Cancer chemoprevention with green tea catechins by targeting receptor tyrosine kinases

Recent studies indicate that receptor tyrosine kinases (RTKs), which play important roles in cell proliferation, are one of the possible targets of green tea catechins (GTCs) in cancer cell growth inhibition. (-)-Epigallocatechin-3-gallate (EGCG), the major catechin in green tea, inhibits cell proliferation and induces apoptosis in various types of cancer cells, including colorectal cancer and hepatocellular carcinoma cells, by blocking the activation of the epidermal growth factor receptor (EGFR) family of RTKs. EGCG inhibits the activation of insulin-like growth factor-1 receptor (IGF-1R) and VEGFR2, the other members of the RTK family, and this effect is also associated with the anticancer and chemopreventive properties of this agent. EGCG suppresses the activation of EGFR in part by altering membrane lipid organization and causing the subsequent inhibition of the dimerization and activation of this receptor. Preliminary trials have shown that GTCs successfully prevent the development and progression of precancerous lesions, such as colorectal adenomas, without causing severe adverse effects. The present report reviews evidence indicating that GTCs exert anticancer and chemopreventive effects by inhibiting the activation of specific RTKs, especially EGFR, IGF-1R, and VEGFR2, and concludes that targeting RTKs and their related signaling pathways by using tea catechins could be a promising strategy for the prevention of human cancers.     

Development of restoration system based on human performance model

A stable power supply is required from power systems as the importance of electrical energy increases. Particularly, in the case of high-voltage systems (500-, 275-, 154-kV bulk power systems), this requirement is high. However, there are cases when power system faults cannot be avoided. Accordingly, it is very important to restore power systems quickly and safely if these failures occur. The characteristics of the power system restoration (its combinatorial aspects, use of knowledge from a wide variety of origins and of different types, number of criteria to satisfy) make it a difficult problem, for which the use of expert systems to generate restoration plans is being considered by many researchers, and promising results have already been obtained. However, most systems are still in the prototype stage [1]. One reason seems to be the lack of studies of a support system for knowledge-based behavior (unable to describe with any rule). This paper analyzes first power system restoration based on the human performance model [6] and discusses the knowledge-based behavior that is a high conceptual level of human performance to solve the problem from the combinatorial viewpoint. Then the application for the trunk line dispatching center is reported. Finally, the relations between knowledge-based behavior and the designed human interfaces are verified with a power networks restoration case-study.     

Methanol synthesis from carbon dioxide at atmospheric pressure over Cu/ZnO catalyst. Role of methoxide species formed on ZnO support

Methanol synthesis from CO₂ and H₂ was carried out over a Cu/ZnO catalyst (Cu/Zn = 3/7) at atmospheric pressure, and the surface species formed were analyzed by diffuse reflectance FT-IR spectroscopy and temperature programmed desorption method. Two types of formate species and zinc methoxide were formed in the course of the reaction. Zinc methoxide was readily hydrolyzed to methanol. H₂O formed through the reverse water gas shift reaction was suggested to be involved in the hydrolysis of zinc methoxide.     

Many-Body Analysis of the Hess-Fairbank Effect in One-Dimensional Bose-Einstein Condensates with Attractive Interactions

No Heading In terms of the many-body energy spectrum obtained by a diagonalization of Hamiltonian, we discuss the Hess-Fiarbank effect in an attractive Bose-Einstein condensate on a one-dimensional ring. Depending on the strength of interaction and the rotational frequency of the container, there exist two characteristic features in the spectrum. We argue that the existence of a regime of a huge number of low-lying levels causes the smearing of the plateau of the quantized circulation in contrast to conventional superfluids with repulsive interaction.PACS numbers: 03.75.Hh, 03.75Lm     

Axin, a negative regulator of the Wnt signaling pathway, forms a complex with GSK-3beta and beta-catenin and promotes GSK-3beta-dependent phosphorylation of beta-catenin

