31 research outputs found
Daily anticipatory rhythms of behavior and body temperature in response to glucose availability in rats
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
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
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
<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
Análise dos aspectos socioeconômicos e demográficos de famílias atendidas em um programa de triagem auditiva neonatal ao longo de três anos
OBJETIVO: analisar fatores socioeconômicos e demográficos, dos anos de 2007 a 2009, de mães de neonatos e lactentes participantes de um programa de saúde auditiva infantil. MÉTODOS: a coleta de dados foi realizada a partir do banco de dados do programa de Triagem auditiva neonatal, que contém informações retiradas do registro de cada neonato ou lactente. Participaram 2476 mães de neonatos e lactentes atendidos na etapa da Triagem Auditiva Neonatal, entre 2007 a 2009. RESULTADOS: entre as variáveis demográficas destaca-se que 65,1% das mães possuíam idades entre 20 e 34 anos e 67,5% eram casadas. Nas variáveis socioeconômicas, destaca-se que 36,2% das mães possuíam o ensino fundamental incompleto e 56,4% eram donas de casa e 96,7% tiveram seus filhos em maternidades públicas. CONCLUSÃO: apesar dos resultados indicarem um crescimento de melhores condições de vida, durante os três anos de estudo, ainda observa-se, em termos percentuais, que a população estudada encontra-se em condições desfavoráveis para uma boa saúde das mães, e, consequentemente para a saúde e desenvolvimento global dos neonatos e lactentes. Esses resultados chamam a atenção para o desenvolvimento de ações de promoção da saúde na população estudada, devendo, portanto, serem incluídas quando da implementação de um programa de Saúde Auditiva Infantil de uma dada região