Re-aerosolization of Bacillus thuringiensis spores from concrete and turf.

Spores of Bacillus anthracis deposited on surfaces can become airborne again as a result of air currents and mechanical forces. As such, they are a potential source of infection by inhalation. Spores of Bacillus thuringiensis were used to quantify this phenomenon in a simulation of outdoor conditions. Concrete and turf surfaces were inoculated by aerosol to produce high spore densities (greater than 1 × 109  CFU per m2 ) which were then subjected to the passage of air at 10 ms-1 with and without simulated walking. Re-aerosolized spores were sampled by wetted wall cyclone air samplers. The mean total re-aerosolization rate from concrete (m-2  min-1 ) was 1·16 × 10-3 for wind alone and 3·2 × 10-3 for wind and simulated walking while for turf the respective values were 2·7 × 10-4 and 6·7 × 10-4 . SIGNIFICANCE AND IMPACT OF THE STUDY: Following the malicious and/or accidental release of an aerosol of Bacillus anthracis spores, the immediate risk of human inhalation would decrease as the spores were deposited on surfaces or diluted by wind flow. There is, however, a concern that the deposited spores could become re-aerosolized and so present an ongoing hazard. Using an accurate simulant for B. anthracis spores a method is reported here that allowed the enumeration of re-aerosolized spores from concrete and turf by wind flow and footfall. Under the conditions used, the rates of re-aerosolization were low. These findings will need to be verified under real outdoor conditions before the true significance in terms of secondary exposure to pathogenic spores can be assessed.

A novel MHC class I-like gene is mutated in patients with hereditary haemochromatosis.

Hereditary haemochromatosis (HH), which affects some 1 in 400 and has an estimated carrier frequency of 1 in 10 individuals of Northern European descent, results in multi-organ dysfunction caused by increased iron deposition, and is treatable if detected early. Using linkage-disequilibrium and full haplotype analysis, we have identified a 250-kilobase region more than 3 megabases telomeric of the major histocompatibility complex (MHC) that is identical-by-descent in 85% of patient chromosomes. Within this region, we have identified a gene related to the MHC class I family, termed HLA-H, containing two missense alterations. One of these is predicted to inactivate this class of proteins and was found homozygous in 83% of 178 patients. A role of this gene in haemochromatosis is supported by the frequency and nature of the major mutation and prior studies implicating MHC class I-like proteins in iron metabolism.

Investigations into the source of two fungicides measured in the air for 24 hours following application to a cereal crop.

Airborne pesticides can be detected near to recently-treated arable fields for a period of days following the application. Identifying the source of such pesticides is important in developing predictive models for use in exposure and risk assessments. Previous work showed levels of pesticide in the air that were higher than expected for a low-vapour-pressure active ingredient, epoxiconazole, and comparable with an active ingredient of a significantly higher vapour pressure, fenpropidin. It was possible that the measured concentrations could be attributed to 'dust' particles emitted from the crop, either biological material contaminated with pesticide or solid dried deposits of active ingredient and other formulation components. A second experiment was therefore undertaken to measure airborne concentrations of the same active ingredients and to determine whether some or all of the measured airborne pesticide could be attributed to particles, using a Marple personal cascade impactor, which collects particles in the range 0.3 - 50 microm. Such samplers are not optimised to give good sampling efficiencies under the proposed field conditions, so some initial tests were undertaken in the Silsoe wind tunnel to assess its ability to sample particles in an air flow. In the subsequent field trial, a 192 m square plot in a commercially established winter cereal crop was sprayed with a tank mix of commercial formulations of epoxiconazole and fenpropidin. Measurements of airborne pesticides were made for 24 hours following the application with suction samplers attached to tenax tubes to evaluate vapour concentrations and with the cascade impactor to determine whether contaminated airborne particles were present. The concentrations of pesticide measured with the tenax tubes were significantly higher than the particulate component detected on the cascade impactor plates and it is therefore it was very unlikely that there was a significant contribution from pesticide-laden particles to the airborne concentration. Although it is clear that under these particular experimental conditions, airborne contaminated particles were not detected in significant quantities after the application, it is possible that this could occur under different circumstances, such as during pollen release or harvest.

Modelling exposure of workers, residents and bystanders to vapour of plant protection products after application to crops.

