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91.
Moreira JS Almeida RG Tavares LS Santos MO Viccini LF Vasconcelos IM Oliveira JT Raposo NR Dias SC Franco OL 《The protein journal》2011,30(1):32-38
Heavy agricultural losses are closely related to attacks by insect-pests and phytopathogens such as bacteria and fungi. Among
them, the fungus Botrytis cinerea can cause gray mold in more than 200 different species of plants, and is considered a challenging problem for agribusiness.
Fungicides are commonly used to control this pathogen because they are fast-working and easy to apply. However, the continuous
use of fungicides may promote the selection of resistant fungi and can also cause profound contamination in ecosystems. Aiming
to find alternative strategies to solve these problems, several studies have focused on searching for plant proteins and peptides
with antifungal activities (AFPs). With this in mind, this report shows the isolation and characterization of two novels antifungal
proteins from flowers of rosemary pepper (Lippia sidoides Cham.) with 10 and 15 kDa. Isolation was performed by using an Octyl-Sepharose hydrophobic column. In vitro bioassays indicated
that isolated proteins were able to inhibit B. cinerea development, but were not effective against all bacteria tested. Moreover, N-termini sequences indicate that both proteins
showed sequence homology with NBS–LRR R proteins with a lower molecular mass, suggesting possible protein fragmentation. Data
reported here could help in the development of biotechnological products for crop protection against phytopathogenic fungi
in the near future. 相似文献
92.
Vera Teixeira Natacha Arede Rui Gardner Joaquín Rodríguez-León Ana T Tavares 《BMC developmental biology》2011,11(1):1-7
Background
Hemangioblasts are known as the common precursors for primitive hematopoietic and endothelial lineages. Their existence has been supported mainly by the observation that both cell types develop in close proximity and by in vitro differentiation and genetic studies. However, more compelling evidence will arise from tracking their cell fates using a lineage-specific marker.Results
We report the identification of a hemangioblast-specific enhancer (Hb) located in the cis-regulatory region of chick Cerberus gene (cCer) that is able to direct the expression of enhanced green fluorescent protein (eGFP) to the precursors of yolk sac blood and endothelial cells in electroporated chick embryos. Moreover, we present the Hb-eGFP reporter as a powerful live imaging tool for visualizing hemangioblast cell fate and blood island morphogenesis.Conclusions
We hereby introduce the Hb enhancer as a valuable resource for genetically targeting the hemangioblast population as well as for studying the dynamics of vascular and blood cell development. 相似文献93.
94.
Thirant C Bessette B Varlet P Puget S Cadusseau J Tavares Sdos R Studler JM Silvestre DC Susini A Villa C Miquel C Bogeas A Surena AL Dias-Morais A Léonard N Pflumio F Bièche I Boussin FD Sainte-Rose C Grill J Daumas-Duport C Chneiweiss H Junier MP 《PloS one》2011,6(1):e16375
Background
Primitive brain tumors are the leading cause of cancer-related death in children. Tumor cells with stem-like properties (TSCs), thought to account for tumorigenesis and therapeutic resistance, have been isolated from high-grade gliomas in adults. Whether TSCs are a common component of pediatric brain tumors and are of clinical relevance remains to be determined.Methodology/Principal Findings
Tumor cells with self-renewal properties were isolated with cell biology techniques from a majority of 55 pediatric brain tumors samples, regardless of their histopathologies and grades of malignancy (57% of embryonal tumors, 57% of low-grade gliomas and neuro-glial tumors, 70% of ependymomas, 91% of high-grade gliomas). Most high-grade glioma-derived oncospheres (10/12) sustained long-term self-renewal akin to neural stem cells (>7 self-renewals), whereas cells with limited renewing abilities akin to neural progenitors dominated in all other tumors. Regardless of tumor entities, the young age group was associated with self-renewal properties akin to neural stem cells (P = 0.05, chi-square test). Survival analysis of the cohort showed an association between isolation of cells with long-term self-renewal abilities and a higher patient mortality rate (P = 0.013, log-rank test). Sampling of low- and high-grade glioma cultures showed that self-renewing cells forming oncospheres shared a molecular profile comprising embryonic and neural stem cell markers. Further characterization performed on subsets of high-grade gliomas and one low-grade glioma culture showed combination of this profile with mesenchymal markers, the radio-chemoresistance of the cells and the formation of aggressive tumors after intracerebral grafting.Conclusions/Significance
In brain tumors affecting adult patients, TSCs have been isolated only from high-grade gliomas. In contrast, our data show that tumor cells with stem cell-like or progenitor-like properties can be isolated from a wide range of histological sub-types and grades of pediatric brain tumors. They suggest that cellular mechanisms fueling tumor development differ between adult and pediatric brain tumors. 相似文献95.
