Contribution of climate and air pollution to variation in coronary heart disease mortality rates in England

There are substantial geographic variations in coronary heart disease (CHD) mortality rates in England that may in part be due to differences in climate and air pollution. An ecological cross-sectional multi-level analysis of male and female CHD mortality rates in all wards in England (1999–2004) was conducted to estimate the relative strength of the association between CHD mortality rates and three aspects of the physical environment - temperature, hours of sunshine and air quality. Models were adjusted for deprivation, an index measuring the healthiness of the lifestyle of populations, and urbanicity. In the fully adjusted model, air quality was not significantly associated with CHD mortality rates, but temperature and sunshine were both significantly negatively associated (p<0.05), suggesting that CHD mortality rates were higher in areas with lower average temperature and hours of sunshine. After adjustment for the unhealthy lifestyle of populations and deprivation, the climate variables explained at least 15% of large scale variation in CHD mortality rates. The results suggest that the climate has a small but significant independent association with CHD mortality rates in England.

General practice : contribution to health and equity

The evidence that a primary health approach enhances health outcomes, increases system effectiveness and is cost effective gives a new impetus for general practice within the continuum of health services. At the same time, in Australia the establishment of the Divisions of General Practice and their continued support has led to a new found confidence in general practice.

Five-year changes in school recess and lunchtime and the contribution to children’s daily physical activity

Objective To investigate the longitudinal changes in children's recess and lunchtime physical activity levels and in the contribution of recess and lunchtime to daily physical activity levels over 5 years among 5–6- and 10–12-year olds.

Methods Data were drawn from two longitudinal studies that were conducted in metropolitan Melbourne, Australia. Boys and girls (n=2782) aged 5–6 years and 10–12 years participated in baseline (T0) measures. Physical activity (n=2490) was measured every 60 s for eight consecutive days using hip-mounted accelerometry. Subsequent measurements were taken at 3-year (T1; n=773) and 5-year (T2; n=634) follow-up. Physical activity intensities were derived using age-adjusted cut-points. Sedentary time was defined as 100 counts/min. Longitudinal data were analysed using three-level (time, child, school) multilevel analyses, stratified by sex and cohort, and adjusted for potential confounding variables.

Results Significant decreases in recess and lunchtime moderate and vigorous physical activity were observed (p<0.001), with larger decreases occurring in the older cohort. Associated increases were observed in sedentary time over time (p<0.01). Although the contribution of recess to daily moderate intensity physical activity increased in the younger cohort over time (p<0.001), significant decreases were observed in the older cohort (p<0.001).

Conclusion Physical activity levels during recess and lunchtime decreased in both cohorts over time. Decreases in the contribution of recess and lunchtime to older children's daily physical activity were also observed. Interventions are needed in both primary and secondary schools to promote physical activity levels during recess and lunchtime, particularly during the early years of secondary school.

Analysis of the contribution of reverse transcriptase and integrase proteins to retroviral RNA dimer conformation

All retroviruses contain two copies of genomic RNA that are linked noncovalently. The dimeric RNA of human immunodeficiency virus type 1 (HIV-1) undergoes rearrangement during virion maturation, whereby the dimeric RNA genome assumes a more stable conformation. Previously, we have shown that the packaging of the HIV-1 polymerase (Pol) proteins reverse transcriptase (RT) and integrase (IN) is essential for the generation of the mature RNA dimer conformation. Analysis of HIV-1 mutants that are defective in processing of Pol showed that these mutant virions contained altered dimeric RNA conformation, indicating that the mature RNA dimer conformation in HIV-1 requires the correct proteolytic processing of Pol. The HIV-1 Pol proteins are multimeric in their mature enzymatically active forms; RT forms a heterodimer, and IN appears to form a homotetramer. Using RT and IN multimerization defective mutants, we have found that dimeric RNA from these mutant virions has the same stability and conformation as wild-type RNA dimers, showing that the mature enzymatically active RT and IN proteins are dispensable for the generation of mature RNA dimer conformation. This also indicated that formation of the mature RNA dimer structure occurs prior to RT or IN maturation. We have also investigated the requirement of Pol for RNA dimerization in both Mason-Pfizer monkey virus (M-PMV) and Moloney murine leukemia virus (MoMuLV) and found that in contrast to HIV-1, Pol is dispensable for RNA dimer maturation in M-PMV and MoMuLV, demonstrating that the requirement of Pol in retroviral RNA dimer maturation is not conserved among all retroviruses.