Competitive enzyme-linked immunosorbent assay for the detection of the antibodies specific to akabane virus.   总被引：5，自引：0，他引：5  

Tomoyuki Tsuda  Kazuo Yoshida  Tohru Yanase  Seiichi Ohashi  Makoto Yamakawa 《Journal of veterinary diagnostic investigation》2004,16(6):571-576

A competitive enzyme-linked immunosorbent assay (C-ELISA) using neutralizing monoclonal antibodies (MAbs) against Akabane virus (AKAV) was developed to detect antibodies to AKAV in cattle sera. The performance of the test using 7 different competitor MAbs was evaluated in sequential serum samples and sera from cattle infected with various bovine arboviruses. The dynamics of the antibody response expressed by percentage of inhibition (PI) in C-ELISA coincided with those of neutralizing antibody titers in sequential serum samples from 2 cattle experimentally infected with AKAV. The value of PI in C-ELISA for convalescent sera from cattle infected with arboviruses correlated with the neutralizing antibody titer to AKAV but was unaffected by the antibodies to other arboviruses. In the validation experiment of C-ELISA using 286 bovine sera previously examined for the AKAV antibody by serum neutralization (SN) test, the relative specificity of C-ELISA was more than 98%, whereas the relative sensitivities of individual MAbs ranged from 49% to 82.2%. Overall agreement between C-ELISA and the SN test varied from 72% to 90% depending on the MAb. These results suggest that the C-ELISA is acceptable as a rapid and specific method for detecting antibodies to AKAV and is a potential alternative to the SN test.  相似文献   

Isolation and chemiluminescent properties of ferret (Mustela putorius furo) polymorphonuclear cells     

Nakata M  Itou T  Sakai T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(12):1321-1324

Ferret polymorphonuclear cells (PMNs) and peripheral blood mononuclear cells (PBMCs) were separated from whole blood by density gradient centrifugation. Using a 50% Percoll solution (density=1.066), PMNs and PBMCs were successfully isolated after centrifugation; the purities of the PMNs and PBMCs were 94.2% and 95.6%, respectively. To evaluate the function of isolated ferret PMNs, we measured the superoxide generation with a MCLA-dependent chemiluminescence assay. The isolated ferret PMNs responded to phorbol 12-myristate 13-acetate (PMA) with kinetics similar to that of human PMNs. The ferret PMNs did not respond to N-formyl-Met-Leu-Phe (fMLF), unlike human PMNs, which rapidly responded. Thus, authors established a method for the rapid separation of highly purified populations of functional PMNs from the whole blood of ferrets.  相似文献   

Phylogenetic characterization of rabies virus isolates from Carnivora in Brazil     

Kobayashi Y  Inoue N  Sato G  Itou T  Santos HP  Brito CJ  Gomes AA  Santos MF  Silva MV  Mota CS  Ito FH  Sakai T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(7):691-696

The incidence of canine rabies has been widely reported in Brazil, and new rabies virus (RV) variants, genetically similar to canine RV, have recently been isolated from foxes. In order to derive the epidemiological characteristics of Brazilian Carnivora RV, Brazilian RVs isolated from dogs, cats, and foxes were genetically analyzed. Brazilian Carnivora RV isolates were divided into 2 main lineages. The predominant lineage was found in dogs and cats, which included the Argentinean and Bolivian Carnivora RV isolates, and was extensively distributed throughout Brazil and surrounding countries. The other lineage consisted of three sublineages containing Brazilian dog and fox RV isolates, with the dog sublineages located on an internal branch of 2 fox sublineages, suggesting that RV transmission events might have occurred between foxes and dogs in the past. These results suggest that contact between dogs and wildlife has the potential to generate new rabies variants and that it is important to control RV infection cycles in both dogs and wildlife to prevent spread of rabies infection.  相似文献   

Bovine milk enhances the oxidative burst activity of polymorphonuclear leukocytes in low concentrations     

Sugisawa H  Itou T  Ichimura Y  Sakai T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(12):1113-1116

Bovine milk contains various immunoreactive components, and the activation of polymorphonuclear leukocytes (PMNLs) function in breast-fed infants has been reported. In this study, the effect of milk on the oxidative burst of bovine PMNLs was investigated in vitro. When PMNLs were incubated with 0.1% colostrum or normal milk, the oxidative burst induced by serum-opsonized Staphylococcus aureus was enhanced, and the enhancement declined dose-dependently. The enhancement of the oxidative burst by milk was not due to opsonins but the priming activities. Also, the phorbol 12-myristate 13-acetate (PMA)-induced oxidative burst increased after incubation with 0.1% colostrum, but the colostral enhancement of the oxidative burst was unaffected by the incubation time. These results suggest that bovine milk contains oxidative burst promoting factor(s).  相似文献   

