31 research outputs found

    Daily anticipatory rhythms of behavior and body temperature in response to glucose availability in rats

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    When food is available recurrently at a particular time of day, several species increase their locomotion in the hours that precede food delivery, a phenomenon called food anticipatory activity (FAA). In mammals, many studies have shown that FAA is driven by a food-entrained circadian oscillator (FEO) that is distinct from the light-entrained pacemaker in the suprachiasmatic nucleus of the hypothalamus. Few studies have investigated the effect of sugar ingestion on food anticipatory rhythms and the FEO. We aimed to extend the understanding of the role of glucose on the emergence of food anticipatory rhythms by investigating whether glucose ingestion is sufficient to produce daily food anticipation, reflected by motor activity and core body temperature rhythms. Under a 12 h/12 h light/dark cycle, chow-deprived rats had glucose solution available between Zeitgeber Time (ZT) 6 and ZT 9 for 10 days (glucose restriction group), whereas control animals had chow available within the same time window (chow restriction group). Animals in both groups exhibited anticipatory motor activity and body temperature around the fourth day of the scheduled food restriction. Glucose-fed rats ingested ~15 kcal on the days immediately before FAA emergence and reached an intake of ~20 kcal/day, whereas chow-fed rats ingested ~40 kcal/day. The glucose restriction group exhibited a pattern of food anticipation (activity and temperature) that was extremely similar to that observed in the chow restriction group. We conclude that glucose ingestion is a sufficient temporal cue to produce recurrent food anticipation, reflected by activity and temperature rhythms, in rats

    Induction of apoptosis in leukemia cell lines by new copper(II) complexes containing naphthyl groups via interaction with death receptors

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    The synthesis, physico-chemical characterization and cytotoxicity of four new ligands and their respective copper(II) complexes toward two human leukemia cell lines (THP-1 and U937) are reported (i.e. [(HL1) Cu(mu-Cl)(2)Cu(HL1)]Cl-2 center dot H2O (1), [(H2L2)Cu(mu-Cl)(2)Cu(H2L2)]Cl-2 center dot 5H(2)O (2), [(HL3)Cu(mu-Cl)(2)Cu(HL3)]Cl-2 center dot 4H(2) (3), [(H2L4)Cu(mu-Cl)(2)Cu(H2L4)]Cl-2 center dot 6H(2)O (4)). Ligands HL1 and HL3 contain two pyridines, amine and alcohol moieties with a naphthyl pendant unit yielding a N3O coordination metal environment Ligands H2L2 and H2L4 have pyridine, phenol, amine and alcohol groups with a naphthyl pendant unit providing a N2O2 coordination metal environment These compounds are likely to be dinuclear in the solid state but form mononuclear species in solution. The complexes have an antiproliferative effect against both leukemia cell lines; complex (2) exhibits higher activity than cisplatin against U937 (8.20 vs 16.25 mu mol dm(-3)) and a comparable one against THP-1. These human neoplastic cells are also more susceptible than peripheral blood mononuclear cells (PBMCs) toward the tested compounds. Using C57BL/6 mice an LD50 of 55 mg kg(-1) was determined for complex (2), suggesting that this compound is almost four times less toxic than cisplatin (LD50 = 14.5 mg kg(-1)). The mechanism of cell death promoted by ligand H2L2 and by complexes (2) and (4) was investigated by a range of techniques demonstrating that the apoptosis signal triggered at least by complex (2) starts from an extrinsic pathway involving the activation of caspases 4 and 8. This signal is amplified by mitochondria with the concomitant release of cytochrome c and the activation of caspase 9. (C) 2015 Elsevier Inc. All rights reserved

    Exposure to Inorganic Mercury Causes Oxidative Stress, Cell Death, and Functional Deficits in the Motor Cortex

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    Mercury is a toxic metal that can be found in the environment in three different forms – elemental, organic and inorganic. Inorganic mercury has a lower liposolubility, which results in a lower organism absorption and reduced passage through the blood–brain barrier. For this reason, exposure models that use inorganic mercury in rats in order to evaluate its effects on the central nervous system are rare, especially in adult subjects. This study investigated if a chronic exposure to low doses of mercury chloride (HgCl2), an inorganic form of mercury, is capable of promoting motor alterations and neurodegenerative in the motor cortex of adult rats. Forty animals were exposed to a dose of 0.375 mg/kg/day, for 45 days. They were then submitted to motor evaluation and euthanized to collect the motor cortex. Measurement of mercury deposited in the brain parenchyma, evaluation of oxidative balance, quantification of cellular cytotoxicity and apoptosis and density of mature neurons and astrocytes of the motor cortex were performed. It was observed that chronic exposure to inorganic mercury caused a decrease in balance and fine motor coordination, formation of mercury deposits and oxidative stress verified by the increase of lipoperoxidation and nitrite concentration and a decrease of the total antioxidant capacity. In addition, we found that this model of exposure to inorganic mercury caused cell death by cytotoxicity and induction of apoptosis with a decreased number of neurons and astrocytes in the motor cortex. Our results provide evidence that exposure to inorganic mercury in low doses, even in spite of its poor ability to cross biological barriers, is still capable of inducing motor deficits, cell death by cytotoxicity and apoptosis, and oxidative stress in the motor cortex of adult rats

