Search results for "Priming"
showing 10 items of 280 documents
Changes in the Transcriptome Profiles of Human Amnion-Derived Mesenchymal Stromal/Stem Cells Induced by Three-Dimensional Culture: A Potential Primin…
2022
Mesenchymal stromal/stem cells (MSCs) are believed to function in vivo as a homeostatic tool that shows therapeutic properties for tissue repair/regeneration. Conventionally, these cells are expanded in two-dimensional (2D) cultures, and, in that case, MSCs undergo genotypic/phenotypic changes resulting in a loss of their therapeutic capabilities. Moreover, several clinical trials using MSCs have shown controversial results with moderate/insufficient therapeutic responses. Different priming methods were tested to improve MSC effects, and three-dimensional (3D) culturing techniques were also examined. MSC spheroids display increased therapeutic properties, and, in this context, it is crucial…
Second-generation Langerhans cells originating from epidermal precursors are essential for CD8+ T cell priming.
2014
Abstract In vivo studies questioned the ability of Langerhans cells (LCs) to mediate CD8+ T cell priming. To address this issue, we used intradermal immunization with plasmid DNA, a system in which activation of CD8+ T cells depends on delayed kinetics of Ag presentation. We found that dendritic cells (DCs) located in the skin at the time of immunization have limited ability to activate CD8+ T cells. This activity was mediated by a second generation of DCs that differentiated in the skin several days after immunization, as well as by lymph node–resident DCs. Intriguingly, CD8+ T cell responses were not affected following treatment with clodronate liposomes, immunization of CCR2−/− mice, or …
Mast cells counteract regulatory T-cell suppression through interleukin-6 and OX40/OX40L axis toward Th17-cell differentiation
2009
Abstract The development of inflammatory diseases implies inactivation of regulatory T (Treg) cells through mechanisms that still are largely unknown. Here we showed that mast cells (MCs), an early source of inflammatory mediators, are able to counteract Treg inhibition over effector T cells. To gain insight into the molecules involved in their interplay, we set up an in vitro system in which all 3 cellular components were put in contact. Reversal of Treg suppression required T cell–derived interleukin-6 (IL-6) and the OX40/OX40L axis. In the presence of activated MCs, concomitant abundance of IL-6 and paucity of Th1/Th2 cytokines skewed Tregs and effector T cells into IL-17–producing T cel…
The Influence of Hierarchical Masks on Masked Repetition Priming: Evidence From Event-Related Potential Investigation
2019
The discussion about relationship between prime and target has contributed to the mechanism of priming effect and object recognition. Nevertheless, the role of relationship between mask and target in those cognitive processes remains unquestioned. In the present study, we aim to investigate how mask-target hierarchical relationship may affect word priming and familiarity, by using the masked repetition paradigm and manipulating three hierarchical relationship between mask and target. It is hypothesized that a closer hierarchical relationship between mask and target is associated with a higher mask target similarity, and thereby it leads to a worse recognition performance. Our behavioral res…
Event-related brain potentials of masked repetition and semantic priming while listening to sentences.
2012
We combined for the first time electrophysiological measures and masked priming technique in sentential context, by setting up a cross-modal masked priming paradigm involving the auditory presentation of sentences. ERPs were time-locked to an auditorily presented word that was preceded by a repeated, related or unrelated pattern masked prime. We registered a two-way N400-difference between unrelated and related/repeated primes, followed by a late positive component (LPC) for repetition priming. Related primes appear to facilitate the lexical-semantic processing of the target to the same extent repeated primes do (equally attenuated N400). Repetition priming exerts additional demands (LPC), …
Are coffee and toffee served in a cup? Ortho-phonologically mediated associative priming.
2008
We report three masked associative priming experiments with the lexical decision task that explore whether the initial activation flow of a visually presented word activates the semantic representations of that word's orthographic/phonological neighbours. The predictions of cascades and serial/modular models of lexical processing differ widely in this respect. Using a masked priming paradigm (stimulus onset asynchrony, SOA = 50 ms), words preceded by ortho-phonologically mediated associated “neighbours” ( oveja–MIEL, the Spanish for sheep–HONEY; note that oveja is a phonological neighbour of abeja, the Spanish for bee) were recognized more rapidly than words preceded by an unrelated word p…
A challenging dissociation in masked identity priming with the lexical decision task.
2013
Abstract The masked priming technique has been used extensively to explore the early stages of visual-word recognition. One key phenomenon in masked priming lexical decision is that identity priming is robust for words, whereas it is small/unreliable for nonwords. This dissociation has usually been explained on the basis that masked priming effects are lexical in nature, and hence there should not be an identity prime facilitation for nonwords. We present two experiments whose results are at odds with the assumption made by models that postulate that identity priming is purely lexical, and also challenge the assumption that word and nonword responses are based on the same information. Our e…
Non-cognate translation priming effects in the same–different task: evidence for the impact of “higher level” information
2015
Norris and colleagues have proposed that priming effects observed in the masked prime same–different task are based solely on pre-lexical orthographic information. This proposal was evaluated by examining translation priming effects from non-cognate translation equivalents using both Spanish–English and Japanese–English bilinguals in the same–different task. Although no priming was observed for Spanish–English bilinguals, who also produced very little translation priming in a lexical decision task, significant priming was observed for Japanese–English bilinguals. These results indicate that, although most of the priming in the same–different task has an orthographic basis, other types of pr…
Facilitation versus inhibition in the masked priming same-different matching task.
2011
In the past years, growing attention has been devoted to the masked priming same–different task introduced by Norris and Kinoshita (2008, Journal of Experimental Psychology: General). However, a number of researchers have raised concerns on the nature of the cognitive processes underlying this task—in particular the suspicion that masked priming effects in this task are mostly inhibitory in nature and may be affected by probe–prime contingency. To examine the pattern of facilitative/inhibitory priming effects in this task, we conducted two experiments with an incremental priming paradigm using four stimulus–onset asynchronies (13, 27, 40, and 53 ms). Experiment 1 was conducted under a pred…
Priming of plant resistance by natural compounds. Hexanoic acid as a model
2014
Some alternative control strategies of currently emerging plant diseases are based on the use of resistance inducers. This review highlights the recent advances made in the characterization of natural compounds that induce resistance by a priming mechanism. These include vitamins, chitosans, oligogalacturonides, volatile organic compounds, azelaic and pipecolic acid, among others. Overall, other than providing novel disease control strategies that meet environmental regulations, natural priming agents are valuable tools to help unravel the complex mechanisms underlying the induced resistance (IR) phenomenon. The data presented in this review reflect the novel contributions made from studyin…