Extensive microscopic molecular dynamics simulations have been performed to study the effects of short-chain alcohols, methanol and ethanol, on two different fully hydrated lipid bilayer systems (POPC and DPPC) in the fluid phase at 323 K. It is found that ethanol has a stronger effect on the structural properties of the membranes. In particular, the bilayers become more fluid and permeable: ethanol molecules are able to penetrate through the membrane in typical timescales of approximately 200 ns, whereas for methanol that timescale is considerably longer, at least of the order of microseconds. A closer examination exposes a number of effects due to ethanol. Hydrogen-bonding analysis reveals that a large fraction of ethanols is involved in hydrogen bonds with lipids. This in turn is intimately coupled to the ordering of hydrocarbon chains: we find that binding to an ethanol decreases the order of the chains. We have also determined the dependence of lipid-chain ordering on ethanol concentration and found that to be nonmonotonous. Overall, we find good agreement with NMR and micropipette studies.

We summarize and compare recent Molecular Dynamics simulations on the interactions of dipalmitoylphosphatidylcholine (DPPC) bilayers in the liquid crystalline phase with a number of small molecules including trehalose, a disaccharide of glucose, alcohols, and dimethylsulfoxide (DMSO). The sugar molecules tend to stabilize the structure of the bilayer as they bridge adjacent lipid headgroups. They do not strongly change the structure of the bilayer. Alcohols and DMSO destabilize the bilayer as they increase its area per molecule in the bilayer plane and decrease the order parameter. Alcohols have a stronger detrimental effect than DMSO. The observables which we compare are the area per molecule in the plane of the bilayer, the membrane thickness, and the NMR order parameter of DPPC hydrocarbon tails. The area per molecule and the order parameter are very well correlated whereas the bilayer thickness is not necessarily correlated with them.

We summarize and compare recent Molecular Dynamics simulations on the interactions of dipalmitoylphosphatidylcholine (DPPC) bilayers in the liquid crystalline phase with a number of small molecules including trehalose, a disaccharide of glucose, alcohols, and dimethylsulfoxide (DMSO). The sugar molecules tend to stabilize the structure of the bilayer as they bridge adjacent lipid headgroups. They do not strongly change the structure of the bilayer. Alcohols and DMSO destabilize the bilayer as they increase its area per molecule in the bilayer plane and decrease the order parameter. Alcohols have a stronger detrimental effect than DMSO. The observables which we compare are the area per molecule in the plane of the bilayer, the membrane thickness, and the NMR order parameter of DPPC hydrocarbon tails. The area per molecule and the order parameter are very well correlated whereas the bilayer thickness is not necessarily correlated with them.

<b><i>Background:</i></b> Intranasal steroid (INS) is the most effective medication class for controlling allergic rhinitis (AR) symptoms; however, its effectiveness is limited by patient compliance. Previous studies have explored INS use, compliance, satisfaction, and experience. There is, however, no Asian study on these factors in entirety. <b><i>Objective:</i></b> We aimed to investigate the rate of compliance to usage of INS and explore the reasons for noncompliance in our local population. <b><i>Methods:</i></b> We conducted a prospective cross-sectional study on 65 AR patients in a tertiary hospital. Recruited patients were administered a questionnaire to collect data about symptoms, INS use, and concerns they may have. Statistical analysis was performed using SPSS. <b><i>Results:</i></b> The overall compliance rate to INS was 63.1%. Noncompliance was associated with increased frequency of dosing (<i>p</i> = 0.050), presence of sensory attributes (<i>p</i> = 0.041), and forgetfulness (<i>p</i> = 0.049). The top 3 most frequent sensory attributes experienced by patients include throat rundown (29.2%), aftertaste (21.5%), and immediate taste (20.0%). There was a significant difference between brands of INS with regard to sensory attributes experienced (<i>p</i> = 0.003) but no side effects (<i>p</i> = 0.070). <b><i>Conclusions:</i></b> Identifying risk factors for noncompliance to INS can help health-care providers address difficulties faced by patients and hence increase compliance, allowing better control of AR symptoms.