868 research outputs found
In vitro culture of Annona emarginata: a rootstock for commercial annonaceae species
Annona emarginata is a native fruit tree in the Brazilian Cerrado which, unlike the commercial species, does not present a high fruit quality. On the other hand, it stands out based on its rootstock value. However, there are some problems that hinder the largescale production of Annona emarginata seedlings for use as a rootstock. In order to overcome these difficulties, micropropagation has become a viable alternative for the rapid and efficient propagation of Annona spp, but Annona emarginata micropropagation has not yet been reported. Therefore, the aim of this study was to initiate Annona emarginata in vitro growth. For axillary shoot proliferation, in vitro nodal segments of 0.5 cm were transferred to MS or WPM supplemented with BA at different concentrations. Nodal segments were also cultured on WPM medium with ranging concentrations of different plant growth regulators, aiming for either shoot elongation or rooting. The results showed that the use of 1 ”M BA in WPM medium is recommended for in vitro multiplication of Annona emarginata. This is based on the low adventitious shoot formation, combined with a higher number of buds and leaves. The use of GA3 at any concentration tested induced the formation of malformed plants. Root formation could not be stimulated, regardless the duration of auxin treatment
Coping with suboptimal water temperature: modifications in blood parameters, body composition, and postingestive-driven diet selection in Nile tilapia fed two vegetable oil blends
The world tilapia production faces seasonal variations. However, very few nutritional studies have addressed suboptimal temperature. We evaluated the effect of two temperatures (20 or 30âŻÂ°C) and two vegetable oil blends (one rich in corn oil (COR) and one rich linseed oil (LIN)) on tilapia growth, body composition, and blood parameters using a 2 Ă 2 factorial design with the following treatments: COR-20; LIN-20; COR-30; LIN-30 (Trial 1). In addition, we also evaluated the effect of postingestive signals of dietary oils when the organoleptic properties of diets were isolated (Trial 2). In the Trial 1, 256 fish (15.36âŻÂ±âŻ0.14âŻg) were placed in 16 aquariums and submitted during 30âŻdays to the 2 Ă 2 factorial designs: COR-20; LIN-20; COR-30; LIN-30. The temperatures were established in two independent water recirculation systems. In the Trial 2, 96 fish (34.02âŻÂ±âŻ0.79âŻg) were placed in 12 aquariums and subjected to the same experimental design of Trial 1, but to evaluate fish feeding behavior. They were allowed to select the encapsulated diets provided in different feeding halls to evaluate if diet preferences are influenced by postingestive signals. As the Trial 1 results show, diets had no significant effects on growth, dietary protein use, and body centesimal composition, but 30âŻÂ°C induced the best performance and protein deposition (PâŻ<âŻ0.05). LIN-20 showed lower very-low-density lipoprotein and cortisol, but higher high-density lipoprotein (HDL), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and triglycerides (TG) than COR-20 (PâŻ<âŻ0.05). COR-30 presented higher HDL, AST, ALT, TG, and cortisol than LIN-30. The fish fed COR showed lower C20:5n-3 (EPA) and higher n-6 than fish fed LIN (PâŻ<âŻ0.05). The fish fed LIN had high n-3 highly unsaturated fatty acid. â polyunsaturated fatty acid was higher at 30âŻÂ°C. Finally, the tilapia in Trial 2 showed clear diet intake regulation and preference for LIN (PâŻ<âŻ0.05), regardless of temperature. In short, lipid sources had no influence on tilapia performance; however, temperature affects carcass lipid deposition as well as fatty acids profile. Notably, the preference for linseed oil can suggest nutritional metabolic issues, contributing to animal behavior knowledge
Inclusion of extracellular matrix molecules and necrostatin-1 in the intracapsular environment of alginate-based microcapsules synergistically protects pancreatic ÎČ cells against cytokine-induced inflammatory stress
