Accuracy of artificial intelligence-assisted growth prediction in skeletal Class I preadolescent patients using serial lateral cephalograms for a 2-year growth interval

OBJECTIVE

To investigate the accuracy of artificial intelligence-assisted growth prediction using a convolutional neural network (CNN) algorithm and longitudinal lateral cephalograms (Lat-cephs).

MATERIALS AND METHODS

A total of 198 Japanese preadolescent children, who had skeletal Class I malocclusion and whose Lat-cephs were available at age 8 years (T0) and 10 years (T1), were allocated into the training, validation, and test phases (n = 161, n = 17, n = 20). Orthodontists and the CNN model identified 28 hard-tissue landmarks (HTL) and 19 soft-tissue landmarks (STL). The mean prediction error values were defined as 'excellent,' 'very good,' 'good,' 'acceptable,' and 'unsatisfactory' (criteria: 0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm, respectively). The degree of accurate prediction percentage (APP) was defined as 'very high,' 'high,' 'medium,' and 'low' (criteria: 90%, 70%, and 50%, respectively) according to the percentage of subjects that showed the error range within 1.5 mm.

RESULTS

All HTLs showed acceptable-to-excellent mean PE values, while the STLs Pog', Gn', and Me' showed unsatisfactory values, and the rest showed good-to-acceptable values. Regarding the degree of APP, HTLs Ba, ramus posterior, Pm, Pog, B-point, Me, and mandibular first molar root apex exhibited low APPs. The STLs labrale superius, lower embrasure, lower lip, point of lower profile, B', Pog,' Gn' and Me' also exhibited low APPs. The remainder of HTLs and STLs showed medium-to-very high APPs.

CONCLUSION

Despite the possibility of using the CNN model to predict growth, further studies are needed to improve the prediction accuracy in HTLs and STLs of the chin area.

How missing evidence-based medicine indicators can inform COVID-19 vaccine distribution policies: a scoping review and calculation of indicators from data in randomised controlled trials

OBJECTIVE

Reports of efficacy, effectiveness and harms of COVID-19 vaccines have not used key indicators from evidence-based medicine (EBM) that can inform policies about vaccine distribution. This study aims to clarify EBM indicators that consider baseline risks when assessing vaccines' benefits versus harms: absolute risk reduction (ARR) and number needed to be vaccinated (NNV), versus absolute risk of the intervention (ARI) and number needed to harm (NNH).

METHODS

We used a multimethod approach, including a scoping review of the literature; calculation of risk reductions and harms from data concerning five major vaccines; analysis of risk reductions in population subgroups with varying baseline risks; and comparisons with prior vaccines.

FINDINGS

The scoping review showed few reports regarding ARR, NNV, ARI and NNH; comparisons of benefits versus harms using these EBM methods; or analyses of varying baseline risks. Calculated ARRs for symptomatic infection and hospitalisation were approximately 1% and 0.1%, respectively, as compared with relative risk reduction of 50%-95% and 58%-100%. NNV to prevent one symptomatic infection and one hospitalisation was in the range of 80-500 and 500-4000. Based on available data, ARI and NNH as measures of harm were difficult to calculate, and the balance between benefits and harms using EBM measures remained uncertain. The effectiveness of COVID-19 vaccines as measured by ARR and NNV was substantially higher in population subgroups with high versus low baseline risks.

CONCLUSIONS

Priorities for vaccine distribution should target subpopulations with higher baseline risks. Similar analyses using ARR/NNV and ARI/NNH would strengthen evaluations of vaccines' benefits versus harms. An EBM perspective on vaccine distribution that emphasises baseline risks becomes especially important as the world's population continues to face major barriers to vaccine access-sometimes termed 'vaccine apartheid'.

Street-view greenspace exposure and objective sleep characteristics among children

Greenspace may benefit sleep by enhancing physical activity, reducing stress or air pollution exposure. Studies on greenspace and children's sleep are limited, and most use satellite-derived measures that do not capture ground-level exposures that may be important for sleep. We examined associations of street view imagery (SVI)-based greenspace with sleep in Project Viva, a Massachusetts pre-birth cohort. We used deep learning algorithms to derive novel metrics of greenspace (e.g., %trees, %grass) from SVI within 250m of participant residential addresses during 2007-2010 (mid-childhood, mean age 7.9 years) and 2012-2016 (early adolescence, 13.2y) (N = 533). In early adolescence, participants completed >5 days of wrist actigraphy. Sleep duration, efficiency, and time awake after sleep onset (WASO) were derived from actigraph data. We used linear regression to examine cross-sectional and prospective associations of mid-childhood and early adolescence greenspace exposure with early adolescence sleep, adjusting for confounders. We compared associations with satellite-based greenspace (Normalized Difference Vegetation Index, NDVI). In unadjusted models, mid-childhood SVI-based total greenspace and %trees (per interquartile range) were associated with longer sleep duration at early adolescence (9.4 min/day; 95%CI:3.2,15.7; 8.1; 95%CI:1.7,14.6 respectively). However, in fully adjusted models, only the association between %grass at mid-childhood and WASO was observed (4.1; 95%CI:0.2,7.9). No associations were observed between greenspace and sleep efficiency, nor in cross-sectional early adolescence models. The association between greenspace and sleep differed by racial and socioeconomic subgroups. For example, among Black participants, higher NDVI was associated with better sleep, in neighborhoods with low socio-economic status (SES), higher %grass was associated with worse sleep, and in neighborhoods with high SES, higher total greenspace and %grass were associated with better sleep time. SVI metrics may have the potential to identify specific features of greenspace that affect sleep.

Bring Your Own Location Data: Use of Google Smartphone Location History Data for Environmental Health Research

BACKGROUND

Environmental exposures are commonly estimated using spatial methods, with most epidemiological studies relying on home addresses. Passively collected smartphone location data, like Google Location History (GLH) data, may present an opportunity to integrate existing long-term time-activity data.

OBJECTIVES

We aimed to evaluate the potential use of GLH data for capturing long-term retrospective time-activity data for environmental health research.

METHODS

We included 378 individuals who participated in previous Global Positioning System (GPS) studies within the Washington State Twin Registry. GLH data consists of location information that has been routinely collected since 2010 when location sharing was enabled within android operating systems or Google apps. We created instructions for participants to download their GLH data and provide it through secure data transfer. We summarized the GLH data provided, compared it to available GPS data, and conducted an exposure assessment for nitrogen dioxide (NO2) air pollution.

RESULTS

Of 378 individuals contacted, we received GLH data from 61 individuals (16.1%) and 53 (14.0%) indicated interest but did not have historical GLH data available. The provided GLH data spanned 2010-2021 and included 34 million locations, capturing 66,677 participant days. The median number of days with GLH data per participant was 752, capturing 442 unique locations. When we compared GLH data to 2-wk GPS data (∼1.8 million points), 95% of GPS time-activity points were within 100m of GLH locations. We observed important differences between NO2 exposures assigned at home locations compared with GLH locations, highlighting the importance of GLH data to environmental exposure assessment.

