72 research outputs found

    Functionalization of 4-Substituted Pyridines for Enantioselective Synthesis

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    Enantioselective synthesis using nitrogen containing heterocycles, such as pyridines, is extremely useful in drug discovery. The prevalence of pyridines in the drug market is well-documented and a mild, enantioselective method to functionalize pyridines would allow faster access to more structurally diverse pyridines, improving efficiency in the search of drug candidates. The Orellana group has developed a strategy for selective allylation of 4-substituted pyridines using mild conditions, which results in broad functional group tolerance. Reported herein are ways to expand the allyl fragment to larger linear and cyclic fragments, and attempts at the development of an enantioselective variant using palladium catalyzed decarboxylative allylation. The pathway for reductive elimination was also discovered through mechanistic experiments which revealed more of this palladium catalyzed decarboxylative allylation mechanism. Furthermore, a new method was investigated for arylation of the pyridylic position using a high-valent copper catalysis

    Dynamic reciprocal relationships between cognitive and functional declines along the Alzheimer's disease continuum in the prospective COGICARE study

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    BACKGROUND: Thoroughly understanding the temporal associations between cognitive and functional dimensions along the dementia process is fundamental to define preventive measures likely to delay the disease's onset. This work aimed to finely describe the trajectories of cognitive and functional declines, and assess their dynamic bidirectional relationships among subjects at different stages of the dementia process. METHODS: We leveraged extensive repeated data of cognition and functional dependency from the French prospective COGICARE study, designed to better characterize the natural history of cognitive and functional declines around dementia diagnosis. Cognition was measured by the Mini-Mental State Examination, the Isaacs Set Test for verbal fluency, the Benton Visual Retention Test for visuo-spatial memory, and Trail Making Test Part B for executive functioning. Functional dependency was measured by basic and instrumental activities of daily living. The study included 102 cognitively normal, 123 mildly cognitively impaired, and 72 dementia cases with a median of 5 repeated visits over up to 57 months. We used a dynamic causal model which addresses the two essential issues in temporal associations assessment: focusing on intra-individual change and accounting for time. RESULTS: Better cognitive abilities were associated with lower subsequent decline of the functional level among the three clinical stages with an intensification over time but no reciprocity of the association whatever the clinical status. CONCLUSION: This work confirms that the progressive functional dependency could be induced by cognitive impairment. Subjects identified as early as possible with clinically significant cognitive impairments could benefit from preventive measures before the deterioration of activities of daily living and the appearance of dementia clinical signs.Modèles statistiques pour la maladie d'Alzheimer et le vieillissementHistoire naturelle du déclin cognitif et du besoin de soins chez le sujet âg

    Mediterranean Diet Adherence and Risk of Depressive Symptomatology in a French Population-Based Cohort of Older Adults

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    Several foods from the Mediterranean Diet (MeDi) have already been characterized as beneficial for depression risk, while studies focusing on adherence to the overall MeDi are lacking among older adults at higher risk of depression. The aim of this study was to assess the association between MeDi adherence and the risk of depressive symptomatology (DS) in an older French cohort followed for 15 years. Participants from the Three-City Bordeaux cohort answered a food frequency questionnaire used to assess their MeDi adherence. The Center for Epidemiologic Studies Depression (CES-D) scale score of 16 or greater and/or use of antidepressant treatment ascertained at each visit defined incident DS. Random-effect logistic regression models were adjusted for potential confounders. Among 1018 participants, aged 75.6 years (SD 4.8 years) on average at baseline, 400 incident cases of DS were identified during the follow-up. Only when restricting the definition of DS to a CES-D score ≥ 16 was a borderline-significant trend towards a benefit of greater adherence to the MeDi with reduced odds of DS found (p-value = 0.053). In this large sample of older French adults, a potential benefit of greater adherence to the MeDi regarding the risk of DS would depend on the definition of DS

    Exposure to ambient air pollution and cognitive decline: Results of the prospective Three-City cohort study

