Liposomal nanomedicines: an emerging field.

Liposomal nanoparticles (LNs) encapsulating therapeutic agents, or liposomal nanomedicines (LNMs), represent one of the most advanced classes of drug delivery systems, with several currently on the market and many more in clinical trials. During the past 20 years, a variety of techniques have been developed for encapsulating both conventional drugs and the new genetic drugs (plasmid DNA-containing therapeutic genes, antisense oligonucleotides, and small, interfering RNA [siRNA]) within LNs encompassing a very specific set of properties: a diameter centered on 100 nm, a high drug-to-lipid ratio, excellent retention of the encapsulated drug, and a long (>6 hours) circulation lifetime. Particles with these properties tend to accumulate at sites of disease, such as tumors, where the endothelial layer is "leaky" and allows extravasation of particles with small diameters.

Modelling overdispersion in longitudinal count data in clinical trials with application to epileptic data.

A family of multi-level models with different types of random error components in the linear predictor is presented for analysing longitudinal count data in clinical trials. These models account for overdispersion, heterogeneity, serial correlation, and heteroscedasticity. The proposed models are applied to epileptic seizure count data and illustrated in a simulation study.

Liposomal nanomedicines.

Liposomal nanoparticles (LNs) encapsulating therapeutic agents, or liposomal nanomedicines, represent an advanced class of drug delivery systems, with several formulations presently on the market and many more in clinical trials. Over the past 20 years, a variety of techniques have been developed for encapsulating both conventional drugs (such as anticancer drugs and antibiotics) and the new genetic drugs (plasmid DNA containing therapeutic genes, antisense oligonucleotides and small interfering RNA) within LNs. If the LNs possess certain properties, they tend to accumulate at sites of disease, such as tumours, where the endothelial layer is 'leaky' and allows extravasation of particles with small diameters.

Dynamic effects of nonequilibrium solvation: potential and free energy surfaces for Z/E isomerization in solvent-solute coordinates.

A novel definition of a solvent coordinate associated with a given reaction is formulated in terms of molecular-dynamic trajectories of the solvent and is applied to discuss the topography of potential energy and free energy surfaces of model liquid phase Z/E isomerization reactions in solvent-solute coordinates. It is shown that the arrangement of the reactant and product valleys on these surfaces can vary from consecutive to parallel, depending on the strength of the solvent-solute interactions.

Electromyographic activity of the trunk stabilizers during stable and unstable bench press.

The purpose of this study was to investigate the effectiveness of instability training in the recruitment of core stabilizing muscles during dynamic multijoint movement. Surface electromyography (EMG) was measured from 6 muscles (latissimus dorsi, rectus abdominus, internal obliques, erector spinae, and soleus) while subjects performed a 9.1-kg bench press on stable and unstable surfaces.

Determining physical activity patterns of suburban British Columbia residents.

Background: Physical activity is well recognized for its role in disease prevention. Public health surveillance and action is warranted to combat the escalating economic and human costs associated with physical inactivity.

Methods: This study examined the proportion of the population who were physically active at intensities, durations and frequencies specified as the minimum to accrue health benefit as per Canada's Physical Activity Guidelines.

Relational ethics and advocacy in nursing: literature review.

Aim: The purpose of this paper is to analyse themes from accounts of nurses' experiences with advocacy that may expand our understanding of advocacy in nursing practice.

Background: Although the ethical obligation to advocate is universal, a lack of clarity persists about the nature of advocacy in nursing practice.

Method: This discussion of advocacy is based on a synthesis of qualitative studies that focus on nurses' experiences with advocacy in practice.

How the Chlorophyll-Proteins got their Names.

This is the story of how we started studying the green bands seen on SDS-polyacrylamide gels of thylakoid membranes dissociated with the non-ionic detergent beta-octyl-D-glucopyranoside. We explain some of the complications we and other workers encountered along the pathway to untangling the chlorophyll-protein complexes of higher plants, and give a concise summary of the complexes, their polypeptides and their genes.

Influence of moderate prophylactic compression on sport performance.

This study examined the impact of using elasticized compression shorts on performance measures and proprioception at the hip. Thirteen healthy subjects completed 2 randomized testing sessions-one while wearing the Coreshorts compression shorts and one while not wearing the shorts. During each trial, active range of motion at the hip; joint angle replication during hip flexion, abduction, and hyperextension; leg power; agility; speed; and aerobic endurance were measured, and subjective information pertaining to the fit of the shorts was collected.

The effect of Parkinson's disease on the control of multi-segmental coordination.

