On-Tissue Chemical Derivatization in Mass Spectrometry Imaging

Mass spectrometry imaging (MSI) combines molecular and spatial information in a valuable tool for a wide range of applications. Matrix‐assisted laser desorption/ionization (MALDI) is at the forefront of MSI ionization due to its wide availability and increasing improvement in spatial resolution and analysis speed. However, ionization suppression, low concentrations, and endogenous and methodological interferences cause visualization problems for certain molecules. Chemical derivatization (CD) has proven a viable solution to these issues when applied in mass spectrometry platforms. Chemical tagging of target analytes with larger, precharged moieties aids ionization efficiency and removes analytes from areas of potential isobaric interferences. Here, we address the application of CD on tissue samples for MSI analysis, termed on‐tissue chemical derivatization (OTCD). MALDI MSI will remain the focus platform due to its popularity, however, alternative ionization techniques such as liquid extraction surface analysis and desorption electrospray ionization will also be recognized. OTCD reagent selection, application, and optimization methods will be discussed in detail. MSI with OTCD is a powerful tool to study the spatial distribution of poorly ionizable molecules within tissues. Most importantly, the use of OTCD−MSI facilitates the analysis of previously inaccessible biologically relevant molecules through the adaptation of existing CD methods. Though further experimental optimization steps are necessary, the benefits of this technique are extensive

Spectral function of the Kondo model in high magnetic fields

Using a recently developed perturbative renormalization group (RG) scheme, we calculate analytically the spectral function of a Kondo impurity for either large frequencies w or large magnetic field B and arbitrary frequencies. For large w >> max[B,T_K] the spectral function decays as 1/ln^2[ w/T_K ] with prefactors which depend on the magnetization. The spin-resolved spectral function displays a pronounced peak at w=B with a characteristic asymmetry. In a detailed comparison with results from numerical renormalization group (NRG) and bare perturbation theory in next-to-leading logarithmic order, we show that our perturbative RG scheme is controlled by the small parameter 1/ln[ max(w,B)/T_K]. Furthermore, we assess the ability of the NRG to resolve structures at finite frequencies.Comment: 8 pages, version published in PRB, minor change

Arm-in-cage testing of natural human-derived mosquito repellents

BACKGROUND: Individual human subjects are differentially attractive to mosquitoes and other biting insects. Previous investigations have demonstrated that this can be attributed partly to enhanced production of natural repellent chemicals by those individuals that attract few mosquitoes in the laboratory. The most important compounds in this respect include three aldehydes, octanal, nonanal and decanal, and two ketones, 6-methyl-5-hepten-2-one and geranylacetone [(E)-6,10-dimethylundeca-5,9-dien-2-one]. In olfactometer trials, these compounds interfered with attraction of mosquitoes to a host and consequently show promise as novel mosquito repellents. METHODS: To test whether these chemicals could provide protection against mosquitoes, laboratory repellency trials were carried out to test the chemicals individually at different concentrations and in different mixtures and ratios with three major disease vectors: Anopheles gambiae, Culex quinquefasciatus and Aedes aegypti. RESULTS: Up to 100% repellency was achieved depending on the type of repellent compound tested, the concentration and the relative composition of the mixture. The greatest effect was observed by mixing together two compounds, 6-methyl-5-hepten-2-one and geranylacetone in a 1:1 ratio. This mixture exceeded the repellency of DEET when presented at low concentrations. The repellent effect of this mixture was maintained over several hours. Altering the ratio of these compounds significantly affected the behavioural response of the mosquitoes, providing evidence for the ability of mosquitoes to detect and respond to specific mixtures and ratios of natural repellent compounds that are associated with host location. CONCLUSION: The optimum mixture of 6-methyl-5-hepten-2-one and geranylacetone was a 1:1 ratio and this provided the most effective protection against all species of mosquito tested. With further improvements in formulation, selected blends of these compounds have the potential to be exploited and developed as human-derived novel repellents for personal protection

Epidemiological, clinical and genetic aspects of adult onset isolated focal dystonia in Ireland