DISCUSSION

We believe collecting GLH data is a feasible and cost-effective method for capturing retrospective time-activity patterns for large populations that presents new opportunities for environmental epidemiology. Cohort studies should consider adding GLH data collection to capture historical time-activity patterns of participants, employing a "bring-your-own-location-data" citizen science approach. Privacy remains a concern that needs to be carefully managed when using GLH data. https://doi.org/10.1289/EHP10829.

Measuring and modelling perceptions of the built environment for epidemiological research using crowd-sourcing and image-based deep learning models

BACKGROUND

Perceptions of the built environment, such as nature quality, beauty, relaxation, and safety, may be key factors linking the built environment to human health. However, few studies have examined these types of perceptions due to the difficulty in quantifying them objectively in large populations.

OBJECTIVE

To measure and predict perceptions of the built environment from street-view images using crowd-sourced methods and deep learning models for application in epidemiologic studies.

METHODS

We used the Amazon Mechanical-Turk crowdsourcing platform where participants compared two street-view images and quantified perceptions of nature quality, beauty, relaxation, and safety. We optimized street-view image sampling methods to improve the quality and resulting perception data specific to participants enrolled in the Washington State Twin Registry (WSTR) health study. We used a transfer learning approach to train deep learning models by leveraging existing image perception data from the PlacePulse 2.0 dataset, which includes 1.1 million image comparisons, and refining based on new WSTR perception data. Resulting models were applied to WSTR addresses to estimate exposures and evaluate associations with traditional built environment measures.

RESULTS

We collected over 36,000 image comparisons and calculated perception measures for each image. Our final deep learning models explained 77.6% of nature quality, 68.1% of beauty, 72.0% of relaxation, and 64.7% of safety in pairwise image comparisons. Applying transfer learning with the new perception labels specific to the WSTR yielded an average improvement of 3.8% for model performance. Perception measures were weakly to moderately correlated with traditional built environment exposures for WSTR participant addresses; for example, nature quality and NDVI (r = 0.55), neighborhood area deprivation (r = -0.16), and walkability (r = -0.20), respectively.

SIGNIFICANCE

We were able to measure and model perceptions of the built environment optimized for a specific health study. Future applications will examine associations between these exposure measures and mental health in the WSTR.

IMPACT STATEMENT

Built environments influence health through complex pathways. Perceptions of nature quality, beauty, relaxation and safety may be particularly import for understanding these linkages, but few studies to-date have examined these perceptions objectively for large populations. For quantitative research, an exposure measure must be reproducible, accurate, and precise--here we work to develop such measures for perceptions of the urban environment. We created crowd-sourced and image-based deep learning methods that were able to measure and model these perceptions. Future applications will apply these models to examine associations with mental health in the Washington State Twin Registry.

Long-term trends in urban NO2 concentrations and associated paediatric asthma incidence: estimates from global datasets

BACKGROUND

Combustion-related nitrogen dioxide (NO₂) air pollution is associated with paediatric asthma incidence. We aimed to estimate global surface NO₂ concentrations consistent with the Global Burden of Disease study for 1990-2019 at a 1 km resolution, and the concentrations and attributable paediatric asthma incidence trends in 13 189 cities from 2000 to 2019.

METHODS

We scaled an existing annual average NO₂ concentration dataset for 2010-12 from a land use regression model (based on 5220 NO₂ monitors in 58 countries and land use variables) to other years using NO₂ column densities from satellite and reanalysis datasets. We applied these concentrations in an epidemiologically derived concentration-response function with population and baseline asthma rates to estimate NO₂-attributable paediatric asthma incidence.

FINDINGS

We estimated that 1·85 million (95% uncertainty interval [UI] 0·93-2·80 million) new paediatric asthma cases were attributable to NO₂ globally in 2019, two thirds of which occurred in urban areas (1·22 million cases; 95% UI 0·60-1·8 million). The proportion of paediatric asthma incidence that is attributable to NO₂ in urban areas declined from 19·8% (1·22 million attributable cases of 6·14 million total cases) in 2000 to 16·0% (1·24 million attributable cases of 7·73 million total cases) in 2019. Urban attributable fractions dropped in high-income countries (-41%), Latin America and the Caribbean (-16%), central Europe, eastern Europe, and central Asia (-13%), and southeast Asia, east Asia, and Oceania (-6%), and rose in south Asia (+23%), sub-Saharan Africa (+11%), and north Africa and the Middle East (+5%). The contribution of NO₂ concentrations, paediatric population size, and asthma incidence rates to the change in NO₂-attributable paediatric asthma incidence differed regionally.

INTERPRETATION

Despite improvements in some regions, combustion-related NO₂ pollution continues to be an important contributor to paediatric asthma incidence globally, particularly in cities. Mitigating air pollution should be a crucial element of public health strategies for children.

FUNDING

Health Effects Institute, NASA.

Associations of outdoor fine particulate air pollution and cardiovascular disease in 157 436 individuals from 21 high-income, middle-income, and low-income countries (PURE): a prospective cohort study

BACKGROUND

Most studies of long-term exposure to outdoor fine particulate matter (PM_2·5) and cardiovascular disease are from high-income countries with relatively low PM_2·5 concentrations. It is unclear whether risks are similar in low-income and middle-income countries (LMICs) and how outdoor PM_2·5 contributes to the global burden of cardiovascular disease. In our analysis of the Prospective Urban and Rural Epidemiology (PURE) study, we aimed to investigate the association between long-term exposure to PM_2·5 concentrations and cardiovascular disease in a large cohort of adults from 21 high-income, middle-income, and low-income countries.

METHODS

In this multinational, prospective cohort study, we studied 157 436 adults aged 35-70 years who were enrolled in the PURE study in countries with ambient PM_2·5 estimates, for whom follow-up data were available. Cox proportional hazard frailty models were used to estimate the associations between long-term mean community outdoor PM_2·5 concentrations and cardiovascular disease events (fatal and non-fatal), cardiovascular disease mortality, and other non-accidental mortality.

FINDINGS

Between Jan 1, 2003, and July 14, 2018, 157 436 adults from 747 communities in 21 high-income, middle-income, and low-income countries were enrolled and followed up, of whom 140 020 participants resided in LMICs. During a median follow-up period of 9·3 years (IQR 7·8-10·8; corresponding to 1·4 million person-years), we documented 9996 non-accidental deaths, of which 3219 were attributed to cardiovascular disease. 9152 (5·8%) of 157 436 participants had cardiovascular disease events (fatal and non-fatal incident cardiovascular disease), including 4083 myocardial infarctions and 4139 strokes. Mean 3-year PM_2·5 at cohort baseline was 47·5 μg/m³ (range 6-140). In models adjusted for individual, household, and geographical factors, a 10 μg/m³ increase in PM_2·5 was associated with increased risk for cardiovascular disease events (hazard ratio 1·05 [95% CI 1·03-1·07]), myocardial infarction (1·03 [1·00-1·05]), stroke (1·07 [1·04-1·10]), and cardiovascular disease mortality (1·03 [1·00-1·05]). Results were similar for LMICs and communities with high PM_2·5 concentrations (>35 μg/m³). The population attributable fraction for PM_2·5 in the PURE cohort was 13·9% (95% CI 8·8-18·6) for cardiovascular disease events, 8·4% (0·0-15·4) for myocardial infarction, 19·6% (13·0-25·8) for stroke, and 8·3% (0·0-15·2) for cardiovascular disease mortality. We identified no consistent associations between PM_2·5 and risk for non-cardiovascular disease deaths.

