Radioactive seed localization is a safe and effective tool for breast cancer surgery: an evaluation of over 25,000 cases

Radioactive seed localization (RSL) provides a precise and efficient method for removing non-palpable breast lesions. It has proven to be a valuable addition to breast surgery, improving perioperative logistics and patient satisfaction. This retrospective review examines the lessons learned from a high-volume cancer center's RSL program after 10 years of practice and over 25 000 cases. We provide an updated model for assessing the patient's radiation dose from RSL seed implantation and demonstrate the safety of RSL to staff members. Additionally, we emphasize the importance of various aspects of presurgical evaluation, surgical techniques, post-surgical management, and regulatory compliance for a successful RSL program. Notably, the program has reduced radiation exposure for patients and medical staff.

Scoping the Priorities and Concerns of Parents: Infodemiology Study of Posts on Mumsnet and Reddit

BACKGROUND

Health technology innovation is increasingly supported by a bottom-up approach to priority setting, aiming to better reflect the concerns of its intended beneficiaries. Web-based forums provide parents with an outlet to share concerns, advice, and information related to parenting and the health and well-being of their children. They provide a rich source of data on parenting concerns and priorities that could inform future child health research and innovation.

OBJECTIVE

The aim of the study is to identify common concerns expressed on 2 major web-based forums and cluster these to identify potential family health concern topics as indicative priority areas for future research and innovation.

METHODS

We text-mined the r/Parenting subreddit (69,846 posts) and the parenting section of Mumsnet (99,848 posts) to create a large corpus of posts. A generative statistical model (latent Dirichlet allocation) was used to identify the most discussed topics in the corpus, and content analysis was applied to identify the parenting concerns found in a subset of posts.

RESULTS

A model with 25 topics produced the highest coherence and a wide range of meaningful parenting concern topics. The most frequently expressed parenting concerns are related to their child's sleep, self-care, eating (and food), behavior, childcare context, and the parental context including parental conflict. Topics directly associated with infants, such as potty training and bottle feeding, were more common on Mumsnet, while parental context and screen time were more common on r/Parenting.

CONCLUSIONS

Latent Dirichlet allocation topic modeling can be applied to gain a rapid, yet meaningful overview of parent concerns expressed on a large and diverse set of social media posts and used to complement traditional insight gathering methods. Parents framed their concerns in terms of children's everyday health concerns, generating topics that overlap significantly with established family health concern topics. We provide evidence of the range of family health concerns found at these sources and hope this can be used to generate material for use alongside traditional insight gathering methods.

Measurement of the decay of laser-driven linear plasma wakefields

We present measurements of the temporal decay rate of one-dimensional (1D), linear Langmuir waves excited by an ultrashort laser pulse. Langmuir waves with relative amplitudes of approximately 6% were driven by 1.7J, 50fs laser pulses in hydrogen and deuterium plasmas of density n_{e0}=8.4×10^{17}cm^{-3}. The wakefield lifetimes were measured to be τ_{wf}^{H_{2}}=(9±2) ps and τ_{wf}^{D_{2}}=(16±8) ps, respectively, for hydrogen and deuterium. The experimental results were found to be in good agreement with 2D particle-in-cell simulations. In addition to being of fundamental interest, these results are particularly relevant to the development of laser wakefield accelerators and wakefield acceleration schemes using multiple pulses, such as multipulse laser wakefield accelerators.

Benzo[a]pyrene-induced multigenerational changes in gene expression, behavior, and DNA methylation are primarily influenced by paternal exposure

Benzo[a]pyrene (BaP), a polycyclic aromatic hydrocarbon (PAH), is implicated in many developmental and behavioral adverse outcomes in offspring of exposed parents. The objective of this study was to investigate sex-dependent multigenerational effects of preconceptional effects of BaP exposure. Adult wild-type (5D) zebrafish were fed 708 μg BaP/g diet (measured) at a rate of 1% body weight twice/day (14 μg BaP/g fish/day) for 21 days. Fish were spawned using a crossover design, and parental (F0) behavior and reproductive indexes were measured. In offspring, behavioral effects were measured at 96 h post fertilization (hpf) in F1 & F2 larvae, and again when F1s were adults. Compared to controls, there was no significant effect on F0 adult behavior immediately following exposure, but locomotor activity was significantly increased in F1 adults of both sexes. Larval behavior (96 hpf, photomotor response assay) was significantly altered in both the F1 and F2 generations. To assess molecular changes associated with BaP exposure, we conducted transcriptome and DNA methylation profiling in F0 gametes (sperm and eggs) and F1 embryos (10 hpf) from all four crosses. Embryos resulting from the BaP male and control female cross had the most differentially expressed genes (DEGs) and differentially methylated regions (DMRs). Some DMRs were associated with genes encoding chromatin modifying enzymes suggesting regulation of chromatin conformation by DNA methylation. Overall, these results suggest that parental dietary BaP exposure significantly contributes to the multigenerational adverse outcomes.

