The APPLE Tree programme: Active Prevention in People at risk of dementia through Lifestyle, bEhaviour change and Technology to build REsiliEnce-randomised controlled trial

BACKGROUND

Large-scale trials of multidomain interventions show that modifying lifestyle and psychological risk factors can slow cognitive decline. We aim to determine if a lower intensity, personally tailored secondary dementia prevention programme for older people with subjective or mild objective memory decline, informed by behaviour change theory, reduces cognitive decline over 2 years.

METHODS

A multi-site, single-blind randomised controlled trial recruiting 704 older adults at high dementia risk due to mild cognitive impairment (MCI) or subjective cognitive decline (SCD). Participants are randomised using 1:1 allocation ratio to the APPLE Tree intervention versus control arm (dementia prevention information), stratified by site. The intervention explores and implements strategies to promote healthy lifestyle, increase pleasurable activities and social connections and improve long-term condition self-management. Two facilitators trained and supervised by a clinical psychologist deliver ten, 1-h group video call sessions over 6 months (approximately every fortnight), video-call 'tea breaks' (less structured, facilitated social sessions) in intervening weeks and individual goal-setting phone calls every 2 weeks. From 6 to 12 months, participants meet monthly for 'tea breaks', with those not attending receiving monthly goal-setting phone calls. Participants receive a food delivery, pedometer and website access to cognitive training and information about lifestyle modification. Follow-ups for all outcome measures are at 12 and 24 months. The primary outcome is cognition (Neuropsychological Test Battery (NTB) score) at 24 months. Secondary outcomes are quality of life, cost per quality-adjusted life year (QALY) and wellbeing and lifestyle factors the intervention targets (diet, vascular risk, body weight, activity, sleep, anxiety, depression, social networks and loneliness, alcohol intake and smoking). Participants from purposively selected sites participate in qualitative process evaluation interviews, which will be analysed using thematic analytic methods.

DISCUSSION

If effective, the intervention design, involving remote delivery and non-clinical facilitators, would facilitate intervention roll-out to older people with memory concerns.

TRIAL REGISTRATION

ISRCTN17325135 . Registration date 27 November 2019.

Associations of Later-Life Education, the BDNF Val66Met Polymorphism and Cognitive Change in Older Adults

In 358 participants of the Tasmanian Healthy Brain Project, we quantified the cognitive consequences of engaging in varying loads of university-level education in later life, and investigated whether or not BDNF Val66Met affected outcomes. Assessment of neuropsychological, health, and psychosocial function was undertaken at baseline, 12-month, and 24-month follow-up. Education load was positively associated with change in language processing performance, but this effect did not reach statistical significance (P = 0.064). The BDNF Val66Met polymorphism significantly moderated the extent to which education load was associated with improved language processing (P = 0.026), with education load having a significant positive relationship with cognitive change in BDNF Met carriers but not in BDNF Val homozygotes. In older adults who carry BDNF Met, engaging in university-level education improves language processing performance in a load-dependent manner.

Decision making and vulnerability to suicidal behaviour in elderly

Suicide is a major public health concern, especially for older adults, who have higher rates of completed suicide than any other age group in most countries of the world. However, understanding suicidal behaviour remains a challenging task particularly among the elders who have been poorly studied. Decision making has been recently found to be altered in suicide attempters under 65.To test wether decision making would be a neuropsychological trait of vulnerability to suicidal behaviours, the authors used the Iowa Gambling Task to investigate normothymic non demented elders with a history of suicidal behaviour (N = 35) and compared it to decision making in non suicide attempters with a past history of depression (N = 52) and comparison subjects (N = 43). The data also were compared to those of similar groups of younger normothymic subjects. Moreover, the old suicidal patients were assessed according to the age at the onset of suicidal behaviour (before or after 60).Old suicide attempters did not significantly differ from the other aged groups and according to the age of first suicidal behaviour. Old suicide attempters presented better performances than that of younger suicidal patients.Vulnerability to suicidal behaviour in older people may proceed from cognitive processes which are different from the ones involved in suicidal vulnerability of younger subjects. These results are preliminary and further studies are needed to explore vulnerability cognitive patterns to suicide among elders.

Predicting pharmacy naloxone stocking and dispensing following a statewide standing order, Indiana 2016

BACKGROUND

While naloxone, the overdose reversal medication, has been available for decades, factors associated with its availability through pharmacies remain unclear. Studies suggest that policy and pharmacist beliefs may impact availability. Indiana passed a standing order law for naloxone in 2015 to increase access to naloxone.

OBJECTIVE

To identify factors associated with community pharmacy naloxone stocking and dispensing following the enactment of a statewide naloxone standing order.

METHODS

A 2016 cross-sectional census of Indiana community pharmacists was conducted following a naloxone standing order. Community, pharmacy, and pharmacist characteristics, and pharmacist attitudes about naloxone dispensing, access, and perceptions of the standing order were measured. Modified Poisson and binary logistic regression models attempted to predict naloxone stocking and dispensing, respectively.

