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11.
Weaned pigs were immunised with a live attenuated Salmonella choleraesuis vaccine. The protective immunity induced was compared with that of unvaccinated pigs by intranasal challenge with a field strain of S choleraesuis. Of 18 unvaccinated pigs, three died as a result of challenge from S choleraesuis and 10 of the survivors developed chronic lung lesions. None of the vaccinated pigs died as a result of challenge and two only showed macroscopic evidence of salmonellosis on autopsy three weeks after challenge. It was concluded that subcutaneous vaccination of pigs prevented death and clinical illness but did not prevent invasion of tissues following intranasal challenge with S choleraesuis.  相似文献   
12.
Elbow incongruity is a form of elbow dysplasia that causes osteoarthritis, pain, and lameness, and it is common in chondrodystrophic dog breeds. The objective of this retrospective secondary analysis study was to evaluate the intra‐ and interobserver repeatability of a novel radiographic incongruity grading system for assessing elbow incongruity in three chondrodystrophic dog breeds—the dachshund, Skye Terrier, and Glen of Imaal Terrier. We conducted an observer agreement study that included 220 mediolateral antebrachial radiographs from 110 dogs with the elbow in 90° flexion. The radiographs were independently assessed by three observers at three time points, using a four‐stepped grading scale. The proportion of agreement and Kappa coefficient were calculated. Both the intra‐ and interobserver proportions of agreement were substantial when three grades were required to be identical (.705‐.777 and .609, respectively), and almost perfect for two identical grades (.991‐1.000 and .991, respectively). Some differences in repeatability between breeds were noted; specifically, the intraobserver repeatability was higher in the dachshund, and the interobserver repeatability was lower in the Glen of Imaal Terrier. Our study showed that the radiographic imaging protocol and incongruity grading system have high repeatability when assessing elbow incongruity in chondrodystrophic dog breeds.  相似文献   
13.
Nuclear ribosomal DNA regions (i.e. large subunit, internal transcribed spacer, 5.8S and intergenic spacer) were sequenced using a direct‐polymerase chain reaction method from Armillaria ostoyae genets collected from the western USA. Many of the A. ostoyae genets contained heterogeneity among rDNA repeats, indicating intragenomic variation and likely intraspecific hybridization. Intragenomic variation was verified by visually editing base‐sequence offsets in regions with insertions/deletions, and using sequence‐specific internal primers to resequence heterogeneous regions. Phylogenetic analyses with Bayesian Inference methods were used to define groups within A. ostoyae. Analysis of A. ostoyae from outside the western USA indicated the presence of a Circumboreal group of A. ostoyae that also occurs in Utah; two other phylogeographic groups were associated with the Rocky Mountain and Pacific Northwest regions of the USA. Mixed sequence types, an indication of intraspecific hybrids, were common in some geographic regions. Hybridization events may have influenced species evolution, contributing to variation in pathogenicity and virulence. The occurrence of these groups and intraspecific hybrids also indicates that paleogeography and paleoclimate may have influenced the phylogeography of A. ostoyae. In addition, other Armillaria species were examined for evolutionary relationships with the groups of A. ostoyae. These findings will provide a basis for future research relating ecological function to genetic diversity within A. ostoyae.  相似文献   
14.
Dieback of young Quercus robur seedlings can limit natural regeneration in mixed-species forest stands in Poland. The aim of this study was to examine the role of fungi in the dieback of oak seedlings in central Europe. Fungi were isolated from the stems and roots of Q. robur, from both healthy seedlings and seedlings with symptoms, that were sampled from four stands in Poland. In total, 111 distinct taxa were identified. Ascomycota was dominant, representing 95.6% of the isolates. Among the taxa identified, Alternaria alternata, Colletotrichum fioriniae, Colletotrichum godetiae, Coniella quercicola, Diaporthe eres, Gnomoniopsis paraclavulata, Ilyonectria rufa, Mucor genevensis, Penicillium glandicola, Tubakia dryina, and Umbelopsis changbaiensis were most frequently isolated, and were consistently found in stems and roots of both healthy and diseased plants. The community compositions of fungi in healthy and diseased stems were similar, although Fusarium species, especially Fusarium sp. 1 (FTSC 5) and F. sporotrichioides, were found mainly in seedlings with symptoms. The pathogenicity of the most consistently isolated species from stems and roots of diseased seedlings was tested on Q. robur seedlings. F. sporotrichioides caused the largest lesions on inoculated seedlings. Six weeks after inoculation, D. eres, C. fioriniae, G. paraclavulata, T. dryina, and F. sporotrichioides killed 0%–18.8% of seedlings, while I. rufa and Ilyonectria pseudodestructans did not cause any lesions or other symptoms. This study is the first comprehensive report suggesting that massive fungal attack can lead to oak seedling dieback in mixed-species forest stands in central Europe.  相似文献   
15.