Physical activity in young children across developmental and health states: the ActiveCHILD study

Background

Evidence about physical activity of young children across developmental and health states is very limited. Using data from an inclusive UK cohort, ActiveCHILD, we investigated relationships between objectively measured physical activity, child development, social context, and health-related quality of life (HRQoL).

Methods

Children (12-36 months), purposively sampled across health pathways, developmental abilities, and sociodemographic factors, were recruited through thirteen National Health Service organisations in England. Data were collected from 07/2017 to 08/2019 on: weekly physical activity (3-7 days) using waist-worn accelerometer (ActiGraph 3GTX); sociodemographics, parent actions, child HRQoL, and child development using questionnaires; and child health conditions using clinical records. A data-driven, unsupervised method, called hidden semi-Markov model (HSMM) segmented the accelerometery data and provided estimates of the total time spent active (any intensity) and very active (greater intensity) for each child. Relationships with the explanatory factors were investigated using multiple linear regression.

Findings

Physical activity data were obtained for 282 children (56% females, mean age 21 months, 37.5% with a health condition) covering all index of multiple deprivation deciles. The patterns of physical activity consisted of two daily peaks, children spending 6.44 (SD = 1.39) hours active (any intensity), of which 2.78 (SD = 1.38) hours very active, 91% meeting WHO guidelines. The model for total time active (any intensity) explained 24% of variance, with mobility capacity the strongest predictor (β = 0.41). The model for time spent very active explained 59% of variance, with mobility capacity again the strongest predictor (β = 0.76). There was no evidence of physical activity explaining HRQoL.

Interpretation

The findings provide new evidence that young children across developmental states regularly achieve mainstream recommended physical activity levels and challenges the belief that children with development problems need lower expectations for daily physical activity compared to peers. Advancing the rights of all children to participate in physical activity requires inclusive, equally ambitious, expectations for all.

Funding

Niina Kolehmainen, HEE/NIHR Integrated Clinical Academic Senior Clinical Lecturer, NIHR ICA-SCL-2015-01-00, was funded by the NIHR for this research project. Christopher Thornton, Olivia Craw, Laura Kudlek, and Laura Cutler were also funded from this award. Tim Rapley is a member of the NIHR Applied Research Collaboration North East and North Cumbria, with part of his time funded through the related award (NIHR200173). The views expressed in this publication are those of the author(s) and not necessarily those of the NIHR, NHS, or the UK Department of Health and Social Care. The work of Kianoush Nazarpour is supported by Engineering and Physical Sciences Research Council (EPSRC), under grant number EP/R004242/2.

Understanding treatment delay: Perceived barriers preventing treatment-seeking for eating disorders

OBJECTIVE

Only a small proportion of individuals with an eating disorder will receive targeted treatment for their illness. The aim of this study was to examine the length of delay to treatment-seeking and determine the barriers preventing earlier access and utilisation of eating disorder treatment for each diagnostic group - anorexia nervosa, bulimia nervosa, binge eating disorder and other specified feeding or eating disorder.

METHOD

Participants were recruited as part of the TrEAT multi-phase consortium study. One hundred and nineteen Australians (13-60 years; 96.9% female) with eating disorders currently accessing outpatient treatment for their illness completed an online survey comprised of self-report measures of eating disorder severity, treatment delay and perceived barriers to treatment-seeking. The treating clinician for each participant also provided additional information (e.g. body mass index and diagnosis).

RESULTS

Overall, the average length of delay between onset of eating disorder symptoms and treatment-seeking was 5.28 years. Controlling for age, latency to treatment-seeking was significantly longer for individuals with bulimia nervosa and binge eating disorder compared to anorexia nervosa. However, when perceived barriers to treatment-seeking were investigated, there were no significant differences between the diagnostic groups in regard to the perceived barriers they experienced. Stigma was rated as the most impactful barrier for each diagnostic group.

CONCLUSION

Findings suggest that individuals with eating disorders face substantial delays in accessing appropriate treatment and that latency to treatment-seeking is often magnified for counter-stereotypical eating disorder presentations. Further research is required to investigate other factors contributing to this delay.

Development of a web-based system to report medication-related adverse effects: a design and usability study (Preprint)

Background

Medicine use is the most common intervention in health care. The frequency with which medicines are used means medication-related problems are very common. One common type of medication-related problems is adverse drug events, which are unintended and harmful effects associated with use of medicines. Reporting of adverse drug events to regulatory authorities is important for evaluation of safety of medicines; however, these adverse effects are frequently unreported due to various factors, including lack of consumer-friendly reporting tools.

