The effects of the 2009 dust storm on emergency admissions to a hospital in Brisbane, Australia

In September 2009 an enormous dust storm swept across eastern Australia. Dust is potentially hazardous to health as it interferes with breathing, and previous dust storms have been linked to increased risks of asthma and even death. We examined whether the 2009 Australian dust storm changed the volume or characteristics of emergency admissions to hospital. We used an observational study design, using time series analyses to examine changes in the number of admissions, and case-only analyses to examine changes in the characteristics of admissions. The admission data were from the Prince Charles Hospital, Brisbane, between 1 January 2009 and 31 October 2009. There was a 39% increase in emergency admissions associated with the storm (95% confidence interval: 5, 81%), which lasted for just 1 day. The health effects of the storm could not be detected using particulate matter levels. We found no significant change in the characteristics of admissions during the storm; specifically, there was no increase in respiratory admissions. The dust storm had a short-lived impact on emergency hospital admissions. This may be because the public took effective avoidance measures, or because the dust was simply not toxic, being composed mainly of soil. Emergency departments should be prepared for a short-term increase in admissions during dust storms.     

Negative association between asthma and variants of CC16(CC10) on chromosome 11q13 in British and Japanese populations

The gene encoding Clara cell-derived inflammatory molecule CC16 has been cited as a candidate gene for atopic asthma on chromosome 11q13. A genetic association study was performed with variants of the CC16 gene on chromosome 11q13 in relation to asthma in British (n=275) and Japanese (n=300) populations. No significant association was found between asthma and CC16 genotypes, irrespective of atopic status in these two populations. These data suggest that CC16 might not be the major locus for asthma on 11q13. Received: 22 December 1997 / Accepted: 9 February 1998     

Seasonal waves of asthma: A possible botanical cause

The seasonal incidence of asthma and of shoot-growth in eucalypts in four Australian capital cities (Brisbane, Sydney, Adelaide and Melbourne) are compared. The incidence of asthma appears to be closely correlated with the initial stages of the seasonal flushes in shoot-growth of eucalypts, when rapid cell-division occurs. A spring to early summer growth flush invariably occurs in all capitals when the mean monthly temperature rises above 16–18°C; it is initiated progressively later with increasing latitude firstly in Brisbane, then in Sydney, then Adelaide and finally Melbourne. Although the correlation between asthma and eucalypt shoot-growth is high, there is not necessarily a cause-and-effect relationship. Volatile compounds evaporated from young and old leaves are probably not responsible, but the fine faecal pellets from the numerous small larvae and adult insects which attack the young eucalypt shoots may produce possible asthma-allergens. The concentration of these allergens in the atmosphere is reduced by heavy rainfall and by off-shore winds, and may accumulate during periods when temperature inversions occur at low levels in the atmosphere (e.g. during autumn in Brisbane).Supported by a grant from the Asthma Foundation of Queensland.     

Loss of test cells leads to the formation of new tunic surface cells and abnormal metamorphosis in larvae of Ciona intestinalis (Chordata, Ascidiacea)

The larvae of the ascidian Ciona intestinalis from which the chorion with the test cells and follicle cells were removed developed normally without the test cells until the early tailbud stage. A number of round-shaped cells morphologically similar to the test cells but with different lectin affinities and autofluorescence, then appeared on the neck region of the demembranated embryos. The new cells had three different types: round, particulate, and granular, and these cells increased in number after the late tailbud stage. The morphology of the adhesive papillae, tunic layers and epidermis of the demembranated larvae was similar to that of control larvae; however, the affinity to lectins was different in the swimming period. Control larvae attached to the substratum after the swimming period, resorbed the tail completely and underwent rotation of the visceral organs. Conversely, rotation occurred before completion of tail resorption in the demembranated larvae. Furthermore, the metamorphic events progressed more slowly in the demembranated larvae. These results suggest that the test cells play important roles in normal development and morphogenesis of ascidian larvae. Received: 4 December 1998 / Accepted: 9 April 1999     

Growth Rates of Marine Bacterial Isolates on Particulate Organic Substrates Solubilized by Freely Released Extracellular Enzymes