    Table_1_The Effects of Moderate Physical Exercise on Adult Cognition: A Systematic Review.docx

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    <p>Background: Physical exercise is a systematic sequence of movements executed with a predefined purpose. This muscular activity impacts not only on circulatory adaptations, but also neuronal integration with the potential to influence cognition. The aim of this review was to determine whether the literature supports the idea that physical exercise promotes cognitive benefits in healthy adults.</p><p>Methods: A systematic search for relevant articles was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis criteria using available databases (PubMed, LILACS, Scopus, Web of Science, The Cochrane Library, OpenGrey, Google Scholar and CENTRAL). The search terms included “humans” or “adults” or “cognition” or “awareness” or “cognitive dissonance” or “cognitive reserve” or “comprehension” or “consciousness” and “motor activity” or “exercise” or “physical fitness,” and not “aged” or “nervous system diseases,” with the purpose of finding associations between moderate physical exercise and cognition. A methodological quality and risk of bias unit assessed the eligibility of articles.</p><p>Results: A total of 7179 articles were identified. Following review and quality assessment, three articles were identified to fulfill the inclusion criteria. An association between moderate physical exercise and cognition was observed. Improvements in cognitive parameters such as reduced simple reaction time, improved response precision and working memory were identified among the included articles.</p><p>Conclusion: This systematic review found that moderate physical exercise improves cognition.</p

    Estado nutricional e consumo alimentar de mulheres jovens na fase lútea e folicular do ciclo menstrual Nutritional status and food consumption of young women in the luteal and follicular phases of the menstrual cycle

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    OBJETIVO: Avaliar o estado nutricional e a ingestão alimentar de mulheres adultas sadias durante o ciclo menstrual. MÉTODOS: Quarenta e cinco voluntárias foram acompanhadas durante três meses. A avaliação do estado nutricional foi baseada no índice de massa corporal, porcentagem de gordura e água corporal. Foram aplicados seis registros alimentares para análise da ingestão dos grupos de alimentos, usando como base o guia alimentar da pirâmide. Para a observação do sintoma "desejos alimentares", foram utilizados três "mapas de sintomas diários". RESULTADOS: Os valores médios de índice de massa corporal e de porcentagem de gordura corporal apresentaram-se normais em ambas as fases, entretanto foi observado maior percentual de mulheres com água corporal acima do padrão na fase lútea (77%). O consumo de alimentos do grupo complementar foi maior na fase lútea. Todos os outros grupos de alimentos, com exceção do grupo de carnes, apresentaram consumo inferior às recomendações, em ambas as fases. A intensidade do sintoma "desejos alimentares" foi leve durante o ciclo menstrual, não sendo observada diferença significativa entre as fases. O sintoma "desejos alimentares" associou-se positivamente com o aumento da ingestão do grupo complementar na fase lútea. CONCLUSÃO: O ciclo menstrual influencia o comportamento alimentar e leva à retenção hídrica, na fase lútea, em mulheres adultas sadias.<br>OBJECTIVE: This study assessed the nutritional status and food intake of healthy young women during the menstrual cycle. METHODS: Forty-five volunteers were followed for three months. Their nutritional status was determined by body mass index, body fat and total body water. Six food recall instruments were used to evaluate food group intake according to the food guide pyramid. Food cravings were detected by three daily symptom charts. RESULTS: The mean body mass index and body fat were normal in both phases; however, there was a higher percentage of women with above-average body water during the luteal phase (77%). The consumption of foods from the complementary group was higher during the luteal phase. The consumption of foods from all other groups during both phases was below the recommended levels, except for meats. Food cravings were mild during the entire menstrual cycle and there were no significant differences between the phases. Food cravings were positively associated with increased intake of foods from the complementary group. CONCLUSION: In healthy women, the menstrual cycle influences food consumption and the luteal phase causes water retention
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