Background: Adult onset idiopathic isolated focal dystonia presents with a number of phenotypes. Reported prevalence rates vary considerably; well-characterized cohorts are important to our understanding of this disorder. Aim: To perform a nationwide epidemiological study of adult onset idiopathic isolated focal dystonia in the Republic of Ireland. Methods: Patients with adult onset idiopathic isolated focal dystonia were recruited from multiple sources. Diagnosis was based on assessment by a neurologist with an expertise in movement disorders. When consent was obtained, a number of clinical features including family history were assessed. Results: On the prevalence date there were 592 individuals in Ireland with adult onset idiopathic isolated focal dystonia, a point prevalence of 17.8 per 100 000 (95% confidence interval 16.4-19.2). Phenotype numbers were cervical dystonia 410 (69.2%), blepharospasm 102 (17.2%), focal hand dystonia 39 (6.6%), spasmodic dysphonia 18 (3.0%), musician\u27s dystonia 17 (2.9%) and oromandibular dystonia six (1.0%). Sixty-two (16.5%) of 375 consenting index cases had a relative with clinically confirmed adult onset idiopathic isolated focal dystonia (18 multiplex and 24 duplex families). Marked variations in the proportions of patients with tremor, segmental spread, sensory tricks, pain and psychiatric symptoms by phenotype were documented. Conclusions: The prevalence of adult onset idiopathic isolated focal dystonia in Ireland is higher than that recorded in many similar service-based epidemiological studies but is still likely to be an underestimate. The low proportion of individuals with blepharospasm may reflect reduced environmental exposure to sunlight in Ireland. This study will serve as a resource for international comparative studies of environmental and genetic factors in the pathogenesis of the disorder

A randomised controlled trial of an exercise intervention promoting activity, independence and stability in older adults with mild cognitive impairment and early dementia (PrAISED) – A Protocol

© 2019 The Author(s). Background: People with dementia progressively lose cognitive and functional abilities. Interventions promoting exercise and activity may slow decline. We developed a novel intervention to promote activity and independence and prevent falls in people with mild cognitive impairment (MCI) or early dementia. We successfully undertook a feasibility randomised controlled trial (RCT) to refine the intervention and research delivery. We are now delivering a multi-centred RCT to evaluate its clinical and cost-effectiveness. Methods: We will recruit 368 people with MCI or early dementia (Montreal Cognitive Assessment score 13-25) and a family member or carer from memory assessment clinics, other community health or social care venues or an online register (the National Institute for Health Research Join Dementia Research). Participants will be randomised to an individually tailored activity and exercise programme delivered using motivational theory to promote adherence and continued engagement, with up to 50 supervised sessions over one year, or a brief falls prevention assessment (control). The intervention will be delivered in participants' homes by trained physiotherapists, occupational therapists and therapy assistants. We will measure disabilities in activities of daily living, physical activity, balance, cognition, mood, quality of life, falls, carer strain and healthcare and social care use. We will use a mixed methods approach to conduct a process evaluation to assess staff training and delivery of the intervention, and to identify individual- and context-level mechanisms affecting intervention engagement and activity maintenance. We will undertake a health economic evaluation to determine if the intervention is cost-effective. Discussion: We describe the protocol for a multi-centre RCT that will evaluate the clinical and cost-effectiveness of a therapy programme designed to promote activity and independence amongst people living with dementia. Trial registration: ISRCTN, ISRCTN15320670. Registered on 4 September 2018

Patient-reported outcome measures for monitoring primary care patients with depression: the PROMDEP cluster RCT and economic evaluation.

