Summary Background Three subtypes of Alzheimer's disease (AD) have been pathologically defined on the basis of the distribution of neurofibrillary tangles: typical AD, hippocampal-sparing AD, and ...limbic-predominant AD. Compared with typical AD, hippocampal-sparing AD has more neurofibrillary tangles in the cortex and fewer in the hippocampus, whereas the opposite pattern is seen in limbic-predominant AD. We aimed to determine whether MRI patterns of atrophy differ between these subtypes and whether structural neuroimaging could be a useful predictor of pathological subtype at autopsy. Methods We identified patients who had been followed up in the Mayo Clinic Alzheimer's Disease Research Center (Rochester, MN, USA) or in the Alzheimer's Disease Patient Registry (Rochester, MN, USA) between 1992 and 2005. To be eligible for inclusion, participants had to have had dementia, AD pathology at autopsy (Braak stage ≥IV and intermediate to high probability of AD), and an ante-mortem MRI. Cases were assigned to one of three pathological subtypes—hippocampal-sparing, limbic-predominant, and typical AD—on the basis of neurofibrillary tangle counts in hippocampus and cortex and ratio of hippocampal to cortical burden, without reference to neuronal loss. Voxel-based morphometry and atlas-based parcellation were used to compare patterns of grey matter loss between groups and with age-matched control individuals. Neuroimaging was obtained at the time of first presentation. To summarise pair-wise group differences, we report the area under the receiver operator characteristic curve (AUROC). Findings Of 177 eligible patients, 125 (71%) were classified as having typical AD, 33 (19%) as having limbic-predominant AD, and 19 (11%) as having hippocampal-sparing AD. Most patients with typical (98 78%) and limbic-predominant AD (31 94%) initially presented with an amnestic syndrome, but fewer patients with hippocampal-sparing AD (eight 42%) did. The most severe medial temporal atrophy was recorded in patients with limbic-predominant AD, followed by those with typical disease, and then those with hippocampal-sparing AD. Conversely, the most severe cortical atrophy was noted in patients with hippocampal-sparing AD, followed by those with typical disease, and then limbic-predominant AD. The ratio of hippocampal to cortical volumes allowed the best discrimination between subtypes (p<0·0001; three-way AUROC 0·52 95% CI 0·47–0·52; ratio of AUROC to chance classification 3·1 2·8–3·1). Patients with typical AD and non-amnesic initial presentation had a significantly higher ratio of hippocampal to cortical volumes (median 0·045 IQR 0·035–0·056) than did those with an amnesic presentation (0·041 0·031–0·057; p=0·001). Interpretation Patterns of atrophy on MRI differ across the pathological subtypes of AD. MRI regional volumetric analysis can reliably track the distribution of neurofibrillary tangle pathology and can predict pathological subtype of AD at autopsy. Funding US National Institutes of Health (National Institute on Aging).
The hexanucleotide repeat expansion GGGGCC (G
4
C
2
)
n
in the
C9orf72
gene is the most common genetic abnormality associated with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia ...(FTD). Recent findings suggest that dysfunction of nuclear-cytoplasmic trafficking could affect the transport of RNA binding proteins in C9orf72 ALS/FTD. Here, we provide evidence that the RNA editing enzyme adenosine deaminase acting on RNA 2 (ADAR2) is mislocalized in C9orf72 repeat expansion mediated ALS/FTD. ADAR2 is responsible for adenosine (A) to inosine (I) editing of double-stranded RNA, and its function has been shown to be essential for survival. Here we show the mislocalization of ADAR2 in human induced pluripotent stem cell-derived motor neurons (hiPSC-MNs) from C9orf72 patients, in mice expressing (G
4
C
2
)
149
, and in C9orf72 ALS/FTD patient postmortem tissue. As a consequence of this mislocalization we observe alterations in RNA editing in our model systems and across multiple brain regions. Analysis of editing at 408,580 known RNA editing sites indicates that there are vast RNA A to I editing aberrations in C9orf72-mediated ALS/FTD. These RNA editing aberrations are found in many cellular pathways, such as the ALS pathway and the crucial EIF2 signaling pathway. Our findings suggest that the mislocalization of ADAR2 in C9orf72 mediated ALS/FTD is responsible for the alteration of RNA processing events that may impact vast cellular functions, including the integrated stress response (ISR) and protein translation.