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    BACKGROUND: Growing epidemiological evidence suggests an adverse relationship between exposure to air pollutants and cognitive decline. However, there is still some heterogeneity in the findings, with inconsistent results depending on the pollutant and the cognitive domain considered. We wanted to determine whether air pollution was associated with global and domain-specific cognitive decline. METHODS: This analysis used data from the French Three-City prospective cohort (participants aged 65 and older at recruitment and followed for up to 12 years). A battery of cognitive tests was administered at baseline and every 2 years, to assess global cognition (Mini Mental State Examination, MMSE), visual memory (Benton Visual Retention Test), semantic fluency (Isaacs Set Test) and executive functions (Trail Making Tests A and B). Exposure to fine particulate matter (PM(2.5)), nitrogen dioxide (NO(2)) and black carbon (BC) at the participants' residential address during the 5 years before the baseline visit was estimated with land use regression models. Linear mixed models and latent process mixed models were used to assess the association of each pollutant with global and domain-specific cognitive decline. RESULTS: The participants' (n = 6380) median age was 73.4 years (IQR: 8.0), and 61.5% were women. At baseline, the median MMSE score was 28 (IQR: 3). Global cognition decline, assessed with the MMSE, was slightly accelerated among participants with higher PM(2.5) exposure: one IQR increment in PM(2.5) (1.5 µg/m(3)) was associated with accelerated decline (β: -0.0060 [-0.0112; -0.0007] standard unit per year). Other associations were inconsistent in direction, and of small magnitude. CONCLUSION: In this large population-based cohort, higher PM(2.5) exposure was associated with accelerated global cognition decline. We did not detect any significant association for the specific cognitive domains or the other pollutants. Evidence concerning PM(2.5) effects on cognition is growing, but more research is needed on other ambient air pollutants

    Determinants of cognitive performance and decline in 20 diverse ethno-regional groups: A COSMIC collaboration cohort study.

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    BACKGROUND: With no effective treatments for cognitive decline or dementia, improving the evidence base for modifiable risk factors is a research priority. This study investigated associations between risk factors and late-life cognitive decline on a global scale, including comparisons between ethno-regional groups. METHODS AND FINDINGS: We harmonized longitudinal data from 20 population-based cohorts from 15 countries over 5 continents, including 48,522 individuals (58.4% women) aged 54-105 (mean = 72.7) years and without dementia at baseline. Studies had 2-15 years of follow-up. The risk factors investigated were age, sex, education, alcohol consumption, anxiety, apolipoprotein E ε4 allele (APOE*4) status, atrial fibrillation, blood pressure and pulse pressure, body mass index, cardiovascular disease, depression, diabetes, self-rated health, high cholesterol, hypertension, peripheral vascular disease, physical activity, smoking, and history of stroke. Associations with risk factors were determined for a global cognitive composite outcome (memory, language, processing speed, and executive functioning tests) and Mini-Mental State Examination score. Individual participant data meta-analyses of multivariable linear mixed model results pooled across cohorts revealed that for at least 1 cognitive outcome, age (B = -0.1, SE = 0.01), APOE*4 carriage (B = -0.31, SE = 0.11), depression (B = -0.11, SE = 0.06), diabetes (B = -0.23, SE = 0.10), current smoking (B = -0.20, SE = 0.08), and history of stroke (B = -0.22, SE = 0.09) were independently associated with poorer cognitive performance (p < 0.05 for all), and higher levels of education (B = 0.12, SE = 0.02) and vigorous physical activity (B = 0.17, SE = 0.06) were associated with better performance (p < 0.01 for both). Age (B = -0.07, SE = 0.01), APOE*4 carriage (B = -0.41, SE = 0.18), and diabetes (B = -0.18, SE = 0.10) were independently associated with faster cognitive decline (p < 0.05 for all). Different effects between Asian people and white people included stronger associations for Asian people between ever smoking and poorer cognition (group by risk factor interaction: B = -0.24, SE = 0.12), and between diabetes and cognitive decline (B = -0.66, SE = 0.27; p < 0.05 for both). Limitations of our study include a loss or distortion of risk factor data with harmonization, and not investigating factors at midlife. CONCLUSIONS: These results suggest that education, smoking, physical activity, diabetes, and stroke are all modifiable factors associated with cognitive decline. If these factors are determined to be causal, controlling them could minimize worldwide levels of cognitive decline. However, any global prevention strategy may need to consider ethno-regional differences

