Pulvinus functional traits in relation to leaf movements: A light and transmission electron microscopy study of the vascular system

Previous studies on legume pulvini suggest that the vascular system plays an important role in the redistribution of ions and transmission of stimuli during leaf's movements. However, the number of anatomical and ultrastructural studies is limited to few species. The aim of this paper is to investigate the structure and cellular features of the pulvinus vascular system of nine legume species from Brazilian cerrado, looking for structural traits pointing to its participation in the leaf's movements. Samples were excised from the medial region of opened pulvinus of Bauhinia rufa, Copaifera langsdorffii, Senna rugosa (Caesalpinioideae), Andira humilis, Dalbergia miscolobium, Zornia dilphylla (Faboideae), Mimosa rixosa, Mimosa flexuosa and Stryphnodendron polyphyllum (Mimosoideae), and were prepared following light microscopy, transmission electron microscopy and histochemical standard techniques. The vascular system occupies a central position, comprises phloem and xylem and is delimited by a living sheath of septate fibers in all the species studied. This living cells sheath connects the cortex to the vascular tissues via numerous plasmodesmata. The absence of fibers and sclereids, the presence of phenolic idioblasts and the abundance and diversity of protein inclusions in the sieve tube members are remarkable features of the phloem. Pitted vessel elements, parenchyma cells with abundant cytoplasm and living fibriform elements characterize the xylem. The lack of lignified tissues and extensive symplastic continuity by plasmodesmata are remarkable features of the vascular system of pulvini of the all studied species. (c) 2007 Elsevier Ltd. All rights reserved.

Differential vascular adaptive response to stress exposure in male and female rats: Role of gonadal hormones and endothelial cells

Although there are reports concerning a vascular adaptive response to stress in males, this is not yet defined in females. The aim of this study was to delineate functional gender differences in the rat vascular adaptive response to stress and to determine the ability of sex hormones to modulate the stress-induced vascular adaptive response. Responses to noradrenaline were evaluated in aortas, with and without endothelium, from intact, gonadectomized and gonadectomized-hormone-replaced males and females submitted or not to stress (2-h immobilization). Reactivity of the aorta of stressed and non-stressed intact males and females (n = 6-14 per group) was also examined in the presence of L-NAME or indomethacin. Stress decreased and gonadectomy increased maximal responses to noradrenaline in aortas with intact endothelium from both genders. Stress also reduced noradrenaline potency in males. In females, but not males, stress decreased the gonadectomy-induced noradrenaline hyper-reactivity to near that of intact non-stressed rats. Hormone replacement restored the gonadectomy-induced impaired vascular adaptive response to stress. L-NAME, but not indomethacin, abolished the stress-induced decrease in aorta reactivity of males and females. None of the procedures altered reactivity of aortas denuded of endothelium. Conclusion: Stress-induced vascular adaptive responses show gender differences. The magnitude of the adaptive response is dependent on testicular hormones and involves endothelial nitric oxide-system hyperactivity.

Vascular adaptive responses to physical exercise and to stress are affected differently by nandrolone administration

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Flora vascular da Mata da Pavuna, Botucatu, SP, Brasil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Vascular flora of Serra do Japi Biological Reserve, Jundiaí, southeastern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeitos de um programa de atividade física nas funções cognitivas, equilíbrio e risco de quedas em idosos com demência de Alzheimer

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Atividade física sistematizada e sintomas de depressão na demência de Alzheimer: uma revisão sistemática

OBJETIVO: Realizar uma revisão sistemática de artigos científicos que analisaram os efeitos da atividade física sistematizada nos sintomas de depressão de pacientes com demência de Alzheimer. MÉTODOS: Foi realizada uma busca nas seguintes bases de dados: Web of Science, PubMed, PsycINFO, MedLine e Biological Abstracts, utilizando-se as seguintes palavras-chave: Alzheimer dementia , Alzheimer disease , Alzheimer, physical activity, physical exercise, motor intervention , physical therapy , exercise , aerobic , strength , fitness , depression , dysphoria , depressive symptoms e depressive episodes. Além da busca nas bases de dados, foi realizada também uma busca manual nas listas de referências dos artigos selecionados. RESULTADOS: Foram encontrados quatro estudos que preencheram todos os critérios de inclusão adotados para o presente trabalho. Dois estudos apresentaram reduções dos sintomas depressivos, e outros dois não encontraram redução desses sintomas. CONCLUSÃO: Com a realização desta revisão sistemática, observou-se que não há consenso em relação aos benefícios da atividade física aos sintomas depressivos em pacientes com demência de Alzheimer.

