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81.
Abstract. A novel disease affecting the brown-spotted grouper, Epinephelus tauvina Forskal, described here as Sleepy Grouper Disease1 (SGD), resulted in significant economic losses in some Singaporean marine net-cage farms from April to August 1992. Investigations suggested that the aetiological agent was a virus, probably introduced with imported groupers. The virus was provisionally identified as an iridovirus on morphological evidence. The disease caused extreme lethargy in affected fish with few visible external signs. Mortalities either occurred gradually over the week from onset of clinical signs, or over a shorter period and in large numbers if fish were stressed. Consistent tissue changes were seen by light microscopy in the spleen, heart and kidney of affected fish. Electron microscopy showed viral particles associated with damage to cell organelles. In an experimental infection, apparently healthy fish cohabiting with an infected fish developed similar lesions and died. The significance of SGD in grouper culture is discussed.  相似文献   
82.
The effect of inflammation on the disposition of phenylbutazone (PBZ) was investigated in Thoroughbred horses. An initial study ( n = 5) in which PBZ (8.8 mg/kg) was injected intravenously twice, 5 weeks apart, suggested that the administration of PBZ would not affect the plasma kinetics of a subsequent dose. Two other groups of horses were given PBZ at either 8.8 mg/kg ( n = 5) or 4.4 mg/kg ( n = 4). Soft tissue inflammation was then induced by the injection of Freud's adjuvant and the administration of PBZ was repeated at a dose level equivalent to, but five weeks later than, the initial dose. Inflammation did not appear to affect the plasma kinetics or the urinary excretion of PBZ and its metabolites, oxyphenbutazone (OPBZ) or hydroxyphenylbutazone (OHPBZ) when PBZ was administered at 8.8 mg/kg. However, small but significant increases ( P <0.05) in total body clearance ( CL B; 29.2 ± 3.9 vs. 43.8 ± 8.1 mL/ h-kg) and the volume of distribution, calculated by area ( V d(area); 0.18 ± 0.05 vs. 0.25 ± 0.03 L/kg) or at steady-state ( V d(SS); 0.17±0.04 vs. 0.25 ± 0.03 L/ kg), were obtained in horses after adjuvant injection, compared to controls, when PBZ was administered at 4.4 mg/kg which corresponded to relatively higher tissues concentrations and lower plasma concentrations (calculated) at the time of maximum peripheral PBZ concentration. Soft tissue inflammation also induced a significantly ( P <0.05) higher amount of OPBZ in the urine 18 h after PBZ administration but the total urinary excretion of analytes over 48 h was unchanged. These results have possible implications regarding the administration of PBZ to the horse close to race-day.  相似文献   
83.
The vascular leakage induced by histamine, bradykinin, serotonin and prostaglandin E1 and E2 was assessed. The test agents were injected intradermally into the shaved thoracic skin of horses and the vascular leakage estimated either semi-quantitatively by recording the diameter of the lesions or by measuring the actual volume of extravasated plasma in microliters using iodine-125-labelled human serum albumin (125I-HSA) as a marker in the blood plasma. Using the latter method, the vascular leakage induced by carrageenin and the effect of coadministered prostaglandins E1 and E2 upon the vascular leakage of both histamine and bradykinin were also investigated. No obvious lesions resulted when serotonin (10(-2) mol/l) was injected but histamine and bradykinin produced circular lesions which increased in diameter for approximately 30 min. The size of the lesions and volume of extravasated plasma was dose dependent. On a molar basis, bradykinin (10(-6) mol/l, 10(-5) mol/l) was more potent than histamine but they were equipotent at 10(-4) mol/l. The size of the lesions induced by carrageenin were independent of their anatomical location on the thorax. Except for the second hour, the hourly volume of vascular leakage increased until the fifth hour when the experiment was concluded. The maximum vascular leakage resulting from the injection of prostaglandin E1 or E2 (1, 10, 100 or 1000 ng) was 7 microliters but when co-administered with bradykinin (10(-6) mol/l), the volume of leaked plasma increased from 29 to 78 microliters. No synergy was observed when either prostaglandin was co-administered with histamine (10(-5) mol/l).  相似文献   
84.
麦田天敌监测资料统计标准的研究   总被引:1,自引:0,他引:1  
通过对麦田天敌消长规律的调查分析,从害虫防治和天敌利用的角度出发,提出天敌的最低利用指标,并作为划分天敌发生盛期的依据。同时提出用天敌高峰日发生量和发生盛期天数、后期网捕天敌量作为划分天敌发生程度的指标,并在麦田天敌监测资料统计中进行了具体应用。  相似文献   
85.
