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41.
OBJECTIVE: To evaluate mRNA expression of several proinflammatory and anti-inflammatory cytokines and chemokines in equine unstimulated and interleukin-1beta (IL-1beta)-stimulated chondrocytes. STUDY DESIGN: In vitro experiment using equine chondrocyte cultures. SAMPLE POPULATION: Whole articular cartilage from metacarpophalangeal joints (n=5 horses; 10 fetlocks). METHODS: Chondrocyte monolayer cultures were established from digested adult equine articular cartilage and stimulated with 5 ng/mL of recombinant human IL-1beta. RNA was extracted from the cells 24 hours after stimulation. IL-1beta, IL-4, IL-6, IL-8, tumor necrosis factor-alpha (TNF-alpha), and ubiquitin (house keeping gene) mRNA expression were investigated by real-time RT-PCR. RESULTS: IL-1beta, IL-6, and IL-8 mRNA were expressed in unstimulated chondrocytes from macroscopically normal joints and were significantly up-regulated after stimulation (5/5 horses). IL-4 mRNA was not detected in any samples (0/5 horses). TNF-alpha mRNA, by comparison, was expressed in 2/5 unstimulated samples and in all stimulated samples but a considerable sample variation in response to IL-1beta stimulation was observed. CONCLUSIONS: Equine chondrocytes express mRNA for several proinflammatory cytokines and chemokines and IL-1beta modulates their expression. CLINICAL RELEVANCE: Chondrocytes express proinflammatory cytokines and chemokines capable of modulating a local inflammatory cascade in articular cartilage, which could potentially lead to focal degradation and osteoarthritis. 相似文献
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Florent Noulekoun Emiru Birhane Stella Chude Amanuel Zenebe 《Agroforestry Systems》2017,91(1):123-135
Concerns about sustainable management and conservation of multipurpose trees in their habitat have led to increased number of studies on the ecological characterization of their population. Such knowledge on Faidherbia albida, the most used tree in agroforestry parklands in Ethiopia, is limited. F. albida population was characterized in and compared between two agroforests having different conservation status in Northern Ethiopia. Population structural parameters along with environmental factors and human activities were assessed in 42 randomly installed plots using a transect method. Size class distribution was used to describe and analyze the species long-term population dynamics. Adult density was almost three times higher in Zongi agroforest (19.9 ± 2.9 trees ha?1) where the species has been conserved and managed for longer time compared to Abraha-atsbeha agroforest (7.9 ± 2.5 trees ha?1). The same trend was observed for tree morphological parameters which were significantly higher at Zongi than Abraha-atsbeha. However, size class distributions coefficient of skewness and the median diameter indicated a declining and vulnerable population at Zongi and an increasing population at Abraha-atsbeha. Species population characteristics were influenced by environmental factors such as altitude, stone cover, erosion severity, slope, and human-related disturbances including land use, fodder harvesting, distance away from the center of the village and proximity of household to the plots. The study confirms the impact of conservation, environmental factors and human disturbances on shaping F. albida population and recommends the consideration of the trade-offs between them to design effective conservation and management strategies to sustain F. albida agroforests. 相似文献
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Anne‐Sophie Walker Annie Micoud Florent Rémuson Jacques Grosman Michel Gredt Pierre Leroux 《Pest management science》2013,69(6):667-678
Resistance to fungicides is an evolutionary process resulting from the selection of advantageous genotypes in naturally diverse populations. Seven fungicide modes of action are authorised to control grey mould caused by Botrytis cinerea on grapevine in France, and five of them have encountered specific resistance, with variable frequencies in populations and possible consequences for field fungicide efficacy. Moreover, multidrug resistance is caused by fungicide efflux and allows a weak resistance towards six unrelated modes of action. Here, a review is given of the fungicide resistance status of B. cinerea in France, particularly in the vineyards of Champagne, which are the most affected. Recently developed resistance and recent findings concerning the associated resistance mechanisms are focused upon in particular. Finally, antiresistance strategies are presented, and examples of managed resistance are discussed in a more general manner with the aim of extending this knowledge to other crops and countries undergoing similar resistance problems. © 2013 Society of Chemical Industry 相似文献
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Relave F David F Leclère M Alexander K Bussières G Lavoie JP Marcoux M 《Veterinary surgery : VS》2008,37(3):232-240
