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排序方式: 共有772条查询结果,搜索用时 140 毫秒
1.
Highly localized changes in intracellular Ca2+ concentration ([Ca2+]i) can be evoked in neuronal growth cones; these are followed by local changes in filopodia. Focally applied electric fields evoked spatially restricted, high magnitude increases in growth cone [Ca2+]i. The earliest and greatest increases were localized to small regions within a growth cone. Such fields also produced characteristic changes in the disposition of filopodia: both filopodial length and number were significantly increased on the cathode side of growth cones. The requirement for extracellular Ca2+ and the strong correlation between the evoked rise in [Ca2+]i and the changes in filopodia (r = 0.98) indicate that cathode stimulation results in local Ca2+ influx, leading to locally increased [Ca2+]i and local changes in filopodial behavior. 相似文献
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Impaired cognitive functioning in alcoholics is widespread during the first months of detoxification. Between half and two thirds of abstinent alcoholics exhibit cognitive impairments during this period, with residual deficits persisting for years after detoxification in some patients. The most severe deficits have been observed in visuospatial abilities, perceptual-motor integration, abstract reasoning, and new learning. The most significant predictors of cognitive dysfunction in persons recovering from alcoholism are the time elapsed since the last drink and the person''s age. Surprisingly, the pattern and duration of a patient''s alcohol abuse are relatively weak determinants of neuropsychological impairment during abstinence. Research investigating the hypothesis that cognitive impairments may be related to alcoholic persons resuming drinking has yielded mixed results, but a higher level of neuropsychological functioning is associated with increased rates of completing treatment programs and with greater success in the work environment after discharge from treatment. The possibility of cognitive limitations should be taken into account in planning treatment programs for alcoholism. 相似文献
4.
Core Hunter: an algorithm for sampling genetic resources based on multiple genetic measures 总被引:1,自引:0,他引:1
Chris Thachuk José Crossa Jorge Franco Susanne Dreisigacker Marilyn Warburton Guy F Davenport 《BMC bioinformatics》2009,10(1):243
Background
Existing algorithms and methods for forming diverse core subsets currently address either allele representativeness (breeder's preference) or allele richness (taxonomist's preference). The main objective of this paper is to propose a powerful yet flexible algorithm capable of selecting core subsets that have high average genetic distance between accessions, or rich genetic diversity overall, or a combination of both. 相似文献5.
John C. Hando James D. Tucker Marsha Davenport James Tepperberg J. Nath 《Human genetics》1997,100(5-6):624-628
Studies on aneuploidy have shown that the X is the most frequently lost chromosome in females, and that the number of X chromosome-positive
micronuclei increases with age in women. Recently, we showed that the inactive X chromosome is incorporated preferentially
in micronuclei. The objectives of the current study were, firstly, to determine the incidence of X chromosome incorporation
into micronuclei in males and, secondly, to determine the incidence of X chromosome incorporation into micronuclei of females
with Turner syndrome. Blood samples were obtained from 18 male newborns and 35 normal adult males ranging in age from 22 to
79 years and from seven women with non-mosaic Turner syndrome aged 11–39 years. Isolated lymphocytes were cultured in the
presence of cytochalasin B and 2000 binucleated cells per subject were scored for micronuclei. Cells were then hybridized
with the biotinylated X centromere-specific probe, pBamX7, and visualized with fluorescein-conjugated avidin. All micronucleated
cells were relocated and evaluated for the presence or absence of the X chromosome. Of the 335 micronuclei observed, 6.6%
(22/335) contained an X chromosome. Analysis of variance shows a statistically significant increase, for both males and Turner
females, in the number of X chromosome-positive micronuclei with age (P < 0.001). These data also show that the X chromosome is included in micronuclei from males more often than would be expected
by chance (P < 0.005; χ2 analysis, 15 df). Here we show that there is a tenfold difference in the frequency of X chromosome-positive micronuclei in 46,XX females
compared to 46,XY males and 45,X females, providing further support to our previous finding that the X chromosome in micronuclei
is the inactive chromosome.
Received: 29 April 1997 / Accepted: 9 May 1997 相似文献
6.
Paul F. Jackson Timothy W. Davenport James F. Resch G. Scott Lehr Linda M. Pullan 《Bioorganic & medicinal chemistry letters》1991,1(12):751-756
The synthesis of a series of tricyclic quinoxalines is described. These compounds exhibit good affinity for both the strychnine-insensitive glycine site of the NMDA receptor and the AMPA receptor. 相似文献
7.
F Zeidán-Chuliá B-HN de Oliveira A B Salmina M F Casanova D P Gelain M Noda A Verkhratsky J CF Moreira 《Cell death & disease》2014,5(5):e1250
Autism and Alzheimer''s disease (AD) are, respectively, neurodevelopmental and degenerative diseases with an increasing epidemiological burden. The AD-associated amyloid-β precursor protein-α has been shown to be elevated in severe autism, leading to the ‘anabolic hypothesis'' of its etiology. Here we performed a focused microarray analysis of genes belonging to NOTCH and WNT signaling cascades, as well as genes related to AD and apoptosis pathways in cerebellar samples from autistic individuals, to provide further evidence for pathological relevance of these cascades for autism. By using the limma package from R and false discovery rate, we demonstrated that 31% (116 out of 374) of the genes belonging to these pathways displayed significant changes in expression (corrected P-values <0.05), with mitochondria-related genes being the most downregulated. We also found upregulation of GRIN1, the channel-forming subunit of NMDA glutamate receptors, and MAP3K1, known activator of the JNK and ERK pathways with anti-apoptotic effect. Expression of PSEN2 (presinilin 2) and APBB1 (or F65) were significantly lower when compared with control samples. Based on these results, we propose a model of NMDA glutamate receptor-mediated ERK activation of α-secretase activity and mitochondrial adaptation to apoptosis that may explain the early brain overgrowth and disruption of synaptic plasticity and connectome in autism. Finally, systems pharmacology analyses of the model that integrates all these genes together (NOWADA) highlighted magnesium (Mg2+) and rapamycin as most efficient drugs to target this network model in silico. Their potential therapeutic application, in the context of autism, is therefore discussed. 相似文献
8.
Nir Dover Jason R. Barash Karen K. Hill Karen W. Davenport Hazuki Teshima Gary Xie Stephen S. Arnon 《PloS one》2013,8(4)
Sanger and shotgun sequencing of Clostridium botulinum strain Af84 type Af and its botulinum neurotoxin gene (bont) clusters identified the presence of three bont gene clusters rather than the expected two. The three toxin gene clusters consisted of bont subtypes A2, F4 and F5. The bont/A2 and bont/F4 gene clusters were located within the chromosome (the latter in a novel location), while the bont/F5 toxin gene cluster was located within a large 246 kb plasmid. These findings are the first identification of a C. botulinum strain that contains three botulinum neurotoxin gene clusters. 相似文献
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