347 research outputs found

    Cardiac imaging to detect coronary artery disease in athletes aged 35 years and older. A scoping review.

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    Sudden cardiac death (SCD) is a devastating event in athletes. Screening efforts that were first directed at athletes younger than 35 years, are now focusing on the rapidly growing group of older sportspersons. Athletes aged ≥35 years have a 10-fold increased risk of exercise-related cardiac arrest, mostly due to coronary artery disease (CAD). Although cardiac imaging is pivotal in identifying CAD, the role of imaging modalities in screening asymptomatic older sportspersons remains unclear. We performed a scoping review to identify the role of cardiac imaging to detect CAD in older sportspersons and to identify gaps in the existing literature. We searched Medline, Embase and the Cochrane library for studies reporting data on cardiac imaging of CAD in sportspersons ≥35 years. The systematic search yielded 1737 articles and 14 were included in this scoping review. Imaging modalities included 2 echocardiography, 1 unenhanced Computed Tomography (CT) for coronary artery calcium scoring (CACS), 3 CACS and contrast-enhanced CT angiography (CCTA), 2 CACS and Cardiac Magnetic Resonance (CMR), 1 CCTA with CMR and echocardiography, 2 CCTA, 2 CMR, and 1 myocardial perfusion imaging article. The low number of relevant articles and the selection bias introduced by studying specific groups, like veteran marathon runners, indicate the need for future research. Cardiac CT (CACS and CCTA) probably has the highest potential for pre-participation screening, with high diagnostic value to detect CAD and low radiation dose. However, currently there is insufficient evidence for incorporating routine cardiac imaging in the pre-participation screening of asymptomatic sportspersons over 35 years

    Increased efficiency of direct nanoimprinting on planar and curved bulk titanium through surface modification

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    In this work the direct transfer of nanopatterns into titanium is demonstrated. The nanofeatures are imprinted at room temperature using diamond stamps in a single step. We also show that the imprint properties of the titanium surface can be altered by anodisation yielding a significant reduction in the required imprint force for pattern transfer. The anodisation process is also utilised for curved titanium surfaces where a reduced imprint force is preferable to avoid sample deformation and damage. We finally demonstrate that our process can be applied directly to titanium rods

    Galacto-oligosaccharides alleviate lung inflammation by inhibiting NLRP3 inflammasome activation in vivo and in vitro

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    Introduction: The lack of effective anti-inflammatory therapies for pneumonia represents a challenge for identifying new alternatives. Non-digestible galacto-oligosaccharides (GOS) are attractive candidates due to their anti-inflammatory and immunomodulatory effects both locally and systemically. Objectives: The anti-inflammatory properties of GOS were investigated in calves with lung infections and in calf primary bronchial epithelial cells (PBECs) and human lung epithelial cells (A549). To delineate the mechanism, the potential capacity of GOS to inhibit the NLR family pyrin domain containing 3 (NLRP3) inflammasome has been investigated. Methods: GOS were administrated orally to calves with naturally occurring lung infections during early life or used as pretreatments in cell cultures exposed to M. haemolytica, lipopolysaccharides (LPS), leukotoxin or ATP. The cell composition, cytokine/chemokine concentrations, and M. haemolytica-LPS lgG levels in broncho-alveolar lavage fluid (BALF) and blood were investigated, while the M. haemolytica positivity in BALF and bronchial mucosa was detected in vivo. Key markers of NLRP3 inflammasome activation were measured in vivo and in vitro. Results: GOS reduced M. haemolytica positivity and M. haemolytica-LPS lgG levels in calves with lung infections. Regulation of immune function and suppression of inflammatory response by GOS is related to the inhibition of NLRP3 inflammasome as observed in bronchial mucosal tissue of infected calves. The M. haemolytica-induced IL-1β production in PBECs was lowered by GOS, which was associated with NLRP3 inflammasome inhibition caused by the decreased reactive oxygen species and ATP production. GOS inhibited leukotoxin-induced ATP production in PBECs. The LPS- and ATP-induced NLRP3 inflammasome activation in PBECs and A549 cells was suppressed by GOS. Conclusion: GOS exert anti-inflammatory properties by inhibiting the NLRP3 inflammasome activation in vitro and in vivo, suggesting a potential role for GOS in the prevention of lung infections

    Exercise Volume Versus Intensity and the Progression of Coronary Atherosclerosis in Middle-Aged and Older Athletes: Findings From the MARC-2 Study.

