Mapping the effects of ozone pollution and mixing on floral odour plumes and their impact on plant-pollinator interactions

The critical ecological process of animal-mediated pollination is commonly facilitated by odour cues. These odours consist of volatile organic compounds (VOCs), often with short chemical lifetimes, which form the strong concentration gradients necessary for pollinating insects to locate a flower. Atmospheric oxidants, including ozone pollution, may react with and chemically alter these VOCs, impairing the ability of pollinators to locate a flower, and therefore the pollen and nectar on which they feed. However, there is limited mechanistic empirical evidence to explain these processes within an odour plume at temporal and spatial scales relevant to insect navigation and olfaction. We investigated the impact of ozone pollution and turbulent mixing on the fate of four model floral VOCs within odour plumes using a series of controlled experiments in a large wind tunnel. Average rates of chemical degradation of α-terpinene, β-caryophyllene and 6-methyl-5-hepten-2-one were slightly faster than predicted by literature rate constants, but mostly within uncertainty bounds. Mixing reduced reaction rates by 8-10% in the first 2 m following release. Reaction rates also varied across the plumes, being fastest at plume edges where VOCs and ozone mixed most efficiently and slowest at plume centres. Honeybees were trained to learn a four VOC blend equivalent to the plume released at the wind tunnel source. When subsequently presented with an odour blend representative of that observed 6 m from the source at the centre of the plume, 52% of honeybees recognised the odour, decreasing to 38% at 12 m. When presented with the more degraded blend from the plume edge, recognition decreased to 32% and 10% at 6 and 12 m respectively. Our findings highlight a mechanism by which anthropogenic pollutants can disrupt the VOC cues used in plant-pollinator interactions, which likely impacts on other critical odour-mediated behaviours such as mate attraction.

Do we need high temporal resolution modelling of exposure in urban areas? A test case

Roadside concentrations of harmful pollutants such as NO_x are highly variable in both space and time. This is rarely considered when assessing pedestrian and cyclist exposures. We aim to fully describe the spatio-temporal variability of exposures of pedestrians and cyclists travelling along a road at high resolution. We evaluate the value added of high spatio-temporal resolution compared to high spatial resolution only. We also compare high resolution vehicle emissions modelling to using a constant volume source. We highlight conditions of peak exposures, and discuss implications for health impact assessments. Using the large eddy simulation code Fluidity we simulate NO_x concentrations at a resolution of 2 m and 1 s along a 350 m road segment in a complex real-world street geometry including an intersection and bus stops. We then simulate pedestrian and cyclist journeys for different routes and departure times. For the high spatio-temporal method, the standard deviation in 1 s concentration experienced by pedestrians (50.9 μg.m^-3) is nearly three times greater than that predicted by the high-spatial only (17.5 μg.m^-3) or constant volume source (17.6 μg.m^-3) methods. This exposure is characterised by low concentrations punctuated by short duration, peak exposures which elevate the mean exposure and are not captured by the other two methods. We also find that the mean exposure of cyclists on the road (31.8 μg.m^-3) is significantly greater than that of cyclists on a roadside path (25.6 μg.m^-3) and that of pedestrians on a sidewalk (17.6 μg.m^-3). We conclude that ignoring high resolution temporal air pollution variability experienced at the breathing time scale can lead to a mischaracterization of pedestrian and cyclist exposures, and therefore also potentially the harm caused. High resolution methods reveal that peaks, and hence mean exposures, can be meaningfully reduced by avoiding hyper-local hotspots such as bus stops and junctions.

The perceptions of construction workers on designing a workplace nutrition intervention in the UK

 

According to the European Commission, construction is an important industry providing the EU with 18 million jobs and contributing to 9% of the EU's GDP in 2020. Construction workers struggle with healthy food choices due to lack of knowledge, long working hours, remote site locations, poor food facilities on site, and temporary accommodation. Yet, nutrition interventions in construction are rare, with no UK studies. This is an exploratory study designed to investigate workers' perceptions of a workplace intervention to facilitate healthy nutrition choices. Engaging participants in the intervention design showed positive results on behaviour change. Five internally homogenous focus groups were conducted on three different construction sites (in three companies); two with managers (n = 11) and three with workers (including subcontractors) (n = 27). Sites differed in size (14; 50-100; and 300 workers); two were temporary. Framework Analysis was used to analyse data. The main themes uncovered in the focus groups were; 1) the need for workers to learn about food to sustain good energy levels, as deemed crucial for their job 2) the desire to get an understanding about portion sizes, food labels, impacts of food on mood and practical ideas of healthy snacks and meal planning and 3) the importance of intervention accessibility for everybody on site (including subcontractors), convenient scheduling and location, and managers support to encourage participation. A participatory approach was used to explore workers' suggestions on the content and delivery of the nutrition intervention. Education and practicality of recommendations were of the essence to workers, who suggested that individual characteristics, the nature of construction jobs (e.g. busy schedules, transient jobs), and resources available (e.g. storage) need to be considered when designing the intervention. Inclusivity, accessibility and managerial support were regarded as valuable in the intervention delivery.

Key messages

This research produced recommendations to encourage the development and implementation of inclusive nutrition interventions in construction, to improve the health and wellbeing of workers. This research invites public health consultants and senior leaders in construction to invest in supporting healthy behaviours of workers, with a consideration of job and workplace characteristics.

Variability of physical meteorology in urban areas at different scales: implications for air quality

Air quality in cities is influenced not only by emissions and chemical transformations but also by the physical state of the atmosphere which varies both temporally and spatially. Increasingly, tall buildings (TB) are common features of the urban landscape, yet their impact on urban air flow and dispersion is not well understood, and their effects are not appropriately captured in parameterisation schemes. Here, hardware models of areas within two global mega-cities (London and Beijing) are used to analyse the impact of TB on flow and transport in isolated and cluster settings. Results show that TB generate strong updrafts and downdrafts that affect street-level flow fields. Velocity differences do not decay monotonically with distance from the TB, especially in the near-wake region where the flow is characterised by recirculating winds and jets. Lateral distance from an isolated TB centreline is crucial, and flow is still strongly impacted at longitudinal distances of several TB heights. Evaluation of a wake-flow scheme (ADMS-Build) in the isolated TB case indicates important characteristics are not captured. There is better agreement for a slender, shorter TB than a taller non-cuboidal TB. Better prediction of flow occurs horizontally further away and vertically further from the surface. TB clusters modify the shape of pollutant plumes. Strong updrafts generated by the overlapping wakes of TB clusters lift pollutants out of the canopy, causing a much deeper tracer plume in the lee of the cluster, and an elevated plume centreline with maximum concentrations around the TB mean height. Enhanced vertical spread of the pollutants in the near-wake of the cluster results in overall lower maximum concentrations, but higher concentrations above the mean TB height. These results have important implications for interpreting observations in areas with TB. Using real world ceilometer observations in two mega-cities (Beijing and Paris), we assess the diurnal seasonal variability of the urban boundary layer and evaluate a mixed layer height (MLH) empirical model with parameters derived from a third mega-city (London). The MLH model works well in central Beijing but less well in suburban Paris. The variability of the physical meteorology across different vertical scales discussed in this paper provides additional context for interpreting air quality observations.

