395 resultados para New occurrence
Resumo:
Histoplasmosis is a pulmonary disease characterised by chronic granulomatous and suppurative inflammatory reactions caused by Histoplasma capsulatum. Regarding new therapies to control fungal infections, the aim of this study was to investigate whether pulmonary administration of leukotriene B(4) (LTB(4))-loaded microspheres (MS) could confer protection to 5-lipoxygenase knockout (5-LO(-/-)) mice infected by H. capsulatum. In this study, MS containing LTB4 were administered intranasally to mice infected by H. capsulatum. On Day 14 after the infection, fungal recovery from the lungs and histology were evaluated and inflammatory cytokines were measured. Pulmonary administration of LTB(4)-loaded MS was able to reduce fungal recovery from infected lungs. Production of important inflammatory cytokines related to host defence was augmented following MS administration to the lungs. Lung histology also showed that infected mice presented a clear reduction in the fungal burden following the pulmonary release of LTB4 from MS. Our study provides evidence that the proposed biodegradable microparticulate system, which can release LTB4 to the lungs, can be employed as therapy, enhancing the antimicrobial activity of host cells during histoplasmosis. (C) 2009 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.
Resumo:
An L-amino acid oxidase (Bp-LAAO) from Bothrops pauloensis snake venom was highly purified using sequential chromatography steps on CM-Sepharose, Phenyl-Sepharose CL4B, Benzamidine Sepharose and C18 reverse-phase HPLC. Purified Bp-LAAO showed to be a homodimeric acidic glycoprotein with molecular weight around 65 kDa under reducing conditions in SDS-PAGE. The best substrates for Bp-LAAO were L-Met, L-Leu, L-Phe and L-Ile and the enzyme showed a strong reduction of its catalytic activity upon L-Met and L-Phe substrates at extreme temperatures. Bp-LAAO showed leishmanicidal, antitumoral and bactericidal activities dose dependently. Bp-LAAO induced platelet aggregation in platelet-rich plasma and this activity was inhibited by catalase. Bp-LAAC-cDNA of 1548 bp codified a mature protein with 516 amino acid residues corresponding to a theoretical isoelectric point and molecular weight of 6.3 and 58 kDa, respectively. Additionally, structural and phylogenetic studies identified residues under positive selection and their probable location in Elp-LAAO and other snake venom LAAOs (svLAAOs). Structural and functional investigations of these enzymes can contribute to the advancement of toxinology and to the elaboration of novel therapeutic agents. (C) 2009 Elsevier Masson SAS. All rights reserved.
Resumo:
Neospora caninum is an Apicomplexan protozoan that has the dog as a definitive host and cattle (among other animals) as intermediate hosts. It causes encephalopathy in dogs and abortion in cows, with significant loss in worldwide livestock. As any Apicomplexan, the parasite invades the cells using proteins contained in the phylum-specific organelles, like the micronemes, rhoptries and dense granules. The aim of this study was the characterization of a homologue (denominated NcMIC2-like1) of N. caninum thrombospondin-related anonymous protein (NcMIC2), a micronemal protein previously shown to be involved in the attachment and connection with the intracellular motor responsible for the active process of invasion. A polyclonal antiserum raised against the recombinant NcMIC2-like1 functional core (thrombospondin and integrin domains) recognized the native form of NcMIC2-like1, inhibited the in vitro invasion process and localized NcMIC2-like1 at the apical complex of the parasite by confocal immunofluorescence, indicating its micronemal localization. The new molecule, NcMIC2-like1, has features that differentiates it from NcMIC2 in a substantial way to be considered a homologue dagger.
Resumo:
The objective of this investigation was to examine in a systematic manner the influence of plasma protein binding on in vivo pharmacodynamics. Comparative pharmacokinetic-pharmacodynamic studies with four beta blockers were performed in conscious rats, using heart rate under isoprenaline-induced tachycardia as a pharmacodynamic endpoint. A recently proposed mechanism-based agonist-antagonist interaction model was used to obtain in vivo estimates of receptor affinities (K(B),(vivo)). These values were compared with in vitro affinities (K(B),(vitro)) on the basis of both total and free drug concentrations. For the total drug concentrations, the K(B),(vivo) estimates were 26, 13, 6.5 and 0.89 nM for S(-)-atenolol, S(-)-propranolol, S(-)-metoprolol and timolol. The K(B),(vivo) estimates on the basis of the free concentrations were 25, 2.0, 5.2 and 0.56 nM, respectively. The K(B),(vivo)-K(B),(vitro) correlation for total drug concentrations clearly deviated from the line of identity, especially for the most highly bound drug S(-)-propranolol (ratio K(B),(vivo)/K(B),(vitro) similar to 6.8). For the free drug, the correlation approximated the line of identity. Using this model, for beta-blockers the free plasma concentration appears to be the best predictor of in vivo pharmacodynamics. (C) 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:3816-3828, 2009
Resumo:
Brazilian social thought draws on the inspiration of past masters the common denominator of whose work is probably a deep humanism. Confronting the challenges of a fluid, ever-changing reality is now a matter of survival. The idea of climate change has made the environment, long relegated to second place, a matter of much wider interest and concern. The other great problem is poverty, and here, while there have been undeniable advances, much remains to be done. The main challenge is producing forms of social organization that will allow ordinary citizens to have an impact on what really matters. Developing policy in these areas has engaged the efforts of a wide range of experts from a variety of fields. Whereas university-educated intellectuals once formed an intelligentsia, today they are engaged in practical politics and much more often function as agents who link social actors together than as mere elaborators of theories.