INTERPRETATION

Long-term outdoor PM_2·5 concentrations were associated with increased risks of cardiovascular disease in adults aged 35-70 years. Air pollution is an important global risk factor for cardiovascular disease and a need exists to reduce air pollution concentrations, especially in LMICs, where air pollution levels are highest.

FUNDING

Full funding sources are listed at the end of the paper (see Acknowledgments).

Development of an environmental health tool linking chemical exposures, physical location and lung function

BACKGROUND

A challenge in environmental health research is collecting robust data sets to facilitate comparisons between personal chemical exposures, the environment and health outcomes. To address this challenge, the Exposure, Location and lung Function (ELF) tool was designed in collaboration with communities that share environmental health concerns. These concerns centered on respiratory health and ambient air quality. The ELF collects exposure to polycyclic aromatic hydrocarbons (PAHs), given their association with diminished lung function. Here, we describe the ELF as a novel environmental health assessment tool.

METHODS

The ELF tool collects chemical exposure for 62 PAHs using passive sampling silicone wristbands, geospatial location data and respiratory lung function measures using a paired hand-held spirometer. The ELF was tested by 10 individuals with mild to moderate asthma for 7 days. Participants wore a wristband each day to collect PAH exposure, carried a cell phone, and performed spirometry daily to collect respiratory health measures. Location data was gathered using the geospatial positioning system technology in an Android cell-phone.

RESULTS

We detected and quantified 31 PAHs across the study population. PAH exposure data showed spatial and temporal sensitivity within and between participants. Location data was used with existing datasets such as the Toxics Release Inventory and the National Oceanic and Atmospheric Administration (NOAA) Hazard Mapping System. Respiratory health outcomes were validated using criteria from the American Thoracic Society with 94% of participant data meeting standards. Finally, the ELF was used with a high degree of compliance (> 90%) by community members.

CONCLUSIONS

The ELF is a novel environmental health assessment tool that allows for personal data collection spanning chemical exposures, location and lung function measures as well as self-reported information.

Evaluating street view exposure measures of visible green space for health research

Urban green space, or natural environments, are associated with multiple physical and mental health outcomes. Several proposed pathways of action for these benefits (e.g., stress reduction and attention restoration) require visual perception of green space; however, existing green space exposure measures commonly used in epidemiological studies do not capture street-scale exposures. We downloaded 254 Google Street View (GSV) panorama images from Portland, Oregon and calculated percent of green in each image, called Green View Index (GVI). For these locations we also calculated satellite-based normalized difference vegetation index (NDVI), % tree cover, % green space, % street tree buffering, distance to parks, and several neighborhood socio-economic variables. Correlations between the GVI and other green space measures were low (-0.02 to 0.50), suggesting GSV-based measures captured unique information about green space exposures. We further developed a GVI:NDVI ratio, which was associated with the amount of vertical green space in an image. The GVI and GVI:NDVI ratio were weakly related to neighborhood socioeconomic status and are therefore less susceptible to confounding in health studies compared to other green space measures. GSV measures captured unique characteristics of the green space environment and offer a new approach to examine green space and health associations in epidemiological research.

Health Effects of Household Solid Fuel Use: Findings from 11 Countries within the Prospective Urban and Rural Epidemiology Study

BACKGROUND

Household air pollution (HAP) from solid fuel use for cooking affects 2.5 billion individuals globally and may contribute substantially to disease burden. However, few prospective studies have assessed the impact of HAP on mortality and cardiorespiratory disease.

OBJECTIVES

Our goal was to evaluate associations between HAP and mortality, cardiovascular disease (CVD), and respiratory disease in the prospective urban and rural epidemiology (PURE) study.

METHODS

We studied 91,350 adults 35–70 y of age from 467 urban and rural communities in 11 countries (Bangladesh, Brazil, Chile, China, Colombia, India, Pakistan, Philippines, South Africa, Tanzania, and Zimbabwe). After a median follow-up period of 9.1 y, we recorded 6,595 deaths, 5,472 incident cases of CVD (CVD death or nonfatal myocardial infarction, stroke, or heart failure), and 2,436 incident cases of respiratory disease (respiratory death or nonfatal chronic obstructive pulmonary disease, pulmonary tuberculosis, pneumonia, or lung cancer). We used Cox proportional hazards models adjusted for individual, household, and community-level characteristics to compare events for individuals living in households that used solid fuels for cooking to those using electricity or gas.

RESULTS

We found that 41.8% of participants lived in households using solid fuels as their primary cooking fuel. Compared with electricity or gas, solid fuel use was associated with fully adjusted hazard ratios of 1.12 (95% CI: 1.04, 1.21) for all-cause mortality, 1.08 (95% CI: 0.99, 1.17) for fatal or nonfatal CVD, 1.14 (95% CI: 1.00, 1.30) for fatal or nonfatal respiratory disease, and 1.12 (95% CI: 1.06, 1.19) for mortality from any cause or the first incidence of a nonfatal cardiorespiratory outcome. Associations persisted in extensive sensitivity analyses, but small differences were observed across study regions and across individual and household characteristics.

DISCUSSION

Use of solid fuels for cooking is a risk factor for mortality and cardiorespiratory disease. Continued efforts to replace solid fuels with cleaner alternatives are needed to reduce premature mortality and morbidity in developing countries. https://doi.org/10.1289/EHP3915.

Residential green space and pathways to term birth weight in the Canadian Healthy Infant Longitudinal Development (CHILD) Study

Background

A growing number of studies observe associations between the amount of green space around a mother’s home and positive birth outcomes; however, the robustness of this association and potential pathways of action remain unclear.

Objectives

To examine associations between mother’s residential green space and term birth weight within the Canadian Healthy Infant Longitudinal Development (CHILD) study and examine specific hypothesized pathways.

Methods

We examined 2510 births located in Vancouver, Edmonton, Winnipeg, and Toronto Canada. Green space was estimated around mother’s residences during pregnancy using Landsat 30 m normalized difference vegetation index (NDVI). We examined hypothesized pathways of: (1) reduction of environmental exposure; (2) built environment features promoting physical activity; (3) psychosocial conditions; and (4) psychological influences. Linear regression was used to assess associations between green space and term birth weight adjusting first for a comprehensive set of confounding factors and then incrementally for pathway variables.

