RESUMO
Although the recent years have witnessed a growing interest in functional connectivity (FC) through brain sources, the FC in extreme situations has not been completely elucidated. This paper is aimed at investigating whether the expertise acquired during the deep-sea diving is reflected in FC in a group of professional divers (PDs) compared to a group of new divers (NDs), and how it could affect the concentration and stress levels. The sources of brain frequency rhythms, derived by the electroencephalography acquisition in a hyperbaric chamber, were extracted in different frequency bands and the corresponding FC was estimated in order to compare the two groups. The results highlighted a significant decrease of the alpha source in PDs during air breathing and a significant increase of the upper beta source over central areas at the beginning of post-oxygen air, as well as an increase of beta FC between fronto-temporal regions in the last minutes of oxygen breathing and in the early minutes of post-oxygen air. This provides evidence in support of the hypothesis that experience and expertise differences would modulate brain networks. These experiments provided the unique opportunity of investigating the impact of the neurophysiological activity in simulated critical scenarios in view of the investigation in real sea-water experiments.
Assuntos
Mergulho/fisiologia , Eletroencefalografia/métodos , Vias Neurais/fisiologia , Adulto , Ritmo alfa , Ritmo beta , Feminino , Humanos , Aprendizagem , Masculino , Oxigênio/metabolismo , Consumo de Oxigênio , Respiração , Estresse PsicológicoRESUMO
Uterine leiomyomas (fibroids or myomas) are the most common benign tumors of premenopausal women and new medical treatments are needed. This study aimed to determine the effects of omega-3 fatty acids on the lipid profile, membrane architecture and gene expression patterns of extracellular matrix components (collagen1A1, fibronectin, versican, or activin A), mechanical signaling (integrin ß1, FAK, and AKAP13), sterol regulatory molecules (ABCG1, ABCA1, CAV1, and SREBF2), and mitochondrial enzyme (CYP11A1) in myometrial and leiomyoma cells. Myometrial tissues had a higher amount of arachidonic acid than leiomyoma tissues while leiomyoma tissues had a higher level of linoleic acid than myometrial tissues. Treatment of primary myometrial and leiomyoma cells with eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) reduced the monounsaturated fatty acid (MUFA) content and increased the polyunsaturated fatty acid (PUFA) content in both cell types. Myometrial and leiomyoma cell membranes were in the liquid-crystalline phase, but EPA- and DHA-treated cells had decreased membrane fluidity. While we found no changes in the mRNA expression of ECM components, EPA and DHA treatment reduced levels of ABCG1, ABCA1, and AKAP13 in both cell types. EPA and DHA also reduced FAK and CYP11A1 expression in myometrial cells. The ability of omega-3 fatty acids to remodel membrane architecture and downregulate the expression of genes involved in mechanical signaling and lipid accumulation in leiomyoma cells offers to further investigate this compound as preventive and/or therapeutic option.
Assuntos
Membrana Celular/metabolismo , Ácidos Graxos Ômega-3/farmacologia , Regulação Neoplásica da Expressão Gênica , Leiomioma/genética , Leiomioma/patologia , Lipídeos/química , Neoplasias Uterinas/genética , Neoplasias Uterinas/patologia , Ativinas/genética , Ativinas/metabolismo , Adulto , Membrana Celular/efeitos dos fármacos , Enzima de Clivagem da Cadeia Lateral do Colesterol/genética , Enzima de Clivagem da Cadeia Lateral do Colesterol/metabolismo , Ácidos Docosa-Hexaenoicos/farmacologia , Ácido Eicosapentaenoico/farmacologia , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Pessoa de Meia-Idade , Miométrio/efeitos dos fármacos , Miométrio/metabolismo , Miométrio/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais/efeitos dos fármacos , Esteróis/metabolismoRESUMO
Epidemiological studies have linked high consumption of meat with major age-related diseases including cardiovascular diseases. Abnormal postprandial increases in plasma lipids after a meat meal have been hypothesized among the pathogenetic mechanisms. However, it is still unknown if the postprandial serum derived after a normal meat meal is able to affect endothelial function, and if the type of meat and the age of the donors are critical factors. Here, we show the effects of postprandial sera derived from healthy adults and elderly volunteers who consumed meat meals on human coronary artery endothelial cell (HCAEC) oxidative stress, gene expression, DNA damage, and cellular senescence. We observed that a single exposure to postprandial serum induces a slight increase in ROS that is associated with modulation of gene expression pathways related to oxidative stress response and metabolism. The postprandial-induced increase in ROS is not associated with a measurable DNA oxidative damage. However, repeated exposure to postprandial serum induces an acceleration of cellular senescence. Taking into account the deleterious role of cellular senescence in age-related vascular diseases, the results suggest a new mechanism by which excessive meat consumption and time spent in postprandial state may affect health status during aging.