A Comparison of a Direct Electron Detector and a High-Speed Video Camera for a Scanning Precession Electron Diffraction Phase and Orientation Mapping

A scanning precession electron diffraction system has been integrated with a direct electron detector to allow the collection of improved quality diffraction patterns. This has been used on a two-phase α–β titanium alloy (Timetal® 575) for phase and orientation mapping using an existing pattern-matching algorithm and has been compared to the commonly used detector system, which consisted of a high-speed video-camera imaging the small phosphor focusing screen. Noise is appreciably lower with the direct electron detector, and this is especially noticeable further from the diffraction pattern center where the real electron scattering is reduced and both diffraction spots and inelastic scattering between spots are weaker. The results for orientation mapping are a significant improvement in phase and orientation indexing reliability, especially of fine nanoscale laths of α-Ti, where the weak diffracted signal is rather lost in the noise for the optically coupled camera. This was done at a dose of ~19 e−/Å2, and there is clearly a prospect for reducing the current further while still producing indexable patterns. This opens the way for precession diffraction phase and orientation mapping of radiation-sensitive crystalline materials.

How tall buildings affect turbulent air flows and dispersion of pollution within a neighbourhood

The city of London, UK, has seen in recent years an increase in the number of high-rise/multi-storey buildings ("skyscrapers") with roof heights reaching 150 m and more, with the Shard being a prime example with a height of ∼310 m. This changing cityscape together with recent plans of local authorities of introducing Combined Heat and Power Plant (CHP) led to a detailed study in which CFD and wind tunnel studies were carried out to assess the effect of such high-rise buildings on the dispersion of air pollution in their vicinity. A new, open-source simulator, FLUIDITY, which incorporates the Large Eddy Simulation (LES) method, was implemented; the simulated results were subsequently validated against experimental measurements from the EnFlo wind tunnel. The novelty of the LES methodology within FLUIDITY is based on the combination of an adaptive, unstructured, mesh with an eddy-viscosity tensor (for the sub-grid scales) that is anisotropic. The simulated normalised mean concentrations results were compared to the corresponding wind tunnel measurements, showing for most detector locations good correlations, with differences ranging from 3% to 37%. The validation procedure was followed by the simulation of two further hypothetical scenarios, in which the heights of buildings surrounding the source building were increased. The results showed clearly how the high-rise buildings affected the surrounding air flows and dispersion patterns, with the generation of "dead-zones" and high-concentration "hotspots" in areas where these did not previously exist. The work clearly showed that complex CFD modelling can provide useful information to urban planners when changes to cityscapes are considered, so that design options can be tested against environmental quality criteria.

Toll-like receptor expression in crypt epithelial cells, putative stem cells and intestinal myofibroblasts isolated from controls and patients with inflammatory bowel disease

The aim of our studies was to investigate the expression of Toll-like receptor (TLR)-2 and TLR-4 (and in some studies TLR-5) in myofibroblasts and small and large intestinal crypt epithelial cells from control patients and those affected by Crohn's disease and ulcerative colitis. Isolated and disaggregated crypt epithelial cells and monolayers of myofibroblasts were used for studies by reverse transcription–polymerase chain reaction (RT–PCR), real-time RT–PCR, flow cytometry, immunocytochemistry and Western blot analysis. Compared to control cells, crypt epithelial cells isolated from active ulcerative colitis and Crohn's disease colonic mucosal samples showed significantly higher expression of TLR-2 and TLR-4 transcripts and protein (on the cell surface). There was also enhanced expression of TLR-4 in crypt cells from ileal Crohn's disease. Expression of TLR-2 and TLR-4 transcripts in crypt epithelial cells isolated from inflamed mucosa of distal ulcerative colitis did not differ significantly from such cells obtained from the normal proximal colon. Crypt epithelial cells with side population characteristics (putative stem cells) also expressed transcripts and protein for TLR-2, TLR-4 and TLR-5. Colonic myofibroblast expression of these TLRs was much weaker than in crypt epithelial cells. In conclusion, enhanced TLR-2 and TLR-4 expression by crypt epithelial cells in active inflammatory bowel disease likely reflects greater ability to respond to microbial products. Results from our studies using mucosal samples from patients with distal ulcerative colitis suggest that the enhanced expression of these TLRs could be constitutive. TLR-2, TLR-4 and TLR-5 expression by stem cells imply ability to respond to distinct bacterial products.

Practical aspects of the use of the X(2) holder for HRTEM-quality TEM sample preparation by FIB

The X(2) holder enables the effective production of thin, electron transparent samples for high-resolution transmission electron microscopy (HRTEM). Improvements to the X(2) holder for high-quality transmission electron microscopy (TEM) sample preparation are presented in this paper. We discuss the influence of backscattered electrons (BSE) from the sample holder in determining the lamella thickness in situ and demonstrate that a significant improvement in thickness determination can be achieved by comparatively simple means using the relative BSE intensity. We show (using Monte Carlo simulations) that by taking into account the finite collection angle of the electron backscatter detector, an approximately 20% underestimation of the lamella thickness in a silicon sample can be avoided. However, a correct thickness determination for light-element lamellas still remains a problem with the backscatter method; we introduce a more accurate method using the energy dispersive X-ray spectroscopy (EDX) signal for in situ thickness determination. Finally, we demonstrate how to produce a thin lamella with a nearly damage-free surface using the X(2) holder in combination with sub-kV polishing in the Fischione Instruments׳ NanoMill(®) TEM specimen preparation system.

Dual diagnosis, as described by those who experience the disorder: using the Internet as a source of data

The complexity of providing treatment for people with dual diagnosis is well recognized. For the purpose of this paper, the World Health Organization definition of dual diagnosis was used; that is, a person diagnosed with an alcohol or drug use problem in addition to mental illness. This research explored the personal narratives of those who experience dual diagnosis using the Internet as a data source. An important consideration in using the Internet as a data source was that Web forums can offer a sense of anonymity, allowing people to share very detailed and personal information, and providing a rich source of qualitative data. The results produced five emergent themes: spiralling out of control - again!, getting help and giving support, treating both the addiction and mental illness, having meaning and being active, and being honest with self and others. The results indicate that individuals who experience dual diagnosis are often left to navigate their personal treatment requirements across two diverse systems, and were generally not satisfied with the conflictual advice received across these two systems (i.e. alcohol and other drug and mental health services). This study has produced valuable insights related to consumer-perceived service barriers and enablers.

