82 research outputs found
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. Trop. Dis, 11, pp. 22-33FONTES, M.R., SOARES, A.M., RODRIGUES, V.M., FERNANDES, A.C., DA SILVA, R.J., GIGLIO, J.R., Crystallization and preliminary X-ray diffraction analysis of a myotoxic phospholipase A(2) homologue from Bothrops neuwiedi pauloensis venom (1999) Biochim. Biophys. Acta, 1432, pp. 393-395FRANCIS, B., GUTIERREZ, J.M., LOMONTE, B., KAISER II, Myotoxin II from Bothrops asper (Terciopelo) venom is a lysine-49 phospholipase A 2 (1991) Arch. Biochem. Biophys, 284, pp. 352-359GEOGHEGAN, P., ANGULO, Y., CANGELOSI, A., DIAZ, M., LOMONTE, B., Characterization of a basic phospholipase A2-homologue myotoxin isolated from the venom of the snake Bothrops neuwiedii (yarara chica) from Argentina (1999) Toxicon, 37, pp. 1735-1746GINSBORG, B.L., WARRINER, J., The isolated chick biventer cervicis nerve-muscle preparation (1960) Brit. J. Pharmacol, 15, pp. 410-411HALPERT, J., EAKER, D., Amino acid sequence of a presynaptic neurotoxin from the venom of Notechis scutatus scutatus (Australian tiger snake) (1975) J. Biol. Chem, 250, pp. 6990-6997HARVEY AL., BARFARAZ A., THOMPSON E., FAIZ A., PRESTON S., HARRIS JB. Screening of snake venoms for neurotoxic and myotoxic effects using simple in vitro preparations from rodents and chicks. Toxicon, 1994, 32, 257-65HELUANY, N.F., HOMSI-BRANDEBURGO, M.I., GIGLIO, J.R., PRADO-FRANCESCHI, J., RODRIGUES-SIMIONI, L., Effects induced by bothropstoxin, a component from Bothrops jararacussu snake venom, on mouse and chick muscle preparations (1992) Toxicon, 30, pp. 1203-1210HOLZER, M., MACKESSY, S.P., An aqueous endpoint assay of snake venom phospholipase A2 (1995) Toxicon, 35, pp. 1149-1155HOMSI-BRANDEBURGO, M.I., QUEIROZ, L.S., SANTO-NETO, H., RODRIGUES-SIMIONI, L., GIGLIO, J.R., Fractionation of Bothrops jararacussu snake venom: Partial chemical characterization and biological activity of bothropstoxin (1988) Toxicon, 26, pp. 615-627JOHNSON, E.K., OWNBY, C.L., Isolation of a myotoxin from the venom of Agkistrodon contortrix laticinctus (broad-banded copperhead) and pathogenesis of myonecrosis induced by it in mice (1993) Toxicon, 31, pp. 243-255KAISER II, Gutierrez, J.M., Plummer, D., Aird, S.D., Odell, G.V., AIRD SD., ODELL GV. The amino acid sequence of a myotoxic phospholipase from the venom of Bothrops asper (1990) Arch. Biochem. Biophys, 278, pp. 319-325KATZ, B., MILEDI, R., The binding of acetylcholine to receptors and its removal from the synaptic cleft (1973) J. Physiol, 231, pp. 549-574KINI RM. Phospholipase A2 - A complex multifunctional protein puzzle. In: KINI RM. Ed., Venom phosholipase A2 enzymes. Structure, function and mechanism. New York: John Wiley &Sons Inc Chichester, 1997, 1-28KONDO, K., NARITA, K., LEE, C.Y., Amino acid sequences of the two polypeptide chains in beta1-bungarotoxin from the venom of Bungarus multicinctus (1978) J. Biochem, 83, pp. 101-115KONDO, K., TODA, H., NARITA, K., LEE, C.Y., Amino acid sequence of β2-bungarotoxin from Bungarus multicinctus venom: The