Different alleles of the human and ovine prion protein gene correlate with a varying susceptibility to transmissible spongiform encephalopathies. However, the pathogenic implications of specific polymorphisms in the bovine prion protein gene (PRNP) are only poorly understood. Previous studies on the bovine PRNP gene investigated common European and North American cattle breeds. As a consequence of decades of intensive breeding for specific traits, these modern breeds represent only a small fraction of the bovine gene pool. In this study, we analysed PRNP polymorphisms in the native Brazilian Caracu breed, which developed in geographical isolation since the 16th century. A total of 10 single nucleotide polymorphisms (SNPs) were discovered in the coding region of the Caracu PRNP gene. Eight of the SNPs occurred at high frequencies in Caracu cattle (variant allele frequencies = 0.10–0.76), but were absent or only rarely observed in European and North American breeds. One of the Caracu SNPs was associated with an amino acid exchange from serine to asparagine (f = 0.17). This SNP was not detected in Holstein–Friesian, Simmental and German Gelbvieh and was only rarely detected in beef cattle (f = 0.01). We found 17 haplotypes for PRNP in the Caracu breed.  相似文献   
86.
AIM:To evaluate whether tolerogenic dendri tic cells (DC) loaded with heat shock protein 60 (HSP60) inhibit the progression of aortic atherosclerotic plaque in hypercholesterolemic apolipoprotein E (Apo- E) -null mice.METHODS:Bone marrow derived DC of the mice were loaded with HSP 60 and co-cultured with rapamycin to generate tolerogenic DC.The tolerogenic DC ,DC loaded only HSP60 and PBS were injected into the ApoE-null mice at 8 weeks of age for three times at a one-week interval.8 weeks after the last injection,aorta were harvested for HE staining and anti-CD4+T cell immunostaining.Resp onses of pleenic cells to HSP60 were also evaluated.RESULTS:Compared with DC,DCHSP60 expressed higher levels of CD86,and stimulated T lymphocytes to proliferation significantly,while the tolerogenic DC expressed lower levels of CD86,and inhibited T lymphocytes to p roliferation.After immunization with different injection,the numbers of CD4+ T cells in plaque were increased significantly in DCHSP60 group vs in PBS g roup (P<0.01).On the other hand,they were reduced significantly in rap-DC HSP60 group vs in PBS group (P<0.01).Plaque areas in the tolerog enic DC group were smaller than that in the PBS group (P<0.01).Stimulated by HSP60,pleenic cells in tolerogenic DC group secreted more IL-10,while in DC HSP60 group more IFN-γ secretion was observed.CONCLUSION:HSP60 specific tolerogenic DC immunization attenuate d the progression of plaque,indicating a new immune therapy for atherosclerosis.  相似文献   
87.
Pour tester la résistance aux dicarboximides (imides cycliques) des souches prélevées en plein champ, les spores sont appliquees sur des disques d'agar placés à l'envers sur des milieux nutritifs contenant les différentes concentrations du fongicide. L'évaluation est faite 4 à 5 jours après le début de l'essai afin d'exclure les souches susceptibles de s'adapter après quelques jours de contact à la matiere active en laboratoire. En 1979, on a isolé pour la première fois, à partir de prélèvements de plein champ, des souches tolérantes à l ou 3 ppm de matière active. Une augmentation du nombre de souches résistantes a été constatèe en 1980. La croissance du mycélium et la germination des spores sont inhibées à peu prés de la meme manière. Les souches résistantes ne montrent pas de diminution de vigueur de Finfection sur pommes. L'efficacité de la lutte anti-botrytis n'est pas encore diminuee dans les parcelles qui ont un grand pourcentage de souches résistantes.  相似文献   
88.
The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.  相似文献   
89.
The aim of this study was to assess the effect of different slash management practices on understory biodiversity and biomass in Eucalyptus globulus coppices in Central Portugal. The experiment consisted of four treatments: (a) removal of slash (R), (b) broadcast over the soil (S), (c) as in S but concentrating woody residues between tree rows (W) and (d) incorporation of slash into soil by harrowing (I). Understory vegetation was surveyed during 1–6, 9, and 10 years, the proportion of soil cover by plant species estimated, and diversity and equitability indexes determined. Above ground understory biomass was sampled in years 2–6, 9, and 10. The highest number of species in most years occurred in plots where slash was removed. Differences between treatments in the proportion of plant soil cover were never significant, whereas differences in diversity index were only occasionally significant and apparently related to the number of species. Thus, differences in the equitability index were not significant. Understory biomass did not decrease during the rotation period, and was usually highest in R and I, and lowest in S, but not significantly different. At the end of the rotation period, understory biodiversity indices and biomass were apparently independent of slash treatment.  相似文献   
90.
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