3 research outputs found
Structural and functional reorganization of propriospinal connections promotes functional recovery after spinal cord injury
Get PDFAxonal regeneration and fiber regrowth is limited in the adult central nervous system, but research over the last decades has revealed a high intrinsic capacity of brain and spinal cord circuits to adapt and reorganize after smaller injuries or denervation. Short-distance fiber growth and synaptic rewiring was found in cortex, brain stem and spinal cord and could be associated with restoration of sensorimotor functions that were impaired by the injury. Such processes of structural plasticity were initially observed in the corticospinal system following spinal cord injury or stroke, but recent studies showed an equally high potential for structural and functional reorganization in reticulospinal, rubrospinal or propriospinal projections. Here we review the lesion-induced plastic changes in the propriospinal pathways, and we argue that they represent a key mechanism triggering sensorimotor recovery upon incomplete spinal cord injury. The formation or strengthening of spinal detour pathways bypassing supraspinal commands around the lesion site to the denervated spinal cord were identified as prominent neural substrate inducing substantial motor recovery in different species from mice to primates. Indications for the existence of propriospinal bypasses were also found in humans after cortical stroke. It is mandatory for current research to dissect the biological mechanisms underlying spinal circuit remodeling and to investigate how these processes can be stimulated in an optimal way by therapeutic interventions (e.g., fiber-growth enhancing interventions, rehabilitation). This knowledge will clear the way for the development of novel strategies targeting the remarkable plastic potential of propriospinal circuits to maximize functional recovery after spinal cord injury
The stereospecific synthesis of KDN α-C-glycosides by Samarium mediated reductive desulfonylation of glycosyl phenylsulfone
No full textTetrahedron Letters, 39, 5007-5010Note : if this item contains full text it may be a preprint, author manuscript, or a Gold OA copy that permits redistribution with a license such as CC BY. The final version is available through the publisher’s platform.KDN, 3-deoxy-D-glycero-D-galacto-2-nonulopyranosylonic acid, is a novel type of sialic acid in which the acetamido group at C-S of N-acetylneuraminic acid is replaced by a hydroxyl group. This ulosonic acid was first isolated from rainbow trout eggs.’ In the last 10 years, a number of KDN-glycoconjugates, exhibiting structural determinants related to human tumor-associated antigens, have been reported in mammals2 In addition, oligo/poly-KDN and KDN-glycoprotein play an important role in the binding of calcium ions.’ KDN-containing gangliosides, KDN-GM3 and KDN-GM4, have been synthesized by Hasegawa’s group and show potent inhibitor activity of cellular immune respones.https://login.libproxy.rpi.edu/login?url=https://doi.org/10.1016/S0040-4039(98)00980-
Desenvolvimento de sistema microestruturado contendo extrato padronizado de Cecropia glaziovii Sneth (Embaúba)
Get PDFDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-Graduação em Farmácia, Florianópolis, 2010A Cecropia glaziovii Sneth, popularmente conhecida como embaúba, é utilizada na medicina popular visando os efeitos diurético, anti-hipertensivo, antiinflamatório, expectorante, antiasmático e antitérmico. Esta planta é principalmente encontrada em áreas de reflorestamento e na Mata Atlântica brasileira. O presente trabalho tem como objetivo a padronização de soluções extrativas de Cecropia glaziovii e posterior-mente realizar um estudo preliminar para a encapsulação dos extratos padronizados em um sistema microestruturado. A influência dos fatores tecnológicos como teor etanólico, tempo e temperatura sobre a extração de compostos fenólicos foi avaliada para os métodos estudados, macera-ção e decocção. As soluções foram preparadas utilizando delineamento fatorial 22 com ponto central e avaliadas quanto ao seu resíduo seco, pH, teor de fenólicos totais, teor de ácido clorogênico e ácido cafeico, sendo estas duas substâncias consideradas como marcadores químicos e doseados por metodologia validada de CLAE. Os extratos obtidos com 20% de etanol apresentaram elevada concentração de ácido cafeico, substância que praticamente não está presente nas outras soluções extrativas. Em função deste resultado, foram realizados estudos para avaliação da influência da temperatura e da presença de conservante sobre os teores dos marcadores químicos durante o processo extrativo, sendo para isto elaborados dois delineamentos fatoriais 23. A atividade dos extratos brutos no tratamento do diabetes e da hipertensão foi avaliada. Os extratos obtidos por maceração foram efetivos na redução da glicemia em ratos hiperglicêmicos e apresentaram surpreendente atividade vasorrelaxadora. A atividade farmacológica serviu como fator de escolha dos extratos a serem microencapsulados em sistema polimérico, utilizando a técnica de dupla emulsão (A/O/A) com evaporação/extração do solvente. Para avaliação da interferência dos diferentes fatores na formulação das micropartículas foi utilizado o delineamento fatorial 24. As micropartículas foram avaliadas quanto ao seu rendimento, formação, aparência, tamanho e eficiência de encapsulação.Cecropia glaziovii Sneth, known as embaúba, is used in folk medicine as diuretic, antihypertensive, anti-inflammatory, expectorant, as relief for asthma and fever. This plant is mainly found in reforestation areas and Brazilian Atlantic Rain Forest. The present work aims to develop Cecropia glaziovii padronized extracts and lately perform preliminary extracts encapsulation in microstructured system. The influence of some technological factors as ethanol concentration, time and temperature extraction above phenolic compounds was evaluated in studied methods, maceration and decoction. The extractive solutions were prepared employing a 22 factorial design with central point and evaluated as dry residue, pH, total phenolics content, chlorogenic and caffeic acids concentration, both considered as chemical markers and the assay was carried out by HPLC validated methodology. In the 20% ethanolic extracts a great amount of caffeic acid was observed, compound that was not detected in the extracts with higher ethanolic concentrations. In order to investigate this result, the influence of temperature and the presence of a preservative on chemical markers content during extraction process were evaluated according to a two 23 factorial designs. The antidiabetic and antihypertensive activity of the extracts were evaluated. The extracts obtained by maceration reduced glucose level on blood samples in hyperglycemic rats and showed surprisingly vasodilator activity. The pharmacological activity was used as a factor to choose the extracts for microencapsulation in polymeric system, using double emulsion technique (W/O/W) with solvent evaporation/extraction. In order to investigate the influence of different factors in microparticles formulation a 24 factorial design was performed. Microparticles were evaluated as yield, formation, aspect, size and encapsulation efficiency
