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Search Results: 1 - 10 of 201661 matches for " Wanderli P;Montenegro "
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Biological activity of neosergeolide and isobrucein B (and two semi-synthetic derivatives) isolated from the Amazonian medicinal plant Picrolemma sprucei (Simaroubaceae)
Silva, Ellen CC;Cavalcanti, Bruno C;Amorim, Rodrigo CN;Lucena, Jorcilene F;Quadros, Dulcimar S;Tadei, Wanderli P;Montenegro, Raquel C;Costa-Lotufo, Letícia V;Pessoa, Cláudia;Moraes, Manoel O;Nunomura, Rita CS;Nunomura, Sergio M;Melo, Marcia RS;Andrade-Neto, Valter F de;Silva, Luiz Francisco R;Vieira, Pedro Paulo R;Pohlit, Adrian M;
Memórias do Instituto Oswaldo Cruz , 2009, DOI: 10.1590/S0074-02762009000100008
Abstract: in the present study, in vitro techniques were used to investigate a range of biological activities of known natural quassinoids isobrucein b (1) and neosergeolide (2), known semi-synthetic derivative 1,12-diacetylisobrucein b (3), and a new semi-synthetic derivative, 12-acetylneosergeolide (4). these compounds were evaluated for general toxicity toward the brine shrimp species artemia franciscana, cytotoxicity toward human tumour cells, larvicidal activity toward the dengue fever mosquito vector aedes aegypti, haemolytic activity in mouse erythrocytes and antimalarial activity against the human malaria parasite plasmodium falciparum. compounds 1 and 2 exhibited the greatest cytotoxicity against all the tumor cells tested (ic50 = 5-27 μg/l) and against multidrug-resistant p. falciparum k1 strain (ic50 = 1.0-4.0 g/l) and 3 was only cytotoxic toward the leukaemia hl-60 strain (ic50 = 11.8 μg/l). quassinoids 1 and 2 (lc50 = 3.2-4.4 mg/l) displayed greater lethality than derivative 4 (lc50 = 75.0 mg/l) toward a. aegypti larvae, while derivative 3 was inactive. these results suggest a novel application for these natural quassinoids as larvicides. the toxicity toward a. franciscana could be correlated with the activity in several biological models, a finding that is in agreement with the literature. importantly, none of the studied compounds exhibited in vitro haemolytic activity, suggesting specificity of the observed cytotoxic effects. this study reveals the biological potential of quassinoids 1 and 2 and to a lesser extent their semi-synthetic derivatives for their in vitro antimalarial and cytotoxic activities.
Occurrence of apocrine secretion in the larval gut epithelial cells of Aedes aegypti L., Anopheles albitarsis Lynch-Arribálzaga and Culex quinquefasciatus say (Diptera: Culicidae): a defense strategy against infection by Bacillus sphaericus Neide?
Oliveira, Caroline D;Tadei, Wanderli P;Abdalla, Fábio C;
Neotropical Entomology , 2009, DOI: 10.1590/S1519-566X2009000500010
Abstract: cell hypertrophy was the first reaction of the gut epithelial cells of aedes aegypti (l.), anopheles albitarsis (lynch-arribálzaga) and culex quinquefasciatus (say) to the toxins of strains 2362 and s1116 of bacillus sphaericus, as cells had an increase of intracellular secretory activity. soon after the cell hypertrophy developed, vesicles were formed at the cell apical portion, which detached with the plasma membrane, characterizing a type of apocrine secretion like. the first pathway of contamination of the mosquito larvae by these bacteria is through the gut, by feeding. depending on the species of culicidae and on the bacterial strain used, the hypertrophy of the gut epithelium occurred between 5 and 15 min after exposure to the contaminated environment. the second aspect observed after hypertrophy was the increase in apocrine secretion. the basophilic vesicles that detached from the cells remained between the peritrophic membrane and the gut lumen, such vesicles were filled with material of unknown nature. the gut posterior region showed secretory activity in both control and treated larvae, being much more intense in bacteria-exposed larvae. there were remarkable differences in the epithelial cell reaction according to the toxins of the two bacterial strains, but c.quinquefasciatus was the most susceptible. differences in the gut cell reactions to the toxins produced by the two bacterial strains are discussed.
