Antioxidant activity of black currant anthocyanin aglycons and their glycosides measured by chemiluminescence in a neutral pH region and in human plasma

The antioxidant activity of nine anthocyanin glycosides was measured in a neutral pH region using a chemiluminescence (CL) emission system in the presence of an H(2)O(2)-acetaldehyde system, and the intensities were found to be affected by three factors, pH value and both moieties of the aglycon and C-3 sugar. With an increase in pH from 4.0 to 9.0, the CL intensities increased from pH 5.0, reached their maxima at pH 6.0-7.0, and decreased at pH 9.0. Comparison of the intensities among the 3-glucosides with five different aglycons and the 3-glycosides with three different sugar moieties at C-3 showed that their strongest intensities were given by the delphinidin aglycon and 3-rutinosyl moiety, respectively. Monitoring of the CL intensity of human blood plasma for 8 h after oral administration of black currant anthocyanins (BCA) showed a rapid increase until 2 h, and a significant difference (P < 0.05) was recognized at 1-8 h.     

Parguerol and Isoparguerol Isolated from the Sea Hare,Aplysia kurodai,Induce Neurite Outgrowth in PC-12 Cells

The extract of the sea hare, Aplysia kurodai, showed neurotrophic activity toward rat pheochromocytoma (PC-12) cells. Bioassay-guided purification afforded two active compounds, which were subsequently identified to be parguerol and isoparguerol by spectroscopic analysis. It was found that both parguerol and isoparguerol induced neurite outgrowth in PC-12 cells at concentrations of 25 and 50 μM, respectively.     

Seasonal changes of nitrate concentrations in baseflow headwaters of coniferous forests in Japan: A significant indicator for N saturation

Understanding the seasonal and regional patterns of nitrogen (N) components in the headwaters of forested watersheds is important for forests management. Here, we investigated the NO₃-N concentration and its seasonal variations in the baseflow headwaters in Japanese coniferous forests with different N saturation status in five regions (i.e., Nagano, Tokyo, Aichi, Kochi and Mie). We found that the ratios of NO₃-N to DON were significantly higher in the N-saturated regions including Nagano (14.1 ± 2.2) and Tokyo (16.5 ± 4.1), compared with the regions, which didn't experience N saturation including Aichi (1.4 ± 0.2), Kochi (5.1 ± 1.8), and Mie (2.2 ± 0.5). In comparison with the regions without experiencing N saturation, the relatively higher NO₃-N concentration, as well as its contrastive variation between growing season and dormant season, was also characteristic of the seasonal NO₃-N concentration in the N-saturated regions. Our findings have indicated that NO₃-N concentration, its seasonal variations, and the ratio of NO₃-N to DON, are the better and applicable indicators for evaluating N saturation status in Japanese coniferous forests.     

Epilepsy-related ligand/receptor complex LGI1 and ADAM22 regulate synaptic transmission

Abnormally synchronized synaptic transmission in the brain causes epilepsy. Most inherited forms of epilepsy result from mutations in ion channels. However, one form of epilepsy, autosomal dominant partial epilepsy with auditory features (ADPEAF), is characterized by mutations in a secreted neuronal protein, LGI1. We show that ADAM22, a transmembrane protein that when mutated itself causes seizure, serves as a receptor for LGI1. LGI1 enhances AMPA receptor-mediated synaptic transmission in hippocampal slices. The mutated form of LGI1 fails to bind to ADAM22. ADAM22 is anchored to the postsynaptic density by cytoskeletal scaffolds containing stargazin. These studies in rat brain indicate possible avenues for understanding human epilepsy.     

Effect of plant density on growth and yield of new soybean genotypes grown under early planting condition in southwestern Japan