Resumo:
Overcommitment of development capacity or development resource deficiencies are important problems in new product development (NPD). Existing approaches to development resource planning have largely neglected the issue of resource magnitude required for NPD. This research aims to fill the void by developing a simple higher-level aggregate model based on an intuitive idea: The number of new product families that a firm can effectively undertake is bound by the complexity of its products or systems and the total amount of resources allocated to NPD. This study examines three manufacturing companies to verify the proposed model. The empirical results confirm the study`s initial hypothesis: The more complex the product family, the smaller the number of product families that are launched per unit of revenue. Several suggestions and implications for managing NPD resources are discussed, such as how this study`s model can establish an upper limit for the capacity to develop and launch new product families.
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This article tests the hypothesis of opportunistic and partisan cycle models using a new large data set of Brazilian municipalities over the 1989-2005 period. The results show an increase in total and current expenditures and a decrease in municipal investments, local tax revenues, and budget surplus in election years. They also show that partisan ideology exerts a relative influence on the performance of the local public accounts. These results confirm that both opportunistic and partisan cycles have occurred in the management of the budgets of Brazilian municipalities after the end of the military government.
Resumo:
Many models exist in the literature to explain the success of technological innovation. However, no studies have been made regarding graphic formats representing the technological innovation models and their impact, or on the understanding of these models by non-specialists in technology management. Thus, the main objective of this paper is to propose a new graphic configuration to represent the technological innovation management. Based on the literature, the innovation model is presented in the traditional format. Next, the same model is designed in the graphic format - named `the see-saw of competitiveness` - showing the interfaces among the identified factors. The two graphic formats were compared by a group of graduate students in terms of the ease in understanding the conceptual model of innovation. The statistical analysis shows that the seesaw of competitiveness is preferred.
Resumo:
This paper uses a unique new data set on manufacturing firms in Brazil and India to estimate production functions, augmented by information and communications technology (ICT). We find a strong positive association between ICT capital and productivity in both countries that is robust to several different specification tests. The paper also breaks new ground when using the Indian data to investigate the effect of the institutional and policy environment on ICT capital investment and productivity. We find that poorer infrastructure quality and labor market policy are associated with lower levels of ICT adoption, while poorer infrastructure is also associated with lower returns to investment.
Resumo:
For more than 30 million years, in early Mesozoic Pangea, ""rauisuchian"" archosaurs were the apex predators in most terrestrial ecosystems, but their biology and evolutionary history remain poorly understood. We describe a new ""rauisuchian"" based on ten individuals found in a single locality from the Middle Triassic (Ladinian) Santa Maria Formation of southern Brazil. Nine articulated and associated skeletons were discovered, three of which have nearly complete skulls. Along with sedimentological and taphonomic data, this suggests that those highly successful predators exhibited some kind of intraspecific interaction. Other monotaxic assemblages of Triassic archosaurs are Late Triassic (Norian-Rhaetian) in age, approximately 10 million years younger than the material described here. Indeed, the studied assemblage may represent the earliest evidence of gregariousness among archosaurs, adding to our knowledge on the origin of a behavior pattern typical of extant taxa.
