Ozone induces glucose intolerance and systemic metabolic effects in young and aged brown Norway rats

Air pollutants have been associated with increased diabetes in humans. We hypothesized that ozone would impair glucose homeostasis by altering insulin signaling and/or endoplasmic reticular (ER) stress in young and aged rats. One, 4, 12, and 24 month old Brown Norway (BN) rats were exposed to air or ozone, 0.25 or 1.0 ppm, 6 h/day for 2 days (acute) or 2 d/week for 13 weeks (subchronic). Additionally, 4 month old rats were exposed to air or 1.0 ppm ozone, 6 h/day for 1 or 2 days (time-course). Glucose tolerance tests (GTT) were performed immediately after exposure. Serum and tissue biomarkers were analyzed 18 h after final ozone for acute and subchronic studies, and immediately after each day of exposure in the time-course study. Age-related glucose intolerance and increases in metabolic biomarkers were apparent at baseline. Acute ozone caused hyperglycemia and glucose intolerance in rats of all ages. Ozone-induced glucose intolerance was reduced in rats exposed for 13 weeks. Acute, but not subchronic ozone increased α2-macroglobulin, adiponectin and osteopontin. Time-course analysis indicated glucose intolerance at days 1 and 2 (2> 1), and a recovery 18 h post ozone. Leptin increased day 1 and epinephrine at all times after ozone. Ozone tended to decrease phosphorylated insulin receptor substrate-1 in liver and adipose tissues. ER stress appeared to be the consequence of ozone induced acute metabolic impairment since transcriptional markers of ER stress increased only after 2 days of ozone. In conclusion, acute ozone exposure induces marked systemic metabolic impairments in BN rats of all ages, likely through sympathetic stimulation

Evaluating HIV/STD interventions in developing countries: do current indicators do justice to advances in intervention approaches?

HIV continues to spread unabated in many developing countries. Here we consider the interventions that are currently in place and critically discuss the methods that are being used to evaluate them as reported in the published literature. In recent years there has been a move away from highly individual-oriented interventions towards more participatory approaches that emphasise techniques such as community-led peer education and group discussions. However, this move towards more community orientated intervention techniques has not been matched by the development of evaluation methods with which to capture and explain the community and social changes which are often necessary preconditions for health-enhancing behaviour change. Evaluation research continues to rely on quantitative methodologies that fail to elucidate the complex changes that the newer interventions seek to promote within target communities. In addition, these methods of evaluation tend to rely on the use of highly individualistic and quantitative biomedical indicators such as HIV/STD rates, or knowledge, attitude, perception and behaviour (KAPB) survey questionnaires. We argue that such approaches are inadequate for the task of tracking and measuring important determinants of programme success such as psycho-social changes, features of the community-intervention interface and the degree of trust and identification with which members of target communities regard particular interventions. Rigorously conducted qualitative process evaluations taking account of the above factors could make a key contribution to the development of more successful HIV-prevention interventions