Transepithelial transport of 6-O-caffeoylsophorose across Caco-2 cell monolayers

The aim of this study was to clarify the transport behaviour and mechanism of caffeic acid analogue bearing a sugar-moiety, 6-O-caffeoylsophorose (CS), in Caco-2 cells. The absorption of CS was investigated by its transport across Caco-2 cell monolayers using a high-performance liquid chromatography-time-of-flight-mass spectrometry (LC–TOF-MS). The permeation of CS was concentration-dependent and reached the plateau at >6 mM. The apparent permeability (P_app) of CS in the apical-to-basolateral direction was 5.4 × 10⁻⁷ cm/s, while in the reversed direction the P_app value was significantly reduced (1.9 × 10⁻⁷ cm/s). CS transport was competitively inhibited by phloretin, an inhibitor of monocarboxylic acid transporter (MCT). Benzoic acid, an MCT substrate, also reduced CS transport. A less significant change of CS transport was observed across Caco-2 cell monolayers pretreated with quercetin, a suppressor of tight-junction. These findings strongly indicate that CS, a caffeic acid analogue bearing sophorose moiety, can be transported across Caco-2 cell monolayers via the MCT pathway.     

PAF inhibitory activity of diketopiperazines: Structure-activity relationships

FR900452, a natural product isolated from the culture broth ofStreptomyces phaeofaciens No. 7739, was found to inhibit PAF-induced rabbit platelet aggregation with an IC₅₀ of 3.7×10⁻⁷M. FR900452, 1-methyl-3-[1-[5-methylthiomethyl-6-oxo-3-(2-oxo-3-cyclopenten-1-ylidene)-2-piperazinyl]ethyl]-2-indoline, has an oxocylopentylidene group incorporated as a vinylogous amide in a diketopiperazine skeleton. This unique structure led us to synthesize diketopiperazine derivatives, 3-arylalkyl-6-substituted-piperazine-2,5-diones. their observed PAF inhibitory activity suggest that the D-D configuration of diketopiperazine is an important factor for anti-PAF activity and that the hydrophobic aromatic portion may play a specific role in the binding of the diketopiperazine to the PAF receptor. Based on a paper presented at the Third International Conference on Platelet-Activating Factor and Structurally Related Ether Lipids Tokyo, Japan, May 1989.     

Analysis of correlations among supercontinuum spectra using liquid crystal spatial light modulator

The generation of supercontinuum spectra from the injection of femtosecond pulses into microstructure or tapered fibers has now been achieved by several groups [1, 2]. In 2001, we generated a supercontinuum around 1.55 µm by injecting a 100‐fs‐duration fiber laser pulse with a 1‐nJ pulse energy into a 5‐m‐long highly nonlinear dispersion‐shifted fiber. The supercontinuum is a remarkable light source for applications in many fields due to its extreme spectral broadness and simple generation scheme. These unique properties should make the supercontinuum an ideal tool for important applications, including WDM telecommunications, optical coherence tomography, and optical‐frequency measurement. However, significant broadband noise on the supercontinuum has been observed, limiting its stability, so that the supercontinuum is too noisy for many applications. In this study, we experimentally analyze the correlation among supercontinuum spectra that contribute to increasing and decreasing this noise by spectral filtering using spatial light modulator. We observed the formation of correlations among supercontinuum spectra for two fibers which have different properties for chromatic dispersion. We also discuss how nonlinear effects act on the formation of correlations. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 158(3): 55–60, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20435     

Construction of the muscle fatigue evaluation model based on accuracy of power

We have developed a rehabilitation support system that assists exercise training in order to reduce the physical load of therapists. Here, we propose a muscle fatigue evaluation method to decide the appropriate momentum for each patient. Many studies on muscle fatigue by electromyography (EMG) have been reported. However, muscle fatigue evaluation by EMG has the disadvantage of complexity of preparation and it can also give patients mental stress. To solve this problem, we propose muscle fatigue evaluation using an accuracy of muscle power. We verified the proposed method on the abduction/adduction of shoulders. We investigated how the accuracy of muscle power changes repeatedly under abduction/adduction while maintaining a constant power in the tangential direction. From the experimental results, we confirm a correlation between the increase in the amplitude of the EMG and an increase in power in the normal direction by a shift in the direction of power from the tangential direction, i.e., the target direction as the muscle fatigue increases.     

Development of a Peristaltic Crawling Robot Using Planar Link Mechanisms

The field of bio‐mechanisms, which develops new machines that use motion and control of organisms as a model, is attracting attention. We examined the peristaltic crawling of an earthworm as a transport function in place of wheels or ambulation, and have developed a robot running inside a tube. In this robot, a joint corresponding to the earthworm's segment is driven by a DC motor. This paper presents the experimental result of the peristaltic crawling of an actual earthworm and the evaluation result of the transport mechanism of a prototype robot. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Localization of D-��-Aspartyl Residue-Containing Proteins in Various Tissues

Prior to the emergence of life, it is believed that only l-amino acids were selected for formation of protein and that d-amino acids were eliminated on the primitive Earth. Whilst homochirality is essential for life, the occurrence of proteins containing d-β-aspartyl (Asp) residues in various tissues from elderly subjects has been reported recently. Here, we demonstrate the presence of a d-β-Asp-containing protein in the cardiac muscle of heart, blood vessels of the lung, chief cells of the stomach, longitudinal and circular muscle of the stomach, small intestine and large intestine. Since the d-β-Asp residue occurs through a succinimide intermediate, this isomer may potentially be generated in proteins more easily than initially thought. Formation of the d-β-Asp residue in proteins may be related to stress.     

