34 research outputs found

    A2 Noradrenergic Lesions Prevent Renal Sympathoinhibition Induced by Hypernatremia in Rats

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    Renal vasodilation and sympathoinhibition are recognized responses induced by hypernatremia, but the central neural pathways underlying such responses are not yet entirely understood. Several findings suggest that A2 noradrenergic neurons, which are found in the nucleus of the solitary tract (NTS), play a role in the pathways that contribute to body fluid homeostasis and cardiovascular regulation. The purpose of this study was to determine the effects of selective lesions of A2 neurons on the renal vasodilation and sympathoinhibition induced by hypertonic saline (HS) infusion. Male Wistar rats (280–350 g) received an injection into the NTS of anti-dopamine-beta-hydroxylase-saporin (A2 lesion; 6.3 ng in 60 nl; n = 6) or free saporin (sham; 1.3 ng in 60 nl; n = 7). Two weeks later, the rats were anesthetized (urethane 1.2 g⋅kg−1 b.wt., i.v.) and the blood pressure, renal blood flow (RBF), renal vascular conductance (RVC) and renal sympathetic nerve activity (RSNA) were recorded. In sham rats, the HS infusion (3 M NaCl, 1.8 ml⋅kg−1 b.wt., i.v.) induced transient hypertension (peak at 10 min after HS; 9±2.7 mmHg) and increases in the RBF and RVC (141±7.9% and 140±7.9% of baseline at 60 min after HS, respectively). HS infusion also decreased the RSNA (−45±5.0% at 10 min after HS) throughout the experimental period. In the A2-lesioned rats, the HS infusion induced transient hypertension (6±1.4 mmHg at 10 min after HS), as well as increased RBF and RVC (133±5.2% and 134±6.9% of baseline at 60 min after HS, respectively). However, in these rats, the HS failed to reduce the RSNA (115±3.1% at 10 min after HS). The extent of the catecholaminergic lesions was confirmed by immunocytochemistry. These results suggest that A2 noradrenergic neurons are components of the neural pathways regulating the composition of the extracellular fluid compartment and are selectively involved in hypernatremia-induced sympathoinhibition

    The COGs (context, object, and goals) in multisensory processing

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    Our understanding of how perception operates in real-world environments has been substantially advanced by studying both multisensory processes and “top-down” control processes influencing sensory processing via activity from higher-order brain areas, such as attention, memory, and expectations. As the two topics have been traditionally studied separately, the mechanisms orchestrating real-world multisensory processing remain unclear. Past work has revealed that the observer’s goals gate the influence of many multisensory processes on brain and behavioural responses, whereas some other multisensory processes might occur independently of these goals. Consequently, other forms of top-down control beyond goal dependence are necessary to explain the full range of multisensory effects currently reported at the brain and the cognitive level. These forms of control include sensitivity to stimulus context as well as the detection of matches (or lack thereof) between a multisensory stimulus and categorical attributes of naturalistic objects (e.g. tools, animals). In this review we discuss and integrate the existing findings that demonstrate the importance of such goal-, object- and context-based top-down control over multisensory processing. We then put forward a few principles emerging from this literature review with respect to the mechanisms underlying multisensory processing and discuss their possible broader implications

    Nutrition and cancer: A review of the evidence for an anti-cancer diet

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    It has been estimated that 30–40 percent of all cancers can be prevented by lifestyle and dietary measures alone. Obesity, nutrient sparse foods such as concentrated sugars and refined flour products that contribute to impaired glucose metabolism (which leads to diabetes), low fiber intake, consumption of red meat, and imbalance of omega 3 and omega 6 fats all contribute to excess cancer risk. Intake of flax seed, especially its lignan fraction, and abundant portions of fruits and vegetables will lower cancer risk. Allium and cruciferous vegetables are especially beneficial, with broccoli sprouts being the densest source of sulforophane. Protective elements in a cancer prevention diet include selenium, folic acid, vitamin B-12, vitamin D, chlorophyll, and antioxidants such as the carotenoids (α-carotene, β-carotene, lycopene, lutein, cryptoxanthin). Ascorbic acid has limited benefits orally, but could be very beneficial intravenously. Supplementary use of oral digestive enzymes and probiotics also has merit as anticancer dietary measures. When a diet is compiled according to the guidelines here it is likely that there would be at least a 60–70 percent decrease in breast, colorectal, and prostate cancers, and even a 40–50 percent decrease in lung cancer, along with similar reductions in cancers at other sites. Such a diet would be conducive to preventing cancer and would favor recovery from cancer as well

