199 research outputs found

    Induction of embryonal carcinoma cell differentiation by deferoxamine, a potent therapeutic iron chelator

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    AbstractWe investigated the effects of deferoxamine on the differentiation of embryonal carcinoma F9 cells. Deferoxamine, a widely used therapeutic agent for thalassemia and iron overload, was found to induce F9 cell differentiation and to have some unique characteristics compared with other chelators, hinokitiol and dithizone, which were previously reported to induce differentiation of these cells. This hydrophilic agent induced reversible differentiation as did sodium butyrate, whereas other chelators did not. However, morphological features of the cells after deferoxamine-induced differentiation were similar to those of cells incubated with the other chelators. The differentiation-inducing activity of deferoxamine was abolished by preincubation with Fe3+ ions, similarly to the other chelators examined. Moreover, cell proliferation was inhibited by treatment with this agent, and the numbers of cells in the colonies were reduced by apoptosis. Based on these results, we conclude that deferoxamine induces differentiation and apoptosis of F9 cells via chelation of extracellular and/or intracellular Fe3+ ions

    Endothelium-dependent vasodilator effect of tannin extract from Cinnamonomi Cortex on isolated rat aorta

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    Cinnamonomi Cortex (the bark of Cinnamomum cassia BLUME) is a crude drug that is widely used in spices and medical products. Although improvement of blood flow by this plant component has long been known, there have been no reports concerning the mechanism involved. We studied the vasodilator actions of this drug especially focusing on the role of endothelium in the isolated vascular bed. Tannin from Cinnamonomi Cortex (TCC) relaxed prostaglandin F_-precontracted ring preparations of rat aorta with intact endothelium. TCC did not cause relaxation of specimens without endothelium, and TCC-induced relaxation was inhibited by pretreatment with 10^M N^G-nitro-l-arginine methyl ester. Dimer, trimer, tetramer, and pentamer components of TCC also produced endothelium-dependent vasodilatation. Stronger relaxation was caused by higher molecular weight tannins, and endothelium-dependent vasodilation even appeared at low concentrations. In conclusion, we found that TCC exhibits an endothelium-dependent vasodilatation in the isolated rat aorta mainly via endothelium derived NO. NO mediated endothelium-dependent relaxation seems to be more potent for TCC with higher molecular weight than that with lower molecular weight. 桂皮の血流改善作用については古くから知られており,これに関連した報告はあるものの,その詳細な検討はなされていない。今回我々はマグヌス法を用いて,ラット胸部大動脈輪状標本における桂皮含有クンニンの血管作動性について検討した。桂皮含有タンニンは,プロスタグランディンF_(PGF_)の血管収縮に対し,内皮保存血管において濃度依存性に血管弛緩作用が認められた。しかし,内皮除去血管及ぴN^G-nitro-l-argininemethyl ester(L-NAME)前処置内皮保存血管においては,血管弛緩作用はほぼ消失した。以上より,桂皮含有タンニンの血管弛緩作用は内皮依存性であることが明らかとなった。桂皮含有タンニンをさらに二量体から五量体までのタンニン画分に分取し検討したところ,二量体以上の重合したタンニンにおいて血管弛緩作用が認められた。また,重合度が増すに従い血管弛緩作用はより低い濃度で発揮され,作用も増強されることが明らかとなった

    Exercise hyperpnea and hypercapnic ventilatory responses in women

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    SummaryWe studied the relationship between exercise hyperpnea (i.e., ventilatory dynamics) at the onset of exercise and hypercapnic ventilatory response (HCVR), and their differences between the follicular (FP) and luteal (LP) phases of the menstrual cycle in six healthy females. HCVR was tested under three O2 conditions: hyperoxia (FiO2=1.0), normoxia (0.21), and hypoxia (0.12). HCVR was defined as the relationship between the end-tidal PCO2 and minute ventilation (V˙E) using the regression line of the CO2 slope and a mimetically apneic threshold of CO2. HCVR provocation and measurements were conducted using an inspired CO2 concentration of up to approximately 8mmHg higher than the end-tidal PCO2 level of basal isocapnic the end-tidal PCO2 at each menstrual both the slope and threshold in HCVR showed no statistically significant difference between LP and FP under any inspired FiO2 conditions. In the case of exercise hyperpnea during the onset of submaximal exercise, the mean response time (MRT) in V˙E dynamics showed no significant difference between LP and FP. Consequently, MRT in V˙E response was not related to the slope in HCVR. During steady-state exercise, even though the V˙E/V˙CO2 showed no significance between LP and FP, V˙E/V˙CO2 was significantly related to the slope in HCVR (r=0.59, P<0.05). Exercise ventilation (i.e., V˙E/V˙CO2) would partly be adjusted by the enhancement of the chemoreflex drive to CO2 only during the steady-state exercise