RESULTS

Over half (58.1%) of pharmacies stocked naloxone, yet 23.6% of pharmacists dispensed it. Most (72.5%) pharmacists believed the standing order would increase naloxone stocking, and 66.5% believed it would increase dispensing. Chain pharmacies were 3.2 times as likely to stock naloxone. Naloxone stocking was 1.6 times as likely in pharmacies with more than one full-time pharmacist. Pharmacies where pharmacists received naloxone continuing education in the past two years were 1.3 times as likely to stock naloxone. The attempted dispensing model yielded no improvement over the constant-only model.

CONCLUSIONS

Pharmacies with larger capacity took advantage of the naloxone standing order. Predictors of pharmacist naloxone dispensing should continue to be explored to maximize naloxone access.

Frequent attendance and the concordance between PHQ screening and GP assessment in the detection of common mental disorders

OBJECTIVE

Frequent Attenders (FAs) have high rates of both common mental disorders (CMD) and physical disorders, partly justifying this service use behaviour. This study examines both case and non-case concordance between CMDs as estimated by a self-report screening questionnaire and as rated by the general practitioner (GP), in FAs compared to Other Attenders (OAs).

METHODS

2275 patients of an overlapping sample of 55 GPs from 2 surveys performed 10 years apart, completed in the waiting room the Patient Health Questionnaire (PHQ) and Client Service Receipt Inventory on 6-month service use. For each patient, the GP rated mental health on a 0-4 scale, with a clear indication that scores of 2 and above referred to caseness. PHQ-CMDs included major and other depressive, anxiety, panic, and somatoform disorders, identified using the original PHQ DSM-IV criteria-based algorithms. FA was defined as the top 10% of attenders in age, sex and survey-year stratified subgroups.

RESULTS

FAs had higher rates of PHQ-CMDs (42% versus 23% for OAs, p < .0001). They reported more personal and social problems, disability and had higher GP-rated physical illness. Survey-day antidepressant/anxiolytic medication prescription was higher for FAs (p < .0001), with (p = .02) but also without a CMD (p < .0001). Both GP/PHQ case and non-case concordance differed between FAs and OAs, with a non-case concordance odds ratio of 0.5 (95% CI: 0.3-0.7, p = .001) for FAs compared to OAs.

CONCLUSION

Despite a greater likelihood of GPs detecting CMDs in FAs, our findings suggest a potential risk of 'over-detection' of patients not reaching CMD threshold criteria among FAs.

Asymmetric polar localization dynamics of the serine chemoreceptor protein Tsr in Escherichia coli

The spatial location of proteins in living cells can be critical for their function. For example, the E. coli chemotaxis machinery is localized to the cell poles. Here we describe the polar localization of the serine chemoreceptor Tsr using a strain synthesizing a fluorescent Tsr-Venus fusion at a low level from a single-copy chromosomal construct. Using photobleaching and imaging during recovery by new synthesis, we observed distinct asymmetry between a bright (old) pole and a dim (new) pole. The old pole was shown to be a more stable cluster and to recover after photobleaching faster, which is consistent with the hypothesis that newly synthesized Tsr proteins are inserted directly at or near the old pole. The new pole was shown to be a less stable cluster and to exchange proteins freely with highly mobile Tsr-Venus proteins diffusing in the membrane. We propose that the new pole arises from molecules escaping from the old pole and diffusing to the new pole where a more stable cluster forms over time. Our localization imaging data support a model in which a nascent new pole forms prior to stable cluster formation.

MACVIA-LR (Fighting Chronic Diseases for Active and Healthy Ageing in Languedoc-Roussillon): A Success Story of the European Innovation Partnership on Active and Healthy Ageing

The Région Languedoc Roussillon is the umbrella organisation for an interconnected and integrated project on active and healthy ageing (AHA). It covers the 3 pillars of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA): (A) Prevention and health promotion, (B) Care and cure, (C) and (D) Active and independent living of elderly people. All sub-activities (poly-pharmacy, falls prevention initiative, prevention of frailty, chronic respiratory diseases, chronic diseases with multimorbidities, chronic infectious diseases, active and independent living and disability) have been included in MACVIA-LR which has a strong political commitment and involves all stakeholders (public, private, patients, policy makers) including CARSAT-LR and the Eurobiomed cluster. It is a Reference Site of the EIP on AHA. The framework of MACVIA-LR has the vision that the prevention and management of chronic diseases is essential for the promotion of AHA and for the reduction of handicap. The main objectives of MACVIA-LR are: (i) to develop innovative solutions for a network of Living labs in order to reduce avoidable hospitalisations and loss of autonomy while improving quality of life, (ii) to disseminate the innovation. The three years of MACVIA-LR activities are reported in this paper.