Critical care, like many healthcare areas, is under a dual assault from significantly increasing demographic and economic pressures. Intensive care unit (ICU) patients are highly variable in response ...to treatment, and increasingly aging populations mean ICUs are under increasing demand and their cohorts are increasingly ill. Equally, patient expectations are growing, while the economic ability to deliver care to all is declining. Better, more productive care is thus the big challenge. One means to that end is personalised care designed to manage the significant inter- and intra-patient variability that makes the ICU patient difficult. Thus, moving from current "one size fits all" protocolised care to adaptive, model-based "one method fits all" personalised care could deliver the required step change in the quality, and simultaneously the productivity and cost, of care. Computer models of human physiology are a unique tool to personalise care, as they can couple clinical data with mathematical methods to create subject-specific models and virtual patients to design new, personalised and more optimal protocols, as well as to guide care in real-time. They rely on identifying time varying patient-specific parameters in the model that capture inter- and intra-patient variability, the difference between patients and the evolution of patient condition. Properly validated, virtual patients represent the real patients, and can be used in silico to test different protocols or interventions, or in real-time to guide care. Hence, the underlying models and methods create the foundation for next generation care, as well as a tool for safely and rapidly developing personalised treatment protocols over large virtual cohorts using virtual trials. This review examines the models and methods used to create virtual patients. Specifically, it presents the models types and structures used and the data required. It then covers how to validate the resulting virtual patients and trials, and how these virtual trials can help design and optimise clinical trial. Links between these models and higher order, more complex physiome models are also discussed. In each section, it explores the progress reported up to date, especially on core ICU therapies in glycemic, circulatory and mechanical ventilation management, where high cost and frequency of occurrence provide a significant opportunity for model-based methods to have measurable clinical and economic impact. The outcomes are readily generalised to other areas of medical care.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Hyperglycaemia is associated with adverse outcomes in the intensive care unit, and initial studies suggested outcome benefits of glycaemic control (GC). However, subsequent studies often failed to ...replicate these results, and they were often unable to achieve consistent, safe control, raising questions about the benefit or harm of GC as well as the nature of the association of glycaemia with mortality and clinical outcomes. In this study, we evaluated if non-survivors are harder to control than survivors and determined if glycaemic outcome is a function of patient condition and eventual outcome or of the glycaemic control provided.
Clinically validated, model-based, hour-to-hour insulin sensitivity (SI) and its hour-to-hour variability (%ΔSI) were identified over the first 72 h of therapy in 145 patients (119 survivors, 26 non-survivors). In hypothesis testing, we compared distributions of SI and %ΔSI in 6-hourly blocks for survivors and non-survivors. In equivalence testing, we assessed if differences in these distributions, based on blood glucose measurement error, were clinically significant.
SI level was never equivalent between survivors and non-survivors (95% CI of percentage difference in medians outside ±12%). Non-survivors had higher SI, ranging from 9% to 47% higher overall in 6-h blocks, and this difference became statistically significant as glycaemic control progressed. %ΔSI was equivalent between survivors and non-survivors for all 6-hourly blocks (95% CI of difference in medians within ±12%) and decreased in general over time as glycaemic control progressed.
Whereas non-survivors had higher SI levels, variability was equivalent to that of survivors over the first 72 h. These results indicate survivors and non-survivors are equally controllable, given an effective glycaemic control protocol, suggesting that glycaemia level and variability, and thus the association between glycaemia and outcome, are essentially determined by the control provided rather than by underlying patient or metabolic condition.