Antioxidant Activity of Phenolic Compounds from Fava Bean Sprouts

Fava beans are eaten all over the world and recently, marketing for their sprouts began in Japan. Fava bean sprouts contain more polyphenols and l ‐3,4‐dihydroxyphenylalanine (l ‐DOPA) than the bean itself. Our antioxidant screening program has shown that fava bean sprouts also possess a higher antioxidant activity than other commercially available sprouts and mature beans. However, the individual constituents of fava bean sprouts are not entirely known. In the present study, we investigated the phenolic compounds of fava bean sprouts and their antioxidant activity. Air‐dried fava bean sprouts were treated with 80% methanol and the extract was partitioned in water with chloroform and ethyl acetate. HPLC analysis had shown that the ethyl acetate‐soluble parts contained phenolic compounds, separated by preparative HPLC to yield 5 compounds ( 1 ? 5 ). Structural analysis using NMR and MS revealed that the compounds isolated were kaempferol glycosides. All isolated compounds had an α‐rhamnose at the C‐7 position with different sugars attached at the C‐3 position. Compounds 1 ? 5 had β‐galactose, β‐glucose, α‐rhamnose, 6‐acetyl‐β‐galactose and 6‐acetyl‐β‐glucose, respectively, at the C‐3 position. The amount of l ‐DOPA in fava bean sprouts was determined by the quantitative ¹H NMR technique. The l ‐DOPA content was 550.45 mg ± 11.34 /100 g of the raw sprouts. The antioxidant activities of compounds 2 ? 5 and l ‐DOPA were evaluated using the 2,2‐diphenyl‐1‐picrylhydrazyl scavenging assay. l ‐DOPA showed high antioxidant activity, but the isolated kaempferol glycosides showed weak activity. Therefore, it can be suggested that l ‐DOPA contributed to the antioxidant activity of fava bean sprouts.     

Enrichment of carotenoids in flaxseed (Linum usitatissimum) by metabolic engineering with introduction of bacterial phytoene synthase gene crtB

Linseed flax (Linum usitatissimum L.) is an industrially important oil crop, which includes large amounts of alpha-linolenic acid (18:3) and lignan in its seed oil. We report here the metabolic engineering of flax plants to increase carotenoid amount in seeds. Agrobacterium-mediated transformation of flax was performed to express the phytoene synthase gene (crtB) derived from the soil bacterium Pantoea ananatis (formerly called Erwinia uredovora 20D3) under the control of the cauliflower mosaic virus (CaMV) 35S constitutive promoter or the Arabidopsis thaliana fatty acid elongase 1 gene (FAE1) seed-specific promoter. As a result, eight transgenic flax plants were generated. They formed orange seeds (embryos), in which phytoene, alpha-carotene, and beta-carotene were newly accumulated in addition to increased amounts of lutein, while untransformed flax plants formed light-yellow seeds, in which only lutein was detected. Interestingly, despite the control of the CaMV 35S promoter, the expression of crtB was not observed in the leaves but in the seeds in the transgenic flax plants. Total carotenoid amounts in these seeds were 65.4-156.3 microg/g fresh weight, which corresponded to 7.8- to 18.6-fold increase, compared with those of untransformed controls. These results suggest that the flux of phytoene synthesis from geranylgeranyl diphosphate was first promoted by the expressed crtB gene product (CrtB), and then phytoene was consecutively decomposed to the downstream metabolites alpha-carotene, beta-carotene, and lutein, as catalyzed by endogenous carotenoid biosynthetic enzymes in seeds. The transgenic flaxseeds enriched with the carotenoids could be valuable as nutritional sources for human health.     

Selective heat-transfer dye diffusion technique using laser irradiation for polymer electroluminescent devices

The heat-transfer process described in this paper will be useful for controllably and selectively doping polymer films used to make hyperfine full-color polymer electroluminescent (EL) displays. A polymer receiver film is placed in direct contact with a dye-dispersed polymer film coated onto an efficient photo-absorbing substrate to permit heat-transfer dye diffusion. The widely used heat-mode magneto-optical storage material, TbFeCo was used as the photo-absorbing material. We irradiated it with a laser in order to generate heat. This method can be used to control the lateral and vertical dopant distributions in polymer films for EL devices. We demonstrated that coumarin 6 and Nile red can be doped into the rather thermally stable polymer poly(N-vinylcarbazole) containing the electron-transporting 2-(4-biphenylyl)-5-(4-tert-butyl-phenyl)-1,3,4-oxadiazole from a viewpoint of luminescent properties. The diffusion power and time for about 1-mm² doping area were 1.2 W and about 10 s.     

Crystal and defect structures of La2/3 xLi3xTiO3 (x ~ 0.1) produced by a melt process

The crystal and defect structures of coarse-grained crystals of La(2/3-x)Li(3x)TiO3 grown from the melt by the Tammann-St?ber method were studied by transmission electron microscopy and powder X-ray diffraction. The as-grown crystals of La(2/3-x)Li(3x)TiO3 have a Li-poor composition of La(0.57)Li(0.29)TiO3 and a diagonal-type unit cell of 2(1/2)a(p) x 2(1/2)a(p) x 2a(p) with the tetragonal symmetry [space group: P4/nbm (#125)] due to both the La-cation ordering and the tilting of TiO6 octahedra. The secondary La2Ti2O7 phase precipitates in the form of plates in the La(2/3-x)Li(3x)TiO3 phase with the orientation relationships of 001(p)//[100](La2Ti2O7) and {110}(p)//(001)(La2Ti2O7), which may cause detrimental effects to ionic conductivity.