Objective— To evaluate use of pre‐tied ligating loop to perform thoracoscopic, large lung biopsy in normal and heaves‐affected horses. Study Design— Prospective clinical study. Animals— Normal (n=5) and heaves‐affected (n=6) horses. Methods— Lung biopsies, 1 from each hemithorax, were collected thoracoscopically using a pre‐tied ligating loop. Horses were either normal (C) or heaves‐affected with the latter being in remission (Ha) for the initial biopsy and in exacerbation (Hs) for the 2nd biopsy. Clinical variables, PaO2, and PaCO2 were used to determine the effect of surgical biopsy. Postoperative pneumothorax was monitored by serial thoracic radiographic examinations. Results— Thoracoscopic lung biopsy (n=29, 22 procedures) was well tolerated by all horses. Complication rate was 31%, including 8 ligature slippage and 1 pulmonary hemorrhage. Intranasal oxygen was administered intraoperatively to 6 horses (2 C, 1 Ha, 3 Hs) with severe hypoxemia or labored breathing. There was a significant decrease in PaO2 during surgery in horses not supplemented with oxygen. Postoperative pneumothorax (21/22 procedures) detected radiographically resolved within 3 weeks. Conclusion— Thoracoscopic lung biopsy using pre‐tied ligating loops was minimally invasive, relatively inexpensive, and fairly efficient. Heaves‐affected horses tolerated the surgery well, even when in exacerbation; however, the technique was associated with non life‐threatening complications in 31% of the biopsies, most of which required correction with additional ligating loops or more sophisticated instrumentation. Clinical Relevance— Using laparoscopic pre‐tied ligating loop for thoracoscopically‐assisted lung biopsy can be considered in horses with normal and impaired lung function but alternative instrumentation and access to intranasal oxygen must be available to the surgeon in case of complications. 相似文献
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Context
Habitat loss and fragmentation may alter habitat occupancy patterns, for example through a reduction in regional abundance or in functional connectivity, which in turn may reduce the number of dispersers or their ability to prospect for territories. Yet, the relationship between landscape structure and habitat niche remains poorly known.Objectives
We hypothesized that changes in landscape structure associated with habitat loss and fragmentation will reduce the habitat niche breadth of forest birds, either through a reduction in density-dependent spillover from optimal habitat or by impeding the colonization of patches.Methods
We surveyed forest birds with point counts in eastern Ontario, Canada, and analyzed their response to loss and fragmentation of mature woodland. We selected 62 landscapes varying in both forest cover (15–45%) and its degree of fragmentation, and classified them into two categories (high versus low levels of loss and fragmentation). We determined the habitat niche breadth of 12 focal species as a function of 8 habitat structure variables for each landscape category.Results
Habitat niche breadth was narrower in landscapes with high versus low levels of loss and fragmentation of forest cover. The relative occupancy of marginal habitat appeared to drive this relationship. Species sensitivity to mature forest cover had no apparent influence on relative niche breadth.Conclusions
Regional abundance and, in turn, density-dependent spillover into suboptimal habitat appeared to be determinants of habitat niche breadth. For a given proportion of forest cover, fragmentation also appeared to alter habitat use, which could exacerbate its other negative effects unless functional connectivity is high enough to allow individuals to saturate optimal habitat.50.
The acid dissociation and ferric stability constants for complexation by the flavonoids 3-hydroxyflavone (flavonol), 5,7-dihydroxyflavone (chrysin), and 3',4'-dihydroxyflavone in 50:50 (v/v) ethanol/water are determined by pH potentiometric and spectrophotometric titrations and the linear least-squares curve-fitting program Hyperquad. Over the entire range of pH and reagent concentrations spanning the titration experiments, the stoichiometry for iron-flavonoid complex formation was 1:1 for all three flavonoids examined. The three flavonoids were chosen for their hydroxy substitution pattern, with each possessing one of the three most commonly suggested sites for metal binding by the flavonoids. On the basis of the calculated stability constants, the intraflavonoid-binding site competition is illustrated as a function of pH via speciation curves. The curves indicate that the binding site comprised of the 3',4'-hydroxy substitutions, the catecholic site, is most influential for ferric complexation at the physiological pH of 7.4. The possibility for antioxidant activity by flavonoid chelation of ferric iron in the presence of other competitive physiological complexing agents is demonstrated through additional speciation calculations. 相似文献