排序方式: 共有72条查询结果,搜索用时 15 毫秒
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P W Belfield 《BMJ (Clinical research ed.)》1988,296(6625):836-837
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Ciceron O. Yanez Alma R. Morales Xiling Yue Takeo Urakami Masanobu Komatsu Tero A. H. J?rvinen Kevin D. Belfield 《PloS one》2013,8(7)
Deep imaging within tissue (over 300 μm) at micrometer resolution has become possible with the advent of two-photon fluorescence microscopy (2PFM). The advantages of 2PFM have been used to interrogate endogenous and exogenous fluorophores in the skin. Herein, we employed the integrin (cell-adhesion proteins expressed by invading angiogenic blood vessels) targeting characteristics of a two-photon absorbing fluorescent probe to image new vasculature and fibroblasts up to ≈ 1600 μm within wound (neodermis)/granulation tissue in lesions made on the skin of mice. Reconstruction revealed three dimensional (3D) architecture of the vascular plexus forming at the regenerating wound tissue and the presence of a fibroblast bed surrounding the capillaries. Biologically crucial events, such as angiogenesis for wound healing, may be illustrated and analyzed in 3D on the whole organ level, providing novel tools for biomedical applications. 相似文献
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Annemarie MM Vlaar Angela EP Bouwmans Marinus JPG van Kroonenburgh Werner H Mess Selma C Tromp Piet GWM Wuisman Alfons GH Kessels Ania Winogrodzka Wim EJ Weber 《BMC neurology》2007,7(1):28
Background
Parkinson's disease (PD) is the second most common neurodegenerative disorder. As there is no definitive diagnostic test, its diagnosis is based on clinical criteria. Recently transcranial duplex scanning (TCD) of the substantia nigra in the brainstem has been proposed as an instrument to diagnose PD. We and others have found that TCD scanning of substantia nigra duplex is a relatively accurate diagnostic instrument in patients with parkinsonian symptoms. However, all studies on TCD so far have involved well-defined, later-stage PD patients, which will obviously lead to an overestimate of the diagnostic accuracy of TCD. 相似文献5.
Abstract. Woodland colonization on wetlands is considered to have a detrimental effect on their ecological value, even though detailed analysis of this process is lacking. This paper provides an evaluation of the ecological changes resulting from succession of poor fen (base‐poor mire) to willow wet woodland on Goss Moor NNR in Cornwall, UK. Different ages of willow carr were associated with eight understorey communities. During willow colonization, in the ground flora, there was a progressive decrease in poor fen species and an associated increase in woodland species, which appeared to be related to an increase in canopy cover and therefore shade. The most diverse community was found to be the most recent willow and was dominated by poor fen species. The oldest willow was the second most diverse and was associated with a reduction in poor fen species and an increase in woodland species. Architectural features were used successfully to assess the general condition and structure of willow. Tree height and DBH were identified as useful parameters to accurately assess willow age in the field. The implications of active intervention to remove willow in order to conserve the full range of communities within the hydrosere are discussed. 相似文献
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Genetic subtraction profiling identifies genes essential for <Emphasis Type="Italic">Arabidopsis</Emphasis>reproduction and reveals interaction between the female gametophyte and the maternal sporophyte 下载免费PDF全文
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Jiang C Mithani A Gan X Belfield EJ Klingler JP Zhu JK Ragoussis J Mott R Harberd NP 《Current biology : CB》2011,21(16):1385-1390
Multicellular organisms can be regenerated from totipotent differentiated somatic cell or nuclear founders [1-3]. Organisms regenerated from clonally related isogenic founders might a priori have been expected to be phenotypically invariant. However, clonal regenerant animals display variant phenotypes caused by defective epigenetic reprogramming of gene expression [2], and clonal regenerant plants exhibit poorly understood heritable phenotypic ("somaclonal") variation [4-7]. Here we show that somaclonal variation in regenerant Arabidopsis lineages is associated with genome-wide elevation in DNA sequence mutation rate. We also show that regenerant mutations comprise?a distinctive molecular spectrum of base substitutions, insertions, and deletions that probably results from decreased DNA repair fidelity. Finally, we show that while regenerant base substitutions are a likely major genetic cause of the somaclonal variation of regenerant Arabidopsis lineages, transposon movement is unlikely to contribute substantially to that variation. We conclude that the phenotypic variation of regenerant plants, unlike that of regenerant animals, is substantially due to DNA sequence mutation. 相似文献
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Wang X Morales AR Urakami T Zhang L Bondar MV Komatsu M Belfield KD 《Bioconjugate chemistry》2011,22(7):1438-1450
A two-photon absorbing (2PA) and aggregation-enhanced near-infrared (NIR) emitting pyran derivative, encapsulated in and stabilized by silica nanoparticles (SiNPs), is reported as a nanoprobe for two-photon fluorescence microscopy (2PFM) bioimaging that overcomes the fluorescence quenching associated with high chromophore loading. The new SiNP probe exhibited aggregate-enhanced emission producing nearly twice as strong a signal as the unaggregated dye, a 3-fold increase in two-photon absorption relative to the DFP in solution, and approximately 4-fold increase in photostability. The surface of the nanoparticles was functionalized with a folic acid (FA) derivative for folate-mediated delivery of the nanoprobe for 2PFM bioimaging. Surface modification of SiNPs with the FA derivative was supported by zeta potential variation and (1)H NMR spectral characterization of the SiNPs as a function of surface modification. In vitro studies using HeLa cells expressing a folate receptor (FR) indicated specific cellular uptake of the functionalized nanoparticles. The nanoprobe was demonstrated for FR-targeted one-photon in vivo imaging of HeLa tumor xenograft in mice upon intravenous injection of the probe. The FR-targeting nanoprobe not only exhibited highly selective tumor targeting but also readily extravasated from tumor vessels, penetrated into the tumor parenchyma, and was internalized by the tumor cells. Two-photon fluorescence microscopy bioimaging provided three-dimensional (3D) cellular-level resolution imaging up to 350 μm deep in the HeLa tumor. 相似文献
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Hughes RK Belfield EJ Ashton R Fairhurst SA Göbel C Stumpe M Feussner I Casey R 《FEBS letters》2006,580(17):4188-4194
We investigate the effects of detergent on the kinetics and oligomeric state of allene oxide synthase (AOS) from Arabidopsis thaliana (CYP74A1). We show that detergent-free CYP74A1 is monomeric and highly water soluble with dual specificity, but has relatively low activity. Detergent micelles promote a 48-fold increase in k(cat)/K(m) (to 5.9 x 10(7)M(-1)s(-1)) with concomitant changes in the spin state equilibrium of the haem-iron due to the binding of a single detergent micelle to the protein monomer, which is atypical of P450 enzymes. This mechanism is shown to be an important determinant of the substrate specificity of CYP74A1. CYP74A1 may be suited for structural resolution of the first plant cytochrome P450 and its 9-AOS activity and behaviour in vitro has implications for its role in planta. 相似文献
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