Results

Fully adjusted models showed non-statistically significant increases in term birth weight with increasing green space. For example, a 0.1 increase in NDVI within 500 m was associated with a 21.5 g (95% CI − 4.6, 47.7) increase in term birth weight. Associations varied by city and were most robust for high-density locations. For the two largest cities (Vancouver and Toronto), we observed an increase in birth weight of 41.2 g (95% CI 7.8, 74.6) for a 0.1 increase in NDVI within 500 m. We did not observe substantial reductions in the green space effect on birth weight when adjusting for pathway variables.

Conclusion

Our results highlight the need to further characterize the interactions between green space, urban density and climate related factors as well as the pathways linking residential green space to birth outcomes.

Engaging stakeholders in research to address water-energy-food (WEF) nexus challenges

The water-energy-food (WEF) nexus has become a popular, and potentially powerful, frame through which to analyse interactions and interdependencies between these three systems. Though the case for transdisciplinary research in this space has been made, the extent of stakeholder engagement in research remains limited with stakeholders most commonly incorporated in research as end-users. Yet, stakeholders interact with nexus issues in a variety of ways, consequently there is much that collaboration might offer to develop nexus research and enhance its application. This paper outlines four aspects of nexus research and considers the value and potential challenges for transdisciplinary research in each. We focus on assessing and visualising nexus systems; understanding governance and capacity building; the importance of scale; and the implications of future change. The paper then proceeds to describe a novel mixed-method study that deeply integrates stakeholder knowledge with insights from multiple disciplines. We argue that mixed-method research designs-in this case orientated around a number of cases studies-are best suited to understanding and addressing real-world nexus challenges, with their inevitable complex, non-linear system characteristics. Moreover, integrating multiple forms of knowledge in the manner described in this paper enables research to assess the potential for, and processes of, scaling-up innovations in the nexus space, to contribute insights to policy and decision making.

Towards Personal Exposures: How Technology Is Changing Air Pollution and Health Research

PURPOSE OF REVIEW

We present a review of emerging technologies and how these can transform personal air pollution exposure assessment and subsequent health research.

RECENT FINDINGS

Estimating personal air pollution exposures is currently split broadly into methods for modeling exposures for large populations versus measuring exposures for small populations. Air pollution sensors, smartphones, and air pollution models capitalizing on big/new data sources offer tremendous opportunity for unifying these approaches and improving long-term personal exposure prediction at scales needed for population-based research. A multi-disciplinary approach is needed to combine these technologies to not only estimate personal exposures for epidemiological research but also determine drivers of these exposures and new prevention opportunities. While available technologies can revolutionize air pollution exposure research, ethical, privacy, logistical, and data science challenges must be met before widespread implementations occur. Available technologies and related advances in data science can improve long-term personal air pollution exposure estimates at scales needed for population-based research. This will advance our ability to evaluate the impacts of air pollution on human health and develop effective prevention strategies.

Global Land Use Regression Model for Nitrogen Dioxide Air Pollution

Nitrogen dioxide is a common air pollutant with growing evidence of health impacts independent of other common pollutants such as ozone and particulate matter. However, the worldwide distribution of NO₂ exposure and associated impacts on health is still largely uncertain. To advance global exposure estimates we created a global nitrogen dioxide (NO₂) land use regression model for 2011 using annual measurements from 5,220 air monitors in 58 countries. The model captured 54% of global NO₂ variation, with a mean absolute error of 3.7 ppb. Regional performance varied from R² = 0.42 (Africa) to 0.67 (South America). Repeated 10% cross-validation using bootstrap sampling (n = 10,000) demonstrated a robust performance with respect to air monitor sampling in North America, Europe, and Asia (adjusted R² within 2%) but not for Africa and Oceania (adjusted R² within 11%) where NO₂ monitoring data are sparse. The final model included 10 variables that captured both between and within-city spatial gradients in NO₂ concentrations. Variable contributions differed between continental regions, but major roads within 100 m and satellite-derived NO₂ were consistently the strongest predictors. The resulting model can be used for global risk assessments and health studies, particularly in countries without existing NO₂ monitoring data or models.

Associations between residential greenness and birth outcomes across Texas

BACKGROUND

The amount of greenness around mothers' residences has been associated with positive birth outcomes; however, findings are inconclusive. Here we examine residential greenness and birth outcomes in a population-based birth cohort in Texas, a state with large regional variation in greenness levels, several distinct cities, and a diverse population.

METHODS

We used Vital Statistics data to create a birth cohort (n=3,026,603) in Texas from 2000 to 2009. Greenness exposure measures were estimated from full residential addresses across nine months of pregnancy, and each trimester specifically, using the mean of corresponding MODIS satellite 16-day normalized difference vegetation index (NDVI) surfaces at a 250m resolution, which have not been previously used. Logistic and linear mixed models were used to determine associations with preterm birth, small for gestational age (SGA) and term birth weight, controlling for individual and neighborhood factors.

RESULTS

Unadjusted results demonstrated consistent protective effects of residential greenness on adverse birth outcomes for all of Texas and the four largest cities (Houston, San Antonio, Dallas, and Austin). However, in fully adjusted models these effects almost completely disappeared. For example, mothers with the highest (>0.52) compared to the lowest (<0.37) NDVI quartiles had a 24.4g (95% CI: 22.7, 26.1) increase in term birth weight in unadjusted models, which was attenuated to 1.9g (95% CI: 0.1, 3.7) in fully adjusted models. Maternal and paternal race, ethnicity and education had the largest impact on reducing associations. Trimester-specific greenness exposures showed similar results to nine-month average exposures. Some evidence was seen for protective effects of greenness for Hispanics, mothers with low education and mothers living in low income neighborhoods.

CONCLUSIONS

In this large population-based study, across multiple urban areas in Texas and diverse populations, we did not observe consistent associations between residential greenness and birth outcomes.

Relationships between Changes in Urban Characteristics and Air Quality in East Asia from 2000 to 2010

Characteristics of urban areas, such as density and compactness, are associated with local air pollution concentrations. The potential for altering air pollution through changing urban characteristics, however, is less certain, especially for expanding cities within the developing world. We examined changes in urban characteristics from 2000 to 2010 for 830 cities in East Asia to evaluate associations with changes in nitrogen dioxide (NO2) and fine particulate matter (PM2.5) air pollution. Urban areas were stratified by population size into small (100 000-250 000), medium, (250 000-1 000 000), and large (>1 000 000). Multivariate regression models including urban baseline characteristics, meteorological variables, and change in urban characteristics explained 37%, 49%, and 54% of the change in NO2 and 29%, 34%, and 37% of the change in PM2.5 for small, medium and large cities, respectively. Change in lights at night strongly predicted change in NO2 and PM2.5, while urban area expansion was strongly associated with NO2 but not PM2.5. Important differences between changes in urban characteristics and pollutant levels were observed by city size, especially NO2. Overall, changes in urban characteristics had a greater impact on NO2 and PM2.5 change than baseline characteristics, suggesting urban design and land use policies can have substantial impacts on local air pollution levels.

