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951.
Gary K. Chen Robert C. Millikan Esther M. John Christine B. Ambrosone Leslie Bernstein Wei Zheng Jennifer J. Hu Stephen J. Chanock Regina G. Ziegler Elisa V. Bandera Brian E. Henderson Christopher A. Haiman Daniel O. Stram 《PLoS genetics》2010,6(9)
We consider the feasibility of reusing existing control data obtained in genetic association studies in order to reduce costs for new studies. We discuss controlling for the population differences between cases and controls that are implicit in studies utilizing external control data. We give theoretical calculations of the statistical power of a test due to Bourgain et al (Am J Human Genet 2003), applied to the problem of dealing with case-control differences in genetic ancestry related to population isolation or population admixture. Theoretical results show that there may exist bounds for the non-centrality parameter for a test of association that places limits on study power even if sample sizes can grow arbitrarily large. We apply this method to data from a multi-center, geographically-diverse, genome-wide association study of breast cancer in African-American women. Our analysis of these data shows that admixture proportions differ by center with the average fraction of European admixture ranging from approximately 20% for participants from study sites in the Eastern United States to 25% for participants from West Coast sites. However, these differences in average admixture fraction between sites are largely counterbalanced by considerable diversity in individual admixture proportion within each study site. Our results suggest that statistical correction for admixture differences is feasible for future studies of African-Americans, utilizing the existing controls from the African-American Breast Cancer study, even if case ascertainment for the future studies is not balanced over the same centers or regions that supplied the controls for the current study. 相似文献
952.
Yacine Hemar Li Jiang Cheng Christine M. Oliver Luz Sanguansri Maryann Augustin 《Food biophysics》2010,5(2):120-127
The suitability of water-in-oil-in-water multiple emulsions to encapsulate resveratrol was assessed. Multiple emulsions were
prepared by emulsifying a primary emulsion (40 wt.%) in water containing 0.5 wt.% sodium caseinate and 0.1 M NaCl. Four primary
emulsions of canola oil (20 wt.%) stabilized by 8 wt.% polyglycerol polyricinoleate were chosen. The dispersed phase of the
primary emulsions contained 0.1 M NaCl and either water, 20 wt.% ethanol in water, 2.5 wt.% whey protein isolate (WPI) in
water, or 2.5 wt.% WPI and 5 wt.% gelatine in water. Resveratrol was incorporated into these primary emulsions at 0.25 wt.%
to give a final 0.02 wt.% resveratrol in the multiple emulsions. Slight increase in particle size with storage at 23 °C for
up to 2 weeks was observed. Further, less than 10% of the total encapsulated resveratrol is released to the external, continuous,
aqueous phase. This work demonstrates the potential of multiple emulsions to encapsulate resveratrol for food applications. 相似文献
953.
Christine A. Farthing Don E. Farthing Saisudha Koka Terri Larus Itaf Fakhry Lei Xi Rakesh C. Kukreja Domenic Sica Todd W.B. Gehr 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2010,878(28):2891-2895
A simple and sensitive high-performance liquid chromatographic (HPLC) method utilizing fluorescence detection was developed for the determination of the phosphodiesterase type 5 inhibitor tadalafil in mouse plasma. This method utilizes a simple sample preparation (protein precipitation) with high recovery of tadalafil (∼98%), which eliminates the need for an internal standard. For constituent separation, the method utilized a monolithic C18 column and a flow rate of 1.0 mL/min with a mobile phase gradient consisting of aqueous trifluoroacetic acid (0.1% TFA in deionized water pH 2.2, v/v) and acetonitrile. The method calibration was linear for tadalafil in mouse plasma from 100 to 2000 ng/mL (r > 0.999) with a detection limit of approximately 40 ng/mL. Component fluorescence detection was achieved using an excitation wavelength of 275 nm with monitoring of the emission wavelength at 335 nm. The intra-day and inter-day precision (relative standard deviation, RSD) values for tadalafil in mouse plasma were less than 14%, and the accuracy (percent error) was within −14% of the nominal concentration. The method was utilized on mouse plasma samples from research evaluating the potential cardioprotective effects of tadalafil on mouse heart tissue exposed to doxorubicin, a chemotherapeutic drug with reported cardiotoxic effects. 相似文献
954.