BACKGROUND: Guidelines on the management of depression recommend that practitioners use patient-reported outcome measures for the follow-up monitoring of symptoms, but there is a lack of evidence of benefit in terms of patient outcomes. OBJECTIVE: To test using the Patient Health Questionnaire-9 questionnaire as a patient-reported outcome measure for monitoring depression, training practitioners in interpreting scores and giving patients feedback. DESIGN: Parallel-group, cluster-randomised superiority trial; 1 : 1 allocation to intervention and control. SETTING: UK primary care (141 group general practices in England and Wales). INCLUSION CRITERIA: Patients aged ≥ 18 years with a new episode of depressive disorder or symptoms, recruited mainly through medical record searches, plus opportunistically in consultations. EXCLUSIONS: Current depression treatment, dementia, psychosis, substance misuse and risk of suicide. INTERVENTION: Administration of the Patient Health Questionnaire-9 questionnaire with patient feedback soon after diagnosis, and at follow-up 10-35 days later, compared with usual care. PRIMARY OUTCOME: Beck Depression Inventory, 2nd edition, symptom scores at 12 weeks. SECONDARY OUTCOMES: Beck Depression Inventory, 2nd edition, scores at 26 weeks; antidepressant drug treatment and mental health service contacts; social functioning (Work and Social Adjustment Scale) and quality of life (EuroQol 5-Dimension, five-level) at 12 and 26 weeks; service use over 26 weeks to calculate NHS costs; patient satisfaction at 26 weeks (Medical Informant Satisfaction Scale); and adverse events. SAMPLE SIZE: The original target sample of 676 patients recruited was reduced to 554 due to finding a significant correlation between baseline and follow-up values for the primary outcome measure. RANDOMISATION: Remote computerised randomisation with minimisation by recruiting university, small/large practice and urban/rural location. BLINDING: Blinding of participants was impossible given the open cluster design, but self-report outcome measures prevented observer bias. Analysis was blind to allocation. ANALYSIS: Linear mixed models were used, adjusted for baseline depression, baseline anxiety, sociodemographic factors, and clustering including practice as random effect. Quality of life and costs were analysed over 26 weeks. QUALITATIVE INTERVIEWS: Practitioner and patient interviews were conducted to reflect on trial processes and use of the Patient Health Questionnaire-9 using the Normalization Process Theory framework. RESULTS: Three hundred and two patients were recruited in intervention arm practices and 227 patients were recruited in control practices. Primary outcome data were collected for 252 (83.4%) and 195 (85.9%), respectively. No significant difference in Beck Depression Inventory, 2nd edition, score was found at 12 weeks (adjusted mean difference -0.46, 95% confidence interval -2.16 to 1.26). Nor were significant differences found in Beck Depression Inventory, 2nd Edition, score at 26 weeks, social functioning, patient satisfaction or adverse events. EuroQol-5 Dimensions, five-level version, quality-of-life scores favoured the intervention arm at 26 weeks (adjusted mean difference 0.053, 95% confidence interval 0.013 to 0.093). However, quality-adjusted life-years over 26 weeks were not significantly greater (difference 0.0013, 95% confidence interval -0.0157 to 0.0182). Costs were lower in the intervention arm but, again, not significantly (-£163, 95% confidence interval -£349 to £28). Cost-effectiveness and cost-utility analyses, therefore, suggested that the intervention was dominant over usual care, but with considerable uncertainty around the point estimates. Patients valued using the Patient Health Questionnaire-9 to compare scores at baseline and follow-up, whereas practitioner views were more mixed, with some considering it too time-consuming. CONCLUSIONS: We found no evidence of improved depression management or outcome at 12 weeks from using the Patient Health Questionnaire-9, but patients' quality of life was better at 26 weeks, perhaps because feedback of Patient Health Questionnaire-9 scores increased their awareness of improvement in their depression and reduced their anxiety. Further research in primary care should evaluate patient-reported outcome measures including anxiety symptoms, administered remotely, with algorithms delivering clear recommendations for changes in treatment. STUDY REGISTRATION: This study is registered as IRAS250225 and ISRCTN17299295. FUNDING: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 17/42/02) and is published in full in Health Technology Assessment; Vol. 28, No. 17. See the NIHR Funding and Awards website for further award information

Depression follow-up monitoring with the PHQ-9: open cluster-randomised controlled trial.

