Purification And N-terminal Sequencing Of Two Presynaptic Neurotoxic Pla2, Neuwieditoxin-i And Neuwieditoxin-ii, From Bothrops Neuwiedi Pauloensis (jararaca Pintada) Venom

Two presynaptic phospholipases A2 (PLA2), neuwieditoxin-I (NeuTX-I) and neuwieditoxin-II (NeuTX-II), were isolated from the venom of Bothrops neuwiedi pauloensis (BNP). The venom was fractionated using molecular exclusion HPLC (Protein-Pak 300SW column), followed by reverse phase HPLC (μBondapak C18 column). Tricine-SDS-PAGE in the presence or absence of dithiothreitol showed that NeuTX-I and NeuTX-II had a molecular mass of approximately 14 kDa and 28kDa, respectively. At 10μg/ml, both toxins produced complete neuromuscular blockade in indirectly stimulated chick biventer cervicis isolated preparation without inhibiting the response to acetylcholine, but NeuTX-II reduced the response to KCl by 67.0±8.0% (n=3; p<0.05). NeuTX-I and NeuTX-II are probably responsible for the presynaptic neurotoxicity of BNP venom in vitro. In fact, using loose patch clamp technique for mouse phrenic nerve-diaphragm preparation, NeuTX-I produced a calcium-dependent blockade of acetylcholine release and caused appearance of giant miniature end-plate potentials (mepps), indicating a pure presynaptic action. The N-terminal sequence of NeuTX-I was DLVQFGQMILKVAGRSLPKSYGAYGCYCGWGGRGK (71% homology with bothropstoxin-II and 54% homology with caudoxin) and that of NeuTX-II was SLFEFAKMILEETKRLPFPYYGAYGCYCGWGGQGQPKDAT (92% homology with Basp-III and 62% homology with crotoxin PLA2). The fact that NeuTX-I has Q-4 (Gln-4) and both toxins have F-5 (Phe-5) and Y-28 (Tyr-28) strongly suggests that NeuTX-I and NeuTX-II are Asp49 PLA2.131103121AIRD, S.D., KAISER II, LEWIS RV., KRUGGEL WG. A complete amino acid sequence for the basic subunit of crotoxin (1986) Arch. Biochem. Biophys, 249, pp. 296-300AIRD, S.D., KRUGGEL, W.G., KAISER II, Amino acid sequence of the basic subunit of Mojave toxin from the venom of the Mojave rattlesnake (Crotalus s. scutulatus) (1990) Toxicon, 28, pp. 669-673BEGHINI, D.G., TOYAMA, M.H., HYSLOP, S., SODEK, L., NOVELLO, J.C., MARANGONI, S., Enzymatic characterization of a novel phospholipase A2 from Crotalus durissus cascavella rattlesnake (maracambóia) venom (2000) J. Protein Chem, 19, pp. 603-607BORJA-OLIVEIRA, C.R., DURIGON, A.M., VALLIN, A.C.C., TOYAMA, M.H., SOUCCAR, C., MARANGONI, S., RODRIGUES-SIMIONI, L., The pharmacological effects of Bothrops neuwiedi pauloensis (jararaca-pintada) snake venom on avian neuromuscular transmission (2003) Braz. J. Med. Biol. Res, 36, pp. 617-624BORJA-OLIVEIRA, C.R., SOARES, A.M., ZAMUNER, S.R., HYSLOP, S., GIGLIO, J.R., PRADO-FRANCESCHI, J., RODRIGUES-SIMIONI, L., Intraspecific variation in the neurotoxic and myotoxic activities of Bothrops neuwiedi snake venoms (2002) J. Venom. Anim. Toxins, 8, pp. 88-101BUCARETCHI, F., HERRERA, S.R.F., HYSLOP, S., BARACAT, E.C.E., VIEIRA, R.J., Snakebites by Bothrops spp in children in Campinas, São Paulo, Brazil (2001) Rev. Inst. Med. Trop. São Paulo, 43, pp. 329-333CHO, W., KEZDY, F.J., Chromogenic substrate and assay of phospholipase A 2 (1991) Meth. Enzymol, 197, pp. 75-79CINTRA, A.C., MARANGONI, S., OLIVEIRA, B., GIGLIO, J.R., Bothropstoxin-I: Amino acid sequence and function (1993) J. Protein Chem, 12, pp. 57-64COGO, J.C., PRADO-FRANCESCHI, J., CRUZ-HÖFLING, M.A., CORRADO, A.P., RODRIGUES-SIMIONI, L., Effects of Bothrops insularis on the mouse and chick nerve-muscle preparation (1993) Toxicon, 31, pp. 1237-1247COGO, J.C., PRADO-FRANCESCHI, J., GIGLIO, J.R., CORRADO, A.P., CRUZ-HÖFLING, M.A., DONATO, J.L., LEITE, G.B., RODRIGUES-SIMIONI, L., An unusual presynaptic action of Bothrops insularis snake venom mediated by phospholipase A2 fraction (1998) Toxicon, 36, pp. 1323-1332DE SOUSA, M.V., MORHY, L., ARNI, R.K., WARD, R.J., GUTIÉRREZ, J.M., Amino acid sequence of a myotoxic Lys-49-phospholipase A2 homologue from the venom of Cerrophidion (Bothrops) godmani (1998) Biochim. Biophys. Acta, 1384, pp. 204-208DURIGON, A.M., BORJA-OLIVEIRA, C.R., DAL, B.C., OSHIMA-FRANCO, Y., COGO, J.C., LAPA, A.J., SOUCCAR, C., RODRIGUES-SIMIONI, L., Neuromuscular activity of Bothrops neuwiedi pauloensis snake venom in mouse nerve-muscle preparations (2005) J. Venom. Anim. Toxins incl. 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Purification and n-terminal sequencing of two presynaptic neurotoxic PLA2, neuwieditoxin-I and neuwieditoxin-II, from Bothrops neuwiedi pauloensis (jararaca pintada) venom

