Plasma concentrations of free amyloid β cannot predict the development of Alzheimer's disease

INTRODUCTION: Biomarkers that identify individuals at risk of Alzheimer's disease (AD) development would be highly valuable. Plasma concentration of amyloid β (Aβ)-central in the pathogenesis of AD-is a logical candidate, but studies to date have produced conflicting results on its utility. METHODS: Plasma samples from 339 preclinical AD cases (76.4% women, mean age 61.3 years) and 339 age- and sex-matched dementia-free controls, taken an average of 9.4 years before AD diagnosis, were analyzed using Luminex xMAP technology and INNO-BIA plasma Aβ form assays to determine concentrations of free plasma Aβ40 and Aβ42. RESULTS: Plasma concentrations of free Aβ40 and Aβ42 did not differ between preclinical AD cases and dementia-free controls, in the full sample or in subgroups defined according to sex and age group (<60 and ≥ 60 years). The interval between sampling and AD diagnosis did not affect the results. Aβ concentrations did not change in the years preceding AD diagnosis among individuals for whom longitudinal samples were available. DISCUSSION: Plasma concentrations of free Aβ could not predict the development of clinical AD, and Aβ concentrations did not change in the years preceding AD diagnosis in this sample. These results indicate that free plasma Aβ is not a useful biomarker for the identification of individuals at risk of developing clinical AD

The hip fracture incidence curve is shifting to the right: A forecast of the age-quake

Background The number of hip fractures has doubled in the last 30–40 years in many countries. Age-adjusted incidence has been reported to be decreasing in Europe and North America, but is there a decreasing trend in all age groups

Behavioural and psychological symptoms in the older population without dementia - relationship with socio-demographics, health and cognition

<p>Abstract</p> <p>Background</p> <p>Behavioural and psychological symptoms are associated with dementia, but are also present in a significant number of the older population without dementia. Here we explore the distribution of behavioural and psychological symptoms in the population without dementia, and their relationship with domains and severity of health and cognitive impairment.</p> <p>Methods</p> <p>The Medical Research Council Cognitive Function and Ageing Study is a two-phase longitudinal study of ageing representative of the population aged 65 and over of England and Wales. A subsample of 1781 participants without a study diagnosis of dementia was included in this study. Information on symptoms including depression, apathy, anxiety, feelings of persecution, hallucination, agitated behaviour, elation, irritability, sleep problems, wandering, confabulation and misidentification, cognitive function, health related factors and socio-demographic information was extracted from interviews with participants and knowledgeable informants. Participants were classified according to the Mini-Mental State Examination and by criteria for subtypes of mild cognitive impairment (MCI). The prevalence of behavioural and psychological symptoms and associations with cognitive function, health and socio-demographics was examined. Co-occurrence of symptoms was tested using factor analysis.</p> <p>Results</p> <p>Most symptoms were reported more frequently in those with more severe cognitive impairment. Subjective memory complaints were the strongest independent predictor of reported symptoms, and most were reported more often in those classified as having MCI than in those with cognitive impairments that did not meet the MCI criteria. The pattern of co-occurrence of symptoms is similar to that seen in dementia.</p> <p>Conclusions</p> <p>Our results highlight that behavioural and psychological symptoms are prevalent in the cognitively impaired older population, and partly explain the variation observed in previous cohorts of individuals with MCI. Behavioural and psychological symptoms offer a target for intervention and so are an important consideration in the assessment of cognitively impaired older people.</p

Young Adults’ Conceptions of the Sacred in Finland Today

Peer reviewe

HSV presence in brains of individuals without dementia: the TASTY brain series

Herpes simplex virus (HSV) type 1 affects a majority of the population and recent evidence suggests involvement in Alzheimer's disease aetiology. We investigated the prevalence of HSV type 1 and 2 in the Tampere Autopsy Study (TASTY) brain samples using PCR and sero-positivity in plasma, and associations with Alzheimer's disease neuropathology. HSV was shown to be present in human brain tissue in 11/584 (1.9%) of samples in the TASTY cohort, of which six had Alzheimer's disease neuropathological amyloid beta (Aβ) aggregations. Additionally, serological data revealed 86% of serum samples tested were IgG-positive for HSV. In conclusion, we report epidemiological evidence of the presence of HSV in brain tissue free from encephalitis symptoms in a cohort most closely representing the general population (a minimum prevalence of 1.9%). Whereas 6/11 samples with HSV DNA in the brain tissue had Aβ aggregations, most of those with Aβ aggregations did not have HSV present in the brain tissue