The food retail environment and its use in a deprived, urban area of Scotland.

OBJECTIVES: This study sought to describe the food retail environment and its use in a deprived urban area in Scotland by mapping all food outlets and determining where residents do their main food shopping as well as investigating the availability of fresh fruit and vegetables (F&V) (as an indicator of healthy eating) and takeaway food. STUDY DESIGN: Cross-sectional study. METHODS: The food retail environment, the number, size and food availability of all food outlets, was mapped in Viewpark, a small community located to the east of Glasgow. Subsequently a validated questionnaire was used to determined food shopping usage and habits. RESULTS: There was high availability of common fresh fruit and vegetables (F&V) and very high availability of fast food outlets. Only 9% of the sample shopped solely at local food outlets within Viewpark whilst 91% shopped at a large supermarket outside Viewpark (n = 106). Walking was significantly negatively associated (B = -3.555, P = 0.008) with shopping outside the community. The majority of respondents (80%) reported buying F&V weekly and 57% purchased takeaways at least once a week - these individuals were employed, over 45 years old and had at least one child. CONCLUSIONS: The use of the local retail environment in a deprived community is influenced by car accessibility.

Effect of subunit composition on GABAA receptor complex characteristics in a baculovirus expression system.

A baculovirus expression system was used to produce functional human recombinant GABAA receptors in Sf-9 insect cells in order to study the biochemistry, pharmacology and functional characteristics of this receptor complex. We have identified and characterized various factors which influence the level of receptor expression in multiple virus infections. We have shown that the level of expression of the GABAA receptor complex varies with the levels of expression of the individual subunits. We have also shown that the assembly process has a defined timecourse, and it is dependent upon the ratio of the number of infectious virus particles (MOI ratio) of each subunit in multi-virus infections. In multiple infections, the capacity for expression of the infected cell is shared proportionally by entering virus particles and, there is a direct correlation between the amounts of subunit mRNA and levels of subunit protein expression, and the amount of ligand binding to expressed protein. Finally, reinfection of previously infected cells does not result in subsequent protein expression. Knowledge of these various factors allows us to construct recombinant GABAA receptor complexes with reproducibility and flexibility with regard to subunit composition. By co-expression of alpha, beta, and gamma subunits, both the recognition site for GABA and the allosteric (benzodiazepine) modulatory site are formed and appear to reproduce the pharmacology of endogenously expressed receptors as measured in mammalian CNS. Only a single receptor is produced irrespective of the expression levels of the subunits, showing that GABAA receptor assembly is highly regulated.

Human alpha and beta subunits contribute to the EC50 for GABA at the GABAA receptor expressed in Xenopus oocytes.

The GABAA receptor/ionophore complex (GABAAR) may be composed of at least alpha, beta, and gamma subunits. Alpha subunits can influence the concentration of GABA at which a half maximal current response is elicited (EC50). There are no data to suggest that beta subunits can also influence this pharmacological property of the GABAAR. We examined the influence of human derived beta and alpha subunits on the EC50 for GABA. Nine different subunit combinations were evaluated: alpha 1, alpha 2, alpha 3 in combination with beta 1 gamma 2, beta 2 gamma 2, and beta 3 gamma 2. cRNA coding for these subunit combinations was injected into Xenopus oocytes that were subsequently recorded from using the two electrode voltage-clamp technique. A two-way analysis of variance showed that both alpha and beta subunits interact to influence the EC50 of GABAARs. The EC50 for alpha 3 changed significantly with beta subunits. The EC50 for alpha 2 was significantly different in beta 3 compared to beta 1 and beta 2 subunits, while the EC50 for alpha 1 was not significantly different between beta subunits. These findings suggests that other pharmacological and physiological properties may also be determined by interactions between alpha and beta subunits.

Histone H3 and H4 gene deletions in Saccharomyces cerevisiae.

The genome of haploid Saccharomyces cerevisiae contains two nonallelic sets of histone H3 and H4 genes. Strains with deletions of each of these loci were constructed by gene replacement techniques. Mutants containing deletions of either gene set were viable, however meiotic segregants lacking both histone H3 and H4 gene loci were inviable. In haploid cells no phenotypic expression of the histone gene deletions was observed; deletion mutants had wild-type growth rates, were not temperature sensitive for growth, and mated normally. However, diploids homozygous for the H3-H4 gene deletions were slightly defective in their growth and cell cycle progression. The generation times of the diploid mutants were longer than wild-type cells, the size distributions of cells from exponentially growing cultures were skewed towards larger cell volumes, and the G1 period of the mutant cells was longer than that of the wild-type diploid. The homozygous deletion of the copy-II set of H3-H4 genes in diploids also increased the frequency of mitotic chromosome loss as measured using a circular plasmid minichromosome assay.

Analysis of DNA sequences homologous with the ARS core consensus in Saccharomyces cerevisiae.

We have previously identified an autonomously replicating segment (ARS) near the 3' end of the histone H4 gene at the copy-I H3-H4 locus. We have now searched for additional autonomously replicating segments and sequences homologous with the ARS core consensus sequence near the copy-II histone H4 gene and both of the histone H3 genes. No new ARS elements were identified by functional cloning assays. However, several matches to the ARS core consensus element were found within the DNA sequences of the copy-I and copy-II genes. An exact match to the ARS core consensus was identified in the region downstream from the copy-I histone H3 gene and a set of sequences with weak homology was also located within the copy-II region. However, restriction fragments including these sequences did not demonstrate ARS activity on a plasmid in transformed cells.

Protein kinase activities associated with the virions of pseudorabies and herpes simplex virus.

Protein kinase has been extracted in soluble form from virions of pseudorabies virus using 10% NP40, 0.6 M-NaCl. Chromatographic analysis of the extract on DEAE-cellulose and on phosphocellulose showed it to contain more than one kinase. The activity responsible for the phosphorylation of the major phosphoproteins (mol. wts. 120 000, 115 000 and 72 000) of virions was found to be similar in its properties to the host enzyme casein kinase II. Purified casein kinase II from ascites cells or from pig liver was able to phosphorylate heat-inactivated virions. In addition to the major phosphoproteins, active virion preparations were able to phosphorylate a minor low molecular weight phosphoprotein, incorporation into which could be stimulated by the addition of cyclic AMP to the assay. Purified host cyclic AMP-dependent protein kinase also phosphorylated this protein in heat-inactivated virions. Analysis of herpes simplex virus type 1 showed that the major phosphoproteins (VP12 and VP23) could be phosphorylated in heat-inactivated virions by added casein kinase II. One of these (VP12) together with a further minor phosphoprotein (VP14) could be phosphorylated by cyclic AMP-dependent protein kinase.