Agricultural use of plant protection products can result in exposure of bystanders, residents, operators and workers. Within the European Union (EU) FP7 project BROWSE, a tool based on a set of models and scenarios has been developed, aiming to assess the risk of exposure of humans to these products. In the present version of the tool only a first conservative tier is available for outdoor vapour exposure assessment. In the vapour exposure evaluation, the target concentrations in air at 10m distance from the edge of a treated field are calculated for specific scenarios for each EU regulatory zone. These scenarios have been selected to represent reasonable worst case volatilisation conditions. The exposure assessment is based on a series of weekly applications in a five year period to cover a wide range of meteorological conditions. The volatilisation from the crop is calculated using the PEARL model and this PEARL output provides the emission strength used as input for the short term version of the atmospheric transport model OPS. The combined PEARL-OPS model is tested against measurements from a field experiment. First results of this test show that the mean concentration level was predicted fairly well. However, sometimes the differences between observations and simulations were found to be substantial. Improvements are suggested for the vapour exposure scenarios as well as for further model development. In the current version of the BROWSE tool a simplified procedure is used to assess single and multiple applications. The actual period of application and the time of application during the day are fixed, and the growth stage of the crop cannot be taken into account. Moreover, competing processes such as penetration of the substance into the plant tissue are not considered. The effect of these factors on the target exposure concentrations is discussed.

Perceptions of pesticides exposure risks by operators, workers, residents and bystanders in Greece, Italy and the UK.

The EU Directive on the sustainable use of pesticides (EU128/2009/EC) requires European Member States to develop training activities targeting occupational exposure to pesticides, and communication material aimed at residents and bystanders. Risk perceptions, knowledge and attitudes associated with passive and occupational exposure to pesticide potentially influence the extent to which different stakeholders adopt self-protective behaviour. A methodology for assessing the link between attitudes, adoption of self-protective behaviours and exposure was developed and tested. A survey was implemented in the Greece, Italy and the UK, and targeted stakeholders associated with pesticide exposure linked to orchards, greenhouse crops and arable crops respectively. The results indicated that the adoption of protective measures is low for residents and bystanders, with the exception of residents in Greece, when compared to operators and workers, who tend to follow recommended safety practices. A regression analysis was used to examine the factors affecting the probability of adopting protective measures as well the as the level of exposure in the case of operators and workers where data are available. The results indicate that the likelihood of engaging in self-protective behaviour is not significantly affected by perceptions of own health being affected by pesticides for residents and bystanders. However, operators who perceive that their heath has been negatively affected by the use of pesticides are found to be more likely to adopt self-protective behaviours. Gender and country differences, in perceptions, attitudes and self-protection are also observed. Recommendations for improved communication, in particular for vulnerable groups, are provided.

Identification of metabolites of [1,2,3-(13)C]Propargyl alcohol in rat urine by (13)C NMR and mass spectrometry.

Little is known about the metabolism of acetylenic (C&tbd1;C) compounds commonly used in the formulation of pesticides. To better understand the in vivo reactivity of this bond, we examined the metabolism of propargyl alcohol (PA), 2-propyn-1-ol, used extensively in the chemical industry. [1,2,3-(13)C, 2,3-(14)C]PA was administered orally to male Sprague-Dawley rats. Approximately 56% of the dose was excreted in urine by 96 h. Major metabolites were characterized, directly, in the whole urine by one- and two-dimensional (13)C NMR. To determine the complete structures of metabolites of PA, rat urine was also subjected to TLC followed by purification of separated TLC bands on HPLC. The purified metabolites were identified by (13)C NMR and mass spectrometry and by comparison with available synthetic standards. The proposed metabolic pathway involves oxidation of propargyl alcohol to 2-propynoic acid and further detoxification via glutathione conjugation to yield as final products: 3, 3-bis[(2-(acetylamino)-2-carboxyethyl)thio]-1-propanol, 3-(carboxymethylthio)-2-propenoic acid, 3-(methylsulfinyl)-2-(methylthio)-2-propenoic acid, 3-[[2-(acetylamino)-2-carboxyethyl]thio]-3-[(2-amino-2-carboxyethyl)t hio]-1-propanol and 3-[[2-(acetylamino)-2-carboxyethyl]sulfinyl]-3-[2-(acetylamino)-2-car boxyethyl]thio]-1-propanol. These unique metabolites have not been reported previously and represent the first example of multiple glutathione additions to the carbon-carbon triple bond.

Procedures used to prepare and administer intramuscular injections: a study of infertility nurses.

