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排序方式: 共有603条查询结果,搜索用时 46 毫秒
21.
Susanna A. Wood Xavier Pochon Olivier Laroche Ulla von Ammon Janet Adamson Anastasija Zaiko 《Molecular ecology resources》2019,19(6):1407-1419
Targeted species‐specific and community‐wide molecular diagnostics tools are being used with increasing frequency to detect invasive or rare species. Few studies have compared the sensitivity and specificity of these approaches. In the present study environmental DNA from 90 filtered seawater and 120 biofouling samples was analyzed with quantitative PCR (qPCR), droplet digital PCR (ddPCR) and metabarcoding targeting the cytochrome c oxidase I (COI) and 18S rRNA genes for the Mediterranean fanworm Sabella spallanzanii. The qPCR analyses detected S. spallanzanii in 53% of water and 85% of biofouling samples. Using ddPCR S. spallanzanii was detected in 61% of water of water and 95% of biofouling samples. There were strong relationships between COI copy numbers determined via qPCR and ddPCR (water R2 = 0.81, p < .001, biofouling R2 = 0.68, p < .001); however, qPCR copy numbers were on average 125‐fold lower than those measured using ddPCR. Using metabarcoding there was higher detection in water samples when targeting the COI (40%) compared to 18S rRNA (5.4%). The difference was less pronounced in biofouling samples (25% COI, 29% 18S rRNA). Occupancy modelling showed that although the occupancy estimate was higher for biofouling samples (ψ = 1.0), higher probabilities of detection were derived for water samples. Detection probabilities of ddPCR (1.0) and qPCR (0.93) were nearly double metabarcoding (0.57 to 0.27 marker dependent). Studies that aim to detect specific invasive or rare species in environmental samples should consider using targeted approaches until a detailed understanding of how community and matrix complexity, and primer biases affect metabarcoding data. 相似文献
22.
JG Hansen W Gao J Dupuis GT O’Connor W Tang M Kowgier A Sood SA Gharib LJ Palmer M Fornage SR Heckbert BM Psaty SL Booth SUNLIGHT Consortium Patricia A Cassano 《Respiratory research》2015,16(1)
Background
Vitamin D is associated with lung function in cross-sectional studies, and vitamin D inadequacy is hypothesized to play a role in the pathogenesis of chronic obstructive pulmonary disease. Further data are needed to clarify the relation between vitamin D status, genetic variation in vitamin D metabolic genes, and cross-sectional and longitudinal changes in lung function in healthy adults.Methods
We estimated the association between serum 25-hydroxyvitamin D [25(OH)D] and cross-sectional forced expiratory volume in the first second (FEV1) in Framingham Heart Study (FHS) Offspring and Third Generation participants and the association between serum 25(OH)D and longitudinal change in FEV1 in Third Generation participants using linear mixed-effects models. Using a gene-based approach, we investigated the association between 241 SNPs in 6 select vitamin D metabolic genes in relation to longitudinal change in FEV1 in Offspring participants and pursued replication of these findings in a meta-analyzed set of 4 independent cohorts.Results
We found a positive cross-sectional association between 25(OH)D and FEV1 in FHS Offspring and Third Generation participants (P = 0.004). There was little or no association between 25(OH)D and longitudinal change in FEV1 in Third Generation participants (P = 0.97). In Offspring participants, the CYP2R1 gene, hypothesized to influence usual serum 25(OH)D status, was associated with longitudinal change in FEV1 (gene-based P < 0.05). The most significantly associated SNP from CYP2R1 had a consistent direction of association with FEV1 in the meta-analyzed set of replication cohorts, but the association did not reach statistical significance thresholds (P = 0.09).Conclusions
Serum 25(OH)D status was associated with cross-sectional FEV1, but not longitudinal change in FEV1. The inconsistent associations may be driven by differences in the groups studied. CYP2R1 demonstrated a gene-based association with longitudinal change in FEV1 and is a promising candidate gene for further studies.Electronic supplementary material
The online version of this article (doi:10.1186/s12931-015-0238-y) contains supplementary material, which is available to authorized users. 相似文献23.
Melissa Richard-Greenblatt Horacio Bach John Adamson Sandra Pe?a-Diaz Wu Li Adrie J. C. Steyn Yossef Av-Gay 《The Journal of biological chemistry》2015,290(38):23064-23076
Ergothioneine (EGT) is synthesized in mycobacteria, but limited knowledge exists regarding its synthesis, physiological role, and regulation. We have identified Rv3701c from Mycobacterium tuberculosis to encode for EgtD, a required histidine methyltransferase that catalyzes first biosynthesis step in EGT biosynthesis. EgtD was found to be phosphorylated by the serine/threonine protein kinase PknD. PknD phosphorylates EgtD both in vitro and in a cell-based system on Thr213. The phosphomimetic (T213E) but not the phosphoablative (T213A) mutant of EgtD failed to restore EGT synthesis in a ΔegtD mutant. The findings together with observed elevated levels of EGT in a pknD transposon mutant during in vitro growth suggests that EgtD phosphorylation by PknD negatively regulates EGT biosynthesis. We further showed that EGT is required in a nutrient-starved model of persistence and is needed for long term infection of murine macrophages. 相似文献
24.
