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31.
The fungal pathogen Monilinia fructicola causes blossom blight and fruit brown rot of stone fruits in California. In this study, spore densities in the air were monitored in six orchard/year combinations with Burkard spore traps. A real-time PCR assay was developed to efficiently quantify the dynamics of spore density in these orchards during the growing season. Different patterns of dynamics of spore density were observed in these orchards. A linear relationship between numbers of spores counted with a compound microscope and those determined with the real-time PCR assay was obtained, using the same samples of spore traps. Spore density in five of six orchard/year combinations ranged from 0.0 to 0.05 spores l−1, except for that in orchard 4, which showed much higher values of spore density in the air, as well as higher values and wider range of incidences of blossom infection and fruit rot than those in the other orchards. The results demonstrated a potential method to quantitatively determine spore inoculum potential in orchards by using a real-time PCR assay.  相似文献   
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A high molecular-mass proteolytic enzyme of Actinobacillus pleuropneumoniae serotype 1, was purified from culture supernatants (CSN) by using DEAE-cellulose and sepharose-4B-gelatin chromatography. In 10% SDS-polyacrylamide gels copolymerized with porcine gelatin, the protease showed a single band of activity of > 200 kDa. However, minor molecular-mass proteolytic bands were observed when the protease was electrophoresed in the presence of either 5% beta-mercaptoethanol, 50 mM dithiothreitol, or 0.25 M urea. Furthermore, when the > 200-kDa purified protein was passed through a sucrose gradient, several bands with proteolytic activity were found: 62, 90, 190, and 540 kDa. The proteolytic activity was increased in the presence of calcium or zinc and was not affected after being heated at 90 degrees C for 5 min. Proteolytic activities were also observed in CSN from all A. pleuropneumoniae serotypes and biotypes. The purified protease hydrolyzed porcine IgA and IgG in vitro. In addition, by immunoblot the protease was recognized by serum of naturally infected pigs with serotypes 1 and 5, and by serum of pigs experimentally infected with serotypes 1, 2, 8, or 9. Serum of a pig vaccinated with CSN of a serotype 3 strain also recognized the protease, but not sera of pigs vaccinated with a bacterin (serotype 1). Proteins from CSN of all the serotypes, which were precipitated with 70% (NH4)2SO4, were recognized by a polyclonal antibody raised against the purified protease. Taken together these results indicate that an antigenic protease is produced in vivo by all the serotypes of A. pleuropneumoniae. The results indicate that proteases could have a role in the disease and in the immune response of pigs infected with A. pleuropneumoniae.  相似文献   
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生物网络是系统生物学研究的重要内容。本文介绍了多种常用复杂生物网络可视化系统,针对Cytoscape系统在可视化的建模过程以及在建模过程中使用到的布局算法进行对比研究,并利用Cytoscape系统中丰富的插件对复杂网络数据进行分析,包括对数据进行网络分析和更改、使用BINGO插件进行基因注释、使用AGILENT LITERATURE SEARCH(ALS)插件搜索基因相互作用文献等。  相似文献   
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AIM:To elucidate the molecular mechanisms of lipoic acid (LA) on redox regulation and digestive function in intestine of C57BL/6 mice fed high fat diet (HFD).METHODS:C57BL/6 mice were randomly assigned to one of three groups (n=8).The control group consumed an ordinary diet.The other two experimental groups were fed with a high fat diet, high fat plus 0.1% LA.After 6 weeks, the activities of digestive enzymes were examined.In order to evaluate the antioxidant status of the mice, superoxide dismutase (SOD), malondialdehyde (MDA), total antioxidant capacity (TAC) and reactive oxygen species (ROS) in intestinal homogenate were measured.To investigate the molecular mechanisms underlying the effects of LA, the gene expression profiles in intestine were examined using the GeneChip microarray system.RESULTS:A depressed antioxidant defense system, accompanied by digestive and absorptive function impairment, was observed in HFD-fed mice.These changes were partially restored in the LA-treated group.DNA microarray analysis of intestine showed that LA ingestion up-regulated the expression of genes related to free-radical scavenger enzymes, digestive enzymes and transporters.CONCLUSION:Treatment with LA improves redox homeostasis and the function of intestine in mice fed HFD.The mechanism may involve preventing oxidative stress by scavenging ROS directly and increasing those of free-radical scavenger enzymes gene expression indirectly.  相似文献   
35.
