Transcriptome analysis of Loxosceles laeta (Araneae, Sicariidae) spider venomous gland using expressed sequence tags

<p>Abstract</p> <p>Background</p> <p>The bite of spiders belonging to the genus <it>Loxosceles </it>can induce a variety of clinical symptoms, including dermonecrosis, thrombosis, vascular leakage, haemolysis, and persistent inflammation. In order to examine the transcripts expressed in venom gland of <it>Loxosceles laeta </it>spider and to unveil the potential of its products on cellular structure and functional aspects, we generated 3,008 expressed sequence tags (ESTs) from a cDNA library.</p> <p>Results</p> <p>All ESTs were clustered into 1,357 clusters, of which 16.4% of the total ESTs belong to recognized toxin-coding sequences, being the Sphingomyelinases D the most abundant transcript; 14.5% include "possible toxins", whose transcripts correspond to metalloproteinases, serinoproteinases, hyaluronidases, lipases, C-lectins, cystein peptidases and inhibitors. Thirty three percent of the ESTs are similar to cellular transcripts, being the major part represented by molecules involved in gene and protein expression, reflecting the specialization of this tissue for protein synthesis. In addition, a considerable number of sequences, 25%, has no significant similarity to any known sequence.</p> <p>Conclusion</p> <p>This study provides a first global view of the gene expression scenario of the venom gland of <it>L. laeta </it>described so far, indicating the molecular bases of its venom composition.</p

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Physicochemical aspects involved in methotrexate release kinetics from biodegradable spray-dried chitosan microparticles

Spray dried methotrexate (MTX) loaded chitosan microparticles were prepared using different drug/copolymer ratios (9%, 18%, 27% and 45% w/w). The physicochemical aspects were assessed in order to select particles that were able to induce a sustained drug release effect. Particles were successfully produced which exhibited desired physicochemical aspects such as spherical shape and high drug loading. XRD and FT-IR analysis demonstrated that drug is not bound to copolymer and is only homogeneously dispersed in an amorphous state into polymeric matrix. Even the particles with higher drug loading levels presented a sustained drug release profile, which were mathematically modeled using adjusted Higuchi model. The drug release occurred predominantly with drug dissolution and diffusion through swollen polymeric matrix, with the slowest release occurring with particles containing 9% of drug, demonstrating an interesting and promising drug delivery system for MTX. (C) 2015 Elsevier Ltd. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Interaction pathways of specific co-solvents with hydroxypropyl-β-cyclodextrin inclusion complexes with benznidazole in liquid and solid phase

The main purpose of the study was to assess the mechanism whereby the co-solvents triethanolamine (TEA) and 1-methyl-2-pyrrolidone (NMP) interacted with hydroxypropyl-beta-cyclodextrin (HP-β-CD) in ternary associations for improving the solubility and dissolution rate of the insoluble ingredient benznidazole (BNZ). In liquid phase, the solubility diagrams and Job's plot results were further explored by in silico molecular modeling and experimental 1H NMR spectroscopy studies. The structure of the inclusion complexes in the binary and ternary association were established. The competition of NMP with the drug for the HP-β-CD cavity was evidenced, while TEA stabilized the drug-CD interactions, forming ternary complexes. FTIR analysis confirmed distinct intermolecular interactions among the compounds in the different solid dispersions prepared by physical mixture (PM) and spray drying (SD). The co-solvents improved the drug dissolution performance from PM ternary associations due to their enhanced wettability of particles changing the drug-CD interaction. In addition to the SD samples exhibiting spherical particles, the co-solvents increased the crystallinity of drug in the particles and the ternary associations did not reproduce the drug dissolution rate identified in the PM samples. The experimental results proved the importance of the co-solvents to improve the drug dissolution performance from ternary complexes and established the mechanism whereby these substances worked together with the CD in a new and promising raw material. Due to the high temperature, the spray drying was not a suitable method for preparing the specific ternary complexes.Fil: de Melo, Polyanne N.. Universidade Federal do Rio Grande do Norte; BrasilFil: Barbosa, Euzébio G.. Universidade Federal do Rio Grande do Norte; BrasilFil: Garnero, Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; ArgentinaFil: de Caland, Lilia B.. Universidade Federal do Rio Grande do Norte; BrasilFil: Fernandes Pedrosa, Matheus F.. Universidade Federal do Rio Grande do Norte; BrasilFil: Longhi, Marcela Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; ArgentinaFil: da Silva Júnior, Arnóbio Antônio. Universidade Federal do Rio Grande do Norte; Brasi

Protein-Rich Fraction of Cnidoscolus urens (L.) Arthur Leaves: Enzymatic Characterization and Procoagulant and Fibrinogenolytic Activities

Proteolytic enzymes are important macromolecules in the regulation of biochemical processes in living organisms. Additionally, these versatile biomolecules have numerous applications in the industrial segment. In this study we have characterized a protein-rich fraction of Cnidoscolus urens (L.) Arthur leaves, rich in proteolytic enzymes, and evaluated its effects on the coagulation cascade. Three protein-rich fractions were obtained from the crude extract of C. urens leaves by precipitation with acetone. Fraction F1.0 showed higher proteolytic activity upon azocasein, and thus, was chosen for subsequent tests. The proteolytic activity of F1.0 on fibrinogen was dose-dependent and time-dependent. The extract demonstrated procoagulant activity on citrated plasma and reduced the APTT, not exerting effects on PT. Despite the fibrin(ogen)olytic activity, F1.0 showed no defibrinogenating activity in vivo. The fraction F1.0 did not express hemorrhagic nor hemolytic activities. The proteolytic activity was inhibited by E-64, EDTA and in the presence of metal ions, and increased when pretreated with reducing agents, suggesting that the observed activity was mostly due to cysteine proteases. Several bands with proteolytic activity were detected by zymography with gelatin, albumin and fibrinogen. The optimal enzymatic activity was observed in temperature of 60 °C and pH 5.0, demonstrating the presence of acidic proteases. In conclusion, these results could provide basis for the pharmacological application of C. urens proteases as a new source of bioactive molecules to treat bleeding and thrombotic disorders

Surfactant-cosurfactant interactions and process parameters involved in the formulation of stable and small droplet-sized benznidazole-loaded soybean O/W emulsions

The ability of different surfactant mixtures (SM) (polysorbate 80/sorbitan monooleate, 5 to 10% w/w) with cosurfactants (CO) (benzyl alcohol, ethanol, and 2-methylpyrrolidone) to produce stable benznidazole (BNZ) loaded soybean oil (SO, 10 to 30% w/w) in water (O/tW) emulsions was well assessed. Statistical tests were performed to select the best procedure parameters (temperature, shake conditions, and order inversion phases), using a phase inversion technique (PIT). Phase behavior was assessed by the pseudo-ternary phase diagram at the best HLB (9.0). Physicochemical stability was assessed at different storage conditions (4 degrees C, 25 degrees C, and 45 degrees C, with thermal stress of 24 h at each temperature, 30 days). Rheological measurements demonstrated that all SO emulsions exhibited pseudoplastic flow-type (n-0.5) liquid-like behavior (k-0.19) with the absence of storage modulus (G') and a predominance of loss modulus (G '') even for the most concentrated emulsion (30% w/w SO), and confirmed stability regarding flocculation. The droplet size remained between 42 and 61 nm (PDI inferior to 03). However, benzyl alcohol contributed to an increase in droplet size, while 2-methylpyrrolidone led to the smallest droplet size. BNZ showed a weak interaction with the oil phase, but stable SO in water emulsions was produced with small and uniform droplet size containing a soluble drug fraction about four times greater than its aqueous solubility. (C) 2014 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES