567 research outputs found

    Remote Assisted Task Management for ISOBUS Equipped Tractor-Implement Combination

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    Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 9 (2007): Remote Assisted Task Management for ISOBUS Equipped Tractor-Implement Combination. Manuscript ATOE 07 011. Vol. IX. July, 2007

    Alzheimer's disease

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    In this Seminar, we highlight the main developments in the field of Alzheimer's disease. The most recent data indicate that, by 2050, the prevalence of dementia will double in Europe and triple worldwide, and that estimate is 3 times higher when based on a biological (rather than clinical) definition of Alzheimer's disease. The earliest phase of Alzheimer's disease (cellular phase) happens in parallel with accumulating amyloid β, inducing the spread of tau pathology. The risk of Alzheimer's disease is 60-80% dependent on heritable factors, with more than 40 Alzheimer's disease-associated genetic risk loci already identified, of which the APOE alleles have the strongest association with the disease. Novel biomarkers include PET scans and plasma assays for amyloid β and phosphorylated tau, which show great promise for clinical and research use. Multidomain lifestyle-based prevention trials suggest cognitive benefits in participants with increased risk of dementia. Lifestyle factors do not directly affect Alzheimer's disease pathology, but can still contribute to a positive outcome in individuals with Alzheimer's disease. Promising pharmacological treatments are poised at advanced stages of clinical trials and include anti-amyloid β, anti-tau, and anti-inflammatory strategies

    Insulin levels are decreased in the cerebrospinal fluid of women with prodomal Alzheimer's disease

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    Previous studies have failed to reach consensus on insulin levels in cerebrospinal fluid of Alzheimer's disease (AD) patients and on its relation to pathological features. We performed a new analysis in patients at different stages of AD, and investigated the relationship of insulin levels with biochemical disease markers and with cognitive score. We included 99 patients from our Memory Clinic (Karolinska University Hospital, Sweden), including: 27 patients with mild AD, 13 that progressed from mild cognitive impairment (MCI) to AD in two years time, 26 with MCI stable after two years, and 33 with subjective cognitive impairment. Insulin was significantly decreased in the cerebrospinal fluid of both women and men with mild AD. Insulin deficits were seen in women belonging to both MCI groups, suggesting that this occurs earlier than in men. Insulin was positively associated with amyloid-β 1-42 (Aβ1-42) levels and cognitive score. Furthermore, total-tau/(Aβ1-42*insulin) ratio showed strikingly better sensitivity and specificity than the total-tau/Aβ1-42 ratio for early AD diagnosis in women

    Profiling of plasma biomarkers in the context of memory assessment in a tertiary memory clinic

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    Plasma biomarkers have shown promising performance in research cohorts in discriminating between different stages of Alzheimer's disease (AD). Studies in clinical populations are necessary to provide insights on the clinical utility of plasma biomarkers before their implementation in real-world settings. Here we investigated plasma biomarkers (glial fibrillary acidic protein (GFAP), tau phosphorylated at 181 and 231 (pTau181, pTau231), amyloid β (Aβ) 42/40 ratio, neurofilament light) in 126 patients (age = 65 ± 8) who were admitted to the Clinic for Cognitive Disorders, at Karolinska University Hospital. After extensive clinical assessment (including CSF analysis), patients were classified as: mild cognitive impairment (MCI) (n = 75), AD (n = 25), non-AD dementia (n = 16), no dementia (n = 9). To refine the diagnosis, patients were examined with [18F]flutemetamol PET (Aβ-PET). Aβ-PET images were visually rated for positivity/negativity and quantified in Centiloid. Accordingly, 68 Aβ+ and 54 Aβ- patients were identified. Plasma biomarkers were measured using single molecule arrays (SIMOA). Receiver-operated curve (ROC) analyses were performed to detect Aβ-PET+ using the different biomarkers. In the whole cohort, the Aβ-PET centiloid values correlated positively with plasma GFAP, pTau231, pTau181, and negatively with Aβ42/40 ratio. While in the whole MCI group, only GFAP was associated with Aβ PET centiloid. In ROC analyses, among the standalone biomarkers, GFAP showed the highest area under the curve discriminating Aβ+ and Aβ- compared to other plasma biomarkers. The combination of plasma biomarkers via regression was the most predictive of Aβ-PET, especially in the MCI group (prior to PET, n = 75) (sensitivity = 100%, specificity = 82%, negative predictive value = 100%). In our cohort of memory clinic patients (mainly MCI), the combination of plasma biomarkers was sensitive in ruling out Aβ-PET negative individuals, thus suggesting a potential role as rule-out tool in clinical practice

    Association Between Cognition, Health Related Quality of Life, and Costs in a Population at Risk for Cognitive Decline