Screening ethnically diverse human embryonic stem cells identifies a chromosome 20 minimal amplicon conferring growth advantage

The International Stem Cell Initiative analyzed 125 human embryonic stem (ES) cell lines and 11 induced pluripotent stem (iPS) cell lines, from 38 laboratories worldwide, for genetic changes occurring during culture. Most lines were analyzed at an early and late passage. Single-nucleotide polymorphism (SNP) analysis revealed that they included representatives of most major ethnic groups. Most lines remained karyotypically normal, but there was a progressive tendency to acquire changes on prolonged culture, commonly affecting chromosomes 1, 12, 17 and 20. DNA methylation patterns changed haphazardly with no link to time in culture. Structural variants, determined from the SNP arrays, also appeared sporadically. No common variants related to culture were observed on chromosomes 1, 12 and 17, but a minimal amplicon in chromosome 20q11.21, including three genes expressed in human ES cells, ID1, BCL2L1 and HM13, occurred in >20% of the lines. Of these genes, BCL2L1 is a strong candidate for driving culture adaptation of ES cells.

Differential binding and internalization of Clostridium difficile toxin A by human peripheral blood monocytes, neutrophils and lymphocytes

Colitis due to Clostridium difficile infection is mediated by secreted toxins A and B and is characterized by infiltration by cells from the systemic circulation. The aim of our study was to investigate interactions between fluorescently labelled toxin A and peripheral blood monocytes, neutrophils and lymphocytes. Purified toxin A was labelled with Alexa Fluor® 488 (toxin A(488)) and incubated with isolated human peripheral blood mononuclear cells or washed whole blood cells for varying time intervals at either 37 or 4 °C/ice. The ability of trypan blue to quench cell surface-associated (but not cytoplasmic) fluorescence was also investigated. At 37 °C, toxin A(488) -associated fluorescence in monocytes peaked at 1 h (majority internalized), with subsequent loss associated with cell death. In contrast to monocytes, binding of toxin A(488) in neutrophils was greater on ice than at 37 °C. Studies using trypan blue suggested that over 3 h at 37 °C, most of the toxin A(488)-associated fluorescence in neutrophils remained at the cell surface. Over 48 h (37 °C and ice/4 °C), there was minimal toxin A(488)-associated fluorescence in lymphocytes. These studies suggest major differences in interactions between toxin A and circulating cells that infiltrate the mucosa during colonic inflammation in C. difficile infection.

Air flow and concentration fields at urban road intersections for improved understanding of personal exposure

This paper reviews the state of knowledge on modelling air flow and concentration fields at road intersections. The first part covers the available literature from the past two decades on experimental (both field and wind tunnel) and modelling activities in order to provide insight into the physical basis of flow behaviour at a typical cross-street intersection. This is followed by a review of associated investigations of the impact of traffic-generated localised turbulence on the concentration fields due to emissions from vehicles. There is a discussion on the role of adequate characterisation of vehicle-induced turbulence in making predictions using hybrid models, combining the merits of conventional approaches with information obtained from more detailed modelling. This concludes that, despite advancements in computational techniques, there are crucial knowledge gaps affecting the parameterisations used in current models for individual exposure. This is specifically relevant to the growing impetus on walking and cycling activities on urban roads in the context of current drives for sustainable transport and healthy living. Due to inherently longer travel times involved during such trips, compared to automotive transport, pedestrians and cyclists are subjected to higher levels of exposure to emissions. Current modelling tools seem to under-predict this exposure because of limitations in their design and in the empirical parameters employed.

Mixed methods evaluation research for a mental health screening and referral clinical pathway

RATIONALE

This study is an exemplar of mixed method evaluation research for development of a clinical pathway.

AIM

To develop and evaluate an evidence-based, feasible mental health screening and referral clinical pathway for Department of Veterans' Affairs-funded community nursing care of war veterans and war widows in the Australian context.

METHODS

Mixed methods were applied to formulate and clinically evaluate an appropriate pathway. The pathway was applied at urban and rural sites for the nursing care of 97 war veteran and war widow clients. Evaluative data were collected from clients, their informal carers, community nurses, and general practitioners. Chart auditing and pre-post measures were undertaken. Collaboration occurred with an interdisciplinary design team.

RESULTS

The final modified six-page pathway includes use of validated screening tools (Kessler Psychological Distress Scale [K10]) and Alcohol Use Disorder Identification Test, appropriate referral information, directions for support and health-promoting education, and evidence-based guidelines.

IMPLICATIONS FOR PRACTICE

The clinical pathway is a useful, tested, evidence-based guide for generalist community nurses to identify and suitably respond to common mental healthcare needs of war veterans and war widows. The pathway provides outcomes acceptable to clients and their carers, nurses and doctors.

CONCLUSIONS

This study provides an evaluated clinical pathway for generalist community nurses to screen for mental health difficulties, make appropriate referrals as required and to support war veteran and war widow clients. However, the study also shows how research can be used to develop and evaluate practical, evidence-based clinical pathways.

Evaluation of effectiveness and satisfaction outcomes of a mental health screening and referral clinical pathway for community nursing care

The study aimed to explore the effectiveness of a mental health screening and referral clinical pathway for generalist community nursing care of war veterans and war widow(er)s in Australia on outcomes of client self-reported mental health, quality of life, and client and carer satisfaction. The pathway was developed by literature review and consultation, then trialled and evaluated. Validated screening tools were embedded within the pathway to support generalist nurses' mental health decision making. Pre- and post-measures were applied. Clients on whom the pathway was trialled were invited to complete an evaluation survey questionnaire, as were their informal carers. Most clients and carers who responded to these questionnaires were highly satisfied or satisfied with care provided through application of the pathway. This study adds understanding about one way that community nurses might identify people with mental health difficulties. The trialled pathway, which was modified and refined following the study, is now available on the Internet as an evidence-based resource for community nurses in Australia to guide practice and maximize holistic care for war veterans and war widow(er)s where that care is funded by Department of Veterans' Affairs.

An overview of experimental results and dispersion modelling of nanoparticles in the wake of moving vehicles

Understanding the transformation of nanoparticles emitted from vehicles is essential for developing appropriate methods for treating fine scale particle dynamics in dispersion models. This article provides an overview of significant research work relevant to modelling the dispersion of pollutants, especially nanoparticles, in the wake of vehicles. Literature on vehicle wakes and nanoparticle dispersion is reviewed, taking into account field measurements, wind tunnel experiments and mathematical approaches. Field measurements and modelling studies highlighted the very short time scales associated with nanoparticle transformations in the first stages after the emission. These transformations strongly interact with the flow and turbulence fields immediately behind the vehicle, hence the need of characterising in detail the mixing processes in the vehicle wake. Very few studies have analysed this interaction and more research is needed to build a basis for model development. A possible approach is proposed and areas of further investigation identified.

An evaluation of a mental health screening and referral pathway for community nursing care: nurses' and general practitioners' perspectives

AIMS AND OBJECTIVES

To evaluate a feasible, best practice mental health screening and referral clinical pathway for generalist community nursing care of war veterans and war widow(er)s in Australia.

BACKGROUND

War veterans commonly experience mental health difficulties and do not always receive required treatment, as can also occur for war widow(er)s. Whenever opportunity arises, such as during community nursing care, it is vital to identify mental health problems in a health promotion framework.