Alzheimer's disease is characterized by the presence of amyloid-β and tau deposition in the brain, hippocampal atrophy and increased rates of hippocampal atrophy over time. Another protein, TAR DNA ...binding protein 43 (TDP-43) has been identified in up to 75% of cases of Alzheimer's disease. TDP-43, tau and amyloid-β have all been linked to hippocampal atrophy. TDP-43 and tau have also been linked to hippocampal atrophy in cases of primary age-related tauopathy, a pathological entity with features that strongly overlap with those of Alzheimer's disease. At present, it is unclear whether and how TDP-43 and tau are associated with early or late hippocampal atrophy in Alzheimer's disease and primary age-related tauopathy, whether either protein is also associated with faster rates of atrophy of other brain regions and whether there is evidence for protein-associated acceleration/deceleration of atrophy rates. We therefore aimed to model how these proteins, particularly TDP-43, influence non-linear trajectories of hippocampal and neocortical atrophy in Alzheimer's disease and primary age-related tauopathy. In this longitudinal retrospective study, 557 autopsied cases with Alzheimer's disease neuropathological changes with 1638 ante-mortem volumetric head MRI scans spanning 1.0-16.8 years of disease duration prior to death were analysed. TDP-43 and Braak neurofibrillary tangle pathological staging schemes were constructed, and hippocampal and neocortical (inferior temporal and middle frontal) brain volumes determined using longitudinal FreeSurfer. Bayesian bivariate-outcome hierarchical models were utilized to estimate associations between proteins and volume, early rate of atrophy and acceleration in atrophy rates across brain regions. High TDP-43 stage was associated with smaller cross-sectional brain volumes, faster rates of brain atrophy and acceleration of atrophy rates, more than a decade prior to death, with deceleration occurring closer to death. Stronger associations were observed with hippocampus compared to temporal and frontal neocortex. Conversely, low TDP-43 stage was associated with slower early rates but later acceleration. This later acceleration was associated with high Braak neurofibrillary tangle stage. Somewhat similar, but less striking, findings were observed between TDP-43 and neocortical rates. Braak stage appeared to have stronger associations with neocortex compared to TDP-43. The association between TDP-43 and brain atrophy occurred slightly later in time (∼3 years) in cases of primary age-related tauopathy compared to Alzheimer's disease. The results suggest that TDP-43 and tau have different contributions to acceleration and deceleration of brain atrophy rates over time in both Alzheimer's disease and primary age-related tauopathy.
We investigate whether there is any association between the Braak neurofibrillary tangle (NFT) stage and clinical and MRI features in definite primary age-related tauopathy (PART). We analysed 52 ...cases with a Braak NFT tangle stage >0 and ≤IV, and a Thal phase of 0 (no beta-amyloid present). Twenty-nine (56%) were female. Median age at death was 88 years (IQR 82–92 years). Fifteen (29%) were TDP-positive (75% TDP stage I), 16 (31%) had argyrophilic grain disease and three (6%) had alpha-synuclein-positive Lewy bodies. TDP-43 inclusion when present were rare and predominantly perivascular. Of the 15 with TDP-43, three showed a moderate number of inclusions and also had hippocampal sclerosis, neuronal intranuclear inclusions and fine neurites of the CA1 region of the hippocampus. Four cases (8%) had an apolipoprotein epsilon 4 (APOE4) allele. There was a significant correlation between age at death and Braak NFT stage (
r
= 0.32,
p
= 0.02). After accounting for age at clinical examination, there were significant associations between Braak NFT stage, and WAIS-R Block Design and Trail Making Tests A and B, with higher Braak stage associated with poorer performances. Thirty of the 52 cases had completed an antemortem volumetric head MRI. Two separate MRI analyses revealed an association between higher Braak NFT stage and grey matter atrophy in the head of the left hippocampus. There were no significant clinical or radiologic associations with TDP-43. Findings from this study demonstrate that aggregated tau distribution is associated with poorer cognitive performance, as well as atrophy, in the absence of beta-amyloid. These findings support the parcellation of definite PART as a useful construct. The relatively low frequencies of APOE4, TDP-43, Lewy bodies, and hippocampal sclerosis, and the rarity and morphology of TDP-43 lesions are noted contrasts to what is typically observed in Alzheimer’s disease of the old.
