CoCl(2) inhibits neural differentiation of retinoic acid-treated embryoid bodies

The effects of CoCl(2) on retinoic acid (RA)-treated embryoid bodies (EBs) were investigated. Four-day EBs were treated with 5x10(-6) M of RA for 4 d, then subjected to attached culturing for 7 d in the presence of CoCl(2) at 0, 20, and 100 microM. Differentiation into MAP2- and GFAP-immunopositive cells was inhibited by CoCl(2) in a dose-dependent manner. Next, RA-treated EBs were dissociated into single cells and cultured for 7 d at an initial cell density of 1x10(3)/cm(2). The number of cells increased in a CoCl(2)-dose dependent fashion. In cultures with 100 microM of CoCl(2), more than 90% of the cells were immunopositive for nestin and nestin-immunopositive cells formed clusters, while there were few cells immunopositive for MAP2 or GFAP. These results suggest that CoCl(2) inhibits neural differentiation of RA-treated EB cells and promotes the proliferation of nestin-immunopositive cells, i.e., embryonic stem (ES)-derived neural stem-like cells.     

Shear properties of metal-free wooden load-bearing walls using plywood jointed with a combination of adhesive tape and wood dowels

In this study, the potential of wood-only (metal-free) load-bearing walls was proposed and tested based on the idea of using the same type of material throughout wherever possible while improving basic properties such as strength, sound insulation, and heat insulation. Specifically, a technique was tested of combining pressure sensitive adhesive tape and wood dowels in place of nails for load-bearing structures with panel reinforcement represented by wood-frame construction. For this paper, its strength was evaluated by conducting in-plane shear tests, which revealed that the initial rigidity and maximum load of the proposed test specimens were greater than that of specimens using nails for jointing. However, the shear load factor, which is calculated based on some strength parameters and which forms the foundation of housing strength design, was slightly lower than that of the nail-jointed specimen. This was because there was a large decline in post-collapse resistance and a lower calculated absorbed energy caused by brittleness. The early detachment of panels was also revealed as a problem in the tests.     

Transfer of high-mannose-type oligosaccharides to disaccharides by endo-beta-N-acetylglucosaminidase from Arthrobacter protophormiae

Endo-beta-N-acetylglucosaminidase from Arthrobacter protophormiae (Endo-A) has transglycosylation activity, and high-mannose-type oligosaccharides are transferred to suitable glycosides as acceptor substrates. The acceptor specificity of Endo-A-catalyzed transglycosylation toward various disaccharides was investigated. To identify an effective acceptor for the transglycosylation by Endo-A, the reaction was carried out using various disaccharides. Endo-A transferred high-mannose-type oligosaccharides more efficiently to beta-linked disaccharides (cellobiose, gentiobiose, sophorose, and laminaribiose) than to alpha-linked disaccharides (isomaltose, maltose, nigerose, kojibiose, and trehalose) as acceptor substrates. The transglycosylation products, (Man)6GlcNAc-Glc-beta-Glc, were more rapidly hydrolyzed than (Man)6GlcNAc-Glc-alpha-Glc. These results indicate that Endo-A recognizes the anomeric configuration of the acceptor substrates, and beta-linked glycosides are suitable for the synthesis of transglycosylation products.     

Atmospheric outflow of anthropogenic semivolatile organic compounds from East Asia in spring 2004