Induction of angiogenesis is a potential treatment for chronic ischemia. Low molecular weight fucoidan (LMWF), the sulfated polysaccharide from brown seaweeds, has been shown to promote revascularization in a rat limb ischemia, increasing angiogenesis in vivo. We investigated the potential role of two heparan sulfate (HS) metabolism enzymes, exostosin-2 (EXT2) and heparanase (HPSE), and of two HS-membrane proteoglycans, syndecan-1 and -4 (SDC-1 and SDC-4), in LMWF induced angiogenesis. Our results showed that LMWF increases human vascular endothelial cell (HUVEC) migration and angiogenesis in vitro. We report that the expression and activity of the HS-degrading HPSE was increased after LMWF treatment. The phenotypic tests of LMWF-treated and EXT2- or HPSE-siRNA-transfected cells indicated that EXT2 or HPSE expression significantly affect the proangiogenic potential of LMWF. In addition, LMWF increased SDC-1, but decreased SDC-4 expressions. The effect of LMWF depends on SDC-4 expression. Silencing EXT2 or HPSE leads to an increased expression of SDC-4, providing the evidence that EXT2 and HPSE regulate the SDC-4 expression. Altogether, these data indicate that EXT2, HPSE, and SDC-4 are involved in the proangiogenic effects of LMWF, suggesting that the HS metabolism changes linked to LMWF-induced angiogenesis offer the opportunity for new therapeutic strategies of ischemic diseases.  相似文献   
16.
Designing responsive buckled surfaces by halftone gel lithography   总被引:1,自引:0,他引:1  
Self-actuating materials capable of transforming between three-dimensional shapes have applications in areas as diverse as biomedicine, robotics, and tunable micro-optics. We introduce a method of photopatterning polymer films that yields temperature-responsive gel sheets that can transform between a flat state and a prescribed three-dimensional shape. Our approach is based on poly(N-isopropylacrylamide) copolymers containing pendent benzophenone units that allow cross-linking to be tuned by irradiation dose. We describe a simple method of halftone gel lithography using only two photomasks, wherein highly cross-linked dots embedded in a lightly cross-linked matrix provide access to nearly continuous, and fully two-dimensional, patterns of swelling. This method is used to fabricate surfaces with constant Gaussian curvature (spherical caps, saddles, and cones) or zero mean curvature (Enneper's surfaces), as well as more complex and nearly closed shapes.  相似文献   
17.
Background: In veterinary medicine, there is increasing interest in measuring C‐reactive protein (CRP) as a tool for diagnosis and monitoring of inflammatory diseases. Reported CRP concentrations for healthy dogs have ranged from 0 to 8.9 mg/L. Objectives: The aims of this study were to evaluate a canine‐specific point‐of‐care (POC) lateral flow immunoassay for qualitative CRP measurement in healthy and diseased dogs and to compare results with those obtained by a quantitative ELISA. Methods: Blood samples from 73 client‐owned dogs were available for testing: 16 healthy dogs and 57 dogs with a variety of infectious, inflammatory, or neoplastic diseases. CRP was measured in heparinized whole blood samples and serum with the TECOmedical Dog CRP‐visual POC test. A red line develops in the POC device if CRP is ≥5 mg/L, and results are scored as negative or positive. An ELISA validated previously for canine serum was used as the reference method. Results: For all dogs, serum CRP concentrations measured by the ELISA ranged from 0.1 to ≥350 mg/L (median=38 mg/L). Percentages of the CRP POC test results that agreed with the ELISA results were 98.6% for whole blood and 97.3% for serum samples. For serum samples, sensitivity of the POC test was 96.4% and specificity was 81.3%. For whole blood, sensitivity was 94.7% and specificity was 93.8%. Conclusions: The POC test had very good agreement with the ELISA test and had high sensitivity and specificity; therefore, it can be used as a qualitative test to screen for increases in CRP concentrations.  相似文献   
18.
