Population-based neuropathological studies of dementia: design, methods and areas of investigation – a systematic review

Background Prospective population-based neuropathological studies have a special place in dementia research which is under emphasised. Methods A systematic review of the methods of population-based neuropathological studies of dementia was carried out. These studies were assessed in relation to their representativeness of underlying populations and the clinical, neuropsychological and neuropathological approaches adopted. Results Six studies were found to be true population-based neuropathological studies of dementia in the older people: the Hisayama study (Japan); Vantaa 85+ study (Finland); CC75C study (Cambridge, UK); CFAS (multicentre, UK); Cache County study (Utah, USA); HAAS (Hawaï, USA). These differ in the core characteristics of their populations. The studies used standardised neuropathological methods which facilitate analyses on: clinicopathological associations and confirmation of diagnosis, assessing the validity of hierarchical models of neuropathological lesion burden; investigating the associations between neuropathological burden and risk factors including genetic factors. Examples of findings are given although there is too little overlap in the areas investigated amongst these studies to form the basis of a systematic review of the results. Conclusion Clinicopathological studies based on true population samples can provide unique insights in dementia. Individually they are limited in power and scope; together they represent a powerful source to translate findings from laboratory to populations

Changes in Mood States Are Induced by Smelling Familiar and Exotic Fragrances

Abstract Familiar fragrances usually induce positive mood states and elicit favorable evaluation. Relaxation is also widely thought to improve mood state. Yet experimental evidence on the effect of two different stimuli, fragrance smelling and breathing relaxation, on mood state and fragrance evaluation is lacking. This study aimed to test (1) the effect of two familiar fragrances, lavender and myrtle, and two exotic fragrances, bergamot and ravensara, on perceived mood states before and after relaxation, (2) the effect of relaxation on perceived mood states for each fragrance, and (3) the effect of relaxation on fragrance evaluation as defined by adjectives. We hypothesized that mood states and assessment of the fragrances would differently be affected both in familiar vs. non-familiar fragrances and also before and after relaxation. Participants (n = 127) completed questionnaires on their mood states at baseline (T0). They were then presented with each of the four fragrances separately and asked to report on mood state and to assess the fragrances with adjectives before (T1) and after (T2) breathing relaxation. Analyses of the T0−T1 delta values of mood states by ANOVA repeated measures and post hoc comparisons showed that mood states were affected by fragrance smelling with no clear differences observed between familiar and exotic fragrances. The same analyses of T1−T2 values showed no differences in mood state after breathing relaxation and fragrance smelling. Fragrance assessment by adjectives indicated a non-conclusive trend for familiar and exotic fragrances. In sum, mood states induced by the fragrance smelling stimulus (T0−T1) were not changed by the addition of the second stimulus of relaxation (T1−T2), indicating that the former stimulus was stronger than the latter. On the other hand, the cognitive component represented by adjective-based assessment of fragrances was slightly modified by the relaxation stimulus

Population-based neuropathological studies of dementia: design, methods and areas of investigation--a systematic review.

BACKGROUND: Prospective population-based neuropathological studies have a special place in dementia research which is under emphasised. METHODS: A systematic review of the methods of population-based neuropathological studies of dementia was carried out. These studies were assessed in relation to their representativeness of underlying populations and the clinical, neuropsychological and neuropathological approaches adopted. RESULTS: Six studies were found to be true population-based neuropathological studies of dementia in the older people: the Hisayama study (Japan); Vantaa 85+ study (Finland); CC75C study (Cambridge, UK); CFAS (multicentre, UK); Cache County study (Utah, USA); HAAS (Hawaï, USA). These differ in the core characteristics of their populations. The studies used standardised neuropathological methods which facilitate analyses on: clinicopathological associations and confirmation of diagnosis, assessing the validity of hierarchical models of neuropathological lesion burden; investigating the associations between neuropathological burden and risk factors including genetic factors. Examples of findings are given although there is too little overlap in the areas investigated amongst these studies to form the basis of a systematic review of the results. CONCLUSION: Clinicopathological studies based on true population samples can provide unique insights in dementia. Individually they are limited in power and scope; together they represent a powerful source to translate findings from laboratory to populations

Regards croisés du MEDD et du PUCA sur l'état des recherches françaises en matière d'inégalités écologiques

Evelyne Lemercier, du Plan Urbanisme Construction et Architecture (PUCA) et Gérard Guillaumin Ministère de l’Ecologie et du Développement Durable (MEDD) ont bien voulu répondre aux questions des responsables de ce dossier, afin d'illustrer leurs points de vue en tant que commanditaires et utilisateurs de recherches. E. Zaccaï : Pourquoi les institutions auxquelles vous appartenez ont-elles lancé des programmes de recherches relatives aux inégalités écologiques ? E. Lemercier & G. Guillaumin :..