Setting the Scene: The Evidence for Pre-clinical Change, Projections of the Impact of Intervention, and Implications for Public Health

Alzheimer's disease has long been considered a neurodegenerative disorder of late life for which there is currently no disease-modifying treatment. This view is now being revised as increasing evidence suggests a long pre-clinical phase extending back into mid-life during which there is exposure to multiple potentially reversible risk factors. Further thought is now being given to the possibility of both early life intervention programs and development of new drug treatments focusing on the pre-dementia period. But how can the impact of such treatments be measured at this early stage since overt dementia may not be diagnosed for decades? In the four talks in this symposium, we will discuss evidence for pre-clinical change, theoretical models which have been used to project the possible impact of risk factor modification in mid-life and their integration into a future public health strategies. The development of new statistical risk models to determine the impact of such prevention measures will be outlined. We will consider the possibilities for drug development targeting the pre-clinical period before presenting the PREVENT Project and EPAD (http://ep-ad.org/), a multi-million euro IMI-Horizon 2020 funded project for the development of pre-clinical proof of concept trials. Titles of the four presentations: 1. Setting the scene: the evidence for pre-clinical change, projections of the impact of intervention, and implications for public health (TCR) 2. New statistical risk models for determining the impact of prevention measures in the pre-dementia period (GMT) 3. The PREVENT Study: a prospective cohort study to identify mid-life biomarkers of late-onset Alzheimer's disease (KR) 4. The European Prevention of Alzheimer's Dementia (EPAD) Project: developing interventions for the secondary prevention of Alzheimer's dementia (CWR)

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Association Between Lifetime Headache and History of Suicide Attempts in the Elderly

Background

Pain-related conditions have been reported to play a key role among risk factors for suicide. Headache in particular has been repeatedly associated with suicidal thoughts and behaviors. The aims of this study were: 1) to assess the association between lifetime headache (both non-migrainous headache and migraine) and lifetime suicide attempts (SA); 2) to differentiate, within subjects with lifetime SA, patients with and without lifetime headache in terms of socio-demographic and clinical features.

Methods

We studied 1965 subjects from a cohort of community-dwelling persons aged 65 years and over without dementia (the ESPRIT study), divided in two groups: those with (n = 75), and those without a lifetime SA (n = 1890). Logistic regression analyses were used to compare these groups according to lifetime headache status.

Results

After adjusting for gender, living alone, tobacco and alcohol consumption, and depressive, manic/hypomanic and anxiety disorders, lifetime headache frequency was significantly higher in subjects with a lifetime SA compared with controls (OR = 1.92 [1.17–3.15]). Additionally, different factors were identified as being associated with lifetime SA in participants with lifetime headache (female gender, a lower level of high-density lipoprotein cholesterol, insomnia, lifetime major depression) versus participants without headache (glycemia and lifetime major depression).

Conclusions

Lifetime headache was associated with lifetime SA. Subjects who are women and report the co-occurrence of headache and insomnia as well as lifetime major depression require higher attention and a careful screening for suicidal thoughts and behaviors.

Confined Mobility of TonB and FepA in Escherichia coli Membranes

The important process of nutrient uptake in Escherichia coli, in many cases, involves transit of the nutrient through a class of beta-barrel proteins in the outer membrane known as TonB-dependent transporters (TBDTs) and requires interaction with the inner membrane protein TonB. Here we have imaged the mobility of the ferric enterobactin transporter FepA and TonB by tracking them in the membranes of live E. coli with single-molecule resolution at time-scales ranging from milliseconds to seconds. We employed simple simulations to model/analyze the lateral diffusion in the membranes of E.coli, to take into account both the highly curved geometry of the cell and artifactual effects expected due to finite exposure time imaging. We find that both molecules perform confined lateral diffusion in their respective membranes in the absence of ligand with FepA confined to a region 0.180−0.007+0.006 μm in radius in the outer membrane and TonB confined to a region 0.266−0.009+0.007 μm in radius in the inner membrane. The diffusion coefficient of these molecules on millisecond time-scales was estimated to be 21−5+9 μm²/s and 5.4−0.8+1.5 μm²/s for FepA and TonB, respectively, implying that each molecule is free to diffuse within its domain. Disruption of the inner membrane potential, deletion of ExbB/D from the inner membrane, presence of ligand or antibody to FepA and disruption of the MreB cytoskeleton was all found to further restrict the mobility of both molecules. Results are analyzed in terms of changes in confinement size and interactions between the two proteins.

