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991.
Adipose tissue-derived mesenchymal stromal cells (ASCs) hold the promise of achieving successful immunotherapeutic results due to their ability to regulate different T-cell fate. ASCs also show significant adaptability to environmental stresses by modulating their immunologic profile. Cell-based therapy for inflammatory diseases requires a detailed understanding of the molecular relation between ASCs and Th17 lymphocytes taking into account the influence of inflammation and cell ratio on such interaction. Accordingly, a dose-dependent increase in Th17 generation was only observed in high MSC:T-cell ratio with no significant impact of inflammatory priming. IL-23 receptor (IL-23R) expression by T cells was not modulated by ASCs when compared to levels in activated T cells, while ROR-γt expression was significantly increased reaching a maximum in high (1:5) unprimed ASC:T-cell ratio. Finally, multiplex immunoassay showed substantial changes in the secretory profile of 15 cytokines involved in the Th17 immune response (IL-1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-22, IL-21, IL-23, IL-25, IL-31, IL-33, IFN-γ, sCD40, and TNF-α), which was modulated by both cell ratio and inflammatory priming. These findings suggest that Th17 lymphocyte pathway is significantly modulated by ASCs that may lead to immunological changes. Therefore, future ASC-based immunotherapy should take into account the complex and detailed molecular interactions that depend on several factors including inflammatory priming and cell ratio.  相似文献   
992.
Multiple adaptations were necessary when plants conquered the land. Among them were soluble phenylpropanoids related to plant protection and lignin necessary for upright growth and long‐distance water transport. Cytochrome P450 monooxygenase 98 (CYP98) catalyzes a rate‐limiting step in phenylpropanoid biosynthesis. Phylogenetic reconstructions suggest that a single copy of CYP98 founded each major land plant lineage (bryophytes, lycophytes, monilophytes, gymnosperms and angiosperms), and was maintained as a single copy in all lineages but the angiosperms. In angiosperms, a series of independent gene duplications and losses occurred. Biochemical assays in four angiosperm species tested showed that 4‐coumaroyl‐shikimate, a known intermediate in lignin biosynthesis, was the preferred substrate of one member in each species, while independent duplicates in Populus trichocarpa and Amborella trichopoda each showed broad substrate ranges, accepting numerous 4‐coumaroyl‐esters and ‐amines, and were thus capable of producing a wide range of hydroxycinnamoyl conjugates. The gymnosperm CYP98 from Pinus taeda showed a broad substrate range, but preferred 4‐coumaroyl‐shikimate as its best substrate. In contrast, CYP98s from the lycophyte Selaginella moellendorffii and the fern Pteris vittata converted 4‐coumaroyl‐shikimate poorly in vitro, but were able to use alternative substrates, in particular 4‐coumaroyl‐anthranilate. Thus, caffeoyl‐shikimate appears unlikely to be an intermediate in monolignol biosynthesis in non‐seed vascular plants, including ferns. The best substrate for CYP98A34 from the moss Physcomitrella patens was also 4‐coumaroyl‐anthranilate, while 4‐coumaroyl‐shikimate was converted to lower extents. Despite having in vitro activity with 4‐coumaroyl‐shikimate, CYP98A34 was unable to complement the Arabidopsis thaliana cyp98a3 loss‐of‐function phenotype, suggesting distinct properties also in vivo.  相似文献   
993.
994.
We evaluated a ready-to-use real-time quantitative Legionella pneumophila PCR assay system by testing 136 hot-water-system samples collected from 55 sites as well as 49 cooling tower samples collected from 20 different sites, in parallel with the standard culture method. The PCR assay was reproducible and suitable for routine quantification of L. pneumophila. An acceptable correlation between PCR and culture results was obtained for sanitary hot-water samples but not for cooling tower samples. We also monitored the same L. pneumophila-contaminated cooling tower for 13 months by analyzing 104 serial samples. The culture and PCR results were extremely variable over time, but the curves were similar. The differences between the PCR and culture results did not change over time and were not affected by regular biocide treatment. This ready-to-use PCR assay for L. pneumophila quantification could permit more timely disinfection of cooling towers.  相似文献   
995.
PolyP (inorganic polyphosphate) is a linear polymer of many tens or hundreds of orthophosphate residues found in a wide range of organisms, including bacteria, fungi, insects, plants and vertebrates. Despite its wide distribution in mammalian tissues and plasma, the biological functions of polyP on tumour metastasis and angiogenesis have not been previously examined. In the present study, we have shown that polyP effectively blocked in vivo pulmonary metastasis of B16BL6 cells by suppression of neovascularization, whereas it did not affect proliferation or adhesion to extracellular matrix proteins. PolyP not only inhibited bFGF (basic fibroblast growth factor)-induced proliferation and ERK (extracellular-signal-regulated kinase)/p38 MAPK (mitogen-activated protein kinase) activation of human endothelial cells, but also blocked the binding of bFGF to its cognate cell-surface receptor. Furthermore, polyP inhibited bFGF-induced in vitro and in vivo angiogenesis, suggesting that polyP possesses an anti-angiogenic activity. Since neovascularization is essential for tumour metastasis, our present findings clearly indicate that polyP has an in vivo anti-metastatic activity via its anti-angiogenic activity. Taken together with the fact that angiogenesis occurs under various normal and pathological conditions, our observations suggest that endogenous polyP may play a critical role during embryonic development, wound healing and inflammation, as well as in the progress of pathological diseases such as rheumatoid arthritis and cancer.  相似文献   
996.
