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101.
Since 1993, an epizootic viral disease has occurred in net-cage cultured red sea bream, Pagrus major (Temminck & Schlegel), in Peng-hu Island located on the south-western coast of Taiwan. The diseased fish exhibited abnormal swimming and were lethargic, but few visible external signs were observed. The cumulative mortality because of the disease sometimes reached 50-90% over 2 months. Histopathogical studies of the affected fish showed enlarged basophilic cells in the gill, kidney, heart, liver and spleen. These necrotic cells were Feulgen-positive and stained blue using Giemsa. Transmission electron microscopy revealed icosahedral virions in the cytoplasm of the necrotic cells. The viral particles consisted of a central nucleocapsid (75-80 nm) and envelope, and were 120-150 nm in diameter. These results suggest that the virus belongs to the Iridoviridae. Using polymerase chain reaction (PCR), approximately 570 bp fragments were produced from the viral DNA using as a template 1-F and 1-R primers derived from red seabream iridovirus (RSIV) from red sea bream in Japan. Similar results were also obtained using nested-PCR with different primer sets (1-F, 2-R and 2-F, 1-R). Although the size and some features of epizootics of this virus differed from RSIV in Japan, it shows close genetic affinities with the latter and it is suggested that RSIV has been introduced to Taiwan. 相似文献
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Sesame seeds (Sesamum indicum L.) are unique because of potent and various physiological activities imparted by their bioactive lignans. This investigation studied the intestinal distribution and excretion of sesaminol in Sprague-Dawley (SD) rats. To investigate the distribution of sesaminol (per oral 220 mg/kg), the changes in concentration of sesaminol and its metabolites were determined in the intestines and plasma within the 24 h period after tube feeding of sesaminol to SD rats. Results show that the epimerization of sesaminol appeared to be catalyzed by acid in the simulated gastric fluids. The major sesaminol epimer was characterized as 2-episesaminol using 2D-NMR. These findings indicate that sesame sesaminol and its epimer are poorly absorbed prior to reaching the rectum and that substantial amounts pass from the small to the large intestine, where they are metabolized by the colonic microflora to tetrahydrofuranoid metabolites. Sesaminol in plasma was largely present as phase II conjugates, and the seven metabolites were detected as the 2-episesaminol, sesaminol-6-catechol, methylated sesaminol-catechol, R,R-hydroxymethylsesaminol-tetrahydrofuran, S,R-hydroxymethylsesaminol-tetrahydrofuran, enterolactone, and enterodiol. Excretions of sesaminol in urine and feces within the 24 h period were equivalent to 0.02 and 9.33% of the amount ingested, respectively. 相似文献
105.
Fifteen species of Palearctic and Holarctic Rhagidiidae inhabit the polar Fennoscandian mountain birch forest and tundra, but additional taxa are expected to be discovered. Their assemblages comprise 5–10 species. Of these, Rhagidia gigas, R. diversicolor and Poecilophysis pratensis are the most abundant and widely distributed in the forested subalpine (480–600 m a.s.l.) and transitional (500–650 m a.s.l.) altitudinal zones while Poecilophysis pseudoreflexa and Rhagidia longiseta are found in the low-(600–800 m a.s.l.) and mid-(800–960 m a.s.l.), and Rhagidia parvilobata in the high alpine (960–1025 m a.s.l.) zones. Ten species of the rhagidiid mites are common in the Fennoscandian tundra as well as the alpine tundra of the Ötztal Alps, North Tyrol. Patterns of richness and diversity in this group of mites are different in different altitudinal zones in NW Lapland and the Ötztal Alps. In contrast to the Alps, no endemic species were detected in Fennoscandia. The different altitudinal niches of most common mite species overlap, but some species of mites in the subalpine forest and the high alpine zone are altitudinal vegetation belt-specific and occupy different niches. Some species of mites are rare in all altitudinal vegetation belts.Rhagidia diversicolor, R. gigas, Poecilophysis pratensis and P. pseudoreflexa exhibited sufficient abundance, habitat and elevational specificity to be useful as indicator species of the subalpine to transitional as well as the low alpine to middle alpine altitudinal zones, respectively. Rhagidia parvilobata and Poecilophysis saxonica are indicators of the high alpine zone. Abundant species from the low subalpine forested zone as well as the high alpine zone are proposed as potential monitors for direct and indirect impact of climate warming. Summit mite invaders detecting current impact of climate warming were not discovered in the high alpine zone of the Fennoscandian oroboreal tundra. 相似文献
106.
A seroprevalence study of bovine immunodeficiency virus (BIV) was undertaken on 1,541 serum samples from Holstein cattle from 23 herds, located in different geographical regions of Poland. The analysis was performed using ELISA, with recombinant Gag protein of BIV as antigen. The average BIV prevalence was 4.9% in individual cattle, while the percentage of herds harboring at least one seropositive animal, was 82.6%. To demonstrate the correlation of BIV and bovine leukemia virus infection, all sera were analysed for BLV antibodies and there was only a slight association between both infections. Overall, these results show that BIV infection is present in dairy cattle in Poland at a prevalence rate found in other European countries. 相似文献
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108.
不同硒水平对生长育肥猪血液生化指标的影响 总被引:5,自引:1,他引:4
试验研究了宁夏常用饲料中不同硒水平对生长育肥猪血液生化指标的影响。结果表明 :(1 )谷胱甘肽过氧化物酶 (GSH PX)活性随饲粮硒水平的增加 ,呈现下降 上升 下降的动态变化趋势。谷胱甘肽硫转移酶可反映缺硒的程度。 (2 )缺硒组仔猪血硒含量和全血中GSH PX均处于缺硒边缘状态 ,在临界值以下 ,不能满足仔猪的代谢需要。 (3)随饲粮硒水平的逐渐增加 ,猪瘟的抗体水平和淋巴细胞转化率明显升高 ,以饲粮中添加硒 0 45mg/kg时达到最高 ,仔猪发病率最低 相似文献
109.
本试验旨在研究饲粮添加低聚木糖水平对1~21日龄和22~42日龄爱拔益加(AA)肉仔鸡生长性能、血液生理和血浆生化指标、器官发育和组织病理学变化的影响,从而评价低聚木糖对肉仔鸡饲用的生物安全性。试验采用单因子完全随机设计。选用240只1日龄AA肉仔鸡,随机分为4个组(每个组6个重复,每个重复10只鸡,公、母各5只),分别饲喂低聚木糖添加量为0、160、800和1 600 mg/kg的试验饲粮。试验期为42 d。结果表明,饲粮添加1 600 mg/kg低聚木糖显著提高21日龄肉仔鸡血浆球蛋白浓度和42日龄肉仔鸡血浆葡萄糖浓度(P0.05),显著降低21日龄肉仔鸡血浆磷酸肌酸激酶和谷丙转氨酶活性以及42日龄肉仔鸡血浆甘油三酯浓度(P0.05);800 mg/kg添加组42日龄肉仔鸡肾脏相对重量显著高于对照组和1 600 mg/kg添加组(P0.05)。以上结果表明,肉仔鸡玉米-豆粕型饲粮中低聚木糖的最高添加限量定为160 mg/kg,具有10倍的安全系数,对肉仔鸡饲用是安全的。 相似文献