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    BACKGROUND: Physical activity and exercise training are associated with a lower risk for coronary events. However, cross-sectional studies in middle-aged and older male athletes revealed increased coronary artery calcification (CAC) and atherosclerotic plaques, which were related to the amount and intensity of lifelong exercise. We examined the longitudinal relationship between exercise training characteristics and coronary atherosclerosis. METHODS: Middle-aged and older men from the MARC-1 (Measuring Athlete's Risk of Cardiovascular Events 1) study were invited for follow-up in MARC-2 (Measuring Athlete's Risk of Cardiovascular Events 2) study. The prevalence and severity of CAC and plaques were determined by coronary computed tomography angiography. The volume (metabolic equivalent of task [MET] hours/week) and intensity (moderate [3 to 6 MET hours/week]; vigorous [6 to 9 MET hours/week]; and very vigorous [≥9 MET hours/week]) of exercise training were quantified during follow-up. Linear and logistic regression analyses were performed to determine the association between exercise volume/intensity and markers of coronary atherosclerosis. RESULTS: We included 289 (age, 54 [50 to 60] years [median (Q1 to Q3)]) of the original 318 MARC-1 participants with a follow-up of 6.3±0.5 years (mean±SD). Participants exercised for 41 (25 to 57) MET hours/week during follow-up, of which 0% (0 to 19%) was at moderate intensity, 44% (0 to 84%) was at vigorous intensity, and 34% (0 to 80%) was at very vigorous intensity. Prevalence of CAC and the median CAC score increased from 52% to 71% and 1 (0 to 32) to 31 (0 to 132), respectively. Exercise volume during follow-up was not associated with changes in CAC or plaque. Vigorous intensity exercise (per 10% increase) was associated with a lesser increase in CAC score (β, -0.05 [-0.09 to -0.01]; P=0.02), whereas very vigorous intensity exercise was associated with a greater increase in CAC score (β, 0.05 [0.01 to 0.09] per 10%; P=0.01). Very vigorous exercise was also associated with increased odds of dichotomized plaque progression (adjusted odds ratio [aOR], 1.09 [1.01 to 1.18] per 10% vs 2.04 [0.93 to 4.15] for highest vs lowest very vigorous intensity tertiles, respectively), and specifically with increased calcified plaques (aOR, 1.07 [1.00 to 1.15] per 10% vs 2.09 [1.09 to 4.00] for highest vs lowest tertile, respectively). CONCLUSIONS: Exercise intensity but not volume was associated with progression of coronary atherosclerosis during 6-year follow-up. It is intriguing that very vigorous intensity exercise was associated with greater CAC and calcified plaque progression, whereas vigorous intensity exercise was associated with less CAC progression

    Cigarette smoke induces β2-integrin-dependent neutrophil migration across human endothelium

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    <p>Abstract</p> <p>Background</p> <p>Cigarette smoking induces peripheral inflammatory responses in all smokers and is the major risk factor for neutrophilic lung disease such as chronic obstructive pulmonary disease. The aim of this study was to investigate the effect of cigarette smoke on neutrophil migration and on β<sub>2</sub>-integrin activation and function in neutrophilic transmigration through endothelium.</p> <p>Methods and results</p> <p>Utilizing freshly isolated human PMNs, the effect of cigarette smoke on migration and β<sub>2</sub>-integrin activation and function in neutrophilic transmigration was studied. In this report, we demonstrated that cigarette smoke extract (CSE) dose dependently induced migration of neutrophils <it>in vitro</it>. Moreover, CSE promoted neutrophil adherence to fibrinogen. Using functional blocking antibodies against CD11b and CD18, it was demonstrated that Mac-1 (CD11b/CD18) is responsible for the cigarette smoke-induced firm adhesion of neutrophils to fibrinogen. Furthermore, neutrophils transmigrated through endothelium by cigarette smoke due to the activation of β<sub>2</sub>-integrins, since pre-incubation of neutrophils with functional blocking antibodies against CD11b and CD18 attenuated this transmigration.</p> <p>Conclusion</p> <p>This is the first study to describe that cigarette smoke extract induces a direct migratory effect on neutrophils and that CSE is an activator of β<sub>2</sub>-integrins on the cell surface. Blocking this activation of β<sub>2</sub>-integrins might be an important target in cigarette smoke induced neutrophilic diseases.</p

    White matter microstructure disruption in early stage amyloid pathology.

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    Introduction: Amyloid beta (Aβ) accumulation is the first pathological hallmark of Alzheimer's disease (AD), and it is associated with altered white matter (WM) microstructure. We aimed to investigate this relationship at a regional level in a cognitively unimpaired cohort. Methods: We included 179 individuals from the European Medical Information Framework for AD (EMIF‐AD) preclinAD study, who underwent diffusion magnetic resonance (MR) to determine tract‐level fractional anisotropy (FA); mean, radial, and axial diffusivity (MD/RD/AxD); and dynamic [18F]flutemetamol) positron emission tomography (PET) imaging to assess amyloid burden. Results: Regression analyses showed a non‐linear relationship between regional amyloid burden and WM microstructure. Low amyloid burden was associated with increased FA and decreased MD/RD/AxD, followed by decreased FA and increased MD/RD/AxD upon higher amyloid burden. The strongest association was observed between amyloid burden in the precuneus and body of the corpus callosum (CC) FA and diffusivity (MD/RD) measures. In addition, amyloid burden in the anterior cingulate cortex strongly related to AxD and RD measures in the genu CC. Discussion: Early amyloid deposition is associated with changes in WM microstructure. The non‐linear relationship might reflect multiple stages of axonal damage

    Amyloid-driven disruption of default mode network connectivity in cognitively healthy individuals

