Time to hospital admission for acute stroke: an observational study

The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.Objectives: To determine the time from symptom onset to hospital admission of patients with suspected acute stroke, final diagnoses and patient eligibility for thrombolytic therapy. Design: Hospital-based, prospective, observational study. Setting: Royal Adelaide Hospital Stroke Unit, South Australia. Patients: All patients admitted to the unit with suspected acute stroke over 11 months (11 April to 10 October 2000 and 20 August 2001 to 19 January 2002). Main outcome measures: Time from symptom onset to admission; final diagnosis. Results: Of 284 patients admitted, 39 (14%) had diagnoses other than stroke (including eight with transient ischaemic attacks), 42 (15%) had haemorrhagic stroke and 203 (71%) had ischaemic stroke. Median time to admission after symptom onset was 6 hours (range, 30 min to 13 days), with 100 patients admitted within 3 hours of symptom onset (35%), and 80 within 2 hours (28%). Thirty-seven patients (13%) could have been considered for thrombolysis (diagnosis of non-severe but disabling ischaemic stroke and admission time < 3 hours). Location at stroke onset was the only independent predictor of time to admission. Conclusions: Most patients with stroke do not present urgently to the emergency department, rendering them less likely to be considered for thrombolytic therapy.Simon A Broadley and Philip D Thompso

Optimising the analysis of transcript data using high density oligonucleotide arrays and genomic DNA-based probe selection

Background: Affymetrix GeneChip arrays are widely used for transcriptomic studies in a diverse range of species. Each gene is represented on a GeneChip array by a probe-set, consisting of up to 16 probe-pairs. Signal intensities across probe-pairs within a probe-set vary in part due to different physical hybridisation characteristics of individual probes with their target labelled transcripts. We have previously developed a technique to study the transcriptomes of heterologous species based on hybridising genomic DNA (gDNA) to a GeneChip array designed for a different species, and subsequently using only those probes with good homology. Results: Here we have investigated the effects of hybridising homologous species gDNA to study the transcriptomes of species for which the arrays have been designed. Genomic DNA from Arabidopsis thaliana and rice (Oryza sativa) were hybridised to the Affymetrix Arabidopsis ATH1 and Rice Genome GeneChip arrays respectively. Probe selection based on gDNA hybridisation intensity increased the number of genes identified as significantly differentially expressed in two published studies of Arabidopsis development, and optimised the analysis of technical replicates obtained from pooled samples of RNA from rice. Conclusion: This mixed physical and bioinformatics approach can be used to optimise estimates of gene expression when using GeneChip arrays

The influence of style and origin on mineral composition of beers retailing in the UK

Beer has high nutritional values in terms of energy and is also a dietary source of antioxidants, carbohydrates and minerals among others. In Europe, 53 Mt of beer are produced annually, and with an average supply of 68.2 kg capita‾¹ year‾¹ among adults. In this study, the mineral composition of 125 commercial beer samples retailing in the UK, but originating from ten countries, was determined; such detailed information is lacking in UK food composition tables. Beer composition data are reported for Al, As, Ba, Ca, Cd, Co, Cr, Cs, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, Pb, Se, Sr, U, V and Zn, following analysis by inductively coupled plasma mass spectrometry. ANOVA results showed higher concentrations of Mo, Pb and Sr (0.160; 491.70 × 10‾⁵; 0.38 mg L‾¹, respectively) for stout/porter style and a significant higher amount of minerals such as Al (3.835 mg L−1), Cd (8.64 × 10−5 mg L‾¹), Mn (1.02 mg L‾¹) or Ni (0.312 mg L‾¹) among others for lambic beer. Regarding the country of origin, higher Se concentrations were reported from beer brewed in the USA (0.110 mg L‾¹). It is concluded that beer style was determined to have a greater effect on beer mineral composition than origin or container type

