Longitudinal pathways between childhood BMI, body dissatisfaction, and adolescent depression: an observational study using the UK Millenium Cohort Study.

BACKGROUND: Globally, more adolescents are having depressive symptoms than in the past. High BMI is a risk factor for depressive symptoms, potentially acting via increased body dissatisfaction. Robust longitudinal evidence of these associations could help to inform preventive interventions, but such evidence remains scarce. We investigated the longitudinal associations between BMI at age 7 years and depressive symptoms at age 14 years (objective 1), BMI at age 7 years and body dissatisfaction at age 11 years (objective 2), and body dissatisfaction at age 11 years and depression at age 14 years (objective 3). We also investigated the extent to which body dissatisfaction mediated the association between BMI and depressive symptoms (objective 4). METHODS: This study used data from the Millennium Cohort Study, a representative longitudinal general population cohort of UK children born between Sept 1, 2000, and Jan 11, 2002. We used univariable and multivariable linear regression models to investigate the associations in objectives 1-3 adjusting for a range of child-level and family-level confounders. For mediation analyses we used non-parametric g-formula (objective 4). We reported stratified results in presence of sex differences. All analyses were based on participants with complete BMI data and imputed confounders and outcomes. FINDINGS: Our sample included 13 135 participants. Of these, 6624 (50·4%) were male participants and 6511 (49·6%) were female participants; 11 096 (84·4%) were of White ethnicity and 2039 (15·6%) were from a minority ethnic background. At baseline, mean age was 7·2 years (SD 0·25, range 6·3-8·3). In multivariable models, an SD increase in BMI at age 7 years was associated with greater depressive symptoms at age 14 years (estimated regression coefficient [coeff]: 0·30, 95% CI 0·17-0·43) and greater body dissatisfaction at age 11 years (coeff 0·15, 0·12-0·18). Greater body dissatisfaction at age 11 years was associated with higher depressive symptoms at age 14 years (coeff 0·60, 0·52-0·68). All these associations were twice as large in girls as in boys. Body dissatisfaction explained 43% of the association between BMI and depression in girls. INTERPRETATION: Our findings bear relevance for interventions aimed at reducing weight in childhood and reducing body dissatisfaction. Implementation of evidence-based body image interventions and identification of drivers of weight stigma should be key public health priorities. Interventions aiming to reduce weight in childhood need to avoid increasing body dissatisfaction and should target environmental drivers of weight rather than individuals. FUNDING: Wellcome Trust; The Royal Society; Economic and Social Research Council; and the National Institute for Health and Care Research.

The experience of Anxiety for people with Parkinson's disease.

Anxiety is a common non-motor symptom of Parkinson's disease (PD) associated with increased disability and reduced quality of life. However, anxiety is poorly understood, underdiagnosed, and undertreated. To date, little research has explored how anxiety is experienced by patients themselves. This study explored the experience of anxiety for people with Parkinson's (PWP) to inform future research and interventions. Semi-structured interviews with 22 PWP (aged 43-80, 50% female) were conducted and analysed using inductive thematic analysis. Four main themes were extracted: conceptualising anxiety; anxiety and the body; anxiety and social identity; and coping with anxiety. Sub-themes revealed inconsistent perceptions: anxiety was in body and mind, part of disease and human nature, part of self-identity and a threat to it. The symptoms described were diverse. Many perceived their anxiety as more incapacitating than motor symptoms or capable of amplifying them, and described that anxiety restricted their lifestyle. All perceived anxiety as connected to PD, and ultimately persistent: dominant aspirations were coping and acceptance rather than cures, with medications strongly resisted. Findings highlight the complexity and high importance of anxiety for PWP. Implications for therapeutic approaches are discussed.

Antifungal Effect of Brassica Tissues on the Mycotoxigenic Cereal Pathogen Fusarium graminearum.