Martins RH Gonçalves TM Neves DS Fracalossi TA Tavares EL Moretti-Ferreira D 《Genetics and molecular research : GMR》2011,10(4):3163-3168
We found evidence of autosomal dominant hereditary transmission of sulcus vocalis. Four dysphonic patients from three generations of the same family were submitted to videolaryngoscopic examination (three patients) and to direct laryngoscopy (one patient) to diagnose the hoarseness. Sulcus vocalis was diagnosed in all four patients. The finding of four affected individuals in three generations, with vertical transmission affecting man and women, is more consistent with autosomal dominant inheritance pattern; it is an etiological model that we propose for the sulcus vocalis in this pedigree. 相似文献
96.
Fernanda Vieira da Costa Frederico de Siqueira Neves Jhonathan de Oliveira Silva Marc��lio Fagundes 《Arthropod-Plant Interactions》2011,5(1):9-18
Plant development is the main factor that determines the insect-ontogeny interaction, since it leads to variations in resource
quality and availability. The aim of this study was to test the hypothesis that plant development and varying tannin concentration
leads to changes in species richness, abundance and composition of ants, free-feeding herbivores and galling insects associated
with Copaifera langsdorffii (Fabaceae). The plant ontogeny and tannin concentration effects on insects were tested on 60 individuals with height varying from 0.9
to 11.0 m. A positive correlation was observed for tree height and species richness and abundance of ants, free-feeding and
galling insects. In contrast, we did not find a significant relation between leaf tannin concentration and plant height, or
richness and abundance of the different insect guilds. The assemblage of ants (composition of species) did not change between
saplings and adults of C. langsdorffii. However, the assemblage of free-feeding herbivores and galling insects varied between the two development stages studied.
The present study reveals an ontogenetic succession pattern for herbivore insects along the C. langsdorffii growth, probably due to both indirect and direct benefits from the host plant architecture and quality. Those plants with
more complex architectures should support a wider diversity of insects, since they present higher number of sites for egg
laying, housing, feeding and better environmental conditions. This is the first work to investigate the host plant ontogeny
effect on insects in Cerrado “Savanna” vegetation. The pattern described, along with other previous studies, suggests a vast
occurrence of ontogenetic succession in tropical areas. 相似文献
97.
Cassado Ados A de Albuquerque JA Sardinha LR Buzzo Cde L Faustino L Nascimento R Ghosn EE Lima MR Alvarez JM Bortoluci KR 《PloS one》2011,6(7):e22141
The peritoneal cavity (PerC) is a singular compartment where many cell populations reside and interact. Despite the widely adopted experimental approach of intraperitoneal (i.p.) inoculation, little is known about the behavior of the different cell populations within the PerC. To evaluate the dynamics of peritoneal macrophage (MØ) subsets, namely small peritoneal MØ (SPM) and large peritoneal MØ (LPM), in response to infectious stimuli, C57BL/6 mice were injected i.p. with zymosan or Trypanosoma cruzi. These conditions resulted in the marked modification of the PerC myelo-monocytic compartment characterized by the disappearance of LPM and the accumulation of SPM and monocytes. In parallel, adherent cells isolated from stimulated PerC displayed reduced staining for β-galactosidase, a biomarker for senescence. Further, the adherent cells showed increased nitric oxide (NO) and higher frequency of IL-12-producing cells in response to subsequent LPS and IFN-γ stimulation. Among myelo-monocytic cells, SPM rather than LPM or monocytes, appear to be the central effectors of the activated PerC; they display higher phagocytic activity and are the main source of IL-12. Thus, our data provide a first demonstration of the consequences of the dynamics between peritoneal MØ subpopulations by showing that substitution of LPM by a robust SPM and monocytes in response to infectious stimuli greatly improves PerC effector activity. 相似文献
98.
