Relationship between blood calcium level and ST peak interval of electrocardiographic variables in peripartum Holstein cows

The association between blood calcium levels and electrocardiographic variables was compared in 137 normal parturient and 36 peripartum recumbent Holstein cows to determine whether hypocalcemia in peripartum dairy cows can be rapidly diagnosed using electrocardiograph. Inverse of STc (ST peak interval/SS interval^0.5) and blood ionized calcium or serum calcium concentrations were strongly correlated, and both correlation coefficients were 0.81 (P<0.001). The 95% prediction interval indicated that cows with STc >0.385 ± 0.001 sec are very likely to be hypocalcemic (blood ionized or serum calcium concentrations of <0.9 mmol/l or <7.5 mg/dl, respectively). These findings indicate that hypocalcemia in parturient cows can be non-invasively estimated using the STc.     

Real-time PCR genotyping assay for feline erythrocyte pyruvate kinase deficiency and mutant allele frequency in purebred cats in Japan

Erythrocyte pyruvate kinase (PK) deficiency is an inherited glycolytic erythroenzymopathy caused by mutations of the PKLR gene. A causative mutation of the feline PKLR gene was originally identified in Abyssinian and Somali cats in the U.S.A. In the present study, a TaqMan probe-based real-time PCR genotyping assay was developed and evaluated for rapid genotyping and large-scale screening for this mutation. Furthermore, a genotyping survey was carried out in a population of four popular purebred cats in Japan to determine the current mutant allele frequency. The assay clearly displayed all genotypes of feline PK deficiency, indicating its suitability for large-scale survey as well as diagnosis. The survey demonstrated that the mutant allele frequency in Abyssinian and Somali cats was high enough to warrant measures to control and prevent the disease. The mutant allele frequency was relatively low in Bengal and American Shorthair cats; however, the testing should still be carried out to prevent the spread of the disease. In addition, PK deficiency should always be considered in the differential diagnosis of anemia in purebred cats in Japan as well as worldwide.     

Cross-sectional cutting of bamboo with a pair of shearing blades for bamboo cube production

As a new use of bamboo, bamboo cubes may be useful as a shot-blast material for surface treatments. However, a suitable processing technique for bamboo cubes has not been established. In this study, to obtain basic knowledge regarding the processing technology for bamboo cubes, we installed shearing blades (upper and lower blades) in a universal testing machine to test cross-sectional shearing of bamboo. The shearing force generated in this shearing was composed of a vertical component (F _v), a forward component (F _f), and a side component (F _s). This shearing force (F _v, F _f, and F _s) and the machining accuracy were investigated under various processing conditions. The shearing force became larger as the thickness of bamboo increased. In particular, F _v showed a tendency to increase rapidly. Changes in the shear angle of the upper blade had a remarkable influence on F _v. This result suggests that the shearing force could be greatly decreased by adjusting the shear angle. The shearing force within bamboo of 3mm in thickness was almost unaffected by the blade angle, and the change of shearing force with increasing clearance was almost indiscernible. It was clearly demonstrated that a large number of bamboo cubes could be made when the shear angle was large and cross-sectional shearing was performed from the bark side. However, a consequence of a large shear angle is that burr area increases. Part of this article was presented at the 53rd Annual Meeting of the Japan Wood Research Society, Fukuoka, March 2003     

First report of trunk rot caused by <Emphasis Type="Italic">Fomitiporia torreyae</Emphasis> in Kyoto prefecture on cultivars of Japanese cedar with no relatedness to ‘Sanbu-sugi’

Trunk rot, caused by Fomitiporia torreyae, is one of the most economically important sap rot diseases on Cryptomeria japonica, especially on a cutting cultivar ‘Sanbu-sugi’. This disease had been reported only from Chiba and Ibaraki prefectures in Japan; however, a similar trunk rot on Japanese cedars was found recently in Kyoto prefecture. We identified the causal agent of the trunk rot on Japanese cedars in Kyoto prefecture, clarified the genotype of ‘Sanbu-sugi’ (sensu stricto) using microsatellite markers, and then investigated the relatedness of these infected cedars with ‘Sanbu-sugi’. The pathogen was identified as F. torreyae by its DNA sequences and morphological characteristics of the fruiting body. The 25 ramets of ‘Sanbu-sugi’ had only one genotype based on eight microsatellite loci. Infected Japanese cedars in Kyoto were comprised of different genotypes and showed no close relatedness to ‘Sanbu-sugi’. This is the first report of trunk rot caused by F. torreyae on cultivars of Japanese cedar with no relatedness to ‘Sanbu-sugi’ outside of Chiba and Ibaraki prefectures and showed the potential for expansion of this disease to Japanese cedar plantations in other areas.     