Helen Atterby James N. Aegerter Graham C. Smith Christine M. Conyers Theodore R. Allnutt Manuel Ruedi Alan D. MacNicoll 《European Journal of Wildlife Research》2010,56(1):67-81
The Daubenton’s bat is widespread and common in the UK and countries bordering the English Channel and North Sea. European
bat lyssavirus 2 (EBLV-2), a rabies virus, has been detected in Daubenton’s bats in the UK and continental Europe. Investigating
the relatedness of colonies and gene flow between these regions would allow regional estimates of the movement of Daubenton’s
bats and thus the potential for disease transmission. The genetic structure of the Daubenton’s bat in western Europe was investigated
by analysing variability at eight microsatellite loci. Genetic diversity was found to be high at all sites (H
E = 0.73–0.84), with little differentiation between bats sampled in the UK and continental Europe. Mantel tests indicated a
significant correlation between geographic distance and pair-wise F
ST (P = 0.000), between colonies sampled in Scotland and northern England. However, this was not continuous throughout the sampled
range, with evidence of panmixia within the area sampled in continental Europe. Assignment tests show no evidence that the
(potential) EBLV-2 sero-positive and virus positive bats were more likely to have originated from the continental rather than
UK populations. There is no sufficient significant genetic differentiation amongst most UK and continental colonies to conclude
that EBLV-2 is maintained in the UK by immigration. Results show that it is likely to be maintained at a low endemic level
within the UK. The relative genetic uniformity of UK and continental populations implies that there is no migration barrier
to EBLV-2, between these regions. 相似文献
955.
956.
A proteomic analysis was conducted to map the events during the initial stages of the interaction between the fungal pathogen Fusarium graminearum and the susceptible barley cultivar Scarlett. Quantification of fungal DNA demonstrated a sharp increase in fungal biomass in barley spikelets at 3 days after inoculation. This coincided with the appearance of discrete F. graminearum-induced proteolytic fragments of β-amylase. Based on these results, analysis of grain proteome changes prior to extensive proteolysis enabled identification of barley proteins responding early to infection by the fungus. In total, the intensity of 51 protein spots was significantly changed in F. graminearum-infected spikelets and all but one were identified. These included pathogenesis-related proteins, proteins involved in energy metabolism, secondary metabolism and protein synthesis. A single fungal protein of unknown function was identified. Quantitative real-time RT-PCR analysis of selected genes showed a correlation between high gene expression and detection of the corresponding proteins. Fungal genes encoding alkaline protease and endothiapepsin were expressed during 1-3 days after inoculation, making them candidates for generation of the observed β-amylase fragments. These fragments have potential to be developed as proteome-level markers for fungal infection that are also informative about grain protein quality. 相似文献
957.
Marianne Danielsen Marius C. Codrea Klaus L. Ingvartsen Nicolas C. Friggens Emøke Bendixen Christine M. Røntved 《Proteomics》2010,10(12):2240-2249
Intramammary infusion of lipopolysaccharide (LPS) in cows induces udder inflammation that partly simulates mastitis caused by infection with Gram‐negative bacteria. We have used this animal model to characterize the quantitiative response in the milk proteome during the time course before and immediately after the LPS challenge. Milk samples from three healthy cows collected 3 h before the LPS challenge were compared with milk samples collected 4 and 7 h after the LPS challenge, making it possible to describe the inflammatory response of individual cows. Quantitative protein profiles were obtained for 80 milk proteins, of which 49 profiles changed significantly for the three cows during LPS challenge. New information obtained in this study includes the quantified increase of apolipoproteins and other anti‐inflammatory proteins in milk, which are important for the cow's ability to balance the immune response, and the upregulation of both complement C3 and C4 indicates that more than one complement pathway could be activated during LPS‐induced mastitis. In the future, this analytical approach may provide valuable information about the differences in the ability of individual cows to resist and recover from mastitis. 相似文献
958.
3,6-Anhydro-1-(aryl or alkylamino)-1-deoxy-d-sorbitol derivatives have been prepared in four steps from isosorbide, a by-product from the starch industry. The inhibitory activities of these new compounds have been evaluated towards 13 glycosidases. A first lead-compound was identified, which inhibited β-N-acetylglucosaminidase from bovine kidney (82% inhibition at 1 mM). 相似文献
959.
960.