Evidence of neutral transcriptome evolution in plants

The transcriptome of an organism is its set of gene transcripts (mRNAs) at a defined spatial and temporal locus. Because gene expression is affected markedly by environmental and developmental perturbations, it is widely assumed that transcriptome divergence among taxa represents adaptive phenotypic selection. This assumption has been challenged by neutral theories which propose that stochastic processes drive transcriptome evolution. To test for evidence of neutral transcriptome evolution in plants, we quantified 18 494 gene transcripts in nonsenescent leaves of 14 taxa of Brassicaceae using robust cross-species transcriptomics which includes a two-step physical and in silicobased normalization procedure based on DNA similarity among taxa. Transcriptome divergence correlates positively with evolutionary distance between taxa and with variation in gene expression among samples. Results are similar for pseudogenes and chloroplast genes evolving at different rates. Remarkably, variation in transcript abundance among root-cell samples correlates positively with transcriptome divergence among root tissues and among taxa. Because neutral processes affect transcriptome evolution in plants, many differences in gene expression among or within taxa may be nonfunctional, reflecting ancestral plasticity and founder effects. Appropriate null models are required when comparing transcriptomes in space and time

Death receptor 3 regulates distinct pathological attributes of acute versus chronic murine allergic lung inflammation

The Death Receptor 3 (DR3)/Tumour Necrosis Factor-like cytokine 1A (TL1A) axis stimulates effector T cells and type 2 innate lymphocytes (ILC2) that trigger cytokine release and drive disease pathology in several inflammatory and autoimmune diseases, including murine models of acute allergic lung inflammation (ALI). The aim of this study was to elucidate the role of DR3 in chronic ALI compared to acute ALI, using mice genetically deficient in the DR3 gene (DR3ko). Results showed DR3 expression in the lungs of wild-type mice was up-regulated following induction of acute ALI and this increased expression was maintained in chronic disease. DR3ko mice were resistant to cellular accumulation within the alveolar passages in acute, but not chronic ALI. However, DR3ko mice displayed reduced immuno-histopathology and goblet cell hyperplasia; hallmarks of the asthmatic phenotype; in chronic, but not acute ALI. These data suggest DR3 is a potential therapeutic target, involved in temporally distinct aspects of ALI progression and pathogenesis

Immersion mode heterogeneous ice nucleation by an illite rich powder representative of atmospheric mineral dust

Atmospheric dust rich in illite is transported globally from arid regions and impacts cloud properties through the nucleation of ice. We present measurements of ice nucleation in water droplets containing known quantities of an illite rich powder under atmospherically relevant conditions. The illite rich powder used here, NX illite, has a similar mineralogical composition to atmospheric mineral dust sampled in remote locations, i.e. dust which has been subject to long range transport, cloud processing and sedimentation. Arizona Test Dust, which is used in other ice nucleation studies as a model atmospheric dust, has a significantly different mineralogical composition and we suggest that NX illite is a better surrogate of natural atmospheric dust. Using optical microscopy, heterogeneous nucleation in the immersion mode by NX illite was observed to occur dominantly between 246 K and the homogeneous freezing limit. In general, higher freezing temperatures were observed when larger surface areas of NX illite were present within the drops. Homogenous nucleation was observed to occur in droplets containing low surface areas of NX illite. We show that NX illite exhibits strong particle to particle variability in terms of ice nucleating ability, with ~1 in 105 particles dominating ice nucleation when high surface areas were present. In fact, this work suggests that the bulk of atmospheric mineral dust particles may be less efficient at nucleating ice than assumed in current model parameterisations. For droplets containing ≤2 × 10−6 cm2 of NX illite, freezing temperatures did not noticeably change when the cooling rate was varied by an order of magnitude. The data obtained during cooling experiments (surface area ≤2 × 10−6 cm2) is shown to be inconsistent with the single component stochastic model, but is well described by the singular model (ns(236.2 K ≤ T ≤ 247.5 K) = exp(6.53043 × 104− 8.2153088 × 102T + 3.446885376T2 − 4.822268 × 10−3T3). However, droplets continued to freeze when the temperature was held constant, which is inconsistent with the time independent singular model. We show that this apparent discrepancy can be resolved using a multiple component stochastic model in which it is assumed that there are many types of nucleation sites, each with a unique temperature dependent nucleation coefficient. Cooling rate independence can be achieved with this time dependent model if the nucleation rate coefficients increase very rapidly with decreasing temperature, thus reconciling our measurement of nucleation at constant temperature with the cooling rate independence