Developing a smartphone software package for predicting atmospheric pollutant concentrations at mobile locations

There is considerable evidence that exposure to air pollution is harmful to health. In the U.S., ambient air quality is monitored by Federal and State agencies for regulatory purposes. There are limited options, however, for people to access this data in real-time which hinders an individual's ability to manage their own risks. This paper describes a new software package that models environmental concentrations of fine particulate matter (PM_2.5), coarse particulate matter (PM₁₀), and ozone concentrations for the state of Oregon and calculates personal health risks at the smartphone's current location. Predicted air pollution risk levels can be displayed on mobile devices as interactive maps and graphs color-coded to coincide with EPA air quality index (AQI) categories. Users have the option of setting air quality warning levels via color-coded bars and were notified whenever warning levels were exceeded by predicted levels within 10 km. We validated the software using data from participants as well as from simulations which showed that the application was capable of identifying spatial and temporal air quality trends. This unique application provides a potential low-cost technology for reducing personal exposure to air pollution which can improve quality of life particularly for people with health conditions, such as asthma, that make them more susceptible to these hazards.

Metabolism and pharmacokinetics of the anti-tuberculosis drug ethionamide in a flavin-containing monooxygenase null mouse

Multiple drug resistance (MDR) in Mycobacterium tuberculosis (mTB), the causative agent for tuberculosis (TB), has led to increased use of second-line drugs, including ethionamide (ETA). ETA is a prodrug bioactivated by mycobacterial and mammalian flavin-containing monooxygenases (FMOs). FMO2 is the major isoform in the lungs of most mammals, including primates. In humans a polymorphism exists in the expression of FMO2. FMO2.2 (truncated, inactive) protein is produced by the common allele, while the ancestral allele, encoding active FMO2.1, has been documented only in individuals of African and Hispanic origin, at an incidence of up to 50% and 7%, respectively. We hypothesized that FMO2 variability in TB-infected individuals would yield differences in concentrations and ratios of ETA prodrug and metabolites. In this study we assessed the impact of the FMO2 genetic polymorphism on the pharmacokinetics of ETA after administration of a single oral dose of ETA (125 mg/kg) to wild type and triple Fmo1/2/4-null mice, measuring levels of prodrug vs. metabolites in plasma collected from 0 to 3.5 h post-gavage. All mice metabolized ETA to ETA S-oxide (ETASO) and 2-ethyl-4-amidopyridine (ETAA). Wild type mice had higher plasma concentrations of metabolites than of parent compound (p = 0.001). In contrast, Fmo1/2/4-null mice had higher plasma concentrations of parent compound than of metabolites (p = 0.0001). Thus, the human FMO2 genotype could impact the therapeutic efficacy and/or toxicity of ETA.

Application of a fuzzy neural network model in predicting polycyclic aromatic hydrocarbon-mediated perturbations of the Cyp1b1 transcriptional regulatory network in mouse skin

Polycyclic aromatic hydrocarbons (PAHs) are present in the environment as complex mixtures with components that have diverse carcinogenic potencies and mostly unknown interactive effects. Non-additive PAH interactions have been observed in regulation of cytochrome P450 (CYP) gene expression in the CYP1 family. To better understand and predict biological effects of complex mixtures, such as environmental PAHs, an 11 gene input-1 gene output fuzzy neural network (FNN) was developed for predicting PAH-mediated perturbations of dermal Cyp1b1 transcription in mice. Input values were generalized using fuzzy logic into low, medium, and high fuzzy subsets, and sorted using k-means clustering to create Mamdani logic functions for predicting Cyp1b1 mRNA expression. Model testing was performed with data from microarray analysis of skin samples from FVB/N mice treated with toluene (vehicle control), dibenzo[def,p]chrysene (DBC), benzo[a]pyrene (BaP), or 1 of 3 combinations of diesel particulate extract (DPE), coal tar extract (CTE) and cigarette smoke condensate (CSC) using leave-one-out cross-validation. Predictions were within 1 log(2) fold change unit of microarray data, with the exception of the DBC treatment group, where the unexpected down-regulation of Cyp1b1 expression was predicted but did not reach statistical significance on the microarrays. Adding CTE to DPE was predicted to increase Cyp1b1 expression, whereas adding CSC to CTE and DPE was predicted to have no effect, in agreement with microarray results. The aryl hydrocarbon receptor repressor (Ahrr) was determined to be the most significant input variable for model predictions using back-propagation and normalization of FNN weights.

Exercise in the community for people with minimal gait impairment due to MS: an assessor-blind randomized controlled trial

Background:

While there is an increasing body of evidence supporting the efficacy of exercise in people with multiple sclerosis (MS), additional information on the effectiveness of combining aerobic and resistance training, and yoga is required.

Objectives:

This study evaluated the effectiveness of community exercise interventions for people with MS having minimal gait impairment.

Methods:

A multi-centred, block-randomised, assessor-blinded, controlled trial was conducted. Participants were randomised in groups of eight to physiotherapist (PT)-led exercise ( n = 80), yoga ( n = 77), fitness instructor (FI)-led exercise ( n = 86) and they took part in weekly community-based group exercise sessions. Those in the control group were asked not to change of their exercise habits ( n = 71). The primary outcome was the Multiple Sclerosis Impact Scale (MSIS) 29v2 physical component, measured before and after the 10-week intervention. Secondary outcomes were the MSIS 29v2 psychological component, the Modified Fatigue Impact Scale (MFIS) and the 6-Minute Walk Test (6MWT).

Results:

The group x time interaction approached significance for the MSIS-29v2 physical component ( f = 2.48, p = 0.061) and MFIS total ( f = 2.50, p = 0.06), and it was significant for the MFIS physical subscale ( f = 4.23, p = 0.006). All three exercise interventions led to a statistically significant improvement on the MSIS-29 psychological component and both the MFIS total and physical subscales, which were greater than the control ( p < 0.05). Only the PT-led and FI-led interventions significantly improved the MSIS-29 physical and 6MWT to levels greater than the control ( p < 0.05).

Conclusions:

This study provides evidence for the positive effect of exercise on the physical impact of MS and fatigue. The group nature of the classes may have contributed to the positive effects seen on the psychological impact of MS.

