The health effects of particulate air pollution - a Christchurch perspective

Air quality in Christchurch has been debated widely over the last 30 years and at present there is a Draft Plan from the Canterbury Regional Council which has the main aim of improving air quality in the region. It has been shown in an inventory of emissions, that the main source of particulate pollution in the city is the use of solid fuel domestic heating appliances such as open fires and wood burners. Pollution from road traffic is considered a significant contributor to other contaminants but is less that 10% for particulate. There is local evidence that during the winter months, when atmospheric inversion conditions occur, levels of PM₁₀ (particulate matter less than 10 µm in diameter) exceed local guidelines (50 mcg m^-3 -24 hr average) approximately 30 times each year. Research performed in Christchurch suggests that these levels of air pollution account for both premature mortality and an increase in symptoms and medication requirements in susceptible sub-groups such as those with chronic obstructive airways disease. Ongoing research is planned in Christchurch and a collaborative approach between public health physicians, biostatisticians, toxicologists and clinical researchers is likely to yield further useful information which will inform the decision-making process by the Canterbury Regional Council.     

Pharmacological and cardiovascular properties of a hydantoin derivative, BW 245 C, with high affinity and selectivity for PGD2 receptors

Initial experiments demonstrated that the hydantoin prostaglandin derivative, BW 245 C, has potent anti-aggregatory activity on human platelets which may result from its structural similarity with one of the natural prostaglandins. The aim of the present study was to extend this preliminary pharmacological characterization and to determine which, if any, prostaglandin receptor-type is responsible for mediating the biological activity of BW 245 C. A marked species variation was observed in the anti-aggregatory potency of BW 245 C such that in the human (0.36 X PGE1) it was about one hundred times more effective than in the rat (0.003 X PGE1). The relative potencies of PGI2 (ca. 10 X PGE1) and PGE1 were, however, similar in both species. An intravenous bolus injection of 250 micrograms/kg BW 245 C lowered systolic (-23%) and diastolic (-34%) blood pressure in spontaneously hypertensive rats. In radioligand binding studies it showed a high affinity and selectivity for PGD2 platelet receptors, binding to PGI2 or PGE2 receptors was not detectable. Therefore it is concluded that the platelet and cardiovascular actions of BW 245 C are mediated by PGD2 receptors and this accounts for the observed species variation which is a characteristic of this prostaglandin.