DESIGN

A clinical pathway was developed by literature review and consultation and then trialled and evaluated using mixed methods--quantitative and qualitative.

METHODS

Community nurses who trialled the pathway completed an evaluation survey and attended focus groups. General practitioners responded to an evaluation survey.

RESULTS

Most nurses found the pathway clear and easy to understand but not always easy to use. They emphasised the need to establish trust and rapport with clients prior to implementing the pathway. It was sometimes difficult to ensure effective referral to general practitioners for clients who screened positive for a mental health problem. When referral was accomplished, general practitioners reported adequate and useful information was provided. Some general practitioners also commented on the difficulty of achieving effective communication between general practitioners and nurses.

CONCLUSIONS

Nurses and some general practitioners found the pathway useful for their practice. They offered several suggestions for improvement by simplifying the trialled pathway and accompanying guidelines and strategies to improve communication between nurses and general practitioners. This study adds understanding of how community nurses might productively screen for mental health difficulties.

RELEVANCE TO CLINICAL PRACTICE

The trialled pathway, which was modified and refined following the study, is an evidence-based resource for community nurses in Australia and similar contexts to guide practise and maximise holistic care for war veterans and war widow(er)s and possibly other client groups.

Comparison of the behaviour of manufactured and other airborne nanoparticles and the consequences for prioritising research and regulation activities

Currently, there are no air quality regulations in force in any part of the world to control number concentrations of airborne atmospheric nanoparticles (ANPs). This is partly due to a lack of reliable information on measurement methods, dispersion characteristics, modelling, health and other environmental impacts. Because of the special characteristics of manufactured (also termed engineered or synthesised) nanomaterials or nanoparticles (MNPs), a substantial increase is forecast for their manufacture and use, despite understanding of safe design and use, and health and environmental implications being in its early stage. This article discusses a number of underlining technical issues by comparing the properties and behaviour of MNPs with anthropogenically produced ANPs. Such a comparison is essential for the judicious treatment of the MNPs in any potential air quality regulatory framework for ANPs.

The origin and foot condition of horses slaughtered in Australia for the human consumption market

REASONS FOR PERFORMING STUDY

There are ethical concerns regarding the loss of horses from various equine industries and their corresponding slaughter. However, to date, no empirical evidence regarding the extent of this loss, nor of the condition of horses involved, exists within Australia.

OBJECTIVES

To determine the approximate ages, brand type and condition of feet of horses relinquished to an export abattoir in Australia.

METHOD

Data were collected from 340 horses processed at an Australian abattoir from November 2007-January 2008. Foot abnormalities, injuries and hoof indicators of overgrown and untrimmed hooves were assessed together with a dental inspection. Observations of brand were used to determine horse origin.

RESULTS

The dental age of 60% of horses was 57 years, and 53% originated from the racing industry (40% Thoroughbred and 13% Standardbred). A total of 81% of the horses had overgrown or untrimmed hooves. Standardbred horses had fewer grass cracks and more injuries to the coronary band than Thoroughbreds, probably due to pacing and trotting activities.

CONCLUSIONS

Just over half of the horses slaughtered at an Australian abattoir on 3 working days were aged (7 years and emanated from the racing industry. Foot problems were common.

POTENTIAL RELEVANCE

Future research should identify means of reducing the number of horses slaughtered and preventative measures for foot disorders.

Evaluation of methodologies for exposure assessment to atmospheric pollutants from a landfill site

Epidemiological studies around landfill sites are limited by several factors, particularly a lack of accurate exposure assessment. Traditionally, exposure estimates are based on distance between place of residence and the landfill site. However, this measure of exposure ignores the effects that environmental factors may have upon exposure. A previous epidemiological study at a landfill site in the United Kingdom provided the basis for a case study to investigate exposure assessment methodologies that could support ongoing and future epidemiological work. Estimation of relative exposure to atmospheric pollutants near the site was refined using the Atmospheric Dispersion Modeling System (ADMS) 3.1. Annual average concentrations were calculated around the landfill site, which was modeled as an area source with a steady release rate over its entire active surface. Local meteorological and terrain data were used in the assessment. A geographical information system (GIS) was then used to link the results of the modeling to population and other data. Sensitivity studies were included to examine the variation of predicted exposure with several modeling assumptions and hence set other uncertainties in context. No simple relationship existed between the relative individual exposure measured by distance from the site and by dispersion modeling. A reassessment of exposure assessment in epidemiological studies around landfill sites was then undertaken with the refined estimates of exposure. This concluded that use of distance from the site as a proxy for exposure could lead to significant exposure misclassification in comparison with exposure assessment using atmospheric dispersion modeling and GIS. The study also indicated that assessment of peak exposure rates (i.e., extreme concentration levels) might be necessary in some epidemiological work. Optimum strategies for increasing the probability of observing effects in the more highly exposed population can be derived by combining the results of dispersion modeling with population data and, where feasible, knowledge of the toxicology of the substances of interest.

Long-term homelessness in men with a psychosis: Limitation of services

A proportion of persistently homeless men with psychosis are unable to function in the community, despite intensive outreach. The present study aimed to (i) develop a method to measure the number of homeless clients with a psychosis who are unable to maintain basic levels of function, despite the application of intensive community treatment; and (ii) determine if the proportion of these men had increased in an Australian inner urban setting over a 5-year period. Criteria were developed and validated to define this group. A review of records of clients engaged in homeless settings was conducted in order to compare the proportion of men with these features in 2000 and 2005. In 2005, 23% met the criterion of long-term homelessness with poor function, despite intensive outreach, as compared with 17% in 2000 (P = 0.62). The 2005 cohort was more likely to have attempted intensive community psychiatric treatment (P = 0.04). We conclude that a proportion of homeless men with a psychosis in Australia do not achieve basic function, despite access to intensive outreach. The proportion of these men did not change between 2000 and 2005. These men require additional specialized services, including access to long-term supported housing.

Characterization of putative stem cells in isolated human colonic crypt epithelial cells and their interactions with myofibroblasts

Colonic epithelial stem cells are believed to be located at the crypt base where they have previously been shown to express musashi-1. The colonic stem cell niche, which includes extracellular matrix and myofibroblasts (together with other cell types), is likely to be important in maintaining the function of the progenitor cells. The aims of our studies were to characterize stem cells in isolated and disaggregated human colonic crypt epithelial cells and investigate their interactions with monolayers of primary human colonic myofibroblasts. In unfractionated preparations of disaggregated colonic crypts, musashi-1 positive cells preferentially adhered to colonic myofibroblasts, despite the presence of excess blocking anti-beta(1)-integrin antibody. These adherent epithelial cells remained viable for a number of days and developed slender processes. Cells with side population characteristics (as demonstrated by ability to expel the dye Hoechst 33342) were consistently seen in the isolated colonic crypt epithelial cells. These side population cells expressed musashi-1, beta(1)-integrin, BerEP4, and CD133. Sorted side population crypt epithelial cells also rapidly adhered to primary colonic myofibroblasts. In conclusion, in preparation of isolated and disaggregated human colonic crypts, cells with stem cell characteristics preferentially adhere to primary human colonic myofibroblasts in a beta(1)-integrin-independent fashion.