Atividade física sistematizada e desempenho cognitivo em idosos com demência de Alzheimer: uma revisão sistemática

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Atividade física e sintomas neuropsiquiátricos em pacientes com demência de Alzheimer

Is common the presence of neuropsychiatric symptoms in Alzheimer's disease (AD), this is resulted of anatomical and biochemical changes in the brain. The objective of present study was to look for papers relating physical activity and neuropsychiatric symptoms through a systematic review. The following data bases was accessed: Academic Search Premier, Biological Abstracts, Medline, PsycINFO, Pubmed, Scielo, Science direct on line, Sport Discus and Web of Science, using the following key-words: (Neuropsychiatric disturbances OR Neuropsychiatric symptoms OR Neuropsychological disturbances OR Aberrant behavior OR Aberrant behaviour OR Behavior disturbances OR Behaviour disturbances OR Behavior management OR Behaviour management OR Disruptive behavior OR Disruptive behaviour) and (Alzheimer) and (Exercise OR Motor intervention OR training OR Physical activity OR fitness), besides crossing the references in the selected articles. Eight studies had filled the inclusion criteria. It was possible to conclude there are evidences of positive results for agitation and sleep disturbances in patients with AD. However, there's no consensus of what kind of activity is better for these patients.

Interaction between Advanced Glycation End Products Formation and Vascular Responses in Femoral and Coronary Arteries from Exercised Diabetic Rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Arterial acid-base status during digestion and following vascular infusion of NaHCO3 and HCl in the South American rattlesnake, Crotalus durissus

Digestion is associated with gastric secretion that leads to an alkalinisation of the blood, termed the alkaline tide. Numerous studies on different reptiles and amphibians show that while plasma bicarbonate concentration ([HCO3-](pl)) increases substantially during digestion, arterial pH (pHa) remains virtually unchanged, due to a concurrent rise in arterial PCO2 (PaCO2) caused by a relative hypoventilation. This has led to the suggestion that postprandial amphibians and reptiles regulate pHa rather than PaCO2.Here we characterize blood gases in the South American rattlesnake (Crotalus durissus) during digestion and following systemic infusions of NaHCO3 and HCl in fasting animals to induce a metabolic alkalosis or acidosis in fasting animals. The magnitude of these acid-base disturbances were similar in magnitude to that mediated by digestion and exercise. Plasma [HCOT] increased from 18.4+/-1.5 to 23.7+/-1.0 mmol L-1 during digestion and was accompanied by a respiratory compensation where PaCO2 increased from 13.0+/-0.7 to 19.1+/-1.4 mm Hg at 24 h. As a result, pHa decreased slightly, but were significantly below fasting levels 36 h into digestion. Infusion of NaHCO3 (7 mmol kg(-1)) resulted in a 10 mmol L-1 increase in plasma [HCO3-] within 1 h and was accompanied by a rapid elevation of pHa (from 7.58+/-0.01 to 7.78+/-0.02). PaCO2, however, did not change following HCO3- infusion, which indicates a lack of respiratory compensation. Following infusion of HCl (4 mmol kg(-1)), plasma pHa decreased by 0.07 units and [HCO3-](pl) was reduced by 4.6 mmol L-1 within the first 3 h. PaCO2, however, was not affected and there was no evidence for respiratory compensation.Our data show that digesting rattlesnakes exhibit respiratory compensations to the alkaline tide, whereas artificially induced metabolic acid-base disturbances of same magnitude remain uncompensated. It seems difficult to envision that the central and peripheral chemoreceptors would experience different stimuli during these conditions. One explanation for the different ventilatory responses could be that digestion induces a more relaxed state with low responsiveness to ventilatory stimuli. (C) 2005 Elsevier B.V. All rights reserved.

Heat Exchange from the Toucan Bill Reveals a Controllable Vascular Thermal Radiator

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)