Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Control Release ; 309: 265-276, 2019 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-31362078

RESUMO

This study focuses on intra-articular (IA) drug delivery system for the treatment of knee osteoarthritis (OA). In osteoarthritic condition the synovial fluid presents pockets with lower pH environment. To take advantage of these pH differences, poly(lactic-co-glycolic acid (PLGA) nanoparticles (NPs) and pH- responsive PLGA NPs encapsulated with ammonium bicarbonate (NH4HCO3) were generated. The nanoparticles were loaded with hyaluronic acid (HA) as a possible model drug for OA and with near-infrared dye (NIR) that was used to visualize the NPs with molecular imaging techniques. These NPs were characterized by dynamic light scattering, transmission electron microscopy and compared in in vitro, in vivo and ex vivo experiments in the treatment of OA. The results indicate that the NPs were sufficiently small, displayed a uniform size distribution and were non-toxic both in vitro and in vivo. Both NPs treatment seem to induced a reduction in OA progression, with pH- responsive NPs showing the more pronounced effect. This is probably because the pockets of low pH environment in the synovial fluid trigger a burst release of the pH-responsive NPs. This result is corroborated by in vitro experiments since the pH- responsive NPs showed an extracellular burst release behavior and higher chondrocyte vitality than non-responsive NPs. This study demonstrates that PLGA NPs containing HA and NH4HCO3 are candidates for the treatment of knee OA.


Assuntos
Preparações de Ação Retardada/química , Ácido Hialurônico/administração & dosagem , Osteoartrite/tratamento farmacológico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Viscossuplementos/administração & dosagem , Animais , Bicarbonatos/química , Linhagem Celular , Corantes/administração & dosagem , Humanos , Ácido Hialurônico/uso terapêutico , Concentração de Íons de Hidrogênio , Injeções Intra-Articulares , Masculino , Camundongos Endogâmicos C57BL , Nanopartículas/química , Viscossuplementos/uso terapêutico
2.
Braz J Biol ; 73(3): 507-13, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24212690

RESUMO

The community of orchid bees (Hymenoptera: Apidae: Euglossina) was studied at an area in the transition between the Cerrado and Atlantic Forest biomes, from March, 2010 to February, 2011 in the Barroso region, state of Minas Gerais, eastern Brazil. Orchid-bee males were collected with bait traps containing three different scents (cineole, eugenol and vanillin) and with entomological nets for collecting bees on flowers. A total of 614 orchid-bee males were collected using aromatic traps, belonging to four genera and 15 species. Twenty-five female specimens belonging to two genera and at least three species were collected on flowers. Eulaema (Apeulaema) nigrita Lepeletier, 1841 was the most abundant species (50% of collected specimens), followed by Euglossa (Euglossa) truncata Rebêlo & Moure, 1996 (28%). Cineole was the most attractive compound (66.5% of males and 13 species), followed by eugenol (16% and 9 species) and vanillin (13.5% and 4 species). Eulaema (Apeulaema) marcii Nemésio, 2009 and Eufriesea auriceps (Friese, 1899) were attracted to all scents, whereas Euglossa species were collected only in cineole and eugenol.


Assuntos
Abelhas/classificação , Biodiversidade , Árvores , Animais , Brasil , Feminino , Masculino , Densidade Demográfica , Estações do Ano
3.
Persoonia ; 31: 159-78, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24761041

RESUMO

Species from Entoloma subg. Entoloma are commonly recorded from both the Northern and Southern Hemispheres and, according to literature, most of them have at least Nearctic-Palearctic distributions. However, these records are based on morphological analysis, and studies relating morphology, molecular data and geographical distribution have not been reported. In this study, we used phylogenetic species recognition criteria through gene genealogical concordance (based on nuclear ITS, LSU, rpb2 and mitochondrial SSU) to answer specific questions considering species limits in Entoloma subg. Entoloma and their geographic distribution in Europe, North America and Australasia. The studied morphotaxa belong to sect. Entoloma, namely species like the notorious poisonous E. sinuatum (E. lividum auct.), E. prunuloides (type-species of sect. Entoloma), E. nitidum and the red-listed E. bloxamii. With a few exceptions, our results reveal strong phylogeographical partitions that were previously not known. For example, no collection from Australasia proved to be conspecific with the Northern Hemisphere specimens. Almost all North American collections represent distinct and sister taxa to the European ones. And even within Europe, new lineages were uncovered for the red-listed E. bloxamii, which were previously unknown due to a broad morphological species concept. Our results clearly demonstrate the power of the phylogenetic species concept to reveal evolutionary units, to redefine the morphological limits of the species addressed and to provide insights into the evolutionary history of key morphological characters for Entoloma systematics. New taxa are described, and new combinations are made, including E. fumosobrunneum, E. pseudoprunuloides, E. ochreoprunuloides and E. caesiolamellatum. Epitypes are selected for E. prunuloides and E. bloxamii. In addition, complete descriptions are given of some other taxa used in this study for which modern descriptions are lacking, viz. E. subsinuatum, E. whiteae, E. flavifolium, E. luridum, E. bloxamii, E. madidum, E. corneri, E. callidermum and E. coeruleoviride.

4.
Persoonia ; 29: 146-201, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23606771

RESUMO

Novel species of microfungi described in the present study include the following from Australia: Catenulostroma corymbiae from Corymbia, Devriesia stirlingiae from Stirlingia, Penidiella carpentariae from Carpentaria, Phaeococcomyces eucalypti from Eucalyptus, Phialophora livistonae from Livistona, Phyllosticta aristolochiicola from Aristolochia, Clitopilus austroprunulus on sclerophyll forest litter of Eucalyptus regnans and Toxicocladosporium posoqueriae from Posoqueria. Several species are also described from South Africa, namely: Ceramothyrium podocarpi from Podocarpus, Cercospora chrysanthemoides from Chrysanthemoides, Devriesia shakazului from Aloe, Penidiella drakensbergensis from Protea, Strelitziana cliviae from Clivia and Zasmidium syzygii from Syzygium. Other species include Bipolaris microstegii from Microstegium and Synchaetomella acerina from Acer (USA), Brunneiapiospora austropalmicola from Rhopalostylis (New Zealand), Calonectria pentaseptata from Eucalyptus and Macadamia (Vietnam), Ceramothyrium melastoma from Melastoma (Indonesia), Collembolispora aristata from stream foam (Czech Republic), Devriesia imbrexigena from glazed decorative tiles (Portugal), Microcyclospora rhoicola from Rhus (Canada), Seiridium phylicae from Phylica (Tristan de Cunha, Inaccessible Island), Passalora lobeliae-fistulosis from Lobelia (Brazil) and Zymoseptoria verkleyi from Poa (The Netherlands). Valsalnicola represents a new ascomycete genus from Alnus (Austria) and Parapenidiella a new hyphomycete genus from Eucalyptus (Australia). Morphological and culture characteristics along with ITS DNA barcodes are also provided.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...