THE CONTROL OF ANOPHELINE MOSQUITOS BY THE SPRAYING OF DELTAMETHRIN ON RAFFIA CURTAINS USED IN MINERS' HUTS IN AREAS ENDEMIC FOR MALARIA
FIGUEIREDO, Regina;TADEI, Wanderli P.;THATCHER, Bedsy Dutary;
Revista do Instituto de Medicina Tropical de S?o Paulo , 1998, DOI: 10.1590/S0036-46651998000200008
Abstract: the residual potential of an aqueous solution of deltamethrin (fw 25 mg i.a./m2) was evaluated on raffia curtains. these are sheets of synthetic material used in the construction of huts to house miners. experiments were conducted during 420 days and the curtains were always rolled up in the daytime and unrolled in late afternoon. data analyzed by logarithmic regression indicated that raffia treated with deltamethrin had higher mortality indices than that covered with ddt. the residual capacity of deltamethrin on raffia was high. the mortality percentage was above 85% after 360 days and dropped to about 50% at 420 days. the effect of ddt was reduced after 180 days and reached zero by the end of the experiment. based on the results of these experiments, it is recommended that deltamethrin be used to spray raffia curtains in mining regions and other areas that are endemic for malaria.
THE CONTROL OF ANOPHELINE MOSQUITOS BY THE SPRAYING OF DELTAMETHRIN ON RAFFIA CURTAINS USED IN MINERS' HUTS IN AREAS ENDEMIC FOR MALARIA
FIGUEIREDO Regina,TADEI Wanderli P.,THATCHER Bedsy Dutary
Revista do Instituto de Medicina Tropical de S?o Paulo , 1998,
Abstract: The residual potential of an aqueous solution of Deltamethrin (FW 25 mg i.a./m2) was evaluated on raffia curtains. These are sheets of synthetic material used in the construction of huts to house miners. Experiments were conducted during 420 days and the curtains were always rolled up in the daytime and unrolled in late afternoon. Data analyzed by logarithmic regression indicated that raffia treated with Deltamethrin had higher mortality indices than that covered with DDT. The residual capacity of Deltamethrin on raffia was high. The mortality percentage was above 85% after 360 days and dropped to about 50% at 420 days. The effect of DDT was reduced after 180 days and reached zero by the end of the experiment. Based on the results of these experiments, it is recommended that Deltamethrin be used to spray raffia curtains in mining regions and other areas that are endemic for malaria.
Intrapopulational genetic differentiation in Anopheles (N.) darlingi Root, 1926 (Diptera: Culicidae) in the amazon region
Santos, Joselita Maria Mendes dos;Lobo, Jorge Arturo;Tadei, Wanderli Pedro;Contel, Eucleia P. Betioli;
Genetics and Molecular Biology , 1999, DOI: 10.1590/S1415-47571999000300007
Abstract: four natural amazonian anopheles darlingi populations were analyzed for 19 loci, 12 of which showed variation, i.e., 68.4% of polymorphic loci. the ariquemes, rond?nia, population was the most variable, with a large number of alleles per locus (2.26 ± 0.27) and high polymorphism (p = 63.15). the highest values of observed and expected intralocus heterozygosity were observed in the manaus, amazonas, population (ho = 0.432 ± 0.11; he = 0.375 ± 0.08), and the lowest in the cachoeira porteira, pará, population (ho = 0.236 ± 0.09; he = 0.290 ± 0.11). wright's f-statistic revealed disequilibrium caused by an excess of homozygotes, as shown by the fis > fst values (fis = 0.083 > 0.026) reflecting intrapopulational differentiation. the four populations studied were genetically similar, as indicated by distance and similarity values. chromosomal variation of amazon population also did not indicate geographical differentiation, and populations in the central region of the amazon basin showed high polymorphism in relation to the marginal populations, which were mainly monomorphic.
Intrapopulational genetic differentiation in Anopheles (N.) darlingi Root, 1926 (Diptera: Culicidae) in the amazon region
Santos Joselita Maria Mendes dos,Lobo Jorge Arturo,Tadei Wanderli Pedro,Contel Eucleia P. Betioli
Genetics and Molecular Biology , 1999,
Abstract: Four natural Amazonian Anopheles darlingi populations were analyzed for 19 loci, 12 of which showed variation, i.e., 68.4% of polymorphic loci. The Ariquemes, Rond nia, population was the most variable, with a large number of alleles per locus (2.26 ± 0.27) and high polymorphism (P = 63.15). The highest values of observed and expected intralocus heterozygosity were observed in the Manaus, Amazonas, population (Ho = 0.432 ± 0.11; He = 0.375 ± 0.08), and the lowest in the Cachoeira Porteira, Pará, population (Ho = 0.236 ± 0.09; He = 0.290 ± 0.11). Wright's F-statistic revealed disequilibrium caused by an excess of homozygotes, as shown by the Fis > Fst values (Fis = 0.083 > 0.026) reflecting intrapopulational differentiation. The four populations studied were genetically similar, as indicated by distance and similarity values. Chromosomal variation of Amazon population also did not indicate geographical differentiation, and populations in the central region of the Amazon Basin showed high polymorphism in relation to the marginal populations, which were mainly monomorphic.
