter of the propeller, and draft of the ship are given, the velocity distribution and the grain size of the initial motion could be obtained from this model. A computer program was developed to solve it. Case studies are presented to show the influence of significant factors on sediment movement at the channel bottom induced by a ship's propeller.Ocean Engineering Progra

The inhibitory effect of phenylpropanoid glycosides and iridoid glucosides on free radical production and beta 2 integrin expression in human leucocytes

Rapid production of reactive oxygen species (ROS) and upregulation of beta 2 integrin by leucocytes are two important inflammatory responses in human leucocytes. To evaluate whether three phenylpropanoid glycosides (acteoside, crenatoside, and rossicaside B) and two iridoid glucosides (boschnaloside and 8-epideoxyloganic acid) identified from two medicinal plants with similar indications (Orobanche caerulescens and Boschniakia rossica) exhibited anti-inflammatory activity, their effects on N-formyl-methionyl-leucyl-phenylalanine (fMLP) and phorbol-12-myristate-13-acetate (PMA)-activated peripheral human neutrophils (PMNs) and mononuclear cells were examined. Pretreatment with 1-50 mu M phenylpropanoid glycoside concentration-dependently diminished PMA- and fMLP-induced ROS production with IC50 values of approximately 6.8-23.9 and 3.0-8.8 mu M, respectively. Iridoid glucoside was less effective than phenylpropanoid glycoside with an IC50 value of approximately 8.9-28.4 mu M in PMA-activated PMNs and 19.1-21.1 mu M in fMLP-activated mononuclear cells. Phenylpropanoid glycosides also effectively inhibited NADPH oxidase (NOX) and displayed potent free radical-scavenging activity, but did not interfere with pan-protein kinase C (PKC) activity. Furthermore, all compounds, except rossicaside B, significantly inhibited PMA- and fMLP-induced Mac-1 (a beta 2 integrin) upregulation at 50 mu M but not that of fMLP-induced intracellular calcium mobilization. These drugs had no significant cytotoxicity as compared with the vehicle control. Our data suggested that inhibition of ROS production, possibly through modulation of NOX activity and/or the radical scavenging effect, and beta 2 integrin expression in leucocytes indicated that these compounds had the potential to serve as anti-inflammatory agents during oxidative stress

Electrochemical and Spectral Characterizations of 9-Phenylcarbazoles

A series of 9-phenylcarbazoles have been synthesized and characterized for their electrochemical as well as spectral properties. For 3,6-substituted carbazoles, the oxidation is reversible and the potential is affected by the substituents. For 3,6-unprotected carbazoles, on the other hand, the oxidized forms can undergo dimerization. Their corresponding dimers have been independently synthesized by chemical methods and have exhibited identical spectral properties. The para position of the 9-phenyl group is relatively insensitive for redox and chemical reactions. The amino derivatives are unstable in carbazole cation radical form compared with their triphenylamine counterparts

Single-Doppler Velocity Retrieval of the Wind Field in a Tornadic Supercell Using Mobile, Phased-Array, Doppler Radar Data

The article of record as published may be found at https://doi.org/10.1175/JTECH-D-18-0004.1A three-dimensional data assimilation (3DVar) least squares–type single-Doppler velocity retrieval (SDVR) algorithm is utilized to retrieve the wind field of a tornadic supercell using data collected by a mobile, phased- array, Doppler radar [Mobile Weather Radar (MWR) 05XP] with very high temporal resolution (6 s). It is found that the cyclonic circulation in the hook-echo region can be successfully recovered by the SDVR algorithm. The quality of the SDVR analyses is evaluated by dual-Doppler syntheses using data collected by two mobile Doppler radars [Doppler on Wheels 6 and 7 (DOW6 and DOW7, respectively)]. A comparison between the SDVR analyses and dual-Doppler syntheses confirms the conclusion reached by an earlier theoretical analysis that be- cause of the temporally discrete nature of the radar data, the wind speed retrieved by single-Doppler radar is always underestimated, and this underestimate occurs more significantly for the azimuthal (crossbeam) wind component than for the radial (along beam) component. However, the underestimate can be mitigated by in- creasing the radar data temporal resolution. When the radar data are collected at a sufficiently high rate, the azimuthal wind component may be overestimated. Even with data from a rapid scan, phased-array, Doppler radar, our study indicates that it is still necessary to calculate the SDVR in an optimal moving frame of reference. Finally, the SDVR algorithm’s robustness is demonstrated. Even with a temporal resolution (2 min) much lower than that of the phased-array radar, the cyclonic flow structure in the hook-echo region can still be retrieved through SDVR using data observed by DOW6 or DOW7, although a difference in the retrieved fields does exist. A further analysis indicates that this difference is caused by the location of the radars