Amberjack <Emphasis Type="Italic">Seriola dumerili</Emphasis> interleukin-10 negatively suppresses host cell-mediated immunity

Interleukin-10 (IL-10) is an anti-inflammatory cytokine and negatively regulates cell-mediated immunity (CMI) induction by inhibiting cytokine production in type 1 T helper cells. IL-10 genes have been isolated from several fish, and inflammatory cytokine inhibition by IL-10 has been well examined. However, a CMI regulator of IL-10 in fish has not yet been identified. In this study, we cloned the IL-10 gene in amberjack Seriola dumerili and analyzed its function using its recombinant protein (rIL-10). In an in vitro culture experiment, gene expression of inflammatory cytokines was suppressed in leukocytes incubated with rIL-10 compared with cells that only received Nocardia seriolae stimulation. This result suggests amberjack IL-10 has conserved function as an inflammatory cytokine inhibitor. Bactericidal activity of amberjack cells against intracellular pathogen stimulation was decreased in a rIL-10 dose-dependent manner. Furthermore, a significant reduction in the T-bet/GATA-3 ratio was observed in N. seriolae living cell (LC)?+?rIL-10-injected fish. Taken together, these results suggest amberjack rIL-10 suppresses CMI induction both in vitro and in vivo. In addition, the number of IgM⁺ cells among spleen leukocytes in N. seriolae?+?rIL-10-injected fish was higher than in only N. seriolae LC, suggesting that Th2-dominant immunity was induced by adding rIL-10.     

Preparation of Photocrosslinked Fish Elastin Polypeptide/Microfibrillated Cellulose Composite Gels with Elastic Properties for Biomaterial Applications

Photocrosslinked hydrogels reinforced by microfibrillated cellulose (MFC) were prepared from a methacrylate-functionalized fish elastin polypeptide and MFC dispersed in dimethylsulfoxide (DMSO). First, a water-soluble elastin peptide with a molecular weight of ca. 500 g/mol from the fish bulbus arteriosus was polymerized by N,N′-dicyclohexylcarbodiimide (DCC), a condensation reagent, and then modified with 2-isocyanatoethyl methacrylate (MOI) to yield a photocrosslinkable fish elastin polypeptide. The product was dissolved in DMSO and irradiated with UV light in the presence of a radical photoinitiator. We obtained hydrogels successfully by substitution of DMSO with water. The composite gel with MFC was prepared by UV irradiation of the photocrosslinkable elastin polypeptide mixed with dispersed MFC in DMSO, followed by substitution of DMSO with water. The tensile test of the composite gels revealed that the addition of MFC improved the tensile properties, and the shape of the stress–strain curve of the composite gel became more similar to the typical shape of an elastic material with an increase of MFC content. The rheology measurement showed that the elastic modulus of the composite gel increased with an increase of MFC content. The cell proliferation test on the composite gel showed no toxicity.     

Structure-Activity Relationship Study of the Neuritogenic Potential of the Glycan of Starfish Ganglioside LLG-3

LLG-3 is a ganglioside isolated from the starfish Linchia laevigata. To clarify the structure-activity relationship of the glycan of LLG-3 toward rat pheochromocytoma PC12 cells in the presence of nerve growth factor, a series of mono- to tetrasaccharide glycan derivatives were chemically synthesized and evaluated in vitro. The methyl group at C8 of the terminal sialic acid residue was crucial for neuritogenic activity, and the terminal trisaccharide moiety was the minimum active motif. Furthermore, the trisaccharide also stimulated neuritogenesis in human neuroblastoma SH-SY5Y cells via mitogen-activated protein kinase (MAPK) signaling. Phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 was rapidly induced by adding 1 or 10 nM of the trisaccharide. The ratio of phosphorylated ERK to ERK reached a maximum 5 min after stimulation, and then decreased gradually. However, the trisaccharide did not induce significant Akt phosphorylation. These effects were abolished by pretreatment with the MAPK inhibitor U0126, which inhibits enzymes MEK1 and MEK2. In addition, U0126 inhibited the phosphorylation of ERK 1/2 in response to the trisaccharide dose-dependently. Therefore, we concluded that the trisaccharide promotes neurite extension in SH-SY5Y cells via MAPK/ERK signaling, not Akt signaling.     