Modelo dietético de los universitarios Dietary model of college students
P. Bollat Montenegro,T. Durá Travé
Nutrición Hospitalaria , 2008,
Abstract:
Dynamics of the diluted Ising antiferromagnet Fe0.31Zn0.69F2
K. Jonason,P. Nordblad,F. C. Montenegro
Physics , 1999,
Abstract: The diluted Ising antiferromagnet, Fe_{0.31}Zn_{0.69}F_{2}, has been investigated by dynamic susceptibility measurements in zero and and finite applied dc-fields. In zero field, there is a para- to antiferromagnetic phase transition at $T_{N} \approx {20.0 K}$, followed by a dramatic slowing down of the dynamics at low temperatures. The latter described by a pure Arrhenius law. The effect of a superposed dc-field on the antiferromagnetic phase transition and on the low-temperature dynamics is investigated, and a comprehensive static and dynamic phase diagram in the H-T plane is derived. In agreement with earlier results on the same system, $T_{N}(H)$ follows a random-exchange Ising model to random-field Ising model crossover scaling for fields $H \leq 1.5 T$. A random-field induced glassy dynamics appears for higher values of H, where the antiferromagnetic phase transition is destroyed. The low-temperature dynamics shows striking similarities with the behavior observed in reentrant antiferromagnets.
Complete mtDNA genomes of Anopheles darlingi and an approach to anopheline divergence time
Marta Moreno, Osvaldo Marinotti, Jaroslaw Krzywinski, Wanderli P Tadei, Anthony A James, Nicole L Achee, Jan E Conn
Malaria Journal , 2010, DOI: 10.1186/1475-2875-9-127
Abstract: The mtDNAs were sequenced from mosquitoes from Belize and Brazil and comparative analyses of structure and base composition, among others, were performed. A maximum likelihood approach linked with phylogenetic information was employed to detect evidence of selection and a Bayesian approach was used to date the split between the subgenus Nyssorhynchus and other Anopheles subgenera.The comparison of mtDNA sequences within the Anopheles darlingi taxon does not provide sufficient resolution to establish different units of speciation within the species. In addition, no evidence of positive selection in any protein-coding gene of the mtDNA was detected, and purifying selection likely is the basis for this lack of diversity. Bayesian analysis supports the conclusion that the most recent ancestor of Nyssorhynchus and Anopheles+Cellia was extant ~94 million years ago.Analyses of mtDNA genomes of Anopheles darlingi do not provide support for speciation in the taxon. The dates estimated for divergence among the anopheline groups tested is in agreement with the geological split of western Gondwana (95 mya), and provides additional support for explaining the absence of Cellia in the New World, and Nyssorhynchus in the Afro-Eurasian continents.Anopheles darlingi is a major malaria vector in the Americas [1]. Its broad geographical distribution, ranging from southern Mexico to northern Argentina, is coupled with a high morphological, behavioral and genetic diversity [2-8]. Support for considerable genetic variation within this taxon comes from the analysis of polytene chromosomes [6], isozymes [7], as well as nuclear and mitochondrial DNA markers [8-14].Analysis of the An. darlingi population structure based on the cytochrome-oxidase subunit 1 mitochondrial gene (COI) provided evidence in support of two significant subdivisions among An. darlingi populations from Central (including northwestern Colombia) and South America, with FST values similar to those found among different spe
Detection of dengue virus serotype 3 by reverse transcription-polymerase chain reaction in Aedes aegypti (Diptera, Culicidae) captured in Manaus, Amazonas
Pinheiro, Valéria CS;Tadei, Wanderli P;Barros, Patrícia MSS;Vasconcelos, Pedro FC;Cruz, Ana Cecília R;
Memórias do Instituto Oswaldo Cruz , 2005, DOI: 10.1590/S0074-02762005000800003
Abstract: the detection of dengue virus serotypes from aedes aegypti in manaus, state of amazonas was carried out using the reverse transcription-polymerase chain reaction technique. fourteen pools out 82 (17.1%) were positive for denv3, providing a minimal infection rate of 2.1% of all analyzed infected female specimens of three different areas of the city.
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