Immunoisolation of pancreatic islets in alginate-based microcapsules is a promising approach for grafting of islets in absence of immunosuppression. However, loss and damage to the extracellular matrix (ECM) during islet isolation enhance susceptibility of islets for inflammatory stress. In this study, a combined strategy was applied to reduce this stress by incorporating ECM components (collagen type IV/RGD) and necroptosis inhibitor, necrostatin-1 (Nec-1) in alginate-based microcapsules in vitro. To demonstrate efficacy, viability and function of MIN6 ÎČ-cells and human islets in capsules with collagen type IV/RGD and/or Nec-1 was investigated in presence and absence of IL-1ÎČ, IFN-Îł and TNF-α. The combination of collagen type IV/RGD and Nec-1 had higher protective effects than the molecules alone. Presence of collagen type IV/RGD and Nec-1 in the intracapsular environment reduced cytokine-induced overproduction of free radical species and unfavorable shifts in mitochondrial dynamics. In addition, the ECM components collagen type IV/RGD prevented a cytokine induced suppression of the FAK/Akt pathway. Our data indicate that the inclusion of collagen type IV/RGD and Nec-1 in the intracapsular environment prevents islet-cell loss when exposed to inflammatory stress, which might contribute to higher survival of ÎČ-cells in the immediate period after transplantation. This approach of inclusion of stress reducing agents in the intracapsular environment of immunoisolating devices may be an effective way to enhance the longevity of encapsulated islet grafts. Statement of significance: Islet-cells in immunoisolated alginate-based microcapsules are very susceptible to inflammatory stress which impacts long-term survival of islet grafts. Here we show that incorporation of ECM components (collagen type IV/RGD) and necrostatin-1 (Nec-1) in the intracapsular environment of alginate-based capsules attenuates this susceptibility and promotes islet-cell survival. This effect induced by collagen type IV/RGD and Nec-1 was probably due to lowering free radical production, preventing mitochondrial dysfunction and by maintaining ECM/integrin/FAK/Akt signaling and Nec-1/RIP1/RIP3 signaling. Our study provides an effective strategy to extend longevity of islet grafts which might be of great potential for future clinical application of immunoisolated cells
Trypanocidal Activity Of Brazilian Plants Against Epimastigote Forms From Y And Bolivia Strains Of Trypanosoma Cruzi
Chagas disease is one of the main public health problems in Latin America. Since the available treatments for this disease are not effective in providing cure, the screening of potential antiprotozoal agents is essential, mainly of those obtained from natural sources. This study aimed to provide an evaluation of the trypanocidal activity of 92 ethanol extracts from species belonging to the families Annonaceae, Apiaceae, Cucurbitaceae, Lamiaceae, Lauraceae, Moraceae, Nyctaginaceae, and Verbenaceae against the Y and Bolivia strains of Trypanosoma cruzi. Additionally, cytotoxic activity on LLCMK2 fibroblasts was evaluated. Both the trypanocidal activity and cytotoxicity were evaluated using the MTT method, in the following concentrations: 500, 350, 250, and 100 ÎŒg/mL. Benznidazole was used for positive control. The best results among the 92 samples evaluated were obtained with ethanol extracts of Ocotea paranapiacabensis (Am93) and Aegiphila lhotzkiana (Am160). Am93 showed trypanocidal activity against epimastigote forms of the Bolivia strain and was moderately toxic to LLCMK2 cells, its Selectivity Index (SI) being 14.56, while Am160 showed moderate trypanocidal activity against the Bolivia strain and moderate toxicicity, its SI being equal to 1.15. The screening of Brazilian plants has indicated the potential effect of ethanol extracts obtained from Ocotea paranapiacabensis and Aegiphila lhotzkiana against Chagas disease.223528533Bastos, J.K., Albuquerque, S., Silva, M.L.A., Evaluation of the trypanocidal