An experiment was designed to test whether or not Parkinson's disease (PD) patients were able to maintain endpoint kinematic patterns in a prehension task involving movement of the torso. Nine PD patients and nine healthy controls were asked to reach for and grasp a full cup of water that was either covered or uncovered and placed beyond the reach of the outstretched arm. An OPTOTRAK (Northern Digital) 3-dimensional motion analysis system was used to capture the movement of four markers placed on the arm, hand, and torso.

Stress, social support, and sense of coherence.

In the Salutogenic Model, Aaron Antonovsky suggested that a sense of coherence (SOC) is the key determinant in the maintenance of health. He theorized that individuals with a strong SOC have the ability to (a) define life events as less stressful (comprehensibility), (b) mobilize resources to deal with encountered stressors (manageability), and (c) possess the motivation, desire, and commitment to cope (meaningfulness). To determine the effects of SOC on health outcomes, a greater understanding of the development and maintenance of SOC is necessary.

Human morphology and temperature regulation.

For nearly a century individuals have believed that there is a link between human morphology and one's thermoregulatory response in adverse environments. Most early research was focussed on the rate of core cooling in a male adult population and the role of subcutaneous adipose tissue, surface area and the surface-area-to-mass ratio in one's ability to withstand varying degrees of cold stress. More recently research has addressed heat tolerance in various populations, exploring the role of subcutaneous adipose tissue, surface area and the surface-area-to-mass ratio in one's ability to maintain thermal equilibrium in warm and hot, dry and humid environments.

alpha 1B N-type calcium channel isoforms with distinct biophysical properties.

N-type calcium channels both generate the initial calcium signal to trigger neurotransmitter release and also interact with synaptic release proteins at many mammalian central nervous system synapses. Two isoforms of the alpha 1B N-type channel from rat brain (alpha 1B-I and alpha 1B-II) were found to differ in four regions: (1) a glutamate (Glu) to glycine (Gly) substitution in domain I S3; (2) a Gly to Glu substitution in the domain I-II linker; (3) the insertion or deletion of an alanine (Ala) in the domain I-II linker; and (4) the presence or absence of serine/phenylalanine/methionine/glycine (SFMG) in the linker between domain III S3-S4. Comparison of the electrophysiological properties of the alpha 1B-I and alpha 1B-II N-type channels shows that they exhibit distinct kinetics as well as altered current-voltage relations.

Thermoregulatory responses of circum-pubertal children.

Passive temperature lability of nine circum-pubertal children [11.4 (1.2) years] was compared to that of nine young adult males [26.

Gender differences in physiological reactions to thermal stress.

Following an extensive anthropometric evaluation, thermoregulatory responses were studied in nine men and nine women who performed immersed exercise with post-exercise rest in 28 degrees C water. During the post-exercise period esophageal temperature (Tes), oxygen consumption, heat flux and skin blood perfusion were monitored at 10 s intervals, with average minute values used for calculations. The delta Tes (relative to resting Tes) at which sweating abated and shivering commenced were defined as the delta Tes thresholds for the cessation of sweating and onset of shivering, respectively.

Calculated thermal conductivities and heat flux in man.

Using data compiled by the Brussels Cadaver Analysis Study on 13 unembalmed cadavers, this study examined the validity of assumptions often made concerning the role of the skin and adipose tissue layers in thermal insulation in vivo. Skin thickness was previously reported to vary from 0.35 to 2.

Deviance estimates of sample size for equivalence tests in vaccine trials.

This paper proposes a sample size procedure for both equivalence and conventional tests for the comparison of two binomial proportions, based on the signed square root of the deviance. When the comparison is based on the odds ratio, I describe an alternate 'close' conditional exact method that gives results that support those given by the deviance method. I summarize the advantages of the deviance-based method and also show that in general equivalence situations the sample size estimate depends upon the measure of comparison selected, odds ratio, risk ratio or risk difference.

The memory representation of motor skills: a test of schema theory.

Currently, a popular model for the central representation of motor skills is embodied in Schmidt's schema theory of discrete motor skill learning (Schmidt, 1975). Two experiments are reported here that contrast predictions from a schema abstraction model that is the basis for schema theory with those from an exemplar-based model of motor skill memory representation. In both experiments, subjects performed 300 trials per day of three variations of a three-segment timing task over 4 days of acquisition.

A note on schema and exemplar approaches to motor skill representation in memory.

Given the need for a memory representation of well-learned motor skills, a common assumption in motor behavior is that this knowledge is stored in a central, abstracted form. Active production of motor skills has not been used in experimental designs that have provided empirical support for this view of representation, however. Much of the faith in centralized, abstracted forms of memory representation for motor skills is due to the popularity of Schmidt's schema theory, which has adapted the prototype abstraction model from category learning research to the representation of motor skills.