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411.
Stefania Bena Sarah E Headland Simon McArthur Vincenzo Brancaleone Mauro Perretti 《EMBO reports》2013,14(11):999-1007
Neutrophil activation and adhesion must be tightly controlled to prevent complications associated with excessive inflammatory responses. The role of the anti‐inflammatory peptide chemerin15 (C15) and the receptor ChemR23 in neutrophil physiology is unknown. Here, we report that ChemR23 is expressed in neutrophil granules and rapidly upregulated upon neutrophil activation. C15 inhibits integrin activation and clustering, reducing neutrophil adhesion and chemotaxis in vitro. In the inflamed microvasculature, C15 rapidly modulates neutrophil physiology inducing adherent cell detachment from the inflamed endothelium, while reducing neutrophil recruitment and heart damage in a murine myocardial infarction model. These effects are mediated through ChemR23. We identify the C15/ChemR23 pathway as a new regulator and thus therapeutic target in neutrophil‐driven pathologies. 相似文献
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Female Eider ducks, living under natural conditions, do not drink salt water during the 26 days for which they incubate their eggs. In the course of incubation the nasal salt glands decrease in size, show a marked reduction in Na+ /K+ -ATPase activity and in the rate at which they clear a salt load. The time course of these events is similar to that seen in laboratory studies on other species where salt intake is manipulated. 相似文献
414.
Parallel increases in the ornithine carbamyl transferase and glutamate dehydrogenase activities were observed in the serum of 22 Reye's syndrome patients. The increase in the activity of glutamate dehydrogenase was masked by a dialyzable inhibitor. It is proposed that the measurement of serum ornithine carbamyl transferase and glutamate dehydrogenase activities may be useful as an indicator of liver mitochondrial damage in Reye's syndrome. 相似文献
415.
Protoplast membranes and the particulate D,D-carboxypeptidase of Bacillus coagulans NCIB 9365 were extremely resistant to disruption by either detergents or urea. A combination of urea and the non-ionic detergent Genapol X-100 was required to achieve a significant solubilisation of membrane protein and D,D-carboxypeptidase in an active form; the pH optimum for this treatment was pH 7.5. Solubilisation of the enzyme was accompanied by a two-fold enhancement of activity. Kinetic results indicated that the enhancement may be due to an alteration in the conformation of the enzyme following disruption of membrane structure. 相似文献
416.
Effects of within-patch characteristics on the vulnerability of a plant to herbivory 总被引:2,自引:1,他引:1
Consumption of a focal plant by herbivores depends, not only on the physical and chemical characteristics of that plant, but also on the characteristics of the neighbouring vegetation. Consumption of focal plants has been related to their own characteristics and to the quality of the neighbouring vegetation, but the two have not been combined to examine the relative importance of focal plant and neighbouring vegetation characteristics.
We conducted a series of feeding trials to examine the relative importance of focal plant and various characteristics of neighbouring vegetation to browsing of a focal plant within vegetation patches. We planted Eucalyptus nitens seedlings of high and low nutrient status amongst vegetation patches differing in palatability, abundance and height. Generalist mammalian herbivores, red-bellied pademelons ( Thylogale billardierii ), were allowed to feed in each of these patches one at a time, and seedling consumption was recorded. Results were considered in light of the attractant-decoy and apparency hypotheses, which focus on the outcome to plants, and in terms of foraging theory, which is process-focussed.
Seedling and vegetation characteristics were both important. Seedlings of high nutrient status were preferred over those of low nutrient status. The relative quality, abundance and height of neighbouring vegetation all influenced browsing of a focal plant. Seedlings were more vulnerable amongst vegetation that was of low palatability, of low abundance, or was short. Seedling and vegetation effects were additive in two of three trials.
Results were consistent with both the attractant-decoy and apparency hypotheses, and could be explained in terms of maximising foraging efficiency. They demonstrate the need to consider characteristics of both the focal plant and its neighbouring vegetation when predicting the vulnerability of the former to browsing by generalist herbivores. 相似文献
We conducted a series of feeding trials to examine the relative importance of focal plant and various characteristics of neighbouring vegetation to browsing of a focal plant within vegetation patches. We planted Eucalyptus nitens seedlings of high and low nutrient status amongst vegetation patches differing in palatability, abundance and height. Generalist mammalian herbivores, red-bellied pademelons ( Thylogale billardierii ), were allowed to feed in each of these patches one at a time, and seedling consumption was recorded. Results were considered in light of the attractant-decoy and apparency hypotheses, which focus on the outcome to plants, and in terms of foraging theory, which is process-focussed.
Seedling and vegetation characteristics were both important. Seedlings of high nutrient status were preferred over those of low nutrient status. The relative quality, abundance and height of neighbouring vegetation all influenced browsing of a focal plant. Seedlings were more vulnerable amongst vegetation that was of low palatability, of low abundance, or was short. Seedling and vegetation effects were additive in two of three trials.
Results were consistent with both the attractant-decoy and apparency hypotheses, and could be explained in terms of maximising foraging efficiency. They demonstrate the need to consider characteristics of both the focal plant and its neighbouring vegetation when predicting the vulnerability of the former to browsing by generalist herbivores. 相似文献
417.
Membranes from Micrococcus varians catalyse the de novo synthesis of poly(N-acetylglucosamine 1-phosphate) attached to noncrosslinked peptidoglycan through a linkage unit of N-acetylglucosamine phosphate-tri(glycerol phosphate). The absence of CDP-glycerol, one of the precursors of linkage unit, precludes the attachment of the sugar 1-phosphate polymer. This report is the first of such polymer attachment performed by membranes which are completely free of cell walls. 相似文献
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