Objective

The aim of this study was to develop a user-friendly digital tool for consumers to report medication-related adverse effects.

Methods

The project consisted of 3 parts: (1) content development, including a systematic literature search; (2) iterative system development; and (3) usability testing. The project was guided by participatory design principles, which suggest involving key stakeholders throughout the design process. The first 2 versions were developed as a mobile app and were tested with end users in 2 workshops. The third version was developed as a web application and was tested with consumers who were taking regular medicines. Consumers were asked to complete a modified version of the mHealth app usability questionnaire (MAUQ), an 18-item questionnaire with each item scored using a 7-point Likert scale ranging from 0 (strongly disagree) to 7 (strongly agree). The MAUQ assessed 3 subscales including ease of use (5 items), interface and satisfaction (7 items), and usefulness (6 items). Continuous variables were reported as mean (SD) values, whereas categorical variables were presented as frequencies (percentages). Data analysis was conducted in Microsoft Excel.

Results

The content for the system was based on a systematic literature search and short-listing of questions, followed by feedback from project team members and consumers. Feedback from consumers in the 2 workshops were incorporated to improve the functionality, visual design, and stability of the third (current) version. The third version of the system was tested with 26 consumers. A total of 79% (N=307/390) of all responses on the MAUQ were scored 6 or 7, indicating that users generally strongly agree with the usability of the system. When looking at the individual domains, the system had an average score of 6.3 (SD 0.9) for “ease of use,” 6.3 (SD 0.8) for “interface and satisfaction,” and 5.2 (SD 1.4) for “usefulness.”

Conclusions

The web-based system for medicine adverse effects reporting is a user-friendly tool developed using an iterative participatory design approach. Future research includes further improving the system, particularly the usefulness of the system, as well as testing the scalability and performance of the system in practice.

Emotion Dysregulation and Eating Disorder Symptoms: Examining Distinct Associations and Interactions in Adolescents

Emotion dysregulation has been posited as a key transdiagnostic factor of mental health difficulties, including eating disorders. However, how this transdiagnostic factor interacts with the disorder-specific factor of weight and shape concerns remains unclear. The current study examined whether emotion dysregulation is associated with eating disorder behaviors over and above the association between weight and shape concerns and whether these two factors interacted. The current study used data from two samples, a community sample of high school students (n = 2699), and a clinical sample of adolescents receiving outpatient treatment for an eating disorder (n = 149). Participants completed self-report measures on their eating behaviors, weight/shape concerns, and emotion dysregulation. Findings showed that emotion dysregulation had a unique association with engaging in binge eating and purging (community sample only). Weight and shape concerns were found to have a unique association with engaging in binge eating, fasting, purging, and driven exercise (community sample only). Additionally, weight and shape concerns moderated the association between emotion dysregulation and the probability of engaging in binge eating and driven exercise, whereby the strongest association between emotion dysregulation and these behaviors were observed among adolescents with the lowest levels of weight and shape concerns. Regarding the frequency of eating disorder behaviors, emotion dysregulation had a unique association with severity of binge eating and fasting. Weight and shape concerns were uniquely associated with severity of fasting and driven exercise (community sample only). Findings suggest that emotion dysregulation is a distinct factor of eating disorder behaviors among adolescents.

Differences between Australian adolescents with eating disorder symptoms who are in treatment or not in treatment for an eating disorder

BACKGROUND

Mental health problems frequently occur during adolescence, however, few adolescents seek treatment for these problems, especially for eating disorders. The current study aimed to quantify how adolescents in a clinical sample (ie, those receiving treatment for an eating disorder), differ in terms of psychological factors (eating disorder symptoms and psychological distress), compared to adolescents with eating pathology in a community sample (ie, those not receiving treatment).

METHOD

Data were used from a community sample of adolescents with eating disorder pathology who have not sought treatment (n = 1011) and a clinical sample of adolescents presenting at eating disorder services for treatment (n = 153). Participants reported demographics and completed questionnaires assessing weight/shape concerns, disordered eating and psychological distress.

RESULTS

Adolescents with a lower BMI, more frequent purging and higher weight/shape concerns were more common in the clinical sample, while those engaging in more frequent driven exercise were less common in the clinical sample. The samples did not differ in severity of psychological distress.

CONCLUSIONS

The findings highlight the need for increasing mental health literacy about the role of BMI and driven exercise in eating disorder symptom presentation to increase early detection of these disorders among adolescents.