Abstract Growth rates of marine bacterial isolates on particulate organic substrates were measured using a novel apparatus which restricts bacterial cells to the uptake of hydrolysate produced from particulate substrates only by enzymes that are actively released from the bacterium into the culture medium. Significant, varying growth rates were measured for four different marine bacteria, using three different, ecologically significant particulate organic substrates (preparations of amylopectin, chitin, and animal hide). Growth rates sometimes approached but were usually lower than rates that have been reported in laboratory experiments using dissolved organic growth substrates. These results are consistent with recent model predictions and have important implications for microbial ecology and material cycling in diverse liquid-bathed environments. Received: 26 June 1998; Accepted: 20 October 1998     

Winter water relations of timberline larch (Larix leptolepis Gord.) on Mt. Fuji

 A krummholz mat of larch, Larix leptolepis, is the predominant growth form near the upper limit (near 2500 m) of the timberline ecotone on the south slope of Mt. Fuji, Japan. On the south-eastern slope, the tree line is lowered to 1600 m because of the last volcanic eruption. The extent and causes of winter desiccation were compared in timberline larch between 2500 m and 1600 m elevation over two winters. Bark abrasion due to wind-blown fine volcanic gravels caused a decrease in bark resistance to water loss and resulted in severe desiccation damage to current-year shoots of krummholz larches in the winter of 1986 – 87 at 2500 m, whereas abraded shoots at 1600 m maintained high water content during both winters. In the winter of 1985 – 86, shoots of krummholz larches at 2500 m did not experience bark abrasion and high water contents were maintained. Experimental abrasion of shoot surfaces resulted in similar results at each elevation. Thus, in timberline larch at 2500 m, abrasion by wind-blown fine volcanic gravels is the primary factor causing winter desiccation damage and krummholz formation. Based on field experiments, the estimated amount of water movement to non-abraded shoots was the same for the two elevations. At 2500 m, water movement to abraded shoots was less than to non-abraded shoots, but the reverse situation was noted at 1600 m. Water supply to abraded shoots at 2500 m was limited and insufficient to compensate for water loss. A cause of limited water supply at 2500 m may be xylem embolism. Received: 13 January 1995 / Accepted: 31 January 1996     

Synonymous and Nonsynonymous Substitution Rates in Diatoms: A Comparison Between Chloroplast and Nuclear Genes

Rates of synonymous and nonsynonymous nucleotide substitutions and codon usage bias (ENC) were estimated for a number of nuclear and chloroplast genes in a sample of centric and pennate diatoms. The results suggest that DNA evolution has taken place, on an average, at a slower rate in the chloroplast genes than in the nuclear genes: a rate variation pattern similar to that observed in land plants. Synonymous substitution rates in the chloroplast genes show a negative association with the degree of codon usage bias, suggesting that genes with a higher degree of codon usage bias have evolved at a slower rate. While this relationship has been shown in both prokaryotes and multicellular eukaryotes, it has not been demonstrated before in diatoms. Received: 3 June 1998 / Accepted: 11 August 1998     

Anti-Inflammatory and Anti-Remodelling Potential of Ethanol Extract Rhodomyrtus Tomentosa in Combination of Asthma and Coal Dust Models

Background:Combination of asthma and coal dust is a chronic and recurring airway disease related to inflammation cell activation. The Rhodomyrtus tomentosa flowering plants native to South Kalimantan exhibit a broad therapeutic potential, like anti-inflammatory and anti-remodelling properties. This study aims to analyze the effect of ethanol extract of R. tomentosa leaves (EERTL) nebulizer on the number of inflammatory cells and histomorphometry of lung tissue in a mice-like model of a combination of asthma and coal dust.Methods:The 24 BALB/c mice were divided into four treatment groups (n= 6 per group), were sensitized with normal saline (K), OVA + coal dust (P1), OVA + coal dust + salbutamol (P2), and OVA + coal dust + EERTL (P3). Eosinophil cells, neutrophils, lymphocytes, epithelial thickness, smooth muscle, fibrosis subepithelial bronchioles, and the number of goblet cells as indicators of anti-inflammatory and anti-remodelling airways.Results:The number of eosinophils, neutrophils, and lymphocytes cells are given salbutamol or EERTL was significantly lower than the OVA-sensitized and coal dust exposure group only. There are meaningful differences in the average thickness of the epithelium, smooth muscle, and subepithelial fibrosis of bronchiolus. The histopathology picture of goblet cells showed an increase in the number and size (hyperplasia) in OVA-sensitized and coal dust exposure compared to another group.Conclusion:It was concluded that the EERTL nebulizer could reduce inflammatory cells and remodelling process from bronchoalveolar lavage in the mice combination of asthma and coal dust models.Key Words: Anti-Inflammatory, Anti-Remodelling, Asthma, Coal Dust, Rhodomyrtus tomentosa     