Single Molecule Studies of the Diffusion of Band 3 in Sickle Cell Erythrocytes

Sickle cell disease (SCD) is caused by an inherited mutation in hemoglobin that leads to sickle hemoglobin (HbS) polymerization and premature HbS denaturation. Previous publications have shown that HbS denaturation is followed by binding of denatured HbS (a.k.a. hemichromes) to band 3, the consequent clustering of band 3 in the plane of the erythrocyte membrane that in turn promotes binding of autologous antibodies to the clustered band 3, and removal of the antibody-coated erythrocytes from circulation. Although each step of the above process has been individually demonstrated, the fraction of band 3 that is altered by association with denatured HbS has never been determined. For this purpose, we evaluated the lateral diffusion of band 3 in normal cells, reversibly sickled cells (RSC), irreversibly sickled cells (ISC), and hemoglobin SC erythrocytes (HbSC) in order to estimate the fraction of band 3 that was diffusing more slowly due to hemichrome-induced clustering. We labeled fewer than ten band 3 molecules per intact erythrocyte with a quantum dot to avoid perturbing membrane structure and we then monitored band 3 lateral diffusion by single particle tracking. We report here that the size of the slowly diffusing population of band 3 increases in the sequence: normal cells<HbSC<RSC<ISC. We also demonstrate that the size of the compartment in which band 3 is free to diffuse decreases roughly in the same order, with band 3 diffusing in two compartments of sizes 35 and 71 nm in normal cells, but only a single compartment in HbSC cells (58 nm), RSC (45 nm) and ISC (36 nm). These data suggest that the mobility of band 3 is increasingly constrained during SCD progression, suggesting a global impact of the mutated hemoglobin on erythrocyte membrane properties.

Diffusion of glycophorin A in human erythrocytes

Several lines of evidence suggest that glycophorin A (GPA) interacts with band 3 in human erythrocyte membranes including: i) the existence of an epitope shared between band 3 and GPA in the Wright b blood group antigen, ii) the fact that antibodies to GPA inhibit the diffusion of band 3, iii) the observation that expression of GPA facilitates trafficking of band 3 from the endoplasmic reticulum to the plasma membrane, and iv) the observation that GPA is diminished in band 3 null erythrocytes. Surprisingly, there is also evidence that GPA does not interact with band 3, including data showing that: i) band 3 diffusion increases upon erythrocyte deoxygenation whereas GPA diffusion does not, ii) band 3 diffusion is greatly restricted in erythrocytes containing the Southeast Asian Ovalocytosis mutation whereas GPA diffusion is not, and iii) most anti-GPA or anti-band 3 antibodies do not co-immunoprecipitate both proteins. To try to resolve these apparently conflicting observations, we have selectively labeled band 3 and GPA with fluorescent quantum dots in intact erythrocytes and followed their diffusion by single particle tracking. We report here that band 3 and GPA display somewhat similar macroscopic and microscopic diffusion coefficients in unmodified cells, however perturbations of band 3 diffusion do not cause perturbations of GPA diffusion. Taken together the collective data to date suggest that while weak interactions between GPA and band 3 undoubtedly exist, GPA and band 3 must have separate interactions in the membrane that control their lateral mobility.

Are migraine and non-migrainous headache risk factors for stroke in the elderly? Findings from a 12-year cohort follow-up

BACKGROUND AND PURPOSE

There is evidence that migraine is a risk factor for stroke but little is known about this association in elderly people. Furthermore, non-migrainous headache (NMH) has received little attention despite being the most frequently reported type of headache. Late-life migraine and NMH were examined as candidate risk factors for stroke in a community-dwelling elderly sample over a 12-year follow-up.

METHODS

One thousand nine hundred and nineteen non-institutionalized subjects aged 65+, without dementia (Diagnostic and Statistical Manual of Mental Disorders, 4th edition, DSM-IV criteria) and with no stroke history at baseline, were drawn from the Three-City Montpellier cohort (recruitment 1999-2001) for longitudinal analysis. Ischaemic and haemorrhagic stroke was reported at baseline and at each of the five follow-ups, with cases validated by a panel of experts, according to ICD-10 criteria (International Classification of Diseases, 10th revision). Migraine and NMH were determined at baseline during a neurological interview and examination using 1988 International Headache Society criteria.

RESULTS

A total of 110 (5.4%) cases of migraine and 179 (8.9%) cases of NMH were identified at baseline. During the median 8.8-year follow-up, incident stroke was observed in 1.9% of baseline migrainers, 6.2% of NMH and 3.6% of those with no lifetime history of headache. Cox proportional hazard models indicated that migraine was not a risk factor for stroke; however, NMH sufferers were twice as likely to have a stroke (hazard ratio 2.00, 95% confidence interval 1.00-3.93, P = 0.049).

CONCLUSIONS

This study is one of the first to suggest that late-life NMH rather than migraine could be an independent risk factor for stroke and a warning sign. The incidence of stroke in elderly migrainers, seldom reported, is particularly low.

Biological and psychological predictors of posttraumatic stress disorder onset and chronicity. A one-year prospective study

BACKGROUND

Few studies have prospectively examined risk factors for posttraumatic stress disorder (PTSD) in the aftermath of a traumatic exposure. The aim of this study is to identify the concurrent influence of psychological and biological diatheses on PTSD onset and maintenance, taking into account socio-demographic factors and psychiatric antecedents.

METHODS

A total of 123 civilians (61.8% of women) recruited in emergency units, were assessed using validated instruments during the first week and then at 1, 4, and 12 months post-trauma. Baseline assessment included evaluation of the psychological diathesis (i.e. psychiatric history and peritraumatic distress and dissociation), and the biological diathesis [i.e. cortisol, norepinephrine, epinephrine, c-reactive protein, total cholesterol, HDL cholesterol, glycosylated haemoglobin, waist-to-hip ratio (WHR), body mass index, diastolic and systolic blood pressure (SBP), and heart rate].