BACKGROUND: 22q11 deletion syndrome (22q11DS) is characterized by conotruncal cardiac defects and hypoplasia of parathyroid glands and thymus, which result in variable hypoparathyroidism (HPT) and immune deficiency. METHODS: To study the course of HPT and the spectrum of other associated manifestations we evaluated all patients with 22q11DS, confirmed by fluorescence in situ hybridization, and HPT who were under follow-up at the Calcium-bone clinic, The Hospital for Sick Children, Toronto. Patients were clinically assessed and their hospital records were reviewed. RESULTS: Eighteen patients were included. At follow-up assessment at median age of 7.3 years HPT was judged complete in 11 (61%) and partial in 7 patients (39%). Patients with complete HPT presented with hypocalcemia later (median age at diagnosis 2.4 vs. 0.0 years) and more often with a hypocalcemic seizure than patients with partial HPT (73 vs. 29%). The spectrum of other associated manifestations did not differ between the groups. CONCLUSIONS: HPT in patients with 22q11DS is often partial. Many of the patients present with a hypocalcemic seizure which is predictive of complete HPT. Patients with complete and partial HPT do not differ in respect to their other associated features. Patients with features of 22q11DS should be actively screened for hypocalcemia to prevent development of symptomatic hypocalcemia.  相似文献   
997.
Nitrogen fertilization is a key factor for coffee production but creates a risk of water contamination through nitrate (NO3) leaching in heavily fertilized plantations under high rainfall. The inclusion of fast growing timber trees in these coffee plantations may increase total biomass and reduce nutrient leaching. Potential controls of N loss were measured in an unshaded coffee (Coffea arabica L.) plot and in an adjacent coffee plot shaded with the timber species Eucalyptus deglupta Blume (110 trees ha−1), established on an Acrisol that received 180 kg N ha−1 as ammonium-nitrate and 2,700 mm yr−1 rainfall. Results of the one year study showed that these trees had little effect on the N budget although some N fluxes were modified. Soil N mineralization and nitrification rates in the 0–20 cm soil layer were similar in both systems (≈280 kg N ha−1 yr−1). N export in coffee harvest (2002) was 34 and 25 kg N ha−1 yr−1 in unshaded and shaded coffee, and N accumulation in permanent biomass and litter was 25 and 45 kg N ha−1 yr−1, respectively. The losses in surface runoff (≈0.8 kg mineral N ha−1 yr−1) and N2O emissions (1.9 kg N ha−1 yr−1) were low in both cases. Lysimeters located at 60, 120, and 200 cm depths in shaded coffee, detected average concentrations of 12.9, 6.1 and 1.2 mg NO3-N l−1, respectively. Drainage was slightly reduced in the coffee-timber plantation. NO3leaching at 200 cm depth was about 27 ± 10 and 16 ± 7 kg N ha−1 yr−1 in unshaded and shaded coffee, respectively. In both plots, very low NO3 concentrations in soil solution at 200 cm depth (and in groundwater) were apparently due to NO3 adsorption in the subsoil but the duration of this process is not presently known. In these conventional coffee plantations, fertilization and agroforestry practices must be refined to match plant needs and limit potential NO3 contamination of subsoil and shallow soil water.  相似文献   
998.
999.
Adaptation to changing environmental conditions represents a challenge to parthenogenetic organisms, and until now, how phenotypic variants are generated in clones in response to the selection pressure of their environment remains poorly known. The obligatory parthenogenetic root‐knot nematode species Meloidogyne incognita has a worldwide distribution and is the most devastating plant‐parasitic nematode. Despite its asexual reproduction, this species exhibits an unexpected capacity of adaptation to environmental constraints, for example, resistant hosts. Here, we used a genomewide comparative hybridization strategy to evaluate variations in gene copy numbers between genotypes of M. incognita resulting from two parallel experimental evolution assays on a susceptible vs. resistant host plant. We detected gene copy number variations (CNVs) associated with the ability of the nematodes to overcome resistance of the host plant, and this genetic variation may reflect an adaptive response to host resistance in this parthenogenetic species. The CNV distribution throughout the nematode genome is not random and suggests the occurrence of genomic regions more prone to undergo duplications and losses in response to the selection pressure of the host resistance. Furthermore, our analysis revealed an outstanding level of gene loss events in nematode genotypes that have overcome the resistance. Overall, our results support the view that gene loss could be a common class of adaptive genetic mechanism in response to a challenging new biotic environment in clonal animals.  相似文献   
1000.
Decreased brain content of DHA, the most abundant long-chain n-3 polyunsaturated fatty acid (n-3 LCPUFA) in the brain, is accompanied by severe neurosensorial impairments linked to impaired neurotransmission and impaired brain glucose utilization. In the present study, we hypothesized that increasing n-3 LCPUFA intake at an early age may help to prevent or correct the glucose hypometabolism observed during aging and age-related cognitive decline. The effects of 12 months’ supplementation with n-3 LCPUFA on brain glucose utilization assessed by positron emission tomography was tested in young adult mouse lemurs (Microcebus murinus). Cognitive function was tested in parallel in the same animals. Lemurs supplemented with n-3 LCPUFA had higher brain glucose uptake and cerebral metabolic rate of glucose compared with controls in all brain regions. The n-3 LCPUFA-supplemented animals also had higher exploratory activity in an open-field task and lower evidence of anxiety in the Barnes maze.jlr Our results demonstrate for the first time in a nonhuman primate that n-3 LCPUFA supplementation increases brain glucose uptake and metabolism and concomitantly reduces anxiety.  相似文献   
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