RESUMO
Younger (M = 21 years) and older (M = 74 years) adults completed a spatial negative priming (SNP) task where (central) events (i.e., target or distractor) are presented in trial pairs: first the prime and then the probe. Free-choice trials were included (1 location: 2 permissible responses), which allowed us to isolate response inhibition and its consequent inhibitory aftereffects (i.e., current inhibition interferes with later related processing-e.g., SNP). The inhibitory aftereffects associated with the suppression of responses activated by distractor-occupied locations were highly comparable for younger and older adults; including similar SNP effect sizes, a significant tendency to select against former distractor (inhibited) responses (within-hand finger options) on free-choice trials, and latency delays attributable solely to the use of self-selected distractor responses. Aftereffects generated by target-occupied prime trials locations were also the same for both age groups; recently executed target responses were selected for and produced faster responding (within hand). Aftereffects were absent on between-hand free-choice trials and, overall, response selection determinants on free-choice trials matched for older and younger adults.
Assuntos
Comportamento de Escolha/fisiologia , Inibição Psicológica , Percepção Visual/fisiologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa , Tempo de Reação/fisiologia , Adulto JovemRESUMO
Mesenchymal stem cells (MSCs) transplantation seems to be a promising new therapy for diabetic wound healing (DWH), and currently, arrays of MSCs from various sources ranging from umbilical, adipose to dental sources are available as a treatment modality for this disease. However, it now appears that only a fraction of transplanted cells actually assimilate and survive in host tissues suggesting that the major mechanism by which stem cells participate in tissue repair are most likely related to their secretome level. These include a wide range of growth factors, cytokines, and chemokines, which can be found from the conditioned medium (CM) used to culture the cells. Basic studies and preclinical work confirm that the therapeutic effect of CMs are comparable with the application of stem cells. This review describes in detail the wound healing process in diabetes and the cellular and biological factors that influence the process. Subsequently, through a comprehensive literature search of studies related to wound healing in diabetics, we aim to provide an overview of scientific merits of using MSCs-CM in the treatment of diabetic wound as well as the significant caveats, which restricts its potential use in clinical set-ups. To our best knowledge, this is one of the first review papers that collect the importance of stem cells as an alternative treatment to the DWH. We anticipate that the success of this treatment will have a significant clinical impact on diabetic wounds.
Assuntos
Complicações do Diabetes/tratamento farmacológico , Peptídeos e Proteínas de Sinalização Intercelular , Células-Tronco Mesenquimais/metabolismo , Cicatrização/efeitos dos fármacos , Ferimentos e Lesões/tratamento farmacológico , Animais , Meios de Cultivo Condicionados/metabolismo , Meios de Cultivo Condicionados/farmacologia , Complicações do Diabetes/metabolismo , Complicações do Diabetes/patologia , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/uso terapêutico , Ferimentos e Lesões/metabolismo , Ferimentos e Lesões/patologiaRESUMO
Responding to a target's current (probe trial) location is slower when it appears at a former distractor-occupied position (i.e., ignored-repetition [IR] trial), relative to when it arises at a new location (i.e., control trial). This RT(IR) > RT(Control) inequality defines the spatial negative priming (SNP) effect in latency terms. It is uncertain whether the elevated RT(IR) is due to the inhibition of the distractor-occupied location or to the inhibition of this location's assigned manual response (SNP locus issue). The main aim here was to examine the SNP locus issue. Notably, our SNP design used centrally presented visual events and included having two locations share a common response (many:1 location-to-response mapping) and the use of informative (70 % validity) or uninformative probe-trial response cues. The many:1 mapping trials allowed for the detection of location and response inhibition presence. Results showed that the latter, but not the former, causes inhibitory aftereffects (e.g., SNP) following uninformative response cues. Consistent with this finding, when the informative response cue was valid and was assigned to the many:1 probe response that had just served as the prime distractor response, inhibitory aftereffects were eliminated, when the probe target appeared at the prime distractor position (IR trial) or at a new location (distractor-response repeat trial). Blocked retrieval of stored distractor-processing representations was proposed as the mechanism for inhibitory aftereffect prevention.