OBJECTIVE: To describe the procedures infertility nurses use to prepare and administer intramuscular injections of fertility medications. DESIGN: Descriptive survey. PARTICIPANTS: Nurses listed as members of the Nurses Professional Group of the American Society for Reproductive Medicine (N = 645) were surveyed. Completed questionnaires were returned by 219 of the nurses. MAIN OUTCOME MEASURES: Volume of diluent, needle selection, site selection, internal rotation of the extremity distal to the injection site, and use of the z-track technique. RESULTS: There was wide variation in the gauge and length of needles used to administer the medications, with most nurses using a 22 g, 1-1/2-in needle for all medications. Most nurses changed the needle between preparing and administering medications; however, filter needles were seldom used. There was wide variation in the volume of diluent used to reconstitute medications. Most of the nurses used the dorsogluteal site for injections. Although almost all of the nurses indicated that they routinely rotated injection sites, they infrequently used sites other that the dorsogluteal site. Most nurses did not rotate the extremity distal to the injection site when administering injections and even fewer used the z-track technique. CONCLUSIONS: This study demonstrated wide variation in the procedures used by infertility nurses to prepare and administer intramuscular injections of fertility medications. Many nurses did not use procedures that can reduce the pain and tissue trauma associated with intramuscular injections.

Unusual causes for abnormal hepatobiliary scans.

Cholescintigraphy with Tc-99m iminodiacetic acid (IDA) agents has proved to be a convenient, non-invasive method for evaluating patients with suspected cholecystitis. (1,2) We recently examined two patients who were being evaluated for abdominal pain. The etiology of the two abnormal cholescintigrams was later proven to be due to nonhepatobiliary pathology.

Field dependence-independence and the discrimination of musical parts.

The association of the cognitive style known as field dependence-independence and 168 subjects correct detection of the number of parts in 24 musical items was investigated. Each item was arranged in one of three textures. With the effects of general mental ability, experience in music, and gender held constant, scores on the Group Embedded Figures Test explained significant variance in discrimination (7.5%). Factorial analysis showed significant main effects for cognitive-style groups, number of parts, and texture. The interaction between the effects of part and texture was also significant. In some cases an individual's cognitive style may influence perception of "what's going on" in music.

Confrontation of scabrous expressing and non-expressing cells is essential for normal ommatidial spacing in the Drosophila eye.

The establishment of neural precursor cells in Drosophila depends on cell-cell interactions and lateral inhibition. Scabrous (sca) is involved in this process by preventing an excess of cells from adopting a neural precursor fate. Specifically in eye development, Sca protein function has been implicated in the spacing pattern that is essential for the ordered appearance of the ommatidial array. During this process sca expression is restricted to neurogenic groups of cells and later to the neural precursors. We report that ectopic sca expression in the morphogenetic furrow results in a rough eye phenotype with oversized and fused ommatidia. These defects in adult eyes are due to the generation of too many ommatidial preclusters in the morphogenetic furrow. Strikingly, sca loss-of-function mutants have an almost identical phenotype. Our results suggest that Sca plays a positive role in establishing the spacing pattern within the furrow and that the quantitative difference in sca expression between neighboring groups of cells is a determining factor in this process. Ectopic expression of Sca also represses endogenous sca expression in the furrow, suggesting that Sca is involved in a feedback loop affecting its own transcription. Interestingly, sca shares homology to a group of extracellular matrix proteins that have been implicated in neuronal differentiation. We present a model for sca function based on its phenotypic and molecular features.

The glass gene encodes a zinc-finger protein required by Drosophila photoreceptor cells.

Null mutations of glass specifically remove photoreceptor cells, leaving other cell types intact. We have isolated the glass gene and have shown that its transcript encodes a putative protein of 604 amino acids with five zinc-fingers. The glass product may be a transcription factor required for the development of a single neuronal cell type.

Expression of Drosophila glass protein and evidence for negative regulation of its activity in non-neuronal cells by another DNA-binding protein.

The glass gene encodes a DNA-binding zinc-finger protein required for the development of Drosophila photoreceptor cells and which appears to regulate a number of genes specifically expressed in photoreceptors. We have generated monoclonal antibodies to Glass and used them to examine Glass distribution during development. Glass is expressed in all cell types of the developing eye and in all other organs that contain photoreceptor cells in Drosophila, including a small number of cells in the brain. We altered the normal pattern of glass expression by placing the gene under the control of the hsp70 promoter. Our results suggest that nonphotoreceptor cells are restricted in their response to Glass expression. In an effort to discover the mechanism of this restriction, we examined the expression of a number of reporter gene constructs. Our results suggest that nonsensory cells are unable to express certain reporter constructs in response to Glass expression because another DNA-binding factor represses Glass activity in nonsensory cells.

Drosophila Jun mediates Ras-dependent photoreceptor determination.

The expression of the D. melanogaster transcription factor Jun in the eye imaginal disc correlates temporally and spatially with the determination of neuronal photoreceptor fate. Expression of dominant negative forms of Jun in photoreceptor precursor cells results in dose-dependent loss of photoreceptors in the adult fly. Conversely, localized overexpression of Jun in the eye imaginal disc can induce the differentiation of additional photoreceptor cells. Furthermore, the transformation of nonneuronal cone cells into R7 neurons elicited by constitutively active forms of sevenless, Ras1, Raf, and MAP kinase is relieved in the presence of Jun mutants. These results demonstrate a requirement of Jun downstream of the sevenless/ras signaling pathway for neuronal development in the Drosophila eye.