Subsurface-banding manure and winter cover cropping are farming techniques designed to reduce N loss. Little is known, however, about the effects of these management tools on denitrifying microbial communities and the greenhouse gases they produce. Abundances of bacterial (16S), fungal (ITS), and denitrification genes (nirK, nirS, nosZ-I, and nosZ-II) were measured in soil samples collected from a field experiment testing the combination of cereal rye and hairy vetch cover cropping with either surface-broadcasted or subsurface-banded poultry litter. The spatial distribution of genes was mapped to identify potential denitrifier hotspots. Spatial distribution maps showed increased 16S rRNA genes around the manure band, but no denitrifier hotspots. Soil depth and nitrate concentration were the strongest drivers of gene abundance, but bacterial gene abundance also differed by gene, soil characteristics, and management methods. Gene copy number of nirK was higher under cereal rye than hairy vetch and positively associated with soil moisture, while nirS gene copies did not differ between cover crop species. The nirS gene copies increased when manure was surface broadcasted compared to subsurface banded and was positively associated with pH. Soil moisture and pH were positively correlated to nosZ-II but not to nosZ-I gene copy numbers. We observed stronger correlations between nosZ-I and nirS, and nosZ-II and nirK gene copies compared to the reverse pairings. Agricultural management practices differentially affect spatial distributions of genes coding for denitrification enzymes, leading to changes in the composition of the denitrifying community.  相似文献   
19.
ObjectiveTo compare the dose, cardiopulmonary effects and quality of anaesthetic induction in dogs using propofol (10 mg mL–1) and diluted propofol (5 mg mL–1).Study designRandomized, blinded, clinical study.AnimalsA total of 28 client-owned dogs (12 males/16 females).MethodsFollowing intramuscular acepromazine (0.02 mg kg–1) and methadone (0.2 mg kg–1), propofol (UP, 10 mg mL–1) or diluted propofol (DP, 5 mg mL–1) was administered intravenously (0.2 mL kg–1 minute–1) by an anaesthetist unaware of the allocated group to achieve tracheal intubation. Sedation, intubation and induction quality were scored from 0 to 3. Pre- and post-induction pulse rate (PR), respiratory rate (fR) and systolic (SAP), mean (MAP) and diastolic (DAP) arterial blood pressure were compared. Time to first breath and induction dose were recorded. Data were analysed for normality and Mann–Whitney U or Student t tests were performed where appropriate. Significance was set at p < 0.05. Data are presented as mean ± standard deviation or median (range).ResultsThe propofol dose administered to achieve induction was lower in the DP group (2.62 ± 0.48 mg kg–1) than in the UP group (3.48 ± 1.17 mg kg–1) (p = 0.021). No difference was observed in pre- and post-induction PR, SAP, MAP, DAP and fR between groups. The differences between post-induction and pre-induction values of these variables were also similar between groups. Time to first breath did not differ between groups. Sedation scores were similar between groups. Quality of tracheal intubation was marginally better with UP 0 (0–1) than with DP 1 (0–2) (p = 0.036), but overall quality of induction was similar between groups [UP 0 (0–1) and DP 0 (0–1), p = 0.549].Conclusion and clinical relevanceDiluting propofol reduced the dose to induce anaesthesia without significantly altering the cardiopulmonary variables.  相似文献   
20.
For northern Europe’s climate, models predict an increase in periods of drought and waterlogging. Knowledge of variation between genotypes of Betula pendula (birch) and Populus tremula (aspen) to drought and excess soil moisture are unavailable but relevant for future development of forest ecosystems. We studied variation between genotypes to soil moisture in birch and aspen with plant material representing naturally regenerated populations and showed differences in acclimation to soil moisture conditions. Genotypes showing most growth and biomass accumulation across treatments maintained most leaf area, high gas exchange and water-use efficiency and grew most root mass but had the lowest root length per unit root dry mass compared to other genotypes. This indicates that these genotypes are more efficient in harvesting water from the soil under adverse conditions. We also showed that birch and aspen employ different strategies to cope with soil moisture conditions, with aspen investing more in perennial parts, while birch efficiently maintains foliar processes. When the expression of some known drought responsive genes was measured, only ACC oxidase was induced by the drought treatment at the beginning of the experiment, while surprisingly LEA5, RD22 and ADH1 did not respond to drought, but were up-regulated in prolonged wet conditions indicating oxidative stress and hypoxia and that these genes are responding to multiple stress factors. We conclude that in plants micro-propagated from naturally regenerated birch and aspen populations, there is variation between genotypes in acclimation efficiency to soil moisture conditions.  相似文献   
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