Les scientifiques et les fonctions d’intellectuel

Le sujet de cette contribution trouve son origine dans un certain étonnement à constater la présence relativement faible de scientifiques parmi les intellectuels reconnus, en dépit de l’importance majeure des sciences dans les sociétés. Certains éléments explicatifs sont proposés tels que la moindre demande pour ce type de savoir dans le public, et du côté interne aux universités, des formations disciplinaires et méthodes d’évaluation qui n’incitent pas à ces prises de parole.L’article est construit à travers l’analyse de cinq catégories de prise de position, ou de “fonction” d’intellectuel. Trois d’entre elles concernent de larges publics et des discours influents : se prononcer sur un sujet de sa spécialité, se prononcer sur les implications de sa discipline, prendre position sur tout type de sujet. Une quatrième catégorie concerne des collaborations plus ponctuelles de type “science citoyenne”. La cinquième enfin porte sur la gestion académique et professionnelle des domaines de savoirs.The topic of this paper is rooted in some kind of astonishment at the relatively weak part of scientists among recognized intellectuals despite the major importance of sciences in societies. Some reasons are put forward, such as a lower demand for this type of knowledge among the public but also in universities, which offer disciplinary trainings as well as assessment methods that fail to encourage such expressions.The paper is based on the analysis of five categories of statements, or “functions” of intellectuals. Three of them concern a large public along with influential speeches: expressing oneself on a topic from one’s area of expertise; on the implications of one’s discipline; on any kind of issue. A fourth category concerns more occasional collaborations such as “citizen science”. The last category addresses the academic and professional management of the fields of knowledge

Alpha-synucleinopathy and neuropsychological symptoms in a population-based cohort of the elderly

Introduction Studies with strong selection biases propose that alpha-synucleinopathy (AS) spreads upwards and downwards in the neuraxis from the medulla, that amygdala-dominant AS is strongly associated with Alzheimer’s disease (AD), and that a more severe involvement of the cerebral cortex is correlated with increasing risk of dementia. This study examines the association of AS patterns and observed neuropsychological symptoms in brains of a population-representative donor cohort. Methods Brains donated in 2 out of 6 cognitive function and ageing study cohorts (Cambridgeshire and Nottingham) were examined. Over 80% were >80 years old at death. The respondents were evaluated prospectively in life for cognitive decline and dementia. Immunocytochemistry for tau and alpha-synuclein (using LB509 by Zymed Laboratories) was carried out in 208 brains to establish Braak stage and the pattern and severity of AS following the dementia with Lewy bodies (DLB) consensus recommendations. Dementia, specific neuropsychological measures as measured using the Cambridge cognitive examination, the presence of hallucinations and Parkinson’s disease were investigated. Results Four patterns of AS were observed: no AS pathology (n = 92), AS pathology following the DLB consensus guidelines (n = 33, of which five were ‘neocortical’), amygdala-predominant AS (n = 18), and other AS patterns (n = 33). Each group was subdivided according to high/low neurofibrillary tangles (NFT) Braak stage. Results showed no association between dementia and these patterns of AS, adjusting for the presence of NFT or not. The risk of visual hallucinations shows a weak association with AS in the substantia nigra (odds ratio (OR) = 3.2; 95% confidence interval (CI) 0.5 to 15.5; P = 0.09) and amygdala (OR = 3.0; 95% CI 0.7 to 12.3; P = 0.07). The analysis is similar for auditory hallucinations in subcortical regions. Conclusions Among the whole population of older people, AS does not increase the risks for dementia, irrespective of Braak stage of NFT pathology. There was no evidence that the pattern of AS pathology in cortical areas was relevant to the risk of hallucination. In general, the hypothesis that AS as measured using these methods per se is a key determinant of cognitive clinical phenotypes is not supported

Picosecond fluctuating protein energy landscape mapped by pressure–temperature molecular dynamics simulation

Microscopic statistical pressure fluctuations can, in principle, lead to corresponding fluctuations in the shape of a protein energy landscape. To examine this, nanosecond molecular dynamics simulations of lysozyme are performed covering a range of temperatures and pressures. The well known dynamical transition with temperature is found to be pressure-independent, indicating that the effective energy barriers separating conformational substates are not significantly influenced by pressure. In contrast, vibrations within substates stiffen with pressure, due to increased curvature of the local harmonic potential in which the atoms vibrate. The application of pressure is also shown to selectively increase the damping of the anharmonic, low-frequency collective modes in the protein, leaving the more local modes relatively unaffected. The critical damping frequency, i.e., the frequency at which energy is most efficiently dissipated, increases linearly with pressure. The results suggest that an invariant description of protein energy landscapes should be subsumed by a fluctuating picture and that this may have repercussions in, for example, mechanisms of energy dissipation accompanying functional, structural, and chemical relaxation

Anti-Herpetic Activity of Callissia fragrans and Simmondsia chinensis Leaf Extracts In Vitro

The antiviral activity of Callissia fragrans and Simnondsia chinensis aquatic and ethanol leaf extracts, as well as purified fractions from these extracts was studied against herpetic viruses in vitro. Ethanol extract of C. fragrans effectively inhibited the infection of Vero cells by HSV-1, HSV-2 in vitro, while its aquatic extract inhibited only VZV. Although S. chinensis leaf extract strongly inhibited all studied viruses, the selectivity index of this extract was very low, due to its high toxicity. However, the majority of its fractions showed low toxicity and higher antiviral activity and therefore very high SI. Strong interactions between virus and extracts were found