BackgroundThere are many communities around the world that are exposed to high levels of particulate matter <10 µm (PM10) of geogenic (earth derived) origin. Mineral dusts in the occupational setting are associated with poor lung health, however very little is known about the impact of heterogeneous community derived particles. We have preliminary evidence to suggest that the concentration of iron (Fe) may be associated with the lung inflammatory response to geogenic PM10. We aimed to determine which physico-chemical characteristics of community sampled geogenic PM10 are associated with adverse lung responses.MethodsWe collected geogenic PM10 from four towns in the arid regions of Western Australia. Adult female BALB/c mice were exposed to 100 µg of particles and assessed for inflammatory and lung function responses 6 hours, 24 hours and 7 days post-exposure. We assessed the physico-chemical characteristics of the particles and correlated these with lung outcomes in the mice using principal components analysis and multivariate linear regression.ResultsGeogenic particles induced an acute inflammatory response that peaked 6 hours post-exposure and a deficit in lung mechanics 7 days post-exposure. This deficit in lung mechanics was positively associated with the concentration of Fe and particle size variability and inversely associated with the concentration of Si.ConclusionsThe lung response to geogenic PM10 is complex and highly dependent on the physico-chemical characteristics of the particles. In particular, the concentration of Fe in the particles may be a key indicator of the potential population health consequences for inhaling geogenic PM10.
A biosensor system was developed to measure progesterone levels in the urine of female numbats (Myrmecobius fasciata) as an index of ovarian function. Screen printed sensors were coated with a monoclonal progesterone antibody, and incubated in a mixture of sample/standard and progesterone-3-CMO-horseradish peroxidase (HRP). The difference in potential between the working and reference electrode was measured, after exposure to an HRP substrate. EIA and biosensor standard curves showed parallelism, and the biosensor gave values similar (r = 0.83) to the conventional EIA. Progesterone concentrations at different stages of the oestrus cycle were not significantly different to those obtained by EIA.
A biosensor system using screen printed sensors was developed to measure progesterone as an index of ovarian function, and compared with a standard enzymeimmunoassay (EIA). The sensors were coated with a monoclonal progesterone antibody which cross-reacts with a wide range of progestogens, and incubated in a mixture of sample/standard and progesterone-3-CMO-horseradish peroxidise (Prog/HRP). The endpoint was the change in potential read following the addition of sodium perborate. The assay was optimised in terms of the Prog/HRP concentration, the antibody dilution and incubation times. It was then used to measure progestogen in the urine of five female Numbats (Myrmecobius fasciata). Results were available using the sensors within 20 min compared with the standard EIA protocol of 2 h. The serial dilution of a urine sample taken at the diestrus stage showed parallelism with the serially diluted standard. There was a significant rise in progesterone (mean ± sem) after mating compared with that seen before for both the EIA (1.31 ± 0.20 to 3.70 ± 0.13 ng/mL) and the sensor (1.83 ± 0.33 to 4.02 ± 0.61 ng/mL), and there were no significant differences between the sensor and EIA results at either stage (all P > 0.1). A comparison of the values obtained with the sensors to those obtained with the conventional EIA showed a significant correlation for each of the animals (r = 0.82 to 0.99). It is concluded that the biosensor system is a viable alternative to conventional EIA, and provides the advantage of (a) a shorter assay time and (b) greater potential for use in the field.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.