排序方式: 共有55条查询结果,搜索用时 46 毫秒
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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4.
Kole T. Roybal Emily M. Mace Danielle J. Clark Alan D. Leard Andrew Herman Paul Verkade Jordan S. Orange Christoph Wülfing 《PloS one》2015,10(8)
Dynamic subcellular distributions of signaling system components are critical regulators of cellular signal transduction through their control of molecular interactions. Understanding how signaling activity depends on such distributions and the cellular structures driving them is required for comprehensive insight into signal transduction. In the activation of primary murine T cells by antigen presenting cells (APC) signaling intermediates associate with various subcellular structures, prominently a transient, wide, and actin-associated lamellum extending from an interdigitated T cell:APC interface several micrometers into the T cell. While actin dynamics are well established as general regulators of cellular organization, their role in controlling signaling organization in primary T cell:APC couples and the specific cellular structures driving it is unresolved. Using modest interference with actin dynamics with a low concentration of Jasplakinolide as corroborated by costimulation blockade we show that T cell actin preferentially controls lamellal signaling localization and activity leading downstream to calcium signaling. Lamellal localization repeatedly related to efficient T cell function. This suggests that the transient lamellal actin matrix regulates T cell signaling associations that facilitate T cell activation. 相似文献
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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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BŁAŻEJ BERKOWSKI CHRISTIAN KLUG 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2012,45(1):24-33
Berkowski, B & Klug, C. 2011: Lucky rugose corals on crinoid stems: unusual examples of subepidermal epizoans from the Devonian of Morocco. Lethaia, Vol. 45, pp. 24–33. In the fossil record, evidence for true epizoans, i.e. living animals inhabiting other living host‐animals, is rather rare. A host reaction is usually needed to proof the syn vivo‐settling of the epizoan. Herein, we provide a first report of such an epizoan biocoenosis from various strata of the Early Devonian of Hamar Laghdad, the world‐renowned Moroccan mud‐mound locality. In this case, solitary rugose corals settled as larvae on crinoid stems, perhaps at a spot where the epidermis was missing for some reason (injury, disease). Both the crinoid and the coral began to grow around each other. By doing so, the affected crinoid columnals formed a swelling, where ultimately only an opening slightly larger than the coral orifice remained. We discuss both macroecological and small‐scale synecological aspects of this biocoenosis. The coral profited from its elevated home because it reached into more rapid currents providing the polyp with more food than at the densely populated seafloor, which was probably covered by a coral‐meadow around the mounds and hydrothermal vents. □Corals, crinoids, Early Devonian, epizoans, Morocco, Rugosa. 相似文献
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Annemarie MM Vlaar Marinus JPG van Kroonenburgh Alfons GH Kessels Wim EJ Weber 《BMC neurology》2007,7(1):27
Background
Parkinson's disease (PD) is the second most common neurodegenerative disorder. One of the most widely used techniques to diagnose PD is a Single Photon Emission Computer Tomography (SPECT) scan to visualise the integrity of the dopaminergic pathways in the brain. Despite this there remains some discussion on the value of SPECT in the differential diagnosis of PD. We did a meta-analysis of all the existing literature on the diagnostic accuracy of both pre- and post-synaptic SPECT imaging in the differential diagnosis of PD. 相似文献9.
Roybal CN Yang S Sun CW Hurtado D Vander Jagt DL Townes TM Abcouwer SF 《The Journal of biological chemistry》2004,279(15):14844-14852
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Denniston DJ Thomas MG Kane KK Roybal CN Canales L Hallford DM Remmenga MD Hawkins DE 《Animal reproduction science》2003,78(1-2):25-31
Objectives were to determine if neuropeptide Y (NPY) had direct effects GnRH induced secretion of LH from the anterior pituitary gland, and if endogenous steroids modulated the effect of NPY. To accomplish these objectives, 15 Hereford heifers were assigned to one of three ovarian status groups: follicular, luteal, or ovariectomized. One animal from each of the three ovarian status groups was slaughtered on each of 5 days and anterior pituitary gland harvested. Anterior pituitary gland cells within ovarian status were equally distributed and randomly assigned to one of three cell culture treatments: no NPY or GnRH (control), 10 nM GnRH, or 100 nM NPY+10 nM GnRH. Anterior pituitary cell cultures were incubated with or without NPY for 4 h and further incubated for an additional 2 h with or without GnRH and supernatant collected for quantification of LH. Treatment of anterior pituitary cell cultures with GnRH or GnRH+NPY did not affect LH release in cultures obtained from follicular (S.E.=5%; P=0.58) or ovariectomized (S.E.=7%; P=0.22) heifers. Both GnRH and GnRH+NPY increased LH release from anterior pituitary cell cultures from heifers in the luteal phase (S.E.=14%; P < or = 0.05) compared to control cultures. Cultures from luteal phase heifers treated with GnRH did not differ from those treated with GnRH+NPY (P=0.34). These data provide evidence to suggest that effects of NPY on LH release may occur primarily at the level of the hypothalamus. 相似文献