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Comparaisons des méthodes d'analyse des données binaires ou ordinales corrélées (Application à l'étude longitudinale de l'incapacité des personnes agées)

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    LE KREMLIN-B.- PARIS 11-BU Méd (940432101) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

    Aging Ment Health

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    To examine the relationship between hearing loss and depression in older adults longitudinally. This paper uses a dimensional approach to conceptualising depression, with the aim of further enhancing understanding of this relationship. 8344 community-dwelling adults aged 65 years and above enrolled in the Three-City prospective cohort study were included. Relationships between baseline self-reported hearing loss (HL) with the trajectory of different dimensions of depression symptoms over 12 years were examined using linear mixed models. Depression dimensions were determined using the four-factor structure of the Centre for Epidemiology Studies-Depression Scale (CESD): depressed affect, positive affect, somatic symptoms and interpersonal problems. HL was associated with somatic symptoms of depression both at baseline ( = .07,  = .04) and over 12 years ( = .01,  = .04). HL was associated with poorer depressed affect and interpersonal problems at baseline ( = .05,  = .001,  = .35,  < .001; respectively), but not over follow-up. HL was associated with poorer positive affect symptoms over time ( = -.01,  = .01). HL had varied relationships with different dimensions of depression symptoms, and there were different patterns of adjustment for the dimensions. HL was primarily associated with somatic symptoms, suggesting that shared disease processes might partly underlie the relationship between HL and depression. Targeted assessment and treatment of somatic and positive affect symptoms in older adults with HL might facilitate better wellbeing in this population.Ears, Eyes and Mind: The ‘SENSE-Cog Project’ to improve mental well-being for elderly Europeans with sensory impairmen

    Trajectories of sleep duration and timing before dementia: a 14-year follow-up study

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    BACKGROUND: given the complex relationship between sleep and neurodegenerative processes, it is important to examine whether changes in sleep patterns occur prior or close to dementia onset. OBJECTIVE: to examine the relationship between sleep parameters and dementia incidence and, to characterize trajectories of sleep patterns before dementia diagnosis. DESIGN: a 14-year longitudinal study including a nested case-control study. SETTING: the French Three-City Study. SUBJECTS: overall, 1,749 cognitively healthy participants (>/=65 years) for the longitudinal study and, 182 incident dementia cases and 719 controls matched by sex, age and educational level for the case-control study. METHODS: dementia cases were assessed at each visit and self-reported sleep parameters at baseline, 2, 8, 10, 12 and 14 years. Cox models were used to estimate the risk of dementia associated with baseline sleep parameters (sleep duration, time in bed (TIB), sleep timing, sleepiness and insomnia). Latent-process mixed models were performed to compare sleep trajectories according to the case-control status. RESULTS: long baseline nighttime and 24-h sleep durations (>/=9 h) as well as being persistent or becoming long sleepers during follow-up were associated with dementia incidence. Trajectories of sleep durations and TIB showed faster increases in cases compared with controls up to 12 years before dementia. The mean differences [95%CI] for 24-h sleep duration between cases and controls were: 0.27 h [0.01;0.52], 0.34 [0.09;0.58] and 0.67 [0.44;0.90] at -12, -8 and -2 years, respectively. Bedtime trajectories showed an earlier bedtime in cases up to -8 years. CONCLUSION: long sleep duration and earlier bedtime may impact dementia incidence
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