Boström M Tavares FW Finet S Skouri-Panet F Tardieu A Ninham BW 《Biophysical chemistry》2005,117(3):217-224
The relative effectiveness of different anions in crystallizing proteins follows a reversed Hofmeister sequence for pHpI. The phenomenon has been known almost since Hofmeister's original work but it has not been understood. It is here given a theoretical explanation. Classical electrolyte and double layer theory deals only with electrostatic forces acting between ions and proteins. Hydration and hydration interactions are dealt with usually only in terms of assumed hard core models. But there are, at and above biological salt concentrations, other non-electrostatic (NES) ion-specific forces acting that are ignored in such modeling. Such electrodynamic fluctuation forces are also responsible for ion-specific hydration. These missing forces are variously comprehended under familiar but generally unquantified terms, typically, hydration, hydrogen bonding, pi-electron-cation interactions, dipole-dipole, dipole-induced dipole and induced dipole-induced dipole forces and so on. The many important body electrodynamic fluctuation force contributions are accessible from extensions of Lifshitz theory from which, with relevant dielectric susceptibility data on solutions as a function of frequency, the forces can be extracted quantitatively, at least in principle. The classical theories of colloid science that miss such contributions do not account for a whole variety of ion-specific phenomena. Numerical results that include these non-electrostatic forces are given here for model calculations of the force between two model charge-regulated hen-egg-white protein surfaces. The surfaces are chosen to carry the same charge groups and charge density as the protein. What emerges is that for pHpI (where anions are co-ions) the forces increase in the order NaCl相似文献
99.
Tavares FX Deaton DN Miller AB Miller LR Wright LL 《Bioorganic & medicinal chemistry letters》2005,15(17):3891-3895
Ketoheterocyclic inhibitors of cathepsin K have been disclosed. SAR of potency enhancing P2-P3 groups coupled with ketoheterocyclic warheads to provide cathepsin K inhibitors have been described. In addition, a novel route to access alpha-ketothiazoles using a key thioamide functionality has been disclosed. The mild method employed allows for the presence of diverse functional groups, such as amide and carbamate functionalities, commonly found in protease inhibitors that have peptidomimetic scaffolds. This new method should provide a quick entry into functionally diverse protease inhibitors. 相似文献
100.
Genetic diversity of Histoplasma capsulatum strains in Brazil 总被引:1,自引:0,他引:1
Zancopé-Oliveira RM Morais e Silva Tavares P Muniz MM 《FEMS immunology and medical microbiology》2005,45(3):443-449
This study establishes the genetic relatedness among Brazilian Histoplasma capsulatum samples obtained from different sources. A PCR-based random amplified polymorphic DNA (RAPD) assay was used to delineate polymorphisms among isolates in geographically diverse regions in Brazil. RAPD fingerprints revealed distinct DNA profiles and provided a high level of discrimination among H. capsulatum strains from different locations. Cluster I was composed of H. capsulatum isolates from the northeast region. The majority of strains from southeast and south were categorized as major cluster II. The strain 84564 from Rio de Janeiro State showed no genetic correlation to any of the isolates from the same state. The RAPD patterns of H. capsulatum isolates from Goias (Cluster III) were unrelated to DNA fingerprints observed among the other H. capsulatum strains (48% similarity). This study is the first report that stratifies the clusters of H. capsulatum strains from Brazil by molecular typing and associates them with the geographical origin. 相似文献