Meter-scale conditioned hydrodynamic optical-field-ionized plasma channels

We demonstrate through experiments and numerical simulations that low-density, low-loss, meter-scale plasma channels can be generated by employing a conditioning laser pulse to ionize the neutral gas collar surrounding a hydrodynamic optical-field-ionized (HOFI) plasma channel. We use particle-in-cell simulations to show that the leading edge of the conditioning pulse ionizes the neutral gas collar to generate a deep, low-loss plasma channel which guides the bulk of the conditioning pulse itself as well as any subsequently injected pulses. In proof-of-principle experiments, we generate conditioned HOFI (CHOFI) waveguides with axial electron densities of n_{e0}≈1×10^{17}cm^{-3} and a matched spot size of 26μm. The power attenuation length of these CHOFI channels was calculated to be L_{att}=(21±3)m, more than two orders of magnitude longer than achieved by HOFI channels. Hydrodynamic and particle-in-cell simulations demonstrate that meter-scale CHOFI waveguides with attenuation lengths exceeding 1 m could be generated with a total laser pulse energy of only 1.2 J per meter of channel. The properties of CHOFI channels are ideally suited to many applications in high-intensity light-matter interactions, including multi-GeV plasma accelerator stages operating at high pulse repetition rates.

Automation and control of laser wakefield accelerators using Bayesian optimization

Laser wakefield accelerators promise to revolutionize many areas of accelerator science. However, one of the greatest challenges to their widespread adoption is the difficulty in control and optimization of the accelerator outputs due to coupling between input parameters and the dynamic evolution of the accelerating structure. Here, we use machine learning techniques to automate a 100 MeV-scale accelerator, which optimized its outputs by simultaneously varying up to six parameters including the spectral and spatial phase of the laser and the plasma density and length. Most notably, the model built by the algorithm enabled optimization of the laser evolution that might otherwise have been missed in single-variable scans. Subtle tuning of the laser pulse shape caused an 80% increase in electron beam charge, despite the pulse length changing by just 1%.

The Virtual Electrode Recording Tool for EXtracellular Potentials (VERTEX) Version 2.0: Modelling in vitro electrical stimulation of brain tissue

Neuronal circuits can be modelled in detail allowing us to predict the effects of stimulation on individual neurons. Electrical stimulation of neuronal circuits in vitro and in vivo excites a range of neurons within the tissue and measurements of neural activity, e.g the local field potential (LFP), are again an aggregate of a large pool of cells. The previous version of our Virtual Electrode Recording Tool for EXtracellular Potentials (VERTEX) allowed for the simulation of the LFP generated by a patch of brain tissue. Here, we extend VERTEX to simulate the effect of electrical stimulation through a focal electric field. We observe both direct changes in neural activity and changes in synaptic plasticity. Testing our software in a model of a rat neocortical slice, we determine the currents contributing to the LFP, the effects of paired pulse stimulation to induce short term plasticity (STP), and the effect of theta burst stimulation (TBS) to induce long term potentiation (LTP).

Beliefs about Binge Eating: Psychometric Properties of the Eating Beliefs Questionnaire (EBQ-18) in Eating Disorder, Obese, and Community Samples

Binge eating is a core diagnostic feature of bulimia nervosa, binge eating disorder, anorexia nervosa binge/purge type, and is a common feature of "other specified" and "unspecified" feeding and eating disorders. It has been suggested that specific metacognitive beliefs about food, eating, and binge eating may play a key role in the maintenance of binge eating behaviour. The Eating Beliefs Questionnaire (EBQ-18) provides a brief self-report assessment tool measuring three types of metacognitive beliefs: negative, positive, and permissive beliefs about food and eating. This study aimed to build on past research by validating the factor structure and psychometric properties of the EBQ-18 using both a clinical and non-clinical sample. A sample of 688 participants (n = 498 non-clinical participants, n = 161 participants seeking treatment for an eating disorder, and n = 29 participants seeking treatment for obesity) completed a battery of questionnaires, including the EBQ-18 and other measures of eating disorder symptoms and relevant constructs. A subset of 100 non-clinical participants completed the test battery again after an interval of two-weeks, and 38 clinical participants completed the EBQ-18 before and after receiving psychological treatment for their eating disorder. A confirmatory factor analysis (CFA) was conducted and psychometric properties of this measure were assessed. The results of this study provide support for the three-factor model of the EBQ-18. In addition, the EBQ-18 was found to be a valid and reliable measure, with excellent internal consistency, good test-retest reliability in the non-clinical sample, and also demonstrated evidence of sensitivity to treatment in clinical samples with binge eating pathology. Receiver operating characteristic (ROC) curve analyses were used to identify optimal cut-off scores for the EBQ-18. This study provides valuable information about the utility of the EBQ-18 as a measure for use in both clinical and research settings.