RESULTS

Multivariate logistic regression analyses demonstrated both psychological and biological diatheses to be independent risk factors for PTSD. Peritraumatic distress and dissociation predicted onset (1-month) and mid-term PTSD (4-months), respectively. PTSD risk was associated positively with SBP and negatively with WHR, throughout the follow-up. In addition, a higher level of 12 h-overnight urinary norepinephrine independently predicted mid-term PTSD (4-months).

CONCLUSIONS

This prospective study shows that peritraumatic psychological and biological markers are independent predictors of PTSD onset with specificities according to the stage of PTSD development; the psychological diathesis, i.e. peritraumatic distress and dissociation, being a better predictor of short-term dysfunction whereas biological diathesis was also predictive of development and maintenance of PTSD.

The impact of septoplasty on health-related quality of life in paediatric patients

OBJECTIVES

To assess the impact that septoplasty had on health-related quality of life (HRQoL) in paediatric patients and to determine whether there were patient characteristics that predicted better outcomes.

DESIGN

Retrospective cohort study.

SETTING

Academic paediatric otolaryngology practice.

PARTICIPANTS

All paediatric patients who underwent septoplasty during the study period.

MAIN OUTCOME MEASURES

The current HRQoL was assessed using the Paediatric Quality of Life Inventory (PedsQL). The Glasgow Children's Benefit Inventory (GCBI) was used to evaluate the perceived change in HRQoL following septoplasty.

RESULTS

A total of 29 patients (16 boys, mean age 13 years) and their caregivers responded (response rate of 72.5%). There was a statistically significant improvement in HRQoL following septoplasty, as demonstrated by the positive mean GCBI subscores and the total GCBI score (35.1, sd = 28.4). The total mean PedsQL score for child self-report was 95.2 (sd = 6.9) and for parent-proxy report was 91.8 (sd = 8.6), which indicated good current HRQoL. The enhancement in HRQoL post-septoplasty was moderately correlated with self-reported degree of nasal obstruction pre-septoplasty (r = 0.621 for total GCBI). Also, there were differences in GCBI scores between the groups of children who wanted to have the surgery versus those who did not want to have the surgery.

CONCLUSIONS

There was a significant positive change in HRQoL following paediatric septoplasty in our study population. Children who reported more severe nasal obstruction and those who wanted to have the surgery were more likely to experience enhancement of HRQoL following their surgery.

Late-onset agoraphobia: General population incidence and evidence for a clinical subtype

The general population prevalence and incidence of late-life agoraphobia was estimated and its clinical characteristics and risk factors described using data from the French ESPRIT study. One thousand nine hundred and sixty-eight persons aged 65 and above were randomly recruited from the electoral rolls of the district of Montpellier. Prevalent and incident agoraphobia diagnosed by a standardized psychiatric examination and validated by a clinical panel was assessed at base-line and over 4-year follow-up. The one-month prevalence of agoraphobia was estimated at 10.4% of whom 10.9% reported having the first-episode at age 65 or over. During the 4-year follow-up 11.2% of participants without agoraphobia at base line were classified as cases giving an incident rate of 32 per 1000 person-years. These 132 incident late-onset cases were associated with higher incident rates of anxiety disorders and suicidal ideation. Only two incident cases had past or concurrent panic attacks, which was not significantly different from non-cases. The principal base-line risk factors for incident cases derived from a multivariate model incorporating all significant risk factors were younger age of onset (OR = 0.94; 95% CI 0.90–0.99, P = 0.02), poorer visuospatial memory performance (OR = 1.60; 95% CI 1.02–2.49, P = 0.04), severe depression (OR = 2.62; 95% CI 1.34–5.10, P = 0.005) and trait anxiety (OR = 1.73; 95% CI 1.03–2.90, P = 0.04). No significant association was found with cardiac pathologies. We conclude that agoraphobia has high prevalence in the elderly and unlike younger cases, late-onset cases are not more common in women, and are not associated with panic attacks, suggesting a late-life subtype. Severe depression, trait anxiety and poor visuospatial memory are the principal risk factors for late-onset agoraphobia.

Operational Definition of Active and Healthy Ageing (AHA): A Conceptual Framework

Health is a multi-dimensional concept, capturing how people feel and function. The broad concept of Active and Healthy Ageing was proposed by the World Health Organisation (WHO) as the process of optimizing opportunities for health to enhance quality of life as people age. It applies to both individuals and population groups. A universal Active and Healthy Ageing definition is not available and it may differ depending on the purpose of the definition and/or the questions raised. While the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) has had a major impact, a definition of Active and Healthy Ageing is urgently needed. A meeting was organised in Montpellier, France, October 20-21, 2014 as the annual conference of the EIP on AHA Reference Site MACVIA-LR (Contre les Maladies Chroniques pour un Vieillissement Actif en Languedoc Roussillon) to propose an operational definition of Active and Healthy Ageing including tools that may be used for this. The current paper describes the rationale and the process by which the aims of the meeting will be reached.

