Communicative dimensions of pain catastrophizing: social cueing effects on pain behaviour and coping.

The study was designed to assess whether the social context of a pain experience impacted on the relation between catastrophizing and duration of pain behaviour. Based on a communal coping model, the prediction was that the presence of an observer during a pain procedure would differentially influence the display of pain behaviour in high and low catastrophizers. University undergraduates taking part in a cold pressor procedure were randomly assigned to one of two conditions: (1) participant alone (n=30), or (2) observer present (n=34).

"Out-of-pitch" but still "in-time". An auditory psychophysical study in congenital amusic adults.

Congenital amusia is a lifelong disability, commonly known as tone deafness, that prevents afflicted individuals from developing basic musical skills despite normal audiometry and above-average intellectual, memory, and language skills. Although it is estimated that 4% of the general population would be born with such a musical handicap, the underlying cause is presently unknown. Recently, we proposed that this disorder could be traced to a deficit in pitch perception on the basis of a single case.

Gender and the social context of smoking behaviour.

This paper examines the relative effect of both individual and societal factors that impinge directly on smoking behaviour of women and men. The societal factors are cigarettes price, tobacco control legislation, newspaper coverage of tobacco issues, overall economic factors, and social milieu characteristics. Three Canadian provinces are studied, from 1978 to 1995.

On the use of isoflurane versus halothane in the study of visual response properties of single cells in the primary visual cortex.

Halothane is a widely used anesthetic in research. It produces several alterations in organs, especially in the brain. Recently, isoflurane emerged in neuroscience laboratories.

What is specific to music processing? Insights from congenital amusia.

Musical abilities are generally regarded as an evolutionary by-product of more important functions, such as those involved in language. However, there is increasing evidence that humans are born with musical predispositions that develop spontaneously into sophisticated knowledge bases and procedures that are unique to music. Recent findings also suggest that the brain is equipped with music-specific neural networks and that these can be selectively compromised by a congenital anomaly.

Interactions of the Caulobacter crescentus XerC and XerD recombinases with the E. coli dif site.

In most bacteria, chromosome dimers arise from homologous recombination between replicated chromosomes. These dimers are then resolved by the action of the XerC and XerD recombinases, which act on the chromosomal dif site in the presence of the FtsK cell division protein. We have cloned the xerC and xerD genes from Caulobacter crescentus, and overexpressed them as maltose-binding protein fusion proteins.

Effects of inducing physiological hyperglucagonemia on metabolic responses to exercise.

The purpose of the present study was to assess the effects of exogenously increasing the circulating levels of glucagon on the metabolic responses to exercise in rats. A total of six groups of rats were infused (iv) either with glucagon (20 or 50 ng x kg(-1) x min(-1)) or saline (0.9% NaCl), either in the resting state or during a bout of running exercise (45 min, 26 m x min(-1), 0% grade).

On the characterization of pH-sensitive liposome/polymer complexes.

A randomly alkylated copolymer of N-isopropylacrylamide, methacrylic acid and N-vinyl-2-pyrrolidone was characterized with regard to its pH- and temperature-triggered conformational change. It was then complexed to liposomes to produce pH-responsive vesicles. Light scattering and differential scanning calorimetry experiments performed at neutral pH revealed that the polymer underwent coil-to-globule phase transition over a wide range of temperatures.

Polymer based pH-sensitive carriers as a means to improve the cytoplasmic delivery of drugs.

pH-sensitive niosomal and liposomal formulations bearing alkylated N-isopropylacrylamide (NIPAM) copolymers were characterized with regard to vesicle-polymer interaction, pH-responsiveness and stability in human serum. The interactions between the pH-sensitive NIPAM copolymer and the vesicles were studied by spectrofluorimetry, using covalently-attached pyrene as a probe. In contrast to liposomes, where complexation of copolymer to the lipid bilayer is essentially mediated by hydrophobic interactions, the binding between niosomes and PNIPAM was mainly driven by hydrogen bonding.

Steric stabilization of liposomes by pH-responsive N-isopropylacrylamide copolymer.

The aim of this study was to characterize a pH-sensitive liposome formulation bearing a terminally alkylated N-isopropylacrylamide (NIPAM) copolymer with regard to its pH responsiveness, surface properties, and pharmacokinetics. The interacting forces between two lipid bilayers bearing the anchored NIPAM copolymer were measured with a surface force apparatus. The pH-triggered content release was evaluated in buffer before and after incubation in human serum.

[Social inequalities in health. A partnership of research and education].

The Chair on Health Inequality is one of the 12 Chairs created by the CHSRF. Resulting from a partnership between l'Université de Montréal, together with the Direction de la santé publique of the Régie régionale de la santé et des services sociaux Montréal-centre, the Chair will create a research program that will document and assess the role of public health programs based on social development in urban districts, in reducing social health inequality. This research infrastructure will support two training programs: 1) a post-doctoral training program that will introduce newly minted social science PhDs to collaborative research in public health; and 2) a professional doctorate program for public health professionals.

In vitro evaluation of pH-sensitive polymer/niosome complexes.

Large unilamellar niosome and control liposome vesicles were rendered pH-sensitive by complexation with a hydrophobically modified pH-responsive copolymer of N-isopropylacrylamide, N-glycidylacrylamide, and N-octadecylacrylamide at a copolymer/lipid mass ratio of 0.3. The vesicles were characterized and tested for their stability and pH-sensitivity in buffer and human serum.

N-isopropylacrylamide copolymers for the preparation of pH-sensitive liposomes and polymeric micelles.

Hydrophobically-modified copolymers of N-isopropylacrylamide bearing a pH-sensitive moiety were investigated for the preparation of pH-responsive liposomes and polymeric micelles. The copolymers having the hydrophobic anchor randomly distributed within the polymeric chain were found to more efficiently destabilize egg phosphatidylcholine (EPC)/cholesterol liposomes than the alkyl terminated polymers. Release of both a highly-water soluble fluorescent contents marker, pyranine, and an amphipathic cytotoxic anti-cancer drug, doxorubicin, from copolymer-modified liposomes was shown to be dependent on pH, the concentration of copolymer, the presence of other polymers such as polyethylene glycol, and the method of preparation.

Effects of steam sterilization on thermogelling chitosan-based gels.

A new thermogelling chitosan-glycerophosphate system has been recently proposed for biomedical applications such as drug and cell delivery. The objectives of this work were to characterize the effect of steam sterilization on the in vitro and in vivo end performances of the gel and to develop a filtration-based method to assess its sterility. Autoclaving 2% (w/v) chitosan solutions for as short as 10 min resulted in a 30% decrease in molecular weight, 3-5-fold decrease in dynamic viscosity, and substantial loss of mechanical properties of the resulting gel.

Larger effect of aging on the perception of higher-order stimuli.

Widespread deficits are known to accompany normal aging. Contrast thresholds of older and younger observers were measured for static and drifting gratings defined by luminance (first-order) or by contrast (second-order), and for a temporally segmented second-order motion stimulus. Results showed that older individuals had a larger threshold elevation for the perception of second-order stimuli than for the perception of first-order stimuli.