Resumo:
Rhamdella cainguae, a new species of the family Heptapteridae is described from the Arroyo Cuna-Piru, a tributary of the Rio Parana, in the subtropical forest of Misiones, northeastern Argentina. The presence of a large differentiated ovoid area on the supraorbital laterosensory canal along the frontal-sphenotic boundary, delimited by the slender dorsal walls of the bones, and with no foramen for a laterosensory branch, is an autapomorphy for R. cainguae. A detailed description of the skeleton and laterosensory system of R. cainguae is provided. The genus Rhamdella is rediagnosed on the basis of three autapomorphies: a very large opening in the frontal for the exit of the s6 ( epiphyseal) branch of the supraorbital laterosensory canal ( reversed in R. rusbyi), a large optic foramen, and a dark stripe along the lateral surface of the body ( reversed in R. rusbyi). Rhamdella is considered to be the sister group of a large heptapterid clade composed of the Nemuroglanis sub-clade plus the genera Brachyglanis, Gladioglanis, Leptorhamdia, and Myoglanis. Rhamdella is herein restricted to five valid species: R. aymarae, R. cainguae, R. eriarcha, R. longiuscula, and R. rusbyi. A sister group relationship between R. aymarae and R. rusbyi is supported by three synapomorphies. Rhamdella cainguae shares 12 apomorphic features with R. eriarcha and R. longiuscula.
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Kuhlmanniodendron Fiaschi & Groppo, a new genus of the tribe Lindackerieae (Achariaceae sensu lato) is created to accommodate Carpotroche apterocarpa Kuhlm, a species previously described based on incomplete floriferous and fruiting material from the rainforests of Espirito Santo state, eastern Brazil. The genus is defined by a unique set of character states, including leaves with Clusia-like venation and scaly trichomes, flowers with glabrous stamen filaments and three free styles, and indehiscent fruits with a smooth surface (sometimes with vertical ribs when dried). A description and illustration are provided, with comments on geographical distribution, phenology and generic relationships, and an emended key to neotropical genera of Lindackerieae. (c) 2008 The Linnean Society of London.
Resumo:
We aimed to study patterns of variation and factors influencing the evolutionary dynamics of a satellite DNA, pBuM, in all seven Drosophila species from the buzzatii cluster (repleta group). We analyzed 117 alpha pBuM-1 (monomer length 190 bp) and 119 composite alpha/beta (370 bp) pBuM-2 repeats and determined the chromosome location and long-range organization on DNA fibers of major sequence variants. Such combined methodologies in the study of satDNAs have been used in very few organisms. In most species, concerted evolution is linked to high copy number of pBuM repeats. Species presenting low-abundance and scattered distributed pBuM repeats did not undergo concerted evolution and maintained part of the ancestral inter-repeat variability. The alpha and alpha/beta repeats colocalized in heterochromatic regions and were distributed on multiple chromosomes, with notable differences between species. High-resolution FISH revealed array sizes of a few kilobases to over 0.7 Mb and mutual arrangements of alpha and alpha/beta repeats along the same DNA fibers, but with considerable changes in the amount of each variant across species. From sequence, chromosomal and phylogenetic data, we could infer that homogenization and amplification events involved both new and ancestral pBuM variants. Altogether, the data on the structure and organization of the pBuM satDNA give insights into genome evolution including mechanisms that contribute to concerted evolution and diversification.
Resumo:
Chetoneura shennonggongensis Amorim & Niu, sp. n., inhabiting caves in East China, is described based on the adult male and female, plus larva. Chetoneura Colless, previously associated with Orfelia and known from a single species from caves in Malaysia, is formally transferred to the Keroplatini. This is the first description of the larva and of the general biology of the genus. The larva of this new species is suspended in a roughly horizontal hammock of silken threads amidst mucous coated snare threads from the roof of caves, but is not bioluminescent as some species of other genera in Keroplatidae ( e. g., Arachnocampa, Keroplatus, and Orfelia). A key to separate both species of the genus is provided. The position of the genus within the Keroplatini is considered. Chetoneura is considered to be closely related to a clade containing Heteropterna and Ctenoceridion.
Resumo:
In insect societies, workers often try to challenge the reproductive monopoly of the queen by laying their own eggs. Successful worker reproduction, however, is frequently prevented by queen policing or worker policing, whereby either the mother queen or non-reproductive workers selectively kill worker-laid eggs. Recently, a third mechanism-""selfish"" worker policing-has also been described in which the workers selectively police worker-laid eggs but also lay eggs themselves. Here, we present results from the monogynous wasp Dolichovespula norwegica, which show that all three kinds of policing-queen policing, worker policing and ""selfish"" worker policing-co-occur. The net effect of these three kinds of policing collectively favoured the queen`s reproduction, as within 1 day 44% of the worker-laid eggs versus only 8% of the queen-laid eggs were eaten. Of the worker-laid eggs that were killed by workers, approximately two thirds were eaten by the reproductive workers even though these made up only a small proportion, 8%, of the work force. This means that policing workers obtained both direct fitness benefits as well as indirect (inclusive) fitness. In addition, we show that worker policing was carried out by a limited, specialised set of workers that was estimated to constitute approximately one quarter of the whole colony and of which 66% were non-reproductive.