Voxel-wise comparisons of cellular microstructure and diffusion-MRI in mouse hippocampus using 3D Bridging of Optically-clear histology with Neuroimaging Data (3D-BOND)

A key challenge in medical imaging is determining a precise correspondence between image properties and tissue microstructure. This comparison is hindered by disparate scales and resolutions between medical imaging and histology. We present a new technique, 3D Bridging of Optically-clear histology with Neuroimaging Data (3D-BOND), for registering medical images with 3D histology to overcome these limitations. Ex vivo 120 × 120 × 200 μm resolution diffusion-MRI (dMRI) data was acquired at 7 T from adult C57Bl/6 mouse hippocampus. Tissue was then optically cleared using CLARITY and stained with cellular markers and confocal microscopy used to produce high-resolution images of the 3D-tissue microstructure. For each sample, a dense array of hippocampal landmarks was used to drive registration between upsampled dMRI data and the corresponding confocal images. The cell population in each MRI voxel was determined within hippocampal subregions and compared to MRI-derived metrics. 3D-BOND provided robust voxel-wise, cellular correlates of dMRI data. CA1 pyramidal and dentate gyrus granular layers had significantly different mean diffusivity (p > 0.001), which was related to microstructural features. Overall, mean and radial diffusivity correlated with cell and axon density and fractional anisotropy with astrocyte density, while apparent fibre density correlated negatively with axon density. Astrocytes, axons and blood vessels correlated to tensor orientation.

New pathogen-specific immunoPET/MR tracer for molecular imaging of a systemic bacterial infection

The specific and rapid detection of Enterobacteriaceae, the most frequent cause of gram-negative bacterial infections in humans, remains a major challenge. We developed a non-invasive method to rapidly detect systemic Yersinia enterocolitica infections using immunoPET (antibody-targeted positron emission tomography) with [64Cu]NODAGA-labeled Yersinia-specific polyclonal antibodies targeting the outer membrane protein YadA. In contrast to the tracer [18F]FDG, [64Cu]NODAGA-YadA uptake co-localized in a dose dependent manner with bacterial lesions of Yersinia-infected mice, as detected by magnetic resonance (MR) imaging. This was accompanied by elevated uptake of [64Cu]NODAGA-YadA in infected tissues, in ex vivo biodistribution studies, whereas reduced uptake was observed following blocking with unlabeled anti-YadA antibody. We show, for the first time, a bacteria-specific, antibody-based, in vivo imaging method for the diagnosis of a Gram-negative enterobacterial infection as a proof of concept, which may provide new insights into pathogen-host interactions.

Clinical evaluation of the newly formatted lateral-flow device for invasive pulmonary aspergillosis

The study evaluated the newly formatted Aspergillus-specific lateral-flow-device (LFD), and compared its performance to the original prototype "old" LFD test using BALF samples from 28 patients (14 patients with probable/proven invasive pulmonary aspergillosis [IPA] and 14 patients with no evidence for IPA). A total of 10/14 (71%) of BALF samples from patients with probable/proven IPA resulted positive with the new LFD, including 8/9 with true-positive and 2/5 with false-negative results with the old LFD. All 14 samples from patients without IPA resulted negative with the new LFD; specificity of the new LFD was significantly improved compared to the old LFD.

Excitation and Control of Plasma Wakefields by Multiple Laser Pulses

We demonstrate experimentally the resonant excitation of plasma waves by trains of laser pulses. We also take an important first step to achieving an energy recovery plasma accelerator by showing that a plasma wave can be damped by an out-of-resonance trailing laser pulse. The measured laser wakefields are found to be in excellent agreement with analytical and numerical models of wakefield excitation in the linear regime. Our results indicate a promising direction for achieving highly controlled, GeV-scale laser-plasma accelerators operating at multikilohertz repetition rates.

A compact, low cost Marx bank for generating capillary discharge plasmas

We describe in detail a low power Compact Marx Bank (CMB) circuit that can provide 20 kV, 500 A pulses of approximately 100-200 ns duration. One application is the generation of capillary discharge plasmas of density ≈10¹⁸ cm^-3 used in laser plasma accelerators. The CMB is triggered with a high speed solid state switch and gives a high voltage output pulse with a ns scale rise time into a 50 Ω load (coaxial cable) with <4 ns voltage jitter. Its small size (10 cm  ×  25 cm  ×  5 cm) means that it can be placed right next to the capillary discharge in the target chamber to avoid the need to impedance match. The electrical energy required per discharge is <1 J, and the CMB can be run at shot repetition rates of ≳1 Hz. This low power requirement means that the circuit can easily be powered by a small lead acid battery and, therefore, can be floated relative to laboratory earth. The CMB is readily scalable and pulses >45 kV are demonstrated in air discharges.