Polycyclic aromatic hydrocarbons as skin carcinogens: comparison of benzo[a]pyrene, dibenzo[def,p]chrysene and three environmental mixtures in the FVB/N mouse

The polycyclic aromatic hydrocarbon (PAH), benzo[a]pyrene (BaP), was compared to dibenzo[def,p]chrysene (DBC) and combinations of three environmental PAH mixtures (coal tar, diesel particulate and cigarette smoke condensate) using a two stage, FVB/N mouse skin tumor model. DBC (4nmol) was most potent, reaching 100% tumor incidence with a shorter latency to tumor formation, less than 20 weeks of 12-O-tetradecanoylphorbol-13-acetate (TPA) promotion compared to all other treatments. Multiplicity was 4 times greater than BaP (400 nmol). Both PAHs produced primarily papillomas followed by squamous cell carcinoma and carcinoma in situ. Diesel particulate extract (1 mg SRM 1650b; mix 1) did not differ from toluene controls and failed to elicit a carcinogenic response. Addition of coal tar extract (1 mg SRM 1597a; mix 2) produced a response similar to BaP. Further addition of 2 mg of cigarette smoke condensate (mix 3) did not alter the response with mix 2. PAH-DNA adducts measured in epidermis 12 h post initiation and analyzed by ³²P post-labeling, did not correlate with tumor incidence. PAH-dependent alteration in transcriptome of skin 12 h post initiation was assessed by microarray. Principal component analysis (sum of all treatments) of the 922 significantly altered genes (p<0.05), showed DBC and BaP to cluster distinct from PAH mixtures and each other. BaP and mixtures up-regulated phase 1 and phase 2 metabolizing enzymes while DBC did not. The carcinogenicity with DBC and two of the mixtures was much greater than would be predicted based on published Relative Potency Factors (RPFs).

Systemic FasL neutralization increases eosinophilic inflammation in a mouse model of asthma

BACKGROUND

Eosinophils and lymphocytes are pathogenically important in allergic inflammation and sensitive to Fas-mediated apoptosis. Fas ligand (FasL) activity therefore should play a role in regulating the allergic immune response. We aimed to characterize the role of FasL expression in airway eosinophilia in Aspergillus fumigatus (Af)-induced sensitization and to determine whether FasL neutralization alters the inflammatory response.

METHODS

Sensitized Balb/c mice were killed before (day 0) and 1, 7 and 10 days after a single intranasal challenge with Af. Animals received either neutralizing antibody to FasL (clone MFL4) or irrelevant hamster IgG via intraperitoneal injection on days -1 and 5. FasL expression, BAL and tissue inflammatory cell and cytokine profile, and apoptosis were assessed.

RESULTS

Postchallenge FasL gene expression in BAL cells and TUNEL positivity in the airways coincided with the height of inflammatory cell influx on day 1, while soluble FasL protein was released on day 7, preceding resolution of the inflammatory changes. Although eosinophil numbers showed a negative correlation with soluble FasL levels in the airways, MBP(+) eosinophils remained TUNEL negative in the submucosal tissue, throughout the 10-day period after Af challenge. Systemic FasL neutralization significantly enhanced BAL and tissue eosinophil counts. This effect was associated with increased activation of T cells and release of IL-5, IL-9, and GM-CSF in the BAL fluid of mice, indicating an involvement of pro-eosinophilic survival pathways.

CONCLUSIONS

FasL activity may play an active role in resolving eosinophilic inflammation through regulating T cells and pro-eosinophilic cytokine release during the allergic airway response.

Substituted N-{3-[(1,1-dioxido-1,2-benzothiazol-3-yl)(phenyl)amino]propyl}benzamide analogs as potent Kv1.3 ion channel blockers. Part 2

We report the synthesis and in vitro activity of a series of novel substituted N-{3-[(1,1-dioxido-1,2-benzothiazol-3-yl)(phenyl)amino]propyl}benzamide analogs. These analogs showed potent inhibitory activity against Kv1.3. Several demonstrated similar potency to the known Kv1.3 inhibitor PAP-1 when tested under the IonWorks patch clamp assay conditions. Two compounds 13i and 13rr were advanced further as potential tool compounds for in vivo validation studies.

Development of training syllabi for radiation protection and quality assurance of dual-energy X-ray absorptiometry (DXA) systems

The use of dual-energy X-ray absorptiometry (DXA) scanners for measuring bone mineral density (BMD) is on the increase. A single DXA scan is a relatively low-dose diagnostic X-ray examination; however, radiation protection (RP) issues should not be trivialised. One objective of the EU 6th Framework SENTINEL co-ordination action was to develop training syllabi in RP and quality assurance (QA) for BMD, and this study presents the results. An EU-wide survey was carried out which confirmed that there was a need for an accredited DXA RP training course in many EU states. There is also limited published guidance on acceptance testing/QA for DXA. Two training syllabi were developed: one on RP and one on QA of DXA systems. A training course was delivered in Ireland in 2006 by the Medical Physics & Bioengineering Department of St James's Hospital, Dublin. Following the training course, a PC-based training CD was developed and will be made available. A harmonised approach to training will promote consistent approaches to radiation safety across the EU.

QA/acceptance testing of DEXA X-ray systems used in bone mineral densitometry

New developments in dual energy X-ray absorptiometry (DEXA) imaging technology [fan beam and cone beam (CB)] result in higher exposure levels, shorter scan times, increased patient throughput and increased shielding requirements. This study presents the results of a European survey detailing the number and location of DEXA systems in SENTINEL partner states and the QA (quality assurance) currently performed by physicists and operators in these centres. The results of a DEXA equipment survey based on an in-house developed QA protocol are presented. Measurements show that the total effective dose to the patient from a spine and dual femur DEXA examination on the latest generation DEXA systems is comparable with a few microSv at most. Scatter measurements showed that the use of a mobile lead screen for staff protection was necessary for fan and CB systems. Scattered dose from newer generation systems may also exceed the exposure limits for the general public so structural shielding may also be required. Considerable variation in the magnitude and annual repeatability of half value layer was noted between different models of DEXA scanners. A comparative study of BMD (bone mineral density) accuracy using the European Spine Phantom highlighted a deviation of up to 7% in BMD values between scanners of different manufacturers.

Acceptance testing and routine quality control in general radiography: mobile units and film/screen fixed systems

This study presents the findings from acceptance testing and routine quality control (QC) of general radiographic X-ray equipment in Ireland during 2006 and early 2007, including mobile X-ray units and film/screen fixed systems. Acceptance testing and routine QC of the diagnostic X-ray imaging equipment are requirements of European and Irish legislation. One hundred general radiographic X-ray systems were tested within Ireland, 73% of them failed to meet the required QC guidelines, whereby one or more faults were identified. The majority of these failures were minor ones, requiring attention by the suppliers at the next routine service. Significant faults were only identified in seven systems. The suppliers were requested to investigate these issues as soon as possible and take the necessary corrective action. A review of the QC results highlights the need to perform comprehensive acceptance and routine testing of the systems.