Developing more positive attitudes towards mental health nursing in undergraduate students: part 2--The impact of theory and clinical experience

Previous research examining the impact of education on nursing students' attitudes towards mental health nursing as a career has highlighted clinical experience as the primary influencing factor and generally has not considered the impact of theory. The current study compared a cohort of second-year and a cohort of third-year nursing students from the same university. Second-year students had received more theory and clinical experience than their counterparts. Questionnaires were distributed to the total population of students before commencement of, and after completion of clinical placement. This paper examines students' perceived preparedness for and satisfaction with clinical experience, attitudes towards people with mental illness, and attitudes towards mental health nursing as a career option following the completion of differing amounts of theory and clinical experience. The results demonstrate some statistically significant differences with increased amounts of theory and clinical experience in the second-year cohort being positively influential. The findings suggest that an increased component of theoretical and clinical experience in psychiatric/mental health nursing is likely to produce more positive attitudes towards people with mental illness and psychiatric/mental health nursing. However, little difference in perceived preparedness for and satisfaction with clinical experience was noted between the two cohorts.

Developing more positive attitudes towards mental health nursing in undergraduate students: part 1--does more theory help?

Negative attitudes towards mental illness and the mental health nursing profession have deterred many undergraduate nursing students from considering this area as an attractive career option. Positive clinical experience has been identified as the most important factor in producing more favourable attitudes. While the quantity of theory is identified as important, its impact on attitudes has not been examined through research. This study compared two groups of students undertaking different numbers of theoretical and clinical hours in mental health nursing to determine if this increase has an impact on nursing students' attitudes. Anonymous questionnaires were distributed to the total population of students following completion of the theoretical component of the programme but prior to clinical experience. The questionnaire was designed to assess: (1) nursing student's preparedness for and attitudes towards the mental health field; (2) consumers of mental health services; and (3) the students' career preferences. This first paper in a two-part series examines the impact of theoretical hours and suggests that while other attitudes are fairly similar between the two groups, the group exposed to more theory exhibited significantly more positive attitudes towards psychiatric nursing as a career.

An immunoglobulin E-reactive chimeric human immunoglobulin G1 anti-idiotype inhibits basophil degranulation through cross-linking of FcepsilonRI with FcgammaRIIb

BACKGROUND

IgE binds to mast cells and basophils via its high-affinity receptor, FcepsilonRI, and cross-linking of FcepsilonRI-bound IgE molecules by allergen leads to the release of allergic mediators characteristic of type I hypersensitivity reactions. Previous work has shown that cross-linking of FcepsilonRI with FcgammaRIIb, an ITIM-containing IgG receptor, leads to inhibition of basophil triggering. 2G10, a chimeric human IgG1 anti-idiotype, has broad reactivity with human IgE and as such has the potential to bind simultaneously to FcepsilonRI-bound IgE, via its Fab regions, and the negative regulatory receptor, FcgammaRIIb, via its Fc region.

OBJECTIVE

To assess the ability of human 2G10 to inhibit anti-IgE and allergen-driven basophil degranulation through cross-linking of FcepsilonRI-bound IgE with FcgammaRIIb.

METHODS

2G10 was assessed for its ability to bind to FcgammaRIIb on transfected cells and on purified basophils. In the basophil degranulation assay, basophils were purified from peripheral blood of atopic individuals and activated with either anti-IgE or the house dust mite allergen Der p 1, in the presence or absence of human 2G10. Basophil activation was quantified by analysis of CD63 and CD203c expression on the cell surface, and IL-4 expression intracellularly, using flow cytometery.

RESULTS

Human 2G10 was able to bind to FcgammaRIIb on transfected cells and on purified basophils, and induce a dose-dependent inhibition of both anti-IgE and Der p 1-driven degranulation of basophils.

CONCLUSION

The inhibition of basophil degranulation by the human IgG1 anti-idiotype 2G10 highlights the therapeutic potential of IgE-reactive IgG antibodies in restoring basophil integrity through recruitment of the inhibitory receptor FcgammaRIIb.

The radiological manifestations of sickle cell disease

Sickle cell disease (SCD) is an inherited abnormality of the beta-globin chain, which causes a spectrum of haemolytic anaemias. Clinical manifestations in SCD include anaemia, jaundice, recurrent vaso-occlusive crises, and infections (particularly by encapsulated bacteria) due to functional asplenia and cerebrovascular accidents. Radiological investigations play a critical role both in the diagnosis and in the primary prevention of the complications of SCD.

Sustainable waste management in the UK: the public health role

This paper discusses waste management in the UK and its relationship with health. It aims to outline the role of health professionals in the promotion of waste management, and argues for a change in their role in waste management regulation to help make the process more sustainable. The most common definition of sustainable development is that by the Brundtland commission, i.e. "development that meets the needs of the present without compromising the ability of future generations to meet their own needs". Managing waste sites in a manner that minimises toxic impacts on the current and future generations is obviously a crucial part of this. Although the management of waste facilities is extremely complex, the Integrated Pollution Prevention and Control regime, which requires the input of public health professionals on the regulation of such sites, means that all waste management installations should now be operating in a fashion that minimises any toxicological risks to human health. However, the impacts upon climate change, resource use and health inequalities, as well as the effects of waste transportation, are currently not considered to be part of public health professionals' responsibilities when dealing with these sites. There is also no requirement for public health professionals to become involved in waste management planning issues. The fact that public health professionals are not involved in any of these issues makes it unlikely that the potential impacts upon health are being considered fully, and even more unlikely that waste management will become more sustainable. This paper aims to show that by only considering direct toxicological impacts, public health professionals are not fully addressing all the health issues and are not contributing towards sustainability. There is a need for a change in the way that health professionals deal with waste management issues.

Dendritic cell biology, dysfunction and immunotherapy in gastrointestinal cancers

Gastrointestinal (GI) cancers make up a significant proportion of newly diagnosed malignant disease. The five-year survival for these GI cancers is poor. Anti-cancer host defences are thought to play a role in these cancers, albeit they are suboptimal. Novel immunotherapies are being introduced to treat such patients. This review describes basic cell biology of dendritic cells, as they are thoughtto play a key role in generating effective anti-tumour responses. Dendritic cell dysfunction in patients with various cancers is documented and immunotherapy using dendritic cells in a range of GI cancers is described and discussed

Inflammatory bowel disease: dysfunction of GALT and gut bacterial flora (I)

Gut-associated lymphoid tissue (GALT) is the largest lymphoid organ in the body. This is not surprising considering the huge load of antigens (Ags) from food and commensal bacteria with which it interacts on a daily basis. Gut-associated lymphoid tissue has to recognise and allow the transfer of beneficial Ags whilst concurrently dealing with and successfully removing putative and overtly harmful Ags. This distinctive biological feature of GALT is believed to be crucial to good health. Deregulation or dysfunction of GALT is thought to predispose to inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn's disease. The exact mechanism(s) underlying the pathogenesis of IBD is (are) poorly understood and the immunological defects in GALT are poorly documented. Advances in immunology have highlighted the importance of dendritic cells (DCs), which are the key Ag presenting cells in tissues and lymphoid compartments. Their crucial role in GALT, in health and disease is discussed in this review. Interaction of DCs with T cells in the gut produces a subset of T lymphocytes, which have immunosuppressive function. Inappropriate Ag uptake and presentation to naïve T cells in mesenteric lymph nodes may lead to T cell tolerance in GALT. These various complex factors in the gut are discussed and their possible relevance to IBD evaluated.