BDNF promoter methylation and genetic variation in late-life depression

The regulation of the brain-derived neurotrophic factor (BDNF) is important for depression pathophysiology and epigenetic regulation of the BDNF gene may be involved. This study investigated whether BDNF methylation is a marker of depression. One thousand and twenty-four participants were recruited as part of a longitudinal study of psychiatric disorders in general population elderly (age ⩾ 65). Clinical levels of depression were assessed using the Mini International Neuropsychiatric Interview for the diagnosis of major depressive disorder according to the Diagnostic and Statistical Manual of Mental Disorder IV criteria, and the Centre for Epidemiologic Studies Depression Scale (CES-D) for assessment of moderate to severe depressive symptoms. Buccal DNA methylation at the two most widely studied BDNF promoters, I and IV, was investigated using the Sequenom MassARRAY platform that allows high-throughput investigation of methylation at individual CpG sites within defined genomic regions. In multivariate linear regression analyses adjusted for a range of participant characteristics including antidepressant use, depression at baseline, as well as chronic late-life depression over the 12-year follow-up, were associated with overall higher BDNF methylation levels, with two sites showing significant associations (promoter I, Δ mean = 0.4%, P = 0.0002; promoter IV, Δ mean = 5.4%, P = 0.021). Three single-nucleotide polymorphisms (rs6265, rs7103411 and rs908867) were also found to modify the association between depression and promoter I methylation. As one of the largest epigenetic studies of depression, and the first investigating BDNF methylation in buccal tissue, our findings highlight the potential for buccal BDNF methylation to be a biomarker of depression.

Risk factors for late-onset generalized anxiety disorder: results from a 12-year prospective cohort (the ESPRIT study)

Generalized anxiety disorder (GAD) is a chronic and highly prevalent disorder associated with increased disability and mortality in the elderly. Treatment is difficult with low rate of full remission, thus highlighting the need to identify early predictors for prevention in elderly people. The aim of this study is to identify and characterize incident GAD predictors in elderly people. A total of 1711 individuals aged 65 years and above and free of GAD at baseline were randomly recruited from electoral rolls between 1999 and 2001 (the prospective ESPRIT study). The participants were examined at baseline and five times over 12 years. GAD and psychiatric comorbidity were diagnosed with a standardized psychiatric examination, the Mini-International Neuropsychiatry Interview on the basis of DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, fourth edition) criteria and validated by a clinical panel. During the follow-up, 8.4% (95% confidence interval=7.1-9.7%) of the participants experienced incident GAD, 80% being first episodes; the incident rate being 10 per 1000 person-years. The principal predictors of late-onset incident GAD over 12 years derived from a multivariate Cox model were being female, recent adverse life events, having chronic physical (respiratory disorders, arrhythmia and heart failure, dyslipidemia, cognitive impairment) and mental (depression, phobia and past GAD) health disorders. Poverty, parental loss or separation and low affective support during childhood, as well as history of mental problems in parents were also significantly and independently associated with incident GAD. GAD appears as a multifactorial stress-related affective disorder resulting from both proximal and distal risk factors, some of them being potentially modifiable by health care intervention.

Developmental determinants in non-communicable chronic diseases and ageing

Prenatal and peri-natal events play a fundamental role in health, development of diseases and ageing (Developmental Origins of Health and Disease (DOHaD)). Research on the determinants of active and healthy ageing is a priority to: (i) inform strategies for reducing societal and individual costs of an ageing population and (ii) develop effective novel prevention strategies. It is important to compare the trajectories of respiratory diseases with those of other chronic diseases.

Late-life depression

Late-life depression is highly heterogeneous in clinical presentation, and is also commonly resistant to treatment. While some cases are a continuation of the chronic course of illness beginning in early adulthood, a large number of persons will have a first episode of depression in later life following alife-time of relatively good mental health. While incident cases of major depression tend to decrease with age, the number of persons with clinically significant depressive symptomatology rises. À distinction has often been made between early-onset and late-onset depression, however, there is no conclusive evidence to suggest these are distinct clinical entities. On the other hand observations from a fifteen year prospective population study of psychiatric disorder in the elderly (the ESPRIT Study) supports the alternative idea that depression may be divided into sub-types according to postulated aetiology; for example depression with a strong genetic component, related to hormonal changes, the consequence of trauma; the result of cerebrovascular insult. Exposure to these putative causes may be more common at different points in the life span, thus suggesting age-differences. Our research further suggests that even cases of depression appearing for the first time in late-life, may be initially triggered by risk factors occurring decades before. Our findings suggest, for example, that childhood events may lead to changes in the biology of stress management, which continue throughout life, increasing vulnerability to depression and persisting even after effective treatment of symptoms. Together these observations suggest it may be more meaningful to classify depression in the elderly according to probable principle precipitating factors rather than age.