    Cross-sectional particle measurement in the resonance domain on the substrate through scatterometry

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    We developed a versatile method for three-dimensional shape measurement where a specific particle can be selected on the substrate and its cross-sectional shape and size can be measured. A non-contact fast measurement is possible for the particle in the resonance domain. We applied rigorous coupled-wave analysis to the particle and calculated the diffraction patterns, comparing the patterns with the experimental results to obtain the size and shape. The shape and position of the focusing spot on the scattering particle was controlled precisely. With this method, the category of the analyzable object is extended to more shapes, such as rectangles and triangles, in addition to a conventional ellipsoid

    A check of operating model predictions from the viewpoint of the management procedure implementation in 2017

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    Values of the core vessels’ longline CPUE and aerial survey (AS) indices (two required inputs to the Bali management procedure) are compared to projection results obtained from the SBT operating model (OM). The most recent observations for the CPUE index and the AS index fall within the 95% probability envelopes predicted by the Base case OM in 2011. As regards a decision on implementation of the recommended TAC (calculated by the MP in 2016 for the 2018-2020 fishing seasons) for the 2018 season, it is considered that no modification of the value of this TAC is required because: 1) there is no evidence to support a declaration of Exceptional Circumstances from the viewpoints of a check of the OM predictions, this year’s in-depth stock assessment/projections, and other potential reasons (Indonesian small fish catch, overcatch of reported global TAC, unaccounted catch mortality); 2) no unexpected change has been detected in the fisheries’ indicators examined; and 3) there are no indications of any appreciable decline in recruitment indices for 2017

    Increased amyloidogenic processing of transgenic human APP in X11-like deficient mouse brain

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    <p>Abstract</p> <p>Background</p> <p>X11-family proteins, including X11, X11-like (X11L) and X11-like 2 (X11L2), bind to the cytoplasmic domain of amyloid β-protein precursor (APP) and regulate APP metabolism. Both X11 and X11L are expressed specifically in brain, while X11L2 is expressed ubiquitously. X11L is predominantly expressed in excitatory neurons, in contrast to X11, which is strongly expressed in inhibitory neurons. <it>In vivo </it>gene-knockout studies targeting X11, X11L, or both, and studies of X11 or X11L transgenic mice have reported that X11-family proteins suppress the amyloidogenic processing of endogenous mouse APP and ectopic human APP with one exception: knockout of X11, X11L or X11L2 has been found to suppress amyloidogenic metabolism in transgenic mice overexpressing the human Swedish mutant APP (APPswe) and the mutant human PS1, which lacks exon 9 (PS1dE9). Therefore, the data on X11-family protein function in transgenic human APP metabolism <it>in vivo </it>are inconsistent.</p> <p>Results</p> <p>To confirm the interaction of X11L with human APP ectopically expressed in mouse brain, we examined the amyloidogenic metabolism of human APP in two lines of human APP transgenic mice generated to also lack X11L. In agreement with previous reports from our lab and others, we found that the amyloidogenic metabolism of human APP increased in the absence of X11L.</p> <p>Conclusion</p> <p>X11L appears to aid in the suppression of amyloidogenic processing of human APP in brain <it>in vivo</it>, as has been demonstrated by previous studies using several human APP transgenic lines with various genetic backgrounds. X11L appears to regulate human APP in a manner similar to that seen in endogenous mouse APP metabolism.</p

    A Substellar Companion to the Intermediate-Mass Giant 11 Com

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    We report the detection of a substellar companion orbiting the intermediate-mass giant star 11 Com (G8 III). Precise Doppler measurements of the star from Xinglong station and Okayama Astrophysical Observatory (OAO) revealed Keplerian velocity variations with an orbital period of 326.03 +/- 0.32 days, a semiamplitude of 302.8 +/- 2.6 m/s, and an eccentricity of 0.231 +/- 0.005. Adopting a stellar mass of 2.7 +/- 0.3 M_solar, the minimum mass of the companion is 19.4 +/- 1.5 M_Jup, well above the deuterium burning limit, and the semimajor axis is 1.29 +/- 0.05 AU. This is the first result from the joint planet search program between China and Japan aiming at revealing statistics of substellar companions around intermediate-mass giants. 11 Com b emerged from 300 targets of the planet search program at OAO. The current detection rate of a brown dwarf candidate seems to be comparable to that around solar-type stars within orbital separations of \sim3 AU.Comment: 19 pages, 4 figures, accepted by Ap
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