Sustainable development of urban transport systems and human exposure to air pollution

DAPPLE (Dispersion of Air Pollution and Penetration into the Local Environment, http://www.dapple.org.uk) is a major research project that will provide the understanding necessary to assess the sustainability of urban road transport in terms of exposure to traffic-related air pollution as an alternative to current indicators based on emissions, roadside, or far-from-road air pollution levels. The methodology is described, which combines on-street and laboratory measurement with modelling of the movement of air, vehicles, and vehicle exhaust emissions. The relationship between this kind of assessment and more realistic indicators of sustainability is discussed. The value of large-scale interdisciplinary research in this area is thus demonstrated.

Introduction to the DAPPLE Air Pollution Project

The Dispersion of Air Pollution and its Penetration into the Local Environment (DAPPLE) project brings together a multidisciplinary research group that is undertaking field measurements, wind tunnel modelling and computer simulations in order to provide better understanding of the physical processes affecting street and neighbourhood-scale flow of air, traffic and people, and their corresponding interactions with the dispersion of pollutants at street canyon intersections. The street canyon intersection is of interest as it provides the basic case study to demonstrate most of the factors that will apply in a wide range of urban situations. The aims of this paper are to introduce the background of the DAPPLE project, the study design and methodology for data collection, some preliminary results from the first field campaign in central London (28 April-24 May 2003) and the future for this work. Updated information and contact details are available on the web site at http://www.dapple.org.uk.

Assessment of Be1 and Be2 cells in systemic lupus erythematosus indicates elevated interleukin-10 producing CD5+ B cells

Recent studies indicate that normal B cells can be primed to differentiate into two distinct cytokine-secreting effector subsets, Be1 and Be2. The aim of this study was to analyse, for the first time, Be1 and Be2 cells at the single cell level in SLE patients using the recently developed technique of flow cytometry for intracellular cytokines. Peripheral blood mononuclear cells (PBMC) from SLE patients and age- and sex-matched normal controls were cultured for 24 h in the presence or absence of phorbal myristate acetate and ionomycin (PMA/I) or lipopolysaccharide (LPS). The production of type I (IFN-gamma, IL-2) and type 2 (IL-4, IL-5, IL-6, IL-10, IL-13) cytokines by B cells (and IL-10 production by fractionated CD5+ and CD5- B cells) was investigated using an intracellular cytokine staining technique and flow cytometry. In the absence of PMA/I stimulation, the percentage of B cells from SLE patients was significantly lower than those of normal subjects and significantly more SLE B cells spontaneously produced IL-10 than controls. Moreover, CD5+ B cells from SLE patients were enriched for cells with signs of previous in vivo activation and for high levels of IL-10 production. A significant positive correlation was observed between the percentage of IL-10- and IL-6-producing PMA/I-stimulated B cells in SLE patients, but not in controls. There were no significant differences in the production of other cytokines by B cells of SLE patients and normal subjects. In conclusion, a general alteration of type 1 and type 2 cytokine production by B cells is not observed in SLE patients. The role of B cell cytokines in the pathogenesis of SLE appears to be exerted by elevated secretion of in vivo IL-10, which may play an important role in the immune dysregulation observed in SLE patients. Moreover, the cross regulation of IL-10 and IL-6 is disrupted in SLE patients.

Inflammatory bowel disease: dysfunction of GALT and gut bacterial flora (II)

The precise cause(s) of Crohn's disease and ulcerative colitis are unknown. From animal models and human studies it is well established that gut bacterial flora are essential for inducing the bowel inflammation. Animal models, when kept in a germ-free environment, do not develop colitis until the gut flora is reconstituted. It is not clear whether the bacterial antigens (Ags) from the normal flora or some other pathogenic bacterial Ags induce/propagate the inflammatory process in inflammatory bowel disease (IBD). Despite extensive research it has not been possible to identify any specific bacteria or virus as a credible cause of IBD. Recent understanding of quorum sensing molecules (QSMs) secreted by bacteria helps to explain the community behaviour in bacterial species. When QSMs reach a defined concentration, they activate bacterial proliferation and a number of virulence genes. Also, these molecules have been found to modulate the immune system to the advantage of the gut bacteria. They have not been well studied, however, in the gut. Inappropriate secretion of QSMs may alter the gut-associated lymphoid tissue (GALT) and, thereby, deregulate the immune tolerance normally present. Usefulness of probiotics and their immune modulating effects are being increasingly reported. Probiotics are also being used in the treatment of IBD. The interaction between the epithelial cells and the gut flora is very important as this is the first line of contact; this interaction may determine the induction of tolerance and mucosal integrity or immune activity, tissue inflammation and abnormal permeability. The latter is documented in patients with IBD and their healthy relatives. This may be an important factor in disruption of mucosal integrity and GALT dysfunction.

Characterization of humoral and cellular immune responses elicited by meningococcal carriage

In order to study the immune response elicited by asymptomatic carriage of Neisseria meningitidis, samples of serum, peripheral blood mononuclear cells (PBMCs), and saliva were collected from a cohort of more than 200 undergraduate students in Nottingham, United Kingdom, who were subject to high rates of acquisition and carriage of meningococci. Serum immunoglobulin G levels were elevated following increases in the rate of carriage, and these responses were specific for the colonizing strains. In order to investigate T-cell responses, PBMCs from 15 individuals were stimulated with a whole-cell lysate of the H44/76 meningococcal strain (B:15:P1.7,16), stained to detect cell surface markers and intracellular cytokines, and examined by flow cytometry. The cells were analyzed for expression of CD69 (to indicate activation), gamma interferon (IFN-gamma) (a representative T-helper 1 subset [Th1]-associated cytokine), and interleukin-5 (IL-5) (a Th2-associated cytokine). Following a brief meningococcal stimulation, the numbers of CD69(+) IFN-gamma(+) CD56/16(+) NK cells were much higher than cytokine-positive CD4(+) events. Both IFN-gamma(+) and IL-5(+) events were detected among the CD69(+) CD4(+) population, leading to the conclusion that an unbiased T-helper subset response was elicited by meningococcal carriage.