A Pilot Study Comparing the Use of Below-Knee and Above-Knee Graduated Stockings in Patients with Superficial Venous Incompetence

Objective:

Investigation of the effects of high- and low-ankle-pressure, above- and below-knee compression stockings on the haemodynamics of normal and superficially incompetent venous systems.

Design:

Prospective duplex study of a normal group and a venous incompetence group randomised to high- or low-pressure stockings.

Setting:

Vascular services of a University Hospital.

Subjects:

Six subjects with normal venous haemodynamics (12 limbs) and 12 patients with superficial venous incompetence (20 limbs).

Methods:

Subjects wore below-knee and then above-knee stockings for 1 week each. Duplex scans were performed at the outset and end of the study and on fitting and after wearing each stocking type.

Main outcome measures:

Duplex-derived femoral and popliteal venous velocities were measured and indexed against the initial velocity.

Results:

Below-knee stockings produced only minor changes. Above-knee stockings produced increased velocities in normal subjects. Similar changes were only seen with higher-pressure stockings in patients with incompetence.

Conclusion:

Above-knee, high-ankle-pressure stockings produce increased deep venous flow velocities.

Cell wall modifications during conidial maturation of the human pathogenic fungus Pseudallescheria boydii

Progress in extending the life expectancy of cystic fibrosis (CF) patients remains jeopardized by the increasing incidence of fungal respiratory infections. Pseudallescheria boydii (P. boydii), an emerging pathogen of humans, is a filamentous fungus frequently isolated from the respiratory secretions of CF patients. It is commonly believed that infection by this fungus occurs through inhalation of airborne conidia, but the mechanisms allowing the adherence of Pseudallescheria to the host epithelial cells and its escape from the host immune defenses remain largely unknown. Given that the cell wall orchestrates all these processes, we were interested in studying its dynamic changes in conidia as function of the age of cultures. We found that the surface hydrophobicity and electronegative charge of conidia increased with the age of culture. Melanin that can influence the cell surface properties, was extracted from conidia and estimated using UV-visible spectrophotometry. Cells were also directly examined and compared using electron paramagnetic resonance (EPR) that determines the production of free radicals. Consistent with the increased amount of melanin, the EPR signal intensity decreased suggesting polymerization of melanin. These results were confirmed by flow cytometry after studying the effect of melanin polymerization on the surface accessibility of mannose-containing glycoconjugates to fluorescent concanavalin A. In the absence of melanin, conidia showed a marked increase in fluorescence intensity as the age of culture increased. Using atomic force microscopy, we were unable to find rodlet-forming hydrophobins, molecules that can also affect conidial surface properties. In conclusion, the changes in surface properties and biochemical composition of the conidial wall with the age of culture highlight the process of conidial maturation. Mannose-containing glycoconjugates that are involved in immune recognition, are progressively masked by polymerization of melanin, an antioxidant that is commonly thought to allow fungal escape from the host immune defenses.

Effects on specific promoter DNA methylation in zebrafish embryos and larvae following benzo[a]pyrene exposure

Benzo[a]pyrene (BaP) is an established carcinogen and reproductive and developmental toxicant. BaP exposure in humans and animals has been linked to infertility and multigenerational health consequences. DNA methylation is the most studied epigenetic mechanism that regulates gene expression, and mapping of methylation patterns has become an important tool for understanding pathologic gene expression events. The goal of this study was to investigate aberrant changes in promoter DNA methylation in zebrafish embryos and larvae following a parental and continued embryonic waterborne BaP exposure. A total of 21 genes known for their role in human diseases were selected to measure percent methylation by multiplex deep sequencing. At 96hpf (hours post fertilization) compared to 3.3hpf, dazl, nqo1, sox3, cyp1b1, and gstp1 had higher methylation percentages while c-fos and cdkn1a had decreased CG methylation. BaP exposure significantly reduced egg production and offspring survival. Moreover, BaP decreased global methylation and altered CG, CHH, and CHG methylation both at 3.3 and 96hpf. CG methylation changed by 10% or more due to BaP in six genes (c-fos, cdkn1a, dazl, nqo1, nrf2, and sox3) at 3.3hpf and in ten genes (c-fos, cyp1b1, dazl, gstp1, mlh1, nqo1, pten, p53, sox2, and sox3) at 96hpf. BaP also induced gene expression of cyp1b1 and gstp1 at 96hpf which were found to be hypermethylated. Further studies are needed to link aberrant CG, CHH, and CHG methylation to heritable epigenetic consequences associated with disease in later life.