    Avaliação da aptidão cardiorrespiratória de crianças com displasia broncopulmonar Cardiorespiratory capacity assessment on children with bronchopulmonary dysplasia

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    OBJETIVO: Avaliar a aptidão cardiorrespiratória e verificar a presença de broncoespasmo induzido pelo exercício (BIE) em crianças com displasia broncopulmonar (DBP). MÉTODO: Foram realizadas prova de função pulmonar e análise de gases em um teste cardiopulmonar, em 46 crianças com idade entre 7 a 10 anos, formando três grupos: crianças nascidas pré-termo com DBP, (DBP, n= 13); crianças nascidas pré-termo sem DBP, (RNPT, n= 13); e crianças saudáveis nascidas a termo, (Controle, n= 20). RESULTADOS: A duração dos testes foi 7,70 ± 1,49; 9,1 ± 2,02 e 8,4 ± 2,12 min; o VO2máximo foi 35,98 ± 5,33; 38,99 ± 6,73 e 34,91 ± 6,09 ml/kg/min; e a VE foi 28,54 ± 7,39; 28,84 ± 5,98 e 28,96 ± 6,96 l/min para os grupos DBP, RNPT e Controle, respectivamente. Não foram encontradas diferenças significantes entre os grupos (p> 0,05). A FCmáxima foi 188 ± 9,37; 196 ± 5,15 e 197 ± 10,90 bpm; a taxa de troca gasosa máxima (R) foi 1,21 ± 0,22; 1,10 ± 0,06 e 1,05 ± 0,05 para os grupos DBP, RNPT e Controle, respectivamente, sendo esses valores diferentes entre o grupo Controle e DBP (p< 0,05). Os valores do VEF1 pré e VEF1 pós-exercício foram de 99 ± 12% e 94 ± 14%; 100 ± 14% e 100 ± 15%; e 102 ± 15% e 101 ± 15%, para os grupos DBP, RNPT e Controle, respectivamente. Na comparação do VEF1 pré e pós-exercício não houve diferenças significantes e nem caracterização de BIE nos grupos. CONCLUSÃO: A diferença encontrada no R pode ser relacionada a alterações ventilatórias e à difusão pulmonar. A aptidão cardiorrespiratória das crianças com DBP é semelhante à dos grupos RNPT e Controle.<br>OBJECTIVE: To assess cardiorespiratory capacity and investigate the presence of exercise-induced bronchospasm among children with bronchopulmonary dysplasia. METHOD: Pulmonary function tests and gas analyses were performed in a cardiopulmonary test on 46 children aged 7-10 years. Three groups were formed: children born prematurely with bronchopulmonary dysplasia (BPD; n= 13), children born prematurely without bronchopulmonary dysplasia (Preterm; n= 13) and healthy children born at full term (Control; n= 20). RESULTS: The test duration was 7.70 ± 1.49; 9.1 ± 2.02 and 8.4 ± 2.12 min; VO2max was 35.98 ± 5.33; 38.99 ± 6.73 and 34.91 ± 6.09 ml/kg/min; and VE was 28.54 ± 7.39; 28.84 ± 5.98 and 28.96 ± 6.96 l/min for the BPD, Preterm and Control groups respectively. There were no significant differences between the groups (p> 0.05). The maximum heart rate was 188 ± 9.37; 196 ± 5.15 and 197 ± 10.90 beats/min and the respiratory exchange ratio (RER) was 1.21 ± 0.22; 1.10 ± 0.06 and 1.05 ± 0.05, for the BPD, Preterm and Control groups respectively, and there was a significant difference between the BPD and Control groups (p< 0.05). The FEV1 values before and after exercise were 99 ± 12% and 94 ± 14%; 100 ± 14% and 100 ± 15%; and 102 ± 15% and 101 ± 15%, for the BPD, Preterm and Control groups respectively. Comparison of FEV1 before and after exercise did not show any significant differences and exercise-induced bronchospasm was not characterized, in any of the groups. CONCLUSION: The difference in RER may be related to abnormal ventilation and pulmonary diffusion. The cardiorespiratory capacity of children with BPD was similar to that of the Preterm and Control groups
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