activity of lignans isolated from the leaves of Zanthoxylum naranjillo (1999) Planta Med, 65, pp. 1-4Batista Jr., J.M., Lopes, A.A., AmbrĂłsio, D.L., Regasini, L.O., Kato, M.J., Bolzani, V.S., Cicarelli, R.M., Furlan, M., Natural chromenes and chromene derivatives as potencial antitrypanosomal agents (2008) Biol Pharm Bull, 31, pp. 538-540Botsaris, A., Plants used traditionally to treat malaria in Brazil: The archives of Flora Medicinal (2007) J Ethnobiol Ethnomed, 1, p. 18Buainain, A., Giazzi, J.F., Belda Neto, F.M., Martini, A.S., Rosa, J.A., Pozetti, G.L., Estudo da atividade de extratos vegetais sobre o desenvolvimento de Trypanosoma cruzi em meio lĂquido de Warren (1992) Rev Cien Farm, 14, pp. 93-102Cabral, M.M., Barbosa-Filho, J.M., Maia, G.L., Chaves, M.C., Braga, M.V., de Souza, W., Neolignans from plants in northeastern Brazil (Lauraceae) with activity against (2010) Trypanosoma Cruzi. Exp Parasitol, 124, pp. 319-324Costa-Lotufo, L.V., Silveira, E.R., Barros, M.C., Lima, M.A., de Moraes, M.E., de Moraes, M.O., Pessoa, C., Antiproliferative effects of abietane diterpenes from aegiphilla lhotzkyana (2004) Planta Med, 70, pp. 180-182Cotinguiba, F., Regasini, L.O., Bolzani, V.S., Debonsi, H.M., Passerini, D.O., Cicarelli, R.M.B., Kato, M.J., Furlan, M., Piperamides and their derivatives as potential antitrypanosomal agents (2009) Med Chem Res, 18, pp. 703-711Coura, J.R., Castro, S.L., A critical review on Chagas disease chemotherapy (2002) Mem I Oswaldo Cruz, 97, pp. 3-24Coura, J.R., Present situation and new strategies for Chagas disease chemotherapy: A proposal (2009) Mem I Oswaldo Cruz, 104, pp. 549-554Fernandes, O., Souto, R.P., Castro, J.A., Pereira, J.B., Fernandes, N.C., Junqueira, A.C., Naiff, R.D., Coura, J.R., Brazilian isolates of Trypanosoma cruzi from humans and triatomines classified into two lineages using mini-exon and ribosomal RNA sequences (1998) Am J Trop Med Hyg, 58, pp. 807-811Fournet, A., Ferreira, M.E., Rojas de Arias, A., Guy, I., Guinaudeau, H., Heinzen, H., Phytochemical and antiprotozoal activity of (2007) Ocotea Lancifolia. Fitoterapia, 78, pp. 382-384Lopes, A.A., LĂłpez, S.N., Regasini, L.O., Batista, J.M., AmbrĂłsio, D.L., Kato, M.J., da Silva, B.V., Furlan, M., In vitro activity of compounds isolated from Piper crassinervium against Trypanosoma cruzi (2008) Nat Prod Res, 22, pp. 1040-1046Macedo, A.M., Oliveira, R.P., Pena, S.D.J., Chagas disease: Role of parasite genetic variation in pathogenesis (2002) Exp Mol Med, 4, pp. 1-16Muelas-Serrano, S., Nogal-Ruiz, J.J., GĂłmez-Barrio, A., Setting of a colorimetric method to determine the viability of Trypanosoma cruzi epimastigotes (2000) Parasitol Res, 86, pp. 999-1002Nwaka, S., Ridley, R.G., Virtual drug discovery and development for neglected diseases through publicprivate partnerships (2003) Nat Rev Drug Discov, 2, pp. 919-928Osorio, E., Arango, G.J., JimĂ©nez, N., Alzate, F., Ruiz, G., GutiĂ©rrez, D., Paco, M.A., Robledo, S., Antiprotozoal and cytotoxic activities in vitro of Colombian Annonaceae (2007) J Ethnopharmacol, 111, pp. 630-635Regasini, L.O., Cotinguiba, F., Passerini, G.D., Bolzani, V.S., Cicarelli, R.M.B., Kato, M.J., Furlan, M., Trypanocidal activity of Piper arboreum and Piper tuberculatum (Piperaceae) (2009) Rev Bras Farmacog, 19, pp. 199-203Saraiva, J., Vega, C., Rolon, M., da Silva, R., Silva, M.L., Donate, P.M., Bastos, J.K., de Albuquerque, S., In vitro and in vivo activity of lignan lactones derivatives against Trypanosoma cruzi (2007) Parasitol Res, 100, pp. 791-795Tibayrenc, M., Ayala, F.J., The clonal theory of parasitic protozoa: 12 years on (2002) Trends Parasitol, 18, pp. 405-410(2010), http://www.who.int/mediacentre/factsheets/fs340/en/index.html, World Health Organization 2010, accessed in Au
Bregman Voronoi Diagrams: Properties, Algorithms and Applications
The Voronoi diagram of a finite set of objects is a fundamental geometric
structure that subdivides the embedding space into regions, each region
consisting of the points that are closer to a given object than to the others.