amino acid substitutions in the B chains (1982) J. Biochem, 91, pp. 1519-1530KONDO, K., ZHANG, J., XU, K., KAGAMIYAMA, H., Amino acid sequence of a presynaptic neurotoxin, agkistrodotoxin, from the venom of Agkistrodon halys pallas (1989) J. Biochem, 105, pp. 196-203KORDAS, M., On the role of junctional cholinesterase in determining the time course of the end-plate current (1977) J. Physiol, 270, pp. 133-150LEE, C.Y., HO, C.L., BOTES, D.P., Site of action of caudoxin, a neurotoxic phospholipase A2 from the horned puff adder (Bitis caudalis) venom (1982) Toxicon, 20, pp. 637-647LIND, P., EAKER, D., Amino-acid sequence of the alpha-subunit of taipoxin, an extremely potent presynaptic neurotoxin from the Australian snake taipan (Oxyuranus s. scutellatus) (1982) European J. Biochem, 124, pp. 441-447MAGRO, A.J., SOARES, A.M., GIGLIO, J.R., FONTES, M.R., Crystal structures of BnSP-7 and BnSP-6, two Lys49 phospholipases A2: Quartenary structure and inhibition mechanism insights (2003) Biochem. Biophys. Res. Commun, 311, pp. 713-720MONTECUCCO, C., ROSSETTO, O., How do presynaptic PLA2 neurotoxins block nerve terminals? (2000) Trends Biochem. Sciences, 25, pp. 266-270OSHIMA-FRANCO, Y., HYSLOP, S., CINTRA, A.C., GIGLIO, J.R., DA CRUZ-HOFLING, M.A., RODRIGUES-SIMIONI, L., Neutralizing capacity of commercial bothropic antivenom against Bothrops jararacussu venom and bothropstoxin-I (2000) Muscle Nerve, 23, pp. 1832-1839OSHIMA-FRANCO, Y., LEITE, G.B., SILVA, G.H., CARDOSO, D.F., HYSLOP, S., GIGLIO, J.R., DA CRUZ-HOFLING, M.A., RODRIGUES-SIMIONI, L., Neutralization of the pharmacological effects of bothropstoxin-I from Bothrops jararacussu (jararacuçu) venom by crotoxin antiserum and heparin (2001) Toxicon, 39, pp. 1477-1485PEREIRA, M.F., NOVELLO, J.C., CINTRA, A.C., GIGLIO, J.R., LANDUCCI, E.T., OLIVEIRA, B., MARANGONI, S., The amino acid sequence of bothropstoxin-II, an Asp-49 myotoxin from Bothrops jararacussu (jararacuçu) venom with low phospholipase A2 activity (1998) J. Protein Chem, 17, pp. 381-386RE, L., BAROCCI, S., CAPITANI, C., VIVANI, C., RICCI, M., RINALDI, L., PAOLUCCI, G., MORALES, M.A., Effects of some natural extracts on the acetylcholine release at the mouse neuromuscular junction (1999) Pharmacol. Res, 39, pp. 239-245RE, L., COLA, V., FULGENZI, G., MARINELLI, F., CONCETTONI, C., ROSSINI, L., Postsynaptic effects of methoctramine at the mouse neuromuscular junction (1993) Neuroscience, 57, pp. 451-457RE, L., GIUSTI, P., CONCETTONI, C., DI SARRA, B., Computerized estimation of spontaneous and evoked acetylcholine release at the neuromuscular junction (1989) J. Pharmacol. Meth, 22, pp. 233-242RE, L., MORETTI, V., ROSSINI, L., GIUSTI, P., Sodium-activated potassium current in mouse diaphragm (1990) FEBS Lett, 270, pp. 195-197RIBEIRO, L.A., ALBUQUERQUE, M.J., PIRES DE CAMPOS VAF., KATZ G., TAKAOKAM NY., LEBRÃO ML., JORGE MT. Óbitos por serpentes peçonhentas no Estado de São Paulo: Avaliação de 43 casos, 1988/98 (1998) Rev. Assoc. Méd. Bras, 44, pp. 312-318RITONJA A., GUBENSEK F. Ammodytoxin A, a highly