Quantitative and qualitative analysis of the balance between type 1 and type 2 cytokine-producing CD8(-) and CD8(+) T cells in systemic lupus erythematosus

The production of type 1 (IFN-gamma, IL-2) and type 2 (IL-4, IL-5, IL-10, IL-13) cytokines by CD8(-) and CD8(+) T cells from systemic lupus erythematosus (SLE) patients and normal subjects was investigated using an intracellular cytokine-staining technique. This flow cytometric method facilitates analysis of both surface markers and cytoplasmic cytokines, after a short term (6 h) culture with or without phorbol myristate acetate and ionomycin (PMA/I) stimulation. In SLE patients, more unstimulated T cells produced IL-10 in comparison with controls; other cytokines were not detected in unstimulated cells. The percentage of IL-10-secreting T cells did not significantly increase after PMA/I stimulation of cells from SLE patients. The mean intensity of fluorescence (MIF) of intracellular IL-4 staining was significantly higher in CD8(-) T cells of SLE patients than controls. Significantly fewer CD8(-) and CD8(+) T cells from SLE patients secreted IFN-gamma after PMA/I stimulation compared with controls. The MIF and percentage of IL-2, IL-5, and IL-13-secreting cell subsets were not significantly different between SLE patients and controls. These findings indicate that T cells of SLE patients are already stimulated to produce IL-10 in vivo, which may result in downregulation of IFN-gamma secreting CD8(-) and CD8(+) T cells observed following PMA/I stimulation. Thus, the population size of Th1 and Tc1 cells are reduced in SLE patients whereas the effector function of Th2 cells, with respect to IL-4 production, is enhanced in SLE patients. Furthermore, although the balance between Th1/Th2 and between Tc1/Tc2 is disrupted in SLE patients, it is significantly biased in favour of the Th2 subset only.

Human T cell subset commitment determined by the intrinsic property of antigen: the proteolytic activity of the major mite allergen Der p 1 conditions T cells to produce more IL-4 and less IFN-gamma

The house dust mite Dermatophagoides pteronyssinus allergen Der p 1 elicits IgE antibody responses in a significant proportion of patients suffering from dust mite allergy. We have recently shown that Der p 1 proteolytically cleaves a cell surface molecule involved in the homeostatic control of human IgE synthesis, namely the IL-2 receptor (CD25) on T cells. As a result, these T cells show markedly diminished proliferation and IFN-gamma secretion in response to stimulation by anti-CD3 antibody. However, these observations still leave open the important issue of whether CD25 cleavage, and the consequent suppression of IFN-gamma secretion, leads to enhanced IL-4 secretion, and whether such cytokine changes would be exhibited by both CD4 and CD8 T cells. Here we demonstrate for the first time that the proteolytic activity of Der p 1 biases human CD4 and CD8 T cells towards a type 2 cytokine profile. Our data provide compelling evidence for the role of the proteolytic activity of Der p 1 in creating a microenvironment conducive for IgE synthesis.

The consolidation of learning during sleep: comparing the pseudorehearsal and unlearning accounts

We suggest that any brain-like (artificial neural network based) learning system will need a sleep-like mechanism for consolidating newly learned information if it wishes to cope with the sequential/ongoing learning of significantly new information. We summarise and explore two possible candidates for a computational account of this consolidation process in Hopfield type networks. The "pseudorehearsal" method is based on the relearning of randomly selected attractors in the network as the new information is added from some second system. This process is supposed to reinforce old information within the network and protect it from the disruption caused by learning new inputs. The "unlearning" method is based on the unlearning of randomly selected attractors in the network after new information has already been learned. This process is supposed to locate and remove the unwanted associations between information that obscure the learned inputs. We suggest that as a computational model of sleep consolidation, the pseudorehearsal approach is better supported by the psychological, evolutionary, and neurophysiological data (in particular accounting for the role of the hippocampus in consolidation).

Catastrophic forgetting in simple networks: an analysis of the pseudorehearsal solution

Catastrophic forgetting is a major problem for sequential learning in neural networks. One very general solution to this problem, known as 'pseudorehearsal', works well in practice for nonlinear networks but has not been analysed before. This paper formalizes pseudorehearsal in linear networks. We show that the method can fail in low dimensions but is guaranteed to succeed in high dimensions under fairly general conditions. In this case an optimal version of the method is equivalent to a simple modification of the 'delta rule'.

Control of transgenesis in higher cells: the procell transposon Tn10 TetR mRNA has several major hairpins and can be unstable in eucells

The TetR regulatory gene from the transposon Tn10 has some excellent characteristics for transgenic control in higher cells. However, we experienced severe problems with mRNA instability for this gene in eucells (CHO cells). This may be connected with the existence within the Tn10 TetR mRNA of several sizeable hairpins. They resemble canonical RNase E sites for mRNA destabilisation in procells and possibly also in eucells. Two of the hairpins also included sequences resembling eucell hnRNA polyadenylation or processing signals. The TetR counterpart from the plasmid RA1 appears to have less of the hairpin secondary structure; perhaps because of this, it did not present these mRNA instability problems in CHO cells, and it may prove a valuable alternative for transgene control in gene therapy and biotechnology.

Complementary right and left hemifield use for predatory and agonistic behaviour in toads

Cerebral lateralization, the differing specializations of the right and left sides of the brain once thought to be unique of humans, is now well known to occur in both birds and mammals. Here we report that in toads the right hemisfield of vision guides predatory tongue-striking responses towards moving prey and the left hemisfield guides agnostic tongue-striking responses towards conspecifics. This indicates, for the first time, complementary cerebral specializations for visual processing in anurans, and strongly supports the hypothesis that lateralized brain functions in birds and mammals may have arisen from a common lateralized ancestor. Complementary specializations in visual processing may have originally evolved to avoid problem of response competition during control of medial organs such as the tongue in organisms with laterally placed eyes and, in organisms with wider binocular overlap, it appears to be retained for initial detection of stimuli in the extreme lateral fields.

Lateralized agonistic responses and hindlimb use in toads

The recent discovery of forepaw preferences (handedness) in toad species has provided some insight into the evolution of brain lateralization. We tested the prediction that, as in higher vertebrates, visual lateralization and other motor preferences (footedness) also exists in toad species. During feeding periods, South American cane toads, Bufo marinus, showed a population bias to strike with the tongue at other toads occupying their left visual field. This is the first demonstration of lateralized visual behaviour in an amphibian species. Tongue striking at an individual's eyes or head may sometimes delay its approach to prey already seen by the attacker, or may dislodge prey from its mouth. In addition, we report hindlimb preferences (footedness) for contact righting in three species of toad (B. marinus, the European green toad, B. viridis, and the European common toad, B. bufo). After being fully overturned on to their back on a horizontal surface, toads initiated and completed righting using the hindlimbs and with only perfunctory use of the forepaws. Together, the findings of visual lateralization and footedness demonstrate that in toads, as in higher vertebrates, behavioural lateralization is not restricted to handedness. The hypothesis that lateralized brain functions in birds and mammals might have arisen from a common lateralized ancestor is therefore supported. Copyright 1998 The Association for the Study of Animal Behaviour.