Soil-type influences human selenium status and underlies widespread selenium deficiency risks in Malawi

Selenium (Se) is an essential human micronutrient with critical roles in immune functioning and antioxidant defence. Estimates of dietary Se intakes and status are scarce for Africa although crop surveys indicate deficiency is probably widespread in Malawi. Here we show that Se deficiency is likely endemic in Malawi based on the Se status of adults consuming food from contrasting soil types. These data are consistent with food balance sheets and composition tables revealing that >80% of the Malawi population is at risk of dietary Se inadequacy. Risk of dietary Se inadequacy is >60% in seven other countries in Southern Africa, and 22% across Africa as a whole. Given that most Malawi soils cannot supply sufficient Se to crops for adequate human nutrition, the cost and benefits of interventions to alleviate Se deficiency should be determined; for example, Se-enriched nitrogen fertilisers could be adopted as in Finland

Analysis of ripening-related gene expression in papaya using an Arabidopsis-based microarray

Background Papaya (Carica papaya L.) is a commercially important crop that produces climacteric fruits with a soft and sweet pulp that contain a wide range of health promoting phytochemicals. Despite its importance, little is known about transcriptional modifications during papaya fruit ripening and their control. In this study we report the analysis of ripe papaya transcriptome by using a cross-species (XSpecies) microarray technique based on the phylogenetic proximity between papaya and Arabidopsis thaliana. Results Papaya transcriptome analyses resulted in the identification of 414 ripening-related genes with some having their expression validated by qPCR. The transcription profile was compared with that from ripening tomato and grape. There were many similarities between papaya and tomato especially with respect to the expression of genes encoding proteins involved in primary metabolism, regulation of transcription, biotic and abiotic stress and cell wall metabolism. XSpecies microarray data indicated that transcription factors (TFs) of the MADS-box, NAC and AP2/ERF gene families were involved in the control of papaya ripening and revealed that cell wall-related gene expression in papaya had similarities to the expression profiles seen in Arabidopsis during hypocotyl development. Conclusion The cross-species array experiment identified a ripening-related set of genes in papaya allowing the comparison of transcription control between papaya and other fruit bearing taxa during the ripening process

Root morphology and seed and leaf ionomic traits in a Brassica napus L. diversity panel show wide phenotypic variation and are characteristic of crop habit

Background: Mineral nutrient uptake and utilisation by plants are controlled by many traits relating to root morphology, ion transport, sequestration and translocation. The aims of this study were to determine the phenotypic diversity in root morphology and leaf and seed mineral composition of a polyploid crop species, Brassica napus L., and how these traits relate to crop habit. Traits were quantified in a diversity panel of up to 387 genotypes: 163 winter, 127 spring, and seven semiwinter oilseed rape (OSR) habits, 35 swede, 15 winter fodder, and 40 exotic/unspecified habits. Root traits of 14 d old seedlings were measured in a ‘pouch and wick’ system (n = ~24 replicates per genotype). The mineral composition of 3–6 rosette-stage leaves, and mature seeds, was determined on compost-grown plants from a designed experiment (n = 5) by inductively coupled plasma-mass spectrometry (ICP-MS). Results: Seed size explained a large proportion of the variation in root length. Winter OSR and fodder habits had longer primary and lateral roots than spring OSR habits, with generally lower mineral concentrations. A comparison of the ratios of elements in leaf and seed parts revealed differences in translocation processes between crop habits, including those likely to be associated with crop-selection for OSR seeds with lower sulphur-containing glucosinolates. Combining root, leaf and seed traits in a discriminant analysis provided the most accurate characterisation of crop habit, illustrating the interdependence of plant tissues. Conclusions: High-throughput morphological and composition phenotyping reveals complex interrelationships between mineral acquisition and accumulation linked to genetic control within and between crop types (habits) in B. napus. Despite its recent genetic ancestry (<10 ky), root morphology, and leaf and seed composition traits could potentially be used in crop improvement, if suitable markers can be identified and if these correspond with suitable agronomy and quality traits