lethal phospholipase A2 from Vipera ammodytes ammodytes venom. Biochim. Biophys. Acta, 1985, 828, 306-12RODRIGUES-SIMIONI, L., BORGESE, N., CECCARELLI, B., The effects of Bothrops jararacussu venom and its components on frog nerve-muscle preparation (1983) Neuroscience, 10, pp. 475-489RODRIGUES-SIMIONI, L., ZAMUNER, S.R., COGO, J.C., BORJA-OLIVEIRA, C.R., PRADO-FRANCESCHI, J., CRUZ-HOFLING, M.A., CORRADO, A.P., Pharmacological evidence for a presynaptic action of venoms from Bothrops insularis (jararaca ilhoa) and Bothrops neuwiedi (jararaca pintada) (2004) Toxicon, 43, pp. 633-638SCHAGGER, H., VON JAGOW, G., Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis for the separation of proteins in the range from 1 to 100kDa (1987) Anal. Biochem, 166, pp. 368-379SOARES, A.M., GUERRA-SÁ, R., BORJA-OLIVEIRA, C.R., RODRIGUES, V.M., RODRIGUES-SIMIONI, L., RODRIGUES, V., FONTES, M.R.M., GIGLIO, J.R., Structural and functional characterization of BnSP-7, a Lys49 myotoxic phospholipase A2 homologue from Bothrops neuwiedi venom (2000) Arch. Biochem. Biophys, 378, pp. 201-209STÜHMER, W., ROBERTS, W.M., ALMERS, W., The loose patch clamp (1983) Single Channel Recording, p. 123. , SAKMANN B AND NEHER E, Eds, Plenum Press, New York;TOYAMA, M.H., SOARES, A.M., WEN-HWA, L., POLIKARPOV, I., GIGLIO, J.R., MARANGONI, S., Amino acid sequence of piratoxin-II, a myotoxic lys49 phospholipase A 2 homologue from Bothrops pirajai venom (2000) Biochimie, 82, pp. 245-250TSAI, I.H., LU, P.J., WANG, Y.M., HO, C.L., LIAW, L.L., Molecular cloning and characterization of a neurotoxic phospholipase A2 from the venom of Taiwan habu (Trimeresurus mucrosquamatus) (1995) Biochem. J, 311, pp. 895-900VAN DEN BERGH, C.J., SLOTBOOM, A.J., VERHEIJ, H.M., DE HAAS, G.H., The role of aspartic acid-49 in the active site of phospholipase A2. A site-specific mutagenesis study of porcine pancreatic phospholipase A 2 and the rationale of the enzymatic activity of Lys-49 phospholipase A2 from Agkistrodon piscivorus piscivorus venom (1988) European J. Biochem, 176, pp. 353-357VAN DEENEN LL, D.H.G., The substrate specificity of phospholipases A2 (1963) Biochim. Biophys. Acta, 70, pp. 538-553VILJOEN, C.C., BOTES, D.P., KRUGER, H., Isolation and amino acid sequence of caudoxin, a presynaptic acting toxic phospholipase A2 from the venom of the horned puff adder (Bitis caudalis) (1982) Toxicon, 20, pp. 715-737ZAMUNER, S.R., PRADO-FRANCESCHI, J., RODRIGUES-SIMIONI, L., The screening of Bothrops venoms for neurotoxic activity using the chick biventer cervicis preparation (1996) Toxicon, 34, pp. 314-31
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
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
Brazilian Medical Association guidelines for the diagnosis and differential diagnosis of panic disorder
A global approach to the management of EMR (Electronic Medical Records) of patients with HIV/AIDS in Sub-Saharan Africa: the experience of DREAM Software
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
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