Yimei Li Matt Hall Brian T. Fisher Alix E. Seif Yuan-Shung Huang Rochelle Bagatell Kelly D. Getz Todd A. Alonzo Robert B. Gerbing Lillian Sung Peter C. Adamson Alan Gamis Richard Aplenc 《PloS one》2015,10(11)
Purpose
Clinical trials data from National Cancer Institute (NCI)-funded cooperative oncology group trials could be enhanced by merging with external data sources. Merging without direct patient identifiers would provide additional patient privacy protections. We sought to develop and validate a matching algorithm that uses only indirect patient identifiers.Methods
We merged the data from two Phase III Children’s Oncology Group (COG) trials for de novo acute myeloid leukemia (AML) with the Pediatric Health Information Systems (PHIS). We developed a stepwise matching algorithm that used indirect identifiers including treatment site, gender, birth year, birth month, enrollment year and enrollment month. Results from the stepwise algorithm were compared against the direct merge method that used date of birth, treatment site, and gender. The indirect merge algorithm was developed on AAML0531 and validated on AAML1031.Results
Of 415 patients enrolled on the AAML0531 trial at PHIS centers, we successfully matched 378 (91.1%) patients using the indirect stepwise algorithm. Comparison to the direct merge result suggested that 362 (95.7%) matches identified by the indirect merge algorithm were concordant with the direct merge result. When validating the indirect stepwise algorithm using the AAML1031 trial, we successfully matched 157 out of 165 patients (95.2%) and 150 (95.5%) of the indirectly merged matches were concordant with the directly merged matches.Conclusions
These data demonstrate that patients enrolled on COG clinical trials can be successfully merged with PHIS administrative data using a stepwise algorithm based on indirect patient identifiers. The merged data sets can be used as a platform for comparative effectiveness and cost effectiveness studies. 相似文献25.
H. G. Adamson 《BMJ (Clinical research ed.)》1931,1(3658):284-285
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28.
Jeannie Hwang Crista Adamson David Butler David R. Janero Alexandros Makriyannis Ben A. Bahr 《Life sciences》2010,86(15-16):615-623
AimsThis review posits that fatty acid amide hydrolase (FAAH) inhibition has therapeutic potential against neuropathological states including traumatic brain injury; Alzheimer's, Huntington's, and Parkinson's diseases; and stroke.Main methodsThis proposition is supported by data from numerous in vitro and in vivo experiments establishing metabolic and pharmacological contexts for the neuroprotective role of the endogenous cannabinoid (“endocannabinoid”) system and selective FAAH inhibitors.Key findingsThe systems biology of endocannabinoid signaling involves two main cannabinoid receptors, the principal endocannabinoid lipid mediators N-arachidonoylethanolamine (“anandamide”) (AEA) and 2-arachidonoyl glycerol (2-AG), related metabolites, and the proteins involved in endocannabinoid biosynthesis, biotransformation, and transit. The endocannabinoid system is capable of activating distinct signaling pathways on-demand in response to pathogenic events or stimuli, thereby enhancing cell survival and promoting tissue repair. Accumulating data suggest that endocannabinoid system modulation at discrete targets is a promising pharmacotherapeutic strategy for treating various medical conditions. In particular, neuronal injury activates cannabinoid signaling in the central nervous system as an intrinsic neuroprotective response. Indirect potentiation of this salutary response through pharmacological inhibition of FAAH, an endocannabinoid-deactivating enzyme, and consequent activation of signaling pathways downstream from cannabinoid receptors have been shown to promote neuronal maintenance and function.SignificanceThis therapeutic modality has the potential to offer site- and event-specific neuroprotection under conditions where endocannabinoids are being produced as part of a physiological protective mechanism. In contrast, direct application of cannabinoid receptor agonists to the central nervous system may activate CB receptors indiscriminately and invite unwanted psychotrophic effects. 相似文献
29.
Hoon-Ki Sung Kyung-Oh Doh Joe Eun Son Jin Gyoon Park Yunui Bae Soojeong Choi Seana Mary Lunney Nelson Rebecca Cowling Kristina Nagy Iacovos P. Michael Gou Young Koh S. Lee Adamson Tony Pawson Andras Nagy 《Cell metabolism》2013,17(1):61-72
Highlights? Two-way modulations of adipose VEGF were generated with aP2-Cre transgene ? Adipose VEGF KO reduces vasculature, increases hypoxia and inflammation in fat ? Adipose VEGF KO accelerates the development of metabolic disease in high-fat diet ? Induced adipose VEGF has opposite effect on fat and restores metabolic homeostasis 相似文献
30.
Susan E. Ward Richard D. Bardgett Niall P. McNamara John K. Adamson Nick J. Ostle 《Ecosystems》2007,10(7):1069-1083
Abstract
Using a 50-year-old field experiment, we investigated the effects of the long-term land management practices of repeated burning
and grazing on peatland vegetation and carbon dynamics (C). Plant community composition, C stocks in soils and vegetation,
and C fluxes of CO2, CH4 and DOC, were measured over an 18-month period. We found that both burning and grazing reduced aboveground C stocks, and
that burning reduced C stocks in the surface peat. Both burning and grazing strongly affected vegetation community composition,
causing an increase in graminoids and a decrease in ericoid subshrubs and bryophytes relative to unburned and ungrazed controls;
this effect was especially pronounced in burned treatments. Soil microbial properties were unaffected by grazing and showed
minor responses to burning, in that the C:N ratio of the microbial biomass increased in burned relative to unburned treatments.
Increases in the gross ecosystem CO2 fluxes of respiration and photosynthesis were observed in burned and grazed treatments relative to controls. Here, the greatest
effects were seen in the burning treatment, where the mean increase in gross fluxes over the experimental period was greater
than 40%. Increases in gross CO2 fluxes were greatest during the summer months, suggesting an interactive effect of land use and climate on ecosystem C cycling.
Collectively, our results indicate that long-term management of peatland has marked effects on ecosystem C dynamics and CO2 flux, which are primarily related to changes in vegetation community structure. 相似文献