Fusarium graminearum is a globally important cereal pathogen, causing head blight in wheat, resulting in yield losses and mycotoxin contamination. Currently, triazole fungicides are used to suppress Fusarium graminearum, however, the declining effectiveness of triazoles and concerns over the safety of pesticides have led to the pursuit of safe alternative crop protection strategies such as biofumigation. In the present study, species belonging to Brassicaceae (Brassica juncea, Raphanus sativus, Eruca sativa) were assessed for their biofumigation potential against F. graminearum and the glucosinolate profile of the brassicas was determined. In Petri dishes, mycelial plugs of Fusarium graminearum were exposed to frozen/defrosted leaf discs of brassicas collected at early-leaf, stem-extension, and early-bud stages. Additionally, F. graminearum inoculum was incubated in soil amended with chopped tissues of brassicas in a closed jar experiment. Glucosinolate analysis of the leaf tissue of brassicas revealed that the total glucosinolate concentration of B. juncea 'Brons' increased with advancing growth stage (24.5-51.9 µmol g-1). Brassica juncea leaf discs were effective against mycelial growth, while the sinigrin content in the leaf tissue corresponded to the level of suppression. At the stem-extension and early-bud stages, B. juncea 'Brons' showed 87-90% suppression with four leaf discs, and 100% suppression with eight leaf discs. Brassica juncea 'Caliente Rojo' leaf discs collected at the stem-extension stage showed 94% inhibition with eight discs. In the closed jar experiment, each brassica species significantly suppressed F. graminearum inoculum by 41-55%. The findings suggest that the brassica species investigated in the present study could be effective in reducing the inoculum of F. graminearum in soil prior to cereal production.

Determination of Zeta Potential via Nanoparticle Translocation Velocities through a Tunable Nanopore: Using DNA-modified Particles as an Example.

Nanopore technologies, known collectively as Resistive Pulse Sensors (RPS), are being used to detect, quantify and characterize proteins, molecules and nanoparticles. Tunable resistive pulse sensing (TRPS) is a relatively recent adaptation to RPS that incorporates a tunable pore that can be altered in real time. Here, we use TRPS to monitor the translocation times of DNA-modified nanoparticles as they traverse the tunable pore membrane as a function of DNA concentration and structure (i.e., single-stranded to double-stranded DNA). TRPS is based on two Ag/AgCl electrodes, separated by an elastomeric pore membrane that establishes a stable ionic current upon an applied electric field. Unlike various optical-based particle characterization technologies, TRPS can characterize individual particles amongst a sample population, allowing for multimodal samples to be analyzed with ease. Here, we demonstrate zeta potential measurements via particle translocation velocities of known standards and apply these to sample analyte translocation times, thus resulting in measuring the zeta potential of those analytes. As well as acquiring mean zeta potential values, the samples are all measured using a particle-by-particle perspective exhibiting more information on a given sample through sample population distributions, for example. Of such, this method demonstrates potential within sensing applications for both medical and environmental fields.

Protein detection using tunable pores: resistive pulses and current rectification.

We present the first comparison between assays that use resistive pulses or rectification ratios on a tunable pore platform. We compare their ability to quantify the cancer biomarker Vascular Endothelial Growth Factor (VEGF). The first assay measures the electrophoretic mobility of aptamer modified nanoparticles as they traverse the pore. By controlling the aptamer loading on the particle surface, and measuring the speed of each translocation event we are able to observe a change in velocity as low as 18 pM. A second non-particle assay exploits the current rectification properties of conical pores. We report the first use of Layer-by-Layer (LbL) assembly of polyelectrolytes onto the surface of the polyurethane pore. The current rectification ratios demonstrate the presence of the polymers, producing pH and ionic strength-dependent currents. The LbL assembly allows the facile immobilisation of DNA aptamers onto the pore allowing a specific dose response to VEGF. Monitoring changes to the current rectification allows for a rapid detection of 5 pM VEGF. Each assay format offers advantages in their setup and ease of preparation but comparable sensitivities.

Characterisation of the protein corona using tunable resistive pulse sensing: determining the change and distribution of a particle's surface charge.

