Executive function in pathological gamblers and healthy controls.

Executive function (EF) deficits may underlie some of the impulse control problems seen in pathological gambling. Pathological gamblers (PGs, n = 45) and controls (n = 45) were compared on several measures of EF (including measures of response inhibition, working memory, cognitive flexibility and perseveration, planning and decision-making), as well as memory and intelligence tests to examine whether PGs evidence EF dysfunction. Compared with controls, PGs exhibited specific deficits on measures of planning and decision-making.

Entrapment of fluorescence signaling DNA enzymes in sol-gel-derived materials for metal ion sensing.

Three fluorescence signaling DNA enzymes (deoxyribozymes or DNAzymes) were successfully immobilized within a series of sol-gel-derived matrixes and used for sensing of various metal ions. The DNAzymes are designed such that binding of appropriate metal ions induces the formation of a catalytic site that cleaves a ribonucleotide linkage within a DNA substrate. A fluorophore (fluorescein) and a quencher (DABCYL, [4-(4-dimethylaminophenylazo)benzoic acid]) were placed on the two deoxythymidines flanking the ribonucleotide to allow the generation of fluorescence upon the catalytic cleavage at the RNA linkage.

Quenching of fluorophore-labeled DNA oligonucleotides by divalent metal ions: implications for selection, design, and applications of signaling aptamers and signaling deoxyribozymes.

Recent years have seen a dramatic increase in the use of fluorescence-signaling DNA aptamers and deoxyribozymes as novel biosensing moieties. Many of these functional single-stranded DNA molecules are either engineered to function in the presence of divalent metal ion cofactors or designed as sensors for specific divalent metal ions. However, many divalent metal ions are potent fluorescence quenchers.

Nanovolume kinase inhibition assay using a sol-gel-derived multicomponent microarray.

We report on the development of a new class of kinase microarrays based on the coimmobilization of both kinase and substrate components within a single pin-printed sol-gel microarray element and the use of such arrays for nanovolume inhibition assays. We successfully immobilized the alpha-catalytic subunit of cAMP-dependent protein kinase (PKA) and the peptide substrate kemptide within sol-gel-derived microarrays for the purpose of monitoring phosphorylation and inhibition. Using Pro-Q Diamond stain as an end-point indicator of phosphorylation, we demonstrate the selective detection of phosphoproteins over nonphosphorylated controls and the ability to detect phosphorylated proteins over a 500-fold concentration range.

Entrapment of fluorescent signaling DNA aptamers in sol-gel-derived silica.

We report on the first successful immobilization of a DNA aptamer, in particular, a fluorescence-signaling DNA aptamer, within a sol-gel-derived matrix. The specific aptamer examined in this study undergoes a structural switch in the presence of adenosine triphosphate (ATP) to release a dabcyl-labeled nucleotide strand (QDNA), which in turn relieves the quenching of a fluorescein label that is also present in the aptamer structure. It was demonstrated that aptamers containing a complementary QDNA strand along with either a short complimentary strand bearing fluorescein (tripartite structure) or a directly bound fluorescein moiety (bipartite structure) remained intact upon entrapment within biocompatible sol-gel derived materials and retained binding activity, structure-switching capabilities, and fluorescence signal generation that was selective and sensitive to ATP concentration.

First Year Impacts of Casino Gambling in a Community.

Gambling has become both a major pastime for Canadians and a multibillion dollar industry providing provincial governments with an increasing proportion of their annual revenues. The continuing trend toward the legalization of gambling has made research on the public health impacts of gambling increasingly important to citizens and decision-makers. This article presents first year results of a multi-year project to measure the impact of the opening of Casino Windsor on gambling behaviour in Windsor, Ontario, Canada.