Preferential infection of neuronal and astroglia cells by Akabane virus in primary cultures of fetal bovine brain   总被引：3，自引：0，他引：3  

Kitani H  Yamakawa M  Ikeda H 《Veterinary microbiology》2000,73(4):269-279

Akabane virus is a member of the genus Bunyavirus; it is pathogenic for ruminants and transmitted by arthropod vectors. Infection of adult cattle and sheep causes a transient viremia without obvious clinical signs, while infection of pregnant animals often causes fetal abnormalities including hydranencephaly, poliomyelitis and arthrogryposis. Infectious virus or viral antigens is present in the brain, spinal cord and skeletal muscle of infected fetuses. To understand the interaction between Akabane virus and bovine brain cells, we investigated the viral tropism using primary cultures of fetal bovine brain. The cultured neuronal cells, astroglia cells and microglia cells were distinguished by cell type specific antisera. Akabane virus was found to infect neuronal cells and astroglia cells, which led to degenerative death. No microglia cells were found infected. In some brain cultures, we observed different sensitivities of the cells to two Akabane virus strains: an attenuated strain infected and spread more readily than wild type virus. This difference was not observed in a hamster fibroblast cell line. Both viral and host determinants might be involved in the different susceptibility of brain cells to Akabane virus infection.  相似文献   

Root parameters of forest trees as sensitive indicators of acidifying pollutants: a review of research of Japanese forest trees     

Yasuhiro Hirano  Takeo Mizoguchi  Ivano Brunner 《Journal of Forest Research》2007,12(2):134-142

The root parameters of forest trees can be indicators of a changing environment. We summarize the results of root studies with regard to the effects of acidifying pollutants, especially soil acidification and aluminum toxicity, on various root parameters of Japanese forest trees under experimentally controlled conditions. All root parameters such as biomass, morphology, nutritional status, and physiology can be regarded as indicators, because, under laboratory conditions, root responses occur prior to the responses in the aboveground parts. However, considering the conditions of forest sites, the nutritional status and physiological changes are better indicators of soil acidification and Al stress than the biomass and morphological response. The currently available data suggest that the most important indicator is the Ca/Al molar ratio in roots of Japanese tree species. In order to predict and detect the initial effects of soil acidification, we postulate that the specific root response to the Ca/Al molar ratio of tree roots should be considered as a parameter for use in long-term forest monitoring sites.  相似文献   

Estimating the production and mortality of fine roots in a Japanese cedar (Cryptomeria japonica D. Don) plantation using a minirhizotron technique     

Kyotaro Noguchi  Tadashi Sakata  Takeo Mizoguchi  Masamichi Takahashi 《Journal of Forest Research》2005,10(6):435-441

Fine roots are a key component of forested ecosystems, but available information is still limited. This study examined the production and mortality of fine roots less than 1 mm in diameter in a Japanese cedar (Cryptomeria japonica D. Don) plantation located on the Kanto Plain in central Japan. We used a minirhizotron technique in combination with soil coring, and collected data for 1 year (May 2002–May 2003). Fine root production and mortality were determined from changes in the lengths of individual fine roots on minirhizotron tubes. Both fine root production and mortality rates were greater in the upper soil than in lower soil levels. Both rates were seasonal, with higher values in summer than in winter; this trend was more pronounced in upper soil levels. These results suggest that environmental conditions, such as temperature or soil properties, affect the production and mortality rates of fine roots. Fine root production and mortality occurred simultaneously, and their rates were similar, which may have led to unclear seasonal changes in fine root standing crop estimates. Soil coring indicated that the fine root biomass of this stand was about 120 g m⁻², of which 40% was from Japanese cedar. The estimated rates of dry matter production and mortality of total fine roots, including understory plants, were both approximately 300 g m⁻² year⁻¹.  相似文献   

Maternal Liver Damage Delays Meiotic Resumption in Bovine Oocytes through Impairment of Signalling Cascades Originated from Low p38MAPK Activity in Cumulus Cells     

H Tanaka  S Takeo  Y Monji  T Kuwayama  H Iwata 《Reproduction in domestic animals》2014,49(1):101-108