Long-term oral treatment with cimetidine is recommended to reduce vomiting in dogs with chronic gastritis. Despite this, few studies have specifically examined the plasma disposition and pharmacokinetics of cimetidine in dogs, particularly following repeated oral administration. The pharmacokinetics of cimetidine following oral administration as tablets was investigated in healthy dogs. Cimetidine was absorbed rapidly post-treatment ( t max = 0.5 h). A mean absolute bioavailability of 75% was calculated following a single oral administration of 5 mg cimetidine/kg body weight. After intravenous administration, a plasma half-life of 1.6 h was calculated. Repeated oral administration at the recommended dose rate and regime (5 mg/kg body weight three times daily) for 30 consecutive days did not lead to any accumulation of cimetidine in plasma. Food intake concomitant with oral administration of cimetidine delayed ( t max = 2.25 h) and decreased the rate and extent of absorption ( AUC ) by about 40%. Cimetidine was well absorbed in fasted dogs. Administration of food decreased the bioavailability of cimetidine by 40%. Cimetidine does not accumulate over time in plasma when administered long term to dogs.  相似文献   
36.
AIM: To explore the mutual effect of co-culture of wild-type astrocytes (ASC) and motor neurons VSC4.1 (VSC) on the respective ability to produce reactive oxygen species (ROS). METHODS: The inhibition rates of cell growth in ASC and VSC in co-culture or independent culture was detected after exposed to excitatory stimulus by MTT method. Real-time observation of ROS production by ASC and VSC labeled with Hoechst 33342 was detected by confocal microscopy under the conditions of co-culture or independent culture. RESULTS: Higher concentration of glutamate induced a higher inhibition rate in mixed cell growth than that in ASC alone, while lower concentration of glutamate induced a higher inhibition rate in mixed cell growth than that in VSC only. Real-time observation by confocal microscopy showed that ROS production by VSC under the condition of co-culture, which showed a notable increase at 15 min, was significant less than that in independent culture, which peaked at 5 min and was gradually decreased. ROS production by ASC in co-culture began to increase significantly at 10 min. CONCLUSION: Compared to independent culture, ASC reduces the resting ROS production by co-cultured with VSC, while ASC prolongs the duration of ROS production by VSC after exposed to excitatory stimulus.  相似文献   
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Only a few of the registered insecticides against Cydia pomonella L. are still effective in areas where insecticide resistance has emerged in this pest. Resistance mechanisms are multiple, and their lone or cumulative effects in a single population are not completely understood. A detailed estimation of resistance spectrum is still required to define the suitable insecticides to use against a given population. The efficacy of ten insecticides was therefore investigated together with the resistance mechanisms expressed in four laboratory strains and 47 field populations of C. pomonella from five countries. Bioassays were performed using topical applications of diagnostic concentrations on diapausing larvae, and resistance mechanisms were analysed on adults emerging from control insects. All populations exhibited a reduced susceptibility to at least one insecticide when compared with the susceptible laboratory strain. Cross-resistances were observed between azinphos-methyl or phosalone and more recent compounds such as spinosad and thiacloprid. Resistances to azinphos-methyl, diflubenzuron, spinosad, tebufenozide and thiacloprid were significantly correlated with mixed-function oxidase activity, while increased glutathione-S-transferase and reduced non-specific esterase activities were correlated with resistance to azinphos-methyl and emamectin, respectively. Conversely, resistances to azinphos-methyl, tebufenozide and thiacloprid were negatively correlated with increased esterase activity. None of the observed mechanisms explained the loss of susceptibility of populations to chlorpyrifos-ethyl, and no significant correlation was detected between resistance to deltamethrin and the presence of the kdr mutation. The suitability of such non-target instars to monitor insecticide resistance in field populations is discussed.  相似文献   
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