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    Cortical accumulation of amyloid beta is one of the first events of Alzheimer's disease pathophysiology, and has been suggested to follow a consistent spatiotemporal ordering, starting in the posterior cingulate cortex, precuneus and medio-orbitofrontal cortex. These regions overlap with those of the default mode network, a brain network also involved in memory functions. Aberrant default mode network functional connectivity and higher network sparsity have been reported in prodromal and clinical Alzheimer's disease. We investigated the association between amyloid burden and default mode network connectivity in the preclinical stage of Alzheimer's disease and its association with longitudinal memory decline. We included 173 participants, in which amyloid burden was assessed both in CSF by the amyloid beta 42/40 ratio, capturing the soluble part of amyloid pathology, and in dynamic PET scans calculating the non-displaceable binding potential in early-stage regions. The default mode network was identified with resting-state functional MRI. Then, we calculated functional connectivity in the default mode network, derived from independent component analysis, and eigenvector centrality, a graph measure recursively defining important nodes on the base of their connection with other important nodes. Memory was tested at baseline, 2- and 4-year follow-up. We demonstrated that higher amyloid burden as measured by both CSF amyloid beta 42/40 ratio and non-displaceable binding potential in the posterior cingulate cortex was associated with lower functional connectivity in the default mode network. The association between amyloid burden (CSF and non-displaceable binding potential in the posterior cingulate cortex) and aberrant default mode network connectivity was confirmed at the voxel level with both functional connectivity and eigenvector centrality measures, and it was driven by voxel clusters localized in the precuneus, cingulate, angular and left middle temporal gyri. Moreover, we demonstrated that functional connectivity in the default mode network predicts longitudinal memory decline synergistically with regional amyloid burden, as measured by non-displaceable binding potential in the posterior cingulate cortex. Taken together, these results suggest that early amyloid beta deposition is associated with aberrant default mode network connectivity in cognitively healthy individuals and that default mode network connectivity markers can be used to identify subjects at risk of memory decline

    Performance of a [18F]Flortaucipir PET Visual Read Method Across the Alzheimer Disease Continuum and in Dementia With Lewy Bodies

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    Background and Objectives: Recently, the US Food and Drug Administration approved the tau-binding radiotracer [18F]flortaucipir and an accompanying visual read method to support the diagnostic process in cognitively impaired patients assessed for Alzheimer disease (AD). Studies evaluating this visual read method are limited. In this study, we evaluated the performance of the visual read method in participants along the AD continuum and dementia with Lewy bodies (DLB) by determining its reliability, accordance with semiquantitative analyses, and associations with clinically relevant variables. // Methods: We included participants who underwent tau-PET at Amsterdam University Medical Center. A subset underwent follow-up tau-PET. Two trained nuclear medicine physicians visually assessed all scans. Inter-reader agreement was calculated using Cohen κ. To examine the concordance of visual read tau positivity with semiquantification, we defined standardized uptake value ratio (SUVr) positivity using different threshold approaches. To evaluate the prognostic value of tau-PET visual read, we performed linear mixed models with longitudinal Mini-Mental State Examination (MMSE). // Results: We included 263 participants (mean age 68.5 years, 45.6% female), including 147 cognitively unimpaired (CU) participants, 97 amyloid-positive participants with mild cognitive impairment or AD dementia (AD), and 19 participants with DLB. The visual read inter-reader agreement was excellent (κ = 0.95, CI 0.91–0.99). None of the amyloid-negative CU participants (0/92 [0%]) and 1 amyloid-negative participant with DLB (1/12 [8.3%]) were tau-positive. Among amyloid-positive participants, 13 CU participants (13/52 [25.0%]), 85 with AD (85/97 [87.6%]), and 3 with DLB (3/7 [42.9%]) were tau-positive. Two-year follow-up visual read status was identical to baseline. Tau-PET visual read corresponded strongly to SUVr status, with up to 90.4% concordance. Visual read tau positivity was associated with a decline on the MMSE in CU participants (β = −0.52, CI −0.74 to −0.30, p < 0.001) and participants with AD (β = −0.30, CI −0.58 to −0.02, p = 0.04). // Discussion: The excellent inter-reader agreement, strong correspondence with SUVr, and longitudinal stability indicate that the visual read method is reliable and robust, supporting clinical application. Furthermore, visual read tau positivity was associated with prospective cognitive decline, highlighting its additional prognostic potential. Future studies in unselected cohorts are needed for a better generalizability to the clinical population. // Classification of Evidence: This study provides Class II evidence that [18F]flortaucipir visual read accurately distinguishes patients with low tau-tracer binding from those with high tau-tracer binding and is associated with amyloid positivity and cognitive decline. // Glossary: Aβ=β-amyloid; AD=Alzheimer disease; CU=cognitively unimpaired; DLB=dementia with Lewy bodies; US FDA=US Food and Drug Administration; GMM=Gaussian mixture model; LMM=linear mixed model; MCI=mild cognitive impairment; MMSE=Mini-Mental State Examination; OR=odds ratio; ROI=region of interest; SCD=subjective cognitive decline; SUVr=standardized uptake value ratio
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