The main objective of the present study is to investigate the molecular mechanism underlying the delay in progression of nuclear maturation in oocytes derived from cows with damaged livers (DL cows), which was previously reported. In present study, delayed progression of nuclear maturation of oocytes derived from DL cows relative to oocytes derived from cows with healthy livers (HL cows) was accompanied by low maturation promoting factor (MPF) activity (0.43 fold, p < 0.05). When cumulus cells were removed from cumulus‐oocyte complexes and the denuded oocytes were cultured, there was no difference in the progression of nuclear maturation between the two liver conditions. In addition, gap junctional communication (GJC) between the oocyte and cumulus cells was higher in DL cows than in HL cows at 3 and 7 h of in vitro maturation (IVM) (p < 0.05). Supplementation of IVM medium with epidermal growth factor (EGF) increased the ratio of germinal vesicle breakdown (GVBD) of oocytes derived from DL cows to the level seen in oocytes derived from HL cows. Additionally, the level of p38MAPK phosphorylation at 0 h of IVM was significantly lower in cumulus cells derived from DL cows than in cumulus cells derived from HL cows (HL cows, 53.5%; DL cows, 28.9%; p < 0.05). Thus, a low level of p38MAPK phosphorylation in cumulus cells induced slow GJC closure between oocyte and cumulus cells, which resulted in slow meiotic maturation of oocytes derived from DL cows.  相似文献   

Age estimation of the wild population of Japanese mantis shrimp <Emphasis Type="Italic">Oratosquilla oratoria</Emphasis> (Crustacea: Stomatopoda) in Tokyo Bay,Japan, using lipofuscin as an age marker     

Keita?KodamaEmail author  Takashi?Yamakawa  Takamichi?Shimizu  Ichiro?Aoki 《Fisheries Science》2005,71(1):141-150

ABSTRACT:   In this study, the age composition of the Japanese mantis shrimp, Oratosquilla oratoria , in Tokyo Bay, central Japan, was investigated using lipofuscin, an autofluorescent pigment, as an age marker. Lipofuscin in a histological section of protocerebral bridge cell mass (PBCM) in the brain was identified by confocal microscopy, and its concentration was quantified by image analysis. Modal analysis of the lipofuscin concentration showed four regularly-spaced modes that could each be regarded as a distinct age group. This implied a constant lipofuscin accumulation in PBCM at a 6.5 × 10⁻²% volume fraction per year; it also implied the existence of individuals that are at least 4 years old. The lipofuscin concentration was found to be a more appropriate index than body length for estimating the age of O. oratoria , because the modal analysis on the body–length histogram failed to detect apparent age groups. This was probably a result of the declining growth rate with age and the individual variations in growth through molting leading to considerable overlap in the size between different age groups. The lipofuscin analysis suggested that fast-growing individuals in each cohort are recruited to the fishery, and most individuals attain the exploitable size between 2 and 3 years of age.  相似文献   

Identification and characterization of foliar polyphenolic composition in sweetpotato (Ipomoea batatas L.) genotypes   总被引：1，自引：0，他引：1  

Islam MS  Yoshimoto M  Yahara S  Okuno S  Ishiguro K  Yamakawa O 《Journal of agricultural and food chemistry》2002,50(13):3718-3722

Trials over two years were conducted using 1389 sweetpotato (Ipomoea batatas L.) genotypes collected from all over the world to characterize the polyphenolic composition in sweetpotato leaves. Wide variation was observed in relation to their total and individual leaf polyphenolic constituents. In all genotypes studied, the total polyphenol contents of sweetpotato leaf ranged from 1.42 to 17.1 g/100 g dry weight. The six different polyphenolic compounds were identified and quantified by NMR, FABMS, and RPHPLC analysis procedures. This is the first report of polyphenolic compositions in sweetpotato leaves. The relative levels of polyphenolic acids in sweetpotato leaves were as follows: 3,5-di-O-caffeoylquinic acid > 4,5-di-O-caffeoylquinic acid > chlorogenic acid (3-O-caffeoylquinic acid) > 3,4-di-O-caffeoylquinic acid > 3,4,5-tri-O-caffeoylquinic acid > caffeic acid. The highest 3,4,5-tri-O-caffeoylquinic acid and 4,5-di-O-caffeoylquinic acid occurred at 221 and 1183.30 mg/100 g dry weight, respectively.  相似文献