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排序方式: 共有350条查询结果,搜索用时 31 毫秒
1.
Polysaccharide-induced protection of carp, Cyprinus carpio L., against bacterial infection 总被引:5,自引:0,他引:5
Abstract. The efficacy of 10 polysaccharides (curdlan, inulin, krestin, laminaran, lentinan, levan, schizophylian, selerogiucan, yeast glucan and zymosan) to enhance protection of carp, Cyprinus carpio L., against bacterial infection was investigated. Carp were intraperitoneally injected with the polysaceharides (2–l0 mgkg-1 ) on days 1 and 4, and challenged with Edwardsiella tarda on day 7. Among the polysaccharides tested, lentinan, schizophyllan and scleroglucan, which are l,6-branchcd-β-l,3-glucans, significantly increased the survival rate. They also induced a protective effect against Aeromonas hydrophila at a dose of 5 mg kg-1 . The ability of the polysaccharides to activate the alternative complement pathway (ACP) was examined by incubating the polysaccharides with carp serum and measuring the residual ACP activity. At a final concentration of 0.l mgml-1 , l,6-branched-β-1,3-glucans greatly reduced (76–77%) the ACP activity. Therefore, it is suggested that the protective effect of the l,6-branched-β-1,3-glucans may be associated with the activation of ACP. 相似文献
2.
HIROFUMI YAMAGUCHI AYA UTANO KENTARO YASUDA † AZUSA YANO AKIKO SOEJIMA 《Weed Biology and Management》2005,5(4):210-218
The phylogenetic relationship among 30 accessions belonging to nine species of the genus Echinochloa Beauv. was studied on the basis of the sequence of three non-coding regions ( trn T-L, trn L-F intergenic spacers, and trn L intron) of chloroplast DNA (cpDNA). A strict consensus parsimonious tree of the three most parsimonious trees derived from 25 polymorphic sites (six indels and 19 substitutions) in the total sequences, ranging from 1715–1760 bp, represented five groups: (i) Echinochloa oryzicola Vasing. and Echinochloa stagnina Beauv. from Thailand; (ii) Echinochloa crus-galli Beauv. complex; (iii) Echinochloa crus-pavonis Schult; (iv) Echinochloa colonum Link. and Echinochloa frumentacea Link.; and (v) the African species, Echinochloa obtusiflora Stapf and Echinochloa stagnina . Japanese barnyard millet ( Echinochloa esculenta H. Scholz) and various weedy varieties of E. crus-galli and Echinochloa oryzoides Fritsch had quite similar sequences and formed the E. crus-galli complex, which was characterized by six substitutions. A cultivated form of E. oryzicola (Mosuo barnyard millet) and various morphological and agronomical forms of E. oryzicola were characterized by two indels. Indian barnyard millet ( E. frumentacea ) and its wild counterpart ( E. colonum ) were characterized by five substitutions. Domestication as millets and adaptation to paddy environments as mimic weeds might occur after the divergence of species in the Asian Echinochloa . 相似文献
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Noda K Akiyoshi H Aoki M Shimada T Ohashi F 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(4):379-383
Dolphins in a captive environment are exposed to various kinds of stresses. Handling and transportation are stressful events for terrestrial mammals, and such stress may affect immune system function and increase susceptibility to infectious diseases. The same phenomenon could occur in dolphins, however, few studies have reported this in dolphins. The objective of this study was to evaluate the relationship between stress and polymorphonuclear (PMN) cell function of dolphins during transportation. Four bottlenose dolphins (Tursiops truncatus) were transported for 6 hr by truck. Serum cortisol levels, leukograms, phagocytosis, and superoxide production of PMN cells were evaluated during handling and transportation compared to resting values. The mean serum cortisol level was significantly increased during handling and transportation (p<0.05) when compared with the resting values. White blood cell (WBC) counts, eosinophil counts, phagocytosis, and superoxide production of PMN cells during handling and transportation stages decreased significantly in comparison with the resting stage (p<0.05). The concentration of serum cortisol was significantly correlated with the results of the WBC counts, eosinophil counts, superoxide production, and phagocytosis (p<0.01, p<0.05, p<0.05, and p<0.001, respectively). The present results indicate that handling and transportation are stressful events for dolphins and could affect their PMN cell functions, thereby leading to the impairment of the immune system. 相似文献
5.
