Brain tumor stem cell dancing.

Background: Issues regarding cancer stem cell (CSC) movement are important in neurosphere biology as cell-cell or cell-environment interactions may have significant impacts on CSC differentiation and contribute to the heterogeneity of the neurosphere.

Aims: Despite the growing body of literature data on the biology of brain tumor stem cells, floating CSC-derived neurospheres have been scarcely characterized from a morphological and ultrastructural point of view.

Results: Here we report a morphological and ultrastructural characterization performed by live imaging and scanning electron microscopy.

Native metastable prefibrillar oligomers are the most neurotoxic species among amyloid aggregates.

Many proteins belonging to the amyloid family share the tendency to misfold and aggregate following common steps, and display similar neurotoxicity. In the aggregation pathway different kinds of species are formed, including several types of oligomers and eventually mature fibers. It is now suggested that the pathogenic aggregates are not the mature fibrils, but the intermediate, soluble oligomers.

Interaction of tea tree oil with model and cellular membranes.

Tea tree oil (TTO) is the essential oil steam-distilled from Melaleuca alternifolia, a species of northern New South Wales, Australia. It exhibits a broad-spectrum antimicrobial activity and an antifungal activity. Only recently has TTO been shown to inhibit the in vitro growth of multidrug resistant (MDR) human melanoma cells.

Early stages of salmon calcitonin aggregation: effect induced by ageing and oxidation processes in water and in the presence of model membranes.

The natural ageing- and hydrogen peroxide-induced aggregation of salmon calcitonin were studied in water and in the presence of dipalmitoylphosphatidylcholine (DPPC) liposomes. The early stages of the aggregation process at low protein concentration were investigated by means of Circular Dichroism spectroscopy (CD) and conventional and immunogold labelling Transmission Electron Microscopy (TEM). In buffered water solution, salmon calcitonin showed a two-stage conformational variation related to fibril formation and phase-separation of larger aggregates.

Distribution of GD3 in DPPC monolayers: a thermodynamic and atomic force microscopy combined study.

Gangliosides are the main component of lipid rafts. These microdomains, floating in the outer leaflet of cellular membrane, play a key role in fundamental cellular functions. Little is still known about ganglioside and phospholipid interaction.

P-glycoprotein inserted in planar lipid bilayers formed by liposomes opened on amorphous carbon and Langmuir-Blodgett monolayer.

The insertion of proteins into planar lipid layers is of outstanding interest as the resulting films are suitable for the investigation of protein structure and aggregation in a lipid environment and/or the development of biotechnological applications as biosensors. In this study, purified P-glycoprotein (P-gp), a membrane drug pump, was incorporated in model membranes deposited on solid supports according to the method by Puu and Gustafson, Biochim. Biophys.