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    Background: The association between health-related quality of life (HRQoL) and care costs in people at risk for cognitive decline is not well understood. Studying this association could reveal the potential benefits of increasing HRQoL and reducing care costs by improving cognition. Objective: In this exploratory data analysis we investigated the association between cognition, HRQoL utilities and costs in a well-functioning population at risk for cognitive decline. Methods: An exploratory data analysis was conducted using longitudinal 2-year data from the FINGER study (n= 1,120). A change score analysis was applied using HRQoL utilities and total medical care costs as outcome. HRQoL utilities were derived from the Short Form Health Survey-36 (SF-36). Total care costs comprised visits to a general practitioner, medical specialist, nurse, and days at hospital. Analyses were adjusted for activities of daily living (ADL) and depressive symptoms. Results: Although univariable analysis showed an association between cognition and HRQoL utilities, multivariable analysis showed no association between cognition, HRQoL utilities and total care costs. A one-unit increase in ADL limitations was associated with a -0.006 (p Conclusion: The level of cognition in people at-risk for cognitive decline does not seem to be associated with HRQoL utilities. Future research should examine the level at which cognitive decline starts to affect HRQoL and care costs. Ideally, this would be done by means of cross-validation in populations with various stages of cognitive functioning and decline.Peer reviewe

    Blood β-synuclein is related to amyloid PET positivity in memory clinic patients

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    INTRODUCTION: β-synuclein is an emerging blood biomarker to study synaptic degeneration in Alzheimer´s disease (AD), but its relation to amyloid-β (Αβ) pathology is unclear. METHODS: We investigated the association of plasma β-synuclein levels with [18F] flutemetamol positron emission tomography (PET) in patients with AD dementia (n = 51), mild cognitive impairment (MCI-Aβ+ n = 18, MCI- Aβ- n = 30), non-AD dementias (n = 22), and non-demented controls (n = 5). RESULTS: Plasma β-synuclein levels were higher in Aβ+ (AD dementia, MCI-Aβ+) than in Aβ- subjects (non-AD dementias, MCI-Aβ-) with good discrimination of Aβ+ from Aβ- subjects and prediction of Aβ status in MCI individuals. A positive correlation between plasma β-synuclein and Aβ PET was observed in multiple cortical regions across all lobes. DISCUSSION: Plasma β-synuclein demonstrated discriminative properties for Aβ PET positive and negative subjects. Our data underline that β-synuclein is not a direct marker of Aβ pathology and suggest different longitudinal dynamics of synaptic degeneration versus amyloid deposition across the AD continuum. HIGHLIGHTS: Blood and CSF β-synuclein levels are higher in Aβ+ than in Aβ- subjects. Blood β-synuclein level correlates with amyloid PET positivity in multiple regions. Blood β-synuclein predicts Aβ status in MCI individuals

    The Karolinska NeuroCOVID study protocol: Neurocognitive impairment, biomarkers and advanced imaging in critical care survivors

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    Background: This is the study plan of the Karolinska NeuroCOVID study, a study of neurocognitive impairment after severe COVID-19, relating post-intensive care unit (ICU) cognitive and neurological deficits to biofluid markers and MRI. The COVID-19 pandemic has posed enormous health challenges to individuals and health-care systems worldwide. An emerging feature of severe COVID-19 is that of temporary and extended neurocognitive impairment, exhibiting a myriad of symptoms and signs. The causes of this symptomatology have not yet been fully elucidated. Methods: In this study, we aim to investigate patients treated for severe COVID-19 in the ICU, as to describe and relate serum-, plasma- and cerebrospinal fluid-borne molecular and cellular biomarkers of immune activity, coagulopathy, cerebral damage, neuronal inflammation, and degeneration, to the temporal development of structural and functional changes within the brain as evident by serial MRI and extensive cognitive assessments at 3–12 months after ICU discharge. Results: To date, we have performed 51 3-month follow-up MRIs in the ICU survivors. Of these, two patients (~4%) have had incidental findings on brain MRI findings requiring activation of the Incidental Findings Management Plan. Furthermore, the neuropsychological and neurological examinations have so far revealed varying and mixed patterns. Several patients expressed cognitive and/or mental concerns and fatigue, complaints closely related to brain fog. Conclusion: The study goal is to gain a better understanding of the pathological mechanisms and neurological consequences of this new disease, with a special emphasis on neurodegenerative and neuroinflammatory processes, in order to identify targets of intervention and rehabilitation

    Health-related quality of life in a multidomain intervention trial to prevent cognitive decline (FINGER)

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    Introduction: The Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) successfully demonstrated that multidomain lifestyle intervention can improve or maintain cognitive functioning in at-risk individuals. Health-related quality of life (HRQoL) was a secondary endpoint. Methods: The intervention (n = 631) aimed at healthy diet, increased physical activity, cognitive training, and vascular risk management. The control group (n = 629) was given general health advice. HRQoL was assessed at baseline, 12, and 24 months using validated RAND-36 (SF-36) instrument with 8 scales. Results: During the 2-year intervention period, mean scores in all scales decreased in the control group, but increased in the intervention group for vitality (12 months), social function (12 months), and especially general health at both 12 and 24 months. There was a statistically significant beneficial effect of intervention on the change in general health and physical function at 12 and 24 months. Conclusion: Multidomain lifestyle intervention improved also important dimensions of HRQoL. (C) 2017 Elsevier Masson SAS and European Union Geriatric Medicine Society. All rights reserved.Peer reviewe
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