Optimising smoking cessation (SC) referral strategies within lung cancer screening (LCS) could significantly reduce lung cancer mortality. This study aimed to measure acceptance of referral to SC ...support by either practitioner-referral or self-referral among participants attending a hospital-based lung health check appointment for LCS as part of the Lung Screen Uptake Trial.
Single-blinded two-arm randomised controlled trial.
England.
Six hundred forty-two individuals ages 60 to 75 years, who self-reported currently smoking or had a carbon monoxide reading over 10 ppm during the lung health check appointment.
Participants were randomised (1:1) to receive either a contact information card for self-referral to a local stop smoking service (SSS) (self-referral, n = 360) or a SSS referral made on their behalf by the nurse or trial practitioner (practitioner-referral, n = 329).
The primary outcome was acceptance of the practitioner-referral (defined as participants giving permission for their details to be shared with the local SSS) compared with acceptance of the self-referral (defined as participants taking the physical SSS contact information card to refer themselves to the local SSS).
Half (49.8%) accepted the practitioner-made referral to a local SSS, whereas most (88.5%) accepted the self-referral. The odds of accepting the practitioner-referral were statistically significantly lower (adjusted odds ratio = 0.10; 95% confidence interval = 0.06-0.17) than the self- referral. In analyses stratified by group, greater quit confidence, quit attempts and Black ethnicity were associated with increased acceptance within the practitioner-referral group. There were no statistically significant interactions between acceptance by referral group and any of the participants' demographic or smoking characteristics.
Among participants in hospital-based lung cancer screening in England who self-reported smoking or met a carbon monoxide cut-off, both practitioner-referral and self-referral smoking cessation strategies were highly accepted. Although self-referral was more frequently accepted, prior evidence suggests practitioner-referrals increase quit attempts, suggesting practitioner-referrals should be the first-line strategy within lung cancer screening, with self-referral offered as an alternative.
Low uptake of low-dose computed tomography (LDCT) lung cancer screening, particularly by current smokers of a low socioeconomic position, compromises effectiveness and equity.
To compare the effect ...of a targeted, low-burden, and stepped invitation strategy versus control on uptake of hospital-based Lung Health Check appointments offering LDCT screening.
In a two-arm, blinded, between-subjects, randomized controlled trial, 2,012 participants were selected from 16 primary care practices using these criteria:
) aged 60 to 75 years,
) recorded as a current smoker within the last 7 years, and
) no prespecified exclusion criteria contraindicating LDCT screening. Both groups received a stepped sequence of preinvitation, invitation, and reminder letters from their primary care practitioner offering prescheduled appointments. The key manipulation was the accompanying leaflet. The intervention group's leaflet targeted psychological barriers and provided low-burden information, mimicking the concept of the U.K. Ministry of Transport's annual vehicle test ("M.O.T. For Your Lungs").
Uptake was 52.6%, with no difference between intervention (52.3%) and control (52.9%) groups in unadjusted (odds ratio OR, 0.98; 95% confidence interval CI, 0.82-1.16) or adjusted (OR, 0.98; 95% CI, 0.82-1.17) analyses. Current smokers were less likely to attend (adjusted OR, 0.70; 95% CI, 0.56-0.86) than former smokers. Socioeconomic deprivation was significantly associated with lower uptake for the control group only (
< 0.01).
The intervention did not improve uptake. Regardless of trial arm, uptake was considerably higher than previous clinical and real-world studies, particularly given that the samples were predominantly lower socioeconomic position smokers. Strategies common to both groups, including a Lung Health Check approach, could represent a minimum standard.Clinical trial registered with www.clinicaltrials.gov (NCT02558101) and registered prospectively with the International Standard Registered Clinical/Social Study (N21774741).
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