Effect of nitrogen application at anthesis on Fusarium head blight and mycotoxin accumulation in breadmaking wheat in the western part of Japan

In the western part of Japan, two wheat cultivars, Nishinokaori and Minaminokaori, are currently cultivated for breadmaking. Breadmaking wheat requires a higher protein content compared to the Japanese noodle wheat (the major type of wheat in Japan). This high protein level in the grain is obtained by top-dressing with nitrogen (N) near anthesis. Because such N applications may increase levels of Fusarium head blight (FHB) and consequent mycotoxin [deoxynivalenol (DON) and nivalenol (NIV)] accumulation in the grain, the effect of N application (0, 4, and 8 g/m²) at anthesis on FHB and mycotoxin accumulation in Nishinokaori and Minaminokaori was tested in the greenhouse in 2004 and 2005 and in two fields in 2006. In the greenhouse, plants were spray inoculated at 3, 10, and 20 days after N treatment. In field experiments, colonized maize kernels, which generate ascospores during the testing season, served as inoculum. In all experiments for both cultivars, N application at anthesis significantly increased grain protein as expected, but had no significant effect on FHB and DON and NIV levels in grain. These results suggest that, at least in these cultivars, N can be applied close to anthesis without increasing the risk of FHB and mycotoxin (DON and NIV) accumulation.     

Seasonality of factors controlling N mineralization rates among slope positions and aspects in cool-temperate deciduous natural forests and larch plantations

This study aimed to evaluate the spatial patterns of soil nitrogen (N) transformations in relation to slope aspect and position, and to investigate the main factors controlling N transformation patterns during both the growing and dormant seasons in cool-temperate deciduous natural forests and larch plantations in eastern Hokkaido, northern Japan. Net rates of N mineralization (NR_minN) and of nitrification (NR_nit) in surface soils on north-facing and lower slopes were higher than those on south-facing and upper slopes, whereas the net rate of ammonium-N production (NR_amm) on south-facing and upper slopes was higher than that on north-facing slopes in both the natural forests and larch plantations. Both NR_minN and NR_nit were higher in the growing than in the dormant season, whereas NR_amm was higher in the dormant season. The soil C/N ratio, water content, soil pH and frequency of freeze–thaw cycles were important variables affecting N transformation patterns in any season. In relation to seasonality, the solar radiation index, daily temperature range and earthworm biomass were important controlling factors only during the growing season, and watershed area and soil N concentration only during the dormant season, suggesting that biological control accompanied with wet–dry events were important factors affecting N transformations during the growing season, but that run-off water and chemical controls were important determinants of spatial variation in N transformations during the dormant season.     

Phenotypic and functional analysis of bovine peripheral blood dendritic cells before parturition by a novel purification method

Dendritic cells (DCs) are specialized antigen presenting cells specializing in antigen uptake and processing, and play an important role in the innate and adaptive immune response. A subset of bovine peripheral blood DCs was identified as CD172a⁺/CD11c⁺/MHC (major histocompatibility complex) class II⁺ cells. Although DCs are identified at 0.1%–0.7% of peripheral blood mononuclear cells (PBMC), the phenotype and function of DCs remain poorly understood with regard to maintaining tolerance during the pregnancy. All cattle used in this study were 1 month before parturition. We have established a novel method for the purification of DCs from PBMC using magnetic‐activated cell sorting, and purified the CD172a⁺/CD11c⁺ DCs, with high expression of MHC class II and CD40, at 84.8% purity. There were individual differences in the expressions of CD205 and co‐stimulatory molecules CD80 and CD86 on DCs. There were positive correlations between expression of cytokine and co‐stimulatory molecules in DCs, and the DCs maintained their immune tolerance, evidenced by their low expressions of the co‐stimulatory molecules and cytokine production. These results suggest that before parturition a half of DCs may be immature and tend to maintain tolerance based on the low cytokine production, and the other DCs with high co‐stimulatory molecules may already have the ability of modulating the T‐cell linage.