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Richards, M.

Publications and source records attributed to Richards, M..

21 records · Page 2Linked to original sources

Delirium symptoms are associated with decline in cognitive function between ages 53 to 69: findings from a British birth cohort study.

INTRODUCTIONFew population studies have investigated whether longitudinal decline after delirium in mid-to-late life might affect specific cognitive domains.\n\nMETHODSParticipants from a birth cohort completing assessments of search speed, verbal memory and the Addenbrookes Cognitive Examination at age 69 were asked about delirium symptoms between ages 60-69. Linear regression models estimated associations between delirium symptoms and cognitive outcomes.\n\nRESULTSPeriod prevalence of delirium between 60 and 69 was 4% (95% CI 3.2%,4.9%). Self-reported symptoms of delirium over the seventh decade were associated with worse scores in the Addenbrookes Cognitive Examination (-1.7 points, 95% CI -3.2, -0.1, p=0.04). In association with delirium symptoms, verbal memory scores were initially lower, with subsequent decline in search speed by age 69. These effects were independent of other Alzheimers risk factors.\n\nDISCUSSIONDelirium symptoms may be common even at relatively younger ages, and their presence may herald cognitive decline, particularly in search speed, over this time period.

epidemiology↗

Apolipoprotein-E (ApoE) ϵ4 and cognitive decline over the adult life course

We tested the association between APOE-{varepsilon}4 and processing speed and memory between ages 43 and 69 in a population-based birth cohort. Analyses of processing speed (using a timed letter search task) and episodic memory (a 15-item word learning test) were conducted at ages 43, 53, 60-64 and 69 years using linear and multivariable regression, adjusting for gender and childhood cognition. Linear mixed models, with random intercepts and slopes, were conducted to test the association between APOE and the rate of decline in these cognitive scores from age 43 to 69. Model fit was assessed with the Bayesian Information Criterion. A cross-sectional association between APOE-{varepsilon}4 and memory scores was detected at age 69 for both heterozygotes and homozygotes ({beta}=-0.68 & {beta}=-1.38 respectively, p=.03) with stronger associations in homozygotes; no associations were observed before this age. Homozygous carriers of APOE-{varepsilon}4 had a faster rate of decline in memory between ages 43 and 69, when compared to noncarriers, after adjusting for gender and childhood cognition ({beta}=-0.05, p=.04). There were no cross-sectional or longitudinal associations between APOE-{varepsilon}4 and processing speed. We conclude that APOE-{varepsilon}4 is associated with a subtly faster rate of memory decline from midlife to early old age; this may be due to effects of APOE-{varepsilon}4 becoming manifest around the latter stage of life. Continuing follow-up will determine what proportion of this increase will become clinically significant.

epidemiology↗

ProbAnnoWeb and ProbAnnoPy: probabilistic annotation and gap-filling of metabolic reconstructions

SummaryGap-filling is a necessary step to produce quality genome-scale metabolic reconstructions capable of flux-balance simulation. Most available gap-filling tools use an organism-agnostic approach, where reactions are selected from a database to fill gaps without consideration of the target organism. Conversely, our likelihood based gap-filling with probabilistic annotations selects candidate reactions based on a likelihood score derived specifically from the target organisms genome. Here, we present two new implementations of probabilistic annotation and likelihood based gap-filling: a web service called ProbAnnoWeb, and a standalone python package called ProbAnnoPy.\n\nAvailability and ImplementationOur tools are available as a web service with no installation needed (ProbAnnoWeb), available at http://probannoweb.systemsbiology.net, and as a local python package implementation (ProbAnnoPy), available for download at http://github.com/PriceLab/probannopy.\n\nContacthttp://Evangelos.Simeonidis@systemsbiology.org; http://Nathan.Price@systemsbiology.org

systems biology↗