Okamoto M Urushima H Iwasa M Hasegawa H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(5):545-547
Species of the genus Syphacia are considered to have generally co-evolved with their rodent hosts. This study determined partial sequences of the CO1 gene from several species in the genus Syphacia and discuss the relationships between pinworms and their hosts. Syphacia montana, which parasitizes Microtinae, was closely related to S. frederici and S. obvelata, which parasitize Murinae. Although both S. obvelata and S. ohtaorum parasitize rodents in the genus Mus, these two species were not found to be closely related to each other. Syphacia frederici, S. emileromani and S. agraria are all pinworms of the Apodemus species, but genetic affiliation between these three species was not indicated. These facts suggest that the co-evolutionary relationship between species of the genus Syphacia and their host rodents may not so strict and host switching has probably occurred during the course of evolution. 相似文献
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Establishment of a potency test by ELISA for a rabies vaccine for animal use in Japan 总被引:2,自引:0,他引:2
Gamoh K Shimazaki Y Senda M Makie H Itoh O Muramatsu M Hirayama N Hatakeyama H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(6):685-688
The ELISA we developed was able to determine the antigen content and was suitable for a potency test, and we described a relative potency assay method which determines the potency of test vaccines by comparing the ELISA value of a test vaccine to that of a reference vaccine. In the present study, we standardized the reference vaccine used for determining the potencies of test vaccines, and established a potency test by ELISA. We evaluated the proposed reference vaccine by the neutralizing antibody responses in dogs after vaccination, by the challenge protection test in guinea pigs (GP potency test), which is the earlier official potency test used in Japan, and by the NIH potency test, which is widely used throughout the world. The results showed that a 4-fold dilution of the proposed reference vaccine induced sufficient immunity in dogs. A 3-fold dilution of the proposed reference vaccine passed the GP potency test. The international units (IU) calibrated by the NIH potency test were 3.7 IU/dose. From the results and the WHO recommendation that veterinary rabies vaccines should have a potency of at least 1.0 IU/dose, we determined to dilute the proposed reference vaccine by 3 fold and regarded it as the reference vaccine. Finally, we confirmed that there is a good agreement between the results of the potency test by ELISA and the results of the GP potency test. The establishment of the potency test by ELISA has made it possible to monitor the potency in the production process and has contributed to the stable production of the vaccine. 相似文献
9.
Proliferation and collapse of subcuticular hyphae of Venturia nashicola race 1 were studied ultrastructurally, after inoculation of susceptible Japanese pear cv. Kousui, resistant Japanese pear
cv. Kinchaku, resistant Asian pear strain Mamenashi 12 and nonhost European pear cv. Flemish Beauty leaves, to understand
the nature of the resistance mechanism. After cuticle penetration by the pathogen, the hyphae were observed at lower frequency
in epidermal pectin layers and middle lamellae of leaves of the three resistant plants than in those of susceptible ones.
This result suggested that fungal growth was suppressed in the incompatible interaction between pear and V. nashicola race 1. In the pectin layers of all inoculated plants, some hyphae had modifications such as breaks in the plasmalemma with
plasmolysis, necrotic cytoplasm and degraded cell walls. More hyphae had collapsed in the leaves of the three resistant plants
than in those of the susceptible cv. Kousui. In collapsed hyphae, the polymerized cell walls broke into numerous fibrous and
amorphous pieces, showing that the scab resistance might be associated with cell wall-degrading enzymes from pear plants. 相似文献
10.
Takuyuki Yoshioka Kazuhiro Aruga Toshio Nitami Hiroshi Kobayashi Hideo Sakai 《Journal of Forest Research》2005,10(2):125-134
Using the method of a life cycle inventory (LCI) analysis, the energy balance and the carbon dioxide (CO2) emission of logging residues from Japanese conventional forestry as alternative energy resources were analyzed over the entire life cycle of the residues. The fuel consumption for forestry machines was measured in field experiments for harvesting and transporting logging residues at forestry operating sites in Japan. In addition, a total audit of energy consumption was undertaken. It involved an assessment of materials, construction, and the repair and maintenance of forestry machines as well as the costs associated with an energy-conversion plant. As a result, the ratio of energy output to input was calculated to be 5.69, indicating that the system examined in this study could be feasible as an energy production system. The CO2 emission per MWhe (e: electricity) of the biomass-fired power generation plant was calculated to be 61.8kgCO2/MWhe, while that of coal-fired power generation plants in Japan is 960kgCO2/MWhe. Therefore, the reduction in the amount of CO2 emission that would result from replacing coal with biomass for power generation by as much as 3.0 million dry-t/year of logging residues in Japan was estimated to be 1.66 million tCO2/year, corresponding to 0.142% of the national CO2 emission. This study provides evidence that Japan could reduce its domestic CO2 emission by using logging residues as alternative energy resources. 相似文献