BACKGROUND: Outcome monitoring of depression is recommended but lacks evidence of patient benefit in primary care. AIM: To test monitoring depression using the PHQ-9 questionnaire with patient feedback. DESIGN AND SETTING: Open cluster-randomised controlled trial in 141 group practices. METHOD: Adults with new depressive episodes were recruited through records searches and opportunistically. EXCLUSION CRITERIA: dementia, psychosis, substance misuse, suicide risk. The PHQ-9 questionnaire was to be administered soon after diagnosis, and 10-35 days later. PRIMARY OUTCOME: Beck Depression Inventory (BDI-II) score at 12 weeks. SECONDARY OUTCOMES: BDI-II at 26 weeks; Work and Social Adjustment Scale and EuroQol EQ-5D-5L quality of life at 12 and 26 weeks; antidepressant treatment, mental health service use, adverse events, and Medical Informant Satisfaction Scale over 26 weeks. RESULTS: 302 intervention arm patients were recruited and 227 controls. At 12 weeks 252 (83.4%) and 195 (85.9%) were followed-up respectively. Only 41% of intervention arm patients had a GP follow-up PHQ-9 recorded. There was no significant difference in BDI-II score at 12 weeks (mean difference -0.46; 95% CI -2.16,1.26), adjusted for baseline depression, baseline anxiety, sociodemographic factors, and clustering by practice). EQ-5D-5L quality of life scores were higher in the intervention arm at 26 weeks (adjusted mean difference 0.053; 95% CI 0.093,0.013). A clinically significant difference in depression at 26 weeks could not be ruled out. No significant differences were found in social functioning, adverse events, or satisfaction. In a per-protocol analysis, antidepressant use and mental health contacts were significantly greater in intervention arm patients with a recorded follow-up PHQ-9. CONCLUSIONS: No evidence was found of improved depression outcome at 12 weeks from monitoring. The findings of possible benefits over 26 weeks warrant replication, investigating possible mechanisms, preferably with automated delivery of monitoring and more instructive feedback

Characteristics associated with risk taking behaviours predict young people's participation in organised activities

Participation in organised activities (OAs) such as sports and special groups can shape adolescent risk taking behaviours. Sensation seeking and inhibitory control play an important role in the emergence of adolescent risk taking behaviours and may explain variations in OA participation as well as inform the development of more effective interventions that use OAs. Data from the Avon Longitudinal Study of Parents and Children (England) were analysed using logistic regression to test whether inhibitory control and sensation seeking predicted participation in OAs at a mean age of 11.7 years (n = 2557) and 15.4 years (n = 2147). At 11 years of age higher sensation seeking predicted participation in any activity, sports and special groups while low inhibitory control predicted less participation in sports. At 15 years of age higher sensation seeking predicted participation in sports and activity breadth. Opportunities to develop targeted interventions aimed at increasing participation are discussed

Impacts of climate change on plant diseases – opinions and trends

There has been a remarkable scientific output on the topic of how climate change is likely to affect plant diseases in the coming decades. This review addresses the need for review of this burgeoning literature by summarizing opinions of previous reviews and trends in recent studies on the impacts of climate change on plant health. Sudden Oak Death is used as an introductory case study: Californian forests could become even more susceptible to this emerging plant disease, if spring precipitations will be accompanied by warmer temperatures, although climate shifts may also affect the current synchronicity between host cambium activity and pathogen colonization rate. A summary of observed and predicted climate changes, as well as of direct effects of climate change on pathosystems, is provided. Prediction and management of climate change effects on plant health are complicated by indirect effects and the interactions with global change drivers. Uncertainty in models of plant disease development under climate change calls for a diversity of management strategies, from more participatory approaches to interdisciplinary science. Involvement of stakeholders and scientists from outside plant pathology shows the importance of trade-offs, for example in the land-sharing vs. sparing debate. Further research is needed on climate change and plant health in mountain, boreal, Mediterranean and tropical regions, with multiple climate change factors and scenarios (including our responses to it, e.g. the assisted migration of plants), in relation to endophytes, viruses and mycorrhiza, using long-term and large-scale datasets and considering various plant disease control methods