Assuntos
Senescência Celular , Vasos Coronários/fisiologia , Células Endoteliais/fisiologia , Carne , Estresse Oxidativo , Período Pós-Prandial/fisiologia , Adulto , Idoso , Envelhecimento/metabolismo , Células Cultivadas , Culinária , Regulação da Expressão Gênica , Humanos , Pessoa de Meia-Idade , Espécies Reativas de Oxigênio/metabolismo , Triglicerídeos/sangue , VoluntáriosRESUMO
In the present study, we assessed for the first time the changes in the antioxidant capacity, total phenolic content, and polyphenolic composition of interspecific hybrid palm oil extracted from Elaeis oleifera × Elaeis guineensis (O × G, Coari × La Mé cultivar) during the fruit ripening process 18, 20, 22, and 24 weeks after anthesis. A progressive decrease (p < 0.05) of phenolic content occurred during fruit development together with marked changes in polyphenol profiles. Significant negative correlations were established between antioxidant activity measured by TEAC (R = -0.954; p < 0.05) and ORAC (R = -0.745; p < 0.05) and the fruit ripening stage, while a positive correlation between total phenolic content was found using either the TEAC assay or the ORAC assay. The highest DPPH radical scavenging activity was also obtained with oils extracted at 18 WAA. These results highlight that O × G fruits of early ripeness represent a better source of phenolic compounds and may provide extracts with higher antioxidant activities when hybrid palm oil is aimed to be used as a functional ingredient for the development of food or food products with antioxidant properties.
Assuntos
Antioxidantes/química , Arecaceae/química , Frutas/crescimento & desenvolvimento , Fenóis/química , Extratos Vegetais/química , Óleos de Plantas/química , Polifenóis/química , Antioxidantes/metabolismo , Arecaceae/genética , Arecaceae/crescimento & desenvolvimento , Arecaceae/metabolismo , Frutas/química , Frutas/genética , Frutas/metabolismo , Endogamia , Óleo de Palmeira , Fenóis/metabolismo , Extratos Vegetais/metabolismo , Óleos de Plantas/metabolismo , Polifenóis/metabolismoRESUMO
Recording biological signals inside a hyperbaric chamber poses technical challenges (the steel walls enclosing it greatly attenuate or completely block the signals as in a Faraday cage), practical (lengthy cables creating eddy currents), and safety (sparks hazard from power supply to the electronic apparatus inside the chamber) which can be overcome with new wireless technologies. In this technical report we present the design and implementation of a Bluetooth system for electroencephalographic (EEG) recording inside a hyperbaric chamber and describe the feasibility of EEG signal transmission outside the chamber. Differently from older systems, this technology allows the online recording of amplified signals, without interference from eddy currents. In an application of this technology, we measured EEG activity in professional divers under three experimental conditions in a hyperbaric chamber to determine how oxygen, assumed at a constant hyperbaric pressure of 2.8 ATA , affects the bioelectrical activity. The EEG spectral power estimated by fast Fourier transform and the cortical sources of the EEG rhythms estimated by low-resolution brain electromagnetic analysis were analyzed in three different EEG acquisitions: breathing air at sea level; breathing oxygen at a simulated depth of 18 msw, and breathing air at sea level after decompression.