To estimate the emissions of anthropogenic semivolatile organic compounds (SOCs) from East Asia and to identify unique SOC molecular markers in Asian air masses, high-volume air samples were collected on the island of Okinawa, Japan between 22 March and 2 May 2004. Contributions from different source regions (China, Japan, the Koreas, Russia, and ocean/local) were estimated by use of source region impact factors (SRIFs). Elevated concentrations of hexachlorobenzene (HCB), hexachlorcyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), and particulate-phase polycyclic aromatic hydrocarbons (PAHs) were attributed to air masses from China. A large proportion of the variation in the current-use pesticides, gas-phase PAHs, and polychlorinated biphenyl (PCB) concentrations was explained by meteorology. Chlordanes showed a technical mixture profile and similar concentrations regardless of source region. alpha/gamma HCH and trans/cis chlordane ratios did not vary significantly with different source regions and had regional averages of 2.5 +/- 1.0 and 1.2 +/- 0.3, respectively. Particulate-phase PAH concentrations were significantly correlated (p value < 0.05) with other incomplete combustion byproduct concentrations, including elemental mercury (Hg0), CO, NOx, black carbon, submicrometer aerosols, and SO2. By use of measured PAH, CO, and black carbon concentrations and estimated CO and black carbon emission inventories, the emission of six carcinogenic particulate-phase PAHs was estimated to be 1518-4179 metric tons/year for Asia and 778-1728 metric tons/year for China, respectively. These results confirm that East Asian outflow contains significant emissions of carcinogenic particulate-phase PAHs.     

Preparation and Intestinal Immunostimulating Activity of Low Molecular Weight Alginate from Saccharina (Laminaria) Species in Japan

We studied the structure of alginates extracted from five commercial Saccharina (Laminaria) species including three varieties (eight samples in all) harvested in Hokkaido, Japan. The algae used were Saccharina japonica, S. japonica var. diabolica, S. japonica var. ochotensis, S. japonica var. religiosa, S. longissima, S. coriacea, S. angustata, and S. sculpera (Kjellmaniella crassiforia). These alginates have molar fractions of mannuronic acid (F_M) ranging from 0.68 to 0.76 and weight average molecular weights (M_ws) ranging from 511,000 to 616,000. Alginate samples from both S. angustata (F_M = 0.76) and S. longissima (F_M = 0.68) showed intestinal immunological activity through Peyer’s patch cells of C3H/HeJ mice. Low molecular weight S. angustata alginate (F_M = 0.75, M_w = 70,000) degraded using a wet pulverizing system showed higher activity than the native one.     

Effects of processing and cooking on the levels of pesticide residues in soybean samples

The effects of processing and cooking on the levels of pesticide residues in soybean samples were investigated for 14 pesticides in pre-harvest samples. On soaking, the transfer ratios (%, total pesticide residue amount in product/that in soybean) of soaked soybean were greater than 60% for most of the pesticides investigated. The transfer ratio of soymilk ranged from 37% to 92%, and that of tofu ranged from 7% to 63%. The processing factor (Pf, the concentration (mg/kg) of pesticide in product/that in soybean) of tofu ranged from 0.026 to 0.28. These values varied among pesticides. There was a high correlation between the log P(ow) and the transfer ratio of tofu. The test described here should be useful to obtain the transfer ratios of pesticide residues in processing and/or cooking steps.     

A motif detection and classification method for peptide sequences using genetic programming

An exploration of common rules (property motifs) in amino acid sequences has been required for the design of novel sequences and elucidation of the interactions between molecules controlled by the structural or physical environment. In the present study, we developed a new method to search property motifs that are common in peptide sequence data. Our method comprises the following two characteristics: (i) the automatic determination of the position and length of common property motifs by calculating the physicochemical similarity of amino acids, and (ii) the quick and effective exploration of motif candidates that discriminates the positives and negatives by the introduction of genetic programming (GP). Our method was evaluated by two types of model data sets. First, the intentionally buried property motifs were searched in the artificially derived peptide data containing intentionally buried property motifs. As a result, the expected property motifs were correctly extracted by our algorithm. Second, the peptide data that interact with MHC class II molecules were analyzed as one of the models of biologically active peptides with buried motifs in various lengths. Twofold MHC class II binding peptides were identified with the rule using our method, compared to the existing scoring matrix method. In conclusion, our GP based motif searching approach enabled to obtain knowledge of functional aspects of the peptides without any prior knowledge.