Experiments were conducted, using a nonspecific lipid transfer protein, to vary the cholesterol/phospholipid molar ratio of rat proximal small intestinal microvillus membranes in order to assess the possible role of cholesterol in modulating enzymatic activities of this plasma membrane. Cholesterol/phospholipid molar ratios from 0.71 to 1.30 were produced from a normal value of 1.05 by incubati...

We studied the effect of cyclosporin A (CyA) on liver plasma membrane (LPM) composition, fluidity, and functions and on hepatic glutathione (GS) and oxidative status. We also evaluated the ability of S-adenosylmethionine (SAMe) to antagonize the CyA-induced disturbances in rats. The animals were randomly divided into four groups and treated daily with saline, CyA vehicle, CyA, and SAMe plus CyA...

Ethanol can be used as a chemical tool to alter membrane fluidity or composition, or both, and to study the effects on induction, growth, spread, or treatment of cancers. Ethanol rapidly equilibrates with total body water and enters all cell membranes. Ethanol molecules are intercalated between the lipids of the bilayer membranes. This expands membranes and increases their fluidity, which in tu...

It is well known that cellular cultures grown at different temperatures will display altered membrane lipid composition to maintain a relatively constant membrane fluidity across a range of temperatures. One of the proposed theories on the mechanism of chemically-induced transformation is that a higher temperature of the heat-shock step increases the fluidity of the host cell membrane, allowing...

Superparamagnetic iron oxide nanoparticles (SPIONs) with multifunctional properties have shown great promise in theranostics. The aim of our work was to compare the effects of SPIONs on the fluidity and phase transition of the liposomal membranes prepared with zwitterionic phosphatidylcholine lipids. In order to study if the surface modification of SPIONs has any influence on these membrane pro...

This study was undertaken to investigate possible relationships among plasma adiponectin, 8-iso-prostaglandin F2α (8-iso-PG F2α: an index of oxidative stress), and membrane fluidity (a reciprocal value of microviscosity) in hypertensive and normotensive men using an electron spin resonance-method. The order parameter (S) for the spin-label agent (5-nitroxide stearate) in red blood cell (RBC) me...

OBJECTIVE To assess the physicochemical characteristics of sperm plasma membrane and to evaluate the immunohistochemical expression of transmembrane and cytoskeletal proteins in spermatozoa isolated from normospermic fertile donors and asthenozoospermic infertile patients. DESIGN Case-control study. SETTING Academic male infertility center. PATIENT(S) Twenty-five infertile patients affect...

We show that fluid organizations display higher levels of cooperation than attainable by groups with either a fixed social structure or lacking one altogether. By moving within the organization, individuals cause restructurings that facilitate cooperation. Computer experiments simulating fluid organizations faced with a social dilemma reveal a myriad of complex cooperative behaviors that result...

PROVIDENCE – A unique curated multimedia art exhibit on Alzheimer’s disease (AD) opened in the Cohen Gallery at the Granoff Center for the Creative Arts at Brown on July 16. As you enter the gallery, the visual expression of the ravages of AD by neuroscientist PETER J. SNYDER, PHD, titled Collapse of a Memory Circuit, draws in the visitor by its size, scope and fluidity. It looks like a giant 3...