Functional domain analysis of glass, a zinc-finger-containing transcription factor in Drosophila.

The glass gene is required for proper photo-receptor differentiation during development of the Drosophila eye glass codes for a DNA-binding protein containing five zinc fingers that we show is a transcriptional activator. A comparison of the sequences of the glass genes from two species of Drosophila and a detailed functional domain analysis of the Drosophila melanogaster glass gene reveal that both the DNA-binding domain and the transcriptional-activation domain are highly conserved between the two species. Analysis of the DNA-binding domain of glass indicates that the three carboxyl-terminal zinc fingers alone are necessary and sufficient for DNA binding. We also show that a deletion mutant of glass containing only the DNA-binding domain can behave in a dominant-negative manner both in vivo and in a cell culture assay that measures transcriptional activation.

Mutations on the second chromosome affecting the Drosophila eye.

In the developing eye of Drosophila, cell interactions appear to be responsible for organising undifferentiated cells into unit eyes, or ommatidia. Extensive mutagenesis has been used to search for mutations affecting the development and differentiation of ommatidia. These mutations have been characterized using sections of adults and immunocytochemistry of imaginal discs. Fourteen loci on the second chromosome are described that affect the spacing of the preclusters, the differentiation of ommatidial cells, orientation of the ommatidia, or architecture of the adult retina, that cause retinal degeneration in larval or pupal eye discs, or that cause homeotic transformation of part of the head.

Expression of engrailed proteins in arthropods, annelids, and chordates.

engrailed is a homeobox gene that has an important role in Drosophila segmentation. Genes homologous to engrailed have been identified in several other organisms. Here we describe a monoclonal antibody that recognizes a conserved epitope in the homeodomain of engrailed proteins of a number of different arthropods, annelids, and chordates; we use this antibody to isolate the grasshopper engrailed gene. In Drosophila embryos, the antibody reveals engrailed protein in the posterior portion of each segment during segmentation, and in a segmentally reiterated subset of neuronal cells during neurogenesis. Other arthropods, including grasshopper and two crustaceans, have similar patterns of engrailed expression. However, these patterns of expression are not shared by the annelids or chordates we examined. Our results provide the most comprehensive view that has been obtained of how expression patterns of a regulatory gene vary during evolution. On the basis of these patterns, we suggest that engrailed is a gene whose ancestral function was in neurogenesis and whose function was co-opted during the evolution of segmentation in the arthropods, but not in the annelids and chordates.

Single nucleotide polymorphism markers for genetic mapping in Drosophila melanogaster.

For nearly a century, genetic analysis in Drosophila melanogaster has been a powerful tool for analyzing gene function, yet Drosophila lacks the molecular genetic mapping tools that recently have revolutionized human, mouse, and plant genetics. Here, we describe the systematic characterization of a dense set of molecular markers in Drosophila by using a sequence tagged site-based physical map of the genome. We identify 474 biallelic markers in standard laboratory strains of Drosophila that span the genome. Most of these markers are single nucleotide polymorphisms and sequences for these variants are provided in an accessible format. The average density of the new markers is one per 225 kb on the autosomes and one per megabase on the X chromosome. We include in this survey a set of P-element strains that provide additional use for high-resolution mapping. We show one application of the new markers in a simple set of crosses to map a mutation in the hedgehog gene to an interval of <1 Mb. This new map resource significantly increases the efficiency and resolution of recombination mapping and will be of immediate value to the Drosophila research community.

HLA class II haplotype and sequence analysis support a role for DQ in narcolepsy.

A systematic haplotype and sequencing analysis of the HLA-DR and -DQ region in patients with narcolepsy was performed. Five new (CA)n microsatellite markers were generated and positioned on the physical map across the HLA-DQB1-DQA1-DRB1 interval. Haplotypes for these new markers and the three HLA loci were established using somatic cell hybrids generated from patients. A four-marker haplotype surrounding the DQB1(*)0602 gene was found in all narcolepsy patients, and was identical to haplotypes observed on random chromosomes harboring the DQB1(*)0602 allele. Eighty-six kilobases of contiguous genomic sequence across the region did not reveal new genes, and analysis of this sequence for single nucleotide polymorphisms did not reveal sequence variation among DQB1(*)0602 chromosomes. These results are consistent with other studies, suggesting that the HLA-DQ genes themselves are among the predisposing factors in narcolepsy.