Suchergebnisse

Introdução: O P300 é um procedimento objetivo para avaliação da função auditiva. O eliciar de seus componentes envolve áreas corticais relacionadas à percepção, atenção, memória auditiva e mecanismos de cognição. Objetivo: avaliar as latências dos componentes N1, N2, P1, P2 e P3 em adolescentes segundo variáveis sócio-econômico-demográficas, educacionais, e estado nutricional. Método: Estudo do tipo série de casos envolvendo 32 adolescentes de 13 a 18 anos, de ambos os sexos, das escolas públicas do Recife - PE. Foram analisados os componentes do P300 com 200 estímulos mediante uso do equipamento Smart Ep Intelligent Hearing Systems (I.H.S). Resultados: Observou-se que os adolescentes com repetência escolar apresentaram prolongamento da latência do componente P1 maior (p= 0,04), quando comparados aos adolescentes sem registro de repetência escolar, assim como adolescentes da maior classe social apresentaram melhor latência (p= 0,03) no componente P3, quando comparados com aqueles de menor classe social. Conclusão: Prolongamento na latência dos componentes P1 e P3 foram encontrados em adolescentes com repetência escolar e com nível socioeconômico mais baixo.

The P300 component of the event-related brain potential was assessed as a measure of mental workload using 12 subjects who flew simulated visual flight rules final approaches and landings under workloads varied by manipulating turbulence and hypoxia. P300 was elicited with auditory and visual "oddball" subsidiary tasks requiring the detection of infrequent tones or flashes of an artificial horizon. The results showed that root mean square error flying performance was systematically degraded by both workload manipulations. P300 amplitude exhibited a complex pattern that was not strongly related to performance. By contrast, P300 latency covaried closely with performance, increasing as a function of workload in both modalities. These results suggest that P300 latency indexes the slowing of perceptual/cognitive processing caused by workload and that this measure is sensitive to an important aspect of flying.

A classification concealed information test (CIT) used the "brain fingerprinting" method of applying P300 event-related potential (ERP) in detecting information that is (1) acquired in real life and (2) unique to US Navy experts in military medicine. Military medicine experts and non-experts were asked to push buttons in response to three types of text stimuli. Targets contain known information relevant to military medicine, are identified to subjects as relevant, and require pushing one button. Subjects are told to push another button to all other stimuli. Probes contain concealed information relevant to military medicine, and are not identified to subjects. Irrelevants contain equally plausible, but incorrect/irrelevant information. Error rate was 0%. Median and mean statistical confidences for individual determinations were 99.9% with no indeterminates (results lacking sufficiently high statistical confidence to be classified). We compared error rate and statistical confidence for determinations of both information present and information absent produced by classification CIT (Is a probe ERP more similar to a target or to an irrelevant ERP?) vs. comparison CIT (Does a probe produce a larger ERP than an irrelevant?) using P300 plus the late negative component (LNP; together, P300-MERMER). Comparison CIT produced a significantly higher error rate (20%) and lower statistical confidences: mean 67%; information-absent mean was 28.9%, less than chance (50%). We compared analysis using P300 alone with the P300 + LNP. P300 alone produced the same 0% error rate but significantly lower statistical confidences. These findings add to the evidence that the brain fingerprinting methods as described here provide sufficient conditions to produce less than 1% error rate and greater than 95% median statistical confidence in a CIT on information obtained in the course of real life that is characteristic of individuals with specific training, expertise, or organizational affiliation.

Left ventricular remodeling following myocardial infarction (MI) is related to adverse outcome. It has been shown that an up-regulation of plasma soluble ST2 (sST2) levels are associated with lower pre-discharge left ventricular (LV) ejection fraction, adverse cardiovascular outcomes and mortality outcome after MI. The mechanisms involved in its modulation are unknown and there is not specific treatment capable of lowering plasma sST2 levels in acute-stage HF. We recently identified Yin-yang 1 (Yy1) as a transcription factor related to circulating soluble ST2 isoform (sST2) expression in infarcted myocardium. However, the underlying mechanisms involved in this process have not been thoroughly elucidated. This study aimed to evaluate the pathophysiological implication of miR-199a-5p in cardiac remodeling and the expression of the soluble ST2 isoform. Myocardial infarction (MI) was induced by permanent ligation of the left anterior coronary artery in C57BL6/J mice that randomly received antimiR199a therapy, antimiR-Ctrl or saline. A model of biomechanical stretching was also used to characterize the underlying mechanisms involved in the activation of Yy1/sST2 axis. Our results show that the significant upregulation of miR-199a-5p after myocardial infarction increases pathological cardiac hypertrophy by upregulating circulating soluble sST2 levels. AntimiR199a therapy up-regulates Sirt1 and inactivates the co-activator P300 protein, thus leading to Yy1 inhibition which decreases both expression and release of circulating sST2 by cardiomyocytes after myocardial infarction. Pharmacological inhibition of miR-199a rescues cardiac hypertrophy and heart failure in mice, offering a potential therapeutic approach for cardiac failure. ; This study was supported by a grant from the Seneca Foundation-Agency of Science and Technology of the Region of Murcia (20652/JLI/18) and a grant from the Instituto de Salud Carlos III (PI19/00519) which is cofinanced through the European Union's European Regional Development Fund (FEDER). Dr. Lax is a Ramon and Cajal researcher at the Department of Medicine, University of Murcia. ; Sí

Introduction: The phenomenon of craving and attention bias towards drug cues is theorized to operate cooperatively, owing to the principles of associative learning. In this context, the conditioned response to drug-related stimuli activates reward mechanisms within the brain, consequently inducing craving and fostering the underlying mechanisms that contribute to relapse in individuals with substance use disorders. Multiple studies have assessed the relationship between attention to substance-related cues and subjective craving through electroencephalography (EEG), but their findings have yet to be synthesized and examined. This review summarizes the association between the amplitude of the P300 event-related potential (ERP) and substance use craving, compares discrepancies in results by type of substance, and discusses gaps in the literature to inform future research. Methods: A systematic search was conducted on Embase, Web of Science, CINAHL, and PsychINFO databases. Studies were published in English and included peer-reviewed human research investigating the relationship between EEG P300 ERP and self-reported substance use craving. The included study samples comprised of in treatment or non-treatment-seeking participants who use substances. The primary outcomes of interest were those derived from inferential statistics assessing P300 amplitude and substance use craving. Results: Ten studies were included in the final search and were organized by substance type: three alcohol, three cocaine, two tobacco, one heroin, and one cannabis. Results were mixed for alcohol and cocaine. Studies on tobacco, heroin, and cannabis use were congruent for associations between the P300 amplitude and craving. Conclusions: Overall findings are mixed between studies addressing the association of the EEG P300 amplitude and craving. These results should be considered in the context of the limited sample size, underpowered analyses, and methodological differences that potentially contribute to discrepancies in outcomes. Further research is required to assess the role of craving assessment, EEG methodology, and substance-related factors on the association between P300 amplitude and self-reported craving.