Sexual and apomictic development in Hieracium

 Most members of the genus Hieracium are apomictic and set seed without fertilization, but sexual forms also exist. A cytological study was conducted on an apomictic accession of H. aurantiacum (A3.4) and also H. piloselloides (D3) to precisely define the cellular basis for apomixis. The apomictic events were compared with the sexual events in a self-incompatible isolate of H. pilosella (P4). All plants were maintained as vegetatively propagated lines each derived from a single plant. Sexual P4 exhibited characteristic events of polygonum-type embryo sac formation, showed no latent apomitic tendencies, and depended upon fertilization to set seed. In contrast, D3 and A3.4 were autonomous aposporous apomicts, forming both embryo and endosperm spontaneously inside an unreduced embryo sac. The two apomicts exhibited distinct mechanisms, but variation was also observed within each apomictic line. Seeds from apomicts often contained more than one embryo. A degree of developmental instability was also observed amongst germinated seedlings and included variation in meristem and cotyledon number, altered phyllotaxis, callus formation, and seedling fusion. In most cases abnormal seedlings developed into normal plants. Such phenomena were not observed following germination of hybrid seeds derived from crosses between sexual P4 and the apomictic plants. The three plants can now be used in inheritance studies and also to investigate the molecular mechanisms controlling apomixis. Received: 11 February 1998 / Revision accepted: 23 July 1998     

Effect of particulate pollution on rate of transpiration in Shorea robusta at Lalpahari forest

The effect of stone dust deposition on the rate of transpiration in Shorea robusta was studied in three principal seasons in a polluted forest in comparison to an almost non-polluted forest. The extent of particulate pollution was determined by measuring suspended particulate matter in the air and dust fall on leaf surface. Macroscopic and microscopic leaf injury symptoms were studied. Scanning electron microscopic examination of leaf surfaces revealed a number of foliar anomalies. Qualitative determination of rate of transpiration in field condition was done by ‘cobalt chloride method’. It was found that transpiration was diminished as a result of foliar dust deposition which not only caused blockage of stomatal aperture but also physical damage to the leaf surface. Thus, particulate air pollution can be considered as one of the external factors regulating the rate of transpiration in plants.     

The vector competence of Culex annulirostris, Aedes sagax and Aedes alboannulatus for Murray Valley encephalitis virus at different temperatures

Culex annulirostris Skuse, colonized from Brisbane, Queensland, and Mildura, Victoria, Australia, were effective vectors of Murray Valley encephalitis virus at 20, 27 and 32-35 degrees C with full extrinsic incubation periods of 15, 10 and 4 days respectively. At 20 degrees C, 7-11 days post-infection, transmission by the Mildura colony (0-20%) was less efficient than the Brisbane colony (30-70%) but both were capable of 75-100% transmission after longer extrinsic incubation periods. Discriminant analysis of body and salivary gland titres showed that these were not satisfactory indicators of transmission. Wild-caught Aedes sagax (Skuse) and Cx annulirostris from the Murray Valley showed equal competence, but Aedes alboannulatus (Macquart) was a poor vector. The results provide data on rural amplification of Murray Valley encephalitis virus during spring and suggest that further work on the potential of Ae. sagax as a natural vector is warranted.     