Quality assurance of computed and digital radiography systems

Computed radiography (CR) and digital radiography (DR) are replacing traditional film screen radiography as hospitals move towards digital imaging and picture archiving and communication systems (PACS). Both IPEM and KCARE have recently published quality assurance and acceptance testing guidelines for DR. In this paper, the performance of a range of CR and DR systems is compared. Six different manufacturers are included. Particular attention is paid to the performance of the systems under automatic exposure control (AEC). The patient is simulated using a range of thicknesses of tissue equivalent material. Image quality assessment was based on detector assessment protocols and includes pixel value measures as well as subjective assessment using Leeds Test Objects. The protocols for detector assessment cover a broad range of tests and in general detectors (whether DR or CR) performed satisfactorily. The chief limitation in performing these tests was that not all systems provided ready access to pixel values. Subjective tests include the use of the Leeds TO20. As part of this work, suggested reference values are provided to calculate the TO20 image quality factor. One consequence of moving from film screen to digital technologies is that the dynamic range of digital detectors is much wider, and increased exposures are no longer evident from changes in image quality. As such, AEC is a key parameter for CR and DR. Dose was measured using a standard phantom as a basic means of comparing systems. In order to assess the AEC performance, exit doses were also measured while varying phantom thickness. Signal-to-noise ratios (SNRs) were calculated on a number of systems where pixel values were available. SNR was affected by the selection of acquisition protocol. Comparisons between different technologies and collation of data will help refine acceptance thresholds and contribute to optimising dose and image quality.

Patient dose in interventional radiology: a European survey

Patient doses for a few common fluoroscopy-guided procedures in interventional radiology (IR) (excluding cardiology) were collected from a few radiological departments in 13 European countries. The major aim was to evaluate patient doses for the basis of the reference levels. In total, data for 20 procedures for about 1300 patients were collected. There were many-fold variations in the number of IR equipment and procedures per population, in the entrance dose rates, and in the patient dose data (total dose area product or DAP, fluoroscopy time and number of frames). There was no clear correlation between the total DAP and entrance dose rate, or between the total DAP and fluoroscopy time, indicating that a number of parameters affect the differences. Because of the limited number of patients, preliminary reference levels were proposed only for a few procedures. There is a need to improve the optimisation of IR procedures and their definitions and grouping, in order to account for their different complexities.

Acceptance testing and QA of interventional cardiology systems

Interventional cardiology (IC) is a rapidly growing field of medical specialisation. Such procedures are complex and may subject patients and operators to higher levels of risk than those encountered in general radiology. Acceptance testing and quality assurance (QA) of radiological equipment, including IC equipment, is a requirement of the EU Medical Exposures Directive (MED) (97/43/EURATOM). In addition, the MED identifies interventional radiology as an area of special concern. This study presents the results of a survey of 17 IC systems (including several flat panel detector systems) in Irish hospitals. The results of the survey indicate large differences in patient doses between manufacturers for equivalent levels of measured image quality. In addition, all systems were found to have failed one or more acceptance tests, with 60% of systems demonstrating significant problems at acceptance testing. The results of the survey demonstrate the importance of acceptance testing and QA in IC. The results also provide baseline data, which may be used in the development of future QA guidelines.

Acceptance testing of fluoroscopy systems used for interventional purposes

This study presents the results of acceptance testing on 18 interventional fluoroscopy systems in Ireland. Acceptance testing and routine quality assurance (QA) of X-ray systems are the requirements of the EU Medical Exposures Directive (MED) and these requirements were subsequently implemented into Irish legislation. The MED states that special consideration should be given to the QA and dose assessment of high dose procedures such as interventional fluoroscopy. Owing to the advances in fluoroscopy technology, it has been found that comprehensive testing of interventional systems proves challenging in a busy hospital environment. A number of recurrent problems have been identified and are presented.

MDR1/P-glycoprotein and MRP-1 drug efflux pumps in pancreatic carcinoma

BACKGROUND

Pancreatic cancer is one of the most challenging solid organ malignancies. This is due to its aggressiveness, frequent late presentation as advanced disease and chemoresistance. A better understanding of the molecular basis of its drug resistance is needed.

MATERIALS AND METHODS

In this study, the first of its kind, the expression of both MDR1 P-gp and MRP-1 protein in pancreatic tumour specimens was examined by immunohistochemistry. Expression of these drug efflux pumps was examined using semi-quantitative immunohistochemistry according to the percentage of cells within the tumour, demonstrating another staining intencity.

RESULTS

Overall, 93.3% of pancreatic carcinomas expressed MDR1 P-gp, approximately 31% co-expressed MRP-1 with MDR1 P-gp, while 6.7% expressed neither of these proteins.

CONCLUSION

Our results show that drug efflux pumps, in particular that of MDR1 P-gp, are frequently expressed in pancreatic cancer. While a causative role for these efflux pumps in pancreatic cancer chemoresistance cannot necessarily be concluded, the information presented here should be considered when selecting chemotherapy/drug efflux pump inhibitors for future therapies.

MDR1/P-glycoprotein and MRP-1 mRNA and protein expression in non-small cell lung cancer

BACKGROUND

Multiple drug resistance (MDR), both inherent and acquired, is a serious problem in non-small cell lung carcinomas (NSCLC). The purpose of this study was to investigate the prevalence of expression of genes encoding drug efflux pumps, MDR1 and MRP-1, at both the mRNA and protein levels, in this type of cancer.

MATERIALS AND METHODS

Tumour specimens (38 cases) were analysed using immunohistochemistry and, where possible (30 cases), also using reverse-transcriptase polymerase chain reaction.

RESULTS

The results from this analysis indicated that either, or both, drug efflux pumps were frequently expressed in NSCLC. Expression of mrp1 was found to be predominant over mdr1 at the mRNA level, while MDR1 P-gp was more frequently detected than MRP-1 protein. In some cases, proteins encoding pumps were detected without corresponding mRNAs--possibly due to differing sensitivities of the analysis techniques.

CONCLUSION

Future studies of mdr1 and mrp1 using increased-sensitivity qPCR techniques, in parallel with protein analysis, in larger cohorts of cases may help to elucidate the role of drug efflux pumps in NSCLC multiple drug resistance.

A phase I clinical and pharmacokinetic study of the multi-drug resistance protein-1 (MRP-1) inhibitor sulindac, in combination with epirubicin in patients with advanced cancer

PURPOSE

Multi-drug resistance mediated by ATP-binding cassette trans-membrane protein pumps is an important cause of cancer treatment failure. Sulindac has been shown to be a competitive substrate for the clinically important resistance protein, multi-drug resistance protein-1 (MRP-1), and thus might enhance the anti-cancer activity of substrate chemotherapeutic agents, e.g. anthracyclines.

METHODS

We conducted a dose-escalating, single arm, prospective, open label, non-randomised phase I trial of epirubicin (75 mg/m(2)) in combination with escalating oral doses of sulindac (0-800 mg) in patients with advanced cancer to identify an appropriate dose of sulindac to use in future resistance studies. Anthracycline and sulindac pharmacokinetics were studied in cycles 1 and 3.