We may define many variants of Voronoi diagrams depending on the class of
objects, the distance functions and the embedding space. In this paper, we
investigate a framework for defining and building Voronoi diagrams for a broad
class of distance functions called Bregman divergences. Bregman divergences
include not only the traditional (squared) Euclidean distance but also various
divergence measures based on entropic functions. Accordingly, Bregman Voronoi
diagrams allow to define information-theoretic Voronoi diagrams in statistical
parametric spaces based on the relative entropy of distributions. We define
several types of Bregman diagrams, establish correspondences between those
diagrams (using the Legendre transformation), and show how to compute them
efficiently. We also introduce extensions of these diagrams, e.g. k-order and
k-bag Bregman Voronoi diagrams, and introduce Bregman triangulations of a set
of points and their connexion with Bregman Voronoi diagrams. We show that these
triangulations capture many of the properties of the celebrated Delaunay
triangulation. Finally, we give some applications of Bregman Voronoi diagrams
which are of interest in the context of computational geometry and machine
learning.Comment: Extend the proceedings abstract of SODA 2007 (46 pages, 15 figures
Root dentinal microcracks: a post-extraction experimental phenomenon?
Aim
To investigate the prevalence, location and pattern of preâexisting microcracks in nonâendodontically treated teeth from fresh cadavers. Microâcomputed tomography (microâCT) technology was used as the analytical tool enabling full screening of the root dentine with the teeth retained in their original alveolar socket.
Methodology
As a pilot study and to validate the present method, a series of 4 highâresolution scans were performed on one boneâblock specimen with teeth collected postâmortem: (i) entire boneâblock including the teeth, (ii) second molar tooth extracted atraumatically from the boneâblock, (iii) extracted tooth dehydrated to induce dentinal defects and (iv) entire boneâblock following reinsertion of the extracted tooth into its matching alveolar socket. In the main study, fortyâtwo dentoalveolar maxillary and mandibular boneâblocks each containing 3â5 adjacent teeth (a total of 178 teeth) were collected postâmortem and scanned in a microâCT device. All crossâsection images of the 178 teeth (n = 65 530) were screened from the cementoenamel junction to the apex to identify the presence of dentinal defects.
Results
In the pilot study, the microcracks observable when the dehydrated tooth was outside the boneâblock remained detectable when the entire boneâblock plus reinserted tooth was scanned. This means that the screening process revealed the presence of the same microcracks in both experimental situations (the tooth outside and inside the maxillary boneâblock). From a total of 178 teeth in the boneâblocks removed from cadavers, 65 530 crossâsectional images were analysed and no dentinal microcracks were detected.
Conclusions
This in situ cadaveric model revealed the lack of preâexisting dentinal microcracks in nonâendodontically treated teeth. Thus, the finding of dentinal microcracks observed in previous crossâsectional images of stored extracted teeth is unsound and not valid. It should be assumed that microcracks observed in stored extracted teeth subjected to root canal procedures are a result of the extraction process and/or the postâextraction storage conditions. Therefore, as a consequence, the presence of such dentinal microcracks in stored extracted teeth â observable in crossâsectional images of the roots â should be referred to as experimental dentinal microcracks
Cardiovascular training adaptations in Criollo breed horses: biochemical markers and morphofunctional parameters
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