Diversidade de fungos associados a Parlatoria ziziphus (Lucas)(Hemiptera: Diaspididae) em Citros

As espécies de entomopatógenos que causam impacto em populações de hospedeiros são muitas. Entretanto, informações básicas sobre sua biologia, identificação e relação entre o sistema patógeno-hospedeiro são escassas. Este estudo teve por objetivo identificar os fungos associados a Parlatoria ziziphus (Lucas)em pomares citrícolas do município de Taiúva, SP. Foram realizadas coletas mensais, em dois pomares de laranja (Citrus sinensis Osbeck), variedade Pera, de janeiro de 1995 a fevereiro de 1996. Amostraram-se 15 árvores em cada pomar, retirando-se 16 folhas por árvore. Estas foram levadas ao laboratório, para determinação dos fungos associados à cochonilha. Para a identificação dos fungos, consideraram-se aspectos da estrutura reprodutiva e do esporo. Foram identificadas cinco espécies, citadas como patógenos de diaspidídeos por vários autores: Fusarium coccophilum (Desm.) Wr. & Rg., Nectria flammea (Tul.) Dingley (fase sexual de F. coccophilum), Tetracrium coccicolum Hohnell, Podonectria coccicola (Ellis & Everhart) Petch (fase sexual de T. coccicolum) e Myriangium duriaei Mont. & Berk. Fusarium coccophilum foi a espécie mais freqüente e a mais prevalente, na maioria das coletas realizadas, em ambas as áreas amostradas.

A refinement of the gauss-lucas theorem

The classical Gauss-Lucas Theorem states that all the critical points (zeros of the derivative) of a nonconstant polynomial p lie in the convex hull H of the zeros of p. It is proved that, actually, a subdomain of H contains the critical points of p. ©1998 American Mathematical Society.

Orphan nuclear receptor NGFI-B forms dimers with nonclassical interface

The orphan receptor nerve growth factor-induced B (NGFI-B) is a member of the nuclear receptor's subfamily 4A (Nr4a). NGFI-B was shown to be capable of binding both as a monomer to an extended half-site containing a single AAAGGTCA motif and also as a homodimer to a widely separated everted repeat, as opposed to a large number of nuclear receptors that recognize and bind specific DNA sequences predominantly as homo- and/or heterodimers. To unveil the structural organization of NGFI-B in solution, we determined the quaternary structure of the NGFI-B LBD by a combination of ab initio procedures from small-angle X-ray scattering (SAXS) data and hydrogen-deuterium exchange followed by mass spectrometry. Here we report that the protein forms dimers in solution with a radius of gyration of 2.9 nm and maximum dimension of 9.0 nm. We also show that the NGFI-B LBD dimer is V-shaped, with the opening angle significantly larger than that of classical dimer's exemplified by estrogen receptor (ER) or retinoid X receptor (RXR). Surprisingly, NGFI-B dimers formation does not occur via the classical nuclear receptor dimerization interface exemplified by ER and RXR, but instead, involves an extended surface area composed of the loop between helices 3 and 4 and C-terminal fraction of the helix 3. Remarkably, the NGFI-B dimer interface is similar to the dimerization interface earlier revealed for glucocorticoid nuclear receptor (GR), which might be relevant to the recognition of cognate DNA response elements by NGFI-B and to antagonism of NGFI-B-dependent transcription exercised by GR in cells. Published by Cold Spring Harbor Laboratory Press. Copyright © 2007 The Protein Society.

New ruthenium(II)/phosphines/diimines complexes: Promising antitumor (human breast cancer) and Mycobacterium tuberculosis fighting agents

The synthesis and characterization of ruthenium compounds of the type [RuCl2(P)2(N-N)] [(P)2 = (PPh3) 2, dppb = 1,4-bis(diphenylphosphino)butano; dppp = 1,3-bis(diphenylphosphino)propane; N-N = 5,5′-dimethyl-2,2′dipyridyl (5,5′-mebipy) or 4,4′-dimethyl-2,2′dipyridyl (4,4′-mebipy)] are described. The complexes were characterized using elemental analysis, UV-Vis and infrared spectroscopies, cyclic voltammetry, and X-ray crystallography. In vitro evaluation of the complexes, using the MTT methodology, revealed their cytotoxic activities in a range of 5.4-15.7 μM against the MDA-MB-231 breast tumor cells and showed that, in this case, they are more active than the reference metallodrug cisplatin. The in vitro antimycobacterial activities of the complexes had their Minimum Inhibitory Concentration (MIC) for MTB cell growth measured, by the REMA method. The MICs for these complexes were found to be between 12.5 and 25.0 μg/mL. The results are comparable with the second line drug cycloserine (MIC = 12.5-50.0 μg/mL), commonly used in the treatment of TB. © 2013 Elsevier Ltd. All rights reserved.

Detecção das proteínas p53, p63 e puma no carcinoma de células escamosas corneal de cães: Lucas Bahdour Cossi. -

Pós-graduação em Ciência Animal - FMVA

Ruthenium(II) complexes with hydroxypyridinecarboxylates: screening potential metallodrugs against Mycobacterium tuberculosis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)