Dynamics of the serine chemoreceptor in the Escherichia coli inner membrane: a high-speed single-molecule tracking study

We investigated the mobility of the polar localized serine chemoreceptor, Tsr, labeled by the fluorescent protein Venus in the inner membrane of live Escherichia coli cells at observation rates up to 1000 Hz. A fraction (7%) of all Tsr molecules shows free diffusion over the entire cell surface with an average diffusion coefficient of 0.40 ± 0.01 μm(2) s(-1). The remaining molecules were found to be ultimately confined in compartments of size 290 ± 15 nm and showed restricted diffusion at an inner barrier found at 170 ± 10 nm. At the shortest length-scales (<170 nm), all Tsr molecules diffuse equally. Disruption of the cytoskeleton and rounding of the cells resulted in an increase in the mobile fraction of Tsr molecules and a fragmenting of the previously polar cluster of Tsr consistent with a curvature-based mechanism of Tsr cluster maintenance.

Impact of a premature menopause on cognitive function in later life

OBJECTIVE

To determine whether premature menopause (≤40 years) can have long-lasting effects on later-life cognition and investigate whether this association varies depending on the type of menopause and use of hormone treatment (HT).

DESIGN

Population-based cohort study.

SETTING

The French Three-City Study.

POPULATION

Four thousand eight hundred and sixty-eight women aged at least 65 years.

METHODS

Multivariable-adjusted logistic regression models were used to determine the association between age at menopause, type of menopause (surgical, natural), and the use of menopausal HT and later-life cognitive function.

MAIN OUTCOME MEASURES

Performance on a cognitive test battery (at baseline and over 7 years) and clinical dementia diagnosis.

RESULTS

Menopause at or before the age of 40 years, both premature bilateral ovariectomy and premature ovarian failure (non-surgical loss of ovarian function), was associated with worse verbal fluency (OR 1.56, 95%CI 1.12-1.87, P=0.004) and visual memory (OR 1.39, 95%CI 1.09-1.77, P=0.007) in later life. HT at the time of premature menopause appeared beneficial for later-life visual memory but increased the risk of poor verbal fluency. Type of menopause was not significantly associated with cognitive function. Premature menopause was associated with a 30% increased risk of decline in psychomotor speed and global cognitive function over 7 years.

CONCLUSION

Both premature surgical menopause and premature ovarian failure were associated with long-term negative effects on cognitive function, which are not entirely offset by menopausal HT. In terms of surgical menopause, these results suggest that the potential long-term effects on cognitive function should form part of the risk/benefit ratio when considering ovariectomy in younger women.

Meta-analysis of 74,046 individuals identifies 11 new susceptibility loci for Alzheimer's disease

Eleven susceptibility loci for late-onset Alzheimer's disease (LOAD) were identified by previous studies; however, a large portion of the genetic risk for this disease remains unexplained. We conducted a large, two-stage meta-analysis of genome-wide association studies (GWAS) in individuals of European ancestry. In stage 1, we used genotyped and imputed data (7,055,881 SNPs) to perform meta-analysis on 4 previously published GWAS data sets consisting of 17,008 Alzheimer's disease cases and 37,154 controls. In stage 2, 11,632 SNPs were genotyped and tested for association in an independent set of 8,572 Alzheimer's disease cases and 11,312 controls. In addition to the APOE locus (encoding apolipoprotein E), 19 loci reached genome-wide significance (P < 5 × 10(-8)) in the combined stage 1 and stage 2 analysis, of which 11 are newly associated with Alzheimer's disease.

Biocompatible fluorescent silicon nanocrystals for single-molecule tracking and fluorescence imaging

Fluorescence microscopy is used extensively in cell-biological and biomedical research, but it is often plagued by three major problems with the presently available fluorescent probes: photobleaching, blinking, and large size. We have addressed these problems, with special attention to single-molecule imaging, by developing biocompatible, red-emitting silicon nanocrystals (SiNCs) with a 4.1-nm hydrodynamic diameter. Methods for producing SiNCs by simple chemical etching, for hydrophilically coating them, and for conjugating them to biomolecules precisely at a 1:1 ratio have been developed. Single SiNCs neither blinked nor photobleached during a 300-min overall period observed at video rate. Single receptor molecules in the plasma membrane of living cells (using transferrin receptor) were imaged for ≥10 times longer than with other probes, making it possible for the first time to observe the internalization process of receptor molecules at the single-molecule level. Spatial variations of molecular diffusivity in the scale of 1-2 µm, i.e., a higher level of domain mosaicism in the plasma membrane, were revealed.

Single molecule probe scanning optical force imaging microscopefor viewing live cells

We have developed an imaging system that combines the soft compliance of an optical trap with the sensitivity of single particle tracking to image forces on/in live cells using a single molecule probe. The probe used is a single (or few) molecule of interest that is conjugated with a single 40 nm colloidalgold probe. The colloidal gold/membrane protein complex, freely diffusing on a live cell, is held in a laser trap while the cell is scanned underneath. Computer control allows for synchronization of the cell scan and capture of the probe position. Resistance to the dragging of the probe images a fine structure of barriers in the membrane of live cells.