Assuntos
Câmaras de Exposição Atmosférica , Eletroencefalografia/instrumentação , Oxigenoterapia Hiperbárica/instrumentação , Tecnologia sem Fio , Adulto , Descompressão , Eletroencefalografia/efeitos dos fármacos , Fenômenos Eletrofisiológicos , Desenho de Equipamento , Estudos de Viabilidade , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Sistemas On-Line , Oxigênio/farmacologia , Oxigênio/toxicidade , RespiraçãoRESUMO
OBJECTIVE: The aim was to investigate and define possible alterations in cerebral activity during prolonged hyperbaric oxygen exposure and decompression as compared to baseline activity. METHODS: Thirty-two channel electroencephalography (EEG) was recorded with a Bluetooth EEG system in 11 subjects. A 20-min EEG recording was carried out under three different conditions: breathing air inside a hyperbaric chamber at sea level; breathing oxygen at a simulated depth of 18 msw; breathing air at sea level after decompression. Relative EEG power was estimated in frequency ranges. RESULTS: During oxygen breathing, brain activity showed an early fast delta decrease in the posterior regions, with a synchronous and significant increase in alpha in the same regions. After decompression, the delta relative power decrease was uniformly distributed over the cerebral cortex until minute 8, and the alpha relative power was maximal in the posterior regions during the first 2 min. CONCLUSIONS: These results may be relevant for establishing a reference point in future studies on oxygen-sensitive subjects who reported problems during oxygen diving. SIGNIFICANCE: Significant changes in EEG relative power suggest that it may be possible to define and recognize landmarks of oxygen-induced brain activity, which would be useful in the medical treatment of subjects reporting "oxygen-toxicity diving-related problems".
Assuntos
Córtex Cerebral/fisiologia , Mergulho/fisiologia , Eletroencefalografia/tendências , Oxigenoterapia Hiperbárica/tendências , Adulto , Eletroencefalografia/métodos , Humanos , Oxigenoterapia Hiperbárica/métodos , Masculino , Pessoa de Meia-Idade , Mecânica Respiratória/fisiologiaRESUMO
INTRODUCTION: The narcotic effect of nitrogen impairs diver performance and limits dive profiles, especially for deep dives using compressed air. It would be helpful to establish measurable correlates of nitrogen narcosis. METHODS: The authors observed the electroencephalogram (EEG) of 10 subjects, ages 22-27 yr, who breathed air during a 3-min compression to a simulated depth of 80 msw (9 ATA). The EEG from a 19-electrode cap was recorded for 20 min while the subject reclined on a cot with eyes closed, first at 1 ATA before the dive and again at 9 ATA. Signals were analyzed using Fast Fourier Transform and brain mapping for frequency domains 0-4 Hz, 4-7 Hz, 7-12 Hz, and 12-15 Hz. Student's paired t-test and correlation tests were used to compare results for the two conditions. RESULTS: Two EEG patterns were observed. The first was an increase in delta and theta activity in all cortical regions that appeared in the first 2 min at depth and was related to exposure time. The second was an increase in delta and theta activity and shifting of alpha activity to the frontal regions at minute 6 of breathing air at 9 ATA and was related to the narcotic effects of nitrogen. DISCUSSION: If confirmed by studies with larger case series, this EEG pattern could be used to identify nitrogen narcosis for various gas mixtures and prevent the dangerous impact of nitrogen on diver performance.
Assuntos
Mapeamento Encefálico , Encéfalo/fisiopatologia , Eletroencefalografia , Narcose por Gás Inerte/fisiopatologia , Nitrogênio/efeitos adversos , Adulto , Mergulho , Análise de Fourier , Humanos , MasculinoRESUMO
We tested the hypothesis that acute hypoxia may alter the circadian pattern of body temperature in adult humans. Six healthy subjects were studied in normoxia, hypoxia (approximately 13% inspired O(2)), and again normoxia, each session lasting >24 h and spaced a few days apart, with a constant routine protocol of sustained wakefulness and minimal activity. Some parameters (e.g., tympanic and abdominal temperatures, heart rate) were recorded continuously; others (e.g., oxygen consumption and pulmonary ventilation) were monitored for approximately 10 min every 2 h. The amplitudes of the circadian oscillation of tympanic, abdominal, and calf skin temperatures were reduced in hypoxia, averaging, respectively, 61%, 80% and 50% of the normoxic amplitude. Oxygen consumption and pulmonary ventilation, which presented a circadian pattern in normoxia, had no longer significant oscillations during hypoxia, whereas the opposite was the case for heart rate and diastolic pressure. Therefore, acute hypoxia can disturb the normal circadian patterns and, specifically, depress those of body temperature. These effects, qualitatively similar to those observed in chronically hypoxic animals and humans, could contribute to sleep disturbances at high altitude.