RESULTS

Seventeen patients (8 breast, 3 lung, 2 bowel, 1 melanoma, 1 renal, 1 ovarian and 1 of unknown primary origin, 16/17 having had prior chemotherapy) were enrolled. Eight patients received a full six cycles of treatment; 14 patients received three or more cycles. Dose-limiting toxicity was observed in two patients at 800 mg sulindac (1 renal impairment, 1 fatal haemoptysis in a patient with advanced lung cancer), and sulindac 600 mg was deemed to be the maximum tolerated dose. Sulindac had no effect on epirubicin pharmacokinetics. Among 15 patients with evaluable tumour, two partial responses were seen (malignant melanoma and breast cancer). Four others had prolonged stable disease.

CONCLUSION

Epirubicin 75 mg/m(2) and sulindac 600 mg are the recommended doses for phase II studies for these agents in combination.

Deterministic weak localization in periodic structures

In some perfect periodic structures classical motion exhibits deterministic diffusion. For such systems we present the weak localization theory. As a manifestation for the velocity autocorrelation function a universal power law decay is predicted to appear at four Ehrenfest times. This deterministic weak localization is robust against weak quenched disorders, which may be confirmed by coherent backscattering measurements of periodic photonic crystals.

Exposure variations under error conditions in automatic exposure controlled film-screen projection radiography

Improper automatic exposure control (AEC) termination may result in high overexposures on some radiographic systems. Under AEC, X-ray factors are adjusted automatically to compensate for differences in patient thickness and density. In radiography, AEC is implemented using ionization chambers placed in the film bucky. In this study we deliberately chose incorrect set-up conditions and assessed the response of the AEC system. Two types of incorrect set-up were studied: (1) incorrect selection of bucky radiation detector and (2) simulated misalignment between the X-ray field and light field. The systems tested varied in age from 1 year to in excess of 10 years. In the first test, overexposures of 90 mGy were recorded. Two systems did not meet EC guidelines for improper AEC termination. The second test, misalignment of the X-ray field, was observed to affect the exposure delivered by approximately +/-22%. The maximum dose increase observed, with a chest phantom in the beam, was 165 microGy. Misalignments also resulted in reduced exposures, which may impact on image quality.

Weak dynamical localization in periodically kicked cold atomic gases

Quantum kicked rotor was recently realized in experiments with cold atomic gases and standing optical waves. As predicted, it exhibits dynamical localization in the momentum space. Here we consider the weak-localization regime concentrating on the Ehrenfest time scale. The latter accounts for the spread time of a minimal wave packet and is proportional to the logarithm of the Planck constant. We show that the onset of the dynamical localization is essentially delayed by four Ehrenfest times, and give quantitative predictions suitable for an experimental verification.

Fibre mapping – a case study

Fibre mapping, more commonly known as one-to-one taping, was developed in Germany approximately twenty years ago. The technique facilitates the distribution of fibres on a surface to be recorded. The impact of this technique on the investigation of serious crime has been reported in the European Fibre Group on several occasions. This paper represents a case study of the application of the technique. It is believed to be the first time that this technique has been successfully applied in the United Kingdom.

Expression and prognostic relevance of Mcl-1 in breast cancer

BACKGROUND

Bcl-2, an anti-apoptotic protein, is frequently associated with favourable prognosis in breast cancer. The potential role of mcl-1, another bcl-2 family member, in breast cancer has not yet been defined.

PATIENTS AND METHODS

This study examined the expression of mcl-1 and bcl-2 in 170 cases of invasive primary breast carcinoma, using reverse-transcriptase polymerase chain reaction and immunohistochemical analyses.

RESULTS

Expression of bcl-2 mRNA and protein were found to be favourably associated with outcome for patients, supporting a prognostic role for bcl-2 in breast cancer, whereas mcl-1 expression, at the mRNA or protein level, did not correlate with tumour size, grade, lymph node or ER status, age of patient at diagnosis, or disease outcome.

CONCLUSION

As these analyses of mcl-1 expression may have co-detected mcl-1(S/deltaTM) (a more recently identified, shorter variant, that may be pro-apoptotic) with the anti-apoptotic wild-type of mcl-1, it is possible that future studies may indicate some significant clinical correlations if the isoforms can be independently investigated.

Lymphoproliferative disease in antibody deficiency: a multi-centre study

We have undertaken a retrospective study of antibody deficient patients, with and without lymphoma, and assessed the ability of specific polymerase chain reaction (PCR) primers to determine if the detection of clonal lymphocyte populations correlates with clinical and immunohistochemical diagnosis of lymphoma. We identified 158 cases with antibody deficiency presenting during the past 20 years. Paraffin-embedded biopsy specimens or slides were available for analysis in a cohort of 34 patients. Of these patients, 29 had common variable immunodeficiency, one X-linked agammaglobulinaemia, one X-linked immunoglobulin deficiency of uncertain cause and three isolated IgG subclass deficiency. We have confirmed that lymphoma in antibody deficiency is predominantly B cell in origin. Clonal lymphocyte populations were demonstrated in biopsies irrespective of histology (16/19 with lymphoma and 11/15 without). Isolated evidence of clonality in biopsy material is therefore an insufficient diagnostic criterion to determine malignancy. Furthermore, our data suggest that clonal expansions are rarely the result of Epstein-Barr virus-driven disease.

A new monoclonal antibody, P2A8(6), that specifically recognizes a novel epitope on the multidrug resistance-associated protein 1 (MRP1), but not on MRP2 nor MRP3

Multidrug resistance (MDR) is a major problem in the chemotherapeutic treatment of cancer. Overexpression of the multidrug resistance-associated protein 1 (MRP1), is associated with MDR in certain tumors. A number of MRP1-specific MAbs, which facilitate both clinical and experimental investigations of this protein, are available. To add to this panel of existing antibodies, we have now generated an additional MRP1-specific monoclonal antibody (MAb), P2A8(6), which detects a unique heat stable epitope on the MRP1 molecule. Female Wistar rats were immunized via footpad injections with a combination of two short synthetic peptides corresponding to amino acids 235-246 (peptide A) and 246-260 (peptide B) of the MRP1 protein. Immune reactive B cells were then isolated from the popliteal lymph nodes for fusion with SP2/O-Ag14 myeloma cells. Resultant hybridoma supernatants were screened for MRP1-specific antibody production. Antibody P2A8(6) was characterized by Western blotting and immunocytochemistry on paired multidrug resistant (MRP1 overexpressing) and sensitive parental cell lines. The antibody detects a protein of 190 kDa in MRP1-expressing cell lines but not in MRP2- or MRP3-transfected cell lines. P2A8(6) stains drug-selected and MRP1-transfected cell lines homogeneously by immunocytochemistry and recognizes MRP1 by immunohistochemistry on formalin-fixed paraffin wax-embedded tissue sections. Peptide inhibition studies confirm that P2A8(6) reacts with peptide B (amino acids 246-260), therefore recognizing a different epitope from that of all currently available MRP1 MAbs. This new MAb, chosen for its specificity to the MRP1 protein, may be a useful addition to the currently available range of MRP1-specific MAbs.