Single-molecule imaging in live bacteria cells

Bacteria, such as Escherichia coli and Caulobacter crescentus, are the most studied and perhaps best-understood organisms in biology. The advances in understanding of living systems gained from these organisms are immense. Application of single-molecule techniques in bacteria have presented unique difficulties owing to their small size and highly curved form. The aim of this review is to show advances made in single-molecule imaging in bacteria over the past 10 years, and to look to the future where the combination of implementing such high-precision techniques in well-characterized and controllable model systems such as E. coli could lead to a greater understanding of fundamental biological questions inaccessible through classic ensemble methods.

Single-molecule study of molecular mobility in the cytoplasm of Escherichia coli

The cytoplasm of bacterial cells is filled with individual molecules and molecular complexes that rely on diffusion to bring them together for interaction. The mobility of molecules in the cytoplasm has been characterized by several techniques mainly using fluorescent probes and ensemble methods. In order to probe the microenvrionment inside the cytoplasm as viewed by an individual molecule, we have studied single green fluorescent proteins (GFPs) diffusing in the cytoplasm of Escherichia coli cells at observation at rates ranging from 60 to 1000 Hz. Over long times the diffusion shows confinement due to the geometry of the cells themselves. A simulation in model cells using the actual distribution of cell sizes found in the experiments describes accurately the experimental results as well as reveals a short time diffusion coefficient that agrees well with that determined by ensemble methods. Higher short time diffusion coefficients can be obtained by filling the simulated cell with small spheres modeling cytoplasmic molecules and, depending on the density of particles included in the modeled cytoplasm, can approach the diffusion coefficient of GFPs found in water. Thus, single-molecule tracking combined with analysis using simple simulation of Brownian motion is able to reveal the main contributors to the GFP mobility in the cytoplasm of E. coli.

Antihypertensives for combating dementia? A perspective on candidate molecular mechanisms and population-based prevention

Age-related increases in prevalent dementia over the next 30-40 years risk collapsing medical resources or radically altering the way we treat patients. Better prevention of dementia therefore needs to be one of our highest medical priorities. We propose a perspective on the pathological basis of dementia based on a cerebrovascular-Alzheimer disease spectrum that provides a more powerful explanatory framework when considering the impact of possible public health interventions. With this in mind, a synthesis of evidence from basic, clinical and epidemiological studies indeed suggests that the enhanced treatment of hypertension could be effective for the primary prevention of dementia of either Alzheimer or vascular etiology. In particular, we focus on candidate preventative mechanisms, including reduced cerebrovascular disease, disruption of hypoxia-dependent amyloidogenesis and the potential neuroprotective properties of calcium channel blockers. Following the successful translation of large, long-term and resource-intense trials in cardiology into improved vascular health outcomes in many countries, new multinational prevention trials with dementia-related primary outcomes are now urgently required.

Analysis of the mobilities of band 3 populations associated with ankyrin protein and junctional complexes in intact murine erythrocytes

Current models of the erythrocyte membrane depict three populations of band 3: (i) a population tethered to spectrin via ankyrin, (ii) a fraction attached to the spectrin-actin junctional complex via adducin, and (iii) a freely diffusing population. Because many studies of band 3 diffusion also distinguish three populations of the polypeptide, it has been speculated that the three populations envisioned in membrane models correspond to the three fractions observed in diffusion analyses. To test this hypothesis, we characterized band 3 diffusion by single-particle tracking in wild-type and ankyrin- and adducin-deficient erythrocytes. We report that ∼40% of total band 3 in wild-type murine erythrocytes is attached to ankyrin, whereas ∼33% is immobilized by adducin, and ∼27% is not attached to any cytoskeletal anchor. More detailed analyses reveal that mobilities of individual ankyrin- and adducin-tethered band 3 molecules are heterogeneous, varying by nearly 2 orders of magnitude and that there is considerable overlap in diffusion coefficients for adducin and ankyrin-tethered populations. Taken together, the data suggest that although the ankyrin- and adducin-immobilized band 3 can be monitored separately, significant heterogeneity still exists within each population, suggesting that structural and compositional properties likely vary considerably within each band 3 complex.

Hierarchical mesoscale domain organization of the plasma membrane

Based on recent single-molecule imaging results in the living cell plasma membrane, we propose a hierarchical architecture of three-tiered mesoscale (2-300nm) domains to represent the fundamental functional organization of the plasma membrane: (i) membrane compartments of 40-300nm in diameter due to the partitioning of the entire plasma membrane by the actin-based membrane skeleton 'fence' and transmembrane protein 'pickets' anchored to the fence; (ii) raft domains (2-20nm); and (iii) dimers/oligomers and greater complexes of membrane-associated proteins (3-10nm). The basic molecular interactions required for the signal transduction function of the plasma membrane can be fundamentally understood and conveniently summarized as the cooperative actions of these mesoscale domains, where thermal fluctuations/movements of molecules and weak cooperativity play crucial roles.