Toll-like receptor 3 expression in glia and neurons alters in response to white matter injury in preterm infants

Toll-like receptors (TLRs) are members of the pattern recognition receptor family that detect components of foreign pathogens or endogenous molecules released in response to injury. Recent studies demonstrate that TLRs also have a functional role in regulating neuronal proliferation in the developing brain. This study investigated cellular expression of TLR3 using immunohistochemistry on human brain tissue. The tissue sections analysed contained anterior and lateral periventricular white matter from the frontal and parietal lobes in post-mortem neonatal cases with a postmenstrual age range of 23.6-31.4 weeks. In addition to preterm brains without overt pathology (control), preterm pathology cases with evidence of white matter injuries (WMI) were also examined. In order to identify TLR-positive cells, we utilized standard double-labelling immunofluorescence co-labelling techniques and confocal microscopy to compare co-expression of TLR3 with a neuronal marker (NeuN) or with glial markers (GFAP for astrocytes, Iba-1 for microglia and Olig2 for oligodendrocytes). We observed an increase in the neuronal (28 vs. 17%) and astroglial (38 vs. 21%) populations in the WMI group compared to controls in the anterior regions of the periventricular white matter in the frontal lobe. The increase in neurons and astrocytes in the WMI cases was associated with an increase in TLR3 immunoreactivity. This expression was significantly increased in the astroglia. The morphology of the TLR3 signal in the control cases was globular and restricted to the perinuclear region of the neurons and astrocytes, whilst in the cases of WMI, both neuronal, axonal and astroglial TLR3 expression was more diffuse (i.e., a different intracellular distribution) and could be detected along the extensions of the processes. This study demonstrates for the first time that neurons and glial cells in human neonatal periventricular white matter express TLR3 during development. The patterns of TLR3 expression were altered in the presence of WMI, which might influence normal developmental processes within the immature brain. Identifying changes in TLR3 expression during fetal development may be key to understanding the reduced volumes of grey matter and impaired cortical development seen in preterm infants.

Characteristics of Epstein-Barr virus hepatitis among patients with jaundice or acute hepatitis

BACKGROUND

Abnormal liver blood tests are common in Epstein-Barr virus (EBV) infection, but symptomatic hepatitis is rare. The demographics, clinical features and outcome of EBV hepatitis are incompletely understood, particularly in the elderly people.

AIM

To identify the demographics, presenting features and natural history of EBV hepatitis.

METHODS

Retrospective review of 1995 consecutive patients attending the jaundice hotline clinic over a 13-year period. Data collected included demographic information, presenting features, clinical and laboratory parameters, radiology imaging and clinical outcome.

RESULTS

Seventeen of 1995 (0.85%) had EBV hepatitis. The median age was 40 years (range 18-68 years). Ten of 17 (59%) patients were aged >30 years, and seven of 17 (41%) patients were aged ≥60 years. Fifteen of 17 (88%) patients presented with clinical/biochemical evidence of jaundice. Seventeen of 17 (100%) patients had a serum lymphocytosis at presentation. 2/17 (12%) patients with EBV hepatitis presented with the classical features of infectious mononucleosis (fever, sore throat and lymphadenopathy). Splenomegaly was present in 15/17 (88%) of patients. Symptoms lasted for a median 8 weeks (range 1-12 weeks). Three of 17 (18%) patients required a brief hospital admission.

CONCLUSIONS

In patients presenting with jaundice/hepatitis, EBV hepatitis is an uncommon diagnosis and causes a self-limiting hepatitis. The diagnosis is suggested by the presence of a lymphocytosis and/or splenomegaly. The majority of patients do not have infectious mononucleosis. Compared with infectious mononucleosis, EBV hepatitis affects an older age group, with nearly half of patients being aged more than 60 years. The diagnosis should be considered in all patients with unexplained hepatitis irrespective of their age.

PP154. Relationship between recorded and reported snoring during pregnancy: Objective measurement versus questionnaire responses

INTRODUCTION

Snoring is a common symptom of sleep disordered breathing (SDB), a condition that is present in 4% of the general population. SDB is identified by snoring and repetitive cessation of breathing during sleep accompanied by repetitive hypoxia and has been found to be associated with hypertension, stroke and heart attack. There is not depth of knowledge examining the association between SDB and pregnancy outcomes.

OBJECTIVES

To examine the prevalence of self reported snoring in pregnancy and the potential association between self reported snoring and the development of Hypertensive Disorders of Pregnancy (HDP) within a larger cohort from a prevalence of SDB in pregnancy study.