Soybeans planted in early to mid-June (early) are less affected by rainfall during rainy season than those conventionally planted in early to mid-July in southwestern Japan. Also, narrow row cultivation is expected to increase soybean yield and save labor for inter-tillage and ridging. Field experiments were performed in 2014 and 2015 to test the effect of plant density (high, middle, and low) under early planting condition on growth, yield, and several agronomical traits of Sachiyutaka A1 and three new genotypes (Sakukei 155, Kanto 127 and Shikoku 15). Early planting was performed in mid- to late June, even though rainy season started in early June. Higher plant densities produced 13% greater yield than low plant density through an increase in biomass accumulation, especially at R5. Among yield components, only pods m^?2 was significantly and positively correlated with yield, indicating that an increase in pods m^?2 led to a greater yield with higher plant densities. The yields of Sachiyutaka A1 were relatively stable for two years, but the lodging resistance should be further improved. Shikoku 15 had greater yield potential and lodging resistance, but its resistance to damping-off disease should be improved. Sakukei 155 with medium plant density produced relatively high and stable yield with less lodging. Although the yield of Kanto 127 fluctuated between experimental years, this genotype showed higher yield potential in higher plant densities with less lodging in 2015. Thus, Sakukei 155 and Kanto 127 with high or medium density may be suitable for early planting in this region.     

Relationship between crack propagation and the stress intensity factor in cutting parallel to the grain of hinoki (<Emphasis Type="Italic">Chamaecyparis obtusa</Emphasis>)

The method of digital image correlation (DIC) was applied to the digital image of orthogonal cutting parallel to the grain of hinoki, and the strain distribution near the cutting edge was evaluated. The wood fracture associated with chip generation was considered as mode I fracture, and the stress intensity factor K_I for fracture mode I was calculated from the strain distribution according to the theory of linear elastic fracture mechanics for the anisotropic material. The calculated K_I increased prior to crack propagation and decreased just after the crack propagation. The change in K_I before and after crack propagation, ΔK_I, decreased in accordance with the crack propagation length, although the variance in ΔK_I should depend on the relationships between the resolution of DIC method and the dimensions of cellular structure. The calculated K_I in this study was almost on the same order as reported in the literatures. It was also revealed, for the case of chip generation Type 0 or I, the stress intensity factor for fracture mode II could be negligible due to the higher longitudinal elastic properties of wood in the tool feed direction than the one radial ones, and the mode I fracture was dominant.     

Wood structure of <Emphasis Type="Italic">Populus alba</Emphasis> formed in a shortened annual cycle system

Wood formation of trees that grow along the seasons has an annual rhythm. Due to this rhythm, physiological research on the mechanism of wood formation has been difficult to conduct in a typical experimental room. In the present study, we observed the wood tissue formation in a shortened annual cycle system, which was developed for poplar trees grown in a growth chamber with dormant and non-dormant cycles. Poplar trees were grown in this system by repeating the cycle three times. The resulting wood tissue consisted of three growth rings and very similar structures were observed around the ring boundary of the wood in a field-grown stem. This result suggests that the shortened annual cycle system can be adopted as a model for physiological, cell biological and molecular research of wood and annual ring formation.     

The effect of temperature on environmental DNA degradation of Japanese eel

Fisheries Science - The environmental DNA (eDNA) technique is a convenient and powerful tool to detect rare species. Knowledge of the degradation rate of eDNA in water is important for...     

Expression of podoplanin in various types of feline tumor tissues

Podoplanin is expressed in various human tumors where it promotes tumor progression, epithelial-mesenchymal transition, and distant metastasis. Podoplanin is also expressed in cancer-associated fibroblasts and induces tumor malignancy. The objective of this study was to evaluate podoplanin expression in various types of feline tumor tissues. Immunohistochemical analysis revealed that podoplanin was expressed in cells of 13/15 (87%) squamous cell carcinomas and 5/19 (26%) fibrosarcomas. Moreover, cancer-associated fibroblasts expressed podoplanin in most tumor types, including 18/21 (86%) mammary adenocarcinoma tissues. Our findings demonstrate that various types of feline tumor tissues expressed podoplanin, indicating the importance of the comparative aspects of podoplanin expression, which may be used as a novel research model for podoplanin biology.     

Seroprevalence of antibodies against severe acute respiratory coronavirus 2 (SARS-CoV-2) in household dogs in Japan

We investigated the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among dogs in the Tokyo area via enzyme-linked immunosorbent assay (ELISA) using the spike protein as the target antigen. Plasma samples from 494 household dogs and blood-donor dogs were tested from July 2020 to January 2021. Of these samples, three showed optical densities that were higher than the mean plus two standard deviations of the mean of the negative-control optical densities (ODs). Of these three samples, only the sample with the highest OD by ELISA was confirmed positive by virus neutralization testing. The positive dog presented no SARS-CoV-2-related symptoms. The positivity rate of SARS-CoV-2 infections among dogs in the Tokyo area was approximately 0.2%.