The zeta potential of the protein corona around carboxyl particles has been measured using tunable resistive pulse sensing (TRPS). A simple and rapid assay for characterising zeta potentials within buffer, serum and plasma is presented monitoring the change, magnitude and distribution of proteins on the particle surface. First, we measure the change in zeta potential of carboxyl-functionalised nanoparticles in solutions that contain biologically relevant concentrations of individual proteins, typically constituted in plasma and serum, and observe a significant difference in distributions and zeta values between room temperature and 37 °C assays. The effect is protein dependent, and the largest difference between the two temperatures is recorded for the γ-globulin protein where the mean zeta potential changes from -16.7 to -9.0 mV for 25 and 37 °C, respectively. This method is further applied to monitor particles placed into serum and/or plasma. A temperature-dependent change is again observed with serum showing a 4.9 mV difference in zeta potential between samples incubated at 25 and 37 °C; this shift was larger than that observed for samples in plasma (0.4 mV). Finally, we monitor the kinetics of the corona reorientation for particles initially placed into serum and then adding 5 % (V/V) plasma. The technology presented offers an interesting insight into protein corona structure and kinetics of formation measured in biologically relevant solutions, i.e. high protein, high salt levels, and its particle-by-particle analysis gives a measure of the distribution of particle zeta potential that may offer a better understanding of the behaviour of nanoparticles in solution. Graphical Abstract The relative velocity of a nanoparticle as it traverses a nanopore can be used to determine its zeta potential. Monitoring the changes in translocation speeds can therefore be used to follow changes to the surface chemistry/composition of 210 nm particles that were placed into protein rich solutions, serum and plasma. The particle-by-particle measurements allow the zeta potential and distribution of the particles to be characterised, illustrating the effects of protein concentration and temperature on the protein corona. When placed into a solution containing a mixture of proteins, the affinity of the protein to the particle's surface determines the corona structure, and is not dependent on the protein concentration.

Particle-by-Particle Charge Analysis of DNA-Modified Nanoparticles Using Tunable Resistive Pulse Sensing.

Resistive pulse sensors, RPS, are allowing the transport mechanism of molecules, proteins and even nanoparticles to be characterized as they traverse pores. Previous work using RPS has shown that the size, concentration and zeta potential of the analyte can be measured. Here we use tunable resistive pulse sensing (TRPS) which utilizes a tunable pore to monitor the translocation times of nanoparticles with DNA modified surfaces. We start by demonstrating that the translocation times of particles can be used to infer the zeta potential of known standards and then apply the method to measure the change in zeta potential of DNA modified particles. By measuring the translocation times of DNA modified nanoparticles as a function of packing density, length, structure, and hybridization time, we observe a clear difference in zeta potential using both mean values and population distributions as a function of the DNA structure. We demonstrate the ability to resolve the signals for ssDNA, dsDNA, small changes in base length for nucleotides between 15 and 40 bases long, and even the discrimination between partial and fully complementary target sequences. Such a method has potential and applications in sensors for the monitoring of nanoparticles in both medical and environmental samples.

The effect of two preparation procedures on an equine arena surface in relation to motion of the hoof and metacarpophalangeal joint.

A link between surface characteristics and injury has been identified in equine disciplines. Maintenance procedures are reported to affect surface characteristics and could influence horse movement. The study investigated limb and hoof movement on a synthetic surface following two different preparations (harrowing and rolling). Nine horses were recorded using infrared cameras and retro-reflective markers at walk, trot and canter on two surface preparations in a cross-over design. Hoof rotation and displacement, metacarpophalangeal joint (MCPJ) extension and third metacarpal (McIII) inclination (roll, pitch and yaw) were analysed using a general linear model. Surface hardness and traction were also measured. No differences in hoof rotations or hoof displacements were found between preparations. However, following harrowing, greater (P<0.05) MCPJ extension at mid-stance and greater (P<0.05) McIII adduction at impact was found when gait was grouped. Hardness and traction were statistically similar for both preparations. Alteration to the surface cushion appears to be sufficient to produce subtle changes in stride characteristics.