METHODS

Questionnaires were administered to pregnant women attending an outpatient's antenatal clinic. The self reported snoring is a component of the Epworth scale. Pregnancy progression and outcome data were collected on all participants and analyse by IBM SPSS v.20™ utilising Chi-square analysis, Student T test and logistic regression analysis. HDP diagnoses were in alignment with the SOMANZ (2009) diagnostic criteria.

RESULTS

Questionnaires were administered and outcomes collected on 2023 pregnancies. Snoring was reported by 49.2% of women. HDP affected 10.1% of the cohort, 3.3% of whom were preeclamptic. Of the pregnancies affected by HDP self reported snoring occurred in 57.7% in comparison to 43.3% who do not report snoring (p<0.001).

CONCLUSION

This would indicate that there is an association between self reported snoring and the development of HDP. Further analysis will be undertaken to model the effect of other potential risk factors such as maternal age, parity, pre-pregnancy BMI and other co morbidities.

Free-energy minimization and the dark-room problem

Recent years have seen the emergence of an important new fundamental theory of brain function. This theory brings information-theoretic, Bayesian, neuroscientific, and machine learning approaches into a single framework whose overarching principle is the minimization of surprise (or, equivalently, the maximization of expectation). The most comprehensive such treatment is the “free-energy minimization” formulation due to Karl Friston (see e.g., Friston and Stephan, 2007; Friston, 2010a,b – see also Fiorillo, 2010; Thornton, 2010). A recurrent puzzle raised by critics of these models is that biological systems do not seem to avoid surprises. We do not simply seek a dark, unchanging chamber, and stay there. This is the “Dark-Room Problem.” Here, we describe the problem and further unpack the issues to which it speaks. Using the same format as the prolog of Eddington’s Space, Time, and Gravitation (Eddington, 1920) we present our discussion as a conversation between: an information theorist (Thornton), a physicist (Friston), and a philosopher (Clark).

Detection of invasive pulmonary aspergillosis in haematological malignancy patients by using lateral-flow technology

Invasive pulmonary aspergillosis (IPA) is a leading cause of morbidity and mortality in haematological malignancy patients and hematopoietic stem cell transplant recipients¹. Detection of IPA represents a formidable diagnostic challenge and, in the absence of a 'gold standard', relies on a combination of clinical data and microbiology and histopathology where feasible. Diagnosis of IPA must conform to the European Organization for Research and Treatment of Cancer and the National Institute of Allergy and Infectious Diseases Mycology Study Group (EORTC/MSG) consensus defining "proven", "probable", and "possible" invasive fungal diseases². Currently, no nucleic acid-based tests have been externally validated for IPA detection and so polymerase chain reaction (PCR) is not included in current EORTC/MSG diagnostic criteria.

Identification of Aspergillus in histological sections is problematic because of similarities in hyphal morphologies with other invasive fungal pathogens³, and proven identification requires isolation of the etiologic agent in pure culture. Culture-based approaches rely on the availability of biopsy samples, but these are not always accessible in sick patients, and do not always yield viable propagules for culture when obtained.

An important feature in the pathogenesis of Aspergillus is angio-invasion, a trait that provides opportunities to track the fungus immunologically using tests that detect characteristic antigenic signatures molecules in serum and bronchoalveolar lavage (BAL) fluids. This has led to the development of the Platelia enzyme immunoassay (GM-EIA) that detects Aspergillus galactomannan and a 'pan-fungal' assay (Fungitell test) that detects the conserved fungal cell wall component (1 →3)-β-D-glucan, but not in the mucorales that lack this component in their cell walls^1,4. Issues surrounding the accuracy of these tests^1,4-6 has led to the recent development of next-generation monoclonal antibody (MAb)-based assays that detect surrogate markers of infection^1,5.

Thornton⁵ recently described the generation of an Aspergillus-specific MAb (JF5) using hybridoma technology and its use to develop an immuno-chromatographic lateral-flow device (LFD) for the point-of-care (POC) diagnosis of IPA. A major advantage of the LFD is its ability to detect activity since MAb JF5 binds to an extracellular glycoprotein antigen that is secreted during active growth of the fungus only⁵. This is an important consideration when using fluids such as lung BAL for diagnosing IPA since Aspergillus spores are a common component of inhaled air. The utility of the device in diagnosing IPA has been demonstrated using an animal model of infection, where the LFD displayed improved sensitivity and specificity compared to the Platelia GM and Fungitell (1 → 3)-β-D-glucan assays⁷.

Here, we present a simple LFD procedure to detect Aspergillus antigen in human serum and BAL fluids. Its speed and accuracy provides a novel adjunct point-of-care test for diagnosis of IPA in haematological malignancy patients.