Two presynaptic phospholipases A2 (PLA2), neuwieditoxin-I (NeuTX-I) and neuwieditoxin-II (NeuTX-II), were isolated from the venom of Bothrops neuwiedi pauloensis (BNP). The venom was fractionated using molecular exclusion HPLC (Protein-Pak 300SW column), followed by reverse phase HPLC (µBondapak C18 column). Tricine-SDS-PAGE in the presence or absence of dithiothreitol showed that NeuTX-I and NeuTX-II had a molecular mass of approximately 14 kDa and 28kDa, respectively. At 10µg/ml, both toxins produced complete neuromuscular blockade in indirectly stimulated chick biventer cervicis isolated preparation without inhibiting the response to acetylcholine, but NeuTX-II reduced the response to KCl by 67.0&plusmn;8.0% (n=3; p<0.05). NeuTX-I and NeuTX-II are probably responsible for the presynaptic neurotoxicity of BNP venom in vitro. In fact, using loose patch clamp technique for mouse phrenic nerve-diaphragm preparation, NeuTX-I produced a calcium-dependent blockade of acetylcholine release and caused appearance of giant miniature end-plate potentials (mepps), indicating a pure presynaptic action. The N-terminal sequence of NeuTX-I was DLVQFGQMILKVAGRSLPKSYGAYGCYCGWGGRGK (71% homology with bothropstoxin-II and 54% homology with caudoxin) and that of NeuTX-II was SLFEFAKMILEETKRLPFPYYGAYGCYCGWGGQGQPKDAT (92% homology with Basp-III and 62% homology with crotoxin PLA2). The fact that NeuTX-I has Q-4 (Gln-4) and both toxins have F-5 (Phe-5) and Y-28 (Tyr-28) strongly suggests that NeuTX-I and NeuTX-II are Asp49 PLA2

Probabilistic fire spread forecast as a management tool in an operational setting

Background: An approach to predict fire growth in an operational setting, with the potential to be used as a decision-support tool for fire management, is described and evaluated. The operational use of fire behaviour models has mostly followed a deterministic approach, however, the uncertainty associated with model predictions needs to be quantified and included in wildfire planning and decision-making process during fire suppression activities. We use FARSITE to simulate the growth of a large wildfire. Probabilistic simulations of fire spread are performed, accounting for the uncertainty of some model inputs and parameters. Deterministic simulations were performed for comparison. We also assess the degree to which fire spread modelling and satellite active fire data can be combined, to forecast fire spread during large wildfires events. Results: Uncertainty was propagated through the FARSITE fire spread modelling system by randomly defining 100 different combinations of the independent input variables and parameters, and running the correspondent fire spread simulations in order to produce fire spread probability maps. Simulations were initialized with the reported ignition location and with satellite active fires. The probabilistic fire spread predictions show great potential to be used as a fire management tool in an operational setting, providing valuable information regarding the spatial–temporal distribution of burn probabilities. The advantage of probabilistic over deterministic simulations is clear when both are compared. Re-initializing simulations with satellite active fires did not improve simulations as expected. Conclusion: This information can be useful to anticipate the growth of wildfires through the landscape with an associated probability of occurrence. The additional information regarding when, where and with what probability the fire might be in the next few hours can ultimately help minimize the negative environmental, social and economic impacts of these firesinfo:eu-repo/semantics/publishedVersio

