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排序方式: 共有563条查询结果,搜索用时 15 毫秒
61.
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Laussmann MA Passante E Hellwig CT Tomiczek B Flanagan L Prehn JH Huber HJ Rehm M 《The Journal of biological chemistry》2012,287(18):14402-14411
64.
Ruth Joy Mitchell Adian M. Keith Jackie M. Potts Jasmine Ross Eileen Reid Lorna A. Dawson 《Plant and Soil》2012,352(1-2):65-84
Aim
To test if there is an interactive effect between tree and understory species on the soil microbial community (SMC), community level physiological profiles (CLPP) and soil micro-fauna.Method
A replicate pot experiment with five sapling tree species (Betula pendula, Betula pubescens, Sorbus aucuparia, Quercus petraea and Pinus sylvestris) and a no-tree treatment with and without Calluna vulgaris was established. After 21?months samples were taken for phospholipid fatty acid (PLFA) analysis, CLPP and soil microfauna assessment.Results
There was an interactive effect of tree species and Calluna on the SMC, CLPP and nematode densities. Calluna addition changed the SMC composition (increase in fungal PLFAs) and the CLPP (lower utilisation of most carbon sources but greater utilisation of phenolic acids). A multivariate test for homogeneity of dispersion showed that while Calluna addition resulted in the presence of an altered microbial composition, it did not result in there being less variability among the samples with Calluna than among the samples without Calluna. Sapling trees with Calluna present grew less well than trees without Calluna. Structural equation modelling showed that it is possible that Calluna had an indirect effect on the SMC via below-ground tree biomass as well as a direct effect.Conclusion
Interactions between trees and understory vegetation can impact on the composition of soil biota and their activity. 相似文献65.
66.
Harries LW Pilling LC Hernandez LD Bradley-Smith R Henley W Singleton AB Guralnik JM Bandinelli S Ferrucci L Melzer D 《Aging cell》2012,11(2):262-268
Declining muscle strength is a core feature of aging. Several mechanisms have been postulated, including CCAAT/enhancer-binding protein-beta (C/EBP-β)-triggered macrophage-mediated muscle fiber regeneration after micro-injury, evidenced in a mouse model. We aimed to identify in vivo circulating leukocyte gene expression changes associated with muscle strength in the human adult population. We undertook a genome-wide expression microarray screen, using peripheral blood RNA samples from InCHIANTI study participants (aged 30 and 104). Logged expression intensities were regressed with muscle strength using models adjusted for multiple confounders. Key results were validated by real-time PCR. The Short Physical Performance Battery (SPPB) score tested walk speed, chair stand, and balance. CEBPB expression levels were associated with muscle strength (β coefficient = 0.20560, P = 1.03*10(-6), false discovery rate q = 0.014). The estimated handgrip strength in 70-year-old men in the lowest CEBPB expression tertile was 35.2 kg compared with 41.2 kg in the top tertile. CEBPB expression was also associated with hip, knee, ankle, and shoulder strength and the SPPB score (P = 0.018). Near-study-wide associations were also noted for TGF-β3 (P = 3.4*10(-5) , q = 0.12) and CEBPD expression (P = 9.7*10(-5) , q = 0.18) but not for CEBPA expression. We report here a novel finding that raised CEBPB expression in circulating leukocyte-derived RNA samples in vivo is associated with greater muscle strength and better physical performance in humans. This association may be consistent with mouse model evidence of CEBPB-triggered muscle repair: if this mechanism is confirmed, it may provide a target for intervention to protect and enhance aging muscle. 相似文献
67.
ML De Leoz SC Gaerlan JS Strum LM Dimapasoc M Mirmiran DJ Tancredi JT Smilowitz KM Kalanetra DA Mills JB German CB Lebrilla MA Underwood 《Journal of proteome research》2012,11(9):4662-4672
Breast milk is the ideal nutrition for term infants but must be supplemented to provide adequate growth for most premature infants. Human milk oligosaccharides (HMOs) are remarkably abundant and diverse in breast milk and yet provide no nutritive value to the infant. HMOs appear to have at least two major functions: prebiotic activity (stimulation of the growth of commensal bacteria in the gut) and protection against pathogens. Investigations of HMOs in milk from women delivering preterm have been limited. We present the first detailed mass spectrometric analysis of the fucosylation and sialylation in HMOs in serial specimens of milk from 15 women delivering preterm and 7 women delivering at term using nanohigh performance liquid chromatography chip/time-of-flight mass spectrometry. A mixed-effects model with Levene's test was used for the statistical analyses. We find that lacto-N-tetraose, a core HMO, is both more abundant and more highly variable in the milk of women delivering preterm. Furthermore, fucosylation in preterm milk is not as well regulated as in term milk, resulting in higher within and between mother variation in women delivering preterm vs term. Of particular clinical interest, the α1,2-linked fucosylated oligosaccharide 2'-fucosyllactose, an indicator of secretor status, is not consistently present across lactation of several mothers that delivered preterm. The immaturity of HMO production does not appear to resolve over the time of lactation and may have relevance to the susceptibility of premature infants to necrotizing enterocolitis, late onset sepsis, and related neurodevelopmental impairments. 相似文献
68.
Lorna Gallagher Rebecca A. Owens Stephen K. Dolan Grainne O'Keeffe Markus Schrettl Kevin Kavanagh Gary W. Jones Sean Doyle 《Eukaryotic cell》2012,11(10):1226-1238
The function of a number of genes in the gliotoxin biosynthetic cluster (gli) in Aspergillus fumigatus remains unknown. Here, we demonstrate that gliK deletion from two strains of A. fumigatus completely abolished gliotoxin biosynthesis. Furthermore, exogenous H2O2 (1 mM), but not gliotoxin, significantly induced A. fumigatus gliK expression (P = 0.0101). While both mutants exhibited significant sensitivity to both exogenous gliotoxin (P < 0.001) and H2O2 (P < 0.01), unexpectedly, exogenous gliotoxin relieved H2O2-induced growth inhibition in a dose-dependent manner (0 to 10 μg/ml). Gliotoxin-containing organic extracts derived from A. fumigatus ATCC 26933 significantly inhibited (P < 0.05) the growth of the ΔgliK26933 deletion mutant. The A. fumigatus ΔgliK26933 mutant secreted metabolites, devoid of disulfide linkages or free thiols, that were detectable by reverse-phase high-performance liquid chromatography and liquid chromatography-mass spectrometry with m/z 394 to 396. These metabolites (m/z 394 to 396) were present at significantly higher levels in the culture supernatants of the A. fumigatus ΔgliK26933 mutant than in those of the wild type (P = 0.0024 [fold difference, 24] and P = 0.0003 [fold difference, 9.6], respectively) and were absent from A. fumigatus ΔgliG. Significantly elevated levels of ergothioneine were present in aqueous mycelial extracts of the A. fumigatus ΔgliK26933 mutant compared to the wild type (P < 0.001). Determination of the gliotoxin uptake rate revealed a significant difference (P = 0.0045) between that of A. fumigatus ATCC 46645 (9.3 pg/mg mycelium/min) and the ΔgliK46645 mutant (31.4 pg/mg mycelium/min), strongly suggesting that gliK absence and the presence of elevated ergothioneine levels impede exogenously added gliotoxin efflux. Our results confirm a role for gliK in gliotoxin biosynthesis and reveal new insights into gliotoxin functionality in A. fumigatus. 相似文献
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T Kirchhoff MM Gaudet AC Antoniou L McGuffog MK Humphreys AM Dunning SE Bojesen BG Nordestgaard H Flyger D Kang KY Yoo DY Noh SH Ahn T Dork P Schürmann JH Karstens P Hillemanns FJ Couch J Olson C Vachon X Wang A Cox I Brock G Elliott MW Reed B Burwinkel A Meindl H Brauch U Hamann YD Ko;GENICA Network A Broeks MK Schmidt LJ Van 't Veer LM Braaf N Johnson O Fletcher L Gibson J Peto C Turnbull S Seal A Renwick N Rahman PE Wu JC Yu CN Hsiung CY Shen MC Southey JL Hopper F Hammet T Van Dorpe 《PloS one》2012,7(6):e35706
Recently, a locus on chromosome 6q22.33 (rs2180341) was reported to be associated with increased breast cancer risk in the Ashkenazi Jewish (AJ) population, and this association was also observed in populations of non-AJ European ancestry. In the present study, we performed a large replication analysis of rs2180341 using data from 31,428 invasive breast cancer cases and 34,700 controls collected from 25 studies in the Breast Cancer Association Consortium (BCAC). In addition, we evaluated whether rs2180341 modifies breast cancer risk in 3,361 BRCA1 and 2,020 BRCA2 carriers from 11 centers in the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). Based on the BCAC data from women of European ancestry, we found evidence for a weak association with breast cancer risk for rs2180341 (per-allele odds ratio (OR)?=?1.03, 95% CI 1.00-1.06, p?=?0.023). There was evidence for heterogeneity in the ORs among studies (I(2)?=?49.3%; p?=?<0.004). In CIMBA, we observed an inverse association with the minor allele of rs2180341 and breast cancer risk in BRCA1 mutation carriers (per-allele OR?=?0.89, 95%CI 0.80-1.00, p?=?0.048), indicating a potential protective effect of this allele. These data suggest that that 6q22.33 confers a weak effect on breast cancer risk. 相似文献