Prevention of macrophage adhesion molecule-1 (Mac-1)-dependent neutrophil firm adhesion by taxifolin through impairment of protein kinase-dependent NADPH oxidase activation and antagonism of G protein-mediated calcium influx

Taxifolin has been reported to down-regulate the expression of intercellular adhesion molecule-1 (ICAM-1), a receptor-mediating firm adhesion with beta2 integrin (e.g., Mac-1) expressed on leukocytes. To evaluate whether taxifolin could modulate Mac-1-dependent firm adhesion by neutrophils, and the possible mechanism(s) underlying its anti-inflammatory action, its effects on N-formyl-methionyl-leucyl-phenylalanine (fMLP) or phorbol-12-myristate-13-acetate (PMA)-activated peripheral human neutrophils were studied. Pretreatment with taxifolin (1-100 muM) concentration-dependently diminished fMLP- or (PMA)-induced Mac-1-dependent firm adhesion and upexpression of surface Mac-L Mobilisation of intracellular calcium and production of reactive oxygen species (ROS) signal the upexpression of Mac-1 and firm adhesion by neutrophils. Taxifolin impeded the calcium influx induced by fMLP (a receptor-mediated activator) or AlF4- (a G protein-mediated activator). Taxifolin also effectively inhibited the fMLP- or PMA-induced ROS production with 50% inhibitory concentration (IC50) less than 10 muM, possibly through impairing the activation of NADPH oxidase, a major ROS-generating enzyme in neutrophils, by restricting the activation of p38 mitogen-activated protein kinase (p38 MAPK) and protein kinase C (PKC). In conclusion, we propose that impairment of ROS production by NADPH oxidase through interfering with p38 MAPK- and/or PKC-dependent signals, and antagonism of G protein-mediated calcium influx may account for the inhibition of Mac-1-dependent neutrophil firm adhesion that confers taxifolin the anti-inflammatory activity. (C) 2004 Elsevier Inc. All rights reserved

Influences of reinforcing bars on crack depth measurement by stress waves

A research program was undertaken to evaluate the influences of steel reinforcing bars oil signals obtained from depth measurements of sui face-opening cracks in reinforced concrete structures based on transient stress waves generated by elastic impact. Numerical studies were performed to gain an understanding of the interaction of transient stress waves with steel bars in concrete structures containing surface-opening cracks. A reinforced concrete beam was constructed as an experimental specimen. The specimen was simply supported and loaded at the center point until cracks occurred. Experimental studies were carried out on the cracked beam. Two displacement receivers were placed on the opposite sides of a surface-opening crack to monitor disturbances caused by the arrivals of stress waves generated by impact. The first receiver and impact were located on the same side of the crack. The first receiver was used to trace the start rime of impact. The second one placed oil the opposite sine of the crack was used to find the arrival time of P-wave propagating through steel bars, and the arrival time of the diffracted P-wave from the bottom edge of the crack, Numerical and experimental results show: that rite presence of steel bars results in an initial disturbance in the waveform recorded by the second receiver because P-waves call propagate across the crack along the steel bars. it is also shown that the shortest travel path Soi a P-wave from the impact point through the steel bars to the second receiver is obtained if rile P-wave is incident upon the concrete/steel interface with a critical angle of incidence. Equations for determining rite depth of steel bars are presented. Because the amplitude of the initial disturbance caused by the steel bars is small, it is still easy to identify the following arrival of the P-wave diffracted from the bottom edge of the crack. Thus, the presence of steel reinforcing bars does not have a significant influence on measuring the crack depth

New technique based on stress waves for measuring cover thickness of closely spaced reinforcing bars

The objective of the research presented in this paper is to develop a new nondestructive test method to determine the cover thickness of reinforcing bars in concrete structures that contain closely arranged reinforcing bars. Even though the commercial covermeters based on magnetic and electrical methods are widely used in the detection of the depth and location of reinforcing bars, they are not suitable in the case of bars with small spacing. The technique proposed in this paper for detection of the closely arranged reinforcing bars makes use of stress waves. The conception of the new test scheme originated from the fact that the propagation of stress waves follows the shortest travel path dominated by the reinforcing bar under the test point and is not affected by adjacent reinforcing bars. Numerical studies were performed to investigate how the travel time of a P-wave propagating through reinforcing bars is changed as the test line is moved away from the axis of the reinforcing bars. Experimental studies were performed on concrete specimens that contain reinforcing bars with close spacing. Results obtained from numerical analysis show that when the test point is not exactly above the steel bar the travel time for a P-wave is increased with an increase in distance from the test line to the reinforcing bar Experimental results show that no matter how close the reinforcing bars are placed in concrete specimens, the cover thickness of the bars can be still measured accurately