Glycogen synthase kinase-3 (GSK-3) mediates epidermal growth factor, insulin and Wnt signals to various downstream events such as glycogen metabolism, gene expression, proliferation and differentiation. We have isolated here a GSK-3beta-interacting protein from a rat brain cDNA library using a yeast two-hybrid method. This protein consists of 832 amino acids and possesses Regulators of G protein Signaling (RGS) and dishevelled (Dsh) homologous domains in its N- and C-terminal regions, respectively. The predicted amino acid sequence of this GSK-3beta-interacting protein shows 94% identity with mouse Axin, which recently has been identified as a negative regulator of the Wnt signaling pathway; therefore, we termed this protein rAxin (rat Axin). rAxin interacted directly with, and was phosphorylated by, GSK-3beta. rAxin also interacted directly with the armadillo repeats of beta-catenin. The binding site of rAxin for GSK-3beta was distinct from the beta-catenin-binding site, and these three proteins formed a ternary complex. Furthermore, rAxin promoted GSK-3beta-dependent phosphorylation of beta-catenin. These results suggest that rAxin negatively regulates the Wnt signaling pathway by interacting with GSK-3beta and beta-catenin and mediating the signal from GSK-3beta to beta-catenin.     

Two color oscillations of TE-CO2 laser and applications to two photon process of optically pumped FIR laser

We have developed the resonance system which is able to operate a TE-CO₂ discharge tube in two color emission source. The two color source is excellent in pumping efficiency, spacial overlap and time synchronization of the two emission CO₂ lines. We indicate that the competitive operation of the two emissions is well explained by a simple model. When a TE-CO₂ laser operates at the total pressure of below half atmospheric pressure, we make clear in this work that the operation of a TE-CO₂ laser forms “depression” like hole burning, with regards to the J of the upper laser level by J-J collisional relaxation during the laser emission. As an example of the two-photon source, two-photon pumping of NH₃ and FIR emissions are given in this paper.     

Polyneuropathy due to ethylene oxide, propylene oxide, and butylene oxide

Radioligand exchange was examined for its ability to derive the dissociation constant (Kd) of the rat ventral prostate nuclear androgen receptor. In one 24-h, 12 degrees C incubation, Scatchard plot analysis of [3H]dihydrotestosterone ([3H]DHT) exchange binding produced a Kd of 6.9 x 10(-9) M. Specific binding of [3H]DHT ranged from 114 to 758 pM, and the extrapolated value for the total number of binding sites (n) was 1320 pM. When aliquots from the same receptor pool were incubated with unlabeled DHT, and bound androgen was measured by radioimmunoassay, each titration point held a concentration of specifically bound unlabeled DHT little different from the preincubation value of bound endogenous ligand (1338 pM), suggesting that few, if any, unoccupied sites were created during the incubation. In a second radioligand exchange assay, unoccupied receptor sites were measured at the end of incubation. Virtually no unoccupied sites were found, though the range of predicted values was 124 to 383 pM (n = 425 pM). The data, in toto, suggest that although radioactive ligand exchanges with bound unlabeled ligand, the dynamics of the process do not include the creation of unoccupied sites. Since the Kd is determined by measuring the concentrations of unoccupied sites, free ligand, and receptor sites bound to ligand, the absence of unoccupied sites suggests that radioligand exchange cannot be used to directly determine the Kd of the prostate nuclear androgen receptor. The numerical value obtained from radioligand exchange, therefore, instead of being a Kd, is very likely the result of a graphic plot of the increase in specific activity of bound radioligand as [3H]DHT is titrated to higher levels. In the last phase of the study a technique was developed which allows for the correct determination of the Kd of the rat ventral prostate nuclear androgen receptor. For the determination, data from an experiment measuring uptake binding into unoccupied sites were combined with data obtained from radioligand exchange binding. From this, the Kd of the receptor was calculated to be 1 x 10(-12) M.     

Test run of combined propulsion,levitation and guidance system at Miyazaki test track

In commercializing the superconducting Maglev system it is important to reduce the cost, especially that of ground coils constructed along the whole length of the guideway. For this purpose we have examined the combined propulsion, levitation and guidance system (PLG system) which can generate levitation, guidance and propulsion forces by the same coil. This paper describes the test run of the PLG system, whose ground coils (PLG coil) are constructed in one part of the Miyazaki test track. In designing the PLG coil, we make clear the magnitudes of the force acting both under normal and unusual conditions because the electromagnetic force, which levitates, guides, and propels the vehicle, directly acts on the magnet winding of the PLG coil. In the experiment, we examine both the performance of the vehicle and the force of a PLG coil. The measurement of the force at the PLG coil gives not only propulsion force and levitation force directly, but also guidance stiffness by sifting the measured coil. Good correlation recognized between the calculation and the experiment in the propulsion force, levitation force, and guidance stiffness proves that the required characteristics can be expected from the PLG system even under combination of propulsion, levitation and guidance.