Measurement of resuspended aerosol in the Chernobyl area

During anthropogenic activities, such as agricultural soil management and traffic on unpaved roads, size distribution measurements were performed of atmospheric particulate radionuclides at a site in the Chernobyl 30-km exclusion zone. Analysis of cascade impactor measurements showed an increase of the total atmospheric radioactivity. In the cases of harrowing by a tractor and traffic on unpaved roads, a common shape of the size distribution was found with two maxima, the first in the 2–4 μm range, the second in the 12–20 μm range. The size distributions were compared to measurements during wind-driven resuspension. Particle number concentration measurements with an Aerodynamic Particle Sizer showed a dynamic dependence of the particle concentration in different size ranges on anthropogenic action. The increase of the mean concentration was for the large particles more than one order of magnitude higher than for fine particles during anthropogenic enhanced resuspension. From the measurement of the mass concentration, the radioactive loading could be estimated. An enrichment of radionuclides on resuspended particles (compared to soil particles) was found, with the highest enrichment for large particles. Micrometeorological considerations showed that large particles may frequently be subject to medium range transport. The dry deposition velocity was measured; the mean value of 0.026 m s^–1±0.016 m s^–1 is typical for 6–9 μm diameter particles. Received: 17 February 1998 / Accepted in revised form: 17 June 1998     

Effects of yeast extract on the production and the quality of the exopolysaccharide, zooglan, produced by Zoogloea ramigera 115SLR

Although many studies have examined the influence of culture conditions on the production and composition of polysaccharides, little is known about the factors influencing the quality of exopolysaccharides (EPS). In this work we studied the effect of yeast extract on the production, composition and molecular weight of the EPS zooglan produced by Zoogloea ramigera 115SLR. This bacterium was grown on a new completely defined synthetic medium and on a medium containing yeast extract. Growth and polysaccharide production performances were comparable on the two media with a glucose to exopolysaccharide conversion yield of 35% (g/g). The polysaccharides produced on these two media have an identical composition but a different molecular weight and molecular weight distribution. The yeast extract medium leads to a more homogeneous polysaccharide solution. Received: 12 June 1998 / Received revision: 19 September 1998 / Accepted: 11 October 1998     

Grain dust and the lungs.

Grain dust is composed of a large number of materials, including various types of grain and their disintegration products, silica, fungi, insects and mites. The clinical syndromes described in relation to exposure to grain dust are chronic bronchitis, grain dust asthma, extrinsic allergic alveolitis, grain fever and silo-filler''s lung. Rhinitis and conjunctivitis are also common in grain workers. While the concentration and the quality of dust influence the frequency and the type of clinical syndrome in grain workers, host factors are also important. Of the latter, smoking is the most important factor influencing the frequency of chronic bronchitis. The role of atopy and of bronchial hyperreactivity in grain dust asthma has yet to be assessed. Several well designed studies are currently being carried out in North America not only to delineate the frequency of the respiratory abnormalities, the pathogenetic mechanisms and the host factors, but also to establish a meaningful threshold limit concentration for grain dust.     

Evolution of Microsatellites in the Yeast Saccharomyces cerevisiae: Role of Length and Number of Repeated Units

The observed and expected frequencies of occurrence of microsatellites in the yeast Saccharomyces cerevisiae were investigated. In all cases, the observed frequencies exceeded the expected ones. In contrast to predictions by Messier et al. (1996), there is no critical number of repeats beyond which the observed frequencies of microsatellites significantly exceed the frequencies expected in a random DNA sequence of the same size. Rather, the degree of deviation from expectation was found to be dependent on the length of the microsatellite. That is, a fourfold concatemeric repeat of 3 bp was found to deviate from expectation as much as threefold concatemeric repeat of 4 bp, unlike the deviation of a fourfold concatemeric repeat of 4 bp. These findings suggest that microsatellites evolve through strand-slippage events, rather than recombination events. This, in turn, suggests that the chances of erroneous hybridizations leading to strand-slippage are length dependent. Received: 1 June 1998 / Accepted: 16 September 1998     

Capsule formation in Zymomonas mobilis grown on sucrose

A capsule formed around Zymomonas mobilis grown on sucrose, increasing in thickness with higher initial sucrose concentrations. Cryofixation and freeze-substitution electron microscopy techniques preserved this polymer matrix, unlike other techniques.L.A. Kirk and R.i. Webb are with the Department of Microbiology, The University of Queensland, Brisbane, Qld 4072, Australia; R.I. Webb is also with the Centre for Microscopy and Microanalysis and H.W. Doelle is with MIRCEN-Brisbane, both at The University of Queensland, Brisbane, Qld 4072, Australia.     

