Miscibility of dl-α-tocopherol ß-glucoside in DPPC monolayer at air/water and air/solid interfaces.

The role of newly synthesized tocopherol glycosidic derivative in modifying molecular organization and phase transitions of phospholipid monolayer at the air/water interface has been investigated. Two-component Langmuir films of dl-α-tocopheryl ß-D-glucopyranoside (BG) mixed with dipalmitoyl phosphatidylcholine (DPPC) in the whole range of mole fractions were formed at the water surface. An analysis of surface pressure versus mean molecular area (π-A) isotherms and Brewster angle microscope images showed that the presence of BG molecules changes the structure and packing of the DPPC monolayer in a BG concentration dependent manner. BG molecules incorporated into DPPC monolayer inhibit its liquid expanded to liquid condensed phase transition proportionally to the BG concentration. The monolayers were also transferred onto solid substrates and visualized using an atomic force microscope. The results obtained indicate almost complete miscibility of BG and DPPC in the monolayers at surface pressures present in the biological cell membrane (30-35·10(-3) N·m(-1)) for a BG mole fraction as high as 0.3. This makes the monolayer less packed and more disordered, leading to an increased permeability. The results support our previous molecular dynamics simulation data.

[The influence of genes on the development of personality]. / Wplyw genów na ksztaltowanie sie cech osobowosci.

Antisocial behavior and personality disorders are both heterogeneous and the product of interacting genetic and environmental factors acting at different levels of causation. Heritability studies show that individual differences in predisposition to antisocial behavior are transmitted by genetic mechanisms in families. Direct gene analysis and genetic linkage analysis have identified structural variants in genes involved in neurotransmitter function, and some progress has been made towards relating these genetic variants to antisocial personality and other behaviors. The monoamine oxidase-A variant leads to aggressive behavior in one family. Direct gene analyses have revealed amino acid substitutions and structural variants at DRD2, DRD3 and DRD4 dopamine receptors and 5-HT2A, 5-HT2C serotonin receptors, serotonin transporter gene, and genes for enzymes, metabolizing biogenic amines MAO-A, MAO-B. The stage is set to identify the phenotypic significance of these as well as genetic variants at other loci which may be relevant as candidate genes for antisocial behavior and related behavioral differences.