A novel flow cytometric assay for quantitating adherence of Helicobacter pylori to gastric epithelial cells

Adherence may be an important virulence factor for Helicobacter pylori. Current methods available for quantitation of adherence are time consuming and liable to observer error. A new direct technique for fluorescent labelling of bacteria has been developed to quantitate adherence of H. pylori to epithelial cells by fluorescence activated cell sorting (FACS). Type strains of H. pylori, H. mustelae, H. cinaedi and H. fennelliae were grown microaerobically in broth culture for 24 h and fluorescently labelled by incubation with carboxyfluorescein diacetate succinimidyl ester (CFDA-SE) at 37 degrees C. After washing to remove excess CFDA-SE, bacteria were co-incubated (ratio 10:1) with gastric epithelial cells at 37 degrees C for up to 24 h. After washing to remove non-adherent bacteria, epithelial cells were detached with EDTA (2 mM) and fixed with formaldehyde for flow cytometry. Adherence was quantitated both in terms of the proportion of cells with adherent H. pylori and as the mean number of adherent bacteria per cell. All H. pylori strains adhered to gastric-type epithelial cells. The proportion of cells with bound bacteria varied from 40-99% and the number of bacteria per cell from 1-50, both of which correlated with microscopy (r = 0.6, and r = 0.8 respectively, n = 35). Time course studies demonstrated saturation of binding by H. pylori within 90 min. For H. mustelae, H. cinaedi and H. fennelliae the proportion of cells with bound bacteria varied from 5-15% and the mean number of bacteria per cell was < 4. Binding of H. pylori to epithelial cells could be partly blocked by pre-incubation with polyclonal anti-sera or using oligosaccharides against potential binding epitopes of gastric mucus. Fluorescent labelling of H. pylori with CFDA-SE in combination with flow cytometry provides a quick, specific, and sensitive method to quantitate in vitro the adherence of H. pylori.

Isolation, purification and assessment of viability of spermatogenic cells from testicular biopsies of azoospermic men

The success of spermatid microinjection has generated many concerns. In particular, there is a lack of appropriate methodology for the isolation of large homogeneous populations of spermatids, with minimum loss of viability, from the testicular tissue of azoospermic men. Here we have compared two different isolation methods -- velocity sedimentation under unit gravity (VSUG) combined with discontinuous Percoll centrifugation (DPC), and separation with fluorescent-activated cell sorter (FACS) using light in the visible range -- to determine the most suitable method for the isolation of spermatids. Total mixed cell count/gram of testicular parenchyma was significantly higher in obstructive azoospermic men compared with non-obstructive azoospermic men (P < 0.001). The results of the comparison showed that in obstructive azoospermic patients the difference in the yields of primary spermatocytes produced by the two techniques was not significant, but for round and elongating spermatids the FACS separation proved to be the better method (P < 0.001). Similarly, in non-obstructive azoospermic patients, FACS separation proved to be superior, giving increased yields of primary spermatocytes and round and elongating spermatids compared with VSUG combined with DPC method (P < 0.001). More than 99 % of the separated cells retained their viability after FACS separation. As large homogeneous populations of viable spermatids can be separated with FACS in a relatively short period of time, FACS separation is the most suitable method for the isolation of spermatids from testicular biopsy tissue.

Quantification of insulin-like growth factor I receptors on granulosa cells with flow cytometry after follicular stimulation

The presence of insulin-like growth factor I (IGF-I) receptors on granulosa cells was investigated by flow cytometric analysis. Granulosa cells were retrieved from follicular fluid after oocyte retrieval during assisted reproduction technology procedures. Whole samples of follicular fluid were pooled and the cellular fraction analysed. In order to analyse granulosa cells only we developed a dual labelling technique whereby granulosa cells were identified as CD45 negative cells, distinguishing them from leukocytes which are CD45 positive. Analysis of the IGF-I receptor was done by staining the sample with a monoclonal anti-IGF-I receptor antibody (alphaIR3 clone) and goat anti-mouse phycoerythrin labelled antibody. After identification of the presence of IGF-I receptors, receptor expression was quantified by calibration of the fluorescence signals. We analysed 10 patients' samples and showed 559-1774 binding sites per granulosa cell with a mean value of 1125 +/- 382 (SD).

Evaluation of joint medical and nursing notes with preprinted prompts

OBJECTIVE

To determine the views of doctors and nurses about two recent innovations in the structure of case notes: the use of preprinted prompts and the use of joint medical and nursing notes.

DESIGN

Questionnaire survey of all doctors and nurses working on the children's wards.

SETTING

Children's wards in a district general hospital.

MAIN OUTCOME MEASURES

Whether or not respondents wanted to return to traditional notes; positive and negative aspects of the two innovations.

RESULTS

There was an 81% response rate. 45 of 48 respondents (94%) did not want to return to traditional notes. Positive features of joint notes that were identified included: promotes team work (21/48 respondents), improves access to information (14/48), and reduces duplication (14/48). Negative features included uncertainty about identity of writer (8/48) and incompletely filled in sheets (7/48). Positive features of preprinted prompts included: less information omitted (29/48), easier to read and find information (28/48), and quicker to write (21/48). Negative features included: not enough space (19/48) and clerking too mechanical (16/48).

CONCLUSION

Advantages of both innovations outweighed their disadvantages to the extent that only three out of 48 respondents wanted to return to writing traditional notes.

Pawedness and Motor Asymmetries in Toads

Pawedness was investigated in three species of toads, Bufo bufo , Bufo viridis , and Bufo marinus. Samples from natural populations were collected in two successive years and tested during attempts to remove a strip of paper stuck onto the snout ( Bufo bufo and Bufo viridis ) or during attempts to remove an elastic balloon wrapped around the head ( Bufo bufo ). A preferential right forelimb use at the population level was observed in Bufo bufo in both tests, whereas no clear pawedness was observed in Bufo viridis. Bufo marinus also showed no laterality in the paper-strip test, but it appeared to be strongly lateralised in another test that investigated which side the toad rotated when turned on its back underwater. Preferentially turning to the toad's left side as part of a righting response, Bufo marinus released the left forelimb first, using the right forelimb to control the roll to the upright position, and push to the surface. These results suggest that preferential limb use has a long evolutionary history, which dates back to early tetrapods.

Flow cytometric analysis of granulosa cells from follicular fluid after follicular stimulation

Granulosa cells are not easily accessible, unless they are examined in follicular fluid after oocyte retrieval. These samples are usually contaminated with blood. We have set up a general technique for analysis of granulosa cells without physically separating them from blood cells. The sample is stained with CD45, which is a pan-leukocyte marker, and granulosa cells are consecutively selected as CD45 negative during flow cytometric analysis. Analysis of forward scatter of the granulosa cells, which is correlated to cell size, shows a wide size range throughout the whole population rather than two distinct populations as previously suggested.