Granulocyte colony-stimulating factors for febrile neutropenia prophylaxis following chemotherapy: systematic review and meta-analysis

Background: Febrile neutropenia (FN) occurs following myelosuppressive chemotherapy and is associated with morbidity, mortality, costs, and chemotherapy reductions and delays. Granulocyte colony-stimulating factors (G-CSFs) stimulate neutrophil production and may reduce FN incidence when given prophylactically following chemotherapy. Methods: A systematic review and meta-analysis assessed the effectiveness of G-CSFs (pegfilgrastim, filgrastim or lenograstim) in reducing FN incidence in adults undergoing chemotherapy for solid tumours or lymphoma. G-CSFs were compared with no primary G-CSF prophylaxis and with one another. Nine databases were searched in December 2009. Meta-analysis used a random effects model due to heterogeneity. Results: Twenty studies compared primary G-CSF prophylaxis with no primary G-CSF prophylaxis: five studies of pegfilgrastim; ten of filgrastim; and five of lenograstim. All three G-CSFs significantly reduced FN incidence, with relative risks of 0.30 (95% CI: 0.14 to 0.65) for pegfilgrastim, 0.57 (95% CI: 0.48 to 0.69) for filgrastim, and 0.62 (95% CI: 0.44 to 0.88) for lenograstim. Overall, the relative risk of FN for any primary G-CSF prophylaxis versus no primary G-CSF prophylaxis was 0.51 (95% CI: 0.41 to 0.62). In terms of comparisons between different G-CSFs, five studies compared pegfilgrastim with filgrastim. FN incidence was significantly lower for pegfilgrastim than filgrastim, with a relative risk of 0.66 (95% CI: 0.44 to 0.98). Conclusions: Primary prophylaxis with G-CSFs significantly reduces FN incidence in adults undergoing chemotherapy for solid tumours or lymphoma. Pegfilgrastim reduces FN incidence to a significantly greater extent than filgrastim

Fever as a Cause of Hypophosphatemia in Patients with Malaria

Hypophosphatemia occurs in 40 to 60% of patients with acute malaria, and in many other conditions associated with elevations of body temperature. To determine the prevalence and causes of hypophosphatemia in patients with malaria, we retrospectively studied all adults diagnosed with acute malaria during a 12-year period. To validate our findings, we analyzed a second sample of malaria patients during a subsequent 10-year period. Serum phosphorus correlated inversely with temperature (n = 59, r = −0.62; P<0.0001), such that each 1°C increase in body temperature was associated with a reduction of 0.18 mmol/L (0.56 mg/dL) in the serum phosphorus level (95% confidence interval: −0.12 to −0.24 mmol/L [−0.37 to −0.74 mg/dL] per 1°C). A similar effect was observed among 19 patients who had repeat measurements of serum phosphorus and temperature. In a multiple linear regression analysis, the relation between temperature and serum phosphorus level was independent of blood pH, PCO2, and serum levels of potassium, bicarbonate, calcium, albumin, and glucose. Our study demonstrates a strong inverse linear relation between body temperature and serum phosphorus level that was not explained by other factors known to cause hypophosphatemia. If causal, this association can account for the high prevalence of hypophosphatemia, observed in our patients and in previous studies of patients with malaria. Because hypophosphatemia has been observed in other clinical conditions characterized by fever or hyperthermia, this relation may not be unique to malaria. Elevation of body temperature should be added to the list of causes of hypophosphatemia

Gene Ontology Consortium: going forward

The Gene Ontology (GO; http://www.geneontology.org) is a community-based bioinformatics resource that supplies information about gene product function using ontologies to represent biological knowledge. Here we describe improvements and expansions to several branches of the ontology, as well as updates that have allowed us to more efficiently disseminate the GO and capture feedback from the research community. The Gene Ontology Consortium (GOC) has expanded areas of the ontology such as cilia-related terms, cell-cycle terms and multicellular organism processes. We have also implemented new tools for generating ontology terms based on a set of logical rules making use of templates, and we have made efforts to increase our use of logical definitions. The GOC has a new and improved web site summarizing new developments and documentation, serving as a portal to GO data. Users can perform GO enrichment analysis, and search the GO for terms, annotations to gene products, and associated metadata across multiple species using the all-new AmiGO 2 browser. We encourage and welcome the input of the research community in all biological areas in our continued effort to improve the Gene Ontology