Amblyomma cajennense (Acari : Ixodidae): Salivary gland cells of partially engorged females ticks and the production of lipid by their mitochondria

Morphologically,. The salivary glands of ticks are paired structures consisting of a secretory and an excretory portion, lacking a reservoir for the storage of the secretion. The secretory portion is composed in females by cells that form acini classified into the types I, II, and III. The excretory possess a major duct, from which arise several intermediate ducts that then subdivide to form the canaliculi or acinal tubules, which end at the acini from where they collect the secretion. The present Study describes the ultrastructural changes that occur in the mitochondria of cells of the acini I, II, and III in the salivary glands of partially engorged females of the Cayenne tick Amblyomma cajennense. The results show that this organelle exhibits completely disarrayed crests due to the presence of lipidic material inside the matrix and between the crests, thus demonstrating their participation in the production of the lipids that would be used structurally by the cells. These organelles with ultrastructural changes were denominated derived mitochondria. (c) 2005 Elsevier B.V. All rights reserved.

Recovery of rat growth and lipid profiles in adult rats subjected to fetal protein malnutrition with a fructose-rich diet

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Exercise and spirulina control non-alcoholic hepatic steatosis and lipid profile in diabetic Wistar rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of physical training with different intensities of effort on lipid metabolism in rats submitted to the neonatal application of alloxan

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bioactive Compounds in Lipid Fractions of Pumpkin (Cucurbita sp) Seeds for Use in Food

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Interaction between Pluronic F127 and Dioctadecyldimethylammonium Bromide (DODAB) Vesicles Studied by Differential Scanning Calorimetry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

DODAB and DODAC bilayer-like aggregates in the micromolar surfactant concentration domain

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Selectivity in the mechanism of action of antimicrobial mastoparan peptide Polybia-MP1

Many potent antimicrobial peptides also present hemolytic activity, an undesired collateral effect for the therapeutic application. Unlike other mastoparan peptides, Polybia-MP1 (IDWKKLLDAAKQIL), obtained from the venom of the social wasp Polybia paulista, is highly selective of bacterial cells. The study of its mechanism of action demonstrated that it permeates vesicles at a greater rate of leakage on the anionic over the zwitterionic, impaired by the presence of cholesterol or cardiolipin; its lytic activity is characterized by a threshold peptide to lipid molar ratio that depends on the phospholipid composition of the vesicles. At these particular threshold concentrations, the apparent average pore number is distinctive between anionic and zwitterionic vesicles, suggesting that pores are similarly formed depending on the ionic character of the bilayer. To prospect the molecular reasons for the strengthened selectivity in Polybia-MP1 and its absence in Mastoparan-X, MD simulations were carried out. Both peptides presented amphipathic alpha-helical structures, as previously observed in Circular Dichroism spectra, with important differences in the extension and stability of the helix; their backbone solvation analysis also indicate a different profile, suggesting that the selectivity of Polybia-MP1 is a consequence of the distribution of the charged and polar residues along the peptide helix, and on how the solvent molecules orient themselves according to these electrostatic interactions. We suggest that the lack of hemolytic activity of Polybia-MP1 is due to the presence and position of Asp residues that enable the equilibrium of electrostatic interactions and favor the preference for the more hydrophilic environment.

New Insight into the Mechanism of Action of Wasp Mastoparan Peptides: Lytic Activity and Clustering Observed with Giant Vesicles

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Aggregation behavior of aqueous dioctadecyldimethylammonium bromide/monoolein mixtures: A multitechnique investigation on the composition and temperature

A recently described non-viral gene delivery system [dioctadecyldimethylammonium bromide (DODAB)/monoolein (MO)] has been studied in detail to improve knowledge on the interactions between lamellar (DODAB) and non-lamellar-forming (MO) lipids, as a means to enhance their final cell transfection efficiency. Indeed, the morphology, fluidity, and size of these cationic surfactant/neutral lipid mixtures play an important role in the ability of these systems to complex nucleic acids. The different techniques used in this work, namely dynamic light scattering (DLS), fluorescence spectroscopy, differential scanning calorimetry (DSC), cryogenic transmission electron microscopy (cryo-TEM), light microscopy (LM), and surface pressure-area isotherms, allowed fully characterization of the phase behavior and aggregate morphology of DODAB/MO mixtures at different molar ratios. Overall, the results indicate that the final morphology of DODAB/MO aggregates depends on the balance between the tendency of DODAB to form zero-curvature bilayer structures and the propensity of MO to form non-bilayer structures with negative curvature. These results also show that in the MO-rich region, an increase in temperature has a similar effect on aggregate morphology as an increase in MO concentration. (C) 2012 Elsevier B.V. All rights reserved.

Thermal and Structural Behavior of Dioctadecyldimethylammonium Bromide Dispersions Studied by Differential Scanning Calorimetry and X-Ray Scattering

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Salinity influences glutathione S-transferase activity and lipid peroxidation responses in the Crassostrea gigas oyster exposed to diesel oil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

In vitro exposure to fullerene C60 influences redox state and lipid peroxidation in brain and gills from Cyprinus carpio (Cyprinidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Finite-momentum condensate of magnetic excitons in a bilayer quantum Hall system

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The membranotropic activity of N-terminal peptides from the pore-forming proteins sticholysin I and II is modulated by hydrophobic and electrostatic interactions as well as lipid composition

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)