Allergen exposure and control

Allergens produced by the house dust mites (family Pyroglyphidae) are probably the single most important allergens associated with asthma world wide. If exposure to these allergens in houses could be sufficiently reduced, then asthma symptoms may be markedly reduced and even prevented from being initiated. Only about half of the many attempts to reduce mite allergens in houses have shown any clinical benefit. One reason may be that exposure was not reduced enough-however exposure to mite allergens has never been measured in any trial. This review summarises previous allergen control trials and then provides an outline of allergen exposure, including the nature of exposure, the analytical methods available and the recognised risks of allergen exposure. This provides a perspective to evaluate the individual methods used to kill mites and to reduce exposure to the allergens. The object is to provide a framework to improve and develop allergen avoidance as an effective component of asthma management.The author is supported by a project grant from the National Heath and Medical Research Council of Australia.     

Adaptive strategies in natural populations of Drosophila

Summary Adult tolerance of ethanol vapour in a closed system containing 12% ethanol in solution, decreases in a cline from southern to northern Australia. However a Darwin population is more tolerant than predicted from its latitude. Ethanol tolerance races in Australia have almost certainly evolved within the last 100–150 years, because of resource unavailability prior to that time. Within populations, variation among isofemale strains is lowest in the climatically extreme southern Melbourne (37°S) and northern Darwin and Melville I. (11–12°S) populations. This suggests low resource diversity within extreme populations compared with the climatically less extreme Brisbane (28°S) and especially Townsville (19°S) populations. For desiccation resistance, the population rankings are: Darwin Melbourne > Townsville > Brisbane Melville I. and for development time, rankings are similar: Darwin Melbourne < Townsville < Brisbane Melville I.Therefore resource utilization heterogeneity is greatest in populations not greatly stressed by desiccation and where development times are extended. In total therefore, the utilization of a diversity of resources is a feature of populations tending somewhat towards a K-strategy; this is emphasized by the relative heterogeneity among isofemale strains of these populations for desiccation resistance and to a lesser extent development times.The D. melanogaster gene pool can be viewed as made up of climate-associated races. Since the ethanol tolerances of adjacent (and climatically similar) Darwin and Melville I. are very different, resource utilization races may occur within climatic races. Such a mosaic of resource utilization races are more likely in climatically extreme than in optimal habitats.     

Overexpression of phytochrome A enhances the light-induced formation of adventitious shoots on horseradish hairy roots

A full-length cDNA of the gene for phytochrome A from Arabidopsis thaliana was fused with the 35S promoter of cauliflower mosaic virus (CaMV35S-PHYA) and introduced into horseradish (Armoracia rusticana Gaert., Mey. et Scherb.) hairy roots. The phytochrome level in hairy roots transformed with CaMV35SPHYA was about three times greater than that in normal hairy roots and the rate of light-induced formation of adventitious shoots was also higher in the hairy roots transformed with CaMV35SPHYA. These results indicate that the light-induced formation of adventitious shoots on horseradish hairy roots is closely related to the phytochrome level. Received: 11 August 1998 / Revision received: 21 October 1998 / Accepted: 20 November 1998     

Extracellular laccase production during hyphal interactions between Trichoderma sp. and Shiitake, Lentinula edodes

Lentinula edodes (Berk.) Pegler was cultivated in liquid media containing malt and yeast extract. Extracellular laccase activity, measured in the culture fluids, was 5–18 times higher in cultures incubated for 29 days than in cultures incubated for 24 days. The addition of water-soluble lignin derivatives or Trichoderma sp. in cultures of L. edodes incubated for 11 days increased laccase activity 3- to 20 fold. The higher response was obtained with live mycelium of Trichoderma sp., but cell-free culture fluids of Trichoderma sp. in pure cultures were also effective. Trichoderma sp. induced changes in the laccase isoenzyme pattern as a result of the alteration of laccases secreted by L. edodes and not the induction of new isoforms. Received: 3 November 1997 /  Received revision: 19 January 1998 /  Accepted: 24 January 1998