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21.
M Robertson 《Nature》1987,330(6147):420-421
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M Robertson 《Nature》1981,289(5798):532-533
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W. G. Christen R. W. Winters H. I. Cohen T. W. Robertson 《Cellular and molecular life sciences : CMLS》1979,35(10):1350-1351
Summary The adaptation field of the surround mechanism of X and Y retinal ganglion cells in the cat was assessed with variable size, unmodulated adapting spots. Both an on-inhibition measure and an off-discharge measure of surround gain was used. Results suggest that the surround mechanism in Y-cells is strongest in the receptive field middle but weak or nonexistent in the middle of X-cell receptive fields.Acknowledgment. This research was supported by Public Health Service grant No. EY 00701. 相似文献
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T. A. Robertson J. M. Papadimitriou M. D. Grounds 《Cellular and molecular life sciences : CMLS》1992,48(4):394-395
In this report we demonstrate for the first time that differentiating myogenic cells, geographically located between the plasmalemma and external lamina of myofibres in the satellite cell position3, can fuse directly with the plasmalemma of undamaged segments of mature myofibres. 相似文献
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Fritz JH Rojas OL Simard N McCarthy DD Hapfelmeier S Rubino S Robertson SJ Larijani M Gosselin J Ivanov II Martin A Casellas R Philpott DJ Girardin SE McCoy KD Macpherson AJ Paige CJ Gommerman JL 《Nature》2012,481(7380):199-203
The largest mucosal surface in the body is in the gastrointestinal tract, a location that is heavily colonized by microbes that are normally harmless. A key mechanism required for maintaining a homeostatic balance between this microbial burden and the lymphocytes that densely populate the gastrointestinal tract is the production and transepithelial transport of poly-reactive IgA (ref. 1). Within the mucosal tissues, B cells respond to cytokines, sometimes in the absence of T-cell help, undergo class switch recombination of their immunoglobulin receptor to IgA, and differentiate to become plasma cells. However, IgA-secreting plasma cells probably have additional attributes that are needed for coping with the tremendous bacterial load in the gastrointestinal tract. Here we report that mouse IgA(+) plasma cells also produce the antimicrobial mediators tumour-necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS), and express many molecules that are commonly associated with monocyte/granulocytic cell types. The development of iNOS-producing IgA(+) plasma cells can be recapitulated in vitro in the presence of gut stroma, and the acquisition of this multifunctional phenotype in vivo and in vitro relies on microbial co-stimulation. Deletion of TNF-α and iNOS in B-lineage cells resulted in a reduction in IgA production, altered diversification of the gut microbiota and poor clearance of a gut-tropic pathogen. These findings reveal a novel adaptation to maintaining homeostasis in the gut, and extend the repertoire of protective responses exhibited by some B-lineage cells. 相似文献
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Effect of ethylene on root extension of cereals 总被引:12,自引:0,他引:12